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Sample records for amphipod gammarus tigrinus

  1. Natural organic matter (NOM) induces oxidative stress in freshwater amphipods Gammarus lacustris Sars and Gammarus tigrinus (Sexton).

    PubMed

    Timofeyev, Maxim A; Shatilina, Zhanna M; Kolesnichenko, Aleksey V; Bedulina, Darya S; Kolesnichenko, Viktoria V; Pflugmacher, Stephan; Steinberg, Christian E W

    2006-08-01

    Humic substances comprise the majority of natural organic matter (NOM) on Earth, including dissolved organic matter in freshwater systems. Recent studies show that these substances directly interact with aquatic organisms as chemical stressors. The aim of the present study was to investigate the mode of action of dissolved NOM on the freshwater amphipods Gammarus lacustris Sars and Gammarus tigrinus (Sexton), and in particular, to determine if NOM induces or promotes internal oxidative stress. NOM was isolated by reverse osmosis from a brown-water lake in Brandenburg State, Germany. Oxidative stress markers, such as lipid peroxidation, cell internal hydrogen peroxide concentration, as well as peroxidase, catalase and glutathione S-transferase activities, were quantified. Exposure of both amphipod species to NOM caused a significant increase in lipid peroxidation, hydrogen peroxide concentration, catalase, peroxidase and glutathione S-transferase activities. Both species showed a two-stage antioxidant response: the first stage allowed the organisms to effectively eliminate ROS and to protect cells from damage, whereas the second stage leads to H2O2 accumulation in combination with destruction of lipid structures in the cells and, finally, functional damage or even death of the organism. PMID:16542708

  2. High fecundity and predation pressure of the invasive Gammarus tigrinus cause decline of indigenous gammarids

    NASA Astrophysics Data System (ADS)

    Jänes, Holger; Kotta, Jonne; Herkül, Kristjan

    2015-11-01

    The North American amphipod Gammarus tigrinus is one of the most aggressive invaders recently expanding its distribution in the European waters. The species was detected in the north-eastern Baltic Sea in 2003 and has rapidly expanded its distribution ever since. This invasive amphipod has been notably successful in shallow, soft and mixed bottom habitats becoming one of the most abundant gammarid colonizing such environments. This study carried out two experiments: (1) an outdoor aquarium experiment to assess interspecific competition among the invasive G. tigrinus and the native Gammarus duebeni and compare their reproductive potential, and (2) an in situ meshbag experiment to determine the effect of adult G. tigrinus and native gammarids on juvenile gammarid amphipods. These demonstrated that the adult G. tigrinus had no effects on the adult G. duebeni; however, the invasive amphipod had higher reproductive potential compared to the native species such as G. duebeni. Moreover, almost all adult gammarids exerted a significant predation pressure on juvenile amphipods. Thus, the combined effect of predation on juvenile amphipods and large brood production of G. tigrinus could be plausible explanations describing increased abundance of G. tigrinus and decrease of local gammarid populations in the north-eastern Baltic Sea but plausibly in similar shallow water habitats in other seas.

  3. Embryonic transcriptome of the brackishwater amphipod Gammarus chevreuxi.

    PubMed

    Truebano, Manuela; Tills, Oliver; Spicer, John I

    2016-08-01

    Environmental change can dramatically alter the development of aquatic organisms. While the effect of such change on physiological and morphological ontogenies is becoming clearer, the molecular mechanisms underpinning them are largely unexplored. Characterizing these mechanisms is often limited by the lack of molecular resources. We have applied Illumina HiSeq sequencing to RNA isolated from different developmental stages of the brackishwater amphipod Gammarus chevreuxi. Over 52.6M paired-end reads were assembled de novo into 172,081 contigs, representing 118,812 potential genes. The assembly generated constitutes a reference embryonic transcriptome for an ecologically-important aquatic shredder species. This resource will contribute to our understanding of the mechanisms underpinning the development of physiological function through functional, comparative and quantitative expression studies. It will also allow the identification of candidate biomarkers for assessing the impact of environmental stressors in estuarine systems. PMID:26896099

  4. Responses of the brackish-water amphipod Gammarus duebeni (crustacea) to saline sewage

    NASA Astrophysics Data System (ADS)

    Jones, M. B.; Johnson, I.

    Soon after the openiing of the Looe sewage treatment works (Cornwall, southwest England) in 1973, it became colonized by the brackish-water amphipod Gammarus duebeni Liljeborg. The works is unusual as it operates with saline sewage and has a tidally-based pattern of salinity fluctuation (S=13 to 34). Various responses of this unique amphipod population (sewage amphipods) have been compared with G. duebeni from the adjacent Looe River estuary (estuarine amphipods) in an attempt to identify long-term responses to sewage. Sewage amphipods were significantly smaller than their estuarine equivalents; the sewage population was biased significantly to males, whereas the sex ratio of the estuarine population significantly favours females. Compared with the estuary, the consistently lower oxygen levels in the works were reflected in significant differences in metabolism. Sewage amphipods maintained high levels of activity under hypoxia ( e.g. swimming), and the higher survival and lower rates of lactic acid accumulation under anoxia than estuarine individuals. In addition, sewage amphipods recovered more rapidly from anoxia and had a lower critical oxygen tension (p c) than estuarine amphipods. Sewage amphipods are exposed to higher levels of heavy metals associated with the domestic sewage and zinc concentrations are particularly elevated in the works. Exposure to elevated zinc concentrations resulted in similar patterns of body zinc uptake for sewage and estuarine Gammarus at high (30) and low (10) salinity, with zinc regulation apparently occuring to an external threshold of 200 γmgZn·dm -3. No consistent interpopulational differences in the effect ofzinc on zinc uptake or on osmoregulation have been identified. However, sewage amphipods had higher survival at all zinc/salinity combinations compared with estuarine individuals. These indicate that sewage amphipods are adapted to the unusual combination of conditions prevailing in the treatment works and, if reproductive

  5. Increased RO concentrate toxicity following application of antiscalants - acute toxicity tests with the amphipods Gammarus pulex and Gammarus roeseli.

    PubMed

    Feiner, Mona; Beggel, Sebastian; Jaeger, Nadine; Geist, Juergen

    2015-02-01

    In reverse osmosis, a frequently used technology in water desalination processes, wastewater (RO concentrate) is generated containing the retained solutes as well as so-called antiscalants (AS), i.e. chemical substances that are commonly applied to prevent membrane-blocking. In this study, a risk assessment of a possible discharge of concentrate into a small stream was conducted. The acute toxicity of two concentrates containing two different ASs and of concentrate without AS to the amphipods Gammarus pulex and Gammarus roeseli was studied. Mortality of gammarids exposed to the concentrate without AS was not different to the control, whereas concentrates including ASs caused mortality rates up to 100% at the highest test concentrations after 168 h. Resulting EC50-values were 36.2-39.4% (v/v) after 96 h and 26.6-58.0% (v/v) after 168 h. These results suggest that the ecotoxicological relevance of antiscalants is greater than currently assumed. PMID:25476491

  6. Transcriptome of the freshwater amphipod Gammarus pulex hepatopancreas.

    PubMed

    Gismondi, E; Thomé, J P

    2016-06-01

    So far, ecotoxicological studies used biomarkers of exposure or of effects in order to investigate the impacts of contaminated areas on biota (Peakall, 1994 [6]). However, although these results are important in the ecotoxicological risk assessment, biomarkers are very specific and only provide information on the biological processes or physiological pathways targeted by the biomarkers experimenters choose to test (Monsinjon and Knigge, 2007 [5]). In recent years, proteomics have become a major tool in ecotoxicology, as they provide a global insight into the mechanism of action of pollutants without the need of hypothesis testing or any preconception on the biological processes likely impacted (Gismondi et al., 2015; Trapp et al., 2015 [7]; Truebano, 2016 [8]). However, the analysis of proteomic results is often limited due to the lack of database, especially for non-model organisms, such as Gammarus sp, commonly used as biological model in ecotoxicology (Sornom et al., 2012 [11]; Vellinger et al., 2013 [9]; Gismondi and Thomé, 2014 [1]; Lebrun et al., 2014 [3]). Here, we performed Illumina HiSeq sequencing to total RNA isolated from the hepatopancreas (i.e. detoxification tissue) of Gammarus pulex males and females coming from uncontaminated river and contaminated river (e.g. PCB, benzo(a)pyrene). Approximately 290 M paired-end reads were assembled, filtered and sorted into 39,801 contigs whose 10.878 were similar of proteins available in databases. The assembled contigs could represent a reference hepatopancreas transcriptome for G. pulex, and constitute an important resource for future investigations on the impacts of pollutants on invertebrate biota, since it would improve the understanding of the mechanisms of action involved in toxicity. In addition, the hepatopancreas transcriptome will also allow the identification of new potential biomarkers for the ecotoxicological risk assessments. Assembled contigs were deposited in the European Nucleotide Archive

  7. Phylogeography and environmental diversification of a highly adaptable marine amphipod, Gammarus duebeni.

    PubMed

    Rock, J; Ironside, J; Potter, T; Whiteley, N M; Lunt, D H

    2007-07-01

    Genetic diversity and phylogeographic population structure in the gammarid amphipod, Gammarus duebeni, were investigated across its broad latitudinal distribution in the NE and NW Atlantic by analysis of mitochondrial DNA sequence. Gammarus duebeni has exceptional tolerance of salinity change and inhabits environments ranging from marine to freshwater. The longstanding debate on whether there are distinct marine and freshwater subspecies was assessed by sampling populations from sites characterized by different salinities. Our sequence data demonstrates that there are two major lineages, with little internal geographic structuring. Evidence is provided to suggest a pre-glacial divergence of these two clades, involving segregation between a region historically associated with the freshwater form and the majority of the marine localities on both sides of the Atlantic. A modern contact zone between the marine and freshwater forms is proposed in western Britain. PMID:17426729

  8. Distribution of Amphipods (Gammarus nipponensis Ueno) Among Mountain Headwater Streams with Different Legacies of Debris Flow Occurrence

    EPA Science Inventory

    To understand the impacts of debris flows on the distribution of an amphipod with limited dispersal ability in the context of stream networks, we surveyed the presence of Gammarus nipponensis in 87 headwater streams with different legacies of debris flow occurrence within an 8.5-...

  9. The subtle effects of sea water acidification on the amphipod Gammarus locusta

    NASA Astrophysics Data System (ADS)

    Hauton, C.; Tyrrell, T.; Williams, J.

    2009-01-01

    We report an investigation of the effects of increases in pCO2 on the growth and molecular physiology of the neritic amphipod Gammarus locusta, which has a cosmopolitan distribution in estuaries. Amphipods were reared from juvenile to mature adult in laboratory microcosms at three different levels of pH in nominal range 8.1-7.6. Growth rate was estimated from weekly measures of body length. At sexual maturity the amphipods were sacrificed and assayed for changes in the expression of genes coding for a heat shock protein (hsp70 gene) and the metabolic enzyme glyceraldehyde-3-phosphate dehydrogenase (gapdh gene). The data show that the growth and survival rate of this species is not significantly impacted by a decrease in sea water pH of up to 0.5 units. Quantitative real-time PCR analysis indicated that there was no significant effect of growth in acidified sea water on the expression of the hsp70 gene. However, there was a consistent and significant increase in the expression of the gapdh gene at a pH of ~7.5 which indicated a possible disruption to oxidative metabolic processes. It was concluded that future predicted changes in sea water pH may have subtle effects on the physiology and metabolism of coastal and marine species which may be overlooked in studies of whole organism response.

  10. An acanthocephalan parasite increases the salinity tolerance of the freshwater amphipod Gammarus roeseli (Crustacea: Gammaridae)

    NASA Astrophysics Data System (ADS)

    Piscart, Christophe; Webb, Dennis; Beisel, Jean Nicolas

    2007-09-01

    Studies of the influence of parasites on host fitness generally conclude that parasites have a strong negative effect on their hosts. In this study, we have investigated experimentally the role of Polymorphus minutus, an acanthocephalan parasite, on the salinity tolerance of the freshwater amphipod Gammarus roeseli, one of its intermediate hosts. Unexpectedly, P. minutus-infected gammarids were more tolerant to salinity stress than uninfected ones. The mean lethal salt concentrations for 50% mortality of hosts tested were 17.3 (infected) and 9.7 g/L (uninfected). The parasitic load (one or two parasites per host) did not affect the result. The size of hosts had no significant influence on the salinity tolerance of either infected or uninfected gammarids. The mobility of all types of gammarid decreased when the salinity exceeded 9.0 g/L, but there was no significant difference between infected and uninfected gammarids. We discuss the higher salinity tolerance of infected amphipods in relation to O2 consumption and osmoregulation. Finally, we demonstrate that the salinity tolerance is enhanced in the parasitized amphipod but without a significant change in behavior or an osmoregulatory adjustment.

  11. An acanthocephalan parasite increases the salinity tolerance of the freshwater amphipod Gammarus roeseli (Crustacea: Gammaridae).

    PubMed

    Piscart, Christophe; Webb, Dennis; Beisel, Jean Nicolas

    2007-09-01

    Studies of the influence of parasites on host fitness generally conclude that parasites have a strong negative effect on their hosts. In this study, we have investigated experimentally the role of Polymorphus minutus, an acanthocephalan parasite, on the salinity tolerance of the freshwater amphipod Gammarus roeseli, one of its intermediate hosts. Unexpectedly, P. minutus-infected gammarids were more tolerant to salinity stress than uninfected ones. The mean lethal salt concentrations for 50% mortality of hosts tested were 17.3 (infected) and 9.7 g/L (uninfected). The parasitic load (one or two parasites per host) did not affect the result. The size of hosts had no significant influence on the salinity tolerance of either infected or uninfected gammarids. The mobility of all types of gammarid decreased when the salinity exceeded 9.0 g/L, but there was no significant difference between infected and uninfected gammarids. We discuss the higher salinity tolerance of infected amphipods in relation to O(2) consumption and osmoregulation. Finally, we demonstrate that the salinity tolerance is enhanced in the parasitized amphipod but without a significant change in behavior or an osmoregulatory adjustment. PMID:17487466

  12. Proteogenomics of Gammarus fossarum to Document the Reproductive System of Amphipods*

    PubMed Central

    Trapp, Judith; Geffard, Olivier; Imbert, Gilles; Gaillard, Jean-Charles; Davin, Anne-Hélène; Chaumot, Arnaud; Armengaud, Jean

    2014-01-01

    Because of their ecological importance, amphipod crustacea are employed worldwide as test species in environmental risk assessment. Although proteomics allows new insights into the molecular mechanisms related to the stress response, such investigations are rare for these organisms because of the lack of comprehensive protein sequence databases. Here, we propose a proteogenomic approach for identifying specific proteins of the freshwater amphipod Gammarus fossarum, a keystone species in European freshwater ecosystems. After deep RNA sequencing, we created a comprehensive ORF database. We identified and annotated the most relevant proteins detected through a shotgun tandem mass spectrometry analysis carried out on the proteomes from three major tissues involved in the organism's reproductive function: the male and female reproductive systems, and the cephalon, where different neuroendocrine glands are present. The 1,873 mass-spectrometry-certified proteins represent the largest crustacean proteomic resource to date, with 218 proteins being lineage specific. Comparative proteomics between the male and female reproductive systems indicated key proteins with strong sexual dimorphism. Protein expression profiles during spermatogenesis at seven different stages highlighted the major gammarid proteins involved in the different facets of reproduction. PMID:25293947

  13. The subtle effects of sea water acidification on the amphipod Gammarus locusta

    NASA Astrophysics Data System (ADS)

    Hauton, C.; Tyrrell, T.; Williams, J.

    2009-08-01

    We report an investigation of the effects of increases in pCO2 on the survival, growth and molecular physiology of the neritic amphipod Gammarus locusta which has a cosmopolitan distribution in estuaries. Amphipods were reared from juvenile to mature adult in laboratory microcosms at three different levels of pH in nominal range 8.1-7.6. Growth rate was estimated from weekly measures of body length. At sexual maturity the amphipods were sacrificed and assayed for changes in the expression of genes coding for a heat shock protein (hsp70 gene) and the metabolic enzyme glyceraldehyde-3-phosphate dehydrogenase (gapdh gene). The data show that the growth and survival of this species is not significantly impacted by a decrease in sea water pH of up to 0.5 units. Quantitative real-time PCR analysis indicated that there was no significant effect of growth in acidified sea water on the sustained expression of the hsp70 gene. There was a consistent and significant increase in the expression of the gapdh gene at a pH of ~7.5 which, when combined with observations from other workers, suggests that metabolic changes may occur in response to acidification. It is concluded that sensitive assays of tissue physiology and molecular biology should be routinely employed in future studies of the impacts of sea water acidification as subtle effects on the physiology and metabolism of coastal marine species may be overlooked in conventional gross "end-point" studies of organism growth or mortality.

  14. Life History and Reproductive Timing of the Endangered Illinois Cave Amphipod, Gammarus acherondytes

    NASA Astrophysics Data System (ADS)

    Venarsky, M. P.; Wilhelm, F. M.; Anderson, F. A.; Taylor, S. J.

    2005-05-01

    To aid the recovery of endangered species requires an understanding of their basic biology. Armed with such knowledge, meaningful management plans with realistic objectives can be established. We examined the life history and reproductive biology of Gammarus acherondytes, a federally endangered cave amphipod, in Reverse Stream, Monroe Co., Illinois. The population was sampled non-destructively at monthly intervals from October 2003 to February 2005. The density of gravid females peaked twice annually, (November-December and June-July) indicating major reproductive events. Gravid females also occurred at other times of the year but at low densities. Two major peaks in the density of newborn young were also observed, which lagged the density of gravid females by approximately 1-2 months. We believe this reproductive pattern is related to the influx of organic matter from mid summer storm events and leaf abscission in autumn. Young grew at a rate of 0.034 mm/day and likely reach reproductive size in one year. Adults are iteroparous and may live for several years. Our results suggest that limiting cave access in highly visited caves during peak reproduction may be a simple strategy to increase the abundance of G. acherondytes.

  15. Impact of an estrogenic sewage treatment plant effluent on life-history traits of the freshwater amphipod Gammarus pulex.

    PubMed

    Schneider, Ilona; Oehlmann, Jörg; Oetken, Matthias

    2015-01-01

    Despite efforts to upgrade sewage treatment plants (STPs) in the last decades, STPs are still a major source for the contamination of surface waters, including emerging pollutants such as pesticides, pharmaceuticals, personal care products and endocrine disrupting chemicals (EDCs). Because many of these substances are not completely removed in conventional STPs they are regularly detected in surface waters where they have the potential to affect local macroinvertebrate communities. The objective of the current work was to investigate the impact of an estrogenic wastewater effluent on the key life-history traits of the freshwater amphipod Gammarus pulex. G. pulex was exposed in artificial indoor flow-channels under constant conditions to different wastewater concentrations (0%, 33%, 66%, 100%). In parallel the estrogenic activity of wastewater samples was determined using the yeast estrogen screen (YES). Estrogenic activities in the STP effluent were up to 38.6 ng/L estradiol equivalents (EEQ). Amphipods exhibited an increasing body length with increasing wastewater concentrations. Furthermore, we observed a shift of the sex ratio in favour of females, a significantly increased fraction of brooding females and increased fecundity indices with increasing wastewater concentrations. The increased body length is likely to be attributed to the additional nutrient supply while the occurrence of EDCs in the wastewater is the probable cause for the altered sex ratio and fecundity in exposed Gammarus cohorts. PMID:25594120

  16. Habitat segregation mediates predation by the benthic fish Cottus gobio on the exotic amphipod species Gammarus roeseli

    NASA Astrophysics Data System (ADS)

    Kaldonski, Nicolas; Lagrue, Clément; Motreuil, Sébastien; Rigaud, Thierry; Bollache, Loïc

    2008-09-01

    Predation is often considered as one of the most important biotic factor determining the success of exotic species. The freshwater amphipod Gammarus roeseli has widely colonized Western Europe, where it is frequently found in sympatry with the native species ( Gammarus pulex). Previous laboratory experiments revealed that G. roeseli may have an advantage over G. pulex through differential predation by native fish (brown trout). Morphological anti-predator defences (spines) were found responsible for lower rates of predation on the invasive G. roeseli. Here, using both field surveys and laboratory experiments, we tested if a differential of predation exists with other fish predators naturally encountered by gammarids. The main predators present in our field site were nocturnal benthic feeders (mainly bullheads, Cottus gobio). Fish diet analysis showed that, compared to its global availability in the river, G. roeseli was less consumed than G. pulex. In the field, however, G. roeseli was found mainly in the aquatic vegetation whereas G. pulex was found in all habitat types. Laboratory experiments in microcosms revealed that G. roeseli was less prone to predation by C. gobio only when vegetation was present. Depending on the type of predator, the differential of predation could therefore be mediated by antipredator behaviour, and a better usage of refuges, rather than by morphological defences.

  17. Multi-level assessment of chronic toxicity of estuarine sediments with the amphipod Gammarus locusta: I. Biochemical endpoints.

    PubMed

    Neuparth, Teresa; Correia, Ana D; Costa, Filipe O; Lima, Gláucia; Costa, Maria Helena

    2005-07-01

    We report on biomarker responses conducted as part of a multi-level assessment of the chronic toxicity of estuarine sediments to the amphipod Gammarus locusta. A companion article accounts for organism and population-level effects. Five moderately contaminated sediments from two Portuguese estuaries, Sado and Tagus, were assessed. Three of them were muddy and two were sandy sediments. The objective was to assess sediments that were not acutely toxic. Three of the sediments met this criterion, the other two were diluted (50% and 75%) with clean sediment until acute toxicity was absent. Following 28-d exposures, the amphipods were analysed for whole-body metal bioaccumulation, metallothionein induction (MT), DNA strand breakage (SB) and lipid peroxidation (LP). Two of the muddy sediments did not cause chronic toxicity. These findings were consistent with responses at organism and population levels that showed higher growth rates and improvement of reproductive traits for amphipods exposed to these two sediments. Two other sediments, one muddy and one sandy, exhibited pronounced chronic toxicity, affecting SB, MT induction (in muddy sediment), survival and reproduction. Potential toxicants involved in these effects were identified. The last sandy sediment exhibited some loss of DNA integrity, however growth was also enhanced. Present results, together with the organism/population-level data, and also benthic communities information, were analysed under a weight-of-evidence approach. By providing evidence of exposure (or lack of it) to contaminants in sediments, the biomarkers here applied assisted in distinguishing toxicants' impacts in test organisms from the confounding influence of other geochemical features of the sediments. PMID:15649528

  18. Does the presence of titanium dioxide nanoparticles reduce copper toxicity? A factorial approach with the benthic amphipod Gammarus fossarum.

    PubMed

    Rosenfeldt, Ricki R; Seitz, Frank; Zubrod, Jochen P; Feckler, Alexander; Merkel, Tobias; Lüderwald, Simon; Bundschuh, Rebecca; Schulz, Ralf; Bundschuh, Mirco

    2015-08-01

    In aquatic ecosystems, titanium dioxide nanoparticles (nano-TiO2) may adsorb co-occurring chemical stressors, such as copper (Cu). This interaction has the potential to reduce the concentration of dissolved Cu due to surface binding to the nanoparticles. The subsequent sedimentation of nano-TiO2 agglomerates may increase the exposure of benthic species towards the associated Cu. This scenario was assessed by employing the amphipod Gammarus fossarum as model species and taking advantage of a 2×2-factorial design investigating absence and presence of 2mg nano-TiO2/L and 40μg Cu/L (n=45; t=24d) in darkness, respectively. Nano-TiO2 alone did not affect mortality and leaf consumption, whereas Cu alone caused high mortality (>70%), reduced leaf consumption (25%) and feces production (30%) relative to the control. In presence of nano-TiO2, Cu-induced toxicity was largely eliminated. However, independent of Cu, nano-TiO2 decreased the gammarids' assimilation and weight. Hence, nano-TiO2 may be applicable as Cu-remediation agent, while its potential long-term effects need further attention. PMID:26037100

  19. Changes in antitoxic defense systems of the freshwater amphipod Gammarus pulex exposed to BDE-47 and BDE-99.

    PubMed

    Horion, Sibylle; Thomé, Jean-Pierre; Gismondi, Éric

    2015-05-01

    Polybrominated diphenyl ethers (PBDEs) are emerging pollutants widely distributed in aquatic environment. Although the bioaccumulation of this compound has been well studied, few studies have investigated their impacts on antitoxic systems of invertebrates, considering both genders. Here, we have evaluated the effects of BDE-47 and BDE-99 congeners on the antitoxic defence systems of the freshwater amphipod Gammarus pulex, and especially on the multixenobiotic resistance (MXR) activity, as well as the activities of two antitoxic enzymes, the glutathione-S-transferase (GST) and the glutathione peroxidases (GPx). Results revealed that BDE-47 and BDE-99 have inhibited the MXR activity whatever the gammarid gender, which could lead to a reduction of the pollutant elimination from the organism. In addition, a gender-biased response and a congener-biased effect on the antitoxic enzymes activities were observed. Indeed, both BDE congener exposures increased the GST activity in males, whereas in females, only BDE-99 congener modified this activity by decreasing it. On the contrary, BDE exposures did not impact the GPx activity in females, while in males BDE-99 has increased it. Results of the present study highlight that a PBDE exposure at 0.1 µg L(-1) modify antitoxic enzymes activities differently according to gender, which could lead to a change in G. pulex sensitivity on the long term. Finally, this work confirms the ecotoxicological implication of gender in the pollutant toxicity assessment, in order to evaluate impact on populations. PMID:25732806

  20. Comparison of arsenate and cadmium toxicity in a freshwater amphipod (Gammarus pulex).

    PubMed

    Vellinger, Céline; Parant, Marc; Rousselle, Philippe; Immel, Françoise; Wagner, Philippe; Usseglio-Polatera, Philippe

    2012-01-01

    Cadmium is largely documented on freshwater organisms while arsenic, especially arsenate, is rarely studied. The kinetic of the LC50s values for both metals was realized on Gammarus pulex. Physiological [i.e. metal concentration in body tissues, bioconcentration factor (BCF)] effects and behavioural responses (via pleopods beats) were investigated after 240-h exposure. Arsenate LC50 value was 100 fold higher than Cd-LC50 value after 240-h exposure, while concentrations in gammarids were similar for both metals at their respective LC50s. BCF decreased with increasing cadmium concentration while BCF remained stable with increasing arsenate concentration. Moreover, BCF was between 148 and 344 times lower for arsenate than cadmium. A significant hypoventilation was observed for cadmium concentrations exceeding or close to the 240h-LC50(Cd), while gammarids hyperventilated for the lowest arsenate concentrations and hypoventilated for the highest arsenate concentrations. We discussed the relationships between potential action mechanisms of these two metals and observed results. PMID:22035927

  1. Antagonistic toxicity of arsenate and cadmium in a freshwater amphipod (Gammarus pulex).

    PubMed

    Vellinger, Céline; Parant, Marc; Rousselle, Philippe; Usseglio-Polatera, Philippe

    2012-10-01

    Because toxicants rarely occur alone in the environment, a major challenge in risk assessment is to address the combined effects of chemicals on aquatic organisms. This work is aimed at investigating the joint toxicity action of binary mixtures of cadmium and arsenate on Gammarus pulex. Individuals were exposed during 240 h to four single arsenate or cadmium concentrations and binary mixtures of these metals according to a complete factorial plane. Observed mortality in binary mixtures was compared to observed mortality in single arsenate or cadmium exposures. In addition, interactive effects (antagonistic, additive or synergistic) were evaluated using a predictive model for the theoretically expected interactive effect of chemicals. For all the tested concentration combinations, we observed an antagonist 'between-metals' interaction on G. pulex mortality. This antagonistic effect was more marked for the lowest than for the highest (i.e. 1502.0 μg(AsV) L(-1) and 28.5 μg(Cd) L(-1)) tested concentrations of individual metals in binary mixtures. Metal concentrations in body tissues were evaluated and were significantly lower in binary mixtures than in single metal exposures at similar concentration, especially for combinations corresponding to the highest concentrations of both metals (1502.0 μg(AsV) L(-1) and 28.5 μg(Cd) L(-1)). Results were discussed in terms of (1) mechanisms of uptake and bioconcentration and (2) relationships between metal concentration in gammarid body and observed toxicity. PMID:22535317

  2. Impact of natural organic matter (NOM) on freshwater amphipods.

    PubMed

    Timofeyev, Maxim A; Wiegand, Claudia; Kent Burnison, B; Shatilina, Zhanna M; Pflugmacher, Stephan; Steinberg, Christian E W

    2004-02-01

    Natural organic matter (NOM) isolated from the eutrophic Sanctuary Pond (Point Pelee National Park, Canada) has an adverse impact on amphipod species (Gammarus tigrinus and Chaetogammarus ischnus from Lake Müggelsee, Germany, and Eulimnogammarus cyaneus, from Lake Baikal, Russia). Increases in amphipod mortality, changes in peroxidase activity and increases of heat shock protein (hsp70) expression were observed upon exposure to NOM. The highest resistance to the adverse impact of NOM was observed with the endemic Baikalian amphipod E. cyaneus. However, the mechanisms behind this finding remains obscure. If differences in the sensitivity of the hsp70 antibody may be excluded, different modes of action may be postulated: because the adverse impact of NOM may be caused by reactive oxygen species (ROS) and the NOM itself, the observed differences may be due to the action of ROS alone (with E. cyaneus) and a combination of both adverse modes of action (European species). PMID:14967505

  3. Multi-level assessment of chronic toxicity of estuarine sediments with the amphipod Gammarus locusta: II. Organism and population-level endpoints.

    PubMed

    Costa, Filipe O; Neuparth, Teresa; Correia, Ana D; Costa, Maria Helena

    2005-07-01

    This study aimed to test the performance of the amphipod Gammarus locusta (L.) in chronic sediment toxicity tests. It constitutes part of a multi-level assessment of chronic toxicity of estuarine sediments, integrating organism and population-level endpoints with biochemical markers responses. Here we account for organism and population-level effects, while biomarker responses were reported in a companion article. Five moderately contaminated sediments from Sado and Tagus estuaries were tested, comprising 3 muddy and 2 sandy sediments. These sediments either did not show acute toxicity or were diluted with control sediment as much as required to remove acute toxicity. Subsequent chronic tests consisted of 28-day exposures with survival, individual growth and reproductive traits as endpoints. Two of the muddy sediments induced higher growth rates in the amphipods, and improved reproductive traits. This was understood to be a consequence of the amount of organic matter in the sediment, which was nutritionally beneficial to the amphipods, while concurrently decreasing contaminant bioavailability. Biomarker responses did not reveal toxicant-induced stress in amphipods exposed to these sediments. One of the sandy sediments was acutely toxic at 50% dilution, but in contrast stimulated amphipod growth when diluted 75%. This was presumed to be an indication of a hormetic response. Finally the two remaining contaminated sediments showed pronounced chronic toxicity, affecting survival and reproduction. The sex ratio of survivors was highly biased towards females, and offspring production was severely impaired. The particulars of the responses of this amphipod were examined, as well as strengths versus limitations of the sediment test. This study illustrates the utility of this chronic test for toxicity assessment of contaminated estuarine sediments, with potential application all along Atlantic Europe. PMID:15649529

  4. Ecological modelling and toxicity data coupled to assess population recovery of marine amphipod Gammarus locusta: Application to disturbance by chronic exposure to aniline.

    PubMed

    de los Santos, Carmen B; Neuparth, Teresa; Torres, Tiago; Martins, Irene; Cunha, Isabel; Sheahan, Dave; McGowan, Tom; Santos, Miguel M

    2015-06-01

    A population agent-based model of marine amphipod Gammarus locusta was designed and implemented as a basis for ecological risk assessment of chemical pollutants impairing life-history traits at the individual level. We further used the model to assess the toxic effects of aniline (a priority hazardous and noxious substance, HNS) on amphipod populations using empirically-built dose-response functions derived from a chronic bioassay that we previously performed with this species. We observed a significant toxicant-induced mortality and adverse effects in reproductive performance (reduction of newborn production) in G. locusta at the individual level. Coupling the population model with the toxicological data from the chronic bioassay allowed the projection of the ecological costs associated with exposure to aniline that might occur in wild populations. Model simulations with different scenarios indicated that even low level prolonged exposure to the HNS aniline can have significant long-term impacts on G. locusta population abundance, until the impacted population returns to undisturbed levels. This approach may be a useful complement in ecotoxicological studies of chemical pollution to transfer individual-collected data to ecological-relevant levels. PMID:25854699

  5. The Influence of the Disturbed Continuity of the River and the Invasive Species--Potamopyrgus antipodarum (Gray, 1843), Gammarus tigrinus (Sexton, 1939) on Benthos Fauna: A Case Study on Urban Area in the River Ruda (Poland).

    PubMed

    Spyra, Aneta; Kubicka, Justyna; Strzelec, Małgorzata

    2015-07-01

    The progressive degradation of aquatic ecosystems and ecohydrological role of rivers is one of the most important global environmental issues. The loss of the ability of rivers to self-purify waters due to the disturbances of river continuity cause a lack of biological life in parts of rivers or even in an entire river. The appearance of alien species in degraded aquatic environments is an increasingly common phenomenon and constitutes one of the threats to biodiversity. The aim of the study was to evaluate the possible impact of alien species Potamopyrgus antipodarum (Gray, 1843) and Gammarus tigrinus (Sexton, 1939) on native invertebrates as well as the influence of environmental factors on the occurrence benthos fauna including also alien species. The study conducted in industrial area, in the River Ruda (Poland), showed that at the sites at which the occurrence of the two alien species was observed, the density of native benthos and diversity decreased significantly. CCA analysis showed that non-native species occurred in fast water velocity and that their presence was associated with high values of conductivity, hardness, and a high chloride content. The arrival of new species from other geographical areas is one of the factors that influences the species balance in native aquatic fauna. The number of alien species in freshwater ecosystems probably will increase in the future as new aliens are moved outside of their native ranges. PMID:25868573

  6. The Influence of the Disturbed Continuity of the River and the Invasive Species— Potamopyrgus antipodarum (Gray, 1843), Gammarus tigrinus (Sexton, 1939) on Benthos Fauna: A Case Study on Urban Area in the River Ruda (Poland)

    NASA Astrophysics Data System (ADS)

    Spyra, Aneta; Kubicka, Justyna; Strzelec, Małgorzata

    2015-07-01

    The progressive degradation of aquatic ecosystems and ecohydrological role of rivers is one of the most important global environmental issues. The loss of the ability of rivers to self-purify waters due to the disturbances of river continuity cause a lack of biological life in parts of rivers or even in an entire river. The appearance of alien species in degraded aquatic environments is an increasingly common phenomenon and constitutes one of the threats to biodiversity. The aim of the study was to evaluate the possible impact of alien species Potamopyrgus antipodarum (Gray, 1843) and Gammarus tigrinus (Sexton, 1939) on native invertebrates as well as the influence of environmental factors on the occurrence benthos fauna including also alien species. The study conducted in industrial area, in the River Ruda (Poland), showed that at the sites at which the occurrence of the two alien species was observed, the density of native benthos and diversity decreased significantly. CCA analysis showed that non-native species occurred in fast water velocity and that their presence was associated with high values of conductivity, hardness, and a high chloride content. The arrival of new species from other geographical areas is one of the factors that influences the species balance in native aquatic fauna. The number of alien species in freshwater ecosystems probably will increase in the future as new aliens are moved outside of their native ranges.

  7. Effect of multiple microsporidian infections and temperature stress on the heat shock protein 70 (hsp70) response of the amphipod Gammarus pulex

    PubMed Central

    2014-01-01

    Background Increasing temperatures can be a significant stressor for aquatic organisms. Amphipods are one of the most abundant and functionally important groups of freshwater macroinvertebrates. Therefore, we conducted a laboratory experiment with Gammarus pulex, naturally infected with microsporidians. Methods In each group, 42 gammarids were exposed to 15°C and 25°C for 24 h. Sex of gammarids was determined and microsporidian infections were detected by specific PCR. To quantify stress levels of the amphipods, the 70 kDa heat shock proteins (hsp70) were analyzed by western blot. Results More males than females were detected in the randomized population sample (ratio of females/males: 0.87). No mortality occurred at 15°C, while 42.9% of gammarids died at 25°C. Sequences of three microsporidians (M1, M2, M3) were detected in this G. pulex population (99.7%-100% sequence identity to Microsporidium spp. from GenBank). Previous studies showed that M3 is vertically transmitted, while M1 and M2 are presumably horizontally transmitted. Prevalences, according to PCR, were 27.0%, 37.8% and 64.9% for Microsporidium sp. M1, M2 and M3, respectively. Cumulative prevalence was 82.4%. Multiple infections with all three microsporidians in single gammarids were detected with a prevalence of 8.1%, and bi-infections ranged between 12.2% and 25.7%. In dead gammarids, comparatively low prevalences were noted for M1 (males and females: 11.1%) and M2 (females: 11.1%; males 0%), while prevalence of M3 was higher (females: 66.7%; males: 88.9%). No significant effect of host sex on microsporidian infection was found. Significant effects of temperature and bi-infection with Microsporidium spp. M2 + M3 on hsp70 response were detected by analysis of the whole sample (15°C and 25°C group) and of M2 + M3 bi-infection and gammarid weight when analyzing the 25°C group separately. None of the parameters had a significant effect on hsp70 levels in the 15°C group. Conclusion This

  8. Vitellogenin-like gene expression in freshwater amphipod Gammarus fossarum (Koch, 1835): functional characterization in females and potential for use as an endocrine disruption biomarker in males.

    PubMed

    Xuereb, Benoît; Bezin, Laurent; Chaumot, Arnaud; Budzinski, Hélène; Augagneur, Sylvie; Tutundjian, Renaud; Garric, Jeanne; Geffard, Olivier

    2011-08-01

    The induction of vitellogenin (Vtg) synthesis is widely accepted as a biomarker of estrogenic exposure in male and juvenile fish. Vtg synthesis has emerged as an interesting endpoint to assess endocrine disruptor (ED) effects in crustaceans. However, studies reporting induction of Vtg in male crustaceans are lacking. This study investigated the expression of the Vtg gene in a freshwater amphipod, Gammarus fossarum, using calibrated real-time reverse transcription polymerase chain reaction (real-time RT PCR). First, we described the basal pattern of expression in healthy male and female organisms at different reproductive moult stages, in order to validate the function of this gene. Females expressed from 200 to 700 times more Vtg transcripts than males, depending on the female reproductive stage. Females displayed significant elevation of Vtg mRNA levels at the end of the inter-moult phase and at the beginning of the pre-moult phase. Second, male gammarids were exposed to the estrogenic compound nonylphenol (NP) (0.05, 0.5, 5 and 50 μg L(-1)) and to the anti-androgen cyproterone (1, 10, 100 and 1000 μg L(-1)) for 2, 4, 8 and 16 days. Both chemicals altered the pattern of interindividual variability of Vtg gene expression in males with strong induction in some individuals. Finally, the impact of urban wastewater treatment plants (WWTP) on male Vtg gene expression was assessed in organisms transplanted in the field during in situ bioassay campaigns in three different watersheds. Induction of the Vtg mRNA level was observed in males transplanted downstream from WWTP effluent discharge in two of the three study sites. PMID:21701845

  9. Effects of water temperature and pH on toxicity of terbufos, trichlorfon, 4-nitrophenol and 2,4- dinitrophenol to the amphipod Gammarus pseudolimnaeus and rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Howe, G.E.; Marking, L.L.; Bills, T.D.; Rach, J.J.; Mayer, F.L., Jr.

    1994-01-01

    Acute toxicity tests were conducted to determine (a) the individual and interactive effects of water temperature (7, 12, 17 degree C), pH (6.5, 7.5, 8.5, 9.5), and time on the toxicity of terbufos, trichlorfon, 4- nitrophenol, and 2,4-dinitrophenol to rainbow trout (Oncorhynchus mykiss) and the amphipod Gammarus pseudolimnaeus, and (b) the individual and interactive effects of water temperature and pH on chemical bioconcentration during acute tests with rainbow trout and Gammarus exposed to terbufos, 4-nitrophenol, and 2,4-dinitrophenol. The toxicity of all four chemicals was significantly affected by pH in all tests, except for Gammarus exposed to terbufos. The toxicity of terbufos to rainbow trout and Gammarus was less at pH 7.5 than at higher or lower pH. The toxicity of both nitrophenols decreased as pH increased, whereas the toxicity of trichlorfon increased with pH. The effect of pH on trichlorfon toxicity decreased with temperature. Temperature significantly affected the toxicity of all four chemicals to both species. Toxicity increased with temperature in all tests, except for rainbow trout exposed to nitrophenols; toxicity decreased as temperature increased for rainbow trout. Chemical bioconcentration was also significantly affected by temperature and pH and was directly related to toxicity in most tests. Significant interactive effects between toxicity-modifying factors were also frequently observed. Temperature and pH effects on chemical toxicity need to be considered in chemical hazard assessment to ensure adequate protection of aquatic organisms.

  10. Effects of water temperature and pH on toxicity of terbufos, trichlorfon, 4-nitrophenol and 2,4-dinitrophenol to the amphipod Gammarus pseudolimnaeus and rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Howe, G.E.; Marking, L.L.; Bills, T.D.; Rach, J.J. . National Fisheries Research Center); Mayer, F.L. Jr. . Environmental Research Lab.)

    1994-01-01

    Acute toxicity tests were conducted to determine (a) the individual and interactive effects of water temperature (7, 12, 17 C), pH (6.5, 7.5, 8.5, 9.5), and time on the toxicity of terbufos, trichlorfon, 4-nitrophenol, and 2,4-dinitrophenol to rainbow trout (Oncorhynchus mykiss) and the amphipod Gammarus pseudolimnaeus, and (b) the individual and interactive effects of water temperature and pH on chemical bioconcentration during acute tests with rainbow trout and Gammarus exposed to terbufos, 4-nitrophenol, and 2,4-dinitrophenol. The toxicity of all four chemicals was significantly affected by pH in all tests, except for Gammarus exposed to terbufos. The toxicity of terbufos to rainbow trout and Gammarus was less at pH 7.5 than at higher or lower pH. The toxicity of both nitrophenols decreased as pH increased, whereas the toxicity of trichlorfon increased with pH. The effect of pH on trichlorfon toxicity decreased with temperature. Temperature significantly affected the toxicity of all four chemicals to both species. Toxicity increased with temperature in all tests, except for rainbow trout exposed to nitrophenols; toxicity decreased as temperature increased for rainbow trout. Chemical bioconcentration was also significantly affected by temperature and pH and was directly related to toxicity in most tests. Significant interactive effects between toxicity-modifying factors were also frequently observed. Temperature and pH effects on chemical toxicity need to be considered in chemical hazard assessment to ensure adequate protection of aquatic organisms.

  11. Redescription of Gammarus pseudosyriacus (Karaman & Pinkster, 1977) and description of a new subspecies from southern Iran (Crustacea, Amphipoda, Gammaridae)

    PubMed Central

    Semsar-Kazerooni, Maryam; Zamanpoore, Mehrdad; Sadeghi, Saber

    2016-01-01

    Abstract The present study focused on redescription of Gammarus pseudosyriacus (Karaman & Pinkster, 1977) based on new materials from Zagros Mountains and describes a new subspecies of freshwater amphipod, Gammarus pseudosyriacus issatisi subsp. n., from the southern Zagros Mountains. The work is based on morphological and morphometric comparisons. This new subspecies has features similar to Gammarus pseudosyriacus. The distinct features that distinguish Gammarus pseudosyriacus issatisi subsp. n. from Gammarus pseudosyriacus are the smaller eyes, shorter body length, and shorter flagellum of antenna 1 and 2. PMID:27408590

  12. Redescription of Gammarus pseudosyriacus (Karaman & Pinkster, 1977) and description of a new subspecies from southern Iran (Crustacea, Amphipoda, Gammaridae).

    PubMed

    Semsar-Kazerooni, Maryam; Zamanpoore, Mehrdad; Sadeghi, Saber

    2016-01-01

    The present study focused on redescription of Gammarus pseudosyriacus (Karaman & Pinkster, 1977) based on new materials from Zagros Mountains and describes a new subspecies of freshwater amphipod, Gammarus pseudosyriacus issatisi subsp. n., from the southern Zagros Mountains. The work is based on morphological and morphometric comparisons. This new subspecies has features similar to Gammarus pseudosyriacus. The distinct features that distinguish Gammarus pseudosyriacus issatisi subsp. n. from Gammarus pseudosyriacus are the smaller eyes, shorter body length, and shorter flagellum of antenna 1 and 2. PMID:27408590

  13. Parasite altered micro-distribution of Gammarus pulex (Crustacea: Amphipoda).

    PubMed

    MacNeil, Calum; Fielding, Nina J; Hume, Kevin D; Dick, Jaimie T A; Elwood, Robert W; Hatcher, Melanie J; Dunn, Alison M

    2003-01-01

    In a river survey, Gammarus pulex amphipods both unparasitised and parasitised with the acanthocephalan Echinorhynchus truttae were distributed similarly with respect to flow regimen, tending to be more abundant in faster, shallower, riffle patches. However, there was a higher prevalence of parasitism in faster, shallower areas than in slower, deeper areas and abundance correlated with macrophyte coverage for unparasitised but not parasitised amphipods, indicating subtle differences in habitat usage. A laboratory 'patch' simulation indicated that parasitism influenced micro-distribution. There were higher proportions of unparasitised amphipods in/under stone substrates and within weed. In contrast, there were higher proportions of parasitised amphipods in the water column and at the water surface. As the experiment progressed, unparasitised but not parasitised amphipod habitat usage shifted from those micro-habitats above the substrate and in the water column to those in/under the substrates. Experiments also demonstrated that parasitised amphipods were more active and had a greater preference for illumination. Previous studies of the effects of acanthocephalan parasitism of amphipod hosts have focussed on how drift behaviour is altered, now we show that subtle differences in micro-habitat usage could translate to greatly increased vulnerability to fish predation. We discuss how aggregation of parasitised individuals within specific habitats could promote parasite transmission. PMID:12547346

  14. PHOTOACTIVATED TOXICITY IN AMPHIPODS COLLECTED FROM POLYCYCLIC AROMATIC HYDROCARBON-CONTAMINATED SITES

    EPA Science Inventory

    The risk of photo-activated PAH toxicity in contaminated aquatic systems has not been well characterized. To better indicate this potential, amphipods (Gammarus spp.) were collected from two PAH contaminated sites (Hog Island and USX), as well as a reference site (Chipmunk Cove)...

  15. Amphipod densities and indices of wetland quality across the upper-Midwest, USA

    USGS Publications Warehouse

    Anteau, M.J.; Afton, A.D.

    2008-01-01

    Nutritional, behavioral, and diet data for lesser scaup (Aythya affinis [Eyton, 1838]) indicates that there has been a decrease in amphipod (Gammarus lacustris [G. O. Sars, 1863] and Hyalella azteca [Saussure, 1858]) density and wetland quality throughout the upper-Midwest, USA. Accordingly, we estimated densities of Gammarus and Hyalella in six eco-physiographic regions of Iowa, Minnesota, and North Dakota; 356 randomly selected semipermanent and permanent wetlands were sampled during springs 2004 and 2005. We also examined indices of wetland quality (e.g., turbidity, fish communities, aquatic vegetation) among regions in a random subset of these wetlands (n = 267). Gammarus and Hyalella were present in 19% and 54% of wetlands sampled, respectively. Gammarus and Hyalella densities in North Dakota were higher than those in Iowa and Minnesota. Although historical data are limited, our regional mean (1 to 12 m-3) amphipod densities (Gammarus + Hyalella) were markedly lower than any of the historical density estimates. Fish, important predators of amphipods, occurred in 31%-45% of wetlands in North Dakota, 84% of wetlands in the Red River Valley, and 74%-84% of wetlands in Iowa and Minnesota. Turbidity in wetlands of Minnesota Morainal (4.0 NTU geometric mean) and Red River Valley (6.1 NTU) regions appeared low relative to that of the rest of the upper-Midwest (13.2-17.5 NTU). We conclude that observed estimates of amphipods, fish, and turbidity are consistent with low wetland quality, which has resulted in lower food availability for various wildlife species, especially lesser scaup, which use these wetlands in the upper-Midwest. ?? 2008, The Society of Wetland Scientists.

  16. Proteogenomic insights into the core-proteome of female reproductive tissues from crustacean amphipods.

    PubMed

    Trapp, Judith; Almunia, Christine; Gaillard, Jean-Charles; Pible, Olivier; Chaumot, Arnaud; Geffard, Olivier; Armengaud, Jean

    2016-03-01

    As a result of the poor genome sequence coverage of crustacean amphipods, characterization of their evolutionary biology relies mostly on phenotypic traits. Here, we analyzed the proteome of ovaries from five amphipods, all from the Senticaudata suborder, with the objective to obtain insights into the core-proteome of female reproductive systems. These amphipods were from either the Gammarida infraorder: Gammarus fossarum, Gammarus pulex, Gammarus roeseli, or the Talitrida infraorder: Parhyale hawaiensis and Hyalella azteca. Ovaries from animals sampled at the end of their reproductive cycle were dissected. Their whole protein contents were extracted and their proteomes were recorded by high-throughput nanoLC-MS/MS with a high-resolution mass spectrometer. We interpreted tandem mass spectrometry data with the protein sequence resource from G. fossarum and P. hawaiensis, both recently established by RNA sequencing. The large molecular biodiversity within amphipods was assessed by the ratio of MS/MS spectra assigned for each sample, which tends to diverge rapidly along the taxonomic level considered. The core-proteome was defined as the proteins conserved along all samples, thus detectable by the homology-based proteomic assignment procedure. This specific subproteome may be further enriched in the future with the analysis of new species and update of the protein sequence resource. PMID:26170043

  17. Invasive Macroinvertebrates in the Upper Mississippi River system: Recent Findings

    EPA Science Inventory

    Zoobenthos surveys of the great rivers of the Upper Mississippi River basin (Missouri, Upper Mississippi, and Ohio Rivers) in 2004-2006 revealed new invasions by marine and estuarine amphipods. The gammarid amphipods Echinogammarus ischnus and Gammarus tigrinus were discovered i...

  18. A transmission electron microscope investigation of the effect of lead acetate on the hepatopancreatic ceca of Gammarus pulex.

    PubMed

    Kutlu, Mehtap; Düzen, Ayla; Bayçu, Cengiz; Ozata, Ahmet

    2002-10-01

    The freshwater Amphipod Gammarus pulex is a sensitive indicator organism for environmental contamination. In this study, effects of heavy metal lead acetate were investigated by using electron microscopy techniques. Control group was not expose to lead acetate but experimental group was for 96 h. The ultrastructural changes of hepatopancreatic ceca cells were studied in these two groups by electron microscopy techniques analysing cellular structure, structure of organelles and vacuolization. The number of cells based on the toxic effects of lead acetate was increased compared with the control group. The number and length of cell microvilli was decreased. Additionally degenerated mitocondria, dilation of golgi vesicules and cytoplasmic vacuolization were observed. The results of present study suggest that the exposure to the lead acetate may cause some ultrastructural changes on hepatopancreatic ceca of digestive system in Gammarus pulex. The significance of this change in terms of environmental toxicology needs to be further studied. PMID:21782637

  19. Field deployment of a scope for growth assay involving Gammarus pulex, a freshwater benthic invertebrate

    SciTech Connect

    Maltby, L.; Naylor, C.; Calow, P. )

    1990-06-01

    Scope for growth (SfG) is a measure of the energy balance of an animal (i.e., the difference between energy intake and metabolic output). The SfG of marine invertebrates, particularly the mussel Mytilus edulis, has been successfully used as the basis of a field bioassay to detect a range of stresses both natural (temperature, food, salinity) and anthropogenic (hydrocarbons, sewage sludge). SfG of the freshwater amphipod Gammarus pulex was found to be a sensitive indicator of stress under laboratory conditions and here we describe the field deployment of this technique and present data from three field trials. In every case, SfG was reduced at the downstream polluted site compared with that at an upstream reference site. This reduction in SfG was the result of a decrease in energy intake (absorption) rather than an increase in energy expenditure (respiration).

  20. Does foreplay matter? Gammarus pulex females may benefit from long-lasting precopulatory mate guarding

    PubMed Central

    Galipaud, Matthias; Dechaume-Moncharmont, François-Xavier; Oughadou, Abderrahim; Bollache, Loïc

    2011-01-01

    Precopulatory mate guarding (PCMG) is generally assumed to be costly for both sexes. However, males may gain by displaying long-lasting mate guarding under strong male–male competition. Surprisingly, the potential for females to benefit from being held by males has been largely overlooked in previous studies. In Gammarus pulex, an amphipod crustacean, PCMG lasts several weeks, yet females are described as bearing only cost from such male mating strategy. We investigated potential female benefits by assessing the effect of mate guarding on her intermoult duration. Unpaired females had longer intermoult duration than paired females. Intermoult duration clearly decreased when paired females engaged in early and long-lasting mate guarding. In addition, short intermoults and long-lasting mate guarding had no effect on egg number. These results highlight a potential benefit associated with PCMG for G. pulex females, suggesting that the strength of an intersexual conflict over its duration may be overestimated. PMID:21068026

  1. The functional and physiological status of Gammarus fossarum (Crustacea; Amphipoda) exposed to secondary treated wastewater.

    PubMed

    Bundschuh, Mirco; Zubrod, Jochen P; Schulz, Ralf

    2011-01-01

    Climate change scenarios predict lower flow rates during summer that may lead to higher proportions of wastewater in small and medium sized streams. Moreover, micropollutants (e.g. pharmaceuticals and other contaminants) continuously enter aquatic environments via treated wastewater. However, there is a paucity of knowledge, whether extended exposure to secondary treated wastewater disrupts important ecosystem functions, e.g. leaf breakdown. Therefore, the amphipod shredder Gammarus fossarum was exposed to natural stream water (n=34) and secondary treated wastewater (n=32) for four weeks in a semi-static test system under laboratory conditions. G. fossarum exposed to wastewater showed significant reductions in feeding rate (25%), absolute consumption (35%), food assimilation (50%), dry weight (18%) and lipid content (22%). Thus, high proportions of wastewater in the stream flow may affect both the breakdown rates of leaf material and thus the availability of energy for the aquatic food web as well as the energy budget of G. fossarum. PMID:20932616

  2. Influence of gender and season on reduced glutathione concentration and energy reserves of Gammarus roeseli.

    PubMed

    Gismondi, Eric; Beisel, Jean-Nicolas; Cossu-Leguille, Carole

    2012-10-01

    As biomarkers are known to be influenced by biotic and abiotic factors (e.g. gender, temperature), we investigated over a one-year long sampling period, the influence of season and gender on reduced glutathione concentrations and its synthesis in the crustacean amphipod Gammarus roeseli. At the same time, we assessed energy reserves and malondialdehyde levels as toxic biomarker. Results have shown that, in both genders, reduced glutathione concentrations were inversely correlated to water temperature, and higher in females than in males whatever the season. Total lipid and glycogen contents were higher in females than in males, allowing females to have enough energy to assume the reproductive period and maintain high GSH concentrations for detoxification processes. Conversely, females have lower cell damages than males. These differences between genders could induce differential sensitivity in a contamination context, and thus affect the population. Females could resist better than males in contaminated environments, especially in spring when reduced glutathione concentration is the highest. PMID:22769238

  3. Identification of a putatively multixenobiotic resistance related Abcb1 transporter in amphipod species endemic to the highly pristine Lake Baikal.

    PubMed

    Pavlichenko, Vasiliy V; Protopopova, Marina V; Timofeyev, Maxim; Luckenbach, Till

    2015-04-01

    The fauna of Lake Baikal in Eastern Siberia, the largest freshwater body on Earth, is characterized by high degrees of biodiversity and endemism. Amphipods, a prominent taxon within the indigenous fauna, occur in an exceptionally high number of endemic species. Considering the specific water chemistry of Lake Baikal with extremely low levels of potentially toxic natural organic compounds, it seems conceivable that certain adaptions to adverse environmental factors are missing in endemic species, such as cellular defense mechanisms mitigating toxic effects of chemicals. The degree to which the endemic fauna is affected by the recently occurring anthropogenic water pollution of Lake Baikal may depend on the existence of such cellular defense mechanisms in those species. We here show that endemic amphipods express transcripts for Abcb1, a major component of the cellular multixenobiotic resistance (MXR) defense against toxic chemicals. Based on a partial abcb1 cDNA sequence from Gammarus lacustris, an amphipod species common across Northern Eurasia but only rarely found in Lake Baikal, respective homologous sequences were cloned from five amphipods endemic to Lake Baikal, Eulimnogammarus verrucosus, E. vittatus, E. cyaneus, E. marituji, and Gmelinoides fasciatus, confirming that abcb1 is transcribed in those species. The effects of thermal (25 °C) and chemical stress (1-2 mg L(-1) phenanthrene) in short-term exposures (up to 24 h) on transcript levels of abcb1 and heat shock protein 70 (hsp70), used as a proxy for cellular stress in the experiments, were exemplarily examined in E. verrucosus, E. cyaneus, and Gammarus lacustris. Whereas increases of abcb1 transcripts upon treatments occurred only in the Baikalian species E. verrucosus and E. cyaneus but not in Gammarus lacustris, changes of hsp70 transcript levels were seen in all three species. At least for species endemic to Lake Baikal, the data thus indicate that regulation of the identified amphipod abcb1 is

  4. Ovarian response to repeated administration of alternating exogenous gonadotropin regimens in the ocelot (Leopardus pardalis) and tigrinus (Leopardus tigrinus).

    PubMed

    da Paz, Regina Celia Rodrigues; Dias, Eduardo Antunes; Adania, Cristina Harumi; Barnabe, Valquíria Hippólito; Barnabe, Renato Campanarut

    2006-10-01

    Exogenous gonadotropins are used to stimulate ovarian follicular growth and ovulation in mammalian species, including wild cats. However, successes in application of assisted reproduction techniques in nondomestic felids have been sparse. Our objectives were to assess the effectiveness of alternating gonadotropin regimens on ovarian responses. Five adult female ocelots and four adult female tigrinus were treated four to six times, using alternating eCG/hCG and pFSH/pLH at 4-month intervals. Laparoscopies were done to assess follicular development and to collect oocytes from matures follicles. The average number of follicles and corpus luteum (CL) per stimulation was higher in ocelots (7.0 +/- 0.8; mean +/- S.E.M.) than in tigrinus (2.5 +/- 0.4; P < 0.05), but the percentage of mature oocytes did not differ between the two species (mean range, 54-55%). Within species, both gonadotropin regimens were equally effective in inducing follicular growth and oocyte maturation. The total number of ovarian structures and oocyte maturation percentages did not decrease in either species with sequential stimulations. In summary, female ocelots and tigrinus continued to respond to repeated alternating ovarian stimulation protocols. In conclusion, the use of alternating gonadotropin regimens may permit more intensive reproductive management in these endangered cats. PMID:16472853

  5. Separate and combined effects of habitat-specific fish predation on the survival of invasive and native gammarids

    NASA Astrophysics Data System (ADS)

    Kotta, Jonne; Orav-Kotta, Helen; Herkül, Kristjan

    2010-10-01

    The North-American amphipod Gammarus tigrinus was observed for the first time in the northern Baltic Sea in 2003. The invasive amphipod has been particularly successful in some habitats (e.g. on pebbles) where it has become one of the most abundant gammarid species. We studied experimentally if the dominant fish Gasterosteus aculeatus preyed differentially on the exotic G. tigrinus and the native Gammarus salinus, if predation differed among habitats, and if one gammarid species facilitated predation on the other. The experiment demonstrated that (1) fish preyed more on the exotic G. tigrinus than the native G. salinus. (2) Predation did not differ among habitats. (3) Gammarus tigrinus facilitated the predation on G. salinus and this facilitation varied among habitats with significant effects on pebbles. Thus, the combined effect of habitat-specific fish predation and competition between gammarid amphipods is a possible explanation of the current range of G. tigrinus in the northern Baltic Sea. G. tigrinus seems to establish in habitats where it can significantly increase fish predation on the native gammarids.

  6. Mechanisms of parasite-induced sex reversal in Gammarus duebeni.

    PubMed

    Rodgers-Gray, Trevor P; Smith, Judith E; Ashcroft, Alison E; Isaac, R Elwyn; Dunn, Alison M

    2004-05-01

    The amphipod Gammarus duebeni is host to the feminising microsporidian parasite Nosema granulosis that converts males into functional females. To test the hypothesis that the parasite acts through endocrine disruption we compared the morphology of the gonad and activity of the androgenic gland, which coordinates male sexual differentiation, in infected and uninfected animals. Male gonad consisted of testis, seminal vesicle and vas deferens that was anchored to the genital papilla on segment 7. The androgenic gland was associated with the distal end of the vas deferens. In female and intersex animals the bi-lobed ovary opened into the oviduct at segment 5, vestigial vas deferens and vestigial androgenic gland were retained. The majority of parasitised individuals (38/39) were either phenotypic females or intersexes with fully developed ovaries and an undifferentiated androgenic gland. Our data suggest that the parasite prevents differentiation of the androgenic gland. In further support of this hypothesis, mass spectrometry of a single androgenic gland from males revealed a dominant molecular ion with a mass/charge ratio of 4818.4+H, corresponding to a peptide of androgenic gland hormone from Armadillidium vulgare. In contrast the vestigial androgenic gland from parasitised and unparasitised females showed only low intensity peaks. Our observations demonstrate that the parasite manipulates host sex by preventing androgenic gland differentiation, androgenic gland hormone production and consequently male differentiation. This is in agreement with observations of A. vulgare with inherited Wolbachia infection, suggesting that phylogenetically distant feminisers manipulate hosts through a common mechanism. The high frequency of infection in intersexes (89.3%) suggests that this phenotype results from incomplete feminisation by the parasite. PMID:15111096

  7. Field evidence for non-host predator avoidance in a manipulated amphipod

    NASA Astrophysics Data System (ADS)

    Médoc, Vincent; Beisel, Jean-Nicolas

    2009-04-01

    Manipulative parasites are known to alter the spatial distribution of their intermediate hosts in a way that enables trophic transmission to definitive hosts. However, field data on the ecological implications of such changes are lacking. In particular, little is known about the spatial coexistence between infected prey and dead-end predators after a parasite-induced habitat shift. Here, we used an Amphipoda ( Gammarus roeseli)-Acanthocephala ( Polymorphus minutus) association to investigate how infection with a manipulative parasite affects the predation risk by non-hosts within the invertebrate community. First, we collected invertebrates by sampling various natural habitats and calculated the distribution amplitude of amphipods according to their infection status. Infection with P. minutus significantly reduced the habitat breadth in G. roeseli, parasitised individuals being mainly found in floating materials whereas uninfected ones were widespread throughout the sampled habitats. Second, to test if these changes also affect the risk for P. minutus to be ingested by non-hosts, we estimated the predation risk experienced by G. roeseli within the macro-invertebrate community. The habitat overlap between potential invertebrate predators and G. roeseli showed that the spatial probability of encounter was lower for P. minutus-infected amphipods than for uninfected conspecifics. For the first time, to our knowledge, a study used ecological tools to bring field evidence for the spatial avoidance of dead-end predators in a manipulated amphipod.

  8. Polycyclic aromatic compound profiles from extracts of Dreissenid mussels and gammarid amphipods coexisting in Hamilton Harbor

    SciTech Connect

    Marvin, C.H.; McCarry, B.E.; Allan, L.; Bryant, D.W.

    1995-06-01

    Aggregates of dreissenid mussels were collected in Hamilton Harbour (western Lake Ontario) from a south shore site (Randle Reef) in an area characterized by coal tar-contaminated sediments, and from a site on the north shore exposed to particulates circulating in the harbour water column. Samples were separated into three components: dreissend mussels, gammarid amphipods (Gammarus fasciatus), and particulate material. The samples were freeze-dried, and extracted using ultrasonication in dichloromethane. The organic solvent extracts were subjected to an open-column alumina and Sephadex LH-20 gel column clean-up procedure, and characterized by gas chromatography-mass spectrometry (GC-MS). The chromatographic profiles of all sample extracts were dominated by polycyclic aromatic hydrocarbons (PAH). The concentrations of the individual compounds were normalized for contaminant profile comparison of the extracts of dreissenids, amphipods, and particulates associated with aggregates of dreissenid mussels. These profiles were also compared with extracts of coal tar-contaminated sediment from the Randle Reef area, and extracts of suspended particulates obtained from sediment traps. The similarities in the PAH profiles provide evidence of exposure to a common source of contaminants. These data also show that PAH associated with suspended particulates obtained from sediment traps. The similarities in the PAH profiles provide evidence of exposure to a common source of contaminants. These data also show that PAH associated with suspended particulates in Hamilton Harbour are being accumulated by dreissenid mussels and gammarid amphipods.

  9. Drastic underestimation of amphipod biodiversity in the endangered Irano-Anatolian and Caucasus biodiversity hotspots.

    PubMed

    Katouzian, Ahmad-Reza; Sari, Alireza; Macher, Jan N; Weiss, Martina; Saboori, Alireza; Leese, Florian; Weigand, Alexander M

    2016-01-01

    Biodiversity hotspots are centers of biological diversity and particularly threatened by anthropogenic activities. Their true magnitude of species diversity and endemism, however, is still largely unknown as species diversity is traditionally assessed using morphological descriptions only, thereby ignoring cryptic species. This directly limits evidence-based monitoring and management strategies. Here we used molecular species delimitation methods to quantify cryptic diversity of the montane amphipods in the Irano-Anatolian and Caucasus biodiversity hotspots. Amphipods are ecosystem engineers in rivers and lakes. Species diversity was assessed by analysing two genetic markers (mitochondrial COI and nuclear 28S rDNA), compared with morphological assignments. Our results unambiguously demonstrate that species diversity and endemism is dramatically underestimated, with 42 genetically identified freshwater species in only five reported morphospecies. Over 90% of the newly recovered species cluster inside Gammarus komareki and G. lacustris; 69% of the recovered species comprise narrow range endemics. Amphipod biodiversity is drastically underestimated for the studied regions. Thus, the risk of biodiversity loss is significantly greater than currently inferred as most endangered species remain unrecognized and/or are only found locally. Integrative application of genetic assessments in monitoring programs will help to understand the true magnitude of biodiversity and accurately evaluate its threat status. PMID:26928527

  10. Drastic underestimation of amphipod biodiversity in the endangered Irano-Anatolian and Caucasus biodiversity hotspots

    PubMed Central

    Katouzian, Ahmad-Reza; Sari, Alireza; Macher, Jan N.; Weiss, Martina; Saboori, Alireza; Leese, Florian; Weigand, Alexander M.

    2016-01-01

    Biodiversity hotspots are centers of biological diversity and particularly threatened by anthropogenic activities. Their true magnitude of species diversity and endemism, however, is still largely unknown as species diversity is traditionally assessed using morphological descriptions only, thereby ignoring cryptic species. This directly limits evidence-based monitoring and management strategies. Here we used molecular species delimitation methods to quantify cryptic diversity of the montane amphipods in the Irano-Anatolian and Caucasus biodiversity hotspots. Amphipods are ecosystem engineers in rivers and lakes. Species diversity was assessed by analysing two genetic markers (mitochondrial COI and nuclear 28S rDNA), compared with morphological assignments. Our results unambiguously demonstrate that species diversity and endemism is dramatically underestimated, with 42 genetically identified freshwater species in only five reported morphospecies. Over 90% of the newly recovered species cluster inside Gammarus komareki and G. lacustris; 69% of the recovered species comprise narrow range endemics. Amphipod biodiversity is drastically underestimated for the studied regions. Thus, the risk of biodiversity loss is significantly greater than currently inferred as most endangered species remain unrecognized and/or are only found locally. Integrative application of genetic assessments in monitoring programs will help to understand the true magnitude of biodiversity and accurately evaluate its threat status. PMID:26928527

  11. Field evidence for non-host predator avoidance in a manipulated amphipod.

    PubMed

    Médoc, Vincent; Beisel, Jean-Nicolas

    2009-04-01

    Manipulative parasites are known to alter the spatial distribution of their intermediate hosts in a way that enables trophic transmission to definitive hosts. However, field data on the ecological implications of such changes are lacking. In particular, little is known about the spatial coexistence between infected prey and dead-end predators after a parasite-induced habitat shift. Here, we used an Amphipoda (Gammarus roeseli)-Acanthocephala (Polymorphus minutus) association to investigate how infection with a manipulative parasite affects the predation risk by non-hosts within the invertebrate community. First, we collected invertebrates by sampling various natural habitats and calculated the distribution amplitude of amphipods according to their infection status. Infection with P. minutus significantly reduced the habitat breadth in G. roeseli, parasitised individuals being mainly found in floating materials whereas uninfected ones were widespread throughout the sampled habitats. Second, to test if these changes also affect the risk for P. minutus to be ingested by non-hosts, we estimated the predation risk experienced by G. roeseli within the macro-invertebrate community. The habitat overlap between potential invertebrate predators and G. roeseli showed that the spatial probability of encounter was lower for P. minutus-infected amphipods than for uninfected conspecifics. For the first time, to our knowledge, a study used ecological tools to bring field evidence for the spatial avoidance of dead-end predators in a manipulated amphipod. PMID:19139837

  12. Evaluation of biochemical responses in Palearctic and Lake Baikal endemic amphipod species exposed to CdCl2.

    PubMed

    Timofeyev, M A; Shatilina, Z M; Bedulina, D S; Protopopova, M V; Pavlichenko, V V; Grabelnych, O I; Kolesnichenko, A V

    2008-05-01

    This study evaluated small heat shock proteins (sHSP) (related to alpha-crystallin) and antioxidant enzymes (POD, peroxidase and CAT, catalase) as possible biomarkers for use in toxicological studies. Biochemical responses to cadmium chloride in two Lake Baikal endemic amphipods (Eulimnogammarus verrucosus, Eulimnogammarus cyaneus) and Palearctic species (Gammarus lacustris) were compared. Our findings showed that cadmium chloride toxicity directly influenced POD activity and sHSP synthesis in all amphipod species. The Baikalean endemic and the Palearctic amphipod species responded by decreasing activity of POD and they exhibited a dose-dependent activation of sHSP synthesis. All measured parameters differed among species and depended on the species' ability to resist cadmium chloride toxicity. CAT activity in the Palearctic species responded significantly to cadmium chloride exposure; however, responses were negligible for both Baikalean species. We suggest that synthesis of sHSP, together with changes in POD activity, could be used as biomarkers for further studies of amphipod species including endemics from Lake Baikal. PMID:17920682

  13. An acanthocephalan parasite increases the salinity tolerance of the freshwater amphipod Gammarus roeseli (Crustacea: Gammaridae)

    NASA Astrophysics Data System (ADS)

    Liu, K. S.; Chan, J. C. L.; Cheng, W. C.; Tai, S. L.; Wong, P. W.

    2007-08-01

    This study examines the convection distribution associated with 18 TCs that made landfall along the South China coast during 1995 and 2005. Cloud-top temperatures from high-resolution satellite imageries of the Geosynchronous Meteorological Satellite 5 are used as proxy of strong convection. It is found that convection tends to be enhanced on the western side of the TC as it makes landfall in 10 of the cases, in agreement with the conclusion of some previous studies. Four cases have stronger convection on the eastern side. This “deviation” from the general rule appears to be related to the TCs being more slow-moving or their interaction of the TC with another land surface prior to its making landfall along the South China coast. For the remaining cases in which no significant asymmetries in convection can be identified, the vertical wind shear appears to enhance convection on the east side.

  14. Contrasting cellular stress responses of Baikalian and Palearctic amphipods upon exposure to humic substances: environmental implications.

    PubMed

    Protopopova, Marina V; Pavlichenko, Vasiliy V; Menzel, Ralph; Putschew, Anke; Luckenbach, Till; Steinberg, Christian E W

    2014-12-01

    The species-rich, endemic amphipod fauna of Lake Baikal does not overlap with the common Palearctic fauna; however, the underlying mechanisms for this are poorly understood. Considering that Palearctic lakes have a higher relative input of natural organic compounds with a dominance of humic substances (HSs) than Lake Baikal, we addressed the question whether HSs are candidate factors that affect the different species compositions in these water bodies. We hypothesized that interspecies differences in stress defense might reveal that Baikalian amphipods are inferior to Palearctic amphipods in dealing with HS-mediated stress. In this study, two key mechanisms of general stress response were examined: heat-shock protein 70 (HSP70) and multixenobiotic resistance-associated transporters (ABCB1). The results of quantitative polymerase chain reaction (qPCR) showed that the basal levels (in 3-day acclimated animals) of hsp70 and abcb1 transcripts were lower in Baikalian species (Eulimnogammarus cyaneus, Eulimnogammarus verrucosus, Eulimnogammarus vittatus-the most typical littoral species) than in the Palearctic amphipod (Gammarus lacustris-the only Palearctic species distributed in the Baikalian region). In the amphipods, the stress response was induced using HSs at 10 mg L(-1) dissolved organic carbon, which was higher than in sampling sites of the studied species, but well within the range (3-10 mg L(-1)) in the surrounding water bodies populated by G. lacustris. The results of qPCR and western blotting (n = 5) showed that HS exposure led to increased hsp70/abcb1 transcripts and HSP70 protein levels in G. lacustris, whereas these transcript levels remained constant or decreased in the Baikalian species. The decreased level of stress transcripts is probably not able to confer an effective tolerance to Baikalian species against further environmental stressors in conditions with elevated HS levels. Thus, our results suggest a greater robustness of Palearctic amphipods and

  15. Ecosystem connectivity: anadromous fish migration linked to freshwater amphipods

    NASA Astrophysics Data System (ADS)

    Macavoy, S. E.; Fogel, M. L.; Fong, D.; Hanson, N.

    2009-12-01

    Anadromous fish migrate to coastal streams to spawn each spring and may transfer marine derived nutrients to oligotrophic tidal freshwater. River herring (Alosa sp) are the dominant anadromous genus in Virginia, USA. This study investigates whether marine nutrients derived by the spawning Alosa were incorporated into benthic invertebrates by using the stable isotopes of carbon and nitrogen. Spawning Alosa had higher δ13C and δ15N than resident freshwater omnivorous fishes (-18.5 and 13.9‰ versus -25.7 and 11.8‰). In a tidal stream supporting abundant spawning Alosa, significant 13C and 15N enrichment was observed among stream invertebrates, particularly in the amphipod Gammarus fasciatus, coincident with the Alosa spawning migration. Among G. fasciatus, δ13C increased from -28.5 to -26.0‰ between early and late April then fell to -28.1‰ in early June. A similar trend was observed in mayflies (Heptageniidae). In an adjacent tidal stream that did not support spawning Alosa, enrichment among invertebrates was not observed. Particulate organic matter and sediments from both streams remained 13C and 15N depleted during the Alosa spawning run (between -29 and -28‰, 0.5 and 3.0‰ respectively), suggesting that marine material was not present. Although marine organic material may have been incorporated into stream invertebrates, it did not become a substantial component of other ecosystem components measured.

  16. Fish and land use influence Gammarus lacustris and Hyalella azteca (Amphipoda) densities in large wetlands across the upper Midwest

    USGS Publications Warehouse

    Anteau, Michael J.; Afton, Alan D.; Anteau, Andrea C.E.; Moser, E. Barry

    2011-01-01

    Gammarus lacustrisK/i> and Ki>Hyalella azteca (hereafter G. lacustris and H. azteca, respectively) are important components of secondary production in wetlands and shallow lakes of the upper Midwest, USA. Within the past 50 years, amphipod densities have decreased while occurrences of fish and intensity of agricultural land use have increased markedly across this landscape. We investigated influences of fish, sedimentation, and submerged aquatic vegetation (SAV) on densities of G. lacustris and H. azteca in semipermanent and permanent wetlands and shallow lakes (n = 283) throughout seven eco-physiographic regions of Iowa, Minnesota, and North Dakota during 2004–2005. G. lacustris and H. azteca densities were positively correlated with densities of SAV (P P P = 0.01 and P = 0.013, respectively) and with high densities of fathead minnows (Pimephales promelas; P P = 0.033, respectively). H. azteca densities also were negatively correlated with densities of small fish (e.g., other minnows [Cyprinidae] and sticklebacks [Gasterosteidae]; P = 0.048) and common carp (Cyprinus spp.; P = 0.022). G. lacustris densities were negatively correlated with high levels of suspended solids (an index for sedimentation; P H. azteca densities were positively correlated with the width of upland-vegetation buffers (P = 0.004). Our results indicate that sedimentation and fish reduce amphipod densities and may contribute to the current low densities of amphipods in the upper Midwest. Thus, removing/excluding fish, and providing a thick buffer of upland vegetation around wetlands may help restore amphipod densities and wetland and water quality within this landscape.

  17. Effect of gender on physiological and behavioural responses of Gammarus roeseli (Crustacea Amphipoda) to salinity and temperature.

    PubMed

    Sornom, Pascal; Felten, Vincent; Médoc, Vincent; Sroda, Sophie; Rousselle, Philippe; Beisel, Jean-Nicolas

    2010-05-01

    The importance of potentially interacting factors in organisms responses to a stress are often ignored or underestimated in ecotoxicology. In laboratory experiments we investigated how gender, temperature and age influence the behaviour and the physiology of the freshwater amphipod Gammarus roeseli under salinity stress. Our results revealed a significant higher sensitivity of females in survival, ventilation and ionoregulation whereas no inter-age differences were reported. Water temperature also exerted a significant effect in survival and ventilation of G. roeseli. Some of those factors appeared to interact significantly. This study provides evidence that gender can affect organisms responses to a stressor and consequently has to be considered while assessing a stress impact. We discussed the potential relationships between biological and behavioural responses. PMID:20176423

  18. Parasite-induced changes in the diet of a freshwater amphipod: field and laboratory evidence.

    PubMed

    Médoc, V; Piscart, C; Maazouzi, C; Simon, L; Beisel, J-N

    2011-04-01

    Trophically transmitted parasites are likely to strongly influence food web-structure. The extent to which they change the trophic ecology of their host remains nevertheless poorly investigated and field evidence is lacking. This is particularly true for acanthocephalan parasites whose invertebrate hosts can prey on other invertebrates and contribute to leaf-litter breakdown. We used a multiple approach combining feeding experiments, neutral lipids and stable isotopes to investigate the trophic ecology of the freshwater amphipod Gammarus roeseli parasitized by the bird acanthocephalan Polymorphus minutus. Infected compared to uninfected amphipods consumed as many dead isopods, but fewer live isopods and less leaf material. Infection had no influence on the total concentration of neutral lipids. Contrary to what we expected based on laboratory findings, the nitrogen isotope signature, which allows for the estimation of consumer's trophic position, was not influenced by infection status. Conversely, the carbon isotope signature, which is used to identify food sources, changed with infection and suggested that the diet of infected G. roeseli includes less perilithon (i.e. fixed algae on rocks, stones) but more terrestrial inputs (e.g. leaf material) than that of uninfected conspecifics. This study shows evidence of changes in the trophic ecology of P. minutus-infected G. roeseli and we stress the need to complement feeding experiments with field data when investigating top-down effects of infection in an opportunistic feeder which adapts its diet to the available food sources. PMID:21232173

  19. Size at the onset of maturity (SOM) revealed in length-weight relationships of brackish amphipods and isopods: An information theory approach

    NASA Astrophysics Data System (ADS)

    Longo, Emanuela; Mancinelli, Giorgio

    2014-01-01

    In amphipods and other small-sized crustaceans, allometric relationships are conventionally analysed by fitting the standard model Y = a·Xb (X and Y are, e.g., body length and weight, respectively) whose scaling exponent b is assumed to be constant. However, breakpoints in allometric relationships have long been documented in large-sized crustaceans, ultimately determined by ontogenetic, abrupt variations in the value of b. Here, the existence of breakpoints in length-weight relationships was investigated in four amphipod (i.e., Gammarus aequicauda, Gammarus insensibilis, Microdeutopus gryllotalpa, and Dexamine spinosa) and three isopod species (i.e., Lekanesphaera hookeri, Sphaeroma serratum, and Cymodoce truncata) from three Mediterranean lagoons. The power of two candidate linear models fitted to log10-transformed data - a simple model assuming a constant exponent b and a segmented model assuming b to vary after a breakpoint - was compared using a parsimonious selection strategy based on the Akaike information criterion. The segmented model with a breakpoint provided the most accurate fitting of length-weight data in the majority of the species analysed; non-conclusive results were obtained only for D. spinosa and C. truncata, of which a limited number of specimens was examined. Model parameters were consistent for amphipod and isopod species collected across the three different habitats; the generality of the results was further supported by a literature search confirming that the identified breakpoints corresponded with ontogenetic discontinuities related with sexual maturation in all the species investigated. In this study, segmented regression models were revealed to provide a statistically accurate and biologically meaningful description of length-weight relationships of common amphipod and isopod species. The methodological limitations of the approach are considered, while the practical implications for secondary production estimates are discussed.

  20. Antioxidant enzyme activity in endemic Baikalean versus Palaearctic amphipods: tagma- and size-related changes.

    PubMed

    Timofeyev, M A

    2006-03-01

    The activities of key antioxidant enzymes in two endemic Baikalean amphipod species: Pallasea cancelloides (Gerstf), Eulimnogammarus verrucosus (Gerstf) and the widely distributed Palearctic species Gammarus lacustris (Sars) were studied. This work was done to prove or disprove the hypothesis that Baikalean endemics have specifics in antioxidants system different from Palearctic species. The activities of antioxidant enzymes peroxidase, catalase and glutathione-S-transferase were measured in different sections (tagmata) of the amphipods' bodies as well as in different size groups. Well expressed tagma-related differences in peroxidase activity as well as smaller differences in catalase activity were shown in all studied species. There were no measured differences in glutathione-S-transferase activity among body sections. The existence of size-related changes in some antioxidant enzymes and the difference in such changes between Baikalean and Palearctic amphipods were noted. A significant increase in peroxidase activity with the size was found in both Baikalean species while a significant decrease in peroxidase activity was observed in the Palearctic G. lacustris. In Baikalean P. cancelloides, a significant decrease of catalase activity with the increase in age of crustaceans was noted, while in E. verrucosus no such relationship was found. In the Palearctic G. lacustris, a significant increase in catalase activity with the increase in size was noted. All species are shown to have no size-related differences in glutathione-S-transferase activity. The differences between species as well as between both different tagmata and size-classes within a particular species were estimated. It was assumed that the estimated differences in enzymes activity most likely depend on interspecific variation, rather than on conditional specifics in Lake Baikal. PMID:16460977

  1. An integrated study on Gammarus elvirae (Crustacea, Amphipoda): perspectives for toxicology of arsenic-contaminated freshwater.

    PubMed

    Davolos, Domenico; Chimenti, Claudio; Ronci, Lucilla; Setini, Andrea; Iannilli, Valentina; Pietrangeli, Biancamaria; De Matthaeis, Elvira

    2015-10-01

    The Italian region Latium is characterized by extensive quaternary volcanic systems that contribute greatly to arsenic (As) contamination of freshwater, including drinking water supplies. However, knowledge of the possible toxic effects in these aquatic environments is, despite being highly relevant to public health, still limited. In this paper, we approach this issue using Gammarus elvirae, an amphipod species that inhabits rivers and streams in central Italy, including Latium. We explored the possibility of using G. elvirae in the toxicology of freshwater by addressing the most relevant issues. First, we tested the usefulness of hemocytes from G. elvirae in determining non-specific DNA damage by means of the Comet assay after exposure (24 h and 7 days) to different river water samples in Latium; second, we provided an interpretative overview of the usefulness of hepatopancreatic epithelial cells of G. elvirae as a means of assessing toxicity after long-term exposure to As and other pollutants; third, the LC (50-240 h) value for G. elvirae was estimated for arsenate, which is usually the dominant arsenic species in surface waters. Our study sheds light on G. elvirae at different levels, providing a background for future toxicological research of freshwater. PMID:26013740

  2. Quantifying diet-borne metal uptake in Gammarus pulex using stable isotope tracers.

    PubMed

    Pellet, Bastien; Ayrault, Sophie; Tusseau-Vuillemin, Marie-Hélène; Gourlay-Francé, Catherine

    2014-12-01

    Gammarids are aquatic amphipods widely used for water quality monitoring. To investigate the copper and cadmium diet-borne metal uptake in Gammarus pulex, we adapted the pulse-chase stable isotopes-based approach to determine the food ingestion rate (IR), the gut retention time (GRT) and the metal assimilation efficiencies (AE). G. pulex were fed with (65)Cu-, (106)Cd-, and (53)Cr-labeled alder leaves for 7.5h and then with unlabeled leaves for 5d. The metal stable isotope contents in the gammarids, leaves, filtered water and periodically collected feces were determined. Chromium was poorly assimilated by the gammarids; thus, Cr was used as an unassimilated tracer. The first tracer defecation occurred before the first feces harvest, indicating a gut passage time of less than 9h. A 24-h GRT and a 0.69gg(-1)d(-1) IR were estimated. The Cd AE value was estimated as 5-47%, depending on the assimilation determination method applied. The Cu AE value could not be evaluated regardless of the determination method used, most likely because of the rapid Cu regulation in gammarids in addition to analytical uncertainties when determining the Cu content in leaves. Application of the Cd AE value in the framework of the biodynamic bioaccumulation model shows that the diet-borne uptake of Cd significantly contributes (66-95%) to the metal bioaccumulation in G. pulex fed with alder leaves. PMID:25244686

  3. PHOXOCEPHALID AMPHIPOD BIOASSAY FOR MARINE SEDIMENT TOXICITY

    EPA Science Inventory

    The relative toxicity of marine sediment can be accurately determined through acute, static bioassays with the phoxocepalid amphipod Repoxynius abronius. Mortality and sublethal effects on emergence from sediment and reburial behavior are determined after ten day exposure in 1-L ...

  4. Grazing preferences of marine isopods and amphipods on three prominent algal species of the Baltic Sea [rapid communication

    NASA Astrophysics Data System (ADS)

    Goecker, Margene E.; Kåll, Sara E.

    2003-12-01

    Preference tests were performed over a two-week period in September 2001 in which isopods ( Idotea baltica) and amphipods ( Gammarus oceanicus) were offered choices of three common species of algae from the Baltic Sea: Enteromorpha intestinalis, Cladophora spp., and Fucus vesiculosus. After a 48-hour starvation period, 20 individuals of each grazer species were placed in aquaria containing approximately 1.0 g of each algal species. Fifteen trials for each grazer species were run for 20 hours. We found that G. oceanicus ate significantly more Cladophora spp. and E. intestinalis than F. vesiculosus (p<0.001), with a preference order of: Cladophora spp.> E. intestinalis> F. vesiculosus. Similarly, I. baltica ate significantly more of both the filamentous green algae than F. vesiculosus (p<0.001), with a preference order of: E. intestinalis> Cladophora spp.> F. vesiculosus. Given the preference of isopods and amphipods for filamentous green algae, we might expect these algae to be maintained at low biomass levels. However, this is clearly not the case in the Baltic Sea. Nutrient enrichment (bottom-up effects) is the accepted dominant reason for the non-controlling impact of algal grazers, but other reasons may include cascading trophic effects resulting from the removal of large piscivorous fish (top-down effects).

  5. Gill Na(+), K(+)-ATPase in a series of hyper-regulating gammarid amphipods: enzyme characterisation and the effects of salinity acclimation.

    PubMed

    Brooks, Steven J; Lloyd Mills, Chris

    2006-05-01

    The enzyme Na(+), K(+)-ATPase was investigated in the gills of selected hyper-regulating gammarid amphipods. Gill Na(+), K(+)-ATPase was characterised with respect to the main cation and co-factor concentrations for the freshwater amphipod Gammarus pulex. The optimum cation and co-factor concentrations for maximal gill Na(+), K(+)-ATPase activity in G. pulex were 100mM Na(+), 15mM K(+), 15mM Mg(2+) and 5mM ATP, at pH 7.2. The effects of salinity acclimation on gill Na(+), K(+)-ATPase activity and haemolymph sodium concentrations was investigated in selected gammarid amphipods from different salinity environments. Maximal enzyme activity occurred in all gammarids when acclimated to the most dilute media. This maximal activity coincided with the largest sodium gradient between the haemolymph and the external media. As the haemolymph/medium sodium gradient decreased, a concomitant reduction in gill Na(+), K(+)-ATPase activity occurred. This implicates the involvement of gill Na(+), K(+)-ATPase in the active uptake of sodium from dilute media in hyper-regulating gammarids. PMID:16516515

  6. Bioconcentration, biotransformation and elimination of pyrene in the arctic crustacean Gammarus setosus (Amphipoda) at two temperatures.

    PubMed

    Carrasco-Navarro, V; Jæger, I; Honkanen, J O; Kukkonen, J V K; Carroll, JoLynn; Camus, Lionel

    2015-09-01

    The influence of temperature on the bioaccumulation, toxicokinetics, biotransformation and depuration of pyrene was studied in the arctic marine amphipod Gammarus setosus. A two-compartment model was used to fit experimental values of total body burden, total metabolites and parent pyrene concentrations and to calculate toxicokinetic variables derived for two experimental treatments (2 and 8 °C). No statistically significant differences were observed with temperature for these toxicokinetic variables or bioconcentration factors. Contrarily, the Q10 values suggested that the toxicokinetic variables ke and km were temperature-dependent. This may be explained by the high standard deviation of the Q10 values. Q10 is the variation in the rate of a metabolic reaction with a 10 °C increase in temperature. Depuration rate constants were calculated from linear best fit equations applied to measured pyrene concentrations over time during the depuration phase of the experiment. During depuration, the parent pyrene was eliminated in two stages with faster elimination observed at 8 °C compared to 2 °C. This finding was also indicated by the Q10. No changes in total body burdens of metabolite concentrations were observed during the monitoring of depuration over a period of 96 h. The biotransformation pathway of pyrene in G. setosus was also investigated in this study with two main phase II biotransformation products discovered by liquid chromatography. These products are conditionally identified as the sulphate and glucose conjugates of 1-hydroxy-pyrene. Overall, the study contributes new knowledge to the understanding of the fate of PAHs in arctic biota. In particular, the study provides valuable insight into the bioaccumulation and biotransformation of an important PAH and its metabolites in a species that serves as both a predator and prey in the arctic ecosystem. PMID:26298708

  7. Pathologies of Oligacanthorhynchus pardalis (Acanthocephala, Oligacanthorhynchidae) in Leopardus tigrinus (Carnivora, Felidae) in Southern Brazil.

    PubMed

    Gallas, Moisés; da Silveira, Eliane Fraga; da Silvera, Eliane Fraga

    2012-01-01

    In Brazil, Oligacanthorhynchus pardalis (Westrumb, 1821) Schmidt, 1972 has been observed in five species of wild felines. In the present study, five roadkilled oncillas (Leopardus tigrinus Schreber, 1775) were collected in the State of Rio Grande do Sul, Brazil. Chronic lesions caused by O. pardalis were observed in the small intestine of one of the specimens. Histological examination identified a well-defined leukocyte infiltration and an area of collagenous fibrosis. Only males parasites (n = 5) were found, with a prevalence of 20%. The life cycle of Oligacanthorhynchus species is poorly known, although arthropods may be their intermediate hosts. The low prevalence encountered may be related to the small number of hosts examined, and the reduced ingestion of arthropods infected by larvae of O. pardalis. This is the first report of O. pardalis parasitizing L. tigrinus in the Brazilian state of Rio Grande do Sul. PMID:23070447

  8. Potential exposure routes and accumulation kinetics for poly- and perfluorinated alkyl compounds for a freshwater amphipod: Gammarus spp. (Crustacea).

    PubMed

    Bertin, Delphine; Labadie, Pierre; Ferrari, Benoît J D; Sapin, Alexandre; Garric, Jeanne; Geffard, Olivier; Budzinski, Hélène; Babut, Marc

    2016-07-01

    Gammarids were exposed to sediments from a deposition site located on the Rhône River (France) downstream of a fluoropolymer manufacturing plant. Gammarids accumulated to various extents four long-chain perfluoroalkyl carboxylic acids (PFCAs) from C9 to C13, one sulfonate, perfluorooctane sulfonate (PFOS) and three of its precursors (the perflurooctane sulfonamide (FOSA), the N-methyl perfluorooctane sulfonamidoacetic acid (MeFOSAA), the N-ethyl perfluorooctane sulfonamidoacetic acid (EtFOSAA) and the 6:2 fluorotelomer sulfonic acid (6:2 FTSA). Whatever the compound, the steady state was not achieved after a 3-week exposure; elimination was almost complete after a 3-week depuration period for perfluorononanoic acid (PFNA), PFOS, the three precursors and the 6:2FTSA. However, this was not the case for long-chain PFCAs, whose elimination rates decreased with increasing chain length. PFAS accumulation in gammarids occurred via the trophic and respiratory pathways, in proportions varying with the carbon chain length and the terminal moiety. PMID:27139118

  9. Gender differences in responses in Gammarus pulex exposed to BDE-47: A gel-free proteomic approach.

    PubMed

    Gismondi, E; Mazzucchelli, G; De Pauw, E; Joaquim-Justo, C; Thomé, J P

    2015-12-01

    Very few ecotoxicological studies have considered differences in toxic effects on male and female organisms. Here, we investigated protein expression differences in caeca of Gammarus pulex males and females under control conditions (unexposed) and after 96h exposure to BDE-47. Using gel-free proteomic analysis, we have identified 45 proteins, of which 25 were significantly differently expressed according to sex and/or BDE-47 exposure. These proteins were involved in several biological processes such as energy metabolism, chaperone proteins, or transcription/translation. In unexposed amphipods, 11 proteins were significantly over-expressed in females, and 6 proteins were over-expressed in males. Under BDE-47 stress, 7 proteins were differently impacted according to sex. For example, catalase was over-expressed in exposed females and under-expressed in exposed males, as compared to respective controls. Conversely, proteins involved in energy metabolism were up-regulated in males and down-regulated in females. Our proteomic study showed differences in responses of males and females to BDE-47 exposure, emphasizing that sex is a confounding factor in ecotoxicological assessment. However, due to the limited information existing in databases on Gammarids, it was difficult to define a BDE-47 mechanism of action. The gel-free proteomic seems to be a promising method to develop in future ecotoxicological studies and thus, to improve our understanding of the mechanism of action of xenobiotics. PMID:26256056

  10. Suspended particles only marginally reduce pyrethroid toxicity to the freshwater invertebrate Gammarus pulex (L.) during pulse exposure.

    PubMed

    Rasmussen, Jes Jessen; Cedergreen, Nina; Kronvang, Brian; Andersen, Maj-Britt Bjergager; Nørum, Ulrik; Kretschmann, Andreas; Strobel, Bjarne Westergaard; Hansen, Hans Christian Bruun

    2016-04-01

    Current ecotoxicological research on particle-associated pyrethroids in freshwater systems focuses almost exclusively on sediment-exposure scenarios and sediment-dwelling macroinvertebrates. We studied how suspended particles influence acute effects of lambda-cyhalothrin and bifenthrin on the epibenthic freshwater amphipod Gammarus pulex (L.) using brief pulse exposures followed by a 144 h post exposure recovery phase. Humic acid (HA) and the clay mineral montmorillonite (MM) were used as model sorbents in environmentally realistic concentrations (5, 25 and 125 mg L(-1)). Mortality of G. pulex was recorded during the post exposure recovery phase and locomotor behavior was measured during exposure to lambda-cyhalothrin. We found that HA in concentrations ≥25 mg L(-1) adsorbed the majority of pyrethroids but only reduced mortality of G. pulex up to a factor of four compared to pyrethroid-only treatments. MM suspensions adsorbed a variable fraction of pyrethroids (10% for bifenthrin and 70% for lambda-cyhalothrin) but did not significantly change the concentration-response relationship compared to pure pyrethroid treatments. Behavioral responses and immobilisation rate of G. pulex were reduced in the presence of HA, whereas behavioral responses and immobilisation rate were increased in the presence of MM. This indicates that G. pulex was capable of sensing the bioavailable fraction of lambda-cyhalothrin. Our results imply that suspended particles reduce to only a limited extent the toxicity of pyrethroids to G. pulex and that passive uptake of pyrethroids can be significant even when pyrethroids are adsorbed to suspended particles. PMID:26831865

  11. Assessing the reliability of uptake and elimination kinetics modelling approaches for estimating bioconcentration factors in the freshwater invertebrate, Gammarus pulex.

    PubMed

    Miller, Thomas H; McEneff, Gillian L; Stott, Lucy C; Owen, Stewart F; Bury, Nicolas R; Barron, Leon P

    2016-03-15

    This study considers whether the current standard toxicokinetic methods are an accurate and applicable assessment of xenobiotic exposure in an aquatic freshwater invertebrate. An in vivo exposure examined the uptake and elimination kinetics for eight pharmaceutical compounds in the amphipod crustacean, Gammarus pulex by measuring their concentrations in both biological material and in the exposure medium over a 96 h period. Selected pharmaceuticals included two anti-inflammatories (diclofenac and ibuprofen), two beta-blockers (propranolol and metoprolol), an anti-depressant (imipramine), an anti-histamine (ranitidine) and two beta-agonists (formoterol and terbutaline). Kinetic bioconcentration factors (BCFs) for the selected pharmaceuticals were derived from a first-order one-compartment model using either the simultaneous or sequential modelling methods. Using the simultaneous method for parameter estimation, BCF values ranged from 12 to 212. In contrast, the sequential method for parameter estimation resulted in bioconcentration factors ranging from 19 to 4533. Observed toxicokinetic plots showed statistically significant lack-of-fits and further interrogation of the models revealed a decreasing trend in the uptake rate constant over time for ranitidine, diclofenac, imipramine, metoprolol, formoterol and terbutaline. Previous published toxicokinetic data for 14 organic micro-pollutants were also assessed and similar trends were identified to those observed in this study. The decreasing trend of the uptake rate constant over time highlights the need to interpret modelled data more comprehensively to ensure uncertainties associated with uptake and elimination parameters for determining bioconcentration factors are minimised. PMID:26789375

  12. Invasion of the Upper Mississippi River System by Saltwater Amphipods

    EPA Science Inventory

    Zoobenthos surveys of the Great Rivers of the Upper Mississippi River basin (Missouri, Mississippi, and Ohio Rivers) provided an opportunity for documenting a series of invasions by euryhaline amphipods. The corophiid amphipod Apocorophium lacustre was first found in the Ohio Ri...

  13. Effects of the acanthocephalan Polymorphus minutus and the microsporidian Dictyocoela duebenum on energy reserves and stress response of cadmium exposed Gammarus fossarum

    PubMed Central

    Nachev, Milen; Shih, Hsiu-Hui; Sures, Bernd

    2015-01-01

    Amphipods are commonly parasitized by acanthocephalans and microsporidians and co-infections are found frequently. Both groups of parasites are known to have severe effects on their host. For example, microsporidians can modify host sex ratio and acanthocephalans can manipulate the behavior of the amphipod to promote transmission to the final host. These effects influence host metabolism in general and will also affect the ability of amphipods to cope with additional stressors such as environmental pollution, e.g., by toxic metals. Here we tested the effects of sub-lethal concentrations of cadmium on glycogen and lipid levels, as well as on the 70kDa heat shock protein (hsp70) response of field collected Gammarus fossarum, which were naturally infected with microsporidians and the acanthocephalan Polymorphus minutus. Infected and uninfected G. fossarum were exposed to a nominal Cd concentration of 4 µg/L, which resembled measured aqueous Cd concentration of 2.9 µg/L in reconstituted water for 7 d at 15 °C in parallel to an unexposed control. After exposure gammarids were snap frozen, weighed, sexed and tested for microsporidian infection by PCR. Only individuals containing the microsporidian Dictyocoela duebenum were used for the further biochemical and metal analyses. P. minutus infected amphipods were significantly smaller than their uninfected conspecifics. Mortality was insignificantly increased due to cadmium exposure, but not due to parasite infection. Microsporidian infection in combination with cadmium exposure led to increased glycogen levels in female gammarids. An increase of glycogen was also found due to interaction of acanthocephalan and microsporidian infection. Elevated lipid levels were observed in all groups infected with microsporidians, while acanthocephalans had the opposite effect. A positive correlation of lipid and glycogen levels was observed. The general stress response measured in form of hsp70 was significantly increased in

  14. Effects of the acanthocephalan Polymorphus minutus and the microsporidian Dictyocoela duebenum on energy reserves and stress response of cadmium exposed Gammarus fossarum.

    PubMed

    Chen, Hui-Yu; Grabner, Daniel S; Nachev, Milen; Shih, Hsiu-Hui; Sures, Bernd

    2015-01-01

    Amphipods are commonly parasitized by acanthocephalans and microsporidians and co-infections are found frequently. Both groups of parasites are known to have severe effects on their host. For example, microsporidians can modify host sex ratio and acanthocephalans can manipulate the behavior of the amphipod to promote transmission to the final host. These effects influence host metabolism in general and will also affect the ability of amphipods to cope with additional stressors such as environmental pollution, e.g., by toxic metals. Here we tested the effects of sub-lethal concentrations of cadmium on glycogen and lipid levels, as well as on the 70kDa heat shock protein (hsp70) response of field collected Gammarus fossarum, which were naturally infected with microsporidians and the acanthocephalan Polymorphus minutus. Infected and uninfected G. fossarum were exposed to a nominal Cd concentration of 4 µg/L, which resembled measured aqueous Cd concentration of 2.9 µg/L in reconstituted water for 7 d at 15 °C in parallel to an unexposed control. After exposure gammarids were snap frozen, weighed, sexed and tested for microsporidian infection by PCR. Only individuals containing the microsporidian Dictyocoela duebenum were used for the further biochemical and metal analyses. P. minutus infected amphipods were significantly smaller than their uninfected conspecifics. Mortality was insignificantly increased due to cadmium exposure, but not due to parasite infection. Microsporidian infection in combination with cadmium exposure led to increased glycogen levels in female gammarids. An increase of glycogen was also found due to interaction of acanthocephalan and microsporidian infection. Elevated lipid levels were observed in all groups infected with microsporidians, while acanthocephalans had the opposite effect. A positive correlation of lipid and glycogen levels was observed. The general stress response measured in form of hsp70 was significantly increased in

  15. Genetic diversity of microsatellite loci in Leopardus pardalis, Leopardus wiedii and Leopardus tigrinus.

    PubMed

    Grisolia, A B; Moreno, V R; Campagnari, F; Milazzotto, M P; Garcia, J F; Adania, C H; Souza, E B

    2007-01-01

    The microsatellite loci FCA045, FCA077, FCA008, and FCA096 are highly variable molecular markers which were used to determine the genetic diversity in 148 captive Leopardus sp. The PCR-amplified products of microsatellite loci were characterized in ABI Prism 310 Genetic Analyzer. Allele numbers, heterozygosity, polymorphism information content, exclusive allele number, and shared alleles were calculated. Sixty-five alleles were found and their sizes ranged from 116 to 216 bp in four microsatellite loci. The heterozygosity ranged from 0.36 to 0.81 in Leopardus pardalis, 0.57 to 0.67 in L. tigrinus and 0.80 to 0.92 in L. wiedii. The polymorphism information content was from 0.80 to 0.88 in L. pardalis, 0.76 to 0.88 in L. tigrinus and 0.77 to 0.90 in L. wiedii. The margay (L. wiedii) showed the highest index of polymorphism among the three species in this study. These results imply that microsatellite DNA markers can help in the study of the genetic diversity of Leopardus specimens. PMID:17624861

  16. Gammarus fossarum (Crustacea, Amphipoda) as a model organism to study the effects of silver nanoparticles.

    PubMed

    Mehennaoui, Kahina; Georgantzopoulou, Anastasia; Felten, Vincent; Andreï, Jennifer; Garaud, Maël; Cambier, Sébastien; Serchi, Tommaso; Pain-Devin, Sandrine; Guérold, François; Audinot, Jean-Nicolas; Giambérini, Laure; Gutleb, Arno C

    2016-10-01

    Amphipods are one of the most important components of freshwater ecosystems. Among them, gammarids are the most widespread group in Europe and are often used as bioindicators and model organisms in ecotoxicology. However, their use, especially of Gammarus fossarum for the study of the environmental impact of nanoparticles, has been rather limited so far. G. fossarum was selected to assess effects of well-characterized chemically synthesized silver nanoparticles (AgNPs 20nm and 200nm) and "green" laboratory synthetized (from plant leaf extracts) AgNPs (AgNPs 23nm and 27nm). AgNO3 was used as a positive control to compare AgNPs effects and silver ions effects. A multibiomarker approach was used to investigate the sub-lethal effects of AgNPs on physiological and behavioural responses of G. fossarum. Two different experiments were carried out. In a preliminary experiment, two populations of G. fossarum (G.f1 and G.f2) were tested for sensitivity differences and the most sensitive one was exposed, in a final experiment, to sub-lethal concentrations of AgNO3 and the most toxic AgNPs. AgNO3 and AgNPs 23nm led to a significant decrease in survival rates, osmoregulation and locomotor activity. Ag internalisation, performed with Secondary Ion Mass Spectrometry (SIMS), showed the presence of silver in gills of G.f2 exposed to AgNPs 23 and 27nm. This study highlighted the influence of method of synthesis on ion release, uptake and toxic effects of AgNPs on G. fossarum. Osmoregulation appeared to be an effective biomarker indicating the physiological health status of G. fossarum. Locomotor activity, which was the most impacted response, reflects the potential effects of released ions from AgNPs 23nm at the population level as locomotion is necessary for foraging, finding mates and escaping from predators. Therefore, we propose G. fossarum as a suitable model for environmental nanotoxicology, providing information both at individual and population levels. PMID:27328878

  17. A Laccase with HIV-1 Reverse Transcriptase Inhibitory Activity from the Broth of Mycelial Culture of the Mushroom Lentinus tigrinus

    PubMed Central

    Xu, LiJing; Wang, HeXiang; Ng, TziBun

    2012-01-01

    A 59 kDa laccase with inhibitory activity against HIV-1 reverse transcriptase (IC50 = 2.4 μM) was isolated from the broth of mycelial culture of the mushroom Lentinus tigrinus. The isolation procedure involved ion exchange chromatography on DEAE-cellulose and CM-cellulose, and gel filtration by fast protein liquid chromatography on Superdex 75. The laccase was adsorbed on both types of ion exchangers. About 95-fold purification was achieved with a 25.9% yield of the enzyme. The procedure resulted in a specific enzyme activity of 76.6 U/mg. Its N-terminal amino acid sequence was GIPDLHDLTV, which showed little similarity to other mushroom laccase and other Lentinus tigrinus strain laccase. Its characteristics were different from previously reported laccase of other Lentinus tigrinus strain. Maximal laccase activity was observed at a pH of 4 and at a temperature of 60°C, respectively. This study yielded the information about the potentially exploitable activities of Lentinus tigrinus laccase. PMID:22536022

  18. Influence of Natural Thermal Gradients on Whole Animal Rates of Protein Synthesis in Marine Gammarid Amphipods

    PubMed Central

    Rastrick, Samuel P. S.; Whiteley, Nia M.

    2013-01-01

    Although temperature is known to have an important effect on protein synthesis rates and growth in aquatic ectotherms held in the laboratory, little is known about the effects of thermal gradients on natural populations in the field. To address this issue we determined whole-animal fractional rates of protein synthesis (ks) in four dominant species of gammarid amphipods with different distributions along the coasts of Western Europe from arctic to temperate latitudes. Up to three populations of each species were collected in the summer and ks measured within 48 h. Summer ks values were relatively high in the temperate species, Gammarus locusta, from Portugal (48°N) and Wales (53°N) and were maintained across latitudes by the conservation of translational efficiency. In sharp contrast, summer ks remained remarkably low in the boreal/temperate species G. duebeni from Wales, Scotland (58°N) and Tromsø (70°N), probably as a temporary energy saving strategy to ensure survival in rapidly fluctuating environments of the high intertidal. Values for ks increased in acclimated G. duebeni from Scotland and Tromsø showing a lack of compensation with latitude. In the subarctic/boreal species, G. oceanicus, summer ks remained unchanged in Scotland and Tromsø but fell significantly in Svalbard (79°N) at 5°C, despite a slight increase in RNA content. At 79°N, mean ks was 4.5 times higher in the circumpolar species G. setosus than in G. oceanicus due to a doubling in RNA content. The relationship between whole-animal protein synthesis rates and natural thermal gradients is complex, varies between species and appears to be associated with local temperatures and their variability, as well as changes in other environmental factors. PMID:23544122

  19. Genotype Reconstruction of Paternity in European Lobsters (Homarus gammarus).

    PubMed

    Ellis, Charlie D; Hodgson, David J; André, Carl; Sørdalen, Tonje K; Knutsen, Halvor; Griffiths, Amber G F

    2015-01-01

    Decapod crustaceans exhibit considerable variation in fertilisation strategies, ranging from pervasive single paternity to the near-ubiquitous presence of multiple paternity, and such knowledge of mating systems and behaviour are required for the informed management of commercially-exploited marine fisheries. We used genetic markers to assess the paternity of individual broods in the European lobster, Homarus gammarus, a species for which paternity structure is unknown. Using 13 multiplexed microsatellite loci, three of which are newly described in this study, we genotyped 10 eggs from each of 34 females collected from an Atlantic peninsula in the south-western United Kingdom. Single reconstructed paternal genotypes explained all observed progeny genotypes in each of the 34 egg clutches, and each clutch was fertilised by a different male. Simulations indicated that the probability of detecting multiple paternity was in excess of 95% if secondary sires account for at least a quarter of the brood, and in excess of 99% where additional sire success was approximately equal. Our results show that multiple paternal fertilisations are either absent, unusual, or highly skewed in favour of a single male among H. gammarus in this area. Potential mechanisms upholding single paternal fertilisation are discussed, along with the prospective utility of parentage assignments in evaluations of hatchery stocking and other fishery conservation approaches in light of this finding. PMID:26566271

  20. Genotype Reconstruction of Paternity in European Lobsters (Homarus gammarus)

    PubMed Central

    Ellis, Charlie D.; Hodgson, David J.; André, Carl; Sørdalen, Tonje K.; Knutsen, Halvor; Griffiths, Amber G. F.

    2015-01-01

    Decapod crustaceans exhibit considerable variation in fertilisation strategies, ranging from pervasive single paternity to the near-ubiquitous presence of multiple paternity, and such knowledge of mating systems and behaviour are required for the informed management of commercially-exploited marine fisheries. We used genetic markers to assess the paternity of individual broods in the European lobster, Homarus gammarus, a species for which paternity structure is unknown. Using 13 multiplexed microsatellite loci, three of which are newly described in this study, we genotyped 10 eggs from each of 34 females collected from an Atlantic peninsula in the south-western United Kingdom. Single reconstructed paternal genotypes explained all observed progeny genotypes in each of the 34 egg clutches, and each clutch was fertilised by a different male. Simulations indicated that the probability of detecting multiple paternity was in excess of 95% if secondary sires account for at least a quarter of the brood, and in excess of 99% where additional sire success was approximately equal. Our results show that multiple paternal fertilisations are either absent, unusual, or highly skewed in favour of a single male among H. gammarus in this area. Potential mechanisms upholding single paternal fertilisation are discussed, along with the prospective utility of parentage assignments in evaluations of hatchery stocking and other fishery conservation approaches in light of this finding. PMID:26566271

  1. Standardization of some electrocardiographic parameters of captive leopard cats (Leopardus tigrinus).

    PubMed

    Oda, Sam Goldy Shoyama; Yamato, Ronaldo Jun; Fedullo, José Daniel Luzes; Leomil Neto, Moacir; Larsson, Maria Helena Matiko Akao

    2009-09-01

    Thirty-three captive leopard cats, Leopardus tigrinus, were anesthetized with xylazine (1-2 mg/kg) and ketamine (10 mg/kg), and electrocardiograph (ECG) tests were recorded in all leads with 1 cm = 1 mV sensibility and 25 mm/sec speed repeating DII lead at 50 mm/sec speed with the same sensibility. Results expressed by mean and standard deviation were: heart rate (HR) = 107 +/- 17 (bpm); P-wave = 0.048 +/- 0.072 (s) x 0.128 +/- 0.048 (mV); PR interval = 0.101 +/- 0.081 (s); QRS compound = 0.053 +/- 0.012 (s) x 1.446 +/- 0.602 (mV); QT interval = 0.231 +/- 0.028 (s); R-wave (CV6LL) = 1.574 +/- 0.527 (mV); R-wave (CV6LU) = 1.583 +/- 0.818 (mV); heart rhythm: normal sinus rhythm (15.2%), sinus rhythm with wandering pacemaker (WPM) (60.6%), sinus arrhythmia with WPM (24.2%); electric axis: between +30 degrees and +60 degrees (6.1%), +60 (6.1%), between +60 degrees and +90 degrees (57.6%), +90 degrees (9%), between +90 degrees and +120 degrees (21.2%); ST segment: normal (75.7%), elevation (18.2%), depression (6.1%); T-wave polarity (DII): positive (100%); T-wave (V10): absent (6.1%), negative (63.6%), positive (18.2%), and with interference (12.1%). Through ECG data comparison with other species, unique features of Leopardus tigrinus' (leopard cat) ECG parameters were detected. Some of the study animals presented with an R-wave amplitude that was indicative of left ventricle overload according to patterns for normal domestic cats (Felis cati). Echocardiographic exams revealed normal heart cavities' function and morphology. The aim of this study was to establish some electrocardiographic parameters of captive L. tigrinus. PMID:19746854

  2. Parasite-induced alteration of plastic response to predation threat: increased refuge use but lower food intake in Gammarus pulex infected with the acanothocephalan Pomphorhynchus laevis.

    PubMed

    Dianne, Lucile; Perrot-Minnot, Marie-Jeanne; Bauer, Alexandre; Guvenatam, Arnaud; Rigaud, Thierry

    2014-03-01

    Larvae of many trophically-transmitted parasites alter the behaviour of their intermediate host in ways that increase their probability of transmission to the next host in their life cycle. Before reaching a stage that is infective to the next host, parasite larvae may develop through several larval stages in the intermediate host that are not infective to the definitive host. Early predation at these stages results in parasite death, and it has recently been shown that non-infective larvae of some helminths decrease such risk by enhancing the anti-predator defences of the host, including decreased activity and increased sheltering. However, these behavioural changes may divert infected hosts from an optimal balance between survival and foraging (either seeking food or a mate). In this study, this hypothesis was tested using the intermediate host of the acanthocephalan parasite Pomphorhynchus laevis, the freshwater amphipod Gammarus pulex. We compared activity, refuge use, food foraging and food intake of hosts experimentally infected with the non-infective stage (acanthella), with that of uninfected gammarids. Behavioural assays were conducted in four situations varying in predation risk and in food accessibility. Acanthella-infected amphipods showed an increase in refuge use and a general reduction in activity and food intake. There was no effect of parasite intensity on these traits. Uninfected individuals showed plastic responses to water-borne cues from fish by adjusting refuge use, activity and food intake. They also foraged more when the food was placed outside the refuge. At the intra-individual level, refuge use and food intake were positively correlated in infected gammarids only. Overall, our findings suggest that uninfected gammarids exhibit risk-sensitive behaviour including increased food intake under predation risk, whereas gammarids infected with the non-infective larvae of P. laevis exhibit a lower motivation to feed, irrespective of predation risk

  3. Influence of cinnamon and catnip on the stereotypical pacing of oncilla cats (Leopardus tigrinus) in captivity.

    PubMed

    Resende, Letícia de S; Pedretti Gomes, Karla C; Andriolo, Artur; Genaro, Gelson; Remy, Gabriella L; Almeida Ramos, Valdir de

    2011-01-01

    Nonhuman animals in captivity can experience environmental privation that results in their exhibiting abnormal behaviors. Environmental enrichment techniques can help improve their welfare. This study investigated the behavior of 8 zoo-housed oncilla cats (Leopardus tigrinus) in response to 2 odors (catnip and cinnamon) introduced individually into the animals' enclosures for 3 consecutive days. Proportion of scans spent engaging in stereotypical pacing were compared before, during, and after treatments. The addition of cinnamon reduced the proportion of pacing during and after enrichment (Wilcoxon: Z = 3.16, p < .001; Z = 3.16, p < .001, respectively), indicating a prolonged effect of the enrichment on the animals' behavior. Catnip appears to have elicited no significant difference in the stereotypic pacing before, during, or after the enrichment (Friedman: X(2) = 2.69; p = .260). The results highlight the potential use of cinnamon as a method of environmental enrichment for small captive-housed cats. PMID:22044295

  4. Status of the amphipod Diporeia Spp. in Lake Superior, 2011

    EPA Science Inventory

    Amphipods of the genus Diporeia have historically been the dominant benthic macroinvertebrates in deeper waters of the Laurentian Great Lakes. Although Diporeia populations in the lower Great Lakes have experienced severe declines in recent years, densities have remained relativ...

  5. Subglacial refugia in Iceland enabled groundwater amphipods to survive glaciations.

    PubMed

    Kristjánsson, Bjarni K; Svavarsson, Jörundur

    2007-08-01

    An endemic family of subterranean amphipods (Crustacea) has recently been discovered in Iceland, in addition to a new species of a previously known amphipod family. These findings are remarkable because Iceland was covered by glaciers from about 2.6 million BP to about 10,000 BP and is isolated on the mid-Atlantic Ridge, far from the North American and European continents. We argue that there were subglacial refugia in Iceland during the Quaternary glacial period. The presence of subterranean amphipods, belonging to an old group with its present distribution mainly in North America and the Eurasian continent, indicates past contact of subterranean fresh waters of Iceland and the North Atlantic continent. The amphipods currently found in Iceland may have been present in Greenland at 40 Ma, when the precursor of Iceland drifted together with the hot spot (Iceland plume) from Greenland. PMID:17874379

  6. Novel Epibiotic Thiothrix Bacterium on a Marine Amphipod

    PubMed Central

    Gillan, David C.; Dubilier, Nicole

    2004-01-01

    Comparative analysis of the 16S rRNA gene and fluorescent in situ hybridization (FISH) was used to identify epibiotic filamentous bacteria living on the marine amphipod crustacean Urothoe poseidonis. The epibionts belong to the gamma proteobacteria and represent a novel marine phylotype within the genus Thiothrix. FISH and denaturing gradient gel electrophoresis revealed that the Thiothrix filaments are present on the majority of the amphipods examined. PMID:15184190

  7. Pharmaceuticals in the freshwater invertebrate, Gammarus pulex, determined using pulverised liquid extraction, solid phase extraction and liquid chromatography-tandem mass spectrometry.

    PubMed

    Miller, Thomas H; McEneff, Gillian L; Brown, Rebecca J; Owen, Stewart F; Bury, Nicolas R; Barron, Leon P

    2015-04-01

    The development, characterisation and application of a new analytical method for multi-residue PPCP determination in the freshwater amphipod, Gammarus pulex are presented. Analysis was performed using pulverised liquid extraction (PuLE), solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Qualitative method performance offered excellent limits of detection at <20 ng g(-1) for 18 out of 29 compounds. For quantitative application, linearity and precision were considered acceptable for 10 compounds across the ng-μg g(-1) range (R2≥0.99; ≤20% relative standard deviation respectively). The method was applied to the analysis of G. pulex and river water sourced from six tributaries of the River Thames. Carbamazepine, diazepam, nimesulide, trimethoprim and warfarin were determined in G. pulex samples at low ng g(-1) (dry weight) concentrations across these sites. Temazepam and diclofenac were also detected, but were not quantifiable. Six pharmaceuticals were quantified in surface waters across the eight sites at concentrations ranging from 3 to 344 ng L(-1). The possibility for confirmatory detection and subsequent quantification of pharmaceutical residues in benthic organisms such as G. pulex will enable further understanding on the susceptibility and ecological effects of PPCPs in the aquatic environment. PMID:25544334

  8. Proximate composition and functionality of the culinary-medicinal tiger sawgill mushroom, Lentinus tigrinus (higher Basidiomycetes), from the Philippines.

    PubMed

    Dulay, Rich Milton R; Arenas, Minerva C; Kalaw, Sofronio P; Reyes, Renato G; Cabrera, Esperanza C

    2014-01-01

    The proximate composition and functionality of Lentinus tigrinus were evaluated to establish and popularize this mushroom as functional food source. The evaluation of functionality focused on the antibacterial and hypoglycemic activities of the mushroom extracts. An acute single oral dose toxicity test in mice was used for its biosafety analysis. The pileus contained higher amounts of protein (25.9%), fat (2.1%), and ash (7.4%) and a higher energetic value (142.1 kcal/100 g) than the corresponding stipe, whereas the stipe contained higher amounts of total carbohydrates (67.7%), which consist of dietary fiber (63.0%) and reducing sugar (4.7%), than the pileus. Biosafety analysis confirmed that L. tigrinus is an edible mushroom species; it was found to be toxicologically safe in imprinting control region mice. The administration of lyophilized hot water extract of the fruiting body (both 100 and 250 mg/ kg doses) to diabetic mice significantly lowered the glucose level by 26.9% in the third week, which was significantly comparable to the results of the antidiabetic agent glibenclamide, which was used as a positive control. In vitro antibacterial assay showed that the ethanolic extract of the fruiting body and the immobilized secondary mycelia had high antibacterial activities against Staphylococcus aureus but not on Escherichia coli. Combining its useful nutrients and significant biological properties, L. tigrinus can be considered a natural source of safe nutraceuticals. PMID:24940907

  9. Lentinus (Panus) tigrinus augmentation of a historically contaminated soil: matrix decontamination and structure and function of the resident bacterial community.

    PubMed

    Federici, E; Giubilei, M A; Cajthaml, T; Petruccioli, M; D'Annibale, A

    2011-02-28

    The ability of Lentinus tigrinus to grow and to degrade persistent aromatic hydrocarbons in aged contaminated soil was assessed in this study. L. tigrinus extensively colonized the soil; its degradation activity after 60 d incubation at 28°C, however, was mostly limited to dichloroaniline isomers, polychlorinated benzenes and diphenyl ether while the fungus was unable to deplete 9,10-anthracenedione and 7-H-benz[DE]anthracene-7-one which were the major soil contaminants. Although clean-up levels were limited, both density of cultivable heterotrophic bacteria and richness of the resident bacterial community in L. tigrinus microcosms (LtM) increased over time to a significantly larger extent than the respective amended incubation controls (1.9×10(9) CFU g(-1) vs. 1.0×10(9) CFU g(-1) and 37 vs. 16, respectively). Naphthalene- and catechol 2,3-dioxygenase gene copy numbers, however, decreased over time at a higher rate in LtM than in incubation controls likely due to a higher stimulation on heterotrophs than xenobiotics-degrading community members. PMID:21177025

  10. EFFECTS OF NATURAL SEDIMENT FEATURES ON SURVIVAL OF THE PHOXOCEPHALID AMPHIPOD, RHEPOXYNIUS ABRONIUS

    EPA Science Inventory

    Effects of sediment particle size and water content on the survival of the amphipod. hepoxynius abronius were examined by manipulating these natural sediment features within static laboratory microcosms. ean amphipod survival in fine uncontaminated field sediments (>/ 80% silt-cl...

  11. Identifying a key host in an acanthocephalan-amphipod system.

    PubMed

    Bauer, Alexandre; Rigaud, Thierry

    2015-11-01

    Trophically transmitted parasites may use multiple intermediate hosts, some of which may be 'key-hosts', i.e. contributing significantly more to the completion of the parasite life cycle, while others may be 'sink hosts' with a poor contribution to parasite transmission. Gammarus fossarum and Gammarus roeseli are sympatric crustaceans used as intermediate hosts by the acanthocephalan Pomphorhynchus laevis. Gammarus roeseli suffers higher field prevalence and is less sensitive to parasite behavioural manipulation and to predation by definitive hosts. However, no data are available on between-host differences in susceptibility to P. laevis infection, making it difficult to untangle the relative contributions of these hosts to parasite transmission. Based on results from estimates of prevalence in gammarids exposed or protected from predation and laboratory infections, G. fossarum specimens were found to be more susceptible to P. laevis infection. As it is more susceptible to both parasite infection and manipulation, G. fossarum is therefore a key host for P. laevis transmission. PMID:26303006

  12. Impact of cadmium on the ecdysteroids production in Gammarus fossarum.

    PubMed

    Abidi, Sondes; Abbaci, Khedidja Tair; Geffard, Olivier; Boumaiza, Moncef; Dumet, Adeline; Garric, Jeanne; Mondy, Nathalie

    2016-07-01

    Gammarus fossarum is an important test organism which is currently used as a bio-indicator as well as in ecotoxicological tests. Nevertheless, data on ecdysteroids in endocrine toxicity test are not yet available for these species, despite its crucial role in molting and reproduction. In the present paper, ecdysteroids concentrations were studied during the molt cycle (in females) and embryonic development in G. fossarum (Crustacea, Amphipoda) in order to propose an ecdysteroids toxicity test. Ecdysteroids levels in G. fossarum showed a single peak during premolt at stage Dl-D2. In embryos, ecdysteroids levels progressively increased over stages 3 and 4, with peak levels at stage 4. A Cadmium toxicity test was proposed to examine if the molting and embryogenesis disturbances previously observed after cadmium exposure (Geffard et al. 2010) could be attributed to changes in ecdysteroids titers. Exposure to the different cadmium concentrations (3; 9; 300; 900 µg/l) increased ecdysteroids secretion by Y-organs in vitro, but it had no significant effect on exposed embryos (in vivo). Based on previous findings, we are led to conclude that the molting impairments in cadmium-exposed females of G. fossarum is connected to the changes in ecdysteroids concentrations. PMID:26980586

  13. A FIELD VALIDATION OF TWO SEDIMENT-AMPHIPOD TOXICITY TESTS

    EPA Science Inventory

    A field validation study of two sediment-amphipod toxicity tests was conducted using sediment samples collected subtidally in the vicinity of a polycyclic aromatic hydrocarbon (PAH)-contaminated Superfund site in Elliott Bay, WA, USA. Sediment samples were collected at 30 stati...

  14. INGESTION AND ADSORPTION OF 'BACILLUS THURINGIENSIS' SUBSP. 'ISRAELENSIS' BY 'GAMMARUS LACUSTRIS' IN THE LABORATORY

    EPA Science Inventory

    Several groups of Gammarus lacustris adults were exposed to solutions containing 0.5 and 5.0 mg of Bacillus thuringiensis subsp. israelensis per liter for 1- or 24-hour periods by using traditional static bioassay exposure procedures. The experiments verified that traditional exp...

  15. The impact of natural and anthropogenic Dissolved Organic Carbon (DOC), and pH on the toxicity of triclosan to the crustacean Gammarus pulex (L.).

    PubMed

    Rowett, Christopher J; Hutchinson, Thomas H; Comber, Sean D W

    2016-09-15

    Regulatory ecotoxicology testing rarely accounts for the influence of natural water chemistry on the bioavailability and toxicity of a chemical. Therefore, this study identifies whether key omissions in relation to Dissolved Organic Carbon (DOC) and pH have an impact on measured effect concentrations (EC). Laboratory ecotoxicology tests were undertaken for the widely used antimicrobial compound triclosan, using adult Gammarus pulex (L.), a wild-type amphipod using synthetic fresh water, humic acid solutions and wastewater treatment works effluent. The toxicity of triclosan was tested at two different pHs of 7.3 and 8.4, with and without the addition of DOC and 24 and 48hour EC values with calculated 95% confidence intervals calculated. Toxicity tests undertaken at a pH above triclosan's pKa and in the presents of humic acid and effluent, containing 11 and 16mgL(-1) mean DOC concentrations respectively, resulted in significantly decreased triclosan toxicity. This was most likely a result of varying triclosan speciation and complexation due to triclosan's pKa and high hydrophobicity controlling its bioavailability. The mean 48hour EC50 values varied between 0.75±0.45 and 1.93±0.12mgL(-1) depending on conditions. These results suggest that standard ecotoxicology tests can cause inaccurate estimations of triclosan's bioavailability and subsequent toxicity in natural aquatic environments. These results highlight the need for further consideration regarding the role that water chemistry has on the toxicity of organic contaminants and how ambient environmental conditions are incorporated into the standard setting and consenting processes in the future. PMID:27173840

  16. Biobleaching of Acacia kraft pulp with extracellular enzymes secreted by Irpex lacteus KB-1.1 and Lentinus tigrinus LP-7 using low-cost media.

    PubMed

    Afrida, Sitompul; Tamai, Yutaka; Watanabe, Toshihiro; Osaki, Mitsuru

    2014-08-01

    The white-rot fungi Irpex lacteus KB-1.1 and Lentinus tigrinus LP-7 have been shown in previous studies to have high biobleaching activity in vivo. The aim of this study was to investigate the activities and stabilities of extracellular enzymes, prepared from I. lacteus and L. tigrinus culture grown in three types of economical media of agricultural and forestry wastes, for biobleaching of Acacia oxygen-delignified kraft pulp using kappa number reduction as an indicator of delignification. After 3 days of incubation, the extracellular enzymes preparations from I. lacteus and L. tigrinus cultures in media of Acacia mangium wood powder supplemented with rice bran and addition 1 % glucose (WRBG), resulted in significant decrease of 4.4 and 6.7 %, respectively. A slightly higher kappa number reduction (7.4 %) was achieved with the combine extracellular enzymes from I. lacteus and L. tigrinus. One of the strategies for reducing the cost of enzyme production for treatment processes in the pulp and paper industry is the utilization of agricultural and forestry waste. Thus, WRBG has potential as a culture medium for producing stable lignolytic enzymes simply and economically. PMID:24699808

  17. Scavenging amphipods from under the Ross Ice Shelf, Antarctica

    NASA Astrophysics Data System (ADS)

    Stockton, William L.

    1982-07-01

    Amphipods in the genus Orchomene were collected from under the Ross Ice Shelf, Antarctica, 400 km from the shelf edge at a depth of 600 m. A study of 992 individuals of the 3500 captured revealed that the population is dominated by the larger size classes. Two-thirds of the population is composed of males. Ovigerous females will approach and consume bait and females are multiply brooded. The source of nutrition for this population is not definitely known. Identifiable gut contents were bacteria mixed with sediment, pieces of crustacean carapaces, and tissue from apparently cannibalized conspecifics. It is an open question as to whether the population sampled is persistent over time and whether amphipods are common under all of the Ross Ice Shelf.

  18. Parasite-induced alteration of odour responses in an amphipod-acanthocephalan system.

    PubMed

    Stone, Charles F; Moore, Janice

    2014-11-01

    Odour-related behaviours in aquatic invertebrates are important and effective anti-predator behaviours. Parasites often alter invertebrate host behaviours to increase transmission to hosts. This study investigated the responses of the amphipod Hyalella azteca when presented with two predator chemical cues: (i) alarm pheromones produced by conspecifics and (ii) kairomones produced by a predatory Green Sunfish (Lepomis cyanellus). We compared the responses of amphipods uninfected and infected with the acanthocepalan parasite Leptorhynchiodes thecatus. Uninfected amphipods reduced activity and increased refuge use after detecting both the alarm pheromones and predator kairomones. Infected amphipods spent significantly more time being active and less time on the refuge than uninfected amphipods, and behaved as if they had not detected the chemical stimulus. Therefore, L. thecatus infections disrupt the amphipods' anti-predator behaviours and likely make their hosts more susceptible to predation. PMID:25200352

  19. Extraordinary micro-endemism in Australian desert spring amphipods.

    PubMed

    Murphy, N P; Adams, M; Guzik, M T; Austin, A D

    2013-03-01

    Increasing pressure for water in the Australian arid zone is placing enormous stress on the diverse endemic communities inhabiting desert springs. Detailed information about the evolutionary processes occurring within and between individual endemic species will help to develop effective and biologically relevant management strategies this fragile ecosystem. To help determine conservation priorities, we documented the genetic structure of the endemic freshwater amphipod populations in springs fed by the Great Artesian Basin in central Australia. Phylogenetic and phylogeographic history and genetic diversity measures were examined using nuclear and mitochondrial DNA from approximately 500 chiltoniid amphipods across an entire group of springs. Pronounced genetic diversity was identified, demonstrating that levels of endemism have been grossly underestimated in these amphipods. Using the GMYC model, 13 genetically divergent lineages were recognized as Evolutionarily Significant Units (ESUs), all of which could be considered as separate species. The results show that due to the highly fragmented ecosystem, these taxa have highly restricted distributions. Many of the identified ESUs are endemic to a very small number of already degraded springs, with the rarest existing in single springs. Despite their extraordinarily small ranges, most ESUs showed relative demographic stability and high levels of genetic diversity, and genetic diversity was not directly linked to habitat extent. The relatively robust genetic health of ESUs does not preclude them from endangerment, as their limited distributions ensure they will be highly vulnerable to future water extraction. PMID:23142695

  20. Polarotaxis and scototaxis in the supratidal amphipod Platorchestia platensis.

    PubMed

    Cohen, Jonathan H; Putts, Meagan R

    2013-08-01

    Talitrid amphipods use many cues for orientation during forays between temporary burrows and feeding areas, and for locating beaches when submerged, with visual cues being particularly important. Little evidence exists for polarized light among these visual cues despite extensive orientation by celestial and underwater polarized light in other crustaceans and in insects. We used electroretinography to assess spectral sensitivity in the eye of the beach flea Platorchestia platensis, and behavioral studies to test whether linearly polarized light serves as an orientation cue. Two spectral classes were present in the P. platensis eye with maxima at 431 and 520 nm. Non-uniform orientation of amphipods in the laboratory arena required either light/dark or polarized cues. Scototactic movements depended on arena conditions (day/night, wet/dry), while orientation under linearly polarized light was wavelength-dependent and parallel to the e-vector. Subsequent tests presented conflicting and additive scototactic and polarotactic cues to differentiate among these responses. In dry conditions, orientation parallel to the polarization e-vector overcame a dominant negative scototaxis, confirming that polarotaxis and scototaxis are separate orientation responses in this species. These behavioral results demonstrate talitrid amphipods can perceive and orient to linearly polarized light, and may use it to orient toward preferred zones on beaches. PMID:23653016

  1. Evaluation of toxicity: Whole-sediment versus overlying-water exposures with amphipod Hyalella azteca

    USGS Publications Warehouse

    Ingersoll, C.G.; Ivey, C.D.; Brunson, E.L.; Hardesty, D.K.; Kemble, N.E.

    2000-01-01

    A laboratory study was conducted to evaluate the toxicity of whole-sediment versus overlying-water exposures to the amphipod Hyalella azteca using field-collected sediments. Severe toxic effects (5-63% survival) were observed with amphipods exposed for 10 d in direct contact with sediment. In contrast, amphipods exposed only to overlying water in these sediment exposures did not exhibit any toxic effects.

  2. Are European lobsters (Homarus gammarus) susceptible to infection by a temperate Hematodinium sp.?

    PubMed

    Davies, Charlotte E; Rowley, Andrew F

    2015-05-01

    Hematodinium spp. infect over 40 species of crustaceans worldwide, but have not been reported to infect the European lobster, Homarus gammarus. In this study, Hematodinium parasites (a mixture of uni- and multinucleate trophont-like stages) were taken from donor crabs (Cancer pagurus) and injected into juvenile H. gammarus. Juvenile C. pagurus were also injected with the same inoculum. Haemolymph was taken at regular intervals and examined for the presence of Hematodinium using light microscopy and PCR, in two separate experiments of duration 4 and 8months. All lobsters were negative for Hematodinium whilst the C. pagurus challenged became infected. It is concluded that European lobsters are not susceptible to infection with a clade of Hematodinium that infects C. pagurus. PMID:25721169

  3. DIFFERENTIAL DISPLAY ANALYSES OF THE AMPHIPOD HYALELLA AZTECA EXPOSED TO ETHYNYLESTRADIOL AT THREE DIFFERENT TROPHIC LEVELS

    EPA Science Inventory

    A study was conducted to determine if differential display could be used to detect differences in gene expression in the amphipod, Hyalella azteca. In a study of synthetic estrogen attenuation in different aquatic media, amphipods were exposed to 20 ng/L 17 a-ethynylestradiol in...

  4. Submerged and solid-state production of laccase and Mn-peroxidase by Panus tigrinus on olive mill wastewater-based media.

    PubMed

    Fenice, Massimiliano; Giovannozzi Sermanni, Giovanni; Federici, Federico; D'Annibale, Alessandro

    2003-01-01

    The possible use of olive-mill wastewater (OMW) as a growth medium for the production of extracellular laccase and manganese peroxidase (MnP) from the white-rot fungus Panus tigrinus (P. tigrinus) CBS 577.79 was studied using a properly formulated OMW-based medium (2-fold diluted OMW supplemented with 0.5% sucrose and 0.1% yeast extract) either in a stirred-tank or an air-lift reactor. Solid-state fermentation (SSF) was also performed in a rotary drum reactor using maize stalks moistened with the OMW-based medium. Highest levels of laccase and manganese peroxidase activity were obtained in the stirred-tank reactor (4600+/-98 U l(-1) on day 13) and in the air-lift reactor (410+/-22 on day 7), respectively. Based on total enzyme activities, SSF appears to be more suitable than LSF but the latter exhibits better volumetric productivities. PMID:12413788

  5. A potential new estuarine amphipod test species from Europe

    SciTech Connect

    Quintino, V.M.S.; Re, A.

    1995-12-31

    Sediment toxicity testing is of recognized value, however tests do not exist for all ecoregions. In particular, there is a paucity of test species for estuarine conditions. To date such testing has been conducted using either Microtox or the Pacific amphipod, Eohaustorius estuarius. There are no other test species for which developed tests exist, which can tolerate the full range of estuarine salinities (0 to 35 ppt). The authors report testing with the Atlantic amphipod, Corophium multisetosum, which can survive well from 0 to 35 ppt. At the time of writing this abstract, initial testing has indicated appropriate dose-response relationships with the reference toxicant cadmium chloride, and an acute 10-day protocol has been successfully conducted at a range of test temperatures (15--22 C) and with salinities of 0.0, 0.2, 0.4, 0.8, 1.6, 3.2, 6.5, 12.5, 25.0, 50.0 and 100.0%. Work presently underway and expected to be reported at the World Congress includes finalization of methods development for acute (10-d static) testing, namely the sensitivity to a range of fines content in the sediment, and initiation of chronic (growth, reproduction success) testing.

  6. Quantification of emerging micropollutants in an amphipod crustacean by nanoliquid chromatography coupled to mass spectrometry using multiple reaction monitoring cubed mode.

    PubMed

    Sordet, Martin; Berlioz-Barbier, Alexandra; Buleté, Audrey; Garric, Jeanne; Vulliet, Emmanuelle

    2016-07-22

    An innovative analytical method has been developed to quantify the bioaccumulation in an amphipod crustacean (Gammarus fossarum) of three micropollutants regarded as anthropic-pollution markers: carbamazepine, oxazepam, and testosterone. A liquid-liquid extraction assisted by salts, known as QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) was miniaturised and optimised, so it could be adapted to the low mass samples (approximatively 5mg dry weight). For this same reason and in order to obtain good sensitivity, ultra-trace analyses were carried out by means of nanoliquid chromatography. A preconcentration system by on-column trapping was optimised to increase the injection volume. In order to improve both sensitivity and selectivity, the multiple reaction monitoring cubed mode analyses (MRM(3)) were carried out, validated and compared to the classic MRM. To the best of our knowledge, this is the first time that MRM(3) is coupled to nanoliquid chromatography for the analysis and detection of organic micropollutants <300Da. The optimised extraction method exhibited recoveries superior to 80%. The limits of quantification of the target compounds were 0.3, 0.7 and 4.7ng/g (wet weight) for oxazepam, carbamazepine and testosterone, respectively and the limits of detection were 0.1, 0.3 and 2.2ng/g (wet weight), respectively. The intra- and inter-day precisions were inferior to 7.7% and 10.9%, respectively, for the three levels of concentration tested. The analytical strategy developed allowed to obtain limits of quantification lower than 1ng/g (wet weight) and to establish the kinetic bioconcentration of contaminants within G. fossarum. PMID:27324621

  7. The legacy of a vanished sea: a high level of diversification within a European freshwater amphipod species complex driven by 15 My of Paratethys regression.

    PubMed

    Mamos, Tomasz; Wattier, Remi; Burzyński, Artur; Grabowski, Michał

    2016-02-01

    The formation of continental Europe in the Neogene was due to the regression of the Tethys Ocean and of the Paratethys Sea. The dynamic geology of the area and repetitious transitions between marine and freshwater conditions presented opportunities for the colonization of newly emerging hydrological networks and diversification of aquatic biota. Implementing mitochondrial and nuclear markers in conjunction with a large-scale sampling strategy, we investigated the impact of this spatiotemporal framework on the evolutionary history of a freshwater crustacean morphospecies. The Gammarus balcanicus species complex is widely distributed in the area previously occupied by the Paratethys Sea. Our results revealed its high diversification and polyphyly in relation to a number of other morphospecies. The distribution of the studied amphipod is generally characterized by very high local endemism and divergence. The Bayesian time-calibrated reconstruction of phylogeny and geographical distribution of ancestral nodes indicates that this species complex started to diversify in the Early Miocene in the central Balkans, partially in the shallow epicontinental sea. It is possible that there were several episodes of inland water colonization by local brackish water lineages. Subsequent diversification within clades and spread to new areas could have been induced by Alpine orogeny in the Miocene/Pliocene and, finally, by Pleistocene glaciations. The present distribution of clades, in many cases, still reflects Miocene palaeogeography of the area. Our results point out that investigations of the historical aspect of cryptic diversity in other taxa may help in a general understanding of the origins of freshwater invertebrate fauna of Europe. PMID:26615060

  8. Biodegradation potential and ligninolytic enzyme activity of two locally isolated Panus tigrinus strains on selected agro-industrial wastes.

    PubMed

    Ruqayyah, Tijani I D; Jamal, Parveen; Alam, Md Zahangir; Mirghani, Md Elwathig S

    2013-03-30

    The degradation potential and ligninolytic enzyme production of two isolated Panus tigrinus strains (M609RQY and M109RQY) were evaluated in this study. These strains were grown on three selected abundant agro-industrial wastes (rice straw; rice husk and cassava peel) under solid-state fermentation conditions. Degradation potential was determined by analyzing the chemical composition of the selected substrates before and after fermentation along with ligninolytic enzyme production. The strain M609RQY led to the highest lignin degradation of 40.81% on cassava peel, 11.25% on rice husk and 67.96% on rice straw. Both strains significantly increased the protein content of cassava peel. Rice husk stimulated maximum laccase (2556 U/L) and lignin peroxidase (24 U/L) production by the strains M109RQY and M609RQY, respectively. Furthermore, cassava peel stimulated maximum manganese-dependent peroxidase (141 U/L) production by the strain M109RQY. The de-lignified rice straw and the nutritionally-improved cassava peel could serve as potential animal feed supplements. PMID:23422153

  9. Development of a chronic sediment toxicity test for marine benthic amphipods

    SciTech Connect

    DeWitt, T.H.; Redmond, M.S.; Sewall, J.E.; Swartz, R.C.

    1992-12-01

    The results of the research effort culminated in the development of a research method for assessing the chronic toxicity of contaminated marine and estuarine sediments using the benthic amphipod, Leptocheirus plumulosus. The first chapter describes the efforts at collecting, handling, and culturing four estuarine amphipods from Chesapeake Bay, including L. plumulosus. This chapter includes maps of the distribution and abundance of these amphipods within Chesapeake Bay and methodologies for establishing cultures of amphipods which could be readily adopted by other laboratories. The second chapter reports the development of acute and chronic sediment toxicity test methods for L. plumulosus, its sensitivity to non-contaminant environmental variables, cadmium, two polynuclear aromatic hydrocarbons, and contaminated sediment from Baltimore Harbor, MD. The third chapter reports the authors attempts to develop a chronic sediment toxicity test with Ampelisca abdita.

  10. CHRONIC EFFECTS OF THE HERBICIDE DIURON ON FRESHWATER CLADOCERANS,AMPHIPODS,MIDGES,MINNOWS,WORMS, AND SNAILS

    EPA Science Inventory

    The chronic effects of the herbicide diuron on survival and reproduction of Daphnia pulex, and survival and growth of the amphipod Hyalella azteca, the midge Chironomus tentans, juvenile and embro/larval fathead minnows, Pimephales promelas, annelid worms, Lumbriculus variegatus,...

  11. Biomass and production of amphipods in low alkalinity lakes affected by acid precipitation.

    PubMed

    France, R L

    1996-01-01

    Population biomass and production of the amphipod Hyalella azteca (Saussure) were found to be related to alkalinity (ranging from 0.2 to 58.1 mg liter(-1)) in 10 Canadian Shield lakes in south-central Ontario. Biomass and production of amphipods in the two lakes characterized by spring depressions of pH below 5.0 were found to be lower than those for populations inhabiting lakes that did not experience such acid pulses. The proportional biomass of amphipods in relation to the total littoral zoobenthos community was lower in lakes of low alkalinity than in circumneutral or hardwater lakes. Because production in these amphipod populations is known to depend closely on population abundance, the labour-intensive derivation of production rates yields relatively little information for biomonitoring that cannot be obtained from abundance data alone. PMID:15093505

  12. Status of the Amphipod Diporeia spp. in Lake Superior, poster presentation

    EPA Science Inventory

    The amphipod Diporeia has historically been the dominant benthic macroinvertebrate in deeper waters of the Laurentian Great Lakes. Although Diporeia populations in the lower Great Lakes have experienced severe declines in recent years, densities have remained relatively stable i...

  13. TOXICOLOGICAL INTERACTIONS OF CHLORPYRIFOS AND METHYL MERCURY IN THE AMPHIPOD, HYALELLA AZTECA

    EPA Science Inventory

    The mechanism of interaction between chlorpyrifos, an organo-phosphate insecticide, and methyl mercury, an organometal, was assessed utilizing the amphipod, Hyalella azteca. Previous studies have demonstrated that chlorpyrifos and methyl mercury interact additively, with survival...

  14. A REFORMULATED, RECONSTITUTED WATER FOR TESTING THE FRESHWATER AMPHIPOD, HYALELLA AZTECA

    EPA Science Inventory

    Toxicity testing with the freshwater amphipod, Hyalella azteca, has routinely been conducted using nonstandard waters. Four waters tested for acceptability for aqueous reference toxicant testing with H. azteca. These included three formulated (standardized) waters: moderately har...

  15. Influence of Molting and Starvation on Digestive Enzyme Activities and Energy Storage in Gammarus fossarum

    PubMed Central

    Charron, Laetitia; Geffard, Olivier; Chaumot, Arnaud; Coulaud, Romain; Jaffal, Ali; Gaillet, Véronique; Dedourge-Geffard, Odile; Geffard, Alain

    2014-01-01

    Among the many biological responses studied in ecotoxicology, energy-based biomarkers such as digestive enzyme activities and energy reserves appear to be useful predictive tools for detecting physiological disturbances in organisms. However, the use of these biological responses as biomarkers could be limited by the effects of confounding factors (biotic and abiotic) and physiological processes, such as the reproductive cycle. Thus, the optimal use of these biomarkers will be facilitated by understanding the effects of these factors on the energy metabolism of the sentinel species being studied. We considered abiotic factors (temperature and conductivity) in a previous study, whereas the present study investigated the effects of gender, the female reproductive stage, and food availability on the digestive enzyme activities and energy storage of Gammarus fossarum. The results indicated that, during the female reproductive cycle, the activities of digestive enzymes (amylase, cellulase, and trypsin) decreased significantly, whereas the levels of reserves (proteins, lipids, and sugar) increased until the last premolt stage. Restricted food diets only led to decreased amylase activities in both sexes. Food starvation also induced a decrease in the energy outcomes in females, whereas there were no effects in males. In general, the biochemical (digestive enzyme activities) and physiological (energy reserves) responses were more stable in males than in females. These results support the use of males fed ad libitum to limit the effects of confounding factors when using these energy biomarkers in Gammarus fossarum during biomonitoring programs. PMID:24788197

  16. Ovary and embryo proteogenomic dataset revealing diversity of vitellogenins in the crustacean Gammarus fossarum.

    PubMed

    Trapp, Judith; Gaillard, Jean-Charles; Chaumot, Arnaud; Geffard, Olivier; Pible, Olivier; Armengaud, Jean

    2016-09-01

    Ovaries and embryos from sexually mature Gammarus fossarum were sampled at different stages of the reproductive cycle. The soluble proteome was extracted for five biological replicates and samples were subjected to trypsin digestion. The resulting peptides were analyzed by high resolution tandem mass spectrometry with a LTQ-Orbitrap XL instrument. The MS/MS spectra were assigned with a previously described RNAseq-derived G. fossarum database. The proteins highlighted by proteogenomics were monitored and their abundance kinetics over the different stages revealed a large panel of vitellogenins. Criteria were i) accumulation during oogenesis, ii) decrease during embryogenesis, iii) classified as female-specific, and iv) sequence similarity and phylogenetic analysis. The data accompanying the manuscript describing the database searches and comparative analysis ("High-throughput proteome dynamics for discovery of key proteins in sentinel species: unsuspected vitellogenins diversity in the crustacean Gammarus fossarum" by Trapp et al. [1]) have been deposited to the ProteomeXchange via the PRIDE repository with identifiers PRIDE: PXD001002. PMID:27547807

  17. Diversity and Distribution of Freshwater Amphipod Species in Switzerland (Crustacea: Amphipoda)

    PubMed Central

    Altermatt, Florian; Alther, Roman; Fišer, Cene; Jokela, Jukka; Konec, Marjeta; Küry, Daniel; Mächler, Elvira; Stucki, Pascal; Westram, Anja Marie

    2014-01-01

    Amphipods are key organisms in many freshwater systems and contribute substantially to the diversity and functioning of macroinvertebrate communities. Furthermore, they are commonly used as bioindicators and for ecotoxicological tests. For many areas, however, diversity and distribution of amphipods is inadequately known, which limits their use in ecological and ecotoxicological studies and handicaps conservation initiatives. We studied the diversity and distribution of amphipods in Switzerland (Central Europe), covering four major drainage basins, an altitudinal gradient of>2,500 m, and various habitats (rivers, streams, lakes and groundwater). We provide the first provisional checklist and detailed information on the distribution and diversity of all amphipod species from Switzerland. In total, we found 29 amphipod species. This includes 16 native and 13 non-native species, one of the latter (Orchestia cavimana) reported here for the first time for Switzerland. The diversity is compared to neighboring countries. We specifically discuss species of the genus Niphargus, which are often receiving less attention. We also found evidence of an even higher level of hidden diversity, and the potential occurrence of further cryptic species. This diversity reflects the biogeographic past of Switzerland, and suggests that amphipods are ideally suited to address questions on endemism and adaptive radiations, post-glaciation re-colonization and invasion dynamics as well as biodiversity-ecosystem functioning relationships in aquatic systems. PMID:25354099

  18. Nocturnal planktonic assemblages of amphipods vary due to the presence of coastal aquaculture cages.

    PubMed

    Fernandez-Gonzalez, V; Fernandez-Jover, D; Toledo-Guedes, K; Valero-Rodriguez, J M; Sanchez-Jerez, P

    2014-10-01

    Nocturnal pelagic swimming is common in the daily activity of peracarids in marine ecosystems. Fish farming facilities in coastal areas constitute an optimal artificial habitat for invertebrates such as amphipods, which can reach high abundance and biomass in fouling communities. Additionally, fish farms may modify the local oceanographic conditions and the distribution of pelagic communities. The aim of this study was to determine if nocturnal abundance and species composition of planktonic amphipod assemblages are affected by fish farm structures, using light traps as collecting method. A total of 809 amphipods belonging to 21 species were captured in farm areas, compared to 42 individuals and 11 species captured in control areas. The most important species contributing to the dissimilarity between farms and controls were the pelagic hyperiid Lestrigonus schizogeneios, the fouling inhabitants Ericthonius punctatus, Jassa marmorata, Stenothoe sp. and Caprella equilibra, and the soft-bottom gammarids Periculodes aequimanus and Urothoe pulchella. The great concentrations of planktonic amphipods at fish farm facilities is a result of the input of individuals from fouling communities attached to aquaculture facilities, along with the potential retention there of hyperiids normally present in the water column and migrant amphipods from soft sediments. Therefore, in addition to the effects of aquaculture on benthic communities, the presence of fish farms induces major changes in planktonic assemblages of invertebrates such as amphipods. PMID:25164018

  19. Comparative acute toxicity to aquatic organisms of components of coal-derived synthetic fuels. [Selenastrum capricornutum; Nitzchia palea; Physa gyrina, Daphnia magna; Chironomus tentans; Gammarus minus; Pimephales promelas; Salmo gairdneri; Micropterus salmoides

    SciTech Connect

    Millemann, R.E.; Birge, W.J.; Black, J.A.; Cushman, R.M.; Daniels, K.L.; Franco, P.J.; Giddings, J.M.; McCarthy, J.F.; Stewart, A.J.

    1984-01-01

    In acute toxicity tests, green algae Selenaastrum capricornutum, diatoms Nitzschia palea, adult snails Physa gyrina, juvenile cladocerans Daphnia magna, larval midges Chironomus tentans, adult amphipods Gammarus minus, juvenile fathead minnows Pimephales promelas, and embryo-larva stages of rainbow trout Salmo gairdneri and largemouth bass Micropterus salmoides were exposed for 4 hours (algae), 48 hours (arthropods and snails), 96 hours (fathead minnows), 7 days (large-mouth bass), and 27 days (rainbow trout) to two phenols (phenol and ..beta..-naphthol), two azaarenes (quinoline and acridine), and two polycyclic aromatic hydrocarbons (naphthalene and phenanthrene) present in coal-derived oils. Median lethal or median effective concentrations (LC50s or EC50s) ranged from 0.03 mg/liter for phenanthrene and rainbow trout to 286.54 mg/liter for phenol and the green alga. The rainbow trout embryo-larva assay was the most sensitive of the test systems to all the chemicals except quinoline. For this last compound, systems with juvenile fathead minnows and largemouth bass embryos were the most sensitive. As test systems, fish embryos and larvae were the most sensitive, juvenile fathead minnows and arthropods had intermediate sensitivity, and algae and snails were the most resistant to the test compounds under the test conditions. Within each chemical class (phenols, azaarenes, and polycylcic aromatic hydrocarbons), toxicity increased with increased ring number except for the reversed relationship with the azaarenes and fathead minnows. Thus, ..beta..-naphthol (two rings) was 2 to 45 times more toxic than phenol (one ring); acridine (three rings) was 7 to 27 times more toxic than quinoline (two rings); and phenanthrene (three rings) was 3 to 9 times more toxic than naphthalene (two rings). 50 references.

  20. Effects of water hardness, water temperature, and size of the test organism on the susceptibility of the freshwater shrimp, Gammarus pulex (L. ), to toxicants

    SciTech Connect

    Stephenson, R.R.

    1983-10-01

    In this study the authors examined the effects of water hardness, water temperature, size of test organism and duration of exposure on the acute toxicity of four substances to Gammarus pulex (L.), the freshwater shrimp.

  1. A comparison of the accumulation of phenanthrene by marine amphipods in water versus sediment

    SciTech Connect

    Fusi, T.; Weber, L.J.

    1995-12-31

    The objective of this research is to compare the accumulation of the polycyclic aromatic hydrocarbon phenanthrene by marine amphipods from sediment and interstitial water versus from a water only exposure system. The equilibrium partitioning theory assumes that the exposure and response of benthic invertebrates are the same when exposed to the same contaminant concentration in water and interstitial water. In this series of experiments, three infaunal marine amphipod species; Eohaustorius estuarius (non tube-forming, burrowing amphipod), Leptocheirus plumulosus (burrow-building amphipod) and Grandidierella japonica (tube-building amphipod), were exposed to {sup 14}C-phenanthrene under three experimental conditions: (1) sediment spiked at a concentration resulting in an interstitial water concentration of 2.5 {micro}g/l phenanthrene; (2) sediment spiked at a concentration resulting in interstitial water concentration of 2.5 {micro}g/l and the overlying water spiked at 2.5 {micro}g/l phenanthrene; (3) a water only exposure with the water at a concentration of 2.5 {micro}g/l phenanthrene, The exposures were conducted in a static renewal system with the overlying and exposure water being replaced every 8 hours. The bioaccumulation of phenanthrene was followed over 72 hours. In all three species of amphipods, the accumulation of phenanthrene was significantly greater in the water only exposure than in the two sediment exposures. At 72 hours, the amphipod body burdens of phenanthrene in the water only exposures were, depending on the species, 7 to 24 times that of the sediment only exposures. The results suggest that water only exposures may overestimate sediment or interstitial exposure to phenanthrene and other nonionic, lipophilic compounds.

  2. Postembryonic development of the parasitic amphipod Hyperia galba

    NASA Astrophysics Data System (ADS)

    Dittrich, Birgit

    1987-06-01

    Hyperia galba Montagu is associated with gelatinous zooplankton as are many species of the Hyperiidea. The hosts preferred in the European seas are the large scyphomedusae Aurelia aurita, Chrysaora hysoscella, Rhizostoma pulmo, Cyanea capillata and Cyanea lamarckii, which harbour the first developmental stages. The anamorphic development produces young that are incapable of swimming at the time of hatching. They are characterized by an embryonic abdomen without extremities and external segmentation; the eyes are not completely developed and the mouth is primitive lacking bristles, molar and incisor. The postembryonic development, described in detail, is subdivided into two phases: the pantochelis phase and the protopleon phase; the former comprises only one stage; the latter can be subdivided into four stages. In the course of postnatal development the larval organs are reduced and characters typical of the adult are gradually differentiated. H. galba plays an important role as obligatory endoparasite of scyphomedusae at least during the first stages of development; without a host this amphipod cannot survive, neither benthically nor in the plankton. The transition from life in the female's marsupium to endoparasitism in the jellyfish generally occurs during stage of the postembryonic development which is the first stage of the protopleon phase. The specific adaptations of its reproductive biology to a parasitic mode of life such as moult inhibition under starvation, development of larval organs and the behavioural patterns of the females as well as the young are described. Further, the influence of external factors such as temperature and food supply on the course of development is examined.

  3. Silver nanoparticles impact the functional role of Gammarus roeseli (Crustacea Amphipoda).

    PubMed

    Andreï, Jennifer; Pain-Devin, Sandrine; Felten, Vincent; Devin, Simon; Giambérini, Laure; Mehennaoui, Kahina; Cambier, Sebastien; Gutleb, Arno C; Guérold, François

    2016-01-01

    Silver nanoparticles (nAg) are widely used in consumer products and the risk associated with their potential release into freshwater ecosystems needs to be addressed using environmentally realistic exposure concentrations. Here, the effects of low concentrations (0.5-5 μg L(-1)) of two different sized nAg (10 and 60 nm) and a silver nitrate positive control were evaluated in Gammarus roeseli following exposure for 72 h. Cellular, individual and functional endpoints were independently studied and the most striking results were reported for functional endpoints. Indeed, without a change in their feeding activity, the gammarids produced significantly fewer fine particles of organic matter when exposed to nAg, even at 0.5 μg L(-1) of 10 nm nAg. These functional endpoints seem to be efficient markers for detecting the early effects of nAg on G. roeseli. PMID:26552543

  4. The Behavior Response of Amphipods Infected by Hedruris suttonae (Nematoda) and Pseudocorynosoma sp. (Acanthocephala).

    PubMed

    Casalins, Laura M; Brugni, Norma L; Rauque, Carlos A

    2015-12-01

    The manipulation of intermediate host behavior may increase chances of parasite transmission to the definitive host. In freshwater environments of the Neotropical Region, studies on behavioral manipulations by parasites are rare, and the majority of these consider only a single parasite species and/or 1 life stage of a particular parasite species. In Andean Patagonian lakes of Argentina, the amphipod Hyalella patagonica is infected by larvae of the fish nematode Hedruris suttonae and by the bird acanthocephalan Pseudocorynosoma sp. The 3 objectives of the present study were to determine whether H. suttonae and Pseudocorynosoma sp. differ in their effects on behavior of H. patagonica , whether such modification is associated with parasite development, and to assess the associations between behavioral traits. From naturally parasitized amphipods, activity (swimming levels) and phototaxis (light preference) was measured. Only in phototaxis trials did larvae of H. suttonae induce significantly higher levels of photophilia, suggesting that they are manipulative. Scores of activity and phototaxis were positive and significantly related for non-parasitized female amphipods and for amphipods parasitized by larvae of Pseudocorynosoma sp. but were not associated in amphipods parasitized with larvae of H. suttonae (infective and non-infective), suggesting that infection separated the relationship between these variables. PMID:26295566

  5. Microsporidian Parasites Found in the Hemolymph of Four Baikalian Endemic Amphipods

    PubMed Central

    Madyarova, Ekaterina V.; Adelshin, Renat V.; Dimova, Mariya D.; Axenov-Gribanov, Denis V.; Lubyaga, Yulia A.; Timofeyev, Maxim A.

    2015-01-01

    At present, approximately 187 genera and over 1300 species of Microsporidia have been described, among which almost half infect aquatic species and approximately 50 genera potentially infect aquatic arthropods. Lake Baikal is the deepest and one of the oldest lakes in the world, and it has a rich endemic fauna with a predominance of arthropods. Among the arthropods living in this lake, amphipods (Crustacea) are the most dominant group and are represented by more than 350 endemic species. Baikalian amphipods inhabit almost all depths and all types of substrates. The age and geographical isolation of this group creates excellent opportunities for studying the diversity, evolution and genetics of host-parasite relationships. However, despite more than 150 years of study, data investigating the microsporidia of Lake Baikal remain incomplete. In this study, we used molecular genetic analyses to detect microsporidia in the hemolymph of several endemic species of amphipods from Lake Baikal. We provide the first evidence that microsporidian species belonging to three genera (Microsporidium, Dictyocoela and Nosema) are present in the hemolymph of Baikalian endemic amphipods. In the hemolymph of Eulimnogammarus verrucosus, we detected SSU rDNA of microsporidia belonging to the genus Nozema. In the hemolymph of Pallasea cancellous, we found the DNA of Microsporidium sp. similar to that in other Baikalian endemic amphipods; Dictyocoela sp. was found in the hemolymph of Eulimnogammarus marituji and Acanthogammarus lappaceus longispinus. PMID:26087136

  6. Response of amphipod assemblages to desalination brine discharge: Impact and recovery

    NASA Astrophysics Data System (ADS)

    de-la-Ossa-Carretero, J. A.; Del-Pilar-Ruso, Y.; Loya-Fernández, A.; Ferrero-Vicente, L. M.; Marco-Méndez, C.; Martinez-Garcia, E.; Sánchez-Lizaso, J. L.

    2016-04-01

    Desalination has become an important industry whose dense, high-salinity effluent has an impact on marine communities. Without adequate dilution, brine remains on the bottom increasing bottom salinity and affecting benthic communities. Amphipods showed high sensitivity to increased salinity produced by desalination brine discharge. A decrease in abundance and diversity of amphipods was detected at the station closest to the outfall, where salinity values reached 53. This salinity was later reduced by including a diffuser at the end of the pipeline. Six months after diffuser installation, amphipod abundance increased. During the first stage of this recovery, species such as Photis longipes recovered their abundance, others such as Microdeutopus versiculatus displayed opportunistic patterns, while others needed more time for recovery, e.g. Harpinia pectinata. These differences may be dependent on the organism living habits.

  7. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (Pacific Southwest): Amphipods

    SciTech Connect

    Grosse, D.J.; Pauley, G.B.

    1989-01-01

    Species profiles are literature summaries of the taxonomy, morphology, distribution, life history, and environmental requirements of coastal aquatic species. They are prepared to assist in environmental impact assessment. Amphipods are ubiquitous in distribution, but are most abundant in estuarine areas and other high nutrient areas. Hyperiidea are the third most abundant coastal marine crustacean zooplankton, following copepods and euphausiids. Benthic Gammaridea are an invaluable food source for many economically important fish and invertebrate species. Habitat preference and behavior of the major amphipod groups is highly variable. Intertidal California amphipods overlap the distribution of common genera of other regions around the world. Amphipoda are reported to be indicators of heavily polluted areas. They are considered the most efficient of all scavengers on the sea bottom and in shoreline areas. 66 refs., 5 figs.

  8. Use of sublethal endpoints in sediment toxicity tests with the amphipod Hyalella azteca

    USGS Publications Warehouse

    Ingersoll, C.G.; Brunson, E.L.; Dwyer, F.J.; Hardesty, D.K.; Kemble, N.E.

    1998-01-01

    Short-term sediment toxicity tests that only measure effects on survival can be used to identify high levels of contamination but may not be able to identify marginally contaminated sediments. The objective of the present study was to develop a method for determining the potential sublethal effects of contaminants associated with sediment on the amphipod Hyalella azteca (e.g., reproduction). Exposures to sediment were started with 7- to 8-d-old amphipods. On day 28, amphipods were isolated from the sediment and placed in water-only chambers where reproduction was measured on day 35 and 42. Typically, amphipods were first in amplexus at about day 21 to 28 with release of the first brood between day 28 to 42. Endpoints measured included survival (day 28, 35, and 42), growth (as length and weight on day 28 and 42), and reproduction (number of young/female produced from day 28 to 42). This method was used to evaluate a formulated sediment and field-collected sediments with low to moderate concentrations of contaminants. Survival of amphipods in these sediments was typically >85% after the 28-d sediment exposures and the 14-d holding period in water to measure reproduction. Reproduction was more variable than growth; hence, more replicates might be needed to establish statistical differences among treatments. Previous studies have demonstrated that growth of H. azteca in sediment tests often provides unique information that can be used to discriminate toxic effects of exposure to contaminants. Either length or weight can be measured in sediment tests with H. azteca. However, additional statistical options are available if length is measured on individual amphipods, such as nested analysis of variance that can account for variance in length within replicates. Ongoing water-only studies testing select contaminants will provide additional data on the relative sensitivity and variability of sublethal endpoints in toxicity tests with H. azteca.

  9. Molecular phylogenetic evidence for the reorganization of the Hyperiid amphipods, a diverse group of pelagic crustaceans.

    PubMed

    Hurt, Carla; Haddock, Steven H D; Browne, William E

    2013-04-01

    Within the crustaceans, the Amphipoda rank as one of the most speciose extant orders. Amphipods have successfully invaded and become major constituents of a variety of ecosystems. The hyperiid amphipods are classically defined as an exclusively pelagic group broadly inhabiting oceanic midwater environments and often having close associations with gelatinous zooplankton. As with other amphipod groups they have largely been classified based on appendage structures, however evidence suggests that at least some of these characters are the product of convergent evolution. Here we present the first multi-locus molecular phylogenetic assessment of relationships among the hyperiid amphipods. We sampled 51 species belonging to 16 of the 23 recognized hyperiidian families for three nuclear loci (18S, 28S, and H3) and mitochondrial COI. We performed both Bayesian Inference and Maximum Likelihood analyses of concatenated sequences. In addition, we also explored the utility of species-tree methods for reconstructing deep evolutionary histories using the Minimize Deep Coalescence (MDC) approach. Our results are compared with previous molecular analyses and traditional systematic groupings. We discuss these results within the context of adaptations correlated with the pelagic life history of hyperiid amphipods. Within the infraorder Physocephalata (Bowman and Gruner, 1973) we inferred support for three reciprocally monophyletic clades; the Platysceloidea, Vibilioidea, and Phronimoidea. Our results also place the enigmatic Cystisomatidae and Paraphronimidae at the base of the infraorder Physosomata (Bowman and Gruner, 1973) suggesting that Physosomata as traditionally recognized is paraphyletic. Based on our multilocus phylogeny, major rearrangements to existing taxonomic groupings of hyperiid amphipods are warranted. PMID:23319084

  10. The Source of Bacteria Involved in the Break-Down of Gammarus Pulex Faecal Pellets Using Image Analysis

    NASA Astrophysics Data System (ADS)

    Joyce, P.; Wotton, R.

    2005-05-01

    Bacteria survive passage through the gut of aquatic animals and are implicated in the break-down of POM (such as faecal pellets) in aquatic systems. There is evidence that bacteria that survive gut passage are the cause of the initial break-down of faecal pellets, rather than colonisation by bacteria from the environment. Gammarus is the dominant shredder in lowland permeable catchments ("chalk streams") in England and feeds on allochthonous detritus such as fallen leaves. Gammarus faecal pellets could form important pathways for transfer of organic matter in chalk streams. We incubated Gammarus faecal pellets for 80 days in stream water using combinations of treatments (autoclaving the stream water or pellets; fresh non-autoclaved stream water or pellets; reducing bacterial activity using Gentamicin; combinations of these treatments) to assess the role of surviving and colonising bacteria on the break-down process. Break-down was measured using image analysis. Results show that treatments with fresh pellets show much higher levels of break-down than fully autoclaved controls, treatments with fresh stream water but autoclaved pellets, or treatments with Gentamicin. Bacteria surviving gut passage therefore seem to play a greater role in faecal pellet break-down than those colonising from the environment.

  11. [Determination of the parameters for producing a biobinder from wood: a mathematical modeling of the transformation of lignocellulose substrate by the fungus Panus tigrinus].

    PubMed

    Kondrashchenko, V I; Manukovskiĭ, N S; Kovalev, V S

    2006-01-01

    A biochemical scheme for the transformation of wood lignocellulose during enzymatic hydrolysis of polysaccharides and lignin destruction in reactions involving free radicals was developed, and a corresponding mathematical model was constructed. Processing (fermentation) of wood particles by the fungus Panus tigrinus in a submerged culture for producing a biobinder of wood composites--woodchip boards and fiber-boards--is considered. The mathematical model was used to study the technological parameters that influence the production of enzymes and fungal biomass and the level of free radical accumulation in the substrate, i.e., the factors determining the production of the biobinder. The optimal values of these parameters were determined, namely: the specific surface of wood particles, amounting to 2000 cm2/g; processing time of 56 h; and an initial concentration of 3.0 g/l of fungal biomass in the submerged culture. PMID:17168304

  12. INTERLABORATORY COMPARISON OF A REDUCED VOLUME MARINE SEDIMENT TOXICITY TEST METHOD USING AMPHIPOD AMPELISCA ABDITA

    EPA Science Inventory

    The U.S. Environmental Protection Agency has standardized methods for performing acute marine amphipod sediment toxicity tests. A test design reducing sediment volume from 200 to 50 ml and overlying water from 600 to 150 ml was recently proposed. An interlaboratory comparison wa...

  13. The occurrence of Echinorhynchus salmonis Müller, 1784 in benthic amphipods in the Baltic Sea.

    PubMed

    Benesh, Daniel P; Aura, Raija-Liisa; Andersin, Ann-Britt; Tellervo Valtonen, E

    2015-01-01

    The acanthocephalan Echinorhynchus salmonis Müller, 1784 is a common parasite of salmonid fish, but it has rarely been reported from an intermediate host. Samples of benthic amphipods, Monoporeia affinis (Lindström), were taken from multiple, deep sites (usually below 70 m) in the Gulf of Bothnia over the course of more than a decade and examined for acanthocephalans. Overall, only 0.44% of 23 296 amphipods were infected, all with just a single worm. This prevalence is consistent with several previous reports of acanthocephalans in deep-water, benthic amphipods, but it appears low compared to that often reported for acanthocephalan species infecting littoral amphipods. Parasite occurrence did not exhibit a clear regional pattern (i.e. northern vs southern sites) nor did it have any relationship with site depth. At sites sampled over multiple years, parasite abundance was consistently low (mostly < 0.01), though two spikes in abundance (over 0.06) were also observed, indicating that infection can be substantially higher at particular times or in particular places. The median density of E. salmonis in samples containing the parasite was estimated as 8.4 cystacanths per m(2). PMID:26373577

  14. REPRODUCTIVE TOXICITY OF CHLORPYRIFOS, DIELDRIN, AND METHYL MERCURY MIXTURES TO THE AMPHIPOD, HYALELLA AZTECA

    EPA Science Inventory

    Toxicological interactions were assessed on the reproduction of the amphipod Hyalella azteca throughout a chronic exposure to methyl mercury (0.9, 4.7, 23.3 nM), chlorpyrifos (0.01, 0.05, 0.24), dieldrin (0.5, 2.3, 11.4 nM) and their binary mixtures. H. azteca were exposed to the...

  15. Vertical zonation patterns of scavenging amphipods from the Hadal zone of the Tonga and Kermadec Trenches

    NASA Astrophysics Data System (ADS)

    Blankenship, Lesley E.; Yayanos, A. Aristides; Cadien, Donald B.; Levin, Lisa A.

    2006-01-01

    Deep-sea trenches present an ideal system in which to study vertical zonation, though the difficulties inherent in studying these great depths have thus far deterred such research. Here, we present the first account of the structure and vertical zonation of the scavenging guild residing in the hadal habitat of the Tonga and Kermadec Trenches (SW Pacific Ocean). Four species of scavenging amphipod ( Eurythenes gryllus, Scopelocheirus schellenbergi, Hirondellea dubia, and Uristes sp. nov.) were captured with baited free-vehicle traps set 1 m above the seafloor and deployed to bottom depths between 5155 and 10,787 m. Each species occupied a distinct vertical zone of 3.5 km or less, and the scavenging amphipod assemblage vertically partitioned the hadal zone. Scavenging amphipod diversity and evenness sharply declined below 9 km. For S. schellenbergi and H. dubia, population structure was stratified ontogenetically. Early instars appeared to reside exclusively in the shallower depths of each species' vertical zone, and were functionally missing from the median and deeper regions. We captured brooding Uristes sp. nov. females, documenting the first bait-attendance event of brooding amphipods in the hadal zone. Separation of habitat in conjunction with deviations in reproductive traits, behaviors, and nutritional strategies may facilitate the coexistence of these four related species in this harsh and confining habitat.

  16. Biochemical response of amphipods (Gammarid: Paramorea) in a sediment laboratory exposure from Ushuaia Bay, Beagle Channel.

    PubMed

    Schvezov, Natasha; Amin, Oscar

    2011-03-01

    A coastal system (Ushuaia Bay, Argentina) impacted by anthropogenic activities was studied by the response of local amphipods (Parmorea sp., Gammaridae) to the exposure of coastal sediments in a laboratory assay. Four coastal areas with different loadings of contaminants and one considered as reference were studied. Organic matter, carbohydrates, proteins and heavy metals were measured in sediment samples. Organisms were exposed to sediments for seven days and catalase (CAT), glutathione S-transferase (GST), acetylcholinesterase (AChE) and lipid peroxidation (LPO) were measured afterward. Amphipods exhibited an activation of GST and inhibition of AChE in most impacted areas. Principal Component Analysis (PCA) was conducted in order to associate the biological responses with sediment metal concentration and its eutrophicated status. Levels of Cd and Cr were associated with the inhibition of AChE and with the enhancement of GST. CAT and LPO were enhanced in most areas, but no link was found with the contaminants studied by PCA, suggesting that other parameters present in sediments not included in the PCA affect the amphipods. The most impacted area corresponds to Nautical Club station, with a highly eutrophicated status and high content of metals, where amphipods after the exposure were affected in a biochemical level. PMID:21239059

  17. POPTOX: Population-level responses of an amphipod to contaminated marine sediments and other environmental stresses

    SciTech Connect

    DeWitt, T.H.

    1994-12-31

    Experimental measurements of population-level responses are useful to environmental management in two ways: (1) to estimate the fitness of populations in an ecological-risk study, and (2) to evaluate the ecological relevance of shorter-term acute and chronic toxicity tests that use the same test species. An experimental system was developed for modeling the population-level responses of the burrowing, estuarine amphipod, Leptocheirus plumulosus, to environmental stresses, including chemical contamination. Replicate cohorts of newborn amphipods were exposed to natural and anthropogenic (PAH-contaminated sediment) stresses under static-renewal conditions over periods varying up to their full life-span. The amphipods were periodically removed from the sediment, censused, measured, and returned alive to the exposure chamber; the resulting life-history data were used to develop age-based, matrix-algebraic, population-projection models. Preliminary experiments revealed that an exposure period of 12 weeks with a sampling frequency of 2 weeks was sufficient to model the population dynamics of this amphipod. This experimental system may also be,used to study the interaction between anthropogenic stresses and ecological stresses under controlled and long-term exposures.

  18. BENTHIC AMPHIPOD COMMUNITY RESPONSE TO STRESS INDUCED BY ALGAL MATS IN A PACIFIC NORTHWEST ESTUARY

    EPA Science Inventory

    Amphipod, algal biomass and sediment samples were taken at two- to four-week intervals from June through December, 2000 along lines perpendicular to two transects in Yaquina Bay, OR, extending from within the Zostera marina bed at the river channel edge through intertidal burrowi...

  19. AMPHIPOD COMMUNITY RESPONSE TO STRESS INDUCED BY ALGAL MATS IN A PACIFIC NORTHWEST ESTUARY

    EPA Science Inventory

    Amphipod, algal and sediment samples were taken at two- to four-week intervals from June through December, 2000 along two transects in Yaquina Bay, OR. The transects extended from within the Zostera marina bed at the river channel edge through intertidal burrowing shrimp ...

  20. PRELIMINARY CULTURE AND LIFE-CYCLE EXPERIMENTS WITH THE BENTHIC AMPHIPOD AMPELISCA ABDITA

    EPA Science Inventory

    The tube-dwelling amphipod Ampelisca abdita Mills 1964 has been used extensively in acute sediment toxicity tests and has been shown to be amenable to chronic testing. mpelisca abdita was held in the lab through several generations when fed algal food in daily static renewals, al...

  1. A field assessment of long-term laboratory sediment toxicity tests with the amphipod Hyalella azteca

    USGS Publications Warehouse

    Ingersoll, C.G.; Wang, N.; Hayward, J.M.R.; Jones, J.R.; Jones, S.B.; Ireland, D.S.

    2005-01-01

    Response of the amphipod Hyalella azteca exposed to contaminated sediments for 10 to 42 d in laboratory toxicity tests was compared to responses observed in controlled three-month invertebrate colonization exposures conducted in a pond. Sediments evaluated included a sediment spiked with dichlorodiphenyldichloroethane (DDD) or dilutions of a field sediment collected from the Grand Calumet River (GCR) in Indiana (USA) (contaminated with organic compounds and metals). Consistent effects were observed at the highest exposure concentrations (400 ??g DDD/goc [DDD concentrations normalized to grams of organic carbon (goc) in sedimentl or 4% GCR sediment) on survival, length, and reproduction of amphipods in the laboratory and on abundance of invertebrates colonizing sediments in the field. Effect concentrations for DDD observed for 10-d length and 42-d reproduction of amphipods (e.g., chronic value [ChV] of 66 ??g DDD/goc and 25% inhibition concentration [IC25] of 68 ??g DDD/goc for reproduction) were similar to the lowest effect concentrations for DDD measured on invertebrates colonizing sediment the field. Effect concentrations for GCR sediment on 28-d survival and length and 42-d reproduction and length of amphipods (i.e., ChVs of 0.20-0.66% GCR sediment) provided more conservative effect concentrations compared to 10-d survival or length of amphipods in the laboratory or the response of invertebrates colonizing sediment in the field (e.g., ChVs of 2.2% GCR sediment). Results of this study indicate that use of chronic laboratory toxicity tests with H. azteca and benthic colonization studies should be used to provide conservative estimates of impacts on benthic communities exposed to contaminated sediments. Bioaccumulation of DDD by oligochaetes colonizing the DDD-spiked sediment was similar to results of laboratory sediment tests previously conducted with the oligochaete Lumbriculus variegates, confirming that laboratory exposures can be used to estimate

  2. Community composition of scavenging amphipods at bathyal depths on the Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Horton, Tammy; Thurston, Michael H.; Duffy, Grant A.

    2013-12-01

    This study focussed on a section of the Mid-Atlantic Ridge with one pair of sampling areas at 49°N and the other at 54°N, north and south of the Charlie-Gibbs Fracture Zone and east and west of the ridge, at a water depth of 2500 m. Sixteen baited-trap samples of necrophagous amphipods were collected during three research cruises on the R.R.S. James Cook in 2007, 2009 and 2010. Amphipods of the superfamily Lysianassoidea are numerically dominant and taxonomically diverse and form the most important group of necrophages in most deep-sea environments. A total of 39 scavenging species from 253,306 specimens were identified at the four sampling areas over the 4-year study period. Less than half of the entities could be ascribed to known species. More than 25% of the species recorded were found at all of the sampling areas, supporting the view that necrophagous amphipods are widely distributed animals. The number of lysianassoid species (31) was higher than expected when compared with other studies of necrophagous amphipods, particularly as all sampling was done at one depth (2500 m). Deep-sea scavenging amphipods are generally thought to have low diversity and previous studies have supported this view. Sample sizes were large with some traps containing more than 40,000 specimens. The most abundant species, Abyssorchomene abyssorum, dominated all trap samples with percentage compositions over 90% at the NE sites in 2009-2010. Univariate and Multivariate analyses indicated a significant difference in community composition and species richness between the northern and southern stations. There are at least 15 new species to be described from these samples, and particular effort is required in the genus Paracallisoma and the genus Tryphosella.

  3. Enrichment of uranium in particulate matter during litter decomposition affected by Gammarus pulex L.

    PubMed

    Schaller, Jörg; Weiske, Arndt; Mkandawire, Martin; Dudel, E Gert

    2008-12-01

    Plant litter and organic matter of aquatic sediments provide a significant sink of soluble inorganic uranium species in contaminated ecosystems. The uranium content in detritus has been observed to increase significantly during decomposition. However, the influence of the decomposer community on uranium fixation remains unclear. In view of this, we investigated the influence of a shredder (the freshwater shrimp Gammarus pulex L) on uranium fixation and mobilization during the degradation of plant litter. Leaf litter from Alnus glutinosa (L.) Gaertn. with 1152 mg kg(-1) U of dry biomass (DM) and without uranium was used in a 14-day laboratory experiment. The uranium concentration in the particulate organic material (POM) at the end of experiment was 1427 mg kg(-1) DM. After 14 days of decay, the residues of the leaves show a uranium concentration of 644 mg kg(-1) DM. Uranium concentrations in the media initially increased reaching up to 63.9 microg L(-1) but finally decreased to an average value of 34.3 microg L(-1). Atthe same time, DOC levels increased from 2.43 mg L(-1) up to 11.4 mg L(-1) in the course of the experiment Hence, inorganic uranium fixation onto particulate organic matter was enhanced by the activity of G. pulex. PMID:19192788

  4. Microbial proliferation on gill structures of juvenile European lobster ( Homarus gammarus) during a moult cycle

    NASA Astrophysics Data System (ADS)

    Middlemiss, Karen L.; Urbina, Mauricio A.; Wilson, Rod W.

    2015-12-01

    The morphology of gill-cleaning structures is not well described in European lobster ( Homarus gammarus). Furthermore, the magnitude and time scale of microbial proliferation on gill structures is unknown to date. Scanning electron microscopy was used to investigate development of setae in zoea, megalopa and juvenile stages (I-V). Microbes were classified and quantified on gill structures throughout a moult cycle from megalopa (stage IV) to juvenile (stage V). Epipodial serrulate setae, consisting of a naked proximal setal shaft with the distal portion possessing scale-like outgrowths (setules), occur only after zoea stage III. After moulting to megalopa (stage IV), gill structures were completely clean and no microbes were visible on days 1 or 5 postmoult. Microbial proliferation was first evident on day 10 postmoult, with a significant 16-fold increase from day 10 to 15. Rod-shaped bacteria were initially predominant (by day 10); however, by day 15 the microbial community was dominated by cocci-shaped bacteria. This research provides new insights into the morphology of gill-grooming structures, the timing of their development, and the magnitude, timescale and characteristics of gill microbial proliferation during a moult cycle. To some degree, the exponential growth of epibionts on gills found during a moult cycle will likely impair respiratory (gas exchange) and ion regulatory function, yet further research is needed to evaluate the physiological effects of the exponential bacterial proliferation documented here.

  5. How Biotransformation Influences Toxicokinetics of Azole Fungicides in the Aquatic Invertebrate Gammarus pulex.

    PubMed

    Rösch, Andrea; Anliker, Sabine; Hollender, Juliane

    2016-07-01

    Biotransformation is a key process that can greatly influence the bioaccumulation potential and toxicity of organic compounds. In this study, biotransformation of seven frequently used azole fungicides (triazoles: cyproconazole, epoxiconazole, fluconazole, propiconazole, tebuconazole and imidazoles: ketoconazole, prochloraz) was investigated in the aquatic invertebrate Gammarus pulex in a 24 h exposure experiment. Additionally, temporal trends of the whole body internal concentrations of epoxiconazole, prochloraz, and their respective biotransformation products (BTPs) were studied to gain insight into toxicokinetic processes such as uptake, elimination and biotransformation. By the use of high resolution tandem mass spectrometry in total 37 BTPs were identified. Between one (ketoconazole) and six (epoxiconazole) BTPs were identified per parent compound except for prochloraz, which showed extensive biotransformation reactions with 18 BTPs detected that were mainly formed through ring cleavage or ring loss. In general, most BTPs were formed by oxidation and conjugation reactions. Ring loss or ring cleavage was only observed for the imidazoles as expected from the general mechanism of oxidative ring openings of imidazoles, likely affecting the bioactivity of these BTPs. Overall, internal concentrations of BTPs were up to 3 orders of magnitude lower than that of the corresponding parent compound. Thus, biotransformation did not dominate toxicokinetics and only played a minor role in elimination of the respective parent compound, with the exception of prochloraz. PMID:27232586

  6. Suspension feeding in adult Nephrops norvegicus (L.) and Homarus gammarus (L.) (decapoda)

    NASA Astrophysics Data System (ADS)

    Loo, Lars-Ove; Pihl Baden, Susanne; Ulmestrand, Mats

    Suspension feeding in adults of the Norway lobster Nephrops norvegicus (40-74 g) and the European lobster Homarus gammarus (280-350 g) was tested in experiments offering planktonic food items of different sizes from 200 to 600 μm and measuring the clearing capacity. Both lobster species were found to effectively clear water of food particles comprising nauplii of the brine shrimp Artemia salina of about 600 μm in size. These were reduced to 50% of the initial concentration within 5 h and to 90% within 12 h. When N. norvegicus was offered food particles averaging 200 μm, a significant reduction in average size occurred, indicating that the minimum retention size is around 200 μm. Fluorescently dyed Artemia salina were recovered in the stomach and intestine of lobsters proving that the filtered particles are passed to the digestive tract. Results from other experiments, using the blood pigment (haemocyanin) concentration as an index of nutritional state, indicated that the lobsters can get some nutritional advantage from suspension feeding. Suspension feeding in larger decapods has not been described previously, so the significance of this finding is discussed with respect to changes in behavioural and ecological role.

  7. Ingestion and Adsorption of Bacillus thuringiensis subsp. israelensis by Gammarus lacustris in the Laboratory

    PubMed Central

    Brazner, John C.; Anderson, Richard L.

    1986-01-01

    Several groups of Gammarus lacustris adults were exposed to solutions containing 0.5 and 5.0 mg of Bacillus thuringiensis subsp. israelensis per liter for 1- or 24-h periods by using traditional static bioassay exposure procedures. During a postexposure holding period, fecal pellets were removed and plated on tryptic soy agar to determine B. thuringiensis subsp. israelensis spore content. The experiments verified that traditional exposure procedures assure ingestion of B. thuringiensis subsp. israelensis spores and provided a mean dose estimate of 1,948 spores ingested per test animal with a 95% confidence interval ranging from 891 to 4,296 (1-h exposure, 5.0 mg/liter). It was also found that dose level is highly dependent upon both exposure duration and concentration and that relatively short exposures can result in a relatively long-term retention of spores postexposure (≥30 days). Body burden experiments established that large numbers of spores adsorb to the bodies of test animals during exposure and may in part explain the long-term retention of spores in the test system postexposure. These results imply that in field applications of microbial control agents, toxicologically unaffected but exposed organisms might transport the agent to untreated sites, expanding the effective treatment area and the number of organisms exposed. PMID:16347242

  8. Polymorphus minutus affects antitoxic responses of Gammarus roeseli exposed to cadmium.

    PubMed

    Gismondi, Eric; Beisel, Jean-Nicolas; Cossu-Leguille, Carole

    2012-01-01

    The acanthocephalan parasite Polymorphus minutus is a manipulator of its intermediate host Gammarus roeseli, which favours its transmission to the final host, a water bird. In contaminated environments, G. roeseli have to cope with two stresses, i.e. P. minutus infection and pollutants. As P. minutus survival relies on its host's survival, we investigated the influence of P. minutus on the antitoxic defence capacities and the energy reserves of G. roeseli females after cadmium exposure. In parallel, malondialdehyde, a toxic effect biomarker, was measured in G. roeseli females and in P. minutus. The results revealed that infected females displayed higher cell damage than uninfected ones, despite an apparent increase in reduced glutathione and metallothionein production. In fact, the increase of these antitoxic systems could be counterbalanced by carotenoid intake by the parasite, so that the overall defence system seemed less efficient in infected females than in uninfected ones. In addition, we demonstrated that cadmium induced cell damage in P. minutus, probably linked with cadmium accumulation in the parasite. Altogether, we observed a paradoxical pattern of responses suggesting that P. minutus increases cadmium toxicity in G. roeseli females although (i) it tends to increase several host antitoxic defence capacities and (ii) it bears part of the pollutant, as reflected by cell damage in the parasite. PMID:22911795

  9. Seasonal variability of antioxidant biomarkers and energy reserves in the freshwater gammarid Gammarus roeseli.

    PubMed

    Sroda, Sophie; Cossu-Leguille, Carole

    2011-04-01

    In gammarids, behavioural and biochemical biomarkers are commonly used in ecotoxicological studies. In our study, we have investigated seasonal variations of several biochemical biomarkers in Gammarus roeseli, a freshwater species. Organisms were sampled monthly over a 1-year period. Gender was distinguished to measure antioxidant enzyme activities like total glutathione peroxidase (GPxtot), selenium-dependent glutathione peroxidase (SeGPx) and catalase enzymes, lipoperoxidation end-product (malondialdehyde, MDA), and energy reserves with protein and lipid contents. In the same time, usual water physico-chemical parameters were measured at the sampling site. A based-gender difference was observed for parameters related to oxidative stress. Females showed higher antioxidant enzyme activities and lower MDA level than males. Parameters related to oxidative stress and energy reserves appeared correlated with temperature and physiological status of organisms. Females GPx activities were lower in autumn and winter when no breeding occurred. In both gender, MDA levels were correlated with temperature with an increase of lipoperoxidation in summer. Lipid contents were the lowest in summer and the highest in winter, probably due to the reproductive status of organisms and their feeding behaviour. Gender-based differences of biochemical parameters suggest a specific sensitivity of males and females in ecotoxicological experiments. Moreover, organisms could be more vulnerable in summer when MDA levels are high and energy reserves low. Deleterious effect of xenobiotics would be different with gender and season. PMID:21215985

  10. Polymorphus Minutus Affects Antitoxic Responses of Gammarus Roeseli Exposed to Cadmium

    PubMed Central

    Gismondi, Eric; Beisel, Jean-Nicolas; Cossu-Leguille, Carole

    2012-01-01

    The acanthocephalan parasite Polymorphus minutus is a manipulator of its intermediate host Gammarus roeseli, which favours its transmission to the final host, a water bird. In contaminated environments, G. roeseli have to cope with two stresses, i.e. P. minutus infection and pollutants. As P. minutus survival relies on its host's survival, we investigated the influence of P. minutus on the antitoxic defence capacities and the energy reserves of G. roeseli females after cadmium exposure. In parallel, malondialdehyde, a toxic effect biomarker, was measured in G. roeseli females and in P. minutus. The results revealed that infected females displayed higher cell damage than uninfected ones, despite an apparent increase in reduced glutathione and metallothionein production. In fact, the increase of these antitoxic systems could be counterbalanced by carotenoid intake by the parasite, so that the overall defence system seemed less efficient in infected females than in uninfected ones. In addition, we demonstrated that cadmium induced cell damage in P. minutus, probably linked with cadmium accumulation in the parasite. Altogether, we observed a paradoxical pattern of responses suggesting that P. minutus increases cadmium toxicity in G. roeseli females although (i) it tends to increase several host antitoxic defence capacities and (ii) it bears part of the pollutant, as reflected by cell damage in the parasite. PMID:22911795

  11. The toxicological effects of thiamethoxam on Gammarus kischineffensis (Schellenberg 1937) (Crustacea: Amphipoda).

    PubMed

    Uğurlu, Pelin; Ünlü, Erhan; Satar, Elif İpek

    2015-03-01

    Neonicotinoids are a new group of insecticides, and little is known about their toxicity to nontarget freshwater organisms an potential effects on freshwater ecosystems. The aim of this study is to establish the acute toxicity and histopathological effects of thiamethoxam-based pesticide on the gill tissue of Gammarus kischineffensis. In this study G. kischineffensis samples were exposed to 2.5, 5, 7.5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90 and 100mg/l of commercial grade thiamethoxam for 96 h. The 24, 48, 72 and 96 h LC50 values were determined as 75.619, 23.505, 8.048 and 3.751 mg/l respectively. In histopathological study the individuals were exposed to 0.004, 0.04 and 0.4 mg/l thiamethoxam concentrations for 14 days. The results showed that the most common changes at all doses of thiamethoxam were vacuolization and hemostatic infiltration in the gill tissue of G. kischineffensis. PMID:25710849

  12. Effects of light pollution on the emergent fauna of shallow marine ecosystems: Amphipods as a case study.

    PubMed

    Navarro-Barranco, Carlos; Hughes, Lauren Elizabeth

    2015-05-15

    Light pollution from coastal urban development is a widespread and increasing threat to biodiversity. Many amphipod species migrate between the benthos and the pelagic environment and light seems is a main ecological factor which regulates migration. We explore the effect of artificial lighting on amphipod assemblages using two kind of lights, LED and halogen, and control traps in shallow waters of the Great Barrier Reef. Both types of artificial light traps showed a significantly higher abundance of individuals for all species in comparison to control traps. LED lights showed a stronger effect over the amphipod assemblages, with these traps collecting a higher number of individuals and differing species composition, with some species showing a specific attraction to LED light. As emergent amphipods are a key ecological group in the shallow water environment, the impact of artificial light can affect the broader functioning of the ecosystem. PMID:25817311

  13. Relationships among levels of benthic vegetation and pore-water sulfides, burrowing shrimp and infaunal amphipods in Yaquina estuary, Oregon

    EPA Science Inventory

    Benthic amphipods are an important component of estuarine food webs, which in turn support ecological services provided by near shore commercial and recreational fisheries. In this study relationships among biological and geochemical aspects of the intertidal community were inve...

  14. Electrophoretic approach to the biochemical systematics of gammarids

    NASA Astrophysics Data System (ADS)

    Bulnheim, H.-P.; Scholl, A.

    1981-12-01

    By utilizing the techniques for electrophoretic separation of proteins by vertical starch gels, the biochemical systematics of 10 Gammaridae species obtained from marine, brackish and freshwater habitats was studied. They included Chaetogammarus marinus, Gammarus zaddachi, G. salinus, G. oceanicus, G. tigrinus, G. chevreuxi, G. locusta, G. duebeni duebeni, G. d. celticus, G. pulex pulex, and G. fossarum. For comparison of electrophoretic mobilities selected enzymes (phosphoglucose isomerase, glutamate oxalacetate transaminase, arginine phosphokinase, hexokinase, leucine amino peptidase, mannose 6-phosphate isomerase) were assayed. They were used as diagnostic characters in terms of electrophoretic identities or diversities of most frequent alleles at polymorphic gene loci. These criteria could be applied to estimate intrageneric enzymic variation and degrees of genetic relatedness between the crustacean amphipod species under consideration, thereby complementing traditional morphological classification.

  15. Acute toxicity and biochemical effects of azinphos methyl in the amphipod Hyalella curvispina.

    PubMed

    Anguiano, Olga Liliana; Castro, Claudia; Venturino, Andrés; Ferrari, Ana

    2014-09-01

    We evaluated the acute toxicity and biochemical effects of the organophosphorus pesticide azinphos methyl (AM) in the amphipod Hyalella curvispina that inhabits ponds and irrigation channels of an intensive fruit-producing region in Rio Negro and Neuquén valley, North Patagonia, Argentina. The analysis by nonlinear regression of data from the 96 h-acute toxicity tests indicated the coexistence of two subpopulations of H. curvispina with different susceptibilities to AM. The 96 h-LC₅₀ for the resistant subpopulation (166 ± 56 μg/L) was 216-fold higher than the 96h-LC₅₀ value for the susceptible one (0.77 ± 1.33 μg/L).The two subpopulations could not be distinguished based on the biochemical measurements in control amphipods. Cholinesterase activity was significantly inhibited in AM-exposed amphipods in a concentration-dependent manner. The IC₅₀ value obtained after 96 h of exposure (2.18 ± 1.95 μg/L) was significantly lower than the 48 h-IC₅₀ value (29.6 ± 17.4 μg/L). Carboxylesterase activity was significantly inhibited after 48 h of exposure to 12.5 and 62.5 μg/L AM (inhibition, 51%). This enzyme was thus able to protect cholinesterase from inhibition at 12.5 μg/L AM. Reduced glutathione and catalase showed a significant increase after 24 h of exposure as an adaptive response to AM, whereas glutathione S-transferase activity was not significantly modified. The analysis of species sensitivity distribution showed that both subpopulations of H. curvispina were more tolerant to AM than most amphipod species, and that the susceptible subpopulation was more sensitive to AM than the other local aquatic species analyzed. The maximum concentration of AM in drainage water within the fruit-producing area reported by other studies would affect most of the amphipod species (99%) and also a 44% of local aquatic ones. The results obtained in this study point out the usefulness of including amphipods like H. curvispina in ecotoxicity studies and

  16. Targeted metabolomics of Gammarus pulex following controlled exposures to selected pharmaceuticals in water.

    PubMed

    Gómez-Canela, Cristian; Miller, Thomas H; Bury, Nicolas R; Tauler, Romà; Barron, Leon P

    2016-08-15

    The effects of pharmaceuticals and personal care products (PPCPs) on aquatic organisms represent a significant current concern. Herein, a targeted metabolomics approach using liquid chromatography-high resolution mass spectrometry (LC-HRMS) is presented to characterise concentration changes in 29 selected metabolites following exposures of aquatic invertebrates, Gammarus pulex, to pharmaceuticals. Method performance revealed excellent linearity (R(2)>0.99), precision (0.1-19%) and lower instrumental limits of detection (0.002-0.20ng) for all metabolites studied. Three pharmaceuticals were selected representing the low, middle and high range of measured acute measured toxicities (of a total of 26 compounds). Gammarids were exposed to both the no-observed-adverse-effect-level (NOAEL) and the lowest-observed-adverse-effect-level (LOAEL) of triclosan (0.1 and 0.3mgL(-1)), nimesulide (0.5 and 1.4mgL(-1)) and propranolol (100 and 153mgL(-1)) over 24h. Quantitative metabolite profiling was then performed. Significant changes in metabolite concentrations relative to controls are presented and display distinct clustered trends for each pharmaceutical. Approximately 37% (triclosan), 33% (nimesulide) and 46% (propranolol) of metabolites showed statistically significant time-related effects. Observed changes are also discussed with respect to internal concentrations of the three pharmaceuticals measured using a method based on pulverised liquid extraction, solid phase extraction and LC-MS/MS. Potential metabolic pathways that may be affected by such exposures are also discussed. This represents the first study focussing on quantitative, targeted metabolomics of this lower trophic level benthic invertebrate that may elucidate biomarkers for future risk assessment. PMID:27110989

  17. Acute toxicity of cadmium to eight species of marine amphipod and isopod crustaceans from southern California

    SciTech Connect

    Hong, J.S.; Reish, D.J.

    1987-11-01

    Amphipods and isopods are important components of the marine intertidal and subtidal fauna where they are found on or in the substrate or among spaces between larger, attached organisms. However, in spite of their abundance and importance, the use of these two endemic marine groups has been limited in comparison to decapods in marine toxicological research. The purpose of this study was to investigate the effect of a single metallic salt, CdCl/sub 2/, on six species of amphipods and two species of isopods under similar experimental conditions. Cadmium was selected as the toxicant in this comparative study since this metal is an important constituent in municipal wastes discharged into southern California marine waters.

  18. Acoustic and in situ measurements of freshwater amphipods (Jesogammarus annandalei) in Lake Biwa, Japan

    SciTech Connect

    Trevorrow, M.V.; Tanaka, Yuji

    1997-01-01

    During a 23-d study of Lake Biwa, Japan (starting 23 August 1993), multifrequency inverted echo-sounder measurements of nocturnal scattering layers in the meta- and epilimnion were performed at a single location. Direct samples from within this scattering layer indicated that it was composed of Jesogammarus annandalei (Crustacea:Amphipoda), with mean adult length of 8.3 mm and population densities from 4 to 50 per m{sup 3}. Estimates of the scattering cross-section for individual amphipods were extracted from echo-amplitude probability distributions combined with volume scattering strength from a 198-kHz sonar. Total scattering cross-sections for adult amphipods at 88, 118, and 198 kHz were estimated as 4.3{plus_minus}0.9 x 10{sup {minus}8} m{sup 2}, 8.7{plus_minus}1.2 x 10{sup {minus}8} m{sup 2}, and 2.8{plus_minus}0.5 x 10{sup {minus}7} m{sup 2}. These cross-section measurements were found to be consistent with a fluid cylinder acoustic scattering model with a 1.2-mm radius and a 9.6-mm length. The acoustically derived population densities, sizes, and length-to-radius ratio were consistent with in situ amphipod samples. The amphipods exhibited a clear nocturnal migration into the lower thermocline, concentrating at depths of 15-25 m beginning after sunset (near 1830 hours local time) each day. Population densities (10-min averaged) showed maxima of 10-30 per m{sup 3} near 2000 hours, with densities decreasing rapidly toward midnight and disappearing by approximately 0430 hours. 23 refs., 11 figs., 2 tabs.

  19. Light triggers habitat choice of eyeless subterranean but not of eyed surface amphipods.

    PubMed

    Fišer, Žiga; Novak, Luka; Luštrik, Roman; Fišer, Cene

    2016-02-01

    Boundaries of species distributions are the result of colonization-extinction processes. Survival on the boundary depends on how well individuals discriminate optimal from suboptimal habitat patches. Such behaviour is called habitat choice and was only rarely applied to macroecology, although it links species ecological niche and species distribution. Surface and subterranean aquatic species are spatially strongly segregated, even in the absence of physical barriers. We explored whether a behavioural response to light functions as a habitat choice mechanism that could explain species turnover between surface and subterranean aquatic ecosystems. In a controlled laboratory experiment, we studied the behavioural response to light of ten pairs of surface and subterranean amphipods that permanently co-occur in springs. Surface species showed a weak photophobic, photoneutral, and in one case, photophilic response, whereas all subterranean species showed a strong photophobic response. Eyeless subterranean but not eyed surface amphipods appear to orient themselves with light cues. On a local scale, this difference possibly diminishes harmful interactions between the co-occurring amphipods, whereas on a regional scale, photophobia could explain limited dispersal and a high degree of endemism observed among subterranean species. PMID:26757929

  20. Assimilation of polybrominated diphenyl ethers from microplastics by the marine amphipod, Allorchestes compressa.

    PubMed

    Chua, Evan M; Shimeta, Jeff; Nugegoda, Dayanthi; Morrison, Paul D; Clarke, Bradley O

    2014-07-15

    Microplastic particles (MPPs; <5 mm) are found in skin cleansing soaps and are released into the environment via the sewage system. MPPs in the environment can sorb persistent organic pollutants (POPs) that can potentially be assimilated by organisms mistaking MPPs for food. Amphipods (Allorchestes compressa) exposed to MPPs isolated from a commercial facial cleansing soap ingested ≤45 particles per animal and evacuated them within 36 h. Amphipods were exposed to polybrominated diphenyl ether (PBDEs) congeners (BDE-28, -47, -99, -100, -153, -154, and -183) in the presence or absence of MPPs. This study has demonstrated that PBDEs derived from MPPs can be assimilated into the tissue of a marine amphipod. MPPs reduced PBDE uptake compared to controls, but they caused greater proportional uptake of higher-brominated congeners such as BDE-154 and -153 compared to BDE-28 and -47. While MPPs in the environment may lower PBDE uptake compared to unabsorbed free chemicals, our study has demonstrated they can transfer PBDEs into a marine organism. Therefore, MPPs pose a risk of contaminating aquatic food chains with the potential for increasing public exposure through dietary sources. This study has demonstrated that MPPs can act as a vector for the assimilation of POPs into marine organisms. PMID:24884099

  1. Use of sublethal endpoints in sediment toxicity testing with the amphipod Hyalella azteca

    SciTech Connect

    Kemble, N.E.; Brunson, E.B.; Dwyer, F.J.; Ehrhardt, E.A.; Hardesty, D.K.; Haverland, P.S.; Ingersoll, C.G.

    1995-12-31

    ASTM and EPA standard methods for sediment toxicity tests with Hyalella azteca typically recommend use of lethality as the endpoint in a 10-d exposure. However, data from 10- to 28-d exposures with amphipods indicate sublethal endpoints (i.e., growth, sexual maturation, or reproduction) identify additional samples as toxic. The authors compared the frequency that lethal and sublethal endpoints identified a sediment sample as toxic in 14- and 28-d amphipod exposures. In the 14-d amphipod exposures, lethality identified 20% of the samples as toxic, and sublethal endpoints identified an additional 16% of the samples as toxic using sublethal endpoints only. Similarly, in the 28-d exposures, lethality identified 14% of the samples as toxic and sublethal endpoints identified an additional 18% of the samples as toxic. The authors are also currently evaluating Sediment Effect Concentrations (SECs) relative to both lethal and sublethal endpoints in H. azteca exposures. These SECs will be used to evaluate reliability in estimating toxicity of samples. Potential factors which may confound interpretation of sublethal endpoints in sediment tests include: (1) changes in sediment chemistry resulting from long-term storage or feeding (2) the influence of physical characteristics of sediment (grain size), and (3) effects of ammonia or hydrogen sulfide.

  2. Phylogenetic relationships among hadal amphipods of the Superfamily Lysianassoidea: Implications for taxonomy and biogeography

    NASA Astrophysics Data System (ADS)

    Ritchie, H.; Jamieson, A. J.; Piertney, S. B.

    2015-11-01

    Amphipods of the superfamily Lysianassoidea are ubiquitous at hadal depths (>6000 m) and therefore are an ideal model group for investigating levels of endemism and the drivers of speciation in deep ocean trenches. The taxonomic classification of hadal amphipods is typically based on conventional morphological traits but it has been suggested that convergent evolution, phenotypic plasticity, intra-specific variability and ontogenetic variation may obscure the ability to robustly diagnose taxa and define species. Here we use phylogenetic analysis of DNA sequence variation at two mitochondrial (COI and 16S rDNA) and one nuclear (18S rDNA) regions at to examine the evolutionary relationships among 25 putative amphipod species representing 14 genera and 11 families that were sampled from across seven hadal trenches. We identify several instances where species, genera and families do not resolve monophyletic clades, highlighting incongruence between the current taxonomic classification and the molecular phylogeny for this group. Our data also help extend and resolve the known biogeographic distributions for the different species, such as identifying the co-occurrence of Hirondellea dubia and Hirondellea gigas in the Mariana trench.

  3. Effect of salinity on the toxicity of road dust in an estuarine amphipod Grandidierella japonica.

    PubMed

    Hiki, Kyoshiro; Nakajima, Fumiyuki

    2015-01-01

    Urban runoff can reach coastal aquatic environments; however, little is known about the effect of salinity on road runoff toxicity. The objective of this study is to investigate the toxicity of highway road dust over a salinity gradient from 5 to 35‰, in an estuarine benthic amphipod, Grandidierella japonica. Road dust toxicity was evaluated by assessing mortality after 10 days of exposure and short-term microbead ingestion activity of the amphipod. For all road dust samples considered, amphipod mortality increased with increasing salinity, whereas no significant difference in mortality was observed among test salinities in the reference river sediment. Ingestion activity during exposure to road dust decreased with increasing salinity. In fact, none of the individuals ingested any microbeads at salinity of 35‰. If assumed microbead ingestion is a proxy for feeding activity, high mortality at 35‰ could be attributed to aquatic exposure and not to dietary exposure. These findings suggest that road dust may have considerable impact on benthic organisms at high salinity levels. PMID:26360764

  4. Benthimermithid nematode parasites of the amphipod Hirondellea dubia in the Kermadec Trench.

    PubMed

    Leduc, Daniel; Wilson, James

    2016-04-01

    Parasitic nematodes have evolved to exploit a wide variety of hosts living in a range of marine environments. Benthimermithid nematodes occur deeper than any other nematode parasites (down to 5880 m depth) but are mostly known from free-living adult stages living in the sediments, and parasitic juveniles are seldom encountered. In the present study, the benthimermithid Trophomera cf. marionensis was discovered in the body cavity of the lysianassoid amphipod Hirondellea dubia sampled between 7018 and 10,005 m depths in the Kermadec Trench. The nematode specimens, which could be readily observed through the transparent exoskeleton of freshly caught amphipods, were up to twice the length of T. marionensis specimens described from the Atlantic and East Pacific Oceans but were otherwise morphologically identical. Because of its wide geographical and water depth distribution (almost 10,000 m), T. marionensis likely consists of several cryptic species. The prevalence of Trophomera parasites among the host population was estimated to be substantially less than 1 %; such a low proportion of parasitised hosts could help explain why so few Trophomera specimens have been obtained from their host so far. The present study demonstrates that parasites can occur throughout the entire ocean depth and that they likely occur in other hadal trenches where H. dubia and other lysianassoid amphipods also dominate. PMID:26779924

  5. A preliminary study of the Caprella scaura amphipod culture for potential use in aquaculture

    NASA Astrophysics Data System (ADS)

    Baeza-Rojano, Elena; Calero-Cano, Sandra; Hachero-Cruzado, Ismael; Guerra-García, José Manuel

    2013-10-01

    The caprellid amphipod Caprella scaura Templeton, 1836 was investigated as a mass culture organism, for potential use as natural prey in aquaculture. C. scaura showed good population growth during 3 months of culturing with nauplii of Artemia sp. and microalgae as food source. A final mean population size of 12,510.67 individuals/tank and a maximum density of 10,460 individuals m- 2 were obtained; a 50-fold increase of the initial population was observed. Juveniles were the most abundant stage in the culture (86.0% of total), followed by mature females (5.4%) and immature males (3.1%). Three kinds of plastic mesh with different complexity levels were used as artificial substrates for amphipods to attach to and shelter. There were no significant differences in the total number of individuals present on each kind of mesh, although female and male adults were more abundant in folded meshes with larger pore diameter. This research demonstrated that the caprellid amphipod C. scaura may be readily cultured at high densities with a variety of mesh morphologies allowing more efficient use of tank volume and improved handling.

  6. Assessing estuarine quality: A cost-effective in situ assay with amphipods.

    PubMed

    Martinez-Haro, Monica; Acevedo, Pelayo; Pais-Costa, Antónia Juliana; Taggart, Mark A; Martins, Irene; Ribeiro, Rui; Marques, João Carlos

    2016-05-01

    In situ assays based on feeding depression can be powerful ecotoxicological tools that can link physiological organism-level responses to population and/or community-level effects. Amphipods are traditional target species for toxicity tests due to their high sensitivity to contaminants, availability in the field and ease of handling. However, cost-effective in situ assays based on feeding depression are not yet available for amphipods that inhabit estuarine ecosystems. The aim of this work was to assess a short-term in situ assay based on postexposure feeding rates on easily quantifiable food items with an estuarine amphipod. Experiments were carried out under laboratory conditions using juvenile Echinogammarus marinus as the target individual. When 60 Artemia franciscana nauplii (as prey) were provided per individual for a period of 30 min in dark conditions, feeding rates could be easily quantified. As an endpoint, postexposure feeding inhibition in E. marinus was more sensitive to cadmium contamination than mortality. Assay calibration under field conditions demonstrated the relevance of sediment particle size in explaining individual feeding rates in uncontaminated water bodies. An evaluation of the 48-h in situ bioassay based on postexposure feeding rates indicated that it is able to discriminate between unpolluted and polluted estuarine sites. Using the harmonized protocol described here, the in situ postexposure feeding assay with E. marinus was found to be a potentially useful, cost-effective tool for assessing estuarine sediment and water quality. PMID:26874320

  7. Rapid digestion and assimilation of bait by the deep-sea amphipod Eurythenes gryllus

    NASA Astrophysics Data System (ADS)

    Hargrave, B. T.; Phillips, G. A.; Prouse, N. J.; Cranford, P. J.

    1995-11-01

    Scavenging lysianassoid amphipods ( Eurythenes gryllus) were collected with a newly designed trap to measure digestion rates with timed exposure to bait in the Canada Basin of the Arctic Ocean (2075 m) and in the Nares (3521 m) and Sohm Abyssal (4978 m) Plains, northeast Atlantic Ocean. In feeding experiments up to 157 h long, water and organic matter content were not significantly different in anterior, central and hind gut regions of individual amphipods, showing that digestion in E. gryllus conforms to the batch reactor feeding model. Ingested bait was rapidly solubilized and water content increased from < 70% to > 90% within 69 h. Digestion rates, calculated from exponential curves fitted to decreases in gut contents for dry matter and various organic components, were very high (2.1-6.5% loss h -1) for sardines ingested during short (6-11 h) incubation periods in the Canada Basin. Mackerel ingested by amphipods trapped in the Nares and Sohm Abyssal Plains were digested at lower rates (0.4-1.0% loss h -1) in in situ experiments up to 123 h. Allometric regressions described relationships between body length and calories potentially available for assimilation from one meal by male and female instars. Rapid digestion in opportunistic scavengers like E. gryllus makes gut capacity available for additional feeding when food supply is unpredictable.

  8. Digestive capabilities reflect the major food sources in three species of talitrid amphipods.

    PubMed

    Johnston, Matthew; Johnston, Danielle; Richardson, Alastair

    2005-02-01

    Digestive enzyme activities of three talitrid amphipods were examined to investigate the relationship between their digestive capabilities and diet. Laminarinase, cellobiase, carboxymethyl-cellulase, xylanase, alpha- and beta-glucosidase and lipase were detected in all three species suggesting talitrid amphipods can readily digest dietary carbohydrate and lipid, including complex polysaccharides. Relatively high specific enzyme activity (Units (mg(-1) digestive tract protein)(-1)) of laminarinase and lipase was detected in Talorchestia marmorata, a supralittoral kelp feeder which is coherent with the digestion of lipid-esters and beta-glucans (laminarin) which are the main lipid and storage polysaccharides of brown seaweeds. Talorchestia sp., a low shore intertidal feeder, had high enzymatic activity of alpha- and beta-glucosidase, cellobiase and xylanase, which is consistent with the digestion of diatoms. Keratroides vulgaris, a forest litter feeder had a relatively low specific activity of all enzymes. It is possible that leaf litter is partially digested prior to ingestion by bacteria and fungi present in the rotting vegetation, with bacterial and fungal enzymes contributing to this species' ability to hydrolyse its diet. This study provides the first quantitative data on digestive capacity in these three talitrid amphipods and confirms the relationship between dietary preference and digestive enzyme complement. PMID:15649772

  9. Effect of CO2-related acidification on aspects of the larval development of the European lobster, Homarus gammarus (L.)

    NASA Astrophysics Data System (ADS)

    Arnold, K. E.; Findlay, H. S.; Spicer, J. I.; Daniels, C. L.; Boothroyd, D.

    2009-08-01

    Oceanic uptake of anthropogenic CO2 results in a reduction in pH termed "Ocean Acidification" (OA). Comparatively little attention has been given to the effect of OA on the early life history stages of marine animals. Consequently, we investigated the effect of culture in CO2-acidified sea water (approx. 1200 ppm, i.e. average values predicted using IPCC 2007 A1F1 emissions scenarios for year 2100) on early larval stages of an economically important crustacean, the European lobster Homarus gammarus. Culture in CO2-acidified sea water did not significantly affect carapace length of H. gammarus. However, there was a reduction in carapace mass during the final stage of larval development in CO2-acidified sea water. This co-occurred with a reduction in exoskeletal mineral (calcium and magnesium) content of the carapace. As the control and high CO2 treatments were not undersaturated with respect to any of the calcium carbonate polymorphs measured, the physiological alterations we record are most likely the result of acidosis or hypercapnia interfering with normal homeostatic function, and not a direct impact on the carbonate supply-side of calcification per se. Thus despite there being no observed effect on survival, carapace length, or zoeal progression, OA related (indirect) disruption of calcification and carapace mass might still adversely affect the competitive fitness and recruitment success of larval lobsters with serious consequences for population dynamics and marine ecosystem function.

  10. Effect of CO2-related acidification on aspects of the larval development of the European lobster, Homarus gammarus (L.)

    NASA Astrophysics Data System (ADS)

    Arnold, K. E.; Findlay, H. S.; Spicer, J. I.; Daniels, C. L.; Boothroyd, D.

    2009-03-01

    Oceanic uptake of anthropogenic CO2 results in a reduction in pH termed "Ocean Acidification" (OA). Comparatively little attention has been given to the effect of OA on the early life history stages of marine animals. Consequently, we investigated the effect of culture in CO2-acidified sea water (approx. 1200 ppm, i.e. average values predicted using IPCC 2007 A1F1 emissions scenarios for year 2100) on early larval stages of an economically important crustacean, the European lobster Homarus gammarus. Culture in CO2-acidified sea water did not significantly affect carapace length or development of H. gammarus. However, there was a reduction in carapace mass during the final stage of larval development in CO2-acidified sea water. This co-occurred with a reduction in exoskeletal mineral (calcium and magnesium) content of the carapace. As the control and high CO2 treatments were not undersaturated with respect to any of the calcium carbonate polymorphs measured, the physiological alterations we record are most likely the result of acidosis or hypercapnia interfering with normal homeostatic function, and not a direct impact on the carbonate supply-side of calcification per se. Thus despite there being no observed effect on survival, carapace length, or zoeal progression, OA related (indirect) disruption of calcification and carapace mass might still adversely affect the competitive fitness and recruitment success of larval lobsters with serious consequences for population dynamics and marine ecosystem function.

  11. Effects of sediment characteristics on the toxicity of chromium(III) and chromium(VI) to the amphipod, Hyalella azteca

    USGS Publications Warehouse

    Besser, J.M.; Brumbaugh, W.G.; Kemble, N.E.; May, T.W.; Ingersoll, C.G.

    2004-01-01

    We evaluated the influence of sediment characteristics, acid-volatile sulfide (AVS) and organic matter (OM), on the toxicity of chromium (Cr) in freshwater sediments. We conducted chronic (28-42-d) toxicity tests with the amphipod Hyalella azteca exposed to Cr(VI) and Cr(III) in water and in spiked sediments. Waterborne Cr(VI) caused reduced survival of amphipods with a median lethal concentration (LC50) of 40 ??g/L. Cr(VI) spiked into test sediments with differing levels of AVS resulted in graded decreases in AVS and sediment OM. Only Cr(VI)-spiked sediments with low AVS concentrations (<1 ??mol/g) caused significant amphipod mortality. Waterborne Cr(III) concentrations near solubility limits caused decreased survival of amphipods at pH 7 and pH 8 but not at pH 6. Sediments spiked with high levels of Cr(III) did not affect amphipod survival but had minor effects on growth and inconsistent effects on reproduction. Pore waters of some Cr(III)-spiked sediments contained measurable concentrations of Cr(VI), but observed toxic effects did not correspond closely to Cr concentrations in sediment or pore waters. Our results indicate that risks of Cr toxicity are low in freshwater sediments containing substantial concentrations of AVS.

  12. A biodynamic model predicting waterborne lead bioaccumulation in Gammarus pulex: Influence of water chemistry and in situ validation.

    PubMed

    Urien, N; Uher, E; Billoir, E; Geffard, O; Fechner, L C; Lebrun, J D

    2015-08-01

    Metals bioaccumulated in aquatic organisms are considered to be a good indicator of bioavailable metal contamination levels in freshwaters. However, bioaccumulation depends on the metal, the species, and the water chemistry that influences metal bioavailability. In the laboratory, a kinetic model was used to describe waterborne Pb bioaccumulated in Gammarus pulex. Uptake and elimination rate constants were successfully determined and the effect of Ca(2+) on Pb uptake was integrated into the model. Thereafter, accumulated Pb concentrations in organisms were predicted with the model and compared with those measured in native populations from the Seine watershed (France). The predictions had a good agreement with the bioaccumulation levels observed in native gammarids and particularly when the effect of calcium was considered. To conclude, kinetic parameters experimentally derived for Pb in G. pulex are applicable in environmental conditions. Moreover, the consideration of the water's chemistry is crucial for a reliable interpretation of bioaccumulation. PMID:25845358

  13. Effect of the copepod parasite Nicothoë astaci on haemolymph chemistry of the European lobster Homarus gammarus.

    PubMed

    Davies, Charlotte E; Vogan, Claire L; Rowley, Andrew F

    2015-03-01

    The gills of the European lobster Homarus gammarus (L.) are susceptible to parasitization by the copepod Nicothoë astaci, the lobster louse. This copepod feeds on haemolymph of the host and can damage the gills, potentially affecting gaseous exchange capabilities. To investigate the host response to the parasite, haemolymph levels of total protein, haemocyanin, glucose and ammonia were quantified in adult lobsters carrying varying parasite loads. Parasite loads correlated positively with total haemolymph protein and haemocyanin concentrations but not with glucose or ammonia concentrations. The data suggest that lobsters with gills damaged by the feeding activities of N. astaci respond by producing higher levels of haemocyanin, which is both a key defence response and may compensate for their decreased respiratory functioning. PMID:25751860

  14. Invasive Ponto-Caspian Amphipods and Fish Increase the Distribution Range of the Acanthocephalan Pomphorhynchus tereticollis in the River Rhine

    PubMed Central

    Emde, Sebastian; Rueckert, Sonja; Palm, Harry W.; Klimpel, Sven

    2012-01-01

    Non-indigenous species that become invasive are one of the main drivers of biodiversity loss worldwide. In various freshwater systems in Europe, populations of native amphipods and fish are progressively displaced by highly adaptive non-indigenous species that can perform explosive range extensions. A total of 40 Ponto-Caspian round gobies Neogobius melanostomus from the Rhine River near Düsseldorf, North Rhine-Westphalia, Germany, were examined for metazoan parasites and feeding ecology. Three metazoan parasite species were found: two Nematoda and one Acanthocephala. The two Nematoda, Raphidascaris acus and Paracuaria adunca, had a low prevalence of 2.5%. The Acanthocephala, Pomphorhynchus tereticollis, was the predominant parasite species, reaching a level of 90.0% prevalence in the larval stage, correlated with fish size. In addition, four invasive amphipod species, Corophium curvispinum (435 specimens), Dikerogammarus villosus (5,454), Echinogammarus trichiatus (2,695) and Orchestia cavimana (1,448) were trapped at the sampling site. Only D. villosus was infected with P. tereticollis at a prevalence of 0.04%. The invasive goby N. melanostomus mainly preys on these non-indigenous amphipods, and may have replaced native amphipods in the transmission of P. tereticollis into the vertebrate paratenic host. This study gives insight into a potential parasite-host system that consists mainly of invasive species, such as the Ponto-Caspian fish and amphipods in the Rhine. We discuss prospective distribution and migration pathways of non-indigenous vertebrate (round goby) and invertebrates (amphipods) under special consideration of parasite dispersal. PMID:23300895

  15. Seasonal analysis of semen characteristics, serum testosterone and fecal androgens in the ocelot (Leopardus pardalis), margay (L. wiedii) and tigrina (L. tigrinus).

    PubMed

    Morais, R N; Mucciolo, R G; Gomes, M L F; Lacerda, O; Moraes, W; Moreira, N; Graham, L H; Swanson, W F; Brown, J L

    2002-05-01

    Captive adult male ocelots (Leopardus pardalis, n = 3), margays (L. wiedii, n = 3) and tigrinas (L. tigrinus, n = 4) in two locations in southern Brazil were studied for 14 consecutive months to evaluate the effect of season on testicular function. Reproductive evaluations, including testicular measurements, electroejaculation and blood collection were conducted monthly. Fecal samples were collected weekly for androgen metabolite analysis to assess testicular steroidogenic activity. Ocelots had the highest number of motile spermatozoa in the ejaculate (114.7+/-15.8 x 10(6); P < 0.05), the highest percentage of morphologically normal spermatozoa (82.4+/-1.2%; P < 0.05) and the highest concentration of fecal androgens (1.71 vs. 0.14 microg/g; P < 0.05). Margays and tigrinas had lower numbers of motile spermatozoa (23.4+/-2.8 x 10(6), 74.2+/-8.9 x 10(6), respectively), lower percentages of morphologically normal spermatozoa (57.4+/-2.8, 59.2+/-3.5%, respectively), and lower fecal androgen concentrations (0.15+/-0.01, 0.23+/-0.01 microg/g, respectively). Serum testosterone concentrations were similar among the three species. Fecal androgen concentrations were not affected by season, with the exception of the ocelot where concentrations were higher (P < 0.05) in the summer. Ejaculates were collected throughout the year; however, peaks in average sperm production were observed during the summer for all species. In summary, this study has identified several species differences in male testicular traits among ocelots, margays and tigrinas. Results of longitudinal reproductive assessments suggest males of each species are capable of breeding throughout the year. PMID:12066863

  16. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (Pacific Northwest): Amphipods. [Gammaridea; Hyperidea; Caprellidea

    SciTech Connect

    Grosse, D.J.; Pauley, G.B.; Moran, D.

    1986-08-01

    Amphipods are ubiquitous in distribution. Hyperiidea are the third most abundant coastal marine crustacean zooplankton, following copepods and euphausids. Benthic Gammaridea are an invaluable food source for many economically important fish and invertebrate species. Lifestyles of the major amphipod groups are varied. On the basis of the Index of Relative Importance (IRI), they comprise more than half of the total IRI spectrum for 38 of 55 fish species in the Strait of Juan de Fuca. They are reported to be indicators of heavily polluted areas.

  17. Comparison of the partitioning of pesticides relative to the survival and behaviour of exposed amphipods.

    PubMed

    Hellou, Jocelyne; Leonard, Jim; Cook, Art; Doe, Ken; Dunphy, Kathryn; Jackman, Paula; Tremblay, Laurie; Flemming, Joanna Mills

    2009-01-01

    Pesticides sprayed on farmlands can end up in rivers and be transported into estuaries, where they could affect aquatic organisms in freshwater and marine habitats. A series of experiments were conducted using the amphipod Corophium volutator Pallas (Amphipoda, Corophiidae) and single pesticides, namely atrazine (AT), azinphos-methyl (AZ), carbofuran (CA) and endosulfan (EN) that were added to sediments and covered with seawater. Our goal was to compare the concentrations affecting the survival of the animals relative to potential attractant or repellent properties of sediment-spiked pesticides. The avoidance/preference of contaminated/reference sediments by amphipods was examined after 48 and 96 h of exposure using sediments with different organic carbon content. The octanol-water partition coefficients (log K(ow)) ranked the pesticides binding to sediments as EN > AZ > AT > CA. LC(50) and LC(20) covered a wide range of nominal concentrations and ranked toxicity as CA-AZ > EN > AT. Under the experimental set up, only EN initiated an avoidance response and the organic carbon normalised concentration provided consistent results. Using the present data with wide confidence limits, >20% of a population of C. volutator could perish due to the presence of EN before relocation or detecting CA or AZ in sediments by chemical analysis. PMID:18785007

  18. Antioxidant response to natural organic matter (NOM) exposure in three Baikalean amphipod species from contrasting habitats.

    PubMed

    Timofeyev, M A; Steinberg, C E W

    2006-10-01

    The aim of the present work is to comparatively evaluate the oxidative stress response on exposure to natural organic matter (NOM) in three amphipod (Crustacea, Amphipoda) species from different taxonomic groups and different habitats of Lake Baikal. Endemic species from Lake Baikal were used: the shallow-water dwelling Gmelinoides fasciatus (Dyb.), Pallasea cancelloides (Gerstf.), and the deep-layer inhabitant Ommatogammarus flavus (Dyb.). Three key enzymes, catalase (CAT), peroxidase (POD), and glutathione S-transferase (GST), were studied. The applied NOM from Lake Schwarzer (Germany) directly impacts the two littoral species which quickly respond. The response is characterized by a significant decrease of POD and an increase of CAT activities. GST activity remains stable or decreased slightly. In contrast to the littoral amphipods, the deep-layer inhabitant O. flavus showed no significant reaction to NOM exposure, probably due to decreased adaptive ability of this species. The stable environment of the Baikalean deep zones obviously does not provide triggers for the development of flexible antioxidant or general defense systems. PMID:16914340

  19. Acute and chronic toxicity of lead in water and diet to the amphipod Hyalella azteca

    USGS Publications Warehouse

    Besser, J.M.; Brumbaugh, W.G.; Brunson, E.L.; Ingersoll, C.G.

    2005-01-01

    We evaluated the influence of waterborne and dietary lead (Pb) exposure on the acute and chronic toxicity of Pb to the amphipod Hyalella azteca. Test solutions were generated by a modified diluter with an extended (24-h) equilibration period. Acute (96-h) toxicity of Pb varied with water hardness in the range of 71 to 275 mg/L as CaCO3, despite similar dissolved Pb concentrations. Acute toxicity was greatest in soft test water, with less than 50% survival at the lowest dissolved Pb concentration (151 ??g/L). Survival also was significantly reduced in medium-hardness water but not in hard test water. In chronic (42-d) studies, amphipods were exposed to waterborne Pb and fed either a control diet or a diet equilibrated with waterborne Pb levels. For animals fed the control diet, the median lethal concentration (LC50) for Pb was 24 ??g/L (as dissolved Pb), and significant reductions in survival occurred at 16 ??g/L. Exposure to Pb-treated diets significantly increased toxicity across a wide range of dissolved Pb concentrations, with a LC50 of 16 ??g/L and significant reductions in growth and reproduction at 3.5 ??g/L. Significant effects on growth and reproduction occurred at dissolved Pb concentrations close to the current U.S. chronic water-quality criterion. Our results suggest that both aqueous- and dietary-exposure pathways contribute significantly to chronic Pb exposure and toxic effects in aquatic biota. ?? 2005 SETAC.

  20. Seasonal variability of metabolic markers and oxidative balance in freshwater amphipod Hyalella kaingang (Crustacea, Amphipoda).

    PubMed

    Braghirolli, Fernando Machado; Oliveira, Maiara Rodriguez; Oliveira, Guendalina Turcato

    2016-08-01

    Amphipods are widely used as bioindicator organisms, in view of their ease of collection and cultivation, sexual dimorphism and abundance, in aquatic environments. In the present study male (n=30) and female (n=30) amphipod Hyalella kaingang were collected during the middle of each season from a nature preserve (Research Center PRÓ-MATA) in São Francisco de Paula, Southern Brazil. Proteins, glycogen, lipids, triglycerides, glycerol, and lipid peroxidation (superoxide dismutase, catalase, and glutathione S-transferase activity) were measured. The results obtained for the markers of energy metabolism, antioxidant enzymes, and lipid peroxidation revealed a clear seasonal variation. The patterns of proteins, glycerol, and glutathione S-transferase activity did not differ between sexes; conversely, differential responses in males and females over the year were observed for all other parameters (glycogen, lipids, triglycerides, lipid peroxidation, and superoxide dismutase and catalase activity). These responses appear to be strongly influenced by a prolonged reproductive period (autumn through spring, peaking in autumn); by the degree of exploratory activity, particularly in the summer and autumn; and by abiotic factors, such as temperature and photoperiod. The responses observed in the summer and autumn (decrease in levels of proteins, glycogen and fats, and increase in lipid peroxidation levels and glutathione S-transferase activity), suggest that this season represents a critical time point for these animals. The parameters studied herein may be used as biomarkers to assess the environmental conditions in the aquatic habitat. PMID:27107775

  1. Reproductive pattern of the epifaunal amphipod Pontogeneia rostrata (Crustacea) on dolsando sandy shore in Korea

    NASA Astrophysics Data System (ADS)

    Yu, Ok Hwan; Jeong, Seung Jin; Suh, Hae-Lip

    2008-09-01

    Reproductive patterns of an epifaunal amphipod, Pontogeneia rostrata, were studied on Dolsando sandy shore in Korea. The life history pattern was iteroparous, with recruitment mainly occurring from winter to spring. The sex ratio was male-biased, especially during breeding periods. The mean body length of females was significantly larger than that of males. Brood size and egg volume were positively related to the body length of ovigerous females. There was no significant difference in brood size between successive breeding periods, but egg volumes were significantly higher in early winter (December) than in late spring breeding (May and June), increasing the probability of survival to hatching. These traits contribute to more reproductive potential in early winter than in late spring breeding. The mean brood size of epifaunal P. rostrata was larger but the mean egg volume smaller than that of infaunal amphipods in this sampling area. We suggest that reproductive effort for epifaunal species may be proportionally greater than for infaunal species in risky environments.

  2. Measurement and reduction of porewater ammonia in 10-day sediment toxicity tests with marine amphipods

    SciTech Connect

    Kohn, N.P.; Karls, R.K.; Barrows, M.E.

    1994-12-31

    Ammonia is recognized as a potential contributor to amphipod toxicity in sediment bioassays, such as those required for dredged material testing. Measurement of ammonia in sediment porewater prior to testing and monitoring of ammonia during testing have not been routinely performed. The U.S. Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers (USACE) have recently provided guidance for reducing sediment porewater ammonia by aeration and by exchange of overlying water prior to introducing test animals. In this study, two amphipod species, Rhepoxynius abronius and Eohaustorius estuarius, were exposed to eight sediment treatments in 10-day solid-phase static bioassays. Ammonia in sediment porewater was measured prior to testing; treatments with > 70 mg/L total ammonia were manipulated to reduce porewater ammonia in the test chambers to {<=}30 mg/L, following procedures in a memorandum by EPA and USACE. Porewater ammonia was also measured {approximately}24 h after test set up (when animals would normally be added), each day of manipulation before animals were added, and also on Days 5 and 9 for the E. estuarius test. The treatment with the highest porewater ammonia concentration was tested with and without manipulation. Reduction of porewater ammonia required up to 2 days. Toxicity was reduced in the manipulated sediments, but was statistically significant relative to control and reference treatments.

  3. Interlaboratory comparison of standardized sediment toxicity test methods using estuarine and marine amphipods

    SciTech Connect

    Schlekat, C.E.; Scott, J.; Armitage, T.M.; Swartz, R.C.

    1994-12-31

    USEPA`s Office of Science and Technology has developed standardized sediment toxicity test methods that use four estuarine and marine amphipod species. An interlaboratory comparison was conducted to evaluate the precision of these methods. This comparison included three species, Ampelisca abdita, Eohaustorius estuarius, and Leptocheirus plumulosus. A similar study with the fourth species, Rhepoxynius abronius, has already been conducted. A matrix of ten participating laboratories, including both government and contract laboratories, ensure that each species was tested by at least six laboratories. Each species was exposed for 10 d under static, non-renewal conditions to four sediment treatments using standardized, species-specific test protocols. Sediment treatments were selected for each species to include one negative control sediment and three contaminated sediments. Highly contaminated sediment from Black Rock Harbor, CT, was diluted with species-specific, non-contaminated control sediment, creating test sediments that ranged in relative contamination from low to high. Each laboratory also conducted 4-d water-only reference toxicant tests with Cd. Independent suppliers distributed amphipods to each laboratory. Results of sediment exposures were analyzed to evaluate (1) the magnitude of variability for each treatment among laboratories, (2) differences in mean survival for each species among laboratories, and (3) differences in rank survival for each species among laboratories.

  4. Life history and population dynamics of an estuarine amphipod, Eriopisa chilkensis Chilton (Gammaridae)

    NASA Astrophysics Data System (ADS)

    Aravind, Nisha P.; Sheeba, P.; Nair, K. K. C.; Achuthankutty, C. T.

    2007-08-01

    The life cycle of the gammarid amphipod Eriopisa chilkensis Chilton from the Cochin estuary, south west coast of India, has been studied for the first time under laboratory conditions. Amphipods, especially gammarids, are used as potential live feed in fish culture. Eriopisa chilkensis can withstand wide variations in salinity (5-35) and temperature (27.5-34 °C) of the medium. It was cultured in un-aerated finger bowls using dried algal matter ( Chara sp.) as food. The life span of females was found to be higher (maximum: 220 days) than males (maximum: 175 days). Females were iteroparous and attained sexual maturity within 39.3 ± 6 days (mean ± SD), whereas males matured within 26.5 ± 5.6 days. Number of broods in a life span ranged from 4 to 7. The maximum number of juveniles produced in a single brood was 29 and the maximum number of juveniles produced by a single female over a lifetime was 139. The duration of embryonic development was 12 ± 2.45 days. The population dynamics of E. chilkensis was studied based on monthly sampling, over one year from the mangrove swamps of Puduvypin. It occurred in varying densities in the epifaunal community (21-1583 ind. m -2). Extrapolation of laboratory data to the field suggests that E. chilkensis in Cochin estuary has a multivoltine life cycle.

  5. Deep-sea scavenging amphipod assemblages from the submarine canyons of the Western Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Duffy, G. A.; Horton, T.; Billett, D. S. M.

    2012-11-01

    Submarine canyons have often been identified as hotspots of secondary production with the potential to house distinct faunal assemblages and idiosyncratic ecosystems. Within these deep-sea habitats, assemblages of scavenging fauna play a vital role in reintroducing organic matter from large food falls into the wider deep-sea food chain. Free-fall baited traps were set at different depths within three submarine canyons on the Iberian Margin. Amphipods from the traps were identified to species level and counted. Scavenging amphipod assemblages were compared at different depths within each canyon and between individual canyon systems. Using data from literature, abyssal plain assemblages were compared to submarine canyon assemblages. Samples from canyons were found to contain common abyssal plain species but in greater than expected abundances. It is proposed that this is a result of the high organic carbon input into canyon systems owing to their interception of sediment from the continental shelf and input from associated estuarine systems. Community composition differed significantly between the submarine canyons and abyssal plains. The cause of this difference cannot be attributed to one environmental variable due to the numerous inherent differences between canyons and abyssal plains.

  6. Effects of sediment amended with Deepwater Horizon incident slick oil on the infaunal amphipod Leptocheirus plumulosus.

    PubMed

    Lotufo, Guilherme R; Farrar, J Daniel; Biedenbach, James M; Laird, Jennifer G; Krasnec, Michelle O; Lay, Claire; Morris, Jeffrey M; Gielazyn, Michel L

    2016-08-15

    Crude oil released from the Deepwater Horizon disaster into the Gulf of Mexico posed potential impacts to infaunal invertebrates inhabiting near shore habitats. The effects of sediment-associated weathered slick oil on the amphipod Leptocheirus plumulosus was assessed using 28-d exposures to total PAH sediment concentrations ranging from 0.3 to 24mg/kg (sum of 50 PAHs or tPAH50). Survival and growth rate were significantly decreased in the 2.6, 11.4 and 24.2mg/kg treatments, but only growth in 5.5mg/kg. Offspring production was dramatically decreased but was variable and significantly different only for 24.2mg/kg. The concentrations associated with 20% decreases relative to reference were 1.05 (95% CI=0-2.89) mg/kg tPAH50 for growth rate and 0.632 (95% CI=0.11-2.15) mg/kg tPAH50 for offspring production. The concentrations of PAHs affecting amphipods are within the range of concentrations measured in marsh areas reportedly impacted by DWH oil after its release. PMID:27267114

  7. Critical body residues in the marine amphipod Ampelisca abdita: Sediment exposures with nonionic organic contaminants

    SciTech Connect

    Fay, A.A.; Brownawell, B.J.; Elskus, A.A.; McElroy, A.E.

    2000-04-01

    Body residues associated with acute toxicity were determined in the marine amphipod Ampelisca abdita exposed to spiked sediments. Nonylphenol and 2,2{prime},4,4{prime}-tetrachlorobiphenyl critical body residues (CBRs, body residue of contaminant at 50% mortality) were 1.1 {micro}mol/g wet tissue and 0.57 {micro}mol/g wet tissue, respectively, values near the low end of the CBR range expected for compounds acting via narcosis. The polycyclic aromatic hydrocarbons tested, benzo[a]pyrene (BaP) and benz[a]anthracene (BaA), were not acutely toxic at exposure concentrations of up to 43 and 1,280 {micro}g/g dry sediment for BaA and BaP respectively, and body burdens up to 1.2 {micro}mol/g wet tissue (for BaP). Neither polycyclic aromatic hydrocarbon (PAH) was significantly metabolized by A. abdita. The microextraction technique employed here allowed residue analysis of samples containing as few as three amphipods (0.33 mg dry wt). The CBR approach avoids confounding factors such as variations in bioavailability and uptake kinetics and could be employed to assess the relative contribution of specific contaminants or contaminant classes in mixtures to effects observed in toxicity tests with Ampelisca and other organisms.

  8. An investigation into intersex amphipods and a possible association with aquaculture.

    PubMed

    Ford, Alex T; Read, Paul A; Jones, Tim L; Michino, Fumiko; Pang, Yvonne; Fernandes, Teresa F

    2007-10-01

    The amphipod, Echinogammarus marinus, is common in sheltered coastal inlets, such as estuaries and sea lochs, in Scotland and exhibits increased levels of intersex in some contaminated areas. Sea lochs are commonly the location for coastal aquaculture development, and some chemicals used in fish-farming are specifically designed to target the crustacean nervous system. Therefore it was hypothesised that these chemicals may also affect neuro-endocrine pathways, causing morphological and reproductive abnormalities in non-target Crustacea. Based upon this hypothesis, Echinogammarus marinus amphipods from two different Scottish sea lochs containing salmon farms were investigated. Morphology, intersexuality, and the incidence of microsporidian parasites were recorded at sites close and at distance from fish-farms. Results suggest a higher incidence of intersexuality at sites within sea lochs, comparable to that observed in industrially contaminated sites elsewhere in Scotland. The data suggest that fish farming activity may influence the observed distributions of intersexuality within lochs. Intersex specimens were more likely to be infected by microsporidian parasites than non-intersex specimens. Normal females were found more likely to be infected by microsporidian parasites at sites associated with high intersexuality, suggesting the parasite as the probable feminiser. The cause(s) for the observed patterns of intersexuality are unclear, although suggestions relating to discharges from fish farms are discussed. PMID:17499352

  9. Toxic effects of antiparasitic pesticides used by the salmon industry in the marine amphipod Monocorophium insidiosum.

    PubMed

    Tucca, Felipe; Díaz-Jaramillo, Mauricio; Cruz, Gabriel; Silva, Jeannette; Bay-Schmith, Enrique; Chiang, Gustavo; Barra, Ricardo

    2014-08-01

    The use of antiparasitic pesticides (APs) has been widely required by the salmon industry to treat diseases. The direct emission of chemicals in the seawater has produced uncertainty about the potential effects on nontarget organisms, such as crustaceans. The aim of this study was to assess the toxicity of three APs used by the salmon farm industry, such as emamectin benzoate (EB), cypermethrin (CP), and deltamethrin (DE), in the amphipod Monocorophium insidiosum during 10 days through whole-sediment bioassay tests. Lethal concentration by 50 % (LC50-10d) and biochemical responses, such as glutathione S-transferase (GST) and thiobarbituric acid reactive substances (TBARS), were measured as exposure and effects end points, respectively. Acute assays for DE (7.8 μg kg(-1), confidence interval, CI95% 5-11) and CP (57 μg kg(-1), CI95% 41-77) showed more mortality than EB (890 μg kg(-1), CI95% 672-1,171). In this study, it was possible to observe sublethal responses in amphipods after 2 days of exposure to APs. Significant induction in GST and TBARS (p < 0.05) were measured for CP and EB. Lower DE concentrations showed no significant biochemical responses. M. insidiosum was sensitive to AP concentrations at μg kg(-1) in sediments. This information would allow considering the possible consequences of detected concentrations for APs in areas with intensive salmon farming activity. PMID:24609616

  10. Factors Affecting the Distribution of the Amphipod Corophium volutatorin Two Estuaries in South-east England

    NASA Astrophysics Data System (ADS)

    Hughes, R. G.; Gerdol, V.

    1997-05-01

    The distribution of Corophium volutator(Pallas) in the estuaries of the Rivers Blackwater and Crouch in South-east England was examined by taking samples of mud from 137 sites at approximately 0·5 m below mean high water of neap tidal level. Corophium volutatorwere approximately twice as abundant in creeks and semi-enclosed bays than on the open mud flats, a difference that was significant statistically. There was no correlation between the abundance of C. volutatorand the median particle size of the sediment nor the mud content. There was a significant but weak negative correlation between the abundance of C. volutatorand the polychaete Nereis diversicolor. The aggregation of C. volutatorin the creeks and bays was attributed to their dispersal behaviour of swimming on the flood tide, which would sweep the amphipods into such areas where the tide rises but does not flow laterally. On the open mud flats, displacement of swimming amphipods by the flood tide further upstream and into semi-enclosed areas would occur. Their dispersal behaviour places C. volutatorin the creeks and bays within the saltmarsh vegetation, where their bioturbatory feeding habits may be responsible, in part, for the significant loss of pioneer zone vegetation that occurs there.

  11. The tropical caprellid amphipod Paracaprella pusilla: a new alien crustacean in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Ros, Macarena; Vázquez-Luis, Maite; Guerra-García, José Manuel

    2013-12-01

    Paracaprella pusilla Mayer (Fauna und Flora des Golfes von Neapel 17:1-55, 1890), originally described from Brazil, is one of the most abundant caprellid amphipod species in tropical and subtropical seas around the world. During a survey of caprellid amphipods from marinas along the Balearic Island (Western Mediterranean Sea) carried out between November 2011 and August 2012, we found two established populations of P. pusilla in Mallorca and Ibiza, respectively. So far, its occurrence in European waters was reported only from southwestern Spain in 2010. This record represents a northward range expansion of the species' distribution, which is found for the first time in the Mediterranean. This is also the first record of the genus Paracaprella in the Mediterranean Sea. The most probable introduction vector was ship fouling. We also found the invasive caprellid Caprella scaura Templeton (Trans Entomol Soc Lond 1:185-198, 1836) in Mallorca and Menorca, which is recorded for the first time in the Balearic Islands, confirming its rapid expansion along the Mediterranean. When comparing reproductive traits between both alien species, we found that P. pusilla has a higher fecundity than C. scaura for the same female size. Taking into account this evidence, the species may be expected to appear in other Mediterranean and adjacent areas.

  12. Genetic structure of the benthic amphipod Diporeia (Amphipoda: Pontoporeiidae) and its relationship to abundance in Lake Superior

    EPA Science Inventory

    The freshwater amphipod Diporeia is a crucial part of the food web in the Laurentian Great Lakes, but has faced serious declines correlated with the invasion of zebra mussels (Dreissena polymorpha), except in Lake Superior, which has seen an increase in Diporeia abundance. Specul...

  13. Phototoxicity of TiO2 nanoparticles to a freshwater benthic amphipod: are benthic systems at risk?

    EPA Science Inventory

    This study investigated phototoxicity of TiO2 nanoparticles (nano-TiO2) to a freshwater benthic amphipod (Hyalella azteca) using 48-h and 96-h bioassays. Thorough monitoring of particle interactions with exposure media (Lake Superior water, LSW) and the surface of organisms was p...

  14. Use of fluorometrically determined gut chlorophyll-a concentrations to assess toxicity of sediments to the amphipod Ampelisca verrilli

    SciTech Connect

    Maier, P.P.; Van Dolah, R.F.; Jones, J.D.

    1995-12-31

    Concentrations of contaminants which do not cause measurable mortality in traditional acute bioassays may cause sublethal effects including reduction in the ability of amphipods to collect and ingest food. Measurement of feeding efficiency can provide an early indication of toxic stress and it may represent a more sensitive measure of sediment toxicity. Experiments conducted in this study utilize a fluorometric method of chlorophyll determination to quantify feeding of Ampelisca verrilli. Replicate 500 ml beakers with 150 ml of test or control sediment and 300 ml of seawater are inoculated with ten amphipods. At the end of a 96 hour exposure period, concentrated algae is added to bring each beaker concentration up to 500,000 cells/ml. After feeding for 1 hour, amphipods are collected by sieving and weighed. The animals from each container are then ground in buffered acetone, centrifuged, and the chlorophyll-a concentration of the supernatant is measured. The final concentrations are expressed as {micro}g chl-a/mg wet-weight of amphipod. Results obtained from feeding assays using toxic sediments will be compared with data obtained from standard 10-day sediment toxicity tests to evaluate the relative sensitivity of this sublethal endpoint.

  15. Evaluation of the Influence of Bromide or Iodide on the Performance the Amphipod Hyalella azteca in Reconstituted Waters

    EPA Science Inventory

    Survival, growth, or reproduction of the amphipod Hyalella azteca (HA) is reported to be poor when some reconstituted waters have been used to conduct chronic (>14-d) water-only or sediment toxicity tests, including ASTM reconstituted hard water (with no addition of Bromi...

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

    SciTech Connect

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

    2000-06-01

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

  17. Sensitivity of the deep-sea amphipod Eurythenes gryllus to chemically dispersed oil.

    PubMed

    Olsen, Gro Harlaug; Coquillé, Nathalie; Le Floch, Stephane; Geraudie, Perrine; Dussauze, Matthieu; Lemaire, Philippe; Camus, Lionel

    2016-04-01

    In the context of an oil spill accident and the following oil spill response, much attention is given to the use of dispersants. Dispersants are used to disperse an oil slick from the sea surface into the water column generating a cloud of dispersed oil droplets. The main consequence is an increasing of the sea water-oil interface which induces an increase of the oil biodegradation. Hence, the use of dispersants can be effective in preventing oiling of sensitive coastal environments. Also, in case of an oil blowout from the seabed, subsea injection of dispersants may offer some benefits compared to containment and recovery of the oil or in situ burning operation at the sea surface. However, biological effects of dispersed oil are poorly understood for deep-sea species. Most effects studies on dispersed oil and also other oil-related compounds have been focusing on more shallow water species. This is the first approach to assess the sensitivity of a macro-benthic deep-sea organism to dispersed oil. This paper describes a toxicity test which was performed on the macro-benthic deep-sea amphipod (Eurythenes gryllus) to determine the concentration causing lethality to 50% of test individuals (LC50) after an exposure to dispersed Brut Arabian Light (BAL) oil. The LC50 (24 h) was 101 and 24 mg L(-1) after 72 h and 12 mg L(-1) at 96 h. Based on EPA scale of toxicity categories to aquatic organisms, an LC50 (96 h) of 12 mg L(-1) indicates that the dispersed oil was slightly to moderately toxic to E. gryllus. As an attempt to compare our results to others, a literature study was performed. Due to limited amount of data available for dispersed oil and amphipods, information on other crustacean species and other oil-related compounds was also collected. Only one study on dispersed oil and amphipods was found, the LC50 value in this study was similar to the LC50 value of E. gryllus in our study. Since toxicity data are important input to risk assessment and net environmental

  18. Crystal structure of a blue laccase from Lentinus tigrinus: evidences for intermediates in the molecular oxygen reductive splitting by multicopper oxidases

    PubMed Central

    Ferraroni, Marta; Myasoedova, Nina M; Schmatchenko, Vadim; Leontievsky, Alexey A; Golovleva, Ludmila A; Scozzafava, Andrea; Briganti, Fabrizio

    2007-01-01

    Background Laccases belong to multicopper oxidases, a widespread class of enzymes implicated in many oxidative functions in pathogenesis, immunogenesis and morphogenesis of organisms and in the metabolic turnover of complex organic substances. They catalyze the coupling between the four one-electron oxidations of a broad range of substrates with the four-electron reduction of dioxygen to water. These catalytic processes are made possible by the contemporaneous presence of at least four copper ion sites, classified according to their spectroscopic properties: one type 1 (T1) site where the electrons from the reducing substrates are accepted, one type 2 (T2), and a coupled binuclear type 3 pair (T3) which are assembled in a T2/T3 trinuclear cluster where the electrons are transferred to perform the O2 reduction to H2O. Results The structure of a laccase from the white-rot fungus Lentinus (Panus) tigrinus, a glycoenzyme involved in lignin biodegradation, was solved at 1.5 Å. It reveals a asymmetric unit containing two laccase molecules (A and B). The progressive reduction of the copper ions centers obtained by the long-term exposure of the crystals to the high-intensity X-ray synchrotron beam radiation under aerobic conditions and high pH allowed us to detect two sequential intermediates in the molecular oxygen reduction pathway: the "peroxide" and the "native" intermediates, previously hypothesized through spectroscopic, kinetic and molecular mechanics studies. Specifically the electron-density maps revealed the presence of an end-on bridging, μ-η1:η1 peroxide ion between the two T3 coppers in molecule B, result of a two-electrons reduction, whereas in molecule A an oxo ion bridging the three coppers of the T2/T3 cluster (μ3-oxo bridge) together with an hydroxide ion externally bridging the two T3 copper ions, products of the four-electrons reduction of molecular oxygen, were best modelled. Conclusion This is the first structure of a multicopper oxidase which

  19. Effects of current-use fungicides and their mixtures on the feeding and survival of the key shredder Gammarus fossarum.

    PubMed

    Zubrod, J P; Baudy, P; Schulz, R; Bundschuh, M

    2014-05-01

    Fungicides are frequently applied in agriculture and are subsequently detected in surface waters in total concentrations of up to several tens of micrograms per liter. These concentrations imply potential effects on aquatic communities and fundamental ecosystem functions such as leaf litter breakdown. In this context, the present study investigates sublethal and lethal effects of organic (azoxystrobin, carbendazim, cyprodinil, quinoxyfen, and tebuconazole) and inorganic (three copper (Cu)-based substances and sulfur) current-use fungicides and their mixtures on the key leaf-shredding invertebrate Gammarus fossarum. The feeding activity of fungicide-exposed gammarids was quantified as sublethal endpoint using a static (organic fungicides; 7 d test duration) or a semi-static (inorganic fungicides; 6 d test duration with a water exchange after 3 d) approach (n=30). EC50-values of organic fungicides were generally observed at concentrations resulting in less than 20% mortality, with the exception of carbendazim. With regard to feeding, quinoxyfen was the most toxic organic fungicide, followed by cyprodinil, carbendazim, azoxystrobin, and tebuconazole. Although all tested organic fungicides have dissimilar (intended) modes of action, a mixture experiment revealed a synergistic effect on gammarids' feeding at high concentrations when using "independent action" as the reference model (∼35% deviation between predicted and observed effect). This may be explained by the presence of a synergizing azole fungicide (i.e. tebuconazole) in this mixture. Furthermore, lethal concentrations of all Cu-based fungicides assessed in this study were comparable amongst one another. However, they differed markedly in their effective concentrations when using feeding activity as the endpoint, with Cu-sulfate being most toxic, followed by Cu-hydroxide and Cu-octanoate. In contrast, sulfur neither affected survival nor the feeding activity of gammarids (up to ∼5 mg/L) but reduced Cu

  20. Acanthocephalan parasites: help or burden in gammarid amphipods exposed to cadmium?

    PubMed

    Gismondi, E; Cossu-Leguille, C; Beisel, J-N

    2012-05-01

    We investigated the influence of the acanthocephalan parasite Polymorphus minutus on the mortality of its intermediate host, Gammarus roeseli, exposed to cadmium, by the measure of LC(50-96h) values as well as the bioaccumulation of cadmium both in the host and in its parasite. LC(50) results revealed that infected G. roeseli males died less under cadmium stress than uninfected ones; while the converse has been observed in females. Cadmium resistance of infected males could be explained by a weaker bioconcentration factor (BCF) than in females. The lower BCF in infected individuals was closely related with an uptake of cadmium by P. minutus in its host. Nevertheless, although infected females had both weaker BCF and cadmium concentration in their body, the presence of P. minutus did not induce lower mortality than uninfected females. On the contrary, their sensitivity to cadmium was increased by the presence of P. minutus. We discuss the hypothesis that differences of mortality between uninfected and infected gammarids could be explained by a difference of cadmium bioconcentration in host, and by the cadmium bioaccumulation in the parasite. Indeed, results suggested that P. minutus could help G. roeseli to face with stress, what contributed to keep the host alive and favour the parasite transmission. PMID:22461071

  1. Distribution and behavior of scavenging amphipods from the central North Pacific

    NASA Astrophysics Data System (ADS)

    Ingram, Camilla L.; Hessler, Robert R.

    1983-07-01

    Deep-sea scavenging amphipod distributions, abundance, and behavior were studied with five-vehicle baited traps. The species composition and numerical abundances were comparable in the areas sampled. All size classes of the four predominant species ( Paralicella caperesca, P. tenuipes, Orchomene gerulicorbis, and Eurythenes gryllus) were trapped including sexually mature individuals, but no females were ovigerous. The central North Pacific E. gryllus is morphologically distinct from Atlantic E. gryllus and may represent a different species. Pelagic and demersal amphipod guilds exist, as determined by body size and vertical and horizontal distributional patterns. The demersal guild is composed of P. caperesca, P. tenuipes, and O. gerulicorbis, all of which are <2 cm in total body length and occur within 1 m of the sediment. E. gryllus, the only representative of the pelagic guild, ranges between 1.7 and 14 cm in total body length and has its greatest abundance several to tens of meters above the sediment. Members of the demersal guild probably can detect and exploit both large and small food falls or autochthonous organic particles because of their proximity to the sediment. They reside within the area of the benthic boundary layer where currents are slowest, and the diffusion of odor is slower than higher in the water column, thus reducing the area from which they can be attracted to a food item. The vertical distribution of E. gryllus correlates well with several physical features of the benthic boundary layer. Their vertical abundance increases an order of magnitude near the top of the Ekman layer, correlating with the increase in current velocities. It continues to increase up to 20 m, corresponding with the probable vertical extent of more than two-thirds of an odor trace. Their abundance decreases significantly above 20 m. The above correlations imply that the vertical distribution of E. gryllus is an adaptation that provides a wide chemosensory overview of

  2. Milbemycin oxime (Interceptor) treatment of amphipod parasites (Hyperiidae) from several host jellyfish species.

    PubMed

    Boonstra, Jennifer L; Koneval, Maureen E; Clark, James D; Schick, Mark; Smith, Malissa; Stark, Amy L

    2015-03-01

    Wild-caught crystal jellyfish (Aequorea victoria) arrived at the John G. Shedd Aquarium infested with hyperiid amphipods (Hyperia medusarum), which were inadvertently introduced into a system containing several jellyfish species. Affected systems were treated with milbemycin oxime (Interceptor tablets for dogs 51-100 lbs, Novartis Animal Health US, Inc., Greensboro, North Carolina 27408, USA), a treatment prescribed for red bug (Tegastes acroporanus) infestation in corals. Two treatments using one 25-mg aliquot of Interceptor per 10 gallons of tank water administered 6-7 days apart were completed. Overall, treatment to eradicate the parasite from the affected systems was successful. Further studies evaluating the tolerance of jellyfish to milbemycin oxime, particularly in small juvenile Eutonina indicans and Aurelia aurita, are warranted. Based on clinical observations, there were more negative effects associated with the treatment in the hydrozoans than in the scyphozoans. PMID:25831592

  3. A simple control for sediment-toxicity exposures using the amphipod, Hyalella azteca

    USGS Publications Warehouse

    Lasier, Pete; Urich, Matthew L.

    2014-01-01

    Sediment-toxicity exposures comparing survival and growth of the freshwater amphipod, Hyalella azteca, are often components of aquatic-habitat assessments. Standardized exposure methods have been established and require evaluations for quality assurance. Test acceptability using performance-based criteria can be determined from exposures to control sediments, which are collected from the environment or formulated from commercially available components. Amending sand with leached alfalfa solids provided a simple formulated sediment that elicited consistently acceptable survival and growth in 28-day exposures with and without a daily feeding regime. A procedure is described for preparing the sediment along with results from comparisons among sand, amended sand, and field-collected sediments that incorporated three feeding regimes.

  4. Effects of temperature and salinity on the development of the amphipod crustacean Eogammarus sinensis

    NASA Astrophysics Data System (ADS)

    Xue, Suyan; Fang, Jianguang; Zhang, Jihong; Jiang, Zengjie; Mao, Yuze; Zhao, Fazhen

    2013-09-01

    The amphipod crustacean Eogammarus sinensis has useful features that make it suitable for use in the aquaculture of fish and large decapod crustaceans. In this study, we investigated the effects of temperature and salinity on the development, fecundity, survival, and growth rate of E. sinensis. The results show that temperature significantly affected E. sinensis development, but salinity. As temperature increased, the duration of E. sinensis embryonic development decreased. Fecundity was affected significantly by temperature and the combination of temperature and salinity, but by salinity alone. In addition, high temperatures accelerated E. sinensis juvenile growth rates, whereas high salinity reduced it. Therefore, our data suggest that E. sinensis tolerates a wide range of salinities and that temperature has more significant effects than salinity on the embryonic development, fecundity, and growth of E. sinensis. Our results shall be useful for mass production of this species for use in aquaculture.

  5. Contribution of aqueous and dietary uptakes to lead (Pb) bioaccumulation in Gammarus pulex: From multipathway modeling to in situ validation.

    PubMed

    Hadji, Rym; Urien, Nastassia; Uher, Emmanuelle; Fechner, Lise C; Lebrun, Jérémie D

    2016-07-01

    Although dynamic approaches are nowadays used increasingly to describe metal bioaccumulation in aquatic organisms, the validation of such laboratory-derived modeling is rarely assessed under environmental conditions. Furthermore, information on bioaccumulation kinetics of Pb and the significance of its uptake by dietary route is scarce in freshwater species. This study aims at modeling aqueous and dietary uptakes of Pb in the litter-degrader Gammarus pulex and assessing the predictive quality of multipathway modeling from in situ bioaccumulation data. In microcosms, G. pulex were exposed to environmentally realistic concentrations of Pb (from 0.1 to 10µg/L) in the presence of Pb-contaminated poplar leaves, which were enclosed or not in a net to distinguish aqueous and dietary uptakes. Results show that water and food both constitute contamination sources for gammarids. Establishing biodynamic parameters involved in Pb aqueous and dietary uptake and elimination rates enabled to construct a multipathway model to describe Pb bioaccumulation in gammarids. This laboratory-derived model successfully predicted bioaccumulation measured in native populations of G. pulex collected in situ when local litter was used as dietary exposure source. This study demonstrates not only the suitable applicability of biodynamic parameters for predicting Pb bioaccumulation but also the necessity of taking dietary uptake into account for a better interpretation of the gammarids' contamination in natural conditions. PMID:27057993

  6. Investigation of the soluble metals in tissue as biological response pattern to environmental pollutants (Gammarus fossarum example).

    PubMed

    Filipović Marijić, Vlatka; Dragun, Zrinka; Sertić Perić, Mirela; Matoničkin Kepčija, Renata; Gulin, Vesna; Velki, Mirna; Ečimović, Sandra; Hackenberger, Branimir K; Erk, Marijana

    2016-07-01

    In the present study, Gammarus fossarum was used to investigate the bioaccumulation and toxic effects of aquatic pollutants in the real environmental conditions. The novelty of the study is the evaluation of soluble tissue metal concentrations in gammarids as indicators in early assessment of metal exposure. In the Sutla River, industrially/rurally/agriculturally influenced catchment in North-Western Croatia, physico-chemical water properties pointed to disturbed ecological status, which was reflected on population scale as more than 50 times lower gammarid density compared to the reference location, Črnomerec Stream. Significantly higher levels of soluble toxic metals (Al, As, Cd, Pb, Sb, Sn, Sr) were observed in gammarids from the Sutla River compared to the reference site and reflected the data on higher total dissolved metal levels in the river water at that site. The soluble metal estimates were supplemented with the common multibiomarker approach, which showed significant biological responses for decreased acetylcholinesterase activity and increased total soluble protein concentrations, confirming stressed environmental conditions for biota in the Sutla River. Biomarker of metal exposure, metallothionein, was not induced and therefore, toxic effect of metals was not confirmed on molecular level. Comparable between-site pattern of soluble toxic metals in gammarids and total dissolved metal levels in water suggests that prior to biomarker response and observed toxic impact, soluble metals in tissue might be used as early warning signs of metal impact in the aquatic environment and improve the assessment of water quality. PMID:27060638

  7. An Enriched Environment Promotes Shelter-Seeking Behaviour and Survival of Hatchery-Produced Juvenile European Lobster (Homarus gammarus)

    PubMed Central

    Aspaas, Stian; Grefsrud, Ellen Sofie; Fernö, Anders; Jensen, Knut Helge; Trengereid, Henrik; Agnalt, Ann-Lisbeth

    2016-01-01

    The high loss of newly released hatchery-reared European lobster (Homarus gammarus) juveniles for stock enhancement is believed to be the result of maladaptive anti-predator behaviour connected to deprived stimuli in the hatchery environment. Our objective was to learn if an enriched hatchery environment enhances shelter-seeking behaviour and survival. In the “naïve” treatment, the juveniles were raised in single compartments without substrate and shelter whereas juveniles in the “exposed” treatment experienced substrate, shelter and interactions with conspecifics. Three experiments with increasing complexity were conducted. Few differences in shelter-seeking behaviour were found between treatments when one naïve or one exposed juvenile were observed alone. When observing interactions between one naïve and one exposed juvenile competing for shelter, naïve juveniles more often initiated the first aggressive encounter. The third experiment was set up to simulate a release for stock enhancement. Naïve and exposed juveniles were introduced to a semi-natural environment including substrate, a limited number of shelters and interactions with conspecifics. Shelter occupancy was recorded three times during a period of 35 days. Exposed juveniles occupied more shelters, grew larger and had higher survival compared with naïve juveniles. Our results demonstrate that experience of environmental complexity and social interactions increase shelter-seeking ability and survival in hatchery reared lobster juveniles. PMID:27560932

  8. An Enriched Environment Promotes Shelter-Seeking Behaviour and Survival of Hatchery-Produced Juvenile European Lobster (Homarus gammarus).

    PubMed

    Aspaas, Stian; Grefsrud, Ellen Sofie; Fernö, Anders; Jensen, Knut Helge; Trengereid, Henrik; Agnalt, Ann-Lisbeth

    2016-01-01

    The high loss of newly released hatchery-reared European lobster (Homarus gammarus) juveniles for stock enhancement is believed to be the result of maladaptive anti-predator behaviour connected to deprived stimuli in the hatchery environment. Our objective was to learn if an enriched hatchery environment enhances shelter-seeking behaviour and survival. In the "naïve" treatment, the juveniles were raised in single compartments without substrate and shelter whereas juveniles in the "exposed" treatment experienced substrate, shelter and interactions with conspecifics. Three experiments with increasing complexity were conducted. Few differences in shelter-seeking behaviour were found between treatments when one naïve or one exposed juvenile were observed alone. When observing interactions between one naïve and one exposed juvenile competing for shelter, naïve juveniles more often initiated the first aggressive encounter. The third experiment was set up to simulate a release for stock enhancement. Naïve and exposed juveniles were introduced to a semi-natural environment including substrate, a limited number of shelters and interactions with conspecifics. Shelter occupancy was recorded three times during a period of 35 days. Exposed juveniles occupied more shelters, grew larger and had higher survival compared with naïve juveniles. Our results demonstrate that experience of environmental complexity and social interactions increase shelter-seeking ability and survival in hatchery reared lobster juveniles. PMID:27560932

  9. Does the acanthocephalan parasite Polymorphus minutus modify the energy reserves and antitoxic defences of its intermediate host Gammarus roeseli?

    PubMed

    Gismondi, E; Cossu-Leguille, C; Beisel, J-N

    2012-07-01

    In disturbed environments, infected organisms have to face both parasitic and chemical stresses. Although this situation is common, few studies have been devoted to the effects of infection on hosts' energy reserves and antitoxic defence capacities, while parasite survival depends on host survival. In this study, we tested the consequences of an infection by Polymorphus minutus on the energy reserves (protein, lipid and glycogen) and antioxidant defence capacities (reduced glutathione, γ-glutamylcysteine ligase activity) of Gammarus roeseli males and females, in the absence of chemical stress. Moreover, malondialdehyde concentration was used as a toxicity biomarker. The results revealed that in infected G. roeseli, whatever their gender and the sampling month, protein and lipid contents were lower, but glycogen contents were higher. This could be explained by the fact that the parasite diverts part of the host's energy for its own development. Moreover, glutathione concentrations and γ-glutamylcysteine ligase activity were both lower, which could lead to lower antitoxic defence in the host. These results suggest negative effects on individuals in the case of additional stress (e.g. pollutant exposure). In the absence of chemical stress, the lower malondialdehyde level in infected gammarids could imply a probable protective effect of the parasite. PMID:22405348

  10. Consequences of Lower Food Intake on the Digestive Enzymes Activities, the Energy Reserves and the Reproductive Outcome in Gammarus fossarum

    PubMed Central

    Charron, Laetitia; Geffard, Olivier; Chaumot, Arnaud; Coulaud, Romain; Jaffal, Ali; Gaillet, Véronique; Dedourge-Geffard, Odile; Geffard, Alain

    2015-01-01

    Digestive enzyme activity is often used as a sensitive response to environmental pollution. However, only little is known about the negative effects of stress on digestive capacities and their consequences on energy reserves and reproduction, although these parameters are important for the maintenance of populations. To highlight if changes in biochemical responses (digestive enzymes and reserves) led to impairments at an individual level (fertility), Gammarus fossarum were submitted to a lower food intake throughout a complete female reproductive cycle (i.e. from ovogenesis to offspring production). For both males and females, amylase activity was inhibited by the diet stress, whereas trypsin activity was not influenced. These results underline similar sensitivity of males and females concerning their digestive capacity. Energy reserves decreased with food starvation in females, and remained stable in males. The number of embryos per female decreased with food starvation. Lower digestive activity in males and females therefore appears as an early response. These results underline the ecological relevance of digestive markers, as they make it possible to anticipate upcoming consequences on reproduction in females, a key biological variable for population dynamics. PMID:25880985

  11. A new family, genus and species of freshwater amphipod Australomicroprotopus megacoxa gen. nov. sp. nov. (Senticaudata, Corophiidea, Microprotopoidea, Australomicroprotopidae fam. nov.) from Australia.

    PubMed

    Myers, Alan A; Lowry, James K; Billingham, Zac

    2016-01-01

    A new species of fresh-water amphipod is described from Australia. Australomicroprotopus megacoxa gen. nov. sp. nov. It is placed in a new family, the Australomicroprotopidae fam. nov. and is fully described and figured. PMID:27615940

  12. 454 pyrosequencing-based analysis of gene expression profiles in the amphipod Melita plumulosa: transcriptome assembly and toxicant induced changes.

    PubMed

    Hook, Sharon E; Twine, Natalie A; Simpson, Stuart L; Spadaro, David A; Moncuquet, Philippe; Wilkins, Marc R

    2014-08-01

    Next generation sequencing using Roche's 454 pyrosequencing platform can be used to generate genomic information for non-model organisms, although there are bioinformatic challenges associated with these studies. These challenges are compounded by a lack of a standardized protocol to either assemble data or to evaluate the quality of a de novo transcriptome. This study presents an assembly of the control and toxicant responsive transcriptome of Melita plumulosa, an Australian amphipod commonly used in ecotoxicological studies. RNA was harvested from control amphipods, juvenile amphipods, and from amphipods exposed to either metal or diesel contaminated sediments. This RNA was used as the basis for a 454 based transcriptome sequencing effort. Sequencing generated 1.3 million reads from control, juvenile, metal-exposed and diesel-exposed amphipods. Different read filtering and assembly protocols were evaluated to generate an assembly that (i) had an optimal number of contigs; (ii) had long contigs; (iii) contained a suitable representation of conserved genes; and (iv) had long ortholog alignment lengths relative to the length of each contig. A final assembly, generated using fixed-length trimming based on the sequence quality scores, followed by assembly using the MIRA algorithm, produced the best results. The 26,625 contigs generated via this approach were annotated using Blast2GO, and the differential expression between treatments and control was determined by mapping with BWA followed by DESeq. Although the mapping generated low coverage, many differentially expressed contigs, including some with known developmental or toxicological function, were identified. This study demonstrated that 454 pyrosequencing is an effective means of generating reference transcriptome information for organisms, such as the amphipod M. plumulosa, that have no genomic information available in databases or in closely related sequenced species. It also demonstrated how optimization of

  13. Effects of the boscalid fungicide Filan® on the marine amphipod Allorchestes compressa at environmentally relevant concentrations.

    PubMed

    Vu, Hung T; Keough, Michael J; Long, Sara M; Pettigrove, Vincent J

    2016-05-01

    Fungicides are widely used in agriculture to control fungal diseases. After application, fungicides can be transported offsite to surface and groundwater and ultimately enter estuarine and marine environments. The presence of fungicides in the marine environment may pose risks to marine organisms, but little is known about fungicide effects on these organisms, especially invertebrates. The present study investigated the effects of the commonly used boscalid fungicide Filan® on life history traits, feeding rate, and energy reserves (lipid, glycogen, and protein content) of the marine amphipod Allorchestes compressa over 6 wk under laboratory conditions. Amphipods were exposed to 3 concentrations of Filan (1 μg, 10 μg, and 40 μg active ingredient [a.i.]/L), with 5 replicates per treatment. Lipid content and reproduction were the most sensitive measures of effect, with lipid content reduced by 53.8% at the highest concentration. Survival, growth, and other energy reserves of amphipods were also negatively affected by Filan, and the effects were concentration dependent. Antennal deformities were incidentally observed on the amphipods at a concentration of 40 μg a.i./L. The results of the present study indicate comprehensive effects of the boscalid fungicide Filan on A. compressa at environmentally relevant concentrations. The decline or absence of A. compressa in marine ecosystems could impair the ecosystem function because of their important role in trophic transfer and nutrient recycling. The authors' results suggest that even though the use of fungicides is often regarded as posing only a minor risk to aquatic organisms, the assessment of their long-term effects is critical. Environ Toxicol Chem 2016;35:1130-1137. © 2015 SETAC. PMID:26378894

  14. Evaluation of ability of reference toxicity tests to identify stress in laboratory populations of the amphipod Hyalella azteca

    USGS Publications Warehouse

    McNulty, E.W.; Dwyer, F.J.; Ellersieck, Mark R.; Greer, E.I.; Ingersoll, C.G.; Rabeni, C.F.

    1999-01-01

    Standard methods for conducting toxicity tests imply that the condition of test organisms can be established using reference toxicity tests. However, only a limited number of studies have evaluated whether reference toxicity tests can actually be used to determine if organisms are in good condition at the start of a test. We evaluated the ability of reference toxicants to identify stress associated with starvation in laboratory populations of the amphipod Hyalella azteca using acute toxicity tests and four reference toxicants: KCl, CdCl2, sodium pentachlorophenate (NaPCP), and carbaryl. Stress associated with severe starvation was observed with exposure of amphipods to carbaryl or NaPCP but not with exposure to KCl or CdCl2 (i.e., lower LC50 with severe starvation). Although the LC50s for NaPCP and carbaryl were statistically different between starved and fed amphipods, this difference may not be biologically significant given the variability expected in acute lethality tests. Stress associated with sieving, heat shock, or cold shock of amphipods before the start of a test was not evident with exposure to carbaryl or KCl as reference toxicants. The chemicals evaluated in this study provided minimal information about the condition of the organisms used to start a toxicity test. Laboratories should periodically perform reference toxicity tests to assess the sensitivity of life stages or strains of test organisms. However, use of other test acceptability criteria required in standard methods such as minimum survival, growth, or reproduction of organisms in the control treatment at the end of a test, provides more useful information about the condition of organisms used to start a test compared to data generated from reference toxicity tests.

  15. A method for eradicating amphipod parasites (hyperiidae) from host jellyfish, Chrysaora fuscescens (Brandt, 1835), in a closed recirculating system.

    PubMed

    Crossley, Sharyl M G; George, Anna L; Keller, Christian J

    2009-03-01

    On 2 December 2006, a heavy infestation of the parasitic hyperiid amphipods Hyperia medusarum and Lestrigonus shoemakeri was discovered in the sea nettles (Chrysaora fuscescens) exhibit at the Tennessee Aquarium. Pretreatment trials that exposed moon jellyfish (Aurelia aurita) and sea nettles to therapeutic levels of diflubenzuron confirmed that the treatment would be tolerated by these species of jellyfish. The exhibit tank was dosed with a 0.03 mg/L concentration of diflubenzuron for 7 days, after which the medication was removed by filtration. An arbitrarily chosen subset from the sea nettle exhibit was sampled regularly over the next 8 wk to monitor the parasite population. The average number of amphipods per jellyfish sampled decreased throughout the treatment and sampling period. No live amphipods were observed 6 wk after the start of treatment, and no negative side effects were observed in the sea nettles. The use of diflubenzuron to eradicate hyperiid parasites from scyphomedusae is a safe and useful option when properly applied in a controlled environment. PMID:19368258

  16. Sex-specific nutrient use and preferential allocation of resources to a sexually selected trait in Hyalella amphipods.

    PubMed

    Goos, Jared M; Cothran, Rickey D; Jeyasingh, Punidan D

    2016-03-01

    Although sexually dimorphic traits are often well studied, we know little about sex-specific resource use strategies that should underlie such dimorphism. We measured sex-specific responses in acquisition and assimilation of two fundamental resources, carbon (C) and phosphorus (P) in juvenile and mature Hyalella amphipods given low and high supplies of inorganic phosphate, analogous to oligotrophic and eutrophic conditions, respectively. Additionally, we quantified allocation of resources to sexual traits in males. Dual radiotracer ((14)C and (33)P) assays revealed substantial age- and sex-specific differences in acquisition and assimilation. Furthermore, a phenotypic manipulation experiment revealed that amphipods fed low-P food allocated more C to all traits than those fed high-P food. Importantly, we found that amphipods preferentially allocated more C to the development of a sexually selected trait (the posterior gnathopod), compared with a serially homologous trait (the fifth pereopod) not under sexual selection. Substantial differences in how the sexes use fundamental resources, and the impact of altered nutrient supply on such differences, illuminate sexual dimorphism at the lowest level of biological organization. Such information will be important in understanding how sex- and age-specific life history demands influence nutrient processing in a biosphere characterized by rapidly changing alterations to biogeochemical cycles. PMID:26747910

  17. Specific antioxidant reactions to oxidative stress promoted by natural organic matter in two amphipod species from Lake Baikal.

    PubMed

    Timofeyev, Maxim A; Shatilina, Zhanna M; Kolesnichenko, Aleksey V; Kolesnichenko, Viktoria V; Steinberg, Christian E W

    2006-04-01

    Aquatic organisms are exposed to a variety of natural chemical stressors such as humic substances. The aim of this study was to investigate the mode of action of natural organic matter (NOM, roughly 80% of which is humic substances) on two freshwater amphipods from Lake Baikal, Eulimnogammarus verrucosus (Gerstf.) and Eulimnogammarus cyaneus (Dyb.), in order to assess the potential oxidative stress of NOM impact. Chosen as oxidative stress markers were lipid peroxidation and cell internal hydrogen peroxide level as well as peroxidase, catalase, and glutathione S-transferase activities. Exposure of amphipods to NOM caused a significant increase in lipid peroxidation but a concomitant decrease in hydrogen peroxide concentration, and peroxidase and (to a lesser degree) glutathione S-transferase activities. An interim increase of catalase activity was observed. A possible reason for the decrease in major antioxidant enzyme activity is exhaustion of the reservoir of reduced substrates in the first stage of the antioxidant defense reaction. Despite the inhibition of major antioxidant enzymes, the studied amphipods were able to successfully resist the NOM oxidative impact and, at low NOM concentrations, to combat lipid peroxidation processes. PMID:16528684

  18. Comparison between amphipod assemblages associated with Caulerpa racemosa var. cylindracea and those of other Mediterranean habitats on soft substrate

    NASA Astrophysics Data System (ADS)

    Vázquez-Luis, Maite; Sanchez-Jerez, Pablo; Bayle-Sempere, Just T.

    2009-09-01

    The spread of the invasive alga Caulerpa racemosa var. cylindracea in shallow-water habitats can present different faunal assemblage composition. We compared the amphipod assemblages associated with C. racemosa and natural habitats found on shallow-water Mediterranean soft substrata. Four vegetated habitats were compared: C. racemosa, Caulerpa prolifera, Cymodocea nodosa and Posidonia oceanica with unvegetated substrata. Samples were collected during two sampling periods (September 2004 and March 2005). A total of 63 amphipod species were recorded. The results showed that the vegetated habitats sampled, including C. racemosa stands, supported a higher abundance and species richness of amphipods. Furthermore, the assemblage structure differed between the different habitats, while the abundance of some species was significantly different, depending on habitat. For example, Microdeutopus obtusatus was favoured by C. racemosa habitat; Ampelisca diadema was associated with C. prolifera beds; and Hyale schmidti was more abundant in P. oceanica meadows. Habitat invasion by C. racemosa can exert an important influence on biotic assemblages, modifying habitat structure and associated fauna.

  19. Bioavailability of particle-associated silver, cadmium, and zinc to the estuarine amphipod Leptocheirus plumulosus through dietary ingestion

    USGS Publications Warehouse

    Schlekat, C.E.; Decho, Alan W.; Chandler, G.T.

    2000-01-01

    We conducted experiments to determine effects of particle type on assimilatory metal bioavailability to Leptocheirus plumulosus, an infaunal, estuarine amphipod that is commonly used in sediment toxicity tests. The following particles were used to represent natural food items encountered by this surface-deposit and suspension-feeding amphipod: bacterial exopolymeric sediment coatings, polymeric coatings made from Spartina alterniflora extract, amorphous iron oxide coatings, the diatom Phaeodactylum tricornutum, the chlorophyte Dunaliella tertiolecta, processed estuarine sediment, and fresh estuarine sediment. Bioavailability of the gamma-emitting radioisotopes 110mAg, 109Cd, and 65Zn was measured as the efficiency with which L. plumulosus assimilated metals from particles using pulse-chase methods. Ag and Cd assimilation efficiencies were highest from bacterial exopolymeric coatings. Zn assimilation efficiency exhibited considerable interexperimental variation; the highest Zn assimilation efficiencies were measured from phytoplankton and processed sediment. In general, Ag and Cd assimilation efficiencies from phytoplankton were low and not related to the proportion of metal associated with cell cytosol or cytoplasm, a phenomenon reported for other particle-ingesting invertebrates. Amphipod digestive processes explain differences in Ag and Cd assimilation efficiencies between exopolymeric coatings and phytoplankton. Results highlight the importance of labile polymeric organic carbon sediment coatings in dietary metals uptake by this benthic invertebrate, rather than recalcitrant organic carbon, mineralogical features such as iron oxides, or phytoplankton.

  20. Patterns of population genetic variation in sympatric chiltoniid amphipods within a calcrete aquifer reveal a dynamic subterranean environment

    PubMed Central

    Bradford, T M; Adams, M; Guzik, M T; Humphreys, W F; Austin, A D; Cooper, S JB

    2013-01-01

    Calcrete aquifers from the Yilgarn region of arid central Western Australia contain an assemblage of obligate groundwater invertebrate species that are each endemic to single aquifers. Fine-scale phylogeographic and population genetic analyses of three sympatric and independently derived species of amphipod (Chiltoniidae) were carried out to determine whether there were common patterns of population genetic structure or evidence for past geographic isolation of populations within a single calcrete aquifer. Genetic diversity in amphipod mitochondrial DNA (cytochrome c oxidase subunit I gene) and allozymes were examined across a 3.5 km2 region of the Sturt Meadows calcrete, which contains a grid of 115 bore holes (=wells). Stygobiont amphipods were found to have high levels of mitochondrial haplotype diversity coupled with low nucleotide diversity. Mitochondrial phylogeographic structuring was found between haplogroups for one of the chiltoniid species, which also showed population structuring for nuclear markers. Signatures of population expansion in two of the three species, match previous findings for diving beetles at the same site, indicating that the system is dynamic. We propose isolation of populations in refugia within the calcrete, followed by expansion events, as the most likely source of intraspecific genetic diversity, due to changes in water level influencing gene flow across the calcrete. PMID:23549336

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

    SciTech Connect

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

    1998-05-01

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

  2. Behavioural and Physiological Responses of Gammarus pulex Exposed to Cadmium and Arsenate at Three Temperatures: Individual and Combined Effects

    PubMed Central

    Vellinger, Céline; Felten, Vincent; Sornom, Pascal; Rousselle, Philippe; Beisel, Jean-Nicolas; Usseglio-Polatera, Philippe

    2012-01-01

    This study aimed at investigating both the individual and combined effects of cadmium (Cd) and arsenate (AsV) on the physiology and behaviour of the Crustacean Gammarus pulex at three temperatures (5, 10 and15°C). G. pulex was exposed during 96 h to (i) two [Cd] alone, (ii) two [AsV] alone, and (iii) four combinations of [Cd] and [AsV] to obtain a complete factorial plane. After exposure, survival, [AsV] or [Cd] in body tissues, behavioural (ventilatory and locomotor activities) and physiological responses (iono-regulation of [Na+] and [Cl−] in haemolymph) were examined. The interactive effects (antagonistic, additive or synergistic) of binary mixtures were evaluated for each tested temperature using a predictive model for the theoretically expected interactive effect of chemicals. In single metal exposure, both the internal metal concentration in body tissues and the mortality rate increased along metallic gradient concentration. Cd alone significantly impaired both [Na+] and [Cl−] while AsV alone had a weak impact only on [Cl−]. The behavioural responses of G. pulex declined with increasing metal concentration suggesting a reallocation of energy from behavioural responses to maintenance functions. The interaction between AsV and Cd was considered as ‘additive’ for all the tested binary mixtures and temperatures (except for the lowest combination at 10°C considered as “antagonistic”). In binary mixtures, the decrease in both ventilatory and locomotor activities and the decline in haemolymphatic [Cl−] were amplified when respectively compared to those observed with the same concentrations of AsV or Cd alone. However, the presence of AsV decreased the haemolymphatic [Na+] loss when G. pulex was exposed to the lowest Cd concentration. Finally, the observed physiological and behavioural effects (except ventilation) in G. pulex exposed to AsV and/or Cd were exacerbated under the highest temperature. The discussion encompasses both the toxicity

  3. Bioaccumulation of Toxoplasma and Cryptosporidium by the freshwater crustacean Gammarus fossarum: Involvement in biomonitoring surveys and trophic transfer.

    PubMed

    Bigot-Clivot, Aurélie; Palos Ladeiro, Mélissa; Lepoutre, Alexandra; Bastien, Fanny; Bonnard, Isabelle; Dubey, Jitender P; Villena, Isabelle; Aubert, Dominique; Geffard, Olivier; François, Adeline; Geffard, Alain

    2016-11-01

    The protozoa Toxoplasma gondii and Cryptosporidium parvum are public health priorities because their oocysts can persist in recreational, surface, drinking, river, and sea water sources for a long time. To evaluate the capacity of the freshwater crustacean Gammarus fossarum to accumulate T. gondii and C. parvum oocysts, gammarids were exposed to 200, 2000 or 20,000 oocysts per gammarid and per day for 21 days followed by 5 days of depuration. C. parvum DNA was detected by qPCR in G. fossarum in only one out of four pools for the highest concentration and after 14 days of exposure, and T. gondii DNA was detected after 7 days of exposure to the two highest concentrations. Our results document the capacity of G. fossarum to accumulate T. gondii in its tissues proportionally to the ambient concentration; the maximum number of oocysts was detected in gammarid tissues after exposure to 20,000 oocysts per day. Mean values of 3.26 (±3), 21.71 (±15.18), and 17.41 (±10.89) oocysts were detected in gammarids after 7, 14, and 21 days, respectively, and after 5 days of depuration, T. gondii oocysts were still present in gammarid tissues. These results show for the first time that a freshwater crustacean can bioaccumulate T. gondii oocysts, suggesting that G. fossarum is a potential effective bioindicator of protozoan contamination in biomonitoring studies. Moreover, due to its key position in freshwater food webs, G. fossarum could also play a role in the trophic transfer of protozoa. PMID:27454203

  4. Effects of sediment bioturbation by the estuarine amphipod Corophium volutator on fluoranthene resuspension and transfer into the mussel (Mytilus edulis)

    SciTech Connect

    Ciarelli, S.; Straalen, N.M. van; Klap, V.A.; Wezel, A.P. van

    1999-02-01

    To better understand the effects of bioturbation on partitioning and availability of sediment-bound contaminants to infaunal amphipods and mussels, experiments were carried out with fluoranthene-spiked sediment. Treatments included different densities of the estuarine amphipod, Corophium volutator. Total suspended solids (TSS), particulate organic carbon/particulate organic matter (POC/POM) in overlying water, fluoranthene concentrations in sediment, pore water, overlying water, amphipods, and mussels were measured. Bioturbation significantly increased TSS and POC/POM concentrations in overlying water, and this effect became greater at higher animal density and longer exposure time. Mean total aqueous fluoranthene concentrations increased from 2.40 to 4.1 and 5.45 {micro}g/L in the control, low-density, and high-density treatments, respectively, after 10 d of exposure. The particle-bound fraction of fluoranthene in the overlying water from the high-density treatment was two times higher than that from the low-density treatment. Bioturbation did not affect the partitioning of fluoranthene over suspended solids and water, nor did it affect the concentrations in sediment and pore water. This was illustrated by the constancy of sediment-interstitial water partitioning coefficients (log K{sub oc(iw)}), sediment-overlying water partitioning coefficients (log K{sub oc(ow)}), and normalized POC-water partitioning coefficients (log K{sub poc}). Uptake of fluoranthene by filter-feeding mussels (Mytilus edulis) increased linearly with the density of bioturbating amphipods and with exposure time. The difference in concentrations of fluoranthene in mussels between the lowest and highest density of amphipods was more than factor of two. Their results showed that bioturbation significantly increases TSS concentration in the overlying water and consequently the total aqueous concentration of sediment-bound contaminants, which are subsequently accumulated by filter-feeders. The

  5. Molecular evidence of the survival of subterranean amphipods (Arthropoda) during Ice Age underneath glaciers in Iceland.

    PubMed

    Kornobis, Etienne; Pálsson, Snaebjörn; Kristjánsson, Bjarni K; Svavarsson, Jörundur

    2010-06-01

    A Two endemic groundwater arthropod crustacean species, Crangonyx islandicus and Crymostygius thingvallensis, were recently discovered on the mid-Atlantic volcanic island of Iceland. The extent of morphological differences from closest relatives, endemism, along with the geographic isolation of Iceland and its complete coverage by glaciers 21,000 years ago, suggests that these two species have survived glaciation periods in sub-glacial refugia. Here we provide strong support for this hypothesis by an analysis of mitochondrial genetic variation within Crangonyx islandicus. Our results show that the species is divided into several distinct monophyletic groups that are found along the volcanic zone in Iceland, which have been separated by 0.5 to around 5 million years. The genetic divergence between groups reflects geographic distances between sampling sites, indicating that divergence occurred after the colonization of Iceland. The genetic patterns, as well as the dependency of genetic variation on distances from the tectonic plate boundary and altitude, points to recent expansion from several refugia within Iceland. This presents the first genetic evidence of multicellular organisms as complex as crustacean amphipods which have survived glaciations beneath an ice sheet. This survival may be explained by geothermal heat linked to volcanic activities, which may have maintained favourable habitats in fissures along the tectonic plate boundary in Iceland during glaciations. PMID:20465590

  6. Uptake, biotransformation, and elimination of benzo[a]pyrene by the gammarid amphipod, Leptocheirus plumulosus

    SciTech Connect

    Dickbut, R.M.; Huszai, C.M.; Lay, P.W.; Schaffner, L.C.

    1995-12-31

    The uptake, biotransformation, and elimination of {sup 3}H-benzo[a]pyrene (B[a]P) by the gammarid amphipod Leptocheirus plumulosus was evaluated in laboratory exposures. Rapid uptake (i.e. within 2.5 h) of sediment-associated B[a]P was observed, and during the exposures organism body burdens were dominated by organic extractable (e.g. parent compound) components, with aqueous soluble and bound metabolites constituting a much smaller fraction of the total body burden. However, upon discontinuation of exposure of the organisms to B[a]P, organic extractable compounds were more rapidly eliminated by L. plumulosus than the aqueous extractable and bound contaminant pools. Uptake and elimination of B[a]P were adequately modeled assuming first order kinetics, with the exception of the early stages of exposure. The rapid uptake during the first few hours of exposure of Leptocheirus to sediment-associated B[a]P may be due to sorption of B[a]P to the exoskeleton of the organism. This hypothesis is under further investigation. Uptake and elimination of B[a]P metabolite pools by L. plumulosus was best modeled assuming a fraction of the metabolite pool was irreversibly bound or slowly eliminated.

  7. Accumulation and toxicokinetics of fluoranthene in water-only exposures with freshwater amphipods

    SciTech Connect

    Driscoll, S.K.; Landrum, P.F.; Tigue, E.

    1997-04-01

    Two 10-d water-only toxicity tests with radiolabeled fluoranthene were conducted with two species of freshwater amphipods, Hyalella azteca and Diporeia sp. For H. azteca, 10-d median lethal concentrations were 564 nmol/L and 481 nmol/L. Tentative median lethal doses, determined from the regressions of body burden of remaining live H. azteca versus survival, were 5.6 and 3.6 mmol fluoranthene/kg wet weight tissue. Diporeia appeared to be less sensitive, because survival in Diporeia was greater than 84% after 10-d exposures. Elimination rates determined for Diporeia, ranging from 0.0011 to 0.0042/h were much slower than rates determined for H. azteca of 0.128 to 0.188/h. Faster elimination in H. azteca may be related to its greater ability to metabolize fluoranthene. For H. azteca, an average of 17% of its body burden was present as metabolites after 24 h of exposure to radiolabeled fluoranthene, as compared to 5% for Diporeia. For Diporeia, exposure to various water concentrations of fluoranthene for various lengths of time resulted in declines in the conditional uptake clearance rates. A similar, although less dramatic trend was observed for conditional uptake clearance rates in H. azteca.

  8. Sex-dependent effects of ultraviolet radiation on the marine amphipod Ampithoe valida (Ampithoidae).

    PubMed

    Valiñas, Macarena S; Helbling, E Walter

    2015-06-01

    The combined effects of solar radiation and diet on the marine amphipod Ampithoe valida were investigated exposing individuals to two solar radiation treatments: PAB (>280 nm, PAR+UV-A+UV-B) and P (>400 nm, only PAR), and three diets: poor (Ulva rigida) and rich (Porphyra columbina) in UV-absorbing compounds (UVAC), and mixed diet: (U. rigida+P. columbina). Females of A. valida showed higher food consumption rates when diets contained P. columbina, and preferred this macroalgae rather than U. rigida, resulting in a higher content of UVAC in their bodies. Moreover, the content of UVAC increased in the PAB treatment, thus suggesting the existence of a mechanism to accumulate these compounds under UVR. Although UVR affected the survival, the highest mortality rates were found in those females fed with poor-UVAC diets, which evidence that UVAC provided partial protection against UVR. Males preferred mixed diet, and did not show preference for any particular macroalgae. No differences in mortality were observed between radiation treatments, indicating that UVR did not affect the survival of males, independently if they accumulated UVAC or not. The vulnerability of females to UVR would be partially determined by the type of food consumed, which in turn would be closely related to the macroalgae composition of the intertidal they inhabiting. These effects could be even more pronounced under a global change scenario. PMID:25867457

  9. Incongruence between molecular phylogeny and morphological classification in amphipod crustaceans: a case study of Antarctic lysianassoids.

    PubMed

    Havermans, Charlotte; Nagy, Zoltán T; Sonet, Gontran; De Broyer, Claude; Martin, Patrick

    2010-04-01

    In Antarctic waters, the superfamily Lysianassoidea is one of the most important amphipod groups both in terms of species number and abundance. Dominant members of this superfamily are species of the orchomenid complex, found throughout the Southern Ocean. This study presents the first molecular phylogenetic analysis based on a representative subset of the Antarctic species belonging to different orchomenid genera and hence provides a framework for a systematic revision of these taxa. The current classification of the orchomenid genera is mainly based on mouthpart morphology. The validity of these morphological characters was assessed by resolving phylogenetic relationships using nuclear 28S rRNA and mitochondrial cytochrome oxidase subunit I sequences. The molecular data rejected most of the previously proposed taxonomic subdivisions within this complex. The genera Abyssorchomene and Orchomenella as well as the subgenus Orchomenopsis appeared to be non-monophyletic. This implies that the supposed diagnostic characters are likely a result of convergent evolution. Further, our results indicated the necessity of a revision of the family-level systematics. PMID:19857579

  10. Effects of predation and oxygen deficiency on different age classes of the amphipod Monoporeia affinis

    NASA Astrophysics Data System (ADS)

    Sandberg, E.; Bonsdorff, E.

    1996-06-01

    Predation by the big brackish-water isopod Saduria entomon on two age-classes (juveniles and adults) of the small deposit-feeding amphipod Monoporeia (syn. Pontoporeia) affinis was studied at different oxygen conditions (normoxia>11 mg/l O 2, and moderate hypoxia 4 mg/l O 2). Vulnerability of juvenile and adult M. affinis was studied in single and mixed age-class treatments. The proportions of juveniles and adults were varied at one total numerical density. The predatory effects were measured as numbers of individuals consumed and of total biomass intake (mg ash-free dry weight). The highest predation rate (in numbers) was detected in the single-prey treatment with juvenile M. affinis, both in normoxia and moderate hypoxia. No preference for any of the two size classes was found in the treatment with equal numbers of adults and juveniles. In normoxia, the total number of prey consumed decreased with increasing proportions of adults, while intake increased in terms of biomass. In moderate hypoxia, high proportions of adults reduced the predation rate of S. entomon to such an extent that also the intake in terms of biomass was significantly negatively affected.

  11. Assessing mechanisms of toxicant response in the amphipod Melita plumulosa through transcriptomic profiling.

    PubMed

    Hook, Sharon E; Osborn, Hannah L; Spadaro, David A; Simpson, Stuart L

    2014-01-01

    This study describes the function of transcripts with altered abundance in the epibenthic amphipod, Melita plumulosa, following whole-sediment exposure to a series of common environmental contaminants. M. plumulosa were exposed for 48 h to sediments spiked and equilibrated with the following contaminants at concentrations predicted to cause sublethal effects to reproduction: porewater ammonia 30 mg L(-1); bifenthrin at 100 μg kg(-1); fipronil at 50 μg kg(-1); 0.6% diesel; 0.3% crude oil; 250 mg Cu kg(-1); 400 mg Ni kg(-1); and 400 mg Zn kg(-1). RNA was extracted and hybridized against a custom Agilent microarray developed for this species. Although the microarray represented a partial transcriptome and not all features on the array could be annotated, unique transcriptomic profiles were generated for each of the contaminant exposures. Hierarchical clustering grouped the expression profiles together by contaminant class, with copper and zinc, the petroleum products and nickel, and the pesticides each forming a distinct cluster. Many of the transcriptional changes observed were consistent with patterns previously described in other crustaceans. The changes in the transcriptome demonstrated that contaminant exposure caused changes in digestive function, growth and moulting, and the cytoskeleton following metal exposure, whereas exposure to petroleum products caused changes in carbohydrate metabolism, xenobiotic metabolism and hormone cycling. Functional analysis of these gene expression profiles can provide a better understanding of modes of toxic action and permits the prediction of mixture effects within contaminated ecosystems. PMID:24334007

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

    SciTech Connect

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

    1999-08-01

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

  13. Genetic Population Structure in the Antarctic Benthos: Insights from the Widespread Amphipod, Orchomenella franklini

    PubMed Central

    Baird, Helena Phoenix; Miller, Karen Joy; Stark, Jonathan Sean

    2012-01-01

    Currently there is very limited understanding of genetic population structure in the Antarctic benthos. We conducted one of the first studies of microsatellite variation in an Antarctic benthic invertebrate, using the ubiquitous amphipod Orchomenella franklini (Walker, 1903). Seven microsatellite loci were used to assess genetic structure on three spatial scales: sites (100 s of metres), locations (1–10 kilometres) and regions (1000 s of kilometres) sampled in East Antarctica at Casey and Davis stations. Considerable genetic diversity was revealed, which varied between the two regions and also between polluted and unpolluted sites. Genetic differentiation among all populations was highly significant (FST = 0.086, RST = 0.139, p<0.001) consistent with the brooding mode of development in O. franklini. Hierarchical AMOVA revealed that the majority of the genetic subdivision occurred across the largest geographical scale, with Nem≈1 suggesting insufficient gene flow to prevent independent evolution of the two regions, i.e., Casey and Davis are effectively isolated. Isolation by distance was detected at smaller scales and indicates that gene flow in O. franklini occurs primarily through stepping-stone dispersal. Three of the microsatellite loci showed signs of selection, providing evidence that localised adaptation may occur within the Antarctic benthos. These results provide insights into processes of speciation in Antarctic brooders, and will help inform the design of spatial management initiatives recently endorsed for the Antarctic benthos. PMID:22479613

  14. Identification of a putative germ plasm in the amphipod Parhyale hawaiensis

    PubMed Central

    2013-01-01

    Background Specification of the germ line is an essential event during the embryonic development of sexually reproducing animals, as germ line cells are uniquely capable of giving rise to the next generation. Animal germ cells arise through either inheritance of a specialized, maternally supplied cytoplasm called 'germ plasm’ or though inductive signaling by somatic cells. Our understanding of germ cell determination is based largely on a small number of model organisms. To better understand the evolution of germ cell specification, we are investigating this process in the amphipod crustacean Parhyale hawaiensis. Experimental evidence from previous studies demonstrated that Parhyale germ cells are specified through inheritance of a maternally supplied cytoplasmic determinant; however, this determinant has not been identified. Results Here we show that the one-cell stage Parhyale embryo has a distinct cytoplasmic region that can be identified by morphology as well as the localization of germ line-associated RNAs. Removal of this cytoplasmic region results in a loss of embryonic germ cells, supporting the hypothesis that it is required for specification of the germ line. Surprisingly, we found that removal of this distinct cytoplasm also results in aberrant somatic cell behaviors, as embryos fail to gastrulate. Conclusions Parhyale hawaiensis embryos have a specialized cytoplasm that is required for specification of the germ line. Our data provide the first functional evidence of a putative germ plasm in a crustacean and provide the basis for comparative functional analysis of germ plasm formation within non-insect arthropods. PMID:24314239

  15. Effects of seawater alkalinity on calcium and acid-base regulation in juvenile European lobster (Homarus gammarus) during a moult cycle.

    PubMed

    Middlemiss, Karen L; Urbina, Mauricio A; Wilson, Rod W

    2016-03-01

    Fluxes of NH4(+) (acid) and HCO3(-) (base), and whole body calcium content were measured in European lobster (Homarus gammarus) during intermoult (megalopae stage), and during the first 24h for postmoult juveniles under control (~2000 μeq/L) and low seawater alkalinity (~830 μeq/L). Immediately after moulting, animals lost 45% of the total body calcium via the shed exoskeleton (exuvia), and only 11% was retained in the uncalcified body. At 24h postmoult, exoskeleton calcium increased to ~46% of the intermoult stage. Ammonia excretion was not affected by seawater alkalinity. After moulting, bicarbonate excretion was immediately reversed from excretion to uptake (~4-6 fold higher rates than intermoult) over the whole 24h postmoult period, peaking at 3-6h. These data suggest that exoskeleton calcification is not completed by 24h postmoult. Low seawater alkalinity reduced postmoult bicarbonate uptake by 29% on average. Net acid-base flux (equivalent to net base uptake) followed the same pattern as HCO3(-) fluxes, and was 22% lower in low alkalinity seawater over the whole 24h postmoult period. The common occurrence of low alkalinity in intensive aquaculture systems may slow postmoult calcification in juvenile H. gammarus, increasing the risk of mortalities through cannibalism. PMID:26691956

  16. Stage-Specific Changes in Physiological and Life-History Responses to Elevated Temperature and Pco2 during the Larval Development of the European Lobster Homarus gammarus (L.).

    PubMed

    Small, Daniel P; Calosi, Piero; Boothroyd, Dominic; Widdicombe, Steve; Spicer, John I

    2015-01-01

    An organism's physiological processes form the link between its life-history traits and the prevailing environmental conditions, especially in species with complex life cycles. Understanding how these processes respond to changing environmental conditions, thereby affecting organismal development, is critical if we are to predict the biological implications of current and future global climate change. However, much of our knowledge is derived from adults or single developmental stages. Consequently, we investigated the metabolic rate, organic content, carapace mineralization, growth, and survival across each larval stage of the European lobster Homarus gammarus, reared under current and predicted future ocean warming and acidification scenarios. Larvae exhibited stage-specific changes in the temperature sensitivity of their metabolic rate. Elevated Pco2 increased C∶N ratios and interacted with elevated temperature to affect carapace mineralization. These changes were linked to concomitant changes in survivorship and growth, from which it was concluded that bottlenecks were evident during H. gammarus larval development in stages I and IV, the transition phases between the embryonic and pelagic larval stages and between the larval and megalopa stages, respectively. We therefore suggest that natural changes in optimum temperature during ontogeny will be key to larvae survival in a future warmer ocean. The interactions of these natural changes with elevated temperature and Pco2 significantly alter physiological condition and body size of the last larval stage before the transition from a planktonic to a benthic life style. Thus, living and growing in warm, hypercapnic waters could compromise larval lobster growth, development, and recruitment. PMID:26658247

  17. A marriage of convenience; a simple food chain comprised of Lemna minor (L.) and Gammarus pulex (L.) to study the dietary transfer of zinc.

    PubMed

    Lahive, E; O'Halloran, J; Jansen, M A K

    2015-01-01

    Macrophytes contribute significantly to the cycling of metals in aquatic systems, through accumulation during growth and release during herbivory or decomposition. Accumulation of high levels of metals has been extensively documented in Lemnaceae (duckweeds). However, the degree of trophic transfer of metals from Lemnaceae to secondary consumers remains poorly understood. This study demonstrates that zinc accumulated in Lemna minor is bioavailable to the herbivore consumer Gammarus pulex. Overall, the higher the zinc content of L. minor, the more zinc accumulated in G. pulex. Accumulation in G. pulex was such that mortality occurred when they were fed high zinc-containing L. minor. Yet, the percentage of consumed zinc retained by G. pulex actually decreased with higher zinc concentrations in L. minor. We hypothesise that this decrease reflects internal zinc metabolism, including a shift from soluble to covalently bound zinc in high zinc-containing L. minor. Consistently, relatively more zinc is lost through depuration when G. pulex is fed L. minor with high zinc content. The developed Lemna-Gammarus system is simple, easily manipulated, and sensitive enough for changes in plant zinc metabolism to be reflected in metal accumulation by the herbivore, and therefore suitable to study ecologically relevant metal cycling in aquatic ecosystems. PMID:24731282

  18. Amphipods in sediment traps of the eastern Fram Strait with focus on the life-history of the lysianassoid Cyclocaris guilelmi

    NASA Astrophysics Data System (ADS)

    Kraft, Angelina; Bauerfeind, Eduard; Nöthig, Eva-Maria; Klages, Michael; Beszczynska-Möller, Agnieszka; Bathmann, Ulrich V.

    2013-03-01

    Life-cycle characteristics of the free-swimming lysianassoid amphipod Cyclocaris guilelmi were investigated and compared to those of other regularly appearing amphipods in the Arctic deep-sea community. In this context we analysed time-series data of meso- and bathypelagic amphipods collected as swimmers in moored sediment traps from 2004 to 2008 at the deep-sea long-term observatory HAUSGARTEN (79°N/4°E) in the eastern Fram Strait, Arctic Ocean. Six mesopelagic and three bathypelagic deep-sea amphipod species regularly occurred in the traps. The lysianassoid C. guilelmi showed a stable interannual population size and seasonal peaks in its occurrence from August to February during the five-year sampling period. The investigation of its population structure and reproduction ecology indicated year-round breeding behavior of this species. Up to 4 cohorts consisting mainly of juvenile and female C. guilelmi were observed. We conclude that C. guilelmi plays an important role within the Arctic amphipod deep water community.

  19. Deformities in larvae and juvenile European lobster (Homarus gammarus) exposed to lower pH at two different temperatures

    NASA Astrophysics Data System (ADS)

    Agnalt, A.-L.; Grefsrud, E. S.; Farestveit, E.; Larsen, M.; Keulder, F.

    2013-05-01

    Trends of increasing temperatures and ocean acidification are expected to influence benthic marine resources, especially calcifying organisms. The European lobster (Homarus gammarus) is among those species at risk. A project was initiated in 2011 aiming to investigate long-term synergistic effects of temperature and projected increases in ocean acidification on the life cycle of lobster. Larvae were exposed to pCO2 levels of ambient water (water intake at 90 m depth, tentatively of 380 μatm pCO2), 727 and 1217 μatm pCO2, at temperatures 10 and 18 °C. Long-term exposure lasted until 5 months of age. Thereafter the surviving juveniles were transferred to ambient water at 14 °C. At 18 °C the development from Stage 1 to 4 lasted from 14 to 16 days, as predicted under normal pH values. Growth was very slow at 10 °C and resulted in only two larvae reaching Stage 4 in the ambient treatment. There were no significant differences in carapace length at the various larval stages between the different treatments, but there were differences in total length and dry weight at Stage 1 at 10 °C, Stage 2 at both temperatures, producing larvae slightly larger in size and lighter by dry weight in the exposed treatments. Stage 3 larvae raised in 18 °C and 1217 μatm pCO2 were also larger in size and heavier by dry weight compared with 727 μatm. Unfortunate circumstances precluded a full comparison across stages and treatment. Deformities were however observed in both larvae and juveniles. At 10 °C, about 20% of the larvae exposed to elevated pCO2were deformed, compared with 0% in larvae raised in pH above 8.0. At 18 °C and in high pCO2 treatment, 31.5% of the larvae were deformed. Occurrence of deformities after 5 months of exposure was 33 and 44% in juveniles raised in ambient and low pCO2, respectively, and 20% in juveniles exposed to high pCO2. Some of the deformities will possibly affect the ability to find food, sexual partner (walking legs, claw and antenna

  20. Phylogeny as a Proxy for Ecology in Seagrass Amphipods: Which Traits Are Most Conserved?

    PubMed Central

    Best, Rebecca J.; Stachowicz, John J.

    2013-01-01

    Increasingly, studies of community assembly and ecosystem function combine trait data and phylogenetic relationships to gain novel insight into the ecological and evolutionary constraints on community dynamics. However, the key to interpreting these two types of information is an understanding of the extent to which traits are phylogenetically conserved. In this study, we develop the necessary framework for community phylogenetics approaches in a system of marine crustacean herbivores that play an important role in the ecosystem functioning of seagrass systems worldwide. For 16 species of amphipods and isopods, we (1) reconstructed phylogenetic relationships using COI, 16S, and 18S sequences and Bayesian analyses, (2) measured traits that are potentially important for assembling species between and within habitats, and (3) compared the degree to which each of these traits are evolutionarily conserved. Despite poor phylogenetic resolution for the order Amphipoda as a whole, we resolved almost all of the topology for the species in our system, and used a sampling of ultrametric trees from the posterior distribution to account for remaining uncertainty in topology and branch lengths. We found that traits varied widely in their degree of phylogenetic signal. Body mass, fecundity, and tube building showed very strong phylogenetic signal, and temperature tolerance and feeding traits showed much less. As such, the degree of signal was not predictable based on whether the trait is related to environmental filtering or to resource partitioning. Further, we found that even with strong phylogenetic signal in body size, (which may have large impacts on ecosystem function), the predictive relationship between phylogenetic diversity and ecosystem function is not straightforward. We show that patterns of phylogenetic diversity in communities of seagrass mesograzers could lead to a variety of interpretations and predictions, and that detailed study of trait similarities and

  1. Local contamination in relation to population genetic diversity and resilience of an arctic marine amphipod.

    PubMed

    Bach, Lis; Dahllöf, Ingela

    2012-06-15

    The objective of this study was to investigate whether populations inhabiting a contaminated environment are affected in terms of decreased genetic diversity due to selection of tolerant genotypes and if such effect carries a cost. Marine arctic amphipod populations (Orchomenella pinguis) were collected from sites within a contaminated fjord, as well as from sites outside the fjord on the west-coast of Greenland over three years (2006-2008). Impacts on genetic diversity, effects on resilience such as development of tolerance and cost were determined. AFLP-analysis was used to explore within and between population genetic diversity, and exposure studies were performed where the populations were subjected to known and unknown stressors to assess resilience. Populations collected at three contaminated sites all had reduced genetic diversity in 2007 compared to populations outside the fjord. This pattern was different in 2008 as all contaminated site populations increased in diversity, whereas a decrease in diversity occurred at the outer sites. However, tolerance, but even more so, cost, was related to contamination exposure in 2008, in spite of the shift in genetic diversity. We suggest that contamination rapidly induces effects that can be captured as tolerance and associated cost, whereas effects on genetic diversity can be difficult to separate from recent migration events that dilute eventual decreases in diversity due to contamination pressure. As long as impacted populations can be influenced by migration events that increase the genetic diversity and add health to an affected population, populations in contaminated areas may have enhanced probability of survival. PMID:22421731

  2. Toxicity of oil dispersant, crude oil and dispersed crude oil to a marine amphipod and gastropod

    SciTech Connect

    Gulec, I.; Holdway, D.A.

    1995-12-31

    The importance of appropriate oil spill remedial action was emphasized during the recent Iron Barron oil spill off of the Tamar river in North Tasmania. One important potential oil spill response is dispersion, but little information exists on the toxicity of dispersants and dispersed oil to Australian marine species. This research was undertaken to assess the acute toxicity of Corexit 9527 (a widely used dispersant), water accommodated fractions of Bass Strait crude oil and dispersed Bass Strait crude oil, to the saltwater amphipod, Allorchestes compressa under semi-static conditions. Acute 96 h LC50`s were determined for each toxicant as well as for the reference toxicants sodium dodecyl sulfate (SDS) and zinc sulfate. Sublethal bioassays were undertaken for the same 3 toxicants utilizing the marines and snail Polinices conicus as the test species. No-observed-effect-concentrations (NOEC) and lowest-observed-effect-concentrations (LOEC) were determined using ANOVA while EC50`s and EC0`s were calculated using regression analysis. Mean acute 96 h LC50 (S.E.) values for A. compressa exposed to SDS and zinc sulfate were 3.6 mg/l (0.28) and 41.6 mg/l (9.01) respectively. EC50 (S.E.) concentrations for P. conicus exposed to SDS and zinc sulfate for 30 minutes were 44.7 mg/l and 246 mg/l respectively using burying behavior as an endpoint. These sublethal EC50`s were reduced to 20.7 mg/l for SDS and 23.5 mg/l for zinc sulfate following 24 hours of exposure.

  3. Cerium oxide nanoparticles induce oxidative stress in the sediment-dwelling amphipod Corophium volutator.

    PubMed

    Dogra, Yuktee; Arkill, Kenton P; Elgy, Christine; Stolpe, Bjorn; Lead, Jamie; Valsami-Jones, Eugenia; Tyler, Charles R; Galloway, Tamara S

    2016-05-01

    Cerium oxide nanoparticles (CeO2 NPs) exhibit fast valence exchange between Ce(IV) and Ce(III) associated with oxygen storage and both pro and antioxidant activities have been reported in laboratory models. The reactivity of CeO2 NPs once they are released into the aquatic environment is virtually unknown, but this is important to determine for assessing their environmental risk. Here, we show that amphipods (Corophium volutator) grown in marine sediments containing CeO2 NPs showed a significant increase in oxidative damage compared to those grown in sediments without NPs and those containing large-sized (bulk) CeO2 particles. There was no exposure effect on survival, but significant increases in single-strand DNA breaks, lipid peroxidation and superoxide dismutase activity were observed after a 10-day exposure to 12.5 mg L(-1) CeO2. Characterisation of the CeO2 NPs dispersed in deionised or saline exposure waters revealed that more radicals were produced by CeO2 NPs compared with bulk CeO2. Electron energy loss spectroscopy (EELS) analysis revealed that both CeO2 NPs were predominantly Ce(III) in saline waters compared to deionised waters where they were predominantly Ce(IV). In both types of medium, the bulk CeO2 consisted mainly of Ce(IV). These results support a model whereby redox cycling of CeO2 NPs between Ce(III) and Ce(IV) is enhanced in saline waters, leading to sublethal oxidative damage to tissues in our test organism. PMID:26554927

  4. Nutritional analysis of freshwater and marine amphipods from the Strait of Gibraltar and potential aquaculture applications

    NASA Astrophysics Data System (ADS)

    Baeza-Rojano, Elena; Hachero-Cruzado, Ismael; Guerra-García, José M.

    2014-01-01

    Four gammarid and four caprellid amphipod species from the Strait of Gibraltar were analyzed to study their nutritional contents: Caprella dilatata, Caprella equilibra, Caprella grandimana, Caprella penantis, Elasmopus rapax, Hyale perieri and Jassa sp. from marine water habitats and Echinogammarus sp. from freshwater habitats. Lipids, proteins, carbohydrates, ash and water contents were measured. Proteins and ash were the most abundant components in all the species, ranging between 37.9 and 44.6% and 29.3 and 39.7% dry weight, respectively. The lipid and carbohydrate contents showed lower levels (5.1-9.6% and 3.1-9.1% dry weight, respectively). No significant differences in general biochemical composition were found between gammarid and caprellid species. The most abundant fatty acids were the polyunsaturated ones (38.3%) with high levels of EPA (20:5(n-3)) with 8.5 to 17.7%, DHA (22:6(n-3)) with 0.9 to 13.6% and ARA (20:4(n-6)) with 1.7 to 5.8%. Caprellid species were characterized by a higher percentage of polyunsaturated fatty acids, while the freshwater gammarid species showed the lowest levels. According to lipid classes, caprellids had higher phospholipids levels and lower triacylglycerol levels, as well as a higher content of polar lipids than the gammarids, being more suitable for their use in aquaculture. Differences in the general biochemical composition between species can be related to habitat characteristics, diets and environmental conditions. Advantages and disadvantages of the use of these organisms in aquaculture are discussed.

  5. Linking sub-cellular biomarkers to embryo aberrations in the benthic amphipod Monoporeia affinis.

    PubMed

    Reutgard, Martin; Furuhagen, Sara

    2016-04-01

    To adequately assess and monitor environmental status in the aquatic environment a broad approach is needed that integrates physical variables, chemical analyses and biological effects at different levels of the biological organization. Embryo aberrations in the Baltic Sea key species Monoporeia affinis can be induced by both metals and organic substances as well as by hypoxia, increasing temperatures and malnutrition. This amphipod has therefore been used for more than three decades as a biological effect indicator in monitoring and assessment of chemical pollution and environmental stress. However, little is known about the sub-cellular mechanisms underlying embryo aberrations. An improved mechanistic understanding may open up the possibility of including sub-cellular alterations as sensitive warning signals of stress-induced embryo aberrations. In the present study, M. affinis was exposed in microcosms to 4 different sediments from the Baltic Sea. After 88-95 days of exposure, survival and fecundity were determined as well as the frequency and type of embryo aberrations. Moreover, oxygen radical absorption capacity (ORAC) was assayed as a proxy for antioxidant defense, thiobarbituric acid reactive substances (TBARS) level as a measure of lipid peroxidation and acetylcholinesterase (AChE) activity as an indicator of neurotoxicity. The results show that AChE and ORAC can be linked to the frequency of malformed embryos and arrested embryo development. The occurrence of dead broods was significantly associated with elevated TBARS levels. It can be concluded that these sub-cellular biomarkers are indicative of effects that could affect Darwinian fitness and that oxidative stress is a likely mechanism in the development of aberrant embryos in M. affinis. PMID:26836507

  6. Corophiine amphipods of the genera Chelicorophium and Paracorophium from the lower Gulf of Thailand (Crustacea, Amphipoda, Corophiidae, Corophiinae)

    PubMed Central

    Wongkamhaeng, Koraon; Nabhitabhata, Jaruwat; Towatana, Prawit

    2015-01-01

    Abstract Two species of corophiine amphipods from Songkhla Lake, in the lower Gulf of Thailand, are described and illustrated. Chelicorophium madrasensis (Nayar, 1950), found in the mangrove forest, has not previously been observed in Thai waters. Paracorophium angsupanichae sp. n. is characterized by its chelate male gnathopod 2, obtuse palm with subrectangular distomedial elevation, and urosomites 1-3 free. This is the first record of the genus Chelicorophium and Paracorophium in Thai waters. All specimens are deposited in the Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand and the Museum für Naturkunde, Berlin. PMID:26052237

  7. Leucothoe eltoni sp. n., a new species of commensal leucothoid amphipod from coral reefs in Raja Ampat, Indonesia (Crustacea, Amphipoda)

    PubMed Central

    Thomas, James Darwin

    2015-01-01

    Abstract A new species of leucothoid amphipod, Leucothoe eltoni sp. n., is described from coral reefs in Raja Ampat, Indonesia where it inhabits the branchial chambers of solitary tunicates. With an inflated first gnathopod superficially resembling the genus Paraleucothoe, this new species has a two-articulate maxilla 1 palp characteristic of the genus Leucothoe. While described from coral reef environments in tropical Indonesia and the Philippines, it is an established invasive species in the Hawaiian Islands. The most likely mode of introduction was a US Navy dry dock transported to Pearl Harbor in 1992 from Subic Bay, Philippines. PMID:26448700

  8. Leucothoe eltoni sp. n., a new species of commensal leucothoid amphipod from coral reefs in Raja Ampat, Indonesia (Crustacea, Amphipoda).

    PubMed

    Thomas, James Darwin

    2015-01-01

    A new species of leucothoid amphipod, Leucothoe eltoni sp. n., is described from coral reefs in Raja Ampat, Indonesia where it inhabits the branchial chambers of solitary tunicates. With an inflated first gnathopod superficially resembling the genus Paraleucothoe, this new species has a two-articulate maxilla 1 palp characteristic of the genus Leucothoe. While described from coral reef environments in tropical Indonesia and the Philippines, it is an established invasive species in the Hawaiian Islands. The most likely mode of introduction was a US Navy dry dock transported to Pearl Harbor in 1992 from Subic Bay, Philippines. PMID:26448700

  9. Effect of Climate-Related Change in Vegetation on Leaf Litter Consumption and Energy Storage by Gammarus pulex from Continental or Mediterranean Populations

    PubMed Central

    Foucreau, Natacha; Piscart, Christophe; Puijalon, Sara; Hervant, Frédéric

    2013-01-01

    As a consequence of global warming, it is important to characterise the potential changes occurring for some functional processes through the intra-specific study of key species. Changes in species distribution, particularly when key or engineer species are affected, should contribute to global changes in ecosystem functioning. In this study, we examined the potential consequences induced by global warming on ecosystem functioning in term of organic matter recycling. We compared consumption of leaf litter by some shredder populations (Gammarus pulex) between five tree species inhabiting continental (i.e., the northern region of the Rhône River Valley) and/or Mediterranean (i.e., the southern region of the Rhône River Valley) conditions. To consider any potential adaptation of the gammarid population to vegetation in the same climate conditions, three populations of the key shredder Gammarus pulex from the northern region and three from the southern region of the Rhône River Valley were used. We experimentally compared the effects of the geographical origin of both the gammarid populations and the leaf litter species on the shredding activity and the physiological state of animals (through body triglyceride content). This study demonstrated that leaf toughness is more important than geographical origin for determining shredder leaf litter consumption. The overall consumption rate of the gammarid populations from the southern region of Rhône Valley was much higher than that of the populations from the northern region, but no clear differences between the origins of the leaf litter (i.e., continental vs. Mediterranean) were observed. The northwards shift of G. pulex populations adapted to warmer conditions might significantly modify organic matter recycling in continental streams. As gammarid populations can demonstrate local adaptations to certain leaf species as a trophic resource, changes in riparian vegetation associated with climate change might locally

  10. Amphipod-supported food web: Themisto gaudichaudii, a key food resource for fishes in the southern Patagonian Shelf

    NASA Astrophysics Data System (ADS)

    Padovani, Luciano N.; Viñas, María Delia; Sánchez, Felisa; Mianzan, Hermes

    2012-01-01

    The trophic role of the hyperiid amphipod Themisto gaudichaudii in the southern Patagonian shelf food web was assessed from the analysis of stomach contents of the local fish assemblage. A total of 461 trawl samples were collected during seven seasonal cruises. A total of 17 out of 38 fish species were found to ingest T. gaudichaudii. This amphipod was a main prey item in five of these species, showing high values of alimentary index: Seriolella porosa (99.9%), Macruronus magellanicus (68.8%), Micromesistius australis (59.1%), Patagonotothen ramsayi (48.6%), and Merluccius hubbsi (10.9%). The contribution of T. gaudichaudii, in weight, to their summer diet was 60%, on average. This contribution was minimal in winter and maximal in summer. Fisheries studies have indicated that these five species, mainly M. magellanicus, account for almost 85% of the fish biomass in the area. Although the remaining 15% did not feed heavily on T. gaudichaudii, they are known to prey on the main hyperiid predators. Our study shows that T. gaudichaudii contributes greatly, both directly and indirectly, to supporting the fish community. We thus proposed that T. gaudichaudii plays a key role as a "wasp-waist" species in the sub-Antarctic region, similar to that of krill in Antarctic waters, channeling the energy flow and enabling a short and efficient food chain.

  11. First finding of the amphipod Echinogammarus ischnus and the mussel Dreissena bugensis in Lake Michigan

    USGS Publications Warehouse

    Nalepa, Thomas F.; Schloesser, Don W.; Pothoven, Steve A.; Hondorp, Darryl W.; Fanslow, David L.; Tuchman, Marc L.; Fleischer, Guy W.

    2001-01-01

    The first finding of the amphipod Echinogammarus ischnus and the mussel Dreissena bugensis in Lake Michigan is documented. These two species are widespread and abundant in the lower lakes, but had not yet been reported from Lake Michigan. E. ischnus is generally considered a warm-water form that is typically associated wtih hard substrates and Dreissena clusters in the nearshore zone. Along the eastern shoreline of Lake Michigan, this species was present at rocky, breakwall habitats, along the entire north-south axis of the lake. Although not abundant, this species was also found at soft-bottom sites as deep as 94 m in the southern basin. The finding of this species in deep offshore waters apparently extends the known habitat range for this species in the Great Lakes, but it is found in deep water areas within its native range (Caspian Sea). D. bugensis was not abundant, but was present in both the southern and northern portions of the lake. Individuals of up to 36 mm in length were collected, indicating that it had probably been present in the lake for 2 or more years. Also presented are depth-defined densities of D. polymorpha at 37 sites in the Straits of Mackinac in 1997, and densities at up to 55 sites in the southern basin in 1992/93 and 1998/99. Mean densities decreased with increased water depth in both regions. Maximum mean density in the Straits in 1997 was 13,700/mA? (a?? 10 m), and maximum density in the southern basin in 1999 was 2,100/mA? (a?? 30 m). Mean densities at the a?? 30-m interval in the southern basin remained relatively unchanged between 1993 and 1999, but increased from 25/mA? to 1,100/mA? at the 31 to 50 m interval over the same time period. D. polymorpha was rare at sites > 50 m. The presence of E. ischnus and the expected population expansion of D. bugensis will likely contribute to further foodweb changes in the lake.

  12. Effect of diet quality on chronic toxicity of aqueous lead to the amphipod Hyalella azteca

    USGS Publications Warehouse

    Besser, John M.; Ivey, Chris D.; Brumbaugh, William G.; Ingersoll, Christopher G.

    2016-01-01

    The authors investigated the chronic toxicity of aqueous Pb to the amphipod Hyalella azteca (Hyalella) in 42-d tests using 2 different diets: 1) the yeastþcereal leafþtrout pellet (YCT) diet, fed at the uniform low ration used in standard methods for sediment toxicity tests; and 2) a new diet of diatomsþTetraMin flakes (DT), fed at increasing rations over time, that has been optimized for use in Hyalella water-only tests. Test endpoints included survival, weight, biomass, fecundity, and total young. Lethal effects of Pb were similar for the DT and YCT tests (20% lethal concentration [LC20]¼13 mg/L and 15mg/L, respectively, as filterable Pb). In contrast, weight and fecundity endpoints were not significantly affected in the DT test at Pb concentrations up to 63 mg/L, but these endpoints were significantly reduced by Pb in the YCT test—and in a 2005 test in the same laboratory with a diet of conditioned Rabbit Chow (RC-2005). The fecundity and total young endpoints from the YCT and RC-2005 tests were considered unreliable because fecundity in controls did not meet test acceptability criteria, but both of these tests still produced lower Pb effect concentrations (for weight or biomass) than the test with the DT diet. The lowest biotic ligand model–normalized effect concentrations for the 3 tests ranged from 3.7mg/L (weight 20% effect concentration [EC20] for the RC-2005 test) to 8.2 mg/L (total young EC20 for the DT test), values that would rank Hyalella as the second or third most sensitive of 13 genera in a species sensitivity distribution for chronic Pb toxicity. These results demonstrate that toxicity tests with Hyalella fed optimal diets can meet more stringent test acceptability criteria for control performance, but suggest that results of these tests may underestimate sublethal toxic effects of Pb to Hyalella under suboptimal feeding regimes.

  13. Effect of diet quality on chronic toxicity of aqueous lead to the amphipod Hyalella azteca.

    PubMed

    Besser, John M; Ivey, Chris D; Brumbaugh, William G; Ingersoll, Christopher G

    2016-07-01

    The authors investigated the chronic toxicity of aqueous Pb to the amphipod Hyalella azteca (Hyalella) in 42-d tests using 2 different diets: 1) the yeast + cereal leaf + trout pellet (YCT) diet, fed at the uniform low ration used in standard methods for sediment toxicity tests; and 2) a new diet of diatoms + TetraMin flakes (DT), fed at increasing rations over time, that has been optimized for use in Hyalella water-only tests. Test endpoints included survival, weight, biomass, fecundity, and total young. Lethal effects of Pb were similar for the DT and YCT tests (20% lethal concentration [LC20] = 13 μg/L and 15 μg/L, respectively, as filterable Pb). In contrast, weight and fecundity endpoints were not significantly affected in the DT test at Pb concentrations up to 63 µg/L, but these endpoints were significantly reduced by Pb in the YCT test-and in a 2005 test in the same laboratory with a diet of conditioned Rabbit Chow (RC-2005). The fecundity and total young endpoints from the YCT and RC-2005 tests were considered unreliable because fecundity in controls did not meet test acceptability criteria, but both of these tests still produced lower Pb effect concentrations (for weight or biomass) than the test with the DT diet. The lowest biotic ligand model-normalized effect concentrations for the 3 tests ranged from 3.7 μg/L (weight 20% effect concentration [EC20] for the RC-2005 test) to 8.2 μg/L (total young EC20 for the DT test), values that would rank Hyalella as the second or third most sensitive of 13 genera in a species sensitivity distribution for chronic Pb toxicity. These results demonstrate that toxicity tests with Hyalella fed optimal diets can meet more stringent test acceptability criteria for control performance, but suggest that results of these tests may underestimate sublethal toxic effects of Pb to Hyalella under suboptimal feeding regimes. Environ Toxicol Chem 2016;35:1825-1834. Published 2015 Wiley Periodicals Inc

  14. Deformities in larvae and juvenile European lobster (Homarus gammarus) exposed to lower pH at two different temperatures

    NASA Astrophysics Data System (ADS)

    Agnalt, A.-L.; Grefsrud, E. S.; Farestveit, E.; Larsen, M.; Keulder, F.

    2013-12-01

    The ongoing warming and acidification of the world's oceans are expected to influence the marine ecosystems, including benthic marine resources. Ocean acidification may especially have an impact on calcifying organisms, and the European lobster (Homarus gammarus) is among those species at risk. A project was initiated in 2011 aiming to investigate long-term effects of ocean acidification on the early life-cycle of lobster under two temperatures. Larvae were exposed to pCO2 levels of ambient water (water intake at 90 m depth), medium 750 (pH = 7.79) and high 1200 μatm pCO2 (pH = 7.62) at temperatures 10 and 18 °C. The water parameters in ambient water did not stay stable and were very low towards the end of the experiment in the larval phase at 10 °C,with pH between 7.83 and 7.90. At 18°, pH in ambient treatment was even lower, between 7.76 and 7.83, i.e. close to medium pCO2 treatment. Long-term exposure lasted 5 months. At 18 °C the development from stage 1 to 4 lasted 14 to 16 days, as predicted under optimal water conditions. Growth was very slow at 10 °C and resulted in three larvae reaching stage 4 in high pCO2 treatment only. There were no clear effects of pCO2 treatment, on either carapace length or dry weight. However, deformities were observed in both larvae and juveniles. The proportion of larvae with deformities increased with increasing pCO2 exposure, independent of temperature. In the medium treatment about 23% were deformed, and in the high treatment about 43% were deformed. None of the larvae exposed to water of pH >7.9 developed deformities. Curled carapace was the most common deformity found in larvae raised in medium pCO2 treatment, irrespective of temperature, but damages in the tail fan occurred in addition to a bent rostrum. Curled carapace was the only deformity found in high pCO2 treatment at both temperatures. Occurrence of deformities after five months of exposure was 33 and 44% in juveniles raised in ambient and low pCO2 levels

  15. SENSITIVITY OF AN INFAUNAL AMPHIPOD, EOHAUSTORIUS ESTUARIUS, TO ACUTE WATER-BORN EXPOSURES OF 4-NONYLPHENOL (NP): EVIDENCE OF A TOXIC HANGOVER

    EPA Science Inventory

    Three independent trials were conducted using mortality and burial as endpoints. Mean LC50 was 227 ug/l. One hour burial as a sub-lethal endpoint increased the sensitivity of the toxicity test by 40%; however most amphipods that survived exposure were able to recover within 24-48...

  16. Optimizing the performance of the amphipod, Hyalella azteca, in chronic toxicity tests: Results of feeding studies with various foods and feeding regimes

    EPA Science Inventory

    The freshwater amphipod, Hyalella azteca, is a common organism used for sediment toxicity testing. Standard methods for 10-d and 42-d sediment toxicity tests with H. azteca were last revised and published by USEPA/ASTM in 2000. While Hyalella azteca methods exist for sediment tox...

  17. Testing for the induction of anti-herbivory defences in four Portuguese macroalgae by direct and water-borne cues of grazing amphipods

    NASA Astrophysics Data System (ADS)

    Yun, Hee Young; Cruz, Joana; Treitschke, Michaela; Wahl, Martin; Molis, Markus

    2007-09-01

    Herbivory is a key factor in regulating plant biomass, thereby driving ecosystem performance. Algae have developed multiple adaptations to cope with grazers, including morphological and chemical defences. In a series of experiments we investigated whether several species of macroalgae possess anti-herbivore defences and whether these could be regulated to demand, i.e. grazing events. The potential of direct grazing on defence induction was assessed for two brown ( Dictyopteris membranacea, Fucus vesiculosus) and two red seaweeds ( Gelidium sesquipedale, Sphaerococcus coronopifolius) from São Rafael and Ria Formosa, Portugal. Bioassays conducted with live algal pieces and agar-based food containing lipophilic algal extracts were used to detect changes in palatability after exposure to amphipod attacks (=treatment phase). Fucus vesiculosus was the only species significantly reducing palatability in response to direct amphipod-attacks. This pattern was observed in live F. vesiculosus pieces and agar-based food containing a lipophilic extract, suggesting that lipophilic compounds produced during the treatment phase were responsible for the repulsion of grazers. Water-borne cues of grazed F. vesiculosus as well as non-grazing amphipods also reduced palatability of neighbouring conspecifics. However, this effect was only observed in live tissues of F. vesiculosus. This study is the first to show that amphipods, like isopods, are capable to induce anti-herbivory defences in F. vesiculosus and that a seasonally variable effectiveness of chemical defences might serve as a dynamic control in alga-herbivore interactions.

  18. SITE-SPECIFIC VALIDATION OF A CHRONIC TOXICITY TEST WITH THE AMPHIPOD HYALELLA AZTECA : AN INTEGRATED STUDY OF HEAVY METAL CONTAMINATED SEDIMENTS IN PEAK CREEK, VIRGINIA

    EPA Science Inventory

    We will measure the correspondence of endpoints from chronic toxicity tests with the amphipod, Hyalella azteca, to a series of in situ macrobenthic community endpoints, starting with those endpoints most similar to those monitored in the laboratory test, then expanding to include...

  19. The supergiant amphipod Alicella gigantea (Crustacea: Alicellidae) from hadal depths in the Kermadec Trench, SW Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Jamieson, A. J.; Lacey, N. C.; Lörz, A.-N.; Rowden, A. A.; Piertney, S. B.

    2013-08-01

    Here we provide the first record of the 'supergiant' amphipod Alicella gigantea Chevreux, 1899 (Alicellidae) from the Southern Hemisphere, and extend the known bathymetric range by over 1000 m to 7000 m. An estimated nine individuals were observed across 1500 photographs taken in situ by baited camera at 6979 m in the Kermadec Trench, SW Pacific Ocean. Nine specimens, ranging in length from 102 to 290 mm were recovered by baited trap at depths of 6265 m and 7000 m. Mitochondrial and nuclear DNA sequences obtained indicate a cosmopolitan distribution for the species. Data and observations from the study are used to discuss the reason for gigantism in this species, and its apparently disjunct geographical distribution.

  20. Shallow water marine gammaridean amphipods of Pulau Tioman, Malaysia, with the description of a new species

    PubMed Central

    Azman, B.A.R.; Othman, B.H.R.

    2013-01-01

    Abstract Eleven taxa including one new species of gammaridean amphipods are reported from the waters of Pulau Tioman. The presence of Tethygeneia sunda sp. n. represents the first record of the genus from the South China Sea. Additional material of Ampelisca brevicornis (Costa, 1853); Cymadusa vadosa Imbach, 1967; Paradexamine setigera Hirayama, 1984; Ericthonius pugnax (Dana, 1853); Leucothoe furina (Savigny, 1816); Microlysias xenokeras (Stebbing, 1918); Monoculodes muwoni Jo, 1990 are identified from the South China Sea, supporting previous records by Lowry (2000), Huang (1994), Imbach (1967), Margulis (1968) and Nagata (1959). Three additional species, Gitanopsis pusilla K.H. Barnard, 1916, Liljeborgia japonica Nagata, 1965b and Latigammaropsis atlantica (Stebbing, 1888), whilst previously reported from the neighbouring waters, comprise new records for the South China Sea. PMID:24146563

  1. The Distribution of Talitrid Amphipods (Crustacea) on a Salt Marsh in Southern Tasmania, in relation to Vegetation and Substratum

    NASA Astrophysics Data System (ADS)

    Richardson, A. M. M.; Mulcahy, M. E.

    1996-12-01

    Supralittoral and terrestrial talitrid amphipods were collected from a salt marsh in Southern Tasmania by pitfall trapping along transects from the mid-tidal level to above the high-tide mark, and by hand collecting from sites chosen to represent the full range from salt marsh to terrestrial vegetation. At each site, the cover of all major plant species was recorded, and soil samples were collected from which soil moisture, organic content and salinity were measured. Eight talitrid species from four ecological groups were collected; one palustral species, one beachflea, three coastal landhoppers and three eastern forest landhoppers. There was substantial overlap in the distributions of these groups. The undescribed beachflea had the widest distribution, from the wettest, most saline sites to the Schoenus nitenstussock grassland at the extreme high-tide mark. The palustral species, Eorchestia palustris, overlapped substantially with the beachflea, but was found within a narrower band of salinities (though not in the most saline sites) and in more poorly-drained sites than the beachflea. Coastal landhoppers, Austrotroides maritimus, Keratroides rexand an undescribed species of Tasmanorchestia, were found mainly in the S. nitenstussock grassland, where they overlapped with forest landhoppers, Keratroides vulgaris, Mysticotalitrus tasmaniaeand M. cryptus, which were found mainly in non-saltmarsh terrestrial sites, well above the high-tide mark. These distributions are discussed in terms of the likelihood that salt marshes provided the route by which talitrid amphipods colonized land. There is no reason from these data to reject salt marshes as the route to land, and it is suggested that they are a more likely route than via rocky or sandy shores.

  2. The Hadal Amphipod Hirondellea gigas Possessing a Unique Cellulase for Digesting Wooden Debris Buried in the Deepest Seafloor

    PubMed Central

    Kobayashi, Hideki; Hatada, Yuji; Tsubouchi, Taishi; Nagahama, Takahiko; Takami, Hideto

    2012-01-01

    The Challenger Deep in the Mariana Trench is the deepest point in the ocean (10,994 m). Certain deep-sea animals can withstand the extreme pressure at this great depth. The amphipod Hirondellea gigas is a resident of the Challenger Deep. Amphipods are common inhabitants at great depths and serve as scavengers. However, there is relatively little information available regarding the physiology of H. gigas or this organism's ecological interactions in the hadopelagic zone. To understand the feeding behavior of this scavenger in the deepest oligotrophic hadal zone, we analyzed the digestive enzymes in whole-body extracts. We describe the detection of amylase, cellulase, mannanase, xylanase, and α-glycosidase activities that are capable of digesting plant-derived polysaccharides. Our identification of glucose, maltose, and cellobiose in the H. gigas extracts indicated that these enzymes function under great pressure in situ. In fact, the glucose content of H. gigas averaged 0.4% (w/dry-w). The purified H. gigas cellulase (HGcel) converted cellulose to glucose and cellobiose at an exceptional molar ratio of 2∶1 and efficiently produced glucose from dried wood, a natural cellulosic biomass, at 35°C. The enzyme activity increased under a high hydrostatic pressure of 100 MPa at 2°C, conditions equivalent to those found in the Challenger Deep. An analysis of the amino acid sequence of HGcel supported its classification as a family 31 glycosyl hydrolase. However, none of the enzymes of this family had previously been shown to possess cellulase activity. These results strongly suggested that H. gigas adapted to its extreme oligotrophic hadal oceanic environment by evolving digestive enzymes capable of digesting sunken wooden debris. PMID:22905166

  3. Influence of cooling rate on the ability of frozen-thawed sperm to bind to heterologous zona pellucida, as assessed by competitive in vitro binding assays in the ocelot (Leopardus pardalis) and tigrina (Leopardus tigrinus).

    PubMed

    Baudi, D L K; Jewgenow, K; Pukazhenthi, B S; Spercoski, K M; Santos, A S; Reghelin, A L S; Candido, M V; Javorouski, M L; Müller, G; Morais, R N

    2008-01-15

    We evaluated the influence of two cooling rates (from 25 to 5 degrees C) on post-thaw function of frozen sperm in ocelots (Leopardus pardalis; n=3 males) and tigrinas (Leopardus tigrinus; n=4 males). Seven normospermic (>70% normal sperm) electroejaculates from each species were diluted with a 4% glycerol freezing medium, divided into two aliquots, and assigned to one of two cooling rates: fast or slow (0.7 or 0.16 degrees C/min, respectively). Sperm motility index (SMI) and percentage of sperm with an intact acrosome were assessed before freezing and after thawing, and the ability of sperm to bind to the zona pellucida of IVM domestic cat oocytes were assessed in a competitive in vitro sperm-binding assay. Regardless of the cooling rate, frozen-thawed sperm from both species exhibited a SMI of 50; approximately 20 and approximately 32% of post-thaw sperm had an intact acrosome in ocelots and tigrinas, respectively (P<0.05). The mean (+/-S.E.M.) number of sperm bound per oocyte was higher for fast-cooled (8.5+/-1.3) than slow-cooled (2.5+/-0.3; P<0.01) ocelot sperm. In contrast, more tigrina sperm bound to domestic cat oocytes when cooled slowly versus quickly (5.8+/-0.9 versus 2.7+/-0.4, P<0.05). In conclusion, cryopreservation decreased sperm function in both species, and the oocyte-binding assay was the most efficient method to detect functional differences in post-thaw sperm. PMID:17977588

  4. Detailed surface morphology of the 'lobster louse' copepod, Nicothoë astaci, a haematophagous gill parasite of the European lobster, Homarus gammarus.

    PubMed

    Davies, Charlotte E; Thomas, Gethin R; Maffeis, Thierry G G; Wootton, Emma C; Penny, Mark W; Rowley, Andrew F

    2014-10-01

    The ectoparasitic copepod, Nicothoë astaci (the 'lobster louse'), infests the gills of the European lobster, Homarus gammarus. There have been limited studies on this haematophagous species; therefore knowledge of this parasite is rudimentary. The current study examines the surface morphology of this parasitic copepod, detached from the host, concentrating on adaptations of the suctorial mouthpart, the oral disc. Cryo-scanning electron microscopy revealed structural adaptations that facilitate attachment of these parasites to the gill filaments of their lobster host. The aperture of the feeding channel, through which host haemolymph is drawn, is only ca. 5μm in diameter. The edge of the oral disc is lined with numerous setae, whilst the surface of the disc is covered with large numbers of small (<1μm in diameter) teeth-like structures, which presumably pierce through, and grip, the cuticle lining of the host's gill. Overall, these structures are thought to provide a 'vacuum seal' to assist in pumping of blood, via peristalsis, into the alimentary canal of the copepod host. PMID:25196471

  5. The effects of power station entrainment passage on three species of marine planktonic crustacean, Acartia tonsa (Copepoda), Crangon crangon (Decapoda) and Homarus gammarus (Decapoda).

    PubMed

    Bamber, Roger N; Seaby, Richard M H

    2004-05-01

    Experiments have been undertaken exposing larval common shrimp (Crangon crangon) and lobster (Homarus gammarus) and adult copepods (Acartia tonsa) to the key stresses of entrainment within power-station cooling-water systems. The apparatus has enabled the testing of mechanical, thermal, chlorine and realistic pressure effects both alone and in combination, the range of stressors spanning the standard conditions found within a temperate coastal direct-cooled power station. Mechanical stresses affected only lobster larvae, pressure changes affected only the Acartia adults. Residual chlorine caused significant mortality of Acartia and shrimp larvae, but had no effect on lobster larvae even at 1 ppm. The temperature increment significantly affected all three species, with a synergistic effect on chlorine sensitivity in the shrimp larvae, but only temperatures higher than would be experienced in a normally-operating power station affected the copepods. The majority of individuals of each species would survive passage through a power-station system under normal conditions. It is notable that, within the species tested, generalizations from the responses of one species to those of another are not valid. PMID:14749060

  6. Geographic range and structure of cryptic genetic diversity among Pacific North American populations of the non-native amphipod Grandidierella japonica

    USGS Publications Warehouse

    Pilgrim, Erik M.; Blum, Michael J.; Reusser, Deborah A.; Lee, Henry, II; Darling, John A.

    2013-01-01

    Reconstructing the invasion history of aquatic invasive species can enhance understanding of invasion risks by recognizing areas most susceptible to invasion and forecasting future spread based on past patterns of population expansion. Here we reconstruct the invasion history of the Japanese amphipod Grandidierella japonica Stephensen 1938 combining information from historical collection data with molecular genetic data to better understand post-invasion range expansion and anthropogenic connectivity across the Pacific coast of North America. Compilation of collection data from bays and estuaries of the Pacific North American coast show many new localities have been colonized in the last two decades, moving outward from harbors and bays with high commercial traffic into smaller coastal locations dominated by local recreational traffic. DNA barcode sequence data for G. japonica reveals two distinct clades: one found in San Francisco Bay and sites to the north, and one also found in San Francisco Bay and sites to the south. The two clades differ by an average 7.28 % genetic distance, large enough to consider these invasive amphipods two separate species. Both northern and southern clades exhibit low levels of genetic diversity, suggesting a single introduction event for each. The presence of cryptic diversity within this invasive amphipod highlights the need for more extensive study of the invasive and native populations of aquatic invasive invertebrates to address questions of taxonomy, diversity, and invasion history.

  7. Biological testing of sediment for the Olympia Harbor Navigation Improvement Project, 1988: Geoduck, amphipod, and echinoderm bioassays

    SciTech Connect

    Ward, J.A.; Word, J.Q.; Antrim, L.D.

    1989-05-01

    The Olympia Harbor Navigation Improvement Project requires the dredging of approximately 330,000 cubic yards (cy) of sediment from the harbor entrance channel and 205,185 cy from the turning basin. Puget Sound Dredged Disposal Analysis (PSDDA) partial characterization studies were used to plan a full sediment characterization in which chemical analyses and biological testing of sediments evaluated the suitability of the dredged material for unconfined, open-water disposal. The US Army Corps of Engineers (COE), Seattle District, contracted with NOAA/NMFS, Environmental Conservation Division, to perform the chemical analysis and Microtox bioassay tests, and with the Battelle/Marine Sciences Laboratory (MSL) in Sequim to perform flow-through solid-phase bioassays utilizing juvenile (8 to 10 mm) geoduck clams, Panopea generosa, and static solid phase bioassays using the phoxocephalid amphipod, Rhepoxynius abronius, developing embryos and gametes of the purple sea urchin, Strongylocentrotus purpuratus, and the larvae of the Pacific oyster Crassostrea gigas. When the results of the biological tests were evaluated under PSDDA guidelines, it was found that all the tested sediment treatments from Olympia Harbor are suitable for unconfined open-water disposal. 14 refs., 12 figs., 3 tabs.

  8. Respiratory Response of the Deep-Sea Amphipod Stephonyx biscayensis Indicates Bathymetric Range Limitation by Temperature and Hydrostatic Pressure

    PubMed Central

    Brown, Alastair; Thatje, Sven

    2011-01-01

    Depth zonation of fauna on continental margins is well documented. Whilst increasing hydrostatic pressure with depth has long been considered a factor contributing significantly to this pattern, discussion of the relative significance of decreasing temperature with depth has continued. This study investigates the physiological tolerances of fed and starved specimens of the bathyal lysianassoid amphipod Stephonyx biscayensis at varying temperature to acute pressure exposure by measuring the rate of oxygen consumption. Acclimation to atmospheric pressure is shown to have no significant interaction with temperature and/or pressure effects. Similarly, starvation is shown to have no significant effect on the interaction of temperature and pressure. Subsequently, the effect of pressure on respiration rate is revealed to be dependent on temperature: pressure equivalent to 2000 m depth was tolerated at 1 and 3°C; pressure equivalent to 2500 m depth was tolerated at 5.5°C; at 10°C pressure equivalent to 3000 m depth was tolerated. The variation in tolerance is consistent with the natural distribution range reported for this species. There are clear implications for hypotheses relating to the observed phenomenon of a biodiversity bottleneck between 2000 and 3000 metres, and for the potential for bathymetric range shifts in response to global climate change. PMID:22174838

  9. Sequestration of zinc from zinc oxide nanoparticles and life cycle effects in the sediment dweller amphipod Corophium volutator.

    PubMed

    Fabrega, Julia; Tantra, Ratna; Amer, Aisha; Stolpe, Bjorn; Tomkins, Jordan; Fry, Tony; Lead, Jamie R; Tyler, Charles R; Galloway, Tamara S

    2012-01-17

    We studied the effects of ZnO nanoparticles [ZnO NPs, primary particle size 35 ± 10 nm (circular diameter, TEM)], bulk [160 ± 81 nm (circular diameter, TEM)], and Zn ions (from ZnCl(2)) on mortality, growth, and reproductive endpoints in the sediment dwelling marine amphipod Corophium volutator over a complete lifecycle (100 days). ZnO NPs were characterized by size, aggregation, morphology, dissolution, and surface properties. ZnO NPs underwent aggregation and partial dissolution in the seawater exposure medium, resulting in a size distribution that ranged in size from discrete nanoparticles to the largest aggregate of several micrometers. Exposure via water to all forms of zinc in the range of 0.2-1.0 mg L(-1) delayed growth and affected the reproductive outcome of the exposed populations. STEM-EDX analysis was used to characterize insoluble zinc precipitates (sphaerites) of high sulfur content, which accumulated in the hepatopancreas following exposures. The elemental composition of the sphaerites did not differ for ZnO NP, Zn(2+), and bulk ZnO exposed organisms. These results provide an illustration of the comparable toxicity of Zn in bulk, soluble, and nanoscale forms on critical lifecycle parameters in a sediment dwelling organism. PMID:22191541

  10. Toxicokinetic and toxicodynamic model for diazinon toxicity--mechanistic explanation of differences in the sensitivity of Daphnia magna and Gammarus pulex.

    PubMed

    Kretschmann, Andreas; Ashauer, Roman; Hollender, Juliane; Escher, Beate I

    2012-09-01

    A mechanistic toxicokinetic and toxicodynamic model for acute toxic effects (immobilization, mortality) of the organothiophosphate insecticide diazinon in Daphnia magna is presented. The model was parameterized using measured external and internal (whole-body) concentrations of diazinon, its toxic metabolite diazoxon, and the inactive metabolite 2-isopropyl-6-methyl-4-pyrimidinol, plus acetylcholinesterase (AChE) activity measured during exposure to diazinon in vivo. The toxicokinetic and toxicodynamic model provides a coherent picture from exposure to the resulting toxic effect on an organism level through internally formed metabolites and the effect on a molecular scale. A very fast reaction of diazoxon with AChE (pseudo first-order inhibition rate constant k(i) = 3.3 h(-1)) compared with a slow formation of diazoxon (activation rate constant k(act) = 0.014 h(-1)) was responsible for the high sensitivity of D. magna toward diazinon. Recovery of AChE activity from inhibition was slow and rate-determining (99% recovery within 16 d), compared with a fast elimination of diazinon (99% elimination within 17 h). The obtained model parameters were compared with toxicokinetic and toxicodynamic parameters of Gammarus pulex exposed to diazinon from previous work. This comparison revealed that G. pulex is less sensitive because of a six times faster detoxification of diazinon and diazoxon and an approximately 400 times lower rate for damage accrual. These differences overcompensate the two times faster activation of diazinon to diazoxon in G. pulex compared to D. magna. The present study substantiates theoretical considerations that mechanistically based effect models are helpful to explain sensitivity differences among different aquatic invertebrates. PMID:22653849

  11. A comparison of the structure of American (Homarus americanus) and European (Homarus gammarus) lobster cuticle with particular reference to shell disease susceptibility.

    PubMed

    Davies, Charlotte E; Whitten, Miranda M A; Kim, Anita; Wootton, Emma C; Maffeis, Thierry G G; Tlusty, Michael; Vogan, Claire L; Rowley, Andrew F

    2014-03-01

    The integument of arthropods is an important first-line defence against the invasion of parasites and pathogens. Once damaged, this can be subject to colonisation by microbial agents from the surrounding environment, which in crustaceans can lead to a condition termed shell disease syndrome. This condition has been reported in several crustacean species, including crabs and lobsters. The syndrome is a progressive condition where the outer cuticle becomes pitted and eroded, and in extreme cases is compromised, leaving animals susceptible to septicaemia. This study examined the susceptibility of juvenile American (Homarus americanus) and European (Homarus gammarus) lobsters to shell disease, as a result of mechanical damage. Scanning electron microscopy was used as a method to identify differences in the cuticle structure and consequences of mechanical damage. Claw regions were aseptically punctured, whilst carapaces were abraded using sterile sandpaper, to mimic natural damage. After a period of between 10 and 12 weeks, lobsters were sacrificed, fixed and stored for later examination. The carapace and claws of juvenile American lobsters were shown to be thinner and more vulnerable to abrasion damage than their European counterparts. In addition, the number and distribution of setal pits and pore canal openings also differed between the two species of lobster. Mechanical damage resulted in the formation of shell disease lesions on the claw and carapace of both lobster species. However, American lobsters, unlike their European counterparts, had extensive bacterial colonisation on the margins of these lesions. Overall, it is concluded that the cuticle of the American lobster is more susceptible to damage and resulting microbial colonisation. This may have implications for susceptibility of both species of lobster to shell disease syndrome. PMID:24468664

  12. Strategies of Gammarus pulex L. to cope with arsenic--Results from speciation analyses by IC-ICP-MS and XAS micro-mapping.

    PubMed

    Schaller, Jörg; Koch, Iris; Caumette, Guilhem; Nearing, Michelle; Reimer, Kenneth J; Planer-Friedrich, Britta

    2015-10-15

    The invertebrate shredder Gammarus pulex L. is a key species for aquatic carbon turnover via litter decomposition and can thrive in high-arsenic (As) environments. To understand their strategies for coping with increased As concentrations while fulfilling their ecosystem functions, we analyzed the As concentration and speciation in their aquatic habitat and in leaves with heterotrophic biofilms as their natural food source. We also followed the As distribution and speciation on the cuticle and within the body of G. pulex by X-ray absorption spectroscopic imaging. Half of the total As on G. pulex was found to be associated with the cuticle but was not taken up. Removing this externally bound As yielded only arsenate in the wash solution which reflects the speciation of the surrounding aquatic phase and shows that this As does not undergo any biotransformation. The major pathway into the organism is suggested to be incorporation via food intake, but only very low amounts of As were taken up or translocated from the gut system to other tissues. In one of the main food sources, leaves, 68% arsenate and 29% monomethylarsenate were found. After ingestion into the gut system, up to 23% of the more toxic arsenite was seen, but a substantial share was methylated to dimethylarsenate (46-56%). Little arsenate and arsenite were found in the adjacent tissues. Besides 76-80% mono- and di-methylarsenate, 10-21% of the As was complexed as As(III)-S species. G. pulex plays an important role in As cycling and our results indicate that As translocation from the gut to other tissues is minimized, but a transformation to other As-species occurred. PMID:26068228

  13. The reaction of European lobster larvae (Homarus gammarus) to different quality food: effects of ontogenetic shifts and pre-feeding history.

    PubMed

    Schoo, Katherina L; Aberle, Nicole; Malzahn, Arne M; Schmalenbach, Isabel; Boersma, Maarten

    2014-02-01

    Young larval stages of many organisms represent bottlenecks in the life-history of many species. The high mortality commonly observed in, for example, decapod larvae has often been linked to poor nutrition, with most studies focussing on food quantity. Here, we focus instead on the effects of quality and have investigated its effects on the nutritional condition of lobster larvae. We established a tri-trophic food chain consisting of the cryptophyte Rhodomonas salina, the calanoid copepod Acartia tonsa and larvae of the European lobster Homarus gammarus. In a set of experiments, we manipulated the C:N:P stoichiometry of the primary producers, and accordingly those of the primary consumer. In a first experiment, R. salina was grown under N- and P-limitation and the nutrient content of the algae was manipulated by addition of the limiting nutrient to create a food quality gradient. In a second experiment, the effect on lobster larvae of long- and short-term exposure to food of varying quality during ontogenetic development was investigated. The condition of the lobster larvae was negatively affected even by subtle N- and P-nutrient limitations of the algae. Furthermore, younger lobster larvae were more vulnerable to nutrient limitation than older ones, suggesting an ontogenetic shift in the capacity of lobster larvae to cope with low quality food. The results presented here might have substantial consequences for the survival of lobster larvae in the field, as, in the light of future climate change and re-oligotrophication of the North Sea, lobster larvae might face marked changes in temperature and nutrient conditions, thus significantly altering their condition and growth. PMID:24072442

  14. Benthic control freaks: Effects of the tubiculous amphipod Haploops nirae on the specific diversity and functional structure of benthic communities

    NASA Astrophysics Data System (ADS)

    Rigolet, Carinne; Dubois, Stanislas F.; Thiébaut, Eric

    2014-01-01

    Haploops nirae is a gregarious tubiculous amphipod which extended its habitat over thousands of hectares in shallow waters of South Brittany bays (Bay of Biscay, Atlantic) over the last decades and created uniquely large and dense tube mats. In the bay of Concarneau, we investigated the specific diversity (i.e. species richness and species composition) and the functional structure (using biological traits) of the macrofauna associated with this Haploops community as a comparison with several surrounding soft-sediment communities to determine the effect of this engineer species on ecosystem functions. We showed that the occurrence of Haploops tubes and individuals significantly modifies sediment features (e.g. change in sediment grain size, increase in C and N organic content) but also largely affect species diversity and benthic composition. The species richness was significantly higher in Haploops community but the species assemblage associated with Haploops habitat was very homogeneous compared to the neighboring habitats and unique with 33% of all species exclusively found in this community. Multivariate analysis (dbRDA) revealed that Haploops density was by far the factor explaining the variation in species composition of benthic communities. No differences in species diversity and assemblage were detected in relationship to Haploops density. A biological trait analysis performed on the whole ecosystem (Haploops included) revealed that Haploops largely dominates the functional structure of the Haploops community by its own functional traits. When performed on selected traits of the associated fauna only (Haploops excluded) the functional structure of the Haploops community was characterized by a greatly reduced proportion of small to medium long lived, sensitive to disturbance, free living or burrowing/tube-building filter-feeding species. H. nirae appears to be a bioengineer and a foundation species that largely modifies its hydro-sedimentary features

  15. The life cycle of Sclerocollum saudii Al-Jahdali, 2010 (Acanthocephala: Palaeacanthocephala: Rhadinorhynchidae) in amphipod and fish hosts from the Red Sea.

    PubMed

    Al-Jahdali, M O; Hassanine, R M El-Said; Touliabah, H El-S

    2015-05-01

    The rhadinorhynchid Sclerocollum saudii Al-Jahdali, 2010 was found in the intestine of its type host, Siganus rivulatus Forsskål & Niebuhr, 1775, a siganid fish permanently resident in a lagoon within the mangrove swamps found on the Egyptian coast of the Gulf of Aqaba (between 28°7'N and 28°18'N). Larval forms of this acanthocephalan (acanthors, acanthellae and cystacanths) were only found in Megaluropus agilis Hoek, 1889 (Crustacea: Gammaridae), a benthic amphipod abundant on algae and seagrasses in the lagoon. So, this life cycle of S. saudii was elucidated under semi-natural conditions: embryonated eggs of S. saudii were directly ingested by the amphipod and hatched in its intestine; the released acanthor penetrated the intestinal epithelium in 12-18 h to reach the connective tissue serosa, where it remained for about 3 days, then penetrated the intestinal wall and remained attached to its outer surface for 4 days. It then detached and dropped free in the amphipod haemocoel and transformed into an oval acanthella, growing for 16 days to reach the cystacanth stage. The cystacanth at 46 days post-infection was infective to fish (excysted in its intestine as an active juvenile). Male and female juveniles reached maturity 17 and 23 days post-infection. Recently copulated females first appeared 26 days post-infection and all females seemed to be copulated at 28 days post-infection; partially and fully gravid females first appeared 31 and 35 days post-infection. Mature males and fully gravid females started to die off naturally 31 and 43 days post-infection and were totally expelled from the fish intestine by 42 and 52 days post-infection. The cycle was completed in 89 days and is similar to other known palaeacanthocephalan life cycles, but has its own characteristics. PMID:24565051

  16. Dietary assimilation of cadmium associated with bacterial exopolymer sediment coatings by the estuarine amphipod Leptocheirus plumulosus: Effects of Cd concentration and salinity

    USGS Publications Warehouse

    Schlekat, C.E.; Decho, Alan W.; Chandler, G.T.

    1999-01-01

    Bacterial extracellular substances (also known as exopolysaccharides, or EPS) may serve as vectors for trophic transfer of metals in benthic systems because these ubiquitous sediment coatings can sorb high concentrations of toxic metals, and because many benthic invertebrates assimilate EPS sediment coatings upon ingestion. We conducted 3 sets of experiments to determine the assimilative bioavailability of EPS-associated Cd to the benthic amphipod Leptocheirus plumulosus as a function of Cd concentration and salinity. Bioavailability was measured as L. plumulosus Cd assimilation efficiency (AE) from EPS-coated silica (EPS-Si) and from uncoated silica (NC-Si) using modified pulse-chase methods with the gamma-emitting radioisotope 109Cd. Cd AE was significantly greater from NC-Si than from EPS-Si at 7.5???, but not at 2.5 or 25???. Overall, Cd AE from EPS-Si was between 15.1 and 21.5%. Because EPS-Si sorbed more Cd than NC-Si, EPS coatings magnified the amount of Cd amphipods accumulated at each salinity by up to a factor of 10. Salinity did not directly affect Cd AE from EPS-Si, but because Cd-EPS partitioning increased with decreasing salinity, amphipods accumulated more Cd from EPS at the lowest Cd-EPS incubation salinity (2.5 ???) than at higher salinities (7.5 and 25 ???). Finally, Cd concentration in EPS exhibited an inverse relationship with Cd AE at 2.5 ???, but not at 25 ???. Specifically, Cd AE was 12 times greater at 1 compared with 10 ??g Cd ??g-1 EPS. Together, these results show that estuarine benthos can accumulate Cd from EPS sediment coatings, but that the degree to which this phenomenon occurs is dependent upon seawater salinity and Cd concentration in EPS.

  17. Intra-plant differences in seaweed nutritional quality and chemical defenses: Importance for the feeding behavior of the intertidal amphipod Orchestoidea tuberculata

    NASA Astrophysics Data System (ADS)

    Duarte, Cristian; Acuña, Karin; Navarro, Jorge M.; Gómez, Iván

    2011-10-01

    As a result of their morphological complexity, large macroalgae show intra-thallus variations in their nutritional composition and secondary metabolite content, which influences the trophic ecology of herbivorous invertebrates, and ultimately their fitness. In this study, we evaluated for the first time the variability in nutritional quality (protein content, carbohydrates, lipids, and total organic matter), secondary metabolites (phlorotannins), and structure (shape and toughness) between blades and stipes of the macroalgae Durvillaea Antarctica. Specifically, we looked at their effect on feeding preference, rate of consumption, absorption efficiency, and growth rate of the amphipod Orchestoidea tuberculata, one of the most abundant organisms on Chilean sandy beaches. Proteins, carbohydrates, total organic matter and phlorotannin contents were significantly higher in blades than in stipes. Preference experiments revealed that the amphipods preferred blades when fresh pieces of blades and stipes were offered at the same time. Similar results were found when artificial food (in which structures of both parts of the alga were standardized) was offered, suggesting that shape and toughness of the two different parts of the alga did not influence preference patterns of O. tuberculata. Absorption efficiency of O. tuberculata was higher on blades compared to stipes. When the amphipods were kept with each of the algal parts separately (i.e. no choice), they consumed a significantly higher amount of stipe, which suggests that O. tuberculata used food quantity to compensate for the lower nutritional quality of stipes. The higher nutritional values of blades compared to stipes appears to explain observed preference patterns by O. tuberculata. Phlorotannin content did not appear to inhibit blade consumption, suggesting that the nutritional quality of the food could be more important than chemical defense in determining food choice in O. tuberculata. Growth did not differ

  18. Isolation and Characterization of Microsatellite DNA Markers in the Deep-Sea Amphipod Paralicella tenuipes by Illumina MiSeq Sequencing.

    PubMed

    Ritchie, Heather; Jamieson, Alan J; Piertney, Stuart B

    2016-07-01

    Here, we describe the development of 16 polymorphic microsatellite markers using an Illumina MiSeq sequencing approach in the deep-sea amphipod Paralicella tenuipes A total of 25 577 844 DNA sequences were filtered for microsatellite motifs of which 197 873 sequences were identified. From these sequences, 64 had sufficient flanking regions for primer design and 16 of these loci were polymorphic. Between 5 and 30 alleles were detected per locus, with an average of 13.63 alleles per locus, across a total of 120 individuals from 5 separate deep sea trenches from the Pacific Ocean. For the 16 loci, observed and expected heterozygosity values ranged from 0.116 to 0.414 and 0.422 to 0.820, respectively, with one locus displaying significant deviation from Hardy-Weinberg equilibrium. The microsatellite loci that have been isolated and described here are the first molecular markers developed for deep sea amphipods and will be invaluable for elucidating the genetic population structure and the extent of connectivity between deep ocean trenches. PMID:27012615

  19. Phenotypic and phylogenetic evidence for the role of food and habitat in the assembly of communities of marine amphipods.

    PubMed

    Best, Rebecca J; Stachowicz, John J

    2014-03-01

    The study of community assembly processes currently involves (a) longstanding questions about the relative importance of environmental filtering vs. niche partitioning in a wide range of ecosystems, and (b) more recent questions about methodology. The rapidly growing field of community phylogenetics has generated debate about the choice between functional traits and phylogenetic relationships for understanding species similarities, and has raised additional questions about the contribution of experimental vs. observational approaches to understanding evolutionary constraints on community assembly. In this study, we use traits, a phylogeny, and field surveys to identify the forces structuring communities of herbivorous marine amphipods and isopods living in adjacent seagrass and macroalgae. In addition, we compare our field results to a recently published mesocosm experiment that tested the effects of both trait and phylogenetic diversity on coexistence using the same species and system. With respect to community assembly processes, we found that environmental filtering was the dominant process in macroalgae habitats, that niche partitioning was the dominant process in seagrass habitats, and that the strength of these assembly mechanisms varied with seasonal fluctuations in environmental conditions and resource availability. These patterns are indicated by both phylogenetic relationships and trait distances, but the type of resources being partitioned in seagrass habitats can only be deciphered using trait data. Species coexisting in seagrass in the field differed not in their feeding niche but in traits related to microhabitat use, providing novel evidence of the relative importance of competition for food vs. habitat in structuring communities of phytophagous invertebrates. With respect to methodology, the results for seagrass habitats conflict with those obtained in mesocosms, where feeding trait diversity did promote coexistence and phylogenetic diversity had no

  20. Population structure of Abyssorchomene abyssorum (Stebbing, 1888) (Amphipoda: Lysianassoidea), a scavenging amphipod from the Mid-Atlantic Ridge in the vicinity of the Charlie-Gibbs Fracture Zone

    NASA Astrophysics Data System (ADS)

    Duffy, Grant A.; Horton, Tammy; Sheader, Martin; Thurston, Michael H.

    2013-12-01

    This study focussed on the common and ubiquitous scavenging amphipod Abyssorchomene abyssorum collected from a section of the Mid-Atlantic Ridge with one pair of sampling areas at 49°N and the other at 54°N, north and south of the Charlie Gibbs Fracture Zone (CGFZ) and east and west of the ridge, at a water depth of 2500 m. Baited-trap samples of necrophagous amphipods were collected during three research expeditions on the RRS James Cook in 2007, 2009, and 2010, allowing for direct comparisons to be made amongst populations of A. abyssorum at the four sample areas. Random subsamples of 200 individuals from nine trap samples were sexed, dissected, and measured. Males, females, and juveniles were found in all samples but no ovigerous females were identified. The finding of sexually mature mid-sized females, variability of oocyte size with body size, and presence of mature females with ‘empty’ ovaries, suggest that A. abyssorum is capable of having multiple broods in a lifetime. This reproductive strategy is beneficial to a scavenging organism living under a variable and unpredictable nutrient regime, allowing for a rapid reproductive response to advantageous conditions. Females north and south of the CGFZ fall into distinct cohorts with different distributional parameters. The total body lengths of female cohorts south of the CGFZ were consistently larger than those in the north. This is likely due to increased nutrient availability at the southern sampling areas. Males were significantly smaller than females and possessed longer, more articulate antennae. Longer antennae are thought to facilitate mate-searching by males. Estimates of the maximum brood size ranged from 36-78 offspring with actual brood size expected to be at the lower end of this scale. This places the estimated brood size of A. abyssorum in a similar range to that of other scavenging amphipods of comparable size. The juvenile:non-juvenile ratio differed north and south of the CGFZ with

  1. Reproductive bionomics and life history traits of three gammaridean amphipods, Cymadusa filosa Savigny, Ampithoe laxipodus Appadoo and Myers and Mallacoota schellenbergi Ledoyer from the tropical Indian Ocean (Mauritius)

    NASA Astrophysics Data System (ADS)

    Appadoo, Chandani; Myers, Alan A.

    2004-12-01

    The reproductive bionomics and life history traits of two corophiid amphipods ( Ampithoe laxipodus, Cymadusa filosa) and one melitid ( Mallacoota schellenbergi) were studied in Mauritius (Indian Ocean) for the period March 1999 to February 2000. Results on the population structure, monthly size class variations, sex ratio, female reproductive states and fecundity are presented. The study demonstrates multivoltinism and continuous reproduction in the three species. Increase in number of juveniles was observed in warmer months for C. filosa and A. laxipodus. Sexual maturity was attained at smaller sizes in warmer months in the three species. Linear relationship on body length and number of eggs in brood pouch are presented. Size-independent analysis of egg number revealed a decrease in number of eggs in cooler months. Sex ratio is male skewed in M. schellenbergi and female skewed in C. filosa and A. laxipodus. Some of the plausible explanations for the reproductive strategies adopted by these three species in a tropical system are discussed.

  2. The Panama Canal and the transoceanic dispersal of marine invertebrates: evaluation of the introduced amphipod Paracaprella pusilla Mayer, 1890 in the Pacific Ocean.

    PubMed

    Ros, Macarena; Ashton, Gail V; Lacerda, Mariana B; Carlton, James T; Vázquez-Luis, Maite; Guerra-García, José M; Ruiz, Gregory M

    2014-08-01

    Although the Panama Canal is one of the major corridors for shipping and potential dispersal of marine invaders in the tropics, little is known about the effect that the Canal has had on the distribution of marine biota. In this study, we (a) document the existence of established populations of the Western Atlantic caprellid amphipod Paracaprella pusilla, Mayer, 1890 for the first time at the Pacific entrance to the Canal, (b) review its distribution in the Pacific Ocean, and (c) evaluate possible mechanisms of introduction. The confirmed distribution of P. pusilla in the Pacific Ocean is limited to Australia, Hawaii, and Panama, despite earlier published reports from Chile and China. Laboratory experiments demonstrated intolerance of P. pusilla to freshwater, causing 100% mortality, and suggest invasion of the Pacific coast of Panama occurred through the Canal via ships' ballast water or by secondary spread via ships (ballast water or hull fouling) from another Pacific region. PMID:25060067

  3. Contaminants in stream sediments from seven United States metropolitan areas: part II—sediment toxicity to the amphipod Hyalella azteca and the midge Chironomus dilutus

    USGS Publications Warehouse

    Kemble, Nile E.; Hardesty, Douglas K.; Ingersoll, Christopher G.; Kunz, James L.; Sibley, Paul K.; Calhoun, Daniel L.; Gilliom, Robert J.; Kuivila, Kathryn M.; Nowell, Lisa H.; Moran, Patrick W.

    2013-01-01

    Pyrethroids are hydrophobic compounds that have been observed to accumulate in sediments (Laskowski 2002). Toxicity of pyrethroids in field-collected sediment from small urban streams (Weston et al. 2005; Holmes et al. 2008; Ding et al. 2010; Domagalski et al. 2010) or with pyrethroids spiked into sediment (Amweg et al. 2006; Hintzen et al. 2009) have been evaluated primarily in 10 day lethality tests conducted with the amphipod Hyalella azteca. However, the sublethal effects in long-term exposures to pyrethroids in sediment have not been evaluated, and the distribution of pyrethroids sediments has not typically been evaluated in wadeable streams (Gilliom et al. 2006). This article is the second in a series that describe the results of a study of the distribution and toxicity of pyrethroids and other co-occurring trace elements and organic contaminants (PCBs, PAHs, OC pesticides) in stream sediments from 7 metropolitan areas across the United States (Moran et al. 2012). The study evaluated 98 sediment samples collected from streams ranging from undeveloped to highly urban and differs from previous studies by sampling larger wadeable streams and avoiding point sources (such as storm drains) and other inflows (Gilliom et al. 2006). Part 1 of the series characterizes sediment contaminants in relation to urbanization and other factors in the 7 metropolitan study areas (Nowell et al. 2012). Part 2 (this article) evaluates relationships between sediment chemistry and sediment toxicity in 28 day whole-sediment exposures conducted with the amphipod H. azteca and in 10 day whole-sediment exposure conducted with the midge Chironomus dilutus (USEPA U

  4. Temperature-dependent toxicities of nano zinc oxide to marine diatom, amphipod and fish in relation to its aggregation size and ion dissolution.

    PubMed

    Wong, Stella W Y; Leung, Kenneth M Y

    2014-08-01

    This study, for the first time, concurrently investigated the influence of seawater temperature, exposure concentration and time on the aggregation size and ion dissolution of nano zinc oxides (nZnO) in seawater, and the interacting effect of temperature and waterborne exposure of nZnO to the marine diatom Skeletonema costatum, amphipod Melita longidactyla and fish Oryzias melastigma, respectively. Our results showed that aggregate size was jointly affected by seawater temperature, nZnO concentration and exposure time. Among the three factors, the concentration of nZnO was the most important and followed by exposure time, whereas temperature was less important as reflected by their F values in the three-way analysis of variance (concentration: F3, 300 = 247.305; time: F2, 300 = 20.923 and temperature: F4, 300 = 4.107; All p values <0.001). The aggregate size generally increased with increasing nZnO concentration and exposure time. The release of Zn ions from nZnO was significantly influenced by seawater temperature and exposure time; the ion dissolution rate generally increased with decreasing temperature and increasing exposure time. Growth inhibition of diatoms increased with increasing temperature, while temperature and nZnO had an interactional effect on their photosynthesis. For the amphipod, mortality was positively correlated with temperature. Fish larvae growth rate was only affected by temperature but not nZnO, while the two factors interactively modulated the expression of heat shock and metallothionein proteins. Evidently, temperature can influence aggregate size and ion dissolution and thus toxicity of nZnO to the marine organisms in a species-specific manner. PMID:24219175

  5. Morphological Evolution of Coexisting Amphipod Species Pairs from Sulfidic Caves Suggests Competitive Interactions and Character Displacement, but No Environmental Filtering and Convergence

    PubMed Central

    Fišer, Cene; Luštrik, Roman; Sarbu, Serban; Flot, Jean-François; Trontelj, Peter

    2015-01-01

    Phenotypically similar species coexisting in extreme environments like sulfidic water are subject to two opposing eco-evolutionary processes: those favoring similarity of environment-specific traits, and those promoting differences of traits related to resource use. The former group of processes includes ecological filtering and convergent or parallel evolution, the latter competitive exclusion, character displacement and divergent evolution. We used a unique eco-evolutionary study system composed of two independent pairs of coexisting amphipod species (genus Niphargus) from the sulfidic caves Movile in Romania and Frasassi in Italy to study the relative contribution and interaction of both processes. We looked at the shape of the multifunctional ventral channel as a trait ostensibly related to oxygenation and sulfide detoxification, and at body size as a resource-related trait. Phylogenetic analysis suggests that the sulfidic caves were colonized separately by ancestors of each species. Species within pairs were more dissimilar in their morphology than expected according to a null model based on regional species pool. This might indicate competitive interactions shaping the morphology of these amphipod species. Moreover, our results suggest that the shape of the ventral channel is not subject to long-term convergent selection or to the process of environmental filtering, and as such probably does not play a role in sulfide tolerance. Nevertheless, the ancestral conditions reconstructed using the comparative method tended to be more similar than null-model expectations. This shift in patterns may reflect a temporal hierarchy of eco-evolutionary processes, in which initial environmental filtering became later on superseded by character displacement or other competition-driven divergent evolutionary processes. PMID:25905793

  6. Contrasting patterns in genetic diversity following multiple invasions of fresh and brackish waters.

    PubMed

    Kelly, David W; Muirhead, James R; Heath, Daniel D; Macisaac, Hugh J

    2006-10-01

    Biological invasions may combine the genetic effects of population bottlenecks and selection and thus provide valuable insight into the role of such processes during novel environmental colonizations. However, these processes are also influenced by multiple invasions, the number of individuals introduced and the degree of similarity between source and receiving habitats. The amphipod Gammarus tigrinus provides a useful model to assess these factors, as its invasion history has involved major environmental transitions. This species is native to the northwest Atlantic Ocean, although it invaded both brackish and freshwater habitats in the British Isles after introduction more than 65 years ago. It has also spread to similar habitats in Western Europe and, most recently, to Eastern Europe, the Baltic Sea, and the Laurentian Great Lakes. To examine sources of invasion and patterns of genetic change, we sampled populations from 13 native estuaries and 19 invaded sites and sequenced 542 bp of the mitochondrial COI gene. Strong native phylogeographical structure allowed us to unambiguously identify three allopatrically evolved clades (2.3-3.1% divergent) in invading populations, indicative of multiple introductions. The most divergent clades occurred in the British Isles and mainland Europe and were sourced from the St Lawrence and Chesapeake/Delaware Bay estuaries. A third clade was found in the Great Lakes and sourced to the Hudson River estuary. Despite extensive sampling, G. tigrinus did not occur in freshwater at putative source sites. Some European populations showed reduced genetic diversity consistent with bottlenecks, although selection effects cannot be excluded. The habitat distribution of clades in Europe was congruent with the known invasion history of secondary spread from the British Isles. Differences in salinity tolerance among lineages were suggested by patterns of habitat colonization by different native COI clades. Populations consisting of admixtures

  7. Isolation and characterization of 8 microsatellite loci for the "killer shrimp'', an invasive Ponto-Caspian amphipod Dikerogammarus villosus (Crustacea: Amphipoda).

    PubMed

    Rewicz, Tomasz; Wattier, Rémi A; Rigaud, Thierry; Bacela-Spychalska, Karolina; Grabowski, Michal

    2015-01-01

    Dikerogammarus villosus is a freshwater amphipod of the Ponto-Caspian origin recognized as one of the 100 worst alien species in Europe, having negative impact on biodiversity and functioning of the invaded aquatic ecosystems. The species has a wide ecophysiological tolerance and during the last 20 years it has rapidly spread throughout European inland waters. In consequence, it presents a major conservation management problem. We describe eight polymorphic microsatellite loci developed for D. villosus by combining a biotin-enrichment protocol and new generation 454GS-FLX Titanium pyrosequencing technology. When genotyped in 64 individuals from two locations, the loci exhibited a mean diversity of 4.87 alleles per locus (2-13). The mean observed and expected heterozygosities were, respectively, 0.439 (0.091-0.844) and 0.468 (0.089-0.843). Gametic disequilibrium was not detected for any pair of loci. The microsatellite markers will be a valuable tool in assessing the demographic processes associated with invasion of the killer shrimp from a genetic point of view. PMID:25234651

  8. Relative sensitivity of an amphipod Hyalella azteca, a midge Chironomus dilutus, and a unionid mussel Lampsilis siliquoidea to a toxic sediment

    USGS Publications Warehouse

    Ingersoll, Christopher G.; Kunz, James L.; Hughes, James P.; Wang, Ning; Ireland, D. Scott; Mount, Dave R.; Hockett, Russ J; Valenti, Ted W

    2015-01-01

    The objective of the present study was to evaluate the relative sensitivity of test organisms in exposures to dilutions of a highly toxic sediment contaminated with metals and organic compounds. One dilution series was prepared using control sand (low total organic carbon [TOC; <0.1%, low binding capacity for contaminants]) and a second dilution series was prepared using control sediment from West Bearskin Lake, Minnesota, USA (high TOC [~10% TOC, higher binding capacity for contaminants]). Test organisms included an amphipod (Hyalella azteca; 10-d and 28-d exposures), a midge (Chironomus dilutus; 20-d and 48-d exposures started with <1-h-old larvae, and 13-d and 48-d exposures started with 7-d-old larvae), and a unionid mussel (Lampsilis siliquoidea; 28-d exposures). Relative species sensitivitydepended on the toxicity endpoint and the diluent. All 3 species were more sensitive in sand dilutions than in West Bearskin Lake sediment dilutions. The <1-h-old C. dilutus were more sensitive than 7-d-old C. dilutus, but replicate variability was high in exposures started with the younger midge larvae. Larval biomass and adult emergence endpoints of C. dilutus exhibited a similar sensitivity. Survival, weight, and biomass of H. azteca were more sensitive endpoints in 28-d exposures than in 10-d exposures. Weight and biomass of L. siliquoidea were sensitive endpoints in both sand and West Bearskin Lake sediment dilutions. Metals, ammonia, oil, and other organic contaminants may have contributed to the observed toxicity.

  9. Distribution and respiration of the high-latitude pelagic amphipod Themisto gaudichaudi in the Benguela Current in relation to upwelling intensity

    NASA Astrophysics Data System (ADS)

    Auel, Holger; Ekau, Werner

    2009-12-01

    The cold and highly productive waters of coastal upwelling areas provide habitats for marine species usually occurring at higher latitudes and allow those species to extend their distribution ranges towards the equator into regions otherwise characterised by warm and oligotrophic sub-tropical waters. The pelagic hyperiid amphipod Themisto gaudichaudi has a circum-Antarctic epipelagic distribution pattern generally south of 35°S and plays an important role in Antarctic food webs as effective link from zooplankton secondary production to higher trophic levels including seabirds and marine mammals. In the cold and productive waters of the Benguela Current coastal upwelling system, the distribution range of the species extents far northward into the subtropics. The present study focuses on the distribution of T. gaudichaudi at the northernmost limit of its range in the Benguela upwelling system in relation to upwelling intensity and hydrographic conditions (sea surface temperature) based on time-series data from 2002 to 2008. Moreover, field data on life-history traits and respiration rates in relation to water temperature are combined to elucidate the environmental and physiological factors limiting the distribution range. Compared to Themisto populations from higher latitudes, the relatively higher water temperatures in the coastal upwelling region lead to higher respiration rates, faster growth, earlier sexual maturity and smaller body size.

  10. Morphologically Cryptic Amphipod Species Are “Ecological Clones” at Regional but Not at Local Scale: A Case Study of Four Niphargus Species

    PubMed Central

    Fišer, Žiga; Altermatt, Florian; Zakšek, Valerija; Knapič, Tea; Fišer, Cene

    2015-01-01

    Recent studies indicate that morphologically cryptic species may be ecologically more different than would be predicted from their morphological similarity and phylogenetic relatedness. However, in biodiversity research it often remains unclear whether cryptic species should be treated as ecologically equivalent, or whether detected differences have ecological significance. In this study, we assessed the ecological equivalence of four morphologically cryptic species of the amphipod genus Niphargus. All species live in a small, isolated area on the Istrian Peninsula in the NW Balkans. The distributional ranges of the species are partially overlapping and all species are living in springs. We reconstructed their ecological niches using morphological traits related to feeding, bioclimatic niche envelope and species’ preference for epi-hypogean habitats. The ecological meaning of differences in niches was evaluated using distributional data and co-occurrence frequencies. We show that the species comprise two pairs of sister species. All species differ from each other and the degree of differentiation is not related to phylogenetic relatedness. Moreover, low co-occurrence frequencies in sympatric zones imply present or past interspecific competition. This pattern suggests that species are not differentiated enough to reduce interspecific competition, nor ecologically equivalent to co-exist via neutral dynamics. We tentatively conclude that the question of ecological equivalence relates to the scale of the study: at a fine scale, species’ differences may influence dynamics in a local community, whereas at the regional level these species likely play roughly similar ecological roles. PMID:26226375

  11. Relative sensitivity of an amphipod Hyalella azteca, a midge Chironomus dilutus, and a unionid mussel Lampsilis siliquoidea to a toxic sediment.

    PubMed

    Ingersoll, Chris G; Kunz, James L; Hughes, Jamie P; Wang, Ning; Ireland, D Scott; Mount, David R; Hockett, J Russell; Valenti, Theodore W

    2015-05-01

    The objective of the present study was to evaluate the relative sensitivity of test organisms in exposures to dilutions of a highly toxic sediment contaminated with metals and organic compounds. One dilution series was prepared using control sand (low total organic carbon [TOC; <0.1%, low binding capacity for contaminants]) and a second dilution series was prepared using control sediment from West Bearskin Lake, Minnesota, USA (high TOC [∼10% TOC, higher binding capacity for contaminants]). Test organisms included an amphipod (Hyalella azteca; 10-d and 28-d exposures), a midge (Chironomus dilutus; 20-d and 48-d exposures started with <1-h-old larvae, and 13-d and 48-d exposures started with 7-d-old larvae), and a unionid mussel (Lampsilis siliquoidea; 28-d exposures). Relative species sensitivity depended on the toxicity endpoint and the diluent. All 3 species were more sensitive in sand dilutions than in West Bearskin Lake sediment dilutions. The <1-h-old C. dilutus were more sensitive than 7-d-old C. dilutus, but replicate variability was high in exposures started with the younger midge larvae. Larval biomass and adult emergence endpoints of C. dilutus exhibited a similar sensitivity. Survival, weight, and biomass of H. azteca were more sensitive endpoints in 28-d exposures than in 10-d exposures. Weight and biomass of L. siliquoidea were sensitive endpoints in both sand and West Bearskin Lake sediment dilutions. Metals, ammonia, oil, and other organic contaminants may have contributed to the observed toxicity. PMID:25655578

  12. Toxicity Persistence of Chlorpyrifos in Runoff from Experimental Soybean Plots to the Non-target Amphipod Hyalella curvispina: Effect of Crop Management.

    PubMed

    Mugni, Hernán; Paracampo, Ariel; Demetrio, Pablo; Pardi, Martín; Bulus, Gustavo; Ronco, Alicia; Bonetto, Carlos

    2016-02-01

    Toxicity persistence to the nontarget amphipod Hyalella curvispina in runoff events following chlorpyrifos applications to soy experimental plots was compared in conventional and no-till management. Two application scenarios were compared: an early-season application with the soil almost bare and a late-season application after the foliage had attained complete soil cover. H. curvispina was exposed to chlorpyrifos using two different test systems: a short-term (48 h) runoff water exposure and a long-term (10 days) soil exposure. Both commonly used crop management practices for soybean production resulted in runoff toxicity following pesticide applications and represent a toxicity risk for adjacent inland waters. Toxicity persistence was longer after the earlier than the late season application, likely because of higher volatilization and photodecomposition losses from the soy canopy than from the soil. For the early-season application, toxicity persisted longer in the no-till plots than in the conventional tillage plots. Suspended matter was higher in the conventional treatment. Chlorpyrifos sorption to suspended matter likely contributed to the shorter persistence. For the late-season application, toxicity persisted longer in the conventional treatment. The causes remain conjectural. The soil organic carbon content was higher in the no-till treatment. Sorption to organic matter might have contributed to the shorter chlorpyrifos toxicity persistence in no-till management. Late applications are more frequent and prevail longer throughout the soy growing season. Overall, the no-till management practice seems preferably because shorter toxicity persistence in runoff represents a lower environmental risk for the adjacent inland waters. PMID:26142121

  13. Genetic and morphological divergences in the cosmopolitan deep-sea amphipod Eurythenes gryllus reveal a diverse abyss and a bipolar species.

    PubMed

    Havermans, Charlotte; Sonet, Gontran; d'Udekem d'Acoz, Cédric; Nagy, Zoltán T; Martin, Patrick; Brix, Saskia; Riehl, Torben; Agrawal, Shobhit; Held, Christoph

    2013-01-01

    Eurythenes gryllus is one of the most widespread amphipod species, occurring in every ocean with a depth range covering the bathyal, abyssal and hadal zones. Previous studies, however, indicated the existence of several genetically and morphologically divergent lineages, questioning the assumption of its cosmopolitan and eurybathic distribution. For the first time, its genetic diversity was explored at the global scale (Arctic, Atlantic, Pacific and Southern oceans) by analyzing nuclear (28S rDNA) and mitochondrial (COI, 16S rDNA) sequence data using various species delimitation methods in a phylogeographic context. Nine putative species-level clades were identified within E. gryllus. A clear distinction was observed between samples collected at bathyal versus abyssal depths, with a genetic break occurring around 3,000 m. Two bathyal and two abyssal lineages showed a widespread distribution, while five other abyssal lineages each seemed to be restricted to a single ocean basin. The observed higher diversity in the abyss compared to the bathyal zone stands in contrast to the depth-differentiation hypothesis. Our results indicate that, despite the more uniform environment of the abyss and its presumed lack of obvious isolating barriers, abyssal populations might be more likely to show population differentiation and undergo speciation events than previously assumed. Potential factors influencing species' origins and distributions, such as hydrostatic pressure, are discussed. In addition, morphological findings coincided with the molecular clades. Of all specimens available for examination, those of the bipolar bathyal clade seemed the most similar to the 'true' E. gryllus. We present the first molecular evidence for a bipolar distribution in a macro-benthic deep-sea organism. PMID:24086322

  14. Shifts in the diets of slimy sculpin (Cottus cognatus) and lake whitefish (Coregonus clupeaformis) in Lake Ontario following the collapse of the burrowing amphipod Diporeia

    USGS Publications Warehouse

    Owens, Randall W.; Dittman, Dawn E.

    2003-01-01

    In Lake Ontario, the diets of slimy sculpin Cottus cognatus and lake whitefish Coregonus clupeaformis shifted from a diet dominated by the burrowing amphipod, Diporeia, and to a lesser extent, Mysis, to a more diverse diet, after Diporeia collapsed, to one dominated by Mysis and prey that were formerly less important or uncommon such as Chironomidae, Oligochaeta, and Ostracoda. Additionally, lake whitefish still preyed on native mollusks like Sphaeriidae and Gastropoda, but also preyed on exotic mollusks, Dreissena spp., which are swallowed intact and subsequently crushed in its muscular stomach. Whether Diporeia was abundant (1992) or scarce (1999), selection indices for Diporeia by slimy sculpins was positive, suggesting that Diporeia was a preferred prey. Unlike lake whitefish, slimy sculpins avoided Dreissena; therefore, energy diverted to Dreissena production was a real loss for slimy sculpins. The shifts in the diet of these benthic fishes corresponded with drastic changes in the benthic community between 1992 and 1999. The collapse of Diporeia, formerly the most abundant macroinvertebrate in the benthic community, along with sharp declines in the abundance of Oligochaeta and Sphaeriidae, coincided with the establishment and rapid expansion of Dreissena bugensis, the quagga mussel, and to a lesser degree Dreissena polymorpha, the zebra mussel. It appears that the Diporeia population first collapsed at depths >70 m in southeastern Lake Ontario by autumn 1992, at shallower depths in the eastern Lake Ontario by 1995, and along the entire south shore line at depths 100 m by 1999. In response to the disappearance of Diporeia, populations of two native benthivores, slimy sculpin and lake whitefish, collapsed in eastern Lake Ontario, perhaps due in part to starvation, because Diporeia was their principal prey. Presently, alternative food resources do not appear sufficient to sustain these two benthivores at their former levels of abundance. We do not expect slimy

  15. Genetic and Morphological Divergences in the Cosmopolitan Deep-Sea Amphipod Eurythenes gryllus Reveal a Diverse Abyss and a Bipolar Species

    PubMed Central

    Havermans, Charlotte; Sonet, Gontran; d’Udekem d’Acoz, Cédric; Nagy, Zoltán T.; Martin, Patrick; Brix, Saskia; Riehl, Torben; Agrawal, Shobhit; Held, Christoph

    2013-01-01

    Eurythenes gryllus is one of the most widespread amphipod species, occurring in every ocean with a depth range covering the bathyal, abyssal and hadal zones. Previous studies, however, indicated the existence of several genetically and morphologically divergent lineages, questioning the assumption of its cosmopolitan and eurybathic distribution. For the first time, its genetic diversity was explored at the global scale (Arctic, Atlantic, Pacific and Southern oceans) by analyzing nuclear (28S rDNA) and mitochondrial (COI, 16S rDNA) sequence data using various species delimitation methods in a phylogeographic context. Nine putative species-level clades were identified within E. gryllus. A clear distinction was observed between samples collected at bathyal versus abyssal depths, with a genetic break occurring around 3,000 m. Two bathyal and two abyssal lineages showed a widespread distribution, while five other abyssal lineages each seemed to be restricted to a single ocean basin. The observed higher diversity in the abyss compared to the bathyal zone stands in contrast to the depth-differentiation hypothesis. Our results indicate that, despite the more uniform environment of the abyss and its presumed lack of obvious isolating barriers, abyssal populations might be more likely to show population differentiation and undergo speciation events than previously assumed. Potential factors influencing species’ origins and distributions, such as hydrostatic pressure, are discussed. In addition, morphological findings coincided with the molecular clades. Of all specimens available for examination, those of the bipolar bathyal clade seemed the most similar to the ‘true’ E. gryllus. We present the first molecular evidence for a bipolar distribution in a macro-benthic deep-sea organism. PMID:24086322

  16. Mixture toxicity of imidacloprid and cyfluthrin to two non-target species, the fathead minnow Pimephales promelas and the amphipod Hyalella azteca.

    PubMed

    Lanteigne, Michelle; Whiting, Sara A; Lydy, Michael J

    2015-02-01

    Two species, the fathead minnow Pimephales promelas and the amphipod Hyalella azteca, were tested to examine acute toxicity to two insecticides, cyfluthrin and imidacloprid individually and as a mixture. Cyfluthrin was acutely toxic to P. promelas and H. azteca with EC50 values and 95 % confidence intervals of 0.31 µg L(-1) (0.26-0.35 µg L(-1)) and 0.0015 µg L(-1) (0.0011-0.0018 µg L(-1)), respectively. Imidacloprid was not acutely toxic to P. promelas at water concentrations ranging from 1 to 5000 µg L(-1), whereas it was toxic to H. azteca with a EC50 value of 33.5 µg L(-1) (23.3-47.4 µg L(-1)). For the P. promelas mixture test, imidacloprid was added at a single concentration to a geometric series of cyfluthrin concentrations bracketing the EC50 value. A synergistic ratio (SR) of 1.9 was found for P. promelas, which was calculated using the cyfluthrin-only exposure and mixture-exposure data. Because cyfluthrin and imidacloprid were toxic to H. azteca, the mixture test was designed based on an equipotent toxic unit method. Results from the mixture test indicated a model deviation ratio (MDR) of 1.7 or 2.7 depending on the model. Mixture test results from the simultaneous exposure to cyfluthrin and imidacloprid with both species indicated a greater than expected toxic response because the SR or MDR values were >1. Because these two insecticides are commonly used together in the same product formulations, nontarget species could be more affected due to their greater-than-additive toxicity observed in the current study. PMID:25298152

  17. A new species of the subterranean amphipod genus Stygobromus (Amphipoda: Crangonyctidae) from two caves and a spring in western Maryland, USA with additional records of undescribed species from groundwater habitats in central Maryland.

    PubMed

    Holsinger, John R; Ansell, Lynnette

    2014-01-01

    A new species of the subterranean amphipod genus Stygobromus is described from two caves and a small spring on the Appalachian Plateau in Garrett County in western Maryland, USA. The description of this species brings to six the total number of species in the genus Stygobromus from the state of Maryland. The other five species are recorded from shallow groundwater habitats (e.g., seeps and springs) in the eastern and southeastern parts of the state. In addition, at least four new species of Stygobromus from central Maryland are recognized but remain undescribed to date. PMID:24871182

  18. Zur Ökophysiologie, Sexualität und Populationsgenetik litoraler Gammaridea — ein Überblick

    NASA Astrophysics Data System (ADS)

    Bulnheim, H.-P.

    1991-09-01

    Comparative investigations on the physiological capacities in the euryhaline amphipods Gammarus locusta, G. oceanicus, G. salinus, G. zaddachi and G. duebeni were reviewed. In order to assess the adaptations of these species to the abiotic conditions of their environment, the following criteria were examined: oxygen consumption in relation to ambient salinity and temperature levels, respiratory responses following osmotic stress, resistance capacities to oxygen deficiency, resistance to aerial exposure and the simultaneous presence of hydrogen sulphide. Covering the range from marine to typically brackish-water inhabitants, the 5 species show adaptive responses in the above-mentioned order. Respiration is less intensely modified by external factors, and oxygen consumption decreases. Accompanied by faster rates of acclimation to new steady states of performance, resistance capacities increase. The significance of the findings obtained is discussed in relation to the environmental requirements of the amphipods considered. Based on breeding experiments, the sex-determining systems reported thus far in Gammarus species are outlined. As demonstrated in G. duebeni, a more or less pronounced influence of external factors such as photoperiod may become effective. A preponderance of males was noted when offspring were raised under long-day photoperiods, whereas females prevailed under short-day conditions. In terms of the critical daylength, the light per day was estimated as being between 13 and 14 h (Elbe estuary population). Feminizing microporidians ( Octosporea effeminans, Thelohania herediteria), which are transovarially transmitted, can interfere with the system of sex determination and sex differentiation of the host. As reflected in various G. duebeni populations, they cause a maternally transferred sex-ratio condition by the production of all-female broods, thereby mimicking extrachromosomal inheritance. An increase of the salinity level to 25 30‰ results in a

  19. Cell lineage analysis of the mandibular segment of the amphipod Orchestia cavimana reveals that the crustacean paragnaths are sternal outgrowths and not limbs.

    PubMed

    Wolff, Carsten; Scholtz, Gerhard

    2006-01-01

    The question of arthropod head segmentation has become one of the central issues in Evolutionary Developmental Biology. The number of theories pertaining to head segments progressively enlarges, old concepts have been revitalized, and nearly every conceivable composition of the arthropod head has at some point received discussion. One contentious issue involves a characteristic mouthpart in crustaceans--the lower lips or the so-called paragnaths. The paragnaths build the posterior border of the mouth region antagonistic to the upper lip--the labrum. We show here the development of the appendage-like structures in the mandibular region of the amphipod crustacean Orchestia cavimana at a high level of cellular resolution. The embryos are examined during development of the mouthparts using in vivo labeling. An invariant cell division pattern of the mandibular segment was detected by 4D-microscopy and a preliminary model for pattern of the first cleavages in the mandibular region created. With this indispensable precondition single ectodermal cells of the grid-like pattern were labeled with DiI--a lipophilic fluorescent dye--to trace cell lineages and determine the clonal composition of the developing mouthparts, especially the mandibular segment. From our data it is evident that the paragnaths are sternal outgrowths of the mandible segment. The assumption of the limb nature of paragnaths and the presence of an additional head segment between the mandibular and the second antennal segments are clearly refuted by our data. Our results show the power of cell lineage and clonal analyses for inferences on the nature, origin and thus homology of morphological structures. With this kind of investigation morphological and gene expression data can be complemented. We discuss notable similarities of paragnath anlagen to those of the hypopharynx complex in myriapods and hexapods. The fact that both structures grow out as two lateral buds in the same region of the mandibular

  20. TOXICITY AND BIOACCUMULATION OF CADMIUM AND LEAD IN AQUATIC INVERTEBRATES

    EPA Science Inventory

    Cadmium toxicity and lead toxicity to four species of insects (Pteronarcys dorsata, Hydropsyche betteni, Brachycentrus sp. and Ephemerella sp.) one snail (Physa integra) and one amphipod (Gammarus pseudolimnaeus) were determined during 28-day exposures. The 28-day LC50 values for...

  1. Demonstrating That Habitat Structure Facilitates Coexistence of Prey & Predator: A Laboratory Investigation Using Goldfish & Invertebrates.

    ERIC Educational Resources Information Center

    Stewart, Timothy W.; Embrey, Tracey R.

    2003-01-01

    Presents a laboratory investigation to demonstrate that habitat structure promotes increased organism abundance and species diversity by reducing predator effects on prey abundance. Investigates the effects of goldfish (Carassius auratus) predators on Gammarus sp. (an amphipod) and Daphnia magna (a cladoceran) prey in the absence and presence of a…

  2. Specific Detection and Localization of Microsporidian Parasites in Invertebrate Hosts by Using In Situ Hybridization

    PubMed Central

    Smith, Judith E.; Solter, Leellen; Perotti, M. Alejandra; Braig, Henk R.; Dunn, Alison M.

    2013-01-01

    We designed fluorescence in situ hybridization probes for two distinct microsporidian clades and demonstrated their application in detecting, respectively, Nosema/Vairimorpha and Dictyoceola species. We used them to study the vertical transmission of two microsporidia infecting the amphipod Gammarus duebeni. PMID:23087031

  3. Microsporidian parasites feminise hosts without paramyxean co-infection: support for convergent evolution of parasitic feminisation.

    PubMed

    Ironside, Joseph Edward; Alexander, Jenna

    2015-05-01

    Feminisation of amphipod crustaceans is associated with the presence of at least three microsporidian parasites and one paramyxean parasite, suggesting that the ability to feminise has evolved multiple times in parasites of amphipods. Co-infection by a paramyxean with one of the putative microsporidian feminisers, Dictyocoela duebenum, has inspired the alternative hypothesis that all feminisation of amphipods is caused by paramyxea and that all microsporidian associations with feminisation are due to co-infection with paramyxea (Short et al., 2012). In a population of the amphipod Gammarus duebeni, breeding experiments demonstrate that the microsporidia D. duebenum and Nosema granulosis are associated with feminisation in the absence of paramyxea. Co-infection of the two microsporidia is no more frequent than expected at random and each parasite is associated with feminisation in the absence of the other. These findings support the original hypothesis that the ability to feminise amphipods has evolved in microsporidia on multiple occasions. Additionally, the occurrence of a non-feminising strain of D. duebenum in Gammarus pulex suggests that different strains vary in their feminising ability, even within microsporidian species. The presence or absence of feminising ability in a particular microsporidian strain should not therefore be generalised to the species as a whole. PMID:25747725

  4. PREDICTING TOXICITY TO AMPHIPODS FROM SEDIMENT CHEMISTRY

    EPA Science Inventory

    Background

    The contribution of contaminated sediments to effects on sediment-dwelling organisms (including plants and invertebrates), aquatic-dependent wildlife (amphibians, reptiles, fish, birds, and mammals), and human health has become more apparent in recent yea...

  5. Microsporidia parasites disrupt the responses to cadmium exposure in a gammarid.

    PubMed

    Gismondi, Eric; Rigaud, Thierry; Beisel, Jean-Nicolas; Cossu-Leguille, Carole

    2012-01-01

    Microsporidia parasites are commonly found in amphipods, where they are often asymptomatic, vertically-transmitted and have several effects on host sexuality and behaviour. As amphipods are often used as models in ecotoxicological studies, we investigated the effect of microsporidian infections on energy reserves and defence capacities of Gammarus roeseli under cadmium stress. Only females were infected by two microsporidia parasites: Dictyocoela roeselum or Dictyocoela muelleri. In physiological conditions, microsporidia had no major effect on energy reserves and defence capacities of G. roeseli, while under cadmium exposure, energy reserves and antioxidant defence were weaker in infected females. Moreover, higher malondialdehyde levels detected in infected females revealed that they suffered more cellular damages. Our results suggest that microsporidia may affect gammarid fitness in stressful conditions, when parasitic stress cannot be compensated by the host. Consequently, microsporidia parasites should be a factor necessary to take into account in ecotoxicology studies involving amphipods. PMID:22035920

  6. Direct evidence of the cyclooxygenase pathway of prostaglandin synthesis in arthropods: genetic and biochemical characterization of two crustacean cyclooxygenases.

    PubMed

    Varvas, Külliki; Kurg, Reet; Hansen, Kristella; Järving, Reet; Järving, Ivar; Valmsen, Karin; Lõhelaid, Helike; Samel, Nigulas

    2009-12-01

    Prostaglandins, well-known lipid mediators in vertebrate animals, have also shown to play certain regulatory roles in insects and other arthropods acting on reproduction, immune system and ion transport. However, knowledge of their biosynthetic pathways in arthropods is lacking. In the present study, we report the cloning and expression of cyclooxygenase (COX) from amphipod crustaceans Gammarus spp and Caprella spp. The amphipod COX proteins contain key residues shown to be important for cyclooxygenase and peroxidase activities. Differently from all other known cyclooxygenases the N-terminal signal sequence of amphipod enzymes is not cleaved during protein expression in mammalian cells. The C-terminus of amphipod COX is shorter than that of mammalian isoforms and lacks the KDEL(STEL)-type endoplasmic reticulum retention/retrieval signal. Despite that, amphipod COX proteins are N-glycosylated and locate similarly to the vertebrate COX on the endoplasmic reticulum and nuclear envelope. Both amphipod COX mRNAs encode functional cyclooxygenases that catalyze the transformation of arachidonic acid into prostaglandins. Using bioinformatic analysis we identified a COX-like gene from the human body louse Pediculus humanus corporis genome that encodes a protein with about 30% sequence identity with human COX-1 and COX-2. Although the COX gene is known to be absent from genomes of Drosophila sp., Aedes aegypti, Bombyx mori, and other insects, our studies establish the existence of the COX gene in certain lineages within the insect world. PMID:19854273

  7. Evaluation of toxicity to the amphipod, Hyalella azteca, and to the midge, Chironomus dilutus; and bioaccumulation by the oligochaete, Lumbriculus variegatus, with exposure to PCB-contaminated sediments from Anniston, Alabama

    USGS Publications Warehouse

    Ingersoll, Christopher G.; Steevens, Jeffery A.; MacDonald, Donald D.; Brumbaugh, William G.; Coady, Matthew R.; Farrar, J. Daniel; Lotufo, Guilherme R.; Kemble, Nile E.; Kunz, James L.; Stanley, Jacob K.; Sinclair, Jesse A.

    2014-01-01

    The U.S. Environmental Protection Agency (USEPA) requested that as part of the remedial investigation for the Anniston, Alabama Polychlorinated Biphenyl (PCB) Site (Anniston PCB Site), that Pharmacia Corporation and Solutia Inc. (P/S) perform long-term reproduction toxicity tests with the amphipod, Hyalella azteca, and the midge, Chironomus dilutus, and bioaccumulation tests with the oligochaete, Lumbriculus variegatus, using sediment samples collected from reference locations and from Operable Unit 4 of the Anniston PCB Site. The sediment toxicity testing and sediment bioaccumulation results will be used by ARCADIS U.S., Inc. (ARCADIS) as part of a weight-of-evidence assessment to evaluate risks and establish sediment remediation goals for contaminants to sediment-dwelling organisms inhabiting the Anniston PCB Site. The goal of this study was to characterize relations between sediment chemistry and sediment toxicity and relations between sediment chemistry and sediment bioaccumulation in samples of sediments collected from the Anniston PCB Site. A total of 32 samples were evaluated from six test sites and one reference site to provide a wide range in concentrations of chemicals of potential concern (COPCs) including PCBs in samples of whole sediment. The goal of this study was not to determine the extent of sediment contamination across the Anniston PCB Site. Hence, the test sites or samples collected from within a test site were not selected to represent the spatial extent of sediment contamination across the Anniston PCB Site. Sediment chemistry, pore-water chemistry, and sediment toxicity data were generated for 26 sediment samples from the Anniston PCB Site. All of the samples were evaluated to determine if they qualified as reference sediment samples. Those samples that met the chemical selection criteria and biological selection criteria were identified as reference samples and used to develop the reference envelope for each toxicity test endpoint. Physical

  8. Transcriptional responses to teflubenzuron exposure in European lobster (Homarus gammarus).

    PubMed

    Olsvik, Pål A; Samuelsen, Ole B; Agnalt, Ann-Lisbeth; Lunestad, Bjørn T

    2015-10-01

    Increasing use of pharmaceutical drugs to delouse farmed salmon raises environmental concerns. This study describes an experiment carried out to elucidate the molecular mechanisms of the antiparasitic drug teflubenzuron on a non-target species, the European lobster. Juvenile lobsters (10.3±0.9 mm carapace length) were fed two environmentally relevant doses of teflubenzuron, corresponding to 5 and 20% of a standard salmon medication (10 mg/kg day), termed low and high dose in this study. After 114 days of dietary exposure, whole-animal accumulation of teflubenzuron was determined. One claw from each animal was collected for transcriptional analysis. Overall, exposed animals showed low cumulative mortality. Six animals, two from the low dose treatment and four from the high dose, showed exoskeletal abnormalities (claw deformities or stiff walking legs). Residual levels of teflubenzuron in juvenile lobster were 2.7-fold higher in the high dose (282 ng/g) compared to the low dose treatment (103 ng/g). The transcriptional examination showed significant effects of teflubenzuron on 21 out of 39 studied genes. At the transcriptional level, environmentally relevant levels of the anti-salmon lice drug impacted genes linked to drug detoxification (cyp3a, cyp6a2, cyp302a, sult1b1, abcc4), cellular stress (hsp70, hsp90, chh), oxidative stress (cat, gpx3) and DNA damage (p53), as well as molting and exoskeleton regulation (chi3l1, ecr, jhl1, chs1, ctbs, gap65, jhel-ces1) in claw tissue (muscle and exoskeleton). In conclusion, teflubenzuron at sub-lethal levels can affect many molecular mechanisms in European lobster claws. PMID:26318677

  9. The enemy of my enemy is my friend: intraguild predation between invaders and natives facilitates coexistence with shared invasive prey

    PubMed Central

    MacNeil, Calum; Dick, Jaimie T. A.

    2014-01-01

    Understanding and predicting the outcomes of biological invasions is challenging where multiple invader and native species interact. We hypothesize that antagonistic interactions between invaders and natives could divert their impact on subsequent invasive species, thus facilitating coexistence. From field data, we found that, when existing together in freshwater sites, the native amphipod Gammarus duebeni celticus and a previous invader G. pulex appear to facilitate the establishment of a second invader, their shared prey Crangonyx pseudogracilis. Indeed, the latter species was rarely found at sites where each Gammarus species was present on its own. Experiments indicated that this may be the result of G. d. celticus and G. pulex engaging in more intraguild predation (IGP) than cannibalism; when the ‘enemy’ of either Gammarus species was present, that is, the other Gammarus species, C. pseudogracilis significantly more often escaped predation. Thus, the presence of mutual enemies and the stronger inter- than intraspecific interactions they engage in can facilitate other invaders. With some invasive species such as C. pseudogracilis having no known detrimental effects on native species, and indeed having some positive ecological effects, we also conclude that some invasions could promote biodiversity and ecosystem functioning. PMID:25122739

  10. Interactions among zebra mussel shells, invertebrate prey, and Eurasian ruffe or yellow perch

    USGS Publications Warehouse

    Kolar, C.S.; Fullerton, A.H.; Martin, K.M.; Lamberti, G.A.

    2002-01-01

    The exotic zebra mussel, Dreissena polymorpha, is established in all of the Laurentian Great Lakes and may affect benthivorous fishes by increasing the complexity of benthic substrates and changing energy flow patterns within the food web. Native yellow perch, Perca flavescens, and the nonindigenous Eurasian ruffe, Gymnocephalus cernuus, are benthivores that may compete for limited food resources. As ruffe spread to areas with more dense zebra mussel populations, the zone of interaction among zebra mussels, yellow perch, and ruffe will increase and intensify. In the laboratory, the effect of zebra mussel shells on the ability of these fishes to forage on amphipods (Gammarus pseudolimnaeus) and chironomids (Chironomus plumosus) was examined in light and darkness. In 12 h, ruffe consumed more amphipods than did similar-sized yellow perch, particularly in darkness on bare cobble, and in light within zebra mussels. Amphipods decreased activity more in the presence of ruffe than yellow perch. More amphipods were found in zebra mussel shells than in bare cobble, whether or not fish were present. In darkness, when ruffe consumed more amphipods on bare cobble, amphipods became more associated with zebra mussel shells. Although ruffe consumed more amphipods than yellow perch, perch consumed more chironomids than ruffe on bare cobble. The presence of zebra mussel shells altered the relative consumption of invertebrates in some substrate-light combinations. Experiments such as these help to improve understanding of the direct and indirect effects of predation between and among native and nonindigenous species that may exert structuring forces on the nearshore communities of the Great Lakes currently or in the future.

  11. Short-term bioconcentration studies of Np in freshwater biota

    SciTech Connect

    Poston, T.M.; Klopfer, D.C.; Simmons, M.A. )

    1990-12-01

    Short-term laboratory exposures were conducted to determine the potential accumulation of Np in aquatic organisms. Concentration factors were highest in green algae. Daphnia magna, a filter-feeding crustacean, accumulated Np at levels one order of magnitude greater than the amphipod Gammarus sp., an omnivorous substrate feeder. Accumulation of Np in juvenile rainbow trout (Oncorhynchus mykiss) was highest in carcass (generally greater than 78% of the total body burden) and lowest in fillets. Recommended concentration factors for Np, based on fresh weight, were 300 for green algae, 100 for filter-feeding invertebrates, for nonfilter-feeding invertebrates, 10 for whole fish, and one for fish flesh.

  12. Predicting invasive species impacts: a community module functional response approach reveals context dependencies.

    PubMed

    Paterson, Rachel A; Dick, Jaimie T A; Pritchard, Daniel W; Ennis, Marilyn; Hatcher, Melanie J; Dunn, Alison M

    2015-03-01

    Predatory functional responses play integral roles in predator-prey dynamics, and their assessment promises greater understanding and prediction of the predatory impacts of invasive species. Other interspecific interactions, however, such as parasitism and higher-order predation, have the potential to modify predator-prey interactions and thus the predictive capability of the comparative functional response approach. We used a four-species community module (higher-order predator; focal native or invasive predators; parasites of focal predators; native prey) to compare the predatory functional responses of native Gammarus duebeni celticus and invasive Gammarus pulex amphipods towards three invertebrate prey species (Asellus aquaticus, Simulium spp., Baetis rhodani), thus, quantifying the context dependencies of parasitism and a higher-order fish predator on these functional responses. Our functional response experiments demonstrated that the invasive amphipod had a higher predatory impact (lower handling time) on two of three prey species, which reflects patterns of impact observed in the field. The community module also revealed that parasitism had context-dependent influences, for one prey species, with the potential to further reduce the predatory impact of the invasive amphipod or increase the predatory impact of the native amphipod in the presence of a higher-order fish predator. Partial consumption of prey was similar for both predators and occurred increasingly in the order A. aquaticus, Simulium spp. and B. rhodani. This was associated with increasing prey densities, but showed no context dependencies with parasitism or higher-order fish predator. This study supports the applicability of comparative functional responses as a tool to predict and assess invasive species impacts incorporating multiple context dependencies. PMID:25265905

  13. Predicting invasive species impacts: a community module functional response approach reveals context dependencies

    PubMed Central

    Paterson, Rachel A; Dick, Jaimie T A; Pritchard, Daniel W; Ennis, Marilyn; Hatcher, Melanie J; Dunn, Alison M

    2015-01-01

    Summary Predatory functional responses play integral roles in predator–prey dynamics, and their assessment promises greater understanding and prediction of the predatory impacts of invasive species. Other interspecific interactions, however, such as parasitism and higher-order predation, have the potential to modify predator–prey interactions and thus the predictive capability of the comparative functional response approach. We used a four-species community module (higher-order predator; focal native or invasive predators; parasites of focal predators; native prey) to compare the predatory functional responses of native Gammarus duebeni celticus and invasive Gammarus pulex amphipods towards three invertebrate prey species (Asellus aquaticus, Simulium spp., Baetis rhodani), thus, quantifying the context dependencies of parasitism and a higher-order fish predator on these functional responses. Our functional response experiments demonstrated that the invasive amphipod had a higher predatory impact (lower handling time) on two of three prey species, which reflects patterns of impact observed in the field. The community module also revealed that parasitism had context-dependent influences, for one prey species, with the potential to further reduce the predatory impact of the invasive amphipod or increase the predatory impact of the native amphipod in the presence of a higher-order fish predator. Partial consumption of prey was similar for both predators and occurred increasingly in the order A. aquaticus, Simulium spp. and B. rhodani. This was associated with increasing prey densities, but showed no context dependencies with parasitism or higher-order fish predator. This study supports the applicability of comparative functional responses as a tool to predict and assess invasive species impacts incorporating multiple context dependencies. PMID:25265905

  14. Community interactions modify the effects of pharmaceutical exposure: a microcosm study on responses to propranolol in Baltic Sea coastal organisms.

    PubMed

    Oskarsson, Hanna; Eriksson Wiklund, Ann-Kristin; Thorsén, Gunnar; Danielsson, Gabriela; Kumblad, Linda

    2014-01-01

    This study investigated the uptake and effects of a common human pharmaceutical, propranolol, on the structure and function of a coastal Baltic Sea model community consisting of macroalga (Ceramium tenuicorne), mussels (Mytilus edulis trossulus), amphipods (Gammarus spp.), water and sediment. The most sensitive species, the mussel, was affected to the same extent as in previous single species studies, while the effects on the amphipod and alga were smaller or even positive compared to experiments performed in less complex test systems. The observed cascade of beneficial effects was a result of inter-specific species interactions that buffered for more severe effects. The poor condition of the mussel led to a feeding shift from alga to mussel by the amphipods. The better food quality, due to the dietary shift, counteracted the effects of the exposure. Less amphipod grazing, together with increased levels of nutrients in the water was favourable for the alga, despite the negative effects of propranolol. This microcosm study showed effects on organisms on different organizational levels as well as interactions among the different components resulting in indirect exposure effects of both functional and structural nature. The combination of both direct and indirect effects would not have been detected using simpler single- or even two-species study designs. The observed structural changes would in the natural environment have a long-term influence on ecosystem function, especially in a low-biodiversity ecosystem like the Baltic Sea. PMID:24713620

  15. The life cycle of Huffmanela huffmani Moravec, 1987(Nematoda: Trichosomoididae), an endemic marine-relict parasite of Centrarchidae from a Central Texas spring.

    PubMed

    Worsham, McLean L D; Huffman, David G; Moravec, Frantisek; Gibson, J Randy

    2016-01-01

    The life cycle of the swim bladder nematode Huffmanela huffmani Moravec, 1987 (Trichinelloidea: Trichosomoididae), an endemic parasite of centrarchid fishes in the upper spring run of the San Marcos River in Hays County, Texas, USA, was experimentally completed. The amphipods Hyalella cf. azteca (Saussure), Hyalella sp. and Gammarus sp. were successfully infected with larvated eggs of Huffmanela huffmani. After ingestion of eggs of H. huffmani by experimental amphipods, the first-stage larvae hatch from their eggshells and penetrate through the digestive tract to the hemocoel of the amphipod. Within about 5 days in the hemocoel of the experimental amphipods at 22 °C, the larvae presumably attained the second larval stage and were infective for the experimental centrarchid definitive hosts, Lepomis spp. The minimum incubation period before adult nematodes began laying eggs in the swim bladders of the definitive hosts was found to be about 7.5 months at 22 °C. This is the first experimentally completed life cycle within the Huffmanelinae. PMID:27312028

  16. Community Interactions Modify the Effects of Pharmaceutical Exposure: A Microcosm Study on Responses to Propranolol in Baltic Sea Coastal Organisms

    PubMed Central

    Oskarsson, Hanna; Eriksson Wiklund, Ann-Kristin; Thorsén, Gunnar; Danielsson, Gabriela; Kumblad, Linda

    2014-01-01

    This study investigated the uptake and effects of a common human pharmaceutical, propranolol, on the structure and function of a coastal Baltic Sea model community consisting of macroalga (Ceramium tenuicorne), mussels (Mytilus edulis trossulus), amphipods (Gammarus spp.), water and sediment. The most sensitive species, the mussel, was affected to the same extent as in previous single species studies, while the effects on the amphipod and alga were smaller or even positive compared to experiments performed in less complex test systems. The observed cascade of beneficial effects was a result of inter-specific species interactions that buffered for more severe effects. The poor condition of the mussel led to a feeding shift from alga to mussel by the amphipods. The better food quality, due to the dietary shift, counteracted the effects of the exposure. Less amphipod grazing, together with increased levels of nutrients in the water was favourable for the alga, despite the negative effects of propranolol. This microcosm study showed effects on organisms on different organizational levels as well as interactions among the different components resulting in indirect exposure effects of both functional and structural nature. The combination of both direct and indirect effects would not have been detected using simpler single- or even two-species study designs. The observed structural changes would in the natural environment have a long-term influence on ecosystem function, especially in a low-biodiversity ecosystem like the Baltic Sea. PMID:24713620

  17. Environmental monitoring using malformed embryos of the amphipod Monoporeia affinis

    SciTech Connect

    Sundelin, B.; Eriksson, A.K.

    1995-12-31

    Reproduction variables of Monoporeia affinis, such as embryonic malformation were confirmed as the most sensitive variable, when soft bottom microcosms were exposed to metals such as cadmium and lead, arsenic, organic compounds such as 4,5,6 trichloroguaiacol, contaminated sediment from areas impacted by heavy metals and pulp mill effluents. The effects were demonstrated also in low concentrations that did not significantly affect the meiofauna community. The microcosm test-system with high ecological realism could offer a possibility to translate laboratory results to the natural environments. Field surveys outside different types of pulp mills and metal works on the coast of the Gulf of Bothnia have confirmed the laboratory results. Significantly higher levels of malformed embryos of Monoporeia affinis were demonstrated in the impacted areas in comparison with reference areas. The reproduction variables of Monoporeia affinis have been used in the national environmental monitoring program during two years and results indicated possibilities to distinguish between effects of xenobiotica and secondary eutrophication effects, such as unsaturated oxygen condition and occurrence of sulfides, which resulted in increased frequencies of dead eggs but not affected the frequencies of malformed eggs and embryos.

  18. Organochlorine pesticides and polychlorinated biphenyls in the Arctic Ocean food web.

    PubMed

    Hargrave, B T; Harding, G C; Vass, W P; Erickson, P E; Fowler, B R; Scott, V

    1992-01-01

    Polychlorinated biphenyls (PCBs), polychlorinated camphenes (PCCs) and isomers of DDT and DDE were the predominant organochlorine (OC) hydrocarbons measured in epontic particulate matter, zooplankton, pelagic and benthic amphipods and liver tissue from an abyssal fish collected in the Arctic Ocean. Chlordane, dieldrin and other cyclodienes and hexachlorocyclohexane (HCH) isomers were present at lower concentrations. Levels on a dry weight basis in plankton of various sizes less than 63 microns to 2 mm were similar to those in epontic particulate matter, but on a lipid weight basis, concentrations in smaller plankton were two to five times higher. Organochlorines in amphipods and liver from the glacial eelpout Lycodes frigidus exceeded levels in zooplankton by up to an order of magnitude. Large benthic lysianassid amphipods (Tmetonyx cicada, Anonyx nugax and Eurythenes gryllus) accumulated higher concentrations on a dry and lipid weight basis than small species (Onisimus spp. and Andaniexis spp.) or the under-ice gammaridean amphipod (Gammarus wilkitzkii). No significant differences in OC levels were measured in benthic amphipods collected at different times. However, concentrations in large zooplankton (greater than 500 microns) collected in August, dominated by adult copepods and ctenophores, contained concentrations of alpha-HCH, chlordane isomers and other cyclodienes that were two to four times higher than levels in May. Ratios of alpha-HCH: gamma-HCH (5 to 10) were similar to those in seawater collected simultaneously but there was no difference in ratios in various size categories of planktonic and benthic crustaceans indicating no selective accumulation or metabolic alteration of these isomers. Ratios of cis-chlordane:trans-chlordane concentrations were lower in all sizes of zooplankton (2 to 3) than in shelf amphipods (3 to 6) which corresponded to an increase in the ratio with depth. Higher ratios of DDT:DDE in plankton (2 to 6) than in amphipods (1 to 2

  19. Significance of Xenobiotic Metabolism for Bioaccumulation Kinetics of Organic Chemicals in Gammarus pulex

    PubMed Central

    2012-01-01

    Bioaccumulation and biotransformation are key toxicokinetic processes that modify toxicity of chemicals and sensitivity of organisms. Bioaccumulation kinetics vary greatly among organisms and chemicals; thus, we investigated the influence of biotransformation kinetics on bioaccumulation in a model aquatic invertebrate using fifteen 14C-labeled organic xenobiotics from diverse chemical classes and physicochemical properties (1,2,3-trichlorobenzene, imidacloprid, 4,6-dinitro-o-cresol, ethylacrylate, malathion, chlorpyrifos, aldicarb, carbofuran, carbaryl, 2,4-dichlorophenol, 2,4,5-trichlorophenol, pentachlorophenol, 4-nitrobenzyl-chloride, 2,4-dichloroaniline, and sea-nine (4,5-dichloro-2-octyl-3-isothiazolone)). We detected and identified metabolites using HPLC with UV and radio-detection as well as high resolution mass spectrometry (LTQ-Orbitrap). Kinetics of uptake, biotransformation, and elimination of parent compounds and metabolites were modeled with a first-order one-compartment model. Bioaccumulation factors were calculated for parent compounds and metabolite enrichment factors for metabolites. Out of 19 detected metabolites, we identified seven by standards or accurate mass measurements and two via pathway analysis and analogies to other compounds. 1,2,3-Trichlorobenzene, imidacloprid, and 4,6-dinitro-o-cresol were not biotransformed. Dietary uptake contributed little to overall uptake. Differentiation between parent and metabolites increased accuracy of bioaccumulation parameters compared to total 14C measurements. Biotransformation dominated toxicokinetics and strongly affected internal concentrations of parent compounds and metabolites. Many metabolites reached higher internal concentrations than their parents, characterized by large metabolite enrichment factors. PMID:22321051

  20. Hexachlorobenzene uptake by fathead minnows and macroinvertebrates in recirculating sediment/water systems

    SciTech Connect

    Schuytema, G.S.; Krawczyk, D.F.; Griffis, W.L.; Nebeker, A.V.; Robideaux, M.L.

    1990-01-01

    Fathead minnow (Pimephales promelas), the worm, Lumbriculus variegatus, and the amphipods Hyalella azteca and Gammarus lacustris were exposed to hexachlorobenzene (HCB) in water with and without a bed of HCB-spiked sediment. Water HCB concentrations were maintained by recirculation through HCB-packed columns. Recirculating HCB-bound particulates and possibly eroded HCB particulates were an added source of HCB in addition to the sediment bed. Significant bioaccumulation of HCB in animal tissues was observed in water-only and water-sediment exposures. The presence of the HCB-spiked sediment did not result in a significant increase in the uptake of HCB by the organisms, but there was a substantial increase in sediment HCB levels over time. Higher tissue HCB levels in aquaria without sediment suggest that the sediment was a more efficient sink for HCB than the organisms.

  1. Diets of Lesser Scaup during spring migration throughout the upper-Midwest are consistent with the spring condition hypothesis

    USGS Publications Warehouse

    Anteau, M.J.; Afton, A.D.

    2008-01-01

    The spring condition hypothesis (SCH) states that the current decline of the North American scaup population (Lesser [Aythya affinis] and Greater Scaup [A. marila] combined) is due to a decline in quality or availability of scaup foods on wintering, spring migration, or breeding areas that has caused a reduction in female body condition and subsequent reproductive success. Our previous research indicated that forage quality in diets of Lesser Scaup (hereafter scaup) at two sites in Northwestern Minnesota was lower in springs 2000-2001 than that reported for springs 1986-1988, consistent with the SCH. Accordingly, we further tested the SCH at a landscape scale, by comparing amounts of amphipods in diets (index of forage quality) of scaup (N = 263) collected in springs 2003-2005 from seven eco-physiographic regions in Iowa, Minnesota, and North Dakota in relation to data from Northwestern Minnesota during springs 2000-2001. We found that aggregate percentages of Gammarus lacustris and Hyalella azteca (amphipods) in scaup diets during springs 2000-2001 in Northwest Minnesota were similar to those in the Iowa Prairie Pothole, Minnesota Morainal, Minnesota Glaciated Plains, Red River Valley, and Northwestern Minnesota in springs 2003-2005; however, scaup consumed relatively higher aggregate percentages of Gammarus lacustris and Hyalella azteca in North Dakota Missouri Coteau and North Dakota Glaciated Plains. Females in Iowa were over three times less likely to have consumed food than those in North Dakota, despite previous research indicating similar foraging rates among these regions. Mean mass of scaup diet samples throughout the upper-Midwest were 77 mg (49%) and 87 mg (52%) lower than those of historical studies in Minnesota and Manitoba, respectively. We conclude that there has been a decrease in forage quality for scaup in Iowa and Minnesota and a decrease in the amount of forage consumed throughout the upper-Midwest, consistent with the SCH.

  2. Multidimensionality in host manipulation mimicked by serotonin injection.

    PubMed

    Perrot-Minnot, Marie-Jeanne; Sanchez-Thirion, Kevin; Cézilly, Frank

    2014-12-01

    Manipulative parasites often alter the phenotype of their hosts along multiple dimensions. 'Multidimensionality' in host manipulation could consist in the simultaneous alteration of several physiological pathways independently of one another, or proceed from the disruption of some key physiological parameter, followed by a cascade of effects. We compared multidimensionality in 'host manipulation' between two closely related amphipods, Gammarus fossarum and Gammarus pulex, naturally and experimentally infected with Pomphorhynchus laevis (Acanthocephala), respectively. To that end, we calculated in each host-parasite association the effect size of the difference between infected and uninfected individuals for six different traits (activity, phototaxis, geotaxis, attraction to conspecifics, refuge use and metabolic rate). The effects sizes were highly correlated between host-parasite associations, providing evidence for a relatively constant 'infection syndrome'. Using the same methodology, we compared the extent of phenotypic alterations induced by an experimental injection of serotonin (5-HT) in uninfected G. pulex to that induced by experimental or natural infection with P. laevis. We observed a significant correlation between effect sizes across the six traits, indicating that injection with 5-HT can faithfully mimic the 'infection syndrome'. This is, to our knowledge, the first experimental evidence that multidimensionality in host manipulation can proceed, at least partly, from the disruption of some major physiological mechanism. PMID:25339729

  3. Multidimensionality in host manipulation mimicked by serotonin injection

    PubMed Central

    Perrot-Minnot, Marie-Jeanne; Sanchez-Thirion, Kevin; Cézilly, Frank

    2014-01-01

    Manipulative parasites often alter the phenotype of their hosts along multiple dimensions. ‘Multidimensionality’ in host manipulation could consist in the simultaneous alteration of several physiological pathways independently of one another, or proceed from the disruption of some key physiological parameter, followed by a cascade of effects. We compared multidimensionality in ‘host manipulation’ between two closely related amphipods, Gammarus fossarum and Gammarus pulex, naturally and experimentally infected with Pomphorhynchus laevis (Acanthocephala), respectively. To that end, we calculated in each host–parasite association the effect size of the difference between infected and uninfected individuals for six different traits (activity, phototaxis, geotaxis, attraction to conspecifics, refuge use and metabolic rate). The effects sizes were highly correlated between host–parasite associations, providing evidence for a relatively constant ‘infection syndrome’. Using the same methodology, we compared the extent of phenotypic alterations induced by an experimental injection of serotonin (5-HT) in uninfected G. pulex to that induced by experimental or natural infection with P. laevis. We observed a significant correlation between effect sizes across the six traits, indicating that injection with 5-HT can faithfully mimic the ‘infection syndrome’. This is, to our knowledge, the first experimental evidence that multidimensionality in host manipulation can proceed, at least partly, from the disruption of some major physiological mechanism. PMID:25339729

  4. Lotic community responses in the Lees Ferry reach

    NASA Astrophysics Data System (ADS)

    McKinney, T.; Rogers, R. S.; Ayers, A. D.; Persons, W. R.

    Responses of periphyton, aquatic macrophytes, benthic macroinvertebrates, and rainbow trout to the 1996 controlled flood were investigated in the Lees Ferry tailwater reach below Glen Canyon Dam on the Colorado River. Lotic biota differed spatially and temporally in abundance and distribution following recession of flood waters, and there was no evidence that the flood benefitted trout or lower trophic levels. The flood was associated with short-term changes in lower trophic levels, but benthic vegetation and macrofauna with low resistance were resilient. Adverse impacts of the flood on lower trophic levels were greater and more prolonged in depositional areas than on cobble bar habitat, but recovery occurred in both habitat types 4-8 months after the flood. The flood likely resulted in some downstream displacement of smaller fish but had no effects on catch rate or condition indices of trout. Percentage of young-of-the-year trout 8 months after the event indicates that the flood did not prevent successful spawning. The flood had little direct influence on diets of trout, but relative gut volume increased in the week after the event, remained high in summer, and composition changed seasonally. Amphipods (Gammarus lacustris), chironomids, and snails were predominant food items, and Gammarus generally were eaten more often and comprised greater relative volume in the diet than other macroinvertebrate taxa.

  5. Arctic sea-ice ridges—Safe heavens for sea-ice fauna during periods of extreme ice melt?

    NASA Astrophysics Data System (ADS)

    Gradinger, Rolf; Bluhm, Bodil; Iken, Katrin

    2010-01-01

    The abundances and distribution of metazoan within-ice meiofauna (13 stations) and under-ice fauna (12 stations) were investigated in level sea ice and sea-ice ridges in the Chukchi/Beaufort Seas and Canada Basin in June/July 2005 using a combination of ice coring and SCUBA diving. Ice meiofauna abundance was estimated based on live counts in the bottom 30 cm of level sea ice based on triplicate ice core sampling at each location, and in individual ice chunks from ridges at four locations. Under-ice amphipods were counted in situ in replicate ( N=24-65 per station) 0.25 m 2 quadrats using SCUBA to a maximum water depth of 12 m. In level sea ice, the most abundant ice meiofauna groups were Turbellaria (46%), Nematoda (35%), and Harpacticoida (19%), with overall low abundances per station that ranged from 0.0 to 10.9 ind l -1 (median 0.8 ind l -1). In level ice, low ice algal pigment concentrations (<0.1-15.8 μg Chl a l -1), low brine salinities (1.8-21.7) and flushing from the melting sea ice likely explain the low ice meiofauna concentrations. Higher abundances of Turbellaria, Nematoda and Harpacticoida also were observed in pressure ridges (0-200 ind l -1, median 40 ind l -1), although values were highly variable and only medians of Turbellaria were significantly higher in ridge ice than in level ice. Median abundances of under-ice amphipods at all ice types (level ice, various ice ridge structures) ranged from 8 to 114 ind m -2 per station and mainly consisted of Apherusa glacialis (87%), Onisimus spp. (7%) and Gammarus wilkitzkii (6%). Highest amphipod abundances were observed in pressure ridges at depths >3 m where abundances were up to 42-fold higher compared with level ice. We propose that the summer ice melt impacted meiofauna and under-ice amphipod abundance and distribution through (a) flushing, and (b) enhanced salinity stress at thinner level sea ice (less than 3 m thickness). We further suggest that pressure ridges, which extend into deeper, high

  6. Genetic diversity in two introduced biofouling amphipods (Amphipods valida and Jassa marmorata) along the Pacific North American coast: investigation into molecular identification and cryptic diversity

    EPA Science Inventory

    We investigated patterns of genetic diversity among invasive populations of A. valida and J. marmorata from the Pacific North American coast to assess the accuracy of morphological identification and determine whether or not cryptic diversity and multiple introductions contribute...

  7. Endangered cave crustacean could be water quality indicator in Illinois Karst Region

    NASA Astrophysics Data System (ADS)

    Showstrack, Randy

    Some of the rolling, rural countryside of southwestern Illinois has become just a 20-minute commute from the sprawling city of St. Louis, Missouri, across the Mississippi River, now that newly built roads have opened up the landscape. But as more houses rise in rapidly developing bedroom communities, increasing levels of coliform bacteria—probably originating from septic systems and livestock—are being found in the groundwater. Trace amounts of pesticides, including atrazine, also are present.These contaminants, in large enough quantities, can pollute groundwater and cause public health problems. They also appear to be responsible for the decreased habitat and population of a little-known cave-dwelling crustacean, the Illinois Cave Amphipod (Gammarus acherondytes), a tailless shrimp that can grow up to 20 mm in length and that swims in underground streams in cave dark zones. Decreased dissolved oxygen content in the streams, resulting from land development activities that can cause faster surface runoff, also may affect the amphipod.

  8. Pronounced and prevalent intersexuality does not impede the 'Demon Shrimp' invasion.

    PubMed

    Green Etxabe, Amaia; Short, Stephen; Flood, Tim; Johns, Tim; Ford, Alex T

    2015-01-01

    Crustacean intersexuality is widespread and often linked to infection by sex-distorting parasites. However, unlike vertebrate intersexuality, its association with sexual dysfunction is unclear and remains a matter of debate. The 'Demon Shrimp,' Dikerogammarus haemobaphes, an amphipod that has invaded continental waterways, has recently become widespread in Britain. Intersexuality has been noted in D. haemobaphes but not investigated further. We hypothesise that a successful invasive population should not display a high prevalence of intersexuality if this condition represents a truly dysfunctional phenotype. In addition, experiments have indicated that particular parasite burdens in amphipods may facilitate invasions. The rapid and ongoing invasion of British waterways represents an opportunity to determine whether these hypotheses are consistent with field observations. This study investigates the parasites and sexual phenotypes of D. haemobaphes in British waterways, characterising parasite burdens using molecular screening, and makes comparisons with the threatened Gammarus pulex natives. We reveal that invasive and native populations have distinct parasitic profiles, suggesting the loss of G. pulex may have parasite-mediated eco-system impacts. Furthermore, the parasite burdens are consistent with those previously proposed to facilitate biological invasions. Our study also indicates that while no intersexuality occurs in the native G. pulex, approximately 50% of D. haemobaphes males present pronounced intersexuality associated with infection by the microsporidian Dictyocoela berillonum. This unambiguously successful invasive population presents, to our knowledge, the highest reported prevalence of male intersexuality. This is the clearest evidence to date that such intersexuality does not represent a form of debilitating sexual dysfunction that negatively impacts amphipod populations. PMID:25699206

  9. Pronounced and prevalent intersexuality does not impede the ‘Demon Shrimp’ invasion

    PubMed Central

    Green Etxabe, Amaia; Short, Stephen; Flood, Tim; Johns, Tim

    2015-01-01

    Crustacean intersexuality is widespread and often linked to infection by sex-distorting parasites. However, unlike vertebrate intersexuality, its association with sexual dysfunction is unclear and remains a matter of debate. The ‘Demon Shrimp,’ Dikerogammarus haemobaphes, an amphipod that has invaded continental waterways, has recently become widespread in Britain. Intersexuality has been noted in D. haemobaphes but not investigated further. We hypothesise that a successful invasive population should not display a high prevalence of intersexuality if this condition represents a truly dysfunctional phenotype. In addition, experiments have indicated that particular parasite burdens in amphipods may facilitate invasions. The rapid and ongoing invasion of British waterways represents an opportunity to determine whether these hypotheses are consistent with field observations. This study investigates the parasites and sexual phenotypes of D. haemobaphes in British waterways, characterising parasite burdens using molecular screening, and makes comparisons with the threatened Gammarus pulex natives. We reveal that invasive and native populations have distinct parasitic profiles, suggesting the loss of G. pulex may have parasite-mediated eco-system impacts. Furthermore, the parasite burdens are consistent with those previously proposed to facilitate biological invasions. Our study also indicates that while no intersexuality occurs in the native G. pulex, approximately 50% of D. haemobaphes males present pronounced intersexuality associated with infection by the microsporidian Dictyocoela berillonum. This unambiguously successful invasive population presents, to our knowledge, the highest reported prevalence of male intersexuality. This is the clearest evidence to date that such intersexuality does not represent a form of debilitating sexual dysfunction that negatively impacts amphipod populations. PMID:25699206

  10. The magnetic orientation of the Antarctic amphipod Gondogeneia antarctica is cancelled by very weak radiofrequency fields.

    PubMed

    Tomanova, K; Vacha, M

    2016-06-01

    Studies on weak man-made radiofrequency (RF) electromagnetic fields affecting animal magnetoreception aim for a better understanding of the reception mechanism and also point to a new phenomenon having possible consequences in ecology and environmental protection. RF impacts on magnetic compasses have recently been demonstrated in migratory birds and other vertebrates. We set out to investigate the effect of RF on the magnetic orientation of the Antarctic krill species Gondogeneia antarctica, a small marine crustacean widespread along the Antarctic littoral line. Here, we show that upon release, G. antarctica (held under laboratory conditions) escaped in the magnetically seaward direction along the magnetic sea-land axis (y-axis) of the home beach. However, the animals were disoriented after being exposed to RF. Orientation was lost not only in an RF field with a magnetic flux density of 20 nT, as expected according to the literature, but even under the 2 nT originally intended as a control. Our results extend recent findings of the extraordinary sensitivity of animal magnetoreception to weak RF fields in marine invertebrates. PMID:27026715

  11. USE OF THE AMPHIPOD CRUSTACEAN HYALELLA AZTECA IN FRESHWATER AND ESTUARINE SEDIMENT TOXICITY TESTS

    EPA Science Inventory

    Hyalella azteca (Saussure), which are currently used in toxicity tests with freshwater sediments, were tested to determine their suitability for tests with estuarine sediments. eproduction was good after 24 d at and below 12.5 g/L (ppt) salinity in water only. C50 values (50% red...

  12. INFLUENCES OF SEDIMENTARY ORGANIC MATTER QUALITY ON THE BIOACCUMULATION OF 4-NONYLPHENOL BY ESTUARINE AMPHIPODS

    EPA Science Inventory

    Nonylphenol (NP) is a moderately persistent, hydrophobic chemical (Log Kow 4.5) with endocrine disrupting and acute narcotic effects in aquatic biota. There is concern about the ultimate fate of NP in aquatic ecosystems and potential for bioaccumulation by benthic biota from the ...

  13. MINIATURIZED SEDIMENT PROCEDURES FOR ASESSING TOXICITY USING MARINE AND FRESHWATER AMPHIPODS AND EMBRYO/LARVAL FISH

    EPA Science Inventory

    Sediment toxicity tests are needed that can be conducted with less sediment volume and fewer organisms. Bench scale remediation techniques often produce less sediment than is required to perform the standardized sediment methods and the excess sediments that are generated present...

  14. Evaluation of Reduced Sediment Volume Procedures for Acute Toxicity Tests Using the Estuarine Amphipod Leptocheirus plumulosus

    EPA Science Inventory

    The volume of sediment required to perform a sediment toxicity bioassay is a major driver of the overall cost associated with that bioassay. Sediment volume affects bioassay cost due to sediment collection, transportation, storage, and disposal costs as well as labor costs assoc...

  15. Islands beneath islands: phylogeography of a groundwater amphipod crustacean in the Balearic archipelago

    PubMed Central

    2011-01-01

    Background Metacrangonyctidae (Amphipoda, Crustacea) is an enigmatic continental subterranean water family of marine origin (thalassoid). One of the species in the genus, Metacrangonyx longipes, is endemic to the Balearic islands of Mallorca and Menorca (W Mediterranean). It has been suggested that the origin and distribution of thalassoid crustaceans could be explained by one of two alternative hypotheses: (1) active colonization of inland freshwater aquifers by a marine ancestor, followed by an adaptative shift; or (2) passive colonization by stranding of ancestral marine populations in coastal aquifers during marine regressions. A comparison of phylogenies, phylogeographic patterns and age estimations of clades should discriminate in favour of one of these two proposals. Results Phylogenetic relationships within M. longipes based on three mitochondrial DNA (mtDNA) and one nuclear marker revealed five genetically divergent and geographically structured clades. Analyses of cytochrome oxidase subunit 1 (cox1) mtDNA data showed the occurrence of a high geographic population subdivision in both islands, with current gene flow occurring exclusively between sites located in close proximity. Molecular-clock estimations dated the origin of M. longipes previous to about 6 Ma, whereas major cladogenetic events within the species took place between 4.2 and 2.0 Ma. Conclusions M. longipes displayed a surprisingly old and highly fragmented population structure, with major episodes of cladogenesis within the species roughly correlating with some of the major marine transgression-regression episodes that affected the region during the last 6 Ma. Eustatic changes (vicariant events) -not active range expansion of marine littoral ancestors colonizing desalinated habitats-explain the phylogeographic pattern observed in M. longipes. PMID:21791038

  16. TESTING ACUTE TOXICITY OF CONTAMINATED SEDIMENT IN JINZHOU BAY WITH MARINE AMPHIPODS

    EPA Science Inventory

    Sediments in some areas of Jinzhou Bay are contaminated seriously by heavy metals and organic contaminants. To assess the biological effects of these compounds in the sediment, seven surface samples of sediment were collected at an interval of about 2km between sampling stations ...

  17. Evaluation of reduced sediment volume procedures for acute toxicity tests using the estuarine amphipod Leptocheirus plumulosus.

    PubMed

    Stanley, Jacob K; Kennedy, Alan J; Farrar, J Daniel; Mount, David R; Steevens, Jeffery A

    2010-12-01

    The volume of sediment required to perform a sediment toxicity bioassay is a major driver of the overall cost associated with that bioassay. Sediment volume affects bioassay cost because of sediment collection, transportation, storage, and disposal costs as well as labor costs associated with organism recovery at the conclusion of the exposure. The objective of the current study was to evaluate reduced sediment volume versions of the standard U.S. Environmental Protection Agency (U.S. EPA) 10-d acute Leptocheirus plumulosus method that uses a beaker size of 1,000 ml and 20 organisms. The test design used evaluated the effects of beaker size (250 and 100 ml) and associated sediment volume (75 and 30 ml, respectively) as well as organism loading density (10 and 20 organisms) on test endpoint responsiveness relative to the standard 10-d test method. These comparisons were completed with three different types of contaminated sediments: a field-collected polycyclic aromatic hydrocarbon (PAH)-contaminated sediment, a lead-spiked control sediment, and a control sediment spiked with mineral oil. Assessment criteria included test endpoint sensitivity, endpoint consistency, statistical power, water quality, and logistical assessments. Results indicate that the current U.S. EPA method is preferable to the reduced sediment volume methods we assessed, but that a 250-ml beaker/10 organism experimental design is of comparable utility and may be advantageous when reduced sediment volumes are desirable because of high contaminant (spiking studies) or sediment disposal costs. In addition, the results of the current study provide toxicity reference values for PAHs, lead, and an oil surrogate for petroleum hydrocarbons. PMID:20890914

  18. BENTHIC MACROALGAE, DISSOLVED SULFIDES, AND AMPHIPODS IN SURFICIAL SEDIMENTS OF YAQUINA BAY ESTUARY, OREGON, USA

    EPA Science Inventory

    Surveys of benthic green macroalgae at two sites in Yaquina Bay Estuary, Oregon, in 1999 showed that percent cover and biomass values in June were much higher at one site, Idaho Point, than at the other site, Coquille Point. The frequency of detectable hydrogen sulfide odor late...

  19. Status of the amphipod Diporeia ssp. in coastal waters of the Laurentian Great Lakes

    EPA Science Inventory

    Diporeia has historically been the dominant benthic macroinvertebrate in deeper waters of the Laurentian Great Lakes, and its abundance has been proposed as an indicator of ecological condition. In 2010, the USEPA incorporated the Great Lakes into the National Coastal Condition A...

  20. ACUTE TOXICITY OF SEDIMENT FROM EAGLE HARBOR, WASHINGTON, TO THE INFAUNAL AMPHIPOD RHEPOXYNIUS ABRONIUS

    EPA Science Inventory

    Creosote-contaminated sediment from one station (EH08) in Eagle Harbor, Washington, is among the most toxic sediment yet tested from U.S. estuaries and coastal waters. he total concentration of 13 polynuclear aromatic hydrocarbons in EH08 sediment was 6,461 mg/kg (dry wt.). he cn...

  1. Development of Reduced Sediment Volume Test Procedures for the Estuarine Amphipod Leptocheirus plumulosus

    EPA Science Inventory

    The sediment volume requirements of toxicity and bioaccumulation bioassays affect the cost of the assessment related to field collection, transportation, storage, disposal, and labor associated with organism recovery at bioassay termination. Our objective was to assess four redu...

  2. Kuril-Kamchatka deep sea revisited - insights into the amphipod abyssal fauna

    NASA Astrophysics Data System (ADS)

    Jażdżewska, Anna

    2015-01-01

    During the KuramBIO expedition to the Kuril-Kamchatka Trench and abyssal plain, benthic samples from the depths from 4987 to 5422 m were collected using a camera-epibenthic sledge. In this collection more than 1200 individuals of Amphipoda were found. They were assigned to 60 taxa (including 47 morphospecies) and 21 families. Until now 28 species being new to science have been found: six in the superfamily Eusiroidea and in the Oedicerotidae and Synopiidae families, four in the Phoxocephalidae, three in the Pardaliscidae, two in the Stenothoidae and one in the Pachynidae. The Synopiidae, Stenothoidae and Pachynidae were recorded for the first time in North-West Pacific area. The dominant and most speciose families were Oedicerotidae, Phoxocephalidae, Synopiidae, Eusiridae s.l. and Lysianassidae. The cluster analysis clearly separated the shallowest sample from the others, which were divided further into two groups. The shallowest sample was characterized by the highest number of species and number of individuals.

  3. To bite, or not to bite? A quantitative comparison of foraging strategies among three brackish crustaceans feeding on leaf litters

    NASA Astrophysics Data System (ADS)

    Mancinelli, Giorgio

    2012-09-01

    A computerized image analysis technique was implemented to evaluate the damage done to leaf litters by macrophagous crustaceans characterized by different feeding strategies. In addition, a foraging strategy index (FSI) was tested to provide a quantitative estimation of both inter- and intra-specific, density-dependent changes in feeding strategies. Laboratory trials were run with the isopods Idotea baltica and Lekanesphaera hookeri and the amphipod Gammarus aequicauda. The effect of their feeding activities was tested on decaying leaves of Cymodocea nodosa and Phragmites australis. In addition, tests were run using three different abundances of each species to assess the occurrence of density-dependent shifts in feeding strategies. Independently from the leaf litter type, opposite foraging strategies characterized the isopods. Idotea baltica shredded the leaf blade heavily, whereas L. hookeri scraped the leaf surface removing the epidermis. Qualitative observations corresponded to consistent variations in FSI values, with Idotea showing the lowest and Lekanesphaera the highest FSI values. Leaves consumed by G. aequicauda, conversely, were characterized by both shredding and scraping damages, corresponding to intermediate FSI values compared to those measured for the isopods. Furthermore, negligible density-dependent changes in FSI values occurred for both isopods; Gammarus, in contrast, showed a significant shift in trophic strategies, with FSI values close to that observed for Lekanesphaera at high densities and to Idotea at low densities of conspecifics, respectively. The methodology and the FSI index herein presented provided an effective, quantitative assessment of species-specific differences in the feeding strategy of three ubiquitous components of Mediterranean detritivorous epifauna, for which only qualitative, phenomenological descriptions have been to date provided.

  4. Intraguild predation may reinforce a species-environment gradient

    NASA Astrophysics Data System (ADS)

    MacNeil, Calum; Dick, Jaimie T. A.

    2012-05-01

    Species-environment gradients are ubiquitous in nature, with studies often partially explaining the replacement of species along such gradients by autecological factors such as differential physiological tolerances. However, lacking direct evidence, the majority of studies only infer some form of inter-specific interaction, often competition, as reinforcing these gradients. There is usually the further implication that environmental factors mediate asymmetries in the interaction. Recognising the lack of explicit experimental considerations of how key inter-specific interactions are modified by the environment, we chose a study system where we were able to bring the species in question into the laboratory and conduct experiments to test hypotheses about gradient-induced asymmetries in an inter-specific interaction. To this end, we tested the hypothesis that a species-salinity gradient may be reinforced by changes in the asymmetry of intraguild predation between two species of amphipod crustaceans with wide salinity tolerances. River and estuary surveys showed that Gammarus duebeni and Gammarus zaddachi have overlapping distributions, with both surviving and reproducing in salinities ranging from freshwater to fully marine. However, the former species is relatively more abundant in low salinities and the latter in higher salinities. In the laboratory, survival of both species was high in all salinities and cannibalism occurred at low frequencies. However, intraguild predation by males on moulted females was asymmetric in favour of G. duebeni at low salinities, this asymmetry completely reversing to favour G. zaddachi at higher salinities. Thus, we provide evidence that this species-environment gradient occurs due to overlapping physiological tolerances and salinity-driven shifts in the asymmetry of a key inter-specific interaction, intraguild predation.

  5. Combined effects of drought and the fungicide tebuconazole on aquatic leaf litter decomposition.

    PubMed

    Pesce, Stéphane; Zoghlami, Olfa; Margoum, Christelle; Artigas, Joan; Chaumot, Arnaud; Foulquier, Arnaud

    2016-04-01

    Loss of biodiversity and altered ecosystem functioning are driven by the cumulative effects of multiple natural and anthropogenic stressors affecting both quantity and quality of water resources. Here we performed a 40-day laboratory microcosm experiment to assess the individual and combined effects of drought and the model fungicide tebuconazole (TBZ) on leaf litter decomposition (LLD), a fundamental biogeochemical process in freshwater ecosystems. Starting out from a worst-case scenario perspective, leaf-associated microbial communities were exposed to severe drought conditions (four 5-day drought periods alternated with 4-day immersion periods) and/or a chronic exposure to TBZ (nominal concentration of 20μgL(-1)). We assessed the direct effects of drought and fungicide on the structure (biomass, diversity) and activity (extracellular enzymatic potential) of fungal and bacterial assemblages colonizing leaves. We also investigated indirect effects on the feeding rates of the amphipod Gammarus fossarum on leaves previously exposed to drought and/or TBZ contamination. Results indicate a stronger effect of drought stress than fungicide contamination under the experimental conditions applied. Indeed, the drought stress strongly impacted microbial community structure and activities, inhibiting the LLD process and leading to cascading effects on macroinvertebrate feeding. However, despite the lack of significant effect of TBZ applied alone, the effects of drought on microbial functions (i.e., decrease in LLD and in enzymatic activities) and on Gammarus feeding rates were more pronounced when drought and TBZ stresses were applied together. In a perspective of ecological risk assessment and ecosystem management for sustainability, these findings stress the need for deeper insight into how multiple stressors can affect the functioning of aquatic ecosystems and associated services. PMID:26859779

  6. The Influence of Allochthonous Leaf Detritus on the Occurrence of Crustacean Detritivores in the Soft-bottom Macrobenthos of the Po River Delta Area (northwestern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Mancinelli, G.; Rossi, L.

    2002-05-01

    Core samples were examined quarterly at two coastal sites (S1 and S2) and at an offshore station (S3) located in the Po River delta area (northwestern Adriatic Sea). Analyses focused on (i) occurrence of coarse detritus of allochthonous origin in the sedimentary matrix and (ii) the relative influence of macrodetritus enrichment and other environmental factors on the vagile macrofauna. Plant debris occurred in site S1 sediments only in summer and autumn; in contrast, fragments of the phanerogams Cymodocea nodosa and Zostera spp. were found in site S2 sediment throughout the sampling period. Sediments from the offshore site S3 were characterized by negligible plant material, even though in summer and autumn samples debris of continental origin was observed. Even though leaf detritus occurrence at site S2 was ∼5-fold higher compared to the other coastal site S1, it did not influence the total organic matter and its distribution among grain-size classes. Conversely, the specific organic content of dimensional fractions provided an effective assessment of detritus enrichment processes occurring at the two coastal sites. A group of brackish-originated crustaceans (i.e. the amphipods Gammarus insensibilis and G. aequicauda and the isopod Idotea baltica) was the main determinant of among-site multivariate differences in the vagile macrofauna; depositivorous ophiuroids accounted for the residual differences observed during the study period. The analysis of taxa abundance and individual body size indicated that in both site S1 and S3 macrodetritus advection to the benthic system corresponded with passive dispersal of brackish crustaceans, that provided a negligible contribution to the macrobenthic production. In contrast, in site S2 allochthonous inputs from marginal environments could have represented the key factor for the persistence of an authochthonous population of Gammarus insensibilis. The amphipod provided a considerable (19·4%) contribution to the total

  7. Improving sediment-quality guidelines for nickel: development and application of predictive bioavailability models to assess chronic toxicity of nickel in freshwater sediments.

    PubMed

    Vangheluwe, Marnix L U; Verdonck, Frederik A M; Besser, John M; Brumbaugh, William G; Ingersoll, Christopher G; Schlekat, Christan E; Garman, Emily Rogevich

    2013-11-01

    Within the framework of European Union chemical legislations an extensive data set on the chronic toxicity of sediment nickel has been generated. In the initial phase of testing, tests were conducted with 8 taxa of benthic invertebrates in 2 nickel-spiked sediments, including 1 reasonable worst-case sediment with low concentrations of acid-volatile sulfide (AVS) and total organic carbon. The following species were tested: amphipods (Hyalella azteca, Gammarus pseudolimnaeus), mayflies (Hexagenia sp.), oligochaetes (Tubifex tubifex, Lumbriculus variegatus), mussels (Lampsilis siliquoidea), and midges (Chironomus dilutus, Chironomus riparius). In the second phase, tests were conducted with the most sensitive species in 6 additional spiked sediments, thus generating chronic toxicity data for a total of 8 nickel-spiked sediments. A species sensitivity distribution was elaborated based on 10% effective concentrations yielding a threshold value of 94 mg Ni/kg dry weight under reasonable worst-case conditions. Data from all sediments were used to model predictive bioavailability relationships between chronic toxicity thresholds (20% effective concentrations) and AVS and Fe, and these models were used to derive site-specific sediment-quality criteria. Normalization of toxicity values reduced the intersediment variability in toxicity values significantly for the amphipod species Hyalella azteca and G. pseudolimnaeus, but these relationships were less clearly defined for the mayfly Hexagenia sp. Application of the models to prevailing local conditions resulted in threshold values ranging from 126 mg to 281 mg Ni/kg dry weight, based on the AVS model, and 143 mg to 265 mg Ni/kg dry weight, based on the Fe model. PMID:23983116

  8. The Role of Seagrass Traits in Mediating Zostera noltei Vulnerability to Mesograzers.

    PubMed

    Martínez-Crego, Begoña; Arteaga, Pedro; Tomas, Fiona; Santos, Rui

    2016-01-01

    Understanding how intra-specific differences in plant traits mediate vulnerability to herbivores of relevant habitat-forming plants is vital to attain a better knowledge on the drivers of the structure and functioning of ecosystems. Such studies, however, are rare in seagrass-mesograzer systems despite the increasingly recognized relevance of mesograzers as seagrass consumers. We investigated the role and potential trade-offs of multiple leaf traits in mediating the vulnerability of the seagrass Zostera noltei to different mesograzer species, the amphipod Gammarus insensibilis and the isopod Idotea chelipes. We worked with plants from two different meadows for which contrasting chemical and structural traits were expected based on previous information. We found that plants with high vulnerability to mesograzers (i.e. those preferred and subjected to higher rates of leaf area loss) had not only higher nitrogen content and lower C:N, fibre, and phenolics, but also tender and thinner leaves. No trade-offs between chemical and structural traits of the seagrass were detected, as they were positively correlated. When leaf physical structure was removed using agar-reconstituted food, amphipod preference towards high-susceptibility plants disappeared; thus indicating that structural rather than chemical traits mediated the feeding preference. Removal of plant structure reduced the size of isopod preference to less than half, indicating a stronger contribution of structural traits (> 50%) but combined with chemical/nutritional traits in mediating the preference. We then hypothesized that the high environmental nutrient levels recorded in the meadow exhibiting high susceptibility modulate the differences observed between meadows in seagrass traits. To test this hypothesis, we exposed low-vulnerability shoots to eutrophic nutrient levels in a 6-week enrichment experiment. Nutrient enrichment increased Z. noltei nitrogen content and lowered C:N, fibre, and phenolics, but had

  9. The Role of Seagrass Traits in Mediating Zostera noltei Vulnerability to Mesograzers

    PubMed Central

    Martínez-Crego, Begoña; Arteaga, Pedro; Tomas, Fiona; Santos, Rui

    2016-01-01

    Understanding how intra-specific differences in plant traits mediate vulnerability to herbivores of relevant habitat-forming plants is vital to attain a better knowledge on the drivers of the structure and functioning of ecosystems. Such studies, however, are rare in seagrass-mesograzer systems despite the increasingly recognized relevance of mesograzers as seagrass consumers. We investigated the role and potential trade-offs of multiple leaf traits in mediating the vulnerability of the seagrass Zostera noltei to different mesograzer species, the amphipod Gammarus insensibilis and the isopod Idotea chelipes. We worked with plants from two different meadows for which contrasting chemical and structural traits were expected based on previous information. We found that plants with high vulnerability to mesograzers (i.e. those preferred and subjected to higher rates of leaf area loss) had not only higher nitrogen content and lower C:N, fibre, and phenolics, but also tender and thinner leaves. No trade-offs between chemical and structural traits of the seagrass were detected, as they were positively correlated. When leaf physical structure was removed using agar-reconstituted food, amphipod preference towards high-susceptibility plants disappeared; thus indicating that structural rather than chemical traits mediated the feeding preference. Removal of plant structure reduced the size of isopod preference to less than half, indicating a stronger contribution of structural traits (> 50%) but combined with chemical/nutritional traits in mediating the preference. We then hypothesized that the high environmental nutrient levels recorded in the meadow exhibiting high susceptibility modulate the differences observed between meadows in seagrass traits. To test this hypothesis, we exposed low-vulnerability shoots to eutrophic nutrient levels in a 6-week enrichment experiment. Nutrient enrichment increased Z. noltei nitrogen content and lowered C:N, fibre, and phenolics, but had

  10. Improving sediment-quality guidelines for nickel: development and application of predictive bioavailability models to assess chronic toxicity of nickel in freshwater sediments

    USGS Publications Warehouse

    Vangheluwe, Marnix L. U.; Verdonck, Frederik A. M.; Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.; Schlekat, Christan E.; Rogevich Garman, Emily

    2013-01-01

    Within the framework of European Union chemical legislations an extensive data set on the chronic toxicity of sediment nickel has been generated. In the initial phase of testing, tests were conducted with 8 taxa of benthic invertebrates in 2 nickel-spiked sediments, including 1 reasonable worst-case sediment with low concentrations of acid-volatile sulfide (AVS) and total organic carbon. The following species were tested: amphipods (Hyalella azteca, Gammarus pseudolimnaeus), mayflies (Hexagenia sp.), oligochaetes (Tubifex tubifex, Lumbriculus variegatus), mussels (Lampsilis siliquoidea), and midges (Chironomus dilutus, Chironomus riparius). In the second phase, tests were conducted with the most sensitive species in 6 additional spiked sediments, thus generating chronic toxicity data for a total of 8 nickel-spiked sediments. A species sensitivity distribution was elaborated based on 10% effective concentrations yielding a threshold value of 94 mg Ni/kg dry weight under reasonable worst-case conditions. Data from all sediments were used to model predictive bioavailability relationships between chronic toxicity thresholds (20% effective concentrations) and AVS and Fe, and these models were used to derive site-specific sediment-quality criteria. Normalization of toxicity values reduced the intersediment variability in toxicity values significantly for the amphipod species Hyalella azteca and G. pseudolimnaeus, but these relationships were less clearly defined for the mayfly Hexagenia sp. Application of the models to prevailing local conditions resulted in threshold values ranging from 126 mg to 281 mg Ni/kg dry weight, based on the AVS model, and 143 mg to 265 mg Ni/kg dry weight, based on the Fe model

  11. A new hedrurid species (Nematoda) from galaxiid fishes in Patagonia (Argentina) and infection of amphipods as intermediate host.

    PubMed

    Brugni, Norma L; Viozzi, Gustavo P

    2010-02-01

    During a parasite survey of galaxiid fishes (Galaxiidae) from Patagonian Andean lakes, a new species of nematode, Hedruris suttonae n. sp. was collected from the stomach of the native Galaxias maculatus (Jenyns) and G. platei (Steindachner). Specimens were examined by light and scanning electron microscopy, especially head morphology, female caudal prehensile structure, and distribution of spines. The new species is distinguished by body and tail size, morphology and size of spicules, the arrangement of caudal papillae in the male, the female caudal hook, and size of eggs. Hyalella patagonica (Ortmann), a Neotropical species of Amphipoda, is reported as its natural intermediate host. Data regarding prevalence and mean intensity in the intermediate and definitive hosts are included. The diet and habitat of the hosts, the percentage of gravid females, the high values of prevalence, and mean intensity in galaxiid fishes, as well as the wide distribution of H. suttonae , collectively indicate that, in these oligotrophic Andean lakes, G. maculatus and G. platei are true definitive hosts of this nematode. PMID:19737026

  12. Parhyale darvishi, a new widely distributed amphipod species, in the Persian Gulf and the Gulf of Oman (Crustacea, Amphipoda, Hyalidae).

    PubMed

    Momtazi, Farzaneh; Maghsoudlou, Abdolvahab

    2016-01-01

    Parhyale darvishi sp. nov., is described. The new species is characterized by a naked posterior margin on the propodus of pereopods 5-7, a special arrangement of robust setae on the first male gnathopod and a lack of dense fine setae on the second antennae. Parhyale darvishi sp. nov. is distributed from the western coasts of the Persian Gulf to the eastern coasts of Gulf of Oman. PMID:27395677

  13. SPATIAL VARIATION IN DENSITY, MEAN SIZE, AND PHYSIOLOGICAL CONDITION OF THE HOLARCTIC AMPHIPOD DIPOREIA SPP. IN LAKE MICHIGAN

    EPA Science Inventory

    We examined spatial patterns in population characteristics and physiological condition in Lake Michigan by collecting samples at up to 85 sites in late summer 1994 and 1995. Variables were examined relative to water depth and three lake regions: south, central and north. Most maj...

  14. PURIFICATION AND CHARACTERIZATION OF THE COMMON YOLK PROTEIN, VITELLIN, FROM THE ESTUARINE AMPHIPOD LEPTOCHEIRUS PLUMULOSUS. (R827397)

    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...

  15. Examining impacts of current-use pesticides in Southern Ontario using in situ exposures of the amphipod Hyalella azteca.

    PubMed

    Bartlett, Adrienne J; Struger, John; Grapentine, Lee C; Palace, Vince P

    2016-05-01

    In situ exposures with Hyalella azteca were used to assess impacts of current-use pesticides in Southern Ontario, Canada. Exposures were conducted over 2 growing seasons within areas of high pesticide use: 1 site on Prudhomme Creek and 3 sites on Twenty Mile Creek. Three sites on Spencer Creek, an area of low pesticide use, were added in the second season. Surface water samples were collected every 2 wk to 3 wk and analyzed for a suite of pesticides. Hyalella were exposed in situ for 1 wk every 4 wk to 6 wk, and survival and acetylcholinesterase (AChE) activity were measured. Pesticides in surface waters reflected seasonal use patterns: lower concentrations in spring and fall and higher concentrations during summer months. Organophosphate insecticides (chlorpyrifos, azinphos methyl, diazinon) and acid herbicides (2,4-dichlorophenoxyacetic acid [2,4-D], mecoprop) were routinely detected in Prudhomme Creek, whereas neutral herbicides (atrazine, metolachlor) dominated the pesticide signature of Twenty Mile Creek. Spencer Creek contained fewer pesticides, which were measured at lower concentrations. In situ effects also followed seasonal patterns: higher survival and AChE activity in spring and fall, and lower survival and AChE activity during summer months. The highest toxicity was observed at Prudhomme Creek and was primarily associated with organophosphates. The present study demonstrated that current-use pesticides in Southern Ontario were linked to in situ effects and identified sites of concern requiring further investigation. Environ Toxicol Chem 2016;35:1224-1238. © 2015 Crown in the Right of Canada. PMID:26436714

  16. A new species of Leucothoid Amphipod, Anamixis bananarama, sp. n., from Shallow Coral Reefs in French Polynesia (Crustacea, Amphipoda, Leucothoidae)

    PubMed Central

    James Darwin, Thomas; Krapp-Schickel, Traudl

    2011-01-01

    Abstract Both leucomorph and anamorph developmental stages of Anamixis bananarama sp. n., are illustrated and described from shallow back reef environments of Moorea, French Polynesia. Distinguished by vestigial first gnathopods that persist in post-transformational adult males, this is the second species in the genus to exhibit this unusual character. In other features such as coxae and second gnathopods Anamixis bananarama sp. n. resembles other Pacific Plate endemics of Anamixis known from the region. Specific host association is not documented but suspected to be small calcareous asconoid sponges associated with coral rubble. PMID:21594109

  17. Community structure and diversity of scavenging amphipods from bathyal to hadal depths in three South Pacific Trenches

    NASA Astrophysics Data System (ADS)

    Lacey, Nichola C.; Rowden, Ashley A.; Clark, Malcolm R.; Kilgallen, Niamh M.; Linley, Thomas; Mayor, Dan J.; Jamieson, Alan J.

    2016-05-01

    There are few biological datasets that span large bathymetric ranges with sufficient resolution to identify trends across the abyssal and hadal transition zone, particularly over multiple trenches. Here, scavenging Amphipoda were collected from three trenches in the South Pacific Ocean at bathyal to hadal depths. Diversity and community structure were examined from stations within the Kermadec Trench (1490-9908 m) and New Hebrides Trench (2000-6948 m) and additional data were included from the South Fiji Basin (4000 m) and Peru-Chile Trench (4602-8074 m). The hadal community structure of the Kermadec and New Hebrides trenches were distinct from the surrounding abyssal and bathyal depths and correlated to hydrostatic pressure and POC flux. Low POC flux in the New Hebrides Trench and South Fiji Basin best explained the dissimilarity in abyssal community structure from those of the disparate Kermadec and Peru-Chile trenches. POC flux also best explained patterns in hadal community structure with the Kermadec and New Hebrides Trench communities showing greater similarity to each other than to the eutrophic Peru-Chile Trench. Hydrostatic pressure was the strongest driver of intra-trench assemblage composition in all trench environments. A unimodal pattern of species diversity, peaking between 4000 and 5000 m, was best explained by hydrostatic pressure and temperature.

  18. [Lipids in the amphipod Talorchestia margaritae (Amphipoda: Talitridae) and its relationship with the ecology of the species].

    PubMed

    López, Sandra; Díaz, Yusbelly; Noris, Karem; Cabrera, Aivle

    2010-09-01

    T. margaritae, an endemic species inhabiting Venezuelan coasts, plays an important ecological role in plant and animal decomposition. To understand this issue in some animal groups, especially small ones, lipid composition analysis has been an interesting tool to describe their trophic relationships and food preferences. In order to assess this and visualize the components of their diet, we determined the lipid composition differences between males and females and among age classes in this species. Two sandy beaches were selected: Mangle Quemao and Las Mercedes de Paparo, from which sand samples of known volume were collected at the supralittoral area in 2007. Organisms were separated by age and sex classes, and their size, weight, density, biomass, total lipids (TL), lipid classes and fatty acid markers present in their tissues were determined. The sizes were similar for all age classes between the two locations, while the weights were higher for Mangle Quemao. The TL and lipid classes showed similar proportions between sexes, age classes and locations (TL: 3-5%; Phospholipids: 20-30%; Glycolipids: <1%; sterols: 4%). On the other hand, Triglycerides (TAG) were higher in Mangle Quemao, which may be related to the difference between the weights of two locations. The most abundant fatty acid biomarkers in the two studied sites were 16:0 and 18:1(n-9); this last one is characteristic of a carnivorous diet. The other nine markers were identified with changes in their distribution in organisms at Mangle Quemao and between males and females of both populations. Based on observed fatty acids markers we can assume T. margaritae as a generalist carnivore. Those populations were influenced by available food; inducing differences in weight, TAG proportion and markers diversity. PMID:20737842

  19. CRITICAL BODY RESIDUES FOR FRESHWATER AND SALTWATER AMPHIPODS EXPOSED TO SEDIMENT CONTAINING A MIXTURE OF HIGH KOW PAHS

    EPA Science Inventory

    Sediments were spiked with a mixture of 13 high log Kow (5.4-6.8) PAH compounds to determine critical body residues (CBR) in Hyalella azteca and Leptocheirus plumulosus. Hyalella were exposed for 28 d in a intermittent flow test and for 10 d in a static test to compare PAH uptake...

  20. Redescription of two subterranean amphipods Niphargusmolnari Méhely, 1927 and Niphargusgebhardti Schellenberg, 1934 (Amphipoda, Niphargidae) and their phylogenetic position.

    PubMed

    Angyal, Dorottya; Balázs, Gergely; Zakšek, Valerija; Krízsik, Virág; Fišer, Cene

    2015-01-01

    A detailed redescription of two endemic, cave-dwelling niphargid species of the Hungarian Mecsek Mts., Niphargusmolnari Méhely, 1927 and Niphargusgebhardti Schellenberg, 1934 is given based on newly collected material. Morphology was studied under light microscopy and with scanning electon microscopy. Morphological descriptions are complemented with mitochondrial cytochrome c oxidase subunit I (COI) sequences as barcodes for both species and with notes on their ecology. Using three independent molecular markers we showed that Niphargusgebhardti belongs to the clade distributed between Central and Eastern Europe, whereas phylogenetic relationship of Niphargusmolnari to the rest of Niphargus species is not clear. The two species from the Mecsek Mts. are phylogenetically not closely related. Both species need to be treated as vulnerable according to IUCN Red List of Threatened Species. PMID:26175603

  1. Effect of submersed aquatic macrophytes on resource partitioning in yearling rock bass (Ambloplites rupestris) and pumpkinseeds (Lepomis gibbosus) in Lake St. Clair

    USGS Publications Warehouse

    French, John R. P., III

    1988-01-01

    Yearling rock bass (Ambloplites rupestris), pumpkinseeds (Lepomis gibbosus), macroinvertebrates, and submersed aquatic plants were sampled at 2- or 3-week intervals from June to October 1979 in a shallow, heavily vegetated embayment in Lake St. Clair to determine whether seasonal changes in plant canopy and plant taxonomic composition affected resource partitioning in these two fish species. In both species, numbers of prey and gut volumes increased with increasing plant canopy until the plant canopy reached a seasonal maximum in mid-summer. Rock bass consumed fewer, larger prey than pumpkinseeds while large Caenidae-Trichoptera-Coenagrionidae, the prey group most preferred by rock bass, was available. Pumpkinseeds ate smaller amphipods, gastropods, and chironomid-lepidopterans that were more abundant numerically than Caenidae-Trichoptera-Coenagrionidae. After mid-summer, the plant canopy declined slowly to one-half of the maximum value, but built-up densities ofHyalella azteca, gastropods, and chironomid-lepidopterans kept availability of prey high throughout late summer. Rock bass shifted to Gammarus, gastropods, and chironomid-lepidopterans as large Caenidae-Trichoptera-Coenagrionidae became scarce. Pumpkinseeds ate more prey in the late season and displayed no prey preference. Their gut volumes peaked in September. Apparently, increasing combined canopy of bushy plants and Heteranthera dubia hindered the foraging of rock bass more than that of pumpkinseeds and caused resource partitioning in the two species.

  2. Altered host behaviour and brain serotonergic activity caused by acanthocephalans: evidence for specificity

    PubMed Central

    Tain, Luke; Perrot-Minnot, Marie-Jeanne; Cézilly, Frank

    2006-01-01

    Manipulative parasites can alter the phenotype of intermediate hosts in various ways. However, it is unclear whether such changes are just by-products of infection or adaptive and enhance transmission to the final host. Here, we show that the alteration of serotonergic activity is functionally linked to the alteration of specific behaviour in the amphipod Gammarus pulex infected with acanthocephalan parasites. Pomphorhynchus laevis and, to a lesser extent, Pomphorhynchus tereticollis altered phototactism, but not geotactism, in G. pulex, whereas the reverse was true for Polymorphus minutus. Serotonin (5-hydroxytryptamine, 5-HT) injected to uninfected G. pulex mimicked the altered phototactism, but had no effect on geotactism. Photophilic G. pulex infected with P. laevis or P. tereticollis showed a 40% increase in brain 5-HT immunoreactivity compared to photophobic, uninfected individuals. In contrast, brain 5-HT immunoreactivity did not differ between P. minutus-infected and uninfected G. pulex. Finally, brain 5-HT immunoreactivity differed significantly among P. tereticollis-infected individuals in accordance with their degree of manipulation. Our results demonstrate that altered 5-HT activity is not the mere consequence of infection by acanthocephalans but is specifically linked to the disruption of host photophobic behaviour, whereas the alteration of other behaviours such as geotactism may rely on distinct physiological routes. PMID:17015346

  3. Field and laboratory investigations on the effects of road salt (NaCl) on stream macroinvertebrate communities.

    PubMed

    Blasius, B J; Merritt, R W

    2002-01-01

    Field and laboratory experiments were conducted to examine the effects of road salt (NaCI) on stream macroinvertebrates. Field studies investigated leaf litter processing rates and functional feeding group composition at locations upstream and downstream from point source salt inputs in two Michigan, USA streams. Laboratory studies determined the effects of increasing NaCl concentrations on aquatic invertebrate drift, behavior, and survival. Field studies revealed that leaves were processed faster at upstream reference sites than at locations downstream from road salt point source inputs. However, it was sediment loading that resulted in partial or complete burial of leaf packs, that affected invertebrate activity and confounded normal leaf pack colonization. There were no significant differences that could be attributed to road salt between upstream and downstream locations in the diversity and composition of invertebrate functional feeding groups. Laboratory drift and acute exposure studies demonstrated that drift of Gammarus (Amphipoda) may be affected by NaCl at concentrations greater than 5000 mg/l for a 24-h period. This amphipod and two species of limnephilid caddisflies exhibited a dose response to salt treatments with 96-h LC50 values of 7700 and 3526 mg NaCl/l, respectively. Most other invertebrate species and individuals were unaffected by NaCl concentrations up to 10,000 mg/l for 24 and 96 h, respectively. PMID:12395833

  4. Comparative study of lead accumulation in different organs of perch (Perca fluviatilis) and its intestinal parasite Acanthocephalus lucii

    SciTech Connect

    Sures, B.; Taraschewski, H.; Jackwerth, E. )

    1994-02-01

    Lead is known as an important aquatic contaminant with different toxic effects on various organisms. Considerable data are available on lead in aquatic ecosystems including water, sediments, fishes and invertebrates. Until now, no quantitative investigations have been published comparing the heavy metal (Pb, Cd, Hg) content in parasites with that in their final or intermediate hosts, although such parasites are very prevalent in many fish and invertebrate populations. Only Brown and Pascoe (1989) reported that the amphipod Gammarus pulex parasitized with the acanthocephalan Pomphorhynchus laevis was two or three times more sensitive to cadmium at low exposure concentrations (2.1 [mu]g 1[sup [minus]1]) than uninfected conspecifics. The objective of the present study was to combine trace analytical and parasitological methods to investigate lead concentrations in different tissues (muscle, liver and intestine) of perch (Perca fluviatilis) and in the palaeacanthocephalan Acanthocephalus lucii parasitizing the intestine of these fishes. The fish were caught in the river Ruhr which drains the densely populated and industrialized Ruhr-district. 14 refs., 2 tabs.

  5. Effects of Fucus vesiculosus covering intertidal mussel beds in the Wadden Sea

    NASA Astrophysics Data System (ADS)

    Albrecht, A.; Reise, K.

    1994-06-01

    The brown alga Fucus vesiculosus forma mytili (Nienburg) Nienhuis covered about 70% of mussel bed ( Mytilus edulis) surface area in the lower intertidal zone of Königshafen, a sheltered sandy bay near the island of Sylt in the North Sea. Mean biomass in dense patches was 584 g ash-free dry weight m-2 in summer. On experimental mussel beds, fucoid cover enhanced mud accumulation and decreased mussel density. The position of mussels underneath algal canopy was mainly endobenthic (87% of mussels with >1/3 of shell sunk into mud). In the absence of fucoids, mussels generated epibenthic garlands (81% of mussels with <1/3 of shell buried in mud). Mussel density underneath fucoid cover was 40 to 73% of mussel density without algae. On natural beds, barnacles (Balanidae), periwinkles ( Littorina littorea) and crabs (particularly juveniles of Carcinus maenas) were significantly less abundant in the presence of fucoids, presumably because most of the mussels were covered with sediment, whereas in the absence of fucoids, epibenthic mussel clumps provided substratum as well as interstitial hiding places. The endobenthic macrofauna showed little difference between covered and uncovered mussel beds. On the other hand, grazing herbivores — the flat periwinkle Littorina mariae, the isopod Jaera albifrons and the amphipods Gammarus spp. — were more abundant at equivalent sites with fucoid cover. The patchy growth of Fucus vesiculosus on mussel beds in the intertidal Wadden Sea affects mussels and their epibionts negatively, but supports various herbivores and increases overall benthic diversity.

  6. Eaten alive: cannibalism is enhanced by parasites.

    PubMed

    Bunke, Mandy; Alexander, Mhairi E; Dick, Jaimie T A; Hatcher, Melanie J; Paterson, Rachel; Dunn, Alison M

    2015-03-01

    Cannibalism is ubiquitous in nature and especially pervasive in consumers with stage-specific resource utilization in resource-limited environments. Cannibalism is thus influential in the structure and functioning of biological communities. Parasites are also pervasive in nature and, we hypothesize, might affect cannibalism since infection can alter host foraging behaviour. We investigated the effects of a common parasite, the microsporidian Pleistophora mulleri, on the cannibalism rate of its host, the freshwater amphipod Gammarus duebeni celticus. Parasitic infection increased the rate of cannibalism by adults towards uninfected juvenile conspecifics, as measured by adult functional responses, that is, the rate of resource uptake as a function of resource density. This may reflect the increased metabolic requirements of the host as driven by the parasite. Furthermore, when presented with a choice, uninfected adults preferred to cannibalize uninfected rather than infected juvenile conspecifics, probably reflecting selection pressure to avoid the risk of parasite acquisition. By contrast, infected adults were indiscriminate with respect to infection status of their victims, probably owing to metabolic costs of infection and the lack of risk as the cannibals were already infected. Thus parasitism, by enhancing cannibalism rates, may have previously unrecognized effects on stage structure and population dynamics for cannibalistic species and may also act as a selective pressure leading to changes in resource use. PMID:26064614

  7. Ecological effects of rubble-mound breakwater construction and channel dredging at West Harbor, Ohio (western Lake Erie)

    USGS Publications Warehouse

    Manny, Bruce A.; Schloesser, Donald W.; Brown, Charles L.; French, John R. P., III

    1985-01-01

    The investigation reported herein indicated that breakwater construction and associated channel dredging activities by the US Army Corps of Engineers in western Lake Erie at the entrance to West Harbor (Ohio) had no detectable adverse impacts on the distributions or abundances of macrozoobenthos and fishes. Rather, increases were noted in the number of fish eggs and larvae and in the density and biomass of periphyton and macrozoobenthos on and near the breakwaters. The area also served as a nursery ground for 20 species of fishes both during and after construction and dredging activities. Colonization of the breakwaters by periphyton, primarily a green alga (Cladophora glomerata), diatoms (Gomphonema parvulum), and a bluegreen alga (Oscillatoria tenuis), and by macrozoobenthos, primarily worms (Oligochaeta), amphipods (Gammarus spp.), and midge larvae (Chironomidae), was rapid and extensive, indicating that the breakwaters provided new, favorable habitat for primary and secondary producer organisms. Marked adverse changes in water quality, especially reduced dissolved oxygen concentrations (25 mg/l), occurred around the entrance to West Harbor in 1983 following cessation of construction and dredging activities. These water quality changes, however, could not be ascribed with certainty to construction and dredging activities at West Harbor. Construction of additional breakwaters in the study area at that time by the State of Ohio served to confound determination of the responsible causal factors.

  8. The relative importance of diet-related and waterborne effects of copper for a leaf-shredding invertebrate.

    PubMed

    Zubrod, J P; Englert, D; Rosenfeldt, R R; Wolfram, J; Lüderwald, S; Wallace, D; Schnetzer, N; Schulz, R; Bundschuh, M

    2015-10-01

    Copper (Cu) exposure can increase leaf-associated fungal biomass, an important food component for leaf-shredding macroinvertebrates. To test if this positive nutritional effect supports the physiological fitness of these animals and to assess its importance compared to waterborne toxicity, we performed a 24-day-bioassay in combination with a 2×2 factorial design using the amphipod shredder Gammarus fossarum and a field-relevant Cu concentration of 25 μg/L (n = 65). Waterborne toxicity was negligible, while gammarids fed leaves exposed to Cu during microbial colonization exhibited a near-significant impairment in growth (∼30%) and a significantly reduced lipid content (∼20%). These effects appear to be governed by dietary uptake of Cu, which accumulated in leaves as well as gammarids and likely overrode the positive nutritional effect of the increased fungal biomass. Our results suggest that for adsorptive freshwater contaminants dietary uptake should be evaluated already during the registration process to safeguard the integrity of detritus-based ecosystems. PMID:26000755

  9. Eaten alive: cannibalism is enhanced by parasites

    PubMed Central

    Bunke, Mandy; Alexander, Mhairi E.; Dick, Jaimie T. A.; Hatcher, Melanie J.; Paterson, Rachel; Dunn, Alison M.

    2015-01-01

    Cannibalism is ubiquitous in nature and especially pervasive in consumers with stage-specific resource utilization in resource-limited environments. Cannibalism is thus influential in the structure and functioning of biological communities. Parasites are also pervasive in nature and, we hypothesize, might affect cannibalism since infection can alter host foraging behaviour. We investigated the effects of a common parasite, the microsporidian Pleistophora mulleri, on the cannibalism rate of its host, the freshwater amphipod Gammarus duebeni celticus. Parasitic infection increased the rate of cannibalism by adults towards uninfected juvenile conspecifics, as measured by adult functional responses, that is, the rate of resource uptake as a function of resource density. This may reflect the increased metabolic requirements of the host as driven by the parasite. Furthermore, when presented with a choice, uninfected adults preferred to cannibalize uninfected rather than infected juvenile conspecifics, probably reflecting selection pressure to avoid the risk of parasite acquisition. By contrast, infected adults were indiscriminate with respect to infection status of their victims, probably owing to metabolic costs of infection and the lack of risk as the cannibals were already infected. Thus parasitism, by enhancing cannibalism rates, may have previously unrecognized effects on stage structure and population dynamics for cannibalistic species and may also act as a selective pressure leading to changes in resource use. PMID:26064614

  10. An acanthocephalan parasite boosts the escape performance of its intermediate host facing non-host predators.

    PubMed

    Medoc, V; Beisel, J-N

    2008-07-01

    Among the potential effects of parasitism on host condition, the 'increased host abilities' hypothesis is a counterintuitive pattern which might be predicted in complex-life-cycle parasites. In the case of trophic transmission, a parasite increasing its intermediate host's performance facing non-host predators improves its probability of transmission to an adequate, definitive host. In the present study, we investigated the cost of infection with the acanthocephalan Polymorphus minutus on the locomotor/escape performance of its intermediate host, the crustacean Gammarus roeseli. This parasite alters the behaviour of its intermediate host making it more vulnerable to predation by avian definitive hosts. We assessed the swimming speeds of gammarids using a stressful treatment and their escape abilities under predation pressure. Despite the encystment of P. minutus in the abdomen of its intermediate host, infected amphipods had significantly higher swimming speeds than uninfected ones (increases of up to 35%). Furthermore, when interacting with the non-host crustacean predator Dikerogammarus villosus, the highest escape speeds and greatest distances covered by invertebrates were observed for parasitized animals. The altered behaviour observed among the manipulated invertebrates supported the 'increased host abilities' hypothesis, which has until now remained untested experimentally. The tactic of increasing the ability of infected intermediate hosts to evade potential predation attempts by non-host species is discussed. PMID:18477417

  11. Interaction of nemertines and their prey on tidal flats

    NASA Astrophysics Data System (ADS)

    Thiel, Martin; Reise, Karsten

    Two common nemertines of the European Wadden Sea, Lineus viridis and Amphiporus lactifloreus, occur preferentially in clusters of mussels, spread over sedimentary flats in the upper intertidal near the island of Sylt. The heteronemertine L. viridis preys mainly on the polychaete Nereis diversicolor. The hoplonemertine A. lactifloreus feeds almost exclusively on the amphipod Gammarus locusta. Abundance of both predators and their respective prey in the field showed inverse relationships. Experimentally increased numbers of L. viridis in clusters of mussels caused a gradual decrease of nereid abundance in the sediment underneath over a period of 1 month, suggesting that losses of individuals were caused by prey capture. Experimentally increased numbers of A. lactifloreus were followed by an escape response of gammarids from clusters of mussels within 2 d. In aquaria, both prey species exhibited prolonged swimming activity when their respective predators lurked at the bottom. We conclude that escape behaviour in N. diversicolor may be only effective during its migrant phases, while G. locusta is permanently on the alert to avoid encounters with its predator. This refuging behaviour in response to endobenthic predators has strong implications on prey distribution, while the actual consumption of prey may be relatively modest. Enclosure experiments in the field and in aquaria lead to overestimates of prey capture when refuging behaviour is not accounted for.

  12. EFFECT OF WATER TEMPERATURE AND PH ON TOXICITY OF TERBUFOS, TRICHLORFON, 4-NITROPHENOL, AND 2,4-DINITROPHENOL TO THE AMPHID GAMMARUS PSEUDOLIMNAEUS AND RAINBOW TROUT (ONCORHYNCHUS MYKISS)

    EPA Science Inventory

    Water temperature and pH affect toxicity of most chemicals to aquatic organisms. bjectives of this study were to determine: (1) individual and interactive effects of water temperature (7, 12, 17 degrees C), pH (6.5, 7.5, 8.5, 9.5), and time on the acute toxicity of terbufos, tric...

  13. [PATTERNS IN CIRCULATION AND TRANSMISSION OF MARINE BIRD PARASITES IN HIGH ARCTIC: A CASE OF ACANTHOCEPHALAN POLYMORPHUS PHIPPSI (PALAEACANTHOCEPHALA, POLYMORPHIDAE)].

    PubMed

    Galaktionov, K V; Atrashkevich, G I

    2015-01-01

    This study, based on the materials on parasitic infection of marine birds and invertebrates in Frantz Josef Land (FJL) collected in 1991-1993, focussed on the acanthocephalan Polymorphus phippsi. We identified this parasite, confirmed its species status and analysed its circulation and transmission patterns in high Arctic. The causes of its erroneous identification as P. minutus in several studies were also examined. In contrast to P. minutus, the transmission of P. phippsi is realized in marine coastal ecosystems. Its' main intermediate host in the Arctic is the amphipod Gammarus (Lagunogammarus) setosus, commonin coastal. areas of the shelf zone throughout the Arctic basin. P. phippsi population in FJL and the entire European Arctic is on the whole maintained by a single obligate final host, the common eider Somateria mollissima. Prevalence (P) of P. phippsi in this bird reached 100 %, with the maximal infection intensity (IImax) of 1188 and the mean abundance (MA) of 492.1. Other species of birds found to be infected with P. phippsi (Arctic turn, black guillemot, purple sandpiper and several gulls) are facultative and/or eliminative hosts. The most heavily infected birds were Arctic terns (P = 72.7%, IImax = 227, MA = = 47.1), which contained single mature acanthocephalans. For one of the FJL regions, infections flows of P. phippsi through various host categories were calculated. Involvement of birds unrelated to the common eider into the circulation of P. phippsi is facilitated by their feeding character in the Arctic. While coastal crustaceans are abundant, fish food is relatively scarce (polar cod, snailfishes), and so amphipods make up a considerable part of the diet of marine birds in FJL, if not most of it, as for instance in case of Arctic tern. This promotes an easy entry of the larvae of crustaceans-parasitizing helminthes (cestodes and acanthocephalans, including cystacanths P. phippsi) into non-specific hosts and opens broad colonization possibilities

  14. Seasonal Variation, Export Dynamics and Consumption of Freshwater Invertebrates in an Estuarine Environment

    NASA Astrophysics Data System (ADS)

    Williams, D. D.; Williams, N. E.

    1998-03-01

    In the Aber Estuary, North Wales, significant numbers of freshwater benthic invertebrates occurred in the tidal freshwater area. Distinct seasonal patterns were observed in their longitudinal zonation which appeared to be unrelated to variations in tidal inundation. The December extension downstream of freshwater taxa is hypothesized to be in response to decreasing water temperatures. In April, larvae/nymphs of the Trichoptera (caddisflies), Ephemeroptera (mayflies) and Plecoptera (stoneflies) ranged as far as a site inundated by 80·9% of all high tides, and larval Elmidae and Chironomidae (midges) occurred at the most marine site (inundated twice daily by all high tides). In July, with the exception of the Chironomidae, the range of most aquatic insects had contracted to the upper estuary. Although, in general, densities of aquatic insects decreased towards the lower estuary, significant densities persisted there. For example, maxima of 3514 chironomid larvae and 48 caddisfly larvae m -2were recorded at the 80·9% inundation site. An estimated 31×10 6freshwater invertebrates (weighing 62·6 kg), per annum, passed from fresh water into salt water across any given transect along the estuary. In comparison, the annual influx of invertebrates carried upstream by incoming tides was estimated to be 1·9×10 6(6·2%; weighing 2·5 kg). Predominant in the downstream drift were the larvae/nymphs and/or pupae of chironomids, mayflies, stoneflies and caddisflies. The ' reverse ' drift comprised mainly copepods, ostracods, amphipods and oligochaetes. Mites and the brackishwater amphipod Gammarus zaddachicommonly moved in both directions. Highest drift densities occurred in July, whereas the lowest densities occurred in late autumn and winter. Multiple regression analysis showed no relationship between total drift or ' reverse ' drift densities and any of the measured environmental variables. Many of the freshwater invertebrates appeared not to die upon passing into tidal

  15. The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions

    PubMed Central

    Raupach, Michael J.; Barco, Andrea; Steinke, Dirk; Beermann, Jan; Laakmann, Silke; Mohrbeck, Inga; Neumann, Hermann; Kihara, Terue C.; Pointner, Karin; Radulovici, Adriana; Segelken-Voigt, Alexandra; Wesse, Christina; Knebelsberger, Thomas

    2015-01-01

    During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for 198 (96.6%) of the analyzed species. Six species were characterized by two BINs (2.9%), and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%). Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%). Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761), underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequences. PMID:26417993

  16. Specificity in Mesograzer-Induced Defences in Seagrasses.

    PubMed

    Martínez-Crego, Begoña; Arteaga, Pedro; Ueber, Alexandra; Engelen, Aschwin H; Santos, Rui; Molis, Markus

    2015-01-01

    Grazing-induced plant defences that reduce palatability to herbivores are widespread in terrestrial plants and seaweeds, but they have not yet been reported in seagrasses. We investigated the ability of two seagrass species to induce defences in response to direct grazing by three associated mesograzers. Specifically, we conducted feeding-assayed induction experiments to examine how mesograzer-specific grazing impact affects seagrass induction of defences within the context of the optimal defence theory. We found that the amphipod Gammarus insensibilis and the isopod Idotea chelipes exerted a low-intensity grazing on older blades of the seagrass Cymodocea nodosa, which reflects a weak grazing impact that may explain the lack of inducible defences. The isopod Synischia hectica exerted the strongest grazing impact on C. nodosa via high-intensity feeding on young blades with a higher fitness value. This isopod grazing induced defences in C. nodosa as indicated by a consistently lower consumption of blades previously grazed for 5, 12 and 16 days. The lower consumption was maintained when offered tissues with no plant structure (agar-reconstituted food), but showing a reduced size of the previous grazing effect. This indicates that structural traits act in combination with chemical traits to reduce seagrass palatability to the isopod. Increase in total phenolics but not in C:N ratio and total nitrogen of grazed C. nodosa suggests chemical defences rather than a modified nutritional quality as primarily induced chemical traits. We detected no induction of defences in Zostera noltei, which showed the ability to replace moderate losses of young biomass to mesograzers via compensatory growth. Our study provides the first experimental evidence of induction of defences against meso-herbivory that reduce further consumption in seagrasses. It also emphasizes the relevance of grazer identity in determining the level of grazing impact triggering resistance and compensatory

  17. Comparison of macroinvertebrate-derived stream quality metrics between snag and riffle habitats

    USGS Publications Warehouse

    Stepenuck, K.F.; Crunkilton, R.L.; Bozek, Michael A.; Wang, L.

    2008-01-01

    We compared benthic macroinvertebrate assemblage structure at snag and riffle habitats in 43 Wisconsin streams across a range of watershed urbanization using a variety of stream quality metrics. Discriminant analysis indicated that dominant taxa at riffles and snags differed; Hydropsychid caddisflies (Hydropsyche betteni and Cheumatopsyche spp.) and elmid beetles (Optioservus spp. and Stenemlis spp.) typified riffles, whereas isopods (Asellus intermedius) and amphipods (Hyalella azteca and Gammarus pseudolimnaeus) predominated in snags. Analysis of covariance indicated that samples from snag and riffle habitats differed significantly in their response to the urbanization gradient for the Hilsenhoff biotic index (BI), Shannon's diversity index, and percent of filterers, shredders, and pollution intolerant Ephemeroptera, Plecoptera, and Trichoptera (EPT) at each stream site (p ??? 0.10). These differences suggest that although macroinvertebrate assemblages present in either habitat type are sensitive to detecting the effects of urbanization, metrics derived from different habitats should not be intermixed when assessing stream quality through biomonitoring. This can be a limitation to resource managers who wish to compare water quality among streams where the same habitat type is not available at all stream locations, or where a specific habitat type (i.e., a riffle) is required to determine a metric value (i.e., BI). To account for differences in stream quality at sites lacking riffle habitat, snag-derived metric values can be adjusted based on those obtained from riffles that have been exposed to the same level of urbanization. Comparison of nonlinear regression equations that related stream quality metric values from the two habitat types to percent watershed urbanization indicated that snag habitats had on average 30.2 fewer percent EPT individuals, a lower diversity index value than riffles, and a BI value of 0.29 greater than riffles. ?? 2008 American Water

  18. Trophic relationships on a fucoid shore in south-western Iceland as revealed by stable isotope analyses, laboratory experiments, field observations and gut analyses

    NASA Astrophysics Data System (ADS)

    Steinarsdóttir, M. B.; Ingólfsson, A.; Ólafsson, E.

    2009-04-01

    Rocky shores in the North Atlantic are known for their zonation patterns of both algae and animals, which can be expected to greatly affect food availability to consumers at different height levels on the shore. We tested the hypothesis that consumers would feed on the most abundant suitable food source in their surroundings. In total 36 species/taxa of common primary producers and consumers were sampled for stable isotope analyses from a sheltered fucoid shore at Hvassahraun in south-western Iceland. A selection of these species was also collected seasonally and from different height levels. Feeding experiments, field observations and gut analyses were also conducted. Our results were in good overall agreement with pre-existing knowledge of trophic relationships in the rocky intertidal. Consumers often appeared to be assimilating carbon and nitrogen from the most common diet in their immediate surroundings. The predator Nucella lapillus was thus feeding on different prey at different height levels in accordance with different densities of prey species. When tested in the laboratory, individuals taken from low on the shore would ignore the gastropod Littorina obtusata, uncommon at that height level, even when starved, while individuals from mid-shore readily ate the gastropod. This indicated that some kind of learned behaviour was involved. There were, however, important exceptions, most noteworthy the relatively small contribution to herbivores, both slow moving (the gastropod L. obtusata) and fast moving (the isopod Idotea granulosa and the amphipod Gammarus obtusatus) of the dominant alga at this site, Ascophyllum nodosum. The recent colonizer Fucus serratus seemed to be favoured. Selective feeding was indicated both by isotope signatures as well as by results of feeding experiments. Seasonal migrations of both slow and fast moving species could partly explain patterns observed.

  19. Wind effects on prey availability: How northward migrating waders use brackish and hypersaline lagoons in the sivash, Ukraine

    NASA Astrophysics Data System (ADS)

    Verkuil, Yvonne; Koolhaas, Anita; Van Der Winden, Jan

    Large numbers of waders migrating northward in spring use the Sivash, a large system of shallow, brackish and hypersaline lagoons in the Black Sea and Azov Sea region (Ukraine). The bottoms of these lagoons are often uncovered by the wind. Hence, for waders the time and space available for feeding depend on wind conditions. In hypersaline lagoons the benthic and pelagic fauna was very poor, consisting mainly of chironomid larvae (0.19 g AFDM·m -2) and brine shrimps Artemia salina, respectively. Brine shrimp abundance was correlated with salinity, wind force, wind direction and water depth. Dunlin Calidris alpina and curlew sandpiper Calidris ferruginea were the only species feeding on brine shrimp. As brine shrimp densities are higher in deeper water, smaller waders such as broad-billed sandpipers Limicola falcinellus are too short-legged to reach exploitable densities of brine shrimp. In brackish lagoons the benthic and pelagic fauna was rich, consisting of polychaetes, bivalves, gastropods, chironomid larvae, isopods and amphipods (8.9 to 30.5 g AFDM·m -2), but there were no brine shrimps. Prey biomass increased with the distance from the coast, being highest on the site that was most frequently inundated. Dunlin, broad-billed sandpiper and grey plover Pluvialis squatarola were the most abundant birds in the brackish lagoon. Due to the effects of wind-tides only a small area was usually available as a feeding site. Gammarus insensibilis was the alternative prey resource in the water layer, and their density varied with wind direction in the same way as brine shrimp. Curlew sandpipers and dunlins in the hypersaline lagoons and broad-billed sandpipers in the brackish lagoons often changed feeding sites, probably following the variation in prey availability. Only because of the large size and variety of lagoons are waders in the Sivash always able to find good feeding sites.

  20. Studying the movement behavior of benthic macroinvertebrates with automated video tracking.

    PubMed

    Augusiak, Jacqueline; Van den Brink, Paul J

    2015-04-01

    Quantifying and understanding movement is critical for a wide range of questions in basic and applied ecology. Movement ecology is also fostered by technological advances that allow automated tracking for a wide range of animal species. However, for aquatic macroinvertebrates, such detailed methods do not yet exist. We developed a video tracking method for two different species of benthic macroinvertebrates, the crawling isopod Asellus aquaticus and the swimming fresh water amphipod Gammarus pulex. We tested the effects of different light sources and marking techniques on their movement behavior to establish the possibilities and limitations of the experimental protocol and to ensure that the basic handling of test specimens would not bias conclusions drawn from movement path analyses. To demonstrate the versatility of our method, we studied the influence of varying population densities on different movement parameters related to resting behavior, directionality, and step lengths. We found that our method allows studying species with different modes of dispersal and under different conditions. For example, we found that gammarids spend more time moving at higher population densities, while asellids rest more under similar conditions. At the same time, in response to higher densities, gammarids mostly decreased average step lengths, whereas asellids did not. Gammarids, however, were also more sensitive to general handling and marking than asellids. Our protocol for marking and video tracking can be easily adopted for other species of aquatic macroinvertebrates or testing conditions, for example, presence or absence of food sources, shelter, or predator cues. Nevertheless, limitations with regard to the marking protocol, material, and a species' physical build need to be considered and tested before a wider application, particularly for swimming species. Data obtained with this approach can deepen the understanding of population dynamics on larger spatial scales and

  1. Specificity in Mesograzer-Induced Defences in Seagrasses

    PubMed Central

    Martínez-Crego, Begoña; Arteaga, Pedro; Ueber, Alexandra; Engelen, Aschwin H.; Santos, Rui; Molis, Markus

    2015-01-01

    Grazing-induced plant defences that reduce palatability to herbivores are widespread in terrestrial plants and seaweeds, but they have not yet been reported in seagrasses. We investigated the ability of two seagrass species to induce defences in response to direct grazing by three associated mesograzers. Specifically, we conducted feeding-assayed induction experiments to examine how mesograzer-specific grazing impact affects seagrass induction of defences within the context of the optimal defence theory. We found that the amphipod Gammarus insensibilis and the isopod Idotea chelipes exerted a low-intensity grazing on older blades of the seagrass Cymodocea nodosa, which reflects a weak grazing impact that may explain the lack of inducible defences. The isopod Synischia hectica exerted the strongest grazing impact on C. nodosa via high-intensity feeding on young blades with a higher fitness value. This isopod grazing induced defences in C. nodosa as indicated by a consistently lower consumption of blades previously grazed for 5, 12 and 16 days. The lower consumption was maintained when offered tissues with no plant structure (agar-reconstituted food), but showing a reduced size of the previous grazing effect. This indicates that structural traits act in combination with chemical traits to reduce seagrass palatability to the isopod. Increase in total phenolics but not in C:N ratio and total nitrogen of grazed C. nodosa suggests chemical defences rather than a modified nutritional quality as primarily induced chemical traits. We detected no induction of defences in Zostera noltei, which showed the ability to replace moderate losses of young biomass to mesograzers via compensatory growth. Our study provides the first experimental evidence of induction of defences against meso-herbivory that reduce further consumption in seagrasses. It also emphasizes the relevance of grazer identity in determining the level of grazing impact triggering resistance and compensatory

  2. Response of invertebrates from the hyporheic zone of chalk rivers to eutrophication and land use.

    PubMed

    Pacioglu, Octavian; Moldovan, Oana Teodora

    2016-03-01

    Whereas the response of lotic benthic macroinvertebrates to different environmental stressors is a widespread practice nowadays in assessing the water and habitat quality, the use of hyporheic zone invertebrates is still in its infancy. In this study, classification and regression trees analysis were employed in order to assess the ecological requirements and the potential as bioindicators for the hyporheic zone invertebrates inhabiting four lowland chalk rivers (south England) with contrasting eutrophication levels (based on surface nitrate concentrations) and magnitude of land use (based on percentage of fine sediments load and median interstitial space). Samples of fauna, water and sediment were sampled twice, during low (summer) and high (winter) groundwater level, at depths of 20 and 35 cm. Certain groups of invertebrates (Glossosomatidae and Psychomyiidae caddisflies, and riffle beetles) proved to be good indicators of rural catchments, moderately eutrophic and with high fine sediment load. A diverse community dominated by microcrustaceans (copepods and ostracods) were found as good indicators of highly eutrophic urban streams, with moderate-high fine sediment load. However, the use of other taxonomic groups (e.g. chironomids, oligochaetes, nematodes, water mites and the amphipod Gammarus pulex), very widespread in the hyporheic zone of all sampled rivers, is of limited use because of their high tolerance to the analysed stressors. We recommend the use of certain taxonomic groups (comprising both meiofauna and macroinvertebrates) dwelling in the chalk hyporheic zone as indicators of eutrophication and colmation and, along with routine benthic sampling protocols, for a more comprehensive water and habitat quality assessment of chalk rivers. PMID:26531711

  3. Waves affect predator-prey interactions between fish and benthic invertebrates.

    PubMed

    Gabel, Friederike; Stoll, Stefan; Fischer, Philipp; Pusch, Martin T; Garcia, Xavier-François

    2011-01-01

    Little is known about the effects of waves on predator-prey interactions in the littoral zones of freshwaters. We conducted a set of mesocosm experiments to study the differential effects of ship- and wind-induced waves on the foraging success of littoral fish on benthic invertebrates. Experiments were conducted in a wave tank with amphipods (Gammarus roeseli) as prey, and age-0 bream (Abramis brama, B0), age-0 and age-1 dace (Leuciscus leuciscus, D0 and D1) as predators. The number of gammarids suspended in the water column was higher in the wave treatments compared to a no-wave control treatment, especially during pulse waves mimicking ship-induced waves in comparison to continuous waves mimicking wind-induced waves. The resulting higher prey accessibility in the water column was differently exploited by the three types of predatory fish. D0 and D1 showed significantly higher foraging success in the pulse wave treatment than in the continuous and control treatments. The foraging success of D0 appears to be achieved more easily, since significantly higher swimming activity and more foraging attempts were recorded only for D1 under the wave treatments. In contrast, B0 consumed significantly fewer gammarids in both wave treatments than in the control. Hence, waves influenced predator-prey interactions differently depending on wave type and fish type. It is expected that regular exposure to ship-induced waves can alter littoral invertebrate and fish assemblages by increasing the predation risk for benthic invertebrates that are suspended in the water column, and by shifting fish community compositions towards species that benefit from waves. PMID:21104276

  4. Influence of salinity regime on the food-web structure and feeding ecology of fish species from Mediterranean coastal lagoons

    NASA Astrophysics Data System (ADS)

    Prado, Patricia; Vergara, Carolina; Caiola, Nuno; Ibáñez, Carles

    2014-02-01

    Dual δ15N and δ13C analyses and estimates of biomass were used to characterize the food webs of valuable fish species in three coastal lagoons of the Ebro Delta subjected to contrasting salinity regimes (polyhaline in the Tancada lagoon, mesohaline in the Encanyissada and oligohaline in the Clot lagoon). The δ13C signatures of the entire food-web including primary producers, sediment organic matter and consumers showed the most enriched values in the Tancada lagoon (from approx. -4.8‰ in sediments to -19.7‰ in fish) and the most depleted ones in the Clot lagoon (from approx. -11.4‰ in sediments to -25.4‰ in fish), consistent with dominant contributions from marine and continental sources, respectively. For δ15N, particularly high values were detected in the submersed vegetation (11.3 ± 0.3‰) together with more enriched sediment values at lower salinities (by approx. 2.5‰), suggesting that historical loadings of agricultural fertilizers are still retained by the systems and transmitted across trophic levels. Negative relationships between δ15N and salinity were also observed for the amphipod Gammarus aequicauda and the isopod Sphaeroma hookeri, suggesting some consumption of accumulated and resuspended detrital material. In contrast, δ15N signatures of fish showed lower values and inconsistent patterns, possibly because most species have a seasonal use of the lagoons. The biomass of fish species did not show a clear effect of the salinity regime (except for the mosquitofish Gambusia holbrookii), but results for mixing models suggest a diet shift from higher contribution of zooplankton size fractions in the Encanyissada (from 57 to 73%) to macrofauna at the other lagoons (from 40 to 67%). We suggest that alterations in salinity might modify the trophic dynamics of the systems from benthic to planktonic pathways, without large-scale differences in δ15N of fish suggestive of similar trophic levels.

  5. Tissue distribution and histopathological effects of dietary methylmercury in benthic grubby Myoxocephalus aenaeus

    SciTech Connect

    Pelletier, E.; Audet, C.

    1995-05-01

    There is a need to test deterministic models predicting the behavior and effects of chemicals on aquatic systems by conducting experiments with more than one trophic step at a time. This approach requires the set-up of an experimental food chain in pounds or mesocosm facilities which can be used for dietary uptake studies and assessment of sublethal stress induced by contaminated food. In the course of our current research program at the INRS marine mesocosms facilities, a model benthic food chain including inter- and sub-tidal species such as the mussel (Mytilus edulis), clam (Mya arenaria), starfish (Leptasterias polaris), polychaete (Nereis virens), amphipod (Gammarus sp.), gastropod (Buccinum undatum), and fishes (Pleuronectec americanus, Myoxocephalus aenaeus), is used for testing food uptake models and for the development of sublethal toxicity tests which could be used in the environmental assessment of coastal and estuarine waters. Among these test organisms, the grubby (M. aenaeus) is a small coastal fish (12-15 cm) characterized by a broad head. The grubby is tolerant of water temperature and salinity variations and lives on a wide variety of bottom strata at low depths. The grubby is carnivorous and consumes a wide variety of molluscs and the young of many species of fish. Because of its size, its estuarine and coastal distribution and its large spectrum of prey, this species was seen as an ideal fish to fit into our experimental food chain model. This paper reports a preliminary experiment designed to measure distribution of mercury in tissues and to test the response of various histopathological and biochemical stress indicators in grubby exposed to dietary contamination by methylmercury (MeHg) for a 20-day exposure period. MeHg was chosen because it is rapidly bioaccumulated by most living organisms and its toxicity has been studied for decades in numerous aquatic ecosystems. 17 refs., 2 tabs.

  6. The distribution of the amphipod Corophium arenarium in the Dutch Wadden Sea: relationships with sediment composition and the presence of cockles and lugworms

    NASA Astrophysics Data System (ADS)

    Flach, E. C.

    On the tidal flats in the Dutch Wadden Sea Corophium volutator is a dominant species of the upper intertidal zone; the closely related Corophium arenarium is usually found in the lower zone, but only in low densities (a few hundreds per m 2). A survey in the Dutch Wadden Sea showed that this zonation pattern was only present when a muddy sediment was found in the upper zone and a sandy in the lower zone. C. arenarium was restricted to sandy sediments, C. volutator to muddy sediments. Where a sandy sediment was found in the upper intertidal zone, C. arenarium locally occurred in relatively high densities (a few thousands per m 2). An aquarium experiment showed that C. arenarium actively avoided muddy sediments. Field experiments were carried out to study the influence of other macrozoobenthic species (known to affect the related C. volutator) on the abundance of C. arenarium. Within large defaunated areas small plots were stocked with different densities of the lugworm Arenicola marina and the cockle Cerastoderma edule. In small plots within a natural benthic community densities of these species were also augmented or (in A. marina) reduced. Strongly negative density-dependent effects of both A. marina and C. edule were found on the abundance of C. arenarium. In the natural situation, its densities showed A. marina to be the most important factor in determining the abundance of C. arenarium. In particular the removal of lugworms caused a strong increase in C. arenarium densities. These results agreed with the distribution of these species along a transect perpendicular to the shore of Schiermonnikoog, where a significant negative correlation was found between the densities of A. marina and C. arenarium. Aquarium experiments showed that the negative effect of cockles and lugworms must be due to migration rather than mortality in C. arenarium.

  7. SEASONAL CHANGES IN THE AMPHIPOD FAUNA OF 'MICROCIONA PROLIFERA' (ELLIS AND SOLANDER) (PORIFERA: DEMOSPONGIA) AND ASSOCIATED SPONGES IN A SHALLOW SALT-MARSH CREEK

    EPA Science Inventory

    Between September 1976 and August 1978, samples of four species of sponge, Microciona prolifera, Haliclona loosanoffi, Lissodendoryx, and Halichondria bowerbanki were collected from subtidal shell debris in a North Edisto River, South Carolina saltmarsh creek and associated amphi...

  8. ECDYSTEROID CONCENTRATIONS THROUGH VARIOUS LIFE-STAGES OF THE MEIOBENTHIC HARPACTICOID COPEPOD, AMPHIASCUS TENUIREMIS AND THE BENTHIC ESTUARINE AMPHIPOD, LEPTOCHEIRUS PLUMULOSUS. (R827397)

    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...

  9. Leucothoe kawesqari, a new amphipod from Bernardo O'Higgins National Park (Chile), with remarks on the genus in the Magellan Region (Crustacea, Peracarida).

    PubMed

    Esquete, Patricia; Aldea, Cristian

    2015-01-01

    Although the genus Leucothoe has been reported repeatedly in the Magellan Region, the citations in the Channels and Fjords Ecoregion were either unidentified or attributed to the previously considered cosmopolitan Leucothoe spinicarpa. In this work, Leucothoe kawesqari sp. n. is described, which can be distinguished from other species of the genus in the Southern Ocean by having eyes present, epimeral plates with no setae, anterior coxae not acutely produced or excavate, coxa 5 slightly bilobed, accessory flagellum present, mandibular palp article 3 shorter than ½ article 2, pereopods 5-7 basis expanded, ovoid, posterior margin weakly crenulate and telson apex irregularly truncated. The new species was found in hard substrates, both unvegetated and with macroalgae, mainly in kelp forest of Macrocystis pyrifera. PMID:26798246

  10. Caribboecetes progreso, a new species of sand-dwelling amphipod (Amphipoda: Corophiidea: Ischyroceridae) from the Gulf of Mexico, with a key for the genus.

    PubMed

    Paz-Ríos, Carlos E; Ardisson, Pedro-Luis

    2013-01-01

    A new species of the genus Caribboecetes Just, 1983 is described and illustrated from specimens collected on sandy bottoms of the northern Yucatan Peninsula, southeastern Gulf of Mexico. Caribboecetes progreso sp. nov. differs from the closely related species Caribboecetes barbadensis Just, 1983 and Caribboecetes jenikarpae Just, 1984 by the inflated triangular anterolateral flange on basis of gnathopod 2, and from Caribboecetes justi Ortiz & Lemaitre, 1997 by the setose anterolateral surface of coxal plate 7 and basis of pereopod 7. Ecological notes for the new species, a morphological comparison, map of distribution and key for all members in the genus are also provided. PMID:26269839

  11. Leucothoe kawesqari, a new amphipod from Bernardo O’Higgins National Park (Chile), with remarks on the genus in the Magellan Region (Crustacea, Peracarida)

    PubMed Central

    Esquete, Patricia; Aldea, Cristian

    2015-01-01

    Abstract Although the genus Leucothoe has been reported repeatedly in the Magellan Region, the citations in the Channels and Fjords Ecoregion were either unidentified or attributed to the previously considered cosmopolitan Leucothoe spinicarpa. In this work, Leucothoe kawesqari sp. n. is described, which can be distinguished from other species of the genus in the Southern Ocean by having eyes present, epimeral plates with no setae, anterior coxae not acutely produced or excavate, coxa 5 slightly bilobed, accessory flagellum present, mandibular palp article 3 shorter than ½ article 2, pereopods 5–7 basis expanded, ovoid, posterior margin weakly crenulate and telson apex irregularly truncated. The new species was found in hard substrates, both unvegetated and with macroalgae, mainly in kelp forest of Macrocystis pyrifera. PMID:26798246

  12. Redescription of two subterranean amphipods Niphargus molnari Méhely, 1927 and Niphargus gebhardti Schellenberg, 1934 (Amphipoda, Niphargidae) and their phylogenetic position

    PubMed Central

    Angyal, Dorottya; Balázs, Gergely; Zakšek, Valerija; Krízsik, Virág; Fišer, Cene

    2015-01-01

    Abstract A detailed redescription of two endemic, cave-dwelling niphargid species of the Hungarian Mecsek Mts., Niphargus molnari Méhely, 1927 and Niphargus gebhardti Schellenberg, 1934 is given based on newly collected material. Morphology was studied under light microscopy and with scanning electon microscopy. Morphological descriptions are complemented with mitochondrial cytochrome c oxidase subunit I (COI) sequences as barcodes for both species and with notes on their ecology. Using three independent molecular markers we showed that Niphargus gebhardti belongs to the clade distributed between Central and Eastern Europe, whereas phylogenetic relationship of Niphargus molnari to the rest of Niphargus species is not clear. The two species from the Mecsek Mts. are phylogenetically not closely related. Both species need to be treated as vulnerable according to IUCN Red List of Threatened Species. PMID:26175603

  13. Geographic range and structure of cryptic genetic diversity among Pacific North American populations of the non-native amphipod Grandidierella japonica

    EPA Science Inventory

    Reconstructing the invasion history of aquatic invasive species can enhance understanding of invasion risks by recognizing areas most susceptible to invasion and forecasting future spread based on past patterns of population expansion. Here we reconstruct the invasion history of ...

  14. The influence of four macrozoobenthic species on the abundance of the amphipod Corophium volutator on tidal flats of the Wadden Sea

    NASA Astrophysics Data System (ADS)

    Flach, E. C.

    On the tidal flats of the Wadden Sea, a zonation pattern can be found with Corophium volutator and Nereis diversicolor as the dominating species of the upper intertidal zone and Arenicola marina and Cerastoderma edule as the dominating species of the lower zone. As C. volutator can live under a great variety of physical conditions, its restriction to higher areas might result from biotic interactions. This was investigated by field experiments on a tidal flat in the westernmost part of the Wadden Sea. Within large depopulated areas, small plots were recolonized with different densities of N. diversicolor, A. marina, C. edule and Macoma balthica and the subsequent settlement and dynamics of C. volutator were studied. In addition, A. marina and/or C. edule were added to or removed from small plots within a natural benthic community. Neither the presence of M. balthica not that of N. diversicolor significantly affected the abundance of C. volutator. A strongly negative effect was found of C. edule when present in high densities, whereas A. marina negatively affected C. volutator abundance already at relatively low densities. Local removals of A. marina and C. edule from their own zone resulted in increases of Corophium numbers at these locations and local additions of these species within the Corophium zone resulted in decreases of Corophium numbers at these locations. It is suggested that the major species to restrict C. volutator effectively to the upper tidal zone is A. marina.

  15. Cadmium risks to freshwater life: derivation and validation of low-effect criteria values using laboratory and field studies

    USGS Publications Warehouse

    Mebane, Christopher A.

    2006-01-01

    In 2001, the U.S. Environmental Protection Agency (EPA) released updated aquatic life criteria for cadmium. Since then, additional data on the effects of cadmium to aquatic life have become available from studies supported by the EPA, Idaho Department of Environmental Quality (IDEQ), and the U.S. Geological Survey, among other sources. Updated data on the effects of cadmium to aquatic life were compiled and reviewed and low-effect concentrations were estimated. Low-effect values were calculated using EPA's guidelines for deriving numerical national water-quality criteria for the protection of aquatic organisms and their uses. Data on the short-term (acute) effects of cadmium on North American freshwater species that were suitable for criteria derivation were located for 69 species representing 57 genera and 33 families. For longer-term (chronic) effects of cadmium on North American freshwater species, suitable data were located for 28 species representing 21 genera and 17 families. Both the acute and chronic toxicity of cadmium were dependent on the hardness of the test water. Hardness-toxicity regressions were developed for both acute and chronic datasets so that effects data from different tests could be adjusted to a common water hardness. Hardness-adjusted effects values were pooled to obtain species and genus mean acute and chronic values, which then were ranked by their sensitivity to cadmium. The four most sensitive genera to acute exposures were, in order of increasing cadmium resistance, Oncorhynchus (Pacific trout and salmon), Salvelinus ('char' trout), Salmo (Atlantic trout and salmon), and Cottus (sculpin). The four most sensitive genera to chronic exposures were Hyalella (amphipod), Cottus, Gammarus (amphipod), and Salvelinus. Using the updated datasets, hardness dependent criteria equations were calculated for acute and chronic exposures to cadmium. At a hardness of 50 mg/L as calcium carbonate, the criterion maximum concentration (CMC, or 'acute

  16. Discovery of Larval Gnathostoma nipponicum in Frogs and Snakes from Jeju-do (Province), Republic of Korea

    PubMed Central

    Woo, Ho-Choon; Oh, Hong-Shik; Cho, Shin-Hyeong; Na, Byoung-Kuk

    2011-01-01

    A survey was performed to find out the intermediate hosts of Gnathostoma nipponicum in Jeju-do (Province), the Republic of Korea. In August 2009 and 2010, a total of 82 tadpoles, 23 black-spotted pond frogs (Rana nigromaculata), 7 tiger keelback snakes (Rhabdophis tigrinus tigrinus), 6 red-tongue viper snakes (Agkistrodon ussuriensis), and 2 cat snakes (Elaphe dione) were collected in Jeju-do and examined by the pepsin-HCl digestion method. Total 5 gnathostome larvae were detected in 3 (50%) of 6 A. ussuriensis, 70 larvae in 3 of 7 (42.9%) R. tigrinus tigrinus, and 2 larvae in 2 of 82 (8.7%) frogs. No gnathostome larvae were detected in tadpoles and cat snakes. The larvae detected were a single species, and 2.17×0.22 mm in average size. They had characteristic head bulbs, muscular esophagus, and 4 cervical sacs. Three rows of hooklets were arranged in the head bulbs, and the number of hooklets in each row was 29, 33, and 36 posteriorly. All these characters were consistent with the advanced third-stage larvae of G. nipponicum. It has been first confirmed in Jeju-do that R. nigromaculata, A. ussuriensis, and R. tigrinus tigrinus play a role for intermediate and/or paratenic hosts for G. nipponicum. PMID:22355217

  17. Food Resources of Stream Macronivertebrates Determined by Natural-Abundance stable C and N Isotopes and a 15N Tracer Addition

    SciTech Connect

    Mulholland, P. J.

    2000-01-01

    Trophic relationships were examined using natural-abundance {sup 13}C and {sup 15}N analyses and a {sup 15}N-tracer addition experiment in Walker Branch, a 1st-order forested stream in eastern Tennessee. In the {sup 15}N-tracer addition experiment, we added {sup 15}NH{sub 4} to stream water over a 6-wk period in early spring, and measured {sup 15}N:{sup 14}N ratios in different taxa and biomass compartments over distance and time. Samples collected from a station upstream from the {sup 15}N addition provided data on natural-abundance {sup 13}C:{sup 12}C and {sup 15}N:{sup 14}N ratios. The natural-abundance {sup 15}N analysis proved to be of limited value in identifying food resources of macroinvertebrates because {sup 15}N values were not greatly different among food resources. In general, the natural-abundance stable isotope approach was most useful for determining whether epilithon or detritus were important food resources for organisms that may use both (e.g., the snail Elimia clavaeformis), and to provide corroborative evidence of food resources of taxa for which the {sup 15}N tracer results were not definitive. The {sup 15}N tracer results showed that the mayflies Stenonema spp. and Baetis spp. assimilated primarily epilithon, although Baetis appeared to assimilate a portion of the epilithon (e.g., algal cells) with more rapid N turnover than the bulk pool sampled. Although Elimia did not reach isotopic equilibrium during the tracer experiment, application of a N-turnover model to the field data suggested that it assimilated a combination of epilithon and detritus. The amphipod Gammarus minus appeared to depend mostly on fine benthic organic matter (FBOM), and the coleopteran Anchytarsus bicolor on epixylon. The caddisfly Diplectrona modesta appeared to assimilate primarily a fast N-turnover portion of the FBOM pool, and Simuliidae a fast N-turnover component of the suspended particulate organic matter pool rather than the bulk pool sampled. Together, the

  18. Limestone-based technosols: a suitable way for the remediation of sediments contaminated by heavy metals.

    NASA Astrophysics Data System (ADS)

    Martínez-Sanchez, Maria Jose; Garcia-Lorenzo, Mari Luz; Martínez, Salvadora; Gonzalez, Eva; Molina, Jose; Hernández, Carmen; Pérez-Sirvent, Carmen

    2013-04-01

    fischeri), embryogenesis assay in sea urchin (Paracentrotus lividus) and survival in estuarine amphipods (Gammarus aequicauda). The obtained results suggest that selected remediation technique reduces significantly the toxicological effect of the percolate to the tested organisms. The ecotoxicological testing may be a useful approach for assessing the toxicity as a complement to chemical analysis. In addition, the use of a battery of bioassays allows diminishing problems related to false positive results. The use of limestone filler constitutes an excellent option in sediments polluted by trace elements, because of risk for human health or ecosystems does not exist after the intervention. in addition, the designed experience allow to optimize stabilizer quantities, and may suppose a big cost-saving project in areas affected by mining activities.

  19. Characterization of the hydrology, water chemistry, and aquatic communities of selected springs in the St. Johns River Water Management District, Florida, 2004

    USGS Publications Warehouse

    Phelps, G.G.; Walsh, Stephen J.; Gerwig, Robert M.; Tate, William B.

    2006-01-01

    from the Silver Springs group and in both boils at Gemini Springs. No pesticides were detected in water samples from De Leon Spring and Green Spring. Evidence of denitrification was indicated by the presence of excess nitrogen gas in water samples from most of the springs. Aquatic communities varied among the springs. Large floating mats of cyanobacteria (blue-green algae), identified as Lyngbya wollei, were observed in De Leon Spring during all sampling events in 2004. At Gemini Springs, the dominant periphyton was Rhizoclonium sp. Of the three springs sampled for benthic invertebrates, De Leon Spring had the highest overall species richness and most disturbance intolerant species (Florida Index = 4). Green Spring had the lowest species richness of the springs sampled. Based on qualitative comparisons, overall macroinvertebrate species richness seemed to be negatively related to magnesium, potassium, sodium, and specific conductance. Invertebrate abundance was greatest when dissolved oxygen and nitrate were high but phosphorus and potassium concentrations were low. Dipteran abundance seemed to be positively associated with specific conductance and total organic carbon but negatively associated with nitrate-N. Amphipods were the numerically dominant group collected in most (six of nine) collections. Shifts in amphipod abundance of the two species collected (Gammarus sp. and Hyalella azteca) varied by season among the three springs, but there were no trends evident in the variation. Fish populations were relatively species-rich at the Silver Springs group, De Leon Spring, and Gemini Springs, but not at Green Spring. Nonindigenous fish species were observed at all springs except Green Spring.

  20. A review of the hyperiidean amphipod genus Hyperoche Bovallius, 1887 (Crustacea: Amphipoda: Hyperiidea: Hyperiidae), with the description of a new genus to accommodate H. shihi Gasca, 2005.

    PubMed

    Zeidler, Wolfgang

    2015-01-01

    This is the first comprehensive review of the genus Hyperoche since that of Bovallius (1889). This study is based primarily on the extensive collections of the ZMUC but also on more recent collections in other institutions. Seven valid species are recognised in this review, including one described as new to science. Two new characters were discovered; the first two pereonites are partially or wholly fused dorsally and the coxa of pereopod 7 is fused with the pereonite. These two new characters, combined with the knife-shaped carpus of the gnathopoda and the laminate mandibular molar, help to further distinguish this genus amongst the Hyperiidea. Partly as a result of establishing these distinctive characters, a new genus, Prohyperia gen. nov. is proposed for H. shihi Gasca, 2005 because it has characters not consistent with Hyperoche or the closely related genus Hyperia, to which it also bears some resemblance. Hyperoche medusarum and H. luetkenides, although morphologically similar, are considered separate species, with H. medusarum restricted to the colder waters of the northern Hemisphere and H. luetkenides to the Southern Ocean and Antarctic waters. Hyperoche cryptodactylus, still only known from the unique type, is considered a synonym of H. luetkenides because the character distinguishing it, the retractile dactyl of gnathopod 2, also occurs in some specimens of H. luetkenides and has also been found in other species of Hyperoche. Some specimens also have some pereopoda with partly or wholly retracted dactyls, although there is no pattern to the occurrence. In addition to the above the following species are also considered valid, H. martinezii, H. mediterranea and H. picta, found mainly in the tropical and temperate regions of the Atlantic and Pacific Oceans, and H. capucinus, restricted to the region between the Antarctic Polar Front and the Antarctic Continent. One new species, H. macrocephalus sp. nov., is described from the tropical eastern Indian Ocean and the Mediterranean Sea. All species are described and illustrated and a key is provided to facilitate their identification.  PMID:25661204

  1. Review of amphipods of the Melita group (Amphipoda: Melitidae) from the coastal waters of Sakhalin Island (Far East of Russia). III. Genera Abludomelita Karaman, 1981 and Melita Leach, 1814.

    PubMed

    Labay, Vjacheslav S

    2016-01-01

    The taxonomic analysis of Melita group is performed. The revision of the genus Melita Leach, 1814 was held on the basis of analysis of morphological characters. Cladistic analysis of morphological relationships within genera Abludomelita and Melita is performed. Status of the genus Paraniphargus Tattersall, 1925 restored. New genera Barnardomelita gen. nov. and Ledoyeromelita gen. nov. are described and removed from the composition of the genus Melita. A review of Melita group (fam. Melitidae) from the shelf of Sakhalin Island based on all literature and own data is provided. Based on new material, two new species of the genus Abludomelita Karaman, 1981 are described: A. klitinii sp. nov. and A. okhotensis sp. nov. from the shelf of Sakhalin Island. Megamoera aequidentatum Labay, 2013 is transferred to the genus Abludomelita as A. rotundactyla (Ren, 2012) on the basis of additional morphological description of male. The new subspecies Melita shimizui sakhalinensis ssp. nov. is described from estuaries of Sakhalin Island. The keys to the world species of genera Abludomelita and Melita are provided. PMID:27615866

  2. EFFECTS OF SYNTHETIC POLYELECTROLYTES ON SELECTED AQUATIC ORGANISMS

    EPA Science Inventory

    The acute toxicity of several polyelectrolytes to daphnids (Daphnia magna), fathead minnows (Pimephales promelas), gammarids (Gammarus pseudolimnaeus) and midges (Paratanytarsus parthenogeneticus) was tested. Most nonionic and anionic polyelectrolytes were not toxic at 100 mg/l w...

  3. Against the flow: chemical detection of downstream predators in running waters

    PubMed Central

    Dahl, J.; Nilsson, P. A.; Petersson, L. B.

    1998-01-01

    In running waters, chemical cues have generally been assumed to always come from upstream locations. Here, we present field and laboratory evidence that Gammarus pulex can use chemical cues from downstream predators to adaptively adjust drifting behaviour. In the field, significantly fewer Gammarus migrated into stream enclosures where brown trout (Salmo trutta) were present than into control enclosures. In a subsequent laboratory experiment, Gammarus actively avoided live trout and trout chemicals placed downstream in an artificial stream, whereas no effects were found in response to control or visual cues. We suggest that the mechanism explaining the ability of Gammarus to detect downstream predators is use of backflows, which locally transport fish chemicals against the main flow. Such backflows are both created by the Gammarus itself and by surrounding substrate heterogeneity. These results profoundly affect the way in which we view the chemical environment of running waters and have important implications for empirical and theoretical work evaluating predator effects in running waters, as they demonstrate that prey immigration rates can depend on downstream predator densities.

  4. Toxicity of silicon carbide nanowires to sediment-dwelling invertebrates in water or sediment exposures

    USGS Publications Warehouse

    Mwangi, Joseph N.; Wang, Ning; Ritts, Andrew; Kunz, James L.; Ingersoll, Christopher G.; Li, Hao; Deng, Baolin

    2011-01-01

    Silicon carbide nanowires (SiCNW) are insoluble in water. When released into an aquatic environment, SiCNW would likely accumulate in sediment. The objective of this study was to assess the toxicity of SiCNW to four freshwater sediment-dwelling organisms: amphipods (Hyalella azteca), midges (Chironomus dilutus), oligochaetes (Lumbriculus variegatus), and mussels (Lampsilis siliquoidea). Amphipods were exposed to either sonicated or nonsonicated SiCNW in water (1.0 g/L) for 48 h. Midges, mussels, and oligochaetes were exposed only to sonicated SiCNW in water for 96 h. In addition, amphipods were exposed to sonicated SiCNW in whole sediment for 10 d (44% SiCNW on dry wt basis). Mean 48-h survival of amphipods exposed to nonsonicated SiCNW in water was not significantly different from the control, whereas mean survival of amphipods exposed to sonicated SiCNW in two 48-h exposures (0 or 15% survival) was significantly different from the control (90 or 98% survival). In contrast, no effect of sonicated SiCNW was observed on survival of midges, mussels, or oligochaetes. Survival of amphipods was not significantly reduced in 10-d exposures to sonicated SiCNW either mixed in the sediment or layered on the sediment surface. However, significant reduction in amphipod biomass was observed with the SiCNW either mixed in sediment or layered on the sediment surface, and the reduction was more pronounced for SiCNW layered on the sediment. These results indicated that, under the experimental conditions, nonsonicated SiCNW in water were not acutely toxic to amphipods, sonicated SiCNW in water were acutely toxic to the amphipods, but not to other organisms tested, and sonicated SiCNW in sediment affected the growth but not the survival of amphipods.

  5. Tide-associated biological rhythms of some white sea littoral invertebrates.

    NASA Astrophysics Data System (ADS)

    Gusev, O. A.; Golubev, A. I.

    2001-01-01

    We report the results from two years of laboratory observations of the tide-associated rhythms of activity of White Sea intertidal invertebrates, Mya arenaria (Bivalvia) and Gammarus finmarchicus (Amphipoda). The tidal associated activity of these invertebrates could not be estimate as a clear circatidal clock. Gammarus activity could be phase shifted by a 0.5 h exposure to turbulent water twice a day for 2-3 days. Mya's rhythm could be changed by a single drainage of aquariums lasting about 15 min. This kind of timing system may be a relatively primitive evolution feature.

  6. Molecular data reveal complex hybridization and a cryptic species of neotropical wild cat.

    PubMed

    Trigo, Tatiane C; Schneider, Alexsandra; de Oliveira, Tadeu G; Lehugeur, Livia M; Silveira, Leandro; Freitas, Thales R O; Eizirik, Eduardo

    2013-12-16

    Hybridization among animal species has recently become more recognized as an important phenomenon, especially in the context of recent radiations. Here we show that complex hybridization has led to contrasting patterns of genomic composition among closely related species of the Neotropical cat genus Leopardus. We show strong evidence of ancient hybridization and introgression between the pampas cat (L. colocolo) and northeastern populations of tigrina (L. tigrinus), leading to remarkable cytonuclear discordance in the latter. In contrast, southern tigrina populations show recent and continuing hybridization with Geoffroy's cat (L. geoffroyi), leading to extreme levels of interspecific admixture at their contact zone. Finally, we demonstrate that two seemingly continuous Brazilian tigrina populations show no evidence of ongoing gene flow between them, leading us to support their formal recognition as distinct species, namely L. tigrinus in the northeast and L. guttulus in the south. PMID:24291091

  7. Genetic Identification of Spirometra decipiens Plerocercoids in Terrestrial Snakes from Korea and China

    PubMed Central

    Jeon, Hyeong-Kyu; Park, Hansol; Lee, Dongmin; Choe, Seongjun; Kim, Kyu-Heon; Sohn, Woon-Mok; Eom, Keeseon S.

    2016-01-01

    Human sparganosis is a zoonotic disease caused by infection with larval forms (procercoid/plerocercoid) of Spirometra spp. The purpose of this study was to identify Spirometra spp. of infected snakes using a multiplex PCR assay and phylogenetic analysis of mitochondrial DNA sequence data from the spargana of terrestrial snakes obtained from Korea and China. A total of 283 snakes were obtained that included 4 species of Colubridae comprising Rhabdophis tigrinus tigrinus (n=150), Dinodon rufozonatum rufozonatum (n=64), Elaphe davidi (n=2), and Elaphe schrenkii (n=7), and 1 species of Viperidae, Agkistrodon saxatilis (n=60). The snakes were collected from the provinces of Chungbuk, Chungnam, and Gyeongbuk in Korea (n=161), and from China (n=122). The overall infection rate with spargana was 83% (235/283). The highest was recorded for D. rufozonatum rufozonatum (100%), followed by A. saxatilis (85%) and R. tigrinus tigrinus (80%), with a negative result for E. davidi (0%) and E. schrenkii (0%). The sequence identities between the spargana from snakes (n=50) and Spirometra erinaceieuropaei (KJ599680) or S. decipiens (KJ599679) control specimens were 90.8% and 99.2%, respectively. Pairwise genetic distances between spargana (n=50) and S. decipiens ranged from 0.0080 to 0.0107, while those between spargana and S. erinaceieuropaei ranged from 0.1070 to 0.1096. In this study, all of the 904 spargana analyzed were identified as S. decipiens either by a multiplex PCR assay (n=854) or mitochondrial cox1 sequence analysis (n=50). PMID:27180576

  8. Survey of feline leukemia virus and feline coronaviruses in captive neotropical wild felids from Southern Brazil.

    PubMed

    Guimaraes, Ana M S; Brandão, Paulo E; de Moraes, Wanderlei; Cubas, Zalmir S; Santos, Leonilda C; Villarreal, Laura Y B; Robes, Rogério R; Coelho, Fabiana M; Resende, Mauricio; Santos, Renata C F; Oliveira, Rosangela C; Yamaguti, Mauricio; Marques, Lucas M; Neto, Renata L; Buzinhani, Melissa; Marques, Regina; Messick, Joanne B; Biondo, Alexander W; Timenetsky, Jorge

    2009-06-01

    A total of 57 captive neotropical felids (one Leopardus geoffroyi, 14 Leopardus pardalis, 17 Leopardus wiedii, 22 Leopardus tigrinus, and three Puma yagouaroundi) from the Itaipu Binacional Wildlife Research Center (Refúgio Bela Vista, Southern Brazil) were anesthetized for blood collection. Feces samples were available for 44 animals, including one L. geoffroyi, eight L. pardalis, 14 L. wiedii, 20 L. tigrinus, and one P. yagouaroundi. Total DNA and RNA were extracted from blood and feces, respectively, using commercial kits. Blood DNA samples were evaluated by polymerase chain reaction (PCR) for feline leukemia virus (FeLV) proviral DNA, whereas reverse transcriptase-PCR was run on fecal samples for detection of coronavirus RNA. None of the samples were positive for coronaviruses. A male L. pardalis and a female L. tigrinus were positive for FeLV proviral DNA, and identities of PCR products were confirmed by sequencing. This is the first evidence of FeLV proviral DNA in these species in Southern Brazil. PMID:19569487

  9. Seasonal variability and inter-species comparison of metal bioaccumulation in caged gammarids under urban diffuse contamination gradient: implications for biomonitoring investigations.

    PubMed

    Lebrun, Jérémie D; Geffard, Olivier; Urien, Nastassia; François, Adeline; Uher, Emmanuelle; Fechner, Lise C

    2015-04-01

    Although caging of Gammarus species offers promising lines of inquiry to monitor metal bioavailability in freshwaters, the interspecies responsiveness to metal exposures is still unclear. In addition, abiotic factors inherent to transplantation can hamper the interpretation of field bioaccumulation data. To assess the relevance of using gammarids as biomonitors, we investigated the seasonal influence on metal bioaccumulation in two common species, Gammarus pulex and Gammarus fossarum. During four seasons, caged gammarids were deployed on three sites along the Seine River exhibiting a diffuse gradient of multi-metal contamination: a site upstream and two sites downstream from the Paris megacity. For each seasonal deployment, metal concentrations in animals were determined after 7d-exposure in situ (Ag, Cd, Co, Cu, Mn, Ni, Pb and Zn). Results show that the seasonal patterns of metal contaminations are similar between both Gammarus species, and closely related to the river axis' contamination gradient. Statistical analyses indicate that bioaccumulation of essential metals in both species is influenced by season, especially by water temperature. This highlights the necessity to consider this climatic factor inherent to the deployment period for a reliable interpretation of bioaccumulation data in the field. The comparison of accumulation factors suggests that these two species coming from different geochemical origins display similar abilities to internalize metals. This generic responsiveness of caged gammarids supports their use as sentinel organisms to quantify low spatiotemporal variations in metal bioavailabilities. PMID:25577736

  10. 40 CFR 799.3300 - Unsubstituted phenylenediamines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... freshwater invertebrate Gammarus shall be conducted with o-, m-, and p-pda in accordance with § 795.120 of... section. Indications of chronicity shall be the following: for fish or aquatic invertebrates, the ratio of... accordance with § 797.1600 of this chapter. (B) An invertebrate life-cycle flow-through toxicity test...

  11. 40 CFR 799.3300 - Unsubstituted phenylenediamines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... freshwater invertebrate Gammarus shall be conducted with o-, m-, and p-pda in accordance with § 795.120 of... section. Indications of chronicity shall be the following: for fish or aquatic invertebrates, the ratio of... accordance with § 797.1600 of this chapter. (B) An invertebrate life-cycle flow-through toxicity test...

  12. 40 CFR 799.3300 - Unsubstituted phenylenediamines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... freshwater invertebrate Gammarus shall be conducted with o-, m-, and p-pda in accordance with § 795.120 of... section. Indications of chronicity shall be the following: for fish or aquatic invertebrates, the ratio of... accordance with § 797.1600 of this chapter. (B) An invertebrate life-cycle flow-through toxicity test...

  13. 40 CFR 799.3300 - Unsubstituted phenylenediamines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... freshwater invertebrate Gammarus shall be conducted with o-, m-, and p-pda in accordance with § 795.120 of... section. Indications of chronicity shall be the following: for fish or aquatic invertebrates, the ratio of... accordance with § 797.1600 of this chapter. (B) An invertebrate life-cycle flow-through toxicity test...

  14. 40 CFR 799.3300 - Unsubstituted phenylenediamines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... freshwater invertebrate Gammarus shall be conducted with o-, m-, and p-pda in accordance with § 795.120 of... section. Indications of chronicity shall be the following: for fish or aquatic invertebrates, the ratio of... accordance with § 797.1600 of this chapter. (B) An invertebrate life-cycle flow-through toxicity test...

  15. WETLAND PLANT SEEDLINGS AS INDICATORS OF NEAR-COASTAL SEDIMENT QUALITY: INTERSPECIFIC VARIATION

    EPA Science Inventory

    The toxicities of whole sediments collected from an urbanized Florida bayou-estuary were determined for the epibenthic mysid, Mysidopsis bahia, and the infaunal amphipod, Ampelisca abdita. In addition, the phytotoxicities of the same sediments were evaluated using rooted macrophy...

  16. Outer Continental Shelf environmental assessment program. Final reports of principal investigators. Volume 46

    SciTech Connect

    Not Available

    1986-07-01

    Contents include: Source, composition, and flux of organic detritus in lower Cook Inlet; Lower Cook Inlet meroplankton; Seasonal population density distribution of copepods, euphausiids, amphipods, and other holoplankton on the Kodiak Shelf.

  17. The iron-encrusted microbial community of Urothoe poseidonis (Crustacea, Amphipoda)

    NASA Astrophysics Data System (ADS)

    Gillan, David C.; Ribesse, Jérôme; de Ridder, Chantal

    2004-06-01

    A rust-coloured coating frequently covers the appendages and sternites of Urothoe poseidonis, an amphipod living in the burrow of the echinoid Echinocardium cordatum. Up to 80% of the collected amphipods were coated. In winter, coated amphipods were always more abundant than uncoated ones. In summer, uncoated specimens predominated. The aspect, location and development of the coating are similar in juveniles and adults. EDAX analyses and Prussian blue testing indicate that the rust-coloured coating contains iron oxyhydroxide minerals with trace metals and phosphorus. Scanning electron microscopy shows that the iron coating harbours bacterial filaments related to Beggiatoaceae (3 morphotypes were observed). Protozoans, possibly Peritrichia of the families Rovinjellidae or Vaginicolidae (one morphotype), were also observed on pereopods VI and VII. The formation of the iron coating and its potential role in the biology of the amphipod are discussed.

  18. ORGANIZATION AND ADAPTATION OF AQUATIC LABORATORY ECOSYSTEMS EXPOSED TO THE PESTICIDE DIELDRIN

    EPA Science Inventory

    A system of generalizations pertaining to the organization, development and persistence, adaptation, and productivity of ecological systems and their response to toxic substances was formulated. Laboratory ecosystems composed of persistent populations of guppies, amphipods, snail...

  19. COMPARATIVE TOXICITY TESTING OF SELECTED BENTHIC AND EPIBENTHIC ORGANISMS FOR THE DEVELOPMENT OF SEDIMENT QUALITY TEST PROTOCOLS

    EPA Science Inventory

    Sediment contamination has resulted in the need to develop an appropriate suite of toxicity tests to assess ecotoxicological impacts on estuarine ecosystems. Existing Environmental Protection Agency (EPA) protocols recommend a number of test organisms, including amphipods, polych...

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

    EPA Science Inventory

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

  1. INTERACTIONS OF CHLORPYRIFOS AND METHYL MERCURY: A MECHANISTIC APPROACH TO ASSESS CHEMICAL MIXTURES

    EPA Science Inventory

    The mechanism of interaction between chlorpyrifos, an organophosphate insecticide, and methyl mercury was assessed utilizing the amphipod, Hyalella azteca. Previous studies have demonstrated that chlorpyrifos and methl mercury interact additively with survival as the endpoint. I...

  2. PHOTOACTIVATION AND TOXICITY OF MIXTURES OF POLYCYCLIC AROMATIC HYDROCARBON COMPOUNDS IN MARINE SEDIMENT

    EPA Science Inventory

    The direct toxicity and photoinduced toxicity of sediment-associated acenaphthene, phenanthrene, fluoranthene, and pyrene were determined for the marine amphipod Rhepoxynius abronius. The four polycyclic aromatic hydrocarbons (PAHs) were spiked into sediment in a concentration se...

  3. Anuran tadpoles learn to recognize injury cues from members of the same prey guild.

    PubMed

    Pueta, Mariana; Perotti, Maria Gabriela

    2016-07-01

    Recognition of predation risk from cues released from injured heterospecific could be beneficial when prey belongs to the same prey guild. Here, we performed three experiments. Experiment 1 showed that P. thaul tadpoles reduced their activity levels when exposed to conspecific injury cues, but not when exposed to amphipod injury cues. Experiment 2 tested whether P. thaul tadpoles can learn to recognize predation risk from chemical cues released from injured heterospecifics from the same prey guild (amphipod, Hyalella patagonica). A group of tadpoles were conditioned by exposing them to a specific concentration of amphipod injury cues paired with conspecific injury cues. Two days later, we evaluated changes in the activity of tadpoles when they were exposed to amphipod cues. As a control of learning, we used an unpaired group. Additionally, we used more control groups to fully investigate the learning mechanism. Our results showed that tadpoles can learn to recognize predation risk from injured amphipods and that the mechanism underlying the observed learned response could be associative. Experiment 3 replicated Experiment 2 and also showed that a low concentration of amphipod cues did not sustain that learning. PMID:26968427

  4. Chemical defense of an Asian snake reflects local availability of toxic prey and hatchling diet

    PubMed Central

    Hutchinson, D A; Savitzky, A H; Burghardt, G M; Nguyen, C; Meinwald, J; Schroeder, F C; Mori, A

    2013-01-01

    Species that sequester toxins from prey for their own defense against predators may exhibit population-level variation in their chemical arsenal that reflects the availability of chemically defended prey in their habitat. Rhabdophis tigrinus is an Asian snake that possesses defensive glands in the skin of its neck (‘nuchal glands’), which typically contain toxic bufadienolide steroids that the snakes sequester from consumed toads. In this study, we compared the chemistry of the nuchal gland fluid of R. tigrinus from toad-rich and toad-free islands in Japan and determined the effect of diet on the nuchal gland constituents. Our findings demonstrate that captive-hatched juveniles from toad-rich Ishima Island that had not been fed toads possess defensive bufadienolides in their nuchal glands, presumably due to maternal provisioning of these sequestered compounds. Wild-caught juveniles from Ishima possess large quantities of bufadienolides, which could result from a combination of maternal provisioning and sequestration of these defensive compounds from consumed toads. Interestingly, juvenile females from Ishima possess larger quantities of bufadienolides than do juvenile males, whereas a small sample of field-collected snakes suggests that adult males contain larger quantities of bufadienolides than do adult females. Captive-born hatchlings from Kinkasan Island lack bufadienolides in their nuchal glands, reflecting the absence of toads on that island, but they can sequester bufadienolides by feeding on toads (Bufo japonicus) in captivity. The presence of large quantities of bufadienolides in the nuchal glands of R. tigrinus from Ishima may reduce the risk of predation by providing an effective chemical defense, whereas snakes on Kinkasan may experience increased predation due to the lack of defensive compounds in their nuchal glands. PMID:23853424

  5. Cytotoxicity of some edible mushrooms extracts over liver hepatocellular carcinoma cells in conjunction with their antioxidant and antibacterial properties

    PubMed Central

    Sadi, Gökhan; Emsen, Buğrahan; Kaya, Abdullah; Kocabaş, Aytaç; Çınar, Seval; Kartal, Deniz İrtem

    2015-01-01

    Background: Mushrooms have been valued for their nutritive content and as traditional medicines; several important medicinal properties of mushrooms have been recognized worldwide. Objective: The purpose of this study was to elucidate the cell growth inhibitory potential of four edible mushrooms; Coprinus comatus (O.F. Mull.) Pers. (Agaricaceae), Tricholoma fracticum (Britzelm.) Kreisel (Tricholomataceae), Rhizopogon luteolus Fr. and Nordholm (Rhizopogonaceae), Lentinus tigrinus (Bull.) Fr. (Polyporaceae) on hepatocellular carcinoma (HepG2) cells in conjunction with their antioxidant and antibacterial capacities. Materials and Methods: Five different extracts of edible mushrooms were obtained using water, methanol, acetone, n-hexane and chloroform as solvent systems for cytotoxic, antioxidant and antibacterial properties. Results: C. comatus showed substantial in vitro cytotoxic activity against HepG2 cell lines with all extracts especially with chloroform 50% inhibition (IC50 value of 0.086 mg/ml) and acetone (IC50 value of 0.420 mg/ml). Chloroform extract of C. comatus had maximum amount of β-carotene (25.94 μg/mg), total phenolic content (76.32 μg/mg) and lycopene (12.00 μg/mg), and n-hexane extract of L. tigrinus had maximum amount of flavonoid (3.67 μg/mg). While chloroform extract of C. comatus showed the highest 2, 2-diphenyl-1-picrylhydrazyl (DPPH) capturing activity (1.579 mg/ml), the best result for metal chelating activity was obtained from methanolic extract (0.842 mg/ml). Moreover, all tested mushrooms demonstrated antibacterial activity and n-hexane extract of L. tigrinus and acetone extracts of T. fracticum were the most active against tested microorganism. Conclusion: These results indicate that different extracts of investigated mushroom have considerable cytotoxic, antioxidant and antibacterial properties and may be utilized as a promising source of therapeutics. PMID:26109775

  6. A new genus and species of Delphacini (Hemiptera: Fulgoroidea: Delphacidae) from Argentina.

    PubMed

    de Remes Lenicov, A M Marino; Varela, G

    2014-01-01

    A new genus of Delphacini is described from Argentina, Pyrophagus Remes Lenicov gen. n., with one new species, P. tigrinus Remes Lenicov & Varela sp. n. The new species, distributing over a wide cultivated area of Northwestern and Central Argentina and recently confirmed as a vector of MRCV (Rio Cuarto maize virus) in experimental conditions, is one of the most frequently found delphacid species on wheat, oat, maize, triticale, rye, barley and wild Gramineae. The main diagnostic features of the new genus and species are described and illustrated, and information on the host plants, geographical distribution and vector capacity of the new species is provided.  PMID:25283401

  7. Molecular detection of Cytauxzoon spp. in asymptomatic Brazilian wild captive felids.

    PubMed

    André, Marcos R; Adania, Cristina H; Machado, Rosangela Z; Allegretti, Silmara M; Felippe, Paulo A N; Silva, Ketty F; Nakaghi, Andréa C H; Dagnone, Ana S

    2009-01-01

    Cytauxzoon spp. DNA was detected for the first time in blood samples from asymptomatic Brazilian wild captive felids. In 2006, 72 EDTA blood samples from seven wild felids species: Puma concolor (puma), Leopardus pardalis (ocelot), Puma yagouaroundi (jaguarundi), Leopardus wiedii (margay), Leopardus tigrinus (little spotted cat), Oncifelis colocolo (pampas cat) and Panthera onca (jaguar) were analyzed using polymerase chain reaction to amplify the 18S rRNA gene segment in order to verify the presence of Cytauxzoon spp. DNA. Nine samples were positive: six ocelots, two pumas, and one jaguar. In Brazil, wild felids may be natural reservoirs for Cytauxzoon spp. PMID:19204356

  8. The role of melanism in oncillas on the temporal segregation of nocturnal activity.

    PubMed

    Graipel, M E; Oliveira-Santos, L G R; Goulart, F V B; Tortato, M A; Miller, P R M; Cáceres, N C

    2014-08-01

    The occurrence of coat colour polymorphisms in populations may promote the ecological success of species by permitting a wider spectrum of use of different subsets of available resources. We conducted an analysis of temporal segregation by comparing night brightness with nocturnal activity of spotted and melanistic oncillas (Leopardus tigrinus). Melanistic oncillas were more active during bright nights and spotted oncillas and other species were more active during dark nights. Each colour morph occupied a temporal niche outside the confidence interval of the other colour morph, demonstrating the ecological significance of polymorphic colour patterns in this felid species. PMID:25627377

  9. The cryptofauna of Zostera marina (L.): Abundance, biomass and population dynamics

    NASA Astrophysics Data System (ADS)

    Pihl Baden, Susanne

    Cryptofauna (epifauna passing a 2-mm but retained on a 0.2-mm mesh sieve) of Zostera marina on the Swedish west coast (58°N, 11°E) is dominated by crustaceans, mainly detritivorous tube-building amphipods and harpacticoids. Abundance and biomass of amphipods in two relatively unpolluted Z. marina beds were higher than any data from the literature, with maximum abundance of 80·10 3 ind·m -2 and 1 g AFDW·m -2 bottom. This is at least partly due to the small mesh size used in this investigation. The recruitment of the crustaceans started in late June and was continuous through the rest of the season, whereas the recruitment of the molluscs peaked in late June and July. In a Z. marina bed (Rixö) located 2 km from an oil refinery, the seasonal abundance of amphipods was 15% of the abundance in the other beds, whereas the remaining fauna had about the same density. In Rixö the percentage of female amphipod with empty brood pouches increased during the season. It is suggested that low abundances and fecundity of amphipods in Rixö could result from oil pollution.

  10. Getting What Is Served? Feeding Ecology Influencing Parasite-Host Interactions in Invasive Round Goby Neogobius melanostomus

    PubMed Central

    Emde, Sebastian; Kochmann, Judith; Kuhn, Thomas; Plath, Martin; Klimpel, Sven

    2014-01-01

    Freshwater ecosystems are increasingly impacted by alien invasive species which have the potential to alter various ecological interactions like predator-prey and host-parasite relationships. Here, we simultaneously examined predator-prey interactions and parasitization patterns of the highly invasive round goby (Neogobius melanostomus) in the rivers Rhine and Main in Germany. A total of 350 N. melanostomus were sampled between June and October 2011. Gut content analysis revealed a broad prey spectrum, partly reflecting temporal and local differences in prey availability. For the major food type (amphipods), species compositions were determined. Amphipod fauna consisted entirely of non-native species and was dominated by Dikerogammarus villosus in the Main and Echinogammarus trichiatus in the Rhine. However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus. Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main. To analyse infection pathways, we examined 17,356 amphipods and found Pomphorhynchus sp. larvae only in D. villosus in the river Rhine at a prevalence of 0.15%. Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes) may influence host-parasite dynamics of N. melanostomus in its introduced range. PMID:25338158

  11. Relative sensitivity of five benthic invertebrate species to reference toxicants and resin-acid contaminated sediments

    SciTech Connect

    Hickey, C.W.; Martin, M.L.

    1995-08-01

    Five sediment-dwelling native New Zealand freshwater invertebrate species (amphipod, Chaetocorophium c.f. lucasi; clam, Sphaerium novaezelandiae; oligochaete, Lumbriculus variegatus; tanaid, Tanais standfordi; and the burrowing mayfly, Ichthybotus hudsoni) were assessed for their suitability for sediment toxicity testing by comparison of sensitivity to reference toxicants [phenol and pentachlorophenol (PCP)] and contaminated sediments. The 96-h EC50 values at 20 C showed a greater range in test sensitivity for phenol (30-fold range) from the most sensitive test, amphipod (8.1 mg/L), to the least sensitive one, clam (243 mg/L), compared with PCP (14-fold range), with amphipod the most sensitive test species (0.13 mg/L) and tanaid the least sensitive (1.8 mg/L). Clam reburial was a more sensitive end point than was lethality for phenol (by 20-fold) and PCP (by 2.4-fold). Four of the test species, excluding the tanaid, showed good 10-d survival in reference muds ({ge}87%) but lower survival in sand sediments ({ge}79%). Bleached kraft mill sediment containing high resin-acid concentrations (total 1,900 mg/kg dry weight) showed significant reductions in amphipod survival (15%), clam reburial (30%), and oligochaete survival (17%), and reproduction (49%). Amphipods, clams, and oligochaetes were the most promising species for sublethal test development.

  12. IMPACTS OF MESOGRAZERS ON EPIPHYTE AND ENDOPHYTE GROWTH ASSOCIATED WITH CHEMICALLY DEFENDED MACROALGE FROM THE WESTERN ANTARCTIC PENINSULA: A MESOCOSM EXPERIMENT(1).

    PubMed

    Aumack, Craig F; Amsler, Charles D; McClintock, James B; Baker, Bill J

    2011-02-01

    It has been hypothesized that the extensive mesograzer community along the western Antarctic Peninsula regulates epiphytic algae as well as emergent filaments from endophytic species. Should grazing limit growth of fouling or potentially pathogenic microphytes, then Antarctic macrophytes may actually benefit from the remarkably high densities of mesograzer amphipods that occur in these waters. Although initially counterintuitive, the negative impacts of epi/endophyte fouling may outweigh stresses caused by limited amphipod grazing on chemically defended macrophytes by reducing stress from endo/epiphyte biomass. If so, then alleviating mesograzing stress should result in significant increases in endo/epiphytic biomass. To test this hypothesis, a mesocosm experiment was conducted. Individuals representing four common species of Antarctic macroalgae were placed in flow-through seawater mesocosms. Amphipods were added to five mesocosms at simulated natural densities, while the other five remained herbivore free. At the end of 7 weeks, endo/epiphytic growth on individual macrophytes was quantified. Most species of macroalgae demonstrated noticeably higher instances of endophyte coverage, epiphytic diversity, and diatom colonization in consumer-free mesocosms than in the presence of amphipods. These data suggest that macroalgae along the western Antarctic Peninsula rely on grazers to control populations of potentially harmful epiphytes. We hypothesize that the chemically defended macroalgal flora lives in mutualism with high densities of mesograzers, providing amphipods with shelter from predation while continually being cleaned of potentially harmful endo/epiphytes. PMID:27021708

  13. Macrofaunal involvement in the sublittoral decay of kelp debris: the detritivore community and species interactions

    NASA Astrophysics Data System (ADS)

    Bedford, A. P.; Moore, P. G.

    1984-01-01

    The fauna associated with sea-bed accumulations of decomposing Laminaria saccharina has been studied by year-round SCUBA diving at two sites in the Clyde Sea area. Seasonal changes in density of 64 species are reported. In the autumn, large quantities of kelp are detached by storms. This weed carries with it to the sea bed a large part of its normal fauna. Additional species settle onto the weed from the plankton whilst others migrate onto it from the surrounding sea bed. Peak densities of associated species were recorded in autumn. Litter bag experiments in situ showed that, except during the summer, weed is lost from sea-bed accumulations at a faster rate when macrofaunal animals are excluded. The macrofauna therefore inhibits decomposition. The relative importance of interactive cropping by three macrodetritivores, Psammechinus miliaris (Echinodermata), Platynereis dumerilii (Polychaeta) and Gammarus locusta (Amphipoda) was studied by in situ containment of different species combinations. The presence of Gammarus with Psammechinus resulted in less weed being lost than when Psammechinus was isolated. This is because Gammarus selectively crops rotting weed, retarding frond disintegration by microbes. Platynereis retards microbial colonization of frond tissues ruptured during its feeding by repeated cropping of the same region. Weed would decompose very rapidly were it not for macrofaunal cropping. Macroalgal decay thus differs profoundly from that of vascular plants.

  14. [Diversity and faunal analysis of crustaceans in Potatso National Park, Shangri-La, China].

    PubMed

    Shu, Shu-Sen; Chen, Fei-Zhou; Yang, Jun-Xing; Yang, Xiao-Jun; Chen, Xiao-Yong

    2013-06-01

    Potatso National Park was the first national park in mainland China, preceded by the earlier Bitahai Nature Reserve. Located in the northwest of Yunnan and on the southeast of Qinghai-Tibet plateau, Potatso is a typical low latitude and high elevation wetland nature reserve, with large areas of coniferous forest around alpine lakes and both wetland and water area ecosystems. In August, 2011, we undertook a survey of crustaceans in the park, sampling lakes, ponds, streams, and rivers throughout Potatso. We found a total of 29 species (including varieties) belonging to 24 genera and 11 families. Notable discoveries include Parartemiopsis sp, Arctodiaptomus parvispinus and Simocephalus congener, which are the first examples of these species to be recorded in China. Likewise, Gammarus bitaensis is a unique crustacean found only in Potatso National Park and Thermocyclops dumonti and Gammarus paucispinus are both endemic species to northwestern Yunnan. The overall faunal characteristics of crustaceans in the park also revealed several things about Potatso: (1) Cosmopolitan and Palaearctic elements reach 48.27% and 37.93%, clearly showing the Palaearctic element as the dominant fauna; (2) most of the crustacean, such as Arctodiaptomus parvispinus and Gammarus, are typical alpine types, confirming that Potatso has feature typical of alpine and plateau fauna; and (3) the proportion of endemic and rare crustacean species in Potatso National Park is approximately 10%, suggesting that the Potatso National Park in particular and the northwest of Yunnan in general have a unique geological and evolutionary history. PMID:23775996

  15. Tandem mass spectrometry of herbicide residues in lipid-rich tissue.

    PubMed

    Headley, J V; Peru, K M; Arts, M T

    1995-12-01

    A tandem mass spectrometry procedure, originally developed for bacterial biofilms was adapted for the identification of herbicide residues in lipid-rich tissue of amphipods collected from microcosms in a prairie wetland. For this application, the amounts of tissue employed (less than 1 mg wet weight), and detection of target analytes at picogram levels, were similar to the values reported for bacterial biofilms. Described is an application of the technique for the identification of residues of the herbicide S-2,3,3-trichloroallyl diisopropyl thiocarbamate (triallate; trade name Avadex-BW). For amphipods collected from microcosms exposed to the herbicide 2-[4-(2,4-dichlorophenoxy)phenoxy]propionic acid methyl ester (diclofop-methyl, trade name Hoe Grass), there were detectable levels of only the hydrolysis product, diclofop acid, in the lipid-rich tissue. Other transformation products reported for bacterial biofilms were not observed in the amphipods. PMID:8633778

  16. An evaluation of the toxicity of contaminated sediments from Waukegan Harbor, Illinois, following remediation

    USGS Publications Warehouse

    Kemble, N.E.; Hardesty, D.G.; Ingersoll, C.G.; Johnson, B.T.; Dwyer, F.J.; MacDonald, D.D.

    2000-01-01

    Waukegan Harbor in Illinois was designated as a Great Lakes Area of Concern due to high concentrations of sediment-associated polychlorinated biphenyls (PCBs). The objective of this study was to evaluate the toxicity of 20 sediment samples collected after remediation (primarily dredging) of Waukegan Harbor for PCBs. A 42-day whole sediment toxicity test with the amphipod Hyalella azteca (28-day sediment exposure followed by a 14-day reproductive phase) and sediment toxicity tests with Microtox?? were conducted to evaluate sediments from Waukegan Harbor. Endpoints measured were survival, growth, and reproduction (amphipods) and luminescent light emission (bacteria). Survival of amphipods was significantly reduced in 6 of the 20 sediment samples relative to the control. Growth of amphipods (either length or weight) was significantly reduced relative to the control in all samples. However, reproduction of amphipods identified only two samples as toxic relative to the control. The Microtox basic test, conducted with organic extracts of sediments identified only one site as toxic. In contrast, the Microtox solid-phase test identified about 50% of the samples as toxic. A significant negative correlation was observed between reproduction and the concentration of three polynuclear aromatic hydrocarbons (PAHs) normalized to total organic carbon. Sediment chemistry and toxicity data were evaluated using sediment quality guidelines (consensus-based probable effect concentrations, PECs). Results of these analyses indicate that sediment samples from Waukegan Harbor were toxic to H. azteca contaminated at similar Contaminant concentrations as sediment samples that were toxic to H. azteca from other areas of the United States. The relationship between PECs and the observed toxicity was not as strong for the Microtox test. The results of this study indicate that the first phase of sediment remediation in Waukegan Harbor successfully lowered concentrations of PCBs at the site

  17. Ocean acidification induces changes in algal palatability and herbivore feeding behavior and performance.

    PubMed

    Duarte, Cristian; López, Jorge; Benítez, Samanta; Manríquez, Patricio H; Navarro, Jorge M; Bonta, Cesar C; Torres, Rodrigo; Quijón, Pedro

    2016-02-01

    The effects of global stressors on a species may be mediated by the stressors' impact on coexisting taxa. For instance, herbivore-algae interactions may change due to alterations in algal nutritional quality resulting from high CO2 levels associated with ocean acidification (OA). We approached this issue by assessing the indirect effects of OA on the trophic interactions between the amphipod Orchestoidea tuberculata and the brown alga Durvillaea antarctica, two prominent species of the South-east Pacific coast. We predicted that amphipod feeding behavior and performance (growth rate) will be affected by changes in the palatability of the algae exposed to high levels (1000 ppm) of CO2. We exposed algae to current and predicted (OA) atmospheric CO2 levels and then measured their nutritive quality and amphipod preference in choice trials. We also assessed consumption rates separately in no-choice trials, and measured amphipod absorption efficiency and growth rates. Protein and organic contents of the algae decreased in acidified conditions and amphipods showed low preference for these algae. However, in the no-choice trials we recorded higher grazing rates on algae exposed to OA. Although amphipod absorption efficiency was lower on these algae, growth rates did not differ between treatments, which suggests the occurrence of compensatory feeding. Our results suggest that changes in algal nutritional value in response to OA induce changes in algal palatability and these in turn affect consumers' food preference and performance. Indirect effects of global stressors like OA can be equally or more important than the direct effects predicted in the literature. PMID:26453521

  18. A new species of the subterranean genus Stygobromus (Amphipoda: Crangonyctidae) from a cave spring in northern Florida, USA.

    PubMed

    Holsinger, John R; Sawicki, Thomas R

    2016-01-01

    A relatively large, distinct new species of the subterranean amphipod crustacean genus Stygobromus (Amphipoda: Crangonyctidae) measuring 13 mm in length is described from Skipper Spring, a cave spring in the northwestern "panhandle" of Florida, USA. This is the first species of the genus described from the state of Florida where it is described from only 3 females. A fourth much smaller specimen of this species was collected from nearby Miller's Crossing Spring on Holmes Creek. All other stygomorphic amphipod species recorded from the state of Florida have been in the genus Crangonyx. PMID:27395865

  19. Side-scan sonar assessment of gray whale feeding in the Bering Sea

    USGS Publications Warehouse

    Johnson, K.R.; Nelson, C.H.

    1984-01-01

    Side-scan sonar was used to map and measure feeding pits of the California gray whale over 22,000 square kilometers of the northeastern Bering Sea floor. The distribution of pits, feeding whales, ampeliscid amphipods (whale prey), and a fine-sand substrate bearing the amphipods were all closely correlated. The central Chirikov Basin and nearshore areas of Saint Lawrence Island supply at least 6.5 percent of the total gray whale food resource in summer. While feeding, the whales resuspend at least 1.2 x 108 cubic meters of sediment annually; this significantly affects the geology and biology of the region.

  20. Neutralizing antibodies against feline herpesvirus type 1 in captive wild felids of Brazil.

    PubMed

    Ruthner Batista, Helena Beatriz de Carvalho; Kindlein Vicentini, Franco; Franco, Ana Cláudia; Rosado Spilki, Fernando; Ramos Silva, Jean Carlos; Adania, Cristina Harumi; Roehe, Paulo Michel

    2005-09-01

    Feline herpesvirus type 1 infection affects domestic cats, causing mainly upper respiratory tract diseases. Although this infection has been described in captive and free-ranging wild felids from Europe, Asia, North America, and Africa, no information is available on its occurrence among wild felids of Brazil. In this study, 250 serum samples of six species of Brazilian captive wild felids (Leopardus tigrinus, Leopardus wiedii, Herpailurus yaguarondi, Puma concolor, Leopardus pardalis, and Panthera onca) were examined for neutralizing antibodies to feline herpesvirus type 1. Positive sera were found in 72% of L. tigrinus samples, 15% of L. wiedii, 6% of L. pardalis, 8% of H. yaguarondi, 18% of P. concolor, and 14% of P. onca. The relatively low percentages of seropositivity and low antibody titers found among the last five species suggest that feline herpesvirus type 1 does not circulate extensively among these animals. Nevertheless, quarantine, serologic screening, and vaccination of newly introduced felids is recommended in zoos in order to prevent virus transmission and outbreaks of the disease among wild felids kept in captivity. PMID:17312763

  1. Active foraging for toxic prey during gestation in a snake with maternal provisioning of sequestered chemical defences.

    PubMed

    Kojima, Yosuke; Mori, Akira

    2015-01-01

    Many animals sequester dietary defensive compounds and incorporate them into the offspring, which protects the young against predation. One possible but poorly investigated question is whether females of such species actively prey upon toxic diets. The snake Rhabdophis tigrinus sequesters defensive steroids from toads consumed as prey; it also feeds on other amphibians. Females produce chemically armed offspring in direct proportion to their own level of toad-derived toxins by provisioning the toxins to their eggs. Our field observations of movements and stomach contents of radio-tracked R. tigrinus showed that gravid snakes preyed upon toads by actively foraging in the habitat of toads, even though toads were a scarce resource and toad-searching may incur potential costs. Our Y-maze experiments demonstrated that gravid females were more likely to trail the chemical cues of toads than were males or non-gravid females. These results showed behavioural switching in females and active foraging for scarce, toxic prey during gestation. Because exploitation of toads by gravid females results in their offspring being more richly endowed with prey-derived toxins, active foraging for toxic prey is expected to be an adaptive antipredator trait, which may enhance chemical defence in offspring. PMID:25392472

  2. [Genetic polymorphism of blood protein of six Passeriformes species in Zhalong National Nature Reserve].

    PubMed

    Xu, Xing-Jun; Lü, Jian-Wei; Xuan, Li-Fang; Zhang, Dong-Yue; Zhou, Shuang-Tao; Zhao, Kan; Wang, Bin; Shao, Shu-Li

    2009-06-01

    The polymorphism of hemoglobin (Hb), serum albumin (Alb), trandferring (Tf) and adenosin deaminase (Ada) in the blood of Emberiza elegans, Phylloscopus inornatus, E. aureola, Lanius tigrinus, Passer montanus, and E. spodocephala in Zhalong National Nature Reserve were studied by SDS-polyacrylamide-gel electrophoresis. All the protein loci of the six Passeriformes species exhibited polymorphism, and Ada locus had a relatively high heterozygosity. The analysis of average heterozygosity demonstrated that P. inornatus had a higher population genetic variance, while E. spodocephala was relatively stable. The six species could be classified into two clusters. E. elegans, E. aureola, E. spodocephala and P. inornatus were clustered into one group, while P. montanus and L. tigrinus were clustered into another group. This clustering was consistent with the actual taxonomic status of the six species. The higher thermoregulation index and predation pressure of the study area did not lead to the substantial variation of hereditary constitution of the six species, possibly due to the gene intercommunion between the six species and the outside of the study area, which decreased the variance and differentiation of the population genetics of the six species. PMID:19795660

  3. Hemoplasmas in wild canids and felids in Brazil.

    PubMed

    André, Marcos Rogerio; Adania, Cristina Harumi; Allegretti, Silmara Marques; Machado, Rosangela Zacarias

    2011-06-01

    Hemotropic mycoplasmas, epicellular erythrocytic bacterial parasites lacking a cell wall, are the causative agents of infectious anemia in numerous mammalian species. The presence of hemotropic mycoplasmas in blood samples of neotropical and exotic wild canids and felids from Brazilian zoos were recorded using molecular techniques. Blood samples were collected from 146 Brazilian wild felids, 19 exotic felids, 3 European wolves (Canis lupus), and from 97 Brazilian wild canids from zoos in the Brazilian states of São Paulo and Mato Grosso and the Federal District. Using conventional polymerase chain reaction (PCR), this work found 22 (13%) wild felids positive to Candidatus Mycoplasma haemominutum [4 jaguars (Panthera onca); 3 pumas (Puma concolor); 10 ocelots (Leopardus pardalis); 2 jaguarondis (Puma yagouaroundi); and 3 little spotted cats (Leopardus tigrinus)]. Only one little spotted cat (Leopardus tigrinus) was positive to Mycoplasma haemofelis, and none was positive to Candidatus Mycoplasma turicensis. Two bush dogs (Speothos venaticus) were positive for a Mycoplasma sp. closely related to Candidatus Mycoplasma haematoparvum, and two European wolves were positive for a Mycoplasma sp. closely related to Candidatus Mycoplasma haemominutum. This is the first study regarding the molecular detection of hemotropic mycoplasmas in wild canids. PMID:22946419

  4. Active foraging for toxic prey during gestation in a snake with maternal provisioning of sequestered chemical defences

    PubMed Central

    Kojima, Yosuke; Mori, Akira

    2015-01-01

    Many animals sequester dietary defensive compounds and incorporate them into the offspring, which protects the young against predation. One possible but poorly investigated question is whether females of such species actively prey upon toxic diets. The snake Rhabdophis tigrinus sequesters defensive steroids from toads consumed as prey; it also feeds on other amphibians. Females produce chemically armed offspring in direct proportion to their own level of toad-derived toxins by provisioning the toxins to their eggs. Our field observations of movements and stomach contents of radio-tracked R. tigrinus showed that gravid snakes preyed upon toads by actively foraging in the habitat of toads, even though toads were a scarce resource and toad-searching may incur potential costs. Our Y-maze experiments demonstrated that gravid females were more likely to trail the chemical cues of toads than were males or non-gravid females. These results showed behavioural switching in females and active foraging for scarce, toxic prey during gestation. Because exploitation of toads by gravid females results in their offspring being more richly endowed with prey-derived toxins, active foraging for toxic prey is expected to be an adaptive antipredator trait, which may enhance chemical defence in offspring. PMID:25392472

  5. Regional Models for Sediment Toxicity Assessment

    EPA Science Inventory

    This paper investigates the use of empirical models to predict the toxicity of sediment samples within a region to laboratory test organisms based on sediment chemistry. In earlier work, we used a large nationwide database of matching sediment chemistry and marine amphipod sedim...

  6. SHORT-EXPOSURE, SUBLETHAL, SEDIMENT TOXICITY TEST USING THE MARINE BIVALVE MULINIA LATERALIS: STATISTICAL DESIGN AND COMPARATIVE SENSITIVITY

    EPA Science Inventory

    Over the last 10 years a great deal of research effort has concentrated on determining the effects of contaminated sediments on aquatic organisms. or marine systems, this effort has emphasized acute sediment toxicity tests using amphipods, although a variety of other end points a...

  7. Molecular phylogeny of Niphargus boskovici (Crustacea: Amphipoda) reveals a new species from epikarst.

    PubMed

    Švara, Vid; Delić, Teo; Rađa, Tonći; Fišer, Cene

    2015-01-01

    We describe a new species of an amphipod Niphargus zagorae sp. n. and redescribe its nearest relative and morphologically similar species N. boskovici S. Karaman, 1952. We present the geographic distributions of both species, morphological diagnoses and infer their phylogenetic position within the genus based on COI, 28S and H3 markers. PMID:26250278

  8. Regional assessment of marine and estuarine sediment toxicity in Southern California, USA.

    PubMed

    Greenstein, Darrin; Bay, Steven; Jacobe, Matthew; Barton, Carlita; Sakamoto, Ken; Young, Diana; Ritter, Kerry; Schiff, Ken

    2013-02-01

    Sediment toxicity was investigated at 222 stations in the Southern California Bight (SCB) during 2008. This represented the first time that assessment methods established by California's new Sediment Quality Objectives program were employed in a survey of this scale. The goal was to determine the extent and magnitude of sediment toxicity in the SCB, how toxicity compared among specific environments, and whether toxicity has changed over the last decade. Two toxicity tests were used: the 10-day amphipod whole sediment survival test with Eohaustorius estuarius and a 48-h embryo development test with the mussel Mytilus galloprovincialis exposed at the sediment-water interface. Less than 1 % of the area of the SCB was found to be toxic to the amphipod test. No toxicity was found in offshore stations, but 14 % of embayment areas were toxic to the amphipods. The mussel test identified 13 % of the embayment areas to be toxic. Estuary and marina locations had the greatest areal extent of toxicity for both tests. The two toxicity methods agreed that sediments were not toxic at over half of the stations tested. The mussel test showed a greater magnitude of response than the amphipod. Sediment toxicity was shown to have declined in both extent and magnitude from levels measured in 1998 and 2003. PMID:22638724

  9. 76 FR 9297 - Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-17

    ... invertebrates (74 FR 10701). On June 22, 2010, we published a proposed rule revising critical habitat for the... habitat for the four invertebrates (75 FR 35375). We are restating the PCEs for Noel's amphipod here, as... listing rule (70 FR 46304, August 9, 2005), threats to the four invertebrates include reducing...

  10. 78 FR 63100 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Comal Springs...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... FR 25679), allowing the public to provide comments on our analysis. We have incorporated the comments..., and Peck's cave amphipod as endangered species on December 18, 1997 (62 FR 66295). We designated critical habitat for these three species on July 17, 2007 (72 FR 39248). On October 19, 2012 (77 FR...

  11. Optimizing the performance of Hyalella azteca in chronic toxicity tests: Results of feeding studies with various foods and feeding regimes

    EPA Science Inventory

    The freshwater amphipod Hyalella azteca is a common organism used for sediment toxicity testing in the United States and elsewhere. Standard methods for 10-d and 42-d toxicity tests with H. azteca were last revised and published by USEPA/ASTM in 2000. Under the methods in the man...

  12. INTERLABORATORY STUDY OF PRECISION: HYALELLA AZTECA AND CHIRONOMUS TENTANS FRESHWATER SEDIMENT TOXICITY ASSAYS

    EPA Science Inventory

    Standard 10-d whole sediment toxicity test methods have recently been developed by the U.S. Environmental Protection Agency (EPA) for the amphipod Hyalella azteca and the midge Chironomus tentans. An interlaboratory evaluation of method precision was performed using a group of se...

  13. Uptake, Accumulation and Excretion by Corophium volutator(Crustacea: Amphipoda) of Zinc, Cadmium and Cobalt Added to Sewage Sludge

    NASA Astrophysics Data System (ADS)

    Burgos, M. Galay; Rainbow, P. S.

    1998-11-01

    Zinc, cadmium and cobalt associated with digested sewage sludge are available to the benthic deposit-feeding amphipodCorophium volutator(Pallas). Accumulation by the amphipod of radioactively labelled metals adsorbed onto a 5% sludge-sediment mixture increased with time of exposure up to 15 days, but irregularly so as pulses of labelled metal were excreted into faecal pellets. The three labelled metals were accumulated and excreted apparently almost synchronously by individual amphipods, although great variability between different individuals was found. This intraspecific variability could not be attributed to differences between male and female amphipods. Net accumulation of labelled metals from the sludge increased with increased labelled metal concentration in the sludge, but not with time beyond an initial period of 15-30 days. It is proposed that the metal excretion patterns might reflect the breakdown of epithelial cells of the ventral caeca following a cell cycle, releasing accumulated stores of detoxified metals into the gut lumen and out of the body through faeces.

  14. TOXICITY OF FENVALERATE AND PERMETHRIN TO SEVERAL NONTARGET AQUATIC INVERTEBRATES

    EPA Science Inventory

    Selected species of stoneflies, caddisflies, mayflies, dipterans, amphipods, and snails were exposed, in the laboratory, to fenvalerate or permethrin in a flowing-water test system for upto 28 days. Both behavior and death were monitored during the exposure. The LC50 values decre...

  15. Use of vegetated agricultural drainage ditches to decrease pesticide transport from tomato and alfalfa fields in California: runoff toxicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was performed to investigate the potential of vegetated drainage ditches for mitigating the impact of agricultural irrigation runoff on downstream aquatic ecosystems. Water column toxicity to larval fathead minnow (Pimephales promelas), and the amphipod, Hyalella azteca, was measured for ...

  16. USE OF ULVA LACTUTA TO IDENTIFY AMMONIA TOXICITY IN MARINE AND ESTUARINE SEDIMENTS

    EPA Science Inventory

    Toxicity identification evaluation(TIE) methods are being developed for use with whole sediments. Although a phase I TIE method has been developed to characterize ammonia toxicity in aqueous samples using the marine macroalga Ulva lactuca, the relationship between amphipod and my...

  17. SENSITIVITY DIFFERENCE AMONG VARIOUS STRAINS OF HYALLELA AZTECA

    EPA Science Inventory

    The North American amphipod Hyalella azteca is widely used in toxicity testing. H. azteca has a broad geographic distribution, and genetic evidence suggests that populations diverged from each other long ago. The importance of this genetic divergence to toxicity testing is uncle...

  18. DIFFERENCES IN STRESSOR SENSITIVITY IN GEOGRAPHICALLY DISTINCT POPULATIONS OF AMPELISCA ABDITA

    EPA Science Inventory

    Risk assessment methods for contaminated sediments typically rely upon data derived from laboratory studies in which effects on individuals from a reference environment are the primary measure. The objective of this study was to determine if amphipods endemic to a contaminated si...

  19. Ecological impacts of lead mining on Ozark streams: Toxicity of sediment and pore water

    USGS Publications Warehouse

    Besser, J.M.; Brumbaugh, W.G.; Allert, A.L.; Poulton, B.C.; Schmitt, C.J.; Ingersoll, C.G.

    2009-01-01

    We studied the toxicity of sediments downstream of lead-zinc mining areas in southeast Missouri, using chronic sediment toxicity tests with the amphipod, Hyalella azteca, and pore-water toxicity tests with the daphnid, Ceriodaphnia dubia. Tests conducted in 2002 documented reduced survival of amphipods in stream sediments collected near mining areas and reduced survival and reproduction of daphnids in most pore waters tested. Additional amphipod tests conducted in 2004 documented significant toxic effects of sediments from three streams downstream of mining areas: Strother Creek, West Fork Black River, and Bee Fork. Greatest toxicity occurred in sediments from a 6-km reach of upper Strother Creek, but significant toxic effects occurred in sediments collected at least 14 km downstream of mining in all three watersheds. Toxic effects were significantly correlated with metal concentrations (nickel, zinc, cadmium, and lead) in sediments and pore waters and were generally consistent with predictions of metal toxicity risks based on sediment quality guidelines, although ammonia and manganese may also have contributed to toxicity at a few sites. Responses of amphipods in sediment toxicity tests were significantly correlated with characteristics of benthic invertebrate communities in study streams. These results indicate that toxicity of metals associated with sediments contributes to adverse ecological effects in streams draining the Viburnum Trend mining district.

  20. 78 FR 25679 - Endangered and Threatened Wildlife and Plants; Proposed Revision of Critical Habitat for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-02

    ... Springs riffle beetle, and Peck's cave amphipod (77 FR 64272). We proposed to designate approximately 39.4... rule. DATES: The comment period for the proposed rule published October October 19, 2012, at 77 FR 77 FR 64272, is reopened. Written Comments: We will consider comments received or postmarked on...

  1. Partitioning mechanisms of predator interference in different habitats.

    PubMed

    Griffen, Blaine D; Byers, James E

    2006-01-01

    Prey are often consumed by multiple predator species. Predation rates on shared prey species measured in isolation often do not combine additively due to interference or facilitation among the predator species. Furthermore, the strength of predator interactions and resulting prey mortality may change with habitat type. We experimentally examined predation on amphipods in rock and algal habitats by two species of intertidal crabs, Hemigrapsus sanguineus (top predators) and Carcinus maenas (intermediate predators). Algae provided a safer habitat for amphipods when they were exposed to only a single predator species. When both predator species were present, mortality of amphipods was less than additive in both habitats. However, amphipod mortality was reduced more in rock than algal habitat because intermediate predators were less protected in rock habitat and were increasingly targeted by omnivorous top predators. We found that prey mortality in general was reduced by (1) altered foraging behavior of intermediate predators in the presence of top predators, (2) top predators switching to foraging on intermediate predators rather than shared prey, and (3) density reduction of intermediate predators. The relative importance of these three mechanisms was the same in both habitats; however, the magnitude of each was greater in rock habitat. Our study demonstrates that the strength of specific mechanisms of interference between top and intermediate predators can be quantified but cautions that these results may be habitat specific. PMID:16086166

  2. SEDIMENT TOXICITY ASSESSMENT: COMPARISON OF STANDARD AND NEW TESTING DESIGNS

    EPA Science Inventory

    Standard methods of sediment toxicity testing are fairly well accepted; however, as with all else, evolution of these methods is inevitable. We compared a standard ASTM 10-day amphipod toxicity testing method with smaller, 48- and 96-h test methods using very toxic and reference ...

  3. Effects of pollution on freshwater invertebrates

    SciTech Connect

    Buikema

    1982-06-01

    The biological effects of acid rain, chlorination, heavy metals and other forms of pollution on freshwater invertebrates are examined in this review. Several methods for evaluating chronic toxicity to pesticide residues and synthetic fuels components are reviewed. The effects of pollutants is reviewed in detail for cladocera, amphipods, isopods, decapods, aquatic insects, molluscs, worms, and protozoa.(KRM)

  4. Modifying Foods and Feeding Regimes to Optimize the Performance of Hyalella azteca during Chronic Toxicity Tests

    EPA Science Inventory

    The amphipod Hyalella azteca is commonly used to assess the toxicity of sediments and waters. However, laboratories have reported varying success in maintaining healthy cultures and in obtaining consistent growth and reproduction (where applicable), especially during tests...

  5. Inter-lab testing of Hyalella azteca water and sediment methods: 1 background and overview of the 42-d survival, growth and reproduction test

    EPA Science Inventory

    Over the past four years, USEPA-Duluth, USGS-Columbia, the Illinois Natural History Survey, and Environment Canada have been conducting studies to refine the USEPA and ASTM International methods for conducting 10- to 42-d water or sediment toxicity exposures with the amphipod Hya...

  6. Inter-lab testing of Hyalella azteca water and sediment methods: 4 Results from 10- to 42-d tests conducted with sediment substrates

    EPA Science Inventory

    Over the past four years, USEPA Duluth, USGS Columbia, the Illinois Natural History Survey, and Environment Canada have been conducting studies to refine the USEPA and ASTM International methods for conducting 10- to 42-d water or sediment toxicity exposures with the amphipod Hya...

  7. A TOXICITY ASSESSMENT APPROACH TO EVALUATING IN-SITU BIOREMEDIATION OF PAH CONTAMINATED SEDIMENTS

    EPA Science Inventory

    Freshwater and marine sediment toxicity tests were used to measure baseline toxicity of sediment samples collected from New Jersey/New York Harbor (NJ/NY) (non-PAH- contaminated) sediment (ERC). Four freshwater toxicity tests were used: 1) amphipod (Hyalella azteca) mortality and...

  8. 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...

  9. Inter-lab testing of Hyalella azteca water and sediment methods: 1 Summary of 10- to 42-d data from 25 laboratories

    EPA Science Inventory

    Over the past four years, USEPA Duluth, USGS Columbia, the Illinois Natural History Survey, and Environment Canada have been conducting studies to refine the USEPA and ASTM International methods for conducting 10- to 42-d water or sediment toxicity exposures with the amphipod Hya...

  10. The Status of Benthos in Lake Ontario

    EPA Science Inventory

    The benthic community of Lake Ontario was dominated by an amphipod (Diporeia spp.) prior to the 1990’s. Two dreissenid mussel species D. polymorpha (zebra) and D. bugensis (quagga) were introduced in 1989 and 1991 via ballast water exchange. D. bugensis was observed as deep as 85...

  11. SYNTHETIC-BASED DRILLING FLUIDS: AN ASSESSMENT OF THE SPATIAL DISTRIBUTION OF TOXICANTS IN SEDIMENTS FROM GULF OF MEXICO DRILLING PLATFORMS

    EPA Science Inventory

    Use of the amphipods, Leptocheirus plumulosus and Ampelisca abdita, in these bioassays presented no major difficulties in the execution of these test protocols. Sensitivity to the toxicants was exhibited by L. plumulosus and survival of control animals was good suggesting the sui...

  12. Commensal Leucothoidae (Crustacea, Amphipoda) of the Ryukyu Archipelago, Japan. Part II: sponge-dwellers

    PubMed Central

    White, Kristine N.; Reimer, James Davis

    2012-01-01

    Abstract Commensal leucothoid amphipods have been collected from the canals of their sponge hosts throughout the Ryukyu Archipelago, Japan. Eleven new species are described in the genus Leucothoe with valuable location data and host records. An identification key to sponge-dwelling Leucothoidae of the Ryukyu Archipelago is provided. PMID:22328858

  13. Consumption and feeding preference of Echinogammarus marinus on two different algae: Fucus vesiculosus and Ulva intestinalis

    NASA Astrophysics Data System (ADS)

    Martins, Irene; Leite, Nuno; Constantino, Emanuel

    2014-01-01

    Echinogammarus marinus constitutes the most abundant amphipod species in Fucus spp. assemblages from many North Atlantic estuaries. However, there are some doubts about the real use of fucoids by the amphipod. Whilst some studies report the ingestion of Fucus vesiculosus by E. marinus, others suggest that the amphipod preference for fucoids is mostly related to sheltering rather than feeding, due to the high phlorotannin content of brown algae. The purpose of the present work was to disentangle this issue by checking the consumption rate and feeding preference of E. marinus on F. vesiculosus, its preferential habitat, and on Ulva intestinalis, a green algae abundant in the Mondego estuary (Western Coast of Portugal) and usually considered as highly palatable for herbivores. In a 2-stage laboratorial setup, fresh disks of the two types of algae were offered to E. marinus for three days. Consumption rates were estimated from differences between algal and animal initial and final fresh weights using a control correction factor, while preference was tested by differences in algal consumption rates when no choice was offered (stage 1) and when the two algae were offered simultaneously (stage 2). Results showed that E. marinus effectively consumed fresh F. vesiculosus in much higher amounts than U. intestinalis and significantly preferred to consume F. vesiculosus over U. intestinalis. Therefore, feeding habits must be one of the factors related to the close association of the amphipod with F. vesiculosus, although other factors may also be involved (e.g. sheltering).

  14. Impact of Marine Submergence and Season on Faunal Colonization and Decomposition of Pig Carcasses in the Salish Sea.

    PubMed

    Anderson, Gail S; Bell, Lynne S

    2016-01-01

    Pig carcasses, as human proxies, were placed on the seabed at a depth of 300 m, in the Strait of Georgia and observed continuously by a remotely operated camera and instruments. Two carcasses were deployed in spring and two in fall utilizing Ocean Network Canada's Victoria Experimental Network under the Sea (formerly VENUS) observatory. A trial experiment showed that bluntnose sixgill sharks could rapidly devour a carcass so a platform was designed which held two matched carcasses, one fully exposed, the other covered in a barred cage to protect it from sharks, while still allowing invertebrates and smaller vertebrates access. The carcasses were deployed under a frame which supported a video camera, and instruments which recorded oxygen, temperature, salinity, density, pressure, conductivity, sound speed and turbidity at per minute intervals. The spring exposed carcass was briefly fed upon by sharks, but they were inefficient feeders and lost interest after a few bites. Immediately after deployment, all carcasses, in both spring and fall, were very rapidly covered in vast numbers of lyssianassid amphipods. These skeletonized the carcasses by Day 3 in fall and Day 4 in spring. A dramatic, very localized drop in dissolved oxygen levels occurred in fall, exactly coinciding with the presence of the amphipods. Oxygen levels returned to normal once the amphipods dispersed. Either the physical presence of the amphipods or the sudden draw down of oxygen during their tenure, excluded other fauna. The amphipods fed from the inside out, removing the skin last. After the amphipods had receded, other fauna colonized such as spot shrimp and a few Dungeness crabs but by this time, all soft tissue had been removed. The amphipod activity caused major bioturbation in the local area and possible oxygen depletion. The spring deployment carcasses became covered in silt and a black film formed on them and on the silt above them whereas the fall bones remained uncovered and hence

  15. Impact of Marine Submergence and Season on Faunal Colonization and Decomposition of Pig Carcasses in the Salish Sea

    PubMed Central

    Anderson, Gail S.; Bell, Lynne S.

    2016-01-01

    Pig carcasses, as human proxies, were placed on the seabed at a depth of 300 m, in the Strait of Georgia and observed continuously by a remotely operated camera and instruments. Two carcasses were deployed in spring and two in fall utilizing Ocean Network Canada’s Victoria Experimental Network under the Sea (formerly VENUS) observatory. A trial experiment showed that bluntnose sixgill sharks could rapidly devour a carcass so a platform was designed which held two matched carcasses, one fully exposed, the other covered in a barred cage to protect it from sharks, while still allowing invertebrates and smaller vertebrates access. The carcasses were deployed under a frame which supported a video camera, and instruments which recorded oxygen, temperature, salinity, density, pressure, conductivity, sound speed and turbidity at per minute intervals. The spring exposed carcass was briefly fed upon by sharks, but they were inefficient feeders and lost interest after a few bites. Immediately after deployment, all carcasses, in both spring and fall, were very rapidly covered in vast numbers of lyssianassid amphipods. These skeletonized the carcasses by Day 3 in fall and Day 4 in spring. A dramatic, very localized drop in dissolved oxygen levels occurred in fall, exactly coinciding with the presence of the amphipods. Oxygen levels returned to normal once the amphipods dispersed. Either the physical presence of the amphipods or the sudden draw down of oxygen during their tenure, excluded other fauna. The amphipods fed from the inside out, removing the skin last. After the amphipods had receded, other fauna colonized such as spot shrimp and a few Dungeness crabs but by this time, all soft tissue had been removed. The amphipod activity caused major bioturbation in the local area and possible oxygen depletion. The spring deployment carcasses became covered in silt and a black film formed on them and on the silt above them whereas the fall bones remained uncovered and hence

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

    SciTech Connect

    Rice, C.A.; Plesha, P.D.; Casillas, E.; Misitano, D.A.; Meador, J.P.

    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. 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.

  17. Variable feeding behavior in Orchestoidea tuberculata (Nicolet 1849): Exploring the relative importance of macroalgal traits

    NASA Astrophysics Data System (ADS)

    Duarte, Cristian; Acuña, Karin; Navarro, Jorge M.; Gómez, Iván; Jaramillo, Eduardo; Quijón, Pedro

    2014-03-01

    The feeding behavior of algal consumers inhabiting sandy beaches and the consequences of this behavior on their performance are poorly understood. Food quality has been shown to influence the food preference of algal consumers. However, food preference can often be altered or subordinated to habitat choice. This study analyzes the feeding behavior (preference and consumption rate), absorption efficiency and growth rates of the talitrid amphipod Orchestoidea tuberculata (Nicolet, 1849) in relation to the nutritional characteristics of two of the most common macroalgae stranded in the Chilean north-central region. Our experiments show that these amphipods prefer Macrocystis integrifolia over Lessonia nigrescens when presented with fresh fragments of both algae simultaneously. However, this preference did not match the performance of the amphipods when reared on diets of a single algal species: in that growth rates were not different. These results suggest that M. integrifolia is not a superior food item compared to L. nigrescens. The lower content of proteins and total organic matter found in M. integrifolia supports this interpretation. The preference of the amphipods for L. nigrescens over M. integrifolia when dry powdered algae of each species were provided (artificial food), suggested that some aspect of the physical structure of these two algae determined food preference. When the amphipods were maintained with each of the algal species in no choice experiments, they consumed 2 times more M. integrifolia, but showed higher absorption efficiency on L. nigrescens. These results suggest that food quantity and not absorption efficiency was used to compensate for the lower nutritional quality of M. integrifolia. The feeding behavior documented in this study differs significantly from that observed in populations of the same species inhabiting southern Chile, cautioning against generalizing results obtained even within a single species. Our results suggest that

  18. Toxicity testing of freshwater sediment collected near freshwater aquaculture facilities in the Maritimes, Canada.

    PubMed

    Lalonde, B A; Garron, C; Ernst, B; Jackman, P

    2013-01-01

    In the Atlantic region of Canada, there are close to 50 land-based freshwater aquaculture facilities, most of which discharge wastewater to freshwater receiving environments. This study was designed to assess the chemical and toxicological characteristics of sediments in those receiving environments. Thirty sediment samples were collected from 3 locations (upstream, outfall and downstream) at seven freshwater aquaculture facilities. Toxicity tests conducted included amphipod growth, amphipod survival and Microtox™. Sediments were also analysed for ammonia/porewater ammonia, redox and sulphide. Porewater ammonia concentration for the amphipod survival test ranged from 0.01 to 42 mg/L at the conclusion of the 14-day survival test. Ammonia concentration in sediment ranged from 0.3-202 μg/g, sulphide concentration ranged from 0.15 to 17.4 μg/g, yet redox ranged from 32 to 594 mV. Microtox™  IC50 values ranged from 108,00 to >164,000 mg/L, yet amphipod survival ranged from 0 to 100%, depending on sampling locations. Amphipod survival was significantly related (P < 0.05) to porewater ammonia (at time = 0 and 14 days) and Microtox™  IC50 was significantly related (P < 0.05) to ammonia, sulphide and redox levels. These results indicate that discharges from some the land-based aquaculture facilities are impacting sediment dwelling benthic invertebrates at the outfall but that impact largely disappears by 100 m downstream. Furthermore those impacts were rarely detected during the early winter season, when biomass production was at the lowest. PMID:23705607

  19. Functional characterization of the oxidative capacity of mitochondria and glycolytic assessment in benthic aquatic organisms.

    PubMed

    Atlante, A; Basset, A; Bobba, A; Lassandro, R; Mastrototaro, F; Vignes, F

    2016-06-01

    The metabolism of benthic aquatic invertebrates, populating transitional water ecosystems, is influenced by both physiological and environmental factors, thus involving an adjustment of physiological processes which has a metabolic cost. In order to discover changes in metabolic pathways in response to specific factors, it's firstly necessary characterizing the principal cellular metabolic activities of the small benthic aquatic organisms. We approach here the bioenergetic state issue of two benthic organisms, i.e. Lekanesphaera monodi and Gammarus insensibilis, evidencing that no apparent and statistically significative differences between them in aerobic as well in glycolytic capacities are detected, except for COX activity. PMID:26847717

  20. Gnathostomiasis in frog-eating snakes from Japan.

    PubMed

    Ishiwata, K; Nakao, H; Nose, R; Komiya, M; Hanada, S; Enomoto, Y; Nawa, Y

    1997-10-01

    Gnathostoma doloresi parasitizes the gastric wall of wild (boars) and domestic (pigs) swine (Sus scrofa). Its larvae cause cutaneous larva migrans in humans. Amphibians, reptiles and a freshwater fish are infected with the advanced 3rd stage larvae. Prevalence of G. doloresi larvae were surveyed in several snakes, especially in a common frog-eating snake (Rhabdophis tigrinus). All species of snakes examined were infected with G. doloresi larvae suggesting that snakes are important reservoir hosts. Prevalence of G. doloresi larvae in frog-eating snakes was lower than that found in mammal-eating snakes. Thus, as a source of infection to snakes, small mammals may be more important than frogs in the natural life cycle of G. doloresi in Japan. PMID:9391975

  1. The first report of Hepatozoon sp. (Apicomplexa: Hepatozoidae) in neotropical felids from Brazil.

    PubMed

    Metzger, Betina; dos Santos Paduan, Karina; Rubini, Adriano Stefani; de Oliveira, Tadeu Gomes; Pereira, Cristiane; O'Dwyer, Lucia Helena

    2008-03-25

    In order to investigate the occurrence of Hepatozoon infection in Neotropical felids from Brazil, blood from the jugular or cephalic vein was taken from 29 non-domestic felids including ocelot (Leopardus pardalis), little spotted cat (Leopardus tigrinus), margay (Leopardus wiedii), and jaguarondi (Puma yagouaroundi) from the Northeast region of Brazil. Hepatozoon infection was confirmed by light microscopy and molecular techniques. The results showed five naturally infected felids. Partial sequences of the 18S rRNA gene of the Hepatozoon sp. from these felids were further analyzed. Sequences revealed that the isolates found are closely related to Hepatozoon sp. from domestic cats in Spain. Hepatozoon species from Neotropical felids were identified molecularly and characterized for the first time. This is also the first report of Hepatozoon infection in a little spotted cat. PMID:18243562

  2. First evidence of feline herpesvirus, calicivirus, parvovirus, and Ehrlichia exposure in Brazilian free-ranging felids.

    PubMed

    Filoni, Claudia; Catão-Dias, José Luiz; Bay, Gert; Durigon, Edison Luiz; Jorge, Rodrigo Silva Pinto; Lutz, Hans; Hofmann-Lehmann, Regina

    2006-04-01

    Serum samples from 18 pumas (Puma concolor), one ocelot (Leopardus pardalis), and two little spotted cats (Leopardus tigrinus) collected from free-ranging animals in Brazil between 1998 and 2004 were tested by indirect immunofluorescence (IFA) for antibodies to feline herpesvirus 1 (FHV 1), calicivirus (FCV), coronavirus (FCoV), parvo-virus (FPV), Ehrlichia canis, Anaplasma pha-gocytophilum, and Bartonella henselae. Serum samples also were tested, by Western blot and ELISA, for feline leukemia virus (FeLV) specific antibodies and antigen, respectively, by Western blot for antibodies to feline immunodeficiency virus (FIV), and by indirect ELISA for antibodies to puma lentivirus (PLV). Antibodies to FHV 1, FCV, FCoV, FPV, FeLV, FIV, PLV or related viruses, and to B. henselae were detected. Furthermore, high-titered antibodies to E. canis or a closely related agent were detected in a puma for the first time. PMID:16870878

  3. A new species of Near-shore Marine Goby (Pisces: Gobiidae: Nesogobius) from Kangaroo Island, Australia.

    PubMed

    Hammer, Michael P; Hoese, Douglass F; Bertozzi, Terry

    2015-01-01

    Nesogobius is one of two goby genera with all species wholly restricted to temperate Australian waters. Described here is a new member of the genus discovered during near-shore marine and estuarine fish sampling along the central southern Australian coastline. The tiger sandgoby Nesogobius tigrinus sp. nov. is distinguished from other congeners by a combination of colouration including four prominent vertical black bars on males; morphological characters involving body scales (large), head scales (naked), body depth (slender) and gill opening (wide); meristic counts including a lack of second dorsal and anal fin spines; and mitochondrial DNA sequence divergence. The species appears to be a narrow range endemic, restricted to specific sub-tidal habitat in the unique sheltered embayments of northeast Kangaroo Island. This study forms part of ongoing investigations to more fully describe the biodiversity and conservation requirements of the regional ichthyofauna. PMID:26701487

  4. Regional diversity of amphipoda in the Caribbean Sea.

    PubMed

    Martín, Alberto; Díaz, Yusbelly; Miloslavich, Patricia; Escobar-Briones, Elva; Guerra-García, José Manuel; Ortiz, Manuel; Valencia, Bellineth; Giraldo, Alan; Klein, Eduardo

    2013-12-01

    The order Amphipoda is one of the most diverse within Peracarids, and comprises 6950 described marine species. Amphipod research in the Caribbean Sea began in the late 1800s, but has increased significantly since 1980. In this study, we analized the amphipod biodiversity (Caprellidea, Gammaridea, Hyperiidea, and Ingolfiellidea) of the Caribbean Sea. For this, we compiled available data on species diversity of marine amphipods (data bases: WoRMS and OBIS and published species lists) into a comprehensive taxonomic list by country for the ecoregions of the Caribbean. Additionally, we analized the relative contribution of each country to regional diversity and the rate of discovery of new species. The Caribbean amphipod fauna is composed of 535 species within 236 genera and 73 families for the higher taxon. The Western Caribbean ecoregion holds the largest diversity (282 species), while the Eastern Caribbean recorded the lowest one (73). Mexico and Venezuela recorded the largest number of species with 266 and 206, respectively. Twelve countries had less than 50 species. The richest suborder is the Gammaridea with 381 species followed by the suborder Hyperiidea with 116. From the total of 535 amphipod species reported for the Caribbean region, 218 have the Caribbean as the holotype locality, and 132 are endemic (about 25% of the total). Areas of higher diversity seem to be concentrated along the Mexican Caribbean, Cuba and the Northern coast of South America (Venezuela-Colombia); however, such pattern is most likely reflecting local collection efforts and taxonomic expertise rather than actual distribution. Knowledge of amphipod species is mostly limited to shallow, near-shore waters, with little infonnation available on the deep sea fauna. Regional research priorities for this group should be focused on completing shallow water coastal inventories of species in Central America and the Greater and Lesser Antilles. In addition, sampling the deep sea ecosystems should

  5. Benthic response to water quality and biotic pressures in lower south San Francisco Bay, Alviso Slough, and Coyote Creek

    USGS Publications Warehouse

    Parchaso, Francis; Thompson, Janet K.; Crauder, Jeff S.; Anduaga, Rosa I.; Pearson, Sarah A.

    2015-01-01

    Bivalve biomass is elevated in summer and fall relative to the spring and winter except in Artesian Slough, where bivalves did not establish a signifcant presence. Presence of certain species contributes to the prey value of the community to predators. Potamocorbula amurensis is a shallow-burrowing bivalve and hence is easy prey for bottom-feeding predators. In contrast, Macoma petalum is a deposit feeder and can burrow deeper into the substrate than Potamocorbula amurensis, making it harder to be preyed upon. The quantitative importance of such predator-prey relationships on phytoplankton dynamics requires further investigation. There were also more amphipods in the sloughs in March 2014; this group is another potential contributor to the benthic-pelagic biomass balance. There is no observed reason for Artesian Slough to have low bivalve biomass values and high amphipod abundances. 

  6. Effects of the Exxon Valdez oil spill on eelgrass communities in Prince William Sound, Alaska 1990-1995. Restoration project 95106. Exxon Valdez oil spill restoration project final report

    SciTech Connect

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

    1997-05-01

    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 of 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.

  7. Several benthic species can be used interchangeably in integrated sediment quality assessment.

    PubMed

    Rodríguez-Romero, A; Khosrovyan, A; Del Valls, T A; Obispo, R; Serrano, F; Conradi, M; Riba, I

    2013-06-01

    The selection of the best management option for contaminated sediments requires the biological assessment of sediment quality using bioindicator organisms. There have been comparisons of the performance of different test species when exposed to naturally occurring sediments. However, more research is needed to determine their suitability to be used interchangeably. The sensitivity of two amphipod species (Ampelisca brevicornis and Corophium volutator) to sediments collected from four different commercial ports in Spain was tested. For comparison the lugworm, Arenicola marina, which is typically used for bioaccumulation testing, was also tested. Chemical analyses of the sediments were also conducted. All species responded consistently to the chemical exposure tests, although the amphipods, as expected, were more sensitive than the lugworm. It was found that C. volutator showed higher vulnerability than A.brevicornis. It was concluded that the three species can be used interchangeably in the battery of tests for integrated sediment quality assessment. PMID:23531332

  8. Comparison of bioassays for assessing sediment toxicity in Puget Sound. (Appendices included). Report for 1988-1989 (Final)

    SciTech Connect

    Pastorok, R.A.; Becker, D.S.

    1989-05-01

    This study evaluated the relative performance of several bioassays used to assess toxicity of Puget Sound sediments. Selected bioassays were conducted simultaneously on the same array of sediment samples, and direct comparisons were made among the various tests in relation to specific performance criteria. The bioassays and toxicity endpoints evaluated included the following: Amphipod test (Rhepoxynius abronius), percent mortality and abnormality; Amphipod test (Eohaustorius estuarius), percent mortality and abnormality; Juvenile geoduck (Panope generosa), percent mortality; Juvenile polychaete (Neanthes arenaceodentata), percent mortality and percent reduced biomass; Echinoderm embryo test (Dendraster excentricus), percent developmental abnormality and chromosomal abnormality; Bivalve larvae test (Mytilus edulis, Crassostera gigas), percent abnormal development; Microtox saline and organic extract (Photobacterium phosphoreum), percent decrease in luminescence. The 11 evaluation criteria included: dose responsiveness, sensitivity, statistical power, cost-effectiveness, ecological relevance, ease of use, availability of test organisms, endpoint reliability, relationship to indigenous biota, holding constraints, and stage of protocol development.

  9. Potential changes in feeding behavior of Antarctic fish, Pseudotrematomus bernacchii (Boulenger, 1902) on the East Ongul Island, Antarctica

    NASA Astrophysics Data System (ADS)

    Chavanich, Suchana; Viyakarn, Voranop; Nomura, Daiki; Watanabe, Kentaro

    2015-12-01

    The feeding habits of the Antarctic fish Pseudotrematomus bernacchii (Previous name: Trematomus bernacchii) under the fast ice around Japanese Syowa Station were investigated in the summers of 2004/2005 and 2009/2010. The results showed that amphipods and krill were the major prey. However, there was a significant difference in the proportions of larger invertebrates such as squids, octopus and other crustaceans found in the fish stomachs between 2009/2010 and the previous years. Moreover, the percentage of amphipods and krill in fish stomachs declined over the 5-year period in all fish size classes. Several factors including sea ice melting, habitat and environmental changes might have influenced the pattern of feeding behavior.

  10. Halomonhystera parasitica n. sp. (Nematoda: Monhysteridae), a parasite of Talorchestia brito (Crustacea: Talitridae) in Portugal.

    PubMed

    Poinar, George; Duarte, Daniella; Santos, Maria João

    2010-01-01

    Halomonhystera parasitica n. sp. (Monhysterida: Monhysteridae) is described from the body-cavity and under the dorsal plates of the sandy beach amphipod Talorchestia brito Stebbing (Crustacea: Talitridae) in Portugal. The new species differs from previously described members of the genus by a combination of the following characters: four medium-sized cephalic setae; base of stoma with three blunt denticles; posterior dilated portion of stoma absent; amphids small, with width less than quarter of corresponding body width; amphids located less than two labial widths from anterior extremity; uterine eggs elliptical and unembryonated; gubernaculum lacks caudal process; and male tail with two separated pairs of postcloacal papillae and a single subterminal seta-like papilla. This is the first representative of the family Monhysteridae parasitic in the body-cavity of crustaceans. Approximately 48% of the amphipods examined contained various stages of H. parasitica. PMID:20012518

  11. Spatial patterns in suprabenthic communities in the English Channel

    NASA Astrophysics Data System (ADS)

    Dauvin, Jean-Claude; Rolet, Céline; Alizier, Sandrine; Ruellet, Thierry

    2011-01-01

    The purpose of this paper was to establish the main characteristics of the suprabenthic communities of the English Channel including those found in a potential aggregate extraction zone located in the central part. Sampling was carried out with a Macer-GIROQ sledge during four periods in 2007. In this offshore site, the suprabenthic faunal composition and abundance were close to those observed in other similar sites in coarse sand to pebbles in the western and eastern parts of the English Channel. But, the species richness was low (65 species). Amphipods were the dominant group in terms of diversity and abundance. Only a few species, mostly amphipods and decapods, showed significant daily migration. Seasonal variations were moderate. Due to the similar suprabenthic fauna having good swimming ability, the aggregate extraction zone in the central part of the Channel could be rapidly colonized after exploitation and thus could rapidly insure a feeding resource for fish, which are attracted by abundant prey.

  12. Suprabenthic biodiversity of Catalan beaches (NW Mediterranean)

    NASA Astrophysics Data System (ADS)

    Munilla, T.; San Vicente, C.

    2005-03-01

    An analysis of the suprabenthos has been carried out on 13 diverse type beaches in Catalonian coast (NE of Spain). A total of 29 717 specimens, belonging to 145 species and eight different zoological groups (mysids, amphipods, cumaceans, isopods, tanaidaceans, decapods, pycnogonids, and teleostean fishes) were obtained. The suprabenthos of Catalan beaches were characterized by a mean density of 40 ind. m -2, by the abundance of Mysids (75% of the total density) and by the higher diversity of Amphipods (64 species). Five population species were considered as typical of suprabenthic assemblages: Schistomysis assimilis, Mesopodopsis slabberi, Atylus guttatus, Pontocrates altamarinus, and Cumopsis goodsir. Four main types of beaches with different number of suprabenthic species and densities and three main faunistic groups are described and related to environmental physical factors of the analysed beaches (morphodynamics, exposure, etc.). The macrofaunal trend about to that the species richness decrease from dissipative to reflective beaches is confirmed for the suprabenthic communities.

  13. [An example of anthropogeneous succession in the ecosystem of the Verkhnetulomsky Water Reservoir (the Tuloma River Basin, the Kola region)].

    PubMed

    Mitenev, V K; Shul'man, B S; Karasev, A B; Ponomarev, S V

    2010-01-01

    The destruction of initial biocenoses in the ecosystem of the Verkhnetulomsky Water Reservoir caused deep succession processes. As a result of the loss of the amphipod group in the benthos, replacement of the trophic links in fishes took place in the biocenosis of the reservoir. Benthos feeders changed over to the feeding on zooplankton and, as a result, became the constituent of the predators'diet. The structure of parasitic systems has changed. The parasites using amphipods as intermediate hosts have been and, on the contrary, the abundance of parasites infesting fishes through feeding of the latter on zooplankton has increased. Among the parasites, Triaenophorus crassus Forel became the cause of the appearance of stable triaenophorosis focus. PMID:21061595

  14. Assessment the short-term effects of wrack removal on supralittoral arthropods using the M-BACI design on Atlantic sandy beaches of Brazil and Spain.

    PubMed

    Vieira, Jenyffer Vierheller; Ruiz-Delgado, Ma Carmen; Reyes-Martínez, Ma José; Borzone, Carlos Alberto; Asenjo, Angélico; Sánchez-Moyano, Juan Emilio; García-García, Francisco José

    2016-08-01

    Wrack removal has been adopted indiscriminately, with no previous assessment of the ecological implications for sandy beach ecosystem. This study evaluated, through an M-BACI design, the effect of wrack removal on supralittoral arthropods on Atlantic sandy beaches receiving different types of wrack: mangrove propagules (Brazil), seagrasses and macroalgae (Spain). Impacted plots were contrasted with controls in 8 successive periods before and after experimental wrack removal. After the disturbance, drastic decreases in the densities of the amphipod Platorchestia monodi, coleopterans Cleridae, Nitidulidae and Phaleria testacea (Brazilian beaches) and amphipod Talitrus saltator (Spanish beaches) were detected in the impacted plots. The recovery patterns of arthropods might be related to wrack features (amount, composition, and degradation) combined with density and species-specific strategies (e.g. mobility, feeding preferences) in each Atlantic region. The temporary suppression of wrack and its associated fauna can have potential effects on the wrack-derived process and food-web structure on sandy beaches. PMID:27344395

  15. Toxicity of oiled sediments treated with bioremediation agents: A shoreline experiment in Delaware, USA

    SciTech Connect

    Mearna, A.; Doe, K.; Fisher, W.; Lee, K.; Mueller, C.

    1995-12-31