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Sample records for amphipoda gammaridea hyalidae

  1. Amphipoda (crustacea) from Palau, Micronesia: families Dexaminidae, Eusiridae, Hyalidae, Ischyroceridae, Leucothoidae and Lysianassidae.

    PubMed

    Myers, A A

    2013-01-01

    Thirteen species of amphipod in the families Dexaminidae (1), Eusiridae (1), Hyalidae (1), Ischyroceridae (1), Leucothoidae (8) and Lysianassidae (1) are recorded from Palau in Micronesia. Of these, Ventojassa palauensis sp. nov., Leucothoe beobeldabensis sp.nov., L. pseudepidemos sp. nov., L. serratissima sp. nov., L. tumida sp. nov., L. whiteae sp. nov and Paranamixis dentidactylus sp. nov. are new to science and are described and figured. PMID:25277573

  2. Molecular and ultrastructural characterization of Dictyocoela diporeiae n. sp. (Microsporidia), a parasite of Diporeia spp. (Amphipoda, Gammaridea)

    PubMed Central

    2014-01-01

    Dictyocoela diporeiae n. sp. is described from Diporeia spp. (Amphipoda, Gammaridea) collected from Lake Superior (USA), and its morphology and taxonomic affiliation are discussed. In hematoxylin- and eosin-stained sections of infected amphipods, the microsporidian was observed to infect muscle tissue surrounding the ovaries. Melanized hemocytic encapsulations were often observed in or near masses of microsporidians. The microsporidians appeared as spores measuring 1.99 ± 0.09 μm long by 1.19 ± 0.05 μm wide. Each spore contained eight coils of isofilar polar filaments that were arranged in single ranks. Polar filaments measured 71 ± 3 nm in diameter. A prominent lamellar polaroplast composed of ordered concentric membranes was found at the apical end of the spore surrounding the polar filament. A distinct posterior vacuole was observed at the distal end of the spore. Phylogenetic analysis based on 16s RNA sequences showed that the microsporidian belongs to the genus Dictyocoela, and is most similar to D. berillonum, yet distinctly different. The species is new, based on its morphology, genetic sequence, host, and location within the host. PMID:24934702

  3. On the trophic ecology of Gammaridea (Crustacea: Amphipoda) in coastal waters: A European-scale analysis of stable isotopes data

    NASA Astrophysics Data System (ADS)

    Mancinelli, Giorgio

    2012-12-01

    Gammaridean amphipods are found throughout a diverse range of coastal and brackish environments and are generally considered macrophagous herbivores/detritivores. While predation and cannibalism have been shown to be common in freshwater species, motivating a revision of the group functional role, only qualitative information is available on marine Gammaridea. In this study, a survey was conducted of the available literature on stable C and N isotopic signatures of macrophagous, fully aquatic Gammaridea and their potential basal resources in European brackish and coastal environments. The contribution of intra- and inter-specific predation to the signatures of gammarideans was verified by a mixing model procedure where the diet-tissue enrichment constant was not set a priori. Specifically, for each study included in the survey the minimum and maximum diet-tissue nitrogen enrichment factors (Δ15Nmin and Δ15Nmax) providing a non-zero solution were calculated for a range of carbon enrichment factors, assuming that both metrics would increasingly differ from the values expected for a single trophic level as predation and/or cannibalism increased in the diet of the consumer. The minimum enrichment factors Δ15Nmin estimated for a Δ13C of -2.6‰ and +0.5‰ were found to be independent from resource-related artefacts and provided the highest number of successful model runs. Δ15Nmin values were consistent with a diet based on living or decaying primary producers and not compatible with cannibalism or intra-guild predation. However, they showed a bimodal distribution and were on average far below the range found in the literature, matching the enrichment factors of gammarideans measured under laboratory conditions. These results are discussed considering the interaction of the distinctive isotopic features of basal resources in coastal habitats and the biology and ecology of gammaridean amphipods. Particular emphasis is placed on the high variability of nitrogen

  4. Two new species of Urothoe (Crustacea, Amphipoda, Gammaridea) from the East Johor Islands Archipelago, Malaysia

    PubMed Central

    Azman, B.A.R.; Melvin, C.W.H.

    2011-01-01

    Abstract Two new species of urothoid amphipods from Pulau Sibu and Pulau Tinggi, Johor are described and illustrated. The specimens of Urothoe sibuensis new species were collected by vertical haul plankton net and is distinctively different from other existing Urothoe species by these combination of special characters; similar gnathopods 1–2 with short and stout propodus expanded into poorly defined palms; large eyes and epimeron 3 smooth. Urothoe tinggiensis new species as collected using an airlift suction sampler at seagrass area is characterized by its different gnathopodal configuration with setose dactylus of 5th pereopod; eyes minute; carpus is wider than merus in the 5th pereopod; subquadrate coxa 4; merus and carpus of pereopods 6–7 are linear. PMID:21594101

  5. Regional diversity of amphipoda in the Caribbean Sea.

    PubMed

    Martín, Alberto; Díaz, Yusbelly; Miloslavich, Patricia; Escobar-Briones, Elva; Guerra-García, José Manuel; Ortiz, Manuel; Valencia, Bellineth; Giraldo, Alan; Klein, Eduardo

    2013-12-01

    The order Amphipoda is one of the most diverse within Peracarids, and comprises 6950 described marine species. Amphipod research in the Caribbean Sea began in the late 1800s, but has increased significantly since 1980. In this study, we analized the amphipod biodiversity (Caprellidea, Gammaridea, Hyperiidea, and Ingolfiellidea) of the Caribbean Sea. For this, we compiled available data on species diversity of marine amphipods (data bases: WoRMS and OBIS and published species lists) into a comprehensive taxonomic list by country for the ecoregions of the Caribbean. Additionally, we analized the relative contribution of each country to regional diversity and the rate of discovery of new species. The Caribbean amphipod fauna is composed of 535 species within 236 genera and 73 families for the higher taxon. The Western Caribbean ecoregion holds the largest diversity (282 species), while the Eastern Caribbean recorded the lowest one (73). Mexico and Venezuela recorded the largest number of species with 266 and 206, respectively. Twelve countries had less than 50 species. The richest suborder is the Gammaridea with 381 species followed by the suborder Hyperiidea with 116. From the total of 535 amphipod species reported for the Caribbean region, 218 have the Caribbean as the holotype locality, and 132 are endemic (about 25% of the total). Areas of higher diversity seem to be concentrated along the Mexican Caribbean, Cuba and the Northern coast of South America (Venezuela-Colombia); however, such pattern is most likely reflecting local collection efforts and taxonomic expertise rather than actual distribution. Knowledge of amphipod species is mostly limited to shallow, near-shore waters, with little infonnation available on the deep sea fauna. Regional research priorities for this group should be focused on completing shallow water coastal inventories of species in Central America and the Greater and Lesser Antilles. In addition, sampling the deep sea ecosystems should

  6. Parhyale darvishi, a new widely distributed amphipod species, in the Persian Gulf and the Gulf of Oman (Crustacea, Amphipoda, Hyalidae).

    PubMed

    Momtazi, Farzaneh; Maghsoudlou, Abdolvahab

    2016-01-01

    Parhyale darvishi sp. nov., is described. The new species is characterized by a naked posterior margin on the propodus of pereopods 5-7, a special arrangement of robust setae on the first male gnathopod and a lack of dense fine setae on the second antennae. Parhyale darvishi sp. nov. is distributed from the western coasts of the Persian Gulf to the eastern coasts of Gulf of Oman. PMID:27395677

  7. Osornodella gabrielae, n. gen. and n. sp., a new falklandellid (Amphipoda: Gammaridea) from freshwaters of the Chilean Coastal Range.

    PubMed

    Pérez-Schultheiss, Jorge

    2013-01-01

    The first species of falklandellid amphipod outside the Falkland Islands: Osornodella gabrielae n. gen., n. sp. is described from freshwaters of subterranean origin in the Coastal Range of Osorno province, Chile. The new taxon is characterized principally by the absence of secondary sexual characters in pereopods 3-4, uropod 3 aequiramous and telson slightly cleft. The new species is described and illustrated and its morphological relationships with other known species of this group are discussed. PMID:24613998

  8. The Amphipoda of Sea City, Kuwait.-The Senticaudata (Crustacea).

    PubMed

    Myers, Alan A; Nithyanandan, Manickam

    2016-01-01

    Thirteen species of Amphipoda Senticaudata were collected in Sea City, Kuwait using a Van Veen grab and an Ocklemann sledge. Of these seven species were new to science and are described and figured in this contribution. PMID:27395936

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

    SciTech Connect

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

    1986-08-01

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

  10. A new species of Apolochus (Crustacea, Amphipoda, Gammaridea, Amphilochidae) in Maryland coastal bays, USA with notes on its abundance and distribution.

    PubMed

    Morales-Núñez, Andrés G; Chigbu, Paulinus

    2016-01-01

    A new amphilochid amphipod, Apolochus cresti sp. n. is described from specimens collected in the shallow waters of Maryland coastal bays, Mid-Atlantic region, at depths from 1.7 to 2.1 m. The new species appears to be most closely related to the northeastern Atlantic species, Apolochus neapolitanus sensu Krapp-Schickel, 1982. Apolochus cresti sp. n. can be distinguished from Apolochus neapolitanus by a combination of characters, including the shape of the lateral cephalic lobe, shape of the mandible molar process, relative length of mandible palp article 3, the carpal lobe length of gnathopod 2, and the lack of sub-marginal spines on antero-lateral surface of gnathopod 2. Spearman's rank correlation analysis indicated a positive correlation between the abundance of Apolochus cresti and the amount of macroalgae collected per station, bay, and month. Ovigerous females carrying eggs were present from March to May and in October, reaching their peak in May, although only ovigerous females carrying juveniles were found in May. Males were abundant in March and were collected also in May and October. A key for the separation of Apolochus species is presented. PMID:27110159

  11. A new species of Apolochus (Crustacea, Amphipoda, Gammaridea, Amphilochidae) in Maryland coastal bays, USA with notes on its abundance and distribution

    PubMed Central

    Morales-Núñez, Andrés G.; Chigbu, Paulinus

    2016-01-01

    Abstract A new amphilochid amphipod, Apolochus cresti sp. n. is described from specimens collected in the shallow waters of Maryland coastal bays, Mid-Atlantic region, at depths from 1.7 to 2.1 m. The new species appears to be most closely related to the northeastern Atlantic species, Apolochus neapolitanus sensu Krapp-Schickel, 1982. Apolochus cresti sp. n. can be distinguished from Apolochus neapolitanus by a combination of characters, including the shape of the lateral cephalic lobe, shape of the mandible molar process, relative length of mandible palp article 3, the carpal lobe length of gnathopod 2, and the lack of sub-marginal spines on antero-lateral surface of gnathopod 2. Spearman’s rank correlation analysis indicated a positive correlation between the abundance of Apolochus cresti and the amount of macroalgae collected per station, bay, and month. Ovigerous females carrying eggs were present from March to May and in October, reaching their peak in May, although only ovigerous females carrying juveniles were found in May. Males were abundant in March and were collected also in May and October. A key for the separation of Apolochus species is presented. PMID:27110159

  12. A new Stenothoe species (Crustacea: Amphipoda: Stenothoidae) living on Boloceropsis platei (Anthozoa: Actiniaria) from Chilean Patagonia

    NASA Astrophysics Data System (ADS)

    Krapp-Schickel, T.; Häussermann, V.; Vader, W.

    2015-06-01

    This paper describes a new species of Stenothoe (Amphipoda, Stenothoidae), S. boloceropsis sp. nov., collected among the tentacles of the sea anemone Boloceropsis platei Mc Murrich, 1904, found on sublittoral sand of Quellon, Chiloe Island, Chile.

  13. The complete mitochondrial genome of Baikalian amphipoda Eulimnogammarus vittatus Dybowsky, 1874.

    PubMed

    Romanova, Elena V; Mikhailov, Kirill V; Logacheva, Maria D; Kamaltynov, Ravil M; Aleoshin, Vladimir V; Sherbakov, Dmitry Yu

    2016-05-01

    A complete mitochondrial genome sequence of amphipoda Eulimnogammarus vittatus Dybowsky, 1874 from Lake Baikal was obtained using next-generation sequencing approach. Mitochondrial DNA with the length of 15,534 bp contains 13 protein-coding genes, 2 ribosomal RNA, 23 transfer RNA and non-coding sequences: a putative control region and 7 intergenic spacers. A brief comparative analysis of mitochondrial genomes of E. vittatus and its sister species Eulimnogammarus verrucosus was performed. PMID:25264843

  14. A new species of Paraproto (Crustacea: Amphipoda: Phtisicidae) collected from the South Shetland Islands, Antarctica

    NASA Astrophysics Data System (ADS)

    Takeuchi, Ichiro

    2015-12-01

    A new species of amphipod crustacean (Amphipoda: Phtisicidae), Paraproto mccaini n. sp. is described based on specimens collected from south of Elephant Island, the South Shetland Islands near the Antarctic Peninsula. This species was first reported as Paraproto condylata (Haswell, 1885) [sensu lato], recorded from a temperate region of Australia. P. mccaini n. sp. is distinct from P. condylata [sensu stricto] by an elongated head with pereonite 1, presence of a mid-lateral projection on pereonites 2-4, and lack of a distal round projection on the propodus of gnathopod 2. Paraproto differs from Pseudoprotomima, the most phylogenetically similar genus, in having gills on pereonites 3 and 4.

  15. Cheiriphotis trifurcata, new species (Crustacea, Amphipoda, Corophiidae, Protomedeiinae) from the Seagrass Bed of the Lower Gulf of Thailand

    PubMed Central

    Wongkamhaeng, K.; Azman, B.A.R.; Puttapreecha, R.

    2012-01-01

    Abstract A new species of corophiid Amphipoda, Cheiriphotis trifurcata, collected from the seagrass bed of the Lower Gulf of Thailand, is described. Cheiriphotis trifurcata is characterized by its trifurcated tip of the modified setae on the outer ramus in male pleopod 3. In this paper, the new species is fully described and compared with related species and a complete key of the 16 valid species in the genus Cheiriphotis is given. PMID:22577331

  16. A new species of the subterranean genus Stygobromus (Amphipoda: Crangonyctidae) from a cave spring in northern Florida, USA.

    PubMed

    Holsinger, John R; Sawicki, Thomas R

    2016-01-01

    A relatively large, distinct new species of the subterranean amphipod crustacean genus Stygobromus (Amphipoda: Crangonyctidae) measuring 13 mm in length is described from Skipper Spring, a cave spring in the northwestern "panhandle" of Florida, USA. This is the first species of the genus described from the state of Florida where it is described from only 3 females. A fourth much smaller specimen of this species was collected from nearby Miller's Crossing Spring on Holmes Creek. All other stygomorphic amphipod species recorded from the state of Florida have been in the genus Crangonyx. PMID:27395865

  17. Seawater Ca2+ concentration influences solar orientation in Talitrus saltator (Crustacea, Amphipoda).

    PubMed

    Ugolini, Alberto; Ungherese, Giuseppe; Mercatelli, Luca; Saer, Doumett; Lepri, Luciano

    2009-03-01

    The role of salinity in the ecophysiology of many intertidal invertebrates has been extensively investigated. Calcium (Ca(2+)), magnesium (Mg(2+)), potassium (K(+)) and sodium (Na(+)) are the major constituents of seawater and it has been demonstrated that sandhoppers tested under the sun in diluted seawater (3.5 per thousand) head seaward, instead of going landward as expected. Therefore, the variation in seawater salinity (from 35 per thousand to 3.5 per thousand) influences their directional choice. This paper investigates the contribution of different cations to the sea-land directional choice of Talitrus saltator (Crustacea, Amphipoda) by the sun compass orientation mechanism. Results of releases carried out in basic seawater selectively deprived of Ca(2+), Mg(2+) or K(+) and containing the same concentration of Na(+) indicate that only the reduction in Ca(2+) concentration affects the capacity of solar orientation. The pH does not influence the directional choice of sandhoppers and nor do small variations in salinity in the range 32-39 per thousand. Moreover, the clear photopositive tendency registered in experiments of phototaxis in Ca(2+)-deprived seawater indicates that the absence of Ca(2+) does not affect the normal functioning of the visual cells. Therefore, our results show that Ca(2+) seawater concentration is important for the correct functioning of one of the principal mechanisms of orientation in supralittoral amphipods and it could affect their survival in the field. PMID:19251995

  18. A new species of Siphonoecetes Krøyer, 1845 Siphonoecetes (Centraloecetes) bulborostrum sp. nov. (Crustacea, Amphipoda, Ischyroceridae) from the western Mediterranean, coast of Iberian Peninsula.

    PubMed

    De-la-Ossa-Carretero, Jose Antonio; Martí, Amparo

    2014-01-01

    An undescribed species of Siphonoecetes Krøyer, 1845 was found on Mediterranean coast of Iberian Peninsula. It was collected at the depth of 10 and 15 m near Alicante. Though it was previously found in Chafarinas Islands, this new species was not named and fully described. In the present paper, Siphonoecetes (Centraloecetes) bulborostrum sp. nov. is described. The species belongs to Centroloecetes subgenus, since it possesses bulbous ventroapical projection on peduncle of uropod 1 in males and a row of long pectinate setae on distal margin of peduncle of uropod 3. Siphonoecetes (Centraloecetes) bulborostrum sp. nov. (Crustacea, Amphipoda, Ischyroceridae) is easily distinguishable from the other Siphonoecetes reported in Iberian Mediterranean coast by presence of bulbous subrostral projection. PMID:24870885

  19. Secondary production of Ampelisca mississippiana Soliman and Wicksten 2007 (Amphipoda, Crustacea) in the head of the Mississippi Canyon, northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Soliman, Y. S.; Rowe, G. T.

    2008-12-01

    Annual production was calculated for the dominant ampeliscid amphipod Ampelisca mississippiana [Soliman, Y., Wicksten, M., 2007. Ampelisca mississippiana a new species (Amphipoda: Gammaredea) dominated the head of the Mississippi Canyon (Northern Gulf of Mexico). Zootaxa, submitted] at the head of the Mississippi Canyon in the northern Gulf of Mexico. Average densities were 12,094±2499 ind m -2, with secondary production of 6.93 g dry wt m -2 yr -1, based on the "size-frequency method" [Hynes-Hamilton, H.B.N., Coleman, M., 1968. A simple method for assessing the annual production of stream benthos. Limnology and Oceanography 13, 569-573; Menzies, C.A., 1980. A note on the Hynes-Hamilton method of estimating secondary production. Limnology and Oceanography 25(4), 770-773], with a production/biomass ( P/ B) ratio of 3.11. Growth rates of this magnitude are comparable to available data for freshwater and shallow marine ampeliscids, but are unexpectedly high for deep-ocean habitats. Growth efficiency appeared to be approximately 35% (Growth/Assimilation×100).

  20. A comparative study on the tubes and feeding behaviour of eight species of corophioid Amphipoda and their bearing on phylogenetic relationships within the Corophioidea

    PubMed Central

    Dixon, I. M. T.; Moore, P. G.

    1997-01-01

    Observations are presented on mouthpart functional morphology, and on feeding, grooming and defaecatory behaviour of eight species of corophioid Amphipoda, viz. Corophium bonnellii, Lembos websteri, Aora gracilis, A. spinicornis, Gammaropsis nitida, Ericthonius punctatus, Jassa falcata and J. marmorata. These data are considered in relation to tube structure and amphipod posture in relation to the tube. All these species occupy double-ended cylindreical tubes made from 'amphipod silk' secreted by the third and fourth preraeopods, incorporating sediment and other debris to varying degrees. Uniquely among this set of species, however, E. punctatus has a tube that is architecturally distinct. It tapers along its length and has a distinctive oblique main entrance at its widest end. This end is used preferentially. The other species studied use either opening with equal facility. Such a feature is adaptive in facilitating deployment of the antennae and shielding the head of E. punctatus. Two groupings of species are propose: group A which feed inside their tube using pleopod-induced through-tube currents, and group B which feed outside or at the entrance to their tube using external water currents. Group A includes C. bonnellii, L. websteri and the Aora species. Group B includes E. punctatus and the Jassa species. Gammaropsis nitida exhibits traits from both groups, adding weight to its perceived status as a genus representative of the stem corophioid. The ischyrocerid habit of externalizing food-gathering may be regarded as the first step along an evolutionary line leading to the rod-building podocerid types and ultimately towards the caprellids. All species examined show a degree of flexibility in their feeding habits which helps to explain the success of this taxon, which has radiated into a great diversity of aquatic biotopes.

  1. Caprellids (Crustacea: Amphipoda) from India

    NASA Astrophysics Data System (ADS)

    Guerra-García, J. M.; Ganesh, T.; Jaikumar, M.; Raman, A. V.

    2010-12-01

    The caprellid fauna of India is investigated. A total of 538 samples (including algae, seagrasses, sponges, hydroids, ascidians, bryozoans, encrusted dead corals, coral rubble, fine and coarse sediments) were collected from 39 stations along the coast of India, covering a wide diversity of habitats from intertidal to 12 m water depth. A new species ( Jigurru longimanus n.sp.) is described, and figures of the 11 valid species reported so far from India are given together with a key for their identification. No caprellids were found in sediments from the northeast (16-20ºN) coast of India while they were abundant in the southeast and west coast. Decreases in salinity due to river discharges associated with lower values of oxygen, higher water temperatures and lower nutrient inputs along the east coast could explain these differences in caprellid composition between the two coastlines. Significantly, lower abundance of caprellids in India, as in other tropical ecosystems, is probably related to the lack of species belonging to the genus Caprella, which reach very high abundances in temperate waters.

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

    SciTech Connect

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

    1989-01-01

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

  3. 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 disappearance of O. effeminans. In both microsporidians, long exposure to low temperatures (≤4°C) produces eggs which are not all parasitized. Furthermore, intersexuality can be induced by changing environmental factors. Microsporidian species have no influence on sex differentiation in G. duebeni celticus, G. salinus, G. locusta and G. pulex. Patterns of relative electrophoretic mobilities of proteins and the distribution of allele frequencies at polymorphic gene loci can be utilized for species diagnosis and for the evaluation of the relationships between different taxa, particularly at and below the species level. As exemplified by studies on several gammarids from marine, brackish and freshwater environments, inter- and infraspecific gene-enzyme variation is described. Electrophoretic investigations on natural populations of the euryhaline amphipods G. zaddachi, G. salinus, G. tigrinus and others from different geographic areas provided evidence of considerable biochemical genetic variation. In Talitrus saltator- and Talorchestia deshayesii-populations the extent of variability based on micro-and macrogeographic aspects is illustrated. The large-scale genetic divergence is demonstrated by comparison of samples obtained from the Baltic, North, Atlantic and northern Mediterranean Seas.

  4. Toxicity of stormwater treatment pond sediments to Hyalella azteca (Amphipoda)

    SciTech Connect

    Karouna-Renier, N.K.; Sparling, D.W.

    1997-04-01

    Stormwater runoff from highways and commercial, industrial, and residential areas contains a wide spectrum of pollutants including heavy metals, petroleum hydrocarbons, pesticides, herbicides, sediment, and nutrients. Recent efforts to reduce the impacts of urbanization on natural wetlands and other receiving waters have included the construction of stormwater treatment ponds and wetlands. These systems provide flood control and improve water quality through settling, adsorption, and precipitation of pollutants removing up to 95% of metals, nutrients and sediment before discharged from the site. The design of stormwater ponds to provide habitat for aquatic wildlife has prompted concern over the potential exposure of aquatic organisms to these contaminants. Aquatic sediments concentrate a wide array of organic and inorganic pollutants. Although water quality criteria may not be exceeded, organisms living in or near the sediments may be adversely affected. The availability of chemicals in sediments depends strongly on the prevailing chemistry. Physical conditions of the sediment and water quality characteristics including pH, redox potential and hardness, also influence contaminant availability. Studies have shown that heavy metals and nutrients carried by runoff concentrate in the sediment of stormwater ponds. Although several investigations have assessed the toxicity of sediments in streams receiving urban runoff, there have been few studies of the toxicity of stormwater treatment pond sediments to aquatic organisms. This study was part of a large-scale assessment of the contaminant hazards of stormwater treatment ponds. The objective of this study was to evaluate the toxicity of sediments and water from stormwater ponds over a 10-d period to juvenile Hyalella azteca. Bioassay results were related to concentrations of acid volatile sulfides and metals of the tested sediments. 17 refs., 4 tabs.

  5. The tropical talitrid genus Floresorchestia (Crustacea, Amphipoda, Talitridae).

    PubMed

    Lowry, J K; Springthorpe, R T

    2015-01-01

    Floresorchestia floresiana (Weber, 1892) from Flores, F. anomala (Chevreux, 1901) from the Seychelles, F. malayensis (Tattersall, 1922) from Singapore and F. thienemanni (Schellenberg, 1931) from Java are redescribed based on original type material or newly collected material from near the type locality. Nine new species are described, in the widespread Indo-West Pacific and Caribbean talitrid genus Floresorchestia: F. andrevo sp. nov. and F. itampolo sp. nov. from Madagascar; F. kalili sp. nov. from the Bismarck Archipelago, Papua New Guinea; F. laurenae sp. nov. from Timor-Leste; F. oluanpi sp. nov. from southern Taiwan; F. papeari sp. nov. from Tahiti; F. serejoae sp. nov. from far north Queensland, Australia; F. seringat sp. nov. from Singapore; and F. yap sp. nov. from Micronesia; plus Floresorchestia sp. 1 from Hainan Island, South China Sea, Floresorchestia sp. 2 from Kilakarai and other sites in south-eastern India and Floresorchestia sp. 3 from Phuket Island, Thailand. Floresorchestia contains 28 species. In this paper all are catalogued and diagnosed. PMID:25781854

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

    PubMed

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

    2003-01-01

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

  7. Fish parasites in the bathyal zone: The halosaur Halosauropsis macrochir (Günther, 1878) from the Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Klimpel, S.; Palm, H. W.; Busch, M. W.; Kellermanns, E.

    2008-01-01

    A total of 42 Halosauropsis macrochir from a single position on the Mid-Atlantic Ridge (MAR) were collected for studies on parasites and feeding ecology. A total of 9 different parasite species were found, with most of them belonging to the Digenea (4 species) and Nematoda (3). The host specific Degeneria halosauri, (Digenea) and Cystidicolidae indet. (Nematoda) were the predominant species, reaching a prevalence of 100.0% and 57.1% with intensities of infection of 1-12 and 1-10, respectively. Less host specific parasites such as Gonocerca phycidis (Digenea) and Tetraphyllidea indet. (Cestoda) occurred at low rates of infection. The parasite fauna of this bathyal fish can be described as predominantly adult and host specific, with larval and less host specific components. A total of 16 different food groups were identified, most of them of benthic origin or associated with the benthopelagial. The predominant prey organisms belonged to the Crustacea (e.g., Copepoda, Gammaridea, Amphipoda and Isopoda), which serve as main parasite vectors for H. macrochir. This deep-sea fish seems to follow a general pattern of fish parasites in the deep sea, with most isolated parasites belonging to the digeneans, nematodes and a cestode. The parasite composition is caused by the narrow depth range of the species and the restricted distribution of the fish family Halosauridae. The species richness was found to be lower than other demersal fish from the deep sea and shallow waters, however, higher than those from deep-sea fish living in the pelagial.

  8. Towards Integrated Multi-Trophic Aquaculture: Lessons from Caprellids (Crustacea: Amphipoda).

    PubMed

    Guerra-García, José Manuel; Hachero-Cruzado, Ismael; González-Romero, Pablo; Jiménez-Prada, Pablo; Cassell, Christopher; Ros, Macarena

    2016-01-01

    The search for alternative live feed organisms and the progression of Integrative Multi-Trophic Aquaculture (IMTA) are currently being highly prioritised in EU strategies. Caprellids could potentially be an important exploitable resource in aquaculture due to their high levels of beneficial polyunsaturated fatty acids, fast growing nature and widespread distribution. Furthermore, since they are mainly detritivorous, they could be excellent candidates for integration into IMTA systems, potentially benefitting from uneaten feed pellets and faeces released by cultured fish in fish farms and sea-cage structures. Despite this, there is a lack of experimental studies to: (i) test inexpensive diets for caprellids, such as detritus, (ii) develop sustainable caprellid culture techniques and (iii) include caprellids in IMTA systems. The main aim of this study was to determine whether detritus (D) in the form of fish faeces provided an adequate diet for caprellids in comparison to other traditional diets, such as Artemia nauplii (A) or phytoplankton (P). Adult survival rate was shown to be significantly higher for caprellids fed with D. Conversely, hatchlings had the highest survival rate with A, although the juvenile growth rate and number of moults was similar in the three diets. With regard to lipid composition, caprellids fed with A had higher concentrations of Triacylglycerols (TAG) and Phosphatidylcholine (PC) while those fed with P or D were richer in polyunsaturated fatty acids, especially 22:6(n-3) (DHA). Interestingly, caprellids fed with D were also a rich source of 18:2(n-6) (LA), considered to be an essential fatty acid in vertebrates. It was found that detritus based mainly on fish faeces and uneaten feed pellets can be considered an adequate feed for adult caprellids, providing a source of both omega-3 (DHA) and omega-6 (LA) fatty acids. Hatchlings however seem to require an additional input of TAG and PC during juvenile stages to properly grow. PMID:27124465

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

    PubMed

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

    2016-10-01

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

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

    PubMed

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

    2011-01-01

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

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

    PubMed

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

    2016-08-01

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

  12. Spatio-temporal dynamics of parasites infecting Diporeia spp. (Amphipoda, Gammaridae) in southern Lake Michigan (USA).

    PubMed

    Winters, Andrew D; Fitzgerald, Scott; Brenden, Travis O; Nalepa, Thomas; Faisal, Mohamed

    2014-09-01

    Since the 1990s, populations of the benthic amphipod Diporeia spp. (Diporeia) have sharply declined across much of the Laurentian Great Lakes. This study was undertaken to identify contemporary and historical community composition, structure, and dynamics of parasites infecting Diporeia collected from nine sites in the southern basin of Lake Michigan, where declines of the amphipod have been well documented over the past 20years. An additional aim of this study was to assess whether infection dynamics and dreissenid densities could explain the declines in Diporeia densities that have occurred. We found that Diporeia were host to eight groups of uni- and multicellular pathogens. Of the 3082 amphipods analyzed, 1624 individuals (52.7%) were infected with at least one type of parasite. Ciliophora was the most prevalent parasite (50.08% prevalence of infection), followed by Gregarinasina (2.79%), Microsporidia (0.68%), Cestoda (0.45%), Acanthocephala (0.36%), Haplosporidia (0.23%), Yeast (0.32%), and filamentous Fungi (0.10%). Considerable spatial and temporal variability were observed in parasite prevalences, with prevalences frequently appearing to cycle between low and high values. Parasite species belonging to Microsporidia and Haplosporidia were associated with tissue alteration and host inflammatory response; however, parasite prevalences explained very little in terms of Diporeia density declines at assessed sites. Despite these findings, we do not discount the possibility that parasitic infections may have played a role in declining Diporeia densities in the Great Lakes, as the cyclical prevalences that were observed are possibly suggestive of parasitic outbreaks that are followed by die-offs at affected sites. This study suggests that if parasites have affected Diporeia densities in the Laurentian Great Lakes, then the relationship may be a complicated one. PMID:24991698

  13. A new species of Monoliropus Mayer, 1903 (Crustacea, Amphipoda, Caprellidae) from Korean waters

    PubMed Central

    Hong, Soon-Sang; Heo, Jun-Haeng; Kim, Young-Hyo

    2015-01-01

    Abstract A new species of the genus Monoliropus belonging to the family Caprellidae was collected from the Yellow Sea, Korea. The new species differs from Monoliropus agilis Mayer, 1903, Monoliropus kazemii Momtazi & Sari, 2013, and Triprotella amica Arimoto, 1970 as follows: 1) gnathopod 1 subrectangular; 2) pereonites 2–3 with acute triangular processes anterolaterally; 3) mandibular palp, apical article with four simple setae subdistally. The new species is fully illustrated and extensively compared with related species. This is the first record of the genus Monoliropus from Korean waters. A key to Monoliropus species is also given. PMID:26312030

  14. Amphipoda (Crustacea) from Palau, Micronesia: Families Ampeliscidae, Ampithoidae, Aoridae, Colomastigidae and Cyproideidae

    PubMed Central

    Myers, Alan A.

    2012-01-01

    Abstract 12 species of amphipod in 5 families, collected from shallow reefs in Palau by S. DeGrave during 2002, are reported here. Of these, five species are new to science and Microdeutopus tridens Schellenberg (1938) is redescribed and transferred to the genus Bemlos Shoemaker (1925). The collection included several additional species in the genera Amphilochus Bate, 1862, Ampithoe Leach (1814), Bemlos, Byblis Boeck (1871), Colomastix Grube (1861) and Notopoma Lowry & Berents (1996), that were either incomplete or juvenile and could therefore not adequately be described. In addition, two new species of Plumithoe Barnard & Karaman (1991) are erected from the literature. Other families collected in Palau will be considered in later contributions. PMID:22679377

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

    PubMed

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

    2015-09-01

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

  16. Towards Integrated Multi-Trophic Aquaculture: Lessons from Caprellids (Crustacea: Amphipoda)

    PubMed Central

    Hachero-Cruzado, Ismael; González-Romero, Pablo; Jiménez-Prada, Pablo; Cassell, Christopher; Ros, Macarena

    2016-01-01

    The search for alternative live feed organisms and the progression of Integrative Multi-Trophic Aquaculture (IMTA) are currently being highly prioritised in EU strategies. Caprellids could potentially be an important exploitable resource in aquaculture due to their high levels of beneficial polyunsaturated fatty acids, fast growing nature and widespread distribution. Furthermore, since they are mainly detritivorous, they could be excellent candidates for integration into IMTA systems, potentially benefitting from uneaten feed pellets and faeces released by cultured fish in fish farms and sea-cage structures. Despite this, there is a lack of experimental studies to: (i) test inexpensive diets for caprellids, such as detritus, (ii) develop sustainable caprellid culture techniques and (iii) include caprellids in IMTA systems. The main aim of this study was to determine whether detritus (D) in the form of fish faeces provided an adequate diet for caprellids in comparison to other traditional diets, such as Artemia nauplii (A) or phytoplankton (P). Adult survival rate was shown to be significantly higher for caprellids fed with D. Conversely, hatchlings had the highest survival rate with A, although the juvenile growth rate and number of moults was similar in the three diets. With regard to lipid composition, caprellids fed with A had higher concentrations of Triacylglycerols (TAG) and Phosphatidylcholine (PC) while those fed with P or D were richer in polyunsaturated fatty acids, especially 22:6(n-3) (DHA). Interestingly, caprellids fed with D were also a rich source of 18:2(n-6) (LA), considered to be an essential fatty acid in vertebrates. It was found that detritus based mainly on fish faeces and uneaten feed pellets can be considered an adequate feed for adult caprellids, providing a source of both omega-3 (DHA) and omega-6 (LA) fatty acids. Hatchlings however seem to require an additional input of TAG and PC during juvenile stages to properly grow. PMID:27124465

  17. The life history and sexual biology of Pseudunciola obliquua (crustacea: amphipoda) in the New York Bight

    NASA Astrophysics Data System (ADS)

    Morgan, M. A.; Woodhead, P. M. J.

    1984-06-01

    Pseudunciola obliquua is the most abundant subtidal amphipod of the near-shore macrobenthos in the New York Bight south of Fire Island. It has an annual life-cycle. Breeding occurs in March and April, and a single brood of between 8 and 20 eggs per female is produced. Fecundity is linearly proportional to maternal length. The eggs take about two months to develop; the juveniles emerge in June and July. Initial recruitment in the study area was estimated to be 2980 and 5850 per m 2 for the 1979-1980 and 1980-1981 year classes, respectively. Of the initial recruits only about 10% survive to form the reproductive stock of the following spring. Females and males grow at similar rates and are equally abundant as juveniles and initially as adults, until they reach sexual maturity. After breeding, the abundance of males decreases rapidly due to post-reproductive death. Females continue to live, carrying the developing eggs in their brood pouches. Mean female growth increases throughout the brooding period until the young are released, shortly after which adult females also die. The entire generation of reproductive adults has died by September.

  18. New talitrids from South Africa (Amphipoda, Senticaudata, Talitroidea, Talitridae) with notes on their ecology.

    PubMed

    Lowry, J K; Baldanzi, S

    2016-01-01

    Based on new talitrid amphipod collections from South Africa one new genus, Capeorchestia gen. nov., and one new species, Africorchestia meridionalis sp. nov., are described and Africorchestia quadrispinosa (K.H. Barnard, 1916) is redescribed. Eorchestia Bousfield, 1984 is redescribed. Based on this redescription Orchestia dassenensis (K.H. Barnard, 1916) is moved to Eorchestia and the Tasmanian species Eorchestia palustris Richardson, 1993 and E. rupestris Richardson, 1993 are moved to Microrchestia Bousfield, 1984. The current knowledge about the ecology of Capeorchestia capensis (Dana, 1853), Africorchestia quadrispinosa and A. meridionalis is summarized. PMID:27470846

  19. Commensal Leucothoidae (Crustacea, Amphipoda) of the Ryukyu Archipelago, Japan. Part II: sponge-dwellers

    PubMed Central

    White, Kristine N.; Reimer, James Davis

    2012-01-01

    Abstract Commensal leucothoid amphipods have been collected from the canals of their sponge hosts throughout the Ryukyu Archipelago, Japan. Eleven new species are described in the genus Leucothoe with valuable location data and host records. An identification key to sponge-dwelling Leucothoidae of the Ryukyu Archipelago is provided. PMID:22328858

  20. Butyltin concentrations along the Japanese coast from 1997 to 1999 monitored by Caprella spp. (Crustacea: Amphipoda).

    PubMed

    Takeuchi, Ichiro; Takahashi, Shin; Tanabe, Shinsuke; Miyazaki, Nobuyuki

    2004-06-01

    The concentrations of butyltins along the Japanese coastline were investigated from 1997 to 1999, 7 to 9 years after implementation of legislation limiting the use of tributyltin (TBT) in Japan. Seawater was sampled at 0.5 m depth, and Caprella spp. were collected from Sargassum spp. and aquaculture facilities from 18 areas within four broad areas along the coastline of Japan, i.e., the Pacific coast of northern Japan, the coast along the Sea of Japan, Tokyo Bay and adjacent areas, and western Japan. Butyltins (MBT, DBT and TBT) were detected in 32 of the 63 seawater samples with average concentrations of 4.6 ng MBT/l, 4.5 ng DBT/l and 6.8 ng TBT/l, respectively. Butyltin concentrations in seawater from western Japan indicate "hot spots" even in unpopulated areas. Butyltins (MBT, DBT and TBT) were detected in all samples of Caprella spp., varying from 2.3 ng BTs /g wet wt in C. penantis R-type from Tobishima Island in the Sea of Japan to 464 ng BTs /g wet wt in C. decipiens Mayer from Amakusa, western Kyushu. The BT concentrations in Caprella spp. form western Japan were significantly higher than those from other areas, including Tokyo Bay and adjacent areas, where large scale industry and international ports are located. These results indicate that butyltin contamination still remains even in unpopulated areas after the regulation on TBT usage, and that the regulation governing TBT usage since 1990 has not been effective enough to concede recovery of shallow water ecosystems around Japan. PMID:14967521

  1. The iron-encrusted microbial community of Urothoe poseidonis (Crustacea, Amphipoda)

    NASA Astrophysics Data System (ADS)

    Gillan, David C.; Ribesse, Jérôme; de Ridder, Chantal

    2004-06-01

    A rust-coloured coating frequently covers the appendages and sternites of Urothoe poseidonis, an amphipod living in the burrow of the echinoid Echinocardium cordatum. Up to 80% of the collected amphipods were coated. In winter, coated amphipods were always more abundant than uncoated ones. In summer, uncoated specimens predominated. The aspect, location and development of the coating are similar in juveniles and adults. EDAX analyses and Prussian blue testing indicate that the rust-coloured coating contains iron oxyhydroxide minerals with trace metals and phosphorus. Scanning electron microscopy shows that the iron coating harbours bacterial filaments related to Beggiatoaceae (3 morphotypes were observed). Protozoans, possibly Peritrichia of the families Rovinjellidae or Vaginicolidae (one morphotype), were also observed on pereopods VI and VII. The formation of the iron coating and its potential role in the biology of the amphipod are discussed.

  2. A new species of Hyalella (Crustacea, Amphipoda, Dogielinotidae) from the Atlantic Forest of Misiones, Argentina

    PubMed Central

    Colla, María Florencia; César, Inés Irma

    2015-01-01

    Abstract The freshwater genus Hyalella Smith, 1874 has a distribution restricted to the Western Hemisphere with most species being found in South America. In this report we describe a new species of Hyalella from the Atlantic Forest of the Misiones province, Argentina. PMID:25685030

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

    PubMed

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

    2015-10-01

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

  4. Ingolfiella maldivensis sp. n. (Crustacea, Amphipoda, Ingolfiellidae) from coral reef sand off Magoodhoo island, Maldives

    PubMed Central

    Vonk, Ronald; Jaume, Damiá

    2014-01-01

    Abstract A new species of marine interstitial wormshrimp, Ingolfiella maldivensis, is described from coral sand on the inner and outer reef off Magoodhoo island, Faafu atoll, Maldives. Six females were found and compared to other species from the Maldives and those bordering the Indian Ocean and beyond. Morphological resemblance ties it to a species from the Caribbean island of Curaçao. Both species are found in shallow sublittoral interstitial spaces. PMID:25408614

  5. Community structure of caprellids (Crustacea: Amphipoda: Caprellidae) on seagrasses from southern Spain

    NASA Astrophysics Data System (ADS)

    González, A. R.; Guerra-García, J. M.; Maestre, M. J.; Ruiz-Tabares, A.; Espinosa, F.; Gordillo, I.; Sánchez-Moyano, J. E.; García-Gómez, J. C.

    2008-09-01

    The community structure of caprellids inhabiting two species of seagrass ( Cymodocea nodosa and Zostera marina) was investigated on the Andalusian coast, southern Spain, using uni and multivariate analyses. Three meadows were selected (Almería, AL; Málaga, MA; Cádiz, CA), and changes in seagrass cover and biomass were measured from 2004 to 2005. Four caprellid species were found; the density of Caprella acanthifera, Phtisica marina and Pseudoprotella phasma was correlated to seagrass biomass. No such correlation was found for Pariambus typicus, probably because this species inhabits sediments and does not cling to the seagrass leaves. We recorded a significant decrease in seagrass cover and biomass in MA due to illegal bottom trawling fisheries. Phtisica marina and P. typicus were favoured by this perturbation and increased their densities after the trawling activities. A survey of reports on caprellids in seagrass meadows around the world showed no clear latitudinal patterns in caprellid densities (ranging from 6 to 1,000 ind/m2 per meadow) and species diversity. While caprellid abundances in seagrass meadows are often very high, the number of species per meadow is low (range 1-5).

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

    PubMed

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

    2016-01-01

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

  7. Molecular phylogeny of Niphargus boskovici (Crustacea: Amphipoda) reveals a new species from epikarst.

    PubMed

    Švara, Vid; Delić, Teo; Rađa, Tonći; Fišer, Cene

    2015-01-01

    We describe a new species of an amphipod Niphargus zagorae sp. n. and redescribe its nearest relative and morphologically similar species N. boskovici S. Karaman, 1952. We present the geographic distributions of both species, morphological diagnoses and infer their phylogenetic position within the genus based on COI, 28S and H3 markers. PMID:26250278

  8. Caprella suprapiscis sp. nov. (Crustacea: Amphipoda: Caprellidae) from the Pacific coast of Mexico.

    PubMed

    Galván-Villa, Cristian M; Ayón-Parente, Manuel

    2015-01-01

    A new species of caprellid, Caprella suprapiscis sp. nov., is described based on several specimens collected from Bahía Chamela, Jalisco, Mexico. All specimens were found in association with the scorpionfish Scorpaena mystes. Caprellids are set on the dorsal surface of fishes. The species is distinguished by head with a short dorsal projection, eyes distinctive, body slender and smooth, peduncular articles of antenna 1 not setose, antenna 2 with swimming setae, gnathopod 2 with three ventral projections in males. The species is close to C. californica, C. mercedesae, and C. scaura for a sharp spine on the forehead but can be distinguished by gnathopod 2 finely setose, and basis of gnathopod 2 shorter. PMID:26248940

  9. Amphipoda (Crustacea) from Palau, Micronesia: families Melphidippidae, Oedicerotidae, Photidae, Pleustidae, Podoceridae, Stenothoidae, Synopiidae and Talitridae.

    PubMed

    Myers, A A

    2014-01-01

    Eleven species belonging to the families Melphidippidae, Oedicerotidae, Photidae, Pleustidae, Podoceridae, Stenothoidae, Synopiidae and Talitridae are recorded from Palau, Micronesia. Eight species are figured. One species is new to science and is described and figured. One species was previously known only from Australia, one only from Madagascar and one only from Fiji. PMID:24943185

  10. Amphipoda (crustacea) from palau, micronesia: families ampeliscidae, ampithoidae, aoridae, colomastigidae and cyproideidae.

    PubMed

    Myers, Alan A

    2012-01-01

    12 species of amphipod in 5 families, collected from shallow reefs in Palau by S. DeGrave during 2002, are reported here. Of these, five species are new to science and Microdeutopus tridens Schellenberg (1938) is redescribed and transferred to the genus Bemlos Shoemaker (1925). The collection included several additional species in the genera Amphilochus Bate, 1862, Ampithoe Leach (1814), Bemlos, Byblis Boeck (1871), Colomastix Grube (1861) and Notopoma Lowry & Berents (1996), that were either incomplete or juvenile and could therefore not adequately be described. In addition, two new species of Plumithoe Barnard & Karaman (1991) are erected from the literature. Other families collected in Palau will be considered in later contributions. PMID:22679377

  11. Maeridae from the Indo-Pacific: Elasmopus, Leeuwinella gen. nov., Maeropsis, Pseudelasmopus and Quadrimaera (Amphipoda: Crustacea).

    PubMed

    Hughes, Lauren E

    2015-01-01

    Twenty-two species of Maeridae including the new genus, Leeuwinella, and eight new species are described from Indo-Pacific waters. Leeuwinella mistakensis gen. et sp. nov. from southern Western Australia has dorsal carinae and serrate epimeral margins on pleonites 1-3 and mandibular palp article 3 concave; this significant combination of characters justifies erection of a new genus. Elasmopus coxacallus sp. nov., with a castelloserrate posterior margin of pereopod 7 presents a novel character for the genus, which contains over 100 described species. Elasmopus incomptus sp. nov. and E. norfolkensis sp. nov. are also described from Norfolk Island, South Pacific, while new distribution records are provided for E. gracilis Schellenberg, 1938, E. integer Myers, 1989, and E. molokai J.L. Barnard, 1970 from northwestern Australia, and E. souillacensis Appadoo & Myers, 2003, from the Kermadec Islands. New distribution records for Maeropsis griffini (Berents, 1983) from Bedout Island in Western Australia are the first of the species outside the Queensland type locality and new records of M. thetis (Lowry & Springthorpe, 2005) from mainland Australia to Tasmania and across the Tasman Sea extending its range. Pseudelasmopus walkerae sp. nov. is described from Norfolk Island, and is the second species recorded in the genus, previously known only from Mauritius. Lastly, three new Quadrimaera species, Q. gregoryi, Q. brownorum and Q. vallaris, along with eight known Quadrimaera species, are reported from various locations extending their distributions in the Indo-Pacific. PMID:26701562

  12. A new species of Jesogammarus from the Iki Island, Japan (Crustacea, Amphipoda, Anisogammaridae)

    PubMed Central

    Tomikawa, Ko

    2015-01-01

    Abstract A new species of anisogammarid amphipod, Jesogammarus (Jesogammarus) ikiensis sp. n., is described from freshwaters in the Iki Island, Nagasaki Prefecture, Japan, based on results of morphological and molecular analyses. The new species is distinguished from all members of the genus by the combination of small number of setae on dorsal margins of pleonites 1–3, short and small number of setae on posterior margins of peduncular articles of antennae, mandibular article 1 without setae, well developed posterior lobes of accessory lobes of coxal gills on gnathopod 2 and pereopods 3–5, and pectinate setae on palmar margin of female gnathopod 2. A key to all the species of Jesogammarus is provided. PMID:26692798

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

    PubMed

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

    2015-03-01

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

  14. Mallacoota misool, a new species of Maeridae from West Papua (Crustacea: Peracarida: Amphipoda).

    PubMed

    Hughes, Lauren E

    2016-01-01

    The new species Mallacoota misool is described from the West Macleur Gulf, West Papua. Mallacoota misool sp. nov. is exceptionally similar to the geographically close M. chandaniae Lowry & Springthorpe, 2005 known from the Gulf of Carpentaria in northern Australia and also reported from the South China Sea. Both species have a massive gnathopod 2 propodus defined by two large teeth. Mallacoota misool sp. nov. has the palm medial surface without a dense bunch of seta, which is present in M. chandaniae. PMID:27395949

  15. A new species of Cyphocarididae (Crustacea, Amphipoda, Lysianassoidea) from off the northeastern Brazilian coast.

    PubMed

    Sorrentino, Rayane; Alves, Jessika; Johnsson, Rodrigo; Senna, André R

    2016-01-01

    This paper describes a species of the genus Cyphocaris Boeck, 1871, the first record of the family Cyphocarididae Lowry & Stoddart, 1997 from Brazil. Two specimens, both females, were found in the stomach contents of a tuna caught in the Saint Peter and Saint Paul Archipelago. The new species is characterized by coxae 4 and 5 both large, coxa 4 partially overlapping coxae 2-3; coxa of pereopod 5 with ventral laminar projection and well-developed anteroventral lobe, broadly rounded and apically folded backwards, basis with anterior margin broadly rounded and posterior margin with large subacute naked projection (or spur); uropod 3, outer ramus paddle-shaped; and telson elongate and deeply cleft, with a nail. PMID:27615935

  16. Life History Traits of the Invader Dikerogammarus villosus (Crustacea: Amphipoda) in the Moselle River, France

    NASA Astrophysics Data System (ADS)

    Devin, Simon; Piscart, Christophe; Beisel, Jean-Nicolas; Moreteau, Jean-Claude

    2004-01-01

    The latest threatening invader in European freshwaters is Dikerogammarus villosus, a large gammarid of Ponto-Caspian origin exhibiting a predatory behaviour. Its biology and population dynamics were studied over a one-year period in a recipient ecosystem to determine bio/ecological traits having facilitated its rapid establishment. The study revealed that D. villosus reaches sexual maturity early, at six mm in length, and produces three reproductive peaks, though the species reproduces all year long, hence reflecting its multivoltine character. The study also revealed a female-biased sex ratio, exceptional growth rates of up to 2.6 mm in two-weeks in spring, and one of the highest fecundities of Western Europe gammarids. D. villosus exhibits a biological profile suggesting that only a few individuals can rapidly establish a new population in a recipient ecosystem, and allow this gammarid to become cosmopolitan in the near future. (

  17. Population dynamics and production of Themisto gaudichaudii (Amphipoda, Hyperiidae) at South Georgia, Antarctica

    NASA Astrophysics Data System (ADS)

    Watts, Jamie; Tarling, Geraint A.

    2012-01-01

    The population dynamics, individual growth rates and productivity of the hyperiid amphipod Themisto gaudichaudii were studied in Cumberland Bay, a fjord on the north-eastern coast of South Georgia. The study involved the weekly sampling of the population and its potential food with a Rectangular Midwater Trawl (RMT1) at weekly intervals between May 2005 and October 2006. Offshore samples were taken the previous austral summer using an RMT8 net. T. gaudichaudii produced one main cohort in the spring (September/October) and a secondary weaker cohort in the late summer (January/February). The main cohort appeared at the time of phytoplankton increase, about 3 weeks before an increase in mesozooplankton. Larger individuals (20-25 mm) resided offshore but not within the Bay during the main recruitment period. T. gaudichaudii grew at an average rate of 0.1 mm d -1 during the first four months after release and then by 0.07 mm d -1 for the subsequent four months. At these rates, it is possible that the main cohort reaches reproductive size in time to spawn the autumn cohort, although the relative weakness of the autumn cohort suggests that few manage this. T. gaudichaudii biomass reached its highest levels in November at a mean value of 5.4 mg DW m -3 while daily production was also highest in November at a mean value of 0.17 mg DW m -3 d -1. The P/B d -1 ratio varied between 0.03 d -1 in the summer to below 0.01 d -1 in the winter. Daily mortality rate was initially 0.12 d -1 during the first two months post-recruitment, falling to 0.03 d -1 for the remainder of the year. Integrating production over the year gave a value of 10.04 mg DW y -1, equivalent to 3.62 mg C m -3 y -1, making T. gaudichaudii a relatively productive component of the pelagic community. During the summer, the species was estimated to consume around 1-2% of available mesozooplankton biomass and a mean of 15% of mesozooplankton daily productivity. T. gaudichaudii may have a controlling influence on mesozooplankton dynamics as well as on the recruitment of the larval stages of important commercially fished species such as Antarctic krill ( Euphausia superba) and Mackerel icefish ( Champsocephalus gunnari).

  18. New species of Nuuanu (Amphipoda: Nuuanuidae) from Norfolk Island, Torres Strait and the Cocos (Keeling) Islands.

    PubMed

    Hughes, L E; Bopiah, A

    2013-01-01

    Three new species of Nuuanu, N. quintalana sp. nov., N. stuckeyorun sp. nov. and N. titaseyi sp. nov. are described from Norfolk Island, Tasman Sea; Cocos (Keeling) Islands, Indian Ocean and the Torres Strait, Australia, respectively. There are currently 17 described species of Nuuanu with the genus distributed world-wide. PMID:26287075

  19. A new Psammogammarus (Amphipoda: Eriopisidae) from anchialine pools on the Exuma Cays, Bahamas.

    PubMed

    Jaume, Damià; Iliffe, Thomas M; Van Der Ham, Joris L

    2013-01-01

    Psammogammarus lucayensis sp. nov. is described from anchialine pools on Little Iguana Cay (Exuma Cays, Great Bahama Bank). It can be easily distinguished from the other 14 members of the genus by the combination of: 1) carpus of G2 longer than broad; 2) male G2 palm margin non-excavated, evenly convex and devoid of strong mid-palmar robust setae; 3) basis of P7 with subparallel margins; 4) armature arrangement of ventral margin of epimeral plates as 0-2-3; 5) posteroventral angle of epimeral plate III strongly produced; 6) protopod of U2 with distomedial angle armed with comb of 3-4 robust setae; 7) U3 endopod as long as exp1; and 8) telson with robust setae on tip. The generic diagnosis is amended in order to allow the precise characterization of members of Psammogammarus compared to other eriopisids. PMID:26106715

  20. Caprellid assemblages (Crustacea: Amphipoda) in shallow waters invaded by Caulerpa racemosa var. cylindracea from southeastern Spain

    NASA Astrophysics Data System (ADS)

    Vázquez-Luis, M.; Guerra-García, J. M.; Sanchez-Jerez, P.; Bayle-Sempere, J. T.

    2009-06-01

    Growth of the invasive algae Caulerpa racemosa var. cylindracea in shallow habitats may influence the faunal assemblage composition. We studied its effects on caprellid assemblages associated with shallow-water habitats of hard and soft bottoms from the SE Iberian Peninsula (native rocky-bottom algae, C. racemosa from hard and soft bottoms, and Caulerpa prolifera, Cymodocea nodosa and Posidonia oceanica from soft bottoms). Samples were taken in two different sampling periods (September 2004 and March 2005). A total of seven caprellid species were identified, with important differences in their distribution in different habitats. Total abundance of caprellids was very high in March on native algae on hard bottoms, and on C. racemosa on both soft and hard bottoms. On both hard and soft bottoms, abundances of Caprella hirsuta recorded from C. racemosa were low. On the other hand, a higher abundance of other species, namely C. acanthifera, C. santosrosai, Phtisica marina and Pseudoprotella phasma, was recorded from C. racemosa. The results indicate that C. racemosa may have a positive influence on some caprellid species, while seasonal changes are also evident. It is concluded that introduced C. racemosa may serve as a new habitat, promoting and maintaining caprellid populations in shallow Mediterranean habitats.

  1. Ingolfiellamaldivensis sp. n. (Crustacea, Amphipoda, Ingolfiellidae) from coral reef sand off Magoodhoo island, Maldives.

    PubMed

    Vonk, Ronald; Jaume, Damiá

    2014-01-01

    A new species of marine interstitial wormshrimp, Ingolfiellamaldivensis, is described from coral sand on the inner and outer reef off Magoodhoo island, Faafu atoll, Maldives. Six females were found and compared to other species from the Maldives and those bordering the Indian Ocean and beyond. Morphological resemblance ties it to a species from the Caribbean island of Curaçao. Both species are found in shallow sublittoral interstitial spaces. PMID:25408614

  2. 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

  3. Diversity and zoogeography of Icelandic deep-sea Ampeliscidae (Crustacea: Amphipoda)

    NASA Astrophysics Data System (ADS)

    Dauvin, Jean-Claude; Alizier, Sandrine; Weppe, Adeline; Guðmundsson, Guðmundur

    2012-10-01

    A large collection of ampeliscids (15,454 specimens from 366 sampling sites) from Icelandic waters was identified to species and distributional patterns analysed. The specimens were sampled during the BIOICE programme, the main objective of which was to map the invertebrate species diversity within the Icelandic economical zone (758,000 km2). Nineteen species were identified: ten Ampelisca (8018 specimens), six Byblis (4887 specimens), three Haploops (1673 specimens), plus a complex of Haploops spp. (876 specimens). Four of these 19 species are new records for Icelandic waters: A. dalmatina Karaman, 1975 was previously known around the Faroe Islands; B. abyssi Sars, 1879 and B. affinis Sars, 1879 were known from the NE Atlantic and B. medialisMills (1971) from the NW Atlantic. The three most abundant species were B. minuticornis Sars, 1879, B. gaimardi (Kröyer, 1846) and A. uncinata Chevreux, 1887, while the three most frequently occurring species at all stations were H. setosa Boeck, 1871, A. uncinata and A. macrocephala Lilljeborg, 1852. Species were grouped according to three geographical patterns: northern species (six species), southern species (nine species) and circum-Icelandic species (four species). The species were also grouped according to three depth categories: nine species were confined to the continental shelf and the upper part of the continental slopes around Iceland; nine species had a wide bathymetric range and one species (A. islandica) occurred only in deep waters. Factors related to water depth exerted the main influence on ampeliscid distribution patterns around Iceland. A comparison of the Icelandic Ampeliscidae fauna with five areas of the North Atlantic Ocean showed a strong similarity to the fauna of Faroe Islands and a lesser similarity to the NW Atlantic fauna.

  4. A new species of Spelaeogammarus (Amphipoda: Bogidielloidea: Artesiidae) with an identification key for the genus.

    PubMed

    Bastos-Pereira, Rafaela; Ferreira, Rodrigo L

    2015-01-01

    There are five described species of the cave-dwelling amphipods of the genus Spelaeogammarus, all of them inhabiting caves on the Brazilian state of Bahia. A new species of this genus is here described, which is closely related to the already known species S. santanensis and S. titan. Spelaeogammarus sanctus sp. nov. differs from its congeneric species basically by the presence of more than 18 bifid setae on the dorsal margin of uropod 3 outer ramus and telson with one apical and two subapical stout setae, while the other species generally present less setae on the third uropod and more setae on telson. An identification key and an updated table of the Spelaeogammarus species diagnosis are provided, as well as a multivariate statistical approach of morphological variations among the species. PMID:26624139

  5. [Lipids in the amphipod Talorchestia margaritae (Amphipoda: Talitridae) and its relationship with the ecology of the species].

    PubMed

    López, Sandra; Díaz, Yusbelly; Noris, Karem; Cabrera, Aivle

    2010-09-01

    T. margaritae, an endemic species inhabiting Venezuelan coasts, plays an important ecological role in plant and animal decomposition. To understand this issue in some animal groups, especially small ones, lipid composition analysis has been an interesting tool to describe their trophic relationships and food preferences. In order to assess this and visualize the components of their diet, we determined the lipid composition differences between males and females and among age classes in this species. Two sandy beaches were selected: Mangle Quemao and Las Mercedes de Paparo, from which sand samples of known volume were collected at the supralittoral area in 2007. Organisms were separated by age and sex classes, and their size, weight, density, biomass, total lipids (TL), lipid classes and fatty acid markers present in their tissues were determined. The sizes were similar for all age classes between the two locations, while the weights were higher for Mangle Quemao. The TL and lipid classes showed similar proportions between sexes, age classes and locations (TL: 3-5%; Phospholipids: 20-30%; Glycolipids: <1%; sterols: 4%). On the other hand, Triglycerides (TAG) were higher in Mangle Quemao, which may be related to the difference between the weights of two locations. The most abundant fatty acid biomarkers in the two studied sites were 16:0 and 18:1(n-9); this last one is characteristic of a carnivorous diet. The other nine markers were identified with changes in their distribution in organisms at Mangle Quemao and between males and females of both populations. Based on observed fatty acids markers we can assume T. margaritae as a generalist carnivore. Those populations were influenced by available food; inducing differences in weight, TAG proportion and markers diversity. PMID:20737842

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

    PubMed

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

    2010-05-01

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

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

    PubMed

    Thomas, James Darwin

    2015-01-01

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

  8. Behaviour of Talitrus saltator (Crustacea: Amphipoda) on a rehabilitated sandy beach on the European Atlantic Coast (Portugal)

    NASA Astrophysics Data System (ADS)

    Bessa, Filipa; Rossano, Claudia; Nourisson, Delphine; Gambineri, Simone; Marques, João Carlos; Scapini, Felicita

    2013-01-01

    Environmental and human controls are widely accepted as the main structuring forces of the macrofauna communities on sandy beaches. A population of the talitrid amphipod Talitrus saltator (Montagu, 1808) was investigated on an exposed sandy beach on the Atlantic coast of Portugal (Leirosa beach) to estimate orientation capabilities and endogenous rhythms in conditions of recent changes in the landscape (artificial reconstruction of the foredune) and beach morphodynamics (stabilization against erosion from the sea). We tested sun orientation of talitrids on the beach and recorded their locomotor activity rhythms under constant conditions in the laboratory. The orientation data were analysed with circular statistics and multiple regression models adapted to angular distributions, to highlight the main factors and variables influencing the variation of orientation. The talitrids used the sun compass, visual cues (landscape and sun visibility) to orient and the precision of orientation varied according to the tidal regime (rising or ebbing tides). A well-defined free-running rhythm (circadian with in addition a bimodal rhythmicity, likely tidal) was highlighted in this population. This showed a stable behavioural adaptation on a beach that has experienced a process of artificial stabilization of the dune through nourishment actions over a decade. Monitoring the conditions of such dynamic environments and the resilience capacity of the inhabiting macroinfauna is a main challenge for sandy beach ecologists.

  9. Uptake, Accumulation and Excretion by Corophium volutator(Crustacea: Amphipoda) of Zinc, Cadmium and Cobalt Added to Sewage Sludge

    NASA Astrophysics Data System (ADS)

    Burgos, M. Galay; Rainbow, P. S.

    1998-11-01

    Zinc, cadmium and cobalt associated with digested sewage sludge are available to the benthic deposit-feeding amphipodCorophium volutator(Pallas). Accumulation by the amphipod of radioactively labelled metals adsorbed onto a 5% sludge-sediment mixture increased with time of exposure up to 15 days, but irregularly so as pulses of labelled metal were excreted into faecal pellets. The three labelled metals were accumulated and excreted apparently almost synchronously by individual amphipods, although great variability between different individuals was found. This intraspecific variability could not be attributed to differences between male and female amphipods. Net accumulation of labelled metals from the sludge increased with increased labelled metal concentration in the sludge, but not with time beyond an initial period of 15-30 days. It is proposed that the metal excretion patterns might reflect the breakdown of epithelial cells of the ventral caeca following a cell cycle, releasing accumulated stores of detoxified metals into the gut lumen and out of the body through faeces.

  10. Population structure of resident, immigrant, and swimming Corophium volutator (Amphipoda) on an intertidal mudflat in the Bay of Fundy, Canada

    NASA Astrophysics Data System (ADS)

    Drolet, David; Barbeau, Myriam A.

    2012-05-01

    Spatial variation in biotic and abiotic conditions, and differences in dispersive behavior of different life history stages can result in the formation of zones with different demography for infaunal and epifaunal species within vast intertidal flats. In this study, we evaluated within-mudflat homogeneity of the infaunal amphipod Corophium volutator found in the mud (residents), colonizing artificially disturbed areas (immigrants), and caught in the water column (swimmers) on a large mudflat in the upper Bay of Fundy, Canada. Densities of residents, immigrants, and swimmers were well structured in space (both along and across shore). Occasionally, significant differences in size structure, sex ratio, and proportion of ovigerous females were found at different intertidal levels, but these were short-lived. Comparisons of size and sex structure of residents, immigrants, and swimmers revealed occasional marked differences, with small juveniles and large adult males moving most. However, this size-bias in movement did not translate into zones with different population dynamics, suggesting that ample dispersal, through swimming and drifting in the water column, homogenized the population and masked potential effects of variation in environmental conditions. We therefore conclude that the mudflat represents one homogeneous population.

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

    PubMed Central

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

    2016-01-01

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

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

    EPA Science Inventory

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

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

    PubMed Central

    Wongkamhaeng, Koraon; Nabhitabhata, Jaruwat; Towatana, Prawit

    2015-01-01

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

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

    PubMed Central

    Thomas, James Darwin

    2015-01-01

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

  15. A new species of Leucothoid Amphipod, Anamixis bananarama, sp. n., from Shallow Coral Reefs in French Polynesia (Crustacea, Amphipoda, Leucothoidae)

    PubMed Central

    James Darwin, Thomas; Krapp-Schickel, Traudl

    2011-01-01

    Abstract Both leucomorph and anamorph developmental stages of Anamixis bananarama sp. n., are illustrated and described from shallow back reef environments of Moorea, French Polynesia. Distinguished by vestigial first gnathopods that persist in post-transformational adult males, this is the second species in the genus to exhibit this unusual character. In other features such as coxae and second gnathopods Anamixis bananarama sp. n. resembles other Pacific Plate endemics of Anamixis known from the region. Specific host association is not documented but suspected to be small calcareous asconoid sponges associated with coral rubble. PMID:21594109

  16. 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. PMID:21086158

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

    PubMed

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

    2016-01-01

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

  18. Morphological and ontogenetic stratification of abyssal and hadal Eurythenes gryllus sensu lato (Amphipoda: Lysianassoidea) from the Peru-Chile Trench

    NASA Astrophysics Data System (ADS)

    Eustace, Ryan M.; Ritchie, Heather; Kilgallen, Niamh M.; Piertney, Stuart B.; Jamieson, Alan J.

    2016-03-01

    The globally ubiquitous lysianassoid amphipod, Eurythenes gryllus, has been shown to consist of multiple genetically distinct cryptic taxa, with depth considered a major driver of speciation and morphological divergence. Here we examine morphological variation of E. gryllus sensu lato through a continuous depth distribution that spans from abyssal (3000-6000 m) into hadal depths (>6000 m) in the Peru-Chile Trench (SE Pacific Ocean). Three distinct morphospecies were identified: one was confirmed as being E. magellanicus (4602-5329 m) based on DNA sequence and morphological similarity. The other two morphologically distinct species were named based upon depth of occurrence; Abyssal (4602-6173 m) and Hadal (6173-8074 m). The three Eurythenes morphospecies showed vertical ontogenetic stratification across their bathymetric range, where juveniles were found shallower in their depth range and mature females deeper. Potential ecological and evolutionary drivers that explain the observed patterns of intra and inter-specific structure, such as hydrostatic pressure and topographical isolation, are discussed.

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

    USGS Publications Warehouse

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

    2011-01-01

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

  20. The family Caprellidae (Amphipoda: Caprelloidea: Caprellidae) from Campos Basin, Southwestern Atlantic, with a key of species occurring in Brazil.

    PubMed

    Mauro, Fábio Da Motta; Serejo, Cristiana Silveira

    2015-01-01

    Caprellid material of the present study was collected between 25-3000 m depth from the Campos Basin area, Southwestern Atlantic. As a result, Deutella incerta was found as a new record to the Southwestern Atlantic and two new species are described: Liropus guerragarciai sp. nov. and Mayerella sittropiae sp. nov. Besides, Paracaprella pusilla is herein redescribed as a common component of the Campos Basin amphipod community. Caprellids are a diverse and abundant group that can be found among algae and general biological substrates of the continental shelf area. As more deep sea samples are coming into light, they are turning out to be also a common component in this habitat. Including the present data, there are 25 caprellid species recorded in Brazil, being four of them restricted to the slope areas and 14 endemic to the Brazilian coast. A key to the Caprellidae species from Brazil is provided. PMID:26623760

  1. A molecular gut content study of Themisto abyssorum (Amphipoda) from Arctic hydrothermal vent and cold seep systems.

    PubMed

    Olsen, Bernt Rydland; Troedsson, Christofer; Hadziavdic, Kenan; Pedersen, Rolf B; Rapp, Hans Tore

    2014-08-01

    The use of DNA as a marker for prey inside the gut of predators has been instrumental in further understanding of known and unknown interactions. Molecular approaches are in particular useful in unavailable environments like the deep sea. Trophic interactions in the deep sea are difficult to observe in situ, correct deep-sea experimental laboratory conditions are difficult to obtain, animals rarely survive the sampling, or the study organisms feed during the sampling due to long hauls. Preliminary studies of vent and seep systems in the Nordic Seas have identified the temperate-cold-water pelagic amphipod Themisto abyssorum as a potentially important predator in these chemosynthetic habitats. However, the prey of this deep-sea predator is poorly known, and we applied denaturing high performance liquid chromatography (DHPLC) to investigate the predator-prey interactions of T. abyssorum in deep-water vent and seep systems. Two deep-water hydrothermally active localities (The Jan Mayen and Loki's Castle vent fields) and one cold seep locality (The Håkon Mosby mud volcano) in the Nordic Seas were sampled, genomic DNA of the stomachs of T. abyssorum was extracted, and 18S rDNA gene was amplified and used to map the stomach content. We found a wide range of organisms including micro-eukaryotes, metazoans and detritus. Themisto abyssorum specimens from Loki's Castle had the highest diversity of prey. The wide range of prey items found suggests that T. abyssorum might be involved in more than one trophic level and should be regarded as an omnivore and not a strict carnivore as have previously been suggested. PMID:24172025

  2. 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. PMID:26800185

  3. Mitochondrial genome rearrangements at low taxonomic levels: three distinct mitogenome gene orders in the genus Pseudoniphargus (Crustacea: Amphipoda).

    PubMed

    Stokkan, Morten; Jurado-Rivera, Jose A; Juan, Carlos; Jaume, Damià; Pons, Joan

    2016-09-01

    A comparison of mitochondrial genomes of three species of the amphipod Pseudoniphargus revealed the occurrence of a surprisingly high level of gene rearrangement involving protein-coding genes that is a rare phenomenon at low taxonomic levels. The three Pseudoniphargus mitogenomes also display a unique gene arrangement with respect to either the presumed Pancrustacean order or those known for other amphipods. Relative long non-coding sequences appear adjacent to the putative breakage points involved in gene rearrangements of protein coding genes. Other details of the newly obtained mitochondrial genomes - e.g., gene content, nucleotide composition and codon usage - are similar to those found in the mitogenomes of other amphipod species studied. They all contain the typical mitochondrial genome set consisting of 13 protein-coding genes, 22 tRNAs, and two rRNAS, as well as a large control region. The secondary structures and characteristics of tRNA and ribosomal mitochondrial genes of these three species are also discussed. PMID:26329687

  4. Caprellidae (Crustacea: Peracarida: Amphipoda) from the Red Sea and Suez Canal, with the redescription of Metaprotella africana and Paradeutella multispinosa.

    PubMed

    Zeina, Amr F; Guerra-García, José M

    2016-01-01

    The Caprellidae from the Red Sea are reviewed based on the literature data and new collections from the Hurghada coasts. So far, only six valid species has been reported from the Red Sea and Suez Canal: Caprella equilibra Say, 1818, Hemiaegina minuta Mayer, 1890, Metaprotella africana Mayer, 1903, Paracaprella pusilla Mayer, 1890 and Paradeutella multispinosa Schellenberg, 1928 and Pseudocaprellina pambanensis Sundara Raj, 1927. The type material of M. africana (deposited in the Muséum nacional d'Histoire naturelle, Paris) and Paradeutella multispinosa (deposited in the Museum für Naturkunde, Berlin) are redescribed and illustrated in detail. P. pambanensis and H. minuta were the most abundant species in the collections along the northern coast. Most of the sampling effort has been focused on algae from shallow waters; additional substrates such as sediments, hydroids and coral rubble, especially from areas deeper than 15 meters should be explored. The number of caprellid species in the Red Sea is low compared to adjacent waters, as the Mediterranean Sea. However, further research and more extensive caprellid collections should be conducted along the coasts of Saudi Arabia, Yemen, Sudan and Eritrea, which are still unexplored. PMID:27394584

  5. First occurrence of Caprella scaura Templeton, 1836 (Crustacea: Amphipoda) on off-coast fish farm cages in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Fernandez-Gonzalez, V.; Sanchez-Jerez, P.

    2014-03-01

    The non-indigenous caprellid Caprella scaura Templeton, 1836, native to the western Indian Ocean, was firstly recorded in the Mediterranean Sea in 1994, and all Mediterranean populations discovered to date are related to shoreline areas. A total of ten fish farms were sampled off the coasts of Spain (4), Italy (1), Croatia (2), Greece (1) and Malta (2). This is the first time that C. scaura has been reported from off-coast areas. Reproducing populations have been detected in fouling communities of three tuna farms off the coast of Croatia and Malta, which also signifies the first confirmed record of this species in both countries. The occurrence of successfully established and thriving populations of C. scaura Templeton, 1836 at floating off-coast fish farms underlines the importance of these structures as stepping stones in the species.

  6. Redescription of two subterranean amphipods Niphargusmolnari Méhely, 1927 and Niphargusgebhardti Schellenberg, 1934 (Amphipoda, Niphargidae) and their phylogenetic position.

    PubMed

    Angyal, Dorottya; Balázs, Gergely; Zakšek, Valerija; Krízsik, Virág; Fišer, Cene

    2015-01-01

    A detailed redescription of two endemic, cave-dwelling niphargid species of the Hungarian Mecsek Mts., Niphargusmolnari Méhely, 1927 and Niphargusgebhardti Schellenberg, 1934 is given based on newly collected material. Morphology was studied under light microscopy and with scanning electon microscopy. Morphological descriptions are complemented with mitochondrial cytochrome c oxidase subunit I (COI) sequences as barcodes for both species and with notes on their ecology. Using three independent molecular markers we showed that Niphargusgebhardti belongs to the clade distributed between Central and Eastern Europe, whereas phylogenetic relationship of Niphargusmolnari to the rest of Niphargus species is not clear. The two species from the Mecsek Mts. are phylogenetically not closely related. Both species need to be treated as vulnerable according to IUCN Red List of Threatened Species. PMID:26175603

  7. 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

    2016-01-01

    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. PMID:27394471

  8. A new species of the genus Melita (Amphipoda, Hadzioidea, Melitidae) from anchialine pool on the Cozumel Island, NE Caribbean Sea.

    PubMed

    Ortiz, Manuel; Winfield, Ignacio

    2016-01-01

    A new species of genus Melita collected from anchialine pool (Cenote Aerolito) on Cozumel Island is described.  Distinctive characters of male of the new species include an accessory flagellum 4-articulate; palm of gnathopod 2 with long setae; urosomite 2 with two robust setae on right side, and one on left. Female of the new species differs by coxa 6 without lateral ridge at base of hook, and anteroventral angle without stridulating ridges on anteroventral process; gnathopods 1-2 covered with long setae on articles 5-6. The main morphological differences between males of Melita species recorded previously for the Gulf of Mexico and the Caribbean Sea and the new species are also given. PMID:27395742

  9. Genetic connectivity between land and sea: the case of the beachflea Orchestia montagui (Crustacea, Amphipoda, Talitridae) in the Mediterranean Sea

    PubMed Central

    2013-01-01

    Introduction We examined patterns of genetic divergence in 26 Mediterranean populations of the semi-terrestrial beachflea Orchestia montagui using mitochondrial (cytochrome oxidase subunit I), microsatellite (eight loci) and allozymic data. The species typically forms large populations within heaps of dead seagrass leaves stranded on beaches at the waterfront. We adopted a hierarchical geographic sampling to unravel population structure in a species living at the sea-land transition and, hence, likely subjected to dramatically contrasting forces. Results Mitochondrial DNA showed historical phylogeographic breaks among Adriatic, Ionian and the remaining basins (Tyrrhenian, Western and Eastern Mediterranean Sea) likely caused by the geological and climatic changes of the Pleistocene. Microsatellites (and to a lesser extent allozymes) detected a further subdivision between and within the Western Mediterranean and the Tyrrhenian Sea due to present-day processes. A pattern of isolation by distance was not detected in any of the analyzed data set. Conclusions We conclude that the population structure of O. montagui is the result of the interplay of two contrasting forces that act on the species population genetic structure. On one hand, the species semi-terrestrial life style would tend to determine the onset of local differences. On the other hand, these differences are partially counter-balanced by passive movements of migrants via rafting on heaps of dead seagrass leaves across sites by sea surface currents. Approximate Bayesian Computations support dispersal at sea as prevalent over terrestrial regionalism. PMID:23618554

  10. Comparison of the biology, dynamics, and secondary production of Talorchestia brito (Amphipoda, Talitridae) in Atlantic (Portugal) and Mediterranean (Tunisia) populations

    NASA Astrophysics Data System (ADS)

    Gonçalves, S. C.; Marques, J. C.; Pardal, M. A.; Bouslama, M. F.; El Gtari, M.; Charfi-Cheikhrouha, F.

    2003-12-01

    The biology, population dynamics, and production of Talorchestia brito were studied at two sandy beaches located on the Atlantic (Portugal) and on the Mediterranean (Tunisia) coasts, respectively. The seasonal variation in abundance and the overall densities were similar in both populations. Reproduction occurred from February to September in the Atlantic, and from March to early November in the Mediterranean. The sex ratio was male biased in the Atlantic, and female biased in the Mediterranean. Based on data from the Atlantic population, both abundance and the proportion of reproductive females were positively correlated with temperature, while the proportion of juveniles in the population was positively correlated with temperature and sediment moisture. On average, individuals from the Atlantic were larger than the ones from the Mediterranean. Life span was estimated at six to nine months in the Atlantic, and five to eight months in the Mediterranean. Talorchestia brito was shown to be a semiannual species, with iteroparous females producing two broods per year, and exhibited a bivoltine life cycle. The minimum age required for males' and females' sexual differentiation and for female sexual maturation was shorter in the Mediterranean. Growth production ( P) was estimated at 0.19 g m -2 y -1 ash free dry weight (AFDW; 4.3 kJ m -2 y -1) in the Atlantic population, and 0.217 g m -2 y -1 AFDW (4.9 kJ m -2 y -1) in the Mediterranean one. Elimination production ( E) was estimated at 0.35 g m -2 y -1 AFDW (7.9 kJ m -2 y -1) in the Atlantic, and 0.28 g m -2 y -1 AFDW (6.3 kJ m -2 y -1) in the Mediterranean. The average annual biomass ( overlineB) (standing stock) was estimated at 0.032 g m -2 in the Atlantic beach, and 0.029 g m -2 in the Mediterranean one, resulting, respectively, in P/ overlineB ratios of 5.9 and 7.5 and E/ overlineB ratios of 10.8 and 9.6. Like other talitrids, T. brito exhibited geographic variation in morphometrical characteristics, sex ratio, growth rates, life span, and reproduction period, with the Atlantic population presenting a slower life history.

  11. DNA barcoding reveals new insights into the diversity of Antarctic species of Orchomene sensu lato (Crustacea: Amphipoda: Lysianassoidea)

    NASA Astrophysics Data System (ADS)

    Havermans, C.; Nagy, Z. T.; Sonet, G.; De Broyer, C.; Martin, P.

    2011-03-01

    Recent molecular analyses revealed that several so-called "circum-Antarctic" benthic crustacean species appeared to be complexes of cryptic species with restricted distributions. In this study we used a DNA barcoding approach based on mitochondrial cytochrome oxidase I gene sequences in order to detect possible cryptic diversity and to test the circumpolarity of some lysianassoid species. The orchomenid genus complex consists of the genera Abyssorchomene, Falklandia, Orchomenella, Orchomenyx and Pseudorchomene. Species of this genus complex are found throughout the Southern Ocean and show a high species richness and level of endemism. In the majority of the studied species, a genetic homogeneity was found even among specimens from remote sampling sites, which indicates a possible circum-Antarctic and eurybathic distribution. In four investigated species ( Orchomenella ( Orchomenopsis) acanthurus, Orchomenella ( Orchomenopsis) cavimanus, Orchomenella ( Orchomenella) franklini and Orchomenella ( Orchomenella) pinguides), genetically divergent lineages and possible cryptic taxa were revealed. After a detailed morphological analysis, O. ( O.) pinguides appeared to be composed of two distinct species, formerly synonymized under O. ( O.) pinguides. The different genetic patterns observed in these orchomenid species might be explained by the evolutionary histories undergone by these species and by their different dispersal and gene flow capacities.

  12. High genetic diversity and variability of bacterial communities associated with the sandhopper Talitrus saltator (Montagu) (Crustacea, Amphipoda)

    NASA Astrophysics Data System (ADS)

    Mengoni, A.; Focardi, A.; Bacci, G.; Ugolini, A.

    2013-10-01

    The microbiome present in individuals of Talitrus saltator belonging to seven populations distributed along the Tuscan coast (Italy) was assessed by using Terminal-Restriction Fragment Length Polymorphism (T-RFLP) analysis of amplified 16S rRNA genes. Talitrus saltator is one of the key species of the damp band of European sandy beaches and despite of the large interest on animal-associated bacteria, only a few and preliminary data were present. Results showed a high diversity of the microbiome, composed mainly by members of Alphaproteobacteria, Gammaproteobacteria, Bacillales and Clostridiales classes. The microbiome fingerprints were highly variable among individuals, even from the same populations, the inter-individual differences accounting for 88.7% of total fingerprint variance. However, statistically significant population-specific microbiome signatures were detected, and accounted for the remaining 11.3% of total fingerprint variance. These population-specific differences were mainly attributed to sequences from members of known host-associated bacteria such as Gammaproteobacteria and Betaproteobacteria, Cytophagia and Spirochaetia. This study showed the high complexity of the microbiome associated with an amphipod species and on the inter-individual microbiome variation with potential importance for understanding amphipod trophic and ecologic processes.

  13. A new species of the rare genus Priscomilitaris from the Seto Inland Sea, Japan (Crustacea, Amphipoda, Priscomilitaridae)

    PubMed Central

    Tomikawa, Ko; Tanaka, Hayato; Nakano, Takafumi

    2016-01-01

    Abstract A new species of the priscomilitarid amphipod, Priscomilitaris heike, from the Seto Inland Sea, Japan, is named and described. This new species is the third species of Priscomilitaridae and the second species of Priscomilitaris. Additionally, nucleotide sequences of nuclear 28S rRNA and histone H3 as well as mitochondrial cytochrome c oxidase subunit I from its holotype were determined. Priscomilitaris heike sp. n. is distinguished from its congener, Priscomilitaris tenuis Hirayama, 1988, by having deep antennal sinus, long flagellar article 1 of antennae 1 and 2, long mandibular palp article 2, 10 robust setae on outer ramus of maxilla 1, and rounded epimeral plates. A key to the species of Proscomilitaridae is provided. PMID:27551228

  14. A new species of the rare genus Priscomilitaris from the Seto Inland Sea, Japan (Crustacea, Amphipoda, Priscomilitaridae).

    PubMed

    Tomikawa, Ko; Tanaka, Hayato; Nakano, Takafumi

    2016-01-01

    A new species of the priscomilitarid amphipod, Priscomilitaris heike, from the Seto Inland Sea, Japan, is named and described. This new species is the third species of Priscomilitaridae and the second species of Priscomilitaris. Additionally, nucleotide sequences of nuclear 28S rRNA and histone H3 as well as mitochondrial cytochrome c oxidase subunit I from its holotype were determined. Priscomilitaris heike sp. n. is distinguished from its congener, Priscomilitaris tenuis Hirayama, 1988, by having deep antennal sinus, long flagellar article 1 of antennae 1 and 2, long mandibular palp article 2, 10 robust setae on outer ramus of maxilla 1, and rounded epimeral plates. A key to the species of Proscomilitaridae is provided. PMID:27551228

  15. Exploring trophic strategies of exotic caprellids (Crustacea: Amphipoda): Comparison between habitat types and native vs introduced distribution ranges

    NASA Astrophysics Data System (ADS)

    Ros, Macarena; Tierno de Figueroa, José Manuel; Guerra-García, José Manuel; Navarro-Barranco, Carlos; Lacerda, Mariana Baptista; Vázquez-Luis, Maite; Masunari, Setuko

    2014-02-01

    The trophic ecology of non-native species is a key aspect to understand their invasion success and the community effects. Despite the important role of caprellid amphipods as trophic intermediates between primary producers and higher levels of marine food webs, there is very little information on their feeding habits. This is the first comprehensive study on the trophic strategies of two co-occurring introduced caprellids in the Spanish coasts: Caprella scaura and Paracaprella pusilla. The diet of 446 specimens of C. scaura and 230 of P. pusilla was analyzed to investigate whether there were differences in the feeding habits in relation to habitat characteristics (natural vs artificial hard substrata), type of host substrata (bryozoans and hydroids) and native vs introduced distribution ranges (Brazil vs Spain). Results revealed differences in diet preferences of the two species that have important implications for their trophic behaviour and showed a limited food overlap, which may favour their coexistence in introduced areas. In general terms, P. pusilla is a predator species, showing preference by crustacean prey in all of its life stages, while C. scaura feeds mainly on detritus. Although no sex-related diet shifts were observed in either of the species, evidence of ontogenetic variation in diet of C. scaura was found, with juveniles feeding on more amount of prey than adults. No diet differences were found between native and introduced populations within the same habitat type. However, P. pusilla exhibited a shift in its diet when different habitats were compared in the same distribution area, and C. scaura showed a flexible feeding behaviour between different host substrata in the same habitat type. This study shows that habitat characteristics at different scales can have greater influence on the feeding ecology of exotic species than different distribution ranges, and support the hypothesis that a switch between feeding strategies depending on habitat characteristics could favour invasion success.

  16. Redescription of two subterranean amphipods Niphargus molnari Méhely, 1927 and Niphargus gebhardti Schellenberg, 1934 (Amphipoda, Niphargidae) and their phylogenetic position

    PubMed Central

    Angyal, Dorottya; Balázs, Gergely; Zakšek, Valerija; Krízsik, Virág; Fišer, Cene

    2015-01-01

    Abstract A detailed redescription of two endemic, cave-dwelling niphargid species of the Hungarian Mecsek Mts., Niphargus molnari Méhely, 1927 and Niphargus gebhardti Schellenberg, 1934 is given based on newly collected material. Morphology was studied under light microscopy and with scanning electon microscopy. Morphological descriptions are complemented with mitochondrial cytochrome c oxidase subunit I (COI) sequences as barcodes for both species and with notes on their ecology. Using three independent molecular markers we showed that Niphargus gebhardti belongs to the clade distributed between Central and Eastern Europe, whereas phylogenetic relationship of Niphargus molnari to the rest of Niphargus species is not clear. The two species from the Mecsek Mts. are phylogenetically not closely related. Both species need to be treated as vulnerable according to IUCN Red List of Threatened Species. PMID:26175603

  17. Environmental factors modulating the extent of impact in coastal invasions: The case of a widespread invasive caprellid (Crustacea: Amphipoda) in the Iberian Peninsula.

    PubMed

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

    2015-09-15

    Understanding the respective roles of environment and interspecific interactions in shaping species' distributions is a critical aspect in determining the potential impacts of newcomer species on occupied habitats. The invasive caprellid amphipod Caprella scaura has successfully spread along southern Europe in a short time period, coinciding with a decline in the population of an ecologically similar congener, Caprella equilibra. To understand the mechanisms underlying the establishment success of this aggressive species and its potential role in shaping C. equilibra's distribution, we analyze the biotic and abiotic factors involved in the patterns of distribution and co-occurrence of both species along the Iberian Peninsula and northern Africa. Our analyses support that C. scaura is competitively displacing C. equilibra from the study area, but also point out the critical role of salinity and temperature in modulating this interaction and limiting the invasive success of C. scaura on the Iberian North-Atlantic coast. PMID:26140750

  18. A new species of Boca Lowry & Stoddart, 1997 (Amphipoda: Lysianassoidea: Aristiidae) from a mesophotic coral ecosystem off Puerto Rico, Caribbean Sea.

    PubMed

    Senna, André R; Sorrentino, Rayane; Chatterjee, Tapas; Schizas, Nikolaos V

    2014-01-01

    A new species of the genus Boca Lowry & Stoddart, 1997 is described from a mesophotic coral ecosystem off southwestern Puerto Rico, in the Caribbean Sea. The new species is easily recognized from the others in the genus mainly by the following characters: (1) maxilliped, inner plate with 2 long apical simple setae; palp, articles slender, subequal in length; (2) gnathopod 1, propodus slightly elongate, about 2.5 × longer than wide, and palm extremely acute, quite long and distinctly demarked by a robust seta at the palmar corner; (3) gnathopod 2, carpus slightly elongate, about 3.7 × longer than wide; (4) pereopod 5, basis widely expanded posteriorly, posterior margin rounded and smooth, and posteroventral lobe weakly developed. We also present a key to world species of Boca. This is the fifth species of Boca from world's oceans and the first record of the genus from Puerto Rico. PMID:25543800

  19. Description of new endemic species of the genus Niphargus Schiödte, 1849 (Amphipoda: Niphargidae) from a karst spring in Zagros Mountains in Iran.

    PubMed

    Esmaeili-Rineh, Somayeh; Heidari, Firoozeh; Fišer, Cene; Akmali, Vahid

    2016-01-01

    New species of the genus Niphargus is described and named as N. kermanshahi sp. nov. from a karst spring in west of Iran. This species is identified based on the analysis of morphological characters and 28S ribosomal DNA sequences. Taxonomic status and phylogenetic position of this species is discussed in comparison to other Iranian species of Niphargus genus. PMID:27395592

  20. A reassessment of the phylogenetic utility of genus-level morphological characters in the family Bogidiellidae (Crustacea, Amphipoda), with description of a new species of Eobogidiella Karaman, 1981

    PubMed Central

    Sidorov, Dmitry A.; Katz, Aron D.; Taylor, Steven J.; Chertoprud, Mikhail V.

    2016-01-01

    Abstract Bogidiellidae is the most diverse and cosmopolitan family of stygobiotic amphipods, and inhabits a variety of subterranean biotopes, especially interstitial habitats. While the family is characterized by considerable sexual dimorphism, this dimorphism has adversely affected our understanding of the systematics of the group. Most species have restricted geographic ranges and occur in difficult to sample habitats, so it is common for individual species descriptions to be based on a single sex. In this work we revisit an analysis of morphological characters in an attempt to clarify their phylogenetic utility in resolving taxonomic relationships among genera by introducing a new species, two additional characters, and phylogenetic statistical support values. Eobogidiella venkataramani sp. n., from a spring fed brook in the Shirawati River basin along the escarpment of the Western Ghats (Karnataka, India) differs from the only known congener, Eobogidiella purmamarcensis, from Argentina, in the structure of mouthparts, the shape and ornamentation on gnathopods and characters of the telson. Our phylogenetic analyses indicate that the available morphological characters are not sufficient to resolve phylogenetic relationships within Bogidiellidae, thus these characters alone cannot be used to determine the phylogenetic placement of Eobogidiella venkataramani sp. n. within the family. Nevertheless, Eobogidiella venkataramani sp. n. shares diagnostic characters with Eobogidiella, supporting placement of the new species in this genus. Our findings point towards a critical need to resolve relationships within the family using molecular approaches, along with the development of a suite of additional morphological characters for Bogidiellidae. This is the third species of Bogidiellidae from southern India. PMID:27587976

  1. New genera, species and records of Maeridae from Australian Waters:
    Austromaera, Ceradocus, Glossomaera, Hamimaera, Huonella gen. nov.,
    Linguimaera and Maeraceterus gen. nov. (Crustacea: Amphipoda).

    PubMed

    Hughes, Lauren E

    2016-01-01

    Thirty species of Maeridae are reported for Australian waters including the description of two new genera and nine new species. The new genus Huonella from southern Tasmanian seamounts is distinguished among the maerids by characters on the uropod 3, including elongation of both rami, inner ramus half the length of the outer ramus and outer ramus two articulate. The new genus Maeraceterus is establish for two new species, M. bramblensis from Western Australia and M. taaroa from Norfolk Island, which have a near transverse gnathopod 1 propodus palm and symmetrical male gnathopod 2. The new species Ceradocus baudini, Hamimaera thijsseni, Linguimaera boeckoides, L. daveyi, L. everardensis and L. mere are described here in. Additional distribution records are provided for eleven known Ceradocus and seven known Linguimaera, as well as three known maerids Austromaera mastersii (Haswell, 1879a), Glossomaera octodens (Sivaprakasam, 1969) and Hamimaera hamigera (Haswell, 1879b). Collections reported on here include material from Australia; Cocos (Keeling) and Christmas Islands, Indian Ocean; the Torres Strait; Papua New Guinea, Bismarck Sea and Norfolk Island, South Pacific. Keys to Ceradocus and Linguimaera sensu lato species in Australian waters are provided. PMID:27395154

  2. Diel Variation of Visual Response in Talitrus saltator and Talorchestia deshayesii (Crustacea: Amphipoda) from High Latitude Beaches of Low Tidal Amplitude

    NASA Astrophysics Data System (ADS)

    Nardi, M.; Persson, L.-E.; Scapini, F.

    2000-03-01

    The responses to a white directional light and a black stripe covering 60° of the horizon were studied in two Swedish populations of the amphipod species Talitrus saltator (Montagu, 1808) and Talorchesia deshayesii (Audoin, 1826) from two beaches on the southern Baltic Sea. Adult individuals were caught in the field and tested in constant laboratory conditions in order to investigate the possible variation of the responses during the 24 h cycle, and then to compare their behaviour with that of the Atlantic and Mediterranean populations, already known in literature. Previous studies explained the observed differences between Atlantic and Mediterranean populations with the differences in tidal excursions and did not take into account the different climatic conditions. The Baltic coasts, like those of the Italian Mediterranean, are not tidal and present prevalent low mean temperatures and high humidity throughout the year like those of Britain. The response to the artificial white light remained photopositive throughout the 24 h cycle in both the species sampled, although its intensity was lower during the day than at night in Talitrus saltator. The response to the black stripe showed an inversion from positive to negative during the 24 h cycle, the animals being directed towards the black stripe during the day and away from it at night; this response was more intense and clear cut in Talorchestia deshayesii than in Talitrus saltator . The pattern of response to the black stripe shown by the Swedish talitrids, differed from both that of the British and Italian populations, and was interpreted as a basic response related to the diel rhythm of emergence and burrowing.

  3. Coastal Talitridae (Amphipoda: Talitroidea) from north-western Australia to Darwin with a revision of the genus Cochinorchestia Lowry & Peart, 2010.

    PubMed

    Lowry, J K; Springthorpe, R T

    2015-01-01

    Three species of coastal talitrids are reported from north-western Western Australia: Australorchestia tantabiddyensis sp. nov., from Tantabiddy Rockholes Cave, Cape Range National Park; Talorchestia dampieri sp. nov. from Roebuck Bay, Broome and Cygnet Bay, King Sound; and Tropicorchestia derbyensis gen. et sp. nov. from Derby, King Sound. Five species are reported from west of Darwin, Northern Territory: Cochinorchestia lindsayae sp. nov.; Cochinorchestia metcalfeae sp. nov.; Floresorchestia limicola (Haswell, 1880); Microrchestia ntensis sp. nov.; and Tropicorchestia glasbyi sp. nov. The genus Cochinorchestia Lowry & Peart, 2010 is revised: Orchestia notabilis of Griffiths, 1973 is assigned to the new species Cochinorchestia morrumbene sp. nov. from Mozambique; Orchestia sp. of Ledoyer, 1979 is assigned to the new species Cochinorchestia poka sp. nov. from Ambon, eastern Indonesia; and Orchestia notabilis of Ledoyer 1986 is assigned to the new species Cochinorchestia tulear sp. nov. from south-western Madagascar. Microrchestia sp. of Bussarawich 1985 appears to be an undescribed species of Cochinorchestia from Thailand. We introduce the term virgula dentata to describe the highly modified tip of antenna 2 in talitrid amphipods and propose a theory for the age and current distribution of the family. PMID:26250029

  4. Life History and Production of the Western Gray Whale’s Prey, Ampelisca eschrichtii Krøyer, 1842 (Amphipoda, Ampeliscidae)

    PubMed Central

    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. PMID:26800185

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

    PubMed

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

    2015-01-01

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

  6. A new Ingolfiellid (Crustacea, Amphipoda, Ingolfiellidae) from an anchialine pool on Abd al Kuri Island, Socotra Archipelago, Yemen.

    PubMed

    Iannilli, Valentina; Vonk, Ronald

    2013-01-01

    Ingolfiella arganoi sp. n. from Abd al Kuri Island in the Arabian Sea is described from two specimens, a male and a female. The western shore of the Indian Ocean was hitherto a vacant spot in the distribution of circumtropical shallow marine interstitial ingolfiellids and therefore the location of the new species fills a meaningful gap in the geography of the family. Morphologically, the new species shows close affinities with Ingolfiella xarifae from the Maldives. PMID:23794897

  7. A new Ingolfiellid (Crustacea, Amphipoda, Ingolfiellidae) from an anchialine pool on Abd al Kuri Island, Socotra Archipelago, Yemen

    PubMed Central

    Iannilli, Valentina; Vonk, Ronald

    2013-01-01

    Abstract Ingolfiella arganoi sp. n. from Abd al Kuri Island in the Arabian Sea is described from two specimens, a male and a female. The western shore of the Indian Ocean was hitherto a vacant spot in the distribution of circumtropical shallow marine interstitial ingolfiellids and therefore the location of the new species fills a meaningful gap in the geography of the family. Morphologically, the new species shows close affinities with Ingolfiella xarifae from the Maldives. PMID:23794897

  8. Long-distance dispersal, low connectivity and molecular evidence of a new cryptic species in the obligate rafter Caprella andreae Mayer, 1890 (Crustacea: Amphipoda: Caprellidae)

    NASA Astrophysics Data System (ADS)

    Cabezas, M. Pilar; Navarro-Barranco, Carlos; Ros, Macarena; Guerra-García, José Manuel

    2013-09-01

    The amphipod Caprella andreae Mayer, 1890 was recorded for the first time in Southern Iberian Peninsula (36°44'15″N, 3°59'38″W). This species is the only obligate rafter of the suborder Caprellidea and has been reported to attach not only to floating objects such as ropes or driftwoods but also to turtle carapaces. Mitochondrial and nuclear markers were used to examine dispersal capabilities and population genetic structure of C. andreae across seven localities in the Mediterranean and Atlantic Ocean collected from floating substrata with different dispersal patterns. The strong population differentiation with no haplotypes shared between populations suggests that C. andreae is quite faithful to the substratum on which it settles. In addition, the proportionally higher genetic diversity displayed in populations living on turtles as well as the presence of highly differentiated haplotypes in the same turtle population may be indicative that these populations survive longer, which could lead C. andreae to prefer turtles instead of floating objects to settle and disperse. Therefore, rafting on floating objects may be sporadic, and ocean currents would not be the most important factor shaping patterns of connectivity and population structure in this species. Furthermore, molecular phylogenetic analyses revealed the existence of a cryptic species whose estimates of genetic divergence are higher than those estimated between C. andreae and other congeneric species (e.g. Caprella dilatata and Caprella penantis). Discovery of cryptic species among widely distributed small marine invertebrates is quite common and, in this case, prompts for a more detailed phylogenetic analysis and taxonomic revision of genus Caprella. On the other hand, this study also means the first record of the gammarids Jassa cadetta and Elasmopus brasiliensis and the caprellid Caprella hirsuta on drifting objects.

  9. Elasmopus thalyae sp. nov. (Crustacea: Amphipoda: Maeridae), a new benthic species from soft and hard bottoms of Arcachon Bay (SE Bay of Biscay).

    PubMed

    Gouillieux, Benoit; Sorbe, Jean Claude

    2015-01-01

    A new species of Elasmopus is described and figured from specimens collected in different benthic communities of Arcachon Bay. It can be distinguished from its closest relative E. rapax by the palmar ornamentation of male gnathopod 2 propodus (shelf and 2 teeth). It preferentially lives on hard bottoms (in mussel fouling of navigation buoys, Sabellaria spinulosa reefs, algal rocky bottoms, Laminaria and Saccorhiza bulbs and as epibiont on the carapace of Maja brachydactyla) but also less abundantly on naked sandy bottoms. An identification key of Atlantic and Mediterranean European species is also given. PMID:25661024

  10. New genus and new species of Caprellidae (Crustacea: Peracarida: Amphipoda) from the mesophotic coral ecosystems of Puerto Rico and St. Croix, Caribbean Sea.

    PubMed

    Guerra-García, José M; Chatterjee, Tapas; Schizas, Nikolaos V

    2015-01-01

    A new genus and two new species are described based on material collected from the mesophotic coral ecosystems of the U.S. Caribbean. The new genus Borikenella can be distinguished from other related genera such as Pseudaeginella, Paradeutella, Aciconula and Deutella by the combination of the following characters: pereopods 3 and 4 three-articulate, pereopods 5-7 six-articulate, mandible molar present, palp of the mandible with a setal formula 1-x-0, abdomen without appendages. The new species Liropus gurui, can be distinguished from the closely related L. japonicus mainly by the lack of anteroventral margin extended forward in pereonite 3, the lack of cleft and serration in the propodus of gnathopod 2, the longer pereopod 3 and the larger abdominal appendages. PMID:26624029

  11. The influence of environmental factors on the population dynamics, reproductive biology and productivity of Echinogammarus marinus Leach (Amphipoda, Gammaridae) in the Mondego estuary (Portugal)

    NASA Astrophysics Data System (ADS)

    Maranhão, Paulo; Bengala, Nuno; Pardal, Miguel; Marques, João Carlos

    2001-06-01

    The population density of Echinogammarus marinus in the Mondego estuary changed throughout the year, with a maximum during spring. The lowest densities were found in the north arm of the estuary, and the highest ones in the inner areas of the south arm. Higher densities appeared associated with the presence of muddy deposits under Fucus vesiculosus (Phaeophyta) and also with the presence of green macroalgae biomass over the sediments. Females were morphologically recognisable at smaller sizes than males, but males became larger than females. Fecundity increases with the size of females and is influenced by temperature and salinity. Sexual activity and recruitment take place continuously throughout the year, although it almost ceases by the end of winter. Present results are in opposition to the hypothesis of discontinuous recruitment presented in a previous study. Productivity (ash free dry weight- AFDW) was estimated at 1.74 to 2.45 g·m -2·year -1 in the north arm of the estuary corresponding to an annual turnover ratio ( P/ B¯) of 4.14 to 6.18. In the south arm, productivity was estimated at 1.96 to 2.74 g AFDW·m -2·year -1 in the middle section ( P/ B¯ of 4.68 to 6.56), and at 3.85 to 5.38 g AFDW·m -2·year -1 in the innermost sampling area ( P/ B¯ of 4.54 to 6.36). Differences in productivity appeared to depend only on population density, while annual P/ B¯ ratios were similar over the estuary. Evidence was found that several features of E. marinus population dynamics were dependent on environmental factors resulting from the particular estuary hydraulic regime.

  12. The role of marinas and recreational boating in the occurrence and distribution of exotic caprellids (Crustacea: Amphipoda) in the Western Mediterranean: Mallorca Island as a case study

    NASA Astrophysics Data System (ADS)

    Ros, Macarena; Vázquez-Luis, Maite; Guerra-García, José M.

    2013-10-01

    In the Mediterranean Sea, the number of alien marine crustacean species has increased over the past two decades. However, knowledge about small alien marine crustaceans, like caprellid amphipods, is still very scarce. To understand the role of marinas and recreational boating in the early step of the invasion process by non-indigenous caprellids, we studied the recreational boating pressure and the spatial distribution of caprellid species in Mallorca Island. We collected caprellids from 14 marinas and 9 exposed intertidal rocky shores between November 2011 and April 2012 and we analyzed the differences in habitat use of native and exotic caprellids. Eight caprellid species, six native and two exotic, were found. Alien caprellids were only present in marinas, reaching high densities of population. The analysis of recreational boating pressure reveals that Palma-Migjorn is the area that is subject to the highest potential risk of introduction of exotic species via ship fouling. In the secondary dispersal of alien caprellids, the study reflects that recreational boating seems effective as a secondary vector in the transport of exotic species from marinas to marinas but not from marinas to natural and exposed areas. An illustrated key of caprellids from Balearic Island is provided to differentiate native and non-indigenous species.

  13. A reassessment of the phylogenetic utility of genus-level morphological characters in the family Bogidiellidae (Crustacea, Amphipoda), with description of a new species of Eobogidiella Karaman, 1981.

    PubMed

    Sidorov, Dmitry A; Katz, Aron D; Taylor, Steven J; Chertoprud, Mikhail V

    2016-01-01

    Bogidiellidae is the most diverse and cosmopolitan family of stygobiotic amphipods, and inhabits a variety of subterranean biotopes, especially interstitial habitats. While the family is characterized by considerable sexual dimorphism, this dimorphism has adversely affected our understanding of the systematics of the group. Most species have restricted geographic ranges and occur in difficult to sample habitats, so it is common for individual species descriptions to be based on a single sex. In this work we revisit an analysis of morphological characters in an attempt to clarify their phylogenetic utility in resolving taxonomic relationships among genera by introducing a new species, two additional characters, and phylogenetic statistical support values. Eobogidiella venkataramani sp. n., from a spring fed brook in the Shirawati River basin along the escarpment of the Western Ghats (Karnataka, India) differs from the only known congener, Eobogidiella purmamarcensis, from Argentina, in the structure of mouthparts, the shape and ornamentation on gnathopods and characters of the telson. Our phylogenetic analyses indicate that the available morphological characters are not sufficient to resolve phylogenetic relationships within Bogidiellidae, thus these characters alone cannot be used to determine the phylogenetic placement of Eobogidiella venkataramani sp. n. within the family. Nevertheless, Eobogidiella venkataramani sp. n. shares diagnostic characters with Eobogidiella, supporting placement of the new species in this genus. Our findings point towards a critical need to resolve relationships within the family using molecular approaches, along with the development of a suite of additional morphological characters for Bogidiellidae. This is the third species of Bogidiellidae from southern India. PMID:27587976

  14. Re-description of Orchestia stephenseni Cecchini, 1928: designation of neotype and senior synonym to Orchestia constricta A. Costa, 1853 (Crustacea: Amphipoda: Talitridae) by Reversal of Precedence.

    PubMed

    Iaciofano, Davide; Brutto, Sabrina Lo

    2016-01-01

    The beach flea Orchestia stephenseni was originally described by Cecchini (1928), and successively by Karaman (1973). The description of this species will be herein revised by focusing on the variation of the gnathopod 2 in males, as detected during its growth period. An analysis of DNA Barcoding was performed to support the assignment of the taxonomic species to five morphotypes. As the type specimen has not yet been designated, a neotype is assigned. The name of the species is here presented as a valid name as it satisfies the requirements of a Reversal of the Principle of Priority: Orchestia stephenseni takes precedence over the objective synonym Orchestia constricta A. Costa, 1853, in accordance with Article 23.9.2. of the International Code of Zoological Nomenclature. Orchestia stephenseni Cecchini, 1928 becomes nomen protectum, and Orchestia constricta nomen oblitum. The results presented in this paper also support the status of Orchestia stephenseni as a Mediterranean endemic species, thereby rejecting previous Atlantic records. The synonymies for O. stephenseni are revised accordingly. PMID:27515644

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  16. Caribboecetes progreso, a new species of sand-dwelling amphipod (Amphipoda: Corophiidea: Ischyroceridae) from the Gulf of Mexico, with a key for the genus.

    PubMed

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

    2013-01-01

    A new species of the genus Caribboecetes Just, 1983 is described and illustrated from specimens collected on sandy bottoms of the northern Yucatan Peninsula, southeastern Gulf of Mexico. Caribboecetes progreso sp. nov. differs from the closely related species Caribboecetes barbadensis Just, 1983 and Caribboecetes jenikarpae Just, 1984 by the inflated triangular anterolateral flange on basis of gnathopod 2, and from Caribboecetes justi Ortiz & Lemaitre, 1997 by the setose anterolateral surface of coxal plate 7 and basis of pereopod 7. Ecological notes for the new species, a morphological comparison, map of distribution and key for all members in the genus are also provided. PMID:26269839

  17. Making future taxonomy of Niphargus (Crustacea: Amphipoda: Niphargidae) in the Middle East easier: DELTA database of Middle East species with description of four new species from Iran.

    PubMed

    Esmaeili-Rineh, Somayeh; Sari, Alireza; Fišer, Cene

    2015-01-01

    Four new species from the amphipod genus Niphargus are described, namely N. borisi sp. nov., N. bisitunicus sp. nov., N. darvishi sp. nov. and N. sharifi sp. nov. All four species of this predominantly subterranean genus were collected from springs in the Western region of Iran (Zagros region), which is the eastern borderline of the genus range. The species are morphologically diagnosed, described and illustrated. With these newly described species, the total number of Niphargus species in the Middle East reaches twenty-three. In order to facilitate the identification of Niphargus species in the region and to make future taxonomy of the genus easier, we have compiled a database in DEscription Language for TAxonomy (DELTA) using 23 diagnostic traits for these 23 species and subspecies identified in the Middle East. The database is available on the web as supplementary material whereas the dichotomous identification key automatically generated from the database for routine use is provided as a part of the paper. PMID:26624108

  18. Review of amphipods of the Melita group (Amphipoda: Melitidae) from the coastal waters of Sakhalin Island (Far East of Russia). III. Genera Abludomelita Karaman, 1981 and Melita Leach, 1814.

    PubMed

    Labay, Vjacheslav S

    2016-01-01

    The taxonomic analysis of Melita group is performed. The revision of the genus Melita Leach, 1814 was held on the basis of analysis of morphological characters. Cladistic analysis of morphological relationships within genera Abludomelita and Melita is performed. Status of the genus Paraniphargus Tattersall, 1925 restored. New genera Barnardomelita gen. nov. and Ledoyeromelita gen. nov. are described and removed from the composition of the genus Melita. A review of Melita group (fam. Melitidae) from the shelf of Sakhalin Island based on all literature and own data is provided. Based on new material, two new species of the genus Abludomelita Karaman, 1981 are described: A. klitinii sp. nov. and A. okhotensis sp. nov. from the shelf of Sakhalin Island. Megamoera aequidentatum Labay, 2013 is transferred to the genus Abludomelita as A. rotundactyla (Ren, 2012) on the basis of additional morphological description of male. The new subspecies Melita shimizui sakhalinensis ssp. nov. is described from estuaries of Sakhalin Island. The keys to the world species of genera Abludomelita and Melita are provided. PMID:27615866

  19. On the Austral-Antarctic stenothoids Proboloides, Metopoides, Torometopa and Scaphodactylus (Crustacea Amphipoda) Part 2: the genus Proboloides, with description of two new genera and the transfer of two nominal species to Metopoides

    PubMed Central

    Krapp-Schickel, Traudl

    2011-01-01

    Abstract This is the second part of a revision of the most plesiomorphic genera in the amphipod family Stenothoidae sensu lato (see Krapp-Schickel and Koenemann 2006 for an overview and Krapp-Schickel 2008 for the first part). 41 species not belonging to Metopoides were plotted in a matrix using the same 61 characters as in the first part. The resulting group of Proboloides species (most probably not existing in the Austral-Antarctic region) is discussed, a key for the members given and two new genera erected. Some species described as Proboloides are redescribed and 2 species transferred to Metopoides. A key for all actual members of. The remaining species, i.e. those actually being in the genera Torometopa and Scaphodactylus, will be dealt with in the final part of this series, together with a key to all of them. PMID:21594091

  20. A review of the hyperiidean amphipod genus Hyperoche Bovallius, 1887 (Crustacea: Amphipoda: Hyperiidea: Hyperiidae), with the description of a new genus to accommodate H. shihi Gasca, 2005.

    PubMed

    Zeidler, Wolfgang

    2015-01-01

    This is the first comprehensive review of the genus Hyperoche since that of Bovallius (1889). This study is based primarily on the extensive collections of the ZMUC but also on more recent collections in other institutions. Seven valid species are recognised in this review, including one described as new to science. Two new characters were discovered; the first two pereonites are partially or wholly fused dorsally and the coxa of pereopod 7 is fused with the pereonite. These two new characters, combined with the knife-shaped carpus of the gnathopoda and the laminate mandibular molar, help to further distinguish this genus amongst the Hyperiidea. Partly as a result of establishing these distinctive characters, a new genus, Prohyperia gen. nov. is proposed for H. shihi Gasca, 2005 because it has characters not consistent with Hyperoche or the closely related genus Hyperia, to which it also bears some resemblance. Hyperoche medusarum and H. luetkenides, although morphologically similar, are considered separate species, with H. medusarum restricted to the colder waters of the northern Hemisphere and H. luetkenides to the Southern Ocean and Antarctic waters. Hyperoche cryptodactylus, still only known from the unique type, is considered a synonym of H. luetkenides because the character distinguishing it, the retractile dactyl of gnathopod 2, also occurs in some specimens of H. luetkenides and has also been found in other species of Hyperoche. Some specimens also have some pereopoda with partly or wholly retracted dactyls, although there is no pattern to the occurrence. In addition to the above the following species are also considered valid, H. martinezii, H. mediterranea and H. picta, found mainly in the tropical and temperate regions of the Atlantic and Pacific Oceans, and H. capucinus, restricted to the region between the Antarctic Polar Front and the Antarctic Continent. One new species, H. macrocephalus sp. nov., is described from the tropical eastern Indian Ocean and the Mediterranean Sea. All species are described and illustrated and a key is provided to facilitate their identification.  PMID:25661204

  1. Ultrastructure of the embryonic dorsal organ of Orchestia cavimana (crustacea, amphipoda); with a note on localization of chloride and on the change in calcium-deposition before the embryonic moult.

    PubMed

    Meschenmoser, M

    1989-01-01

    The transitory dorsal organ of Orchestia cavimana appears simultaneously with the development of the germ layer and is gradually reduced during the last 2-3 days of embryonic development. It represents the only direct connection of the embryo with the chorion or-after the embryonic moult-with the embryonic envelope. The shape is hemispherical and it consists of about 50 bottle-shaped cells, arranged radially around a centre. This centre is filled with different kinds of extracellular material which forms a central plug apically and a central cone below it. The bottle-shaped cells taper apically. The neck region of these cells is characterized by numerous microvilli which project into the intercellular space. This space is filled with an electron dense substance and is in contact with the central cone. In the basal neck region numerous mitochondria are associated with the microvilli. The high density of mitochondria is characteristic for the nuclear region. The cytoplasm of the basal region below the nucleus contains numerous calcium granules. Evidence for the concentration of chloride in the apical dorsal organ is shown. Before the embryonic moult and during the duplication of the egg-volume the number of calcium granules in the dorsal organ and the integument is reduced. Simultaneously calcium granules appear in the now visible periembryonic space. This suggests that part of the calcium is shifted into this space. The function of the dorsal organ is discussed. Besides the probable main function-transport activity of ions-its role before and during embryonic moult and its part in the utilisation of yolk are discussed. PMID:18620268

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

    PubMed

    Holsinger, John R; Ansell, Lynnette

    2014-01-01

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

  3. ACUTE TOXICITY OF METHYL-PARATHION IN WETLAND MESOCOSMS: INFLUENCE OF AQUATIC PLANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The acute toxicity of methyl-parathion (MeP) introduced into constructed wetlands for the purpose of assessing the importance of emergent vegetation was tested using Hyalella azecta (Crustacea: Amphipoda). A vegetated (90% cover, mainly Juncus effuses) and a non-vegetated wetland (each with a water...

  4. Comparison of food compositon of clupeid fishes in the Bohai Sea

    NASA Astrophysics Data System (ADS)

    Li, Jun; Wang, Hong

    1992-12-01

    Analysis of stomach contents of samples of clupeid fishes (Japanese anchovy, half-fin anchovy, zunas' scaled sardine, rednosed glassnose and tapertail anchovy) collected from the catches of a 1982 1984 fishery resource survey showed they are zooplanktonivorous. Similar food groups, such as copepoda. Chaetognatha, Amphipoda and Mysidacea were found in the stomach. Dietary similarity coefficients were studied to evaluate the degree of similarity in the dietary species-pairs. Seasonal variation is discussed.

  5. Contemporary distribution of macrozoobenthic communities of the Yeisk estuary (Taganrog Bay of the Sea of Azov)

    NASA Astrophysics Data System (ADS)

    Nabozhenko, M. V.; Kovalenko, E. P.

    2011-08-01

    The contemporary distribution of macrozoobenthic communities of the Yeisk estuary is considered. Four basic types of communities are classified. Communities with domination of Tubificidae (Oligochaeta) occupy the greatest part of the estuary. Communities with domination of Amphipoda (Corophiidae) remained only in the northeast part of the reservoir. The unstable hydrological conditions and the absence of clearly expressed horohalinicum lead to mixing of Ponto-Caspian and Azov-Black Sea faunas in the Yeisk estuary.

  6. Diet shifts of lesser scaup are consistent with the spring condition hypothesis

    USGS Publications Warehouse

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

    2006-01-01

    We compared diets of lesser scaup (Aythya affinis (Eyton, 1838)) in the springs of 2000 and 2001 to those reported in the 1970s and the 1980s to determine whether forage quality has declined as predicted by the spring condition hypothesis. In Minnesota, we found that the current aggregate percentage of Amphipoda (an important food item) in lesser scaup diets was 94% lower than that reported from the same locations in the 1980s. Current mean individual prey mass of Amphipoda and Bivalvia in Minnesota were 86.6% and 85.1% lower than historical levels, respectively. In Manitoba, current aggregate percentages of Trichoptera and Chaoboridae in lesser scaup diets (1% and 0%, respectively) were lower than those reported from the same location in the 1970s (14% and 2%, respectively), whereas the percentage of Chironomidae (40%) was higher than that of historical levels (19%). Current mean individual prey mass of all insects, seeds, Chironomidae, and Zygoptera in Manitoba were 63.5%, 65.4%, 44.1%, and 44.9% lower than those of historical levels, respectively. The observed dietary shift from Amphipoda to less nutritious prey in Minnesota, coupled with lower mean individual prey mass in both locations, likely constitutes lower forage quality in lesser scaup diets, which is consistent with the spring condition hypothesis. ?? 2006 NRC.

  7. Comparing Effects of Lake- and Watershed-Scale Influences on Communities of Aquatic Invertebrates in Shallow Lakes

    PubMed Central

    Hanson, Mark A.; Herwig, Brian R.; Zimmer, Kyle D.; Fieberg, John; Vaughn, Sean R.; Wright, Robert G.; Younk, Jerry A.

    2012-01-01

    Constraints on lake communities are complex and are usually studied by using limited combinations of variables derived from measurements within or adjacent to study waters. While informative, results often provide limited insight about magnitude of simultaneous influences operating at multiple scales, such as lake- vs. watershed-scale. To formulate comparisons of such contrasting influences, we explored factors controlling the abundance of predominant aquatic invertebrates in 75 shallow lakes in western Minnesota, USA. Using robust regression techniques, we modeled relative abundance of Amphipoda, small and large cladocera, Corixidae, aquatic Diptera, and an aggregate taxon that combined Ephemeroptera-Trichoptera-Odonata (ETO) in response to lake- and watershed-scale characteristics. Predictor variables included fish and submerged plant abundance, linear distance to the nearest wetland or lake, watershed size, and proportion of the watershed in agricultural production. Among-lake variability in invertebrate abundance was more often explained by lake-scale predictors than by variables based on watershed characteristics. For example, we identified significant associations between fish presence and community type and abundance of small and large cladocera, Amphipoda, Diptera, and ETO. Abundance of Amphipoda, Diptera, and Corixidae were also positively correlated with submerged plant abundance. We observed no associations between lake-watershed variables and abundance of our invertebrate taxa. Broadly, our results seem to indicate preeminence of lake-level influences on aquatic invertebrates in shallow lakes, but historical land-use legacies may mask important relationships. PMID:22970275

  8. Tide-associated biological rhythms of some white sea littoral invertebrates.

    NASA Astrophysics Data System (ADS)

    Gusev, O. A.; Golubev, A. I.

    2001-01-01

    We report the results from two years of laboratory observations of the tide-associated rhythms of activity of White Sea intertidal invertebrates, Mya arenaria (Bivalvia) and Gammarus finmarchicus (Amphipoda). The tidal associated activity of these invertebrates could not be estimate as a clear circatidal clock. Gammarus activity could be phase shifted by a 0.5 h exposure to turbulent water twice a day for 2-3 days. Mya's rhythm could be changed by a single drainage of aquariums lasting about 15 min. This kind of timing system may be a relatively primitive evolution feature.

  9. [Dietary composition and food competition of six main fish species in rocky reef habitat off Gouqi Island].

    PubMed

    Wang, Kai; Zhang, Shou-Yu; Wang, Zhen-Hua; Zhao, Jing; Xu, Min; Lin, Jun

    2012-02-01

    Based on the monthly investigation data of fish resources in the rocky reef habitat off Gouqi Island from March 2009 to February 2010, this paper studied the dietary composition of three native fish species (Sebasticus marmoratus, Hexagrammos otakii and Hexagrammos agrammus) and three non-native fish species (Lateolabrax japonica, Nibea albiflora and Larimichthys polyactis). The analysis of gut content indicated that the main prey items of these six dominant fish species were Caprellidae, Gammaridea, juvenile S. marmoratus, Engraulis japonicas and Acetes chinensis and the dietary composition of each of the 6 fish species had obvious seasonal variation. There was an intense food competition between native species H. otakii and H. agrammus in autumn, between non-native species N. albiflora and L. polyactis in summer, between non-native species N. albiflora and native species S. marmoratus in autumn, and between non-native species N. albiflora and native species H. otakii in winter. It was suggested the non-native species N. albiflora was the key species in the food competition among the six dominant fish species in this rocky reef habitat, and thus the feeding behaviors of these six fish species could have definite effects on the resource capacity of juvenile S. marmoratus. PMID:22586984

  10. Kuril-Kamchatka deep sea revisited - insights into the amphipod abyssal fauna

    NASA Astrophysics Data System (ADS)

    Jażdżewska, Anna

    2015-01-01

    During the KuramBIO expedition to the Kuril-Kamchatka Trench and abyssal plain, benthic samples from the depths from 4987 to 5422 m were collected using a camera-epibenthic sledge. In this collection more than 1200 individuals of Amphipoda were found. They were assigned to 60 taxa (including 47 morphospecies) and 21 families. Until now 28 species being new to science have been found: six in the superfamily Eusiroidea and in the Oedicerotidae and Synopiidae families, four in the Phoxocephalidae, three in the Pardaliscidae, two in the Stenothoidae and one in the Pachynidae. The Synopiidae, Stenothoidae and Pachynidae were recorded for the first time in North-West Pacific area. The dominant and most speciose families were Oedicerotidae, Phoxocephalidae, Synopiidae, Eusiridae s.l. and Lysianassidae. The cluster analysis clearly separated the shallowest sample from the others, which were divided further into two groups. The shallowest sample was characterized by the highest number of species and number of individuals.

  11. The macrofauna and macroflora associated with Laminaria digitata and L. hyperborea at the island of Helgoland (German Bight, North Sea)

    NASA Astrophysics Data System (ADS)

    Schultze, Kirstin; Janke, Klaus; Krüß, Andreas; Weidemann, Wolfgang

    1990-03-01

    This paper describes the macroflora and macrofauna associated with two bull kelp species, Laminaria hyperborea and L. digitata, at the island of Helgoland, North Sea. During a study period of seven months (March September 1987), 29 macroflora species and 125 macrofauna species were found. The dominant taxonomic groups were Polychaeta (25 species), Bryozoa (17), Amphipoda (14), Hydrozoa (10) and Ascidiae (8). The species maximum was in July. In general, L. hyperborea was preferred as a substrate for settlement to L. digitata. Composition of the communities associated with kelp changed during the season according to exposure to wave action, and according to location on the kelp thallus. The rhizoid community of both kelps bore more species at exposed locations. Wave-exposed L. digitata lacked obvious faunal settlement on both phylloid and cauloid. Phylloid and cauloid of L. hyperborea were chosen as an attractive substrate at both sheltered and wave-exposed locations, showing an association of encrusting bryozoan and hydrozoan colonies.

  12. Diet of Lipophrys pholis (L.) (Teleostei, Blenniidae) in Cantabrian coastal waters (Spain)

    NASA Astrophysics Data System (ADS)

    Mazé, Raquel A.; Domínguez, Josefa; Pérez-Cardenal, David

    1999-07-01

    Between February and December 1988, a total of 261 specimens of Lipophrys pholis were caught in eleven intertidal pools on the western coast of Asturias. This blenniid species mainly feeds on different groups of invertebrates, although algal remains also appear. Mollusca is the most highly represented taxon with the largest number of prey being Gastropoda, followed by Bivalvia and, to a lesser degree, Polyplacophora. Crustacea is well represented by Cirripedia. Isopoda also stands out and Amphipoda, Tanaidacea and Decapoda appear sporadically. Temporal diet analysis throughout the year shows no great differences. Likewise, a great similarity was observed among the feeding of L. pholis specimens collected in pools at a different tidal level, of variable size and with different algal cover. Changes in diet are appreciable as size increases, especially from a length of 6 cm on.

  13. Land Use and Hydrogeological Characteristics Influence Groundwater Invertebrate Communities.

    PubMed

    Tione, María Laura; Bedano, José Camilo; Blarasin, Mónica

    2016-08-01

    We examine the influence of land use and hydrogeological characteristics on the abundance, composition and structure of groundwater invertebrate communities in a loessic aquifer from Argentina. Seven wells, selected according to surrounding land use and hydrogeological characteristics, were sampled twice. Groundwater was characterized as sodium bicarbonate, bicarbonate sulfate or sulfate type. NO3(-) was detected in all samples. Land use in the area surrounding the well, unsaturated zone thickness and geochemical characteristics of groundwater influenced the abundance, composition and community structure of groundwater invertebrates. Copepoda, Oligochaeta, Cladocera, Ostracoda and Amphipoda were highly influenced by land use, particularly by point pollution sources that produced higher abundance and changes in taxonomic composition. The lowest invertebrate abundance was observed at the wells situated in areas with the thickest unsaturated zone. Groundwater salinity and geochemical type influenced the presence of certain species, particularly Stygonitocrella sp. PMID:27456146

  14. Epifauna of the Sea of Japan collected via a new epibenthic sledge equipped with camera and environmental sensor systems

    NASA Astrophysics Data System (ADS)

    Brandt, A.; Elsner, N.; Brenke, N.; Golovan, O.; Malyutina, M. V.; Riehl, T.; Schwabe, E.; Würzberg, L.

    2013-02-01

    Faunistic data from a newly designed camera-epibenthic sledge (C-EBS) are presented. These were collected during the joint Russian-German expedition SoJaBio (Sea of Japan Biodiversity Studies) on board the R.V. Akademik Lavrentyev from four transects (A-D) between 460 and 3660 m depth. In total, 244,531 macro- and megafaunal individuals were sampled with the classes Malacostraca (80,851 individuals), Polychaeta (36,253 ind.) and Ophiuroidea (34,004 ind.) being most abundant. Within the Malacostraca, Peracarida (75,716 ind.) were most abundant and within these, the Isopoda were the dominant taxon (27,931 ind.), followed by Amphipoda (21,403 ind.), Cumacea (13,971 ind.) and Tanaidacea (10,830 ind.). Mysidacea (1581 ind.) were least frequent. Bivalvia, Amphipoda, Cumacea and Mysidacea as well as inbenthic meiofaunal Nematoda occurred in higher numbers at the shallower stations and their numbers decreased with increasing depth. Polychaeta, Isopoda, and Tanaidacea, on the contrary, increased in abundance with increasing depth. Only one isopod species was sampled at abyssal depths in the Sea of Japan but at very high abundance: Eurycope spinifrons Gurjanova, 1933 (Asellota: Munnopsidae). Echinoderms occurred frequently at the shallower slope stations. Ophiuroids were dominating, followed by holothurians, and echinoids and asteroids which occurred in lower numbers and primarily at the shallower stations of transects A and B. Only 2163 individual anthozoans were recorded and these were mostly confined to the lower slope. The technical design of a new C-EBS is described. Next to temperature-insulated epi- and suprabenthic samplers, it is equipped with still and video cameras, which deliver information on seabed topography and megafaunal occurrence. Furthermore, Aanderaa CTD and SEAGUARD RCM allow for collection of physical parameters, such as near bottom oxygen composition, temperature and conductivity.

  15. Movement, habitat use, and diet of adult humpback chub

    NASA Astrophysics Data System (ADS)

    Valdez, Richard A.; Hoffnagle, Timothy L.

    The humpback chub (Gila cypha) is a big-river cyprinid fish endemic to the Colorado River, where river regulation has contributed to its endangerment. Flooding is essential to reshaping its habitat, redistributing nutrients, flushing terrestrial insects for food, and, in the post-dam river, controlling non-native competitors and predators. Effects of the 1996 controlled flood on movement and habitat use of adults were monitored with radiotelemetry, and diet was evaluated with a non-lethal stomach pump. Movement of 9 radio-tagged adults during the flood (mean, 0.40 km; range, 0-1.24 km) was not significantly different (P≤0.05) from movement in the month preceding the flood (mean, 1.26 km; range, 0.1-2.95 km), indicating no unusual movement or displacement of fish by the flood. Habitat used during the flood, as a percentage of radio-contacts (i.e., 73% eddies, 19% runs, 8% tributary inflows), was similar to that used under normal operations by 69 fish tracked during 1990-1992 (i.e., 74% eddies, 12% runs, 7% backwaters, 6% tributary inflows, 1% pools, <1% riffles). Diet of 43 adults showed dramatic shifts to items scoured by the flood. Simuliidae (68% ash-free dry weight) and Chironomidae (15%) dominated pre-flood diets; Amphipoda (31%), Simuliidae (25%), and terrestrial insects (i.e., beetles, ants, grasshoppers, 20%) were ingested during the flood; and Simuliidae (62%) and Amphipoda (18%) were eaten post-flood. While composition of the diet changed, biomass consumed was not significantly affected by the flood (P = 0.9157). The controlled flood had no detrimental effects on movement, habitat use, or diet of adult humpback chub. Effects of habitat reshaping and nutrient redistribution can only be evaluated through long-term monitoring. Floods of higher magnitude or at a different time of year may have different effects on this endangered species and should be investigated before implementing controlled floods as an element of dam operations.

  16. Fatty acid patterns of Southern Ocean shelf and deep sea peracarid crustaceans and a possible food source, foraminiferans

    NASA Astrophysics Data System (ADS)

    Würzberg, Laura; Peters, Janna; Brandt, Angelika

    2011-10-01

    In order to investigate the diversity of diet composition in macrobenthic peracarid crustaceans from the Antarctic shelf and deep sea, the fatty acid (FA) composition of different species belonging to the orders Isopoda, Amphipoda, Cumacea and Tanaidacea was analysed. Multivariate analyses of the FA composition confirmed general differences between the orders, but also distinct differences within these orders. To gain information on the origin of the FAs found, the potential food sources sediment, POM and foraminiferans were included in the study. Most of the analysed amphipod species displayed high 18:1( n-9)-18:1( n-7) ratios, widely used as an indicator for a carnivorous component in the diet. Cumaceans were characterised by increased phytoplankton FA markers such as 20:5( n-3) (up to 29% of total FAs), suggesting a diet based on phytodetritus. High values of the FA 20:4( n-6) were found in some munnopsid isopods (up to 21% of total FAs) and some tanaidacean species (up to 19% of total FAs). 20:4( n-6) also occurred in high proportions in some foraminiferan samples (up to 21% of total fatty acids), but not in sediment and POM, possibly indicating the ingestion of foraminiferans by some peracarid crustaceans.

  17. Is the freshwater gammarid, Dikerogammarus villosus, a suitable sentinel species for the implementation of histochemical biomarkers?

    PubMed

    Guerlet, Edwige; Ledy, Karine; Giambérini, Laure

    2008-06-01

    In order to enlarge the range of potential sentinel species for the implementation of a multiple biomarker approach, spatial and monthly morphological variations of four cellular compartments and contents were assessed during two years in the hepatopancreatic caeca of the freshwater gammarid, Dikerogammarus villosus (Crustacea, Amphipoda), using histochemistry coupled to image analysis. Among the three study sites, the second one, located in a reservoir receiving the overheated and copper-contaminated waters of a nuclear power plant, was the most anthropised. During this passive biomonitoring survey, unsaturated neutral lipids were more abundant, the surface densities of the lysosomal and peroxisomal systems were, respectively less and more important, and lipofuscin granules tended to accumulate in the amphipods from the second site compared to both others. Nonetheless, in this context, the present cellular biomarker suite, analysed through an integrative approach, was not powerful enough to highlight spatial heterogeneity significantly. This may partly result from particularities in the patterns of metal accumulation and copper physiological requirements of amphipods (haemocyanin synthesis). Nevertheless, we think that the use of this Ponto-Caspian non-indigenous species in biomonitoring surveys deserves further investigation, owing to its current position in freshwater and brackish European ecosystems, considering both biomass and functioning. Cellular responses could be studied in parallel with endpoints at other levels of the biological organization to compose a more powerful biomarker suite. Furthermore, comparing biological responses to environmental stress in this invasive species and less competitive autochthonous gammarids could be of great interest. PMID:18499217

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

    PubMed

    Médoc, Vincent; Beisel, Jean-Nicolas

    2009-04-01

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

  19. Diversity of Tanaidacea (Crustacea: Peracarida) in the World's Oceans – How Far Have We Come?

    PubMed Central

    Blazewicz-Paszkowycz, Magdalena; Bamber, Roger; Anderson, Gary

    2012-01-01

    Tanaidaceans are small peracarid crustaceans which occur in all marine habitats, over the full range of depths, and rarely into fresh waters. Yet they have no obligate dispersive phase in their life-cycle. Populations are thus inevitably isolated, and allopatric speciation and high regional diversity are inevitable; cosmopolitan distributions are considered to be unlikely or non-existent. Options for passive dispersion are discussed. Tanaidaceans appear to have first evolved in shallow waters, the region of greatest diversification of the Apseudomorpha and some tanaidomorph families, while in deeper waters the apseudomorphs have subsequently evolved two or three distinct phyletic lines. The Neotanaidomorpha has evolved separately and diversified globally in deep waters, and the Tanaidomorpha has undergone the greatest evolution, diversification and adaptation, to the point where some of the deep-water taxa are recolonizing shallow waters. Analysis of their geographic distribution shows some level of regional isolation, but suffers from inclusion of polyphyletic taxa and a general lack of data, particularly for deep waters. It is concluded that the diversity of the tanaidomorphs in deeper waters and in certain ocean regions remains to be discovered; that the smaller taxa are largely understudied; and that numerous cryptic species remain to be distinguished. Thus the number of species currently recognized is likely to be an order of magnitude too low, and globally the Tanaidacea potentially rival the Amphipoda and Isopoda in diversity. PMID:22496741

  20. Density-Dependent Effects of an Invasive Ant on a Ground-Dwelling Arthropod Community.

    PubMed

    Cooling, M; Sim, D A; Lester, P J

    2015-02-01

    It is frequently assumed that an invasive species that is ecologically or economically damaging in one region, will typically be so in other environments. The Argentine ant Linepithema humile (Mayr) is listed among the world's worst invaders. It commonly displaces resident ant species where it occurs at high population densities, and may also reduce densities of other ground-dwelling arthropods. We investigated the effect of varying Argentine ant abundance on resident ant and nonant arthropod species richness and abundance in seven cities across its range in New Zealand. Pitfall traps were used to compare an invaded and uninvaded site in each city. Invaded sites were selected based on natural varying abundance of Argentine ant populations. Argentine ant density had a significant negative effect on epigaeic ant abundance and species richness, but hypogaeic ant abundance and species richness was unaffected. We observed a significant decrease in Diplopoda abundance with increasing Argentine ant abundance, while Coleoptera abundance increased. The effect on Amphipoda and Isopoda depended strongly on climate. The severity of the impact on negatively affected taxa was reduced in areas where Argentine ant densities were low. Surprisingly, Argentine ants had no effect on the abundance of the other arthropod taxa examined. Morphospecies richness for all nonant arthropod taxa was unaffected by Argentine ant abundance. Species that are established as invasive in one location therefore cannot be assumed to be invasive in other locations based on presence alone. Appropriate management decisions should reflect this knowledge. PMID:26308805

  1. Gene Genealogies Strongly Distorted by Weakly Interfering Mutations in Constant Environments

    PubMed Central

    Seger, Jon; Smith, Wendy A.; Perry, Jarom J.; Hunn, Jessalynn; Kaliszewska, Zofia A.; Sala, Luciano La; Pozzi, Luciana; Rowntree, Victoria J.; Adler, Frederick R.

    2010-01-01

    Neutral nucleotide diversity does not scale with population size as expected, and this “paradox of variation” is especially severe for animal mitochondria. Adaptive selective sweeps are often proposed as a major cause, but a plausible alternative is selection against large numbers of weakly deleterious mutations subject to Hill–Robertson interference. The mitochondrial genealogies of several species of whale lice (Amphipoda: Cyamus) are consistently too short relative to neutral-theory expectations, and they are also distorted in shape (branch-length proportions) and topology (relative sister-clade sizes). This pattern is not easily explained by adaptive sweeps or demographic history, but it can be reproduced in models of interference among forward and back mutations at large numbers of sites on a nonrecombining chromosome. A coalescent simulation algorithm was used to study this model over a wide range of parameter values. The genealogical distortions are all maximized when the selection coefficients are of critical intermediate sizes, such that Muller's ratchet begins to turn. In this regime, linked neutral nucleotide diversity becomes nearly insensitive to N. Mutations of this size dominate the dynamics even if there are also large numbers of more strongly and more weakly selected sites in the genome. A genealogical perspective on Hill–Robertson interference leads directly to a generalized background-selection model in which the effective population size is progressively reduced going back in time from the present. PMID:19966069

  2. The natural history of Echinorhynchus bothniensis Zdzitowiecki and Valtonen, 1987 (Acanthocephala) in a high Arctic lake.

    PubMed

    Aura, Raija-Liisa; Benesh, Daniel P; Palomaki, Risto; Tellervo Valtonen, E

    2015-01-01

    The acanthocephalan Echinorhynchus bothniensis Zdzitowiecki and Valtonen, 1987 differs from most other species in the genus Echinorhynchus Zoega in Müller, 1776 by infecting mysids (order Mysida) instead of amphipods (order Amphipoda) as intermediate hosts. Here we report on the occurrence of E. bothniensis in mysids (Mysis segerstralei Audzijonytė et Väinölä) and in its fish definitive hosts in a high Arctic lake. Out of 15 907 sampled mysids, 4.8% were infected with a mean intensity of 1.05 worms (range 1-5), although there was notable variation between samples taken in different years and sites. Larger mysids appear more likely to be infected. Of five fish species sampled, charr,Salvelinus alpinus (Linnaeus), and a benthic-feeding whitefish morph, Coregonus lavaretus (Linnaeus), were the most heavily infected (mean abundances of 80 and 15, respectively). The adult parasite population in fish exhibited a female-biased sex ratio (1.78 : 1). Although E. bothniensis is rather unique in infecting mysids, many aspects of its natural history mirror that of other acanthocephalan species. PMID:26373432

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

    NASA Astrophysics Data System (ADS)

    Médoc, Vincent; Beisel, Jean-Nicolas

    2009-04-01

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

  4. Vertical distribution and diel migration of macrozooplankton in the St. Lawrence marine system (Canada) in relation with the cold intermediate layer thermal properties

    NASA Astrophysics Data System (ADS)

    Harvey, Michel; Galbraith, Peter S.; Descroix, Aurélie

    2009-01-01

    Vertical distribution of various species and stages of macrozooplankton (euphausiacea, chaetognatha, cnidaria, mysidacea, amphipoda) were determined for different times of the day and related to the physical environment. Stratified sampling with the BIONESS was carried out during seven cruises in spring and fall 1998, 2000, and 2001, and fall 1999, in two different habitats in the St. Lawrence marine system: the lower St. Lawrence Estuary and the NW Gulf of St. Lawrence. Our results indicate that the various macrozooplankton species were distributed throughout the whole water column including the surface layer, the cold intermediate layer (CIL), and the deep layer at different times of day and night in both areas during all periods. Moreover, three types of migrational patterns were observed within this zooplanktonic community: (1) nocturnal ascent by the whole population, (2) segregation into two groups; one which performed nocturnal accent and another which remained in the deep, and (3) no detectable migration. We also observed that the diel vertical migration (DVM) amplitude in most of the macrozooplankton species varied as a function of physical factors, in particular the spatio-temporal variations of the CIL thermal properties, including the upper and the lower limits of the CIL and the depth of the CIL core temperature. Finally, the different DVM patterns coupled with estuarine circulation patterns and bottom topography could place animals in different flow regimes by night and by day and contribute to their retention (aggregation) and/or dispersion in different areas, time of the day, and seasons.

  5. Meiobenthos assemblages in the mekong estuarine system with special focus on free-living marine nematodes

    NASA Astrophysics Data System (ADS)

    Quang, Ngo Xuan; Vanreusel, Ann; Smol, Nic; Chau, Nguyen Ngoc

    2010-12-01

    Meiobenthos assemblages in eight estuaries of the Mekong river system were investigated in August 2008 (from the Cua Tieu estuary to the Tran De estuary). In each estuary, one sampling station was established for meiobenthos sampling. Twelve major taxa of meiobenthos were recorded in this estuarine system, including Nematoda, Copepoda, Turbellaria, Polychaeta, Oligochaeta, Tardigrada, Bivalvia, Ostracoda, Amphipoda, Cumacea, Gastrotricha, Gastropoda, and Crustacean Nauplii larvae. The densities of the meiobenthos range from 581 to 3168 inds/10 cm2. Nematodes always occupy the highest numbers with a percentage ranging from 64-99%. There are 135 nematode genera recorded in this study with the following as dominant genera Desmodora, Leptolaimus, Halalaimus, Thalassomonhystera, Theristus, Daptonema, Rhynchonema, Parodontophora, and Oncholaimus. Although the biodiversity of the meiobenthos at higher taxa level is not high compared to other marine environments, the estimates of nematode biodiversity at the genus level indicates high values. The increase in number of genera with increasing sampling intensity illustrate that the diversity is underestimated and would have been higher if the authors had considered a larger number of individuals, more replicates per station, and more sampling stations.

  6. Gene genealogies strongly distorted by weakly interfering mutations in constant environments.

    PubMed

    Seger, Jon; Smith, Wendy A; Perry, Jarom J; Hunn, Jessalynn; Kaliszewska, Zofia A; Sala, Luciano La; Pozzi, Luciana; Rowntree, Victoria J; Adler, Frederick R

    2010-02-01

    Neutral nucleotide diversity does not scale with population size as expected, and this "paradox of variation" is especially severe for animal mitochondria. Adaptive selective sweeps are often proposed as a major cause, but a plausible alternative is selection against large numbers of weakly deleterious mutations subject to Hill-Robertson interference. The mitochondrial genealogies of several species of whale lice (Amphipoda: Cyamus) are consistently too short relative to neutral-theory expectations, and they are also distorted in shape (branch-length proportions) and topology (relative sister-clade sizes). This pattern is not easily explained by adaptive sweeps or demographic history, but it can be reproduced in models of interference among forward and back mutations at large numbers of sites on a nonrecombining chromosome. A coalescent simulation algorithm was used to study this model over a wide range of parameter values. The genealogical distortions are all maximized when the selection coefficients are of critical intermediate sizes, such that Muller's ratchet begins to turn. In this regime, linked neutral nucleotide diversity becomes nearly insensitive to N. Mutations of this size dominate the dynamics even if there are also large numbers of more strongly and more weakly selected sites in the genome. A genealogical perspective on Hill-Robertson interference leads directly to a generalized background-selection model in which the effective population size is progressively reduced going back in time from the present. PMID:19966069

  7. Contrasting effects of chloride on growth, reproduction, and toxicant sensitivity in two genetically distinct strains of Hyalella azteca.

    PubMed

    Soucek, David J; Mount, David R; Dickinson, Amy; Hockett, J Russell; McEwen, Abigail R

    2015-10-01

    The strain of Hyalella azteca (Saussure: Amphipoda) commonly used for aquatic toxicity testing in the United States has been shown to perform poorly in some standardized reconstituted waters frequently used for other test species. In 10-d and 42-d experiments, the growth and reproduction of the US laboratory strain of H. azteca was shown to vary strongly with chloride concentration in the test water, with declining performance observed below 15 mg/L to 20 mg/L. In contrast to the chloride-dependent performance of the US laboratory strain of H. azteca, growth of a genetically distinct strain of H. azteca obtained from an Environment Canada laboratory in Burlington, Ontario, Canada, was not influenced by chloride concentration. In acute toxicity tests with the US laboratory strain of H. azteca, the acute toxicity of sodium nitrate increased with decreasing chloride in a pattern similar not only to that observed for control growth, but also to previous acute toxicity testing with sodium sulfate. Subsequent testing with the Burlington strain showed no significant relationship between chloride concentration and the acute toxicity of sodium nitrate or sodium sulfate. These findings suggest that the chloride-dependent toxicity shown for the US laboratory strain may be an unusual feature of that strain and perhaps not broadly representative of aquatic organisms as a whole. PMID:26260521

  8. Use of multiple regression models in the study of sandhopper orientation under natural conditions

    NASA Astrophysics Data System (ADS)

    Marchetti, Giovanni M.; Scapini, Felicita

    2003-10-01

    In sandhoppers (Amphipoda; Talitridae), typical dwellers of the supralittoral zone of sandy beaches, orientation with respect to the sun and landscape vision is adapted to the local direction of the shoreline. Variation of this behavioural adaptation can be related to the characteristics of the beach. Measures of orientation with respect to the shoreline direction can thus be made as a tool to assess beach stability versus changeability, once the sources of variation are correctly interpreted. Orientation of animals can be studied by statistical analysis of directions taken after release in nature. In this paper some new tools for exploring directional data are reviewed, with special emphasis on non-parametric smoothers and regression models. Results from a large study concerning one species of sandhoppers, Talitrus saltator (Montagu), from an exposed sandy beach in northeastern Tunisia are presented. Seasonal differences in orientation behaviour were shown with a higher scatter in autumn with respect to spring. The higher scatter shown in autumn depended both on intrinsic (sex) and external (climatic conditions and landscape visibility) factors and was related to the tendency of this species to migrate towards the dune anticipating winter conditions.

  9. Potential impact of Dare County landfills on Alligator River National Wildlife Refuge

    USGS Publications Warehouse

    Winger, P.V.; Lasier, P.J.; Augspurger, T.

    2005-01-01

    Runoff of leachate from East Lake and Dare County Construction and Demolition Debris landfills has the potential to impact wildlife resources at Alligator River National Wildlife Refuge, Dare and Hyde Counties, North Carolina. Sediment quality of samples collected in August 2000 at 14 locations down-gradient from the landfills was assessed by measuring metal and organic contaminants in the sediments, chronic toxicity of solid-phase sediment (28-d static-renewal exposures; survival and growth as test endpoints) and acute toxicity of sediment porewater (96-h static exposures) to Hyalella azteca (Crustacea: Amphipoda). In addition, contaminant bioaccumulation from 4 sediments was determined using 28-d exposures of Lumbriculus variegatus (freshwater oligochaete). Although survival was not impaired, length of H. azteca was significantly reduced in sediments from 5 locations. Pore water from 4 locations was acutely toxic to H. azteca. Metals and a few polycyclic aromatic hydrocarbons (PAHs) were bioaccumulated by L. variegatus from the sediments. Several metals and PAHs exceeded sediment quality guidelines, and metals in porewater from several sites exceeded water quality criteria for the protection of aquatic wildlife. Runoff of leachate from the landfills has reduced sediment quality and has the potential to adversely affect wildlife resources at Alligator River National Wildlife Refuge.

  10. Macrofaunal involvement in the sublittoral decay of kelp debris: the detritivore community and species interactions

    NASA Astrophysics Data System (ADS)

    Bedford, A. P.; Moore, P. G.

    1984-01-01

    The fauna associated with sea-bed accumulations of decomposing Laminaria saccharina has been studied by year-round SCUBA diving at two sites in the Clyde Sea area. Seasonal changes in density of 64 species are reported. In the autumn, large quantities of kelp are detached by storms. This weed carries with it to the sea bed a large part of its normal fauna. Additional species settle onto the weed from the plankton whilst others migrate onto it from the surrounding sea bed. Peak densities of associated species were recorded in autumn. Litter bag experiments in situ showed that, except during the summer, weed is lost from sea-bed accumulations at a faster rate when macrofaunal animals are excluded. The macrofauna therefore inhibits decomposition. The relative importance of interactive cropping by three macrodetritivores, Psammechinus miliaris (Echinodermata), Platynereis dumerilii (Polychaeta) and Gammarus locusta (Amphipoda) was studied by in situ containment of different species combinations. The presence of Gammarus with Psammechinus resulted in less weed being lost than when Psammechinus was isolated. This is because Gammarus selectively crops rotting weed, retarding frond disintegration by microbes. Platynereis retards microbial colonization of frond tissues ruptured during its feeding by repeated cropping of the same region. Weed would decompose very rapidly were it not for macrofaunal cropping. Macroalgal decay thus differs profoundly from that of vascular plants.

  11. Sediment-quality assessment of the Lower Oconee River

    USGS Publications Warehouse

    Lasier, P.J.; Winger, P.V.; Shelton, J.L., Jr.; Bogenrieder, K.J.

    2004-01-01

    Sediment quality was assessed at multiple sites in the lower Oconee River, GA to identify contaminants potentially affecting the survival of an endemic ?At-Risk? species of fish, the robust redhorse (Moxostoma robustum). Five major tributaries that drain urban and agricultural watersheds enter this stretch of river and several carry permitted municipal and industrial effluents containing Cd, Cu, and Zn. Sediments for chemical analyses and toxicity tests with Hyalella azteca (Amphipoda) were collected at 12 locations that included sites above and below the major tributaries. Compared to national data bases and to the nearby Apalachicola-Chattahoochee-Flint watershed, sediments from the Oconee River had elevated concentrations of Cr, Cu, Hg and Zn. Zinc concentrations showed a marked increase in sediment downstream of the confluence of Buffalo Creek demonstrating contributions from permitted municipal and industrial effluents discharged to that tributary. When exposed to these sediments, growth of H. azteca was significantly reduced. Amphipod growth was also reduced when exposed to sediments collected from another site due to toxicity from Cr. Sediments in the lower Oconee River appear to be impaired due to metal contamination and could pose a threat to organisms, such as the robust redhorse, that are closely associated with this matrix during their life cycle.

  12. A new hedrurid species (Nematoda) from galaxiid fishes in Patagonia (Argentina) and infection of amphipods as intermediate host.

    PubMed

    Brugni, Norma L; Viozzi, Gustavo P

    2010-02-01

    During a parasite survey of galaxiid fishes (Galaxiidae) from Patagonian Andean lakes, a new species of nematode, Hedruris suttonae n. sp. was collected from the stomach of the native Galaxias maculatus (Jenyns) and G. platei (Steindachner). Specimens were examined by light and scanning electron microscopy, especially head morphology, female caudal prehensile structure, and distribution of spines. The new species is distinguished by body and tail size, morphology and size of spicules, the arrangement of caudal papillae in the male, the female caudal hook, and size of eggs. Hyalella patagonica (Ortmann), a Neotropical species of Amphipoda, is reported as its natural intermediate host. Data regarding prevalence and mean intensity in the intermediate and definitive hosts are included. The diet and habitat of the hosts, the percentage of gravid females, the high values of prevalence, and mean intensity in galaxiid fishes, as well as the wide distribution of H. suttonae , collectively indicate that, in these oligotrophic Andean lakes, G. maculatus and G. platei are true definitive hosts of this nematode. PMID:19737026

  13. Food of forage fishes in western Lake Erie, 1975-76

    USGS Publications Warehouse

    Muth, Kenneth M.; Busch, Wolf-Dieter N.

    1989-01-01

    In western Lake Erie in the summer and fall of 1975–1976, food eaten by seven forage fishes—emerald shiner (Notropis atherinoides), spottail shiner (Notropis hudsonius), trout-perch (Percopsis omiscomaycus), andyoung-of-the-year (YOY) of alewife (Alosa pseudoharengus), gizzard shad (Dorosoma cepedianum), white bass (Morone chrysops), and freshwater drum (Aplodi-notus grunniens)—was divided among six major taxa: Cladocera, Copepoda, Diptera, Ostracoda, Amphipoda, and Algae. In addition, fish were eaten by YOY white bass, and Rotifera were consumed by YOY gizzard shad. Interspecies diet overlap indices, calculated to compare the food of the different species and to evaluate diet similarities, were usually highest for YOY white bass and YOY freshwater drum when compared with the other species and usually lowest between emerald shiners and all other forage fishes. Understanding the feeding interactions among fishes that could influence production at the forage-food level of the food web could provide insight into how cascading trophic interactions influence the production of piscivorous predators.

  14. Response of stream invertebrates to a global-warming thermal regime: An ecosystem-level manipulation

    SciTech Connect

    Hogg, I.D.; Williams, D.D.

    1996-03-01

    We manipulated, in accord with global-warming predictions, the thermal regime of a permanent first-order stream near Toronto, Ontario, Canada. We examined the effects of a 2-3.5{degrees}C water-temperature increase on densities, biomass, species composition, and life histories of resident stream invertebrates. The stream was divided longitudinally at the source into two channels, one control and one experimental, and a before and after (BACI) design was employed such that one pre-manipulation year was followed by 2 yr of the temperature manipulation. Changes in the experimental channel following commencement of the manipulation included: (1) decreased total animal densities, particularly Chironomidae (Diptera); (2) earlier onset of adult insect emergence; (3) increased growth rates and precocious breeding in Hyallella azteca (Amphipoda); (4) smaller size at maturity for Nemoura trispinosa (Plecoptera) and H., azteca and (5) altered sex ratios for Lepidostoma vernale (Trichoptera). These results partially corroborate previous laboratory and field studies. However, variation in the responses of individual target species to the manipulation was unexpected and may have been influenced by the genetic structure of local populations. We conclude that levels of gene flow among habitats may be critical to the degree of impact seen as a result of large-scale thermal perturbation (e.g., global warming). 60 refs., 13 figs., 1 tab.

  15. Field and laboratory investigations on the effects of road salt (NaCl) on stream macroinvertebrate communities.

    PubMed

    Blasius, B J; Merritt, R W

    2002-01-01

    Field and laboratory experiments were conducted to examine the effects of road salt (NaCI) on stream macroinvertebrates. Field studies investigated leaf litter processing rates and functional feeding group composition at locations upstream and downstream from point source salt inputs in two Michigan, USA streams. Laboratory studies determined the effects of increasing NaCl concentrations on aquatic invertebrate drift, behavior, and survival. Field studies revealed that leaves were processed faster at upstream reference sites than at locations downstream from road salt point source inputs. However, it was sediment loading that resulted in partial or complete burial of leaf packs, that affected invertebrate activity and confounded normal leaf pack colonization. There were no significant differences that could be attributed to road salt between upstream and downstream locations in the diversity and composition of invertebrate functional feeding groups. Laboratory drift and acute exposure studies demonstrated that drift of Gammarus (Amphipoda) may be affected by NaCl at concentrations greater than 5000 mg/l for a 24-h period. This amphipod and two species of limnephilid caddisflies exhibited a dose response to salt treatments with 96-h LC50 values of 7700 and 3526 mg NaCl/l, respectively. Most other invertebrate species and individuals were unaffected by NaCl concentrations up to 10,000 mg/l for 24 and 96 h, respectively. PMID:12395833

  16. Contrasting effects of hydrological stability and flow extremes on benthic and hyporheic invertebrate communities

    NASA Astrophysics Data System (ADS)

    Stubbington, Rachel; Wood, Paul J.; Reid, Ian

    2010-05-01

    In lotic ecosystems, the most common disturbance events occur at the extremes of the hydrological continuum, i.e. spates and streambed drying. During spates, high flow velocities can mobilise sediments and displace invertebrates, and during streambed drying, loss of free water can cause mass mortality of many aquatic taxa. In both cases, invertebrates inhabiting the surface sediments are subject to a greater frequency and magnitude of disturbance than those in the hyporheic zone, and this habitat may therefore act as a refugium. Between extreme events, stable hydrological conditions allow competitive species to thrive, which can cause biotic interactions to increase. We compared the effects of flow extremes and hydrological stability on benthic and hyporheic invertebrate communities. Hydrological conditions included spates, flow recession, and localised streambed drying. During flow recession, competitive benthic taxa, particularly Gammarus pulex (Amphipoda) increased in abundance in surface sediments, causing community diversity to decline. A concurrent increase in the hyporheic abundance of G. pulex indicated that the hyporheic zone may act as a refugium from increasing biotic pressures in the benthic sediments. In contrast, spate events caused severe reductions in both benthic and hyporheic invertebrate abundance, and declines in G. pulex abundance were particularly pronounced; spate events were therefore important in increasing both benthic and hyporheic community diversity.

  17. Possible effects of global environmental changes on Antarctic benthos: a synthesis across five major taxa.

    PubMed

    Ingels, Jeroen; Vanreusel, Ann; Brandt, Angelika; Catarino, Ana I; David, Bruno; De Ridder, Chantal; Dubois, Philippe; Gooday, Andrew J; Martin, Patrick; Pasotti, Francesca; Robert, Henri

    2012-02-01

    Because of the unique conditions that exist around the Antarctic continent, Southern Ocean (SO) ecosystems are very susceptible to the growing impact of global climate change and other anthropogenic influences. Consequently, there is an urgent need to understand how SO marine life will cope with expected future changes in the environment. Studies of Antarctic organisms have shown that individual species and higher taxa display different degrees of sensitivity to environmental shifts, making it difficult to predict overall community or ecosystem responses. This emphasizes the need for an improved understanding of the Antarctic benthic ecosystem response to global climate change using a multitaxon approach with consideration of different levels of biological organization. Here, we provide a synthesis of the ability of five important Antarctic benthic taxa (Foraminifera, Nematoda, Amphipoda, Isopoda, and Echinoidea) to cope with changes in the environment (temperature, pH, ice cover, ice scouring, food quantity, and quality) that are linked to climatic changes. Responses from individual to the taxon-specific community level to these drivers will vary with taxon but will include local species extinctions, invasions of warmer-water species, shifts in diversity, dominance, and trophic group composition, all with likely consequences for ecosystem functioning. Limitations in our current knowledge and understanding of climate change effects on the different levels are discussed. PMID:22423336

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

    PubMed

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

    2009-01-01

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

  19. The Early Shorebird Will Catch Fewer Invertebrates on Trampled Sandy Beaches

    PubMed Central

    Schlacher, Thomas A.; Carracher, Lucy K.; Porch, Nicholas; Connolly, Rod M.; Olds, Andrew D.; Gilby, Ben L.; Ekanayake, Kasun B.; Maslo, Brooke; Weston, Michael A.

    2016-01-01

    Many species of birds breeding on ocean beaches and in coastal dunes are of global conservation concern. Most of these species rely on invertebrates (e.g. insects, small crustaceans) as an irreplaceable food source, foraging primarily around the strandline on the upper beach near the dunes. Sandy beaches are also prime sites for human recreation, which impacts these food resources via negative trampling effects. We quantified acute trampling impacts on assemblages of upper shore invertebrates in a controlled experiment over a range of foot traffic intensities (up to 56 steps per square metre) on a temperate beach in Victoria, Australia. Trampling significantly altered assemblage structure (species composition and density) and was correlated with significant declines in invertebrate abundance and species richness. Trampling effects were strongest for rare species. In heavily trafficked plots the abundance of sand hoppers (Amphipoda), a principal prey item of threatened Hooded Plovers breeding on this beach, was halved. In contrast to the consistently strong effects of trampling, natural habitat attributes (e.g. sediment grain size, compactness) were much less influential predictors. If acute suppression of invertebrates caused by trampling, as demonstrated here, is more widespread on beaches it may constitute a significant threat to endangered vertebrates reliant on these invertebrates. This calls for a re-thinking of conservation actions by considering active management of food resources, possibly through enhancement of wrack or direct augmentation of prey items to breeding territories. PMID:27564550

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

    PubMed

    Timofeyev, M A; Steinberg, C E W

    2006-10-01

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

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

    PubMed

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

    2016-07-01

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

  2. Mitogenomic phylogenetic analysis supports continental-scale vicariance in subterranean thalassoid crustaceans.

    PubMed

    Bauzà-Ribot, Maria M; Juan, Carlos; Nardi, Francesco; Oromí, Pedro; Pons, Joan; Jaume, Damià

    2012-11-01

    Many continental subterranean water crustaceans ("stygobionts") display extreme disjunct distributions, where different species in the same genus are isolated on continents or islands separated by broad oceanic expanses. Despite their freshwater habitat, most of these taxa appear to be most closely related to typical marine groups ("thalassoid" origin). Among the hadzioids-thalassoid amphipods including the stygobiont families Hadziidae, Pseudoniphargidae, and Metacrangonyctidae-several genera are restricted to inland groundwaters ranging from the Caribbean region to the Mediterranean and Middle East, including interspersed oceanic islands. This distribution might have arisen from Tethyan vicariance triggered by the sequential occlusion of the former Tethys Sea, a vast circumtropical ocean existing from the Middle Jurassic up to 20 million years ago (mya). Previous studies have been based on morphological analyses or limited DNA sequence data, making it difficult to test this hypothesis. We used complete mitochondrial protein-coding gene sequences, mainly obtained by next-generation sequencing methods and a nuclear ribosomal gene to resolve the phylogeny and to establish a time frame for diversification of the family Metacrangonyctidae (Amphipoda). The results were consistent with the plate tectonics vicariance hypothesis, with major diversifications occurring between 96 and 83 mya. PMID:23063439

  3. Composition and abundance of epibenthic-sledge catches in the South Polar Front of the Atlantic

    NASA Astrophysics Data System (ADS)

    Brandt, A.; Havermans, C.; Janussen, D.; Jörger, K. M.; Meyer-Löbbecke, A.; Schnurr, S.; Schüller, M.; Schwabe, E.; Brandão, S. N.; Würzberg, L.

    2014-10-01

    An epibenthic sledge (EBS) was deployed at seven different deep-sea stations along the South Polar Front of the Atlantic in order to explore the composition and abundance of macrofaunal organisms and to identify the most abundant taxa in this transition zone to the Southern Ocean. In total 3,130 specimens were sampled by means of the EBS on board of RV Polarstern during the expedition ANT-XXVIII/3 in the austral summer of 2012. Benthic and suprabenthic Crustacea occurred to be most frequent in the samples. Among those, copepods were by far most numerous, with 1,585 specimens followed by the peracarid taxa Isopoda (236 ind.), Amphipoda (103 ind.), Tanaidacea (78 ind.) and Cumacea (50 ind.). Annelida were represented by a high number of specimens belonging to different polychaete taxa (404 ind.). The molluscan fauna was clearly dominated by Bivalvia (255 ind.), followed in numbers of specimens by Gastropoda (47 ind.). The deep-sea benthos sampled along the Southern Polar Front occurred in surprisingly low abundances, contrasting the largely high surface productivity of the area. Numbers of specimens across different macrofaunal taxa and especially of peracarid crustaceans underscored by far those from South Ocean sites at higher latitudes in the Weddell Sea.

  4. The Early Shorebird Will Catch Fewer Invertebrates on Trampled Sandy Beaches.

    PubMed

    Schlacher, Thomas A; Carracher, Lucy K; Porch, Nicholas; Connolly, Rod M; Olds, Andrew D; Gilby, Ben L; Ekanayake, Kasun B; Maslo, Brooke; Weston, Michael A

    2016-01-01

    Many species of birds breeding on ocean beaches and in coastal dunes are of global conservation concern. Most of these species rely on invertebrates (e.g. insects, small crustaceans) as an irreplaceable food source, foraging primarily around the strandline on the upper beach near the dunes. Sandy beaches are also prime sites for human recreation, which impacts these food resources via negative trampling effects. We quantified acute trampling impacts on assemblages of upper shore invertebrates in a controlled experiment over a range of foot traffic intensities (up to 56 steps per square metre) on a temperate beach in Victoria, Australia. Trampling significantly altered assemblage structure (species composition and density) and was correlated with significant declines in invertebrate abundance and species richness. Trampling effects were strongest for rare species. In heavily trafficked plots the abundance of sand hoppers (Amphipoda), a principal prey item of threatened Hooded Plovers breeding on this beach, was halved. In contrast to the consistently strong effects of trampling, natural habitat attributes (e.g. sediment grain size, compactness) were much less influential predictors. If acute suppression of invertebrates caused by trampling, as demonstrated here, is more widespread on beaches it may constitute a significant threat to endangered vertebrates reliant on these invertebrates. This calls for a re-thinking of conservation actions by considering active management of food resources, possibly through enhancement of wrack or direct augmentation of prey items to breeding territories. PMID:27564550

  5. Taxonomic Review of the Orders Mysida and Stygiomysida (Crustacea, Peracarida)

    PubMed Central

    2015-01-01

    The order Mysida (2 families, 178 genera, 1132 species) contains species across a broad range of habitats, such as subterranean, fresh, brackish, coastal, and surface to deep-sea habitats. The Stygiomysida (2 families, 2 genera, 16 species), however, are found primarily in subterranean waters, but always in waters with a marine influence. The Mysida and Stygiomysida body is divided into three main regions: cephalon, thorax, and abdomen. They are shrimp-like in appearance, containing morphological features earlier referred to as defining a "caridoid facies". The shrimp-like morphology was to some extent diagnostic for the historic Decapod taxon Schizopoda, containing the Nebalia, Mysida, Lophogastrida, and Euphausiacea. In 1904 the concept of Schizopoda was abandoned, and the Mysidacea (Mysida and Lophogastrida) along with Cumacea, Amphipoda, Isopoda, and Tanaidacea were placed in a new taxon, the Peracarida. Later discoveries of groundwater mysids led to the establishment of Stygiomysida, but placement to either Lophogastrida or Mysida remained unclear. The presence of oostegites and absence of podobranchiae, coupled with non-statocyst bearing uropods have been used to classify the Stygiomysida as a primitive Mysida family, comparable to Petalophthalmidae. On the other hand, equally suggestive characters, but for a Lophogastrida affiliation, was suggested for the archaic foregut characters and again, non-statocyst bearing uropods. With the inclusion of DNA sequence data of ribosomal genes, sister group relationships between Stygiomysida, Lophogastrida, and Mictacea within the Peracarida are observed, which supports a classification of the Stygiomysida as a separate order removed from the Mysida. PMID:25927358

  6. Land use effect on invertebrate assemblages in Pampasic streams (Buenos Aires, Argentina).

    PubMed

    Solis, Marina; Mugni, Hernán; Hunt, Lisa; Marrochi, Natalia; Fanelli, Silvia; Bonetto, Carlos

    2016-09-01

    Agriculture and livestock may contribute to water quality degradation in adjacent waterbodies and produce changes in the resident invertebrate composition. The objective of the present study was to assess land use effects on the stream invertebrate assemblages in rural areas of the Argentine Pampa. The four sampling events were performed at six sites in four streams of the Pampa plain; two streams were sampled inside a biosphere reserve, and another one was surrounded by extensive livestock fields. The fourth stream was sampled at three sites; the upstream site was adjacent to agricultural plots, the following site was adjacent to an intensive livestock plot and the downstream site was adjacent to extensive breeding cattle plots. Higher pesticide concentrations were found at the site adjacent to agricultural plots and higher nutrient concentrations at the sites adjacent to agricultural and intensive breeding cattle plots. The invertebrate fauna were also different at these sites. Multivariate analysis showed a relationship between nutrient concentrations and taxonomic composition. Amphipoda (Hyalella curvispina) was the dominant group in the reserve and extensive breeding cattle sites, but was not present in the agricultural site. Also, Chironomidae were absent from the agricultural site while present at other sites. Gasteropoda (Biomphalaria peregrina), Zygoptera, and Hirudinea were dominant at the most impacted agricultural and intensive breeding cattle sites. PMID:27581006

  7. Evaluating macroinvertebrate population and community level effects in outdoor microcosms: Use of in situ bioassays and multivariate analysis

    SciTech Connect

    Shaw, J.L.; Manning, J.P.

    1996-05-01

    Evaluating toxicant effects on aquatic communities is difficult due to the ecological complexity at higher levels of organization. Two methods were assessed to improve the understanding of effects on macroinvertebrate communities in aquatic model ecosystems. First, in situ bioassay population effects were used to interpret effects at a higher organization level. Second, canonical discriminant analysis was used to investigate effects on community structure. In situ bioassays were conducted on six occasions in 17-m{sup 3} microcosms treated with copper sulfate. Macroinvertebrates occurring naturally in the microcosms were monitored. Epibenthic in situ bioassays were conducted using Caenis sp. (Ephemeroptera) and Hyalella azteca (Amphipoda) and a water column bioassay was conducted using Notonectidae (Hemiptera). Survival and growth were assessed after 3 d. Effects of copper on both notonectidae and Caenis were observed following application. However, the final Caenis epibenthic bioassays indicated that potential for recovery and survival was {ge}95%. Potential for recovery was less distinct in the water column bioassays. Copper effects also occurred on epibenthic macroinvertebrate populations and communities. Only four taxa, including Caenis, distinguished community differences among copper treatments soon after application. Later, communities showed similarities to the pretreatment bioassay. However, actual recovery was less apparent than the potential for recovery indicated by the bioassays, and community differences due to Caenis persisted.

  8. Biotic interactions affect the colonization behavior of aquatic detritivorous macroinvertebrates in a heterogeneous environment

    NASA Astrophysics Data System (ADS)

    Verschut, Thomas A.; Meineri, Eric; Basset, Alberto

    2015-05-01

    It has previously been suggested that macroinvertebrates actively search for suitable patches to colonize. However, it is not well understood how the spatial arrangement of patches can affect colonization rates. In this study, we determined the importance of the environmental factors (distance, connectivity and resource availability) for patch colonization in an experimental system using Gammarus aequicauda (Amphipoda), Lekanesphaera hookeri (Isopoda) and Ecrobia ventrosa (Gastropoda). Furthermore, we also assessed how the relative importance of each of these environmental factors differed in interactions between the three species. The single species experiments showed that distance was the most important factor for G. aequicauda and E. ventrosa. However, while E. ventrosa preferred patches close to the release point, G. aequicauda strongly preferred patches further from the release point. High resource availability was a strong determinant for the patch colonization of G. aequicauda and L. hookeri. Connectivity was only of moderate importance in the study system for L. hookeri and E. ventrosa. The effects of the environmental factors were strongly affected by interspecific interactions in the multispecies experiments. For G. aequicauda, the distance preference was lowered in the presence of E. ventrosa. Moreover, while for L. hookeri the effect of resource availability was ruled out by the species interactions, resource availability gained importance for E. ventrosa in the presence of any of the other species. Our results suggest a strong link between environmental factors and biotic interactions in the colonization of habitat patches and indicate that the effect of biotic interactions is especially important for species sharing similar traits.

  9. Disentangling the effects of local and regional factors on the thermal tolerance of freshwater crustaceans

    NASA Astrophysics Data System (ADS)

    Cottin, Delphine; Roussel, Damien; Foucreau, Natacha; Hervant, Frédéric; Piscart, Christophe

    2012-04-01

    In the global warming context, we compared the thermal tolerance of several populations of the crustacean Gammarus pulex (Amphipoda: Gammaridae) along a latitudinal thermal gradient in the Rhône Valley. To disentangle the effect of regional (North vs. South) and local (site-specific) factors, the ecophysiological responses of populations were investigated at two levels of biological organisation: whole organism level considering body size [critical thermal maximum (CTmax), mean speed of locomotion (MS), time mobile (TM)] and organelle function level [mitochondrial respiratory control ratios (RCRs)]. CTmax and RCRs, but not MS and TM, revealed a significantly higher thermal tolerance in southern populations compared to northern ones. Nevertheless, temperatures ≥ 30°C were deleterious for all populations, suggesting that populations located in the warmer limit of the species distribution will be more threatened by climate change as they live closer to their upper thermal limits. The strong differences observed between populations indicate that the species-level thermal tolerance used in predictive models may not be informative enough to study the impact of global warming on species distributions. This work also reveals that an appropriate choice of indicators is essential to study the consequences of global warming since the response of organisms at the whole body level can be influenced by local conditions.

  10. Preliminary biological measurement program in the Savannah River. Final report, 1 March-31 August 1982. Volume II

    SciTech Connect

    Specht, W.L.; Painter, W.B.

    1983-08-01

    A total of 131,815 macroinvertebrates were collected from meroplankton samples in the Savannah River and its tributary streams between 13 March and 29 August 1982. Fifty-three taxonomic groups, including 47 insect families and six non-insect taxa, were represented in the macroinvertebrate samples. Dipterans (true flies), particularly Chironomidae (midges) and Simuliidae (black flies) were the most abundant macroinvertebrate taxa at all transects. Other abundant taxa included Ephemeroptera (mayflies), Trichoptera (caddisflies), Amphipoda (scuds), Hydracarina (water mites) and nematode worms. When the invertebrate community was examined with respect to functional feeding groups, insect collectors were found to be the most abundant functional group. More invertebrate-taxa and higher densities of organisms were collected from the bottom drift samples than from the top of the water column, and more were collected from the center of the transects than from the bank areas. The results of the water quality analyses indicate that thermal discharges form Beaver Dam Creek, Four Mile Creek, and Pen Branch elevated the water temperature of the Savannah River approximately 1.6/sup 0/C between river Transects 6 and 9.

  11. Community structure and diversity of scavenging amphipods from bathyal to hadal depths in three South Pacific Trenches

    NASA Astrophysics Data System (ADS)

    Lacey, Nichola C.; Rowden, Ashley A.; Clark, Malcolm R.; Kilgallen, Niamh M.; Linley, Thomas; Mayor, Dan J.; Jamieson, Alan J.

    2016-05-01

    There are few biological datasets that span large bathymetric ranges with sufficient resolution to identify trends across the abyssal and hadal transition zone, particularly over multiple trenches. Here, scavenging Amphipoda were collected from three trenches in the South Pacific Ocean at bathyal to hadal depths. Diversity and community structure were examined from stations within the Kermadec Trench (1490-9908 m) and New Hebrides Trench (2000-6948 m) and additional data were included from the South Fiji Basin (4000 m) and Peru-Chile Trench (4602-8074 m). The hadal community structure of the Kermadec and New Hebrides trenches were distinct from the surrounding abyssal and bathyal depths and correlated to hydrostatic pressure and POC flux. Low POC flux in the New Hebrides Trench and South Fiji Basin best explained the dissimilarity in abyssal community structure from those of the disparate Kermadec and Peru-Chile trenches. POC flux also best explained patterns in hadal community structure with the Kermadec and New Hebrides Trench communities showing greater similarity to each other than to the eutrophic Peru-Chile Trench. Hydrostatic pressure was the strongest driver of intra-trench assemblage composition in all trench environments. A unimodal pattern of species diversity, peaking between 4000 and 5000 m, was best explained by hydrostatic pressure and temperature.

  12. Possible effects of global environmental changes on Antarctic benthos: a synthesis across five major taxa

    PubMed Central

    Ingels, Jeroen; Vanreusel, Ann; Brandt, Angelika; Catarino, Ana I; David, Bruno; De Ridder, Chantal; Dubois, Philippe; Gooday, Andrew J; Martin, Patrick; Pasotti, Francesca; Robert, Henri

    2012-01-01

    Because of the unique conditions that exist around the Antarctic continent, Southern Ocean (SO) ecosystems are very susceptible to the growing impact of global climate change and other anthropogenic influences. Consequently, there is an urgent need to understand how SO marine life will cope with expected future changes in the environment. Studies of Antarctic organisms have shown that individual species and higher taxa display different degrees of sensitivity to environmental shifts, making it difficult to predict overall community or ecosystem responses. This emphasizes the need for an improved understanding of the Antarctic benthic ecosystem response to global climate change using a multitaxon approach with consideration of different levels of biological organization. Here, we provide a synthesis of the ability of five important Antarctic benthic taxa (Foraminifera, Nematoda, Amphipoda, Isopoda, and Echinoidea) to cope with changes in the environment (temperature, pH, ice cover, ice scouring, food quantity, and quality) that are linked to climatic changes. Responses from individual to the taxon-specific community level to these drivers will vary with taxon but will include local species extinctions, invasions of warmer-water species, shifts in diversity, dominance, and trophic group composition, all with likely consequences for ecosystem functioning. Limitations in our current knowledge and understanding of climate change effects on the different levels are discussed. PMID:22423336

  13. Comparative analyses of olfactory systems in terrestrial crabs (Brachyura): evidence for aerial olfaction?

    PubMed

    Krieger, Jakob; Braun, Philipp; Rivera, Nicole T; Schubart, Christoph D; Müller, Carsten H G; Harzsch, Steffen

    2015-01-01

    Adaptations to a terrestrial lifestyle occurred convergently multiple times during the evolution of the arthropods. This holds also true for the "true crabs" (Brachyura), a taxon that includes several lineages that invaded land independently. During an evolutionary transition from sea to land, animals have to develop a variety of physiological and anatomical adaptations to a terrestrial life style related to respiration, reproduction, development, circulation, ion and water balance. In addition, sensory systems that function in air instead of in water are essential for an animal's life on land. Besides vision and mechanosensory systems, on land, the chemical senses have to be modified substantially in comparison to their function in water. Among arthropods, insects are the most successful ones to evolve aerial olfaction. Various aspects of terrestrial adaptation have also been analyzed in those crustacean lineages that evolved terrestrial representatives including the taxa Anomala, Brachyura, Amphipoda, and Isopoda. We are interested in how the chemical senses of terrestrial crustaceans are modified to function in air. Therefore, in this study, we analyzed the brains and more specifically the structure of the olfactory system of representatives of brachyuran crabs that display different degrees of terrestriality, from exclusively marine to mainly terrestrial. The methods we used included immunohistochemistry, detection of autofluorescence- and confocal microscopy, as well as three-dimensional reconstruction and morphometry. Our comparative approach shows that both the peripheral and central olfactory pathways are reduced in terrestrial members in comparison to their marine relatives, suggesting a limited function of their olfactory system on land. We conclude that for arthropod lineages that invaded land, evolving aerial olfaction is no trivial task. PMID:26713228

  14. [Abundance and biomass of meiobenthos in Lingdingyang Bay of Pearl River Estuary].

    PubMed

    Zhang, Jing-huai; Gao, Yang; Fang, Hong-da

    2011-10-01

    An investigation was conducted on the meiobenthic abundance and biomass in the Lingdingyang Bay of Pearl River Estuary in July-August 2006 (summer), April 2007 (spring), and October 2007 (autumn). A total of 15 meiobenthic groups were recorded, including Nematoda, Copepoda, Polychaeta, Ostracoda, Kinorhyncha, Amphipoda, Cumacea, Tanaidacea, Gnathostomulida, Nemertea, Gastropoda, Bivalvia, Sipuncula, Echiura, and other unidentified taxa. The average abundance of the meiobenthos in spring, summer, and autumn was 272.1 +/- 281.9, 165.1 +/- 147.1 and 246. 4 +/- 369.3 ind 10 cm(-2), and Nematoda was the most dominant group in abundance, accounting for 86.8%, 83.5%, and 93.4% of the total, respectively, followed by Polychaeta, and benthic Copepoda. The meiobenthic abundance had an uneven vertical distribution. 54.1% of the meibenthos were in 0-2 cm sediments, 35.2% were in 2-5 cm sediments, and 10.8% were in 5-10 cm sediments. 87.4% of nematodes were distributed in 0-5 cm sediments. The average biomass of the meiobenthos in spring, summer, and autumn was 374.6 +/- 346.9, 274.1 +/- 352.2, and 270.8 +/- 396.0 microg 10 cm(-2), and Polychaeta was the most dominant group in biomass, accounting for 30.1%, 46.7% and 46.0%, respectively, followed by Nematoda (25.2%, 20.1%, and 34.0%), and Ostracoda (20.6%, 15.3%, and 14.8%). The horizontal distribution of the meiobenthos had a trend of increasing from north to south, and being higher at east than at west. The meiobenthic abundance and biomass had significant positive correlations with water depth. PMID:22263483

  15. Natural disturbance shapes benthic intertidal macroinvertebrate communities of high latitude river deltas

    USGS Publications Warehouse

    Churchwell, Roy T.; Kendall, Steve J.; Blanchard, Amy L.; Dunton, Kenneth H.; Powell, Abby N.

    2016-01-01

    Unlike lower latitude coastlines, the estuarine nearshore zones of the Alaskan Beaufort Sea are icebound and frozen up to 9 months annually. This annual freezing event represents a dramatic physical disturbance to fauna living within intertidal sediments. The main objectives of this study were to describe the benthic communities of Beaufort Sea deltas, including temporal changes and trophic structure. Understanding benthic invertebrate communities provided a baseline for concurrent research on shorebird foraging ecology at these sites. We found that despite continuous year-to-year episodes of annual freezing, these estuarine deltas are populated by a range of invertebrates that represent both marine and freshwater assemblages. Freshwater organisms like Diptera and Oligochaeta not only survive this extreme event, but a marine invasion of infaunal organisms such as Amphipoda and Polychaeta rapidly recolonizes the delta mudflats following ice ablation. These delta sediments of sand, silt, and clay are fine in structure compared to sediments of other Beaufort Sea coastal intertidal habitats. The relatively depauperate invertebrate community that ultimately develops is composed of marine and freshwater benthic invertebrates. The composition of the infauna also reflects two strategies that make life on Beaufort Sea deltas possible: a migration of marine organisms from deeper lagoons to the intertidal and freshwater biota that survive the 9-month ice-covered period in frozen sediments. Stable isotopic analyses reveal that both infaunal assemblages assimilate marine and terrestrial sources of organic carbon. These results provide some of the first quantitative information on the infaunal food resources of shallow arctic estuarine systems and the long-term persistence of these invertebrate assemblages. Our data help explain the presence of large numbers of shorebirds in these habitats during the brief summer open-water period and their trophic importance to migrating

  16. Macro-Invertebrate Decline in Surface Water Polluted with Imidacloprid

    PubMed Central

    Van Dijk, Tessa C.; Van Staalduinen, Marja A.; Van der Sluijs, Jeroen P.

    2013-01-01

    Imidacloprid is one of the most widely used insecticides in the world. Its concentration in surface water exceeds the water quality norms in many parts of the Netherlands. Several studies have demonstrated harmful effects of this neonicotinoid to a wide range of non-target species. Therefore we expected that surface water pollution with imidacloprid would negatively impact aquatic ecosystems. Availability of extensive monitoring data on the abundance of aquatic macro-invertebrate species, and on imidacloprid concentrations in surface water in the Netherlands enabled us to test this hypothesis. Our regression analysis showed a significant negative relationship (P<0.001) between macro-invertebrate abundance and imidacloprid concentration for all species pooled. A significant negative relationship was also found for the orders Amphipoda, Basommatophora, Diptera, Ephemeroptera and Isopoda, and for several species separately. The order Odonata had a negative relationship very close to the significance threshold of 0.05 (P = 0.051). However, in accordance with previous research, a positive relationship was found for the order Actinedida. We used the monitoring field data to test whether the existing three water quality norms for imidacloprid in the Netherlands are protective in real conditions. Our data show that macrofauna abundance drops sharply between 13 and 67 ng l−1. For aquatic ecosystem protection, two of the norms are not protective at all while the strictest norm of 13 ng l−1 (MTR) seems somewhat protective. In addition to the existing experimental evidence on the negative effects of imidacloprid on invertebrate life, our study, based on data from large-scale field monitoring during multiple years, shows that serious concern about the far-reaching consequences of the abundant use of imidacloprid for aquatic ecosystems is justified. PMID:23650513

  17. Mesozooplankton and copepod community structures in the southern East China Sea: the status during the monsoonal transition period in September

    NASA Astrophysics Data System (ADS)

    Tseng, Li-Chun; Dahms, Hans-Uwe; Chen, Qing-Chao; Hwang, Jiang-Shiou

    2012-12-01

    A field sampling was conducted before the onset of the northeasterly monsoon to investigate the copepod community composition during the monsoon transition period at the northern coast of Taiwan (East China Sea). In total, 22 major mesozooplankton taxa were found, with the Calanoida (relative abundance: 66.36%) and Chaetognatha (9.44%) being the most abundant. Mesozooplankton densities ranged between 226.91 and 2162.84 individuals m-3 (mean ± SD: 744.01 ± 631.5 individuals m-3). A total of 49 copepod species were identified, belonging to 4 orders, 19 families, and 30 genera. The most abundant species were: Temora turbinata (23.50%), Undinula vulgaris (17.92%), and Acrocalanus gibber (14.73%). The chaetognath Flaccisagitta enflata occurred at all 8 sampling stations, providing a 95% portion of the overall chaetognath contribution. Amphipoda were abundant at stations 4 and 5, with Hyperioides sibaginis and Lestigonus bengalensis being dominant, and comprising about 50% of all amphipods. Chaetognath abundance showed a significantly negative correlation with salinity ( r = 0.77, p = 0.027), whereas mesozooplankton group numbers had a significantly positive correlation with salinity ( r = 0.71, p = 0.048). Densities of four copepod species ( Calanus sinicus, Calocalanus pavo, Calanopia elliptica and Labidocera acuta) showed a significantly negative correlation with seawater temperature. Communities of mesozooplankton and copepods of northern Taiwan varied spatially with the distance to land. The results of this study provide evidence for the presence of C. sinicus in the coastal area of northern Taiwan during the early northeast monsoon transition period in September.

  18. Islands beneath islands: phylogeography of a groundwater amphipod crustacean in the Balearic archipelago

    PubMed Central

    2011-01-01

    Background Metacrangonyctidae (Amphipoda, Crustacea) is an enigmatic continental subterranean water family of marine origin (thalassoid). One of the species in the genus, Metacrangonyx longipes, is endemic to the Balearic islands of Mallorca and Menorca (W Mediterranean). It has been suggested that the origin and distribution of thalassoid crustaceans could be explained by one of two alternative hypotheses: (1) active colonization of inland freshwater aquifers by a marine ancestor, followed by an adaptative shift; or (2) passive colonization by stranding of ancestral marine populations in coastal aquifers during marine regressions. A comparison of phylogenies, phylogeographic patterns and age estimations of clades should discriminate in favour of one of these two proposals. Results Phylogenetic relationships within M. longipes based on three mitochondrial DNA (mtDNA) and one nuclear marker revealed five genetically divergent and geographically structured clades. Analyses of cytochrome oxidase subunit 1 (cox1) mtDNA data showed the occurrence of a high geographic population subdivision in both islands, with current gene flow occurring exclusively between sites located in close proximity. Molecular-clock estimations dated the origin of M. longipes previous to about 6 Ma, whereas major cladogenetic events within the species took place between 4.2 and 2.0 Ma. Conclusions M. longipes displayed a surprisingly old and highly fragmented population structure, with major episodes of cladogenesis within the species roughly correlating with some of the major marine transgression-regression episodes that affected the region during the last 6 Ma. Eustatic changes (vicariant events) -not active range expansion of marine littoral ancestors colonizing desalinated habitats-explain the phylogeographic pattern observed in M. longipes. PMID:21791038

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

    SciTech Connect

    Trevorrow, M.V.; Tanaka, Yuji

    1997-01-01

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

  20. Temporal and spatial distribution of the meiobenthic community in Daya Bay, South China Sea

    NASA Astrophysics Data System (ADS)

    Tang, L.; Li, H. X.; Yan, Y.

    2012-04-01

    Spatial and temporal biodiversity patterns of the meiobenthos were studied for the first time in Daya Bay, which is a tropical semi-enclosed basin located in the South China Sea. The abundance, biomass, and composition of the meiobenthos and the basic environmental factors in the bay were investigated. The following 19 taxonomic groups were represented in the meiofauna: Nematoda, Copepoda, Polychaeta, Oligochaeta, Kinorhyncha, Gastrotricha, Ostracoda, Bivalvia, Turbellaria, Nemertinea, Sipuncula, Hydroida, Amphipoda, Cumacea, Halacaroidea, Priapulida, Echinodermata, Tanaidacea, and Rotifera. Total abundance and biomass of the meiobenthos showed great spatial and temporal variation, with mean values of 993.57 ± 455.36 ind cm-2 and 690.51 ± 210.64 μg 10 cm-2, respectively. Nematodes constituted 95.60 % of the total abundance and thus had the greatest effect on meiofauna quantity and distribution, followed by copepods (1.55 %) and polychaetes (1.39 %). Meiobenthos abundance was significantly negatively correlated with water depth at stations (r=-0.747, P<0.05) and significantly negatively correlated with silt-clay content (r=-0.516, P<0.01) and medium diameter (r=-0.499, P<0.01) of the sediment. Similar results were found for correlations of biomass and abundance of nematodes with environmental parameters. Polychaete abundance was positively correlated with the bottom water temperature (r=0.456, P<0.01). Meiobenthos abundance differed significantly among seasons (P<0.05), although no significant difference among stations and the interaction of station × season was detected by two-way ANOVA. In terms of vertical distribution, most of the meiobenthos was found in the surface layer of sediment. This pattern was apparent for nematodes and copepods, but a vertical distribution pattern for polychaetes was not as obvious. Based on the biotic indices and analyses of their correlations and variance, the diversity of this community was likely to be influenced by

  1. [Diet composition and seasonal variation in feeding habits of Collichthy lucidus in Yangtze Estuary, China].

    PubMed

    Wang, Jian-feng; Zhao, Feng; Song, Chao; Yang, Gang; Hou, Jun-li; Zhuang, Ping

    2016-01-01

    Spiny head croaker (Collichthy lucidus) is an important bottom fish distributing from the East China Sea to the Yellow Sea. In order to investigate the seasonal variation in diet composition and feeding habits, a total of 270 specimens were collected in the Yangtze Estuary from November, 2013 to August, 2014, and analyzed by using the stomach contents analysis method. The importance of different prey items was evaluated by the frequency of occurrence, abundance and mass followed by using these data to calculate the index of relative importance (IRI) and the index of preponderance (Ip) for each taxonomic category. The results showed that the diet of C. lucidus consisted of 30 species belonging to 8 orders, in which shrimps, with 38.5 IRI% and 79.1 Ip values, was the most important prey species. The followings were Mysidacea and Amphipoda. The dominant species in the diet of C. lucidus were Palaemon gravieri, Exopalaemon annandalei, E. carinicauda, Acanthomysis longirostris, A. brevirostris, Synidotea laevidorsalis and Calanus sinicus. The dominant species in the diet varied in different seasons. P. gravieri, E. annandalei and A. brevirostris were dominant species in spring and summer, A. longirostris, A. brevirostris and E. carinicauda in autumn, and P. gravieri, C. sinicus and Pesudeuphausia sinica in winter. There was 10.4% of total samples with empty stomachs, and the highest percent appeared in winter, and the lowest in autumn. The mean stomach fullness index of the whole samples was 0.6%, with the highest found in spring, the lowest in winter, indicating the feeding activity of C. lucidus varied significantly among seasons. PMID:27228621

  2. Macro-invertebrate decline in surface water polluted with imidacloprid.

    PubMed

    Van Dijk, Tessa C; Van Staalduinen, Marja A; Van der Sluijs, Jeroen P

    2013-01-01

    Imidacloprid is one of the most widely used insecticides in the world. Its concentration in surface water exceeds the water quality norms in many parts of the Netherlands. Several studies have demonstrated harmful effects of this neonicotinoid to a wide range of non-target species. Therefore we expected that surface water pollution with imidacloprid would negatively impact aquatic ecosystems. Availability of extensive monitoring data on the abundance of aquatic macro-invertebrate species, and on imidacloprid concentrations in surface water in the Netherlands enabled us to test this hypothesis. Our regression analysis showed a significant negative relationship (P<0.001) between macro-invertebrate abundance and imidacloprid concentration for all species pooled. A significant negative relationship was also found for the orders Amphipoda, Basommatophora, Diptera, Ephemeroptera and Isopoda, and for several species separately. The order Odonata had a negative relationship very close to the significance threshold of 0.05 (P = 0.051). However, in accordance with previous research, a positive relationship was found for the order Actinedida. We used the monitoring field data to test whether the existing three water quality norms for imidacloprid in the Netherlands are protective in real conditions. Our data show that macrofauna abundance drops sharply between 13 and 67 ng l(-1). For aquatic ecosystem protection, two of the norms are not protective at all while the strictest norm of 13 ng l(-1) (MTR) seems somewhat protective. In addition to the existing experimental evidence on the negative effects of imidacloprid on invertebrate life, our study, based on data from large-scale field monitoring during multiple years, shows that serious concern about the far-reaching consequences of the abundant use of imidacloprid for aquatic ecosystems is justified. PMID:23650513

  3. Compound-Specific Amino Acid Isotopic Analysis of Benthic Food Webs in the Chukchi Sea

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Cooper, L. W.; Biasatti, D. M.; Grebmeier, J. M.

    2014-12-01

    The Chukchi Sea is known for locally high standing stocks of benthic macrofauna and strong coupling between pelagic-benthic components of the ecosystem. However, benthic food structure is not fully understood, due to varied sources of particulate organic matter (POM) and the high diversity of benthic invertebrates. We provide the first demonstration of the application of compound-specific amino acid isotope analysis to study the dietary sources and trophic structure for this Arctic marginal sea. About 20 stations in Chukchi Sea were sampled during cruises in August of 2012 and 2013. At each station, phytoplankton, POM and benthic fauna were collected, processed and analyzed using GC-C-IRMS (gas chromatography-combustion-isotope ratio mass spectrometry). Among benthic fauna, dominant species included the following taxonomic groups: Ophiuroidea, Amphipoda, Polychaeta, Gastropoda, Bivalvia, and Cnidaria. The benthic fauna showed similar patterns of individual amino acid δ13C, with glycine the most enriched in 13C and leucine the most depleted in 13C. Specific amino acids including phenylalanine showed spatial variability in δ13C and δ15N values within the sampled area, indicating contributions of different dietary sources including phytoplankton, sea ice algae, benthic algae and terrestrial organic materials. δ15N values of individual amino acids such as the difference between glutamic acid and phenylalanine, i.e. Δ15Nglu-phe (δ15Nglu - δ15Nphe), were also used to identify trophic levels of benthic invertebrates relative to estimates available from bulk δ15N values. These data will ultimately be used to evaluate the spatial variability of organic carbon sources and trophic level interactions of dominant benthic species in the Chukchi Sea.

  4. The role of alternate hosts in the ecology and life history of Hematodinium sp., a parasitic dinoflagellate of the blue crab (Callinectes sapidus).

    PubMed

    Lohan, Katrina M Pagenkopp; Reece, Kimberly S; Miller, Terrence L; Wheeler, Kersten N; Small, Hamish J; Shields, Jeffrey D

    2012-02-01

    Hematodinium sp. infections are relatively common in some American blue crab (Callinectes sapidus) populations in estuaries of the western Atlantic Ocean. Outbreaks of disease caused by Hematodinium sp. can be extensive and can cause substantial mortalities in blue crab populations in high salinities. We examined several species of crustaceans to determine if the same species of Hematodinium that infects C. sapidus is found in other crustaceans from the same localities. Over a 2-yr period, 1,829 crustaceans were collected from the Delmarva Peninsula, Virginia, examined for the presence of infections. A portion of the first internal transcribed spacer (ITS1) region of the ribosomal RNA (rRNA) gene complex from Hematodinium sp. was amplified and sequences were compared among 35 individual crustaceans putatively infected with the parasite, as determined by microscopic examination, and 4 crustaceans putatively infected based only on PCR analysis. Of the 18 crustacean species examined, 5 were infected with Hematodinium sp. after microscopic examination and PCR analysis, including 3 new host records, and an additional species was positive only via PCR analysis. The ITS1 rRNA sequences of Hematodinium sp. from the infected crustaceans were highly similar to each other and to that reported from C. sapidus (>98%). The similarity among these ITS1 sequences and similarities in the histopathology of infected hosts is evidence that the same species of Hematodinium found in C. sapidus infects a broad range of crustaceans along the Delmarva Peninsula. Our data indicate that the species of Hematodinium found in blue crabs from estuaries along the east coast of North America is a host generalist, capable of infecting hosts in different families within the Order Decapoda. Additionally, evidence indicates that it may be capable of infecting crustaceans within the Order Amphipoda. PMID:21812642

  5. Investigating the emerging role of comparative proteomics in the search for new biomarkers of metal contamination under varying abiotic conditions.

    PubMed

    Vellinger, Céline; Sohm, Bénédicte; Parant, Marc; Immel, Françoise; Usseglio-Polatera, Philippe

    2016-08-15

    This study aims at investigating the potential use of comparative proteomics as a multi-marker approach of metal contamination, taking into account the potential confounding effect of water temperature. The major objective was to identify combinations of proteins specifically responding to a given metal, even if included in a metal mixture. The diagnostic approach was performed via the comparative analysis of protein expression on spot mapping provided by adult males of Gammarus pulex (Amphipoda, Crustacea) respectively exposed to arsenate (As), cadmium (Cd) or a binary mixture of these metals (AsCd) at three realistic temperatures (5, 10 and 15°C). Proteomic expression analysis was performed by Differential in-Gel Electrophoresis (2D-DiGE), and completed by an adapted inferential statistical approach. Combinations of under/over-expressed protein spots discriminated the metal identity. However, none of these spots discriminated both the individual metal effect (As or Cd) and its effect in metal mixture (AsCd) whatever the tested temperature. Some limits of the two-dimensional analysis of protein spot maps in G. pulex have been highlighted: (i) the presence of contaminating peptides and/or abundant "déja-vu" proteins which can mask the responses of other proteins of interest or (ii) the presence of post-translational modifications. An optimization of the experimental design (especially during the sample preparation) has been described for future investigations. This study has also highlighted (i) the importance of precisely identifying the protein spots of interest to avoid erroneous interpretations in terms of action mechanisms of chemicals and (ii) the importance of working under controlled laboratory conditions with a temperature close to 10°C. In such conditions, we have demonstrated a higher impact of As than Cd on the energetic metabolism of Gammarus. This As impact is reduced in AsCd mixture confirming the antagonistic interaction of this binary mixture

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

    PubMed Central

    Best, Rebecca J.; Stachowicz, John J.

    2013-01-01

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

  7. 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

  8. An evolutionary analysis of flightin reveals a conserved motif unique and widespread in Pancrustacea.

    PubMed

    Soto-Adames, Felipe N; Alvarez-Ortiz, Pedro; Vigoreaux, Jim O

    2014-01-01

    Flightin is a thick filament protein that in Drosophila melanogaster is uniquely expressed in the asynchronous, indirect flight muscles (IFM). Flightin is required for the structure and function of the IFM and is indispensable for flight in Drosophila. Given the importance of flight acquisition in the evolutionary history of insects, here we study the phylogeny and distribution of flightin. Flightin was identified in 69 species of hexapods in classes Collembola (springtails), Protura, Diplura, and insect orders Thysanura (silverfish), Dictyoptera (roaches), Orthoptera (grasshoppers), Pthiraptera (lice), Hemiptera (true bugs), Coleoptera (beetles), Neuroptera (green lacewing), Hymenoptera (bees, ants, and wasps), Lepidoptera (moths), and Diptera (flies and mosquitoes). Flightin was also found in 14 species of crustaceans in orders Anostraca (water flea), Cladocera (brine shrimp), Isopoda (pill bugs), Amphipoda (scuds, sideswimmers), and Decapoda (lobsters, crabs, and shrimps). Flightin was not identified in representatives of chelicerates, myriapods, or any species outside Pancrustacea (Tetraconata, sensu Dohle). Alignment of amino acid sequences revealed a conserved region of 52 amino acids, referred herein as WYR, that is bound by strictly conserved tryptophan (W) and arginine (R) and an intervening sequence with a high content of tyrosines (Y). This motif has no homologs in GenBank or PROSITE and is unique to flightin and paraflightin, a putative flightin paralog identified in decapods. A third motif of unclear affinities to pancrustacean WYR was observed in chelicerates. Phylogenetic analysis of amino acid sequences of the conserved motif suggests that paraflightin originated before the divergence of amphipods, isopods, and decapods. We conclude that flightin originated de novo in the ancestor of Pancrustacea > 500 MYA, well before the divergence of insects (~400 MYA) and the origin of flight (~325 MYA), and that its IFM-specific function in Drosophila is a more

  9. Distribution of benthic marine invertebrates at northern latitudes ― An evaluation applying multi-algorithm species distribution models

    NASA Astrophysics Data System (ADS)

    Meißner, Karin; Fiorentino, Dario; Schnurr, Sarah; Martinez Arbizu, Pedro; Huettmann, Falk; Holst, Sabine; Brix, Saskia; Svavarsson, Jörundur

    2014-01-01

    Different techniques of species distribution modeling were applied to evaluate the distribution of eight benthic marine species in Icelandic waters. The species examined were Symplectoscyphus tricuspidatus, Stegopoma plicatile (both Hydrozoa), Prionospio cirrifera, Amphicteis gunneri (both Polychaeta), Desmosoma strombergi, Eurycope producta (both Isopoda), Andaniella pectinata and Harpinia crenulata (both Amphipoda). Information on 13 environmental variables (temperature mean, temperature mean SD, temperature minimum, temperature maximum, salinity mean, salinity mean SD, oxygen content, particulate organic carbon, seasonal variation index, bottom roughness, sediment thickness, acidification) and records of occurrences of these eight species was collated in an ArcGIS project. Modeling methods applied were MARS, TreeNet, and MaxENT. According to area under the receiver operating curve (AUC) model assessment values, models with moderate to outstanding discriminatory power were found for all species. There was a good overlap in the overall pattern of prediction for most species independent on the modeling technique. Among the three applied techniques MARS seemed to generalize most whereas TreeNet predictions very precisely reflected information from the training data set. The distribution of the selected benthic invertebrate species in Icelandic waters could be linked to a variety of environmental factors related to oceanography, seabed topography and human impact. Their multivariate interactions acted as a structuring force of species distribution, instead of just their one by one individual influence. The selected predictors varied between the different models for the same species. They substituted each other in different models. The expected distribution of the examined species was mapped for a seascape of known environmental settings. Such maps will serve as excellent references in future impact studies and enable the detection of changes in the distribution of

  10. Comparative analyses of olfactory systems in terrestrial crabs (Brachyura): evidence for aerial olfaction?

    PubMed Central

    Krieger, Jakob; Braun, Philipp; Rivera, Nicole T.; Schubart, Christoph D.; Müller, Carsten H.G.

    2015-01-01

    Adaptations to a terrestrial lifestyle occurred convergently multiple times during the evolution of the arthropods. This holds also true for the “true crabs” (Brachyura), a taxon that includes several lineages that invaded land independently. During an evolutionary transition from sea to land, animals have to develop a variety of physiological and anatomical adaptations to a terrestrial life style related to respiration, reproduction, development, circulation, ion and water balance. In addition, sensory systems that function in air instead of in water are essential for an animal’s life on land. Besides vision and mechanosensory systems, on land, the chemical senses have to be modified substantially in comparison to their function in water. Among arthropods, insects are the most successful ones to evolve aerial olfaction. Various aspects of terrestrial adaptation have also been analyzed in those crustacean lineages that evolved terrestrial representatives including the taxa Anomala, Brachyura, Amphipoda, and Isopoda. We are interested in how the chemical senses of terrestrial crustaceans are modified to function in air. Therefore, in this study, we analyzed the brains and more specifically the structure of the olfactory system of representatives of brachyuran crabs that display different degrees of terrestriality, from exclusively marine to mainly terrestrial. The methods we used included immunohistochemistry, detection of autofluorescence- and confocal microscopy, as well as three-dimensional reconstruction and morphometry. Our comparative approach shows that both the peripheral and central olfactory pathways are reduced in terrestrial members in comparison to their marine relatives, suggesting a limited function of their olfactory system on land. We conclude that for arthropod lineages that invaded land, evolving aerial olfaction is no trivial task. PMID:26713228

  11. Altered performance of white sucker populations in the Manitouwadge chain of lakes is associated with changes in benthic macroinvertebrate communities as a result of copper and zinc contamination

    SciTech Connect

    Munkittrick, K.R.; Miller, P.A.; Barton, D.R.; Dixon, D.G. )

    1991-06-01

    White sucker (Catostomus commersoni) collected from the Manitouwadge chain of lakes show a lower growth rate and fecundity in lakes contaminated with copper and zinc from a mixed metal mine. This study evaluated whether the changes in performance of the fish were related to direct impacts of the metals or indirect impacts associated with changes in food availability. Concentrations of metals in the water and sediment of lakes in the Manitouwadge chain were elevated, relative to reference sites. The concentrations of Cu and Zn in the digesta of white sucker were significantly higher, as were the levels of both Cu and Zn in liver, kidney, and gill tissue. Muscle and spleen levels of Cu and Zn were significantly lower or not different from controls. Tissue levels were within the homeostatic range for Cu and Zn. However, the total density of invertebrates varied from greater than 25,000 m-2 at control sites to less than 13,000 m-2 at contaminated sites, and the number of genera recorded was more than 50% lower in shallow water samples. There was almost a complete absence of several invertebrate taxa at contaminated sites, including Plecoptera, Ephemeroptera, Odonata, Trichoptera, Amphipoda, and Unionidae. Diptera accounted for 78 to 96% of the total numbers of individuals at metal-contaminated sites as compared with 40 to 75% at the control sites. An analysis of white sucker stomach contents showed that the contents closely reflected the benthic composition observed in the natural substrate. Changes in food availability and feeding activity were correlated with previous changes documented in the growth, fecundity, and lipid levels of white sucker.

  12. Feeding ecology of the early life-history stages of two dominant gobiid species in the headwaters of a warm-temperate estuary

    NASA Astrophysics Data System (ADS)

    Wasserman, Ryan J.

    2012-08-01

    The diet and population structure of larval and early juvenile Glossogobius callidus and Redigobius dewaali (Gobiidae) were examined from the headwater region of the permanently open Great Fish Estuary along the south-east coast of southern Africa. Stomach contents of five selected size classes were sorted and identified to the lowest possible taxonomic level for each goby species. Using % Index of Relative Importance values, ontogenic shifts and dietary breadth were determined for each species as was dietary overlap between species. Numerically, both gobiid species showed similar temporal and spatial trends. Seasonal differences in catches were evident, although no numerical differences across sampled sites were found. A large degree of dietary overlap was found between the two species. The zooplanktonic diet showed a greater degree of ontogenic shift in R. dewaali than G. callidus, although similar trends were found for both. In both goby species, Calanoid sp. (Copepoda) generally decreased in importance across size classes, being the most important in the smallest size class whilst Corophium sp. (Amphipoda) increased in importance across size classes, being the least important at the smallest size classes. For both G. callidus and R. dewaali, Insecta contributed significantly to at least one of the five size classes. The larger size classes showed the least dietary overlap and the highest niche breadth. In addition, as is the case in many gobiids worldwide, the larger size classes of both sampled gobiid species consumed a broader prey size range. In conclusion, dietary overlap was largely similar between the young gobiids, suggesting that either food resources are not limiting, or niche separation is attributed to differences in foraging strategies. Ontogenic dietary shifts were however present for both gobiids with regard to prey items and prey size, suggesting a greater degree of foraging niche separation in adults of the species.

  13. Environmental Domains and Range-Limiting Mechanisms: Testing the Abundant Centre Hypothesis Using Southern African Sandhoppers

    PubMed Central

    Baldanzi, Simone; McQuaid, Christopher D.; Cannicci, Stefano; Porri, Francesca

    2013-01-01

    Predicting shifts of species geographical ranges is a fundamental challenge for conservation ecologists given the great complexity of factors involved in setting range limits. Distributional patterns are frequently modelled to “simplify” species responses to the environment, yet the central mechanisms that drive a particular pattern are rarely understood. We evaluated the distributions of two sandhopper species (Crustacea, Amphipoda, Talitridae), Talorchestia capensis and Africorchestia quadrispinosa along the Namibian and South African coasts, encompassing three biogeographic regions influenced by two different oceanographic systems, the Benguela and Agulhas currents. We aimed to test whether the Abundant Centre Hypothesis (ACH) can explain the distributions of these species’ abundances, sizes and sex ratios and examined which environmental parameters influence/drive these distributions. Animals were collected during a once-off survey at 29 sites over c.3500 km of coastline. The ACH was tested using a non-parametric constraint space analysis of the goodness of fit of five hypothetical models. Distance Based Linear Modelling (DistLM) was performed to evaluate which environmental traits influenced the distribution data. Abundance, size and sex ratio showed different patterns of distribution. A ramped model fitted the abundance (Ramped North) and size (Ramped South) distribution for A. quadrispinosa. The Inverse Quadratic model fitted the size distribution of T. capensis. Beach slope, salinity, sand temperature and percentage of detritus found on the shore at the time of collection played important roles in driving the abundance of A. quadrispinosa. T. capensis was mainly affected by salinity and the morphodynamic state of the beach. Our results provided only some support for the ACH predictions. The DistLM confirmed that the physical state of the beach is an important factor for sandy beach organisms. The effect of salinity and temperature suggest metabolic

  14. Colonisation of leaf litter by aquatic invertebrates in an Atlantic Forest stream.

    PubMed

    Oliveira, V C; Gonçalves, E A; Alves, R G

    2014-05-01

    Riparian vegetation along streams in the Atlantic Forest in Brazil contributes to the formation of a highly heterogeneous leaf litter in streambeds. To investigate the structure and composition of the aquatic invertebrate community during the process of leaf decomposition of two plant species present along the banks of the stream studied, 21 plastic mesh bags containing 2.5g (dry weight) of leaf matter from each species (Alchornea glandulosa (Vell) and Cabralea canjerana End. and Poeppig), for a total of 5.0g, were placed in the streambed. Three bags were removed after 3, 6, 9, 12, 24, 48 and 96 days. The taxonomic density was negatively correlated with the remaining weight. The high density of collector organisms, such as Chironomidae, Oligochaeta and Amphipoda, on the last day of incubation, probably occurred due to the increased amount of fine organic matter in the more advanced decomposition stages. The highest α diversity (Shannon-Wiener) values were observed for the 3rd and 96th days of the experiment, while the β diversity values showed that these days presented the highest variation in the taxonomic composition, thus presenting a different faunistic composition. This study showed that the trophic structure and composition of aquatic invertebrates changes during the decomposition of leaf litter. The faunistic abundance and diversity observed in this study indicate that the entrance of material from plants growing along streams provides favorable conditions for the colonisation and establishment of invertebrates in lower-order streams, and thus points to the need to preserve riparian vegetation. PMID:25166310

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

    PubMed

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

    2013-04-01

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

  16. When growth models are not universal: evidence from marine invertebrates

    PubMed Central

    Hirst, Andrew G.; Forster, Jack

    2013-01-01

    The accumulation of body mass, as growth, is fundamental to all organisms. Being able to understand which model(s) best describe this growth trajectory, both empirically and ultimately mechanistically, is an important challenge. A variety of equations have been proposed to describe growth during ontogeny. Recently, the West Brown Enquist (WBE) equation, formulated as part of the metabolic theory of ecology, has been proposed as a universal model of growth. This equation has the advantage of having a biological basis, but its ability to describe invertebrate growth patterns has not been well tested against other, more simple models. In this study, we collected data for 58 species of marine invertebrate from 15 different taxa. The data were fitted to three growth models (power, exponential and WBE), and their abilities were examined using an information theoretic approach. Using Akaike information criteria, we found changes in mass through time to fit an exponential equation form best (in approx. 73% of cases). The WBE model predominantly overestimates body size in early ontogeny and underestimates it in later ontogeny; it was the best fit in approximately 14% of cases. The exponential model described growth well in nine taxa, whereas the WBE described growth well in one of the 15 taxa, the Amphipoda. Although the WBE has the advantage of being developed with an underlying proximate mechanism, it provides a poor fit to the majority of marine invertebrates examined here, including species with determinate and indeterminate growth types. In the original formulation of the WBE model, it was tested almost exclusively against vertebrates, to which it fitted well; the model does not however appear to be universal given its poor ability to describe growth in benthic or pelagic marine invertebrates. PMID:23945691

  17. Abyssal macrofauna of the Kuril-Kamchatka Trench area (Northwest Pacific) collected by means of a camera-epibenthic sledge

    NASA Astrophysics Data System (ADS)

    Brandt, A.; Elsner, N. O.; Malyutina, M. V.; Brenke, N.; Golovan, O. A.; Lavrenteva, A. V.; Riehl, T.

    2015-01-01

    Abyssal macrofaunal composition of 21 epibenthic sledge hauls from twelve stations taken in the Kuril-Kamchatka Trench (KKT) and at the adjacent abyssal plain, Northwest Pacific, is presented. Sampling with the fine meshed epibenthic sledge yielded higher abundances and species richness than was reported from previous expeditions from board of RV Vityaz. In total 84,651 invertebrates were sampled with RV Sonne between July and September of 2012 (31,854 invertebrates if standardised for 1000 m2 trawled distances) from 41 taxa of different taxonomic ranks (15 phyla, 28 classes, 7 orders) were sampled from a trawled area of 53,708 m² and have been analyzed. Few taxa were frequent and most taxa were rare in the samples, twelve taxa occurred with more than 1% frequency. Of these, the Polychaeta were most abundant followed by the benthic Copepoda and Isopoda. Total numbers of individuals varied between stations and were highest with 4238 individuals at station 2-10 close to the KKT in 4865 m depth and lowest with 374 individuals at station 6-11 in 5305 m depth. At this station also the lowest number of taxa occurred (18 taxa) while the highest number occurred with 31 taxa at station 3-9 in 4991 m depth. Numbers of individuals decreased with increasing depth between 4830 and 5780 m. Crustaceans of the superorder Peracarida were one of the dominating taxa with four orders occurring frequently in most samples. In total, Isopoda were most important and occurred with 59% of all peracarid orders sampled, followed by Amphipoda with 21%, Tanaidacea with 11%, Cumacea with 9%, and Mysidacea with <1%. The communities of the stations (and hauls) of the KKT abyssal area differ in terms of taxon composition from each other. A cluster analysis (nMDS) performed for all sampled stations revealed no clear pattern of community similarity between stations or hauls. All hauls close to the trench (2-9 and 2-10 close to the eastern slope of the KKT; and 3-9 and 4-3 at the western slope) were

  18. Biodiversity of the Deep-Sea Benthic Fauna in the Sangihe-Talaud Region, Indonesia: Observations from the INDEX-SATAL 2010 Expedition

    NASA Astrophysics Data System (ADS)

    Herrera, S.; Munro, C.; Nganro, N.; Tunnicliffe, V.; Wirasantosa, S.; Sibert, E.; Hammond, S. R.; Bors, E.; Butterfield, D.; Holden, J. F.; Baker, E. T.; Sherrin, J.; Makarim, S.; Troa, R.; Shank, T. M.

    2010-12-01

    The benthic ecosystems found in the deep-sea promontories of Sangihe Talaud region were explored, between June and August 2010, using the ROV Little Hercules aboard the NOAA ship Okeanos Explorer. The Sangihe-Talaud region is part of the Coral Triangle (CT) an area known for harboring the most biodiverse shallow-water coral reefs in the world. Notwithstanding the significant research efforts that have been undertaken to catalog and protect the biodiversity of the CT prior this expedition, virtually nothing was known about the life inhabiting the deep sea. The high-resolution imagery obtained from the 27 ROV dives revealed remarkably high abundances and diversity of animal species, many of which appear to be novel. On hard bottom substrates, cold-water corals were the dominant sessile macrofauna, in terms of biomass, followed by glass sponges (Hexactinellida) and sea lilies (Crinoidea). The coral taxa observed in this area represent six large orders of cnidarians: antipatharians (black corals), scleractinians (stony corals), zoanthideans (gold corals), alcyonaceans (octocorals), pennatulaceans (sea pens), and anthoathecates (hydrocorals). Most sessile species, independently of their size class or taxonomic affiliation, harbor a wide variety of associated fauna. Brittle stars (Ophiuroidea), squat lobsters (Galatheoidea), shrimp (Caridea), amphipods (Amphipoda), anemones (Actinaria), zanthideans, barnacles (Cirripedia), hydroids (Hydrozoa) and worms (Polychaeta) are the animal groups most commonly found forming these associations. In contrast, soft bottom habitats were dominated by stalked sponges, sea pens, sea cucumbers (Holothuroidea) and brittle stars. Other conspicuous fauna include fish, hermit crabs (Paguridae), urchins (Echinoidea) and octopuses (Cephalopoda). The abundance of habitats generated by the high number of geological and biological features and depth ranges present in the deep coral triangle (e.g., ridges, seamounts, island margins, plains, and rock

  19. Zonation of benthic communities in a tropical tidal flat of north-east Australia

    NASA Astrophysics Data System (ADS)

    Dittmann, S.

    2000-02-01

    Tropical tidal flats are relatively less well-known marine ecosystems. Therefore, the distribution and abundance of infaunal organisms were surveyed in a tidal flat in the Haughton estuary, north-east Australia, testing several hypotheses on characteristics of intertidal faunal distributions. Using a stratified random sampling design, macrofauna, small macrofauna (mesofauna) and meiofauna were sampled at five sites along a transect from the high to the low intertidal in April and September 1991. In total, 77 macrobenthic species were recorded during this study, with polychaetes and crustaceans richest in species. While this species record was low compared to other tropical tidal flats, the low individual densities confirmed previous findings of lower abundances in tropical than temperate tidal flats. Along the transect, species densities were highest in the mid-intertidal muddy sand and sandflats, with values ranging from 2.9 to 7.6 species 177 cm -2 for macrofauna and from 2.2 to 3.8 species 10 cm -2 for mesofauna. At the Callianassa site in the mid-intertidal 35 species were recorded, while the lower sandflat site had the highest diversity ( H'=2.60). Macro- and mesofauna abundances were highest at the sandflat site (median values for macrofauna: 65 and 69 ind. 177 cm -2 in September and April, respectively, and 37 and 48 ind. 10 cm -2 for mesofauna). There was little variation between the two sampling dates, although single taxa occurred with significantly higher abundances in one of the two months. Polychaeta and Amphipoda were abundant at the sandflat and Callianassa site, juvenile bivalves were most frequent in the sandflat after a spatfall in September. There was no pronounced increase of suspension feeders in the lower intertidal, and deposit feeders dominated the fauna. Meiofauna was abundant throughout the intertidal with median values up to 310 ind. 5 cm -2. Their densities were highest in the lower intertidal and lowest at the transect site with

  20. Continental shelf benthos off Otago Peninsula, New Zealand

    NASA Astrophysics Data System (ADS)

    Probert, P. Keith; Wilson, John B.

    1984-09-01

    Benthic macrofauna of the continental shelf off Otago Peninsula, south-eastern New Zealand (45°51'S, 170°52'E) was surveyed by dredge sampling during 1973-1975. Numerical classification (Canberra metric coefficient and flexible sorting) was used to produce site groups and species groups, and three major benthic communities were recognised: a shallow-water (14-25 m) fauna inhabiting well-sorted fine sand, a mid-shelf fauna (concentrated in the depth range 50-76 m) associated with sediments containing the greatest proportions of gravel and siltclay, and a predominantly sand-bottom fauna occurring mainly on the outer shelf (87-150 m). All station groups were dominated numerically by polychaetes (mean of 36·6-56% of individuals) with Mollusca (13·8-25%) or Crustacea (12·1-19·4%) the next most abundant group. The inshore sand fauna was the most distinct, characteristic elements being the trochid gastropod Antisolarium egenum, an amphipod of the genus Hippomedon and dense patches of the spionid polychaete Spiophanes bombyx. Diagnostic species of the mid-shelf mixed sediments were Lepidonotus jacksoni, Psammolyce antipoda, Lumbrineris brevicirra and Phyllamphicteis foliata (Polychaeta), Terenochiton otagoensis, Micrelenchus caelatus caelatus, Maoricolpus roseus roseus and Zegalerus tenuis (Mollusca), Ampelisca chiltoni (Amphipoda) and Amphipholis squamata (Ophiuroidea). Outer shelf sand stations were faunally less distinct, but among the more characteristic species were Euthalenessa fimbriata, Sigalion sp. and Euchone sp. (Polychaeta) and Gari stangeri (Bivalvia). Several abundant species were widely distributed among station groups, notably Nephtys macroura, Lumbrineris magalhaensis, Phyllochaetopterus socialis and Owenia fusiformis (Polychaeta) and Nucula nitidula and Tawera spissa (Bivalvia). Free-living lunulitiform Bryozoa of the genus Otionella were a characteristic component of inner and outer shelf sand faunas, and their inshore penetration probably marks

  1. Unexpectedly higher metazoan meiofauna abundances in the Kuril-Kamchatka Trench compared to the adjacent abyssal plains

    NASA Astrophysics Data System (ADS)

    Schmidt, Christina; Martínez Arbizu, Pedro

    2015-01-01

    We studied meiofauna standing stocks and community structure in the Kuril-Kamchatka Trench and its adjacent abyssal plains in the northwestern Pacific Ocean. In general, the Nematoda were dominant (93%) followed by the Copepoda (4%). Nematode abundances ranged from 87% to 96%; those of copepods from 2% to 7%. The most diverse deployment yielded 17 taxa: Acari, Amphipoda, Annelida, Bivalvia, Coelenterata, Copepoda, Cumacea, Gastrotricha, Isopoda, Kinorhyncha, Loricifera, Nematoda, Ostracoda, Priapulida, Tanaidacea, Tantulocarida, and Tardigrada. Nauplii were also present. Generally, the trench slope and the southernmost deployments had the highest abundances (850-1392 individuals/cm2). The results of non-metric multidimensional scaling indicated that these deployments were similar to each other in meiofauna community structure. The southernmost deployments were located in a zone of higher particulate organic carbon (POC) flux (g Corg m-2 yr-1), whereas the trench slope should have low POC flux due to depth attenuation. Also, POC and abundance were significantly correlated in the abyssal plains. This correlation may explain the higher abundances at the southernmost deployments. Lateral transport was also assumed to explain high meiofauna abundances on the trench slope. Abundances were generally higher than expected from model results. ANOSIM revealed significant differences between the trench slope and the northern abyssal plains, between the central abyssal plains and the trench slope, between the trench slope and the southern abyssal plains, between the central and the southern abyssal plains, and between the central and northern deployments. The northern and southern abyssal plains did not differ significantly. In addition, a U-test revealed highly significant differences between the trench-slope and abyssal deployments. The taxa inhabited mostly the upper 0-3 cm of the sediment layer (Nematoda 80-90%; Copepoda 88-100%). The trench-slope and abyssal did not differ

  2. A “Rosetta Stone” for metazoan zooplankton: DNA barcode analysis of species diversity of the Sargasso Sea (Northwest Atlantic Ocean)

    NASA Astrophysics Data System (ADS)

    Bucklin, Ann; Ortman, Brian D.; Jennings, Robert M.; Nigro, Lisa M.; Sweetman, Christopher J.; Copley, Nancy J.; Sutton, Tracey; Wiebe, Peter H.

    2010-12-01

    Species diversity of the metazoan holozooplankton assemblage of the Sargasso Sea, Northwest Atlantic Ocean, was examined through coordinated morphological taxonomic identification of species and DNA sequencing of a ˜650 base-pair region of mitochondrial cytochrome oxidase I (mtCOI) as a DNA barcode (i.e., short sequence for species recognition and discrimination). Zooplankton collections were made from the surface to 5,000 meters during April, 2006 on the R/V R.H. Brown. Samples were examined by a ship-board team of morphological taxonomists; DNA barcoding was carried out in both ship-board and land-based DNA sequencing laboratories. DNA barcodes were determined for a total of 297 individuals of 175 holozooplankton species in four phyla, including: Cnidaria (Hydromedusae, 4 species; Siphonophora, 47); Arthropoda (Amphipoda, 10; Copepoda, 34; Decapoda, 9; Euphausiacea, 10; Mysidacea, 1; Ostracoda, 27); and Mollusca (Cephalopoda, 8; Heteropoda, 6; Pteropoda, 15); and Chaetognatha (4). Thirty species of fish (Teleostei) were also barcoded. For all seven zooplankton groups for which sufficient data were available, Kimura-2-Parameter genetic distances were significantly lower between individuals of the same species (mean=0.0114; S.D. 0.0117) than between individuals of different species within the same group (mean=0.3166; S.D. 0.0378). This difference, known as the barcode gap, ensures that mtCOI sequences are reliable characters for species identification for the oceanic holozooplankton assemblage. In addition, DNA barcodes allow recognition of new or undescribed species, reveal cryptic species within known taxa, and inform phylogeographic and population genetic studies of geographic variation. The growing database of "gold standard" DNA barcodes serves as a Rosetta Stone for marine zooplankton, providing the key for decoding species diversity by linking species names, morphology, and DNA sequence variation. In light of the pivotal position of zooplankton in ocean

  3. Epifauna dynamics at an offshore foundation--implications of future wind power farming in the North Sea.

    PubMed

    Krone, Roland; Gutow, Lars; Joschko, Tanja J; Schröder, Alexander

    2013-04-01

    In the light of the introduction of thousands of large offshore wind power foundations into the North Sea within the next decades, this manuscript focuses on the biofouling processes and likely reef effects. The study explores the macrozoobenthos (biofouling) colonization at an offshore platform which is comparable to offshore wind turbine foundations. A total of 183 single samples were taken and the parameters water depth and time were considered comparing biofouling masses and communities. The blue mussel Mytilus edulis, Anthozoa and the Amphipoda Jassa spp. were the dominant species. The community from the 1 m zone and those from the 5 and 20-28 m zones can clearly be differentiated. The 10 m zone community represents the transition between the M. edulis dominated 1 m and 5 m zones and the Anthozoa dominated 20-28 m zone. In the future offshore wind farms, thousands of wind turbine foundations will provide habitat for a hard bottom fauna which is otherwise restricted to the sparse rocky habitats scattered within extensive sedimentary soft bottoms of the German Bight. However, offshore wind power foundations cannot be considered natural rock equivalents as they selectively increase certain natural hard bottom species. The surface of the construction (1280 m²) was covered by an average of 4300 kg biomass. This foundation concentrates on its footprint area (1024 m²) 35 times more macrozoobenthos biomass than the same area of soft bottom in the German exclusive economic zone (0.12 kg m(-2)), functioning as a biomass hotspot. Concerning the temporal biomass variation, we assume that at least 2700 kg biomass was exported on a yearly basis. 345 × 10(4) single mussel shells of different sizes were produced during the study period. It is anticipated that the M. edulis abundance will increase in the North Sea due to the expansion of the offshore wind farm development. This will result in the enhanced production of secondary hard substrate (mussel shells

  4. Brain architecture of the largest living land arthropod, the Giant Robber Crab Birgus latro (Crustacea, Anomura, Coenobitidae): evidence for a prominent central olfactory pathway?

    PubMed Central

    2010-01-01

    visual and mechanosensory skills that are comparable to those of marine Crustacea. Conclusions In parallel to previous behavioral findings that B. latro has aerial olfaction, our results indicate that their central olfactory pathway is indeed most prominent. Similar findings from the closely related terrestrial hermit crab Coenobita clypeatus suggest that in Coenobitidae, olfaction is a major sensory modality processed by the brain, and that for these animals, exploring the olfactory landscape is vital for survival in their terrestrial habitat. Future studies on terrestrial members of other crustacean taxa such as Isopoda, Amphipoda, Astacida, and Brachyura will shed light on how frequently the establishment of an aerial sense of olfaction evolved in Crustacea during the transition from sea to land. Amounting to ca. 1,000,000, the numbers of interneurons that analyse the olfactory input in B. latro brains surpasses that in other terrestrial arthropods, as e.g. the honeybee Apis mellifera or the moth Manduca sexta, by two orders of magnitude suggesting that B. latro in fact is a land-living arthropod that has devoted a substantial amount of nervous tissue to the sense of smell. PMID:20831795

  5. Ecological assessment of water quality in relation to hydrogeology in a shallow urban aquifer: Somesul Mic River aquifer (North-Western, Romania)

    NASA Astrophysics Data System (ADS)

    Iepure, Sanda; Marin, Constantin; Fekete, Alexandru; Rajka, Geza; Brad, Traian; Samsudean, Cristian

    2014-05-01

    (509.74 μg/l), As (3.87 μg/l), Se (5.07 μg/l), sulphates (549.9 μg/l) and nitrates (95.4 mg/l) downstream from industrial and agricultural lands. Only seven taxa, dominated by crustaceans, were found within the stygofaunal communities. Copepod stygoxene species (i.e., Megacyclops viridis Jurine, 1820, Diacyclops languidoides ssp.) accounts for almost 80% of the groundwater crustaceans, being abundant in samples from sites with elevated (94 μg/l) concentration of nitrates (thus indicating a high tolerance to this pollutant). Moreover, these species appear to be tolerant to high content of Cu (8.6 μg/l) and only slightly tolerant to Sr, Co, Ni, Ti and Pb (r>0.60; p>0.05). Conversely, the stygobites species Parastenocaris sp. (Harpacticoida), Bathynella sp. (Syncarida), Niphargus sp. (Amphipoda) and Ostracoda were rare and limited to boreholes were no significant trace metals contamination was detected, whereas nitrates reach a maximum level of 47.5 μg/l. Crustaceans abundance was linked to high content of total dissolved solids and elements such are Li, Na and Sr; whereas Cs and nitrites were detected to be harmful for crustacean development. The ecological attributes and sensitivity of styfogauna to contaminants makes them significant bioindicators for evaluating the ecological status of groundwater ecosystems and susceptible to get loss when aquifers quality is affected on long term.