Vanadium-Binding Ability of Nucleoside Diphosphate Kinase from the Vanadium-Rich Fan Worm, Pseudopotamilla occelata.

PubMed

Yamaguchi, Nobuo; Yoshinaga, Masafumi; Kamino, Kei; Ueki, Tatsuya

2016-06-01

Polychaete fan worms and ascidians accumulate high levels of vanadium ions. Several vanadiumbinding proteins, known as vanabins, have been found in ascidians. However, no vanadium-binding factors have been isolated from the fan worm. In the present study, we sought to identify vanadiumbinding proteins in the branchial crown of the fan worm using immobilized metal ion affinity chromatography. A nucleoside diphosphate kinase (NDK) homolog was isolated and determined to be a vanadium-binding protein. Kinase activity of the NDK homologue, PoNDK, was suppressed by the addition of V(IV), but was unaffected by V(V). The effect of V(IV) on PoNDK precedes its activation by Mg(II). This is the first report to describe the relationship between NDK and V(IV). PoNDK is located in the epidermis of the branchial crown, and its distribution is very similar to that of vanadium. These results suggest that PoNDK is associated with vanadium accumulation and metabolism in P. occelata.

Genotoxic damage in polychaetes: a study of species and cell-type sensitivities.

PubMed

Lewis, Ceri; Galloway, Tamara

2008-06-30

The marine environment is becoming increasingly contaminated by environmental pollutants with the potential to damage DNA, with marine sediments acting as a sink for many of these contaminants. Understanding genotoxic responses in sediment-dwelling marine organisms, such as polychaetes, is therefore of increasing importance. This study is an exploration of species-specific and cell-specific differences in cell sensitivities to DNA-damaging agents in polychaete worms, aimed at increasing fundamental knowledge of their responses to genotoxic damage. The sensitivities of coelomocytes from three polychaetes species of high ecological relevance, i.e. the lugworm Arenicola marina, the harbour ragworm Nereis diversicolor and the king ragworm Nereis virens to genotoxic damage are compared, and differences in sensitivities of their different coelomic cell types determined by use of the comet assay. A. marina was found to be the most sensitive to genotoxic damage induced by the direct-acting mutagen methyl methanesulfonate (MMS), and showed dose-dependent responses to MMS and the polycyclic aromatic hydrocarbon benzo(a)pyrene. Significant differences in sensitivity were also measured for the different types of coelomocyte. Eleocytes were more sensitive to induction of DNA damage than amoebocytes in both N. virens and N. diversicolor. Spermatozoa from A. marina showed significant DNA damage following in vitro exposure to MMS, but were less sensitive to DNA damage than coelomocytes. This investigation has clearly demonstrated that different cell types within the same species and different species within the polychaetes show significantly different responses to genotoxic insult. These findings are discussed in terms of the relationship between cell function and sensitivity and their implications for the use of polychaetes in environmental genotoxicity studies.

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

PubMed

Bakalenko, Nadezhda I; Novikova, Elena L; Nesterenko, Alexander Y; Kulakova, Milana A

2013-05-01

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. 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. 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.

Characterization of a New Ferritin Protein from the Polychaete Chaetopterus Sp.

NASA Astrophysics Data System (ADS)

Hamlish, N.; Deheyn, D.; De Meulenaere, E.

2016-02-01

The marine polychaete worm Chaetopterus sp. secretes a sticky mucus that exhibits a soft blue long-lasting bioluminescence. Iron (both ferrous and ferric) and riboflavin have been found abundant in the mucus and identified as potential cofactors involved in the control of the light production. The Deheyn lab has recently identified a novel ferritin protein (ChF) from fractions of the worm mucus still able to produce bioluminescence after purification by chromatography. Ferritin proteins are ubiquitous across the animal kingdom and exhibit ferroxidase activity, converting ferrous iron into a ferric form that is stably stored and soluble in the ferritin. Here, ferritin may serve as a source of biological iron for the worm through a process of iron acquisition, storage, and release during the light production process. This study addresses these options by assessing foundational data that characterize the ferroxidase activity of recombinant ChF with respect to human heavy-chain ferritin (HuHF). ChF exhibits faster initial rates of iron oxidation than HuHF, but reaches an equilibrium state with detectable levels of ferrous iron still in solution; in contrast this was was not observed for HuHF that oxidizes all available iron in solution. This may support the hypothesis that ChF has a reducing activity. This could involve the release of ferric iron, which may be reduced by flavin molecules found in the mucus; the resulting ferrous iron could then subsequently undergo a Fenton reaction, acting as a source of electrons for long-lasting mucus bioluminescence. Word Count: 240

Hydrodynamic Mediation of Killifish Predation on Infaunal Polychaetes

NASA Astrophysics Data System (ADS)

Hentschel, B. T.; Hayman, N. T.; Anderson, T. W.

2016-02-01

To explore predator-prey interactions between California killifish (Fundulus parvipinnis) and spionid polychaetes (Polydora cornuta and Streblospio benedicti) in tidal creeks, we conducted a laboratory flume experiment to quantify whether killifish prey-patch selectivity varies with flow speed. The flume included a 300-cm2 area of defaunated sediment within which we centrally positioned 24 P. cornuta, 24 S. benedicti, or no worms as a prey-free control. We videotaped groups of three killifish for 50 min at one of six unidirectional flow speeds (3, 6, 9, 12, 15, or 18 cm/s measured 1.5 cm above bottom) and recorded their bite rate anywhere in the sediment area vs. bites directed at the central prey patch (98 cm2). Each flow speed and prey treatment was replicated by four independent flume runs (i.e., 72 total flume runs). The percentage of bites directed at the central patch varied significantly with flow speed and worm presence. With defaunated sediment only, 33% of bites were directed at the central patch at all flow speeds, consistent with a null model of non-selective foraging. When either worm species inhabited the central patch, 65% of bites were directed at the central patch at 3 and 6 cm/s, and patch selectivity declined linearly as flow increased. Despite differences in morphology and behavior, the two prey species elicited similar foraging activity by killifish. We pooled the P. cornuta and S. benedicti treatments to determine the flow speed at which prey-patch selectivity by killifish became statistically indistinguishable from non-selective biting in the absence of prey. At flow speeds of 3, 6, and 9 cm/s, the percentage of bites located in the 98-cm2 patch was significantly greater when live worms were present compared to the prey-free controls. At 12, 15, and 18 cm/s, there was not a significant difference between the control patches and those containing live worms, indicating 12 cm/s is a flow threshold above which killifish cannot selectively forage on dense patches of infauna.

The Relationship Between Acoustic Target Strength and Body Length for Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus)

DTIC Science & Technology

2010-10-01

sturgeon feeding portray them as opportunistic benthivores, feeding primar- ily on mollusks, polychaete worms, amphipods, isopods, shrimp and small bottom...dwelling fishes and insect larvae (Gilbert 1989; Smith 1985). The Atlantic sturgeon is anadromous, entering freshwater rivers to spawn at water...bottom (small rubble, gravel, hard clay, and limestone) is required for successful egg attachment and incubation, while also protecting larvae from

Predation of intertidal infauna on juveniles of the bivalve Macoma balthica

NASA Astrophysics Data System (ADS)

Hiddink, J. G.; ter Hofstede, R.; Wolff, W. J.

2002-03-01

Juveniles of the bivalve Macoma balthica live on tidal flats in the Wadden Sea. This study examined the interaction of Macoma with the infaunal polychaetes Arenicola marina and Nereis diversicolor and the gastropod Retusa obtusa. The distribution of M. balthica spat on the flats, shortly after settlement in April, showed a positive correlation with the Arenicola distribution and a negative correlation with Nereis distribution. There were no locations where Macoma spat and Retusa occurred together. In August, Macoma spat had grown too large for predation by intertidal infauna. Small individuals of Macoma spat were found in stomachs of Arenicola (0.14 worm -1) and Nereis (0.05 worm -1). Laboratory experiments showed that Nereis and Retusa could reduce Macoma spat abundance, both in the absence and presence of sediment and alternative prey. Arenicola reduced the abundance of small Macoma (<1 mm) in sediment without, but not with, alternative prey. In field experiments, we manipulated the density of Arenicola in 0.25-1 m 2 plots and of Nereis in 0.03 m 2 cages and examined the effect on Macoma density several weeks later. We found a significant negative relation between densities of polychaetes and Macoma spat for both polychaete species in these experimental plots. Peculiarly, we found a significant positive relation between manipulated Nereis density and adult Macoma density in the cages; we cannot explain this. Consumption rates, calculated both from stomach contents and from field experiments, were 45 to 102 Macoma m -2 d -1 for Arenicola and 5 to 116 Macoma m -2 d -1 for Nereis. These values are higher than recorded consumption rates by epibenthic predators in the same area. Nevertheless, between-year differences in year-class strength could not be explained by differential abundance of these polychaetes. In conclusion, Arenicola and Nereis had a negative effect on the abundance of Macoma <1.5 mm, which was at least partly caused by direct consumption. Retusa obtusa can eat juvenile Macoma, but probably did not so in the study area, because there were no locations where Retusa and Macoma spat occurred together in the period that Macoma was <2 mm.

The impact of fossil data on annelid phylogeny inferred from discrete morphological characters.

PubMed

Parry, Luke A; Edgecombe, Gregory D; Eibye-Jacobsen, Danny; Vinther, Jakob

2016-08-31

As a result of their plastic body plan, the relationships of the annelid worms and even the taxonomic makeup of the phylum have long been contentious. Morphological cladistic analyses have typically recovered a monophyletic Polychaeta, with the simple-bodied forms assigned to an early-diverging clade or grade. This is in stark contrast to molecular trees, in which polychaetes are paraphyletic and include clitellates, echiurans and sipunculans. Cambrian stem group annelid body fossils are complex-bodied polychaetes that possess well-developed parapodia and paired head appendages (palps), suggesting that the root of annelids is misplaced in morphological trees. We present a reinvestigation of the morphology of key fossil taxa and include them in a comprehensive phylogenetic analysis of annelids. Analyses using probabilistic methods and both equal- and implied-weights parsimony recover paraphyletic polychaetes and support the conclusion that echiurans and clitellates are derived polychaetes. Morphological trees including fossils depict two main clades of crown-group annelids that are similar, but not identical, to Errantia and Sedentaria, the fundamental groupings in transcriptomic analyses. Removing fossils yields trees that are often less resolved and/or root the tree in greater conflict with molecular topologies. While there are many topological similarities between the analyses herein and recent phylogenomic hypotheses, differences include the exclusion of Sipuncula from Annelida and the taxa forming the deepest crown-group divergences. © 2016 The Authors.

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. © 2014 The Authors. Geobiology Published by John Wiley & Sons Ltd.

Discovery of intermediate hosts for two species of blood flukes Cardicola orientalis and Cardicola forsteri (Trematoda: Aporocotylidae) infecting Pacific bluefin tuna in Japan.

PubMed

Shirakashi, Sho; Tani, Kazuki; Ishimaru, Katsuya; Shin, Sang Phil; Honryo, Tomoki; Uchida, Hiro'omi; Ogawa, Kazuo

2016-04-01

Fish blood flukes (Aporocotylidae) are important pathogens of farmed finfish around the world. Among them, Cardicola spp. infecting farmed tuna are considered to be serious threats to tuna farming and have received tremendous attention. We conducted periodical samplings at a tuna farming site in Japan between January and May, 2015 to determine the life cycle of Cardicola spp. We collected over 4700 terebellid polychaetes from ropes, floats and frames of tuna culture cages and found nearly 400 infected worms. Sporocysts and cercariae found in Nicolea gracilibranchis were genetically identified as Cardicola orientalis by 28S and ITS2 ribosomal DNA sequences. This was the first discovery of the intermediate host for this parasite species. Infection prevalence and the abundance of N. gracilibranchis significantly varied between sampling points and the highest number of infected terebellids were collected from ropes. We also demonstrated morphologically and molecularly that asexual stages found in a single Amphitrite sp. (Terebellidae) and adult worms isolated from farmed juvenile tuna were Cardicola forsteri. This is the first report of C. forsteri in Pacific bluefin tuna (PBT) Thunnus orientalis in Japan. Our results demonstrated that all three species of Cardicola orientalis, C. forsteri and Cardicola opisthorchis exist in Japanese farmed PBTs and that they all use terebellid polychaetes as the intermediate hosts. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Biodynamic modelling of the accumulation of Ag, Cd and Zn by the deposit-feeding polychaete Nereis diversicolor: inter-population variability and a generalised predictive model.

PubMed

Kalman, J; Smith, B D; Riba, I; Blasco, J; Rainbow, P S

2010-06-01

Biodynamic parameters of the ragworm Nereis diversicolor from southern Spain and south England were experimentally derived to assess the inter-population variability of physiological parameters of the bioaccumulation of Ag, Cd and Zn from water and sediment. Although there were some limited variations, these were not consistent with the local metal bioavailability nor with temperature changes. Incorporating the biodynamic parameters into a defined biodynamic model, confirmed that sediment is the predominant source of Cd and Zn accumulated by the worms, accounting in each case for 99% of the overall accumulated metals, whereas the contribution of dissolved Ag to the total accumulated by the worm increased from about 27 to about 53% with increasing dissolved Ag concentration. Standardised values of metal-specific parameters were chosen to generate a generalised model to be extended to N. diversicolor populations across a wide geographical range from western Europe to North Africa. According to the assumptions of this model, predicted steady state concentrations of Cd and Zn in N. diversicolor were overestimated, those of Ag underestimated, but still comparable to independent field measurements. We conclude that species-specific physiological metal bioaccumulation parameters are relatively constant over large geographical distances, and a single generalised biodynamic model does have potential to predict accumulated Ag, Cd and Zn concentrations in this polychaete from a single sediment metal concentration.

Proceraea exoryxae sp. nov. (Annelida, Syllidae, Autolytinae), the first known polychaete miner tunneling into the tunic of an ascidian

PubMed Central

Nygren, Arne

2017-01-01

While studying organisms living in association with the solitary tunicate Phallusia nigra (Ascidiacea, Ascidiidae) from a shallow fringing reef at Zeytouna Beach (Egyptian Red Sea), one of the collected ascidians showed peculiar perforations on its tunic. Once dissected, the perforations revealed to be the openings of a network of galleries excavated in the inner tunic (atrium) by at least six individuals of a polychaetous annelid. The worms belonged to the Autolytinae (Syllidae), a subfamily that is well known to include specialized predators and/or symbionts, mostly associated with cnidarians. The Red Sea worms are here described as Proceraea exoryxae sp. nov., which are anatomically distinguished by the combination of simple chaetae only in anterior chaetigers, and a unique trepan with 33 teeth in one outer ring where one large tooth alternates with one medium-sized tricuspid tooth, and one inner ring with small teeth located just behind the large teeth. Male and female epitokes were found together with atokous individuals within galleries. Proceraea exoryxae sp. nov. constitutes the first known miner in the Autolytinae and the second species in this taxon known to live symbiotically with ascidians. The implications of finding this specialized parasite are discussed considering that Phallusia nigra has been introduced worldwide, in tropical and sub-tropical ecosystems, where it has the potential of becoming invasive. PMID:28584710

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 inmore » 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.« less

Aspects on gametogenesis, fertilization and embryogenesis of two deep-sea polychaetes from Eastern Atlantic cold seeps

NASA Astrophysics Data System (ADS)

Gaudron, S. M.; Hourdez, S.; Olu, K.

2017-11-01

We investigated two gonochoristic species of annelid polychaetes (one siboglinid and one polynoid) from cold seeps that ranged from 525 m to 3300 m in depth (Guiness, Worm Hole and Regab pockmarks) on the Gabon and Congo continental margins (Gulf of Guinea). Different aspects of gametogenesis (oocyte diameter, presence of ovisac, spermatozoa shape, and fecundity), fertilization (in vitro fertilization experiments: IVF) and embryogenesis (cleavage rate) were studied. The sampled siboglinid was a new species of Lamellibrachia and the second population of this genus in the Eastern Atlantic. Mean oocyte diameter was about 100 μm and fully-grown primary oocytes were stored in an ovisac, as in other studied siboglinids. The presence of a single spermatozoon was noted within an oviduct, indicating a possible internal fertilization. The rate of cell division at 6 °C was one cleavage every 20 h. Embryos developed normally to the blastula stage after 5-d post-fertilization at atmospheric pressure suggesting some pressure tolerance. The second polychaete was the scale-worm Branchipolynoe cf. seepensis that lives in commensalism in the mantle cavity of Bathymodiolus aff. boomerang. Anatomical reproductive features were similar to those described in B. seepensis from hydrothermal vents on Mid-Atlantic Ridge, with lecithotrophic larval development and continuous gametogenesis. We performed the first IVF carried out on gametes for any deep-sea polynoid species. Fertilization and development occurred but a number of abnormalities were observed demonstrating a limitation to embryogenesis at atmospheric pressure. The rate of cell division was three times faster at 8 °C than at 4 °C with a maximum stage of 8-cells reached after 72 h post-fertilization. We surprisingly observed some oocytes from the negative seawater control during IVF experiments cleaved to the 2-cell stage, demonstrating the possible occurrence of internal fertilization prior to IVF experiment or the accidental release of sperm from the female's spermatheca.

Meandering worms: mechanics of undulatory burrowing in muds

PubMed Central

Dorgan, Kelly M.; Law, Chris J.; Rouse, Greg W.

2013-01-01

Recent work has shown that muddy sediments are elastic solids through which animals extend burrows by fracture, whereas non-cohesive granular sands fluidize around some burrowers. These different mechanical responses are reflected in the morphologies and behaviours of their respective inhabitants. However, Armandia brevis, a mud-burrowing opheliid polychaete, lacks an expansible anterior consistent with fracturing mud, and instead uses undulatory movements similar to those of sandfish lizards that fluidize desert sands. Here, we show that A. brevis neither fractures nor fluidizes sediments, but instead uses a third mechanism, plastically rearranging sediment grains to create a burrow. The curvature of the undulating body fits meander geometry used to describe rivers, and changes in curvature driven by muscle contraction are similar for swimming and burrowing worms, indicating that the same gait is used in both sediments and water. Large calculated friction forces for undulatory burrowers suggest that sediment mechanics affect undulatory and peristaltic burrowers differently; undulatory burrowing may be more effective for small worms that live in sediments not compacted or cohesive enough to extend burrows by fracture. PMID:23446526

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 fractions. TAM and/or total protein may represent an approximate minimum for trophic availability but neither of these alone is a fully accurate predictor. ?? Inter-Research 2006.

Microplastic fibers in the intertidal ecosystem surrounding Halifax Harbor, Nova Scotia.

PubMed

Mathalon, Alysse; Hill, Paul

2014-04-15

Humans continue to increase the use and disposal of plastics by producing over 240 million tonnes per year, polluting the oceans with persistent waste. The majority of plastic in the oceans are microplastics (<5 mm). In this study, the contamination of microplastic fibers was quantified in sediments from the intertidal zones of one exposed beach and two protected beaches along Nova Scotia's Eastern Shore. From the two protected beaches, polychaete worm fecal casts and live blue mussels (Mytilus edulis) were analyzed for microplastic content. Store-bought mussels from an aquaculture site were also analyzed. The average microplastic abundance observed from 10 g sediment subsamples was between 20 and 80 fibers, with higher concentrations at the high tide line from the exposed beach and at the low tide line from the protected beaches. Microplastic concentrations from polychaete fecal casts resembled concentrations quantified from low tide sediments. In two separate mussel analyses, significantly more microplastics were enumerated in farmed mussels compared to wild ones. Copyright © 2014 Elsevier Ltd. All rights reserved.

Acteonidae, Bullinidae and Ringiculidae (Gastropoda: Heterobranchia) from the Plio-Pleistocene of the Philippines.

PubMed

Helwerda, Renate A

2015-07-24

Twenty-three species of Acteonidae, Bullinidae and Ringiculidae are documented from the so-called "Cabarruyan" fauna from the Plio-Pleistocene of Pangasinan, the Philippines. There are eleven species of Acteonidae, one species of Bullinidae and eleven species of Ringiculidae. Seven species are described here as new, these are: Bathyacteon valdesi nov. spec., Bullina virgoides nov. spec., Ringicula bella nov. spec., R. circumscripta nov. spec., R. caelestis nov. spec., R. opima nov. spec. and Microglyphis angulata nov. spec.. The presence of Acteonidae and Bullinidae indicates that polychaete worms were also present.

Field Verification Program (Aquatic Disposal). Effects of Black Rock Harbor Dredged Material on the Histopathology of The Blue Mussel Mytilus edulis and Polychaete Worm Nephtys incisa After Laboratory and Field Exposures.

DTIC Science & Technology

1987-09-01

reproductive tract from animal collected at 400E on T + 2. Photomicrograph shows normal ova, cytoplasm, and vitelline membrane ......................... 92 40...was brought to the laboratory, where it was sieved and the N. incisa were picked and sorted by size. Tests were con- ducted with adult specimens...palps, the esophagus, the stomach, the intestine and digestive diverticula ducts and tubules), the byssus organ, the muscles, and the connective

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.

Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in South San Francisco Bay, California-2010

USGS Publications Warehouse

Dyke, Jessica; Parcheso, Francis; Thompson, Janet K.; Cain, Daniel J.; Luoma, Samuel N.; Hornberger, Michelle I.

2011-01-01

Analyses of the benthic community structure of a mudflat in South San Francisco Bay over a 37-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinel clam, M. petalum, from the same area. Analysis of the M. petalum community shows increases in reproductive activity concurrent with the decline in metal concentrations in the tissues of this organism. Reproductive activity is presently stable (2010), with almost all animals initiating reproduction in the fall and spawning the following spring of most years. The community has shifted from being dominated by several opportunistic species to a community where the species are more similar in abundance, a pattern that indicates a more stable community that is subjected to fewer stressors. In addition, two of the opportunistic species (Ampelisca abdita and Streblospio benedicti) that brood their young and live on the surface of the sediment in tubes have shown a continual decline in dominance coincident with the decline in metals; both species had short-lived rebounds in abundance in 2008, 2009, and 2010. Heteromastus filiformis (a subsurface polychaete worm that lives in the sediment, consumes sediment and organic particles residing in the

Are Sediments a Source of Fukushima Radiocesium for Marine Fauna in Coastal Japan?

NASA Astrophysics Data System (ADS)

Wang, C.; Fisher, N. S.; Baumann, Z.

2016-02-01

The Fukushima nuclear power plant accident in 2011 resulted in the largest accidental release of artificial radionuclides into the world's oceans. Among the fission products released in large quantities, 137Cs has the greatest potential for long-term impacts on marine biota and human consumers of seafood. In particular, some species of bottom fish near Fukushima were very contaminated and had higher radiocesium (134Cs and 137Cs) levels than pelagic fish in the same area, sometimes exceeding Japanese safety limits >4 years after the accident. Benthic invertebrates, many being prey items for bottom fish, show the same slow decrease in radiocesium as sediments, suggesting that contaminated sediment could be a source of radiocesium for benthic fauna. We evaluated the binding of 137Cs to sediments (Kd found to be 44-60 ml g-1) and found that bioturbation by the polychaete Nereis succinea greatly increased the initial release rate of Cs to overlying seawater. We also assessed the bioavailability of dissolved and sediment-bound Cs for deposit-feeding polychaetes, and its subsequent transfer to crabs and fish, and measured the influence of water temperature on Cs accumulation in fish. Assimilation efficiency (AE) of ingested 137Cs ranged from 16% in polychaetes ingesting sediments to 79% in fish ingesting worms. Efflux rate constants ranged from 5% d-1 for killifish to 40% d-1 for polychaetes. Animal absorption and retention of dissolved 137Cs were also measured. These parameters are used to model radiocesium bioaccumulation and trophic transfer in benthic food chains. Our results are consistent with the idea that sediments can be an important source of Cs for benthic food chains and help explain why some species of bottom fish remained more contaminated than pelagic fish in Japanese coastal waters.

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.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neff, Jerry M.; Boehm, Paul D.; Kropp, Roy K.

We determined the bioavailability to sediment dwelling marine worms of polycyclic aromatic hydrocarbons (PAHs) associated with offshore sediments from 3 spill path and 3 non-spill path areas of Prince William Sound (PWS), Alaska, 12 years after the Exxon Valdez oil spill. The PAHs in sediments from 4 sites sampled in 2001 were primarily from a regional natural petrogenic background derived from organic-rich shales and natural oil seeps associated with sources southeast of PWS. Pyrogenic (combustion) PAHs, primarily from former human and industrial activities, were more abundant than petrogenic PAHs in nearshore sediments from 2 bays associated with past and currentmore » human activities. We performed sediment bioaccumulation tests with the six sediments and polychaete worms according to standard EPA protocols. All the PAHs had a very low bioavailability, as indicated by low values for biota/sediment accumulation factors (BSAFs) in the worms. Mean BSAFs for total PAHs (sum of 41 analyte groups) ranged from 0.002 to 0.009. The worms exposed to spill path and non-spill path sediments bioaccumulated small amounts of 4- and 5-ring PAHs, particularly fluoranthene and pyrene; these higher molecular weight PAHs are responsible for induction of mixed function oxygenase (MFO) activity in marine fish, birds, and mammals. These results may help to explain in part why fish from throughout PWS exhibit induced MFO activity. Elevated levels of MFO activity cannot be used as evidence of recent exposure by marine fish, birds, and mammals in the sound to Exxon Valdez oil.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 hydrocarbonsmore » (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.« less

Hemichordate models.

PubMed

Tagawa, Kuni

2016-08-01

Hemichordates are marine animals with two different lifestyles. The solitary, free-living enteropneusts or acorn worms resemble polychaetes or earthworms, while the tiny, colonial, sessile pterobranchs are similar to bryozoans and phoronids. Hemichordates, together with echinoderms, comprise the clade Ambulacraria and are a sister group to the Chordata. As adults, they exhibit cardinal chordate characters, such as gill slits. Their embryogenesis and dipleurula-type (tornaria) larvae are very similar to those of echinoderms. Recent advances in comparative genomics and molecular developmental biology of hemichordates, especially the vermiform enteropneusts, have shed light on deuterostome ancestors. This paper briefly reviews the numerous recent studies on the Phylum Hemichordata. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative neuroanatomy suggests repeated reduction of neuroarchitectural complexity in Annelida

PubMed Central

2010-01-01

Background Paired mushroom bodies, an unpaired central complex, and bilaterally arranged clusters of olfactory glomeruli are among the most distinctive components of arthropod neuroarchitecture. Mushroom body neuropils, unpaired midline neuropils, and olfactory glomeruli also occur in the brains of some polychaete annelids, showing varying degrees of morphological similarity to their arthropod counterparts. Attempts to elucidate the evolutionary origin of these neuropils and to deduce an ancestral ground pattern of annelid cerebral complexity are impeded by the incomplete knowledge of annelid phylogeny and by a lack of comparative neuroanatomical data for this group. The present account aims to provide new morphological data for a broad range of annelid taxa in order to trace the occurrence and variability of higher brain centers in segmented worms. Results Immunohistochemically stained preparations provide comparative neuroanatomical data for representatives from 22 annelid species. The most prominent neuropil structures to be encountered in the annelid brain are the paired mushroom bodies that occur in a number of polychaete taxa. Mushroom bodies can in some cases be demonstrated to be closely associated with clusters of spheroid neuropils reminiscent of arthropod olfactory glomeruli. Less distinctive subcompartments of the annelid brain are unpaired midline neuropils that bear a remote resemblance to similar components in the arthropod brain. The occurrence of higher brain centers such as mushroom bodies, olfactory glomeruli, and unpaired midline neuropils seems to be restricted to errant polychaetes. Conclusions The implications of an assumed homology between annelid and arthropod mushroom bodies are discussed in light of the 'new animal phylogeny'. It is concluded that the apparent homology of mushroom bodies in distantly related groups has to be interpreted as a plesiomorphy, pointing towards a considerably complex neuroarchitecture inherited from the last common ancestor, Urbilateria. Within the annelid radiation, the lack of mushroom bodies in certain groups is explained by widespread secondary reductions owing to selective pressures unfavorable for the differentiation of elaborate brains. Evolutionary pathways of mushroom body neuropils in errant polychaetes remain enigmatic. PMID:20441583

Physical and biological factors affecting the behaviour and mortality of hydrothermal vent tubeworms (vestimentiferans)

NASA Astrophysics Data System (ADS)

Tunnicliffe, Verena; Garrett, John F.; Johnson, H. Paul

1990-01-01

Vestimentiferan tubeworms of two hydrothermal vents on Juan de Fuca Ridge, northeast Pacific, were photographed with a time-lapse camera over periods of 1, 5 and 26 days and supplemented with video for 25 min. Current and turbidity measurements were also made. Mortality of the worms was heavy: 44% of the worms studied in the 26-day period were removed by falling sulphate/sulphide spires or died for other reasons. Predation effects are very common among collected specimens and implicate the activities of photographed rat-tail fish and polynoid polychaetes. Time-lag auto-correlations reveal a discernible semidiurnal and diurnal periodicity in the retraction/extension movements of the vestimentiferan population. However, no direct correlation exists with measures of surrounding currents or suspended particulates that have clear tidal components to their periodicity. Worms in each series were examined individually but no consistent endogenous rhythm could be identified. Worms are sensitive to touch and the approach of predators and exhibit rapid retraction responses. Although they do not appear to respond to the second-to-minute scale variations in sorrounding fluids, their short-term behaviour is highly variable. Over many days, the retractions/extension profile of each worm is quite constant and perhaps is the expression of a constant metanolic rate. The two species examined differ substantially, with less than half the Ridgeia piscesae being extended at any time compared to 3/4 of the R. phaeophiale population. Periods of retraction frequenlly last more than 30 min which man produce anaerobic conditions within the tube. Uptake of dissolved gases, and thus metabolic rate, is likely affected by both the specific retraction behaviour and branchial filament loss to predators.

Physical habitat predictors of Manayunkia speciosa distribution in the Klamath River and implications for management of Ceratomyxa shasta, a parasite with a complex life cycle

NASA Astrophysics Data System (ADS)

Jordan, M. S.; Alexander, J. D.; Grant, G. E.; Bartholomew, J. L.

2011-12-01

Management strategies for parasites with complex life cycles may target not the parasite itself, but one of the alternate hosts. One approach is to decrease habitat for the alternate host, and in river systems flow manipulations may be employed. Two-dimensional hydraulic models can be powerful tools for predicting the relationship between flow alterations and changes in physical habit, however they require a rigorous definition of physical habitat for the organism of interest. We present habitat characterization data for the case of the alternate host of a salmonid parasite and introduce how it will be used in conjunction with a 2-dimensional hydraulic model. Ceratomyxa shasta is a myxozoan parasite of salmonids that requires a freshwater polychaete Manayunkia speciosa to complete its life cycle. Manayunkia speciosa is a small (3mm) benthic filter-feeding worm that attaches itself perpendicularly to substrate through construction of a flexible tube. In the Klamath River, CA/OR, C. shasta causes significant juvenile salmon mortality, imposing social and economic losses on commercial, sport and tribal fisheries. An interest in manipulating habitat for the polychaete host to decrease the abundance of C. shasta has therefore developed. Unfortunately, there are limited data on the habitat requirements of M. speciosa or the influence of streamflow regime and hydraulics on population dynamics and infection prevalence. This work aims to address these data needs by identifying physical habitat variables that influence the distribution of M. speciosa and determining the relationship between those variables, M. speciosa population density, and C. shasta infection prevalence. Biological samples were collected from nine sites representing three river features (runs, pools, and eddies) within the Klamath River during the summer and fall of 2010 and 2011. Environmental data including depth, velocity, and substrate, were collected at each polychaete sampling location. We tested for differences in environmental variables and polychaete densities among months and river features. Preliminary data suggest differences in density among months and river features as well as relationships among density and water velocity and substrate type. Polychaetes are currently being assayed for C. shasta infection, which will ultimately be included in our analyses. The data will subsequently be used in conjunction with a 2-dimensional hydraulic model to evaluate habitat stability and the influence of varied streamflow senarios.

Christmas tree worms of Indo-Pacific coral reefs: untangling the Spirobranchus corniculatus (Grube, 1862) complex

NASA Astrophysics Data System (ADS)

Willette, Demian A.; Iñiguez, Abril R.; Kupriyanova, Elena K.; Starger, Craig J.; Varman, Tristan; Toha, Abdul Hamid; Maralit, Benedict A.; Barber, Paul H.

2015-09-01

Christmas tree worm is the common name of a group of colorful serpulid polychaetes from the genus Spirobranchus that are symbionts of hermatypic corals. As is increasingly common with reef-associated organisms, Spirobranchus is arranged as a complex of species with overlapping geographic ranges. Current species delimitations based largely on opercular morphology are problematic because of high intraspecific variation. Here, a multi-gene phylogeny of the Spirobranchus corniculatus complex, which tentatively includes S. corniculatus, S. cruciger, and S. gaymardi, sampled from the Coral Triangle, Australia, and Fiji, was reconstructed to test whether the complex includes three genetically distinct lineages identifiable by their opercula. Maximum-likelihood analyses of nuclear and mitochondrial markers revealed a single, monophyletic clade for the S. corniculatus complex. Furthermore, the genetic and morphological variation observed is not geographically based, indicating that the former S. corniculatus complex of three morphospecies is a single, morphologically variable species across the Central Indo-Pacific. Resolving the taxonomy of S. corniculatus presents novel opportunities to utilize this tentative bio-indicator species for monitoring reef health.

Bioaccumulation and biological effects of cigarette litter in marine worms

PubMed Central

Wright, Stephanie L.; Rowe, Darren; Reid, Malcolm J.; Thomas, Kevin V.; Galloway, Tamara S.

2015-01-01

Marine debris is a global environmental issue. Smoked cigarette filters are the predominant coastal litter item; 4.5 trillion are littered annually, presenting a source of bioplastic microfibres (cellulose acetate) and harmful toxicants to marine environments. Despite the human health risks associated with smoking, little is known of the hazards cigarette filters present to marine life. Here we studied the impacts of smoked cigarette filter toxicants and microfibres on the polychaete worm Hediste diversicolor (ragworm), a widespread inhabitant of coastal sediments. Ragworms exposed to smoked cigarette filter toxicants in seawater at concentrations 60 fold lower than those reported for urban run-off exhibited significantly longer burrowing times, >30% weight loss, and >2-fold increase in DNA damage compared to ragworms maintained in control conditions. In contrast, ragworms exposed to smoked cigarette filter microfibres in marine sediment showed no significant effects. Bioconcentration factors for nicotine were 500 fold higher from seawater than from sediment. Our results illustrate the vulnerability of organisms in the water column to smoking debris and associated toxicants, and highlight the risks posed by smoked cigarette filter debris to aquatic life. PMID:26369692

Studies on the origin and distribution of palytoxin in a Caribbean coral reef.

PubMed

Gleibs, S; Mebs, D; Werding, B

1995-11-01

In coral reefs of the Caribbean Sea (Colombia) palytoxin (PTX) has been detected in zoanthid species of the genera Palythoa and Zoanthus by assaying the delayed haemolysis in human erythrocytes produced by aqueous extracts, which is inhibited by ouabain pretreatment, and by HPLC. The toxin content of the polyps and colonies is highly variable and is not correlated with their reproductive cycle or with the amount of symbiotic algae. Sequestration of PTX has been observed in crustaceans (Platypodiella sp.) living in close association with Palythoa colonies and in polychaete worms (Hermodice carunculata) feeding on the zoanthids. Resistance of marine animals to the toxin may enable it to enter food chains.

The role of certain infauna and vascular plants in the mediation of redox reactions in marine sediments

NASA Technical Reports Server (NTRS)

Hines, Mark E.

1992-01-01

The mechanisms by which certain animals and plants affect redox processes in sediments was examined by studying three environments: (1) subtidal sediments dominated by the deposit-feeding polychaete Heteromastus filiformis; (2) a saltmarsh inhabited by the tall form of Spartina alterniflora; and (3) tropical carbonate sediments inhabited by three species of seagrasses. S-35-sulfide production rates were compared to pool sizes of dissolved sulfide and dissolved iron. In all of the sediments studied, rates of sulfide reduction were enhanced by macroorganisms while the rate of turnover of dissolved sulfide increased. The polychaete enhanced microbial activity and redox cycling primarily by subducting particles of organic matter and oxidized iron during sediment reworking. The Spartina species enhanced anaerobic activity by transporting primarily dissolved organic matter and oxidants. Although the final result of both animal and plant activities was the enhancement of sub-surface cycling of sulfur and iron, decreased dissolved sulfide and increased dissolved iron concentrations, the mechanisms which produced these results differed dramatically.

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.

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 modification. PMID:24098816

Reducing the data-deficiency of threatened European habitats: Spatial variation of sabellariid worm reefs and associated fauna in the Sicily Channel, Mediterranean Sea.

PubMed

Bertocci, Iacopo; Badalamenti, Fabio; Lo Brutto, Sabrina; Mikac, Barbara; Pipitone, Carlo; Schimmenti, Eugenia; Vega Fernández, Tomás; Musco, Luigi

2017-09-01

Biogenic reefs, such as those produced by tube-dwelling polychaetes of the genus Sabellaria, are valuable marine habitats which are a focus of protection according to European legislation. The achievement of this goal is potentially hindered by the lack of essential empirical data, especially in the Mediterranean Sea. This study addresses some of the current knowledge gaps by quantifying and comparing multi-scale patterns of abundance and distribution of two habitat-forming species (Sabellaria alveolata and S. spinulosa) and their associated fauna along 190 km of coast on the Italian side of the Sicily Channel. While the abundance of the two sabellariids and the total number of associated taxa did not differ at any of the examined scales (from tens of centimetres to tens-100 of kilometres), the structure (composition in terms of both the identity and the relative abundance of constituting taxa) of the associated fauna and the abundance of several taxa (the polychaetes Eulalia ornata, Syllis pulvinata, S. garciai, Nereis splendida and Arabella iricolor, and the amphipods Apolochus neapolitanus, Tethylembos viguieri and Caprella acanthifera) varied among locations established ∼50-100 km apart. Syllis pulvinata also showed significant variation between sites (hundreds of metres apart), analogously to the other syllid polychaetes S. armillaris and S. gracilis, the nereidid polychaete Nereis rava, and the amphipod Gammaropsis ulrici. The largest variance of S. spinulosa, of the structure of the whole associated fauna and of 56% of taxa analysed individually occurred at the scale of replicates (metres apart), while that of the dominant bio-constructor S. alveolata and of 25% of taxa occurred at the scale of sites. The remaining 19% and the total richness of taxa showed the largest variance at the scale of locations. Present findings contribute to meet a crucial requirement of any future effective protection strategy, i.e., identifying relevant scales of variation to be included in protection schemes aiming at preserving representative samples not only of target habitats and organisms, but also of the processes driving such variability. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sediment reworking by a polychaete, Perinereis aibuhitensis, in the intertidal sediments of the Gomso Bay, Korea

NASA Astrophysics Data System (ADS)

Koo, Bon Joo; Seo, Jaehwan

2017-12-01

Bioturbation, especially sediment reworking by the activities of macroinvertebrates, such as feeding and burrowing, is one of the major processes that affect the physical, chemical, and biological characteristics of marine sediments. Given the importance of sediment reworking, this study was designed to evaluate the sediment reworking rate of a polychaete, Perinereis aibuhitensis, which is dominant in the upper tidal flats on the west coast of Korea, based on quantification of pellet production during spring and fall surveys. The density of individuals was higher in fall than in spring, whereas, due to a difference in the proportion of adults between the two seasons, the morphometric dimensions of the worm and its pellets were significantly longer and heavier in the spring. Hourly pellet production per inhabitant and density were closely related, with pellet production gradually decreasing as density increased. Daily pellet production was much higher in spring than in fall, mostly due to an increase in daytime production. The sediment reworking rate of Perinereis was similar in the two seasons in which observations were made and depended on its density and the sediment reworking rate per individual. The overall sediment reworking rate of Perinereis was 31 mm yr-1 based on its density in the study area.

Ecophysiological capability of Marenzelleria populations inhabiting North Sea estuaries: an overview

NASA Astrophysics Data System (ADS)

Schiedek, Doris

1998-09-01

The metabolic responses of Marenzelleria cf. wireni, a newly established polychaete worm within North Sea estuaries, to various kinds of environmental stress are summarised. With respect to salinity, M. cf. wireni is able to deal with variations within a wide range. In the process of osmotic acclimation, free amino acids are involved. The major amino acid in terms of osmotic effector is glycine, followed by alanine. Under severe hypoxia, M. cf. wireni switches to an anaerobic metabolism, but at a very low oxygen partial pressure (<3 kPa), which indicates efficient utilisation of oxygen. Anaerobic energy production occurs predominantly via the succinate-propionate pathway. When exposed to hydrogen sulphide, M. cf. wireni is able to cope with high sulphide concentrations (up to 3 mmol l-1), but the pattern of end products of the anaerobic energy metabolism changes. In terms of sulphide tolerance, M. cf. wireni probably is even better adapted than other, indigenous polychaetes. However, in comparison with the sibling species Marenzelleria viridis, which appeared at the same time in European waters but mainly inhabits the coastal inlets of the Baltic Sea in high numbers, the metabolic capabilities of M. cf. wireni seem to be more limited at higher sulphide concentrations (>1 mmol l-1). This might have an influence on the distribution pattern of the two sibling species.

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. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Trophodynamic linkage between river runoff and coastal fishery yield elucidated by stable isotope data in the Gulf of Lions (NW Mediterranean).

PubMed

Darnaude, Audrey M; Salen-Picard, Chantal; Polunin, Nicholas V C; Harmelin-Vivien, Mireille L

2004-02-01

The link between climate-driven river runoff and sole fishery yields observed in the Gulf of Lions (NW Mediterranean) was analysed using carbon- and nitrogen stable isotopes along the flatfish food webs. Off the Rhone River, the main terrestrial (river POM) and marine (seawater POM) sources of carbon differed in delta(13)C (-26.11 per thousand and -22.36 per thousand, respectively). Surface sediment and suspended POM in plume water exhibited low delta(13)C (-24.38 per thousand and -24.70 per thousand, respectively) that differed more from the seawater POM than from river POM, demonstrating the dominance of terrestrial material in those carbon pools. Benthic invertebrates showed a wide range in delta(15)N (mean 4.30 per thousand to 9.77 per thousand ) and delta(13)C (mean -23.81 per thousand to -18.47 per thousand ), suggesting different trophic levels, diets and organic sources. Among the macroinvertebrates, the surface (mean delta(13)C -23.71 per thousand ) and subsurface (mean delta(13)C -23.81 per thousand ) deposit-feeding polychaetes were particularly (13)C depleted, indicating that their carbon was mainly derived from terrestrial material. In flatfish, delta(15)N (mean 9.42 to 10.93 per thousand ) and delta(13)C (mean -19.95 per thousand to -17.69 per thousand ) varied among species, indicating differences in food source and terrestrial POM use. A significant negative correlation was observed between the percentage by weight of polychaetes in the diet and the delta(13)C of flatfish white muscle. Solea solea (the main polychaete feeder) had the lowest mean delta(13)C, Arnoglossus laterna and Buglossidium luteum (crustacean, mollusc and polychaete feeders) had intermediate values, and Solea impar (mollusc feeder) and Citharus linguatula (crustacean and fish feeder) exhibited the highest delta(13)C. Two different benthic food webs were thus identified off the Rhone River, one based on marine planktonic carbon and the other on the terrestrial POM carried by the river. Deposit-feeding polychaetes were responsible for the main transfer of terrestrial POM to upper trophic levels, linking sole population dynamics to river runoff fluctuations.

Effects of chronic metal exposure and sediment organic matter on digestive absorption efficiency of cadmium by the deposit-feeding polychaete Capitella species I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Selck, H.; Forbes, V.E.; Decho, A.W.

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. Wormsmore » 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.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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 andmore » 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.« less

Unsegmented annelids? Possible origins of four lophotrochozoan worm taxa.

PubMed

Halanych, Kenneth M; Dahlgren, Thomas G; McHugh, Damhnait

2002-07-01

In traditional classification schemes, the Annelida consists of the Polychaeta and the Clitellata (the latter including the Oligochaeta and Hirudinida). However, recent analyses suggest that annelids are much more diverse than traditionally believed, and that polychaetes are paraphyletic. Specifically, some lesser-known taxa (previously regarded as separate phyla) appear to fall within the annelid radiation. Abundant molecular, developmental, and morphological data show that the Siboglinidae, which includes the formerly recognized Pogonophora and Vestimentifera, are derived annelids; recent data from the Elongation Factor-1α (EF-1α) gene also suggest that echiurids are of annelid ancestry. Further, the phylogenetic origins of two other lesser-known groups of marine worms, the Myzostomida and Sipuncula, have recently been called into question. Whereas some authors advocate annelid affinities, others argue that these taxa do not fall within the annelid radiation. With advances in our understanding of annelid phylogeny, our perceptions of body plan evolution within the Metazoa are changing. The evolution of segmentation probably is more plastic than traditionally believed. However, as our understanding of organismal evolution is being revised, we are also forced to reconsider the specific characters being examined. Should segmentation be considered a developmental process or an ontological endpoint?

Effects of Feeding Strategy, Sediment Characteristics, and Chemical Properties on Polychlorinated Biphenyl and Polybrominated Diphenyl Ether Bioaccumulation from Marine Sediments in Two Invertebrates.

PubMed

Frouin, H; Jackman, P; Dangerfield, N D; Ross, P S

2017-08-01

Shellfish and sediment invertebrates have been widely used to assess pollution trends over space and time in coastal environments around the world. However, few studies have compared the bioaccumulation potential of different test species over a range of sediment-contaminant concentrations and profiles. The bioavailability of sediment-related contaminants was evaluated using sediments collected from sites (n = 12) throughout the Salish Sea, British Columbia, Canada. Two benthic marine invertebrates-the Baltic clam Macoma balthica and the polychaete worm Neanthes arenaceodentata-were exposed for 28 days in a controlled environment to these field-collected coastal sediments. The congener-specific uptake of legacy polychlorinated biphenyls (PCBs) and emergent polybrominated diphenyl ethers (PBDEs) was determined using high-resolution gas chromatography/mass spectrometry in sediments and in invertebrates after the experimental exposure. The polychaete Neanthes accumulated lower concentrations of PCBs but higher concentrations of PBDEs. The present study indicates that differences in bioaccumulation between these two invertebrates shape the accumulation of PCB and PBDE congeners, reflect differences in feeding strategies, and reveal the physicochemical properties of the contaminants and sediment properties. Because biota-sediment accumulation factor values are often calculated for environmental monitoring or site-specific impact assessments, our results provide insight into potentially confounding factors and the need for caution when selecting indicator species for coastal marine pollution.

Trophic transfer and effects of DDT in male hornyhead turbot (Pleuronichthys verticalis) from Palos Verdes Superfund site, CA (USA) and comparisons to field monitoring.

PubMed

Crago, Jordan; Xu, Elvis Genbo; Kupsco, Allison; Jia, Fang; Mehinto, Alvine C; Lao, Wenjian; Maruya, Keith A; Gan, Jay; Schlenk, Daniel

2016-06-01

High concentrations of DDT and metabolites (ΣDDT) have been detected in sediment and the demersal flatfish hornyhead turbot (Pleuronichtys verticalis) collected from Palos Verdes (PV), California, USA, a site contaminated with over 100 metric tons of DDT throughout 1960s-70s. This study was conducted to assess the transfer of ΣDDT from PV-sediment into polychaetes (Neanthes arenaceodentata) and hornyhead turbot, and to investigate if the responses in turbots from two different laboratory exposures mimic those in turbots caught in PV (PV-turbot). Turbot fed PV-sediment-contaminated polychaete for 7 days had liver concentrations of ΣDDT similar to PV-turbot. After 28 days, ΣDDT also accumulated in livers of turbot gavaged with a ΣDDT mixture. In vitro cell bioassays indicated significant increases of 17β-estradiol equivalents (EEQ) in turbot bile extracts as compared to the control in the 7-day study. These responses corresponded to those measured in PV-fish. Glucocorticoid receptor (GR), anti-androgen receptor (anti-AR), estrogen receptor (ER) or aryl hydrocarbon receptor (AhR) activities were also observed in extracts of PV-sediment, and PV-sediment-exposed worm. Anti-AR, AhR and GR activities were significantly higher in PV-sediment than reference sediment (San Diego, SD). Higher transcripts of hepatic VTG, ERα and ERβ were found in PV-turbot than SD-turbot, but were unaltered in fish exposed to sediment-contaminated worms for the 7-day study. In contrast, liver extracts from the 28-day treatment of ΣDDT showed lower EEQ but similar hepatic VTG and ERβ transcripts relative to those of PV-turbot. These data indicated that trophic transfer of sediment-associated DDT in 7-day exposures corresponded to field measurements of DDT residues and in vitro ER bioactivities, but failed to mimic in vivo biological effects observed in field fish. In contrast, treatment with ΣDDT alone for 28 days mimicked in vivo biological effects of DDTs in PV fish, but did not correspond to liver concentrations or in vitro bioactivities. Copyright © 2016 Elsevier Ltd. All rights reserved.

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. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Indicators of sewage contamination in sediments beneath a deep-ocean dump site off New York

USGS Publications Warehouse

Bothner, Michael H.; Takada, H.; Knight, I.T.; Hill, R.T.; Butman, B.; Farrington, J.W.; Colwell, R.R.; Grassle, J. F.

1994-01-01

The world's largest discharge of municipal sewage sludge to surface waters of the deep sea has caused measurable changes in the concentration of sludge indicators in sea-floor sediments, in a spatial pattern which agrees with the predictions of a recent sludge deposition model. Silver, linear alkylbenzenes, coprostanol, and spores of the bacterium Clostridium perfringens, in bottom sediments and in near-bottom suspended sediment, provide evidence for rapid settling of a portion of discharged solids, accumulation on the sea floor, and biological mixing beneath the water sediment interface. Biological effects include an increase in 1989 of two species of benthic polychaete worm not abundant at the dump site before sludge dumping began in 1986. These changes in benthic ecology are attributed to the increased deposition of utilizable food in the form of sludge-derived organic matter.

Pollution biomarkers in two estuarine invertebrates, Nereis diversicolor and Scrobicularia plana, from a Marsh ecosystem in SW Spain.

PubMed

Solé, Montserrat; Kopecka-Pilarczyk, Justyna; Blasco, Julián

2009-04-01

The polychaete worm Nereis diversicolor and the clam Scrobicularia plana were collected from several sites, affected by different types of contamination, in a littoral enclosure in the SW Spain (Caño Sancti-Petri and Rio San Pedro). N. diversicolor was present in 6 sampling sites whereas S. plana in 4 of them. The aim of our study was to relate several pollution biomarkers to chemical sources (metals and organic pollutants e.g. PCB, PAH) in these species, thereby confirming their adequacy as sentinels for this habitat. The biomarkers surveyed in the two invertebrates were the activities of the antioxidant enzyme catalase (CAT), the phase II detoxifying enzyme glutathione S-transferase (GST) and the neurotoxicity marker acetylcholinesterase (AChE). Metallothionein (MT) levels were measured as a biomarker of exposure to metals. The results suggested a different response in the two sediment-dwelling organisms, the sediment-eating polychaete and the water-filtering clam, probably as a consequence of different contamination exposures. The results also suggested that samples from the "Caño Sancti-Petri" were exposed to biologically active compounds that altered some of their biochemical responses. Of all the biomarkers tested, AChE was the most sensitive one and N. diversicolor the potentially most robust sentinel in this ecosystem. In this low to moderately polluted environment, the biochemical approach better reflected temporal trends than site-related differences although it was also able to detect punctual chemical insults.

Articulated Wiwaxia from the Cambrian Stage 3 Xiaoshiba lagerstätte.

PubMed

Yang, Jie; Smith, Martin R; Lan, Tian; Hou, Jin-bo; Zhang, Xi-guang

2014-04-10

Wiwaxia is a bizarre metazoan that has been interpreted as a primitive mollusc and as a polychaete annelid worm. Extensive material from the Burgess Shale provides a detailed picture of its morphology and ontogeny, but the fossil record outside this lagerstätte is scarce, and complete wiwaxiids are particularly rare. Here we report small articulated specimens of Wiwaxia foliosa sp. nov. from the Xiaoshiba fauna (Cambrian Stage 3, Hongjingshao Formation, Kunming, south China). Although spines are absent, the fossils' sclerites - like those of W. corrugata - are symmetrically arranged in five distinct zones. They form rows across the body, and were individually added and shed throughout growth to retain an approximately symmetrical body shape. Their development pattern suggests a molluscan affinity. The basic body plan of wiwaxiids is fundamentally conserved across two continents through Cambrian Stages 3-5 - revealing morphological stasis in the wake of the Cambrian explosion.

Mineralogical gradients associated with alvinellids at deep-sea hydrothermal vents

NASA Astrophysics Data System (ADS)

Zbinden, Magali; Le Bris, Nadine; Compère, Philippe; Martinez, Isabelle; Guyot, François; Gaill, Françoise

2003-02-01

Alvinella pompejana and Alvinella caudata live in organic tubes on active sulphide chimney walls at deep-sea hydrothermal vents. These polychaete annelids are exposed to extreme thermal and chemical gradients and to intense mineral precipitation. This work points out that mineral particles associated with Pompeii worm ( A. pompejana and A. caudata) tubes constitute useful markers for evaluating the chemical characteristics of their micro-environment. The minerals associated with these worm tubes were analysed on samples recovered from an experimental alvinellid colony, at different locations in the vent fluid-seawater interface. Inhabited tubes from the most upper and lower parts of the colony were analysed by light and electron microscopies, X-ray microanalysis and X-ray diffraction. A change was observed from a Fe-Zn-S mineral assemblage to a Zn-S assemblage at the millimeter scale from the outer to the inner face of a tube. A similar gradient in proportions of minerals was observed at a decimeter scale from the lower to the upper part of the colony. The marcasite/pyrite ratio of iron disulphides also displays a steep decrease along the few millimeters adjacent to the external tube surface. The occurrence of these gradients indicates that the micro-environment within the tube differs from that outside the tube, and suggests that the tube wall acts as an efficient barrier to the external environment.

Shifting baselines in the Ems Dollard estuary: A comparison across three decades reveals changing benthic communities

NASA Astrophysics Data System (ADS)

Compton, Tanya J.; Holthuijsen, Sander; Mulder, Maarten; van Arkel, Maarten; Schaars, Loran Kleine; Koolhaas, Anita; Dekinga, Anne; ten Horn, Job; Luttikhuizen, Pieternella C.; van der Meer, Jaap; Piersma, Theunis; van der Veer, Henk W.

2017-09-01

At a time when there is a growing discussion about the natural state of estuaries, a comparison of macrozoobenthos communities from two surveys conducted 30 years apart in the Ems Dollard estuary, in the eastern Wadden Sea, The Netherlands, provides a unique opportunity to compare changes over time. As expected, our comparison revealed a gradient in species composition from land (the Dollard) to sea (the Outer Ems) at both points in time, with brackish species in the Dollard and more marine species in the Outer Ems (Wadden Sea). Total richness increased over time; however, this mainly reflected the immigration of new species and sampling differences. In the Dollard, total biomass declined over time, most likely reflecting de-eutrophication in this area. Strikingly, at the meeting point between the sea and the brackish Dollard, i.e. the Inner Ems, the community composition changed from one dominated by bivalves (1970s) to one dominated by worms (since 2009). This change involved a reduction in total biomass, mainly of Mya arenaria, and immigration of polychaete worms (Marenzellaria viridis and Alitta succinea). In the Outer Ems, an increase in total biomass was observed, associated with the recent successful recruitment of Cerastoderma edule. This comparison highlights that historical data provides useful insights at large spatial scales. However, a full understanding of the complex dynamics of estuaries requires an analysis of continuous long-term monitoring series.

Lipid remodelling in the reef-building honeycomb worm, Sabellaria alveolata, reflects acclimation and local adaptation to temperature

PubMed Central

Muir, Anna P.; Nunes, Flavia L. D.; Dubois, Stanislas F.; Pernet, Fabrice

2016-01-01

Acclimation and adaptation, which are key to species survival in a changing climate, can be observed in terms of membrane lipid composition. Remodelling membrane lipids, via homeoviscous adaptation (HVA), counteracts membrane dysfunction due to temperature in poikilotherms. In order to assess the potential for acclimation and adaptation in the honeycomb worm, Sabellaria alveolata, a reef-building polychaete that supports high biodiversity, we carried out common-garden experiments using individuals from along its latitudinal range. Individuals were exposed to a stepwise temperature increase from 15 °C to 25 °C and membrane lipid composition assessed. Our results suggest that S. alveolata was able to acclimate to higher temperatures, as observed by a decrease in unsaturation index and 20:5n-3. However, over the long-term at 25 °C, lipid composition patterns are not consistent with HVA expectations and suggest a stress response. Furthermore, unsaturation index of individuals from the two coldest sites were higher than those from the two warmest sites, with individuals from the thermally intermediate site being in-between, likely reflecting local adaptation to temperature. Therefore, lipid remodelling appears limited at the highest temperatures in S. alveolata, suggesting that individuals inhabiting warm environments may be close to their upper thermal tolerance limits and at risk in a changing climate. PMID:27762300

Metal interactions between the polychaete Branchipolynoe seepensis and the mussel Bathymodiolus azoricus from Mid-Atlantic-Ridge hydrothermal vent fields.

PubMed

Bebianno, Maria João; Cardoso, Cátia; Gomes, Tânia; Blasco, Julian; Santos, Ricardo Serrão; Colaço, Ana

2018-04-01

The vent blood-red commensal polynoid polychaete Branchipolynoe seepensis is commonly found in the pallial cavity of the vent mussel Bathymodiolus azoricus, the dominant bivalve species along the Mid-Atlantic-Ridge (MAR) and is known to be kleptoparasitic. Mussels were collected from three hydrothermal vent fields in the MAR: Menez Gwen (850 m depth, MG2, MG3 and MG4), Lucky Strike (1700 m depth, Montségur-MS and Eiffel Tower-ET) and Rainbow (2300 m depth). Polychaetes were absent in all Menez Gwen vent mussels, while the highest percentage was detected in mussels from Lucky Strike, where more than 70% of the mussels had at least one polychaete in their mantle cavity, followed by Rainbow with 33% of mussels with polychaetes. Total metal concentrations (Ag, Cd, Co, Cu, Fe, Mn, Ni and Zn) were determined in polychaetes whole body and in the mussel tissues (gills, digestive gland and mantle). To understand the possible metal interactions between symbiont and host, the activity of antioxidant defence (catalase (CAT), metallothioneins (MTs)), biotransformation enzymes (glutathione-s-transferases (GST)) activities and lipid peroxidation (LPO) were determined in polychaete whole soft tissues and in mussel tissues (gills, digestive gland and mantle). Metal concentrations in polychaetes and mussels tissues indicated that the accumulation patterns were species specific and also influenced by, and possibly dependent upon, the inter- and intra-variation of vent physico-chemistry between hydrothermal fields. Despite not detecting any strong correlations between metal and enzymes activities in polychaetes and mussels, when in presence of polychaetes, mussels presented less metal concentrations in the gills and digestive gland and lower activity of enzymatic biomarkers. This leads to infer that the polychaete plays a role on the detoxification process, and the interaction between the polychaete mussel association is probably an adaptation to metals concentrations at the vent sites. Copyright © 2018 Elsevier Ltd. All rights reserved.

Modelling the reworking effects of bioturbation on the incorporation of radionuclides into the sediment column: implications for the fate of particle-reactive radionuclides in Irish Sea sediments.

PubMed

Cournane, S; León Vintró, L; Mitchell, P I

2010-11-01

A microcosm laboratory experiment was conducted to determine the impact of biological reworking by the ragworm Nereis diversicolor on the redistribution of particle-bound radionuclides deposited at the sediment-water interface. Over the course of the 40-day experiment, as much as 35% of a (137)Cs-labelled particulate tracer deposited on the sediment surface was redistributed to depths of up to 11 cm by the polychaete. Three different reworking models were employed to model the profiles and quantify the biodiffusion and biotransport coefficients: a gallery-diffuser model, a continuous sub-surface egestion model and a biodiffusion model. Although the biodiffusion coefficients obtained for each model were quite similar, the continuous sub-surface egestion model provided the best fit to the data. The average biodiffusion coefficient, at 1.8 +/- 0.9 cm(2) y(-1), is in good agreement with the values quoted by other workers on the bioturbation effects of this polychaete species. The corresponding value for the biotransport coefficient was found to be 0.9 +/- 0.4 cm y(-1). The effects of non-local mixing were incorporated in a model to describe the temporal evolution of measured (99)Tc and (60)Co radionuclide sediment profiles in the eastern Irish Sea, influenced by radioactive waste discharged from the Sellafield reprocessing plant. Reworking conditions in the sediment column were simulated by considering an upper mixed layer, an exponentially decreasing diffusion coefficient, and appropriate biotransport coefficients to account for non-local mixing. The diffusion coefficients calculated from the (99)Tc and (60)Co cores were in the range 2-14 cm(2) y(-1), which are consistent with the values found by other workers in the same marine area, while the biotransport coefficients were similar to those obtained for a variety of macrobenthic organisms in controlled laboratories and field studies.

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.

Formation of microplastics by polychaetes (Marphysa sanguinea) inhabiting expanded polystyrene marine debris.

PubMed

Jang, Mi; Shim, Won Joon; Han, Gi Myung; Song, Young Kyoung; Hong, Sang Hee

2018-06-01

Fragmentation of large plastic debris into smaller particles results in increasing microplastic concentrations in the marine environment. In plastic debris fragmentation processes, the influence of biological factors remains largely unknown. This study investigated the fragmentation of expanded polystyrene (EPS) debris by polychaetes (Marphysa sanguinea) living on the debris. A large number of EPS particles (131 ± 131 particles/individual, 0.2-3.8 mm in length) were found in the digestive tracts of burrowing polychaetes living on EPS debris. To confirm the formation of microplastics by polychaetes and identify the quantity and morphology of produced microplastics, polychaetes were exposed to EPS blocks in filtered seawater under laboratory conditions. Polychaetes burrowed into the blocks and created numerous EPS microplastic particles, indicating that a single polychaete can produce hundreds of thousands of microplastic particles per year. These results reveal the potential role of marine organisms as microplastic producers in the marine environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of different diets on the dietary attractability and selectivity of Chinese shrimp, Fenneropenaeus chinensis

NASA Astrophysics Data System (ADS)

Huang, Guoqiang; Dong, Shuanglin; Wang, Fang

2005-01-01

Attractabilities of different diets and dietary selectivity of Chinese shrimp, Fenneropenaeus chinensis were studied through behavior observation and feeding experiment, respectively. The five diets used in the experiment are: Fish Flesh (FF), Shrimp Flesh (SF), Clam Foot (CF), Polychaete Worm (PW), and Formulated Diet (FD). No significant differences of attractability exist between any two different diets when every two natural diets or all five diets are provided simultaneously. On the other hand, significant differences of attractability exist between FD and every single natural diet when they are provided simultaneously. Results of behavioral observation indicate that natural diets are more attractive than FD. In feeding experiment, Chinese shrimp has distinct selectivity on different diets. It positively selects CF and PW, negatively selects FF and SF, and excludes FD absolutely. The results of the present studies indicate that the dietary selectivity of shrimp was based not only on the attractabilities of the diets, but also on the responses such as growth and food conversion.

Toxic effects of brominated indoles and phenols on zebrafish embryos.

PubMed

Kammann, U; Vobach, M; Wosniok, W

2006-07-01

Organobromine compounds in the marine environment have been the focus of growing attention in past years. In contrast to anthropogenic brominated flame retardants, other brominated compounds are produced naturally, e.g., by common polychaete worms and algae. Brominated phenols and indoles assumed to be of biogenic origin have been detected in water and sediment extracts from the German Bight. These substances as well as some of their isomers have been tested with the zebrafish embryo test and were found to cause lethal as well as nonlethal malformations. The zebrafish test was able to detect a log K(OW)-related toxicity for bromophenols, suggesting nonpolar narcosis as a major mode of action. Different effect patterns could be observed for brominated indoles and bromophenols. The comparison of effective concentrations in the zebrafish embryo test with the concentrations determined in water samples suggests the possibility that brominated indoles may affect early life stages of marine fish species in the North Sea.

Effects of bottom fishing on the benthic megafauna of Georges Bank

USGS Publications Warehouse

Collie, J.S.; Escanero, G.A.; Valentine, P.C.

1997-01-01

This study addresses ongoing concerns ever the effects of mobile fishing gear on benthic communities. Using side-scan sonar, bottom photographs and fishing records, we identified a set of disturbed and undisturbed sites on the gravel pavement area of northern Georges Bank in the northwest Atlantic. Replicate samples of the megofauna were collected with a 1 m Naturalists' dredge on 2 cruises in 1994. Compared with the disturbed sites, the undisturbed sites had higher numbers of organisms, biomass, species richness and species diversity; evenness was higher at the disturbed sites. Undisturbed sites were characterized by an abundance of bushy epifaunal taxa (bryozoans, hydroids, worm tubes) that provide a complex habitat for shrimps, polychaetes, brittle stars, mussels and small fish. Disturbed sites were dominated by larger, hard-shelled molluscs, and scavenging crabs and echinoderms. Many of the megafaunal species in our samples have also been identified in stomach contents of demersal fish on Georges Bank; the abundances of at feast some of these species were reduced at the disturbed sites.

Bioaccumulation and biotransformation of arsenic compounds in Hediste diversicolor (Muller 1776) after exposure to spiked sediments.

PubMed

Gaion, Andrea; Sartori, Davide; Scuderi, Alice; Fattorini, Daniele

2014-05-01

This study focused on the exposure of the common ragworm Hediste diversicolor (Müller 1776) to sediments enriched with different arsenic compounds, namely arsenate, dimethyl-arsinate, and arsenobetaine. Speciation analysis was carried out on both the spiked sediments and the exposed polychaetes in order to investigate H. diversicolor capability of arsenic bioaccumulation and biotransformation. Two levels of contamination (acute and moderate dose) were chosen for enriched sediments to investigate possible differences in the arsenic bioaccumulation patterns. The highest value of arsenic in tissues was reached after 15 days of exposure to dimethyl-arsinate (acute dose) spiked sediment (1,172 ± 176 μg/g). A significant increase was also obtained in worms exposed both to arsenate and arsenobetaine. Speciation analysis showed that trimethyl-arsine oxide was the predominant chemical form in tissues of H. diversicolor exposed to all the spiked sediments, confirming the importance of this intermediate in biological transformation of arsenic.

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.

Proteome Evolution of Deep-Sea Hydrothermal Vent Alvinellid Polychaetes Supports the Ancestry of Thermophily and Subsequent Adaptation to Cold in Some Lineages

PubMed Central

Fontanillas, Eric; Galzitskaya, Oxana V.; Lecompte, Odile; Lobanov, Mikhail Y.; Tanguy, Arnaud; Mary, Jean; Girguis, Peter R.; Hourdez, Stéphane

2017-01-01

Temperature, perhaps more than any other environmental factor, is likely to influence the evolution of all organisms. It is also a very interesting factor to understand how genomes are shaped by selection over evolutionary timescales, as it potentially affects the whole genome. Among thermophilic prokaryotes, temperature affects both codon usage and protein composition to increase the stability of the transcriptional/translational machinery, and the resulting proteins need to be functional at high temperatures. Among eukaryotes less is known about genome evolution, and the tube-dwelling worms of the family Alvinellidae represent an excellent opportunity to test hypotheses about the emergence of thermophily in ectothermic metazoans. The Alvinellidae are a group of worms that experience varying thermal regimes, presumably having evolved into these niches over evolutionary times. Here we analyzed 423 putative orthologous loci derived from 6 alvinellid species including the thermophilic Alvinella pompejana and Paralvinella sulfincola. This comparative approach allowed us to assess amino acid composition, codon usage, divergence, direction of residue changes and the strength of selection along the alvinellid phylogeny, and to design a new eukaryotic thermophilic criterion based on significant differences in the residue composition of proteins. Contrary to expectations, the alvinellid ancestor of all present-day species seems to have been thermophilic, a trait subsequently maintained by purifying selection in lineages that still inhabit higher temperature environments. In contrast, lineages currently living in colder habitats likely evolved under selective relaxation, with some degree of positive selection for low-temperature adaptation at the protein level. PMID:28082607

Diel variation in metabolism and ammonia excretion of Marphysa sanguinea (Polychaeta: Eunicidae)

NASA Astrophysics Data System (ADS)

Yang, Dazuo; Chen, Fudi; Zhou, Yibing; Xiu, Zhilong

2016-11-01

Polychaetes provide an excellent food resource for fish and represent the dominant zoobenthos in marine ecosystems. Diel variation in the rates of metabolism and ammonia-N excretion of Marphysa sanguinea were studied. The worms were grouped according to their wet body weight into small (S; 1.24±0.06 g), medium (M; 4.00±0.30 g), and large (L; 8.54±1.08 g) categories. Their weight-specific metabolic rates, based on aerobic respiration ( R), were measured at 16°C (±0.2°C) and classed as either routine ( R R) or standard ( R S) rates. Both respiration types decreased with increasing body weight. Respiration was described by R = a W b, where b was -0.400 9 and -0.532 0 for R R and R S, respectively. Diurnal changes in R S for each group was relatively flat, with a slightly increasing trend with time, but was relatively stable as a whole. R R of the diurnal variation of worms was higher than R S, but both had similar overall trends. The peak values of specific dynamic action (SDA) ( R SDA) in the S, M, and L groups were 2.704, 1.149, and 0.682 mg/(g•h), respectively. The durations of SDA were 13, 6, and 6 h, respectively and the energy expenditures of SDA were 377.98, 117.34, and 74.94 J/g, respectively. These data indicate that the metabolic rates were higher in smaller individuals, which is advantageous for their rapid growth.

Food web flows through a sub-arctic deep-sea benthic community

NASA Astrophysics Data System (ADS)

Gontikaki, E.; van Oevelen, D.; Soetaert, K.; Witte, U.

2011-11-01

The benthic food web of the deep Faroe-Shetland Channel (FSC) was modelled by using the linear inverse modelling methodology. The reconstruction of carbon pathways by inverse analysis was based on benthic oxygen uptake rates, biomass data and transfer of labile carbon through the food web as revealed by a pulse-chase experiment. Carbon deposition was estimated at 2.2 mmol C m -2 d -1. Approximately 69% of the deposited carbon was respired by the benthic community with bacteria being responsible for 70% of the total respiration. The major fraction of the labile detritus flux was recycled within the microbial loop leaving merely 2% of the deposited labile phytodetritus available for metazoan consumption. Bacteria assimilated carbon at high efficiency (0.55) but only 24% of bacterial production was grazed by metazoans; the remaining returned to the dissolved organic matter pool due to viral lysis. Refractory detritus was the basal food resource for nematodes covering ∼99% of their carbon requirements. On the contrary, macrofauna seemed to obtain the major part of their metabolic needs from bacteria (49% of macrofaunal consumption). Labile detritus transfer was well-constrained, based on the data from the pulse-chase experiment, but appeared to be of limited importance to the diet of the examined benthic organisms (<1% and 5% of carbon requirements of nematodes and macrofauna respectively). Predation on nematodes was generally low with the exception of sub-surface deposit-feeding polychaetes that obtained 35% of their energy requirements from nematode ingestion. Carnivorous polychaetes also covered 35% of their carbon demand through predation although the preferred prey, in this case, was other macrofaunal animals rather than nematodes. Bacteria and detritus contributed 53% and 12% to the total carbon ingestion of carnivorous polychaetes suggesting a high degree of omnivory among higher consumers in the FSC benthic food web. Overall, this study provided a unique insight into the functioning of a deep-sea benthic community and demonstrated how conventional data can be exploited further when combined with state-of-the-art modelling approaches.

A temporal analysis on the dynamics of deep-sea macrofauna: Influence of environmental variability off Catalonia coasts (western Mediterranean)

NASA Astrophysics Data System (ADS)

Mamouridis, V.; Cartes, J. E.; Parra, S.; Fanelli, E.; Saiz Salinas, J. I.

2011-04-01

A seasonal analysis of deep-sea infauna (macrobenthos) based on quantitative sampling was conducted over the Catalan Sea slope, within the Besòs canyon (at ˜550-600 m) and on its adjacent slope (at 800 m). Both sites were sampled in February, April, June-July and October 2007. Environmental variables influencing faunal distribution were also recorded in the sediment and sediment/water interface. Dynamics of macrobenthos at the two stations showed differences in biomass/abundance patterns and trophic structures. Biomass was higher inside the Besòs canyon than on the adjacent slope. The community was mostly dominated by surface-deposit feeding polychaetes (Ampharetidae, Paraonidae, Flabelligeridae) and crustaceans (amphipods such as Carangoliopsis spinulosa and Harpinia spp.) inside the canyon, while subsurface deposit feeders (mainly the sipunculan Onchnesoma steenstrupii) were dominant over the adjacent slope. The taxonomic composition in the suprabenthic assemblages of polychaetes, collected on the adjacent slope by a suprabenthic sledge, was clearly different from that collected by the box-corer. The suprabenthic assemblage was dominated by carnivorous forms (mainly Harmothoe sp. and Nephthys spp.) and linked to higher near-bottom turbidity. Inside Besòs a clear temporal succession of species was related to both food availability and quality and the proliferation of opportunistic species was consistent with higher variability in food sources (TOC, C/N, δ 13C) in comparison to adjacent slope. This was likely caused by a greater influence of terrigenous inputs from river discharges. Inside the canyon, Capitellidae, Spionidae and Flabelligeridae, in general considered as deposit feeders, were more abundant in June-July coinciding with a clear signal of terrigenous carbon (depleted δ 13C, high C/N) in the sediments. By contrast, during October and under conditions of high water turbidity and increases of TOM, carnivorous polychaetes (Glyceridae, Onuphidae) increased. Total macrobenthos biomass found over Catalonian slopes were higher than that found in the neighboring Toulon canyon, probably because the two canyons are influenced by different river inputs, connected with distinct terrigenous sources.

Pearls in the ribbed mussel Aulacomya atra caused by polydorin polychaetes (Spionidae) infestation.

PubMed

Diez, M E; Vázquez, N; Cremonte, F

2016-10-01

Aulacomya atra populations of the San Jose gulf, Northern Patagonia, Southwestern Atlantic Ocean, are infested by two polydorin species, Polydora rickettsi and Dipolydora cf. giardi. The infestation by these boring polychaetes causes the formation of pearls which is evidenced by the presence of capsules containing polydorin tissue debris and the elemental composition of organic material inside the pearls. Moreover, a positive relationship between the abundance of perforations of polydorin polychaetes and abundance of pearls was found by applying generalized lineal model analysis. These results constitute the first evidence of pearls formation due to infestation by polychaete. Copyright © 2016 Elsevier Inc. All rights reserved.

Integrating a DNA barcoding project with an ecological survey: a case study on temperate intertidal polychaete communities in Qingdao, China

NASA Astrophysics Data System (ADS)

Zhou, Hong; Zhang, Zhinan; Chen, Haiyan; Sun, Renhua; Wang, Hui; Guo, Lei; Pan, Haijian

2010-07-01

In this study, we integrated a DNA barcoding project with an ecological survey on intertidal polychaete communities and investigated the utility of CO1 gene sequence as a DNA barcode for the classification of the intertidal polychaetes. Using 16S rDNA as a complementary marker and combining morphological and ecological characterization, some of dominant and common polychaete species from Chinese coasts were assessed for their taxonomic status. We obtained 22 haplotype gene sequences of 13 taxa, including 10 CO1 sequences and 12 16S rDNA sequences. Based on intra- and inter-specific distances, we built phylogenetic trees using the neighbor-joining method. Our study suggested that the mitochondrial CO1 gene was a valid DNA barcoding marker for species identification in polychaetes, but other genes, such as 16S rDNA, could be used as a complementary genetic marker. For more accurate species identification and effective testing of species hypothesis, DNA barcoding should be incorporated with morphological, ecological, biogeographical, and phylogenetic information. The application of DNA barcoding and molecular identification in the ecological survey on the intertidal polychaete communities demonstrated the feasibility of integrating DNA taxonomy and ecology.

Macrobioerosion in Porites corals in subtropical northern South China Sea: a limiting factor for high-latitude reef framework development

NASA Astrophysics Data System (ADS)

Chen, Tianran; Li, Shu; Yu, Kefu

2013-03-01

Bioerosion is an important limiting factor in carbonate accretion and reef framework development; however, few studies have quantified the direct impact of macroborers on high-latitude coral communities, which are viewed as potential refuge during a period of global warming. In this study, internal macrobioerosion of Porites corals was examined at Daya Bay, subtropical northern South China Sea. The principal borers were the bivalve Lithophaga spp. and the sponges Cliona spp. and Cliothosa spp. (≥80 %), while sipunculid and polychaete worms and barnacles accounted for small amounts of bioerosion (≤20 %). Porites corals were heavily bioeroded in areas impacted by aquacultural and urban activities (10.34-27.55 %) compared with corals in relatively unpolluted areas (2.18-6.76 %). High levels of bioerosion, especially boring bivalve infestation, significantly weaken the corals and increase their susceptibility to dislodgement and fragmentation in typhoons, limiting accumulation of limestone framework. This study implies that carbonate accretion and reef development for high-latitude coral communities may be limited in future high-CO2 and eutrophication-stressed environments.

Feeding ecology and trophic relationships of fish species in the lower Guadiana River Estuary and Castro Marim e Vila Real de Santo António Salt Marsh

NASA Astrophysics Data System (ADS)

Sá, Rita; Bexiga, Constança; Veiga, Pedro; Vieira, Lina; Erzini, Karim

2006-10-01

In this study we analyze the feeding ecology and trophic relationships of some of the main fish species (Soleidae, Moronidae, Mullidae, Sparidae, Mugilidae, and Batrachoididae) of the lower Estuary of the Guadiana River and the Castro Marim e Vila Real de Santo António Salt Marsh. We examined the stomachs of 1415 fish caught monthly between September 2000 and August 2001. Feeding indices and coefficients were determined and used along with the results of multivariate analysis to develop diagrams of trophic interactions (food webs). Results show that these species are largely opportunistic predators. The most important prey items are amphipods, gobies (Gobiidae), shrimps ( Palaemon serratus and Crangon crangon), and polychaete worms. The lower Estuary and associated salt marshes are important nurseries and feeding grounds for the species studied. In this area, it is therefore important to monitor the effects of changes in river runoff, nutrient input, and temperature that result from construction of the Alqueva Dam upstream.

Toxicity of fluoranthene to Daphnia magna, Hyalella azteca, Chironomus tentans, and Stylaria lacustris in water-only and whole sediment exposures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suedel, B.C.; Rodgers, J.H. Jr.

1996-07-01

Fluoranthene is a polycyclic aromatic hydrocarbon (PAH) with a hydrophobic nature (water solubility = 265 {mu}g/L; U.S. EPA 1980) and a propensity to sorb to sediments. Fluoranthene has a K{sub oc} of 4.65, an intermediate value for PAHs. Fluoranthene can be toxic to some aquatic organisms at concentrations lower than its aqueous solubility. Therefore, desorption from sediments could produce aqueous concentrations that are harmful to aquatic organisms. Very few studies have examined the toxicity of fluoranthene to freshwater organisms. Data for other PAHs show that crustaceans are the most sensitive species, followed by polychaete worms and fish. Effects of fluoranthene-amendedmore » sediments on selected marine benthic organisms were examined. The objectives of this research were to (1) determine the relative sensitivities of Daphnia magna Straus, Hyalella azteca Saussure, Chironomus tentans Fabricius, and Stylaria lacustris Linnaeus in 48-hr and 10-d aqueous phase exposures to fluoranthene; and (2) determine the relative responses of these organisms in 10-d fluoranthene-amended sediment exposures. 12 refs., 3 tabs.« less

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

Foraging Behaviour Patterns of Four Sympatric Demersal Fishes

NASA Astrophysics Data System (ADS)

Labropoulou, M.; Papadopoulou-Smith, K.-N.

1999-08-01

The trophic relationships of four sympatric demersal fish species (Mullus barbatus, Mullus surmuletus, Pagrus pagrus and Gobius niger) which dominate the shallow coastal areas (25-30 m) of Iraklion Bay (S Aegean, NE Mediterranean) were investigated from samples collected on a monthly basis (August 1990-August 1992). Stomach content analysis revealed that all four species were carnivorous, feeding mainly on benthic invertebrates. Although these species displayed different feeding modes based on principal prey type utilization, they all consumed a considerable number of polychaetes. In order to understand any underlying patterns of predation on polychaetes, prey items were identified to the lowest possible taxonomic level. The polychaete species were further classified into groups according to their microhabitat (surface or burrowing) and feeding (feeding mode, motility and morphology) guilds. Comparisons of the feeding habits were made using the percentage contribution by number of each prey species in the diet of the predators. Similarities in the diets between the fish species were calculated and cluster analysis was used to describe interspecific variations in food selection, concerning polychaetes. The predatory preferences of each fish species were related to the microhabitat distribution of prey species in the sediment. The differential exploitation of polychaete species was a good indicator of disparate foraging behaviour among the fish species examined, since it reflects a transition from a non-selective to a specialized feeding method. The effects of predator size and morphology of feeding apparatus and the availability of polychaete species in the environment are also discussed to explain the differential exploitation of polychaetes exhibited by the fish.

Heavy metal contamination from historic mining in upland soil and estuarine sediments of Egypt Bay, Maine, USA

NASA Astrophysics Data System (ADS)

Osher, L. J.; Leclerc, L.; Wiersma, G. B.; Hess, C. T.; Guiseppe, V. E.

2006-10-01

Concentrations of Cd, Cu, Pb and Zn in sediments of Egypt Bay in Hancock County, Maine, are elevated above background levels. The source of the contamination is Cu mining that occurred in the uplands adjacent to Egypt Stream between 1877 and 1885. Egypt Stream is a tributary to Egypt Bay. Egypt Bay is part of the Taunton Bay estuary system. The Hagan Mine was one of the mines extracting metals from the sulfide deposits in Downeast Maine north of Penobscot Bay. Metal concentrations were determined using ICP-AES after sample digestion with nitric acid. Soil collected from the coarse textured mine tailings pile contained elevated concentrations of Cd, Cu, Pb and Zn, but the majority of the surface soils at the Hagan Mine site were not contaminated. Estuary sediments from the surface to 100 cm depth were collected in four locations within Egypt Bay. Below 40 cm, metal concentrations in sediments were similar to those in uncontaminated upland soils. Metal concentrations in the estuary sediments between the surface and 26 cm were above background levels. According to 210Pb dating, the sediment at 26-34 cm depth was likely to have been deposited at the time the historic mines were in operation. Concentrations of Cd, Cu, Pb, and Zn in sediment from the 32-34 cm depth interval are similar to concentrations in the upland soil sample from the mine tailings pile. Elevated Pb concentrations in sediments from the surface to 24 cm are from atmospheric Pb deposition from anthropogenic sources. Sediment in the top 10 cm of the estuary has been mixed both by the polychaete worm Nereis virens and by those harvesting the worms for sale as fish bait.

Temporal and spatial variations in the polychaete (Annelida) populations on the upper continental slope of the northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Qu, Fangyuan; Wang, Yuning; Rowe, Gilbert T.

2017-01-01

Polychaete worms (Annelida), the dominant macrofaunal taxon in most fine-grained marine sediments, were sampled in 1983-85 and then again in 2000-02 at nine locations at depths of 324-1454 m. on the upper continental slope of the northern Gulf of Mexico (GoM). The assemblages exhibited relative stability in abundance and diversity, but fell into six separate groups of species (>35% similarity) that were related to time-of-sampling, location, depth. This depth gradient experiences an increase in oxygen from 2.5 to 4.5 ml/L, a six degree decrease in temperature (10-12° down to 4 °C) and a decline of 30-37 mg C m-2 day-1 down to 7 mg C m-2 day-1 in estimates of the particulate organic carbon (POC) input to the sea floor, but these steep gradients had secondary effects on species turnover or depth-related zonation (Beta diversity). The species composition of four of the six groups was separated on the basis of sampling between 1983-85 and 2000-02 as opposed to depth or location. The species composition of the two groups on the eastern transect was different from the western sites and the two eastern groups differed in species composition from each other between 1983-85 and 2000-02. The two groups of species at the three deeper sites to the west (864-1410 m) were also separated on the basis of time-of-sampling but the group of species located at the three shallow locations (324-625 m) was not; it was a mixture of the two sampling periods. Significantly higher densities (p<0.05) in April 1984, on the eastern transect, suggest that seasonal recruitment may have occurred but the higher densities were attributed to only two species.

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. 

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.

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.

Bioerosion and encrustation: Evidences from the Middle ‒ Upper Jurassic of central Saudi Arabia

NASA Astrophysics Data System (ADS)

El-Hedeny, Magdy; El-Sabbagh, Ahmed; Al Farraj, Saleh

2017-10-01

The Middle ‒ Upper Jurassic hard substrates of central Saudi Arabia displayed considerable signs of bioerosion and encrustations. They include organic (oysters, other bivalves, gastropods, corals and brachiopods) and an inorganic carbonate hardground that marks the boundary between the Middle Jurassic Tuwaiq Mountain Limestone and the Upper Jurassic Hanifa Formation. Traces of bioerosion in organic substrates include seven ichnotaxa produced by bivalves (Gastrochaenolites Leymerie, 1842), polychaete annelids (Trypanites Mägdefrau, 1932; MaeandropolydoraVoigt, 1965 and CaulostrepsisClarke, 1908), sponges (Entobia Bronn, 1837), acrothoracican cirripedes (Rogerella Saint-Seine, 1951), gastropods (Oichnus Bromley, 1981) and probable ?Centrichnus cf. eccentricus. The encrusting epifauna on these substrates consist of several organisms, including oysters, serpulid worms, corals and foraminifera. In contrast, the carbonate hardground was only bioeroded by Gastrochaenolite, Trypanites and Entobia. Epibionts on this hardground include ;Liostrea Douvillé, 1904-type; oysters, Nanogyra nana Sowerby, 1822 and serpulids. In general, bioerosion and encrustation are less diversified in hardground than in organic substrates, indicating a long time of exposition of organic substrates with slow to moderate rate of deposition in a restricted marine environment. Both organic and inorganic commuinities are correlated with those of other equatorial, subtropical and temperate equivalents.

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.

Comprehensive Assessment of Marine Coatings in the Laboratory and Field

DTIC Science & Technology

2015-03-27

basal plate morphology and minimum size requirements. Only barnacles occurring at least 5 mm from the edges of the coupon were tested. Other...Incipient Fouling Calcareous Polychaetes | Sedimentan/ Polychaetes Solitary Tunicate | Sponges |Scuzz & & & & & Figure 7. Average

Sexual Satellites, Moonlight and the Nuptial Dances of Worms: the Influence of the Moon on the Reproduction of Marine Animals

NASA Astrophysics Data System (ADS)

Bentley, M. G.; Olive, P. J. W.; Last, K.

The evidence that the moon has a profound effect on the timing of reproductive activities of marine animals is compelling. Some moon phase related spawning events are revealed by the constant phase relationship between the timing of ``once per year'' spawning events and the lunar phase as in the highly synchronised breeding of the palolo worm Palola viridis and the Japanese crinoid Comanthus japonicus In other cases there is a repeated lunar cycle of reproductive activity and again the marine worms provide many good examples. The breeding of the palolo worm involves the highly synchronised release of what are in effect detached sexual satellites and the timing of this has annual (solar year), lunar, daily and tidal rhythm components. In a similar way, the onset of sexual maturation and participation in the nuptial dance of Platynereis dumerilli has strong lunar components. Sexual reproduction is the culmination of a process of sexual maturation that takes many months for completion and the mechanisms by which moon phase relationships are imposed on this process must have been selected for by mechanisms relating to reproductive success. The polychaetes provide excellent models for investigation of both the selective advantage and the physiological processes involved in reproductive synchrony. We have recently shown that the spawning of the lugworm Arenicola marina has lunar components and we conclude that an interaction between solar and lunar signals is widespread in the timing of reproduction in marine animals. Carl Hauenschild was the first to demonstrate the existence of a free-running circa-lunar rhythm in marine animals using captive populations of Platynereis dumerilli His experiments also provided clear evidence for the influence of moonlight (light at night) as the zeitgeber for this rhythm. This implies a high level of sensitivity to light, and the operation of appropriate endogenous biological rhythms. Using Nereis virens we have demonstrated a high level of sensitivity to low intensity solar light signals in relation to rhythmic processes with the properties similar to the circadian and photoperiodic mechanisms of terrestrial organisms. The spawning of N. virens is also believed to have lunar components reflecting the complex influences of the sun and the moon in the marine domain, where influences of the moon and sun are more equal. We suggest that evolution of biological rhythmicity that can be entrained to either lunar or solar systems arose in the marine domain. Recent advances in understanding the molecular components of the circadian clock system suggest that a search for a common molecular mechanism for both lunar and solar related biological rhythms in marine organisms might be very fruitful.

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 labelled glycine. Possible mechanisms for this enrichment include accumulation through inclusion in tissues with long residence times, preferential preservation (i.e. selection against) during metabolism, production from other labelled amino acids during varied metabolic processes, and accumulation in refractory by-products of secondary bacterial production. Overall, similarities were observed between amino-acid decay patterns in faunated microcosms, afaunal controls, and those previously reported in marine sediments. Thus, while polychaete gut passage did produce compound-selective accumulation and losses of certain amino acids in polychaete tissues and faecal matter, the impact of polychaete gut passage on sediment organic geochemistry was difficult to deconvolve from microbial decay. Despite processing large volumes of organic matter, polychaetes may not have distinctive influence on sediment compositions, possibly because metabolic processes concerning amino acids may be broadly similar across a wide range of organisms.

Growth and survival of three marine invertebrate species in sediments from the Hudson-Raritan estuary, New York

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rice, C.A.; Plesha, P.D.; Casillas, E.

1995-11-01

Sediments in the Hudson-Raritan estuary are known to contain high concentrations of anthropogenic contaminants, and marine organisms from this region exhibit numerous contaminant-related effects. To assess the pattern of sediment toxicity in depositional areas of this region, and to compare lethal and sublethal end points for different bioassay organisms, three benthic marine invertebrate species were exposed to sediments from 17 sites in the Hudson-Raritan estuary. Growth and mortality of the polychaete Armandia brevis and the sand dollar Dendraster excentricus were measured in all 17 sediments, while mortality and reburial ability of the amphipod Rhepoxinius abronius were assessed in nine sediments.more » Growth of polychaetes was determined by measuring the difference in weight after a 20-d exposure, whereas growth of sand dollars was assessed by measuring the difference in length and weight after a 28-d exposure. Amphipod mortality and reburial tests were conducted using the standard 10-d sediment bioassay. Significant growth reduction of polychaetes and sand dollars occurred in 11 of 17, and 3 of 17 sediments, respectively. Polychaete weight and sand dollar length correlated inversely and significantly with total sediment concentration of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and some selected elements. In contrast, significant mortality of polychaetes and amphipods occurred in 1 of 17 and 2 of 9 sediments, respectively, and impaired reburial ability of amphipods was not observed. Results of this study demonstrate that sediment contamination at depositional sites with the Hudson-Raritan estuary has potential to cause deleterious biological effects in indigenous benthic organisms. In addition, sublethal growth bioassays using polychaetes and sand dollars appear to be more sensitive in measuring the effects of sediment contamination than does the mortality-based bioassay using the amphipod Rhepoxinius abronius.« less

Distribution and abundance of the polychaete, Manayunkia speciosa Leidy, in western Lake Erie

USGS Publications Warehouse

Hiltunen, Jarl K.

1965-01-01

The abundance and distribution of the freshwater polychaete, Manayunkia speciosa, in 1961, are described for western Lake Erie. Previous records reveal that the species has either been generally overlooked or presently its numbers have greatly increased in the area considered.

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.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Uptake, metabolism and sub-lethal effects of BDE-47 in two estuarine invertebrates with different trophic positions.

PubMed

Díaz-Jaramillo, M; Miglioranza, K S B; Gonzalez, M; Barón, E; Monserrat, J M; Eljarrat, E; Barceló, D

2016-06-01

Two microcosm types -sediment-biota and biota-biota- were constructed to simulate different pathways of BDE-47 uptake, metabolism and oxidative stress effects in two key estuarine invertebrates (polychaete Laeonereis acuta and crab Cyrtograpsus angulatus). In the sediment-biota experiment, both species were exposed to spiked sediments; an environmentally reported and a high concentration of BDE-47 for 2 weeks. In the biota-biota experiment, crabs were fed with polychaetes pre-exposed to BDE-47 in the sediment-biota experiment. The sediment-biota experiment first revealed that polychaetes significantly accumulated BDE-47 (biota-sediment accumulation factor >2; p < 0.05) to a much greater extent than the crab organs (muscle, hepatopancreas, gills) at both sediment concentrations. For oxidative stress responses, polychaete and crab tissues exposed to spiked sediment showed a significant increase (p < 0.05) of only glutathione S-transferase (GST) activity with respect to controls in both BDE-47 concentrations. No lipid peroxidation (TBARS) or total antioxidant capacity (ACAP) changes were evident in the species or organs exposed to either BDE-47 sediment concentration. The biota-biota experiment showed that feeding crabs with pre-exposed polychaetes caused BDE-47 accumulation in organs as well as significant amounts of BDE-47 eliminated through feces (p < 0.05). Unlike the sediment-biota exposure, crabs fed with pre-exposed BDE-47 polychaetes showed the most conspicuous oxidative stress responses. Significant changes in GST and ACAP in both hepatopancreas and gills, in addition to enhanced TBARS levels in the hepatopancreas with respect to controls (p < 0.05), revealed that BDE-47 assimilated by invertebrates represents a potential source of toxicity to their predators. No methoxylated metabolites (MeO-PBDEs) were detected during BDE-47 metabolism in the invertebrates in either of the two different exposure types. In contrast, hydroxylated metabolites (OH-PBDEs) were detected in polychaetes and crab organs/feces in both experiments. Our results demonstrate that PBDE hydroxylation is one of the main biotransformation routes of BDE-47 in estuarine animals, which could be associated with the oxidative stress responses found. Copyright © 2016 Elsevier Ltd. All rights reserved.

Population subdivision of hydrothermal vent polychaete Alvinella pompejana across equatorial and Easter Microplate boundaries.

PubMed

Jang, Sook-Jin; Park, Eunji; Lee, Won-Kyung; Johnson, Shannon B; Vrijenhoek, Robert C; Won, Yong-Jin

2016-10-28

The Equator and Easter Microplate regions of the eastern Pacific Ocean exhibit geomorphological and hydrological features that create barriers to dispersal for a number of animals associated with deep-sea hydrothermal vent habitats. This study examined effects of these boundaries on geographical subdivision of the vent polychaete Alvinella pompejana. DNA sequences from one mitochondrial and eleven nuclear genes were examined in samples collected from ten vent localities that comprise the species' known range from 23°N latitude on the East Pacific Rise to 38°S latitude on the Pacific Antarctic Ridge. Multi-locus genotypes inferred from these sequences clustered the individual worms into three metapopulation segments - the northern East Pacific Rise (NEPR), southern East Pacific Rise (SEPR), and northeastern Pacific Antarctic Ridge (PAR) - separated by the Equator and Easter Microplate boundaries. Genetic diversity estimators were negatively correlated with tectonic spreading rates. Application of the isolation-with-migration (IMa2) model provided information about divergence times and demographic parameters. The PAR and NEPR metapopulation segments were estimated to have split roughly 4.20 million years ago (Mya) (2.42-33.42 Mya, 95 % highest posterior density, (HPD)), followed by splitting of the SEPR and NEPR segments about 0.79 Mya (0.07-6.67 Mya, 95 % HPD). Estimates of gene flow between the neighboring regions were mostly low (2 Nm < 1). Estimates of effective population size decreased with southern latitudes: NEPR > SEPR > PAR. Highly effective dispersal capabilities allow A. pompejana to overcome the temporal instability and intermittent distribution of active hydrothermal vents in the eastern Pacific Ocean. Consequently, the species exhibits very high levels of genetic diversity compared with many co-distributed vent annelids and mollusks. Nonetheless, its levels of genetic diversity in partially isolated populations are inversely correlated with tectonic spreading rates. As for many other vent taxa, this pioneering colonizer is similarly affected by local rates of habitat turnover and by major dispersal filters associated with the Equator and the Easter Microplate region.

Elucidating the life cycle of Marteilia sydneyi, the aetiological agent of QX disease in the Sydney rock oyster (Saccostrea glomerata).

PubMed

Adlard, Robert D; Nolan, Matthew J

2015-05-01

Marteilia sydneyi (Phylum Paramyxea, Class Marteiliidea, Order Marteiliida) (the causative agent of QX disease) is recognised as the most severe parasite to infect Saccostrea glomerata, the Sydney rock oyster, on the east coast of Australia. Despite its potential impact on industry (>95% mortality), research towards lessening these effects has been hindered by the lack of an experimental laboratory model of infection as a consequence of our incomplete understanding of the life cycle of this parasite. Here, we explored the presence of this parasite in hosts other than a bivalve mollusc from two study sites on the Hawkesbury River, New South Wales, Australia. We employed PCR-based in situ hybridisation and sequence analysis of a portion of the first internal transcribed spacer of rDNA in an attempt to detect M. sydneyi DNA in 21 species of polychaete worm. Marteilia DNA was detected in 6% of 1247 samples examined by PCR; the analysis of all amplicons defined one distinct sequence type for first internal transcribed spacer, representing M. sydneyi. Of the polychaete operational taxonomic units test-positive in PCR, we examined 116 samples via in situ hybridisation DNA probe staining and identified M. sydneyi DNA in the epithelium of the intestine of two specimens of Nephtys australiensis. Two differing morphological forms were identified: a 'primordial' cell that contained a well-defined nucleus but had little differentiation in the cytoplasm, and a 'plasmodial' cell that showed an apparent syncytial structure. This finding represents the first known record of the identification of M. sydneyi being parasitic in an organism other than an oyster, and only the third record of any species of Marteilia identified from non-molluscan hosts. Future work aims at determining if N. australiensis and S. glomerata are the only hosts in the life cycle of this paramyxean, and the development of experimental models to aid the production of QX disease-resistant oysters. Copyright © 2015 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

DIVERGENCE BETWEEN POPULATIONS OF A MONOGAMOUS POLYCHAETE WITH MALE PARENTAL CARE: PREMATING ISOLATION AND CHROMOSOME VARIATION

EPA Science Inventory

Low dispersal and sexual selection are characteristic of the coastal polychaete Nereis acuminata Ehlers 1868 [also known as Nereis arenaceodentata Moore 1903 and Nereis (Neanthes) caudata elle Chiaje 1841]. e assessed levels of premating isolation between populations of this poly...

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...

The influence of salinity on the effects of Multi-walled carbon nanotubes on polychaetes.

PubMed

De Marchi, Lucia; Neto, Victor; Pretti, Carlo; Figueira, Etelvina; Chiellini, Federica; Morelli, Andrea; Soares, Amadeu M V M; Freitas, Rosa

2018-06-05

Salinity shifts in estuarine and coastal areas are becoming a topic of concern and are one of the main factors influencing nanoparticles behaviour in the environment. For this reason, the impacts of multi-walled carbon nanotubes (MWCNTs) under different seawater salinity conditions were evaluated on the common ragworm Hediste diversicolor, a polychaete species widely used as bioindicator of estuarine environmental quality. An innovative method to assess the presence of MWCNT aggregates in the sediments was used for the first time. Biomarkers approach was used to evaluate the metabolic capacity, oxidative status and neurotoxicity of polychaetes after long-term exposure. The results revealed an alteration of energy-related responses in contaminated polychaetes under both salinity conditions, resulting in an increase of metabolism and expenditure of their energy reserves (lower glycogen and protein contents). Moreover, a concentration-dependent toxicity (higher lipid peroxidation, lower ratio between reduced and oxidized glutathione and activation of antioxidant defences and biotransformation mechanisms) was observed in H. diversicolor, especially when exposed to low salinity. Additionally, neurotoxicity was observed by inhibition of Cholinesterases activity in organisms exposed to MWCNTs at both salinities.

Polychaete functional diversity in shallow habitats: Shelter from the storm

NASA Astrophysics Data System (ADS)

Wouters, Julia M.; Gusmao, Joao B.; Mattos, Gustavo; Lana, Paulo

2018-05-01

Innovative approaches are needed to help understanding how species diversity is related to the latitudinal gradient at large or small scales. We have applied a novel approach, by combining morphological and biological traits, to assess the relative importance of the large scale latitudinal gradient and regional morphodynamic drivers in shaping the functional diversity of polychaete assemblages in shallow water habitats, from exposed to estuarine sandy beaches. We used literature data on polychaetes from beaches along the southern and southeastern Brazilian coast together with data on beach types, slope, grain size, temperature, salinity, and chlorophyll a concentration. Generalized linear models on the FDis index for functional diversity calculated for each site and a combined RLQ and fourth-corner analysis were used to investigate relationships between functional traits and environmental variables. Functional diversity was not related to the latitudinal gradient but negatively correlated with grain size and beach slope. Functional diversity was highest in flat beaches with small grain size, little wave exposure and enhanced primary production, indicating that small scale morphodynamic conditions are the primary drivers of polychaete functional diversity.

Characterizing lesions in corals from American Samoa

NASA Astrophysics Data System (ADS)

Work, T. M.; Rameyer, R. A.

2005-11-01

The study of coral disease has suffered from an absence of systematic approaches that are commonly used to determine causes of diseases in animals. There is a critical need to develop a standardized and portable nomenclature for coral lesions in the field and to incorporate more commonly available biomedical tools in coral disease surveys to determine the potential causes of lesions in corals. We characterized lesions in corals from American Samoa based on gross and microscopic morphology and classified them as discoloration, growth anomalies, or tissue loss. The most common microscopic finding in corals manifesting discoloration was the depletion of zooxanthellae, followed by necrosis, sometimes associated with invasive algae or fungi. The most common microscopic lesion in corals manifesting tissue loss was cell necrosis often associated with algae, fungi, or protozoa. Corals with growth anomaly had microscopic evidence of hyperplasia of gastrovascular canals, followed by necrosis associated with algae or metazoa (polychaete worms). Several species of apparently normal corals also had microscopic changes, including the presence of bacterial aggregates or crustacea in tissues. A single type of gross lesion (e.g., discoloration) could have different microscopic manifestations. This phenomenon underlines the importance of using microscopy to provide a more systematic description of coral lesions and to detect potential pathogens associated with these lesions.

To brood or not to brood: Are marine invertebrates that protect their offspring more resilient to ocean acidification?

NASA Astrophysics Data System (ADS)

Lucey, Noelle Marie; Lombardi, Chiara; Demarchi, Lucia; Schulze, Anja; Gambi, Maria Cristina; Calosi, Piero

2015-07-01

Anthropogenic atmospheric carbon dioxide (CO2) is being absorbed by seawater resulting in increasingly acidic oceans, a process known as ocean acidification (OA). OA is thought to have largely deleterious effects on marine invertebrates, primarily impacting early life stages and consequently, their recruitment and species’ survival. Most research in this field has been limited to short-term, single-species and single-life stage studies, making it difficult to determine which taxa will be evolutionarily successful under OA conditions. We circumvent these limitations by relating the dominance and distribution of the known polychaete worm species living in a naturally acidic seawater vent system to their life history strategies. These data are coupled with breeding experiments, showing all dominant species in this natural system exhibit parental care. Our results provide evidence supporting the idea that long-term survival of marine species in acidic conditions is related to life history strategies where eggs are kept in protected maternal environments (brooders) or where larvae have no free swimming phases (direct developers). Our findings are the first to formally validate the hypothesis that species with life history strategies linked to parental care are more protected in an acidifying ocean compared to their relatives employing broadcast spawning and pelagic larval development.

Characterizing lesions in corals from American Samoa

USGS Publications Warehouse

Work, Thierry M.; Rameyer, Robert A.

2005-01-01

The study of coral disease has suffered from an absence of systematic approaches that are commonly used to determine causes of diseases in animals. There is a critical need to develop a standardized and portable nomenclature for coral lesions in the field and to incorporate more commonly available biomedical tools in coral disease surveys to determine the potential causes of lesions in corals. We characterized lesions in corals from American Samoa based on gross and microscopic morphology and classified them as discoloration, growth anomalies, or tissue loss. The most common microscopic finding in corals manifesting discoloration was the depletion of zooxanthellae, followed by necrosis, sometimes associated with invasive algae or fungi. The most common microscopic lesion in corals manifesting tissue loss was cell necrosis often associated with algae, fungi, or protozoa. Corals with growth anomaly had microscopic evidence of hyperplasia of gastrovascular canals, followed by necrosis associated with algae or metazoa (polychaete worms). Several species of apparently normal corals also had microscopic changes, including the presence of bacterial aggregates or crustacea in tissues. A single type of gross lesion (e.g., discoloration) could have different microscopic manifestations. This phenomenon underlines the importance of using microscopy to provide a more systematic description of coral lesions and to detect potential pathogens associated with these lesions.

Evaluating coral reef health in American Samoa

USGS Publications Warehouse

Work, Thierry M.; Rameyer, Robert A.

2005-01-01

The study of coral disease has suffered from an absence of systematic approaches that are commonly used to determine causes of diseases in animals. There is a critical need to develop a standardized and portable nomenclature for coral lesions in the field and to incorporate more commonly available biomedical tools in coral disease surveys to determine the potential causes of lesions in corals. We characterized lesions in corals from American Samoa based on gross and microscopic morphology and classified them as discoloration, growth anomalies, or tissue loss. The most common microscopic finding in corals manifesting discoloration was the depletion of zooxanthellae, followed by necrosis, sometimes associated with invasive algae or fungi. The most common microscopic lesion in corals manifesting tissue loss was cell necrosis often associated with algae, fungi, or protozoa. Corals with growth anomaly had microscopic evidence of hyperplasia of gastrovascular canals, followed by necrosis associated with algae or metazoa (polychaete worms). Several species of apparently normal corals also had microscopic changes, including the presence of bacterial aggregates or crustacea in tissues. A single type of gross lesion (e.g., discoloration) could have different microscopic manifestations. This phenomenon underlines the importance of using microscopy to provide a more systematic description of coral lesions and to detect potential pathogens associated with these lesions.

Exposure to low pH induces molecular level changes in the marine worm, Platynereis dumerilii.

PubMed

Wäge, Janine; Lerebours, Adelaide; Hardege, Jörg D; Rotchell, Jeanette M

2016-02-01

Fossil fuel emissions and changes in net land use lead to an increase in atmospheric CO2 concentration and a subsequent decrease of ocean pH. Noticeable effects on organisms' calcification rate, shell structure and energy metabolism have been reported in the literature. To date, little is known about the molecular mechanisms altered under low pH exposure, especially in non-calcifying organisms. We used a suppression subtractive hybridisation (SSH) approach to characterise differentially expressed genes isolated from Platynereis dumerilii, a non-calcifying marine polychaeta species, kept at normal and low pH conditions. Several gene sequences have been identified as differentially regulated. These are involved in processes previously considered as indicators of environment change, such as energy metabolism (NADH dehydrogenase, 2-oxoglutarate dehydrogenase, cytochrome c oxidase and ATP synthase subunit F), while others are involved in cytoskeleton function (paramyosin and calponin) and immune defence (fucolectin-1 and paneth cell-specific alpha-defensin) processes. This is the first study of differential gene expression in a non-calcifying, marine polychaete exposed to low pH seawater conditions and suggests that mechanisms of impact may include additional pathways not previously identified as impacted by low pH in other species. Copyright © 2015 Elsevier Inc. All rights reserved.

Deep-sea whale fall fauna from the Atlantic resembles that of the Pacific Ocean.

PubMed

Sumida, Paulo Y G; Alfaro-Lucas, Joan M; Shimabukuro, Mauricio; Kitazato, Hiroshi; Perez, Jose A A; Soares-Gomes, Abilio; Toyofuku, Takashi; Lima, Andre O S; Ara, Koichi; Fujiwara, Yoshihiro

2016-02-24

Whale carcasses create remarkable habitats in the deep-sea by producing concentrated sources of organic matter for a food-deprived biota as well as places of evolutionary novelty and biodiversity. Although many of the faunal patterns on whale falls have already been described, the biogeography of these communities is still poorly known especially from basins other than the NE Pacific Ocean. The present work describes the community composition of the deepest natural whale carcass described to date found at 4204 m depth on Southwest Atlantic Ocean with manned submersible Shinkai 6500. This is the first record of a natural whale fall in the deep Atlantic Ocean. The skeleton belonged to an Antarctic Minke whale composed of only nine caudal vertebrae, whose degradation state suggests it was on the bottom for 5-10 years. The fauna consisted mainly of galatheid crabs, a new species of the snail Rubyspira and polychaete worms, including a new Osedax species. Most of the 41 species found in the carcass are new to science, with several genera shared with NE Pacific whale falls and vent and seep ecosystems. This similarity suggests the whale-fall fauna is widespread and has dispersed in a stepping stone fashion, deeply influencing its evolutionary history.

Photographic evaluation of the impacts of bottom fishing on benthic epifauna

USGS Publications Warehouse

Collie, J.S.; Escanero, G.A.; Valentine, P.C.

2000-01-01

The gravel sediment habitat on the northern edge of Georges Bank (East coast of North America) is an important nursery area for juvenile fish, and the site of a productive scallop fishery. During two cruises to this area in 1994 we made photographic transects at sites of varying depths that experience varying degrees of disturbance from otter trawling and scallop dredging. Differences between sites were quantified by analyzing videos and still photographs of the sea bottom. Videos were analyzed for sediment types and organism abundance. In the still photos, the percentages of the bottom covered by bushy, plant-like organisms and colonial worm tubes (Filograna implexa) were determined, as was the presence/absence of encrusting bryozoa. Non-colonial organisms were also identified as specifically as possible and sediment type was quantified. Significant differences between disturbed and undisturbed areas were found for the variables measured in the still photos; colonial epifaunal species were conspicuously less abundant at disturbed sites. Results from the videos and still photos were generally consistent although less detail was visible in the videos. Emergent colonial epifauna provide a complex habitat for shrimp, polychaetes, brittle stars and small fish at undisturbed sites. Bottom fishing removes this epifauna, thereby reducing the complexity and species diversity of the benthic community. (C) 2000 International Council for the Exploration of the Sea.

Deep-sea whale fall fauna from the Atlantic resembles that of the Pacific Ocean

NASA Astrophysics Data System (ADS)

Sumida, Paulo Y. G.; Alfaro-Lucas, Joan M.; Shimabukuro, Mauricio; Kitazato, Hiroshi; Perez, Jose A. A.; Soares-Gomes, Abilio; Toyofuku, Takashi; Lima, Andre O. S.; Ara, Koichi; Fujiwara, Yoshihiro

2016-02-01

Whale carcasses create remarkable habitats in the deep-sea by producing concentrated sources of organic matter for a food-deprived biota as well as places of evolutionary novelty and biodiversity. Although many of the faunal patterns on whale falls have already been described, the biogeography of these communities is still poorly known especially from basins other than the NE Pacific Ocean. The present work describes the community composition of the deepest natural whale carcass described to date found at 4204 m depth on Southwest Atlantic Ocean with manned submersible Shinkai 6500. This is the first record of a natural whale fall in the deep Atlantic Ocean. The skeleton belonged to an Antarctic Minke whale composed of only nine caudal vertebrae, whose degradation state suggests it was on the bottom for 5-10 years. The fauna consisted mainly of galatheid crabs, a new species of the snail Rubyspira and polychaete worms, including a new Osedax species. Most of the 41 species found in the carcass are new to science, with several genera shared with NE Pacific whale falls and vent and seep ecosystems. This similarity suggests the whale-fall fauna is widespread and has dispersed in a stepping stone fashion, deeply influencing its evolutionary history.

Kirkegaardia (Polychaeta, Cirratulidae), new name for Monticellina Laubier, preoccupied in the Rhabdocoela, together with new records and descriptions of eight previously known and sixteen new species from the Atlantic, Pacific, and Southern Oceans.

PubMed

Blake, James A

2016-09-13

A new name, Kirkegaardia, is proposed to replace Monticellina Laubier, 1961, a bitentaculate cirratulid polychaete genus, that is a junior homonym of the turbellarian Monticellina Westblad, 1953 (Platyhelminthes, Rhabdocoela). In addition, the opportunity is taken to complete a major revision of the genus including the redescription, revalidation, and separation of three species previously referred to synonymy with K. dorsobranchialis (Kirkegaard, 1959) and five other previously described species. In addition, 16 new species are described from the western North Atlantic, eastern and central Pacific, off western South America, and seas around Antarctica, bringing the total number of species in the genus to 38. Included are two new species of the unusual mud ball worms, first reported as Tharyx luticastellus Jumars, 1975, from southern California deep basins. A review of all 38 species reveals that three distinct species groups may be identified within the genus in addition to 5-6 species that may eventually be referred elsewhere. This review includes a discussion of the taxonomic characters and various newly defined character states that are found among species of Kirkegaardia. Several of these are unique among the Cirratulidae.

A Tri-Oceanic Perspective: DNA Barcoding Reveals Geographic Structure and Cryptic Diversity in Canadian Polychaetes

PubMed Central

Carr, Christina M.; Hardy, Sarah M.; Brown, Tanya M.; Macdonald, Tara A.; Hebert, Paul D. N.

2011-01-01

Background Although polychaetes are one of the dominant taxa in marine communities, their distributions and taxonomic diversity are poorly understood. Recent studies have shown that many species thought to have broad distributions are actually a complex of allied species. In Canada, 12% of polychaete species are thought to occur in Atlantic, Arctic, and Pacific Oceans, but the extent of gene flow among their populations has not been tested. Methodology/Principal Findings Sequence variation in a segment of the mitochondrial cytochrome c oxidase I (COI) gene was employed to compare morphological versus molecular diversity estimates, to examine gene flow among populations of widespread species, and to explore connectivity patterns among Canada's three oceans. Analysis of 1876 specimens, representing 333 provisional species, revealed 40 times more sequence divergence between than within species (16.5% versus 0.38%). Genetic data suggest that one quarter of previously recognized species actually include two or more divergent lineages, indicating that richness in this region is currently underestimated. Few species with a tri-oceanic distribution showed genetic cohesion. Instead, large genetic breaks occur between Pacific and Atlantic-Arctic lineages, suggesting their long-term separation. High connectivity among Arctic and Atlantic regions and low connectivity with the Pacific further supports the conclusion that Canadian polychaetes are partitioned into two distinct faunas. Conclusions/Significance Results of this study confirm that COI sequences are an effective tool for species identification in polychaetes, and suggest that DNA barcoding will aid the recognition of species overlooked by the current taxonomic system. The consistent geographic structuring within presumed widespread species suggests that historical range fragmentation during the Pleistocene ultimately increased Canadian polychaete diversity and that the coastal British Columbia fauna played a minor role in Arctic recolonization following deglaciation. This study highlights the value of DNA barcoding for providing rapid insights into species distributions and biogeographic patterns in understudied groups. PMID:21829451

Lipid biomarkers of deep-sea hydrothermal vent polychaetes— Alvinella pompejana, A. caudata, Paralvinella grasslei and Hesiolyra bergii

NASA Astrophysics Data System (ADS)

Phleger, Charles F.; Nelson, Matthew M.; Groce, Ami K.; Craig Cary, S.; Coyne, Kathryn; Gibson, John A. E.; Nichols, Peter D.

2005-12-01

The lipid composition was determined for 5 species of polychaete annelids collected by the Deep Submergence Vehicle ALVIN from high temperature chimneys at the 2500 m depth hydrothermal vent field of the East Pacific Rise. These are the first lipid biomarker analyses reported for these hydrothermal vent polychaetes. Lipid content was low in all samples (1.6-35.9 mg g -1 wet mass) and was dominated by polar lipid (78-90% of total lipid) with 8-19% sterol (ST), and very low storage lipid (triacylglycerol and wax ester). Total polyunsaturated fatty acids (PUFA) were moderately high (22-31% of total fatty acids (FA)) with extremely low or no docosahexaenoic acid (DHA, 22:6(n-3)). Eicosapentaenoic acid (EPA, 20:5(n-3)) levels were 5-6% in Alvinella pompejana and A. caudata and 10.3-13.7% in an errantiate polychaete (likely Hesionidae) and Hesiolyra bergii. There were greater PUFA and a greater EPA/AA (AA is arachidonic acid, 20:4(n-6)) ratio in the anterior versus the posterior half of A. pompejana, which may correlate to the strong temperature gradient reported in its tube. Total nonmethylene interrupted diunsaturated fatty acids (NMID) were 4-9% of total FA for most polychaete species and included several 20:2 and 22:2 components. The principal monounsaturated fatty acids (MUFA) included 18:1(n-7)c (14-19%), 16:1(n-7)c (2.6-10%) and 20:1(n-11)c (3-7% of total FA). These polychaete species may desaturate and elongate the bacterial-derived 18:1(n-7)c to obtain the essential FA EPA and AA. The major ST in the polychaetes is cholesterol (89-98% of total ST) with less cholesterol in the gut contents of A. pompejana. Other ST included 24-ethylcholesterol (1.5-5% of total ST) with lesser amounts of 24-methylenecholesterol, desmosterol, lathosterol, 24-methylcholesterol, 24-ethylcholesterol, and the stanols dehydrocholestanol and cholestanol. The high ST levels could play a role in thermal adaptation of membranes at the hydrothermal vent environment. Differences in the FA profiles separated the closely related species A. pompejana and A. caudata from Paralvinella grasslei, H. bergii, and the errantiate polychaete (likely Hesionidae).

THE EFFECTS OF SALINITY CHANGE ON THE FREE AMINO ACID POOLS OF TWO NEREID POLYCHAETES, 'NEANTHES SUCCINEA' AND 'LEONEREIS CULVERI'

EPA Science Inventory

The response of the free amino acid pools of two nereid polychaetes, Neanthes succinea and Leonereis culveri to both increased and decreased salinities was examined. In both species, glycine and alanine accounted for most of the observed change in the total free amino acid (FAA) ...

Final Environmental Assessment for Test Area D-84 Waterside Redevelopment

DTIC Science & Technology

2012-09-01

typically adapted for life in saturated soil conditions (U.S. Army, 1987). Wetlands are the most productive ecosystems in the world (Mitsch and...such as amphipods, Jancelets, polychaetes, gastropods , ghost shrimp, isopods, molluscs and/or crustaceans, within estuarine and marine habitats and...lancelets, polychaetes, gastropods , ghost shrimp, isopods, mollusks, and/or crustaceans within estuarine and marine habitats and substrates for subadult

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 than those from afaunal controls. Aldose suite alterations were similar in faunated microcosms and afaunal controls, however the impact of faunal gut passage on sedimentary aldose compositions may be observable over longer timescales. Therefore this study provides direct evidence that polychaete gut passage influences OM composition both through taxon-specific selective assimilation and retention in polychaete tissues, and also through interactions with the microbial community. Polychaete gut passage will result in selective loss, preservation, and retention in polychaete tissues of specific aldoses and fatty acids. The pattern of selectivity will be taxon specific. Changes observed during gut passage will align with those commonly observed during OM decay, thus indicating that macrofaunal gut passage is one of the factors controlling sedimentary OM composition. Together with a previous publication reporting amino acid data from the same experiments (Woulds et al., 2012), this study represents the most complete description of OM alteration during gut passage that is available to date.

Evaluation of Venturi Oxygen Stripping (trademark) as a Ballast Water Treatment to Prevent Aquatic Invasions and Ship Corrosion

DTIC Science & Technology

2003-01-01

that can withstand low oxygen levels (e.g., resistant cysts of dinoflagellates, Hallegraeff 1998). Marine bacteria, in particular, will have...Chesapeake Bay zooplankton (copepods, barnacle larvae, polychaete larvae, cladocerans, crustacean nauplii, bivalve larvae, and nematodes ) in less than...zooplankton (copepods, barnacle larvae, polychaete larvae, cladocerans, crustacean nauplii, bivalve larvae, and nematodes ) in control and treated

Evaluation of Dredged Material Proposed for Ocean Disposal. Testing Manual

DTIC Science & Technology

1991-02-01

should include a deposit-feeding amphipod and a polychaete. Bioaccumulation tests generally should include a deposit-feeding bivalve mollusc and a...Gibson. 1987. Regulatory identification of petroleum hydrocarbons in dredged material. Proceedings of a Workshop. Misc. Pap. D-87-3, U.S. Army... Bioaccumulation from Whole-Sediment Tests. Polychaetes Molluscs Neanthes sp.* Macoma clam, Macoma sp.* Nereis sp.* Yoldia clam, Yoldia limatula Nephiy sp.* Nucula

Toxicological responses of Laeonereis acuta (Polychaeta, Nereididae) after acute, subchronic and chronic exposure to cadmium.

PubMed

Dolagaratz Carricavur, Arantxa; Chiodi Boudet, Leila; Romero, María Belén; Polizzi, Paula; Marcovecchio, Jorge Eduardo; Gerpe, Marcela

2018-03-01

The objective of this study was to analyze the toxicological responses of the estuarine polychaete Laeonereis acuta after acute (96h), subchronic (7 days) and chronic (14 days) exposure to cadmium (Cd). Concentrations of metallothioneins (MT), lipid peroxidation (LPO), total Cd and metal-rich granules (MRG) were evaluated. Seasonal variations of MT and LPO levels in the wild were also measured. Polychaetes were obtained in the Quequén estuary located southeast of Buenos Aires Province, Argentina. For the acute toxicity assay, individuals were exposed to 10; 30, 65; 310; 600; 1300; 2000; 4300; 8100; 16300µgCdL -1 , which included levels of environmental relevance and median lethal concentrations (LC 50 ) for related species of polychaete. Based on 96h LC 50 values, polychaetes were exposed to sublethal doses of Cd. The concentrations for both subchronic and chronic assays were: 10; 30; 65; 310; 600; 1300; 2000; 4300µgCdL -1 . The 96h LC 50 value was 8234.9µgL -1 , which was within the values reported for other species of polychaete, indicating a high tolerance to Cd. MT induction was not observed for any time exposure. In additoin, LPO levels showed no differences with respect to control levels, which indicated an absence of oxidative damage caused by Cd. However, the total Cd and MRG-Cd concentrations in L. acuta in all tested treatments showed significant differences with respect to control levels. L. acuta were able to accumulate Cd in their tissues in the form of granules which are the main mechanism of Cd detoxification. Copyright © 2017 Elsevier Inc. All rights reserved.

Polychaetes of Greece: an updated and annotated checklist

PubMed Central

Simboura, Nomiki; Katsiaras, Nikolaos; Chatzigeorgiou, Giorgos; Arvanitidis, Christos

2017-01-01

Abstract Background The last annotated checklist of marine polychaetes in Greece was published in 2001. Since then, global taxonomic progress, combined with many new species records for Greece, required a thorough review of the taxonomic, nomenclatural and biogeographic status of the national species list. This checklist revises the status of all extant polychaete species reported from the Greek Exclusive Economic Zone since 1832. The work was undertaken as part of the efforts on compiling a national species inventory (Greek Taxon Information System initiative) in the framework of the LifeWatchGreece Research Infrastructure. New information This checklist comprises an updated and annotated inventory of polychaete species in Greek waters, compiled from literature reports, online databases, museum collections and unpublished datasets. The list provides information on 836 species-level taxa from Greece, of which 142 are considered questionable. An additional 84 species reported in the past are currently considered absent from Greece; reasons for the exclusion of each species are given. Fourteen species are reported here for the first time from Greek waters. At least 52 species in the present list constitute in fact a complex of cryptic or pseudo-cryptic species. Forty-seven species are considered non-native to the area. In addition to the species-level taxa reported in this checklist, eleven genera have been recorded from Greece with no representatives identified to species level. One replacement name is introduced. For each species, a comprehensive bibliographic list of occurrence records in Greece and the synonyms used in these publications are provided as supplementary material. Where necessary, the taxonomic, nomenclatural or biogeographic status is discussed. Finally, the findings are discussed in the wider context of Mediterranean polychaete biogeography, taxonomic practice and worldwide research progress. PMID:29362552

Genotoxicity of two heavy metal compounds: lead nitrate and cobalt chloride in Polychaete Perinereis cultrifera.

PubMed

Singh, Nisha; Bhagat, Jacky; Ingole, Baban S

2017-07-01

The present study explores the in vivo and in vitro genotoxic effects of lead nitrate, [Pb(NO 3 ) 2 ] a recognized environmental pollutant and cobalt chloride (CoCl 2 ), an emerging environmental pollutant in polychaete Perinereis cultrifera using comet assay. Despite widespread occurrence and extensive industrial applications, no previous published reports on genotoxicity of these compounds are available in polychaete as detected by comet assay. Polychaetes were exposed in vivo to Pb(NO 3 ) 2 (0, 100, 500, and 1000 μg/l) and CoCl 2 (0, 100, 300, and 500 μg/l) for 5 days. At 100 μg/l Pb(NO 3 ) 2 concentration, tail DNA (TDNA) values in coelomocytes were increase by 1.16, 1.43, and 1.55-fold after day 1, day 3, and day 5, whereas, OTM showed 1.12, 2.33, and 2.10-fold increase in in vivo. Pb(NO 3 ) 2 showed a concentration and time-dependent genotoxicity whereas CoCl 2 showed a concentration-dependent genotoxicity in in vivo. A concentration-dependent increase in DNA damage was observed in in vitro studies for Pb(NO 3 ) 2 and CoCl 2 . DNA damage at 500 μg/L showed almost threefold increase in TDNA and approximately fourfold increase in OTM as compared to control in in vitro. Our studies suggest that Pb(NO 3 ) 2 and CoCl 2 have potential to cause genotoxic damage, with Pb(NO 3 ) 2 being more genotoxic in polychaete and should be used more carefully in industrial and other activities. Graphical abstract.

Distinct patterns of genetic differentiation among annelids of eastern Pacific hydrothermal vents.

PubMed

Hurtado, L A; Lutz, R A; Vrijenhoek, R C

2004-09-01

Population genetic and phylogenetic analyses of mitochondrial COI from five deep-sea hydrothermal vent annelids provided insights into their dispersal modes and barriers to gene flow. These polychaetes inhabit vent fields located along the East Pacific Rise (EPR) and Galapagos Rift (GAR), where hundreds to thousands of kilometers can separate island-like populations. Long-distance dispersal occurs via larval stages, but larval life histories differ among these taxa. Mitochondrial gene flow between populations of Riftia pachyptila, a siboglinid worm with neutrally buoyant lecithothrophic larvae, is diminished across the Easter Microplate region, which lies at the boundary of Indo-Pacific and Antarctic deep-sea provinces. Populations of the siboglinid Tevnia jerichonana are similarly subdivided. Oasisia alvinae is not found on the southern EPR, but northern EPR populations of this siboglinid are subdivided across the Rivera Fracture Zone. Mitochondrial gene flow of Alvinella pompejana, an alvinellid with large negatively buoyant lecithotrophic eggs and arrested embryonic development, is unimpeded across the Easter Microplate region. Gene flow in the polynoid Branchipolynoe symmytilida also is unimpeded across the Easter Microplate region. However, A. pompejana populations are subdivided across the equator, whereas B. symmitilida populations are subdivided between the EPR and GAR axes. The present findings are compared with similar evidence from codistributed species of annelids, molluscs and crustaceans to identify potential dispersal filters in these eastern Pacific ridge systems.

Augmentation of French grunt diet description using combined visual and DNA-based analyses

USGS Publications Warehouse

Hargrove, John S.; Parkyn, Daryl C.; Murie, Debra J.; Demopoulos, Amanda W.J.; Austin, James D.

2012-01-01

Trophic linkages within a coral-reef ecosystem may be difficult to discern in fish species that reside on, but do not forage on, coral reefs. Furthermore, dietary analysis of fish can be difficult in situations where prey is thoroughly macerated, resulting in many visually unrecognisable food items. The present study examined whether the inclusion of a DNA-based method could improve the identification of prey consumed by French grunt, Haemulon flavolineatum, a reef fish that possesses pharyngeal teeth and forages on soft-bodied prey items. Visual analysis indicated that crustaceans were most abundant numerically (38.9%), followed by sipunculans (31.0%) and polychaete worms (5.2%), with a substantial number of unidentified prey (12.7%). For the subset of prey with both visual and molecular data, there was a marked reduction in the number of unidentified sipunculans (visual – 31.1%, combined &ndash 4.4%), unidentified crustaceans (visual &ndash 15.6%, combined &ndash 6.7%), and unidentified taxa (visual &ndash 11.1%, combined &ndash 0.0%). Utilising results from both methodologies resulted in an increased number of prey placed at the family level (visual &ndash 6, combined &ndash 33) and species level (visual &ndash 0, combined &ndash 4). Although more costly than visual analysis alone, our study demonstrated the feasibility of DNA-based identification of visually unidentifiable prey in the stomach contents of fish.

Seasonal variations in the community structures of macrobenthic fauna and their health status in an estuarine bay, Gwangyang Bay in Korea

NASA Astrophysics Data System (ADS)

Seo, Jin-Young; An, Soon-Mo; Lim, Dhong-il; Choi, Jin-Woo

2017-09-01

Macrobenthic fauna in an estuarine Gwangyang Bay, southern Korean coast, were investigated to uncover recent variations in their community structures. In the study area, macrobenthic faunal communities were mainly composed of polychaete worms which were the most abundant faunal group with the highest values in species number and density, while mollusks accounted for the highest proportion in total biomass. There was no clear seasonal difference in species richness during the two year period of the investigation, but the mean density and biomass increased every spring and summer due to the mass recruitment of Theora fragilis. The Shannon's diversity index (H') was more than 2.0 during most sampling seasons and did not show any significant seasonal difference except for the data in August, 2011 when azoic conditions occurred. The community structures of macrobenthos in Gwangyang Bay did not show any remarkable change in the dominance of the two top dominant species, Scoletoma longifolia and Heteromastus filiformis, which abundantly occurred in all seasons, except for the abundance peaks associated with high occurrence of T. fragilis and Paraprionospio cordifolia, especially in spring and summer and in autumn, respectively. These fauna changes reflected the changes in the macrobenthic community health status in Gwangyang Bay, where stable conditions and a healthy status prevailed in winter, but a slightly disturbed status prevailed from spring to autumn.

Marine biorhythms: bridging chronobiology and ecology.

PubMed

Bulla, Martin; Oudman, Thomas; Bijleveld, Allert I; Piersma, Theunis; Kyriacou, Charalambos P

2017-11-19

Marine organisms adapt to complex temporal environments that include daily, tidal, semi-lunar, lunar and seasonal cycles. However, our understanding of marine biological rhythms and their underlying molecular basis is mainly confined to a few model organisms in rather simplistic laboratory settings. Here, we use new empirical data and recent examples of marine biorhythms to highlight how field ecologists and laboratory chronobiologists can complement each other's efforts. First, with continuous tracking of intertidal shorebirds in the field, we reveal individual differences in tidal and circadian foraging rhythms. Second, we demonstrate that shorebird species that spend 8-10 months in tidal environments rarely maintain such tidal or circadian rhythms during breeding, likely because of other, more pertinent, temporally structured, local ecological pressures such as predation or social environment. Finally, we use examples of initial findings from invertebrates (arthropods and polychaete worms) that are being developed as model species to study the molecular bases of lunar-related rhythms. These examples indicate that canonical circadian clock genes (i.e. the homologous clock genes identified in many higher organisms) may not be involved in lunar/tidal phenotypes. Together, our results and the examples we describe emphasize that linking field and laboratory studies is likely to generate a better ecological appreciation of lunar-related rhythms in the wild.This article is part of the themed issue 'Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals'. © 2017 The Authors.

Processes controlling the physico-chemical micro-environments associated with Pompeii worms

NASA Astrophysics Data System (ADS)

Le Bris, N.; Zbinden, M.; Gaill, F.

2005-06-01

Alvinella pompejana is a tube-dwelling polychaete colonizing hydrothermal smokers of the East Pacific Rise. Extreme temperature, low pH and millimolar sulfide levels have been reported in its immediate surroundings. The conditions experienced by this organism and its associated microbes are, however, poorly known and the processes controlling the physico-chemical gradients in this environment remain to be elucidated. Using miniature in situ sensors coupled with close-up video imagery, we have characterized fine-scale pH and temperature profiles in the biogeoassemblage constituting A. pompejana colonies. Steep discontinuities at both the individual and the colony scale were highlighted, indicating a partitioning of the vent fluid-seawater interface into chemically and thermally distinct micro-environments. The comparison of geochemical models with these data furthermore reveals that temperature is not a relevant tracer of the fluid dilution at these scales. The inner-tube micro-environment is expected to be supplied from the seawater-dominated medium overlying tube openings and to undergo subsequent conductive heating through the tube walls. Its neutral pH is likely to be associated with moderately oxidative conditions. Such a model provides an explanation of the atypical thermal and chemical patterns that were previously reported for this medium from discrete samples and in situ measurements. Conversely, the medium surrounding the tubes is shown to be dominated by the fluid venting from the chimney wall. This hot fluid appears to be gradually cooled (120-30 °C) as it passes through the thickness of the worm colony, as a result of a thermal exchange mechanism induced by the tube assemblage. Its pH, however, remains very low (pH˜4), and reducing conditions can be expected in this medium. Such a thermal and chemical buffering mechanism is consistent with the mineralogical anomalies previously highlighted and provides a first explanation of the exceptional ability of these animals to colonize this hostile biotope. It furthermore suggests that A. pompejana, in providing various buffered micro-niches, would act as a primary player of microbial and related biogeochemical processes in this environment.

Bone-eating Osedax worms (Annelida: Siboglinidae) regulate biodiversity of deep-sea whale-fall communities

NASA Astrophysics Data System (ADS)

Alfaro-Lucas, Joan M.; Shimabukuro, Maurício; Ferreira, Giulia D.; Kitazato, Hiroshi; Fujiwara, Yoshihiro; Sumida, Paulo Y. G.

2017-12-01

Although it is well recognized the capital role of "bone-eating" Osedax worms in the degradation of vertebrate skeletons in the deep sea, very little is known about their effects on bone faunal assemblages. Here we aim to shed light on the bone colonization process and determine 1) whether Osedax degradation induces different bone epi/infaunal assemblages and 2) how biodiversity is affected by Osedax colonization. We describe and compare the epi/infaunal assemblage structures of caudal vertebrae colonized and not colonized by Osedax of an abyssal juvenile whale carcass serendipitously found at 4204 m depth in the SW Atlantic Ocean by HOV Shinkai 6500. Our results show that whale skeletons are very heterogeneous habitats that harbor specific and very rich assemblages and that contrasting epi/infaunal community patterns are found depending on the presence of Osedax. Vertebrae not colonized by Osedax were both well preserved and in a highly sulfophilic stage with chemosynthetic bacterial mats and numerous epifaunal organisms that fed on them. On the contrary, vertebrae colonized by Osedax were heavily degraded and did not exhibit evidence of a sulfophilic stage, harboring a distinct epifaunal assemblage. In general, bone infaunal assemblages were dominated by nematodes, especially in vertebrae without Osedax (ca. 77%) where organisms were only found in bone outer layers, showing a colonization pattern similar to that described for bacteria. Infauna in Osedax-colonized bones were present throughout the inner-matrices and were on average three times more abundant (ca. 1800 ind. 100 cm-3) and twice as rich in number of species (16 species). Here, bones had a relatively higher proportion of the polychaete Capitella iatapiuna (ca. 39%) in comparison with nematodes (ca. 52%). Besides, a higher number of rare species were present in bones with Osedax. We suggest that Osedax degradation increases water diffusion through matrices probably modifying reduced-compound fluxes and truncating the sulfophilic stage. Furthermore, it is likely that larger and distinct infaunal biodiversity is a result of an increase in bone structural complexity caused by Osedax, which also facilitates the colonization of inner-bone matrices. We conclude that Osedax is an important ecosystem engineer that enhances biodiversity in deep-sea whale-fall communities.

Polychaete community structure in the South Eastern Arabian Sea continental margin (200-1000 m)

NASA Astrophysics Data System (ADS)

Abdul Jaleel, K. U.; Anil Kumar, P. R.; Nousher Khan, K.; Correya, Neil S.; Jacob, Jini; Philip, Rosamma; Sanjeevan, V. N.; Damodaran, R.

2014-11-01

Macrofaunal polychaete communities (>500 μm) in the South Eastern Arabian Sea (SEAS) continental margin (200-1000 m) are described, based on three systematic surveys carried out in 9 transects (at ~200 m, 500 m and 1000 m) between 7°00‧and 14°30‧N latitudes. A total of 7938 polychaetes belonging to 195 species were obtained in 136 grab samples collected at 27 sites. Three distinct assemblages were identified in the northern part of the SEAS margin (10-14°30‧N), occupying the three sampled depth strata (shelf edge, upper and mid-slope) and two assemblages (shelf edge and slope) in the south (7-10°N). Highest density of polychaetes and dominance of a few species were observed in the shelf edge, where the Arabian Sea oxygen minimum zone (OMZ) impinged on the seafloor, particularly in the northern transects. The resident fauna in this region (Cossura coasta, Paraonis gracilis, Prionospio spp. and Tharyx spp.) were characteristically of smaller size, and well suited to thrive in the sandy sediments in OMZ settings. Densities were lowest along the most northerly transect (T9), where dissolved oxygen (DO) concentrations were extremely low (<0.15 ml l-1, i.e.<6.7 μmol l-1). Beyond the realm of influence of the OMZ (i.e. mid-slope, ~1000 m), the faunal density decreased while species diversity increased. The relative proportion of silt increased with depth, and the dominance of the aforementioned species decreased, giving way to forms such as Paraprionospio pinnata, Notomastus sp., Eunoe sp. and lumbrinerids. Relatively high species richness and diversity were observed in the sandy sediments of the southern sector (7-9°N), where influence of the OMZ was less intense. The area was also characterized by certain species (e.g. Aionidella cirrobranchiata, Isolda pulchella) that were nearly absent in the northern region. The gradients in DO concentration across the core and lower boundary of the OMZ, along with bathymetric and latitudinal variation in sediment texture, were responsible for differences in polychaete size and community structure on the SEAS margin. Spatial and temporal variations were observed in organic matter (OM) content of the sediment, but these were not reflected in the density, diversity or distribution pattern of the polychaetes.

Biogeochemical analysis of the calcification patterns of cold-water corals Madrepora oculata and Lophelia pertusa along contact surfaces with calcified tubes of the symbiotic polychaete Eunice norvegica: Evaluation of a 'mucus' calcification hypothesis

NASA Astrophysics Data System (ADS)

Oppelt, Alexandra; López Correa, Matthias; Rocha, Carlos

2017-09-01

The scleractinian cold-water corals (CWCs), including the species Madrepora oculata and especially Lophelia pertusa, have been studied extensively in an attempt to decipher environmental signals recorded during biomineralisation in order to extract environmental chronologies. However, understanding the mechanisms of carbonate precipitation is a prerequisite to interpret variations in geochemical signatures locked into the skeleton during coral growth; to date results are still inconclusive. Here a novel approach, comparing the calcification patterns within the coral microstructure of species L. pertusa and M. oculata and the geochemistry along the contact surfaces with calcified polychaete tubes is undertaken to provide additional information on the mechanisms of biomineralisation in colonial corals. The fact that no significant difference in microstructures, variations in growth rate, or geochemical composition between the corallite theca and the calcified polychaete tube was detectable leads to the conclusion that both have been deposited by the coral tissue in L. pertusa and M. oculata. Based on prior knowledge on the symbiotic relationship between CWCs and the polychaete Eunice norvegica, an involvement of mucus in the calcification of the parchment tubes had been suspected. However, we found only evidence for aragonite precipitated by coral tissue, without evidence for an involvement of mucus in the calcification.

Antioxidant capacity of polychaetes occurring at a natural CO2 vent system: Results of an in situ reciprocal transplant experiment.

PubMed

Ricevuto, E; Benedetti, M; Regoli, F; Spicer, J I; Gambi, M C

2015-12-01

Ocean acidification (OA) is occurring at a fast rate, resulting in changes of carbonate chemistry in the oceans and in lowering of the pH. Previous studies have documented significant changes in the antioxidant defenses of marine species in response to OA. Here, selected polychaete species, Platynereis dumerilii, Polyophthalmus pictus and Syllis prolifera, were sampled from a natural CO2 vent system (pH = 7.3) and from a non-venting 'control' site (pH = 8.1), and reciprocally transplanted in these areas for 30 days. Total antioxidant capacity toward different forms of oxyradicals was compared in native and transplanted polychaetes: the aim was to assess whether the environmental conditions at the vent site would act as a prooxidant stressor, and the capability of polychaetes to modulate their antioxidant capacity to counteract a varied oxyradicals formation. None of the investigated species enhanced the antioxidant potential during the experiment. A significant reduction of the capability to neutralize different forms of oxyradicals was observed in P. pictus and, partially, in S. prolifera when transplanted from control to naturally-acidified conditions. On the other hand, populations of P. dumerilii originating from the vent and of S. prolifera from both control and acidified sites, showed higher constitutive antioxidant efficiency toward peroxyl radicals and peroxynitrite, which may allow them to cope with short-term and chronic exposure to higher oxidative pressure without further enhancement of antioxidant defenses. Since low pH - high pCO2 is the greatest environmental difference between the control and the vent sites, we suggest that the pro-oxidant challenge due to such peculiarities may have different biological consequences in different polychaete species. Some appear more susceptible to oxidative effects, while others acquire a long term acclimatization to vent conditions through the enhancement of their basal antioxidant protection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Loxosomella decorata n. sp., a new solitary entoproct from San Juan Island, WA, USA.

PubMed

Nielsen, Claus

2017-03-06

Several species of solitary entoprocts of the genera Loxosoma and Loxosomella occur on maldanid polychaetes or in their tubes (Nielsen 1964). New species turn up almost every time maldanids from new localities are studied, and the species described below has been the subject of a study of spiral cleavage (Merkel et al. 2012). This paper describes a new species of Loxosomella from tubes of the maldanid polychaete Axiothella rubrocincta (Johnson, 1901) from False Bay, San Juan Island, WA, USA.

Habitat selection and adult-recruit interactions in Pectinaria koreni (Malmgren) (Annelida: Polychaeta) post-larval populations: Results of flume experiments

NASA Astrophysics Data System (ADS)

Olivier, Frédéric; Desroy, Nicolas; Retière, Christian

1996-12-01

The fate of recently settled populations of soft-bottom invertebrates depends not only on dispersal of pelagic larvae by tidal currents but also on other physical ( e. g. resuspension) and biological mechanisms ( e.g. habitat selection and adult-recruit interactions) acting at the water-substratum interface. To assess the relative importance of such processes under megatidal conditions in the Abra alba community of the eastern Baie de Seine (English Channel), flume experiments were conducted on post-larvae of the dominant polychaete species, Pectinaria koreni. Habitat selection by post-larvae of P. koreni was determined in a first set of experiments, where individuals were sowed either on a suitable or on an unsuitable substratum. Once resuspended, post-larvae were given a choice between two highly contrasting treatments with a natural organic-rich muddy sand and a bare flat PVC surface. P. koreni post-larvae were able to leave an unfavourable substratum into which they had initially burrowed and reach a more suitable substrate by drifting (induced by the secretion of mucus) before final settlement. The influence of adults on habitat selection and survival of P. koreni post-larvae was analysed in a second set of experiments, where individuals were sowed onto a suitable sediment with adults (test treatment) or without (control treatment). The presence of conspecific adults induced a high resuspension rate of the post-larvae. Drifting occurred mainly just after the introduction of the current and affected the whole experimental population, regardless of size. Such a response seems to be related to the intense bioturbation caused by the sub-surface deposit-feeding habit of the adults, which alters the boundary-layer flow. In contrast, the presence of adults of Owenia fusiformis, another dominant polychaete of the Abra alba community, led to an enhanced recruitment by a reduction in post-larvae resuspension. In fact, at low shear velocities, dense aggregates of tubes stabilize the sediment and so act as particle traps. Thus, in the megatidal environment of the Baie de Seine, physical conditions and behavioural responses interact and contribute to structuring the benthic community.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burgess, R.M.; Perron, M.M.; Friedman, C.L.

Approaches for cleaning up contaminated sediments range from dredging to in situ treatment. In this study, we discuss the effects of amending reference and contaminated sediments with coal fly ash to reduce the bioavailability and toxicity of a field sediment contaminated with polycyclic aromatic hydrocarbons (PAHs). Six fly ashes and a coconut charcoal were evaluated in 7-d whole sediment toxicity tests with a marine amphipod (Ampelisca abdita) and mysid (Americamysis bahia). Fly ashes with high carbon content and the coconut charcoal showed proficiency at reducing toxicity. Some of the fly ashes demonstrated toxicity in the reference treatments. It is suspectedmore » that some of this toxicity is related to the presence of ammonia associated with fly ashes as a result of postoxidation treatment to reduce nitrous oxide emissions. Relatively simple methods exist to remove ammonia from fly ash before use, and fly ashes with low ammonia content are available. Fly ashes were also shown to effectively reduce overlying water concentrations of several PAHs. No evidence was seen of the release of the metals cadmium, copper, nickel, or lead from the fly ashes. A preliminary 28-d polychaete bioaccumulation study with one of the high-carbon fly ashes and a reference sediment was also performed. Although preliminary, no evidence was seen of adverse effects to worm growth or lipid content or of accumulation of PAHs or mercury from exposure to the fly ash. These data show fly ashes with high carbon content could represent viable remedial materials for reducing the bioavailability of organic contaminants in sediments.« less

Adaptation of gastrointestinal nematode parasites to host genotype: single locus simulation models

PubMed Central

2013-01-01

Background Breeding livestock for improved resistance to disease is an increasingly important selection goal. However, the risk of pathogens adapting to livestock bred for improved disease resistance is difficult to quantify. Here, we explore the possibility of gastrointestinal worms adapting to sheep bred for low faecal worm egg count using computer simulation. Our model assumes sheep and worm genotypes interact at a single locus, such that the effect of an A allele in sheep is dependent on worm genotype, and the B allele in worms is favourable for parasitizing the A allele sheep but may increase mortality on pasture. We describe the requirements for adaptation and test if worm adaptation (1) is slowed by non-genetic features of worm infections and (2) can occur with little observable change in faecal worm egg count. Results Adaptation in worms was found to be primarily influenced by overall worm fitness, viz. the balance between the advantage of the B allele during the parasitic stage in sheep and its disadvantage on pasture. Genetic variation at the interacting locus in worms could be from de novo or segregating mutations, but de novo mutations are rare and segregating mutations are likely constrained to have (near) neutral effects on worm fitness. Most other aspects of the worm infection we modelled did not affect the outcomes. However, the host-controlled mechanism to reduce faecal worm egg count by lowering worm fecundity reduced the selection pressure on worms to adapt compared to other mechanisms, such as increasing worm mortality. Temporal changes in worm egg count were unreliable for detecting adaptation, despite the steady environment assumed in the simulations. Conclusions Adaptation of worms to sheep selected for low faecal worm egg count requires an allele segregating in worms that is favourable in animals with improved resistance but less favourable in other animals. Obtaining alleles with this specific property seems unlikely. With support from experimental data, we conclude that selection for low faecal worm egg count should be stable over a short time frame (e.g. 20 years). We are further exploring model outcomes with multiple loci and comparing outcomes to other control strategies. PMID:23714384

Meiobenthic communities in permanently open estuaries and open/closed coastal lagoons of Uruguay (Atlantic coast of South America)

NASA Astrophysics Data System (ADS)

Kandratavicius, N.; Muniz, P.; Venturini, N.; Giménez, L.

2015-09-01

This study aimed to determine if estuarine meiofaunal communities of Uruguay (South America) vary between permanently open estuaries and open/closed coastal lagoons, or if they respond to the sediment composition. In Uruguay, estuaries and coastal lagoons vary in the degree of connectivity to the sea and in the sediment composition; sediments in estuaries are characterized by fine-medium sands but sediments vary from lagoon to lagoon (either fine-medium or coarse sand). Taxa richness (total = 16) showed less temporal variability in lagoons than in estuaries, due to patterns of presence/absence of the less abundant taxa. However, no major response to habitat was found in the most abundant groups: polychaetes (6% of total fauna) were on average 5% more abundant in lagoons than in estuaries. Some level of zonation, within estuaries and lagoons, was found in the most abundant groups, nematodes (63% of total fauna) and copepods (15%) in response to medium and fine sands. In addition, sediment type modulated seasonal patterns in the frequency of presence/absence in ostracods, polychaetes and oligochaetes. For instance, in polychaetes and ostracods the increase in the frequency of absences, occurring from summer to winter, was stronger in lagoons and estuaries dominated by fine sands. The lagoon habitat appears to ameliorate the effects of unfavourable (winter) conditions in less abundant meiofaunal taxa. In summary, sediment fractions explain spatial patterns in the average abundance of organisms (e.g. nematodes) as well as the seasonal changes in frequency of presence/absence (e.g. polychaetes).

QuantWorm: a comprehensive software package for Caenorhabditis elegans phenotypic assays.

PubMed

Jung, Sang-Kyu; Aleman-Meza, Boanerges; Riepe, Celeste; Zhong, Weiwei

2014-01-01

Phenotypic assays are crucial in genetics; however, traditional methods that rely on human observation are unsuitable for quantitative, large-scale experiments. Furthermore, there is an increasing need for comprehensive analyses of multiple phenotypes to provide multidimensional information. Here we developed an automated, high-throughput computer imaging system for quantifying multiple Caenorhabditis elegans phenotypes. Our imaging system is composed of a microscope equipped with a digital camera and a motorized stage connected to a computer running the QuantWorm software package. Currently, the software package contains one data acquisition module and four image analysis programs: WormLifespan, WormLocomotion, WormLength, and WormEgg. The data acquisition module collects images and videos. The WormLifespan software counts the number of moving worms by using two time-lapse images; the WormLocomotion software computes the velocity of moving worms; the WormLength software measures worm body size; and the WormEgg software counts the number of eggs. To evaluate the performance of our software, we compared the results of our software with manual measurements. We then demonstrated the application of the QuantWorm software in a drug assay and a genetic assay. Overall, the QuantWorm software provided accurate measurements at a high speed. Software source code, executable programs, and sample images are available at www.quantworm.org. Our software package has several advantages over current imaging systems for C. elegans. It is an all-in-one package for quantifying multiple phenotypes. The QuantWorm software is written in Java and its source code is freely available, so it does not require use of commercial software or libraries. It can be run on multiple platforms and easily customized to cope with new methods and requirements.

Bacterial Microbiota Associated with the Glacier Ice Worm Is Dominated by Both Worm-Specific and Glacier-Derived Facultative Lineages

PubMed Central

Murakami, Takumi; Segawa, Takahiro; Dial, Roman; Takeuchi, Nozomu; Kohshima, Shiro; Hongoh, Yuichi

2017-01-01

The community structure of bacteria associated with the glacier ice worm Mesenchytraeus solifugus was analyzed by amplicon sequencing of 16S rRNA genes and their transcripts. Ice worms were collected from two distinct glaciers in Alaska, Harding Icefield and Byron Glacier, and glacier surfaces were also sampled for comparison. Marked differences were observed in bacterial community structures between the ice worm and glacier surface samples. Several bacterial phylotypes were detected almost exclusively in the ice worms, and these bacteria were phylogenetically affiliated with either animal-associated lineages or, interestingly, clades mostly consisting of glacier-indigenous species. The former included bacteria that belong to Mollicutes, Chlamydiae, Rickettsiales, and Lachnospiraceae, while the latter included Arcicella and Herminiimonas phylotypes. Among these bacteria enriched in ice worm samples, Mollicutes, Arcicella, and Herminiimonas phylotypes were abundantly and consistently detected in the ice worm samples; these phylotypes constituted the core microbiota associated with the ice worm. A fluorescence in situ hybridization analysis showed that Arcicella cells specifically colonized the epidermis of the ice worms. Other bacterial phylotypes detected in the ice worm samples were also abundantly recovered from the respective habitat glaciers; these bacteria may be food for ice worms to digest or temporary residents. Nevertheless, some were overrepresented in the ice worm RNA samples; they may also function as facultative gut bacteria. Our results indicate that the community structure of bacteria associated with ice worms is distinct from that in the associated glacier and includes worm-specific and facultative, glacier-indigenous lineages. PMID:28302989

Bacterial Microbiota Associated with the Glacier Ice Worm Is Dominated by Both Worm-Specific and Glacier-Derived Facultative Lineages.

PubMed

Murakami, Takumi; Segawa, Takahiro; Dial, Roman; Takeuchi, Nozomu; Kohshima, Shiro; Hongoh, Yuichi

2017-03-31

The community structure of bacteria associated with the glacier ice worm Mesenchytraeus solifugus was analyzed by amplicon sequencing of 16S rRNA genes and their transcripts. Ice worms were collected from two distinct glaciers in Alaska, Harding Icefield and Byron Glacier, and glacier surfaces were also sampled for comparison. Marked differences were observed in bacterial community structures between the ice worm and glacier surface samples. Several bacterial phylotypes were detected almost exclusively in the ice worms, and these bacteria were phylogenetically affiliated with either animal-associated lineages or, interestingly, clades mostly consisting of glacier-indigenous species. The former included bacteria that belong to Mollicutes, Chlamydiae, Rickettsiales, and Lachnospiraceae, while the latter included Arcicella and Herminiimonas phylotypes. Among these bacteria enriched in ice worm samples, Mollicutes, Arcicella, and Herminiimonas phylotypes were abundantly and consistently detected in the ice worm samples; these phylotypes constituted the core microbiota associated with the ice worm. A fluorescence in situ hybridization analysis showed that Arcicella cells specifically colonized the epidermis of the ice worms. Other bacterial phylotypes detected in the ice worm samples were also abundantly recovered from the respective habitat glaciers; these bacteria may be food for ice worms to digest or temporary residents. Nevertheless, some were overrepresented in the ice worm RNA samples; they may also function as facultative gut bacteria. Our results indicate that the community structure of bacteria associated with ice worms is distinct from that in the associated glacier and includes worm-specific and facultative, glacier-indigenous lineages.

Signs of Recent Volcanism and Hydrothermal Activity Along the Eastern Segment of the Galapagos Spreading Center

NASA Astrophysics Data System (ADS)

Raineault, N.; Smart, C.; Mayer, L. A.; Ballard, R. D.; Fisher, C. R.; Marsh, L.; Shank, T. M.

2016-12-01

Since the initial discovery of the Galápagos Spreading Center (GSC) vents in 1977, large-scale disturbances resulting from eruptive and tectonic activity have both destroyed and created vent habitats along the GSC. In 2015, the E/V Nautilus returned to the GSC with remotely operated vehicles (ROVs) to explore 17 kilometers of the rift valley from the Rosebud site in the west, to a previously unexplored temperature anomaly east of the Tempus Fugit vent site. In the years to over a decade since scientists last visited the Rosebud, Rose Garden, and Tempus Fugit sites, there were many changes. Most notably, the Rosebud site, where scientists found a nascent vent community and left site markers in 2002, was apparently covered with glassy basaltic sheet flows. In addition to visual exploration, oceanographic sensor measurements and direct sampling, we used the ROV Hercules imaging suite, comprised of stereo cameras and a structured light laser sensor to map an area of diffuse flow in the Tempus Fugit field (100 m x 150 m). The centimeter-level photographic and bathymetric maps created with this system, along with ROV HD video, samples, and environmental sensors, documented hydrothermal activity and changes in biological community structure (e.g., Riftia tubeworms observed in nascent stages of community development in 2011 were now, in 2015, in greater abundance (with tubes almost 4 m in length). The detection of active venting and associated faunal assemblages will provide insight into the temporal and spatial variability of venting activity at the Tempus Fugit site. On a visual survey of the Rift east of the Tempus Fugit site, extinct sulfide chimney structures were discovered and sampled. There were several chimneys and sulfide deposits in a span of over 8 km that ranged in height from over a half meter to 1.5 m tall. Diffuse flow hosting white and blue bacterial mats was observed near the chimneys complexes. The base of a large chimney structure, venting white fluids, as well as adjacent chemically-stained sediments supported vent-endemic fauna including the Pompeii worm (Alvinella pompejana) and other polychaete worms, along with pycnogonids, rat-tail fish, and galatheid crabs. This discovery provided the first evidence that the eastern segment of the GSC may have contained high-temperature, black smoker vents.

Starting a DNA barcode reference library for shallow water polychaetes from the southern European Atlantic coast.

PubMed

Lobo, Jorge; Teixeira, Marcos A L; Borges, Luisa M S; Ferreira, Maria S G; Hollatz, Claudia; Gomes, Pedro T; Sousa, Ronaldo; Ravara, Ascensão; Costa, Maria H; Costa, Filipe O

2016-01-01

Annelid polychaetes have been seldom the focus of dedicated DNA barcoding studies, despite their ecological relevance and often dominance, particularly in soft-bottom estuarine and coastal marine ecosystems. Here, we report the first assessment of the performance of DNA barcodes in the discrimination of shallow water polychaete species from the southern European Atlantic coast, focusing on specimens collected in estuaries and coastal ecosystems of Portugal. We analysed cytochrome oxidase I DNA barcodes (COI-5P) from 164 specimens, which were assigned to 51 morphospecies. To our data set from Portugal, we added available published sequences selected from the same species, genus or family, to inspect for taxonomic congruence among studies and collection location. The final data set comprised 290 specimens and 79 morphospecies, which generated 99 Barcode Index Numbers (BINs) within Barcode of Life Data Systems (BOLD). Among these, 22 BINs were singletons, 47 other BINs were concordant, confirming the initial identification based on morphological characters, and 30 were discordant, most of which consisted on multiple BINs found for the same morphospecies. Some of the most prominent cases in the latter category include Hediste diversicolor (O.F. Müller, 1776) (7), Eulalia viridis (Linnaeus, 1767) (2) and Owenia fusiformis (delle Chiaje, 1844) (5), all of them reported from Portugal and frequently used in ecological studies as environmental quality indicators. Our results for these species showed discordance between molecular lineages and morphospecies, or added additional relatively divergent lineages. The potential inaccuracies in environmental assessments, where underpinning polychaete species diversity is poorly resolved or clarified, demand additional and extensive investigation of the DNA barcode diversity in this group, in parallel with alpha taxonomy efforts. © 2015 John Wiley & Sons Ltd.

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.

Impaired growth in the polychaete Armandia brevis exposed to tributyltin in sediment.

PubMed

Meador, J P; Rice, C A

2001-03-01

Juveniles of the opheliid polychaete, Armandia brevis, were exposed to sediment-associated tributyltin (TBT) for 42 days to evaluate toxicity and bioaccumulation. Growth in this species was inhibited in a dose-response fashion by increasing concentrations of TBT. Even though the biota-sediment accumulation factor (BSAF) for TBT declined for the higher sediment concentrations, the total butyltins in tissue increased over all sediment concentrations. At the highest sediment concentrations, polychaetes bioaccumulated less TBT than expected, which was most likely due to reduced uptake and continued metabolism of the parent compound. The less than expected BSAF values exhibited by animals at the exposure concentrations causing severe effects are an important finding for assessing responses in the field. It appears that severe biological effects can occur in long-term experiments without the expected high tissue concentrations; an observation likely explained by altered toxicokinetics. Analysis of variance determined the lowest observed effect concentration for growth to be 191 ng/g sediment dry wt. for 21 days of exposure and 101 ng/g sediment dry wt. at day 42, indicating that 21 days was insufficient for delineating the steady-state toxicity response. When based on regression analysis, the sediment concentration causing a 25% inhibition in growth at 42 days exposure was 93 ng/g dry wt. (total organic carbon = 0.58%). A dose-response association was also determined for polychaete net weight and TBT in tissue. The tissue residue associated with a 25% reduction in growth was 2834 ng/g dry wt. at day 42. A comparison of these results with previous work indicates that juveniles are approximately three times more sensitive than adults to TBT exposure. The sediment concentrations affecting growth in this species are commonly found in urban waterways indicating potentially severe impacts for this and other sensitive species.

New species for the biomitigation of a super-intensive marine fish farm effluent: Combined use of polychaete-assisted sand filters and halophyte aquaponics.

PubMed

Marques, Bruna; Calado, Ricardo; Lillebø, Ana I

2017-12-01

The main objective of this study was to test an innovative biomitigation approach, where polychaete-assisted (Hediste diversicolor) sand filters were combined with the production of Halimione portulacoides in aquaponics, to remediate an organic-rich effluent generated by a super intensive fish farm operating a land-based RAS (Recirculating aquaculture system). The set up included four different experimental combinations that were periodically monitored for 5months. After this period, polychaete-assisted sand filters reduced in 70% the percentage of OM and the average densities increased from ≈400ind.m -2 to 7000ind.m -2 . H. portulacoides in aquaponics contributed to an average DIN (Dissolved inorganic Nitrogen) decrease of 65%, which increased to 67% when preceded by filter tanks stocked with polychaetes. From May until October (5months) halophytes biomass increased from 1.4kgm -2 ±0.7 (initial wet weight) to 18.6kgm -2 ±4.0. Bearing in mind that the uptake of carbon is mostly via photosynthesis and not though the uptake of dissolved inorganic carbon, this represents an approximate incorporation of ≈1.3kgm -2 carbon (C), ≈15gm -2 nitrogen (N) and ≈8gm -2 phosphorus (P) in the aerial part (76% of total biomass), and an approximate incorporation of ≈0.5kgm -2 carbon (C), ≈3gm -2 nitrogen (N) and ≈2gm -2 phosphorus (P) in the roots (24% of total biomass). In the present study, the potential of the two extractive species for biomitigation of a super-intensive marine fish farm effluent could be clearly demonstrated, contributing in this way to potentiate the implementation of more sustainable practices. Copyright © 2017 Elsevier B.V. All rights reserved.

21 CFR 520.905a - Fenbendazole suspension.

Code of Federal Regulations, 2013 CFR

2013-04-01

... worms (adults and 4th-stage larvae)—barberpole worm (Haemonchus contortus and H. placei) and small stomach worm (Trichostongylus axei); intestinal worms (adults and 4th-stage larvae)—hookworm (Bunostonmum... control of stomach worm (4th stage inhibited larvae/type II ostertagiasis), Ostertagia ostertagi, and...

21 CFR 520.905a - Fenbendazole suspension.

Code of Federal Regulations, 2014 CFR

2014-04-01

... worms (adults and 4th-stage larvae)—barberpole worm (Haemonchus contortus and H. placei) and small stomach worm (Trichostongylus axei); intestinal worms (adults and 4th-stage larvae)—hookworm (Bunostonmum... control of stomach worm (4th stage inhibited larvae/type II ostertagiasis), Ostertagia ostertagi, and...

Cutaneous Emergence of Eustrongylides in Two Persons from South Sudan

PubMed Central

Eberhard, Mark L.; Ruiz-Tiben, Ernesto

2014-01-01

Two large, living worms were collected as they emerged from the lower limb of each of two persons in South Sudan. The worms were observed by staff of the South Sudan Guinea Worm Eradication Program during surveillance activities in communities at-risk for cases of Guinea worm disease (dracunculiasis). The worms measured 7 and 8 cm in length and were identified as fourth-stage larvae of Eustrongylides. This is the first report of such worms emerging from the skin; all five previous reports of human infection involved surgical removal of worms from the peritoneal cavity. PMID:24379241

Rediscovery and redescription of Leodice laurillardi (Quatrefages, 1866) comb. nov. (Annelida: Eunicidae)-a rare European polychaete or just an overlooked species?

PubMed

Arias, Andrés; Fernández-Álvarez, Fernando Á; Martins, Roberto; Anadón, Nuria

2015-06-04

The eunicid polychaete, Eunice laurillardi Quatrefages, 1866, originally described from the central Mediterranean, has been discovered on the northern Iberian Peninsula, constituting the first report of the species since its original description. The new specimens are compared with the type collection and the species is redescribed. Furthermore, the species is assigned to the genus Leodice Savigny in Lamarck, 1818, based on information provided by re-examination of type material and the newly collected specimens. A summary of the complex taxonomic history of the species and a discussion of its current status are also provided.

Morphological responses of macrobenthic polychaetes to low oxygen on the Oman continental slope, NW Arabian Sea

NASA Astrophysics Data System (ADS)

Lamont, Peter A.; Gage, John D.

2000-01-01

Morphological adaptation to low dissolved oxygen consisting of enlarged respiratory surface area is described in polychaete species belonging to the family Spionidae from the Oman margin where the oxygen minimum zone impinges on the continental slope. Similar adaptation is suggested for species in the family Cossuridae. Such morphological adaptation apparently has not been previously recorded among polychaetes living in hypoxic conditions. The response consists of enlargement in size and branching of the branchiae relative to similar species living in normal levels of dissolved oxygen. Specimens were examined in benthic samples from different depths along a transect through the oxygen minimum zone. There was a highly significant trend shown to increasing respiratory area relative to body size in two undescribed spionid species with decreasing depth and oxygen within the OMZ. Yet the size and number of branchiae are often used as taxonomic characters. These within-species differences in size and number of branchiae may be a direct response by the phenotype to intensity of hypoxia. The alternative explanations are that they either reflect a pattern of differential post-settlement selection among a highly variable genotype, or represent early genetic differentiation among depth-isolated sub-populations.

Individual specialization in a shorebird population with narrow foraging niche

NASA Astrophysics Data System (ADS)

Catry, Teresa; Alves, José A.; Gill, Jennifer A.; Gunnarsson, Tómas G.; Granadeiro, José P.

2014-04-01

Individual specialization in resource use is a widespread driver for intra-population trait variation, playing a crucial evolutionary role in free-living animals. We investigated the individual foraging specialization of Black-tailed Godwits (Limosa limosa islandica) during the wintering period. Godwits displayed distinct degrees of individual specialization in diet and microhabitat use, indicating the presence of both generalist and specialist birds. Females were overall more specialist than males, primarily consuming polychaetes. Specialist males consumed mainly bivalves, but some individuals also specialized on gastropods or polychaetes. Sexual dimorphism in bill length is probably important in determining the differences in specialization, as longer-billed individuals have access to deep-buried polychaetes inaccessible to most males. Different levels of specialization within the same sex, unrelated to bill length, were also found, suggesting that mechanisms other traits are involved in explaining individual specialization. Godwits specialized on bivalves achieved higher intake rates than non-specialist birds, supporting the idea that individual foraging choices or skills result in different short-term payoffs within the same population. Understanding whether short-term payoffs are good indicators of long-term fitness and how selection operates to favour the prevalence of specialist or generalist godwits is a major future challenge.

Genetic diversity of Timarete punctata (Annelida: Cirratulidae): Detection of pseudo-cryptic species and a potential biological invader

NASA Astrophysics Data System (ADS)

Seixas, Victor Corrêa; Zanol, Joana; Magalhães, Wagner F.; Paiva, Paulo Cesar

2017-10-01

Among the processes that drive biological invasions, the presence of asexual reproduction, as observed in many polychaetes, is an important feature because it allows a rapid spread and colonization in the invaded site. Despite its ecological importance for benthic communities, studies on the biological invasive context are rare for this abundant taxon. Here, the phylogeographic pattern of a common asexual reproducer polychaete, Timarete punctata, was analyzed at five sites along the Atlantic and Pacific Oceans to investigate if its wide distribution is associated to human-mediated transport. Sequences of COI and 16S revealed the presence of two cryptic species. One of them exhibits a wide distribution range (∼14,000 km), very low level of genetic diversity and a high frequency of shared haplotypes along sampled sites. The genetic pattern indicates that this species has probably been introduced in all sampled sites, and its wide distribution is associated to human-mediated transport. In addition, the great capability of T. punctata to reproduce by fragmentation makes the colonization process easier. Thus, the number of alien polychaete species is probably underestimated and future studies are necessary to reach a more realistic perspective.

Functional biodiversity of marine soft-sediment polychaetes from two Mediterranean coastal areas in relation to environmental stress.

PubMed

Nasi, F; Nordström, M C; Bonsdorff, E; Auriemma, R; Cibic, T; Del Negro, P

2018-06-01

Biological Traits Analysis (BTA) was used to identify functional features of infaunal polychaete assemblages associated with contamination in two Italian coastal areas: the harbour of Trieste (Adriatic Sea) and the Mar Piccolo of Taranto (Ionian Sea). The analysis was performed on 103 taxa, collected at four stations in each area. The two areas differed in species composition. The low diversity and the presence of stress-tolerant species in more polluted sites were not reflected in functional diversity, due to species contributing little to community functions or being functionally redundant. Sand and clay fractions were significant drivers of trait category expressions, however other environmental parameters (depth, total organic carbon and nitrogen, and Hg in sediments) influenced traits composition. Motile was the prevalent trait in environments with coarse sediments, and tube-builder were related to fine-grained ones. Motile, endobenthic and burrower were essential traits for living in contaminated sediments. Epibenthic and sessile polychaetes dominated at stations subjected to high organic loads. BTA offers an integrative approach to detect functional adaptations to contaminated sediments and multiple anthropogenic stressors. Copyright © 2018 Elsevier Ltd. All rights reserved.

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.

Uptake and loss of dissolved 109Cd and 75Se in estuarine macroinvertebrates.

PubMed

Alquezar, Ralph; Markich, Scott J; Twining, John R

2007-04-01

Semaphore crabs (Heloecius cordiformis), soldier crabs (Mictyris platycheles), ghost shrimps (Trypaea australiensis), pygmy mussels (Xenostrobus securis), and polychaetes (Eunice sp.), key benthic prey items of predatory fish commonly found in estuaries throughout southeastern Australia, were exposed to dissolved (109)Cd and (75)Se for 385 h at 30 k Bq/l (uptake phase), followed by exposure to radionuclide-free water for 189 h (loss phase). The whole body uptake rates of (75)Se by pygmy mussels, semaphore crabs and soldier crabs were 1.9, 2.4 and 4.1 times higher than (109)Cd, respectively. There were no significant (P>0.05) differences between the uptake rates of (75)Se and (109)Cd for ghost shrimps and polychaetes. The uptake rates of (109)Cd and (75)Se were highest in pygmy mussels; about six times higher than in soldier crabs for (109)Cd and in polychaetes for (75)Se - the organisms with the lowest uptake rates. The loss rates of (109)Cd and (75)Se were highest in semaphore crabs; about four times higher than in polychaetes for (109)Cd and nine times higher than in ghost shrimps for (75)Se - the organisms with the lowest loss rates. The loss of (109)Cd and (75)Se in all organisms was best described by a two (i.e. short and a longer-lived) compartment model. In the short-lived, or rapidly exchanging, compartment, the biological half-lives of (75)Se (16-39 h) were about three times greater than those of (109)Cd (5-12h). In contrast, the biological half-lives of (109)Cd in the longer-lived, or slowly exchanging compartment(s), were typically greater (1370-5950 h) than those of (75)Se (161-1500 h). Semaphore crabs had the shortest biological half-lives of both radionuclides in the long-lived compartment, whereas polychaetes had the greatest biological half-life for (109)Cd (5950 h), and ghost shrimps had the greatest biological half-life for (75)Se (1500 h). This study provides the first reported data for the biological half-lives of Se in estuarine decapod crustaceans. Moreover, it emphasises the importance of determining metal(loid) accumulation and loss kinetics in keystone prey items, which consequently influences their trophic transfer potential to higher-order predators.

Microfluidic platform integrated with worm-counting setup for assessing manganese toxicity

PubMed Central

Zhang, Beibei; Li, Yinbao; He, Qidi; Qin, Jun; Yu, Yanyan; Li, Xinchun; Zhang, Lin; Yao, Meicun; Liu, Junshan; Chen, Zuanguang

2014-01-01

We reported a new microfluidic system integrated with worm responders for evaluating the environmental manganese toxicity. The micro device consists of worm loading units, worm observing chambers, and a radial concentration gradient generator (CGG). Eight T-shape worm loading units of the micro device were used to load the exact number of worms into the corresponding eight chambers with the assistance of worm responders and doorsills. The worm responder, as a key component, was employed for performing automated worm-counting assay through electric impedance sensing. This label-free and non-invasive worm-counting technique was applied to the microsystem for the first time. In addition, the disk-shaped CGG can generate a range of stepwise concentrations of the appointed chemical automatically and simultaneously. Due to the scalable architecture of radial CGG, it has the potential to increase the throughput of the assay. Dopaminergic (DAergic) neurotoxicity of manganese on C. elegans was quantitatively assessed via the observation of green fluorescence protein-tagged DAergic neurons of the strain BZ555 on-chip. In addition, oxidative stress triggered by manganese was evaluated by the quantitative fluorescence intensity of the strain CL2166. By scoring the survival ratio and stroke frequency of worms, we characterized the dose- and time-dependent mobility defects of the manganese-exposed worms. Furthermore, we applied the microsystem to investigate the effect of natural antioxidants to protect manganese-induced toxicity. PMID:25538805

Physically disturbed deep-sea macrofauna in the Peru Basin, southeast Pacific, revisited 7 years after the experimental impact

NASA Astrophysics Data System (ADS)

Borowski, Christian

Long-term disturbance effects of a physical disturbance experiment on the benthic macrofauna (>500 μm), with particular emphasis on the dominant Polychaeta, were investigated in connection with the German ATESEPP joint programme in 4150 m depth in the Peru Basin of the tropical southeast (SE) Pacific. The study site was the 10.8 km 2 experimental field of the disturbance and re colonization experiment (DISCOL) conducted in early 1989. This programme had the objective to simulate some of the potential disturbance effects of manganese nodule mining on the bottom-dwelling biota with a towed "plough-harrow" disturber, and subsequently to investigate the resultant community responses with three post-impact samplings during a period of 3 years. Seven years after disturbance, in early 1996, the DISCOL site was revisited, and this study focuses on temporal development of the macrofauna over that extended period. Box core samples obtained during all post-impact expeditions from the disturber tracks ( disturbed treatment) were compared with unploughed sediments from the experimental field ( undisturbed treatment) and with samples from unimpacted sites of the surrounding ( reference treatment). The experiment did not cause the disastrous long-term community changes in the sediment dwelling macrofauna that previously were predicted to follow large-scale disturbances. Abundance recoveries of the macrofaunal taxa were largely terminated after 7 years. Major differences in the faunal compositions at the selected taxonomic levels of higher macrofauna taxa, polychaete families and polychaete species between disturbed and control sites were not observed, but certain disturbance effects remained present over the entire 7-year period: Within-treatment data heterogeneity for the higher macrofauna taxa and the polychaete families was greater in the disturber track samples than in undisturbed and reference treatments. Enhanced heterogeneity was expressed by significantly steeper regression slopes of variance-to-mean ratios of faunal abundances ( p<0.05) and enhanced spatial aggregation at the levels of higher macrofauna taxa and polychaete families. Hurlbert rarefaction E( Sn) and Shannon's diversity index H' calculated in non-standard ways for polychaete species revealed that patterns of diminished "diversity" in the disturbed treatments, which were observed during the later DISCOL period, were still present after 7 years, although the intensity of this signal became weaker. Recent abundance differences between treatments for the Bivalvia, Cumacea and the sigalionid polychaete species Leanira sp. A suggested that unploughed areas from the experimental field possibly were also affected by subtle long-term influences of particle plume settlement caused by the disturber action. A brief comparison with macrofauna abundance data from other ATESEPP sample locations in the Peru Basin revealed highest similarity between the sites located in the manganese nodule province, suggesting that similar disturbance effects can be expected for these areas. Nevertheless, the experimental impact by far did not reach industrial mining impact dimensions and interpretation of the results with regard to commercial mining requires caution.

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.

Glowing Worms: Biological, Chemical, and Functional Diversity of Bioluminescent Annelids.

PubMed

Verdes, Aida; Gruber, David F

2017-07-01

Bioluminescence, the ability to produce light by living organisms, has evolved independently in numerous lineages across the tree of life. Luminous forms are found in a wide range of taxonomic groups from bacteria to vertebrates, although the great majority of bioluminescent organisms are marine taxa. Within the phylum Annelida, bioluminescence is widespread, present in at least 98 terrestrial and marine species that represent 45 genera distributed in thirteen lineages of clitellates and polychaetes. The ecological diversity of luminous annelids is unparalleled, with species occupying a great variety of habitats including both terrestrial and marine ecosystems, from coastal waters to the deep-sea, in benthic and pelagic habitats from polar to tropical regions. This great taxonomic and ecological diversity is matched by the wide array of bioluminescent colors-including yellow light, which is very rare among marine taxa-different emission wavelengths even between species of the same genus, and varying patterns, chemical reactions and kinetics. This diversity of bioluminescence colors and patterns suggests that light production in annelids might be involved in a variety of different functions, including defensive mechanisms like sacrificial lures or aposematic signals, and intraspecific communication systems. In this review, we explore the world of luminous annelids, particularly focusing on the current knowledge regarding their taxonomic and ecological diversity and discussing the putative functions and chemistries of their bioluminescent systems. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology 2017. This work is written by US Government employees and is in the public domain in the US.

EVALUATION OF THE EFFECTS OF COAL FLY ASH AMENDMENTS ON THE TOXICITY OF A CONTAMINATED MARINE SEDIMENT

PubMed Central

Burgess, Robert M.; Perron, Monique M.; Friedman, Carey L.; Suuberg, Eric M.; Pennell, Kelly G.; Cantwell, Mark G.; Pelletier, Marguerite C.; Ho, Kay T.; Serbst, Jonathan R.; Ryba, Stephan A.

2013-01-01

Approaches for cleaning-up contaminated sediments range from dredging to in situ treatment. In the present report, we discuss the effects of amending reference and contaminated sediments with coal fly ash to reduce the bioavailability and toxicity of a field sediment contaminated with polycyclic aromatic hydrocarbons (PAHs). Six fly ashes and a coconut charcoal were evaluated in 7 d whole sediment toxicity tests with a marine amphipod (Ampelisca abdita) and mysid (Americamysis bahia). Fly ashes with high carbon content and the coconut charcoal showed proficiency at reducing toxicity. Some of the fly ashes demonstrated toxicity in the reference treatments. It is suspected that some of this toxicity is related to the presence of ammonia associated with fly ashes as a result of post-oxidation treatment to reduce nitrous oxides emissions. Relatively simple methods exist to remove ammonia from fly ash prior to use and fly ashes with low ammonia content are available. Fly ashes were also shown to effectively reduce overlying water concentrations of several PAHs. There was no evidence of the release of the metals cadmium, copper, nickel or lead from the fly ashes. A preliminary 28 d polychaete bioaccumulation study with one of the high carbon fly ashes and a reference sediment was also performed. Although preliminary, there was no evidence of adverse effects to worm growth or lipid content, or the accumulation of PAHs or mercury from exposure to the fly ash. These data show fly ashes with high carbon contents may represent viable remedial materials for reducing the bioavailability of organic contaminants in sediments. PMID:18717615

Gut Contents as Direct Indicators for Trophic Relationships in the Cambrian Marine Ecosystem

PubMed Central

Vannier, Jean

2012-01-01

Present-day ecosystems host a huge variety of organisms that interact and transfer mass and energy via a cascade of trophic levels. When and how this complex machinery was established remains largely unknown. Although exceptionally preserved biotas clearly show that Early Cambrian animals had already acquired functionalities that enabled them to exploit a wide range of food resources, there is scant direct evidence concerning their diet and exact trophic relationships. Here I describe the gut contents of Ottoia prolifica, an abundant priapulid worm from the middle Cambrian (Stage 5) Burgess Shale biota. I identify the undigested exoskeletal remains of a wide range of small invertebrates that lived at or near the water sediment interface such as hyolithids, brachiopods, different types of arthropods, polychaetes and wiwaxiids. This set of direct fossil evidence allows the first detailed reconstruction of the diet of a 505-million-year-old animal. Ottoia was a dietary generalist and had no strict feeding regime. It fed on both living individuals and decaying organic matter present in its habitat. The feeding behavior of Ottoia was remarkably simple, reduced to the transit of food through an eversible pharynx and a tubular gut with limited physical breakdown and no storage. The recognition of generalist feeding strategies, exemplified by Ottoia, reveals key-aspects of modern-style trophic complexity in the immediate aftermath of the Cambrian explosion. It also shows that the middle Cambrian ecosystem was already too complex to be understood in terms of simple linear dynamics and unique pathways. PMID:23300612

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 ofmore » 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.« less

The Father Christmas worm

NASA Technical Reports Server (NTRS)

Green, James L.; Sisson, Patricia L.

1989-01-01

Given here is an overview analysis of the Father Christmas Worm, a computer worm that was released onto the DECnet Internet three days before Christmas 1988. The purpose behind the worm was to send an electronic mail message to all users on the computer system running the worm. The message was a Christmas greeting and was signed 'Father Christmas'. From the investigation, it was determined that the worm was released from a computer (node number 20597::) at a university in Switzerland. The worm was designed to travel quickly. Estimates are that it was copied to over 6,000 computer nodes. However, it was believed to have executed on only a fraction of those computers. Within ten minutes after it was released, the worm was detected at the Space Physics Analysis Network (SPAN), NASA's largest space and Earth science network. Once the source program was captured, a procedural cure, using the existing functionality of the computer operating systems, was quickly devised and distributed. A combination of existing computer security measures, the quick and accurate procedures devised to stop copies of the worm from executing, and the network itself, were used to rapidly provide the cure. These were the main reasons why the worm executed on such a small percentage of nodes. This overview of the analysis of the events concerning the worm is based on an investigation made by the SPAN Security Team and provides some insight into future security measures that will be taken to handle computer worms and viruses that may hit similar networks.

Design and analysis of SEIQR worm propagation model in mobile internet

NASA Astrophysics Data System (ADS)

Xiao, Xi; Fu, Peng; Dou, Changsheng; Li, Qing; Hu, Guangwu; Xia, Shutao

2017-02-01

The mobile Internet has considerably facilitated daily life in recent years. However, it has become the breeding ground for lots of new worms, including the Bluetooth-based worm, the SMS/MMS-based worm and the Wi-Fi-based worm. At present, Wi-Fi is widely used for mobile devices to connect to the Internet. But it exposes these devices to the dangerous environment. Most current worm propagation models aim to solve the problems of computer worms. They cannot be used directly in the mobile environment, particularly in the Wi-Fi scenario, because of the differences between computers and mobile devices. In this paper, we propose a worm propagation model in the Wi-Fi environment, called SEIQR (Susceptible-Exposed-Infectious- Quarantined-Recovered). In the model, infected nodes can be quarantined by the Wi-Fi base station, and a new state named the Quarantined state (Q) is established to represent these infected nodes. Based on this model, we present an effective method to inhibit the spread of the Wi-Fi-based worms. Furthermore, related stabilities of the worm-free and endemic equilibriums are studied based on the basic reproduction number R0. The worm-free equilibrium is locally and globally asymptotically stable if R0 < 1, whereas the endemic equilibrium is locally asymptotically stable if R0 < 1. Finally, we evaluate the performance of our model by comprehensive experiments with different infection rates and quarantine rates. The results indicate that our mechanism can combat the worms propagated via Wi-Fi.

Towards global Guinea worm eradication in 2015: the experience of South Sudan.

PubMed

Awofeso, Niyi

2013-08-01

For centuries, the Guinea worm parasite (Dracunculus medinensis) has caused disabling misery, infecting people who drink stagnant water contaminated with the worm's larvae. In 2012, there were 542 cases of Guinea worm reported globally, of which 521 (96.1%) were reported in South Sudan. Protracted civil wars, an inadequate workforce, neglect of potable water provision programs, suboptimal Guinea worm surveillance and case containment, and fragmented health systems account for many of the structural and operational factors encumbering South Sudan's Guinea worm eradication efforts. This article reviews the impacts of six established Guinea worm control strategies in South Sudan: (1) surveillance to determine actual caseload distribution and trends in response to control measures; (2) educating community members from whom worms are emerging to avoid immersing affected parts in sources of drinking water; (3) filtering potentially contaminated drinking water using cloth filters or filtered drinking straws; (4) treating potentially contaminated surface water with the copepod larvicide temephos (Abate); (5) providing safe drinking water from boreholes or hand-dug wells; and (6) containment of transmission through voluntary isolation of each patient to prevent contamination of drinking water sources, provision of first aid, and manual extraction of the worm. Surveillance, community education, potable water provision, and case containment remain weak facets of the program. Abate pesticide is not a viable option for Guinea worm control in South Sudan. In light of current case detection and containment trends, as well as capacity building efforts for Guinea worm eradication, South Sudan is more likely to eradicate Guinea worm by 2020, rather than by 2015. The author highlights areas in which substantial improvements are required in South Sudan's Guinea worm eradication program, and suggests improvement strategies. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Cadmium resistance in an oligochaete and its effect on cadmium trophic transfer to an omnivorous shrimp

USGS Publications Warehouse

Wallace, W.G.; Lopez, G.R.; Levinton, J.S.

1998-01-01

It has been demonstrated that the deposit-feeding oligochaete Limnodrilus hoffmeisteri inhabiting Foundry Cove (FC), a severely cadmium (Cd)-contaminated cove located on the Hudson River, New York, USA, has evolved resistance to Cd. In this study we investigate how this resistance influences Cd trophic transfer from this oligochaete to the grass shrimp Palaemonetes pugio. Cadmium-resistant worms collected from FC and nonresistant worms collected from an adjacent unpolluted site were investigated for differences in Cd tolerance, accumulation, subcellular distribution and bioavailability to shrimp. FC worms were more tolerant of Cd, surviving twice as long as worms from the unpolluted site during a toxicity bioassay. The 7 d concentration factor of Cd-resistant worms was 4 times greater than that of nonresistant worms (2020 vs 577). There were also differences between worm populations with respect to subcellular Cd distributions. Cd-resistant worms produced metallothionein-like proteins (MT) as well as metal-rich granules (MRG) for Cd storage and detoxification; nonresistant worms only produced MT. These differences in subcellular Cd distributions led to large differences in Cd bioavailability to shrimp; shrimp fed Cd-resistant worms absorbed 21% of the ingested Cd, while those fed nonresistant worms absorbed roughly 4 times that amount (~75%). These absorption efficiencies were in good agreement with the proportions of Cd bound to the worm's most biologically available subcellular fractions (i.e. the cytosol and organelles). Although Cd-resistant worms predominantly stored the toxic metal in biologically unavailable MRG, their increased accumulation of Cd would still result in substantial trophic transfer to shrimp because of the storage of Cd in the biologically available fractions. This work demonstrates that the evolution of Cd resistance can have profound implications for Cd bioavailability and cycling within aquatic ecosystems.

Routes of uptake of diclofenac, fluoxetine, and triclosan into sediment-dwelling worms.

PubMed

Karlsson, Maja V; Marshall, Stuart; Gouin, Todd; Boxall, Alistair B A

2016-04-01

The present study investigated the route and degree of uptake of 2 ionizable pharmaceuticals (diclofenac and fluoxetine) and 1 ionizable compound used in personal care products (triclosan) into the sediment-dwelling worm Lumbriculus variegatus. Studies were done on complete worms ("feeding") and worms where the head was absent ("nonfeeding") using (14) C-labeled ingredients. Biota sediment accumulation factors (BSAF), based on uptake of (14) C, for feeding worms increased in the order fluoxetine (0.3) < diclofenac (0.5) < triclosan (9), which is correlated with a corresponding increase in log octanol-water partition coefficient. Biota sediment accumulation factor estimates are representative of maximum values because the degree of biotransformation in the worms was not quantified. Although no significant differences were seen between the uptake of diclofenac and that of fluoxetine in feeding and nonfeeding worms, uptake of the more hydrophobic antimicrobial, triclosan, into the feeding worms was significantly greater than that in the nonfeeding worms, with the 48-h BSAF for feeding worms being 36% higher than that for the nonfeeding worms. The results imply that dietary uptake contributes to the uptake of triclosan, which may be a result of the high hydrophobicity of the compound. Models that estimate exposure of ionizable substances may need to consider uptake from both the water column and food, particularly when assessing risks from dynamic exposures to organic contaminants. © 2015 SETAC.

Internal tides affect benthic community structure in an energetic submarine canyon off SW Taiwan

NASA Astrophysics Data System (ADS)

Liao, Jian-Xiang; Chen, Guan-Ming; Chiou, Ming-Da; Jan, Sen; Wei, Chih-Lin

2017-07-01

Submarine canyons are major conduits of terrestrial and shelf organic matter, potentially benefiting the seafloor communities in the food-deprived deep sea; however, strong bottom currents driven by internal tides and the potentially frequent turbidity currents triggered by storm surges, river flooding, and earthquakes may negatively impact the benthos. In this study, we investigated the upper Gaoping Submarine Canyon (GPSC), a high-sediment-yield canyon connected to a small mountain river (SMR) off southwest (SW) Taiwan. By contrasting the benthic meiofaunal and macrofaunal communities within and outside the GPSC, we examined how food supplies and disturbance influenced the benthic community assemblages. The benthic communities in the upper GPSC were mainly a nested subset of the adjacent slope assemblages. Several meiofaunal (e.g. ostracods) and macrofaunal taxa (e.g. peracarid crustaceans and mollusks) that typically occurred on the slope were lost from the canyon. The polychaete families switched from diverse feeding guilds on the slope to motile subsurface deposit feeders dominant in the canyon. The diminishing of epibenthic peracarids and proliferation of deep burrowing polychaetes in the GPSC resulted in macrofauna occurring largely within deeper sediment horizons in the canyon than on the slope. The densities and numbers of taxa were depressed with distinct and more variable composition in the canyon than on the adjacent slope. Both the densities and numbers of taxa were negatively influenced by internal tide flushing and positively influenced by food availability; however, the internal tides also negatively influenced the food supplies. While the meiofauna and macrofauna densities were both depressed by the extreme physical conditions in the GPSC, only the macrofaunal densities increased with depth in the canyon, presumably related to increased frequency and intensity of disturbance toward the canyon head. The population densities of meiofauna, on the other hand, rebounded more rapidly due to their fast growth rate and short generation time and thus did not display bathymetric pattern in the canyon. To our knowledge, this is the first benthic ecological study in a submarine canyon connected to a high-sediment-yield SMR. The biological responses to extreme physical conditions in the GPSC could have broad implications on understanding the anthropogenic and climate change impacts in the deep-sea ecosystems.

The WORM site: worm.csirc.net

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, T.

2000-07-01

The Write One, Run Many (WORM) site (worm.csirc.net) is the on-line home of the WORM language and is hosted by the Criticality Safety Information Resource Center (CSIRC) (www.csirc.net). The purpose of this web site is to create an on-line community for WORM users to gather, share, and archive WORM-related information. WORM is an embedded, functional, programming language designed to facilitate the creation of input decks for computer codes that take standard ASCII text files as input. A functional programming language is one that emphasizes the evaluation of expressions, rather than execution of commands. The simplest and perhaps most common examplemore » of a functional language is a spreadsheet such as Microsoft Excel. The spreadsheet user specifies expressions to be evaluated, while the spreadsheet itself determines the commands to execute, as well as the order of execution/evaluation. WORM functions in a similar fashion and, as a result, is very simple to use and easy to learn. WORM improves the efficiency of today's criticality safety analyst by allowing: (1) input decks for parameter studies to be created quickly and easily; (2) calculations and variables to be embedded into any input deck, thus allowing for meaningful parameter specifications; (3) problems to be specified using any combination of units; and (4) complex mathematically defined models to be created. WORM is completely written in Perl. Running on all variants of UNIX, Windows, MS-DOS, MacOS, and many other operating systems, Perl is one of the most portable programming languages available. As such, WORM works on practically any computer platform.« less

Worm-stars and half-worms: Novel dangers and novel defense.

PubMed

Hodgkin, Jonathan; Clark, Laura C; Gravato-Nobre, Maria J

2014-01-01

In a recent paper, we reported the isolation and surprising effects of two new bacterial pathogens for Caenorhabditis and related nematodes. These two pathogens belong to the genus Leucobacter and were discovered co-infecting a wild isolate of Caenorhabditis that had been collected in Cape Verde. The interactions of these bacteria with C. elegans revealed both unusual mechanisms of pathogenic attack, and an unexpected defense mechanism on the part of the worm. One pathogen, known as Verde1, is able to trap swimming nematodes by sticking their tails together, resulting in the formation of "worm-star" aggregates, within which worms are killed and degraded. Trapped larval worms, but not adults, can sometimes escape by undergoing whole-body autotomy into half-worms. The other pathogen, Verde2, kills worms by a different mechanism associated with rectal infection. Many C. elegans mutants with alterations in surface glycosylation are resistant to Verde2 infection, but hypersensitive to Verde1, being rapidly killed without worm-star formation. Conversely, surface infection of wild-type worms with Verde1 is mildly protective against Verde2. Thus, there are trade-offs in susceptibility to the two bacteria. The Leucobacter pathogens reveal novel nematode biology and provide powerful tools for exploring nematode surface properties and bacterial susceptibility.

Developmental stages of fish blood flukes, Cardicola forsteri and Cardicola opisthorchis (Trematoda: Aporocotylidae), in their polychaete intermediate hosts collected at Pacific bluefin tuna culture sites in Japan.

PubMed

Ogawa, Kazuo; Shirakashi, Sho; Tani, Kazuki; Shin, Sang Phil; Ishimaru, Katsuya; Honryo, Tomoki; Sugihara, Yukitaka; Uchida, Hiro'omi

2017-02-01

Farming of Pacific bluefin tuna (PBT), Thunnus orientalis, is a rapidly growing industry in Japan. Aporocotylid blood flukes of the genus Cardicola comprising C. orientalis, C. opisthorchis and C. forsteri are parasites of economic importance for PBT farming. Recently, terebellid polychaetes have been identified as the intermediate hosts for all these parasites. We collected infected polychaetes, Terebella sp., the intermediate host of C. opisthorchis, from ropes and floats attached to tuna cages in Tsushima, Nagasaki Prefecture, Japan. Also, Neoamphitrite vigintipes (formerly as Amphitrite sp. sensu Shirakashi et al., 2016), the intermediate host of C. forsteri, were collected from culture cages in Kushimoto, Wakayama Prefecture, Japan. The terebellid intermediate hosts harbored the sporocysts and cercariae in their body cavity. Developmental stages of these blood flukes were molecularly identified using species specific PCR primers. In this paper, we describe the cercaria and sporocyst stages of C. opisthorchis and C. forsteri and compare their morphological characteristics among three Cardicola blood flukes infecting PBT. We also discuss phylogenetic relations of the six genera of the terebellid intermediate hosts (Artacama, Lanassa, Longicarpus, Terebella, Nicolea and Neoamphitrite) of blood flukes infecting marine fishes, based on their morphological characters. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

In situ effects of simulated overfishing and eutrophication on settlement of benthic coral reef invertebrates in the Central Red Sea

PubMed Central

Voolstra, Christian R.; Wild, Christian

2014-01-01

In the Central Red Sea, healthy coral reefs meet intense coastal development, but data on the effects of related stressors for reef functioning are lacking. This in situ study therefore investigated the independent and combined effects of simulated overfishing through predator/grazer exclusion and simulated eutrophication through fertilizer addition on settlement of reef associated invertebrates on light-exposed and -shaded tiles over 4 months. At the end of the study period invertebrates had almost exclusively colonized shaded tiles. Algae were superior settling competitors on light-exposed tiles. On the shaded tiles, simulated overfishing prevented settlement of hard corals, but significantly increased settlement of polychaetes, while simulated eutrophication only significantly decreased hard coral settlement relative to controls. The combined treatment significantly increased settlement of bryozoans and bivalves compared to controls and individual manipulations, but significantly decreased polychaetes compared to simulated overfishing. These results suggest settlement of polychaetes and hard corals as potential bioindicators for overfishing and eutrophication, respectively, and settlement of bivalves and bryozoans for a combination of both. Therefore, if the investigated stressors are not controlled, phase shifts from dominance by hard corals to that by other invertebrates may occur at shaded reef locations in the Central Red Sea. PMID:24765573

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.

In situ effects of simulated overfishing and eutrophication on settlement of benthic coral reef invertebrates in the Central Red Sea.

PubMed

Jessen, Christian; Voolstra, Christian R; Wild, Christian

2014-01-01

In the Central Red Sea, healthy coral reefs meet intense coastal development, but data on the effects of related stressors for reef functioning are lacking. This in situ study therefore investigated the independent and combined effects of simulated overfishing through predator/grazer exclusion and simulated eutrophication through fertilizer addition on settlement of reef associated invertebrates on light-exposed and -shaded tiles over 4 months. At the end of the study period invertebrates had almost exclusively colonized shaded tiles. Algae were superior settling competitors on light-exposed tiles. On the shaded tiles, simulated overfishing prevented settlement of hard corals, but significantly increased settlement of polychaetes, while simulated eutrophication only significantly decreased hard coral settlement relative to controls. The combined treatment significantly increased settlement of bryozoans and bivalves compared to controls and individual manipulations, but significantly decreased polychaetes compared to simulated overfishing. These results suggest settlement of polychaetes and hard corals as potential bioindicators for overfishing and eutrophication, respectively, and settlement of bivalves and bryozoans for a combination of both. Therefore, if the investigated stressors are not controlled, phase shifts from dominance by hard corals to that by other invertebrates may occur at shaded reef locations in the Central Red Sea.

Polychaeta (Annelida) associated with Thalassia testudinum in the northeastern coastal waters of Venezuela.

PubMed

Liñero Arana, Ildefonso; Díaz Díaz, Oscar

2006-09-01

Seasonal variations of polychaetes in a Thalassia testudinum bed were studied from June 2000 to April 2001 in Chacopata, northeastern Venezuela. Eight replicate samples were taken monthly with a 15 cm diameter core and the sediment was passed through a 0.5 mm mesh sieve. A total of 1,013 specimens, belonging to 35 species, was collected. The monthly density ranged from 387 ind/m2 (September) to 1,735 ind/m2 in May (x = 989+/-449 ind/m2). Species richness was lowest in August and September (8) and highest (25) in April (x = 18.00+/-5.29). The shoot density of Thalassia showed an average of 284+/-77.60 shoots/m2, with extreme values in February (164) and May (422). Species diversity ranged from 1.25 in August and 3.33 bits/ind in December (x = 2.47+/-0.64). Significant positive correlations were detected among the number of Thalassia shoots, polychaete abundance and species richness, as well as among species richness, polychaete abundance and species diversity. Species number and average density were found within the intervals of mean values reported in similar studies. The higher number of species and organisms obtained in March-April and June-July can be attributed to the recruitment correlated with the regional up-welling.

21 CFR 520.45b - Albendazole paste.

Code of Federal Regulations, 2012 CFR

2012-04-01

... (Fasciola hepatica); heads and segments of tapeworms (Moniezia benedeni, M. expansa); adult and 4th stage larvae of stomach worms (brown stomach worms including 4th stage inhibited larvae (Ostertagia ostertagi); barberpole worm (Haemonchus contortus, H. placei); small stomach worm (Trichostrongylus axei)); adult and 4th...

Diversity of the benthic macrofauna off northern Namibia from the shelf to the deep sea

NASA Astrophysics Data System (ADS)

Eisenbarth, Simone; Zettler, Michael L.

2016-03-01

In late summer 2011, shortly after an upwelling event, 17 stations ranging from 30 to 2513 m water depth have been sampled at 20° south in the northern part of the Benguela Current Large Marine Ecosystem (BCLME) for the investigation of the benthic macrofauna. Sediments of this area are dominated by silt. At the time of sampling, oxygen conditions on the shelf were poor (between 0.42 and 0.68 ml l- 1) but not hypoxic. Below 400 m, however, concentrations rose steadily up to 5.28 ml l- 1. Macrozoobenthic communities along this depth gradient are described, revealing among others the community structure for the continental margin area and the deep sea off northern Namibia for the first time. Cluster analysis revealed 5 different communities along the depth gradient with three shelf communities, one continental margin community and one deep-sea community. All in all, 314 different taxa were found with polychaetes being the most abundant group. Diversity index (Shannon) was lowest for the shallow water community with 2.21 and highest for the deep-sea community with 4.79, showing a clear trend with increasing water depth. Species richness, however, reached its maximum with 187 taxa along the continental margin between 400 and 1300 m water depth. Dominant species for each community are named with the two Cumacea, Iphinoeafricana and Upselaspis caparti, being characteristic for the shallow water community. On the shelf, we found surprisingly high biomass values (23-123 g m- 2), mainly caused by polychaetes, the bivalve Sinupharus galatheae and the gastropod Nassarius vinctus. In terms of composition, the remaining communities were dominated by polychaetes with members of the Paraonidae dominating along the continental margin where we also found surprisingly high abundances of the bivalves Pecten sp. and Dosinia sp. Spionid polychaetes and some representatives of the genus Paraonis were the most common organisms for the deep-sea community.

Diurnal migration of Echinostoma caproni (Digenea: Echinostomatidae) in ICR mice.

PubMed

Platt, Thomas R; Graf, Emily; Kammrath, Anna; Zelmer, Derek A

2010-12-01

Twenty-four female ICR mice, 12 acclimated to a 12 ∶ 12 light-dark cycle and 12 to a 12 ∶ 12 dark-light cycle for 7 days, were each infected with 10 metacercariae of Echinostoma caproni. Infected mice were maintained on their respective lighting regimes for 28 days. Six mice (3 from each group) were necropsied at 4-hr intervals beginning at 0700 hr. The small intestine was removed, opened, and the position of individual worms and worm clusters was measured to the nearest 0.1 cm. Each intestine was subsequently divided into 20 equal segments and individual worms and worm clusters were assigned to the appropriate segment based on the original measurements. All worms were found in the posterior 55% of the intestine (ileum). All posterior segments (10-20), with the exception of segment 18, harbored at least 1 worm at some time. A Monte Carlo simulation of worm abundance in segments 10-17 over all time periods indicated a random distribution, while the same analysis of segments 10-20 indicated a non-random distribution due to large numbers of worms in segment 20 and to the absence of worms in segment 18. To analyze temporal changes in worm distribution, mice were grouped by time of necropsy as follows: night (1900 and 2300 hr), morning (0300 and 0700 hr), and day (1100 and 1500 hr). During the night and morning, E. caproni was heavily concentrated in segments 10-17 and, during the day, worms were located more posteriorly, with a heavy concentration in the last segment (20).

High-Fidelity Modeling of Computer Network Worms

DTIC Science & Technology

2004-06-22

plots the propagation of the TCP-based worm. This execution is among the largest TCP worm models simulated to date at packet-level. TCP vs . UDP Worm...the mapping of the virtual IP addresses to honeyd’s MAC address in the proxy’s ARP table. The proxy server listens for packets from both sides of...experimental setup, we used two ntium-4 ThinkPad , and an IBM Pentium-III ThinkPad ), running the proxy server and honeyd respectively. The Code Red II worm

Near-Field Receiving Water Monitoring of Trace Metals and a Benthic Community Near the Palo Alto Regional Water Quality Control Plant in South San Francisco Bay, California: 2007

USGS Publications Warehouse

Lorenzi, Allison H.; Cain, Daniel J.; Parcheso, Francis; Thompson, Janet K.; Luoma, Samuel N.; Hornberger, Michelle I.; Dyke, Jessica

2008-01-01

Results reported herein include trace element concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica (Cohen and Carlton 1995)), clam reproductive activity, and benthic macroinvertebrate community structure for a mudflat one kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant in South San Francisco Bay. This report includes data collected for the period January 2007 to December 2007, and extends a critical long-term biogeochemical record dating back to 1974. These data serve as the basis for the City of Palo Alto?s Near-Field Receiving Water Monitoring Program, initiated in 1994. Metal concentrations in both sediments and clam tissue during 2007 remained consistent with results observed since 1990. Most notably, copper and silver concentrations in sediment and clam tissue are elevated for the second consecutive year, but the values remain well within the range of past findings. Other metals such as chromium, nickel, vanadium, and zinc remained relatively constant throughout the year except for maximum values that generally occur in winter months (January-March). Mercury levels in sediment and clam tissue were some of the lowest seen on record. Last year?s elevated selenium levels appear to be transient, and selenium concentrations have returned to background levels. Overall, metal concentrations in sediments and tissue remain within past findings. Analyses of the benthic-community structure of a mudflat in South San Francisco Bay over a 31-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinel clam, M. petalum, from the same area. Analysis of the reproductive activity of M. petalum shows increases in reproductive activity concurrent with the decline in metal concentrations in the tissues of this organism. Reproductive activity is presently stable, with almost all animals initiating reproduction in the fall and spawning the following spring of most years. The community has shifted from being dominated by several opportunistic species to a community where the species are more similar in abundance, a pattern that suggests a more stable community that is subjected to less stress. In addition, two of the opportunistic species (Ampelisca abdita and Streblospio benedicti) that brood their young and live on the surface of the sediment in tubes, have shown a continual decline in dominance coincident with the decline in metals. Heteromastus filiformis, a subsurface polychaete worm that lives in the sediment, consumes sediment and organic particles residing in the sediment, and reproduces by laying their eggs on or in the sediment, has shown a concurrent increase in dominance and is now showing signs of population stability. These changes in species dominance reflect a change in the community from one dominated by surface dwelling, brooding species to one with species with varying life history characteristics.

Lifespan-on-a-chip: microfluidic chambers for performing lifelong observation of C. elegans†

PubMed Central

Hulme, S. Elizabeth; Shevkoplyas, Sergey S.; McGuigan, Alison P.; Apfeld, Javier; Fontana, Walter

2011-01-01

This article describes the fabrication of a microfluidic device for the liquid culture of many individual nematode worms (Caenorhabditis elegans) in separate chambers. Each chamber houses a single worm from the fourth larval stage until death, and enables examination of a population of individual worms for their entire adult lifespans. Adjacent to the chambers, the device includes microfluidic worm clamps, which enable periodic, temporary immobilization of each worm. The device made it possible to track changes in body size and locomotion in individual worms throughout their lifespans. This ability to perform longitudinal measurements within the device enabled the identification of age-related phenotypic changes that correlate with lifespan in C. elegans. PMID:20162234

Diversity of Sternaspidae (Annelida: Terebellida) in the South China Sea, with descriptions of four new species.

PubMed

Wu, Xuwen; Xu, Kuidong

2017-03-20

Sternaspidae is one of the most common groups of polychaetes in the South China Sea, where however, the knowledge of its diversity and distribution is insufficiently understood and reports of the European species Sternaspis scutata are misidentifications. Based on the examination of material deposited in the Marine Biological Museum of the Chinese Academy of Sciences, we made a comprehensive investigation on the sternaspid polychaetes in the northern South China Sea. Five species belonging to two genera are described: Petersenaspis salazari sp. nov., Sternaspis radiata sp. nov., S. spinosa Sluiter, 1882, S. sunae sp. nov. and S. wui sp. nov. A taxonomic key to ten species of Sternaspidae found in the South China Sea is provided.

Microplastics reduced posterior segment regeneration rate of the polychaete Perinereis aibuhitensis.

PubMed

Leung, Julia; Chan, Kit Yu Karen

2018-04-01

Microplastics are found in abundance in and on coastal sediments, and yet, whether exposure to this emerging pollutant negatively impact whole organism function is unknown. Focusing on a commercially important polychaete, Perinereis aibuhitensis, we demonstrated that presence of microplastics increased mortality and reduced the rate of posterior segment regeneration. The impact of the micro-polystyrene beads was size-dependent with smaller beads (8-12μm in diameter) being more detrimental than those bigger in size (32-38μm). This observed difference suggests microplastic impact could be affected by physical properties, e.g., sinking speed, surface area available for sorption of chemicals and bacteria, and selective feeding behaviors of the target organism. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chemistry and the worm: Caenorhabditis elegans as a platform for integrating chemical and biological research.

PubMed

Hulme, S Elizabeth; Whitesides, George M

2011-05-16

This Review discusses the potential usefulness of the worm Caenorhabditis elegans as a model organism for chemists interested in studying living systems. C. elegans, a 1 mm long roundworm, is a popular model organism in almost all areas of modern biology. The worm has several features that make it attractive for biology: it is small (<1000 cells), transparent, and genetically tractable. Despite its simplicity, the worm exhibits complex phenotypes associated with multicellularity: the worm has differentiated cells and organs, it ages and has a well-defined lifespan, and it is capable of learning and remembering. This Review argues that the balance between simplicity and complexity in the worm will make it a useful tool in determining the relationship between molecular-scale phenomena and organism-level phenomena, such as aging, behavior, cognition, and disease. Following an introduction to worm biology, the Review provides examples of current research with C. elegans that is chemically relevant. It also describes tools-biological, chemical, and physical-that are available to researchers studying the worm. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cuticular surface damage of Ascaridia galli adult worms treated with Veitchia merrillii betel nuts extract in vitro.

PubMed

Balqis, Ummu; Hambal, Muhammad; Rinidar; Athaillah, Farida; Ismail; Azhar; Vanda, Henni; Darmawi

2017-07-01

The objective of this research was to in vitro evaluate the cuticular surface damage of Ascaridia galli adult worms treated with ethanolic extract of betel nuts Veitchia merrillii . Phytochemical screening was done using FeCl 3 , Wagner and Dragendorff reagents, NaOH, MgHCl, and Liebermann-Burchard reaction test. Amount of 16 worms were segregated into four groups with three replicates. Four worms of each group submerged into phosphate buffered saline, 25 mg/ml, and 75 mg/ml crude ethanolic extract of V. merrillii , and 15 mg/ml albendazole. The effect of these extract was observed 40 h after incubation as soon as worms death. The worms were sectioned transversally and were explored for any cuticular histopathological changes in their body surface under microscope. We found that the ethanolic extract of V. merrillii betel nuts contains tannins, alkaloids, flavonoids, triterpenoids, and saponins. The ethanolic extract of betel nuts V. merrillii induces surface alterations caused cuticular damage of A. galli adult worms. We concluded that ethanolic extract of betel nuts V. merrillii possess anthelmintic activity caused cuticular damage of A. galli adult worms.

A calibration mechanism based on worm drive for space telescope

NASA Astrophysics Data System (ADS)

Chong, Yaqin; Li, Chuang; Xia, Siyu; Zhong, Peifeng; Lei, Wang

2017-08-01

In this paper, a new type of calibration mechanism based on worm drive is presented for a space telescope. This calibration mechanism based on worm drive has the advantages of compact size and self-lock. The mechanism mainly consists of thirty-six LEDs as the light source for flat calibration, a diffuse plate, a step motor, a worm gear reducer and a potentiometer. As the main part of the diffuse plate, a PTFE tablet is mounted in an aluminum alloy frame. The frame is fixed on the shaft of the worm gear, which is driven by the step motor through the worm. The shaft of the potentiometer is connected to that of the worm gear to measure the rotation angle of the diffuse plate through a flexible coupler. Firstly, the calibration mechanism is designed, which includes the LEDs assembly design, the worm gear reducer design and the diffuse plate assembly design. The counterweight blocks and two end stops are also designed for the diffuse plate assembly. Then a modal analysis with finite element method for the diffuse plate assembly is completed.

Ecotoxicity testing and environmental risk assessment of iron nanomaterials for sub-surface remediation - Recommendations from the FP7 project NanoRem.

PubMed

Hjorth, Rune; Coutris, Claire; Nguyen, Nhung H A; Sevcu, Alena; Gallego-Urrea, Juliàn Alberto; Baun, Anders; Joner, Erik J

2017-09-01

Nanoremediation with iron (Fe) nanomaterials opens new doors for treating contaminated soil and groundwater, but is also accompanied by new potential risks as large quantities of engineered nanomaterials are introduced into the environment. In this study, we have assessed the ecotoxicity of four engineered Fe nanomaterials, specifically, Nano-Goethite, Trap-Ox Fe-zeolites, Carbo-Iron ® and FerMEG12, developed within the European FP7 project NanoRem for sub-surface remediation towards a test battery consisting of eight ecotoxicity tests on bacteria (V. fisheri, E. coli), algae (P. subcapitata, Chlamydomonas sp.), crustaceans (D. magna), worms (E. fetida, L. variegatus) and plants (R. sativus, L. multiflorum). The tested materials are commercially available and include Fe oxide and nanoscale zero valent iron (nZVI), but also hybrid products with Fe loaded into a matrix. All but one material, a ball milled nZVI (FerMEG12), showed no toxicity in the test battery when tested in concentrations up to 100 mg/L, which is the cutoff for hazard labeling in chemicals regulation in Europe. However it should be noted that Fe nanomaterials proved challenging to test adequately due to their turbidity, aggregation and sedimentation behavior in aqueous media. This paper provides a number of recommendations concerning future testing of Fe nanomaterials and discusses environmental risk assessment considerations related to these. Copyright © 2017 Elsevier Ltd. All rights reserved.

Inheritance of mercury tolerance in the aquatic oligochaete Tubifex tubifex.

PubMed

Vidal, Dora Elva; Horne, Alex John

2003-09-01

Resistance to contaminants is an important yet unmeasured factor in sediment toxicity tests. The rate at which mercury resistance develops and its genetic persistence in the oligochaete worm Tubifex tubifex were studied under laboratory conditions. Worms were raised for four generations under two different sediment treatments, one reference clean sediment, the other contaminated with mercury. Worms raised in mercury-contaminated sediment developed mercury tolerance that persisted even when the worms were raised for three subsequent generations in clean sediment. Mercury tolerance was determined by comparative water-only toxicity tests with mercury as the only stressor. Control worms had a mean lethal concentration (LC50) of 0.18 mg/L(-1). Worms exposed to high levels of mercury in sediment had high mercury tolerance with a mean LC50 of 1.40 mg/L(-1). When mercury-tolerant and control mercury-intolerant worms were crossed, their descendants also demonstrated mercury tolerance during lethal toxicity tests. The LC50 for worm descendants resulting from this cross was 1.39 mg/L(-1). Adaptation to mercury exposures occurred rapidly in this group of worms and appears to be due to both phenotypic and genotypic mechanisms. Development of contaminant resistance and adaptation may be common phenomena in aquatic benthic invertebrates, which should be considered during the design and interpretation of toxicity tests.

Effects of water temperature and substrate type on spore production and release in eastern Tubifex tubifex worms infected with Myxobolus cerebralis

USGS Publications Warehouse

Blazer, V.S.; Waldrop, T.B.; Schill, W.B.; Densmore, Christine L.; Smith, D.

2003-01-01

Eastern Tubifex tubifex worms were exposed to Myxobolus cerebralis spores at 9, 13, 17, and 20 C in 1-L jars that contained sand, mud, or leaf litter as substrata. Beginning 60 days after exposure, water from each jar was filtered daily and examined for the presence of waterborne triactinomyxon spores (TAMs). On discovering a single TAM from an experimental jar, 48 T. tubifex worms from that jar were placed individually into 24-well plates. Spores released from individual infected T. tubifex worms were quantified to determine the first day of TAM release from infected worms, the infection rate, the total number of TAMs released per worm, and the duration of release. No TAMs were found in any of the jars incubated at 20 C or in uninfected, control worms at any temperature. The total number of TAMs released by infected worms in mud and sand was highest at 13 C compared with other temperatures. Infection rates among individual worms increased with temperature between 9 and 17 C. Higher temperatures (up to 17 C) induced earlier TAM releases among infected worms, and substratum did not influence this production parameter. The average duration of TAM release decreased as the temperature increased from 9 to 17 C, and there was a significant effect of substratum in the groups maintained at 13 and 17 C. In all temperature treatments between 9 and 17 C, the duration of release was least in the worms maintained in leaf litter, as was the total number of TAMs released during the experimental period and the median number of TAMs per production day.

Two Leucobacter Strains Exert Complementary Virulence on Caenorhabditis Including Death by Worm-Star Formation

PubMed Central

Hodgkin, Jonathan; Félix, Marie-Anne; Clark, Laura C.; Stroud, Dave; Gravato-Nobre, Maria J.

2013-01-01

Summary The nematode Caenorhabditis elegans has been much studied as a host for microbial infection. Some pathogens can infect its intestine [1, 2], while others attack via its external surface [1, 3–6]. Cultures of Caenorhabditis isolated from natural environments have yielded new nematode pathogens, such as microsporidia and viruses [7, 8]. We report here a novel mechanism for bacterial attack on worms, discovered during investigation of a diseased and coinfected natural isolate of Caenorhabditis from Cape Verde. Two related coryneform pathogens (genus Leucobacter) were obtained from this isolate, which had complementary effects on C. elegans and related nematodes. One pathogen, Verde1, was able to cause swimming worms to stick together irreversibly by their tails, leading to the rapid formation of aggregated “worm-stars.” Adult worms trapped in these aggregates were immobilized and subsequently died, with concomitant growth of bacteria. Trapped larval worms were sometimes able to escape from worm-stars by undergoing autotomy, separating their bodies into two parts. The other pathogen, Verde2, killed worms after rectal invasion, in a more virulent version of a previously studied infection [6]. Resistance to killing by Verde2, by means of alterations in host surface glycosylation, resulted in hypersensitivity to Verde1, revealing a trade-off in bacterial susceptibility. Conversely, a sublethal surface infection of worms with Verde1 conferred partial protection against Verde2. The formation of worm-stars by Verde1 occurred only when worms were swimming in liquid but provides a striking example of asymmetric warfare as well as a bacterial equivalent to the trapping strategies used by nematophagous fungi [4]. PMID:24206844

Two Leucobacter strains exert complementary virulence on Caenorhabditis including death by worm-star formation.

PubMed

Hodgkin, Jonathan; Félix, Marie-Anne; Clark, Laura C; Stroud, Dave; Gravato-Nobre, Maria J

2013-11-04

The nematode Caenorhabditis elegans has been much studied as a host for microbial infection. Some pathogens can infect its intestine, while others attack via its external surface. Cultures of Caenorhabditis isolated from natural environments have yielded new nematode pathogens, such as microsporidia and viruses. We report here a novel mechanism for bacterial attack on worms, discovered during investigation of a diseased and coinfected natural isolate of Caenorhabditis from Cape Verde. Two related coryneform pathogens (genus Leucobacter) were obtained from this isolate, which had complementary effects on C. elegans and related nematodes. One pathogen, Verde1, was able to cause swimming worms to stick together irreversibly by their tails, leading to the rapid formation of aggregated "worm-stars." Adult worms trapped in these aggregates were immobilized and subsequently died, with concomitant growth of bacteria. Trapped larval worms were sometimes able to escape from worm-stars by undergoing autotomy, separating their bodies into two parts. The other pathogen, Verde2, killed worms after rectal invasion, in a more virulent version of a previously studied infection. Resistance to killing by Verde2, by means of alterations in host surface glycosylation, resulted in hypersensitivity to Verde1, revealing a trade-off in bacterial susceptibility. Conversely, a sublethal surface infection of worms with Verde1 conferred partial protection against Verde2. The formation of worm-stars by Verde1 occurred only when worms were swimming in liquid but provides a striking example of asymmetric warfare as well as a bacterial equivalent to the trapping strategies used by nematophagous fungi. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

A full scale worm reactor for efficient sludge reduction by predation in a wastewater treatment plant.

PubMed

Tamis, J; van Schouwenburg, G; Kleerebezem, R; van Loosdrecht, M C M

2011-11-15

Sludge predation can be an effective solution to reduce sludge production at a wastewater treatment plant. Oligochaete worms are the natural consumers of biomass in benthic layers in ecosystems. In this study the results of secondary sludge degradation by the aquatic Oligochaete worm Aulophorus furcatus in a 125 m(3) reactor and further sludge conversion in an anaerobic tank are presented. The system was operated over a period of 4 years at WWTP Wolvega, the Netherlands and was fed with secondary sludge from a low loaded activated sludge process. It was possible to maintain a stable and active population of the aquatic worm species A. furcatus during the full period. Under optimal conditions a sludge conversion of 150-200 kg TSS/d or 1.2-1.6 kg TSS/m(3)/d was established in the worm reactor. The worms grew as a biofilm on carrier material in the reactor. The surface specific conversion rate reached 140-180 g TSS/m(2)d and the worm biomass specific conversion rate was 0.5-1 g TSS sludge/g dry weight worms per day. The sludge reduction under optimal conditions in the worm reactor was 30-40%. The degradation by worms was an order of magnitude larger than the endogenous conversion rate of the secondary sludge. Effluent sludge from the worm reactor was stored in an anaerobic tank where methanogenic processes became apparent. It appeared that besides reducing the sludge amount, the worms' activity increased anaerobic digestibility, allowing for future optimisation of the total system by maximising sludge reduction and methane formation. In the whole system it was possible to reduce the amount of sludge by at least 65% on TSS basis. This is a much better total conversion than reported for anaerobic biodegradability of secondary sludge of 20-30% efficiency in terms of TSS reduction. Copyright © 2011 Elsevier Ltd. All rights reserved.

Goblet cell mucins as the selective barrier for the intestinal helminths: T-cell-independent alteration of goblet cell mucins by immunologically 'damaged' Nippostrongylus brasiliensis worms and its significance on the challenge infection with homologous and heterologous parasites.

PubMed Central

Ishikawa, N; Horii, Y; Oinuma, T; Suganuma, T; Nawa, Y

1994-01-01

The aim of this study was to examine the role of T cells on the alteration of terminal sugars of goblet cell mucins in the small intestinal mucosa of parasitized rats and to clarify the biological significance of the altered mucins in the mucosal defence against intestinal helminths. For this purpose, Nippostrongylus brasiliensis adult worms obtained from donor rats at 7 ('normal' worms) or 13 days ('damaged' worms) post-infection were implanted intraduodenally into euthymic and hypothymic (rnu/rnu) rats. Expulsion of implanted normal worms and associated goblet cell changes were extremely delayed in hypothymic recipients compared with euthymic recipients. In contrast, intraduodenally implanted damaged worms were expelled by day 5 regardless of the strains. Around the time of expulsion of implanted damaged worms, euthymic recipients showed both goblet cell hyperplasia and alteration of mucins, whereas hypothymic rats showed only the latter. Dexamethasone treatment completely abolished goblet cell changes of both strains of recipients. To clarify the importance of the constitutional changes of goblet cell mucins in mucosal defence, euthymic rats were primed by implantation of damaged worms to induce goblet cell changes, and then 3 or 5 days later they were challenged by implantation with normal worms. The results show that when goblet cell changes were induced by priming with damaged worms, recipient rats could completely prevent the establishment of normal worms. When hypothymic rats were primed and challenged in the same manner, a similar but slightly less preventive effect was observed. Such a protective effect of altered mucins seems to be selective because priming of euthymic rats with damaged N. brasiliensis did not affect the establishment of Strongyloides venezuelensis. These results suggest that: (1) once N. brasiliensis adult worms are 'damaged' by the host's T-cell-dependent immune mechanisms, they can induce alteration of sugar residues of goblet cell mucins via host-mediated, T-cell-independent processes; (2) the expression of such altered mucins is highly effective not only in causing expulsion of established damaged worms but also in preventing establishment of normal worms; and (3) the preventive effect of altered mucins is selective against parasite species. Images Figure 2 Figure 4 PMID:8206520

The occurrence of gizzard worms in Canada geese

USGS Publications Warehouse

Herman, C.M.; Wehr, E.E.

1954-01-01

Amidostomum anseris, a roundworm which occurs under the horny lining of the gizzard in birds, is a widely distributed parasite in Canada geese. It is also reported from snow geese (Chen hyperborea). Although the extent of erosion of the gizzard wall by these worms is not precisely correlated with the number of worms present, it is usually severe in Canada geese when 150 or more worms are present. Gizzard worm infection is considered a contributing factor to low weights, poor condition and to losses among the Canada geese which winter at the Pea Island National Wildlife Refuge in North Carolina. The mean number of gizzard worms per bird is considerably higher for Pea Island than for areas where winter losses have not been reported.

Spatio-temporal biodiversity of soft bottom macrofaunal assemblages in shallow coastal waters exposed to episodic hypoxic events.

PubMed

Veas, Rodrigo; Hernández-Miranda, Eduardo; Quiñones, Renato A; Carrasco, Franklin D

2012-07-01

The Humboldt Current System (HCS) has one of the three most important oxygen minimum zones (OMZ) of the global ocean. Several studies have looked at the macrofaunal benthic assemblages inhabiting the continental shelf and shallow bays off central-southern Chile associated with low oxygen areas, but little is known about open coast macrofaunal communities within this zone, which are frequently subjected to the low oxygen conditions of Equatorial Subsurface Waters (ESSW). In order to assess local and mesoscale coastal macrofauna dynamics, the sampling area (ca. 40 linear km) was divided into seven local zones (Cobquecura, southern Cobquecura, northern Itata, Itata River mouth, external, southern Itata, and Coliumo). Eight oceanographic cruises were carried out between May 2006 and February 2008 covering 16 coastal sampling sites, between 36°07'S and 36°30'S. The macrofaunal assemblage was dominated by polychaetes, crustaceans, and mollusks. Our results suggest a high degree of temporal faunal stability on the mesoscale in soft bottom communities along the open coast, given the persistence of a faunal assemblage dominated by organisms tolerant of low oxygen conditions. While there is some local variability in community attributes, the main structuring factor for soft bottom communities in the shallow coastal area off central-southern Chile is the seasonal intrusion of low oxygen ESSW. Copyright © 2012 Elsevier Ltd. All rights reserved.

Using Stable Isotope Compositions of Animal Tissues to Infer Trophic Interactions in Gulf of Mexico Lower Slope Seep Communities

PubMed Central

Becker, Erin L.; Cordes, Erik E.; Macko, Stephen A.; Lee, Raymond W.; Fisher, Charles R.

2013-01-01

We analyzed the tissue carbon, nitrogen, and sulfur stable isotope contents of macrofaunal communities associated with vestimentiferan tubeworms and bathymodiolin mussels from the Gulf of Mexico lower continental slope (970-2800 m). Shrimp in the genus Alvinocaris associated with vestimentiferans from shallow (530 m) and deep (1400-2800 m) sites were used to test the hypothesis that seep animals derive a greater proportion of their nutrition from seeps (i.e. a lower proportion from the surface) at greater depths. To account for spatial variability in the inorganic source pool, we used the differences between the mean tissue δ13C and δ15N of the shrimp in each collection and the mean δ 13C and δ15N values of the vestimentiferans from the same collection, since vestimentiferans are functionally autotrophic and serve as a baseline for environmental isotopic variation. There was a significant negative relationship between this difference and depth for both δ13C and δ15N (p=0.02 and 0.007, respectively), which supports the hypothesis of higher dependence on seep nutrition with depth. The small polychaete worm Protomystides sp. was hypothesized to be a blood parasite of the vestimentiferan Escarpialaminata . There was a highly significant linear relationship between the δ13C values of Protomystides sp. and the E . laminata individuals to which they were attached across all collections (p < 0.001) and within a single collection (p = 0.01), although this relationship was not significant for δ15N and δ34S. We made several other qualitative inferences with respect to the feeding biology of the taxa occurring in these lower slope seeps, some of which have not been described prior to this study. PMID:24324572

Long-term (1993-2013) changes in macrozooplankton off the Western Antarctic Peninsula

NASA Astrophysics Data System (ADS)

Steinberg, Deborah K.; Ruck, Kate E.; Gleiber, Miram R.; Garzio, Lori M.; Cope, Joseph S.; Bernard, Kim S.; Stammerjohn, Sharon E.; Schofield, Oscar M. E.; Quetin, Langdon B.; Ross, Robin M.

2015-07-01

The Western Antarctic Peninsula (WAP) is one of the most rapidly warming regions on Earth, and where a high apex predator biomass is supported in large part by macrozooplankton. We examined trends in summer (January-February) abundance of major taxa of macrozooplankton along the WAP over two decades (1993-2013) and their relationship with environmental parameters (sea ice, atmospheric climate indices, sea surface temperature, and phytoplankton biomass and productivity). Macrozooplankton were collected from the top 120 m of the water column in a mid-Peninsula study region divided into latitudinal (North, South, and Far South) and cross-shelf (coastal, shelf, slope) sub-regions. Trends for krill species included a 5-year cycle in abundance peaks (positive anomalies) for Euphausia superba, but no directional long-term trend, and an increase in Thysanoessa macrura in the North; variability in both species was strongly influenced by primary production 2-years prior. E. crystallorophias abundance was best explained by the Southern Annular Mode (SAM) and Multivariate El Niño Southern Oscillation Index (MEI), and was more abundant in higher ice conditions. The salp Salpa thompsoni and thecosome pteropod Limacina helicina cycled between negative and positive anomalies in the North, but showed increasing positive anomalies in the South over time. Variation in salp and pteropod abundance was best explained by SAM and the MEI, respectively, and both species were more abundant in lower ice conditions. There was a long-term increase in some carnivorous gelatinous zooplankton (polychaete worm Tomopteris spp.) and amphipods. Abundance of Pseudosagitta spp. chaetognaths was closely related to SAM, with higher abundance tied to lower ice conditions. Long-term changes and sub-decadal cycles of WAP macrozooplankton community composition may affect energy transfer to higher trophic levels, and alter biogeochemical cycling in this seasonally productive and sensitive polar ecosystem.

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.

Assessing the impact of diclofenac, ibuprofen and sildenafil citrate (Viagra®) on the fertilisation biology of broadcast spawning marine invertebrates.

PubMed

Mohd Zanuri, Norlaila Binti; Bentley, Matthew G; Caldwell, Gary S

2017-06-01

Exposure to synthetic chemicals is a key environmental challenge faced by aquatic organisms. The time and dose effects of the pharmaceuticals diclofenac, ibuprofen, and sildenafil citrate on sperm motility and successful fertilisation are studied using the echinoderms, Asterias rubens and Psammechinus miliaris, and the polychaete worm Arenicola marina, all important components of the marine benthos. Motility was reduced for all species when exposed to diclofenac concentrations ≥0.1 μg/L. Exposure to ≥1.0 μg/L of ibuprofen affected only P. miliaris gametes and fertilisation success of A. marina. A. rubens and P. miliaris sperm increased in both percentage motility and swimming velocity when exposed to sildenafil citrate at concentrations ≥18 and ≥ 50 ng/L, respectively. Pre-incubation of sperm with sildenafil citrate significantly increased fertilisation success in A. rubens and P. miliaris but not in A. marina. Pre-incubated A. rubens oocytes fertilised successfully in ibuprofen. According to EU Directive 93/67/EEC, diclofenac is classified as a very toxic substance to gametes of A. rubens, P. miliaris, and A. marina (EC 50  = 100-1000 μg/L) while ibuprofen is classified as very toxic to gametes of P. miliaris but non-toxic to gametes of A. marina (EC 50  > 10,000 μg/L). The present study indicates that diclofenac exposure may have negative impacts on invertebrate reproductive success, whereas ibuprofen potentially may compromise P. miliaris reproduction. This study provides a valuable insight into the mechanisms that allow marine invertebrates to survive and reproduce in contaminated and changing habitats. Copyright © 2017 Elsevier Ltd. All rights reserved.

Elucidating Mechanisms by which Invertebrate Larval Settlement is Affected by Biofilm Ciliates

NASA Astrophysics Data System (ADS)

Shimeta, J.; Watson, M. G.; Zalizniak, L.; Scardino, A. J.

2016-02-01

Despite extensive studies of benthic invertebrate larvae responding to settlement cues from bacteria and microalgae in biofilms, the roles of protozoa have been largely ignored. We recently showed that an assemblage of biofilm ciliates affected larval settlement and survival rates among two polychaetes, a mussel, and a bryozoan, being inhibitory to some and facilitative to others. Here we investigated settlement inhibition further for the serpulid worm, Galeolaria caespitosa, and the mussel, Mytilus galloprovincialis. Single species of ciliates were capable of inhibiting settlement by up to 68%. The effects were density dependent, with the strength of inhibition being directly related to ciliate abundance. The strength of inhibition also differed significantly among ciliate species, suggesting that both the abundance and makeup of ciliate assemblages could be an important variable determining settlement rates in the field. We studied the mechanisms of inhibition further with G. caespitosa and the ciliate, Euplotes minuta. Filtrate from ciliate cultures failed to inhibit settlement, indicating that dissolved chemicals were not the inhibiting factor. Physical presence of ciliates was inhibitory, as demonstrated by video analysis of larval search behavior. Following contact with a ciliate, larval swimming was disrupted, including retreat from the substratum and significant changes in swimming angles. Ciliates may also have influenced settlement indirectly by altering cues from biofilm bacteria. Although bacterial densities were unaffected by ciliate grazing during the assays, bacterial distributions were significantly more clumped in the presence of ciliates, which could perhaps affect the suitability of the biofilm for larvae. These organism-scale interactions at the biofilm boundary could produce significant constraints on larval recruitment patterns and suggest that further studies are needed on the roles of protozoans in boundary layer processes.

THE BIOLOGICAL AND GEOGRAPHICAL DISTRIBUTION IN THE IRISH SEA OF RADIOACTIVE EFFLUENT FROM WINDSCALE WORKS 1959 TO 1960

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mauchline, J.

1963-01-01

Investigations to determine the fate of the radioactive effluent which is discharged from Windscale Works into the northeastern Irish Sea were made. The ash contents of 17 species of seaweeds and 67 species of invertebrates common in the sea area were determined. Levels of radioactivity originating from k/sup 40/ and other naturally occurring radioisotopes were investigated and are discussed. A few measurements of nuclides in the sea areas distant from Sellafield were made to assess the contribution to the Irish Sea of nuclides from fallout sources. The levels of BETA activity in the samples of marine organisms decreased by amore » factor of 20 in the first 20 miles of distance north or south from Sellafield. No significant build-up of effluent material has taken place in tlie vicinity of Sellafield during the past 7 years, nor is there evidence of a build- up in any other area. No organisms were found to concentrate fission products by factors greater than those previously known. Typical concentration factors for ruthenium, cerium, and zirconium in seaweeds and invertebrates were of the order of 1000. Values for cesium were about 100 and for strontium less than 40. For fish, the concentration factors tended to be somewhat lower, especially for ruthenium and strontium. Marked differences were found between species and this enables a number of species to be selected for possible use as biological indicators. Of the seaweeds, Laminaria spp: Corallina officinalis, and Ceramium rubrum are suitable. Among the animals the most convenient are the polychaete worms, Balanus porcatus (barnacle), Littorina littorea (winkle), and Crangon vuigaris (shrimp). (auth)« less

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

2017-07-01

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 affect reproductive performance of the sandworm P. nuntia.

The biogenic reefs formed by the alien polychaete Hydroides dianthus (Serpulidae, Annelida) favor the polyp stage of Aurelia coerulea (Cnidaria, Scyphozoa) in a coastal artificial lake.

PubMed

Dong, Zhijun; Sun, Tingting; Wang, Lei

2018-04-01

Blooms of the moon jellyfish Aurelia coerulea frequently occur in coastal waters. The increased availability of substrates for the settlement and proliferation of polyps due to the expansion of artificial structures in coastal areas has been proposed as a possible contributing factor in jellyfish blooms. This paper investigates whether a marine artificial lake (Fenghuang Lake) provides additional substrates for A. coerulea polyps and contributes to jellyfish blooms. High densities of A. coerulea ephyrae were discovered in this lake, with a mean density of 41 individuals/m 3 and a maximum measured density of 128 individuals/m 3 . Meanwhile, A. coerulea ephyrae were also found in the two emptying channels outside the lake, with a mean density of 13 individuals/m 3 . Underwater surveys revealed that dense colonies of A. coerulea polyps occurred mainly on biogenic reefs formed by a polychaete, which was identified as an invasive serpulid species Hydroides dianthus, based on the phylogenetic analysis of mitochondrial COI gene sequences. Our study highlights the potential modification of habitats by the alien polychaete H. dianthus, which might provide complex benthic habits suitable for the settlement and proliferation of A. coerulea polyps and may contribute to jellyfish blooms in the marine artificial lake and nearby coastal waters. Copyright © 2018 Elsevier Ltd. All rights reserved.

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.

Influence of environmental properties on macrobenthos in the northwest Indian shelf.

PubMed

Jayaraj, K A; Jayalakshmi, K V; Saraladevi, K

2007-04-01

The paper deals with the standing stock of macrobenthic infauna and associated environmental factors influencing the benthic community in the shelf region of the northwest Indian coast. The data were collected onboard FORV Sagar Sampada during the winter monsoon (January-February, 2003) to understand the community structure and the factors influencing the benthic distribution. The environmental parameters, sediment characteristics and macrobenthic infauna were collected at 26 stations distributed in the depths between 30 and 200 m extending from Mormugao to Porbander. Total benthic abundance was high in lower depths (50-75 m), and low values noticed at 30 m depth contour was peculiar. Polychaetes were the dominant group and were more abundant in shallow and middle depths with moderate organic matter, clay and relatively high dissolved oxygen. On the other hand crustaceans and molluscs were more abundant in deeper areas having sandy sediment and low temperature. High richness and diversity of whole benthic groups observed in deeper depths counter balanced the opposite trend shown by polychaete species. Generally benthos preferred medium grain sized texture with low organic matter and high organic matter had an adverse effect especially on filter feeders. Deposit feeding polychaetes dominated in shallow depths while carnivore species in the middle depths. Ecologically, benthos were controlled by a combination of factors such as temperature, salinity, dissolved oxygen, sand and organic matter and no single factor could be considered as an ecological master factor.

Cuticular surface damage of Ascaridia galli adult worms treated with Veitchia merrillii betel nuts extract in vitro

PubMed Central

Balqis, Ummu; Hambal, Muhammad; Rinidar; Athaillah, Farida; Ismail; Azhar; Vanda, Henni; Darmawi

2017-01-01

Aim: The objective of this research was to in vitro evaluate the cuticular surface damage of Ascaridia galli adult worms treated with ethanolic extract of betel nuts Veitchia merrillii. Materials and Methods: Phytochemical screening was done using FeCl3, Wagner and Dragendorff reagents, NaOH, MgHCl, and Liebermann–Burchard reaction test. Amount of 16 worms were segregated into four groups with three replicates. Four worms of each group submerged into phosphate buffered saline, 25 mg/ml, and 75 mg/ml crude ethanolic extract of V. merrillii, and 15 mg/ml albendazole. The effect of these extract was observed 40 h after incubation as soon as worms death. The worms were sectioned transversally and were explored for any cuticular histopathological changes in their body surface under microscope. Results: We found that the ethanolic extract of V. merrillii betel nuts contains tannins, alkaloids, flavonoids, triterpenoids, and saponins. The ethanolic extract of betel nuts V. merrillii induces surface alterations caused cuticular damage of A. galli adult worms. Conclusion: We concluded that ethanolic extract of betel nuts V. merrillii possess anthelmintic activity caused cuticular damage of A. galli adult worms. PMID:28831213

Inequalities in body size among mermithid nematodes parasitizing earwigs.

PubMed

Maure, Fanny; Poulin, Robert

2016-12-01

Variation among body sizes of adult parasitic worms determines the relative genetic contribution of individuals to the next generation as it affects the effective parasite population size. Here, we investigate inequalities in body size and how they are affected by intensity of infection in Mermis nigrescens (Mermithidae: Nematoda) parasitizing the European earwig Forficula auricularia in New Zealand. Among a population of pre-adult worms prior to their emergence from the host, we observed only modest inequalities in body length; however, among worms sharing the same individual host, inequalities in body sizes decreased with increasing intensity of infection. Thus, the more worms occurred in a host, the more the second-longest, third-longest and even fourth-longest worms approached the longest worm in body length. This pattern, also known from another mermithid species, suggests that worms sharing the same host may have infected it roughly simultaneously, when the host encountered a clump of eggs in the environment. Thus, the life history and mode of infection of the parasite may explain the modest inequalities in the sizes achieved by pre-adult worms, which are lower than those reported for endoparasitic helminths of vertebrates.

New Geometry of Worm Face Gear Drives with Conical and Cylindrical Worms: Generation, Simulation of Meshing, and Stress Analysis

NASA Technical Reports Server (NTRS)

Litvin, Faydor L.; Nava, Alessandro; Fan, Qi; Fuentes, Alfonso

2002-01-01

New geometry of face worm gear drives with conical and cylindrical worms is proposed. The generation of the face worm-gear is based on application of a tilted head-cutter (grinding tool) instead of application of a hob applied at present. The generation of a conjugated worm is based on application of a tilted head-cutter (grinding tool) as well. The bearing contact of the gear drive is localized and is oriented longitudinally. A predesigned parabolic function of transmission errors for reduction of noise and vibration is provided. The stress analysis of the gear drive is performed using a three-dimensional finite element analysis. The contacting model is automatically generated. The developed theory is illustrated with numerical examples.

Worms--a "license to kill".

PubMed

Kaminsky, Ronald; Rufener, Lucien; Bouvier, Jacques; Lizundia, Regina; Schorderet Weber, Sandra; Sager, Heinz

2013-08-01

Worm infections can cause severe harm and death to both humans and numerous domestic and wild animals. Despite the fact that there are many beneficial worm species, veterinarians, physicians and parasitologists have multiple reasons to combat parasitic worms. The pros and cons of various approaches for the discovery of new control methods are discussed, including novel anthelmintics, vaccines and genetic approaches to identify novel drug and vaccine targets. Currently, the mainstay of worm control remains chemotherapy and prophylaxis. The importance of knowledgeable and wise use of the available anthelmintics is highlighted. Copyright © 2013 Elsevier B.V. All rights reserved.

Periorbital dirofilariasis—Clinical and imaging findings: Live worm on ultrasound

PubMed Central

Gopinath, Thandre N; Lakshmi, K P; Shaji, P C; Rajalakshmi, P C

2013-01-01

Ocular dirofilariasis is a zoonotic filariasis caused by nematode worm,Dirofilaria. We present a case of dirofilariasis affecting the upper eyelid in a 2-year-old child presenting as an acutely inflammed cyst, from southern Indian state of Kerala. Live adult worm was surgically removed and confirmed to be Dirofilaria repens. Live worm showing continuous movement was seen on the pre-operative high-resolution ultrasound. Ultrasound can be helpful in pre-operative identification of live worm. Imaging findings reported in literature are very few. We describe the clinical, ultrasound, and magnetic resonance imaging (MRI) findings. PMID:23803483

Worm Gear With Hydrostatic Engagement

NASA Technical Reports Server (NTRS)

Chaiko, Lev I.

1994-01-01

In proposed worm-gear transmission, oil pumped at high pressure through meshes between teeth of gear and worm coil. Pressure in oil separates meshing surfaces slightly, and oil reduces friction between surfaces. Conceived for use in drive train between gas-turbine engine and rotor of helicopter. Useful in other applications in which weight critical. Test apparatus simulates and measures some loading conditions of proposed worm gear with hydrostatic engagement.

Formation of Worm-Like Micelles in Mixed N-Hexadecyl-N-Methylpyrrolidinium Bromide-Based Cationic Surfactant and Anionic Surfactant Systems

PubMed Central

Dai, Caili; Yan, Zhihu; You, Qing; Du, Mingyong; Zhao, Mingwei

2014-01-01

Through the descriptive and rheological characterization of worm-like micelles formed by N-hexadecyl-N-methylpyrrolidinium bromide and sodium laurate, the formation and properties of the worm-like micelles were affected by the concentrations of sodium laurate and temperature. Additionally, cryogenic transmission electron microscopy images further validated the formation of worm-like micelles. PMID:25019152

Worm Burden-Dependent Disruption of the Porcine Colon Microbiota by Trichuris suis Infection

PubMed Central

Wu, Sitao; Li, Robert W.; Li, Weizhong; Beshah, Ethiopia; Dawson, Harry D.; Urban, Joseph F.

2012-01-01

Helminth infection in pigs serves as an excellent model for the study of the interaction between human malnutrition and parasitic infection and could have important implications in human health. We had observed that pigs infected with Trichuris suis for 21 days showed significant changes in the proximal colon microbiota. In this study, interactions between worm burden and severity of disruptions to the microbial composition and metabolic potentials in the porcine proximal colon microbiota were investigated using metagenomic tools. Pigs were infected by a single dose of T. suis eggs for 53 days. Among infected pigs, two cohorts were differentiated that either had adult worms or were worm-free. Infection resulted in a significant change in the abundance of approximately 13% of genera detected in the proximal colon microbiota regardless of worm status, suggesting a relatively persistent change over time in the microbiota due to the initial infection. A significant reduction in the abundance of Fibrobacter and Ruminococcus indicated a change in the fibrolytic capacity of the colon microbiota in T. suis infected pigs. In addition, ∼10% of identified KEGG pathways were affected by infection, including ABC transporters, peptidoglycan biosynthesis, and lipopolysaccharide biosynthesis as well as α-linolenic acid metabolism. Trichuris suis infection modulated host immunity to Campylobacter because there was a 3-fold increase in the relative abundance in the colon microbiota of infected pigs with worms compared to naïve controls, but a 3-fold reduction in worm-free infected pigs compared to controls. The level of pathology observed in infected pigs with worms compared to worm-free infected pigs may relate to the local host response because expression of several Th2-related genes were enhanced in infected pigs with worms versus those worm-free. Our findings provided insight into the dynamics of the proximal colon microbiota in pigs in response to T. suis infection. PMID:22532855

Fourier-Based Diffraction Analysis of Live Caenorhabditis elegans.

PubMed

Magnes, Jenny; Hastings, Harold M; Raley-Susman, Kathleen M; Alivisatos, Clara; Warner, Adam; Hulsey-Vincent, Miranda

2017-09-13

This manuscript describes how to classify nematodes using temporal far-field diffraction signatures. A single C. elegans is suspended in a water column inside an optical cuvette. A 632 nm continuous wave HeNe laser is directed through the cuvette using front surface mirrors. A significant distance of at least 20-30 cm traveled after the light passes through the cuvette ensures a useful far-field (Fraunhofer) diffraction pattern. The diffraction pattern changes in real time as the nematode swims within the laser beam. The photodiode is placed off-center in the diffraction pattern. The voltage signal from the photodiode is observed in real time and recorded using a digital oscilloscope. This process is repeated for 139 wild type and 108 "roller" C. elegans. Wild type worms exhibit a rapid oscillation pattern in solution. The "roller" worms have a mutation in a key component of the cuticle that interferes with smooth locomotion. Time intervals that are not free of saturation and inactivity are discarded. It is practical to divide each average by its maximum to compare relative intensities. The signal for each worm is Fourier transformed so that the frequency pattern for each worm emerges. The signal for each type of worm is averaged. The averaged Fourier spectra for the wild type and the "roller" C. elegans are distinctly different and reveal that the dynamic worm shapes of the two different worm strains can be distinguished using Fourier analysis. The Fourier spectra of each worm strain match an approximate model using two different binary worm shapes that correspond to locomotory moments. The envelope of the averaged frequency distribution for actual and modeled worms confirms the model matches the data. This method can serve as a baseline for Fourier analysis for many microscopic species, as every microorganism will have its unique Fourier spectrum.

Value-Range Analysis of C Programs

NASA Astrophysics Data System (ADS)

Simon, Axel

In 1988, Robert T. Morris exploited a so-called buffer-overflow bug in finger (a dæmon whose job it is to return information on local users) to mount a denial-of-service attack on hundreds of VAX and Sun-3 computers [159]. He created what is nowadays called a worm; that is, a crafted stream of bytes that, when sent to a computer over the network, utilises a buffer-overflow bug in the software of that computer to execute code encoded in the byte stream. In the case of a worm, this code will send the very same byte stream to other computers on the network, thereby creating an avalanche of network traffic that ultimately renders the network and all computers involved in replicating the worm inaccessible. Besides duplicating themselves, worms can alter data on the host that they are running on. The most famous example in recent years was the MSBlaster32 worm, which altered the configuration database on many Microsoft Windows machines, thereby forcing the computers to reboot incessantly. Although this worm was rather benign, it caused huge damage to businesses who were unable to use their IT infrastructure for hours or even days after the appearance of the worm. A more malicious worm is certainly conceivable [187] due to the fact that worms are executed as part of a dæmon (also known as "service" on Windows machines) and thereby run at a privileged level, allowing access to any data stored on the remote computer. While the deletion of data presents a looming threat to valuable information, even more serious uses are espionage and theft, in particular because worms do not have to affect the running system and hence may be impossible to detect.

Mobile Transactional Modelling: From Concepts to Incremental Knowledge

NASA Astrophysics Data System (ADS)

Launders, Ivan; Polovina, Simon; Hill, Richard

In 1988, Robert T. Morris exploited a so-called buffer-overflow bug in finger (a dæmon whose job it is to return information on local users) to mount a denial-of-service attack on hundreds of VAX and Sun-3 computers [159]. He created what is nowadays called a worm; that is, a crafted stream of bytes that, when sent to a computer over the network, utilises a buffer-overflow bug in the software of that computer to execute code encoded in the byte stream. In the case of a worm, this code will send the very same byte stream to other computers on the network, thereby creating an avalanche of network traffic that ultimately renders the network and all computers involved in replicating the worm inaccessible. Besides duplicating themselves, worms can alter data on the host that they are running on. The most famous example in recent years was the MSBlaster32 worm, which altered the configuration database on many Microsoft Windows machines, thereby forcing the computers to reboot incessantly. Although this worm was rather benign, it caused huge damage to businesses who were unable to use their IT infrastructure for hours or even days after the appearance of the worm. A more malicious worm is certainly conceivable [187] due to the fact that worms are executed as part of a dæmon (also known as "service" on Windows machines) and thereby run at a privileged level, allowing access to any data stored on the remote computer. While the deletion of data presents a looming threat to valuable information, even more serious uses are espionage and theft, in particular because worms do not have to affect the running system and hence may be impossible to detect.

De-worming school children and hygiene intervention.

PubMed

Luong, T V

2003-06-01

Helminths or worm infestations refer to worms that live as parasites in the human body and are a fundamental cause of disease associated with health and nutrition problems beyond gastrointestinal tract disturbances. Globally, over 3.5 billion people are infected with intestinal worms, of which 1.47 billion are with roundworm, 1.3 billion people with hookworm and 1.05 billion with whipworm. School children aged 5 - 15 years suffer the highest infection rate and worm burden that attributes to poor sanitation and hygiene. About 400 million school-age children are infected with roundworm, whipworm and hookworm worldwide, a large proportion of whom are found in the East Asia region (Cambodia, China, Lao PDR, Thailand and Vietnam). These parasites consume nutrients from children they infect, thus retarding their physical development. They destroy tissues and organs, cause abdominal pain, diarrhoea, intestinal obstruction, anaemia, ulcers and other health problems. All of these consequences of infection can slow cognitive development and thus impair learning. De-worming school children by anthelmintic drug treatment is a curative approach for expelling the heavy worm load. However, drug therapy alone is only a short-term measure of reducing worm infection and re-infection is frequent. Control measures through improved sanitation, hygiene and de-worming are needed to prevent infection and re-infection. UNICEF has supported many governments in this (and other) regions to assist in the provision of water supply and sanitary facilities and intensive hygiene education in many schools through the Water, Environment and Sanitation (WES) programme. The UNICEF supported school sanitation and hygiene education (SSHE) programme, and other programmes, could effectively enhance behaviour change in children to break the routes of worm transmission and other waterborne diseases.

Fluorescence hyperspectral imaging technique for foreign substance detection on fresh-cut lettuce.

PubMed

Mo, Changyeun; Kim, Giyoung; Kim, Moon S; Lim, Jongguk; Cho, Hyunjeong; Barnaby, Jinyoung Yang; Cho, Byoung-Kwan

2017-09-01

Non-destructive methods based on fluorescence hyperspectral imaging (HSI) techniques were developed to detect worms on fresh-cut lettuce. The optimal wavebands for detecting the worms were investigated using the one-way ANOVA and correlation analyses. The worm detection imaging algorithms, RSI-I (492-626)/492 , provided a prediction accuracy of 99.0%. The fluorescence HSI techniques indicated that the spectral images with a pixel size of 1 × 1 mm had the best classification accuracy for worms. The overall results demonstrate that fluorescence HSI techniques have the potential to detect worms on fresh-cut lettuce. In the future, we will focus on developing a multi-spectral imaging system to detect foreign substances such as worms, slugs and earthworms on fresh-cut lettuce. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

A genetic analysis of Trichuris trichiura and Trichuris suis from Ecuador.

PubMed

Meekums, Hayley; Hawash, Mohamed B F; Sparks, Alexandra M; Oviedo, Yisela; Sandoval, Carlos; Chico, Martha E; Stothard, J Russell; Cooper, Philip J; Nejsum, Peter; Betson, Martha

2015-03-19

Since the nematodes Trichuris trichiura and T. suis are morphologically indistinguishable, genetic analysis is required to assess epidemiological cross-over between people and pigs. This study aimed to clarify the transmission biology of trichuriasis in Ecuador. Adult Trichuris worms were collected during a parasitological survey of 132 people and 46 pigs in Esmeraldas Province, Ecuador. Morphometric analysis of 49 pig worms and 64 human worms revealed significant variation. In discriminant analysis morphometric characteristics correctly classified male worms according to host species. In PCR-RFLP analysis of the ribosomal Internal Transcribed Spacer (ITS-2) and 18S DNA (59 pig worms and 82 human worms), nearly all Trichuris exhibited expected restriction patterns. However, two pig-derived worms showed a "heterozygous-type" ITS-2 pattern, with one also having a "heterozygous-type" 18S pattern. Phylogenetic analysis of the mitochondrial large ribosomal subunit partitioned worms by host species. Notably, some Ecuadorian T. suis clustered with porcine Trichuris from USA and Denmark and some with Chinese T. suis. This is the first study in Latin America to genetically analyse Trichuris parasites. Although T. trichiura does not appear to be zoonotic in Ecuador, there is evidence of genetic exchange between T. trichiura and T. suis warranting more detailed genetic sampling.

[Chronobiological studies on effect of cyclosporin A (CsA) against adult male worms of Schistosoma mansoni in vitro].

PubMed

Liu, J; Chappell, L H

1998-01-01

To study the action mode of cyclosporin A (CsA) against Schistosoma mansoni in vitro. MF1 mice were infected with Schistosoma mansoni cercariae for 6 weeks when the adult worms were recovered by portal perfusion. The male worms of S. mansoni recovered were exposed to varying concentrations of CsA at 8, 16, and 24 h in vitro. Drug induced damage to the male worm surface was chrono-biologically observed throughout these experiments by SEM. After the male worms of S. mansoni were incubated with 1 microgram/ml CsA for 8-24 h, the tegument showed swelling of ridges with appearance of holes on their surface and detachment of a part of spines. The above damage of the tegument became more evident in male worms after incubation with 10, 15, 20 micrograms/ml CsA for 8-24 h. Moreover, incubation of male worms with 25 micrograms/ml CsA for 8-24 h resulted in significant deformation and disruption of tegument, rupture of ridges and detachment of spines. The tegumental damage of male worms of S. mansoni was dose- and time-dependent. The antischistosomal action of CsA is direct, the schistosome tegument appears to be the main site for CsA attack.

Improved Perceptions and Practices Related to Schistosomiasis and Intestinal Worm Infections Following PHAST Intervention on Kome Island, North-Western Tanzania.

PubMed

Mwanga, Joseph R; Kaatano, Godfrey M; Siza, Julius E; Chang, Su Young; Ko, Yunsuk; Kullaya, Cyril M; Nsabo, Jackson; Eom, Keeseon S; Yong, Tai-Soon; Chai, Jong-Yil; Min, Duk-Young; Rim, Han-Jong; Changalucha, John M

2015-10-01

Schistosomiasis and intestinal worm infections are widespread diseases of public health importance in Tanzania. A study on perceptions and practices related to schistosomiasis and intestinal worm infections was undertaken among a community population of Kome Island in Sengerema District, north-western Tanzania, where intestinal schistosomiasis and intestinal worm infections are endemic. Schistosomiasis and intestinal worm-related perceptions and practices were assessed before and 3 years after implementation of a participatory hygiene and sanitation transformation (PHAST) intervention as a control measure. Data were obtained from baseline and post-intervention knowledge, attitudes, and practices (KAP) questionnaire surveys conducted twice in 2009 and 2012 among 82 individuals aged ≥15 years. We found significant increases in respondents' knowledge of the cause, transmission, symptoms, health consequences, and prevention of schistosomiasis and intestinal worm infections after PHAST intervention. The increase in respondents' knowledge on almost all aspects of the said infections was translated into actions to control schistosomiasis and intestinal worm infections. This has not been achieved by chance, but due to well-designed and locally-adapted PHAST intervention. We conclude that despite criticisms, PHAST approach is still useful in empowering communities to control water, sanitation, and hygiene related infectious diseases such as schistosomiasis and intestinal worm infections.

Spatial and temporal differences in giant kidney worm, dictophyma renale, prevalence in Minnesota Mink, Mustela vison

USGS Publications Warehouse

Mech, L.D.

2008-01-01

Examination of 110 Mink (Mustela vison) carcasses from 1998 through 2007 indicated that the giant kidney worm, Dioctophyma renale, occurred in Pine and Kanabec Counties of eastern Minnesota with annual prevalences of 0-92%. Worm prevalence increased from 20% in 1999 to 92% in 2001 and decreased to 6% in 2005. During 2000 to 2007, no worms were found in Mink from Anoka and Chisago Counties (n = 54), and in 2000, none in 107 Mink from LeSeur, Freeborn, Redwood, Brown and Watonwan Counties. Changes in kidney worm prevalence were positively related to trapping success, considered an index of Mink density.

Propagation Modeling and Defending of a Mobile Sensor Worm in Wireless Sensor and Actuator Networks.

PubMed

Wang, Tian; Wu, Qun; Wen, Sheng; Cai, Yiqiao; Tian, Hui; Chen, Yonghong; Wang, Baowei

2017-01-13

WSANs (Wireless Sensor and Actuator Networks) are derived from traditional wireless sensor networks by introducing mobile actuator elements. Previous studies indicated that mobile actuators can improve network performance in terms of data collection, energy supplementation, etc. However, according to our experimental simulations, the actuator's mobility also causes the sensor worm to spread faster if an attacker launches worm attacks on an actuator and compromises it successfully. Traditional worm propagation models and defense strategies did not consider the diffusion with a mobile worm carrier. To address this new problem, we first propose a microscopic mathematical model to describe the propagation dynamics of the sensor worm. Then, a two-step local defending strategy (LDS) with a mobile patcher (a mobile element which can distribute patches) is designed to recover the network. In LDS, all recovering operations are only taken in a restricted region to minimize the cost. Extensive experimental results demonstrate that our model estimations are rather accurate and consistent with the actual spreading scenario of the mobile sensor worm. Moreover, on average, the LDS outperforms other algorithms by approximately 50% in terms of the cost.

Metals and terrestrial earthworms (Annelida: Oligochaeta)

USGS Publications Warehouse

Beyer, W.N.

1981-01-01

The toxicity of metals to earthworms and the residues of metals found in earthworms are reviewed. Meta 1 concentrations are rarely high enough to be toxic to worms, but copper may reduce populations in orchards heavily treated with fungicides and in soil contaminated with pig wastes. The metals in some industrial sewage sludges may interfere with using sludge in vermiculture. Storage ratios (the concentration of a metal in worms divided by the concentration in soil) tend to be highest in infertile soil and lowest in media rich in organic matter, such as sewage sludge. Cadmium, gold, and selenium are highly concentrated by worms. Lead concentrations in worms may be very high, but are generally lower than concentrations in soil. Body burdens of both copper and zinc seem to be regulated by worms. Because worms are part of the food webs of many wildlife species, and also because they are potentially valuable feed supplements for domestic animals, the possible toxic effects of cadmium and other metals should be studied. Worms can make metals more available to food webs and can redistribute them in soil.

Comparing efficacy of different taxonomic resolutions and surrogates in detecting changes in soft bottom assemblages due to coastal defence structures.

PubMed

Bertasi, Fabio; Colangelo, Marina Antonia; Colosio, Francesco; Gregorio, Gianni; Abbiati, Marco; Ceccherelli, Victor Ugo

2009-05-01

Sandy shores on the West coast of the North Adriatic Sea are extensively protected by different types of defence structures to prevent coastal erosion. Coastal defence schemes modify the hydrodynamic regime, the sediment structure and composition thus affecting the benthic assemblages. This study examines the effectiveness in detecting changes in soft bottom assemblages caused by coastal defence structures by using different levels of taxonomic resolution, polychaetes and/or bivalves as surrogates and different data transformations. A synoptic analyses of three datasets of subtidal benthic macrofauna used in studies aimed at assessing the impact of breakwaters along the North Adriatic coast has been done. Analyses of similarities and correlations between distance matrices were done using matrices with different levels of taxonomic resolution, and with polychaetes or bivalves data alone. Lentidium mediterraneum was the most abundant species in all datasets. Its abundance was not consistently related to the presence of defence structures. Moreover, distribution patterns of L. mediterraneum were masking the structure of the whole macrofaunal assemblages. Removal of L. mediterraneum from the datasets allowed the detection of changes in benthic assemblages due to coastal defences. Analyses on different levels of taxonomic resolution showed that the level of family maintained sufficient information to detect the impacts of coastal defence structures on benthic assemblages. Moreover, the outcomes depended on the transformation used. Patterns of distribution of bivalves, used as surrogates, showed low correlations with the patterns of the total macrofaunal species assemblages. Patterns of polychaetes, if identified to the species or genus level showed higher correlations with the whole dataset. However, the identification of polychaetes to species and genus level is as costly as the identification of all macrobenthic taxa at family level. This study provided additional evidences that taxonomic sufficiency is a useful tool in environmental monitoring, also in investigations on the impacts of coastal defence structures on subtidal macrofauna. The use of coarser taxonomic level, being time-efficient, would allow improving sampling designs of monitoring programs by increasing replication in space and time and by allowing long term monitoring studies.

Chronic Sublethal Effects of San Francisco Bay Sediments on Nereis (Neanthes) Arenaceodentata: Non treatment Factors

DTIC Science & Technology

1992-09-01

example, grain size had no effect , while the number of worms added to each expo- sure vessel was critical. Direct transfer from 30 ppt to salinities !515... Effect of Salinity on Juvenile Worms ..................... 13 Effect of Ammonia on Juvenile Worms .................... 14 Resistance of Juvenile Worms to...experimental design used to evaluate salinity effects . Preliminary experiments indicated that nominal ammonia concentrations (0, 2.5, 5.0, 10, 20, and

The research of hourglass worm dynamic balancing simulation based on SolidWorks motion

NASA Astrophysics Data System (ADS)

Wang, Zhuangzhuang; Yang, Jie; Liu, Pingyi; Zhao, Junpeng

2018-02-01

Hourglass worm is extensively used in industry due to its characteristic of heavy-load and a large reduction ratio. Varying sizes of unbalanced mass distribution appeared in the design of a single head worm. With machines developing towards higher speed and precision, the vibration and shock caused by the unbalanced mass distribution of rotating parts must be considered. Therefore, the balance grade of these parts must meet higher requirements. A method based on theoretical analysis and SolidWorks motion software simulation is presented in this paper; the virtual dynamic balance simulation test of the hourglass worm was carried out during the design of the product, so as to ensure that the hourglass worm meet the requirements of dynamic balance in the design process. This can effectively support the structural design of the hourglass worm and provide a way of thinking and designing the same type of products.

Sago worms as a nutritious traditional and alternative food for rural children in Southeast Sulawesi, Indonesia.

PubMed

Nirmala, Intan R; Trees; Suwarni; Pramono, Mochammad S

2017-06-01

The sago worm Rhynchophorus ferrugineus is a nutritious food source found in the remaining parts of a sago palm trunk after the removal of sago starch by farmers. The effort to increase sago worm consumption is investigated in an intervention study among children aged <5 years. Children aged 1-5 years were allocated to a sago worm inclusive diet (n=10) and to a control group eating a usual diet, but without sago worms (n=13). Snacks were served once per day (100 g) for 45 days and designed to contain similar amounts of vegetables (carrots and long beans) and other ingredients including rice, sticky rice, cassava, sweet potato, banana, or tofu with or without sago worms. Food preference was ascertained by interview. Anthropometric measurements were taken at baseline and the endpoint. After mixing all food stuffs into one product for instance nasi gurih, protein and fat content in the intervention group was higher compared to control group (8.8 g and 7.3 g vs 4.7 g and 0.5 g respectively). In the intervention group receiving complementary feeding with sago worms, children's height changed minimally as did the control group (0.3 vs 0.2 cm); no difference was observed between the groups regarding weight or height. Sago worm consumption can diversify the diet through usage in various dishes, so improving its overall nutritional quality. Worm addition in an intervention program does not compromise, but maintains nutritional value. Local use adds affordability and sustainability to the food and health systems in a sago-consuming culture, so contributing to food security.

Robust tracking and quantification of C. elegans body shape and locomotion through coiling, entanglement, and omega bends

PubMed Central

Roussel, Nicolas; Sprenger, Jeff; Tappan, Susan J; Glaser, Jack R

2014-01-01

The behavior of the well-characterized nematode, Caenorhabditis elegans (C. elegans), is often used to study the neurologic control of sensory and motor systems in models of health and neurodegenerative disease. To advance the quantification of behaviors to match the progress made in the breakthroughs of genetics, RNA, proteins, and neuronal circuitry, analysis must be able to extract subtle changes in worm locomotion across a population. The analysis of worm crawling motion is complex due to self-overlap, coiling, and entanglement. Using current techniques, the scope of the analysis is typically restricted to worms to their non-occluded, uncoiled state which is incomplete and fundamentally biased. Using a model describing the worm shape and crawling motion, we designed a deformable shape estimation algorithm that is robust to coiling and entanglement. This model-based shape estimation algorithm has been incorporated into a framework where multiple worms can be automatically detected and tracked simultaneously throughout the entire video sequence, thereby increasing throughput as well as data validity. The newly developed algorithms were validated against 10 manually labeled datasets obtained from video sequences comprised of various image resolutions and video frame rates. The data presented demonstrate that tracking methods incorporated in WormLab enable stable and accurate detection of these worms through coiling and entanglement. Such challenging tracking scenarios are common occurrences during normal worm locomotion. The ability for the described approach to provide stable and accurate detection of C. elegans is critical to achieve unbiased locomotory analysis of worm motion. PMID:26435884

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dorfman, D.

Earthworms can live in soils containing high quantities of mercury, lead, and zinc. The worms (Lumbricus terrestris) concentrate these heavy metals in their tissues. The use of these worms to reduce the quantities of mercury and other heavy metals in soils may be practical. In July, 1993, a preliminary study was made using earthworms and soils with differing amounts of mercury, The quantities were 0.0 grams, 0.5 grams, and 1.0 grams of mercury as mercuric chloride. Earthworms were placed into these soils for two or more weeks, then harvested. The worms were rinsed with deionized water, then dissolved in nitricmore » acid. Each sample was prepared for analysis with the addition of HNO{sub 3}, H{sub 2}SO{sub 4}, potassium permanganate, and hydrozylamine hydrochloride. A Jerome Instrument gold foil analyzer was used to determine levels of mercury after volatilizing the sample with stannous chloride. Worms exposed to contaminated soils remove 50 to 1,400 times as much mercury as do worms in control soils. In a hypothetical case, a site contaminated with one pound of mercury, 1,000 to 45,000 worms would be required to reduce mercury levels to background levels in the soil (about 250 ppb). After harvesting worms in contaminated soil they could be dried (90% of their weight is water), and the mercury regained by chemical processes. Soil conducive to earthworm survival is required. This includes a well aerated loamy soil, proper pH (7.0), and periodic watering and feeding. There are several methods of harvesting worms, including flooding and electricity. Large numbers of worms can be obtained from commercial growers.« less

The role of hypoxia in structuring macrobenthos community off the Louisiana shelf

NASA Astrophysics Data System (ADS)

Shivarudrappa, S. K.; Briggs, K.

2013-12-01

Core samples were collected from 24 box cores belonging to four different provinces with varying hypoxia frequency and history in the northern Gulf of Mexico. Macrobenthos from these four provinces were sampled in spring, summer and late-summer seasons. According to historical data of bottom water oxygen concentration since 1985, the control province was exposed to hypoxia <25% of the time, the province 1 was exposed to hypoxia between 50% and 75% of the time, the province 2 was exposed to hypoxia between 25% and 50% of the time, and the province 3 was exposed to hypoxia more than 75% of the time. Samples from the three cruises performed between April 2009 and August 2010 were vertically sectioned to 25 cm sediment depth and analyzed for abundance, biomass, species diversity, and feeding types. Seasonal variability within provinces and between provinces was analyzed in terms of abundance and biomass. The Bray-Curtis dissimilarity indices indicated the four provinces have similar community composition, yet showed the impact of hypoxia in assemblages making up the four communities. Diversity indices were highest for the control province and lowest for province 3 during all three seasons, whereas diversity indices for provinces 1 and 2 showed variable seasonal variations due to hypoxia. Separation of the control province from province 3 at all three samplings by principal component analysis indicated the communities of these two provinces did not change over the period of the study. This difference in assemblages was confirmed by rarefaction curves of expected species diversity. Impact of grain size and organic matter concentration on the community structure was assessed using non-metric multi-dimensional scaling. Different species dominated by their abundance or their biomass at all four provinces, but the effect was magnified in the provinces other than the control. Capitellid, cossurid and spionid polychaetes dominated by abundance, whereas maldanid and nephtyid polychaetes and Nemerteans dominated by biomass. This implies that the fauna responsible for dominance by their abundance were small, opportunistic deposit feeders, and that large carnivores contributed to dominance by their biomass. Although species and abundance changed from province to province and season to season, the functional groups were nevertheless dominated, in order, by subsurface deposit feeders, surface deposit feeders, and carnivores at all provinces in all three seasons. This study provides insight into compositional changes in the macrobenthic community due to hypoxia and subsequent recovery from hypoxia on the northern Gulf of Mexico shelf between the Mississippi and Atchafalaya Rivers.

The provision of potable water in eradication of Guinea worm infection in Ezza North, Southeastern, Nigeria.

PubMed

Ede, Alison Okorie; Nwaokoro, Joakin Chidozie; Iwuala, C C; Amadi, A N; Akpelu, Ugochinyere Alvana

2014-10-01

Guinea worm is a parasite found in unprotected drinking water sources, causes considerable morbidity and loss of agricultural production among rural people. The study was to determine the current status of Guinea worm infection in Ezza North and to evaluate the impact of control measures on guinea worm infection. A total of 200 individuals in Ezza North Southeastern, Nigeria were examined for guinea worm infection. A standardized questionnaire was used to determine the effect of potable water on guinea worm eradication/control, the source of drinking water, information on the knowledge, attitude, symptom management practices, availability of health facilities and boreholes installation status. The instrument for data collection was well constructed, validated and reliable tested questionnaire by an expert. Data obtained was analyzed using Epi-Info model 3.4 versions. Results of a study indicated majority of the respondents 195 (97.5 %) have access to safe drinking water supply which indicated no case of Guinea worm infection. The active use of potable water supply was found among the age group of 20-30 years 71 (35.5 %) and higher in male (57.5 %) than females (42.5 %). The drastic reduction of Guinea worm infection to zero (0) level in Ezza North were due to multiple factors as health education, availability of functional boreholes, presence of health centers for immediate treatment if any case discovered.

Promoting positive health behaviours--'tooth worm' phenomenon and its implications.

PubMed

Gao, X L; Hsu, C Y S; Xu, Y C; Loh, T; Koh, D; Hwarng, H B

2012-03-01

'Tooth worm' is a traditional belief about the pathogen of dental caries (tooth decay). Nevertheless, in our previous study, parental 'tooth worm' belief was linked to a reduced caries risk of their children. This study aimed to further characterize the impact of parental 'tooth worm' belief on their children's caries experience and its psychobehavioural mechanisms. analytic observational study. Thirteen randomly selected kindergartens in Singapore. 1,782 preschoolers aged 3-6 years. Each child received an oral examination and microbiological tests. Parents completed a self-administered questionnaire on their socio-demographic background, oral health knowledge/attitude and child's oral health habits. Multivariate analysis confirmed a reduced chance of 'high caries rate' (number of affected teeth > 2) among children whose parents held the 'tooth worm' belief (Odds Ratio = 0.41; 95% Confidence Interval = 0.19-0.89). With such perception among parents, children brushed their teeth more frequently (p = 0.042). Since no difference in oral hygiene was observed, the health benefit of the "tooth worm" perception may be acquired through the delivery of fluoride (an agent with proven anti-caries effect) during frequent toothbrushing episodes. This study revealed a 'tooth worm' phenomenon, indicating that parental 'tooth worm' belief is associated with early establishment of regular toothbrushing habit and reduction of dental caries in children. This phenomenon and its psychobehavioural mechanisms, enriching our understanding of oral health behaviours, have implications for effective health education.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jewett, S.C.; Dean, T.A.

Injuries to the shallow subtidal eelgrass community were observed in the heavily oiled portions of Western Prince William Sound following the Exxon Valdez oil spill. High PAH concentrations were associated with observed differences in communities at oiled vs. reference sites. Dominant taxa within the eelgrass community, including infaunal amphipods, infaunal bivalves, helmet crabs, and leather stars were less abundant at oiled than at reference sites in 1990. Other taxa, including several families of opportunistic or stress-tolerant infaunal polychaetes and gastropods, epifaunal polychaetes and mussels, and small cod, were more abundant at oiled sites. By 1995, there was apparent recovery ofmore » most community constituents. However, not all taxa had recovered fully. Some evidence of slight hydrocarbon contamination still existed at some sites, and three infaunal bivalves, two amphipods, a crab, and a sea star were still more abundant at reference sites than at oiled sites.« less

Polychaete Tubes, Turbulence, and Erosion of Fine-Grained Sediment

NASA Astrophysics Data System (ADS)

Kincke-Tootle, A.; Frank, D. P.; Briggs, K. B.; Calantoni, J.

2016-02-01

The role of polychaete tubes protruding through the benthic boundary layer in promoting or hindering erosion of fine-grained sediment was examined in laboratory experiments. Diver core samples of the top 10cm of sediment were collected west of Trinity Shoal off the Louisiana coast in 10-m depth. Diver cores were used in laboratory experiments conducted in a unidirectional flume. Tubes that were constructed by polychaetes, which comprised 70% of the species from the study area, were inserted into the core sediment surface. The sediment cores were then placed in the 2-m long test section of a small oscillatory flow tunnel and high-speed, stereo particle image velocimetry was used to determine the 2-dimensional, 3-component fluid velocity at high temporal (100 Hz) and spatial (< 1mm vector spacing) resolution. The tubes that protruded above the boundary layer allowed vortices to be initiated. Tubes are made up of shell fragments and fine-grained sediment, allowing for some rigidity and resistance to the flow. Rigidity determines the resistance causing small-scale eddies to form. The small-scale turbulence incited scour erosion, allowing fine-grained particles to be suspended into the water and in some cases coarser particles to be mobilized. Less-rigid tubes succumb to the shear stress, inhibit the formation of small-scale eddies, limit sediment erodibility, and increase the critical shear stress of the sediment. Discussion will focus on a modification to the critical Shields parameter to account for the effects of benthic biological activity.

Lepidasthenia loboi sp. n. from Puerto Madryn, Argentina (Polychaeta, Polynoidae).

PubMed

Salazar-Vallejo, Sergio I; González, Norma Emilia; Salazar-Silva, Patricia

2015-01-01

Among polychaetes, polynoids have the highest number of symbiotic species found living with a wide variety of marine invertebrates, including other polychaetes. Lepidasthenia Malmgren, 1867 and Lepidametria Webster, 1879 were regarded as synonyms but belong to different subfamilies, although both have species associated with thelepodid or terebellid polychaetes. In this contribution Lepidasthenia loboi sp. n. is described from several specimens associated with the thelepodid Thelepus antarcticus Kinberg, 1867, collected on a rocky shore near Puerto Madryn, Argentina. Lepidasthenia loboi sp. n. can be confused with Lepidasthenia esbelta Amaral & Nonato, 1982 because both live with Thelepus, are of similar sizes with similar pigmentation patterns, and have giant neurochaetae. However, in Lepidasthenia loboi sp. n. all eyes are of the same size, cephalic and parapodial cirri are tapered and mucronate, the second pair of elytra is larger than the third, the ventral cirri arise at the base of parapodia such that they do not reach chaetal lobe tips, and neuraciculae are tapered. On the contrary, in Lepidasthenia esbelta the posterior eyes are larger than anterior ones, cephalic and parapodial appendages are swollen subdistally, the second and third pairs of elytra are of the same size, the ventral cirri arise medially such that their tips reach the neurochaetal lobe tips, and the neuraciculae have falcate tips. Some comments about other genera in the Lepidastheniinae, a simplified key to its genera, and a key to Lepidasthenia species with giant neurochaetae are also included.

Lepidasthenia loboi sp. n. from Puerto Madryn, Argentina (Polychaeta, Polynoidae)

PubMed Central

Salazar-Vallejo, Sergio I.; González, Norma Emilia; Salazar-Silva, Patricia

2015-01-01

Abstract Among polychaetes, polynoids have the highest number of symbiotic species found living with a wide variety of marine invertebrates, including other polychaetes. Lepidasthenia Malmgren, 1867 and Lepidametria Webster, 1879 were regarded as synonyms but belong to different subfamilies, although both have species associated with thelepodid or terebellid polychaetes. In this contribution Lepidasthenia loboi sp. n. is described from several specimens associated with the thelepodid Thelepus antarcticus Kinberg, 1867, collected on a rocky shore near Puerto Madryn, Argentina. Lepidasthenia loboi sp. n. can be confused with Lepidasthenia esbelta Amaral & Nonato, 1982 because both live with Thelepus, are of similar sizes with similar pigmentation patterns, and have giant neurochaetae. However, in Lepidasthenia loboi sp. n. all eyes are of the same size, cephalic and parapodial cirri are tapered and mucronate, the second pair of elytra is larger than the third, the ventral cirri arise at the base of parapodia such that they do not reach chaetal lobe tips, and neuraciculae are tapered. On the contrary, in Lepidasthenia esbelta the posterior eyes are larger than anterior ones, cephalic and parapodial appendages are swollen subdistally, the second and third pairs of elytra are of the same size, the ventral cirri arise medially such that their tips reach the neurochaetal lobe tips, and the neuraciculae have falcate tips. Some comments about other genera in the Lepidastheniinae, a simplified key to its genera, and a key to Lepidasthenia species with giant neurochaetae are also included. PMID:26798303

Environmental impact of bleufin tuna aquaculture on benthic assemblages in the western coast of Baja California, Mexico

NASA Astrophysics Data System (ADS)

Diaz-Castaneda, V.

2013-05-01

Sea-cage farming results in a constant rain of organic waste onto the surrounding benthos. In Baja California there is growing concern over the effects of sea-cages on the local environment: sediment chemistry and benthic communities. Samples were taken in 18 stations using a Van veen grab (0.1 m2) in Bahía Salsipuedes, Baja California in 2003, 2004, 2006 and 2008. Organisms belonging to 7 Phyla were collected: Polychaeta, Mollusca, Crustacea, Echinodermata, Cnidaria, Sipuncula and Bryozoa. Polychaetes were the dominant group followed by crustaceans and mollusks. Polychaetes were represented by 37 families and 157 species. Best represented families were Paraonidae, Cirratulidae, Spionidae, Glyceridae and Maldanidae. This study shows that in the NW area of the bay organic carbon (2.54%) and organic nitrogen (0.95%) are being accumulated (higher concentrations and lower Eh values) and smaller opportunistic species are increasing rapidly near the tuna pens. It is crucial to maintain "healthy" macrofaunal populations in order to enhance decomposition of organic matter and to prevent its excessive accumulation. The most abundant polychaete species were Aphelochaeta multifinis, Mediomastus ambiseta, Prionospio steenstrupi Spiophanes bombyx, Apoprionospio pygnaea, Paraonella sp, Monticellina sp, Aricidea (Allia) ramosa, Spiophanes bombyx and Levinsenia gracilis. The dominant trophic groups were deposit-feeders and carnivores. The buildup of organic matter on the seafloor has attracted scavenger species particularly peracarid crustaceans. Non-metric multidimensional scaling (MDS) separated stations depending of the distance to the tuna pens.

Digestive solubilization of sediment-associated pollutants: In vitro extraction vs. in vivo bioavailability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weston, D.P.; Mayer, L.M.

1995-12-31

A method using polychaete digestive fluids as a more biologically realistic extractant has recent been proposed as a means to quantify this bioavailable fraction. This work was intended to evaluate this approach with polynuclear aromatic hydrocarbons (PAH), and, in particular, to relate in vitro measures of PAH solubilization by digestive fluids to bioavailability as perceived by the whole animal. In tests with a variety of PAH-contaminated sediments, there were dramatic differences among the sediments in the amounts of PAH extracted by digestive fluids. About 50% of a PAH spike was extracted from a low organic carbon sediment during digestive fluidmore » extraction, while only 20% was extracted from a high organic carbon sediment. The relationships between these differences in PAH solubilization and true bioavailability were evaluated in polychaete bioaccumulation tests measuring PAH uptake rate coefficients and steady state body burdens. The work has also shown that desorption of PAH from ingested sediments in the whole animal approximated the quantities extracted in the in vitro tests. Moreover, desorption of PAH from ingested sediments was found to be greatest in that portion of the polychaete gut with the highest enzymatic activity and from which the digestive fluids had been collected. The digestive fluid extraction approach provides a new tool to examine digestive uptake of contaminants by manipulations that would be impossible in vivo, and may help to quantify a bioavailable contaminant fraction.« less

The impact of various distance between axes of worm gear on torque value. Worm gear test stand

NASA Astrophysics Data System (ADS)

Sobek, M.; Baier, A.; Grabowski, Ł.

2017-08-01

Transferring both rotational and translational movements in systems used in the automotive industry is a very important and complex issue. In addition, the situation becomes much more difficult and complicated when the design of the transition system requires a high precision of operation as well as a well definite and long operating life. Such requirements are imposed on all components of today’s motor vehicles. However, particular attention is paid to the elements that directly or indirectly affect the safety of persons traveling in the vehicle. Such components are undoubtedly components included as parts of the steering system of the vehicle. Power steering systems have been present in motor vehicles for more than a century. They go through continuous metamorphosis and they are getting better and better. Current power steering systems are based on an electric motor and some kind of transmission. Depending on the position of the drive relative to the steering column, different configurations of the transmission are used. This article will cover issues related to tests of power steering gearing using a worm drive. The worm drive is a very specific example of a propulsion system that uses twisted axles. Normally, in this type of transition you can find two gear units with the axis mounted with a 90° angle between. The components of the worm drive are a worm and a worm gear, also called a worm wheel. In terms of the geometrical form, the worm resembles a helical spur gear. The shape of the worm is similar to the shape of a screw with a trapezoidal thread. A correct matching of these two components ensures proper operation of the entire transmission. Incorrect positioning of the components in relation to each other can significantly reduce the lifetime of the drive unit, and also lead to abnormal work, eg by raising the noise level. This article describes a test method of finding the appropriate distance between the axles of both worm drive units by testing the torque change during gear operation.

Maternal hookworm modifies risk factors for childhood eczema: results from a birth cohort in Uganda

PubMed Central

Mpairwe, Harriet; Ndibazza, Juliet; Webb, Emily L; Nampijja, Margaret; Muhangi, Lawrence; Apule, Barbara; Lule, Swaib; Akurut, Hellen; Kizito, Dennison; Kakande, Mohammed; Jones, Frances M; Fitzsimmons, Colin M; Muwanga, Moses; Rodrigues, Laura C; Dunne, David W; Elliott, Alison M

2014-01-01

Background Worms may protect against allergy. Early-life worm exposure may be critical, but this has not been fully investigated. Objectives To investigate whether worms in pregnancy and in early childhood are associated with childhood eczema incidence. Methods The Entebbe Mother and Baby Study, an anthelminthic treatment trial, enrolled pregnant women between 2003 and 2005 in Uganda. Mothers were investigated for worms during pregnancy and children annually. Eczema was doctor-diagnosed from birth to age five years. A planned observational analysis was conducted within the trial cohort to investigate associations between worms and eczema. Results Data for 2345 live-born children were analysed. Hookworm was the most prevalent maternal worm (45%). Childhood worms were less prevalent. Eczema incidence was 4.68/100 person-years. Maternal hookworm was associated with reduced eczema incidence [adjusted hazard ratio (95% confidence interval), p-value: 0.71(0.51–0.99), 0.04] and modified effects of known risk factors for eczema: Dermatophagoides-specific IgE in children was positively associated with eczema incidence if the mother had no hookworm [2.72(1.11–6.63), 0.03], but not if the mother had hookworm [0.41(0.10–1.69), 0.22], interaction p-value = 0.03. Similar interactions were seen for maternal history of eczema {[2.87(1.31–6.27, 0.008) vs. [0.73(0.23–2.30), 0.60], interaction p-value = 0.05}, female gender {[1.82(1.22–2.73), 0.004 vs. [0.96(0.60–1.53), 0.87], interaction p-value = 0.04} and allergen-specific IgE. ChildhoodTrichuris trichiura and hookworm were inversely associated with eczema. Conclusions Maternal hookworm modifies effects of known risk factors for eczema. Mechanisms by which early-life worm exposures influence allergy need investigation. Worms or worm products, and intervention during pregnancy have potential for primary prevention of allergy. PMID:25171741

Tegumental alterations of adult Schistosoma japonicum harbored in mice treated with a single oral dose of mefloquine.

PubMed

Xiao, Shu-hua; Xue, Jian; Shen, Bing-gui

2010-02-01

To observe the effect of mefloquine on the tegument of adult Schistosoma japonicum harbored in mice. Twelve mice were each infected with 60-80 S. japonicum cercariae. At 35 days post-infection, 10 mice were treated orally with mefloquine at a single dose of 400 mg/kg. Two mice were sacrificed at 8 h, 24 h, 3 days, 7 days, and 14 days post-treatment respectively, and schistosomes were collected by the perfusion technique, fixed and examined under a scanning electron microscope. Schistosomes obtained from the remaining 2 untreated mice served as control. 8 h post-treatment, male and female schistosomes showed focal swelling of the worm body accompanied by extensive swelling, tough junction and fusion of tegumental ridges. Meanwhile, some of the sensory structures showed enlargement and part of them collapsed. 24 h after mefloquine administration, head portion of some male and female worms revealed high swelling accompanied by severe damage to oral sucker. 3 days post-treatment, focal swelling of worm body along the whole worm was universal. In some male and female worms, the damaged tegument fused together to form a large mass protruding from the tegumental surface. In addition, focal or extensive peeling of tegumental ridges was seen or collapse of enlarged sensory structure resulted in formation of hole-like appearance. 7 days post administration, focal swelling of worm body and damage to tegument induced by mefloquine were similar to those aforementioned, but focal peeling, collapse of enlarged sensory structures, and deformation of oral sucker in male and female worms were universal. 14 days post-treatment, individual male worm survived the treatment revealed normal appearance of tegumental ridges in head portion, although light focal swelling of worm body was still observed. Mefloquine causes focal swelling of worm body, extensive and severe damage to the tegument in adult S. japonicum.

Extrusion of Contracaecum osculatum nematode larvae from the liver of cod (Gadus morhua).

PubMed

Zuo, S; Barlaup, L; Mohammadkarami, A; Al-Jubury, A; Chen, D; Kania, P W; Buchmann, K

2017-10-01

Baltic cod livers have during recent years been found increasingly and heavily infected with third-stage larvae of Contracaecum osculatum. The infections are associated with an increasing population of grey seals which are final hosts for the parasite. Heavy worm burdens challenge utilization and safety of the fish liver products, and technological solutions for removal of worms are highly needed. We investigated the attachment of the worm larvae in liver tissue by use of histochemical techniques and found that the cod host encapsulates the worm larvae in layers of host cells (macrophages, fibroblasts) supported by enclosures of collagen and calcium. A series of incubation techniques, applying compounds targeting molecules in the capsule, were then tested for their effect to induce worm escape/release reactions. Full digestion solutions comprising pepsin, NaCl, HCl and water induced a fast escape of more than 60% of the worm larvae within 20 min and gave full release within 65 min but the liver tissue became highly dispersed. HCl alone, in concentrations of 48 and 72 mM, triggered a corresponding release of worm larvae with minor effect on liver integrity. A lower HCl concentration of 24 mM resulted in 80% release within 35 min. Water and physiological saline had no effect on worm release, and 1% pepsin in water elicited merely a weak escape reaction. In addition to the direct effect of acid on worm behaviour it is hypothesised that the acid effect on calcium carbonate in the encapsulation, with subsequent release of reaction products, may contribute to activation of C. osculatum larvae and induce escape reactions. Short-term pretreatment of infected cod liver and possibly other infected fish products, using low acid concentrations is suggested as part of a technological solution for worm clearance as low acid concentrations had limited macroscopic effect on liver integrity within 35 min.

Increased human IgE induced by killing Schistosoma mansoni in vivo is associated with pretreatment Th2 cytokine responsiveness to worm antigens.

PubMed

Walter, Klaudia; Fulford, Anthony J C; McBeath, Rowena; Joseph, Sarah; Jones, Frances M; Kariuki, H Curtis; Mwatha, Joseph K; Kimani, Gachuhi; Kabatereine, Narcis B; Vennervald, Birgitte J; Ouma, John H; Dunne, David W

2006-10-15

In schistosomiasis endemic areas, children are very susceptible to postchemotherapy reinfection, whereas adults are relatively resistant. Different studies have reported that schistosome-specific IL-4 and IL-5 responses, or posttreatment worm-IgE levels, correlate with subsequent low reinfection. Chemotherapy kills i.v. worms providing an in vivo Ag challenge. We measured anti-worm (soluble worm Ag (SWA) and recombinant tegumental Ag (rSm22.6)) and anti-egg (soluble egg Ag) Ab levels in 177 Ugandans (aged 7-50) in a high Schistosoma mansoni transmission area, both before and 7 wk posttreatment, and analyzed these data in relation to whole blood in vitro cytokine responses at the same time points. Soluble egg Ag-Ig levels were unaffected by treatment but worm-IgG1 and -IgG4 increased, whereas worm-IgE increased in many but not all individuals. An increase in worm-IgE was mainly seen in >15-year-olds and, unlike in children, was inversely correlated to pretreatment infection intensities, suggesting this response was associated both with resistance to pretreatment infection, as well as posttreatment reinfection. The increases in SWA-IgE and rSm22.6-IgE positively correlated with pretreatment Th2 cytokines, but not IFN-gamma, induced by SWA. These relationships remained significant after allowing for the confounding effects of pretreatment infection intensity, age, and pretreatment IgE levels, indicating a link between SWA-specific Th2 cytokine responsiveness and subsequent increases in worm-IgE. An exceptionally strong relationship between IL-5 and posttreatment worm-IgE levels in < 15-year-olds suggested that the failure of younger children to respond to in vivo Ag stimulation with increased levels of IgE, is related to their lack of pretreatment SWA Th2 cytokine responsiveness.

Worm melt fracture and fast die build-up at high shear rates in extrusion blow molding of large drums

NASA Astrophysics Data System (ADS)

Inn, Yong Woo; Sukhadia, Ashish M.

2017-05-01

In the extrusion blow molding process of high density polyethylene (HDPE) for making of large size drums, string-like defects, which are referred to as worm melt fracture in the industry, are often observed on the extrudate surface. Such string-like defects in various shapes and sizes are observed in capillary extrusion at very high shear rates after the slip-stick transition. The HDPE resin with broader molecular weight distribution (MWD) exhibits a greater degree of worm melt fracture while the narrow MWD PE resin, which has higher slip velocity and a uniform slip layer, shows a lesser degree of worm melt fracture. It is hypothesized that the worm melt fracture is related to fast die build-up and cohesive slip layer, a failure within the polymer melts at an internal surface. If the cohesive slip layer at an internal surface emerges out from the die, it can be attached on the surface of extrudate as string-like defects, the worm melt fracture. The resin having more small chains and lower plateau modulus can be easier to have such an internal failure and consequently exhibit more "worm" defects.

Propagation Modeling and Defending of a Mobile Sensor Worm in Wireless Sensor and Actuator Networks

PubMed Central

Wang, Tian; Wu, Qun; Wen, Sheng; Cai, Yiqiao; Tian, Hui; Chen, Yonghong; Wang, Baowei

2017-01-01

WSANs (Wireless Sensor and Actuator Networks) are derived from traditional wireless sensor networks by introducing mobile actuator elements. Previous studies indicated that mobile actuators can improve network performance in terms of data collection, energy supplementation, etc. However, according to our experimental simulations, the actuator’s mobility also causes the sensor worm to spread faster if an attacker launches worm attacks on an actuator and compromises it successfully. Traditional worm propagation models and defense strategies did not consider the diffusion with a mobile worm carrier. To address this new problem, we first propose a microscopic mathematical model to describe the propagation dynamics of the sensor worm. Then, a two-step local defending strategy (LDS) with a mobile patcher (a mobile element which can distribute patches) is designed to recover the network. In LDS, all recovering operations are only taken in a restricted region to minimize the cost. Extensive experimental results demonstrate that our model estimations are rather accurate and consistent with the actual spreading scenario of the mobile sensor worm. Moreover, on average, the LDS outperforms other algorithms by approximately 50% in terms of the cost. PMID:28098748

Toxic effects and bioaccumulation of the herbicide isoproturon in Tubifex tubifex (Oligocheate, Tubificidae): a study of significance of autotomy and its utility as a biomarker.

PubMed

Paris-Palacios, Séverine; Mosleh, Yahia Y; Almohamad, Mohamad; Delahaut, Laurence; Conrad, Arnaud; Arnoult, Fabrice; Biagianti-Risbourg, Sylvie

2010-06-01

Tubifex is the only animal reported to respond with autotomy to contamination. This response of contaminated worm is understood as a mode of metal excretion. Few data concern the potential of organic compounds to induce tubifex autotomy. The objective of this study was to investigate if autotomy can be induced by a herbicide isoproturon (IP) and be related to the way of excretion. Isoproturon accumulation in worm tissues and its effect on tubifex mortality, autotomy and regeneration rates were analysed after 4 and 7 days of exposure to the herbicide and also when worms were replaced for 10 days in clean water. IP accumulated in the same way in all parts of the worm body but IP metabolite rates were significantly higher in the posterior part of the worm. Thus the loss of the posterior part allows the worm to eliminate an important amount of pesticide. Autotomy has a population importance and is related to the degree of worm contamination so it may become an interesting biomarker. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Discrimination methods for biological contaminants in fresh-cut lettuce based on VNIR and NIR hyperspectral imaging

NASA Astrophysics Data System (ADS)

Mo, Changyeun; Kim, Giyoung; Kim, Moon S.; Lim, Jongguk; Lee, Seung Hyun; Lee, Hong-Seok; Cho, Byoung-Kwan

2017-09-01

The rapid detection of biological contaminants such as worms in fresh-cut vegetables is necessary to improve the efficiency of visual inspections carried out by workers. Multispectral imaging algorithms were developed using visible-near-infrared (VNIR) and near-infrared (NIR) hyperspectral imaging (HSI) techniques to detect worms in fresh-cut lettuce. The optimal wavebands that can detect worms in fresh-cut lettuce were investigated for each type of HSI using one-way ANOVA. Worm-detection imaging algorithms for VNIR and NIR imaging exhibited prediction accuracies of 97.00% (RI547/945) and 100.0% (RI1064/1176, SI1064-1176, RSI-I(1064-1173)/1064, and RSI-II(1064-1176)/(1064+1176)), respectively. The two HSI techniques revealed that spectral images with a pixel size of 1 × 1 mm or 2 × 2 mm had the best classification accuracy for worms. The results demonstrate that hyperspectral reflectance imaging techniques have the potential to detect worms in fresh-cut lettuce. Future research relating to this work will focus on a real-time sorting system for lettuce that can simultaneously detect various defects such as browning, worms, and slugs.

Lifted worm algorithm for the Ising model

NASA Astrophysics Data System (ADS)

Elçi, Eren Metin; Grimm, Jens; Ding, Lijie; Nasrawi, Abrahim; Garoni, Timothy M.; Deng, Youjin

2018-04-01

We design an irreversible worm algorithm for the zero-field ferromagnetic Ising model by using the lifting technique. We study the dynamic critical behavior of an energylike observable on both the complete graph and toroidal grids, and compare our findings with reversible algorithms such as the Prokof'ev-Svistunov worm algorithm. Our results show that the lifted worm algorithm improves the dynamic exponent of the energylike observable on the complete graph and leads to a significant constant improvement on toroidal grids.

Uncoupling of oxidative stress resistance and lifespan in long-lived isp-1 mitochondrial mutants in Caenorhabditis elegans.

PubMed

Dues, Dylan J; Schaar, Claire E; Johnson, Benjamin K; Bowman, Megan J; Winn, Mary E; Senchuk, Megan M; Van Raamsdonk, Jeremy M

2017-07-01

Mutations affecting components of the mitochondrial electron transport chain have been shown to increase lifespan in multiple species including the worm Caenorhabditis elegans. While it was originally proposed that decreased generation of reactive oxygen species (ROS) resulting from lower rates of electron transport could account for the observed increase in lifespan, recent evidence indicates that ROS levels are increased in at least some of these long-lived mitochondrial mutants. Here, we show that the long-lived mitochondrial mutant isp-1 worms have increased resistance to oxidative stress. Our results suggest that elevated ROS levels in isp-1 worms cause the activation of multiple stress-response pathways including the mitochondrial unfolded protein response, the SKN-1-mediated stress response, and the hypoxia response. In addition, these worms have increased expression of specific antioxidant enzymes, including a marked upregulation of the inducible superoxide dismutase genes sod-3 and sod-5. Examining the contribution of sod-3 and sod-5 to the oxidative stress resistance in isp-1 worms revealed that loss of either of these genes increased resistance to oxidative stress, but not other forms of stress. Deletion of sod-3 or sod-5 decreased the lifespan of isp-1 worms and further exacerbated their slow physiologic rates. Thus, while deletion of sod-3 and sod-5 genes has little impact on stress resistance, physiologic rates or lifespan in wild-type worms, these genes are required for the longevity of isp-1 worms. Overall, this work shows that the increased resistance to oxidative stress in isp-1 worms does not account for their longevity, and that resistance to oxidative stress can be experimentally dissociated from lifespan. Copyright © 2017 Elsevier Inc. All rights reserved.

Dew Worms in the White Nights

USDA-ARS?s Scientific Manuscript database

Lumbricus terrestris L. (the dew worm) forages, mates and migrates on the soil surface during the night. Its distribution covers a broad latitudinal gradient and variation in day length conditions. Since soil-surface activity is crucial for the survival and reproduction of dew worms, it is conceivab...

Effect of time on migration of Oesophagostomum spp. and Hyostrongylus rubidus out of agar-gel.

PubMed

Nosal, P; Christensen, C M; Nansen, P

1998-01-01

The agar-gel migration technique has previously been described, however, aspects regarding the effect of timing on worm migration needed further scrutiny. In the first experiment, pigs inoculated with Oesophagostomum dentatum were slaughtered simultaneously and their intestines stored at 21-23 degrees C until processed pairwise 2, 4, 6, 8, 12 and 18 h after slaughter. More than 95% of the worms migrated out of the agar if processed within 6 h. In the second experiment, intestines were treated immediately after slaughter and the migratory speed of adult worms or 4th-stage larvae of O. dentatum or O. quadrispinulatum, or adult Hyostrongylus rubidus were studied. For both Oesophagostomum species, more than 90% of the worms were recovered within 1 h. H. rubidus was significantly slower; however, approximately 98% of the worms had migrated out of the agar-gel by 20 h. This information is essential in planning experiments where recovery of live worms is of value.

Hairworm anti-predator strategy: a study of causes and consequences.

PubMed

Ponton, F; Lebarbenchon, C; Lefèvre, T; Thomas, F; Duneau, D; Marché, L; Renault, L; Hughes, D P; Biron, D G

2006-11-01

One of the most fascinating anti-predator responses displayed by parasites is that of hairworms (Nematomorpha). Following the ingestion of the insect host by fish or frogs, the parasitic worm is able to actively exit both its host and the gut of the predator. Using as a model the hairworm, Paragordius tricuspidatus, (parasitizing the cricket Nemobius sylvestris) and the fish predator Micropterus salmoïdes, we explored, with proteomics tools, the physiological basis of this anti-predator response. By examining the proteome of the parasitic worm, we detected a differential expression of 27 protein spots in those worms able to escape the predator. Peptide Mass Fingerprints of candidate protein spots suggest the existence of an intense muscular activity in escaping worms, which functions in parallel with their distinctive biology. In a second step, we attempted to determine whether the energy expended by worms to escape the predator is traded off against its reproductive potential. Remarkably, the number of offspring produced by worms having escaped a predator was not reduced compared with controls.

The Effect of Macrocyclic Lactones-Ivermectin Exposure on Egg Hatching and Larval Development of Caenorhabditis elegans.

PubMed

Zain, Mariani Mohd; Yahaya, Zary Shariman; Him, Nik Ahmad Irwan Izzauddin Nik

2016-11-01

To date, the ivermectin resistance in nematode parasites has been reported and many studies are carried out to determine the causes of this problem. A free-living Caenorhabditis elegans is used as a model system for this study to investigate the response of C. elegans to ivermectin exposure by using larval development assay. Worms were exposed to ivermectin at concentration from 1 ng/mL to 10 ng/mL and dimethyl sulphoxide (DMSO) as a control. The developments of the worms were monitored for 24, 48, 72, and 96 hours until the worms become adults. Results indicated that worms' growth began to be affected by ivermectin at a concentration of 5 ng/mL, while at the concentration of 6, 7, 8, 9, and 10 ng/mL, the growth of worms were inhibited compared to control worms. Further study of the protein expression in C. elegans should be done to investigate the up-regulated and down-regulated proteins involve in ivermectin resistance.

WormQTL—public archive and analysis web portal for natural variation data in Caenorhabditis spp

PubMed Central

Snoek, L. Basten; Van der Velde, K. Joeri; Arends, Danny; Li, Yang; Beyer, Antje; Elvin, Mark; Fisher, Jasmin; Hajnal, Alex; Hengartner, Michael O.; Poulin, Gino B.; Rodriguez, Miriam; Schmid, Tobias; Schrimpf, Sabine; Xue, Feng; Jansen, Ritsert C.; Kammenga, Jan E.; Swertz, Morris A.

2013-01-01

Here, we present WormQTL (http://www.wormqtl.org), an easily accessible database enabling search, comparative analysis and meta-analysis of all data on variation in Caenorhabditis spp. Over the past decade, Caenorhabditis elegans has become instrumental for molecular quantitative genetics and the systems biology of natural variation. These efforts have resulted in a valuable amount of phenotypic, high-throughput molecular and genotypic data across different developmental worm stages and environments in hundreds of C. elegans strains. WormQTL provides a workbench of analysis tools for genotype–phenotype linkage and association mapping based on but not limited to R/qtl (http://www.rqtl.org). All data can be uploaded and downloaded using simple delimited text or Excel formats and are accessible via a public web user interface for biologists and R statistic and web service interfaces for bioinformaticians, based on open source MOLGENIS and xQTL workbench software. WormQTL welcomes data submissions from other worm researchers. PMID:23180786

WormQTL--public archive and analysis web portal for natural variation data in Caenorhabditis spp.

PubMed

Snoek, L Basten; Van der Velde, K Joeri; Arends, Danny; Li, Yang; Beyer, Antje; Elvin, Mark; Fisher, Jasmin; Hajnal, Alex; Hengartner, Michael O; Poulin, Gino B; Rodriguez, Miriam; Schmid, Tobias; Schrimpf, Sabine; Xue, Feng; Jansen, Ritsert C; Kammenga, Jan E; Swertz, Morris A

2013-01-01

Here, we present WormQTL (http://www.wormqtl.org), an easily accessible database enabling search, comparative analysis and meta-analysis of all data on variation in Caenorhabditis spp. Over the past decade, Caenorhabditis elegans has become instrumental for molecular quantitative genetics and the systems biology of natural variation. These efforts have resulted in a valuable amount of phenotypic, high-throughput molecular and genotypic data across different developmental worm stages and environments in hundreds of C. elegans strains. WormQTL provides a workbench of analysis tools for genotype-phenotype linkage and association mapping based on but not limited to R/qtl (http://www.rqtl.org). All data can be uploaded and downloaded using simple delimited text or Excel formats and are accessible via a public web user interface for biologists and R statistic and web service interfaces for bioinformaticians, based on open source MOLGENIS and xQTL workbench software. WormQTL welcomes data submissions from other worm researchers.

From Flowers to Worms: Understanding Nature's Cycle.

ERIC Educational Resources Information Center

Texas Child Care, 1995

1995-01-01

Gardening helps children learn how plants sprout, grow, bloom, and then wither away, leaving seeds behind. Participating in this natural process allows children to experience the stages of life. Suggested gardening activities include studying dandelions, focusing on culture for garden plant selection, and constructing a worm box or worm terrarium…

7 CFR 51.2335 - Grades.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) Well formed. (2) Free From: (i) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv...) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv) Freezing injury; (v) Internal...) Carefully packed; (v) Fairly clean; and, (vi) Not badly misshapen. (2) Free From: (i) Worm holes; (ii...

7 CFR 51.2335 - Grades.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) Well formed. (2) Free From: (i) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv...) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv) Freezing injury; (v) Internal...) Carefully packed; (v) Fairly clean; and, (vi) Not badly misshapen. (2) Free From: (i) Worm holes; (ii...

Local structure of numerically generated worm hole spacetime.

NASA Astrophysics Data System (ADS)

Siino, M.

The author investigates the evolution of the apparent horizons in a numerically gererated worm hole spacetime. The behavior of the apparent horizons is affected by the dynamics of the matter field. By using the local mass of the system, he interprets the evolution of the worm hole structure.

7 CFR 51.2335 - Grades.

Code of Federal Regulations, 2011 CFR

2011-01-01

...: (i) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv) Freezing injury; (v...) Carefully packed; (v) Clean; and, (vi) Fairly well formed. (2) Free From: (i) Worm holes; (ii) Broken skins..., (vi) Not badly misshapen. (2) Free From: (i) Worm holes; (ii) Broken skins which are not healed; (iii...

7 CFR 51.2335 - Grades.

Code of Federal Regulations, 2012 CFR

2012-01-01

...: (i) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv) Freezing injury; (v...) Carefully packed; (v) Clean; and, (vi) Fairly well formed. (2) Free From: (i) Worm holes; (ii) Broken skins..., (vi) Not badly misshapen. (2) Free From: (i) Worm holes; (ii) Broken skins which are not healed; (iii...

7 CFR 51.2335 - Grades.

Code of Federal Regulations, 2010 CFR

2010-01-01

...: (i) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv) Freezing injury; (v...) Carefully packed; (v) Clean; and, (vi) Fairly well formed. (2) Free From: (i) Worm holes; (ii) Broken skins..., (vi) Not badly misshapen. (2) Free From: (i) Worm holes; (ii) Broken skins which are not healed; (iii...

Fluorescence hyperspectral imaging technique for the foreign substance detection on fresh-cut lettuce

USDA-ARS?s Scientific Manuscript database

Nondestructive methods based on fluorescence hyperspectral imaging (HSI) techniques were developed in order to detect worms on fresh-cut lettuce. The optimal wavebands for detecting worms on fresh-cut lettuce were investigated using the one-way ANOVA analysis and correlation analysis. The worm detec...

Guinea worm (Dracunculus medinensis) eradication: a pilot study conducted at the Ohaukwu Local Government Areas, Ebonyi State, Nigeria, West Africa.

PubMed

Ogamdi, S O; Onwe, F

2001-01-01

The incidence and the prevalence of Guinea worm disease, a major cause of disability and a frequent cause of serious permanent deformity, were both drastically reduced in Ohaukwu Local Government Communities, with the provision (through bore holes) of a safer form of drinking water. Since 1986, the Carter Center program has been working to eradicate Guinea worm. The bore holes were dug through the Wasatan Project, a Japanese-funded grant awarded to the Enugu State Ministry of Health to help provide safer drinking water in the local communities. Bore holes were dug in several communities in Ohaukwu Local Government Areas between January 1991 and June 1991. The number of Guinea worm cases in the selected communities was ascertained and recorded by health workers. There was more than a 90% reduction in the number of Guinea worm (Dracunculus medinensis) cases after one year. Data collection began in June 1991, shortly after the completion of bore holes in the selected communities. By December 1998, when one of the villages was spot checked for Guinea worm infection, no active case was found. There is a need for post evaluation of all the villages studied to determine the current prevalence of Guinea worm disease.

Microfluidic Devices in Advanced Caenorhabditis elegans Research.

PubMed

Muthaiyan Shanmugam, Muniesh; Subhra Santra, Tuhin

2016-08-02

The study of model organisms is very important in view of their potential for application to human therapeutic uses. One such model organism is the nematode worm, Caenorhabditis elegans. As a nematode, C. elegans have ~65% similarity with human disease genes and, therefore, studies on C. elegans can be translated to human, as well as, C. elegans can be used in the study of different types of parasitic worms that infect other living organisms. In the past decade, many efforts have been undertaken to establish interdisciplinary research collaborations between biologists, physicists and engineers in order to develop microfluidic devices to study the biology of C. elegans. Microfluidic devices with the power to manipulate and detect bio-samples, regents or biomolecules in micro-scale environments can well fulfill the requirement to handle worms under proper laboratory conditions, thereby significantly increasing research productivity and knowledge. The recent development of different kinds of microfluidic devices with ultra-high throughput platforms has enabled researchers to carry out worm population studies. Microfluidic devices primarily comprises of chambers, channels and valves, wherein worms can be cultured, immobilized, imaged, etc. Microfluidic devices have been adapted to study various worm behaviors, including that deepen our understanding of neuromuscular connectivity and functions. This review will provide a clear account of the vital involvement of microfluidic devices in worm biology.

Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide.

PubMed

Kim, Gun-Hee; Lee, Jeong-Won; Seo, Tae-Il

2013-05-10

Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this study, the mechanical characteristic analysis of the glass-reinforced plastic worm wheel, according to the contents of glass fiber, is performed by analytic and experimental methods. In the case of the glass fiber-reinforced resin, the orientation and contents of glass fibers can influence the mechanical properties. For the characteristic prediction of plastic worm wheel, computer-aided engineering (CAE) analysis processes such as structural and injection molding analysis were executed with the polyamide resin reinforcement glass fiber (25 wt %, 50 wt %). The injection mold for fabricating the prototype plastic worm wheel was designed and made to reflect the CAE analysis results. Finally, the durability of prototype plastic worm wheel fabricated by the injection molding process was evaluated by the experimental method and the characteristics according to the glass fiber contents.

Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide

PubMed Central

Kim, Gun-Hee; Lee, Jeong-Won; Seo, Tae-Il

2013-01-01

Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this study, the mechanical characteristic analysis of the glass-reinforced plastic worm wheel, according to the contents of glass fiber, is performed by analytic and experimental methods. In the case of the glass fiber-reinforced resin, the orientation and contents of glass fibers can influence the mechanical properties. For the characteristic prediction of plastic worm wheel, computer-aided engineering (CAE) analysis processes such as structural and injection molding analysis were executed with the polyamide resin reinforcement glass fiber (25 wt %, 50 wt %). The injection mold for fabricating the prototype plastic worm wheel was designed and made to reflect the CAE analysis results. Finally, the durability of prototype plastic worm wheel fabricated by the injection molding process was evaluated by the experimental method and the characteristics according to the glass fiber contents. PMID:28809248

Praziquantel decreases fecundity in Schistosoma mansoni adult worms that survive treatment: evidence from a laboratory life-history trade-offs selection study.

PubMed

Lamberton, Poppy H L; Faust, Christina L; Webster, Joanne P

2017-06-16

Mass drug administration of praziquantel is the World Health Organization's endorsed control strategy for schistosomiasis. A decade of annual treatments across sub-Saharan Africa has resulted in significant reductions of infection prevalence and intensity levels, although 'hotspots' remain. Repeated drug treatments place strong selective pressures on parasites, which may affect life-history traits that impact transmission dynamics. Understanding drug treatment responses and the evolution of such traits can help inform on how to minimise the risk of drug resistance developing, maximise sustainable control programme success, and improve diagnostic protocols. We performed a four-generation Schistosoma mansoni praziquantel selection experiment in mice and snails. We used three S. mansoni lines: a praziquantel-resistant isolate (R), a praziquantel-susceptible isolate (S), and a co-infected line (RS), under three treatment regimens: untreated, 25 mg/kg praziquantel, or 50 mg/kg praziquantel. Life-history traits, including parasite adult-worm establishment, survival, reproduction (fecundity), and associated morbidity, were recorded in mice across all four generations. Predictor variables were tested in a series of generalized linear mixed effects models to determine which factors had a significant influence on parasite life-history traits in definitive hosts under different selection regimes. Praziquantel pressure significantly reduced adult-worm burdens across all generations and isolates, including within R-lines. However, previous drug treatment resulted in an increase in adult-worm establishment with increasing generation from P1 to F3. The highest worm numbers were in the co-infected RS line. Praziquantel treatment decreased adult-worm burden, but had a larger negative impact on the mean daily number of miracidia, a proxy for fecundity, across all three parasite isolates. Our predicted cost of resistance was not supported by the traits we measured within the murine host. We did not find evidence for negative adult worm density-dependent effects on fecundity. In contrast, of the adult worms that survived treatment, even low doses of praziquantel significantly reduced adult-worm fecundity. Such reductions in worm fecundity post treatment suggest that egg - based measures of drug efficacy, such as Kato-Katz, may overestimate the short-term effect of praziquantel on adult - worm burdens. These findings have important implications for S. mansoni transmission control, diagnostic protocols, and the potential for undetected selection toward drug resistance.

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

A new species of Paraonis and an annotated checklist of polychaetes from mangroves of the Brazilian Amazon Coast (Annelida, Paraonidae)

PubMed Central

Ribeiro, Rannyele Passos; Alves, Paulo Ricardo; de Almeida, Zafira da Silva; Ruta, Christine

2018-01-01

Abstract The polychaete fauna from the mangroves of the Amazon Coast in Maranhão state, Brazil, is reported in this study. Fourteen species are listed, namely Alitta succinea (Leuckart, 1847); Arabella (Arabella) iricolor Montagu, 1804; Capitella capitata (Fabricius, 1780) complex; Exogone (Exogone) breviantennata Hartmann-Schröder, 1959; Heteromastus filiformis (Claparède, 1864); Isolda pulchella Müller, 1858; Mediomastus californiensis Hartman, 1944; Namalycastis fauveli Nageswara Rao, 1981; Namalycastis geayi (Gravier, 1901); Namalycastis senegalensis (Saint-Joseph, 1901); Nephtys simoni Perkins, 1980; Paraonis amazonica sp. n.; Sigambra bassi (Hartman, 1945); and Sigambra grubii Müller, 1858. Among them, Namalycastis fauveli and Namalycastis geayi are recorded for the first time in Brazil. Paraonis amazonica sp. n. is a new species for science, characterized by a rounded prostomium, 4–8 pairs of foliaceous branchiae, absent eyes, and two types of modified neurochaetae, acicular and hook-shaped. PMID:29674886

Isolation of bacterial metabolites as natural inducers for larval settlement in the marine polychaete Hydroides elegans (Haswell).

PubMed

Harder, Tilmann; Lau, Stanley Chun Kwan; Dahms, Hans-Uwe; Qian, Pei-Yuan

2002-10-01

The bacterial component of marine biofilms plays an important role in the induction of larval settlement in the polychaete Hydroides elegans. In this study, we provide experimental evidence that bacterial metabolites comprise the chemical signal for larval settlement. Bacteria were isolated from biofilms, purified and cultured according to standard procedures. Bacterial metabolites were isolated from spent culture broth by chloroform extraction as well as by closed-loop stripping and adsorption of volatile components on surface-modified silica gel. A pronounced biological activity was exclusively observed when concentrated metabolites were adsorbed on activated charcoal. Larvae did not respond to waterbome metabolites when prevented from contacting the bacterial film surface. These results indicate that an association of the chemical signal with a sorbent-like substratum may be an essential cofactor for the expression of biological activity. The functional role of bacterial exopolymers as an adsorptive matrix for larval settlement signals is discussed.

Unusual benthic fauna associated with a whale fall in Monterey Canyon, California

NASA Astrophysics Data System (ADS)

Goffredi, Shana K.; Paull, Charles K.; Fulton-Bennett, Kim; Hurtado, Luis A.; Vrijenhoek, Robert C.

2004-10-01

On February 6, 2002, we discovered an unusual assemblage of deep-sea animals associated with a well-preserved carcass of a gray whale (Eschrichtius robustus) at 2891 m depth in the axis of Monterey Canyon, California. The 9-10 m long carcass was found approximately 31 km off shore, where it settled to the bottom against the northern wall of the canyon's sedimented floor. This carcass delivered approximately 20,000 kg of organic material to a typically food-limited seafloor. Particularly noteworthy were the low occurrence of large mobile scavengers, the large number of opportunistic deep-sea species, and an abundance of unusual polychaetes. Two of these polychaetes, a spionid and a siboglinid, are new to science. Since this discovery, we visited the whale fall on two subsequent occasions (March and October 2002) to document faunal community changes in one of the deepest large food falls known to date.

[Benthic fauna associated to a Thalassia testudinum (Hydrocharitaceae) bed in Parque Nacional Morrocoy, Venezuela].

PubMed

Rodríguez, C; Villamizar, E

2000-12-01

The benthic fauna and diel variation in a shallow seagrass bed (Thalassia testudinum) were studied in Playa Mero, Venezuela. Samples of organisms and sediments were taken using PVC cylinders, 5cm in diameter, along a transect perpendicular to the coast. Seagrass cover, shoot density and biomass were estimated. The seagrass cover was homogeneous along the transect. The intermediate zone had the highest number of shoots and of above-ground and rhizome biomass. Composition and abundance of benthic organisms were related with seagrass and sediment characteristics. Sediment organic matter content and organism abundance were highest near the shore Molluscs, polychaetes, oligochaetes and nematodes were the most abundant groups. Species richness was higher in daytime (40 versus 28 at night). Gastropods were the most abundant organisms both at day and night while polychaetes and crustaceans increased during the day, and holoturids were more numerous at night.

Effectiveness of copper oxide wire particles for Haemonchus contortus control in sheep.

PubMed

Knox, M R

2002-04-01

To assess the efficacy of copper oxide wire particles (COWP) for the control of H contortus infections in grazing sheep. In experiment 1, 40 worm-free Merino hoggets (11 to 12 months of age) were divided into four equal groups and allocated to separate 0.8 ha pasture plots. Two groups then received 2.5 g COWP whereas the other two groups were untreated. From 1 week after COWP treatment all lambs received a weekly infection of 2000 H contortus larvae. At week 8, six sheep from the untreated group were then allocated to two groups and treated with either 2.5 or 5.0 g of COWP to establish therapeutic efficacy of treatment. Experiment 2 followed a similar protocol but was conducted with 40 worm-free Merino lambs (3 to 4 months of age) and no assessment of therapeutic efficacy was made. In experiment 1 no significant difference in faecal worm egg counts was observed between treatments and faecal worm egg counts remained less than 3000 epg in all animals. Total worm counts were reduced by 37% by COWP treatment (P = 0.055). Both 2.5 g and 5.0 g doses of COWP at 8 weeks of infection reduced faecal worm egg counts by > 85% with the higher dose giving an earlier response to treatment. In experiment 2, faecal worm egg counts at 4 and 6 weeks were reduced by more than 90% in the COWP treated lambs and worm numbers were 54% lower after 6 weeks when all remaining untreated lambs had to be treated for haemonchosis. Mean faecal worm egg counts in the COWP lambs remained below 3500 epg and clinical disease did not develop in the majority of lambs before the end of the experiment at 10 weeks. Treatment with COWPs appears to have the potential to reduce establishment and worm fecundity of Haemonchus spp for an extended period and may offer livestock producers a supplementary means of reducing larval contamination of pasture particularly in areas where anthelmintic resistance is a problem and copper supplementation is likely to be beneficial.

Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California: 2014

USGS Publications Warehouse

Cain, Daniel J.; Thompson, Janet K.; Crauder, Jeff; Parcheso, Francis; Stewart, Robin; Kleckner, Amy E.; Dyke, Jessica; Hornberger, Michelle I.; Luoma, Samuel N.

2015-01-01

Analyses of the benthic community structure of a mudflat in South San Francisco Bay over a 40-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinel clam, M. petalum, from the same area. Analysis of M. petalum shows increases in reproductive activity concurrent with the decline in metal concentrations in the tissues of this organism. Reproductive activity is presently stable (2014), with almost all animals initiating reproduction in the fall and spawning the following spring. The entire infaunal community has shifted from being dominated by several opportunistic species to a community where the species are more similar in abundance, a pattern that indicates a more stable community that is subjected to fewer stressors. In addition, two of the opportunistic species (Ampelisca abdita and Streblospio benedicti) that brood their young and live on the surface of the sediment in tubes have shown a continual decline in dominance coincident with the decline in metals; both species had short-lived rebounds in abundance in 2008, 2009, and 2010. Heteromastus filiformis (a subsurface polychaete worm that lives in the sediment, consumes sediment and organic particles residing in the sediment, and reproduces by laying its eggs on or in the sediment) showed a concurrent increase in dominance and, in the last several years before 2008, showed a stable population. H. filiformis abundance increased slightly in 2011–2012 and returned to pre-2011 numbers in 2014. An unidentified disturbance occurred on the mudflat in early 2008 that resulted in the loss of the benthic animals, except for deep-dwelling animals like Macoma petalum. However, within two months of this event animals returned to the mudflat. The resilience of the community suggested that the disturbance was not due to a persistent toxin or to anoxia. The reproductive mode of most species present in 2014 is reflective of species that were available either as pelagic larvae or as mobile adults. Although oviparous species were lower in number in this group, the authors hypothesize that these species will return slowly as more species move back into the area. The use of functional ecology was highlighted in the 2014 benthic community data, which showed that the animals that have now returned to the mudflat are those that can respond successfully to a physical, nontoxic disturbance. Today, community data show a mix of species that consume the sediment, or filter feed, have pelagic larvae that must survive landing on the sediment, and those that brood their young. USGS scientists view the 2008 disturbance event as a response by the infaunal community to an episodic natural stressor (possibly sediment accretion or a pulse of freshwater), in contrast to the long-term recovery from metal contamination. We will compare this recovery to the long-term recovery observed after the 1970’s when the decline in sediment pollutants was the dominating factor.

Near-Field Receiving Water Monitoring of Trace Metals and a Benthic Community Near the Palo Alto Regional Water Quality Control Plant in South San Francisco Bay, California: 2006

USGS Publications Warehouse

Lorenzi, Allison H.; Cain, Daniel J.; Parcheso, Francis; Thompson, Janet K.; Luoma, Samuel N.; Hornberger, Michelle I.; Dyke, Jessica; Cervantes, Raul; Shouse, Michelle K.

2007-01-01

Results reported herein include trace element concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica (Cohen and Carlton 1995)), clam reproductive activity, and benthic macroinvertebrate community structure for a mudflat one kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant in South San Francisco Bay. This report includes data collected for the period January 2006 to December 2006, and extends a critical long-term biogeochemical record dating back to 1974. These data serve as the basis for the City of Palo Alto's Near-Field Receiving Water Monitoring Program, initiated in 1994. Metal concentrations in both sediments and clam tissue during 2006 were consistent with results observed since 1990. Most notably, copper and silver concentrations in sediment and clam tissue increased in the last year but the values remain well within range of past data. Other metals such as chromium, nickel, vanadium, and zinc remained relatively constant throughout the year except for maximum values generally occurring in winter months (January-March). Mercury levels in sediment and clam tissue were some of the lowest seen on record. Conversely, selenium concentrations reached a maximum level but soon returned to baseline levels. In all, metal concentrations in sediments and tissue remain within past findings. There are no obvious directional trends (increasing or decreasing). Analyses of the benthic-community structure of a mudflat in South San Francisco Bay over a 31-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinel clam M. petalum from the same area. Analysis of the reproductive activity of M. petalum shows increases in reproductive activity concurrent with the decline in metal concentrations in the tissues of this organism. Reproductive activity is presently stable, with almost all animals initiating reproduction in the fall and spawning the following spring of most years. The community has shifted from being dominated by several opportunistic species to a community where the species are more similar in abundance, a pattern that suggests a more stable community that is subjected to less stress. In addition, two of the opportunistic species (Ampelisca abdita and Streblospio benedicti) that brood their young and live on the surface of the sediment in tubes, have shown a continual decline in dominance coincident with the decline in metals. Heteromastus filiformis, a subsurface polychaete worm that lives in the sediment, consumes sediment and organic particles residing in the sediment, and reproduces by laying their eggs on or in the sediment, has shown a concurrent increase in dominance. These changes in species dominance reflect a change in the community from one dominated by surface dwelling, brooding species to one with species with varying life history characteristics. For the first time since its invasion in 1986, the non-indigenous filter-feeding clam Corbula (Potamocorbula) amurensis has shown up in small, but persistent, numbers in the benthic community.

Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California; 2015

USGS Publications Warehouse

Cain, Daniel J.; Thompson, Janet K.; Crauder, Jeffrey; Parchaso, Francis; Stewart, Robin; Turner, Matthew A.; Hornberger, Michelle I.; Luoma, Samuel N.

2016-07-22

Analyses of the benthic community structure at the same mudflat over a 40-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinel clam, M. petalum, from the same area. Analysis of M. petalum shows increases in reproductive activity concurrent with the decline in metal concentrations in the tissues of this organism. Reproductive activity is presently stable (2015), with almost all animals initiating reproduction in the fall and spawning the following spring. The entire infaunal community has shifted from being dominated by several opportunistic species to a community where the species are more similar in abundance, a pattern that indicates a more stable community that is subjected to fewer stressors. In addition, two of the opportunistic species (Ampelisca abdita and Streblospio benedicti) that brood their young and live on the surface of the sediment in tubes have shown a continual decline in dominance coincident with the decline in metals; both species had short-lived rebounds in abundance in 2008, 2009, and 2010 and showed signs of increasing abundance in 2015. Heteromastus filiformis (a subsurface polychaete worm that lives in the sediment, consumes sediment and organic particles residing in the sediment, and reproduces by laying its eggs on or in the sediment) showed an increase in dominance, concurrent with the decrease in Ag and Cu concentrations, and in the last several years before 2008, showed a stable population. H. filiformis abundance increased slightly in 2011–2012 and returned to pre-2011 abundance in 2015. An unidentified disturbance occurred on the mudflat in early 2008 that resulted in the loss of the benthic animals, except for deep-dwelling animals like M. petalum. However, within two months of this event animals returned to the mudflat. The resilience of the community suggested that the disturbance was not due to a persistent toxin or to anoxia. The reproductive mode of most species present in 2015 is reflective of species that were available either as pelagic larvae or as mobile adults. Although oviparous (live-birth) species were lower in number in this group, the authors hypothesize that these species will return slowly as more species move back into the area. The use of functional ecology was highlighted in the 2015 benthic community data, which showed that the animals that have now returned to the mudflat are those that can respond successfully to a physical, nontoxic disturbance. Today, community data show a mix of species that consume the sediment, or filter feed, have pelagic larvae that must survive landing on the sediment, and those that brood their young. USGS scientists view the 2008 disturbance event as a response by the infaunal community to an episodic natural stressor (possibly sediment accretion or a pulse of freshwater), in contrast to the long-term recovery from metal contamination. We will compare this recovery to the long-term recovery observed after the 1970s when the decline in sediment pollutants was the dominating factor.

A Tissue-Specific Approach to the Analysis of Metabolic Changes in Caenorhabditis elegans

PubMed Central

Pujol, Claire; Ipsen, Sabine; Brodesser, Susanne; Mourier, Arnaud; Tolnay, Markus; Frank, Stephan; Trifunović, Aleksandra

2011-01-01

The majority of metabolic principles are evolutionarily conserved from nematodes to humans. Caenorhabditis elegans has widely accelerated the discovery of new genes important to maintain organismic metabolic homeostasis. Various methods exist to assess the metabolic state in worms, yet they often require large animal numbers and tend to be performed as bulk analyses of whole worm homogenates, thereby largely precluding a detailed studies of metabolic changes in specific worm tissues. Here, we have adapted well-established histochemical methods for the use on C. elegans fresh frozen sections and demonstrate their validity for analyses of morphological and metabolic changes on tissue level in wild type and various mutant strains. We show how the worm presents on hematoxylin and eosin (H&E) stained sections and demonstrate their usefulness in monitoring and the identification of morphological abnormalities. In addition, we demonstrate how Oil-Red-O staining on frozen worm cross-sections permits quantification of lipid storage, avoiding the artifact-prone fixation and permeabilization procedures of traditional whole-mount protocols. We also adjusted standard enzymatic stains for respiratory chain subunits (NADH, SDH, and COX) to monitor metabolic states of various C. elegans tissues. In summary, the protocols presented here provide technical guidance to obtain robust, reproducible and quantifiable tissue-specific data on worm morphology as well as carbohydrate, lipid and mitochondrial energy metabolism that cannot be obtained through traditional biochemical bulk analyses of worm homogenates. Furthermore, analysis of worm cross-sections overcomes the common problem with quantification in three-dimensional whole-mount specimens. PMID:22162770

Migratory response of Echinostoma caproni (Digenea: Echinostomatidae) to feeding by ICR mice.

PubMed

Platt, Thomas R; Quintana, Guadalupe; Rodriguez, Arianne E; Zelmer, Derek A

2013-04-01

The migratory response of Echinostoma caproni to host feeding was examined in female ICR mice. Thirty-six mice were each infected with 20 metacercariae of E. caproni . Twenty-eight days post-infection, food, but not water, was withheld for 24 hr. Mice were haphazardly divided into 4 groups of 9, and each group received one of the following treatments: (1) 0.25 g glucose, (2) access to standard lab chow, (3) 0.5 ml saline, and (4) continued fasting. Three mice from each treatment group were killed 1, 2, and 4 hr post-treatment. The intestine of each mouse was removed, flash-frozen, and stored in a conventional freezer for later examination. Intestines were partially thawed, measured, and opened longitudinally, and the position of each worm, or worm cluster was measured. The intestine was divided into equal 5% segments based on the initial measurement and locations of worms, and worm clusters were recorded from the appropriate section of the intestine for analysis. There was no significant effect of treatment in the position of worms at 1 hr. There was a posterior shift in worm position in all treatment groups at 2 hr, except in the saline-treated mice; however, only worms in the glucose-fed mice were significantly posterior to the unfed controls. From 2 to 4 hr, there was a significant anterior movement of worms in both the glucose and chow-fed mice. The data strongly suggest that E. caproni responds to the initiation of gastric activity of the host by migrating anteriorly in the ileum. The specific stimulus for this migration is unknown.

WORM - WINDOWED OBSERVATION OF RELATIVE MOTION

NASA Technical Reports Server (NTRS)

Bauer, F.

1994-01-01

The Windowed Observation of Relative Motion, WORM, program is primarily intended for the generation of simple X-Y plots from data created by other programs. It allows the user to label, zoom, and change the scale of various plots. Three dimensional contour and line plots are provided, although with more limited capabilities. The input data can be in binary or ASCII format, although all data must be in the same format. A great deal of control over the details of the plot is provided, such as gridding, size of tick marks, colors, log/semilog capability, time tagging, and multiple and phase plane plots. Many color and monochrome graphics terminals and hard copy printer/plotters are supported. The WORM executive commands, menu selections and macro files can be used to develop plots and tabular data, query the WORM Help library, retrieve data from input files, and invoke VAX DCL commands. WORM generated plots are displayed on local graphics terminals and can be copied using standard hard copy capabilities. Some of the graphics features of WORM include: zooming and dezooming various portions of the plot; plot documentation including curve labeling and function listing; multiple curves on the same plot; windowing of multiple plots and insets of the same plot; displaying a specific on a curve; and spinning the curve left, right, up, and down. WORM is written in PASCAL for interactive execution and has been implemented on a DEC VAX computer operating under VMS 4.7 with a virtual memory requirement of approximately 392K of 8 bit bytes. It uses the QPLOT device independent graphics library included with WORM. It was developed in 1988.

Seasonal population dynamics of the invasive polychaete genus Marenzelleria spp. in contrasting soft-sediment habitats

NASA Astrophysics Data System (ADS)

Kauppi, L.; Norkko, A.; Norkko, J.

2018-01-01

Three species of the invasive polychaete genus Marenzelleria are among the dominant benthic taxa in many, especially deeper, areas in the Baltic Sea. The population dynamics of the polychaetes in the Baltic are, however, still largely unknown. We conducted monthly samplings of the benthic communities and environmental parameters at five sites with differing depths and sediment characteristics in the northern Baltic Sea (59°50.896‧, 23°15.092‧) to study the population dynamics, productivity and growth of Marenzelleria spp. from April 2013 to June 2014. The species of Marenzelleria occurring at the study sites were identified by genetic analyses. At the deepest site (33 m) only M. arctia was present, while all three species were found at the shallower, muddy sites (up to 20 m depth). At the shallow (6 m) sandy site only M. viridis and M. neglecta occurred. The sites differed in the seasonal dynamics of the Marenzelleria spp. population, reflecting the different species identities. The muddy sites up to 20 m depth showed clear seasonal dynamics, with the population practically disappearing by winter, whereas more stable populations occurred at the deepest site and at the sandy site. The highest density, biomass and production were observed at the 20 m deep, organic-rich muddy site where all three species recruited. The seasonally very high densities are likely to have important consequences for organic matter processing, and species interactions at these sites. The observed high productivity of the populations has possibly facilitated their establishment, and considerably increased secondary production in especially the deeper areas.

Diversity, Abundance and Community Structure of Benthic Macro- and Megafauna on the Beaufort Shelf and Slope

PubMed Central

Nephin, Jessica; Juniper, S. Kim; Archambault, Philippe

2014-01-01

Diversity and community patterns of macro- and megafauna were compared on the Canadian Beaufort shelf and slope. Faunal sampling collected 247 taxa from 48 stations with box core and trawl gear over the summers of 2009–2011 between 50 and 1,000 m in depth. Of the 80 macrofaunal and 167 megafaunal taxa, 23% were uniques, present at only one station. Rare taxa were found to increase proportional to total taxa richness and differ between the shelf ( 100 m) where they tended to be sparse and the slope where they were relatively abundant. The macrofauna principally comprised polychaetes with nephtyid polychaetes dominant on the shelf and maldanid polychaetes (up to 92% in relative abundance/station) dominant on the slope. The megafauna principally comprised echinoderms with Ophiocten sp. (up to 90% in relative abundance/station) dominant on the shelf and Ophiopleura sp. dominant on the slope. Macro- and megafauna had divergent patterns of abundance, taxa richness ( diversity) and diversity. A greater degree of macrofaunal than megafaunal variation in abundance, richness and diversity was explained by confounding factors: location (east-west), sampling year and the timing of sampling with respect to sea-ice conditions. Change in megafaunal abundance, richness and diversity was greatest across the depth gradient, with total abundance and richness elevated on the shelf compared to the slope. We conclude that megafaunal slope taxa were differentiated from shelf taxa, as faunal replacement not nestedness appears to be the main driver of megafaunal diversity across the depth gradient. PMID:25007347

Diversity, abundance and community structure of benthic macro- and megafauna on the Beaufort shelf and slope.

PubMed

Nephin, Jessica; Juniper, S Kim; Archambault, Philippe

2014-01-01

Diversity and community patterns of macro- and megafauna were compared on the Canadian Beaufort shelf and slope. Faunal sampling collected 247 taxa from 48 stations with box core and trawl gear over the summers of 2009-2011 between 50 and 1,000 m in depth. Of the 80 macrofaunal and 167 megafaunal taxa, 23% were uniques, present at only one station. Rare taxa were found to increase proportional to total taxa richness and differ between the shelf (< 100 m) where they tended to be sparse and the slope where they were relatively abundant. The macrofauna principally comprised polychaetes with nephtyid polychaetes dominant on the shelf and maldanid polychaetes (up to 92% in relative abundance/station) dominant on the slope. The megafauna principally comprised echinoderms with Ophiocten sp. (up to 90% in relative abundance/station) dominant on the shelf and Ophiopleura sp. dominant on the slope. Macro- and megafauna had divergent patterns of abundance, taxa richness (α diversity) and β diversity. A greater degree of macrofaunal than megafaunal variation in abundance, richness and β diversity was explained by confounding factors: location (east-west), sampling year and the timing of sampling with respect to sea-ice conditions. Change in megafaunal abundance, richness and β diversity was greatest across the depth gradient, with total abundance and richness elevated on the shelf compared to the slope. We conclude that megafaunal slope taxa were differentiated from shelf taxa, as faunal replacement not nestedness appears to be the main driver of megafaunal β diversity across the depth gradient.

Physical processes dominate in shaping invertebrate assemblages in reef-associated sediments of an exposed Hawaiian coast

USGS Publications Warehouse

DeFelice, R.C.; Parrish, J.D.

2001-01-01

The invertebrate assemblages in sediments bordering exposed fringing reefs at Hanalei Bay, Kauai, Hawaii, were examined during July to September 1994. Densities of invertebrate animals larger than 0.5 mm in sediments of the bay ranged from counts of 10 260 m-2 in the fine carbonate sands of the central bay to 870 m-2 in the habitat dominated by terrigenous silt near the reef edge close to the Hanalei river mouth. Similar sediment types supported broadly similar infaunal communities. Within the primarily carbonate sediments, mean grain size and wave exposure appear to have an important influence on the community. Taxonomic richness, number of individuals, and diversity showed significant negative relationships with exposure to wave energy (as estimated by sand ripple wavelength). The number of individuals was also significantly correlated with mean grain size. Overall, polychaetes and small crustaceans were numerically dominant among the major taxonomic groups investigated. Macrophagous and microphagous polychaetes had significant, but opposite, associations with grain size. In addition, microphagous polychaetes were significantly negatively correlated with wave exposure. No habitat variable measured could explain the variation in percent composition of crustaceans or echinoderms in the sedimentary habitats. The percentage of gastropods in the community was significantly negatively correlated with grain size, grain-size standard deviation and exposure, and positively with percent organic carbon. Bivalves were significantly positively associated with depth and grain size. These strong relationships imply that, in Hanalei Bay, physical processes are especially important in influencing assemblage structure, and that community structure and composition vary continuously along environmental gradients.

An Unusual Foreign Body in the Urinary Bladder Mimicking a Parasitic Worm

PubMed Central

Schmitt, Bryan H.; Feder, Marc T.; Rokke, Denise L.; Moyer, Thomas P.

2012-01-01

We report an unusual case of a foreign body removed from the urinary bladder of a 63-year-old male which mimicked a parasitic worm. The foreign body was identified as an artificial fishing worm by morphological comparison to a similar commercially produced product and by infrared spectrum analysis. PMID:22535991

Antifilarial and Antibiotic Activities of Methanolic Extracts of Melaleuca cajuputi Flowers

PubMed Central

Al-Abd, Nazeh M.; Nor, Zurainee Mohamed; Mansor, Marzida; Hasan, MS; Kassim, Mustafa

2016-01-01

We evaluated the activity of methanolic extracts of Melaleuca cajuputi flowers against the filarial worm Brugia pahangi and its bacterial endosymbiont Wolbachia. Anti-Wolbachia activity was measured in worms and in Aedes albopictus Aa23 cells by PCR, electron microscopy, and other biological assays. In particular, microfilarial release, worm motility, and viability were determined. M. cajuputi flower extracts were found to significantly reduce Wolbachia endosymbionts in Aa23 cells, Wolbachia surface protein, and microfilarial release, as well as the viability and motility of adult worms. Anti-Wolbachia activity was further confirmed by observation of degraded and phagocytized Wolbachia in worms treated with the flower extracts. The data provided in vitro and in vivo evidence that M. cajuputi flower extracts inhibit Wolbachia, an activity that may be exploited as an alternative strategy to treat human lymphatic filariasis. PMID:27417081

Worm epidemics in wireless ad hoc networks

NASA Astrophysics Data System (ADS)

Nekovee, Maziar

2007-06-01

A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet.

Repair and Dredging of Bear Creek Marina Final Environmental Assessment

DTIC Science & Technology

2007-06-01

vegetation typically adapted for life in saturated soil conditions” (USACE, 1987). The majority of jurisdictional wetlands in the United States are...invertebrates, including amphipods, lancelets, insect larvae, mollusks, polychaetes, gastropods , shrimp, isopods, brachiopods, and crustaceans. Little is

Benthic Community Response to Hypoxia: Baseline Data

DTIC Science & Technology

2009-01-01

were represented by six different phyla, namely Annelida, Sipuncula, Arthropoda, Cnidaria , Mollusca and Echinodermata (Table II). The phylum Annelida...was solely represented by polychaetes and the phylum Cnidaria was represented solely by hydroids. However, the phylum Mollusca was represented by

Functional Mapping of Protein Kinase A Reveals Its Importance in Adult Schistosoma mansoni Motor Activity

PubMed Central

de Saram, Paulu S. R.; Ressurreição, Margarida; Davies, Angela J.; Rollinson, David; Emery, Aidan M.; Walker, Anthony J.

2013-01-01

Cyclic AMP (cAMP)-dependent protein kinase/protein kinase A (PKA) is the major transducer of cAMP signalling in eukaryotic cells. Here, using laser scanning confocal microscopy and ‘smart’ anti-phospho PKA antibodies that exclusively detect activated PKA, we provide a detailed in situ analysis of PKA signalling in intact adult Schistosoma mansoni, a causative agent of debilitating human intestinal schistosomiasis. In both adult male and female worms, activated PKA was consistently found associated with the tegument, oral and ventral suckers, oesophagus and somatic musculature. In addition, the seminal vesicle and gynaecophoric canal muscles of the male displayed activated PKA whereas in female worms activated PKA localized to the ootype wall, the ovary, and the uterus particularly around eggs during expulsion. Exposure of live worms to the PKA activator forskolin (50 µM) resulted in striking PKA activation in the central and peripheral nervous system including at nerve endings at/near the tegument surface. Such neuronal PKA activation was also observed without forskolin treatment, but only in a single batch of worms. In addition, PKA activation within the central and peripheral nervous systems visibly increased within 15 min of worm-pair separation when compared to that observed in closely coupled worm pairs. Finally, exposure of adult worms to forskolin induced hyperkinesias in a time and dose dependent manner with 100 µM forskolin significantly increasing the frequency of gross worm movements to 5.3 times that of control worms (P≤0.001). Collectively these data are consistent with PKA playing a central part in motor activity and neuronal communication, and possibly interplay between these two systems in S. mansoni. This study, the first to localize a protein kinase when exclusively in an activated state in adult S. mansoni, provides valuable insight into the intricacies of functional protein kinase signalling in the context of whole schistosome physiology. PMID:23326613

Preparation and Cross-Linking of All-Acrylamide Diblock Copolymer Nano-Objects via Polymerization-Induced Self-Assembly in Aqueous Solution

PubMed Central

2017-01-01

Various carboxylic acid-functionalized poly(N,N-dimethylacrylamide) (PDMAC) macromolecular chain transfer agents (macro-CTAs) were chain-extended with diacetone acrylamide (DAAM) by reversible addition–fragmentation chain transfer (RAFT) aqueous dispersion polymerization at 70 °C and 20% w/w solids to produce a series of PDMAC–PDAAM diblock copolymer nano-objects via polymerization-induced self-assembly (PISA). TEM studies indicate that a PDMAC macro-CTA with a mean degree of polymerization (DP) of 68 or higher results in the formation of well-defined spherical nanoparticles with mean diameters ranging from 40 to 150 nm. In contrast, either highly anisotropic worms or polydisperse vesicles are formed when relatively short macro-CTAs (DP = 40–58) are used. A phase diagram was constructed to enable accurate targeting of pure copolymer morphologies. Dynamic light scattering (DLS) and aqueous electrophoresis studies indicated that in most cases these PDMAC–PDAAM nano-objects are surprisingly resistant to changes in either solution pH or temperature. However, PDMAC40–PDAAM99 worms do undergo partial dissociation to form a mixture of relatively short worms and spheres on adjusting the solution pH from pH 2–3 to around pH 9 at 20 °C. Moreover, a change in copolymer morphology from worms to a mixture of short worms and vesicles was observed by DLS and TEM on heating this worm dispersion to 50 °C. Postpolymerization cross-linking of concentrated aqueous dispersions of PDMAC–PDAAM spheres, worms, or vesicles was performed at ambient temperature using adipic acid dihydrazide (ADH), which reacts with the hydrophobic ketone-functionalized PDAAM chains. The formation of hydrazone groups was monitored by FT-IR spectroscopy and afforded covalently stabilized nano-objects that remained intact on exposure to methanol, which is a good solvent for both blocks. Rheological studies indicated that the cross-linked worms formed a stronger gel compared to linear precursor worms. PMID:28260814

Expression of a unique drug-resistant Hsp90 ortholog by the nematode Caenorhabditis elegans.

PubMed

David, Cynthia L; Smith, Harold E; Raynes, Deborah A; Pulcini, Elizabeth J; Whitesell, Luke

2003-01-01

In all species studied to date, the function of heat shock protein 90 (Hsp90), a ubiquitous and evolutionarily conserved molecular chaperone, is inhibited selectively by the natural product drugs geldanamycin (GA) and radicicol. Crystal structures of the N-terminal region of yeast and human Hsp90 have revealed that these compounds interact with the chaperone in a Bergerat-type adenine nucleotide-binding fold shared throughout the gyrase, Hsp90, histidine kinase mutL (GHKL) superfamily of adenosine triphosphatases. To better understand the consequences of disrupting Hsp90 function in a genetically tractable multicellular organism, we exposed the soil-dwelling nematode Caenorhabditis elegans to GA under a variety of conditions designed to optimize drug uptake. Mutations in the gene encoding C elegans Hsp90 affect larval viability, dauer development, fertility, and life span. However, exposure of worms to GA produced no discernable phenotypes, although the amino acid sequence of worm Hsp90 is 85% homologous to that of human Hsp90. Consistent with this observation, we found that solid phase-immobilized GA failed to bind worm Hsp90 from worm protein extracts or when translated in a rabbit reticulocyte lysate system. Further, affinity precipitation studies using chimeric worm-vertebrate fusion proteins or worm C-terminal truncations expressed in reticulocyte lysate revealed that the conserved nucleotide-binding fold of worm Hsp90 exhibits the novel ability to bind adenosine triphosphate but not GA. Despite its unusual GA resistance, worm Hsp90 appeared fully functional when expressed in a vertebrate background. It heterodimerized with its vertebrate counterpart and showed no evidence of compromising its essential cellular functions. Heterologous expression of worm Hsp90 in tumor cells, however, did not render them GA resistant. These findings provide new insights into the nature of unusual N-terminal nucleotide-binding fold of Hsp90 and suggest that target-related drug resistance is unlikely to emerge in patients receiving GA-like chemotherapeutic agents.

Study of the Formation and Solution Properties of Worm-Like Micelles Formed Using Both N-Hexadecyl-N-Methylpiperidinium Bromide-Based Cationic Surfactant and Anionic Surfactant

PubMed Central

Yan, Zhihu; Dai, Caili; Feng, Haishun; Liu, Yifei; Wang, Shilu

2014-01-01

The viscoelastic properties of worm-like micelles formed by mixing the cationic surfactant N-hexadecyl-N-methylpiperidinium bromide (C16MDB) with the anionic surfactant sodium laurate (SL) in aqueous solutions were investigated using rheological measurements. The effects of sodium laurate and temperature on the worm-like micelles and the mechanism of the observed shear thinning phenomenon and pseudoplastic behavior were systematically investigated. Additionally, cryogenic transmission electron microscopy images further ascertained existence of entangled worm-like micelles. PMID:25296131

Social behaviour and collective motion in plant-animal worms.

PubMed

Franks, Nigel R; Worley, Alan; Grant, Katherine A J; Gorman, Alice R; Vizard, Victoria; Plackett, Harriet; Doran, Carolina; Gamble, Margaret L; Stumpe, Martin C; Sendova-Franks, Ana B

2016-02-24

Social behaviour may enable organisms to occupy ecological niches that would otherwise be unavailable to them. Here, we test this major evolutionary principle by demonstrating self-organizing social behaviour in the plant-animal, Symsagittifera roscoffensis. These marine aceol flat worms rely for all of their nutrition on the algae within their bodies: hence their common name. We show that individual worms interact with one another to coordinate their movements so that even at low densities they begin to swim in small polarized groups and at increasing densities such flotillas turn into circular mills. We use computer simulations to: (i) determine if real worms interact socially by comparing them with virtual worms that do not interact and (ii) show that the social phase transitions of the real worms can occur based only on local interactions between and among them. We hypothesize that such social behaviour helps the worms to form the dense biofilms or mats observed on certain sun-exposed sandy beaches in the upper intertidal of the East Atlantic and to become in effect a super-organismic seaweed in a habitat where macro-algal seaweeds cannot anchor themselves. Symsagittifera roscoffensis, a model organism in many other areas in biology (including stem cell regeneration), also seems to be an ideal model for understanding how individual behaviours can lead, through collective movement, to social assemblages. © 2016 The Author(s).

Influence of ecological factors on prevalence of meningeal worm (Parelaphostrongylus tenuis infection in South Dakota, USA

USGS Publications Warehouse

Jacques, Christopher N.; Jenks, Jonathan A.; Grovenburg, Troy W.; Klaver, Robert W.; Dubay, Shelli A.

2015-01-01

The meningeal worm (Parelaphostrongylus tenuis) is a nematode parasite that commonly infects white-tailed deer (Odocoileus virginianus; WTD) throughout the deciduous forest biome and deciduous-coniferous ecotone of eastern and central North America; the species is not known to occur west of the grassland biome of central North America. We used county-specific prevalence data to evaluate potential effects of landscape and climatologic factors on the spatial distribution of meningeal worm infection in South Dakota, US. Probability of infection increased 4-fold between eastern and western South Dakota and 1.3-fold for each 1-cm increase in summer precipitation. Sixty-three percent of WTD had only a single worm in the cranium. Expansion of meningeal worm infection across western South Dakota may be inherently low due to the combined effects of arid climate and potential attributes of the Missouri River that limit regional movements by infected WTD. Use of landscape genetic analyses to identify potential relationships between landscape features and population genetic structure of infected deer and parasites may contribute to a greater understanding of regional heterogeneity in meningeal worm infection rates across South Dakota, particularly in counties adjacent to the Missouri River. Future research evaluating heterogeneity in prevalence and intensity of infection between fawn and yearling deer, and the potential role of yearling male deer as dispersal agents of meningeal worms across the Missouri River, also is warranted.

Community assembly of the worm gut microbiome

NASA Astrophysics Data System (ADS)

Gore, Jeff

It has become increasingly clear that human health is strongly influenced by the bacteria that live within the gut, known collectively as the gut microbiome. This complex community varies tremendously between individuals, but understanding the sources that lead to this heterogeneity is challenging. To address this challenge, we are using a bottom-up approach to develop a predictive understanding of how the microbiome assembles and functions within a simple and experimentally tractable gut, the gut of the worm C. elegans. We have found that stochastic community assembly in the C. elegansintestine is sufficient to produce strong inter-worm heterogeneity in community composition. When worms are fed with two neutrally-competing fluorescently labeled bacterial strains, we observe stochastically-driven bimodality in community composition, where approximately half of the worms are dominated by each bacterial strain. A simple model incorporating stochastic colonization suggests that heterogeneity between worms is driven by the low rate at which bacteria successfully establish new intestinal colonies. We can increase this rate experimentally by feeding worms at high bacterial density; in these conditions the bimodality disappears. We have also characterized all pairwise interspecies competitions among a set of eleven bacterial species, illuminating the rules governing interspecies community assembly. These results demonstrate the potential importance of stochastic processes in bacterial community formation and suggest a role for C. elegans as a model system for ecology of host-associated communities.

A decade of the World Register of Marine Species – General insights and experiences from the Data Management Team: Where are we, what have we learned and how can we continue?

PubMed Central

Vanhoorne, Bart; Decock, Wim; Vranken, Sofie; Lanssens, Thomas; Dekeyzer, Stefanie; Verfaille, Kevin; Horton, Tammy; Kroh, Andreas; Hernandez, Francisco; Mees, Jan

2018-01-01

The World Register of Marine Species (WoRMS) celebrated its 10th anniversary in 2017. WoRMS is a unique database: there is no comparable global database for marine species, which is driven by a large, global expert community, is supported by a Data Management Team and can rely on a permanent host institute, dedicated to keeping WoRMS online. Over the past ten years, the content of WoRMS has grown steadily, and the system currently contains more than 242,000 accepted marine species. WoRMS has not yet reached completeness: approximately 2,000 newly described species per year are added, and editors also enter the remaining missing older names–both accepted and unaccepted–an effort amounting to approximately 20,000 taxon name additions per year. WoRMS is used extensively, through different channels, indicating that it is recognized as a high-quality database on marine species information. It is updated on a daily basis by its Editorial Board, which currently consists of 490 taxonomic and thematic experts located around the world. Owing to its unique qualities, WoRMS has become a partner in many large-scale initiatives including OBIS, LifeWatch and the Catalogue of Life, where it is recognized as a high-quality and reliable source of information for marine taxonomy. PMID:29624577

Census of bacterial microbiota associated with the glacier ice worm Mesenchytraeus solifugus.

PubMed

Murakami, Takumi; Segawa, Takahiro; Bodington, Dylan; Dial, Roman; Takeuchi, Nozomu; Kohshima, Shiro; Hongoh, Yuichi

2015-03-01

The glacier ice worm, Mesenchytraeus solifugus, is a unique annelid, inhabiting only snow and ice in North American glaciers. Here, we analyzed the taxonomic composition of bacteria associated with M. solifugus based on the 16S rRNA gene. We analyzed four fixed-on-site and 10 starved ice worm individuals, along with glacier surface samples. In total, 1341 clones of 16S rRNA genes were analyzed for the ice worm samples, from which 65 bacterial phylotypes (99.0% cut-off) were identified. Of these, 35 phylotypes were closely related to sequences obtained from their habitat glacier and/or other components of cryosphere; whereas three dominant phylotypes were affiliated with animal-associated lineages of the class Mollicutes. Among the three, phylotype Ms-13 shared less than 89% similarity with database sequences and was closest to a gut symbiont of a terrestrial earthworm. Using fluorescence in situ hybridization, Ms-13 was located on the gut wall surface of the ice worms. We propose a novel genus and species, 'Candidatus Vermiplasma glacialis', for this bacterium. Our results raise the possibility that the ice worm has exploited indigenous glacier bacteria, while several symbiotic bacterial lineages have maintained their association with the ice worm during the course of adaptive evolution to the permanently cold environment. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

In vitro antischistosomal activity of venom from the Egyptian snake Cerastes cerastes.

PubMed

Hassan, Ehssan Ahmed; Abdel-Rahman, Mohamed Ahmed; Ibrahim, Mohamed Moussa; Soliman, Maha Farid Mohamed

2016-01-01

We studied the potential in vitro antischistosomal activity of Cerastes cerastes venom on adult Schistosoma mansoni worms. Live specimens of the horned viper snake, C. cerastes were collected from the Aswan Governorate (Egypt). Venom was collected from snakes by manual milking. Worms of S. mansoni were obtained from infected hamsters by perfusion and isolated from blood using phosphate buffer. Mortality rates of worms were monitored after 3 days of exposure to snake venom at LC50 and various sublethal concentrations (10, 5, 2.5µg/ml). Scanning electron microscopy was used to investigate tegumental changes in treated worms after exposure to LC50 doses of venom. The LC50 of C. cerastes venom was 21.5µg/ml. The effect of C. cerastes venom on Schistosoma worms varied according to their sex. The mortality rate of male and female worms after 48-h exposure was 83.3% and 50%, respectively. LC50 of C. cerastes venom induced mild to severe tegumental damage in Schistosoma worms in the form of destruction of the oral sucker, shrinkage and erosion of the tegument, and loss of some tubercle spines. The present study demonstrated that C. cerastes venom exerts potential in vitro antischistosomal activity in a time and dose-dependent manner. These results may warrant further investigations to develop novel schistosomicidal agents from C. cerastes snake venom.

 Grunting for worms: reactions of Diplocardia to seismic vibrations

Treesearch

M.A. Callaham

2009-01-01

Harvesting earthworms by a practice called 'worm grunting' is a widespread and profitable business in the southeastern USA. Although a variety of techniques are used, most involve rhythmically scraping a wooden stake driven into the ground, with a fiat metal object. A common assumption is that vibrations cause the worms to surface, but this phenomenon has not...

Caenorhabditis elegans utilizes dauer pheromone biosynthesis to dispose of toxic peroxisomal fatty acids for cellular homoeostasis

USDA-ARS?s Scientific Manuscript database

Caenorhabditis elegans secretes a dauer pheromone or daumone composed of ascarylose and a fatty acid side chain, perception of which enables worms to gauge depletion of food or a high worm population density. As a result, worms enter the dauer state, a specific developmental stage capable of surviv...

Worms in the College Classroom: More than Just a Composting Demonstration

ERIC Educational Resources Information Center

Kelley, Rebecca L.

2010-01-01

Although worm bins have been used by K-12 and nonformal educators for decades, there is little evidence of their use in postsecondary education. The ease of use, maintenance, affordability, portability, and diversity of scientific concepts that can be demonstrated with a worm bin make it a valuable tool in college science classrooms. The purpose…

Photodynamic inactivation using curcuminoids and Photogem on caenorhabditis elegans

NASA Astrophysics Data System (ADS)

Albuquerque, Yulli R.; Pratavieira, Sebastião.; Bagnato, Vanderlei S.; Inada, Natalia M.; Souza, Larissa M.; Afonso, Ana; de Souza, Clovis W. O.; Oliveira, Kleber T.; Anibal, Fernanda F.

2018-02-01

Resistance to various anthelmintic drugs is reported in many animals and can become a severe problem for human and animal health. In this study, Photogem® and three curcuminoids compounds (curcumin, demethoxycurcumin, bisdemethoxycurcumin) were used as photosensitizers in the photodynamic inactivation (PDI) in the helminth model Caenorhabditis elegans to investigate the ability of this procedure to worm life cycle. Initially, the presence and location of the photosensitizers in the worm's body were verified by fluorescence confocal microscopy. Curcumin was deposited in the digestive tract and Photogem® along the body of the animal in the incubation time of 12 hours with the photosensitizer. Subsequently, a PDI procedure using a LED device was performed to illuminate the worms treated with the photosensitizers. The worms were observed by optical microscopy until 48 hours after the PDI to verify the changes in motility, the presence of eggs and larvae and the number of live worms. Curcuminoids tested separately and in combination and two light doses of 30 J/m2 no changes were observed in the life cycle of the worm at concentrations of 2 mM and 1 mM. However, in treatment with Photogem® and a light dose of 100 J/m2 a reduction in motility and reproduction of the worm with 0.2 mg/mL was observed after 6 hours of exposure, in addition to the death of most worms at concentrations of 6, 4, and 2 mg/mL. We suggest, therefore, that photodynamic inactivation with Photogem® may present an anthelmintic effect against C. elegans, but there is a need for studies on helminths with parasitic activity.

Genetic analysis of Trichuris suis and Trichuris trichiura recovered from humans and pigs in a sympatric setting in Uganda.

PubMed

Nissen, Sofie; Al-Jubury, Azmi; Hansen, Tina V A; Olsen, Annette; Christensen, Henrik; Thamsborg, Stig M; Nejsum, Peter

2012-08-13

The whipworms Trichuris trichiura and Trichuris suis in humans and pigs, respectively, are believed to be two different species yet closely related. Morphologically, adult worms, eggs and larvae of the two species are indistinguishable. The aim of this study was to examine the genetic variation of Trichuris sp. mainly recovered from natural infected pigs and humans. Worm material isolated from humans and pigs living in the same geographical region in Uganda were analyzed by PCR, cloning and sequencing. Measurements of morphometric characters were also performed. The analysis of the ITS-2 (internal transcribed spacer) region showed a high genetic variation in the human-derived worms with two sequence types, designated type 1 and type 2, differing with up to 45%, the type 2 being identical to the sequence found in pig-derived worms. A single human-derived worm showed exclusively the type 2-genotype (T. suis-type) and three cases of 'heterozygote' worms in humans were identified. However, the analysis showed that sympatric Trichuris primarily assorted with host origin. Sequence analysis of a part of the genetically conserved β-tubulin gene confirmed two separate populations/species but also showed that the 'heterozygote' worms had a T. suis-like β-tubulin gene. A PCR-RFLP on the ITS-2 region was developed, that could distinguish between worms of the pig, human and 'heterozygote' type. The data suggest that Trichuris in pigs and humans belong to two different populations (i.e. are two different species). However, the data presented also suggest that cross-infections of humans with T. suis takes place. Further studies on sympatric Trichuris populations are highly warranted in order to explore transmission dynamics and unravel the zoonotic potential of T. suis. Copyright © 2012 Elsevier B.V. All rights reserved.

[Efficacy evaluation of epsiprantel (Cestex) against Echinococcus mutilocularis in dogs and cats].

PubMed

Eckert, J; Thompson, R C; Bucklar, H; Bilger, B; Deplazes, P

2001-01-01

Helminth-free dogs and cats were experimentally infected with protoscoleces of Echinococcus multilocularis and used in controlled trials for efficacy evaluation of the cestodicide epsiprantel. In two separate trials each 4 dogs were treated at day 20 post infection (p.i.) with average oral dosages of 5.1 (4.9-5.3) and 5.4 (5.2-5.8) mg/kg body weight (b.w.) epsiprantel, respectively, and necropsied at day 24 p.i. Among each 4 dogs of the two untreated control groups all animals were infected and had high intestinal worm burdens with averages of 33.575 and 100.725 E. multilocularis specimens per animal (individual worm burdens in group Ib 59,500-149,800, group IIb 20,500-43,200); in the two groups of treated dogs the average worm burdens were reduced by 99.6 and 99.9%. Among 8 treated dogs 4 were helminth-free, the other 4 had residual worm burdens (10-70 in 3 dogs, 1480 in 1 dog). In each 5 cats single oral treatments with average doses of 2.7 (2.7-2.8) and 5.5 (5.5-5.5) mg/kg b.w. epsiprantel were 100% effective against E. multilocularis 20 days p.i. and eliminated the worm burdens from all 10 animals. In the untreated group of 5 cats the average worm burden was 2864 per animal (individual worm burdens 20-6830). Side effects of the drug treatment were not observed. The results of the study show that in single therapeutic dosages recommended by the producer (dogs 5.5 mg, cats 2.75 mg/kg b.w.) epsiprantel eliminates E. multilocularis to over 99% or completely, but residual worm burdens may persist in some animals.

Impacts of chipping on surrogates for the longhorned beetle Anoplophora glabripennis (Coleoptera: Cerambycidae) in logs.

PubMed

Wang, B; Mastro, V C; McLane, W H

2000-12-01

As part of the eradication program for recent introductions of the longhorned beetle Anoplophora glabripennis (Motschulsky) in the United States, wood from infested trees is chipped and incinerated. Two tests were conducted to evaluate the efficiency of chipping wood from infested trees on the survival of the beetle. In the first test, plastic worms were used as surrogates for larvae of the beetle. Plastic worms of different sizes were placed in holes drilled in logs of sugar maple, Acer saccharum Marsh. In a second test, in addition to plastic worms, we used different instars and pupae of gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae); larvae of the beetle Phyllophaga annina Lewis (Coleoptera: Scarabaeidae); and larvae of an unidentified weevil (Coleoptera: Curculionidae). Although chipping did not result in an obvious damage to all plastic worms, it did kill all larvae and pupae of insects placed in holes of maple logs. The overall recovery rate (percent recovered) for the plastic worms was 96% in the first (1997) test, and 71 and 98% for 10 and 40 mm long plastic worms in the second (1998) test, respectively. Logistic regression analysis of the data from the first experiment indicates that larger worms receive more severe damage. Size of logs did not have a significant effect on the level of damage received by plastic worms. All recovered insects were severely damaged after chipping logs and we could not determine recovery rates. Results of the two tests indicate that chipping wood from infested trees without incineration of the resulting chips provides a highly effective method for destroying wood inhabiting insect pests such as A. glabripennis. The elimination of incineration saves considerable resources while effectively eliminating risks associated with movements of wood containing living wood-boring insects.

Operation of an aquatic worm reactor suitable for sludge reduction at large scale.

PubMed

Hendrickx, Tim L G; Elissen, Hellen H J; Temmink, Hardy; Buisman, Cees J N

2011-10-15

Treatment of domestic waste water results in the production of waste sludge, which requires costly further processing. A biological method to reduce the amount of waste sludge and its volume is treatment in an aquatic worm reactor. The potential of such a worm reactor with the oligochaete Lumbriculus variegatus has been shown at small scale. For scaling up purposes, a new configuration of the reactor was designed, in which the worms were positioned horizontally in the carrier material. This was tested in a continuous experiment of 8 weeks where it treated all the waste sludge from a lab-scale activated sludge process. The results showed a higher worm growth rate compared to previous experiments with the old configuration, whilst nutrient release was similar. The new configuration has a low footprint and allows for easy aeration and faeces collection, thereby making it suitable for full scale application. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dietary and microbiome factors determine longevity in Caenorhabditis elegans

PubMed Central

Sánchez-Blanco, Adolfo; Rodríguez-Matellán, Alberto; González-Paramás, Ana; González-Manzano, Susana; Kim, Stuart K.; Mollinedo, Faustino

2016-01-01

Diet composition affects organismal health. Nutrient uptake depends on the microbiome. Caenorhabditis elegans fed a Bacillus subtilis diet live longer than those fed the standard Escherichia coli diet. Here we report that this longevity difference is primarily caused by dietary coQ, an antioxidant synthesized by E. coli but not by B. subtilis. CoQ-supplemented E. coli fed worms have a lower oxidation state yet live shorter than coQ-less B. subtilis fed worms. We showed that mutations affecting longevity for E. coli fed worms do not always lead to similar effects when worms are fed B. subtilis. We propose that coQ supplementation by the E. coli diet alters the worm cellular REDOX homeostasis, thus decreasing longevity. Our results highlight the importance of microbiome factors in longevity, argue that antioxidant supplementation can be detrimental, and suggest that the C. elegans standard E. coli diet can alter the effect of signaling pathways on longevity. PMID:27510225

Face Gear Drive with Spur Involute Pinion: Geometry, Generation by a Worm, Stress Analysis

NASA Technical Reports Server (NTRS)

Litvin, Faydor L.; Fuentes, Alfonso; Zanzi, Claudio; Pontiggia, Matteo; Handschuh, Robert F. (Technical Monitor)

2002-01-01

A face gear drive with a spur involute pinion is considered. The generation of the face gear is based on application of a grinding or cutting worm whereas the conventional method of generation is based on application of an involute shaper. An analytical approach is proposed for the determination of: (1) the worm thread surface; (2) avoidance of singularities of the worm thread surface, (air) dressing of the worm; and (3) determination of stresses of the face-gear drive. A computer program for simulation of meshing and contact of the pinion and face-gear has been developed. Correction of machine-tool settings is proposed for reduction of the shift of the bearing contact caused by misalignment. An automatic development of the model of five contacting teeth has been proposed for stress analysis. Numerical examples for illustration of the developed theory are provided.

Removal of Thelazia callipaeda from the subconjunctival space.

PubMed

Yagi, T; Sasoh, M; Kawano, T; Ito, K; Uji, Y; Ando, K

2007-01-01

To report the finding of Thelazia callipaeda within the human subconjunctival space. An 81-year-old man with a history of traumatic conjunctival laceration that occurred 2 years previously had white worms in the subconjunctival space of his right eye. Five worms were removed from the subconjunctival space via a local peritomy, since there was no conjunctival laceration noted during the examination. These worms were identified as T callipaeda. T callipaeda cannot dig holes in the ocular wall due to the lack of hooks or sharp spines within the mouth. Therefore, the authors speculate that these worms entered the subconjunctival space through a conjunctival laceration that had occurred 2 years previously.

Orthotic arm joint. [for use in mechanical arms

NASA Technical Reports Server (NTRS)

Dane, D. H. (Inventor)

1974-01-01

An improved orthopedic (orthotic) arm joint that can be used in various joint of mechanical arms is described. The arm joints includes a worm, which is coupled to an electric motor for rotating a worm gear carried within a rotatable housing. The worm gear is supported on a thrust bearing and the rotatable housing is supported on a radial thrust bearing. A bolt extends through the housing, bearings, and worm gear for securing the device together. A potentiometer extends through the bolt, and is coupled to the rotatable housing for rotating therewith, so as to produce an electrical signal indicating the angular position of the rotatable housing.

Dracunculiasis (guinea worm disease).

PubMed

Greenaway, Chris

2004-02-17

Dracunculiasis (guinea worm disease) is a parasitic disease that is limited to remote, rural villages in 13 sub-Saharan African countries that do not have access to safe drinking water. It is one the next diseases targeted for eradication by the World Health Organization. Guinea worm disease is transmitted by drinking water containing copepods (water fleas) that are infected with Dracunculiasis medinensis larvae. One year after human ingestion of infected water a female adult worm emerges, typically from a lower extremity, producing painful ulcers that can impair mobility for up to several weeks. This disease occurs annually when agricultural activities are at their peak. Large proportions of economically productive individuals of a village are usually affected simultaneously, resulting in decreased agricultural productivity and economic hardship. Eradication of guinea worm disease depends on prevention, as there is no effective treatment or vaccine. Since 1986, there has been a 98% reduction in guinea worm disease worldwide, achieved primarily through community-based programs. These programs have educated local populations on how to filter drinking water to remove the parasite and how to prevent those with ulcers from infecting drinking-water sources. Complete eradication will require sustained high-level political, financial and community support.

Guinea worm infection in northern Nigeria: reflections on a disease approaching eradication.

PubMed

Greenwood, Brian; Greenwood, Alice; Bradley, Andrew

2017-05-01

Global eradication of the guinea worm (Dracunculus medinensis) is near, although perhaps delayed a little by the discovery of a transmission cycle in dogs. It is therefore an appropriate time to reflect on the severe impact of this infection on the life of the communities where it was endemic prior to the start of the global eradication programme in 1981. From 1971 to 1974, we conducted a series of unpublished studies on guinea worm in a group of villages in Katsina State, northern Nigeria, where the infection was highly endemic. These studies demonstrated the high rate of infection in affected communities, the frequent recurrence of the infection in some subjects and the long-standing disability that remained in some infected individuals. Immunological studies showed a high level of immediate hypersensitivity to adult worm and larval antigens but a downregulation of Th1-type T-cell responses to worm antigens. Freeing communities such as those described in this article from the scourge of guinea worm infection for good will be an important public health triumph. © 2017 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

Is Gnathostoma turgidum an annual parasite of opossums? Drastic seasonal changes of infection in Didelphis virginiana in Mexico.

PubMed

Nawa, Yukifumi; de la Cruz-Otero, María del Carmen; Zazueta-Ramos, Magda Luz; Bojórquez-Contreras, Angel; Sicairos-Félix, Josefina; Campista-León, Samuel; Torres-Montoya, Edith Hilario; Sánchez-Gonzalest, Sergio; Guzmán-Loreto, Roberto; Delgado-Vargas, Francisco; Díaz-Camacho, Sylvia Páz

2009-08-01

Gnathostoma turgidum is a nematode that parasitizes the stomach of opossums, Didelphis virginiana. Despite its wide distribution in the Americas, its natural life cycle is poorly understood. Recently, we found an endemic area for G. turgidum infection in Sinaloa, Mexico (Diaz-Camacho et al., 2009). Based on sporadic surveys for several years, the prevalence was apparently high in summer and extremely low in winter. To confirm that this is really a seasonal variance, we conducted a longitudinal survey on G. turgidum infection in opossums from November 2007 to November 2008. The results showed amazing seasonal changes in the prevalence, with synchronized migration and maturation of worms in opossums. Between February and March, many juvenile worms, with occasional AL3, were found in the liver, but no worms were found in the stomach. Mature adult worms began to appear in the stomach around April and rapidly increased in number toward July, when all worms resided in the stomach. Then, the worms disappeared almost completely by November. These results suggest that G. turgidum is an annual parasite of the opossum, D. virginiana, in Mexico.

In vitro schistosomicidal effects of aqueous and dichloromethane fractions from leaves and stems of Piper species and the isolation of an active amide from P. amalago L. (Piperaceae).

PubMed

Carrara, V S; Vieira, S C H; de Paula, R G; Rodrigues, V; Magalhães, L G; Cortez, D A G; Da Silva Filho, A A

2014-09-01

Dichloromethane and aqueous fractions from leaves and stems of Piper arboreum Aubl., P. aduncum L., P. amalago L., P. crassinervium H.B. & K., P. diospyrifolium Kunth, P. hispidum Sw. and P. xylosteoides (Kunth) Steud. were tested against adult worms of Schistosoma mansoni. The in vitro activity was evaluated in terms of mortality, number of separated worms and number of worms with reduced motor activity. Most dichloromethane fractions from all Piper species showed moderate schistosomicidal activity, but aqueous fractions were not active. The dichloromethane fraction of P. amalago leaves (at 100 μg/ml) showed the highest activity, resulting in worm mortality, the separation of worm pairs and reduced motor activity. Chromatographic fractionation of the dichloromethane fraction of P. amalago leaves led to the isolation of its major compound, which was also tested against adults of S. mansoni. The isolated piperamide N-[7-(3',4'-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl] pyrrolidine, at 100 μ m, resulted in the mortality of all adult worms after 24 h of incubation. The findings suggest that species of Piper are potential sources of schistosomicidal compounds.

Associations among habitat characteristics and meningeal worm prevalence in eastern South Dakota, USA

USGS Publications Warehouse

Jacques, Christopher N.; Jenks, Jonathan A.; Klaver, Robert W.; Dubay, Shelli A.

2017-01-01

Few studies have evaluated how wetland and forest characteristics influence the prevalence of meningeal worm (Parelaphostrongylus tenuis) infection of deer throughout the grassland biome of central North America. We used previously collected, county-level prevalence data to evaluate associations between habitat characteristics and probability of meningeal worm infection in white-tailed deer (Odocoileus virginianus) across eastern South Dakota, US. The highest-ranked binomial regression model for detecting probability of meningeal worm infection was spring temperature + summer precipitation + percent wetland; weight of evidence (wi=0.71) favored this model over alternative models, though predictive capability was low (Receiver operating characteristic=0.62). Probability of meningeal worm infection increased by 1.3- and 1.6-fold for each 1-cm and 1-C increase in summer precipitation and spring temperature, respectively. Similarly, probability of infection increased 1.2-fold for each 1% increase in wetland habitat. Our findings highlight the importance of wetland habitat in predicting meningeal worm infection across eastern South Dakota. Future research is warranted to evaluate the relationships between climatic conditions (e.g., drought, wet cycles) and deer habitat selection in maintaining P. tenuis along the western boundary of the parasite.

Petri Net and Probabilistic Model Checking Based Approach for the Modelling, Simulation and Verification of Internet Worm Propagation

PubMed Central

Razzaq, Misbah; Ahmad, Jamil

2015-01-01

Internet worms are analogous to biological viruses since they can infect a host and have the ability to propagate through a chosen medium. To prevent the spread of a worm or to grasp how to regulate a prevailing worm, compartmental models are commonly used as a means to examine and understand the patterns and mechanisms of a worm spread. However, one of the greatest challenge is to produce methods to verify and validate the behavioural properties of a compartmental model. This is why in this study we suggest a framework based on Petri Nets and Model Checking through which we can meticulously examine and validate these models. We investigate Susceptible-Exposed-Infectious-Recovered (SEIR) model and propose a new model Susceptible-Exposed-Infectious-Recovered-Delayed-Quarantined (Susceptible/Recovered) (SEIDQR(S/I)) along with hybrid quarantine strategy, which is then constructed and analysed using Stochastic Petri Nets and Continuous Time Markov Chain. The analysis shows that the hybrid quarantine strategy is extremely effective in reducing the risk of propagating the worm. Through Model Checking, we gained insight into the functionality of compartmental models. Model Checking results validate simulation ones well, which fully support the proposed framework. PMID:26713449

Petri Net and Probabilistic Model Checking Based Approach for the Modelling, Simulation and Verification of Internet Worm Propagation.

PubMed

Razzaq, Misbah; Ahmad, Jamil

2015-01-01

Internet worms are analogous to biological viruses since they can infect a host and have the ability to propagate through a chosen medium. To prevent the spread of a worm or to grasp how to regulate a prevailing worm, compartmental models are commonly used as a means to examine and understand the patterns and mechanisms of a worm spread. However, one of the greatest challenge is to produce methods to verify and validate the behavioural properties of a compartmental model. This is why in this study we suggest a framework based on Petri Nets and Model Checking through which we can meticulously examine and validate these models. We investigate Susceptible-Exposed-Infectious-Recovered (SEIR) model and propose a new model Susceptible-Exposed-Infectious-Recovered-Delayed-Quarantined (Susceptible/Recovered) (SEIDQR(S/I)) along with hybrid quarantine strategy, which is then constructed and analysed using Stochastic Petri Nets and Continuous Time Markov Chain. The analysis shows that the hybrid quarantine strategy is extremely effective in reducing the risk of propagating the worm. Through Model Checking, we gained insight into the functionality of compartmental models. Model Checking results validate simulation ones well, which fully support the proposed framework.

Inference of pain stimulus level from stereotypical behavioral response of C.elegans allows quantification of effects of anesthesia and mutation

NASA Astrophysics Data System (ADS)

Leung, Kawai; Mohammadi, Aylia; Ryu, William; Nemenman, Ilya

In animals, we must infer the pain level from experimental characterization of behavior. This is not trivial since behaviors are very complex and multidimensional. To establish C.elegans as a model for pain research, we propose for the first time a quantitative model that allows inference of a thermal nociceptive stimulus level from the behavior of an individual worm. We apply controlled levels of pain by locally heating worms with an infrared laser and capturing the subsequent behavior. We discover that the behavioral response is a product of stereotypical behavior and a nonlinear function of the strength of stimulus. The same stereotypical behavior is observed in normal, anesthetized and mutated worms. From this result we build a Bayesian model to infer the strength of laser stimulus from the behavior. This model allows us to measure the efficacy of anaesthetization and mutation by comparing the inferred strength of stimulus. Based on the measured nociceptive escape of over 200 worms, our model is able to significantly differentiate normal, anaesthetized and mutated worms with 40 worm samples. This work was partially supported by NSF Grant No. IOS/1208126 and HFSP Grant No. RGY0084/.

Worm Disease Profile of Primary School Children

NASA Astrophysics Data System (ADS)

Hartati; Destriani; Victoria, A. R.

2018-01-01

The result of an elementary study of relations between disease symptoms and signs with the wormy occurrence child at Elementary School in Ilir Barat II Subdistrict of Palembang in concerned in this research amount to 200 people from the population of 4200 people of a child in elementary school. The result indicates that the child roommates infested worm marked with a few symptoms like passion eat to Decrease the puking pain in the home of stomach after eating, diarrhea, defecate with the mucus and bleed the purities at the anus before controlled from some worm type of there no difference having a meaning between child roommates worm infested with the child roommates do not infest worm (P > 0.05). Symptom vomit got more amount by having a meaning a child by infested is Trichuris (RO > 2.669, P < 0/005). The result of infested Tricuris generate the more amount of symptoms lust to eat to Decrease by having a meaning of Compared to the which do not infest Trichuris (RO = 3.772; CI 95% = 1.214 to 11.726; P = 0.016) symptoms lust to eat to Decrease and more amount diarrhea got at Infest oxyuris with the special sign of purities at nighttime anus (RO = 0.557; 85% CI = 0.166 to 2.168). The risk of the happening of unfavorable nutrition According to BB / U and Also TB / U growing niche to more amount (having a meaning) at child roommates worm infested by a child Compared to the which do not infest worm.

The effects of Myxobolus cerebralis, myxospore dose on triactinomyxon production and biology of Tubifex tubifex from two geographic regions

USGS Publications Warehouse

Stevens, Richard; Kerans, B.L.; Lemmon, J. C.; Rasmussen, Charlotte

2001-01-01

The aquatic oligochaete Tubifex tubifex is an obligate host of Myxobolus cerebralis, the causative agent of salmonid whirling disease. Tubifex tubifex can become infected by ingesting myxospores ofM. cerebralis that have been released into sediments upon death and decomposition of infected salmonids. Infected worms release triactinomyxons into the water column that then infect salmonids. How the dose of myxospores ingested by T. tubifex influences parasite proliferation and the worm host are not well understood. Using replicated laboratory experiments, we examined how differing doses of myxospores (50, 500, 1,000 per worm) influenced triactinomyxon production and biomass, abundance, and individual weight of 2 geographically distinct populations of T. tubifex. Worm populations produced differing numbers of triactinomyxons, but, within a population, the production did not differ among myxospore doses. At the lowest myxospore dose, 1 worm population produced 45 times more triactinomyxons than myxospores received, whereas the other produced only 6 times more triactinomyxons than myxospores. Moreover, total T. tubifex biomass, abundance, and individual weight were lower among worms receiving myxospores than in myxospore-free controls. Thus, T. tubifex populations differ in ability to support the replication of M. cerebralis, and infection has measurable consequences on fitness of the worm host. These results suggest that variability in whirling disease severity observed in wild salmonid populations may partially be attributed to differences in T. tubifex populations.

Identification of animal behavioral strategies by inverse reinforcement learning.

PubMed

Yamaguchi, Shoichiro; Naoki, Honda; Ikeda, Muneki; Tsukada, Yuki; Nakano, Shunji; Mori, Ikue; Ishii, Shin

2018-05-01

Animals are able to reach a desired state in an environment by controlling various behavioral patterns. Identification of the behavioral strategy used for this control is important for understanding animals' decision-making and is fundamental to dissect information processing done by the nervous system. However, methods for quantifying such behavioral strategies have not been fully established. In this study, we developed an inverse reinforcement-learning (IRL) framework to identify an animal's behavioral strategy from behavioral time-series data. We applied this framework to C. elegans thermotactic behavior; after cultivation at a constant temperature with or without food, fed worms prefer, while starved worms avoid the cultivation temperature on a thermal gradient. Our IRL approach revealed that the fed worms used both the absolute temperature and its temporal derivative and that their behavior involved two strategies: directed migration (DM) and isothermal migration (IM). With DM, worms efficiently reached specific temperatures, which explains their thermotactic behavior when fed. With IM, worms moved along a constant temperature, which reflects isothermal tracking, well-observed in previous studies. In contrast to fed animals, starved worms escaped the cultivation temperature using only the absolute, but not the temporal derivative of temperature. We also investigated the neural basis underlying these strategies, by applying our method to thermosensory neuron-deficient worms. Thus, our IRL-based approach is useful in identifying animal strategies from behavioral time-series data and could be applied to a wide range of behavioral studies, including decision-making, in other organisms.

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 ...

Role of CREB in CML

DTIC Science & Technology

2007-02-01

antisense RNA for suppressing gene expression in nematode worms (Caenorhabditis elegans) 2. This was followed by the introduction of dsRNA into worms...When single-stranded antisense RNA and double stranded RNA was introduced into worms, they found that dsRNA was more effective than either strand...RISC ( RNA -induced silencing complex), which contains helicase activity that unwinds the two strands 3 of RNA molecules, allowing the antisense

Worms Eat My Garbage. How To Set Up and Maintain a Worm Composting System. First Edition.

ERIC Educational Resources Information Center

Appelhof, Mary

This book is a resource for parents and teachers who want to teach about recycling and composting by setting up and maintaining a worm composting system. It is designed to be a detailed yet simple manual of vermicomposting. The manual covers the basics of vermicomposting and answers such questions as where to store a composting container, what…

Effects of simulated microgravity on gene expression and biological phenotypes of a single generation Caenorhabditis elegans cultured on 2 different media

NASA Astrophysics Data System (ADS)

Tee, Ling Fei; Neoh, Hui-min; Then, Sue Mian; Murad, Nor Azian; Asillam, Mohd Fairos; Hashim, Mohd Helmy; Nathan, Sheila; Jamal, Rahman

2017-11-01

Studies of multigenerational Caenorhabditis elegans exposed to long-term spaceflight have revealed expression changes of genes involved in longevity, DNA repair, and locomotion. However, results from spaceflight experiments are difficult to reproduce as space missions are costly and opportunities are rather limited for researchers. In addition, multigenerational cultures of C. elegans used in previous studies contribute to mixture of gene expression profiles from both larvae and adult worms, which were recently reported to be different. Usage of different culture media during microgravity simulation experiments might also give rise to differences in the gene expression and biological phenotypes of the worms. In this study, we investigated the effects of simulated microgravity on the gene expression and biological phenotype profiles of a single generation of C. elegans worms cultured on 2 different culture media. A desktop Random Positioning Machine (RPM) was used to simulate microgravity on the worms for approximately 52 to 54 h. Gene expression profile was analysed using the Affymetrix GeneChip® C. elegans 1.0 ST Array. Only one gene (R01H2.2) was found to be downregulated in nematode growth medium (NGM)-cultured worms exposed to simulated microgravity. On the other hand, eight genes were differentially expressed for C. elegans Maintenance Medium (CeMM)-cultured worms in microgravity; six were upregulated, while two were downregulated. Five of the upregulated genes (C07E3.15, C34H3.21, C32D5.16, F35H8.9 and C34F11.17) encode non-coding RNAs. In terms of biological phenotype, we observed that microgravity-simulated worms experienced minimal changes in terms of lifespan, locomotion and reproductive capabilities in comparison with the ground controls. Taking it all together, simulated microgravity on a single generation of C. elegans did not confer major changes to their gene expression and biological phenotype. Nevertheless, exposure of the worms to microgravity lead to higher expression of non-coding RNA genes, which may play an epigenetic role in the worms during longer terms of microgravity exposure.

Blood flukes Cardicola parvus and C. laruei (Trematoda: Aporocotylidae): life cycles and cryptic infection in spotted seatrout, Cynoscion nebulosus (Teleost: Sciaenidae).

PubMed

Siegel, Sasha V; Rivero, Andrea V; Oberstaller, Jenna; Colon, Beatrice L; de Buron, Isaure; Kyle, Dennis E

2018-04-01

Aporocotylidae comprises a diverse family of fish blood flukes, with adults found in blood or body cavity of marine, brackish, or freshwater fish. Aporocotylids are unique among the Digenea with many developing in polychaetes. The life cycle has been elucidated for only a few species that develop in polychaetes from marine/brackish environments and none for western Atlantic aporocotylids. The basis for this study was observations of blood fluke larvae in annelids from South Carolina, USA in 1982 prior to possible usage of molecular tools to specifically identify parasite larvae. Recent description of aporocotylid species and genotyping tools prompted revisiting original collection sites to examine polychaetes and fish as potential hosts. Polycirrid Enoplobranchus sanguineus and terebellids Amphitrite ornata, and Terebella lapidaria revealed infections with aporocotylid larvae. Adult blood flukes were also collected from fish commonly encountered in the same habitat: spotted seatrout (Cynoscion nebulosus), red drum (Sciaenops ocellatus), black drum (Pogonias cromis), and Atlantic croaker (Micropogonias undulatus). Sporocysts containing cercariae were found in individuals of each annelid species. Adult Cardicola parvus were found in spotted seatrout and Atlantic croaker, C. laruei in spotted seatrout, C. currani in red drum, and C. palmeri in black drum. Genotype analysis of ITS-2 and lsrDNA of all forms confirmed conspecific infections by C. parvus in E. sanguineus and A. ornata and C. laruei in T. lapidaria. This is the first description of complete life cycles of aporocotylids in the Western Atlantic and first evidence of cryptic infections of Cy. nebulosus with C. parvus. Copyright © 2017 Elsevier B.V. All rights reserved.

Estuarine resources use by juvenile Flagfin mojarra ( Eucinostomus melanopterus) in an inverse tropical estuary (Sine Saloum, Senegal)

NASA Astrophysics Data System (ADS)

Gning, Ndombour; Le Loc'h, François; Thiaw, Omar T.; Aliaume, Catherine; Vidy, Guy

2010-03-01

The Flagfin mojarra, Eucinostomus melanopterus, is a marine spawner whose young individuals are common in the Sine Saloum inverse estuary (Senegal). The species offers the opportunity to study both the use of the estuarine nursery resources and the impact of the particular environment of the inverse estuary on these resources. This will lead to a better understanding of the functioning of the nursery. We investigated the resources used by juvenile Flagfin mojarra by coupling stomach contents and stable isotopes methods. Young Flagfin mojarra feed on a wide range of invertebrates. Diet changed from copepods in the smallest size class (10-40 mm), to a range of invertebrates including amphipods, insect larvae, polychaetes and mollusc in the medium size class (up to 60 mm) and mainly polychaetes for individuals >60 mm in size. In mangrove habitats with moderate salinity, the diet was dominated by polychaetes and decapod larvae (crabs) whereas in habitats with higher salinity, diet was dominated by amphipods. In very hypersaline areas with scarce mangroves, diet comprised benthic copepods, chironomid larvae and ostracods. This agreed with a clear change in δ13C measured in fish sampled at downstream or upstream sites. Comparison with signatures of primary producers suggested that the local food web exploited by young Flagfin mojarra is mainly based on phytoplankton in the downstream mangrove area, and mainly on benthic microalgae in the upstream hypersaline area. As in many studies considering the food webs in mangrove, mangrove was not identified as a major contributor to the food web exploited by E. melanopterus. This needs further investigation particularly because the exportation of estuarine materials to the sea is limited in an inverse estuary.

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.

Biodiversity and distribution of polynoid and spionid polychaetes (Annelida) in the Vema Fracture Zone, tropical North Atlantic

NASA Astrophysics Data System (ADS)

Guggolz, Theresa; Lins, Lidia; Meißner, Karin; Brandt, Angelika

2018-02-01

During the Vema-TRANSIT (Bathymetry of the Vema-Fracture Zone and Puerto Rico TRench and Abyssal AtlaNtic BiodiverSITy Study) expedition from December, 2014 to January, 2015, a transect along the Vema Fracture Zone in the equatorial Atlantic was surveyed and sampled at about 10°N. The Vema Fracture Zone is one of the largest fracture zones of the Mid-Atlantic Ridge and it is characterized by a large left-lateral offset. Benthic communities of the transect and the abyssal basins on both sides were investigated to examine whether the Mid-Atlantic Ridge serves as a physical barrier for these organisms, or if there is a potential connection from east to west via the Vema Fracture Zone. Samples comprised 4149 polychaetes, belonging to 42 families. Exemplary, Polynoidae and Spionidae, both typical deep-sea families with high abundances in all investigated regions, were identified up to species level. The present results show significant differences in polychaete faunistic composition between both sides of the Mid-Atlantic Ridge. Moreover, the eastern and western Vema Fracture Zone characterizes divergent habitats, since the two basins differ in sedimentology and environmental variables (e.g. temperature, salinity), hence characterizing divergent habitats. Most species found were restricted to either eastern or western VFZ, but there was a trans-Mid-Atlantic Ridge distribution of certain abundant species observed, indicating that the Mid-Atlantic Ridge might rather act limiting to dispersal between ocean basins than as an absolute barrier. Given the abyssal valley formed by the Vema Fracture Zone and its role in oceanic currents, this seafloor feature may well represent exchange routes between eastern and western faunas.

Morphological distinction between estuarine polychaetes: Laeonereis culveri and L. nota (Phyllodocida: Nereididae).

PubMed

de Jesus-Flores, Citlalli; Salazar-González, S Alejandro; Salazar-Vallejo, Sergio I

2016-03-01

The family Nereididae includes more than 500 polychaete species described worldwide, and includes species common in many benthic environments, but some other species may tolerate freshwater or can even thrive in humid substrates in tropical forests. In estuarine environments, nereidid polychaetes can be abundant and relevant as a food source for resident or migratory birds. Laeonereis culveri (Webster, 1879) is a common estuarine species found in tropical and subtropical Atlantic American shores and was described from New Jersey; its median and posterior parapodia have upper notopodial ligules usually longer than the lower ones, and the latter are parallel to the notaciculae throughout the body. L. culveri distribution is from Connecticut to central Argentina; however, this wide distribution might be due to the inclusion of several other species as junior synonyms, despite that some morphological differences were found between them. One of such species is L. nota (Treadwell, 1941), that was described from Texas; its parapodia have notopodial ligules of about the same size, and the lower ones are oblique to the notaciculae. In order to clarify the differences between these two species, and to define which inhabits the Northwestern Caribbean region, topotype materials from these two species and specimens from Chetumal Bay were collected, and their morphological features were compared. Our results indicated that L. culveri and L. nota are different species and that the latter is found in Chetumal Bay. On the basis of mature specimens, L. culveri is hereby restricted to the Northern Gulf of Mexico and Northwestern Atlantic Ocean, and L. nota are reinstated and its distribution extends from Texas, in the Gulf of Mexico to Chetumal Bay, in the Northwestern Caribbean Sea. A key to identify all species in Laeonereis Hartman (1945) is also included.

Examination of the relationship between host worm community structure on transmission of the parasite, Myxobolus cerebralis by developing taxon-specific probes for multiplex qPCR to identify worm taxa in stream communities

NASA Astrophysics Data System (ADS)

Fytilis, N.; Lamb, R.; Kerans, B.; Stevens, L.; Rizzo, D. M.

2011-12-01

Fish diseases are often caused by waterborne parasites, making them ideal systems for modeling the non-linear relationships between disease dynamics, stream dwelling oligochaete communities and geochemical features. Myxobolus cerebralis, the causative agent of whirling disease in salmonid fishes, has been a major contributor to the loss of wild rainbow trout populations in numerous streams within the Intermountain West. The parasite alternates between an invertebrate and vertebrate host, being transmitted between the sediment feeding worm Tubifex tubifex (T.tubifex) and salmonid fishes. Worm community biodiversity and abundance are influenced by biogeochemical features and have been linked to disease severity in fish. The worm (T.tubifex) lives in communities with 3-4 other types of worms in stream sediments. Unfortunately, taxonomic identification of oligochaetes is largely dependent on morphological characteristics of sexually mature adults. We have collected and identified ~700 worms from eight sites using molecular genetic probes and a taxonomic key. Additionally, ~1700 worms were identified using only molecular genetic probes. To facilitate distinguishing among tubificids, we developed two multiplex molecular genetic probe-based quantitative polymerase reaction (qPCR) assays to assess tubificid communities in the study area. Similar qPCR techniques specific for M.cerebralis used to determine if individual worms were infected with the parasite. We show how simple Bayesian analysis of the qPCR data can predict the worm community structure and reveal relationships between biodiversity of host communities and host-parasite dynamics. To our knowledge, this is the first study that combines molecular data of both the host and the parasite to examine the effects of host community structure on the transmission of a parasite. Our work can be extended to examine the links between worm community structure and biogeochemical features using molecular genetics and Bayesian statistics to assist in identifying new nonlinear relationships and suggest new subsets of input parameters. Future work includes the development of a new complex systems tool capable of assimilating biological DNA sequence data and biogeochemical features using artificial neural networks and Bayesian analysis. The methodologies developed here helped mine the relationships between biodiversity of host communities and host-parasite dynamics. The results from our study will be useful to managers and researchers for assessing the risk of whirling disease in drainages where tubificid community composition data are needed. This collaboration between modelers, field ecologists and geneticists will prove useful in modeling efforts and will enable more effective, high-volume hypothesis generation. The ability to characterize areas of high whirling disease risk is essential for improving our understanding of the dynamics of M.cerebralis such that appropriate management strategies can be implemented.

Marine worms (genus Osedax) colonize cow bones

PubMed Central

Jones, William J; Johnson, Shannon B; Rouse, Greg W; Vrijenhoek, Robert C

2007-01-01

Bone-eating worms of the genus Osedax colonized and grew on cow bones deployed at depths ranging from 385 to 2893 m in Monterey Bay, California. Colonization occurred as rapidly as two months following deployment of the cow bones, similar to the time it takes to colonize exposed whalebones. Some Osedax females found on the cow bones were producing eggs and some hosted dwarf males in their tubes. Morphological and molecular examinations of these worms confirmed the presence of six Osedax species, out of the eight species presently known from Monterey Bay. The ability of Osedax species to colonize, grow and reproduce on cow bones challenges previous notions that these worms are ‘whale-fall specialists.’ PMID:18077256

Marine worms (genus Osedax) colonize cow bones.

PubMed

Jones, William J; Johnson, Shannon B; Rouse, Greg W; Vrijenhoek, Robert C

2008-02-22

Bone-eating worms of the genus Osedax colonized and grew on cow bones deployed at depths ranging from 385 to 2893m in Monterey Bay, California. Colonization occurred as rapidly as two months following deployment of the cow bones, similar to the time it takes to colonize exposed whalebones. Some Osedax females found on the cow bones were producing eggs and some hosted dwarf males in their tubes. Morphological and molecular examinations of these worms confirmed the presence of six Osedax species, out of the eight species presently known from Monterey Bay. The ability of Osedax species to colonize, grow and reproduce on cow bones challenges previous notions that these worms are 'whale-fall specialists.'

Worm-like micelles of CTAB and sodium salicylate under turbulent flow.

PubMed

Rodrigues, Roberta K; da Silva, Marcelo A; Sabadini, Edvaldo

2008-12-16

Polymers with high molecular weight and worm-like micelles are drag-reducing agents under turbulent flow. However, in contrast to the polymeric systems, the worm-like micelles do not undergo mechanical degradation due to the turbulence, because their macromolecular structure can be spontaneously restored. This very favorable property, together with their drag-reduction capability, offer the possibility to use such worm-like micelles in heating and cooling systems to recirculate water while expending less energy. The formation, growth, and stability of worm-like micelles formed by cetyltrimethylammonium bromide (CTAB) and sodium salicylate (NaSal) were investigated using the self-fluorescence of salicylate ions and the ability of the giant micelles to promote hydrodynamic drag reduction under turbulent flow. The turbulence in solutions of CTAB-Sal was produced within the double-gap cell of a rotational rheometer. Detailed diagrams were obtained for different ratios of Sal and CTAB, which revealed transitions associated with the thermal stability of giant micelles under turbulent flow.

Dracunculiasis (guinea worm disease) in the Bume (Nyangaton) people of South Omo, Ethiopia.

PubMed

Jemaneh, L; Taticheff, S

1993-07-01

A village-to-village search for active dracunculiasis cases was carried out in an endemic area of the Bume (Nyangaton) tribe of South Omo Region, Ethiopia. A total of 21 cases, of which 6, 5, and 10 had pre-emergent, emergent and complicated Guinea worm disease, respectively, were identified. Twenty-two worms, ranging from 1-3 per patient, were removed mainly from the lower limbs; worm appearance seems to be associated more with the right limb. Adults between the ages of 20-30 years are highly affected and infection appears to be sex-related as 14/21 (66.7%) of the cases are females. Water procured from water-holes drug in dry river beds provides an ideal situation for the transmission of dracunculiasis amongst the tribesmen. The knowledge, attitudes and perceptions of the Bume people towards the disease and the public health significance of dracunculiasis are discussed in relation to the current goal of the national and global Guinea worm eradication programme.

The Effect of Macrocyclic Lactones-Ivermectin Exposure on Egg Hatching and Larval Development of Caenorhabditis elegans

PubMed Central

Zain, Mariani Mohd; Yahaya, Zary Shariman; Him, Nik Ahmad Irwan Izzauddin Nik

2016-01-01

To date, the ivermectin resistance in nematode parasites has been reported and many studies are carried out to determine the causes of this problem. A free-living Caenorhabditis elegans is used as a model system for this study to investigate the response of C. elegans to ivermectin exposure by using larval development assay. Worms were exposed to ivermectin at concentration from 1 ng/mL to 10 ng/mL and dimethyl sulphoxide (DMSO) as a control. The developments of the worms were monitored for 24, 48, 72, and 96 hours until the worms become adults. Results indicated that worms’ growth began to be affected by ivermectin at a concentration of 5 ng/mL, while at the concentration of 6, 7, 8, 9, and 10 ng/mL, the growth of worms were inhibited compared to control worms. Further study of the protein expression in C. elegans should be done to investigate the up-regulated and down-regulated proteins involve in ivermectin resistance. PMID:27965734

Quantifiers more or less quantify online: ERP evidence for partial incremental interpretation

PubMed Central

Urbach, Thomas P.; Kutas, Marta

2010-01-01

Event-related brain potentials were recorded during RSVP reading to test the hypothesis that quantifier expressions are incrementally interpreted fully and immediately. In sentences tapping general knowledge (Farmers grow crops/worms as their primary source of income), Experiment 1 found larger N400s for atypical (worms) than typical objects (crops). Experiment 2 crossed object typicality with non-logical subject-noun phrase quantifiers (most, few). Off-line plausibility ratings exhibited the crossover interaction predicted by full quantifier interpretation: Most farmers grow crops and Few farmers grow worms were rated more plausible than Most farmers grow worms and Few farmers grow crops. Object N400s, although modulated in the expected direction, did not reverse. Experiment 3 replicated these findings with adverbial quantifiers (Farmers often/rarely grow crops/worms). Interpretation of quantifier expressions thus is neither fully immediate nor fully delayed. Furthermore, object atypicality was associated with a frontal slow positivity in few-type/rarely quantifier contexts, suggesting systematic processing differences among quantifier types. PMID:20640044

Changes in characteristics of soluble microbial products and extracellular polymeric substances in membrane bioreactor coupled with worm reactor: relation to membrane fouling.

PubMed

Tian, Yu; Li, Zhipeng; Lu, Yaobin

2012-10-01

The study focused on the membrane fouling mitigation observed in a membrane bioreactor (MBR) coupled with worm reactor system. During the operation time of 100 days, the transmembrane pressure (TMP) in the combined system was maintained less than 5 kPa, while the final TMP in the Control-MBR increased to 30 kPa. The changes in properties of soluble microbial products (SMP) and extracellular polymeric substances (EPS) after worm predation were investigated by means of various analytical techniques. It was found that due to the worm predation, the reduced amount of EPS was far more than the increased amount of SMP leading to a significant decrease of protein-like substances which were dominant in the membrane foulants. Except for the content decrease, worm predation destroyed the functional groups of simple aromatic proteins and tryptophan protein-like substances in EPS, making them have lower tendency attaching to the membrane in the combined system. Copyright © 2012 Elsevier Ltd. All rights reserved.

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 ...

NATURAL HALOGENATED ORGANIC COMPOUNDS IN MARINE SEDIMENTS ARE FROM POLYCHAETE INDICATOR SPECIES. (R824776)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

HALOGENATED METABOLITES IN TWO MARINE POLYCHAETES AND THEIR PLANKTOTROPHIC AND LECITHOTROPHIC LARVAE. (R824776)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

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.

Ingestion and transfer of microplastics in the planktonic food web.

PubMed

Setälä, Outi; Fleming-Lehtinen, Vivi; Lehtiniemi, Maiju

2014-02-01

Experiments were carried out with different Baltic Sea zooplankton taxa to scan their potential to ingest plastics. Mysid shrimps, copepods, cladocerans, rotifers, polychaete larvae and ciliates were exposed to 10 μm fluorescent polystyrene microspheres. These experiments showed ingestion of microspheres in all taxa studied. The highest percentage of individuals with ingested spheres was found in pelagic polychaete larvae, Marenzelleria spp. Experiments with the copepod Eurytemora affinis and the mysid shrimp Neomysis integer showed egestion of microspheres within 12 h. Food web transfer experiments were done by offering zooplankton labelled with ingested microspheres to mysid shrimps. Microscopy observations of mysid intestine showed the presence of zooplankton prey and microspheres after 3 h incubation. This study shows for the first time the potential of plastic microparticle transfer via planktonic organisms from one trophic level (mesozooplankton) to a higher level (macrozooplankton). The impacts of plastic transfer and possible accumulation in the food web need further investigations. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

PubMed

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

2015-01-01

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.

Bacteria associated with sabellids (Polychaeta: Annelida) as a novel source of surface active compounds.

PubMed

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

2013-05-15

A total of 69 bacteria were isolated from crude oil enrichments of the polychaetes Megalomma claparedei, Sabella spallanzanii and Branchiomma luctuosum, and screened for biosurfactant (BS) production by conventional methods. Potential BS-producers (30 isolates) were primarily selected due to the production of both interesting spots on thin layer chromatography (TLC) plates and highly stable emulsions (E₂₄ ≥ 50%). Only few strains grew on cetyltrimethylammonium bromide and blood agar plates, indicating the probable production of anionic surfactants. The 16S rRNA gene sequencing revealed that selected isolates mainly belonged to the CFB group of Bacteroidetes, followed by Gammaproteobacteria and Alphaproteobacteria. A number of BS-producers belonged to genera (i.e., Cellulophaga, Cobetia, Cohaesibacter, Idiomarina, Pseudovibrio and Thalassospira) that have been never reported as able to produce BSs, even if they have been previously detected in hydrocarbon-enriched samples. Our results suggest that filter-feeding Polychaetes could represent a novel and yet unexplored source of biosurfactant-producing bacteria. Copyright © 2013 Elsevier Ltd. All rights reserved.

Macrobenthic community structure in the northern Saudi waters of the Gulf, 14 years after the 1991 oil spill.

PubMed

Joydas, T V; Qurban, Mohammad A; Al-Suwailem, Abdulaziz; Krishnakumar, P K; Nazeer, Zahid; Cali, N A

2012-02-01

The 1991 Gulf oil spill heavily impacted the coastal areas of the Saudi waters of the Arabian Gulf and recent studies have indicated that even 15 years after the incident, macrobenthos had not completely recovered in the sheltered bays in the affected region such as, Manifa Bay. This study investigates the community conditions of macrobenthos in the open waters in one of the impacted areas, Al-Khafji waters, about 14 years after the spill. Diversity measures and community structure analyses indicate a healthy status of polychaete communities. The BOPA index reveals that oil sensitive amphipods were recolonized in the study area. This confirms that the benthic communities of the oil spill impacted area had taken only <14 years to recover in the open waters of the impacted areas. The study also reveals the existence of three distinct polychaete communities along the depth and sediment gradients. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

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”.

Current state of macrobenthic communities in Baydaratskaya Bay (Kara Sea)

NASA Astrophysics Data System (ADS)

Kokarev, V. N.; Kozlovsky, V. V.; Azovsky, A. I.

2015-09-01

Macrobenthic communities in Baydaratskaya Bay were studied before and after the seafloor pipeline was begun to be laid out in the year 2011. Materials were collected during three surveys in 2007, 2012, and 2013. Ordination of the data based on community structure and composition revealed a clear depthrelated zonality of the communities. Stations deeper than 10 meters were dominated by bivalves, while shallower stations were dominated by nephtyid polychaetes. This structure persisted though the whole period studied, without any pronounced temporal trends. However, several deep-water stations near the pipeline path in the year 2013 revealed a distinct shift in the structure of macrofauna, with large bivalves disappearing, an increased abundance of small polychaetes, and a decrease in total biodiversity. Moreover, macrofauna were absent at one of these stations. We conclude that the structure and distribution of communities are relatively stable and mainly driven by depth. However, there are some local but evident disturbance effects, probably caused by recent human activity (dumping of dredged sediments).

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. Copyright © 2011 Elsevier Ltd. All rights reserved.

Imaging oxygen distribution in marine sediments. The importance of bioturbation and sediment heterogeneity.

PubMed

Pischedda, L; Poggiale, J C; Cuny, P; Gilbert, F

2008-06-01

The influence of sediment oxygen heterogeneity, due to bioturbation, on diffusive oxygen flux was investigated. Laboratory experiments were carried out with 3 macrobenthic species presenting different bioturbation behaviour patterns: the polychaetes Nereis diversicolor and Nereis virens, both constructing ventilated galleries in the sediment column, and the gastropod Cyclope neritea, a burrowing species which does not build any structure. Oxygen two-dimensional distribution in sediments was quantified by means of the optical planar optode technique. Diffusive oxygen fluxes (mean and integrated) and a variability index were calculated on the captured oxygen images. All species increased sediment oxygen heterogeneity compared to the controls without animals. This was particularly noticeable with the polychaetes because of the construction of more or less complex burrows. Integrated diffusive oxygen flux increased with oxygen heterogeneity due to the production of interface available for solute exchanges between overlying water and sediments. This work shows that sediment heterogeneity is an important feature of the control of oxygen exchanges at the sediment-water interface.

Impact of flood events on macrobenthic community structure on an intertidal flat developing in the Ohta River Estuary.

PubMed

Nishijima, Wataru; Nakano, Yoichi; Nakai, Satoshi; Okuda, Tetsuji; Imai, Tsuyoshi; Okada, Mitsumasa

2013-09-15

We investigated the effects of river floods on the macrobenthic community of the intertidal flat in the Ohta River Estuary, Japan, from 2005 to 2010. Sediment erosion by flood events ranged from about 2-3 cm to 12 cm, and the salinity dropped to 0‰ even during low-intensity flood events. Cluster analysis of the macrobenthic population showed that the community structure was controlled by the physical disturbance, decreased salinity, or both. The opportunistic polychaete Capitella sp. was the most dominant species in all clusters, and populations of the long-lived polychaete Ceratonereis erythraeensis increased in years with stable flow and almost disappeared in years with intense flooding. The bivalve Musculista senhousia was also an important opportunistic species that formed mats in summer of the stable years and influenced the structure of the macrobenthic community. Our results demonstrate the substantial effects of flood events on the macrobenthic community structure. Copyright © 2013 Elsevier Ltd. All rights reserved.

Patterns in benthic populations in the Milford Haven waterway following the 'Sea Empress' oil spill with special reference to amphipods.

PubMed

Nikitik, Christopher C S; Robinson, Andrew W

2003-09-01

The macrobenthic fauna of the Milford Haven Waterway was studied in detail following the 'Sea Empress' oil spill in 1996. Contamination patterns indicated heaviest contamination of sediments by oil to have occurred in the lower reaches of the waterway, although water borne hydrocarbons are likely to have penetrated throughout the Haven. Generally, the communities showed little impact of contamination by oil, although some changes were evident at the population level. A decline in the amphipod fauna was observed throughout the Haven, with the genera Ampelisca and Harpinia and the family Isaeidae particularly affected. This was accompanied by increases in both the diversity and abundance of polychaete populations as opportunist species took advantage of the decline of the amphipod fauna. However, within five years of the spill the amphipod fauna has shown clear signs of recovery. The use of the polychaete/amphipod ratio as an indicator of oil pollution is discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Seagrass communities are a major feature of shallow marine areas throughout the world. The marine spermatophyte, Thalassia testudinum Konig, is the dominant seagrass in southeast Florida and the Florida Gulf coast. The trophic interaction between the fishes and the macrobenthic and cryptic fauna found in the area was examined. Based on digestive tract analysis, the principal interaction between the primary consumers of the study area and the higher trophic level predators was via the polychaetes and peracaridean crustaceans. The mollusks which contributed significantly to the benthic biomass were not a preferred food for the animals frequenting the study site. Themore » maximum biomass in any benthic and cryptic samples was 3.35 g dry/m/sup 2/. The majority of the fishes captured were foragers over a wide area. The main residents were the syngnathids and the goldspotted killifish, Floridichthys carpio. It was felt that the predator population was limited by the small stock of polychaetes and peracaridean crustaceans which had a maximum biomass in any one sample equivalent to 1.40 g dry/m/sup 2/.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brook, I.M.

Seagrass communities are a major feature of shallow marine areas throughout the world. The marine spermatophyte Thalassia testudinum is the dominant seagrass in southeast Florida and the Florida Gulf coast. The trophic interaction between the fishes and the macrobenthic and cryptic fauna found in the area was examined. Based on digestive tract analysis, the principal interaction between the primary consumers of the study area and the higher trophic level predators was via the polychaetes and peracaridean crustaceans. The mollusks which contributed significantly to the benthic biomass were not a preferred food for the animals frequenting the study site. The maximummore » mollusk biomass in any benthic and cryptic sample was 2.31 g dry/m/sup 2/. It was felt that the predator population was limited by the small stock of polychaetes and peracaridean crustaceans which had a maximum biomass in any one sample equivalent to 1.74 g dry/m/sup 2/. The majority of the fishes captured were foragers over a wide area. The main residents were the syngnathids and the gold-spotted killifish, Floridichthys carpio.« less

Worms Expelled With the Urine From a Bosniak Cyst III of the Left Kidney.

PubMed

Yang, Jie; Li, Pu; Su, Chuan; Zhang, Jia-Yi; Gu, Min

2016-07-01

An old fishman presented with left lumbago and finding worms in his urine. Type-B ultrasonic inspection and computed tomography scan found a Bosniak cyst III, containing several wire-like elements, in the middle of the left kidney. Expelled worms were confirmed to be Dioctophyma renale. After two courses of albendazole, the man was cured. Copyright © 2016 Elsevier Inc. All rights reserved.

The TRiC/CCT chaperone is implicated in Alzheimer's disease based on patient GWAS and an RNAi screen in Aβ-expressing Caenorhabditis elegans.

PubMed

Khabirova, Eleonora; Moloney, Aileen; Marciniak, Stefan J; Williams, Julie; Lomas, David A; Oliver, Stephen G; Favrin, Giorgio; Sattelle, David B; Crowther, Damian C

2014-01-01

The human Aβ peptide causes progressive paralysis when expressed in the muscles of the nematode worm, C. elegans. We have exploited this model of Aβ toxicity by carrying out an RNAi screen to identify genes whose reduced expression modifies the severity of this locomotor phenotype. Our initial finding was that none of the human orthologues of these worm genes is identical with the genome-wide significant GWAS genes reported to date (the "white zone"); moreover there was no identity between worm screen hits and the longer list of GWAS genes which included those with borderline levels of significance (the "grey zone"). This indicates that Aβ toxicity should not be considered as equivalent to sporadic AD. To increase the sensitivity of our analysis, we then considered the physical interactors (+1 interactome) of the products of the genes in both the worm and the white+grey zone lists. When we consider these worm and GWAS gene lists we find that 4 of the 60 worm genes have a +1 interactome overlap that is larger than expected by chance. Two of these genes form a chaperonin complex, the third is closely associated with this complex and the fourth gene codes for actin, the major substrate of the same chaperonin.

Growth and development of Gymnophalloides seoi in immunocompetent and immunosuppressed C3H/HeN mice

PubMed Central

Chung, Won-Jae; Kook, Jina; Seo, Min; Park, Yun-Kyu; Guk, Sang-Mee; Choi, Min-Ho; Lee, Soon-Hyung

1999-01-01

The growth and development of Gymnophalloides seoi were studied in C3H/HeN mice and effects of immunosuppression of the host on the worm development were observed. Two hundred metacercariae of G. seoi were orally administered to each mouse, and worms were recovered on days 1, 3, 5, 7, 14 and 21 post-infection (PI). The worm recovery rate was significantly higher in immunosuppressed (ImSP) mice than in immunocompetent (ImCT) mice except on days 1 and 3 PI. The worms attained sexual maturity by day 3 PI with eggs in the uterus, and worm dimensions and the number of uterine eggs continuously increased until day 14 PI in ImSP mice. Worms recovered from ImSP mice were significantly larger in size than those from ImCT mice on days 1 and 3 PI, and the number of uterine eggs was significantly larger in ImSP mice on days 5 and 7 PI. Genital organs such as the ovary, testes, and vitellaria, that were already developed in the metacercarial stage, grew a little in size until day 14 PI. The results show that the C3H/HeN mouse is, though not excellent, a suitable laboratory host for G. seoi. PMID:10188379

Bioimmunological responses to Schistosoma mansoni and Fasciola gigantica worm homogenates either with or without saponin.

PubMed

Maghraby, Amany Sayed; Hamed, Manal Abdel-Aziz; Ali, Sanaa Ahmed

2010-06-03

In this study, we evaluated the biochemical, immunological, histopathological and antischistosomal activities of Schistosoma mansoni or Fasciola gigantica worm homogenates mixed either with or without saponin that was extracted from Atriplex nummularia. The immunization schedule was based on subcutaneous administration of two doses (50 microg /100 microl PBS) of each homogenate with time intervals of 15 days. After 15 days of the last homogenate inoculation, all mice were challenged with 100 Schistosoma mansoni cercariae and sacrificed after two months. Free radical scavengers and liver function enzymes were determined in mice liver. Worm counting and the histopathological picture of the liver were also done. Immunization with Schistosoma or Fasciola worm homogenates, mixed either with or without saponin, recorded an amelioration of the free radical scavenger levels, liver function enzymes and reduction in worm burden, as well as improvement of the histological feature of the liver, the number and size of granuloma, evidence of increased immune reaction manifested by a lymphocytic cuff surrounding the granuloma, diminution of its fibrotic and collagen content, and destruction of Schistosoma ova. Fasciola or Schistosoma worm antigens mixed with or without saponin succeeded to eliminate the product of oxidative stress and assistance in immune-mediated destruction of eggs that ameliorate the histopathological picture of the liver cells and preserve its function.

WormClassroom.org: An Inquiry-rich Educational Web Portal for Research Resources of Caenorhabditis elegans

PubMed Central

Lu, Fong-Mei; Stewart, James; White, John G.

2007-01-01

The utilization of biology research resources, coupled with a “learning by inquiry” approach, has great potential to aid students in gaining an understanding of fundamental biological principles. To help realize this potential, we have developed a Web portal for undergraduate biology education, WormClassroom.org, based on current research resources of a model research organism, Caenorhabditis elegans. This portal is intended to serve as a resource gateway for students to learn biological concepts using C. elegans research material. The driving forces behind the WormClassroom website were the strengths of C. elegans as a teaching organism, getting researchers and educators to work together to develop instructional materials, and the 3 P's (problem posing, problem solving, and peer persuasion) approach for inquiry learning. Iterative assessment is an important aspect of the WormClassroom site development because it not only ensures that content is up-to-date and accurate, but also verifies that it does, in fact, aid student learning. A primary assessment was performed to refine the WormClassroom website utilizing undergraduate biology students and nonstudent experts such as C. elegans researchers; results and comments were used for site improvement. We are actively encouraging continued resource contributions from the C. elegans research and education community for the further development of WormClassroom. PMID:17548872

Gastrointestinal nematode infections in sheep raised in Botucatu, state of São Paulo, Brazil.

PubMed

Wilmsen, Maurício Orlando; Silva, Bruna Fernanda; Bassetto, César Cristiano; Amarante, Alessandro Francisco Talamini do

2014-01-01

Gastrointestinal nematode infections were evaluated in sheep raised in Botucatu, state of São Paulo, Brazil between April 2008 and March 2011. Every month, two tracer lambs grazing with a flock of sheep were exposed to natural infection with gastrointestinal nematodes for 28 consecutive days. At the end of this period, the lambs were sacrificed for worm counts. Haemonchus contortus presented 100% of prevalence. The seasons exerted no significant influence on the mean intensity of H. contortus, which ranged from 315 worms in November 2010 to 2,5205 worms in January 2011. The prevalence of Trichostrongylus colubriformis was also 100%, with the lowest mean intensity (15 worms) recorded in February 2011 and the highest (9,760 worms) in October 2009. In the case of T. colubriformis, a significant correlation coefficient was found between worm counts vs. rainfall (r = -0.32; P <0.05). Three other nematodes species were found in tracer lambs, albeit in small numbers. Their prevalence and mean intensity (in parenthesis) were as follows: Oesophagostomum columbianum 28% (25.2), Cooperia curticei 7% (4.5) and Trichuris spp. 2% (1). In conclusion, the environmental conditions of the area proved to be highly favorable for the year-round transmission of H. contortus and T. colubriformis.

Faecal egg counts and expulsion dynamics of the whipworm, Trichuris trichiura following self-infection.

PubMed

Hansen, E P; Tejedor, A M; Thamsborg, S M; Alstrup Hansen, T V; Dahlerup, J F; Nejsum, P

2016-05-01

More than 400 million humans are estimated to be infected with the intestinal helminth parasite, Trichuris trichiura. The infection is chronic in nature and high-intensity infection can lead to colitis, anaemia, Trichuris Dysentery Syndrome and reduced cognitive performance. Single doses of 400 mg albendazole or 500 mg mebendazole (MBZ) are used in mass drug administration programmes, but this has been shown to be insufficient. In this study, worm expulsion dynamics are described after MBZ treatment, given as a multi-dose and single-dose treatment in two separate T. trichiura self-infection studies. Worm expulsion dynamics post-treatment showed a similar pattern regardless of the dose regime, with the first worms observed on day 2 and the last worms expelled on days 9 and 13 post-treatment. Establishment of a chronic infection was observed following the inefficient single-dose treatment. The prepatent period was 13-16 weeks in both studies and worms were found to have a lifespan of at least 1 year and 10 months. These self-infection studies provide key information on the chronicity of T. trichiura infections, expulsion dynamics after anthelmintic treatment and the prepatent period, as well as the fecundity of female worms, which was around 18,000 eggs/female per day.

Procyanidins from apples (Malus pumila Mill.) extend the lifespan of Caenorhabditis elegans.

PubMed

Sunagawa, Tadahiro; Shimizu, Takahiko; Kanda, Tomomasa; Tagashira, Motoyuki; Sami, Manabu; Shirasawa, Takuji

2011-01-01

Apple polyphenols (AP) mainly consist of procyanidins (PC), which are composed of (-)-epicatechins and (+)-catechins. In order to investigate the antiageing effects of PC, we measured the lifespan of CAENORHABDITIS ELEGANS worms treated with PC. Treatment with 65 µg/mL PC extended the mean lifespan of wild-type N2 and FEM-1 worms by 12.1 % and 8.4 %, respectively, i.e., to a similar extent as resveratrol. In addition, treatment with 100 µg/mL AP also significantly prolonged the mean lifespan of the same worms by 12.0 % and 5.3 %, respectively, i.e., to a similar extent as PC. In contrast, treatment with (-)-epicatechin did not extend the lifespan of the worms. PC did not modify the growth, food intake, or fecundity of C. elegans. Treatment with PC did not extend the lifespan of MEV-1 worms, which show excessive oxidative stress, indicating that PC had no antioxidant ability in the MEV-1 mutant. Moreover, treatment with PC had no effect on the longevity of SIR-2.1 worms, which lack the activity of SIR-2, a member of the sirtuin family of NAD (+)-dependent protein deacetylases. These results indicated that PC has SIR-2.1-dependent antiageing effects on C. elegans. © Georg Thieme Verlag KG Stuttgart · New York.

Schistosoma mansoni: is acquired immunity induced by highly x-irradiated cercariae dependent on the size of the challenging dose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsue, S.Y.; Hsue, H.F.; Osborne, J.W.

1982-04-01

A high degree of immunity, as shown by a 91% reduction of the number of worms recovered was found in five groups of mice that were immunized five times with highly X-irradiated cercariae and then challenged with 10, 20, 50, 100, or 500 normal Schistosoma mansoni cercariae. The results indicated that there were no significant differences in worm reduction in immunized mice challenged with different numbers of cercariae; consequently the immunity induced by this immunization method did not appear to be challenge-dose-dependent. However, the results also showed that when immunized mice were challenged with 500, 100, 50, 20, and 10more » cercariae, 0, 13, 26, 56, and 68%, respectively, of the experimental animals were free of worms. Thus, the percentage of worm-negative cases increased as the number of challenge cercariae decreased. When viewed in this manner, the acquired immunity may be considered challenge-dose-dependent as well. If this method of vaccination is used for schistosomiasis control, we may anticipate that in both hypo- and hyperendemic areas, the intensity of infection and the severity of the disease will be reduced owing to a reduction in worms burdens, and in hypoendemic areas, there will be a number of worm-free cases.« less

Ecological evaluation of proposed dredged material from Richmond Harbor Deepening Project and the intensive study of the Turning Basin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinza, M.R.; Mayhew, H.L.; Karle, L.M.

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 conductmore » 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.« less

The Discovery of New Deep-Sea Hydrothermal Vent Communities in the Southern Ocean and Implications for Biogeography

PubMed Central

Rogers, Alex D.; Tyler, Paul A.; Connelly, Douglas P.; Copley, Jon T.; James, Rachael; Larter, Robert D.; Linse, Katrin; Mills, Rachel A.; Garabato, Alfredo Naveira; Pancost, Richard D.; Pearce, David A.; Polunin, Nicholas V. C.; German, Christopher R.; Shank, Timothy; Boersch-Supan, Philipp H.; Alker, Belinda J.; Aquilina, Alfred; Bennett, Sarah A.; Clarke, Andrew; Dinley, Robert J. J.; Graham, Alastair G. C.; Green, Darryl R. H.; Hawkes, Jeffrey A.; Hepburn, Laura; Hilario, Ana; Huvenne, Veerle A. I.; Marsh, Leigh; Ramirez-Llodra, Eva; Reid, William D. K.; Roterman, Christopher N.; Sweeting, Christopher J.; Thatje, Sven; Zwirglmaier, Katrin

2012-01-01

Since the first discovery of deep-sea hydrothermal vents along the Galápagos Rift in 1977, numerous vent sites and endemic faunal assemblages have been found along mid-ocean ridges and back-arc basins at low to mid latitudes. These discoveries have suggested the existence of separate biogeographic provinces in the Atlantic and the North West Pacific, the existence of a province including the South West Pacific and Indian Ocean, and a separation of the North East Pacific, North East Pacific Rise, and South East Pacific Rise. The Southern Ocean is known to be a region of high deep-sea species diversity and centre of origin for the global deep-sea fauna. It has also been proposed as a gateway connecting hydrothermal vents in different oceans but is little explored because of extreme conditions. Since 2009 we have explored two segments of the East Scotia Ridge (ESR) in the Southern Ocean using a remotely operated vehicle. In each segment we located deep-sea hydrothermal vents hosting high-temperature black smokers up to 382.8°C and diffuse venting. The chemosynthetic ecosystems hosted by these vents are dominated by a new yeti crab (Kiwa n. sp.), stalked barnacles, limpets, peltospiroid gastropods, anemones, and a predatory sea star. Taxa abundant in vent ecosystems in other oceans, including polychaete worms (Siboglinidae), bathymodiolid mussels, and alvinocaridid shrimps, are absent from the ESR vents. These groups, except the Siboglinidae, possess planktotrophic larvae, rare in Antarctic marine invertebrates, suggesting that the environmental conditions of the Southern Ocean may act as a dispersal filter for vent taxa. Evidence from the distinctive fauna, the unique community structure, and multivariate analyses suggest that the Antarctic vent ecosystems represent a new vent biogeographic province. However, multivariate analyses of species present at the ESR and at other deep-sea hydrothermal vents globally indicate that vent biogeography is more complex than previously recognised. PMID:22235194

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.

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.

Middle to late Cambrian shallow marine trace fossils from the Imfout Syncline (Western Meseta, Morocco): Palaeoecological and palaeoenvironmental significance in NW-Gondwana

NASA Astrophysics Data System (ADS)

Oukassou, Mostafa; Lagnaoui, Abdelouahed; Raji, Mohammed; Michard, André; Saddiqi, Omar

2017-05-01

The present research provides the first evidence of invertebrate activity assigned to the ichnogenus Selenichnites occurring together with moderately diverse ichnofossils from the middle to late Cambrian of the Moroccan Meseta. The invertebrate traces occur in sandstone strata of the El Hank Formation within the Imfout Syncline, in the northern part of the Rehamna Massif (Coastal Block, western Moroccan Meseta). Bedding surfaces from the top of the El Hank Formation near the Imfout Dam show diverse forms of current ripples and distincts crescentic ichnofossils in concave epirelief scattered on the surface. In this section, the traces provide evidence of the ethology of an organism inhabiting the relatively shallow waters of the area during this time. Selenichnites co-occurs with the ichnogenera Arenicolites, Diplocraterion, Lingulichnus, Monocraterion, Skolithos and unidentified burrows, and the ichnoassemblage is referred to the Skolithos ichnofacies. These traces can be referred to arthropods (e.g. polychaete worms and amphipod crustaceans), lingulid brachiopods, annelids and/or phoronids. The Imfout Selenichnites represents the first occurrence of this ichnogenus from the Cambrian of the Moroccan Meseta, and the second from the Cambrian deposits of Morocco. The potential tracemakers are still questionable, but were most likely xiphosurans, trilobites, euthycarcinoids or crustaceans. If so, the Imfout traces could be among the oldest pieces of evidence for the presence of horseshoe crabs during the Cambrian. The combination of sedimentological and ichnological data indicates that the El Hank Formation was deposited in a sublittoral soft ground environment next to a sandy shore. It was originally part of an early Palaeozoic shallow marine epicontinental platform in west-central Morocco. In addition to the equivalent Cambrian deposits from the Anti-Atlas, the El Hank Formation constituted a part of the northern Gondwana platform domain during the transgression coming from the Rheic Ocean onto the West African Craton margin.

A new phylogeny and environmental DNA insight into paramyxids: an increasingly important but enigmatic clade of protistan parasites of marine invertebrates.

PubMed

Ward, Georgia M; Bennett, Martyn; Bateman, Kelly; Stentiford, Grant D; Kerr, Rose; Feist, Stephen W; Williams, Suzanne T; Berney, Cedric; Bass, David

2016-09-01

Paramyxida is an order of rhizarian protists that parasitise marine molluscs, annelids and crustaceans. They include notifiable pathogens (Marteilia spp.) of bivalves and other taxa of economic significance for shellfish production. The diversity of paramyxids is poorly known, particularly outside of commercially important hosts, and their phylogenetic position is unclear due to their extremely divergent 18S rDNA sequences. However, novel paramyxean lineages are increasingly being detected in a wide range of invertebrate hosts, and interest in the group is growing, marked by the first 'Paramyxean Working Group' Meeting held in Spain in February 2015. We review the diversity, host affiliations, and geographical ranges of all known paramyxids, present a comprehensive phylogeny of the order and clarify its taxonomy. Our phylogenetic analyses confirm the separate status of four genera: Paramarteilia, Marteilioides, Paramyxa and Marteilia. Further, as including M. granula in Marteilia would make the genus paraphyletic we suggest transferring this species to a new genus, Eomarteilia. We present sequence data for Paramyxa nephtys comb. n., a parasite of polychaete worms, providing morphological data for a clade of otherwise environmental sequences, sister to Marteilioides. Light and electron microscopy analyses show strong similarities with both Paramyxa and Paramyxoides, and we further discuss the validity of those two genera. We provide histological and electron microscopic data for Paramarteilia orchestiae, the type species of that genus originally described from the amphipod Orchestia; in situ hybridisation shows that Paramarteilia also infects crab species. We present, to our knowledge, the first known results of a paramyxid-specific environmental DNA survey of environmental (filtered water, sediment, etc.) and organismally-derived samples, revealing new lineages and showing that paramyxids are associated with a wider range of hosts and habitat types than previously known. On the basis of our new phylogeny we propose phylogenetic hypotheses for evolution of lifecycle and infectivity traits observed in different paramyxid genera. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Stocking Density Optimization for Enhanced Bioconversion of Fly Ash Enriched Vermicompost.

PubMed

Mupambwa, Hupenyu A; Mnkeni, Pearson N S

2016-05-01

Although it is widely agreed that stocking density critically affects the rate of vermicomposting, there is no established stocking density for mixtures of fly ash and other waste materials. This study sought to optimize (Savigny, 1826) stocking density for effective biodegradation and nutrient release in a fly ash-cow dung-waste paper (FCP) mixture. Four stocking densities of 0, 12.5, 25, and 37.5 g worms kg were evaluated. Although the 12.5, 25, and 37.5 g worms kg treatments all resulted in a mature vermicompost, stocking densities of 25 and 37.5 g worms kg resulted in faster maturity, higher humification parameters, and a significantly lower final C/N ratio (range 11.1-10.4). The activity of β-glucosidase and fluorescein diacetate hydrolysis enzymes showed faster stabilization at stocking densities of 25 and 37.5 g worms kg, indicating compost stability and maturity. Similarly, a stocking density of 25 g worms kg resulted in the highest release of Olsen-extractable P and (NO + NO)-N contents. The 0-, 12.5-, 25-, and 37.5-g treatments resulted in net Olsen P increases of 16.3, 38.9, 61.0, and 53.0%, respectively, after 10 wk. Although compost maturity could be attained at stocking densities of 12.5 g worms kg, for faster production of humified and nutrient-rich FCP vermicompost, a stocking density of 25 g worms kg seems most appropriate. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Macrofilaricidal and microfilaricidal effects of Neurolaena lobata, a Guatemalan medicinal plant, on Brugia pahangi.

PubMed

Fujimaki, Y; Kamachi, T; Yanagi, T; Cáceres, A; Maki, J; Aoki, Y

2005-03-01

Twelve extracts of 11 Guatemalan medicinal plants were initially screened in vitro for potential macrofilaricidal activity against Brugia pahangi, a lymphatic dwelling filarial worm, using concentrations from 125 to 1000 microg ml(-1) of each extract that could be dissolved in the culture medium. Of 12 extracts used, the ethanol extract of leaves of Neurolaena lobata showed the strongest activity against the motility of adult worms. Subsequently, the extract of N. lobata was extensively examined in vitro for macro- and micro-filaricidal effects using a series of concentrations of 500, 250, 100, 50 and 10 microg ml(-1). The effects were assessed by worm motility, microfilarial release by female worms and a MTT assay. The effect on the motility of adult worms was observed in a concentration- and time-dependent manner. The time required to stop motility of both sexes of adult worms was 6 h at 500 microg ml(-1), 24 h at 250 microg ml(-1), and 3 days for females and 4 days for males at 100 microg ml(-1). The movement of females ceased at 4 days at a concentration of 50 microg ml(-1) whereas the motility of males was only reduced. The loss of worm's viability was confirmed by the MTT assay and was similar to the motility results. These concentrations, including 10 microg ml(-1), prevented microfilarial release by females in a concentration- and time-dependent manner. Concentrations higher than 100 microg ml(-1) even induced mortality of the microfilariae. The present study suggested that the ethanol extract of Neurolaena lobata has potential macro- and micro-filaricidal activities.

A microfluidic device for automated, high-speed microinjection of Caenorhabditis elegans

PubMed Central

Song, Pengfei; Dong, Xianke; Liu, Xinyu

2016-01-01

The nematode worm Caenorhabditis elegans has been widely used as a model organism in biological studies because of its short and prolific life cycle, relatively simple body structure, significant genetic overlap with human, and facile/inexpensive cultivation. Microinjection, as an established and versatile tool for delivering liquid substances into cellular/organismal objects, plays an important role in C. elegans research. However, the conventional manual procedure of C. elegans microinjection is labor-intensive and time-consuming and thus hinders large-scale C. elegans studies involving microinjection of a large number of C. elegans on a daily basis. In this paper, we report a novel microfluidic device that enables, for the first time, fully automated, high-speed microinjection of C. elegans. The device is automatically regulated by on-chip pneumatic valves and allows rapid loading, immobilization, injection, and downstream sorting of single C. elegans. For demonstration, we performed microinjection experiments on 200 C. elegans worms and demonstrated an average injection speed of 6.6 worm/min (average worm handling time: 9.45 s/worm) and a success rate of 77.5% (post-sorting success rate: 100%), both much higher than the performance of manual operation (speed: 1 worm/4 min and success rate: 30%). We conducted typical viability tests on the injected C. elegans and confirmed that the automated injection system does not impose significant adverse effect on the physiological condition of the injected C. elegans. We believe that the developed microfluidic device holds great potential to become a useful tool for facilitating high-throughput, large-scale worm biology research. PMID:26958099

Global Coordination and Standardisation in Marine Biodiversity through the World Register of Marine Species (WoRMS) and Related Databases

PubMed Central

Bouchet, Philippe; Boxshall, Geoff; Fauchald, Kristian; Gordon, Dennis; Hoeksema, Bert W.; Poore, Gary C. B.; van Soest, Rob W. M.; Stöhr, Sabine; Walter, T. Chad; Vanhoorne, Bart; Decock, Wim

2013-01-01

The World Register of Marine Species is an over 90% complete open-access inventory of all marine species names. Here we illustrate the scale of the problems with species names, synonyms, and their classification, and describe how WoRMS publishes online quality assured information on marine species. Within WoRMS, over 100 global, 12 regional and 4 thematic species databases are integrated with a common taxonomy. Over 240 editors from 133 institutions and 31 countries manage the content. To avoid duplication of effort, content is exchanged with 10 external databases. At present WoRMS contains 460,000 taxonomic names (from Kingdom to subspecies), 368,000 species level combinations of which 215,000 are currently accepted marine species names, and 26,000 related but non-marine species. Associated information includes 150,000 literature sources, 20,000 images, and locations of 44,000 specimens. Usage has grown linearly since its launch in 2007, with about 600,000 unique visitors to the website in 2011, and at least 90 organisations from 12 countries using WoRMS for their data management. By providing easy access to expert-validated content, WoRMS improves quality control in the use of species names, with consequent benefits to taxonomy, ecology, conservation and marine biodiversity research and management. The service manages information on species names that would otherwise be overly costly for individuals, and thus minimises errors in the application of nomenclature standards. WoRMS' content is expanding to include host-parasite relationships, additional literature sources, locations of specimens, images, distribution range, ecological, and biological data. Species are being categorised as introduced (alien, invasive), of conservation importance, and on other attributes. These developments have a multiplier effect on its potential as a resource for biodiversity research and management. As a consequence of WoRMS, we are witnessing improved communication within the scientific community, and anticipate increased taxonomic efficiency and quality control in marine biodiversity research and management. PMID:23505408

AN ORIENTATIONAL RESPONSE TO WEAK GAMMA RADIATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, F.A. Jr.

1963-10-01

The common planarian worm, Duesia dorotocephsla, displays a significant orientational response to increase in Cs/sup 137/ gamma radiation when the increase is no greater than six times background. The worms are able to distinguish the direction of the weak gamma source, turning away from it, whether it is presented on the right or left side. The response sign is, therefore, the same as that of the response of these negatively phototactic worms to visible light. There is a clear compass-directional relationship of the responsiveness to the experimental gamma radiation. A conspicuous negative response is present when the worms are travelingmore » northward or southward in the earth's field with the gamma change in an east-west axis. No statistically significant mean turning response to the gamma radiation is found when the worms are traveling eastward or westward in the earth's field with the gamma change in a north-south axis. The previously observed annual fluctuation in the character of the monthly orientational rhythm of north-directed worms has been confirmed in an additional year of study. During colder months, the rhythm is monthly; during warmer months it is semi-monthly. There is a semi-monthly fluctuation in the response of Dugesia to weak gamma radiation during mid-morning hours, the worms turning away from the source for four days prior to new end full moon, and toward it for two days following new and full moon. The stronger the field strength, up to 9 times backgound, the larger the amplitude of the rhythm. There is a direct relationship between intensities of gamma radiation between that of background and nine times backgound, and the strength of the negative response of the worms. Evidence suggests that the negative response of Dugesia to a gamma source may be modified by experimental alteration of the natural ambient electrostatic field. Some possible biological significances of this remarkable responsiveness to gamma radiation, and its particular properties, are discussed briefly. (auth)« less

Track-A-Worm, An Open-Source System for Quantitative Assessment of C. elegans Locomotory and Bending Behavior

PubMed Central

Wang, Sijie Jason; Wang, Zhao-Wen

2013-01-01

A major challenge of neuroscience is to understand the circuit and gene bases of behavior. C. elegans is commonly used as a model system to investigate how various gene products function at specific tissue, cellular, and synaptic foci to produce complicated locomotory and bending behavior. The investigation generally requires quantitative behavioral analyses using an automated single-worm tracker, which constantly records and analyzes the position and body shape of a freely moving worm at a high magnification. Many single-worm trackers have been developed to meet lab-specific needs, but none has been widely implemented for various reasons, such as hardware difficult to assemble, and software lacking sufficient functionality, having closed source code, or using a programming language that is not broadly accessible. The lack of a versatile system convenient for wide implementation makes data comparisons difficult and compels other labs to develop new worm trackers. Here we describe Track-A-Worm, a system rich in functionality, open in source code, and easy to use. The system includes plug-and-play hardware (a stereomicroscope, a digital camera and a motorized stage), custom software written to run with Matlab in Windows 7, and a detailed user manual. Grayscale images are automatically converted to binary images followed by head identification and placement of 13 markers along a deduced spline. The software can extract and quantify a variety of parameters, including distance traveled, average speed, distance/time/speed of forward and backward locomotion, frequency and amplitude of dominant bends, overall bending activities measured as root mean square, and sum of all bends. It also plots worm travel path, bend trace, and bend frequency spectrum. All functionality is performed through graphical user interfaces and data is exported to clearly-annotated and documented Excel files. These features make Track-A-Worm a good candidate for implementation in other labs. PMID:23922769

Uptake of TiO2 Nanoparticles into C. elegans Neurons Negatively Affects Axonal Growth and Worm Locomotion Behavior.

PubMed

Hu, Chun-Chih; Wu, Gong-Her; Hua, Tzu-En; Wagner, Oliver I; Yen, Ta-Jen

2018-03-14

We employ model organism Caenorhabditis elegans to effectively study the toxicology of anatase and rutile phase titanium dioxide (TiO 2 ) nanoparticles (NPs). The experimental results show that nematode C. elegans can take up fluorescein isothiocyanate-labeled TiO 2 NPs and that both anatase and rutile TiO 2 NPs can be detected in the cytoplasm of cultured primary neurons imaged by transmission electron microscopy. After TiO 2 NP exposure, these neurons also grow shorter axons, which may be related to the detected impeded worm locomotion behavior. Furthermore, anatase TiO 2 NPs did not affect the worm's body length; however, we determined that a concentration of 500 μg/mL of anatase TiO 2 NPs reduced the worm population by 50% within 72 h. Notably, rutile TiO 2 NPs negatively affect both the body size and worm population. Worms unable to enter the L4 larval stage explain a severe reduction in the worm population at TiO 2 NPs LC 50 /3d. To obtain a better understanding of the cellular mechanisms involved in TiO 2 NP intoxication, DNA microarray assays were employed to determine changes in gene expression in the presence or absence of TiO 2 NP exposure. Our data reveal that three genes (with significant changes in expression levels) were related to metal binding or metal detoxification (mtl-2, C45B2.2, and nhr-247), six genes were involved in fertility and reproduction (mtl-2, F26F2.3, ZK970.7, clec-70, K08C9.7, and C38C3.7), four genes were involved in worm growth and body morphogenesis (mtl-2, F26F2.3, C38C3.7, and nhr-247), and five genes were involved in neuronal function (C41G6.13, C45B2.2, srr-6, K08C9.7, and C38C3.7).

Global coordination and standardisation in marine biodiversity through the World Register of Marine Species (WoRMS) and related databases.

PubMed

Costello, Mark J; Bouchet, Philippe; Boxshall, Geoff; Fauchald, Kristian; Gordon, Dennis; Hoeksema, Bert W; Poore, Gary C B; van Soest, Rob W M; Stöhr, Sabine; Walter, T Chad; Vanhoorne, Bart; Decock, Wim; Appeltans, Ward

2013-01-01

The World Register of Marine Species is an over 90% complete open-access inventory of all marine species names. Here we illustrate the scale of the problems with species names, synonyms, and their classification, and describe how WoRMS publishes online quality assured information on marine species. Within WoRMS, over 100 global, 12 regional and 4 thematic species databases are integrated with a common taxonomy. Over 240 editors from 133 institutions and 31 countries manage the content. To avoid duplication of effort, content is exchanged with 10 external databases. At present WoRMS contains 460,000 taxonomic names (from Kingdom to subspecies), 368,000 species level combinations of which 215,000 are currently accepted marine species names, and 26,000 related but non-marine species. Associated information includes 150,000 literature sources, 20,000 images, and locations of 44,000 specimens. Usage has grown linearly since its launch in 2007, with about 600,000 unique visitors to the website in 2011, and at least 90 organisations from 12 countries using WoRMS for their data management. By providing easy access to expert-validated content, WoRMS improves quality control in the use of species names, with consequent benefits to taxonomy, ecology, conservation and marine biodiversity research and management. The service manages information on species names that would otherwise be overly costly for individuals, and thus minimises errors in the application of nomenclature standards. WoRMS' content is expanding to include host-parasite relationships, additional literature sources, locations of specimens, images, distribution range, ecological, and biological data. Species are being categorised as introduced (alien, invasive), of conservation importance, and on other attributes. These developments have a multiplier effect on its potential as a resource for biodiversity research and management. As a consequence of WoRMS, we are witnessing improved communication within the scientific community, and anticipate increased taxonomic efficiency and quality control in marine biodiversity research and management.

C. elegans positive butanone learning, short-term, and long-term associative memory assays.

PubMed

Kauffman, Amanda; Parsons, Lance; Stein, Geneva; Wills, Airon; Kaletsky, Rachel; Murphy, Coleen

2011-03-11

The memory of experiences and learned information is critical for organisms to make choices that aid their survival. C. elegans navigates its environment through neuron-specific detection of food and chemical odors, and can associate nutritive states with chemical odors, temperature, and the pathogenicity of a food source. Here, we describe assays of C. elegans associative learning and short- and long-term associative memory. We modified an aversive olfactory learning paradigm to instead produce a positive response; the assay involves starving ~400 worms, then feeding the worms in the presence of the AWC neuron-sensed volatile chemoattractant butanone at a concentration that elicits a low chemotactic index (similar to Toroyama et al.). A standard population chemotaxis assay1 tests the worms' attraction to the odorant immediately or minutes to hours after conditioning. After conditioning, wild-type animals' chemotaxis to butanone increases ~0.6 Chemotaxis Index units, its "Learning Index". Associative learning is dependent on the presence of both food and butanone during training. Pairing food and butanone for a single conditioning period ("massed training") produces short-term associative memory that lasts ~2 hours. Multiple conditioning periods with rest periods between ("spaced training") yields long-term associative memory (<40 hours), and is dependent on the cAMP Response Element Binding protein (CREB), a transcription factor required for long-term memory across species. Our protocol also includes image analysis methods for quick and accurate determination of chemotaxis indices. High-contrast images of animals on chemotaxis assay plates are captured and analyzed by worm counting software in MatLab. The software corrects for uneven background using a morphological tophat transformation. Otsu's method is then used to determine a threshold to separate worms from the background. Very small particles are removed automatically and larger non-worm regions (plate edges or agar punches) are removed by manual selection. The software then estimates the size of single worm by ignoring regions that are above a specified maximum size and taking the median size of the remaining regions. The number of worms is then estimated by dividing the total area identified as occupied by worms by the estimated size of a single worm. We have found that learning and short- and long-term memory can be distinguished, and that these processes share similar key molecules with higher organisms. Our assays can quickly test novel candidate genes or molecules that affect learning and short- or long-term memory in C. elegans that are relevant across species.

Gizzard worms

USGS Publications Warehouse

Tuggle, B.N.; Friend, M.

1999-01-01

Gizzard worms are comprised of several species of parasitic nematodes or roundworms of birds. Severe infections can result in birds becoming unthrifty and debilitated to the extent that they are more susceptible to predation and to infection by other disease agents. The two gizzard worms that are emphasized here are trichostrongylid nematodes that belong to the genera Amidostomum sp. and Epomidiostomum sp. These long (10–35 millimeter), sometimes coiled, threadlike roundworms are found just beneath the surface lining and the grinding pads of the gizzard, and they are most frequently found in waterfowl. Other species of gizzard worms are found in upland gamebirds such as grouse, in psitticine birds such as parakeets, and in passerine or perching birds such as robins in various parts of the world.

Fourier transform infrared microspectroscopy for the analysis of the biochemical composition of C. elegans worms.

PubMed

Sheng, Ming; Gorzsás, András; Tuck, Simon

2016-01-01

Changes in intermediary metabolism have profound effects on many aspects of C. elegans biology including growth, development and behavior. However, many traditional biochemical techniques for analyzing chemical composition require relatively large amounts of starting material precluding the analysis of mutants that cannot be grown in large amounts as homozygotes. Here we describe a technique for detecting changes in the chemical compositions of C. elegans worms by Fourier transform infrared microspectroscopy. We demonstrate that the technique can be used to detect changes in the relative levels of carbohydrates, proteins and lipids in one and the same worm. We suggest that Fourier transform infrared microspectroscopy represents a useful addition to the arsenal of techniques for metabolic studies of C. elegans worms.

Treatment of third-stage larvae of Toxocara cati with milbemycin oxime plus praziquantel tablets and emodepside plus praziquantel spot-on formulation in experimentally infected cats.

PubMed

Wolken, Sonja; Böhm, Claudia; Schaper, Roland; Schnieder, Thomas

2012-11-01

Toxocara cati is the most prevalent gastrointestinal helminth in cats worldwide, with cats of all ages at risk of infection. An anthelminthic treatment that not only affects the gut-dwelling stages of this parasite but is also effective against developmental stages in the tissue has the advantage that the pathology caused by migrating larvae is minimized and the need for repeated treatments is reduced. This study was conducted to evaluate the efficacy of milbemycin oxime/praziquantel tablets (Milbemax®, Novartis) against third-stage larvae of T. cati in comparison to a spot-on formulation of emodepside and praziquantel (Profender®, Bayer). Twenty-four kittens were experimentally infected with T. cati and randomly allocated to three study groups. Treatments were performed at the minimum therapeutic dosage 5 days after the experimental infection. The development of patent infections was monitored and all cats were dewormed 50 days post-infection. Efficacies were calculated based on counts of excreted worms in the treated groups compared to a negative control group. Seven of the eight cats in the negative control group developed a patent T. cati infection and all cats were excreting worms at the end of the study (geometric mean worm count 18.1). No efficacy could be observed for the milbemycin oxime-treated animals. All cats developed a patent infection and excreted worms (geometric mean worm count 27.7). The treatment with Profender® was 98.5 % effective against L3 of T. cati. One cat developed a patent infection and was excreting worms at the end of the study (geometric mean worm count 0.3). No adverse reactions were noted in either treatment group.

Preparation of Pickering Double Emulsions Using Block Copolymer Worms

PubMed Central

2015-01-01

The rational formulation of Pickering double emulsions is described using a judicious combination of hydrophilic and hydrophobic block copolymer worms as highly anisotropic emulsifiers. More specifically, RAFT dispersion polymerization was utilized to prepare poly(lauryl methacrylate)–poly(benzyl methacrylate) worms at 20% w/w solids in n-dodecane and poly(glycerol monomethacrylate)–poly(2-hydroxypropyl methacrylate)–poly(benzyl methacrylate) worms at 13% w/w solids in water by polymerization-induced self-assembly (PISA). Water-in-oil-in-water (w/o/w) double emulsions can be readily prepared with mean droplet diameters ranging from 30 to 80 μm using a two-stage approach. First, a w/o precursor emulsion comprising 25 μm aqueous droplets is prepared using the hydrophobic worms, followed by encapsulation within oil droplets stabilized by the hydrophilic worms. The double emulsion droplet diameter and number of encapsulated water droplets can be readily varied by adjusting the stirring rate employed during the second stage. For each stage, the droplet volume fraction is relatively high at 0.50. The double emulsion nature of the final formulation was confirmed by optical and fluorescence microscopy studies. Such double emulsions are highly stable to coalescence, with little or no change in droplet diameter being detected over storage at 20 °C for 10 weeks as judged by laser diffraction. Preliminary experiments indicate that the complementary o/w/o emulsions can also be prepared using the same pair of worms by changing the order of homogenization, although somewhat lower droplet volume fractions were required in this case. Finally, we demonstrate that triple and even quadruple emulsions can be formulated using these new highly anisotropic Pickering emulsifiers. PMID:25834923

Mortality of Rocky Mountain elk in Michigan due to meningeal worm.

PubMed

Bender, Louis C; Schmitt, Stephen M; Carlson, Elaine; Haufler, Jonathan B; Beyer, Dean E

2005-01-01

Mortality from cerebrospinal parelaphostrongylosis caused by the meningeal worm (Parelaphostrongylus tenuis) has been hypothesized to limit elk (Cervus elaphus nelsoni) populations in areas where elk are conspecific with white-tailed deer (Odocoileus virginianus). Elk were reintroduced into Michigan (USA) in the early 1900s and subsequently greatly increased population size and distribution despite sympatric high-density (>or=12/km2) white-tailed deer populations. We monitored 100 radio-collared elk of all age and sex classes from 1981-94, during which time we documented 76 mortalities. Meningeal worm was a minor mortality factor for elk in Michigan and accounted for only 3% of mortalities, fewer than legal harvest (58%), illegal kills (22%), other diseases (7%), and malnutrition (4%). Across years, annual cause-specific mortality rates due to cerebrospinal parelaphostrongylosis were 0.033 (SE=0.006), 0.029 (SE=0.005), 0.000 (SE=0.000), and 0.000 (SE=0.000) for calves, 1-yr-old, 2-yr-old, and >or=3-yr-old, respectively. The overall population-level mortality rate due to cerebrospinal parelaphostrongylosis was 0.009 (SE=0.001). Thus, meningeal worm had little impact on elk in Michigan during our study despite greater than normal precipitation (favoring gastropods) and record (>or=14 km2) deer densities. Further, elk in Michigan have shown sustained population rates-of-increase of >or=18%/yr and among the highest levels of juvenile production and survival recorded for elk in North America, indicating that elk can persist in areas with meningeal worm at high levels of population productivity. It is likely that local ecologic characteristics among elk, white-tailed deer, and gastropods, and degree of exposure, age of elk, individual and population experience with meningeal worm, overall population vigor, and moisture determine the effects of meningeal worm on elk populations.

Mortality of rocky mountain elk in Michigan due to meningeal worm

USGS Publications Warehouse

Bender, L.C.; Schmitt, S.M.; Carlson, E.; Haufler, J.B.; Beyer, D.E.

2005-01-01

Mortality from cerebrospinal parelaphostrongylosis caused by the meningeal worm (Parelaphostrongylus tenuis) has been hypothesized to limit elk (Cervus elaphus nelsoni) populations in areas where elk are conspecific with white-tailed deer (Odocoileus virginianus). Elk were reintroduced into Michigan (USA) in the early 1900s and subsequently greatly increased population size and distribution despite sympatric high-density (???12/km2) white-tailed deer populations. We monitored 100 radio-collared elk of all age and sex classes from 1981-94, during which time we documented 76 mortalities. Meningeal worm was a minor mortality factor for elk in Michigan and accounted for only 3% of mortalities, fewer than legal harvest (58%), illegal kills (22%), other diseases (7%), and malnutrition (4%). Across years, annual cause-specific mortality rates due to cerebrospinal parelaphostrongylosis were 0.033 (SE=0.006), 0.029 (SE=0.005), 0.000 (SE=0.001), and 0.000 (SE=0.000) for calves, 1-yr-old, 2-yr-old, and ???3-yr-old, respectively. The overall population-level mortality rate due to cerebrospinal parelaphostrongylosis was 0.009 (SE=0.001). Thus, meningeal worm had little impact on elk in Michigan during our study despite greater than normal precipitation (favoring gastropods) and record (???14 km2) deer densities. Further, elk in Michigan have shown sustained population rates-of-increase of ???18%/yr and among the highest levels of juvenile production and survival recorded for elk in North America, indicating that elk can persist in areas with meningeal worm at high levels of population productivity. it is likely that local ecologic characteristics among elk, white-tailed deer, and gastropods, and degree of exposure, age of elk, individual and population experience with meningeal worm, overall population vigor, and moisture determine the effects of meningeal worm on elk populations. ?? Wildlife Disease Association 2005.

Eradicating guinea worm without wells: unrealized hopes of the Water Decade.

PubMed

Brieger, W R; Otusanya, S; Adeniyi, J D; Tijani, J; Banjoko, M

1997-12-01

At the start of the United Nations International Drinking Water Supply and Sanitation Decade in the 1980s, guinea worm disease was targeted as the major indicator of the success of the Decade's efforts to promote safe water. By the late 1980s, most of the guinea worm endemic countries in Africa and South Asia had established guinea worm eradication programmes that included water supply as one of their main technical strategies. By surveying the water supply situation in Ifeloju Local Government Area (LGA) in Oyo State, Nigeria, in June 1996, as a case study, it was possible to determine the role that water supply has played in the eradication effort. Although two major agencies, the former Directorate for Food, Roads and Rural Infrastructure and UNICEF, provided hand dug and bore-hole wells respectively in many parts of the LGA, coverage of the smaller farm hamlets has been minor compared to efforts in the larger towns. This is ironic because the farm hamlets served as a reservoir for the disease in the 1980s, such that when the piped water system in the towns broke down, guinea worm was easily reintroduced into the towns. The survey of 188 ever-endemic hamlets with an estimated population of 23,556 found that 74.3% of the people still drink only pond water. Another 11.3% have wells that have become dysfunctional. Only 14.4% of this rural population has access' to functioning wells. Guinea worm was eliminated from 107 of the hamlets mainly by the use of cloth filters and chemical treatment of ponds. While this proves that it is possible to eradicate guinea worm, it fails to leave behind the legacy of reliable, safe water supplies that was the hope of the Water Decade.

Drpiwi-1 is essential for germline cell formation during sexualization of the planarian Dugesia ryukyuensis.

PubMed

Nakagawa, Haruka; Ishizu, Hirotsugu; Hasegawa, Reiko; Kobayashi, Kazuya; Matsumoto, Midori

2012-01-01

A piwi homolog is required for the regulation of stem cells, formation and maintenance of germline stem cells, and gametogenesis in many metazoans. Planarians can change their reproductive mode seasonally, both asexually and sexually, and develop and maintain germ cells and sexual organs. They have many pluripotent stem cells (neoblasts) that can differentiate into both somatic and germline stem cells. Thus, we searched for a piwi subfamily in the planarian Dugesia ryukyuensis. Four piwi homologs, identified as Drpiwi-1, -2, -3, and -4, were expressed in sexually reproductive worms. We then selectively destroyed the neoblasts by irradiating the worms with X-rays. In such worms, Drpiwi-1, -2, and -3 were not expressed at all, whereas Drpiwi-4 was expressed to the same degree as that in non-irradiated controls, indicating that Drpiwi-1, -2, and -3, but not Drpiwi-4, are expressed in neoblasts. During the regeneration process, Drpiwi-2(RNAi) and -3(RNAi) worms failed to regenerate after ablation, but Drpiwi-1 and -4(RNAi) worms regenerated. During the sexualizing process, Drpiwi-1(RNAi) worms failed to develop ovaries and testes, but somatic sexual organs were unaffected. Germ cell development was normal in Drpiwi-4(RNAi) worms. Therefore, Drpiwi-2 and -3 may be related to the regulation of neoblasts important for maintaining homeostasis, and Drpiwi-1 is essential for the development of germ cells but not somatic sexual organs. DrPiwi-1 is localized in the cytoplasm of stem cells and germline cells and may be involved in regulating some gene expression. We suggest that planarian Piwi controls germline formation via RNA silencing mechanisms. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

Predicting path from undulations for C. elegans using linear and nonlinear resistive force theory.

PubMed

Keaveny, Eric E; Brown, André E X

2017-03-22

A basic issue in the physics of behaviour is the mechanical relationship between an animal and its surroundings. The model nematode C. elegans provides an excellent platform to explore this relationship due to its anatomical simplicity. Nonetheless, the physics of nematode crawling, in which the worm undulates its body to move on a wet surface, is not completely understood and the mathematical models often used to describe this phenomenon are empirical. We confirm that linear resistive force theory, one such empirical model, is effective at predicting a worm's path from its sequence of body postures for forward crawling, reversing, and turning and for a broad range of different behavioural phenotypes observed in mutant worms. Worms recently isolated from the wild have a higher effective drag anisotropy than the laboratory-adapted strain N2 and most mutant strains. This means the wild isolates crawl with less surface slip, perhaps reflecting more efficient gaits. The drag anisotropies required to fit the observed locomotion data (70  ±  28 for the wild isolates) are significantly larger than the values measured by directly dragging worms along agar surfaces (3-10 in Rabets et al (2014 Biophys. J. 107 1980-7)). A proposed nonlinear extension of the resistive force theory model also provides accurate predictions, but does not resolve the discrepancy between the parameters required to achieve good path prediction and the experimentally measured parameters. We confirm that linear resistive force theory provides a good effective model of worm crawling that can be used in applications such as whole-animal simulations and advanced tracking algorithms, but that the nature of the physical interaction between worms and their most commonly studied laboratory substrate remains unresolved.

Study of the Feasibility of Using an Advanced Opto-Electronic Imaging Technique for Sampling Mid-Water Nekton.

DTIC Science & Technology

1978-11-30

migration(diurnal) of Mycophidae and siphonophores of the suborder Physonectae. —2— _______ - ~~~~~~~~~~ _____________________________ I-~ The former...ORGANISMS PLANKTON COPEPODS TRANSLUCENT ! ARROW WORMS TRANSPARENT SIPHONOPHORES MEDUSAE AGLISCRA IGNEA FLAMING RED NEMERTEAN WORMS REDDISH ARROW WORMS...383-385 ( 1969) 9. BARHAN, Eric G., Siphonophores and the Deep Scattering Layer, Science, 140, 826—828 (1963) 10. BARHA~M , Eric C., Deep Scattering

Worm Grunting, Fiddling, and Charming—Humans Unknowingly Mimic a Predator to Harvest Bait

PubMed Central

Catania, Kenneth C.

2008-01-01

Background For generations many families in and around Florida's Apalachicola National Forest have supported themselves by collecting the large endemic earthworms (Diplocardia mississippiensis). This is accomplished by vibrating a wooden stake driven into the soil, a practice called “worm grunting”. In response to the vibrations, worms emerge to the surface where thousands can be gathered in a few hours. Why do these earthworms suddenly exit their burrows in response to vibrations, exposing themselves to predation? Principal Findings Here it is shown that a population of eastern American moles (Scalopus aquaticus) inhabits the area where worms are collected and that earthworms have a pronounced escape response from moles consisting of rapidly exiting their burrows to flee across the soil surface. Recordings of vibrations generated by bait collectors and moles suggest that “worm grunters” unknowingly mimic digging moles. An alternative possibility, that worms interpret vibrations as rain and surface to avoid drowning is not supported. Conclusions Previous investigations have revealed that both wood turtles and herring gulls vibrate the ground to elicit earthworm escapes, indicating that a range of predators may exploit the predator-prey relationship between earthworms and moles. In addition to revealing a novel escape response that may be widespread among soil fauna, the results show that humans have played the role of “rare predators” in exploiting the consequences of a sensory arms race. PMID:18852902

Distribution and movement of Caenorhabditis elegans on a thermal gradient.

PubMed

Yamada, Yohko; Ohshima, Yasumi

2003-08-01

To analyze thermal responses of Caenorhabditis elegans in detail, distribution of a worm population and movement of individual worms were examined on a linear, reproducible and broad temperature gradient. Assay methods were improved compared with those reported previously to ensure good motility and dispersion of worms. Well-fed, wild-type worms distributed over a wide temperature range of up to 10 degrees C, and, within this range, worms migrated in both directions of the gradient at similar frequencies without any specific response to the growth temperature in most cases. By contrast, worms migrated down the gradient if put in a region warmer than the warm boundary of distribution. The distribution range changed depending on the growth temperature and starvation, but active avoidance of a starvation temperature was not detected. These findings contradict previous hypotheses of taxis or migration to the growth temperature in association with food and instead indicate avoidance of a warm temperature. Our results favor a model for thermal response of C. elegans that postulates a single drive based on warm sensation rather than downward and upward drives in the physiological temperature range. Mutants in ttx-3, tax-2, tax-4 or egl-4 genes showed abnormal thermal responses, suggesting that these genes are involved in warm avoidance. Laser ablation and gene expression studies suggest that AFD neurons are not important, and tax-4 expression in neurons other than AFD is required, for warm avoidance.

Identification of Fasciola species based on mitochondrial and nuclear DNA reveals the co-existence of intermediate Fasciola and Fasciola gigantica in Thailand.

PubMed

Wannasan, Anchalee; Khositharattanakool, Pathamet; Chaiwong, Prasong; Piangjai, Somsak; Uparanukraw, Pichart; Morakote, Nimit

2014-11-01

Molecular techniques were used to identify Fasciola species collected from Chiang Mai Thailand. Morphometrically, 65 stained and 45 fresh worms collected from cattle suggested the possible occurrence of both F. gigantica and F. hepatica. Twenty-two worms comprising 15 from cattle and 7 from human patients, were identified subsequently based on three genetic markers: mitochondrial nicotinamide adenine dinucleotide dehydrogenase subunit 1 (nad1), mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear ribosomal internal transcribed spacer 2 (ITS2). All of them presented the F. gigantica type in maternally inherited mitochondrial sequences (nad1 and cox1), with six types in each sequence (FgNDI-CM1 to FgNDI-CM6 and FgCOI-CM1 to FgCOI-CM6, respectively). Remarkably, the predominant nad1 type, FgNDI-CM6, was identical to that of aspermic Fasciola sp. formerly reported from Thailand, Japan, Korea, China, Vietnam, and Myanmar. ITS2 sequences were analyzed successfully in 20 worms. Fifteen worms showed the F. gigantica type and five (including one worm from a patient) had mixed ITS2 sequences of both F. gigantica and F. hepatica in the same worms, with additional heterogeneity within both ITS2 types. This study revealed the intermediate form of Fasciola coexisting with F. gigantica for the first time in Thailand.

Praziquantel

MedlinePlus

... used to treat certain other worm infestations, including tapeworm (a type of worm that may attach to ... have ocular cysticercosis (infestation with a type of tapeworm that forms cysts in the eyes). Your doctor ...

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...

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...

The effect of cohabitation of Tubifex tubifex (Oligochaeta: Tubificidae) populations on infections to Myxobolus cerebralis (Myxozoa: Myxobolidae).

PubMed

Beauchamp, Katherine A; El-Matbouli, Mansour; Gay, Melanie; Georgiadis, Marios P; Nehring, R Barry; Hedrick, Ronald P

2006-01-01

The competitive interactions between susceptible and resistant Tubifex tubifex (Oligochaeta: Tubificidae) exposed to Myxobolus cerebralis (Myxozoa: Myxobolidae) infections were investigated in two laboratory trials. Competition was assessed by the total parasite production over the course of the trials in mixed and pure cultures of M. cerebralis exposed worms, and by the genetic analyses of worms from the control and experimental groups at the beginning and end of the experiments. Mixed cultures of resistant and susceptible worms showed a 70% reduction in production of parasites released when compared with pure cultures of susceptible worms. In studies with laboratory and field-collected oligochaetes the mixed cultures at the end of the cohabitation experiments were dominated by resistant Tubifex from lineage V (HB strain) this strain of Tubifex has a competitive advantage over worms from other lineages. The results of this study suggest that certain species of Tubifex may be dead-end hosts to M. cerebralis by absorbing or inactivating the parasite and may also show greater survival compared to susceptible oligochaetes in certain whirling disease enzootic habitats.

Annual Survey of Horsehair Worm Cysts in Northern Taiwan, with Notes on a Single Seasonal Infection Peak in Chironomid Larvae (Diptera: Chironomidae).

PubMed

Chiu, Ming-Chung; Huang, Chin-Gi; Wu, Wen-Jer; Shiao, Shiuh-Feng

2016-06-01

The life cycle of the freshwater horsehair worm typically includes a free-living phase (adult, egg, larva) and a multiple-host parasitic phase (aquatic paratenic host, terrestrial definitive host). Such a life cycle involving water and land can improve energy flow in riparian ecosystems; however, its temporal dynamics in nature have rarely been investigated. This study examined seasonal infection with cysts in larval Chironominae (Diptera: Chironomidae) in northern Taiwan. In the larval chironomids, cysts of 3 horsehair worm species were identified. The cysts of the dominant species were morphologically similar to those of Chordodes formosanus. Infection with these cysts increased suddenly and peaked 2 mo after the reproductive season of the adult horsehair worms. Although adult C. formosanus emerged several times in a year, only 1 distinct infection peak was detected in September in the chironomid larvae. Compared with the subfamily Chironominae, samples from the subfamilies Tanypodinae and Orthocladiinae were less parasitized. This indicates that the feeding behavior of the chironomid host likely affects horsehair worm cyst infections; however, bioconcentration in predatory chironomids was not detected.

Influence of temperature and substrate on infection rate, triactinomyxon production, and release duration from eastern tubifex worms infected with Myxobolus cerebralis

USGS Publications Warehouse

Waldrop, Thomas; Blazer, Vicki; Smith, David; Schill, Bane; Densmore, Christine; Schill, B.; Waldrop, T.; Blazer, V.

1999-01-01

Salmonid whirling disease is caused by Myxobolus cerebralis, a metazoan parasite with a two host life cycle involving salmonid fish a an aquatic oligochaete, Tubifex tubifex (Wolf, Markiw and Hiltunen, 1986). Whirling disease has been reported in 22 U.S. states with the greatest losses occurring in the salmonid fisheries of western and Midwestern states. Although whirling disease is endemic in the eastern United States, serious documented losses to wild populations have not been reported. Two high priority research needs identified in 1996 were a better understanding of how worm and parasite populations might differ from different geographic areas and how environmental factors affect the various stages of whirling disease. To begin to address these research needs we established "eastern" populations of worms, parasite and fish hosts. This abstract will present data on the effects of temperature and substrate upon eastern T. tubifex worms infected with an eastern isolate of M. cerebralis. The influences of these abiotic factors upon the ability to infect the worms and subsequently their ability to produce waterborne triactinomyxons.

WormBase 2014: new views of curated biology

PubMed Central

Harris, Todd W.; Baran, Joachim; Bieri, Tamberlyn; Cabunoc, Abigail; Chan, Juancarlos; Chen, Wen J.; Davis, Paul; Done, James; Grove, Christian; Howe, Kevin; Kishore, Ranjana; Lee, Raymond; Li, Yuling; Muller, Hans-Michael; Nakamura, Cecilia; Ozersky, Philip; Paulini, Michael; Raciti, Daniela; Schindelman, Gary; Tuli, Mary Ann; Auken, Kimberly Van; Wang, Daniel; Wang, Xiaodong; Williams, Gary; Wong, J. D.; Yook, Karen; Schedl, Tim; Hodgkin, Jonathan; Berriman, Matthew; Kersey, Paul; Spieth, John; Stein, Lincoln; Sternberg, Paul W.

2014-01-01

WormBase (http://www.wormbase.org/) is a highly curated resource dedicated to supporting research using the model organism Caenorhabditis elegans. With an electronic history predating the World Wide Web, WormBase contains information ranging from the sequence and phenotype of individual alleles to genome-wide studies generated using next-generation sequencing technologies. In recent years, we have expanded the contents to include data on additional nematodes of agricultural and medical significance, bringing the knowledge of C. elegans to bear on these systems and providing support for underserved research communities. Manual curation of the primary literature remains a central focus of the WormBase project, providing users with reliable, up-to-date and highly cross-linked information. In this update, we describe efforts to organize the original atomized and highly contextualized curated data into integrated syntheses of discrete biological topics. Next, we discuss our experiences coping with the vast increase in available genome sequences made possible through next-generation sequencing platforms. Finally, we describe some of the features and tools of the new WormBase Web site that help users better find and explore data of interest. PMID:24194605

The opportunistic transmission of wireless worms between mobile devices

NASA Astrophysics Data System (ADS)

Rhodes, C. J.; Nekovee, M.

2008-12-01

The ubiquity of portable wireless-enabled computing and communications devices has stimulated the emergence of malicious codes (wireless worms) that are capable of spreading between spatially proximal devices. The potential exists for worms to be opportunistically transmitted between devices as they move around, so human mobility patterns will have an impact on epidemic spread. The scenario we address in this paper is proximity attacks from fleetingly in-contact wireless devices with short-range communication range, such as Bluetooth-enabled smart phones. An individual-based model of mobile devices is introduced and the effect of population characteristics and device behaviour on the outbreak dynamics is investigated. The model uses straight-line motion to achieve population, though it is recognised that this is a highly simplified representation of human mobility patterns. We show that the contact rate can be derived from the underlying mobility model and, through extensive simulation, that mass-action epidemic models remain applicable to worm spreading in the low density regime studied here. The model gives useful analytical expressions against which more refined simulations of worm spread can be developed and tested.

Effects of experimental otter trawling on benthic assemblages on Western Bank, northwest Atlantic Ocean

NASA Astrophysics Data System (ADS)

Kenchington, Ellen L. R.; Gilkinson, Kent D.; MacIsaac, Kevin G.; Bourbonnais-Boyce, Cynthia; Kenchington, Trevor J.; Smith, Stephen J.; Gordon, Donald C., Jr.

2006-10-01

The effects of otter trawling on a hard-bottom ecosystem on Western Bank on Canada's Scotian Shelf were examined experimentally from 1997 to 1999 with an asymmetrical BACI design. The site was located within an area that had been closed to fishing since 1987 to protect juvenile haddock. An experimental line was trawled 12-14 times on three separate occasions over a 20 month period. The benthic macrofauna and megafauna were sampled before and after trawling on both impact and control lines with both a grab and a photographic system. The 100 grab samples collected contained 341 taxa, primarily polychaetes, amphipods and molluscs, the majority (60%) of which were epifaunal. Biomass was dominated by the horse-mussel Modiolus modiolus, a long-lived bivalve, while the tube-building amphipod Ericthonius fasciatus was the most abundant species. Through the study period the benthos on the control lines showed little qualitative or quantitative change in individual taxa or community metrics. However, the abundance of 24 individual taxa (polychaetes, amphipods, echinoderms and molluscs) changed significantly, with the majority of these increasing. This resulted in a significantly different relative abundance of taxa between years as detected through ANOSIM. A significant change in relative biomass amongst the taxa was also observed. Trawling had few detectable immediate effects on the abundance or biomass of individual taxa and none on community composition. A few taxa, primarily a mixture of polychaetes and amphipods, decreased significantly after trawling and data from fish stomachs collected during the experiment (Kenchington, E.L., Gordon Jr., D.C., Bourbonnais-Boyce, C., MacIsaac, K.G., Gilkinson, K.D., McKeown, D.L., Vass, W.P., 2005. Effects of experimental otter trawling on the feeding of demersal fish on Western Bank, Nova Scotia. Amer. Fish. Soc. Symp. 41, 391-409) showed that some of these were scavenged by demersal fish. Fifteen taxa showed significant decreases after trawling when the cumulative effects of trawling were considered. As in the analyses of individual years the species affected were primarily high turn-over species such as polychaetes and amphipods. Dominance curves prepared for both control and impact samples before trawling in 1997 and after trawling in 1999 showed a marked decrease in the biomass values of the highest ranking taxa, particularly of the first species, M. modiolus, only on the impact line at the conclusion of the experiment. The proportion of epifaunal biomass also declined significantly from 90% to 77% on the impact line by the conclusion of the experiment. These changes are in part due to trawl-induced damage and subsequent predation by demersal fish of the top ranking species. Analysis of the photographic images showed that the three top-ranking species in terms of biomass, M. modiolus, the tube-building polychaete Thelepus cincinnatus, and the brachiopod Terebratulina septentrionalis, were visibly damaged more than other species by the trawl gear. Two of these species, M. modiolus and T. cincinnatus, were preyed upon by scavenging demersal fish. The use of multiple sampling devices at the experimental site (grab, photographic system reported here and trawl and fish stomachs reported by Kenchington, E.L., Gordon Jr., D.C., Bourbonnais-Boyce, C., MacIsaac, K.G., Gilkinson, K.D., McKeown, D.L., Vass, W.P., 2005. Effects of experimental otter trawling on the feeding of demersal fish on Western Bank, Nova Scotia. Amer. Fish. Soc. Symp. 41, 391-409) enabled us to link trawl-induced changes to the benthos to predation by demersal fish.

OpenWorm: an open-science approach to modeling Caenorhabditis elegans.

PubMed

Szigeti, Balázs; Gleeson, Padraig; Vella, Michael; Khayrulin, Sergey; Palyanov, Andrey; Hokanson, Jim; Currie, Michael; Cantarelli, Matteo; Idili, Giovanni; Larson, Stephen

2014-01-01

OpenWorm is an international collaboration with the aim of understanding how the behavior of Caenorhabditis elegans (C. elegans) emerges from its underlying physiological processes. The project has developed a modular simulation engine to create computational models of the worm. The modularity of the engine makes it possible to easily modify the model, incorporate new experimental data and test hypotheses. The modeling framework incorporates both biophysical neuronal simulations and a novel fluid-dynamics-based soft-tissue simulation for physical environment-body interactions. The project's open-science approach is aimed at overcoming the difficulties of integrative modeling within a traditional academic environment. In this article the rationale is presented for creating the OpenWorm collaboration, the tools and resources developed thus far are outlined and the unique challenges associated with the project are discussed.

Emulation of the Active Immune Response in a Computer Network

DTIC Science & Technology

2009-01-15

the Code Red worm propagated faster than the Melissa virus in 1999 and much faster than Morris’ worm in 1988. In the case of the Code Red worm, only...report to AFRL on contract #30602-01-0509, Binghamton NY, 2002, 2. Skormin, V.A., Delgado-Frias, J.G., McGee, D.L., Giordano , J.V., Popyack, L.J...V., Delgado-Frias J., McGee D., Giordano J., Popyack L.. Tarakanov A., "BASIS: A Biological Approach to System Information Security," ^2

Human Gongylonema pulchrum Infection: Esophageal Symptoms and Need for Prolonged Albendazole Therapy.

PubMed

Libertin, Claudia R; Reza, Mohammed; Peterson, Joy H; Lewis, Jason; Hata, D Jane

2017-04-01

AbstractWe describe a case of human infection with Gongylonema pulchrum acquired in southeast Georgia. The patient presented with intermittent yet persistent nausea and vomiting for months. This case describes the need for extraction of worms on two occasions each followed by courses of albendazole treatment. Gongylonema pulchrum infections with high worm burden may relapse after extraction of the worm and a 3-day short course of albendazole therapy. Longer courses of albendazole may be indicated in selected circumstances.

Hydrolytic degradation of poly(ethylene oxide)-block-polycaprolactone worm micelles.

PubMed

Geng, Yan; Discher, Dennis E

2005-09-21

Spherical micelles and nanoparticles made with degradable polymers have been of great interest for therapeutic application, but degradation-induced changes in a spherical morphology can be subtle and mechanism/kinetics appears poorly understood. Here, we report the first preparation of giant and flexible worm micelles self-assembled from degradable copolymer poly(ethylene oxide)-block-polycaprolactone. Such worm micelles spontaneously shorten to generate spherical micelles, triggered by polycaprolactone hydrolysis, with distinct mechanism and kinetics from that which occurs in bulk material.

7 CFR 51.3145 - U.S. Fancy.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., broken skins which are not healed, worms, worm holes, and free from injury caused by bruises, growth cracks, hail, sunburn, sprayburn, scab, bacterial spot, scale, split pit, scars, russeting, other disease...

7 CFR 51.3145 - U.S. Fancy.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., broken skins which are not healed, worms, worm holes, and free from injury caused by bruises, growth cracks, hail, sunburn, sprayburn, scab, bacterial spot, scale, split pit, scars, russeting, other disease...

7 CFR 51.3145 - U.S. Fancy.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., broken skins which are not healed, worms, worm holes, and free from injury caused by bruises, growth cracks, hail, sunburn, sprayburn, scab, bacterial spot, scale, split pit, scars, russeting, other disease...

Elicitation of dopaminergic features of Parkinson's disease in C. elegans by monocrotophos, an organophosphorous insecticide.

PubMed

Ali, Shaheen Jafri; Rajini, Padmanabhan Sharda

2012-12-01

Positive correlations have been suggested between usage of pesticides and the incidence of Parkinson's disease (PD) through epidemiological as well as few experimental evidences. Organophosphorus insecticides (OPI), which are extensively used in agricultural and household insect control, have been the subject of increasing concern in the past decades due to their neurotoxic potential. However, very few studies have demonstrated the potentials of OPI to induce features of PD in model organisms. In the present study, Caenorhabditis elegans was selected as the model organism to evaluate the potential of monocrotophos (MCP), an OPI, to elicit dopaminergic features of Parkinson's disease in terms of dopamine content, basic movement and integrity of dopaminergic neurons along with its effect on acetylcholinesterase (AChE) activity and life span. All the responses elicited by MCP were compared with that elicited by 1-methyl-4-phenyl- 1, 2, 3, 6-tetrahydropyridine (MPTP) in both N2 and BZ555 worms. N2 worms were exposed to varying concentrations of MCP (50, 100 and 200 μM) or MPTP (200, 300 and 400 μM) for 48 hours and locomotory rate, as measured by the number of body bends made in 20 seconds, was enumerated. Worms subjected to the same dose paradigms were also analyzed for the dopamine content by HPLC. The results indicated a significant reduction in the dopamine levels in the worms that were treated with MCP/MPTP and this correlated with the changes in locomotion compared to untreated worms. Worms treated with MCP also exhibited significant reduction in AChE activity. Both MPTP and MCP caused a marked reduction in life span in the worms. Transgenic worms (BZ555, which has GFP tagged to its 8 dopaminergic neurons) exposed to MCP and MPTP at the above concentrations showed a dose-dependent reduction in the number of green pixels in CEP and ADE neurons which also correlated with the neurodegeneration as visualized by decreased fluorescence in photomicrographs. Taken together, our data demonstrate that low levels of MCP elicits dopaminergic features of PD in C. elegans.

Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto regional water quality control plant in south San Francisco Bay, California: 2005

USGS Publications Warehouse

Cain, Daniel J.; Parcheso, Francis; Thompson, Janet K.; Luoma, Samuel N.; Lorenzi, Allison H.; Moon, Edward; Shouse, Michelle K.; Hornberger, Michelle I.; Dyke, Jessica

2006-01-01

Trace elements in sediment and the clam Macoma petalum (formerly reported as Macoma balthica (Cohen and Carlton 1995), clam reproductive activity and benthic, macroinvertebrate community structure are reported for a mudflat one kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant in South San Francisco Bay. This report includes data collected for the period January to December 2005, and extends a critical long-term biogeochemical record dating back to 1974. These data serve as the basis for the City of Palo Alto's Near-Field Receiving Water Monitoring Program, initiated in 1994. Metal concentrations in both sediments and clam tissue during 2005 were consistent with results observed since 1990. Copper and zinc concentrations in sediment and bivalve tissue displayed a continued decrease over the last decade. In 2005, Cu concentrations were at or below the effects range-low (ERL) concentration (34 ?g/g) for the entire year, the first time this has been observed. Also, zinc concentrations never exceeded the ERL (150 ?g/g). Yearly average concentrations of copper, zinc and silver in Macoma petalum for 2005 were some of the lowest recorded since monitoring for metals began in 1975. The concentrations of mercury and selenium in sediments, during April and January 2004, respectively, were the highest values observed for these elements during this study. Later in 2005, concentrations decreased to historic levels. The increase in mercury and selenium in 2004 was not a permanent trend and concentrations of these elements in sediments and clams at Palo Alto remain similar to concentrations observed elsewhere in the San Francisco Bay. Analyses of the benthic-community structure of a mudflat in South San Francisco Bay over a 31-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinal clam Macoma petalum from the same area. Analysis of the reproductive activity of M. petalum shows increases in reproductive activity concurrent with the decline in metal concentrations in the tissues of this organism. Reproductive activity is presently stable with almost all animals initiating reproduction in the fall and spawning the following spring of most years. The community has shifted from being dominated by several opportunistic species to a community where the species are more similar in abundance, a pattern that suggests a more stable community that is subjected to less stress. In addition, two of the opportunistic species (Ampelisca abdita and Streblospio benedicti) that brood their young and live on the surface of the sediment in tubes have shown a continual decline in dominance coincident with the decline in metals. Heteromastus filiformis, a subsurface polychaete worm that lives in the sediment, consumes sediment and organic particles residing in the sediment, and reproduces by laying their eggs on or in the sediment has shown a concurrent increase in dominance. These changes in species dominance reflect a change in the community from one dominated by surface dwelling, brooding species to one with species with varying life history characteristics. For the first time since its invasion in 1986, the non-indigenous filter-feeding bivalve Corbula (Potamocorbula) amurensis has shown up in small but persistent numbers in the benthic community.

21 CFR 520.1198 - Ivermectin and praziquantel paste.

Code of Federal Regulations, 2014 CFR

2014-04-01

...; Large-mouth Stomach Worms (adults)—Habronema muscae; Bots (oral and gastric stages)—Gasterophilus spp...; Hairworms (adults)—Trichostrongylus axei; Large-mouth Stomach Worms (adults)—Habronema muscae; Bots (oral...

21 CFR 520.1198 - Ivermectin and praziquantel paste.

Code of Federal Regulations, 2013 CFR

2013-04-01

...; Large-mouth Stomach Worms (adults)—Habronema muscae; Bots (oral and gastric stages)—Gasterophilus spp...; Hairworms (adults)—Trichostrongylus axei; Large-mouth Stomach Worms (adults)—Habronema muscae; Bots (oral...

7 CFR 51.3148 - U.S. No. 2.

Code of Federal Regulations, 2010 CFR

2010-01-01

... from decay, broken skins which are not healed, worms, worm holes, and free from serious damage caused by bruises, growth cracks, hail, sunburn, sprayburn, scab, bacterial spot, scale, split pit, scars...

7 CFR 51.1346 - U.S. No. 1.

Code of Federal Regulations, 2010 CFR

2010-01-01

... which are mature, handpicked, firm, well formed, free from scald, hard end, black end, internal breakdown, decay, worms and worm holes, and from damage caused by broken skins, limbrubs, sprayburn, sunburn...

7 CFR 51.1346 - U.S. No. 1.

Code of Federal Regulations, 2011 CFR

2011-01-01

... which are mature, handpicked, firm, well formed, free from scald, hard end, black end, internal breakdown, decay, worms and worm holes, and from damage caused by broken skins, limbrubs, sprayburn, sunburn...

7 CFR 51.1280 - Serious damage.

Code of Federal Regulations, 2014 CFR

2014-01-01

... shall be considered under the definition of russeting. (5) Insects: (i) Worm holes. More than three... worm injury which affects an aggregate area of more than three-fourths inch in diameter or which...

7 CFR 51.1280 - Serious damage.

Code of Federal Regulations, 2013 CFR

2013-01-01

... shall be considered under the definition of russeting. (5) Insects: (i) Worm holes. More than three... worm injury which affects an aggregate area of more than three-fourths inch in diameter or which...

7 CFR 51.1323 - Serious damage.

Code of Federal Regulations, 2012 CFR

2012-01-01

... under the definition of russeting. (7) Insects: (i) Worm holes. More than three healed codling moth... insect stings affecting the appearance to an equal extent. 2 (ii) Blister mite or canker worm injury...

7 CFR 51.1346 - U.S. No. 1.

Code of Federal Regulations, 2012 CFR

2012-01-01

... which are mature, handpicked, firm, well formed, free from scald, hard end, black end, internal breakdown, decay, worms and worm holes, and from damage caused by broken skins, limbrubs, sprayburn, sunburn...

21 CFR 520.1198 - Ivermectin and praziquantel paste.

Code of Federal Regulations, 2011 CFR

2011-04-01

...; Large-mouth Stomach Worms (adults)—Habronema muscae; Bots (oral and gastric stages)—Gasterophilus spp...; Hairworms (adults)—Trichostrongylus axei; Large-mouth Stomach Worms (adults)—Habronema muscae; Bots (oral...

7 CFR 51.3147 - U.S. No. 1.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., broken skins which are not healed, worms, worm holes, and free from injury caused by split pit and free from damage caused by bruises, growth cracks, hail, sunburn, sprayburn, scab, bacterial spot, scale...

7 CFR 51.1347 - U.S. No. 2.

Code of Federal Regulations, 2011 CFR

2011-01-01

... which are mature, handpicked, firm, not seriously deformed, free from scald, hard end, black end, internal breakdown, decay, worms and worm holes, and free from serious damage by any other cause. Unless...

7 CFR 51.1347 - U.S. No. 2.

Code of Federal Regulations, 2010 CFR

2010-01-01

... which are mature, handpicked, firm, not seriously deformed, free from scald, hard end, black end, internal breakdown, decay, worms and worm holes, and free from serious damage by any other cause. Unless...

7 CFR 51.3148 - U.S. No. 2.

Code of Federal Regulations, 2014 CFR

2014-01-01

... badly misshapen, which are clean and free from decay, broken skins which are not healed, worms, worm holes, and free from serious damage caused by bruises, growth cracks, hail, sunburn, sprayburn, scab...

7 CFR 51.3148 - U.S. No. 2.

Code of Federal Regulations, 2013 CFR

2013-01-01

... badly misshapen, which are clean and free from decay, broken skins which are not healed, worms, worm holes, and free from serious damage caused by bruises, growth cracks, hail, sunburn, sprayburn, scab...

7 CFR 51.1347 - U.S. No. 2.

Code of Federal Regulations, 2012 CFR

2012-01-01

... which are mature, handpicked, firm, not seriously deformed, free from scald, hard end, black end, internal breakdown, decay, worms and worm holes, and free from serious damage by any other cause. Unless...

Preliminary effects of water hardness on triactinomyxon production and development from eastern tubifex worms infected with Myxobolus cerebralis

USGS Publications Warehouse

Waldrop, Thomas B.; Densmore, Christine; Blazer, Vicki; Smith, Dave; Schill, Bane; Schill, B.; Waldrop, T.; Blazer, V.

1999-01-01

Whirling disease is caused by Myxobolus cerebralis and requires an intermediate oligochaete host identified as Tubifex tubifex (Wolf, Markiw, and Hiltunen, 1986). M. cerebralis spores ingested by the tubifex worms develop into triactinomyxons (tams) that are eventually released into the water column to infect salmonid fish. There may be many environmental parameters, biotic or abiotic, that may affect the development of waterborne tams in eastern tubifex worms. This study will focus on one of those environmental parameters, total water hardness. Total water hardness is defined as the concentration of calcium and magnesium in a water sample expressed in milligrams per liter of equivalent CACO3 (Boyd, 1990). This study will address whether different levels of water hardness affect the development and production of tams released by infected tubifex worms.

Understanding Human-Plasmodium falciparum Immune Interactions Uncovers the Immunological Role of Worms

PubMed Central

Roussilhon, Christian; Brasseur, Philippe; Agnamey, Patrice; Pérignon, Jean-Louis; Druilhe, Pierre

2010-01-01

Background Former studies have pointed to a monocyte-dependant effect of antibodies in protection against malaria and thereby to cytophilic antibodies IgG1 and IgG3, which trigger monocyte receptors. Field investigations have further documented that a switch from non-cytophilic to cytophilic classes of antimalarial antibodies was associated with protection. The hypothesis that the non-cytophilic isotype imbalance could be related to concomittant helminthic infections was supported by several interventions and case-control studies. Methods and Findings We investigated here the hypothesis that the delayed acquisition of immunity to malaria could be related to a worm-induced Th2 drive on antimalarial immune responses. IgG1 to IgG4 responses against 6 different parasite-derived antigens were analyzed in sera from 203 Senegalese children, half carrying intestinal worms, presenting 421 clinical malaria attacks over 51 months. Results show a significant correlation between the occurrence of malaria attacks, worm carriage (particularly that of hookworms) and a decrease in cytophilic IgG1 and IgG3 responses and an increase in non-cytophilic IgG4 response to the merozoite stage protein 3 (MSP3) vaccine candidate. Conclusion The results confirm the association with protection of anti-MSP3 cytophilic responses, confirm in one additional setting that worms increase malaria morbidity and show a Th2 worm-driven pattern of anti-malarial immune responses. They document why large anthelminthic mass treatments may be worth being assessed as malaria control policies. PMID:20174576

Comparative pattern of growth and development of Echinostoma paraensei (Digenea: Echinostomatidae) in hamster and Wistar rat using light and confocal laser scanning microscopy.

PubMed

Souza, Joyce G R; Garcia, Juberlan S; Gomes, Ana Paula N; Machado-Silva, José Roberto; Maldonado, Arnaldo

2017-12-01

Echinostoma paraensei (Digenea: Echinostomatidae) lives in the duodenum and bile duct of rodents and is reported as a useful model for studies on the biology of flatworms. Here, we compared the growth and development of pre and post ovigerous worms collected 3, 7, 14 and 21 days post infection from experimentally infected hamster (permissive host) and Wistar rat (less permissive hosts). Linear measurements and ratios were examined by light (morphology and morphometry) and confocal laser scanning microscopy. At day 3, either worm from hamsters or rats were small with poorly developed gonads. At seven day, worms increased in size and morphometric differences between hosts are statistically significant after this time. In addition, adult worms (14 and 21 days of age) harvested from hamster showed developed gonads and vitelline glands laterally distributed on the body, whereas worms from rat showed atrophied reproductive system characterized by underdeveloped vitelline glands and stunted ovary. The worm rate recovery in rat decreased from 29.3% (day 7) to 20.6% (day 14) and 8% (day 21), whilst it remained around 37% in hamster. In conclusion, this is the first appointment demonstrating that low permissiveness influences the reproductive system of echinostome since the immature stages of development. The phenotypic analysis evidenced that hamster provides a more favorable microenvironment for gonads development than rat, confirming golden hamster as a permissive host, whereas Wistar rat is less permissive host. Copyright © 2017 Elsevier Inc. All rights reserved.

Mechanistic insights for block copolymer morphologies: how do worms form vesicles?

PubMed

Blanazs, Adam; Madsen, Jeppe; Battaglia, Giuseppe; Ryan, Anthony J; Armes, Steven P

2011-10-19

Amphiphilic diblock copolymers composed of two covalently linked, chemically distinct chains can be considered to be biological mimics of cell membrane-forming lipid molecules, but with typically more than an order of magnitude increase in molecular weight. These macromolecular amphiphiles are known to form a wide range of nanostructures (spheres, worms, vesicles, etc.) in solvents that are selective for one of the blocks. However, such self-assembly is usually limited to dilute copolymer solutions (<1%), which is a significant disadvantage for potential commercial applications such as drug delivery and coatings. In principle, this problem can be circumvented by polymerization-induced block copolymer self-assembly. Here we detail the synthesis and subsequent in situ self-assembly of amphiphilic AB diblock copolymers in a one pot concentrated aqueous dispersion polymerization formulation. We show that spherical micelles, wormlike micelles, and vesicles can be predictably and efficiently obtained (within 2 h of polymerization, >99% monomer conversion) at relatively high solids in purely aqueous solution. Furthermore, careful monitoring of the in situ polymerization by transmission electron microscopy reveals various novel intermediate structures (including branched worms, partially coalesced worms, nascent bilayers, "octopi", "jellyfish", and finally pure vesicles) that provide important mechanistic insights regarding the evolution of the particle morphology during the sphere-to-worm and worm-to-vesicle transitions. This environmentally benign approach (which involves no toxic solvents, is conducted at relatively high solids, and requires no additional processing) is readily amenable to industrial scale-up, since it is based on commercially available starting materials.

The effects of worms, clay and biochar on CO2 emissions during production and soil application of co-composts

NASA Astrophysics Data System (ADS)

Barthod, Justine; Rumpel, Cornélia; Paradelo, Remigio; Dignac, Marie-France

2016-12-01

In this study we evaluated CO2 emissions during composting of green wastes with clay and/or biochar in the presence and absence of worms (species of the genus Eisenia), as well as the effect of those amendments on carbon mineralization after application to soil. We added two different doses of clay, biochar or their mixture to pre-composted green wastes and monitored carbon mineralization over 21 days in the absence or presence of worms. The resulting co-composts and vermicomposts were then added to a loamy Cambisol and the CO2 emissions were monitored over 30 days in a laboratory incubation. Our results indicated that the addition of clay or clay/biochar mixture reduced carbon mineralization during co-composting without worms by up to 44 %. In the presence of worms, CO2 emissions during composting increased for all treatments except for the low clay dose. The effect of the amendments on carbon mineralization after addition to soil was small in the short term. Overall, composts increased OM mineralization, whereas vermicomposts had no effect. The presence of biochar reduced OM mineralization in soil with respect to compost and vermicompost without additives, whereas clay reduced mineralization only in the composts. Our study indicates a significant role of the conditions of composting on mineralization in soil. Therefore, the production of a low CO2 emission amendment requires optimization of feedstocks, co-composting agents and worm species.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meharg, A.A.; Shore, R.F.; Broadgate, K.

The toxicity and accumulation of arsenate was determined in the earthworm Lumbricus terrestris in soil from different layers of a forest profile. Toxicity increased fourfold between 2 and 10 d. Edaphic factors (pH, soil organic matter, and depth in soil profile) also affected toxicity with a three fold decrease in the concentration that causes 50% mortality with increasing depth in soil. In a 4-d exposure study, there was no evidence of arsenic bioconcentration in earthworm tissue, although bioaccumulation was occurring. There was a considerable difference in tissue residues between living and dead earthworms, with dead worms having higher concentrations. Thismore » difference was dependent on both soil arsenate concentration and on soil type. Over a wide range of soil arsenate concentrations, earthworm arsenic residues are homeostatically maintained in living worms, but this homeostasis breaks down during death. Alternatively, equilibration with soil residues may occur via accumulation after death. In long-term accumulation studies in soils dosed with a sublethal arsenate concentration, bioconcentration of arsenate did not occur until day 12, after which earthworm concentrations rose steadily above the soil concentration, with residues in worms three fold higher than soil concentrations by the termination of the study. This bioconcentration only occurred in depurated worms over the time period of the study. Initially, depurated worms had lower arsenic concentrations than undepurated until tissue concentrations were equivalent to the soil concentration. Once tissue concentration was greater than soil concentration, depurated worms had higher arsenic residues than undepurated.« less

Pyrosequencing of prey DNA in reptile faeces: analysis of earthworm consumption by slow worms.

PubMed

Brown, David S; Jarman, Simon N; Symondson, William O C

2012-03-01

Little quantitative ecological information exists on the diets of most invertebrate feeding reptiles, particularly nocturnal or elusive species that are difficult to observe. In the UK and elsewhere, reptiles are legally required to be relocated before land development can proceed, but without knowledge of their dietary requirements, the suitability of receptor sites cannot be known. Here, we tested the ability of non-invasive DNA-based molecular diagnostics (454 pyrosequencing) to analyse reptile diets, with the specific aims of determining which earthworm species are exploited by slow worms (the legless lizard Anguis fragilis) and whether they feed on the deeper-living earthworm species that only come to the surface at night. Slow worm faecal samples from four different habitats were analysed using earthworm-specific PCR primers. We found that 86% of slow worms (N=80) had eaten earthworms. In lowland heath and marshy/acid grassland, Lumbricus rubellus, a surface-dwelling epigeic species, dominated slow worm diet. In two other habitats, riverside pasture and calciferous coarse grassland, diet was dominated by deeper-living anecic and endogeic species. We conclude that all species of earthworm are exploited by these reptiles and lack of specialization allows slow worms to thrive in a wide variety of habitats. Pyrosequencing of prey DNA in faeces showed promise as a practical, rapid and relatively inexpensive means of obtaining detailed and valuable ecological information on the diets of reptiles. © 2011 Blackwell Publishing Ltd.

Human injuries and fatalities due to venomous marine snails of the family Conidae.

PubMed

Kohn, Alan J

2016-07-01

This paper provides the first compilation in more than 30 years of human injuries and fatalities from envenomation by marine gastropod molluscs of the predominantly tropical family Conidae. It seeks to apply recent advances in knowledge of the physiological effects of conopeptides and molecular genetics to improve our understanding of the human responses to stings by species that normally use their venom peptides to paralyze and overcome prey such as polychaete worms, other gastropod molluscs, and fishes. A database has been constructed for the 139 cases accepted as reliably reporting each human injury. It includes data on the species responsible, the time and place where the stinging occurred and the sting site on the victim's body, the time-course of clinical effects, treatment carried out, if any, and outcome. Members of the hyperdiverse genus Conus caused all the injuries, except for 2 cases involving species from the recently separated genus Conasprella. Death occurred in 36 cases, 57 cases presented with serious symptoms but recovered completely, and in 44 cases victims were only minimally affected. A few cases are listed as tentative because the information in the reports was limited or unverifiable. Many cases have undoubtedly gone unreported and been forgotten. No cases are known for the period between the date of the first reliable report in the 17th century, and the mid-19th century. Knowledge of conopeptide molecular structure and function has recently burgeoned, permitting initial exploration of relationships between the symptoms and outcomes of human injuries and modes of action of these mainly small, very toxic neuroactive peptides. These relationships are reviewed here, especially in regard to the severe and fatal cases, with the aim of making recent knowledge accessible to clinicians and others involved in treating the effects of human stings, which continue to be reported. Conus geographus, a specialized predator of fishes, which it paralyzes with its venom and swallows whole, is the most dangerous species to humans. It accounts for about half of the known human envenomations and almost all the fatalities. Children succumb more often to C. geographus stings than adults and stings by larger snails are lethal more often than stings from smaller snails, regardless of the victim's age. Other piscivorous Conus species have stung humans, but with nonlethal results. A few species that normally prey on other gastropods have also seriously injured humans, but most of the fatalities reported have not been confirmed. Most species of Conidae prey only on marine worms; 18 of these species are known to have stung humans, with generally mild effects. Research on the treatment of Conus stings has lagged behind that on the application of conopeptides in pharmacological research and in the development of new pharmaceuticals. However, improved communication and availability of medical aid in remote tropical areas has likely contributed to reducing the mortality rate during the last half century.

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...

Use of Computed Tomography Imaging for Qualifying Coarse Roots, Rhizomes, Peat, and Particle Densities in Marsh Soils

EPA Science Inventory

Computed tomography (CT) imaging has been used to describe and quantify subtidal, benthic animals such as polychaetes, amphipods, and shrimp. Here, for the first time, CT imaging is used to successfully quantify wet mass of coarse roots, rhizomes, and peat in cores collected from...

Microphthalmus mahensis sp.n. (Annelida, Phyllodocida) together with an annotated key of the genus

NASA Astrophysics Data System (ADS)

Westheide, Wilfried

2013-09-01

An interstitial polychaete, Microphthalmus mahensis, new species (Phyllodocida), is described from sand sediments of a coral reef flat of the Seychelles island Mahé. A comprehensive discussion includes a complete list of all 38 valid Microphthalmus species, and a key together with critical remarks on problematic species and subspecies.

Dredge Disposal Study. San Francisco Bay and Estuary. Appendix D. Biological Community

DTIC Science & Technology

1975-08-01

nematodes, oligochaetes, and the mollusc Adula diegensis were found in all four surveys. The nemerteans, three polychaetes (Hesionura sp., Medio ...balthica was studied in a nine-day laboratory experiment. One to three concentrations (2.5, 5, and 10 pg/liter above ambient ) and three salinities (5, 12.5

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. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of sedimentary sulfide on community structure, population dynamics, and colonization depth of macrozoobenthos in organic-rich estuarine sediments.

PubMed

Kanaya, Gen; Uehara, Tadayasu; Kikuchi, Eisuke

2016-08-15

An annual field survey and in situ recolonization experiment revealed the effects of sedimentary sulfide (H2S) on macrozoobenthos in a eutrophic brackish lagoon. Species diversity was much lower throughout the year in muddy opportunist-dominant sulfidic areas. Mass mortality occurred during warmer months under elevated H2S levels. An enclosure experiment demonstrated that sedimentary H2S modified community composition, size structure, and colonization depth of macrozoobenthos. Species-specific responses to each sediment type (sand, sulfidic mud, and mud with H2S removed) resulted in changes in the established community structure. Dominant polychaetes (Hediste spp., Pseudopolydora spp., and Capitella teleta) occurred predominantly in a thin surface layer in the presence of H2S. On the other hand, organic-rich mud facilitated settlement of polychaete larvae if it does not contain H2S. These results demonstrate that sediment characteristics, including H2S level and organic content, were key structuring factors for the macrozoobenthic assemblage in organically polluted estuarine sediments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Seasonal changes in infaunal community structure in a hypertrophic brackish canal: Effects of hypoxia, sulfide, and predator-prey interaction.

PubMed

Kanaya, Gen; Nakamura, Yasuo; Koizumi, Tomoyoshi; Yamada, Katsumasa

2015-07-01

We conducted a one-year survey of macrozoobenthic community structure at 5 stations in a eutrophic canal in inner Tokyo Bay, focusing on the impacts of hypoxia, sediment H2S, and species interaction in the littoral soft-bottom habitats. Complete defaunation or decreasing density of less-tolerant taxa occurred under hypoxia during warmer months, especially at subtidal or sulfidic stations; this was followed by rapid recolonization by opportunistic polychaetes in fall-winter. Sedimentary H2S increased the mortality of macroinvertebrates under hypoxia or delayed population recovery during recolonization. The density of several polychaetes (e.g., Pseudopolydora reticulata) declined in winter, coincident with immigration of the predator Armandia lanceolata. This suggests that absence of A. lanceolata under moderate hypoxia enabled the proliferation of prey taxa. We conclude that oxygen concentration, sediment H2S, and hypoxia-induced changes in species interactions are potential drivers for spatiotemporal changes in macrozoobenthic assemblage structure in hypoxia-prone soft-bottom communities. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impacts of ocean acidification on sperm develop with exposure time for a polychaete with long lived sperm.

PubMed

Campbell, Anna L; Ellis, Robert P; Urbina, Mauricio A; Mourabit, Sulayman; Galloway, Tamara S; Lewis, Ceri

2017-08-01

The majority of marine invertebrate species release eggs and sperm into seawater for external fertilisation. Seawater conditions are currently changing at an unprecedented rate as a consequence of ocean acidification (OA). Sperm are thought to be particularly vulnerable to these changes and may be exposed to external environmental conditions for variable periods of time between spawning and fertilisation. Here, we undertook a mechanistic investigation of sperm swimming performance in the coastal polychaete Arenicola marina during an extended exposure to OA conditions (pH NBS 7.77, 1000 μatm pCO 2 ). We found that key fitness-related aspects of sperm functioning declined faster under OA conditions i.e. impacts became apparent with exposure time. Sperm swimming speed (VCL), the number of motile sperm and sperm path linearity all dropped significantly after 4 h under OA conditions whilst remaining constant under ambient conditions at this time point. Our results highlight the importance of sperm exposure duration in ocean acidification experiments and may help towards explaining species specific differences in response. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Smelling danger - alarm cue responses in the polychaete Nereis (Hediste) diversicolor (Müller, 1776) to potential fish predation.

PubMed

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.

Schistosomicidal Activity of Alkyl-phenols from the Cashew Anacardium occidentale against Schistosoma mansoni Adult Worms.

PubMed

Alvarenga, Tavane A; de Oliveira, Pollyanna F; de Souza, Julia M; Tavares, Denise C; Andrade E Silva, Márcio L; Cunha, Wilson R; Groppo, Milton; Januário, Ana H; Magalhães, Lizandra G; Pauletti, Patrícia M

2016-11-23

Bioassay-guided study of the ethanol extract from the cashew Anacardium occidentale furnished cardol triene (1), cardol diene (2), anacardic acid triene (3), cardol monoene (4), anacardic acid diene (5), 2-methylcardol triene (6), and 2-methylcardol diene (7). 1D- and 2D-NMR experiments and HRMS analysis confirmed the structures of compounds 1-7. Compounds 2 and 7 were active against Schistosoma mansoni adult worms in vitro, with LC 50 values of 32.2 and 14.5 μM and selectivity indices of 6.1 and 21.2, respectively. Scanning electron microscopy of the tegument of male worms in the presence of compound 7 at 25 μM after 24 h of incubation showed severe damage as well as peeling and reduction in the number of spine tubercles. Transmission electron microscopy analyses revealed swollen mitochondrial membrane, vacuoles, and altered tegument in worms incubated with compound 2 (25 μM after 24 h). Worms incubated with compound 7 (25 μM after 24 h) had lysed interstitial tissue, degenerated mitochondria, and drastically altered tegument. Together, the results indicated that compound 7 presents promising in vitro schistosomicidal activity.

Real-time monitoring of immune responses under pathogen invasion and drug interference by integrated microfluidic device coupled with worm-based biosensor.

PubMed

Hu, Liang; Ge, Anle; Wang, Xixian; Wang, Shanshan; Yue, Xinpei; Wang, Jie; Feng, Xiaojun; Du, Wei; Liu, Bi-Feng

2018-07-01

Immune response to environmental pathogen invasion is a complex process to prevent host from further damage. For quantitatively understanding immune responses and revealing the pathogenic environmental information, real-time monitoring of such a whole dynamic process with single-animal resolution in well-defined environments is highly desired. In this work, an integrated microfluidic device coupled with worm-based biosensor was proposed for in vivo studies of dynamic immune responses and antibiotics interference in infected C. elegans. Individual worms housed in chambers were exposed to the various pathogens and discontinuously manipulated for imaging with limited influence on physiological activities. The expression of immune responses gene (irg-1) was time-lapse measured in intact worms during pathogen infection. Results demonstrated that irg-1 gene could be induced in the presence of P. aeruginosa strain PA14 in a dose-dependent manner, and the survival of infected worm could be rescued under gentamicin or erythromycin treatments. We expect it to be a versatile platform to facilitate future studies on pathogenesis researches and rapid drug screen using C. elegans disease model. Copyright © 2018 Elsevier B.V. All rights reserved.

Care of captive woodcocks

USGS Publications Warehouse

Stickel, William H.; Sheldon, William G.; Stickel, Lucille F.

1965-01-01

Numbers of American woodcocks (Philohela minor) were held in cages for experimental work lasting several months. Injuries caused by birds attempting to flush were greatly reduced by clipping feathers from one wing, by making cage walls opaque, and by using high cages or false ceilings of fabric. Size of cage was found not to be important, to judge from weight changes, so long as ample food was unmistakably available. Birds were kept in both large and small cages without social conflicts. Cages on the ground proved too unsanitary for long-term use; small steel cages with removable floors were practical but did not solve the sanitation problem. Living earthworms (Lumbricus terrestris) were provided daily in amounts roughly equal to weights of birds. Birds gained on this food when worms were offered in suitable ways. The feeding tray recommended is a large roasting pan with a snap-on metal rim that retards loss of worms. Trays contained moist peat in which birds probed for worms. Two efforts to keep woodcocks on a diet of red worms (Eisenia foetide) were unsuccessful; use of this worm was considered responsible. Woodcocks were handled and transported for short periods with least injury to them when they were rolled individually in soft bags.

Recovery of Oesophagostomum dentatum from pigs by isolation of parasites migrating from large intestinal contents embedded in agar-gel.

PubMed

Slotved, H C; Barnes, E H; Bjørn, H; Christensen, C M; Eriksen, L; Roepstorff, A; Nansen, P

1996-06-01

Four groups with three pigs in each group were inoculated with Oesophagostomum dentatum larvae (L3 larvae). Groups 1 and 3 were inoculated with 20,000 larvae, and Groups 2 and 4 with 200,000 larvae. On Days 11 and 34, respectively, Groups 1 and 2 and Groups 3 and 4 were slaughtered, and the contents from the large intestines collected. Subsamples of intestinal contents were mixed with agar to a final concentration of 1% agar and allowed to set. The worms were allowed to migrate from the agar-gel into 38 degrees C 0.9% saline overnight. Then the worms were collected on a sieve (38 microns mesh) and counted. The worms retained in the agar-gel were counted after pouring the melted agar through a sieve (38 microns mesh). The results showed that more than 95% of the worms migrated out of the agar-gel, and subsequently were available for counting in an almost clean suspension. Additionally the method yielded a high worm recovery; all stages were recovered. The recovery percentage was not significantly affected by either the dose of parasites or the time interval from slaughtering to start of incubation (37-128 min).

Microgravity elicits reproducible alterations in cytoskeletal and metabolic gene and protein expression in space-flown Caenorhabditis elegans

PubMed Central

Higashibata, Akira; Hashizume, Toko; Nemoto, Kanako; Higashitani, Nahoko; Etheridge, Timothy; Mori, Chihiro; Harada, Shunsuke; Sugimoto, Tomoko; Szewczyk, Nathaniel J; Baba, Shoji A; Mogami, Yoshihiro; Fukui, Keiji; Higashitani, Atsushi

2016-01-01

Although muscle atrophy is a serious problem during spaceflight, little is known about the sequence of molecular events leading to atrophy in response to microgravity. We carried out a spaceflight experiment using Caenorhabditis elegans onboard the Japanese Experiment Module of the International Space Station. Worms were synchronously cultured in liquid media with bacterial food for 4 days under microgravity or on a 1-G centrifuge. Worms were visually observed for health and movement and then frozen. Upon return, we analyzed global gene and protein expression using DNA microarrays and mass spectrometry. Body length and fat accumulation were also analyzed. We found that in worms grown from the L1 larval stage to adulthood under microgravity, both gene and protein expression levels for muscular thick filaments, cytoskeletal elements, and mitochondrial metabolic enzymes decreased relative to parallel cultures on the 1-G centrifuge (95% confidence interval (P⩽0.05)). In addition, altered movement and decreased body length and fat accumulation were observed in the microgravity-cultured worms relative to the 1-G cultured worms. These results suggest protein expression changes that may account for the progressive muscular atrophy observed in astronauts. PMID:28725720

7 CFR 51.1210 - U.S. Fancy.

Code of Federal Regulations, 2012 CFR

2012-01-01

... which are mature but not soft or overripe, well formed and which are free from decay, bacterial spot, cuts which are not healed, growth cracks, hail injury, scab, scale, split pits, worms, worm holes, leaf...

7 CFR 51.1212 - U.S. No. 1.

Code of Federal Regulations, 2013 CFR

2013-01-01

... which are free from decay, growth cracks, cuts which are not healed, worms, worm holes, and free from damage caused by bruises, dirt, or other foreign material, bacterial spot, scab, scale, hail injury, leaf...

7 CFR 51.1212 - U.S. No. 1.

Code of Federal Regulations, 2014 CFR

2014-01-01

... which are free from decay, growth cracks, cuts which are not healed, worms, worm holes, and free from damage caused by bruises, dirt, or other foreign material, bacterial spot, scab, scale, hail injury, leaf...

7 CFR 51.1210 - U.S. Fancy.

Code of Federal Regulations, 2010 CFR

2010-01-01

... which are mature but not soft or overripe, well formed and which are free from decay, bacterial spot, cuts which are not healed, growth cracks, hail injury, scab, scale, split pits, worms, worm holes, leaf...

7 CFR 51.1210 - U.S. Fancy.

Code of Federal Regulations, 2011 CFR

2011-01-01

... which are mature but not soft or overripe, well formed and which are free from decay, bacterial spot, cuts which are not healed, growth cracks, hail injury, scab, scale, split pits, worms, worm holes, leaf...

7 CFR 51.3146 - U.S. Extra No. 1.

Code of Federal Regulations, 2010 CFR

2010-01-01

... from decay, broken skins which are not healed, worms, worm holes and free from injury caused by split... spot, scale, scars, russeting, other disease, insects or mechanical or other means. (a) At least 75...

7 CFR 51.1280 - Serious damage.

Code of Federal Regulations, 2012 CFR

2012-01-01

.... (5) Insects: (i) Worm holes. More than three healed codling moth stings, of which not more than two... appearance to an equal extent. 2 (ii) Blister mite or canker worm injury which affects an aggregate area of...

Winter losses of Canada geese at Pea Island, North Carolina

USGS Publications Warehouse

Cowan, A.B.; Herman, C.M.

1955-01-01

Report of research and findings to date. Topics discussed include: studies on life history and biology of gizzard worm; results of autopsies; experiments on survival and transmission of gizzard worm eggs and larvae in both field and laboratory; persistence of infections; and results of infections in geese of different ages. Cause of deaths has not been finally determined, but indications are that gizzard worm is an important contributing factor and that poor physical condition, brought about at least partially by malnutrition, also contributes to the losses.

Molecular and serological survey on taeniasis and cysticercosis in Kanchanaburi Province, Thailand.

PubMed

Anantaphruti, Malinee T; Okamoto, Munehiro; Yoonuan, Tippayarat; Saguankiat, Surapol; Kusolsuk, Teera; Sato, Megumi; Sato, Marcello O; Sako, Yasuhito; Waikagul, Jitra; Ito, Akira

2010-09-01

A community-based field survey on taeniasis and cysticercosis was performed in two villages in Thong Pha Phum District, Kanchanaburi Province, central Thailand, where 3 Taenia species, T. solium, T. saginata and T. asiatica, are sympatrically occurring. Four (0.6%) out of 667 stool samples were egg-positive for Taenia sp. by Kato-Katz technique. Three out of those four persons and other three persons who were Taenia egg-negative but having a recent (<1 year) history of discharging worms in stool were treated with niclosamide. One Taenia egg-positive woman was not treated because of severe ascites. After treatment, three persons expelled long strobilae with scolices and two persons expelled strobilae without scolex. One Taenia egg-positive person did not expel any worms post-treatment. Among 5 persons, four expelled a single worm, whereas one expelled multiple worms, may be 6 worms but not confirmed by detection of scolices. One scolex was armed with hooklets, whereas 2 others did not. Multiplex PCR of 10 expelled proglottids (including 6 estimated worms from one patient) revealed that one sample was T. solium, one T. saginata, and 8 T. asiatica. A total of 159 residents agreed to receive a serological test for cysticercosis. By ELISA using partially purified glycoprotein antigen, 9 cases, 5 and 4 from villages A and B respectively, were found to be sero-positive. The five and an additional sample on the border line from village A were evaluated using confirmative immunoblot using recombinant chimeric antigen. Among the six samples, four including the border line sample were confirmed to be cysticercosis by immunoblotting. One of the 4 persons had neurological symptoms with nodular lesions in the brain by computed tomography. These 4 confirmed or suspected cysticercosis cases were free of T. solium worms, but two of them including confirmed NCC case had a past (>1 year) history of expelling proglottids in the stool.

Biotic interactions at hydrothermal vents: Recruitment inhibition by the mussel Bathymodiolus thermophilus

NASA Astrophysics Data System (ADS)

Lenihan, H. S.; Mills, S. W.; Mullineaux, L. S.; Peterson, C. H.; Fisher, C. R.; Micheli, F.

2008-12-01

The structure and dynamics of marine communities are regulated in part by variation in recruitment. As in other ecosystems, recruitment at deep-sea hydrothermal vents is controlled by the interplay of propagule supply and behavior, gradients in physical-chemical conditions, and biotic interactions during pre- and post-settlement periods. Recent research along the East Pacific Rise indicates that inhibition of recently settled larvae by mobile predators (mainly limpets) influences patterns of recruitment and subsequent community succession. We conducted a manipulative experiment at the same sites (˜2510 m water depth) to test whether high-density assemblages of the mussel Bathymodiolus thermophilus also inhibit recruitment. In a preliminary study, recruitment of vent invertebrates within the faunal zone dominated by B. thermophilus was strikingly different at two sites, East Wall and Worm Hole. East Wall had high densities of mussels but very low total recruitment. In contrast, Worm Hole had few mussels but high recruitment. Using the submersible Alvin, we transplanted a large number of mussels from East Wall to Worm Hole and quantified recruitment on basalt blocks placed in three treatments: (1) naturally high densities of mussels at East Wall; (2) naturally low densities of mussels at Worm Hole; and (3) high densities of transplanted mussels at Worm Hole. After 11 months, a total of 24 taxa had recruited to the basalt blocks. Recruitment was 44-60% lower in the transplanted high-density mussel patch at Worm Hole and the natural high-density patch at East Wall than within the natural low-density patch at Worm Hole. Biotic processes that may have caused the pattern of recruitment observed included predation of larvae via water filtration by mussels, larval avoidance of superior competitors, interference competition, and enhanced predation by species within the mussel-bed community. Our results indicate that biotic interactions affecting recruitment must be understood to explain patterns of invertebrate community organization and dynamics at hydrothermal vents.

Low virulence potential and in vivo transformation ability in the honey bee venom treated Clinostomum complanatum.

PubMed

Rehman, Abdur; Ullah, Rizwan; Jaiswal, Neeshma; Khan, M A Hannan; Rehman, Lubna; Beg, Mirza Ahmar; Malhotra, Sandeep K; Abidi, S M A

2017-12-01

The helminth parasites possess great capabilities to adapt themselves within their hosts and also develop strategies to render the commonly used anthelmintics ineffective leading to the development of resistance against these drugs. Besides using anthelmintics the natural products have also been tested for their anti-parasitic effects. Therapeutic efficacy of honey bee venom (HBV) has been tested in various ailments including some protozoal infections but very little is known about its anthelmintic properties. To investigate the anthelmintic effect of HBV the excysted progenetic metacercariae of Clinostomum complanatum, a heamophagic, digenetic trematode with zoonotic potential, infecting a wide variety of hosts, were obtained from Trichogaster fasciatus, a forage fish, which serves as the intermediate host. The metacercarial worms were in vitro incubated in RPMI-1640 medium containing HBV along with the controls which were devoid of HBV for the analysis of worm motility, enzyme activity, polypeptide profile and surface topographical changes. The motility of the worms was significantly reduced in a time dependent manner with an increase in the concentration of HBV. Following incubation of worms the release of cysteine proteases was inhibited in the presence of HBV as revealed by gelatine substrate gel zymography. As well as the polypeptide profile was also significantly influenced, particularly intensity/expression of M r 19.4 kDa, 24 kDa and 34 kDa was significantly reduced upon HBV treatment. The HBV treatment also inhibited antioxidant enzyme, superoxide dismutase (SOD) and Glutathione-S-transferase (GST) significantly (p < 0.05) in the worms. The scanning electron microscopy of the HBV treated worms revealed tegumental disruptions and erosion of papillae as well as spines showing vacuolation in the tegument. The HBV treated worms also showed a marked decline in the transformation rate when introduced into an experimental host which further reflect the anthelmintic potential of HBV. Copyright © 2017 Elsevier Inc. All rights reserved.

Trichuris suis and Oesophagostomum dentatum show different sensitivity and accumulation of fenbendazole, albendazole and levamisole in vitro.

PubMed

Hansen, Tina V A; Nejsum, Peter; Friis, Christian; Olsen, Annette; Thamsborg, Stig Milan

2014-04-01

The single-dose benzimidazoles used against Trichuris trichiura infections in humans are not satisfactory. Likewise, the benzimidazole, fenbendazole, has varied efficacy against Trichuris suis whereas Oesophagostomum dentatum is highly sensitive to the drug. The reasons for low treatment efficacy of Trichuris spp. infections are not known. We studied the effect of fenbendazole, albendazole and levamisole on the motility of T. suis and O. dentatum and measured concentrations of the parent drug compounds and metabolites of the benzimidazoles within worms in vitro. The motility and concentrations of drug compounds within worms were compared between species and the maximum specific binding capacity (Bmax) of T. suis and O. dentatum towards the benzimidazoles was estimated. Comparisons of drug uptake in living and killed worms were made for both species. The motility of T. suis was generally less decreased than the motility of O. dentatum when incubated in benzimidazoles, but was more decreased when incubated in levamisole. The Bmax were significantly lower for T. suis (106.6, and 612.7 pmol/mg dry worm tissue) than O. dentatum (395.2, 958.1 pmol/mg dry worm tissue) when incubated for 72 hours in fenbendazole and albendazole respectively. The total drug concentrations (pmol/mg dry worm tissue) were significantly lower within T. suis than O. dentatum whether killed or alive when incubated in all tested drugs (except in living worms exposed to fenbendazole). Relatively high proportions of the anthelmintic inactive metabolite fenbendazole sulphone was measured within T. suis (6-17.2%) as compared to O. dentatum (0.8-0.9%). The general lower sensitivity of T. suis towards BZs in vitro seems to be related to a lower drug uptake. Furthermore, the relatively high occurrence of fenbendazole sulphone suggests a higher detoxifying capacity of T. suis as compared to O. dentatum.

Trichuris suis and Oesophagostomum dentatum Show Different Sensitivity and Accumulation of Fenbendazole, Albendazole and Levamisole In Vitro

PubMed Central

Hansen, Tina V. A.; Nejsum, Peter; Friis, Christian; Olsen, Annette; Thamsborg, Stig Milan

2014-01-01

Background The single-dose benzimidazoles used against Trichuris trichiura infections in humans are not satisfactory. Likewise, the benzimidazole, fenbendazole, has varied efficacy against Trichuris suis whereas Oesophagostomum dentatum is highly sensitive to the drug. The reasons for low treatment efficacy of Trichuris spp. infections are not known. Methodology We studied the effect of fenbendazole, albendazole and levamisole on the motility of T. suis and O. dentatum and measured concentrations of the parent drug compounds and metabolites of the benzimidazoles within worms in vitro. The motility and concentrations of drug compounds within worms were compared between species and the maximum specific binding capacity (Bmax) of T. suis and O. dentatum towards the benzimidazoles was estimated. Comparisons of drug uptake in living and killed worms were made for both species. Principal findings The motility of T. suis was generally less decreased than the motility of O. dentatum when incubated in benzimidazoles, but was more decreased when incubated in levamisole. The Bmax were significantly lower for T. suis (106.6, and 612.7 pmol/mg dry worm tissue) than O. dentatum (395.2, 958.1 pmol/mg dry worm tissue) when incubated for 72 hours in fenbendazole and albendazole respectively. The total drug concentrations (pmol/mg dry worm tissue) were significantly lower within T. suis than O. dentatum whether killed or alive when incubated in all tested drugs (except in living worms exposed to fenbendazole). Relatively high proportions of the anthelmintic inactive metabolite fenbendazole sulphone was measured within T. suis (6–17.2%) as compared to O. dentatum (0.8–0.9%). Conclusion/Significance The general lower sensitivity of T. suis towards BZs in vitro seems to be related to a lower drug uptake. Furthermore, the relatively high occurrence of fenbendazole sulphone suggests a higher detoxifying capacity of T. suis as compared to O. dentatum. PMID:24699263

Defeating "the worm" in Rajasthan. Women and water: India.

PubMed

Datta, B

1993-01-01

In theory, the Indian government's SWACH project uses an integrated approach to sanitation, water, and community health, but its priority is guinea worm control. It operates in 4 districts of Rajasthan. Ways to break the guinea worm cycle are converting step wells to draw wells, provision of hand pumps, teaching people to filter water before drinking it, and ayurvedic techniques to remove the guinea worm from the body before it breaks through the skin, at which point it becomes ineffective. Between 1986 and 1992, SWACH's efforts reduced the guinea worm cases 10-fold (from about 8000 to 800). In 1990 Sarsiya had 56 cases, but in 1992 it had none. SWACH has trained 70 local women to do handpump maintenance. It is in their interest to be handpump mechanics, since women collect the water. The village governments contract handpump repair out to these women. Each mechanic is responsible for handpump maintenance in about 10 villages. Even though the women complain that villagers do not know how to use handpumps, they do not teach then how to use the pumps. In fact, this reflects the project's lack of a broader approach to health education. SWACH's strength lies in the tangibles (e.g., handpumps and water filters). It has brought potable water to almost 1.5 million Indians. Most villagers are guinea worm specialists, but know little about other waterborne diseases and infectious diseases. SWACH does not monitor its effects on the prevalence of other waterborne diseases. SWACH staff also neglect community health. For example, a local midwife in the remote tribal village of Sarsiya was surprised to learn that she can prevent infection by boiling blades. She explained that SWACH field workers never informed her about the benefits of boiling. A man who once had guinea worm disease did not know how one gets it, yet SWACH staff treated him. Evaluations note the gap between project staff and villagers.

CD4 T Cells and Major Histocompatibility Complex Class II Expression Influence Worm Expulsion and Increased Intestinal Muscle Contraction during Trichinella spiralis Infection

PubMed Central

Vallance, Bruce A.; Galeazzi, Francesca; Collins, Stephen M.; Snider, Denis P.

1999-01-01

Expulsion of intestinal nematode parasites and the associated increased contraction by intestinal muscle are T cell dependent, since both are attenuated in athymic rodents. The CD4 T-cell subset has been strongly associated with worm expulsion; however, the relationship between these cells, antigen presentation, and worm expulsion is not definitive and the role of these factors in intestinal muscle hypercontractility has not been defined. We infected C57BL/6, athymic, CD4-deficient, CD8α-deficient, and major histocompatibility complex class II (MHC II)-deficient (C2d) mice with Trichinella spiralis larvae. We examined intestinal worm numbers, longitudinal muscle contraction, and MHC II expression. Numerous MHC II-positive cells were identified within the muscularis externa of infected but not uninfected C57BL/6 mice. C57BL/6 and CD8α-deficient mice developed large increases in muscle contraction, expelling the parasite by day 21. Athymic and C2d mice exhibited much smaller increases in muscle contraction and delayed parasite expulsion. CD4-deficient mice exhibited intermediate levels of muscle contraction and delayed parasite expulsion. To further examine the role of MHC II and CD4 T cells, we irradiated C2d mice and reconstituted them with C57BL/6 bone marrow alone or with C57BL/6 CD4 T cells. C57BL/6 bone marrow alone did not affect muscle function or worm expulsion in recipient C2d mice. Partial CD4 T-cell reconstitution was sufficient to restore increased muscle contraction but not worm expulsion. Thus, hematopoietic MHC II expression alone is insufficient for the development of muscle hypercontractility and worm expulsion, but the addition of even small numbers of CD4 T cells was sufficient to induce intestinal muscle pathophysiology. PMID:10531271

High prevalence of Angiostrongylus cantonensis (rat lungworm) on eastern Hawai'i Island: A closer look at life cycle traits and patterns of infection in wild rats (Rattus spp.).

PubMed

Jarvi, Susan I; Quarta, Stefano; Jacquier, Steven; Howe, Kathleen; Bicakci, Deniz; Dasalla, Crystal; Lovesy, Noelle; Snook, Kirsten; McHugh, Robert; Niebuhr, Chris N

2017-01-01

The nematode Angiostrongylus cantonensis is a zoonotic pathogen and the etiological agent of human angiostrongyliasis or rat lungworm disease. Hawai'i, particularly east Hawai'i Island, is the epicenter for angiostrongyliasis in the USA. Rats (Rattus spp.) are the definitive hosts while gastropods are intermediate hosts. The main objective of this study was to collect adult A. cantonensis from wild rats to isolate protein for the development of a blood-based diagnostic, in the process we evaluated the prevalence of infection in wild rats. A total of 545 wild rats were sampled from multiple sites in the South Hilo District of east Hawai'i Island. Adult male and female A. cantonensis (3,148) were collected from the hearts and lungs of humanely euthanized Rattus rattus, and R. exulans. Photomicrography and documentation of multiple stages of this parasitic nematode in situ were recorded. A total of 45.5% (197/433) of rats inspected had lung lobe(s) (mostly upper right) which appeared granular indicating this lobe may serve as a filter for worm passage to the rest of the lung. Across Rattus spp., 72.7% (396/545) were infected with adult worms, but 93.9% (512/545) of the rats were positive for A. cantonensis infection based on presence of live adult worms, encysted adult worms, L3 larvae and/or by PCR analysis of brain tissue. In R. rattus we observed an inverse correlation with increased body mass and infection level of adult worms, and a direct correlation between body mass and encysted adult worms in the lung tissue, indicating that larger (older) rats may have developed a means of clearing infections or regulating the worm burden upon reinfection. The exceptionally high prevalence of A. cantonensis infection in Rattus spp. in east Hawai'i Island is cause for concern and indicates the potential for human infection with this emerging zoonosis is greater than previously thought.

Effects of alcoholic extract of Curcuma longa on Ascaridia infestation affecting chicken.

PubMed

Alrubaie, Abdulrazak Labi

2015-07-01

Ascaridia galli, the common intestinal nematode, remains a major cause of economic loss in the poultry industry in developing countries. Treatments using chemicals are not only expensive but also affect host health. Plant extracts as better alternative is gaining significance. Here, we have studied the effects of alcoholic extract of turmeric, Curcuma longa L. (Zingiberaceae) roots, against A. galli infection in chicken. Different concentrations of C. longa root extract were tested in vitro on 5 groups of adults A. galli worms and in vivo on 6 groups of chicks. The results showed that the turmeric root extract @ 60 mg mL(-1) in vitro significantly (P < 0.001) proved paralytic and fatal against worms (16.80 ± 1.28 h). In vivo, chicken groups (G2-G6) were infected with an average of 300 ± 12 embryonated eggs of A. galli. The G2 was not given any treatment while G3 was treated with piperazine (@ 200 mg kg(-1) body wt.); and Groups 4, 5 and 6 were given turmeric @ 200, 400 and 600 mg kg(-1) body wt., respectively. The mean number of worms extracted at the end of the trial in G2 (untreated) was 18.10 ± 2.42, while the G3 treated with piperazine had no worms. Groups 4 and 5 did not show any significant difference compared to G2. However, G6 that had 3.20 ± 1.33 worms was statistically significant. Higher concentrations of turmeric given to infected chickens significantly reduced the length and weight of worms. The study showed that the worm infestation damaged the intestinal villi, and.treatment with high concentration of C. longa had healing effects and restored the integrity of intestinal mucosa. The results have demonstrated the ameliorating effect of C. longa turmeric on A. galli infested chickens.

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 polychaetes are preyed upon by drilling predators and may provide a viable source of data on biotic interactions in the fossil record. PMID:22496828

Physiological and biochemical responses of two keystone polychaete species: Diopatra neapolitana and Hediste diversicolor to Multi-walled carbon nanotubes

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Marchi, Lucia

Multi-walled carbon nanotubes (MWCNTs) are one of the most important carbon Nanomaterials (NMs). The production and use of these carbon NMs is increasing rapidly and, therefore, the need to assess their presence in the environment and associated risks has become increasingly important. However, limited literature is available regarding the impacts induced in aquatic organisms by this pollutant, namely in invertebrate species. Diopatra neapolitana and Hediste diversicolor are keystone polychaete species inhabiting estuaries and shallow water bodies intertidal mudflats, frequently used to evaluate the impact of environmental disturbances in these systems. To our knowledge, no information is available on physiological andmore » biochemical alterations on these two species due to MWCNTs exposure. Thus, the present study aimed to assess the toxic effects of different MWCNTs concentrations (0.01; 0.10 and 1.00 mg/L) in both species physiological (regenerative capacity and respiration rate) and biochemical (energy reserves, metabolic activities, oxidative stress related biomarkers and neurotoxicity markers) performance, after 28 days of exposure. The results obtained revealed that exposure to MWCNTs induced negative effects on the regenerative capacity of D. neapolitana. Additionally, higher MWCNTs concentrations induced increased respiration rates in D. neapolitana. MWCNTs altered energy-related responses, with higher values of electron transport system activity, glycogen and protein concentrations in both polychaetes exposed to this contaminant. Furthermore, when exposed to MWCNTs both species showed oxidative stress with higher lipid peroxidation, lower ratio between reduced and oxidized glutathione, and higher activity of antioxidant (catalase and superoxide dismutase) and biotransformation (glutathione-S-transferases) enzymes in exposed organisms. - Highlights: • MWCNTs induced negative effects on the regenerative capacity of Diopatra neapolitana. • Diopatra neapolitana and Hediste diversicolor exposed to MWCNTs showed oxidative stress. • Both species under MWCNTs increased their metabolic capacity. • Inhibition of cholinesterases confirmed neurotoxicity of MWCNTs in both species. • D. neapolitana and H. diversicolor are potential bioindicators to monitor carbon NMs pollution.« less

Temporal and spatial distribution of the meiobenthic community in Daya Bay, South China Sea

NASA Astrophysics Data System (ADS)

Tang, L.; Li, H. X.; Yan, Y.

2012-04-01

Spatial and temporal biodiversity patterns of the meiobenthos were studied for the first time in Daya Bay, which is a tropical semi-enclosed basin located in the South China Sea. The abundance, biomass, and composition of the meiobenthos and the basic environmental factors in the bay were investigated. The following 19 taxonomic groups were represented in the meiofauna: Nematoda, Copepoda, Polychaeta, Oligochaeta, Kinorhyncha, Gastrotricha, Ostracoda, Bivalvia, Turbellaria, Nemertinea, Sipuncula, Hydroida, Amphipoda, Cumacea, Halacaroidea, Priapulida, Echinodermata, Tanaidacea, and Rotifera. Total abundance and biomass of the meiobenthos showed great spatial and temporal variation, with mean values of 993.57 ± 455.36 ind cm-2 and 690.51 ± 210.64 μg 10 cm-2, respectively. Nematodes constituted 95.60 % of the total abundance and thus had the greatest effect on meiofauna quantity and distribution, followed by copepods (1.55 %) and polychaetes (1.39 %). Meiobenthos abundance was significantly negatively correlated with water depth at stations (r=-0.747, P<0.05) and significantly negatively correlated with silt-clay content (r=-0.516, P<0.01) and medium diameter (r=-0.499, P<0.01) of the sediment. Similar results were found for correlations of biomass and abundance of nematodes with environmental parameters. Polychaete abundance was positively correlated with the bottom water temperature (r=0.456, P<0.01). Meiobenthos abundance differed significantly among seasons (P<0.05), although no significant difference among stations and the interaction of station × season was detected by two-way ANOVA. In terms of vertical distribution, most of the meiobenthos was found in the surface layer of sediment. This pattern was apparent for nematodes and copepods, but a vertical distribution pattern for polychaetes was not as obvious. Based on the biotic indices and analyses of their correlations and variance, the diversity of this community was likely to be influenced by environmental variations.

Estuarine biodiversity as an indicator of groundwater discharge

NASA Astrophysics Data System (ADS)

Silva, A. C. F.; Tavares, P.; Shapouri, M.; Stigter, T. Y.; Monteiro, J. P.; Machado, M.; Cancela da Fonseca, L.; Ribeiro, L.

2012-01-01

Communities located in the interface between marine/brackish and freshwater habitats are likely to be early responders to climatic changes as they are exposed to both saline and freshwater conditions, and thus are expected to be sensitive to any change in their environmental conditions. Climatic effects are predicted to reduce the availability of groundwater, altering the hydrological balance on estuarine-aquifer interfaces. Here, we aimed to characterise the estuarine faunal community along a gradient dependent on groundwater input, under a predicted climatic scenario of reduction in groundwater discharge into the estuary. Sediment macrofauna was sampled along a salinity gradient following both the wet and dry seasons in 2009. Results indicated that species abundance varied significantly with the salinity gradient created by the groundwater discharge into the estuarine habitat and with sampling time. The isopode Cyathura carinata (Krøyer, 1847) and the polychaetes Heteromastus filiformis (Claparède, 1864) and Hediste diversicolor O.F. Muller, 1776 were associated with the more saline locations, while oligochaeta and Spionidae were more abundant in areas of lower salinity. The polychaete Alkmaria romijni Horst, 1919 was the dominant species and ubiquitous throughout sampling stations. This study provides evidence for estuarine fauna to be considered as a potentially valuable indicator of variation in the input of groundwater into marine-freshwater interface habitats, expected from climatic pressures on aquifer levels, condition and recharge rates. For instance, a reduction in the abundance of some polychaete species, found here to be more abundant in freshwater conditions, and increasing Oligochaeta found here on higher salinities, can potentially be early warnings of a reduction in the input of groundwater into estuaries. Estuarine benthic species are often the main prey for commercially important fish predators such as in our case study, making it important to monitor the aquatic habitat interfaces taking into consideration the estuarine macrobenthos and groundwater availability in the system.

Antioxidant responses in estuarine invertebrates exposed to repeated oil spills: Effects of frequency and dosage in a field manipulative experiment.

PubMed

Sandrini-Neto, Leonardo; Pereira, Letícia; Martins, César C; Silva de Assis, Helena C; Camus, Lionel; Lana, Paulo C

2016-08-01

We have experimentally investigated the effects of repeated diesel spills on the bivalve Anomalocardia brasiliana, the gastropod Neritina virginea and the polychaete Laeonereis culveri, by monitoring the responses of oxidative stress biomarkers in a subtropical estuary. Three frequencies of exposure events were compared against two dosages of oil in a factorial experiment with asymmetrical controls. Hypotheses were tested to distinguish between (i) the overall effect of oil spills, (ii) the effect of diesel dosage via different exposure regimes, and (iii) the effect of time since last spill. Antioxidant defense responses and oxidative damage in the bivalve A. brasiliana and the polychaete L. culveri were overall significantly affected by frequent oil spills compared to undisturbed controls. The main effects of diesel spills on both species were the induction of SOD and GST activities, a significant increase in LPO levels and a decrease in GSH concentration. N. virginea was particularly tolerant to oil exposure, with the exception of a significant GSH depletion. Overall, enzymatic activities and oxidative damage in A. brasiliana and L. culveri were induced by frequent low-dosage spills compared to infrequent high-dosage spills, although the opposite pattern was observed for N. virginea antioxidant responses. Antioxidant responses in A. brasiliana and L. culveri were not affected by timing of exposure events. However, our results revealed that N. virginea might have a delayed response to acute high-dosage exposure. Experimental in situ simulations of oil exposure events with varying frequencies and intensities provide a useful tool for detecting and quantifying environmental impacts. In general, antioxidant biomarkers were induced by frequent low-dosage exposures compared to infrequent high-dosage ones. The bivalve A. brasiliana and the polychaete L. culveri are more suitable sentinels due to their greater responsiveness to oil and also to their wider geographical distribution. Copyright © 2016 Elsevier B.V. All rights reserved.

7 CFR 51.3145 - U.S. Fancy.

Code of Federal Regulations, 2014 CFR

2014-01-01

... formed, clean, and free from decay, broken skins which are not healed, worms, worm holes, and free from... not less than one-third of its surface showing red color characteristic of the variety. (See § 51.3150...

7 CFR 51.3145 - U.S. Fancy.

Code of Federal Regulations, 2013 CFR

2013-01-01

... formed, clean, and free from decay, broken skins which are not healed, worms, worm holes, and free from... not less than one-third of its surface showing red color characteristic of the variety. (See § 51.3150...

Hybrid epidemics--a case study on computer worm conficker.

PubMed

Zhang, Changwang; Zhou, Shi; Chain, Benjamin M

2015-01-01

Conficker is a computer worm that erupted on the Internet in 2008. It is unique in combining three different spreading strategies: local probing, neighbourhood probing, and global probing. We propose a mathematical model that combines three modes of spreading: local, neighbourhood, and global, to capture the worm's spreading behaviour. The parameters of the model are inferred directly from network data obtained during the first day of the Conficker epidemic. The model is then used to explore the tradeoff between spreading modes in determining the worm's effectiveness. Our results show that the Conficker epidemic is an example of a critically hybrid epidemic, in which the different modes of spreading in isolation do not lead to successful epidemics. Such hybrid spreading strategies may be used beneficially to provide the most effective strategies for promulgating information across a large population. When used maliciously, however, they can present a dangerous challenge to current internet security protocols.

Symbiosis insights through metagenomic analysis of a microbial consortium.

PubMed

Woyke, Tanja; Teeling, Hanno; Ivanova, Natalia N; Huntemann, Marcel; Richter, Michael; Gloeckner, Frank Oliver; Boffelli, Dario; Anderson, Iain J; Barry, Kerrie W; Shapiro, Harris J; Szeto, Ernest; Kyrpides, Nikos C; Mussmann, Marc; Amann, Rudolf; Bergin, Claudia; Ruehland, Caroline; Rubin, Edward M; Dubilier, Nicole

2006-10-26

Symbioses between bacteria and eukaryotes are ubiquitous, yet our understanding of the interactions driving these associations is hampered by our inability to cultivate most host-associated microbes. Here we use a metagenomic approach to describe four co-occurring symbionts from the marine oligochaete Olavius algarvensis, a worm lacking a mouth, gut and nephridia. Shotgun sequencing and metabolic pathway reconstruction revealed that the symbionts are sulphur-oxidizing and sulphate-reducing bacteria, all of which are capable of carbon fixation, thus providing the host with multiple sources of nutrition. Molecular evidence for the uptake and recycling of worm waste products by the symbionts suggests how the worm could eliminate its excretory system, an adaptation unique among annelid worms. We propose a model that describes how the versatile metabolism within this symbiotic consortium provides the host with an optimal energy supply as it shuttles between the upper oxic and lower anoxic coastal sediments that it inhabits.

Logistics of Guinea Worm Disease Eradication in South Sudan

PubMed Central

Jones, Alexander H.; Becknell, Steven; Withers, P. Craig; Ruiz-Tiben, Ernesto; Hopkins, Donald R.; Stobbelaar, David; Makoy, Samuel Yibi

2014-01-01

From 2006 to 2012, the South Sudan Guinea Worm Eradication Program reduced new Guinea worm disease (dracunculiasis) cases by over 90%, despite substantial programmatic challenges. Program logistics have played a key role in program achievements to date. The program uses disease surveillance and program performance data and integrated technical–logistical staffing to maintain flexible and effective logistical support for active community-based surveillance and intervention delivery in thousands of remote communities. Lessons learned from logistical design and management can resonate across similar complex surveillance and public health intervention delivery programs, such as mass drug administration for the control of neglected tropical diseases and other disease eradication programs. Logistical challenges in various public health scenarios and the pivotal contribution of logistics to Guinea worm case reductions in South Sudan underscore the need for additional inquiry into the role of logistics in public health programming in low-income countries. PMID:24445199

Logistics of Guinea worm disease eradication in South Sudan.

PubMed

Jones, Alexander H; Becknell, Steven; Withers, P Craig; Ruiz-Tiben, Ernesto; Hopkins, Donald R; Stobbelaar, David; Makoy, Samuel Yibi

2014-03-01

From 2006 to 2012, the South Sudan Guinea Worm Eradication Program reduced new Guinea worm disease (dracunculiasis) cases by over 90%, despite substantial programmatic challenges. Program logistics have played a key role in program achievements to date. The program uses disease surveillance and program performance data and integrated technical-logistical staffing to maintain flexible and effective logistical support for active community-based surveillance and intervention delivery in thousands of remote communities. Lessons learned from logistical design and management can resonate across similar complex surveillance and public health intervention delivery programs, such as mass drug administration for the control of neglected tropical diseases and other disease eradication programs. Logistical challenges in various public health scenarios and the pivotal contribution of logistics to Guinea worm case reductions in South Sudan underscore the need for additional inquiry into the role of logistics in public health programming in low-income countries.

[Helminth infection of slaughtered sheep in Upper Bavaria. 3. Distribution of colonization of nematodes in the large intestine of sheep].

PubMed

Rehbein, S; Lindner, T; Kollmannsberger, M; Winter, R; Visser, M

1997-06-01

The distribution of Chabertia (Ch.) ovina, Oesophagostomum (O.) venulosum and Trichuris spp. within the large intestine of naturally infected sheep in the dependence of worm counts and the presence of nematodes of other species or genera was evaluated. The large intestine was divided into 4 sections. More than 75% of Ch. ovina were found within the disk-like section of the colon independently from worm count and presence of nematodes of other species. O. venulosum and Trichuris spp. preferred the caecum and the first section of the colon up to the beginning of the disk-like section. In both, the share of worms recovered from the first section of the colon did increase with higher worm counts. The simultaneous presence of O. venulosum and Trichuris spp. had a significantly negative influence on the share of Trichuris spp. isolated from the caecum.

Combining Biomimetic Block Copolymer Worms with an Ice-Inhibiting Polymer for the Solvent-Free Cryopreservation of Red Blood Cells.

PubMed

Mitchell, Daniel E; Lovett, Joseph R; Armes, Steven P; Gibson, Matthew I

2016-02-18

The first fully synthetic polymer-based approach for red-blood-cell cryopreservation without the need for any (toxic) organic solvents is reported. Highly hydroxylated block copolymer worms are shown to be a suitable replacement for hydroxyethyl starch as a extracellular matrix for red blood cells. When used alone, the worms are not a particularly effective preservative. However, when combined with poly(vinyl alcohol), a known ice-recrystallization inhibitor, a remarkable additive cryopreservative effect is observed that matches the performance of hydroxyethyl starch. Moreover, these block copolymer worms enable post-thaw gelation by simply warming to 20 °C. This approach offers a new solution for both the storage and transport of red blood cells and also a convenient matrix for subsequent 3D cell cultures. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Modern Antarctic acorn worms form tubes.

PubMed

Halanych, Kenneth M; Cannon, Johanna T; Mahon, Andrew R; Swalla, Billie J; Smith, Craig R

2013-01-01

Acorn worms, or enteropneusts, are vermiform hemichordates that occupy an important position in deuterostome phylogeny. Allied to pterobranch hemichordates, small colonial tube dwellers, modern enteropneusts were thought to be tubeless. However, understanding of hemichordate diversity is poor, as evidenced by absence of reports from some oceanic regions and recent descriptions of large epibenthic deep-water enteropneusts, Torquaratoridae. Here we show, based on expeditions to Antarctica, that some acorn worms produce conspicuous tubes that persist for days. Interestingly, recent fossil descriptions show a Middle Cambrian acorn worm lived in tubes, leading to speculation that these fossils may have been pterobranch forbearers. Our discovery provides the alternative interpretation that these fossils are similar to modern-day torquaratorids and that some behaviours have been conserved for over 500 million years. Moreover, the frequency of Antarctic enteropneusts observed attests to our limited knowledge of Antarctic marine ecosystems, and strengthens hypotheses relating more northern deep-sea fauna to Antarctic shelf fauna.

Optimizing Host-Pathogen In-Flight Assays for C.Elegans and Methicillin-Resistant Staphylococcus Aureus

NASA Astrophysics Data System (ADS)

Hammond, Timothy G.; Birdsall, Holly H.; Hammond, Jeffrey S.; Allen, Patricia L.

2013-02-01

This study addresses controls for an assay of bacterial virulence that has been optimized for space flight studies. Caenorhabditis elegans (C. elegans) worms ingest microorganisms, but are also killed by virulent bacteria. Virulence is assessed by the number of bacteria surviving in co-culture with C. elegans , as measured by optical density at 620 nm. Co -cultures of Methicillin-resistant Staphylococcus aureus (MRSA) with C. elegans have a higher OD620 than MRSA grown alone, which could reflect debris from dead worms and/or enhanced growth of the MRSA in response to worm-derived factors. The use of media conditioned by pre-incubation with worms demonstrated the presence of temperature-stable factors that change MRSA growth in a strain-dependent manner. Some sources of deionized water contain an undefined antibacterial activity present in conditioned, but not fresh untreated media.

Uptake of hexanitrohexaazaisowurtzitane (CL-20) by the earthworm Eisenia fetida through dermal contact.

PubMed

Gong, Ping; Escalon, B Lynn; Hayes, Charolett A; Perkins, Edward J

2008-02-01

The explosive compound hexanitrohexaazaisowurtzitane (CL-20) has been shown to cause both lethal and sublethal (reproductive and neurotoxic) effects in exposed oligochaetes. However, whether worms take up CL-20 and how much CL-20 enters worm bodies leading to toxicity (e.g., lethality) remain to be determined. In the present study, we used high performance liquid chromatography (HPLC) and radiolabeled tracer methods to investigate the CL-20 uptake in the whole worm body after contact exposures. Worms (Eisenia fetida) were exposed to filter paper spiked with non-radioactive or [U-(14)C]-labeled CL-20 for 1-3 d. The radiolabeled tracer method allowed us to detect the parent compound and transformation products in worms exposed to as low as 0.04 microg CL-20 cm(-2) of filter paper. The HPLC method without radiolabeled tracer was far less sensitive with a detection limit of 2.17 microg CL-20 cm(-2). Using the radiolabeled tracer, we were able to demonstrate that the worm body concentration linearly correlated to the filter paper concentration < or =0.34 microg cm(-2) (r=0.94) if no breakdown products are assumed. At higher concentrations, the body concentration increased slowly and saturated at around 11 microg g(-1) dry mass resulting in an estimated lethal critical body burden of 10-15 microg CL-20 g(-1) dry mass. These findings demonstrate that CL-20 or potential transformation products are taken into the earthworm body through dermal contact. This information should prove valuable in assessing the bioaccumulation potential and ecological risks of CL-20.

Infrapopulations of Gyliauchen volubilis Nagaty, 1956 (Trematoda: Gyliauchenidae) in the rabbitfish Siganus rivulatus (Teleostei: Siganidae) from the Saudi coast of the Red Sea.

PubMed

Al-Jahdali, M O

2012-08-01

In hermaphroditic helminth parasites, infrapopulation size or mating group size mostly affects some processes acting within the infrapopulation. Here, 30 natural infrapopulations (12-154 individuals) of the intestinal trematode Gyliauchen volubilis Nagaty, 1956 from the fish Siganus rivulatus consisting of newly excysted juveniles, immature and mature worms were found distributed in a well-defined fundamental niche (anterior 40% of the intestine). In small infrapopulations, all stages of the parasite were alive. In larger infrapopulations, differential mortality was only and consistently observed among newly excysted juveniles, and gradually increased to include most or all juveniles in the largest infrapopulations. Among mature worms, the mean worm length seemed unaffected by the infrapopulation size. However, the ratio mean testis size-mean ovary size, a reliable indicator of resource allocation to the male function and of opportunities for cross fertilization, significantly increased with mating group size. In small infrapopulations, all stages of the parasite were scattered along the niche, and never seen in mating pairs (possibly reproduced by self-fertilization). In larger infrapopulations, newly excysted juveniles and immature worms were scattered along the anterior two thirds of the niche, while mature worms were constantly found aggregated in its posterior third (narrow microhabitat), where some were arranged in mating pairs. The probability of mating reciprocally or unilaterally was dependent on body size. The mean number of uterine eggs per worm significantly decreased and their mean sizes significantly increased with mating group size. The results are statistically significant and suggest that infrapopulation self-regulation is greatly associated with its size.

Highly sensitive avoidance plays a key role in sensory adaptation to deep-sea hydrothermal vent environments.

PubMed

Ogino, Tetsuya; Maegawa, Shingo; Shigeno, Shuichi; Fujikura, Katsunori; Toyohara, Haruhiko

2018-01-01

The environments around deep-sea hydrothermal vents are very harsh conditions for organisms due to the possibility of exposure to highly toxic compounds and extremely hot venting there. Despite such extreme environments, some indigenous species have thrived there. Alvinellid worms (Annelida) are among the organisms best adapted to high-temperature and oxidatively stressful venting regions. Although intensive studies of the adaptation of these worms to the environments of hydrothermal vents have been made, little is known about the worms' sensory adaptation to the severe chemical conditions there. To examine the sensitivity of the vent-endemic worm Paralvinella hessleri to low pH and oxidative stress, we determined the concentration of acetic acid and hydrogen peroxide that induced avoidance behavior of this worm, and compared these concentrations to those obtained for related species inhabiting intertidal zones, Thelepus sp. The concentrations of the chemicals that induced avoidance behavior of P. hessleri were 10-100 times lower than those for Thelepus sp. To identify the receptors for these chemicals, chemical avoidance tests were performed with the addition of ruthenium red, a blocker of transient receptor potential (TRP) channels. This treatment suppressed the chemical avoidance behavior of P. hessleri, which suggests that TRP channels are involved in the chemical avoidance behavior of this species. Our results revealed for the first time hypersensitive detection systems for acid and for oxidative stress in the vent-endemic worm P. hessleri, possibly mediated by TRP channels, suggesting that such sensory systems may have facilitated the adaptation of this organism to harsh vent environments.

Infection levels of the eyeworm Oxyspirura petrowi and caecal worm Aulonocephalus pennula in the northern bobwhite and scaled quail from the Rolling Plains of Texas.

PubMed

Dunham, N R; Peper, S T; Downing, C; Brake, E; Rollins, D; Kendall, R J

2017-09-01

Northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) have experienced chronic declines within the Rolling Plains ecoregion of Texas. Parasitic infection, which has long been dismissed as a problem in quail, has not been studied thoroughly until recently. A total of 219 northern bobwhite and 101 scaled quail from Mitchell County, Texas were captured and donated from 2014 to 2015, and examined for eyeworm (Oxyspirura petrowi) and caecal worm (Aulonocephalus pennula) infections. In 2014, bobwhites averaged 19.6 ± 1.8 eyeworms and 98.6 ± 8.2 caecal worms, and 23.5 ± 2.1 eyeworms and 129.9 ± 10.7 caecal worms in 2015. Scaled quail averaged 4.8 ± 1.0 eyeworms and 50 ± 6.8 caecal worms in 2014, and 5.7 ± 1.3 eyeworms and 38.1 ± 7.1 caecal worms in 2015. This study expands the knowledge of parasitic infection in quail inhabiting the Rolling Plains of Texas. A significant difference was documented in O. petrowi infection between species but there was no significant difference in A. pennula between quail species. No significant difference was detected in parasite infection between the sexes of both northern bobwhite and scaled quail. This study also documented the highest reported O. petrowi infection in both species of quail. Additional research is needed on the life history and infection dynamics of O. petrowi and A. pennula infections to determine if there are individual- and/or population-level implications due to parasitic infection.

Selenium Status Alters the Immune Response and Expulsion of Adult Heligmosomoides bakeri Worms in Mice

PubMed Central

Cheung, Lumei; Beshah, Ethiopia; Shea-Donohue, Terez; Urban, Joseph F.

2013-01-01

Heligmosomoides bakeri is a nematode with parasitic development exclusively in the small intestine of infected mice that induces a potent STAT6-dependent Th2 immune response. We previously demonstrated that host protective expulsion of adult H. bakeri worms from a challenge infection was delayed in selenium (Se)-deficient mice. In order to explore mechanisms associated with the delayed expulsion, 3-week-old female BALB/c mice were placed on a torula yeast-based diet with or without 0.2 ppm Se, and after 5 weeks, they were inoculated with H. bakeri infective third-stage larvae (L3s). Two weeks after inoculation, the mice were treated with an anthelmintic and then rested, reinoculated with L3s, and evaluated at various times after reinoculation. Analysis of gene expression in parasite-induced cysts and surrounding tissue isolated from the intestine of infected mice showed that the local-tissue Th2 response was decreased in Se-deficient mice compared to that in Se-adequate mice. In addition, adult worms recovered from Se-deficient mice had higher ATP levels than worms from Se-adequate mice, indicating greater metabolic activity in the face of a suboptimal Se-dependent local immune response. Notably, the process of worm expulsion was restored within 2 to 4 days after feeding a Se-adequate diet to Se-deficient mice. Expulsion was associated with an increased local expression of Th2-associated genes in the small intestine, intestinal glutathione peroxidase activity, secreted Relm-β protein, anti-H. bakeri IgG1 production, and reduced worm fecundity and ATP-dependent metabolic activity. PMID:23649095

Still and Moving Image Evidences for Mating of Echinococcus granulosus Reared in Culture Media.

PubMed

Mohammadzadeh, Tahereh; Sadjjadi, Seyed Mahmoud; Rahimi, Hamidreza

2014-03-01

Echinococcus granulosus cultivation is very important for improvement of different aspect of medical and veterinary researches. Despite many advances in this case, there is a missing link for in vitro life cycle of adult worms and it is fertilization. Regarding the researchers' observations, self-fertilization can be done in worms living in dog intestine, but despite all sorts of experimental techniques, this phenomenon has never been observed in reared worms in culture media. Furthermore, cross fertilization has not been observed in vitro and even in parasites with dog intestinal origin; although it theoretically is possible. During a follow-up of cultivated adult worms, evidences of behaviors similar to self-mating (Type 2) and cross-mating were observed in our lab which will be presented here. Protoscoleces were aseptically removed from sheep hydatid cysts, washed twice with PBS and then cultivated in S.10E.H culture medium. The stages of parasite growth were observed using an inverted microscope for two months and all stages and behaviors were microscopically photographed. Different movies have also been made from these behavioral features. After around 55 days post cultivation, some evidences of behaviors similar to self-mating (Type 2) and cross-mating were observed in some of the mature adult worms. However, fertile eggs in these parasites have never been observed. Regarding the above observations, these parasites show tendency to unsuccessful self-mating/fertilization (type 2) which failure could be due to anatomical position and physiological maturation. Also lack of suitable conditions for self-fertilization causes the worms try to do unsuccessful cross- mating/fertilization in culture media.

A reversible bipolar WORM device based on AlOxNy thin film with Al nano phase embedded

NASA Astrophysics Data System (ADS)

Zhu, W.; Li, J.; Zhang, L.; Hu, X. C.

2017-03-01

An Al-rich AlOxNy thin film based reversible Write-Once-Read-Many-Times (WORM) memory device with MIS structure could transit from high resistance state (HRS, ∼1011 Ω) to low resistance state (LRS, ∼105 Ω) by sweeping voltage up to ∼20 V. The first switching could be recorded as writing process for WORM device which may relate to conductive path are formed through the thin film. The conductive path should be formed by both Al nano phase and oxygen vacancies. Among of them, Al nano phases are not easy to move, but oxygen vacancies could migrate under high E-field or at high temperature environment. Such conductive path is not sensitive to charging effect after it formed, but it could be broken by heating effect, which may relate to the migration of excess Al ions and oxygen vacancies at high temperature. After baking LRS (ON state) WORM device at 200 °C for 2 min, the conductivity will decrease to HRS which indicates conductive path is broken and device back to HRS (OFF state) again. This phenomenon could be recorded as recovery process. Both writing and recovery process related to migration of oxygen vacancies and could be repeated over 10 times in this study. It also indicates that there is no permanent breakdown occurred in MIS structured WORM device operation. We suggest that this conductive path only can be dissolved by a temperature sensitive electro-chemical action. This WORM device could maintain at LRS over 105 s with on-off ratio over 4 orders.