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

2016-03-01

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.

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

Metal accumulation by an epigean and a hypogean freshwater amphipod: Considerations for water quality assessment

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

Pienet, S.

1999-12-01

To evaluate their potential as biomonitors of surface and underground water quality, the accumulation of essential metals, zinc and copper, by two species of amphipod crustaceans, Gammarus fossarum (an epigean amphipod) and Niphargus rhenorhodanensis (a similar but blind and hypogean form) was investigated. These two species were exposed, under controlled laboratory conditions, to different metal concentrations for 12 days. Several concentrations of each of the two metals separately and one concentration of a mixture of both were tested. Percent mortality revealed that the hypogean species was more resistant than the epigean. During the 12 days of experiment, accumulation patterns differedmore » between species and between metals. G. fossarum, but not N. rhenorhodanensis, accumulated zinc at exposures of up to 12 days and concentrations as great as 1,000 {micro}g/L. Zinc levels in tissue of G. fossarum were greater than in those of N. rhenorhodanensis. Epigean and hypogean amphipods did not clearly accumulate copper in exposures as great at 65 {micro}g/L. Possible reasons for the differences in zinc and copper accumulation between the two species are discussed. Finally, the suitability of the two species as biomonitors for surface and underground water is discussed.« less

[Decline of Gammarus lacustris Sars (Crustacea: Amphipoda) population in the delta of the Selenga River].

PubMed

Matafonov, D V; Bazova, N V

2014-01-01

We determined the amphipod population characteristics from the water bodies of the delta of the Selenga River, where Gammarus lacustris Sars, 1863 was industrially harvested until the 1990s. In 2011, the population density of G. lacustris varied from 80 to 10 200 in Lapkhai Lake and from 80 to 2320 ind./m2 in Krivaya Channel. The low population density (< 40 ind./m2) in Gryaznoe Lake, together with the absence of the species in the waters of the former Zhilishchenskoe Lake, confirms the indications of population density decline in the associated waters of the delta. Population growth of G. lacustris was limited primarily by changes in the hydromorphology of the lakes and waterways due to floods of the early 1990s and the subsequent period of extremely low flow of the Selenga River.

Thermal Preference Ranges Correlate with Stable Signals of Universal Stress Markers in Lake Baikal Endemic and Holarctic Amphipods

PubMed Central

Axenov-Gribanov, Denis; Bedulina, Daria; Shatilina, Zhanna; Jakob, Lena; Vereshchagina, Kseniya; Lubyaga, Yulia; Gurkov, Anton; Shchapova, Ekaterina; Luckenbach, Till; Lucassen, Magnus; Sartoris, Franz Josef; Pörtner, Hans-Otto; Timofeyev, Maxim

2016-01-01

Temperature is the most pervasive abiotic environmental factor for aquatic organisms. Fluctuations in temperature range lead to changes in metabolic performance. Here, we aimed to identify whether surpassing the thermal preference zones is correlated with shifts in universal cellular stress markers of protein integrity, responses to oxidative stress and lactate content, as indicators of anaerobic metabolism. Exposure of the Lake Baikal endemic amphipod species Eulimnogammarus verrucosus (Gerstfeldt, 1858), Ommatogammarus flavus (Dybowski, 1874) and of the Holarctic amphipod Gammarus lacustris Sars 1863 (Amphipoda, Crustacea) to increasing temperatures resulted in elevated heat shock protein 70 (Hsp70) and lactate content, elevated antioxidant enzyme activities (i.e., catalase and peroxidase), and reduced lactate dehydrogenase and glutathione S-transferase activities. Thus, the zone of stability (absence of any significant changes) of the studied molecular and biochemical markers correlated with the behaviorally preferred temperatures. We conclude that the thermal behavioral responses of the studied amphipods are directly related to metabolic processes at the cellular level. Thus, the determined thermal ranges may possibly correspond to the thermal optima. This relationship between species-specific behavioral reactions and stress response metabolism may have significant ecological consequences that result in a thermal zone-specific distribution (i.e., depths, feed spectrum, etc.) of species. As a consequence, by separating species with different temperature preferences, interspecific competition is reduced, which, in turn, increases a species’ Darwinian fitness in its environment. PMID:27706227

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

PubMed

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).

Crustacean amphipods from marsh ponds: a nutritious feed resource with potential for application in Integrated Multi-Trophic Aquaculture.

PubMed

Jiménez-Prada, Pablo; Hachero-Cruzado, Ismael; Giráldez, Inmaculada; Fernández-Diaz, Catalina; Vilas, César; Cañavate, José Pedro; Guerra-García, José Manuel

2018-01-01

Coastal protection, nutrient cycling, erosion control, water purification, and carbon sequestration are ecosystem services provided by salt marshes. Additionally, salt ponds offer coastal breeding and a nursery habitat for fishes and they provide abundant invertebrates, such as amphipods, which are potentially useful as a resource in aquaculture. Fishmeal and fish oil are necessary food resources to support aquaculture of carnivorous species due to their omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA). Currently, aquaculture depends on limited fisheries and feed with elevated n-3 LC-PUFA levels, but the development of more sustainable food sources is necessary. Amphipods appear to be a potential high quality alternative feed resource for aquaculture. Hence, a nutritional study was carried out for several main amphipod species- Microdeutopus gryllotalpa , Monocorophium acherusicum , Gammarus insensibilis , Melita palmata and Cymadusa filosa -in terrestrial ponds in the South of Spain. These species showed high protein content (up to 40%), high n-3 PUFA and phospholipid levels, and high levels of phophatidylcholine (PC), phosphatidylethanolamine (PE) and triacylglycerols (TAG), the latter being significantly high for M. acherusicum . M. gryllotalpa and M. acherusicum showed the highest proportion of lipids (19.15% and 18.35%, respectively). Isoleucine, glycine and alanine were the dominant amino acids in all species. In addition, amphipods collected from ponds showed low levels of heavy metals. Furthermore, the biochemical profiles of the five species of amphipods have been compared with other studied alternative prey. Therefore, pond amphipods are good candidates to be used as feed, and are proposed as a new sustainable economic resource to be used in aquaculture. G. insensibilis may be the best for intensive culture as an alternative feed resource because it shows: (1) adequate n-3 PUFA and PL composition; (2) high levels of glycine, alanine, tyrosine

Crustacean amphipods from marsh ponds: a nutritious feed resource with potential for application in Integrated Multi-Trophic Aquaculture

PubMed Central

Hachero-Cruzado, Ismael; Giráldez, Inmaculada; Fernández-Diaz, Catalina; Vilas, César; Cañavate, José Pedro; Guerra-García, José Manuel

2018-01-01

Coastal protection, nutrient cycling, erosion control, water purification, and carbon sequestration are ecosystem services provided by salt marshes. Additionally, salt ponds offer coastal breeding and a nursery habitat for fishes and they provide abundant invertebrates, such as amphipods, which are potentially useful as a resource in aquaculture. Fishmeal and fish oil are necessary food resources to support aquaculture of carnivorous species due to their omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA). Currently, aquaculture depends on limited fisheries and feed with elevated n-3 LC-PUFA levels, but the development of more sustainable food sources is necessary. Amphipods appear to be a potential high quality alternative feed resource for aquaculture. Hence, a nutritional study was carried out for several main amphipod species—Microdeutopus gryllotalpa, Monocorophium acherusicum, Gammarus insensibilis, Melita palmata and Cymadusa filosa—in terrestrial ponds in the South of Spain. These species showed high protein content (up to 40%), high n-3 PUFA and phospholipid levels, and high levels of phophatidylcholine (PC), phosphatidylethanolamine (PE) and triacylglycerols (TAG), the latter being significantly high for M. acherusicum. M. gryllotalpa and M. acherusicum showed the highest proportion of lipids (19.15% and 18.35%, respectively). Isoleucine, glycine and alanine were the dominant amino acids in all species. In addition, amphipods collected from ponds showed low levels of heavy metals. Furthermore, the biochemical profiles of the five species of amphipods have been compared with other studied alternative prey. Therefore, pond amphipods are good candidates to be used as feed, and are proposed as a new sustainable economic resource to be used in aquaculture. G. insensibilis may be the best for intensive culture as an alternative feed resource because it shows: (1) adequate n-3 PUFA and PL composition; (2) high levels of glycine, alanine, tyrosine

First endemic freshwater Gammarus from Crete and its evolutionary history-an integrative taxonomy approach.

PubMed

Hupało, Kamil; Mamos, Tomasz; Wrzesińska, Weronika; Grabowski, Michał

2018-01-01

The Mediterranean islands are known as natural laboratories of evolution with a high level of endemic biodiversity. However, most biodiversity assessments have focused mainly on terrestrial and marine fauna, leaving the freshwater animals aside. Crete is one of the largest islands in the Mediterranean Basin, with a long history of isolation from the continental mainland. Gammarid amphipods are often dominant in macrozoobenthic communities in European inland waters. They are widely used in biomonitoring and exotoxicological studies. Herein, we describe Gammarus plaitisi sp. nov., endemic to Cretan streams, based on morphological characters and a set of molecular species delimitation methods using mitochondrial cytochrome oxidase subunit I and 16S rRNA genes as well as nuclear 28S rDNA, ITS1 and EF1-alpha genes. The divergence of the new species is strongly connected with the geological history of the island supporting its continental origin.

Potential effects of recurrent low oxygen conditions on the Illinois Cave amphipod

USGS Publications Warehouse

Panno, S.V.; Hackley, Keith C.; Kelly, W.R.; Hwang, H.-H.; Wilhelm, F.M.; Taylor, S.J.; Stiff, B.J.

2006-01-01

The caves of Illinois' sinkhole plain are the sole habitat of the Illinois Cave amphipod (Gammarus acherondytes), a federally endangered species. The sinkhole plain is a hydrologically-connected sequence of karstified limestone that constitutes an extensive karst aquifer which serves as an important source of potable water for area residents. During this investigation, we examined the ground-water quality in caves within two ground-water basins: 1) Illinois Caverns, where the amphipod is now present after previously reported to have been extirpated from the lower reaches, and 2) Stemler Cave, where the amphipod is reported to have been extirpated. The chemical composition of cave streams in Illinois Caverns and Stemler Cave were compared to determine which parameters, if any, could have contributed to the loss of G. acherondytes from Stemler Cave. Stream water in Stemler Cave contained higher concentrations of organic carbon, potassium, silica, chloride, fluoride, sulfate, iron and manganese than Illinois Caverns. Perhaps most importantly, dissolved oxygen (DO) concentrations in Stemler Cave were, during periods of low flow, substantially lower than in Illinois Caverns. Based on land use, there are probably at least eight times more private septic systems in the Stemler Cave ground-water basin than in the Illinois Caverns ground-water basin. Low DO concentrations were likely the result of microbial breakdown of soil organic matter and wastewater treatment system effluent, and the oxidation of pyrite in bedrock. The near-hypoxic DO in Stemler Cave that occurred during low-flow conditions, and, we speculate, a limited range of G. acherondytes within the Stemler Cave ground-water basin due to a metabolic advantage of the stygophilic aquatic invertebrates over the stygobitic G. acherodytes, resulted in the apparent loss of G. acherondytes from Stemler Cave.

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

USGS Publications Warehouse

Anteau, M.J.; Afton, A.D.; Anteau, A.C.E.; Moser, E.B.

2010-01-01

Gammarus lacustris and 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<0.001 and P<0.001, respectively). Both species were negatively correlated with densities of large fish (non-Cyprinidae; P = 0.01 and P = 0.013, respectively) and with high densities of fathead minnows (Pimephales promelas; P<0.001 and 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<0.001). 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. ?? Springer Science+Business Media B.V. (outside the USA) 2011.

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

Biodegradable and Petroleum-Based Microplastics Do Not Differ in Their Ingestion and Excretion but in Their Biological Effects in a Freshwater Invertebrate Gammarus fossarum

PubMed Central

Straub, Sandrine; Hirsch, Philipp E.; Burkhardt-Holm, Patricia

2017-01-01

Research on the uptake and effects of bioplastics by aquatic organisms is still in its infancy. Here, we aim to advance the field by comparing uptake and effects of microplastic particles (MPP) of a biodegradable bioMPP (polyhydroxybutyrate (PHB)) and petroleum-based MPP (polymethylmethacrylate (PMMA)) in the freshwater amphipod Gammarus fossarum. Ingestion of both MPP in different particle sizes (32–250 µm) occurred after 24 h, with highest ingestion of particles in the range 32–63 µm and almost complete egestion after 64 h. A four-week effect-experiment showed a significant decrease of the assimilation efficiency in amphipods exposed to the petroleum-based MPP from week two onwards. The petroleum-based PMMA affected assimilation efficiency significantly in contrast to the biodegradable PHB, but overall differences in direct comparison of MPP types were small. Both MPP types led to a significantly lower wet weight gain relative to the control treatments. After four weeks, differences between both MPP types and silica, used as a natural particle control, were detected. In summary, these results suggest that both MPP types provoke digestive constraints on the amphipods, which go beyond those of natural non-palatable particles. This highlights the need for more detailed research comparing environmental effects of biodegradable and petroleum-based MPP and testing those against naturally occurring particle loads. PMID:28703776

Effects of increased temperatures on Gammarus fossarum under the influence of copper sulphate.

PubMed

Schmidlin, Lara; von Fumetti, Stefanie; Nagel, Peter

2015-03-01

The specialised fauna of freshwater springs will have to cope with a possible temperature rise owing to Global Change. It is affected additionally by contamination of the water with xenobiotics from human activities in the surrounding landscape. We assessed the combined effects of temperature increase and exposure to toxins in laboratory experiments by using copper sulphate as a model substance and Gammarus fossarum Koch, 1835, as the model organism. This amphipod is a common representative of the European spring fauna and copper ions are widespread contaminants, mainly from agricultural practice. The experiments were conducted in boxes placed in flow channels and the water temperatures were varied. The gammarids were fed with conditioned beech leaf discs. The feeding activity of the amphipods was quantified on the level of the organism; and the respiratory electron transport system (ETS) assay was conducted in order to determine changes on the cellular level in the test organisms. The results show that the feeding activity increased slightly with higher water temperature. The sub-lethal copper dose had no significant effect other than a trend towards lower feeding activity. The ETS activity was significantly higher at the higher water temperatures, and the copper ions significantly lowered the ETS activity of the organisms. The combination of the two methods was useful when testing for combined effects of environmental changes and pollutants on a species. From the results one can reasonably infer a higher risk of adverse effects with increase in water temperature and exposure to a particular heavy metal.

Different natural organic matter isolates cause similar stress response patterns in the freshwater amphipod, Gammarus pulex.

PubMed

Bedulina, Darya S; Timofeyev, Maxim A; Zimmer, Martin; Zwirnmann, Elke; Menzel, Ralph; Steinberg, Christian E W

2010-02-01

Dissolved humic substances (HSs) are exogenous stressors to aquatic plants and animals which activate a variety of transcriptional and biochemical reactions or block photosynthesis. While there are consistent indications which structures may lead to reduced photosynthetic activity, there is much less clear information available on which HS structures or building blocks act as stressors in animals. Consequently, this work was designed to comparatively study the impact of natural organic matter (NOMs) from different sources on major anti-stress mechanisms in one single animal. We utilized major antioxidant responses and relative expression levels of stress proteins (small HSPs and HSP70) and expected that different HSs provoke different response patterns. We tested the freshwater amphipod Gammarus pulex which was collected from several shallow creeks in Northern Germany. All specimens were maintained in aerated 5-L tanks with filtered water from their natural environment at 10 degrees C with prior acclimation. Animals were fed ad libitum with a commercial preparation once every second day. The exposure water was exchanged with the same frequency. NOMs were isolated from three different sources: two from small brown-water lakes in Northern Germany by reverse osmosis and the third one as an aqueous extract from a black layer of a Brazilian sandbar soil (State of Rio de Janeiro). The rationale was to apply NOMs of contrasting quality. Chemical fingerprint features of the NOMs were taken by high-performance size exclusion chromatography. As stress parameters in the animals, the activities of peroxidase and catalase were recorded quantitatively, and stress proteins, HSP70, as well as small alpha-crystalline HSPs were analyzed semiquantitatively. The three NOMs clearly differed in molecular masses, humic substance contents, the moieties of polysaccharides, and low-molecular-weight substances. With the exception of one short-term response, the peroxidase activity increased

Comparative Study of Biological Activities of Venom from Colubrid Snakes Rhabdophis tigrinus (Yamakagashi) and Rhabdophis lateralis

PubMed Central

Komori, Yumiko; Hifumi, Toru; Yamamoto, Akihiko; Sakai, Atsushi; Sawabe, Kyoko; Nikai, Toshiaki

2017-01-01

Rhabdophis lateralis, a colubrid snake distributed throughout the continent of Asia, has recently undergone taxonomic revisions. Previously, Rhabdophis lateralis was classified as a subspecies of R. tigrinus (Yamakagashi) until 2012, when several genetic differences were discovered which classified this snake as its own species. To elucidate the toxicity of venom from this poorly studied colubrid, various biological activities were compared between the venom from the two snake species. The components of their venom were compared by the elution profiles of reversed-phase HPLC and SDS-PAGE, and gel filtrated fractions were tested for effects on blood coagulation. Proteolytic activities of these fractions were also assayed by using synthetic substrates, fibrinogen, and matrix proteins. Similar to the R. tigrinus venom, the higher molecular weight fraction of R. lateralis venom contained a prothrombin activator. Both prothrombin time (PT) and activated partial thromboplastin time (APTT) of human plasma were shortened by the addition of R. lateralis and R. tigrinus venom. The thrombin formation was estimated by the uses of SDS-PAGE and chromogenic substrates. These venom fractions also possessed very specific proteinase activity on human fibrinogen, but the substrates for matrix metalloproteinase, such as collagen and laminin, were not hydrolyzed. However, there were some notable differences in reactivity to synthetic substrates for matrix metalloproteinase, and R. tigrinus venom possessed relatively higher activity. Our chemical investigation indicates that the components included in both venoms resemble each other closely. However, the ratio of components and proteolytic activity of some ingredients are slightly different, indicating differences between two closely-related snakes. PMID:29149042

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.

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).

Uptake and effects of americium-241 on a brackishwater amphipod

NASA Astrophysics Data System (ADS)

Hoppenheit, M.; Murray, C. N.; Woodhead, D. S.

1980-03-01

The present paper reports the results of experimental work undertaken using the brackish-water amphipod Gammarus duebeni duebeni and the transuranium nuclide americium-241. Data on the accumulation of this actinide showed that the larger fraction of the total body burden is associated with the exoskeleton. It was found that the body burden remained constant in the range pH 8.0 6.5 even though the water concentrations changed markedly. It would thus appear that the concept of a concentration factor should be re-examined and it is proposed that a factor should be defined in terms of environmental and chemical parameters which represent the bioavailable fraction of the actinide. The effect of americium on survival and moulting was studied at two activity concentrations; the dose rates and absorbed doses under the experimental conditions employed have been estimated. The differences in survival rates between the control and irradiated groups were statistically analyzed and the significant difference at the higher concentration is believed to be due to a synergism between physiological stress and radiotoxicity of americium rather than the chemical toxicity of the element.

Infection with an acanthocephalan manipulates an amphipod's reaction to a fish predator's odours.

PubMed

Baldauf, Sebastian A; Thünken, Timo; Frommen, Joachim G; Bakker, Theo C M; Heupel, Oliver; Kullmann, Harald

2007-01-01

Many parasites with complex life cycles increase the chances of reaching a final host by adapting strategies to manipulate their intermediate host's appearance, condition or behaviour. The acanthocephalan parasite Pomphorhynchus laevis uses freshwater amphipods as intermediate hosts before reaching sexual maturity in predatory fish. We performed a series of choice experiments with infected and uninfected Gammarus pulex in order to distinguish between the effects of visual and olfactory predator cues on parasite-induced changes in host behaviour. When both visual and olfactory cues, as well as only olfactory cues were offered, infected and uninfected G. pulex showed significantly different preferences for the predator or the non-predator side. Uninfected individuals significantly avoided predator odours while infected individuals significantly preferred the side with predator odours. When only visual contact with a predator was allowed, infected and uninfected gammarids behaved similarly and had no significant preference. Thus, we believe we show for the first time that P. laevis increases its chance to reach a final host by olfactory-triggered manipulation of the anti-predator behaviour of its intermediate host.

Seven new freshwater species of Gammarus from southern China (Crustacea, Amphipoda, Gammaridae)

PubMed Central

Hou, Zhonge; Zhao, Shuangyan; Li, Shuqiang

2018-01-01

Abstract Seven new species of the genus Gammarus are described and illustrated from southern China. The new species Gammarus vallecula Hou & Li, sp. n., G. qinling Hou & Li, sp. n., G. zhigangi Hou & Li, sp. n. and G. jidutanxian Hou & Li, sp. n. are characterized by inner ramus of uropod III half the length of outer ramus. Gammarus longdong Hou & Li, sp. n. is characterized by inner ramus of uropod III 0.9 times as long as outer ramus. Gammarus mosuo Hou & Li, sp. n. is characterized by pereopods V–VII with long setae on anterior margins and both rami of uropod III armed with simple setae. Gammarus caecigenus Hou & Li, sp. n. can be distinguished from other species by eyes absent. DNA barcodes of the new species are documented as proof of molecular differences between species. A key to the new species and a map of their distributions are provided. PMID:29674920

Antioxidant and antibacterial activities of acetonitrile and hexane extracts of Lentinus tigrinus and Pleurotus djamour

USDA-ARS?s Scientific Manuscript database

This paper highlighted the antioxidant and antibacterial activities of Lentinus tigrinus and Pleurotus djamour. Extracts of mushroom fruiting bodies were obtained using hexane and acetonitrile solvents. Acetonitrile extracts of both mushrooms exhibited higher biological activities than hexane extrac...

Transgenerational deleterious effects of ocean acidification on the reproductive success of a keystone crustacean (Gammarus locusta).

PubMed

Borges, Francisco O; Figueiredo, Cátia; Sampaio, Eduardo; Rosa, Rui; Grilo, Tiago F

2018-07-01

Ocean acidification (OA) poses a global threat to marine biodiversity. Notwithstanding, marine organisms may maintain their performance under future OA conditions, either through acclimation or evolutionary adaptation. Surprisingly, the transgenerational effects of high CO 2 exposure in crustaceans are still poorly understood. For the first time, the present study investigated the transgenerational effect of OA, from hatching to maturity, of a key amphipod species (Gammarus locusta). Negative transgenerational effects were observed on survival of the acidified lineage, resulting in significant declines (10-15%) compared to the control groups in each generation. Mate-guarding duration was also significantly reduced under high CO 2 and this effect was not alleviated by transgenerational acclimation, indicating that precopulatory behaviours can be disturbed under a future high CO 2 scenario. Although OA may initially stimulate female investment, transgenerational exposure led to a general decline in egg number and fecundity. Overall, the present findings suggest a potential fitness reduction of natural populations of G. locusta in a future high CO 2 ocean, emphasizing the need of management tools towards species' sustainability. Copyright © 2018 Elsevier Ltd. All rights reserved.

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. Copyright © 2010 Elsevier B.V. All rights reserved.

Anxiety-like behaviour increases safety from fish predation in an amphipod crustacea

PubMed Central

Banchetry, Loan; Cézilly, Frank

2017-01-01

Anxiety is an emotional state generally expressed as sustained apprehension of the environment and elevated vigilance. It has been widely reported in vertebrates and, more recently, in a few invertebrate species. However, its fitness value remains elusive. We investigated anxiety-like behaviour and its consequences in an amphipod crustacean, using electric shock as aversive stimuli, and pharmacological assays. An anxiety-like state induced by electric shocks in Gammarus fossarum was expressed through increased sheltering behaviour in the absence of predation risk, thereby showing the pervasive nature of such behavioural response. Increasing the number of electric shocks both increased refuge use and delayed behavioural recovery. The behavioural effect of electric shock was mitigated by pre-treatment with LY354740, a metabotropic glutamate receptor group II/III agonist. Importantly, we found that this modulation of decision-making under an anxiety-like state resulted in an increased survival to predation in microcosm experiments. This study confirms the interest in taking an evolutionary view to the study of anxiety and calls for further investigation on the costs counterbalancing the survival benefit of an elevated anxiety level evidenced here. PMID:29308271

Anxiety-like behaviour increases safety from fish predation in an amphipod crustacea.

PubMed

Perrot-Minnot, Marie-Jeanne; Banchetry, Loan; Cézilly, Frank

2017-12-01

Anxiety is an emotional state generally expressed as sustained apprehension of the environment and elevated vigilance. It has been widely reported in vertebrates and, more recently, in a few invertebrate species. However, its fitness value remains elusive. We investigated anxiety-like behaviour and its consequences in an amphipod crustacean, using electric shock as aversive stimuli, and pharmacological assays. An anxiety-like state induced by electric shocks in Gammarus fossarum was expressed through increased sheltering behaviour in the absence of predation risk, thereby showing the pervasive nature of such behavioural response. Increasing the number of electric shocks both increased refuge use and delayed behavioural recovery. The behavioural effect of electric shock was mitigated by pre-treatment with LY354740, a metabotropic glutamate receptor group II/III agonist. Importantly, we found that this modulation of decision-making under an anxiety-like state resulted in an increased survival to predation in microcosm experiments. This study confirms the interest in taking an evolutionary view to the study of anxiety and calls for further investigation on the costs counterbalancing the survival benefit of an elevated anxiety level evidenced here.

Adaptive Sex Determination and Population Dynamics in a Brackish-water Amphipod

NASA Astrophysics Data System (ADS)

Watt, Penelope J.; Adams, Jonathan

1993-09-01

Gammarus duebeni is a sexually dimorphic amphipod with an unusual and environmentally mediated sex determining system. In seasonal populations, environmental sex determination (ESD) is selectively advantageous and males and females are produced at different times of the year, but it has been predicted that where generations overlap or the breeding season is long, ESD should no longer have a selective advantage over genetic mechanisms of sex determination and males and females should be produced simultaneously. The dynamics of a supposedly bivoltine population at Totton Marsh on the south coast of England were investigated. The field study showed that the breeding season at Totton was not in fact bivoltine but long, extending through most of the year with a short break in early summer. Population sex ratio fluctuated seasonally: this pattern appears to be the product of differences in production of males and females rather than growth or mortality. Thus, contrary to expectations, ESD does occur in this population. Photoperiod is the cue for sex determination in the laboratory, but in the field this alone could not account for the observed pattern of male and female production at Totton Marsh. Another major variable must be involved and it is proposed that it also has an influence on other G. duebeni populations.

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.

Carotenoids of two freshwater amphipod species (Gammarus pulex and G. roeseli) and their common acanthocephalan parasite Polymorphus minutus.

PubMed

Gaillard, Maria; Juillet, Cédrik; Cézilly, Frank; Perrot-Minnot, Marie-Jeanne

2004-09-01

Carotenoid compositions of two freshwater Gammarus species (Crustacea: Amphipoda) and of their common acanthocephalan parasite Polymorphus minutus were characterized. The effect of carotenoid uptake by the parasite was addressed by comparing the carotenoid content of uninfected and infected female hosts. Using high-pressure liquid chromatography (HPLC), co-chromatography of reference pigments and electron ionization mass spectrometry of collected HPLC fractions (EI-MS), several xanthophylls and non-polar compounds were identified. Seven kinds of carotenoids, mainly xanthophylls, were identified in gammarids. Astaxanthin was predominant, amounting to 40 wt.% of total carotenoid in both uninfected G. pulex and G. roeseli. By contrast, we found only non-polar compounds with a predominance of esterified forms of astaxanthin in P. minutus larvae. No significant effect of infection on carotenoid content was evidenced in G. pulex and G. roeseli females. Our study highlights the use of a Matrix Solid Phase Dispersion as an efficient extraction method of both xanthophylls and non-polar pigments in small samples, including lipid-rich ones as P. minutus parasite. We discuss on the presumptive pathway leading to the formation of free astaxanthin in gammarids via hydroxy compounds, and on the accumulation of esters of astaxanthin in parasites.

Microphallids in Gammarus insensibilis Stock, 1966 from a Black Sea lagoon: manipulation hypothesis going East?

PubMed

Kostadinova, A; Mavrodieva, R S

2005-09-01

Patterns of parasite site selection, variation in infection parameters and interspecific associations are examined in the light of new field data on larval microphallids in Gammarus insensibilis from a Black Sea lagoon. These patterns are discussed in relation to the predictions for the manipulative effect of Microphallus papillorobustus and its relationships with the other microphallid species based on studies on the French Mediterranean coast. Four species were recovered: Maritrema subdolum, Microphallus hoffmanni, M. papillorobustus and Levinseniella propinqua. The latter two were located in both corporal and cephalic segments, but the selection of brain appeared stronger for L. propinqua. M. subdolum was the first colonizer of amphipod population recruits, and unequivocally the dominant species in the lagoon. There was a significant positive relationship between the parasite load of all 4 species. Concurrent infections were exceedingly frequent, and no departures from random association were detected. We found no evidence that the cerebral metacercariae of M. papillorobustus consistently predict the parasite load of any of the other species in the system and identify sources for heterogeneity that may account for the differences between the Black Sea and the Mediterranean system: habitat heterogeneity, bird diversity and host-parasite systems used to infer relationships between microphallids.

The Insecticide Imidacloprid Causes Mortality of the Freshwater Amphipod Gammarus pulex by Interfering with Feeding Behavior

PubMed Central

Nyman, Anna-Maija; Hintermeister, Anita; Schirmer, Kristin; Ashauer, Roman

2013-01-01

If an organism does not feed, it dies of starvation. Even though some insecticides which are used to control pests in agriculture can interfere with feeding behavior of insects and other invertebrates, the link from chemical exposure via affected feeding activity to impaired life history traits, such as survival, has not received much attention in ecotoxicology. One of these insecticides is the neonicotinoid imidacloprid, a neurotoxic substance acting specifically on the insect nervous system. We show that imidacloprid has the potential to indirectly cause lethality in aquatic invertebrate populations at low, sublethal concentrations by impairing movements and thus feeding. We investigated feeding activity, lipid content, immobility, and survival of the aquatic arthropod Gammarus pulex under exposure to imidacloprid. We performed experiments with 14 and 21 days duration, both including two treatments with two high, one day pulses of imidacloprid and one treatment with a low, constant concentration. Feeding of G. pulex as well as lipid content were significantly reduced under exposure to the low, constant imidacloprid concentration (15 µg/L). Organisms were not able to move and feed – and this caused high mortality after 14 days of constant exposure. In contrast, feeding and lipid content were not affected by repeated imidacloprid pulses. In these treatments, animals were mostly immobilized during the chemical pulses but did recover relatively fast after transfer to clean water. We also performed a starvation experiment without exposure to imidacloprid which showed that starvation alone does not explain the mortality in the constant imidacloprid exposure. Using a multiple stressor toxicokinetic-toxicodynamic modeling approach, we showed that both starvation and other toxic effects of imidacloprid play a role for determining mortality in constant exposure to the insecticide. PMID:23690941

Do differences in sensitivity between native and invasive amphipods explain their coexistence in Lake Constance? A case study with lambda-cyhalothrin.

PubMed

Bundschuh, Mirco; Gergs, René; Schadt, Sebastian; Schulz, Ralf

2013-07-01

Invasive species are considered as one of the major threats for biodiversity worldwide. The Ponto-Caspian species Dikerogammarus villosus, for instance, spread throughout continental Europe and was recorded for the first time also within Lake Constance in 2003. Although D. villosus is a highly competitive species it was not capable of replacing the native Gammarus roeselii completely in this ecosystem, especially in the riparian zones of the highly agriculturally used island "Reichenau". As differences in pesticide sensitivity between both amphipod species may explain their distribution, the present study assessed the implication of the highly toxic pyrethroid lambda-cyhalothrin, which is authorized for application in the Lake Constance region, assuming the invasive species being more sensitive than the native one. However, both the feeding activity bioassays, which measured the leaf consumption over 7d (n=20), as well as the predation bioassay, which measured the predation rate upon Baetis nymphs in concert with the feeding activity on leaf material over 96 h (n=13), revealed an up to 5-fold higher tolerance of D. villosus towards lambda-cyhalothrin. These results suggest the investigated insecticide not being the trigger for the observed distribution pattern of both amphipod species. Hence, other factors like the diversity of habitat structures or the levels of ammonia may have facilitated the coexistence. Nevertheless, the present study uncovered a high leaf-shredding efficacy of the invasive species D. villosus suggesting that its role in the leaf decomposition process may have been underestimated in the past. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

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...

Antibiotic mixture effects on growth of the leaf-shredding stream detritivore Gammarus fossarum.

PubMed

Bundschuh, Mirco; Hahn, Torsten; Gessner, Mark O; Schulz, Ralf

2017-05-01

Pharmaceuticals contribute greatly to human and animal health. Given their specific biological targets, pharmaceuticals pose a significant environmental risk by affecting organisms and ecosystem processes, including leaf-litter decomposition. Although litter decomposition is a central process in forest streams, the consequences of exposure to pharmaceuticals remain poorly known. The present study assessed the impact of antibiotics as an important class of pharmaceuticals on the growth of the leaf-shredding amphipod Gammarus fossarum over 24 days. Exposure scenarios involved an antibiotic mixture (i.e. sulfamethoxazole, trimethoprim, erythromycin-H 2 O, roxithromycin, clarithromycin) at 0, 2 and 200 µg/L to assess impacts resulting from exposure to both water and food. The antibiotics had no effect on either leaf-associated fungal biomass or bacterial abundance. However, modification of leaf quality (e.g. through shifts in leaf-associated microbial communities) may have triggered faster growth of gammarids (assessed in terms of body mass gain) at the low antibiotic concentration relative to the control. At 200 µg/L, however, gammarid growth was not stimulated. This outcome might be due to a modified ability of the gut microflora to assimilate nutrients and carbon. Furthermore, the observed lack of increases in the diameter of the gammarids' peduncles, despite an increase in gammarid mass, suggests antibiotic-induced effects in the moulting cycle. Although the processes responsible for the observed effects have not yet been identified, these results suggest a potential role of food-quality, gammarid gut microflora and alteration in the moulting cycle in mediating impacts of antibiotics on these detritivores and the leaf decomposition process in streams.

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

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…

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.

Genome size variation in deep-sea amphipods

PubMed Central

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

2017-01-01

Genome size varies considerably across taxa, and extensive research effort has gone into understanding whether variation can be explained by differences in key ecological and life-history traits among species. The extreme environmental conditions that characterize the deep sea have been hypothesized to promote large genome sizes in eukaryotes. Here we test this supposition by examining genome sizes among 13 species of deep-sea amphipods from the Mariana, Kermadec and New Hebrides trenches. Genome sizes were estimated using flow cytometry and found to vary nine-fold, ranging from 4.06 pg (4.04 Gb) in Paralicella caperesca to 34.79 pg (34.02 Gb) in Alicella gigantea. Phylogenetic independent contrast analysis identified a relationship between genome size and maximum body size, though this was largely driven by those species that display size gigantism. There was a distinct shift in the genome size trait diversification rate in the supergiant amphipod A. gigantea relative to the rest of the group. The variation in genome size observed is striking and argues against genome size being driven by a common evolutionary history, ecological niche and life-history strategy in deep-sea amphipods. PMID:28989783

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. Copyright © 2015 Elsevier Inc. All rights reserved.

Safety of the molluscicide Zequanox (R) to nontarget macroinvertebrates Gammarus lacustris (Amphipoda: Gammaridae) and Hexagenia spp. (Ephemeroptera: Ephemeridae)

USGS Publications Warehouse

Waller, Diane L.; Luoma, James A.; Erickson, Richard A.

2016-01-01

Zequanox® is a commercial formulation of the killed bacterium, Pseudomonas fluorescens (strain CL145A), that was developed to control dreissenid mussels. In 2014, Zequanox became the second product registered by the United States Environmental Protection Agency (USEPA) for use in open water environments as a molluscicide. Previous nontarget studies demonstrated the safety and selectivity of P. fluorescens CL154A, but the database on the toxicity of the formulation (Zequanox) is limited for macroinvertebrate taxa and exposure conditions. We evaluated the safety of Zequanox to the amphipod Gammarus lacustris lacustris, and nymphs of the burrowing mayfly, Hexagenia spp. at the maximum approved concentration (100 mg/L active ingredient, A.I.) and exposure duration (8 h). Survival of animals was assessed after 8 h of exposure and again at 24 and 96 h post-exposure. Histopathology of the digestive tract of control and treated animals was compared at 96 h post-exposure. The results showed no significant effect of Zequanox on survival of either species. Survival of G. lacustris exceeded 85% in all concentrations at all three sampling time points. Survival of Hexagenia spp. ranged from 71% (control) to 91% at 8 h, 89–93% at 24 h post-exposure, and 70–73% at 96 h post-exposure across all treatments. We saw no evidence of pathology in the visceral organs of treated animals. Our results indicate that application of Zequanox at the maximum approved concentration and exposure duration did not cause significant mortality or treatment-related histopathological changes to G. lacustris and Hexagenia spp.

Effects of two commonly used fungicides on the amphipod Austrochiltonia subtenuis.

PubMed

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

2017-03-01

Fungicides are used widely in agriculture and have been detected in adjacent rivers and wetlands. However, relatively little is known about the potential effects of fungicides on aquatic organisms. The present study investigated the effects of 2 commonly used fungicides, the boscalid fungicide Filan ® and the myclobutanil fungicide Systhane ™ 400 WP, on life history traits (survival, growth, and reproduction) and energy reserves (lipid, protein, and glycogen content) of the amphipod Austrochiltonia subtenuis under laboratory conditions, at concentrations detected in aquatic environments. Amphipods were exposed to 3 concentrations of Filan (1 μg active ingredient [a.i.]/L, 10 μg a.i./L, and 40 μg a.i./L) and Systhane (0.3 μg a.i./L, 3 μg a.i./L, and 30 μg a.i./L) over 56 d. Both fungicides had similar effects on the amphipod at the organism level. Reproduction was the most sensitive endpoint, with offspring produced in controls but none produced in any of the fungicide treatments, and total numbers of gravid females in all fungicide treatments were reduced by up to 95%. Female amphipods were more sensitive than males in terms of growth. Systhane had significant effects on survival at all concentrations, whereas significant effects of Filan on survival were observed only at 10 μg a.i./L and 40 μg a.i./L. The effects of fungicides on energy reserves of the female amphipod were different. Filan significantly reduced amphipod protein content, whereas Systhane significantly reduced the lipid content. The present study demonstrates wide-ranging effects of 2 common fungicides on an ecologically important species that has a key role in trophic transfer and nutrient recycling in aquatic environments. These results emphasize the importance of considering the long-term effects of fungicides in the risk assessment of aquatic ecosystems. Environ Toxicol Chem 2017;36:720-726. © 2016 SETAC. © 2016 SETAC.

Bioaccumulation of petroleum hydrocarbons in arctic amphipods in the oil development area of the Alaskan Beaufort Sea.

PubMed

Neff, Jerry M; Durell, Gregory S

2012-04-01

An objective of a multiyear monitoring program, sponsored by the US Department of the Interior, Bureau of Ocean Energy Management was to examine temporal and spatial changes in chemical and biological characteristics of the Arctic marine environment resulting from offshore oil exploration and development activities in the development area of the Alaskan Beaufort Sea. To determine if petroleum hydrocarbons from offshore oil operations are entering the Beaufort Sea food web, we measured concentrations of hydrocarbons in tissues of amphipods, Anonyx nugax, sediments, Northstar crude oil, and coastal peat, collected between 1999 and 2006 throughout the development area. Mean concentrations of polycyclic aromatic hydrocarbons (PAH), saturated hydrocarbons (SHC), and sterane and triterpane petroleum biomarkers (StTr) were not significantly different in amphipods near the Northstar oil production facility, before and after it came on line in 2001, and in amphipods from elsewhere in the study area. Forensic analysis of the profiles (relative composition and concentrations) of the 3 hydrocarbon classes revealed that hydrocarbon compositions were different in amphipods, surface sediments where the amphipods were collected, Northstar crude oil, and peat from the deltas of 4 North Slope rivers. Amphipods and sediments contained a mixture of petrogenic, pyrogenic, and biogenic PAH. The SHC in amphipods were dominated by pristane derived from zooplankton, indicating that the SHC were primarily from the amphipod diet of zooplankton detritus. The petroleum biomarker StTr profiles did not resemble those in Northstar crude oil. The forensic analysis revealed that hydrocarbons in amphipod tissues were not from oil production at Northstar. Hydrocarbons in amphipod tissues were primarily from their diet and from river runoff and coastal erosion of natural diagenic and fossil terrestrial materials, including seep oils, kerogens, and peat. Offshore oil and gas exploration and development

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.

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. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

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.

Diversity and distribution of genetic variation in gammarids: Comparing patterns between invasive and non-invasive species.

PubMed

Baltazar-Soares, Miguel; Paiva, Filipa; Chen, Yiyong; Zhan, Aibin; Briski, Elizabeta

2017-10-01

Biological invasions are worldwide phenomena that have reached alarming levels among aquatic species. There are key challenges to understand the factors behind invasion propensity of non-native populations in invasion biology. Interestingly, interpretations cannot be expanded to higher taxonomic levels due to the fact that in the same genus, there are species that are notorious invaders and those that never spread outside their native range. Such variation in invasion propensity offers the possibility to explore, at fine-scale taxonomic level, the existence of specific characteristics that might predict the variability in invasion success. In this work, we explored this possibility from a molecular perspective. The objective was to provide a better understanding of the genetic diversity distribution in the native range of species that exhibit contrasting invasive propensities. For this purpose, we used a total of 784 sequences of the cytochrome c oxidase subunit I of mitochondrial DNA (mtDNA-COI) collected from seven Gammaroidea, a superfamily of Amphipoda that includes species that are both successful invaders ( Gammarus tigrinus , Pontogammarus maeoticus, and Obesogammarus crassus ) and strictly restricted to their native regions ( Gammarus locusta , Gammarus salinus , Gammarus zaddachi, and Gammarus oceanicus ). Despite that genetic diversity did not differ between invasive and non-invasive species, we observed that populations of non-invasive species showed a higher degree of genetic differentiation. Furthermore, we found that both geographic and evolutionary distances might explain genetic differentiation in both non-native and native ranges. This suggests that the lack of population genetic structure may facilitate the distribution of mutations that despite arising in the native range may be beneficial in invasive ranges. The fact that evolutionary distances explained genetic differentiation more often than geographic distances points toward that deep lineage

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

USGS Publications Warehouse

Ingersoll, Chris G.; Brunson, Eric L.; Dwyer, F. James; Hardesty, Douglas K.; Kemble, Nile 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.

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.

Species associations among larval helminths in an amphipod intermediate host.

PubMed

Dezfuli, B S; Giari, L; Poulin, R

2000-10-01

Larval helminths that share the same intermediate host may or may not also share the same definitive hosts. If one or more of these helminth species can manipulate the phenotype of the intermediate host, there can be great advantages or severe costs for other helminths resulting from co-occurring with a manipulator, depending on whether they have the same definitive host or not. Among 2372 specimens of the amphipod Echinogammarus stammeri collected from the river Brenta, northern Italy, there was a positive association between two acanthocephalan species with the same fish definitive hosts, the relatively common Pomphorhynchus laevis and the much less prevalent Acanthocephalus clavula. The number of cystacanths of P. laevis per infected amphipod, which ranged from one to five, did not influence the likelihood that the amphipod would also host A. clavula. A third acanthocephalan species, Polymorphus minutus,which matures in birds, showed no association with either of the two other species. These results show that associations among helminth species in intermediate hosts are not random, and are instead the product of selection favouring certain pathways of transmission.

Feeding habits of amphipods (Crustacea: Malacostraca) from shallow soft bottom communities: Comparison between marine caves and open habitats

NASA Astrophysics Data System (ADS)

Navarro-Barranco, Carlos; Tierno-de-Figueroa, José Manuel; Guerra-García, José Manuel; Sánchez-Tocino, Luis; García-Gómez, José Carlos

2013-04-01

Marine caves are environments of great interest since the organisms that inhabit them are forced to develop specific adaptations to high constraint conditions. Because of some of these particular conditions, such as light absence or oligotrophy, it can be expected that feeding strategies into caves differ from that present outside them. Nevertheless, no studies have been done to compare the trophic structure of marine caves and open habitats, at least for amphipod communities, considering their importance both inside and outside of the caves. In this study, the diet of the dominant amphipod species living on shallow sediments, both inside and outside of six marine caves in western Mediterranean, was characterized. Thereby, the gut content of 17 amphipod species was studied, being this study the first attempt to establish the feeding habit of most of these species. Analysis of digestive contents of the species showed that amphipod diet is less diverse in sediments than in other environments, such as algae and seagrasses. No herbivorous species were found in the sediment and carnivorous amphipods showed a little variety of prey, feeding mainly on crustaceans. Differences in the trophic structure were also found between marine caves and open habitats sediments: while outside the caves detritivorous was the dominant group (both in number of species and number of individuals), amphipods mainly play the role of carnivorous inside the caves. No detritivorous species were found into the caves, where carnivorous represents almost 60% of amphipods species and more than 80% of amphipod individuals. This pattern obtained in amphipods differ from the general trend observed in marine cave organisms, for which a generalist diet, such as omnivory, usually is an advantage in these oligotrophic conditions. The possible causes of this pattern are discussed.

The physiological ecology of the supratidal amphipod Talorchestia longicornis.

PubMed

Ramus, Aaron P; Forward, Richard B

2012-02-01

Physiology, behavior, habitat, and morphology are used to determine the degree of adaptation to life on land for amphipod species and systemization within the four functional groups of the family talitridae. Talorchestia longicornis is a semi-terrestrial amphipod found in the supratidal zone of estuaries. The present study investigates the physiological adaptations of this species to life on land through measurements of osmoregulation and respiration. Over the salinity range of 1-40‰, T. longicornis regulated its hemolymph hyperosmotically at low salinities and hypoosmotically at high salinities. The isosmotic point was about 27‰. Analogously, hemolymph chloride levels were well regulated being hyperionic at low salinities and hypoionic at high salinities. This species is capable of respiration in both air and water. Slopes (b values) of the relationship between weight and oxygen uptake rates ranged from 0.316 to 0.590. Oxygen uptake rates were higher in air than water and at night versus day. Q(10) values were slightly below 2.0 for respiration in air for amphipods, irrespective of weight. These physiological adaptations, along with its behaviors, habitat, and morphology, place T. longicornis within the Group III sandhoppers of the Talitridae. Copyright © 2011. Published by Elsevier Inc.

Individual and joint toxicity of the herbicide S-metolachlor and a metabolite, deethylatrazine on aquatic crustaceans: Difference between ecological groups.

PubMed

Maazouzi, C; Coureau, C; Piscart, C; Saplairoles, M; Baran, N; Marmonier, P

2016-12-01

We studied the individual and joint acute toxicity of S-metolachlor (SMOC) and deethylatrazine (DEA - a metabolite of atrazine) on different non-target freshwater crustaceans. We used animals from different ecological groups: two amphipods from surface running water (Gammarus pulex and Gammarus cf. orinos), an isopod from surface stagnant water (Asellus aquaticus) and an amphipod living in groundwater (Niphargus rhenorhodanensis). Organisms were exposed to different levels of SMOC and DEA, alone or in binary mixture. Temperature effect on SMOC toxicity was assessed by exposing G. pulex and N. rhenorhodanensis to SMOC at 11 °C and 15 °C. Studying mortality as the biological endpoint, N. rhenorhodanensis was more resistant than surface water species towards SMOC and DEA. Among surface water species, G. pulex was the most sensitive while Gammarus cf. orinos and A. aquaticus showed similar responses to both compounds. Temperature increase did not change SMOC toxicity but modify the shape and steepness of the dose-response curve. We used a Model Deviation Ratio (MDR) approach to evaluate the predictability of Concentration Addition (CA) and Independent Action (IA) models to mixture toxicity. Results indicated either an additive or an antagonistic or a synergistic interaction depending on the concentrations combination and the test species. Our finding conclusively show the suitability of CA and IA in predicting mixture toxicities but results should be interpreted with caution according to ecological group of exposed species in risk assessment procedures. Copyright © 2016 Elsevier Ltd. All rights reserved.

AxIOM: Amphipod crustaceans from insular Posidonia oceanica seagrass meadows

PubMed Central

Heughebaert, André; Lepoint, Gilles

2016-01-01

Abstract Background The Neptune grass, Posidonia oceanica (L.) Delile, 1813, is the most widespread seagrass of the Mediterranean Sea. This foundation species forms large meadows that, through habitat and trophic services, act as biodiversity hotspots. In Neptune grass meadows, amphipod crustaceans are one of the dominant groups of vagile invertebrates, forming an abundant and diverse taxocenosis. They are key ecological components of the complex, pivotal, yet critically endangered Neptune grass ecosystems. Nevertheless, comprehensive qualitative and quantitative data about amphipod fauna found in Mediterranean Neptune grass meadows remain scarce, especially in insular locations. New information Here, we provide in-depth metadata about AxIOM, a sample-based dataset published on the GBIF portal. AxIOM is based on an extensive and spatially hierarchized sampling design with multiple years, seasons, day periods, and methods. Samples were taken along the coasts of Calvi Bay (Corsica, France) and of the Tavolara-Punta Coda Cavallo Marine Protected Area (Sardinia, Italy). In total, AxIOM contains 187 samples documenting occurrence (1775 records) and abundance (10720 specimens) of amphipod crustaceans belonging to 72 species spanning 29 families. The dataset is available at http://ipt.biodiversity.be/resource?r=axiom. PMID:27660521

PET microplastics do not negatively affect the survival, development, metabolism and feeding activity of the freshwater invertebrate Gammarus pulex.

PubMed

Weber, Annkatrin; Scherer, Christian; Brennholt, Nicole; Reifferscheid, Georg; Wagner, Martin

2018-03-01

Over the past decade, microscopic plastic debris, known as microplastics, emerged as a contaminant of concern in marine and freshwater ecosystems. Although regularly detected in aquatic environments, the toxicity of those synthetic particles is not well understood. To address this, we investigated whether the exposure to microplastics adversely affects the amphipod Gammarus pulex, a key freshwater invertebrate. Juvenile (6-9 mm) and adult (12-17 mm) individuals were exposed to irregular, fluorescent polyethylene terephthalate fragments (PET, 10-150 μm; 0.8-4,000 particles mL -1 ) for 24 h. Results show that body burden after 24 h depends on the dose and age of G. pulex with juveniles ingesting more microplastics than adults. After chronic exposure over 48 d, microplastics did not significantly affect survival, development (molting), metabolism (glycogen, lipid storage) and feeding activity of G. pulex. This demonstrates that even high concentrations of PET particles did not negatively interfere with the analyzed endpoints. These results contradict previous research on marine crustaceans. Differences may result from variations in the exposure regimes (e.g., duration, particle concentrations), plastic characteristics (e.g., type, size, shape, additives) as well as the species-specific morphological, physiological and behavioral traits. As a detritivorous shredder G. pulex is adapted to feed on non-digestible materials and might, therefore, be less sensitive towards exposure to synthetic particles. Accordingly, we argue that the autecology needs to be taken into account and that research should focus on identifying traits that render species susceptible to microplastic exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

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...

A model predicting waterborne cadmium bioaccumulation in Gammarus pulex: the effects of dissolved organic ligands, calcium, and temperature.

PubMed

Pellet, Bastien; Geffard, Olivier; Lacour, Céline; Kermoal, Thomas; Gourlay-francé, Catherine; Tusseau-vuillemin, Marie-hélène

2009-11-01

Metal bioavailability depends on the presence of organic ligands in the water and on the concentrations of competitive cations. The present study aims at testing whether the diffusive gradient in thin films technique (DGT) could be used to take into account Cd speciation and its consequences on bioavailability in a bioaccumulation model and whether the influences of the Ca concentration and temperature also should be considered. Four kinetic experiments were conducted on Gammarus pulex: a calibration of Cd turnover rates and of the DGT lability in mineral water, a study of the influence f ethylenediaminetetraacetic acid (EDTA) and humic acids (HA) on uptake rates, and two experiments testing the influence of the Ca concentrations and temperature on Cd uptake clearance rates (ku). In mineral water, where Cd was considered fully labile, the ku was 0.46 L g⁻¹ d⁻¹, and the depuration rate was 0.032 d⁻¹. The initial Cd influxes were lowered significantly by additions of 10 μg L⁻¹ of EDTA or 10 mg L⁻¹ of HA in the water but not at 5 mg L⁻¹HA, even if DGT measurements proved that Cd formed Cd-HA complexes in that treatment. Increasing Ca concentrations lowered ku values, and a competitive inhibition model between Ca and Cd fitted the data. A 30% enhancement of k, values was observed when the temperature was increased by 8°C, which appeared comparatively as a weak effect. Thus, taking into account the metal speciation and the influence of the Ca concentration should improve Cd bioaccumulation modeling in amphipods. In freshwater, where metal bioavailability is reduced by the presence of dissolved organic matter, forecasting Cd waterborne uptake using the labile concentrations should allow robust comparisons between laboratory and field studies.

The enemy of my enemy is my friend: intraguild predation between invaders and natives facilitates coexistence with shared invasive prey.

PubMed

MacNeil, Calum; Dick, Jaimie T A

2014-08-01

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. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

An approach for in situ studies of deep-sea amphipods and their microbial gut flora

NASA Astrophysics Data System (ADS)

Jannasch, H. W.; Cuhel, R. L.; Wirsen, C. O.; Taylor, C. D.

1980-10-01

A technique has been developed and field-tested for the trapping, feeding, and timed incubation of amphipods on the deep-sea floor. Data obtained from experiments using radiolabeled foodstuffs indicate that shifts within the labeled fractions of the major biological polymers make it possible to distinguish between the metabolism of the amphipods and that of their intestinal microflora.

Zoogeography of epigean freshwater Amphipoda (Crustacea) in Romania: fragmented distributions and wide altitudinal variability.

PubMed

Copilaș-Ciocianu, Denis; Grabowski, Michał; Pârvulescu, Lucian; Petrusek, Adam

2014-12-08

Inland epigean freshwater amphipods of Romania are diverse and abundant for this region has a favourable geographical position between the Balkans and the Black Sea. Excluding Ponto-Caspian species originating in brackish waters and freshwater subterranean taxa, there are 11 formally recognized epigean freshwater species recorded from this country. They belong to 3 genera, each representing a different family: Gammarus (Gammaridae, 8 species or species complexes), Niphargus (Niphargidae, 2 epigean species) and Synurella (Crangonyctidae, one species). Their large-scale distribution patterns nevertheless remain obscure due to insufficient data, consequently limiting biogeographical interpretations. We provide extensive new data with high resolution distribution maps, thus improving the knowledge of the ranges of these taxa. Gammarus species display substantial altitudinal variability and patchy, fragmented distribution patterns. They occur abundantly, particularly in springs and streams, from lowlands to sub-mountainous and mountainous regions. In the light of recent molecular research, we hypothesize that the complex geomorphological dynamics of the Carpathian region during the Late Tertiary probably contributed to their allopatric distribution pattern. Contrasting with Gammarus, the genera Niphargus and Synurella exhibit low altitudinal variability, broad ecological valences and overlapping distributions, being widespread throughout the lowlands. The current distribution of N. hrabei and N. valachicus seems to be linked to the extent of the Paratethys during the Early Pliocene or Pleistocene. We further discuss the taxonomic validity of two synonymized and one apparently undescribed taxon, and provide an updated pictorial identification key that includes all taxa and forms discussed in our study. The mosaic distribution of epigean freshwater amphipod species in Romania shows that this region is particularly suitable for phylo- and biogeographical analyses of this

Genome Reduction in Psychromonas Species within the Gut of an Amphipod from the Ocean's Deepest Point.

PubMed

Zhang, Weipeng; Tian, Ren-Mao; Sun, Jin; Bougouffa, Salim; Ding, Wei; Cai, Lin; Lan, Yi; Tong, Haoya; Li, Yongxin; Jamieson, Alan J; Bajic, Vladimir B; Drazen, Jeffrey C; Bartlett, Douglas; Qian, Pei-Yuan

2018-01-01

Amphipods are the dominant scavenging metazoan species in the Mariana Trench, the deepest known point in Earth's oceans. Here the gut microbiota of the amphipod Hirondellea gigas collected from the Challenger and Sirena Deeps of the Mariana Trench were investigated. The 11 amphipod individuals included for analyses were dominated by Psychromonas , of which a nearly complete genome was successfully recovered (designated CDP1). Compared with previously reported free-living Psychromonas strains, CDP1 has a highly reduced genome. Genome alignment showed deletion of the trimethylamine N -oxide (TMAO) reducing gene cluster in CDP1, suggesting that the "piezolyte" function of TMAO is more important than its function in respiration, which may lead to TMAO accumulation. In terms of nutrient utilization, the bacterium retains its central carbohydrate metabolism but lacks most of the extended carbohydrate utilization pathways, suggesting the confinement of Psychromonas to the host gut and sequestration from more variable environmental conditions. Moreover, CDP1 contains a complete formate hydrogenlyase complex, which might be involved in energy production. The genomic analyses imply that CDP1 may have developed adaptive strategies for a lifestyle within the gut of the hadal amphipod H. gigas. IMPORTANCE As a unique but poorly investigated habitat within marine ecosystems, hadal trenches have received interest in recent years. This study explores the gut microbial composition and function in hadal amphipods, which are among the dominant carrion feeders in hadal habitats. Further analyses of a dominant strain revealed genomic features that may contribute to its adaptation to the amphipod gut environment. Our findings provide new insights into animal-associated bacteria in the hadal biosphere.

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

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...

Independent colonization and extensive cryptic speciation of freshwater amphipods in the isolated groundwater springs of Australia's Great Artesian Basin.

PubMed

Murphy, Nicholas P; Adams, Mark; Austin, Andrew D

2009-01-01

The groundwater-dependent springs of the Great Artesian Basin (GAB) in arid inland Australia represent a unique and threatened ecosystem. These incredibly isolated springs support a diverse array of endemic flora and fauna. One of the common faunal groups in the GAB springs is the freshwater amphipods of the family Chiltoniidae. The morphological conservatism and taxonomic uncertainty associated with these amphipods has ensured their true biodiversity, phylogeographical history and evolutionary affinities have remained unknown. We have used mitochondrial DNA and allozyme data to unravel a complicated history of isolation, extinction and dispersal among spring amphipod populations across the GAB. The results provide evidence for multiple independent colonizations in the GAB springs, particularly within the Lake Eyre group of springs. The inclusion of a group of Western Australian (WA) stygobitic amphipods from populations up to 1500 km away found surprising evidence for a shared evolutionary history between stygobitic and GAB spring amphipods. Approximate dating of the diversity found between major clades suggests the majority of lineages originated in the late Miocene, around the time of the aridification of inland Australia. The large number of independent lineages and the close connection between GAB spring and WA stygobitic amphipods suggest that a significantly rich amphipod fauna existed in the much wetter environment that once existed in inland Australia. The results also provide evidence for a gross underestimation of the species diversity within the springs, with 12 putative species identified, a conclusion with significant implications for the ongoing conservation of the GAB springs.

Comparative mitogenomic analyses of three North American stygobiont amphipods of the genus Stygobromus (Crustacea: Amphipoda)

USGS Publications Warehouse

Aunins, Aaron W.; Nelms, David L.; Hobson, Christopher S.; King, Timothy L.

2016-01-01

The mitochondrial genomes of three North American stygobiont amphipods Stygobromus tenuis potomacus, S. foliatus and S. indentatus collected from Caroline County, VA, were sequenced using a shotgun sequencing approach on an Illumina NextSeq500 (Illumina Inc., San Diego, CA). All three mitogenomes displayed 13 protein-coding genes, 22 tRNAs and two rRNAs typical of metazoans. While S. tenuis and S. indentatusdisplayed identical gene orders similar to the pancrustacean ground pattern, S. foliatus displayed a transposition of the trnL2-cox2 genes to after atp8-atp6. In addition, a short atp8 gene, longer rrnL gene and large inverted repeat within the Control Region distinguished S. foliatus from S. tenuis potomacus and S. indentatus. Overall, it appears that gene order varies considerably among amphipods, and the addition of these Stygobromus mitogenomes to the existing sequenced amphipod mitogenomes will prove useful for characterizing evolutionary relationships among various amphipod taxa, as well as investigations of the evolutionary dynamics of the mitogenome in general.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fluoride toxicity and bioaccumulation in the invasive amphipod Dikerogammarus villosus (Sowinsky, 1894): a laboratory study.

PubMed

Gonzalo, Cristina; Camargo, Julio A; Masiero, Luciano; Casellato, Sandra

2010-11-01

The tolerance of the invasive amphipod Dikerogammarus villosus to fluoride (F⁻) toxicity was examined via laboratory experiments. 96-h LC₅₀ and 240-h NOEC values were estimated to be 5.8 and 0.95 mg F⁻/L, respectively. Average whole-body fluoride content in control amphipods was 27.6 μg F⁻/g dry weight, whereas in exposed amphipods it ranged from 3,637 to 16,994 μg F⁻/g dry weight. All these results indicate that D. villosus is a very sensitive species to fluoride toxicity. Overall it is concluded that the potential risk of invasion for D. villosus in either natural or polluted freshwater ecosystems, exhibiting relatively high fluoride levels (at least ten-fold higher than the average freshwater background level of 0.15 mg F⁻/L), must be low.

Genome Reduction in Psychromonas Species within the Gut of an Amphipod from the Ocean’s Deepest Point

PubMed Central

Zhang, Weipeng; Tian, Ren-Mao; Sun, Jin; Bougouffa, Salim; Ding, Wei; Cai, Lin; Lan, Yi; Tong, Haoya; Li, Yongxin; Jamieson, Alan J.; Bajic, Vladimir B.; Drazen, Jeffrey C.; Bartlett, Douglas

2018-01-01

ABSTRACT Amphipods are the dominant scavenging metazoan species in the Mariana Trench, the deepest known point in Earth’s oceans. Here the gut microbiota of the amphipod Hirondellea gigas collected from the Challenger and Sirena Deeps of the Mariana Trench were investigated. The 11 amphipod individuals included for analyses were dominated by Psychromonas, of which a nearly complete genome was successfully recovered (designated CDP1). Compared with previously reported free-living Psychromonas strains, CDP1 has a highly reduced genome. Genome alignment showed deletion of the trimethylamine N-oxide (TMAO) reducing gene cluster in CDP1, suggesting that the “piezolyte” function of TMAO is more important than its function in respiration, which may lead to TMAO accumulation. In terms of nutrient utilization, the bacterium retains its central carbohydrate metabolism but lacks most of the extended carbohydrate utilization pathways, suggesting the confinement of Psychromonas to the host gut and sequestration from more variable environmental conditions. Moreover, CDP1 contains a complete formate hydrogenlyase complex, which might be involved in energy production. The genomic analyses imply that CDP1 may have developed adaptive strategies for a lifestyle within the gut of the hadal amphipod H. gigas. IMPORTANCE As a unique but poorly investigated habitat within marine ecosystems, hadal trenches have received interest in recent years. This study explores the gut microbial composition and function in hadal amphipods, which are among the dominant carrion feeders in hadal habitats. Further analyses of a dominant strain revealed genomic features that may contribute to its adaptation to the amphipod gut environment. Our findings provide new insights into animal-associated bacteria in the hadal biosphere. PMID:29657971

A dataset on the species composition of amphipods (Crustacea) in a Mexican marine national park: Alacranes Reef, Yucatan

PubMed Central

Simões, Nuno; Pech, Daniel

2018-01-01

Abstract Background Alacranes Reef was declared as a National Marine Park in 1994. Since then, many efforts have been made to inventory its biodiversity. However, groups such as amphipods have been underestimated or not considered when benthic invertebrates were inventoried. Here we present a dataset that contributes to the knowledge of benthic amphipods (Crustacea, Peracarida) from the inner lagoon habitats from the Alacranes Reef National Park, the largest coral reef ecosystem in the Gulf of Mexico. The dataset contains information on records collected from 2009 to 2011. Data are available through Global Biodiversity Information Facility (GBIF). New information A total of 110 amphipod species distributed in 93 nominal species and 17 generic species, belonging to 71 genera, 33 families and three suborders are presented here. This information represents the first online dataset of amphipods from the Alacranes Reef National Park. The biological material is currently deposited in the crustacean collection from the regional unit of the National Autonomous University of Mexico located at Sisal, Yucatan, Mexico (UAS-Sisal). The biological material includes 588 data records with a total abundance of 6,551 organisms. The species inventory represents, until now, the richest fauna of benthic amphipods registered from any discrete coral reef ecosystem in Mexico. PMID:29416428

A dataset on the species composition of amphipods (Crustacea) in a Mexican marine national park: Alacranes Reef, Yucatan.

PubMed

Paz-Ríos, Carlos E; Simões, Nuno; Pech, Daniel

2018-01-01

Alacranes Reef was declared as a National Marine Park in 1994. Since then, many efforts have been made to inventory its biodiversity. However, groups such as amphipods have been underestimated or not considered when benthic invertebrates were inventoried. Here we present a dataset that contributes to the knowledge of benthic amphipods (Crustacea, Peracarida) from the inner lagoon habitats from the Alacranes Reef National Park, the largest coral reef ecosystem in the Gulf of Mexico. The dataset contains information on records collected from 2009 to 2011. Data are available through Global Biodiversity Information Facility (GBIF). A total of 110 amphipod species distributed in 93 nominal species and 17 generic species, belonging to 71 genera, 33 families and three suborders are presented here. This information represents the first online dataset of amphipods from the Alacranes Reef National Park. The biological material is currently deposited in the crustacean collection from the regional unit of the National Autonomous University of Mexico located at Sisal, Yucatan, Mexico (UAS-Sisal). The biological material includes 588 data records with a total abundance of 6,551 organisms. The species inventory represents, until now, the richest fauna of benthic amphipods registered from any discrete coral reef ecosystem in Mexico.

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.

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...

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

Conflict between co-occurring manipulative parasites? An experimental study of the joint influence of two acanthocephalan parasites on the behaviour of Gammarus pulex.

PubMed

Cezilly, F; Gregoire, A; Bertin, A

2000-06-01

When two parasite species are manipulators and have different definitive hosts, there is a potential for conflict between them. Selection may then exist for either avoiding hosts infected with conflicting parasites, or for hijacking, i.e. competitive processes to gain control of the intermediate host. The evidence for both phenomena depends largely on the study of the relative competitive abilities of parasites within their common intermediate host. We studied the effects of simultaneous infection by a fish acanthocephalan parasite, Pomphorhynchus laevis, and a bird acanthocephalan parasite, Polymorphus minutus, on the behaviour of their common intermediate host, the amphipod Gammarus pulex. We compared the reaction to light and vertical distribution of individuals infected with both parasites to those of individuals harbouring a single parasite species and uninfected ones under controlled conditions. Compared to uninfected gammarids that were photophobic and tended to remain at the bottom of the water column, P. laevis-infected gammarids were attracted to light, whereas P. minutus-infected individuals showed a modified vertical distribution and were swimming closer to the water surface. The effects of both P. laevis and P. minutus appeared to be dependent only on their presence, not on their intensity. Depending on the behavioural trait under study, however, the outcome of the antagonism between P. laevis and P. minutus differed. The vertical distribution of gammarids harbouring both parasites was half-way between those of P. laevis- and P. minutus-infected individuals, whereas P. laevis was able to induce altered reaction to light even in the presence of P. minutus. We discuss our results in relation to the occurrence of active avoidance or hijacking between conflicting manipulative parasites and provide some recommendations for future research.

Exposure to teflubenzuron negatively impacts exploratory behavior, learning and activity of juvenile European lobster (Homarus gammarus).

PubMed

Cresci, Alessandro; Samuelsen, Ole B; Durif, Caroline M F; Bjelland, Reidun M; Skiftesvik, Anne Berit; Browman, Howard I; Agnalt, Ann-Lisbeth

2018-09-30

Infestations with salmon lice, a parasitic copepod, is a major problem in the salmon farming industry. Teflubenzuron is an in-feed pharmaceutical applied to control lice outbreaks; the standard medication is 10 mg per kg fish per day for seven days. Surveys reveal that teflubenzuron accumulates and persists in the sediment around fish farms and causes deformities and mortality in juvenile European lobster (Homarus gammarus), a species commonly found in the vicinity of salmon farms in Norway. To date, there is no information on sub-lethal effects of teflubenzuron on, for example, behavior. We conducted an experiment to assess possible difference in the shelter seeking behavior of teflubenzuron-exposed (N = 19) vs. not exposed (N = 19) H. gammarus juveniles. The teflubenzuron-exposed juveniles had been given very low concentrations, 1.7 µg per pellet twice per week for 113 days prior to this experiment. The concentration of teflubenzuron was estimated to be less than 1 ng/g lobster when they were tested in the behavior experiment. Animals were placed in a lane with a shelter at one end. Once a lobster had found and entered the shelter, they were repeatedly displaced back to the opposite end of the lane, for a total of 3 repeated runs per animal. Three of the exposed juveniles failed to settle in the shelter, and the remaining teflubenzuron-exposed animals took significantly more time to explore the environment and to find and recognize shelter. Furthermore, exposed lobsters also exhibited slower walking speed compared to the controls. These results demonstrate that teflubenzuron significantly reduces exploratory behavior, learning and activity of juvenile H. gammarus. Thus, exposure to teflubenzuron could increase predation mortality of juvenile lobsters in the wild. Copyright © 2018. Published by Elsevier Inc.

Male but not female olfaction is crucial for intermolt mating in European lobsters (Homarus gammarus L.).

PubMed

Skog, Malin

2009-02-01

Chemical signals are common in most crustacean social interactions and are often perceived via chemosensory (olfactory) organs on the first antenna. Intermolt courtship behaviors and mating were investigated in size-matched pairs of intermolt European lobsters (Homarus gammarus) where the olfactory receptors of either the male or the female were lesioned with distilled water (olfactory ablation) or seawater (control). Matings or advanced male courtship behaviors (mounting and turning) were common in seawater controls and olfactory-ablated females. In contrast, when male olfaction was ablated with distilled water, there was not a single mating, and the only male courtship behaviors seen were a few very brief and unsuccessful mounting attempts. Individual females mated up to 5 times with different males, showing that previously inseminated females were still attractive to males. Thus, male but not female olfaction is crucial for intermolt mating in H. gammarus, indicating the presence of a female sex pheromone during the entire female molt cycle, not only at the time of molting. Female sex discrimination may be based on other cues from the male in combination with typical male behaviors.

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...

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.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of anthropogenic salinization on biological traits and community composition of stream macroinvertebrates.

PubMed

Szöcs, Eduard; Coring, Eckhard; Bäthe, Jürgen; Schäfer, Ralf B

2014-01-15

Salinization of rivers resulting from industrial discharge or road-deicing can adversely affect macroinvertebrates. Trait-based approaches are a promising tool in ecological monitoring and may perform better than taxonomy-based approaches. However only little is known how and which biological traits are affected by salinization. We investigated the effects of anthropogenic salinization on macroinvertebrate communities and biological traits in the Werra River, Germany and compared the taxonomic and trait response. We found a change in macroinvertebrate community and trait composition. Communities at saline sites were characterized by the three exotic species Gammarus tigrinus, Apocorophium lacustre and Potamopyrgus antipodarum. The frequencies of trait modalities long life cycle duration, respiration by gill, ovoviviparity, shredder and multivoltinism were statistically significantly increased at saline sites. The trait-based ordination resulted in a higher explained variance than the taxonomy-based ordination, indicating a better performance of the trait-based approach, resulting in a better discrimination between saline and non-saline sites. Our results are in general agreement with other studies from Europe, indicating a trait convergence for saline streams, being dominated by the traits ovoviviparity and multivoltinism. Three further traits (respiration by gill, life cycle duration and shredders) responded strongly to salinization, but this may primarily be attributed to the dominance of a single invasive species, G. tigrinus, at the saline sites in the Werra River. © 2013 Elsevier B.V. All rights reserved.

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...

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

PubMed

Nikitik, Christopher C S; Robinson, Andrew W

2003-09-01

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

Limited prevalence of gaffkaemia (Aerococcus viridans var. homari) isolated from wild-caught European lobsters Homarus gammarus in England and Wales.

PubMed

Stebbing, P D; Pond, M J; Peeler, E; Small, H J; Greenwood, S J; Verner-Jeffreys, D

2012-08-27

Gaffkaemia, caused by Aerococcus viridans var. homari, causes fatal infections in Homarus spp. (clawed lobsters). Despite its high economic significance to the lobster fisheries in the USA and northern Europe, data on its prevalence in captured and wild populations, particularly in Europe, is scarce. Following an outbreak of gaffkaemia in a European lobster holding facility in South Wales (UK), a base-line survey was conducted for gaffkaemia in wild populations of European lobster Homarus gammarus around the coast of England and Wales. In addition, isolates recovered from the original outbreak and the survey were typed using pulsed-field gel electrophoresis (PFGE) and compared with previously characterised isolates from the USA, UK and Canada. Locally caught H. gammarus were sampled at 30 sites from around the coast of England and Wales between March 2006 and October 2008. Results confirmed that the prevalence of gaffkaemia in populations of H. gammarus was low, with only 9 positive isolates recovered from 952 samples examined. PFGE analysis showed that the isolates from the outbreak investigation shared the same pulsotype as A. viridans var. homari isolates from the USA, Norway and Canada, as well as an isolate (NCIMB 1119) reportedly recovered from an outbreak of European lobsters in England in the 1960s. This confirms earlier studies that suggest virulent strains of A. viridans var. homari show very limited geographical or temporal genetic variation and were introduced into the UK with American lobsters H. americanus.

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

USGS Publications Warehouse

Ingersoll, Christopher G.; Wang, Ning; Hayward, Jeannie M. R.; Jones, John R.; Jones, Susan B.; Ireland, D. Scott

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

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.

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...

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.

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. © 2015 John Wiley & Sons Ltd.

Exploring the bacterial gut microbiota of supralittoral talitrid amphipods.

PubMed

Abdelrhman, Khaled F A; Bacci, Giovanni; Marras, Barbara; Nistri, Annamaria; Schintu, Marco; Ugolini, Alberto; Mengoni, Alessio

2017-01-01

Talitrid amphipods (sandhoppers and beach fleas) are typical of the supralittoral zone. They are known to thrive on stranded materials, including detrital marine angiosperms and macroalgae, as well as occasional dead animals. In this work, the gut microbiota of five species of talitrid amphipods (Talitrus saltator, Talorchestia ugolinii, Sardorchestia pelecaniformis, Orchestia montagui and Orchestia stephenseni) collected in Sardinia (Italy) has been investigated through: i) metabarcoding analysis of the amplified 16S rRNA V4 region; and ii) quantification of family 48 glycosyl hydrolase genes (GHF48), involved in cellulose degradation. Results indicate that, though talitrid gut biodiversity is not directly related to taxon or sampling locality, the animals' digestive tracts may host species-specific bacterial communities. In particular, gut microbiota of O. montagui, an inhabitant of Posidonia banquettes and macro-algae mat, showed the greatest differences in taxonomic composition and the highest proportion of GHF48 genes with respect to 16S rRNA genes. These results suggest that the different talitrid species may host species-specific bacterial communities whose function could partially reflect the different microhabitats and food preferences of their host. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Toxicity of sediment cores collected from the Ashtabula River in northeastern Ohio, USA, to the amphipod Hyalella azteca

USGS Publications Warehouse

Ingersoll, C.G.; Kemble, N.E.; Kunz, J.L.; Brumbaugh, W.G.; MacDonald, D.D.; Smorong, D.

2009-01-01

This study was conducted to support a Natural Resource Damage Assessment and Restoration project associated with the Ashtabula River in Ohio. The objective of the study was to evaluate the chemistry and toxicity of 50 sediment samples obtained from five cores collected from the Ashtabula River (10 samples/core, with each 10-cm-diameter core collected to a total depth of about 150 cm). Effects of chemicals of potential concern (COPCs) measured in the sediment samples were evaluated by measuring whole-sediment chemistry and whole-sediment toxicity in the sediment samples (including polycyclic aromatic hydrocarbons [PAHs], polychlorinated biphenyls [PCBs], organochlorine pesticides, and metals). Effects on the amphipod Hyalella azteca at the end of a 28-day sediment toxicity test were determined by comparing survival or length of amphipods in individual sediment samples in the cores to the range of responses of amphipods exposed to selected reference sediments that were also collected from the cores. Mean survival or length of amphipods was below the lower limit of the reference envelope in 56% of the sediment samples. Concentrations of total PCBs alone in some samples or concentrations of total PAHs alone in other samples were likely high enough to have caused the reduced survival or length of amphipods (i.e., concentrations of PAHs or PCBs exceeded mechanistically based and empirically based sediment quality guidelines). While elevated concentrations of ammonia in pore water may have contributed to the reduced length of amphipods, it is unlikely that the reduced length was caused solely by elevated ammonia (i.e., concentrations of ammonia were not significantly correlated with the concentrations of PCBs or PAHs and concentrations of ammonia were elevated both in the reference sediments and in the test sediments). Results of this study show that PAHs, PCBs, and ammonia are the primary COPCs that are likely causing or substantially contributing to the toxicity to

Transcriptome-based phylogeny of endemic Lake Baikal amphipod species flock: fast speciation accompanied by frequent episodes of positive selection.

PubMed

Naumenko, Sergey A; Logacheva, Maria D; Popova, Nina V; Klepikova, Anna V; Penin, Aleksey A; Bazykin, Georgii A; Etingova, Anna E; Mugue, Nikolai S; Kondrashov, Alexey S; Yampolsky, Lev Y

2017-01-01

Endemic species flocks inhabiting ancient lakes, oceanic islands and other long-lived isolated habitats are often interpreted as adaptive radiations. Yet molecular evidence for directional selection during species flocks radiation is scarce. Using partial transcriptomes of 64 species of Lake Baikal (Siberia, Russia) endemic amphipods and two nonendemic outgroups, we report a revised phylogeny of this species flock and analyse evidence for positive selection within the endemic lineages. We confirm two independent invasions of amphipods into Baikal and demonstrate that several morphological features of Baikal amphipods, such as body armour and reduction in appendages and sensory organs, evolved in several lineages in parallel. Radiation of Baikal amphipods has been characterized by short phylogenetic branches and frequent episodes of positive selection which tended to be more frequent in the early phase of the second invasion of amphipods into Baikal when the most intensive diversification occurred. Notably, signatures of positive selection are frequent in genes encoding mitochondrial membrane proteins with electron transfer chain and ATP synthesis functionality. In particular, subunits of both the membrane and substrate-level ATP synthases show evidence of positive selection in the plankton species Macrohectopus branickii, possibly indicating adaptation to active plankton lifestyle and to survival under conditions of low temperature and high hydrostatic pressures known to affect membranes functioning. Other functional categories represented among genes likely to be under positive selection include Ca-binding muscle-related proteins, possibly indicating adaptation to Ca-deficient low mineralization Baikal waters. © 2016 John Wiley & Sons Ltd.

STATUS OF THE AMPHIPOD DIPOREIA SPP. IN LAKE SUPERIOR, 1994-2000

EPA Science Inventory

The amphipod Diporeia spp. is the dominant component of the Great Lakes benthic macroinvertebrate fauna in terms of both numbers and biomass, and plays an important role in the ecosystem. The Great Lakes Water Quality Agreement calls for the use of Diporeia as an indicator of ec...

Ingestion and fragmentation of plastic carrier bags by the amphipod Orchestia gammarellus: Effects of plastic type and fouling load.

PubMed

Hodgson, D J; Bréchon, A L; Thompson, R C

2018-02-01

Inappropriate disposal of plastic debris has led to the contamination of marine habitats worldwide. This debris can be ingested by organisms; however, the extent to which chewing and gut transit modifies plastic debris is unclear. Detritivores, such as amphipods, ingest and shred natural organic matter and are fundamental to its breakdown. Here we examine ingestion and shredding of plastic carrier bags by Orchestia gammarellus. A laboratory experiment showed these amphipods shredded plastic carrier bags, generating numerous microplastic fragments (average diameter 488.59μm). The presence of a biofilm significantly increased the amount of shredding, but plastic type (conventional, degradable and biodegradable) had no effect. Subsequent field observations confirmed similar shredding occurred on the strandline. Rates of shredding will vary according to amphipod density; however, our data indicates that shredding by organisms could substantially accelerate the formation microplastics in the environment. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Behavioural alterations from exposure to Cu, phenanthrene, and Cu-phenanthrene mixtures: linking behaviour to acute toxic mechanisms in the aquatic amphipod, Hyalella azteca.

PubMed

Gauthier, Patrick T; Norwood, Warren P; Prepas, Ellie E; Pyle, Greg G

2016-01-01

Phenanthrene (PHE) and Cu are two contaminants commonly co-occurring in marine and freshwater environments. Mixtures of PHE and Cu have been reported to induce more-than-additive lethality in the amphipod, Hyalella azteca, a keystone aquatic invertebrate, yet little is understood regarding the interactive toxic mechanisms that mediate more-than-additive toxicity. Understanding the interactions among toxic mechanisms among Cu and PHE will allow for better predictive power in assessing the ecological risks of Cu-PHE mixtures in aquatic environments. Here we use behavioural impairment to help understand the toxic mechanisms of Cu, PHE, and Cu-PHE mixture toxicity in the aquatic amphipod crustacean, Hyalella azteca. Our principal objective was to link alterations in activity and ventilation with respiratory rates, oxidative stress, and neurotoxicity in adult H. azteca. Adult amphipods were used for all toxicity tests. Amphipods were tested at sublethal exposures of 91.8- and 195-μgL(-1) Cu and PHE, respectively, and a Cu-PHE mixture at the same concentrations for 24h. Neurotoxicity was measured as acetylcholinesterase (AChE) activity, where malathion was used as a positive control. Oxidative stress was measured as reactive oxygen species (ROS) production. Phenanthrene-exposed amphipods exhibited severe behavioural impairment, being hyperstimulated to the extent that they were incapable of coordinating muscle movements. In addition, respiration and AChE activity in PHE-exposed amphipods were increased and reduced by 51% and 23% respectively. However, ROS did not increase following exposure to phenanthrene. In contrast, Cu had no effect on amphipod behaviour, respiration or AChE activity, but did lead to an increase in ROS. However, co-exposure to Cu antagonized the PHE-induced reduction in ventilation and negated any increase in respiration. The results suggest that PHE acts like an organophosphate pesticide (e.g., malathion) in H. azteca following 24h sublethal

PHOTOINDUCED TOXICITY OF PAHS AND ALKYLATED PAHS TO A MARINE INFAUNAL AMPHIPOD (RHEPOXYNIUS ABRONIUS)

EPA Science Inventory

The marine infaunal amphipod Rhepoxynius abronius was exposed in standard 10-day toxicity tests to sediments contaminated with parent or alkylated PAHs. After exposures, mortalities (LC50 values) and the ability to rebury in control sediment (EC50 values) were determined. Survivo...

Some like it hot: factors impacting thermal preferences of two Ponto-Caspian amphipods Dikerogammarus villosus (Sovinsky, 1894) and Dikerogammarus haemobaphes (Eichwald, 1841).

PubMed

Rachalewski, Michał; Kobak, Jarosław; Szczerkowska-Majchrzak, Eliza; Bącela-Spychalska, Karolina

2018-01-01

Temperature is a crucial factor determining biology and ecology of poikilothermic animals. It often constitutes an important barrier for invasive species originating from different climate zones but, on the other hand, may facilitate the invasion process of animals with wide thermal preferences and high resistance to extreme temperatures. In our experimental study, we investigated the thermal behaviour of two Ponto-Caspian amphipod crustaceans- Dikerogammarus villosus and Dikerogammarus haemobaphes . Both species are known to live under a wide range of thermal conditions which may promote their invasion. Moreover, both these amphipods are hosts for microsporidian parasites which co-evolved with them within the Ponto-Caspian region and spread in European waters. As the presence of a parasite may influence the thermal preferences of its host, we expected to observe behavioural changes in infected individuals of the studied amphipods leading to (1) behavioural fever (selecting a warmer habitat) or (2) anapyrexia (selecting a colder habitat). The experiment ( N  = 20) was carried out for 30 min in a 100 cm. 20 cm from boths sides were not avaliable for amphipods long thermal gradient (0-40 °C), using 30 randomly selected adult amphipod individuals of one species. At the end of each trial, we checked the position of amphipods along the gradient and determined their sex and infection status (uninfected or infected by one of microsporidium species). D. villosus was infected with Cucumispora dikerogammari whereas D. haemobaphes was a host for C. dikerogammari , Dictyocoela muelleri or D. berillonum . Thermal preferences of amphipods depended on their species and sex. Females of D. villosus preferred warmer microhabitats (often much above 30 °C) than conspecific males and females of D. haemobaphes , whereas no significant differences were found among males of both species and both sexes of D. haemobaphes . Moreover, infected males of D. villosus stayed in

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

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

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 metalmore » is an important constituent in municipal wastes discharged into southern California marine waters.« less

Aspartic cathepsin D endopeptidase contributes to extracellular digestion in clawed lobsters Homarus americanus and Homarus gammarus.

PubMed

Rojo, Liliana; Muhlia-Almazan, Adriana; Saborowski, Reinhard; García-Carreño, Fernando

2010-11-01

Acid digestive proteinases were studied in the gastric fluids of two species of clawed lobster (Homarus americanus and Homarus gammarus). An active protein was identified in both species as aspartic proteinase by specific inhibition with pepstatin A. It was confirmed as cathepsin D by mass mapping, N-terminal, and full-length cDNA sequencing. Both lobster species transcribed two cathepsin D mRNAs: cathepsin D1 and cathepsin D2. Cathepsin D1 mRNA was detected only in the midgut gland, suggesting its function as a digestive enzyme. Cathepsin D2 mRNA was found in the midgut gland, gonads, and muscle. The deduced amino acid sequence of cathepsin D1 and cathepsin D2 possesses two catalytic DTG active-site motifs, the hallmark of aspartic proteinases. The putatively active cathepsin D1 has a molecular mass of 36.4 kDa and a calculated pI of 4.14 and possesses three potential glycosylation sites. The sequences showed highest similarities with cathepsin D from insects but also with another crustacean cathepsin D. Cathepsin D1 transcripts were quantified during a starvation period using real-time qPCR. In H. americanus, 15 days of starvation did not cause significant changes, but subsequent feeding caused a 2.5-fold increase. In H. gammarus, starvation caused a 40% reduction in cathepsin D1 mRNA, and no effect was observed with subsequent feeding.

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 ...

Acute and chronic toxicity of aluminum to a unionid mussel (Lampsilis siliquoidea) and an amphipod (Hyalella azteca) in water‐only exposures

USGS Publications Warehouse

Wang, Ning; Ivey, Chris D.; Brunson, Eric L.; Cleveland, Danielle; Ingersoll, Christopher G.; Stubblefield, William A.; Cardwell, Allison S.

2018-01-01

The US Environmental Protection Agency (USEPA) is reviewing the protectiveness of the national ambient water quality criteria (WQC) for aluminum (Al) and compiling a toxicity data set to update the WQC. Freshwater mussels are one of the most imperiled groups of animals in the world, but little is known about their sensitivity to Al. The objective of the present study was to evaluate acute 96‐h and chronic 28‐d toxicity of Al to a unionid mussel (Lampsilis siliquoidea) and a commonly tested amphipod (Hyalella azteca) at a pH of 6 and water hardness of 100 mg/L as CaCO3. The acute 50% effect concentration (EC50) for survival of both species was >6200 μg total Al/L. The EC50 was greater than all acute values in the USEPA acute Al data set for freshwater species at a pH range of 5.0 to <6.5 and hardness normalized to 100 mg/L, indicating that the mussel and amphipod were insensitive to Al in acute exposures. The chronic 20% effect concentration (EC20) based on dry weight was 163 μg total Al/L for the mussel and 409 μg total Al/L for the amphipod. Addition of the EC20s to the USEPA chronic Al data set for pH 5.0 to <6.5 would rank the mussel (L. siliquoidea) as the fourth most sensitive species and the amphipod (H. azteca) as the fifth most sensitive species, indicating the 2 species were sensitive to Al in chronic exposures. The USEPA‐proposed acute and chronic WQC for Al would adequately protect the mussel and amphipod tested; however, inclusion of the chronic data from the present study and recalculation of the chronic criterion would likely lower the proposed chronic criterion. 

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.

Genotoxic effects of the water-soluble fraction of heavy oil in the brackish/freshwater amphipod Quadrivisio aff. lutzi (Gammaridea) as assessed using the comet assay.

PubMed

Weber, Laura; Carvalho, Ligia; Sá, Natália; Silva, Viviane; Beraldini, Nathalia; Souza, Valderes; Conceição, Moisés

2013-05-01

Amphipod crustaceans have been widely used as invertebrate models in ecotoxicology due to their importance in the food chain. However, few studies have evaluated the genotoxic effects of pollutants in this model using the comet assay. The main obstacle to using amphipods in the comet assay is the difficulty in obtaining enough blood cells from a single individual. In this study, we evaluated the genotoxic effects of the water-soluble fraction (WSF) of heavy oil on the brackish/freshwater amphipod Quadrivisio aff. lutzi, which is common in the coastal lagoons of southeastern Brazil, using hemocytes obtained from single amphipods (without pooling) after optimizing hemolymph extraction. The comet assay revealed significantly higher DNA damage levels (2- to 6-fold higher) in treated amphipods compared to untreated ones with a sublethal concentration of 17.6 % of the WSF within 72 h of treatment. Two independent experiments confirmed an "up and down" pattern of DNA damage, measured as the % of DNA contained in the tail of the comets. Elevations in DNA damage levels were observed at the 6 and 48 h time points, while very low levels of DNA damage were observed at the 24 and 72 h time points. Furthermore, the comet assay revealed gender variability in the levels of DNA damage after short-term exposure.

Combined effects of predator cues and competition define habitat choice and food consumption of amphipod mesograzers.

PubMed

Beermann, Jan; Boos, Karin; Gutow, Lars; Boersma, Maarten; Peralta, Ana Carolina

2018-03-01

Predation has direct impact on prey populations by reducing prey abundance. In addition, predator presence alone can also have non-consumptive effects on prey species, potentially influencing their interspecific interactions and thus the structure of entire assemblages. The performance of potential prey species may, therefore, depend on both the presence of predators and competitors. We studied habitat use and food consumption of a marine mesograzer, the amphipod Echinogammarus marinus, in the presence/absence of a fish mesopredator and/or an amphipod competitor. The presence of the predator affected both habitat choice and food consumption of the grazer, indicating a trade-off between the use of predator-free space and food acquisition. Without the predator, E. marinus were distributed equally over different microhabitats, whereas in the presence of the predator, most individuals chose a sheltered microhabitat and reduced their food consumption. Furthermore, habitat choice of the amphipods changed in the presence of interspecific competitors, also resulting in reduced feeding rates. The performance of E. marinus is apparently driven by trait-mediated direct and indirect effects caused by the interplay of predator avoidance and competition. This highlights the importance of potential non-consumptive impacts of predators on their prey organisms. The flexible responses of small invertebrate consumers to the combined effects of predation and competition potentially lead to changes in the structure of coastal ecosystems and the multiple species interactions therein.

Effect of an insect juvenile hormone analogue, Fenoxycarb on development and oxygen uptake by larval lobsters Homarus gammarus (L.).

PubMed

Arnold, Katie E; Wells, Colin; Spicer, John I

2009-04-01

Little attention has been focused on the effect of anthropogenic compounds that disrupt the endocrine systems in crustaceans. Consequently, this study investigated the effects of the juvenile hormone analogue (JHA), Fenoxycarb on selected physiological and developmental processes of the zoeal stages in the European lobster, Homarus gammarus. Chronic exposure to Fenoxycarb (50microg L(-1)) resulted in a significant (p < 0.05) reduction in moult frequency and size at moult. Fenoxycarb exposure extended zoeal duration between zoea I to II (p<0.05) and resulted in total inhibition of the moult from zoea II to III. Significantly greater rates of O2 uptake were observed in Fenoxycarb-exposed larvae in comparison with controls (p<0.05). All rates of O2 uptake decreased significantly between 7 and 12d of exposure (p<0.05). At 12d, exposure to the solvent control no longer influenced rates of O2 uptake, but it was not possible to attribute increased O2 uptake to Fenoxycarb exposure directly, as treated individuals did not moult beyond zoea III. The low exposure concentrations of Fenoxycarb, comparable to those used in plant protection, resulted in endocrine disrupted responses in H. gammarus (albeit with little clear, demonstrable effect on metabolism) a finding that could have important ecological and commercial implications.

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...

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.

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...

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

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.

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. Copyright © 2015 Elsevier Inc. All rights reserved.

Sediment toxicity testing with the amphipod Ampelisca abdita in Calcasieu Estuary, Louisiana

USGS Publications Warehouse

Redmond, M.S.; Crocker, P.A.; McKenna, K.M.; Petrocelli, E.A.; Scott, K.J.; Demas, C.R.

1996-01-01

Discharges from chemical and petrochemical manufacturing facilities have contaminated portions of Louisiana's Calcasieu River estuary with a variety of organic and inorganic contaminants. As part of a special study, sediment toxicity testing was conducted to assess potential impact to the benthic community. Ten-day flow-through sediment toxicity tests with the amphipod Ampelisca abdita revealed significant toxicity at 68% (26 of 38) of the stations tested. A. abdita mortality was highest in the effluent-dominated bayous, which are tributaries to the Calcasieu River. Mortality was correlated with total heavy metal and total organic compound concentrations in the sediments. Ancillary experiments showed that sediment interstitial water salinity as low as 2.5 o/o-o did not significantly affect A. abdita's, response in the flow-through system; sediment storage for 7 weeks at 4??C did not significantly affect toxicity. Sediment toxicity to A. abdita was more prevalent than receiving water toxicity using three short-term chronic bioassays. Results suggest that toxicity testing using this amphipod is a valuable tool when assessing sediments containing complex contaminant mixtures and for assessing effects of pollutant loading over time. In conjunction with chemical analyses, the testing indicated that the effluent-dominated, brackish bayous (Bayou d'Inde and Bayou Verdine) were the portions of the estuary most impacted by toxicity.

Potential for parasite-induced biases in aquatic invertebrate population studies

USGS Publications Warehouse

Fisher, Justin D.L.; Mushet, David M.; Stockwell, Craig A.

2014-01-01

Recent studies highlight the need to include estimates of detection/capture probability in population studies. This need is particularly important in studies where detection and/or capture probability is influenced by parasite-induced behavioral alterations. We assessed potential biases associated with sampling a population of the amphipod Gammarus lacustris in the presence of Polymorphus spp. acanthocephalan parasites shown to increase positive phototaxis in their amphipod hosts. We trapped G. lacustris at two water depths (benthic and surface) and compared number of captures and number of parasitized individuals at each depth. While we captured the greatest number of G. lacustris individuals in benthic traps, parasitized individuals were captured most often in surface traps. These results reflect the phototaxic movement of infected individuals from benthic locations to sunlit surface waters. We then explored the influence of varying infection rates on a simulated population held at a constant level of abundance. Simulations resulted in increasingly biased abundance estimates as infection rates increased. Our results highlight the need to consider parasite-induced biases when quantifying detection and/or capture probability in studies of aquatic invertebrate populations.

Predation by the isopod Saduria entomon on the amphipods Monoporeia affinis and Pontoporeia femorata: experiments on prey vulnerability.

PubMed

Hill, Cathy; Elmgren, Ragnar

1992-08-01

Predation by Saduria entomon on the depositfeeding amphipods Monoporeia (=Pontoporeia) affinis and Pontoporeia femorata was studied in laboratory experiments. Prey vulnerabilities were compared in singleprey treatments and in mixed-prey treatments, where the proportions of the two species were varied at one total density. In a pilot experiment, P. femorata was the more vulnerable prey, both in single-prey and mixed-prey treatments. In later experiments, the amphipod species were equally vulnerable in single-prey treatments, while in mixed-prey treatments Saduria preyed preferentially on M. affinis, even when this prey was rare, i.e. it did not "switch". We suggest that the different result in the later experiments may have been due to a change in the search mode of the isopods.

Benthic amphipods (Amphipoda: Gammaridea and Corophiidea) from the Mexican southeast sector of the Gulf of Mexico: checklist, new records and zoogeographic comments.

PubMed

Paz-Ríos, Carlos E; Ardisson, Pedro-Luis

2013-01-01

The southeast region of the Gulf of Mexico is considered to be biologically important, because it is a connection and transition zone between the Caribbean and the Gulf of Mexico, harboring great marine biodiversity. Nevertheless, benthic amphipods have been poorly studied in the Mexican southeast sector of the Gulf of Mexico with few studies listing species. The aim of this study is to provide an update checklist of species for the Mexican southeast sector (based on literature review and records from the present study) as well as a brief zoogeographical analysis for the Gulf of Mexico amphipod fauna, putting them in context with the fauna on the tropical western Atlantic. Fifty-five species were listed for the Mexican southeast sector; 36 of them showed a geographical extension to the Yucatan continental shelf representing 23 new records for the Mexican southeast sector, nine for the southeast region and four for the Gulf of Mexico. Based on the zoogeographical analysis, there is support of the application of Carolinian and Caribbean zoogeographic provinces to amphipods in the Gulf of Mexico.

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...

Studying the effect of CO2-induced acidification on sediment toxicity using acute amphipod toxicity test.

PubMed

Basallote, M Dolores; De Orte, Manoela R; DelValls, T Ángel; Riba, Inmaculada

2014-01-01

Carbon capture and storage is increasingly being considered one of the most efficient approaches to mitigate the increase of CO2 in the atmosphere associated with anthropogenic emissions. However, the environmental effects of potential CO2 leaks remain largely unknown. The amphipod Ampelisca brevicornis was exposed to environmental sediments collected in different areas of the Gulf of Cádiz and subjected to several pH treatments to study the effects of CO2-induced acidification on sediment toxicity. After 10 days of exposure, the results obtained indicated that high lethal effects were associated with the lowest pH treatments, except for the Ría of Huelva sediment test. The mobility of metals from sediment to the overlying seawater was correlated to a pH decrease. The data obtained revealed that CO2-related acidification would lead to lethal effects on amphipods as well as the mobility of metals, which could increase sediment toxicity.

Causes of highway road dust toxicity to an estuarine amphipod: Evaluating the effects of nicotine.

PubMed

Hiki, Kyoshiro; Nakajima, Fumiyuki; Tobino, Tomohiro

2017-02-01

Urban road dust can potentially have adverse effects on ecosystems if it is discharged into receiving waters. This study investigated the causes of highway road dust toxicity by performing sediment toxicity identification evaluation (TIE) tests with an estuarine amphipod, Grandidierella japonica. In addition to metals and polycyclic aromatic hydrocarbons, which are traditionally considered to be the major toxicants in road runoff, we focused on dissolved nicotine as a causative toxicant. The sediment TIE results suggested that organic contaminants contributed to the majority of toxicity, and that the contribution of unionized nicotine to the toxicity was the highest among the chemicals considered. However, additional mortality tests with 48-h pulsed nicotine exposure demonstrated that exposure to nicotine at the same concentration as the baseline level in TIE tests did not cause significant 10-day amphipod mortality. Thus, the road dust toxicity could not be explained only by unionized nicotine, thereby suggesting contributions from joint effects of the measured toxicants and the presence of other unmeasured factors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ontogenetic variability in the feeding behavior of a marine amphipod in response to ocean acidification.

PubMed

Benítez, Samanta; Duarte, Cristian; López, Jorge; Manríquez, Patricio H; Navarro, Jorge M; Bonta, Cesar C; Torres, Rodrigo; Quijón, Pedro A

2016-11-15

Global stressors like ocean acidification (OA) are expected to influence the quality or palatability of primary producers like algae. Such changes can trigger a response on algal consumers' feeding strategies, and this response may not necessarily be the same for the consumers during the ontogeny. We used a mesocosm's system to expose algae to current and projected OA conditions (390 and 1000ppm, respectively) and then compared the feeding behavior and absorption efficiency of juvenile and adult stages of the amphipod Orchestoidea tuberculata. Specifically, we measured consumption rates (with and without a choice) and absorption efficiency on algae exposed and not exposed to OA. Our results show that OA affect the amphipod's consumption and feeding preferences, and that these effects were related with the analyzed ontogenetic stage (juveniles versus adults). These results support the existence of an ontogenetic change in the response of this species and others similar marine invertebrates to OA, which highlight the need to incorporate different life stages in the study of OA or others global stressors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adaptation of Gammarus pulex to agricultural insecticide contamination in streams.

PubMed

Shahid, Naeem; Becker, Jeremias Martin; Krauss, Martin; Brack, Werner; Liess, Matthias

2018-04-15

Exposure to pesticides affects non-target aquatic communities, with substantial consequences on ecosystem services. Adaptation of exposed populations may reduce the effects of pesticides. However, it is not known under which conditions adaptation occurs when only a low toxic pressure from pesticides is present. Here, we show that Gammarus pulex, a dominant macroinvertebrate species in many agricultural streams, acquires increased tolerance to pesticides when recolonization from non-contaminated refuge areas is low. Populations in the field that were exposed to pesticides at concentrations several orders of magnitude below considerable acute effects showed almost 3-fold higher tolerance to the neonicotinoid insecticide clothianidin (mean EC 50 218μgL -1 ) compared with non-exposed populations (mean EC 50 81μgL -1 ). This tolerance of exposed populations increased from 2- to 4-fold with increasing distance to the next refuge area (0 to 10km). We conclude that the development of tolerance for non-target species may occur at very low concentrations, much below those affecting sensitive test organisms and also lower than those predicted to be safe by governmental risk assessment frameworks. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

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.

Effects of Sublethal Cadmium Exposure on Antipredator Behavioural and Antitoxic Responses in the Invasive Amphipod Dikerogammarus villosus

PubMed Central

Sornom, Pascal; Gismondi, Eric; Vellinger, Céline; Devin, Simon; Férard, Jean-François; Beisel, Jean-Nicolas

2012-01-01

Amphipods are recognised as an important component of freshwater ecosystems and are frequently used as an ecotoxicological test species. Despite this double interest, there is still a lack of information concerning toxic impacts on ecologically relevant behaviours. The present study investigated the influence of cadmium (Cd), a non-essential heavy metal, on both antipredator behaviours and antitoxic responses in the invasive amphipod Dikerogammarus villosus under laboratory conditions. Amphipod behaviour (i.e. refuge use, aggregation with conspecifics, exploration and mobility) was recorded following a 4-min test-exposure to 500 µg Cd/L with or without a 24-h Cd pre-exposure and in the presence or absence of a high perceived risk of predation (i.e. water scented by fish predators and injured conspecifics). Following behavioural tests, malondialdehyde (MDA) levels, a biomarker for toxic effect, and energy reserves (i.e. lipid and glycogen contents) were assessed. Cd exposures induced (1) cell damage reflected by high MDA levels, (2) erratic behaviour quantified by decreasing refuge use and exploration, and increasing mobility, and (3) a depletion in energy reserves. No significant differences were observed between 4-min test-exposed and 24-h pre-exposed individuals. Gammarids exposed to Cd had a disturbed perception of the alarm stimuli, reflected by increased time spent outside of refuges and higher mobility compared to gammarids exposed to unpolluted water. Our results suggest that Cd exposure rapidly disrupts the normal behavioural responses of gammarids to alarm substances and alters predator-avoidance strategies, which could have potential impacts on aquatic communities. PMID:22879985

Molecular adaptation in the world's deepest-living animal: Insights from transcriptome sequencing of the hadal amphipod Hirondellea gigas.

PubMed

Lan, Yi; Sun, Jin; Tian, Renmao; Bartlett, Douglas H; Li, Runsheng; Wong, Yue Him; Zhang, Weipeng; Qiu, Jian-Wen; Xu, Ting; He, Li-Sheng; Tabata, Harry G; Qian, Pei-Yuan

2017-07-01

The Challenger Deep in the Mariana Trench is the deepest point in the oceans of our planet. Understanding how animals adapt to this harsh environment characterized by high hydrostatic pressure, food limitation, dark and cold is of great scientific interest. Of the animals dwelling in the Challenger Deep, amphipods have been captured using baited traps. In this study, we sequenced the transcriptome of the amphipod Hirondellea gigas collected at a depth of 10,929 m from the East Pond of the Challenger Deep. Assembly of these sequences resulted in 133,041 contigs and 22,046 translated proteins. Functional annotation of these contigs was made using the go and kegg databases. Comparison of these translated proteins with those of four shallow-water amphipods revealed 10,731 gene families, of which 5659 were single-copy orthologs. Base substitution analysis on these single-copy orthologs showed that 62 genes are positively selected in H. gigas, including genes related to β-alanine biosynthesis, energy metabolism and genetic information processing. For multiple-copy orthologous genes, gene family expansion analysis revealed that cold-inducible proteins (i.e., transcription factors II A and transcription elongation factor 1) as well as zinc finger domains are expanded in H. gigas. Overall, our results indicate that genetic adaptation to the hadal environment by H. gigas may be mediated by both gene family expansion and amino acid substitutions of specific proteins. © 2017 John Wiley & Sons Ltd.

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...

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

Toxicological effects of fungicide mixtures on the amphipod Austrochiltonia subtenuis.

PubMed

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

2017-10-01

Approaches to assess the toxicity of mixtures often use predictive models with acute mortality as an endpoint at relatively high concentrations. However, these approaches do not reflect realistic situations where organisms could be exposed to chemical mixtures over long periods at low concentrations at which no significant mortalities occur. The present study investigated chronic effects of 2 common fungicides, Filan® (active ingredient [a.i]) boscalid) and Systhane™ (a.i. myclobutanil), on the amphipod Austrochiltonia subtenuis at environmentally relevant concentrations under laboratory conditions. Sexually mature amphipods were exposed singly and in combination to Filan (1, 10, and 40 μg a.i./L) and Systhane (3 μg a.i./L) over 28 d. Survival, growth, a wide range of reproduction endpoints, and glutathione-S-transferase (GST) activity were measured at the end of the experiment. Both fungicides had significant independent effects on male growth, sex ratio, and juvenile size. Filan mainly affected female growth and the number of embryos per gravid female, whereas Systhane mainly affected the time for females to become gravid. The combined effects of these fungicides on numbers of gravid females and juveniles were antagonistic, causing a 61% reduction in the number of gravid females and a 77% reduction in the number of juveniles produced at the highest concentrations (40 μg a.i./L of boscalid and 3 μg a.i./L of myclobutanil) compared with the controls. There were no significant effects on survival or GST activity. The present study demonstrated that the effects of mixtures were endpoint dependent and that using a variety of endpoints should be considered for a comprehensive understanding of mixture effects. Also, chronic studies are more informative than acute studies for environmentally relevant fungicide concentrations. Environ Toxicol Chem 2017;36:2651-2659. © 2017 SETAC. © 2017 SETAC.

Development of an acute toxicity test with the tropical marine amphipod Parhyale hawaiensis.

PubMed

Artal, Mariana Coletty; Dos Santos, Amanda; Henry, Theodore Burdick; Umbuzeiro, Gisela de Aragão

2018-03-01

There is a lack of suitable tropical marine species for ecotoxicity tests. An attractive model organism for ecotoxicology is the marine amphipod Parhyale hawaiensis, which is already a model for genetic and developmental studies. This species is widespread, can tolerate changes in salinity, is easy to handle and is representative of circumtropical regions. The aim of this work was to describe standardized procedures for laboratory husbandry, define conditions for acute toxicity tests, and to provide acute toxicity test results for some reference toxicants. Culturing conditions for the organism in the laboratory were established in reconstituted seawater (30 ± 2 salinity), 24 ± 2 °C, photoperiod 12/12 h light/dark. Acute toxicity test procedures were developed for 96 h-exposure time, and organisms at ages <7 days. The miniaturized version of the test, based on 96-well microplates and 200 µL of exposure media provided consistent results compared to larger exposure volumes (80-mL vials protocol). Acute toxicity of Ag, Cd, Cu, Zn and ammonia determined for P. hawaiensis were consistent to previous results for other marine amphipods. We conclude that P. hawaiensis can be successfully cultured in standardized conditions and be effectively used in acute toxicity testing. Further development and use of this model will enable standardized and reproducible ecotoxicology investigations in understudied and vulnerable tropical marine ecosystems.

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...

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...

EVALUATING THE ECOLOGICAL SIGNIFICANCE OF LABORATORY RESPONSE DATA TO PREDICT POPULATION-LEVEL EFFECTS FOR THE ESTUARINE AMPHIPOD, AMPILISCA ABDITA

EPA Science Inventory

Ten-day acute mortality of the benthic amphipod Ampelisca abdita is used in a number of regulatory, research, and monitoring programs to evaluate chemical contamination of marine sediments. Although this endpoint has proven to be valuable for characterizing the relative toxicitie...

Vitellogenin-like proteins in the freshwater amphipod Gammarus fossarum (Koch, 1835): functional characterization throughout reproductive process, potential for use as an indicator of oocyte quality and endocrine disruption biomarker in males.

PubMed

Jubeaux, Guillaume; Simon, Romain; Salvador, Arnaud; Quéau, Hervé; Chaumot, Arnaud; Geffard, Olivier

2012-05-15

This work focused on the validation of biological specificity of the quantitative LC-MS/MS assay by checking the natural variability of Vg levels during the reproductive cycle in Gammarus fossarum (i.e., including oogenesis and embryogenesis). Laboratory tests were performed for 21 days under controlled conditions to assess Vg changes in male and female gammarids after exposure to chemical stress. Females were exposed to two crustacean hormones, 20-hydroxyecdysone (0.01, 1 and 100 μg L⁻¹) and methyl-farnesoate (0.01, 1 and 100 μg L⁻¹). No effect was recorded for 20-hydroxyecdysone, whereas in females exposed to methyl-farnesoate a deleterious impact on Vg production was observed. Males were exposed to crustacean hormones 20-hydroxyecdysone (0.01, 1 and 100 μg L⁻¹) and methyl-farnesoate (0.01, 1 and 100 μg L⁻¹), the insecticide methoxyfenozide (0.001, 0.1 and 10 μg L⁻¹), the fungicide propiconazole (0.001, 0.1, 10 and 1000 μg L⁻¹), and the pharmaceutical products benzophenone, carbamazepine, cyproterone, and R-propranolol (0.001, 0.1, 10 and 1000 μg L⁻¹). Induction of Vg synthesis was recorded in males exposed to cyproterone, methoxyfenozide, methyl-farnesoate, and propiconazole. Finally, we validated the function of the ILIPGVGK peptide used to track vitellogenin in G. fossarum across reproductive processes (vitellogenesis and embryogenesis), and results confirmed the energy reserve role of Vg during embryo development. We show that oocyte surface measurement is directly related to Vg levels in the oocyte, constituting a reliable indicator of egg quality in G. fossarum. Consequently, it could be used as a reliable tool for biomonitoring programs. We recorded induction of Vg in male G. fossarum; however, the possible use of this tool as a specific biomarker of exposure to endocrine disruption should be confirmed in further studies. Copyright © 2012 Elsevier B.V. All rights reserved.

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. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

Influence of bromide on the performance of the amphipod Hyalella azteca in reconstituted waters

USGS Publications Warehouse

Ivey, Chris D.; Ingersoll, Christopher G.

2016-01-01

Poor performance of the amphipod Hyalella azteca has been observed in exposures using reconstituted waters. Previous studies have reported success in H. azteca water-only exposures with the addition of relatively high concentrations of bromide. The present study evaluated the influence of lower environmentally representative concentrations of bromide on the response ofH. azteca in 42-d water-only exposures. Improved performance of H. azteca was observed in reconstituted waters with >0.02 mg Br/L.

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; 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.

Assessment of the environmental impacts of ocean acidification (OA) and carbon capture and storage (CCS) leaks using the amphipod Hyale youngi.

PubMed

Goulding, T A; De Orte, M R; Szalaj, D; Basallote, M D; DelValls, T A; Cesar, A

2017-05-01

This study aims to ascertain the effects of CO 2 induced water acidification and leaks from Carbon Capture and Storage activities on the South American amphipod Hyale youngi. A 10-day acute toxicity test was performed using sediments from two sites located inside the Santos Estuarine System. They were subjected to five pH treatments (8.1, 7.6, 7.0, 6.5, and 6.0). Metals (Cd, Cu, Cr, Pb, Ni and Zn) and the metalloid As were analyzed to determine the influence of their acidification-related mobility on the amphipods mortality. The results showed that mortality becomes significant when compared to control in pH 6.5 in the Canal de Piaçaguera sediment (contaminated) and at pH 6.0 in Ilha das Palmas sediment (reference).

The diversity and antibiotic properties of actinobacteria associated with endemic deepwater amphipods of Lake Baikal.

PubMed

Protasov, Eugenii S; Axenov-Gribanov, Denis V; Rebets, Yuriy V; Voytsekhovskaya, Irina V; Tokovenko, Bogdan T; Shatilina, Zhanna M; Luzhetskyy, Andriy N; Timofeyev, Maxim A

2017-12-01

The emergence of pathogenic bacteria resistant to antibiotics increases the need for discovery of new effective antimicrobials. Unique habitats such as marine deposits, wetlands and caves or unexplored biological communities are promising sources for the isolation of actinobacteria, which are among the major antibiotic producers. The present study aimed at examining cultivated actinobacteria strains associated with endemic Lake Baikal deepwater amphipods and estimating their antibiotic activity. We isolated 42 actinobacterial strains from crustaceans belonging to Ommatogammarus albinus and Ommatogammarus flavus. To our knowledge, this is the first report describing the isolation and initial characterization of representatives of Micromonospora and Pseudonocardia genera from Baikal deepwater invertebrates. Also, as expected, representatives of the genus Streptomyces were the dominant group among the isolated species. Some correlations could be observed between the number of actinobacterial isolates, the depth of sampling and the source of the strains. Nevertheless, >70% of isolated strains demonstrated antifungal activity. The dereplication analysis of extract of one of the isolated strains resulted in annotation of several known compounds that can help to explain the observed biological activities. The characteristics of ecological niche and lifestyle of deepwater amphipods suggests that the observed associations between crustaceans and isolated actinobacteria are not random and might represent long-term symbiotic interactions.

Amphipod bioassay of selected sediments from Sequim Bay, Washington

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

Ramsdell, K.A.; Strand, J.A.; Cullinan, V. I.

1989-06-01

Amphipod bioassays performed during reconnaissance surveys of Sequim Bay in 1983--1984 for the US Environmental Protection Agency suggested possible sediment toxicity at three sites. These findings were not supported by other biological analyses and tests (dominant infauna, oyster larvae test) nor by the finding of relatively low levels of priority pollutants. In 1988, a re-examination of the 1983--1984 sites demonstrated that the Sequim Bay sediments were clearly nontoxic. Mean survivorship ranged from 89 to 100%. It was hypothesized that earlier indications of toxicity may have been due to a relatively high percentage of fines ({ge}80%) and/or a relatively low interstitialmore » salinity (24%) encountered at one or more of the 1983--1984 sites. The continued use of Sequim Bay as both a reference bay and a source of control sediment in future marine research is recommended. 13 refs., 5 figs., 3 tabs.« less

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.

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

Bioconcentration model for non-ionic, polar, and ionizable organic compounds in amphipod.

PubMed

Chen, Ciara Chun; Kuo, Dave Ta Fu

2018-05-01

The present study presents a bioconcentration model for non-ionic, polar, and ionizable organic compounds in amphipod based on first-order kinetics. Uptake rate constant k 1 is modeled as logk1=10.81logKOW + 0.15 (root mean square error [RMSE] = 0.52). Biotransformation rate constant k M is estimated using an existing polyparameter linear free energy relationship model. Respiratory elimination k 2 is calculated as modeled k 1 over theoretical biota-water partition coefficient K biow considering the contributions of lipid, protein, carbohydrate, and water. With negligible contributions of growth and egestion over a typical amphipod bioconcentration experiment, the bioconcentration factor (BCF) is modeled as k 1 /(k M  + k 2 ) (RMSE = 0.68). The proposed model performs well for non-ionic organic compounds (log K OW range = 3.3-7.62) within 1 log-unit error margin. Approximately 12% of the BCFs are underpredicted for polar and ionizable compounds. However, >50% of the estimated k 2 values are found to exceed the total depuration rate constants. Analyses suggest that these excessive k 2 values and underpredicted BCFs reflect underestimation in K biow , which may be improved by incorporating exoskeleton as a relevant partitioning component and refining the membrane-water partitioning model. The immediate needs to build up high-quality experimental k M values, explore the sorptive role of exoskeleton, and investigate the prevalence of k 2 overestimation in other bioconcentration models are also identified. The resulting BCF model can support, within its limitations, the ecotoxicological and risk assessment of emerging polar and ionizable organic contaminants in aquatic environments and advance the science of invertebrate bioaccumulation. Environ Toxicol Chem 2018;37:1378-1386. © 2018 SETAC. © 2018 SETAC.

Scavenging amphipods: sentinels for penetration of mercury and persistent organic chemicals into food webs of the deep Arctic Ocean.

PubMed

Bidleman, Terry F; Stern, Gary A; Tomy, Gregg T; Hargrave, Barry T; Jantunen, Liisa M; Macdonald, Robie W

2013-06-04

Archived specimens of the scavenging amphipod Eurythenes gryllus, collected from 2075 to 4250 m below the surface on five expeditions to the western and central Arctic Ocean between 1983 and 1998, were analyzed for total mercury (∑Hg), methyl mercury (MeHg), polychlorinated biphenyls (PCBs) and other industrial or byproduct organochlorines (chlorobenzenes, pentachloroanisole, octachlorostyrene), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs). Median ∑Hg concentrations ranged from 70 to 366 ng g(-1) wet weight (ww). MeHg concentrations (3.55 to 23.5 ng g(-1) ww) accounted for 1.7 to 20.1% (median 3.7%) of ∑Hg. ∑Hg and MeHg were positively and significantly correlated with ww (∑Hg r(2) = 0.18, p = 0.0004, n = 63; MeHg r(2) = 0.42, p = 0.0004, n = 25), but not significantly with δ(13)C nor δ(15)N. Median concentrations of total persistent organic pollutants (POPs) ranged from 9750 to 156,000 ng g(-1) lipid weight, with order of abundance: ∑TOX (chlorobornanes quantified as technical toxaphene) > ∑PCBs > ∑DDTs > ∑chlordanes > ∑mirex compounds > ∑BDEs ∼ ∑chlorobenzenes ∼ octachlorostyrene > α-hexachlorocyclohexane ∼ hexachlorobenzene ∼ pentachloroanisole. Enantioselective accumulation was found for the chiral OCPs o,p'-DDT, cis- and trans-chlordane, nonachlor MC6 and oxychlordane. Lipid-normalized POPs concentrations were elevated in amphipods with lipid percentages ≤10%, suggesting that utilization of lipids resulted in concentration of POPs in the remaining lipid pool. Multidimensional Scaling (MDS) analysis using log-transformed physiological variables and lipid-normalized organochlorine concentrations distinguished amphipods from the central vs western arctic stations. This distinction was also seen for PCB homologues, whereas profiles of other compound classes were more related to specific stations rather than central-west differences.

Manipulative parasites may not alter intermediate host distribution but still enhance their transmission: field evidence for increased vulnerability to definitive hosts and non-host predator avoidance.

PubMed

Lagrue, C; Güvenatam, A; Bollache, L

2013-02-01

Behavioural alterations induced by parasites in their intermediate hosts can spatially structure host populations, possibly resulting in enhanced trophic transmission to definitive hosts. However, such alterations may also increase intermediate host vulnerability to non-host predators. Parasite-induced behavioural alterations may thus vary between parasite species and depend on each parasite definitive host species. We studied the influence of infection with 2 acanthocephalan parasites (Echinorhynchus truttae and Polymorphus minutus) on the distribution of the amphipod Gammarus pulex in the field. Predator presence or absence and predator species, whether suitable definitive host or dead-end predator, had no effect on the micro-distribution of infected or uninfected G. pulex amphipods. Although neither parasite species seem to influence intermediate host distribution, E. truttae infected G. pulex were still significantly more vulnerable to predation by fish (Cottus gobio), the parasite's definitive hosts. In contrast, G. pulex infected with P. minutus, a bird acanthocephalan, did not suffer from increased predation by C. gobio, a predator unsuitable as host for P. minutus. These results suggest that effects of behavioural changes associated with parasite infections might not be detectable until intermediate hosts actually come in contact with predators. However, parasite-induced changes in host spatial distribution may still be adaptive if they drive hosts into areas of high transmission probabilities.

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

USGS Publications Warehouse

Lasier, Peter J.; 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.

Crustacean hyperglycemic and vitellogenesis-inhibiting hormones in the lobster Homarus gammarus.

PubMed

Ollivaux, Céline; Vinh, Joëlle; Soyez, Daniel; Toullec, Jean-Yves

2006-05-01

Crustacean hyperglycemic hormone (CHH) and vitellogenesis-inhibiting hormone (VIH), produced by the X organ-sinus gland neurosecretory complex, belong to a peptide group referred to as the CHH family, which is widely distributed in arthropods. In this study, genetic variants and post-translationally modified isoforms of CHH and VIH were characterized in the European lobster Homarus gammarus. With the use of RP-HPLC and ELISA with specific antibodies that discriminate between stereoisomers of CHH and VIH, two groups of CHH-immunoreactive peaks were characterized from HPLC fractions of sinus gland extract (CHH A and CHH B); each group contained two variants (CHH and D-Phe3CHH). In the same way, two VIH-immunoreactive peaks (VIH and D-Trp4VIH) were demonstrated in HPLC fractions from sinus gland extract. The masses of these different neuropeptides were determined by FT-ICR MS: CHH A and CHH B spectra exhibited monoisotopic ions at 8557.05 Da and 8527.04 Da, respectively, and both VIH isomers displayed an m/z value of 9129.19 Da. Two full-length cDNAs encoding preprohomones of CHH A and CHH B and only one cDNA for VIH precursor were cloned and sequenced from X organ RNA. Comparison of CHH sequences between European lobster and other Astacoidea suggests that the most hydrophobic form appeared first during crustacean evolution.

Stream macroinvertebrate drift response to pulsed exposure of the synthetic pyrethroid lambda-cyhalothrin.

PubMed

Lauridsen, Rasmus B; Friberg, Nikolai

2005-10-01

Outdoor experimental channels were used to study the behavioral changes of stream macroinvertebrates exposed to a pulse of the pyrethroid insecticide lambda-cyhalothrin. The primary end point was the number of macroinvertebrates drifting, but the mobility of macroinvertebrates caught in the drift also was assessed. A specified number of two insect species, Baetis rhodani and Leuctra fusca/digitata, and of the amphipod Gammarus pulex were introduced into small replicated subsections of the experimental channels. Macroinvertebrates were allowed to acclimatize for 26 h prior to a 60-min pulsed exposure to lambda-cyhalothrin. Measurement was initiated 2 h before pesticide application and continued for the following 24 h. Pulse concentrations of lambda-cyhalothrin of 0.001, 0.01, 0.1, and 1.0 microg L(-1) were applied, and each experiment was replicated 8 times. All three species responded to the pesticide pulse with catastrophic drift. The 0.001 microg L(-1) treatment caused a significant increase in the drift of Gammarus, whereas the drift response threshold was 0.01 microg L(-1) for the two insect species. Drift response onset followed the applied pulse concentration, with the highest concentrations resulting in more individuals of all species entering drift at an early stage. The majority of individuals caught in drift samples during low concentrations showed no change in mobility. At the two highest concentrations, however, both Baetis and Leuctra were in the process of being immobilized, with Leuctra the more sensitive of the two. In contrast, only a few of the Gammarus individuals caught showed changes in mobility after the high-concentration treatments. The present study shows that lambda-cyhalothrin is a potential hazard for macroinvertebrate populations in headwater streams. The clear species-specific responses indicate that sublethal doses have the potential to change the macroinvertebrate community structure. (c) 2005 Wiley Periodicals, Inc.

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.

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.

Studies on the Biology of the Tube-Building Amphipod Microdeutopus gryllotalpa. A Model for Marine Fouling Processes.

DTIC Science & Technology

1984-01-01

two pairs of chelae to carry the females. But, in addition, males of different genera carry their females in different, but highly stereotyped ways...173 (1980) Shillaker. R. 0. and P. G. Moore: Tube building by the amphipods Lang. K.: The genus Oosaccus Richardson and the brood pouch Lembos...from three genera, has shown that the smaller pair is used. In addition, the use of theme gnathopods is highly stereotyped , and generic-specific

Neogene paleogeography provides context for understanding the origin and spatial distribution of cryptic diversity in a widespread Balkan freshwater amphipod

PubMed Central

Mamos, Tomasz; Bącela-Spychalska, Karolina; Rewicz, Tomasz; Wattier, Remi A.

2017-01-01

Background The Balkans are a major worldwide biodiversity and endemism hotspot. Among the freshwater biota, amphipods are known for their high cryptic diversity. However, little is known about the temporal and paleogeographic aspects of their evolutionary history. We used paleogeography as a framework for understanding the onset of diversification in Gammarus roeselii: (1) we hypothesised that, given the high number of isolated waterbodies in the Balkans, the species is characterised by high level of cryptic diversity, even on a local scale; (2) the long geological history of the region might promote pre-Pleistocene divergence between lineages; (3) given that G. roeselii thrives both in lakes and rivers, its evolutionary history could be linked to the Balkan Neogene paleolake system; (4) we inspected whether the Pleistocene decline of hydrological networks could have any impact on the diversification of G. roeselii. Material and Methods DNA was extracted from 177 individuals collected from 26 sites all over Balkans. All individuals were amplified for ca. 650 bp long fragment of the mtDNA cytochrome oxidase subunit I (COI). After defining molecular operational taxonomic units (MOTU) based on COI, 50 individuals were amplified for ca. 900 bp long fragment of the nuclear 28S rDNA. Molecular diversity, divergence, differentiation and historical demography based on COI sequences were estimated for each MOTU. The relative frequency, geographic distribution and molecular divergence between COI haplotypes were presented as a median-joining network. COI was used also to reconstruct time-calibrated phylogeny with Bayesian inference. Probabilities of ancestors’ occurrence in riverine or lacustrine habitats, as well their possible geographic locations, were estimated with the Bayesian method. A Neighbour Joining tree was constructed to illustrate the phylogenetic relationships between 28S rDNA haplotypes. Results We revealed that G. roeselii includes at least 13 cryptic

Effects of endosulfan, thiamethoxam, and indoxacarb in combination with atrazine on multi-biomarkers in Gammarus kischineffensis.

PubMed

Demirci, Özlem; Güven, Kemal; Asma, Dilek; Öğüt, Serdal; Uğurlu, Pelin

2018-01-01

Studies addressing the toxicity of pesticides towards non-target organisms focus on the median lethal concentration and biochemical response of individual pesticides. However, when determining environmental risks, it is important to test the combined effects of pesticides, such as insecticides and herbicides, which are frequently used together in agricultural areas. Here we aimed to investigate the toxic effects of the combined use of the herbicide atrazine and the insecticides, endosulfan, indoxacarb, and thiamethoxam on Gammarus kischineffensis. To do this, we tested the activities of oxidative stress, detoxification, and neurotoxicity biomarkers. Compared to atrazine alone, we detected higher glutathione-S-transferase, catalase and superoxide dismutase activities (oxidative stress biomarkers) when atrazine was combined with either endosulfan or indoxacarb. However, higher IBR values were determined in organisms where pesticide mixtures were used according to individual use. Based on these results, mixtures of atrazine and other pesticides may cause synergistic effects and may be evidence of increased toxicity and oxidative stress. Copyright © 2017 Elsevier Inc. All rights reserved.

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...

Susceptibility of juvenile European lobster Homarus gammarus to shrimp products infected with high and low doses of white spot syndrome virus.

PubMed

Bateman, K S; Munro, J; Uglow, B; Small, H J; Stentiford, G D

2012-08-27

White spot syndrome virus (WSSV) is the most important pathogen known to affect the sustainability and growth of the global penaeid shrimp farming industry. Although most commonly associated with penaeid shrimp farmed in warm waters, WSSV is also able to infect, cause disease in and kill a wide range of other decapod crustaceans, including lobsters, from temperate regions. In 2005, the European Union imported US$500 million worth of raw frozen or cooked frozen commodity products, much of which originated in regions positive for white spot disease (WSD). The presence of WSSV within the UK food market was verified by means of nested PCR performed on samples collected from a small-scale survey of supermarket commodity shrimp. Passage trials using inoculum derived from commodity shrimp from supermarkets and delivered by injection to specific pathogen-free Pacific white shrimp Litopenaeus vannamei led to rapid mortality and pathognomonic signs of WSD in the shrimp, demonstrating that WSSV present within commodity shrimp was viable. We exposed a representative European decapod crustacean, the European lobster Homarus gammarus, to a single feeding of WSSV-positive, supermarket-derived commodity shrimp, and to positive control material (L. vannamei infected with a high dose of WSSV). These trials demonstrated that lobsters fed positive control (high dose) frozen raw products succumbed to WSD and displayed pathognomonic signs associated with the disease as determined by means of histology and transmission electron microscopy. Lobsters fed WSSV-positive, supermarket-derived commodity shrimp (low dose) did not succumb to WSD (no mortality or pathognomonic signs of WSD) but demonstrated a low level or latent infection via PCR. This study confirms susceptibility of H. gammarus to WSSV via single feedings of previously frozen raw shrimp products obtained directly from supermarkets.

Lethal and behavioral impacts of diesel and fuel oil on the Antarctic amphipod Paramoera walkeri.

PubMed

Brown, Kathryn E; King, Catherine K; Harrison, Peter L

2017-09-01

Toxicity testing with Antarctic species is required for risk assessment of fuel spills in Antarctic coastal waters. The lethal and sublethal (movement behavior) sensitivities of adults and juveniles of the Antarctic amphipod Paramoera walkeri to the water accommodated fractions (WAFs) of 3 fuels were estimated in extended-duration tests at -1 °C to 21 d. Response of P. walkeri for lethal hydrocarbon concentrations was slow, with 50% lethal concentrations (LC50s) first able to be estimated at 7 d for adults exposed to Special Antarctic Blend diesel (SAB), which had the highest hydrocarbon concentrations of the 3 fuel WAFs. Juveniles showed greater response to marine gas oil (MGO) and intermediate residual fuel oil (IFO 180) at longer exposure durations and were most sensitive at 21 d to IFO 180 (LC50 = 12 μg/L). Adults were initially more sensitive than juveniles; at 21 d, however, juveniles were more than twice as sensitive as adults to SAB (LC50 = 153 μg/L and 377 μg/L, respectively). Significant effects on movement behavior were evident at earlier time points and lower concentrations than was mortality in all 3 fuel WAFs, and juveniles were highly sensitive to sublethal effects of MGO. These first estimates of Antarctic amphipod sensitivity to diesel and fuel oils in seawater contribute to the development of ecologically relevant risk assessments for management of hydrocarbon contamination in the region. Environ Toxicol Chem 2017;36:2444-2455. © 2017 SETAC. © 2017 SETAC.

Contrasting morphological and DNA barcode-suggested species boundaries among shallow-water amphipod fauna from the southern European Atlantic coast.

PubMed

Lobo, Jorge; Ferreira, Maria S; Antunes, Ilisa C; Teixeira, Marcos A L; Borges, Luisa M S; Sousa, Ronaldo; Gomes, Pedro A; Costa, Maria Helena; Cunha, Marina R; Costa, Filipe O

2017-02-01

In this study we compared DNA barcode-suggested species boundaries with morphology-based species identifications in the amphipod fauna of the southern European Atlantic coast. DNA sequences of the cytochrome c oxidase subunit I barcode region (COI-5P) were generated for 43 morphospecies (178 specimens) collected along the Portuguese coast which, together with publicly available COI-5P sequences, produced a final dataset comprising 68 morphospecies and 295 sequences. Seventy-five BINs (Barcode Index Numbers) were assigned to these morphospecies, of which 48 were concordant (i.e., 1 BIN = 1 species), 8 were taxonomically discordant, and 19 were singletons. Twelve species had matching sequences (<2% distance) with conspecifics from distant locations (e.g., North Sea). Seven morphospecies were assigned to multiple, and highly divergent, BINs, including specimens of Corophium multisetosum (18% divergence) and Dexamine spiniventris (16% divergence), which originated from sampling locations on the west coast of Portugal (only about 36 and 250 km apart, respectively). We also found deep divergence (4%-22%) among specimens of seven species from Portugal compared to those from the North Sea and Italy. The detection of evolutionarily meaningful divergence among populations of several amphipod species from southern Europe reinforces the need for a comprehensive re-assessment of the diversity of this faunal group.

Health effects of metoprolol in epibenthic and endobenthic invertebrates-A basis to validate future in vitro biotests for effect-based biomonitoring.

PubMed

Jungmann, Dirk; Berg, Kristin; Dieterich, Andreas; Frank, Martin; Gräf, Tonya; Scheurer, Marco; Schwarz, Simon; Siewert, Carmen; Oetken, Matthias

2017-02-23

The aim of this study was to determine the effect data for metoprolol as a model substance for beta-blockers in aquatic invertebrates. The results will be used as a basis for the validation of future mode of action-based in vitro test systems targeting this class of pharmaceuticals. Effects of metoprolol were investigated in two autochthonous species with high relevance in stream ecology: the amphipod Gammarus fossarum and the oligochaete Lumbriculus variegatus. Mortality in G. fossarum was not observed in acute toxicity testing (48 h), and a significant increase of mortality at 45 mg/L was found when amphipods were exposed chronically (40 days). The most sensitive population-relevant endpoints were the juvenile-adult ratio and number of egg-bearing females with NOEC/LOEC-values of 5/15 mg/L. No proteotoxic effects were identified in G. fossarum. The sediment toxicity test with L. variegatus according to the OECD Guideline 225 with an exposure time of 28 days resulted in EC 10 -values of 92.5 and 126.1 mg/kg dw for the endpoints reproduction and biomass, respectively. In L. variegatus the response kinetics of Hsp70 showed no significant difference between the treatments. A tendency for rising lipid peroxide concentrations was found between 0.03 and 10 mg/kg dw , which were significant between the treatments, but not to the control.

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.

Vertical distribution and daily migrations of hyperiid amphipods in the northern Benguela in relation to water column stratification

NASA Astrophysics Data System (ADS)

Cornet, Carme; Gili, Josep-Maria

1993-11-01

The vertical distribution and migratory behaviour of hyperiid amphipods were studied in a series of tows carried out during a 48-h sampling period at an oceanic station at the northern edge of the Benguela System during a major penetration by Angola Current waters. A total of 49 species of hyperiid amphipods were collected; of these, Tetrathyrus forcipatus was the most abundant, with densities greater than two individuals per 10 m 3. Vibilia armata, Lestrigonus latissimus, L. bengalensis and Paratyphis promontorii were also highly abundant. During the sampling period most species were concentrated in the uppermost 40 m of the water column, though in other regions the vertical distribution of these same species has been reported to be broader. Only a few species were able to migrate through the thermocline. We hypothesize that both the non-migratory behaviour and the aggregation of individuals and species were caused by two primary factors: the existence of a strong thermocline, which hindered the transit of species to deeper layers, and abundant concentrations of gelatinous zooplankton above the thermocline. Hyperiids and the gelatinous zooplankton, particularly medusae and siphonophores, exhibited a close association during the sampling period, suggesting that hyperiids are able to partition their habitat by using the different medusan and siphonophoran species as specific substrates, thereby reducing interspecific competition.

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...

Screening differentially expressed genes in an amphipod (Hyalella azteca) exposed to fungicide vinclozolin by suppression subtractive hybridization.

PubMed

Wu, Yun H; Wu, Tsung M; Hong, Chwan Y; Wang, Yei S; Yen, Jui H

2014-01-01

Vinclozolin, a dicarboximide fungicide, is an endocrine disrupting chemical that competes with an androgenic endocrine disruptor compound. Most research has focused on the epigenetic effect of vinclozolin in humans. In terms of ecotoxicology, understanding the effect of vinclozolin on non-target organisms is important. The expression profile of a comprehensive set of genes in the amphipod Hyalella azteca exposed to vinclozolin was examined. The expressed sequence tags in low-dose vinclozolin-treated and -untreated amphipods were isolated and identified by suppression subtractive hybridization. DNA dot blotting was used to confirm the results and establish a subtracted cDNA library for comparing all differentially expressed sequences with and without vinclozolin treatment. In total, 494 differentially expressed genes, including hemocyanin, heatshock protein, cytochrome, cytochrome oxidase and NADH dehydrogenase were detected. Hemocyanin was the most abundant gene. DNA dot blotting revealed 55 genes with significant differential expression. These genes included larval serum protein 1 alpha, E3 ubiquitin-protein ligase, mitochondrial cytochrome c oxidase, mitochondrial protein, proteasome inhibitor, hemocyanin, zinc-finger-containing protein, mitochondrial NADH-ubiquinone oxidoreductase and epididymal sperm-binding protein. Vinclozolin appears to upregulate stress-related genes and hemocyanin, related to immunity. Moreover, vinclozolin downregulated NADH dehydrogenase, related to respiration. Thus, even a non-lethal concentration of vinclozolin still has an effect at the genetic level in H. azteca and presents a potential risk, especially as it would affect non-target organism hormone metabolism.

Cold-adapted digestive aspartic protease of the clawed lobsters Homarus americanus and Homarus gammarus: biochemical characterization.

PubMed

Rojo, Liliana; García-Carreño, Fernando; de Los Angeles Navarrete del Toro, Maria

2013-02-01

Aspartic proteinases in the gastric fluid of clawed lobsters Homarus americanus and Homarus gammarus were isolated to homogeneity by single-step pepstatin-A affinity chromatography; such enzymes have been previously identified as cathepsin D-like enzymes based on their deduced amino acid sequence. Here, we describe their biochemical characteristics; the properties of the lobster enzymes were compared with those of its homolog, bovine cathepsin D, and found to be unique in a number of ways. The lobster enzymes demonstrated hydrolytic activity against synthetic and natural substrates at a wider range of pH; they were more temperature-sensitive, showed no changes in the K(M) value at 4°C, 10°C, and 25°C, and had 20-fold higher k(cat)/K(M) values than bovine enzyme. The bovine enzyme was temperature-dependent. We propose that both properties arose from an increase in molecular flexibility required to compensate for the reduction of reaction rates at low habitat temperatures. This is supported by the fast denaturation rates induced by temperature.

Toxicity of five forest insecticides to cutthroat trout and two species of aquatic invertebrates

USGS Publications Warehouse

Woodward, D.F.; Mauck, W.L.

1980-01-01

The Northern Rocky Mountain region has had scattered infestation of the western spruce budworm Christoneura occidentalis since the early 1900's (U.S. DEPARTMENT OF AGRICULTURE (USDA) 1976b). On the basis of aerial surveys in 1975, TUNNOCK et al. (1976), estimated that budworm defoliation occurred on 2,278,804 acres of six National Forests in Montana. Since the use of DDT was banned in 1972, there has been a need to develop alternative insecticides with the efficacy of DDT but without its environmental risk. These insecticides must be effective in controlling the budworm, but should not persist in the environment or be toxic to other organisms. The organophosphate and carbamate insecticides are relatively nonpersistent and generally present only a moderate hazard to fish when applied according to label recommendations. The USDA Forest Service has been investigating the effectiveness of these two classes of insecticides against the budworm, and the Columbia National Fisheries Research Laboratory of the U.S. Fish and Wildlife Service has been cooperating with the Forest Service conducted pilot control projects in eastern Montana in 1975 and 1976 to determine the efficacy and environmental impact of acephate, carbaryl, and trichlorfon in controlling the western budworm (USDA 1976 b). In 1975, a similar type project was carried out in Maine with aminocarb, fenitrothion, and trichlorfon (USDA 1976 a).Acephate, fenitrothion, and trichlorfon (organophosphate insecticides) and aminocarb and carbaryl (carbamate insecticides) were selected for toxicity tests against cutthroat trout (Salmo clarki), a stonefly (Pteronarcella badia), and a freshwater amphipod (Gammarus pseudolimnaeus) edemic in streams of the northern Rocky Mountains. Populations of cutthroat trout inhabit lakes and streams in the Rocky Mountains which include some of the most pristine habitat and fisheries in North America. Pteronarcella and Gammarus provide forage for cutthroat trout and feed on decaying

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.

Toxicity of chromium (VI) to two mussels and an amphipod in water-only exposures with or without a co-stressor of elevated temperature, zinc, or nitrate

USGS Publications Warehouse

Wang, Ning; Kunz, James L.; Ivey, Chris D.; Ingersoll, Christopher G.; Barnhart, M. Christopher; Glidewell, Elizabeth A.

2017-01-01

The objectives of the present study were to develop methods for propagating western pearlshell (Margaritifera falcata) for laboratory toxicity testing and evaluate acute and chronic toxicity of chromium VI [Cr(VI)] to the pearlshell and a commonly tested mussel (fatmucket, Lampsilis siliquoidea at 20 °C or in association with a co-stressor of elevated temperature (27 °C), zinc (50 µg Zn/L), or nitrate (35 mg NO3/L). A commonly tested invertebrate (amphipod, Hyalella azteca) also was tested in chronic exposures. Newly transformed pearlshell (~1 week old) were successfully cultured and tested in acute 96 h Cr exposures (control survival 100%). However, the grow-out of juveniles in culture for chronic toxicity testing was less successful and chronic 28-day Cr toxicity tests started with 4 month-old pearlshell failed due to low control survival (39–68%). Acute median effect concentration (EC50) for the pearlshell (919 µg Cr/L) and fatmucket (456 µg Cr/L) tested at 20 °C without a co-stressor decreased by a factor of > 2 at elevated temperature but did not decrease at elevated Zn or elevated NO3. Chronic 28-day Cr tests were completed successfully with the fatmucket and amphipod (control survival 83–98%). Chronic maximum acceptable toxicant concentration (MATC) for fatmucket at 20 °C (26 µg Cr/L) decreased by a factor of 2 at elevated temperature or NO3 but did not decrease at elevated Zn. However, chronic MATC for amphipod at 20 °C (13 µg Cr/L) did not decrease at elevated temperature, Zn, or NO3. Acute EC50s for both mussels tested with or without a co-stressor were above the final acute value used to derive United States Environmental Protection Agency acute water quality criterion (WQC) for Cr(VI); however, chronic MATCs for fatmucket at elevated temperature or NO3 and chronic MATCs for the amphipod at 20 °C with or without elevated Zn or NO3 were about equal to the chronic WQC. The results indicate that (1) the elevated temperature

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; 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 United States Environmental Protection Agency 2000; ASTM American Society for Testing and Materials International 2012). Toxicity end points evaluated in the amphipod and midge exposures included the effects of these field-collected sediments on survival, weight, or biomass of the test organisms.

Bottom-up and top-down triggers of diversification: A new look at the evolutionary ecology of scavenging amphipods in the deep sea

NASA Astrophysics Data System (ADS)

Havermans, Charlotte; Smetacek, Victor

2018-05-01

The initial, anthropocentric view of the deep ocean was that of a hostile environment inhabited by organisms rendered lethargic by constant high pressure, low temperature and sparse food supply, hence evolving slowly. This conceptual framework of a spatially and temporally homogeneous, connected, strongly bottom-up controlled habitat implied a strong constraint on, or poor incentive for, speciation. Hence, the discovery in the late 1960s of high species diversity of abyssal benthic invertebrates came as a surprise. Since then, the slow-motion view of deep-sea ecology and evolution has speeded up and diversified in the light of increasing evidence accumulating from in situ visual observations complemented by molecular and other tools. The emerging picture is that of a much livelier, highly diversified and more complex deep-sea fauna than previously assumed. In this review we examine the consequences of the incoming information for developing a broader view of evolutionary ecology in the deep sea, and for scavenging amphipods in particular. We revisit the food supply to the deep-sea floor and hypothesize that the dead bodies of animals, ranging from zooplankton to large fish are likely to be a more important source of food than their friable faeces. Camera observations of baited traps indicate that amphipod carrion-feeders arrive within hours at the bait which continues to draw new individuals for days to months later, presumably by scent trails in tidal currents. We explore the different stages of food acquisition upon which natural selection may have acted, from detection to ingestion, and discuss the possibility of a broader range of food acquisition strategies, including predation and specializations. Although currently neglected in deep-sea ecology, top-down factors are likely to play a more important role in the evolution of deep-sea organisms. Predation on amphipods at baits by bathyal and abyssal fishes, and large predatory crustaceans in the hadal zone, is

Transcriptome of the Antarctic amphipod Gondogeneia antarctica and its response to pollutant exposure.

PubMed

Kang, Seunghyun; Kim, Sanghee; Park, Hyun

2015-12-01

Gondogeneia antarctica is widely distributed off the western Antarctic Peninsula and is a key species in the Antarctic food web. In this study, we performed Illumina sequencing to produce a total of 4,599,079,601 (4.6Gb) nucleotides and a comprehensive transcript dataset for G. antarctica. Over 46 million total reads were assembled into 20,749 contigs, and 12,461 annotated genes were predicted by Blastx. The RNA-seq results after exposure to three pollutants showed that 658, 169 and 367 genes that were potential biomarkers of responses to pollutants for this species were specifically upregulated after exposure to PCBs (Polychlorinated biphenyls), PFOS (Perfluorooctanesulfonic acid) and PFOA (Perfluorooctanoic acid), respectively. These data represent the first transcriptome resource for the Antarctic amphipod G. antarctica and provide a useful resource for studying Antarctic marine species. Copyright © 2015 Elsevier B.V. All rights reserved.

Feeding ecology of long-tailed ducks Clangula hyemalis wintering on the Nantucket Shoals

USGS Publications Warehouse

White, Timothy P.; Veit, Richard R.; Perry, Matthew C.

2009-01-01

A substantial proportion, perhaps 30%, of the North American breeding population of Long-tailed Ducks (Clangula hyemalis) winter in the vicinity of Nantucket Island, Massachusetts. These birds spend the night on Nantucket Sound and commute during daylight hours to the Nantucket Shoals, which extend about 65 km offshore from the southeastern corner of Nantucket. Strip transects done from a single-engine plane in 1997 and 1998 indicated that Long-tailed Ducks foraged over the shallower (<= 20 m depth) portions of the Nantucket Shoals, up to 70 km offshore. Diet analyses of ten birds collected in February 1999 and five in December 2006 showed that they fed principally (106.6 +/- 42.0 individuals per crop) on Gammarus annulatus, a pelagic amphipod that often forms large aggregations, and is consumed by several species of fish and marine mammals. Our findings emphasize the importance of conservation of the Nantucket Shoals and the prevention of oil spills or other potentially harmful accidents.

Bioaccumulation of per- and polyfluorinated alkyl substances (PFAS) in selected species from the Barents Sea food web.

PubMed

Haukås, Marianne; Berger, Urs; Hop, Haakon; Gulliksen, Bjørn; Gabrielsen, Geir W

2007-07-01

The present study reports concentrations and biomagnification potential of per- and polyfluorinated alkyl substances (PFAS) in species from the Barents Sea food web. The examined species included sea ice amphipod (Gammarus wilkitzkii), polar cod (Boreogadus saida), black guillemot (Cepphus grylle) and glaucous gull (Larus hyperboreus). These were analyzed for PFAS, polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs) and polybrominated diphenyl ethers (PBDEs). Perfluorooctane sulfonate (PFOS) was the predominant of the detected PFAS. Trophic levels and food web transfer of PFAS were determined using stable nitrogen isotopes (delta(15)N). No correlation was found between PFOS concentrations and trophic level within species. However, a non-linear relationship was established when the entire food web was analyzed. Biomagnification factors displayed values >1 for perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA), PFOS and SigmaPFAS(7). Multivariate analyses showed that the degree of trophic transfer of PFAS is similar to that of PCB, DDT and PBDE, despite their accumulation through different pathways.

Description of Pseudingolfiella possessionis n. sp. (Crustacea, Amphipoda) from sub-Antarctic Île de La Possession, Crozet archipelago: the second freshwater amphipod known from the Antarctic biome, a human introduction of Gondwanan ancestry?

PubMed

Smet, Willem H De

2015-03-31

A new species of freshwater amphipod, Pseudingolfiella possessionis n. sp. (Senticaudata, Pseudingolfiellidae), is described from the submerged moss vegetation of small brooklets at sub-Antarctic Île de La Possession, Crozet archipelago. It constitutes the second freshwater amphipod species known for the sub-Antarctic and Antarctic region, and the fourth member of the genus. The main characters distinguishing it from all congeners are: the spine on the posterior margin of the dactylus, incisor and lamina mobilis of mandible each with 5 teeth, the setation of the maxilliped, the vestigial second article of pleopod 3 in the female, the undulate and laterally notched posterolateral margin of the external ramus of uropods 1 and 2 in the male, the spinulate dorsomedian projection of the telson.

Bisphenol A in artificial indoor streams: II. Stress response and gonad histology in Gammarus fossarum (Amphipoda).

PubMed

Schirling, Martin; Jungmann, Dirk; Ladewig, Vanessa; Ludwichowski, Kai-Uwe; Nagel, Roland; Köhler, Heinz-R; Triebskorn, Rita

2006-03-01

The effects of the world wide-distributed chemical bisphenol A (BPA) on the endocrine system of vertebrates have been demonstrated in several studies. Here, we report on the impact of BPA (0, 5, 50 and 500 microg/l nominally, deduced effective concentrations 0, 0.24, 2.4, and 24.1 microg/l, respectively, all at 15 degrees C) on the 70 kD stress protein family (hsp70), the 90 kD stress protein family (hsp90), and gonad histology of the crustacean Gammarus fossarum exposed in artificial indoor streams. The animals were exposed for a maximum of 103 days and samples were taken at the beginning and at days 34, 69 and 103 of the experiment. Exposure to BPA resulted in accelerated maturation of oocytes in females and in a decline in the number and size of early vitellogenic oocytes. The level of hsp90, which plays a pivotal role in vertebrate sex steroid signal transduction, was significantly reduced by BPA. In all five streams, measured parameters did not indicate any captivity stress for a period of 69 days. Beyond this time, the mortality rate and proteotoxic effects, the latter measured by hsp70 expression, were found to be elevated.

Effect of water quality and confounding factors on digestive enzyme activities in Gammarus fossarum.

PubMed

Charron, L; Geffard, O; Chaumot, A; Coulaud, R; Queau, H; Geffard, A; Dedourge-Geffard, O

2013-12-01

The feeding activity and subsequent assimilation of the products resulting from food digestion allow organisms to obtain energy for growth, maintenance and reproduction. Among these biological parameters, we studied digestive enzymes (amylase, cellulase and trypsin) in Gammarus fossarum to assess the impact of contaminants on their access to energy resources. However, to enable objective assessment of a toxic effect of decreased water quality on an organisms' digestive capacity, it is necessary to establish reference values based on its natural variability as a function of changing biotic and abiotic factors. To limit the confounding influence of biotic factors, a caging approach with calibrated male organisms from the same population was used. This study applied an in situ deployment at 23 sites of the Rhone basin rivers, complemented by a laboratory experiment assessing the influence of two abiotic factors (temperature and conductivity). The results showed a small effect of conductivity on cellulase activity and a significant effect of temperature on digestive enzyme activity but only at the lowest temperature (7 °C). The experimental conditions allowed us to define an environmental reference value for digestive enzyme activities to select sites where the quality of the water impacted the digestive capacity of the organisms. In addition to the feeding rate, this study showed the relevance of digestive enzymes as biomarkers to be used as an early warning tool to reflect organisms' health and the chemical quality of aquatic ecosystems.

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.

Behavioural and physiological effects of the trophically transmitted cestode parasite, Cyathocephalus truncatus, on its intermediate host, Gammarus pulex.

PubMed

Franceschi, N; Rigaud, T; Moret, Y; Hervant, F; Bollache, L

2007-11-01

Some parasites with complex life-cycles are able to manipulate the behaviour of their intermediate hosts in a way that increases their transmission to the next host. Gammarids infected by the tapeworm Cyathocephalus truncatus (Cestoda: Spathebothriidea) are known to be more predated by fish than uninfected ones, but potential behavioural manipulation by the parasite has never been investigated. In this study, we tested the hypothesis that C. truncatus is able to manipulate the behaviour of one of its intermediate hosts, Gammarus pulex (Crustacea: Amphipoda). To assess if any behavioural change was linked to other phenotypic alterations, we also measured the immunity of infected and uninfected individuals and investigated the pathogenic effects of the parasite. Infected gammarids were significantly less photophobic than uninfected ones, but no effect of infection on the level of immune defence was found. The results on survival, swimming activity and oxygen consumption suggest that the parasite also has various pathogenic effects. However, the alteration in host phototaxis was not correlated to some of these pathogenic effects. Therefore, we propose that the modification in host reaction to light is a behavioural manipulation, explaining the previously observed increase of gammarid predation rate.

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.

Consequences of lower food intake on the digestive enzymes activities, the energy reserves and the reproductive outcome in Gammarus fossarum.

PubMed

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.

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.

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. Copyright © 2014 Elsevier Inc. All rights reserved.

Talitrid amphipods (Crustacea) as biomonitors for copper and zinc

NASA Astrophysics Data System (ADS)

Rainbow, P. S.; Moore, P. G.; Watson, D.

1989-06-01

Data are presented on the copper and zinc concentrations of four talitrid amphipod species (standard dry weight 10 mg), i.e. Orchestia gammarellus (Pallas), O. mediterranea Costa, Talitrus saltator Montagu and Talorchestia deshayesii (Audouin), from 31 sites in S.W. Scotland, N. Wales and S.W. England. More limited data are also presented for cadmium in O. gammarellus (three sites) and T. deshayesii (one site). In S.W. Scotland, copper concentrations were raised significantly in O. gammarellus from Whithorn and Auchencairn (Solway) and Loch Long and Holy Loch (Clyde). In S.W. England, copper concentrations were highest at Restronguet Creek, Torpoint and Gannel (Cornwall). Samples of O. gammarellus from Islay (inner Hebrides) taken adjacent to the effluent outfalls of local whisky distilleries fell into two groups based on copper concentrations (presumably derived from copper stills), the higher copper levels deriving from the more productive distilleries. High copper levels were found in T. saltator and Tal. deshayesii from Dulas Bay (Wales). Zinc levels in O. gammarellus were high in Holy Loch and Auchencairn (Scotland), Gannel and Torpoint (England) but extremely elevated (as was Zn in O. mediterranea) at Restronguet Creek. Zinc was also high in T. saltator from Dulas Bay (Wales), but not in Tal. deshayesii. Cadmium levels in O. gammarellus from Kilve (Bristol Channel) were much raised. These differences (a) conform with expectations of elevated bioavailability of these metals from well researched areas (S.W. England & N. Wales), and (b) identify hitherto unappreciated areas of enrichment in S.W. Scotland. Orchestia gammarellus is put forward as a suitable biomonitor for copper and zinc in British coastal waters.

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

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.

Life history and secondary production of the amphipod Haploops nirae (Kaim-Malka, 1976) in the Bay of Concarneau (South Brittany)

NASA Astrophysics Data System (ADS)

Rigolet, Carinne; Dubois, Stanislas F.; Droual, Gabin; Caisey, Xavier; Thiébaut, Eric

2012-11-01

Haploops nirae is a gregarious tubiculous amphipod that creates dense tube mats in two ecosystems of South Brittany (i.e. the Bay of Vilaine and the Bay of Concarneau). To assess the ecological consequences of its recent expansion, the pattern of population dynamics of H. nirae was determined from January 2010 to March 2011 at a 29 m deep station in the Bay of Concarneau with a sampling interval of ca. 3 weeks (23 sampling dates). Modal analysis of size-frequency distribution at each date was used to describe the life cycle and the population dynamics of H. nirae, and to estimate the annual secondary production using the increment summation method. We showed that H. nirae is a semelparous species exhibiting a biannual life cycle with a lifespan ranging from 24 to 28 months. The recruitment was extremely high in 2010 and occurred between January and April but most recruits arrived at the end of March. Recruits are produced by two year old individuals, which die shortly after hatching. Female densities were low in winter. Females produced only one brood during their lifetime with an average brood size of 29. H. nirae secondary production was estimated at 9.66 gDW m-2 y-1 and the production to biomass ratio (P/B¯) was 2.26 y-1. Results are compared with previous published data on other Ampeliscid amphipods. The biannual life cycle appears unusual for most of Ampeliscidae except for the genus Haploops where a biannual life cycle appears characteristic of this genus. The secondary production calculated for H. nirae was high compared to other biannual Ampeliscidae species and constituted one of the highest production values calculated for an Ampeliscid.

Mayaweckelia troglomorpha, a new subterranean amphipod species from Yucatán state, México (Amphipoda, Hadziidae)

PubMed Central

Angyal, Dorottya; Solís, Efraín Chávez; Magaña, Benjamín; Balázs, Gergely; Simoes, Nuno

2018-01-01

Abstract A detailed description of a new stygobiont species of the amphipod family Hadziidae, Mayaweckelia troglomorpha Angyal, sp. n. is given, based on material collected in four cenotes of Yucatán federal state, México. Morphology was studied under light microscopy and with scanning electron microscopy. Morphological description is complemented with mitochondrial cytochrome c oxidase subunit I (COI) sequences as barcodes, with affinities to the related taxa and with notes on the species’ ecology. Using COI Bayesian inference and genetic distance analyses, we show that the closest relative of the new species is M. cenoticola, forming a monophyletic group referring to the genus Mayaweckelia. Based on the available sequences, we also revealed that Mayaweckelia and Tuluweckelia are sister genera, standing close to the third Yucatán subterranean genus, Bahadzia. The data gathered on the habitat, distribution, abundance, and ecology will contribute to the conservation planning for M. troglomorpha Angyal, sp. n. PMID:29674859

Mayaweckelia troglomorpha, a new subterranean amphipod species from Yucatán state, México (Amphipoda, Hadziidae).

PubMed

Angyal, Dorottya; Solís, Efraín Chávez; Magaña, Benjamín; Balázs, Gergely; Simoes, Nuno

2018-01-01

A detailed description of a new stygobiont species of the amphipod family Hadziidae, Mayaweckelia troglomorpha Angyal, sp. n. is given, based on material collected in four cenotes of Yucatán federal state, México. Morphology was studied under light microscopy and with scanning electron microscopy. Morphological description is complemented with mitochondrial cytochrome c oxidase subunit I (COI) sequences as barcodes, with affinities to the related taxa and with notes on the species' ecology. Using COI Bayesian inference and genetic distance analyses, we show that the closest relative of the new species is M. cenoticola , forming a monophyletic group referring to the genus Mayaweckelia . Based on the available sequences, we also revealed that Mayaweckelia and Tuluweckelia are sister genera, standing close to the third Yucatán subterranean genus, Bahadzia . The data gathered on the habitat, distribution, abundance, and ecology will contribute to the conservation planning for M. troglomorpha Angyal, sp. n.

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

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

Macrofauna on flood delta shoals in the Wadden Sea with an underground association between the lugworm Arenicola marina and the amphipod Urothoe poseidonis

NASA Astrophysics Data System (ADS)

Lackschewitz, D.; Reise, K.

1998-06-01

Living conditions for macrofauna on flood delta shoals are determined by surf, strong currents and sediment mobility. Thus, a unique assemblage of invertebrate species colonize these far off-shore, low intertidal flats. We here describe the macrobenthic fauna of emerging shoals in the Wadden Sea between the islands of Römö and Sylt. Besides ubiquitous macroinvertebrates of the intertidal zone and species which attain their main distribution in the subtidal zone, the flood delta shoals are characterized by organisms adapted to live in these highly unstable sediments, like the polychaetes Spio martinensis, Streptosyllis websteri, Magelona mirabilis, Psammodrilus balanoglossoides, the pericarid crustaceans Cumopsis goodsiri, Tanaissus lilljeborgi, Bathyporeia sarsi and a few others. Average abundance (1440 m-2 of ind >1 mm) and biomass (12.9 g AFDW m-2) were low compared to other intertidal habitats in the Wadden Sea. Biomass was dominated by largesized individuals of the lugworm Arenicola marina. The U-shaped burrows of these polychaetes were inhabited by high numbers of Urothoe poseidonis. Maximum densities of these amphipods occurred in the deepest parts of the burrows. Sampling at approximately montly intervals revealed no apparent seasonality of U. poseidonis abundance. Together with small Capitella capitata, these amphipods constitute a deep-dwelling component of the macrofauna associated with lugworms, which is separated from all other macrofauna living at the sediment surface. As a response to rising sea level and increasing tidal ranges, we expect the unstable sandy shoals, inhabited by numerous Spio martinensis and Urothoe poseidonis, to expand within the Wadden Sea at the cost of stable sandy flats with abundant macrofauna.

Intersexual differences of heat shock response between two amphipods (Eulimnogammarus verrucosus and Eulimnogammarus cyaneus) in Lake Baikal

PubMed Central

Bedulina, Daria; Meyer, Michael F.; Gurkov, Anton; Kondratjeva, Ekaterina; Baduev, Boris; Gusdorf, Roman

2017-01-01

Acute temperature fluctuations are common in surface waters, and aquatic organisms may manifest physiological responses to punctuated temperature spikes long before behavioral responses. Ectotherms, especially cryophilic stenotherms such as those endemic to Lake Baikal (Siberia), may demonstrate specialized physiological responses to acute temperature increases because their proteomes have evolved to function most efficiently at lower temperatures (e.g., <10 °C). Therefore, our study questioned the nature and degree of variation in physiological response to acute thermal stress in two congenerous, endemic Baikal amphipod species, Eulimnogammarus verrucosus and Eulimnogammarus cyaneus. We hypothesized that because interspecific and intersexual thermosensitivity varies significantly among ectotherms, there would be divergent intersexual and interspecific strategies to withstand acute thermal stress, manifested in different protein compositions and concentrations. We exposed individuals to the species’ respective LT50 for one hour followed by a three-hour recovery period. We then performed 1D-PAGE, Western blotting, 2D-PAGE, and Mass Spectrometry techniques and assessed relative intersexual and interspecific changes in proteomic composition and heat shock protein 70 level. Our results demonstrate that females tend to be more sensitive to an acute thermal stimulus than males, most likely because females allocate significant energy to reproduction and less to heat shock response, evidenced by females’ significantly lower LT50time. Lower level of Hsp70 was found in females of the thermosensitive E. verrucosus compared to males of this species. No intersexual differences were found in Hsp70 level in thermotolerant E. cyaneus. Higher levels of hemocyanin subunits and arginine kinase were found in E. cyaneus females after heat shock and recovery compared to males, which was not found for E. verrucosus, suggesting interspecific mechanisms for E. cyaneus’s higher

The evil within? Systemic fungicide application in trees enhances litter quality for an aquatic decomposer-detritivore system.

PubMed

Newton, Kymberly; Zubrod, Jochen P; Englert, Dominic; Lüderwald, Simon; Schell, Theresa; Baudy, Patrick; Konschak, Marco; Feckler, Alexander; Schulz, Ralf; Bundschuh, Mirco

2018-06-05

Waterborne exposure towards fungicides is known to trigger negative effects in aquatic leaf-associated microbial decomposers and leaf-shredding macroinvertebrates. We expected similar effects when these organisms use leaf material from terrestrial plants that were treated with systemic fungicides as a food source since the fungicides may remain within the leaves when entering aquatic systems. To test this hypothesis, we treated black alder (Alnus glutinosa) trees with a tap water control or a systemic fungicide mixture (azoxystrobin, cyprodinil, quinoxyfen, and tebuconazole) at two worst-case application rates. Leaves of these trees were used in an experiment targeting alterations in two functions provided by leaf-associated microorganisms, namely the decomposition and conditioning of leaf material. The latter was addressed via the food-choice response of the amphipod shredder Gammarus fossarum. During a second experiment, the potential impact of long-term consumption of leaves from trees treated with systemic fungicides on G. fossarum was assessed. Systemic fungicide treatment altered the resource quality of the leaf material resulting in trends of increased fungal spore production and an altered community composition of leaf-associated fungi. These changes in turn caused a significant preference of Gammarus for microbially conditioned leaves that had received the highest fungicide treatment over control leaves. This higher food quality ultimately resulted in a higher gammarid growth (up to 300% increase) during the long-term feeding assay. Although the underlying mechanisms still need to be addressed, the present study demonstrates a positive indirect response in aquatic organisms due to systemic pesticide application in a terrestrial system. As the effects from the introduction of plant material treated with systemic fungicides strongly differ from those mediated via other pathways (e.g., waterborne exposure), our study provides a novel perspective of fungicide

Fungal composition on leaves explains pollutant-mediated indirect effects on amphipod feeding.

PubMed

Bundschuh, Mirco; Zubrod, Jochen P; Kosol, Sujitra; Maltby, Lorraine; Stang, Christoph; Duester, Lars; Schulz, Ralf

2011-07-01

The energy stored in coarse particulate organic matter, e.g. leaf litter, is released to aquatic ecosystems by breakdown processes involving microorganisms and leaf shredding invertebrates. The palatability of leaves and thus the feeding of shredders on leaf material are highly influenced by microorganisms. However, implications in the colonization of leaves by microorganisms (=conditioning) caused by chemical stressors are rarely studied. Our laboratory experiments, therefore, investigated for the first time effects of a fungicide on the conditioning process of leaf material by means of food-choice experiments using Gammarus fossarum (Crustacea: Amphipoda). Additionally, microbial analyses were conducted to facilitate the mechanistic understanding of the observed behavior. Gammarids significantly preferred control leaf discs over those conditioned in presence of the fungicide tebuconazole at concentrations of 50 and 500 μg/L. Besides the decrease of fungal biomass with increasing fungicide concentration, also the leaf associated fungal community composition showed that species preferred by gammarids, such as Alatospora acumunata, Clavariopsis aquatica, or Flagellospora curvula, were more frequent in the control. Tetracladium marchalianum, however, which is rejected by gammarids, was abundant in all treatments suggesting an increasing importance of this species for the lower leaf palatability--as other more palatable fungal species were almost absent--in the fungicide treatments. Hence, the food-choice behavior of G. fossarum seems to be a suitable indicator for alterations in leaf associated microbial communities, especially fungal species composition, caused by chemical stressors. Finally, this or similar test systems may be a reasonable supplement to the environmental risk assessment of chemicals in order to achieve its protection goals, as on the one hand, indirect effects may occur far below concentrations known to affect gammarids directly, and on the other

Low dose TBT exposure decreases amphipod immunocompetence and reproductive fitness.

PubMed

Jacobson, Therese; Sundelin, Brita; Yang, Gongda; Ford, Alex T

2011-01-17

The antifouling agent tributyltin (TBT) is a highly toxic pollutant present in many aquatic ecosystems. Despite of regulations on the usage of TBT, it remains in high concentrations in sediments both in harbors and in off-shore sites. The toxicity of TBT in mollusks is well documented. However, adverse effects in other aquatic organisms, such as crustaceans, are less well known. This study is an effort to assess the effects of environmentally realistic concentrations of TBT on an ecologically important species in Swedish fresh and brackish water ecosystems, the benthic amphipod Monoporeia affinis. Field collected animals were exposed during gonad maturation to TBT (70 and 170 ng/g sediment d wt) for five weeks in static microcosms with natural sediment. Exposure concentrations were chosen to reflect effects at concentrations found in Swedish coastal sediment, but below expected effects on survival. TBT exposure resulted in a statistically significant adverse effect on oocyte viability and a doubling of the prevalence of microsporidian parasites in females, from 17% in the control to 34% in the 170 ng TBT/g sediment d wt exposure. No effects on survival were observed. Borderline significant effects were observed on male sexual maturation in the 70 ng TBT/g d wt exposure and on ecdysteroid levels in the 170 ng/g sediment d wt exposure. Both reproduction and parasite infection effects are of ecological importance since they have the potential to affect population viability in the field. This study gives further evidence to the connection between low dose contaminant exposure and increases in microsporidian parasite infection. Copyright © 2010 Elsevier B.V. All rights reserved.

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.

Pesticide body burden of the crustacean Gammarus pulex as a measure of toxic pressure in agricultural streams.

PubMed

Shahid, Naeem; Becker, Jeremias Martin; Krauss, Martin; Brack, Werner; Liess, Matthias

2018-06-22

Risk assessments of toxicants in aquatic environments are typically based on the evaluation of concentrations in water or sediment. However, concentrations in water are highly variable, while the body burden may provide a better time-integrated measure of pesticide exposure and potential effects in aquatic organisms. Here, we quantified pesticide body burdens in a dominant invertebrate species from agricultural streams, Gammarus pulex, compared them pesticide concentrations in water samples, and linked the pesticide contamination with observed ecological effects on macroinvertebrate communities. In total, 19 of 61 targeted analytes were found in the organisms, ranging from 0.037 to 93.94 ng g-1 (wet weight). Neonicotinoids caused the highest toxic pressure among the pesticides detected in G. pulex. Using linear solvation energy relationships (LSERs), we derived equivalent pesticide concentrations in stream water based on the body burden. These equivalent concentrations correlated with the concentrations in water samples collected after run-off (65% of variance explained). Pesticide pressure significantly affected the aquatic macroinvertebrate community structure, expressed as SPEARpesticides, and caused, on average, threefold increased insecticide tolerance in G. pulex as a result of adaptation. The toxic pressure derived from body burden and from water samples similarly explained the change in community structure (68% and 64%). However, the increased tolerance of G. pulex to pesticides was better explained by the toxicity derived from body burden (70%) than by the toxicity from water samples (53%). We conclude that the internal body burden of macroinvertebrates is suitable to assess the overall pesticide exposure and effects in agricultural streams.

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.

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

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

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

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 assumingmore » 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.« less

Uptake, biotransformation and elimination of selected pharmaceuticals in a freshwater invertebrate measured using liquid chromatography tandem mass spectrometry.

PubMed

Miller, Thomas H; Bury, Nicolas R; Owen, Stewart F; Barron, Leon P

2017-09-01

Methods were developed to assess uptake and elimination kinetics in Gammarus pulex of nine pharmaceuticals (sulfamethazine, carbamazepine, diazepam, temazepam, trimethoprim, warfarin, metoprolol, nifedipine and propranolol) using targeted LC-MS/MS to determine bioconcentration factors (BCFs) using a 96 h toxicokinetic exposure and depuration period. The derived BCFs for these pharmaceuticals did not trigger any regulatory thresholds and ranged from 0 to 73 L kg -1 (sulfamethazine showed no bioconcentration). Metabolism of chemicals can affect accurate BCF determination through parameterisation of the kinetic models. The added selectivity of LC-MS/MS allowed us to develop confirmatory methods to monitor the biotransformation of propranolol, carbamazepine and diazepam in G. pulex. Varying concentrations of the biotransformed products; 4-hydroxypropranolol sulphate, carbamazepine-10,11-epoxide, nordiazepam, oxazepam and temazepam were measured following exposure of the precursor compounds. For diazepam, the biotransformation product nordiazepam was present at higher concentrations than the parent compound at 94 ng g -1 dw. Overall, the results indicate that pharmaceutical accumulation is low in these freshwater amphipods, which can potentially be explained by the rapid biotransformation and excretion. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Coexistence of two species of haplosporidian parasites in a population of the marine amphipod Parhyale hawaiensis with evidence for parasite phagocytosis and transmission mode.

PubMed

Ismail, Tarek Gad El-Kareem

2011-04-01

The amphipod Parhyale hawaiensis live hiding underneath stones and shingles along the shore line in supra-littoral zone of Sharm El-Nagha site, Hurghada city, Red Sea. The collected specimens of P. hawaiensis are infected with two protozoan parasites, Urosporidium sp. and Haplosporidium sp. which invade many organs of both females and males. The life cycle of the parasites was described in addition to their histopathological effects on host's tissues. The study showed some evidence for the defense reaction of the host as engulfing and degraded stages of parasites by granulocytes. The two parasite species coexist at different prevalence's in one host population and bi-infected individuals were few.

Differential tolerance of two Gammarus pulex populations transplanted from different metallogenic regions to a polymetal gradient.

PubMed

Khan, Farhan R; Irving, Jennifer R; Bury, Nicolas R; Hogstrand, Christer

2011-03-01

The River Hayle, Cornwall, UK exhibits pronounced Cu and Zn concentration gradients which were used to compare the metal handling abilities of two populations of Gammarus pulex (Crustacea: Amphipoda). One population was native to the Hayle region (Drym) and presumably has been historically impacted by elevated Cu and Zn levels, whilst naïve gammarids were collected from the River Cray, Kent, UK. Both populations were subject to a 32 day in situ exposure at four R. Hayle sites (Drym, Godolphin, Relubbus and St. Erth). Mortality (LT50), Cu and Zn accumulation and sub-cellular distribution, and oxidative stress (malondialdehyde production) increased with the expected Cu and Zn bioavailabilities at the four sites (i.e. Godolphin>Relubbus>St. Erth>Drym). The naïve population experienced greater metal induced effects in terms of Cu and Zn accumulation, oxidative stress responses and lower LT50s. Analysis of Cu and Zn sub-cellular distribution, however, revealed no significant differences in metal handling. In both populations each metal was localised predominantly to the sub-cellular fraction containing metal bound to metallothionein-like proteins (MTLP) or that holding both metal-rich granules (MRG) and exoskeleton, MTLP and MRG binding being indicative of metal detoxification. However, a greater capacity for detoxified metal storage is not a mechanism implicated in the perceived tolerance of the historically impacted gammarids. Instead our results suggest that the historically impacted population was adapted for lower uptake of Cu and Zn leading to lower bioaccumulation, stress response and ultimately mortality. These results demonstrate not only the usefulness of the in situ methodology, but also that differences in population exposure history can cause significant differences in metal responses during exposure at higher concentrations. Copyright © 2011 Elsevier B.V. All rights reserved.

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Environmental drivers defining linkages among life-history traits: mechanistic insights from a semiterrestrial amphipod subjected to macroscale gradients.

PubMed

Gómez, Julio; Barboza, Francisco R; Defeo, Omar

2013-10-01

Determining the existence of interconnected responses among life-history traits and identifying underlying environmental drivers are recognized as key goals for understanding the basis of phenotypic variability. We studied potentially interconnected responses among senescence, fecundity, embryos size, weight of brooding females, size at maturity and sex ratio in a semiterrestrial amphipod affected by macroscale gradients in beach morphodynamics and salinity. To this end, multiple modelling processes based on generalized additive mixed models were used to deal with the spatio-temporal structure of the data obtained at 10 beaches during 22 months. Salinity was the only nexus among life-history traits, suggesting that this physiological stressor influences the energy balance of organisms. Different salinity scenarios determined shifts in the weight of brooding females and size at maturity, having consequences in the number and size of embryos which in turn affected sex determination and sex ratio at the population level. Our work highlights the importance of analysing field data to find the variables and potential mechanisms that define concerted responses among traits, therefore defining life-history strategies.

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. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

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 (F ST = 0.086, R ST = 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

Comparison of an Ampelisca abdita growth rate test with other standard amphipod sediment toxicity tests

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

Schafer, K.; Weston, D.P.

1995-12-31

Amphipod crustaceans are often used to measure the toxicity of bulk sediments. Acute lethal bioassays are commonly employed, but this study investigated the potential for using a chronic growth bioassay with Ampelisca abdita. A potential advantage of this method is that the growth rate could be a more sensitive measure of contamination than mortality. Growth rates for A. abdita in sediments spiked with cadmium and crude oil were compared to mortality rates in A. abdita, Eohaustorius estuaries, and Rhepoxynius abronius in sediments with the same concentrations of contaminants. A. abdita was more sensitive to cadmium than the other two species.more » For crude oil, there was a significant shift in size distribution from the control even at concentrations as low as 150 mg/kg of oil. The standard acute lethal tests for all species, on the other hand, did not show significant mortality until at least 1,600 mg/kg. The results confirm that growth rates are a more sensitive indicator of toxicity, and to at least the three contaminants tested, A. abdita is as sensitive as E. estuarius and R. abronius. This study also confirmed the reported high mortality rates of E. estuaries in San Francisco Bay sediments. The causes of this high mortality are unknown but give further reason for using A. abdita for toxicity tests in this region.« less

A rhythmic modulatory gating system in the stomatogastric nervous system of Homarus gammarus. III. Rhythmic control of the pyloric CPG.

PubMed

Cardi, P; Nagy, F

1994-06-01

1. Two modulatory neurons, P and commissural pyloric (CP), known to be involved in the long-term maintenance of pyloric central pattern generator operation in the rock lobster Homarus gammarus, are members of the commissural pyloric oscillator (CPO), a higher-order oscillator influencing the pyloric network. 2. The CP neuron was endogenously oscillating in approximately 30% of the preparations in which its cell body was impaled. Rhythmic inhibitory feedback from the pyloric pacemaker anterior burster (AB) neuron stabilized the CP neuron's endogenous rhythm. 3. The organization of the CPO is described. Follower commissural neurons, the F cells, and the CP neuron receive a common excitatory postsynaptic potential from another commissural neuron, the large exciter (LE). When in oscillatory state, CP in turn excites the LE neuron. This positive feedback may maintain long episodes of CP oscillations. 4. The pyloric pacemaker neurons follow the CPO rhythm with variable coordination modes (i.e., 1:1, 1:2) and switch among these modes when their membrane potential is modified. The CPO inputs strongly constrain the pyloric period, which as a result may adopt only a few discrete values. This effect is based on mechanisms of entrainment between the CPO and the pyloric oscillator. 5. Pyloric constrictor neurons show differential sensitivity from the pyloric pacemaker neurons with respect to the CPO inputs. Consequently, their bursting period can be a shorter harmonic of the bursting period of the pyloric pacemakers neurons. 6. The CPO neurons seem to be the first example of modulatory gating neurons that also give timing cues to a rhythmic pattern generating network.

The effects of motorway runoff on freshwater ecosystems. 2: Identifying major toxicants

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

Maltby, L.; Boxall, A.B.A.; Forrow, D.M.

1995-06-01

Previous studies have provided prima facie evidence that runoff from the M1 motorway, UK, affects both the quality of the receiving water and the biota living there, in sites short distances from point sources-i.e., possible worst-case situations. Because discharges contain a wide variety of contaminants, both the identification of toxicants and the establishment of causal relationships between observed changes in water/sediment quality and biology are often difficult. In this particular case, the problem was addressed by conducting a series of toxicity tests using the benthic amphipod Gammarus pulex. The abundance of this species was greatly reduced downstream of the pointmore » where motorway runoff entered the stream. Stream water contaminated with motorway runoff was not toxic to G. pulex. However, exposure to contaminated sediments resulted in a slight reduction in survival over 14 d, and sediment manipulation experiments identified hydrocarbons, copper, and zinc as potential toxicants. Spiking experiments confirmed the importance of hydrocarbons, and fractionation studies indicated that most of the observed toxicity was due to the fraction containing polycyclic aromatic hydrocarbons. Animals exposed to contaminated sediments and water spiked with sediment extract accumulated aromatic hydrocarbons in direct proportion to exposure concentrations.« less

Limiting immunopathology: Interaction between carotenoids and enzymatic antioxidant defences.

PubMed

Babin, A; Saciat, C; Teixeira, M; Troussard, J-P; Motreuil, S; Moreau, J; Moret, Y

2015-04-01

The release of reactive oxygen and nitrogen species (ROS and RNS) during the inflammatory response generates damages to host tissues, referred to as immunopathology, and is an important factor in ecological immunology. The integrated antioxidant system, comprising endogenous antioxidant enzymes (e.g. superoxide dismutase SOD, and catalase CAT) and dietary antioxidants (e.g. carotenoids), helps to cope with immune-mediated oxidative stress. Crustaceans store large amounts of dietary carotenoids for yet unclear reasons. While being immunostimulants and antioxidants, the interaction of these pigments with antioxidant enzymes remains unclear. Here, we tested the interaction between dietary supplementation with carotenoids and immune challenge on immune defences and the activity of the antioxidant enzymes SOD and CAT, in the amphipod crustacean Gammarus pulex. Dietary supplementation increased the concentrations of circulating carotenoids and haemocytes in the haemolymph, while the immune response induced the consumption of circulating carotenoids and a drop of haemocyte density. Interestingly, supplemented gammarids exhibited down-regulated SOD activity but high CAT activity compared to control ones. Our study reveals specific interactions of dietary carotenoids with endogenous antioxidant enzymes, and further underlines the potential importance of carotenoids in the evolution of immunity and/or of antioxidant mechanisms in crustaceans. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of lambda-cyhalothrin in two ditch microcosm systems of different trophic status.

PubMed

Roessink, Ivo; Arts, Gertie H P; Belgers, J Dick M; Bransen, Fred; Maund, Steve J; Brock, Theo C M

2005-07-01

The fate and effects of the pyrethroid insecticide lambda-cyhalothrin were compared in mesotrophic (macrophyte-dominated) and eutrophic (phytoplankton-dominated) ditch microcosms (approximately 0.5 m3). Lambda-cyhalothrin was applied three times at one-week intervals at concentrations of 10, 25, 50, 100, and 250 ng/L. The rate of dissipation of lambda-cyhalothrin in the water column of the two types of test systems was similar. After 1 d, only 30% of the amount applied remained in the water phase. Initial, direct effects were observed primarily on arthropod taxa. The most sensitive species was the phantom midge (Chaoborus obscuripes). Threshold levels for slight and transient direct toxic effects were similar (10 ng/L) between types of test systems. At treatment levels of 25 ng/L and higher, apparent population and community responses occurred. At treatments of 100 and 250 ng/L, the rate of recovery of the macroinvertebrate community was lower in the macrophyte-dominated systems, primarily because of a prolonged decline of the amphipod Gammarus pulex. This species occurred at high densities only in the macrophyte-dominated enclosures. Indirect effects (e.g., increase of rotifers and microcrustaceans) were more pronounced in the plankton-dominated test systems, particularly at treatment levels of 25 ng/L and higher.

Temperature rise and parasitic infection interact to increase the impact of an invasive species.

PubMed

Laverty, Ciaran; Brenner, David; McIlwaine, Christopher; Lennon, Jack J; Dick, Jaimie T A; Lucy, Frances E; Christian, Keith A

2017-04-01

Invasive species often detrimentally impact native biota, e.g. through predation, but predicting such impacts is difficult due to multiple and perhaps interacting abiotic and biotic context dependencies. Higher mean and peak temperatures, together with parasites, might influence the impact of predatory invasive host species additively, synergistically or antagonistically. Here, we apply the comparative functional response methodology (relationship between resource consumption rate and resource supply) in one experiment and conduct a second scaled-up mesocosm experiment to assess any differential predatory impacts of the freshwater invasive amphipod Gammarus pulex, when uninfected and infected with the acanthocephalan Echinorhynchus truttae, at three temperatures representative of current and future climate. Individual G. pulex showed Type II predatory functional responses. In both experiments, infection was associated with higher maximum feeding rates, which also increased with increasing temperatures. Additionally, infection interacted with higher temperatures to synergistically elevate functional responses and feeding rates. Parasitic infection also generally increased Q 10 values. We thus suggest that the differential metabolic responses of the host and parasite to increasing temperatures drives the synergy between infection and temperature, elevating feeding rates and thus enhancing the ecological impact of the invader. Copyright © 2017 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Polychaete/amphipod ratio as an indicator of environmental impact related to offshore oil and gas production along the Norwegian continental shelf.

PubMed

Andrade, Hector; Renaud, Paul E

2011-12-01

Benthic faunal data is regularly collected worldwide to assess the ecological quality of marine environments. Recently, there has been renewed interest in developing biological indices able to identify environmental status and potential anthropogenic impacts. In this paper we evaluate the performance of a general polychaete/amphipod ratio along the Norwegian continental shelf as an environmental indicator for offshore oil and gas impacts. Two main trends are apparent: first, a contamination gradient is discernible from where production takes place compared to stations 10,000 m away. Second, the quality of the marine environment has improved over time. These results are consistent with monitoring reports employing a combination of uni- and multi-variate statistics. Thus, we consider this ratio as a relatively simple, useful and potentially cost-effective complement to other more demanding assessment techniques. Because of its strong theoretical basis, it may also be useful for detecting ecological change as a result of other activities. Copyright © 2011 Elsevier Ltd. All rights reserved.

Metal release from contaminated leaf litter and leachate toxicity for the freshwater crustacean Gammarus fossarum.

PubMed

Maunoury-Danger, Florence; Felten, Vincent; Bojic, Clément; Fraysse, Fabrice; Cosin Ponce, Mar; Dedourge-Geffard, Odile; Geffard, Alain; Guérold, François; Danger, Michael

2018-04-01

Industrialization has left large surfaces of contaminated soils, which may act as a source of pollution for contiguous ecosystems, either terrestrial or aquatic. When polluted sites are recolonized by plants, dispersion of leaf litter might represent a non-negligible source of contaminants, especially metals. To evaluate the risks associated to contaminated leaf litter dispersion in aquatic ecosystems, we first measured the dynamics of metal loss from leaf litter during a 48-h experimental leaching. We used aspen (Populus tremula L.), a common tree species on these polluted sites, and collected leaf litter on three polluted sites (settling pond of a former steel mill) and three control sites situated in the same geographic area. Then, toxicity tests were carried out on individuals of a key detritivore species widely used in ecotoxicology tests, Gammarus fossarum (Crustacea, Amphipoda), with uncontaminated and contaminated leaf litter leachates, using a battery of biomarkers selected for their sensitivity to metallic stress. Leaf litters collected on polluted sites exhibited not only significantly higher cadmium and zinc concentrations but also lower lignin contents. All leaf litters released high amounts of chemical elements during the leaching process, especially potassium and magnesium, and, in a lesser extent, phosphorus, calcium, and trace metals (copper, cadmium, and zinc but not lead). Toxicity tests revealed that the most important toxic effects measured on G. fossarum were due to leaf litter leachates by themselves, whatever the origin of litter (from polluted or control sites), confirming the toxicity of such substances, probably due to their high content in phenolic compounds. Small additional toxic effects of leachates from contaminated leaf litters were only evidenced on gammarid lipid peroxidation, indicating that contaminated leaf litter leachates might be slightly more toxic than uncontaminated ones, but in a very reduced manner. Further studies will

Characterisation of myosin heavy chain gene variants in the fast and slow muscle fibres of gammarid amphipods.

PubMed

Whiteley, N M; Magnay, J L; McCleary, S J; Nia, S Khazraee; El Haj, A J; Rock, J

2010-10-01

Recent molecular work has revealed a large diversity of myosin heavy chain (MyHC) gene variants in the abdominal musculature of gammarid amphipods. An unusual truncated MyHC transcript from the loop 1 region (Variant A(3)) was consistently observed in multiple species and populations. The current study aimed to determine whether this MyHC variant is specific to a particular muscle fibre type, as a change in net charge to the loop 1 region of Variant A(3) could be functionally significant. The localisation of different fibre types within the abdominal musculature of several gammarid species revealed that the deep flexor and extensor muscles are fast-twitch muscle fibres. The dorsal superficial muscles were identified as slow fibres and the muscles extrinsic to the pleopods were identified as intermediate fibres. Amplification of loop 1 region mRNA from isolated superficial extensor and deep flexor muscles, and subsequent liquid chromatography and sequence analysis revealed that Variant A(3) was the primary MyHC variant in slow muscles, and the conserved A(1) sequence was the primary variant in fast muscles. The specific role of Variant A(3) in the slow muscles remains to be investigated. 2010 Elsevier Inc. All rights reserved.

Evidence for discrete solar and lunar orientation mechanisms in the beach amphipod, Talitrus saltator Montagu (Crustacea, Amphipoda)

PubMed Central

Ugolini, Alberto; Hoelters, Laura S.; Ciofini, Alice; Pasquali, Vittorio; Wilcockson, David C.

2016-01-01

Animals that use astronomical cues to orientate must make continuous adjustment to account for temporal changes in azimuth caused by Earth’s rotation. For example, the Monarch butterfly possesses a time-compensated sun compass dependent upon a circadian clock in the antennae. The amphipod Talitrus saltator possesses both a sun compass and a moon compass. We reasoned that the time-compensated compass mechanism that enables solar orientation of T. saltator is located in the antennae, as is the case for Monarch butterflies. We examined activity rhythms and orientation of sandhoppers with antennae surgically removed, or unilaterally occluded with black paint. Removing or painting the antennae did not affect daily activity rhythms or competence to orientate using the sun. However, when tested at night these animals were unable to orientate correctly to the moon. We subsequently measured circadian gene expression in the antennae and brain of T. saltator and show the clock genes period and cryptochrome 2 are rhythmically expressed in both tissues, reminiscent of other arthropods known to possess antennal clocks. Together, our behavioural and molecular data suggest that, T. saltator has anatomically discrete lunar and solar orientation apparatus; a sun compass, likely located in the brain and a moon compass in the antennae. PMID:27759059

Evidence for discrete solar and lunar orientation mechanisms in the beach amphipod, Talitrus saltator Montagu (Crustacea, Amphipoda)

NASA Astrophysics Data System (ADS)

Ugolini, Alberto; Hoelters, Laura S.; Ciofini, Alice; Pasquali, Vittorio; Wilcockson, David C.

2016-10-01

Animals that use astronomical cues to orientate must make continuous adjustment to account for temporal changes in azimuth caused by Earth’s rotation. For example, the Monarch butterfly possesses a time-compensated sun compass dependent upon a circadian clock in the antennae. The amphipod Talitrus saltator possesses both a sun compass and a moon compass. We reasoned that the time-compensated compass mechanism that enables solar orientation of T. saltator is located in the antennae, as is the case for Monarch butterflies. We examined activity rhythms and orientation of sandhoppers with antennae surgically removed, or unilaterally occluded with black paint. Removing or painting the antennae did not affect daily activity rhythms or competence to orientate using the sun. However, when tested at night these animals were unable to orientate correctly to the moon. We subsequently measured circadian gene expression in the antennae and brain of T. saltator and show the clock genes period and cryptochrome 2 are rhythmically expressed in both tissues, reminiscent of other arthropods known to possess antennal clocks. Together, our behavioural and molecular data suggest that, T. saltator has anatomically discrete lunar and solar orientation apparatus; a sun compass, likely located in the brain and a moon compass in the antennae.

The mechanisms of morph determination in the amphipod Jassa: implications for the evolution of alternative male phenotypes.

PubMed Central

Kurdziel, Josepha P; Knowles, L Lacey

2002-01-01

The proximal basis for and the maintenance of alternative male reproductive strategies and tactics are generally not understood in most species, despite the occurrence of male polymorphism across many taxa. In the marine amphipod Jassa marmorata, males differ in morphology as well as behaviour. This dimorphism corresponds to two contrasting reproductive strategies: small sneaker males or 'minors', and large fighter males or 'majors'. This study uses quantitative genetic analyses in conjunction with experimental manipulations to assess the relative importance of genetic versus environmental factors in the determination and maintenance of these alternative mating strategies. Heritability analyses indicated the reproductive phenotypes do not reflect genetic differences between dimorphic males. By contrast, morph determination was significantly affected by diet quality. Majors essentially only developed on high-protein diets. Field studies also identified a strong correlation between seasonal shifts in the relative proportions of morphs and changes in food (i.e. phytoplankton) quantity and composition, corroborating that diet cues the switch between alternative reproductive tactics. Moreover, the comparison of major and minor growth trajectories identified a heterochronic shift in maturation times between morphs, indicating that ecological selective pressures, rather than just sexual selection, may be involved in the maintenance of this conditional strategy. PMID:12350261

The mechanisms of morph determination in the amphipod Jassa: implications for the evolution of alternative male phenotypes.

PubMed

Kurdziel, Josepha P; Knowles, L Lacey

2002-09-07

The proximal basis for and the maintenance of alternative male reproductive strategies and tactics are generally not understood in most species, despite the occurrence of male polymorphism across many taxa. In the marine amphipod Jassa marmorata, males differ in morphology as well as behaviour. This dimorphism corresponds to two contrasting reproductive strategies: small sneaker males or 'minors', and large fighter males or 'majors'. This study uses quantitative genetic analyses in conjunction with experimental manipulations to assess the relative importance of genetic versus environmental factors in the determination and maintenance of these alternative mating strategies. Heritability analyses indicated the reproductive phenotypes do not reflect genetic differences between dimorphic males. By contrast, morph determination was significantly affected by diet quality. Majors essentially only developed on high-protein diets. Field studies also identified a strong correlation between seasonal shifts in the relative proportions of morphs and changes in food (i.e. phytoplankton) quantity and composition, corroborating that diet cues the switch between alternative reproductive tactics. Moreover, the comparison of major and minor growth trajectories identified a heterochronic shift in maturation times between morphs, indicating that ecological selective pressures, rather than just sexual selection, may be involved in the maintenance of this conditional strategy.

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

PubMed

Li, Shibin; Wallis, Lindsay K; Ma, Hongbo; Diamond, Stephen A

2014-01-01

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 performed using dynamic light scattering, UV/Vis spectroscopy, and Scanning Electron Microscopy. Large agglomeration and sedimentation (>77%) in LSW was observed after 0.5h. A simulated solar radiation (SSR)-favored surface attachment of nanoparticles was observed, indicating enhanced phototoxicity with the increased attachment. A 96-h median lethal concentration (LC50) of 29.9 mg/L in H. azteca was calculated, with a daily 4-h UV exposure of 2.2 W/m(2). Phototoxicity of nano-TiO₂ under SSR had a 21-fold increase as compared to that under ambient laboratory light. This phototoxicity was also dependent on UV dose, with calculated LC50s around 22.9 (95% CI, 20.5-23.3)Wh/m(2) when exposed to 20 mg/L nano-TiO₂. Also, H. azteca exhibited negative phototaxis in the presence of shelters, indicating that other factors might play a role in environmental systems. Finally, the environmental implications of nano-TiO₂ to benthic organisms were illustrated, emphasizing the importance of various environmental factors in the ultimate phototoxicity. This increased phototoxicity and its complex interactions with various environmental factors suggest further investigations are needed for future risk assessment of photoactive nanomaterials to benthic organisms. © 2013.

Phylogeographic analyses of the pampas cat (Leopardus colocola; Carnivora, Felidae) reveal a complex demographic history

PubMed Central

da Silva Santos, Anelisie; Trigo, Tatiane Campos; de Oliveira, Tadeu Gomes; Silveira, Leandro

2018-01-01

Abstract The pampas cat is a small felid that occurs in open habitats throughout much of South America. Previous studies have revealed intriguing patterns of morphological differentiation and genetic structure among its populations, as well as molecular evidence for hybridization with the closely related L. tigrinus. Here we report phylogeographic analyses encompassing most of its distribution (focusing particularly on Brazilian specimens, which had been poorly sampled in previous studies), using a novel dataset comprising 2,143 bp of the mitogenome, along with previously reported mtDNA sequences. Our data revealed strong population strutucture and supported a west-to-east colonization process in this species’ history. We detected two population expansion events, one older (ca. 200 thousand years ago [kya]) in western South America and another more recent (ca. 60-50 kya) in eastern areas, coinciding with the expansion of savanna environments in Brazil. Analyses including L. tigrinus individuals bearing introgressed mtDNA from L. colocola showed a complete lack of shared haplotypes between species, indicating that their hybridization was ancient. Finally, we observed a close relationship between Brazilian/Uruguayan L. colocola haplotypes and those sampled in L. tigrinus, indicating that their hybridization was likely related to the demographic expansion of L. colocola into eastern South America. PMID:29668017

Diversity and distribution of hyperiid amphipods along a latitudinal transect in the Atlantic Ocean

NASA Astrophysics Data System (ADS)

Burridge, Alice K.; Tump, Marloes; Vonk, Ronald; Goetze, Erica; Peijnenburg, Katja T. C. A.

2017-11-01

As commensals and parasitoids of gelatinous plankton, hyperiid amphipods play unique and important ecological roles in pelagic food webs. Because the diversity and biogeography of this group in oceanic waters is poorly known, we examined diversity and distribution patterns of hyperiids along a basin-scale meridional transect in the Atlantic Ocean (Atlantic Meridional Transect cruise 22). Hyperiids were collected from epipelagic and upper mesopelagic depths at 27 stations between 39°N and 45°S. A total of 70 species in 36 genera and 17 families were identified, the majority of which belonged to the epipelagic Physocephalata infraorder. We observed maximum species and genus richness in the equatorial upwelling region (up to 35 species, 27 genera per station; 7°N-8°S), which appeared largely driven by increased diversity in the superfamily Platysceloidea, as well as a significant and positive relationship between species richness and sea surface temperature. Cluster analyses of hyperiid species assemblages along the transect broadly supported a division into gyral, equatorial, transitional, and subantarctic assemblages, congruent with Longhurst's biogeochemical provinces. Steepest transitions in hyperiid species composition occurred at the southern subtropical convergence zone (34-38°S). The majority of zooplankton groups show maximal diversity in subtropical waters, and our observations of equatorial maxima in species and genus richness for hyperiids suggest that the mechanisms controlling diversity in this group are distinct from other zooplanktonic taxa. These patterns may be driven by the distribution and diversity of gelatinous hosts for hyperiids, which remain poorly characterized at ocean basin scales. The data reported here provide new distributional records for epipelagic and upper mesopelagic hyperiids across six major oceanic provinces in the Atlantic Ocean.

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.

Analysis of bacterial communities associated with the benthic amphipod Diporeia in the Laurentian Great Lakes Basin.

PubMed

Winters, Andrew D; Marsh, Terence L; Brenden, Travis O; Faisal, Mohamed

2015-01-01

Bacterial communities play important roles in the biological functioning of crustaceans, yet little is known about their diversity, structure, and dynamics. This study was conducted to investigate the bacterial communities associated with the benthic amphipod Diporeia, an important component in the Great Lakes foodweb that has been declining over the past 3 decades. In this study, the combination of 16S rRNA gene sequencing and terminal restriction fragment length polymorphism revealed a total of 175 and 138 terminal restriction fragments (T-RFs) in Diporeia samples following treatment with the endonucleases HhaI and MspI, respectively. Relatively abundant and prevalent T-RFs were affiliated with the genera Flavobacterium and Pseudomonas and the class Betaproteobacteria. T-RFs affiliated with the order Rickettsiales were also detected. A significant difference in T-RF presence and abundance (P = 0.035) was detected among profiles generated for Diporeia collected from 4 sites in Lake Michigan. Comparison of profiles generated for Diporeia samples collected in 2 years from lakes Superior and Michigan showed a significant change in diversity for Lake Superior Diporeia but not Lake Michigan Diporeia. Profiles from one Lake Michigan site contained multiple unique T-RFs compared with other Lake Michigan Diporeia profiles, most notably one that represents the genus Methylotenera. This study generated the most extensive list of bacteria associated with Diporeia and sheds useful insights on the microbiome of Great Lakes Diporeia that may help to reveal potential causes of the decline of Diporeia populations.

A new method for early assessment of effects of exposing two non-target crustacean species, Asellus aquaticus and Gammarus fossarum, to pesticides, a laboratory study.

PubMed

Lukancic, Simon; Zibrat, Uros; Mezek, Tadej; Jerebic, Andreja; Simcic, Tatjana; Brancelj, Anton

2010-05-01

A reliable method is needed for assessing the condition of aquatic animals and their resistance to toxic pollutants. The physiological responses of two freshwater crustaceans, Asellus aquaticus and Gammarus fossarum, following in vitro exposure to two pesticides (atrazine and imidacloprid), were measured by a combination of electron transport system (ETS) activity and respiration (R). Short-term exposure concentrations were selected according to standard toxicity tests and ranged from 0.01 mg L(-1) to 10 mg L(-1). When pesticide concentration was greater than 1 mg l(- 1) (which is below the LC(50) [48 hours] determined for both species), A. aquaticus and G. fossarum responded to short-term exposure with elevated levels of R and/or lower levels of ETS activity. One hour exposure to concentrations of up to 10 mg L(-1) showed an effect in both test species. Laboratory tests confirmed that G. fossarum is more sensitive to short-term pesticide exposure than A. aquaticus. The combination of these two methods provides a useful and effective tool for assessing the general condition of aquatic animals. It also enables to determine toxic effects on freshwater biota of specific or combined pollutants. ETS/R ratio may be used as a quick predictor of effects on organisms exposed to pesticides and other stress factors such as changes in temperature, light, salinity, oxygen concentration and food.

Biochemical responses of Gammarus pulex to malachite green solutions decolorized by Coriolus versicolor as a biosorbent under batch adsorption conditions optimized with response surface methodology.

PubMed

Yildirim, Nuran Cikcikoglu; Tanyol, Mehtap; Yildirim, Numan; Serdar, Osman; Tatar, Sule

2018-07-30

The current study was aimed to investigate the detoxifying and antioxidant enzyme response of Gammarus pulex exposed to malachite green (MG) after decolorization by Coriolus versicolor. Response surface methodology (RSM) was utilized to optimize the decolorization conditions of MG synthetic solutions by C. versicolor. Glutathione (GSH), malondialdehyde (MDA) levels and glutathione peroxidase (GP X ), catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), cytochrome P450 1A1 (CYP1A1) activities in G. pulex exposed to undecolorized (A1) and decolorized (A2) MG synthetic solution during 24 and 96 h were tested by using ELISA method. SOD and GP X enzyme activity was increased after decolorization (p > 0.05). CAT enzyme activity was increased in A2 group during 24 h (p > 0.05) but decreased during 96 h (p < 0.05). GSH levels were increased in A2 group during 24 and 96 h (p < 0.05). GST, CYP1A1 enzyme activity and MDA levels were decreased after decolorization during 96 h (p < 0.05). In this study, GSH levels, CAT, GST and CYP1A1 activities in G. pulex approved the capability of C. versicolor in MG decolorization, optimized with RSM. Copyright © 2018 Elsevier Inc. All rights reserved.

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stress proteins hsp60 and hsp70 in three species of amphipods exposed to cadmium, diazinon, dieldrin and fluoranthene

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

Werner, I.; Nagel, R.

1997-11-01

To investigate the use of stress proteins hsp60 and hsp70 as sublethal biomarkers for contaminant exposure in sediments, two infaunal (Ampelisca abdita, estuarine; Rhepoxynius abronius, marine) and one epifaunal (Hyalella azteca, freshwater) amphipod species were exposed for 24 h to solutions of the heavy metal cadmium, the pesticides diazinon and dieldrin, and the polycyclic aromatic hydrocarbon fluoranthene. All three species are routinely used in standard sediment toxicity tests. Analysis of hsp60 and hsp70 was performed using western blotting techniques with subsequent comparative quantification by densitometry. Results demonstrated compound and species-specific induction of stress protein synthesis. Whereas one member of themore » hsp70 protein family showed the most sensitive response to xenobiotic compounds in H. azteca, several members of the hsp60 protein family were the main proteins induced in A. abdita and R. abronius. Sensitivity of the detected stress protein response was highest in H. azteca with significant effects at concentrations 110-, 50-, >1,000-, and >1-fold lower than LC50 values for cadmium, diazinon, dieldrin, and fluoranthene, respectively. The corresponding values were >5 (cadmium), 0.7 (diazinon), >1 (dieldrin), and 2.9 (fluoranthene) for A. abdita, and >2 (cadmium), 3.1 (diazinon), > 100 (dieldrin), and >2.9 (fluoranthene) for R. abronius.« less

Effects of the Veterinary Pharmaceutical Ivermectin in Indoor Aquatic Microcosms

PubMed Central

Boonstra, Harry; Reichman, Erik P.

2010-01-01

The effects of the parasiticide ivermectin were assessed in plankton-dominated indoor microcosms. Ivermectin was applied once at concentrations of 30, 100, 300, 1000, 3000, and 10,000 ng/l. The half-life (dissipation time 50%; DT50) of ivermectin in the water phase ranged from 1.1 to 8.3 days. The lowest NOECcommunity that could be derived on an isolated sampling from the microcosm study by means of multivariate techniques was 100 ng/l. The most sensitive species in the microcosm study were the cladocerans Ceriodaphnia sp. (no observed effect concentration, NOEC = 30 ng/l) and Chydorus sphaericus (NOEC = 100 ng/l). The amphipod Gammarus pulex was less sensitive to ivermectin, showing consistent statistically significant reductions at the 1000-ng/l treatment level. Copepoda taxa decreased directly after application of ivermectin in the highest treatment but had already recovered at day 20 posttreatment. Indirect effects (e.g., increase of rotifers, increased primary production) were observed at the highest treatment level starting only on day 13 of the exposure phase. Cladocera showed the highest sensitivity to ivermectin in both standard laboratory toxicity tests as well as in the microcosm study. This study demonstrates that simple plankton-dominated test systems for assessing the effects of ivermectin can produce results similar to those obtained with large complex outdoor systems. PMID:20422169

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.

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.

Additive effect of calcium depletion and low resource quality on Gammarus fossarum (Crustacea, Amphipoda) life history traits.

PubMed

Rollin, Marc; Coulaud, Romain; Danger, Michael; Sohm, Bénédicte; Flayac, Justine; Bec, Alexandre; Chaumot, Arnaud; Geffard, Olivier; Felten, Vincent

2018-04-01

Gammarus fossarum is an often-abundant crustacean detritivore that contributes importantly to leaf litter breakdown in oligotrophic, mainly heterotrophic, headwater streams. This species requires large amounts of Ca to moult, thus allowing growth and reproduction. Because resource quality is tightly coupled to the organism's growth and physiological status, we hypothesised that low Ca concentration [Ca] and low food resource quality (low phosphorus [P] and/or reduced highly unsaturated fatty acid [HUFA] contents) would interactively impair molecular responses (gene expression) and reproduction of G. fossarum. To investigate the effects of food resources quality, we experimentally manipulated the P content of sycamore leaves and also used diatoms because they contain high amounts of HUFAs. Three resource quality treatments were tested: low quality (LQ, unmanipulated leaves: low P content), high quality 1 (HQ1; P-manipulated leaves: high P content), and high quality 2 (unmanipulated leaves supplemented with a pellet containing diatoms: high P and HUFA content). Naturally, demineralised stream water was supplemented with CaSO 4 to obtain three Ca concentrations (2, 3.5, and 10.5 mg Ca L -1 ). For 21 days, pairs of G. fossarum were individually exposed to one of the nine treatments (3 [Ca] × 3 resource qualities). At the individual level, strong and significant delays in moult stage were observed in gammarids exposed to lower [Ca] and to lower resource quality, with additive effects lengthening the duration of the reproductive cycle. Effects at the molecular level were investigated by measuring expression of 12 genes involved in energy production, translation, or Ca or P homeostasis. Expression of ATP synthase beta (higher in HQ2), calcified cuticle protein (higher in HQ1 and HQ2), and tropomyosin (higher in HQ2 compared to HQ1) was significantly affected by resource quality, and significant additive effects on Ca transporting ATPase expression were induced by

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.

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

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

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 asmore » 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.« less

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

Temporal and spatial variation of hyperiid amphipod assemblages in response to hydrographic processes in the Panama Bight, eastern tropical Pacific

NASA Astrophysics Data System (ADS)

Valencia, Bellineth; Lavaniegos, Bertha; Giraldo, Alan; Rodríguez-Rubio, Efraín

2013-03-01

The variability of hyperiid amphipod assemblages was analyzed based on seasonal (dry vs. wet) and spatial differences (neritic vs. oceanic) in the Panama Bight. Four oceanographic cruises were carried out during 2007-2008, two during the dry season (Feb. 2007 and Mar. 2008) and two during the wet season (Sep. 2007 and Sep. 2008). Cooler (<20 °C) and saltier waters (>34 psu) at 30 m were observed during the dry season, while the opposite pattern occurred during the wet season (>25 °C,<33 psu). Seventy hyperiids species were found, with Hyperioides sibaginis and Lestrigonus bengalensis being the most abundant (76%). The structure of the hyperiids assemblages was similar between seasons; this may be due to the interannual variability associated with two ENSO processes (El Niño: Feb. 2007; La Niña: Sep. 2007 and Mar. 2008). Spatially, the structure of the hyperiids assemblages changed during the wet season, as a consequence of the strong neritic-oceanic contrast in salinity, while it was spatially similar during the dry season, as a consequence of species penetration toward the coast promoted by colder and saltier waters. The abundance of hyperiids was significantly correlated with the abundance of gelatinous zooplankton (siphonophores, ctenophores, doliolids and salps), which are commonly used as hosts by this group.

Chronic toxicity of azoxystrobin to freshwater amphipods, midges, cladocerans, and mussels in water-only exposures

USGS Publications Warehouse

Kunz, James L.; Ingersoll, Christopher G.; Smalling, Kelly; Elskus, Adria; Kuivila, Kathryn

2017-01-01

Understanding the effects of fungicides on nontarget organisms at realistic concentrations and exposure durations is vital for determining potential impacts on aquatic ecosystems. Environmental concentrations of the fungicide azoxystrobin have been reported up to 4.6 μg/L in the United States and 30 μg/L in Europe. The objective of the present study was to evaluate the chronic toxicity of azoxystrobin in water-only exposures with an amphipod (Hyalella azteca; 42-d exposure), a midge (Chironomus dilutus; 50-d exposure), a cladoceran (Ceriodaphnia dubia; 7-d exposure), and a unionid mussel (Lampsilis siliquoidea; 28-d exposure) at environmentally relevant concentrations. The potential photo-enhanced toxicity of azoxystrobin accumulated by C. dubiaand L. siliquoidea following chronic exposures to azoxystrobin was also evaluated. The 20% effect concentrations (EC20s) based on the most sensitive endpoint were 4.2 μg/L for H. aztecareproduction, 12 μg/L for C. dubia reproduction and C. dilutus emergence, and >28 μg/L for L. siliquoidea. Hyalella azteca was more sensitive to azoxystrobin compared with the other 3 species in the chronic exposures. No photo-enhanced toxicity was observed for either C. dubia or L. siliquoidea exposed to ultraviolet light in control water following azoxystrobin tests. The results of the present study indicate chronic effects of azoxystrobin on 3 of 4 invertebrates tested at environmentally relevant concentrations. The changes noted in biomass and reproduction have the potential to alter the rate of ecological processes driven by aquatic invertebrates. Environ Toxicol Chem 2017;9999:1–8. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Chronic toxicity of azoxystrobin to freshwater amphipods, midges, cladocerans, and mussels in water-only exposures.

PubMed

Kunz, James L; Ingersoll, Chris G; Smalling, Kelly L; Elskus, Adria A; Kuivila, Kathryn M

2017-09-01

Understanding the effects of fungicides on nontarget organisms at realistic concentrations and exposure durations is vital for determining potential impacts on aquatic ecosystems. Environmental concentrations of the fungicide azoxystrobin have been reported up to 4.6 μg/L in the United States and 30 μg/L in Europe. The objective of the present study was to evaluate the chronic toxicity of azoxystrobin in water-only exposures with an amphipod (Hyalella azteca; 42-d exposure), a midge (Chironomus dilutus; 50-d exposure), a cladoceran (Ceriodaphnia dubia; 7-d exposure), and a unionid mussel (Lampsilis siliquoidea; 28-d exposure) at environmentally relevant concentrations. The potential photo-enhanced toxicity of azoxystrobin accumulated by C. dubia and L. siliquoidea following chronic exposures to azoxystrobin was also evaluated. The 20% effect concentrations (EC20s) based on the most sensitive endpoint were 4.2 μg/L for H. azteca reproduction, 12 μg/L for C. dubia reproduction and C. dilutus emergence, and >28 μg/L for L. siliquoidea. Hyalella azteca was more sensitive to azoxystrobin compared with the other 3 species in the chronic exposures. No photo-enhanced toxicity was observed for either C. dubia or L. siliquoidea exposed to ultraviolet light in control water following azoxystrobin tests. The results of the present study indicate chronic effects of azoxystrobin on 3 of 4 invertebrates tested at environmentally relevant concentrations. The changes noted in biomass and reproduction have the potential to alter the rate of ecological processes driven by aquatic invertebrates. Environ Toxicol Chem 2017;36:2308-2315. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2017 SETAC.

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Multiple density dependence in two sub-populations of the amphipod Monoporeia affinis: a potential for alternative equilibria.

PubMed

Leonardsson, Kjell

1994-02-01

Possible mechanisms for differences in population densities and dynamics were investigated in the amphipod Monoporeia affinis at two deep sites in the northern Bothnian Sea. The two sites were sampled yearly for 10 years. Average sizes, growth and mortality of the different age-classes were estimated from the cohort structure of the two populations. Laboratory experiments also investigated the ability of the common predatory isopod Saduria entomon to cause densitydependent (DD) mortality of the prey M. affinis. At site A, 43 m depth, the average density of M. affinis was twice as high as at site B, 81 m depth. The fluctuations in density were asynchronous between the two sites. Recruitment and subadult sizes of Monoporeia affinis were density dependent at both sites. The main functional difference between the two populations seemed to be the DD mortality of the 1 + cohort that occurred only at the low-density site B. A corresponding DD mortality was found in the predation experiments at densities of 1 + m. affinis corresponding to those found at site B. The potential importance of the predator was also indicated by a significant negative correlation between the biomass of S. entomon and the rate of change in M. affinis density in the field. The similarities in the abiotic factors between the two sites suggested that differences in carrying capacity should be small. The results could be explained by the predation regulation hypothesis for the low-density population at site B, while at site A M. affinis seemed to be regulated by intra-specific competition and limited by predation. It is suggested that in this simple predator-prey system there is potential for the existence of alternative equilibria.

Identification and temporal expression of putative circadian clock transcripts in the amphipod crustacean Talitrus saltator

PubMed Central

O’Grady, Joseph F.; Hoelters, Laura S.; Swain, Martin T.

2016-01-01

Background Talitrus saltator is an amphipod crustacean that inhabits the supralittoral zone on sandy beaches in the Northeast Atlantic and Mediterranean. T. saltator exhibits endogenous locomotor activity rhythms and time-compensated sun and moon orientation, both of which necessitate at least one chronometric mechanism. Whilst their behaviour is well studied, currently there are no descriptions of the underlying molecular components of a biological clock in this animal, and very few in other crustacean species. Methods We harvested brain tissue from animals expressing robust circadian activity rhythms and used homology cloning and Illumina RNAseq approaches to sequence and identify the core circadian clock and clock-related genes in these samples. We assessed the temporal expression of these genes in time-course samples from rhythmic animals using RNAseq. Results We identified a comprehensive suite of circadian clock gene homologues in T. saltator including the ‘core’ clock genes period (Talper), cryptochrome 2 (Talcry2), timeless (Taltim), clock (Talclk), and bmal1 (Talbmal1). In addition we describe the sequence and putative structures of 23 clock-associated genes including two unusual, extended isoforms of pigment dispersing hormone (Talpdh). We examined time-course RNAseq expression data, derived from tissues harvested from behaviourally rhythmic animals, to reveal rhythmic expression of these genes with approximately circadian period in Talper and Talbmal1. Of the clock-related genes, casein kinase IIβ (TalckIIβ), ebony (Talebony), jetlag (Taljetlag), pigment dispensing hormone (Talpdh), protein phosphatase 1 (Talpp1), shaggy (Talshaggy), sirt1 (Talsirt1), sirt7 (Talsirt7) and supernumerary limbs (Talslimb) show temporal changes in expression. Discussion We report the sequences of principle genes that comprise the circadian clock of T. saltator and highlight the conserved structural and functional domains of their deduced cognate proteins. Our

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.

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.

Recovery of ostracod with known ages in differently textured sediments and comparison of toxicity of heavily contaminated sediments with ostracod Heterocypris incongruens and amphipod Hyalella azteca

NASA Astrophysics Data System (ADS)

Stepanova, N. Yu; Nikitin, O. V.; Latypova, V. Z.; Vybornova, I. B.; Galieva, G. S.; Okunev, R. V.

2018-01-01

The recovery of 1-, 4-, 6,-, and 8-d-old ostracods (Heterocypris incongruens) from sediments with different texture has been evaluated. The recovery of ostracods at all ages has been in agreement with the acceptability criterion of 80% of survival for sediment tests. The recovery of ostracods has turned out to be equal to or more than 80% for sand and silt sediments, respectively. The comparison of survival rates between ostracods and amphipods has shown good convergence in the tests of heavily contaminated sediments (R2=0.75, p<0.05). The sediment quality criteria (TEC) have been exceeded mostly for total petroleum hydrocarbons (100% samples), Cr (100%), Ni (87%), Cu (87%), Pb (47%), and Cd (53%). The content of acid volatile sulfides (AVS) has been significantly higher than that of simultaneously extracted metals (SEM). The obtained results have indicated that, metals (Cu, Zn, Cd, Ni, and Pb) are non-bioavailable. Only one sample has exceeded TEC for PAHs (dibenz[a,h]anthracene). It was observed that, no significant correlation between the effect of toxicity and the chemical content.

Inhibition of multidrug/xenobiotic resistance transporter by MK571 improves dye (Fura 2) accumulation in crustacean tissues from lobster, shrimp, and isopod.

PubMed

Lüders, Ann-Katrin; Saborowski, Reinhard; Bickmeyer, Ulf

2009-09-01

Multidrug/xenobiotic resistance transporters are present in living organisms as a first line defence system against small, potentially harmful molecules from the environment or from internal metabolic reactions. Multidrug resistance associated proteins (MRP) are one type of ATP-Binding-Cassette (ABC) transporters, which also transport dyes such as Fura 2, a calcium chelating fluorescence indicator. The specific MRP inhibitor MK571 was used to investigate the fluorescence intensity of cells in tissues of the brain and the midgut gland of the crustaceans Homarus gammarus (lobster), Crangon crangon (brown shrimp) and Idotea emarginata (isopod) during incubation with Fura 2AM (1 microM). In the presence of the inhibitor MK571 (50 microM), the fluorescence of brain tissue significantly increased in all of the three species. The midgut gland of H. gammarus showed a significant increase of fluorescence, whereas there was no effect in the midgut glands of C. crangon and I. baltica. The half maximal concentration of MK571 was 50 microM as measured in the midgut gland of H. gammarus. In conclusion, MRP transporters are present in the three investigated crustacean nervous systems. Using the midgut glands of the three species, only in H. gammarus MK571 inhibited dye extrusion, indicating species-specific differences of transporter systems, their specificity, or tissue specific expression.

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, Jamie P.; Wang, Ning; Ireland, D. Scott; Mount, David R.; Hockett, J. Russell; 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 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.

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

Miniature circulatory systems: A new exposure system for ecotoxicological effect assessments in riverine organisms.

PubMed

Feiner, Mona; Beggel, Sebastian; Geist, Juergen

2016-11-01

Long-term effect assessments in ecotoxicological investigations are important, yet there is a lack of suitable exposure systems for these experiments that can be used for riverine species. A cost-efficient miniature circulatory system was developed that was evaluated for its applicability in long-term exposures in 2 stream-dwelling species: brown trout (Salmo trutta) and an amphipod (Gammarus roeseli). In an egg-to-fry exposure of S. trutta, the toxicity of 2 reverse osmosis concentrates was investigated as examples. Control hatching rate of yolk sac fry was 75 ± 7% and thus complies with the Organisation for Economic Co-operation and Development validity criterion (≥66%). The reverse osmosis concentrates did not impair the hatching rate in any tested concentration. In G. roeseli, mortality rates remained below 20% during a 21-d cultivation, fulfilling the common validity criterion in ecotoxicological testing. Mortality was significantly lower when the species was fed with conditioned alder leaves instead of an artificial shrimp food. Finally, a toxicity test on G. roeseli using copper as the test substance revealed median lethal concentration (LC50) values of 156 μg/L after 96 h and 99 μg/L after 264 h, which is in line with literature findings using other accepted exposure units. In conclusion, the miniature circulatory system provides a novel and cost-efficient exposure system for long-term investigations on riverine species that may also be applicable for other species of fishes and macroinvertebrates. Environ Toxicol Chem 2016;35:2827-2833. © 2016 SETAC. © 2016 SETAC.

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.

The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions.

PubMed

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.

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

Toxicity and fate of two munitions constituents in spiked sediment exposures with the marine amphipod Eohaustorius estuarius.

PubMed

Rosen, Gunther; Lotufo, Guilherme R

2005-11-01

The lethal toxicity of the explosive compounds 14C-labeled 2,4,6-trinitrotoluene (TNT) and nonradiolabeled hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) to the estuarine amphipod Eohaustorius estuarius was investigated in 10-d spiked sediment exposures. The 10-d median lethal concentration (LC50) was determined using the sum molar initial concentration of TNT, aminodinitrotoluenes (ADNTs), and diaminonitrotoluenes (DANTs), as determined by high-performance liquid chromatography (HPLC), and collectively referred to as HPLC-TNT*. Despite expectations of higher toxicity in sandy sediment (Yaquina Bay [YB], OR, USA) compared to relatively fine-grained sediment (San Diego Bay [SDB], CA, USA), LC50 values were similar: 159 and 125 micromol/kg, for YB and SDB sediments, respectively. When expressed as the sum of TNT and all its degradation products (14C-TNT*), LC50s were approximately two times the corresponding LC50s determined by HPLC. The HPLC-TNT* fraction likely corresponds to the most bioavailable and toxic transformation products. The concentrations of 14C-TNT* in tissues were substantially higher than those for HPLC-TNT*, suggesting that compounds other than TNT and its major aminated transformation products were prevalent. Critical body residues were similar for exposures to SDB (11.7 micromol/kg) and YB sediments (39.4 micromol/kg), despite marked differences in the nature of compounds available for uptake in the exposure media. The critical body residues for E. estuarius are lower than those reported for other aquatic invertebrates (83-172 micromol/kg). Unlike observations for TNT, RDX was only loosely associated with SDB sediment, with near complete recovery of the parent compound by chemical analysis. Exposure to RDX did not result in significant mortality even at the highest measured sediment concentration of 10,800 micromol/kg dry weight, nor tissue concentrations as high as 96 micromol/kg wet weight. The lack of RDX lethal effects in this study is

Occupational allergy to aquarium fish food: red midge larva, freshwater shrimp, and earthworm. A clinical and immunological study.

PubMed

Meseguer Arce, J; Villajos, I M Sánchez-Guerrero; Iraola, V; Carnés, J; Fernández Caldas, E

2013-01-01

Chironomids seem to be the main cause of occupational allergy to aquarium fish food. The aim of this study was to investigate the pattern of occupational sensitization to 3 different arthropod species used as components of aquarium fish food. The study sample comprised 8 workers from a fish food packing department. The control group comprised 40 atopic patients (20 of whom were allergic to mites). We performed prick tests with extracts of red midge larva (Chironomus thummi), freshwater shrimp (Gammarus species), earthworm (Tubifex species), and other arthropod species and a battery of common inhalant allergens. We measured peak expiratory flow rate (PEFR) and specific immunoglobulin (Ig) E and performed a methacholine challenge test, nasal challenge test, and immunoblotting. Cross-reactivity analyses were completed using immunoblotting and CAP inhibition. Prick test results were positive to red midge larvae in 7 patients (87.5%), Gammarus in 5 (62.5%), Tubifex in 3 (37.5%), and mites in 6 (75%). In the mite-allergic controls, 30% had positive prick test results to red midge larvae. PEFR decreased > or = 20% during the packing process in all patients, and in 1 patient it indicated a dual asthmatic response. Methacholine challenge test results were positive in all participants. Nasal challenge tests were performed in 4 patients, and the results were positive. Specific IgE to red midge larvae was detected in 62.5%, Gammarus in 50%, and Tubifex in 16%. Bands of approximately 14-15 kDa and 31 kDa were observed in Gammarus and red midge larvae extracts. Cross-reactivity assays demonstrated that Gammarus totally inhibited red midge larvae, while Tubifex did so partially. Dermatophagoides pteronyssinus showed very low inhibitory capacity. Aquarium fish food arthropods are potent allergens with an elevated prevalence of sensitization and variable degree of crossreactivity. This is the first report of occupational allergy to Tubifex. More data are necessary to identify and

Suprabenthic assemblages from the Capbreton area (SE Bay of Biscay). Faunal recovery after a canyon turbidity disturbance

NASA Astrophysics Data System (ADS)

Frutos, Inmaculada; Sorbe, Jean Claude

2017-12-01

In the Capbreton area, suprabenthic assemblages were sampled with a sledge towed over the bottom, at different sites located within the upper part of a 'gouf-type' canyon (8 hauls between 642 m and 797 m, on the axis of the thalweg or on flat perched flank terraces such as site K), on the northern adjacent open slope (2 hauls between 500 and 567 m) and on the northern adjacent shelf margin (2 hauls between 151 m and 158 m). A multivariate analysis carried on the faunal data discriminated different assemblages in this area: a near-canyon shelf assemblage (55 species, mainly amphipods and decapods; 3496 ind./100 m2, 40% mysids; dominant species: Nyctiphanes couchii, Leptomysis gracilis, Weswoodilla rectirostris, Anchialina agilis, Scopelocheirus hopei and Philocheras bispinosus); an open slope assemblage (111 species, mainly amphipods and isopods; 249 ind./100 m2, 36% amphipods; dominant species: Disconectes phalangium, Munnopsurus atlanticus and Boreomysis arctica); a canyon E assemblage (129 species, mainly amphipods, mysids and cumaceans; 1172 ind./100 m2, 58% amphipods; dominant species: Melphidippa sp. B, Chelator insignis); a canyon E' assemblage (107 species, mainly amphipods and mysids; 507 ind./100 m2, 73% amphipods; dominant species: Cleonardopsis carinata, Bonnierella abyssorum, Rhachotropis caeca and Arcturopsis giardi); and a temporary canyon assemblage at site K (34 species, mainly amphipods and mysids; 899 ind./100 m2, 85% amphipods; dominant species: Tmetomyx similis, Caeconyx caeculus, Nebalia sp. A and Cleonardopsis carinata). Site K was sampled only four months after a turbidity event, detected on sediment cores (18 cm thick Bouma sequence) taken during the same cruise and triggered by the violent storm ('ouragan Martin', wind up to 200 km/h) which affected the French Atlantic coast on 27 December 1999. The corresponding suprabenthic assemblage showed evidence of deep structural changes after this catastrophic event, characterized by relative low

Phylogeography of the sandy beach amphipod Haustorioides japonicus along the Sea of Japan: Paleogeographical signatures of cryptic regional divergences

NASA Astrophysics Data System (ADS)

Takada, Yoshitake; Sakuma, Kay; Fujii, Tetsuo; Kojima, Shigeaki

2018-01-01

Recent findings of genetic breaks within apparently continuous marine populations challenge the traditional vicariance paradigm in population genetics. Such "invisible" boundaries are sometimes associated with potential geographic barriers that have forced divergence of an ancestral population, habitat discontinuities, biogeographic disjunctions due to environmental gradients, or a combination of these factors. To explore the factors that influence the genetic population structure of apparently continuous populations along the Sea of Japan, the sandy beach amphipod Haustorioides japonicus was examined. We sampled a total of 300 individuals of H. japonicus from the coast of Japan, and obtained partial sequences of the mitochondrial COI gene. The sequences from 19 local populations were clustered into five groups (Northwestern Pacific, Northern, Central, Southern Sea of Japan, and East China Sea) based on a spatial genetic mixture analysis and a minimum-spanning network. AMOVA and pairwise Fst tests further supported the significant divergence of the five groups. Phylogenetic analysis revealed the relationship among the haplotypes of H. japonicus and outgroups, which inferred the northward range expansion of the species. A relaxed molecular-clock Bayesian analysis inferred the early-to middle-Pleistocene divergence of the populations. Among the five clusters, the Central Sea of Japan showed the highest values for genetic diversity indices indicating the existence of a relatively stable and large population there. The hypothesis is also supported by Bayesian Skyline Plots that showed sudden population expansion for all the clusters except for Central Sea of Japan. The present study shows genetic boundaries between the Sea of Japan and the neighboring seas, probably due to geographic isolation during the Pleistocene glacial periods. We further found divergence between the populations along the apparently continuous coast of the Sea of Japan. Historical changes in the

Tide-associated biological rhythms of some White Sea littoral invertebrates.

PubMed

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. c2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

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

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.

Wetland use and feeding by lesser scaup during spring migration across the upper Midwest, USA

USGS Publications Warehouse

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

2009-01-01

Low food availability and forage quality and concomitant decreased lipid reserves of lesser scaup (Aythya affinis; hereafter scaup) during spring migration in the upper Midwest may partially explain reductions in the continental population of scaup. In springs 20042005, we examined wetland use and feeding activity of scaup on 356 randomly-selected wetlands within 6 regions in Iowa, Minnesota, and North Dakota. We examined wetland characteristics that favor high scaup use in 286 of these wetlands. We found that probabilities of wetland use and feeding by scaup increased with turbidity up to 45 and 30 NTU, respectively, but then declined at higher turbidity levels. Wetland use was positively correlated with size of open-water zone and amphipod densities, but was not correlated with chironomid densities. Feeding increased with amphipod density up to 26 m-3 and then declined at higher amphipod densities; scaup seemingly forage most efficiently at amphipod densities above 26 m -3. Wetland use was higher in North Dakota than in southern Minnesota and Iowa. Our results indicate that effective wetland restoration efforts to benefit scaup require maintaining abundant populations of amphipods (generally near 26 m-3 landscape geometric mean) in wetlands with large (> 500 m diameter) open-water zones throughout the upper Midwest, but especially within Iowa and southern Minnesota.

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

Active foraging for toxic prey during gestation in a snake with maternal provisioning of sequestered chemical defences.

PubMed

Kojima, Yosuke; Mori, Akira

2015-01-07

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. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

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

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

Coastal ecosystems on a tipping point: Global warming and parasitism combine to alter community structure and function.

PubMed

Mouritsen, Kim N; Sørensen, Mikkel M; Poulin, Robert; Fredensborg, Brian L

2018-05-16

Mounting evidence suggests that the transmission of certain parasites is facilitated by increasing temperatures, causing their host population to decline. However, no study has yet addressed how temperature and parasitism may combine to shape the functional structure of a whole host community in the face of global warming. Here, we apply an outdoor mesocosm approach supported by field surveys to elucidate this question in a diverse intertidal community of amphipods infected by the pathogenic microphallid trematode, Maritrema novaezealandensis. Under present temperature (17°C) and level of parasitism, the parasite had little impact on the host community. However, elevating the temperature to 21°C in the presence of parasites induced massive structural changes: amphipod abundances decreased species-specifically, affecting epibenthic species but leaving infaunal species largely untouched. In effect, species diversity dropped significantly. In contrast, four degree higher temperatures in the absence of parasitism had limited influence on the amphipod community. Further elevating temperatures (19-25°C) and parasitism, simulating a prolonged heat-wave scenario, resulted in an almost complete parasite-induced extermination of the amphipod community at 25°C. In addition, at 19°C, just two degrees above the present average, a similar temperature-parasite synergistic impact on community structure emerged as seen at 21°C under lower parasite pressure. The heat-wave temperature of 25°C per se affected the amphipod community in a comparable way: species diversity declined and the infaunal species were favoured at the expense of epibenthic species. Our experimental findings are corroborated by field data demonstrating a strong negative relationship between current amphipod species richness and the level of Maritrema parasitism across 12 sites. Hence, owing to the synergistic impact of temperature and parasitism, our study predicts that coastal amphipod communities will

Behavioural and biochemical responses to metals tested alone or in mixture (Cd-Cu-Ni-Pb-Zn) in Gammarus fossarum: From a multi-biomarker approach to modelling metal mixture toxicity.

PubMed

Lebrun, Jérémie D; Uher, Emmanuelle; Fechner, Lise C

2017-12-01

Metals are usually present as mixtures at low concentrations in aquatic ecosystems. However, the toxicity and sub-lethal effects of metal mixtures on organisms are still poorly addressed in environmental risk assessment. Here we investigated the biochemical and behavioural responses of Gammarus fossarum to Cu, Cd, Ni, Pb and Zn tested individually or in mixture (M2X) at concentrations twice the levels of environmental quality standards (EQSs) from the European Water Framework Directive. The same metal mixture was also tested with concentrations equivalent to EQSs (M1X), thus in a regulatory context, as EQSs are proposed to protect aquatic biota. For each exposure condition, mortality, locomotion, respiration and enzymatic activities involved in digestive metabolism and moult were monitored over a 120h exposure period. Multi-metric variations were summarized by the integrated biomarker response index (IBR). Mono-metallic exposures shed light on biological alterations occurring at environmental exposure levels in gammarids and depending on the considered metal and gender. As regards mixtures, biomarkers were altered for both M2X and M1X. However, no additive or synergistic effect of metals was observed comparing to mono-metallic exposures. Indeed, bioaccumulation data highlighted competitive interactions between metals in M2X, decreasing subsequently their internalisation and toxicity. IBR values indicated that the health of gammarids was more impacted by M1X than M2X, because of reduced competitions and enhanced uptakes of metals for the mixture at lower, EQS-like concentrations. Models using bioconcentration data obtained from mono-metallic exposures generated successful predictions of global toxicity both for M1X and M2X. We conclude that sub-lethal effects of mixtures identified by the multi-biomarker approach can lead to disturbances in population dynamics of gammarids. Although IBR-based models offer promising lines of enquiry to predict metal mixture toxicity

The effects of parasite age and intensity on variability in acanthocephalan-induced behavioural manipulation.

PubMed

Franceschi, Nathalie; Bauer, Alexandre; Bollache, Loïc; Rigaud, Thierry

2008-08-01

Numerous parasites with complex life cycles are able to manipulate the behaviour of their intermediate host in a way that increases their trophic transmission to the definitive host. Pomphorhynchus laevis, an acanthocephalan parasite, is known to reverse the phototactic behaviour of its amphipod intermediate host, Gammarus pulex, leading to an increased predation by fish hosts. However, levels of behavioural manipulation exhibited by naturally-infected gammarids are extremely variable, with some individuals being strongly manipulated whilst others are almost not affected by infection. To investigate parasite age and parasite intensity as potential sources of this variation, we carried out controlled experimental infections on gammarids using parasites from two different populations. We first determined that parasite intensity increased with exposure dose, but found no relationship between infection and host mortality. Repeated measures confirmed that the parasite alters host behaviour only when it reaches the cystacanth stage which is infective for the definitive host. They also revealed, we believe for the first time, that the older the cystacanth, the more it manipulates its host. The age of the parasite is therefore a major source of variation in parasite manipulation. The number of parasites within a host was also a source of variation. Manipulation was higher in hosts infected by two parasites than in singly infected ones, but above this intensity, manipulation did not increase. Since the development time of the parasite was also different according to parasite intensity (it was longer in doubly infected hosts than in singly infected ones, but did not increase more in multi-infected hosts), individual parasite fitness could depend on the compromise between development time and manipulation efficiency. Finally, the two parasite populations tested induced slightly different degrees of behavioural manipulation.

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

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.

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.

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

Studying the movement behavior of benthic macroinvertebrates with automated video tracking

PubMed Central

Augusiak, Jacqueline; Van den Brink, Paul J

2015-01-01

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

Acute toxicity of fire-retardant and foam-suppressant chemicals to yalella azteca (Saussure)

USGS Publications Warehouse

McDonald, Susan F.; Hamilton, Steven J.; Buhl, Kevin J.; Heisinger, James F.

1997-01-01

Acute toxicity tests were conducted with Hyalella azteca Saussure (an amphipod) exposed in soft and hard waters to three fire retardants (Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F) and two foam suppressants (Phos-Chek WD-881 and Silv-Ex). The chemicals were slightly to moderately toxic to amphipods. The most toxic chemical to amphipods in soft and hard water was Phos-Chek WD-881 (96-h mean lethal concentration [LC50] equal to 10 mg/L and 22 mg/L, respectively), and the least toxic chemical to amphipods in soft water was Fire-Trol GTS-R (96-h LC50 equal to 127 mg/L) and in hard water was Fire-Trol LCG-R (96-h LC50 equal to 535 mg/L). Concentrations of ammonia in tests with the three fire retardants and both water types were greater than reported LC50 values and probably were the major toxic component. Estimated un-ionized ammonia concentrations near the LC50 were frequently less than the reported LC50 ammonia concentrations for amphipods. The three fire retardants were more toxic in soft water than in hard water even though ammonia and un-ionized ammonia concentrations were higher in hard water tests than in soft water tests. The accidental entry of fire-fighting chemicals into aquatic environments could adversely affect aquatic invertebrates, thereby disrupting ecosystem function.

Effects of 2 fungicide formulations on microbial and macroinvertebrate leaf decomposition under laboratory conditions

USGS Publications Warehouse

Elskus, Adria; Smalling, Kelly L.; Hladik, Michelle; Kuivila, Kathryn

2016-01-01

Aquatic fungi contribute significantly to the decomposition of leaves in streams, a key ecosystem service. However, little is known about the effects of fungicides on aquatic fungi and macroinvertebrates involved with leaf decomposition. Red maple (Acer rubrum) leaves were conditioned in a stream to acquire microbes (bacteria and fungi), or leached in tap water (unconditioned) to simulate potential reduction of microbial biomass by fungicides. Conditioned leaves were exposed to fungicide formulations QUILT (azoxystrobin + propiconazole) or PRISTINE (boscalid + pyraclostrobin), in the presence and absence of the leaf shredder, Hyalella azteca (amphipods; 7-d old at start of exposures) for 14 d at 23 °C. QUILT formulation (~ 0.3 μg/L, 1.8 μg/L, 8 μg/L) tended to increase leaf decomposition by amphipods (not significant) without a concomitant increase in amphipod biomass, indicating potential increased consumption of leaves with reduced nutritional value. PRISTINE formulation (~ 33 μg/L) significantly reduced amphipod growth and biomass (p<0.05), effects similar to those observed with unconditioned controls. The significant suppressive effects of PRISTINE on amphipod growth, and the trend towards increased leaf decomposition with increasing QUILT concentration, indicate the potential for altered leaf decay in streams exposed to fungicides. Further work is needed to evaluate fungicide effects on leaf decomposition under conditions relevant to stream ecosystems, including temperature shifts and pulsed exposures to pesticide mixtures.

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

Calculation and evaluation of sediment effect concentrations for the amphipod Hyalella azteca and the midge Chironomus riparius

USGS Publications Warehouse

Ingersoll, Christopher G.; Haverland, Pamela S.; Brunson, Eric L.; Canfield, Timothy J.; Dwyer, F. James; Henke, Chris; Kemble, Nile E.; Mount, David R.; Fox, Richard G.

1996-01-01

Procedures are described for calculating and evaluating sediment effect concentrations (SECs) using laboratory data on the toxicity of contaminants associated with field-collected sediment to the amphipod Hyalella azteca and the midge Chironomus riparius. SECs are defined as the concentrations of individual contaminants in sediment below which toxicity is rarely observed and above which toxicity is frequently observed. The objective of the present study was to develop SECs to classify toxicity data for Great Lake sediment samples tested with Hyalella azteca and Chironomus riparius. This SEC database included samples from additional sites across the United States in order to make the database as robust as possible. Three types of SECs were calculated from these data: (1) Effect Range Low (ERL) and Effect Range Median (ERM), (2) Threshold Effect Level (TEL) and Probable Effect Level (PEL), and (3) No Effect Concentration (NEC). We were able to calculate SECs primarily for total metals, simultaneously extracted metals, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The ranges of concentrations in sediment were too narrow in our database to adequately evaluate SECs for butyltins, methyl mercury, polychlorinated dioxins and furans, or chlorinated pesticides. About 60 to 80% of the sediment samples in the database are correctly classified as toxic or not toxic depending on type of SEC evaluated. ERMs and ERLs are generally as reliable as paired PELs and TELs at classifying both toxic and non-toxic samples in our database. Reliability of the SECs in terms of correctly classifying sediment samples is similar between ERMs and NECs; however, ERMs minimize Type I error (false positives) relative to ERLs and minimize Type II error (false negatives) relative to NECs. Correct classification of samples can be improved by using only the most reliable individual SECs for chemicals (i.e., those with a higher percentage of correct classification). SECs

Direct and indirect effects of predation by Saduria entomon (Isopoda) on the size-structure of Monoporeia affinis (Amphipoda).

PubMed

Sparrevik, Erik; Leonardsson, Kjell

1999-07-01

We performed a 6-month laboratory experiment to investigate the direct and indirect effects of predation by the benthic invertebrate predator Saduria entomon on the growth and survival of Monopreia affinis prey individuals in different age-cohorts at low and high prey densities. The experimental results were compared with changes of growth and abundance in corresponding age-cohorts of M. affinis at sites with different S. entomon and M. affinis densities in the deep sublittoral zone of the Bothnian Sea during the same year. In the experiment, the presence of S. entomon reduced growth rate of M. affinis in the 1-year and 2-year age-cohorts at low amphipod density. Increased refuge use by M. affinis, expressed as a decrease in swimming activity in the presence of S. entomon, is suggested to have reduced feeding rate and therefore growth of the amphipods. The recruitment of M. affinis offspring was reduced in presence of S. entomon. In the field, the growth rate of amphipods in the 1-year cohort increased with increasing S. entomon density at low amphipod density. We found no corresponding increase of M. affinis growth in the 2-year cohort. The positive effect on 1-year amphipod growth indicated that predation reduced intra-cohort competition of M. affinis and increased growth of surviving prey at high predator density. In both the experiment and the field data we found indications of size-selective predation on smaller M. affinis specimens. This was because of the changed ratio between number of individuals in the juvenile age-cohorts and lower recruitment of amphipod offspring connected to S. entomon density. The experimental results and field data suggest that predation by S. entomon may have both direct and indirect effects on the size-structure of M. affinis populations.

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

Sediment quality assessment using survival and embryo malformation tests in amphipod crustaceans: The Gulf of Riga, Baltic Sea AS case study

NASA Astrophysics Data System (ADS)

Strode, Evita; Jansons, Mintauts; Purina, Ingrida; Balode, Maija; Berezina, Nadezhda A.

2017-08-01

The aim of this study was to assess the toxicity of bottom sediment and to estimate the potential effects of contaminated sediment on health of benthic organisms in the Gulf of Riga (eastern Baltic Sea). Two endpoints were used: survival rate (acute toxicity test) of five crustacean amphipod species and frequency of embryo malformation (samples were collected from the field) in the two species. Toxic resistance of living animals to sediment quality was measured as survival rate (%) at 25 study sites from 2010-2012. Significant differences in the toxic resistance between species were found: 80-100% for Monoporeia affinis, 70-95% for Corophium volutator, 38-88% for Pontogammarus robustoides, 38-100% for Bathyporeia pilosa and 60-100% for Hyalella azteca. Reproductive disorders, measured as percentage (%) of malformed embryos per female, varied in the ranges of 0.0-9.5% in deep water species M. affinis and 0.3-7.5% in littoral species P. robustoides. Both the acute toxicity test and embryo malformation test (only M. affinis was used) indicated moderate and poor sediment quality at 20% and 12% accordingly in the study sites, low toxicity of sediment was estimated in 64% of cases, and no toxicity was recorded in the rest of the cases (4%). Additionally, sediment toxicity test using aquatic organisms was combined with sediment chemical analysis (trace metals) and the Benthic Quality Index (macrozoobenthos) was based on data collected from 13 sites in the Gulf of Riga in 2010 and used for triad sediment quality assessment. According to this combined approach, 23% of the bottom sediments were classified as likely impacted and 23% as possibly impacted (central and southern part of the Gulf). However, the remaining 54% was identified as likely un-impacted. The sediment quality assessment with single survival test or chemical analyses showed better sediment quality in the Gulf than the triad method. The embryo malformation test appeared to be more sensitive to pollution than

An investigation of enhanced mercury bioaccumulation in fish from offshore feeding.

PubMed

Chételat, John; Cloutier, Louise; Amyot, Marc

2013-08-01

We investigated the dietary pathways of mercury transfer in the food web of Morency Lake (Canada) to determine the influence of carbon source and habitat use on mercury bioaccumulation in fish. Whole-body concentrations of methylmercury (MeHg) were significantly different in four fish species (white sucker, brown bullhead, pumpkinseed and smallmouth bass) and increased with both trophic position and greater feeding on offshore (versus littoral) carbon. An examination of fish gut contents and the depth distribution of invertebrates in Morency Lake showed that smallmouth bass and brown bullhead were supplementing their littoral diet with the consumption of either opossum shrimp (Mysis diluviana) or profundal amphipods in offshore waters. The zooplanktivore Mysis had significantly higher MeHg concentrations than zooplankton and benthic invertebrates, and it was an elevated source of MeHg to smallmouth bass. In contrast, profundal amphipods consumed by brown bullhead did not have higher MeHg concentrations than littoral amphipods. Instead, partitioning of benthic invertebrate resources likely explains the greater MeHg bioaccumulation in brown bullhead, associated with offshore feeding of amphipods. White sucker and brown bullhead had a similar trophic position but white sucker consumed more chironomids, which had one-third the MeHg concentration of amphipods. Our findings suggest that offshore feeding in a lake can affect fish MeHg bioaccumulation via two different processes: (1) the consumption of MeHg-enriched pelagic prey, or (2) resource partitioning of benthic primary consumers with different MeHg concentrations. These observations on the mechanisms of habitat-specific bioaccumulation highlight the complexity of MeHg transfer through lake food webs.

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. Thomas; 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

[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.

Ecological impacts of lead mining on Ozark streams: toxicity of sediment and pore water.

PubMed

Besser, John M; Brumbaugh, William G; Allert, Ann L; Poulton, Barry C; Schmitt, Christopher J; Ingersoll, Christopher G

2009-02-01

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.

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.

Comparison of Faunal Scavenging of Submerged Carrion in Two Seasons at a Depth of 170 m, in the Strait of Georgia, British Columbia

PubMed Central

Anderson, Gail S.; Bell, Lynne S.

2017-01-01

The taphonomy of carcasses submerged in the ocean is little understood, yet it is extremely important ecologically and forensically. The objectives of this study were to determine the fate of pig carcasses as human proxies in the Strait of Georgia at 170 m in spring and fall. Using Ocean Networks Canada’s Victoria Experimental Network Underseas (VENUS) observatory, two carcasses per season were placed under a cabled platform hosting a webcam and instruments measuring water chemistry. Two minutes of video were recorded every 15 min. In spring, Lyssianassidae amphipods and Pandalus platyceros were immediately attracted and fed on the carcasses, the amphipods removed the bulk of the soft tissue from the inside whilst the shrimp shredded the skin and tissue. The carcasses were skeletonized on Days 8 and 10. In fall, Metacarcinus magister was the major scavenger, removing most of the soft tissue from one carcass. Amphipods did not arrive in large numbers until Day 15, when they skeletonized the scavenged carcass by Day 22 and the less scavenged carcass by Day 24. Amphipods remained for some days after skeletonization. This skeletonization was very different from previous experiments at different depths and habitats. Such data are very valuable for predicting preservation, planning recoveries, and managing family expectations. PMID:28335403

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, and perhaps in some areas >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

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

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

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

1995-11-01

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

Light pollution reduces activity, food consumption and growth rates in a sandy beach invertebrate.

PubMed

Luarte, T; Bonta, C C; Silva-Rodriguez, E A; Quijón, P A; Miranda, C; Farias, A A; Duarte, C

2016-11-01

The continued growth of human activity and infrastructure has translated into a widespread increase in light pollution. Natural daylight and moonlight cycles play a fundamental role for many organisms and ecological processes, so an increase in light pollution may have profound effects on communities and ecosystem services. Studies assessing ecological light pollution (ELP) effects on sandy beach organisms have lagged behind the study of other sources of disturbance. Hence, we assessed the influence of this stressor on locomotor activity, foraging behavior, absorption efficiency and growth rate of adults of the talitrid amphipod Orchestoidea tuberculata. In the field, an artificial light system was assembled to assess the local influence of artificial light conditions on the amphipod's locomotor activity and use of food patches in comparison to natural (ambient) conditions. Meanwhile in the laboratory, two experimental chambers were set to assess amphipod locomotor activity, consumption rates, absorption efficiency and growth under artificial light in comparison to natural light-dark cycles. Our results indicate that artificial light have significantly adverse effects on the activity patterns and foraging behavior of the amphipods, resulting on reduced consumption and growth rates. Given the steady increase in artificial light pollution here and elsewhere, sandy beach communities could be negatively affected, with unexpected consequences for the whole ecosystem. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

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.

Impaired ecosystem process despite little effects on populations: modeling combined effects of warming and toxicants.

PubMed

Galic, Nika; Grimm, Volker; Forbes, Valery E

2017-08-01

Freshwater ecosystems are exposed to many stressors, including toxic chemicals and global warming, which can impair, separately or in combination, important processes in organisms and hence higher levels of organization. Investigating combined effects of warming and toxicants has been a topic of little research, but neglecting their combined effects may seriously misguide management efforts. To explore how toxic chemicals and warming, alone and in combination, propagate across levels of biological organization, including a key ecosystem process, we developed an individual-based model (IBM) of a freshwater amphipod detritivore, Gammarus pseudolimnaeus, feeding on leaf litter. In this IBM, life history emerges from the individuals' energy budgets. We quantified, in different warming scenarios (+1-+4 °C), the effects of hypothetical toxicants on suborganismal processes, including feeding, somatic and maturity maintenance, growth, and reproduction. Warming reduced mean adult body sizes and population abundance and biomass, but only in the warmest scenarios. Leaf litter processing, a key contributor to ecosystem functioning and service delivery in streams, was consistently enhanced by warming, through strengthened interaction between the detritivorous consumer and its resource. Toxicant effects on feeding and maintenance resulted in initially small adverse effects on consumers, but ultimately led to population extinction and loss of ecosystem process. Warming in combination with toxicants had little effect at the individual and population levels, but ecosystem process was impaired in the warmer scenarios. Our results suggest that exposure to the same amount of toxicants can disproportionately compromise ecosystem processing depending on global warming scenarios; for example, reducing organismal feeding rates by 50% will reduce resource processing by 50% in current temperature conditions, but by up to 200% with warming of 4 °C. Our study has implications for

Pathways of CH3Hg and Hg Ingestion in Benthic Organisms: An Enriched Isotope Approach

PubMed Central

2015-01-01

Mercury is a widespread contaminant in marine food webs, and identifying uptake pathways of mercury species, CH3Hg+ and Hg2+, into low trophic level organisms is important to understanding its entry into marine food webs. Enriched stable isotope tracers were used to study benthic vs. pelagic pathways of CH3Hg+ and Hg2+ uptake via food to the infaunal estuarine amphipod, Leptocheirus plumulosus. Algal cells differentially labeled with isotopically enriched CH3Hg+ or Hg2+ were added simultaneously to the sediment and water column of microcosms, and Hg species were monitored in amphipods and in sediment and water compartments. Methylation of Hg2+ occurred during the course of the experiment, enhancing the uptake of Hg2+ spikes. Trophic transfer of Hg from algae added to the water column was determined to be the major uptake route for amphipods, suggesting inputs of contaminated organic matter from the pelagic zone are important to mercury bioaccumulation even in organisms living in sediments. PMID:24678910

Pathways of CH3Hg and Hg ingestion in benthic organisms: an enriched isotope approach.

PubMed

Taylor, Vivien F; Bugge, Deenie; Jackson, Brian P; Chen, Celia Y

2014-05-06

Mercury is a widespread contaminant in marine food webs, and identifying uptake pathways of mercury species, CH3Hg(+) and Hg(2+), into low trophic level organisms is important to understanding its entry into marine food webs. Enriched stable isotope tracers were used to study benthic vs. pelagic pathways of CH3Hg(+) and Hg(2+) uptake via food to the infaunal estuarine amphipod, Leptocheirus plumulosus. Algal cells differentially labeled with isotopically enriched CH3Hg(+) or Hg(2+) were added simultaneously to the sediment and water column of microcosms, and Hg species were monitored in amphipods and in sediment and water compartments. Methylation of Hg(2+) occurred during the course of the experiment, enhancing the uptake of Hg(2+) spikes. Trophic transfer of Hg from algae added to the water column was determined to be the major uptake route for amphipods, suggesting inputs of contaminated organic matter from the pelagic zone are important to mercury bioaccumulation even in organisms living in sediments.

Toxicity of Aqueous Filmforming Foams to Marine Organisms: Literature Review and Biological Assessment

DTIC Science & Technology

1985-07-01

mg/l)* Scud (Gammarus fasciatus) 1100 mg/l (840-1300 mg/l)* Algae - FC-203 concentrations 򒮨 mg/I did not prevent the growth of Chlorella ...gairdneri) 1800 mg/l Static Test Marine Organisms 96-Hr. LC 5 0 Mummichog (Fundulus heteroclitus) 1820 mg/l Static Test Grass shrimp (Palaemonetes vulgaris

Ecotoxicity hazard assessment of styrene.

PubMed

Cushman, J R; Rausina, G A; Cruzan, G; Gilbert, J; Williams, E; Harrass, M C; Sousa, J V; Putt, A E; Garvey, N A; St Laurent, J P; Hoberg, J R; Machado, M W

1997-07-01

The ecotoxicity of styrene was evaluated in acute toxicity studies of fathead minnows (Pimephales promelas), daphnids (Daphnia magna), amphipods (Hyalella azteca), and freshwater green algae (Selenastrum capricornutum), and a subacute toxicity study of earthworms (Eisenia fostida). Stable exposure levels were maintained in the studies with fathead minnows, daphnids, and amphipods using sealed, flowthrough, serial dilution systems and test vessels. The algae were evaluated in a sealed, static system. The earthworms were exposed in artificial soil which was renewed after 7 days. Styrene concentrations in water and soil were analyzed by gas chromatography with flame ionization detection following extraction into hexane. Test results are based on measured concentrations. Styrene was moderately toxic to fathead minnows, daphnids, and amphipods: fathead minnow: LC50 (96 hr), 10 mg/liter, and NOEC, 4.0 mg/liter; daphnids: EC50 (48 hr), 4.7 mg/liter, and NOEC, 1.9 mg/liter; amphipods: LC50 (96 hr), 9.5 mg/liter, and NOEC, 4.1 mg/liter. Styrene was highly toxic to green algae: EC50 (96 hr), 0.72 mg/liter, and NOEC, 0.063 mg/liter; these effects were found to be algistatic rather than algicidal. Styrene was slightly toxic to earthworms: LC50 (14 days), 120 mg/kg, and NOEC, 44 mg/kg. There was no indication of a concern for chronic toxicity based on these studies. Styrene's potential impact on aquatic and soil environments is significantly mitigated by its volatility and biodegradability.

The mitochondrial genome of the Japanese skeleton shrimp Caprella mutica (Amphipoda: Caprellidea) reveals a unique gene order and shared apomorphic translocations with Gammaridea.

PubMed

Kilpert, Fabian; Podsiadlowski, Lars

2010-06-01

This study presents the complete mitochondrial (mt) genome of the amphipod Caprella mutica, an east-Asian species, which recently invaded the coastal regions of North America, Europe, and New Zealand. It is the first complete sequence of a member of the amphipod subclade Caprellidea. The mt genome has a total length of 15,427 bp and is organized in a circular double-strand molecule. All 37 mt genes are present, including the common set of 22 tRNAs. Particularly noticeable is the duplication of the control region (CR). The additional CR is located between nad6 and cob, and is almost identical to the original one. The most extensive changes in the gene order affect nad5 and a block consisting of trnH, nad4, nad4L, and trnP-all inserted near the original CR. The gene nad5 is also inverted. Furthermore, a comparison with the pancrustacean ground pattern reveals additional changes of individual tRNA genes. Some of these changes are also shared by Metacrangonyx longipes and Parhyale hawaiensis. These arrangements were found only in amphipods and might be considered as apomorphic by character states of Amphipoda. In all the three species, there is good evidence that trnG originated from a rare duplication/remolding event of the adjacent trnW gene. Nevertheless, each of the three available amphipod mitogenome sequences also bears unique rearrangements. C. mutica, however, shows the most extensive rearrangement in comparison with the pancrustacean ground pattern.

Predicting the variation in Echinogammarus marinus at its southernmost limits under global warming scenarios: can the sex-ratio make a difference?

PubMed

Guerra, Alexandra; Leite, Nuno; Marques, João Carlos; Ford, Alex T; Martins, Irene

2014-01-01

Understanding the environmental parameters that constrain the distribution of a species at its latitudinal extremes is critical for predicting how ecosystems react to climate change. Our first aim was to predict the variation in the amphipod populations of Echinogammarus marinus from the southernmost limit of its distribution under global warming scenarios. Our second aim was to test whether sex-ratio fluctuations - a mechanism frequently displayed by amphipods - respond to the variations in populations under altered climate conditions. To achieve these aims, scenarios were run with a validated model of E. marinus populations. Simulations were divided into: phase I - simulation of the effect of climate change on amphipod populations, and phase II - simulation of the effect of climate change on populations with male and female proportions. In both phases, temperature (T), salinity (S) and temperature and salinity (T-S) were tested. Results showed that E. marinus populations are highly sensitive to increases in temperature (>2 °C), which has adverse effects on amphipod recruitment and growth. Results from the climate change scenarios coupled with the sex-ratio fluctuations depended largely on the degree of female bias within population. Temperature increase of 2 °C had less impact on female-biased populations, particularly when conjugated with increases in salinity. Male-biased populations were highly sensitive to any variation in temperature and/or salinity; these populations exhibited a long-term decline in density. Simulations in which temperature increased more than 4 °C led to a continuous decline in the E. marinus population. According to this work, E. marinus populations at their southernmost limit are vulnerable to global warming. We anticipate that in Europe, temperature increases of 2 °C will incite a withdrawal of the population of 5°N from the amphipod species located at southernmost geographical borders. This effect is discussed in relation to the

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

A snap shot of the short-term response of crustaceans to macrophyte detritus in the deep Oslofjord.

PubMed

Ramirez-Llodra, Eva; Rinde, Eli; Gundersen, Hege; Christie, Hartvig; Fagerli, Camilla With; Fredriksen, Stein; Gitmark, Janne Kim; Norling, Karl; Walday, Mats Gunnar; Norderhaug, Kjell Magnus

2016-03-30

A test deployment of a time-lapse camera lander in the deep Oslofjord (431 m) was used to obtain initial information on the response of benthic fauna to macroalgal debris. Three macroalgal species were used on the lander baited plate: Fucus serratus, Saccharina latissima and Laminaria hyperborea and observed during 41.5 hours. The deep-water shrimp Pandalus borealis were attracted to the macroalgae rapidly (3 min after the lander reached the seafloor), followed by amphipods. Shrimp abundances were significantly higher in areas covered by macroalgae compared to the adjacent seafloor and the number of shrimp visiting the macroalgae increased with time. Amphipods arrived 13 hours later and were observed mainly on decaying L. hyperborea. The abundance of amphipods on L. hyperborea increased rapidly, reaching a peak at 31 h after deployment. These initial observations suggest that debris from kelp forests and other macroalgal beds may play an important role in fuelling deep benthic communities in the outer Oslofjord and, potentially, enhance secondary production of commercial species such as P. borealis.

Paratenic hosts as regular transmission route in the acanthocephalan Pomphorhynchus laevis: potential implications for food webs

NASA Astrophysics Data System (ADS)

Médoc, Vincent; Rigaud, Thierry; Motreuil, Sébastien; Perrot-Minnot, Marie-Jeanne; Bollache, Loïc

2011-10-01

Although trophically transmitted parasites are recognized to strongly influence food-web dynamics through their ability to manipulate host phenotype, our knowledge of their host spectrum is often imperfect. This is particularly true for the facultative paratenic hosts, which receive little interest. We investigated the occurrence and significance both in terms of ecology and evolution of paratenic hosts in the life cycle of the fish acanthocephalan Pomphorhynchus laevis. This freshwater parasite uses amphipods as intermediate hosts and cyprinids and salmonids as definitive hosts. Within a cohort of parasite larvae, usually reported in amphipod intermediate hosts, more than 90% were actually hosted by small-sized fish. We demonstrated experimentally, using one of these fish, that they get infected through the consumption of parasitized amphipods and contribute to the parasite's transmission to a definitive host, hence confirming their paratenic host status. A better knowledge of paratenic host spectrums could help us to understand the fine tuning of transmission strategies, to better estimate parasite biomass, and could improve our perception of parasite subwebs in terms of host-parasite and predator-parasite links.

40 CFR 799.3300 - Unsubstituted phenylenediamines.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Acute flow-through studies on the freshwater invertebrate Gammarus shall be conducted with o-, m-, and p... aquatic invertebrates, the ratio of 24 hour/96 hour LC50s is greater than or equal to 2; for gammarids... section. Testing shall be conducted in accordance with § 797.1600 of this chapter. (B) An invertebrate...

Lack of transmission of Hematodinium sp. in the blue crab Callinectes sapidus through cannibalism.

PubMed

Li, Caiwen; Wheeler, Kersten N; Shields, Jeffrey D

2011-10-06

Hematodinium spp. are parasitic dinoflagellates of marine crustaceans. Outbreaks of Hematodinium sp. have impacted commercial landings of the blue crab Callinectes sapidus in the coastal bays of Virginia and Maryland (USA), with seasonal peaks in prevalence reaching 85%. The life cycle and transmission routes of the parasite in blue crabs are poorly understood. Cannibalism and waterborne transmission may be routes of transmission, although little conclusive evidence has been reported for these modes. We examined cannibalism as a route by a series of experiments wherein we repeatedly fed adult and juvenile crabs the tissues of crabs infected with Hematodinium. In each experiment, feeding was done 3 times over the course of 1 wk. Only 2 of 120 crabs were infected within 7 to 9 d after feeding, and these 2 were likely infected prior to the experimental exposures. Crabs inoculated with hemolymph from infected donors served as positive controls. They developed infections over 11 to 21 d, indicating that the Hematodinium sp. used in the cannibalism trials was infectious at the time of inoculation. Because amphipods also harbor Hematodinium-like infections, we fed tissues of infected crabs to the estuarine amphipod Leptocheirus plumulosus. Hematodinium DNA was detected in amphipods shortly after feeding, but not in animals held for longer periods, nor was it observed in histological preparations. Amphipods did not obtain infections by scavenging infected crab tissues. Our results show that Hematodinium sp. is not effectively transmitted through ingestion of diseased tissues, indicating that cannibalism may not be a major route of transmission for Hematodinium sp. in blue crabs.

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.

Species richness and distributions of boreal waterbirds in relation to nesting and brood-rearing habitats

USGS Publications Warehouse

Lewis, Tyler L.; Lindberg, Mark S.; Schmutz, Joel A.; Bertram, Mark R.; Dubour, Adam J.

2015-01-01

Identification of ecological factors that drive animal distributions allows us to understand why distributions vary temporally and spatially, and to develop models to predict future changes to populations–vital tools for effective wildlife management and conservation. For waterbird broods in the boreal forest, distributions are likely driven by factors affecting quality of nesting and brood-rearing habitats, and the influence of these factors may extend beyond singles species, affecting the entire waterbird community. We used occupancy models to assess factors influencing species richness of waterbird broods on 72 boreal lakes, along with brood distributions of 3 species of conservation concern: lesser scaup (Aythya affinis), white-winged scoters (Melanitta fusca), and horned grebe (Podiceps auritus). Factors examined included abundance of invertebrate foods (Amphipoda, Diptera, Gastropoda, Hemiptera, Odonata), physical lake attributes (lake area, emergent vegetation), water chemistry (nitrogen, phosphorus, chlorophyll a concentrations), and nesting habitats (water edge, non-forest cover). Of the 5 invertebrates, only amphipod density was related to richness and occupancy, consistently having a large and positive relationship. Despite this importance to waterbirds, amphipods were the most patchily distributed invertebrate, with 17% of the study lakes containing 70% of collected amphipods. Lake area was the only other covariate that strongly and positively influenced species richness and occupancy of scaup, scoters, and grebes. All 3 water chemistry covariates, which provided alternative measures of lake productivity, were positively related to species richness but had little effect on scaup, scoter, and grebe occupancy. Conversely, emergent vegetation was negatively related to richness, reflecting avoidance of overgrown lakes by broods. Finally, nesting habitats had no influence on richness and occupancy, indicating that, at a broad spatial scale, brood

Optimization of Hyalella azteca IQ Toxicity Test{trademark} for prediction of 28-day sediment toxicity tests

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

Novotny, A.N.; Ezzard, C.L.; Douglas, W.S.

1995-12-31

The IQ Toxicity Test, which is a rapid screening toxicity test consisting of the observation of in-vivo inhibition of an enzymatic process using a fluorescent substrate, has proven successful for the determination of 24 and 48-hour EC50`s of D. magna, C. dubia, D. pulex and M. bahia. The application of this concept to utilize the freshwater amphipod Hyalella azteca may be an excellent way in which to reduce the standard 28-day chronic sediment toxicity test to possibly one hour`s time. This study incorporates an additive experimental design to explore the effects of and interactions between five specific variables: size ofmore » the amphipod, exposure time to the toxicant, concentration of substrate, exposure time to the substrate, and length of time starved prior to testing. The results of the IQ toxicity test were compared to those of a 28-day chronic sediment toxicity test. Preliminary data indicate that there is an optimal combination of these variables which results in a concise, reproducible toxicity test for use with Hyalella azteca, and would potentially be applicable to other freshwater amphipods in the future.« less

Effects of triclosan on marine benthic and epibenthic organisms.

PubMed

Perron, Monique M; Ho, Kay T; Cantwell, Mark G; Burgess, Robert M; Pelletier, Marguerite C

2012-08-01

Triclosan is an antimicrobial compound that has been widely used in consumer products such as toothpaste, deodorant, and shampoo. Because of its widespread use, triclosan has been detected in various environmental media, including wastewater, sewage sludge, surface waters, and sediments. Triclosan is acutely toxic to numerous aquatic organisms, but very few studies have been performed on estuarine and marine benthic organisms. For whole sediment toxicity tests, the sediment-dwelling estuarine amphipod, Ampelisca abdita, and the epibenthic mysid shrimp, Americamysis bahia, are commonly used organisms. In the present study, median lethal concentration values (LC50) were obtained for both of these organisms using water-only and whole sediment exposures. Acute 96-h water-only toxicity tests resulted in LC50 values of 73.4 and 74.3 µg/L for the amphipod and mysid, respectively. For the 7-d whole sediment toxicity test, LC50 values were 303 and 257 mg/kg (dry wt) for the amphipod and mysid, respectively. Using equilibrium partitioning theory, these whole sediment values are equivalent to interstitial water LC50 values of 230 and 190 µg/L for the amphipod and mysid, respectively, which are within a threefold difference of the observed 96-h LC50 water-only values. Triclosan was found to accumulate in polychaete tissue in a 28-d bioaccumulation study with a biota-sediment accumulation factor of 0.23 kg organic carbon/kg lipid. These data provide some of the first toxicity data for triclosan with marine benthic and epibenthic species while also indicating a need to better understand the effects of other forms of sediment carbon, triclosan ionization, and organism metabolism of triclosan on the chemical's behavior and toxicity in the aquatic environment. Copyright © 2012 SETAC.

Feeding ecology of native and nonnative salmonids during the expansion of a nonnative apex predator in Yellowstone Lake, Yellowstone National Park

USGS Publications Warehouse

Syslo, John M.; Guy, Christopher S.; Koel, Todd M.

2016-01-01

The illegal introduction of Lake Trout Salvelinus namaycush into Yellowstone Lake, Yellowstone National Park, preceded the collapse of the native population of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri, producing a four-level trophic cascade. The Yellowstone Cutthroat Trout population’s collapse and the coinciding increase in Lake Trout abundance provided a rare opportunity to evaluate the feeding ecology of a native prey species and a nonnative piscivore species after the restructuring of a large lentic ecosystem. We assessed diets, stable isotope signatures, and depth-related CPUE patterns for Yellowstone Cutthroat Trout and Lake Trout during 2011–2013 to evaluate trophic overlap. To evaluate diet shifts related to density, we also compared 2011–2013 diets to those from studies conducted during previous periods with contrasting Yellowstone Cutthroat Trout and Lake Trout CPUEs. We illustrate the complex interactions between predator and prey in a simple assemblage and demonstrate how a nonnative apex predator can alter competitive interactions. The diets of Yellowstone Cutthroat Trout were dominated by zooplankton during a period when the Yellowstone Cutthroat Trout CPUE was high and were dominated by amphipods when the CPUE was reduced. Lake Trout shifted from a diet that was dominated by Yellowstone Cutthroat Trout during the early stages of the invasion to a diet that was dominated by amphipods after Lake Trout abundance had increased and after Yellowstone Cutthroat Trout prey had declined. The shifts in Yellowstone Cutthroat Trout and Lake Trout diets resulted in increased trophic similarity of these species through time due to their shared reliance on benthic amphipods. Yellowstone Cutthroat Trout not only face the threat posed by Lake Trout predation but also face the potential threat of competition with Lake Trout if amphipods are limiting. Our results demonstrate the importance of studying the long-term feeding ecology of fishes in

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.

Gray whale distribution relative to benthic invertebrate biomass and abundance: Northeastern Chukchi Sea 2009-2012

NASA Astrophysics Data System (ADS)

Brower, Amelia A.; Ferguson, Megan C.; Schonberg, Susan V.; Jewett, Stephen C.; Clarke, Janet T.

2017-10-01

The shallow continental shelf waters of the Bering and Chukchi seas are the northernmost foraging grounds of North Pacific gray whales (Eschrichtius robustus). Benthic amphipods are considered the primary prey of gray whales in these waters, although no comprehensive quantitative analysis has been performed to support this assumption. Gray whale relative abundance, distribution, and behavior in the northeastern Chukchi Sea (69°-72°N, 155-169°W) were documented during aerial surveys in June-October 2009-2012. Concurrently, vessel-based benthic infaunal sampling was conducted in the area in July-August 2009-10, September 2011, and August 2012. Gray whales were seen in the study area each month that surveys were conducted, with the majority of whales feeding. Statistical analyses confirm that the highest densities of feeding gray whales were associated with high benthic amphipod abundance, primarily within 70 km of shore from Point Barrow to Icy Cape, in water <50 m deep. Conversely, gray whales were not seen in 40-km×40-km cells containing benthic sampling stations with 85 m-2 or fewer amphipods. Continuing broad-scale aerial surveys in the Chukchi Sea and prey sampling near feeding gray whales will be an important means to monitor and document ongoing and predicted ecosystem changes.

Isotopic composition of carbon and nitrogen of suprabenthic fauna in the NW Balearic Islands (western Mediterranean)

NASA Astrophysics Data System (ADS)

Madurell, T.; Fanelli, E.; Cartes, J. E.

Stable isotope (δ 13C and δ 15N) analyses were performed on suprabenthic fauna collected in the western Mediterranean (NW Balearic Islands), at depths ranging between 350 and 780 m. Samples were collected seasonally at bi-monthly intervals during six cruises performed between August 2003 and June 2004, using a Macer-GIROQ suprabenthic sledge (0.5 mm mesh size). Twenty-four separate species (5 mysids, 12 amphipods, 2 cumaceans, 2 isopods, 1 euphausiid, 1 decapod and 1 fish) and bulk copepods were analyzed on a seasonal basis for stable carbon and nitrogen isotopes. Stable nitrogen isotope ratios (δ 15N) ranged from 2.3‰ (the amphipod Lepechinella manco in September 2003) to 13.0‰ (the amphipod Rhachotropis caeca in August 2003). δ 13C values ranged from - 24.2 (the cumacean Campylaspis sulcata in June 2004) to - 16.1 (the amphipod Bruzelia typica in November 2006). Both δ 13C and δ 15N values suggest that there are three trophic levels within the suprabenthic community. However, considering the bathymetric range of the species, the results suggest that the deepest assemblage supported only two trophic levels. The stable isotope ratios of suprabenthic fauna displayed a continuum of values and confirmed a wide spectrum of feeding types (from filter-feeders to predators). In general, and in spite of the poor knowledge about diets available for most suprabenthic species, higher δ 15N were found for carnivorous amphipods (e.g. Rhachotropis spp., Nicippe tumida) consuming copepods. Low overlap for δ 13C and δ 15N values was observed, though δ 15N values where less variable than δ 13C, which suggests high resource partitioning in this assemblage. Seasonal variations in isotopic composition for both δ 13C and δ 15N were low (less than 1‰ and 3‰, respectively) and variable depending on species. Low correlations between δ 13C and δ 15N of suprabenthic fauna were found for all periods studied, though increasing from February 2004 to June 2004 (after the

Fish, Benthic-Macroinvertebrate, and Stream-Habitat Data From Two Estuaries Near Galveston Bay, Texas, 2000-2001

DTIC Science & Technology

2002-01-01

0 0 0 1 0 2 0 0 0 2 5 Amphipoda Hyalellidae Hyalella azteca ( Saussure ) 0 0 16 0 0 0 0 0 0 0 16 Capitellida Capitellidae Mediomastus ambiseta (Hartman...0 0 0 0 0 0 0 0 14 0 14 Amphipoda Gammaridae Gammarus sp. 0 0 0 0 0 0 0 0 28 0 28 Amphipoda Hyalellidae Hyalella azteca ( Saussure ) 47 0 18 0 0 0 0 0

Direct and indirect effects of ocean acidification and warming on a marine plant-herbivore interaction.

PubMed

Poore, Alistair G B; Graba-Landry, Alexia; Favret, Margaux; Sheppard Brennand, Hannah; Byrne, Maria; Dworjanyn, Symon A

2013-11-01

The impacts of climatic change on organisms depend on the interaction of multiple stressors and how these may affect the interactions among species. Consumer-prey relationships may be altered by changes to the abundance of either species, or by changes to the per capita interaction strength among species. To examine the effects of multiple stressors on a species interaction, we test the direct, interactive effects of ocean warming and lowered pH on an abundant marine herbivore (the amphipod Peramphithoe parmerong), and whether this herbivore is affected indirectly by these stressors altering the palatability of its algal food (Sargassum linearifolium). Both increased temperature and lowered pH independently reduced amphipod survival and growth, with the impacts of temperature outweighing those associated with reduced pH. Amphipods were further affected indirectly by changes to the palatability of their food source. The temperature and pH conditions in which algae were grown interacted to affect algal palatability, with acidified conditions only affecting feeding rates when algae were also grown at elevated temperatures. Feeding rates were largely unaffected by the conditions faced by the herbivore while feeding. These results indicate that, in addition to the direct effects on herbivore abundance, climatic stressors will affect the strength of plant-herbivore interactions by changes to the susceptibility of plant tissues to herbivory.

Sediment nickel bioavailability and toxicity to estuarine crustaceans of contrasting bioturbative behaviors--an evaluation of the SEM-AVS paradigm.

PubMed

Chandler, G Thomas; Schlekat, Christian E; Garman, Emily R; He, Lijian; Washburn, Katherine M; Stewart, Emily R; Ferry, John L

2014-11-04

Robust sediment quality criteria require chemistry and toxicity data predictive of concentrations where population/community response should occur under known geochemical conditions. Understanding kinetic and geochemical effects on toxicant bioavailability is key, and these are influenced by infaunal sediment bioturbation. This study used fine-scale sediment and porewater measurement of contrasting infaunal effects on carbon-normalized SEM-AVS to evaluate safe or potentially toxic nickel concentrations in a high-binding Spartina saltmarsh sediment (4%TOC; 35-45 μmol-S2-·g(-1)). Two crustaceans producing sharply contrasting bioturbation--the copepod Amphiascus tenuiremis and amphipod Leptocheirus plumulosus--were cultured in oxic to anoxic sediments with SEM[Ni]-AVS, TOC, porewater [Ni], and porewater DOC measured weekly. From 180 to 750 μg-Ni·g(-1) sediment, amphipod bioturbation reduced [AVS] and enhanced porewater [Ni]. Significant amphipod uptake, mortality, and growth-depression occurred at the higher sediment [Ni] even when [SEM-AVS]/foc suggested acceptable risk. Less bioturbative copepods produced higher AVS and porewater DOC but exhibited net population growth despite porewater [Ni] 1.3-1.7× their aqueous [Ni] LOEC. Copepod aqueous tests with/without dissolved organic matter showed significant aqueous DOC protection, which suggests porewater DOC attenuates sediment Ni toxicity. The SEM[Ni]-AVS relationship was predictive of acceptable risk for copepods at the important population-growth level.

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.

Development and application of freshwater sediment-toxicity benchmarks for currently used pesticides

USGS Publications Warehouse

Nowell, Lisa H.; Norman, Julia E.; Ingersoll, Christopher G.; Moran, Patrick W.

2016-01-01

Sediment-toxicity benchmarks are needed to interpret the biological significance of currently used pesticides detected in whole sediments. Two types of freshwater sediment benchmarks for pesticides were developed using spiked-sediment bioassay (SSB) data from the literature. These benchmarks can be used to interpret sediment-toxicity data or to assess the potential toxicity of pesticides in whole sediment. The Likely Effect Benchmark (LEB) defines a pesticide concentration in whole sediment above which there is a high probability of adverse effects on benthic invertebrates, and the Threshold Effect Benchmark (TEB) defines a concentration below which adverse effects are unlikely. For compounds without available SSBs, benchmarks were estimated using equilibrium partitioning (EqP). When a sediment sample contains a pesticide mixture, benchmark quotients can be summed for all detected pesticides to produce an indicator of potential toxicity for that mixture. Benchmarks were developed for 48 pesticide compounds using SSB data and 81 compounds using the EqP approach. In an example application, data for pesticides measured in sediment from 197 streams across the United States were evaluated using these benchmarks, and compared to measured toxicity from whole-sediment toxicity tests conducted with the amphipod Hyalella azteca (28-d exposures) and the midge Chironomus dilutus (10-d exposures). Amphipod survival, weight, and biomass were significantly and inversely related to summed benchmark quotients, whereas midge survival, weight, and biomass showed no relationship to benchmarks. Samples with LEB exceedances were rare (n = 3), but all were toxic to amphipods (i.e., significantly different from control). Significant toxicity to amphipods was observed for 72% of samples exceeding one or more TEBs, compared to 18% of samples below all TEBs. Factors affecting toxicity below TEBs may include the presence of contaminants other than pesticides, physical

Tolerance of freshwater test organisms to formulated sediments for use as control materials in whole-sediment toxicity tests

USGS Publications Warehouse

Kemble, N.E.; Dwyer, F.J.; Ingersoll, C.G.; Dawson, T.D.; Norberg-King, T. J.

1999-01-01

A method is described for preparing formulated sediments for use intoxicity testing. Ingredients used to prepare formulated sediments included commercially available silt, clay, sand, humic acid, dolomite, and α-cellulose (as a source of organic carbon). α-Cellulose was selected as the source of organic carbon because it is commercially available, consistent from batch to batch, and low in contaminant concentrations. The tolerance of freshwater test organisms to formulated sediments for use as control materials in whole-sediment toxicity testing was evaluated. Sediment exposures were conducted for 10 d with the amphipod Hyalella azteca, the midges Chironomus riparius and C. tentans, and the oligochaete Lumbriculus variegatus and for 28 d with H. azteca. Responses of organisms in formulated sediments was compared with a field-collected control sediment that has routinely been used to determine test acceptability. Tolerance of organisms to formulated sediments was evaluated by determining responses to varying levels of α-cellulose, to varying levels of grain size, to evaluation of different food types, or to evaluation of different sources of overlying water. In the 10-d exposures, survival of organisms exposed to the formulated sediments routinely met or exceeded the responses of test organisms exposed to the control sediment and routinely met test acceptability criteria required in standard methods. Growth of amphipods and oligochaetes in 10-d exposures with formulated sediment was often less than growth of organisms in the field-collected control sediment. Additional research is needed, using the method employed to prepare formulated sediment, to determine if conditioning formulated sediments before starting 10-d tests would improve the growth of amphipods. In the 28-d exposures, survival of H. azteca was low when reconstituted water was used as the source of overlying water. However, when well water was used as the source of overlying water in 28-d exposures

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...

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...

77 FR 64272 - Endangered and Threatened Wildlife and Plants; Proposed Revision of Critical Habitat for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-19

.... (2008) found Peck's cave amphipod in gravel, rocks, and organic debris (leaves, roots, wood) immediately..., fertilizer nutrients, petroleum hydrocarbons, and semivolatile compounds such as industrial cleaning agents...; stormwater drainage pollutants including soaps, detergents, pharmaceuticals, heavy metals, fertilizer...

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...

Repair and Dredging of Bear Creek Marina Final Environmental Assessment

DTIC Science & Technology

2007-06-01

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

Long-term change in limnology and invertebrates in Alaskan boreal wetlands

USGS Publications Warehouse

Corcoran, R.M.; Lovvorn, J.R.; Heglund, P.J.

2009-01-01

Climate change is more pronounced at high northern latitudes, and may be affecting the physical, chemical, and biological attributes of the abundant wetlands in boreal forests. On the Yukon Flats, located in the boreal forest of northeast Alaska, wetlands originally sampled during 1985-1989 were re-sampled for water chemistry and macroinvertebrates in summer 2001-2003. Wetlands sampled lost on average 19% surface water area between these periods. Total nitrogen and most metal cations (Na, Mg, and Ca, but not K) increased between these periods, whereas total phosphorus and chlorophyll a (Chl a) declined. These changes were greater in wetlands that had experienced more drying (decreased surface area). Compared with 1985-1989, densities of cladocerans, copepods, and ostracods in both June and August were much higher in 2002-2003, whereas densities of amphipods, gastropods, and chironomid larvae were generally lower. In comparisons among wetlands in 2002-2003 only, amphipod biomass was lower in wetlands with lower Chl a, which might help explain the decline of amphipods since the late 1980s when Chl a was higher. The decline in Chl a corresponded to greatly increased zooplankton density in June, suggesting a shift in carbon flow from scrapers and deposit-feeders to water-column grazers. Declines in benthic and epibenthic deposit-feeding invertebrates suggest important food web effects of climate change in otherwise pristine wetlands of the boreal forest. ?? 2008 Springer Science+Business Media B.V.

Feeding preferences of mesograzers on aquacultured Gracilaria and sympatric algae

PubMed Central

Cruz-Rivera, Edwin; Friedlander, Michael

2011-01-01

While large grazers can often be excluded effectively from algal aquaculture operations, smaller herbivores such as small crustaceans and gastropods may be more difficult to control. The susceptibility of three Gracilaria species to herbivores was evaluated in multiple-choice experiments with the amphipod Ampithoe ramondi and the crab Acanthonyx lunulatus. Both mesograzers are common along the Mediterranean coast of Israel. When given a choice, the amphipod preferred to consume Gracilaria lemaneiformis significantly more than either G. conferta or G. cornea. The crab, however, consumed equivalent amounts of G. lemaneiformis and G. conferta, but did not consume G. cornea. Organic content of these algae, an important feeding cue for some mesograzers, could not account for these differences. We further assessed the susceptibility of a candidate species for aquaculture, G. lemaneiformis, against local algae, including common epiphytes. When given a choice of four algae, amphipods preferred the green alga Ulva lactuca over Jania rubens. However, consumption of U. lactuca was equivalent to those of G. lemaneiformis and Padina pavonica. In contrast, the crab showed a marked and significant preference for G. lemaneiformis above any of the other three algae offered. Our results suggest that G. cornea is more resistant to herbivory from common mesograzers and that, contrary to expectations, mixed cultures or epiphyte growth on G. lemaneiformis cannot reduce damage to this commercially appealing alga if small herbivores are capable of recruiting into culture ponds. Mixed cultures may be beneficial when culturing other Gracilaria species. PMID:22711945

An evaluation of the residual toxicity and chemistry of a sodium hydroxide-based ballast water treatment system for freshwater ships.

PubMed

Elskus, Adria A; Ingersoll, Christopher G; Kemble, Nile E; Echols, Kathy R; Brumbaugh, William G; Henquinet, Jeffrey W; Watten, Barnaby J

2015-06-01

Nonnative organisms in the ballast water of freshwater ships must be killed to prevent the spread of invasive species. The ideal ballast water treatment system (BWTS) would kill 100% of ballast water organisms with minimal residual toxicity to organisms in receiving waters. In the present study, the residual toxicity and chemistry of a BWTS was evaluated. Sodium hydroxide was added to elevate pH to >11.5 to kill ballast water organisms, then reduced to pH <9 by sparging with wet-scrubbed diesel exhaust (the source of CO2 ). Cladocerans (Ceriodaphnia dubia), amphipods (Hyalella azteca), and fathead minnows (Pimephales promelas) were exposed for 2 d to BWTS water under an air atmosphere (pH drifted to ≥9) or a 2.5% CO2 atmosphere (pH 7.5-8.2), then transferred to control water for 5 d to assess potential delayed toxicity. Chemical concentrations in the BWTS water met vessel discharge guidelines with the exception of concentrations of copper. There was little to no residual toxicity to cladocerans or fish, but the BWTS water was toxic to amphipods. Maintaining a neutral pH and diluting BWTS water by 50% eliminated toxicity to the amphipods. The toxicity of BWTS water would likely be minimal because of rapid dilution in the receiving water, with subsurface release likely preventing pH rise. This BWTS has the potential to become a viable method for treating ballast water released into freshwater systems. © 2015 SETAC.

Feeding habits of the speckled guitarfish Rhinobatos glaucostigma (Elasmobranchii: Rhinobatidae).

PubMed

Lara-Mendoza, R E; Márquez-Farías, J F; Román-Reyes, J C

2015-08-01

The stomachs of 464 speckled guitarfish Rhinobatos glaucostigma were sampled from the south-eastern Gulf of California (GC) to determine diet composition. Numerical indices and prey-specific index of relative importance ((%I)PSIR ) were used to determine the feeding strategy of the species. An analysis of similarity (ANOSIM) was used to determine differences in diet with respect to sex, season (dry or rainy) and maturity stages (immature or mature). The diversity and niche breadth (by sex, season and maturity) and a general trophic level were determined. The overall diet was dominated by shrimps ((%I)PSIR  = 43.47), amphipods ((%I)PSIR  = 18.89) and crabs ((%I)PSIR  = 18.07). ANOSIM demonstrated differences in the diet by maturity and season, but not by sex. Rainy and dry season diets were dominated by shrimps and amphipods, respectively. Immature specimens fed mainly on amphipods, whereas mature fish preferred shrimps and crabs. Rhinobatos glaucostigma showed a narrow niche breadth with an intermediary trophic level (TL  = 3.72) and can be considered as a secondary consumer in the soft-bottom demersal community of the south-east GC. Understanding the feeding habits and trophic level of R. glaucostigma is vital to help identify the segments of the population vulnerable to overfishing by artisanal and industrial fisheries, and to aid in conservation and management of this elasmobranch. © 2015 The Fisheries Society of the British Isles.

An evaluation of the residual toxicity and chemistry of a sodium hydroxide-based ballast water treatment system for freshwater ships

USGS Publications Warehouse

Elskus, Adria; Ingersoll, Christopher G.; Kemble, Nile E.; Echols, Kathy R.; Brumbaugh, William G.; Henquinet, Jeffrey; Watten, Barnaby J.

2015-01-01

Nonnative organisms in the ballast water of freshwater ships must be killed to prevent the spread of invasive species. The ideal ballast water treatment system (BWTS) would kill 100% of ballast water organisms with minimal residual toxicity to organisms in receiving waters. In the present study, the residual toxicity and chemistry of a BWTS was evaluated. Sodium hydroxide was added to elevate pH to >11.5 to kill ballast water organisms, then reduced to pH <9 by sparging with wet-scrubbed diesel exhaust (the source of CO2). Cladocerans (Ceriodaphnia dubia), amphipods (Hyalella azteca), and fathead minnows (Pimephales promelas) were exposed for 2 d to BWTS water under an air atmosphere (pH drifted to ≥9) or a 2.5% CO2 atmosphere (pH 7.5–8.2), then transferred to control water for 5 d to assess potential delayed toxicity. Chemical concentrations in the BWTS water met vessel discharge guidelines with the exception of concentrations of copper. There was little to no residual toxicity to cladocerans or fish, but the BWTS water was toxic to amphipods. Maintaining a neutral pH and diluting BWTS water by 50% eliminated toxicity to the amphipods. The toxicity of BWTS water would likely be minimal because of rapid dilution in the receiving water, with subsurface release likely preventing pH rise. This BWTS has the potential to become a viable method for treating ballast water released into freshwater systems.

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.

2015-12-22

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. 

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...

77 FR 49601 - Endangered and Threatened Wildlife and Plants; Endangered Status for Six West Texas Aquatic...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-16

... very system (four restricted range. springs). Phantom Lake springsnail.... San Solomon Spring very rare in a very system (four restricted range. springs). diminutive amphipod......... San Solomon Spring... Solomon Spring system to include four different existing spring outflows: San Solomon Spring, Giffin...

EXTRAPOLATING ACUTE MORTALITY OF AMPELISCA ABDITA TO POPULATION RISK USING A POPULATION MODEL AND MONITORING DATA

EPA Science Inventory

Ten-day acute mortality of the benthic amphipod, Ampelisca abdita, is used in a number of regulatory, research, and monitoring programs to evaluate chemical contamination of marine sediments. Although this endpoint has proven to be valuable for characterizing the relative toxicit...

Sea-Based X-Band (SBX) Radar Vessel Maintenance and Repair. Draft Environmental Assessment

DTIC Science & Technology

2011-02-14

crabs, lobsters, and shrimp), amphipods (small shrimp-like creatures), bivalves, barnacles, and gastropods (snails and slugs). Less common groups...A second phase will cover implementation of 10 years of post construction monitoring and adaptive management. Future 1 4.0 Cumulative Impacts

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...

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...

Assessment of gray whale feeding grounds and sea floor interaction in the northeastern Bering Sea

USGS Publications Warehouse

Nelson, C.H.; Johnson, K.R.; Barber, John H.

1983-01-01

A dense ampeliscid amphipod community in Chirikov Basin and around St. Lawrence Island in the northeastern Bering Sea has been outlined by summarizing biological studies, analyzing bioturbation in sediment samples, and examining sea floor photos and videotapes. The amphipod population is associated with a homogeneous, relict fine-grained sand body 0.10-1.5 m thick that is deposited during the marine transgression over the Bering land bridge 8,000-10,000 yr B.P. Modern current and water mass movements and perhaps whale feeding activity prevent modern deposition in this area. The distribution of the transgressive sand sheet, associated amphipod community and feeding gray whales mapped by aerial survey correlate closely with three types of sea-floor pits observed on high (500 kHz) and low (105 kHz) resolution side-scan sonar; they are attributed to gray whale feeding traces and their subsequent current scour modification. The fresh and modified feeding pits are present in 22,000 km2 of the basin and they cover a total of 2 to 18% of the sea floor in different areas of the feeding region. The smallest size class of pits approximates whale mouth gape size and is assumed to represent fresh whale feeding pits. Fresh feeding disturbance of the sea floor is estimated to average about 5.7% for a full feeding season. Combined with information that 34% of the measured benthic biomass is amphipod prey species, and calculating the number of gray whale feeding days in the Alaskan waters plus amount consumed per day, it can be estimated that Chirikov Basin, 2% of the feeding area, supplies a minimum of 5.3 to 7.1% of the gray whale's food resource in the Bering Sea and Arctic Ocean. If a maximum of 50% of the fresh feeding features are assumed to be missed because they parallel side-scan beam paths, then a maximum whale food resource of 14.2% is possible in northeastern Bering Sea. Because of side-scan techniques and possible higher amphipod biomass estimates, a reasonable minimum

Toxicity assessment of sediments from the Grand Calumet River and Indiana Harbor Canal in northwestern Indiana, USA

USGS Publications Warehouse

Ingersoll, C.G.; MacDonald, D.D.; Brumbaugh, W.G.; Johnson, B. Thomas; Kemble, N.E.; Kunz, J.L.; May, T.W.; Wang, N.; Smith, J.R.; Sparks, D.W.; Ireland, D.S.

2002-01-01

The objective of this study was to evaluate the toxicity of sediments from the Grand Calumet River and Indiana Harbor Canal located in northwestern Indiana, USA. Toxicity tests used in this assessment included 10-day sediment exposures with the amphipod Hyalella azteca, 31-day sediment exposures with the oligochaete Lumbriculus variegatus, and the Microtox® Solid-Phase Sediment Toxicity Test. A total of 30 sampling stations were selected in locations that had limited historic matching toxicity and chemistry data. Toxic effects on amphipod survival were observed in 60% of the samples from the assessment area. Results of a toxicity test with oligochaetes indicated that sediments from the assessment area were too toxic to be used in proposed bioaccumulation testing. Measurement of amphipod length after the 10-day exposures did not provide useful information beyond that provided by the survival endpoint. Seven of the 15 samples that were identified as toxic in the amphipod tests were not identified as toxic in the Microtox test, indicating that the 10-day H. azteca test was more sensitive than the Microtox test. Samples that were toxic tended to have the highest concentrations of metals, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). The toxic samples often had an excess of simultaneously extracted metals (SEM) relative to acid volatile sulfide (AVS) and had multiple exceedances of probable effect concentrations (PECs). Metals may have contributed to the toxicity of samples that had both an excess molar concentration of SEM relative to AVS and elevated concentrations of metals in pore water. However, of the samples that had an excess of SEM relative to AVS, only 38% of these samples had elevated concentration of metals in pore water. The lack of correspondence between SEM-AVS and pore water metals indicates that there are variables in addition to AVS controlling the concentrations of metals in pore water. A mean PEC quotient of 3

Trophodynamics of suprabenthic fauna on coastal muddy bottoms of the southern Tyrrhenian Sea (western Mediterranean)

NASA Astrophysics Data System (ADS)

Fanelli, E.; Cartes, J. E.; Badalamenti, F.; Rumolo, P.; Sprovieri, M.

2009-02-01

The trophodynamics of suprabenthic fauna were analyzed in the Gulf of Castellammare (North-western Sicily, Italy) at depths ranging between 40 and 80 m. Variations in species abundance and biomass together with changes in nitrogen and carbon stable isotope composition were explored at a seasonal scale, from November 2004 to June 2005. Suprabenthos showed maximum biomass and abundance from late winter to summer, while minimum values were found in autumn. The highest abundances of mysids and copepods occurred in March, 1 month after the peak of primary production. Amphipod abundance was higher in summer, likely due to a relative increase in organic matter in the sediments. Statistical analysis provided evidence for separation of sample abundances as a function of season. The best match between suprabenthos abundance and environmental variables was found with Chlorophyll a recorded 3 months before the sampling. Stable isotope analyses suggest a relatively complex food web in the Gulf of Castellammare with several potential food sources. Some suprabenthic species (i.e. mysids and copepods) exhibited depleted values of δ13C, indicating a planktonic source of nutrition. Cumaceans and amphipods displayed more enriched δ13C values, pointing to more detritivorous behaviour. A third group with intermediate δ13C values comprised species with a mixed diet (e.g. Ampelisca spp., Apherusa vexatrix and Harpinia spp.). Assuming a 15N-enrichment of ca. 2.54‰ between consumers and their diet, at least two trophic levels can be distinctly identified: (1) filter feeders/grazers (mysids, copepods), suspension/deposit feeders ( Ampelisca spp., A. vexatrix, small Goneplax rhomboides) and omnivores, alternatively feeding on detritus and small invertebrates such as meiobenthos (the cumacean Leucon mediterraneus or the amphipod Westwoodilla rectirostris); (2) carnivores on small crustaceans and zooplankton (the amphipod Harpinia spp., the gobiid fish Lesuerigobius suerii and the decapod

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...

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...

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...

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...

Influence of a Brazilian sewage outfall on the toxicity and contamination of adjacent sediments

USGS Publications Warehouse

Abessa, D.M.S.; Carr, R.S.; Rachid, B.R.F.; Sousa, E.C.P.M.; Hortelani, M.A.; Sarkis, J.E.

2005-01-01

The submarine sewage outfall of Santos (SSOS) is situated in the Santos Bay (São Paulo, Brazil) and is potentially a significant source of contaminants to the adjacent marine ecosystem. The present study aimed to assess the influence of SSOS on the sediment toxicity and contamination at Santos Bay. At the disposal site, sediments tended to be finer, organically richer and exhibited higher levels of surfactants and metals, sometimes exceeding the “Threshold Effect Level” values. The SSOS influence was more evident toward the East, where the sediments exhibited higher levels of TOC, total S and metals during the summer 2000 sampling campaign. Sediment toxicity to amphipods was consistently detected in four of the five stations studied. Amphipod survival tended to correlate negatively to Hg, total N and % mud. This work provides evidence that the SSOS discharge affects the quality of sediments from Santos Bay, and that control procedures are warranted.

Comparison of solid-phase and pore-water approaches for assessing the quality of marine and estuarine sediments

USGS Publications Warehouse

Carr, Robert Scott; Chapman, Duane C.

1992-01-01

As part of our continuing evaluation of the pore-water approach for assessing sediment quality, we made a series of side-by-side comparisons between the standard 10-day amphipod whole sediment test with the corophiid Grandidierella japonica and a suite of tests using pore water extracted from the same sediments. the pore-water tests evaluated were the sea urchin (Arbacia punctulata) sperm cell test and morphological development assay, the life-cycle test with the polychaete Dinophilus gyrociliatus, and acute exposures of red drum (Sciaenops ocellatus) embryo-larval stages. Sediment and surface microlayer samples were collected from contaminated sites. Whole-sediment, pore-water, and surface microlayer toxicity tests were performed. Pore-water toxicity tests were considerably more sensitive than the whole-sediment amphipod test, which is currently the most sensitive toxicity test now recommended for determining the acceptability of dredged material for open ocean disposal.

Food habits of fishes on an exposed sandy beach at Fukiagehama, South-West Kyushu Island, Japan

NASA Astrophysics Data System (ADS)

Nakane, Yukinori; Suda, Yusuke; Sano, Mitsuhiko

2011-06-01

To clarify the feeding habits and major food sources of sandy beach fishes, the gut contents of 55 fish species collected on a sandy beach at Fukiagehama, South-West Kyushu Island, Japan, were examined. Ontogenetic changes in food preference were recognized in nine species ( Hypoatherina valenciennei, Lateolabrax japonicus, Trachurus japonicus, Sillago japonica, Sphyraena japonica, Paralichthys olivaceus, Heteromycteris japonica, Paraplagusia japonica, and Takifugu niphobles). A cluster analysis based on dietary overlaps showed that the sandy beach fish assemblage comprised six trophic groups (mysid, amphipod, zooplankton, juvenile fish, terrestrial insect, and mollusk feeders). Of these, the first three groups were the most abundantly represented, whereas the last two were represented by only a single species. These results indicated that epibenthic macrofauna, such as mysids and gammaridean amphipods, and zooplankton, were important food resources for the fish assemblage at the study site, but infaunal macrobenthos, such as polychaetes and bivalves, being relatively unimportant.

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

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

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

Tidal river sediments in the Washington, D.C. area. 111 Biological effects associated with sediment contamination

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

Schlekat, C.E.; McGee, B.L.; Boward, D.M.

1994-06-01

Sediment toxicity and benthic marcroinvertebrate community structure were measured as one component of a study conceived to determine the distribution and effect of sediment contamination in tidal freshwater portions of the Potomac and Anacostia rivers in the Washington, D.C., area. Samples were collected at 15 sites. Analyses included a partial life cycle (28 d) whole sediment test using the amphipod Hyalella azteca (Talitridae) and an assessment of benthic community structure. Survival and growth (as estimated by amphipod length) were experimental endpoints for the toxicity test. Significant mortality was observed in 5 to 10 sites in the lower Anacostia River basinmore » and at the main channel Potomac River site. Sublethal toxicity, as measured by inhibition of amphipod growth, was not observed. Toxicity test results were in general agreement with synoptically measured sediment contaminant concentrations. Porewater total ammonia (NH{sub 3} + NH{sub 4}{sup +}) appears to be responsible for the toxicity of sediments from the Potomac River, while correlation analysis and simultaneously extracted metals: acid volatile sulfide (SEM:AVA) results suggest that the toxicity associated with Anacostia River sediments was due to organic compounds. Twenty-eight macroinvertebrate taxa were identified among all sites, with richness varying from 5 to 17 taxa per site. Groups of benthic assemblages identified by group-average cluster analysis exhibited variable agreement with sediment chemical and sediment toxicity results. Integration of toxicological, chemical, and ecological components suggests that adverse environmental effects manifest in lower Anacostia River benthos result from chemical contamination of sediment. 37 refs., 2 figs., 7 tabs.« less

Simulation of rapid ecological change in Lake Ontario

USGS Publications Warehouse

McKenna, James E.; Chalupnicki, Marc; Dittman, Dawn E.; Watkins, James M.

2017-01-01

Lower trophic level processes are integral to proper functioning of large aquatic ecosystems and have been disturbed in Lake Ontario by various stressors including exotic species. The invasion of benthic habitats by dreissenid mussels has led to systemic changes and native faunal declines. Size-dependent physiological rates, spatial differences and connectivity, competition, and differential population dynamics among invertebrate groups contributed to the change and system complexity. We developed a spatially explicit, individual-based mechanistic model of the benthic ecosystem in Lake Ontario, with coupling to the pelagic system, to examine ecosystem dynamics and effects of dreissenid mussel invasion and native fauna losses. Benthic organisms were represented by functional groups; filter-feeders (i.e., dreissenid mussels), surface deposit-feeders (e.g., native amphipod Diporeia spp.), and deposit-feeders (e.g., oligochaetes and other burrowers). The model was stable, represented ecological structure and function effectively, and reproduced observed effects of the mussel invasion. Two hypotheses for causes of Diporeia loss, competition or disease-like mortality, were tested. Simple competition for food did not explain observed declines in native surface deposit-feeders during the filter-feeder invasion. However, the elevated mortality scenario supports a disease-like cause for loss of the native amphipod, with population changes in various lake areas and altered benthic biomass transfers. Stabilization of mussel populations and possible recovery of the native, surface-deposit feeding amphipod were predicted. Although further research is required on forcing functions, model parameters, and natural conditions, the model provides a valuable tool to help managers understand the benthic system and plan for response to future disruptions.

Roles of epiphytes associated with macroalgae in benthic food web of a eutrophic coastal lagoon

NASA Astrophysics Data System (ADS)

Zheng, Xinqing; Huang, Lingfeng; Lin, Rongcheng; Du, Jianguo

2015-11-01

Macroalgae perform a significant function in the trophic dynamics in many coastal lagoons, and conventionally, they are the key trophic base that fuels the overall aquatic food web. However, few studies have considered the trophic contribution of epiphytes that attach to macroalgae in the diet of benthic primary consumers or their contribution to the trophic base of the aquatic food web. In this study, macrobenthic invertebrate biomass was combined with multiple-isotope-mixing models to distinguish the trophic importance of macroalgae and their associated epiphytic assemblages in the benthic food web during Ulva lactuca bloom in the Yundang Lagoon, a eutrophic coastal lagoon in Xiamen, China. Amphipods primarily dominated the zoobenthos, with the biomass varied from 40.9 g/m2 in January to 283.9 g/m2 in March. They mainly fed on U. lactuca and its associated epiphytes, which jointly contributed more than 60% to amphipod diets, but species-specific feeding habits were exhibited among amphipods. Using the zoobenthos biomass as a weighting factor, the contribution of U. lactuca and its epiphytes to total benthic communities during U. lactuca bloom exceeded 65%.The epiphytes were clearly utilized more than U. lactuca, with a median contribution ranging from 48.5% in January to 66.6% in March. Our findings demonstrate the trophic importance of the epiphytes in macroalgae-based coastal habitats, as found in many seagrass beds. Therefore, we propose that further food web studies of macroalgae-based ecosystems should pay greater attention to the role of epiphytes.

Multi-trophic resilience of boreal lake ecosystems to forest fires.

PubMed

Lewis, Tyler L; Lindberg, Mark S; Schmutz, Joel A; Bertram, Mark R

2014-05-01

Fires are the major natural disturbance in the boreal forest, and their frequency and intensity will likely increase as the climate warms. Terrestrial nutrients released by fires may be transported to boreal lakes, stimulating increased primary productivity, which may radiate through multiple trophic levels. Using a before-after-control-impact (BACI) design, with pre- and postfire data from burned and unburned areas, we examined effects of a natural fire across several trophic levels of boreal lakes, from nutrient and chlorophyll levels, to macroinvertebrates, to waterbirds. Concentrations of total nitrogen and phosphorus were not affected by the fire. Chlorophyll a levels were also unaffected, likely reflecting the stable nutrient concentrations. For aquatic invertebrates, we found that densities of three functional feeding groups did not respond to the fire (filterers, gatherers, scrapers), while two groups increased (shredders, predators). Amphipods accounted for 98% of shredder numbers, and we hypothesize that fire-mediated habitat changes may have favored their generalist feeding and habitat ecology. This increase in amphipods may, in turn, have driven increased predator densities, as amphipods were the most numerous invertebrate in our lakes and are commonly taken as prey. Finally, abundance of waterbird young, which feed primarily on aquatic invertebrates, was not affected by the fire. Overall, ecosystems of our study lakes were largely resilient to forest fires, likely due to their high initial nutrient concentrations and small catchment sizes. Moreover, this resilience spanned multiple trophic levels, a significant result for ecologically similar boreal regions, especially given the high potential for increased fires with future climate change.

Multi-trophic resilience of boreal lake ecosystems to forest fires

USGS Publications Warehouse

Lewis, Tyler L.; Lindberg, Mark S.; Schmutz, Joel A.; Bertram, M.R.

2014-01-01

Fires are the major natural disturbance in the boreal forest, and their frequency and intensity will likely increase as the climate warms. Terrestrial nutrients released by fires may be transported to boreal lakes, stimulating increased primary productivity, which may radiate through multiple trophic levels. Using a before-after-control-impact (BACI) design, with pre- and postfire data from burned and unburned areas, we examined effects of a natural fire across several trophic levels of boreal lakes, from nutrient and chlorophyll levels, to macroinvertebrates, to waterbirds. Concentrations of total nitrogen and phosphorus were not affected by the fire. Chlorophyll levels were also unaffected, likely reflecting the stable nutrient concentrations. For aquatic invertebrates, we found that densities of three functional feeding groups did not respond to the fire (filterers, gatherers, scrapers), while two groups increased (shredders, predators). Amphipods accounted for 98% of shredder numbers, and we hypothesize that fire-mediated habitat changes may have favored their generalist feeding and habitat ecology. This increase in amphipods may, in turn, have driven increased predator densities, as amphipods were the most numerous invertebrate in our lakes and are commonly taken as prey. Finally, abundance of waterbird young, which feed primarily on aquatic invertebrates, was not affected by the fire. Overall, ecosystems of our study lakes were largely resilient to forest fires, likely due to their high initial nutrient concentrations and small catchment sizes. Moreover, this resilience spanned multiple trophic levels, a significant result for ecologically similar boreal regions, especially given the high potential for increased fires with future climate change.

Geographic variation in feeding preference of a generalist herbivore: the importance of seaweed chemical defenses.

PubMed

McCarty, Amanda T; Sotka, Erik E

2013-08-01

The ecological impacts of generalist herbivores depend on feeding preferences, which can vary across and within herbivore species. Among mesoherbivores, geographic variation in host use can occur because host plants have a more restricted geographic distribution than does the herbivore, or there is local evolution in host preference, or both. We tested the role of local evolution using the marine amphipod Ampithoe longimana by rearing multiple amphipod populations from three regions (subtropical Florida, warm-temperate North Carolina and cold-temperate New England) and assaying their feeding preferences toward ten seaweeds that occur in some but not all regions. Six of the ten seaweeds produce anti-herbivore secondary metabolites, and we detected geographic variation in feeding preference toward five (Dictyota menstrualis, Dictyota ciliolata, Fucus distichus, Chondrus crispus and Padina gymnospora, but not Caulerpa sertularioides). Amphipod populations that co-occur with a chemically-rich seaweed tended to have stronger feeding preferences for that seaweed, relative to populations that do not co-occur with the seaweed. A direct test indicated that geographic variation in feeding preference toward one seaweed (D. ciliolata) is mediated by feeding tolerance for lipophilic secondary metabolites. Among the four seaweeds that produce no known secondary metabolites (Acanthophora, Ectocarpus, Gracilaria and Hincksia/Feldmannia spp.), we detected no geographic variation in feeding preference. Thus, populations are more likely to evolve greater feeding preferences for local hosts when those hosts produce secondary metabolites. Microevolution of feeding behaviors of generalist marine consumers likely depends on the availability and identity of local hosts and the strength of their chemical defenses.

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...

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...

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...

Inter-lab testing of Hyalella azteca water and sediment methods: 3 Results from 10- to 42-d tests conducted with the new water-only method

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...

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...

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 ...

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...

78 FR 40970 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Six West Texas...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-09

... first three species is limited to spring outflows in the San Solomon Springs system near Balmorhea in... Diminutive Amphipod Size of unit in Critical habitat unit Land ownership by type hectares (Acres) San Solomon..., assumptions, and analyses. We received comments from four knowledgeable individuals with scientific expertise...

78 FR 41227 - Endangered and Threatened Wildlife and Plants; Determination of Endangered Species Status for Six...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-09

... common in a very restricted range. system (four springs). Phantom Lake springsnail....... San Solomon Spring very rare in a very restricted range. system (four springs). diminutive amphipod San Solomon... Solomon Spring System. However, we use this term as a common reference for the four springs, which are...

76 FR 33035 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Roswell...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-07

... velocities over compact substrate (material on the bottom of the stream) ranging from deep organic silts to... Springsnail and Koster's Springsnail The springsnails feed on algae, bacteria, and decaying organic material... vegetation, and decaying organic matter (Holsinger 1976, p. 28; Pennak 1989, p. 476). Noel's amphipod is...

Spatial and temporal variation in invertebrate consumer diets in forested and herbaceous wetlands

Treesearch

Alani N. Taylor; Darold P. Batzer

2010-01-01

Macroinvertebrates have important functional roles in wetland ecosystems, but these roles are not always well understood. This study assessed which foods invertebrate consumers assimilate within a set of wetland habitats. During 2006 and 2007, non-Tanypodinae chironomid larvae and select crustaceans (Crangonyx amphipods, Caecidotea isopods, Simocephalus cladocerans)...

A sediment ecotoxicity assessment platform for in situ measures of chemistry, bioaccumulation and toxicity. Part 2: Integrated application to a shallow estuary.

PubMed

Rosen, Gunther; Chadwick, D Bart; Burton, G Allen; Taulbee, W Keith; Greenberg, Marc S; Lotufo, Guilherme R; Reible, Danny D

2012-03-01

A comprehensive, weight-of-evidence based ecological risk assessment approach integrating laboratory and in situ bioaccumulation and toxicity testing, passive sampler devices, hydrological characterization tools, continuous water quality sensing, and multi-phase chemical analyses was evaluated. The test site used to demonstrate the approach was a shallow estuarine wetland where groundwater seepage and elevated organic and inorganic contaminants were of potential concern. Although groundwater was discharging into the surficial sediments, little to no chemical contamination was associated with the infiltrating groundwater. Results from bulk chemistry analysis, toxicity testing, and bioaccumulation, however, suggested possible PAH toxicity at one station, which might have been enhanced by UV photoactivation, explaining the differences between in situ and laboratory amphipod survival. Concurrently deployed PAH bioaccumulation on solid-phase micro-extraction fibers positively correlated (r(2) ≥ 0.977) with in situ PAH bioaccumulation in amphipods, attesting to their utility as biomimetics, and contributing to the overall improved linkage between exposure and effects demonstrated by this approach. Published by Elsevier Ltd.

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...

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

... wetlands, water quality, tide, soil type) that are essential to the conservation of the species. Primary...), under the Endangered Species Act of 1973, as amended. In total, we are designating approximately 169... cave amphipod. Under the Endangered Species Act of 1973, as amended (Act), any species that is...

Potential Reservoirs and Risk Factors for VHSV IVb in an Enzootic System: Budd Lake, Michigan.

PubMed

Throckmorton, Elizabeth; Brenden, Travis; Peters, Amber K; Newcomb, Tammy J; Whelan, Gary E; Faisal, Mohamed

2017-03-01

Viral hemorrhagic septicemia virus genotype IVb (VHSV IVb) has caused major, sporadic fish die-offs in the Laurentian Great Lakes region of North America since 2005. Presently, factors affecting VHSV IVb persistence in enzootic systems are not well understood. Even with annual surveillance, the virus can go undetected for several years after an outbreak before again re-emerging, which suggests that the virus is maintained in the system either below detectable levels or in untested reservoirs. The aim of this study was to identify potential reservoirs of VHSV IVb in Budd Lake, Michigan; VHSV IVb was first detected in Budd Lake in 2007 but remained undetected until 2011. Additionally, we explored the susceptibility of naive fish introduced into a water body enzootic for VHSV IVb by stocking age-0 Largemouth Bass Micropterus salmoides at varying densities into enclosures in the lake. The virus was not detected among samples of the fishes Notropis spp. and Lepomis spp., cylindrical papershell mussels Anodontoides ferussacianus, leeches (subclass Hirudinea), sediment, or water. However, the virus was successfully isolated from amphipods (family Hyalellidae) and Largemouth Bass held in the enclosures. Our finding of VHSV IVb in Hyalellidae amphipods in combination with other research that has detected the virus in Diporeia spp., a large benthic amphipod important as a food resource to Great Lake fishes, suggests that benthic macroinvertebrates are a reservoir for VHSV IVb in infected systems. If there are environmental reservoirs for VHSV IVb in infected systems, they are likely unevenly distributed. Findings of this study add to our understanding of the seemingly complex ecology of this deadly and economically detrimental virus. Received February 22, 2016; accepted October 16, 2016.

Use of reconstituted waters to evaluate effects of elevated major ions associated with mountaintop coal mining on freshwater invertebrates

USGS Publications Warehouse

Kunz, James L.; Conley, Justin M.; Buchwalter, David B.; ,; Teresa, J.; Kemble, Nile E.; Wang, Ning; Ingersoll, Christopher G.

2013-01-01

In previous laboratory chronic 7-d toxicity tests conducted with the cladoceran Ceriodaphnia dubia, surface waters collected from Appalachian sites impacted by coal mining have shown toxic effects associated with elevated total dissolved solids (TDS). The objective of the present study was to evaluate the effects of elevated major ions in chronic laboratory tests with C. dubia (7-d exposure), a unionid mussel (Lampsilis siliquoidea; 28-d exposure), an amphipod (Hyalella azteca; 28-d exposure), and a mayfly (Centroptilum triangulifer; 35-d exposure) in 3 reconstituted waters designed to be representative of 3 Appalachian sites impacted by coal mining. Two of the reconstituted waters had ionic compositions representative of alkaline mine drainage associated with mountaintop removal and valley fill-impacted streams (Winding Shoals and Boardtree, with elevated Mg, Ca, K, SO4, HCO3), and a third reconstituted water had an ionic composition representative of neutralized mine drainage (Upper Dempsey, with elevated Na, K, SO4, and HCO3). The waters with similar conductivities but, with different ionic compositions had different effects on the test organisms. The Winding Shoals and Boardtree reconstituted waters were consistently toxic to the mussel, the amphipod, and the mayfly. In contrast, the Upper Dempsey reconstituted water was toxic to the mussel, the amphipod, and the cladoceran but was not toxic to the mayfly. These results indicate that, although elevated TDS can be correlated with toxicity, the specific major ion composition of the water is important. Moreover, the choice of test organism is critical, particularly if a test species is to be used as a surrogate for a range of faunal groups.

Soft-sediment crustacean diversity and distribution along the Portuguese continental shelf

NASA Astrophysics Data System (ADS)

Sampaio, Leandro; Mamede, Renato; Ricardo, Fernando; Magalhães, Luísa; Rocha, Hélder; Martins, Roberto; Dauvin, Jean-Claude; Rodrigues, Ana Maria; Quintino, Victor

2016-11-01

This study analyzed the crustacean diversity, distribution and relationship with environmental factors in the western and the southern Portuguese continental shelf, between 10 and 200 m depth. A total of 10,639 specimens belonging to 242 taxa from 90 families were identified, mostly amphipods (55.8% of the total taxa). The mysid Gastrosaccus spinifer and the amphipods Socarnes erythrophthalmus and Cheirocratus sundevallii were the most abundant and the amphipods Ampelisca brevicornis, Leucothoe incisa and Autonoe spiniventris were the most frequent species. The highest abundance and diversity was found in coarser sediments with up to 306 individuals per 0.1 m2. Alpha diversity ranged from 1 to 28 sp./0.1 m2. Moreover, this study confirmed six previously doubtful first records and added an additional 19 new records to the Portuguese fauna. The results also confirmed the Portuguese coast as a transition zone of mixed Atlantic and Mediterranean faunas and exposed a noticeable North African and Macaronesian influence. A multivariate analysis based on the abundance of crustaceans revealed six affinity groups characterized by: (a) C. sundevallii, Guernea (Guernea) coalita and Sarsinebalia cristoboi on very coarse sands; (b) G. spinifer, Nototropis falcatus and Pontocrates arenarius on coarse sands; (c) Othomaera othonis, Processa modica modica and Animoceradocus semiserratus on heterogeneous medium sands; (d) A. brevicornis, Urothoe pulchella and Necalianassa truncata on fine sands; (e) Ampelisca pectenata, Bodotria scorpioides and Astacilla dilatata on heterogeneous fine sands and (f) Callianassa subterranea, Ampelisca tenuicornis and Ampelisca typica on muddy fine sands. Sediment grain-size and depth were the variables best related to the benthic crustacean spatial distribution patterns along the Portuguese continental shelf.

Toxicity of sediments from lead-zinc mining areas to juvenile freshwater mussels (Lampsilis siliquoidea) compared to standard test organisms

USGS Publications Warehouse

Besser, John M.; Ingersoll, Christopher G.; Brumbaugh, William G.; Kemble, Nile E.; May, Thomas W.; Wang, Ning; MacDonald, Donald D.; Roberts, Andrew D.

2015-01-01

Sediment toxicity tests compared chronic effects on survival, growth, and biomass of juvenile freshwater mussels (28-d exposures with Lampsilis siliquoidea) to the responses of standard test organisms—amphipods (28-d exposures with Hyalella azteca) and midges (10-d exposures with Chironomus dilutus)—in sediments from 2 lead–zinc mining areas: the Tri-State Mining District and Southeast Missouri Mining District. Mussel tests were conducted in sediments sieved to <0.25 mm to facilitate recovery of juvenile mussels (2–4 mo old). Sediments were contaminated primarily with lead, zinc, and cadmium, with greater zinc and cadmium concentrations in Tri-State sediments and greater lead concentrations in southeast Missouri sediments. The frequency of highly toxic responses (reduced 10% or more relative to reference sites) in Tri-State sediments was greatest for amphipod survival (25% of samples), midge biomass (20%), and mussel survival (14%). In southeast Missouri sediments, the frequency of highly toxic samples was greatest for mussel biomass (25%) and amphipod biomass (13%). Thresholds for metal toxicity to mussels, expressed as hazard quotients based on probable effect concentrations, were lower for southeast Missouri sediments than for Tri-State sediments. Southeast Missouri sites with toxic sediments had 2 or fewer live mussel taxa in a concurrent mussel population survey, compared with 7 to 26 taxa at reference sites. These results demonstrate that sediment toxicity tests with juvenile mussels can be conducted reliably by modifying existing standard methods; that the sensitivity of mussels to metals can be similar to or greater than standard test organisms; and that responses of mussels in laboratory toxicity tests are consistent with effects on wild mussel populations.

A new species of Hyalella from the Andes in Perú (Crustacea: Amphipoda: Hyalellidae).

PubMed

González, Exequiel R; Watling, Les

2002-06-01

Hyalella pauperocavae n. sp. from Huancayo, Perú, is described. Five other epigean freshwater amphipods have been described from Peru (excluding Lake Titicaca), but the lack of type material and poor descriptions do not allow the assignment of the species described here to any of the names known for the area.

75 FR 8889 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-26

... ecotoxicity studies have been conducted on hydrogen sulfide, mainly on freshwater invertebrates and fish... values for freshwater invertebrates ranged from 0.021 mg/L (amphipod) to 1.07 mg/L (isopod), and 48- to 96- hour LC 50 values for estuarine/marine invertebrates ranged from 0.063 mg/L (saltwater shrimp) to...

Chronic toxicity of nickel-spiked freshwater sediments: variation in toxicity among eight invertebrate taxa and eight sediments

USGS Publications Warehouse

Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.; Ivey, Chris D.; Kunz, James L.; Kemble, Nile E.; Schlekat, Christian E.; Garman, Emily R.

2013-01-01

This study evaluated the chronic toxicity of Ni-spiked freshwater sediments to benthic invertebrates. A 2-step spiking procedure (spiking and sediment dilution) and a 2-stage equilibration period (10 wk anaerobic and 1 wk aerobic) were used to spike 8 freshwater sediments with wide ranges of acid-volatile sulfide (AVS; 0.94–38 µmol/g) and total organic carbon (TOC; 0.42–10%). Chronic sediment toxicity tests were conducted with 8 invertebrates (Hyalella azteca, Gammarus pseudolimnaeus, Chironomus riparius, Chironomus dilutus, Hexagenia sp., Lumbriculus variegatus, Tubifex tubifex, and Lampsilis siliquoidea) in 2 spiked sediments. Nickel toxicity thresholds estimated from species-sensitivity distributions were 97 µg/g and 752 µg/g (total recoverable Ni; dry wt basis) for sediments with low and high concentrations of AVS and TOC, respectively. Sensitive species were tested with 6 additional sediments. The 20% effect concentrations (EC20s) for Hyalella and Gammarus, but not Hexagenia, were consistent with US Environmental Protection Agency benchmarks based on Ni in porewater and in simultaneously extracted metals (SEM) normalized to AVS and TOC. For Hexagenia, sediment EC20s increased at less than an equimolar basis with increased AVS, and toxicity occurred in several sediments with Ni concentrations in SEM less than AVS. The authors hypothesize that circulation of oxygenated water by Hexagenia led to oxidation of AVS in burrows, creating microenvironments with high Ni exposure. Despite these unexpected results, a strong relationship between Hexagenia EC20s and AVS could provide a basis for conservative site-specific sediment quality guidelines for Ni.

Chronic toxicity of nickel-spiked freshwater sediments: variation in toxicity among eight invertebrate taxa and eight sediments.

PubMed

Besser, John M; Brumbaugh, William G; Ingersoll, Christopher G; Ivey, Chris D; Kunz, James L; Kemble, Nile E; Schlekat, Christian E; Garman, Emily Rogevich

2013-11-01

This study evaluated the chronic toxicity of Ni-spiked freshwater sediments to benthic invertebrates. A 2-step spiking procedure (spiking and sediment dilution) and a 2-stage equilibration period (10 wk anaerobic and 1 wk aerobic) were used to spike 8 freshwater sediments with wide ranges of acid-volatile sulfide (AVS; 0.94-38 µmol/g) and total organic carbon (TOC; 0.42-10%). Chronic sediment toxicity tests were conducted with 8 invertebrates (Hyalella azteca, Gammarus pseudolimnaeus, Chironomus riparius, Chironomus dilutus, Hexagenia sp., Lumbriculus variegatus, Tubifex tubifex, and Lampsilis siliquoidea) in 2 spiked sediments. Nickel toxicity thresholds estimated from species-sensitivity distributions were 97 µg/g and 752 µg/g (total recoverable Ni; dry wt basis) for sediments with low and high concentrations of AVS and TOC, respectively. Sensitive species were tested with 6 additional sediments. The 20% effect concentrations (EC20s) for Hyalella and Gammarus, but not Hexagenia, were consistent with US Environmental Protection Agency benchmarks based on Ni in porewater and in simultaneously extracted metals (SEM) normalized to AVS and TOC. For Hexagenia, sediment EC20s increased at less than an equimolar basis with increased AVS, and toxicity occurred in several sediments with Ni concentrations in SEM less than AVS. The authors hypothesize that circulation of oxygenated water by Hexagenia led to oxidation of AVS in burrows, creating microenvironments with high Ni exposure. Despite these unexpected results, a strong relationship between Hexagenia EC20s and AVS could provide a basis for conservative site-specific sediment quality guidelines for Ni. © 2013 SETAC.

Heavy metal accumulation in lizards living near a phosphate treatment plant: possible transfer of contaminants from aquatic to terrestrial food webs.

PubMed

Nasri, Intissar; Hammouda, Abdessalam; Hamza, Foued; Zrig, Ahlem; Selmi, Slaheddine

2017-05-01

We investigated the accumulation of heavy metals in Bosk's fringe-toed lizards (Acanthodactylus boskianus) living in Gabès region (southeastern Tunisia), in relation to habitat, diet, and distance from the Gabès-Ghannouche factory complex of phosphate treatment. More specifically, we compared the concentrations of cadmium, lead, and zinc in the stomach contents and samples of the liver, kidney, and tail from lizards living in four sites corresponding to different combinations of habitat (coastal dunes vs backshore) and distance from the factory complex (<500 vs 20 km). Examination of stomach contents showed that lizards living on the coastal dunes mainly feed on littoral amphipods, while those living in the backshore feed exclusively on terrestrial invertebrates. The concentrations of heavy metals in lizard tissues were overall positively correlated with those in the preys they ingested. Moreover, there was a general tendency towards increased concentrations of cadmium, lead, and zinc in the samples from lizards living on coastal dunes compared to those from the other sites, although some differences still lacked statistical significance. These results suggest that the highest contamination of lizards living on coastal dunes was probably related to the ingestion of contaminated amphipods. Thus, amphipods and Bosk's fringe-toed lizards seem to provide an important link between the marine and terrestrial food webs, with higher concentrations appearing to accumulate from materials released into the sea rather than the terrestrial environment. With regard to metal distribution among tissues, our results were overall in agreement with previous findings in other reptiles. In particular, cadmium was most concentrated in the liver samples, stressing once more the role of the liver as a storage organ of Cd. Moreover, high concentrations of the three assessed metals were found in the kidney samples, showing the role of the kidney as an active site of heavy metal

Toxicological and chemical assessment of ordnance compounds in marine sediments and porewaters

USGS Publications Warehouse

Nipper, M.; Carr, R.S.; Biedenbach, J.M.; Hooten, R.L.; Miller, K.

2002-01-01

Toxicological and chemical studies were performed with a silty and a sandy marine sediment spiked with 2,6-dinitrotoluene (2,6-DNT), 2,4,6-trinitrophenylmethylnitramine (tetryl), or 2,4,6-trinitrophenol (picric acid). Whole sediment toxicity was analyzed by the 10-day survival test with the amphipod Ampelisca abdita, and porewater toxicity tests assessed macro-algae (Ulva fasciata) zoospore germination and germling growth, sea urchin (Arbacia punctulata) embryological development, and polychaete (Dinophilus gyrociliatus) survival and reproduction. Whole sediments spiked with 2,6-DNT were not toxic to amphipods. The fine-grained sediment spiked with tetryl was also not acutely toxic. The tetryl and picric acid LC50 values in the sandy sediment were 3.24 and 144 mg/kg dry weight, respectively. The fine-grained sediment spiked with picric acid generated a U-shaped concentration-response curve in the amphipod test, with increased survival both in the lowest and highest concentration. Grain-size distribution and organic carbon content strongly influenced the behavior of ordnance compounds in spiked sediments. Very low concentrations were measured in some of the treatments and irreversible binding and biodegradation are suggested as the processes responsible for the low measurements. Porewater toxicity varied with its sedimentary origin and with ordnance compound. The sea urchin embryological development test tended to be the least sensitive. Tetryl was the most toxic chemical in all porewater tests, and picric acid the least toxic. Samples spiked with 2,6-DNT contained a degradation product identified as 2-methyl-3-nitroaniline (also known as 2-amino-6-nitrotoluene), and unidentified peaks, possibly degradation products, were also seen in some of the picric acid- and tetryl-spiked samples. Degradation products may have played a role in observed toxicity. ?? 2002 Elsevier Science Ltd. All rights reserved.

Uptake pathway for Ag bioaccumulation in three benthic invertebrates exposed to contaminated sediments

USGS Publications Warehouse

Yoo, H.; Lee, J.-S.; Lee, B.-G.; Lee, I.T.; Schlekat, C.E.; Koh, C.-H.; Luoma, S.N.

2004-01-01

We exposed 3 benthic invertebrates, the clam Macoma balthica, the polychaete Neanthes arenaceodentata and the amphipod Leptocheirus plumulosus, to Ag-contaminated sediments to evaluate the relative importance of various uptake routes (sediments, porewater or overlying water, and supplementary food) for Ag bioaccumulation. Silver bioaccumulation was evaluated at 4 levels of sediment Ag (0.1, 0,3, 1,2 and 3.3 ??mol Ag g-1) and 2 levels of acid-volatile sulfide (AVS), <0.5 or ???40 ??mol g-1, and compared among food treatments with or without Ag contamination, or with different food rations. L. plumulosus were incubated for 35 d in the Ag-contaminated sediments after 3 mo of Ag-sediment equilibration, and M. balthica and N. arenaceodentata for 19 d after 5 mo equilibration. Ag bioaccumulation in the 3 organisms was significantly correlated with 1N HCl-extractable Ag concentrations (Ag-SEM: simultaneously extracted Ag with AVS) in sediments. The Ag concentrations in porewater and overlying water were greatest in the sediments with least AVS, consistent with previous studies. Nevertheless, the amphipod and clam exposed to oxic sediments (<0.5 ??mol AVS g-1) accumulated amounts of Ag similar to those accumulated by organisms exposed to anoxic sediments (???40 ??mol AVS g-1), when Ag-SEM levels were comparable. The dissolved Ag source was important for bioaccumulation in the polychaete N. arenaceodentata. Amphipods fed Ag-contaminated food contained ???1.8-fold more tissue Ag concentrations than those fed uncontaminated food. As suggested in kinetic (DYMBAM) modeling studies, ingestion of contaminated sediments and food were the principle routes of Ag bioaccumulation by the benthic invertebrates during chronic exposure, but the relative importance of each uptake route differed among species.

Environmental fate of pyrethroids in urban and suburban stream sediments and the appropriateness of Hyalella azteca model in determining ecological risk.

PubMed

Palmquist, Katherine; Fairbrother, Anne; Salatas, Johanna; Guiney, Patrick D

2011-07-01

According to several recent studies using standard acute Hyalella azteca sediment bioassays, increased pyrethroid use in urban and suburban regions in California has resulted in the accumulation of toxic concentrations of pyrethroids in sediments of area streams and estuaries. However, a critical review of the literature indicates that this is likely an overestimation of environmental risk. Hyalella azteca is consistently the most susceptible organism to both aqueous and sediment-associated pyrethroid exposures when compared to a suite of other aquatic taxa. In some cases, H. azteca LC50 values are less than the community HC10 values, suggesting that the amphipod is an overly conservative model for community- or ecosystem-level impacts of sediment-associated pyrethroids. Further, as a model for responses of field populations of H. azteca, the laboratory bioassays considerably overestimate exposure, because the amphipod is more appropriately characterized as an epibenthic organism, not a true sediment dweller; H. azteca preferentially inhabit aquatic macrophytes, periphyton mats, and leaf litter, which drastically reduces their exposure to contaminated sediments. Sediment-bound pyrethroids are transported via downstream washing of fine particulates resulting in longer range transport but also more efficient sequestration of the chemical. In addition, site-specific variables such as sediment organic carbon content, grain size, temperature, and microbial activity alter pyrethroid bioavailability, degradation, and toxicity on a microhabitat scale. The type and source of the carbon in particular, influences the pyrethroid sequestering ability of sediments. The resulting irregular distribution of pyrethroids in stream sediments suggests that sufficient nonimpacted habitat may exist as refugia for resident sediment-dwelling organisms for rapid recolonization to occur. Given these factors, we argue that the amphipod model provides, at best, a screening level assessment of

Aerial Surveys of Bowhead Whales, North Slope, Alaska.

DTIC Science & Technology

1980-02-01

euphausiids. amphipods. copepods, mysids, and pteropods (Lowrey and Burns). While basically "skimmers," they do forage very near the bottom, at least in...1 3o- t 3-7. IDawhin . Wit1. 1960. lire seasonal migrat ion of* huLmpback whles. pp. 14 5- 17(). In: K.S Norris ted.). W hales. dolphirns, aird

Sampling, Testing, and Test Interpretation of Dredged Material Proposed for Unconfined, Open-Water Disposal in Central Puget Sound. Volume 5. Evaluation Procedures Technical Appendix. Phase 1

DTIC Science & Technology

1988-06-01

petroleum and combustion products. Consequently, the PSDDA list of chemicals of concern includes 16 polynuclear aromatic hydrocarbons (PAHs). Measurement...This material usually includes slurry water. Hydrocarbon . An organic compound composed of carbon and hydrogen. Petroleum and its derived compounds... Hydrocarbons Phthalates Pesticides Miscellaneous Compounds Biological Testing --Amphipod Bioassay Microtox Bioassay Macoma Bioaccumulation Costs for

Mantacaprella macaronensis, a new genus and species of Caprellidae (Crustacea: Amphipoda) from Canary Islands and Cape Verde.

PubMed

Maite, Vázquez-Luis; José M, Guerra-García; Susana, Carvalho; Lydia Png-Gonzalez

2013-01-01

Mantacaprella macaronensis new genus, new species, is described based on specimens collected from Canary Islands and Cape Verde. Mantacaprella is close to the genera Parambus, Pseudolirius, Propodalirius and Paracaprella, but can be distinguished by the combination of the following characteristics: pereopods 3, 4 and 5 two-articulate; pereopods 6 and 7 six-articulate; mandibular molar present and palp absent; male abdomen with a pair of well-developed appendages. The new species has been found living in Cymodocea nodosa meadows and Caulerpa prolifera beds from 8.8 to 14.6 m depth in Gran Canaria (Canary Islands), and in natural rocky and artificial habitats (shipwrecks) at 25 m in Sal Island (Cape Verde). Even though the new species is one of the dominant amphipods inhabiting meadows of Cymodocea nodosa in Gran Canaria and in Cape Verde, it had not been described so far. This reflects the lack of knowledge on Macaronesian invertebrates, such as amphipods, and the need of further taxonomical studies to better characterise the whole biodiversity of this region and to design adequate programmes of management and conservation.

Multifrequency acoustic observations of zooplankton in Knight Inlet, B.C

NASA Astrophysics Data System (ADS)

Trevorrow, Mark V.; Mackas, David L.; Benfield, Mark C.

2004-05-01

A collaborative investigation of midwater zooplankton aggregations in a coastal fjord was conducted in November 2002. Midwater aggregations of zooplankton in a coastal fjord were sampled and mapped using a calibrated, three-frequency (38, 120, and 200 kHz) vessel-based echo-sounder system, a multinet towed zooplankton net (BIONESS), and a high-resolution in situ camera system (ZOOVIS). Dense daytime layers of euphausiids and amphipods near 70- to 90-m depth were found in the lower reaches of the inlet, especially concentrated by tidal flows around a sill which rises above the layer. Quantitative euphausiid and amphipod backscattering measurements, combined with in situ species, size, and abundance estimates, were found to agree closely with recent size- and orientation-averaged fluid-cylinder scattering models produced by Stanton et al. Also, in situ scattering measurements of physonect siphonophores were found to have a much stronger low-frequency (38 kHz) scattering strength, in agreement with a simple bubble scattering model. [Work supported by Dr. J. Eckman, ONR code 322BC.

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.

Management of Bottom Sediments Containing Toxic Substances: Proceedings of the U.S./Japan Experts Meeting (11th) Held in Seattle, Washington, on 4-6 November 1985.

DTIC Science & Technology

1987-04-01

biological effects (benthic community structure, bioaccumulation , fish histopathology) indi- cators were used along with historical data to iden...chlorinated pesticides, plasticizers (pthalates), and poly- nuclear aromatic hydrocarbons (PAH)]. Over 425 point and nonpoint discharges have been identified...collected sediments (i.e., amphipod blo- assays as a lethal indicator and oyster larvae bioassays as a sublethal Indi- cator), bioaccumulation of

Effects of experimental otter trawling on benthic assemblages on Western Bank, northwest Atlantic Ocean

NASA Astrophysics Data System (ADS)

Kenchington, Ellen L. R.; Gilkinson, Kent D.; MacIsaac, Kevin G.; Bourbonnais-Boyce, Cynthia; Kenchington, Trevor J.; Smith, Stephen J.; Gordon, Donald C., Jr.

2006-10-01

The effects of otter trawling on a hard-bottom ecosystem on Western Bank on Canada's Scotian Shelf were examined experimentally from 1997 to 1999 with an asymmetrical BACI design. The site was located within an area that had been closed to fishing since 1987 to protect juvenile haddock. An experimental line was trawled 12-14 times on three separate occasions over a 20 month period. The benthic macrofauna and megafauna were sampled before and after trawling on both impact and control lines with both a grab and a photographic system. The 100 grab samples collected contained 341 taxa, primarily polychaetes, amphipods and molluscs, the majority (60%) of which were epifaunal. Biomass was dominated by the horse-mussel Modiolus modiolus, a long-lived bivalve, while the tube-building amphipod Ericthonius fasciatus was the most abundant species. Through the study period the benthos on the control lines showed little qualitative or quantitative change in individual taxa or community metrics. However, the abundance of 24 individual taxa (polychaetes, amphipods, echinoderms and molluscs) changed significantly, with the majority of these increasing. This resulted in a significantly different relative abundance of taxa between years as detected through ANOSIM. A significant change in relative biomass amongst the taxa was also observed. Trawling had few detectable immediate effects on the abundance or biomass of individual taxa and none on community composition. A few taxa, primarily a mixture of polychaetes and amphipods, decreased significantly after trawling and data from fish stomachs collected during the experiment (Kenchington, E.L., Gordon Jr., D.C., Bourbonnais-Boyce, C., MacIsaac, K.G., Gilkinson, K.D., McKeown, D.L., Vass, W.P., 2005. Effects of experimental otter trawling on the feeding of demersal fish on Western Bank, Nova Scotia. Amer. Fish. Soc. Symp. 41, 391-409) showed that some of these were scavenged by demersal fish. Fifteen taxa showed significant decreases

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

DTIC Science & Technology

2010-10-01

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

Continued Analysis of High-Frequency Broadband Acoustic Scattering from Non-Linear Internal Waves during SW06

DTIC Science & Technology

2010-09-30

1) to understanding and quantifying the contribution to acoustic backscattering from the seasonal pycnocline, 2) to investigate the statistics...echoes from relatively small zooplankton, such as pteropods or copepods, potentially in the presence of microstructure or in mixed zooplankton assemblages...Lavery et al., 2007) have shown that the predicted scattering from zooplankton is dominated by copepods, amphipods, and pteropods , depending on the

Final Environmental Assessment for Test Area D-84 Waterside Redevelopment

DTIC Science & Technology

2012-09-01

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

[Proboscis worm, Echinorhynchus gadi (Zoega) from a relict cod of Lake Mogil'noye].

PubMed

Kulachkova, V G; Timofeeva, T A

1977-01-01

Data on the extensiveness and intensity of infection of Kildin island cod with Echinorhynchus gadi in various seasons are given. E. gadi was proved to have a one-year life cycle and Gammarus duebeni as an intermediate host in the lake. A change of the parasite generations occurs in late summer--autumn. A high extensiveness (100%) and intensity of Kildin cod infection with E. gadi depends on the feeding habits (monophagy) and narrow distribution range of the host. Infection intensity is directly correlated with the fish age. Selfregulation of the parasite quantity in the host's intenstine is an important factor affecting the existence of E. gadi population in Lake Mogilnoye.

A novel marine silk.

PubMed

Kronenberger, Katrin; Dicko, Cedric; Vollrath, Fritz

2012-01-01

The discovery of a novel silk production system in a marine amphipod provides insights into the wider potential of natural silks. The tube-building corophioid amphipod Crassicorophium bonellii produces from its legs fibrous, adhesive underwater threads that combine barnacle cement biology with aspects of spider silk thread extrusion spinning. We characterised the filamentous silk as a mixture of mucopolysaccharides and protein deriving from glands representing two distinct types. The carbohydrate and protein silk secretion is dominated by complex β-sheet structures and a high content of charged amino acid residues. The filamentous secretion product exits the gland through a pore near the tip of the secretory leg after having moved through a duct, which subdivides into several small ductules all terminating in a spindle-shaped chamber. This chamber communicates with the exterior and may be considered the silk reservoir and processing/mixing space, in which the silk is mechanically and potentially chemically altered and becomes fibrous. We assert that further study of this probably independently evolved, marine arthropod silk processing and secretion system can provide not only important insights into the more complex arachnid and insect silks but also into crustacean adhesion cements.

Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (North Atlantic)

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

Buckley, J.

1989-08-01

Species profiles are literature summaries of the taxonomy, life history, and environmental requirements of coastal fishes and aquatic invertebrates. They are designed to assist with environmental impact assessments. The rainbow smelt is an abundant forage fish for commercially and recreationally valuable fishes such as striped bass and bluefish on the East Coast and several species of salmon and trout in the Great Lakes. The rainbow smelt also supports an important sportfishery throughout most of its range. In 1976, the total smelt harvest in the coastal waters of New England was 105,000 lb. Coastal rainbow smelt are anadromous, spawning in freshwatermore » and maturing in saline water. Spawning peaks in spring. Salinities above 12 ppt were fatal to eggs. Reported fecundities are 7,000 to 44,000 eggs per female. Smelt are always found in shallow water (<6 m deep) and within 2 km of the shore. Larval and juvenile smelt along the coast feed on planktonic crustaceans. Larger juveniles and adults feed on euphausiids, amphipods, on planktonic crustaceans. Larger juveniles and adults feed on euphausiids, amphipods, polychaetes, and fish. Smelt move locally to search for optimum water temperatures. 46 refs., 2 figs., 1 tab.« less

Diet dynamics of the adult piscivorous fish community in Spirit Lake, Iowa, USA 1995-1997

USGS Publications Warehouse

Liao, H.; Pierce, C.L.; Larscheid, J.G.

2002-01-01

Diets of adults of six important piscivorous fish species, black crappie Pomoxis nigromaculatus, largemouth bass Micropterus salmoides, northern pike Esox lucius, smallmouth bass Micropterus dolomieui, walleye Stizostedion vitreum, and yellow perch Perca flavescens were quantified in Spirit Lake, Iowa, USA from May to October in 1995-1997. Forty-one prey taxa were found in the diets of these species, including 19 species of fish. The most important prey taxa overall were yellow perch, amphipods and dipterans. Diets of northern pike and walleye were dominated by yellow perch. Largemouth bass diets included large percentages of both yellow perch and black bullhead Ameiurus melas. Smallmouth bass diets included large percentages of both yellow perch and crayfish. Black crappie and yellow perch diets were dominated by invertebrates, primarily amphipods and dipterans. There were pronounced differences in diets among species, among size classes within species and over time. Most of the dominant prey taxa we documented in the diets of piscivorous species were in accordance with previous studies, but a few deviated significantly from expectations. Many of the temporal diet changes were asynchronous among piscivorous species and size classes, suggesting different responses to common prey resources over time.

Do priority effects outweigh environmental filtering in a guild of dominant freshwater macroinvertebrates?

PubMed

Little, Chelsea J; Altermatt, Florian

2018-04-11

Abiotic conditions have long been considered essential in structuring freshwater macroinvertebrate communities. Ecological drift, dispersal and biotic interactions also structure communities, and although these mechanisms are more difficult to detect, they may be of equal importance in natural communities. Here, we hypothesized that in 10 naturally replicated headwater streams in eastern Switzerland, locally dominant amphipod species would be associated with differences in environmental conditions. We conducted repeated surveys of amphipods and used a hierarchical joint species distribution model to assess the influence of different drivers on species co-occurrences. The species had unique environmental requirements, but a distinct spatial structure in their distributions was unrelated to habitat. Species co-occurred much less frequently than predicted by the model, which was surprising because laboratory and field evidence suggests they are capable of coexisting in equal densities. We suggest that niche preemption may limit their distribution and that a blocking effect related to the specific linear configuration of streams determines which species colonizes and dominates a given stream catchment, thus suggesting a new solution a long-standing conundrum in freshwater ecology. © 2018 The Author(s).

Morphology-diet relationships in four killifishes (Teleostei, Cyprinodontidae, Orestias) from Lake Titicaca.

PubMed

Maldonado, E; Hubert, N; Sagnes, P; De Mérona, B

2009-02-01

This study explores the relationship between morphology and diet in four Andean killifishes (Orestias) from Lake Titicaca that are known to differ in habitat use. Species that fed preferentially on amphipods (Orestias albus) or molluscs (Orestias luteus) separated in multivariate space from other species that feed on cladocera and algae (Orestias agassii and Orestias jussiei). Generally, specimens feeding on cladocera were characterized by a short, blunt nose with a small mouth; whereas, specimens feeding on amphipods exhibited a long snout with a large mouth. Specimens including molluscs in their diet tended to have a larger posterior part of the head and the larger opercles than others; while the occurrence of substratum in gut content was generally related to a short but deep head. The present analysis suggests that the littoral O. jussiei has an intermediate phenotype and diet between the pelagic (O. agassii) and benthic (O. albus and O. luteus) species. Results suggest that resource partitioning was occurring and that several morphological traits relate to characteristics of the diet, and it is inferred that the benthic, the pelagic and the littoral zones in the lake host different prey communities constituting distinct adaptive landscapes.

Biological Processes Affecting Bioaccumulation, Transfer, and Toxicity of Metal Contaminants in Estuarine Sediments

DTIC Science & Technology

2011-12-01

ER-1503 December 2011 Celia Y. Chen Dartmouth College Nicholas S. Fisher Stonybrook University Joseph R. Shaw Indiana University...and Cd because of their importance in DoD sites and other industrial point sources. Hg comes from the combustion of fossil fuels, cadmium from...investigate the trophic transfer of cadmium , inorganic mercury and methylmercury from phytoplankton to a benthic amphipod to fish, simulating a

Ecological Effects of Rubble Weir Jetty Construction at Murrells Inlet, South Carolina. Volume 2. Changes in Macrobenthic Communities of Sandy Beach and Nearshore ENvironments.

DTIC Science & Technology

1984-06-01

species were not commonly observed, and oligochaetes and nematodes were abundant in the area. Rany of these differences were attributed to normal...1977-78 (Table 3). Subtidally, amphipods and pelecypods were most abundant in 1982, while oligochaetes and nematodes largely dominated the intertidal...generally restricted to that level and the highest intertidal level (Table 10). Nematodes were also abundant in the upper intertidal zone, with greatest

An algal carbon budget for pelagic-benthic coupling in Lake Michigan

USGS Publications Warehouse

Fitzgerald, S.A.; Gardner, W.S.

1993-01-01

Assimilation and respiration rates of Diporeia sp., an abundant benthic amphipod, and of sediment microheterotrophs were measured in a microcosm study. Release of radioisotope in the form of dissolved organic compounds was much lower than that incorporated and respired for both Diporeia and sediment bacteria. Of the 61 mmol C m-2 of algal C estimated to be deposited during the spring bloom. -from Authors

Rapid Sediment Characterization Tools

DTIC Science & Technology

2008-09-01

sensitive to organic and inorganic toxicants as mysid shrimp, silverside fish, chain diatoms, and sea urchins . The data from the bioassay can be...correlated with more conventional toxicity tests, such as amphipod and sea urchin development [17], [23]. The QwikLite Testing System™ can be used for...7 Barajas and Associates with Tetra Tech, op. cit. 8 Battelle, SEA Engineering and Neptune and Company. 2005

Continued Analysis of High-Frequency Broadband Acoustic Scattering from Non-Linear Internal Waves during SW06

DTIC Science & Technology

2014-06-20

zooplankton models (Lavery et al, 2007) have shown that the predicted scattering from zooplankton is dominated by copepods, amphipods, and pteropods ...which there is significant salinity gradient, the predicted scattering from the seasonal pycnocline during SW06 was not able to account for the...has focused on echoes from relatively small zooplankton, such as pteropods or copepods, potentially in the presence of microstructure or in mixed

Evaluation of Dredged Material Proposed for Ocean Disposal. Testing Manual

DTIC Science & Technology

1991-02-01

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

Assessing the Extent of Sediment Contamination Around Creosote-treated Pilings Through Chemical and Biological Analyses

NASA Astrophysics Data System (ADS)

Stefansson, E. S.

2008-12-01

Creosote is a common wood preservative used to treat marine structures, such as docks and bulkheads. Treated dock pilings continually leach polycyclic aromatic hydrocarbons (PAHs) and other creosote compounds into the surrounding water and sediment. Over time, these compounds can accumulate in marine sediments, reaching much greater concentrations than those in seawater. The purpose of this study was to assess the extent of creosote contamination in sediments, at a series of distances from treated pilings. Three pilings were randomly selected from a railroad trestle in Fidalgo Bay, WA and sediment samples were collected at four distances from each: 0 meters, 0.5 meters, 1 meter, and 2 meters. Samples were used to conduct two bioassays: an amphipod bioassay (Rhepoxynius abronius) and a sand dollar embryo bioassay. Grain size and PAH content (using a fluorometric method) were also measured. Five samples in the amphipod bioassay showed significantly lower effective survival than the reference sediment. These consisted of samples closest to the piling at 0 and 0.5 meters. One 0 m sample in the sand dollar embryo bioassay also showed a significantly lower percentage of normal embryos than the reference sediment. Overall, results strongly suggest that creosote-contaminated sediments, particularly those closest to treated pilings, can negatively affect both amphipods and echinoderm embryos. Although chemical data were somewhat ambiguous, 0 m samples had the highest levels of PAHs, which corresponded to the lowest average survival in both bioassays. Relatively high levels of PAHs were found as far as 2 meters away from pilings. Therefore, we cannot say how far chemical contamination can spread from creosote-treated pilings, and at what distance this contamination can still affect marine organisms. These results, as well as future research, are essential to the success of proposed piling removal projects. In addition to creosote-treated pilings, contaminated sediments must

Distribution, abundance, biomass and diversity of benthic infauna in the Northeast Chukchi Sea, Alaska: Relation to environmental variables and marine mammals

NASA Astrophysics Data System (ADS)

Schonberg, Susan V.; Clarke, Janet T.; Dunton, Kenneth H.

2014-04-01

In summer 2009 and 2010, as part of Chukchi Sea Offshore Monitoring in Drilling Area - Chemical and Benthos (COMIDA CAB) program, we performed a quantitative assessment of the biomass, abundance, and community structure of benthic infaunal populations of the Northeastern Chukchi Sea. This analysis documented a benthic species inventory of 361 taxa collected from 142 individual van Veen grab samples (0.1 m-2) at 52 stations. Infaunal abundance was dominated by Polychaeta, Mollusca, and Crustacea. Large concentrations of bivalves (up to 1235 m-2; 920.2 gww m-2) were collected south of Hanna Shoal where flow from two water masses converge and deposit labile carbon to the seafloor, as indicated by low surface sediment C:N ratios. Amphipods (up to 1640 m-2; 26.0 gww m-2), and polychaetes (up to 4665 m-2; 114.7 gww m-2) were documented from multiple stations west of and within Barrow Canyon. This high productivity was most likely due to the "canyon effect", where marine and coastal detrital carbon supplies are channeled by the canyon structure, enhancing carbon deposition and flux, which supports rich benthic communities within the canyon and surrounding areas. To examine the relationships between infaunal distributions of all collected taxa with the physical environment, we used a Biota and Environment matching (BIO-ENV) routine. A combination of water depth, bottom-water temperature and salinity, surface sediment total organic nitrogen (TON) and sediment C:N molar ratios correlated closest with infaunal abundance distribution (ρ=0.54), indicating that multiple factors influence the success of benthic communities. BIO-ENV routines produced similar correlation results when performed on targeted walrus prey items (bivalves (ρ=0.50), polychaetes (ρ=0.53), but gray whale prey items (amphipods) were not strongly correlated to any combination of physical environmental factors (ρ=0.24). Distributions of primary prey items for gray whales (amphipods) and walruses (bivalves

Native and Non-Native Plants Provide Similar Refuge to Invertebrate Prey, but Less than Artificial Plants

PubMed Central

Grutters, Bart M. C.; Pollux, Bart J. A.; Verberk, Wilco C. E. P.; Bakker, Elisabeth S.

2015-01-01

Non-native species introductions are widespread and can affect ecosystem functioning by altering the structure of food webs. Invading plants often modify habitat structure, which may affect the suitability of vegetation as refuge and could thus impact predator-prey dynamics. Yet little is known about how the replacement of native by non-native vegetation affects predator-prey dynamics. We hypothesize that plant refuge provisioning depends on (1) the plant’s native status, (2) plant structural complexity and morphology, (3) predator identity, and (4) prey identity, as well as that (5) structurally similar living and artificial plants provide similar refuge. We used aquatic communities as a model system and compared the refuge provided by plants to macroinvertebrates (Daphnia pulex, Gammarus pulex and damselfly larvae) in three short-term laboratory predation experiments. Plant refuge provisioning differed between plant species, but was generally similar for native (Myriophyllum spicatum, Ceratophyllum demersum, Potamogeton perfoliatus) and non-native plants (Vallisneria spiralis, Myriophyllum heterophyllum, Cabomba caroliniana). However, plant refuge provisioning to macroinvertebrate prey depended primarily on predator (mirror carp: Cyprinus carpio carpio and dragonfly larvae: Anax imperator) and prey identity, while the effects of plant structural complexity were only minor. Contrary to living plants, artificial plant analogues did improve prey survival, particularly with increasing structural complexity and shoot density. As such, plant rigidity, which was high for artificial plants and one of the living plant species evaluated in this study (Ceratophyllum demersum), may interact with structural complexity to play a key role in refuge provisioning to specific prey (Gammarus pulex). Our results demonstrate that replacement of native by structurally similar non-native vegetation is unlikely to greatly affect predator-prey dynamics. We propose that modification of

A Pilot Study of the Effects of Post-Hurricane Katrina Floodwater Pumping on the Chemistry and Toxicity of Violet Marsh Sediments

DTIC Science & Technology

2006-10-01

to be suitable for testing without manipulations. Survival of amphipods in the control sediment from Sequim Bay , WA was above the 90-percent level...Treatment Mean Percent Survival Coefficient of Variation (%) Negative Control ( Sequim Bay , WA) 90 ± 4 3.9 Reference (Lake Pontchartrain, LA) 95...assessed along with a perform- ance control sediment ( Sequim , WA, USA Lat. 48.0587 Long. -123.0235 and a reference sedi- ment (Lake Pontchartrain

Case Study Application of the Biodiversity Security Index to Ranking Feasibility Studies for Ecosystem Restoration Projects of the U.S. Army Corps of Engineers

DTIC Science & Technology

2016-04-01

determinations are more common for certain invertebrates , such as gastropods (snails), but the taxonomy is improving rapidly. The RSI approach to resource...arrow for invertebrate animals. Check the box for Mollusca. Then check to make sure your status and location criteria remain the same, search for the...mollusk list and store. Go back to invertebrate animals and select the down arrow for “Crustacea”. Then select crayfish, isopods, amphipods, and

Transmission of Microsporidian Parasites of Mosquitoes.

DTIC Science & Technology

1983-06-01

aquatic animals in a 19. spore suspension, including ostracods, amphipods, spiders, beetle larvae, and phantom midges, 2) Feeding spores to crayfish...dragonfly larvae, damselfly larvae, water scorpions, beetles , Anopheles larvae, snails, and sosquitofish. In experiment 1, no germination was seen. In... rhinoceros from Tonga. J. Gen. Virol. 47, 431-438. Ohtaki, T. and C.M. Williams. 1970. Inactivation of -- ecdysone and cyas- terone by larvae of the flesh fly

Is there a role for antioxidant carotenoids in limiting self-harming immune response in invertebrates?

PubMed

Cornet, Stéphane; Biard, Clotilde; Moret, Yannick

2007-06-22

Innate immunity relies on effectors, which produce cytotoxic molecules that have not only the advantage of killing pathogens but also the disadvantage of harming host tissues and organs. Although the role of dietary antioxidants in invertebrate immunity is still unknown, it has been shown in vertebrates that carotenoids scavenge cytotoxic radicals generated during the immune response. Carotenoids may consequently decrease the self-harming cost of immunity. A positive relationship between the levels of innate immune defence and circulating carotenoid might therefore be expected. Consistent with this hypothesis, we show that the maintenance and use of the prophenoloxidase system strongly correlate with carotenoid concentration in haemolymph within and among natural populations of the crustacean Gammarus pulex.

Is reduced benthic flux related to the Diporeia decline? Analysis of spring blooms and whiting events in Lake Ontario

USGS Publications Warehouse

Watkins, James M.; Rudstam, Lars G.; Crabtree, Darran L.; Walsh, Maureen

2013-01-01

Benthic monitoring by USGS off the southern shore of Lake Ontario from October 1993 to October 1995 provides a detailed view of the early stages of the decline of the native amphipod Diporeia. A loss of the 1994 and 1995 year classes of Diporeia preceded the disappearance of the native amphipod at sites near Oswego and Rochester at depths from 55 to 130 m. In succeeding years, Diporeia populations continued to decline in Lake Ontario and were nearly extirpated by 2008. Explanations for Diporeia 's decline in the Great Lakes include several hypotheses often linked to the introduction and expansion of exotic zebra and quagga mussels (Dreissena sp.). We compare the timeline of the Diporeia decline in Lake Ontario with trends in two sources of organic matter to the sediments — spring diatom blooms and late summer whiting events. The 1994–95 decline of Diporeia coincided with localized dreissenid effects on phytoplankton in the nearshore and a year (April 1994 to May 1995) of decreased flux of organic carbon recorded by sediment traps moored offshore of Oswego. Later declines of profundal (> 90 m) Diporeia populations in 2003 were poorly associated with trends in spring algal blooms and late summer whiting events. Lake Ontario/Diporeia/Dreissena/remote sensing.

Diffusive gradients in thin films technique provide robust prediction of metal bioavailability and toxicity in estuarine sediments.

PubMed

Amato, Elvio D; Simpson, Stuart L; Jarolimek, Chad V; Jolley, Dianne F

2014-04-15

Many sediment quality assessment frameworks incorporate contaminant bioavailability as a critical factor regulating toxicity in aquatic ecosystems. However, current approaches do not always adequately predict metal bioavailability to organisms living in the oxidized sediment surface layers. The deployment of the diffusive gradients in thin films (DGT) probes in sediments allows labile metals present in pore waters and weakly bound to the particulate phase to be assessed in a time-integrated manner in situ. In this study, relationships between DGT-labile metal fluxes within 5 mm of the sediment-water interface and lethal and sublethal effects to the amphipod Melita plumulosa were assessed in a range of contaminated estuarine sediments during 10-day laboratory-based bioassays. To account for differing toxicities of metals, DGT fluxes were normalized to water (WQG) or sediment quality guidelines or toxicity thresholds specific for the amphipod. The better dose-response relationship appeared to be the one based on WQG-normalized DGT fluxes, which successfully predicted toxicity despite the wide range of metals and large variations in sediment properties. The study indicated that the labile fraction of metals measured by DGT is useful for predicting metal toxicity to benthic invertebrates, supporting the applicability of this technique as a rapid monitoring tool for sediments quality assessments.

Sediment quality assessment studies of Tampa bay, Florida

USGS Publications Warehouse

Carr, Scott R.; Chapman, Duane C.; Long, Edward R.; Windom, Herbert L.; Thursby, Glen; Sloane, Gail M.; Wolfe, Douglas A.

1996-01-01

A survey of the toxicity of sediments throughout the Tampa Bay estuary was performed as part of the National Oceanic and Atmospheric Administration's National Status and Trends Program. The objectives of the survey were to determine the spatial extent and severity of toxicity and to identify relationships between chemical contamination and toxicity. Three independent toxicity tests were performed: a 10-d amphipod survival test of the whole sediments with Ampelisca abdita, a sea urchin fertilization test of sediment pore water with Arbacia punctulata, and a 5-min Microtox® bioluminescence test with solvent extracts of the sediments. Seventy-three percent of the 165 undiluted sediment pore-water samples were significantly toxic relative to reference samples with the sea urchin fertilization test. In contrast, only 2% of the 165 samples were significantly toxic in the amphipod tests. The causes of toxicity were not determined. However, concentrations of numerous trace metals, pesticides, polychlorinated biphenyl (PCB) congeners, polycyclic aromatic hydrocarbons (PAHs), and ammonia were highly correlated with pore-water toxicity. Concentrations of many substances, especially total dichlorodiphenyltrichloroethanes (DDTs), endrin, total PCBs, certain PAHs, lead, and zinc, occurred at concentrations in the toxic samples that equaled or exceeded concentrations that have been previously associated with sediment toxicity.

[Re-description of Syncyamus aequus, Lincoln and Hurley, 1981 (Amphipoda: Cyamidae), and ectoparasite of Stenella coeruleoalba (Meyen, 1883) and first discovery in Italian waters].

PubMed

Mariniello, L; Cerioni, S; Di Cave, D

1994-12-01

Syncyamus aequus Lincoln & Hurley, 1981, an amphipod parasite reported for the first time in South African waters, is re-examined in order to clarify the taxonomic value of some morphological characters not described in detail in the original description and in the following records (Raga, 1988; Sedlak-Weinstein, 1991). Three females (two ovigerous) and six males were collected from two specimens of Stenella coeruleoalba (Meyen, 1833) stranded along the Central Thyrrenian coasts in 1988 and 1993. The amphipods fixed and stored in 70 degrees ethanol were cleared with lactophenol for examination. Drawings were made with the aid of a Leitz microscope drawing attachment. The specimens examined showed the presence of spines located on pereopods I and II, which were lacking in the original description of S. aequus. The authors had the opportunity to compare the specimens (male, female and ovigerous female) with the paratype (PEMK2g) deposited in the Natural History Museum of London. The present re-examination reveals a morphological homogeneity among the specimens collected in Italian waters, the paratype and the individuals recorded by Raga (1988), thus suggesting that they belong to the same species, having a broad geographical distribution. This is the first record of S. aequus in Italian waters.

Comparison of multifrequency acoustic and in situ measurements of zooplankton abundances in Knight Inlet, British Columbia.

PubMed

Trevorrow, Mark V; Mackas, David L; Benfield, Mark C

2005-06-01

An investigation of midwater zooplankton aggregations in a coastal fjord was conducted in November 2002. This study focused on quantitative comparisons between a calibrated, three-frequency (38, 120, and 200 kHz) vessel-based echo-sounder, a multinet towed zooplankton sampler (BIONESS), and a high-resolution underwater camera (ZOOVIS). Daytime layers of euphausiids and amphipods near 70-90-m depth were observed in lower parts of the inlet, especially concentrated by tidal flows around a sill. Quantitative backscatter measurements of euphausiids and amphipods, combined with in situ size and abundance estimates, and using an assumed tilt-angle distribution, were in agreement with averaged fluid-cylinder scattering models produced by Stanton and Chu [ICES J. Mar. Sci. 57, 793-807, (2000)]. Acoustic measurements of physonect siphonophores in the upper inlet were found to have a strong 38-kHz scattering strength, in agreement with a damped bubble scattering model using a diameter of 0.4 mm. In relatively dense euphausiid layers, ZOOVIS abundance estimates were found to be a factor of 2 to 4 higher than the acoustic estimates, potentially due to deviations from assumed euphausiid orientation. Nocturnal near-surface euphausiid scattering exhibited a strong (15 dB) and rapid (seconds) sensitivity to vessel lights, interpreted as due to changing animal orientation.

Comparison of multifrequency acoustic and in situ measurements of zooplankton abundances in Knight Inlet, British Columbia

NASA Astrophysics Data System (ADS)

Trevorrow, Mark V.; Mackas, David L.; Benfield, Mark C.

2005-06-01

An investigation of midwater zooplankton aggregations in a coastal fjord was conducted in November 2002. This study focused on quantitative comparisons between a calibrated, three-frequency (38, 120, and 200 kHz) vessel-based echo-sounder, a multinet towed zooplankton sampler (BIONESS), and a high-resolution underwater camera (ZOOVIS). Daytime layers of euphausiids and amphipods near 70-90-m depth were observed in lower parts of the inlet, especially concentrated by tidal flows around a sill. Quantitative backscatter measurements of euphausiids and amphipods, combined with in situ size and abundance estimates, and using an assumed tilt-angle distribution, were in agreement with averaged fluid-cylinder scattering models produced by Stanton and Chu [ICES J. Mar. Sci. 57, 793-807, (2000)]. Acoustic measurements of physonect siphonophores in the upper inlet were found to have a strong 38-kHz scattering strength, in agreement with a damped bubble scattering model using a diameter of 0.4 mm. In relatively dense euphausiid layers, ZOOVIS abundance estimates were found to be a factor of 2 to 4 higher than the acoustic estimates, potentially due to deviations from assumed euphausiid orientation. Nocturnal near-surface euphausiid scattering exhibited a strong (15 dB) and rapid (seconds) sensitivity to vessel lights, interpreted as due to changing animal orientation. .

Macrobenthos in anthropogenically influenced zones of a coralline marine protected area in the Gulf of Kachchh, India

NASA Astrophysics Data System (ADS)

Sukumaran, Soniya; Vijapure, Tejal; Mulik, Jyoti; Rokade, M. A.; Gajbhiye, S. N.

2013-02-01

The Gulf of Kachchh Marine National Park and Sanctuary (MNPS) has one of the four coral reef systems of India. However, owing to its unique geographical position, this area has been transformed into an industrial hub dominated by oil and gas production, refining and transportation facilities. This study investigates the status of macrobenthos along with associated hydro-sedimentological data at 30 stations, sampled within three industrially active zones of the MNPS. The bottom water and sediment characteristics recorded in the study area fulfil the prescribed criteria for ecosensitive zones of India, despite the various stressors operational in the region. The univariate parameters suggest a healthy macrobenthic community except for a few pockets of stressed environment. However, CCA and correlation analyses indicate that even at low levels, petroleum hydrocarbons, along with sediment texture, were influencing polychaete community structure. As this protected area is denoted a "high oil spill risk area", polychaete/amphipod ratio was employed to verify the environmental status which revealed that a major part of the study area had a good representation of oil-sensitive amphipods. The current study is the first of its kind to provide valuable baseline data of macrobenthos along with prevailing environmental conditions in this ecosensitive area.

Latitude, temperature, and habitat complexity predict predation pressure in eelgrass beds across the Northern Hemisphere.

PubMed

Reynolds, Pamela L; Stachowicz, John J; Hovel, Kevin; Boström, Christoffer; Boyer, Katharyn; Cusson, Mathieu; Eklöf, Johan S; Engel, Friederike G; Engelen, Aschwin H; Eriksson, Britas Klemens; Fodrie, F Joel; Griffin, John N; Hereu, Clara M; Hori, Masakazu; Hanley, Torrance C; Ivanov, Mikhail; Jorgensen, Pablo; Kruschel, Claudia; Lee, Kun-Seop; McGlathery, Karen; Moksnes, Per-Olav; Nakaoka, Masahiro; O'Connor, Mary I; O'Connor, Nessa E; Orth, Robert J; Rossi, Francesca; Ruesink, Jennifer; Sotka, Erik E; Thormar, Jonas; Tomas, Fiona; Unsworth, Richard K F; Whalen, Matthew A; Duffy, J Emmett

2018-01-01

Latitudinal gradients in species interactions are widely cited as potential causes or consequences of global patterns of biodiversity. However, mechanistic studies documenting changes in interactions across broad geographic ranges are limited. We surveyed predation intensity on common prey (live amphipods and gastropods) in communities of eelgrass (Zostera marina) at 48 sites across its Northern Hemisphere range, encompassing over 37° of latitude and four continental coastlines. Predation on amphipods declined with latitude on all coasts but declined more strongly along western ocean margins where temperature gradients are steeper. Whereas in situ water temperature at the time of the experiments was uncorrelated with predation, mean annual temperature strongly positively predicted predation, suggesting a more complex mechanism than simply increased metabolic activity at the time of predation. This large-scale biogeographic pattern was modified by local habitat characteristics; predation declined with higher shoot density both among and within sites. Predation rates on gastropods, by contrast, were uniformly low and varied little among sites. The high replication and geographic extent of our study not only provides additional evidence to support biogeographic variation in predation intensity, but also insight into the mechanisms that relate temperature and biogeographic gradients in species interactions. © 2017 by the Ecological Society of America.

Evaluation of Metal Toxicity in Streams Affected by Abandoned Mine Lands, Upper Animas River Watershed, Colorado

USGS Publications Warehouse

Besser, John M.; Allert, Ann L.; Hardesty, Douglas K.; Ingersoll, Christopher G.; May, Thomas W.; Wang, Ning; Leib, Kenneth J.

2001-01-01

water; (3) to develop site-specific thresholds for toxicity of Zn and Cu in stream water; and (4) to develop models of the contributions of Cu and Zn to toxicity of stream water, which may be used to characterize toxicity before and after planned remediation efforts. We evaluated the toxicity of metal-contaminated sediments by conducting sediment toxicity tests with two species of benthic invertebrates, the midge, Chironomus tentans. and the amphipod, Hyalella azteca. Laboratory toxicity tests with both taxa, exposed to fine stream-bed sediments collected in September 1997, showed some evidence of sediment toxicity, as survival of midge larvae in sediments from Cement Creek (C48) and lower Mineral Creek (M34), and growth of amphipods in sediments from these sites and three Animas River sites (A68, Animas at Silverton; A72, Animas below Silverton, and A73, Animas at Elk Park) were significantly reduced compared to a reference site, South Mineral Creek (SMC) . Amphipods were also exposed to site water and fine stream-bed sediment, separately and in combination, during the late summer low flow period (August-September) of 1998. In these studies, stream water, with no sediment present, from all five sites tested (same sites as above, except C48) caused 90% to 100% mortality of amphipods. In contrast, significant reductions in survival of amphipods occurred at two sites (A72 and SMC) in exposures with field-collected sediment plus stream water, and at only one site (A72) in exposures with sediments and clean overlying water. Concentrations of Zn, Pb, Cu, and Cd were high in both sediment and pore water (interstitial water) from most sites tested, but greatest sediment toxicity was apparently associated with greater concentrations of Fe and/or Al in sediments. These results suggest that fine stream-bed sediments of the more contaminated stream reaches of the upper Animas River watershed are toxic to benthic invertebrates, but that these impacts are less serious than tox

Toxicity assessment in marine sediment for the Terra Nova environmental effects monitoring program (1997-2010)

NASA Astrophysics Data System (ADS)

Whiteway, Sandra A.; Paine, Michael D.; Wells, Trudy A.; DeBlois, Elisabeth M.; Kilgour, Bruce W.; Tracy, Ellen; Crowley, Roger D.; Williams, Urban P.; Janes, G. Gregory

2014-12-01

This paper discusses toxicity test results on sediments from the Terra Nova offshore oil development. The Terra Nova Field is located on the Grand Banks approximately 350 km southeast of Newfoundland (Canada). The amphipod (Rhepoxynius abronius) survival and solid phase luminescent bacteria (Vibrio fischeri, or Microtox) assays were conducted on sediment samples collected from approximately 50 stations per program year around Terra Nova during baseline (1997), prior to drilling, and in 2000, 2001, 2002, 2004, 2006, 2008 and 2010 after drilling began. The frequency of toxic responses in the amphipod toxicity test was low. Of the ten stations that were toxic in environmental effects monitoring (EEM) years, only one (station 30(FE)) was toxic in more than one year and could be directly attributed to Terra Nova project activities. In contrast, 65 (18%) of 364 EEM samples were toxic to Microtox. Microtox toxicity in EEM years was not related to distance from Terra Nova drill centres or concentrations of >C10-C21 hydrocarbons or barium, the primary constituents of the synthetic-based drill muds used at Terra Nova. Of the variables tested, fines and strontium levels showed the strongest (positive) correlations with toxicity. Neither fines nor strontium levels were affected by drill cuttings discharge at Terra Nova, except at station 30(FE) (and that station was not toxic to Microtox). Benthic macro-invertebrate abundance, richness and diversity were greater in toxic than in non-toxic sediments. Therefore, Microtox responses indicating toxicity were associated with positive biological responses in the field. This result may have been an indirect function of the increased abundance of most invertebrate taxa in less sandy sediments with higher gravel content, where fines and strontium levels and, consequently, toxicity to Microtox were high; or chemical substances released by biodegradation of organic matter, where invertebrates are abundant, may be toxic to Microtox. Given

Acute toxicity and hazard assessment of Rodeo®, X-77 Spreader®, and Chem-Trol® to aquatic invertebrates

USGS Publications Warehouse

Henry, C. J.; Higgins, K. F.; Buhl, K.J.

1994-01-01

The herbicide Rodeo® provides waterfowl managers with an effective chemical tool for creating open water habitats in wetlands if its use does not adversely affect native invertebrate communities. The survival of caged Chironomus spp. (midge), Hyalella azteca (amphipod),Stagnicola elodes (pond snail), and Nephelopsis obscura (leech) was assessed in prairie pothole wetlands treated by air with a tank mixture of Rodeo®, the surfactant X-77 Spreader®, and the drift retardant Chem-Trol® at a rate recommended for controlling cattails. Laboratory studies were then conducted to determine the acute toxicities of Rodeo®, X-77 Spreader®, and Chem-Trol®, individually and in simulated tank mixtures, to the same invertebrates and to Daphnia magna in reconstituted water representative of these wetlands. There was no difference in the survival of caged invertebrates between treated and reference wetlands after 21 days. Based on nominal concentrations of the formulations, X-77 Spreader® (LC50s=2.0–14.1 mg/L) was about 83–136 times more toxic than Rodeo® (LC50s=218–1216 mg/L) to aquatic invertebrates. Chem-Trol® killed ≤10% of the animals at 10,000 mg/L and ≤50% of the animals at 28,000 mg/L. Daphnia magna were more sensitive than the other species to X-77 Spreader®, Rodeo®, and the simulated Rodeo® tank mixture (RTM). The joint toxic action of the RTM was additive for amphipods and midges, greater than additive for leeches, and was less than additive for daphnids. X-77 Spreader® was the major toxic component in the RTM. Binary mixtures of X-77 Spreader®, Rodeo®, and Chem-Trol® at tank mixture and equitoxic ratios also showed additive toxicity to amphipods. The use of Rodeo® (applied as a tank mixture with X-77 Spreader® and Chem-Trol®) as a management tool in wetlands does not pose an acute hazard to native aquatic invertebrates because the concentrations of Rodeo®, X-77 Spreader®, and Chem-Trol® found to be acutely toxic to these invertebrates were

Toxicity of sediments potentially contaminated by coal mining and natural gas extraction to unionid mussels and commonly tested benthic invertebrates

USGS Publications Warehouse

Wang, Ning; Ingersoll, Christopher G.; Kunz, James L.; Brumbaugh, William G.; Kane, Cindy M.; Evans, R. Brian; Alexander, Steven; Walker, Craig; Bakaletz, Steve

2013-01-01

Sediment toxicity tests were conducted to assess potential effects of contaminants associated with coal mining or natural gas extraction activities in the upper Tennessee River basin and eastern Cumberland River basin in the United States. Test species included two unionid mussels (rainbow mussel, Villosa iris, and wavy-rayed lampmussel, Lampsilis fasciola, 28-d exposures), and the commonly tested amphipod, Hyalella azteca (28-d exposure) and midge, Chironomus dilutus (10-d exposure). Sediments were collected from seven test sites with mussel communities classified as impacted and in proximity to coal mining or gas extraction activities, and from five reference sites with mussel communities classified as not impacted and no or limited coal mining or gas extraction activities. Additional samples were collected from six test sites potentially with high concentrations of polycyclic aromatic hydrocarbons (PAHs) and from a test site contaminated by a coal ash spill. Mean survival, length, or biomass of one or more test species was reduced in 10 of 14 test samples (71%) from impacted areas relative to the response of organisms in the five reference samples. A higher proportion of samples was classified as toxic to mussels (63% for rainbow mussels, 50% for wavy-rayed lampmussels) compared with amphipods (38%) or midge (38%). Concentrations of total recoverable metals and total PAHs in sediments did not exceed effects-based probable effect concentrations (PECs). However, the survival, length, or biomasses of the mussels were reduced significantly with increasing PEC quotients for metals and for total PAHs, or with increasing sum equilibrium-partitioning sediment benchmark toxic units for PAHs. The growth of the rainbow mussel also significantly decreased with increasing concentrations of a major anion (chloride) and major cations (calcium and magnesium) in sediment pore water. Results of the present study indicated that (1) the findings from laboratory tests were generally

Grandidierella bonnieroides Stephensen, 1948 (Amphipoda, Aoridae)-first record of an established population in the Mediterranean Sea.

PubMed

Brutto, Sabrina Lo; Iaciofano, Davide; Lubinevsky, Hadas; Galil, Bella S

2016-03-17

The first record in the Mediterranean Sea of the invasive aorid amphipod crustacean Grandidierella bonnieroides is presented. A widespread circumtropical species, recorded off the Saudi coast of the Arabian Gulf, the Red Sea and the Suez Canal, it may have been introduced into the Mediterranean through the Suez Canal. This tube-builder species of soft bottoms recently established a population in the polluted Haifa Bay, Israel. Further, this is the first Mediterranean record of the genus.

Northwestward range extension for Diacyclops harryi (Crustacea: Copepoda)

USGS Publications Warehouse

Reid, Janet W.; Hudson, Patrick L.; Bowen, Charles A.

2002-01-01

A recent find of the groundwater-inhabiting copepod crustacean Diacyclops harryi extended the known range of this species far northwestward, to include northern Ohio and the drainage basin of the Laurentian Great Lakes. The species was previously collected in drainages of the Atlantic Slope from New York to North Carolina. Ostracodes tentatively identified as ?Nannocandona n. sp., and amphipods belonging to the subterranean species Bactrurus mucronatus were also found at the Ohio locality.

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...

A genetic fingerprint of Amphipoda from Icelandic waters – the baseline for further biodiversity and biogeography studies

PubMed Central

Jażdżewska, Anna M.; Corbari, Laure; Driskell, Amy; Frutos, Inmaculada; Havermans, Charlotte; Hendrycks, Ed; Hughes, Lauren; Lörz, Anne-Nina; Bente Stransky; Tandberg, Anne Helene S.; Vader, Wim; Brix, Saskia

2018-01-01

Abstract Amphipods constitute an abundant part of Icelandic deep-sea zoobenthos yet knowledge of the diversity of this fauna, particularly at the molecular level, is scarce. The present work aims to use molecular methods to investigate genetic variation of the Amphipoda sampled during two IceAGE collecting expeditions. The mitochondrial cytochrome oxidase subunit 1 (COI) of 167 individuals originally assigned to 75 morphospecies was analysed. These targeted morhospecies were readily identifiable by experts using light microscopy and representative of families where there is current ongoing taxonomic research. The study resulted in 81 Barcode Identity Numbers (BINs) (of which >90% were published for the first time), while Automatic Barcode Gap Discovery revealed the existence of 78 to 83 Molecular Operational Taxonomic Units (MOTUs). Six nominal species (Rhachotropis helleri, Arrhis phyllonyx, Deflexilodes tenuirostratus, Paroediceros propinquus, Metopa boeckii, Astyra abyssi) appeared to have a molecular variation higher than the 0.03 threshold of both p-distance and K2P usually used for amphipod species delineation. Conversely, two Oedicerotidae regarded as separate morphospecies clustered together with divergences in the order of intraspecific variation. The incongruence between the BINs associated with presently identified species and the publicly available data of the same taxa was observed in case of Paramphithoe hystrix and Amphilochus manudens. The findings from this research project highlight the necessity of supporting molecular studies with thorough morphology species analyses. PMID:29472762

Experimental evidence of chemical defence mechanisms in Antarctic bryozoans.

PubMed

Figuerola, Blanca; Angulo-Preckler, Carlos; Núñez-Pons, Laura; Moles, Juan; Sala-Comorera, Laura; García-Aljaro, Cristina; Blanch, Anicet R; Avila, Conxita

2017-08-01

Bryozoans are among the most abundant and diverse members of the Antarctic benthos, however the role of bioactive metabolites in ecological interactions has been scarcely studied. To extend our knowledge about the chemical ecology of Antarctic bryozoans, crude ether extracts (EE) and butanol extracts (BE) obtained from two Antarctic common species (Cornucopina pectogemma and Nematoflustra flagellata), were tested for antibacterial and repellent activities. The extracts were screened for quorum quenching and antibacterial activities against four Antarctic bacterial strains (Bacillus aquimaris, Micrococcus sp., Oceanobacillus sp. and Paracoccus sp.). The Antarctic amphipod Cheirimedon femoratus and the sea star Odontaster validus were selected as sympatric predators to perform anti-predatory and substrate preference assays. No quorum quenching activity was detected in any of the extracts, while all EE exhibited growth inhibition towards at least one bacterium strain. Although the species were not repellent against the sea star, they caused repellence to the amphipods in both extracts, suggesting that defence activities against predation derive from both lipophilic and hydrophilic metabolites. In the substrate preference assays, one EE and one BE deriving from different specimens of the species C. pectogemma were active. This study reveals intraspecific variability of chemical defences and supports the fact that chemically mediated interactions are common in Antarctic bryozoans as means of protection against fouling and predation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Does Waterborne Exposure Explain Effects Caused by Neonicotinoid-Contaminated Plant Material in Aquatic Systems?

PubMed

Englert, Dominic; Zubrod, Jochen P; Link, Moritz; Mertins, Saskia; Schulz, Ralf; Bundschuh, Mirco

2017-05-16

Neonicotinoids are increasingly applied on trees as protection measure against insect pests. Consequently, neonicotinoids are inevitably transferred into aquatic environments either via spray drift or surface runoff or (due to neonicotinoids' systemic nature) via senescent leaves. There particularly leaf-shredding invertebrates may be exposed to neonicotinoids through both the water phase and the consumption of contaminated leaves. In 7 day bioassays (n = 30), we examined ecotoxicological differences between these two exposure scenarios for an amphipod and an insect nymph with their feeding rate as the response variable. Organisms either experienced waterborne neonicotinoid (i.e., imidacloprid, thiacloprid, and acetamiprid) exposure only or a combined exposure (waterborne and dietary) through both the consumption of contaminated leaves and neonicotinoids leaching from leaves into water. The amphipod (7 day EC 50 s from 0.3 to 8.4 μg/L) was more sensitive than the insect nymph (7 day EC 50 s from 7.0 to 19.4 μg/L). Moreover, for both species, concentration-response models derived from water concentrations indicated higher effects under the combined exposure. Together with the observed inability of shredders to avoid neonicotinoid-contaminated leaves, our results emphasize the relevance of dietary exposure (e.g., via leaves) for systemic insecticides. Thus, it would be prudent to consider dietary exposure during the registration of systemic insecticides to safeguard ecosystem integrity.

Effect of Roundup® (glyphosate formulation) in the energy metabolism and reproductive traits of Hyalella castroi (Crustacea, Amphipoda, Dogielinotidae).

PubMed

Dutra, Bibiana Kaiser; Fernandes, Felipe Amorim; Failace, Daniela Motta; Oliveira, Guendalina Turcato

2011-01-01

Roundup(®) (glyphosate formulation) is a nonselective and posts emergent herbicide used for controlling aquatic weeds and different concentrations are used in cultures around the world. The objective of this investigation was to examine the effects of Roundup(®) (glyphosate formulation) on the biochemical composition, levels of lipoperoxidation, Na(+)/K(+)ATPase activity and reproductive traits in the Hyalella castroi. Amphipods were collected in summer 2009, in the southern Brazilian highlands. In the laboratory, the animals were kept in aquariums under controlled conditions for 7 days, and after this period they were exposed to 0.36, 0.52, 1.08 and 2.16 mg/l of glyphosate for 7 days. After the period of exposure, the animals were immediately frozen for determination of glycogen, proteins, lipids, triglycerides, cholesterol, levels of lipoperoxidation, and Na(+)/K(+)ATPase activity. During each day of the cultivation reproductive traits (number of reproductive pairs, ovigerous females and eggs in the marsupium) were observed. All concentrations of Roundup(®) induced significant decreases in all biochemical parameters and Na(+)/K(+)ATPase activity, and significant increase in lipoperoxidation levels. Showing this form a potentially toxic effect at very low concentrations, this pattern of results can lead to significant changes in trophic structure of limnic environments because these amphipods are important links in food chain in these habitats.

Metal-Polycyclic Aromatic Hydrocarbon Mixture Toxicity in Hyalella azteca. 1. Response Surfaces and Isoboles To Measure Non-additive Mixture Toxicity and Ecological Risk.

PubMed

Gauthier, Patrick T; Norwood, Warren P; Prepas, Ellie E; Pyle, Greg G

2015-10-06

Mixtures of metals and polycyclic aromatic hydrocarbons (PAHs) occur ubiquitously in aquatic environments, yet relatively little is known regarding their potential to produce non-additive toxicity (i.e., antagonism or potentiation). A review of the lethality of metal-PAH mixtures in aquatic biota revealed that more-than-additive lethality is as common as strictly additive effects. Approaches to ecological risk assessment do not consider non-additive toxicity of metal-PAH mixtures. Forty-eight-hour water-only binary mixture toxicity experiments were conducted to determine the additive toxic nature of mixtures of Cu, Cd, V, or Ni with phenanthrene (PHE) or phenanthrenequinone (PHQ) using the aquatic amphipod Hyalella azteca. In cases where more-than-additive toxicity was observed, we calculated the possible mortality rates at Canada's environmental water quality guideline concentrations. We used a three-dimensional response surface isobole model-based approach to compare the observed co-toxicity in juvenile amphipods to predicted outcomes based on concentration addition or effects addition mixtures models. More-than-additive lethality was observed for all Cu-PHE, Cu-PHQ, and several Cd-PHE, Cd-PHQ, and Ni-PHE mixtures. Our analysis predicts Cu-PHE, Cu-PHQ, Cd-PHE, and Cd-PHQ mixtures at the Canadian Water Quality Guideline concentrations would produce 7.5%, 3.7%, 4.4% and 1.4% mortality, respectively.

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

Dean, T.A.; Bellis, V.J.

Epifaunal species were collected at 1-, 3-, and 12-month intervals from the Pamlico River estuary. Three epifaunal communities were recognized by characteristic species assemblages. The permanently mesohaline mouth was dominated by Garveia cerulea (hydroid), Balanus improvisus (barnacle), Victorella pavida and Membranipora tenuis (bryozoans), Diadumene leucolena (anemone), Ercolania vanellus (nudibranch), Corophium lacustre (amphipod), and Polydora websteri and Nereis succinea (polychaetes). Upriver, in oligohaline portions, dominants were Cordylophora caspia (hydroid), Balanus subalbidus and Balanus improvisus (barnacles), Victorella pavida (bryozoan), and Polydora websteri (polychaete). Between these extremes, the intermediate zone was dominated by representatives of the extremes: Balanus improvisus, Cordylophora caspia, Victorella pavida,more » Corophium lacustre (amphipod), and Polydora websteri. Demarcation of communities corresponded to salinity patterns. Within each community wide seasonal variation was demonstrated by species composition, relative abundance, and dry weight. Epifauna were most abundant in warm months (May to October) and relatively sparse the rest of the year. Seasonal expression of community structure was attributed to periodicity in larval release and settlement and was thus initiated and directed by the annual pattern of water temperature, dissolved oxygen, salinity, and interspecific competition. The sequence of epifaunal dominants began with barnacles and hydroids in the spring, a bryozoan in summer, and a smaller set of barnacles with associated tubeworms in fall. Community succession began with bacteria and protozoans followed by sessile epifauna and finally motile epifaunal associates.« less

The use of Ampelisca abdita growth rate as an indicator of sediment quality

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

Weston, D.P.; Thompson, B.

1995-12-31

Acute lethal bioassays with amphipod crustaceans are routinely used to assess toxicity of bulk sediments. A study within the San Francisco Bay Regional Monitoring Program (RMP) is in progress to develop a chronic bioassay with the amphipod Ampelisca abdita, measuring both survivorship and growth rates. This approach is attractive because depression of growth rate is likely to be a more sensitive indicator of toxic effects than acute lethality, and natural populations of A. abdita exist throughout the Bay. Spiked sediment bioassays, using cadmium and crude oil, were used to demonstrate the relative sensitivity of the standard 10-day lethal test vs.more » the 30-day growth test. Sediments were also collected from 9 sites throughout the Bay, ranging from areas adjacent to municipal wastewater discharges to areas distant from known point source inputs. These samples were then split, and used for side-by-side comparison of acute (lethal) and chronic (growth) toxicity tests. Survivorship exceeded 90% in all tests, including those sediments collected nearest the wastewater outfalls. Growth rates were contrasted among the various treatments to examine the utility of this end point in discriminating the outfall sites. Data on the spatial distribution, abundance, and size-frequency distribution of native populations was examined within the context of using growth rate as an indicator of toxic effects in natural populations as well.« less

Landscape ecology of interactions between seagrass and mobile epifauna: The matrix matters

NASA Astrophysics Data System (ADS)

Tanner, Jason E.

2006-07-01

There is increasing interest among ecologists about how the type of matrix surrounding a habitat patch influences the organisms living in that patch. This question is virtually unstudied in marine systems. In this paper I show that the mobile faunal assemblage in seagrass patches does depend on the surrounding matrix. Faunal assemblages in patches of Posidonia surrounded by sand are different than in those surrounded by Heterozostera, another seagrass, having more than double the abundance of both amphipods and polychaetes. However, the differences are not simply due to spillover from the matrix habitat, but rather are an emergent property of the patch context that cannot be predicted. Posidonia surrounded by sand actually has an assemblage that is intermediate between Heterozostera and Posidonia surrounded by Heterozostera. Differences in habitat structure do not account for this pattern, as seagrass biomass did not vary, and the same result was found in artificial seagrass. The faunal assemblage did not vary depending on the location within the patch (edge or centre) for Heterozostera, Posidonia or artificial seagrass. Patch size, however, did have an effect for Heterozostera, with smaller patches having 2-3 times as many isopods per sample as large, but less than half the number of some amphipod families. These results suggest that the landscape context is as important in marine systems as it is known to be in terrestrial systems.

NASA finds Shrimp Under Antarctic Ice [Video

NASA Image and Video Library

2017-12-08

At a depth of 600 feet beneath the West Antarctic ice sheet, a small shrimp-like creature managed to brighten up an otherwise gray polar day in late November 2009. This critter is a three-inch long Lyssianasid amphipod found beneath the Ross Ice Shelf, about 12.5 miles away from open water. NASA scientists were using a borehole camera to look back up towards the ice surface when they spotted this pinkish-orange creature swimming beneath the ice. Credit: NASA

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

First record of the invasive and cryptogenic species Jassa slatteryiConlan, 1990 (Crustacea: Amphipoda) in Italian coastal waters

NASA Astrophysics Data System (ADS)

Bonifazi, Andrea; Mancini, Emanuele; Ventura, Daniele

2018-06-01

Jassa slatteryi is a cosmopolitan amphipod reported as cryptogenic or invasive species throughout the world. Although it had been signaled in the Mediterranean Sea, it was never found on the Italian coasts. This study represents the first record of J. slatteryi in Italy. A total of 87 specimens were collected on artificial hard substrates in the Port of Civitavecchia (Rome). The presence of this species in the Mediterranean Sea was probably underestimated due to the similar morphological features and ecological requirements of different species of Jassa spp.

The occurrence of Ophiocnemis marmorata (Echinodermata: Ophiuroidea) associated with the rhizostome medusa Rhopilema hispidum (Cnidaria: Scyphozoa)

NASA Astrophysics Data System (ADS)

Kanagaraj, Govindan; Kumar, Pithchai Sampath; Morandini, André C.

2008-11-01

The association of scyphomedusae with invertebrates has been long known in the literature; especially with hyperiids amphipods. The association of echinoderms with jellyfish is not common and rarely recorded. We reported the association of the ophiuroid Ophiocnemis marmorata with the rhizostome scyphomedusa Rhopilema hispidum collected in Vellar estuary (on the southeast coast of India). O. marmorata is supposed to be a filter feeding ophiuroid, quite common in soft bottom of shallow waters. The brittle stars possibly seek for food supply, shelter and protection through the association.

Assimilation and subcellular partitioning of elements by grass shrimp collected along an impact gradient.

PubMed

Seebaugh, David R; Wallace, William G

2009-06-28

Chronic exposure to polluted field conditions can impact metal bioavailability in prey and may influence metal transfer to predators. The present study investigated the assimilation of Cd, Hg and organic carbon by grass shrimp Palaemonetes pugio, collected along an impact gradient within the New York/New Jersey Harbor Estuary. Adult shrimp were collected from five Staten Island, New York study sites, fed (109)Cd- or (203)Hg-labeled amphipods or (14)C-labeled meals and analyzed for assimilation efficiencies (AE). Subsamples of amphipods and shrimp were subjected to subcellular fractionation to isolate metal associated with a compartment presumed to contain trophically available metal (TAM) (metal associated with heat-stable proteins [HSP - e.g., metallothionein-like proteins], heat-denatured proteins [HDP - e.g., enzymes] and organelles [ORG]). TAM-(109)Cd% and TAM-(203)Hg% in radiolabeled amphipods were approximately 64% and approximately 73%, respectively. Gradients in AE-(109)Cd% ( approximately 54% to approximately 75%) and AE-(203)Hg% ( approximately 61% to approximately 78%) were observed for grass shrimp, with the highest values exhibited by shrimp collected from sites within the heavily polluted Arthur Kill complex. Population differences in AE-(14)C% were not observed. Assimilated (109)Cd% partitioned to the TAM compartment in grass shrimp varied between approximately 67% and approximately 75%. (109)Cd bound to HSP in shrimp varied between approximately 15% and approximately 47%, while (109)Cd associated with metal-sensitive HDP was approximately 17% to approximately 44%. Percentages of assimilated (109)Cd bound to ORG were constant at approximately 10%. Assimilated (203)Hg% associated with TAM in grass shrimp did not exhibit significant variation. Percentages of assimilated (203)Hg bound to HDP ( approximately 47%) and ORG ( approximately 11%) did not vary among populations and partitioning of (203)Hg to HSP was not observed. Using a simplified biokinetic

Comparative feeding ecology of abyssal and hadal fishes through stomach content and amino acid isotope analysis

NASA Astrophysics Data System (ADS)

Gerringer, M. E.; Popp, B. N.; Linley, T. D.; Jamieson, A. J.; Drazen, J. C.

2017-03-01

The snailfishes, family Liparidae (Scorpaeniformes), have found notable success in the hadal zone from 6000-8200 m, comprising the dominant ichthyofauna in at least five trenches worldwide. Little is known about the biology of these deepest-living fishes, nor the factors that drive their success at hadal depths. Using recent collections from the Mariana Trench, Kermadec Trench, and neighboring abyssal plains, this study investigates the potential role of trophic ecology in structuring fish communities at the abyssal-hadal boundary. Stomach contents were analyzed from two species of hadal snailfishes, Notoliparis kermadecensis and a newly-discovered species from the Mariana Trench. Amphipods comprised the majority (Kermadec: 95.2%, Mariana: 97.4% index of relative importance) of stomach contents in both species. Decapod crustaceans, polychaetes (N. kermadecensis only), and remains of carrion (squid and fish) were minor dietary components. Diet analyses of abyssal species (families Macrouridae, Ophidiidae, Zoarcidae) collected from near the trenches and the literature are compared to those of the hadal liparids. Stomachs from abyssal fishes also contained amphipods, however macrourids had a higher trophic plasticity with a greater diversity of prey items, including larger proportions of carrion and fish remains; supporting previous findings. Suction-feeding predatory fishes like hadal liparids may find an advantage to descending into the trench - where amphipods are abundant. More generalist feeders and scavengers relying on carrion, such as macrourids, might not benefit from this nutritional advantage at hadal depths. Compound specific isotope analysis of amino acids was used to estimate trophic level of these species (5.3±0.2 Coryphaenoides armatus, 5.2±0.2 C. yaquinae, 4.6±0.2 Spectrunculus grandis, 4.2±0.2 N. kermadecensis, 4.4±0.2 Mariana snailfish). Source amino acid δ15N values were especially high in hadal liparids (8.0±0.3‰ Kermadec, 6.7±0.2�

The effects of ultraviolet-B radiation on freshwater invertebrates: Experiments with a solar simulator

USGS Publications Warehouse

Hurtubise, R.D.; Havel, J.E.; Little, E.E.

1998-01-01

There is concern that decreases in stratospheric ozone will lead to hazardous levels of ultraviolet-B (UV-B) radiation at the Earth's surface. In clear water, UV-B may penetrate to significant depths. The purpose of the current study was to compare the sensitivity of freshwater invertebrates to UV-B. We used a solar simulator, calibrated to match local ambient solar radiation, to expose five species of freshwater invertebrates to enhanced levels of UV-B radiation. UV-B measurements in a eutrophic pond revealed that 10% of the irradiance penetrated to 30-cm depth and 1% to 57-cm depth. The irradiance at the upper 5-20 cm was comparable to levels used in the simulator. Median lethal dose (LD50) values were determined for the cladocerans Ceriodaphnia reticulata, Scapholeberis kingii (two induced color morphs), and Daphnia magna; the ostracod Cyprinotus incongruens; and the amphipod Hyalella azteca. Among the species, 96-h LD50 estimates were quite variable, ranging from 4.2 to 84.0 ??W cm-2. These estimates indicated S. kingii to be highly sensitive and H. azteca, C. reticulata, and D. magna to be moderately sensitive, whereas the ostracod C. incongruens was very tolerant to UV-B radiation. Overall, this study suggests that, in shallow ponds without physical refuges, UV-B radiation would have the strongest effects upon cladocerans and amphipods occurring in the water column, whereas ostracods would be better protected.

Use of porewater extracts to identify the cause of toxicity in marine and estuarine sediments

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

Douglas, W.S.

1994-12-31

Amphipod toxicity tests in the evaluation of dredged material proposed for ocean disposal has come under increased scrutiny by the regulated community in the Port of NY/NJ. In recent large-scale assessments of sediment quality in the harbor, the vast majority of locations were deemed highly contaminated when tested with Ampelisca abdita. Toxicity tests, by themselves, do not provide data regarding the cause of toxicity of these sediments. The enormous potential costs associated with most proposed alternatives to ocean disposal of dredged sediments has prompted the investigation of the causative agents of toxicity in sediments of the NY/NJ Harbor. Sediment frommore » five locations in the harbor, selected in consultation with local regulatory agencies to represent diverse potential contamination scenarios, was collected and tested for toxicity to the amphipods Ampelisca abdita, Leptocheirus plumulosus, Eohaustorius estuadus, Rhepoxynius abronius, and the mysid shrimp, Mysidopsis bahia, using 10-day static bioassays. Porewater from each of the five sediments was extracted under centrifugation and used in water-only toxicity tests with A. abdita, L. plumulosus, R. abronius, E. estuadus, M. bahia, M. beryllina, and Microtox. A Phase 1 Toxicity Identification Evaluation of the three most toxic porewater samples was conducted using several of the species tested. Results from the preliminary investigations and the ongoing TIE`s will be presented. Species selection, porewater toxicity test procedures, and Phase 1, 2, and 3 paradigms will be discussed.« less

Interactions between macro-algal mats and invertebrates in the Ythan estuary, Aberdeenshire, Scotland

NASA Astrophysics Data System (ADS)

Raffaelli, D.

2000-07-01

Blooms of opportunistic green macro-algae are a common feature of coastal areas and their effects on mudflat invertebrates can be dramatic. On the Ythan estuary, Aberdeenshire, Scotland, we have carried out a number of manipulative field experiments designed to evaluate the effects on invertebrates of different species of macro-algae with contrasting ecologies, and the effects of invertebrates on the development of the blooms. Macro-algal mats were found to have dramatic nega- tive effects on the density of the amphipod Corophium volutator, with higher algal biomasses having greater impact. The mechanism for this interaction seems to be interference by the algal filaments with the feeding behaviour of the amphipod. In contrast, the polychaete Capitella spp. increases in abundance under macro-algal mats due to enrichment of the sediment with organic material. These two interactions are seen at all scales, in areas of less than 1 m2 to the scale of the entire estuary, irrespective of the species composition of the macro- algal mats. Bioturbation by Corophium and grazing by the snail Hydrobia ulvae had little effect on macro-algal biomass, but there were less algae when the polychaete Nereis diversicolor was present. The most significant interaction in this system is the pronounced negative impact of algal mats on the abundance of Corophium, probably the most important invertebrate species in the diets of the estuary's shorebirds, fish and epibenthic crustaceans.

Effects of a fungicide (imazalil) and an insecticide (diazinon) on stream fungi and invertebrates associated with litter breakdown.

PubMed

Flores, L; Banjac, Z; Farré, M; Larrañaga, A; Mas-Martí, E; Muñoz, I; Barceló, D; Elosegi, A

2014-04-01

The intensification of agriculture has promoted the use of pesticides such as fungicides and insecticides. Many pesticides readily leach into natural water bodies and affect both organisms and ecosystem processes such as leaf breakdown, a crucial process in headwater streams. As leaf breakdown in streams involves sequential steps by different groups of organisms (first microbial conditioning, then invertebrate shredding), pesticides targeting different organisms are likely to affect one or the other step, and a mixture of contaminants might have interactive effects. Our objective was to evaluate the effect of a fungicide (imazalil) and an insecticide (diazinon) on stream fungal and invertebrate activities, and their effects on leaf consumption. After an initial assay to define 'effective concentration' of both pesticides in a laboratory experiment, we manipulated pesticide presence/absence during the conditioning and shredding phases. Both pesticides affected fungal community and reduced the performance of the shredding amphipod Echinogammarus berilloni, and leaf consumption. The impact of pesticides on fungal sporulation depended on the length of the exposure period. In addition, pesticides seemed to cause an energetic imbalance in the amphipod, affecting body condition and mortality. The combined effect of both pesticides was similar to those of the fungicide. Overall, our results show that the effects of pesticide mixtures on leaf breakdown are hard to predict from those observed in either fungi or macroinvertebrate performance. Copyright © 2014 Elsevier B.V. All rights reserved.

Populations, feeding ecology and molt of Steller's Eiders

USGS Publications Warehouse

Petersen, Margaret R.

1981-01-01

This study considers the temporal and spatial distribution of Steller's Eiders (Polysticta stelleri) during molt along the north side of the Alaska Peninsula from Port Heiden to Bechevin Bay. Subadult eiders molted primarily at Nelson Lagoon, adult males at Nelson Lagoon and Izembek Bay, and adult females primarily at Izembek Bay. Only a few eiders used Bechevin Bay, Seal Islands, and Port Heiden. Although the flightless period overlapped among different age and sex classes, subadults were flightless first, then adult males, and last, adult females. Eiders maintained spatial and temporal separation during the flightless period, thereby reducing competition for food resources.Eiders at Nelson Lagoon were observed feeding only by head-dipping during the pre-flightless period in 1979, a significant change from 1977 when they fed both by diving and dipping. During both 1977 and 1979 eiders foraged for approximately equal amounts of time during each stage of molt. Foods consisted primarily of bivalve mollusks and amphipods. These foods were consumed in different proportions before and after the wing-feather molt, with mussels being most important when eiders were growing remiges. Comparisons between the amount of energy in blue mussels (Mytilus edulis), clams (Macoma balthica), and gammarid amphipods showed that mussels yield the most energy per gram of whole wet weight. Apparently Steller's Eiders have adjusted to the increased energy demands of molt by eating invertebrates with high caloric content, rather than by increasing the amount of time feeding.

The development of a site-specific water-quality standard for copper

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

Sinclair, R.M.

This dissertation proposes to determine, for one toxic chemical, copper, if the Federal water quality standard and the state interpretation of that standard are appropriate for the Duck River, some 50 miles south of Nashville, Tennessee. This involved conducting toxicity tests in Duck River water, and the use of the computer metal speciation program MINTEQA1 to predict instream impact. The speciation model chosen for the determination of chemical equilibria in this study was MINTEQA1. To test the validity of the MINTEQA1 speciation model, water chemistry from the Duck River was entered into the model. At the typical site pH ofmore » 7.8, 55.7% of the copper is bound as Cu(OH){sub 2}, 29.8% is bound as copper humate, and 12.7% is found as CuCO{sub 3}. Of extreme importance to the toxicity of copper in the site water is the complete absence of the most toxic species, ionic copper. The test species were the brook silversides minnow (Labidesthes sicculus), mosquitofish (Gambusia affinis), caddisfly larvae (Cheumatopsyche sp.), fathead minnow (Pimephales promelas), geniculate river snail (Lithasia geniculata), sunfish (Lepomis sp.), and the amphipod (Hyalella azeca). The test concentrations were confirmed by atomic absorption spectroscopy on selected concentrations. The caddisfly larvae was the single most tolerant species observed during this study, while the amphipod and snail were the two most sensitive species tested.« less

Growth and diet of fish in Waldo Lake, Oregon

USGS Publications Warehouse

Swanson, Nicola L.; Liss, W.J.; Ziller, Jeffrey S.; Wade, M.; Gresswell, R.E.

2000-01-01

Waldo Lake, located in the Oregon Cascades, is considered to be one of the most dilute lakes in the world. Even with low nutrient concentrations and sparse populations of zooplankton, introduced fish in the lake are large in size and in good condition when compared to fish from other lakes. This apparent anomaly is due to the availability of benthic macroinvertebrates. Taxa found in the stomach contents offish captured in Waldo Lake consist primarily of Chironomidae larvae and pupae, Trichoptera larvae and pupae, amphipods, Ephemeroptera larvae, and Odonata larvae.

Analysis of six groups of zooplankton in samples taken in 1978/79 at the proposed OTEC site in the eastern Gulf of Mexico off Tampa Bay

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

Flock, M.E.; Hopkins, T.L.

1981-05-01

Continued analysis has been made of the 33 zooplankton collections made at the proposed OTEC site in the Gulf of Mexico off Tampa Bay. Six groups of zooplankton - siphonophores (Calycophora), pteropods (Thecosomata), chaetognaths, thaliaceans, euphausiids and amphipods were quantitatively investigated. Numbers and biomass were determined for all taxa and diurnal, seasonal and depth trends were discussed. Considering the present study and the previous investigation of the copepod population, this proposed OTEC site is probably one of the faunistically better known locales in the Gulf of Mexico and Caribbean.

Molecular detection of viral agents in free-ranging and captive neotropical felids in Brazil.

PubMed

Furtado, Mariana M; Taniwaki, Sueli A; de Barros, Iracema N; Brandão, Paulo E; Catão-Dias, José L; Cavalcanti, Sandra; Cullen, Laury; Filoni, Claudia; Jácomo, Anah T de Almeida; Jorge, Rodrigo S P; Silva, Nairléia Dos Santos; Silveira, Leandro; Ferreira Neto, José S

2017-09-01

We describe molecular testing for felid alphaherpesvirus 1 (FHV-1), carnivore protoparvovirus 1 (CPPV-1), feline calicivirus (FCV), alphacoronavirus 1 (feline coronavirus [FCoV]), feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), and canine distemper virus (CDV) in whole blood samples of 109 free-ranging and 68 captive neotropical felids from Brazil. Samples from 2 jaguars ( Panthera onca) and 1 oncilla ( Leopardus tigrinus) were positive for FHV-1; 2 jaguars, 1 puma ( Puma concolor), and 1 jaguarundi ( Herpairulus yagouaroundi) tested positive for CPPV-1; and 1 puma was positive for FIV. Based on comparison of 103 nucleotides of the UL24-UL25 gene, the FHV-1 sequences were 99-100% similar to the FHV-1 strain of domestic cats. Nucleotide sequences of CPPV-1 were closely related to sequences detected in other wild carnivores, comparing 294 nucleotides of the VP1 gene. The FIV nucleotide sequence detected in the free-ranging puma, based on comparison of 444 nucleotides of the pol gene, grouped with other lentiviruses described in pumas, and had 82.4% identity with a free-ranging puma from Yellowstone Park and 79.5% with a captive puma from Brazil. Our data document the circulation of FHV-1, CPPV-1, and FIV in neotropical felids in Brazil.

Natural infection by endoparasites among free-living wild animals.

PubMed

Holsback, Luciane; Cardoso, Mauro José Lahm; Fagnani, Rafael; Patelli, Thaís Helena Constantino

2013-01-01

The objective of this study was to investigate the frequency of occurrence and variety of intestinal parasites among free-living wild animals. Fecal samples from wild mammals and birds at rehabilitation centers in the states of Mato Grosso do Sul and São Paulo were analyzed by sedimentation and flotation-centrifugation methods. Parasite eggs, oocysts, cysts and/or trophozoites were found in 71% of the samples. Cryptosporidium sp. oocysts were detected in fecal samples from oncillas (Leopardus tigrinus) and scaly-headed parrots (Pionus maximiliani). Giardia cysts were identified in the feces of a gray brocket (Mazama gouazoubira). Among the most common parasites found, there were eggs from Toxocara cati, Toxascaris leonina and Ancylostoma tubaeforme, and from Cestoda. Several Enterobius sp. eggs were found in the feces of red howler monkeys (Alouatta seniculus). It can be concluded from this study that despite the small number of samples, the diversity of parasites found was noteworthy. Additional information about parasite endofauna in wild animals is needed, since their presence might suggest that there could be proximity to and interactions with domestic animals and/or humans. In addition, further studies on parasites from free-living wild animals are of prime importance for understanding the intensity of anthropic changes in wild environments.

Seroprevalence of Toxoplasma gondii infection in captive mammals in three zoos in Mexico City, Mexico.

PubMed

Alvarado-Esquivel, Cosme; Gayosso-Dominguez, Edgar Arturo; Villena, Isabelle; Dubey, J P

2013-09-01

Antibodies to Toxoplasma gondii were determined in 167 mammals in three zoos in Mexico City, Mexico, using the modified agglutination test (MAT). Overall, antibodies to T. gondii were found in 89 (53.3%) of the 167 animals tested. Antibodies were found in 35 of 43 wild Felidae: 2 of 2 bobcats (Lynx rufus); 4 of 4 cougars (Puma concolor); 10 of 13 jaguars (Panthera onca); 5 of 5 leopards (Panthera pardus); 7 of 7 lions (Panthera leo); 2 of 3 tigers (Panthera tigris); 2 of 3 ocelots (Leopardus pardalis); 2 of 2 Sumatran tigers (Panthera tigris sumatrae); lof 2 Jaguarundi (Herpailurus jagouaroundi); but not in 0 of 2 oncillas (Leopardus tigrinus). Such high seroprevalence in wild felids is of public health significance because of the potential of oocyst shedding. Four of 6 New World primates (2 of 2 Geoffroy's spider monkeys [Ateles geoffroyi], 1 of 3 Patas monkeys [Erythrocebus patas], and 1 of 1 white-headed capuchin [Cebus capucinus]) had high MAT titers of 3,200, suggesting recently acquired infection; these animals are highly susceptible to clinical toxoplasmosis. However, none of these animals were ill. Seropositivity to T. gondii was found for the first time in a number of species.

Locomotory, ventilatory and metabolic responses of the subterranean Stenasellus virei (Crustacea, Isopoda) to severe hypoxia and subsequent recovery.

PubMed

Hervant, F; Mathieu, J; Messana, G

1997-02-01

The locomotory and ventilatory activities and the intermediary and energy metabolism modifications of the hypogean aquatic isopod crustacean Stenasellus virei were investigated in severe hypoxia (PO2 < 0.03 kPa) and subsequent recovery. The aims of this study were i) to determine why the subterranean species displayed a greater tolerance of hypoxia than numerous other epigean crustaceans, ii) to confirm previous results obtained with four hypogean and epigean crustaceans, iii) to compare the responses to severe hypoxia in hypogean amphipods and isopods, and iv) to better understand the ecological problems of the hypogean organisms survival in subterranean habitats. S. virei responded to experimental long-term, severe hypoxia with classical anaerobic metabolism mainly characterized by a decrease in adenosine triphosphate (ATP) and phosphagen, utilization of glycogen and glutamate, and accumulation of lactate and alanine. Lactate was also largely excreted by this organism, which is unusual for crustaceans in general. Compared to most other epigean crustaceans, the isopod S. virei showed high amounts of stored glycogen and arginine phosphate. These differences in glycogen and phosphagen stores, and the ability to reduce energetic expenditures linked to locomotion and ventilation, extended the survival of S. virei under experimental anaerobiosis. During recovery, the isopod S. virei showed a higher capacity for glyconeogenesis from lactate and a faster and total replenishment of ATP and arginine phosphate levels than epigean crustaceans. Data concerning responses to hypoxia and subsequent recovery in S. virei are similar to those previously obtained with two other hypogean amphipods, except that this isopod did not synthesize succinate in anaerobiosis.

Zebra mussel effects on benthic invertebrates: physical or biotic?

USGS Publications Warehouse

Botts, P. Silver; Patterson, Benjamin A.; Schloesser, Don W.

1996-01-01

In soft sediments, Dreissena spp. create firm substrate in the form of aggregates of living mussels (druses) that roll free on the sediments. Druses provide physical structure which increases habitat heterogeneity, and the mussels increase benthic organic matter through the production of pseudofeces and feces. Descriptive and experimental studies were used to determine: 1) whether the density of benthic invertebrates in soft sediments increased in the presence of druses, and 2) whether the invertebrate assemblage responded to the physical structure provided by a druse or to some biotic effect associated with the presence of living mussels. In core samples collected biweekly during summer in Presque Isle Bay, Erie, Pennsylvania, amphipods, chironomids, oligochaetes, turbellarians, and hydrozoans were significantly more abundant in sand with druses than in bare sand. When mesh bags containing either a living druse, non-living druse, or no druse were incubated in the bay for 33 d, we found that chironomids were significantly more abundant in treatments with living druses than with non-living druses, and in treatments with non-living druses than with no druse; turbellarians, amphipods, and hydrozoans were significantly more abundant in treatments with living or non-living druses than with no druse; oligochaetes showed no significant differences among treatments. This study demonstrates that most taxa of benthic invertebrates in soft substrate respond specifically to the physical structure associated with aggregates of mussel shells, but further study is needed to examine chironomid responses to some biotic effect dependent on the presence of living mussels.

Life History and Production of the Western Gray Whale's Prey, Ampelisca eschrichtii Krøyer, 1842 (Amphipoda, Ampeliscidae).

PubMed

Demchenko, Natalia L; Chapman, John W; Durkina, Valentina B; Fadeev, Valeriy I

2016-01-01

Ampelisca eschrichtii are among the most important prey of the Western North Pacific gray whales, Eschrichtius robustus. The largest and densest known populations of this amphipod occur in the gray whale's Offshore feeding area on the Northeastern Sakhalin Island Shelf. The remote location, ice cover and stormy weather at the Offshore area have prevented winter sampling. The incomplete annual sampling has confounded efforts to resolve life history and production of A. eschrichtii. Expanded comparisons of population size structure and individual reproductive development between late spring and early fall over six sampling years between 2002 and 2013 however, reveal that A. eschrichtii are gonochoristic, iteroparous, mature at body lengths greater than 15 mm and have a two-year life span. The low frequencies of brooding females, the lack of early stage juveniles, the lack of individual or population growth or biomass increases over late spring and summer, all indicate that growth and reproduction occur primarily in winter, when sampling does not occur. Distinct juvenile and adult size cohorts additionally indicate growth and juvenile production occurs in winter through spring under ice cover. Winter growth thus requires that winter detritus or primary production are critical food sources for these ampeliscid populations and yet, the Offshore area and the Eastern Sakhalin Shelf ampeliscid communities may be the most abundant and productive amphipod population in the world. These A. eschrichtii populations are unlikely to be limited by western gray whale predation. Whether benthic community structure can limit access and foraging success of western gray whales is unclear.

Characterization of selected bed-sediment-bound organic and inorganic contaminants and toxicity, Barnegat Bay and major tributaries, New Jersey, 2012

USGS Publications Warehouse

Romanok, Kristin M.; Reilly, Timothy J.; Lopez, Anthony R.; Trainor, John J.; Hladik, Michelle; Stanley, Jacob K.; Farrar, Daniel

2014-01-01

A study of bed-sediment toxicity and organic and inorganic contaminants was conducted by the U.S. Geological Survey (USGS) in cooperation with the New Jersey Department of Environmental Protection (NJDEP). Bed-sediment samples were collected once from 22 sites in Barnegat Bay and selected major tributaries during August–September 2012 and analyzed for toxicity and a suite of organic and inorganic contaminants by the USGS and the U.S. Army Corps of Engineers. Sampling sites were selected to coincide with an existing water-quality monitoring network used by the NJDEP and others in order to evaluate water-quality conditions in Barnegat Bay and the surrounding watershed. Two of the 22 sites are reference sites and are within or adjacent to the study area; bed-sediment samples from reference sites allow for comparisons of results for the Barnegat Bay watershed to results from less affected settings within the region. Toxicity testing was conducted by exposing the estuarine amphipod Leptocheirus plumulosus and the freshwater amphipod Hyalella azteca to sediments for 28 days, and the percent survival, difference in biomass, and individual dry weights were measured. Reproductive effects also were evaluated for estuarine samples. Bed-sediment samples from four sites within Barnegat Bay were subjected to a toxicity identification evaluation to determine probable causes of toxicity. Samples were analyzed for a suite of 94 currently-used pesticides, 21 legacy pesticides, 24 trace elements, 40 polycyclic aromatic hydrocarbons, 7 polychlorinated biphenyls (PCBs) as Arochlor mixtures, and 145 individual PCB congeners. Concentrations of detected compounds were compared to sediment-quality guidelines, where appropriate.

Responses of Hyalella azteca to acute and chronic microplastic exposures.

PubMed

Au, Sarah Y; Bruce, Terri F; Bridges, William C; Klaine, Stephen J

2015-11-01

Limited information is available on the presence of microplastics in freshwater systems, and even less is known about the toxicological implications of the exposure of aquatic organisms to plastic particles. The present study was conducted to evaluate the effects of microplastic ingestion on the freshwater amphipod, Hyalella azteca. Hyalella azteca was exposed to fluorescent polyethylene microplastic particles and polypropylene microplastic fibers in individual 250-mL chambers to determine 10-d mortality. In acute bioassays, polypropylene microplastic fibers were significantly more toxic than polyethylene microplastic particles; 10-d lethal concentration 50% values for polyethylene microplastic particles and polypropylene microplastic fibers were 4.64 × 10(4) microplastics/mL and 71.43 microplastics/mL, respectively. A 42-d chronic bioassay using polyethylene microplastic particles was conducted to quantify effects on reproduction, growth, and egestion. Chronic exposure to polyethylene microplastic particles significantly decreased growth and reproduction at the low and intermediate exposure concentrations. During acute exposures to polyethylene microplastic particles, the egestion times did not significantly differ from the egestion of normal food materials in the control; egestion times for polypropylene microplastic fibers were significantly slower than the egestion of food materials in the control. Amphipods exposed to polypropylene microplastic fibers also had significantly less growth. The greater toxicity of microplastic fibers than microplastic particles corresponded with longer residence times for the fibers in the gut. The difference in residence time might have affected the ability to process food, resulting in an energetic effect reflected in sublethal endpoints. © 2015 SETAC.

Gray whale and walrus feeding excavation on the Bering Shelf, Alaska.

USGS Publications Warehouse

Nelson, C.H.; Johnson, K.R.; Barber, J.H.

1987-01-01

The gray whales (average mouth length, 2.0 m), when suction feeding on infaunal amphipods, create shallow pits in the sea floor, typically 2.5m x 1.5m x 10cm deep, which are distinct and mappable on sidescan sonographs. Similarly, walrus, when foraging for shallow clams, create long, linear feeding furrows that average 47 x 0.4 x 0.1m (length-width-depth). The whale feeding pits are commonly enlarged and oriented by seasonal storm-related scour. Walrus-feeding features are smaller, formed in higher-energy environments, and modified more rapidly than whale-feeding pits. -from Authors

Uptake and depuration of pharmaceuticals in aquatic invertebrates.

PubMed

Meredith-Williams, Melanie; Carter, Laura J; Fussell, Richard; Raffaelli, David; Ashauer, Roman; Boxall, Alistair B A

2012-06-01

The uptake and depuration of a range of pharmaceuticals in the freshwater shrimp (Gammarus pulex) and the water boatman (Notonecta glauca) was studied. For one compound, studies were also done using the freshwater snail Planobarius corneus. In G. pulex, bioconcentration factors (BCFs) ranged from 4.6 to 185,900 and increased in the order moclobemide < 5-fluoruracil < carbamazepine < diazepam < carvedilol < fluoxetine. In N. glauca BCFs ranged from 0.1 to 1.6 and increased in the order 5-fluorouracil < carbamazepine < moclobemide < diazepam < fluoxetine < carvedilol. For P. corneus, the BCF for carvedilol was 57.3. The differences in degree of uptake across the three organisms may be due to differences in mode of respiration, behaviour and the pH of the test system. BCFs of the pharmaceuticals for each organism were correlated to the pH-corrected liposome-water partition coefficient of the pharmaceuticals. Copyright © 2011 Elsevier Ltd. All rights reserved.

Biodiversity of suprabenthic peracarid assemblages from the Blanes Canyon region (NW Mediterranean Sea) in relation to natural disturbance and trawling pressure

NASA Astrophysics Data System (ADS)

Almeida, Mariana; Frutos, Inmaculada; Company, Joan B.; Martin, Daniel; Romano, Chiara; Cunha, Marina R.

2017-03-01

Blanes Canyon and its adjacent margin are important fishery areas (mainly by bottom trawling) located in a highly energetic oceanographic setting in the NW Mediterranean Sea. Here we assess the spatial and temporal variability in abundance, diversity and community structure of the suprabenthic peracarid assemblages in this region and examine this variability in relation to the natural and anthropogenic (trawling fisheries) disturbance regimes. The sampling was conducted between March 2003 and May 2004 in three main fishing grounds, the canyon head (average depth: 490 m), the canyon wall (average depth: 550 m) and the eastern adjacent slope (average depth: 820 m), as well as in two non-exploited areas in the western (at 900 m depth) and eastern (at 1500 m depth) slope near the canyon mouth. A total of 138 species were identified, with amphipods being the most speciose and abundant group, followed by mysids in terms of abundance. Our results show high spatial and temporal variability in suprabenthic assemblages. Densities were higher in the canyon head and western slope, which appear to be the preferential routes for water masses and particle fluxes in months of flood events, and other energetic processes. In the canyon head, where periodic erosion processes are more active, low diversity, high dominance and higher turnover (β-diversity) were observed, apparently coupled with significant temporal fluctuations in the densities of the highly motile component of suprabenthos (mysids, predatory and scavenging amphipods). In the sedimentary more stable eastern slope, high diversity values were observed, accompanied by a higher relative contribution of the less motile groups (i.e. amphipods, most isopods, cumaceans). These groups have a closer interaction with the sediment where they exploit different food sources and are more susceptible to physical disturbance. Temporal variability in their diversity may be related to changes in food quality rather than quantity. In the

The Ecology of Parasite-Host Interactions at Montezuma Well National Monument, Arizona - Appreciating the Importance of Parasites

USGS Publications Warehouse

O'Brien, Chris; van Riper, Charles

2009-01-01

Although parasites play important ecological roles through the direct interactions they have with their hosts, historically that fact has been underappreciated. Today, scientists have a growing appreciation of the scope of such impacts. Parasites have been reported to dominate food webs, alter predator-prey relationships, act as ecosystem engineers, and alter community structure. In spite of this growing awareness in the scientific community, parasites are still often neglected in the consideration of the management and conservation of resources and ecosystems. Given that at least half of the organisms on earth are probably parasitic, it should be evident that the ecological functions of parasites warrant greater attention. In this report, we explore different aspects of parasite-host relationships found at a desert spring pond within Montezuma Well National Monument, Arizona. In three separate but related chapters, we explore interactions between a novel amphipod host and two parasites. First, we identify how host behavior responds to this association and how this association affects interactions with both invertebrate non-host predators and a vertebrate host predator. Second, we look at the human dimension, investigating how human recreation can indirectly affect patterns of disease by altering patterns of vertebrate host space use. Finally - because parasites and diseases are of increasing importance in the management of wildlife species, especially those that are imperiled or of management concern - the third chapter argues that research would benefit from increased attention to the statistical analysis of wildlife disease studies. This report also explores issues of statistical parasitology, providing information that may better inform those designing research projects and analyzing data from studies of wildlife disease. In investigating the nature of parasite-host interactions, the role that relationships play in ecological communities, and how human

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 ...

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

NASA Astrophysics Data System (ADS)

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

2010-03-01

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

Analysis of the ecotoxicity data submitted within the framework of the REACH Regulation. Part 3. Experimental sediment toxicity assays.

PubMed

Cesnaitis, Romanas; Sobanska, Marta A; Versonnen, Bram; Sobanski, Tomasz; Bonnomet, Vincent; Tarazona, Jose V; De Coen, Wim

2014-03-15

For the first REACH registration deadline, companies have submitted registrations with relevant hazard and exposure information for substances at the highest tonnage level (above 1000 tonnes per year). At this tonnage level, information on the long-term toxicity of a substance to sediment organisms is required. There are a number of available test guidelines developed and accepted by various national/international organisations, which can be used to investigate long-term toxicity to sediment organisms. However instead of testing, registrants may also use other options to address toxicity to sediment organisms, e.g. weight of evidence approach, grouping of substances and read-across approaches, as well as substance-tailored exposure-driven testing. The current analysis of the data provided in ECHA database focuses on the test methods applied and the test organisms used in the experimental studies to assess long-term toxicity to sediment organisms. The main guidelines used for the testing of substances registered under REACH are the OECD guidelines and OSPAR Protocols on Methods for the Testing of Chemicals used in the Offshore Oil Industry: "Part A: A Sediment Bioassay using an Amphipod Corophium sp." explaining why one of the mostly used test organisms is the marine amphipod Corophium sp. In total, testing results with at least 40 species from seven phyla are provided in the database. However, it can be concluded that the ECHA database does not contain a high enough number of available experimental data on toxicity to sediment organisms for it to be used extensively by the scientific community (e.g. for development of non-testing methods to predict hazards to sediment organisms). © 2013.

Comparative analysis of feeding ecology of capelin from two shelf ecosystems, off Newfoundland and in the Barents Sea

NASA Astrophysics Data System (ADS)

Dalpadado, Padmini; Mowbray, Fran

2013-07-01

Four years of capelin (Mallotus villosus) diet data were examined from each of two ecosystems where capelin are an important forage species, the NW Atlantic off Newfoundland and the Barents Sea. Trophic studies from the two areas showed that, the Total Fullness Index (TFI), which reflects the diet weight, was significantly lower in capelin off Newfoundland compared to the Barents Sea, suggestive of poorer feeding conditions for Newfoundland capelin during the study period. In both regions, the copepod, Calanus finmarchicus dominated the diet of smaller capelin (<12 cm) comprising over half of their stomach content. However, there was a major difference in the diet of larger capelin. In the Barents Sea, a pronounced shift in the diet from copepods to krill, mostly Thysanoessa inermis, was observed in larger capelin (>12 cm), with krill being the largest contributor to the diet weight. In contrast, off Newfoundland, copepods remained the most important prey in larger capelin. In both ecosystems arctic amphipods, mostly dominated by Themisto libellula, contributed a small amount to the diet of larger capelin but were nearly absent in the diet of smaller fish. Findings for Newfoundland waters contradict past studies where krill (T. raschii) seems to have been a major component in the diet, especially for mature capelin. In both systems diurnal patterns in TFI indicated that daytime feeding was more successful. In general, a short efficient food chain (phytoplankton via Calanus or herbivorous krill to capelin) was observed in both regions. The extent of consumption of carnivorous zooplankton such as hyperiid amphipods may lengthen the trophic levels and thus reduce efficiency of energy transfer.

Benthic herbivores are not deterred by brevetoxins produced by the red tide dinoflagellate Karenia brevis.

PubMed

Sotka, Erik E; McCarty, Amanda; Monroe, Emily A; Oakman, Nicole; Van Dolah, Frances M

2009-07-01

Gulf of Mexico blooms of the dinoflagellate Karenia brevis produce neurotoxic cyclic polyethers called brevetoxins. During and after a red tide bloom in southwestern Florida, K. brevis cells lyse and release brevetoxins, which then sink to the benthos and coat the surfaces of seagrasses and their epiphytes. We tested the possibility that these brevetoxin-laden foods alter the feeding behavior and fitness of a common benthic herbivore within Floridean seagrass beds, the amphipod Ampithoe longimana. We demonstrated that coating foods with K. brevis extracts that contain brevetoxins at post-bloom concentrations (1 microg g(-1) drymass) does not alter the feeding rates of Florida nor North Carolina populations of A. longimana, although a slight deterrent effect was found at eight and ten-fold greater concentrations. During a series of feeding choice assays, A. longimana tended not to be deterred by foods coated with K. brevis extracts nor with the purified brevetoxins PbTx-2 and PbTx-3. Florida juveniles isolated with either extract-coated or control foods for 10 days did not differ in survivorship nor growth. A similar lack of feeding response to brevetoxin-laden foods also was exhibited by two other generalist herbivores of the southeastern United States, the amphipod A. valida and the urchin Arbacia punctulata. Given that benthic mesograzers constitute a significant portion of the diet for the juvenile stage of many nearshore fishes, we hypothesize that the ability of some mesograzers to feed on and retain brevetoxins in their bodies indicates that mesograzers may represent an important route of vertical transmission of brevetoxins through higher trophic levels within Gulf of Mexico estuaries.

The biological effects of antidepressants on the molluscs and crustaceans: a review.

PubMed

Fong, Peter P; Ford, Alex T

2014-06-01

Antidepressants are among the most commonly detected human pharmaceuticals in the aquatic environment. Since their mode of action is by modulating the neurotransmitters serotonin, dopamine, and norepinephrine, aquatic invertebrates who possess transporters and receptors sensitive to activation by these pharmaceuticals are potentially affected by them. We review the various types of antidepressants, their occurrence and concentrations in aquatic environments, and the actions of neurohormones modulated by antidepressants in molluscs and crustaceans. Recent studies on the effects of antidepressants on these two important groups show that molluscan reproductive and locomotory systems are affected by antidepressants at environmentally relevant concentrations. In particular, antidepressants affect spawning and larval release in bivalves and disrupt locomotion and reduce fecundity in snails. In crustaceans, antidepressants affect freshwater amphipod activity patterns, marine amphipod photo- and geotactic behavior, crayfish aggression, and daphnid reproduction and development. We note with interest the occurrence of non-monotonic dose responses curves in many studies on effects of antidepressants on aquatic animals, often with effects at low concentrations, but not at higher concentrations, and we suggest future experiments consider testing a broader range of concentrations. Furthermore, we consider invertebrate immune responses, genomic and transcriptomic sequencing of invertebrate genes, and the ever-present and overwhelming question of how contaminant mixtures could affect the action of neurohormones as topics for future study. In addressing the question, if antidepressants affect aquatic invertebrates at concentrations currently found in the environment, there is strong evidence to suggest the answer is yes. Furthermore, the examples highlighted in this review provide compelling evidence that the effects could be quite multifaceted across a variety of biological

Under the volcano: phylogeography and evolution of the cave-dwelling Palmorchestia hypogaea (Amphipoda, Crustacea) at La Palma (Canary Islands)

PubMed Central

Villacorta, Carlos; Jaume, Damià; Oromí, Pedro; Juan, Carlos

2008-01-01

Background The amphipod crustacean Palmorchestia hypogaea occurs only in La Palma (Canary Islands) and is one of the few terrestrial amphipods in the world that have adapted to a strictly troglobitic life in volcanic cave habitats. A surface-dwelling closely related species (Palmorchestia epigaea) lives in the humid laurel forest on the same island. Previous studies have suggested that an ancestral littoral Orchestia species colonized the humid forests of La Palma and that subsequent drought episodes in the Canaries reduced the distribution of P. epigaea favouring the colonization of lava tubes through an adaptive shift. This was followed by dispersal via the hypogean crevicular system. Results P. hypogaea and P. epigaea did not form reciprocally monophyletic mitochondrial DNA clades. They showed geographically highly structured and genetically divergent populations with current gene flow limited to geographically close surface locations. Coalescence times using Bayesian estimations assuming a non-correlated relaxed clock with a normal prior distribution of the age of La Palma, together with the lack of association of habitat type with ancestral and recent haplotypes, suggest that their adaptation to cave life is relatively ancient. Conclusion The data gathered here provide evidence for multiple invasions of the volcanic cave systems that have acted as refuges. A re-evaluation of the taxonomic status of the extant species of Palmorchestia is needed, as the division of the two species by habitat and ecology is unnatural. The information obtained here, and that from previous studies on hypogean fauna, shows the importance of factors such as the uncoupling of morphological and genetic evolution, the role of climatic change and regressive evolution as key processes in leading to subterranean biodiversity. PMID:18234125

Importance of equilibration time in the partitioning and toxicity of zinc in spiked sediment bioassays

USGS Publications Warehouse

Lee, J.-S.; Lee, B.-G.; Luoma, S.N.; Yoo, H.

2004-01-01

The influences of spiked Zn concentrations (1-40 ??mol/g) and equilibration time (???95 d) on the partitioning of Zn between pore water (PW) and sediment were evaluated with estuarine sediments containing two levels (5 and 15 ??mol/g) of acid volatile sulfides (AVS). Their influence on Zn bioavailability was also evaluated by a parallel, 10-d amphipod (Leptocheirus plumulosus) mortality test at 5, 20, and 85 d of equilibration. During the equilibration, AVS increased (up to twofold) with spiked Zn concentration ([Zn]), whereas Zn-simultaneously extracted metals ([SEM]; Zn with AVS) remained relatively constant. Concentrations of Zn in PW decreased most rapidly during the initial 30 d and by 11- to 23-fold during the whole 95-d equilibration period. The apparent partitioning coefficient (Kpw, ratio of [Zn] in SEM to PW) increased by 10- to 20-fold with time and decreased with spiked [Zn] in sediments. The decrease of PW [Zn] could be explained by a combination of changes in AVS and redistribution of Zn into more insoluble phases as the sediment aged. Amphipod mortality decreased significantly with the equilibration time, consistent with decrease in dissolved [Zn]. The median lethal concentration (LC50) value (33 ??M) in the second bioassay, conducted after 20 d of equilibration, was twofold the LC50 in the initial bioassay at 5 d of equilibration, probably because of the change of dissolved Zn speciation. Sediment bioassay protocols employing a short equilibration time and high spiked metal concentrations could accentuate partitioning of metals to the dissolved phase and shift the pathway for metal exposure toward the dissolved phase.

Under the volcano: phylogeography and evolution of the cave-dwelling Palmorchestia hypogaea (Amphipoda, Crustacea) at La Palma (Canary Islands).

PubMed

Villacorta, Carlos; Jaume, Damià; Oromí, Pedro; Juan, Carlos

2008-01-31

The amphipod crustacean Palmorchestia hypogaea occurs only in La Palma (Canary Islands) and is one of the few terrestrial amphipods in the world that have adapted to a strictly troglobitic life in volcanic cave habitats. A surface-dwelling closely related species (Palmorchestia epigaea) lives in the humid laurel forest on the same island. Previous studies have suggested that an ancestral littoral Orchestia species colonized the humid forests of La Palma and that subsequent drought episodes in the Canaries reduced the distribution of P. epigaea favouring the colonization of lava tubes through an adaptive shift. This was followed by dispersal via the hypogean crevicular system. P. hypogaea and P. epigaea did not form reciprocally monophyletic mitochondrial DNA clades. They showed geographically highly structured and genetically divergent populations with current gene flow limited to geographically close surface locations. Coalescence times using Bayesian estimations assuming a non-correlated relaxed clock with a normal prior distribution of the age of La Palma, together with the lack of association of habitat type with ancestral and recent haplotypes, suggest that their adaptation to cave life is relatively ancient. The data gathered here provide evidence for multiple invasions of the volcanic cave systems that have acted as refuges. A re-evaluation of the taxonomic status of the extant species of Palmorchestia is needed, as the division of the two species by habitat and ecology is unnatural. The information obtained here, and that from previous studies on hypogean fauna, shows the importance of factors such as the uncoupling of morphological and genetic evolution, the role of climatic change and regressive evolution as key processes in leading to subterranean biodiversity.

The trophic position of the alien crab Rhithropanopeus harrisii (crustacea decapoda panopeidae) in the Taman Bay, Sea of Azov community

NASA Astrophysics Data System (ADS)

Zalota, A. K.; Kolyuchkina, G. A.; Tiunov, A. V.; Biriukova, S. V.; Spiridonov, V. A.

2017-03-01

This work concerns the trophic web positioning of the alien crab Rhithropanopeus harrisii and other common marine invertebrate species and fishes in the benthic ecosystem of the shallows of Taman Bay, Sea of Azov. The base of the trophic web in this system is composed of phytoplankton, macrophytes (algae and marine grasses), and reeds that use atmospheric carbon for photosynthesis. Analysis of the isotopic composition of nitrogen and carbon has shown that although marine grasses are dominating primary producers in the shallows of the bay, primary consumers (such as Cerastoderma glaucum, Porifera gen. sp., Gammarus aequicauda, Deshayesorchestia deshayesii and Idotea balthica) only partially use this organic source; instead, they use a combination of different sources of primary production. It has been shown that the food source of the alien crab is primarily of animal origin. In Taman Bay, R. harrisii is on the same trophic level as other carnivores/scavengers: benthic fishes Syngnathus nigrolineatus, Gobius spp. and native crab Pilumnus hirtellus and shrimp Palaemon adspersus.

Seagrass habitat complexity and macroinvertebrate abundance in Lakshadweep coral reef lagoons, Arabian Sea

NASA Astrophysics Data System (ADS)

Ansari, Z. A.; Rivonker, C. U.; Ramani, P.; Parulekar, A. H.

1991-09-01

Macrofauna of seagrass community in the five Lakshadweep atolls were studied and compared. The associated epifaunal and infaunal taxa comprising nine major taxonomic groups, showed significant differences in the total number of individuals (1041 8411 m-2) among sites and habitats. The density of macrofauna was directly related to mean macrophytic biomass (405 895 g wet wt. m-2). The fauna was dominated by epifaunal polychaetes, amphipods and isopods in the vegetated areas. When compared with the density of nearby unvegetated areasleft( {bar x = 815{text{m }}^{ - 2} } right), seagrass meadows harbour a denser and richer macroinvertebrate assemblageleft( {bar x = 4023{text{m }}^{ - 2} } right).

Genetic characterization of Toxoplasma gondii from Brazilian wildlife revealed abundant new genotypes.

PubMed

Vitaliano, S N; Soares, H S; Minervino, A H H; Santos, A L Q; Werther, K; Marvulo, M F V; Siqueira, D B; Pena, H F J; Soares, R M; Su, C; Gennari, S M

2014-12-01

This study aimed to isolate and genotype T. gondii from Brazilian wildlife. For this purpose, 226 samples were submitted to mice bioassay and screened by PCR based on 18S rRNA sequences. A total of 15 T. gondii isolates were obtained, including samples from four armadillos (three Dasypus novemcinctus, one Euphractus sexcinctus), three collared anteaters (Tamandua tetradactyla), three whited-lipped peccaries (Tayassu pecari), one spotted paca (Cuniculus paca), one oncilla (Leopardus tigrinus), one hoary fox (Pseudalopex vetulus), one lineated woodpecker (Dryocopus lineatus) and one maned wolf (Chrysocyon brachyurus). DNA from the isolates, originated from mice bioassay, and from the tissues of the wild animal, designated as "primary samples", were genotyped by PCR-restriction fragment length polymorphism (PCR/RFLP), using 12 genetic markers (SAG1, SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L258, PK1, CS3 and Apico). A total of 17 genotypes were identified, with 13 identified for the first time and four already reported in published literature. Results herein obtained corroborate previous studies in Brazil, confirming high diversity and revealing unique genotypes in this region. Given most of genotypes here identified are different from previous studies in domestic animals, future studies on T. gondii from wildlife is of interest to understand population genetics and structure of this parasite.

Genetic characterization of Toxoplasma gondii from Brazilian wildlife revealed abundant new genotypes

PubMed Central

Vitaliano, S.N.; Soares, H.S.; Minervino, A.H.H.; Santos, A.L.Q.; Werther, K.; Marvulo, M.F.V.; Siqueira, D.B.; Pena, H.F.J.; Soares, R.M.; Su, C.; Gennari, S.M.

2014-01-01

This study aimed to isolate and genotype T. gondii from Brazilian wildlife. For this purpose, 226 samples were submitted to mice bioassay and screened by PCR based on 18S rRNA sequences. A total of 15 T. gondii isolates were obtained, including samples from four armadillos (three Dasypus novemcinctus, one Euphractus sexcinctus), three collared anteaters (Tamandua tetradactyla), three whited-lipped peccaries (Tayassu pecari), one spotted paca (Cuniculus paca), one oncilla (Leopardus tigrinus), one hoary fox (Pseudalopex vetulus), one lineated woodpecker (Dryocopus lineatus) and one maned wolf (Chrysocyon brachyurus). DNA from the isolates, originated from mice bioassay, and from the tissues of the wild animal, designated as “primary samples”, were genotyped by PCR–restriction fragment length polymorphism (PCR/RFLP), using 12 genetic markers (SAG1, SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L258, PK1, CS3 and Apico). A total of 17 genotypes were identified, with 13 identified for the first time and four already reported in published literature. Results herein obtained corroborate previous studies in Brazil, confirming high diversity and revealing unique genotypes in this region. Given most of genotypes here identified are different from previous studies in domestic animals, future studies on T. gondii from wildlife is of interest to understand population genetics and structure of this parasite. PMID:25426424

Isolation of laccase gene-specific sequences from white rot and brown rot fungi by PCR.

PubMed Central

D'Souza, T M; Boominathan, K; Reddy, C A

1996-01-01

Degenerate primers corresponding to the consensus sequences of the copper-binding regions in the N-terminal domains of known basidiomycete laccases were used to isolate laccase gene-specific sequences from strains representing nine genera of wood rot fungi. All except three gave the expected PCR product of about 200 bp. Computer searches of the databases identified the sequence of each of the PCR products analyzed as a laccase gene sequence, suggesting the specificity of the primers. PCR products of the white rot fungi Ganoderma lucidum, Phlebia brevispora, and Trametes versicolor showed 65 to 74% nucleotide sequence similarity to each other; the similarity in deduced amino acid sequences was 83 to 91%. The PCR products of Lentinula edodes and Lentinus tigrinus, on the other hand, showed relatively low nucleotide and amino acid similarities (58 to 64 and 62 to 81%, respectively); however, these similarities were still much higher than when compared with the corresponding regions in the laccases of the ascomycete fungi Aspergillus nidulans and Neurospora crassa. A few of the white rot fungi, as well as Gloeophyllum trabeum, a brown rot fungus, gave a 144-bp PCR fragment which had a nucleotide sequence similarity of 60 to 71%. Demonstration of laccase activity in G. trabeum and several other brown rot fungi was of particular interest because these organisms were not previously shown to produce laccases. PMID:8837429

Laboratory toxicity and benthic invertebrate field colonization of Upper Columbia River sediments: finding adverse effects using multiple lines of evidence.

PubMed

Fairchild, J F; Kemble, N E; Allert, A L; Brumbaugh, W G; Ingersoll, C G; Dowling, B; Gruenenfelder, C; Roland, J L

2012-07-01

From 1930 to 1995, the Upper Columbia River (UCR) of northeast Washington State received approximately 12 million metric tons of smelter slag and associated effluents from a large smelter facility located in Trail, British Columbia, approximately 10 km north of the United States-Canadian border. Studies conducted during the past two decades have demonstrated the presence of toxic concentrations of heavy metals in slag-based sandy sediments, including cadmium, copper, zinc, and lead in the UCR area as well as the downstream reservoir portion of Lake Roosevelt. We conducted standardized whole-sediment toxicity tests with the amphipod Hyalella azteca (28-day) and the midge Chironomus dilutus (10-day) on 11 samples, including both UCR and study-specific reference sediments. Metal concentrations in sediments were modeled for potential toxicity using three approaches: (1) probable effects quotients (PEQs) based on total recoverable metals (TRMs) and simultaneously extracted metals (SEMs); (2) SEMs corrected for acid-volatile sulfides (AVS; i.e., ∑SEM - AVS); and (3) ∑SEM - AVS normalized to the fractional organic carbon (f(oc)) (i.e., ∑SEM - AVS/f(oc)). The most highly metal-contaminated sample (∑PEQ(TRM) = 132; ∑PEQ(SEM) = 54; ∑SEM - AVS = 323; and ∑SEM - AVS/(foc) = 64,600 umol/g) from the UCR was dominated by weathered slag sediment particles and resulted in 80% mortality and 94% decrease in biomass of amphipods; in addition, this sample significantly decreased growth of midge by 10%. The traditional ∑AVS - SEM, uncorrected for organic carbon, was the most accurate approach for estimating the effects of metals in the UCR. Treatment of the toxic slag sediment with 20% Resinex SIR-300 metal-chelating resin significantly decreased the toxicity of the sample. Samples ∑SEM - AVS > 244 was not toxic to amphipods or midge in laboratory testing, indicating that this value may be an approximate threshold for effects in the UCR. In situ benthic invertebrate

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...

Retention of ice-associated amphipods: possible consequences for an ice-free Arctic Ocean.

PubMed

Berge, J; Varpe, O; Moline, M A; Wold, A; Renaud, P E; Daase, M; Falk-Petersen, S

2012-12-23

Recent studies predict that the Arctic Ocean will have ice-free summers within the next 30 years. This poses a significant challenge for the marine organisms associated with the Arctic sea ice, such as marine mammals and, not least, the ice-associated crustaceans generally considered to spend their entire life on the underside of the Arctic sea ice. Based upon unique samples collected within the Arctic Ocean during the polar night, we provide a new conceptual understanding of an intimate connection between these under-ice crustaceans and the deep Arctic Ocean currents. We suggest that downwards vertical migrations, followed by polewards transport in deep ocean currents, are an adaptive trait of ice fauna that both increases survival during ice-free periods of the year and enables re-colonization of sea ice when they ascend within the Arctic Ocean. From an evolutionary perspective, this may have been an adaptation allowing success in a seasonally ice-covered Arctic. Our findings may ultimately change the perception of ice fauna as a biota imminently threatened by the predicted disappearance of perennial sea ice.

Population Dynamics and Production of the Amphipod Corophium salmonis in Grays Harbor, Washington,

DTIC Science & Technology

1981-09-01

biomass ratios of bivalve and gastropod population in an eastern Canadian estuary. J. Fish. Res. Bd. Can. 31: 167-177. Casablanca, M. -L., de. 1975...analysis was adapted from "Standards Methods for the Examination of Water and Wastewater," 14th Edition, APHA, AWWA, and WPCF, Washington, D.C., 1975, pp

Comparison in waterborne Cu, Ni and Pb bioaccumulation kinetics between different gammarid species and populations: Natural variability and influence of metal exposure history.

PubMed

Urien, N; Farfarana, A; Uher, E; Fechner, L C; Chaumot, A; Geffard, O; Lebrun, J D

2017-12-01

Kinetic parameters (uptake from solution and elimination rate constants) of Cu, Ni and Pb bioaccumulation were determined from two Gammarus pulex and three Gammarus fossrum wild populations collected from reference sites throughout France in order to assess the inter-species and the natural inter-population variability of metal bioaccumulation kinetics in that sentinel organism. For that, each population was independently exposed for seven days to either 2.5μgL -1 Cu (39.3nM), 40μgL -1 Ni (681nM) or 10μgL -1 Pb (48.3nM) in laboratory controlled conditions, and then placed in unexposed microcosms for a 7-day depuration period. In the same way, the possible influence of metal exposure history on subsequent metal bioaccumulation kinetics was addressed by collecting wild gammarids from three populations inhabiting stations contaminated either by Cd, Pb or both Pb and Ni (named pre-exposed thereafter). In these pre-exposed organisms, assessment of any changes in metal bioaccumulation kinetics was achieved by comparison with the natural variability of kinetic parameters defined from reference populations. Results showed that in all studied populations (reference and pre-exposed) no significant Cu bioaccumulation was observed at the exposure concentration of 2.5μgL -1 . Concerning the reference populations, no significant differences in Ni and Pb bioaccumulation kinetics between the two species (G. pulex and G. fossarum) was observed allowing us to consider all the five reference populations to determine the inter-population natural variability, which was found to be relatively low (kinetic parameters determined for each population remained within a factor of 2 of the minimum and maximum values). Organisms from the population exhibiting a Pb exposure history presented reduced Ni uptake and elimination rate constants, whereas no influence on Ni kinetic parameters was observed in organisms from the population exhibiting an exposure history to both Ni and Pb. Furthermore

Changes in the deep-water benthos of eastern Lake Erie between 1979 and 1993

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

Dermott, R.; Kerec, D.

1995-06-01

In order to examine changes of the benthic community and benthic biomass as a result of mussel colonization, a survey of the deep-water benthic fauna in eastern Lake Erie was repeated in 1993 using the same sites and methods as in a 1979 survey. During 1979, the community beyond 30 m was dominated by oligochaete worms and the burrowing amphipod Diporeia, which represented 50 and 40% of the total benthic biomass respectively. By 1993, quagga mussels (Dreissena bugensis) formed over 90% of the benthic biomass. Mussels were present at all 13 sites. Densities of individuals >2 mm in length averagedmore » 3,241 mussels m{sup -2}. Of these mussels, 97% were quagga mussels. Total density of all sizes retained on a 180 {mu}m sieve averaged 34,800 mussels m{sup -2} but total biomass decreased from 1.58 to 0.98 g m{sup -2}. The density of the amphipod Diporeia was reduced from 1,844 in 1979 to 218 m{sup -2} in 1993. While present at all sites during 1979, Diporeia remained common only at two sites and were absent at 8 of the 13 sites in 1993. The native fingernail clams, Pisidium spp., were reduced from 327 to 82 m{sup -2}. No significant reduction occurred in the worm and chironomid populations, however the dry biomass of the chironomids was reduced from 0.07 to 0.0008 g m{sup -2}. These reductions may be due to competition with the mussels for freshly settling algae. The meiofauna, which included small nematodes, ostracods, and harpacticoids retained on a 180 {mu}m sieve, all increased in density. Perhaps they benefited from an increase in the detritus deposited as pseudofeces around the mussels.« less

Influence of pH on the acute toxicity of ammonia to juvenile freshwater mussels (fatmucket, Lampsills siliquoidea)

USGS Publications Warehouse

Wang, N.; Erickson, R.J.; Ingersoll, C.G.; Ivey, C.D.; Brunson, E.L.; Augspurger, T.; Barnhart, M.C.

2008-01-01

The objective of the present study was to evaluate the influence of pH on the toxicity of ammonia to juvenile freshwater mussels. Acute 96-h ammonia toxicity tests were conducted with 10-d-old juvenile mussels (fatmucket, Lampsilis siliquoidea) at five pH levels ranging from 6.5 to 9.0 in flow-through diluter systems at 20??C. Acute 48-h tests with amphipods (Hyalella azteca) and 96-h tests with oligochaetes (Lumbriculus variegatus) were conducted concurrently under the same test conditions to determine the sensitivity of mussels relative to these two commonly tested benthic invertebrate species. During the exposure, pH levels were maintained within 0.1 of a pH unit and ammonia concentrations were relatively constant through time (coefficient of variation for ammonia concentrations ranged from 2 to 30% with a median value of 7.9%). The median effective concentrations (EC50s) of total ammonia nitrogen (N) for mussels were at least two to six times lower than the EC50s for amphipods and oligochaetes, and the EC50s for mussels decreased with increasing pH and ranged from 88 mg N/L at pH 6.6 to 0.96 mg N/L at pH 9.0. The EC50s for mussels were at or below the final acute values used to derive the U.S. Environmental Protection Agency's acute water quality criterion (WQC). However, the quantitative relationship between pH and ammonia toxicity to juvenile mussels was similar to the average relationship for other taxa reported in the WQC. These results indicate that including mussel toxicity data in a revision to the WQC would lower the acute criterion but not change the WQC mathematical representation of the relative effect of pH on ammonia toxicity. ?? 2008 SETAC.

Influence of changing plant food sources on the gut microbiota of saltmarsh detritivores.

PubMed

Dittmer, Jessica; Lesobre, Jérôme; Raimond, Roland; Zimmer, Martin; Bouchon, Didier

2012-10-01

Changes in agricultural land-use of saltmarshes along the German North Sea coast have favoured the succession of the marsh grass Elytrigia atherica over the long-established Spartina anglica. Consequently, E. atherica represents a potential food source of increasing importance for plant-feeding soil detritivores. Considering the importance of this ecological guild for decomposition processes and nutrient cycling, we focussed on two sympatric saltmarsh soil macrodetritivores and their associated gut microbiota to investigate how the digestive processes of these species may be affected by changing plant food sources. Using genetic fingerprints of partial 16S rRNA gene sequences, we analysed composition and diversity of the bacterial gut community in a diplopod and an amphipod crustacean in relation to different feeding regimes representing the natural vegetation changes. Effects of syntopy on the host-specific gut microbiota were also taken into account by feeding the two detritivore species either independently or on the same plant sample. Bacterial community composition was influenced by both the host species and the available plant food sources, but the latter had a stronger effect on microbial community structure. Furthermore, bacterial diversity was highest after feeding on a mixture of both plant species, regardless of the host species. The gut microbiota of these two detritivores can thus be expected to change along with the on-going succession at the plant community level in this environment. Cloning and sequencing of bacterial 16S rRNA gene fragments further indicated a host-related effect since the two detritivores differed in terms of predominant bacterial taxa: diplopods harboured mainly representatives of the phyla Bacteroidetes and Gammaproteobacteria. In contrast, the genus Vibrio was found for the amphipod host across all feeding conditions.

Evaluation of dredged material proposed for ocean disposal from Hackensack River Project Area, New York

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

Gruendell, B.D.; Barrows, E.S.; Borde, A.B.

1997-01-01

The objective of the bioassay reevaluation of the Hackensack River Federal Project was to reperform toxicity testing on proposed dredged material with current ammonia reduction protocols. Hackensack River was one of four waterways sampled and evaluated for dredging and disposal in April 1993. Sediment samples were re-collected from the Hackensack River Project area in August 1995. Tests and analyses were conducted according to the manual developed by the USACE and the U.S. Environmental Protection Agency (EPA), Evaluation of Dredged Material Proposed for Ocean Disposal (Testing Manual), commonly referred to as the {open_quotes}Green Book,{close_quotes} and the regional manual developed by themore » USACE-NYD and EPA Region II, Guidance for Performing Tests on Dredged Material to be Disposed of in Ocean Waters. The reevaluation of proposed dredged material from the Hackensack River project area consisted of benthic acute toxicity tests. Thirty-three individual sediment core samples were collected from the Hackensack River project area. Three composite sediments, representing each reach of the area proposed for dredging, were used in benthic acute toxicity testing. Benthic acute toxicity tests were performed with the amphipod Ampelisca abdita and the mysid Mysidopsis bahia. The amphipod and mysid benthic toxicity test procedures followed EPA guidance for reduction of total ammonia concentrations in test systems prior to test initiation. Statistically significant acute toxicity was found in all three Hackensack River composites in the static renewal tests with A. abdita, but not in the static tests with M. bahia. Statistically significant acute toxicity and a greater than 20% increase in mortality over the reference sediment was found in the static renewal tests with A. abdita. Statistically significant mortality 10% over reference sediment was observed in the M. bahia static tests. 5 refs., 2 figs., 2 tabs.« less

Evaluation of dredged material proposed for ocean disposal from Arthur Kill Project Area, New York

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

Gruendell, B.D.; Barrows, E.S.; Borde, A.B.

1997-01-01

The objective of the bioassay reevaluation of Arthur Kill Federal Project was to reperform toxicity testing on proposed dredged material following current ammonia reduction protocols. Arthur Kill was one of four waterways sampled and evaluated for dredging and disposal in April 1993. Sediment samples were recollected from the Arthur Kill Project areas in August 1995. Tests and analyses were conducted according to the manual developed by the USACE and the U.S. Environmental Protection Agency (EPA), Evaluation of Dredged Material Proposed for Ocean Disposal (Testing Manual), commonly referred to as the {open_quotes}Green Book,{close_quotes} and the regional manual developed by the USACE-NYDmore » and EPA Region II, Guidance for Performing Tests on Dredged Material to be Disposed of in Ocean Waters. The reevaluation of proposed dredged material from the Arthur Kill project areas consisted of benthic acute toxicity tests. Thirty-three individual sediment core samples were collected from the Arthur Kill project area. Three composite sediments, representing each reach of the area proposed for dredging, was used in benthic acute toxicity testing. Benthic acute toxicity tests were performed with the amphipod Ampelisca abdita and the mysid Mysidopsis bahia. The amphipod and mysid benthic toxicity test procedures followed EPA guidance for reduction of total ammonia concentrations in test systems prior to test initiation. Statistically significant acute toxicity was found in all Arthur Kill composites in the static renewal tests with A. abdita, but not in the static tests with M. bahia. Statistically significant acute toxicity and a greater than 20% increase in mortality over the reference sediment was found in the static renewal tests with A. abdita. M. bahia did not show statistically significant acute toxicity or a greater than 10% increase in mortality over reference sediment in static tests. 5 refs., 2 figs., 2 tabs.« less

Climate change, parasitism and the structure of intertidal ecosystems.

PubMed

Poulin, R; Mouritsen, K N

2006-06-01

Evidence is accumulating rapidly showing that temperature and other climatic variables are driving many ecological processes. At the same time, recent research has highlighted the role of parasitism in the dynamics of animal populations and the structure of animal communities. Here, the likely interactions between climate change and parasitism are discussed in the context of intertidal ecosystems. Firstly, using the soft-sediment intertidal communities of Otago Harbour, New Zealand, as a case study, parasites are shown to be ubiquitous components of intertidal communities, found in practically all major animal species in the system. With the help of specific examples from Otago Harbour, it is demonstrated that parasites can regulate host population density, influence the diversity of the entire benthic community, and affect the structure of the intertidal food web. Secondly, we document the extreme sensitivity of cercarial production in parasitic trematodes to increases in temperature, and discuss how global warming could lead to enhanced trematode infections. Thirdly, the results of a simulation model are used to argue that parasite-mediated local extinctions of intertidal animals are a likely outcome of global warming. Specifically, the model predicts that following a temperature increase of less than 4 degrees C, populations of the amphipod Corophium volutator, a hugely abundant tube-building amphipod on the mudflats of the Danish Wadden Sea, are likely to crash repeatedly due to mortality induced by microphallid trematodes. The available evidence indicates that climate-mediated changes in local parasite abundance will have significant repercussions for intertidal ecosystems. On the bright side, the marked effects of even slight increases in temperature on cercarial production in trematodes could form the basis for monitoring programmes, with these sensitive parasites providing early warning signals of the environmental impacts of global warming.

Relative contribution of lipid sources to eggs of lesser scaup

USGS Publications Warehouse

Cutting, Kyle A.; Hobson, Keith A.; Rotella, Jay J.; Warren, Jeffrey M.; Takekawa, John Y.; De La Cruz, Susan E. W.; Parker, Michael

2014-01-01

Studies of how birds mobilize nutrients to eggs have traditionally considered a continuum of possible allocation strategies ranging from income breeding (rely on food sources found on the breeding grounds) to capital breeding (rely on body reserves stored prior to the breeding season). For capital breeding, stored body reserves can be acquired either on or away from the breeding grounds, but it has been difficult to quantify the relative contribution of each, precluding identification of key habitats for acquiring nutrients for clutch formation. During 2006–2009, we explored the importance of spring-staging habitats versus breeding-area habitats for egg-lipid formation in female lesser scaup Aythya affinis using stable carbon (δ13C) isotope analyses. Although δ13C values for abdominal lipid reserves brought to the breeding grounds overlapped those of local amphipods, we were able to quantify the importance of local plant carbohydrates (seeds of emergent wetland plants) to the production of eggs. We compared the importance of local wetland seeds (overall δ13C: −29.1 ± 0.9‰ SD) to combined lipid stores and lipids from local amphipods (overall δ13C: −23.8 ± 2.2‰). Local seeds and stored body lipids contributed equally to egg lipid formation across years but we found evidence of annual variation in their relative importance. Wetland seeds contributed 39% (SE = 10%) to egg lipid production, and the importance of this source varied by year (90% CI = 47–75% in 2006, 13–42% in 2007, 29–65% in 2008, and 7–30% in 2009). In contrast to earlier studies that suggest lesser scaup predominantly employ a capital breeding strategy, our results suggest that in some years females may attain half of their energy for clutch formation from foods on the breeding grounds.

Biodiversity, Community and Trophic Structure of the Suprabenthos of the Gulf of Cádiz-Guadalquivir Estuary Coupled System: Linking Pelagic-Benthic and Terrestrial-Marine Ecosystems.

NASA Astrophysics Data System (ADS)

Vilas, C.

2016-02-01

Suprabenthos biodiversity and species densities on both offshore and coastal systems are largely unknown. Main components like mysids, euphasiids or amphipods are omnivorous and constitute a major dietary component for many benthic and pelagic fishes, mammals, cephalopods and decapods. Despite their relevant ecological role linking pelagic-benthic food webs, suprabenthos have been chronically undersampled and their components underrepresented and underestimated in food web models. Many pelagic and demersal species of high commercial and ecological interest at the Gulf of Cádiz (GoC) feed at a bottom scattering layer identified from 0 to 200 m depth and up to 50 km from coast, related to the Guadalquivir Estuary (GE) influence coastal area, and present life history cycles based on a sequential use of habitats from GoC to GE nursery area, may be adapted to match the horizontal migrations of key suprabenthos prey species. In order to understand the ecological mechanisms through which the GE-GoC coupled ecosystem would influence the recruitment of these fishery resources, the suprabenthos was sampled by suprabenthic sldege (200 μm) from the shallow estuary to 75 m depth during June, August and November of 2013. We identified up to 300 species (H index 0.4-2-9 and Beta diversity 0.55), being copepods, molluscs, cumacea, cladocera, poliquets, decapods, mysids and amphipods the most important groups by biomass (mg/m3), finding densities up to 32.9 mg/m3 for copepods, 6 for mysids and up to 100 mg/m3 for decapods. Multivariate analysis determines depth as the most important variable explaining community structure, decreasing biodiversity with depth, while for sites at depths < 30 m the community changes seasonal. Fatty acid analysis of different group sizes is revealing interesting trophic links. Some prey copepods and mysid species show seasonal horizontal migrations between GoC and GE, connecting terrestrial and marine ecosystems.

Ecotoxicologic impacts of agricultural drain water in the Salinas River, California, USA.

PubMed

Anderson, Brian S; Hunt, John W; Phillips, Bryn M; Nicely, Patricia A; Gilbert, Kristine D; de Vlaming, Victor; Connor, Valerie; Richard, Nancy; Tjeerdema, Ronald S

2003-10-01

The Salinas River is the largest of the three rivers that drain into the Monterey Bay National Marine Sanctuary in central California (USA). Large areas of this watershed are cultivated year-round in row crops, and previous laboratory studies have demonstrated that acute toxicity of agricultural drain water to Ceriodaphnia dubia is caused by the organophosphate (OP) pesticides chlorpyrifos and diazinon. We investigated chemical contamination and toxicity in waters and sediments in the river downstream of an agricultural drain water input. Ecological impacts of drain water were investigated by using bioassessments of macroinvertebrate community structure. Toxicity identification evaluations were used to characterize chemicals responsible for toxicity. Salinas River water downstream of the agricultural drain was acutely toxic to the cladoceran Ceriodaphnia dubia, and toxicity to C. dubia was highly correlated with combined toxic units (TUs) of chlorpyrifos and diazinon. Laboratory tests were used to demonstrate that sediments in this system were acutely toxic to the amphipod Hyalella azteca, a resident invertebrate. Toxicity identification evaluations (TIEs) conducted on sediment pore water suggested that toxicity to amphipods was due in part to OP pesticides; concentrations of chlorpyrifos in pore water sometimes exceeded the 10-d mean lethal concentration (LC50) for H. azteca. Potentiation of toxicity with addition of the metabolic inhibitor piperonyl butoxide suggested that sediment toxicity also was due to other non-metabolically activated compounds. Macroinvertebrate community structure was highly impacted downstream of the agricultural drain input, and a number of macroinvertebrate community metrics were negatively correlated with combined TUs of chlorpyrifos and diazinon, as well as turbidity associated with the drain water. Some macroinvertebrate metrics were also correlated with bank vegetation cover. This study suggests that pesticide pollution is the

Long-term baited lander experiments at a cold-water coral community on Galway Mound (Belgica Mound Province, NE Atlantic)

NASA Astrophysics Data System (ADS)

Lavaleye, Marc; Duineveld, Gerard; Bergman, Magda; van den Beld, Inge

2017-11-01

A long-term lander employing a baited camera system was developed to study temporal variation in the presence of scavenging fish and invertebrates at a cold-water coral community on Galway Mound (Belgica Mound Province, NE Atlantic). The camera system was tested during two successful long-term deployments for periods of 6 and 12 months respectively. The baited system, consisting of two separate video cameras with infrared lights and a bait dispenser with 24 bait positions, recorded more than 15,500 clips of 17 s, regularly spread over both periods. New bait, consisting of sardines in oil, was offered at regular time intervals, and attracted scavengers over the whole period of deployment, and especially the crab Chaceon affinis did still eat from it till the end of the deployments. However, the attractiveness for some scavengers, i.e. amphipods, diminished quite quickly. In addition to invertebrate scavengers, namely C. affinis, two other crab species, amphipods, a shrimp and a starfish, also 7 species of fish were recorded near the bait, of which Lepidion eques was by far the most common. Though there was no concrete evidence for seasonal patterns, the observations showed substantial temporal variation in the abundance of several species, especially the crabs C. affinis and Bathynectes maravigna and the fish Phycis blennoides. It is concluded that long-term deployments of such a baited camera system can produce novel data. For instance such a system could be employed for monitoring impacts of disturbances on the deep-sea floor (e.g. mining), as we infer that mobile scavengers will be among the first organisms to show a visible reaction to any chemically and physically (noise, vibrations) alteration of the environment similar to a mine canary.

Trophic interactions in the benthic boundary layer of the Beaufort Sea shelf, Arctic Ocean: Combining bulk stable isotope and fatty acid signatures

NASA Astrophysics Data System (ADS)

Connelly, Tara L.; Deibel, Don; Parrish, Christopher C.

2014-01-01

The food web structure and diets of 26 taxa of benthic boundary layer (BBL) zooplankton on the Beaufort Sea shelf were studied using carbon and nitrogen stable isotopes and fatty acids. Mean δ15N values ranged from 7.3‰ for the amphipod Melita formosa to 14.9‰ for an unidentified polychaete, suggesting that taxa sampled came from three trophic levels. For 8 taxa, the lightest carbon signature occurred near the mouth of the Mackenzie River. Stable isotope ratios helped clarify the origin of signature fatty acids. Levels of certain polyunsaturated fatty acids (PUFA) were negatively correlated with δ15N, with the exception of 22:6ω3, which was positively correlated with δ15N, suggesting that this essential PUFA was retained through the food web. Discriminant analysis proved to be a powerful tool, predicting taxa from fatty acid profiles with 99% accuracy, and revealing strong phylogenetic trends in fatty acid profiles. The amphipod Arrhis phyllonyx had higher levels of ω6 PUFA, especially 20:4ω6 with several possible sources, than other peracarid crustaceans. The holothurian had high levels of odd numbered and branched chain fatty acids, indicative of bacterial consumption, while fatty acids of phytoplankton origin were important discriminants for Calanus hyperboreus and the chaetognaths Eukrohnia hamata and Parasagitta elegans. This relationship indicates that the conventional phytoplankton-copepod-chaetognath food web found in the water column also exists in the BBL. This observation, as well as generally low δ15N and high levels of certain PUFA in samples with lower δ15N, strongly suggests that BBL zooplankton on the Beaufort Sea shelf have access to fresh material of phytoplankton origin either by feeding on sedimenting matter or by active migration to surface waters.

Anthropogenic disturbance and biodiversity of marine benthic communities in Antarctica: a regional comparison.

PubMed

Stark, Jonathan S; Kim, Stacy L; Oliver, John S

2014-01-01

The impacts of two Antarctic stations in different regions, on marine sediment macrofaunal communities were compared: McMurdo, a very large station in the Ross Sea; and Casey, a more typical small station in East Antarctica. Community structure and diversity were compared along a gradient of anthropogenic disturbance from heavily contaminated to uncontaminated locations. We examined some of the inherent problems in comparing data from unrelated studies, such as different sampling methods, spatial and temporal scales of sampling and taxonomic uncertainty. These issues generated specific biases which were taken into account when interpreting patterns. Control sites in the two regions had very different communities but both were dominated by crustaceans. Community responses to anthropogenic disturbance (sediment contamination by metals, oils and sewage) were also different. At McMurdo the proportion of crustaceans decreased in disturbed areas and polychaetes became dominant, whereas at Casey, crustaceans increased in response to disturbance, largely through an increase in amphipods. Despite differing overall community responses there were some common elements. Ostracods, cumaceans and echinoderms were sensitive to disturbance in both regions. Capitellid, dorvelleid and orbiniid polychaetes were indicative of disturbed sites. Amphipods, isopods and tanaids had different responses at each station. Biodiversity and taxonomic distinctness were significantly lower at disturbed locations in both regions. The size of the impact, however, was not related to the level of contamination, with a larger reduction in biodiversity at Casey, the smaller, less polluted station. The impacts of small stations, with low to moderate levels of contamination, can thus be as great as those of large or heavily contaminated stations. Regional broad scale environmental influences may be important in determining the composition of communities and thus their response to disturbance, but there are

Behavioural ecotoxicology, an “early warning” signal to assess environmental quality

PubMed Central

2010-01-01

Background In this review, the position of behavioural ecotoxicology within the available means to assess the status of marine environments is described as filling the gap for the needed “early warning” signals. A few examples of studies performed since the 1960s are discussed to highlight the sensitivity of these approaches in investigating the effects of chemicals, including priority pollutants and emerging contaminants, relative to conventional toxicity tests measuring survival. Discussion The advantage of the behavioural response is due to the integration of biochemical and physiological processes that reflect changes at higher levels of organisation with ecological relevance. Avoidance often represents a behavioural symptom easily detected in many animals exposed to contaminants and would be a useful test to explore more widely. This rapid response would reflect a defence mechanism protective against further exposure and the potential development of more pronounced deleterious effects, whilst in some cases, escape could lead to the relocation of a species with negative consequences. An investigation of the avoidance behaviour of mud shrimp, Corophium volutator, along with the chemical analyses of sediments and amphipods to assess the quality of harbour sediments is summarised. The body burden of the amphipods was 1,000 times lower than the one associated with narcosis, emphasizing the sensitivity of this endpoint. The application of this acute toxicity test is briefly compared to additional work that involved intertidal mussels collected in the field. Conclusions Recent research undertaken with mud snails, Ilyanassa obsoleta, and harbour sediments confirmed the usefulness of the escape behaviour as an assessment tool. However, the limits of the state of knowledge regarding the fate of contaminants in species with the ability to metabolise contaminants is further discussed along with directions to be pursued to address questions arising from the reviewed

Summer foods of lesser scaup in subarctic taiga

USGS Publications Warehouse

Bartonek, J.C.; Murdy, H.W.

1970-01-01

Twenty-five adult and 38 juvenile lesser scaup (Aythya affinis) that were collected in taiga north of Great Slave Lake, Northwest Territories, had eaten almost entirely animal material (99 i?? 1 per cent, P < 0.05). Juveniles collected in mid-summer had tended to feed on free-swimming organisms such as Chaoborinae and Conchostraca; whereas juveniles collected in late summer had tended to feed, as did adults in June, on bottom-associated organisms such as amphipods, odonates, and corixids. Sampling aquatic organisms concomitantly with collecting ducks revealed that seeds, copepods, and cladocerans were seldom or never eaten; most other organisms were consumed in proportions that were not significantly different (P < 0.05) from those in the collected samples.