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Sample records for polychaete nereis virens

  1. ORGANIC CONTAMINANT DISTRIBUTION IN SEDIMENTS, POLYCHAETES (NEREIS VIRENS) AND THE AMERICAN LOBSTER, HOMARUS AMERICANUS IN A LABORATORY FOOD CHAIN EXPERIMENT

    EPA Science Inventory

    A laboratory experiment was conducted to investigate the transfer of organic contaminants from an environmentally contaminated marine sediment through a simple marine food chain. The infaunal polychaete, Nereis virens, was exposed to contaminated sediment collected from the Passa...

  2. Authentic FMRFamide is present in the polychaete Nereis virens.

    PubMed

    Krajniak, K G; Price, D A

    1990-01-01

    The tetrapeptide FMRFamide is but one member of a large family of invertebrate neuropeptides which includes another tetrapeptide, FLRFamide, and several longer peptides terminating in one or the other of these tetrapeptide sequences. These peptides have been isolated from both molluscs and arthropods, but so far not one has been isolated from an annelid. Since the annelid worms are believed to share a common ancestor with molluscs and arthropods, they should contain FMRFamide-like peptides. We found two immunoreactive peaks in Nereis virens, but microsequencing and fast atom bombardment mass spectrometry revealed that they represent only one native peptide, FMRFamide. (The other peak is its methionyl sulfoxide derivative.) Each worm contained only 100 to 600 fmols of peptide, which is at least 10-100 times less than the levels in molluscs. Our identification of a tetrapeptide, and only a tetrapeptide, in this worm suggests that the tetrapeptides are the more ancient members of the family, and were probably present in the common ancestors of the annelids, arthropods, and molluscs.

  3. Hox gene expression in larval development of the polychaetes Nereis virens and Platynereis dumerilii (Annelida, Lophotrochozoa).

    PubMed

    Kulakova, Milana; Bakalenko, Nadezhda; Novikova, Elena; Cook, Charles E; Eliseeva, Elena; Steinmetz, Patrick R H; Kostyuchenko, Roman P; Dondua, Archil; Arendt, Detlev; Akam, Michael; Andreeva, Tatiana

    2007-01-01

    The bilaterian animals are divided into three great branches: the Deuterostomia, Ecdysozoa, and Lophotrochozoa. The evolution of developmental mechanisms is less studied in the Lophotrochozoa than in the other two clades. We have studied the expression of Hox genes during larval development of two lophotrochozoans, the polychaete annelids Nereis virens and Platynereis dumerilii. As reported previously, the Hox cluster of N. virens consists of at least 11 genes (de Rosa R, Grenier JK, Andreeva T, Cook CE, Adoutte A, Akam M, Carroll SB, Balavoine G, Nature, 399:772-776, 1999; Andreeva TF, Cook C, Korchagina NM, Akam M, Dondua AK, Ontogenez 32:225-233, 2001); we have also cloned nine Hox genes of P. dumerilii. Hox genes are mainly expressed in the descendants of the 2d blastomere, which form the integument of segments, ventral neural ganglia, pre-pygidial growth zone, and the pygidial lobe. Patterns of expression are similar for orthologous genes of both nereids. In Nereis, Hox2, and Hox3 are activated before the blastopore closure, while Hox1 and Hox4 are activated just after this. Hox5 and Post2 are first active during the metatrochophore stage, and Hox7, Lox4, and Lox2 at the late nectochaete stage only. During larval stages, Hox genes are expressed in staggered domains in the developing segments and pygidial lobe. The pattern of expression of Hox cluster genes suggests their involvement in the vectorial regionalization of the larval body along the antero-posterior axis. Hox gene expression in nereids conforms to the canonical patterns postulated for the two other evolutionary branches of the Bilateria, the Ecdysozoa and the Deuterostomia, thus supporting the evolutionary conservatism of the function of Hox genes in development.

  4. Trophic transfer of trace metals from the polychaete worm Nereis diversicolor to the polychaete N. virens and the decapod crustacean Palaemonetes varians

    USGS Publications Warehouse

    Rainbow, P.S.; Poirier, L.; Smith, B.D.; Brix, K.V.; Luoma, S.N.

    2006-01-01

    Diet is an important exposure route for the uptake of trace metals by aquatic invertebrates, with trace metal trophic transfer depending on 2 stages - assimilation and subsequent accumulation by the predator. This study investigated the trophic transfer of trace metals from the sediment-dwelling polychaete worm Nereis diversicolor from metal-rich estuarine sediments in southwestern UK to 2 predators - another polychaete N. virens (Cu, Zn, Pb, Cd, Fe) and the decapod crustacean Palaemonetes varians (Cu, Zn, Pb, Cd, Fe, Ag, As, Mn). N. virens showed net accumulation of Cu, Zn, Pb and Cd from the prey; accumulation increased with increasing prey concentration, but a coefficient of trophic transfer decreased with increasing prey concentration, probably because a higher proportion of accumulated metal in the prey is bound in less trophically available (insoluble) detoxified forms. The trace metal accumulation patterns of P. varians apparently restricted significant net accumulation of metals from the diet of N. diversicolor to just Cd. There was significant mortality of the decapods fed on the diets of metal-rich worms. Metal-rich invertebrates that have accumulated metals from the rich historical store in the sediments of particular SW England estuaries can potentially pass these metals along food chains, with accumulation and total food chain transfer depending on the metal assimilation efficiencies and accumulation patterns of the animal at each trophic level. This trophic transfer may be significant enough to have ecotoxicological effects. ?? Inter-Research 2006.

  5. Influence of bioturbation by the amphipod Corophium volutator on fluoranthene uptake in the marine polychaete Nereis virens

    SciTech Connect

    Ciarelli, S.; Kater, B.J.; Straalen, N.M. van

    2000-06-01

    The uptake kinetics of fluoranthene in the polychaete worm Nereis virens were investigated in the presence and in the absence of amphipods to examine the effects of sediment bioturbation by the benthic amphipod Corophium volutator on the uptake in worms. Worms only and worms together with two different densities of amphipods were exposed to fluoranthene-spiked sediment for 12 d. Worms and overlying water samples for fluoranthene analyses were taken and total suspended solids in water column were measured after 1, 2, 5, 8, and 12 d. Results showed that in all treatments fluoranthene was rapidly accumulated by N. virens during the first two days and a steady state was reached within five days of exposure. Biota to sediment accumulation factors normalized to lipid concentration and to sediment organic carbon (BAF{sub ioc}) or worms exposed with the highest number of amphipods were significantly higher (two to three times) compared to worms exposed with fewer or without amphipods after one and two days of exposure. Bioconcentration factors (BCFs), calculated as the ratio between the uptake (k{sub 1}) and elimination (k{sub 2}) rate constants were not significantly different among treatments. When BCFs were calculated on the basis of dissolved fluoranthene concentrations (BCF{sub diss}), values of the treatments where worms were exposed with 100 and 300 amphipods were slightly higher than those calculated on the basis of total (dissolved + particle-bound) aqueous fluoranthene (BCF{sub tot}). However, the presence of fluoranthene bound to dissolved organic matter could have accounted for lower than expected BCF{sub diss} values. The results suggest that bioturbation by amphiopoc, affected the concentration of fluoranthene in the worms not by changing the worm to water partitioning (k{sub 1}/k{sub 2}) but by changing the worm to sediment partitioning (BAF{sub ioc}). In the treatments with worms a higher mortality of amphipods was found compared to those without worms. The

  6. ParaHox gene expression in larval and postlarval development of the polychaete Nereis virens (Annelida, Lophotrochozoa)

    PubMed Central

    Kulakova, Milana A; Cook, Charles E; Andreeva, Tatiana F

    2008-01-01

    Background Transcription factors that encode ANTP-class homeobox genes play crucial roles in determining the body plan organization and specification of different organs and tissues in bilaterian animals. The three-gene ParaHox family descends from an ancestral gene cluster that existed before the evolution of the Bilateria. All three ParaHox genes are reported from deuterostomes and lophotrochozoans, but not to date from any ecdysozoan taxa, and there is evidence that the ParaHox genes, like the related Hox genes, were ancestrally a single chromosomal cluster. However, unlike the Hox genes, there is as yet no strong evidence that the ParaHox genes are expressed in spatial and temporal order during embryogenesis. Results We isolated fragments of the three Nereis virens ParaHox genes, then used these as probes for whole-mount in situ hybridization in larval and postlarval worms. In Nereis virens the ParaHox genes participate in antero-posterior patterning of ectodermal and endodermal regions of the digestive tract and are expressed in some cells in the segment ganglia. The expression of these genes occurs in larval development in accordance with the position of these cells along the main body axis and in postlarval development in accordance with the position of cells in ganglia along the antero-posterior axis of each segment. In none of these tissues does expression of the three ParaHox genes follow the rule of temporal collinearity. Conclusion In Nereis virens the ParaHox genes are expressed during antero-posterior patterning of the digestive system (ectodermal foregut and hindgut, and endodermal midgut) of Nereis virens. These genes are also expressed during axial specification of ventral neuroectodermal cell domains, where the expression domains of each gene are re-iterated in each neuromere except for the first parapodial segment. These expression domains are probably predetermined and may be directed on the antero-posterior axis by the Hox genes, whose

  7. Vasa, PL10, and Piwi gene expression during caudal regeneration of the polychaete annelid Alitta virens.

    PubMed

    Kozin, Vitaly V; Kostyuchenko, Roman P

    2015-06-01

    Polychaetes are famous for their outstanding ability to regenerate lost body parts. Moreover, these worms possess a number of ancestral features in anatomy, development, and genetics, making them particularly suitable for comparative studies. Thus, fundamental as well as new undisclosed so far features of regenerative processes may be revealed, using polychaetes as a model. In the present work, we aimed to analyze the molecular basis of caudal regeneration in the nereid polychaete Alitta virens (formerly Nereis virens). We focused on homologues genes of RNA helicases Vasa and PL10 and ncRNA-binding proteins Piwi. These markers are suggested to play a significant role in maintenance of undifferentiated state of primordial germ cells and multipotent stem cells across invertebrates. In normal conditions, A. virens homologues of Vasa, PL10, and Piwi were differentially expressed in the subterminal growth zone and germline cells. Caudal amputation induced expression of studied genes de novo, which further accompanies all steps of regeneration. An early appearance of the transcripts in wound epithelium and internal blastemal cells suggests involvement of these genes in the well-known cell dedifferentiation events that assure polychaete regeneration. Provided interpretation of the gene expression dynamics implies the primary restoration of the pygidium and growth zone, which promotes following segment formation. Obtained results are valuable as a molecular fingerprint of the alterations occurring in regulatory state of locally regenerating tissues. PMID:25772273

  8. Hox gene expression during postlarval development of the polychaete Alitta virens

    PubMed Central

    2013-01-01

    Background Hox genes are the family of transcription factors that play a key role in the patterning of the anterior-posterior axis of all bilaterian animals. These genes display clustered organization and colinear expression. Expression boundaries of individual Hox genes usually correspond with morphological boundaries of the body. Previously, we studied Hox gene expression during larval development of the polychaete Alitta virens (formerly Nereis virens) and discovered that Hox genes are expressed in nereid larva according to the spatial colinearity principle. Adult Alitta virens consist of multiple morphologically similar segments, which are formed sequentially in the growth zone. Since the worm grows for most of its life, postlarval segments constantly change their position along the anterior-posterior axis. Results We studied the expression dynamics of the Hox cluster during postlarval development of the nereid Alitta virens and found that 8 out of 11 Hox genes are transcribed as wide gene-specific gradients in the ventral nerve cord, ectoderm, and mesoderm. The expression domains constantly shift in accordance with the changing proportions of the growing worm, so expression domains of most Hox genes do not have stable anterior or/and posterior boundaries. In the course of our study, we revealed long antisense RNA (asRNA) for some Hox genes. Expression patterns of two of these genes were analyzed using whole-mount in-situ hybridization. This is the first discovery of antisense RNA for Hox genes in Lophotrochozoa. Conclusion Hox gene expression in juvenile A. virens differs significantly from Hox gene expression patterns both in A. virens larva and in other Bilateria. We suppose that the postlarval function of the Hox genes in this polychaete is to establish and maintain positional coordinates in a constantly growing body, as opposed to creating morphological difference between segments. PMID:23635090

  9. Epitoky in Nereis (Neanthes) virens (Polychaeta: Nereididae): a story about sex and death.

    PubMed

    Hébert Chatelain, Etienne; Breton, Sophie; Lemieux, Hélène; Blier, Pierre U

    2008-01-01

    The nereidid Nereis (Neanthes) virens undergoes drastic behavioural, morphological and physiological changes during its sexual maturation (epitoky). This metamorphosis prepares benthic worms for a brief pelagic existence devoted to mating although in N. virens only mature males leave their burrows to swarm. After spawning, individuals of both sexes die. Specific adjustments of energy metabolism pathway allowing higher muscular activity and swimming capacity remain to be eluded. This study compared atokous worms (immature) and epitokous (mature) swimming males and benthic females of N. virens to detect metabolic changes that could occur during epitoky. Epitokous males showed significantly higher electron transport system, citrate synthase and aspartate aminotransferase activities (p<0.01) and significantly lower lactate dehydrogenase activity (p<0.01) compared to atokous worms and epitokous females. There was no difference in antioxidant enzyme capacities between epitokes and atokes. Lipase and trypsin activities were significantly lower (p<0.01) in epitokous males. The enzymatic changes observed are likely related to the metabolic adjustments required to support higher swimming abilities. Maintenance of antioxidant capacities could be related to protection of germinal tissues more than long term survival, since N. virens die after spawning. PMID:17942355

  10. The localization of FMRFamide in the nervous and somatic tissues of Nereis virens and its effects upon the isolated esophagus.

    PubMed

    Krajniak, K G; Greenberg, M J

    1992-01-01

    1. The tetrapeptide FMRFamide which is present in extracts of Nereis virens was localized in various nereid tissues immunohistochemically. 2. Immunoreactive FMRFamidergic cells and fibers were found in the supraesophageal (brain) and subesophageal ganglia, as well as in the intersegmental ganglia of the ventral nerve cord. Immunoreactive fibers were present in the neuropile of, and the connectives between, the supraesophageal, subesophageal, and intersegmental ganglia. 3. In the periphery immunoreactive FMRFamidergic fibers and a few cell bodies were observed in the gut. Sparse fibers were also seen in the body wall, parapodia, and cephalic palps. When the antiserum was preabsorbed with FMRFamide, no specific immunoreactivity was detected. 4. The esophagus of Nereis, isolated and suspended in a tissue bath, responded to FMRFamide with a dose-dependent relaxation; threshold was between 30 and 300 nM, and the EC50 was 1.55 +/- 0.60 microM. Benzoquinonium did not modify this response. 5. Thus, FMRFamide seems to be a neurotransmitter in both the central and peripheral nervous system of Nereis virens, and may be involved in the control of esophageal motility.

  11. The effects of the polychaete Nereis diversicolor on the distribution and transplanting success of Zostera noltii

    NASA Astrophysics Data System (ADS)

    Hughes, R. G.; Lloyd, D.; Ball, L.; Emson, D.

    2000-07-01

    Loss of saltmarsh vegetation in south-east England is a significant problem for conservation and coastal defence. The losses of vegetation began in the 1930s with the loss of intertidal Zostera marina and have continued more recently. Some preliminary trials at re-establishing Zostera in some estuaries of Essex have not been successful. This paper addresses the hypothesis that the infauna, particularly the polychaete Nereis diversicolor, may restrict natural colonisation by Zostera and reduce the success of transplanting trials. In field experiments, Z. noltii were transplanted into areas where Nereis were common, close to an established seagrass bed and into two other estuaries. The transplants protected from the effects of the polychaetes by netting had a higher survival rate, lower index of root damage and greater biomass at the end of the experiments than those that were unprotected. In laboratory experiments, Nereis reduced the survival of Z. noltii. They were observed grasping the leaves and pulling them into their burrows. These results indicate that herbivory and disturbance by N. diversicolor is responsible, at least in part, for the restriction of the distribution of Z. noltii and may have been important in limiting the success of previous transplanting experiments. A hypothesis is proposed which states that there are two stable states on the upper mud-flats. One state is dominated by plants, including Zostera spp., which prevent colonisation by burrowing infauna, and the other is dominated by infauna which prevent colonisation by plants. Managing these two states could be the key to re-establishing the early successional stages of saltmarsh development.

  12. Toxicity and bioaccumulation of sediment-associated silver nanoparticles in the estuarine polychaete, Nereis (Hediste) diversicolor.

    PubMed

    Cong, Yi; Banta, Gary T; Selck, Henriette; Berhanu, Deborah; Valsami-Jones, Eugenia; Forbes, Valery E

    2014-11-01

    In this study, the toxicities of sediment-associated silver added to sediment as commercially available silver nanoparticles (Ag NPs, 20 and 80 nm) and aqueous Ag (AgNO3) to the estuarine polychaete, Nereis (Hediste) diversicolor, were investigated for both individual and subcellular endpoints after 10 d of exposure. Both Ag NP types were characterized in parallel to the toxicity studies and found to be polydispersed and overlapping in size. Burrowing activity decreased (marginally) with increasing Ag concentration and depended on the form of Ag added to sediment. All worms accumulated Ag regardless of the form in which it was added to the sediment, and worm size (expressed as dry weight) was found to significantly affect bioaccumulation such that smaller worms accumulated more Ag per body weight than larger worms. Lysosomal membrane permeability (neutral red retention time, NRRT) and DNA damage (comet assay tail moment and tail DNA intensity %) of Nereis coelomocytes increased in a concentration-dependent manner in all three Ag treatments. Ag NP treatments were more toxic than aqueous Ag for all toxicity endpoints, even though bioaccumulation did not differ significantly among Ag forms. No significant difference in toxicity was observed between the two Ag NP treatments which was attributed to their overlap in particle size.

  13. Chronic toxicity of phenanthrene to the marine polychaete worm, Nereis (Neanthes) arenaceodentata

    SciTech Connect

    Emery, V.L. Jr.; Dillon, T.M.

    1996-02-01

    Polycyclic aromatic hydrocarbons (PAHs) are widely distributed in the environment. While environmental concentrations are generally below acutely, lethal levels, chronic, low level exposures may result in subtle sublethal effects. PAHs accumulate in bottom sediments and may represent a hazard to the benthos. Polychaetes are important members of this community. The objective of this study is to evaluate the chronic sublethal effects of one PAH, phenanthrene (PHN), on the polychaete worm, Nereis arenaceodentata. PHN was selected because of its high toxicity to marine invertebrates relative to other PAHs. The response of bivalves to heavy metals and other toxins has usually been determined by observing valve position. Since mussels close their valves to avoid noxious stimuli, experimental delivery of chemicals is uncertain. To obtain constant results. Preston employed plastic spacers to hold the valves apart. This obviates the observation of valve position as an index of response, and some other method is required. Electromyography of intact mussels is one such index, and is shown to be a simple, effective and quantitative measurement of activity. Experiments are reported on the effects of added mercury on salt water and fresh water species. Parts of this Nvork have appeared in brief form.

  14. Joint toxicity of sediment-associated DDT and copper to a polychaete, Nereis succinea.

    PubMed

    Wang, Fei; Qi, Hong-Xue; You, Jing

    2015-03-01

    As major components in antifouling paints, both dichlorodiphenyltrichloroethane (DDT) and copper are ubiquitous in estuarine sediment and have been detected at high concentrations in the harbors in South China. In the present study joint toxicity between DDT and copper to an estuarine polychaete, Nereis succinea, was examined using bioaccumulation potential, growth impairment and change in lipid peroxidation contents as sub-lethal endpoints. In general, the toxicity of DDXs (DDT and its metabolites) and copper acted independently and copper was more toxic to the lugworms at environmentally relevant concentrations. Nevertheless, co-exposure to copper led to a significant reduction in the bioaccumulation of DDXs when the concentrations of DDXs in sediment were high. The inhibition of DDX bioaccumulation by copper may be partially explained by the decrease in the bioavailability of sediment-associated DDXs which were estimated by biomimetic gut fluid extraction. The saturation of the solubilization agents or the inhibition of protease activity in gut fluid of N. succinea by copper limited the DDX bioavailability and the subsequent bioaccumulation.

  15. Nereis alacranensis, a new species of polychaete (Annelida, Nereididae) from Alacranes Reef, southern Gulf of Mexico, with a key to Nereis from the Grand Caribbean.

    PubMed

    Ramírez Hernández, Adriana; Hernández-Alcántara, Pablo; Solís-Weiss, Vivianne

    2015-09-02

    A new species of polychaete, Nereis alacranensis n. sp., was found in dead coral rocks in the intertidal zone of Alacranes reef, southern Gulf of Mexico. N. alacranensis n. sp. can be included in a group of nereidids characterized by the absence of paragnaths in areas I and V of the pharynx, the presence of cones in a single row or absent in areas VII-VIII, and short blades in notopodial homogomph falcigers. The new species can be separated from the other species of the group by the presence of 3-7 cones in area VI and 7 cones arranged in a row in areas VII-VIII, finely dentate blades in notopodial homogomph falcigers, but most of all, by the presence of an unusual brown coarse arc shaped plate on the external ventral region of the peristomium. This structure has not yet been reported, at least in this genus. A taxonomic key of the species of Nereis recorded from the Grand Caribbean region is included.

  16. Development of a chronic sublethal bioassay for evaluating contaminated sediment with the marine polychaete worm Nereis (Neanthes) arenaceodentata

    SciTech Connect

    Dillon, T.M.; Moore, D.W.; Gibson, A.B. )

    1993-03-01

    Development of a chronic sublethal sediment bioassay with the polychaete Nereis (Neanthes) arenaceodentata is described. The sublethal test end point was estimated individual somatic growth rate. The test was initiated with two-to three-week-old post-emergent juvenile worms and continued for 28 d. The potential bias due to selected nontreatment factors on polychaete survival and growth was evaluated. For example, grain size has no significant effect, whereas the number of worms placed in each exposure vessel was critical. Direct transfer from 30[per thousand] seawater to salinites [<=] 15[per thousand] had a highly significant and adverse effect on survival and growth. Both survival and growth of juvenile worms may be adversely affected if test conditions involve exposures to [>=] 0.7 mg/L un-ionized ammonia or [>=] 5 mg/L hydrogen sulfide. Survival of juvenile worms to concentrations of the reference toxicant, cadmium chloride, approximating the 96-h LC50 (5 mg/L) was used as a quality control measure. Results are expressed in control chart format analogous to methods used in analytical chemistry.

  17. Comparison of marine sediment toxicity test protocols for the amphipod Rhepoxynius abronius and the polychaete worm Nereis (Neanthes) arenaceodentata

    SciTech Connect

    Anderson, B.S.; Hunt, J.W.; Phillips, B.M. |

    1998-05-01

    The 10-d amphipod survival toxicity test protocol using Rhepoxynius abronius was compared to the 20-d polychaete worm growth and survival protocol using Nereis (Neanthes) arenaceodentata. Of the 341 sediment samples collected in California and tested over a 2-year period. 78% significantly inhibited R. abronius survival, whereas 2 and 26% significantly inhibited N. arenaceodentata survival and biomass, respectively. Statistical power associated with each protocol endpoint was determined by calculating the minimum significant difference (MSD) for each test protocol for this data set. The 90th percentile MSDs for R. abronius survival and N. arenaceodentata survival and biomass were 16, 36, and 56%, respectively. Survival of R. abronius was significantly negatively correlated with a number of toxicants including metals, pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls. No significant correlations were determined between N. arenaceodentata survival or biomass and contaminants measured. Amphipod survival was also negatively correlated with sediment total organic carbon and grain size, but when samples with a high percent fine grain size (>90% fines) were eliminated from consideration, the overall conclusions of the study were not altered. The 10-d amphipod survival protocol using R. abronius was a more sensitive indicator of toxicity, but the results indicate that this was due to greater statistical power rather than greater sensitivity of the test organisms or endpoints.

  18. Smelling Danger – Alarm Cue Responses in the Polychaete Nereis (Hediste) diversicolor (Müller, 1776) to Potential Fish Predation

    PubMed Central

    Schaum, C. Elisa; Batty, Robert; Last, Kim S.

    2013-01-01

    The harbour ragworm, Nereis (Hediste) diversicolor is a common intertidal marine polychaete that lives in burrows from which it has to partially emerge in order to forage. In doing so, it is exposed to a variety of predators. One way in which predation risk can be minimised is through chemical detection from within the relative safety of the burrows. Using CCTV and motion capture software, we show that H. diversicolor is able to detect chemical cues associated with the presence of juvenile flounder (Platichthys flesus). Number of emergences, emergence duration and distance from burrow entrance are all significantly reduced during exposure to flounder conditioned seawater and flounder mucous spiked seawater above a threshold with no evidence of behavioural habituation. Mucous from bottom-dwelling juvenile plaice (Pleuronectes platessa) and pelagic adult herring (Clupea harengus) elicit similar responses, suggesting that the behavioural reactions are species independent. The data implies that H. diversicolor must have well developed chemosensory mechanisms for predator detection and is consequently able to effectively minimize risk. PMID:24155953

  19. Lipoprotein mediated lipid uptake in oocytes of polychaetes (Annelida).

    PubMed

    Schenk, Sven; Hoeger, Ulrich

    2009-08-01

    The uptake of the 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI)-labeled sex-unspecific Nereis lipoprotein was investigated in oocytes of the nereidid polychaetes Nereis virens and Platynereis dumerilii. The fluorescence label was first observed in endocytic vesicles (<1 microm diameter), which later fused to larger vesicles (2-3 microm); these were finally incorporated into existing unlabeled yolk granules (5-6 microm). In Platynereis oocytes, the fusion of endocytic vesicles was delayed in oocytes at their final stage of development compared with those at an early stage of development. Lipoprotein double-labeled with fluorescein isothiocyanate (FITC) and DiI revealed that both the protein and the lipid moiety remained co-localized during incorporation into the yolk granules of the oocyte. No labeling of the cytoplasmic lipid droplets was observed. In N. virens, unlabeled Nereis lipoprotein was effective as a competitive inhibitor of DiI-labeled Nereis lipoprotein. Ligand blot experiments demonstrated the presence of a lipoprotein receptor with an apparent molecular mass of 120 kDa, which is different from that of the known yolk protein receptor. This indicates the presence, in the polychaete oocyte, of two distinct receptors mediating yolk protein and lipoprotein uptake, respectively. Thus, the sex-unspecific lipoprotein contributes to the lipid supply of the growing oocyte in addition to the known uptake of the yolk-protein-associated lipids. The absence of label in the cytoplasmic lipid droplets, even after prolonged incubation with labeled lipoprotein, suggests that these lipids arise either by the breakdown and resynthesis of lipoprotein-derived lipids and/or by de novo synthesis within the oocyte.

  20. Tolerance to metals and assessment of energy reserves in the polychaete Nereis diversicolor in clean and contaminated estuaries.

    PubMed

    Durou, C; Mouneyrac, C; Amiard-Triquet, C

    2005-02-01

    Estuaries are subject to anthropogenic activities. Because the intrasedimentary worm Nereis diversicolor has ecological characteristics and bioindicator abilities, its use was pertinent in investigating the concepts and cost of tolerance to heavy metals (Cd, Cu, Zn). In this context, two approaches were carried out, performing toxicity tests and estimating energy reserves (glycogen and lipids), in populations originating from a contaminated site (Seine estuary) compared with those from a clean site (Authie estuary). Mean lethal times (LT(50)s) of organisms exposed to zinc from the Seine estuary were higher than those from the Authie estuary, but not of organisms exposed to Cd or Cu. The influence of animal weight and salinity on the sensitivity of worms also was studied. The biggest worms were more tolerant to zinc than the smallest ones, and worms survived longer at a reduced salinity (15 per thousand). Concentrations of glycogen and lipids in each sampling season were higher in specimens from the Authie estuary than in worms from the Seine estuary. No influence of salinity on glycogen and lipid levels was observed. Glycogen concentrations were not influenced by the weight of specimens, whereas lipid concentrations were significantly and positively correlated with weight. In conclusion, worms from the Seine estuary exhibited tolerance to Zn, and the depletion of energy reserves observed in this population could be interpreted as a cost of tolerance.

  1. Effects of organophosphate and carbamate pesticides on acetylcholinesterase and choline acetyltransferase activities of the polychaete Nereis diversicolor.

    PubMed

    Scaps, P; Demuynck, S; Descamps, M; Dhainaut, A

    1997-08-01

    A toxicity test for organophosphates (OP) and carbamates (C) was improved with the adult ragworm Nereis diversicolor. Animals were maintained in U-shaped glass tubes of 4-mm inner diameter fixed vertically on a plastic plate and placed in glass aquaria. Each tank was covered with glass in order to reduce evaporation and heat dissipation. Temperature varied between 15 and 16 degrees C and salinity was constant (34 per thousand) during the entire length of the experiment. Experiments were performed with a fixed day length of 12 h and seawater was gently aerated. The maintenance system allowed the administration of OP and C compounds via the seawater. An acclimatization period of 48 h was not sufficient to accomodate worms to their artificial burrows; accordingly, we chose to acclimate worms for a week before beginning the exposure. Choline acetyltransferase (ChAT) activity was very low and was not significantly modified by two OP compounds: malathion and parathion-ethyl. ChAT is not a target for these pesticides and should not be used for future studies about OP and C toxicity. On the other hand, inhibitory effects on acetylcholinesterase (AChE) activity were determined at concentrations of 10(-6) M for three OP compounds-malathion, parathion-ethyl, and phosalone-and a carbamate pesticide-carbaryl. We measured only short-term effects and no cumulative effect was determined, the maximum percentage of AChE activity inhibition being between 2 (carbaryl) and 7 (OP compounds) days after exposure and then remaining stable. Mortality occured only after a period of intoxication of 14 days. N diversicolor, which can be easily maintained at the laboratory, seems to be a good candidate for future laboratory studies to test the toxicity of other pollutants.

  2. Research on polychaete annelid osmoregulatory peptide(s) by immunocytochemical and physiological approaches. Computer reconstruction of the brain and evidence for a role of angiotensin-like molecules in Nereis (Hediste) diversicolor OF Müller.

    PubMed

    Fewou, J; Dhainaut-Courtois, N

    1995-01-01

    Immunohistochemical and physiological studies were carried out on Nereis (Hediste) diversicolor OF Müller in order to obtain evidence concerning the neuroendocrine control of polychaete osmoregulation. The occurrence in this animal of peptides immunologically related to mammalian angiotensin II and I (AII and AI) and oxytocin (OT) was demonstrated in the brain and the ventral nerve cord (VNC) perikarya and nerve fibres as well as in a few peripheral structures (peripheral nerves, epithelial cells, nuchal organ, intestine and nephridia). The exact localization of immunoreactive cells was achieved by serial sections of brain and ventral nerve cord followed by a three-dimensional reconstruction of brain ganglionic nuclei using the CATIA ('Conception Assistée Tridimensionnelle Inter Active') Dassault system program. Injections of polyclonal antisera against AII or OT provoked a partial inhibition of the increase in body weight in Nereis exposed to hypo-osmotic medium. The effect of a-AII seemed more pronounced than that of a-OT. In a subsequent test, injections of synthetic AII and AII-amide (peptide recently isolated from an achaete (Salzet et al (1995) J Biol Chem 270, 1575-1582) enhanced the increase in body weight and, therefore, strengthened the hypothesis of the neuroendocrine control of Nereis osmoregulation. The antidiuretic effect of both synthetic peptides in this study was indicative of the exact role of Nereis endogenous molecule(s). AII was less potent than its amidated form. If AI-like can easily be struck off the list of putative endogenous osmoregulatory factors, the role of OT-like substance in Nereis osmoregulation, which is partially demonstrated in this study, needs to be clarified by further physiological experiments using injection of synthetic peptide(s) or endogenous substance(s). All these results are discussed and compared to those recently obtained in an achaete annelid (Salzet et al (1993) Brain Res 631, 247-255; Salzet et al (1993) Brain

  3. Biochemical and mechanical characterization of Nereis worm jaws

    NASA Astrophysics Data System (ADS)

    Broomell, Christopher C.

    The ultimate goal of biomimetics is to elucidate the design principles governing performance in biological materials and apply them to engineering systems. Successful transfer of these principles will require a thorough understanding of the complex interplay between molecular composition, organization and mechanical properties of the material. This dissertation describes the mechanical and biochemical characterization of jaws from the marine polychaete Nereis virens. Nereid jaws possess remarkable mechanical properties considering their predominantly organic composition. Hardness and stiffness are comparable to human dentin. However, in stark contrast to dentin, in Nereis these properties are achieved without mineralization. The role of metal ions in jaw sclerotization is addressed. In the pristine state, Zn ions are concentrated at the tip and toothed-edge of the jaw and are critical for hardness and modulus; both properties are reduced by ˜70% following Zn removal by treatment with EDTA. Furthermore, metal content in the jaw can be manipulated by soaking Zn-depleted samples in metal solutions; the comparative effects of treatment with alternative transition metals under both dry and hydrated conditions are described. The molecular composition of the jaw is also addressed. Protein comprises ˜90% of the jaw mass; amino acid analysis indicates that histidine is increased in the hardened, Zn-rich tip. The major protein component in Nereid jaw extracts is purified and characterized by partial peptide mapping and isolation of a partial clone from a jaw pulp cDNA library. Nvjp-1 is a 38 kDa glycine- histidine-rich protein and is believed to be the principle structural protein in the hardened jaw tip. The effects of selected environmental factors on Nvjp-1 structure and assembly are described. Transition from low to high pH is accompanied by changes in secondary structure and a significant molecular elongation. Furthermore, exposure to transition metals, notably Zn and

  4. Mesoderm patterning and morphogenesis in the polychaete Alitta virens (Spiralia, Annelida): Expression of mesodermal markers Twist, Mox, Evx and functional role for MAP kinase signaling.

    PubMed

    Kozin, Vitaly V; Filimonova, Daria A; Kupriashova, Ekaterina E; Kostyuchenko, Roman P

    2016-05-01

    Mesoderm represents the evolutionary youngest germ layer and forms numerous novel tissues in bilaterian animals. Despite the established conservation of the gene regulatory networks that drive mesoderm differentiation (e.g. myogenesis), mechanisms of mesoderm specification are highly variable in distant model species. Thus, broader phylogenetic sampling is required to reveal common features of mesoderm formation across bilaterians. Here we focus on a representative of Spiralia, the marine annelid Alitta virens, whose mesoderm development is still poorly investigated on the molecular level. We characterize three novel early mesodermal markers for A. virens - Twist, Mox, and Evx - which are differentially expressed within the mesodermal lineages. The Twist mRNA is ubiquitously distributed in the fertilized egg and exhibits specific expression in endomesodermal- and ectomesodermal-founder cells at gastrulation. Twist is expressed around the blastopore and later in a segmental metameric pattern. We consider this expression to be ancestral, and in support of the enterocoelic hypothesis of mesoderm evolution. We also revealed an early pattern of the MAPK activation in A. virens that is different from the previously reported pattern in spiralians. Inhibition of the MAPK pathway by U0126 disrupts the metameric Twist and Mox expression, indicating an early requirement of the MAPK cascade for proper morphogenesis of endomesodermal tissues. PMID:27000638

  5. Influence of copper oxide nanoparticle shape on bioaccumulation, cellular internalization and effects in the estuarine sediment-dwelling polychaete, Nereis diversicolor.

    PubMed

    Thit, Amalie; Dybowska, Agnieszka; Købler, Carsten; Kennaway, Gabrielle; Selck, Henriette

    2015-10-01

    CuO nanoparticles (NPs) released into the aquatic environment will likely accumulate in the sediment. Here we synthesized and characterized CuO NPs with different shapes and thus sizes: spheres, rods and spindles. Nereis diversicolor were exposed for 10 days to control sediment or sediment spiked with CuO NPs or aqueous Cu (Cu-Aq, CuCl2) at 7, 70 and 140 μg Cu g(-1) dw sediment. Cu from all Cu treatments accumulated in worms in a concentration-dependent manner. Only Cu-Aq decreased burrowing, suggesting that worms avoid Cu when added to sediment as Cu-Aq, but not CuO NPs. Transmission Electron Microscopy of gut sections indicated limited presence of CuO NP-like objects in the gut lumen, but evidence on whether accumulated Cu from CuO NP exposure was internalized as particles was not conclusive. Overall, bioavailability and avoidance was not influenced by particle shape or size, whereas Cu form (Cu-Aq vs particulate) and exposure concentration had significant impact. PMID:26149327

  6. Influence of copper oxide nanoparticle shape on bioaccumulation, cellular internalization and effects in the estuarine sediment-dwelling polychaete, Nereis diversicolor.

    PubMed

    Thit, Amalie; Dybowska, Agnieszka; Købler, Carsten; Kennaway, Gabrielle; Selck, Henriette

    2015-10-01

    CuO nanoparticles (NPs) released into the aquatic environment will likely accumulate in the sediment. Here we synthesized and characterized CuO NPs with different shapes and thus sizes: spheres, rods and spindles. Nereis diversicolor were exposed for 10 days to control sediment or sediment spiked with CuO NPs or aqueous Cu (Cu-Aq, CuCl2) at 7, 70 and 140 μg Cu g(-1) dw sediment. Cu from all Cu treatments accumulated in worms in a concentration-dependent manner. Only Cu-Aq decreased burrowing, suggesting that worms avoid Cu when added to sediment as Cu-Aq, but not CuO NPs. Transmission Electron Microscopy of gut sections indicated limited presence of CuO NP-like objects in the gut lumen, but evidence on whether accumulated Cu from CuO NP exposure was internalized as particles was not conclusive. Overall, bioavailability and avoidance was not influenced by particle shape or size, whereas Cu form (Cu-Aq vs particulate) and exposure concentration had significant impact.

  7. Redescriptions of Nereis oligohalina (Rioja, 1946) and N. garwoodi González-Escalante & Salazar-Vallejo, 2003 and description of N. confusa sp. n. (Annelida, Nereididae)

    PubMed Central

    Conde-Vela, Víctor M.; Salazar-Vallejo, Sergio I.

    2015-01-01

    Abstract Type material of several polychaete species described by Enrique Rioja from Mexican coasts are lost, and the current status of some species is doubtful. Nereis oligohalina (Rioja, 1946) was described from the Gulf of Mexico, but it has been considered a junior synonym of Nereis occidentalis Hartman, 1945, or regarded as a distinct species with an amphiamerican distribution. On the other hand, Nereis garwoodi González-Escalante & Salazar-Vallejo, 2003, described from Chetumal Bay, Caribbean coasts, could be confused with Nereis oligohalina. In order to clarify these uncertainties, Nereis oligohalina is redescribed based on specimens from the Mexican Gulf of Mexico, including a proposed neotype; further, Nereis garwoodi is redescribed including the selection of lectotype and paralectotypes, and Nereis confusa sp. n. is described with material from the Gulf of California. A key for the identification of similar species and some comments about speciation in nereidid polychaetes are also included. PMID:26448699

  8. Influence of mode of exposure and the presence of a tubiculous polychaete on the fate of benz(a)anthracene in the benthos

    SciTech Connect

    McElroy, A.E.; Farrington, J.W.; Teal, J.M. )

    1990-11-01

    The distribution and metabolism of ({sup 14}C-12)benz(a)-anthracene (BA) was followed in benthic microcosms in the presence and absence of the polychaete Nereis virens for periods of 4-25 days to simultaneously assess the effects of mode of introduction and the presence of large burrowing organisms on the fate of polycyclic aromatic hydrocarbons (PAH) and their metabolites in the benthos. Radiolabeled BA was added to the chambers in three ways: already sorbed to the entire sediment reservoir, directly into the water column, or incorporated into food for the worms. BA added to the water column was more available for uptake and metabolism by worms and microbial mineralization to CO{sub 2} than BA previously sorbed to the entire sediment reservoir. In experiments with the sediment reservoir uniformly labeled with BA, worms increased flux of BA from the sediment, and with time, their presence led to increased rates of microbial mineralization of BA to CO{sub 2}. Dietary BA was most rapidly metabolized by Nereis.

  9. Zinc and mechanical prowess in the jaws of Nereis, a marine worm

    SciTech Connect

    Lichtenegger, Helga C.; Schoberl, Thomas; Ruokolainen, Janne T.; Cross, Julie O.; Heald, Steve M.; Birkedal, Henrik; Waite, J. Herbert; Stucky, Galen

    2003-08-05

    Higher animals typically rely on calcification to harden certain tissues such as bones and teeth. Some notable exceptions can be found in invertebrates: The fangs, teeth, and mandibles of diverse arthropod species have been reported to contain high levels of zinc. Considerable quantities of zinc also occur in the jaws of the marine polychaete worm Nereis sp. High copper levels in the polychaete worm Glycera dibranchiata recently were attributed to a copper-based biomineral reinforcing the jaws. In the present article, we attempt to unravel the role of zinc in Nereis limbata jaws, using a combination of position-resolved state-of-the-art techniques. It is shown that the local hardness and stiffness of the jaws correlate with the local zinc concentration, pointing toward a structural role for zinc. Zinc always is detected in tight correlation with chlorine, suggesting the presence of a zinc-chlorine compound. No crystalline inorganic phase was found, however, and results from x-ray absorption spectroscopy further exclude the presence of simple inorganic zinc-chlorine compounds in amorphous form. The correlation of local histidine levels in the protein matrix and zinc concentration leads us to hypothesize a direct coordination of zinc and chlorine to the protein. A comparison of the role of the transition metals zinc and copper in the jaws of two polychaete worm species Nereis and Glycera, respectively, is presented.

  10. Zinc and mechanical prowess in the jaws of Nereis, a marine worm

    SciTech Connect

    Lichtenegger, Helga C.; Schoberl, Thomas; Ruokolainen, Janne T.; Cross, Julie O.; Heald, Steve M.; Birkedal, Henrik; Waite, J. Herbert; Stucky, Galen

    2003-08-05

    Higher animals typically rely on calcification to harden certain tissues such as bones and teeth. Some notable exceptions can be found in invertebrates: The fangs, teeth, and mandibles of diverse arthropod species have been reported to contain high levels of zinc. Considerable quantities of zinc also occur in the jaws of the marine polychaete worm Nereis sp. High copper levels in the polychaete worm Glycera dibranchiata recently were attributed to a copper-based biomineral reinforcing the jaws. In the present article, we attempt to unravel the role of zinc in Nereis limbata jaws, using a combination of position-resolved state-of-the-art techniques. It is shown that the local hardness and stiffness of the jaws correlate with the local zinc concentration, pointing toward a structural role for zinc. Zinc always is detected in tight correlation with chlorine, suggesting the presence of a zinc– chlorine compound. No crystalline inorganic phase was found, however, and results from x-ray absorption spectroscopy further exclude the presence of simple inorganic zinc– chlorine compounds in amorphous form. The correlation of local histidine levels in the protein matrix and zinc concentration leads us to hypothesize a direct coordination of zinc and chlorine to the protein. A comparison of the role of the transition metals zinc and copper in the jaws of two polychaete worm species Nereis and Glycera, respectively, is presented.

  11. Effects of Hypoxia on Animal Burrow Constraction and Consequent Effects on Sediment Redox Profiles (SETAC08)

    EPA Science Inventory

    We investigated the effects of mild hypoxia on the burrowing behavior of three marine species (the hard clam Mercenaria mercenaria, the polychaete worm Nereis virens, and the amphipod Leptocheirus plumulosus) and consequent effects on sediment redox profiles. Animals were introdu...

  12. INFLUENCE OF SOOT CARBON ON THE BIOACCULUMATION OF SEDIMENT-BOUND POLYCYCLIC AROMATIC HYDROCARBONS BY MARINE BENTHIC INVERTEBRATES: AN INTERSPECIES COMPARISON

    EPA Science Inventory

    The sorption of polycyclic aromatic hydrocarbons (PAHs) to soot carbon in marine sediments has been hypothesized to reduce PAH bioavailability. This hypothesis was tested for eight species of marine benthic invertebrates (four polychaete worms, Clymenella torquata, Nereis virens,...

  13. Three novel cytochrome P450 genes identified in the marine polychaete Perinereis nuntia and their transcriptional response to xenobiotics.

    PubMed

    Zheng, Senlin; Chen, Bin; Qiu, Xiaoyan; Lin, Kangli; Yu, Xingguang

    2013-06-15

    Polychaetes have previously been used as bioindicators of environmental pollution. Their ability to eliminate organic pollutants such as polycyclic aromatic hydrocarbons (PAH) has been extensively analyzed. However, the cytochrome P450 monooxygenases (CYP) genes in polychaetes, which catalyze the first step of oxidative degradation of PAHs, have received little attention. Based on the partial sequences of three CYP genes that were enriched by subtractive cDNA libraries of the polychaete Perinereis nuntia, we amplified and sequenced the full-length cDNA of these novel CYP genes. These genes were named CYP4BB2, CYP423A1 and CYP424A1 by the Cytochrome P450 Nomenclature Committee. The deduced amino acid sequence of CYP4BB2 in P. nuntia showed 68% sequence identity to CYP4BB1 in Nereis virens, and was listed as a new member of the CYP4BB subfamily. The sequence of CYP423A1 and CYP424A1 both share less than 40% sequence identity to all known CYP enzymes and were classed into new CYP families. CYP family members are composite parts of a larger group called a clan. CYP4BB2 and CYP424A1 are listed as CYP4 clan members, while CYP423A1 is of the CYP2 clan. The 3D structures of these P. nuntia CYPs were successfully predicted by homology-modeling using the SWISS-MODEL workspace. The models of CYP424A1 and CYP4BB2 were created using 1jpzB (CYP102A) as a template, while CYP423A1 utilized 3czhB (CYP2R1) as its template. The presence of characteristic CYP superfamily motifs, such as the F-G⋯C-G amino acid sequence, and the conservation of the three-dimensional CYP structure shown by the modeling, suggested that these novel P. nuntia CYP genes may contain conserved functional domains of CYP monooxygenases. To examine the effect of xenobiotics on living organisms, we analyzed the transcriptional levels of these three new CYP genes in sandworms (P. nuntia) exposed to seawater artificially contaminated with benzo[a]pyrene (BaP). We also exposed individuals to industrial wastewater

  14. Chronic sublethal effects of San Francisco Bay sediments on Nereis (neanthes) arenaceodentata: Non treatment factors. Final report

    SciTech Connect

    Moore, D.W.; Dillon, T.M.

    1992-09-01

    Initial development of a chronic sublethal sediment bioassay with the polychaete Nereis (Neanthes) arenaceodentata is described. The test was initiated with 2 to 3-week-old postemergent juvenile worms and terminated after 21 days. The sublethal test end point was estimated individual somatic growth rate (milligrams dry weight/day). The potential bias due to selected nontreatment factors on polychaete survival and growth was evaluated. For example, grain size had no effect, while the number of worms added to each exposure vessel was critical. Direct transfer from 30 ppt to salinities < or = ppt had a highly significant and adverse effect on survival and growth. Both survival and growth of juvenile worms may be adversely affected if test conditions involve exposures to > or = mg/L ammonia or > or = mg/L hydrogen sulfide.... Chronic, Growth, Neanthes, Sediment, Sublethal.

  15. From biomarkers to population responses in Nereis diversicolor: assessment of stress in estuarine ecosystems.

    PubMed

    Durou, Cyril; Smith, Brian D; Roméo, Michèle; Rainbow, Philip S; Mouneyrac, Catherine; Mouloud, Mohamed; Gnassia-Barelli, Mauricette; Gillet, Patrick; Deutch, Bruno; Amiard-Triquet, Claude

    2007-03-01

    Suborganismal responses to toxicants can be sensitive tools to assess marine pollution, but their ecological significance is a matter of debate. Among these biomarkers, those linked to reproduction are most probably related to populational effects. To test this hypothesis, Nereis diversicolor were collected in the multipolluted Seine estuary and the comparatively clean Authie estuary (France). Energy reserves were higher in Authie worms, suggesting a better physiological status. The number of oocytes per female was higher for the polychaetes from the Authie, but it was related to the size of animals, which was higher at this site. Densities of worms were depleted in the Seine compared to those in Authie. Demographic structure of the Seine population was also altered. The concomitant changes in energy reserves, egg production, and population structure and density suggest that the effects on biomarkers and at the population level are related.

  16. New Insights into Polychaete Traces and Fecal Pellets: Another Complex Ichnotaxon?

    PubMed Central

    Kulkarni, Kantimati G.; Panchang, Rajani

    2015-01-01

    Neoichnological observations help refine paleoichnological records. The present study reports extensive observations on the distribution, morphology, occurrence and association of burrows and fecal pellets of the polychaete Nereis diversicolor in the Kundalika Estuary on the west coast of India. Our holistic study of these modern-day traces suggests it to be a complex trace arising from domichnial, fodinichnial and possibly pascichnial behavior of polychaetes. The study for the first time reports extensive fecal pellet production, distribution and their preservation as thick stacks in modern estuarine environment. These observations testify the fossilization potential of pellets and provide an explanation to their origin in the geological record. Their occurrence as strings associated with mounds not only suggests pascichnial behaviour of polychaetes but also allows the assignment of post-Paleozoic Tomaculum to the activity of polychaete worms. The production of fecal pellets in such large quantities plays a major role in increasing the average grain size of the substrate of these estuarine tidal flats, thereby improving aeration within the substrate. PMID:26439262

  17. Peptide synthetase gene in Trichoderma virens.

    PubMed

    Wilhite, S E; Lumsden, R D; Straney, D C

    2001-11-01

    Trichoderma virens (synonym, Gliocladium virens), a deuteromycete fungus, suppresses soilborne plant diseases caused by a number of fungi and is used as a biocontrol agent. Several traits that may contribute to the antagonistic interactions of T. virens with disease-causing fungi involve the production of peptide metabolites (e.g., the antibiotic gliotoxin and siderophores used for iron acquisition). We cloned a 5,056-bp partial cDNA encoding a putative peptide synthetase (Psy1) from T. virens using conserved motifs found within the adenylate domain of peptide synthetases. Sequence similarities with conserved motifs of the adenylation domain, acyl transfer, and two condensation domains support identification of the Psy1 gene as a gene that encodes a peptide synthetase. Disruption of the native Psy1 gene through gene replacement was used to identify the function of this gene. Psy1 disruptants produced normal amounts of gliotoxin but grew poorly under low-iron conditions, suggesting that Psy1 plays a role in siderophore production. Psy1 disruptants cannot produce the major T. virens siderophore dimerum acid, a dipetide of acylated N(delta)-hydroxyornithine. Biocontrol activity against damping-off diseases caused by Pythium ultimum and Rhizoctonia solani was not reduced by the Psy1 disruption, suggesting that iron competition through dimerum acid production does not contribute significantly to disease suppression activity under the conditions used.

  18. Peptide Synthetase Gene in Trichoderma virens

    PubMed Central

    Wilhite, S. E.; Lumsden, R. D.; Straney, D. C.

    2001-01-01

    Trichoderma virens (synonym, Gliocladium virens), a deuteromycete fungus, suppresses soilborne plant diseases caused by a number of fungi and is used as a biocontrol agent. Several traits that may contribute to the antagonistic interactions of T. virens with disease-causing fungi involve the production of peptide metabolites (e.g., the antibiotic gliotoxin and siderophores used for iron acquisition). We cloned a 5,056-bp partial cDNA encoding a putative peptide synthetase (Psy1) from T. virens using conserved motifs found within the adenylate domain of peptide synthetases. Sequence similarities with conserved motifs of the adenylation domain, acyl transfer, and two condensation domains support identification of the Psy1 gene as a gene that encodes a peptide synthetase. Disruption of the native Psy1 gene through gene replacement was used to identify the function of this gene. Psy1 disruptants produced normal amounts of gliotoxin but grew poorly under low-iron conditions, suggesting that Psy1 plays a role in siderophore production. Psy1 disruptants cannot produce the major T. virens siderophore dimerum acid, a dipetide of acylated Nδ-hydroxyornithine. Biocontrol activity against damping-off diseases caused by Pythium ultimum and Rhizoctonia solani was not reduced by the Psy1 disruption, suggesting that iron competition through dimerum acid production does not contribute significantly to disease suppression activity under the conditions used. PMID:11679326

  19. Alteration of organic matter during infaunal polychaete gut passage and links to sediment organic geochemistry. Part I: Amino acids

    NASA Astrophysics Data System (ADS)

    Woulds, Clare; Middelburg, Jack J.; Cowie, Greg L.

    2012-01-01

    Of the factors which control the quantity and composition of organic matter (OM) buried in marine sediments, the links between infaunal ingestion and gut passage and sediment geochemistry have received relatively little attention. This study aimed to use feeding experiments and novel isotope tracing techniques to quantify amino acid net accumulation and loss during polychaete gut passage, and to link this to patterns of selective preservation and decay in sediments. Microcosms containing either Arenicolamarina or Hediste (formerly Nereis) diversicolor were constructed from defaunated sediment and filtered estuarine water, and maintained under natural temperature and light conditions. They were fed with 13C-labelled diatoms daily for 8 days, and animals were transferred into fresh, un-labelled sediment after ∼20 days. Samples of fauna, microcosm sediment and faecal matter were collected after 8, ∼20 and ∼40 days, and analysed for their bulk isotopic signatures and 13C-labelled amino acid compositions. Bulk isotopic data showed that, consistent with their feeding modes, Hediste assimilated added 13C more quickly, and attained a higher labelling level than Arenicola. Both species retained the added 13C in their biomass even after removal from the food. A principal component analysis of 13C-labelled amino acid mole percentages showed clear differences in composition between the algae, faunal tissues, and sediment plus faecal matter. Further, the two species of polychaete showed different compositions in their tissues. The amino acids phenylalanine, valine, leucine, iso-leucine, threonine and proline showed net accumulation in polychaete tissues. Serine, methionine, lysine, aspartic and glutamic acids and tyrosine were rapidly lost through metabolism, consistent with their presence in easily digestible cell components (as opposed to cell walls which offer physical protection). All sample types (polychaete tissues, sediments and faecal matter) were enriched in

  20. Bioaccumulation and oxidative stress responses measured in the estuarine ragworm (Nereis diversicolor) exposed to dissolved, nano- and bulk-sized silver.

    PubMed

    Cozzari, Margherita; Elia, Antonia Concetta; Pacini, Nicole; Smith, Brian D; Boyle, David; Rainbow, Philip S; Khan, Farhan R

    2015-03-01

    The impact of Ag NPs on sediment-dwelling organisms has received relatively little attention, particularly in linking bioaccumulation to oxidative injury. The polychaete Nereis diversicolor was exposed to sediments spiked with dissolved Ag (added as AgNO3), Ag NPs (63 ± 27 nm) and larger bulk Ag particles (202 ± 56 μm), for up to 11 days at sublethal concentrations (nominally 2.5, 5, 10 μg Ag g(-1) sediment (dw)). There were concentration- and time-dependent differences in the accumulation of the three Ag forms, but all three forms elicited an oxidative stress response. In the cases of Ag NPs and bulk Ag particles, changes in antioxidant markers (glutathione, SOD, CAT, GPx, SeGPx, GST and GR) occurred without significant Ag accumulation. Differences in biomarker profiles between the three Ag forms suggest that the mechanism of oxidative stress caused by particulate Ag is distinct from that of dissolved Ag. PMID:25549865

  1. Burial of Zostera marina seeds in sediment inhabited by three polychaetes: Laboratory and field studies

    NASA Astrophysics Data System (ADS)

    Delefosse, M.; Kristensen, E.

    2012-07-01

    The large number of seeds produced by eelgrass, Zostera marina, provides this plant with a potential to disperse widely and colonise new areas. After dispersal, seeds must be buried into sediment for assuring long-term survival, successful germination and safe seedling development. Seeds may be buried passively by sedimentation or actively through sediment reworking by benthic fauna. We evaluated the effect of three polychaetes on the burial rate and depth of eelgrass seeds. Burial was first measured in controlled laboratory experiments using different densities of Nereis (Hediste) diversicolor (400-3200 ind m- 2), Arenicola marina (20-80 ind m- 2), and the invasive Marenzelleria viridis (400-1600 ind m- 2). The obtained results were subsequently compared with burial rates of seed mimics in experimental field plots (1 m2) dominated by the respective polychaetes. High recovery of seeds in the laboratory (97-100%) suggested that none of these polychaetes species feed on eelgrass seeds. N. diversicolor transported seeds rapidly (< 1 day) into its burrow, where they remained buried at a median depth of 0.5 cm. A. marina and M. viridis buried seeds by depositing their faeces on top of the sediment. At their highest abundance, A. marina and M. viridis buried seeds to a median depth of 6.7 cm and 0.5 cm, respectively, after a month. The burial efficiency and depth of these species were, in contrast to N. diversicolor, dependent on animal abundance. Only 2% of seed mimics casted in the field plots were recovered, suggesting that physical dispersion by waves and currents was considerably important for horizontal distribution. However, polychaete affected significantly the vertical distribution of seeds. Overall the effects of these three polychaetes indicate that benthic macroinvertebrates may significantly impact eelgrass seed bank at the ecosystem scale. Some species have a positive effect by burying seeds to shallow depths and thereby reducing seed predation and

  2. Chronic sublethal effects of San Francisco Bay sediments on nereis (neanthes) arenaceodentata; bioaccumulation from bedded sediments. Final report

    SciTech Connect

    Moore, D.; Dillon, T.M.

    1993-09-01

    In previous studies with San Francisco Bay sediments, minimal chronic sublethal effects were detected (Miscellaneous Paper D-93-1 and another Miscellaneous Paper in preparation by Moore and Dillon). To ensure that the lack of effects was not due to a lack of contaminant uptake, a bioaccumulation experiment was conducted. Bioaccumulation from bedded sediments was evaluated following a 9-week exposure with the marine polychaete worm Nereis (Neanthes) arenaceodentata. Two sediments were evaluated, a contaminated San Francisco Bay test sediment and a clean control sediment from Sequim, WA. Animals were exposed as early juveniles through adulthood. Tissues were analyzed for metals, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and pesticides. Worms exposed to the contaminated San Francisco Bay sediment had significantly higher tissue residues of silver (0.30 mg/kg dry weight) and tributyltin (0.298 mg/kg dry weight). Conversely, tissue residues of control animals were significantly higher in cadmium (0.67 mg/kg dry weight) and lead (1.89 mg/kg dry weight). Small Amounts (0.02 mg/kg dry weight) of aldrin and dieldrin were measured in worms exposed to the contaminated sediment, while dieldrin and 8-BHC were found in Bioaccumulation, Neanthes, Chronic sublethal, San Francisco Bay, Dredged, Material, Sediment.

  3. Bioavailability of inorganic and methylmercury to a marine deposit-feeding polychaete

    SciTech Connect

    Wang, W.X.; Stupakoff, I.; Gagnon, C.; Fisher, N.S.

    1998-09-01

    The authors measured the assimilation efficiencies (AEs) from various types of sediments and the uptake rate constants from the dissolved phase of inorganic mercury (Hg(II)) and methylmercury (CH{sub 3}Hg(II)) in the marine deposit-feeding polychaete Nereis succinea. AEs of Hg(II) ranged between 7 and 30% and were unaffected by sediment composition, whereas AEs of CH{sub 3}Hg(II) ranged between 43 and 83% and were strongly affected by sediment composition. Sediment grain size had no apparent effect on Hg(II) and Ch{sub 3}Hg(II) assimilation. AEs for Hg(II) associated with anoxic sediment were slightly lower than with oxic sediment, whereas CH{sub 3}Hg(II) displayed comparable AEs for both oxic and anoxic sediment. Dissolved uptake rate constants of CH{sub 3}Hg(II) were 2.2 times those of Hg(II). A bioenergetic-based kinetic model was used to separate the pathways (solute vs sediment) and sources [Hg(II) vs CH{sub 3}Hg(II)] of Hg accumulation in N. succinea. The model predicted that, under conditions typical of coastal sediment environments, CH{sub 3}Hg(II) accumulation contributes about 5--17% of total Hg accumulation in polychaetes. Most of the Hg(II) (>70%) accumulation is predicted to derive from sediment ingestion, whereas for CH{sub 3}Hg(II) the relative importance of dissolved vs sediment ingestion depends greatly on its partition coefficient for sediments. Uptake from the dissolved phase and sediment ingestion can be equally important for CH{sub 3}Hg(II) accumulation in N. succinea.

  4. Polychaete burrows harbour distinct microbial communities in oil-contaminated coastal sediments.

    PubMed

    Taylor, Joe D; Cunliffe, Michael

    2015-08-01

    Previous studies have shown that the bioturbating polychaete Hediste (Nereis) diversicolor can affect the composition of bacterial communities in oil-contaminated sediments, but have not considered diversity specifically within bioturbator burrows or the impact on microbial eukaryotes. We tested the hypothesis that H. diversicolor burrows harbour different eukaryotic and bacterial communities compared with un-bioturbated sediment, and that bioturbation stimulates oil degradation. Oil-contaminated sediment was incubated with or without H. diversicolor for 30 days, after which sediment un-affected by H. diversicolor and burrow DNA/RNA samples were analysed using quantitative reverse transcription PCR (Q-RT-PCR) and high-throughput sequencing. Fungi dominated both burrow and un-bioturbated sediment sequence libraries; however, there was significant enrichment of bacterivorous protists and nematodes in the burrows. There were also significant differences between the bacterial communities in burrows compared with un-bioturbated sediment. Increased activity and relative abundance of aerobic hydrocarbon-degrading bacteria in the burrows coincided with the significant reduction in hydrocarbon concentration in the bioturbated sediment. This study represents the first detailed assessment of the effect of bioturbation on total microbial communities in oil-contaminated sediments. In addition, it further shows that bioturbation is a significant factor in determining microbial diversity within polluted sediments and plays an important role in stimulating bioremediation.

  5. 40 CFR 180.1310 - Trichoderma virens strain G-41; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Trichoderma virens strain G-41... RESIDUES IN FOOD Exemptions From Tolerances § 180.1310 Trichoderma virens strain G-41; exemption from the... Trichoderma virens strain G-41, in or on all food commodities, when applied as a fungicide and used...

  6. 40 CFR 180.1310 - Trichoderma virens strain G-41; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Trichoderma virens strain G-41... RESIDUES IN FOOD Exemptions From Tolerances § 180.1310 Trichoderma virens strain G-41; exemption from the... Trichoderma virens strain G-41, in or on all food commodities, when applied as a fungicide and used...

  7. 40 CFR 180.1310 - Trichoderma virens strain G-41; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Trichoderma virens strain G-41... RESIDUES IN FOOD Exemptions From Tolerances § 180.1310 Trichoderma virens strain G-41; exemption from the... Trichoderma virens strain G-41, in or on all food commodities, when applied as a fungicide and used...

  8. Chronic sublethal effects of San Francisco Bay sediments on nereis (neanthes) arenaceodentata; effect of food ration on sediment toxicity. Final report

    SciTech Connect

    Moore, D.W.; Dillon, T.M.

    1993-09-01

    This report is designed to address concerns regarding the effect of food ration on toxicity during chronic sublethal sediment bioassays. To this end, a contaminated San Francisco Bay sediment and a clean control sediment were evaluated in a chronic sublethal test under a series of different food rations, with the marine polychaete worm Nereis (Neanthes) arenaceodentata. Animals were exposed from early juvenile stage through the onset of gametogenesis. Treatments were 2.OX, 1.OX, 0.5X, and 0.25X where X is the recommended food ration for laboratory cultures. Test end points were survival, growth, and reproduction. The contaminated sediment was a composite of several cores taken to project depth (38 ft (11.6 m) below mean low water mark) from an area in Oakland Inner Harbor known to be contaminated with polycyclic aromatic hydrocarbons and metals. Comparisons were made with a clean control sediment. The control sediment is used in the laboratory cultures of N. arenaceodentata and was collected from Sequim, WA. Mean percent survival of Neanthes was high (>90 percent) in both the contaminated and control sediment across all food ration treatments. Individual wet weights were significantly reduced with decreasing food ration in both contaminated and control sediments. Significant differences in wet weight between sediment types were observed at the 1.OX, 0.5X, and 0.25X rations. Reproduction (fecundity and emergent juvenile (EJ) production) was also Chronic sublethal, Neanthes, Dredged material, San Francisco Bay, Food ration, Sediment.

  9. Lizard Island Polychaete Workshop: sampling sites and a checklist of polychaetes.

    PubMed

    Ribas, Julia; Hutchings, Pat

    2015-01-01

    In August 2013, a two week polychaete workshop was held at Lizard Island, Great Barrier Reef. Twenty-one sites representing 121 collection events were sampled for polychetes around Lizard and on the Outer Barrier. Workshop participants sorted polychaetes to family and each participant received on loan selected families to work up. This Zootaxa monograph describes 91 new species, 67 new records for Lizard Island, and 19 for Australia. Details regarding the habitats and locations are provided in Table 2 together with two maps (Figs 1, 2) showing sampling locations. In this paper we also list previously collected polychaete material from the region together with any published records for families which are not included in this volume. PMID:26624064

  10. Lizard Island Polychaete Workshop: sampling sites and a checklist of polychaetes.

    PubMed

    Ribas, Julia; Hutchings, Pat

    2015-09-18

    In August 2013, a two week polychaete workshop was held at Lizard Island, Great Barrier Reef. Twenty-one sites representing 121 collection events were sampled for polychetes around Lizard and on the Outer Barrier. Workshop participants sorted polychaetes to family and each participant received on loan selected families to work up. This Zootaxa monograph describes 91 new species, 67 new records for Lizard Island, and 19 for Australia. Details regarding the habitats and locations are provided in Table 2 together with two maps (Figs 1, 2) showing sampling locations. In this paper we also list previously collected polychaete material from the region together with any published records for families which are not included in this volume.

  11. California sea otter (Enhydra lutris nereis) census results, Spring 2016

    USGS Publications Warehouse

    Tinker, M. Tim; Hatfield, Brian B.

    2016-09-19

    The 2016 census of southern sea otters Enhydra lutris nereis was conducted in May along the mainland coast of central California and in April at San Nicolas Island in southern California. The 3-year average of combined counts from the mainland range and San Nicolas Island was 3,272. This is the first year that the official index has exceeded 3,090, the Endangered Species Act delisting threshold suggested by the U.S. Fish and Wildlife Service (the threshold would need to be exceeded for 3 consecutive years before delisting consideration). The 5-year average trend in abundance, including both the mainland range and San Nicolas Island populations, is positive at 3.2 percent per year; however, regional trends vary, with localized declines at the southern and northern peripheries of the mainland range. The lack of population growth in the range peripheries over recent years likely explains the cessation of range expansion, with the range limits remaining almost unchanged from the previous 5 years.

  12. Trophic transfer of trace metals: Subcellular compartmentalization in a polychaete and assimilation by a decapod crustacean

    USGS Publications Warehouse

    Rainbow, P.S.; Poirier, L.; Smith, B.D.; Brix, K.V.; Luoma, S.N.

    2006-01-01

    The chemical form of accumulated trace metal in prey is important in controlling the bioavailataility of dietary metal to a predator. This study investigated the trophic transfer of radiolabelled Ag, Cd and Zn from the polychaete worm Nereis diversicolor to the decapod crustacean Palaemonetes varians. We used 2 populations of worms with different proportions of accumulated metals in different subcellular fractions as prey, and loaded the worms with radiolabelled metals either from sediment or from solution. Accumulated radiolabelled metals were fractionated into 5 components : metal-rich granules (MRG), cellular debris, organelles, metallothionein-like proteins (MTLP), and other (heat-sensitive) proteins (HSP). Assimilation efficiencies (AE) of the metals by P. varians were measured from the 4 categories of prey (i.e. 2 populations, radiolabelled from sediment or solution). There were significant differences for each metal between the AEs from the different prey categories, confirming that origin of prey and route of uptake of accumulated trace metal will cause intraspecific differences in subsequent metal assimilation. Correlations were sought between AEs and selected fractions or combinations of fractions of metals in the prey-MRG, Trophically Available Metal (TAM = MTLP + HSP + organelles) and total protein (MTLP + HSP). TAM explained 28% of the variance in AEs for Ag, but no consistent relationships emerged between AEs and TAM or total protein when the metals were considered separately. AEs did, however, show significant positive regressions with both TAM and total protein when the 3 metals were considered together, explaining only about 21 % of the variance in each case. A significant negative relationship was observed between MRG and AE for all metals combined. The predator (P. varians) can assimilate dietary metal from a range of the fractions binding metals in the prey (N. diversicolor), with different assimilation efficiencies summated across these

  13. Trophic structure of polychaetes around an offshore gas platform.

    PubMed

    Punzo, E; Strafella, P; Scarcella, G; Spagnolo, A; De Biasi, A M; Fabi, G

    2015-10-15

    The distribution of polychaetes associated with an offshore gas platform built on a muddy-sandy bottom in the northern Adriatic Sea was investigated with emphasis on their feeding structure. Polychaete species were collected at different distances from the rig using a Van Veen grab. Assessment of the polychaete community and trophic groups for impacts related to the presence of the platform demonstrated significantly different abundances at rising distances from the rig. The present findings highlight an effect of the rig on the spatial distribution of polychaete assemblages. Even though the effects of gas platforms on surrounding benthic communities have been investigated in the Adriatic Sea, no studies have addressed the distribution of polychaete trophic groups along a gradient based on distance from the rig. PMID:26219685

  14. Polychaete species (Annelida) described from the Philippine and China Seas.

    PubMed

    Salazar-Vallejo, Sergio I; Carrera-Parra, Luis F; Muir, Alexander I; De León-González, Jesús Angel; Piotrowski, Christina; Sato, Masanori

    2014-07-30

    The South China and Philippine Seas are among the most diverse regions in the Western Pacific. Although there are several local polychaete checklists available, there is none comprising the whole of this region. Presented herein is a comprehensive list of the original names of all polychaete species described from the region. The list contains 1037 species, 345 genera and 60 families; the type locality, type depository, and information regarding synonymy are presented for each species. 

  15. Identification and Characterization of Plant Cell Death-Inducing Secreted Proteins From Ustilaginoidea virens.

    PubMed

    Fang, Anfei; Han, Yanqing; Zhang, Nan; Zhang, Min; Liu, Lijuan; Li, Shuai; Lu, Fen; Sun, Wenxian

    2016-05-01

    Ustilaginoidea virens (Cooke) Takah (telemorph Villosiclava virens) is an ascomycetous fungus that causes rice false smut, one of the most important rice diseases. Fungal effectors often play essential roles in host-pathogen coevolutionary interactions. However, little is known about the functions of U. virens effectors. Here, we performed functional studies on putative effectors in U. virens and demonstrated that 13 of 119 putative effectors caused necrosis or necrosis-like phenotypes in Nicotiana benthamiana. Among them, 11 proteins were confirmed to be secreted, using a yeast secretion system, and the corresponding genes are all highly induced during infection, except UV_44 and UV_4753. Eight secreted proteins were proven to trigger cell death or defenses in rice protoplasts and the secretion signal of these proteins is essential for their cell death-inducing activity. The ability of UV_44 and UV_1423 to trigger cell death is dependent on the predicted serine peptidase and ribonuclease catalytic active sites, respectively. We demonstrated that UV_1423 and UV_6205 are N-glycosylated proteins, which glycosylation has different impacts on their abilities to induce cell death. Collectively, the study identified multiple secreted proteins in U. virens with specific structural motifs that induce cell death or defense machinery in nonhost and host plants. PMID:26927000

  16. Optimization of extraction of phenolics from leaves of Ficus virens *

    PubMed Central

    Chen, Xiao-xin; Wu, Xiao-bing; Chai, Wei-ming; Feng, Hui-ling; Shi, Yan; Zhou, Han-tao; Chen, Qing-xi

    2013-01-01

    In this research, the conditions for extraction of phenolics from leaves of Ficus virens were optimized using response surface methodology (RSM). The extraction abilities of phenolics (EAP) and flavonoids (EAF), the 2,2-diphenyl-1-pierylhydrazyl (DPPH) free-radical scavenging potential, and the ferric reducing/antioxidant power (FRAP) were used as quality indicators. The results of single-factor experiments showed that temperature, ethanol concentration, extraction time, and the number of extraction cycles were the main influencing variables, and these provided key information for the central composite design. The results of RSM fitted well to a second degree polynomial model and more than 98% of the variability was explained. The ideal extraction conditions for EAP, EAF, DPPH free-radical scavenging potential, and FRAP were obtained. Considering the four quality indicators overall, the ideal extraction conditions were 58% ethanol at 57 °C for 37 min with three extraction cycles. At the ideal extraction conditions, the values of EAP, EAF, DPPH free-radical scavenging potential, and FRAP were 5.72%, 3.09%, 58.88 mg ascorbic acid equivalent (AAE)/g dry weight (DW), and 15.86 mg AAE/g DW, respectively. In addition, linear correlations were observed between EAP, EAF, and antioxidant potential. PMID:24101207

  17. Physiological responses of Pinus sylvestris var. mongolica seedlings to the interaction between Suillus luteus and Trichoderma virens.

    PubMed

    Yin, D; Deng, X; Chet, Ilan; Song, R

    2014-09-01

    The effects of the interaction between Suillus luteus (L.) Roussel and Trichoderma virens (J.H. Mill., Giddens & A.A. Foster) Arx on Pinus sylvestris var. mongolica Litv. were studied using plant physiology, mycorrhizal science, forest pathology, and biochemistry. Seedling growth and physiological parameters were determined, including the colonization rate of mycorrhizal fungi, biomass, root activity, photosynthetic pigment content, soluble protein content, antioxidant enzyme activities, rhizosphere soil enzyme activities, and protective enzyme activities. In addition, an optimal resistance system involving T. virens, mycorrhizal fungus (S. luteus), and P. sylvestris var. mongolica seedlings was constructed. Synergies between S. luteus and T. virens were observed, and most of the parameters of P. sylvestris var. mongolica seedlings inoculated with S. luteus 30 days + T. virens were higher than other treatments. After three months, when compared the control, the S. luteus 30 days + T. virens treatment gave increases in height (42.3 %); collar diameter (66.7 %); fresh weight (54 %); dry weight (50 %); soluble protein content (69.86 %); root activity (150 %); chlorophyll a (77.6 %); chlorophyll b (70.5 %); carotenoids (144 %); CAT activity (876.9 %); POD activity (268.3 %); SOD activity (66.18 %); β-1,3-glucanase activity (125.8 %); chitinase activity (40 %); rhizosphere soil catalase activity (97.8 %); and phosphatase activity (266.7 %). These results indicate that there may be a stimulating factor between S. luteus and T. virens when they are inoculated together (S. luteus 30 days + T. virens).

  18. A paralog of the proteinaceous elicitor sm1 affects colonization of maize roots by Trichoderma virens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The biocontrol agent, Trichoderma virens, has the ability to protect plants from pathogens by eliciting plant defense responses, involvement in mycoparasitism, or secreting antagonistic secondary metabolites. SM1, an elicitor of induced systemic resistance (ISR), was found to have three paralogs wi...

  19. [Isolation and characterization of 27 polymorphic microsatellite markers in Armillaria luteo-virens ( Physalacriaceae)].

    PubMed

    Xing, Rui; Gao, Qingbo; Zhang, Faqi; Li, Yinhu; Ful, Pengcheng; Zhang, Jinhua; Wang, Jiuli; Chen, Shilong

    2014-09-01

    [OBJECTIVE] The objectives of this study were to use Roche 454 GS FLX system to develop SSR markers for Armillaria luteo-virens. These datasets will be valuable for detecting genetic diversity and population structure of this species. [METHODS] We collected Armillaria luteo-virens samples from Yushu in Qinghai province, China. Total RNA was isolated by using the TRIzol reagent, after that we constructed cDNA library and performed one quarter plate of the whole run 454 pyrosequencing. We selected 98 primer pairs randomly from the 321 SSRs to evaluate their application and the polymorphism across 66 individuals (Armillaria luteo-virens) representing 3 wild populations. [RESULTS] Roche 454 sequencing yielded 197,121 reads with a total nucleotide size of 88,585,965bp. 27 of 98 SSRs loci were polymorphic. Numbers of alleles (Na) ranged from 2 to 8. Expected heterozygosity (HE) ranged from less than 0. 001 to 0. 810 at locus ALV65, while observed heterozygosity (Ho) from 0 at loci AIV64 and AIV92 to 0. 900 at loci ALV8. We found no evidence of linkage disequiliburium, however 10 of 27 SSR markers showed significant deviation from Hardy-weinberg equilibrium. [CONCLUSION] These remaining 17 pairs of Armillaria luteo-virens SSR markers will be valuable for future research on detecting population structure and conservation of this species.

  20. Morphological structure of propagules and electrophoretic karyotype analysis of false smut Villosiclava virens in rice.

    PubMed

    Fu, Rongtao; Ding, Lei; Zhu, Jun; Li, Ping; Zheng, Ai-Ping

    2012-04-01

    The target pathogen Villosiclava virens (teleomorph: claviceps oryzae-sativae) was isolated from the infected rice, where it caused false smut. In our study, the forming processes of the chlamydospores, chlamydospore balls, conidiospores, and secondary conidiospores during the asexual reproduction were observed more precisely and in greater detail than previous descriptions. The microstructure of the infected rice kernel showed that the outer dense chlamydospores piled around the false smut balls grown on XBZ medium; moreover the sclerotia consisting of dense mycelium were found. The different morphology was observed across the different growing conditions. In addition, we observed the nuclear numbers of both the conidiospores and hyphae using 4',6-diamidino-2-phenylindole (DAPI) staining. Because the fungus has small chromosomes and the numbers were not previously known, we analyzed the electrophoretic karyotype using a pulsed field gel electrophoresis (PFGE) technique. The results showed that V. virens has at least 10 chromosomes ranging in size from 0.6 kb to 6 Mb. The V. virens genome size is estimated to be 23 Mb. Here, we report the morphological characteristics of the fungus and the process of asexual spores forming asexual propagules, along with the first analyze the molecular karyotype of V. virens. These results supply a foundation for further study of the pathogenicity and biology of this devastating pathogen. PMID:22538655

  1. Histopathological studies of sclerotia of phytopathogenic fungi parasitized by a GFP transformed Trichoderma virens antagonistic strain.

    PubMed

    Sarrocco, Sabrina; Mikkelsen, Lisbeth; Vergara, Mariarosaria; Jensen, Dan Funck; Lübeck, Mette; Vannacci, Giovanni

    2006-02-01

    The gfp gene from the jellyfish Aequorea victoria, coding for the Green Fluorescent Protein (GFP), was used as a reporter gene to transform a Trichoderma virens strain I10, characterized as having a promising biocontrol activity against a large number of phytopathogenic fungi. On the basis of molecular and biological results, a stable GFP transformant was selected for further experiments. In order to evaluate the effects of GFP transformation on mycoparasitic ability of T. virens I10, sclerotia of Sclerotium rolfsii, Sclerotinia sclerotiorum and S. minor were inoculated with the T. virens strain I10 GFP transformant or the wild type strain. Statistical analysis of percentages of decayed sclerotia showed that the transformation of the antagonistic isolate with the GFP reporter gene did not modify mycoparasitic activity against sclerotia. Sclerotium colonization was followed by fluorescent microscopy revealing intracellular growth of the antagonist in the cortex (S. rolfsii) and inter-cellular growth in the medulla (S. rolfsii, and S. sclerotiorum). The uniformly distributed mycelium of T. virens just beneath the rind of sclerotia of both S. rolfsii and S. sclerotiorum suggests that the sclerotia became infected at numerous randomly distributed locations without any preferential point of entry. PMID:16388938

  2. TCDD/TCDF levels in bioaccumulation test tissues and their corresponding sediments

    SciTech Connect

    Schrock, M.E.; Barrows, E.S.

    1995-12-31

    Sediments from eight highly urbanized, industrial areas were analyzed for 2,3,7,8-tetrachlorodibenzo-p-dioxin and 2,3,7,8 tetrachlorodibenzofuran (TCDD/TCDF) contamination. The polychaete Nereis virens was exposed to the contaminated sediment for 28 days and then analyzed for TCDD/TCDF to evaluate the potential bioaccumulation of these contaminants, Levels of TCDD/TCDF accumulated in N. virens in general increased as the amount of sediment contamination increased and were significantly greater than levels in N. virens exposed to uncontaminated sediment. In addition, accumulation factors were calculated based on the levels of TCDD/TCDF in the test organisms and sediments, the organism lipid content, and the sediment total organic carbon content to predict the maximum amount of TCDD/TCDF likely to be accumulated from the sediments.

  3. Neurogenesis suggests independent evolution of opercula in serpulid polychaetes

    PubMed Central

    2009-01-01

    Background The internal phylogenetic relationships of Annelida, one of the key lophotrochozoan lineages, are still heavily debated. Recent molecular analyses suggest that morphologically distinct groups, such as the polychaetes, are paraphyletic assemblages, thus questioning the homology of a number of polychaete morphological characters. Serpulid polychaetes are typically recognized by having fused anterior ends bearing a tentacular crown and an operculum. The latter is commonly viewed as a modified tentacle (= radiole) and is often used as an important diagnostic character in serpulid systematics. Results By reconstructing the developmental neuroanatomy of the serpulid polychaete Spirorbis cf. spirorbis (Spirorbinae), we found striking differences in the overall neural architecture, the innervation pattern, and the ontogenetic establishment of the nervous supply of the operculum and the radioles in this species. Accordingly, the spirorbin operculum might not be homologous to the radioles or to the opercula of other serpulid taxa such as Serpula and Pomatoceros and is thus probably not a part of the tentacular crown. Conclusion We demonstrate that common morphological traits such as the prostomial appendages may have evolved independently in respective serpulid sublineages and therefore require reassessment before being used in phylogenetic analyses. Our findings corroborate recent molecular studies that argue for a revision of serpulid systematics. In addition, our data on Spirorbis neurogenesis provide a novel set of characters that highlight the developmental plasticity of the segmented annelid nervous system. PMID:19930667

  4. Comparative transcriptome analysis of fruiting body and sporulating mycelia of Villosiclava virens reveals genes with putative functions in sexual reproduction.

    PubMed

    Yu, Jun-Jie; Yu, Mi-Na; Nie, Ya-Feng; Sun, Wen-Xian; Yin, Xiao-Le; Zhao, Jie; Wang, Ya-Hui; Ding, Hui; Qi, Zhong-Qiang; Du, Yan; Huang, Li; Liu, Yong-Feng

    2016-08-01

    Sexual reproduction of heterothallic clavicipitaceous fungus Villosiclava virens (anamorph: Ustilaginoidea virens) generates ascospores, which is considered as primary infection source of rice false smut disease. However, little is known about the molecular underpinnings of sexual reproduction in V. virens. In this study, transcriptomes of V. virens in fruiting body (FB) and sporulating mycelia (SM) were compared using Illumina paired-end sequencing technology. A total of 33,384,588 and 23,765,275 clean reads of FB and SM transcriptome profiles could be used to map cDNA of V. virens, respectively. We evaluated the gene expression variations between FB and SM, a total of 488 genes therein were significantly higher expressed in FB than SM, and 342 genes were significantly higher expressed genes in SM than FB. These differentially expressed genes were annotated using Kyoto Encyclopedia of Genes and Genomes and Gene Ontology databases. Several genes were found to specifically function in sexual reproduction, involving in mating type, pheromone synthesis, signaling transduction, transcription factors, and meiosis; additionally, a few of genes were presumed to function in conidia sporulation and infection. Comparative transcriptome analysis of V. virens during FB and SM provided an overview of gene expression profiles at the transcriptional level and provided hints to better understand the molecular mechanisms of sexual development. Additionally, the data presented here also proved benefit for mining of essential genes contributing to sexual conidiation and infection.

  5. Role of gliotoxin in the symbiotic and pathogenic interactions of Trichoderma virens.

    PubMed

    Vargas, Walter A; Mukherjee, Prasun K; Laughlin, David; Wiest, Aric; Moran-Diez, Maria E; Kenerley, Charles M

    2014-10-01

    Using a gene disruption strategy, we generated mutants in the gliP locus of the plant-beneficial fungus Trichoderma virens that were no longer capable of producing gliotoxin. Phenotypic assays demonstrated that the gliP-disrupted mutants grew faster, were more sensitive to oxidative stress and exhibited a sparse colony edge compared with the WT strain. In a plate confrontation assay, the mutants deficient in gliotoxin production were ineffective as mycoparasites against the oomycete, Pythium ultimum, and the necrotrophic fungal pathogen, Sclerotinia sclerotiorum, but retained mycoparasitic ability against Rhizoctonia solani. Biocontrol assays in soil showed that the mutants were incapable of protecting cotton seedlings from attack by P. ultimum, against which the WT strain was highly effective. The mutants, however, were as effective as the WT strain in protecting cotton seedlings against R. solani. Loss of gliotoxin production also resulted in a reduced ability of the mutants to attack the sclerotia of S. sclerotiorum compared with the WT. The addition of exogenous gliotoxin to the sclerotia colonized by the mutants partially restored their degradative abilities. Interestingly, as in Aspergillus fumigatus, an opportunistic human pathogen, gliotoxin was found to be involved in pathogenicity of T. virens against larvae of the wax moth, Galleria mellonella. The loss of gliotoxin production in T. virens was restored by complementation with the gliP gene from A. fumigatus. We have, thus, demonstrated that the putative gliP cluster of T. virens is responsible for the biosynthesis of gliotoxin, and gliotoxin is involved in mycoparasitism and biocontrol properties of this plant-beneficial fungus.

  6. Role of gliotoxin in the symbiotic and pathogenic interactions of Trichoderma virens.

    PubMed

    Vargas, Walter A; Mukherjee, Prasun K; Laughlin, David; Wiest, Aric; Moran-Diez, Maria E; Kenerley, Charles M

    2014-10-01

    Using a gene disruption strategy, we generated mutants in the gliP locus of the plant-beneficial fungus Trichoderma virens that were no longer capable of producing gliotoxin. Phenotypic assays demonstrated that the gliP-disrupted mutants grew faster, were more sensitive to oxidative stress and exhibited a sparse colony edge compared with the WT strain. In a plate confrontation assay, the mutants deficient in gliotoxin production were ineffective as mycoparasites against the oomycete, Pythium ultimum, and the necrotrophic fungal pathogen, Sclerotinia sclerotiorum, but retained mycoparasitic ability against Rhizoctonia solani. Biocontrol assays in soil showed that the mutants were incapable of protecting cotton seedlings from attack by P. ultimum, against which the WT strain was highly effective. The mutants, however, were as effective as the WT strain in protecting cotton seedlings against R. solani. Loss of gliotoxin production also resulted in a reduced ability of the mutants to attack the sclerotia of S. sclerotiorum compared with the WT. The addition of exogenous gliotoxin to the sclerotia colonized by the mutants partially restored their degradative abilities. Interestingly, as in Aspergillus fumigatus, an opportunistic human pathogen, gliotoxin was found to be involved in pathogenicity of T. virens against larvae of the wax moth, Galleria mellonella. The loss of gliotoxin production in T. virens was restored by complementation with the gliP gene from A. fumigatus. We have, thus, demonstrated that the putative gliP cluster of T. virens is responsible for the biosynthesis of gliotoxin, and gliotoxin is involved in mycoparasitism and biocontrol properties of this plant-beneficial fungus. PMID:25082950

  7. Characterization of mating-type loci in rice false smut fungus Villosiclava virens.

    PubMed

    Yu, Jun-jie; Sun, Wen-xian; Yu, Mi-na; Yin, Xiao-le; Meng, Xiang-kun; Zhao, Jie; Huang, Lei; Huang, Li; Liu, Yong-feng

    2015-05-01

    Ascospores of Villosiclava virens are a primary infection source of rice false smut. This phytopathogenic fungus exists in heterothallic form, and mating compatibility is regulated by mating-type locus 1 (MAT1). However, the MAT1 locus structure remains unknown. The MAT1-1 and MAT1-2 idiomorphs of V. virens were characterized and annotated on the basis of cDNA sequencing. A multiplex polymerase chain reaction (PCR) method was developed to identify the mating types of hyphae and sclerotia. The MAT1-1 locus of V. virens contains three mating-type genes: MAT1-1-1, MAT1-1-2 and MAT1-1-3, and a pseudogene similar to MAT1-2-1. The MAT1-2 locus harbors the MAT1-2-1 gene and a new mating-type gene MAT1-2-8. The mRNA of MAT1-1-1, MAT1-1-3 and MAT1-2-1, but not MAT1-1-2, was detectible by reverse transcription PCR in vegetative mycelia. However, the mRNA of MAT1-1-2 was detectible in the stroma, which is a sexual reproduction structure of V. virens. A multiplex PCR detection method was developed for the identification of the MAT1-1 and MAT1-2 idiomorphs. All 20 wild-type strains harbored either the MAT1-1 or MAT1-2 idiomorphs. Sclerotia that harbored both the MAT1-1 and MAT1-2 idiomorphs had potential to form fertile stromata, whereas those that harbored only the MAT1-1 idiomorph could not form mature stromata. PMID:25682326

  8. Villosiclava virens infects specifically rice and barley stamen filaments due to the unique host cell walls.

    PubMed

    Yong, Ming-Li; Fan, Lin-Lin; Li, Dan-Yang; Liu, Yi-Jia; Cheng, Fang-Min; Xu, Ying; Wang, Zheng-Yi; Hu, Dong-Wei

    2016-09-01

    Rice false smut, caused by the fungal pathogen Villosiclava virens, is one of the most important rice diseases in the world. Previous studies reported that the pathogen has less number of cell wall-degraded genes and attacks dominantly rice stamen filaments and extends intercellularly. To reveal why the fungus infects plant stamen filaments, inoculation test on barley was carried out with the similar protocol to rice. The experimental results showed that the fungus could penetrate quickly into barley stamen filaments and extends both intracellularly and intercellularly, usually resulting in severe damage of the stamen filament tissues. It also attacked young barley lodicules and grew intercellularly by chance. The light microscopic observations found that the epidermal and cortex cells in barley stamen filaments arranged loosely with very thick cell walls and large cell gaps. Cellulose microfibrils in barley stamen filament cell walls arranged very sparsely so that the cell walls looked like transparent. The cell walls were very soft and flexible, and often folded. However, V. virens extended dominantly in the noncellulose regions and seemed never to degrade microfibrils in barley and rice cell walls. This suggested that the unique structures of rice and barley stamen filaments should be fit for their function of elongation in anthesis, and also endow with the susceptibility to the fungus, V. virens. PMID:27357263

  9. Villosiclava virens infects specifically rice and barley stamen filaments due to the unique host cell walls.

    PubMed

    Yong, Ming-Li; Fan, Lin-Lin; Li, Dan-Yang; Liu, Yi-Jia; Cheng, Fang-Min; Xu, Ying; Wang, Zheng-Yi; Hu, Dong-Wei

    2016-09-01

    Rice false smut, caused by the fungal pathogen Villosiclava virens, is one of the most important rice diseases in the world. Previous studies reported that the pathogen has less number of cell wall-degraded genes and attacks dominantly rice stamen filaments and extends intercellularly. To reveal why the fungus infects plant stamen filaments, inoculation test on barley was carried out with the similar protocol to rice. The experimental results showed that the fungus could penetrate quickly into barley stamen filaments and extends both intracellularly and intercellularly, usually resulting in severe damage of the stamen filament tissues. It also attacked young barley lodicules and grew intercellularly by chance. The light microscopic observations found that the epidermal and cortex cells in barley stamen filaments arranged loosely with very thick cell walls and large cell gaps. Cellulose microfibrils in barley stamen filament cell walls arranged very sparsely so that the cell walls looked like transparent. The cell walls were very soft and flexible, and often folded. However, V. virens extended dominantly in the noncellulose regions and seemed never to degrade microfibrils in barley and rice cell walls. This suggested that the unique structures of rice and barley stamen filaments should be fit for their function of elongation in anthesis, and also endow with the susceptibility to the fungus, V. virens.

  10. A pyritized polychaete from the Devonian of Ontario

    PubMed Central

    Farrell, Úna C; Briggs, Derek E.G

    2006-01-01

    A polychaete from the Middle Devonian Arkona Shale at Hungry Hollow, Arkona, Ontario is preserved in three dimensions in pyrite. The prostomium bears a single median antenna, a pair of lateral antennae and a pair of ventral palps. It is assumed to be fused to a reduced peristomium. The anteriormost three pairs of trunk appendages are modified as tentacular cirri, the third long and biramous. The remainder of the finely annulated trunk bears at least 21 similar biramous parapodia, some of which preserve evidence of chaetae. The postsegmental pygidium is very small and may bear up to two pairs of cirri. The polychaete, Arkonips topororum, falls within the Palpata, Aciculata, among the crown group Phyllodocida. Its remarkable preservation highlights the potential of the Arkona Shale to yield other examples of soft-tissue preservation. PMID:17476769

  11. An Early Cambrian stem polychaete with pygidial cirri.

    PubMed

    Vinther, Jakob; Eibye-Jacobsen, Danny; Harper, David A T

    2011-12-23

    The oldest annelid fossils are polychaetes from the Cambrian Period. They are representatives of the annelid stem group and thus vital in any discussion of how we polarize the evolution of the crown group. Here, we describe a fossil polychaete from the Early Cambrian Sirius Passet fauna, Pygocirrus butyricampum gen. et sp. nov., with structures identified as pygidial cirri, which are recorded for the first time from Cambrian annelids. The body is slender and has biramous parapodia with chaetae organized in laterally oriented bundles. The presence of pygidial cirri is one of the characters that hitherto has defined the annelid crown group, which diversified during the Cambrian-Ordovician transition. The newly described fossil shows that this character had already developed within the total group by the Early Cambrian. PMID:21733871

  12. An Early Cambrian stem polychaete with pygidial cirri.

    PubMed

    Vinther, Jakob; Eibye-Jacobsen, Danny; Harper, David A T

    2011-12-23

    The oldest annelid fossils are polychaetes from the Cambrian Period. They are representatives of the annelid stem group and thus vital in any discussion of how we polarize the evolution of the crown group. Here, we describe a fossil polychaete from the Early Cambrian Sirius Passet fauna, Pygocirrus butyricampum gen. et sp. nov., with structures identified as pygidial cirri, which are recorded for the first time from Cambrian annelids. The body is slender and has biramous parapodia with chaetae organized in laterally oriented bundles. The presence of pygidial cirri is one of the characters that hitherto has defined the annelid crown group, which diversified during the Cambrian-Ordovician transition. The newly described fossil shows that this character had already developed within the total group by the Early Cambrian.

  13. Mineralization of Alvinella polychaete tubes at hydrothermal vents

    PubMed Central

    Georgieva, M N; Little, C T S; Ball, A D; Glover, A G

    2015-01-01

    Alvinellid polychaete worms form multilayered organic tubes in the hottest and most rapidly growing areas of deep-sea hydrothermal vent chimneys. Over short periods of time, these tubes can become entirely mineralized within this environment. Documenting the nature of this process in terms of the stages of mineralization, as well as the mineral textures and end products that result, is essential for our understanding of the fossilization of polychaetes at hydrothermal vents. Here, we report in detail the full mineralization of Alvinella spp. tubes collected from the East Pacific Rise, determined through the use of a wide range of imaging and analytical techniques. We propose a new model for tube mineralization, whereby mineralization begins as templating of tube layer and sublayer surfaces and results in fully mineralized tubes comprised of multiple concentric, colloform, pyrite bands. Silica appeared to preserve organic tube layers in some samples. Fine-scale features such as protein fibres, extracellular polymeric substances and two types of filamentous microbial colonies were also found to be well preserved within a subset of the tubes. The fully mineralized Alvinella spp. tubes do not closely resemble known ancient hydrothermal vent tube fossils, corroborating molecular evidence suggesting that the alvinellids are a relatively recent polychaete lineage. We also compare pyrite and silica preservation of organic tissues within hydrothermal vents to soft tissue preservation in sediments and hot springs. PMID:25556400

  14. Commensal symbiosis between agglutinated polychaetes and sulfate-reducing bacteria.

    PubMed

    Guido, A; Mastandrea, A; Rosso, A; Sanfilippo, R; Tosti, F; Riding, R; Russo, F

    2014-05-01

    Pendant bioconstructions occur within submerged caves in the Plemmirio Marine Protected Area in SE Sicily, Italy. These rigid structures, here termed biostalactites, were synsedimentarily lithified by clotted-peloidal microbial carbonate that has a high bacterial lipid biomarker content with abundant compounds derived from sulfate-reducing bacteria. The main framework builders are polychaete serpulid worms, mainly Protula with subordinate Semivermilia and Josephella. These polychaetes have lamellar and/or fibrillar wall structure. In contrast, small agglutinated terebellid tubes, which are a minor component of the biostalactites, are discontinuous and irregular with a peloidal micritic microfabric. The peloids, formed by bacterial sulfate reduction, appear to have been utilized by terebellids to construct tubes in an environment where other particulate sediment is scarce. We suggest that the bacteria obtained food from the worms in the form of fecal material and/or from the decaying tissue of surrounding organisms and that the worms obtained peloidal micrite with which to construct their tubes, either as grains and/or as tube encompassing biofilm. Peloidal worm tubes have rarely been reported in the recent but closely resemble examples in the geological record that extend back at least to the early Carboniferous. This suggests a long-lived commensal relationship between some polychaete worms and heterotrophic, especially sulfate-reducing, bacteria.

  15. Mineralization of Alvinella polychaete tubes at hydrothermal vents.

    PubMed

    Georgieva, M N; Little, C T S; Ball, A D; Glover, A G

    2015-03-01

    Alvinellid polychaete worms form multilayered organic tubes in the hottest and most rapidly growing areas of deep-sea hydrothermal vent chimneys. Over short periods of time, these tubes can become entirely mineralized within this environment. Documenting the nature of this process in terms of the stages of mineralization, as well as the mineral textures and end products that result, is essential for our understanding of the fossilization of polychaetes at hydrothermal vents. Here, we report in detail the full mineralization of Alvinella spp. tubes collected from the East Pacific Rise, determined through the use of a wide range of imaging and analytical techniques. We propose a new model for tube mineralization, whereby mineralization begins as templating of tube layer and sublayer surfaces and results in fully mineralized tubes comprised of multiple concentric, colloform, pyrite bands. Silica appeared to preserve organic tube layers in some samples. Fine-scale features such as protein fibres, extracellular polymeric substances and two types of filamentous microbial colonies were also found to be well preserved within a subset of the tubes. The fully mineralized Alvinella spp. tubes do not closely resemble known ancient hydrothermal vent tube fossils, corroborating molecular evidence suggesting that the alvinellids are a relatively recent polychaete lineage. We also compare pyrite and silica preservation of organic tissues within hydrothermal vents to soft tissue preservation in sediments and hot springs. PMID:25556400

  16. Mineralization of Alvinella polychaete tubes at hydrothermal vents.

    PubMed

    Georgieva, M N; Little, C T S; Ball, A D; Glover, A G

    2015-03-01

    Alvinellid polychaete worms form multilayered organic tubes in the hottest and most rapidly growing areas of deep-sea hydrothermal vent chimneys. Over short periods of time, these tubes can become entirely mineralized within this environment. Documenting the nature of this process in terms of the stages of mineralization, as well as the mineral textures and end products that result, is essential for our understanding of the fossilization of polychaetes at hydrothermal vents. Here, we report in detail the full mineralization of Alvinella spp. tubes collected from the East Pacific Rise, determined through the use of a wide range of imaging and analytical techniques. We propose a new model for tube mineralization, whereby mineralization begins as templating of tube layer and sublayer surfaces and results in fully mineralized tubes comprised of multiple concentric, colloform, pyrite bands. Silica appeared to preserve organic tube layers in some samples. Fine-scale features such as protein fibres, extracellular polymeric substances and two types of filamentous microbial colonies were also found to be well preserved within a subset of the tubes. The fully mineralized Alvinella spp. tubes do not closely resemble known ancient hydrothermal vent tube fossils, corroborating molecular evidence suggesting that the alvinellids are a relatively recent polychaete lineage. We also compare pyrite and silica preservation of organic tissues within hydrothermal vents to soft tissue preservation in sediments and hot springs.

  17. Modified-closed castration: a novel technique for sea otter (Enhydra lutris nereis) orchiectomies.

    PubMed

    McDermott, Alexa J; Clauss, Tonya; Sakals, Sherisse; Mejia, Johanna; Radlinsky, MaryAnn G

    2013-09-01

    A novel surgical technique was used in the routine castrations of two intact male southern sea otters, Enhydra lutris nereis, housed at the Georgia Aquarium (Atlanta, Georgia, USA). This technique involved incising the parietal vaginal tunic to allow placement of double ligation of the ductus deferens, testicular artery, and pampiniform plexus en masse. After ligating and transecting these structures, they were introduced back into the tunic, which was closed with a circumferential ligature. The incision site was closed in a routine manner. Both otters recovered well from the procedure. One otter had mild cutaneous dehiscence postoperatively, and the other had no obvious complications. Benefits of this procedure include reduced risk of ligature slippage or loosening and resultant hemorrhage, as provided by the traditional open portion of the castration, and decreased postoperative swelling, as provided by the closed part of the castration. To the authors' knowledge, this is the first time this technique has been described for use in sea otters. PMID:24063115

  18. Biological characterisation of Sarcocystis neurona isolated from a Southern sea otter (Enhydra lutris nereis)

    USGS Publications Warehouse

    Lindsay, D.S.; Thomas, N.J.; Dubey, J.P.

    2000-01-01

    Sarcocystis neurona was isolated from the brain of a juvenile, male southern sea otter (Enhydra lutris nereis) suffering from CNS disease. Schizonts and merozoites in tissue sections of the otter's brain reacted with anti-S. neurona antiserum immunohistochemically. Development in cell culture was by endopolyogeny and mature schizonts were first observed at 3 days postinoculation. PCR of merozoite DNA using primer pairs JNB33/JNB54 and restriction enzyme digestion of the 1100 bp product with Dra I indicated the organism was S. neurona. Four of four interferon-γ gene knockout mice inoculated with merozoites developed S. neurona-associated encephalitis. Antibodies to S. neurona but not Sarcocystis falcatula, Toxoplasma gondii, or Neospora caninum were present in the serum of inoculated mice. This is the first isolation of S. neurona from the brain of a non-equine host.

  19. Distribution and abundance of macrobenthic polychaetes along the South Indian coast.

    PubMed

    Musale, Amar S; Desai, Dattesh V

    2011-07-01

    Macrobenthic polychaetes play a significant role in marine benthic food chain. A study was carried out to observe the abundance and diversity of soft bottom macrobenthic polychaetes along the South Indian coast, along with observations on sediment characteristics. The present study indicated an increase in the polychaete diversity as compared to earlier reports. Sixty-three different forms of polychaetes were identified along the coast, which constitute the bulk of the macrobenthic fauna. Thirty-eight species of polychaetes showed higher abundance along the west coast, whereas 25 species showed higher abundance along the east coast. Seabed composition showed a spatial variation in its composition along the coast. Occurrence of Prionospio pinnata and Capitella capitata the deposit feeders and indicators of organic pollution suggesting the sampled area is organically rich. Polychaete abundance was found to be higher along the west coast and was attributed to loose texture of sediment due to high sand and sandy-silt resulting in higher interstitial space for organisms to harbor. Canonical correspondence analysis indicated that majority of polychaete species preferred low organic carbon, sandy silt, or sandy-clay substratum. The lower polychaete abundance at high organic carbon and high silt and clay areas can be attributed to avoidance of organisms to rich organic matter and suboxic levels, being a possible indication that these characteristics adversely affects the polychaete abundance and distribution.

  20. Survey and analysis of simple sequence repeats in the Ustilaginoidea virens genome and the development of microsatellite markers.

    PubMed

    Yu, Mina; Yu, Junjie; Li, Huanhuan; Wang, Yahui; Yin, Xiaole; Bo, Huiwen; Ding, Hui; Zhou, Yuxin; Liu, Yongfeng

    2016-07-01

    Ustilaginoidea virens is the causal agent of rice false smut, causing quantitative and qualitative losses in rice industry. However, the development and application of simple sequence repeat (SSR) markers for genetic diversity studies in U. virens were limited. This study is the first to perform large-scale development of SSR markers of this pathogen at the genome level, to (1) compare these SSR markers with those of other fungi, (2) analyze the pattern of the SSRs, and (3) obtain more informative genetic markers. U. virens is rich in SSRs, and 13,778 SSRs were identified with a relative abundance of 349.7SSRs/Mb. The most common motifs in the genome or in noncoding regions were mononucleotides, whereas trinucleotides in coding sequences. A total of 6 out of 127 primers were randomly selected to be used to analyze 115 isolates, and these 6 primers showed high polymorphism in U. virens. This study may serve as an important resource for molecular genetic studies in U. virens.

  1. Bioaccumulation of native polycyclic aromatic hydrocarbons from sediment by a polychaete and a gastropod: freely dissolved concentrations and activated carbon amendment.

    PubMed

    Cornelissen, Gerard; Breedveld, Gijs D; Naes, Kristoffer; Oen, Amy M P; Ruus, Anders

    2006-09-01

    The present paper describes a study on the bioaccumulation of native polycyclic aromatic hydrocarbons (PAHs) from three harbors in Norway using the polychaete Nereis diversicolor and the gastropod Hinia reticulata. First, biota-sediment accumulation factors (BSAFs) were measured in laboratory bioassays using the original sediments. Median BSAFs were 0.004 to 0.01 kg organic carbon/kg lipid (10 PAHs and 6 organism-sediment combinations), which was a factor of 89 to 240 below the theoretical BSAF based on total sediment contents (which is approximately one). However, if BSAFs were calculated on the basis of measured freely dissolved PAH concentrations in the pore water (measured with polyoxymethylene passive samplers), it appeared that these BSAFfree values agreed well with the measured BSAFs, within a factor of 1.7 to 4.3 (median values for 10 PAHs and six organism-sediment combinations). This means that for bioaccumulation, freely dissolved pore-water concentrations appear to be a much better measure than total sediment contents. Second, we tested the effect of 2% (of sediment dry wt) activated carbon (AC) amendments on BSAE The BSAFs were significantly reduced by a factor of six to seven for N. diversicolor in two sediments (i.e., two of six organism-sediment combinations), whereas no significant reduction was observed for H. reticulata. This implies that either site-specific evaluations of AC amendment are necessary, using several site-relevant benthic organisms, or that the physiology of H. reticulata caused artifactually high BSAF values in the presence of AC.

  2. Induction of Terpenoid Synthesis in Cotton Roots and Control of Rhizoctonia solani by Seed Treatment with Trichoderma virens.

    PubMed

    Howell, C R; Hanson, L E; Stipanovic, R D; Puckhaber, L S

    2000-03-01

    ABSTRACT Research on the mechanisms employed by the biocontrol agent Trichoderma virens to suppress cotton (Gossypium hirsutum) seedling disease incited by Rhizoctonia solani has shown that mycoparasitism and antibiotic production are not major contributors to successful biological control. In this study, we examined the possibility that seed treatment with T. virens stimulates defense responses, as indicated by the synthesis of terpenoids in cotton roots. We also examined the role of these terpenoid compounds in disease control. Analysis of extracts of cotton roots and hypocotyls grown from T. virens-treated seed showed that terpenoid synthesis and peroxidase activity were increased in the roots of treated plants, but not in the hypocotyls of these plants or in the untreated controls. Bioassay of the terpenoids for toxicity to R. solani showed that the pathway intermediates desoxyhemigossypol (dHG) and hemigossypol (HG) were strongly inhibitory to the pathogen, while the final product gossypol (G) was toxic only at a much higher concentration. Strains of T. virens and T. koningii were much more resistant to HG than was R. solani, and they thoroughly colonized the cotton roots. A comparison of biocontrol efficacy and induction of terpenoid synthesis in cotton roots by strains of T. virens, T. koningii, T. harzianum, and protoplast fusants indicated that there was a strong correlation (+0.89) between these two phenomena. It, therefore, appears that induction of defense response, particularly terpenoid synthesis, in cotton roots by T. virens may be an important mechanism in the biological control by this fungus of R. solani-incited cotton seedling disease.

  3. cAMP signalling is involved in growth, germination, mycoparasitism and secondary metabolism in Trichoderma virens.

    PubMed

    Mukherjee, Mala; Mukherjee, Prasun K; Kale, Sharad P

    2007-06-01

    An adenylate-cyclase-encoding gene, tac1, of Trichoderma virens, a soil fungus used in the biocontrol of plant pathogens, has been cloned and sequenced. The tac1 ORF spanned 7032 bp, encoding a protein of 2153 aa, which shared an identity of 65 % with the adenylate cyclase of Colletotrichum lagenarium. Deletion of tac1, through double-crossover homologous recombination, lowered the intracellular cAMP levels to below the detection limit. The mutants showed only 5-6 % of the wild-type growth rate on agar, but grew normally in shake culture. The mutants did not sporulate in darkness, and the spores failed to germinate in water. In the confrontation assay, the mutants did not overgrow the test plant pathogens Sclerotium rolfsii, Rhizoctonia solani and Pythium sp. Against Pythium sp., the mutants produced a clear zone of inhibition in the confrontation assay. HPLC analysis and bioassay showed reduced secondary metabolite production in the mutants. Using suppression subtractive hybridization (SSH), the genes that were underexpressed in the mutants were identified. Based on an array of 53 SSH library clones, 11 clones were identified as strongly downregulated in the Deltatac1 mutants; of these 11 clones, nine sequences were homologous to secondary metabolism-related gene sequences. Therefore, cAMP signalling positively regulates secondary metabolism in T. virens. This is believed to be the first direct genetic study on the role of cAMP signalling in a Trichoderma sp. Tac1 is also believed to be the first regulatory protein to be identified in T. virens that is involved in growth, germination, mycoparasitism and secondary metabolism.

  4. The role of an extracellular chitinase from Trichoderma virens Gv29-8 in the biocontrol of Rhizoctonia solani.

    PubMed

    Baek, J M; Howell, C R; Kenerley, C M

    1999-02-01

    The role of extracellular chitinase in the biocontrol activity of Trichoderma virens was examined using genetically manipulated strains of this fungus. The T. virens strains in which the chitinase gene (cht42) was disrupted (KO) or constitutively over-expressed (COE) were constructed through genetic transformation. The resulting transformants were stable and showed patterns similar to the wild-type (WT) strain with respect to growth rate, sporulation, antibiotic production, colonization efficiency on cotton roots and growth/survival in soil. Biocontrol activity of the KO and COE strains were significantly decreased and enhanced, respectively against cotton seedling disease incited by Rhizoctonia solani when compared with the WT strain.

  5. Short Communication A small B chromosome in the grasshopper Ommexecha virens (Ommexechidae).

    PubMed

    Souza, T E; Silva-Neto, L C; Santos, J F; Loreto, V; Rieger, T T

    2015-12-21

    B chromosomes, also called supernumerary or accessory chromosomes, have been characterized as extra elements found in the karyotypes of different eukaryotic species. B chromosomes are nonvital and only occur in some individuals within a species. Moreover, the chromosomes contain silenced genes, and they exhibit heterochromatinization and the accumulation of repetitive DNA and transposons. In the present study, we describe an extra chromosome in the grasshopper Ommexecha virens for the first time, using conventional staining and fluorescent in situ hybridization techniques, and we discuss the possible origin of the B chromosome.

  6. Ecdysone receptor homologs from mollusks, leeches and a polychaete worm.

    PubMed

    Laguerre, Michel; Veenstra, Jan A

    2010-11-01

    The genomes of the mollusk Lottia gigantea, the leech Helobdella robusta and the polychaete worm Capitella teleta each have a gene encoding an ecdysone receptor homolog. Publicly available genomic and EST sequences also contain evidence for ecdysone receptors in the seahare Aplysia californica, the bobtail squid Euprymna scolopes and the medicinal leech Hirudo medicinalis. Three-dimensional models of the ligand binding domains of these predicted ecdysone receptor homologs suggest that each of them could potentially bind an ecdysone-related steroid. Thus, ecdysone receptors are not limited to arthropods and nematodes.

  7. Polychaetes of an artificial reef in the central mediterranean sea

    NASA Astrophysics Data System (ADS)

    Gravina, M. F.; Ardizzone, G. D.; Belluscio, A.

    1989-02-01

    The development of a polychaete community over five years on a man-made reef was analyzed. The reef was composed of 280 concrete blocks (2 × 2 × 2 m) and located in the Tyrrhenian Sea (Italy) 1.5 miles offshore and 12-14 m deep. Sixty-three species were collected—serpulids, nereids and cirratulids being the most abundant families. Ordination by Principal Components Analysis (PCA) technique showed three main stages in the colonization process: a pioneer phase, when mainly serpulids ( Pomatoceros triqueter, P. lamarckii, Hydroides pseuduncinata) occurred; a second phase, characterized by mussel ( Mytilus galloprovincialis) dominance and a more differentiated community structure with a lot of new species especially recurring on hard bottom ( Serpula concharum, H. dianthus, Ceratonereis costae); and a third phase, with an alteration of the substratum through soft deposits and the polychaete community characterized by also the occurrence of soft bottom species ( Heteromastus filiformis, Polydora ciliata, Dorvillea rubrovittata). From the trophic point of view, the structure of the community changed from dominance by filter feeders (97%) to a more differentiated situation with abundant detritic feeders ( c. 20%). The rates of immigration and extinction and the colonization curve showed that an actual stable steady-state was not reached.

  8. A sea of worms: polychaete checklist of the Adriatic Sea.

    PubMed

    Mikac, Barbara

    2015-04-07

    The checklist of polychaetes of the Adriatic Sea (Mediterranean) based on bibliographic sources published from 1840 to 2014, as well as on novel data, with 49 new records for the area, is herein presented. The Adriatic Sea polychaete fauna comprises at present of 764 species in 360 genera and 62 families. The richest family is the Syllidae, with 112 species (c.a. 15% of the all taxa). Eight families account for as much as 50% of the diversity (Syllidae, Serpulidae, Sabellidae, Phyllodocidae, Spionidae, Polynoidae, Terebellidae and Nereididae). Among the three Adriatic sectors (Northern, Central and Southern Adriatic), the Northern Adriatic is the richest one, whereas the composition of the most diverse families is very similar in all sectors. Data on endemisms (6), aliens (29) and valid species with the type locality in the Adriatic Sea (90) are also discussed. The list of all relevant papers citing each species in the Adriatic is included, allowing future detailed information retrievals for distinct purposes. Results suggest that the number of species will keep increasing in the future, as new surveys will be undertaken, so regular updates of the present list will be necessary.

  9. A sea of worms: polychaete checklist of the Adriatic Sea.

    PubMed

    Mikac, Barbara

    2015-01-01

    The checklist of polychaetes of the Adriatic Sea (Mediterranean) based on bibliographic sources published from 1840 to 2014, as well as on novel data, with 49 new records for the area, is herein presented. The Adriatic Sea polychaete fauna comprises at present of 764 species in 360 genera and 62 families. The richest family is the Syllidae, with 112 species (c.a. 15% of the all taxa). Eight families account for as much as 50% of the diversity (Syllidae, Serpulidae, Sabellidae, Phyllodocidae, Spionidae, Polynoidae, Terebellidae and Nereididae). Among the three Adriatic sectors (Northern, Central and Southern Adriatic), the Northern Adriatic is the richest one, whereas the composition of the most diverse families is very similar in all sectors. Data on endemisms (6), aliens (29) and valid species with the type locality in the Adriatic Sea (90) are also discussed. The list of all relevant papers citing each species in the Adriatic is included, allowing future detailed information retrievals for distinct purposes. Results suggest that the number of species will keep increasing in the future, as new surveys will be undertaken, so regular updates of the present list will be necessary. PMID:25947537

  10. Polytraits: A database on biological traits of marine polychaetes

    PubMed Central

    2014-01-01

    Abstract The study of ecosystem functioning – the role which organisms play in an ecosystem – is becoming increasingly important in marine ecological research. The functional structure of a community can be represented by a set of functional traits assigned to behavioural, reproductive and morphological characteristics. The collection of these traits from the literature is however a laborious and time-consuming process, and gaps of knowledge and restricted availability of literature are a common problem. Trait data are not yet readily being shared by research communities, and even if they are, a lack of trait data repositories and standards for data formats leads to the publication of trait information in forms which cannot be processed by computers. This paper describes Polytraits (http://polytraits.lifewatchgreece.eu), a database on biological traits of marine polychaetes (bristle worms, Polychaeta: Annelida). At present, the database contains almost 20,000 records on morphological, behavioural and reproductive characteristics of more than 1,000 marine polychaete species, all referenced by literature sources. All data can be freely accessed through the project website in different ways and formats, both human-readable and machine-readable, and have been submitted to the Encyclopedia of Life for archival and integration with trait information from other sources. PMID:24855436

  11. Persistence of asexuality through mixed reproduction in Eucypris virens (Crustacea, Ostracoda).

    PubMed

    Schön, I; Gandolfi, A; Di Masso, E; Rossi, V; Griffiths, H I; Martens, K; Butlin, R K

    2000-02-01

    The ostracod species Eucypris virens exhibits geographical parthenogenesis, with rare sexual populations in southern Europe and widespread asexual populations elsewhere. DNA sequence data from the nuclear ITS1 and mitochondrial COI regions have been used to estimate genetic variabilities and reconstruct phylogenies. The observed divergence was exceptionally high, with intraspecific maxima of 10.3% (ITS1) and 20.9% (COI) among European lineages, levels reported for interspecific comparisons of other taxa. Phylogenetic reconstructions reveal multiple origins of asexual clones from sexual populations. However, we argue that such data can only provide a lower limit on the number of origins of asexual reproduction, and an upper limit on the age of asexual lineages. Congruence between gene trees for different loci can provide support for the inference of long-term apomictic reproduction. Nuclear and mitochondrial data differ in their placement of some asexual clones, possibly indicating that genetic exchange has taken place between sexual and asexual lineages. Such intraspecific hybridization is one route to combine the benefits of both reproductive modes, and it might explain how asexuality managed to persist in E. virens even in long, evolutionary terms.

  12. Genetic Diversity and Population Structure of Rice Pathogen Ustilaginoidea virens in China

    PubMed Central

    Tan, Xinqiu; Yu, Yufei; He, Haiyong; Zhang, Xinyu; Liu, Yongfeng; Wang, Shu; Sun, Wenxian; Cai, Lei; Li, Shaojie

    2013-01-01

    Rice false smut caused by the fungal pathogen Ustilaginoideavirens is becoming a destructive disease throughout major rice-growing countries. Information about its genetic diversity and population structure is essential for rice breeding and efficient control of the disease. This study compared the genome sequences of two U. virens isolates. Three SNP-rich genomic regions were identified as molecular markers that could be used to analyze the genetic diversity and population structure of U. virens in China. A total of 56 multilocus sequence types (haplotypes) were identified out of 162 representative isolates from 15 provinces covering five major rice-growing areas in China. However, the phylogeny, based on sequences at individual SNP-rich regions, strongly conflicted with each other and there were significant genetic differences between different geographical populations. Gene flow between the different geographical populations and genetic differentiation within each geographical population were also detected. In addition, genetic recombination and genetic isolation resulting from geographic separation was also found. PMID:24098811

  13. Osteosarcoma of the maxilla with concurrent osteoma in a southern sea otter (Enhydra lutris nereis)

    USGS Publications Warehouse

    Fernandez, J. Rodriguez-Ramos; Thomas, N.J.; Dubielzig, R.R.; Drees, R.

    2012-01-01

    Southern sea otters (Enhydra lutris nereis) are threatened marine mammals that belong to the family Mustelidae and are native to the coast of Central California. Neoplasia is reported infrequently in seaotters. An adult female free-ranging southern sea otter was found alive at Pebble Beach, Monterey County, California, on January 1st, 1994 and died soon after capture. The carcass was submitted to the US Geological Survey – National Wildlife Health Center for necropsy examination. Grossly, a mass with rubbery texture was firmly attached to the left maxillary region of the skull and the nasopharynx was occluded by soft neoplastic tissue. Post-mortem skull radiographs showed an oval, smoothly marginated mineralized opaque mass centered on the left maxilla, extending from the canine tooth to caudal to the molar and replacing portions of the zygomatic arch and palatine and temporal bones. The majority of the mass protruded laterally from the maxilla and was characterized by central homogeneous mineral opacity. Microscopically, the mass was characterized by fully differentiated lamellar non-osteonal bone that expanded beyond the margins of the adjacent normal osteonal bone. Sections of the nasopharyngeal mass were comprised of moderately pleomorphic cells with bony stroma. Gross, microscopical and radiological findings were compatible with maxillary osteosarcoma with concurrent osteoma.

  14. Osteoarthritis of the temporomandibular joint in southern sea otters (Enhydra lutris nereis).

    PubMed

    Arzi, B; Winer, J N; Kass, P H; Verstraete, F J M

    2013-11-01

    Museum skull specimens (n = 1,008) of southern sea otters (Enhydra lutris nereis) were examined macroscopically according to defined criteria for the presence, severity and characteristics of temporomandibular joint osteoarthritis (TMJ-OA). The specimens were from stranded young adult to adult animals. Overall, 4.1% of the specimens had findings consistent with TMJ-OA. Of these, 61.0% were from females and 39.0% were from males. In addition, 85.4% of the affected specimens were from adults and 14.6% were from young adults. However, there was no significant association between age and sex with the presence or severity of TMJ-OA. Lesion severity was mild in 41.5%, moderate in 19.5% and severe in 39.0% of affected specimens. The most prominent changes were the presence of osteophytes and subchondral bone defects and porosity. The mandibular condylar process and fossa were affected equally. The lengths of the right and left mandibular heads were significantly associated with age (P = 0.002 and P = 0.003, respectively) and sex (P = 0.0009 and P = 0.001, respectively), but not with the presence of TMJ-OA. The significance of this disease in sea otters remains elusive, but this condition may play an important role in survival of these animals.

  15. Exploring gradients of halogens and zinc in the surface and subsurface of Nereis jaws.

    PubMed

    Khan, Rashda K; Stoimenov, Peter K; Mates, Thomas E; Waite, J Herbert; Stucky, Galen D

    2006-09-26

    The outstanding mechanical properties of impact-bearing tissues, such as Nereis jaws, make their morphology and chemical composition a subject of particular interest. The complex structure of the jaw was recently reported to exhibit molecular gradients that were closely correlated with stiffness and hardness.(18) Accordingly, we have explored the spatial distribution and bonding chemistries of Zn and the halogens in the surface structure of the jaws. Using secondary ion mass spectrometry (SIMS) and scanning electron microscopy (SEM), we found that Cl, Br, and I distributions are enhanced in surface layers of the basal protected portion of the jaw but are shifted to greater depths toward the exposed jaw tip. There are thus two complementary halogen gradients in the jaw: one on the surface that decreases from the base to the tip, coupled to an increasing one in the subsurface layers. The outer surface coating appeared to have granular morphology, in contrast to the anisotropic, fibrous core that dominates the subarchitecture. Using X-ray photoelectron spectroscopy (XPS), we discovered that Zn, I, and Br in the jaws have single chemical environments whereas chlorine is present in two distinct modes (Cl-Zn and Cl-C). Given the inverse relationship between surface exposure and halogen abundance in the jaws, it is unlikely that the halogens contribute directly to mechanical properties such as wear and hardness.

  16. Osteoarthritis of the temporomandibular joint in southern sea otters (Enhydra lutris nereis).

    PubMed

    Arzi, B; Winer, J N; Kass, P H; Verstraete, F J M

    2013-11-01

    Museum skull specimens (n = 1,008) of southern sea otters (Enhydra lutris nereis) were examined macroscopically according to defined criteria for the presence, severity and characteristics of temporomandibular joint osteoarthritis (TMJ-OA). The specimens were from stranded young adult to adult animals. Overall, 4.1% of the specimens had findings consistent with TMJ-OA. Of these, 61.0% were from females and 39.0% were from males. In addition, 85.4% of the affected specimens were from adults and 14.6% were from young adults. However, there was no significant association between age and sex with the presence or severity of TMJ-OA. Lesion severity was mild in 41.5%, moderate in 19.5% and severe in 39.0% of affected specimens. The most prominent changes were the presence of osteophytes and subchondral bone defects and porosity. The mandibular condylar process and fossa were affected equally. The lengths of the right and left mandibular heads were significantly associated with age (P = 0.002 and P = 0.003, respectively) and sex (P = 0.0009 and P = 0.001, respectively), but not with the presence of TMJ-OA. The significance of this disease in sea otters remains elusive, but this condition may play an important role in survival of these animals. PMID:23721871

  17. Butyltin residues in southern sea otters (Enhydra lutris nereis) found dead along California coastal waters

    USGS Publications Warehouse

    Kannan, K.; Guruge, K.S.; Thomas, N.J.; Tanabe, S.; Giesy, J.P.

    1998-01-01

    Tributyltin (TBT) and its degradation products, mono- (MBT) and dibutyltin (DBT), were determined in liver, kidney, and brain tissues of adult southern sea otters (Enhydra lutris nereis) found dead along the coast of California during 1992a??1996. Hepatic concentrations of butyltin compounds (BTs = MBT + DBT + TBT) ranged from 40 to 9200 ng/g wet wt, which varied depending on the sampling location and gender. Concentrations of BTs in sea otters were comparable to those reported in stranded bottlenose dolphins from the U.S. Atlantic Coast during 1989a??1994. Greater accumulation of butyltins in sea otters was explained by their bottom-feeding habit and the diet that consists exclusively of invertebrates such as mollusks and gastropods. Livers of female sea otters contained approximately 2-fold greater concentrations of BTs than did those of males. The composition of butyltin compounds in sea otter tissues was predominated by TBT in most cases and suggestive of recent exposure. Large harbors such as Monterey Harbor that handle ships legally painted with TBT-containing antifouling paints continued to experience ecotoxicologically significant butyltin contamination. Sea otters, which were affected by infectious diseases, contained greater concentrations of BTs in their tissues than those that died from trauma and other unknown causes.

  18. UvHOG1 is important for hyphal growth and stress responses in the rice false smut fungus Ustilaginoidea virens.

    PubMed

    Zheng, Dawei; Wang, Yi; Han, Yu; Xu, Jin-Rong; Wang, Chenfang

    2016-01-01

    Rice false smut caused by Ustilaginoidea virens is one of the most important diseases of rice worldwide. Although its genome has been sequenced, to date there is no report on targeted gene deletion in U. virens and no molecular studies on genetic mechanisms regulating the infection processes of this destructive pathogen. In this study, we attempted to generate knockout mutants of the ortholog of yeast HOG1 MAP kinase gene in U. virens. One Uvhog1 deletion mutant was identified after screening over 600 hygromycin-resistant transformants generated by Agrobacterium tumefaciens mediated transformation. The Uvhog1 mutant was reduced in growth rate and conidiation but had increased sensitivities to SDS, Congo red, and hyperosmotic stress. Deletion of UvHOG1 resulted in reduced expression of the stress response-related genes UvATF1 and UvSKN7. In the Uvhog1 mutant, NaCl treatment failed to stimulate the accumulation of sorbitol and glycerol. In addition, the Uvhog1 mutant had reduced toxicity on shoot growth in rice seed germination assays. Overall, as the first report of targeted gene deletion mutant in U. virens, our results showed that UvHOG1 likely has conserved roles in regulating stress responses, hyphal growth, and possibly secondary metabolism. PMID:27095476

  19. Role of the 4-phosphopantetheinyl transferase of Trichoderma virens in secondary metabolism and induction of plant defense responses.

    PubMed

    Velazquez-Robledo, R; Contreras-Cornejo, H A; Macias-Rodriguez, L; Hernandez-Morales, A; Aguirre, J; Casas-Flores, S; Lopez-Bucio, J; Herrera-Estrella, A

    2011-12-01

    Trichoderma virens is a ubiquitous soil fungus successfully used in biological control due to its efficient colonization of plant roots. In fungi, 4-phosphopantetheinyl transferases (PPTases) activate enzymes involved in primary and secondary metabolism. Therefore, we cloned the PPTase gene ppt1 from T. virens and generated PPTase-deficient (?ppt1) and overexpressing strains to investigate the role of this enzyme in biocontrol and induction of plant defense responses. The ?ppt1 mutants were auxotrophic for lysine, produced nonpigmented conidia, and were unable to synthesize nonribosomal peptides. Although spore germination was severely compromised under both low and high iron availability, mycelial growth occurred faster than the wild type, and the mutants were able to efficiently colonize plant roots. The ?ppt1 mutants were unable of inhibiting growth of phytopathogenic fungi in vitro. Arabidopsis thaliana seedlings co-cultivated with wild-type T. virens showed increased expression of pPr1a:uidA and pLox2:uidA markers, which correlated with enhanced accumulation of salicylic acid (SA), jasmonic acid, camalexin, and resistance to Botrytis cinerea. Co-cultivation of A. thaliana seedlings with ?ppt1 mutants compromised the SA and camalexin responses, resulting in decreased protection against the pathogen. Our data reveal an important role of T. virens PPT1 in antibiosis and induction of SA and camalexin-dependent plant defense responses.

  20. 40 CFR 180.1100 - Gliocladium virens isolate GL-21; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Gliocladium virens isolate GL-21; exemption from the requirement of a tolerance. 180.1100 Section 180.1100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From...

  1. 40 CFR 180.1100 - Gliocladium virens isolate GL-21; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Gliocladium virens isolate GL-21; exemption from the requirement of a tolerance. 180.1100 Section 180.1100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From...

  2. UvHOG1 is important for hyphal growth and stress responses in the rice false smut fungus Ustilaginoidea virens

    PubMed Central

    Zheng, Dawei; Wang, Yi; Han, Yu; Xu, Jin-Rong; Wang, Chenfang

    2016-01-01

    Rice false smut caused by Ustilaginoidea virens is one of the most important diseases of rice worldwide. Although its genome has been sequenced, to date there is no report on targeted gene deletion in U. virens and no molecular studies on genetic mechanisms regulating the infection processes of this destructive pathogen. In this study, we attempted to generate knockout mutants of the ortholog of yeast HOG1 MAP kinase gene in U. virens. One Uvhog1 deletion mutant was identified after screening over 600 hygromycin-resistant transformants generated by Agrobacterium tumefaciens mediated transformation. The Uvhog1 mutant was reduced in growth rate and conidiation but had increased sensitivities to SDS, Congo red, and hyperosmotic stress. Deletion of UvHOG1 resulted in reduced expression of the stress response-related genes UvATF1 and UvSKN7. In the Uvhog1 mutant, NaCl treatment failed to stimulate the accumulation of sorbitol and glycerol. In addition, the Uvhog1 mutant had reduced toxicity on shoot growth in rice seed germination assays. Overall, as the first report of targeted gene deletion mutant in U. virens, our results showed that UvHOG1 likely has conserved roles in regulating stress responses, hyphal growth, and possibly secondary metabolism. PMID:27095476

  3. Ustilaginoidea virens infection of rice in Arkansas: Toxicity of false smut galls, their extracts and the Ustiloxin fraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cool, wet conditions in the southern U.S. during the maturing stages of rice in 1998 contributed to outbreaks of false smut caused by Ustilaginoidea virens. Water extracts of false smut galls in Asia have been reported to contain ustiloxin toxins, cyclic peptide antibiotics that interfered with mi...

  4. Ommexecha virens (Thunberg, 1824) and Descampsacris serrulatum (Serville, 1831) (Orthoptera, Ommexechidae): karyotypes, constitutive heterochromatin and nucleolar organizing regions.

    PubMed

    Carvalho, D B; Rocha, M F; Loreto, V; Silva, A E B; Souza, M J

    2011-01-01

    Chromosomes of Ommexecha virens and Descampsacris serrulatum (Ommexechidae) were analyzed through conventional staining, C-banding, base specific fluorochromes, silver nitrate impregnation (AgNO3), and fluorescent in situ hybridization (FISH) with probe for 45S rDNA. The two species presented diploid number 2n= 23,X0 in males and acrocentric autosomes, except the pair one that presented submetacentric morphology. The X chromosome has distinct morphology in the two analyzed species, being a medium acrocentric in Ommexecha virens and large submetacentric in Descampsacris serrulatum. The C-banding revealed pericentromeric blocks of constitutive heterochromatin (CH) in all the chromosomes of Descampsacris serrulatum. For Ommexecha virens it was evidenced that the blocks of CH are preferentially located in the pericentromeric area (however some bivalents presents additional blocks) or in different positions. The staining with CMA3/DA/DAPI showed GC rich CH blocks (CMA3+) in some chromosomes of the two species. The nucleolar organizer regions (NORs) were located in the bivalents L2, S9, S10 of Ommexecha virens and M5, M6, M7, S11 of Descampsacris serrulatum. The FISH for rDNA showed coincident results with the pattern of active NORs revealed by AgNO3. This work presents the first chromosomal data, obtained through differential cytogenetics techniques in Ommexechidae, contributing to a better characterization of karyotypic evolution for this grasshopper family.

  5. Arabidopsis thaliana: A Model Host Plant to Study Plant–Pathogen Interaction Using Rice False Smut Isolates of Ustilaginoidea virens

    PubMed Central

    Andargie, Mebeaselassie; Li, Jianxiong

    2016-01-01

    Rice false smut fungus which is a biotrophic fungal pathogen causes an important rice disease and brings a severe damage where rice is cultivated. We established a new fungal-plant pathosystem where Ustilaginoidea virens was able to interact compatibly with the model plant Arabidopsis thaliana. Disease symptoms were apparent on the leaves of the plants after 6 days of post inoculation in the form of chlorosis. Cytological studies showed that U. virens caused a heavy infestation inside the cells of the chlorotic tissues. Development and colonization of aerial mycelia in association with floral organ, particularly on anther and stigma of the flowers after 3 weeks of post inoculation was evident which finally caused infection on the developing seeds and pod tissues. The fungus adopts a uniquely biotrophic infection strategy in roots and spreads without causing a loss of host cell viability. We have also demonstrated that U. virens isolates infect Arabidopsis and the plant subsequently activates different defense response mechanisms which are witnessed by the expression of pathogenesis-related genes, PR-1, PR-2, PR-5, PDF1.1, and PDF1.2. The established A. thaliana–U. virens pathosystem will now permit various follow-up molecular genetics and gene expression experiments to be performed to identify the defense signals and responses that restrict fungal hyphae colonization in planta and also provide initial evidence for tissue-adapted fungal infection strategies. PMID:26941759

  6. Ommexecha virens (Thunberg, 1824) and Descampsacris serrulatum (Serville, 1831) (Orthoptera, Ommexechidae): karyotypes, constitutive heterochromatin and nucleolar organizing regions

    PubMed Central

    Carvalho, D.B.; Rocha, M.F.; Loreto, V.; Silva, A.E.B.; Souza, M.J.

    2011-01-01

    Abstract Chromosomes of Ommexecha virens and Descampsacris serrulatum (Ommexechidae) were analyzed through conventional staining, C-banding, base specific fluorochromes, silver nitrate impregnation (AgNO3), and fluorescent in situ hybridization (FISH) with probe for 45S rDNA. The two species presented diploid number 2n= 23,X0 in males and acrocentric autosomes, except the pair one that presented submetacentric morphology. The X chromosome has distinct morphology in the two analyzed species, being a medium acrocentric in Ommexecha virens and large submetacentric in Descampsacris serrulatum. The C-banding revealed pericentromeric blocks of constitutive heterochromatin (CH) in all the chromosomes of Descampsacris serrulatum. For Ommexecha virens it was evidenced that the blocks of CH are preferentially located in the pericentromeric area (however some bivalents presents additional blocks) or in different positions. The staining with CMA3/DA/DAPI showed GC rich CH blocks (CMA3+) in some chromosomes of the two species. The nucleolar organizer regions (NORs) were located in the bivalents L2, S9, S10 of Ommexecha virens and M5, M6, M7, S11 of Descampsacris serrulatum. The FISH for rDNA showed coincident results with the pattern of active NORs revealed by AgNO3. This work presents the first chromosomal data, obtained through differential cytogenetics techniques in Ommexechidae, contributing to a better characterization of karyotypic evolution for this grasshopper family. PMID:24260624

  7. Distribution of polychaete assemblage in relation to natural environmental variation and anthropogenic stress

    NASA Astrophysics Data System (ADS)

    Zan, Xiaoxiao; Zhang, Chongliang; Xu, Binduo; Xue, Ying; Ren, Yiping

    2015-08-01

    Polychaete are diverse species of the soft-bottom community, and are often used as indicators in environment monitoring programs. However, the effects of anthropogenic activities and natural environmental variation on polychaete assemblage are rarely addressed. The goals of this study are to identify the effects of natural environmental variation and anthropogenic stress on polychaete assemblage, and to explore the relationship between the polychaete assemblage structure and anthropogenic stress without considering the natural environmental variation. Based on the data collected from the surveys conducted in the tidal flat of Jiaozhou Bay, the relationship between polychaete assemblage structure and environmental variables was determined using multivariate statistical methods including hierarchical cluster analysis, multidimensional scaling (MDS) and canonical correspondence analysis (CCA). The results showed that the polychaete assemblage was dominated by two species, Amphictene japonica and Heteromastus filiformis, and could be divided into two subgroups characterized by high and low species abundance. CCA illustrated that the natural environmental variables including water temperature and the distance from coast had primary effects on the polychaete assemblage structure; while stress of contaminants, such as As and Hg, had the secondary influences; and stress from the aquacultured species, mainly Ruditapes philippinarum, had a limited effect. Colinearity between the natural environmental variables and anthropogenic stress variables caused a critical divergence in the interpretation of CCA results, which highlighted the risk of a lack of information in environment assessment. Glycinde gurjanovae, Sternaspis scutata and Eulalia bilineata may serve as the `contamination indicators', which need to be confirmed in future studies.

  8. Flow variation and substrate type affect dislodgement of the freshwater polychaete, Manayunkia speciosa

    USGS Publications Warehouse

    Malakauskas, David M.; Wilson, Sarah J.; Wilzbach, Margaret A.; Som, Nicholas A.

    2013-01-01

    We quantified microscale flow forces and their ability to entrain the freshwater polychaete, Manayunkia speciosa, the intermediate host for 2 myxozoan parasites (Ceratomyxa shasta and Parvicapsula minibicornis) that cause substantial mortalities in salmonid fishes in the Pacific Northwest. In a laboratory flume, we measured the shear stress associated with 2 mean flow velocities and 3 substrates and quantified associated dislodgement of polychaetes, evaluated survivorship of dislodged polychaetes, and observed behavioral responses of the polychaetes in response to increased flow. We used a generalized linear mixed model to estimate the probability of polychaete dislodgement for treatment combinations of velocity (mean flow velocity  =  55 cm/s with a shear velocity  =  3 cm/s, mean flow velocity  =  140 cm/s with a shear velocity  =  5 cm/s) and substrate type (depositional sediments and analogs of rock faces and the filamentous alga, Cladophora). Few polychaetes were dislodged at shear velocities <3 cm/s on any substrate. Above this level of shear, probability of dislodgement was strongly affected by both substrate type and velocity. After accounting for substrate, odds of dislodgement were 8× greater at the higher flow. After accounting for velocity, probability of dislodgement was greatest from fine sediments, intermediate from rock faces, and negligible from Cladophora. Survivorship of dislodged polychaetes was high. Polychaetes exhibited a variety of behaviors for avoiding increases in flow, including extrusion of mucus, burrowing into sediments, and movement to lower-flow microhabitats. Our findings suggest that polychaete populations probably exhibit high resilience to flow-mediated disturbances.

  9. Effect of different pollutants on ecologically important polychaete worms. Final report

    SciTech Connect

    Reish, D.J.

    1980-06-01

    The procedures for culturing marine polychaetous annelids from egg to egg under laboratory conditions were described. A manual was prepared detailing the procedures used in culturing 12 species of polychaetes. The effects of heavy metals and the water soluble fractions of petroleum hydrocarbons were measured over 96 hours, 28 days, and with some of the toxicants, over a complete reproductive cycle for some of these species of polychaetes. Mercury and copper were the most toxic of the six metals tested and cadmium was the least toxic. The 28-day LC50 was less than the 96-hour value in most experiments.

  10. Diet of worms emended: an update of polychaete feeding guilds.

    PubMed

    Jumars, Peter A; Dorgan, Kelly M; Lindsay, Sara M

    2015-01-01

    Polychaetes are common in most marine habitats and dominate many infaunal communities. Functional guild classification based on taxonomic identity and morphology has linked community structure to ecological function. The functional guilds now include osmotrophic siboglinids as well as sipunculans, echiurans, and myzostomes, which molecular genetic analyses have placed within Annelida. Advances in understanding of encounter mechanisms explicitly relate motility to feeding mode. New analyses of burrowing mechanics explain the prevalence of bilateral symmetry and blur the boundary between surface and subsurface feeding. The dichotomy between microphagous deposit and suspension feeders and macrophagous carnivores, herbivores, and omnivores is further supported by divergent digestive strategies. Deposit feeding appears to be limited largely to worms longer than 1 cm, with juveniles and small worms in general restricted to ingesting highly digestible organic material and larger, rich food items, blurring the macrophage-microphage dichotomy that applies well to larger worms. PMID:25251269

  11. Diet of Worms Emended: An Update of Polychaete Feeding Guilds

    NASA Astrophysics Data System (ADS)

    Jumars, Peter A.; Dorgan, Kelly M.; Lindsay, Sara M.

    2015-01-01

    Polychaetes are common in most marine habitats and dominate many infaunal communities. Functional guild classification based on taxonomic identity and morphology has linked community structure to ecological function. The functional guilds now include osmotrophic siboglinids as well as sipunculans, echiurans, and myzostomes, which molecular genetic analyses have placed within Annelida. Advances in understanding of encounter mechanisms explicitly relate motility to feeding mode. New analyses of burrowing mechanics explain the prevalence of bilateral symmetry and blur the boundary between surface and subsurface feeding. The dichotomy between microphagous deposit and suspension feeders and macrophagous carnivores, herbivores, and omnivores is further supported by divergent digestive strategies. Deposit feeding appears to be limited largely to worms longer than 1 cm, with juveniles and small worms in general restricted to ingesting highly digestible organic material and larger, rich food items, blurring the macrophage-microphage dichotomy that applies well to larger worms.

  12. Homeogenetic inductive mechanism of segmentation in polychaete tail regeneration.

    PubMed

    Niwa, Nao; Akimoto-Kato, Ai; Sakuma, Masashi; Kuraku, Shigehiro; Hayashi, Shigeo

    2013-09-15

    Segmentation is a body-patterning strategy in which new segments are specified from a segment-addition zone containing uncommitted cells. However, the cell-recruitment process is poorly understood. Here we investigated in detail the segmentation in a polychaete annelid, Perinereis nuntia (Lophotrochozoa), in which new segments emerge at the boundary between the posterior end of the segmented region and the terminal pygidium. Cells at this border synchronously remodel their chromatin, enter the cell cycle, and undergo oriented cell division, before being added to new segments. wingless is expressed at the posterior edge of the pre-existing segment, abutted by hedgehog in the first row of the new segment. Overstimulation of Wingless signaling caused excess cells to enter the cell cycle, prolonging segmentation and widening the new segment. Thus, segment addition may occur by a homeogenetic mechanism, in which Wingless expressed in the differentiated segment coordinates the stepwise recruitment of undifferentiated cells from the segment/pygidium boundary. PMID:23608458

  13. Diet of worms emended: an update of polychaete feeding guilds.

    PubMed

    Jumars, Peter A; Dorgan, Kelly M; Lindsay, Sara M

    2015-01-01

    Polychaetes are common in most marine habitats and dominate many infaunal communities. Functional guild classification based on taxonomic identity and morphology has linked community structure to ecological function. The functional guilds now include osmotrophic siboglinids as well as sipunculans, echiurans, and myzostomes, which molecular genetic analyses have placed within Annelida. Advances in understanding of encounter mechanisms explicitly relate motility to feeding mode. New analyses of burrowing mechanics explain the prevalence of bilateral symmetry and blur the boundary between surface and subsurface feeding. The dichotomy between microphagous deposit and suspension feeders and macrophagous carnivores, herbivores, and omnivores is further supported by divergent digestive strategies. Deposit feeding appears to be limited largely to worms longer than 1 cm, with juveniles and small worms in general restricted to ingesting highly digestible organic material and larger, rich food items, blurring the macrophage-microphage dichotomy that applies well to larger worms.

  14. Defense function of pigment granules in the ciliate Blepharisma japonicum against two predatory protists, Amoeba proteus (Rhizopodea) and Climacostomum virens (Ciliata).

    PubMed

    Terazima, Masayo Noda; Harumoto, Terue

    2004-08-01

    The defense function of pigment granules in the red ciliate Blepharisma japonicum against two predatory protists, Amoeba proteus and Climacostomum virens, was investigated by (1) comparing normally-pigmented and albino mutant cells of B. japonicum as the prey of these predators and (2) comparing resistance of the predators to blepharismin, the toxic pigment contained in the pigment granules of B. japonicum. Normally pigmented cells which contained more blepharismin than albino cells were less vulnerable to A. proteus than albino cells, but not to C. virens. C. virens was more resistant than A. proteus to the lethal effect of blepharismin. The results indicate that pigment granules of B. japonicum function as defense organelles against A. proteus but not against C. virens and suggest that successful defense against a predator depends on the susceptibility of the predator to blepharismin.

  15. Ontogenetic Scaling of Theoretical Bite Force in Southern Sea Otters (Enhydra lutris nereis).

    PubMed

    Law, Chris J; Young, Colleen; Mehta, Rita S

    2016-01-01

    Sexual dimorphism attributed to niche divergence is often linked to differentiation between the sexes in both dietary resources and characters related to feeding and resource procurement. Although recent studies have indicated that southern sea otters (Enhydra lutris nereis) exhibit differences in dietary preferences as well as sexual dimorphism in skull size and shape, whether these intersexual differences translate to differentiation in feeding performances between the sexes remains to be investigated. To test the hypothesis that scaling patterns of bite force, a metric of feeding performance, differ between the sexes, we calculated theoretical bite forces for 55 naturally deceased male and female southern sea otters spanning the size ranges encountered over ontogeny. We then used standardized major axis regressions to simultaneously determine the scaling patterns of theoretical bite forces and skull components across ontogeny and assess whether these scaling patterns differed between the sexes. We found that positive allometric increases in theoretical bite force resulted from positive allometric increases in physiological cross-sectional area for the major jaw adductor muscle and mechanical advantage. Closer examination revealed that allometric increases in temporalis muscle mass and relative allometric decreases in out-lever lengths are driving these patterns. In our analysis of sexual dimorphism, we found that scaling patterns of theoretical bite force and morphological traits do not differ between the sexes. However, adult sea otters differed in their absolute bite forces, revealing that adult males exhibited greater bite forces as a result of their larger sizes. We found intersexual differences in biting ability that provide some support for the niche divergence hypothesis. Continued work in this field may link intersexual differences in feeding functional morphology with foraging ecology to show how niche divergence has the potential to reinforce sexual

  16. Ontogenetic Scaling of Theoretical Bite Force in Southern Sea Otters (Enhydra lutris nereis).

    PubMed

    Law, Chris J; Young, Colleen; Mehta, Rita S

    2016-01-01

    Sexual dimorphism attributed to niche divergence is often linked to differentiation between the sexes in both dietary resources and characters related to feeding and resource procurement. Although recent studies have indicated that southern sea otters (Enhydra lutris nereis) exhibit differences in dietary preferences as well as sexual dimorphism in skull size and shape, whether these intersexual differences translate to differentiation in feeding performances between the sexes remains to be investigated. To test the hypothesis that scaling patterns of bite force, a metric of feeding performance, differ between the sexes, we calculated theoretical bite forces for 55 naturally deceased male and female southern sea otters spanning the size ranges encountered over ontogeny. We then used standardized major axis regressions to simultaneously determine the scaling patterns of theoretical bite forces and skull components across ontogeny and assess whether these scaling patterns differed between the sexes. We found that positive allometric increases in theoretical bite force resulted from positive allometric increases in physiological cross-sectional area for the major jaw adductor muscle and mechanical advantage. Closer examination revealed that allometric increases in temporalis muscle mass and relative allometric decreases in out-lever lengths are driving these patterns. In our analysis of sexual dimorphism, we found that scaling patterns of theoretical bite force and morphological traits do not differ between the sexes. However, adult sea otters differed in their absolute bite forces, revealing that adult males exhibited greater bite forces as a result of their larger sizes. We found intersexual differences in biting ability that provide some support for the niche divergence hypothesis. Continued work in this field may link intersexual differences in feeding functional morphology with foraging ecology to show how niche divergence has the potential to reinforce sexual

  17. Effects of chronic avian malaria (Plasmodium relictum) infection on reproductive success of Hawaii Amakihi (Hemignathus virens)

    USGS Publications Warehouse

    Kilpatrick, A.M.; Lapointe, D.A.; Atkinson, C.T.; Woodworth, B.L.; Lease, J.K.; Reiter, M.E.; Gross, K.

    2006-01-01

    We studied the effects of chronic avian malaria (Plasmodium relictum) infections on the reproductive success of a native Hawaiian honeycreeper, Hawaii Amakihi (Hemignathus virens). Chronic malaria infections in male and female parents did not significantly reduce reproductive success as measured by clutch size, hatching success, fledging mass, number of nestlings fledged, nesting success (daily survival rate), and minimum fledgling survival. In fact, nesting success of pairs with chronically infected males was significantly higher than those with uninfected males (76% vs. 38%), and offspring that had at least one parent that had survived the acute phase of malaria infection had a significantly greater chance of being resighted the following year (25% vs. 10%). The reproduction and survival of infected birds were sufficient for a per-capita population growth rate >1, which suggests that chronically infected Hawaii Amakihi could support a growing population. ?? The American Ornithologists' Union, 2006.

  18. A Metabolomic Approach To Detect Effects of Salmon Farming on Wild Saithe (Pollachius virens) Populations.

    PubMed

    Maruhenda Egea, Frutos C; Toledo-Guedes, Kilian; Sanchez-Jerez, Pablo; Ibanco-Cañete, Ricardo; Uglem, Ingebrit; Saether, Bjørn-Steinar

    2015-12-16

    A metabolomics approach was used to analyze effects of salmon farming on wild saithe (Pollachius virens) populations. Saithe fish were captured at two salmon farms and at two control locations around the island of Hitra, Norway. Changes in diet seem to drive changes in metabolic status of fishes. The liver and muscle tissues, from the fishes captured around the farm, showed higher levels of lactate and certain amino acids (glutamine, glutamate, and alanine) and lower levels of glucose and choline than the fishes captured in the control locations, far from the farm locations. The higher levels of lactate and amino acids could be related to the facility of obtaining food around the farm and the deficit in choline to the deficit of this nutrient in the salmon feed. At each location the fish were captured with either benthic gill nets and automatic jigging machines, and this feature showed also variations in different metabolites. PMID:26600204

  19. A Metabolomic Approach To Detect Effects of Salmon Farming on Wild Saithe (Pollachius virens) Populations.

    PubMed

    Maruhenda Egea, Frutos C; Toledo-Guedes, Kilian; Sanchez-Jerez, Pablo; Ibanco-Cañete, Ricardo; Uglem, Ingebrit; Saether, Bjørn-Steinar

    2015-12-16

    A metabolomics approach was used to analyze effects of salmon farming on wild saithe (Pollachius virens) populations. Saithe fish were captured at two salmon farms and at two control locations around the island of Hitra, Norway. Changes in diet seem to drive changes in metabolic status of fishes. The liver and muscle tissues, from the fishes captured around the farm, showed higher levels of lactate and certain amino acids (glutamine, glutamate, and alanine) and lower levels of glucose and choline than the fishes captured in the control locations, far from the farm locations. The higher levels of lactate and amino acids could be related to the facility of obtaining food around the farm and the deficit in choline to the deficit of this nutrient in the salmon feed. At each location the fish were captured with either benthic gill nets and automatic jigging machines, and this feature showed also variations in different metabolites.

  20. Polychaete assemblage as surrogate for prey availability in assessing southeastern Bering Sea flatfish habitat

    NASA Astrophysics Data System (ADS)

    Yeung, Cynthia; Yang, Mei-Sun; Jewett, Stephen C.; Naidu, A. S.

    2013-02-01

    The flatfish yellowfin sole (Limanda aspera), northern rock sole (Lepidopsetta polyxystra), and Alaska plaice (Pleuronectes quadrituberculatus) in the southeastern Bering Sea prey mainly on infauna. Spatial correspondence between their stomach contents and infauna assemblages across habitat types was examined to identify indices of prey availability for flatfish habitat characterization and quality assessment. Benthic samples and flatfish stomachs were collected in 2009 near the Alaska Peninsula in the southeastern Bering Sea. Polychaetes and bivalves were the most dominant infauna groups, each comprising 35-60% by weight in each infauna sample. These two were also the only prey groups that frequently averaged > 50% of stomach content by weight. Bivalves dominated the infauna biomass on the relatively sandy inner shelf (0-50 m depth). The muddier middle shelf (50-100 m) had the highest infauna biomass, which was dominated by polychaetes. Diet compositions of the flatfish varied spatially in correspondence with the infauna assemblage. Polychaetes were prevalent in all flatfish diets on the middle shelf, even yellowfin sole whose typical primary prey are amphipods and bivalves. Polychaete-rich habitats are potentially prime for flatfish as polychaetes are readily utilized where available and generally have high nutritional value. Flatfish did not select for specific polychaete taxa, so an index of habitat quality could be based on the biomass of aggregate polychaetes or on dominant polychaete families of the region. Under normal environmental conditions, the three flatfish have slightly-offset spatial distributions, enabling each to utilize different infauna assemblages across the shelf. However, during cold phases in the Bering Sea ecosystem, as when this study was conducted, a cold pool of < 2 °C bottom water from the spring ice melt extends over the middle shelf in summer. This physiological barrier displaces all three flatfish to the inner shelf, intensifying

  1. De novo sequencing and transcriptome analysis of Ustilaginoidea virens by using Illumina paired-end sequencing and development of simple sequence repeat markers.

    PubMed

    Yu, Mina; Yu, Junjie; Gu, Chenhao; Nie, Yafeng; Chen, Zhiyi; Yin, Xiaole; Liu, Yongfeng

    2014-09-01

    Ustilaginoidea virens is the causal agent of rice false smut, which is a rice disease of increasing importance worldwide that has caused with the quantitative and qualitative rice losses. However, research on the pathogenic mechanism of U. virens is limited. In this study, we reported a de novo assembling, annotation, and characterization of the transcriptome and developed simple sequence repeat (SSR) markers of U. virens. U. virens transcripts of the mycelia and conidia mixture were sequenced using Illumina RNA-seq technology. A total of 52,554,142 clean reads were assembled into 36,496 transcripts representing 18,534 unigenes. Assembled unigenes were annotated through sequence comparison with known protein databases, and 48.48% of the unigenes were without hits in any of these databases. Clusters of orthologous groups for eukaryotic complete genome analysis identified the largest set of genes associated with posttranslational modification, protein turnover and chaperones. Kyoto Encyclopedia of Genes and Genomes pathway analyses identified the number of genes associated with mitogen-activated protein kinase and calcium-calcineurin pathways. The study also identified several putative pathogenicity determinants and candidate effectors in U. virens by using the pathogen-host interaction database. In addition, bioinformatics analysis revealed the presence of 12,298 SSR markers. This study provides a better understanding of the biology of U. virens and is an excellent resource for candidate genes required for pathogenesis discovery.

  2. Impacts of the 2011 tsunami on the subtidal polychaete assemblage and the following recolonization in Onagawa Bay, northeastern Japan.

    PubMed

    Abe, Hirokazu; Kobayashi, Genki; Sato-Okoshi, Waka

    2015-12-01

    The ecological impacts of the 2011 Great East Japan Earthquake and tsunami and the following recolonization of the subtidal benthic polychaete community were examined by monthly pre- and post-quake field surveys that were conducted in Onagawa Bay from 2007 to 2013. Before the tsunami, the species composition in this benthic community was constant and was dominated by cirratulid and magelonid polychaetes. The density and biomass of benthic polychaetes drastically decreased after the tsunami, and the polychaete community fluctuated during the 2 years after the natural disaster. Spionid and capitellid polychaetes were dominant at this period. In June 2013, the community entered a new constant stage dominated by maldanids, which is different from the pre-quake community. Ecological impacts due to chemical pollution were suggested in addition to the tsunami disturbance. These overlapping effects and physical, chemical and biological factors affected the recovery and recolonization of the polychaete community after the natural disaster.

  3. Impacts of the 2011 tsunami on the subtidal polychaete assemblage and the following recolonization in Onagawa Bay, northeastern Japan.

    PubMed

    Abe, Hirokazu; Kobayashi, Genki; Sato-Okoshi, Waka

    2015-12-01

    The ecological impacts of the 2011 Great East Japan Earthquake and tsunami and the following recolonization of the subtidal benthic polychaete community were examined by monthly pre- and post-quake field surveys that were conducted in Onagawa Bay from 2007 to 2013. Before the tsunami, the species composition in this benthic community was constant and was dominated by cirratulid and magelonid polychaetes. The density and biomass of benthic polychaetes drastically decreased after the tsunami, and the polychaete community fluctuated during the 2 years after the natural disaster. Spionid and capitellid polychaetes were dominant at this period. In June 2013, the community entered a new constant stage dominated by maldanids, which is different from the pre-quake community. Ecological impacts due to chemical pollution were suggested in addition to the tsunami disturbance. These overlapping effects and physical, chemical and biological factors affected the recovery and recolonization of the polychaete community after the natural disaster. PMID:26454517

  4. A paralog of the proteinaceous elicitor SM1 is involved in colonization of maize roots by Trichoderma virens.

    PubMed

    Crutcher, Frankie K; Moran-Diez, Maria E; Ding, Shengli; Liu, Jinggao; Horwitz, Benjamin A; Mukherjee, Prasun K; Kenerley, Charles M

    2015-06-01

    The biocontrol agent, Trichoderma virens, has the ability to protect plants from pathogens by eliciting plant defense responses, involvement in mycoparasitism, or secreting antagonistic secondary metabolites. SM1, an elicitor of induced systemic resistance (ISR), was found to have three paralogs within the T. virens genome. The paralog sm2 is highly expressed in the presence of plant roots. Gene deletion mutants of sm2 were generated and the mutants were found to overproduce SM1. The ability to elicit ISR in maize against Colletotrichum graminicola was not compromised for the mutants compared to that of wild type isolate. However, the deletion strains had a significantly lowered ability to colonize maize roots. This appears to be the first report on the involvement of an effector-like protein in colonization of roots by Trichoderma.

  5. Plant-derived sucrose is a key element in the symbiotic association between Trichoderma virens and maize plants.

    PubMed

    Vargas, Walter A; Mandawe, John C; Kenerley, Charles M

    2009-10-01

    Fungal species belonging to the genus Trichoderma colonize the rhizosphere of many plants, resulting in beneficial effects such as increased resistance to pathogens and greater yield and productivity. However, the molecular mechanisms that govern the recognition and association between Trichoderma and their hosts are still largely unknown. In this report, we demonstrate that plant-derived sucrose (Suc) is an important resource provided to Trichoderma cells and is also associated with the control of root colonization. We describe the identification and characterization of an intracellular invertase from Trichoderma virens (TvInv) important for the mechanisms that control the symbiotic association and fungal growth in the presence of Suc. Gene expression studies revealed that the hydrolysis of plant-derived Suc in T. virens is necessary for the up-regulation of Sm1, the Trichoderma-secreted elicitor that systemically activates the defense mechanisms in leaves. We determined that as a result of colonization of maize (Zea mays) roots by T. virens, photosynthetic rate increases in leaves and the functional expression of tvinv is crucial for such effect. In agreement, the steady-state levels of mRNA for Rubisco small subunit and the oxygen-evolving enhancer 3-1 were increased in leaves of plants colonized by wild-type T. virens. We conclude that during the symbiosis, the sucrolytic activity in the fungal cells affects the sink activity of roots, directing carbon partitioning toward roots and increasing the rate of photosynthesis in leaves. A discussion of the role of Suc in controlling the fungal proliferation on roots and its pivotal role in the coordination of plant-microbe associations is provided.

  6. Isolation and cultivation of xylanolytic and cellulolytic Sarocladium kiliense and Trichoderma virens from the gut of the termite Reticulitermes santonensis.

    PubMed

    Tarayre, Cédric; Bauwens, Julien; Brasseur, Catherine; Mattéotti, Christel; Millet, Catherine; Guiot, Pierre Alexandre; Destain, Jacqueline; Vandenbol, Micheline; Portetelle, Daniel; De Pauw, Edwin; Haubruge, Eric; Francis, Frédéric; Thonart, Philippe

    2015-03-01

    The purpose of this work was the isolation and cultivation of cellulolytic and xylanolytic microorganisms extracted from the gut of the lower termite Reticulitermes santonensis. Microcrystalline cellulose (with and without lignin) and beech wood xylan were used as diets instead of poplar wood in order to select cellulose and hemicellulose-degrading fungi. The strain Sarocladium kiliense (Acremonium kiliense) CTGxxyl was isolated from the termites fed on xylan, while the strain Trichoderma virens CTGxAviL was isolated from the termites fed on cellulose (with and without lignin). Both molds were cultivated in liquid media containing different substrates: agro-residues or purified polymers. S. kiliense produced maximal β-glucosidase, endo-1,4-β-D-glucanase, exo-1,4-β-D-glucanase and endo-1,4-β-D-xylanase activities of 0.103, 3.99, 0.53, and 40.8 IU/ml, respectively. T. virens produced maximal β-xylosidase, endo-1,4-β-D-glucanase, exo-1,4-β-D-glucanase, and endo-1,4-β-D-xylanase activities of 0.38, 1.48, 0.69, and 426 IU/ml. The cellulase and the xylanase of S. kiliense, less common than T. virens, were further investigated. The optimal activity of the xylanase was observed at pH 9-10 at 60 °C. The cellulase showed its maximal activity at pH 10, 70 °C. Zymography identified different xylanases produced by both molds, and some fragment sizes were highlighted: 35, 100, and 170 kDa for S. kiliense and 20, 40, 80, and 170 kDa for T. virens. In both cases, endo-1,4-β-D-xylanase activities were confirmed through mass spectrometry.

  7. Detection and sequence analysis of two novel co-infecting double-strand RNA mycoviruses in Ustilaginoidea virens.

    PubMed

    Zhong, Jie; Lei, Xiang Hua; Zhu, Jun Zi; Song, Ge; Zhang, Ya Dong; Chen, Yi; Gao, Bi Da

    2014-11-01

    Four novel double-stranded RNA molecules, named dsRNA 1 (5124 bp), dsRNA 2(1711 bp), dsRNA 3 (1423 bp) and dsRNA 4 (855 bp), were detected in strain HNHS-1 of Ustilaginoidea virens, the causal agent of rice false smut disease. Sequence analysis showed that the dsRNA1 contains two overlapping open reading frames (ORF) potentially encoding proteins with modest levels of sequence similarity to the coat protein (CP) and putative RNA-dependent RNA polymerase (RdRp), respectively, of viruses of the family Totiviridae. The deduced gene product of the ORF encoded by dsRNA2 is homologous to putative RdRp of viruses in the family Partitiviridae; the ORF encoded by dsRNA3 shares some similarity to a hypothetical protein with unknown function. It is noteworthy that the dsRNA4 lacked integrated ORFs. Isomeric viral particles of about 40 nm in diameter were observed by transmission electron microscopy in a mycelium tissue preparation of strain HNHS-1-R1, a single-spore subculture of strain HNHS-1 containing only the dsRNA1 segment. Phylogenetic analysis and examination of the organization of the two putative RdRp sequences both indicated that there are at least two novel virus species present in strain HNHS-1. We named the two novel viruses Ustilaginoidea virens RNA virus 2 and Ustilaginoidea virens partitivirus 4, respectively.

  8. Using stable isotopes to investigate individual diet specialization in California sea otters (Enhydra lutris nereis)

    USGS Publications Warehouse

    Newsome, S.D.; Tinker, M.T.; Monson, D.H.; Oftedal, O.T.; Ralls, K.; Staedler, M.M.; Fogel, M.L.; Estes, J.A.

    2009-01-01

    Differences in diet composition among conspecifics (dietary specialization) have been documented across a broad range of taxonomic groups and habitats, and such variation at the individual level is increasingly recognized as an important component of diversity in trophic interactions. Accurate identification of individual dietary specialization, however, requires longitudinal dietary records that are labor-intensive and cost-prohibitive to obtain for many species. Here we explore the use of stable isotopes (??13C and ??15N) as a promising technique for detecting and quantifying patterns of individual dietary specialization. Southern sea otters (Enhydra lutris nereis) offer a unique opportunity for testing this approach because (1) they consume a wide variety of prey that span multiple trophic levels, habitats, and ecologically defined functional groups: and (2) individual diet specialization can be validated with existing observational data. We analyzed the isotopic composition of sea otter vibrissae (n = 31) in order to characterize inter- and intra-individual variation in sea otter diets at Monterey Bay, California, USA. At the population level, sea otters showed substantial variation in both ??13C and ??15N values, occupying nearly all of the "isotopic space" created by the diversity of isotopic signatures of potential prey taxa. Most of the variation in sea otter vibrissae was accounted for by differences between individuals, with much less contributed by within-individual variation. A majority of sea otters (???80%) showed relatively little temporal variability in isotopic composition, suggesting that the proportional composition of most individuals' diets is relatively constant over time; a few individuals (???20%) exhibited a high degree of intra-vibrissa isotopic variability, suggesting seasonal shifts in diet composition. These results and our interpretation of them were supported by long-term observational data on the diets of radio-tagged sea otters from

  9. Using stable isotopes to investigate individual diet specialization in California sea otters (Enhydra lutris nereis).

    PubMed

    Newsome, Seth D; Tinker, M Tim; Monson, Daniel H; Oftedal, Olav T; Ralls, Katherine; Staedler, Michelle M; Fogel, Marilyn L; Estes, James A

    2009-04-01

    Differences in diet composition among conspecifics (dietary specialization) have been documented across a broad range of taxonomic groups and habitats, and such variation at the individual level is increasingly recognized as an important component of diversity in trophic interactions. Accurate identification of individual dietary specialization, however, requires longitudinal dietary records that are labor-intensive and cost-prohibitive to obtain for many species. Here we explore the use of stable isotopes (delta13C and delta15N) as a promising technique for detecting and quantifying patterns of individual dietary specialization. Southern sea otters (Enhydra lutris nereis) offer a unique opportunity for testing this approach because (1) they consume a wide variety of prey that span multiple trophic levels, habitats, and ecologically defined functional groups; and (2) individual diet specialization can be validated with existing observational data. We analyzed the isotopic composition of sea otter vibrissae (n = 31) in order to characterize inter- and intra-individual variation in sea otter diets at Monterey Bay, California, USA. At the population level, sea otters showed substantial variation in both delta13C and delta15N values, occupying nearly all of the "isotopic space" created by the diversity of isotopic signatures of potential prey taxa. Most of the variation in sea otter vibrissae was accounted for by differences between individuals, with much less contributed by within-individual variation. A majority of sea otters (approximately 80%) showed relatively little temporal variability in isotopic composition, suggesting that the proportional composition of most individuals' diets is relatively constant over time; a few individuals (approximately 20%) exhibited a high degree of intra-vibrissa isotopic variability, suggesting seasonal shifts in diet composition. These results and our interpretation of them were supported by long-term observational data on the

  10. Trichoderma virens, a plant beneficial fungus, enhances biomass production and promotes lateral root growth through an auxin-dependent mechanism in Arabidopsis.

    PubMed

    Contreras-Cornejo, Hexon Angel; Macías-Rodríguez, Lourdes; Cortés-Penagos, Carlos; López-Bucio, José

    2009-03-01

    Trichoderma species belong to a class of free-living fungi beneficial to plants that are common in the rhizosphere. We investigated the role of auxin in regulating the growth and development of Arabidopsis (Arabidopsis thaliana) seedlings in response to inoculation with Trichoderma virens and Trichoderma atroviride by developing a plant-fungus interaction system. Wild-type Arabidopsis seedlings inoculated with either T. virens or T. atroviride showed characteristic auxin-related phenotypes, including increased biomass production and stimulated lateral root development. Mutations in genes involved in auxin transport or signaling, AUX1, BIG, EIR1, and AXR1, were found to reduce the growth-promoting and root developmental effects of T. virens inoculation. When grown under axenic conditions, T. virens produced the auxin-related compounds indole-3-acetic acid, indole-3-acetaldehyde, and indole-3-ethanol. A comparative analysis of all three indolic compounds provided detailed information about the structure-activity relationship based on their efficacy at modulating root system architecture, activation of auxin-regulated gene expression, and rescue of the root hair-defective phenotype of the rhd6 auxin response Arabidopsis mutant. Our results highlight the important role of auxin signaling for plant growth promotion by T. virens.

  11. Chemical composition and antifungal activity of the essential oil of Origanum virens on Candida species.

    PubMed

    Salgueiro, L R; Cavaleiro, C; Pinto, E; Pina-Vaz, C; Rodrigues, A G; Palmeira, A; Tavares, C; Costa-de-Oliveira, S; Gonçalves, M J; Martinez-de-Oliveira, J

    2003-09-01

    The composition and the antifungal activity of the essential oil of Origanum virens on Candida species were studied. The essential oil was obtained from the aerial parts of the plant by hydrodistillation and analyzed by GC and GC-MS. The oil was characterized by its high content of carvacrol (68.1 %) and its biogenetic precursors, gamma-terpinene (9.9 %) and p-cymene (4.5 %). The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity against Candida strains (7 clinical isolates and 3 ATCC type strains). The inhibition of germ tube formation and flow cytometry, using the fluorescent probe propidium iodide (PI), were used to evaluate their mechanisms of action. MIC and MLC values were similar for most tested strains, ranging from 0.16 to 0.32 microL/mL. Concentrations lower than MIC values strongly prevent germ tube formation. The fungicidal effect is primarily due to an extensive lesion of the membrane. PMID:14598221

  12. Isolation and characterization of a novel lectin from the mushroom Armillaria luteo-virens

    SciTech Connect

    Feng, K.; Liu, Q.H.; Ng, T.B.; Liu, H.Z.; Li, J.Q.; Chen, G.; Sheng, H.Y.; Xie, Z.L.; Wang, H.X. . E-mail: hxwang@cau.edu.cn

    2006-07-14

    From the dried fruiting bodies of the mushroom Armillaria luteo-virens, a dimeric lectin with a molecular mass of 29.4 kDa has been isolated. The purification procedure involved (NH{sub 4}){sub 2}SO{sub 4} precipitation, ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. The hemagglutinating activity of the lectin could not be inhibited by simple sugars but was inhibited by the polysaccharide inulin. The activity was stable up to 70 {sup o}C but was acid- and alkali-labile. Salts including FeCl{sub 3}, AlCl{sub 3}, and ZnCl{sub 2} inhibited the activity whereas MgCl{sub 2}, MnCl{sub 2}, and CaCl{sub 2} did not. The lectin stimulated mitogenic response of mouse splenocytes with the maximal response achieved by 1 {mu}M lectin. Proliferation of tumor cells including MBL2 cells, HeLa cells, and L1210 cells was inhibited by the lectin with an IC{sub 5} of 2.5, 5, and 10 {mu}M, respectively. However, proliferation of HepG2 cells was not affected. The novel aspects of the isolated lectin include a novel N-terminal sequence, fair thermostability, acid stability, and alkali stability, together with potent mitogenic activity toward spleen cells and antiproliferative activity toward tumor cells.

  13. Purification and characterization of a ribonuclease from the wild edible mushroom Armillaria luteo-virens.

    PubMed

    Xu, Li-Jing; Chen, Qing-Jun; Wang, He-Xiang; Zhang, Guo-Qing

    2013-06-01

    A 15 kDa ribonuclease (RNase) was purified from dried fruiting bodies of the wild edible mushroom Armillaria luteo-virens. The simple 4-step purification protocol involved ion-exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion-exchange chromatography on SP-Sepharose and a final gel filtration by FPLC on Superdex-75. The RNase was unadsorbed on Affi-gel blue gel, but adsorbed on DEAE-cellulose and SP-Sepharose. The N-terminal amino acid sequence of purified RNase was AGVQYKLTILLV, which showed low sequence homology to those of previously reported RNases. The optimal pH and temperature of the enzyme were very close to 4.0 and 70 degrees C, respectively. The enzyme showed considerably high ribonucleolytic activity and broad specificity towards polyhomoribonucleotides, with a specificity of poly(U) > poly(C) > poly (G) > poly(A). The ribonucleolytic activities towards poly(U), poly(C), poly(G) and poly(A) were 279.5, 184.1, 69.9 and 52.3 U/mg, respectively.

  14. Regulation of morphogenesis and biocontrol properties in Trichoderma virens by a VELVET protein, Vel1.

    PubMed

    Mukherjee, Prasun K; Kenerley, Charles M

    2010-04-01

    Mycoparasitic strains of Trichoderma are applied as commercial biofungicides for control of soilborne plant pathogens. Although the majority of commercial biofungicides are Trichoderma based, chemical pesticides, which are ecological and environmental hazards, still dominate the market. This is because biofungicides are not as effective or consistent as chemical fungicides. Efforts to improve these products have been limited by a lack of understanding of the genetic regulation of biocontrol activities. In this study, using gene knockout and complementation, we identified the VELVET protein Vel1 as a key regulator of biocontrol, as well as morphogenetic traits, in Trichoderma virens, a commercial biocontrol agent. Mutants with mutations in vel1 were defective in secondary metabolism (antibiosis), mycoparasitism, and biocontrol efficacy. In nutrient-rich media they also lacked two types of spores important for survival and development of formulation products: conidia (on agar) and chlamydospores (in liquid shake cultures). These findings provide an opportunity for genetic enhancement of biocontrol and industrial strains of Trichoderma, since Vel1 is very highly conserved across three Trichoderma species.

  15. Characteristics of freeze-dried fish protein isolated from saithe (Pollachius virens).

    PubMed

    Shaviklo, Gholam Reza; Thorkelsson, Gudjon; Arason, Sigurjon; Sveinsdottir, Kolbrun

    2012-06-01

    Fish proteins isolated from by-products or low commercial/underutilized species using pH-shift process is a new source of proteins that may be used as wet or dried ingredients to develop value-added convenience foods. This paper reports the effects of freeze-drying on characteristics of fish protein isolates (FPI) from saithe (Pollachius virens) with or without lyoprotectants. Freeze-dried saithe mince from the same lot and without additives was used as a control. The resulting fish protein powders contained 71-93% protein, 1.5-3% moisture, 0-21% carbohydrate and 0.5-2% fat. Lipid oxidation (assessed by TBARS) of FPI powder groups was higher than that of fish mince powder. The results revealed that oxidation started during the pH-shift process and was increased by freeze-drying. Functional properties and sensory attributes were influenced by the advanced oxidation. However, the mince powder was less oxidized and had higher functional properties such as water binding capacity, gel forming ability, emulsification, foaming properties and colour and lower sensory scores for rancid odour and flavour than the FPI powders. Further studies on how to prevent oxidation of fish flesh during pH-shift and drying processes are recommended. PMID:23729850

  16. Infection of Ustilaginoidea virens intercepts rice seed formation but activates grain‐filling‐related genes

    PubMed Central

    Fan, Jing; Guo, Xiao‐Yi; Li, Liang; Huang, Fu; Sun, Wen‐Xian; Li, Yan; Huang, Yan‐Yan; Xu, Yong‐Ju; Shi, Jun; Lei, Yang; Zheng, Ai‐Ping

    2015-01-01

    Abstract Rice false smut has become an increasingly serious disease in rice (Oryza sativa L.) production worldwide. The typical feature of this disease is that the fungal pathogen Ustilaginoidea virens (Uv) specifically infects rice flower and forms false smut ball, the ustiloxin‐containing ball‐like fungal colony, of which the size is usually several times larger than that of a mature rice seed. However, the underlying mechanisms of Uv‐rice interaction are poorly understood. Here, we applied time‐course microscopic and transcriptional approaches to investigate rice responses to Uv infection. The results demonstrated that the flower‐opening process and expression of associated transcription factors, including ARF6 and ARF8, were inhibited in Uv‐infected spikelets. The ovaries in infected spikelets were interrupted in fertilization and thus were unable to set seeds. However, a number of grain‐filling‐related genes, including seed storage protein genes, starch anabolism genes and endosperm‐specific transcription factors (RISBZ1 and RPBF), were highly transcribed as if the ovaries were fertilized. In addition, critical defense‐related genes like NPR1 and PR1 were downregulated by Uv infection. Our data imply that Uv may hijack host nutrient reservoir by activation of the grain‐filling network because of growth and formation of false smut balls. PMID:25319482

  17. Condensed tannins from Ficus virens as tyrosinase inhibitors: structure, inhibitory activity and molecular mechanism.

    PubMed

    Chen, Xiao-Xin; Shi, Yan; Chai, Wei-Ming; Feng, Hui-Ling; Zhuang, Jiang-Xing; Chen, Qing-Xi

    2014-01-01

    Condensed tannins from Ficus virens leaves, fruit, and stem bark were isolated and their structures characterized by 13C nuclear magnetic resonance spectrometry, high performance liquid chromatography electrospray ionization mass spectrometry, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results showed that the leaves, fruit, and stem bark condensed tannins were complex mixtures of homo- and heteropolymers of B-type procyanidins and prodelphinidins with degrees of polymerization up to hexamer, dodecamer, and pentadecamer, respectively. Antityrosinase activities of the condensed tannins were studied. The results indicated that the condensed tannins were potent tyrosinase inhibitors. The concentrations for the leaves, fruit, and stem bark condensed tannins leading to 50% enzyme activity were determined to be 131.67, 99.89, and 106.22 μg/ml on monophenolase activity, and 128.42, 43.07, and 74.27 μg/ml on diphenolase activity. The inhibition mechanism, type, and constants of the condensed tannins on the diphenolase activity were further investigated. The results indicated that the condensed tannins were reversible and mixed type inhibitors. Fluorescence quenching, copper interacting, and molecular docking techniques were utilized to unravel the molecular mechanisms of the inhibition. The results showed that the hydroxyl group on the B ring of the condensed tannins could chelate the dicopper irons of the enzyme. Moreover, the condensed tannins could reduce the enzyme product o-quinones into colourless compounds. These results would contribute to the development and design of antityrosinase agents.

  18. A new substance to relax polychaete worms (Annelida) prior to morphological study

    PubMed Central

    Bonyadi-Naeini, Alieh; Rahimian, Hassan; Glasby, Christopher J.

    2016-01-01

    Abstract A variety of chemical substances have been used to relax and/or immobilize polychaete worms, and other invertebrates, prior to specimen preparation for morphological examination. To solve difficulties encountered during the study of nereidid polychaetes (Annelida: Phyllodocida), an experiment was designed and carried out to investigate a new relaxing agent to immobilize nereidid specimens and stimulate pharynx eversion. The new substance, Dentol® (Khoraman laboratory, Iran), a dental anesthetic and antiseptic medicine containing 10% Carvacrol as the effective ingredient, was used for the first time and compared with other substances that have been used traditionally in polychaete studies. Crosstab analysis showed significant differences between different treatment groups, with Dentol® providing much better results for all considered criteria. PMID:27408556

  19. A new substance to relax polychaete worms (Annelida) prior to morphological study.

    PubMed

    Bonyadi-Naeini, Alieh; Rahimian, Hassan; Glasby, Christopher J

    2016-01-01

    A variety of chemical substances have been used to relax and/or immobilize polychaete worms, and other invertebrates, prior to specimen preparation for morphological examination. To solve difficulties encountered during the study of nereidid polychaetes (Annelida: Phyllodocida), an experiment was designed and carried out to investigate a new relaxing agent to immobilize nereidid specimens and stimulate pharynx eversion. The new substance, Dentol® (Khoraman laboratory, Iran), a dental anesthetic and antiseptic medicine containing 10% Carvacrol as the effective ingredient, was used for the first time and compared with other substances that have been used traditionally in polychaete studies. Crosstab analysis showed significant differences between different treatment groups, with Dentol® providing much better results for all considered criteria.

  20. A new substance to relax polychaete worms (Annelida) prior to morphological study.

    PubMed

    Bonyadi-Naeini, Alieh; Rahimian, Hassan; Glasby, Christopher J

    2016-01-01

    A variety of chemical substances have been used to relax and/or immobilize polychaete worms, and other invertebrates, prior to specimen preparation for morphological examination. To solve difficulties encountered during the study of nereidid polychaetes (Annelida: Phyllodocida), an experiment was designed and carried out to investigate a new relaxing agent to immobilize nereidid specimens and stimulate pharynx eversion. The new substance, Dentol® (Khoraman laboratory, Iran), a dental anesthetic and antiseptic medicine containing 10% Carvacrol as the effective ingredient, was used for the first time and compared with other substances that have been used traditionally in polychaete studies. Crosstab analysis showed significant differences between different treatment groups, with Dentol® providing much better results for all considered criteria. PMID:27408556

  1. Genetic diversity analysis reveals that geographical environment plays a more important role than rice cultivar in Villosiclava virens population selection.

    PubMed

    Wang, Fei; Zhang, Shu; Liu, Mei-Gang; Lin, Xian-Song; Liu, Hui-Jiang; Peng, You-Liang; Lin, Yang; Huang, Jun-Bin; Luo, Chao-Xi

    2014-05-01

    Rice false smut caused by Villosiclava virens is an economically important disease of grains worldwide. The genetic diversity of 153 isolates from six fields located in Wuhan (WH), Yichang Wangjia (YCW), Yichang Yaohe (YCY), Huanggang (HG), Yangxin (YX), and Jingzhou (JZ) in Hubei province of China were phylogenetically analyzed to evaluate the influence of environments and rice cultivars on the V. virens populations. Isolates (43) from Wuhan were from two rice cultivars, Wanxian 98 and Huajing 952, while most of the other isolates from fields YCW, YCY, HG, YX, and JZ originated from different rice cultivars with different genetic backgrounds. Genetic diversity of isolates was analyzed using random amplified polymorphic DNA (RAPD) and single-nucleotide polymorphisms (SNP). The isolates from the same cultivars in Wuhan tended to group together, indicating that the cultivars had an important impact on the fungal population. The 110 isolates from individual fields tended to cluster according to geographical origin. The values of Nei's gene diversity (H) and Shannon's information index (I) showed that the genetic diversity among isolates was higher between than within geographical populations. Furthermore, mean genetic distance between groups (0.006) was higher than mean genetic distance within groups (0.0048) according to MEGA 5.2. The pairwise population fixation index (FST) values also showed significant genetic differentiation between most populations. Higher genetic similarity of isolates from individual fields but different rice cultivars suggested that the geographical factor played a more important role in the selection of V. virens isolates than rice cultivars. This information could be used to improve the management strategy for rice false smut by adjusting the cultivation measures, such as controlling fertilizer, water, and planting density, in the rice field to change the microenvironment.

  2. Lower Cambrian polychaete from China sheds light on early annelid evolution.

    PubMed

    Liu, Jianni; Ou, Qiang; Han, Jian; Li, Jinshu; Wu, Yichen; Jiao, Guoxiang; He, Tongjiang

    2015-06-01

    We herein report a fossilized polychaete annelid, Guanshanchaeta felicia gen. et sp. nov., from the Lower Cambrian Guanshan Biota (Cambrian Series 2, stage 4). The new taxon has a generalized polychaete morphology, with biramous parapodia (most of which preserve the evidence of chaetae), an inferred prostomium bearing a pair of appendages, and a bifid pygidium. G. felicia is the first unequivocal annelid reported from the Lower Cambrian of China. It represents one of the oldest annelids among those from other early Paleozoic Lagerstätten including Sirius Passet from Greenland (Vinther et al., Nature 451: 185-188, 2011) and Emu Bay from Kangaroo island (Parry et al., Palaeontology 57: 1091-1103, 2014), and adds to our increasing roll of present-day animal phyla recognized in the early Cambrian Guanshan Biota. This finding expands the panorama of the Cambrian 'explosion' exemplified by the Guanshan Biota, suggesting the presence of many more fossil annelids in the Chengjiang Lagerstätte and the Kaili Biota. In addition, this new taxon increases our knowledge of early polychaete morphology, which suggests that polychaete annelids considerably diversified in the Cambrian. PMID:26017277

  3. Spatial Relationships between Polychaete Assemblages and Environmental Variables over Broad Geographical Scales

    PubMed Central

    Benedetti-Cecchi, Lisandro; Iken, Katrin; Konar, Brenda; Cruz-Motta, Juan; Knowlton, Ann; Pohle, Gerhard; Castelli, Alberto; Tamburello, Laura; Mead, Angela; Trott, Tom; Miloslavich, Patricia; Wong, Melisa; Shirayama, Yoshihisa; Lardicci, Claudio; Palomo, Gabriela; Maggi, Elena

    2010-01-01

    This study examined spatial relationships between rocky shore polychaete assemblages and environmental variables over broad geographical scales, using a database compiled within the Census of Marine Life NaGISA (Natural Geography In Shore Areas) research program. The database consisted of abundance measures of polychaetes classified at the genus and family levels for 74 and 93 sites, respectively, from nine geographic regions. We tested the general hypothesis that the set of environmental variables emerging as potentially important drivers of variation in polychaete assemblages depend on the spatial scale considered. Through Moran's eigenvector maps we indentified three submodels reflecting spatial relationships among sampling sites at intercontinental (>10000 km), continental (1000–5000 km) and regional (20–500 km) scales. Using redundancy analysis we found that most environmental variables contributed to explain a large and significant proportion of variation of the intercontinental submodel both for genera and families (54% and 53%, respectively). A subset of these variables, organic pollution, inorganic pollution, primary productivity and nutrient contamination was also significantly related to spatial variation at the continental scale, explaining 25% and 32% of the variance at the genus and family levels, respectively. These variables should therefore be preferably considered when forecasting large-scale spatial patterns of polychaete assemblages in relation to ongoing or predicted changes in environmental conditions. None of the variables considered in this study were significantly related to the regional submodel. PMID:20886075

  4. Eranno carrerai sp. nov., a new polychaete worm (Lumbrineridae) from coastal waters of China

    NASA Astrophysics Data System (ADS)

    Cai, Wenqian; Li, Xinzheng

    2011-01-01

    In this paper, a new polychaete species, Eranno carrerai sp. nov. from coastal areas of China, is described based on specimens deposited in the Marine Biological Museum of the Chinese Academy of Sciences, Qingdao, collected during 1957 to 1976 from the Yellow Sea, East China Sea and South China Sea at depths of 9-210 m.

  5. Lower Cambrian polychaete from China sheds light on early annelid evolution

    NASA Astrophysics Data System (ADS)

    Liu, Jianni; Ou, Qiang; Han, Jian; Li, Jinshu; Wu, Yichen; Jiao, Guoxiang; He, Tongjiang

    2015-06-01

    We herein report a fossilized polychaete annelid, Guanshanchaeta felicia gen. et sp. nov., from the Lower Cambrian Guanshan Biota (Cambrian Series 2, stage 4). The new taxon has a generalized polychaete morphology, with biramous parapodia (most of which preserve the evidence of chaetae), an inferred prostomium bearing a pair of appendages, and a bifid pygidium. G. felicia is the first unequivocal annelid reported from the Lower Cambrian of China. It represents one of the oldest annelids among those from other early Paleozoic Lagerstätten including Sirius Passet from Greenland (Vinther et al., Nature 451: 185-188, 2008) and Emu Bay from Kangaroo island (Parry et al., Palaeontology 57: 1091-1103, 2014), and adds to our increasing roll of present-day animal phyla recognized in the early Cambrian Guanshan Biota. This finding expands the panorama of the Cambrian `explosion' exemplified by the Guanshan Biota, suggesting the presence of many more fossil annelids in the Chengjiang Lagerstätte and the Kaili Biota. In addition, this new taxon increases our knowledge of early polychaete morphology, which suggests that polychaete annelids considerably diversified in the Cambrian.

  6. Influence of salinity and temperature on the activity of biosurfactants by polychaete-associated isolates.

    PubMed

    Rizzo, Carmen; Michaud, Luigi; Syldatk, Christoph; Hausmann, Rudolf; De Domenico, Emilio; Lo Giudice, Angelina

    2014-02-01

    Influence of different parameters on biosurfactant (BS) activity was carried out on strains that were isolated from the polychaetes Megalomma claparedei, Sabella spallanzanii and Branchiomma luctuosum and additional 30 strains that were previously identified as potential BS producers from crude oil enrichments of the same polychaete specimens. The selection of BS-producing strains from polychaete natural samples was carried out by using standard screening tests. The BS activity by each isolate was evaluated for the effect of salinity and temperature on emulsion production and surface tension reduction, during incubation in mineral medium supplemented with tetradecane or diesel oil. All isolates showed a similar time course of BS activity, and the latter was more influenced by salinity rather than temperature. Some of the BS producers belonged to genera that have not (i.e. Citricoccus, Cellulophaga, Tenacibaculum and Maribacter) or have poorly been (Psychrobacter, Vibrio, and Pseudoalteromonas) reported as able to produce BSs. This is remarkable as some of them have previously been detected in hydrocarbon-enriched samples. Results confirm that filter-feeding polychaetes are an efficient source for the isolation of BS producers. PMID:24170506

  7. First documentation and molecular confirmation of three trematode species (Platyhelminthes: Trematoda) infecting the polychaete Marenzelleria viridis (Annelida: Spionidae).

    PubMed

    Phelan, Krystin; Blakeslee, April M H; Krause, Maureen; Williams, Jason D

    2016-01-01

    Polychaete worms are hosts to a wide range of marine parasites; yet, studies on trematodes using these ecologically important species as intermediate hosts are lacking. During examination of the spionid polychaete Marenzelleria viridis collected on the north shore of Long Island, New York, putative trematode cysts were discovered in the body cavity of these polychaetes. In order to verify these cysts as metacercariae of trematodes, specimens of the eastern mudsnail Ilyanassa obsoleta (a very common first intermediate host of trematodes in the region) were collected for molecular comparison. DNA barcoding using cytochrome C oxidase I regions confirmed the presence of three species of trematodes (Himasthla quissetensis, Lepocreadium setiferoides, and Zoogonus lasius) in both M. viridis and I. obsoleta hosts. Brown bodies were also recovered from polychaetes, and molecular testing confirmed the presence of L. setiferoides and Z. lasius, indicating an immune response of the polychaete leading to encapsulation of the cysts. From the 125 specimens of M. viridis collected in 2014, 95 (76.8 %) were infected with trematodes; of these 95 infected polychaetes, 86 (90.5 %) contained brown bodies. This is the first confirmation that trematodes use M. viridis as a second intermediate host and that this intermediate host demonstrates a clear immune response to metacercarial infection. Future research should explore the role of these polychaetes in trematode life cycles, the effectiveness of the immune response, and transmission pathways to vertebrate definitive hosts.

  8. Matching ecological functioning with polychaete morphology: Consistency patterns along sedimentary habitats

    NASA Astrophysics Data System (ADS)

    Otegui, Mariana B. P.; Brauko, Kalina M.; Pagliosa, Paulo R.

    2016-08-01

    The relationship between form and function is usually evident and reflect causal relationships in ecological interactions. However, the consistency of the taxonomical and functional approaches versus a morphological approach is yet to be assessed and applied to benthic-sediment relationships. Here, we propose a new functional classification based on morphological characteristics using polychaetes. To test the validity of the framework we assess the consistency between polychaete responses to distinct sedimentary environments using morphological, taxonomical and biological traits approaches, and comparing the patterns of polychaete responses at local and regional scales. The selected morphological characteristics were pharynx complexity, jaws presence, feeding palps, head appendages, body appendages, body support structures, branchiae and body regionalization, as well as number of segments, which were categorized according to presence, size, number or type of structure. The novel morphological method was successfully applied and all analyses showed consistent faunal patterns of variation along muddy and sandy habitats at the distinct spatial scales. Nevertheless, in the three case studies the morphological method explained more over the general variability and was more concise than the other two methods, emphasizing the reliability of a functional approach. The distinct set of morphological characteristics found in muddy and sandy habitats reflected two different ecological roles of polychaetes. Discretely motile, small sized and of low sensibility polychaetes prevailed in muddy habitats, while sandy sediments were dominated by organisms with richer and more heterogeneous characteristics. The responses of the morphological analysis were very similar to the taxonomical and biological traits analysis, but with a much higher explanatory power, meaning that morphology provides a robust approach for studying the ecological functionality of marine benthic systems.

  9. Antifungal activity of nano and micro charcoal particle polymers against Paecilomyces variotii, Trichoderma virens and Chaetomium globosum.

    PubMed

    Yang, Hee Jin; Cha, Yun Jeong; Kim, Hern; Choi, Shin Sik

    2016-01-25

    This study investigates the antifungal activity of a polymer integrated with nano-porous charcoal particles against Paecilomyces variotii, Chaetomium globosum, Trichoderma virens, which are all filamentous fungi. The charcoal polymers were prepared by combining charcoal powders with plastic resin under a vacuum to form charcoal particle protrusions on the polymer surface. The mycelial growth of P. variotii and T. virens exhibited a reduction of 10 and 30%, respectively, after the conidia were pre-treated with charcoal polymers, and in particular, no mycelial growth was found in C. globosum during 5 days of culture. The adsorption of Ca(2+) into charcoal was suggested to inhibit growth due to the reduction in the flux of calcium ions (Ca(2+)) into the hyphae. In 5 h, about 15 mM of Ca(2+) were removed from CaCl2 solution with 0.2 g/mL of polymers, and the nano-sized pores of the charcoals on the polymer were responsible for the Ca(2+) adsorption. PMID:26277629

  10. Antifungal activity of nano and micro charcoal particle polymers against Paecilomyces variotii, Trichoderma virens and Chaetomium globosum.

    PubMed

    Yang, Hee Jin; Cha, Yun Jeong; Kim, Hern; Choi, Shin Sik

    2016-01-25

    This study investigates the antifungal activity of a polymer integrated with nano-porous charcoal particles against Paecilomyces variotii, Chaetomium globosum, Trichoderma virens, which are all filamentous fungi. The charcoal polymers were prepared by combining charcoal powders with plastic resin under a vacuum to form charcoal particle protrusions on the polymer surface. The mycelial growth of P. variotii and T. virens exhibited a reduction of 10 and 30%, respectively, after the conidia were pre-treated with charcoal polymers, and in particular, no mycelial growth was found in C. globosum during 5 days of culture. The adsorption of Ca(2+) into charcoal was suggested to inhibit growth due to the reduction in the flux of calcium ions (Ca(2+)) into the hyphae. In 5 h, about 15 mM of Ca(2+) were removed from CaCl2 solution with 0.2 g/mL of polymers, and the nano-sized pores of the charcoals on the polymer were responsible for the Ca(2+) adsorption.

  11. Evaluation of elevated ploidy and asexual reproduction as alternative explanations for geographic parthenogenesis in Eucypris virens ostracods.

    PubMed

    Adolfsson, Sofia; Michalakis, Yannis; Paczesniak, Dorota; Bode, Saskia N S; Butlin, Roger K; Lamatsch, Dunja K; Martins, Maria J F; Schmit, Olivier; Vandekerkhove, Jochen; Jokela, Jukka

    2010-04-01

    Transitions from sexual to asexual reproduction are often coupled with elevations in ploidy. As a consequence, the importance of ploidy per se for the maintenance and spread of asexual populations is unclear. To examine the effects of ploidy and asexual reproduction as independent determinants of the success of asexual lineages, we sampled diploid sexual, diploid asexual, and triploid asexual Eucypris virens ostracods across a European wide range. Applying nuclear and mitochondrial markers, we found that E. virens consists of genetically highly differentiated diploid sexual populations, to the extent that these sexual clades could be considered as cryptic species. All sexual populations were found in southern Europe and North Africa and we found that both diploid asexual and triploid asexual lineages have originated multiple times from several sexual lineages. Therefore, the asexual lineages show a wide variety of genetic backgrounds and very strong population genetic structure across the wide geographic range. Finally, we found that triploid, but not diploid, asexual clones dominate habitats in northern Europe. The limited distribution of diploid asexual lineages, despite their shared ancestry with triploid asexual lineages, strongly suggests that the wider geographic distribution of triploids is due to elevated ploidy rather than to asexuality.

  12. PREVALENCE, PATHOLOGY, AND RISK FACTORS ASSOCIATED WITH STREPTOCOCCUS PHOCAE INFECTION IN SOUTHERN SEA OTTERS (ENHYDRA LUTRIS NEREIS), 2004-10.

    PubMed

    Bartlett, Georgina; Smith, Woutrina; Dominik, Clare; Batac, Francesca; Dodd, Erin; Byrne, Barbara A; Jang, Spencer; Jessup, David; Chantrey, Julian; Miller, Melissa

    2016-01-01

    Recent studies have implicated beta-hemolytic streptococci as opportunistic pathogens of marine mammals, including southern sea otters (Enhydra lutris nereis), but little is known about their prevalence or pathophysiology. Herein, we focus on risk factors for sea otter infection by a single beta-hemolytic streptococcal species, Streptococcus phocae. Streptococcus phocae was first identified as a marine mammal pathogen in 1994, and the first report in southern sea otters was in 2009. Its broad host range encompasses fish, pinnipeds, cetaceans, and mustelids, with S. phocae now recognized as an important pathogen of marine species worldwide. We assessed risk factors and lesion patterns for S. phocae infection in southern sea otters. Using archival necropsy data, S. phocae prevalence was 40.5% in fresh dead otters examined 2004-10. Skin trauma of any type was identified as a significant risk factor for S. phocae infection. The risk of infection was similar regardless of the cause and relative severity of skin trauma, including mating or fight wounds, shark bite, and anthropogenic trauma. Streptococcus phocae-infected sea otters were also more likely to present with abscesses or bacterial septicemia. Our findings highlight the importance of S. phocae as an opportunistic pathogen of sea otters and suggest that the most likely portal of entry is damaged skin. Even tiny skin breaks appear to facilitate bacterial colonization, invasion, abscess formation, and systemic spread. Our data provide important insights for management and care of marine species.

  13. Behavior associated with forced copulation of juvenile Pacific harbor seals (Phoca vitulina richardsi) by southern sea otters (Enhydra lutris nereis)

    USGS Publications Warehouse

    Harris, Heather S.; Oates, Stori C.; Staedler, Michelle M.; Tinker, M. Tim; Jessup, David A.; Harvey, James T.; Miller, Melissa A.

    2010-01-01

    Nineteen occurrences of interspecific sexual behavior between male southern sea otters (Enhydra lutris nereis) and juvenile Pacific harbor seals (Phoca vitulina richardsi) were reported in Monterey Bay, California, between 2000 and 2002. At least three different male sea otters were observed harassing, dragging, guarding, and copulating with harbor seals for up to 7 d postmortem. Carcasses of 15 juvenile harbor seals were recovered, and seven were necropsied in detail by a veterinary pathologist. Necropsy findings from two female sea otters that were recovered dead from male sea otters exhibiting similar behavior are also presented to facilitate a comparison of lesions. The most frequent lesions included superficial skin lacerations; hemorrhage around the nose, eyes, flippers, and perineum; and traumatic corneal erosions or ulcers. The harbor seals sustained severe genital trauma, ranging from vaginal perforation to vagino-cervical transection, and colorectal perforations as a result of penile penetration. One harbor seal developed severe pneumoperitoneum subsequent to vaginal perforation, which was also observed in both female sea otters and has been reported as a postcoital lesion in humans. This study represents the first description of lesions resulting from forced copulation of harbor seals by sea otters and is also the first report of pneu-moperitoneum secondary to forced copulation in a nonhuman animal. Possible explanations for this behavior are discussed in the context of sea otter biology and population demographics.

  14. Linking steroid hormone levels to sexual maturity index and energy reserves in Nereis diversicolor from clean and polluted estuaries.

    PubMed

    Durou, C; Mouneyrac, C

    2007-01-01

    The objective of this work was to compare seasonal variations of reproduction physiology of the ragworm Nereis diversicolor --a key species in estuarine ecosystems--originating from a clean (Authie) and multi-polluted (Seine) estuaries. A particular attention was carried out in female worms, on relationships between sexual maturity stages, energy reserves (glycogen and lipids) and steroid hormone levels (progesterone, 17beta-estradiol, and testosterone). Sexual maturity index (SMI), energy reserves and steroid hormones are clearly influenced by season in worms from both sites. Depleted steroid hormone levels were depicted in specimens exhibiting high sexual maturity stage and energy reserves. Intersite analysis has revealed all over the sampling period:--a sexual precocity in worms from Seine,--glycogen concentrations generally higher in worms from Authie,--no clear tendency for lipids,--no differences in steroid hormone levels. Sexual precocity and lower glycogen levels in Seine could be explained by a specific strategy above all devoted to reproduction in these worms. Chemical stress could be a possible explanation of these observations.

  15. PREVALENCE, PATHOLOGY, AND RISK FACTORS ASSOCIATED WITH STREPTOCOCCUS PHOCAE INFECTION IN SOUTHERN SEA OTTERS (ENHYDRA LUTRIS NEREIS), 2004-10.

    PubMed

    Bartlett, Georgina; Smith, Woutrina; Dominik, Clare; Batac, Francesca; Dodd, Erin; Byrne, Barbara A; Jang, Spencer; Jessup, David; Chantrey, Julian; Miller, Melissa

    2016-01-01

    Recent studies have implicated beta-hemolytic streptococci as opportunistic pathogens of marine mammals, including southern sea otters (Enhydra lutris nereis), but little is known about their prevalence or pathophysiology. Herein, we focus on risk factors for sea otter infection by a single beta-hemolytic streptococcal species, Streptococcus phocae. Streptococcus phocae was first identified as a marine mammal pathogen in 1994, and the first report in southern sea otters was in 2009. Its broad host range encompasses fish, pinnipeds, cetaceans, and mustelids, with S. phocae now recognized as an important pathogen of marine species worldwide. We assessed risk factors and lesion patterns for S. phocae infection in southern sea otters. Using archival necropsy data, S. phocae prevalence was 40.5% in fresh dead otters examined 2004-10. Skin trauma of any type was identified as a significant risk factor for S. phocae infection. The risk of infection was similar regardless of the cause and relative severity of skin trauma, including mating or fight wounds, shark bite, and anthropogenic trauma. Streptococcus phocae-infected sea otters were also more likely to present with abscesses or bacterial septicemia. Our findings highlight the importance of S. phocae as an opportunistic pathogen of sea otters and suggest that the most likely portal of entry is damaged skin. Even tiny skin breaks appear to facilitate bacterial colonization, invasion, abscess formation, and systemic spread. Our data provide important insights for management and care of marine species. PMID:26555115

  16. Changes in contaminant distributions with trophic level in a marine food chain study

    SciTech Connect

    Pruell, R.J.; Johnson, M.W.; Taplin, B.K.; McGovern, D.G.; Montmarquet, B.T.

    1994-12-31

    A laboratory study was designed to investigate the transfer of chlorinated organic contaminants from sediments to marine biota in a simplified marine food chain. Sediments collected from the Passaic River, NJ, which contained high concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), PCBs and chlorinated pesticides, were used as the contamination source. Polychaete worms (Nereis virens) were exposed to Passaic River sediment for 70 days to allow steady-state concentrations to be achieved and then these organisms were fed to a crustacean, the American lobster (Homarus americanus). Contaminant distributions were altered significantly as they passed from sediments to polychaetes and then to the lobster. PCDDs and PCDFs containing four or five chlorines were accumulated by the polychaetes and lobster; however, the highly chlorinated congeners were not accumulated. PCB patterns in lobsters indicated that these organisms metabolized many PCB congeners. Coplanar PCBs did not appear to be metabolized and therefore became enriched relative to total PCB levels in the lobsters. Lobsters also greatly altered the ratios of chlordane and DDT series compounds relative to those in the sediments and polychaetes.

  17. Response of Nereis diversicolor (Polychaeta, Nereidae) populations to reduced wastewater discharge in the polluted estuary of Oued Souss, Bay of Agadir, Morocco

    NASA Astrophysics Data System (ADS)

    Ait Alla, A.; Gillet, P.; Deutsch, B.; Moukrim, A.; Bergayou, H.

    2006-12-01

    Field investigations on the population dynamics of Nereis diversicolor were carried out from January 2002 to December 2003 in the estuary of Oued Souss (southwestern Morocco) to determine the changes caused by setting up of a domestic and industrial wastewater purification plant (M'zar) before and after by the end of wastewater discharges in November 2002 on the structure of the ecosystem. Samples of N. diversicolor were collected monthly in the intertidal zone at low tide before (during 2002) and after (during 2003) the end of wastewater discharges. Separation of cohorts using the Algorithm EM method (McLachlan, G.J., Krishnan, T., 1997. The EM algorithm and extensions. Wiley Series in Probability and Statistics. Wiley, New York, 274 pp.) allowed determination of the growth rate (mm day -1) by cohort and the annual production. The data showed significant differences between populations of Nereis diversicolor before and after the end of wastewater discharges. During the wastewater discharge period (2002), the population had a mean annual density of 1992 ind m -2, a mean annual biomass of 75.52 g DW m -2 and an annual secondary production of 141.3 g DW m -2 with a P/ B ratio of 1.87. After the end of discharges (2003), density, biomass and secondary production decreased significantly. The annual averages for these parameters were 740 ind m -2, 14.16 g DW m -2 and 23.83 g DW m -2, respectively, with a P/ B ratio of 1.68. The important decrease observed in density, biomass and secondary production of Nereis diversicolor may be attributed (a) to the environmental changes observed after the end of wastewater discharges in the estuary of Oued Souss, namely the increase of salinity and the decrease of organic matter content, and (b) to the migration of this species towards other areas.

  18. The diversity and abundance of polychaetes (Annelida) are altered in sediments impacted by alumina refinery discharge in the Northern Territory, Australia.

    PubMed

    Neave, Matthew J; Glasby, Christopher J; McGuinness, Keith A; Parry, David L; Streten-Joyce, Claire; Gibb, Karen S

    2013-12-01

    We collected polychaete diversity and abundance data at a range of impacted and reference sites near an alumina refinery in Melville Bay, northern Australia. The aims were to measure the impact of sediment modified by the alumina refinery discharge on polychaete communities and secondly to gather baseline data from which to measure future changes. Polychaete communities in both soft-bottom habitats and subtidal areas adjacent to mangrove forests were studied. We also developed and deployed an artificial substratum device to sample polychaetes associated with hard-substrate habitats. For each habitat, polychaete community composition was different between impacted and reference sites and at multiple time points. The impact of future changes either from bioremediation or management practices can be measured against these baseline data. Indicator species analysis was used to identify polychaete species that were significantly different at the locations tested, and we discuss their potential as indicator species.

  19. Optimization of hard clams, polychaetes, physical disturbance and denitrifying bacteria of removing nutrients in marine sediment.

    PubMed

    Shen, Hui; Thrush, Simon F; Wan, Xihe; Li, Hui; Qiao, Yi; Jiang, Ge; Sun, Ruijian; Wang, LiBao; He, Peimin

    2016-09-15

    Marine organisms are known to play important roles in transforming nutrients in sediments, however, guidelines to optimize sediment restoration are not available. We conducted a laboratory mesocosm experiment to investigate the role of hard clams, polychaetes, the degree of physical disturbance and denitrifying bacterial concentrations in removing total nitrogen (TN), total phosphorus (TP), and total organic carbon (TOC) in marine sediments. Response surface methodology was employed to analyze the results of initial experiments and in a subsequent experiment identified optimal combinations of parameters. Balancing the TN, TP, TOC removal efficiency, our model predicted 39% TN removal, 33% TP removal, and 42% TOC removal for a 14-day laboratory bioremediation trial using hard clams biomass of 1.2kgm(-2), physical disturbance depth of 16.4cm, bacterial density of 0.18Lm(-2), and polychaetes biomass of 0.16kgm(-2), respectively. These results emphasize the value of combining different species in field-based bioremediation.

  20. Optimization of hard clams, polychaetes, physical disturbance and denitrifying bacteria of removing nutrients in marine sediment.

    PubMed

    Shen, Hui; Thrush, Simon F; Wan, Xihe; Li, Hui; Qiao, Yi; Jiang, Ge; Sun, Ruijian; Wang, LiBao; He, Peimin

    2016-09-15

    Marine organisms are known to play important roles in transforming nutrients in sediments, however, guidelines to optimize sediment restoration are not available. We conducted a laboratory mesocosm experiment to investigate the role of hard clams, polychaetes, the degree of physical disturbance and denitrifying bacterial concentrations in removing total nitrogen (TN), total phosphorus (TP), and total organic carbon (TOC) in marine sediments. Response surface methodology was employed to analyze the results of initial experiments and in a subsequent experiment identified optimal combinations of parameters. Balancing the TN, TP, TOC removal efficiency, our model predicted 39% TN removal, 33% TP removal, and 42% TOC removal for a 14-day laboratory bioremediation trial using hard clams biomass of 1.2kgm(-2), physical disturbance depth of 16.4cm, bacterial density of 0.18Lm(-2), and polychaetes biomass of 0.16kgm(-2), respectively. These results emphasize the value of combining different species in field-based bioremediation. PMID:27371956

  1. [Polychaetes (Annelida: Polychaeta) epibiont on Spondylus americanus (Bivalvia: Spondylidae) from Mochima National Park, Venezuela].

    PubMed

    Liñero Arana, Ildefonso; Díaz Díaz, Oscar

    2006-09-01

    The polychaetes epibiontic on the mollusk Spondylus americanus Hermann, 1781 were extracted from mollusks hand-collected at a depth of 10-30 m in Mochima National Park, Venezuela (10 degrees 21'00" N-63 degrees 23'36" W), using scuba diving gear. Forty-three polychaete species were identified on the 32 bivalve specimens analyzed. The Serpulidae included 17 especies, Eunicidae six and Terebellidae four species. The most abundant species were Hydroides dirampha Mörch, 1863, Pileolaria militaris Claparède, 1868 (Serpulidae), and Notaulax nudicollis Krøyer, 1856 (Sabellidae). Their geographic affinitie were: 51.3% Atlantic, 28.2% widely distributed, 17.9% Amphiamericans, and 2.6% have a disjunct distribution.

  2. The benthic association between a bivalve and a shell boring polychaete and their potential food sources

    NASA Astrophysics Data System (ADS)

    Silina, A. V.; Zhukova, N. V.

    2012-09-01

    The trophic relationships in the association of the Yeso scallop Mizuhopecten yessoensis and its dominant endobiontic polychaete Polydora brevipalpa, which burrows into the scallop's shell, and their potential food sources were studied using the method of fatty acid biochemical markers. It is shown that the differences in the diet of the scallop and the polychaete allow them to coexist in a close association. The trophic role of the association in the benthic community was revealed. The association selectively utilizes the food sources of the environment. It almost does not consume organic matter of bottom sediments, which allows it to coexist with other species in the community of higher order. There is minimal food competition between the association and detritivorous species; however, association can limit the development of species mostly foraging on diatom algae.

  3. Amino acid sequence of the small cadmium-binding protein (MP II) from Nereis diversicolor (annelida, polychaeta). Evidence for a myohemerythrin structure.

    PubMed

    Demuynck, S; Li, K W; Van der Schors, R; Dhainaut-Courtois, N

    1993-10-01

    The primary sequence of the low-molecular-mass cadmium-binding protein metalloprotein II of Nereis diversicolor (Hediste diversicolor, recent denomination) has been determined. This protein is composed of 119 amino acids and has 80.8% identity with the N. diversicolor myohemerythrin [Takagi, T. & Cox, J. A. (1991) FEBS Lett. 285, 25-27]. The fact that iron, which normally binds to myohemerythrin, is not found to be associated with the cadmium-binding protein metalloprotein II in cadmium-exposed animals could be the result of the complete abolition of the iron-binding capacity of the protein due to the binding of cadmium.

  4. In situ relationship between energy reserves and steroid hormone levels in Nereis diversicolor (O.F. Müller) from clean and contaminated sites.

    PubMed

    Mouneyrac, C; Pellerin, J; Moukrim, A; Ait Alla, A; Durou, C; Viault, N

    2006-10-01

    The aim of this study was to investigate, in situ, the temporal effects of urban effluent discharge on energy reserves and steroid hormone levels in the intrasedimentary worm Nereis diversicolor. Results have shown no differences in energy reserves (glycogen, lipids) in organisms originating from a contaminated site (Oued Souss) and a comparatively clean site (Oualidia). Both sites are located on the Moroccan Atlantic coast. In contrast, steroid hormone (progesterone, testosterone, and 17beta-estradiol) levels were significantly decreased in animals from Oued Souss. The differences in the responses suggest that organisms from the polluted site have been exposed to endocrine disruptors.

  5. Managing the Marine Aquarium Trade: Revealing the Data Gaps Using Ornamental Polychaetes

    PubMed Central

    Murray, Joanna M.; Watson, Gordon J.; Giangrande, Adriana; Licciano, Margherita; Bentley, Matt G.

    2012-01-01

    The marine aquarium industry has great potential to generate jobs in low-income coastal communities creating incentives for the maintenance of a healthy coral reef, if effectively managed. In the absence of current monitoring or legislation to govern the trade, baseline information regarding the species, number and source location of animals traded is missing despite being critical for its successful management and sustainability. An industry assessment to establish the number and provenance of species of ornamental polychaetes (sabellids and serpulids) traded was undertaken across UK wholesalers and retailers. Six geographical regions exporting fan worms were identified. Singapore contributed the highest percentage of imports, but of only one worm “type” whereas Bali, the second largest source, supplied five different worm “types”. Over 50% of UK retailers were supplied by one wholesaler while the remainder were stocked by a mixture of one other wholesaler and/or direct imports from the source country. We estimate that up to 18,500 ornamental polychaetes (16,980 sabellids and 1,018 serpulids) are sold annually in the UK revealing a drastic underestimation of currently accepted trade figures. Incorrect identification (based on exporting region or visual characteristics) of traded animals exacerbates the inaccuracy in market quantification, although identification of preserved sabellids using published keys proved just as inconclusive with high within-species variability and the potential for new or cryptic species. A re-description of the polychaete groups traded using a combination of molecular and morphological techniques is necessary for effective identification and market quantification. This study provides the first assessment of ornamental polychaetes but more importantly highlights the issues surrounding the collection of baseline information necessary to manage the aquarium trade. We recommend that future management should be community based and

  6. Managing the marine aquarium trade: revealing the data gaps using ornamental polychaetes.

    PubMed

    Murray, Joanna M; Watson, Gordon J; Giangrande, Adriana; Licciano, Margherita; Bentley, Matt G

    2012-01-01

    The marine aquarium industry has great potential to generate jobs in low-income coastal communities creating incentives for the maintenance of a healthy coral reef, if effectively managed. In the absence of current monitoring or legislation to govern the trade, baseline information regarding the species, number and source location of animals traded is missing despite being critical for its successful management and sustainability. An industry assessment to establish the number and provenance of species of ornamental polychaetes (sabellids and serpulids) traded was undertaken across UK wholesalers and retailers. Six geographical regions exporting fan worms were identified. Singapore contributed the highest percentage of imports, but of only one worm "type" whereas Bali, the second largest source, supplied five different worm "types". Over 50% of UK retailers were supplied by one wholesaler while the remainder were stocked by a mixture of one other wholesaler and/or direct imports from the source country. We estimate that up to 18,500 ornamental polychaetes (16,980 sabellids and 1,018 serpulids) are sold annually in the UK revealing a drastic underestimation of currently accepted trade figures. Incorrect identification (based on exporting region or visual characteristics) of traded animals exacerbates the inaccuracy in market quantification, although identification of preserved sabellids using published keys proved just as inconclusive with high within-species variability and the potential for new or cryptic species. A re-description of the polychaete groups traded using a combination of molecular and morphological techniques is necessary for effective identification and market quantification. This study provides the first assessment of ornamental polychaetes but more importantly highlights the issues surrounding the collection of baseline information necessary to manage the aquarium trade. We recommend that future management should be community based and site

  7. Managing the marine aquarium trade: revealing the data gaps using ornamental polychaetes.

    PubMed

    Murray, Joanna M; Watson, Gordon J; Giangrande, Adriana; Licciano, Margherita; Bentley, Matt G

    2012-01-01

    The marine aquarium industry has great potential to generate jobs in low-income coastal communities creating incentives for the maintenance of a healthy coral reef, if effectively managed. In the absence of current monitoring or legislation to govern the trade, baseline information regarding the species, number and source location of animals traded is missing despite being critical for its successful management and sustainability. An industry assessment to establish the number and provenance of species of ornamental polychaetes (sabellids and serpulids) traded was undertaken across UK wholesalers and retailers. Six geographical regions exporting fan worms were identified. Singapore contributed the highest percentage of imports, but of only one worm "type" whereas Bali, the second largest source, supplied five different worm "types". Over 50% of UK retailers were supplied by one wholesaler while the remainder were stocked by a mixture of one other wholesaler and/or direct imports from the source country. We estimate that up to 18,500 ornamental polychaetes (16,980 sabellids and 1,018 serpulids) are sold annually in the UK revealing a drastic underestimation of currently accepted trade figures. Incorrect identification (based on exporting region or visual characteristics) of traded animals exacerbates the inaccuracy in market quantification, although identification of preserved sabellids using published keys proved just as inconclusive with high within-species variability and the potential for new or cryptic species. A re-description of the polychaete groups traded using a combination of molecular and morphological techniques is necessary for effective identification and market quantification. This study provides the first assessment of ornamental polychaetes but more importantly highlights the issues surrounding the collection of baseline information necessary to manage the aquarium trade. We recommend that future management should be community based and site

  8. Authorship of some polychaete (Annelida) names derived from the works of Renier and Savigny.

    PubMed

    Muir, Alexander I; Petersen, Mary E

    2013-01-01

    Full citations of animal specific or generic names ultimately derived from unpublished manuscripts should commemorate the work of the person who described the new species as well as the person who eventually validly published the name. We suggest that biologists should use the following authorships when citing these names: Terebella infundibulum Renier in Meneghini, 1847 (now used in the genus Myxicola); Nereis coccinea Renier in Meneghini, 1847 (now used in the genus Lumbrineris); Thalassema scutatum Renier in Ranzani, 1817 (now known as Sternaspis scutata); Polynoe Savigny in Lamarck, 1818. The case of Myxicola infundibulum is further complicated by a possible homonymy, and to avoid confusion we suggest that the name is used for the Myxicola species found in the Adriatic.

  9. Carot-4-en-9,10-diol, a conidiation-inducing sesquiterpene diol produced by Trichoderma virens PS1-7 upon exposure to chemical stress from highly active iron chelators.

    PubMed

    Wang, Mengcen; Hashimoto, Makoto; Hashidoko, Yasuyuki

    2013-03-01

    To screen biocontrol agents against Burkholderia plantarii, the causative agent of rice seedling blight, we employed catechol, an analog of the virulence factor tropolone, to obtain chemical stress-resistant microorganisms. The fungal isolate PS1-7, identified as a strain of Trichoderma virens, showed the highest resistance to catechol (20 mM) and exhibited efficacy as a biocontrol agent for rice seedling blight. During investigation of metabolic traits of T. virens PS1-7 exposed to catechol, we found a secondary metabolite that was released extracellularly and uniquely accumulated in the culture. The compound induced by chemical stress due to catechol was subsequently isolated and identified as a sesquiterpene diol, carot-4-en-9,10-diol, based on spectroscopic analyses. T. virens PS1-7 produced carot-4-en-9,10-diol as a metabolic response to tropolone at concentrations from 0.05 to 0.2 mM, and the response was enhanced in a dose-dependent manner, similar to its response to catechol at concentrations from 0.1 to 1 mM. Some iron chelators, such as pyrogallol, gallic acid, salicylic acid, and citric acid, at 0.5 mM also showed activation of T. virens PS1-7 production of carot-4-en-9,10-diol. This sesquiterpene diol, formed in response to chemical stress, promoted conidiation of T. virens PS1-7, suggesting that it is involved in an autoregulatory signaling system. In a bioassay of the metabolic and morphological responses of T. virens PS1-7, conidiation in hyphae grown on potato dextrose agar (PDA) plates was either promoted or induced by carot-4-en-9,10-diol. Carot-4-en-9,10-diol can thus be regarded as an autoregulatory signal in T. virens, and our findings demonstrate that intrinsic intracellular signaling regulates conidiation of T. virens. PMID:23315728

  10. Carot-4-en-9,10-Diol, a Conidiation-Inducing Sesquiterpene Diol Produced by Trichoderma virens PS1-7 upon Exposure to Chemical Stress from Highly Active Iron Chelators

    PubMed Central

    Wang, Mengcen; Hashimoto, Makoto

    2013-01-01

    To screen biocontrol agents against Burkholderia plantarii, the causative agent of rice seedling blight, we employed catechol, an analog of the virulence factor tropolone, to obtain chemical stress-resistant microorganisms. The fungal isolate PS1-7, identified as a strain of Trichoderma virens, showed the highest resistance to catechol (20 mM) and exhibited efficacy as a biocontrol agent for rice seedling blight. During investigation of metabolic traits of T. virens PS1-7 exposed to catechol, we found a secondary metabolite that was released extracellularly and uniquely accumulated in the culture. The compound induced by chemical stress due to catechol was subsequently isolated and identified as a sesquiterpene diol, carot-4-en-9,10-diol, based on spectroscopic analyses. T. virens PS1-7 produced carot-4-en-9,10-diol as a metabolic response to tropolone at concentrations from 0.05 to 0.2 mM, and the response was enhanced in a dose-dependent manner, similar to its response to catechol at concentrations from 0.1 to 1 mM. Some iron chelators, such as pyrogallol, gallic acid, salicylic acid, and citric acid, at 0.5 mM also showed activation of T. virens PS1-7 production of carot-4-en-9,10-diol. This sesquiterpene diol, formed in response to chemical stress, promoted conidiation of T. virens PS1-7, suggesting that it is involved in an autoregulatory signaling system. In a bioassay of the metabolic and morphological responses of T. virens PS1-7, conidiation in hyphae grown on potato dextrose agar (PDA) plates was either promoted or induced by carot-4-en-9,10-diol. Carot-4-en-9,10-diol can thus be regarded as an autoregulatory signal in T. virens, and our findings demonstrate that intrinsic intracellular signaling regulates conidiation of T. virens. PMID:23315728

  11. Toxicity of heavy metals on embryogenesis and larvae of the marine sedentary polychaete Hydroides elegans.

    PubMed

    Gopalakrishnan, S; Thilagam, H; Raja, P V

    2007-02-01

    The toxicity of heavy metals to marine invertebrates has been widely investigated; however, the effects on marine sedentary polychaetes have largely been ignored. The toxicity of copper, aluminium, lead, nickel, and zinc on fertilization, embryogenesis, and larvae of Hydroides elegans was examined in laboratory acute-toxicity tests. Exposure to metal during fertilization or early developmental stages leads to fertilization block and arrested development, which resulted in morphologic abnormalities in embryo and larvae. Fertilization rate showed a drastic decrease at the highest metal concentration tested. Embryos of H. elegans showed a differential response to metals, and the responses were stage-specific. The different morphologic effects of heavy metals reflect differentiation of the early embryonic cells. For individual metals, the toxicity ranking for 24-hour trochophore larvae was Cu > Al > Pb > Ni > Zn, with EC(50) values of 0.122, 0.210, 0.231, 0.316, and 0.391 mg l(-1), respectively. Rate of larval development and embryogenesis were the most sensitive end points, although the latter is more advisable for routine assessment of seawater quality because of its greater simplicity. In addition to bivalves and sea urchins, polychaete embryos can provide biologic criteria for seawater quality taking into account the sensitivity of a polychaete and contributing to the detection of harmful chemicals with no marked effect on the species currently in use in seawater quality bioassays.

  12. Contrasting metal detoxification in polychaetes, bivalves and fish from a contaminated bay.

    PubMed

    Fan, Wenhong; Xu, Zhizhen; Wang, Wen-Xiong

    2015-02-01

    Jinzhou Bay in Bohai, Northern China, is historically contaminated with metals, but the organisms living in such contaminated environments are much less well studied. In this study, we contrasted the different subcellular and detoxification responses of polychaetes, bivalves and fish collected from different contaminated sites in Jinzhou Bay. In polychaete Neanthes japonica, metal-rich granule (MRG) was the main biologically detoxified metal compartment, and metallothionein-like protein (MTLP) detoxified a relatively smaller fraction of accumulated metals. The importance of MRG increased whereas that of MTLP decreased with increasing metal bioaccumulation. Detoxification in the two bivalves was similar to that in the polychaetes. However, the MRG appeared to play only a minor role in metal binding and detoxification in the gills and livers of fish, whereas MTLP was the dominating detoxification pool. Cellular debris was an important pool binding with metals in the three marine animals. Our study highlighted the contrasting cellular binding and detoxification among different marine organisms living in contaminated environments.

  13. The transcriptome and proteome are altered in marine polychaetes (Annelida) exposed to elevated metal levels.

    PubMed

    Neave, Matthew J; Streten-Joyce, Claire; Nouwens, Amanda S; Glasby, Chris J; McGuinness, Keith A; Parry, David L; Gibb, Karen S

    2012-05-17

    Polychaetes are often used in toxicological studies to understand mechanisms of resistance and for biomarker detection, however, we know of only a few genetic pathways involved in resistance. We found the marine polychaete Ophelina sp.1 (Opheliidae) in sediment containing high copper levels and investigated this phenomenon by measuring metal accumulation in the worms and changes in gene and protein expression. We sequenced the transcriptome of Ophelina sp.1 from both the impacted and reference sediments using 454-sequencing and analysed their proteomes using differential in gel electrophoresis (DIGE). We used the sequenced transcriptome to guide protein identification. Transcripts coding for the copper chaperone, Atox1, were up-regulated in the worms inhabiting the high copper sediment. In addition, genes coding for respiratory proteins, detoxification proteins and cytoskeletal proteins were significantly altered in metal-exposed worms; many of these changes were also detected in the proteome. This dual approach has provided a better understanding of heavy metal resistance in polychaetes and we now have a wider range of suitable indicator genes and proteins for future biomarker development.

  14. Development of PLA films containing oregano essential oil (Origanum vulgare L. virens) intended for use in food packaging.

    PubMed

    Llana-Ruiz-Cabello, M; Pichardo, S; Bermúdez, J M; Baños, A; Núñez, C; Guillamón, E; Aucejo, S; Cameán, A M

    2016-08-01

    Consumers' concerns about the environment and health have led to the development of new food packaging materials avoiding petroleum-based matrices and synthetic additives. The present study has developed polylactic acid (PLA) films containing different concentrations of essential oil from Origanum vulgare L. virens (OEO). The effectiveness of this new active packaging was checked for use in ready-to-eat salads. A plasticising effect was observed when OEO was incorporated in PLA films. The rest of the mechanical and physical properties of developed films did not show much change when OEO was included in the film. An antioxidant effect was recorded only for films containing the highest percentages of the active agent (5% and 10%). In addition, films exhibited in vitro antibacterial activity against Staphylococcus aureus, Yersinia enterocolitica, Listeria monocytogenes, Enterococcus faecalis and Staphylococcus carnosus. Moreover, in ready-to-eat salads, antimicrobial activity was only observed against yeast and moulds, where 5% and 10% of OEO was the most effective.

  15. Inter-annual species-level variations in an abyssal polychaete assemblage (Sta. M, NE Pacific, 4000 m)

    NASA Astrophysics Data System (ADS)

    Laguionie-Marchais, Claire; Paterson, Gordon L. J.; Bett, Brian J.; Smith, Kenneth L.; Ruhl, Henry A.

    2016-01-01

    Understanding the dynamics of abyssal community structure and function has become increasingly important as deep-sea resource exploitation and climate change pressures are expected to ramp up. This time-series study investigates macrofaunal polychaete dynamics at a station in the North East Pacific (Sta. M; 35° N 123° W, 4000 m, 1991-2011). Infaunal polychaete species were identified and their proxy biomass and proxy energy use rate estimated. The assemblage comprised 167 species, having a composition consistent with other abyssal areas globally. Significant changes in univariate and multivariate parameters (rank abundance distribution, Simpson's diversity index, and species and functional group composition) were detected across 1991-2011. However, no change in biomass or energy use rate was apparent through the time-series. The largest changes in the polychaete assemblage coincided with both an increase in sinking particulate organic carbon flux to the seafloor in 2007, and a 40 km relocation of the sampling location to a site 100 m shallower, preventing a conclusive assessment of which might drive the observed variation. Analyses prior to the change of sampling location showed that the polychaete assemblage composition dynamics were primary driven by food supply variation. Changes in several species were also lagged to changes in POC flux by 4-10 months. The polychaete fauna exhibited a significant positive relationship between total density and total energy use rate, suggesting population-level tracking of a common resource (e.g. POC flux food supply). Neither compensatory nor energetic zero-sum dynamics were detected among the polychaete assemblage, but the results suggest that the latter occur in the macrofaunal community as a whole. The results do indicate (a) potential control of species composition, and the density of individual key species, by food supply, when the time-series prior to the sampling location was analysed separately, and (b) generally

  16. Effects of single-walled carbon nanotubes on the bioavailability of PCBs in field-contaminated sediments.

    PubMed

    Parks, Ashley N; Chandler, G Thomas; Portis, Lisa M; Sullivan, Julia C; Perron, Monique M; Cantwell, Mark G; Burgess, Robert M; Ho, Kay T; Ferguson, P Lee

    2014-08-01

    Adsorption of hydrophobic organic contaminants (HOCs) to black carbon is a well-studied phenomenon. One emerging class of engineered black carbon materials are single-walled carbon nanotubes (SWNTs). Little research has investigated the potential of SWNT to adsorb and sequester HOCs in complex environmental systems. This study addressed the capacity of SWNT, amended to polychlorinated biphenyl (PCB)-contaminated New Bedford Harbor (NBH) sediment, to reduce the toxicity and bioaccumulation of these HOCs to benthic organisms. Overall, SWNT amendments increased the survival of two benthic estuarine invertebrates, Americamysis bahia and Ampelisca abdita, and reduced the accumulation of PCBs to the benthic polychaete, Nereis virens. Reduction in PCB bioaccumulation by SWNT was independent of Kow. Further, passive sampling-based estimates of interstitial water concentrations indicated that SWNT reduced PCB bioavailability. Results from this study suggest that SWNT are a good adsorbent for PCBs and might be useful for remediation in the future once SWNT manufacturing technology improves and costs decrease.

  17. Neuroanatomy of the Vestimentiferan Tubeworm Lamellibrachia satsuma Provides Insights into the Evolution of the Polychaete Nervous System

    PubMed Central

    Miyamoto, Norio; Shinozaki, Ayuta; Fujiwara, Yoshihiro

    2013-01-01

    Vestimentiferan tubeworms are marine invertebrates that inhabit chemosynthetic environments, and although recent molecular phylogenetic analyses have suggested that vestimentiferan tubeworms are derived from polychaete annelids, they show some morphological features that are different from other polychaetes. For example, vestimentiferans lack a digestive tract and have less body segments and comparative neuroanatomy can provide essential insight into the vestimentiferan body plan and its evolution. In the present study, we investigated the adult nervous system in the vestimentiferan Lamellibrachia satsuma using antibodies against synapsin, serotonin, FMRMamide and acetylated α-tubulin. We also examined the expressions of neural marker genes, elav and synaptotagmin to reveal the distribution of neuronal cell bodies. Brain anatomy shows simple organization in Lamellibrachia compared to other polychaetes. This simplification is probably due to the loss of the digestive tract, passing through the body between the brain and the subesophageal ganglion. In contrast, the ventral nerve cord shows a repeated organizational structure as in the other polychaetes, despite the absence of the multiple segmentation of the trunk. These results suggest that the brain anatomy is variable depending on the function and the condition of surrounding tissues, and that the formation of the rope ladder-like nervous system of the ventral nerve cord is independent from segmentation in polychaetes. PMID:23372830

  18. Metal pollution in a contaminated bay: relationship between metal geochemical fractionation in sediments and accumulation in a polychaete.

    PubMed

    Fan, Wenhong; Xu, Zhizhen; Wang, Wen-Xiong

    2014-08-01

    Jinzhou Bay in Northern China has been seriously contaminated with metals due to the impacts of smelting activities. In this study, we investigated the relationship between metal accumulation in a deposit-feeding polychaete Neanthes japonica and metal concentration and geochemical fractionation (Cd, Cu, Pb, Zn and Ni) in sediments of Jinzhou Bay. Compared with the historical data, metals in the more mobile geochemical fraction (exchangeable and carbonate fractions) were gradually partitioned into the more stable fraction (Fe-Mn oxides) over time. Metal concentration and geochemical fractionation in sediment significantly affected metal bioavailability and accumulation in polychaetes, except for Ni. Metal accumulation in polychaetes was significantly influenced by Fe or Mn content, and to a lesser degree by organic matter. Prediction of metal bioaccumulation in polychaetes was greatly improved by normalizing metal concentrations to Mn content in sediment. The geochemical fractionation of metals in sediments including the exchangeable, organic matter and Fe-Mn oxides were important in controlling the sediment metal bioavailability to polychaetes.

  19. Correlation of the chemical composition of essential oils from Origanum vulgare subsp. virens with their in vitro activity against pathogenic yeasts and filamentous fungi.

    PubMed

    Vale-Silva, Luís; Silva, Maria-João; Oliveira, Daniela; Gonçalves, Maria-José; Cavaleiro, Carlos; Salgueiro, Lígia; Pinto, Eugénia

    2012-02-01

    Origanum vulgare subsp. virens (Hoffmanns. & Link) Bonnier & Layens and its essential oil (EO) are widely used in the treatment of respiratory and cutaneous infections in traditional medicine. In order to establish a basis for its traditional use, the antimicrobial activity of the EO of O. vulgare subsp. virens was evaluated against human fungal pathogens. Different oil samples were studied in order to elucidate the intraspecific chemical variability and its impact on the biological activity. Flowering aerial parts of three samples of O. vulgare subsp. virens were collected in different geographical locations and EOs were isolated from air-dried plant material by hydrodistillation. The oils were analysed by GC and GC-MS. Minimal inhibitory and minimal lethal concentrations were measured by broth macrodilution methods for the oils and their main constituents against human pathogenic fungi and the influence of the oils on the filamentation in Candida albicans was assayed. The effect of the oil samples on cell metabolism and cell membrane integrity was studied by flow cytometry. Significant quantitative differences in chemical composition were found between the EO samples and, while the three samples generally displayed potent fungicidal activity, their antifungal potencies varied and appeared to be intensified by increasing carvacrol content. The inhibition of filamentation, on the other hand, may correlate more with γ-terpinene content. The flow cytometry results confirmed the occurrence of damage to the plasma membrane, although not necessarily as a direct effect of the oil on the membrane. The EO of O. vulgare subsp. virens is a broad-spectrum fungicide, thus justifying its potential for use in the treatment of superficial or mucosal fungal infections. The EO shows significant variability in chemical composition between samples, which, in turn, affects its biological activity. PMID:22016556

  20. Tvbgn3, a β-1,6-Glucanase from the Biocontrol Fungus Trichoderma virens, Is Involved in Mycoparasitism and Control of Pythium ultimum▿

    PubMed Central

    Djonović, Slavica; Pozo, Maria J.; Kenerley, Charles M.

    2006-01-01

    Even though β-1,6-glucanases have been purified from several filamentous fungi, the physiological function has not been conclusively established for any species. In the present study, the role of Tvbgn3, a β-1,6-glucanase from Trichoderma virens, was examined by comparison of wild-type (WT) and transformant strains in which Tvbgn3 was disrupted (GKO) or constitutively overexpressed (GOE). Gene expression analysis revealed induction of Tvbgn3 in the presence of host fungal cell walls, indicating regulation during mycoparasitism. Indeed, while deletion or overexpression of Tvbgn3 had no evident effect on growth and development, GOE and GKO strains showed an enhanced or reduced ability, respectively, to inhibit the growth of the plant pathogen Pythium ultimum compared to results with the WT. The relevance of this activity in the biocontrol ability of T. virens was confirmed in plant bioassays. Deletion of the gene resulted in levels of disease protection that were significantly reduced from WT levels, while GOE strains showed a significantly increased biocontrol capability. These results demonstrate the involvement of β-1,6-glucanase in mycoparasitism and its relevance in the biocontrol activity of T. virens, opening a new avenue for biotechnological applications. PMID:16997978

  1. RNA interference of endochitinases in the sugarcane endophyte Trichoderma virens 223 reduces its fitness as a biocontrol agent of pineapple disease.

    PubMed

    Romão-Dumaresq, Aline S; de Araújo, Welington Luiz; Talbot, Nicholas J; Thornton, Christopher R

    2012-01-01

    The sugarcane root endophyte Trichoderma virens 223 holds enormous potential as a sustainable alternative to chemical pesticides in the control of sugarcane diseases. Its efficacy as a biocontrol agent is thought to be associated with its production of chitinase enzymes, including N-acetyl-ß-D-glucosaminidases, chitobiosidases and endochitinases. We used targeted gene deletion and RNA-dependent gene silencing strategies to disrupt N-acetyl-ß-D-glucosaminidase and endochitinase activities of the fungus, and to determine their roles in the biocontrol of soil-borne plant pathogens. The loss of N-acetyl-ß-D-glucosaminidase activities was dispensable for biocontrol of the plurivorous damping-off pathogens Rhizoctonia solani and Sclerotinia sclerotiorum, and of the sugarcane pathogen Ceratocystis paradoxa, the causal agent of pineapple disease. Similarly, suppression of endochitinase activities had no effect on R. solani and S. sclerotiorum disease control, but had a pronounced effect on the ability of T. virens 223 to control pineapple disease. Our work demonstrates a critical requirement for T. virens 223 endochitinase activity in the biocontrol of C. paradoxa sugarcane disease, but not for general antagonism of other soil pathogens. This may reflect its lifestyle as a sugarcane root endophyte.

  2. Spatial patterns of biodiversity in the Black Sea: An assessment using benthic polychaetes

    NASA Astrophysics Data System (ADS)

    Surugiu, Victor; Revkov, Nikolai; Todorova, Valentina; Papageorgiou, Nafsika; Valavanis, Vasilis; Arvanitidis, Christos

    2010-06-01

    The current study broadens the biodiversity information available for the Black Sea and neighbouring regions and improves our knowledge about the polychaete biogeographic patterns to be discerned in them. There appears to be a well-defined zoogeocline from the Marmara Sea and Bosphorus Strait to the inner parts of the region (Azov Sea), depicted both as a multivariate pattern and in terms of species (or taxa) numbers. The emergent multivariate pattern complies, to a certain extent, with Jakubova's (1935) views: three main sectors can be defined in the basin: (a) Prebosphoric, (b) the Black Sea and, (c) the Azov Sea, whereas the Bosphorus Strait and Marmara Sea show less faunal affinities with the afore-mentioned sectors. Patterns derived both from the cosmopolitan and Atlanto-Mediterranean species closely follow the one coming from the polychaete species and genera inventories. As a general trend, species numbers decrease along with the decrease in salinity towards the inner parts of the region. The trend is homologous to that seen in the benthic invertebrate inventories of all the major European semi-enclosed regional seas. Salinity and food availability appear to be the dominant abiotic factors correlated, though weakly, with the various patterns deriving from the taxonomic/zoogeographic categories. With the exception of the Anatolia, polychaete inventories from all sectors appear to be random samples of the total inventory of the region, in terms of taxonomic distinctness values. Therefore, these sectoral inventories can be used for future biodiversity/environmental impact assessment studies. A massive invasion of Mediterranean species after the opening of the Black Sea, in the lower Quaternary period, appears to be the likely biogeographic mechanism through which the old Sarmatic fauna was almost completely replaced by species of marine origin.

  3. Is polychaete family-level sufficient to assess impact on tropical estuarine gradients?

    NASA Astrophysics Data System (ADS)

    Nóbrega-Silva, Climélia; Patrício, Joana; Marques, João Carlos; Olímpio, Monalisa dos Santos; Farias, Jéssica Natyelle Barros; Molozzi, Joseline

    2016-11-01

    Regular, robust monitoring programs set up to assess the environmental conditions of aquatic systems often target different biological groups. And, of these, macroinvertebrate communities and particularly the class Polychaeta are frequently used. Identifying these organisms takes time, money and specialized expertise to ensure correct identification to the lowest possible taxonomic level. Identification errors can lead to an erroneous assessment. The concept of taxonomic sufficiency has been proposed both to minimize errors and to save time and money. This study tested the usefulness of this concept in tropical estuaries in northeast Brazil. We selected two transitional systems with different degrees of human impact due to different land uses and different conservation systems: the Mamanguape estuary, which is in an environmental conservation unit for sustainable use, and the highly impacted, urban Paraíba do Norte estuary. The results clearly showed that nutrient concentrations were markedly higher in the Paraíba do Norte estuary in the dry season and that the composition of the polychaete assemblages differed between the two estuaries as well as along the spatial gradient of each estuary. The use of either genus or family level led to equivalent representation in each system in terms of taxon richness and both the Margalef and Shannon-Wiener diversity indices. Both taxonomic levels described similar changes in the polychaete assemblage along the estuarine gradients. Based on our findings, the use of a coarser taxonomic level (i.e., family) is a good option when the aim is to implement a monitoring program in tropical estuaries with the polychaete assemblages as one of the target groups. This time-efficient taxonomic resolution can help improve sampling designs and allow long-term monitoring studies without losing much vital information.

  4. Application of "taxocene surrogation" and "taxonomic sufficiency" concepts to fish farming environmental monitoring. Comparison of BOPA index versus polychaete assemblage structure.

    PubMed

    Aguado-Giménez, F; Gairín, J I; Martinez-Garcia, E; Fernandez-Gonzalez, V; Ballester Moltó, M; Cerezo-Valverde, J; Sanchez-Jerez, P

    2015-02-01

    "Taxocene surrogation" and "taxonomic sufficiency" concepts were applied to the monitoring of soft bottoms macrobenthic assemblages influenced by fish farming following two approaches. Polychaete assemblage evaluation through multivariate analysis and the benthic index BOPA were compared. Six fish farms along the Spanish Mediterranean coast were monitored. Polychaete assemblage provided a suitable picture of the impact gradient, being correlated with total free sulphides. BOPA did not support the impact gradient described by the polychaete assemblage, providing erroneous categorizations. The inclusion of several polychaete families, which were locally identified as indicative of affection to recalculate BOPA, resulted in an improved diagnosis and correlation with the impact gradient. Nevertheless, frequent misclassifications occurred. These results suggest that the structure of polychaete families, sulphides and granulometry conform an appropriate strategy for fish farming monitoring. Biotic indices need to be specifically designed for concrete activities, and regionally validated, because of the environmental plasticity of benthic invertebrates. PMID:25460059

  5. Proteomic profiling during the pre-competent to competent transition of the biofouling polychaete Hydroides elegans.

    PubMed

    Zhang, Yu; Sun, Jin; Zhang, Huoming; Chandramouli, Kondethimmanahalli H; Xu, Ying; He, Li-Sheng; Ravasi, Timothy; Qian, Pei-Yuan

    2014-09-01

    The polychaete, Hydroides elegans, is a tube-building worm that is widely distributed in tropical and subtropical seas. It is a dominant fouling species and thus a major target organism in antifouling research. Here, the first high-throughput proteomic profiling of pre-competent and competent larvae of H. elegans is reported with the identification of 1,519 and 1,322 proteins, respectively. These proteins were associated with a variety of biological processes. However, a large proportion was involved in energy metabolism, redox homeostasis, and microtubule-based processes. A comparative analysis revealed 21 proteins that were differentially regulated in larvae approaching competency.

  6. Effects of the invasive polychaete Marenzelleria spp. on benthic processes and meiobenthos of a species-poor brackish system

    NASA Astrophysics Data System (ADS)

    Urban-Malinga, Barbara; Warzocha, Jan; Zalewski, Mariusz

    2013-07-01

    The effects of the invasive polychaete Marenzelleria spp. on sediment processes and meiobenthos with an emphasis on free-living nematodes of the Vistula Lagoon (southern Baltic Sea) were investigated in a laboratory microcosm experiment. Marenzelleria occupies an open niche and its deep burying behaviour and feeding strategy represent a new function in the study area. Halos of oxidized sediment along Marenzelleria burrow walls indicated oxygen penetration into the burrows but the polychaete had no significant effect on porewater nutrient concentrations. The results showed, however, the density dependent effects of Marenzelleria on ammonium transport. An enhanced ammonium efflux was recorded at high polychaete densities (2000 ind. m- 2) but not at low polychaete densities (300 ind. m- 2). There was no observable impact of the polychaete on total meiobenthic numbers. There was, therefore, no indication that Marenzelleria caused meiofauna mortality. On the contrary, the polychaete significantly affected vertical distribution of meiofauna facilitating the colonization of deeper sediment depths and thus extending the habitat to be used by meiobenthos. In addition, Marenzelleria had a positive impact on the survival of turbellarians. Nevertheless, there was no effect of Marenzelleria on nematode assemblage structure and diversity, indicating that neither the physical presence nor the biological activity of the worm affected the nematode community. This suggests either 1. the limited impact of Marenzelleria on nematodes, resulting from the creation of simple, narrow and un-branched burrows, 2. poor response of nematode community resulting from their low abundance and diversity in the study area, or 3. the overriding role of the harsh chemical environment typical of sediments of the Vistula Lagoon, masking the effect of the bioturbator.

  7. Toxicological evaluation of sediment samples spiked with human pharmaceutical products: Energy status and neuroendocrine effects in marine polychaetes Hediste diversicolor.

    PubMed

    Maranho, L A; André, C; DelValls, T A; Gagné, F; Martín-Díaz, M L

    2015-08-01

    There is a lack of studies about the ecotoxicology of pharmaceutical products on marine environment. To predict possible adverse effects of pharmaceutical products on benthic biota, polychaetes Hediste diversicolor were exposed for 14-days to pharmaceutical-spiked sediments under laboratory conditions. Carbamazepine (CBZ), ibuprofen (IBP) and propranolol (PRO) at concentrations of 500ngg(-1), 50ngg(-1), 5ngg(-1), 0.5ngg(-1) and 0.05ngg(-1), fluoxetine (FX) and 17α-ethynylestradiol (EE2) at concentrations of 100ngg(-1), 10ngg(-1), 1ngg(-1), 0.1ngg(-1) and 0.01ngg(-1), including environmental concentrations (underlined), were spiked in marine sediment samples. After the exposure, cellular energy status (total lipids content - TLP; and mitochondrial electron transport activity - MET), metabolism of monoamines (monoamine oxidase activity - MAO) and inflammation properties (cyclooxygenase activity - COX) were observed in polychaetes. CBZ increased TLP content and MET activity, and decreased MAO activity in polychaetes. IBP did not interfere on the TLP level, but on the MET and MAO activities (environmental concentrations). FX did not cause changes in the energy status. Therefore, environmental concentration diminished MAO activity. EE2 did not affect the energy status, however, MAO activity was significantly lower in polychaetes exposed to environmental concentration. PRO increased TLP level in polychaetes, but not MET activity. MAO activity was significantly lower for polychaetes exposed to environmental concentration. Except FX, all pharmaceuticals showed anti-inflammatory properties confirmed by the decrease of COX activity. Pharmaceutical products affected H. diversicolor physiology and health. As a benthic top predator, adverse effects on sea-worms can potentially culminate in ecosystem perturbations.

  8. Statistical analysis of polychaete population density: dynamics of dominant species and scaling properties in relative abundance fluctuations

    NASA Astrophysics Data System (ADS)

    Quiroz-Martinez, B.; Schmitt, F. G.; Dauvin, J.-C.

    2012-01-01

    We consider here the dynamics of two polychaete populations based on a 20 yr temporal benthic survey of two muddy fine sand communities in the Bay of Morlaix, Western English Channel. These populations display high temporal variability, which is analyzed here using scaling approaches. We find that population densities have heavy tailed probability density functions. We analyze the dynamics of relative species abundance in two different communities of polychaetes by estimating in a novel way a "mean square drift" coefficient which characterizes their fluctuations in relative abundance over time. We show the usefulness of using new tools to approach and model such highly variable population dynamics in marine ecosystems.

  9. Purification, characterization, and cDNA cloning of opine dehydrogenases from the polychaete rockworm Marphysa sanguinea.

    PubMed

    Endo, Noriyuki; Kan-no, Nobuhiro; Nagahisa, Eizoh

    2007-06-01

    Alanopine dehydrogenase (AlDH) and three isoforms of strombine/alanopine dehydrogenase (St/AlDH) were purified from muscle tissue of the polychaete rockworm Marphysa sanguinea. The four enzymes, which can be distinguished by the isoelectric point, are monomeric 42 kDa proteins, possess similar pH-activity profiles, and display specificity for pyruvate and NAD(H). The three isoforms of St/AlDH show equivalent Km and Vmax for glycine and L-alanine and for D-strombine and meso-alanopine. Free amino acid levels in the muscle and D-strombine accumulation in vivo during muscle activity suggest that St/AlDHs function physiologically as StDH. AlDH shows specificity for L-alanine and meso-alanopine, but not for glycine or D-strombine. The amino acid sequences of AlDH and one of the St/AlDH isoforms were determined by a combination of amino acid sequence analysis and cDNA cloning. St/AlDH cDNA consisted of 1586 bp nucleotides that encode a 399-residue protein (43,346.70 Da), and AlDH cDNA consisted of 1587 bp nucleotides that encode a 399-residue protein (43,886.68 Da). The two amino acid sequences deduced from the cDNA displayed 67% amino acid identity, with greatest similarity to that of tauropine dehydrogenase from the polychaete Arabella iricolor. PMID:17350870

  10. Reproductive toxicity assessment of benzo[a]pyrene in the marine polychaete Perinereis nuntia

    NASA Astrophysics Data System (ADS)

    Wu, Qingyang; Wang, Shuqi; Chen, Xiaopeng; Li, Ping

    2016-07-01

    Benzo[a]pyrene (B[a]P) is an increasingly present marine environmental pollutant, yet our understanding of the long-term consequences of reproductive toxicity in marine benthic polychaetes remains limited. To test the reproductive toxicity of B[a]P on polychaetes, Perinereis nuntia was exposed to B[a]P-contaminated artificial seawater and sexual maturation, the sex ratio, number of eggs spawned, fertilization and hatching rated, as well as vitellogenin (VTG) mRNA expression levels were analyzed. A low concentration of B[a]P (2.5 μg/L) had no Effects on the rate of sexual maturation, spawning, or fertilization but significantly increased the sex ratio (female: male) from 1.6±0.15:1 to 2.3±0.18:1, inhibited hatching rate by 27%, and significantly increased VTG mRNA expression level by 3.7-fold following a 60-day exposure, compared with those in the solvent controls. A higher concentration of B[a]P (25 μg/L) caused more serious Effects; sexual maturation, fertilization success, and hatching decreased by 31%, 17% and 46%, respectively, and the sex ratio (female: male) and VTG mRNA gene expression level increased by 54% and 7.1-fold, respectively. These results demonstrate that sublethal concentrations of B[a]P negatively aff ect reproductive performance of the sandworm P. nuntia.

  11. The influence of cadmium on the antioxidant enzyme activities in polychaete Perinereis aibuhitensis Grube (Annelida: Polychaeta)

    NASA Astrophysics Data System (ADS)

    Yuan, Xiutang; Chen, Aihua; Zhou, Yibing; Liu, Haiying; Yang, Dazuo

    2010-07-01

    The infaunal polychaete Perinereis aibuhitensis Grube, distributed widely along Asian coasts and estuaries, is considered a useful animal model in ecotoxicological tests and a promising candidate in biomonitoring programs. This paper deals with the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidases (GSH-Px) in infaunal polychaete P. aibuhitensis exposed to a series of sublethal water-bound cadmium (Cd) concentrations (0, 0.34, 1.72, 3.44, 6.89, and 17.22 mg L-1) under a short-term exposure (1-8 d). The results indicate that the SOD and GSH-Px activities in P. aibuhitensis are stimulated first and then renewed to the original level. The CAT activity of worms decreases at an earlier exposure time but increases to the control values at a later exposure time. Our study suggests that Cd can interfere with the antioxidant defense system of P. aibuhitensis. However, the changes in antioxidant enzyme activities for this species do not show the best promise as biomarkers in Cd biomonitoring of estuarine and coastal zones because weak or non-dose-effect relationships between the antioxidant enzymes activities and Cd levels are found.

  12. Large, motile epifauna interact strongly with harpacticoid copepods and polychaetes at a bathyal site

    NASA Astrophysics Data System (ADS)

    Thistle, David; Eckman, James E.; Paterson, Gordon L. J.

    2008-03-01

    Strengths of interactions among groups of animals in deep-sea-sediment communities are poorly known. Large, motile epifauna (LME) such as sea cucumbers, star fishes, and demersal fishes occur in the deep sea and are sources of predation, disturbance, and habitat alteration and thus have the potential to interact strongly with infauna. At a site off the southwestern coast of the United States (32°57.3'N, 117°32.2'W, 780 m depth), we excluded the LME from five 75- ×75-cm plots with cages. After 143 d, we sampled these plots and five plots of the same size paired with them as controls. Abundances of harpacticoid copepods and polychaetes were significantly lower in cages than in controls. In several cages, nematodes and kinorhynchs were also dramatically less abundant than in paired controls. Results suggest that LME ordinarily affect the infaunal assemblage in such a way that harpacticoids and polychaetes (and perhaps nematodes and kinorhynchs) can maintain higher abundances than they can in the absence of LME, indicating that strong interactions can influence the organization of deep-sea-sediment communities. In a multivariate analysis of environmental parameters, cage and control samples were intermixed, so if the effect is transmitted by alterations of the environment by the LME, the nature of the alterations must be relatively local and remains to be discovered.

  13. Quantitative assessment of Hox complex expression in the indirect development of the polychaete annelid Chaetopterus sp

    NASA Technical Reports Server (NTRS)

    Peterson, K. J.; Irvine, S. Q.; Cameron, R. A.; Davidson, E. H.

    2000-01-01

    A prediction from the set-aside theory of bilaterian origins is that pattern formation processes such as those controlled by the Hox cluster genes are required specifically for adult body plan formation. This prediction can be tested in animals that use maximal indirect development, in which the embryonic formation of the larva and the postembryonic formation of the adult body plan are temporally and spatially distinct. To this end, we quantitatively measured the amount of transcripts for five Hox genes in embryos of a lophotrochozoan, the polychaete annelid Chaetopterus sp. The polychaete Hox complex is shown not to be expressed during embryogenesis, but transcripts of all measured Hox complex genes are detected at significant levels during the initial stages of adult body plan formation. Temporal colinearity in the sequence of their activation is observed, so that activation follows the 3'-5' arrangement of the genes. Moreover, Hox gene expression is spatially localized to the region of teloblastic set-aside cells of the later-stage embryos. This study shows that an indirectly developing lophotrochozoan shares with an indirectly developing deuterostome, the sea urchin, a common mode of Hox complex utilization: construction of the larva, whether a trochophore or dipleurula, does not involve Hox cluster expression, but in both forms the complex is expressed in the set-aside cells from which the adult body plan derives.

  14. Polychaetes associated with the sciaphilic alga community in the northern Aegean Sea: spatial and temporal variability

    NASA Astrophysics Data System (ADS)

    Antoniadou, C.; Nicolaidou, A.; Chintiroglou, C.

    2004-10-01

    Polychaete biodiversity has received little attention despite its importance in biomonitoring. This study describes polychaete diversity, and its spatial and temporal variability in infralittoral, hard substrate assemblages. Seven stations were chosen in the central area of the northern Aegean Sea. At each station, one to three depth levels were set (15, 30 and 40 m). Five replicates were collected by scuba diving with a quadrat sampler (400 cm2) from each station and depth level during summer for the spatial analysis, and seasonally for the study of temporal changes. Common biocoenotic methods were employed (estimation of numerical abundance, mean dominance, frequency, Margalef's richness, Shannon-Weaver index and Pielou's evenness). A total of 5,494 individuals, belonging to 79 species, were counted and classified. Diversity indices were always high. Clustering and multidimensional scaling techniques indicated a high heterogeneity of the stations, although these were all characterized by the sciaphilic alga community. A clear seasonal pattern was not detectable. Summer and autumn samples discriminate, while winter and spring form an even group. The abundance/biomass comparison indicated a dominance of k-strategy patterns, characteristic of stable communities.

  15. MidMedPol: Polychaetes from midlittoral rocky shores in Greece and Italy (Mediterranean Sea)

    PubMed Central

    2013-01-01

    Abstract This paper describes a dataset of polychaetes (Annelida) from 14 midlittoral rocky shore sampling sites in Greece and Italy (Mediterranean Sea). The dataset combines the outcome of four different projects studying the hard substrate midlittoral zone in the Mediterranean between 1984 and 2009. Samples were collected by scraping and collecting the organisms from a framed area. The maximal sampling depth was 1.5 m. In total, 123 polychaete species were recorded, five of which are new records for the respective biogeographic sectors of the Mediterranean. The dataset contains 788 occurrence records, fully annotated with all required metadata. These data contribute to the knowledge of a previously very understudied regional habitat, since at present, comprehensive lists of the midlittoral communities in the Mediterranean are provided through only a few, paper-based, studies. This dataset is one of the first electronic data compilations of the Mediterranean midlittoral zone communities and certainly the most comprehensive of its kind, contributing to the ongoing efforts of the Ocean Biogeographic Information System (OBIS) which aims at filling the gaps in our current knowledge of the world's oceans. It is accessible at http://ipt.vliz.be/resource.do?r=mediterraneanpolychaetaintertidal. PMID:24723761

  16. Development of PLA films containing oregano essential oil (Origanum vulgare L. virens) intended for use in food packaging.

    PubMed

    Llana-Ruiz-Cabello, M; Pichardo, S; Bermúdez, J M; Baños, A; Núñez, C; Guillamón, E; Aucejo, S; Cameán, A M

    2016-08-01

    Consumers' concerns about the environment and health have led to the development of new food packaging materials avoiding petroleum-based matrices and synthetic additives. The present study has developed polylactic acid (PLA) films containing different concentrations of essential oil from Origanum vulgare L. virens (OEO). The effectiveness of this new active packaging was checked for use in ready-to-eat salads. A plasticising effect was observed when OEO was incorporated in PLA films. The rest of the mechanical and physical properties of developed films did not show much change when OEO was included in the film. An antioxidant effect was recorded only for films containing the highest percentages of the active agent (5% and 10%). In addition, films exhibited in vitro antibacterial activity against Staphylococcus aureus, Yersinia enterocolitica, Listeria monocytogenes, Enterococcus faecalis and Staphylococcus carnosus. Moreover, in ready-to-eat salads, antimicrobial activity was only observed against yeast and moulds, where 5% and 10% of OEO was the most effective. PMID:27455176

  17. In silico analysis of β-mannanases and β-mannosidase from Aspergillus flavus and Trichoderma virens UKM1

    NASA Astrophysics Data System (ADS)

    Yee, Chai Sin; Murad, Abdul Munir Abdul; Bakar, Farah Diba Abu

    2013-11-01

    A gene encoding an endo-β-1,4-mannanase from Trichoderma virens UKM1 (manTV) and Aspergillus flavus UKM1 (manAF) was analysed with bioinformatic tools. In addition, A. flavus NRRL 3357 genome database was screened for a β-mannosidase gene and analysed (mndA-AF). These three genes were analysed to understand their gene properties. manTV and manAF both consists of 1,332-bp and 1,386-bp nucleotides encoding 443 and 461 amino acid residues, respectively. Both the endo-β-1,4-mannanases belong to the glycosyl hydrolase family 5 and contain a carbohydrate-binding module family 1 (CBM1). On the other hand, mndA-AF which is a 2,745-bp gene encodes a protein sequence of 914 amino acid residues. This β-mannosidase belongs to the glycosyl hydrolase family 2. Predicted molecular weight of manTV, manAF and mndA-AF are 47.74 kDa, 49.71 kDa and 103 kDa, respectively. All three predicted protein sequences possessed signal peptide sequence and are highly conserved among other fungal β-mannanases and β-mannosidases.

  18. Taqman Real-Time PCR Detects Avipoxvirus DNA in Blood of Hawaìi `Amakihi (Hemignathus virens)

    PubMed Central

    Farias, Margaret E. M.; LaPointe, Dennis A.; Atkinson, Carter T.; Czerwonka, Christopher; Shrestha, Rajesh; Jarvi, Susan I.

    2010-01-01

    Background Avipoxvirus sp. is a significant threat to endemic bird populations on several groups of islands worldwide, including Hawaìi, the Galapagos Islands, and the Canary Islands. Accurate identification and genotyping of Avipoxvirus is critical to the study of this disease and how it interacts with other pathogens, but currently available methods rely on invasive sampling of pox-like lesions and may be especially harmful in smaller birds. Methodology/Principal Findings Here, we present a nested TaqMan Real-Time PCR for the detection of the Avipoxvirus 4b core protein gene in archived blood samples from Hawaiian birds. The method was successful in amplifying Avipoxvirus DNA from packed blood cells of one of seven Hawaiian honeycreepers with confirmed Avipoxvirus infections and 13 of 28 Hawaìi `amakihi (Hemignathus virens) with suspected Avipoxvirus infections based on the presence of pox-like lesions. Mixed genotype infections have not previously been documented in Hawaìi but were observed in two individuals in this study. Conclusions/Significance We anticipate that this method will be applicable to other closely related strains of Avipoxvirus and will become an important and useful tool in global studies of the epidemiology of Avipoxvirus. PMID:20523726

  19. A comparison of variation between a MHC pseudogene and microsatellite loci of the little greenbul (Andropadus virens)

    PubMed Central

    Aguilar, Andres; Smith, Thomas B; Wayne, Robert K

    2005-01-01

    Background We investigated genetic variation of a major histcompatibility complex (MHC) pseudogene (Anvi-DAB1) in the little greenbul (Andropadus virens) from four localities in Cameroon and one in Ivory Coast, West Africa. Previous microsatellite and mitochondrial DNA analyses had revealed little or no genetic differentiation among Cameroon localities but significant differentiation between localities in Cameroon and Ivory Coast. Results Levels of genetic variation, heterozygosity, and allelic diversity were high for the MHC pseudogene in Cameroon. Nucleotide diversity of the MHC pseudogene in Cameroon and Ivory Coast was comparable to levels observed in other avian species that have been studied for variation in nuclear genes. An excess of rare variants for the MHC pseudogene was found in the Cameroon population, but this excess was not statistically significant. Pairwise measures of population differentiation revealed high divergence between Cameroon and Ivory Coast for microsatellites and the MHC locus, although for the latter distance measures were much higher than the comparable microsatellite distances. Conclusion We provide the first ever comparison of variation in a putative MHC pseudogene to variation in neutral loci in a passerine bird. Our results are consistence with the action of neutral processes on the pseudogene and suggest they can provide an independent perspective on demographic history and population substructure. PMID:16159389

  20. The Y137H mutation of VvCYP51 gene confers the reduced sensitivity to tebuconazole in Villosiclava virens.

    PubMed

    Wang, Fei; Lin, Yang; Yin, Wei-Xiao; Peng, You-Liang; Schnabel, Guido; Huang, Jun-Bin; Luo, Chao-Xi

    2015-01-01

    Management of rice false smut disease caused by Villosiclava virens is dependent on demethylation inhibitor (DMI) fungicides. Investigation of molecular mechanisms of resistance is therefore of upmost importance. In this study the gene encoding the target protein for DMI fungicides (VvCYP51) was cloned and investigated. The VvCYP51 gene in the resistant mutant revealed both a change from tyrosine to histidine at position 137 (Y137H) and elevated gene expression compared to the parental isolate. In order to determine which of these mechanisms was responsible for the reduced sensitivity to DMI fungicide tebuconazole, transformants expressing the mutated or the wild type VvCYP51 gene were generated. Transformants carrying the mutated gene were more resistant to tebuconazole compared to control transformants lacking the mutation, but the expression of the VvCYP51 gene was not significantly correlated with EC50 values. The wild type VvCYP51 protein exhibited stronger affinity for tebuconazole compared to the VvCYP51/Y137H in both molecular docking analysis and experimental binding assays. The UV-generated mutant as well as transformants expressing the VvCYP51/Y137H did not exhibit significant fitness penalties based on mycelial growth and spore germination, suggesting that isolates resistant to DMI fungicides based on the Y137H mutation may develop and be competitive in the field. PMID:26631591

  1. Characterization of class II β chain major histocompatibility complex genes in a family of Hawaiian honeycreepers: 'amakihi (Hemignathus virens).

    PubMed

    Jarvi, Susan I; Bianchi, Kiara R; Farias, Margaret Em; Txakeeyang, Ann; McFarland, Thomas; Belcaid, Mahdi; Asano, Ashley

    2016-07-01

    Hawaiian honeycreepers (Drepanidinae) have evolved in the absence of mosquitoes for over five million years. Through human activity, mosquitoes were introduced to the Hawaiian archipelago less than 200 years ago. Mosquito-vectored diseases such as avian malaria caused by Plasmodium relictum and Avipoxviruses have greatly impacted these vulnerable species. Susceptibility to these diseases is variable among and within species. Due to their function in adaptive immunity, the role of major histocompatibility complex genes (Mhc) in disease susceptibility is under investigation. In this study, we evaluate gene organization and levels of diversity of Mhc class II β chain genes (exon 2) in a captive-reared family of Hawaii 'amakihi (Hemignathus virens). A total of 233 sequences (173 bp) were obtained by PCR+1 amplification and cloning, and 5720 sequences were generated by Roche 454 pyrosequencing. We report a total of 17 alleles originating from a minimum of 14 distinct loci. We detected three linkage groups that appear to represent three distinct haplotypes. Phylogenetic analysis revealed one variable cluster resembling classical Mhc sequences (DAB) and one highly conserved, low variability cluster resembling non-classical Mhc sequences (DBB). High net evolutionary divergence values between DAB and DBB resemble that seen between chicken BLB system and YLB system genes. High amino acid identity among non-classical alleles from 12 species of passerines (DBB) and four species of Galliformes (YLB) was found, suggesting that these non-classical passerine sequences may be related to the Galliforme YLB sequences. PMID:26971289

  2. The Y137H mutation of VvCYP51 gene confers the reduced sensitivity to tebuconazole in Villosiclava virens

    PubMed Central

    Wang, Fei; Lin, Yang; Yin, Wei-Xiao; Peng, You-Liang; Schnabel, Guido; Huang, Jun-Bin; Luo, Chao-Xi

    2015-01-01

    Management of rice false smut disease caused by Villosiclava virens is dependent on demethylation inhibitor (DMI) fungicides. Investigation of molecular mechanisms of resistance is therefore of upmost importance. In this study the gene encoding the target protein for DMI fungicides (VvCYP51) was cloned and investigated. The VvCYP51 gene in the resistant mutant revealed both a change from tyrosine to histidine at position 137 (Y137H) and elevated gene expression compared to the parental isolate. In order to determine which of these mechanisms was responsible for the reduced sensitivity to DMI fungicide tebuconazole, transformants expressing the mutated or the wild type VvCYP51 gene were generated. Transformants carrying the mutated gene were more resistant to tebuconazole compared to control transformants lacking the mutation, but the expression of the VvCYP51 gene was not significantly correlated with EC50 values. The wild type VvCYP51 protein exhibited stronger affinity for tebuconazole compared to the VvCYP51/Y137H in both molecular docking analysis and experimental binding assays. The UV-generated mutant as well as transformants expressing the VvCYP51/Y137H did not exhibit significant fitness penalties based on mycelial growth and spore germination, suggesting that isolates resistant to DMI fungicides based on the Y137H mutation may develop and be competitive in the field. PMID:26631591

  3. Fertilization success in marine invertebrates: the influence of gamete age.

    PubMed

    Williams, Mark Elliott; Bentley, Matthew Graeme

    2002-02-01

    Gamete age has been postulated to be unimportant to the fertilization ecology of marine invertebrates. However, recent research suggests that, for some species at least, it may have a direct impact upon fertilization success. We present comparative data on the influence of gamete age on fertilization and development success in several marine invertebrates: the polychaetes Arenicola marina and Nereis virens and the asteroid echinoderm Asterias rubens. Oocytes are much longer lived in the polychaetes than in the echinoderm, with A. marina oocytes still capable of fertilizing and developing normally 96 h post-spawning. Developmental abnormalities and failure to reach blastula tend to occur well before the fertilizable life of the oocytes has expired. Sperm are similarly longer lived in the polychaetes; however, fertilizing capacity is markedly reduced following incubation in conspecific egg-conditioned seawater. These results are discussed in terms of the fertilization strategies of the three species. We further suggest that, for A. marina at least, longer-lived sperm and eggs are central to the fertilization strategy of this species.

  4. Polychaete response to fresh food supply at organically enriched coastal sites: Repercussion on bioturbation potential and trophic structure

    NASA Astrophysics Data System (ADS)

    Venturini, N.; Pires-Vanin, A. M. S.; Salhi, M.; Bessonart, M.; Muniz, P.

    2011-12-01

    We investigated the vertical distribution, abundance, specific and functional structure of polychaete assemblages at four organically enriched sites. The effects of fresh organic matter input from the water column driving by upwelling were evaluated. Temperature and salinity values indicate the intrusion of South Atlantic Central Water (SACW) in spring, a nutrient-rich water mass. The dominance of the conveyor belt transport (CONV) in the station influenced by SACW, in the spring survey, is associated with fresh organic matter input as indicated by higher amounts of polyunsaturated fatty acids. Conversely, the predominance of the diffusive mixing (DIFF) bioturbation category, in the sites without SACW influence is related to the preferential accumulation of more refractive food resources as indicated by higher concentrations of short chain saturated fatty acids. At the site influenced by SACW, the changes in polychaete assemblages were not all evident during proceeding upwelling conditions, but may persist at the end of the upwelling. Polychaetes in the study area seemed to be limited by the quality but not the quantity of food. The delay in polychaete response to fresh food supply may be related to the organic enrichment and the prevalence of refractory material in the sediments.

  5. The effects of salinity changes on the Polychaete Diopatra neapolitana: Impacts on regenerative capacity and biochemical markers.

    PubMed

    Freitas, Rosa; Pires, Adília; Velez, Cátia; Almeida, Ângela; Wrona, Frederick J; Soares, Amadeu M V M; Figueira, Etelvina

    2015-06-01

    Polychaetes have been identified by several authors as a group of marine invertebrates that respond rapidly to anthropogenic stressors. However, studies investigating alterations in Polychaetes affected by climate changes are scarce. Thus, the present study aimed to assess the impact of salinity changes (14, 21, 28, 35, 42g/L) on the physiological and biochemical performance of the Polychaete Diopatra neapolitana, evaluating the species regenerative ability and biochemical alterations. The results obtained demonstrated that organisms exposed to extreme salinity conditions (14, 21 and 42g/L) presented higher mortality rates, needed more days to completely regenerate the missing body region and also regenerated less chaetigers, when compared to organisms exposed to salinities 28 and 35g/L. The present study further demonstrated that D. neapolitana presented significantly lower glycogen and protein content at salinities 21 and 42g/L, which can be explained by higher energy expenditure in the physiological and biochemical processes. A marked impairment of the glutathione redox status was also recorded at salinities 21 and 42g/L. Increased antioxidant enzyme activities were observed at salinity 21g/L while LPO levels were increased at salinity 42g/L. Overall the present study demonstrated that the regenerative capacity of D. neapolitana can be used as a tool to assess environmental changes, namely salinity shifts. Moreover, stress related biomarkers revealed to be useful to evaluate the alterations in Polychaetes due to salinity changes. D. neapolitana revealed to be a good bioindicator to salinity alterations. PMID:25911382

  6. The effects of salinity changes on the Polychaete Diopatra neapolitana: Impacts on regenerative capacity and biochemical markers.

    PubMed

    Freitas, Rosa; Pires, Adília; Velez, Cátia; Almeida, Ângela; Wrona, Frederick J; Soares, Amadeu M V M; Figueira, Etelvina

    2015-06-01

    Polychaetes have been identified by several authors as a group of marine invertebrates that respond rapidly to anthropogenic stressors. However, studies investigating alterations in Polychaetes affected by climate changes are scarce. Thus, the present study aimed to assess the impact of salinity changes (14, 21, 28, 35, 42g/L) on the physiological and biochemical performance of the Polychaete Diopatra neapolitana, evaluating the species regenerative ability and biochemical alterations. The results obtained demonstrated that organisms exposed to extreme salinity conditions (14, 21 and 42g/L) presented higher mortality rates, needed more days to completely regenerate the missing body region and also regenerated less chaetigers, when compared to organisms exposed to salinities 28 and 35g/L. The present study further demonstrated that D. neapolitana presented significantly lower glycogen and protein content at salinities 21 and 42g/L, which can be explained by higher energy expenditure in the physiological and biochemical processes. A marked impairment of the glutathione redox status was also recorded at salinities 21 and 42g/L. Increased antioxidant enzyme activities were observed at salinity 21g/L while LPO levels were increased at salinity 42g/L. Overall the present study demonstrated that the regenerative capacity of D. neapolitana can be used as a tool to assess environmental changes, namely salinity shifts. Moreover, stress related biomarkers revealed to be useful to evaluate the alterations in Polychaetes due to salinity changes. D. neapolitana revealed to be a good bioindicator to salinity alterations.

  7. Labrorostratus caribensis, a new oenonid polychaete from the Grand Caribbean living in the body cavity of a nereidid, with emendation of the genus.

    PubMed

    Hernández-Alcántara, Pablo; Cruz-Pérez, Ismael Narciso; Solís-Weiss, Vivianne

    2015-01-01

    Endoparasitic relationships among polychaetes are uncommon and mostly restricted to about 20 species of the family Oenonidae. We herein describe Labrorostratus caribensis, a new oenonid species living in the body cavity of a nereidid polychaete in Chinchorro Bank (Mexican Caribbean). This is the first report of a parasitic relationship between oenonids and nereidids in the Grand Caribbean region. The new species is diagnosed by the jaw apparatus reduced to only maxillary carriers fused, one simple modified ventral chaeta from midbody and lack of acicular spines. The generic diagnosis is emended to include species without maxillary plates. A synopsis of parasitism among polychaetes worldwide is presented.

  8. The Epl1 and Sm1 proteins from Trichoderma atroviride and Trichoderma virens differentially modulate systemic disease resistance against different life style pathogens in Solanum lycopersicum.

    PubMed

    Salas-Marina, Miguel A; Isordia-Jasso, María I; Islas-Osuna, María A; Delgado-Sánchez, Pablo; Jiménez-Bremont, Juan F; Rodríguez-Kessler, Margarita; Rosales-Saavedra, María T; Herrera-Estrella, Alfredo; Casas-Flores, Sergio

    2015-01-01

    Fungi belonging to the genus Trichoderma, commonly found in soil or colonizing plant roots, exert beneficial effects on plants, including the promotion of growth and the induction of resistance to disease. T. virens and T. atroviride secrete the proteins Sm1 and Epl1, respectively, which elicit local and systemic disease resistance in plants. In this work, we show that these fungi promote growth in tomato (Solanum lycopersicum) plants. T. virens was more effective than T. atroviride in promoting biomass gain, and both fungi were capable of inducing systemic protection in tomato against Alternaria solani, Botrytis cinerea, and Pseudomonas syringae pv. tomato (Pst DC3000). Deletion (KO) of epl1 in T. atroviride resulted in diminished systemic protection against A. solani and B. cinerea, whereas the T. virens sm1 KO strain was less effective in protecting tomato against Pst DC3000 and B. cinerea. Importantly, overexpression (OE) of epl1 and sm1 led to an increase in disease resistance against all tested pathogens. Although the Trichoderma WT strains induced both systemic acquired resistance (SAR)- and induced systemic resistance (ISR)-related genes in tomato, inoculation of plants with OE and KO strains revealed that Epl1 and Sm1 play a minor role in the induction of these genes. However, we found that Epl1 and Sm1 induce the expression of a peroxidase and an α-dioxygenase encoding genes, respectively, which could be important for tomato protection by Trichoderma spp. Altogether, these observations indicate that colonization by beneficial and/or infection by pathogenic microorganisms dictates many of the outcomes in plants, which are more complex than previously thought. PMID:25755658

  9. The Epl1 and Sm1 proteins from Trichoderma atroviride and Trichoderma virens differentially modulate systemic disease resistance against different life style pathogens in Solanum lycopersicum

    PubMed Central

    Salas-Marina, Miguel A.; Isordia-Jasso, María I.; Islas-Osuna, María A.; Delgado-Sánchez, Pablo; Jiménez-Bremont, Juan F.; Rodríguez-Kessler, Margarita; Rosales-Saavedra, María T.; Herrera-Estrella, Alfredo; Casas-Flores, Sergio

    2015-01-01

    Fungi belonging to the genus Trichoderma, commonly found in soil or colonizing plant roots, exert beneficial effects on plants, including the promotion of growth and the induction of resistance to disease. T. virens and T. atroviride secrete the proteins Sm1 and Epl1, respectively, which elicit local and systemic disease resistance in plants. In this work, we show that these fungi promote growth in tomato (Solanum lycopersicum) plants. T. virens was more effective than T. atroviride in promoting biomass gain, and both fungi were capable of inducing systemic protection in tomato against Alternaria solani, Botrytis cinerea, and Pseudomonas syringae pv. tomato (Pst DC3000). Deletion (KO) of epl1 in T. atroviride resulted in diminished systemic protection against A. solani and B. cinerea, whereas the T. virens sm1 KO strain was less effective in protecting tomato against Pst DC3000 and B. cinerea. Importantly, overexpression (OE) of epl1 and sm1 led to an increase in disease resistance against all tested pathogens. Although the Trichoderma WT strains induced both systemic acquired resistance (SAR)- and induced systemic resistance (ISR)-related genes in tomato, inoculation of plants with OE and KO strains revealed that Epl1 and Sm1 play a minor role in the induction of these genes. However, we found that Epl1 and Sm1 induce the expression of a peroxidase and an α-dioxygenase encoding genes, respectively, which could be important for tomato protection by Trichoderma spp. Altogether, these observations indicate that colonization by beneficial and/or infection by pathogenic microorganisms dictates many of the outcomes in plants, which are more complex than previously thought. PMID:25755658

  10. The Epl1 and Sm1 proteins from Trichoderma atroviride and Trichoderma virens differentially modulate systemic disease resistance against different life style pathogens in Solanum lycopersicum.

    PubMed

    Salas-Marina, Miguel A; Isordia-Jasso, María I; Islas-Osuna, María A; Delgado-Sánchez, Pablo; Jiménez-Bremont, Juan F; Rodríguez-Kessler, Margarita; Rosales-Saavedra, María T; Herrera-Estrella, Alfredo; Casas-Flores, Sergio

    2015-01-01

    Fungi belonging to the genus Trichoderma, commonly found in soil or colonizing plant roots, exert beneficial effects on plants, including the promotion of growth and the induction of resistance to disease. T. virens and T. atroviride secrete the proteins Sm1 and Epl1, respectively, which elicit local and systemic disease resistance in plants. In this work, we show that these fungi promote growth in tomato (Solanum lycopersicum) plants. T. virens was more effective than T. atroviride in promoting biomass gain, and both fungi were capable of inducing systemic protection in tomato against Alternaria solani, Botrytis cinerea, and Pseudomonas syringae pv. tomato (Pst DC3000). Deletion (KO) of epl1 in T. atroviride resulted in diminished systemic protection against A. solani and B. cinerea, whereas the T. virens sm1 KO strain was less effective in protecting tomato against Pst DC3000 and B. cinerea. Importantly, overexpression (OE) of epl1 and sm1 led to an increase in disease resistance against all tested pathogens. Although the Trichoderma WT strains induced both systemic acquired resistance (SAR)- and induced systemic resistance (ISR)-related genes in tomato, inoculation of plants with OE and KO strains revealed that Epl1 and Sm1 play a minor role in the induction of these genes. However, we found that Epl1 and Sm1 induce the expression of a peroxidase and an α-dioxygenase encoding genes, respectively, which could be important for tomato protection by Trichoderma spp. Altogether, these observations indicate that colonization by beneficial and/or infection by pathogenic microorganisms dictates many of the outcomes in plants, which are more complex than previously thought.

  11. Toxicity, bioaccumulation, and biotransformation of silver nanoparticles in marine organisms.

    PubMed

    Wang, Huanhua; Ho, Kay T; Scheckel, Kirk G; Wu, Fengchang; Cantwell, Mark G; Katz, David R; Horowitz, Doranne Borsay; Boothman, Warren S; Burgess, Robert M

    2014-12-01

    The toxicity, bioaccumulation, and biotransformation of citrate and polyvinylpyrrolidone (PVP) coated silver nanoparticles (NPs) (AgNP-citrate and AgNP-PVP) in marine organisms via marine sediment exposure was investigated. Results from 7-d sediment toxicity tests indicate that AgNP-citrate and AgNP-PVP did not exhibit toxicity to the amphipod (Ampelisca abdita) and mysid (Americamysis bahia) at ≤75 mg/kg dry wt. A 28-d bioaccumulation study showed that Ag was significantly accumulated in the marine polychaete Nereis virens (N. virens) in the AgNP-citrate, AgNP-PVP and a conventional salt (AgNO3) treatments. Synchrotron X-ray absorption spectroscopy (XAS) results showed the distribution of Ag species in marine sediments amended with AgNP-citrate, AgNP-PVP, and AgNO3 was AgCl (50–65%) > Ag2S (32–42%) > Ag metal (Ag0) (3–11%). In N virens, AgCl (25–59%) and Ag2S (10–31%) generally decreased and, Ag metal (32–44%) increased, relative to the sediments. The patterns of speciation in the worm were different depending upon the coating of the AgNP and both types of AgNPs were different than the AgNO3 salt. These results show that the AgNP surface capping agents influenced Ag uptake, biotransformation, and/or excretion. To our knowledge, this is the first demonstration of the bioaccumulation and speciation of AgNPs in a marine organism (N. virens).

  12. Reversion to virulence and efficacy of an attenuated Canarypox vaccine in Hawai'i 'Amakihi (Hemignathus virens).

    PubMed

    Atkinson, Carter T; Wiegand, Kimberly C; Triglia, Dennis; Jarvi, Susan I

    2012-12-01

    Vaccines may be effective tools for protecting small populations of highly susceptible endangered, captive-reared, or translocated Hawaiian honeycreepers from introduced Avipoxvirus, but their efficacy has not been evaluated. An attenuated Canarypox vaccine that is genetically similar to one of two passerine Avipoxvirus isolates from Hawai'i and distinct from Fowlpox was tested to evaluate whether Hawai'i 'Amakihi (Hemignathus virens) can be protected from wild isolates of Avipoxvirus from the Hawaiian Islands. Thirty-one (31) Hawai'i 'Amakihi were collected from high-elevation habitats on Mauna Kea Volcano, where pox transmission is rare, and randomly divided into two groups. One group was vaccinated with Poximune C, whereas the other group received a sham vaccination with sterile water. Four of 15 (27%) vaccinated birds developed life-threatening disseminated lesions or lesions of unusually long duration, whereas one bird never developed a vaccine-associated lesion or "take." After vaccine lesions healed, vaccinated birds were randomly divided into three groups of five and challenged with either a wild isolate of Fowlpox (FP) from Hawai'i, a Hawai'i 'Amakihi isolate of a Canarypox-like virus (PV1), or a Hawai'i 'Amakihi isolate of a related, but distinct, passerine Avipoxvirus (PV2). Similarly, three random groups of five unvaccinated 'Amakihi were challenged with the same virus isolates. Vaccinated and unvaccinated 'Amakihi challenged with FP had transient infections with no clinical signs of infection. Mortality in vaccinated 'Amakihi challenged with PV1 and PV2 ranged from 0% (0/5) for PV1 to 60% (3/5) for PV2. Mortality in unvaccinated 'Amakihi ranged from 40% (2/5) for PV1 to 100% (5/5) for PV2. Although the vaccine provided some protection against PV1, both potential for vaccine reversion and low efficacy against PV2 preclude its use in captive or wild honeycreepers.

  13. Reversion to virulence and efficacy of an attenuated Canarypox vaccine in Hawai'i 'Amakihi (Hemignathus virens).

    PubMed

    Atkinson, Carter T; Wiegand, Kimberly C; Triglia, Dennis; Jarvi, Susan I

    2012-12-01

    Vaccines may be effective tools for protecting small populations of highly susceptible endangered, captive-reared, or translocated Hawaiian honeycreepers from introduced Avipoxvirus, but their efficacy has not been evaluated. An attenuated Canarypox vaccine that is genetically similar to one of two passerine Avipoxvirus isolates from Hawai'i and distinct from Fowlpox was tested to evaluate whether Hawai'i 'Amakihi (Hemignathus virens) can be protected from wild isolates of Avipoxvirus from the Hawaiian Islands. Thirty-one (31) Hawai'i 'Amakihi were collected from high-elevation habitats on Mauna Kea Volcano, where pox transmission is rare, and randomly divided into two groups. One group was vaccinated with Poximune C, whereas the other group received a sham vaccination with sterile water. Four of 15 (27%) vaccinated birds developed life-threatening disseminated lesions or lesions of unusually long duration, whereas one bird never developed a vaccine-associated lesion or "take." After vaccine lesions healed, vaccinated birds were randomly divided into three groups of five and challenged with either a wild isolate of Fowlpox (FP) from Hawai'i, a Hawai'i 'Amakihi isolate of a Canarypox-like virus (PV1), or a Hawai'i 'Amakihi isolate of a related, but distinct, passerine Avipoxvirus (PV2). Similarly, three random groups of five unvaccinated 'Amakihi were challenged with the same virus isolates. Vaccinated and unvaccinated 'Amakihi challenged with FP had transient infections with no clinical signs of infection. Mortality in vaccinated 'Amakihi challenged with PV1 and PV2 ranged from 0% (0/5) for PV1 to 60% (3/5) for PV2. Mortality in unvaccinated 'Amakihi ranged from 40% (2/5) for PV1 to 100% (5/5) for PV2. Although the vaccine provided some protection against PV1, both potential for vaccine reversion and low efficacy against PV2 preclude its use in captive or wild honeycreepers. PMID:23272348

  14. An ultrastructural study of oogenesis in the polychaete Nephtys hombergi Savigny

    NASA Astrophysics Data System (ADS)

    Bentley, M. G.

    1989-06-01

    The polychaete Nephtys hombergi has an annual cycle of reproduction. Ovaries were fixed for electron microscopy during the gametogenic phase from September to March, and during the breeding and post-breeding periol. Oogenesis takes place entirely within the ovary, the integrity of which is maintained by a network of simple follicle cells. Previtellogenic oocytes have close contacts with the peri-vasal cells which surround the genital blood capillaries. These contacts are lost as the oocytes enter vitellogenesis. The vitellogenic oocytes have a cytology typical of oocytes which are thought to undergo autosynthetic production of protein yolk. Biochemical studies would be required to establish whether heterosynthesis of yolk also occurs. As the oocytes proceed through vitellogenesis, cortical material is laid down near the periphery of the oocyte and a microvillous surface is developed. When the microvillous surface is complete the oocytes, by then hormone independent, are ovulated from the ovary and are ready to be spawned.

  15. Chronic effects of organochlorine exposure in sediment to the marine polychaete Neanthes arenaceodentata

    SciTech Connect

    Murdoch, M.H.; Chapman, P.M.; Johns, D.M.; Paine, M.D.

    1997-07-01

    Organisms exposed to organochlorinated compounds in sediments are likely to suffer chronic rather than acute effects. Thus, acute toxicity tests are unlikely to truly assess their potential impact. A 120-d toxicity test was designed to assess the impact of polychlorinated biphenyl on the marine polychaete Neanthes arenacedodentata. A two-tiered approach was used: Tier 1 involved reference sediment spiked with a range of concentrations of the organochlorine bracketing the concentrations found in natural sediments, and tier 2 involved field sediments collected from a coastal area contaminated with high concentrations of the same organochlorine. Testing measured a number of endpoints, including survival, growth, and reproduction. Survival and growth were unaffected in either tier by any of the test sediments. Reproductive endpoints, however, were depressed in both tiers relative to the reference sediment.

  16. Polychaetes of the genus Ampharete (Polychaeta: Ampharetidae) collected in Icelandic waters during the BIOICE project

    NASA Astrophysics Data System (ADS)

    Parapar, Julio; Helgason, Gudmundur V.; Jirkov, Igor; Moreira, Juan

    2012-09-01

    Based on material collected during the BIOICE project off Iceland, the taxonomy and distribution of eight species of polychaetous annelids belonging to the genus Ampharete (Polychaeta: Ampharetidae) are reviewed. Five of these species were previously reported in the area: Ampharete acutifrons, Ampharete borealis, Ampharete finmarchica, Ampharete octocirrata and Ampharete petersenae; two are new to Icelandic waters: Ampharete baltica and Ampharete lindstroemi; and one is new to science: Ampharete villenai sp. nov. A. petersenae was found for the first time after the original description and is redescribed. A. villenai sp. nov. is primarily characterized by the size, shape and disposition of the paleae, a special kind of chaetae located on the first body chaetiger. Several body characters of high taxonomic relevance in Ampharetidae are reviewed under the SEM. The distribution of each species off the coast of Iceland and a key to all species recorded in European Boreo-Arctic waters is provided.

  17. The effects of carbamazepine on macroinvertebrate species: Comparing bivalves and polychaetes biochemical responses.

    PubMed

    Freitas, Rosa; Almeida, Ângela; Pires, Adília; Velez, Cátia; Calisto, Vânia; Schneider, Rudolf J; Esteves, Valdemar I; Wrona, Frederick J; Figueira, Etelvina; Soares, Amadeu M V M

    2015-11-15

    In the present study, the bivalve Scrobicularia plana and the polychaete Diopatra neapolitana were exposed to an increasing carbamazepine (CBZ) concentration gradient. Both species are among the most widely used bioindicators, and CBZ is one of the most commonly found drugs in the aquatic environment. After a chronic exposure (28 days), the results obtained revealed that CBZ induced biochemical alterations in both species. Our findings demonstrated that S. plana and D. neapolitana reduced the CBZ accumulation rate at higher CBZ concentrations, probably due to their capacity to decrease their feeding rates at stressful conditions. Nevertheless, this defence mechanism was not enough to prevent both species from oxidative stress. In fact, S. plana and D. neapolitana were not able to efficiently activate their antioxidant defence mechanisms which resulted in the increase of lipid peroxidation, especially at the highest CBZ concentrations. Comparing both species, it seems that S. plana was the most sensitive species since stronger biochemical alterations were observed in this species.

  18. Characterization of an anthraquinone fluor from the bioluminescent, pelagic polychaete Tomopteris

    PubMed Central

    Francis, Warren R; Powers, Meghan L; Haddock, Steven H D

    2014-01-01

    Tomopteris is a cosmopolitan genus of polychaetes. Many species produce yellow luminescence in the parapodia when stimulated. Yellow bioluminescence is rare in the ocean, and the components of this luminescent reaction have not been identified. Only a brief description, half a century ago, noted fluorescence in the parapodia with a remarkably similar spectrum to the bioluminescence, which suggested that it may be the luciferin or terminal light-emitter. Here, we report the isolation of the fluorescent yellow–orange pigment found in the luminous exudate and in the body of the animals. Liquid chromatography-mass spectrometry revealed the mass to be 270 m/z with a molecular formula of C15H10O5, which ultimately was shown to be aloe-emodin, an anthraquinone previously found in plants. We speculate that aloe-emodin could be a factor for resonant-energy transfer or the oxyluciferin for Tomopteris bioluminescence. PMID:24760626

  19. Digestive determinants of benzo[a]pyrene and phenanthrene bioaccumulation by a deposit-feeding polychaete

    SciTech Connect

    Penry, D.L.; Weston, D.P.

    1998-11-01

    The uptake of hydrophobic contaminants from ingested sediment can contribute significantly to body burdens of deposit feeders, and feeding behavior and digestive physiology can play important roles in bioaccumulation. The authors examined the uptake of polycyclic aromatic hydrocarbons (PAHs) by the deposit-feeding polychaete Abarenicola pacifica in experiments in which worms were first acclimated to low or high organic carbon sediments with 0.08 or 0.45% total organic carbon, respectively and then transferred to low or high organic carbon test sediments contaminated with radiolabeled phenanthrene or benzo[a]pyrene. Ingestion rate was measurements are essential in many types of bioaccumulation studies because differences in ingestion rates between sediment types may confound some traditional measures of bioavailability. Physiological acclimation to the low or high organic carbon sediments did not appear to affect PAH uptake from the test sediments, but acclimation did affect biotransformation capabilities, particularly for phenanthrene.

  20. Characterization of an anthraquinone fluor from the bioluminescent, pelagic polychaete Tomopteris.

    PubMed

    Francis, Warren R; Powers, Meghan L; Haddock, Steven H D

    2014-12-01

    Tomopteris is a cosmopolitan genus of polychaetes. Many species produce yellow luminescence in the parapodia when stimulated. Yellow bioluminescence is rare in the ocean, and the components of this luminescent reaction have not been identified. Only a brief description, half a century ago, noted fluorescence in the parapodia with a remarkably similar spectrum to the bioluminescence, which suggested that it may be the luciferin or terminal light-emitter. Here, we report the isolation of the fluorescent yellow-orange pigment found in the luminous exudate and in the body of the animals. Liquid chromatography-mass spectrometry revealed the mass to be 270 m/z with a molecular formula of C(15)H(10)O(5), which ultimately was shown to be aloe-emodin, an anthraquinone previously found in plants. We speculate that aloe-emodin could be a factor for resonant-energy transfer or the oxyluciferin for Tomopteris bioluminescence.

  1. Can seamounts provide a good habitat for polychaete annelids? Example of the northeastern Atlantic seamounts

    NASA Astrophysics Data System (ADS)

    Surugiu, Victor; Dauvin, Jean-Claude; Gillet, Patrick; Ruellet, Thierry

    2008-11-01

    Two seamount groups in the northeastern Atlantic were investigated during the 1980s and 1990s: the first was located along the Iberian and African coasts (Galicia, to the north of Portugal; and the Ampere, Gorringe, Josephine and Seine banks near the Madeira-Canary Islands) and the second was located offshore of the southern part of the Azores Islands, included the Atlantis, Hyeres, Irving, Meteor and Plato banks. Among the invertebrates, Annelida, specifically Polychaeta, were studied as surrogates for the biogeographical relationship between coastal and mid-oceanic seamounts in the northeastern Atlantic and the fauna in these areas. The dominant families were Onuphidae (27.46%), Syllidae (18.23%), Eunicidae (15.65%), Amphinomidae (11.45%) and Nereididae (5.61%), representing 78.4% of the total fauna. Data analyses clearly distinguished two seamount groups, one for coastal seamounts and the other offshore. Although the species distinguished and the family composition at the sampled sites were different (i.e., most diversified at the Josephine site and most impoverished at the Irving site), no coastal/offshore faunal impoverishment gradient could be identified. Thus, it seems that seamount environments do not favour any relationship between planktotrophic development and the direct development of polychaetes. Though the number of apparent endemic species was low (<7%), it remained in keeping with other invertebrate groups. Still, while seamounts may well encourage oceanic biodiversity in some zoological groups, this was clearly not the case for the polychaetes. We offer two explanations for this paradox: pelagic productivity and local environmental conditions.

  2. Resistance of polychaete species and trait patterns to simulated species loss in coastal lagoons

    NASA Astrophysics Data System (ADS)

    Faulwetter, Sarah; Papageorgiou, Nafsika; Koulouri, Panayota; Fanini, Lucia; Chatzinikolaou, Eva; Markantonatou, Vasiliki; Pavloudi, Christina; Chatzigeorgiou, Georgios; Keklikoglou, Kleoniki; Vasileiadou, Katerina; Basset, Alberto; Pinna, Maurizio; Rosati, Ilaria; Reizopoulou, Sofia; Nicolaidou, Artemis; Arvanitidis, Christos

    2015-04-01

    The loss of species is known to have negative impacts on the integrity of ecosystems, but the details of this relationship are still far from being fully understood. This study investigates how the distribution patterns of polychaete species and their associated biological trait patterns in six Mediterranean coastal lagoons change under computationally simulated scenarios of random species loss. Species were progressively removed from the full polychaete assemblage and the similarity between the full assemblage and the reduced matrices of both species and trait patterns was calculated. The results indicate the magnitude of changes that might follow species loss in the real world, and allow consideration of the resistance of the system's functional capacity to loss of species, expressed through the species' biological traits as an approximation to functioning. Comparisons were made between the changes in the distribution of species and of traits, as well as between the six different lagoons. While the change of species and trait patterns was strongly correlated within most lagoons, different lagoons showed distinctly different patterns. In disturbed lagoons, the dominance of one or few species was the major driver for the observed patterns and the loss of these species caused extreme changes. Less disturbed lagoons were less susceptible to extreme changes and had a greater resistance towards species loss. Species richness appears to be less important for the ability of the lagoons to buffer changes, instead the initial composition of the assemblage and the identity of the lost species determine the response of the system and our ability to predict changes of the assemblage's functional potential.

  3. Polychaete richness and abundance enhanced in anthropogenically modified estuaries despite high concentrations of toxic contaminants.

    PubMed

    Dafforn, Katherine A; Kelaher, Brendan P; Simpson, Stuart L; Coleman, Melinda A; Hutchings, Pat A; Clark, Graeme F; Knott, Nathan A; Doblin, Martina A; Johnston, Emma L

    2013-01-01

    Ecological communities are increasingly exposed to multiple chemical and physical stressors, but distinguishing anthropogenic impacts from other environmental drivers remains challenging. Rarely are multiple stressors investigated in replicated studies over large spatial scales (>1000 kms) or supported with manipulations that are necessary to interpret ecological patterns. We measured the composition of sediment infaunal communities in relation to anthropogenic and natural stressors at multiple sites within seven estuaries. We observed increases in the richness and abundance of polychaete worms in heavily modified estuaries with severe metal contamination, but no changes in the diversity or abundance of other taxa. Estuaries in which toxic contaminants were elevated also showed evidence of organic enrichment. We hypothesised that the observed response of polychaetes was not a 'positive' response to toxic contamination or a reduction in biotic competition, but due to high levels of nutrients in heavily modified estuaries driving productivity in the water column and enriching the sediment over large spatial scales. We deployed defaunated field-collected sediments from the surveyed estuaries in a small scale experiment, but observed no effects of sediment characteristics (toxic or enriching). Furthermore, invertebrate recruitment instead reflected the low diversity and abundance observed during field surveys of this relatively 'pristine' estuary. This suggests that differences observed in the survey are not a direct consequence of sediment characteristics (even severe metal contamination) but are related to parameters that covary with estuary modification such as enhanced productivity from nutrient inputs and the diversity of the local species pool. This has implications for the interpretation of diversity measures in large-scale monitoring studies in which the observed patterns may be strongly influenced by many factors that covary with anthropogenic modification.

  4. Polychaete Richness and Abundance Enhanced in Anthropogenically Modified Estuaries Despite High Concentrations of Toxic Contaminants

    PubMed Central

    Dafforn, Katherine A.; Kelaher, Brendan P.; Simpson, Stuart L.; Coleman, Melinda A.; Hutchings, Pat A.; Clark, Graeme F.; Knott, Nathan A.; Doblin, Martina A.; Johnston, Emma L.

    2013-01-01

    Ecological communities are increasingly exposed to multiple chemical and physical stressors, but distinguishing anthropogenic impacts from other environmental drivers remains challenging. Rarely are multiple stressors investigated in replicated studies over large spatial scales (>1000 kms) or supported with manipulations that are necessary to interpret ecological patterns. We measured the composition of sediment infaunal communities in relation to anthropogenic and natural stressors at multiple sites within seven estuaries. We observed increases in the richness and abundance of polychaete worms in heavily modified estuaries with severe metal contamination, but no changes in the diversity or abundance of other taxa. Estuaries in which toxic contaminants were elevated also showed evidence of organic enrichment. We hypothesised that the observed response of polychaetes was not a ‘positive’ response to toxic contamination or a reduction in biotic competition, but due to high levels of nutrients in heavily modified estuaries driving productivity in the water column and enriching the sediment over large spatial scales. We deployed defaunated field-collected sediments from the surveyed estuaries in a small scale experiment, but observed no effects of sediment characteristics (toxic or enriching). Furthermore, invertebrate recruitment instead reflected the low diversity and abundance observed during field surveys of this relatively ‘pristine’ estuary. This suggests that differences observed in the survey are not a direct consequence of sediment characteristics (even severe metal contamination) but are related to parameters that covary with estuary modification such as enhanced productivity from nutrient inputs and the diversity of the local species pool. This has implications for the interpretation of diversity measures in large-scale monitoring studies in which the observed patterns may be strongly influenced by many factors that covary with anthropogenic

  5. Textures and traction: how tube-dwelling polychaetes get a leg up

    PubMed Central

    Merz, Rachel Ann

    2015-01-01

    By controlling the traction between its body and the tube wall, a tube-dwelling polychaete can move efficiently from one end of its tube to the other, brace its body during normal functions (e.g., ventilation and feeding), and anchor within its tube avoiding removal by predators. To examine the potential physical interaction between worms and the tubes they live in, scanning electron microscopy was used to reveal and quantify the morphology of worm bodies and the tubes they produce for species representing 13 families of tube-dwelling polychaetes. In the tubes of most species there were macroscopic or nearly macroscopic (∼10 μm–1 mm) bumps or ridges that protruded slightly into the lumen of the tube; these could provide purchase as a worm moves or anchors. At this scale (∼10 μm-1 mm), the surfaces of the chaetal heads that interact with the tube wall were typically small enough to fit within spaces between these bumps (created by the inward projection of exogenous materials incorporated into the tube wall) or ridges (made by secretions on the interior surface of the tube). At a finer scale (0.01–10 μm), there was a second overlap in size, usually between the dentition on the surfaces of chaetae that interact with the tube walls and the texture provided by the secreted strands or microscopic inclusions of the inner linings. These linings had a surprising diversity of micro-textures. The most common micro-texture was a “fabric” of secreted threads, but there were also orderly micro-ridges, wrinkles, and rugose surfaces provided by microorganisms incorporated into the inner tube lining. Understanding the fine structures of tubes in conjunction with the morphologies of the worms that build them gives insight into how tubes are constructed and how worms live within them. PMID:25834379

  6. A comprehensive fate map by intracellular injection of identified blastomeres in the marine polychaete Capitella teleta

    PubMed Central

    2010-01-01

    Background The polychaete annelid Capitella teleta (formerly Capitella sp. I) develops by spiral cleavage and has been the focus of several recent developmental studies aided by a fully sequenced genome. Fate mapping in polychaetes has lagged behind other spiralian taxa, because of technical limitations. Results To generate a modern fate map for C. teleta, we injected 1,1'-dioctadecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate (DiI) into individual identified blastomeres through fourth-quartet micromere formation. Confocal laser scanning microscopy at single-cell resolution was used to characterize blastomere fates during larval stages. Our results corroborate previous observations from classic studies, and show a number of similarities with other spiralian fate maps, including unique and stereotypic fates for individual blastomeres, presence of four discrete body domains arising from the A, B, C and D cell quadrants, generation of anterior ectoderm from first quartet micromeres, and contributions to trunk ectoderm and ventral nerve cord by the 2d somatoblast. Of particular interest are several instances in which the C. teleta fate map deviates from other spiralian fate maps. For example, we identified four to seven distinct origins of mesoderm, all ectomesodermal. In addition, the left and right mesodermal bands arise from 3d and 3c, respectively, whereas 4d generates a small number of trunk muscle cells, the primordial germ cells and the anus. We identified a complex set of blastomere contributions to the posterior gut in C. teleta, which establishes the most complete map of posterior gut territories to date. Conclusions Our detailed cellular descriptions reveal previously underappreciated complexity in the ontogenetic contributions to several spiralian larval tissues, including the mesoderm, nervous system and gut. The formation of the mesodermal bands by 3c and 3d is in stark contrast to other spiralians, in which 4d generates the mesodermal bands. The

  7. The bacterial community associated with the marine polychaete Ophelina sp.1 (Annelida: Opheliidae) is altered by copper and zinc contamination in sediments.

    PubMed

    Neave, Matthew J; Streten-Joyce, Claire; Glasby, Chris J; McGuinness, Keith A; Parry, David L; Gibb, Karen S

    2012-04-01

    Tolerant species of polychaete worms can survive in polluted environments using various resistance mechanisms. One aspect of resistance not often studied in polychaetes is their association with symbiotic bacteria, some of which have resistance to metals and may help the organism to survive. We used "next generation" 454 sequencing of bacterial 16S rRNA sequences associated with polychaetes from a copper- and zinc-polluted harbor and from a reference site to determine bacterial community structure. We found changes in the bacteria at the polluted site, including increases in the abundance of bacteria from the order Alteromonadales. These changes in the bacteria associated with polychaetes may be relatively easy to detect and could be a useful indicator of metal pollution.

  8. High abundance of small zoobenthos around biogenic structures in tidal sediments of the Wadden Sea

    NASA Astrophysics Data System (ADS)

    Reise, K.

    1981-12-01

    On the tidal flats of the island of Sylt (eastern part of the North Sea) the quantity of micro- and meiofauna associated with shoots of seagrass (Zostera noltii), with infaunal bivalves (Macoma balthica), and with tubes and burrows of polychaetes (Pygospio elegans, Pectinaria koreni, Nereis diversicolor, Nereis virens, Arenicola marina) was found to add up to 5 to 33 % of the overall abundance. These structures, taken together, account for 10 to 50 % of the faunal abundance on an average tidal flat at Sylt. The quantitative effect of biogenic structures at the sediment surface (casts and funnels) is small compared to that of tubes and burrows penetrating the anaerobic subsurface layer. In providing stable oxic microenvironments these elite structures frequently bring together more individuals than occur in the entire reducing sediment below surface. Faunal composition of irrigated dwellings of large infauna is different from that of the oxic surface sediment. The common denominator of all elite structures of the subsurface is an oxic halo. Burrows without such a halo are unattractive. There is no evidence that owners of burrows prey on their smaller inmates.

  9. Spatio-temporal changes in trophic categories of infaunal polychaetes near the four wastewater ocean outfalls on Oahu, Hawaii.

    PubMed

    Shuai, Xiufu; Bailey-Brock, Julie H; Lin, David T

    2014-07-01

    This study examines the effect of sewage discharge on benthic polychaete assemblages in the context of their functional trophic categories. We present data spanning 20 years of monitoring benthic invertebrate assemblages and sediment properties at all 4 primary- and secondary-treatment wastewater outfalls servicing Honolulu and the island of Oahu, Hawaii, USA. Samples collected within mandated zones of initial dilution (ZIDs) near outfall discharge sites were compared to samples collected at reference stations at varying distances away. Our findings indicate that sediment properties were not affected by the outfall discharge rate or distance from each ZID. The number of polychaete species in 4 functional trophic categories (carnivore, detritivore, omnivore, and suspension feeder) did not change with the outfall solid loading rate or with distance from each ZID, thus suggesting relatively little organic enrichment. We find no evidence of heavy organic enrichment beyond the designated ZIDs at these 4 wastewater outfalls.

  10. Pyruvate Oxidoreductases Involved in Glycolytic Anaerobic Metabolism of Polychaetes from the Continental Shelf off Central-South Chile

    NASA Astrophysics Data System (ADS)

    González, R. R.; Quiñones, R. A.

    2000-10-01

    The presence of low oxygen conditions in extensive areas of the continental shelf off central-south Chile has important effects on the biochemical adaptations of the organisms living in this ecosystem. Polychaetes assemblages cohabit on the shelf with an extensively distributed prokaryotic community made up of giant filamentous sulfur bacteria (mainly Thioploca sp.). The aim of this research was to characterize the pyruvate oxidoreductases enzymes involved in the biochemical adaptation of these benthic polychaetes. Nine polychaete species ( Paraprionospio pinnata, Nephtys ferruginea, Glycera americana, Haploscoloplos sp., Lumbrineris composita, Sigambra bassi, Aricidea pigmentata , Cossura chilensis, and Pectinaria chilensis) were assayed for lactic dehydrogenase (LDH), octopine dehydrogenase (OPDH), strombine dehydrogenase (STRDH) and alanopine dehydrogenase (ALPDH). Each species had a characteristic number of the pyruvate oxidoreductases assayed ranging from 4 in Paraprionospio pinnata to 1 in Pectinaria chilensis . The pyruvate saturation curves obtained for the enzymes from all species analysed, except L. composita, suggest that NADH can be oxidized at different rates depending on the amino acid used in the reaction with pyruvate. Our results indicate that organisms having more that one pyruvate oxidoreductase present a greater metabolic capacity to cope with functional and environmental hypoxia because these enzymes would better regulate the pyruvate consumption rate during the transition period. Thus, the dominance of Paraprionospio pinnata in the study area and its worldwide distribution is consistent with its higher number of pyruvate oxidoreductases with different pyruvate consumption rates involved in anaerobic metabolism. Finally, a positive allometric relationship was found between body size and the specific activity of ALPDH, STRDH, and maximum pyruvate oxidoreductase specific activity. This latter result suggests a positive scaling of the specific

  11. Dioxin transfer from sediment to the infaunal surface deposit-feeding polychaete Perinereis nuntia in a laboratory-rearing experiment.

    PubMed

    Kono, Kumiko; Tanaka, Hiroyuki; Koyama, Jiro

    2010-07-01

    In the presented study a laboratory experiment was conducted to investigate the transfer of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) from environmentally contaminated marine sediment to an infaunal surface deposit-feeding polychaete, Perinereis nuntia. Polychaetes were exposed to contaminated sediment for 42 d, and elimination of these compounds was studied for an additional 28 d. The sediment uptake rate coefficients (ks), elimination rate constants (k2), and the biota-sediment accumulation factors (BSAFs) were determined for PCDDs, PCDFs (PCDD/Fs), and dioxin-like PCBs. Each of these compounds was transferred from sediment to polychaete except for hepta- and octachlorinated PCDD/Fs. The BSAFs for dioxin-like PCBs (0.13-2.2) were significantly higher than those for PCDD/Fs (0.00022-0.36). The BSAF, ks, and k2 values obtained in the present study indicate that the bioaccumulation characteristics of PCDD/Fs in polychaete are similar to those in fish, and depend on their physical and chemical properties such as hydrophobicity and size of molecules. The ks values for PCDD/Fs and dioxin-like PCBs declined with an increase in their log KOW values, indicating a decrease in bioavailability. The negative exponential relationships of k2 versus KOW were observed for these compounds. The slope for the log-normalized regression of k2 versus KOW for the PCDD/Fs was smaller than that for the dioxin-like PCBs and that of ks versus KOW for the PCDD/Fs. Therefore, the negative exponential relationship of BSAF versus KOW was observed for PCDD/Fs, but not for dioxin-like PCBs.

  12. Reversion to virulence and efficacy of an attenuated canarypox vaccine in Hawai'i 'Amakihi (Hemignathus Virens)

    USGS Publications Warehouse

    Atkinson, Carter T.; Wiegand, Kimberly C.; Triglia, Dennis; Jarvi, Susan I.

    2012-01-01

    Vaccines may be effective tools for protecting small populations of highly susceptible endangered, captive-reared, or translocated Hawaiian honeycreepers from introduced Avipoxvirus, but their efficacy has not been evaluated. An attenuated Canarypox vaccine that is genetically similar to one of two passerine Avipoxvirus isolates from Hawai‘i and distinct from Fowlpox was tested to evaluate whether Hawai‘i ‘Amakihi (Hemignathus virens) can be protected from wild isolates of Avipoxvirus from the Hawaiian Islands. Thirty-one (31) Hawai‘i ‘Amakihi were collected from high-elevation habitats on Mauna Kea Volcano, where pox transmission is rare, and randomly divided into two groups. One group was vaccinated with Poximune C®, whereas the other group received a sham vaccination with sterile water. Four of 15 (27%) vaccinated birds developed life-threatening disseminated lesions or lesions of unusually long duration, whereas one bird never developed a vaccine-associated lesion or “take.” After vaccine lesions healed, vaccinated birds were randomly divided into three groups of five and challenged with either a wild isolate of Fowlpox (FP) from Hawai‘i, a Hawai‘i ‘Amakihi isolate of a Canarypox-like virus (PV1), or a Hawai‘i ‘Amakihi isolate of a related, but distinct, passerine Avipoxvirus (PV2). Similarly, three random groups of five unvaccinated ‘Amakihi were challenged with the same virus isolates. Vaccinated and unvaccinated ‘Amakihi challenged with FP had transient infections with no clinical signs of infection. Mortality in vaccinated ‘Amakihi challenged with PV1 and PV2 ranged from 0% (0/5) for PV1 to 60% (3/5) for PV2. Mortality in unvaccinated ‘Amakihi ranged from 40% (2/5) for PV1 to 100% (5/5) for PV2. Although the vaccine provided some protection against PV1, both potential for vaccine reversion and low efficacy against PV2 preclude its use in captive or wild honeycreepers.

  13. Long-term exposure to caffeine and carbamazepine: Impacts on the regenerative capacity of the polychaete Diopatra neapolitana.

    PubMed

    Pires, Adília; Almeida, Ângela; Correia, Joana; Calisto, Vânia; Schneider, Rudolf J; Esteves, Valdemar I; Soares, Amadeu M V M; Figueira, Etelvina; Freitas, Rosa

    2016-03-01

    The toxicity induced in non-target organisms by pharmaceutical drugs has been the focus of several studies. In the aquatic environment, most of the studies have been devoted to fish and bivalves, while little is known on the impacts induced in polychaetes. The present study evaluated the impacts of carbamazepine and caffeine on the regenerative capacity of Diopatra neapolitana, a polychaete species with high ecological and economic relevance. Under laboratory controlled conditions polychaetes were exposed, during 28 days, to carbamazepine (Ctl-0.0; 0.3; 3.0; 6.0; 9.0 μg/L) and caffeine (Ctl-0.0; 0.5; 3.0; 18.0 μg/L). During the experiment, at days 11, 18, 25, 32, 39 and 46 after amputation, for each specimen, the percentage of the body width regenerated was determined and the number of new segments was counted. The regenerative capacity was assessed considering the number of days needed to achieve full regeneration and the total number of new segments. The obtained results revealed that with the increase of drugs concentrations organisms regenerated less new segments and took longer to completely regenerate.

  14. Bathymetric patterns of polychaete (Annelida) species richness in the continental shelf of the Gulf of California, Eastern Pacific

    NASA Astrophysics Data System (ADS)

    Hernández-Alcántara, Pablo; Salas-de León, David Alberto; Solís-Weiss, Vivianne; Monreal-Gómez, María Adela

    2014-08-01

    The mid-domain effect was tested to evaluate the bathymetric patterns of the polychaete species richness in the Upper and Lower Gulf of California as a possible hypothesis to explain the species richness gradient, exploring the overlapping of species depth ranges towards the middle continental shelf. The bathymetric gradient of the number of species was estimated with the depth ranges of 554 polychaete species, and the mid-domain effect was tested using a Monte Carlo simulation program at bands of 10 m depth. The Upper (251 species) and Lower (491 species) Gulf regions showed clear differences in their faunal composition (Jaccard similarity index = 0.34); the species richness pattern was characterized by a highly significant presence of polychaetes with short depth ranges (< 10 m). The richness distribution could be described as a cubic polynomial curve, but the maximum values in both Gulf regions (141 and 317 species, respectively for Upper and Lower Gulf regions) are strongly biased to shallow waters (40 m). This is not consistent with the peak of diversity at 60-70 m predicted by the model. The observed patterns cannot be reproduced by the mid-domain effect, suggesting the existence of non-random factors affecting the species richness gradients in the Gulf.

  15. Complex depth-related patterns in taxonomic and functional diversity of polychaetes in the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Carvalho, Russell; Wei, Chih-Lin; Rowe, Gilbert; Schulze, Anja

    2013-10-01

    Patterns of taxonomic and functional diversity in polychaete assemblages were examined in the deep northern Gulf of Mexico, including the first analysis of polychaete feeding guild distribution. An analysis of samples from a total of 51 stations located along 7 transects plus additional nearby sites, indicated that density decreased exponentially with depth, with the central locations having higher densities than the eastern and western regions. Alpha diversity was also highest at the central stations associated with the Mississippi trough. The samples can be grouped into three significant clusters based on thirty percent similarity of species composition. BIO-ENV indicated depth, sediment particle size, and export POC were most important variables explaining distributions. The diversity of polychaete feeding guilds was high in the Mississippi trough, upper and mid-slope regions but declined to a few guilds on the Sigsbee abyssal plain. Combining feeding guild analysis with traditional analysis of species diversity contributes to a clearer understanding of trophic diversity in deep-sea benthic assemblages.

  16. Molecular cloning and expression of novel metallothionein (MT) gene in the polychaete Perinereis nuntia exposed to metals.

    PubMed

    Won, Eun-Ji; Rhee, Jae-Sung; Ra, Kongtae; Kim, Kyung-Tae; Au, Doris W T; Shin, Kyung-Hoon; Lee, Jae-Seong

    2011-08-01

    To report a novel metallothionein (MT) gene and evaluate its potency as a biomarker, we clone this MT gene and measured the expression levels in the metal-exposed polychaete Perinereis nuntia. Accumulated metal contents and metallothionein-like proteins (MTLPs), which have been recognized as potential biomarkers, were compared with the relative mRNA expressions of the MT gene of P. nuntia (Pn-MT). In addition, the metal-binding affinity was estimated by recombinant Pn-MT protein. Pn-MT having high cysteine residues with three metal response elements in the promoter region closely clusters with those of other invertebrates. The accumulation patterns of metals were dependent on the exposure times in lead (Pb), cadmium (Cd), and copper (Cu) exposure. Particularly, both MTLP levels and relative mRNA expressions of MT were increased with accumulated metal contents and exposure time in P. nuntia exposed to Pb and Cd. There was no significant modulation of the Pn-MT gene in polychaetes exposed to Zn and As. However, the metal-binding ability of the recombinant Pn-MT protein provides a clear evidence for a high affinity of MT to several metal elements. These results suggest that Pn-MT would play an important role in the detoxification and/or sequestration of specific metals (e.g., Pb and Cd) in P. nuntia and have potential as a molecular biomarker in the monitoring of the marine environment using a polychaete. PMID:22828888

  17. Regulative capacity for eye formation by first quartet micromeres of the polychaete Capitella teleta.

    PubMed

    Yamaguchi, Emi; Dannenberg, Leah C; Amiel, Aldine R; Seaver, Elaine C

    2016-02-01

    The stereotypic cleavage pattern shared by spiralian embryos provides unique opportunities to compare mechanisms of cell fate specification of homologous blastomeres, and can give insights into how changes in fate may have influenced the evolution of novel structures and morphological diversity. The potential of cells to undergo regulation and the timing of cell fate specification were investigated during early development in the polychaete annelid, Capitella teleta. Targeted laser deletions of the first quartet micromeres were performed, with a focus on the eye-forming cells 1a and 1c. Most of the larvae resulting from deletion of the 1a or 1c micromeres lack both the pigment cell and sensory cell of the eye as predicted by the C. teleta fate map. In a minority of cases, however, both left and right larval eye spots develop, suggesting that other blastomeres within the embryo regulate for loss of these cells. Deletion of the 1a and 1c derivatives, 1a(1) or 1c(1), also largely result in larvae with one pigment spot, although there are larvae with two eye spots, suggesting that the ability to regulate for loss of an eye-generating cell persists for an additional cell cycle. Cell deletion in conjunction with intracellular labeling indicates that all four quadrants retain the ability to generate eyes, including those that normally do not. Deletion of all four first quartet micromeres provides evidence that only the first quartet micromeres have eye-forming potential. Additionally, in contrast to the right side of the head where larval and adult eye sensory cells are derived from the same cell (1c), on the left side, the larval and adult eye sensory cells are generated by different embryonic lineages. We hypothesize that cell-cell interactions and cell position are important for regulative ability in Capitella. To our knowledge, this is one of the first detailed deletion studies of the first quartet micromeres and the first convincing example of regulation in

  18. Regulative capacity for eye formation by first quartet micromeres of the polychaete Capitella teleta.

    PubMed

    Yamaguchi, Emi; Dannenberg, Leah C; Amiel, Aldine R; Seaver, Elaine C

    2016-02-01

    The stereotypic cleavage pattern shared by spiralian embryos provides unique opportunities to compare mechanisms of cell fate specification of homologous blastomeres, and can give insights into how changes in fate may have influenced the evolution of novel structures and morphological diversity. The potential of cells to undergo regulation and the timing of cell fate specification were investigated during early development in the polychaete annelid, Capitella teleta. Targeted laser deletions of the first quartet micromeres were performed, with a focus on the eye-forming cells 1a and 1c. Most of the larvae resulting from deletion of the 1a or 1c micromeres lack both the pigment cell and sensory cell of the eye as predicted by the C. teleta fate map. In a minority of cases, however, both left and right larval eye spots develop, suggesting that other blastomeres within the embryo regulate for loss of these cells. Deletion of the 1a and 1c derivatives, 1a(1) or 1c(1), also largely result in larvae with one pigment spot, although there are larvae with two eye spots, suggesting that the ability to regulate for loss of an eye-generating cell persists for an additional cell cycle. Cell deletion in conjunction with intracellular labeling indicates that all four quadrants retain the ability to generate eyes, including those that normally do not. Deletion of all four first quartet micromeres provides evidence that only the first quartet micromeres have eye-forming potential. Additionally, in contrast to the right side of the head where larval and adult eye sensory cells are derived from the same cell (1c), on the left side, the larval and adult eye sensory cells are generated by different embryonic lineages. We hypothesize that cell-cell interactions and cell position are important for regulative ability in Capitella. To our knowledge, this is one of the first detailed deletion studies of the first quartet micromeres and the first convincing example of regulation in

  19. Trace metals partitioning among different sedimentary mineral phases and the deposit-feeding polychaete Armandia brevis.

    PubMed

    Díaz-de-Alba, Margarita; Huerta-Diaz, Miguel Angel; Delgadillo-Hinojosa, Francisco; Hare, Landis; Galindo-Riaño, M Dolores; Siqueiros-Valencia, Arturo

    2016-02-01

    Trace metals (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn) were determined in two operationally defined fractions (HCl and pyrite) in sediments from Ensenada and El Sauzal harbors (Mexico). The HCl fraction had significantly higher metal concentrations relative to the pyrite fraction in both harbors, underlining the weak tendency of most trace metals to associate with pyrite. Exceptionally, Cu was highly pyritized, with degrees of trace metal pyritization (DTMP) >80% in both harbors. Dissolved Fe flux measurements combined with solid phase Fe sulfide data indicated that 98 mt of Fe are precipitated as iron sulfides every year in Ensenada Harbor. These Fe sulfides (and associated trace metals) will remain preserved in the sediments, unless they are perturbed by dredging or sediment resuspension. Calculations indicate that dredging activities could export to the open ocean 0.20±0.13 to (0.30±0.56)×10(3) mt of Cd and Cu, respectively, creating a potential threat to marine benthic organisms. Degrees of pyritization (DOP) values in Ensenada and El Sauzal harbors were relatively low (<25%) while degrees of sulfidization (DOS) were high (~50%) because of the contribution of acid volatile sulfide. DOP values correlated with DTMP values (p≤0.001), indicating that metals are gradually incorporated into pyrite as this mineral is formed. Significant correlations were also found between DTMP values and -log(Ksp(MeS)/Ksp(pyr)) for both harbors, indicating that incorporation of trace metals into the pyrite phase is a function of the solubility product of the corresponding metal sulfide. The order in which elements were pyritized in both harbors was Zn≈Mnpolychaete), suggesting that these labile sedimentary metals are preferentially accumulated by the polychaete, making it a

  20. Lesions and behavior associated with forced copulation of juvenile Pacific harbor seals (Phoca vitulina richardsi) by southern sea otters (Enhydra lutris nereis)

    USGS Publications Warehouse

    Harris, H.S.; Oates, S.C.; Staedler, M.M.; Tinker, M.T.; Jessup, David A.; Harvey, J.T.; Miller, M.A.

    2010-01-01

    Nineteen occurrences of interspecific sexual behavior between male southern sea otters (Enhydra lutris nereis) and juvenile Pacific harbor seals (Phoca vitulina richardsi) were reported in Monterey Bay, California, between 2000 and 2002. At least three different male sea otters were observed harassing, dragging, guarding, and copulating with harbor seals for up to 7 d postmortem. Carcasses of 15 juvenile harbor seals were recovered, and seven were necropsied in detail by a veterinary pathologist. Necropsy findings from two female sea otters that were recovered dead from male sea otters exhibiting similar behavior are also presented to facilitate a comparison of lesions. The most frequent lesions included superficial skin lacerations; hemorrhage around the nose, eyes, flippers, and perineum; and traumatic corneal erosions or ulcers. The harbor seals sustained severe genital trauma, ranging from vaginal perforation to vagino-cervical transection, and colorectal perforations as a result of penile penetration. One harbor seal developed severe pneumoperitoneum subsequent to vaginal perforation, which was also observed in both female sea otters and has been reported as a postcoital lesion in humans. This study represents the first description of lesions resulting from forced copulation of harbor seals by sea otters and is also the first report of pneumoperitoneum secondary to forced copulation in a nonhuman animal. Possible explanations for this behavior are discussed in the context of sea otter biology and population demographics.

  1. Oral papillomatosis caused by Enhydra lutris papillomavirus 1 (ElPV-1) in southern sea otters (Enhydra lutris nereis) in California, USA.

    PubMed

    Ng, Terry Fei Fan; Miller, Melissa A; Kondov, Nikola O; Dodd, Erin M; Batac, Francesca; Manzer, Mike; Ives, Sarah; Saliki, Jeremiah T; Deng, Xutao; Delwart, Eric

    2015-04-01

    The southern sea otter (Enhydra lutris nereis) is a threatened marine sentinel. During postmortem investigations of stranded sea otters from 2004 to 2013 in California, US, papillomas were detected in the oral cavity of at least seven otters via necropsy and histopathology. Next-generation sequencing of viral particles purified from a single papilloma revealed a novel papillomavirus, Enhydra lutris papillomavirus 1 (ElPV-1). The genome of ElPV-1 was obtained, representing the first fully sequenced viral genome from southern sea otters. Phylogenetic analysis of the entire L1 gene, as well as a concatenated protein identities plot of all papillomaviral genes revealed that ElPV-1 is a λ-papillomavirus, related to a raccoon papillomavirus (Procyon lotor papillomavirus type 1) and a canine oral papillomavirus. Immunohistochemical staining, using a cross-reactive bovine papillomavirus antibody, suggested that ElPV-1 is present in intranuclear inclusions and intracytoplasmic keratin granules. Virus-infected cells were scattered throughout the stratum granulosum and stratum spinosum of the gingival and buccal papillomas. Using ElPV-1-specific PCR, we confirmed viral DNA in oral papillomas from all seven stranded sea otters, with identical L1 sequences. This virus is associated with the development of oral papillomatosis in southern sea otters.

  2. Ontogeny of Oxygen Storage Capacity and Diving Ability in the Southern Sea Otter (Enhydra lutris nereis): Costs and Benefits of Large Lungs.

    PubMed

    Thometz, Nicole M; Murray, Michael J; Williams, Terrie M

    2015-01-01

    Small body size, large lungs, and dense pelage contribute to the unique challenges faced by diving sea otters (Enhydra lutris) when compared to other marine mammals. Here we determine the consequences of large lungs on the development of diving ability in southern sea otters (Enhydra lutris nereis) by examining the ontogeny of blood, muscle, and lung oxygen stores and calculating aerobic dive limits (cADL) for immature and mature age classes. Total oxygen storage capacity matures rapidly in sea otters, reaching adult levels by 2 mo postpartum. But this result is driven by exceptional lung capacity at birth, followed by a decrease in mass-specific lung volume with age. Blood and muscle oxygen stores remain well below adult values before weaning, with large pups exhibiting 74% and 54% of adult values, respectively. Slow muscle development limits the capacity of immature sea otters to dive against high positive buoyancy due to comparatively large lungs. Immature sea otters diving with total lung capacity (TLC) experience up to twice the mass-specific positive buoyancy as adults diving with TLC but can reduce these forces to comparable adult levels by using a smaller diving lung volume (DLV). The cADL of a juvenile with DLV is 3.62 min, while the cADL of an adult with TLC is 4.82 min. We find that the magnitude of positive buoyancy experienced by sea otters changes markedly with age and strongly influences the ontogeny of diving ability in this species.

  3. Intersite variations of a battery of biomarkers at different levels of biological organisation in the estuarine endobenthic worm Nereis diversicolor (Polychaeta, Nereididae).

    PubMed

    Fossi Tankoua, O; Buffet, P E; Amiard, J C; Amiard-Triquet, C; Méléder, V; Gillet, P; Mouneyrac, C; Berthet, B

    2012-06-15

    The ragworm Nereis diversicolor has been proposed as a sentinel species for the assessment of estuarine sediment quality. The aim of this study was to test the responsiveness of the worms using a battery of biomarkers in specimens from a moderately contaminated site (Loire estuary, Fr.) and a comparatively cleaner site (Bay of Bourgneuf, Fr.) as a reference site. Ragworms were collected on 7 occasions from April 2008 to October 2009 for the determination of biochemical (GST, AChE, digestive enzymes), physiological (energy reserves (glycogen, lipids and proteins), relationship between length and weight), and behavioural (feeding and burrowing) biomarkers. The biomarker responses were tentatively interpreted in terms of the concept of cascading events potentially responsible for local depletion/extinction of populations submitted to chemical stress. Impairments of AChE and amylase activities, feeding rate, energy reserve concentrations (glycogen and lipids), and the relationship between length and weight showed up differences between the reference site and the Loire estuary despite the latter being far from the most contaminated estuary in France or internationally. However, no links could be established in the Loire estuary ragworms between effects at infra-individual and individual levels, nor with worm population density, even though a small oil spill had occurred in the Loire estuary only one month before the beginning of sampling. PMID:22417766

  4. Accumulation pattern of organochlorine pesticides and polychlorinated biphenyls in sourthern sea otters (Enhydra lutris nereis) found stranded along coastal California, USA

    USGS Publications Warehouse

    Nakata, H.; Kannan, K.; Jing, L.; Thomas, N.J.; Tanabe, S.; Giesy, J.P.

    1998-01-01

    Concentrations of PCBs, DDTs (p,p'-DDE, p,p'-DDD and p,p'-DDT), HCHs (α-, β-, γ-isomers), chlordanes (trans-chlordane, cis-chlordane, trans-nonachlor, cis-nonachlor and oxychlordane) and HCB (hexachlorobenzene were measured in liver, kidney and brain tissues of adult southern sea otters (Enhydra lutris nereis) found stranded along coastal California, USA, during 1992–96. The contamination pattern of organochlorines in sea otters from several locations was in the order of DDTs > PCBs > > CHLs > HCHs > > HCB, whereas those from Monterey Harbor contained greater concentrations of PCBs than of DDTs. Hepatic concentrations of PCBs and DDTs were in the ranges of 58–8700 and 280–5900 ng/g, wet weight, respectively, which varied depending on the geographic location. Sea otters collected from Monterey Harbor contained the greatest concentrations of PCBs and DDTs. In general, accumulation of DDTs, CHLs and PCBs was greater in kidney than in liver, whereas that of HCHs was similar in both the tissues. The gender difference in organochlorine concentrations was less than those reported in cetaceans. The composition of DDTs, HCHs and CHLs compounds in sea otter tissues indicated no recent inputs of these compounds in coastal California. Sea otters that died from infectious diseases, neoplasia and emaciation contained higher concentrations of DDTs than those that died from trauma.

  5. In vivo measurements of the internal pH of Hediste (Nereis) diversicolor (Annelida, Polychaeta) exposed to ambient sulphidic conditions using pH microelectrodes

    NASA Astrophysics Data System (ADS)

    Sommer, Stefan; Jahn, Andreas; Funke, Friederike; Brenke, Nils

    The effect of different ambient sulphide concentrations on the internal pH regime of Hediste (Nereis) diversicolor was studied under in vivo conditions using liquid membrane pH microelectrodes, a method which is new to marine sciences. As a case study, the hypothesis was tested whether organisms exposed to ambient sulphidic conditions are able to lower their internal pH which, in effect, would reduce sulphide influx into the animals and thus could represent an effective detoxification mechanism. It was shown that a significant lowering of the internal pH occurred within only 20min after adding sulphide. This pH lowering appeared to be dependent on the external sulphide concentration of the ambient medium and showed a saturation beyond a threshold level of about 130μM. It is discussed whether this sulphide-induced pH drop is an active regulatory mechanism and acts as an effective protection mechanism against sulphide during short-term exposures.

  6. Dual congenital transmission of Toxoplasma gondii and Sarcocystis neurona in a late-term aborted pup from a chronically infected southern sea otter (Enhydra lutris nereis).

    PubMed

    Shapiro, Karen; Miller, Melissa A; Packham, Andrea E; Aguilar, Beatriz; Conrad, Patricia A; Vanwormer, Elizabeth; Murray, Michael J

    2016-03-01

    Toxoplasma gondii and Sarcocystis neurona are protozoan parasites with terrestrial definitive hosts, and both pathogens can cause fatal disease in a wide range of marine animals. Close monitoring of threatened southern sea otters (Enhydra lutris nereis) in California allowed for the diagnosis of dual transplacental transmission of T. gondii and S. neurona in a wild female otter that was chronically infected with both parasites. Congenital infection resulted in late-term abortion due to disseminated toxoplasmosis. Toxoplasma gondii and S. neurona DNA was amplified from placental tissue culture, as well as from fetal lung tissue. Molecular characterization of T. gondii revealed a Type X genotype in isolates derived from placenta and fetal brain, as well as in all tested fetal organs (brain, lung, spleen, liver and thymus). This report provides the first evidence for transplacental transmission of T. gondii in a chronically infected wild sea otter, and the first molecular and immunohistochemical confirmation of concurrent transplacental transmission of T. gondii and S. neurona in any species. Repeated fetal and/or neonatal losses in the sea otter dam also suggested that T. gondii has the potential to reduce fecundity in chronically infected marine mammals through parasite recrudescence and repeated fetal infection.

  7. Ontogeny of Oxygen Storage Capacity and Diving Ability in the Southern Sea Otter (Enhydra lutris nereis): Costs and Benefits of Large Lungs.

    PubMed

    Thometz, Nicole M; Murray, Michael J; Williams, Terrie M

    2015-01-01

    Small body size, large lungs, and dense pelage contribute to the unique challenges faced by diving sea otters (Enhydra lutris) when compared to other marine mammals. Here we determine the consequences of large lungs on the development of diving ability in southern sea otters (Enhydra lutris nereis) by examining the ontogeny of blood, muscle, and lung oxygen stores and calculating aerobic dive limits (cADL) for immature and mature age classes. Total oxygen storage capacity matures rapidly in sea otters, reaching adult levels by 2 mo postpartum. But this result is driven by exceptional lung capacity at birth, followed by a decrease in mass-specific lung volume with age. Blood and muscle oxygen stores remain well below adult values before weaning, with large pups exhibiting 74% and 54% of adult values, respectively. Slow muscle development limits the capacity of immature sea otters to dive against high positive buoyancy due to comparatively large lungs. Immature sea otters diving with total lung capacity (TLC) experience up to twice the mass-specific positive buoyancy as adults diving with TLC but can reduce these forces to comparable adult levels by using a smaller diving lung volume (DLV). The cADL of a juvenile with DLV is 3.62 min, while the cADL of an adult with TLC is 4.82 min. We find that the magnitude of positive buoyancy experienced by sea otters changes markedly with age and strongly influences the ontogeny of diving ability in this species. PMID:25860829

  8. Oral papillomatosis caused by Enhydra lutris papillomavirus 1 (ElPV-1) in southern sea otters (Enhydra lutris nereis) in California, USA.

    PubMed

    Ng, Terry Fei Fan; Miller, Melissa A; Kondov, Nikola O; Dodd, Erin M; Batac, Francesca; Manzer, Mike; Ives, Sarah; Saliki, Jeremiah T; Deng, Xutao; Delwart, Eric

    2015-04-01

    The southern sea otter (Enhydra lutris nereis) is a threatened marine sentinel. During postmortem investigations of stranded sea otters from 2004 to 2013 in California, US, papillomas were detected in the oral cavity of at least seven otters via necropsy and histopathology. Next-generation sequencing of viral particles purified from a single papilloma revealed a novel papillomavirus, Enhydra lutris papillomavirus 1 (ElPV-1). The genome of ElPV-1 was obtained, representing the first fully sequenced viral genome from southern sea otters. Phylogenetic analysis of the entire L1 gene, as well as a concatenated protein identities plot of all papillomaviral genes revealed that ElPV-1 is a λ-papillomavirus, related to a raccoon papillomavirus (Procyon lotor papillomavirus type 1) and a canine oral papillomavirus. Immunohistochemical staining, using a cross-reactive bovine papillomavirus antibody, suggested that ElPV-1 is present in intranuclear inclusions and intracytoplasmic keratin granules. Virus-infected cells were scattered throughout the stratum granulosum and stratum spinosum of the gingival and buccal papillomas. Using ElPV-1-specific PCR, we confirmed viral DNA in oral papillomas from all seven stranded sea otters, with identical L1 sequences. This virus is associated with the development of oral papillomatosis in southern sea otters. PMID:25647597

  9. Dual congenital transmission of Toxoplasma gondii and Sarcocystis neurona in a late-term aborted pup from a chronically infected southern sea otter (Enhydra lutris nereis).

    PubMed

    Shapiro, Karen; Miller, Melissa A; Packham, Andrea E; Aguilar, Beatriz; Conrad, Patricia A; Vanwormer, Elizabeth; Murray, Michael J

    2016-03-01

    Toxoplasma gondii and Sarcocystis neurona are protozoan parasites with terrestrial definitive hosts, and both pathogens can cause fatal disease in a wide range of marine animals. Close monitoring of threatened southern sea otters (Enhydra lutris nereis) in California allowed for the diagnosis of dual transplacental transmission of T. gondii and S. neurona in a wild female otter that was chronically infected with both parasites. Congenital infection resulted in late-term abortion due to disseminated toxoplasmosis. Toxoplasma gondii and S. neurona DNA was amplified from placental tissue culture, as well as from fetal lung tissue. Molecular characterization of T. gondii revealed a Type X genotype in isolates derived from placenta and fetal brain, as well as in all tested fetal organs (brain, lung, spleen, liver and thymus). This report provides the first evidence for transplacental transmission of T. gondii in a chronically infected wild sea otter, and the first molecular and immunohistochemical confirmation of concurrent transplacental transmission of T. gondii and S. neurona in any species. Repeated fetal and/or neonatal losses in the sea otter dam also suggested that T. gondii has the potential to reduce fecundity in chronically infected marine mammals through parasite recrudescence and repeated fetal infection. PMID:26494610

  10. Diversity of Cultivated Fungi Associated with Conventional and Transgenic Sugarcane and the Interaction between Endophytic Trichoderma virens and the Host Plant.

    PubMed

    Romão-Dumaresq, Aline Silva; Dourado, Manuella Nóbrega; Fávaro, Léia Cecilia de Lima; Mendes, Rodrigo; Ferreira, Anderson; Araújo, Welington Luiz

    2016-01-01

    Plant-associated fungi are considered a vast source for biotechnological processes whose potential has been poorly explored. The interactions and diversity of sugarcane, one of the most important crops in Brazil, have been rarely studied, mainly concerning fungal communities and their interactions with transgenic plants. Taking this into consideration, the purpose of this study was, based on culture dependent strategy, to determine the structure and diversity of the fungal community (root endophytes and rhizosphere) associated with two varieties of sugarcane, a non-genetically modified (SP80-1842) variety and its genetically modified counterpart (IMI-1, expressing imazapyr herbicide resistance). For this, the sugarcane varieties were evaluated in three sampling times (3, 10 and 17 months after planting) under two crop management (weeding and herbicide treatments). In addition, a strain of Trichoderma virens, an endophyte isolated from sugarcane with great potential as a biological control, growth promotion and enzyme production agent, was selected for the fungal-plant interaction assays. The results of the isolation, characterization and evaluation of fungal community changes showed that the sugarcane fungal community is composed of at least 35 different genera, mostly in the phylum Ascomycota. Many genera are observed at very low frequencies among a few most abundant genera, some of which were isolated from specific plant sites (e.g., the roots or the rhizosphere). An assessment of the possible effects upon the fungal community showed that the plant growth stage was the only factor that significantly affected the community's structure. Moreover, if transgenic effects are present, they may be minor compared to other natural sources of variation. The results of interaction studies using the Green fluorescent protein (GFP)-expressing T. virens strain T.v.223 revealed that this fungus did not promote any phenotypic changes in the host plant and was found mostly in the

  11. Diversity of Cultivated Fungi Associated with Conventional and Transgenic Sugarcane and the Interaction between Endophytic Trichoderma virens and the Host Plant

    PubMed Central

    Romão-Dumaresq, Aline Silva; Dourado, Manuella Nóbrega; Fávaro, Léia Cecilia de Lima; Mendes, Rodrigo; Ferreira, Anderson; Araújo, Welington Luiz

    2016-01-01

    Plant-associated fungi are considered a vast source for biotechnological processes whose potential has been poorly explored. The interactions and diversity of sugarcane, one of the most important crops in Brazil, have been rarely studied, mainly concerning fungal communities and their interactions with transgenic plants. Taking this into consideration, the purpose of this study was, based on culture dependent strategy, to determine the structure and diversity of the fungal community (root endophytes and rhizosphere) associated with two varieties of sugarcane, a non-genetically modified (SP80-1842) variety and its genetically modified counterpart (IMI-1, expressing imazapyr herbicide resistance). For this, the sugarcane varieties were evaluated in three sampling times (3, 10 and 17 months after planting) under two crop management (weeding and herbicide treatments). In addition, a strain of Trichoderma virens, an endophyte isolated from sugarcane with great potential as a biological control, growth promotion and enzyme production agent, was selected for the fungal-plant interaction assays. The results of the isolation, characterization and evaluation of fungal community changes showed that the sugarcane fungal community is composed of at least 35 different genera, mostly in the phylum Ascomycota. Many genera are observed at very low frequencies among a few most abundant genera, some of which were isolated from specific plant sites (e.g., the roots or the rhizosphere). An assessment of the possible effects upon the fungal community showed that the plant growth stage was the only factor that significantly affected the community’s structure. Moreover, if transgenic effects are present, they may be minor compared to other natural sources of variation. The results of interaction studies using the Green fluorescent protein (GFP)-expressing T. virens strain T.v.223 revealed that this fungus did not promote any phenotypic changes in the host plant and was found mostly in

  12. Diversity of Cultivated Fungi Associated with Conventional and Transgenic Sugarcane and the Interaction between Endophytic Trichoderma virens and the Host Plant.

    PubMed

    Romão-Dumaresq, Aline Silva; Dourado, Manuella Nóbrega; Fávaro, Léia Cecilia de Lima; Mendes, Rodrigo; Ferreira, Anderson; Araújo, Welington Luiz

    2016-01-01

    Plant-associated fungi are considered a vast source for biotechnological processes whose potential has been poorly explored. The interactions and diversity of sugarcane, one of the most important crops in Brazil, have been rarely studied, mainly concerning fungal communities and their interactions with transgenic plants. Taking this into consideration, the purpose of this study was, based on culture dependent strategy, to determine the structure and diversity of the fungal community (root endophytes and rhizosphere) associated with two varieties of sugarcane, a non-genetically modified (SP80-1842) variety and its genetically modified counterpart (IMI-1, expressing imazapyr herbicide resistance). For this, the sugarcane varieties were evaluated in three sampling times (3, 10 and 17 months after planting) under two crop management (weeding and herbicide treatments). In addition, a strain of Trichoderma virens, an endophyte isolated from sugarcane with great potential as a biological control, growth promotion and enzyme production agent, was selected for the fungal-plant interaction assays. The results of the isolation, characterization and evaluation of fungal community changes showed that the sugarcane fungal community is composed of at least 35 different genera, mostly in the phylum Ascomycota. Many genera are observed at very low frequencies among a few most abundant genera, some of which were isolated from specific plant sites (e.g., the roots or the rhizosphere). An assessment of the possible effects upon the fungal community showed that the plant growth stage was the only factor that significantly affected the community's structure. Moreover, if transgenic effects are present, they may be minor compared to other natural sources of variation. The results of interaction studies using the Green fluorescent protein (GFP)-expressing T. virens strain T.v.223 revealed that this fungus did not promote any phenotypic changes in the host plant and was found mostly in the

  13. Pollution effects on biochemical pathways determined in the polychaete Hediste diversicolor collected in three Portuguese estuaries.

    PubMed

    Nunes, B; Vidal, D; Barbosa, I; Soares, A M V M; Freitas, R

    2016-09-14

    Biomonitoring is an important tool for the assessment of the quality and functions of ecosystems, providing information about the pollutants present and the direct effects that they exert on organisms. Biomonitoring relies upon the quantification of variables that can be biochemical, genetic, morphological and physiological changes. Such variables are designated as biomarkers, and multiple biomarkers are usually determined simultaneously in order to have a more integrated analysis and information about sublethal early effects of contaminants. In this work, we quantified biomarkers, associated with oxidative stress (glutathione-S-transferases GSTs, and catalase CAT, activities; levels of peroxidative alterations, by the thiobarbituric acid reactive substances assay, TBARS) and neurotoxicity (acetylcholinesterase activity, AChE) in the polychaete Hediste diversicolor. Organisms were collected at three distinct estuaries, Ria de Aveiro (Laranjo and São Jacinto), Douro River (São Paio, Afurada, and Ribeira da Granja), both impacted by human activities, and Minho River (Seixas), which has been used as a reference site. Obtained data showed the occurrence of anti-oxidant responses, in most samples from contaminated sites, which was not followed however by the occurrence of oxidative damage in organisms from Ria de Aveiro. None of the analyzed organisms had significant impairment of cholinesterasic activity, suggesting the absence of a prior exposure to neurotoxic compounds. In fact, organisms collected at Ria de Aveiro had largely increased AChE activity, suggesting an uncommon paradoxical biological response that is further discussed. PMID:27499386

  14. Multiple life stage sensitivity of a deposit-feeding polychaete to chemical toxicants in sediment

    SciTech Connect

    Rice, C.A.; Sibley, T.; Ylitalo, G.M.; Casillas, E.

    1995-12-31

    By focusing on acute toxicity in species with habitat and food preferences often quite different from the environments of primary interest; that is, the depositional, fine-grained, organically enriched benthos, standard methods of testing sediment toxicity using single species have important problems of relevance in terms of test endpoints and target species. This study addresses these issues by building a set of baseline toxicity data that emphasizes critical life stage sensitivity over a wide range of toxicant concentrations in long-term sediment exposures for an animal with a model life history. The opportunistic, deposit-feeding polychaete Armandia brevis was exposed to sediments supplemented with fluoranthene, cadmium, copper, lead, and mercury, alone and in a model mixture, for 60 days. Mortality and emergence from sediment were recorded daily, and growth and maturity were measured at 20, 40, and 60d. To measure recruitment, cultured larvae were presented with the same sediments and allowed to settle and complete metamorphosis. Differential endpoint sensitivity, and differential chemical toxicity were evaluated. In addition, sediment and tissue concentrations of organic toxicants were used to link toxic responses to body burdens, and to consider the role of benthic infauna as contaminant vectors in the marine environment.

  15. Temporal dynamics in the diet of two marine polychaetes as inferred from fatty acid biomarkers

    NASA Astrophysics Data System (ADS)

    Braeckman, Ulrike; Provoost, Pieter; Sabbe, Koen; Soetaert, Karline; Middelburg, Jack J.; Vincx, Magda; Vanaverbeke, Jan

    2012-02-01

    We investigated the temporal variation of pelagic and benthic food sources in the diet of two marine polychaetes: a macrobenthic omnivore (Nephtys hombergii) and a suspension-deposit feeder (Lanice conchilega) by means of fatty acid (FA) biomarkers and compound-specific stable isotope analysis (CSIA). FA biomarkers in the suspended particulate matter roughly mirrored phytoplankton dynamics in the water column, consisting of a small diatom dominance early spring, succeeded by a mass Phaeocystis peak followed by a mixed diatom-dinoflagellate bloom. Deposition and subsequent bacterial degradation of the phytoplankton bloom were also reflected in sediment FA biomarkers. The main distinction in FA biomarker concentration within macrobenthic tissue was observed at the species level (48% of variation), the diet of L. conchilega consisting of bacteria and diatoms and that of N. hombergii also of diatoms, but including more dinoflagellates and invertebrates. Temporal variation explained 17%: the two species retained more bacterial and Phaeocystis markers before the bloom, while they accumulated more poly-unsaturated FA after the bloom. CSIA revealed increased accumulation or biosynthesis of poly-unsaturated FA from the suspended matter in L. conchilega upon bloom deposition, which is probably related to energy storage for gametogenesis. In contrast, bloom-dependent accumulation or biosynthesis of FA was not detected in N. hombergii, probably because of its reliance on invertebrate prey.

  16. Proteomic Changes Associated with Successive Reproductive Periods in Male Polychaetous Neanthes arenaceodentata

    PubMed Central

    Chandramouli, Kondethimmanahalli H.; Reish, Donald; Zhang, Huoming; Qian, Pei-Yuan; Ravasi, Timothy

    2015-01-01

    The polychaetous annelid Neanthes acuminata complex has a widespread distribution, with the California population referred to as N. arenaceodentata. The reproductive pattern in this complex is unique, in that the female reproduces once and then dies, whereas the male can reproduce up to nine times. The male incubates the embryos until the larvae leave the male’s tube 21–28 days later and commences feeding. Reproductive success and protein expression patterns were measured over the nine reproductive periods. The percent success of the male in producing juveniles increased during the first three reproductive periods and then decreased, but the number of juveniles produced was similar through all nine periods. iTRAQ based quantitative proteomics were used to analyze the dynamics of protein expression patterns. The expression patterns of several proteins were found to be altered. The abundant expression of muscular and contractile proteins may have affected body weight and reproductive success. Sperm have never been observed; fertilization occurs within the parent’s tube. Proteins associated with sperm maturation and fertilization were identified, including ATPase, clathrin, peroxiredoxins and enolase, which may provide clues to the molecular mechanisms enabling males to reproduce multiple times. PMID:26337980

  17. Sublethal predation and regeneration in two onuphid polychaetes: patterns and implications.

    PubMed

    Berke, Sarah K; Cruz, Veronica; Osman, Richard W

    2009-12-01

    We examined sublethal predation in the polychaete Diopatra cuprea, an important ecosystem engineer of intertidal and shallow subtidal marine sediments in the western Atlantic. D. cuprea commonly loses its antennae and portions of its anterior to predator attacks; these lost body portions are subsequently regenerated. We asked (i) if the intensity of sublethal predation differs for D. cuprea populations in Virginia versus Florida, (ii) if sublethal predation varies temporally in each region, and (iii) if sublethal predation influences activity and tube-building rates. Within Florida, we also drew comparisons between D. cuprea and the closely related onuphid Americonuphis magna. Surprisingly, we found that sublethal predation is more intense in Virginia than in Florida, likely making substantial contributions to secondary productivity. Within Florida, A. magna experienced more antennal loss than D. cuprea and is incapable of anterior regeneration. D. cuprea activity and tube-building rates are strongly influenced by anterior loss, but more subtly influenced by antennal loss. Given the observed rates of sublethal predation and population densities in Virginia versus Florida, sublethal predation is an important factor influencing D. cuprea populations and their associated communities. PMID:20040749

  18. Physiological and biochemical responses of the Polychaete Diopatra neapolitana to organic matter enrichment.

    PubMed

    Carregosa, Vanessa; Velez, Cátia; Pires, Adília; Soares, Amadeu M V M; Figueira, Etelvina; Freitas, Rosa

    2014-10-01

    Several studies have demonstrated that organic matter enrichment may be associated to aquaculture, leading to impoverished benthic communities and species succession with loss of biodiversity, but very few studies have investigated biochemical and physiological alterations that species affected by aquaculture activities undergo. Thus, in the present study, the effects of the organic enrichment originating from an oyster culture were studied in the Polychaete Diopatra neapolitana, a species already shown to be sensitive to inorganic contamination. For this, physiological responses and biochemical alterations were evaluated. The results obtained revealed that individuals from highly organically enriched areas presented lower capacity to regenerate their body but higher glycogen and protein levels. Furthermore, with increasing organic matter D. neapolitana increased the lipid peroxidation (LPO), the oxidized glutathione content (GSSG) and Glutathione S-transferase activity (GSTs) content, and the activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD). This study evidenced that organic matter enrichment induced biochemical and physiological alterations in D. neapolitana. Thus, this species was shown to be a good sentinel species to monitor organic contamination. PMID:24973779

  19. Activation of Hox genes during caudal regeneration of the polychaete annelid Platynereis dumerilii.

    PubMed

    Pfeifer, Kathrin; Dorresteijn, Adriaan W C; Fröbius, Andreas C

    2012-05-01

    The capability of regenerating posterior segments and pygidial structures is ancestral for annelids and has been lost only a few times within this phylum. As one of the three major segmented taxa, annelids enable us to monitor reconstruction of lost tissues and organs. During regeneration, regional identities have to be imprinted onto the newly formed segments. In this study, we show spatial and temporal localization of expression of nine Hox genes during caudal regeneration of the polychaete annelid Platynereis dumerilii. Hox genes are homeodomain genes encoding transcriptional regulators of axial patterning in bilaterian animals during development. We demonstrate that five Platynereis Hox genes belonging to paralog groups (PG) 1, 4, 5, 6, and 9-14 are expressed in domains of the regenerating nervous system consistent with providing positional information along the anteroposterior axis of the regenerate. We report that expression in regenerating neuromeres is limited to varying subsets of perikarya, called gangliosomes. Four of nine genes analyzed do not appear to be involved in axial patterning. Two genes, Pdu-Hox2 and Pdu-Hox3, are predominantly expressed in the growth zone region. For some Hox genes expression in newly formed coelomic epithelia can be observed. Platynereis Hox genes do not exhibit temporal or spatial colinearity. Although there are some similarities to previously reported expression patterns during larval and postlarval development in Nereididae (Kulakova et al. 2007), expression patterns observed during caudal regeneration also show unique patterns. PMID:22569931

  20. The dynamics of alkaline phosphatase activity during operculum regeneration in the polychaete Pomatoceros lamarckii.

    PubMed

    Szabó, Réka; Ferrier, David E K

    2014-01-01

    Alkaline phosphatase enzymes are found throughout the living world and fulfil a variety of functions. They have been linked to regeneration, stem cells and biomineralisation in a range of animals. Here we describe the pattern of alkaline phosphatase activity in a spiralian appendage, the operculum of the serpulid polychaete Pomatoceros lamarckii. The P. lamarckii operculum is reinforced by a calcified opercular plate and is capable of rapid regeneration, making it an ideal model system to study these key processes in annelids. Alkaline phosphatase activity is present in mesodermal tissues of both intact and regenerating opercular filaments, in a strongly regionalised pattern correlated with major morphological features. Based on the lack of epidermal activity and the broad distribution of staining in mesodermal tissues, calcification- or stem cell-specific roles are unlikely. Transcriptomic data reveal that at least four distinct genes contribute to the detected activity. Opercular alkaline phosphatase activity is sensitive to levamisole. Phylogenetic analysis of metazoan alkaline phosphatases indicates homology of the P. lamarckii sequences to other annelid alkaline phosphatases, and shows that metazoan alkaline phosphatase evolution was characterised by extensive lineage-specific duplications. PMID:25690977

  1. Toxic and adaptive resonses to copper by the sabellid polychaete, Eudistylia vancouveri

    SciTech Connect

    Young, J.S.

    1981-10-01

    Experiments with copper and the sabellid polychaete, Eudistylia vancouveri, demonstrated the following: (1) background copper in the general body and branchial crown was 5.0 and 8.5 ..mu..g Cu/g dry wt, respectively. The concentration factors for copper in the branchial crown range from 38 to 68. (2) The threshold concentration for increased copper accumulation was between 3 and 6 ..mu..g/l total copper. (3) In copper treatments greater than or equal to 8 ..mu..g Cu/l, the radioles of the branchial crown were chemically injured. (4) X-ray microanalysis and staining techniques showed that copper was localized in lysosomes. Lysosomal sequestering of heavy metals is considered an initial detoxifying mechanism, but metals may also cause labilization of the lysosomes and release of their hydrolytic enzymes, resulting in autolysis. (5) The branchial crown regenerated even though the worms were still being exposed to copper. With the first observed signs of regeneration was the attending induction of a copper-binding protein. This phenmenon was interpreted as strong evidence in support of the theory that metal-binding proteins aid in metal detoxification. (ERB)

  2. Patterns of nuclear genetic variation in the poecilogonous polychaete Streblospio benedicti.

    PubMed

    Rockman, Matthew V

    2012-07-01

    The evolution of marine larvae is replete with transitions in trophic mode, but little is known about how, at the genetic level, these transitions are achieved. Basic parameters, including the number of underlying loci, their molecular characteristics, and the population-genetic processes that drive transitions remain unknown. Streblospio benedicti, an abundant benthic polychaete with heritable poecilogony, provides a unique genetically tractable system for addressing these issues. Individuals of S. benedicti vary in diverse aspects of development. Some females produce small, planktotrophic larvae, whereas others produce large, yolky larvae capable of settling without feeding. Here, I present estimates of basic features of nuclear genetic variation in S. benedicti to lay the foundations for subsequent efforts to understand the genetic basis of poecilogony. Sequence of ∼20 kb of random nuclear DNA indicates that the nucleotide composition, at 62.1% A + T, is typical of lophotrochozoan genomes. Population-genetic data, acquired by sequencing two loci (∼2500 bp) in multiple animals of each developmental morph, indicate that the morphs exhibit very little differentiation at random loci. Nucleotide heterozygosity (θπ) is ∼0.5-1% per site, and linkage disequilibrium decays within a few kilobases (ρ  ∼ 3 × 10(-3) per site). These data suggest that genetic mapping by association will require a high density of markers, but linkage mapping and identification of regions of elevated inter-morph differentiation hold great promise. PMID:22659203

  3. Proteomic Changes Associated with Successive Reproductive Periods in Male Polychaetous Neanthes arenaceodentata.

    PubMed

    Chandramouli, Kondethimmanahalli H; Reish, Donald; Zhang, Huoming; Qian, Pei-Yuan; Ravasi, Timothy

    2015-01-01

    The polychaetous annelid Neanthes acuminata complex has a widespread distribution, with the California population referred to as N. arenaceodentata. The reproductive pattern in this complex is unique, in that the female reproduces once and then dies, whereas the male can reproduce up to nine times. The male incubates the embryos until the larvae leave the male's tube 21-28 days later and commences feeding. Reproductive success and protein expression patterns were measured over the nine reproductive periods. The percent success of the male in producing juveniles increased during the first three reproductive periods and then decreased, but the number of juveniles produced was similar through all nine periods. iTRAQ based quantitative proteomics were used to analyze the dynamics of protein expression patterns. The expression patterns of several proteins were found to be altered. The abundant expression of muscular and contractile proteins may have affected body weight and reproductive success. Sperm have never been observed; fertilization occurs within the parent's tube. Proteins associated with sperm maturation and fertilization were identified, including ATPase, clathrin, peroxiredoxins and enolase, which may provide clues to the molecular mechanisms enabling males to reproduce multiple times. PMID:26337980

  4. Expression pattern of arenicins—the antimicrobial peptides of polychaete Arenicola marina

    PubMed Central

    Maltseva, Arina L.; Kotenko, Olga N.; Kokryakov, Vladimir N.; Starunov, Viktor V.; Krasnodembskaya, Anna D.

    2014-01-01

    Immune responses of invertebrate animals are mediated through innate mechanisms, among which production of antimicrobial peptides play an important role. Although evolutionary Polychaetes represent an interesting group closely related to a putative common ancestor of other coelomates, their immune mechanisms still remain scarcely investigated. Previously our group has identified arenicins—new antimicrobial peptides of the lugworm Arenicola marina, since then these peptides were thoroughly characterized in terms of their structure and inhibitory potential. In the present study we addressed the question of the physiological functions of arenicins in the lugworm body. Using molecular and immunocytochemical methods we demonstrated that arencins are expressed in the wide range of the lugworm tissues—coelomocytes, body wall, extravasal tissue and the gut. The expression of arenicins is constitutive and does not depend on stimulation of various infectious stimuli. Most intensively arenicins are produced by mature coelomocytes where they function as killing agents inside the phagolysosome. In the gut and the body wall epithelia arenicins are released from producing cells via secretion as they are found both inside the epithelial cells and in the contents of the cuticle. Collectively our study showed that arenicins are found in different body compartments responsible for providing a first line of defense against infections, which implies their important role as key components of both epithelial and systemic branches of host defense. PMID:25566093

  5. Tube epifauna of the Polychaete Phyllochaetopterus socialisClaparède

    NASA Astrophysics Data System (ADS)

    Nalesso, Rosebel Cunha; Duarte, Luíz. Francisco L.; Pierozzi, Ivo, Jr.; Enumo, Eloisa Fiorim

    1995-07-01

    Animals greater than 1 mm, found among tangled tubes of Phyllochaetopterus socialis(Chaetopteridae) from Araçá Beach, São Sebastião district, Brazil, were studied for 1 year, with four samples in each of four seasons. They comprised 10 338 individuals in 1722·7 g dry weight of polychaete tubes, with Echinodermata, Polychaeta (not identified to species) and Crustacea as the dominant taxa. The Shannon-Wiener diversity index did not vary seasonally, only two species (a holothurian and a pycnogonid) showing seasonal variation. Ophiactis savignyiwas the dominant species, providing 45·5% of individuals. Three other ophiuroids, the holothurian Synaptula hidriformis, the crustaceans Leptochelia savignyi, Megalobrachium soriatumand Synalpheus fritzmuelleri, the sipunculan Themiste alutaceaand the bivalve Hiatella arcticawere all abundant, but most of the 68 species recorded occurred sparsely. The assemblage associated with P. socialiswas similar to the endofauna of the sponge Zygomycale parishiiand the bryozoan Schizoporella unicornis, and to the epifauna of seaweed Sargassum cymosum, all of which occurred nearby.

  6. Chronic toxicity of 2,4,6-trinitrotoluene to a marine polychaete and an estuarine amphipod

    SciTech Connect

    Green, A.; Moore, D.; Farrar, D.

    1999-08-01

    The chronic toxicity of sediment-associated 2,4,6-trinitrotoluene (TNT) to the marine polychaete Neanthes arenaceodentata and the estuarine amphipod Leptocheirus plumulosus was evaluated. Test organisms were exposed to sediments spiked with radiolabeled TNT for 28 d, after which time the endpoints of mortality, growth, and reproduction (L. plumulosus only) were assayed and compared against the TNT tissue concentrations as well as the TNT sediment concentrations. Survival was significantly reduced at a tissue concentration of 61 {micro}g TNT/g wet wt tissue in N. arenaceodentata and L. plumulosus with enhancement (significant for N. arenaceodentata) occurring at the lower TNT concentrations. Growth was significantly reduced at the highest TNT exposure of 10.0 {micro}g TNT/g wet wt tissue in L. plumulosus. Reproduction was significantly reduced at a tissue concentration of 6.3 {micro}g TNT/g wet wt tissue in L. plumulosus. The results of this study demonstrate that both N. arenaceodentata and L. plumulosus are sensitive to the presence of sediment-associated TNT and that more information is needed about the toxicity of TNT to benthic fauna to facilitate risk assessment and management of TNT-contaminated sites.

  7. Effects of low seawater pH on the marine polychaete Platynereis dumerilii.

    PubMed

    Wäge, Janine; Hardege, Jörg D; Larsson, Tomas A; Simakov, Oleg; Chapman, Emma C; Arendt, Detlev; Rotchell, Jeanette M

    2015-06-15

    An important priority for any organism is to maintain internal cellular homeostasis including acid-base balance. Yet, the molecular level impacts of changing environmental conditions, such as low pH, remain uncharacterised. Herein, we isolate partial Na(+)/H(+)exchangers (NHE), carbonic anhydrase (CA), and calmodulin (CaM) genes from a polychaete, Platynereis dumerilii and investigate their relative expression in acidified seawater conditions. mRNA expression of NHE was significantly down-regulated after 1h and up-regulated after 7days under low pH treatment (pH 7.8), indicating changes in acid-base transport. Furthermore, the localisation of NHE expression was also altered. A trend of down regulation in CA after 1h was also observed, suggesting a shift in the CO2 and HCO3(-) balance. No change in CaM expression was detected after 7days exposure to acidified seawater. This study provides insight into the molecular level changes taking place following exposure to acidified seawater in a non-calcifying, ubiquitous, organism. PMID:25913791

  8. Expression of an endochitinase gene from Trichoderma virens confers enhanced tolerance to Alternaria blight in transgenic Brassica juncea (L.) czern and coss lines.

    PubMed

    Kamble, Suchita; Mukherjee, Prasun K; Eapen, Susan

    2016-01-01

    An endochitinase gene 'ech42' from the biocontrol fungus 'Trichoderma virens' was introduced to Brassica juncea (L). Czern and Coss via Agrobaterium tumefaciens mediated genetic transformation method. Integration and expression of the 'ech42' gene in transgenic lines were confirmed by PCR, RT-PCR and Southern hybridization. Transgenic lines (T1) showed expected 3:1 Mendelian segregation ratio when segregation analysis for inheritance of transgene 'hpt' was carried out. Fluorimetric analysis of transgenic lines (T0 and T1) showed 7 fold higher endochitinase activity than the non-transformed plant. Fluorimetric zymogram showed presence of endochitinase (42 kDa) in crude protein extract of transgenic lines. In detached leaf bioassay with fungi Alternaria brassicae and Alternaria brassicicola, transgenic lines (T0 and T1) showed delayed onset of lesions as well as 30-73 % reduction in infected leaf area compared to non-transformed plant. PMID:27186020

  9. Role of two G-protein alpha subunits, TgaA and TgaB, in the antagonism of plant pathogens by Trichoderma virens.

    PubMed

    Mukherjee, Prasun K; Latha, Jagannathan; Hadar, Ruthi; Horwitz, Benjamin A

    2004-01-01

    G-protein alpha subunits are involved in transmission of signals for development, pathogenicity, and secondary metabolism in plant pathogenic and saprophytic fungi. We cloned two G-protein alpha subunit genes, tgaA and tgaB, from the biocontrol fungus Trichoderma virens. tgaA belongs to the fungal Galphai class, while tgaB belongs to the class defined by gna-2 of Neurospora crassa. We compared loss-of-function mutants of tgaA and tgaB with the wild type for radial growth, conidiation, germination of conidia, the ability to overgrow colonies of Rhizoctonia solani and Sclerotium rolfsii in confrontation assays, and the ability to colonize the sclerotia of these pathogens in soil. Both mutants grew as well as the wild type, sporulated normally, did not sporulate in the dark, and responded to blue light by forming a conidial ring. The tgaA mutants germinated by straight unbranched germ tubes, while tgaB mutants, like the wild type, germinated by wavy and highly branched germ tubes. In confrontation assays, both tgaA and tgaB mutants and the wild type overgrew, coiled, and lysed the mycelia of R. solani, but tgaA mutants had reduced ability to colonize S. rolfsii colonies. In the soil plate assay, both mutants parasitized the sclerotia of R. solani, but tgaA mutants were unable to parasitize the sclerotia of S. rolfsii. Thus, tgaA is involved in antagonism against S. rolfsii, but neither G protein subunit is involved in antagonism against R. solani. T. virens, which has a wide host range, thus employs a G-protein pathway in a host-specific manner. PMID:14711686

  10. Repression of Tropolone Production and Induction of a Burkholderia plantarii Pseudo-Biofilm by Carot-4-en-9,10-diol, a Cell-to-Cell Signaling Disrupter Produced by Trichoderma virens

    PubMed Central

    Wang, Mengcen; Hashimoto, Makoto; Hashidoko, Yasuyuki

    2013-01-01

    Background The tropolone-tolerant Trichoderma virens PS1-7 is a biocontrol agent against Burkholderia plantarii, causative of rice seedling blight. When exposed to catechol, this fungus dose-dependently produced carot-4-en-9,10-diol, a sesquiterpene-type autoregulatory signal molecule that promotes self-conidiation of T. virens PS1-7 mycelia. It was, however, uncertain why T. virens PS1-7 attenuates the symptom development of the rice seedlings infested with B. plantarii. Methodology/Principal Findings To reveal the antagonism by T. virens PS1-7 against B. plantarii leading to repression of tropolone production in a coculture system, bioassay-guided screening for active compounds from a 3-d culture of T. virens PS1-7 was conducted. As a result, carot-4-en-9,10-diol was identified and found to repress tropolone production of B. plantarii from 10 to 200 µM in a dose-dependent manner as well as attenuate virulence of B. plantarii on rice seedlings. Quantitative RT-PCR analysis revealed that transcriptional suppression of N-acyl-L-homoserine lactone synthase plaI in B. plantarii was the main mode of action by which carot-4-en-9,10-diol mediated the quorum quenching responsible for repression of tropolone production. In addition, the unique response of B. plantarii to carot-4-en-9,10-diol in the biofilm formed in the static culture system was also found. Although the initial stage of B. plantarii biofilm formation was induced by both tropolone and carot-4-en-9,10-diol, it was induced in different states. Moreover, the B. plantarii biofilm that was induced by carot-4-en-9,10-diol at the late stage showed defects not only in matrix structure but also cell viability. Conclusions/Significance Our findings demonstrate that carot-4-en-9,10-diol released by T. virens PS1-7 acts as an interkingdom cell-to-cell signaling molecule against B. plantarii to repress tropolone production and induces pseudo-biofilm to the cells. This observation also led to another discovery that

  11. The biomagnification of PCBs, PCDDs, PCDFs in a simplified laboratory food chain

    SciTech Connect

    Taplin, B.; Pruell, R.; McGovern, D.; McKinney, R.

    1995-12-31

    The trophic transfer and biomagnification potential of polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs), were investigated in a simplified marine benthic food chain. Polychaetes, Nereis virens were exposed to contaminated sediment and fed to juvenile lobsters, Homarus americanus exposed to the same sediment for 112 days. Time series uptake and depuration measurements were made for lobster muscle and hepatopancreas. A nonlinear model (BIOFAC) was used to calculate uptake and depuration rate constants, bioaccumulation factors, and steady state concentrations for PCBs, PCDDs, and PCDFs. Biomagnification factors (BMFs), on a lipid weight basis, were calculated for both tissues. Lobsters accumulated PCDDs, PCDFs, and PCBs from contaminated sediment and food (polychaetes). Of the two tissues, lobster hepatopancreas, showed the highest concentrations for all compounds analyzed. Of the PCDDs and PCDFs studied, only 2,3,7,8-tetrachlorodibenzodioxin, 2,3,7,8-tetrachlorodibenzofuran, 2,3,4,7,8-pentachlorodibenzofuran, and 1,2,3,4,7,8-hexachlorodibenzofuran were detected in lobster muscle and hepatopancreas tissues. Of the PCB congeners studied, 2,2{prime},4,4{prime},5,5{prime} hexachlorobiphenyl reached the highest concentration in lobster muscle and hepatopancreas. Lobsters also accumulated non-ortho substituted PCBs in both tissues.

  12. A protozoal-associated epizootic impacting marine wildlife: Mass-mortality of southern sea otters (Enhydra lutris nereis) due to Sarcocystis neurona infection

    PubMed Central

    Conrad, Patricia A.; Harris, Michael; Hatfield, Brian; Langlois, Gregg; Jessup, David A.; Magargal, Spencer L.; Packham, Andrea E.; Toy-Choutka, Sharon; Melli, Ann C.; Murray, Michael A.; Gulland, Frances M.; Grigg, Michael E.

    2016-01-01

    During April, 2004, 40 sick and dead southern sea otters (Enhydra lutris nereis) were recovered over 18 km of coastline near Morro Bay, California. This event represented the single largest monthly spike in mortality ever recorded during 30 years of southern sea otter stranding data collection. Because of the point-source nature of the event and clinical signs consistent with severe, acute neurological disease, exposure to a chemical or marine toxin was initially considered. However, detailed postmortem examinations revealed lesions consistent with an infectious etiology, and further investigation confirmed the protozoan parasite Sarcocystis neurona as the underlying cause. Tissues from 94% of examined otters were PCR-positive for S. neurona, based on DNA amplification and sequencing at the ITS-1 locus, and 100% of tested animals (n = 14) had elevated IgM and IgG titers to S. neurona. Evidence to support the point-source character of this event include the striking spatial and temporal clustering of cases and detection of high concentrations of anti-S. neurona IgM in serum of stranded animals. Concurrent exposure to the marine biotoxin domoic acid may have enhanced susceptibility of affected otters to S. neurona and exacerbated the neurological signs exhibited by stranded animals. Other factors that may have contributed to the severity of this epizootic include a large rainstorm that preceded the event and an abundance of razor clams near local beaches, attracting numerous otters close to shore within the affected area. This is the first report of a localized epizootic in marine wildlife caused by apicomplexan protozoa. PMID:20615616

  13. The high cost of motherhood: End-lactation syndrome in southern sea otters (Enhydra lutris nereis) on the central California, USA, coast

    USGS Publications Warehouse

    Chinn, Sarah S; Miller, Melissa A.; Tinker, M. Tim; Staedler, Michelle M.; Batac, Francesca I.; Dodd, Erin M.; Henkel, Laird A.

    2016-01-01

    Sea otters (Enhydra lutris) have exceptionally high energetic requirements, which nearly double during lactation and pup care. Thus, females are extremely vulnerable to caloric insufficiency. Despite a number of compensatory strategies, the metabolic challenge of reproduction culminates in numerous maternal deaths annually. Massive depletion of energy reserves results in a case presentation that we define as end-lactation syndrome (ELS), characterized by moderate to severe emaciation not attributable to a concurrent, independent disease process in females dying during late pup care or postweaning. We compiled detailed data for 108 adult female southern sea otters (Enhydra lutris nereis) examined postmortem that stranded in California, US, 2005–12, and assessed pathology, reproductive status, and the location and timing of stranding. We introduce simple, grossly apparent, standardized physical criteria to assess reproductive stage for female sea otters. We also describe ELS, examine associated risk factors, and highlight female life history strategies that likely optimize reproduction and survival. Our data suggest that females can reset both the timing and energetic demands of reproduction through fetal loss, pup abandonment, or early weaning as part of specific physiologic checkpoints during each reproductive cycle. Females appear to preload nutritionally during delayed implantation and gestation to increase fitness and reproductive success. We found that ELS was a major cause of death, affecting 56% of enrolled adult females. Peak ELS prevalence occurred in late spring, possibly reflecting the population trend toward fall/winter pupping. Increasing age and number of pregnancies were associated with a higher risk of ELS. Although the proportion of ELS females was highest in areas with dense sea otter populations, cases were recovered throughout the range, suggesting that death from ELS is associated with, but not solely caused by, population resource limitation.

  14. A protozoal-associated epizootic impacting marine wildlife: Mass-mortality of southern sea otters (Enhydra lutris nereis) due to Sarcocystis neurona infection

    USGS Publications Warehouse

    Miller, M.A.; Conrad, P.A.; Harris, M.; Hatfield, B.; Langlois, G.; Jessup, David A.; Magargal, S.L.; Packham, A.E.; Toy-Choutka, S.; Melli, A.C.; Murray, M.A.; Gulland, F.M.; Grigg, M.E.

    2010-01-01

    During April 2004, 40 sick and dead southern sea otters (Enhydra lutris nereis) were recovered over 18 km of coastline near Morro Bay, California. This event represented the single largest monthly spike in mortality ever recorded during 30 years of southern sea otter stranding data collection. Because of the point-source nature of the event and clinical signs consistent with severe, acute neurological disease, exposure to a chemical or marine toxin was initially considered. However, detailed postmortem examinations revealed lesions consistent with an infectious etiology, and further investigation confirmed the protozoan parasite Sarcocystis neurona as the underlying cause. Tissues from 94% of examined otters were PCR-positive for S. neurona, based on DNA amplification and sequencing at the ITS-1 locus, and 100% of tested animals (n= 14) had elevated IgM and IgG titers to S. neurona. Evidence to support the point-source character of this event include the striking spatial and temporal clustering of cases and detection of high concentrations of anti- S. neurona IgM in serum of stranded animals. Concurrent exposure to the marine biotoxin domoic acid may have enhanced susceptibility of affected otters to S. neurona and exacerbated the neurological signs exhibited by stranded animals. Other factors that may have contributed to the severity of this epizootic include a large rainstorm that preceded the event and an abundance of razor clams near local beaches, attracting numerous otters close to shore within the affected area. This is the first report of a localized epizootic in marine wildlife caused by apicomplexan protozoa. ?? 2010 Elsevier B.V.

  15. THE HIGH COST OF MOTHERHOOD: END-LACTATION SYNDROME IN SOUTHERN SEA OTTERS (ENHYDRA LUTRIS NEREIS) ON THE CENTRAL CALIFORNIA COAST, USA.

    PubMed

    Chinn, Sarah M; Miller, Melissa A; Tinker, M Tim; Staedler, Michelle M; Batac, Francesca I; Dodd, Erin M; Henkel, Laird A

    2016-04-28

    Sea otters ( Enhydra lutris ) have exceptionally high energetic requirements, which nearly double during lactation and pup care. Thus, females are extremely vulnerable to caloric insufficiency. Despite a number of compensatory strategies, the metabolic challenge of reproduction culminates in numerous maternal deaths annually. Massive depletion of energy reserves results in a case presentation that we define as end-lactation syndrome (ELS), characterized by moderate to severe emaciation not attributable to a concurrent, independent disease process in females dying during late pup care or postweaning. We compiled detailed data for 108 adult female southern sea otters ( Enhydra lutris nereis) examined postmortem that stranded in California, US, 2005-12, and assessed pathology, reproductive status, and the location and timing of stranding. We introduce simple, grossly apparent, standardized physical criteria to assess reproductive stage for female sea otters. We also describe ELS, examine associated risk factors, and highlight female life history strategies that likely optimize reproduction and survival. Our data suggest that females can reset both the timing and energetic demands of reproduction through fetal loss, pup abandonment, or early weaning as part of specific physiologic checkpoints during each reproductive cycle. Females appear to preload nutritionally during delayed implantation and gestation to increase fitness and reproductive success. We found that ELS was a major cause of death, affecting 56% of enrolled adult females. Peak ELS prevalence occurred in late spring, possibly reflecting the population trend toward fall/winter pupping. Increasing age and number of pregnancies were associated with a higher risk of ELS. Although the proportion of ELS females was highest in areas with dense sea otter populations, cases were recovered throughout the range, suggesting that death from ELS is associated with, but not solely caused by, population resource limitation.

  16. THE HIGH COST OF MOTHERHOOD: END-LACTATION SYNDROME IN SOUTHERN SEA OTTERS (ENHYDRA LUTRIS NEREIS) ON THE CENTRAL CALIFORNIA COAST, USA.

    PubMed

    Chinn, Sarah M; Miller, Melissa A; Tinker, M Tim; Staedler, Michelle M; Batac, Francesca I; Dodd, Erin M; Henkel, Laird A

    2016-04-28

    Sea otters ( Enhydra lutris ) have exceptionally high energetic requirements, which nearly double during lactation and pup care. Thus, females are extremely vulnerable to caloric insufficiency. Despite a number of compensatory strategies, the metabolic challenge of reproduction culminates in numerous maternal deaths annually. Massive depletion of energy reserves results in a case presentation that we define as end-lactation syndrome (ELS), characterized by moderate to severe emaciation not attributable to a concurrent, independent disease process in females dying during late pup care or postweaning. We compiled detailed data for 108 adult female southern sea otters ( Enhydra lutris nereis) examined postmortem that stranded in California, US, 2005-12, and assessed pathology, reproductive status, and the location and timing of stranding. We introduce simple, grossly apparent, standardized physical criteria to assess reproductive stage for female sea otters. We also describe ELS, examine associated risk factors, and highlight female life history strategies that likely optimize reproduction and survival. Our data suggest that females can reset both the timing and energetic demands of reproduction through fetal loss, pup abandonment, or early weaning as part of specific physiologic checkpoints during each reproductive cycle. Females appear to preload nutritionally during delayed implantation and gestation to increase fitness and reproductive success. We found that ELS was a major cause of death, affecting 56% of enrolled adult females. Peak ELS prevalence occurred in late spring, possibly reflecting the population trend toward fall/winter pupping. Increasing age and number of pregnancies were associated with a higher risk of ELS. Although the proportion of ELS females was highest in areas with dense sea otter populations, cases were recovered throughout the range, suggesting that death from ELS is associated with, but not solely caused by, population resource limitation

  17. The effects of chronic radiation on reproductive success of the polychaete worm Neanthes arenaceodentata

    SciTech Connect

    Harrison, F.L.; Anderson, S.L.

    1988-12-01

    The effects of lifetime exposure to chronic irradiation on reproductive success were assessed for laboratory populations of the polychaete worm Neanthes arenaceodentata. Lifetime exposure was initiated upon the spawning of the P1 female and was terminated upon spawning of the F1 female. Groups of experimental worms received either no radiation (controls) or 0.19, 2.1, or 17 mGy/h. The total dose received by the worms was either background or approximately 0.55, 6.5, or 54 Gy, respectively. The broods from the F1 mated pairs were sacrificed before hatching occurred, and information was obtained on brood size, on the number of normal and abnormal embryos, and on the number of embryos that were living, dying, and dead. The mean number of embryos in the broods from the F1 females exposed to lifetime radiation of 0.19 and 2.1 mGy/h was not significantly different from the mean number of embryos from control females; however, the mean number of embryos was different from those F1 females exposed to 17 mGy/h. There was a significant reduction in the number of live embryos in the broods from the F1 mated pairs that were exposed to the lowest dose rate given, 0.19 mGy/h, as well as those exposed to 2.1 and 17 mGy/h. Also, increased percentages of abnormal embryos were determined in the broods of all the radiation-exposed groups. 39 refs., 10 figs., 15 tabs.

  18. Capitellid connections: contributions from neuromuscular development of the maldanid polychaete Axiothella rubrocincta (Annelida)

    PubMed Central

    2010-01-01

    Background Numerous phylogenetic analyses on polychaete annelids suggest a taxon Capitellida that comprises the three families Maldanidae, Arenicolidae and Capitellidae. Recent molecular studies support the position of the Echiura, traditionally ranked as a separate phylum, within the capitellids. In order to test the robustness of this molecular-based hypothesis we take a different approach using comparative analyses of nervous and muscle system development in the maldanid Axiothella rubrocincta. Employing immunocytochemistry in combination with confocal laserscanning microscopy, we broaden the database on capitellid organogenesis, thereby incorporating classical histological data in our analysis. Besides assessing possible shared features with the echiurans, we also discuss the variability of neural and muscular characters within the Capitellida. Results The scaffold of the adult central nervous system, which is already established in early developmental stages of Axiothella, consists of cerebral commissures that give rise to simple circumesophageal connectives with fused ventral and dorsal roots and a single ventral neurite bundle. From the latter arise segmental neurites that innervate the peripheral bodywall. Since there is no observable regular pattern, and individual neurites are lost during ontogeny, their exact arrangement remains elusive. The pharynx is encircled by a prominent stomatogastric nerve ring, with a pair of anterior and lateral proboscis neurites directly connecting it to the central nervous system. One pair of ventral and one pair of dorsal longitudinal muscles form the earliest rudiments of the bodywall musculature in late larval stages, while a continuous layer of circular muscles is lacking throughout ontogeny. Conclusions Comparative neurodevelopmental analysis of capitellid and echiuran species reveals several common characters, including simple circumesophageal connectives, a single fused ventral nerve strand, and a stomatogastric ring

  19. Predicting the Dispersal Potential of an Invasive Polychaete Pest along a Complex Coastal Biome.

    PubMed

    David, Andrew A; Matthee, Conrad A; Loveday, Benjamin R; Simon, Carol A

    2016-10-01

    Boccardia proboscidea is a recently introduced polychaete in South Africa where it is a notorious pest of commercially reared abalone. Populations were originally restricted to abalone farms but a recent exodus into the wild at some localities has raised conservation concerns due to the species' invasive status in other parts of the world. Here, we assessed the dispersal potential of B. proboscidea by using a population genetic and oceanographic modeling approach. Since the worm is in its incipient stages of a potential invasion, we used the closely related Polydora hoplura as a proxy due its similar reproductive strategy and its status as a pest of commercially reared oysters in the country. Populations of P. hoplura were sampled from seven different localities and a section of the mtDNA gene, Cyt b and the intron ATPSa was amplified. A high resolution model of the coastal waters around southern Africa was constructed using the Regional Ocean Modeling System. Larvae were represented by passive drifters that were deployed at specific points along the coast and dispersal was quantified after a 12-month integration period. Our results showed discordance between the genetic and modeling data. There was low genetic structure (Φ = 0.04 for both markers) and no geographic patterning of mtDNA and nDNA haplotypes. However, the dispersal model found limited connectivity around Cape Point-a major phylogeographic barrier on the southern African coast. This discordance was attributed to anthropogenic movement of larvae and adult worms due to vectors such as aquaculture and shipping. As such, we hypothesized that cryptic dispersal could be overestimating genetic connectivity. Though wild populations of B. proboscidea could become isolated due to the Cape Point barrier, anthropogenic movement may play the critical role in facilitating the dispersal and spread of this species on the southern African coast.

  20. Phylogenetic characterization of the epibiotic bacteria associated with the hydrothermal vent polychaete Alvinella pompejana.

    PubMed Central

    Haddad, A; Camacho, F; Durand, P; Cary, S C

    1995-01-01

    Alvinella pompejana is a polychaetous annelid that inhabits active deep-sea hydrothermal vent sites along the East Pacific Rise, where it colonizes the walls of actively venting high-temperature chimneys. An abundant, morphologically diverse epibiotic microflora is associated with the worm's dorsal integument, with a highly integrated filamentous morphotype clearly dominating the microbial biomass. It has been suggested that this bacterial population participates in either the nutrition of the worm or in detoxification of the worm's immediate environment. The primary goal of this study was to phylogenetically characterize selected epibionts through the analysis of 16S rRNA gene sequences. Nucleic acids were extracted from bacteria collected from the dorsal surface of A. pompejana. 16S rRNA genes were amplified with universal bacterial primers by the PCR. These genes were subsequently cloned, and the resulting clone library was screened by restriction fragment length polymorphism analysis to identify distinct clone types. The restriction fragment length polymorphism analysis identified 32 different clone families in the library. Four of these families were clearly dominant, representing more than 65% of the library. Representatives from the four most abundant clone families were chosen for complete 16S rRNA gene sequencing and phylogenetic analysis. These gene sequences were analyzed by a variety of phylogenetic inference methods and found to be related to the newly established epsilon subdivision of the division Proteobacteria. Secondary structural model comparisons and comparisons of established signature base positions in the 16S rRNA confirmed the placement of the Alvinella clones in the epsilon subdivision of the Proteobacteria. PMID:7544093

  1. Characterization of vibrios diversity in the mucus of the polychaete Myxicola infundibulum (Annellida, Polichaeta).

    PubMed

    Stabili, Loredana; Giangrande, Adriana; Pizzolante, Graziano; Caruso, Giorgia; Alifano, Pietro

    2014-01-01

    Vibrios are among the most abundant culturable microbes in aquatic environments. They can be either free-living in the water column or associated with several marine organisms as mutualists, saprophytes, or parasites. In the present study we analysed vibrios abundance and diversity in the mucus of the polychaete Myxicola infundibulum, complementing culture-based with molecular methods. Vibrios reached 4.6 × 10(3) CFU mL(-1) thus representing a conspicuous component of the heterotrophic culturable bacteria. In addition, luminous vibrios accounted for about 60% of the total culturable vibrios in the mucus. The isolates were assigned to: Vibrio gigantis, Vibrio fischeri, Vibrio jasicida, Vibrio crassostreae, Vibrio kanaloae, and Vibrio xuii. Two Vibrio isolates (MI-13 and MI-15) may belong to a new species. We also tested the ability of the Vibrio isolates to grow on M. infundibulum mucus as the sole carbon source. All strains showed appreciable growth in the presence of mucus, leading us to conclude that this matrix, which is abundant and covers the animal entirely, may represent a microcosm and a food source for some bacteria, playing a crucial role in the structuring of a mucus-associated beneficial microbial community. Moreover, the trophic relationship between vibrios and M. infundibulum mucus could be enhanced by the protection that mucus offers to vibrios. The results of this study represent a contribution to the growing evidence for complex and dynamic invertebrate-microbe associations present in nature and highlight the importance of exploring relationships that Vibrio species establish with marine invertebrates.

  2. Facilitation of macroalgae by the sedimentary tube forming polychaete Diopatra cuprea

    NASA Astrophysics Data System (ADS)

    Thomsen, M. S.; McGlathery, K.

    2005-01-01

    Marine foundation organisms such as seagrasses, corals, and kelps facilitate the distribution of numerous organisms by creating refuges from environmental stressors and by providing food and substrate for settlement and growth. Barren soft-sediment systems often have faunal organisms that facilitate other species by habitat modification. We investigated how an abundant (21 m -2) tube cap forming polychaete, Diopatra cuprea, facilitates macroalgal distribution in Hog Island Bay, a turbid shallow tidal lagoon in Virginia (USA). Seventy percent of the number of mudflat macroalgae were found incorporated into protruding D. cuprea tube caps and field experiments showed that D. cuprea facilitates algal persistence by providing a stable substrate retaining algae against hydrodynamic forces such as tidal flushing and storm surge. If tube caps were removed, simulating storm-induced erosion, they were rebuilt within days and new drift algae incorporated. Also, D. cuprea facilitated the algal assemblage by fragmenting thalli in the attachment process, thereby ensuring a constant fragment supply for vegetative re-growth if storm-induced pruning occurs. On a species-specific level, Gracilaria verrucosa and Ulva curvata benefited more from tube cap construction compared to Fucus vesiculosus, Agardhiella subulata and the alien Codium fragile ssp. tomentosoides. This was partly because G. verrucosa and U. curvata were incorporated and fragmented more readily, and partly because they probably have physiological, morphological and biomechanical traits that enable them to better co-exist with D. cuprea. These results suggest that macroalgal distribution throughout Hog Island Bay to a large extent is linked to the distribution of D. cuprea. The processes of algal attachment, retainment, recovery, re-growth and fragmentation, can have important ecosystem implications because of the sheer abundance of the Diopatra- Gracilaria/Ulva association.

  3. Predicting the Dispersal Potential of an Invasive Polychaete Pest along a Complex Coastal Biome.

    PubMed

    David, Andrew A; Matthee, Conrad A; Loveday, Benjamin R; Simon, Carol A

    2016-10-01

    Boccardia proboscidea is a recently introduced polychaete in South Africa where it is a notorious pest of commercially reared abalone. Populations were originally restricted to abalone farms but a recent exodus into the wild at some localities has raised conservation concerns due to the species' invasive status in other parts of the world. Here, we assessed the dispersal potential of B. proboscidea by using a population genetic and oceanographic modeling approach. Since the worm is in its incipient stages of a potential invasion, we used the closely related Polydora hoplura as a proxy due its similar reproductive strategy and its status as a pest of commercially reared oysters in the country. Populations of P. hoplura were sampled from seven different localities and a section of the mtDNA gene, Cyt b and the intron ATPSa was amplified. A high resolution model of the coastal waters around southern Africa was constructed using the Regional Ocean Modeling System. Larvae were represented by passive drifters that were deployed at specific points along the coast and dispersal was quantified after a 12-month integration period. Our results showed discordance between the genetic and modeling data. There was low genetic structure (Φ = 0.04 for both markers) and no geographic patterning of mtDNA and nDNA haplotypes. However, the dispersal model found limited connectivity around Cape Point-a major phylogeographic barrier on the southern African coast. This discordance was attributed to anthropogenic movement of larvae and adult worms due to vectors such as aquaculture and shipping. As such, we hypothesized that cryptic dispersal could be overestimating genetic connectivity. Though wild populations of B. proboscidea could become isolated due to the Cape Point barrier, anthropogenic movement may play the critical role in facilitating the dispersal and spread of this species on the southern African coast. PMID:27126982

  4. DNA methylation and temperature stress in an Antarctic polychaete, Spiophanes tcherniai

    PubMed Central

    Marsh, Adam G.; Pasqualone, Annamarie A.

    2014-01-01

    Epigenetic modifications of DNA and histones are a primary mechanism by which gene expression activities may be modified in response to environmental stimuli. Here we characterize patterns of methyl-cytosine composition in the marine polychaete Spiophanes tcherniai from McMurdo Sound, Antarctica. We cultured adult worms at two temperatures, −1.5°C (ambient control) and +4°C (warm treatment), for 4 weeks. We observed a rapid capacity for S. tcherniai organismal respiration rates and underlying catalytic rates of citrate synthase at +4°C to return to control levels in less than 4 weeks. We profiled changes in the methylation states of CpG sites in these treatments using an NGS strategy to computationally reconstruct and quantify methylation status across the genome. In our analysis we recovered 120,000 CpG sites in assembled contigs from both treatments. Of those, we were able to align 28,000 CpG sites in common between the two sample groups. In comparing these aligned sites between treatments, only 3000 (11%) evidenced a change in methylation state, but over 85% of changes involved a gain of a 5-methyl group on a CpG site (net increase in methyation). The ability to score CpG sites as partially methylated among gDNA copies in a sample opens up a new avenue for assessing DNA methylation responses to changing environments. By quantitatively distinguishing a “mixed” population of copies of one CpG site, we can begin to identify dynamic, non-binary, continuous-response reactions in DNA methylation intensity or density that previously may have been overlooked as noise. PMID:24847277

  5. Benthic polychaete diversity patterns and community structure in the Whittard Canyon system and adjacent slope (NE Atlantic)

    NASA Astrophysics Data System (ADS)

    Gunton, Laetitia M.; Neal, Lenka; Gooday, Andrew J.; Bett, Brian J.; Glover, Adrian G.

    2015-12-01

    We examined deep-sea macrofaunal polychaete species assemblage composition, diversity and turnover in the Whittard Canyon system (NE Atlantic) using replicate megacore samples from three of the canyon branches and one site on the continental slope to the west of the canyon, all at ~3500 m water depth. A total of 110 polychaete species were recorded. Paramphinome jeffreysii was the most abundant species (2326 ind. m-2) followed by Aurospio sp. B (646 ind. m-2), Opheliidae sp. A (393 ind. m-2), Prionospio sp. I (380 ind. m-2), and Ophelina abranchiata (227 ind. m-2). Species composition varied significantly across all sites. From west to east, the dominance of Paramphinome jeffreysii increased from 12.9% on the slope to 39.6% in the Eastern branch. Ordination of species composition revealed that the Central and Eastern branches were most similar, whereas the Western branch and slope sites were more distinct. High abundances of P. jeffreysii and Opheliidae sp. A characterised the Eastern branch of the canyon and may indicate an opportunistic response to a possible recent input of organic matter inside the canyon. Species richness and diversity indices were higher on the slope compared with inside the canyon, and the slope site had higher species evenness. Within the canyon, species diversity between branches was broadly similar. Despite depressed diversity within the canyon compared with the adjacent slope, the fact that 46 of the 99 polychaete species found in the Whittard Canyon were not present on the adjacent slope suggests that this feature may enhance the regional species pool. However, our sampling effort on the adjacent slope was insufficient to confirm this conclusion.

  6. Polychaete Community of a Marine Protected Area along the West Coast of India-Prior and Post the Tropical Cyclone, Phyan.

    PubMed

    Sukumaran, Soniya; Vijapure, Tejal; Kubal, Priti; Mulik, Jyoti; Rokade, M A; Salvi, Shailesh; Thomas, Jubin; Naidu, V S

    2016-01-01

    Tropical cyclones are extreme random meteorological events that can have profound implications to coastal biodiversities. Given that the frequency, intensity and duration of these events are poised to increase due to the global climate change, understanding the ecological impacts of such erratic occurrences becomes imperative to devise better management strategies. The eventful passage of the tropical cyclone, Phyan, along the northwestern coast of India in November 2009, coupled with the availability of historical data presented a rare opportunity to elucidate the consequences on the polychaete assemblages of the Malvan Marine Sanctuary and their subsequent recovery. This was achieved by comparison of the pre- and post-Phyan seasonal data from four different sites in and around the Sanctuary. MDS analyses and polychaete community parameters suggested conspicuous cyclone related effects on the polychaete community characteristics in the three outer stations off Malvan, whereas the relatively protected bay station remained more or less unscathed. Impacts, attributable to the cyclone apart from seasonal variations, included changes in polychaete composition, reductions in total polychaete density, species diversity, evenness and functional groups. Dominance of the opportunistic polychaete, Paraprionospiopatiens was all pervasive just after Phyan, resulting in poor diversity and evenness values. In the outer stations, diverse feeding modes present prior to the cyclone were replaced by microphagous feeders post the disturbance. However, the study also observed complete recovery as substantiated by the improvement inpolychaete density, diversity indices and re-instatement of multiple feeding guilds in affected areas. This resilience of the coastal waters off Malvan is attributed to its marine protected status, implying that reduced human interference aided rapid revival of damaged ecosystems. PMID:27556895

  7. Polychaete Community of a Marine Protected Area along the West Coast of India—Prior and Post the Tropical Cyclone, Phyan

    PubMed Central

    Kubal, Priti; Mulik, Jyoti; Rokade, M. A.; Salvi, Shailesh; Thomas, Jubin; Naidu, V. S.

    2016-01-01

    Tropical cyclones are extreme random meteorological events that can have profound implications to coastal biodiversities. Given that the frequency, intensity and duration of these events are poised to increase due to the global climate change, understanding the ecological impacts of such erratic occurrences becomes imperative to devise better management strategies. The eventful passage of the tropical cyclone, Phyan, along the northwestern coast of India in November 2009, coupled with the availability of historical data presented a rare opportunity to elucidate the consequences on the polychaete assemblages of the Malvan Marine Sanctuary and their subsequent recovery. This was achieved by comparison of the pre- and post-Phyan seasonal data from four different sites in and around the Sanctuary. MDS analyses and polychaete community parameters suggested conspicuous cyclone related effects on the polychaete community characteristics in the three outer stations off Malvan, whereas the relatively protected bay station remained more or less unscathed. Impacts, attributable to the cyclone apart from seasonal variations, included changes in polychaete composition, reductions in total polychaete density, species diversity, evenness and functional groups. Dominance of the opportunistic polychaete, Paraprionospiopatiens was all pervasive just after Phyan, resulting in poor diversity and evenness values. In the outer stations, diverse feeding modes present prior to the cyclone were replaced by microphagous feeders post the disturbance. However, the study also observed complete recovery as substantiated by the improvement inpolychaete density, diversity indices and re-instatement of multiple feeding guilds in affected areas. This resilience of the coastal waters off Malvan is attributed to its marine protected status, implying that reduced human interference aided rapid revival of damaged ecosystems. PMID:27556895

  8. Use of a non-homologous end-joining-deficient strain (delta-ku70) of the biocontrol fungus Trichoderma virens to investigate the function of the laccase gene lcc1 in sclerotia degradation

    PubMed Central

    Catalano, Valentina; Vergara, Mariarosaria; Hauzenberger, Jasmin R.; Seiboth, Bernhard; Sarrocco, Sabrina; Vannacci, Giovanni; Kubicek, Christian P.

    2010-01-01

    The aim of this study was to apply a generated Δtku70 strain with increased homologous recombination efficiency from the mycoparasitic fungus Trichoderma virens for studying the involvement of laccases in the degradation of sclerotia of plant pathogenic fungi. Inactivation of the non-homologous end-joining pathway has become a successful tool in filamentous fungi to overcome poor targeting efficiencies for genetic engineering. Here, we applied this principle to the biocontrol fungus T. virens, strain I10, by deleting its tku70 gene. This strain was subsequently used to delete the laccase gene lcc1, which we found to be expressed after interaction of T. virens with sclerotia of the plant pathogenic fungi Botrytis cinerea and Sclerotinia sclerotiorum. Lcc1 was strongly upregulated at early colonization of B. cinerea sclerotia and steadily induced during colonization of S. sclerotiorum sclerotia. The Δtku70Δlcc1 mutant was altered in its ability to degrade the sclerotia of B. cinerea and S. sclerotiorum. Interestingly, while the decaying ability for B. cinerea sclerotia was significantly decreased, that to degrade S. sclerotiorum sclerotia was even enhanced, suggesting the operation of different mechanisms in the mycoparasitism of these two types of sclerotia by the laccase LCC1. PMID:20872221

  9. Anti-Giardia activity of phenolic-rich essential oils: effects of Thymbra capitata, Origanum virens, Thymus zygis subsp. sylvestris, and Lippia graveolens on trophozoites growth, viability, adherence, and ultrastructure.

    PubMed

    Machado, Marisa; Dinis, Augusto M; Salgueiro, Ligia; Cavaleiro, Carlos; Custódio, José B A; Sousa, Maria do Céu

    2010-04-01

    The present work evaluates the anti-Giardia activity of phenolic-rich essential oils obtained from Thymbra capitata, Origanum virens, Thymus zygis subsp. sylvestris chemotype thymol, and Lippia graveolens aromatic plants. The effects were evaluated on parasite growth, cell viability adherence, and morphology. The tested essential oils inhibited the growth of Giardia lamblia. T. capitata essential oil is the most active followed by O. virens, T. zygis subsp. sylvestris, and L. graveolens oils. The tested essential oils at IC50 (71-257) microg/ml inhibited parasite adherence (p < 0.001) since the first hour of incubation and were able to kill almost 50% of the parasites population in a time-dependent manner. The main ultrastructural alterations promoted by essential oils were deformations in typical trophozoite appearance, often roundly shape, irregular dorsal and ventral surface, presence of membrane blebs, electrodense precipitates in cytoplasm and nuclei, and internalization of flagella and ventral disc. Our data suggest that essential oils induced cell death probably by processes associated to the loss of osmoregulation caused by plasmatic membrane alterations. Experiments revealed that the essential oils did not present cytotoxic effects in mammalian cells. In conclusion, T. capitata, O. virens, T. zygis subsp. sylvestris chemotype thymol, and L. graveolens essential oils have antigiardial activity in vitro and seem to have potential for the treatment of the parasitic disease caused by the protozoan G. lamblia. PMID:20217133

  10. Use of a non-homologous end-joining-deficient strain (delta-ku70) of the biocontrol fungus Trichoderma virens to investigate the function of the laccase gene lcc1 in sclerotia degradation.

    PubMed

    Catalano, Valentina; Vergara, Mariarosaria; Hauzenberger, Jasmin R; Seiboth, Bernhard; Sarrocco, Sabrina; Vannacci, Giovanni; Kubicek, Christian P; Seidl-Seiboth, Verena

    2011-02-01

    The aim of this study was to apply a generated Δtku70 strain with increased homologous recombination efficiency from the mycoparasitic fungus Trichoderma virens for studying the involvement of laccases in the degradation of sclerotia of plant pathogenic fungi. Inactivation of the non-homologous end-joining pathway has become a successful tool in filamentous fungi to overcome poor targeting efficiencies for genetic engineering. Here, we applied this principle to the biocontrol fungus T. virens, strain I10, by deleting its tku70 gene. This strain was subsequently used to delete the laccase gene lcc1, which we found to be expressed after interaction of T. virens with sclerotia of the plant pathogenic fungi Botrytis cinerea and Sclerotinia sclerotiorum. Lcc1 was strongly upregulated at early colonization of B. cinerea sclerotia and steadily induced during colonization of S. sclerotiorum sclerotia. The Δtku70Δlcc1 mutant was altered in its ability to degrade the sclerotia of B. cinerea and S. sclerotiorum. Interestingly, while the decaying ability for B. cinerea sclerotia was significantly decreased, that to degrade S. sclerotiorum sclerotia was even enhanced, suggesting the operation of different mechanisms in the mycoparasitism of these two types of sclerotia by the laccase LCC1. PMID:20872221

  11. Probing the characteristics of metal- and sulfide-binding proteins in hydrothermal vent polychaetes using HPLC/IES-MS

    SciTech Connect

    Martineu, P.; Juniper, S.K.; Ikonomou, M.G.; Thompson, J.

    1995-12-31

    Alvinellids polychaetes colonizing the surfaces of black smokers from Eastern Pacific hydrothermal vents occupy extreme environments with high levels of heavy metals and sulfide. Investigations of mechanisms that enable them to tolerate these extreme conditions indicate sulfide-binding capacity in the blood serum of Paralvinella palmiformis and accumulation of heavy metals in their tissues. A need to characterize metal-binding proteins lead the authors to improve purification and separation of metallothioneins (MTs) by reversed-phase liquid chromatography (RP-HPLC) on-line with electrospray mass spectrometry (ES/MS). A first separation step of small proteins from crude homogenates of worm tissues is performed on a size exclusion column following by accurate molecular weight identification with on-line LC-MS. This powerful technique has refined separation of isoform MT standards and weight characterization, and has provided an analytical tool to analyze metal-binding proteins from vent polychaetes. The authors are also applying this technique to separation of sulfide-binding proteins in blood serum and to identify ligands involved in sulfide detoxication and transport.

  12. Bioaccumulation of PAHs by the estuarine polychaete, Streblospio benedicti: Comparison between radioisotope and GC/MS analyses

    SciTech Connect

    Ferguson, P.L.; Chandler, G.T.; Shipp, M.R.

    1995-12-31

    Bioaccumulation of sediment associated organic contaminants can be measured using traditional analytical approaches such as gas chromatography/mass spectrometry, or by employing radioisotope techniques. The authors compared these methods by measuring bioaccumulation of common polycyclic aromatic hydrocarbons (PAHs) in sediments by the opportunistic deposit/suspension feeding polychaete, Streblospio benedicti. First, the authors exposed S. benedicti to {sup 14}C-fluoranthene for 28 days. On days 3, 6, 10, 18, and 28, worms were sampled and measured for {sup 14}C activity. They performed a similar 28d test with three non radiolabeled PAHs (fluoranthene, benzo[a]pyrene, and 1,2-benzanthracene). The S. benedicti body burden of each compound was quantified by gas chromatography-mass spectrometry. Results from the radioisotope assay indicate that S. benedicti accumulates sediment associated {sup 14}C-fluoranthene at a level 95-135X that of sediment after 28d. Differences between detected {sup 14}C activity and GC/MS measured fluoranthene in S. benedicti tissue may indicate transformation of the parent PAH to other compounds which could retain a radiolabel. GC/MS in turn may indicate the presence of a metabolic pathway which polychaetes such as S. benedicti utilize to eliminate PAH body burdens.

  13. Development of whole sediment bioassay using the marine/estuarine polychaetes Polydora cornuta Bosc 1802 and Boccardia proboscidea Hartman 1940

    SciTech Connect

    Pocklington, P.; Doe, K.; Huybers, A.; Wade, S.; Lee, D.

    1995-12-31

    The growing need by Environment Canada for a battery of marine toxicity tests has prompted the development of chronic, sublethal, sediment bioassay tests using marine or estuarine annelids (polychaetes). Initially several species of polychaetes found in the Atlantic, Pacific and Arctic waters were assessed and a few of these were selected for testing survival and sensitivity under laboratory conditions and sensitivity to reference toxicants using field collected specimens. From these experiments, the authors identified several promising species and attempts were made to culture them. To date they have been successful in culturing one species from the Atlantic coast--Polydora cornuta and one species from the Pacific Coast--Boccardia proboscidea. They have been able to generate sufficient numbers of same-age larvae, raise them under controlled conditions to juveniles/young adults, and, subject them to a variety of Non-Contaminant Effects Trials (NCETs) and Contaminant Effects Trials (CETs). In the NCETs the authors determined the effect of food type and food ration, temperature, salinity, grain size, length of test condition. They found them to be moderately robust in terms of variable environmental parameters. In the CETs they found this species to be sensitive to sediments considered by Environment Canada to be toxic. They also determined the animal`s sensitivity to a reference toxicant CdCl{sub 2} (96 hr LC50).

  14. Measurement and modeling of polychlorinated biphenyl bioaccumulation from sediment for the marine polychaete neanthes arenaceodentata and response to sorbent amendment

    USGS Publications Warehouse

    Janssen, E.M.-L.; Croteau, M.-N.; Luoma, S.N.; Luthy, R.G.

    2010-01-01

    Bioaccumulation rates of polychlorinated biphenyls (PCBs) for the marine polychaete Neanthes arenaceodentata were characterized, including PCB uptake rates from water and sediment, and the effect of sorbent amendment to the sediment on PCB bioavailability, organism growth, and lipid content. Physiological parameters were incorporated into a biodynamic model to predict contaminant uptake. The results indicate rapid PCB uptake from contaminated sediment and significant organism growth dilution during time-series exposure studies. PCB uptake from the aqueous phase accounted for less than 3% of the total uptake for this deposit-feeder. Proportional increase of gut residence time and assimilation efficiency as a consequence of the organism's growth was assessed by PCB uptake and a reactor theory model of gut architecture. Pulse-chase feeding and multilabeled stable isotope tracing techniques proved high sediment ingestion rates (i.e., 6?10 times of dry body weight per day) indicating that such deposit-feeders are promising biological indicators for sediment risk assessment. Activated carbon amendment reduced PCB uptake by 95% in laboratory experiments with no observed adverse growth effects on the marine polychaete. Biodynamic modeling explained the observed PCB body burdens for N. arenaceodentata, with and without sorbent amendment. ?? 2009 American Chemical Society.

  15. Nereidid polychaetes as the major diet of migratory shorebirds on the estuarine tidal flats at Fujimae-higata in Japan.

    PubMed

    Iwamatsu, Shinichiro; Suzuki, Akiko; Sato, Masanori

    2007-07-01

    The dietary items of five migratory shorebirds, Dunlin (Calidris alpina), Red-necked Stint (C. ruficollis), Grey Plover (Pluvialis squatarola), Whimbrel (Numenius phaeopus) and Black-headed Gull (Larus ridibundus), were examined by analyses of fecal droppings during the birds' migration or wintering and by surveys of macrobenthic fauna around their foraging sites on the tidal flats of Fujimae-higata, Nagoya, central Japan. Body parts of nereidid, capitellid, and spionid polychaetes and crustaceans were found in fecal droppings from all of these shorebirds. Two nereidid species (Hediste diadroma and Neanthes succinea) with relatively large body sizes seemed to be the majority dietary items. At one site, H. diadroma was dominant in terms of biomass (40-370 g/m(2)) throughout year except, for less than 1 g/m(2) in March and May (within or just after reproduction of this species). Monthly changes in the occurrence of food items in fecal droppings of C. alpina were examined in 1999 and 2000. Most (85-100%) of the fecal droppings contained nereidid body parts, including Hediste-specific simple chaetae from November to April, whereas only 23% of the droppings contained them in May. Chaetae of capitellid or spionid polychaetes were frequently found from January to April (38-86% of droppings). Crustacean body parts, including amphipod appendages, were frequently found from March to May (86-100% of droppings). The relationship between foraging habits of the shorebirds and the life history of their major prey nereidid species is discussed.

  16. Polychaete Annelid (segmented worms) Species Composition in the Deep Gulf of Mexico following the Deep Water Horizon (DWH) Oil Spill

    NASA Astrophysics Data System (ADS)

    QU, F.; Rowe, G.

    2012-12-01

    Sediments 5 to 9 km from the Deep Water Horizon (DWH) Oil Spill site were sampled using a 0.2 m2 box corer 5 months after the event to assess the effects of the oil spill on polychaete annelid (segmented worms) community structure. Numbers of species, abundance, and biodiversity indices were all significantly lower than pre-spill values from similar depths in the eastern Gulf of Mexico (GoM). All of the five dominant species were different. Non-selective deposit feeders and selective deposit feeders were still the most frequent feeding guilds, but their abundances decreased significantly after the event. A large number of carnivorous Sigalionidae may be a response to an accumulation of PAHs on the sediment. Multivariate analyses (CLUSTER and multidimensional scaling (MDS)) illustrate the differences between assemblages near the DWH and those from prior studies in similar deep GoM habitats. In sum, the polychaete populations appeared to be at an early stage of succession in the recovery from the spill or they could be a resident assemblage that is the natural characteristic infauna in or adjacent to natural seeps of fossil hydrocarbons.

  17. Proteomic Changes between Male and Female Worms of the Polychaetous Annelid Neanthes arenaceodentata before and after Spawning

    PubMed Central

    Chandramouli, Kondethimmanahalli H.; Ravasi, Timothy; Reish, Donald; Qian, Pei-Yuan

    2013-01-01

    The Neanthesacuminata species complex (Polychaeta) are cosmopolitan in distribution. Neanthesarenaceodentata, Southern California member of the N. acuminata complex, has been widely used as toxicological test animal in the marine environment. Method of reproduction is unique in this polychaete complex. Same sexes fight and opposite sexes lie side by side until egg laying. Females lose about 75% of their weight and die after laying eggs. The male, capable of reproducing up to nine times, fertilizes the eggs and incubates the embryos for 3-4 weeks. The objective of this study was to determine if there is any set of proteins that influences this unique pattern of reproduction. Gel-based two-dimensional electrophoresis (2-DE) and gel-free quantitative proteomics methods were used to identify differential protein expression patterns before and after spawning in both male and female N. arenaceodentata. Males showed a higher degree of similarity in protein expression patterns but females showed large changes in phosphoproteme before and after spawning. There was a decrease (about 70%) in the number of detected phosphoproteins in spent females. The proteins involved in muscular development, cell signaling, structure and integrity, and translation were differentially expressed. This study provides proteomic insights of the male and female worms that may serve as a foundation for better understanding of unusual reproductive patterns in polychaete worms. PMID:24023665

  18. Influence of environmental conditions on early development of the hydrothermal vent polychaete Alvinella pompejana.

    PubMed

    Pradillon, Florence; Le Bris, Nadine; Shillito, Bruce; Young, Craig M; Gaill, Françoise

    2005-04-01

    Dispersal and colonisation processes at deep-sea vents are still not fully understood, essentially because early life stages of vent species remain unknown. The polychaete worm Alvinella pompejana forms colonies on chimney walls at East Pacific Rise vent sites where the temperature can frequently exceed 20 degrees C. In vitro studies in pressure vessels showed that the early embryos tolerate temperatures in a lower range (10-14 degrees C), suggesting that they would have to escape the colony to develop. Pressure vessels offer the advantage that each parameter can be independently controlled, but they do not simulate the more complex and dynamic conditions naturally encountered at vent sites. Accordingly, in addition to incubations in pressure vessels, we incubated embryos directly at a vent site, in different habitats along a gradient of hydrothermal influence. Embryos incubated on an adult A. pompejana colony where temperature and H(2)S concentrations were relatively high showed a very low survival rate and did not develop, whereas embryos incubated in a Riftia pachyptila clump environment with a lower hydrothermal signature, or at the base of the chimney where the influence of the hydrothermal activity was very weak, survived well and developed. Although the average temperature recorded in the A. pompejana colony was within the range tolerated by embryos (13 degrees C), frequent peaks above 20 degrees C were recorded. Estimated sulphide concentration at this site reached 200 mumol l(-1). Punctuated exposure to both high temperature and elevated sulphide levels probably explain the low survival of embryos within the A. pompejana colony. The in situ experiments further support the idea that embryos require conditions with moderate hydrothermal influence not generally found within an adult colony. However, as much more benign physicochemical conditions can be found within a few tens of cm of adult colonies, embryos do not necessarily have to leave their vent of

  19. Temporal genetic structure in a poecilogonous polychaete: the interplay of developmental mode and environmental stochasticity

    PubMed Central

    2014-01-01

    Background Temporal variation in the genetic structure of populations can be caused by multiple factors, including natural selection, stochastic environmental variation, migration, or genetic drift. In benthic marine species, the developmental mode of larvae may indicate a possibility for temporal genetic variation: species with dispersive planktonic larvae are expected to be more likely to show temporal genetic variation than species with benthic or brooded non-dispersive larvae, due to differences in larval mortality and dispersal ability. We examined temporal genetic structure in populations of Pygospio elegans, a poecilogonous polychaete with within-species variation in developmental mode. P. elegans produces either planktonic, benthic, or intermediate larvae, varying both among and within populations, providing a within-species test of the generality of a relationship between temporal genetic variation and larval developmental mode. Results In contrast to our expectations, our microsatellite analyses of P. elegans revealed temporal genetic stability in the UK population with planktonic larvae, whereas there was variation indicative of drift in temporal samples of the populations from the Baltic Sea, which have predominantly benthic and intermediate larvae. We also detected temporal variation in relatedness within these populations. A large temporal shift in genetic structure was detected in a population from the Netherlands, having multiple developmental modes. This shift could have been caused by local extiction due to extreme environmental conditions and (re)colonization by planktonic larvae from neighboring populations. Conclusions In our study of P. elegans, temporal genetic variation appears to be due to not only larval developmental mode, but also the stochastic environment of adults. Large temporal genetic shifts may be more likely in marine intertidal habitats (e.g. North Sea and Wadden Sea) which are more prone to environmental stochasticity than the

  20. Inter-annual dynamics of abyssal polychaete communities in the North East Pacific and North East Atlantic—A family-level study

    NASA Astrophysics Data System (ADS)

    Laguionie-Marchais, C.; Billett, D. S. M.; Paterson, G. L. D.; Ruhl, H. A.; Soto, E. H.; Smith, K. L., Jr.; Thatje, S.

    2013-05-01

    Characterising how deep-sea communities change on contemporary time-scales and understanding underlying ecosystem processes has become important under changing climate and the rise in the exploitation of deep-sea resources. However, little is known about these dynamics and processes. Long-term observations from which inter-annual variations can be detected are scarce in the deep sea. This study examines inter-annual changes in density, family richness and evenness, family and functional group rank abundance distributions of infaunal polychaetes at two abyssal stations in the North East Pacific (Station M, 1991 to 2005) and in the North East Atlantic (Porcupine Abyssal Plain, 1991 to 1999). The two long-term data sets were used to investigate not only if polychaete community structure and composition varied at inter-annual scales in terms of diversity and rank abundance distributions but also if any changes were related to previous observations in megafauna and environmental factors at each locality. The polychaete community structure at each locality was analysed using univariate statistics as well as multivariate ordination techniques based on Bray-Curtis similarity of the yearly family density. Sub-surface deposit feeders, such as Paraonidae, dominated the North East Pacific, whereas surface deposit feeders, such as Cirratulidae, dominated the North East Atlantic. Both stations showed inter-annual variations in density, family evenness and rank abundance distributions. The greatest changes occurred in 1998 in both time series when polychaete densities peaked, and switches in the rank abundance of the most abundant families and functional groups took place. Inter-annual variations in the polychaete community were correlated with a limited number of holothurian species changes, but no correlation was found with particulate organic matter flux or climate indices. Ecological and environmental factors behind the family-level changes remain elusive. Overall, changes in

  1. Fauna of whale falls: systematics and ecology of a new polychaete (Annelida: Chrysopetalidae) from the deep Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Dahlgren, Thomas G.; Glover, Adrian G.; Baco, Amy; Smith, Craig R.

    2004-12-01

    Vigtorniella flokati, a new species of polychaete worm associated with decaying whale remains, is described. Three separate V. flokati populations were sampled using submersibles: two associated with implanted gray whale carcasses in the San Diego Trough (1240 m depth) and the Santa Cruz Basin (1670 m) off California, and one from sperm whale and balaeanopterid bones implanted on the slope of Oahu, Hawaii at 1000 m. Extraordinarily large numbers of live specimens were observed and videotaped in situ using submersibles in the San Diego Trough and the Santa Cruz Basin. The populations on the carcass implanted for 4 months in San Diego Trough, and on the bones implanted for 2 years off Oahu, were composed only of small sized individuals (including juveniles). V. flokati most closely resembles the poorly known V. zaikai Kiseleva, 1992, described from the Black Sea. Forty-six morphological characters were used in a phylogenetic analysis of selected nereidiform polychaetes. The resulting most-parsimonious trees indicate sister taxon status between V. flokati and V. zaikai, and that this clade is sister to the putatively ancient polychaete clade Chrysopetalidae. Whale falls, which are intense point sources of organic enrichment at the deep-sea floor, pass through three successional stages. V. flokati appears to colonize the middle, "enrichment opportunist" stage, inhabiting organic-rich bones and sediments ˜4-24 months after carcass arrival. V. flokati exhibits remarkable behavior, clinging posteriorly to whale bones or nearby sediments to form a writhing carpet at densities exceeding 8000 m -2. Its extraordinary abundance on whale falls, and apparent absence from other habitats, suggests it to be a whale-fall specialist. The precise feeding mechanism of the worm remains unknown, but we hypothesize that it may utilize dissolved organic carbon derived from the organic-rich setting of whale falls. The widespread occurrence of V. flokati on ephemeral, food-rich habitat

  2. Experimental evidence for evolved tolerance to avian malaria in a wild population of low elevation Hawai'i 'Amakihi (Hemignathus virens).

    PubMed

    Atkinson, Carter T; Saili, Katerine S; Utzurrum, Ruth B; Jarvi, Susan I

    2013-12-01

    Introduced vector-borne diseases, particularly avian malaria (Plasmodium relictum) and avian pox virus (Avipoxvirus spp.), continue to play significant roles in the decline and extinction of native forest birds in the Hawaiian Islands. Hawaiian honeycreepers are particularly susceptible to avian malaria and have survived into this century largely because of persistence of high elevation refugia on Kaua'i, Maui, and Hawai'i Islands, where transmission is limited by cool temperatures. The long term stability of these refugia is increasingly threatened by warming trends associated with global climate change. Since cost effective and practical methods of vector control in many of these remote, rugged areas are lacking, adaptation through processes of natural selection may be the best long-term hope for recovery of many of these species. We document emergence of tolerance rather than resistance to avian malaria in a recent, rapidly expanding low elevation population of Hawai'i 'Amakihi (Hemignathus virens) on the island of Hawai'i. Experimentally infected low elevation birds had lower mortality, lower reticulocyte counts during recovery from acute infection, lower weight loss, and no declines in food consumption relative to experimentally infected high elevation Hawai'i 'Amakihi in spite of similar intensities of infection. Emergence of this population provides an exceptional opportunity for determining physiological mechanisms and genetic markers associated with malaria tolerance that can be used to evaluate whether other, more threatened species have the capacity to adapt to this disease.

  3. Trichoderma virens PDR-28: a heavy metal-tolerant and plant growth-promoting fungus for remediation and bioenergy crop production on mine tailing soil.

    PubMed

    Babu, A Giridhar; Shim, Jaehong; Bang, Keuk-Soo; Shea, Patrick J; Oh, Byung-Taek

    2014-01-01

    A heavy metal-tolerant fungus, Trichoderma virens PDR-28, was isolated from rhizosphere soil and evaluated for use in remediating mine tailing soil and for plant biomass production. PDR-28 exhibited plant growth-promoting traits, including 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, acid phosphatase and phytase activity, siderophore production, and P solubilization. HMs were more available in mine tailing soil inoculated soil with PDR-28 than in uninoculated soil; the order of HM bioleaching was Cd > As > Zn > Pb > Cu. PDR-28 effectively removed HMs in the order of Pb > Cd > As > Zn > Cu from liquid media containing 100 mg HM L(-1). Inoculating HM-contaminated mine tailing soil with the fungus significantly increased the dry biomass of maize roots (64%) and shoots (56%). Chlorophyll, total soluble sugars (reducible and nonreducible), starch, and protein contents increased by 46%, 28%, 30%, and 29%, respectively, compared to plants grown in uninoculated soil. Inoculation increased heavy metal concentrations in maize roots by 25% (Cu) to 62% (Cd) and in shoots by 35% (Cu) to 64% (Pb) compared to uninoculated plants. Results suggest that PDR-28 would be beneficial for phytostabilization and plant biomass production as a potential source of biofuel in the quest for renewable energy.

  4. Experimental evidence for evolved tolerance to avian malaria in a wild population of low elevation Hawai`i `Amakihi (Hemignathus virens)

    USGS Publications Warehouse

    Atkinson, Carter T.; Saili, Katerine S.; Utzurrum, Ruth B.; Jarvi, Susan I.

    2013-01-01

    Introduced vector-borne diseases, particularly avian malaria (Plasmodium relictum) and avian pox virus (Avipoxvirus spp.), continue to play significant roles in the decline and extinction of native forest birds in the Hawaiian Islands. Hawaiian honeycreepers are particularly susceptible to avian malaria and have survived into this century largely because of persistence of high elevation refugia on Kaua‘i, Maui, and Hawai‘i Islands, where transmission is limited by cool temperatures. The long term stability of these refugia is increasingly threatened by warming trends associated with global climate change. Since cost effective and practical methods of vector control in many of these remote, rugged areas are lacking, adaptation through processes of natural selection may be the best long-term hope for recovery of many of these species. We document emergence of tolerance rather than resistance to avian malaria in a recent, rapidly expanding low elevation population of Hawai‘i ‘Amakihi (Hemignathus virens) on the island of Hawai‘i. Experimentally infected low elevation birds had lower mortality, lower reticulocyte counts during recovery from acute infection, lower weight loss, and no declines in food consumption relative to experimentally infected high elevation Hawai‘i ‘Amakihi in spite of similar intensities of infection. Emergence of this population provides an exceptional opportunity for determining physiological mechanisms and genetic markers associated with malaria tolerance that can be used to evaluate whether other, more threatened species have the capacity to adapt to this disease.

  5. Injection of fish protein solutions of fresh saithe (Pollachius virens) fillets studied by low field Nuclear Magnetic Resonance and physicochemical measurements.

    PubMed

    Gudjónsdóttir, María; Karlsdóttir, Magnea Gudrún; Arason, Sigurjón; Rustad, Turid

    2013-04-01

    Low field Nuclear Magnetic Resonance was used in comparison to yield and physicochemical measurements to assess the effects of salt and protein injection on the properties of saithe (Pollachius virens) fillets during chilled and frozen storage. Saithe fillets injected with various combinations of salt, homogenized fish proteins, gelatine and fish protein hydrolyzate, were compared to the properties of untreated fillets. Addition of salt or fish protein hydrolyzate resulted in increased yield after cooking and water holding capacity compared to other treatments. Transversal relaxation data fitting resulted in three water populations with relaxation times of 27-45 ms, 60-99 ms and 187-341 ms. Relaxation times and respective populations showed significant correlation to various physicochemical properties, that muscle water behaviour was changed by salt and protein injection and indicated protein denaturation during frozen storage. Fish protein hydrolyzate injected fillets were most stable through storage, while gelatine injected fillets were most denatured during frozen storage. PMID:24425912

  6. Effects of the pharmaceutical fluoxetine in spiked-sediments on feeding activity and growth of the polychaete Capitella teleta.

    PubMed

    Méndez, Nuria; Lacorte, Silvia; Barata, Carlos

    2013-08-01

    The marine-estuarine polychaete Capitella is an indicator of organic pollution and plays important roles in sewage waste cycling. The antidepressant fluoxetine can be accumulated in streams and sewage effluents and it could pose a hazard to infauna. Effects of fluoxetine on feeding and growth of Capitella teleta were investigated through the exposure to 0, 0.001, 0.03, 0.3 and 3.3 μg/g dry weight sediment-spiked fluoxetine during 18 days. No effects of fluoxetine concentrations were observed on egestion rates, body weight and size-specific egestion rates. Fluoxetine favoured the occurrence of males with abnormal genital spines. This suggests that fluoxetine can have important reproductive implications. Further studies are recommended to assess potential detrimental effects on benthic infauna inhabiting close to sewage treatment plants. PMID:23769338

  7. Influence of a burrowing, metal-tolerant polychaete on benthic metabolism, denitrification and nitrogen regeneration in contaminated estuarine sediments.

    PubMed

    Banks, Joanne L; Ross, D Jeff; Keough, Michael J; Macleod, Catriona K; Keane, John; Eyre, Bradley D

    2013-03-15

    We investigated the effects of the burrowing cirratulid polychaete Cirriformia filigera (Delle Chiaje, 1828) on benthic respiration and nitrogen regeneration in metal-contaminated estuarine sediments using laboratory mesocosms. C. filigera is a dominant component of assemblages in the most severely contaminated sediments within the Derwent estuary, southern Australia. In the presence of C. filigera sediment O2 consumption doubled, with approximately 55% of this increase due to their respiration and the remaining 45% attributable to oxidation reactions and increased microbial respiration associated with burrow walls. Combined NO3 and NO2 fluxes were unaffected. The addition of labile organic matter did not affect benthic fluxes, in the presence or absence of C. filigera, presumably due to the short timeframe of the experiment and naturally enriched test sediments. The results suggest that a combination of tolerance and burrowing activity enables this species to provide an ecosystem service in the removal of N from contaminated sites. PMID:23398743

  8. Identification and characterization of a twist ortholog in the polychaete annelid Platynereis dumerilii reveals mesodermal expression of Pdu-twist.

    PubMed

    Pfeifer, Kathrin; Schaub, Christoph; Wolfstetter, Georg; Dorresteijn, Adriaan

    2013-09-01

    The basic helix-loop-helix transcription factor twist plays a key role during mesoderm development in Bilateria. In this study, we identified a twist ortholog in the polychaete annelid Platynereis dumerilii and analyze its expression during larval development, postlarval growth up to the adult stage, and caudal regeneration after amputation of posterior segments. At late larval stages, Pdu-twist is expressed in the mesodermal anlagen and in developing muscles. During adulthood and caudal regeneration, Pdu-twist is expressed in the posterior growth zone, in mesodermal cells within the newly forming segments and budding parapodia. Our results indicate that Pdu-twist is involved in mesoderm formation during larval development, posterior growth, and caudal regeneration. PMID:23817621

  9. Ultrastructure of the genital organs in interstitial polychaetes. III. Penes and ejaculatory ducts in Hesionides arenaria (Hesionidae)

    NASA Astrophysics Data System (ADS)

    Westheide, W.

    1982-12-01

    The ejaculatory ducts of the two paired copulatory organs in the interstitial polychaete Hesionides arenaria are ciliated tubes, which open into simple, partly groove-like, non-stiffened penis papillae. The larger part of the ducts within the dorsal body wall is surrounded by circular muscle cells. Voluminous gland cell bodies lie between the pharynx-gut system and the body wall in the anterior part of the body; they extend anteriorly like long, thin necks, of which severl are always united in prominent strands. Their distal ends are expanded and penetrate the ducts. Six different types of glands can be distinguished according to the ultrastructure of their secretory granules. They produce the sheath of the double spermatophore or probably contain lytic enzymes that provide for the penetration of sperm into the body of the female. Differences in ultrastructure of the male organs in the interstitial genera Hesionides and Microphthalmus do not support the recent erection of the subfamily “Microphthalminae”.

  10. Freshwater polychaetes (Manayunkia speciosa) near the Detroit River, western Lake Erie: Abundance and life‐history characteristics

    USGS Publications Warehouse

    Schloesser, Donald W.; Malakauskas, David M.; Malakauskas, Sarah J.

    2016-01-01

    Freshwater polychaetes are relatively rare and little-studied members of the benthos of lakes and rivers. We studied one polychaete species (Manayunkia speciosa) in Lake Erie near the mouth of the Detroit River. Abundances at one site were determined between 1961 and 2013 and life‐history characteristics at two sites were determined seasonally (March–November) in 2009–2010 and 2012–2013. Life‐history characteristics included abundances, length‐frequency distributions, presence/absence of constructed tubes, sexual maturity, and number and maturation of young of year (YOY) in tubes. Long-term abundances decreased in successive time periods between 1961 and 2003 (mean range = 57,570 to 2583/m2) but few changes occurred between 2003 and 2013 (mean = 5007/m2; range/y = 2355–8216/m2). Seasonal abundances varied substantially between sites and years, but overall, abundances were low in March–April, high in May–August, and low in September–November. Although reproduction was continuous throughout warmer months, en masse recruitment, as revealed by length–frequency distributions, occurred in a brief period late‐June to mid-July, and possibly in early-September. All life history characteristics, including tube construction, were dependent on water temperatures (> 5 °C in spring and < 15 °C in fall). These results generally agree with and complement laboratory studies of M. speciosa in the Pacific Northwest where M. speciosa hosts parasites that cause substantial fish mortalities. Although abundance ofM. speciosa near the mouth of the Detroit River was 33-fold lower in 2013 than it was in 1961, this population has persisted for five decades and, therefore, has the potential to harbor parasites that may cause fish mortalities in the Great Lakes.

  11. Drilling Predation on Serpulid Polychaetes (Ditrupa arietina) from the Pliocene of the Cope Basin, Murcia Region, Southeastern Spain

    PubMed Central

    Martinell, Jordi; Kowalewski, Michał; Domènech, Rosa

    2012-01-01

    We report quantitative analyses of drilling predation on the free-living, tube-dwelling serpulid polychaete Ditrupa arietina from the Cope Cabo marine succession (Pliocene, Spain). Tubes of D. arietina are abundant in the sampled units: 9 bulk samples from 5 horizons yielded ∼5925 specimens of D. arietina. Except for fragmentation, tubes were well preserved. Complete specimens ranged from 3.1 to 13.4 mm in length and displayed allometric growth patterns, with larger specimens being relatively slimmer. Drilled Ditrupa tubes were observed in all samples. Drillholes, identified as Oichnus paraboloides, were characterized by circular to elliptical outline (drillhole eccentricity increased with its diameter), parabolic vertical profile, outer diameter larger than inner diameter, penetration of one tube wall only, narrow range of drill-hole sizes, and non-random (anterior) distribution of drillholes. A total of 233 drilled specimens were identified, with drilling frequencies varying across horizons from 2.7% to 21% (3.9% for pooled data). Many tube fragments were broken across a drillhole suggesting that the reported frequencies are conservative and that biologically-facilitated (drill-hole induced) fragmentation hampers fossil preservation of complete serpulid tubes. No failed or repaired holes were observed. Multiple complete drillholes were present (3.9%). Drilled specimens were significantly smaller than undrilled specimens and tube length and drill-hole diameter were weakly correlated. The results suggest that drillholes were produced by a size-selective, site-stereotypic predatory organism of unknown affinity. The qualitative and quantitative patterns reported here are mostly consistent with previous reports on recent and fossil Ditrupa and reveal parallels with drilling patterns documented for scaphopod mollusks, a group that is ecologically and morphologically similar to Ditrupa. Consistent with previous studies, the results suggest that free-dwelling serpulid

  12. Brefeldin A and monensin inhibit the D quadrant organizer in the polychaete annelids Arctonoe vittata and Serpula columbiana.

    PubMed

    Gonzales, Eric E; van der Zee, Maurijn; Dictus, Wim J A G; van den Biggelaar, Jo

    2007-01-01

    The D quadrant organizer is a developmental signaling center that is localized to the vegetal D quadrant in different spiral-cleaving lophotrochozoan embryos and may be homologous to axial organizing regions in other metazoans. Patterning by this organizing center creates a secondary developmental axis and is required for the transition from spiral to bilateral cleavage and later establishment of the adult body plan. Organizer specification in equal-cleaving embryos is thought to involve inductive interactions between opposing animal and vegetal blastomeres. To date, experimental demonstration of this interaction has been limited to molluscs and nemerteans. Here, we examine three families of equal-cleaving polychaete annelids for evidence of animal-vegetal contact. We find that contact is present in the polynoid, Arctonoe vittata, but is absent in the serpulid, Serpula columbiana, and in the oweniid, Oweniia fusiformis. To interfere with cell signaling during the period predicted for organizer specification and patterning in A. vittata and S. columbiana, we use two general inhibitors of protein processing and secretion: Brefeldin A (BFA) and monensin. In A. vittata, we detail subsequent embryonic and larval adult development and show that treatment with either chemical results in radialization of the embryo and subsequent body plan. Radialized larvae differentiate many larval and adult structures despite the loss of bilateral symmetry but do so in either a radially symmetric or four-fold radially symmetric fashion. Our results suggest that the D quadrant organizer is functionally conserved in equal-cleaving polychaetes, but that details of its specification, induction, and patterning have diverged relative to other spiral-cleaving phyla. PMID:17845514

  13. Muscle formation during embryogenesis of the polychaete Ophryotrocha diadema (Dorvilleidae) – new insights into annelid muscle patterns

    PubMed Central

    Bergter, Annette; Brubacher, John L; Paululat, Achim

    2008-01-01

    Background The standard textbook information that annelid musculature consists of oligochaete-like outer circular and inner longitudinal muscle-layers has recently been called into question by observations of a variety of complex muscle systems in numerous polychaete taxa. To clarify the ancestral muscle arrangement in this taxon, we compared myogenetic patterns during embryogenesis of Ophryotrocha diadema with available data on oligochaete and polychaete myogenesis. This work addresses the conflicting views on the ground pattern of annelids, and adds to our knowledge of the evolution of lophotrochozoan taxa. Results Somatic musculature in Ophryotrocha diadema can be classified into the trunk, prostomial/peristomial, and parapodial muscle complexes. The trunk muscles comprise strong bilateral pairs of distinct dorsal and ventral longitudinal strands. The latter are the first to differentiate during myogenesis. They originate within the peristomium and grow posteriorly through the continuous addition of myocytes. Later, the longitudinal muscles also expand anteriorly and form a complex arrangement of prostomial muscles. Four embryonic parapodia differentiate in an anterior-to-posterior progression, significantly contributing to the somatic musculature. Several diagonal and transverse muscles are present dorsally. Some of the latter are situated external to the longitudinal muscles, which implies they are homologous to the circular muscles of oligochaetes. These circular fibers are only weakly developed, and do not appear to form complete muscle circles. Conclusion Comparison of embryonic muscle patterns showed distinct similarities between myogenetic processes in Ophryotrocha diadema and those of oligochaete species, which allows us to relate the diverse adult muscle arrangements of these annelid taxa to each other. These findings provide significant clues for the interpretation of evolutionary changes in annelid musculature. PMID:18171469

  14. The biomagnification of PCBs, PCDDs, and PCDFs in a simplified laboratory food chain

    SciTech Connect

    Taplin, B.; Pruell, R.; McGovern, D.; McKinney, R.

    1995-12-31

    Polychaetes Nereis virens were exposed to contaminated sediment and fed to juvenile lobsters, Homarus americanus exposed to the same sediment for 112 days. Time series uptake and deputation measurements were made for lobster muscle and hepatopancreas. A nonlinear model (BIOFAC) was used to calculate uptake and deputation rate constants, bioaccumulation factors, and steady state concentrations for PCBS, PCDDS, and PCDFS. Biomagnification factors (BMFs), on a lipid weight basis, were calculated for both tissues. Lobsters accumulated PCDDS, PCDFS, and PCBs from contaminated sediment and food (polychaetes). Of the two tissues, lobster hepatopancreas showed the highest concentrations for all compounds analyzed. Of the PCDDs and PCDFs studied, only 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TCDD), 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF), 2,3,4,7,8-pentachlorodibenzofuran, and 1,2,3,4,7,8-hexachlorodibenzofuran were detected in lobster muscle and hepatopancreas tissues. Of the PCB congeners studied, 2,2{prime},4,4{prime},5,5{prime} hexachlorobiphenyl (UPAC No. 153) reached the highest concentration in lobster muscle and hepatopancreas. Lobsters also accumulated non-ortho substituted PCBs in both tissues. Biomagnification factors (BMFS) were calculated for lobster muscle and hepatopancreas on a lipid weight basis using steady-state concentrations. BMFs for lobster hepatopancreas were generally higher than those for muscle. Of the PCDDs and PCDFs studied, only 2,3,7,8-TCDD and 2,3,7,8-TCDF were biomagnified in lobster hepatopancreas and muscle compared with levels in the polychaetes. Selected PCB congeners were also biomagnified in both tissues. PCB congeners with log{sub 10} K{sub ow} values > 6.5 had higher BMFs for hepatopancreas tissue than compounds with lower K{sub ow`s}. No trend was evident regarding log{sub 10} K{sub ow} of PCBs and BMFs for lobster muscle.

  15. Polychaetes and oligochaetes associated with intertidal rocky shores in a semi-enclosed industrial and urban embayment, with the description of two new species

    NASA Astrophysics Data System (ADS)

    Parapar, Julio; Martínez-Ansemil, Enrique; Caramelo, Carlos; Collado, Rut; Schmelz, Rüdiger

    2009-12-01

    The species composition and relative abundance of the annelid benthic macrofauna (Polychaeta and Oligochaeta) inhabiting the rocky intertidal zone of the ria of Ferrol (Galicia, NW Spain) were studied during field collections, from 2000 to 2002. A total of 14,619 specimens (11,585 polychaetes belonging to 76 species and 24 families and 3,034 oligochaetes belonging to 18 species and two families) were collected from 98 quantitative samples taken from 13 sampling sites. The general spatial distribution of the annelid fauna reflects an increase of the diversity from the inner to the outer part of the ria. The general patterns found in the annelid composition suggest that the assemblages were dominated by oligochaetes in the inner sheltered sampling sites and polychaetes in the outer more exposed sites. Several faunistical and taxonomical remarks on selected species are presented. Two new species of oligochaetes are described: Coralliodrilus artabrensis sp. n. and Pirodrilus fungithecatus sp. n. (Naididae, Phallodrilinae). A new biological index, based on the oligochaete/polychaete ratio (O/P), is proposed as tool to evaluate environmental quality and to monitor future changes in the environment.

  16. Confocal analysis of nervous system architecture in direct-developing juveniles of Neanthes arenaceodentata (Annelida, Nereididae)

    PubMed Central

    2010-01-01

    polychaete Capitella, brain separation from a distinct epidermis occurs later in N. arenaceodentata, indicating different mechanisms of prostomial development. Our observations of parapodial innervation and the absence of lateral nerves in N. arenaceodentata are similar to a 19th century study of Alitta virens (formerly Nereis/Neanthes virens) but contrast with a more recent study that describes a single parapodial nerve pattern and lateral nerve presence in A. virens and two other genera. The latter study apparently does not account for among-nereidid variation in these major neural features. PMID:20553614

  17. Functional characterization of a plant-like sucrose transporter from the beneficial fungus Trichoderma virens. Regulation of the symbiotic association with plants by sucrose metabolism inside the fungal cells.

    PubMed

    Vargas, Walter A; Crutcher, Frankie K; Kenerley, Charles M

    2011-02-01

    • Sucrose exuded by plants into the rhizosphere is a crucial component for the symbiotic association between the beneficial fungus Trichoderma and plant roots. In this article we sought to identify and characterize the molecular basis of sucrose uptake into the fungal cells. • Several bioinformatics tools enabled us to identify a plant-like sucrose transporter in the genome of Trichoderma virens Gv29-8 (TvSut). Gene expression profiles in the fungal cells were analyzed by Northern blotting and quantitative real-time PCR (qRT-PCR). Biochemical and physiological studies were conducted on Gv29-8 and fungal strains impaired in the expression of TvSut. • TvSut exhibits biochemical properties similar to those described for sucrose symporters from plants. The null expression of tvsut caused a detrimental effect on fungal growth when sucrose was the sole source of carbon in the medium, and also affected the expression of genes involved in the symbiotic association. • Similar to plants, T. virens contains a highly specific sucrose/H(+) symporter that is induced in the early stages of root colonization. Our results suggest an active sucrose transference from the plant to the fungal cells during the beneficial associations. In addition, our expression experiments suggest the existence of a sucrose-dependent network in the fungal cells that regulates the symbiotic association.

  18. Alteration of organic matter during infaunal polychaete gut passage and links to sediment organic geochemistry. Part II: Fatty acids and aldoses

    NASA Astrophysics Data System (ADS)

    Woulds, Clare; Middelburg, Jack J.; Cowie, Greg L.

    2014-07-01

    The activities of sediment-dwelling fauna are known to influence the rates of and pathways through which organic matter is cycled in marine sediments, and thus to influence eventual organic carbon burial or decay. However, due to methodological constraints, the role of faunal gut passage in determining the subsequent composition and thus degradability of organic matter is relatively little studied. Previous studies of organic matter digestion by benthic fauna have been unable to detect uptake and retention of specific biochemicals in faunal tissues, and have been of durations too short to fit digestion into the context of longer-term sedimentary degradation processes. Therefore this study aimed to investigate the aldose and fatty acid compositional alterations occurring to organic matter during gut passage by the abundant and ubiquitous polychaetes Hediste diversicolor and Arenicola marina, and to link these to longer-term changes typically observed during organic matter decay. This aim was approached through microcosm experiments in which selected polychaetes were fed with 13C-labelled algal detritus, and organisms, sediments, and faecal pellets were sampled at three timepoints over ∼6 weeks. Samples were analysed for their 13C-labelled aldose and fatty acid contents using GC-MS and GC-IRMS. Compound-selective net accumulation of biochemicals in polychaete tissues was observed for both aldoses and fatty acids, and the patterns of this were taxon-specific. The dominant patterns included an overall loss of glucose and polyunsaturated fatty acids; and preferential preservation or production of arabinose, microbial compounds (rhamnose, fucose and microbial fatty acids), and animal-synthesised fatty acids. These patterns may have been driven by fatty acid essentiality, preferential metabolism of glucose, and A. marina grazing on bacteria. Fatty acid suites in sediments from faunated microcosms showed greater proportions of saturated fatty acids and bacterial markers

  19. Lethal and sub-lethal responses of the biogenic reef forming polychaete Sabellaria alveolata to aqueous chlorine and temperature.

    PubMed

    Last, K S; Hendrick, V J; Beveridge, C M; Roberts, D A; Wilding, T A

    2016-06-01

    Sabellaria alveolata, a reef-forming marine polychaete, was exposed to aqueous chlorine which is routinely used as an anti-fouling agent in power station cooling water. Worms were treated to a range of chlorination levels (0, 0.02, 0.1 and 0.5 mg l(-1) Total Residual Oxidant referred to as control, low, intermediate and high TRO) at mean and maximum summer temperatures (18 and 23 °C respectively). Overall mortality was relatively low, however a combination of high temperature and intermediate and high TRO resulted in a significant increase in mortality compared to the control and low TRO treatments. In contrast the extension of dwelling tubes was reduced at high TRO, but increased at low and intermediate TRO levels relative to the controls independent of temperature. Finally, tube strength was found to decrease with increasing TRO, again independent of temperature. On the basis of these findings, S. alveolata can be considered tolerant of one month exposures to low TRO at water temperatures up to and including the summer maxima for southern UK waters. However, at higher TRO levels and during warm weather, high mortality would be predicted. PMID:27085057

  20. Phylogeography and reproductive variation of the poecilogonous polychaete Boccardia proboscidea (Annelida: Spionidae) along the West Coast of North America.

    PubMed

    Oyarzun, Fernanda X; Mahon, Andrew R; Swalla, Billie J; Halanych, Kenneth M

    2011-01-01

    The ability to produce more than one kind of offspring, or poecilogony, is a striking example of reproductive variability. Traditionally, larval nutrition has been classified as a dichotomy: if offspring obtain nutrition from their mothers (lecithotrophy), there is lower fecundity and greater chance of offspring survival than when they get their nutrition from plankton (planktotrophy). The polychaete Boccardia proboscidea (Spionidae) produces both types of embryos using three different reproductive strategies. In this study, we examined the roles of genetic history and phenotypic plasticity on explaining natural variation in B. proboscidea along the Pacific coast of the United States using two genetic mitochondrial markers, 16S rDNA and Cyt b, and common garden experiments. These data show a single North American West Coast network that is structured, geographically, by the well-documented biogeographic break near Point Conception, California. The southern group within this network covers a smaller range, but has larger haplotype diversity, than the northern group. Some individuals differing in reproductive type had the same haplotype, indicating independence of these features; however, differences between laboratory and field data suggest additional geographic variation within one of the reproductive types. Females from higher latitudes provide offspring with larger supplies of extra embryonic nutrition than females from southern latitudes. Results herein suggest that both genetic history and developmental plasticity are playing a role in the maintenance of this reproductive polymorphism.

  1. Bacterial community succession and chemical profiles of subtidal biofilms in relation to larval settlement of the polychaete Hydroides elegans.

    PubMed

    Chung, Hong Chun; Lee, On On; Huang, Yi-Li; Mok, Siu Yan; Kolter, Roberto; Qian, Pei-Yuan

    2010-06-01

    Earlier studies have shown that biofilms can mediate the larval settlement of the polychaete Hydroides elegans and that changes in the bacterial community structure and density of biofilms often alter the larval settlement response. However, the chemical cues that mediate this response remain unknown. In this study, both successional changes in the bacterial community structure and the chemical profiles of subtidal biofilms are described and related to the larval settlement response. Multispecies biofilms were developed on polystyrene Petri dishes and granite rock in the subtidal zone over a period of 20 days. The effects of the substratum and age on the bacterial community structure and chemical profiles of the biofilms were evaluated with two molecular methods (microarray (PhyloChip) and denaturing gradient gel electrophoresis) and with gas chromatography-mass spectrometry, respectively. Both age and substratum altered the bacterial community structures and chemical profiles of the biofilms. Age had a greater effect in shaping the bacterial community structure than did the substratum. In contrast, the type of substratum more strongly affected the chemical profile. Extracts of biofilms of different ages, which developed on different substrata, were tested for the settlement of H. elegans larvae. The extracts induced larval settlement in a biofilm-age-dependent manner, and extracts originating from different substrata of the same age showed no differences in larval settlement. Our results suggest that the larval settlement response cannot be predicted by the overall chemical composition of the biofilm alone.

  2. Effect of mercury on taurine transport by the red blood cells of the marine polychaete, Glycera dibranchiata

    SciTech Connect

    Chen, C.W.; Preston, R.L.

    1987-08-01

    The objective of this study was to characterize the effects of heavy metal exposure on the transport of the amino acid, /sup 14/C-taurine, by the hemoglobin containing coelomocytes (red blood cells) of the marine polychaete, Glycera dibranchiata. Glycera has been used previously in studies on heavy metal absorption. Glycera red cells (RBCs) were used for this study because they contain a high concentration of taurine (190 mM) which has been implicated as a major osmolyte in cellular volume regulation in marine invertebrates. Taurine also appears to participate in osmoregulation of mammalian heart and brain tissue. The coelomic fluid bathing Glycera RBCs typically contains taurine at considerably lower concentrations (0.2 mM). The standing gradients (intracellular conc./extracellular conc.) for amino acids ranges from 40:1 for lysine to 950:1 for taurine. Preliminary experiments demonstrated that the maintenance of the large standing gradient for taurine was apparently due to the presence of a specific Na and Cl dependent taurine transport system in these cells. The fact that Glycera RBCs actively maintain large taurine gradients suggests that this tissue should be an excellent one to use in analysis of the mechanisms of heavy metal interaction with taurine transport systems.

  3. Biosurfactant activity, heavy metal tolerance and characterization of Joostella strain A8 from the Mediterranean polychaete Megalomma claparedei (Gravier, 1906).

    PubMed

    Rizzo, Carmen; Michaud, Luigi; Graziano, Marco; De Domenico, Emilio; Syldatk, Christoph; Hausmann, Rudolf; Lo Giudice, Angelina

    2015-08-01

    The effect of heavy metals on the activity of biosurfactants produced by Joostella strain A8 from the polychaete Megalomma claparedei was investigated. Biosurfactant activity was first improved by evaluating the influence of abiotic parameters. Higher E(24) indices were achieved at 25 °C in mineral salt medium supplemented with 2 % glucose, 3 % sodium chloride (w/v) and 0.1 % ammonium chloride (w/v). Considerable surface tension reduction was never recorded. Heavy metal tolerance was preliminarily assayed by plate diffusion method resulting in the order of toxicity Cd > Cu > Zn. The activity of biosurfactants was then evaluated in the presence of heavy metals at different concentrations in liquid cultures that were incubated under optimal conditions for biosurfactant activity. The production of stable emulsions resulted generally higher in the presence of metals. These findings suggest that biosurfactant production could represent a bacterial adaptive strategy to defend cells from a stress condition derived from heavy metals in the bulk environment. PMID:26059469

  4. Assessment of field-related influences on polychlorinated biphenyl exposures and sorbent amendment using polychaete bioassays and passive sampler measurements

    USGS Publications Warehouse

    Janssen, E.M.; Oen, A.M.; Luoma, S.N.; Luthy, R.G.

    2011-01-01

    Field-related influences on polychlorinated biphenyl (PCB) exposure were evaluated by employing caged deposit-feeders, Neanthes arenaceodentata, along with polyoxymethylene (POM) samplers using parallel in situ and ex situ bioassays with homogenized untreated or activated carbon (AC) amended sediment. The AC amendment achieved a remedial efficiency in reducing bioaccumulation by 90% in the laboratory and by 44% in the field transplants. In situ measurements showed that PCB uptake by POM samplers was greater for POM placed in the surface sediment compared with the underlying AC amendment, suggesting that tidal exchange of surrounding material with similar PCB availability as untreated sediment was redeposited in the cages. Polychlorinated biphenyls bioaccumulation with caged polychaetes from untreated sediment was half as large under field conditions compared with laboratory conditions. A biodynamic model was used to confirm and quantify the different processes that could have influenced these results. Three factors appeared most influential in the bioassays: AC amendment significantly reduces bioavailability under laboratory and field conditions; sediment deposition within test cages in the field partially masks the remedial benefit of underlying AC-amended sediment; and deposit-feeders exhibit less PCB uptake from untreated sediment when feeding is reduced. Ex situ and in situ experiments inevitably show some differences that are associated with measurement methods and effects of the environment. Parallel ex situ and in situ bioassays, passive sampler measurements, and quantifying important processes with a model can tease apart these field influences. ?? 2010 SETAC.

  5. The effects of water acidification, temperature and salinity on the regenerative capacity of the polychaete Diopatra neapolitana.

    PubMed

    Pires, Adília; Figueira, Etelvina; Moreira, Anthony; Soares, Amadeu M V M; Freitas, Rosa

    2015-05-01

    Changes in seawater pH, temperature and salinity are expected to occur in the near future, which can be a threat to aquatic systems, mainly for marine coastal areas, and their inhabiting species. Hence, the present study proposes to evaluate the effects of temperature shifts, pH decrease and salinity changes in the tissue's regenerative capacity of the polychaete Diopatra neapolitana. This study evidenced that D. neapolitana individuals exposed to lower pH exhibited a significantly lower capacity to regenerate their body, while with the increase of temperature individuals showed a higher capacity to regenerate their tissues. Furthermore, the present work demonstrated that individuals exposed to salinities 28 and 35 did not present significant differences between them, while salinities 21 and 42 negatively influenced the regenerative capacity of D. neapolitana. At the end of regeneration, comparing all conditions, high salinity (42) seemed to have a greater impact on the regenerative capacity of individuals than the other factors, since under this condition individuals took longer to completely regenerate. Overall, this study demonstrated that variations in abiotic factors can strongly affect D. neapolitana's performance. PMID:25756899

  6. Ocean acidification increases copper toxicity to the early life history stages of the polychaete Arenicola marina in artificial seawater.

    PubMed

    Campbell, Anna L; Mangan, Stephanie; Ellis, Robert P; Lewis, Ceri

    2014-08-19

    The speciation and therefore bioavailability of the common pollutant copper is predicted to increase within the pH range anticipated under near-future ocean acidification (OA), hence the potential exists for copper toxicity to marine organisms to also increase. We investigated the impact of OA (seawater pH values of 7.77 (pCO2 1400 μatm) and 7.47 (pCO2 3000 μatm)) upon copper toxicity responses in early life history stages of the polychaete Arenicola marina and found both synergistic and additive toxicity effects of combined exposures depending on life history stage. The toxicity of copper on sperm DNA damage and early larval survivorship was synergistically increased under OA conditions. Larval survival was reduced by 24% when exposed to both OA and copper combined compared to single OA or copper exposures. Sperm motility was negatively affected by both OA and copper singularly with additive toxicity effects of the two stressors when combined. Fertilization success was also negatively affected by both OA and copper individually, but no additive effects when exposed as combined stressors were present for this stage. These findings add to the growing body of evidence that OA will act to increase the toxicity of copper to marine organisms, which has clear implications for coastal benthic ecosystems suffering chronic metal pollution as pCO2 levels rise and drive a reduction in seawater pH.

  7. Alien reef-building polychaete drives long-term changes in invertebrate biomass and diversity in a small, urban estuary

    NASA Astrophysics Data System (ADS)

    McQuaid, K. A.; Griffiths, C. L.

    2014-02-01

    Two of the greatest threats to native biodiversity are the construction of artificial structures in natural environments and the introduction of invasive species. As the development and urbanisation of estuaries continues at an increasing rate worldwide, these environments are being simultaneously affected by these threats. This study quantifies the spread of an invasive reef-building polychaete, Ficopomatus enigmaticus, in a small, highly manipulated urban estuary in South Africa and investigates its role as an ecosystem engineer. Anthropogenic changes to the Zandvlei Estuary, including construction of a rubble weir and canalisation near the estuary mouth, construction of an extensive marina development and hardening of the banks with concrete, have facilitated the expansion of F. enigmaticus. The standing stock of F. enigmaticus increased from 13.69 t, as measured in 1986, to 50.03 t in 2012, due both to increase in the total area colonised and standing stock per m2. Since F. enigmaticus reefs support a greater biomass of infauna than adjacent sandy areas, total invertebrate biomass in the estuary is estimated to have increased from less than 0.30 t in 1942, to over 56.80 t in 2012, due mainly to hardening of banks in parts of the main estuary with concrete and construction of a marina system. A positive correlation between reef mass and infaunal biomass, density and diversity was also found.

  8. Rapid treatment of vessels fouled with an invasive polychaete, Sabella spallanzanii, using a floating dock and chlorine as a biocide.

    PubMed

    Morrisey, Donald J; Depree, Craig V; Hickey, Christopher W; McKenzie, Don S; Middleton, Irene; Smith, Matt D; Stewart, Michael; Thompson, Karen J

    2016-01-01

    Chlorine solution was added to the water encapsulated within a proprietary 'floating dock' to treat a vessel infested with the invasive polychaete Sabella spallanzanii. The chlorine was added as sodium dichloroisocyanurate ('dichlor') at an initial concentration of 200 mg l(-1) of free available chlorine (FAC). This concentration killed 99% of S. spallanzanii in their tubes during a 4-h exposure in laboratory tests (EC99 160 mg FAC l(-1)). The concentration of FAC in the floating dock declined to ~50 mg l(-1) after 4 h and < 10 mg l(-1) after 16 h. Residual FAC was neutralised with thiosulphate at completion of exposure. A sample of 30 S. spallanzanii individuals collected from the hull after treatment all showed morphological damage and 28 showed no response to touch. Re-examination of the hull after 6 d found no live worms or other fouling organisms. This method provides a cost-effective, rapid means of treating hull fouling. PMID:26795943

  9. Influence of reactive sulfide (AVS) and supplementary food on Ag, Cd and Zn bioaccumulation in the marine polychaete Neanthes arenaceodentata

    USGS Publications Warehouse

    Lee, J.-S.; Lee, B.-G.; Yoo, H.; Koh, C.-H.; Luoma, S.N.

    2001-01-01

    A laboratory bioassay determined the relative contribution of various pathways of Ag, Cd and Zn bioaccumulation in the marine polychaete Neanthes arenaceodentata exposed to moderately contaminated sediments. Juvenile worms were exposed for 25 d to experimental sediments containing 5 different reactive sulfide (acid volatile sulfides, AVS) concentrations (1 to 30 ??mol g-1), but with constant Ag, Cd, and Zn concentrations of 0.1, 0.1 and 7 ??mol g-1, respectively. The sediments were supplemented with contaminated food (TetraMin??) containing 3 levels of Ag-Cd-Zn (uncontaminated, 1?? or 5??1 metal concentrations in the contaminated sediment). The results suggest that bioaccumulation of Ag, Cd and Zn in the worms occurred predominantly from ingestion of contaminated sediments and contaminated supplementary food. AVS or dissolved metals (in porewater and overlying water) had a minor effect on bioaccumulation of the 3 metals in most of the treatments. The contribution to uptake from the dissolved source was most important in the most oxic sediments, with maximum contributions of 8% for Ag, 30% for Cd and 20% for Zn bioaccumulation. Sediment bioassays where uncontaminated supplemental food is added could seriously underestimate metal exposures in an equilibrated system; N. arenaceodentata feeding on uncontaminated food would be exposed to 40-60% less metal than if the food source was equilibrated (as occurs in nature). Overall, the results show that pathways of metal exposure are dynamically linked in contaminated sediments and shift as external geochemical characteristics and internal biological attributes vary.

  10. Spatial and diurnal distribution of invertebrate and fish fauna of a Zostera marina bed and nearby unvegetated sediments in Damariscotta River, Maine (USA)

    NASA Astrophysics Data System (ADS)

    Mattila, Johanna; Chaplin, Glen; Eilers, Michele R.; Heck, Kenneth L.; O'Neal, Jonathan P.; Valentine, John F.

    1999-06-01

    Fish, epibenthos and macroinfauna were collected in a Zostera marina bed and nearby unvegetated sediments in the estuary of the Damariscotta River, on the mid-coast of Maine. Samples of epibenthic fauna and fish were collected at low tides both during day and night, and samples of infauna at low tides during the day. The mean density of Zostera shoots in the study area was 335 m -2. Abundance and species number of fish were greater at night than during the day and greater in eelgrass beds ( Z. marina) than in unvegetated habitats. Daytime fish collections were dominated by Atlantic silversides ( Medinia medinia), while juvenile winter flounder ( Pseudopleuronectes americanus) dominated night collections. Also Zostera-associated epifaunal abundances and number of species were significantly higher at night than during the day. Mysis stenolepis, Idotea balthica and Littorina obtusata were dominant species in the epifauna samples. Of the total of 37 invertebrate species encountered, only five occurred both in the infaunal and epifaunal samples. Nineteen different taxa were collected from the benthic core samples. The most abundant invertebrate infaunal taxa were sipunculids, the polychaete Nereis virens, and oligochaetes. Infaunal invertebrate abundances and species diversity were significantly higher in eelgrass beds than in unvegetated sediments. The abundance and number of species of benthic invertebrates were also positively correlated to seagrass biomass. Community diversity values ( H') were relatively low but fit well in the general pattern of decreasing diversity towards northern latitudes.

  11. Characterization and Recombinant Expression of Terebrid Venom Peptide from Terebra guttata.

    PubMed

    Moon, John; Gorson, Juliette; Wright, Mary Elizabeth; Yee, Laurel; Khawaja, Samer; Shin, Hye Young; Karma, Yasmine; Musunri, Rajeeva Lochan; Yun, Michelle; Holford, Mande

    2016-03-03

    Venom peptides found in terebrid snails expand the toolbox of active compounds that can be applied to investigate cellular physiology and can be further developed as future therapeutics. However, unlike other predatory organisms, such as snakes, terebrids produce very small quantities of venom, making it difficult to obtain sufficient amounts for biochemical characterization. Here, we describe the first recombinant expression and characterization of terebrid peptide, teretoxin Tgu6.1, from Terebra guttata. Tgu6.1 is a novel forty-four amino acid teretoxin peptide with a VI/VII cysteine framework (C-C-CC-C-C) similar to O, M and I conotoxin superfamilies. A ligation-independent cloning strategy with an ompT protease deficient strain of E. coli was employed to recombinantly produce Tgu6.1. Thioredoxin was introduced in the plasmid to combat disulfide folding and solubility issues. Specifically Histidine-6 tag and Ni-NTA affinity chromatography were applied as a purification method, and enterokinase was used as a specific cleavage protease to effectively produce high yields of folded Tgu6.1 without extra residues to the primary sequence. The recombinantly-expressed Tgu6.1 peptide was bioactive, displaying a paralytic effect when injected into a Nereis virens polychaete bioassay. The recombinant strategy described to express Tgu6.1 can be applied to produce high yields of other disulfide-rich peptides.

  12. Characterization and Recombinant Expression of Terebrid Venom Peptide from Terebra guttata

    PubMed Central

    Moon, John; Gorson, Juliette; Wright, Mary Elizabeth; Yee, Laurel; Khawaja, Samer; Shin, Hye Young; Karma, Yasmine; Musunri, Rajeeva Lochan; Yun, Michelle; Holford, Mande

    2016-01-01

    Venom peptides found in terebrid snails expand the toolbox of active compounds that can be applied to investigate cellular physiology and can be further developed as future therapeutics. However, unlike other predatory organisms, such as snakes, terebrids produce very small quantities of venom, making it difficult to obtain sufficient amounts for biochemical characterization. Here, we describe the first recombinant expression and characterization of terebrid peptide, teretoxin Tgu6.1, from Terebra guttata. Tgu6.1 is a novel forty-four amino acid teretoxin peptide with a VI/VII cysteine framework (C–C–CC–C–C) similar to O, M and I conotoxin superfamilies. A ligation-independent cloning strategy with an ompT protease deficient strain of E. coli was employed to recombinantly produce Tgu6.1. Thioredoxin was introduced in the plasmid to combat disulfide folding and solubility issues. Specifically Histidine-6 tag and Ni-NTA affinity chromatography were applied as a purification method, and enterokinase was used as a specific cleavage protease to effectively produce high yields of folded Tgu6.1 without extra residues to the primary sequence. The recombinantly-expressed Tgu6.1 peptide was bioactive, displaying a paralytic effect when injected into a Nereis virens polychaete bioassay. The recombinant strategy described to express Tgu6.1 can be applied to produce high yields of other disulfide-rich peptides. PMID:26950153

  13. Importance of black carbon in distribution and bioaccumulation models of polycyclic aromatic hydrocarbons in contaminated marine sediments.

    PubMed

    Vinturella, Amy E; Burgess, Robert M; Coull, Brent A; Thompson, Kimberly M; Shine, James P

    2004-11-01

    The roles and relative importance of nonpyrogenic organic carbon (NPOC) and black carbon (BC) as binding phases of polycyclic aromatic hydrocarbons (PAHs) were assessed by their ability to estimate pore water concentrations and biological uptake in various marine sediments. Sediment bioaccumulation tests were performed with the marine polychaete Nereis virens, using a polyethylene device to estimate pore water concentrations of PAHs. Using existing partitioning data for pyrene and phenanthrene, it was found that the traditional Equilibrium Partitioning model, which assumes all organic carbon is NPOC (EqP(OC)), overestimated the measured pore water concentrations in the test sediments by one to three orders of magnitude. Instead, the measured pore water concentrations were better predicted from a distribution scenario that uses both BC and NPOC (EqP(NPOc,BC)) When comparing actual worm body burdens of pyrene and phenanthrene with the two model estimates of worm tissue concentrations, the EqP(OC) model tended to overestimate actual body burdens by three orders of magnitude, while the EqP(NPOC,BC) model came much closer to the true body burden values. The observed distribution of PAHs in the test sediments was used to calculate BC partition coefficients for five PAHs, which were one to two orders of magnitude higher than their corresponding organic carbon-normalized distribution coefficients, or K(OC)s. Together, these results suggest that, in certain situations, adding black carbon to distribution models may be necessary to predict accurately the bioavailability of PAHs.

  14. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (North Atlantic): Sandworm and bloodworm

    SciTech Connect

    Wilson, W.H., Jr.; Ruff, R.E.; Moran, D.

    1988-04-01

    Species profiles are literature summaries of the taxonomy, morphology, range, life history, and environmental requirements of coastal aquatic species. They are prepared to assist in environmental impact assessment. The sandworm (Nereis virens) is a commercially valuable baitworm, reaching lengths of 30 cm. Most worms live 4 or 5 years. Males swarm in the water column before spawning in the females' burrows. Both males and females die after spawning. A planktonic larval phase is either brief or lacking. Sandworms are omnivorous. They can significantly reduce the abundance of smaller infaunal organisms. Predators on sandworms include bloodworms and gulls. Physiological tolerances are broad although most worms are found in fine sand with water of high salinity. Sandworms have been the subject of much toxicological research and readily adapt to laboratory conditions. The bloodworm (Glycera dibranchiata), attaining lengths of 40 cm, is also an important baitworm. Its maximum life span is 5 years. Spawning occurs in the water column with both males and females dying after spawning. Bloodworms are primarily predators, preying on certain species of polychaetes and crustaceans, although they are capable of digesting detritus. Bloodworms appear to have few predators. Bloodworms possess at least two types of hemoglobin, permitting them to tolerate a wide range of oxygen tensions. 177 refs., 4 figs.

  15. Revealing polychaetes invasion patterns: Identification, reproduction and potential risks of the Korean ragworm, Perinereis linea (Treadwell), in the Western Mediterranean

    NASA Astrophysics Data System (ADS)

    Arias, Andrés; Richter, Alexandra; Anadón, Nuria; Glasby, Christopher J.

    2013-10-01

    An established population of the polychaetous annelid Perinereis linea (Treadwell) is reported for the first time outside its native distribution range (NW Pacific). This exotic worm has reached the Western Mediterranean (Mar Menor lagoon) via importing live fishing-bait as it is commonly used by anglers in Mar Menor lagoon, an area largely used for recreational fishing. To avoid confusion with other related species, and because the scientific name has been in synonymy for many years, P. linea is redescribed and illustrated. We focus on the reproductive biology and ecology of P. linea to help to understand its introduction, naturalization and spread along this coastal lagoon. Comparison between the Mediterranean population with a native population from South Korea revealed that the species exhibits a great reproductive plasticity and adaptability, which depends on the environmental conditions. Perinereis linea can reproduce after acquiring the epitokous form or prior to complete epitokal modification. In the Mar Menor lagoon population females release eggs asynchronically without completing epitokal modifications. However, under particular laboratory conditions females produce eggs synchronically and release them after complete epitokal transformations. Fertilization can occur internally in the female coelom, and females release zygotes and larvae through openings in their body walls; they are then incubated in gelatinous masses attached to the female parapodia. The sperm morphology is of the ent-aquasperm type. The eggs and larvae are attacked by symbiotic ciliate protozoa that feed on their yolk reserves. These foreign ciliates may act as carriers of disease in native beachworms and constitute an important risk for the ecosystem health. Finally, we provide recommendations on the prevention of the adverse effects that this exotic ragworm can cause in receiving ecosystems.

  16. First record of the polychaete Ficopomatus uschakovi (Pillai, 1960) (Annelida, Serpulidae) in the Colombian Caribbean, South America

    PubMed Central

    Arteaga-Flórez, Catalina; Fernández-Rodríguez, Vanessa; Londoño-Mesa, Mario H.

    2014-01-01

    Abstract The genus Ficopomatus (Serpulidae) consists of sessile, tubicolous polychaete annelid worms that may colonize a diversity of substrata, and tolerate considerable variations in salinity. Thus, members of this genus, including Ficopomatus uschakovi, in some cases are exotic and maybe invasive. The purpose of our research was to collect and identify marine organisms associated with the submerged roots of mangrove trees in the Gulf of Urabá, Colombian Caribbean, South America. Within the Gulf, there is a well-developed forest of the Red Mangrove, Rhizophora mangle, along the margins of El Uno Bay. We sampled the roots of R. mangle from five stations of the bay, and we identified specimens of F. uschakovi from each of those stations. Ficopomatus uschakovi was found to be more abundant in regions of the bay that exhibit the lowest salinity. Based on a morphological comparison of the present specimens with the original species description, revised descriptions, and other records from the Indo-West Pacific, Mexican Pacific, and Venezuelan and Brazilian Caribbean, we suggest that F. uschakovi has a broader geographical distribution. Furthermore, because of this broad distribution, and the observed tolerance for low salinity in our study, we also suggest that F. uschakovi is a euryhaline species. It is also likely that F. uschakovi will be found in other localities in the Gulf of Urabá, and in other regions of the Colombian Caribbean. Thus, this record extends the distribution of the species to the Colombian Caribbean, giving the species a continuous distribution across the northern coast of South America. PMID:24493951

  17. The development of the larval nervous system, musculature and ciliary bands of Pomatoceros lamarckii (Annelida): heterochrony in polychaetes

    PubMed Central

    McDougall, Carmel; Chen, Wei-Chung; Shimeld, Sebastian M; Ferrier, David EK

    2006-01-01

    Background To understand the evolution of animals it is essential to have taxon sampling across a representative spread of the animal kingdom. With the recent rearrangement of most of the Bilateria into three major clades (Ecdysozoa, Lophotrochozoa and Deuterostomia) it has become clear that the Lophotrochozoa are relatively poorly represented in our knowledge of animal development, compared to the Ecdysozoa and Deuterostomia. We aim to contribute towards redressing this balance with data on the development of the muscular, nervous and ciliary systems of the annelid Pomatoceros lamarckii (Serpulidae). We compare our data with other lophotrochozoans. Results P. lamarckii develops locomotory and feeding structures that enable it to become a swimming, planktotrophic larva within 24 hours. Formation of the trochophore includes development of a prototroch, metatroch and neurotroch, development of apical and posterior nervous elements at similar times, and development of musculature around the ciliary bands and digestive tract prior to development of any body wall muscles. The adult nervous and muscular systems are essentially preformed in the late larva. Interestingly, the muscular systems of the larvae and juvenile worms do not include the circular muscles of the body wall, which are considered to be plesiomorphic for annelids, although the possibility that circular muscles develop after these stages cannot be ruled out at this point. Conclusion A comparison between polychaetes shows variability in the timing (heterochrony) of development of body wall muscles and elements of the nervous system. These heterochronies are one route for evolution of different life history strategies, such as adaptations to feeding requirements. PMID:17032451

  18. First record of the polychaete Ficopomatus uschakovi (Pillai, 1960) (Annelida, Serpulidae) in the Colombian Caribbean, South America.

    PubMed

    Arteaga-Flórez, Catalina; Fernández-Rodríguez, Vanessa; Londoño-Mesa, Mario H

    2014-01-01

    The genus Ficopomatus (Serpulidae) consists of sessile, tubicolous polychaete annelid worms that may colonize a diversity of substrata, and tolerate considerable variations in salinity. Thus, members of this genus, including Ficopomatus uschakovi, in some cases are exotic and maybe invasive. The purpose of our research was to collect and identify marine organisms associated with the submerged roots of mangrove trees in the Gulf of Urabá, Colombian Caribbean, South America. Within the Gulf, there is a well-developed forest of the Red Mangrove, Rhizophora mangle, along the margins of El Uno Bay. We sampled the roots of R. mangle from five stations of the bay, and we identified specimens of F. uschakovi from each of those stations. Ficopomatus uschakovi was found to be more abundant in regions of the bay that exhibit the lowest salinity. Based on a morphological comparison of the present specimens with the original species description, revised descriptions, and other records from the Indo-West Pacific, Mexican Pacific, and Venezuelan and Brazilian Caribbean, we suggest that F. uschakovi has a broader geographical distribution. Furthermore, because of this broad distribution, and the observed tolerance for low salinity in our study, we also suggest that F. uschakovi is a euryhaline species. It is also likely that F. uschakovi will be found in other localities in the Gulf of Urabá, and in other regions of the Colombian Caribbean. Thus, this record extends the distribution of the species to the Colombian Caribbean, giving the species a continuous distribution across the northern coast of South America. PMID:24493951

  19. First record of the polychaete Ficopomatus uschakovi (Pillai, 1960) (Annelida, Serpulidae) in the Colombian Caribbean, South America.

    PubMed

    Arteaga-Flórez, Catalina; Fernández-Rodríguez, Vanessa; Londoño-Mesa, Mario H

    2014-01-01

    The genus Ficopomatus (Serpulidae) consists of sessile, tubicolous polychaete annelid worms that may colonize a diversity of substrata, and tolerate considerable variations in salinity. Thus, members of this genus, including Ficopomatus uschakovi, in some cases are exotic and maybe invasive. The purpose of our research was to collect and identify marine organisms associated with the submerged roots of mangrove trees in the Gulf of Urabá, Colombian Caribbean, South America. Within the Gulf, there is a well-developed forest of the Red Mangrove, Rhizophora mangle, along the margins of El Uno Bay. We sampled the roots of R. mangle from five stations of the bay, and we identified specimens of F. uschakovi from each of those stations. Ficopomatus uschakovi was found to be more abundant in regions of the bay that exhibit the lowest salinity. Based on a morphological comparison of the present specimens with the original species description, revised descriptions, and other records from the Indo-West Pacific, Mexican Pacific, and Venezuelan and Brazilian Caribbean, we suggest that F. uschakovi has a broader geographical distribution. Furthermore, because of this broad distribution, and the observed tolerance for low salinity in our study, we also suggest that F. uschakovi is a euryhaline species. It is also likely that F. uschakovi will be found in other localities in the Gulf of Urabá, and in other regions of the Colombian Caribbean. Thus, this record extends the distribution of the species to the Colombian Caribbean, giving the species a continuous distribution across the northern coast of South America.

  20. Spatio-temporal changes of marine macrobenthic community in sub-tropical waters upon recovery from eutrophication. II. Life-history traits and feeding guilds of polychaete community.

    PubMed

    Cheung, S G; Lam, N W Y; Wu, R S S; Shin, P K S

    2008-02-01

    A two-year study was conducted in the vicinity of a harbour in sub-tropical Hong Kong, to examine the progress of recovery of macrobenthic community, based on analyses of both life-history traits and trophic guilds of polychaetes, upon cessation of organic pollution caused by sewage discharge. Seventy seven out of 83 species collected were classified under four ecological groups based on the life-history traits and sensitivity to organic gradients. The mean ATZI marine biotic index (AMBI) derived from these ecological groups showed spatial difference among the five sampling locations. In particular, the presence of different percentages of polychaete species from Groups III (unbalanced community) and IV (polluted community) suggested the presence of pollution stress in certain degree at all sampling locations. However, no significant temporal changes were noted over the study period. From all polychaete species identified, they were classified into 13 feeding guilds. The mean diversity of these feeding guilds at most of the sampling locations was significantly higher than that at one of the inside-harbour locations. The composition of feeding guilds was also significantly different spatially. At one of the inside-harbour locations, the dominant feeding guilds were motile/discretely motile surface deposit feeders with tentaculates or unarmed pharynx, and motile omnivores with jawed pharynx in the first year of study, but were replaced by motile, jawed carnivores in the second year of study. The increased proportion of carnivores over the study period can be seen as a sign of recovery in the community structure since abundance of predators is commonly higher in habitats with better environmental quality. The implications of using life-history traits and feeding guild analyses for benthic community are discussed.

  1. Assessment of soft-bottom polychaete assemblages in the Gulf of Lions (NW Mediterranean) based on a mesoscale survey

    NASA Astrophysics Data System (ADS)

    Labrune, Céline; Grémare, Antoine; Amouroux, Jean-Michel; Sardá, Rafael; Gil, João; Taboada, Sergi

    2007-01-01

    Ninety-two stations (10, 20, 30, 40 and 50 m depth) located on 21 inshore-offshore transects between the French-Spanish border and the mouth of the Rhône River were sampled during the 1998 Fall. Their polychaete fauna was analyzed to: (1) describe the distribution pattern of polychaete assemblages at the scale of the whole Gulf of Lions, (2) identify the relationships between these assemblages and the main environmental parameters, (3) establish a link between these assemblages and the benthic communities already described for Northwestern Mediterranean, and (4) assess recent historical changes in trends in densities and α diversity between assemblages. Three polychaete assemblages were identified using cluster analysis and associated procedures. These assemblages were tightly associated with depth and sediment granulometry as indicated by the concordance between their spatial distributions and the sedimentary map of the Gulf of Lions. Assemblage I contained most of the 10 and 20 m deep stations and was associated with littoral fine sands. Assemblage I was found all over the Gulf of Lions and was characterized by high abundance and high biomass due to the presence of large numbers of the serpulid Ditrupa arietina. Assemblage II was mostly composed of 30 m deep stations and was associated with littoral sandy mud. Assemblage II was dominated by the lumbrinerid Lumbrineris latreilli. It was composed of two sub-assemblages (IIa and IIb) in relation with sediment granulometry. Sub-assemblage IIb was associated with finer sediment than sub-assemblage IIa. Sub-assemblage IIa was only found in the Southern part of the Gulf of Lions, whereas sub-assemblage IIb was mostly found in the Northern part of the Gulf of Lions. This pattern is probably indicative of the sedimentation of fine particles originating from the Rhône River at intermediate depth as suggested by: (1) the sedimentary map of the Gulf of Lions, and (2) the outputs of recent models of sediment transport in

  2. A new genus and family of copepods (Crustacea: Copepoda) parasitic on polychaetes of the genus Jasmineira Langerhans, 1880 (family Sabellidae) in the northeastern Atlantic.

    PubMed

    Boxshall, Geoff A; O'Reilly, Myles; Sikorski, Andrey; Summerfield, Rebecca

    2015-01-01

    A new genus and species of copepod, Jasmineiricola mackiei n. gen. et n. sp., parasitic on at least three species of the sabellid polychaete genus Jasmineira Langerhans, 1880 is described. The adult female is mesoparasitic, living with part of its body (the endosoma) embedded within the host and part (the ectosoma) protruding through the host's body wall. The endosoma consists of a well defined head region carried anteriorly on the trunk which has paired lateral lobes housing the ovaries. The head bears a rosette-like array of eight slender lobes, which are probably derived from the mouthparts. The only limbs present on the trunk are the subchelate maxillipeds positioned immediately posterior to the head. The ectosoma consists of a posterior genito-abdominal lobe bearing paired genital apertures. The male is unknown. The new genus cannot be placed in any of the five existing families of mesoparasitic copepods on polychaete hosts and is treated as the type of a new monotypic family, the Jasmineiricolidae. The new species occurs over a depth range from 19 to 279 m, and is widely distributed from UK coastal waters to Norwegian waters inside the Arctic Circle. PMID:26624049

  3. Hidden in the crowd: primordial germ cells and somatic stem cells in the mesodermal posterior growth zone of the polychaete Platynereis dumerillii are two distinct cell populations

    PubMed Central

    2012-01-01

    Background In the polychaete Platynereis, the primordial germ cells (PGCs) emerge from the vasa, piwi, and PL10 expressing mesodermal posterior growth zone (MPGZ) at the end of larval development, suggesting a post-embryonic formation from stem cells. Methods In order to verify this hypothesis, embryos and larvae were pulse labeled with the proliferation marker 5-ethynyl-2'-deoxyuridine (EdU) at different stages of development. Subsequently, the PGCs were visualized in 7-day-old young worms using antibodies against the Vasa protein. Results Surprisingly, the primordial germ cells of Platynereis incorporate EdU only shortly before gastrulation (6-8 hours post fertilization (hpf)), which coincides with the emergence of four small blastomeres from the mesoblast lineage. We conclude that these so-called 'secondary mesoblast cells' constitute the definitive PGCs in Platynereis. In contrast, the cells of the MPGZ incorporate EdU only from the pre-trochophore stage onward (14 hpf). Conclusion While PGCs and the cells of the MPGZ in Platynereis are indistinguishable in morphology and both express the germline markers vasa, nanos, and piwi, a distinct cluster of PGCs is detectable anterior of the MPGZ following EdU pulse-labeling. Indeed the PGCs form independently from the stem cells of the MPGZ prior to gastrulation. Our data suggest an early PGC formation in the polychaete by preformation rather than by epigenesis. PMID:22512981

  4. Gel-Based and Gel-Free Identification of Proteins and Phosphopeptides during Egg-to-Larva Transition in Polychaete Neanthes arenaceodentata

    PubMed Central

    Chandramouli, Kondethimmanahalli H.; Reish, Donald; Qian, Pei-Yuan

    2012-01-01

    The polychaete Neanthes arenaceodentata- is cosmopolitan in distribution-, has been used as a laboratory test animal. Life history of this species has several unique features; the female dies after spawning and the male incubates the fertilized eggs through the 21-segmented stage. The larvae leave the tube and commence feeding. Changes in protein abundance and phosphorylation were examined during early development of N. arenaceodentata. A gel-based approach and gel-free enrichment of phosphopeptides coupled with mass spectrometry were used to identify proteins and phosphopeptides in fertilized ova and larval stages. Patterns of proteins and phosphoproteins changed from fertilized ova to larval stages. Twelve proteins occurred in phosphorylated form and nine as stage specific proteins. Cytoskeletal proteins have exhibited differential phosphorylation from ova to larval stages; whereas, other proteins exhibited stage-specific phosphorylation patterns. Ten phosphopeptides were identified that showed phosphorylation sites on serine or threonine residues. Sixty percent of the identified proteins were related to structural reorganization and others with protein synthesis, stress response and attachment. The abundance and distribution of two cytoskeleton proteins were examined further by 2-DE Western blot analysis. This is the first report on changes in protein expression and phosphorylation sites at Thr/Ser in early development of N. arenaceodentata. The 2-DE proteome maps and identified phosphoproteins contributes toward understanding the state of fertilized ova and early larval stages and serves as a basis for further studies on proteomics changes under different developmental conditions in this and other polychaete species. PMID:22719953

  5. The effect of sewage pollution on the feeding behaviour and diet of Hediste (Nereis diversicolor (O.F. Müller, 1776)) in three estuaries in south-east England, with implications for saltmarsh erosion.

    PubMed

    Aberson, M J R; Bolam, S G; Hughes, R G

    2016-04-15

    Stable isotope analyses of the abundant infaunal polychaete Hediste diversicolor, recognised as an indicator of sewage pollution, support the hypothesis that nutrient enrichment promotes surface deposit feeding, over suspension feeding and predation. At sewage-polluted sites in three estuaries in SE England Hediste mainly consumed microphytobenthos, sediment organic matter and filamentous macroalgae Ulva spp. At cleaner sites Hediste relied more on suspension feeding and consumption of Spartina anglica. There were no consistent differences in Hediste densities between the polluted and cleaner sites, probably because of increased densities at the cleaner sites too, facilitated by the planting of Spartina and nitrogen enrichment there too, including from agricultural run-off. Increased nutrient enrichment and the artificial availability of Spartina have probably increased densities of, and deposit-feeding by, Hediste in the past half-century and contributed indirectly to saltmarsh losses, since deposit-feeding by Hediste has been implicated in recent saltmarsh erosion in SE England.

  6. Ecological release and niche partitioning under stress: Lessons from dorvilleid polychaetes in sulfidic sediments at methane seeps

    NASA Astrophysics Data System (ADS)

    Levin, Lisa A.; Ziebis, Wiebke; Mendoza, Guillermo F.; Bertics, Victoria J.; Washington, Tracy; Gonzalez, Jennifer; Thurber, Andrew R.; Ebbe, Brigitte; Lee, Raymond W.

    2013-08-01

    assemblages (measured by Total Hull Area and Standard Elliptical Area using species averages) and functional redundancy or species packing (measured as distance to nearest neighbor) among species and individuals were generally higher at ER, where sulfide levels were lower than at HR. In contrast, average trophic diversity among individuals within a species was greater at HR than ER. In colonization experiments involving agar-based manipulations of sulfide in tray sediments that mimicked clam bed and mat conditions, dorvilleids comprised 68% and 48% of colonists at ER and HR, respectively. Dorvilleid species richness was higher in trays that were initially more sulfidic. However, habitat exerted stronger influence on the composition of colonizing dorvilleids than did sulfide additions. In the NE Pacific, regional, habitat and vertical (down-core) variation in hydrogen sulfide creates complex environmental heterogeneity at methane seeps, promoting high diversity of stress-tolerant taxa such as dorvilleid polychaetes.

  7. Polychaete/amphipod ratio as an indicator of environmental impact related to offshore oil and gas production along the Norwegian continental shelf.

    PubMed

    Andrade, Hector; Renaud, Paul E

    2011-12-01

    Benthic faunal data is regularly collected worldwide to assess the ecological quality of marine environments. Recently, there has been renewed interest in developing biological indices able to identify environmental status and potential anthropogenic impacts. In this paper we evaluate the performance of a general polychaete/amphipod ratio along the Norwegian continental shelf as an environmental indicator for offshore oil and gas impacts. Two main trends are apparent: first, a contamination gradient is discernible from where production takes place compared to stations 10,000 m away. Second, the quality of the marine environment has improved over time. These results are consistent with monitoring reports employing a combination of uni- and multi-variate statistics. Thus, we consider this ratio as a relatively simple, useful and potentially cost-effective complement to other more demanding assessment techniques. Because of its strong theoretical basis, it may also be useful for detecting ecological change as a result of other activities. PMID:22000480

  8. Can UV radiation affect benthic deposit-feeders through biochemical alteration of food resources? An experimental study with juveniles of the benthic polychaete Eupolymnia nebulosa.

    PubMed

    Nahon, Sarah; Pruski, Audrey M; Duchêne, Jean-Claude; Méjanelle, Laurence; Vétion, Gilles; Desmalades, Martin; Charles, François

    2011-05-01

    The growth, tentacle development and feeding activity of the benthic polychaete Eupolymnia nebulosa were examined to determine whether UV might affect marine deposit-feeders indirectly through the modification of the nutritional quality of their resources. Since marine invertebrates have higher nutritional requirements during the period following settlement, we tested the effect of UV-altered phytodetritus on freshly settled juveniles of E. nebulosa. Phytodetritus was prepared from cultures of the diatom Skeletonema costatum either grown under or sheltered from UVB radiation. Sterol content of phytodetritus was unmodified by UV radiation. Conversely, phytodetritus was noticeably depleted in polyunsaturated fatty acids. Growth and tentacle development of juveniles fed on altered phytodetritus were reduced by 35% and 15% respectively, suggesting potential deficiencies in essential nutrients. In response to the lower quality of the phytodetritus, juveniles explored a wider area as they search for food, a strategy that could compensate for low food quality. PMID:21388674

  9. Digestive efficiencies of Cape white-eyes (Zosterops virens), red-winged starlings (Onychognathus morio) and speckled mousebirds (Colius striatus) fed varying concentrations of equicaloric glucose or sucrose artificial fruit diets.

    PubMed

    Zungu, Manqoba M; Downs, Colleen T

    2016-09-01

    Digestive physiology is important for understanding the feeding behaviour of organisms. Specifically, studies on the digestive physiology of frugivorous and nectarivorous birds are important for elucidating their preference patterns in the wild and the selective pressures they exert on fruit pulp and nectar. In this study, digesta transit times and digestive efficiencies of three species of birds, the Cape white-eyes (Zosterops virens), red-winged starlings (Onychognathus morio) and speckled mousebirds (Colius striatus) were investigated on equicaloric glucose or sucrose artificial fruit diets. Three concentrations, approximating the natural range of sugar concentrations in sugary, bird-dispersed fruits were used: low (6.6%), medium (12.4%) and high (22%). Digesta transit times of birds increased with an increase in concentration for all diets but were generally higher on glucose diets. Intake rates, on the other hand, decreased with an increase in sugar concentration. All species of birds failed to maintain a constant assimilated energy intake on glucose diets but mousebirds and white-eyes maintained it on sucrose diets. Apparent assimilation efficiencies of glucose diets for all species were comparable and typical of those found in other frugivorous birds. However, assimilation efficiencies for sucrose diets differed widely with red-winged starlings displaying very low assimilation efficiencies and as a consequence; they lost significant body mass on all sucrose diets. These results demonstrate the importance of digestive physiology in explaining fruit selection patterns in frugivorous birds and how a seemingly trivial physiological trait can have dire ecological consequences. PMID:27174647

  10. Evolution of clitellate phaosomes from rhabdomeric photoreceptor cells of polychaetes – a study in the leech Helobdella robusta (Annelida, Sedentaria, Clitellata)

    PubMed Central

    2013-01-01

    Introduction In Annelida two types of photoreceptor cells (PRCs) are regarded as generally present, rhabdomeric and ciliary PRCs. In certain taxa, however, an additional type of PRC may occur, the so called phaosomal PRC. Whereas the former two types of PRCs are always organized as an epithelium with their sensory processes projecting into an extracellular cavity formed by the PRCs and (pigmented) supportive cells, phaosomes are seemingly intracellular vacuoles housing the sensory processes. Phaosomal PRCs are the only type of PRC found in one major annelid group, Clitellata. Several hypotheses have been put forward explaining the evolutionary origin of the clitellate phaosomes. To elucidate the evolution of clitellate PRC and eyes the leech Helobdella robusta, for which a sequenced genome is available, was chosen. Results TEM observations showed that extraocular and ocular PRCs are structurally identical. Bioinformatic analyses revealed predictions for four opsin genes, three of which could be amplified. All belong to the rhabdomeric opsin family and phylogenetic analyses showed them in a derived position within annelid opsins. Gene expression studies showed two of them expressed in the eye and in the extraocular PRCs. Polychaete eye-typic key enzymes for ommochromme and pterin shading pigments synthesis are not expressed in leech eyes. Conclusions By comparative gene-expression studies we herein provide strong evidence that the phaosomal PRCs typical of Clitellata are derived from the rhabdomeric PRCs characteristic for polychaete adult eyes. Thus, they represent a highly derived type of PRC that evolved in the stem lineage of Clitellata rather than another, primitive type of PRC in Metazoa. Evolution of these PRCs in Clitellata is related to a loss of the primary eyes and most of their photoreceptive elements except for the rhabdomeric PRCs. Most likely this happened while changing to an endobenthic mode of life. This hypothesis of PRC evolution is in accordance

  11. Experimental infection of Hawai'i 'Amakihi (hemignathus virens) with West Nile virus and competence of a co-occurring vector, culex quinquefasciatus: potential impacts on endemic Hawaiian avifauna.

    USGS Publications Warehouse

    Lapointe, D.A.; Hofmeister, E.K.; Atkinson, C.T.; Porter, R.E.; Dusek, R.J.

    2009-01-01

    Introduced mosquito-borne avian disease is a major limiting factor in the recovery and restoration of native Hawaiian forest birds. Annual epizootics of avian pox (Avipoxvirus) and avian malaria (Plasmodium relictum) likely led to the extinction of some species and continue to impact populations of susceptible Hawaiian honeycreepers (Drepanidinae). The introduction of a novel pathogen, such as West Nile virus (WNV), could result in further population declines and extinctions. During September and October 2004, we infected Hawai'i' Amakihi (Hemignathus virens) with a North American isolate of WNV by needle inoculation and mosquito bite to observe susceptibility, mortality, and illness in this endemic passerine, and to determine the vector competence of the co-occurring, introduced mosquito Culex quinquefasciatus. All experimentally infected Hawai'i ;Amakihi became viremic, with a mean titer >10(5) plaque-forming units (PFU)/ml, and they experienced clinical signs ranging from anorexia and lethargy to ataxia. The fatality rate among needle-inoculated Hawai'i' Amakihi (n=16) was 31.3%, but mortality in free-ranging birds is likely to increase due to predation, starvation, thermal stress, and concomitant infections of avian malaria and pox. Surviving Hawai'i' Amakihi seem to clear WNV from the peripheral blood by 7-10 days postinfection (DPI), and neutralizing antibodies were detected from 9 to 46 DPI. In transmission trials, Hawaiian Cx. quinquefasciatus proved to be a competent vector and Hawai'i Amakihi an adequate amplification host of WNV, suggesting that epizootic WNV could readily become an additional limiting factor of some native Hawaiian bird populations.

  12. Effects of the antidepressant fluoxetine in spiked-sediments on developmental and reproductive features of the polychaetes Capitella teleta and Capitella sp A.

    PubMed

    Méndez, Nuria; Barata, Carlos

    2015-01-01

    The cosmopolitan species-complex Capitella, a deposit-feeding polychaete, is widely used as an indicator of organic pollution and plays an important role in sewage waste cycling in marine and estuarine ecosystems. The antidepressant fluoxetine can be accumulated in sewage effluents and it could pose a hazard to infauna inhabiting surrounding areas. The study aimed to assess effects of fluoxetine on juveniles and adults of Capitella teleta and Capitella sp A. Sediments were spiked with four fluoxetine concentrations (0.001, 0.03, 0.3 and 3.3 µg/g dry wt. sediment). Chronically exposed worms of C. teleta showed delay of maturity, delay or inhibition of copulation and morphological abnormalities (genital spines in males and juveniles) with adverse physiological consequences. Alternatively, in C. teleta fluoxetine enhanced proteroginous individuals that may be beneficial for the population. Worms of Capitella sp A only showed delay or inhibition of copulation. Observed fluoxetine adverse effects could have important ecological implications in natural populations of aquatic invertebrates due to the possible alteration or even inhibition of reproductive processes. PMID:25359692

  13. Susceptibility to heavy metals and characterization of heterotrophic bacteria isolated from two hydrothermal vent polychaete annelids, Alvinella pompejana and Alvinella caudata

    SciTech Connect

    Jeanthon, C.; Prieur, D. )

    1990-11-01

    Specimens of alvinellid polychaetes and their tubes were collected in the Parigo hydrothermal vent field on the East Pacific Rise (13{degree}N) in October and November 1987. Heterotrophic bacterial strains were isolated on metal-amended media from the tube and dorsal integument of one specimen of Alvinella pompejana, from the dorsal integument of another from the whole integument of a specimen of Alvinella caudata, and from undetermined alvinellid tubes. The strains were characterized and tested for susceptibility to five heavy metals by using a microdilution method for MIC determinations. All strains were gram-negative rods. Most of them were characterized by the ability to degrade Tween 80 and gelatin and to produce hydrogen sulfide from cysteine. Numerous strains, from all sample origins, displayed resistance to cadmium, zinc, arsenate, and silver and tolerated high amounts of copper. Metal resistance was exhibited by 92.3% of the total isolates. The occurrence of multiply resistant bacteria may demonstrate an adaptation of alvinellid-associated microflora to the general enrichment of metals in the hydrothermal vent environment.

  14. The role of the invasive polychaete Ficopomatus enigmaticus (Fauvel, 1923) (Serpulidae) as facilitator of parasite transmission in Mar Chiquita coastal lagoon (Buenos Aires, Argentina).

    PubMed

    Etchegoin, J A; Merlo, M J; Parietti, M

    2012-09-01

    In Mar Chiquita coastal lagoon (Argentina), the reefs of the invasive polychaete Ficopomatus enigmaticus (Serpulidae) serve as concentration areas for invertebrates and vertebrates and as potential foci of parasite transmission (mainly digeneans). To analyse the role of F. enigmaticus as facilitator of parasite transmission, and to evaluate the influence of the habitats selected by 2 species of cochliopid snails (Heleobia conexa and Heleobia australis), on the richness and on the prevalence of the digenean assemblages that parasitize them, 1945 snails were collected from 2 sampling sites. The comparisons between larval digenean communities parasitizing both snail hosts revealed significant differences related to the overall prevalence and the prevalence contributed by birds in the snails collected from reefs. These results support the idea that the reefs may increase the number of links between intermediate and definitive hosts of digeneans, facilitating parasite transmission only when the aggregates of F. enigmaticus become the unique habitat of the snail host. This first report of an exotic species acting as facilitator of parasite transmission in an estuarine area highlights the importance of analysing the effects of the assimilation process of exotic species by recently colonized environments (including the possible effects on parasite transmission).

  15. Pigmented eyes, photoreceptor-like sense organs and central nervous system in the polychaete Scoloplos armiger (Orbiniidae, Annelida) and their phylogenetic importance.

    PubMed

    Wilkens, Verena; Purschke, Günter

    2009-11-01

    The phylogenetic position of Orbiniidae within Annelida is unresolved. Conflicting hypotheses place them either in a basal taxon Scolecida, close to Spionida, or in a basal position in Aciculata. Because Aciculata have a specific type of eye, the photoreceptive organs in the orbiniid Scoloplos armiger were investigated to test these phylogenetic hypotheses. Two different types of prostomial photoreceptor-like sense organs were found in juveniles and one additional in subadults. In juveniles there are four ciliary photoreceptor-like phaosomes with unbranched cilia and two pigmented eyes. The paired pigmented eyes lie beside the brain above the circumoesophageal connectives. Each consists of one pigmented cell, one unpigmented supportive cell and three everse rhabdomeric sensory cells with vestigial cilia. During development the number of phaosomes increases considerably and numerous unpigmented sense organs appear consisting of one rhabdomeric photoreceptor cell and one supportive cell. The development and morphology of the pigmented eyes of S. armiger suggest that they represent miniaturized eyes of the phyllodocidan type of adult eye rather than persisting larval eyes resulting in small inverse eyes typical of Scolecida. Moreover, the structure of the brain indicates a loss of the palps. Hence, a closer relationship of Orbiniidae to Phyllodocida is indicated. Due to a still extensive lack of ultrastructural data among polychaetes this conclusion cannot be corroborated by considering the structure of the unpigmented ciliary and rhabdomeric photoreceptor-like sense organs.

  16. Adaptation and acclimatization to ocean acidification in marine ectotherms: an in situ transplant experiment with polychaetes at a shallow CO2 vent system.

    PubMed

    Calosi, Piero; Rastrick, Samuel P S; Lombardi, Chiara; de Guzman, Heidi J; Davidson, Laura; Jahnke, Marlene; Giangrande, Adriana; Hardege, Jörg D; Schulze, Anja; Spicer, John I; Gambi, Maria-Cristina

    2013-01-01

    Metabolic rate determines the physiological and life-history performances of ectotherms. Thus, the extent to which such rates are sensitive and plastic to environmental perturbation is central to an organism's ability to function in a changing environment. Little is known of long-term metabolic plasticity and potential for metabolic adaptation in marine ectotherms exposed to elevated pCO2. Consequently, we carried out a series of in situ transplant experiments using a number of tolerant and sensitive polychaete species living around a natural CO2 vent system. Here, we show that a marine metazoan (i.e. Platynereis dumerilii) was able to adapt to chronic and elevated levels of pCO2. The vent population of P. dumerilii was physiologically and genetically different from nearby populations that experience low pCO2, as well as smaller in body size. By contrast, different populations of Amphiglena mediterranea showed marked physiological plasticity indicating that adaptation or acclimatization are both viable strategies for the successful colonization of elevated pCO2 environments. In addition, sensitive species showed either a reduced or increased metabolism when exposed acutely to elevated pCO2. Our findings may help explain, from a metabolic perspective, the occurrence of past mass extinction, as well as shed light on alternative pathways of resilience in species facing ongoing ocean acidification.

  17. Exploring the limit of metazoan thermal tolerance via comparative proteomics: thermally induced changes in protein abundance by two hydrothermal vent polychaetes

    PubMed Central

    Dilly, Geoffrey F.; Young, C. Robert; Lane, William S.; Pangilinan, Jasmyn; Girguis, Peter R.

    2012-01-01

    Temperatures around hydrothermal vents are highly variable, ranging from near freezing up to 300°C. Nevertheless, animals thrive around vents, some of which live near the known limits of animal thermotolerance. Paralvinella sulfincola, an extremely thermotolerant vent polychaete, and Paralvinella palmiformis, a cooler-adapted congener, are found along the Juan de Fuca Ridge in the northwestern Pacific. We conducted shipboard high-pressure thermotolerance experiments on both species to characterize the physiological adaptations underlying P. sulfincola's pronounced thermotolerance. Quantitative proteomics, expressed sequence tag (EST) libraries and glutathione assays revealed that P. sulfincola (i) exhibited an upregulation in the synthesis and recycling of glutathione with increasing temperature, (ii) downregulated nicotinamide adenine dinucleotide (NADH) and succinate dehydrogenases (key enzymes in oxidative phosphorylation) with increasing temperature, and (iii) maintained elevated levels of heat shock proteins (HSPs) across all treatments. In contrast, P. palmiformis exhibited more typical responses to increasing temperatures (e.g. increasing HSPs at higher temperatures). These data reveal differences in how a mesotolerant and extremely thermotolerant eukaryote respond to thermal stress, and suggest that P. sulfincola's capacity to mitigate oxidative stress via increased synthesis of antioxidants and decreased flux through the mitochondrial electron transport chain enable pronounced thermotolerance. Ultimately, oxidative stress may be the key factor in limiting all metazoan thermotolerance. PMID:22553092

  18. Adaptation and acclimatization to ocean acidification in marine ectotherms: an in situ transplant experiment with polychaetes at a shallow CO2 vent system

    PubMed Central

    Calosi, Piero; Rastrick, Samuel P. S.; Lombardi, Chiara; de Guzman, Heidi J.; Davidson, Laura; Jahnke, Marlene; Giangrande, Adriana; Hardege, Jörg D.; Schulze, Anja; Spicer, John I.; Gambi, Maria-Cristina

    2013-01-01

    Metabolic rate determines the physiological and life-history performances of ectotherms. Thus, the extent to which such rates are sensitive and plastic to environmental perturbation is central to an organism's ability to function in a changing environment. Little is known of long-term metabolic plasticity and potential for metabolic adaptation in marine ectotherms exposed to elevated pCO2. Consequently, we carried out a series of in situ transplant experiments using a number of tolerant and sensitive polychaete species living around a natural CO2 vent system. Here, we show that a marine metazoan (i.e. Platynereis dumerilii) was able to adapt to chronic and elevated levels of pCO2. The vent population of P. dumerilii was physiologically and genetically different from nearby populations that experience low pCO2, as well as smaller in body size. By contrast, different populations of Amphiglena mediterranea showed marked physiological plasticity indicating that adaptation or acclimatization are both viable strategies for the successful colonization of elevated pCO2 environments. In addition, sensitive species showed either a reduced or increased metabolism when exposed acutely to elevated pCO2. Our findings may help explain, from a metabolic perspective, the occurrence of past mass extinction, as well as shed light on alternative pathways of resilience in species facing ongoing ocean acidification. PMID:23980245

  19. Population structure and spread of the polychaete Diopatra biscayensis along the French Atlantic coast: human-assisted transport by-passes larval dispersal.

    PubMed

    Woodin, Sarah Ann; Wethey, David S; Dubois, Stanislas F

    2014-12-01

    Intertidal populations of the ecosystem engineering polychaete, Diopatra biscayensis, were analyzed on the French Atlantic coast for three years with individual size estimated from tube-cap aperture. All but the northernmost population along the Bay of Biscay have yearly recruitment. Individuals live 3-5 years and are likely reproductive as one year olds. Simulations indicate dispersal distances are <50 km; yet, populations also exist within the Normano-Breton Gulf in the western English Channel, more than 450 km from the northernmost Bay of Biscay population at La Trinité-sur-Mer. Three of the four populations in the Normano-Breton Gulf have no young of the year, but are near to active mussel culture where mussel seed is transported on ropes from dense D. biscayensis areas in the Vendée-Charente region in the Bay of Biscay. The majority of D. biscayensis were adjacent to the likely source, mussel seed ropes. Transport assisted by aquaculture is the likely explanation for the populations in the Normano-Breton Gulf.

  20. Tissue distribution and histopathological effects of dietary methylmercury in benthic grubby Myoxocephalus aenaeus

    SciTech Connect

    Pelletier, E.; Audet, C.

    1995-05-01

    There is a need to test deterministic models predicting the behavior and effects of chemicals on aquatic systems by conducting experiments with more than one trophic step at a time. This approach requires the set-up of an experimental food chain in pounds or mesocosm facilities which can be used for dietary uptake studies and assessment of sublethal stress induced by contaminated food. In the course of our current research program at the INRS marine mesocosms facilities, a model benthic food chain including inter- and sub-tidal species such as the mussel (Mytilus edulis), clam (Mya arenaria), starfish (Leptasterias polaris), polychaete (Nereis virens), amphipod (Gammarus sp.), gastropod (Buccinum undatum), and fishes (Pleuronectec americanus, Myoxocephalus aenaeus), is used for testing food uptake models and for the development of sublethal toxicity tests which could be used in the environmental assessment of coastal and estuarine waters. Among these test organisms, the grubby (M. aenaeus) is a small coastal fish (12-15 cm) characterized by a broad head. The grubby is tolerant of water temperature and salinity variations and lives on a wide variety of bottom strata at low depths. The grubby is carnivorous and consumes a wide variety of molluscs and the young of many species of fish. Because of its size, its estuarine and coastal distribution and its large spectrum of prey, this species was seen as an ideal fish to fit into our experimental food chain model. This paper reports a preliminary experiment designed to measure distribution of mercury in tissues and to test the response of various histopathological and biochemical stress indicators in grubby exposed to dietary contamination by methylmercury (MeHg) for a 20-day exposure period. MeHg was chosen because it is rapidly bioaccumulated by most living organisms and its toxicity has been studied for decades in numerous aquatic ecosystems. 17 refs., 2 tabs.

  1. Distributions of key exposure factors controlling the uptake of xenobiotic chemicals in an estuarine food web

    SciTech Connect

    Iannuzzi, T.J.; Harrington, N.W.; Shear, N.M.; Curry, C.L.; Carlson-Lynch, H.; Henning, M.H.; Su, S.H.; Rabbe, D.E.

    1996-11-01

    A critical evaluation of literature on the behavior, physiology, and ecology of common estuarine organisms was conducted in an attempt to develop probabilistic distributions for those variables that influence the uptake of xenobiotic chemicals from sediments, water, and food sources. The ranges, central tendencies, and distributions of several key parameter values were identified for dominant organisms from various trophic levels, including the polychaete Nereis virens, mummichog (Fundulus heteroclitus), blue crab (Callinectes sapidus), and striped bass (Morone saxatilis). The exposure factors of interest included ingestion rate for various food sources, growth rate, respiration rate, excretion rate, body weight, wet/dry weight ratio, lipid content, chemical assimilation efficiency, and food assimilation efficiency. These exposure factors are critical to the execution of mechanistic food web models, which, when properly calibrated, can be used to estimate tissue concentrations of nonionic chemicals in aquatic organisms based on knowledge of the bioenergetics and feeding interactions within a food web and the sediment and water concentrations of chemicals. In this article the authors describe the use of distributions for various exposure factors in the context of a mechanistic bioaccumulation model that is amenable to probabilistic analyses for multiple organisms within a food web. A case study is provided which compares the estimated versus measured concentrations of five polychlorinated biphenyl (PCB) congeners in a representative food web from the tidal portion of the Passaic River, New Jersey, USA. The results suggest that the model is accurate within an order of magnitude or less in estimating the bioaccumulation of PCBs in this food web without calibration. The results of a model sensitivity analysis suggest that the input parameters which most influence the output of the model are both chemical and organism specific.

  2. Ecological evaluation of proposed dredged material from Richmond Harbor Deepening Project and the intensive study of the Turning Basin

    SciTech Connect

    Pinza, M.R.; Mayhew, H.L.; Karle, L.M.; Kohn, N.P.; White, P.J.; Word, J.Q.; Michaels, L.L.

    1995-06-01

    Richmond Harbor is on the eastern shoreline of central San Francisco Bay and its access channels and several of the shipping berths are no longer wide or deep enough to accommodate modem deeper-draft vessels. The Water Resources Development Act of 1986 (PL99-662) authorized the US Army Corps of Engineers (USACE), San Francisco District to deepen and widen the navigation channels in Richmond Harbor. Several options for disposal of the material from this dredging project are under consideration by USACE: disposal within San Francisco Bay, at open-ocean disposal sites, or at uplands disposal sites. Purpose of this study was to conduct comprehensive evaluations, including chemical, biological, and bioaccumulation testing of sediments in selected areas of Richmond Harbor. This information was required by the Environmental Protection Agency (EPA) and USACE. Battelle/Marine Sciences Laboratory collected 20 core samples, both 4-in. and 12-in., to a project depth of -40 ft mean lower low water (MLLW) (-38 ft MLLW plus 2 ft of overdepth) using a vibratory-hammer core. These 20 field samples were combined to form five test composites plus an older bay mud (OBM) composite that were analyzed for physical/chemical parameters, biological toxicity, and tissue chemistry. Solid-phase tests were conducted with the amphipod, Rhepoxynius abronius; the clam, Macoma nasuta; and the polychaete worm, Nephtys caecoides. Suspended-particulate-phase (SPP) tests were conducted with the sanddab, Citharichthys stigmaeus; the mysid, Holmesimysis costata; and the bivalve, Mytilus galloprovincialis. Bioaccumulation of contaminants was measured in tissues of Macoma nasuta and Nereis virens. Sediments from one ocean reference sediment, and two in-bay reference sediments, were tested concurrently. Results from analysis of the five test treatments were statistically compared with the reference sediment R-OS in the first five sections of this report.

  3. Understanding the life of a sandy beach polychaete of functional importance - Scolelepis squamata (Polychaeta: Spionidae) on Belgian sandy beaches (northeastern Atlantic, North Sea)

    NASA Astrophysics Data System (ADS)

    Speybroeck, Jeroen; Alsteens, Lotte; Vincx, Magda; Degraer, Steven

    2007-08-01

    The cosmopolitan sandy beach polychaete Scolelepis squamata constitutes an important food resource for juvenile flatfish and wading birds in the northeastern Atlantic, thus playing an important role in sandy beach ecosystem functioning. However, its population dynamics and life history in this part of the world have gone widely uninvestigated. Eight beach transects on Belgian sandy beaches were sampled monthly from October 2003 until October 2004, in order to investigate seasonal trends in the species' abundance, biomass, secondary production, and patterns in reproduction and zonation. Average density, modal density and modal biomass (ash-free dry weight) (mean average density = 169 ± 9 SE ind/m 2; mean modal density = 505 ± 38 SE ind/m 2; mean modal biomass = 0.25 ± 0.02 SE g/m 2) did not exhibit major seasonal changes, whereas average biomass (0.081 ± 0.005 SE g/m 2) and individuals and biomass per strip transect (IST = 16286 ± 1330 SE ind/m; BMST = 7.8 + 0.7 SE g/m) did, peaking in May 2004. Production was calculated at 1.9 g/(m 2*year) (size-frequency method, SFM) and 0.88 g/(m 2*year) (mass specific growth rate method, MSGR) and mean annual biomass was 0.797 g/m 2; resulting in a P/B ratio of 2.40/year (SFM) and 1.11/year (MSGR), which is intermediate to moderately low compared to other polychaete species. Gravid individuals were found from February until August and a single recruitment period was observed from July until September. An average sex ratio of 1.41 ± 0.08 SE was calculated, with a female predominance. Highest densities (>200 ind/m 2) were mostly found above 3 m above MLLWS and at a median grain size from 190 to 320 μm. Average modal or peak density along each transect was situated from 3.95 m up to 4.40 m above MLLWS, in contrast to some other studies where the species was restricted to mid-tidal levels. Significant differences in elevation of peak density were found between non-gravid (411 ± 4 SE cm) and gravid (402 ± 5 SE cm) animals

  4. The spatial and temporal expression of Ch-en, the engrailed gene in the polychaete Chaetopterus, does not support a role in body axis segmentation

    NASA Technical Reports Server (NTRS)

    Seaver, E. C.; Paulson, D. A.; Irvine, S. Q.; Martindale, M. Q.

    2001-01-01

    We are interested in understanding whether the annelids and arthropods shared a common segmented ancestor and have approached this question by characterizing the expression pattern of the segment polarity gene engrailed (en) in a basal annelid, the polychaete Chaetopterus. We have isolated an en gene, Ch-en, from a Chaetopterus cDNA library. Genomic Southern blotting suggests that this is the only en class gene in this animal. The predicted protein sequence of the 1.2-kb cDNA clone contains all five domains characteristic of en proteins in other taxa, including the en class homeobox. Whole-mount in situ hybridization reveals that Ch-en is expressed throughout larval life in a complex spatial and temporal pattern. The Ch-en transcript is initially detected in a small number of neurons associated with the apical organ and in the posterior portion of the prototrochophore. At later stages, Ch-en is expressed in distinct patterns in the three segmented body regions (A, B, and C) of Chaetopterus. In all segments, Ch-en is expressed in a small set of segmentally iterated cells in the CNS. In the A region, Ch-en is also expressed in a small group of mesodermal cells at the base of the chaetal sacs. In the B region, Ch-en is initially expressed broadly in the mesoderm that then resolves into one band/segment coincident with morphological segmentation. The mesodermal expression in the B region is located in the anterior region of each segment, as defined by the position of ganglia in the ventral nerve cord, and is involved in the morphogenesis of segment-specific feeding structures late in larval life. We observe banded mesodermal and ectodermal staining in an anterior-posterior sequence in the C region. We do not observe a segment polarity pattern of expression of Ch-en in the ectoderm, as is observed in arthropods. Copyright 2001 Academic Press.

  5. Assessment of mercury bioavailability to benthic macroinvertebrates using diffusive gradients in thin films (DGT).

    PubMed

    Amirbahman, Aria; Massey, Delia I; Lotufo, Guilherme; Steenhaut, Nicholas; Brown, Lauren E; Biedenbach, James M; Magar, Victor S

    2013-10-01

    Mercury-specific diffusive gradient in thin films (DGTs) were used in laboratory microcosms as a biomonitoring tool to assess the lability of mercury (Hg) total and monomethylmercury Hg (MeHg), and to develop a relationship between chemical lability and bioavailability in estuarine sediments. Time-series deployment of DGTs in sediments showed that sediment-bound MeHg is more labile than sediment-bound inorganic Hg. In subsequent experiments, DGTs were deployed simultaneously with three benthic macroinvertebrates (the estuarine amphipod, Leptocheirus plumulosus; the estuarine polychaete, Nereis virens; and the marine clam, Macoma nasuta) in sediments for up to 55 days. All organisms and their co-deployed DGTs exhibited an initial period of rapid Hg uptake followed by slower uptake reaching apparent steady state. Strong correlative relationships were generally observed between paddle-type DGTs and macroinvertebrate tissue data (r(2) between 0.57 and 0.97). Further, %MeHg:Total Hg ratios for M. nasuta and N. virens (38.5 ± 12.2 and 19.2 ± 5.2) were similar to their corresponding ratios for the DGTs (33.1 ± 13.3 and 24.4 ± 11.0), and they were significantly higher than the same ratios for sediment (2.9 ± 0.3) and pore water (8.5 ± 4.9). The %MeHg:Total Hg ratios for L. plumulosus (68.5 ± 6.2) were significantly higher than those for the DGTs. This may be because the tissue and DGT data for this organism were not truly co-located as L. plumulosus burrows close to the sediment surface, and the DGTs sampled the sediment surface. Overall, our results suggest that for benthic macroinvertebrates in estuarine sediments studied here, (a) sediment MeHg is more bioavailable than inorganic Hg, (b) sediment and pore-water concentration measurements are not good predictors for the extent of bioaccumulation of Hg species, and (c) DGTs are an effective biomonitoring tool for the assessment of bioavailability of Hg species.

  6. Determining gene flow and the influence of selection across the equatorial barrier of the East Pacific Rise in the tube-dwelling polychaete Alvinella pompejana

    PubMed Central

    2010-01-01

    Background Comparative phylogeography recently performed on the mitochondrial cytochrome oxidase I (mtCOI) gene from seven deep-sea vent species suggested that the East Pacific Rise fauna has undergone a vicariant event with the emergence of a north/south physical barrier at the Equator 1-2 Mya. Within this specialised fauna, the tube-dwelling polychaete Alvinella pompejana showed reciprocal monophyly at mtCOI on each side of the Equator (9°50'N/7°25'S), suggesting potential, ongoing allopatric speciation. However, the development of a barrier to gene flow is a long and complex process. Secondary contact between previously isolated populations can occur when physical isolation has not persisted long enough to result in reproductive isolation between genetically divergent lineages, potentially leading to hybridisation and subsequent allelic introgression. The present study evaluates the strength of the equatorial barrier to gene flow and tests for potential secondary contact zones between A. pompejana populations by comparing the mtCOI gene with nuclear genes. Results Allozyme frequencies and the analysis of nucleotide polymorphisms at three nuclear loci confirmed the north/south genetic differentiation of Alvinella pompejana populations along the East Pacific Rise. Migration was oriented north-to-south with a moderate allelic introgression between the two geographic groups over a narrow geographic range just south of the barrier. Multilocus analysis also indicated that southern populations have undergone demographic expansion as previously suggested by a multispecies approach. A strong shift in allozyme frequencies together with a high level of divergence between alleles and a low number of 'hybrid' individuals were observed between the northern and southern groups using the phosphoglucomutase gene. In contrast, the S-adenosylhomocysteine hydrolase gene exhibited reduced diversity and a lack of population differentiation possibly due to a selective sweep or hitch

  7. Ephemeral bio-engineers or reef-building polychaetes: how stable are aggregations of the tube worm Lanice conchilega (Pallas, 1766)?

    PubMed

    Callaway, Ruth; Desroy, Nicolas; Dubois, Stanislas F; Fournier, Jérôme; Frost, Matthew; Godet, Laurent; Hendrick, Vicki J; Rabaut, Marijn

    2010-08-01

    Dense aggregations of tube-worms can stabilize sediments and generate oases for benthic communities that are different and often more diverse and abundant than those of the surroundings. If these features are to qualify as biogenic reefs under nature-conservation legislation such as the EC Habitats Directive, a level of stability and longevity is desirable aside from physical and biological attributes. Lanice conchilega (Pallas, 1766) is widely distributed around the European coast and aggregations of this tube-dwelling polychaete are known to have a positive effect on the biodiversity of associated species in inter- and sub-tidal areas. This increases the value of L. conchilega-rich habitats for higher trophic levels such as birds and fish. However, L. conchilega is currently not recognized as a reef builder primarily due to uncertainty about the stability of their aggregations. We carried out three studies on different spatial and temporal scales to explore a number of properties relating to stability: (1) Individual aggregations of L. conchilega of ∼1 m(2) were monitored for up to 1 year, (2) records of L. conchilega from a 258-ha area over a 35-year period were analyzed, (3) the recovery of a population of L. conchilega subjected to disturbances by cultivation of Manila clams (Ruditapes philippinarum) was followed over 3 years. The studies provided evidence about the longevity of L. conchilega aggregations, their resistance to disturbance, their resilience in recovering from negative impact and their large-scale persistence. The results showed that populations of L. conchilega were prone to considerable fluctuation and the stability of aggregations depended on environmental factors and on recruitment. The tube-worms proved to be susceptible to disturbance by cultivation of Manila clams but demonstrated the potential to recover from that impact. The long-term monitoring of a large L. conchilega population in the Bay of Mont Saint Michel (France) indicated that

  8. Three novel superoxide dismutase genes identified in the marine polychaete Perinereis nuntia and their differential responses to single and combined metal exposures.

    PubMed

    Won, Eun-Ji; Ra, Kongtae; Kim, Kyung-Tae; Lee, Jae-Seong; Lee, Young-Mi

    2014-09-01

    To identify superoxide dismutase (SOD) genes and evaluate their usefulness as potential markers for monitoring metal toxicity in aquatic environment, we cloned, sequenced, and characterized 3 SOD genes (Cu/Zn-SOD1, Cu/Zn-SOD2, and Mn-SOD) from the marine polychaete Perinereis nuntia. The accumulated metal contents and expressions of 3 SOD genes were compared after exposure to single and combinations of heavy metals, As, Ni, and Pb. The deduced amino acid sequences of the 3 SODs had evolutionary conserved domains, such as metal binding sites, and signature sequences. The phylogenetic analysis revealed that Cu/Zn-SOD1, Cu/Zn-SOD2, and Mn-SOD were clustered with extracellular Cu/Zn-SOD, intracellular Cu/Zn-SOD and mitochondrial Mn-SOD, respectively, of other species. The accumulated contents of Ni and Pb increased significantly in a time - dependent manner after exposure to both single and combination of the metals. However, the concentration of As did not change significantly in the exposure test. The quantitative real-time polymerase chain reaction (PCR) array showed that the 3 SOD genes had differential expression patterns depending on the exposure condition. The expression of all SODs mRNAs was significantly elevated in response to Pb alone and in combination with As. The mRNA level of Cu/Zn-SOD1 was the highest after exposure to Pb alone, while that of Mn-SOD was remarkably enhanced after exposure to a combination of As and Pb. Exposure to Ni alone rapidly elevated the expression of Cu/Zn-SOD1 and Mn-SOD mRNA, which then gradually decreased. Exposure to As had no significant effect on the modulation of any of the SOD genes of P. nuntia. These results suggest that all SOD genes might play important roles in cellular protection as antioxidant enzymes against heavy metal toxicity via different modes of action in P. nuntia and might have the potential to act as indicators in an environment containing a mixture of metals.

  9. The intertidal polychaete (Annelida) fauna of the Sitakunda coast (Chittagong, Bangladesh), with notes on the Capitellidae, Glyceridae, Lumbrineridae, Nephtyidae, Nereididae and Phyllodocidae of the “Northern Bay of Bengal Ecoregion”

    PubMed Central

    Muir, Alexander I.; Hossain, Md. M. Maruf

    2014-01-01

    Abstract Of seven species of polychaetous annelids collected from the intertidal zone of Sitakunda coast, Chittagong, Bangladesh, five were new records for the country. The seven are listed, with brief notes on these, some previously recorded! species and others housed in the collections of the Natural History Museum, London. Keys are given to the recorded species of Phyllodocidae, Nereididae, Lumbrineridae, Nephtyidae and Capitellidae of the “Northern Bay of Bengal Ecoregion”, and to the recognised species of Glyceridae from the Bay of Bengal. The worms in this Ecoregion are subject to the outflows of the Irrawaddy, Ganges, Hooghly and Mahanadi Rivers, and many of them are known to be freshwater tolerant. PMID:25061359

  10. Polychaete-parasitizing copepods from the deep-sea Kuril-Kamchatka Trench (Pacific Ocean), with the description of a new Ophelicola species and comments on the currently known annelidicolous copepods

    NASA Astrophysics Data System (ADS)

    Conradi, Mercedes; Bandera, M. Eugenia; Marin, Ivan; Martin, Daniel

    2015-01-01

    The annelid associated copepods, collectively called annelidicolous, were placed in 21 families. Some genera, such as Ophelicola, are considered phylogenetically isolated and are placed into the order Cyclopoida as incertae sedis. In this paper, we describe Ophelicola kurambia, the second species recorded for the genus and the first for the Pacific Ocean. The single known specimen, a female, was found during the German-Russian deep-sea expedition KuramBio at the deep-sea Kuril-Kamchatka Trench. The new species differs from Ophelicola drachi (known from the Gulf of Biscay, Atlantic Ocean) in being attached to the host through the mandibles instead of maxillae and, specially, in the formula of the antennular armature. The study of the new species contributes to clarify the diagnosis of the genus, which clearly differs from Notomasticola (another incertae sedis genus), and resembles both the most modified clausiids (in the mandibular shape and antennular segmentation) and the clausidiids (in the shape of maxilla). However, it does not contribute to clarify the position of Ophelicola within the order Cyclopoida. The paper includes a list of the known annelidicolous copepods (excluding Monstrilloidae) and summarises the main trends shown in terms of diversity, distribution and relationships. Currently, 168 species of copepods from to 74 genera and 22 families and 7 incertae sedis (excluding Monstrilloida) are known to be involved in 235 parasitic relationships (mostly ectoparasitic) with polychaetes. Host polychaetes include 156 species belonging to 104 genera from 22 families (plus 14 unknown). About 50% of these relationships are known from European waters, mainly from shallow depths.

  11. The B Vitamins Nicotinamide (B3) and Riboflavin (B2) Stimulate Metamorphosis in Larvae of the Deposit-Feeding Polychaete Capitella teleta: Implications for a Sensory Ligand-Gated Ion Channel

    PubMed Central

    Burns, Robert T.; Pechenik, Jan A.; Biggers, William J.; Scavo, Gia; Lehman, Christopher

    2014-01-01

    Marine sediments can contain B vitamins, presumably incorporated from settled, decaying phytoplankton and microorganisms associated with decomposition. Because B vitamins may be advantageous for the energetically intensive processes of metamorphosis, post-metamorphic growth, and reproduction, we tested several B vitamins to determine if they would stimulate larvae of the deposit-feeding polychaete Capitella teleta to settle and metamorphose. Nicotinamide and riboflavin individually stimulated larvae of C. teleta to settle and metamorphose, generally within 1–2 hours at nicotinamide concentrations as low as 3 µM and riboflavin concentrations as low as 50 µM. More than 80% of the larvae metamorphosed within 30 minutes at a nicotinamide concentration of 7 µM. The pyridine channel agonist pyrazinecarboxamide also stimulated metamorphosis at very low concentrations. In contrast, neither lumichrome, thiamine HCl, pyridoxine HCl, nor vitamin B12 stimulated larvae of C. teleta to metamorphose at concentrations as high as 500 µM. Larvae also did not metamorphose in response to either nicotinamide or pyrazinecarboxamide in calcium-free seawater or with the addition of 4-acetylpyridine, a competitive inhibitor of the pyridine receptor. Together, these results suggest that larvae of C. teleta are responding to nicotinamide and riboflavin via a chemosensory pyridine receptor similar to that previously reported to be present on crayfish chela and involved with food recognition. Our data are the first to implicate B vitamins as possible natural chemical settlement cues for marine invertebrate larvae. PMID:25390040

  12. Energy metabolism and cellular homeostasis trade-offs provide the basis for a new type of sensitivity to ocean acidification in a marine polychaete at a high-CO2 vent: adenylate and phosphagen energy pools versus carbonic anhydrase.

    PubMed

    Turner, Lucy M; Ricevuto, Elena; Massa-Gallucci, Alexia; Gambi, Maria-Cristina; Calosi, Piero

    2015-07-01

    Species distributions and ecology can often be explained by their physiological sensitivity to environmental conditions. Whilst we have a relatively good understanding of how these are shaped by temperature, for other emerging drivers, such as PCO2  we know relatively little. The marine polychaete Sabella spallanzanii increases its metabolic rate when exposed to high PCO2  conditions and remains absent from the CO2 vent of Ischia. To understand new possible pathways of sensitivity to CO2 in marine ectotherms, we examined the metabolic plasticity of S. spallanzanii exposed in situ to elevated PCO2  by measuring fundamental metabolite and carbonic anhydrase concentrations. We show that whilst this species can survive elevated PCO2  conditions in the short term, and exhibits an increase in energy metabolism, this is accompanied by a significant decrease in carbonic anhydrase concentration. These homeostatic changes are unlikely to be sustainable in the longer term, indicating S. spallanzanii may struggle with future high PCO2  conditions.

  13. Expression of the pair-rule gene homologs runt, Pax3/7, even-skipped-1 and even-skipped-2 during larval and juvenile development of the polychaete annelid Capitella teleta does not support a role in segmentation

    PubMed Central

    2012-01-01

    Background Annelids and arthropods each possess a segmented body. Whether this similarity represents an evolutionary convergence or inheritance from a common segmented ancestor is the subject of ongoing investigation. Methods To investigate whether annelids and arthropods share molecular components that control segmentation, we isolated orthologs of the Drosophila melanogaster pair-rule genes, runt, paired (Pax3/7) and eve, from the polychaete annelid Capitella teleta and used whole mount in situ hybridization to characterize their expression patterns. Results When segments first appear, expression of the single C. teleta runt ortholog is only detected in the brain. Later, Ct-runt is expressed in the ventral nerve cord, foregut and hindgut. Analysis of Pax genes in the C. teleta genome reveals the presence of a single Pax3/7 ortholog. Ct-Pax3/7 is initially detected in the mid-body prior to segmentation, but is restricted to two longitudinal bands in the ventral ectoderm. Each of the two C. teleta eve orthologs has a unique and complex expression pattern, although there is partial overlap in several tissues. Prior to and during segment formation, Ct-eve1 and Ct-eve2 are both expressed in the bilaterial pair of mesoteloblasts, while Ct-eve1 is expressed in the descendant mesodermal band cells. At later stages, Ct-eve2 is expressed in the central and peripheral nervous system, and in mesoderm along the dorsal midline. In late stage larvae and adults, Ct-eve1 and Ct-eve2 are expressed in the posterior growth zone. Conclusions C. teleta eve, Pax3/7 and runt homologs all have distinct expression patterns and share expression domains with homologs from other bilaterians. None of the pair-rule orthologs examined in C. teleta exhibit segmental or pair-rule stripes of expression in the ectoderm or mesoderm, consistent with an independent origin of segmentation between annelids and arthropods. PMID:22510249

  14. The dental pathology of southern sea otters (Enhydra lutris nereis).

    PubMed

    Winer, J N; Liong, S M; Verstraete, F J M

    2013-01-01

    Skulls (n = 1,205) of southern sea otters were examined macroscopically according to defined criteria. The museum specimens, acquired from strandings, varied in age from juvenile to adult, with an equal sex distribution. The results from all young adult and adult specimens were pooled according to tooth type. Ninety-two percent of teeth were available for examination, with 6.5% artifactually absent, 0.6% deemed absent due to acquired tooth loss and 0.03% deemed congenitally absent. All teeth were normal in morphology, except for three pairs of fused teeth, including two instances of fused maxillary first incisor teeth. Supernumerary teeth were associated with 97 normal teeth (most commonly maxillary canine teeth) in 68 specimens. At least one persistent deciduous tooth was present in six skulls, two of which were from adults. The majority (94.6%) of alveoli, either with or without teeth, were not associated with bony changes consistent with periodontitis; however, the majority (74.4%) of specimens did have at least one tooth associated with mild periodontitis. The mesial root of the mandibular third premolar tooth was the most common location at which periodontal hard tissue lesions were observed (56.6%). Ten sea otters had lesions consistent with focal enamel hypoplasia. Approximately half of the teeth (52.0%) were abraded; almost all adult specimens (98.1%) contained at least one abraded tooth, while fewer young adults were affected (76.4%). Tooth fractures were uncommon, affecting 1,343 teeth (4.5%). Periapical lesions were associated with 409 teeth (1.3%) in a total of 176 specimens, and these would likely have caused considerable morbidity while the animals were alive. PMID:23348015

  15. The dental pathology of southern sea otters (Enhydra lutris nereis).

    PubMed

    Winer, J N; Liong, S M; Verstraete, F J M

    2013-01-01

    Skulls (n = 1,205) of southern sea otters were examined macroscopically according to defined criteria. The museum specimens, acquired from strandings, varied in age from juvenile to adult, with an equal sex distribution. The results from all young adult and adult specimens were pooled according to tooth type. Ninety-two percent of teeth were available for examination, with 6.5% artifactually absent, 0.6% deemed absent due to acquired tooth loss and 0.03% deemed congenitally absent. All teeth were normal in morphology, except for three pairs of fused teeth, including two instances of fused maxillary first incisor teeth. Supernumerary teeth were associated with 97 normal teeth (most commonly maxillary canine teeth) in 68 specimens. At least one persistent deciduous tooth was present in six skulls, two of which were from adults. The majority (94.6%) of alveoli, either with or without teeth, were not associated with bony changes consistent with periodontitis; however, the majority (74.4%) of specimens did have at least one tooth associated with mild periodontitis. The mesial root of the mandibular third premolar tooth was the most common location at which periodontal hard tissue lesions were observed (56.6%). Ten sea otters had lesions consistent with focal enamel hypoplasia. Approximately half of the teeth (52.0%) were abraded; almost all adult specimens (98.1%) contained at least one abraded tooth, while fewer young adults were affected (76.4%). Tooth fractures were uncommon, affecting 1,343 teeth (4.5%). Periapical lesions were associated with 409 teeth (1.3%) in a total of 176 specimens, and these would likely have caused considerable morbidity while the animals were alive.

  16. Tissue partitioning of micro-essential metals in the vent bivalve Bathymodiolus azoricus and associated organisms (endosymbiont bacteria and a parasite polychaete) from geochemically distinct vents of the Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Kádár, Enikõ; Costa, Valentina; Santos, Ricardo S.; Powell, Jonathan J.

    2006-07-01

    Hydrothermal communities are built on highly specialised organisms possessing effective adaptation mechanisms to tolerate elevated levels of toxic heavy metals typical of these extreme habitats. Bioavailability and tissue compartmentalisation of micro-essential metals (Cu, Zn, and Fe) were investigated in the bivalve Bathymodiolus azoricus from three geochemically distinct hydrothermal vents (Rainbow, Lucky Strike, Menez Gwen). Additionally , in order to make inferences on the effect of biological interactions on the metal uptake, the bivalves' endosymbiont bacteria and commensal parasite Branchipolynoe seepensis were analysed for metal bioaccumulation. Micro-essential metal concentrations in byssus threads exceeded many-fold concentrations in the gill and digestive gland, which in turn were consistently one order of magnitude above levels measured in the mantle. In spite of its high metal concentrations, the byssus is unlikely to be an active bioaccumulator. Its high surface to mass ratio and its binding sites for metals suggest a reversible adsorption of micro-essential metals in the vent mussel. Inter-site comparison showed highest Fe concentrations in tissues of mussels from the Rainbow site, whereas Zn and Cu in all tissues were highest in mussels from the Lucky Strike site, reflecting metal concentrations in the water surrounding macro-invertebrates at these vent sites. The omnipresence of the commensal parasite polychaete in gills of B. azoricus from the Lucky Strike vent field, unlike the other sites, is suggested to be an adaptation to the typically elevated Fe concentrations in the water column near mussel beds. Unprecedented Fe concentrations measured in the digestive gland of mussels from the Rainbow site (4000 μg g - 1 , three times higher than levels in bivalves from polluted sites) call for further post-capture ecotoxicological investigations of potentially novel Fe-handling strategies. We provide the first information on the bioaccumulation

  17. Bioavailability of 2,3,7,8-TCDD, 2,3,7,8-TCDF and PCBs to marine benthos from passaic river sediments

    SciTech Connect

    Rubinstein, N.I.; Pruell, R.J.; Taplin, B.K.; LiVolsi, J.A.; Norwood, C.B.

    1990-01-01

    The bioaccumulation and depuration of 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran and polychlorinated biphenyls by marine benthos exposed to environmentally contaminated sediment were measured in a laboratory study. Sandworms (Nereis virens), clams (Macoma nasuta) and shrimp (Palaemonetes pugio) were exposed to sediment from the Passaic River, New Jersey for up to 180 days. Worms accumulated the highest concentrations of these compounds. Uptake and depuration rates were slowest in the worms and most rapid in the clams.

  18. Allantoinase in the marine polychaete Eudistylia vancouveri

    USGS Publications Warehouse

    Passino, Dora R.M.; Brown, G.W.

    1976-01-01

    Allantoinase, an enzyme in the purine-urea cycle, was found in Eudistylia vancouveri (Polychaeta). The enzyme had a pH optimum at 7.6. The Km was 0.012 M allantoin, and the Arrhenius energy of activation was 12.6 to 14.6 kcal/mol.

  19. Metals in sediments and benthic organisms in the Mersey estuary

    NASA Astrophysics Data System (ADS)

    Langston, W. J.

    1986-08-01

    Concentrations of twelve metals were determined in sediments, seaweed ( Fucus vesiculosus), winkles ( Littorina littorea), polychaetes ( Nereis diversicolor), suspension feeding bivalves ( Mytilus edulis, Cerastoderma edule) and deposit feeding bivalves ( Macoma balthica, Scrobicularia plana) collected from the Mersey estuary between April 1980 and June 1984. Sediments and organisms in the Mersey are moderately contaminated with most of the metals measured, but mercury concentrations are consistently higher than in other United Kingdom estuaries. Comparisons with other sites in the North West of England indicate that mercury residues in organisms, though primarily dependent on sediment concentrations, are also influenced by complexation with particulate organic matter which reduces the availability of mercury. The biological availability of arsenic in Mersey sediments is similarly influenced by complexation with iron oxyhydroxides. Nereis diversicolor and Macoma balthica are the most suitable indicator species in terms of abundance and widespread distribution along the estuary, and, for the majority of metals, tissue concentrations increase upstream, reflecting corresponding gradients in sediment contamination. However mid-estuarine peaks for tin, chromium copper and nickel in Nereis indicate more localised inputs to the estuary. Correlations between lead in sediments and organisms are poor; it is suggested that hydrophilic alkyl lead compounds may be the predominant biologically available forms. Progressive reductions in mercury contamination in sediments and mercury and lead in organisms have occurred in recent years, which coincide with efforts to reduce inputs of these metals to teh Mersey estuary.

  20. Sulfurimonas paralvinellae sp. nov., a novel mesophilic, hydrogen- and sulfur-oxidizing chemolithoautotroph within the Epsilonproteobacteria isolated from a deep-sea hydrothermal vent polychaete nest, reclassification of Thiomicrospira denitrificans as Sulfurimonas denitrificans comb. nov. and emended description of the genus Sulfurimonas.

    PubMed

    Takai, Ken; Suzuki, Masae; Nakagawa, Satoshi; Miyazaki, Masayuki; Suzuki, Yohey; Inagaki, Fumio; Horikoshi, Koki

    2006-08-01

    A novel mesophilic bacterium, strain GO25(T), was isolated from a nest of hydrothermal vent polychaetes, Paralvinella sp., at the Iheya North field in the Mid-Okinawa Trough. Cells were motile short rods with a single polar flagellum. Growth was observed between 4 and 35 degrees C (optimum 30 degrees C; 13-16 h doubling time) and between pH 5.4 and 8.6 (optimum pH 6.1). The isolate was a facultatively anaerobic chemolithoautotroph capable of growth using molecular hydrogen, elemental sulfur or thiosulfate as the sole energy source, carbon dioxide as the sole carbon source, ammonium or nitrate as the sole nitrogen source and elemental sulfur, thiosulfate or yeast extract as the sole sulfur source. Strain GO25(T) represents the first deep-sea epsilonproteobacterium capable of growth by both hydrogen and sulfur oxidation. Nitrate or molecular oxygen (up to 10 % partial pressure) could serve as the sole electron acceptor to support growth. Metabolic products of nitrate reduction shifted in response to the electron donor provided. The G+C content of genomic DNA was 37.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel isolate belonged to the genus Sulfurimonas and was most closely related to Sulfurimonas autotrophica OK10(T) (96.3 % sequence similarity). DNA-DNA hybridization demonstrated that the novel isolate could be differentiated genotypically from Sulfurimonas autotrophica OK10(T). On the basis of the physiological and molecular properties of the novel isolate, the name Sulfurimonas paralvinellae sp. nov. is proposed, with strain GO25(T) (=JCM 13212(T)=DSM 17229(T)) as the type strain. Thiomicrospira denitrificans DSM 1251(T) (=ATCC 33889(T)) is phylogenetically associated with Sulfurimonas autotrophica OK10(T) and Sulfurimonas paralvinellae GO25(T). Based on the phylogenetic relationship between Thiomicrospira denitrificans DSM 1251(T), Sulfurimonas autotrophica OK10(T) and Sulfurimonas paralvinellae GO25(T), we propose the

  1. Accumulation of polychlorinated organic contaminants from sediment by three benthic marine species

    SciTech Connect

    Pruell, R.J.; Rubinstein, N.I.; Taplin, B.K.; LiVolsi, J.A.; Bowen, R.D.

    1993-01-01

    A laboratory experiment was conducted to measure the accumulation of selected polychlorinated compounds by marine benthos exposed to environmentally contaminated sediment. Sandworms (Nereis virens), clams (Macoma nasuta), and grass shrimp (Palaemonetes pugio) were exposed to sediment collected from the Passaic River, New Jersey. All three species accumulated 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF) and polychlorinated biphenyls (PCBs) from the sediment. In addition, a recently identified sulfur containing analog of tetrachlorinated dibenzofurans. The objectives of the study were to determine the relative bioavailability of 2,3,7,8-TCDD, 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF) and selected PCB congeners from bottom sediments as well as to examine the relationship between contaminant concentrations in sediments and biota.

  2. Spermatogenesis and sperm ultrastructure in the polychaete genus Ophryotrocha (Dorvilleidae)

    NASA Astrophysics Data System (ADS)

    Pfannenstiel, Hans-Dieter; Grünig, Charlotte

    1990-06-01

    The details of spermatogenesis and spermiogenesis are described for Ophryotrocha puerilis. The ultrastructure of mature sperm is shown for O. puerilis, O. hartmanni, O. gracilis, O. diadema, O. labronica, and O. notoglandulata. Clusters of sixteen cells each are proliferated by two stem cells in each setigerous segment of O. puerilis representing the very early stages of both oogenesis and spermatogenesis. In each spermatocyte-I cluster, the cells are interconnected by cytoplasmic bridges. Early, clusters are enveloped by peritoneal sheath cells. These transient gonad walls break down prior to meiosis. The meiotic processes may start in the clusters with the cells still interconnected, or during breakdown of the original cluster, giving rise to smaller subclusters of both spermatocytes I and spermatocytes II with various numbers of cells. Finally, spermatid tetrads are present. As spermiogenesis progresses, the tetrads disintegrate. Golgi vesicles in both spermatocytes and spermatids contain electron-dense material, presumably preacrosomal. The acrosome is formed by such vesicles. In the six species studied here, the acrosomes appear to be of a similar overall structure but are of different shape. Centrioles are usually located beneath the acrosome. The distal centriole forms the basal body of a flagellum-like cytoplasmic process. The microtubules of these flagellar equivalents do not show a normal ciliar arrangement. The flagellar equivalent appears to be non-motile. In O. hartmanni and in O. notoglandulata, a flagellar equivalent is missing. Microtubules originating from the proximal end of the distal centriole stretch to the nuclear envelope. This feature appears to be especially conspicuous in O. puerilis and in O. labronica. In O. labronica and in O. notoglandulata, bundles of microtubules paralleling the cell perimeter appear to stabilise the sperm. Various numbers of mitochondria are either randomly distributed around the nucleus or accumulate on one side, often directly under the acrosome.

  3. Hydrocarbon Bioaccumulation from contaminated sediment by a deposit feeding polychaete

    SciTech Connect

    Weston, D.P. )

    1990-01-09

    This study examined the role of sediment organic carbon content in aromatic hydrocarbon bioaccumulation and assessed the importance of two routes of hydrocarbon uptake: (1) uptake of the dissolved contaminant fraction from interstitial or overlying water; and (2) uptake of the particulate contaminant fraction from ingested sediments. The lugworm, Abarenicola pacifica, was exposed to three sediments contaminated with [[sup 3]H] benzo(a)pyrene (BaP). By manipulating the organic content of these sediments it was possible to establish three treatments with similar BaP concentrations in the interstitial water, but differing in the amount of BaP in the bulk sediment. BaP bioaccumulation over the first few days of exposure was correlated with feeding rate, implicating ingested sediments as a source of implicating ingested sediments as a source of BaP. The greatest body burden, however, was attained in those individuals held in sediments with the lowest organic carbon content and the lowest BaP concentration. Body burden at steady state was not correlated with either BaP concentrations in bulk sediment (dry weight or organic normalized basis) or the interstitial water. Increased organic matter decreased BaP bioavailability in a non-linear fashion. Bioaccumulation factors relative to water and organic content were relatively constant between 1 and 2% organic carbon in the sediment, but these same accumulation factors substantially underestimated body burden if applied to sandy sediments with little (0.3%) organic carbon.

  4. Sound production and reception in southern sea otters (Enhydra lutris nereis).

    PubMed

    Ghoul, Asila; Reichmuth, Colleen

    2012-01-01

    Because of their dependence on a highly restricted coastal habitat, Enhydra lutris is especially vulnerable to a variety of different environmental and anthropogenic threats. This species is presently listed as threatened and is protected throughout the northern and southern portions of its range.Resource managers are presently faced with uncertainty when responding to and prioritizing potential threats to these animals due to insufficient understanding of the factors that may disturb or disrupt normal behavior patterns both above and below the water's surface. The objective of these studies was to obtain direct measurements of the source characteristics of vocalizations and the limits of auditory reception in Enhydra lutris. These data are necessary to form a basic but essential under-standing of bioacoustics in this species. To further develop this knowledge base, psychoacoustic profiles of aerial and underwater hearing sensitivity as a function of sound frequency are imperative to adequately consider sea otters alongside other marine mammals within the issue of anthropogenic impacts. These studies are presently ongoing i n our laboratory. A s these coastal-living carnivores have only recently transitioned to a marine lifestyle, an improved understanding of their acoustic communication and auditory adaptations will also provide insight into their evolutionary biology and behavioral ecology as well as the evolutionary pressures shaping underwater perception in marine mammals.

  5. Novel Bartonella infection in northern and southern sea otters (Enhydra lutris kenyoni and Enhydra lutris nereis).

    PubMed

    Carrasco, Sebastian E; Chomel, Bruno B; Gill, Verena A; Kasten, Rickie W; Maggi, Ricardo G; Breitschwerdt, Edward B; Byrne, Barbara A; Burek-Huntington, Kathleen A; Miller, Melissa A; Goldstein, Tracey; Mazet, Jonna A K

    2014-06-01

    Since 2002, vegetative valvular endocarditis (VVE), septicemia and meningoencephalitis have contributed to an Unusual Mortality Event (UME) of northern sea otters in southcentral Alaska. Streptococcal organisms were commonly isolated from vegetative lesions and organs from these sea otters. Bartonella infection has also been associated with bacteremia and VVE in terrestrial mammals, but little is known regarding its pathogenic significance in marine mammals. Our study evaluated whether Streptococcus bovis/equinus (SB/E) and Bartonella infections were associated with UME-related disease characterized by VVE and septicemia in Alaskan sea otter carcasses recovered 2004-2008. These bacteria were also evaluated in southern sea otters in California. Streptococcus bovis/equinus were cultured from 45% (23/51) of northern sea otter heart valves, and biochemical testing and sequencing identified these isolates as Streptococcus infantarius subsp. coli. One-third of sea otter hearts were co-infected with Bartonella spp. Our analysis demonstrated that SB/E was strongly associated with UME-related disease in northern sea otters (P<0.001). While Bartonella infection was also detected in 45% (23/51) and 10% (3/30) of heart valves of northern and southern sea otters examined, respectively, it was not associated with disease. Phylogenetic analysis of the Bartonella ITS region allowed detection of two Bartonella species, one novel species closely related to Bartonella spp. JM-1, B. washoensis and Candidatus B. volans and another molecularly identical to B. henselae. Our findings help to elucidate the role of pathogens in northern sea otter mortalities during this UME and suggested that Bartonella spp. is common in sea otters from Alaska and California.

  6. Characterization of the Temporomandibular Joint of Southern Sea Otters (Enhydra lutris nereis).

    PubMed

    Lieske, Danielle; Vapniarsky, Natalia; Verstraete, Frank J M; Leale, Dustin M; Young, Colleen; Arzi, Boaz

    2015-01-01

    The structure-function relationship of the temporomandibular joint (TMJ) of southern sea otter has largely not been described. This study aims to describe the histological, biochemical, and biomechanical features of the TMJ disk in the southern sea otter. The TMJ disks from fresh cadaver heads of southern sea otter adult males (n = 8) and females (n = 8) acquired from strandings were examined. Following macroscopical evaluation, the TMJs were investigated for their histological, mechanical, and biochemical properties. We found that the sea otter TMJ disks are, in general, similar to other carnivores. Macroscopically, the TMJ disk was highly congruent, and the mandibular head was encased tightly by the mandibular fossa with a thin disk separating the joint into two compartments. Histologically, the articular surfaces were lined with dense fibrous connective tissue that gradually transitioned into one to two cell thick layer of hyaline-like cartilage. The disk fibers were aligned primarily in the rostrocaudal direction and had occasional lacuna with chondrocyte-like cells. The disk was composed primarily of collagen type 1. Biochemical analysis indicates sulfated glycosaminoglycan content lower than other mammals, but significantly higher in male sea otters than female sea otters. Finally, mechanical analysis demonstrated a disk that was not only stronger and stiffer in the rostrocaudal direction than the mediolateral direction but also significantly stronger and stiffer in females than males. We conclude that the congruent design of the TMJ, thin disk, biochemical content, and mechanical properties all reflect a structure-function relationship within the TMJ disk that is likely designed for the sea otter's hard diet and continuous food intake.

  7. Polycyclic Aromatic Acids Are Primary Metabolites of Alkyl-PAHs-A Case Study with Nereis diversicolor.

    PubMed

    Malmquist, Linus M V; Selck, Henriette; Jørgensen, Kåre B; Christensen, Jan H

    2015-05-01

    Although concentrations of alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) in oil-contaminated sediments are higher than those of unsubstituted PAHs, only little attention has been given to metabolism and ecotoxicity of alkyl-PAHs. In this study we demonstrated that metabolism of alkyl-PAHs primarily forms polycyclic aromatic acids (PAAs). We generalize this to other alkyl-PAHs, based on literature and the present study of the metabolism of 1-methylphenanthrene, 3,6-dimethylphenanthrene, and 1-, 2-, 3-, and 6-methylchrysene related to their unsubstituted parent PAHs. Also, we observed that body burdens and production of PAAs was related to the position of the methyl group, showing the same isomer specific preferences as for microbial degradation of alkyl-PAHs. We detected a high production of PAAs, and larger metabolism of alkyl-PAHs than their unsubstituted parent PAHs. We therefore propose that carboxylic acid metabolites of alkyl-PAHs have the potential of constituting a new class of contaminants in marine waters that needs attention in relation to ecological risk assessments.

  8. Characterization of the Temporomandibular Joint of Southern Sea Otters (Enhydra lutris nereis)

    PubMed Central

    Lieske, Danielle; Vapniarsky, Natalia; Verstraete, Frank J. M.; Leale, Dustin M.; Young, Colleen; Arzi, Boaz

    2015-01-01

    The structure–function relationship of the temporomandibular joint (TMJ) of southern sea otter has largely not been described. This study aims to describe the histological, biochemical, and biomechanical features of the TMJ disk in the southern sea otter. The TMJ disks from fresh cadaver heads of southern sea otter adult males (n = 8) and females (n = 8) acquired from strandings were examined. Following macroscopical evaluation, the TMJs were investigated for their histological, mechanical, and biochemical properties. We found that the sea otter TMJ disks are, in general, similar to other carnivores. Macroscopically, the TMJ disk was highly congruent, and the mandibular head was encased tightly by the mandibular fossa with a thin disk separating the joint into two compartments. Histologically, the articular surfaces were lined with dense fibrous connective tissue that gradually transitioned into one to two cell thick layer of hyaline-like cartilage. The disk fibers were aligned primarily in the rostrocaudal direction and had occasional lacuna with chondrocyte-like cells. The disk was composed primarily of collagen type 1. Biochemical analysis indicates sulfated glycosaminoglycan content lower than other mammals, but significantly higher in male sea otters than female sea otters. Finally, mechanical analysis demonstrated a disk that was not only stronger and stiffer in the rostrocaudal direction than the mediolateral direction but also significantly stronger and stiffer in females than males. We conclude that the congruent design of the TMJ, thin disk, biochemical content, and mechanical properties all reflect a structure–function relationship within the TMJ disk that is likely designed for the sea otter’s hard diet and continuous food intake. PMID:26664997

  9. Characterization of the Temporomandibular Joint of Southern Sea Otters (Enhydra lutris nereis).

    PubMed

    Lieske, Danielle; Vapniarsky, Natalia; Verstraete, Frank J M; Leale, Dustin M; Young, Colleen; Arzi, Boaz

    2015-01-01

    The structure-function relationship of the temporomandibular joint (TMJ) of southern sea otter has largely not been described. This study aims to describe the histological, biochemical, and biomechanical features of the TMJ disk in the southern sea otter. The TMJ disks from fresh cadaver heads of southern sea otter adult males (n = 8) and females (n = 8) acquired from strandings were examined. Following macroscopical evaluation, the TMJs were investigated for their histological, mechanical, and biochemical properties. We found that the sea otter TMJ disks are, in general, similar to other carnivores. Macroscopically, the TMJ disk was highly congruent, and the mandibular head was encased tightly by the mandibular fossa with a thin disk separating the joint into two compartments. Histologically, the articular surfaces were lined with dense fibrous connective tissue that gradually transitioned into one to two cell thick layer of hyaline-like cartilage. The disk fibers were aligned primarily in the rostrocaudal direction and had occasional lacuna with chondrocyte-like cells. The disk was composed primarily of collagen type 1. Biochemical analysis indicates sulfated glycosaminoglycan content lower than other mammals, but significantly higher in male sea otters than female sea otters. Finally, mechanical analysis demonstrated a disk that was not only stronger and stiffer in the rostrocaudal direction than the mediolateral direction but also significantly stronger and stiffer in females than males. We conclude that the congruent design of the TMJ, thin disk, biochemical content, and mechanical properties all reflect a structure-function relationship within the TMJ disk that is likely designed for the sea otter's hard diet and continuous food intake. PMID:26664997

  10. Applying population genetics for authentication of marine fish: the case of saithe (Pollachius virens).

    PubMed

    Behrmann, Konstanze; Rehbein, Hartmut; von Appen, Annika; Fischer, Markus

    2015-01-28

    The number of fishery products with a quite detailed description of the origin is increasing. This trend is driven by the interest of consumers and the fight against illegal unregulated and unreported fisheries. Unfortunately, there is a lack of methods to prove this information experimentally besides the document-based traceability assessments. For marine fish population genetics is a promising strategy, but research is concentrated only on a few species. Saithe is a commercially important fish species, despite the fact that genetic knowledge is scarce regarding the specification of populations. For a comparative study cost- and time-effective strategies were tested: We found RAPD-PCR to be a useful method for low-budget research or prestudies. Adoption of microsatellites from closely related species turned out to be possible with limited success quota. Our results suggest a clustered structure of populations within the Northeast Atlantic, probably overlapping in the northern North Sea.

  11. Food supply for waders (Aves: Charadrii) in an estuarine area in the Bay of Cádiz (SW Iberian Peninsula)

    NASA Astrophysics Data System (ADS)

    Masero, José A.; Pérez-González, Maite; Basadre, Marta; Otero-Saavedra, Mónica

    1999-07-01

    We studied the composition, density, size distribution and biomass of the food supply for waders in an estuarine area in the Bay of Cádiz (SW Iberian Peninsula), in winter (January-February) and in the pre-migratory period (late March). The estuarine area comprises an intertidal mudflat and an adjacent salina or salt-pan. On the intertidal mudflat, the biomass was 53 and 37 g AFDW .m -2in winter and the pre-migratory period, respectively. The main food source on mudflat was the polychaete Nereis diversicolor (44-54 % of the total biomass). On the other hand, the biomass in the salina was comparatively very poor, ranging from 0.008 to 0.079 g AFDW .m -2in winter and ranging from 0.011 to 0.09 g AFDW in late March. The main source of food in the salina was the crustacean Artemia. The total biomass on the mudflat during the pre-migratory period was 1.4 times lower than in February. This depletion could be caused by wader predation, mainly by Nereis diversicolor consumption. Although the potential food on the mudflats could allow high intertidal densities of waders, the availability of high tide foraging areas in the salina seems to contribute to the maintenance of these high intertidal densities.

  12. Enteric bacterial pathogen detection in southern sea otters (Enhydra lutris nereis) is associated with coastal urbanization and freshwater runoff

    PubMed Central

    Miller, Melissa A.; Byrne, Barbara A.; Jang, Spencer S.; Dodd, Erin M.; Dorfmeier, Elene; Harris, Michael D.; Ames, Jack; Paradies, David; Worcester, Karen; Jessup, David A.; Miller, Woutrina A.

    2009-01-01

    Although protected for nearly a century, California’s sea otters have been slow to recover, in part due to exposure to fecally-associated protozoal pathogens like Toxoplasma gondii and Sarcocystis neurona. However, potential impacts from exposure to fecal bacteria have not been systematically explored. Using selective media, we examined feces from live and dead sea otters from California for specific enteric bacterial pathogens (Campylobacter, Salmonella, Clostridium perfringens, C. difficile and Escherichia coli O157:H7), and pathogens endemic to the marine environment (Vibrio cholerae, V. parahaemolyticus and Plesiomonas shigelloides). We evaluated statistical associations between detection of these pathogens in otter feces and demographic or environmental risk factors for otter exposure, and found that dead otters were more likely to test positive for C. perfringens, Campylobacter and V. parahaemolyticus than were live otters. Otters from more urbanized coastlines and areas with high freshwater runoff (near outflows of rivers or streams) were more likely to test positive for one or more of these bacterial pathogens. Other risk factors for bacterial detection in otters included male gender and fecal samples collected during the rainy season when surface runoff is maximal. Similar risk factors were reported in prior studies of pathogen exposure for California otters and their invertebrate prey, suggesting that land-sea transfer and/or facilitation of pathogen survival in degraded coastal marine habitat may be impacting sea otter recovery. Because otters and humans share many of the same foods, our findings may also have implications for human health. PMID:19720009

  13. Natural arsenic contaminated diets perturb reproduction in fish.

    PubMed

    Boyle, David; Brix, Kevin V; Amlund, Heidi; Lundebye, Anne-Katrine; Hogstrand, Christer; Bury, Nic R

    2008-07-15

    The toxicological effect of natural diets elevated in metals on reproduction in fish is poorly understood. The reproductive output of zebrafish fed the polychaete Nereis diversicolor collected from a metal-impacted estuary, Restronguet Creek, Cornwall, UK, was compared to fish fed N. diversicolor collected from a nonmetal impacted estuary, Blackwater, Essex, UK. Fish fed the metal laden N. diversicolorfor 68 days showed reduced reproductive output, characterized by reduced cumulative egg production (47%), cumulative number of spawns (30%), as well as reduced average number of eggs produced per spawn and % hatch rate. The mRNA transcript levels of the egg-yolk protein vitellogenin was also reduced 1.5 fold in the livers of female fish fed metal-laden N. diversicolor. No difference was seen between the lipid, protein, or moisture content of the two diets and no difference in growth was seen between the two fish populations. The Restronguet Creek polychaetes have elevated arsenic, cadmium, copper, zinc, lead, and silver body burdens, but the only element found to accumulate in the tissues of zebrafish fed this diet was As. The As in these N. diversicolor was found to be predominantly potentially toxic inorganic As species, 58% of total As content, which is unusual for aquatic organisms where arsenic is typically biotransformed into less toxic organoarsenical compounds. These results demonstrate that reproduction in fish is a sensitive target of exposure to a natural diet contaminated with As and this exposure route could be of significance to the health of fish populations. PMID:18754393

  14. Taxonomy of reproductive Nereididae (Annelida) in multispecies swarms at Ambon Island, Indonesia

    PubMed Central

    Pamungkas, Joko; Glasby, Christopher J.

    2015-01-01

    Abstract Multispecies, or mass, spawning of different invertebrate species is well known for coral reef systems; however, incidences involving polychaetes are poorly documented. In this study we report on mass swarming, prior to spawning, of Nereididae at Ambon Island, Maluku, on three occasions: in 1866, inferred from an historical sample deposited in Naturalis, Leiden, and in March, 2009 and 2014, based on newly collected samples. The 2009 and 2014 events co-occurred with spawning of other polychaetes, known locally as wawo and including the widespread Indo-Pacific eunicid, Palola viridis (Gray in Stair). Ten species of reproductive Nereididae are described, including Composetia marmorata (Horst) new combination, formerly Ceratonereis marmorata; epitokous modifications are described for both sexes of each species including taxonomically important features such as body colour and number of pre-natatory chaetigers. Three distinct types of natatory region morphologies are recognized, which appear to characterise groups of genera. The ten new records brings to 13 the total number of nereidid species known to undergo mass swarming at Ambon Island; a key to the 13 species is provided. Species composition varies slightly between the three time periods: four species were common between all three periods, five species were in common between 1866 and 2014, and four species were in common between 1995 and 2009/14. Two species of Neanthes and one of Nereis are identified as potentially new and will be described in subsequent papers. PMID:26448711

  15. 40 CFR 180.1100 - Gliocladium virens isolate GL-21; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... as a fungicide for inoculation of plant growth media in greenhouses or on terrestrial food crops...; exemption from the requirement of a tolerance. 180.1100 Section 180.1100 Protection of Environment... requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues...

  16. 40 CFR 180.1100 - Gliocladium virens isolate GL-21; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... as a fungicide for inoculation of plant growth media in greenhouses or on terrestrial food crops...; exemption from the requirement of a tolerance. 180.1100 Section 180.1100 Protection of Environment... requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues...

  17. 40 CFR 180.1100 - Gliocladium virens isolate GL-21; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... as a fungicide for inoculation of plant growth media in greenhouses or on terrestrial food crops...; exemption from the requirement of a tolerance. 180.1100 Section 180.1100 Protection of Environment... requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues...

  18. Sediment contamination and associates laboratory-measured bioaccumulation in New York/New Jersey waterways

    SciTech Connect

    Rosman, L.B.; Barrows, E.S.

    1995-12-31

    Sediments from 10 New York/New Jersey waterways within the Hudson-Raritan Estuary and Long Island Sound were collected to depths representative of dredging activity. Composited core sediments representing each waterway were analyzed for metals, PAHs, PCBs, and pesticides. To assess bioaccumulation, sand worms (Nereis virens) and blunt-nose clams (Macoma nasuta) were exposed for 28 days to sediment composites and to New York Bight sediment. Tissues were analyzed for the same constituents as the sediment samples. The results highlight the range and magnitude of sediment contamination in NY/NJ waterways. Concentrations of some metals in sediments, compared with NY Bight sediment, were at least 10 times higher. Total PAHs reached 30,000 {micro}g/kg (dry weight). The sum of DDT, DDD, and DDE, the dominant pesticides, exceeded 3,000{micro}g/kg (dry weight). Total PCBs approached 3,000 {micro}g/kg (dry weight). Tissues exposed to sediments from several waterways bioaccumulated organic compounds at concentrations 10 times greater than those exposed to New York Bight sediments. Metals were bioaccumulated to a lesser degree. The presence and extent of bioaccumulated contaminants, along with sediment chemistry and benthic toxicity, create a profile characterizing each waterway.

  19. Spatial distribution of PAHs and associated laboratory-measured bioaccumulation in New York/New Jersey waterways

    SciTech Connect

    Rosman, L.B.; Barrows, E.S.

    1995-12-31

    Sediment core samples from New York/New Jersey waterways within the Hudson-Raritan Estuary and Long Island Sound were collected to depths representative of dredging activity. Sediment was also collected from a reference site in the New York Bight as a comparison. Composited core sediments representing each waterway were analyzed for PAHs, sediment grain size, and total organic carbon. To assess bioaccumulation, sand worms (Nereis virens) and blunt-nose clams (Macoma nasuta) were exposed for 28 days to sediment composites and to New York Bight sediment. Tissues were analyzed for the same constituents as the sediment samples, as well as for lipid content. The results highlight the range and magnitude of PAH concentrations in sediments of NY/NJ waterways. Concentrations of total PAHs ranged from undetected to 30,000 {micro}g/kg (dry weight). Tissues exposed to sediments from several waterways bioaccumulated organic compounds at concentrations as much as 10 times greater than those exposed to New York Bight sediments. The presence and extent of bioaccumulated compounds, along with benthic toxicity data, create a profile characterizing each waterway.

  20. Modeling of Bioaccumulation in Marine Benthic Invertebrates Using a Multispecies Experimental Approach.

    PubMed

    Diepens, Noël J; Van den Heuvel-Greve, Martine J; Koelmans, Albert A

    2015-11-17

    The causal links between species traits and bioaccumulation by marine invertebrates are poorly understood. We assessed these links by measuring and modeling polychlorinated biphenyl bioaccumulation by four marine benthic species. Uniformity of exposure was achieved by testing each species in the same aquarium, separated by enclosures, to ensure that the observed variability in bioaccumulation was due to species traits. The relative importance of chemical uptake from pore water or food (organic matter, OM) ingestion was manipulated by using artificial sediment with different OM contents. Biota sediment accumulation factors (BSAFs) ranged from 5 to 318, in the order Nereis virens < Arenicola marina ≈ Macoma balthica < Corophium volutator. Calibration of a kinetic model provided species-specific parameters that represented the key species traits, thus illustrating how models provide an opportunity to read across benthic species with different feeding strategies. Key traits included species-specific differentiation between (1) ingestion rates, (2) ingestion of suspended and settled OM, and (3) elimination rates. The high BSAF values and their concomitant variability across the species challenges approaches for exposure assessment based on pore water concentration analysis and equilibrium partition theory. We propose that combining multienclosure testing and modeling will substantially improve exposure assessment in sediment toxicity tests.

  1. Impact of a novel protein meal on the gastrointestinal microbiota and the host transcriptome of larval zebrafish Danio rerio

    PubMed Central

    Rurangwa, Eugene; Sipkema, Detmer; Kals, Jeroen; ter Veld, Menno; Forlenza, Maria; Bacanu, Gianina M.; Smidt, Hauke; Palstra, Arjan P.

    2015-01-01

    Larval zebrafish was subjected to a methodological exploration of the gastrointestinal microbiota and transcriptome. Assessed was the impact of two dietary inclusion levels of a novel protein meal (NPM) of animal origin (ragworm Nereis virens) on the gastrointestinal tract (GIT). Microbial development was assessed over the first 21 days post egg fertilization (dpf) through 16S rRNA gene-based microbial composition profiling by pyrosequencing. Differentially expressed genes in the GIT were demonstrated at 21 dpf by whole transcriptome sequencing (mRNAseq). Larval zebrafish showed rapid temporal changes in microbial colonization but domination occurred by one to three bacterial species generally belonging to Proteobacteria and Firmicutes. The high iron content of NPM may have led to an increased relative abundance of bacteria that were related to potential pathogens and bacteria with an increased iron metabolism. Functional classification of the 328 differentially expressed genes indicated that the GIT of larvae fed at higher NPM level was more active in transmembrane ion transport and protein synthesis. mRNAseq analysis did not reveal a major activation of genes involved in the immune response or indicating differences in iron uptake and homeostasis in zebrafish fed at the high inclusion level of NPM. PMID:25983694

  2. In situ quantification of mitochondrial respiration in permeabilized fibers of a marine invertebrate with low aerobic capacity.

    PubMed

    Pichaud, Nicolas; Rioux, Pierre; Blier, Pierre U

    2012-04-01

    The aim of this study was to design a protocol to allow the assessment of normal and alternative pathways for electron transport in mitochondria using an in situ approach (on permeabilized fibers) in high-resolution respirometry. We measured the oxygen consumption of permeabilized fibers from Nereis (Neanthes) virens with different substrates and the presence of ADP. To estimate the alternative oxidase (AOX) activity, antimycin A was introduced in order to inhibit complex III. Moreover, the apparent complex IV (COX) excess capacity was evaluated using different substrates to assess the implication of this complex in the partitioning of electrons during its progressive inhibition. Our in situ method enabled to quantify the activity of the normal COX pathway as well as the AOX pathway when different substrates were oxidized by either complex I, complex II or both. Using this approach, we confirmed that according to the substrates used, each pathway has a different role and consequently is otherwise involved in the partitioning of electrons through the electron transport system, and suggested that the AOX activity is triggered not only by the redox state of the cell but also by the type of substrates provided to mitochondria. PMID:22244894

  3. Biogeochemical studies of technetium in marine and estuarine ecosystems. Progress report, 1 July 1979-30 June 1980

    SciTech Connect

    Beasley, T. M.

    1980-01-01

    Progress is reported in research dealing with the biogeochemical behavior of technetium in marine and estuarine ecosystems. Studies were planned to elaborate the biokinetic behavior of Tc as TcO/sub 4//sup -/ in selected marine and estuarine organisms and to determine the affinity of TcO/sub 4//sup -/ for different marine sediments under oxygenated conditions. It is concluded that concentration factors for TcO/sub 4//sup -/ in bivalve molluscs (oysters and mussels) do not exceed 2 when calculated for whole animals and when uptake is directly from water. Direct uptake from water by limpets (archeogastropod) are very much lower than have been reported for red abalone (archeogastropod). Whole body concentration factors for TcO/sub 4//sup -/ in the plaice, Pleuronectes platessa, where uptake is directly from labeled seawater, do not exceed 10 at equilibrium. Both the lobster, Homarus gammaris and the polychaete, Nereis diversicolor appear to concentrate Tc efficiently from water labelled intially with TcO/sub 4//sup -/. Both plaice and rays (Raja clavata) fed /sup 95m/Tc labeled Nereis show an initial rapid loss of the isotope for approximately five days. Thereafter, loss is much reduced. Shrimp (Palaemon elegans), Cragnon sp.) and Crab (Cancer pagurus) show concentration factors similar to plaice (C.F. is less than 10). Isopods, however, have concentration factors of only 3 following four weeks exposure to labeled seawater. Uptake of TcO/sub 4//sup -/ by phytoplankton is extremely low, which precludes experiments in which TcO/sub 4//sup -/ labeled phytoplankton can be fed to either bivalve molluscs or microzooplankton. Sediment distribution coefficients for TcO/sub 4//sup -/ are essentially zero and are independent of sediment type in well oxygenated seawater. Experiments to date have shown that it is not possible to make generalizations concerning the bioavailability of TcO/sub 4//sup -/ to marine organisms.

  4. Recruitment in the sea: bacterial genes required for inducing larval settlement in a polychaete worm

    PubMed Central

    Huang, Ying; Callahan, Sean; Hadfield, Michael G.

    2012-01-01

    Metamorphically competent larvae of the marine tubeworm Hydroides elegans can be induced to metamorphose by biofilms of the bacterium Pseudoalteromonas luteoviolacea strain HI1. Mutational analysis was used to identify four genes that are necessary for metamorphic induction and encode functions that may be related to cell adhesion and bacterial secretion systems. No major differences in biofilm characteristics, such as biofilm cell density, thickness, biomass and EPS biomass, were seen between biofilms composed of P. luteoviolacea (HI1) and mutants lacking one of the four genes. The analysis indicates that factors other than those relating to physical characteristics of biofilms are critical to the inductive capacity of P. luteoviolacea (HI1), and that essential inductive molecular components are missing in the non-inductive deletion-mutant strains. PMID:22355742

  5. THE ULTRASTRUCTURE OF PHALACROCLEPTES VERRUCIFORMIS, AN UNCILIATED CILIATE PARASITIZING THE POLYCHAETE SCHIZOBRANCHIA INSIGNIS

    PubMed Central

    Lom, Jiři; Kozloff, Eugene N.

    1967-01-01

    The organization of Phalacrocleptes verruciformis is, in general, less complex than that of other ciliates, and no kinetosomes have been observed. However, there are numerous suctorial tentacles at the surface of the body, and the pellicle is characterized by close-set villus-like projections. The tentacles are very small (about 430 mµ in length, and about the same in diameter), but show the essential features of tentacles of suctorians such as Tokophrya, Podophrya, and Ephelota. Each tentacle is reinforced by eight pairs of fibrils arranged concentrically just within its wall, and contains a single missile-like body (MLB). The tentacles become attached to the cilia of the host, and serve for feeding upon the plasmatic contents of the cilia as well as for maintaining contact with the host. The MLB's originate in the endoplasm, and then migrate toward the surface and become incorporated into the tentacles. When feeding is initiated, the membrane covering the outermost nozzle-like portion of the MLB becomes continuous with the membrane of the cilium, and there are other changes in the structure of the MLB which suggest enzymatic activity. Although it appears that Phalacrocleptes is a suctorian, the complete absence of kinetosomes sets this organism apart from other members of the group. PMID:4962707

  6. The ultrastructure of Phalacroleptes verruciformis, an unciliated ciliate parasitizing the polychaete Schizobranchia insignis.

    PubMed

    Lom, J; Kozloff, E N

    1967-05-01

    The organization of Phalacrocleptes verruciformis is, in general, less complex than that of other ciliates, and no kinetosomes have been observed. However, there are numerous suctorial tentacles at the surface of the body, and the pellicle is characterized by close-set villus-like projections. The tentacles are very small (about 430 mmicro in length, and about the same in diameter), but show the essential features of tentacles of suctorians such as Tokophrya, Podophrya, and Ephelota. Each tentacle is reinforced by eight pairs of fibrils arranged concentrically just within its wall, and contains a single missile-like body (MLB). The tentacles become attached to the cilia of the host, and serve for feeding upon the plasmatic contents of the cilia as well as for maintaining contact with the host. The MLB's originate in the endoplasm, and then migrate toward the surface and become incorporated into the tentacles. When feeding is initiated, the membrane covering the outermost nozzle-like portion of the MLB becomes continuous with the membrane of the cilium, and there are other changes in the structure of the MLB which suggest enzymatic activity. Although it appears that Phalacrocleptes is a suctorian, the complete absence of kinetosomes sets this organism apart from other members of the group.

  7. Parasabella Bush, 1905, replacement name for the polychaete genus Demonax Kinberg, 1867 (Annelida, Polychaeta, Sabellidae)

    PubMed Central

    Tovar-Hernández, María Ana; Harris, Leslie H.

    2010-01-01

    Abstract Parasabella Bush, 1905 is reintroduced as a replacement name for Demonax Kinberg, 1867 (Annelida: Polychaeta: Sabellidae) which is a junior homonym of Demonax Thomson, 1860 (Insecta: Coleoptera: Cerambycidae). PMID:21594198

  8. A Polychaete's powerful punch: venom gland transcriptomics of Glycera reveals a complex cocktail of toxin homologs.

    PubMed

    von Reumont, Björn M; Campbell, Lahcen I; Richter, Sandy; Hering, Lars; Sykes, Dan; Hetmank, Jörg; Jenner, Ronald A; Bleidorn, Christoph

    2014-09-01

    Glycerids are marine annelids commonly known as bloodworms. Bloodworms have an eversible proboscis adorned with jaws connected to venom glands. Bloodworms prey on invertebrates, and it is known that the venom glands produce compounds that can induce toxic effects in animals. Yet, none of these putative toxins has been characterized on a molecular basis. Here we present the transcriptomic profiles of the venom glands of three species of bloodworm, Glycera dibranchiata, Glycera fallax and Glycera tridactyla, as well as the body tissue of G. tridactyla. The venom glands express a complex mixture of transcripts coding for putative toxin precursors. These transcripts represent 20 known toxin classes that have been convergently recruited into animal venoms, as well as transcripts potentially coding for Glycera-specific toxins. The toxins represent five functional categories: Pore-forming and membrane-disrupting toxins, neurotoxins, protease inhibitors, other enzymes, and CAP domain toxins. Many of the transcripts coding for putative Glycera toxins belong to classes that have been widely recruited into venoms, but some are homologs of toxins previously only known from the venoms of scorpaeniform fish and monotremes (stonustoxin-like toxin), turrid gastropods (turripeptide-like peptides), and sea anemones (gigantoxin I-like neurotoxin). This complex mixture of toxin homologs suggests that bloodworms employ venom while predating on macroscopic prey, casting doubt on the previously widespread opinion that G. dibranchiata is a detritivore. Our results further show that researchers should be aware that different assembly methods, as well as different methods of homology prediction, can influence the transcriptomic profiling of venom glands. PMID:25193302

  9. Influence of a tube-building polychaete on hydrothermal chimney mineralization

    SciTech Connect

    Juniper, S.K. ); Jonasson, I.R. ); Tunnicliffe, V. ); Southward, A.J. )

    1992-10-01

    High-temperature chimneys on the Juan de Fuca Ridge are the preferred habitat of the 'sulfide worm' (Paralvinella n. sp.). An investigation of interactions between the biology of the sulfide worm and chimney mineralization has led to a hypothesis linking formation of marcasite-pyrite crusts on chimney surfaces to colonization and tube-building by the worms. Marcasite precipitation beneath worm tubes and worm migration to newly formed areas of chimney together create a moving front of biomineralization that keeps pace with chimney growth. Sulfide oxidation by this organism can potentially produce enough S to form the FeS[sub 2] crusts. The marcasite-pyrite crusts act as a sealing layer within the outer chimney wall, reducing inflow of cold seawater or outflow of hydrothermal fluid. This may enhance temperature increases within the chimney conduit and hasten replacement of the early anhydrite matrix in the chimney wall by higher temperature sulfides.

  10. Complete mitochondrial genome sequence of the polychaete annelidPlatynereis dumerilii

    SciTech Connect

    Boore, Jeffrey L.

    2004-08-15

    Complete mitochondrial genome sequences are now available for 126 metazoans (see Boore 1999; Mitochondrial Genomics link at http://www.jgi.doe.gov), but the taxonomic representation is highly biased. For example, 80 are from a single phylum, Chordata, and show little variation for many molecular features. Arthropoda is represented by 16 taxa, Mollusca by eight, and Echinodermata by five, with only 17 others from the remaining {approx}30 metazoan phyla. With few exceptions (see Wolstenholme 1992 and Boore 1999) these are circular DNA molecules, about 16 kb in size, and encode the same set of 37 genes. A variety of non-standard names are sometimes used for animal mitochondrial genes; see Boore (1999) for gene nomenclature and a table of synonyms. Mitochondrial genome comparisons serve as a model of genome evolution. In this system, much smaller and simpler than that of the nucleus, are all of the same factors of genome evolution, where one may find tractable the changes in tRNA structure, base composition, genetic code, gene arrangement, etc. Further, patterns of mitochondrial gene rearrangements are an exceptionally reliable indicator of phylogenetic relationships (Smith et al.1993; Boore et al. 1995; Boore, Lavrov, and Brown 1998; Boore and Brown 1998, 2000; Dowton 1999; Stechmann and Schlegel 1999; Kurabayashi and Ueshima 2000). To these ends, we are sampling further the variation among major animal groups in features of their mitochondrial genomes.

  11. Reproductive biology of a new hesionid polychaete from the Great Barrier Reef.

    PubMed

    Pleijel, Fredrik; Rouse, Greg W

    2005-02-01

    We describe Lizardia hirschi, a new hesionid genus and species, from shallow water on the Great Barrier Reef. It is characterized by small size (maximally around 2 mm long) and by males with paired penes on the last segment or the pygidium. The sperm are elongated, with a conical acrosome; extended, cylindrical nucleus; and three mitochondria. The females have three to four pairs of eggs in segments 10-13, up to 150 microm in diameter. The female reproductive system consists of spermathecae, situated in the notopodia of segments 10-12, and oviducts opening ventrally on segment 11. Fertilization may be internal. The female (but not the male) reproductive system appears to be homologous to that in another small hesionid, capricornia. The phylogenetic position of L. hirschi within Hesionidae is currently uncertain due to the retention of many apparently larval features in the adults. PMID:15713814

  12. A new Capitella polychaete worm (Annelida: Capitellidae) living inside whale bones in the abyssal South Atlantic

    NASA Astrophysics Data System (ADS)

    Silva, Camila F.; Shimabukuro, Maurício; Alfaro-Lucas, Joan M.; Fujiwara, Yoshihiro; Sumida, Paulo Y. G.; Amaral, Antonia C. Z.

    2016-02-01

    A new species of the genus Capitella, Capitella iatapiuna sp. nov., has been found in deep sea whale-fall samples, São Paulo Ridge-Southwest Atlantic. The new species is mainly characterized by a bluntly rounded prostomium and a very distinct peristomium forming a complete ring. Ribosomal 16S sequences were obtained and used for inter-specific comparisons. This species is herein described and compared to others species of the genus. Its ecological role in the whale-fall community is also discussed.

  13. Cryptic species in marine polychaete and their independent introduction from North America to Europe.

    PubMed

    Bastrop, R; Jürss, K; Sturmbauer, C

    1998-02-01

    The vast body of ballast water carried across oceans by freight ships represents a major source for the introduction of foreign species into marine ecosystems. The worm Marenzelleria viridis, originally found only in North America, appeared in estuaries of the North Sea in 1979 and 6 years later also in the Baltic, where it has developed into a major faunal element. Two competing hypotheses are discussed here: either both populations owe their presence to a single introductory event in the North Sea, or each population originated from a separate introduction. Our phylogeographic analysis of Baltic, North Sea and American Marenzelleria, based on mitochondrial 16S rDNA sequences (326-bp segment) of 98 individuals from 17 localities on the North American, North Sea, and Baltic coasts not only favors the two-event hypothesis, but also separates the locations of origin for the introductions. Eighteen mitochondrial genotypes were identified altogether. In agreement with allozyme data, three lineages were identified: genotypes assigned to the same lineage differed from each other by up to 5 point mutations, and those assigned to different lineages differed by up to 17. The existence of three morphologically indistinguishable, and thus cryptic, species is therefore suggested. The individuals from the Baltic Sea probably originated from the Atlantic coast of the United States between Chesapeake Bay and Georgia, and the North Sea populations may stem from the U.S. coast region north of Chesapeake Bay to Nova Scotia. Despite their similar morphologies, the two European Marenzelleria species may differ ecologically with respect to their preference for habitat salinity. Assuming that transport via ballast water occurs quite frequently, we hypothesize that both European cryptic species of Marenzelleria may originally have been introduced to both the North Sea and the Baltic Sea but that neither of them was able to proliferate in both water bodies owing to their differential physiological performances at high and low salinities.

  14. Toxicity and accumulation of silver nanoparticles during development of the marine polychaete Platynereis dumerilii.

    PubMed

    García-Alonso, Javier; Rodriguez-Sanchez, Neus; Misra, Superb K; Valsami-Jones, Eugenia; Croteau, Marie-Noële; Luoma, Samuel N; Rainbow, Philip S

    2014-04-01

    Pollutants affecting species at the population level generate ecological instability in natural systems. The success of early life stages, such as those of aquatic invertebrates, is highly affected by adverse environmental conditions. Silver released into the environment from emerging nanotechnology represents such a threat. Sediments are sinks for numerous pollutants, which aggregate and/or associate with depositing suspended particles. Deposit feeder such as the annelid Platynereis dumerilii, which has a large associated literature on its development, is an excellent model organism for exposure studies in coastal environments. We exposed eggs, larvae, juveniles and adults of P. dumerilii to various concentrations of citrate (cit-Ag NPs) or humic acid (HA-Ag NPs) capped silver nanoparticles (Ag NPs) as well to dissolved Ag (added as AgNO3). We showed that mortality and abnormal development rate increased with younger life stages. While adults and juvenile were the most tolerant life stages, fertilized eggs were highly sensitive to AgNO3, cit-Ag NPs and HA-Ag NPs. Exposures to HA-Ag NPs triggered the highest cute toxicity responses in P. dumerilii and in most cases both Ag NPs were more toxic than AgNO3. Uptake rate of HA-Ag NPs in adult worms was also higher than from other Ag forms, consistent with toxicity to other life stages. The early stages of the life cycle of marine coastal organisms are more affected by Ag NPs than the juvenile or adult life stages, indicating that exposure experiments at the larval level contribute to realistic eco-toxicological studies in aquatic environments. PMID:24514586

  15. Toxicity and accumulation of silver nanoparticles during development of the marine polychaete Platynereis dumerilii

    USGS Publications Warehouse

    García-Alonso, Javier; Rodriguez-Sanchez, Neus; Misra, Superb K.; Valsami-Jones, Eugenia; Croteau, Marie-Noële; Luoma, Samuel N.; Rainbow, Philip S.

    2014-01-01

    Pollutants affecting species at the population level generate ecological instability in natural systems. The success of early life stages, such as those of aquatic invertebrates, is highly affected by adverse environmental conditions. Silver released into the environment from emerging nanotechnology represents such a threat. Sediments are sinks for numerous pollutants, which aggregate and/or associate with depositing suspended particles. Deposit feeder such as the annelid Platynereis dumerilii, which has a large associated literature on its development, is an excellent model organism for exposure studies in coastal environments. We exposed eggs, larvae, juveniles and adults of P. dumerilii to various concentrations of citrate (cit-Ag NPs) or humic acid (HA-Ag NPs) capped silver nanoparticles (Ag NPs) as well to dissolved Ag (added as AgNO3). We showed that mortality and abnormal development rate increased with younger life stages. While adults and juvenile were the most tolerant life stages, fertilized eggs were highly sensitive to AgNO3, cit-Ag NPs and HA-Ag NPs. Exposures to HA-Ag NPs triggered the highest cute toxicity responses in P. dumerilii and in most cases both Ag NPs were more toxic than AgNO3. Uptake rate of HA-Ag NPs in adult worms was also higher than from other Ag forms, consistent with toxicity to other life stages. The early stages of the life cycle of marine coastal organisms are more affected by Ag NPs than the juvenile or adult life stages, indicating that exposure experiments at the larval level contribute to realistic eco-toxicological studies in aquatic environments.

  16. Harmonization of standard toxicity test methods used in North America

    SciTech Connect

    Ingersoll, C.G.; Dwyer, F.J.; Ankley, G.T.

    1995-12-31

    Over the past two years, Environment Canada (EC) and the US Environmental Protection Agency (EPA) have developed standard methods for conducting toxicity and bioaccumulation tests with freshwater, estuarine, and marine sediments. Existing ASTM methods were used as a basis to harmonize these methods for conducting testing with either field-collected or laboratory-spiked sediments. For freshwater toxicity tests, methods are described by EC and EPA for the amphipod Hyalella azteca and the midges Chironomus tentans and C. riparius. Endpoints include 10- to 14-d survival of growth. Methods are also described by EPA for conducting 28-d bioaccumulation tests with the oligochaete Lumbriculus variegatus. For estuarine and marine toxicity tests, methods are described for several amphipods (i.e., Rhepoxynius abronius, Ampelisca abdita, Eohaustorius estuarius, Leptocheirus plumulosus). Endpoints include 10-d survival and reburial. EC is also developing methods for conducting toxicity tests with Atlantic, Pacific, and Arctic Canadian species of polychaetes. Methods are described by EPA for conducting 28-d bioaccumulation tests with a variety of mollusks (i.e., Macoma spp.) and polychaetes (i.e., Nereis spp.). Slight inconsistencies in methods between freshwater and estuarine/marine testing or between EC and EPA testing include: (1) static vs. flow-through conditions, (2) sieving of sediment, (3) types and quantity of food, (4) age of test organisms, or (4) duration of the test and required endpoints. Additional research is in progress to: (1) develop chronic toxicity tests with amphipods and midges measuring survival, growth, or reproduction, (2) develop whole-sediment toxicity identification evaluation (TIE) procedures, (3) refine sediment spiking procedures, and (4) field-validate laboratory tests.

  17. Disposition of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in two Norwegian epibenthic marine food webs.

    PubMed

    Ruus, Anders; Berge, John Arthur; Bergstad, Odd Aksel; Knutsen, Jan Atle; Hylland, Ketil

    2006-03-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are a group of halogenated hydrocarbons, comprising 210 different, theoretically possible congeners. They are relatively hydrophobic and persistent to biodegradation, thereby rendering them subject to bioaccumulation. This study was conducted in Frierfjord and Eidangerfjord in the Grenland fjord system, Norway, heavily polluted by PCDD/PCDF discharges from the 16,600,859 magnesium production at Herøya from 1951 to 2001. Pooled samples of surface-sediments and the following organisms were collected for the Frierfjord and Eidangerfjord study areas: common shrimp (Crangon crangon), polychaetes (mainly Nereis diversicolor), shore crab (Carcinus maenas), cod (Gadus morhua), flounder (Platichthys flesus), trout (Salmo trutta), herring (Clupea harengus), benthic amphipods and zooplankton. Concentrations of 2,3,7,8-PCDD/Fs were quantified in pooled samples for all species. The relative abundances of stable isotopes of nitrogen (delta(15)N) were evaluated in the organisms as a measure of chemically-derived trophic level. Contrary to earlier studies on other persistent organochlorines, it was found that the concentrations of PCDD/Fs declined with increasing trophic level. Principal Component Analysis (PCA) also showed differences between species in the pattern of PCDD/Fs. Higher chlorinated congeners constituted lower percentages of the PCDD/F-concentrations higher in the food chain as compared to lower trophic levels. In general, congener patterns did not differ between fjords. Infauna (polychaetes) and zooplankton had congener patterns most similar to the pollution source. The results indicate lower accumulation of higher chlorinated congeners in species at higher trophic levels (fish), presumably due to low membrane permeability (high molecular size) and possibly slow transport through intestinal aqueous phases because of low aqueous solubility. PMID:16169571

  18. Bioavailability of a natural lead-contaminated invertebrate diet to zebrafish.

    PubMed

    Boyle, David; Amlund, Heidi; Lundebye, Anne-Katrine; Hogstrand, Christer; Bury, Nic R

    2010-03-01

    Dietary metals are increasingly recognized as key determinants of total metal burdens in fish, yet their ecotoxicological significance remains unclear. In this study, a pairwise experimental design was used to assess reproductive performance of zebrafish (Danio rerio) fed diets supplemented with a natural Pb-enriched polychaete, Nereis diversicolor. Zebrafish were fed 1% flake food (dry wt diet/wet wt fish/d), 1% brine shrimp, and 1% N. diversicolor collected from either Gannel estuary, Cornwall, United Kingdom (UK), an estuary with legacy Pb contamination, or Blackwater estuary, Essex, UK, a reference site with low background metal concentrations, for 63 d. Mean daily dietary doses of Pb were 0.417 and 0.1 mg/kg/d (dry wt feed:wet wt fish) for fish fed N. diversicolor from Gannel and Blackwater estuaries, respectively. With the exception of Ag, which was higher for fish fed N. diversicolor from Gannel estuary, there were no differences in daily dietary exposures to other metals (As, Cd, Cu, Fe, and Zn) between treatment groups. Fish fed Pb-enriched Gannel N. diversicolor exhibited no significant impairment to incidence of spawning, numbers of eggs per breeding pair or hatch rate of embryos compared with pre-exposure levels, when N. diversicolor was omitted from the dietary regimen. Nevertheless, metal analysis revealed significant increases in whole-body Pb burdens of male fish fed polychaetes from Gannel estuary, Ag in female fish fed Gannel worms, and Ag and Cd in male fish fed the Blackwater worms. These data demonstrate that Pb naturally incorporated in N. diversicolor is bioavailable to fish, and fish exhibit sex-dependent dietary metal accumulation patterns, but after 63 d of the experimental feeding regimen, reproductive performance was unaffected.

  19. Characterization of the putatively introduced red alga Acrochaetium secundatum (Acrochaetiales, Rhodophyta) growing epizoically on the pelage of southern sea otters (Enhydra lutris nereis)

    USGS Publications Warehouse

    Bentall, Gena B.; Rosen, Barry H.; Kunz, Jessica M.; Miller, Melissa A.; Saunders, Gary W.; LaRoche, Nicole L.

    2016-01-01

    Ecological associations between epibionts (organisms that live on the surface of another living organism) and vertebrates have been documented in both marine and terrestrial environments, and may be opportunistic, commensal, or symbiotic (Lewin et al. 1981, Holmes 1985, Allen et al. 1993, Bledsoe et al. 2006, Pfaller et al. 2008, Suutari et al. 2010). Although epibiont proliferation is frequently reported on slow-moving, sparsely haired organisms such as manatees and sloths, reports from densely furred, highly mobile mammals are much less common. There are reports of epizoic algae for several species of pinnipeds (Kenyon and Rice 1959, Scheffer 1962, Baldridge 1977, Allen et al. 1993), which rely to varying degrees on both pelage and blubber for thermoregulation, but the phenomenon has not been widely described. Scheffer (1962) noted that red algae was fairly common on the pelage of northern fur seals (Callorhinus ursinus), pinnipeds for which fur likely makes a comparatively high contribution to thermoregulation (Donohue et al. 2000). For species with pelage that plays a critical role of thermal insulation, it seems implausible that an epibiont would persist on healthy individuals that devote significant energy resources toward grooming and actively maintaining their coat. Biological characteristics of epibiont settlement and attachment, and physiological requirements of epizoic species play key roles in their successful colonization and potential host impacts. To investigate this relationship, we explore a novel discovery of an epizoic alga from southern sea otters, including describing algal development on sea otter hair and molecular identification of the algae.

  20. Nereididae (Annelida: Phyllodocida) of Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Glasby, Christopher J

    2015-01-01

    Nereididae is one of the most ubiquitous of polychaete families, yet knowledge of their diversity in the northern Great Barrier Reef is poor; few species have been previously reported from any of the atolls or islands including Lizard Island. In this study, the diversity of the family from Lizard Island and surrounding reefs is documented based on museum collections derived from surveys conducted mostly over the last seven years. The Lizard Island nereidid fauna was found to be represented by 14 genera and 38 species/species groups, including 11 putative new species. Twelve species are newly reported from Lizard Island; four of these are also first records for Australia. For each genus and species, diagnoses and/or taxonomic remarks are provided in addition to notes on their habitat on Lizard Island, and general distribution; the existence of tissue samples tied to vouchered museum specimens is indicated. Fluorescence photography is used to help distinguish closely similar species of Nereis and Platynereis. A key is provided to facilitate identification and encourage further taxonomic, molecular and ecological studies on the group. PMID:26624071

  1. Nereididae (Annelida: Phyllodocida) of Lizard Island, Great Barrier Reef, Australia.

    PubMed

    Glasby, Christopher J

    2015-09-18

    Nereididae is one of the most ubiquitous of polychaete families, yet knowledge of their diversity in the northern Great Barrier Reef is poor; few species have been previously reported from any of the atolls or islands including Lizard Island. In this study, the diversity of the family from Lizard Island and surrounding reefs is documented based on museum collections derived from surveys conducted mostly over the last seven years. The Lizard Island nereidid fauna was found to be represented by 14 genera and 38 species/species groups, including 11 putative new species. Twelve species are newly reported from Lizard Island; four of these are also first records for Australia. For each genus and species, diagnoses and/or taxonomic remarks are provided in addition to notes on their habitat on Lizard Island, and general distribution; the existence of tissue samples tied to vouchered museum specimens is indicated. Fluorescence photography is used to help distinguish closely similar species of Nereis and Platynereis. A key is provided to facilitate identification and encourage further taxonomic, molecular and ecological studies on the group.

  2. The use of Monte Carlo analysis for exposure assessment of an estuarine food web

    SciTech Connect

    Iannuzzi, T.J.; Shear, N.M.; Harrington, N.W.; Henning, M.H.

    1995-12-31

    Despite apparent agreement within the scientific community that probabilistic methods of analysis offer substantially more informative exposure predictions than those offered by the traditional point estimate approach, few risk assessments conducted or approved by state and federal regulatory agencies have used probabilistic methods. Among the likely deterrents to application of probabilistic methods to ecological risk assessment is the absence of ``standard`` data distributions that are considered applicable to most conditions for a given ecological receptor. Indeed, point estimates of ecological exposure factor values for a limited number of wildlife receptors have only recently been published. The Monte Carlo method of probabilistic modeling has received increasing support as a promising technique for characterizing uncertainty and variation in estimates of exposure to environmental contaminants. An evaluation of literature on the behavior, physiology, and ecology of estuarine organisms was conducted in order to identify those variables that most strongly influence uptake of xenobiotic chemicals from sediments, water and food sources. The ranges, central tendencies, and distributions of several key parameter values for polychaetes (Nereis sp.), mummichog (Fundulus heteroclitus), blue crab (Callinectes sapidus), and striped bass (Morone saxatilis) in east coast estuaries were identified. Understanding the variation in such factors, which include feeding rate, growth rate, feeding range, excretion rate, respiration rate, body weight, lipid content, food assimilation efficiency, and chemical assimilation efficiency, is critical to the understanding the mechanisms that control the uptake of xenobiotic chemicals in aquatic organisms, and to the ability to estimate bioaccumulation from chemical exposures in the aquatic environment.

  3. Comparing Polychaete Bioaccumulation and Passive Sampler Uptake to Assess the Effect of Sediment Resuspension on Contaminant Bioavailability

    EPA Science Inventory

    Increased bioavailability of polychlorinated biphenyls (PCBs) from resettled sediments following remedial dredging is suspected of contributing to elevated organism tissue concentrations at contaminated sites. However, little data exists to evaluate whether increases in bioavaila...

  4. Molecular evidence of undescribed Ceratonova sp. (Cnidaria: Myxosporea) in the freshwater polychaete, Manayunkia speciosa, from western Lake Erie

    USGS Publications Warehouse

    Malakauskas, David M.; Snipes, Robert Benjamin; Thompson, Ann M.; Schloesser, Donald W.

    2016-01-01

    We used PCR to screen pooled individuals of Manayunkia speciosa from western Lake Erie, Michigan, USA for myxosporean parasites. Amplicons from positive PCRs were sequenced and showed a Ceratonova species in an estimated 1.1% (95% CI = 0.46%, 1.8%) of M. speciosa individuals. We sequenced 18S, ITS1, 5.8S, ITS2 and most of the 28S rDNA regions of this Ceratonova sp., and part of the protein-coding EF2 gene. Phylogenetic analyses of ribosomal and EF2 sequences showed the Lake Erie Ceratonova sp. is most similar to, but genetically distinct from, Ceratonova shasta. Marked interspecific polymorphism in all genes examined, including the ITS barcoding genes, along with geographic location suggests this is an undescribed Ceratonova species. COI sequences showed M. speciosa individuals in Michigan and California are the same species. These findings represent a third parasite in the genus Ceratonovapotentially hosted by M. speciosa.

  5. Intense predation cannot always be detected experimentally: A case study of shorebird predation on nereid polychaetes in South Africa

    NASA Astrophysics Data System (ADS)

    Kalejta, B.

    The effect of predation by curlew sandpipers Calidris ferruginea L. and grey plovers Pluvialis squatarola (L.) on populations of nereid worms Ceratonereis keiskama (Day) and C. erythraeensis (Fauvel) was studied at the Berg River estuary, South Africa, by comparing observations of shorebird-foraging intensity with the results of a population study of two species of nereid worms within and outside bird exclosures. The study was carried out during the four-month period prior to northward migration of shorebirds. Population structure of the two nereid species differed considerably. Ceratonereis keiskama reproduced earlier than C. erythraeensis and only young individuals were present during the study. By contrast, old C. erythraeensis were available to the birds at the start of the experiment and young animals entered the population during the experiment. Despite selective predation on certain size classes of nereids by the birds, no significant changes in the population structure of either nereid were detected by the cage experiment. Numbers and biomass of both Ceratonereis spp. in paired controls and cages tracked each other and did not diverge as predicted. A consistent difference in the depth stratification of the two nereids may, however, have been due to predation pressure. Curlew sandpipers were calculated to remove 3112 nereids per m 2 during the three months, equivalent to 4.4. g (dry weight) per m 2. This represents 58% of the initial numbers and 77% of the initial biomass of nereids. Although predation on nereids by waders was exceptionally high at the Berg River estuary, any depletion in numbers or biomass of nereids caused by these predators was masked by the reproduction of the nereids. The fact that the predators' high energy requirements prior to northward migration coincide with the period of peak production of invertebrate prey makes the Berg River estuary an exceptionally favourable wintering area.

  6. Macrofaunal involvement in the sublittoral decay of kelp debris: the polychaete Platynereis dumerilii (Audouin and Milne-Edwards) (Annelida: Polychaeta)

    NASA Astrophysics Data System (ADS)

    Bedford, A. P.; Moore, P. G.

    1985-02-01

    Platynereis dumerilii is found in large numbers in parchment-like tubes attached to sublittoral accumulations of detached maroalgae (principally Laminaria saccharina) in Kames Bay, Isle of Cumbrae and Lochranza, Isle of Arran. Its rôle in weed decomposition has been examined by comparing its responses (behavioural choice, growth rates, absorption efficiencies of both carbon and protein, gut retention times and rate of faecal output) to fresh and rotting weed. Worms grew significantly on either diet, with older individuals gaining more weight than small individuals. Animals of a standard size (derived from measurements of maximum bite size) feeding on fresh weed, however, grew significantly faster than those feeding on rotting weed. The former had a significantly higher protein absorption efficiency which was linearly related to protein content of ingested weed. This was not so on rotting weed. Organic carbon absorption efficiencies did not differ significantly between the two groups, neither did gut retention times nor rates of faecal output. Given a choice, Platynereis chooses to build its tube, and to feed, on fresh kelp—a strategem which ensures both maximum scope for occupancy before fronds decay and a superabundance of preferred food. Platynereis feeds around its tube entrance, recropping small areas for 2-3 days, prior to switching to another area nearby. Ciliate population densities on Platynereis faeces are much lower than on either homogenized or intact weed, associated with their lower, nutritional value (at first). Platynereis bubes act to bind kelp fronds together stabilizing the faecal input to infaunal detritivores. Platynereis is an example of a detritivore which exploits the detrital substratum directly.

  7. Geographical patterns of dominant bivalves and a polychaete in Europe: no metapopulations in the marine coastal zone?

    NASA Astrophysics Data System (ADS)

    Hummel, Herman

    2003-01-01

    The genetic diversity, differentiation and performance of some dominant invertebrates in the marine coastal zone of Europe are reviewed in order to discuss the use of the metapopulation concept in the marine coastal realm. A consistently high genetic diversity of the species studied (mussels of the Mytilus edulis complex, Baltic clams Macoma balthica and lugworms A renicola marina), a low differentiation and an almost uniform ecophysiological performance (determined by growth, maximum length, level reserve constituents or stress resistance) all along the coast of Europe do not support the use of the metapopulation concept.

  8. Recolonization pattern of the polychaete Lanice conchilega on an intertidal sand flat following the severe winter of 1995/96

    NASA Astrophysics Data System (ADS)

    Strasser, Matthias; Pieloth, Ursula

    2001-08-01

    The recolonization process of Lanice conchilega was studied on an intertidal sand flat in the northern Wadden Sea after an intertidal population had been wiped out during the severe winter of 1995/96. After very low recruitment in the first two years, the population fully recovered in the third year after its destruction. By then, the distribution pattern closely resembled the pattern before the severe winter with >95% of all Lanice occurring below -0.5 m mean tidal level and dominance of the density categories 6-50 individuals (ind) m-2 and 51-200 ind m-2. Lanice larvae have been observed to attach preferentially on the tubes of adults. However, the high recruitment in the third year was also seen in areas devoid of adult Lanice, indicating that settlement facilitation by adults was of little importance for the recolonization process. Instead, we suggest that the observed recruitment pattern was a consequence of a large-scale decline in the metapopulation in the tidal basin and the onshore coastal subtidal which resulted in insufficient larval supply onto the tidal flats and low recruitment in the first two years following the severe winter.

  9. Geographical patterns of dominant bivalves and a polychaete in Europe: no metapopulations in the marine coastal zone?

    NASA Astrophysics Data System (ADS)

    Hummel, Herman

    2002-12-01

    The genetic diversity, differentiation and performance of some dominant invertebrates in the marine coastal zone of Europe are reviewed in order to discuss the use of the metapopulation concept in the marine coastal realm. A consistently high genetic diversity of the species studied (mussels of the Mytilus edulis complex, Baltic clams Macoma balthica and lugworms Arenicola marina), a low differentiation and an almost uniform ecophysiological performance (determined by growth, maximum length, level reserve constituents or stress resistance) all along the coast of Europe do not support the use of the metapopulation concept.

  10. Development and Evaluation of Polychaete Reverse Samplers for Marine Phase II Whole Sediment Toxicitiy Identification Evaluations (TIE)

    EPA Science Inventory

    Marine and estuarine sediments accumulate contaminants and act as a sink for a wide range of toxic chemicals. As a result, the sediments themselves can become a source of contamination. At sufficient levels, contaminated sediments can cause benthic impairments and toxicity to m...

  11. [Influences of petroleum hydrocarbons on accumulation of cadmium and induction of metallothionein in the polychaete Perinereis aibuhitensis].

    PubMed

    Zhang, Qian-Ru; Mu, Wen-Yan; Zhang, Jing-Yi; Liu, Li; Wei, Shu-He

    2014-09-01

    Ragworm (Polychaeta) is an ecologically important species in intertidal mudflats and estuaries and is recognized as a sentinel species for environmental monitoring. In the intertidal belt of China, the ragworm Perinereis aibuhitensis is frequently exposed to various toxicants including cadmium (Cd) and petroleum hydrocarbons (PHCs). The present study investigated the influence of PHCs on accumulation of Cd and the induction of metallothionein (MT) in P. aibuhitensis by means of chronic microcosm experiment in which the ragworms were exposed to Cd or combinations of Cd and PHCs. The accumulation of Cd in P. aibuhitensis increased significantly with the Cd exposure concentration when exposed to Cd alone. Further, the bioconcentration factors (BCFs) for Cd in P. aibuhitensis increased with the duration of exposure. The addition of PHCs in Cd exposure solutions significantly increased the accumulation of Cd in P. aibuhitensis, compared with the control. Exposure to Cd induced the expression of MT, and the expression increased with the concen- tration up to 180 mg · kg(-1) DM Cd at which point the level of induction did not increase. PHCs without Cd did not significantly induce MT in P. aibuhitensis, but the addition of PHCs with Cd did influence the induction of MT compared to Cd without PHCs. Results indicated that PHCs could modulate the expression of MT during co-exposure with Cd. The potential substances other than metals influencing the interpretation of MT expression in wild P. aibuhitensis must be recognized when MT is used as a monitoring index.

  12. Maternal Inheritance of Twist and Analysis of MAPK Activation in Embryos of the Polychaete Annelid Platynereis dumerilii

    PubMed Central

    Pfeifer, Kathrin; Schaub, Christoph; Domsch, Katrin; Dorresteijn, Adriaan; Wolfstetter, Georg

    2014-01-01

    In this study, we aimed to identify molecular mechanisms involved in the specification of the 4d (mesentoblast) lineage in Platynereis dumerilii. We employ RT-PCR and in situ hybridization against the Platynereis dumerilii twist homolog (Pdu-twist) to reveal mesodermal specification within this lineage. We show that Pdu-twist mRNA is already maternally distributed. After fertilization, ooplasmatic segregation leads to relocation of Pdu-twist transcripts into the somatoblast (2d) lineage and 4d, indicating that the maternal component of Pdu-twist might be an important prerequisite for further mesoderm specification but does not represent a defining characteristic of the mesentoblast. However, after the primordial germ cells have separated from the 4d lineage, zygotic transcription of Pdu-twist is exclusively observed in the myogenic progenitors, suggesting that mesodermal specification occurs after the 4d stage. Previous studies on spiral cleaving embryos revealed a spatio-temporal correlation between the 4d lineage and the activity of an embryonic organizer that is capable to induce the developmental fates of certain micromeres. This has raised the question if specification of the 4d lineage could be connected to the organizer activity. Therefore, we aimed to reveal the existence of such a proposed conserved organizer in Platynereis employing antibody staining against dpERK. In contrast to former observations in other spiralian embryos, activation of MAPK signaling during 2d and 4d formation cannot be detected which questions the existence of a conserved connection between organizer function and specification of the 4d lineage. However, our experiments unveil robust MAPK activation in the prospective nephroblasts as well as in the macromeres and some micromeres at the blastopore in gastrulating embryos. Inhibition of MAPK activation leads to larvae with a shortened body axis, defects in trunk muscle spreading and improper nervous system condensation, indicating a critical function for MAPK signaling for the reorganization of embryonic tissues during the gastrulation process. PMID:24792484

  13. Molecular evidence of undescribed Ceratonova sp. (Cnidaria: Myxosporea) in the freshwater polychaete, Manayunkia speciosa, from western Lake Erie.

    PubMed

    Malakauskas, David M; Snipes, R Benjamin; Thompson, Ann M; Schloesser, Donald W

    2016-06-01

    We used PCR to screen pooled individuals of Manayunkia speciosa from western Lake Erie, Michigan, USA for myxosporean parasites. Amplicons from positive PCRs were sequenced and showed a Ceratonova species in an estimated 1.1% (95% CI=0.46%, 1.8%) of M. speciosa individuals. We sequenced 18S, ITS1, 5.8S, ITS2 and most of the 28S rDNA regions of this Ceratonova sp., and part of the protein-coding EF2 gene. Phylogenetic analyses of ribosomal and EF2 sequences showed the Lake Erie Ceratonova sp. is most similar to, but genetically distinct from, Ceratonova shasta. Marked interspecific polymorphism in all genes examined, including the ITS barcoding genes, along with geographic location suggests this is an undescribed Ceratonova species. COI sequences showed M. speciosa individuals in Michigan and California are the same species. These findings represent a third parasite in the genus Ceratonova potentially hosted by M. speciosa. PMID:27150245

  14. The combined and separate effects of hypoxia and cadmium exposure on the energetics of an opportunistic polychaete. I. growth

    SciTech Connect

    Forbes, R.L.; Forbes, V.E. )

    1990-01-09

    As part of a larger program studying the influence of environmental hypoxia and cadmium toxicity on benthic organisms, this study investigates the effects of hypoxia, food concentration, and body size on the growth rates of individual Capitella species I. Reduction of environmental pO or food level decreased the growth rates of both large (> 1.5 m[sup 3]; > 1.6 mg WW) and small (< 1.0 mm[sup 3]; < 1.1 mb WW) worms, but the effects were complex and interactions with body size were important. At high food concentrations a reduction in pO[sub 2] from 130 mmHg to 25mmHg decreased growth rates of worms by up to 30%/d. Growth rates of large worms decreased in response to reductions in either pO[sub 2] or food level. Growth of small worms decreased only in response to reductions in pO[sub 2]. Reductions in either food concentration of pO[sub 2] alone decreased the growth of large worms to the same extent as a concommitant decrease in both. When worms were fed 100% natural sediment, a reduction in pO[sub 2] from 38 mmHg to 21 mmHg decreased the growth rates of large worms from 2%/d to 25%/d. The growth of small individuals was unaffected. We predict that under conditions of near-bottom hypoxia or food limitation, populations of Capitella sp. I will experience size-dependent growth with large, reproductively mature animals experiencing the greatest decline in growth rates.

  15. Long-term effects of warming and ocean acidification are modified by seasonal variation in species responses and environmental conditions.

    PubMed

    Godbold, Jasmin A; Solan, Martin

    2013-01-01

    Warming of sea surface temperatures and alteration of ocean chemistry associated with anthropogenic increases in atmospheric carbon dioxide will have profound consequences for a broad range of species, but the potential for seasonal variation to modify species and ecosystem responses to these stressors has received little attention. Here, using the longest experiment to date (542 days), we investigate how the interactive effects of warming and ocean acidification affect the growth, behaviour and associated levels of ecosystem functioning (nutrient release) for a functionally important non-calcifying intertidal polychaete (Alitta virens) under seasonally changing conditions. We find that the effects of warming, ocean acidification and their interactions are not detectable in the short term, but manifest over time through changes in growth, bioturbation and bioirrigation behaviour that, in turn, affect nutrient generation. These changes are intimately linked to species responses to seasonal variations in environmental conditions (temperature and photoperiod) that, depending upon timing, can either exacerbate or buffer the long-term directional effects of climatic forcing. Taken together, our observations caution against over emphasizing the conclusions from short-term experiments and highlight the necessity to consider the temporal expression of complex system dynamics established over appropriate timescales when forecasting the likely ecological consequences of climatic forcing.

  16. Food sources of macro-invertebrates in an important mangrove ecosystem of Vietnam determined by dual stable isotope signatures

    NASA Astrophysics Data System (ADS)

    Tue, Nguyen Tai; Hamaoka, Hideki; Sogabe, Atsushi; Quy, Tran Dang; Nhuan, Mai Trong; Omori, Koji

    2012-08-01

    Dual stable isotope signatures (δ13C and δ15N) were applied to determine the contribution of mangrove materials and other organic carbon sources to the invertebrate community in an ecologically important mangrove ecosystem of Vietnam. We have analyzed 181 specimens of 30 invertebrate species and found δ13C and δ15N ranging from - 14.5 to - 26.8‰ and from 1.3 to 12.1‰, respectively. From taxa measured for stable isotopes, polychaete, gastropods, bivalves, and grapsid crabs living in mangrove forest showed relative low δ13C values, while fiddler crabs inhabiting in the land-water ecotone showed the highest δ13C values. The δ13C showed that just a few mangrove inhabitants directly relied on the mangrove materials. The wide ranges of δ13C and δ15N signatures indicated that the invertebrates utilized heterogeneous diets, comprising benthic microalgae, marine phytoplankton, particulate organic matter, sediment organic matter, mangrove detritus, and meiofauna and rotten animal tissues as the supplemental nutrient food sources. Moreover, the significant correlation between δ13C values and body sizes of invertebrates showed that snails Littoraria melanostoma and Terebralia sulcata, bivalve Glauconome virens, and portunid crab Scylla serrata exhibited ontogenetic shifts in diets. The present study showed that adjacent habitats such as tidal flat and mangrove creeks seem to contribute an important microalgal food resource for invertebrates and highlighted the need for conservations of mangrove forests and the adjacent habitats.

  17. Long-term effects of warming and ocean acidification are modified by seasonal variation in species responses and environmental conditions

    PubMed Central

    Godbold, Jasmin A.; Solan, Martin

    2013-01-01

    Warming of sea surface temperatures and alteration of ocean chemistry associated with anthropogenic increases in atmospheric carbon dioxide will have profound consequences for a broad range of species, but the potential for seasonal variation to modify species and ecosystem responses to these stressors has received little attention. Here, using the longest experiment to date (542 days), we investigate how the interactive effects of warming and ocean acidification affect the growth, behaviour and associated levels of ecosystem functioning (nutrient release) for a functionally important non-calcifying intertidal polychaete (Alitta virens) under seasonally changing conditions. We find that the effects of warming, ocean acidification and their interactions are not detectable in the short term, but manifest over time through changes in growth, bioturbation and bioirrigation behaviour that, in turn, affect nutrient generation. These changes are intimately linked to species responses to seasonal variations in environmental conditions (temperature and photoperiod) that, depending upon timing, can either exacerbate or buffer the long-term directional effects of climatic forcing. Taken together, our observations caution against over emphasizing the conclusions from short-term experiments and highlight the necessity to consider the temporal expression of complex system dynamics established over appropriate timescales when forecasting the likely ecological consequences of climatic forcing. PMID:23980249

  18. 75 FR 11171 - Notice of Filing of Several Pesticide Petitions for Residues of Pesticide Chemicals in or on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-10

    ... establish an exemption from the requirement of a tolerance for residues of the fungicide, Trichoderma virens... because, as proposed, the use of Trichoderma virens strain G-41 would not result in residues that are...

  19. Is porewater an important route of metals to macrobenthic organisms? Example of an estuarine field study

    SciTech Connect

    Srinetr, V.; Baeyens, W.; Ysebaert, T.; Meire, P.

    1995-12-31

    Porewater is recently hypothesized as a direct and important route of metal exposure to benthic organisms. However, only a few research studies clearly indicate its usefulness in monitoring and assessment of metal pollution. This study aims to answer whether porewater is really a significant route of metals to macrobenthic organisms in a natural sediment environment. Therefore, seven intertidal locations along the salinity gradient of the Schelde estuary (Belgium-The Netherlands) were investigated during a one year period (1993--1994). Metal analysis was performed on monthly samples of dominant macrobenthic species including the bivalves Macoma balthica, Scrobicularia plana, Cerastodema edule and Mya arenaria, the amphipod Corophium volutator and the polychaete Nereis diversicolor. Metal analysis includes manganese, chromium, nickel, copper, zinc, arsenic, selenium, cadmium and lead. The results show temporal and spatial variation of metals in both macrobenthic organisms and porewater. Levels of some metals in porewater, for example cadmium, lead, and copper are higher in winter months than in summer months in coherence with higher levels found in some benthic species. For some benthic species, metal contents were directly related to metal concentrations in porewater. However, no firm conclusion can be drawn that porewater is the only main source of bioavailable metals to benthic organisms and all metal species in porewater are bioavailable. In order to understand metal bioavailability in the sediment environment, a combination of information from a multidisciplinary approach (geochemistry, benthic ecology and toxicology) is needed. In fact, this study fits within the framework of a Triad-approach, conducted on sediments of the Schelde estuary.

  20. Effects of repeated field applications of two formulations of Bacillus thuringiensis var. israelensis on non-target saltmarsh invertebrates in Atlantic coastal wetlands.

    PubMed

    Caquet, Thierry; Roucaute, Marc; Le Goff, Pierre; Lagadic, Laurent

    2011-07-01

    Bacillus thuringiensis var. israelensis (Bti) is commonly used for selective control of larval populations of mosquitoes in coastal wetlands. A two year-study was implemented to investigate whether repeated treatments with Bti applied either as a liquid (VectoBac® 12AS) or a water-dispersible granule (VectoBac® WG) formulation may affect the abundance and diversity of non-target aquatic invertebrates in saltmarsh pools. Taxonomic composition of the invertebrate communities was typical of brackishwater intermittent ecosystems, with a dominance of annelids, crustaceans and nematocerans. Conditions were contrasted between the two years of the survey, both in terms of annual cumulative rainfall and rainfall distribution throughout the year. As a consequence, the hydroperiod and some other environmental characteristics associated with pool drying played a major role in the dynamics of the invertebrate community. In summer 2006, pool drying reduced the abundance of the polychaete worm Nereis diversicolor, of the amphipod crustacean Corophium volutator and of chironomid larvae. These taxa were able to recolonize rapidly the pools after flooding in September 2006. In 2007, rainfall was more regularly distributed across the year, and the pools did not get dry. Hydrozoans, Chironomini and Orthocladiinae larvae, and oligochaetes were more abundant in treated than in control pools, especially in VectoBac® WG-treated pools. No adverse effects of the treatments were shown on the abundance of N. diversicolor, C. volutator and midge larvae, suggesting that the availability of these food sources for birds was not negatively affected by Bti applications. It is concluded that, as currently performed in Western France coastal wetlands, land-based treatments of saltmarsh pools for larval mosquito control with Bti, used either as VectoBac® 12AS or VectoBac® WG, did not adversely impact non-target aquatic invertebrate communities. PMID:21592573

  1. Effects of repeated field applications of two formulations of Bacillus thuringiensis var. israelensis on non-target saltmarsh invertebrates in Atlantic coastal wetlands.

    PubMed

    Caquet, Thierry; Roucaute, Marc; Le Goff, Pierre; Lagadic, Laurent

    2011-07-01

    Bacillus thuringiensis var. israelensis (Bti) is commonly used for selective control of larval populations of mosquitoes in coastal wetlands. A two year-study was implemented to investigate whether repeated treatments with Bti applied either as a liquid (VectoBac® 12AS) or a water-dispersible granule (VectoBac® WG) formulation may affect the abundance and diversity of non-target aquatic invertebrates in saltmarsh pools. Taxonomic composition of the invertebrate communities was typical of brackishwater intermittent ecosystems, with a dominance of annelids, crustaceans and nematocerans. Conditions were contrasted between the two years of the survey, both in terms of annual cumulative rainfall and rainfall distribution throughout the year. As a consequence, the hydroperiod and some other environmental characteristics associated with pool drying played a major role in the dynamics of the invertebrate community. In summer 2006, pool drying reduced the abundance of the polychaete worm Nereis diversicolor, of the amphipod crustacean Corophium volutator and of chironomid larvae. These taxa were able to recolonize rapidly the pools after flooding in September 2006. In 2007, rainfall was more regularly distributed across the year, and the pools did not get dry. Hydrozoans, Chironomini and Orthocladiinae larvae, and oligochaetes were more abundant in treated than in control pools, especially in VectoBac® WG-treated pools. No adverse effects of the treatments were shown on the abundance of N. diversicolor, C. volutator and midge larvae, suggesting that the availability of these food sources for birds was not negatively affected by Bti applications. It is concluded that, as currently performed in Western France coastal wetlands, land-based treatments of saltmarsh pools for larval mosquito control with Bti, used either as VectoBac® 12AS or VectoBac® WG, did not adversely impact non-target aquatic invertebrate communities.

  2. Distribution and abundance of freshwater polychaetes, Manayunkia speciosa (Polychaeta), in the Great Lakes with a 70-year case history for western Lake Erie

    USGS Publications Warehouse

    Schloesser, Don W.

    2013-01-01

    Manayunkia speciosa has been a taxonomic curiosity for 150 years with little interest until 1977 when it was identified as an intermediate host of a fish parasite (Ceratomyxa shasta) responsible for fish mortalities (e.g., chinook salmon). Manayunkia was first reported in the Great Lakes in 1929. Since its discovery, the taxon has been reported in 50% (20 of 40 studies) of benthos studies published between 1960 and 2007. When found, Manayunkia comprised 2) and Georgian Bay (1790/m2) than in five other areas (mean = 60 to 553/m2) of the lakes. A 70-year history of Manayunkia in western Lake Erie indicates it was not found in 1930, was most abundant in 1961 (mean = 8039, maximum = 67,748/m2), and decreased in successive periods of 1982 (3529, 49,639/m2), 1993 (1876, 25,332/m2), and 2003 (79, 2583/m2). It occurred at 48% of stations in 1961, 58% in 1982, 52% in 1993, and 6% of stations in 2003. In all years, Manayunkia was distributed primarily near the mouth of the Detroit River. Causes for declines in distribution and abundance are unknown, but may be related to pollution-abatement programs that began in the 1970s, and invasion of dreissenid mussels in the late-1980s which contributed to de-eutrophication of western Lake Erie. At present, importance of the long-term decline of Manayunkia in Lake Erie is unknown.

  3. Ribosomal DNA identification of Nosema/Vairimorpha in freshwater polychaete, Manayunkia speciosa, from Oregon/California and the Laurentian Great Lakes

    USGS Publications Warehouse

    Malakauskas, David M.; Altman, Emory C.; Malakauskas, Sarah J.; Thiem, Suzanne M.; Schloesser, Donald W.

    2015-01-01

    We examined Manayunkia speciosa individuals from the Klamath River, Oregon/California and Lake Erie, Michigan, USA for the presence of Microsporidia. We identified microsporidian spores and sequenced their SSU, ITS, and part of the LSU rDNA. Phylogenetic analysis of SSU rDNA indicated spores from both populations belonged to the Nosema/Vairimorpha clade. PCR showed an infection prevalence in Lake Erie M. speciosa of 0.6% (95% CI = 0.5%, 0.7%). This represents the first known example of molecularly characterized Nosema/Vairimorpha isolates infecting a non-arthropod host.

  4. Effects of development mode, contaminated sediments, and maternal characteristics on growth and reproduction in the polychaetes Streblospio benedicti (Spionidae) and Capitella sp. I (Capitellidae)

    SciTech Connect

    Bridges, T.S.

    1992-01-01

    Experiments were conducted to examine the effects of contaminated sediments (sewage, blue-green algae and hydrocarbons) and maternal characteristics on reproduction, and offspring success in S. benedicti (lecithotrophic) and Capitella sp. I. For S. benedicti, contaminated sediments had a negative effect on growth and age and size at first reproduction. Per brood fecundity was positively related to female size and negatively related to female age. Treatments did not have an effect on reproductive output. Per offspring C and N investment increased with female age. This increase in per offspring investment resulted in enhanced survivorship and juvenile growth in offspring of older females. For Capitella sp. I, growth was increased, age at first reproduction was accelerated, and per brood fecundity was 3--4 [times] higher in the algae and sewage treatments. Treatments did not have an effect on reproductive output. Fecundity was positively related to female size. Per brood and per offspring C and N investment decreased with female age, but not in all treatments. The C:N ratio of offspring increased with female age. Offspring from mothers in the sewage treatment were larger two weeks after release. Offspring in size two weeks after release decreased with female age in the sewage treatment. Differences in the response of S. benedicti and Capitella sp. I to contaminated sediments may be due to differences in feeding behavior, digestive physiology, nutritional requirements and their sensitivity to hydrocarbons, metals and low oxygen concentrations. Differences in the effect of female age between the two species appear related to development and ecological differences in the two species.

  5. Molecular identification key based on PCR/RFLP for three polychaete sibling species of the genus Marenzelleria, and the species' current distribution in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Blank, M.; Laine, A. O.; Jürss, K.; Bastrop, R.

    2008-06-01

    Studies of Marenzelleria species were often hampered by identification uncertainties when using morphological characters only. A newly developed PCR/RFLP protocol allows a more efficient discrimination of the three species Marenzelleria viridis, Marenzelleria neglecta and Marenzelleria arctia currently known for the Baltic Sea. The protocol is based on PCR amplification of two mitochondrial DNA gene segments (16S, COI) followed by digestion with restriction enzymes. As it is faster and cheaper than PCR/sequencing protocols used so far, the protocol is recommended for large-scale analyses. The markers allow an undoubted determination of species irrespective of life stage or condition of the worms in the samples. The protocol was validated on about 950 specimens sampled at more than 30 sites of the Baltic and the North Sea, and on specimens from populations of the North American east coast. Besides this test we used mitochondrial DNA sequences (16S, COI, Cytb) and starch gel electrophoresis to further investigate the distribution of the three Marenzelleria species in the Baltic Sea. The results show that M. viridis (formerly genetic type I or M. cf. wireni) occurred in the Öresund area, in the south western as well as in the eastern Baltic Sea, where it is found sympatric with M. neglecta. Allozyme electrophoresis indicated an introduction by range expansion from the North Sea. The second species, M. arctia, was only found in the northern Baltic Sea, where it sometimes occurred sympatric with M. neglecta or M. viridis. For Baltic M. arctia, the most probable way of introduction is by ship ballast water from the European Arctic. There is an urgent need for a new genetic analysis of all Marenzelleria populations of the Baltic Sea to unravel the current distribution of the three species.

  6. Observations on the feeding mechanism, diet and digestive physiology of Histriobdella homari Van Beneden 1858: an aberrant polychaete symbiotic with North American and European lobsters.

    PubMed

    Jennings, J B; Gelder, S R

    1976-12-01

    1. The aberrant annelid Histriobdella homari (Polychaeta:Eunicida) lives in the branchial chambers of the marine lobsters Homarus americanus and H. vulgaris where it feeds on the rich microflora of bacteria, blue-green algae and related organisms which grow on the inner surface of the branchial chamber, the setae fringing the edges of the carapace, the gill filaments and, especially, the surfaces and setae of the epipodite plates between the gills. H. homari, therefore, is to be regarded as an epizoic microphagous cleaning symbiote of the lobsters. 2. The alimentary canal consists of mouth, buccal cavity, oesophagus, proventriculus, stomach, intestine and anus. The much-modified proboscis lies ventrally below the oesophagus and proventriculus, with its anterior portions protruding into the rear of the buccal cavity. 3. The proboscis consists of two fixed parallel mandibles, a transverse carrier which slides upon the mandibles and to which is attached, posteriorly, a median flexible dorsal rod and, anteriorly, four pairs of movable articulated maxillae, paired external and internal retractor muscles and various tensor, flexor and extensor muscles. 4. Contraction of the retractor muscles withdraws the carrier and maxillae posteriorly, causing bowing of the dorsal rod which is fixed at its posterior end. Relaxation of the muscles allows the rod to straighten and, thus, causes protraction of the carrier and protraction and lateral expansion of the maxillae. Contraction and relaxation of the relaxation of the retractor muscles are supplemented by appropriate changes in the other muscular components of the proboscis. 5. During feeding the serrated anterior ends of the mandibles are applied to the food, the maxillae are fully expanded and then dawn ventro-posteriorly toward the mid-line by contraction of the retractor muscles in the effective movement of the feeding mechanism. This draws the food organisms across the anterior ends of the mandibles, detaching them from the substratum and allowing their ingestion by ciliary action. The first pair of maxillae are also capable of independent action and can be used while the remainder of the proboscis apparatus is held in the protracted position. 6. Detached microorganisms are entangled in a sticky mucous secretion from the salivary glands; other salivary secretions provide a transport medium for the clumped particles and a third set contain C-esterases which initiate digestion. 7. Ingested food is held briefly in the proventriculus, then passed to the stomach where gland cells secrete A- and C-esterases which continue and extend the digestion initiated by the salivary C-esterases. 8. Some soluble products of gastric digestion are taken up by absorptive cells in the stomach wall and their digestion is completed intracellularly by enzymes which include beta-glucuronidase. Others pass into the intestine for absorption and completion of digestion by cells similar to the gastric absorptive cells but which lack beta-glucuronidase... PMID:1016663

  7. Biochemical and behavioural responses of the marine polychaete Hediste diversicolor to cadmium sulfide quantum dots (CdS QDs): waterborne and dietary exposure.

    PubMed

    Buffet, Pierre-Emmanuel; Poirier, Laurence; Zalouk-Vergnoux, Aurore; Lopes, Christelle; Amiard, Jean-Claude; Gaudin, Pierre; Risso-de Faverney, Christine; Guibbolini, Marielle; Gilliland, Douglas; Perrein-Ettajani, Hanane; Valsami-Jones, Eugenia; Mouneyrac, Catherine

    2014-04-01

    Cadmium sulfide (CdS) quantum dots are widely used in medical imaging. The aim of this study was to examine toxicity effects of CdS engineered nanoparticles (CdS NPs) compared to soluble Cd, on marine ragworms (Hediste diversicolor) exposed for 14 d to these contaminants (10 μg Cd L(-1)) in seawater or via their food (contaminated worm tissue). In our experimental media, Dynamic Light Scattering studies showed that the majority of CdS remained in the nanoscale (1-10 nm) with the exception of few aggregates (100-300 nm). Labile Cd fractions released from CdS NPs were estimated by diffusive gradient in thin films, showing that about 50% of CdS NPs remained in nanoparticulate form. Ragworms accumulated Cd in both soluble Cd and CdS NPs in waterborne exposures only. Greater significant changes of biochemical responses were observed in worms exposed to CdS NPs in seawater compared to contaminated food. Catalase and glutathione-S-transferase activities were the most sensitive biochemical biomarkers responding to both Cd treatments for waterborne exposure. Inductions of CAT were higher in diet-exposed worms to Cd as NPs vs soluble form suggesting a specific "nano" effect. Caspase activities increased in worms exposed to soluble Cd and Cd NPs for the two routes of exposure compared to controls. Defences, may be insufficient to prevent reactive oxygen species generation and the associated apoptosis. Behaviour of invertebrates inside sediment showed impairments of body movements in worms exposed to CdS NPs. This study points out oxidative processes as the main consequences of exposure to Cd based NPs in worms.

  8. The filtration activity of a serpulid polychaete population ( Ficopomatus enigmaticus (Fauvel) and its effects on water quality in a coastal marina

    NASA Astrophysics Data System (ADS)

    Davies, B. R.; Stuart, V.; de Villiers, M.

    1989-12-01

    An estimate of the total standing stock of Ficopomatus enigmaticus (Fauvel) in the Marina da Gama, Zandvlei, near Cape Town was made, and some aspects of the animals' filter-feeding behaviour investigated. Working on values of 5·23 g dry mass of worm (excluding tube) m -2 on the submerged aquatic plant Potamogeton pectinatus L., plus 84·9 g m -2 on the canal walls, the total standing stock of the serpulid was estimated at 2·88±2·24 t (1·4 t on Potamogeton; 1·48 t on canal walls). At the average particle concentrations of Marina water of 5·27 mg l -1, the clearnace rate of F. enigmaticus was 8·59 ml mg -1 worm h -1, resulting in an ingestion rate of 45·27 mg mg -1 worm h -1 of particles in the size range 2-16 μm. Clearance and ingestion rates both increased in direct proportion to food concentration. Using estimates of total standing stocks within the Marina, the F. enigmaticus population clears 2·47 × 10 7 l of water h -1 and consumes 1·3 × 10 8 mg of particles h -1 in the 2-16 μm size range. Thus, the entire volume of the Marina will be filtered in 26·1 h through the activities of this animal alone, illustrating its importance for the maintenance of water quality within this moderately polluted system.

  9. Expression of the Lhx genes apterous and lim1 in an errant polychaete: implications for bilaterian appendage evolution, neural development, and muscle diversification

    PubMed Central

    2013-01-01

    Background Arthropod and vertebrate appendages appear to have evolved via parallel co-option of a plesiomorphic gene regulatory network. Our previous work implies that annelids evolved unrelated appendage-forming mechanisms; we therefore found no support for homology of parapodia and arthropodia at the level of the whole appendage. We expand on that study here by asking whether expression of the LIM homeobox (Lhx) genes apterous and lim1 in the annelid Neanthes arenaceodentata supports homology of the dorsal branches as well as the proximodistal axes of parapodia and arthropodia. In addition, we explore whether the neural expression of apterous and lim1 in Neanthes supports the putative ancestral function of the Lhx gene family in regulating the differentiation and maintenance of neuronal subtypes. Results Both genes exhibit continuous expression in specific portions of the developing central nervous system, from hatching to at least the 13-chaetiger stage. For example, nerve cord expression occurs in segmentally iterated patterns consisting of diffuse sets of many lim1-positive cells and comparatively fewer, clustered pairs of apterous-positive cells. Additionally, continuous apterous expression is observed in presumed neurosecretory ganglia of the posterior brain, while lim1 is continuously expressed in stomatogastric ganglia of the anterior brain. apterous is also expressed in the jaw sacs, dorsal parapodial muscles, and a presumed pair of cephalic sensory organs, whereas lim1 is expressed in multiple pharyngeal ganglia, the segmental peripheral nervous system, neuropodial chaetal sac muscles, and parapodial ligules. Conclusions The early and persistent nervous system expression of apterous and lim1 in Neanthes juveniles supports conservation of Lhx function in bilaterian neural differentiation and maintenance. Our results also suggest that diversification of parapodial muscle precursors involves a complementary LIM code similar to those generating distinct neuronal identities in fly and mouse nerve cords. Expression of apterous and lim1 in discrete components of developing parapodia is intriguing but does not map to comparable expression of these genes in developing arthropod appendages. Thus, annelid and arthropod appendage development apparently evolved, in part, via distinct co-option of the neuronal regulatory architecture. These divergent patterns of apterous and lim1 activity seemingly reflect de novo origins of parapodia and arthropodia, although we discuss alternative hypotheses. PMID:23369627

  10. Effects of chronic metal exposure and sediment organic matter on digestive absorption efficiency of cadmium by the deposit-feeding polychaete Capitella species I

    SciTech Connect

    Selck, H.; Forbes, V.E. . Dept. of Life Sciences and Chemistry); Decho, A.W. . Dept. of Environmental Health Sciences)

    1999-06-01

    Organic matter such as humic acid and bacterial slime exopolymer are common in estuarine and coastal sediments, where they are ingested by animals that process particulate detritus. Both humic acid (HA; refractory) and exopolymer (EPS; easily digestible) bind metals and therefore might represent a source of particulate-bound metals to deposit-feeding organisms. This study examined how cadmium preexposure, gut passage time (GPT), and quality and quantity of the organic coating on sediment particles interact to determine cadmium absorption efficiency (Cd-AE) in Capitella sp. I. Pulse-chase experiments using [sup 109]Cd and [sup 51]Cr were used to determine Cd-AE in individual worms. Worms were given a pulse of carbon-cleaned, HA-coated or EPS-coated sediment particles. The third treatment was divided into three EPS concentrations (high, medium, and low). A 5-d preexposure to cadmium did not affect the egestion rates during either the preexposure period or the chase phase. Worms given a pulse of carbon-cleaned particles exhibited higher egestion rates during the chase phase than worms given a pulse of organic-coated particles, and no differences were seen in egestion rate between worms exposed to HA- and high-EPS-coated particles. Egestion rates decreased with increasing EPS concentration. The presence of refractory organic material decreased the absorption efficiency of cadmium from sediment relative to Cd-AE from carbon-cleaned sediment but not relative to Cd-AE from sediment coated with a high concentration of EPS. The Cd-AE increased linearly with increasing exopolymer coating on sediment particles. Overall, Cd-AE increased with increasing gut passage time in worms that were not preexposed, although Cd-AE from HA-coated particles was independent of gut passage time. Preexposure to cadmium reversed the relationship between gut passage time and cadmium absorption efficiency. Thus, the implications are that sedimentary organic matter and worm physiology might be especially important in controlling metal bioavailability in deposit-feeding organisms and should be considered in sediment quality approaches.

  11. The role of acid-volatile sulfide and interstitial water metal concentrations in determining bioavailability of cadmium and nickel from contaminated sediments to the marine polychaete Neanthes arenaceodentata

    SciTech Connect

    Pesch, C.E.; Hansen, D.J.; Boothman, W.S. . Environmental Research Lab.); Berry, W.J. ); Mahony, J.D. . Chemistry Dept.)

    1995-01-01

    This study investigated the influence of acid-volatile sulfide (AVS) and interstitial water (IW) metal concentrations on bioavailability and toxicity of Cd and Ni to an infaunal sediment-ingesting marine worm, Neanthes Arenaceodentata. Ten-d exposures were conducted with sediments, contaminated primarily with Cd and Ni, from Foundry Cove (Hudson River, NY), and with uncontaminated sediments spiked with Cd or Ni. Molar ratios of simultaneously extracted metal (SEM)/AVS ranged from < 0.02 to 44 for Cd-spiked, 0.02 to 241 for Ni-spiked, and <0.06 to 125 for Foundry Cove sediments. In all experiments, significant mortality was not observed when SEM/AVS ratios were <1.0 and interstitial water toxic units (IWTU) were <1.0. In the Cd and Ni-spiked experiments, when SEM/AVS ratios or IWTUs were >1.0, sediments were either lethal or worms did not burrow. Mortality of worms in Foundry Cove sediments was [le] 20%, and worms burrowed in all these sediments. However, IW contained <1.0 TU (Ni + Cd) in all Foundry Cove sediments except one (IWTU = 1.69). Metal concentrations in worms generally increased with increases in sediment metal concentration, SEM/AVS molar ratio, and IW metal concentration. The presence of metal in worms from sediments from SEM/AVS ratios <1.0 may be evidence of release of Cd or Ni from oxidized metal sulfide (a result of burrowing), uptake of metal from ingested sediment, or adsorption to body surfaces. These results support the hypothesis that when the concentration of AVS in sediments exceeds that of divalent metals sediments will not be acutely toxic. However, a greater number of sediments was correctly predicted to be nontoxic when interstitial water metal concentration of <1.0 TU was used.

  12. Biochemical and behavioural responses of the marine polychaete Hediste diversicolor to cadmium sulfide quantum dots (CdS QDs): waterborne and dietary exposure.

    PubMed

    Buffet, Pierre-Emmanuel; Poirier, Laurence; Zalouk-Vergnoux, Aurore; Lopes, Christelle; Amiard, Jean-Claude; Gaudin, Pierre; Risso-de Faverney, Christine; Guibbolini, Marielle; Gilliland, Douglas; Perrein-Ettajani, Hanane; Valsami-Jones, Eugenia; Mouneyrac, Catherine

    2014-04-01

    Cadmium sulfide (CdS) quantum dots are widely used in medical imaging. The aim of this study was to examine toxicity effects of CdS engineered nanoparticles (CdS NPs) compared to soluble Cd, on marine ragworms (Hediste diversicolor) exposed for 14 d to these contaminants (10 μg Cd L(-1)) in seawater or via their food (contaminated worm tissue). In our experimental media, Dynamic Light Scattering studies showed that the majority of CdS remained in the nanoscale (1-10 nm) with the exception of few aggregates (100-300 nm). Labile Cd fractions released from CdS NPs were estimated by diffusive gradient in thin films, showing that about 50% of CdS NPs remained in nanoparticulate form. Ragworms accumulated Cd in both soluble Cd and CdS NPs in waterborne exposures only. Greater significant changes of biochemical responses were observed in worms exposed to CdS NPs in seawater compared to contaminated food. Catalase and glutathione-S-transferase activities were the most sensitive biochemical biomarkers responding to both Cd treatments for waterborne exposure. Inductions of CAT were higher in diet-exposed worms to Cd as NPs vs soluble form suggesting a specific "nano" effect. Caspase activities increased in worms exposed to soluble Cd and Cd NPs for the two routes of exposure compared to controls. Defences, may be insufficient to prevent reactive oxygen species generation and the associated apoptosis. Behaviour of invertebrates inside sediment showed impairments of body movements in worms exposed to CdS NPs. This study points out oxidative processes as the main consequences of exposure to Cd based NPs in worms. PMID:24480429

  13. Purification, storage, and pathogenicity assay of rice false smut fungus under controlled environmental conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice false smut, caused by Ustilaginoidea virens, is serious disease that affects grain yield and quality. In the present study, a method to purify, store, and evaluate pathogenicity of U. virens under controlled environmental conditions was developed. Yellow chlamydospores were collected from fresh...

  14. 75 FR 30428 - Receipt of Applications for Permit

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-01

    ...), northern sea otters (Enhydra lutris kenyoni) and southern sea otters (Enhydra lutris nereis) may be... acquire, import, and export unlimited number of specimens of sea otters (Enhydra lutris), marine...

  15. An account of the taxonomy and distribution of Syllidae (Annelida, Polychaetes) in the eastern Mediterranean, with notes on the genus Prosphaerosyllis San Martín, 1984 in the Mediterranean

    PubMed Central

    Faulwetter, Sarah; Chatzigeorgiou, Georgios; Galil, Bella S.; Arvanitidis, Christos

    2011-01-01

    Abstract The syllid fauna of three locations in Crete and Israel (eastern Mediterranean Sea) was studied, yielding 82 syllid species, many of which were found for the first time in the respective areas: Seventeen species were recorded for the first time on the Israeli coasts and 20 in Greek waters. Perkinsyllis augeneri (Hartmann-Schröder, 1979) and Prosphaerosyllis chauseyensis Olivier et al., 2011 are new records for the Mediterranean Sea. Detailed information is given on the morphology, ecology and distribution of the species recorded for the first time in the studied areas. In addition, an update on the distribution of the genus Prosphaerosyllis San Martín, 1984 in the Mediterranean is given and an identification key to the Mediterranean species is provided. PMID:22207817

  16. Detection and characterisation of mutations responsible for allele-specific protein thermostabilities at the Mn-superoxide dismutase gene in the deep-sea hydrothermal vent polychaete Alvinella pompejana.

    PubMed

    Bruneaux, Matthieu; Mary, Jean; Verheye, Marie; Lecompte, Odile; Poch, Olivier; Jollivet, Didier; Tanguy, Arnaud

    2013-05-01

    Alvinella pompejana (Polychaeta, Alvinellidae) is one of the most thermotolerant marine eukaryotes known to date. It inhabits chimney walls of deep-sea hydrothermal vents along the East Pacific Rise (EPR) and is exposed to various challenging conditions (e.g. high temperature, hypoxia and the presence of sulphides, heavy metals and radiations), which increase the production of dangerous reactive oxygen species (ROS). Two different allelic forms of a manganese-superoxide dismutase involved in ROS detoxification, ApMnSOD1 and ApMnSOD2, and differing only by two substitutions (M110L and A138G) were identified in an A. pompejana cDNA library. RFLP screening of 60 individuals from different localities along the EPR showed that ApMnSOD2 was rare (2 %) and only found in the heterozygous state. Dynamic light scattering measurements and residual enzymatic activity experiments showed that the most frequent form (ApMnSOD1) was the most resistant to temperature. Their half-lives were similarly long at 65 °C (>110 min) but exhibited a twofold difference at 80 °C (20.8 vs 9.8 min). Those properties are likely to be explained by the occurrence of an additional sulphur-containing hydrogen bond involving the M110 residue and the effect of the A138 residue on the backbone entropy. Our results confirm the thermophily of A. pompejana and suggest that this locus is a good model to study how the extreme thermal heterogeneity of the vent conditions may help to maintain old rare variants in those populations.

  17. 50 CFR 648.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... affected states. Editorial Note: For Federal Register citations affecting § 648.2, see the List of CFR.... Sand worm—Neresis virens. Soft clam—Mya arenaria. Spider crabLibinia emarginata. Interest in an...

  18. 50 CFR 648.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... affecting § 648.2, see the List of CFR Sections Affected, which appears in the Finding Aids section of the.... Sand worm—Neresis virens. Soft clam—Mya arenaria. Spider crabLibinia emarginata. Interest in an...

  19. 50 CFR 648.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... affected states. Editorial Note: For Federal Register citations affecting § 648.2, see the List of CFR.... Sand worm—Neresis virens. Soft clam—Mya arenaria. Spider crabLibinia emarginata. Interest in an...

  20. 50 CFR 648.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... affecting § 648.2, see the List of CFR Sections Affected, which appears in the Finding Aids section of the.... Sand worm—Neresis virens. Soft clam—Mya arenaria. Spider crabLibinia emarginata. Interest in an...

  1. 77 FR 74500 - Proposed Habitat Conservation Plan/Natural Community Conservation Plan for Western Butte County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-14

    ... (Phrynosoma blainvillii), Western pond turtle (Actinemys marmorata), foothill yellow-legged frog (Rana boylii... blackbird (Agelaius tricolor), yellow-breasted chat (Icteria virens), bank swallow (Riparia riparia), Western burrowing owl (Athene ] cunicularia hypugea), western yellow-billed cuckoo (Coccyzus...

  2. SPORULATION AND SURVIVAL OF TOXOPLASMA GONDII OOCYSTS IN SEA WATER

    EPA Science Inventory

    Since 1992, we have been collaborating in studies on southern sea otters (Enhdyra lutris nereis) as part of a program to define factors which may be responsible for limiting the growth of the southern sea otter population. We previously demonstrated Toxoplasma gondii in sea otter...

  3. 76 FR 53453 - Environmental Impacts Statements; Notice of Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-26

    ..., Contact: Robert Hawkins 707-562-8699. EIS No. 20110275, Second Draft Supplement, FWS, CA, Southern Sea Otters (Enhydra lutris nereis) Translocation Program, Updated Information to the DSEIS 2005, San Nicolas..., Contact: Bruce Rogers 907- 822-7276. EIS No. 20110279, Final Supplement, MMS, AK, Chukchi Sea...

  4. Secretome of Trichoderma interacting with maize roots: role in induced systemic resistance.

    PubMed

    Lamdan, Netta-Li; Shalaby, Samer; Ziv, Tamar; Kenerley, Charles M; Horwitz, Benjamin A

    2015-04-01

    Trichoderma virens is a biocontrol agent used in agriculture to antagonize pathogens of crop plants. In addition to direct mycoparasitism of soil-borne fungal pathogens, T. virens interacts with roots. This interaction induces systemic resistance (ISR), which reduces disease in above-ground parts of the plant. In the molecular dialog between fungus and plant leading to ISR, proteins secreted by T. virens provide signals. Only a few such proteins have been characterized previously. To study the secretome, proteins were characterized from hydroponic culture systems with T. virens alone or with maize seedlings, and combined with a bioassay for ISR in maize leaves infected by the pathogen Cochliobolus heterostrophus. The secreted protein fraction from coculture of maize roots and T. virens (Tv+M) was found to have a higher ISR activity than from T. virens grown alone (Tv). A total of 280 fungal proteins were identified, 66 showing significant differences in abundance between the two conditions: 32 were higher in Tv+M and 34 were higher in Tv. Among the 34 found in higher abundance in Tv and negatively regulated by roots were 13 SSCPs (small, secreted, cysteine rich proteins), known to be important in the molecular dialog between plants and fungi. The role of four SSCPs in ISR was studied by gene knockout. All four knockout lines showed better ISR activity than WT without affecting colonization of maize roots. Furthermore, the secreted protein fraction from each of the mutant lines showed improved ISR activity compared with WT. These SSCPs, apparently, act as negative effectors reducing the defense levels in the plant and may be important for the fine tuning of ISR by Trichoderma. The down-regulation of SSCPs in interaction with plant roots implies a revision of the current model for the Trichoderma-plant symbiosis and its induction of resistance to pathogens.

  5. Secretome of Trichoderma Interacting With Maize Roots: Role in Induced Systemic Resistance*

    PubMed Central

    Lamdan, Netta-Li; Shalaby, Samer; Ziv, Tamar; Kenerley, Charles M.; Horwitz, Benjamin A.

    2015-01-01

    Trichoderma virens is a biocontrol agent used in agriculture to antagonize pathogens of crop plants. In addition to direct mycoparasitism of soil-borne fungal pathogens, T. virens interacts with roots. This interaction induces systemic resistance (ISR), which reduces disease in above-ground parts of the plant. In the molecular dialog between fungus and plant leading to ISR, proteins secreted by T. virens provide signals. Only a few such proteins have been characterized previously. To study the secretome, proteins were characterized from hydroponic culture systems with T. virens alone or with maize seedlings, and combined with a bioassay for ISR in maize leaves infected by the pathogen Cochliobolus heterostrophus. The secreted protein fraction from coculture of maize roots and T. virens (Tv+M) was found to have a higher ISR activity than from T. virens grown alone (Tv). A total of 280 fungal proteins were identified, 66 showing significant differences in abundance between the two conditions: 32 were higher in Tv+M and 34 were higher in Tv. Among the 34 found in higher abundance in Tv and negatively regulated by roots were 13 SSCPs (small, secreted, cysteine rich proteins), known to be important in the molecular dialog between plants and fungi. The role of four SSCPs in ISR was studied by gene knockout. All four knockout lines showed better ISR activity than WT without affecting colonization of maize roots. Furthermore, the secreted protein fraction from each of the mutant lines showed improved ISR activity compared with WT. These SSCPs, apparently, act as negative effectors reducing the defense levels in the plant and may be important for the fine tuning of ISR by Trichoderma. The down-regulation of SSCPs in interaction with plant roots implies a revision of the current model for the Trichoderma-plant symbiosis and its induction of resistance to pathogens. PMID:25681119

  6. 77 FR 4903 - Trichoderma

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-01

    ... Register of March 10, 2010 (75 FR 11171) (FRL-8810- 8), EPA issued a notice pursuant to section 408(d)(3... Trichoderma virens strain GL-21) (40 CFR 180.1100)--see the Federal Register of September 20, 1995 (60 FR 48657) (FRL-4974-1) and October 5, 1995 (60 FR 52248) (FRL-4974-1). 2. Trichoderma harzianum...

  7. Impacts of biocontrol products on Rhizoctonia disease of potato and soil microbial communities, and their persistence in soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four commercial biocontrol formulations (Bacillus subtilis GB03, Burkholderia ambifaria type Wisconsin isolate J82, Trichoderma virens Gl-21, and Trichoderma harzianum strain T-22), a chemical seed treatment (Topsin, mancozeb, and cymoxanil mixture, TMC), and a combination chemical/biological treatm...

  8. Biotransformation of Trichoderma spp. and their tolerance to aromatic amines, a major class of pollutants.

    PubMed

    Cocaign, Angélique; Bui, Linh-Chi; Silar, Philippe; Chan Ho Tong, Laetitia; Busi, Florent; Lamouri, Aazdine; Mougin, Christian; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Dairou, Julien

    2013-08-01

    Trichoderma spp. are cosmopolitan soil fungi that are highly resistant to many toxic compounds. Here, we show that Trichoderma virens and T. reesei are tolerant to aromatic amines (AA), a major class of pollutants including the highly toxic pesticide residue 3,4-dichloroaniline (3,4-DCA). In a previous study, we provided proof-of-concept remediation experiments in which another soil fungus, Podospora anserina, detoxifies 3,4-DCA through its arylamine N-acetyltransferase (NAT), a xenobiotic-metabolizing enzyme that enables acetyl coenzyme A-dependent detoxification of AA. To assess whether the N-acetylation pathway enables AA tolerance in Trichoderma spp., we cloned and characterized NATs from T. virens and T. reesei. We characterized recombinant enzymes by determining their catalytic efficiencies toward several toxic AA. Through a complementary approach, we also demonstrate that both Trichoderma species efficiently metabolize 3,4-DCA. Finally, we provide evidence that NAT-independent transformation is solely (in T. virens) or mainly (in T. reesei) responsible for the observed removal of 3,4-DCA. We conclude that T. virens and, to a lesser extent, T. reesei likely utilize another, unidentified, metabolic pathway for the detoxification of AA aside from acetylation. This is the first molecular and functional characterization of AA biotransformation in Trichoderma spp. Given the potential of Trichoderma for cleanup of contaminated soils, these results reveal new possibilities in the fungal remediation of AA-contaminated soil.

  9. Comparative genome sequence analysis underscores mycoparasitism as the ancestral life style of Trichoderma

    PubMed Central

    2011-01-01

    Background Mycoparasitism, a lifestyle where one fungus is parasitic on another fungus, has special relevance when the prey is a plant pathogen, providing a strategy for biological control of pests for plant protection. Probably, the most studied biocontrol agents are species of the genus Hypocrea/Trichoderma. Results Here we report an analysis of the genome sequences of the two biocontrol species Trichoderma atroviride (teleomorph Hypocrea atroviridis) and Trichoderma virens (formerly Gliocladium virens, teleomorph Hypocrea virens), and a comparison with Trichoderma reesei (teleomorph Hypocrea jecorina). These three Trichoderma species display a remarkable conservation of gene order (78 to 96%), and a lack of active mobile elements probably due to repeat-induced point mutation. Several gene families are expanded in the two mycoparasitic species relative to T. reesei or other ascomycetes, and are overrepresented in non-syntenic genome regions. A phylogenetic analysis shows that T. reesei and T. virens are derived relative to T. atroviride. The mycoparasitism-specific genes thus arose in a common Trichoderma ancestor but were subsequently lost in T. reesei. Conclusions The data offer a better understanding of mycoparasitism, and thus enforce the development of improved biocontrol strains for efficient and environmentally friendly protection of plants. PMID:21501500

  10. Rapeseed rotation, compost and biocontrol amendments reduce soilborne diseases and increase tuber yield in conventional and organic potato production systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three different potential disease-suppressive management practices, including a Brassica napus (rapeseed) green manure rotation crop, a conifer-based compost amendment, and three biological control organisms (Trichoderma virens, Bacillus subtilis, and Rhizoctonia solani hypovirulent isolate Rhs1A1)...

  11. Species diversity, distribution, and genetic structure of endophytic and epiphytic Trichoderma associated with banana roots.

    PubMed

    Xia, Xiaomin; Lie, Timothy K; Qian, Xiaoming; Zheng, Zhonghui; Huang, Yaojian; Shen, Yuemao

    2011-04-01

    Selective isolation, molecular identification and AFLP were used to investigate the distribution of the various species of endophytic and epiphytic Trichoderma associated with banana roots and to compare and contrast their genetic structure. Three specific groups of Trichoderma were observed in the roots of banana. Group one, which made up the largest population, comprised T. asperellum, T. virens, and Hypocrea lixii, which were isolated from both inside and on the surface of the banana roots, while group two, made up of T. atroviride and T. koningiopsis, existed on the surface only. Group three, comprising only T. brevicompactum was isolated from the inside of the roots. The AFLP analysis revealed Nei's diversity indices of 0.15 and 0.26 for epiphytic T. asperellum and T. virens, respectively. The index values of 0.11 and 0.11 were obtained for endophytic T. asperellum and T. virens, respectively. The genetic diversity within endophytic T. asperellum and T. virens was lower than that within the epiphytes. This suggests that endophytic Trichoderma has a higher genetic conservation and is compatible with the relatively stable microenvironments inside roots.

  12. Trichoderma-induced plant immunity likely involves both hormonal- and camalexin-dependent mechanisms in Arabidopsis thaliana and confers resistance against necrotrophic fungi Botrytis cinerea.

    PubMed

    Contreras-Cornejo, Hexon Angel; Macías-Rodríguez, Lourdes; Beltrán-Peña, Elda; Herrera-Estrella, Alfredo; López-Bucio, José

    2011-10-01

    Filamentous fungi belonging to the genus Trichoderma have long been recognized as agents for the biocontrol of plant diseases. In this work, we investigated the mechanisms involved in the defense responses of Arabidopsis thaliana seedlings elicited by co-culture with Trichoderma virens and Trichoderma atroviride. Interaction of plant roots with fungal mycelium induced growth and defense responses, indicating that both processes are not inherently antagonist. Expression studies of the pathogenesis-related reporter markers pPr1a:uidA and pLox2:uidA in response to T. virens or T. atroviride provided evidence that the defense signaling pathway activated by these fungi involves salicylic acid (SA) and/or jasmonic acid (JA) depending on the amount of conidia inoculated. Moreover, we found that Arabidopsis seedlings colonized by Trichoderma accumulated hydrogen peroxide and camalexin in leaves. When grown under axenic conditions, T. virens produced indole-3-carboxaldehyde (ICAld) a tryptophan-derived compound with activity in plant development. In Arabidopsis seedlings whose roots are in contact with T. virens or T. atroviride, and challenged with Botrytis cinerea in leaves, disease severity was significantly reduced compared to axenically grown seedlings. Our results indicate that the defense responses elicited by Trichoderma in Arabidopsis are complex and involve the canonical defense hormones SA and JA as well as camalexin, which may be important factors in boosting plant immunity.

  13. Biotransformation of Trichoderma spp. and Their Tolerance to Aromatic Amines, a Major Class of Pollutants

    PubMed Central

    Cocaign, Angélique; Bui, Linh-Chi; Silar, Philippe; Chan Ho Tong, Laetitia; Busi, Florent; Lamouri, Aazdine; Mougin, Christian; Rodrigues-Lima, Fernando

    2013-01-01

    Trichoderma spp. are cosmopolitan soil fungi that are highly resistant to many toxic compounds. Here, we show that Trichoderma virens and T. reesei are tolerant to aromatic amines (AA), a major class of pollutants including the highly toxic pesticide residue 3,4-dichloroaniline (3,4-DCA). In a previous study, we provided proof-of-concept remediation experiments in which another soil fungus, Podospora anserina, detoxifies 3,4-DCA through its arylamine N-acetyltransferase (NAT), a xenobiotic-metabolizing enzyme that enables acetyl coenzyme A-dependent detoxification of AA. To assess whether the N-acetylation pathway enables AA tolerance in Trichoderma spp., we cloned and characterized NATs from T. virens and T. reesei. We characterized recombinant enzymes by determining their catalytic efficiencies toward several toxic AA. Through a complementary approach, we also demonstrate that both Trichoderma species efficiently metabolize 3,4-DCA. Finally, we provide evidence that NAT-independent transformation is solely (in T. virens) or mainly (in T. reesei) responsible for the observed removal of 3,4-DCA. We conclude that T. virens and, to a lesser extent, T. reesei likely utilize another, unidentified, metabolic pathway for the detoxification of AA aside from acetylation. This is the first molecular and functional characterization of AA biotransformation in Trichoderma spp. Given the potential of Trichoderma for cleanup of contaminated soils, these results reveal new possibilities in the fungal remediation of AA-contaminated soil. PMID:23728813

  14. Evaluation of Trichoderma spp. for biocontrol of tomato sudden caused by Pythium aphanidermatum following flooding in tropical hot season.

    PubMed

    Le, H T T; Black, L L; Sikora, R A

    2003-01-01

    Tomato sudden death is a major problem in tomato production in tropical lowland areas. The plant wilts and dies following artificial or natural flooding for 48-72 hrs in the summer season. Occurrence of this disease is related to aggressiveness of Pythium aphanidermatum on tomato at high soil temperature (>30 degrees C). Several methods such as using biological control agents, fungicides and other cultural practices were applied in attempts to control tomato sudden death. Three Trichoderma harzianum and two Trichoderma virens isolates were evaluated for biocontrol of the disease in the greenhouse and in the field T. harzianum and T. virens isolates were separately used to treat the seed, potting medium and also incorporated into the soil before transplanting. Field soil was naturally infested with P. aphanidermatum, while greenhouse soil was inoculated with the pathogen 10 days after transplanting. All treatments were flooded for 48 hrs at 32 degrees C soil temperature. Results from this study show that most tested T. harzianum and T. virens isolates have little promise for control of tomato sudden death following flooding. The percentage of tomato plants that wilted after growing in soil treated with either T. harzianum or T. virens and P. aphanidermatum was not significantly different when compared to the soil treated with P. aphanidermatum alone. No wilted plants were observed in the control (non treated soil). PMID:15151279

  15. Borehole density on the surface of living Porites corals as an indicator of sedimentation in Hong Kong.

    PubMed

    Xie, James Y; Wong, Jane C Y; Dumont, Clement P; Goodkin, Nathalie; Qiu, Jian-Wen

    2016-07-15

    Borehole density on the surface of Porites has been used as an indicator of water quality in the Great Barrier Reef. We assessed the relationship between borehole density on Porites and eight water quality parameters across 26 sites in Hong Kong. We found that total borehole densities on the surface of Porites at 16 of the studied sites were high (>1000individualsm(-2)), with polychaetes being the dominant bioeroders. Sedimentation rate was correlated positively with total borehole density and polychaete borehole density, with the latter relationship having a substantially higher correlation of determination. None of the environmental factors used were significantly correlated with bivalve borehole density. These results provide a baseline for assessing future changes in coral bioerosion in Hong Kong. This present study also indicates that polychaete boreholes can be used as a bioindicator of sedimentation in the South China Sea region where polychaetes are numerically dominant bioeroders. PMID:27179996

  16. Size matters: The contribution of mega-infauna to the food webs and ecosystem services of an Oregon estuary - ESA

    EPA Science Inventory

    Background/Questions/Methods Large-bodied invertebrates (bivalves, polychaetes, burrowing shrimps) are common to infaunal communities of NE Pacific estuaries, but their contribution to estuarine community structure, function and ecosystem services is poorly understood because ...

  17. Size matters: The contribution of mega-infauna to the food webs and ecosystem services of an Oregon estuary - 9-30-12

    EPA Science Inventory

    Large-bodied invertebrates (bivalves, polychaetes, burrowing shrimps) are common to infaunal communities of NE Pacific estuaries, but their contribution to estuarine community structure, function and ecosystem services is poorly understood because they are difficult to sample and...

  18. Size Matters: The Contribution of Mega-Infauna to the Food Webs and Ecosystem Services of an Oregon Estuary

    EPA Science Inventory

    Large-bodied, invertebrates are common to infaunal communities of NE Pacific estuaries (e.g., bivalves, polychaetes, burrowing shrimps), but their contribution to the ecological structure, function and ecosystem services of most estuaries has been poorly characterized because the...

  19. DIGESTIVE BIOAVAILABILITY TO A DEPOSIT FEDDER (ARENICOLA MARINA) OF POLYCYCLIC AROMATIC HYDROCARBONS ASSOCIATED WITH ANTHRPOGENIC PARTICLES

    EPA Science Inventory

    Marine sediments around urban areas serve as catch basins for anthropogenic particles containing polycyclic aromatic hydrocarbons (PAHs). Using incubations with gut fluids extracted from a deposit-feeding polychaete (Arenicola marina), we determined the digestive bioavailability ...

  20. Effects of a brine discharge over soft bottom Polychaeta assemblage.

    PubMed

    Del-Pilar-Ruso, Yoana; De-la-Ossa-Carretero, Jose Antonio; Giménez-Casalduero, Francisca; Sánchez-Lizaso, Jose Luis

    2008-11-01

    Desalination is a growing activity that has introduced a new impact, brine discharge, which may affect benthic communities. Although the role of polychaetes as indicators to assess organic pollution is well known, their tolerance to salinity changes has not been examined to such a great extent. The aim of this study was to examine the effect of brine discharge over soft bottom polychaete assemblage along the Alicante coast (Southeast Spain) over a two year period. Changes in the polychaete assemblage was analysed using univariate and multivariate techniques. We compared a transect in front of the discharge with two controls. At each transect we sampled at three depths (4, 10 and 15 m) during winter and summer. We have observed different sensitivity of polychaete families to brine discharges, Ampharetidae being the most sensitive, followed by Nephtyidae and Spionidae. Syllidae and Capitellidae showed some resistance initially, while Paraonidae proved to be a tolerant family.

  1. A meta-analysis approach to the effects of fish farming on soft bottom polychaeta assemblages in temperate regions.

    PubMed

    Martinez-Garcia, Elena; Sanchez-Jerez, Pablo; Aguado-Giménez, Felipe; Ávila, Pablo; Guerrero, Alejandro; Sánchez-Lizaso, Jose Luis; Fernandez-Gonzalez, Victoria; González, Nieves; Gairin, Joan Ignasi; Carballeira, Carlos; García-García, Benjamín; Carreras, Jordi; Macías, Jose Carlos; Carballeira, Alejo; Collado, Cayetano

    2013-04-15

    Marine fish farms could cause environmental disturbances on the sediment due to uneaten food and fish faeces that impact the marine benthos. Polychaete assemblages are considered good indicators of environmental perturbations. The present study aimed to establish groups of polychaetes as potential indicators of fish farm pollution. This study was carried out in ten fish farms along the Spanish coast. Changes in polychaete assemblage were analyzed with meta-analysis and multivariate techniques. Abundance, richness and diversity showed significant decreases under fish farm conditions. Distribution patterns of polychaetes responded to combinations of physicochemical variables. The main ones are sulfide concentration, silt and clays percentage, and stable nitrogen isotope ratio. The results showed that some families are tolerant, Capitellidae, Dorvilleidae, Glyceridae, Nereididae, Oweniidae and Spionidae; while others are sensitive to fish farm pollution, Magelonidae, Maldanidae, Nephtyidae, Onuphidae, Paralacydoniidae, Paraonide, Sabellidae and also Cirratulidae in spite of being reported as a tolerant family.

  2. Borehole density on the surface of living Porites corals as an indicator of sedimentation in Hong Kong.

    PubMed

    Xie, James Y; Wong, Jane C Y; Dumont, Clement P; Goodkin, Nathalie; Qiu, Jian-Wen

    2016-07-15

    Borehole density on the surface of Porites has been used as an indicator of water quality in the Great Barrier Reef. We assessed the relationship between borehole density on Porites and eight water quality parameters across 26 sites in Hong Kong. We found that total borehole densities on the surface of Porites at 16 of the studied sites were high (>1000individualsm(-2)), with polychaetes being the dominant bioeroders. Sedimentation rate was correlated positively with total borehole density and polychaete borehole density, with the latter relationship having a substantially higher correlation of determination. None of the environmental factors used were significantly correlated with bivalve borehole density. These results provide a baseline for assessing future changes in coral bioerosion in Hong Kong. This present study also indicates that polychaete boreholes can be used as a bioindicator of sedimentation in the South China Sea region where polychaetes are numerically dominant bioeroders.

  3. Biochemical alterations induced in Hediste diversicolor under seawater acidification conditions.

    PubMed

    Freitas, Rosa; Pires, Adília; Moreira, Anthony; Wrona, Frederick J; Figueira, Etelvina; Soares, Amadeu M V M

    2016-06-01

    Seawater pH is among the environmental factors controlling the performance of marine organisms, especially in calcifying marine invertebrates. However, changes in non-calcifying organisms (including polychaetes) may also occur due to pH decrease. Polychaetes are often the most abundant group of organisms in estuarine systems, representing an important ecological and economic resource. Thus, the present study aimed to evaluate the impacts of seawater acidification in the polychaete Hediste diversicolor, a species commonly used as bioindicator. For this, organisms were exposed to different pH levels (7.9, 7.6 and 7.3) during 28 days and several biochemical markers were measured. The results obtained demonstrated that pH decrease negatively affected osmotic regulation and polychaetes metabolism, with individuals under low pH (7.6 and 7.3) presenting higher carbonic anhydrase activity, lower energy reserves (protein and glycogen content) and higher metabolic rate (measured as Electron transport system activity). The increase on CA activity was associated to organisms osmoregulation capacity while the increase on ETS and decrease on energy reserves was associated to the polychaetes capacity to develop defense mechanisms (e.g. antioxidant defenses). In fact, despite having observed higher lipid peroxidation at pH 7.6, in polychaetes at the lowest tested pH (7.3) LPO levels were similar to values recorded in individuals under control pH (7.9). Such findings may result from higher antioxidant enzyme activity at the lowest tested pH, which prevented organisms from higher oxidative stress levels. Overall, our study demonstrated how polychaetes may respond to near-future ocean acidification conditions, exhibiting the capacity to develop biochemical strategies which will prevent organisms from lethal injuries. Such defense strategies will contribute for polychaetes populations maintenance and survival under predicted seawater acidification scenarios. PMID:27088614

  4. New records to Chile of the Family Paraonidae (Annelida: Polychaeta)

    NASA Astrophysics Data System (ADS)

    Montiel, Américo; Hilbig, Brigitte; Rozbaczylo, Nicolás

    2002-06-01

    The Paraonidae are a polychaete family of small body size which have not been reported for Chile until recently. Mainly due to improved sample-processing methods, research campaigns carried out in 1994 and 1996 on three areas off southern Chile have yielded numerous records. Several species proved to be new to the Chilean polychaete fauna, including species that have been known previously only from Antarctic areas. These new records and range extensions are reported in this paper.

  5. MicroRNAs resolve an apparent conflict between annelid sy