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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

    2013-10-31

    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.

  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. New member of the family Niphargidae from Croatia, Niphargus radzai, sp. n. (contribution to the knowledge of the Amphipoda 273).

    PubMed

    Karaman, Gordan S

    2014-06-05

    One new species of the genus Niphargus Schiödte, 1849 (Amphipoda, Gammaridea, Niphargidae) from the subterranean waters (springs) above Ravno Vrdovo in Dinara Mountain, Croatia, is described. Niphargus radzai sp. n. belongs to the artificial group within Niphargus with elevated number of setae along outer margin of dactylus in gnathopods 1 and 2 and dactylus of some or all pereopods provided with additional spines along inner margin. The differences between N. radzai and some other similar members of this group of taxa are discussed.

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

    PubMed

    Azman, B A R; Melvin, C W H

    2011-03-24

    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.

  6. 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

  7. Thaumatelsonella kingelepha, eine neue Gattung und Art aus der Antarktis (Crustacea: Amphipoda: Gammaridea: Stenothoidae)

    NASA Astrophysics Data System (ADS)

    Rauschert, M.; Andres, H. G.

    1991-03-01

    A taxonomic study on stenothoid amphipods from the area of South Shetland Islands (Antarctica), led to the description of Thaumatelsonella kingelepha gen. and sp. nov. The systematic position of Pseudothaumatelson cyproides Nicholls, 1938 is discussed, as the redescription by Bellan-Santini & Ledoyer (1986) based on the first recovery of that species included differences from the diagnosis of the genus.

  8. 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

  9. 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

    2016-06-30

    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.

  10. A new genus and species of Platyischnopidae (Amphipoda: Gammaridea) from the Argentine sea, South-West Atlantic ocean.

    PubMed

    Chiesa, Ignacio L; Alonso, Gloria M

    2014-05-30

    The family Platyischnopidae is herein reported for the first time in the Argentine Sea, South-West Atlantic Ocean. A new genus and species, Platyisao holodividum gen. et. sp. nov., collected off the coast of Buenos Aires and Río Negro provinces, is fully described and illustrated. Platyisao gen. nov. is distinguished from the eight other genera of Platyischnopidae by the gnathopods subchelate, and the telson elongate, completely cleft. In addition, the distribution of Tiburonella viscana (Barnard J.L., 1964), up to now known in the South-West Atlantic Ocean from Brazilian waters, is extended to the coast off Buenos Aires province, Argentina.

  11. 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.

  12. On Eulimnogammarus messerschmidtii, sp. n. (Amphipoda: Gammaridea) from Lake Baikal, Siberia, with redescription of E. cyanoides (Sowinsky) and remarks on taxonomy of the genus Eulimnogammarus.

    PubMed

    Bedulina, Daria S; Takhteev, Vadim V; Pogrebnyak, Svyatoslav G; Govorukhina, Ekaterina B; Madyarova, Ekaterina V; Lubyaga, Yulia A; Vereshchagina, Kseniya P; Timofeyev, Maxim A; Luckenbach, Till

    2014-07-22

    A new amphipod species of the endemic fauna of Lake Baikal (East Siberia, Russia), Eulimnogammarus messerschmidtii sp. n., from the littoral zone of the northern part of the lake is described. The species is characterized by the presence of a group of spines with dense setae on the last 4 body segments. The basal peduncular segment of antenna 1 bears bunches of dense setae without spines, uropods 3 are covered by dense simple setae without plumose setae and the outer ramus has a second small article. The body length of sampled specimens ranges from 7.5 to 18 mm. Population analysis at one of the sampling points revealed a spring-summer reproduction period for this species. This species was previously erroneously identified as E. cyanoides. E. cyanoides is here redescribed in details based on the lectotype. The differences between E. messerschmidtii sp. n., E. cyanoides and other closely related Eulimnogammarus species are described. The taxonomy of the genus Eulimnogammarus is discussed.

  13. 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.

  14. 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

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

    PubMed

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

    2013-01-01

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

  16. 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.

  17. Das Schwimmen der Talitridae (Crustacea, Amphipoda): Funktionsmorphologie, Phänomenologie und Energetik

    NASA Astrophysics Data System (ADS)

    Vogel, Friedhelm

    1985-09-01

    The Talitridae, well-known for their jumping behaviour, swim with help of the tail-flip. This movement of the abdomen is also known from other amphipods like the Gammaridae which are normally not able to move by jerks outside the water. The suspected homology between the tail-flip when swimming and the jerky movement of the abdomen when jumping gave rise to this investigation, mainly based on high frequency film recordings, on the swimming of Hyale nilssonii, Orchestia cavimana, and Talitrus saltator (family Talitridae) as well as three related species of the families Gammaridae and Corophiidae. Comparative morphometrical and SEM-studies on the habitus of the species and the build of the involved limbs reveal the rather uniform construction of the Gammaridea; functional adaptation to the environment and to the way of living become apparent in minor alterations. The joints of the pleopods and uropods show a clear structural adaptation to the mechanical strain during swimming. The pleopods are moved metachronally in all examined species; angular velocity and rate of beating indicate the efficiency of the swimming movement. In the Talitridae, the metachronal beat of the pleopods is nearly always coupled with the tail-flip while in the Gammaridae and Corophiidae the tail-flip, in addition to the beat of the pleopods, is mostly used for a start from the subsoil or for a change in swimming direction. H. nilssonii, Gammarus locusta, and Corophium volutator, all inhabitants of the tidal zone in the North Sea shallows, turned out to be the “best” swimmers while the (semi-) terrestrially living species, O. cavimana and T. saltator, proved to be rather “poor” swimmers. This clearly indicates the ecological significance of swimming for the different species. Furthermore, the tailflip is found to be of rather subordinate importance. It contributes to a higher velocity if used moderately but is rather obstructive if a large angle is covered while extending and flexing

  18. 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.

  19. 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

    2016-01-20

    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.

  20. Development of Ascarophis sp. (Nematoda: Cystidicolidae) to maturity in Gammarus deubeni (Amphipoda).

    PubMed

    Appy, Ralph G; Butterworth, Eric W

    2011-12-01

    Experimentally transmitted Ascarophis sp. (Spirurida) developed to adult worms in the invertebrate host, Gammarus deubeni (Amphipoda), collected in the intertidal zone in Passamaquoddy Bay, New Brunswick, Canada. The morphological development and growth of larval stages is very similar to other cystidicolids, which are found as adults in fish. Unlike virtually all other Spirurida, which require a vertebrate definitive host, infective larvae of Ascarophis sp. migrate from the invertebrate host musculature into the hemocoel where they molt twice to become adults. Gravid females appear at 80 days and 69 days post-infection at 10-12 C and 18-20 C, respectively. While there is little evident host reaction to the parasite within the muscle tissue, within the hemocoel there is hemocytic reaction to shed nematode cuticles, released eggs, and sometimes the worm itself, including some melanization. The worms are morphologically similar to Ascarophis sp. from G. oceanicus in the Baltic and White seas and among Ascarophis species from fish is most similar to A. arctica. It is suggested that Ascarophis sp. no longer requires a vertebrate host and is transmitted between amphipods either through death and disintegration of infected amphipods and dispersal of the nematode eggs, or more likely through cannibalism or necrophagy.

  1. The complete mitochondrial genome of Caprella scaura (Crustacea, Amphipoda, Caprellidea), with emphasis on the unique gene order pattern and duplicated control region.

    PubMed

    Ito, Atsushi; Aoki, Masakazu N; Yokobori, Shin-Ichi; Wada, Hiroshi

    2010-10-01

    The nucleotide and amino acid sequences and the gene order of the mitochondrial genome are highly informative for studying phylogeny, population genetics, and phylogeography. This study determined the complete mitochondrial genome of the caprellid species Caprella scaura. The mitochondrial genome of C. scaura has a total length of 15,079 bp, with an AT content of 66.43%. The mitochondrial genome contains typical gene components, including 13 protein-coding genes, 2 rRNA genes, and 22 tRNA genes. In comparison with the mitochondrial genome of a gammarid, some distinct characteristics were found. For example, the order of the two conserved gene blocks is inverted between Gammaridea and C. scaura. In addition, two copies of almost identical control regions were found in the mitochondrial genome of C. scaura. These unique characteristics will be useful for determining the evolutionary history of the Caprellidea.

  2. Mitochondrial DNA reveals multiple Northern Hemisphere introductions of Caprella mutica (Crustacea, Amphipoda).

    PubMed

    Ashton, Gail V; Stevens, Mark I; Hart, Mark C; Green, David H; Burrows, Michael T; Cook, Elizabeth J; Willis, Kate J

    2008-03-01

    Caprella mutica (Crustacea, Amphipoda) has been widely introduced to non-native regions in the last 40 years. Its native habitat is sub-boreal northeast Asia, but in the Northern Hemisphere, it is now found on both coasts of North America, and North Atlantic coastlines of Europe. Direct sequencing of mitochondrial DNA (cytochrome c oxidase subunit I gene) was used to compare genetic variation in native and non-native populations of C. mutica. These data were used to investigate the invasion history of C. mutica and to test potential source populations in Japan. High diversity (31 haplotypes from 49 individuals), but no phylogeographical structure, was identified in four populations in the putative native range. In contrast, non-native populations showed reduced genetic diversity (7 haplotypes from 249 individuals) and informative phylogeographical structure. Grouping of C. mutica populations into native, east Pacific, and Atlantic groups explained the most among-region variation (59%). This indicates independent introduction pathways for C. mutica to the Pacific and Atlantic coasts of North America. Two dominant haplotypes were identified in eastern and western Atlantic coastal populations, indicating several dispersal routes within the Atlantic. The analysis indicated that several introductions from multiple sources were likely to be responsible for the observed global distribution of C. mutica, but the pathways were least well defined among the Atlantic populations. The four sampled populations of C. mutica in Japan could not be identified as the direct source of the non-native populations examined in this study. The high diversity within the Japan populations indicates that the native range needs to be assessed at a far greater scale, both within and among populations, to accurately assess the source of the global spread of C. mutica.

  3. Two new species and one newly recorded species of the genus Kamaka (Crustacea: Amphipoda) from the Hainan Province, South China Sea.

    PubMed

    Ren, Xian-qiu; Sha, Zhong-li

    2013-01-01

    A total of 5 species of the genus Kamaka (Crustacea: Amphipoda) are identified from Hainan Province, South China Sea. In those, one species, Kamaka excavata Ariyama, 2007, is recorded for the first time in Chinese waters. Two new species, Kamaka corophina sp. n. and Kamaka foliacea sp. n., are described. A key to the Chinese species is provided. They were collected from littoral zone, mud flat in seaweed of mangrove side, brackish water and seawater, sifted out with sieve.

  4. A new troglobiotic species of Hyalella (Crustacea, Amphipoda, Hyalellidae) with a taxonomic key for the Brazilian species.

    PubMed

    Rodrigues, Stella Gomes; De Pádua Bueno, Alessandra Angélica; Ferreira, Rodrigo Lopes

    2014-06-13

    The freshwater crustaceans from the order Amphipoda occur mainly in cold and temperate climates. However, in the tropics, these animals can be more abundant in subterranean environments, where the temperatures are milder than in surface. Despite being accepted that the number of species of freshwater amphipods in South America is lower when compared to other regions, recent descriptions have shown that its diversity is certainly underestimated. In this study, a new species of the genus Hyalella is described for Brazil, the fourth troglobiotic species of Hyalella for the country and the sixth in the world. The new species was found on the epikarst of a cave in São Paulo state, Southeastern Brazil. Besides, the new species shows typical characteristics from organisms adapted to the subterranean environments, a pattern also observed in the other troglobiotic species of the genus.

  5. Three new species of the Eriopisa group (Crustacea: Amphipoda: Eriopisidae) from Japan, with the description of a new genus.

    PubMed

    Ariyama, Hiroyuki

    2015-04-23

    Three new species of the Eriopisa group (Crustacea: Amphipoda: Eriopisidae) are described from coastal areas in Japan. Paraflagitopisa gen. nov. is established with P. excavata sp. nov. as its type species. This new genus is characterized by (1) entire lateral cephalic lobe, (2) unfused flagellum of antenna 2, (3) 3-articulated mandibular palp, (4) carpus of gnathopod 1 longer than propodus, (5) transverse palm of gnathopod 1, and (6) slender outer ramus of uropod 3 with long second article, and can be distinguished from the closely related genus, Flagitopisa, by the article 2 of mandibular palp longer than article 3, the undilated bases of pereopods 3-4, and the slender inner ramus of uropod 3. Psammogammarus lobatus sp. nov. is characterized by (1) male gnathopod 2 with excavated palm, (2) posterodistally projected bases of pereopods 5-7, (3) quadrate posteroventral corner of pleonal epimeron 3, (4) short inner ramus of uropod 3, and (5) article 2 of uropod 3 outer ramus longer than article 1. Victoriopisa wadai sp. nov. has the following characters: (1) eyes absent, (2) peduncle of antenna 1 not heavily setose, (3) accessory flagellum with 1-2 articles, (4) flagellum of antenna 2 composed of 2 long and 3 short articles, (5) gnathopod 2 in both sexes with excavated palm, (6) merus of pereopod 7 moderately expanded, and (7) ventral margin of pleonite 2 slightly setose. Key to species of the Eriopisa group in Japan is provided.

  6. The mitogenome of Gammarus duebeni (Crustacea Amphipoda): A new gene order and non-neutral sequence evolution of tandem repeats in the control region.

    PubMed

    Krebes, Lukas; Bastrop, Ralf

    2012-06-01

    We determined the complete mitogenome sequence of Gammarus duebeni (Peracarida, Amphipoda). The mitogenome is circular and has a length of 15,651bp. The content corresponds to typical mitogenomes of metazoans. The gene order and transcriptional polarity of the protein-coding genes is identical to the pancrustacean ground pattern. Six tRNA genes are rearranged, making the gene order unique. Thus it will bring forward the understanding of mitogenome evolution within the Peracarida, for which much more derived gene orders are known. We postulate that the gene string trnA-trnS1 (AGN)-trnN-trnE-trnR constitutes an apomorphic character for the Amphipoda. In contrast to the relatively large genome size, we found two extremely truncated rRNA genes. The rrnL gene is the shortest (986bp) reported up until now for crustaceans. A six-time imperfect tandem repeat was observed within the control region. The inferred deterministic pattern of variation between the repeat units makes it likely, that functional constraints play an important role in the evolutionary dynamics and extant appearance of the repeat array. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Ecological remarks and re-description of the hermit crab-associated pleustid amphipod Pleusymtes japonica (Gurjanova, 1938) (Crustacea: Amphipoda: Pleustidae: Pleusymtinae) from the Russian coasts of the Sea of Japan.

    PubMed

    Ivan, Marin; Sinelnikov, Sergey; Agniya, Sokolova

    2013-01-01

    Numerous specimens of poorly known pleustid amphipod Pleusymtes japonica (Gurjanova, 1938) (Crustacea: Amphipoda: Pleustidae: Pleusymtinae) were found in association with large hermit crab Pagurus ochotensis Brandt, 1851 (Crustacea: Decapoda: Paguridae) near Furugelma Island in the Sea of Japan. This is the first report of the species in association with hermit crabs. Amphipods were found living close to the shell aperture and hermit crab feeding appendages. Color photographs, remarks on ecology and re-description of the species are given.

  8. A revision of the genus Paracallisoma Chevreux, 1903 (Crustacea: Amphipoda: Scopelocheiridae: Paracallisominae) with a redescription of the type species of the genus Paracallisoma and the description of two new genera and two new species from the Atlantic Ocean.

    PubMed

    Horton, Tammy; Thurston, Michael H

    2015-08-05

    The genus Paracallisoma (Crustacea: Amphipoda) is revised and the type species, Paracallisoma alberti is redescribed based on holotype material supplemented with new material from the region of the type locality. This revision results in the establishment of two new genera, Pseudocallisoma gen. nov. and Haptocallisoma gen. nov., and the description of a new species of Haptocallisoma and a new species of Paracallisoma from the North Atlantic Ocean. An account of all known species within the three genera is given and updated keys to the genera and species are provided.

  9. Five species of the family Cyproideidae (Crustacea: Amphipoda) from Japan, with the description of a new genus and two new species.

    PubMed

    Ariyama, Hiroyuki

    2016-03-31

    Five species of the family Cyproideidae (Crustacea: Amphipoda) are described from shallow sea in Japan. Cyproidea liodactyla Hirayama, 1978 was collected from Kanagawa and Shizuoka Prefectures and Ariake Sea. Morphological character of the antenna 1 in these specimens is different from the original description. Examining the paratypes of C. liodactyla, the shape of the antenna 1 in the holotype is revealed to be abnormal. Cyproidea okinawensis sp. nov. was collected from Okinawa Island. Its morphological characters resemble C. liodactyla and C. robusta Ren, 2006; however, this new species is different from the former in the smaller eyes, the narrower coxa 5 and the coloration, and from the latter in the ovoid telson. Metacyproidea gen. nov. is established with M. makie sp. nov. from Hachijo Island in Tokyo Prefecture as its type species. This new genus resembles Cyproidea, especially in the peduncular article 2 of antenna 1 with a distinct distal tooth and the posterodorsal end of urosomites with a strong projection. However, Metacyproidea can be distinguished from Cyproidea by the coalesced urosomites 2-3 and the antenna 1 with a 10-16-articulated flagellum. Moolapheonoides acutifalcatus Kobayashi & Ishimaru, 2005 and Terepeltopes dolichorhunia Hirayama, 1983 were also collected from Wakayama and Fukui Prefectures and Kanagawa, Shizuoka and Yamaguchi Prefectures, respectively. A key to species of the family Cyproideidae in Japan is provided.

  10. Variations in sensitivity of two populations of Corophium orientale (Crustacea: Amphipoda) towards cadmium and sodium laurylsulphate. Comparison of two populations of Corophium orientale.

    PubMed

    Lera, S; Macchia, S; Dentone, L; Pellegrini, D

    2008-01-01

    The aim of this work was to monitor the sensitivity of two populations of Corophium orientale (Crustacea: Amphipoda) living at the outfall of two rivers (Magra and Serchio), comparing their responses towards two different toxicant solutions. Sensitivity was monthly checked performing the 96h-LC50 static water only test with Cd(NO3)2 and SDS. If no significant differences were found between the two populations, they could have been employed without distinction to perform sediment toxicity bioassays. As regard to Cd, an increasing in LC50 values from summer to winter was evident in each population (Serchio River: August 2003 = 1,36 mg/l, February 2004 = 7,23 mg/l; Magra River: August = 1,21 mg/l, April = 5,01 mg/l). This pattern was correlated to the droop of temperatures in winter period. The responses of the two populations towards the cadmium were compared using the ANOVA. The analysis showed any significant differences between the populations (p = 0.12). The pattern of sensitivity towards SDS for the population living on Magra River was similar to the same pattern found for Cd; as regard to the population living on Serchio River, data were not enough to describe the annual pattern. Anyway, statistical analysis was performed and no significant differences were found between the two populations (p = 0.34).

  11. 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).

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Toxicity of stormwater treatment pond sediments to Hyallela azteca (Amphipoda)

    USGS Publications Warehouse

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

    1997-01-01

    Stormwater wetlands are created to contain runoff from human developments and are designed to retain contaminants such as heavy metals, petroleum hydrocarbons, silt, pesticides, and nutrients before the runoff enter natural waterways. Because of this design, stormwater wetlands have a potential of becoming toxic sinks to organisms utilizing the wetlands for habitat. We conducted a 10-day sediment bioassay on Hyallela azteca as part of a larger study on the possible hazards of stormwater wetlands to aquatic invertebrates. Water and sediments from 10 wetlands separated into reference, residential, commercial, and highway land uses were used. No differences in survival were observed among land use categories, possibly because the ratio of acid volatile sulfides/simultaneously extractable metals (AVS/SEM) was > 1.0 for all of the ponds tested; values > 1 in this ratio are indications that toxic metals may not be bioavailable. Survival and growth rates correlated positively with AVS.

  17. Two new species of Floresorchestia (Crustacea, Amphipoda, Talitridae) in Thailand.

    PubMed

    Wongkamhaeng, Koraon; Dumrongrojwattana, Pongrat; Pattaratumrong, Manasawan Saengsakda

    2016-01-01

    The beach-hopper and land-hopper genus Floresorchestia Bousfield, 1984 is most widespread in terrestrial and marine littoral habitats and has been recorded from the South African coasts through to tropical Indo-Pacific and Caribbean Sea. In Thailand, there is only Floresorchestia samroiyodensis Azman, Wongkamhaeng & Dumrongrojwattana, 2014 reported from the swamp of Prachuab Kiri Khan, southern Thailand. In this work, two new species of Floresorchestia from Phutsa Reservoir in Nakhon Ratchasima and the man-made swamp in Burapha University are described. The new species are characterised by the mandible left lacinia mobilis 4-dentate; the posterior margin of merus, carpus and propodus covered in palmate setae; the uropod 3 peduncle with two robust setae and the telson longer than broad. The characters of the specimens are described and illustrated in this paper. All specimens are deposited in the Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand.

  18. Amphipoda (Crustacea) from Palau, Micronesia: Families Maeridae and Melitidae.

    PubMed

    Myers, A A

    2016-09-26

    Seven species of senticaudate amphipods belonging to the families Maeridae and Melitidae are recorded from Palau, Federated States of Micronesia, and are figured. Three species are new to science and are fully described and figured.

  19. Two new species of Floresorchestia (Crustacea, Amphipoda, Talitridae) in Thailand

    PubMed Central

    Wongkamhaeng, Koraon; Dumrongrojwattana, Pongrat; Pattaratumrong, Manasawan Saengsakda

    2016-01-01

    Abstract The beach-hopper and land-hopper genus Floresorchestia Bousfield, 1984 is most widespread in terrestrial and marine littoral habitats and has been recorded from the South African coasts through to tropical Indo-Pacific and Caribbean Sea. In Thailand, there is only Floresorchestia samroiyodensis Azman, Wongkamhaeng & Dumrongrojwattana, 2014 reported from the swamp of Prachuab Kiri Khan, southern Thailand. In this work, two new species of Floresorchestia from Phutsa Reservoir in Nakhon Ratchasima and the man-made swamp in Burapha University are described. The new species are characterised by the mandible left lacinia mobilis 4-dentate; the posterior margin of merus, carpus and propodus covered in palmate setae; the uropod 3 peduncle with two robust setae and the telson longer than broad. The characters of the specimens are described and illustrated in this paper. All specimens are deposited in the Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand. PMID:27917056

  20. Population studies on the Amphipoda of Mazoma Lagoon (Greece)

    NASA Astrophysics Data System (ADS)

    Karakiri, Maria; Nicolaidou, Artemis

    1987-12-01

    The life cycles of four amphipod species— Gammarus insensibilis, Dexamine spinosa, Microdeutopus gryllotalpa and Corophium insidiosum—were studied in the brackish-water lagoon Mazoma of the Amvrakikos Gulf, Ionian Sea. G. insensibilis has an annual life cycle with limited recruitment over the year and maximum reproductive activity in the winter months. D. spinosa exhibits continuous recruitment in the lagoon with a maximum in summer. Both species produce a single brood per female per yer. Continuous recruitment was observed during the summer months for M. gryllotalpa and C. insidiosum, and multiple breeding per female per year. Sex ratios varied considerably over the year, with a persisting preponderance of the females.

  1. Infestation patterns of microphallid trematodes in Corophium volutator (Amphipoda)

    NASA Astrophysics Data System (ADS)

    Meißner, Karin

    2001-05-01

    Infestation patterns of digenetic trematodes in Corophium volutator (Pallas, 1766) were studied in a shallow-water area of the southern Baltic Sea. The amphipod C. volutator is the most common second intermediate host of microphallid trematodes, in particular Maritrema subdolum, in this area. Seasonal and interannual alterations in infestation among the amphipod population are described. The general trend of infestation followed a relatively invariable seasonal pattern. Lowest prevalences were generally observed in spring and early summer, when juvenile amphipods predominated. Increasing prevalences and relative infestation intensities were recorded over the summer, with the highest values in late summer and autumn. These observations are mainly explained by the population dynamics of C. volutator and the infection dynamics of the first intermediate hosts, mudsnails of the genus Hydrobia. Exceptionally high infestation rates in summer 1997 may have been triggered by the earlier appearance of high cercaria densities in the field compared to 1996. The coincidence of the infection dynamics of the first intermediate host with the population dynamics of C. volutator was apparently important. Parasite infestation, in turn, obviously induced mortality of the crustacean host, but conclusive evidence could not be provided based on the analysis of the parasite dispersion patterns in C. volutator.

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

    PubMed

    Lowry, J K; Springthorpe, R T

    2015-03-17

    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.

  3. The talitrid amphipods of Tonga (Crustacea, Amphipoda, Talitridae).

    PubMed

    Lowry, J K; Bopiah, Arundathi

    2013-01-01

    One new genus and four species of talitrid amphipods are described from Tonga: Platorchestia ano sp. nov.; Talorchestia spinipalma (Dana, 1852); Tongorchestia pangaimotu gen. nov., sp. nov.; T. towneri sp. nov.

  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. 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.

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

    PubMed

    Hughes, Lauren E

    2015-12-22

    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.

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

    PubMed

    Hughes, Lauren E

    2016-02-04

    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.

  8. First record of Sinocorophium homoceratum (Yu, 1938) (Crustacea, Amphipoda, Corophiidae) from Korea

    NASA Astrophysics Data System (ADS)

    Ko, Ara; Park, Kwan Ha; Jo, Soo-Gun

    2017-06-01

    Sinocorophium homoceratum belonging to the family Corophiidae is reported here in the first specimens found in Gomso Bay, Korea. S. homoceratum can be easily distinguished from its relatives by the forms of the uropods, antenna 1, and antenna 2. The present specimens agree well with the original description of this species, with the exception of some minor characteristics in the uropod 3. The present study gives a detailed description with illustrative figures, and extends the distribution range of this species from China to Korea.

  9. 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.

  10. 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).

  11. 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.

  12. Persianorchestia, a new talitrid genus (Crustacea: Amphipoda: Talitridae) from Gulf of Oman, Iran.

    PubMed

    Momtazi, Farzaneh; Lowry, Jim; Hekmatara, Maryam

    2017-03-02

    A new genus and species, Persianorchestia nirvana gen. et sp. nov., is described from the south coast of Iran along the Gulf of Oman. The new genus is characterized by large eyes, gnathopod 1 posterior margin of carpus and propodus each with lobe covered in palmate setae, smooth posterior margin on dactylus of male gnathopod 2, a slender dactylus on pereopod 5, uropod 1 outer ramus without marginal robust setae and with apical spear-shaped setae on the rami of uropods 1 and 2. Persianorchestia is most similar to Pseudorchestoidea Bousfield, 1982.

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

  14. A review of the world Cyphocarididae with description of three new species (Crustacea, Amphipoda, Lysianassoidea).

    PubMed

    Hughes, Lauren E; Lowry, James K

    2015-12-15

    The world Cyphocarididae are reviewed with new distribution records provided for eight taxa including three new species of Cyphocaris, C. ananke, C. nesoi and C. tartaros. Based on collections from Greenland a neotype is established for the type species Cyphocaris anonyx Boeck, 1871. An updated key to the 17 known world species of cyphocarids is provided.

  15. Endevouridae, a review with description of four new species (Crustacea, Amphipoda, Lysianassoidea).

    PubMed

    Lowry, James K; Hughes, Lauren E

    2015-09-14

    The family Endevouridae is reviewed and four new species from the two genera, Endevoura and Ensayara, are described from Australian and Japanese waters. All species are diagnosed and the type species of Endevoura (End. mirabilis Chilton, 1921) and Ensayara (Ens. ramonella J.L. Barnard, 1964), respectively, are redescribed and illustrated. A key to the 19 known world species of Endevouridae is provided.

  16. Talorchestia qeshm sp. nov., a new talitrid amphipod from the Persian Gulf (Amphipoda, Talitridae).

    PubMed

    Lowry, Im; Momtazi, Farzaneh

    2015-07-13

    A new talitrid amphipod species, Talorchestia qeshm sp. nov., is described from Qeshm Island in the south-eastern Persian Gulf. This is the westernmost confirmed record for Talorchestia and places the genus firmly in the western Indian Ocean.

  17. Siphonoecetini Just, 1983 (Crustacea, Amphipoda, Ischyroceridae) 11: Cephaloecetes schioettei sp. nov. from The Philippines.

    PubMed

    Just, Jean

    2017-05-29

    The new species described below, Cephaloecetes schioettei, is the second siphonoecetine to be recorded from the archipelago region of Indonesia, The Philippines and Papua New Guinea. The previous reports were of Borneoecetes wongi Barnard & Thomas, 1984 from Borneo and from Papua New Guinea by Myers (1995).

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

    PubMed

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

    2016-09-06

    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.

  19. 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

  20. 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.

  1. 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  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. A new species of the genus Nicippe from Japan (Crustacea, Amphipoda, Pardaliscidae)

    PubMed Central

    Matsukami, Sachi; Nakano, Takafumi; Tomikawa, Ko

    2017-01-01

    Abstract A new species of the pardaliscid amphipod, Nicippe recticaudata, from off Cape Toi, Japan, is named and described. This is the first record of Nicippe Bruzelius, 1859 from the western Pacific coast of the Japanese archipelago. Additionally, nucleotide sequences of nuclear 28S ribosomal RNA and histone H3 as well as mitochondrial cytochrome c oxidase subunit I (COI) and 16S ribosomal RNA from the holotype and paratypes were determined. The morphological characteristics and the COI distance values enforced the distinctiveness of N. recticaudata sp. n. among the known Nicippe species. Nicippe recticaudata sp. n. closely resembles N. tumida Bruzelius, 1859 in having a two-dentate posterior margin of usoromite 1. However, the former is distinguished from the latter by the posterior margin of merus of pereopod 4 with 5–6 setae, anterior margin of merus of pereopod 5 with 9–10 setae, and telson with straight inner margin, tapering proximally. A key to the species of Nicippe is provided. PMID:28769641

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

    PubMed

    González, Exequiel R; Watling, Les

    2002-06-01

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

  5. Diversity and distribution of freshwater amphipod species in Switzerland (Crustacea: Amphipoda).

    PubMed

    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.

  6. 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.

  7. 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.

  8. Amazing new Amphipoda (Crustacea, Epimeriidae) from New Zealand's deep-sea.

    PubMed

    Lörz, Anne-Nina; Coleman, Charles Oliver

    2014-07-21

    Epimeriidae is an amphipod family with a worldwide distribution. Two new species have been discovered off New Zealand; Epimeria sophie sp. nov. and Epimeria emma sp. nov. Two new species have been discovered off New Zealand; Epimeria sophie sp. nov. and Epimeria emma sp. nov., which are described here in detail. This increases the number of Epimeria species known from New Zealand's deep-sea to seven. The morphological differences of the juveniles with the adult of Epimeria sophie sp. nov. are discussed. Extensive scanning electron microscope images reveal structurally very complex surface arrangements on Epimeria emma sp. nov. A key to the 14 species of Pacific Epimeria is provided.

  9. Dietary analysis of the marine Amphipoda (Crustacea: Peracarida) from the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Guerra-García, J. M.; Tierno de Figueroa, J. M.; Navarro-Barranco, C.; Ros, M.; Sánchez-Moyano, J. E.; Moreira, J.

    2014-01-01

    The gut contents of 2982 specimens of 33 amphipod families, 71 genera and 149 species were examined, representing a high percentage of amphipod diversity in the Iberian Peninsula. Material was collected mainly from sediments, algae and hydroids along the whole coast of the Iberian Peninsula from 1989 to 2011. Although detritus was the dominant food item in the majority of amphipods, gammarideans also included carnivorous (mainly feeding on crustaceans) and herbivorous species (feeding on macroalgal tissues). Our study revealed that general assignment of a type of diet for a whole family is not always adequate. Some families showed a consistent pattern in most of the studied species (Corophiidae, Pontoporeiidae = detritivorous; Oedicerotidae, Phoxocephalidae, Stenothoidae = carnivorous; Ampithoidae = primarily herbivorous on macroalgae), but others included species with totally different feeding strategies. In general terms, detritivorous families were characterized by a stronger mandibular molar, while in carnivorous taxa this feature was less developed or reduced. The percentage of macroalgae in the digestive contents was associated in most cases with a reduction or loss of the mandibular palp. It seems that high trophic diversity in amphipods is a generalized trait along different ecosystems in all latitudes, and could be related to the ecological success of this group in marine benthic communities.

  10. Epimeria abyssalis sp. n. from the Kuril-Kamchatka Trench (Crustacea, Amphipoda, Epimeriidae).

    PubMed

    Shimomura, Michitaka; Tomikawa, Ko

    2016-01-01

    A new deep-sea epimeriid, Epimeria abyssalis is described from the Kuril-Kamchatka Trench, in the northwestern Pacific. This species differs from its congeners in having a short rostrum and a telson with deep and narrow Y-shaped excavation. Epimeria abyssalis is the deepest recorded Epimeria species. A key to the north Pacific species of Epimeria is provided.

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

    USGS Publications Warehouse

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

    2016-01-01

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

  12. 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.

  13. New species and new record of hadzioids (Amphipoda: Senticaudata, Hadzioidea) from the Persian Gulf, Iran.

    PubMed

    Momtazi, Farzaneh; Sari, Alireza; Maghsoudlou, Abdolvahab

    2014-11-07

    New record and new species of the families Melitidae Bousfield, 1973 and Maeridae Krapp-Schickel, 2008 are described from the Iranian shorelines of the Persian Gulf. Melita persia sp. nov. is differentiated from other members of M. zeylanica Stebbing, 1904 group by: the presence of two setae on inner ramus of third uropod, the setal arrangement on the telson, and a recurved proximal lobe of sixth coxa in females. Also, Elasmopus menurte Barnard, 1974 previously described from Western Australia and Mauritius is recorded, for the first time, from Persian Gulf in the north-western Indian Ocean.

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

    PubMed

    Myers, A A

    2014-06-05

    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.

  15. New species of Floresorchestia from Micronesia living in unusual habitats (Crustacea, Amphipoda, Talitridae).

    PubMed

    Lowry, J K; Myers, A A

    2013-11-22

    The first freshwater talitrid, Floresorchestia pohnpei sp. nov., is described from the island of Pohnpei, Micronesia. Floresorchestia palau sp. nov. is described from supralittoral and shallow-water marine habitats in Palau, Micronesia.

  16. 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.

  17. Responses of Niphargus montellianus and Gammarus balcanicus (Crustacea, Amphipoda) from karst waters to heavy metal exposure

    NASA Astrophysics Data System (ADS)

    Coppellotti Krupa, O.; Guidolin, L.

    2003-05-01

    The response to some heavy metals (Cd, Cu, and Zn) was examined in two amphipods, Niphargus montellianus and Gammarus balcanicus, living in karst waters and endowed with different ecological characteristics. Exposure experiments were made, in the controlled conditions of a biospeleology laboratory, to increasing concentrations of metals in the range 0.1 10 μg ml^{-1} for up to 10 days. Hypogean and epigean amphipods differed in their responses, G. balcanicus being more sensitive to the toxic effects of heavy metals than the hypogean N montellianus. The degree of tolerance was Cu

  18. Next-generation sequencing, phylogenetic signal and comparative mitogenomic analyses in Metacrangonyctidae (Amphipoda: Crustacea).

    PubMed

    Pons, Joan; Bauzà-Ribot, Maria M; Jaume, Damià; Juan, Carlos

    2014-07-06

    Comparative mitochondrial genomic analyses are rare among crustaceans below the family or genus level. The obliged subterranean crustacean amphipods of the family Metacrangonyctidae, found from the Hispaniola (Antilles) to the Middle East, including the Canary Islands and the peri-Mediterranean region, have an evolutionary history and peculiar biogeography that can respond to Tethyan vicariance. Indeed, recent phylogenetic analysis using all protein-coding mitochondrial sequences and one nuclear ribosomal gene have lent support to this hypothesis (Bauzà-Ribot et al. 2012). We present the analyses of mitochondrial genome sequences of 21 metacrangonyctids in the genera Metacrangonyx and Longipodacrangonyx, covering the entire geographical range of the family. Most mitogenomes were attained by next-generation sequencing techniques using long-PCR fragments sequenced by Roche FLX/454 or GS Junior pyro-sequencing, obtaining a coverage depth per nucleotide of up to 281×. All mitogenomes were AT-rich and included the usual 37 genes of the metazoan mitochondrial genome, but showed a unique derived gene order not matched in any other amphipod mitogenome. We compare and discuss features such as strand bias, phylogenetic informativeness, non-synonymous/synonymous substitution rates and other mitogenomic characteristics, including ribosomal and transfer RNAs annotation and structure. Next-generation sequencing of pooled long-PCR amplicons can help to rapidly generate mitogenomic information of a high number of related species to be used in phylogenetic and genomic evolutionary studies. The mitogenomes of the Metacrangonyctidae have the usual characteristics of the metazoan mitogenomes (circular molecules of 15,000-16,000 bp, coding for 13 protein genes, 22 tRNAs and two ribosomal genes) and show a conserved gene order with several rearrangements with respect to the presumed Pancrustacean ground pattern. Strand nucleotide bias appears to be reversed with respect to the condition displayed in the majority of crustacean mitogenomes since metacrangonyctids show a GC-skew at the (+) and (-) strands; this feature has been reported also in the few mitogenomes of Isopoda (Peracarida) known thus far. The features of the rRNAs, tRNAs and sequence motifs of the control region of the Metacrangonyctidae are similar to those of the few crustaceans studied at present.

  19. 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

  20. Debroyerella gen. nov. and Ulladulla gen. nov., two new lysianassoid genera (Crustacea, Amphipoda, Lysianassoidea).

    PubMed

    Lowry, J K; Kilgallen, N M

    2015-02-19

    Two new genera and a new species of lysianassoid amphipods are described. Debroyerella gen. nov. is described for three Antarctic species previously assigned to the genus Cheirimedon. Ulladulla gen. nov. is described to accommodate the new species U. selje, from Australian waters. Diagnostic descriptions are given for the genera and all species are described in full.

  1. First molecular evidence for underestimated biodiversity of Rhachotropis (Crustacea, Amphipoda), with description of a new species.

    PubMed

    Lörz, Anne-Nina; Linse, Katrin; Smith, Peter J; Steinke, Dirk

    2012-01-01

    The crustacean genus Rhachotropis has a worldwide distribution and amongst the largest bathymetric range known from any amphipod genus. DNA barcoding of new material from around New Zealand and the Ross Sea indicated depth-related biogeographic patterns. New Zealand Rhachotropis do not form a monophyletic clade. Species from bathyal depths on the Chatham Rise, east of New Zealand, show lower sequence divergence to bathyal species from California and the Arctic than to abyssal New Zealand species. Species sampled in the Kermadec Trench, north of New Zealand below 5000 m, seem to be more closely related to Ross Sea abyssal species than to the New Zealand shelf species. The worldwide geographic and bathymetric distribution for all Rhachotropis species is presented here. Depth may have a greater influence on phylogeny than geographic distance.Molecular and morphological investigations of Rhachotropis specimens from the Chatham Rise, New Zealand revealed a species new to science which is described in detail, including scanning electron microscopy. This increases the number of described species of Rhachotropis to 60 worldwide.

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

    PubMed

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

    2006-03-01

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

  3. Overview and quantification of the factors affecting the upstream and downstream movements of Gammarus pulex (Amphipoda).

    PubMed

    Dedecker, Andy P; Goethals, Peter L; De Pauw, Niels

    2003-01-01

    Human activities have severely deteriorated the Flemish river systems, and many functions such as drinking water supply, fishing, ... are threatened. Because their restoration entails drastic social (e.g. change in habits with regard to water use and discharge, urban planning) and economical (e.g. investment in nature restoration, wastewater treatment system installation) consequences, the decisions should be taken with enough forethought. Ecosystem models can act as interesting tools to support decision-making in river restoration management. In particular models that can predict the habitat requirements of organisms are of considerable importance to ensure that the planned actions have the desired effects on the aquatic ecosystems. In preliminary studies, Artificial Neural Network (ANN) models were tested and optimized to obtain the best model configuration for the prediction of the habitat suitability for Gammarus pulex based on the abiotic characteristics of their aquatic environment in the Zwalm river basin (Flanders, Belgium). Although, these ANN models are in general quite robust with a rather high predictive reliability, the model performance has to be increased with regard to simulations for river restoration management. In particular, spatial-temporal expert-rules have to be included. Migration kinetics (downstream drift and upstream migration) of the organism and migration barriers along the river (weirs, impounded river sections, ...) can deliver important additional information on the effectiveness of the restoration plans, and also on the timing of the expected effects. This paper presents an overview and quantification of the factors affecting the upstream and downstream movements of Gammarus pulex. During further research, ANN models will be used to predict the habitat suitability for Gammarus pulex after several restoration options. The migration models, implemented in a Geographical Information System (GIS), are applied to calculate the migration time to the restored parts of the river. In this way, decision makers have an idea whether and when a selected restoration option has the desired effect.

  4. Commensal Leucothoidae (Crustacea, Amphipoda) of the Ryukyu Archipelago, Japan. Part III: coral rubble-dwellers

    PubMed Central

    White, Kristine N.; Reimer, James Davis

    2012-01-01

    Abstract Commensal leucothoid amphipods have been collected from coral rubble samples throughout the Ryukyu Archipelago, Japan. Seven new species are described in two generawith valuable location data. A new locality is presented for Paranamixis misakiensis Thomas, 1997. An identification key to all described Leucothoidae of the Ryukyu Archipelago is provided. PMID:22448118

  5. Commensal Leucothoidae (Crustacea, Amphipoda) of the Ryukyu Archipelago, Japan. Part I: ascidian-dwellers

    PubMed Central

    White, Kristine N.; Reimer, James Davis

    2012-01-01

    Abstract Commensal leucothoid amphipods have been collected from the branchial chambers of their ascidian hosts throughout the Ryukyu Archipelago, Japan. Seven new species are described in two genera with valuable location data and host records. An identification key to ascidian-dwelling Leucothoidae of the Ryukyu Archipelago is provided. PMID:22303128

  6. 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

  7. Orientation at night: an innate moon compass in sandhoppers (Amphipoda: Talitridae).

    PubMed Central

    Ugolini, Alberto; Fantini, Tiziana; Innocenti, Riccardo

    2003-01-01

    The supralittoral amphipod Talitrus saltator is well known for its capacity for astronomical orientation using the sun and moon as compasses. It has also been demonstrated that the sun compass is innate in this species. In our experiments, we released inexpert (naive) young born in the laboratory into a confined environment under the full moon and in the absence of the horizontal component of the magnetic field. They were allowed to see the natural sky and the moon only at the moment of release. The young individuals were obtained in the laboratory by crossing adult individuals from the same and different populations of sandhoppers. The young from intrapopulation crosses were well oriented towards the directions corresponding to those of their parents, whereas the young from interpopulation crosses were oriented in an intermediate direction. Therefore, our experiments demonstrate in the sandhopper T. saltator that sea-land moon orientation relies on an innate chronometrically compensated mechanism. PMID:12614577

  8. Breeding periodicity and sex ratios in epifaunal marine amphipoda in Lough Hyne, Ireland

    NASA Astrophysics Data System (ADS)

    Costello, Mark J.; Myers, Alan A.

    1989-11-01

    Thirteen species of amphipod were recorded from sponges and associated biota, notably algae and tunicates, in Lough Hyne (Ine), south-west Ireland. The sex ratio rarely approached unity in any species. No male Corophium bonnellii were collected. Mature male Lysianassa ceratina were not collected between late July and early September. Ovigerous females occurred throughout the year in five species. Lysianassa ceratina had the most restricted breeding period (May to September). Breeding activity, based on this criterion of reproduction, was generally greatest between April and July, but this period was extended in some species. A secondary autumn peak in breeding activity was recorded in four species. A comparison between the data from the present study and those from a similar study in Scotland suggests that in the case of two of the species, Corophium bonnellii and Lembos websteri, egg production throughout the year may be related to differing summer maximum temperatures.

  9. Comparison of amphipods Corophium insidiosum and C. orientale (Crustacea: Amphipoda) in sediment toxicity testing.

    PubMed

    Prato, Ermelinda; Bigongiari, Nicola; Barghigiani, Corrado; Biandolino, Francesca

    2010-09-01

    The aim of this study was to compare the sensitivity of two Corophidae: Corophium orientale a standardized species and Corophium insidiosum a species more available in the Ionian sea (Southern Italy), in order to evaluate the suitability and applicability of C. insidiosum to sediment toxicity test. The sensitivity of the 2 species was compared through simultaneous bioassays: the 96-h static water-only toxicity test and a 10-day static sediment toxicity test. Sediment samples were collected in the Livorno harbour (Ligurian Sea). Both amphipods showed high sensitivity to reference toxicant and no significant differences were found between the two Corophiidae (t test; p > 0.05). Numerical Sediment Quality Guidelines (SQGs) have been used to relate the chemical concentrations of sediment samples to biological effects. Both amphipod species indicated the same sediment samples as potentially toxic according to chemical data. The results indicate that Corophium insidiosum would be suitable as an alternative test species to the recommended species C. orientale, in the development of sediment toxicity test.

  10. Rhythms of locomotion and oxygen consumption in the estuarine amphipod Corophium volutator (Crustacea: Amphipoda).

    PubMed

    Harris, G J; Morgan, E

    1984-01-01

    The estuarine amphipod Corophium volutator exhibits an endogenous circatidal rhythm of swimming activity, with maxima occurring just after the expected time of high water, under constant laboratory conditions. Oxygen uptake by Corophium is also subject to modulation across the tidal cycle. The period of highest oxygen uptake occurs during the ebb tide, in phase with the period of maximum swimming activity. A second increase in oxygen uptake during the early flood tide is thought to reflect either in-burrow activity or a previously described rhythm of emergence. This being so, this aspect of the animal's respiratory metabolism may be regulated by an autonomous oscillator independent of that governing the animal's swimming behaviour.

  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.

  12. Epimeria abyssalis sp. n. from the Kuril-Kamchatka Trench (Crustacea, Amphipoda, Epimeriidae)

    PubMed Central

    Shimomura, Michitaka; Tomikawa, Ko

    2016-01-01

    Abstract A new deep-sea epimeriid, Epimeria abyssalis is described from the Kuril-Kamchatka Trench, in the northwestern Pacific. This species differs from its congeners in having a short rostrum and a telson with deep and narrow Y-shaped excavation. Epimeria abyssalis is the deepest recorded Epimeria species. A key to the north Pacific species of Epimeria is provided. PMID:28174500

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

    PubMed

    Lowry, J K; Baldanzi, S

    2016-07-27

    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.

  14. The tryphosine genus Cheirimedon in Australian waters (Crustacea, Amphipoda, Lysianassidae, Tryphosinae).

    PubMed

    Kilgallen, N M; Lowry, J K

    2015-09-11

    The genus Cheirimedon is reviewed and the monotypic genus Tryphosoides placed in its synonymy. We describe fourteen new species of Cheirimedon, all from Australian waters, bringing the total number of species in the genus to 22. Full synonymies and distribution data are provided for all taxa. A key to the world species is provided.

  15. A new species of Paracaprella Mayer, 1890 (Amphipoda: Caprellida: Caprellidae) from southern Brazil.

    PubMed

    Lacerda, Mariana B; Masunari, Setuko

    2014-12-23

    A new species of the genus Paracaprella is described based on the specimens associated with the algae Sargassum cymosum and Laurencia obtusa that were collected from infralittoral depths (0.5 to 3.0 m) at Sepultura Beach, Bombinhas and Paciência Beach, Penha, Santa Catarina State, Brazil. This new species differs from the others of the genus by the unique morphology of the males' gnathopod 2: its propodus has a grasping margin provided with a deep groove. An identification key for Paracaprella species is also presented.

  16. 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.

  17. Melita mirzajanii n. sp. (Crustacea: Amphipoda: Melitidae), a puzzling new member of the Caspian fauna.

    PubMed

    Krapp-Schickel, Traudl; Sket, Boris

    2015-04-21

    Described is Melita mirzajanii n. sp. (Melitidae) from the southwestern corner of the Caspian Sea. It shows no particular similarity to any species known from the Mediterranean Sea. It inhabits, as the only amphipod species, dense growths of Amphibalanus cf. improvisus (Darwin 1854) in a port, at low and highly fluctuating salinities. Its most striking characters are: absence of any pleonal or urosomal dorsal teeth (projections), elongated distal article of the mandibular palp, hind margin of last pereopod bases strongly narrowed distad, and epimera posterodistally rectangular. An identification key for the species group of Melita without dorsal teeth and without article 2 on the exopodite of the third uropod is provided.

  18. Ten new Gammarus species (Crustacea: Amphipoda: Gammaridae) from Yunnan-Guizhou Plateau, China.

    PubMed

    Hou, Zhonge; Li, Junbo; Li, Shuqiang

    2013-01-01

    Ten new species of the genus Gammarus are described from Yunnan-Guizhou Plateau, Southwest China, including Gammarus amabilis sp. nov., G. citatus sp. nov., G. echinatus sp. nov., G. egregius sp. nov., G. eliquatus sp. nov., G. hirtellussp. nov., G. margcomosus sp. nov., G. rivalis sp. nov., G. silendus sp. nov. and G. tranquillus sp. nov. Four of them are stygobite and with no eyes. Detailed illustrations and comparisons with related species are presented. A key to all species from Yunnan-Guizhou Plateau are given.

  19. New species Victoriopisa bruneiensis and Apocorophium acutum (Chevreux, 1908) from Brunei (Crustacea: Peracarida: Amphipoda).

    PubMed

    Hossain, M Belal; Hughes, L E

    2016-06-01

    One new and one invasive species of amphipod are described from the subtidal waters of Brunei. The new species Victoriopisa bruneiensis (Melitidae) and the invasive species Apocorophium acutum (Chevereux, 1908) (Corophiidae) were collected from the Sungai Brunei Estuary. Victoriopisa bruneiensis sp. nov. is one of only four Victoriopisa where the eyes are present. An updated key to twelve world species of Victoriopisa is provided. Apocorophium acutum occurs in high density algal matts on pylons/rocks. This is the sixth species of Apocorophium described for the genus.

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

    PubMed

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

    2014-12-08

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

  1. Two new subterranean species of Hyalella Smith, 1874 (Crustacea: Amphipoda: Hyalellidae) from Brazil.

    PubMed

    Cardoso, Giovanna Monticelli; Araujo, Paula Beatriz; De Pádua Bueno, Alessandra Angélica; Ferreira, Rodrigo Lopes

    2014-06-10

    Two new species of Hyalella from Brazil are described. Hyalella veredae sp. n. shows the following characters: eyes reduced or absent in some specimens; antenna 1 and antenna 2 of similar size, and a curved seta on the inner ramus of male uropod 1. Hyalella formosa sp. n. is characterized by the absence of eyes, antenna 1 longer than antenna 2 and a curved seta on the inner ramus of male uropod 1. The species were found on caves located in two private properties, both under the impact of agricultural activities, which demonstrates a potential threat to these subterranean environments.

  2. New tryphosine amphipods from Australian waters (Crustacea, Amphipoda, Lysianassoidea, Lysianassidae, Tryphosinae).

    PubMed

    Lowry, J K; Kilgallen, N M

    2014-07-30

    We report seven tryphosine genera (two new) from Australian waters for the first time and describe 13 new species: Cedrosella cito sp. nov.; Lysianella lui sp. nov.; Lysianella moonamoona sp. nov.; Microlysias soela sp. nov.; Paralysianopsis capricornia sp. nov.; Paralysianopsis dandenong sp. nov.; Paralysianopsis pomona sp. nov.; Paralysianopsis ruffoi sp. nov.; Patonga nona gen. nov., sp. nov.; Tasmanosa tasman gen. nov., sp. nov.; Tasmanosa toogooloo sp. nov.; Tryphosites colmani sp. nov.; Tryphosites psittacus sp. nov. Rhinolabia is considered to be a junior synonymy of Paralysianopsis. Paralysianopsis elliotti (Lowry & Stoddart, 1995b) and P. cf. jebbi (Lowry & Stoddart, 1995b), previously known from Papua New Guinea are also reported from eastern Australia. The type species of each genus is also catalogued and illustrated. 

  3. A new species of the genus Rhinoecetes Just, 1983 (Crustacea: Amphipoda: Ischyroceridae) from Japan.

    PubMed

    Kodama, Masafumi; Ohtsuchi, Naoya; Kon, Koetsu

    2016-09-19

    A new species of ischyrocerid amphipods, Rhinoecetes spinicaudus sp. nov., is described from Nabeta Bay, southeast coast of Izu Peninsula, central Japan. This new species can be distinguished from the other congeners by the presence of spinulation on the lateral margins of uropod I rami, row of small robust setae on uropod II ramus, and single robust seta on uropod III ramus. More detailed distinguishing characters from R. albomaculosus are also discussed. This is the first record of the genus Rhinoecetes from Japan. Key to all the species of Rhinoecetes is provided.

  4. Gregarines (Apicomplexa) and microsporidians (Microsporidia) of native and invasive gammarids (Amphipoda, Gammaroidea), occurring in Poland.

    PubMed

    Ovcharenko, Mykola; Codreanu-Bălcescu, Doina; Grabowski, Michal; Konopacka, Alicja; Wita, Irena; Czaplińska, Urszula

    2009-01-01

    The goal of our study was to recognize microparasites of alien gammarids inhabiting Polish inland and coastal waters versus those infecting local species. Twenty two localities including the Vistula, Oder and Bug Rivers, Vistula Lagoon, Gosławskie Lake, littoral of the Baltic Sea, as well as small rivers draining directly to the sea were investigated. In total, over 5000 individuals of 14 species of gammarids were collected and analyzed using light and electron microscopy. The studies have revealed five named and seven unnamed species of gregarines (Apicomplexa, Gregarinidae) as well as three named and seven unnamed species of microsporidians (Microsporidia, Nosematidae, Thelohaniidae) infecting six native and four invasive gammarid host species. All the above microparasites were new to Poland. Four species of gregarines (Uradiophora ramosa, U. longissima, Cephaloidophora similis, C. mucronata) and four microsporidians (Nosema dikerogammari, N. pontogammari, Thelohania sp. 2, Thelohania sp. 5) were associated with hosts of Ponto-Caspian origins. Evidently, these microparasites were transported to the area through the range expansion of their invasive hosts. Gregarines Cephaloidophora sp. 1 and Uradiophora sp. 1 were registered only in North American Gammarus tigrinus. Uradiophoera ramosa infects Ponto-Caspian (P. robustoides, D. villosus) and North-Americah hosts (G. tigrinus).

  5. Cheirimedon foscae sp. nov. (Amphipoda: Lysianassidae: Tryphosinae) from the deep sea Campos Basin, Southwestern Atlantic Ocean.

    PubMed

    Siqueira, Silvana Gomes L; Serejo, Cristiana S

    2014-10-15

    A new species of lysianassid amphipod belonging to the genus Cheirimedon was collected on the continental slope of the Campos Basin, the largest oil reserve in Brazilian waters. This is the first record of the genus Cheirimedon from the Atlantic Ocean, which was previously restricted to the Antarctic and Tasmanian sea. The new species is fully illustrated and compared with related species. Additionally, a world key to the Cheirimedon species is provided. 

  6. Survey of Biofouling an Australian Navy Ships: Crustacea; Isopoda and Amphipoda; Caprellidea

    DTIC Science & Technology

    2008-01-01

    the digestive system of terrestrial isopods. Journal of Zoology 217:599-627, 1989. DSTO-TR-2098 47 H. J. Hansen. Studies on Arthropoda II. On...the comparitive morphology of the appendages in the Arthropoda . In: A Crustacea, Copenhagen:Gyldendalske Boghandel, 1925, p. 1-175. K. Harrison and

  7. A new species of Eusirus from Jeju Island, Korea (Crustacea, Amphipoda, Eusiridae)

    PubMed Central

    Jung, Tae Won; Kim, Min-Seop; Soh, Ho-Young; Yoon, Seong Myeong

    2016-01-01

    Abstract A new eusirid amphipod, Eusirus bulbodigitus sp. n., from Jeju Island, Korea is described with a detailed description and illustrations. Eusirus bulbodigitus sp. n. shows common features with the five known eusirid amphipods Eusirus abyssi Stephensen, 1944, Eusirus columbianus Bousfield & Hendrycks, 1995, Eusirus hirayamae Bousfield & Hendrycks, 1995, Eusirus laticarpus Chevreux, 1906, and Eusirus parvus Pirlot, 1934, such as the mandibular palp article 3 bearing a group of setae laterally. However, this new species is differentiated by the combination of the following characteristics: the eyes are poorly developed, the propodus on pereopod 4 is slightly shorter, the inner margin of dactylus on pereopod 4 is swollen, the length of pereopods 5–7 is moderate, the urosomite 1 has a dorsal protrusion distally, and the telson is shallowly cleft. This is the first record of the genus Eusirus Krøyer, 1845 from Korean waters. PMID:28138283

  8. Recovery of known-age Hyalella azteca (Amphipoda) from sediment toxicity tests

    SciTech Connect

    Tomasovic, M.J.; Dwyer, F.J.; Greer, I.E.; Ingersoll, C.G.

    1995-07-01

    Recovery of 1-, 7-, 14-, or 21-d-old Hyalella azteca from sediment was evaluated. Recovery of 1- and 7-d-old amphipods was below an acceptability criterion of 80% survival for sediment tests. Another important aspect to consider when conduction sediment tests with H. azteca is defining mortality. A second study was conducted to evaluate the decomposition rate of dead amphipods in sediment. Regardless of sediment type, {ge}90% of the amphipods started to break apart within 12h of death; specifically, the head separates from the body. Therefore, if an immobile amphipod with its head and body intact is recovered in sieved material, it was probably alive within 12 h of the end of the test (an amphipod may be alive before sieving but may die during the sieving process). However, immobile amphipods removed from the sediment surface before sieving are known to be dead.

  9. Age-related differential sensitivity to cadmium in Hyalella curvispina (Amphipoda) and implications in ecotoxicity studies.

    PubMed

    García, M E; Rodrígues Capítulo, A; Ferrari, L

    2010-07-01

    The standardization of toxicity tests requires the selection of the most suitable test species and their developmental stages, as well as the selection of the appropriate assay matrix and the evaluation of the sensitivity of the test species to the reference toxicants. International protocols recommend the use of the amphipod Hyalella azteca from the Northern Hemisphere for sediment toxicity tests. We selected the widely distributed amphipod Hyalella curvispina, representative of pleustonic, epiphitic and zoobenthic assemblages in austral South America, as test species to be used in regional studies. Our goals were to evaluate the sensitivity of three developmental stages of H. curvispina to cadmium as a reference toxicant and to select the most suitable age and exposure time for aquatic ecotoxicity assessment. The three ages were highly susceptible to cadmium, with sensitivities: neonates > adults > juveniles. Our results validate the use of the native H. curvispina as a standard species for ecotoxicological assessment studies.

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

    PubMed

    Colla, María Florencia; César, Inés Irma

    2015-01-01

    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.

  11. 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

  12. 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

  13. Pairing and reproductive success in two sympatric species of Hyalella (Crustacea, Amphipoda, Dogielinotidae) from southern Brazil

    NASA Astrophysics Data System (ADS)

    da Silva Castiglioni, Daniela; Bond-Buckup, Georgina

    2008-01-01

    This study aimed at characterizing pairing and reproductive success in relation to male and female sizes of the sympatric freshwater gammarideans Hyalella pleoacuta and H. castroi from southern Brazil. These amphipods exhibit precopulatory mate guarding, in which a male will carry a potential mate beneath its ventral surface, guarding the female for several days until it molts and lays its eggs. The specimens were collected monthly with nets, from November 2003 to July 2004 in two trout aquaculture ponds at Sítio Vale das Trutas locality, São José dos Ausentes County, southern Brazil. The precopulatory pairs and ovigerous females were identified and separated in the field. In the laboratory, they were measured (cephalothorax length in mm), using a micrometer eyepiece in a stereoscopic microscope. Pairing success was estimated from the proportion of mating males and females related to their respective non-pairing individuals by size classes. Reproductive success was estimated from egg production. The mean cephalothorax length of paired males was larger than that of the unpaired males. For females, however, body size not affect pairing success for either species, because mean cephalothorax length of paired females did not differ significantly from unpaired females. Paired and unpaired males of both species of Hyalella were larger than the females. Positive assortative mating by size was observed in both species; i.e., larger males tended to pair with larger females. Male pairing success increased sharply with size. In both species, reproductive success in males increased with body size; however, the females of intermediate size classes showed greater reproductive success. This result supports the hypothesis that loading constraints play a part in structuring size-assortative pairing in these species.

  14. Ecological traits of two sympatric species of Hyalella Smith, 1874 (Crustacea, Amphipoda, Dogielinotidae) from southern Brazil

    NASA Astrophysics Data System (ADS)

    da Silva Castiglioni, Daniela; Buckup, Georgina Bond

    2008-01-01

    This work was performed with the aim to test theoretical predictions regarding that the sympatric species Hyalella pleoacuta and H. castroi might show distinct population biology to facilitate its coexistence. The specimens were collected monthly with nets from August 2003 through July 2004 in two trout ponds at Sítio Vale das Trutas locality, São José dos Ausentes County, southern Brazil. In the laboratory, the specimens were measured as cephalothorax length (mm), being the sex and ovigerous conditions checked. The species H. pleoacuta was 2.94 times more frequent than H. castroi. Males were significantly greater in size than females ( H. pleoacuta—males: 0.74 ± 0.002 mm and females: 0.66 ± 0.001 mm; H. castroi—males: 0.84 ± 0.00 mm and females: 0.72 ± 0.003 mm). Males and females of H. castroi showed a greater mean body size than H. pleoacuta. Sexual maturity was attained at 0.53 mm in males and 0.48 mm in females of H. pleoacuta, and 0.72 mm in males and 0.67 mm in females of H. castroi. The frequency distribution in size classes was usually bimodal in H. pleoacuta and polymodal in H. castroi throughout the year. Sex ratio was female-biased in either species of Hyalella. Ovigerous females (carrying eggs or juveniles in the marsupium) were collected throughout the year in both Hyalella species, but H. pleoacuta and H. castroi were found with more frequency during the winter and fall, respectively. Recruitment occurred in all months of sampling, the juvenile frequency being more than 50% of the amphipods collected in almost all months in both species. The biological differences (especially body size, size at sexual maturity, number of specimens collected and reproductive peak) and microhabitat specialization can be facilitating factors in the coexistence of H. pleoacuta and H. castroi in artificial ponds raising trout.

  15. 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).

  16. 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

  17. On some Haploops species collected in the North Atlantic Ocean with the description of Haploops islandica n. sp. (Crustacea: Gammaridea: Ampeliscidae) [Contribution to the knowledge of the Haploops genus. 8.].

    PubMed

    Kaim-Malka, R A; Bellan-Santini, D; Dauvin, J-C

    2016-10-28

    Four Haploops species collected in the North Atlantic Ocean are studied. One of them, H. islandica is a new species for the science. The three other species, H. carinata, H. setosa, H. robusta, were described from a long time, but many confusions exist about these species because their morphological nearness. The four species are described and illustrated in detail, and their distribution around the Iceland is specified. A key of the 23 species known nowadays is given permetting to separate the different species of the Haploops genus.

  18. Detection of viral hemorrhagic septicemia virus (VHSV) from Diporeia spp. (Pontoporeiidae, Amphipoda) in the Laurentian Great Lakes, USA.

    PubMed

    Faisal, Mohamed; Winters, Andrew D

    2011-01-06

    The mode of viral hemorrhagic septicemia virus (VHSV) transmission in the Great Lakes basin is largely unknown. In order to assess the potential role of macroinvertebrates in VHSV transmission, Diporeia spp., a group of amphipods that are preyed upon by a number of susceptible Great Lakes fishes, were collected from seven locations in four of the Great Lakes and analyzed for the presence of VHSV. It was demonstrated that VHSV is present in some Diporeia spp. samples collected from lakes Ontario, Huron, and Michigan, but not from Lake Superior. Phylogenetic comparison of partial nucleoprotein (N) gene sequences (737 base pairs) of the five isolates to sequences of 13 other VHSV strains showed the clustering of Diporeia spp. isolates with the VHSV genotype IVb. This study reports the first incidence of a fish-pathogenic rhabdovirus being isolated from Diporeia, or any other crustacean and underscores the role macroinvertebrates may play in VHSV ecology.

  19. 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.

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

    PubMed

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

    2017-06-17

    Gammarus fossarum is an often-abundant crustacean detritivore that contributes importantly to leaf litter breakdown in oligotrophic, mainly heterotrophic, headwater streams. This species requires large amounts of Ca to moult, thus allowing growth and reproduction. Because resource quality is tightly coupled to the organism's growth and physiological status, we hypothesised that low Ca concentration [Ca] and low food resource quality (low phosphorus [P] and/or reduced highly unsaturated fatty acid [HUFA] contents) would interactively impair molecular responses (gene expression) and reproduction of G. fossarum. To investigate the effects of food resources quality, we experimentally manipulated the P content of sycamore leaves and also used diatoms because they contain high amounts of HUFAs. Three resource quality treatments were tested: low quality (LQ, unmanipulated leaves: low P content), high quality 1 (HQ1; P-manipulated leaves: high P content), and high quality 2 (unmanipulated leaves supplemented with a pellet containing diatoms: high P and HUFA content). Naturally, demineralised stream water was supplemented with CaSO4 to obtain three Ca concentrations (2, 3.5, and 10.5 mg Ca L(-1)). For 21 days, pairs of G. fossarum were individually exposed to one of the nine treatments (3 [Ca] × 3 resource qualities). At the individual level, strong and significant delays in moult stage were observed in gammarids exposed to lower [Ca] and to lower resource quality, with additive effects lengthening the duration of the reproductive cycle. Effects at the molecular level were investigated by measuring expression of 12 genes involved in energy production, translation, or Ca or P homeostasis. Expression of ATP synthase beta (higher in HQ2), calcified cuticle protein (higher in HQ1 and HQ2), and tropomyosin (higher in HQ2 compared to HQ1) was significantly affected by resource quality, and significant additive effects on Ca transporting ATPase expression were induced by [Ca] and resource quality (higher for low [Ca] and higher resource quality). These results highlight the potential drastic deleterious effects of water [Ca] depletion on G. fossarum physiology, populations, and ecosystem functioning, especially in oligotrophic environments.

  1. 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

    2016-04-06

    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.

  2. 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.

  3. Cryptorchestia ruffoi sp. n. from the island of Rhodes (Greece), revealed by morphological and phylogenetic analysis (Crustacea, Amphipoda, Talitridae)

    PubMed Central

    Davolos, Domenico; Matthaeis, Elvira De; Latella, Leonardo; Vonk, Ronald

    2017-01-01

    Abstract A new Cryptorchestia species, Cryptorchestia ruffoi Latella & Vonk, sp. n. from the island of Rhodes in south-eastern Greece, can be distinguished on the basis of morphological and phylogenetic data. Morphological analysis and DNA sequencing of mitochondrial and nuclear protein-coding genes indicated that this species is related to Cryptorchestia cavimana (Cyprus) and Cryptorchestia garbinii (Mediterranean regions, with a recent northward expansion). Results supported a genetic separation between the Cryptorchestia species of the east Mediterranean regions and those of the northeast Atlantic volcanic islands examined in this study (Cryptorchestia canariensis, Cryptorchestia gomeri, Cryptorchestia guancha, and Cryptorchestia stocki from the Canary islands, Cryptorchestia monticola from Madeira, and Cryptorchestia chevreuxi from the Azores). The Mediterranean and Atlantic Cryptorchestia species appear to be also morphologically distinct. Cryptorchestia ruffoi sp. n., Cryptorchestia cavimana, Cryptorchestia garbinii, and Cryptorchestia kosswigi (Turkish coast) clearly have a small lobe on the male gnathopod 1 merus. This character was the main diagnostic difference between Cryptorchestia (sensu Lowry, 2013) and Orchestia. However, among the six northeast Atlantic island Cryptorchestia species only Cryptorchestia stocki has a small lobe on the merus of gnathopod 1. Reduction or loss of the lobe in the Atlantic Island species cannot be ruled out; however, molecular phylogenetic analysis leads us to presume that this lobe independently evolved between the east Mediterranean Cryptorchestia species and Cryptorchestia stocki from Gran Canaria. PMID:28331390

  4. Under the volcano: phylogeography and evolution of the cave-dwelling Palmorchestia hypogaea (Amphipoda, Crustacea) at La Palma (Canary Islands).

    PubMed

    Villacorta, Carlos; Jaume, Damià; Oromí, Pedro; Juan, Carlos

    2008-01-31

    The amphipod crustacean Palmorchestia hypogaea occurs only in La Palma (Canary Islands) and is one of the few terrestrial amphipods in the world that have adapted to a strictly troglobitic life in volcanic cave habitats. A surface-dwelling closely related species (Palmorchestia epigaea) lives in the humid laurel forest on the same island. Previous studies have suggested that an ancestral littoral Orchestia species colonized the humid forests of La Palma and that subsequent drought episodes in the Canaries reduced the distribution of P. epigaea favouring the colonization of lava tubes through an adaptive shift. This was followed by dispersal via the hypogean crevicular system. P. hypogaea and P. epigaea did not form reciprocally monophyletic mitochondrial DNA clades. They showed geographically highly structured and genetically divergent populations with current gene flow limited to geographically close surface locations. Coalescence times using Bayesian estimations assuming a non-correlated relaxed clock with a normal prior distribution of the age of La Palma, together with the lack of association of habitat type with ancestral and recent haplotypes, suggest that their adaptation to cave life is relatively ancient. The data gathered here provide evidence for multiple invasions of the volcanic cave systems that have acted as refuges. A re-evaluation of the taxonomic status of the extant species of Palmorchestia is needed, as the division of the two species by habitat and ecology is unnatural. The information obtained here, and that from previous studies on hypogean fauna, shows the importance of factors such as the uncoupling of morphological and genetic evolution, the role of climatic change and regressive evolution as key processes in leading to subterranean biodiversity.

  5. Taxonomic relationship between two Gammarus species, G. nipponensis and G. sobaegensis (Amphipoda: Gammaridae), with description of a new species.

    PubMed

    Tomikawa, Ko; Soh, Ho Young; Kobayashi, Norio; Yamaguchi, Aika

    2014-10-20

    To assess the taxonomic relationship between G. nipponensis and G. sobaegensis, morphological features and molecular phylogenetic relationships using the nuclear 28S rRNA and the mitochondrial COI genes were examined. Detailed morphological observations revealed that G. nipponensis and G. sobaegensis were clearly distinguishable. In addition to the morphological differences, these two species were genetically diverged. In the course of this study, an undescribed species was found from Tsushima and Iki Islands and described here as G. mukudai. In the molecular phylogenetic analyses, monophyletic relationships of G. nipponensis, G. sobaegensis, and G. mukudai were shown but relationships among three species were unclear due to low statistical supports. Phylogeography of G. nipponensis, G. sobaegensis, and G. mukudai were discussed. 

  6. Under the volcano: phylogeography and evolution of the cave-dwelling Palmorchestia hypogaea (Amphipoda, Crustacea) at La Palma (Canary Islands)

    PubMed Central

    Villacorta, Carlos; Jaume, Damià; Oromí, Pedro; Juan, Carlos

    2008-01-01

    Background The amphipod crustacean Palmorchestia hypogaea occurs only in La Palma (Canary Islands) and is one of the few terrestrial amphipods in the world that have adapted to a strictly troglobitic life in volcanic cave habitats. A surface-dwelling closely related species (Palmorchestia epigaea) lives in the humid laurel forest on the same island. Previous studies have suggested that an ancestral littoral Orchestia species colonized the humid forests of La Palma and that subsequent drought episodes in the Canaries reduced the distribution of P. epigaea favouring the colonization of lava tubes through an adaptive shift. This was followed by dispersal via the hypogean crevicular system. Results P. hypogaea and P. epigaea did not form reciprocally monophyletic mitochondrial DNA clades. They showed geographically highly structured and genetically divergent populations with current gene flow limited to geographically close surface locations. Coalescence times using Bayesian estimations assuming a non-correlated relaxed clock with a normal prior distribution of the age of La Palma, together with the lack of association of habitat type with ancestral and recent haplotypes, suggest that their adaptation to cave life is relatively ancient. Conclusion The data gathered here provide evidence for multiple invasions of the volcanic cave systems that have acted as refuges. A re-evaluation of the taxonomic status of the extant species of Palmorchestia is needed, as the division of the two species by habitat and ecology is unnatural. The information obtained here, and that from previous studies on hypogean fauna, shows the importance of factors such as the uncoupling of morphological and genetic evolution, the role of climatic change and regressive evolution as key processes in leading to subterranean biodiversity. PMID:18234125

  7. Diversification of Ponto-Caspian aquatic fauna: morphology and molecules retrieve congruent evolutionary relationships in Pontogammarus maeoticus (Amphipoda: Pontogammaridae).

    PubMed

    Nahavandi, Nahid; Ketmaier, Valerio; Plath, Martin; Tiedemann, Ralph

    2013-12-01

    The geological history of the Ponto-Caspian region, with alternating cycles of isolation and reconnection among the three main basins (Black and Azov Seas, and the more distant Caspian Sea) as well as between them and the Mediterranean Sea, profoundly affected the diversification of its aquatic fauna, leading to a high degree of endemism. Two alternative hypotheses on the origin of this amazing biodiversity have been proposed, corresponding to phases of allopatric separation of aquatic fauna among sea basins: a Late Miocene origin (10-6 MYA) vs. a more recent Pleistocene ancestry (<2 MYA). Both hypotheses support a vicariant origin of (1) Black+Azov Sea lineages on the one hand, and (2) Caspian Sea lineages on the other. Here, we present a study on the Ponto-Caspian endemic amphipod Pontogammarus maeoticus. We assessed patterns of divergence based on (a) two mitochondrial and one nuclear gene, and (b) a morphometric analysis of 23 morphological traits in 16 populations from South and West Caspian Sea, South Azov Sea and North-West Black Sea. Genetic data indicate a long and independent evolutionary history, dating back from the late Miocene to early Pleistocene (6.6-1.6 MYA), for an unexpected, major split between (i) a Black Sea clade and (ii) a well-supported clade grouping individuals from the Caspian and Azov Seas. Absence of shared haplotypes argues against either recent or human-mediated exchanges between Caspian and Azov Seas. A mismatch distribution analysis supports more stable population demography in the Caspian than in the Black Sea populations. Morphological divergence largely followed patterns of genetic divergence: our analyses grouped samples according to the basin of origin and corroborated the close phylogenetic affinity between Caspian and Azov Sea lineages. Altogether, our results highlight the necessity of careful (group-specific) evaluation of evolutionary trajectories in marine taxa that should certainly not be inferred from the current geographical proximity of sea basins alone. Copyright © 2013 Elsevier Inc. All rights reserved.

  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

    2016-07-08

    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.

  9. 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.

  10. Photoresponses of the compound eye of the sandhopper Talitrus saltator (Crustacea, Amphipoda) in the ultraviolet-blue range.

    PubMed

    Ugolini, A; Borgioli, G; Galanti, G; Mercatelli, L; Hariyama, T

    2010-08-01

    The semi-terrestrial sandhopper Talitrus saltator uses celestial visual cues to orient along the sea-land axis of the beach. Previous spectral-filtering experiments suggested that it perceives directional information from wavelengths in the ultraviolet (UV)-blue range. Binary choice experiments between dark and UV (380-nm) light carried out on dark-adapted individuals of T. saltator showed photopositive movement to UV. Morphologically, each ommatidium in the eye consists of five retinula cells, four large and one small. In electroretinogram experiments, sensitivity of the dark-adapted eye is dominated by a receptor maximally sensitive at about 390-450 nm and secondarily sensitive at about 500-550 nm. Selective light-adaptation experiments at 580 nm showed the apparent sensitivity decreasing at around the secondary sensitive range, thus disclosing the existence of UV-blue photoreceptor cells. Here the existence of UV-blue detection is confirmed, and evidence is provided that green and UV-blue visual pigments are located in the large and small retinula cells, respectively.

  11. Waterborne toxicity and diet-related effects of fungicides in the key leaf shredder Gammarus fossarum (Crustacea: Amphipoda).

    PubMed

    Zubrod, J P; Englert, D; Wolfram, J; Wallace, D; Schnetzer, N; Baudy, P; Konschak, M; Schulz, R; Bundschuh, M

    2015-12-01

    Animals involved in leaf litter breakdown (i.e., shredders) play a central role in detritus-based stream food webs, while their fitness and functioning can be impaired by anthropogenic stressors. Particularly fungicides can affect shredders via both waterborne exposure and their diet, namely due to co-ingestion of adsorbed fungicides and shifts in the leaf-associated fungal community, on which shredders' nutrition heavily relies. To understand the relevance of these effect pathways, we used a full 2×2-factorial test design: the leaf material serving as food was microbially colonized for 12 days either in a fungicide-free control or exposed to a mixture of five current-use fungicides (sum concentration of 62.5μg/L). Similarly, the amphipod shredder Gammarus fossarum was subjected to the same treatments but for 24 days. Waterborne exposure reduced leaf consumption by ∼20%, which did not fully explain the reduction in feces production (∼30%), indicating an enhanced utilization of food to compensate for detoxification mechanisms. This may also explain the reduced feces production (∼10%) of gammarids feeding on fungicide-exposed leaves. The reduction may, however, also be caused by a decreased nutritious quality of the leaves indicated by a reduced species richness (∼40%) of leaf-associated fungi. However, compensation for these effects by Gammarus was seemingly incomplete, since both waterborne exposure and the consumption of the fungicide-affected diet drastically reduced gammarid growth (∼110% and ∼40%, respectively). Our results thus indicate that fungicide mixtures have the potential for detrimental implications in aquatic ecosystem functioning by affecting shredders via both effect pathways. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. 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.

  13. 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...

  14. 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...

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

    PubMed

    Pavesi, Laura; Tiedemann, Ralph; De Matthaeis, Elvira; Ketmaier, Valerio

    2013-04-25

    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. 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. 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.

  16. 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

  17. 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

  18. 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

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

    PubMed

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

    2016-10-19

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

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

  1. Behavior of Corophium volutator (Crustacea, Amphipoda) exposed to the water-accommodated fraction of oil in water and sediment.

    PubMed

    Kienle, Cornelia; Gerhardt, Almut

    2008-03-01

    We investigated the short-term effects of the water accommodated fraction (WAF) of weathered Forties crude oil on the behavior of Corophium volutator in the Multispecies Freshwater Biomonitor (MFB). When exposing C. volutator to 25 and 50% WAF in aqueous exposures, hyperactivity with an additional increase in ventilation was detected, whereas exposure to 100% WAF led to hypoactivity (narcosis). In a sediment exposure with 100% WAF, there was an increased tendency toward hyperactivity. In a pulse experiment, hyperactivity appeared at and after a 130-min exposure to 50% WAF in a majority of cases. Our experiments suggest that the behavior of C. volutator as measured in the MFB may be an appropriate parameter for coastal monitoring.

  2. Sinocorophium hangangense sp. n. (Crustacea, Amphipoda, Corophiidae), a new species from Korea, with a key to the genus Sinocorophium

    PubMed Central

    Kim, Young-Hyo

    2012-01-01

    Abstract A new species of the corophiid gammaridean amphipod belonging to the genus Sinocorophium Bousfield & Hoover was collected from the lower reaches of the Han River in Gyeonggi-do, Korea. A relatively large body size and morphology of the uropods 1 and 3 are the major characteristics which serve to distinguish the new species from its congeners. The new species is fully illustrated and extensively compared with related species. A key to the species of (Sinocorophium is also provided. PMID:22539911

  3. 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.

  4. 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.

  5. Effects of Microphallus papillorobustus (Platyhelminthes: Trematoda) on serotonergic immunoreactivity and neuronal architecture in the brain of Gammarus insensibilis (Crustacea: Amphipoda).

    PubMed Central

    Helluy, S; Thomas, F

    2003-01-01

    The larval flatworm Microphallus papillorobustus encysts in the protocerebrum of its intermediate host, Gammarus insensibilis, and changes the gammarid's responses to mechanical and photic stimuli. The resulting aberrant escape behaviour renders infected gammarids more susceptible to predation by birds, the definitive hosts of the parasite. We used immunocytochemical methods to explore the mechanisms underlying these subtle behavioural modifications. Whole mounts of gammarid brains were labelled with fluorescent anti-serotonin and anti-synapsin antibodies and viewed using confocal microscopy. Two types of change were observed in infected brains: the intensity of the serotonergic label was altered in specific regions of the brain, and the architecture of some serotonergic tracts and neurons was affected. A morphometric analysis of the distribution of the label showed that serotonergic immunoreactivity was decreased significantly (by 62%) in the optic neuropils, but not in the olfactory lobes, in the presence of the parasite. In addition, the optic tracts and the tritocerebral giant neurons were stunted in parasitized individuals. Published evidence demonstrates changes in serotonin levels in hosts ranging from crustaceans to mammals infected by parasites as diverse as protozoans and helminths. The present study suggests that the degeneration of discrete sets of serotonergic neurons might underlie the serotonergic imbalance and thus contribute to host manipulation. PMID:12769454

  6. 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

    2015-08-21

    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.

  7. A new species of Tongorchestia from Bora Bora in the leeward Society Islands (Crustacea, Amphipoda, Talitridae) .

    PubMed

    Lowry, J K; Bopiah, Arundathi

    2014-03-28

    The new species Tongorchestia borabora sp. nov. is described from Vaitape in Bora Bora, Leeward Islands, Society Islands. This is the first talitrid amphipod reported from Bora Bora and the third species of Tongorchestia from the Western Pacific oceanic islands. Currently Tongorchestia is endemic to oceanic islands in the Western Pacific.

  8. A revision of the lysianassid genus Waldeckia with the description of four new species (Crustacea, Amphipoda, Lysianassidae, Waldeckiinae subfam. nov.).

    PubMed

    Lowry, J K; Kilgallen, N M

    2014-03-31

    Waldeckia Chevreux is a genus of scavenging lysianassoid amphipods with distribution records from Antarctica, Australia, Thailand, Indonesia, Singapore, the Philippines, Vietnam, China and Japan. The genus is revised and diagnosed against all other genera of the Lysianassidae and the subfamily Waldeckiinae is established. All known species are redescribed and a key is provided. Three new species of Waldeckia (W. dempseyae sp. nov., W. tangaroa sp. nov., W. warreen sp. nov.) are described from Australian waters, and one (W. selayarensis sp. nov.) from Indonesia and Australia. Waldeckia crenulata Pirlot, 1936, from the Philippines and Indonesia, is described in detail for the first time. Waldeckia chevreuxi Stebbing, 1910 is placed in the synonymy of W. nitens, and W. elephas is placed in the synonymy of W. nudum. Orchomene orchospina Hirayama, 1986 and O. tomiokaensis Hirayama, 1986 are transferred to Waldeckia. Waldeckia scrupulosa Mateus & Mateus, 1986 cannot be placed in a genus based on the original description. This revision brings the number of species in the genus to 14.

  9. A new species and first record of the genus Shoemakerella Pirlot, 1936 (Crustacea: Amphipoda: Lysianassidae) from Brazil.

    PubMed

    Sorrentino, Rayane; Senna, André R; Lowry, James K

    2014-03-31

    A new species of the genus Shoemakerella Pirlot, 1936 is described for the Southeastern Brazilian continental shelf. The new species is easily recognized from the others in the genus mainly by the shape of the gnathopod 2. This is the first species of Shoemakerella from Brazilian waters.

  10. A co-invasive microsporidian parasite that reduces the predatory behaviour of its host Dikerogammarus villosus (Crustacea, Amphipoda).

    PubMed

    Bacela-Spychalska, K; Rigaud, T; Wattier, R A

    2014-02-01

    Parasites are known to affect the predatory behaviour or diet of their hosts. In relation to biological invasions, parasites may significantly influence the invasiveness of the host population and/or mediate the relationships between the invader and the invaded community. Dikerogammarus villosus, a recently introduced species, has had a major impact in European rivers. Notably, its high position in trophic web and high predatory behaviour, have both facilitated its invasive success, and affected other macroinvertebrate taxa in colonized habitats. The intracellular parasite Cucumispora dikerogammari, specific to D. villosus, has successfully dispersed together with this amphipod. Data presented here have shown that D. villosus infected by this parasite have a reduced predatory behaviour compared with healthy individuals, and are much more active suggesting that the co-invasive parasite may diminish the predatory pressure of D. villosus on newly colonized communities.

  11. 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.

  12. Infection pattern of two sympatric acanthocephalan species in the amphipod Hyalella patagonica (Amphipoda: Hyalellidae) from Lake Mascardi (Patagonia, Argentina).

    PubMed

    Rauque, Carlos A; Semenas, Liliana

    2007-05-01

    The aim of the present study was to describe the infection pattern of the acanthocephalans Acanthocephalus tumescens and Corynosoma sp. co-occurring in the intermediate host the amphipod Hyalella patagonica. Samples were collected monthly from June 2002 to May 2004 from Lake Mascardi. Amphipods were measured and classified by developmental stages. Single and double infections of larval acanthocephalans were recorded and prevalence and mean intensity were calculated. An annual life cycle of H. patagonica could be inferred with recruitment of juveniles from spring to autumn. Males and females were found all year round but females were significantly more abundant. Single infections were mainly found in smaller juvenile amphipods during winter for A. tumescens and in intermediate and large male amphipods during spring and summer for Corynosoma sp. Double infections showed low values and were mainly found in intermediate sized amphipods during spring. A segregation of the infection by season, size and developmental stages of the host was recorded and would tend to avoid competition considering these two acanthocephalan species have different definitive hosts: fishes for A. tumescens and aquatic birds for Corynosoma sp.

  13. 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.

  14. 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

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

    PubMed Central

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

    2016-01-01

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

  16. 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.

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

    USGS Publications Warehouse

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

    2010-01-01

    Gammarus lacustris and Hyalella azteca (hereafter G. lacustris and H. azteca, respectively) are important components of secondary production in wetlands and shallow lakes of the upper Midwest, USA. Within the past 50 years, amphipod densities have decreased while occurrences of fish and intensity of agricultural land use have increased markedly across this landscape. We investigated influences of fish, sedimentation, and submerged aquatic vegetation (SAV) on densities of G. lacustris and H. azteca in semipermanent and permanent wetlands and shallow lakes (n = 283) throughout seven eco-physiographic regions of Iowa, Minnesota, and North Dakota during 2004-2005. G. lacustris and H. azteca densities were positively correlated with densities of SAV (P<0.001 and P<0.001, respectively). Both species were negatively correlated with densities of large fish (non-Cyprinidae; P = 0.01 and P = 0.013, respectively) and with high densities of fathead minnows (Pimephales promelas; P<0.001 and P = 0.033, respectively). H. azteca densities also were negatively correlated with densities of small fish (e.g., other minnows [Cyprinidae] and sticklebacks [Gasterosteidae]; P = 0.048) and common carp (Cyprinus spp.; P = 0.022). G. lacustris densities were negatively correlated with high levels of suspended solids (an index for sedimentation; P<0.001). H. azteca densities were positively correlated with the width of upland-vegetation buffers (P = 0.004). Our results indicate that sedimentation and fish reduce amphipod densities and may contribute to the current low densities of amphipods in the upper Midwest. Thus, removing/excluding fish, and providing a thick buffer of upland vegetation around wetlands may help restore amphipod densities and wetland and water quality within this landscape. ?? Springer Science+Business Media B.V. (outside the USA) 2011.

  18. Survival and precopulatory guarding behavior of Hyalella azteca (Amphipoda) exposed to nitrate in the presence of atrazine.

    PubMed

    Pandey, Ram B; Adams, Ginny L; Warren, Laurie W

    2011-05-01

    Nitrate is one of the most commonly detected contaminants found in aquatic systems with other pesticides such as atrazine. The current study examined potential combined effects of nitrate and atrazine on adults of the freshwater amphipod Hyalella azteca, using survival and precopulatory guarding behavior as toxic endpoints. Although significant differences in acute toxicity with nitrate alone and in binary combination with atrazine (200 µg/L) in water-only tests were not consistently observed for each time point, potential biologically relevant trends in the data were observed. Posttest growth and behavioral observations (10-day period) conducted after 96-hour exposure suggested that atrazine and nitrate at these concentrations did not result in delayed effects on H. azteca. However, when test conditions were modified from standard toxicity tests by feeding amphipods, nitrate was found to be more toxic, with a reduction in median lethal concentration (LC50) values of approximately 80%. We also demonstrated that nitrate exhibits a dose-response effect on precopulatory guarding behavior of H. azteca, suggesting that reproductive effects may occur at environmentally relevant concentrations.

  19. Biomonitoring toxicity of natural sediments using juvenile Hyalella curvispina (Amphipoda) as test species: evaluation of early effect endpoints.

    PubMed

    Giusto, Anabella; Salibián, Alfredo; Ferrari, Lucrecia

    2014-03-01

    The utility of early effect endpoints as biomarkers of ecotoxicity of natural sediments in water-sediment static system was investigated. The particular goal was to evaluate the ecotoxicity of the sediment samples from La Choza stream, located in upper basin of the Reconquista river, the second most polluted river of Argentina. Native juveniles Hyalella curvispina were used as test organisms evaluating survival, growth, oxidative stress parameters (SOD; CAT, TBARS) and the electron transport system (ETS) activity as early toxic effect. This study used methodologies and techniques that allow the assessment of sediment pollution with a native species as test organism and provided data to discuss the viability of sublethal endpoints as tools for freshwater sediment assessment. In spring and in summer two ten-day series of whole-sediment assays were conducted simultaneously: (a) standard assays and (b) biomarkers assays. A control sediment was ran simultaneously in which no--effect on survival was measured. In summer there was a significant increase in length and biomass in both exposed and control groups. In spring an inhibitory effect on growth and an increase in oxidative damage with a concomitant rise in antioxidant defenses, was observed in animals exposed to La Choza sediment. ETS measurement indicated a significant depression of metabolic activity of amphipods exposed to contaminated sediments. The measured biomarkers represent the first record for juvenile H. curvispina exposed to polluted natural sediments under standardized laboratory conditions. The used bioanalytical tools demonstrated higher sensitivity and a more accurate assessment of the effects than those obtained by the standard tests of survival and growth. We propose their adoption in biomonitoring of freshwater sediment toxicity.

  20. 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.

  1. Hyalella cenotensis, a new species of Hyalellidae (Crustacea: Amphipoda) from the Yucatán Peninsula, Mexico.

    PubMed

    Marrón-Becerra, Aurora; Hermoso-Salazar, Margarita; Solís-Weiss, Vivianne

    2014-06-03

    In this study the first blind species of Hyalella for Mexico is described; it is the second in the genus to be recorded there. The new species is closer to the eyeless species: H. anophthalma Ruffo, 1957, H. muerta Baldinger, Shepard & Threloff, 2000, H. caeca Pereira, 1989, H. spelaea Bueno & Cardoso, 2011 in Cardoso et al. 2011, H. imbya Rodrigues & Bueno, 2012 in Rodrigues et al. 2012, but with no curved seta at the inner ramus of uropod 1, antennae 1 shorter than antennae 2, no apical setae on the telson and a characteristic dorsoposterior carina and three pappose setae on the inner plate of maxilla 1. The morphological intraspecific variations that can be found in this genus are discussed.

  2. Cost of reproduction. Changes in metabolism and endosulfan lethality caused by reproductive behavior in Hyalella curvispina (Crustacea: Amphipoda).

    PubMed

    Negro, C L; Castiglioni, M; Senkman, L E; Loteste, A; Collins, P

    2013-04-01

    Biocides are periodically applied in agricultural activities, reaching aquatic systems and acting upon the biota. Amphipods are widely used in toxicity tests because of their sensitivity to a wide range of pollutants. In this work, we report the differential lethality of a widely used pesticide, endosulfan, on the amphipod Hyalella curvispina at two life stages and in three different adult groups, males and females separated by sex and both sexes grouped together. In addition, oxygen consumption of adult groups was determined as a way to estimate the role of behavioral activities and exposure to endosulfan in metabolism shifts. There were no differences between the LC(50) of juveniles and the adults when they were separated by sex (p>0.05). Nevertheless, the LC(50) of adults without sexual differentiation was significantly lower than the LC(50) of juveniles and adults separated by sex (p<0.05). The oxygen consumption rate was higher when adults were grouped without sexual differentiation in the control group. The exposure to low concentrations of endosulfan causes an increase in oxygen consumption in all the treatments. The sexual behavior increased the metabolism and the sensitivity to endosulfan. In future evaluations, adults grouped without sexual differentiation, which were the most sensitive group, should be included in order to mimic the environmental conditions. Using only juveniles or adults separated by sex in toxicity tests may inaccurately estimate the lethality of biocides, especially in species with constant reproductive activities.

  3. Seasonal variations of the energy metabolism of two sympatric species of Hyalella (Crustacea, Amphipoda, Dogielinotidae) in the southern Brazilian highlands.

    PubMed

    Dutra, B K; Castiglioni, D S; Santos, R B; Bond-Buckup, G; Oliveira, G T

    2007-09-01

    Aquatic organisms exist in a constantly fluctuating habitat, with changes in photoperiod, temperature, pH, dissolved organic content, dissolved oxygen and food supply. Organisms must alter past of their physiological and biochemical processes to cope with these changes. We compared the effect of seasonal variations in factors related to energy metabolism of two species of sympatric amphipods, Hyalella pleoacuta and Hyalella castroi. The animals were collected monthly from April 2004 through March 2006. Contents of glycogen, proteins, lipids, triglycerides and the levels of lipoperoxidation were determined in males and females throughout the year by using spectrophotometric methods. Observations revealed significant seasonal differences in biochemical composition, as well as differences among sexes and species. Environmental conditions (e.g., trophic conditions) and reproduction are supposed to be the main processes influencing the seasonal patterns of variation in biochemical composition. Both species of Hyalella show ecological and behavioral differences, especially by resources such as food, space and seasonal variations of energy metabolism, which might facilitate their coexistence in the same habitat.

  4. 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.

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

    PubMed

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

    2013-01-01

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

  6. A new genus and species of Cyproideidae (Crustacea: Peracarida: Amphipoda) from a tropical coral reef, SE Gulf of Mexico.

    PubMed

    Ortiz, M; Winfield, I

    2014-05-09

    Sisalia carricarti new genus, new species, is described on specimens collected from the Sisal Coral Reef System, Southern Gulf of Mexico, Mexico. The new genus is most morphologically similar to the genus Paracyproidea, but can be distinguished by the article 2 of antenna 2 peduncle, the peduncle of the uropods and length of rami, and telson. Also, the new genus can be distinguished from the rest 18 genera of the family Cyproideidae by the following characteristics: 3-articulate mandible palp, mandible molar big and triturative; palp on maxilla 2 uniarticulate; article 2 of pereopods 3-7 rectilinear, and urosomites 1-3 not elongated. Sisalia carricarti new genus, new species, represents the second known genus and third species of cyproideid amphipods documented from the Inter-American Sea (Gulf of Mexico and Caribbean Sea), and the 19th genus and 44th species of the world cyproideid fauna. The more significant morphological characters and the geographical distribution of the 19 known genera of cyproideid amphipods are also pointed out.

  7. 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.

  8. 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.

  9. [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.

  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. Detection of Viral Hemorrhagic Septicemia Virus (VHSV) from Diporeia spp. (Pontoporeiidae, Amphipoda) in the Laurentian Great Lakes, USA

    PubMed Central

    2011-01-01

    The mode of viral hemorrhagic septicemia virus (VHSV) transmission in the Great Lakes basin is largely unknown. In order to assess the potential role of macroinvertebrates in VHSV transmission, Diporeia spp., a group of amphipods that are preyed upon by a number of susceptible Great Lakes fishes, were collected from seven locations in four of the Great Lakes and analyzed for the presence of VHSV. It was demonstrated that VHSV is present in some Diporeia spp. samples collected from lakes Ontario, Huron, and Michigan, but not from Lake Superior. Phylogenetic comparison of partial nucleoprotein (N) gene sequences (737 base pairs) of the five isolates to sequences of 13 other VHSV strains showed the clustering of Diporeia spp. isolates with the VHSV genotype IVb. This study reports the first incidence of a fish-pathogenic rhabdovirus being isolated from Diporeia, or any other crustacean and underscores the role macroinvertebrates may play in VHSV ecology. PMID:21210995

  12. TRACKING PYRETHROID TOXICITY IN SURFACE WATER SAMPLES: EXPOSURE DYNAMICS AND TOXICITY IDENTIFICATION TOOLS FOR LABORATORY TESTS WITH HYALELLA AZTECA (AMPHIPODA).

    PubMed

    Deanovic, Linda A; Stillway, Marie; Hammock, Bruce G; Fong, Stephanie; Werner, Inge

    2017-09-09

    Pyrethroid insecticides are commonly used in pest control and are present at toxic concentrations in surface waters of agricultural and urban areas worldwide. Monitoring is challenging due to their high hydrophobicity and low toxicity thresholds, which often fall below the detection limits of analytical methods. Standard daphnid bioassays used in surface water monitoring are not sensitive enough to protect more susceptible invertebrate species such as the amphipod, Hyalella azteca, and chemical loss during toxicity testing is of concern. In this study, we quantified toxicity loss during storage and testing, using both natural and synthetic water, and present a tool to enhance toxic signal strength for improved sensitivity of H. azteca toxicity tests. The average half-life during storage in LDPE cubitainers at 4°C of five pyrethroids (permethrin, bifenthrin, lambda-cyhalothrin, cyfluthrin, esfenvalerate) and one organophosphate (chlorpyrifos; used as reference) was 1.4 d, and piperonyl butoxide (PBO) proved an effective tool to potentiate toxicity. We conclude that toxicity tests on ambient water samples containing these hydrophobic insecticides are likely to underestimate toxicity present in the field, and mimic short pulse rather than continuous exposures. Where these chemicals are of concern, the addition of PBO during testing can yield valuable information on their presence or absence. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

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

    USGS Publications Warehouse

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

    2016-01-01

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

  14. Population histories of right whales (Cetacea: Eubalaena) inferred from mitochondrial sequence diversities and divergences of their whale lice (Amphipoda: Cyamus).

    PubMed

    Kaliszewska, Zofia A; Seger, Jon; Rowntree, Victoria J; Barco, Susan G; Benegas, Rafael; Best, Peter B; Brown, Moira W; Brownell, Robert L; Carribero, Alejandro; Harcourt, Robert; Knowlton, Amy R; Marshall-Tilas, Kim; Patenaude, Nathalie J; Rivarola, Mariana; Schaeff, Catherine M; Sironi, Mariano; Smith, Wendy A; Yamada, Tadasu K

    2005-10-01

    Right whales carry large populations of three 'whale lice' (Cyamus ovalis, Cyamus gracilis, Cyamus erraticus) that have no other hosts. We used sequence variation in the mitochondrial COI gene to ask (i) whether cyamid population structures might reveal associations among right whale individuals and subpopulations, (ii) whether the divergences of the three nominally conspecific cyamid species on North Atlantic, North Pacific, and southern right whales (Eubalaena glacialis, Eubalaena japonica, Eubalaena australis) might indicate their times of separation, and (iii) whether the shapes of cyamid gene trees might contain information about changes in the population sizes of right whales. We found high levels of nucleotide diversity but almost no population structure within oceans, indicating large effective population sizes and high rates of transfer between whales and subpopulations. North Atlantic and Southern Ocean populations of all three species are reciprocally monophyletic, and North Pacific C. erraticus is well separated from North Atlantic and southern C. erraticus. Mitochondrial clock calibrations suggest that these divergences occurred around 6 million years ago (Ma), and that the Eubalaena mitochondrial clock is very slow. North Pacific C. ovalis forms a clade inside the southern C. ovalis gene tree, implying that at least one right whale has crossed the equator in the Pacific Ocean within the last 1-2 million years (Myr). Low-frequency polymorphisms are more common than expected under neutrality for populations of constant size, but there is no obvious signal of rapid, interspecifically congruent expansion of the kind that would be expected if North Atlantic or southern right whales had experienced a prolonged population bottleneck within the last 0.5 Myr.

  15. 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.

  16. Life history and reproductive biology of Corophium volutator (crustacea: amphipoda) and the influence of shorebird predation on population structure in chignecto bay, bay of fundy, Canada

    NASA Astrophysics Data System (ADS)

    Peer, D. L.; Linkletter, L. E.; Hicklin, P. W.

    Intertidal populations of Corophium volutator were sampled over a 17-month period at 5 locations in Chignecto Bay, Bay of Fundy, Canada. This is a macrotidal environment with extensive mudflats. Two generations were produced annually. The lengths of gravid females and brood sized were larger than those previously reported in most European studies. Production was highest during May-September. During late summer (July-September) the larger animals were selectively removed from the population by predatory shorebirds (Charadriiformes) thus modifying the population structure from a bimodal to a unimodal distribution composed of numerous but small animals. Although shorebird predation was extensive, the associated reductions in Corophium densities were temporary-Densities increased following the birds' departure from the study sites in early fall. Frequency distribution histograms of size classes remained unimodal and growth was low, until the next breeding season. Annual net production over 2 one-year periods was 6250 and 3277 mg·m -2 (dry weight).

  17. 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

    2016-05-27

    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.

  18. Infaunal zoogeography and intergeneric character blending: The case of Metaniphargus shiroi sp. nov. (Crustacea: Amphipoda: Hadziidae), from interstitial beach water on Akajima Island, the Kerama Islands, Southwestern Japan.

    PubMed

    Vonk, Ronald; Gable, Michael

    2014-07-01

    A survey of biogenic coralline sands in the littoral fringe of a tropical island in Japan brought a new amphipod species to light. This species represents the first record of the subterranean genus Metaniphargus from the West Pacific. The majority of the species in this genus occur in the Caribbean, but a report from Hawaii and now from Japan defies the endemic Caribbean status it kept for so long. Metaniphargus shiroi sp. nov. is described, and morphological comparisons are made with closely resembling species from Hawaii and the Cayman Islands (genus Metaniphargus), and the Great Barrier Reef and California (genus Dulzura). Involvement of non-congeners in the comparisons is necessary as character overlap is abundant. These comparisons suggest that the presence of form-related body types in the shallow marine interstitial realm is circumtropical and follows habitat suitability rather than sudden dispersal or vicariance events.

  19. 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.

  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. A finding at the Natural History Museum of Florence affords the holotype designation of Orchestia stephenseni Cecchini, 1928 (Crustacea: Amphipoda: Talitridae).

    PubMed

    Brutto, Sabrina Lo

    2017-02-13

    The beach flea Orchestia stephenseni has been originally described by Cecchini twice (1928, 1929) from the La Spezia type locality (northern Tyrrhenian Sea, Italy), and successively re-described by Karaman (1973) and Iaciofano & Lo Brutto (2016).

  2. A new subterranean species of Pseudocrangonyx from China with an identification key to all species of the genus (Crustacea, Amphipoda, Pseudocrangonyctidae)

    PubMed Central

    Zhao, Shuangyan; Hou, Zhonge

    2017-01-01

    Abstract A subterranean species of Pseudocrangonyx elegantulus Hou, sp. n. is described from caves of Wulongdong National Forest Park in Henan Province, China. Pseudocrangonyx elegantulus is characterized by both male and female with calceoli on antenna II; urosomite III dorsal margin without armature; uropod III with peduncle 0.30 times as long as outer ramus and terminal article of the outer ramus a little shorter than adjacent spines; telson cleft 0.27 of its length. Phylogenetic analysis based on 28S and COI sequences supported the species distinctness. A key to the genus Pseudocrangonyx with 22 species and a map of their distributions are provided. PMID:28325961

  3. Parallel reduction in expression, but no loss of functional constraint, in two opsin paralogs within cave populations of Gammarus minus (Crustacea: Amphipoda).

    PubMed

    Carlini, David B; Satish, Suma; Fong, Daniel W

    2013-04-23

    Gammarus minus, a freshwater amphipod living in the cave and surface streams in the eastern USA, is a premier candidate for studying the evolution of troglomorphic traits such as pigmentation loss, elongated appendages, and reduced eyes. In G. minus, multiple pairs of genetically related, physically proximate cave and surface populations exist which exhibit a high degree of intraspecific morphological divergence. The morphology, ecology, and genetic structure of these sister populations are well characterized, yet the genetic basis of their morphological divergence remains unknown. We used degenerate PCR primers designed to amplify opsin genes within the subphylum Crustacea and discovered two distinct opsin paralogs (average inter-paralog protein divergence ≈ 20%) in the genome of three independently derived pairs of G. minus cave and surface populations. Both opsin paralogs were found to be related to other crustacean middle wavelength sensitive opsins. Low levels of nucleotide sequence variation (< 1% within populations) were detected in both opsin genes, regardless of habitat, and dN/dS ratios did not indicate a relaxation of functional constraint in the cave populations with reduced or absent eyes. Maximum likelihood analyses using codon-based models also did not detect a relaxation of functional constraint in the cave lineages. We quantified expression level of both opsin genes and found that the expression of both paralogs was significantly reduced in all three cave populations relative to their sister surface populations. The concordantly lowered expression level of both opsin genes in cave populations of G. minus compared to sister surface populations, combined with evidence for persistent purifying selection in the cave populations, is consistent with an unspecified pleiotropic function of opsin proteins. Our results indicate that phototransduction proteins such as opsins may have retained their function in cave-adapted organisms because they may play a pleiotropic role in other important processes that are unrelated to vision.

  4. 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

    2014-11-18

    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.

  5. A review of the families and genera of the superfamily PLATYSCELOIDEA Bowman & Gruner, 1973 (Crustacea: Amphipoda: Hyperiidea), together with keys to the families, genera and species.

    PubMed

    Zeidler, Wolfgang

    2016-11-13

    The systematics and phylogenetic relationships of the families and genera of the superfamily Platysceloidea are examined, following a thorough examination of the morphology of an example of the type species of each genus, or a substitute species if the true identity of the type species is in doubt. The mouthparts are described for each type species, often for the first time, providing additional characters for phylogenetic analysis. Genera are diagnosed using the taxonomic database program DELTA (Dalwitz et al. 1999). This database is also used for a phylogenetic analysis of the genera using PAUP (Swofford 2000). Proposed taxonomic changes resulting from this study are summarised as follows. The family Pronoidae is restricted to the monotypic genus Pronoe because it has some unique characters not found in any other platysceloidean. Paralycaea, previously in Pronoidae, has characters in common with Amphithyrus and Amphithyropsis gen. nov., a new genus proposed for Paralycaea platycephala Zeidler, 1998 (here re-determined a junior synonym of Tetrathyrus pulchellus Barnard, 1930), and together they form the proposed new family Amphithyridae fam. nov. Eupronoe and Parapronoe, also previously in Pronoidae, are similar in the morphology of the mouthparts, antennae and gnathopoda, and together form the proposed new family Eupronoidae fam. nov. The family Brachyscelidae is restricted to the genus Brachyscelus because Thamneus, previously included in Brachyscelidae, has a number of characters that differ considerably from any other genus of Hyperiidea and it is therefore placed in a family of its own, Thamneidae fam. nov. The status of the family Anapronoidae, for Anapronoe, is confirmed, as is the status of the family Tryphanidae for Tryphana. The family Lycaeidae is limited to Lycaea and Simorhynchotus. The family Oxycephalidae maybe polyphyletic but more work is required to resolve the systematic status of the eight genera currently recognised. Metalycaea globosa Stephensen, 1925, sometimes included in the Oxycephalidae, is confirmed to be a junior synonym of Lycaea serrata Claus, 1879. The family Platyscelidae is restricted to four genera, Platyscelus, Paratyphis, Hemityphis and Tetrathyrus; Amphithyrus having been removed to the new family Amphithyridae. The family Parascelidae is also restricted to four genera, Parascelus, Thyropus, Schizoscelus and Euscelus. Hemiscelus, previously included in this family, is regarded a junior synonym of Hemityphis. Keys are provided for families, genera and all currently known species. All records of associations with gelatinous zooplankton are also documented, providing additional data to help resolve the phylogeny and evolutionary origins of the Hyperiidae.

  6. 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.

  7. Variable orientation within a natural population of the sandhopper Talitrus saltator (Crustacea: Amphipoda) as a response to a variable environment: The case-study of Berkoukesh beach, Tunisia

    NASA Astrophysics Data System (ADS)

    Fanini, Lucia; Scapini, Felicita

    2008-03-01

    Sandy beaches are harsh environments, driving resident arthropod populations to various typical adaptations, particularly behavioural ones. Here we evaluated the effects of seasonal meteorological variability on the behaviour of Talitrus saltator on Berkoukesh beach (N-W Tunisia). The site is characterised by a Mediterranean climate, but is particularly exposed to seasonal winds and storms. The shoreline is in morphodynamic equilibrium. We tested sandhopper Talitrus saltator orientation in April, when sudden rainfall and storms are common, and in June, when as a rule the weather is warm and dry. The results were analysed with circular statistics and multiple regression models adapted to angular distributions, in order to highlight differences in orientation under the various conditions. Depending on the environmental conditions, amphipods from the same population appeared to utilise various orientation strategies as a response to different environmental constraints. The use of a range of behavioural mechanisms (sun-orientation seaward, sun-orientation landward, and phototaxis) resulted in links to the local landscape and to the animals' life cycle. As a general conclusion, we can infer that the behavioural variability found within the same population represents a response to seasonal environmental fluctuation. Such an increase in variability is likely to develop on a beach in dynamic equilibrium, where landscape references are stable, and a variable behaviour represents a strategy for dealing with environmental fluctuations.

  8. 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.

  9. Complicated evolution of the caprellid (Crustacea: Malacostraca: Peracarida: Amphipoda) body plan, reacquisition or multiple losses of the thoracic limbs and pleons.

    PubMed

    Ito, Atsushi; Aoki, Masakazu N; Yahata, Kensuke; Wada, Hiroshi

    2011-08-01

    The Caprellidea (Crustacea) have undergone an interesting morphological evolution from their ancestral gammarid-like form. Although most caprellid families have markedly reduced third and fourth pereopods (the walking thoracic limbs) and pleons (the posterior body parts), one family, Caprogammaridae, has developed pleon with swimming appendages (pleopods), whereas another family, Phtisicidae, possesses well-developed functional third and fourth pereopods. The unique character status of these families implies that there has been reacquisition or multiple losses of both pereopods and the pleon within the Caprellidea lineages. Although the Caprellidea are fascinating animals for the study of morphological evolution, the phylogenetic relationships among the Caprellidea are poorly understood. One obstacle to studying the evolution of the Caprellidea is the difficulty of collecting samples of caprogammarid species. In this study, we obtained live samples of a Caprogammaridae species and confirmed that its pleon and pleopods could perform similar locomotive functions and swimming movements as observed in gammarids. From the phylogenetic analyses on 18S ribosomal RNA gene sequences, we identified three distinct clades of Caprellidea. The ancestral state reconstruction based on the obtained phylogeny suggested that once lost, the third and fourth pereopods were regained in the Phtisicidae, while the pleon was regained in the Caprogammaridae, while we could not exclude the possibility of independent losses. In either case, the caprellid lineage underwent a quite complicated morphological evolution, and possibly the Caprellidea may be an exception to Dollo's law.

  10. A new marine interstitial Psammogammarus (Crustacea, Amphipoda, Melitidae) from Gura Ici Island, off western Halmahera (North Moluccas, Indonesia), and an overview of the genus

    PubMed Central

    Vonk, Ronald; Hoeksema, Bert W.; Jaume, Damià

    2011-01-01

    Abstract Psammogammarus wallacei sp. n. is described from the shallow marine interstitial of a sand and coral rubble beach on the Gura Ici islands (North Moluccas; Indonesia). This is the first record of this circum-tropical genus from SE Asia, with the geographically closest relative inhabiting the Ryukyu archipelago in Japan. The new species is highly distinctive by the display of sexual dimorphism on pleopod II, with the medial margin of the male proximal article of exopod provided with a comb of short, blunt curved spinules; no other representative of the genus is known to display sexually-dimorphic appendages aside of the gnathopods. The new species is also noteworthy by the outline of the palm margin of male gnathopod II, hardly excavated, and by showing a carpus broader than long. An overview of the genus Psammogammarus with 14 species to date is provided. PMID:21998551

  11. Epibiotic rotifers of Gammarus pulex (L.) (Crustacea, Amphipoda), with descriptions of two new species and notes on the terminology of the trophi.

    PubMed

    Smet, Willem H De; Verolet, Michel

    2016-05-03

    The epibiotic rotifers of a Gammarus pulex (L.) collection from the Ardèche, France are reported. Four species were found, of which Cephalodella jersabeki n. sp. and Proales gammaricola n. sp. are new to science and described. The other species, Dicranophorus cambari Wulfert and Embata laticeps (Murray), are commented upon. SEM micrographs of the trophi are presented, and a new or amended terminology is proposed for some diagnostic trophi parts.

  12. Parallel reduction in expression, but no loss of functional constraint, in two opsin paralogs within cave populations of Gammarus minus (Crustacea: Amphipoda)

    PubMed Central

    2013-01-01

    Background Gammarus minus, a freshwater amphipod living in the cave and surface streams in the eastern USA, is a premier candidate for studying the evolution of troglomorphic traits such as pigmentation loss, elongated appendages, and reduced eyes. In G. minus, multiple pairs of genetically related, physically proximate cave and surface populations exist which exhibit a high degree of intraspecific morphological divergence. The morphology, ecology, and genetic structure of these sister populations are well characterized, yet the genetic basis of their morphological divergence remains unknown. Results We used degenerate PCR primers designed to amplify opsin genes within the subphylum Crustacea and discovered two distinct opsin paralogs (average inter-paralog protein divergence ≈ 20%) in the genome of three independently derived pairs of G. minus cave and surface populations. Both opsin paralogs were found to be related to other crustacean middle wavelength sensitive opsins. Low levels of nucleotide sequence variation (< 1% within populations) were detected in both opsin genes, regardless of habitat, and dN/dS ratios did not indicate a relaxation of functional constraint in the cave populations with reduced or absent eyes. Maximum likelihood analyses using codon-based models also did not detect a relaxation of functional constraint in the cave lineages. We quantified expression level of both opsin genes and found that the expression of both paralogs was significantly reduced in all three cave populations relative to their sister surface populations. Conclusions The concordantly lowered expression level of both opsin genes in cave populations of G. minus compared to sister surface populations, combined with evidence for persistent purifying selection in the cave populations, is consistent with an unspecified pleiotropic function of opsin proteins. Our results indicate that phototransduction proteins such as opsins may have retained their function in cave-adapted organisms because they may play a pleiotropic role in other important processes that are unrelated to vision. PMID:23617561

  13. 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

  14. A new Glossocephalus (Crustacea: Amphipoda: Hyperiidea: Oxycephalidae) from deep-water in the Monterey Bay region, California, USA, with an overview of the genus.

    PubMed

    Zeidler, Wolfgang; Browne, William E

    2015-10-05

    A new species of Glossocephalus, G. rebecae sp. nov., is described from deep-water in the Monterey Bay region of California, Eastern Pacific Ocean. It seems to be associated exclusively with the mesopelagic ctenophore Bathocyroe fosteri. This association has been observed from 541-830 m depth. It is readily distinguished from G. milneedwardsi Bovallius, 1887 by the shape of the eye fields. The retina is organised into a crescent-shaped organ, occupying about one-quarter of the back half of the head, with the crystalline cones projecting both anteriorly and laterally. An updated review of the genus is provided, taking into account the new species, together with an overview of G. milneedwardsi, and three new records of associations with ctenophores for G. milneedwardsi. New observations on the interaction of G. milneedwardsi with one of its ctenophore hosts, Mnemiopsis sp., are also documented.

  15. 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

  16. Improvement of the sediment ecosystem following diversion of an intertidal sewage outfall at the Fraser river estuary, Canada, with emphasis on Corophium salmonis (Amphipoda).

    PubMed

    Arvai, J L; Levings, C D; Harrison, P J; Neill, W E

    2002-06-01

    Primary treated sewage effluent from the city of Vancouver, Canada was deposited directly onto the intertidal ecosystem of Sturgeon bank, Fraser river estuary between 1962 and 1988. In response to the degraded sediment conditions an azoic zone developed near the discharge outfall. Effluent discharges into the intertidal zone were almost completely stopped in 1988 with the construction of a submerged outfall. Our studies, conducted between 1994 and 1996, showed considerable improvement in the environment of the mudflat ecosystem, including increased dissolved oxygen, decreased sediment chlorophyll, decreased organic material in the sediment, reduced heavy metals in surficial sediment and increased grain size. The amphipod Corophium salmonis, important in the food web for juvenile salmon and other fish species, recolonized the previously azoic location. At reference stations, C. salmonis density was similar to that observed in previous surveys two decades earlier. Our data strongly suggest that improvement or sediment conditions near the former sewage outfall was a major factor enabling colonization by C. salmonis.

  17. Use of the multispecies freshwater biomonitor to assess behavioral changes of Corophium volutator (Pallas, 1766) (Crustacea, Amphipoda) in response to toxicant exposure in sediment.

    PubMed

    Kirkpatrick, Anita J; Gerhardt, Almut; Dick, Jaimie T A; McKenna, Maria; Berges, John A

    2006-07-01

    Automated sediment toxicity testing and biomonitoring has grown rapidly. This study tested the suitability of the marine amphipod Corophium volutator (Pallas, 1766) for sediment biomonitoring using the Multispecies Freshwater Biomonitor (MFB). Two experiments were undertaken to (1) characterize individual behaviors of C. volutator using the MFB and (2) examine behavioral changes in response to sediment spiked with the pesticide Bioban. Four behaviors were visually identified (walking, swimming, grooming and falling) and characterized in the MFB as different patterns of locomotor activity (0-2 Hz range). Ventilation was not visually observed but was detected by the MFB (2-8 Hz). No clear diel activity patterns were detected. The MFB detected an overall increase in C. volutator locomotor activity after Bioban addition to the sediments (56, 100, 121 mg kg(-1)). C. volutator was more active (both locomotion and ventilation) in the water column than the spiked sediment. C. volutator appears a sensitive and appropriate species for behavioral sediment toxicity assessment and biomonitoring.

  18. 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

    2015-09-14

    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.

  19. Description of a new species of Niphargus (Crustacea: Amphipoda: Niphargidae): the first record of a lake ecomorph in the Carpathian Mountains.

    PubMed

    Petković, Matija; Delić, Teo; Lučić, Luka; Fišer, Cene

    2015-10-01

    We describe and phylogenetically characterize a new species Niphargus mirocensis from Mt. Miroč, eastern Serbia. This species shows distinct morphology typical for a lake ecomorph of niphargid amphipod, i.e. large and stout body, elongated appendages and raptorial gnathopods and presents the first record of this ecomorph in Carpathian Mountains. Phylogenetic analyses based on Cytochrome Oxidase Subunit 1 gene (COI), Histone (H3) and 28S rRNA (28S) suggests that species is nested within a clade of lake ecomorphs spread in Italy and Central Dinaric Region. The new finding is geographic extension of clade's range, the species of which are generally narrow endemics.

  20. 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

    2015-07-10

    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.

  1. Dulichiella celestun, a new species of amphipod (Crustacea: Amphipoda: Melitidae) from the Gulf of Mexico, with a key and zoogeographic remarks for the genus in the western Atlantic.

    PubMed

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

    2014-03-10

    The discovery of a new melitid amphipod in the Celestun Biosphere Reserve (northern Yucatan peninsula, SE Gulf of Mexico) is reported. Dulichiella celestun sp. nov. differs from its congeners by an unique set of characteristics: truncated lateral cephalic lobe, mandibular palp article 1 having inner margin produced distally, carpus longer than the propodus of gnathopod 1, gnathopod 2 propodus distolateral crown with four spines, pereopods 3-7 dactylar unguis anterior margin with two accessory spines, and urosomite 3 bearing four dorsal spines. A key to species and zoogeographical affinities among members of the genus in the western Atlantic are also provided.

  2. Description of a new species of Victoriopisa Karaman & Barnard, 1979 (Crustacea: Amphipoda: Eriopisidae) from China, with a key to the genus Victoriopisa.

    PubMed

    Zhao, Shuangyan; Liu, Cunqi; Hou, Zhonge

    2016-03-30

    Victoriopisa multiartus sp. nov. is described from mangrove in Qi'ao Island, China. The new species differs from the other nine species of the genus Victoriopisa in the gnathopod I sexual dimorphism; propodus palm of gnathopod II with two excavations in female and one excavation in male; and terminal article of outer ramus in uropod III expanded, oval-shaped. A key to the genus Victoriopisa with ten species and a map of their distribution are provided.

  3. 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.

  4. Papuadocus blodiwai gen. nov., sp. nov. (Crustacea: Amphipoda: Maeridae), a new bathyal species associated with sunken wood in the Bismarck Sea (Papua New Guinea).

    PubMed

    Corbari, Laure; Sorbe, Jean Claude

    2015-01-29

    A new species belonging to a new genus of Maeridae, Papuadocus blodiwai gen. nov., sp. nov., is described from bathyal bottoms of the Bismarck Sea (Papua New Guinea). This genus/species can be distinguished from most other known maerids by right and left maxillas 1 with asymmetrical palps and by gnathopod 2 not sexually dimorphic. Its closest relative is the genus Bathyceradocus also characterized by asymmetrical maxillas 1, but differing by the presence of gill on coxae 7. These observations lead to the conclusion that the diagnosis of the family Maeridae has to be amended to receive both Bathyceradocus and Papuadocus genera. All the collected specimens lived in association with sunken wood, at 500-580 m depth.

  5. Description of a new genus and species of the family Melphidippidae Stebbing, 1899 (Crustacea: Amphipoda) from the deep waters of Brazil.

    PubMed

    Marques-Junior, Paulo R; Senna, André R

    2013-01-01

    The species of the amphipod family Melphidippidae are distributed worldwide in marine habitats, but there is no record of this family from Brazil so far. A new genus and species of Melphidippidae are described from Brazilian waters. Stebbingiella gen. nov. is monotypic and is distinguished from the other genera of the family by the presence of: antenna 1 with accessory flagellum 7-articulate, lateral cephalic lobe subacute, with globular eyes extremely produced, reaching beyond the second article of peduncle of antenna 2; gnathopods stout and slightly subchelate; coxae 3 and 4 with strong anterior projection and coxae 5 and 7 with strong posterior projection; telson cleft, not fully movable, with two globular lobes, about 2X wider than long. Stebbingiella globulosa sp. nov. is the first species of Melphidippidae recorded from Brazilian waters.

  6. An illustrated key to the soft-bottom caprellids (Crustacea: Amphipoda) of the Iberian Peninsula and remarks to their ecological distribution along the Andalusian coast

    NASA Astrophysics Data System (ADS)

    Guerra-García, José M.; Navarro-Barranco, Carlos; Corzo, Juan; Cobos-Muñoz, Vanessa; García-Adiego, Emilio M.; Giménez, Francisco Sempere; García-Gómez, J. Carlos

    2013-06-01

    The soft-bottom caprellids of the Iberian Peninsula are revised. Nineteen species have been reported so far, 42 % being endemic to the Mediterranean Sea. The lateral view of all of them is provided, together with an illustrated key for all the species. An ecological study was also conducted during 2007-2010 along the Andalusian coast to explore the relationships of caprellids with abiotic data. A total of 90 stations (0-40 m deep) were sampled and 40 contained caprellids. Along the Atlantic, caprellids were present in only 20 % of the stations, while along the Mediterranean coast, caprellids were present in the 75 % of the sampling sites. Furthermore, the abundance of caprellids was also higher in the Mediterranean coast. The dominant species was Pseudolirius kroyeri (present in 24 stations and showing the highest abundances with 1,780 ind/m2), followed by Phtisica marina (22 stations) and Pariambus typicus (11 stations). According to CCA and BIO-ENV, sediment type, P, pH and oxygen were the parameters that better explained the distribution of caprellids. Although the three dominant species were found in all types of sediment, the univariate approach showed that P. kroyeri was significantly more abundant in fine sediments (silt-clay and very fine sands) than in gross sediments (coarse and very coarse sands). The majority of studies dealing with caprellids from the Iberian Peninsula have been focused on shallow waters and further efforts are needed to explore biodiversity of deeper areas.

  7. Comparing the effectiveness of chronic water column tests with the crustaceans Hyalella azteca (order: Amphipoda) and Ceriodaphnia dubia (order: Cladocera) in detecting toxicity of current-use insecticides.

    PubMed

    Deanovic, Linda A; Markiewicz, Dan; Stillway, Marie; Fong, Stephanie; Werner, Inge

    2013-03-01

    Standard U.S. Environmental Protection Agency laboratory tests are used to monitor water column toxicity in U.S. surface waters. The water flea Ceriodaphnia dubia is among the most sensitive test species for detecting insecticide toxicity in freshwater environments.Its usefulness is limited, however, when water conductivity exceeds 2,000 µS/cm (approximately 1 ppt salinity) and test effectiveness is insufficient. Water column toxicity tests using the euryhaline amphipod Hyalella azteca could complement C. dubia tests; however, standard chronic protocols do not exist. The present study compares the effectiveness of two water column toxicity tests in detecting the toxicity of two organophosphate (OP) and two pyrethroid insecticides: the short-term chronic C. dubia test, which measures mortality and fecundity, and a 10-d H. azteca test, which measures mortality and growth. Sensitivity was evaluated by comparing effect data, and end point variability was evaluated by comparing minimum significant differences. Tests were performed in synthetic water and filtered ambient water to quantify the influence of water matrix on effect concentrations. The H. azteca test detected pyrethroid toxicity far more effectively, while the C. dubia test was more sensitive to OPs. Among endpoints, H. azteca mortality was most robust. The results demonstrate that the H. azteca test is preferable when conductivity of water samples is 2,000 to 10,000 µS/cm or if contaminants of concern include pyrethroid insecticides.

  8. 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

    2015-09-23

    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.

  9. 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

    2016-06-20

    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.

  10. 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.

  11. 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

  12. A new marine interstitial Psammogammarus (Crustacea, Amphipoda, Melitidae) from Gura Ici Island, off western Halmahera (North Moluccas, Indonesia), and an overview of the genus.

    PubMed

    Vonk, Ronald; Hoeksema, Bert W; Jaume, Damià

    2011-01-01

    Psammogammarus wallaceisp. n. is described from the shallow marine interstitial of a sand and coral rubble beach on the Gura Ici islands (North Moluccas; Indonesia). This is the first record of this circum-tropical genus from SE Asia, with the geographically closest relative inhabiting the Ryukyu archipelago in Japan. The new species is highly distinctive by the display of sexual dimorphism on pleopod II, with the medial margin of the male proximal article of exopod provided with a comb of short, blunt curved spinules; no other representative of the genus is known to display sexually-dimorphic appendages aside of the gnathopods. The new species is also noteworthy by the outline of the palm margin of male gnathopod II, hardly excavated, and by showing a carpus broader than long. An overview of the genus Psammogammarus with 14 species to date is provided.

  13. DECLINE IN LAKE ONTARIO POPULATIONS OF BENTHIC MACROINVERTEBRATES

    EPA Science Inventory

    Surveys of benthic macroinvertebrates conducted in Lake Ontario during 1994 and 1997 revealed declines in populations of three major groups of organisms: oligochaetes, sphariids, and Diporeia spp. (Amphipoda), with the most drastic reductions occurring in the latter. Based on phy...

  14. Effects of Surface Texture of Articulated Concrete Mattress Blocks on Their Habitat Value. Lower Mississippi River Environmental Program Report 19

    DTIC Science & Technology

    1992-09-01

    of trichoptera, chironomidae, ephemeroptera, odonata , collembola, amphipoda, isopoda, hydracarinia, gas- tropoda, bivalvia, naididae, hydrozoa...Ephemeroptera Baetis sp. CaenIs sp. Heptagenia sp. Isonychia sp. Stenocron sp. Odonata Neurocordulia moles ta (Continued) 21 Table 1 (Concluded) .Taxonomic

  15. Effects of Reservoir Releases on Water Quality, Macroinvertebrates, and Fish in Tailwaters: Field Study Results.

    DTIC Science & Technology

    1983-02-01

    3.14 Number of samples 10 11 V *Includes Empiciidae, Tipulidae, Tabanidae, Odonata , Hemiptera, Megaloptera, Orthoptera, Nematoda, and Hirudinea. 37...Plecoptera 0 0 25 Coleoptera 18 0 27 Odonata 86 43 156 Hydracarina 670 258 204 Oligochaeta 3,929 612 854 Hirudinea 97 2 22 Nema toda 208 74 44 Amphipoda...Hirudinea, Nematoda, and Gastropoda. Again, typical riverine species such as Trichoptera, Ephemeroptera, ..... Plecoptera, Coleoptera, Odonata , and Amphipoda

  16. 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

    2015-01-12

    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. 

  17. Substrate dependent talitrid amphipods from fragmented beaches on the north coast of Crete (Crustacea, Amphipoda, Talitridae), including a redefinition of the genus Orchestia and descriptions of Orchestia xylino sp. nov. and Cryptorchestia gen. nov.

    PubMed

    Lowry, J K; Fanini, Lucia

    2013-01-01

    Four species of talitrid amphipods (Orchestia montagui Audouin, 1826, Orchestia stephenseni Cecchini, 1928, Orchestia xylino sp. nov. and Talitrus saltator (Montagu, 1808)) are reported from a set of fragmented pocket beaches to the east of Heraklion on the north coast of Crete. Aside from a previous record of O. stephenseni these are the first records of talitrid amphipods from the island of Crete. 2) Along a coastal segment of only 4.36 km, characterised by habitat fragmentation and substrate patchiness, a clear correlation between talitrid species and beach type is indicated. Talitrus saltator occurs only on sandy beaches. Orchestia montagui and O. xylino occur on banquette beaches and O. montagui, O. stephenseni and O. xylino occur on mixed sand/gravel and cobble beaches. 3) The genus Orchestia is redefined and confined to 15 marine supralittoral species from eastern North America, islands in the North-eastern Atlantic, and western-Europe, including the Baltic and the Mediterranean Seas plus a perplexing group in New Zealand. 4) The new genus Cryptorchestia is described, based on nine terrestrial species previously included in the genus Orchestia and occurring in western Europe, the Mediterranean Sea and the Azores and Canary islands in the North-eastern Atlantic. 5) The new species Orchestia xylino sp. nov. is described. 6) An extensive bibliography for the species in this study is provided.

  18. Mexorchestia: a new genus of talitrid amphipod (Crustacea, Amphipoda, Talitridae) from the Gulf of Mexico and Caribbean Sea, with the description of a new species and two new subspecies.

    PubMed

    Wildish, David J; Lecroy, Sara E

    2014-08-26

    Two species of supralittoral Tethorchestia were reported by Bousfield (1984) to occur on the shores of the Gulf of Mexico and closely adjacent waters: T. antillensis Bousfield, 1984 from Quintana Roo, Mexico and an undescribed species, Tethorchestia sp. B of Bousfield (1984), from Florida and the U.S. Gulf coast. In this paper, we rediagnose and illustrate the former taxon based on material from Goodland Bay, Florida, which represents a range extension for that species. We examined the latter taxon from many locations throughout the Gulf of Mexico using classical morphology, epidermal pigment pattern recognition and allometry, reinforced by molecular markers (mitochondrial cytochrome oxidase I, Radulovici 2012), determining that Tethorchestia sp. B represents a new genus and species, comprising two subspecies. The nominate subspecies, Mexorchestia carpenteri carpenteri n. gen., sp. and subsp., is described from Tiger Tail Beach, Florida, based on conventional morphological criteria and its distinctive epidermal pigment patterns. The Tiger Tail Beach ecotope of M. c. carpenteri n. gen., sp. and subsp. was distinct from that of other locations examined in Florida and was associated with epidermal pigment pattern polymorphism, absent at other locations. A second subspecies, distinguished by differences in size, number of articles in the flagellum of antenna 2, the number of marginal setae on oostegite 2 of the female and the number of distal dorsolateral robust setae on the telson, was found in samples from Belize and Mexico. This subspecies is described from material collected at Turneffe Island, Belize, as Mexorchestia carpenteri raduloviciae n. gen., sp. and subsp. Like M. c. carpenteri n. gen., sp. and subsp., this taxon is also associated with epidermal pigment pattern polymorphism. A key is provided for the three currently described species of Tethorchestia (two extant) and two new subspecies of Mexorchestia n.gen. 

  19. 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

    2014-02-26

    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.

  20. 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

    Krapp-Schickel, Traudl

    2011-03-19

    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.

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

    PubMed

    Labay, Vjacheslav S

    2016-08-25

    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.

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

    PubMed

    Smet, Willem H De

    2015-03-31

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

  3. Further records of Amphipoda from Baltic Eocene amber with first evidence of prae-copulatory behaviour in a fossil amphipod and remarks on the taxonomic position of Palaeogammarus Zaddach, 1864.

    PubMed

    Jażdżewski, Krzysztof; Grabowski, Michał; Kupryjanowicz, Janusz

    2014-02-20

    Two pieces of Baltic amber with amphipod inclusions were studied. One of them contained approximately twenty individuals identified as belonging to the extinct genus Palaeogammarus and described as P. debroyeri sp. nov. Interestingly, among the individuals there are two pairs preserved in an evident prae-copula position. This is the first finding of such mating behaviour in fossil amphipods. Based on this behavioural trait and on the observed morphological features, we conclude that the genus Palaeogammarus should be placed in Gammaridae and not in Crangonyctidae. The second amber piece contains two individuals identified as belonging to the still extant genus Synurella and described as S. aliciae sp. nov. 

  4. An Integrated Approach to Understand Relationships Between Shallow Water Benthic Community Structure and Ecosystem Function

    DTIC Science & Technology

    2008-11-01

    Polychaeta Spionidae 0.11 0.11 9 Annelida: Polychaeta Streblospio benedicti 41.11 8.76 9 Arthropoda : Amphipoda Leptocheirus plumulosus 18.67 2.42 9... Arthropoda : Amphipoda Listriella barnardi 0.11 0.11 9 Arthropoda : Cumacea Cyclaspis varians 0.11 0.11 9 Arthropoda : Insecta Chironomidae 0.11 0.11 9... Arthropoda : Isopoda Cyathura polita 2.00 0.47 9 Mollusca: Bivalvia Macoma balthica 3.11 0.81 9 Mollusca: Bivalvia Macoma tenta-mitchelli 0.11 0.11 9 Mollusca

  5. The fauna and rate of degradation of stranded kelp

    NASA Astrophysics Data System (ADS)

    Griffiths, C. L.; Stenton-Dozey, J.

    1981-06-01

    The moisture content, residual dry mass and fauna associated with kelp stranded on a South African beach were monitored for 30 days following its deposition. Plants that were cast up separately dried much more rapidly, but declined in dry mass more slowly, than those deposited in banks. Both types of deposit lost at least half their dry mass within the first 7 days. The fauna colonizing the two types of wrack was similar, a total of 22 species of Coleoptera, three Diptera and two Amphipoda being recorded. Amphipoda and Diptera dominated the early successional stages, but only Coleoptera colonized older, direr wrack. Amphipoda were dramatically more abundant in wrack banks, as compared with single plants. Calculated consumption rates of the fauna were compared with actual declines in kelp mass and showed a good correlation in the case of banked material. Single plants, however, lacked the expected biomass of consumers, probably because Amphipoda, the most important forms, desert single plants by day and migrate below the sand, and are underestimated in a diurnal sampling programme. The role of stranded kelp in enriching the economy of sandy beaches and adjoining marine ecosystems is considered.

  6. THE STATUS OF DIPOREIA SPP. IN LAKE ONTARIO, 1994-1997

    EPA Science Inventory

    Surveys of microinvertebrates conducted in Lake Ontario between 1994 and 1998 revealed a recent decline in Diporeia spp. (Amphipoda) abundance. The lowest population densities and summer biomass are located in the eastern basin of the lake at all depths. Densities and biomass dec...

  7. Transmission of Microsporidian Parasites of Mosquitoes.

    DTIC Science & Technology

    1983-03-01

    aquatic animals, were surveyed (Table 1). These totals exclude Protozoa, Rotatoria, and Nematoda , which were present in most or all of the jars. From the...ROTATORIA + + Al NEMATODA + + AI NEMATOMORPHA 1 2 A ANNELIDA Oliqochaeta 2 9 A ARTHROPODA Crustacea Cladocera 2 + A Copepoda 3 + AI Ostracoda 7 + AI Amphipoda

  8. THE STATUS OF DIPOREIA SPP. IN LAKE ONTARIO, 1994-1997

    EPA Science Inventory

    Surveys of microinvertebrates conducted in Lake Ontario between 1994 and 1998 revealed a recent decline in Diporeia spp. (Amphipoda) abundance. The lowest population densities and summer biomass are located in the eastern basin of the lake at all depths. Densities and biomass dec...

  9. [Crustaceans associated to macroalgae in Bajo Pepito, Isla Mujeres, Mexican Caribbean].

    PubMed

    Campos Vázquez, C

    2000-01-01

    Crustaceans associated with macroalgae were collected for one year by scuba diving in Bajo Pepito, Isla Mujeres, mexican Caribbean. A total of 148 organisms were found: three orders, 11 families, 18 genera and 19 species in nine types of associations. The order with highest abundance was Isopoda (112), followed by Amphipoda (20) and Decapoda (16).

  10. 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.

  11. Preliminary Investigations of Biofouling of Ships’ Hulls: Non-Indigenous Species Investigations in the Columbia River

    DTIC Science & Technology

    2006-04-01

    Cutter Chlorophyta Chlorophyta spp P Cirrepedia Balanus amphitrite P/S Bivalvia Ostreidae sp A P/S Ischadium sp? S Bryozoa Watersipora...Balanus improvisus P/S Hydrozoa Unidentified hydroid B P/S Bryozoa Fredericella indica P Amphipoda Americorophium spp P/S Passenger Chlorophyta...Chlorophyta spp P Tanker Chlorophyta Chlorophyta spp P Cirrepedia Megabalanus sp P Bivalvia Ostreidae sp B P/S Mytilus sp A S Bryozoa

  12. 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

  13. 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. 

  14. Comparing effects of lake- and watershed-scale influences on communities of aquatic invertebrates in shallow lakes.

    PubMed

    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.

  15. Subterranean archipelago in the Australian arid zone: mitochondrial DNA phylogeography of amphipods from central Western Australia.

    PubMed

    Cooper, Steven J B; Bradbury, John H; Saint, Kathleen M; Leys, Remko; Austin, Andrew D; Humphreys, William F

    2007-04-01

    In 1998, a unique subterranean ecosystem was discovered in numerous isolated calcrete (carbonate) aquifers in the arid Yilgarn region of Western Australia. Previous morphological and genetic analyses of a subterranean water beetle fauna suggest that calcrete aquifers are equivalent to closed island habitats that have been isolated for millions of years. We tested this hypothesis further by phylogeographic analyses of subterranean amphipods (Crangonyctoidea: Paramelitidae and Hyalidae) using mitochondrial DNA sequence data derived from the cytochrome oxidase I gene. Phylogenetic analyses and population genetic analyses (samova) provided strong evidence for the existence of at least 16 crangonyctoid and six hyalid divergent mitochondrial lineages, each restricted in their distribution to a single calcrete aquifer, in support of the 'subterranean island (archipelago) hypothesis' and extending its scope to include entirely water respiring invertebrates. Sequence divergence estimates between proximate calcrete populations suggest that calcretes have been isolated at least since the Pliocene, coinciding with a major aridity phase that led to the intermittent drying of surface water. The distribution of calcretes along palaeodrainage channels and on either side of drainage divides, have had less influence on the overall phylogeographic structure of populations, with evidence that ancestral crangonyctoid and hyalid species moved between catchments multiple times prior to their isolation within calcretes. At least two potential modes of evolution may account for the diversity of subterranean amphipod populations: dispersal/vicariance of stygobitic species or colonization of calcretes by surface species and independent evolution of stygobitic characteristics.

  16. Benthic and Sedimentological Studies of the Georgetown Ocean Dredged Material Disposal Site.

    DTIC Science & Technology

    1984-02-01

    12 . Stations . / 10 12 12 *..* 󈧎, .*1*i’ 2 943 2- ~,Palycheeta Gastropoda -;Ascidiacea Isopoda SPelecypoda 7] Bryozoa g chinodormata Mysidacea...3197 1 893 1 6427 1 Polychaeta 3159 1 1031 3 550 2 4740 2 Amphipoda 1490 3 330 5 81 4 1901 3 Bryozoa * 204 11 1198 2 247 3 1649 4 Ascidiacea 255 8 498 4...Cumacea 4 9.5 1 20.5 1 16 4 10 Anthozoa* 3 11 2 11 1 95 3 11 Bryozoa 2 13 3 10 1 16 3 12 Hemichordata* 2 13 1 20.5 1 16 2 13 Scaphapoda 2 13 - - - - 2 14

  17. [Parasitic metazoans of Stenella coeruleoalba (Cetacea: Delphinidae) stranded along the coast of Latium, 1985-1991].

    PubMed

    Cerioni, S; Mariniello, L

    1996-12-01

    The striped dolphin represents the most common species of cetacean stranded along the Italian coasts. A parasitological survey on 17 specimens of Stenella coerulecaiba stranded along coasts of Latium from 1985 to 1991, has been carried out. The morphological study enabled the identification of the following parasites. The sites are reported in brackets. DIGENEA: Campula rochebruni (liver), Campula palliata (liver), Pholeter gastrophilus (pyloric stomach). CESTODA: Tetrabothrium forsteri (intestine), Strobilocephalus triangularis (intestine), Monorygma grimaldii, larvae (abdominal cavity, mesentery, testes), Phyliobothrium delphini, larvae (subcutaneous fat). NEMATODA: Skrjabinalius sp. (lungs). COPEPODA: Pennella sp. (skin). ISOPODA: Ceratothoa parallela (mouth, stomach). AMPHIPODA: Syncyamus aequus (blowhole).

  18. Feeding biology of a guild of benthivorous fishes in a sandy shore on south-eastern Brazilian coast.

    PubMed

    Zahorcsak, P; Silvano, R A; Sazima, I

    2000-08-01

    The feeding biology of eight species of benthivorous fishes was studied in a sandy shore at Anchieta Island, south-eastern Brazilian coast. The fishes fed mainly on Amphipoda and Mysidacea crustaceans. The diet of the most abundant species, the drum Umbrina coroides, was analyzed in three standard length classes (20-55, 56-90 and 91-135 mm). This sciaenid showed an ontogenetic diet shift from Mysidacea to Amphipoda. The feeding behaviour of the sciaenid U. coroides and the gerreid Eucinostomus gula was recorded while snorkeling. During their foraging both species uncovered small organisms buried in the sand. Notwithstanding general similarities in diet, U. coroides and E. gula presented differences in feeding behaviour and morphology. Two carangid species of the genus Trachinotus differed in diet composition and consumed a larger array of food items than the remaining fish species. Differences in diet and feeding activity between the remaining benthivorous species were noted. These differences possibly reduce overlap in resource use and favour the coexistence of guilds of benthivorous fishes on sandy shores.

  19. Energetics of Arctic Zooplankton

    NASA Astrophysics Data System (ADS)

    Callahan, M.; Heintz, R.; Vollenweider, J.; Robertson, A.; Mosher, S.; Pinchuk, A. I.

    2016-02-01

    Zooplankton communities in the arctic may be more sensitive to the effects of climate change than more heavily studied taxa. Large components of the zooplankton communities in the Chukchi and western Beaufort Seas are believed to be advected into the region from centers of production located further south. However, most age-0 fish and many marine mammals rely on zooplankton for sustenance and so changes in the strength of ocean currents could have far reaching trophic effects. For example, changes in the timing of ice retreat influences zooplankton abundance, community structure and nutritional value. We provide baseline energy contents for Euphausiidae Mysidae, Amphipoda and Isopoda collected from coastal waters near Pt. Barrow during the summers of 2014 and 2015. We describe spatial variation in energy content including nearshore versus offshore samples and observations from within Elson Lagoon versus open water. These data inform those interested in connectivity between near and offshore environments and provide a context for understanding ecosystem change.

  20. 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.

  1. 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.

  2. Mass mortality in two common soft-bottom invertebrates, Hydrobia ulvae and Corophium volutator-the possible role of trematodes

    NASA Astrophysics Data System (ADS)

    Jensen, K. T.; Mouritsen, K. N.

    1992-09-01

    Two littoral macrofaunal invertebrates, Hydrobia ulvae (Prosobranchia) and Corophium volutator (Amphipoda) suffered mass mortality on an intertidal mudflat in the Danish Wadden Sea in May June 1990. Dissection of collected H. ulvae individuals revealed a considerable increase from March to May in numbers of infected individuals by microphallid trematodes that use H. ulvae and C. volutator as first and second intermediate host, respectively. The numbers of infested snails were hereafter reduced by an amount equal to the observed mortality rate of snails. At the same time, the C. volutator population became extinct. Since other conceivable mortality factors could be ruled out, parasites are suspected to be the causative agent. Apart from the expected effects on potential predators by the decline in the two invertebrate populations, the benthic community changed and destabilization of the substratum occurred probably because of the die-off in C. volutator. Meteorological data suggest high temperatures as a triggering factor of the massdevelopment of the studied trematodes.

  3. 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.

  4. 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.

  5. Bait-attending fauna of the Kermadec Trench, SW Pacific Ocean: Evidence for an ecotone across the abyssal-hadal transition zone

    NASA Astrophysics Data System (ADS)

    Jamieson, A. J.; Kilgallen, N. M.; Rowden, A. A.; Fujii, T.; Horton, T.; Lörz, A.-N.; Kitazawa, K.; Priede, I. G.

    2011-01-01

    The bait-attending fauna of the abyssal-hadal transition zone of the Kermadec Trench, SW Pacific Ocean (4329-7966 m), was investigated using a baited camera and a trap lander. The abyssal stations (4329-6007 m) revealed a typical scavenging fish community comprising macrourids and synaphobranchid eels, as well as natantian decapods. At the hadal depths of 7199 and 7561 m, the endemic liparid Notoliparis kermadecensis was observed aggregating at the bait reaching surprisingly high numbers of 5 and 13, respectively. A total of 3183 invertebrate samples were collected (mean deployment time=16 h) of which 97.8% were of the order Amphipoda (nine families, 16 species). Ten of the amphipod species represent new distributional records for the Kermadec Trench and the New Zealand Exclusive Economic Zone; this includes the shallowest known record of the endemic hadal amphipod Hirondellea dubia (6000, 6007 m). Using amphipods to statistically examine the compositional change across the abyssal-hadal boundary, an ecotone between depths <6007 and >6890 m was found, indicating that there is an ecologically distinct bait-attending fauna in this trench.

  6. Intersexuality in crustaceans: genetic, individual and population level effects.

    PubMed

    Ford, Alex T; Sambles, Christine; Kille, Peter

    2008-07-01

    Scientists investigating toxicants such as endocrine disrupting chemicals (EDCs) at the cellular at the sub-cellular level are often faced with criticisms as to how these effects can be extrapolated to the level of individuals and their populations. This report aims to provide an overview of the studies undertaken on crustacean model, Echinogammarus marinus LEACH (AMPHIPODA), and intersex phenotypes, at the individual and population levels, and provide additional emergent data at the genomic level. These, normal and intersex, males and females have been investigated by cross-hybridisation microarray analysis and specific sexually dimorphic genes and corresponding properties identified between each sexual phenotype. The morphology, physiology and histology of these intersexes have been investigated in detail and a number of reproductive costs have been identified including reduced fecundity and fertility. These costs have been incorporated into a population model and simulated over a ten-year period to ascertain how different levels of intersexuality affect the stability of populations. Based on the information gained through study of intersex models (with known endocrine dysfunction) together with the substantial quantity of historical data relating to effects of chemicals on amphipod fecundity, growth and mortality, the development of appropriate biomarkers is nearer to being assessed from the level of genes to that of the population.

  7. Potential retention effect at fish farms boosts zooplankton abundance

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

    Coastal aquaculture activities influence wild macrofauna in natural environments due to the introduction of artificial structures, such as floating cages, that provide structural complexity in the pelagic system. This alters the abundance and distribution of the affected species and also their feeding behaviour and diet. Despite this, the effects of coastal aquaculture on zooplankton assemblages and the potential changes in their abundance and distribution remain largely unstudied. Traditional plankton sampling hauls between the farm mooring systems entail some practical difficulties. As an alternative, light traps were deployed at 2 farms in the SW Mediterranean during a whole warm season. Total zooplankton capture by traps at farms was higher than at control locations on every sampling night. It ranged from 3 to 10 times higher for the taxonomic groups: bivalvia, cladocera, cumacea, fish early-life-stages, gastropoda, polychaeta and tanaidacea; 10-20 times higher for amphipoda, chaetognatha, isopoda, mysidacea and ostracoda, and 22 times higher for copepoda and the crustacean juvenile stages zoea and megalopa. Permutational analysis showed significant differences for the most abundant zooplankton groups (copepoda, crustacean larvae, chaetognatha, cladocera, mysidacea and polychaeta). This marked incremental increase in zooplankton taxa at farms was consistent, irrespective of the changing environmental variables registered every night. Reasons for the greater abundance of zooplankton at farms are discussed, although results suggest a retention effect caused by cage structures rather than active attraction through physical or chemical cues.

  8. Thiacloprid affects trophic interaction between gammarids and mayflies.

    PubMed

    Englert, D; Bundschuh, M; Schulz, R

    2012-08-01

    Neonicotinoid insecticides like thiacloprid enter agricultural surface waters, where they may affect predator-prey-interactions, which are of central importance for ecosystems as well as the functions these systems provide. The effects of field relevant thiacloprid concentrations on the leaf consumption of Gammarus fossarum (Amphipoda) were assessed over 96 h (n = 13-17) in conjunction with its predation on Baetis rhodani (Ephemeroptera) nymphs. The predation by Gammarus increased significantly at 0.50-1.00 μg/L. Simultaneously, its leaf consumption decreased with increasing thiacloprid concentration. As a consequence of the increased predation at 1.00 μg/L, gammarids' dry weight rose significantly by 15% compared to the control. At 4.00 μg/L, the reduced leaf consumption was not compensated by an increase in predation causing a significantly reduced dry weight of Gammarus (∼20%). These results may finally suggest that thiacloprid adversely affects trophic interactions, potentially translating into alterations in ecosystem functions, like leaf litter breakdown and aquatic-terrestrial subsidies.

  9. 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

  10. 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

  11. Non-reliance of metazoans on stromatolite-forming microbial mats as a food resource.

    PubMed

    Rishworth, Gavin M; Perissinotto, Renzo; Bird, Matthew S; Strydom, Nadine A; Peer, Nasreen; Miranda, Nelson A F; Raw, Jacqueline L

    2017-02-16

    Grazing and burrowing organisms usually homogenise microalgal mats that form on benthic sediments of many aquatic ecosystems. In the absence of this disruption, microalgal mats can accrete laminated deposits (stromatolites). Stromatolites are rare in modern coastal ecosystems, but persist at locations where metazoans are largely excluded. This study aimed to assess the trophic structure at stromatolite locations where metazoans co-occur, to determine the grazing influence exerted by the metazoans on the stromatolite-forming microalgae (cyanobacteria and diatoms). Stable isotope signatures (δ(13)C and δ(15)N) were used as food-web tracers and dietary composition of consumers was calculated using source mixing models. Results clearly demonstrate that the dominant macrofaunal grazers do not utilise stromatolite material as a food resource, but rather subsist on autochthonous macroalgae. For instance, the mean (±SD) dietary composition of two of the most abundant grazers, Melita zeylanica (Amphipoda) and Composetia cf. keiskama (Polychaeta), consisted of 80 ± 11% and 91 ± 7% macroalgae, respectively. This suggests that the stromatolite-forming benthic microalgae are not disrupted significantly by grazing pressures, allowing for the layered mineralisation process to perpetuate. Additionally, grazers likely have a restrictive influence on pool macroalgae, maintaining the competitive balance between micro- and macroalgal groups.

  12. 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.

  13. Submarine groundwater discharges create unique benthic communities in a coastal sandy marine environment

    NASA Astrophysics Data System (ADS)

    Leitão, Francisco; Encarnação, João; Range, Pedro; Schmelz, Rüdiger M.; Teodósio, Maria A.; Chícharo, Luís

    2015-09-01

    In this study we assessed the small-scale effects of submarine groundwater discharges (SGD) on macrofaunal assemblages associated with shallow sandy sediments along the south coast of Portugal. Corer samples were collected in a (1) subtidal seep, (2) at the edge of the seep (periphery) and (3) in the surrounding area. Community structure varied across areas, with diversity, species richness and evenness generally low at seep relatively to the surrounding area. Community composition within the seep was reduced to a small number of taxa, although total abundance was similar between seeps and surrounding areas. The seep was characterized by a distinct hydrological environment, with lower salinity and pH, relative to the surroundings sandy areas. More than 93% of the benthic macrofauna in the seep was dominated by Lumbricillus lineatus (enchytraeid oligochaetes). This study is the first to record the presence of this euryaline species in Portuguese marine waters. In the surrounding area Spionidae Polychaetes and Bathyporeia sp. (Amphipoda) were the most frequent and abundant taxa. These findings provide evidence for a direct association between SGD effect and the composition of benthic marine assemblages. The patchy habitat created by groundwater seep allowed euryhaline species with short and fast recruitment times to occur in a fully marine environment. Whether this pattern is consistent, or only occurs when smooth favorable sea conditions are not superimposed on the groundwater effect remains uncertain.

  14. Non-reliance of metazoans on stromatolite-forming microbial mats as a food resource

    PubMed Central

    Rishworth, Gavin M.; Perissinotto, Renzo; Bird, Matthew S.; Strydom, Nadine A.; Peer, Nasreen; Miranda, Nelson A. F.; Raw, Jacqueline L.

    2017-01-01

    Grazing and burrowing organisms usually homogenise microalgal mats that form on benthic sediments of many aquatic ecosystems. In the absence of this disruption, microalgal mats can accrete laminated deposits (stromatolites). Stromatolites are rare in modern coastal ecosystems, but persist at locations where metazoans are largely excluded. This study aimed to assess the trophic structure at stromatolite locations where metazoans co-occur, to determine the grazing influence exerted by the metazoans on the stromatolite-forming microalgae (cyanobacteria and diatoms). Stable isotope signatures (δ13C and δ15N) were used as food-web tracers and dietary composition of consumers was calculated using source mixing models. Results clearly demonstrate that the dominant macrofaunal grazers do not utilise stromatolite material as a food resource, but rather subsist on autochthonous macroalgae. For instance, the mean (±SD) dietary composition of two of the most abundant grazers, Melita zeylanica (Amphipoda) and Composetia cf. keiskama (Polychaeta), consisted of 80 ± 11% and 91 ± 7% macroalgae, respectively. This suggests that the stromatolite-forming benthic microalgae are not disrupted significantly by grazing pressures, allowing for the layered mineralisation process to perpetuate. Additionally, grazers likely have a restrictive influence on pool macroalgae, maintaining the competitive balance between micro- and macroalgal groups. PMID:28205600

  15. 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.

  16. Do distantly related parasites rely on the same proximate factors to alter the behaviour of their hosts?

    PubMed Central

    Ponton, F; Lefevre, T; Lebarbenchon, C; Thomas, F; Loxdale, H.D; Marché, L; Renault, L; Perrot-Minnot, M.J; Biron, D.G

    2006-01-01

    Phylogenetically unrelated parasites often increase the chances of their transmission by inducing similar phenotypic changes in their hosts. However, it is not known whether these convergent strategies rely on the same biochemical precursors. In this paper, we explored such aspects by studying two gammarid species (Gammarus insensibilis and Gammarus pulex; Crustacea: Amphipoda: Gammaridae) serving as intermediate hosts in the life cycle of two distantly related parasites: the trematode, Microphallus papillorobustus and the acanthocephalan, Polymorphus minutus. Both these parasite species are known to manipulate the behaviour of their amphipod hosts, bringing them towards the water surface, where they are preferentially eaten by aquatic birds (definitive hosts). By studying and comparing the brains of infected G. insensibilis and G. pulex with proteomics tools, we have elucidated some of the proximate causes involved in the parasite-induced alterations of host behaviour for each system. Protein identifications suggest that altered physiological compartments in hosts can be similar (e.g. immunoneural connexions) or different (e.g. vision process), and hence specific to the host–parasite association considered. Moreover, proteins required to alter the same physiological compartment can be specific or conversely common in both systems, illustrating in the latter case a molecular convergence in the proximate mechanisms of manipulation. PMID:17015311

  17. 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.

  18. 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.

  19. 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.

  20. Observations of wing-feather molt and summer feeding ecology of Steller's Eiders at Nelson Lagoon, Alaska

    USGS Publications Warehouse

    Petersen, Margaret R.

    1980-01-01

    The population size, moult chronology, food habits, and feeding behaviour of Steller's Eiders Polysticta stelleri were studied at Nelson Lagoon, Alaska from May to October 1977. Sub-adults were flightless from late July to late August and the adult males were flightless from late August to mid September. Adult females were rarely flightless at Nelson Lagoon but commonly flightless at Izembek Bay. Steller's Eiders ate primarily bivalve mollusca and amphipod crustacea, with Mytilus edulis and Anisogammarus pugettensis the most important foods. Eiders took amphipoda prior to the wing-feather moult, bivalves during the wing-feather moult, and both types of invertebrates after the wing-feather moult. Steller's Eiders fed primarily at the low tide by diving (flock-feeding) or head-dipping, both during the day and at night. There was no difference in feeding behaviour between ages or sexes. Eiders fed almost exclusively by diving after the wing-feather moult and apparently fed more as the season progressed.

  1. 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

  2. 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.

  3. 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.

  4. Benthic Crustacea from tropical and temperate reef locations: differences in assemblages and their relationship with habitat structure

    NASA Astrophysics Data System (ADS)

    Kramer, Michael J.; Bellwood, David R.; Taylor, Richard B.; Bellwood, Orpha

    2017-09-01

    Tropical and temperate marine habitats have long been recognised as fundamentally different system, yet comparative studies are rare, particularly for small organisms such as Crustacea. This study investigates the ecological attributes (abundance, biomass and estimated productivity) of benthic Crustacea in selected microhabitats from a tropical and a temperate location, revealing marked differences in the crustacean assemblages. In general, microhabitats from the tropical location (dead coral, the epilithic algal matrix [algal turfs] and sand) supported high abundances of small individuals (mean length = 0.53 mm vs. 0.96 mm in temperate microhabitats), while temperate microhabitats (the brown seaweed Carpophyllum sp., coralline turf and sand) had substantially greater biomasses of crustaceans and higher estimated productivity rates. In both locations, the most important microhabitats for crustaceans (per unit area) were complex structures: tropical dead coral and temperate Carpophyllum sp. It appears that the differences between microhabitats are largely driven by the size and relative abundance of key crustacean groups. Temperate microhabitats have a higher proportion of relatively large Peracarida (Amphipoda and Isopoda), whereas tropical microhabitats are dominated by small detrital- and microalgal-feeding crustaceans (harpacticoid copepods and ostracods). These differences highlight the vulnerability of tropical and temperate systems to the loss of complex benthic structures and their associated crustacean assemblages.

  5. 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.

  6. 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

  7. Sediment-quality assessment of the Lower Oconee River

    USGS Publications Warehouse

    Lasier, P.J.; Winger, P.V.; Shelton, J.L.; 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.

  8. Atypical feeding behavior of Long-tailed Ducks in the wake of a commercial fishing boat while clamming

    USGS Publications Warehouse

    Perry, Matthew; Osenton, Peter C.; White, Timothy P.

    2017-01-01

    A foraging group of Clangula hyemalis (Long-tailed Duck) was observed on 10 February 2010 diving behind a commercial boat that was clamming near Monomoy Island, Nantucket Sound, MA. We used a shotgun to collect 9 of the ducks, and our analyses of gizzard and gullet (esophagus and proventriculus) revealed 37 food items in the gizzard and 16 in the gullet. Mollusca were the dominant food in the gizzard (49%), whereas Crustacea were dominant in the gullet (57%). Crustacea were the second most important food in the gizzard (38%), whereas Mollusca were the second most important food in the gullet (31%). Relatively high volumes of the Amphipoda Caprella sp. (skeleton shrimp) and the Decopoda Crangon septemspinosa (Sand Shrimp) were recorded in the gullet and gizzard. Ensis directus (Atlantic Jackknife Clam) formed the greatest volume of Mollusca in the gizzard (15%) and in the gullet (15%). Long-tailed Ducks had fed on this Bivalvia and several other species of Mollusca that had no shell or broken shell when consumed. Many of the food organisms were apparently dislodged and some damaged by the clamming operation creating an opportunistic feeding strategy for the Long-tailed Ducks.

  9. 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

    2012-11-06

    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.

  10. Impacts of golf courses on macroinvertebrate community structure in Precambrian shield streams.

    PubMed

    Winter, Jennifer G; Somers, Keith M; Dillon, Peter J; Paterson, Carolyn; Reid, Ron A

    2002-01-01

    The influence of golf course operation on benthic macroinvertebrate communities in Precambrian Shield streams was evaluated using rapid bioassessment and the reference condition approach. Streams were sampled for water chemistry and invertebrates in 1999 and 2000, six on operational golf courses, and seven in forested reference locations. Correspondence analysis (CA) was used to determine the major patterns in the macroinvertebrate taxa, and canonical correspondence analysis (CCA) was used to evaluate relationships with environmental variables. The reference streams were used to define the normal range of variation for a variety of summary indices to evaluate the golf course streams. In all cases, golf course streams were higher in nutrients and dissolved ions and more alkaline than the forested reference streams. There was considerable variability in the macroinvertebrate fauna from the golf course streams, which was related to differences in golf course land management practices and to the potential influence of highway runoff. Of the management practices evaluated, fertilizer application rates in particular were important, as was the presence of ponds upstream on the course. Invertebrate taxa with higher abundances in golf course streams included Turbellaria, Isopoda, Amphipoda, Zygoptera, and Trombidiformes. Taxa more common in the reference streams included Ephemeroptera, Megaloptera, Culicidae, and Plecoptera. There were marked differences in the overall benthic macroinvertebrate community in three of the six golf course streams studied relative to the forested reference streams, suggesting that golf course land management on the Precambrian Shield can be associated with significant differences in macroinvertebrate community structure.

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

    PubMed Central

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

    2016-01-01

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

  12. Morphology of the haemolymph vascular system in Tanaidacea and Cumacea: - implications for the relationships of "core group" Peracarida (Malacostraca; Crustacea).

    PubMed

    Wirkner, Christian S; Richter, Stefan

    2008-03-01

    Tanaidacea and Cumacea are crucial for understanding the phylogenetic relationships of "core group" peracarids. Here, the haemolymph vascular system in three tanaidacean and four cumacean species was studied on the basis of histological sections and 3D reconstruction. The circulatory organs in Tanaidacea include a tubular heart which extends through most of the thorax. It is extended into the cephalothorax by an anterior aorta. Haemolymph enters the heart through one to two pairs of incurrent ostia. Up to five pairs of cardiac arteries emanate from the heart to supply viscera in the body cavity. In the anterior cephalothorax, the aorta forms a pericerebral ring from which the arteries for the brain and the antennae branch off. In Cumacea, the heart is shorter but more voluminous. In all cumaceans studied, five pairs of cardiac arteries supply the thoracopods and the pleon. The single pair of ostia is situated in the centre of the heart. The anterior aorta runs into the anterior cephalothorax where it supplies the brain and antennae. This paper provides a general comparative discussion of all available data from the literature and the data provided herein. In certain details, the haemolymph vascular system of the Tanaidacea resembles that of Amphipoda, and some correspondences between Cumacea and Isopoda are pointed out. These findings might support a closer relationship between the latter two taxa while they show no support for an amphipod/isopod clade.

  13. 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.

  14. 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.

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

    PubMed

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

    2016-01-01

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

  16. 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  18. Effect of Acanthocephala infection on the reproductive potential of crustacean intermediate hosts.

    PubMed

    Dezfuli, B S; Lui, A; Giovinazzo, G; Giari, L

    2008-05-01

    The effect of a naturally acquired infection by three acanthocephalan parasites Dentitruncus truttae, Echinorhynchus truttae, and Polymorphus minutus on the reproductive potential of their intermediate host, Echinogammarus tibaldii (Amphipoda) from Lake Piediluco (Centre of Italy) was assessed. During May 2007, 1135 amphipods were collected from two different samplings and examined for larval helminths. Forty-five amphipods were infected and of those, 16 were infected with D. truttae (intensity=1-3 larvae), 15 with E. truttae (intensity=1-2 larvae), and 14 with P. minutus (intensity=1 larva). The sex ratio was nearly 1:1 in all examined amphipods. One female infected with D. truttae contained six eggs in the brood pouch and another female infected with E. truttae contained five eggs. However, none of the eight female amphipods harbouring P. minutus larva contained eggs in their brood pouch. Uninfected females of the same size and body length as that of the infected females contained between 20 and 32 eggs. No acanthocephalan species were found to co-occur.

  19. Trophic interaction of invertebrate zooplankton on either side of the Charlie Gibbs Fracture Zone/Subpolar Front of the Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Letessier, T. B.; Pond, David W.; McGill, Rona A. R.; Reid, William D. K.; Brierley, Andrew S.

    2012-06-01

    Trophic relationships and vertical distribution patterns of dominant mesozooplankton (2-20 mm) and macrozooplankton (> 20 mm) invertebrates (Euphausiacea, Copepoda, Decapoda, Amphipoda, Thecosomata and Lophogastrida) were investigated within the epi- and meso-pelagic zone (0-200 and 200-800 m depth), north (54° N) and south (49° N) of the Subpolar Front (SPF) on the Mid-Atlantic Ridge (MAR). Dietary relationships were explored using stable isotope ratios of nitrogen and carbon, and fatty acid trophic markers (FATM). Individuals from the southern stations (~ 49° N) had higher concentrations of the dinoflagellate FATM (22:6(n-3)), and individuals from northern stations had higher concentration in Calanus sp. and storage FATMs (20:1(n-9) and 22:1(n-9)). Energy pathways on either side of the SPF showed retention of δ13C differences (as measured in POM) in bathypelagic species. Observations of FATM levels and abundance patterns are consistent with present theories pertaining to primary production patterns at the base of the food chain, which states that the peak of the production is higher in the northern sector than in the south.

  20. 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.

  1. 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.

  2. Selective feeding by shredders on leaf-colonizing stream fungi: comparison of macroinvertebrate taxa.

    PubMed

    Arsuffi, T L; Suberkropp, K

    1989-04-01

    Laboratory experiments were conducted to examine the effects of fungal species composition of leaf detritus on the feeding of distantly related macroinvertebrate shredders. Preferences of shredders representing three orders of insects (Diptera: Tipulidae; Plecoptera: Pteronarcidae; Trichoptera: Limnephilidae and Calamatoceridae) and one each of gastropods (Basommatophora: Planorbidae) and crustaceans (Amphipoda: Gammaridae) were compared. Shredder preferences were based on consumption of leaves separately colonized by one of eight species of aquatic hyphomycetes. The feeding patterns of the invertebrates ranged from lack of feeding to heavy consumption of fungal-colonized leaves. Where consumption occurred, rank orders of preference and degree of selectivity differed among invertebrate shredders. Differences in preferences together with relationships between degree of selectivity and the relative mobility and digestive specializations exhibited by shredders suggest that the exploitation of fungal-colonized leaf detritus by different taxa is affected by phylogenetic constraints. Our results suggest that fungal species composition affects the feeding of a variety of shredders and that fungal species composition may be as important as degree of conditioning in determining food selection by shredders.

  3. 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.

  4. 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.

  5. 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.

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

    PubMed

    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.

  7. 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.

  8. Allergenicity and allergens of amphipods found in nori (dried laver).

    PubMed

    Motoyama, Kanna; Hamada, Yuki; Nagashima, Yuji; Shiomi, Kazuo

    2007-09-01

    Gammaridean and caprellid amphipods, crustaceans of the order Amphipoda, inhabit laver culture platforms and, hence, are occasionally found in nori (dried laver) sheets. Amphipods mixed in nori may cause allergic reactions in sensitized patients, as is the case with other crustaceans, such as shrimp and crab, members of the order Decapoda. In this study, dried samples of amphipods (unidentified) found in nori and fresh samples of gammaridean amphipod (Gammarus sp., not accurately identified) and caprellid amphipod (Caprella equilibra) were examined for allergenicity and allergens using two species of decapods (black tiger prawn and spiny lobster) as references. When analyzed by ELISA, sera from crustacean-allergic patients reacted to extracts from amphipod samples, although less potently than to the extracts from decapods. In IgE-immunoblotting, a 37-kDa protein was found to be the major allergen in amphipods. Based on the molecular mass and the cross-reactivity with decapod tropomyosin evidenced by inhibition ELISA and inhibition immunoblotting, the 37-kDa protein was identified as amphipod tropomyosin.

  9. 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.

  10. 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.

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

    PubMed

    Brugni, Norma L; Viozzi, Gustavo P

    2010-02-01

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

  12. Reduced metals concentrations of water, sediment and hyalella azteca from lakes in the vicinity of the sudbury metal smelters, Ontario, Canada.

    PubMed

    Shuhaimi-Othman, M; Pascoe, D; Borgmann, U; Norwood, W P

    2006-06-01

    Hyalella azteca (Crustacea: Amphipoda), water and sediments from 12 circum-neutral lakes between Sudbury and North Bay in Ontario, Canada were sampled in August 1998 and analyzed for 10 metals including Cu, Zn, Cd, Ni, Pb, Co, Mo, V, Ba and Ti. Statistical analyses showed that concentrations of the metals in H. azteca, water and sediment differed significantly (ANOVA, P<0.05) among lakes (except for Zn and Pb in H. azteca and Mo in water). There was a trend of declining metal concentration, especially for Cu, Ni and Co (in water, Hyalella and sediment), with distance from the smelters indicating the reduced impact of atmospheric pollution. Metal concentrations of lakes (water) in the Sudbury area were found to be lower compared to data from the 1970s and 1980s indicating an improvement in water quality. Metal concentrations in field-collected amphipods compared favorably with those measured in the laboratory in animals exposed to deep-water sediments, provided metal concentrations were not extremely low (e.g., Pb) and that water chemistry differences (e.g., pH) were taken into account for some metals (especially Cd). In general bioaccumulation of metals in H. azteca was predicted better from surface water than from sediment total metal.

  13. 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.

  14. 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

  15. 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.

  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. 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.

  18. 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

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

    PubMed

    Hirst, Andrew G; Forster, Jack

    2013-10-07

    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.

  20. 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

  1. Influence of Benthic Macrofauna as a Spatial Structuring Agent for Juvenile Haddock (Melanogrammus aeglefinus) on the Eastern Scotian Shelf, Atlantic Canada

    PubMed Central

    2016-01-01

    We examined the habitat of juvenile haddock on the eastern Scotian Shelf (off Nova Scotia, Canada) in relation to grab-sampled benthic macrofaunal invertebrate species assemblages in order to determine whether there were significant differences in benthic macrofauna between areas of historically persistent high and low juvenile haddock abundance. Our analyses were conducted over two spatial scales in each of two years: among banks (Emerald, Western and Sable Island), approximately 60 km distant from each other, and between areas of high and low juvenile haddock abundance at distances of 10 to 30 km–all in an area that had not experienced groundfishing in the decade prior to sampling. We also examined fine-scale (10s of metres) within-site variability in the macrofauna and used surficial sediment characteristics, along with hydrographic variables, to identify environmental correlates. PERMANOVA identified statistically significant differences in biomass, density and composition of the benthos associated with juvenile haddock abundance; however it was difficult to determine whether the results had biological relevance. Post hoc tests showed that these differences occurred only on Sable Island Bank where both fish and benthos may have been independently responding to sediment type which was most different there (100% sand in the area of low haddock abundance vs. 22% gravel in the area of high haddock abundance). In total, 383 benthic taxa representing 13 phyla were identified. Annelida was the most specious phylum (36.29% of taxa, representing 33 families), followed by Arthropoda (with Crustaceans, mostly Amphipoda, accounting for 25.07% of the total number of taxa). The strongest pattern in the macrofauna was expressed at the largest scale, between banks, accounting for approximately 25% of the variation in the data. Emerald Bank, deeper, warmer and saltier than the Western and Sable Island Banks, had a distinctive fauna. PMID:27649419

  2. 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

  3. 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

  4. 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.

  5. 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

  6. [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.

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

    PubMed

    Bauzà-Ribot, Maria M; Jaume, Damià; Fornós, Joan J; Juan, Carlos; Pons, Joan

    2011-07-26

    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. 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. 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.

  8. Molecular characterisation of the Microsporidia of the amphipod Gammarus duebeni across its natural range revealed hidden diversity, wide-ranging prevalence and potential for co-evolution.

    PubMed

    Krebes, L; Blank, M; Frankowski, J; Bastrop, R

    2010-10-01

    Microsporidia comprise an unusual group of intracellular, eukaryotic parasites that exhibit ubiquitous distribution throughout the animal kingdom. We analysed the small subunit ribosomal gene (SSUrDNA) using PCR and sequencing and screened 894 Gammarus duebeni (Crustacea, Amphipoda) specimens from 35 European marine and freshwater populations. We discovered considerable hidden microsporidian diversity. Blast searches, sequence analysis and phylogenetic analysis revealed intraspecific sequence variants of known species Dictyocoela duebenum,Dictyocoela muelleri, Pleistophora mulleri and Nosema granulosis. For seven SSUrDNA sequences, we did not find corresponding GenBank entries; they likely represent new species, provisionally classified within the genus Microsporidium. Phylogenetic reconstructions revealed their position as polyphyletic, thereby lending support to the hypothesis of an early microsporidian radiation within this host group. Nevertheless, four of the presumptive novel species formed a discrete and well-supported subclade in the phylogenetic analysis. The respective host specimens were collected from disjunct freshwater sites in Wales, Ireland and Brittany (France) and may represent a new, G. duebeni-specific, microsporidian genus. At the population level, our screening showed that parasitism through Microsporidia is the rule rather than the exception in G. duebeni. We found Microsporidia in 91% of sampled G. duebeni populations. This finding may have considerable consequences for the interpretation of results from ecological, behavioural, physiological and evolutionary studies of the host, as parasitism can significantly influence these traits. Because the host G. duebeni has a complex phylogeography and evolutionary history, the studied host-parasite system may have potential as a model system for investigating processes of co-evolution. Copyright 2010 Elsevier B.V. All rights reserved.

  9. Influence of Benthic Macrofauna as a Spatial Structuring Agent for Juvenile Haddock (Melanogrammus aeglefinus) on the Eastern Scotian Shelf, Atlantic Canada.

    PubMed

    Rincón, Beatriz; Kenchington, Ellen L

    2016-01-01

    We examined the habitat of juvenile haddock on the eastern Scotian Shelf (off Nova Scotia, Canada) in relation to grab-sampled benthic macrofaunal invertebrate species assemblages in order to determine whether there were significant differences in benthic macrofauna between areas of historically persistent high and low juvenile haddock abundance. Our analyses were conducted over two spatial scales in each of two years: among banks (Emerald, Western and Sable Island), approximately 60 km distant from each other, and between areas of high and low juvenile haddock abundance at distances of 10 to 30 km-all in an area that had not experienced groundfishing in the decade prior to sampling. We also examined fine-scale (10s of metres) within-site variability in the macrofauna and used surficial sediment characteristics, along with hydrographic variables, to identify environmental correlates. PERMANOVA identified statistically significant differences in biomass, density and composition of the benthos associated with juvenile haddock abundance; however it was difficult to determine whether the results had biological relevance. Post hoc tests showed that these differences occurred only on Sable Island Bank where both fish and benthos may have been independently responding to sediment type which was most different there (100% sand in the area of low haddock abundance vs. 22% gravel in the area of high haddock abundance). In total, 383 benthic taxa representing 13 phyla were identified. Annelida was the most specious phylum (36.29% of taxa, representing 33 families), followed by Arthropoda (with Crustaceans, mostly Amphipoda, accounting for 25.07% of the total number of taxa). The strongest pattern in the macrofauna was expressed at the largest scale, between banks, accounting for approximately 25% of the variation in the data. Emerald Bank, deeper, warmer and saltier than the Western and Sable Island Banks, had a distinctive fauna.

  10. 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

  11. Myogenesis of Malacostraca – the “egg-nauplius” concept revisited

    PubMed Central

    2013-01-01

    Background Malacostracan evolutionary history has seen multiple transformations of ontogenetic mode. For example direct development in connection with extensive brood care and development involving planktotrophic nauplius larvae, as well as intermediate forms are found throughout this taxon. This makes the Malacostraca a promising group for study of evolutionary morphological diversification and the role of heterochrony therein. One candidate heterochronic phenomenon is represented by the concept of the ‘egg-nauplius’, in which the nauplius larva, considered plesiomorphic to all Crustacea, is recapitulated as an embryonic stage. Results Here we present a comparative investigation of embryonic muscle differentiation in four representatives of Malacostraca: Gonodactylaceus falcatus (Stomatopoda), Neocaridina heteropoda (Decapoda), Neomysis integer (Mysida) and Parhyale hawaiensis (Amphipoda). We describe the patterns of muscle precursors in different embryonic stages to reconstruct the sequence of muscle development, until hatching of the larva or juvenile. Comparison of the developmental sequences between species reveals extensive heterochronic and heteromorphic variation. Clear anticipation of muscle differentiation in the nauplius segments, but also early formation of longitudinal trunk musculature independently of the teloblastic proliferation zone, are found to be characteristic to stomatopods and decapods, all of which share an egg-nauplius stage. Conclusions Our study provides a strong indication that the concept of nauplius recapitulation in Malacostraca is incomplete, because sequences of muscle tissue differentiation deviate from the chronological patterns observed in the ectoderm, on which the egg-nauplius is based. However, comparison of myogenic sequences between taxa supports the hypothesis of a zoea-like larva that was present in the last common ancestor of Eumalacostraca (Malacostraca without Leptostraca). We argue that much of the developmental

  12. 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

  13. Environmental domains and range-limiting mechanisms: testing the Abundant Centre Hypothesis using southern African sandhoppers.

    PubMed

    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. Food and feeding habits of juvenile flounder Platichthys flesus (L.), abd turbot Scophthalmus maximus L. in the åland archipelago, northern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Aarnio, Katri; Bonsdorff, Erik; Rosenback, Nina

    1996-12-01

    The food choice of juvenile flounder ( Platichthys flesus) and turbot ( Scophthalmus maximus) was studied in the northern Baltic Sea during the years 1988, 1989, 1994 and 1995. The diet included organisms from 30 species/taxa in flounder (n = 306) and 10 species/taxa in turbot (n = 41). Flounder ⩽ 45 mm mainly consumed meiofauna (dominating taxon: Harpacticoida, Copepoda) and larger fish (46-101 mm) consumed macrofauna (dominating taxa: Oligochaeta, Amphipoda and Chironomidae). In terms of biomass, macrofauna dominated for all sizes of flounders, and meiofauna was important only for the smallest fish. A strong seasonal variation could be detected in the diet. In spring, macrofauna dominated for all size classes of fish (only fish > 30 mm were caught in spring), while in summer and autumn meiofauna dominated the diets for fish ⩽ 45 mm in size. Juvenile turbot (22-88 mm) consumed macrofauna and small fish. Turbot ⩽ 30 mm consumed mainly amphipods, while > 30 mm turbot consumed mysid shrimps, amphipods and fish. The ontogenetic shift from meio- to macrofauna-sized prey in flounders occurs at a larger fish size in the northern Baltic Sea than reported in other areas, possibly depending on the increased relative importance of meiofauna in the northern Baltic. The seasonal variation in the diet could be due to seasonally changing abundances in the zoobenthos, or for the small fish (1-group, spring), to switching from meio- to macrofauna in order to optimize their energy gain. The 0-group flounders consumed meiofauna for a long period, possibly due to a learning-process or simply due to easy availability of meiofauna. Turbot has a much larger mouth gap than flounders, thus allowing them to consume macrofauna from the beginning of their benthic life.

  15. 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

  16. 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.

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

    PubMed

    Raupach, Michael J; Barco, Andrea; Steinke, Dirk; Beermann, Jan; Laakmann, Silke; Mohrbeck, Inga; Neumann, Hermann; Kihara, Terue C; Pointner, Karin; Radulovici, Adriana; Segelken-Voigt, Alexandra; Wesse, Christina; Knebelsberger, Thomas

    2015-01-01

    During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for 198 (96.6%) of the analyzed species. Six species were characterized by two BINs (2.9%), and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%). Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%). Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761), underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequences.

  18. Phylogenomic analysis of Copepoda (Arthropoda, Crustacea) reveals unexpected similarities with earlier proposed morphological phylogenies.

    PubMed

    Eyun, Seong-Il

    2017-01-19

    Copepods play a critical role in marine ecosystems but have been poorly investigated in phylogenetic studies. Morphological evidence supports the monophyly of copepods, whereas interordinal relationships continue to be debated. In particular, the phylogenetic position of the order Harpacticoida is still ambiguous and inconsistent among studies. Until now, a small number of molecular studies have been done using only a limited number or even partial genes and thus there is so far no consensus at the order-level. This study attempted to resolve phylogenetic relationships among and within four major copepod orders including Harpacticoida and the phylogenetic position of Copepoda among five other crustacean groups (Anostraca, Cladocera, Sessilia, Amphipoda, and Decapoda) using 24 nuclear protein-coding genes. Phylogenomics has confirmed the monophyly of Copepoda and Podoplea. However, this study reveals surprising differences with the majority of the copepod phylogenies and unexpected similarities with postembryonic characters and earlier proposed morphological phylogenies; More precisely, Cyclopoida is more closely related to Siphonostomatoida than to Harpacticoida which is likely the most basally-branching group of Podoplea. Divergence time estimation suggests that the origin of Harpacticoida can be traced back to the Devonian, corresponding well with recently discovered fossil evidence. Copepoda has a close affinity to the clade of Malacostraca and Thecostraca but not to Branchiopoda. This result supports the hypothesis of the newly proposed clades, Communostraca, Multicrustacea, and Allotriocarida but further challenges the validity of Hexanauplia and Vericrustacea. The first phylogenomic study of Copepoda provides new insights into taxonomic relationships and represents a valuable resource that improves our understanding of copepod evolution and their wide range of ecological adaptations.

  19. 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.

  20. Ocean acidification alters zooplankton communities and increases top-down pressure of a cubozoan predator.

    PubMed

    Hammill, Edd; Johnson, Ellery; Atwood, Trisha B; Harianto, Januar; Hinchliffe, Charles; Calosi, Piero; Byrne, Maria

    2017-08-29

    The composition of local ecological communities is determined by the members of the regional community that are able to survive the abiotic and biotic conditions of a local ecosystem. Anthropogenic activities since the industrial revolution have increased atmospheric CO2 concentrations, which have in turn decreased ocean pH and altered carbonate ion concentrations: so called ocean acidification (OA). Single-species experiments have shown how OA can dramatically affect zooplankton development, physiology and skeletal mineralization status, potentially reducing their defensive function and altering their predatory and antipredatory behaviors. This means that increased OA may indirectly alter the biotic conditions by modifying trophic interactions. We investigated how OA affects the impact of a cubozoan predator on their zooplankton prey, predominantly Copepoda, Pleocyemata, Dendrobranchiata, and Amphipoda. Experimental conditions were set at either current (pCO2 370 μatm) or end-of-the-century OA (pCO2 1,100 μatm) scenarios, crossed in an orthogonal experimental design with the presence/absence of the cubozoan predator Carybdea rastoni. The combined effects of exposure to OA and predation by C. rastoni caused greater shifts in community structure, and greater reductions in the abundance of key taxa than would be predicted from combining the effect of each stressor in isolation. Specifically, we show that in the combined presence of OA and a cubozoan predator, populations of the most abundant member of the zooplankton community (calanoid copepods) were reduced 27% more than it would be predicted based on the effects of these stressors in isolation, suggesting that OA increases the susceptibility of plankton to predation. Our results indicate that the ecological consequences of OA may be greater than predicted from single-species experiments, and highlight the need to understand future marine global change from a community perspective. © 2017 John Wiley & Sons

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

    PubMed

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

    2011-07-01

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

  2. 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.

  3. 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.

  4. 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

  5. Diets and standing stocks of benthopelagic fishes at two bathymetrically different midoceanic localities in the northeast Atlantic

    NASA Astrophysics Data System (ADS)

    Martin, Bettina; Christiansen, Bernd

    1997-04-01

    Deep-sea benthopelagic fishes were sampled by trawl and free-fall longline at two latitudinally and bathymetrically separated stations in the northeastern Atlantic. The catch structure and the contents of the fish stomachs were analysed. The northern, 3000 m deep station in the Iceland Basin exceeded the deeper (4500 m) site in terms of demersal fish biomass and abundance by factors of 5 and 10, respectively. Synaphobranchidae of the species Histiobranchus bathybius and several species of Macrouridae contributed to the samples, the latter dominating with Coryphaenoides (Nematonurus) armatus most abundant in the north and with Coryphaenoides (Chalinura) leptolepis in the south. Diet composition was studied for numerical abundance and wet weight of prey organisms. In the Iceland Basin, where two size classes of C. (N.) armatuscould be analysed separately, an ontogenetic change in diet was noted. Individuals shorter than 30 cm in length fed mainly on benthic and epibenthic Crustacea whereas the larger specimens showed a high proportion of fish and Cephalopoda in their stomachs. At the southern site (BIOTRANS station in the West European Basin) Amphipoda, fish and Cephalopoda were the main food source. Coryphaenoides (Chalinura) leptolepisfed on Malacostraca and fish at the northern site, but on Polychaeta and Cephalopoda at the southern station. Stomachs of H. bathybius contained food only in the Iceland Basin. Their diet consisted mainly of Malacostraca and Cephalopoda. Despite their state of digestion, most Cephalopoda could be identified by means of their beaks, which also allowed a recalculation of their original size. The taxonomic composition and the size structure led to the assumption that most Cephalopoda were epi- or mesopelagic and had been preyed upon near the bottom as carcasses. The possible trophic position of the predominant benthopelagic fishes in the benthic boundary layer is discussed.

  6. Eumalacostracan phylogeny and total evidence: limitations of the usual suspects

    PubMed Central

    Jenner, Ronald A; Dhubhghaill, Ciara Ní; Ferla, Matteo P; Wills, Matthew A

    2009-01-01

    Background The phylogeny of Eumalacostraca (Crustacea) remains elusive, despite over a century of interest. Recent morphological and molecular phylogenies appear highly incongruent, but this has not been assessed quantitatively. Moreover, 18S rRNA trees show striking branch length differences between species, accompanied by a conspicuous clustering of taxa with similar branch lengths. Surprisingly, previous research found no rate heterogeneity. Hitherto, no phylogenetic analysis of all major eumalacostracan taxa (orders) has either combined evidence from multiple loci, or combined molecular and morphological evidence. Results We combined evidence from four nuclear ribosomal and mitochondrial loci (18S rRNA, 28S rRNA, 16S rRNA, and cytochrome c oxidase subunit I) with a newly synthesized morphological dataset. We tested the homogeneity of data partitions, both in terms of character congruence and the topological congruence of inferred trees. We also performed Bayesian and parsimony analyses on separate and combined partitions, and tested the contribution of each partition. We tested for potential long-branch attraction (LBA) using taxon deletion experiments, and with relative rate tests. Additionally we searched for molecular polytomies (spurious clades). Lastly, we investigated the phylogenetic stability of taxa, and assessed their impact on inferred relationships over the whole tree. We detected significant conflict between data partitions, especially between morphology and molecules. We found significant rate heterogeneity between species for both the 18S rRNA and combined datasets, introducing the possibility of LBA. As a test case, we showed that LBA probably affected the position of Spelaeogriphacea in the combined molecular evidence analysis. We also demonstrated that several clades, including the previously reported and surprising clade of Amphipoda plus Spelaeogriphacea, are 'supported' by zero length branches. Furthermore we showed that different sets of

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

    PubMed

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

    2017-06-18

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

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

    USGS Publications Warehouse

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

    2015-01-01

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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. Comparison of laboratory single species and field population-level effects of the pyrethroid insecticide lambda-cyhalothrin on freshwater invertebrates.

    PubMed

    Schroer, A F W; Belgers, J D M; Brock, T C M; Matser, A M; Maund, S J; Van den Brink, P J

    2004-04-01

    The toxicity of the pyrethroid insecticide lambda-cyhalothrin to freshwater invertebrates has been investigated using data from short-term laboratory toxicity tests and in situ bioassays and population-level effects in field microcosms. In laboratory tests, patterns of toxicity were consistent with previous data on pyrethroids. The midge Chaoborus obscuripes was most sensitive (48- and 96-h EC50 = 2.8 ng/L). Other insect larvae (Hemiptera, Ephemeroptera) and macrocrustacea (Amphipoda, Isopoda) were also relatively sensitive, with 48- and 96-h EC50 values between 10 and 100 ng/L. Generally, microcrustacea (Cladocera, Copepoda) and larvae of certain insect groups (Odonata and Chironomidae) were less sensitive, with 48-h EC50 values higher than 100 ng/L. Mollusca and Plathelminthes were insensitive and were unaffected at concentrations at and above the water solubility (5 microg/L). Generally, the EC50 values based on initial population responses in field enclosures were similar to values derived from laboratory tests with the same taxa. Also, the corresponding fifth and tenth percentile hazard concentrations (HC5 and HC10) were similar (laboratory HC5 = 2.7 ng/L and field HC5 = 4.1 ng/L; laboratory and field HC10 = 5.1 ng/L), at least when based on the same sensitive taxonomic groups (insects and crustaceans) and when a similar concentration range was taken into account. In the three field enclosure experiments and at a treatment level of 10 ng/L, consistent effects were observed for only one population (Chaoborus obscuripes), with recovery taking place within 3 to 6 weeks. The laboratory HC5 (2.7 ng/L) and HC10 (5.1 ng/L) based on acute EC50 values of all aquatic arthropod taxa were both lower than this 10 ng/L, a concentration that might represent the "regulatory acceptable concentration." The HC5 and HC10 values in this study in The Netherlands (based on static laboratory tests with freshwater arthropods) were very similar to those derived from a previous study in

  15. 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

  16. 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

  17. 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.

  18. Fish and Aquatic Invertebrate Communities in Waterways, and Contaminants in Fish, at the Barataria Preserve of Jean Lafitte National Historical Park and Preserve, Louisiana, 1999-2000

    USGS Publications Warehouse

    Swarzenski, Christopher M.; Mize, Scott V.; Thompson, Bruce A.; Peterson, Gary W.

    2004-01-01

    , floating rafts of aquatic plants). Individuals from 84 genera belonging to 51 families were identified. Diptera (true flies) was the most diverse group. Malacostraca (crustaceans), especially Amphipoda (scuds and sideswimmers), were the most abundant (36 percent). Total abundance and taxa richness of aquatic invertebrates were comparable during the March and July sampling in 1999, but were lower in samples collected from the same habitat at all three sites in April 2000. About 106 individuals were identified and enumerated from the depositional-targeted habitat (DTH, bottom material). Individuals from 7 genera belonging to 9 families were identified. Diptera was the most diverse group, and Annelida, especially tubificid worms, were the most abundant organisms identified (52 percent). Total abundance and composition of aquatic invertebrate communities differed between RTH and DTH at all three sites in April 2000. Organic compounds in whole fish, and trace elements, iron, and manganese in fillets, were analyzed in bowfin (Amia calva), bluegill (Lepomis macrochirus), largemouth bass (Micropterus salmoides), and common carp (Cyprinus carpio). Organic compounds were not detected. Mercury was detected in fillets of all four species. Highest concentrations of mercury were detected in fillets from bowfin and largemouth bass. Mercury concentrations increased with increasing weight in the three predatory fish species (bowfin, bluegill, and largemouth bass), but were much lower, relative to weight, in the omnivore, common carp. Chromium concentrations were detected in tissue of the two larger fish, bowfin and common carp. Cadmium and lead were not detected in any samples. Mercury concentrations for larger predatory fish caught in Preserve waterways may be a concern if the fish are frequently consumed by humans. The process of mercury accumulation appears to be natural, and not related to a local source problem. Mercury concentrations in comparable fish tissue at

  19. 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

    Krieger, Jakob; Sandeman, Renate E; Sandeman, David C; Hansson, Bill S; Harzsch, Steffen

    2010-09-10

    mechanosensory skills that are comparable to those of marine Crustacea. 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.

  20. 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