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Sample records for lymnocardiidae mollusca bivalvia

  1. Fauna Europaea: Mollusca - Bivalvia.

    Science.gov (United States)

    Araujo, Rafael; de Jong, Yde

    2015-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. For the Mollusca-Bivalvia, data from 5 families (Margaritiferidae, Unionidae, Sphaeriidae, Cyrenidae, Dreissenidae) containing 55 species are included in this paper. European freshwater bivalves belong to the Orders Unionoida and Cardiida. All the European unionoids are included in the superfamily Unionoidea, the freshwater mussels or naiads. The European cardiids belong to the following three superfamilies: Cardioidea, Cyrenoidea and Dreissenoidea. Among the Unionoidea there are the most imperilled animal groups on the planet while the Cardioidea includes the cosmopolitan genus Pisidium, the Cyrenoidea the Asiatic clam (Corbiculafluminea) and the Dreissenoidea the famous invasive zebra mussel (Dreissenapolymorpha). Basic information is summarized on their taxonomy and biology. Tabulations include a complete list of the current estimated families, genera and species.

  2. De tweekleppigen van het Noordzeekanaal (Mollusca: Bivalvia).

    NARCIS (Netherlands)

    Haaren, van T.; Tempelman, D.

    2006-01-01

    The bivalves of the Noordzeekanaal (Mollusca: Bivalvia) In recent years, the macrobenthos of the Noordzeekanaal area, west of Amsterdam, has been surveyed intensively. The area consists of a main, brackish channel and a set of deep sea harbours. It was discovered that several bivalve species were pr

  3. Mitogenomics reveals two subspecies in Coelomactra antiquata (Mollusca: Bivalvia).

    Science.gov (United States)

    Meng, Xueping; Shen, Xin; Zhao, Nana; Tian, Mei; Liang, Meng; Hao, Jue; Cheng, Hanliang; Yan, Binlun; Dong, Zhiguo; Zhu, Xiaoling

    2013-04-01

    The mitochondrial genome sequence of Coelomactra antiquata (Mollusca: Bivalvia) in Zhangzhou (zz-mtDNA) was fully sequenced and compared with that in Rizhao (rz-mtDNA) in this study. A tRNA (tRNA (Met) ) located between tRNA (Ala) and cox1 genes was identified in zz-mtDNA but not in rz-mtDNA. The largest non-coding region (NCR; MNR) contained 11 copies 99nt tandem repeat sequences exclusively in rz-mtDNA, while the second largest NCR with 400 bp between tRNA (Ala) and tRNA (Met) in zz-mtDNA was absent in rz-mtDNA. Secondary structures of ZZ and RZ C. antiquata rRNAs are significantly different. The mitochondrial genomic characteristics clearly indicate that there are at least two subspecies in C. antiquata.

  4. Comparative genomics of vesicomyid clam (Bivalvia: Mollusca chemosynthetic symbionts

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    Girguis Peter R

    2008-12-01

    Full Text Available Abstract Background The Vesicomyidae (Bivalvia: Mollusca are a family of clams that form symbioses with chemosynthetic gamma-proteobacteria. They exist in environments such as hydrothermal vents and cold seeps and have a reduced gut and feeding groove, indicating a large dependence on their endosymbionts for nutrition. Recently, two vesicomyid symbiont genomes were sequenced, illuminating the possible nutritional contributions of the symbiont to the host and making genome-wide evolutionary analyses possible. Results To examine the genomic evolution of the vesicomyid symbionts, a comparative genomics framework, including the existing genomic data combined with heterologous microarray hybridization results, was used to analyze conserved gene content in four vesicomyid symbiont genomes. These four symbionts were chosen to include a broad phylogenetic sampling of the vesicomyid symbionts and represent distinct chemosynthetic environments: cold seeps and hydrothermal vents. Conclusion The results of this comparative genomics analysis emphasize the importance of the symbionts' chemoautotrophic metabolism within their hosts. The fact that these symbionts appear to be metabolically capable autotrophs underscores the extent to which the host depends on them for nutrition and reveals the key to invertebrate colonization of these challenging environments.

  5. New records of Protobranchia (Mollusca: Bivalvia in the Peruvian Sea

    Directory of Open Access Journals (Sweden)

    Carlos Paredes

    2014-06-01

    Full Text Available The following species of Bivalvia have been recorded for the first time for Peruvian waters: Nucula (Nucula iphigenia (Dall, 1908; Ennucula cardara (Dall, 1916; Nuculana (Nuculana extenuata (Dall, 1897; Orthoyoldia panamensis (Dall, 1908. These bivalves were collected in the platform and continental slope down to depths of 864 meters.

  6. The effects of mercury exposure on the surface morphology of gill filaments in Perna perna (Mollusca: Bivalvia)

    CSIR Research Space (South Africa)

    Gregory, MA

    1999-01-01

    Full Text Available Exposure on the Surface Morphology of Gill Filaments in Perna perna (Mollusca: Bivalvia) M. A. GREGORY *, R. C. GEORGE , D. J. MARSHALL , A. ANANDRAJ and T. P. MCCLURG? Electron Microscope Unit and Department of Zoology, University of Durban... 259, 51?60. Grace A. L.,Ganey, L. F. Jr. (1987) The eC128ects of copper on the heart rate and ?ltration rate of M. edulis. Marine Pollution Bulletin 18, 87?91. 120 Marine Pollution Bulletin Gregory, M. A., George, R. C. and McClurg. (1996...

  7. Mollusca: Bivalvia

    African Journals Online (AJOL)

    1987-06-05

    Jun 5, 1987 ... membrane of which is thickened, connect the spermatids. (Figure 2) . As the ... vesicle, which is of uniform electron opacity (0,5 f1m diameter) .... macerophyl/a and Spisula solidissima the outer electron- opaque region of the ...

  8. Comparative mitogenomic analysis reveals cryptic species: A case study in Mactridae (Mollusca: Bivalvia).

    Science.gov (United States)

    Shen, Xin; Meng, Xue Ping; Chu, Ka Hou; Zhao, Na Na; Tian, Mei; Liang, Meng; Hao, Jue

    2014-12-01

    The Chinese surf clam Mactra chinensis Philippi, 1846 is a commercially important marine bivalve belonging to the family Mactridae (Mollusca: Bivalvia). In this study, the M. chinensis mitochondrial genomic features are analyzed. The genome has 34 genes on the same strand, lacking atp8 and both trnS (trnS1 and trnS2) as compared with the typical gene content of metazoan mitochondrial genomes. The A+T content of M. chinensis mitochondrial genome is 63.72%, which is slightly lower than that of M. veneriformis (67.59%) and Coelomactra antiquata (64.33% and 64.14% for the samples from Ri Zhao, Shandong Province, and Zhang Zhou, Fujian Province, China, respectively) in the same family. There are 22 NCRs in the M. chinensis mitochondrial genome, accounting for 12.91% of the genome length. The longest NCR (1,075bp in length) is located between trnT and trnQ. A TRS (127bp×8.15) accounts for 96.3% (1,035/1,075) of this NCR. The occurrence of TRS in NCR is shared by the two Mactra mitochondrial genomes, but is not found in the two Coelomactra mitochondrial genomes. A phylogenetic tree constructed based on 12 PCGs of 25 bivalve mitochondrial genomes shows that all seven genera (Mactra, Coelomactra, Paphia, Meretrix, Solen, Mytilus, and Crassostrea) constitute monophyletic groups with very high support values. Pairwise genetic distance analyses indicate that the genetic distance of C. antiquata from the two localities is 0.084, which is greater than values between congeneric species, such as those in Mactra, Mytilus, Meretrix, and Crassostrea. The results show that the C. antiquata from the two localities represent cryptic species. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Unionid bivalves (Mollusca: Bivalvia: Unionidae) of Presque Isle Bay, Erie, Pennsylvania

    Science.gov (United States)

    Masteller, E.C.; Maleski, K.R.; Schloesser, D.W.

    1993-01-01

    The purpose of this study was to determine species composition and relative abundance of unionid bivalves (Mollusca: Bivalvia: Unionidae) in Presque Isle Bay, Erie, Pennsylvania 1990-1992. This information was compared with data from the only other extensive survey of unionids in the bay conducted in 1909-1911 (Ortmann 1919) to assess changes over the 80 years preceding the present study. A total of 1,540 individuals representing 18 species were collected in 1990-1992. Five relatively common species (between 7 and 42% of total individuals), six uncommon species (2 and 6%), and seven rare species (<1%) were found. The rare species were Anodontoides ferussacianus, Lasmigona costata, Ligumia recta, Ptychobranchus fasciolaris, Quadrula pustulosa pustulosa, Strophitus undaulatus, and Truncilla donaciformis. Five of the species found in Presque Isle Bay (Leptodea fragilis, Ligumia nasuta, Potamilus alatus, Quadrula quadrula, and Truncilla donaciformis) are listed as critically imperiled and one species (Truncilla truncata) as extirpated in the State of Pennsylvania by the Western Pennsylvania Conservancy. Comparisons between unionid populations in 1909-1911 and 1990-1992 indicate few substantial changes occurred during the past 80 years. A total of 22 species were found; 21 in 1909-1911 and 18 in 1990-1992. Seventeen species were found in both studies, an additional four in 1909-1911 and one in 1990-1992. The relative abundance of 11 of the 17 species found in both studies remained stable (i.e., common or uncommon) over the past 80 years. Only four species listed as uncommon in 1909-1911 were listed as rare in 1990-1992. However, the invasion of the zebra mussel (Dreissena polymorpha) is considered a threat to the continued existence of the entire Unionidae fauna in Presque Isle Bay, a unique habitat of the Great Lakes.

  10. Phylogenetic relationships of chemoautotrophic bacterial symbionts of Solemya velum say (Mollusca: Bivalvia) determined by 16S rRNA gene sequence analysis.

    OpenAIRE

    Eisen, J. A.; Smith, S W; Cavanaugh, Colleen Marie

    1992-01-01

    The protobranch bivalve Solemya velum Say (Mollusca: Bivalvia) houses chemoautotrophic symbionts intracellularly within its gills. These symbionts were characterized through sequencing of polymerase chain reaction-amplified 16S rRNA coding regions and hybridization of an Escherichia coli gene probe to S. velum genomic DNA restriction fragments. The symbionts appeared to have only one copy of the 16S rRNA gene. The lack of variability in the 16S sequence and hybridization patterns within and b...

  11. Molecular phylogenetic analysis supports a Gondwanan origin of the Hyriidae (Mollusca: Bivalvia: Unionida) and the paraphyly of Australasian taxa.

    Science.gov (United States)

    Graf, Daniel L; Jones, Hugh; Geneva, Anthony J; Pfeiffer, John M; Klunzinger, Michael W

    2015-04-01

    The freshwater mussel family Hyriidae (Mollusca: Bivalvia: Unionida) has a disjunct trans-Pacific distribution in Australasia and South America. Previous phylogenetic analyses have estimated the evolutionary relationships of the family and the major infra-familial taxa (Velesunioninae and Hyriinae: Hyridellini in Australia; Hyriinae: Hyriini, Castaliini, and Rhipidodontini in South America), but taxon and character sampling have been too incomplete to support a predictive classification or allow testing of biogeographical hypotheses. We sampled 30 freshwater mussel individuals representing the aforementioned hyriid taxa, as well as outgroup species representing the five other freshwater mussel families and their marine sister group (order Trigoniida). Our ingroup included representatives of all Australian genera. Phylogenetic relationships were estimated from three gene fragments (nuclear 28S, COI and 16S mtDNA) using maximum parsimony, maximum likelihood, and Bayesian inference, and we applied a Bayesian relaxed clock model calibrated with fossil dates to estimate node ages. Our analyses found good support for monophyly of the Hyriidae and the subfamilies and tribes, as well as the paraphyly of the Australasian taxa (Velesunioninae, (Hyridellini, (Rhipidodontini, (Castaliini, Hyriini)))). The Hyriidae was recovered as sister to a clade comprised of all other Recent freshwater mussel families. Our molecular date estimation supported Cretaceous origins of the major hyriid clades, pre-dating the Tertiary isolation of South America from Antarctica/Australia. We hypothesize that early diversification of the Hyriidae was driven by terrestrial barriers on Gondwana rather than marine barriers following disintegration of the super-continent.

  12. The influence of fish cage culture on δ13C and δ15N of filter-feeding Bivalvia (Mollusca).

    Science.gov (United States)

    Benedito, E; Figueroa, L; Takeda, A M; Manetta, G I

    2013-11-01

    The objective of this study was to evaluate the effect of Oreochromis niloticus cage culture promoted variations in the δ13C and δ15N in Corbicula fluminea (Mollusca; Bivalvia) and in the sediment of an aquatic food web. Samples were taken before and after net cage installation in the Rosana Reservoir (Paranapanema River, PR-SP). Samples of specimens of the bivalve filterer C. fluminea and samples of sediment were collected using a modified Petersen grab. All samples were dried in an oven (60 °C) for 72 hours, macerated to obtain homogenous fine powders and sent for carbon (δ13C) and nitrogen (δ15N) isotopic value analysis in a mass spectrometer. There were significant differences in the δ13C and δ15N values of the invertebrate C. fluminea between the beginning and the end of the experiment. There were no differences between the δ13C and δ15N values of sediment. These results indicate that the installation of fish cage culture promoted impacts in the isotopic composition of the aquatic food web organisms, which could exert influence over the native species and the ecosystem.

  13. Thermal dependency of shell growth, microstructure, and stable isotopes in laboratory-reared Scapharca broughtonii (Mollusca: Bivalvia)

    Science.gov (United States)

    Nishida, Kozue; Suzuki, Atsushi; Isono, Ryosuke; Hayashi, Masahiro; Watanabe, Yusuke; Yamamoto, Yuzo; Irie, Takahiro; Nojiri, Yukihiro; Mori, Chiharu; Sato, Mizuho; Sato, Kei; Sasaki, Takenori

    2015-07-01

    We experimentally examined the growth, microstructure, and chemistry of shells of the bloody clam, Scapharca broughtonii (Mollusca: Bivalvia), reared at five temperatures (13, 17, 21, 25, and 29°C) with a constant pCO2 condition (˜450 μatm). In this species, the exterior side of the shell is characterized by a composite prismatic structure; on the interior side, it has a crossed lamellar structure on the interior surface. We previously found a negative correlation between temperature and the relative thickness of the composite prismatic structure in field-collected specimens. In the reared specimens, the relationship curve between temperature and the growth increment of the composite prismatic structure was humped shaped, with a maximum at 17°C, which was compatible with the results obtained in the field-collected specimens. In contrast, the thickness of the crossed lamellar structure was constant over the temperature range tested. These results suggest that the composite prismatic structure principally accounts for the thermal dependency of shell growth, and this inference was supported by the finding that shell growth rates were significantly correlated with the thickness of the composite prismatic structure. We also found a negative relationship between the rearing temperature and δ18O of the shell margin, in close quantitative agreement with previous reports. The findings presented here will contribute to the improved age determination of fossil and recent clams based on seasonal microstructural records.

  14. GENETIC DIVERSITY OF FIVE FRESHWATER MUSSELS IN GENUS ANODONTA (MOLLUSCA: BIVALVIA) REVEALED BY RAPD ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Unionidae(Bivalvia)are distributed infreshwaters,and represent a significanttaxonof benthic community[1].In China,freshwater mussels are abundant resources[2].Since1949,substantial investigations onthe unionidfau-na had been undertakenin China[3—8].Withreference tooverseas research[9,10],a preliminary reorganization onthe Unionidae was performed accordingtosome classifica-tion characteristics such as shell shape,larvae character-istics,and breeding habit[11].Due tothe serious conver-gence of freshwater muss...

  15. Spermatozoa and spermatogenesis in the northern quahaug Mercenaria mercenaria (Mollusca, Bivalvia)

    Science.gov (United States)

    Ying, Xue-Ping; Yang, Wan-Xi; Dahms, Hans-U.; Lin, Zhihua; Chai, Xueliang

    2008-12-01

    We studied the ultrastructure of spermatogenesis and spermatozoa in the northern quahaug, the clam Mercenaria mercenaria. Spermatogenetic cells gradually elongate. Mitochondria gradually fuse and increase in size and electron density. During spermatid differentiation, proacrosomal vesicles migrate towards the presumptive anterior pole of the nucleus and eventually form the acrosome. The spermatozoon of M. mercenaria is of a primitive type. It is composed of head, mid-piece, and tail. The acrosome shows a subacrosomal space with a short conical contour. The slightly curved nucleus of the spermatozoon contains fine-grained dense chromatin. The middle piece consists of a centriolar complex which is surrounded by four mitochondria. The flagellum has a standard “9 + 2” microtubular structure. The ultrastructure of spermatozoa and spermatogenesis of M. mercenaria shares a number of features with other species of the family Veneridae. M. mercenaria may be a suitable model species for further investigations into the mechanisms of spermatogenesis in the Bivalvia.

  16. Phylogenetic relationships of chemoautotrophic bacterial symbionts of Solemya velum say (Mollusca: Bivalvia) determined by 16S rRNA gene sequence analysis.

    Science.gov (United States)

    Eisen, J A; Smith, S W; Cavanaugh, C M

    1992-05-01

    The protobranch bivalve Solemya velum Say (Mollusca: Bivalvia) houses chemoautotrophic symbionts intracellularly within its gills. These symbionts were characterized through sequencing of polymerase chain reaction-amplified 16S rRNA coding regions and hybridization of an Escherichia coli gene probe to S. velum genomic DNA restriction fragments. The symbionts appeared to have only one copy of the 16S rRNA gene. The lack of variability in the 16S sequence and hybridization patterns within and between individual S. velum organisms suggested that one species of symbiont is dominant within and specific for this host species. Phylogenetic analysis of the 16S sequences of the symbionts indicates that they lie within the chemoautotrophic cluster of the gamma subdivision of the eubacterial group Proteobacteria.

  17. Spatial patterns of Pisidium chilense (Mollusca Bivalvia and Hyalella patagonica (Crustacea, Amphipoda in an unpolluted stream in Navarino island (54° S, Cape Horn Biosphere Reserve

    Directory of Open Access Journals (Sweden)

    Patricio De Los Ríos Escalante

    2017-01-01

    Full Text Available The southern South American inland waters have many endemic species and some of them are considered as endangered for IUCN, that inhabits in unpolluted ecosystems, one of these ecosystems are the sub-Antarctic perennial forests located in the Cape Horn Biosphere Reserve at 54° S. The aim of the present study is to analyze the spatial patterns of Pisidium chilense Ituarte, 1999 (Mollusca Bivalvia and Hyalella patagonica (Cunningham, 1871 (Crustacea, Amphipoda in an unpolluted stream. Both species had aggregated spatial distribution, both have a negative binomial distribution pattern, and both are associated. The present results would agree with similar patterns in Patagonian rivers where both species coexist.

  18. Comparative morphology among representatives of main taxa of Scaphopoda and basal protobranch Bivalvia (Mollusca

    Directory of Open Access Journals (Sweden)

    Luiz Ricardo L. Simone

    2009-01-01

    Full Text Available This study deals with detailed morphology and anatomy of 4 species of Scaphopoda and 5 species of protobranch Bivalvia. Both classes are traditionally grouped in the taxon Diasoma, which has been questioned by different methodologies, such as molecular and developmental. This study is developed under a phylogenetic methodology with the main concern in performing it in an intelligible and testable methodology. The analyzed Scaphopoda species came from the Brazilian coast and belong to the family Dentaliidae [(1 Coccodentalium carduus; (2 Paradentalium disparile] and Gadiliidae; [(3 Polyschides noronhensis, n. sp. from Fernando de Noronha Archipelago; (4 Gadila braziliensis]. These species represent the main branches of the class Scaphopoda. From protobranch bivalves, representatives of the families Solemyidae [(5 Solemya occidentalis, from Florida; S. notialis, n. sp. from S.E. Brazil], Nuculanidae [(6 Propeleda carpentieri from Florida], and Nuculidae [(7 Ennucula puelcha, from south Brazil] are included. These species represent the main branches of the basal Bivalvia. The descriptions on the anatomy of S. occidentalis and of P. carpentieri are published elsewhere. The remaining are included here, for which a complete taxonomical treatment is performed. Beyond these species, representatives of other taxa are operationally included as part of the ingroup (indices are then shared with them, as a procedure to test the morphological monophyly of Diasoma. These taxa are: two lamellibranch bivalves [(8 Barbatia - Arcidae; (9 Serratina - Tellinidae; both published elsewhere;, and Propilidium (10 Patellogastropoda, and (11 Nautilus, basal Cephalopoda, based on basal taxa. The effective outgroups are (12 Neopilina (Monoplacophora and (13 Hanleya (Polyplacophora. The phylogenetic analysis based on morphology revealed that the taxon Diasoma is supported by 14 synapomorphies, and is separated from Cyrtosoma (Gastropoda + Cephalopoda. Although they are not

  19. Molecular phylogeny of pearl oysters and their relatives (Mollusca, Bivalvia, Pterioidea

    Directory of Open Access Journals (Sweden)

    Tëmkin Ilya

    2010-11-01

    Full Text Available Abstract Background The superfamily Pterioidea is a morphologically and ecologically diverse lineage of epifaunal marine bivalves distributed throughout the tropical and subtropical continental shelf regions. This group includes commercially important pearl culture species and model organisms used for medical studies of biomineralization. Recent morphological treatment of selected pterioideans and molecular phylogenetic analyses of higher-level relationships in Bivalvia have challenged the traditional view that pterioidean families are monophyletic. This issue is examined here in light of molecular data sets composed of DNA sequences for nuclear and mitochondrial loci, and a published character data set of anatomical and shell morphological characters. Results The present study is the first comprehensive species-level analysis of the Pterioidea to produce a well-resolved, robust phylogenetic hypothesis for nearly all extant taxa. The data were analyzed for potential biases due to taxon and character sampling, and idiosyncracies of different molecular evolutionary processes. The congruence and contribution of different partitions were quantified, and the sensitivity of clade stability to alignment parameters was explored. Conclusions Four primary conclusions were reached: (1 the results strongly supported the monophyly of the Pterioidea; (2 none of the previously defined families (except for the monotypic Pulvinitidae were monophyletic; (3 the arrangement of the genera was novel and unanticipated, however strongly supported and robust to changes in alignment parameters; and (4 optimizing key morphological characters onto topologies derived from the analysis of molecular data revealed many instances of homoplasy and uncovered synapomorphies for major nodes. Additionally, a complete species-level sampling of the genus Pinctada provided further insights into the on-going controversy regarding the taxonomic identity of major pearl culture species.

  20. Exotic molluscs (Mollusca, Gastropoda et Bivalvia in Santa Catarina State, Southern Brazil region: check list and regional spatial distribution

    Directory of Open Access Journals (Sweden)

    A. Ignacio Agudo-Padrón

    2011-06-01

    Full Text Available A total of twenty-one exotic mollusc taxa were assessed for Santa Catarina State (SC, fifteen Gastropoda andsix Bivalvia (twelve terrestrial, five limnic/freshwater - three gastropods and two bivalves, and four marinebivalves. Of these, fourteen are confirmed as invasive species (nine terrestrial, three limnic/freshwater, andtwo marine.

  1. Complete mitochondrial genome of Coelomactra antiquata (Mollusca: Bivalvia): The first representative from the family Mactridae with novel gene order and unusual tandem repeats.

    Science.gov (United States)

    Meng, Xueping; Zhao, Nana; Shen, Xin; Hao, Jue; Liang, Meng; Zhu, Xiaolin; Cheng, Hanliang; Yan, Binlun; Liu, Zhaopu

    2012-06-01

    The complete mitochondrial genome plays an important role in the accurate inference of phylogenetic relationships among metazoans. Mactridae, also known as trough shells or duck clams, is an important family of marine bivalve clams in the order Veneroida. Here we present the complete mitochondrial genome sequence of the Xishishe Coelomactra antiquata (Mollusca: Bivalvia), which is the first representative from the family Mactridae. The mitochondrial genome of C. antiquata is of 17,384bp in length, and encodes 35 genes, including 12 protein-coding, 21 transfer RNA, and 2 ribosomal RNA genes. Compared with the typical gene content of animal mitochondrial genomes, atp8 and tRNAS(2) are missing. Gene order of the mitochondrial genome of C. antiquata is unique compared with others from Veneroida. In the mitochondrial genome of the C. antiquata, a total of 2189bp of non-coding nucleotides are scattered among 26 non-coding regions. The largest non-coding region contains one section of tandem repeats (99 bp×11), which is the second largest tandem repeats found in the mitochondrial genomes from Veneroida. The phylogenetic trees based on mitochondrial genomes support the monophyly of Veneridae and Lucinidae, and the relationship at the family level: ((Veneridae+Mactridae)+(Cardiidae+Solecurtidae))+Lucinidae. The phylogenetic result is consistent with the morphological classification. Meanwhile, bootstrap values are very high (BP=94-100), suggesting that the evolutionary relationship based on mitochondrial genomes is very reliable. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. The influence of fish cage culture on δ{sup 13}C and δ{sup 15}N of filter-feeding Bivalvia (Mollusca)

    Energy Technology Data Exchange (ETDEWEB)

    Benedito, E.; Takeda, A.M., E-mail: eva@nupelia.uem.br [Universidade Estadual de Maringa (UEM), PR (Brazil). Nucleo de Pesquisas em Limnologia, Ictiologia e Aquicultura; Figueroa, L. [Universidade Estadual de Maringa (UEM), PR (Brazil). Pos-Graduacao em Ecologia de Ambientes Aquaticos Continentais; Manetta, GI. [Universidade Estadual de Maringa (UEM), PR (Brazil). Pos-Graduacao em Biologia Comparada

    2013-11-15

    The objective of this study was to evaluate the effect of Oreochromis niloticus cage culture promoted variations in the δ{sup 13}C and δ{sup 15}N in Corbicula fluminea (Mollusca; Bivalvia) and in the sediment of an aquatic food web. Samples were taken before and after net cage installation in the Rosana Reservoir (Paranapanema River, PR-SP). Samples of specimens of the bivalve filter C. fluminea and samples of sediment were collected using a modified Petersen grab. All samples were dried in an oven (60 °C) for 72 hours, macerated to obtain homogenous fine powders and sent for carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) isotopic value analysis in a mass spectrometer. There were significant differences in the δ{sup 13}C and δ{sup 15}N values of the invertebrate C. fluminea between the beginning and the end of the experiment. There were no differences between the δ{sup 13}C and δ{sup 15}N values of sediment. These results indicate that the installation of fish cage culture promoted impacts in the isotopic composition of the aquatic food web organisms, which could exert influence over the native species and the ecosystem. (author)

  3. [On the controversial questions of the taxonomy of Bivalvia (Mollusca): too many species or too few characters?].

    Science.gov (United States)

    Rizhinashvili, A L

    2011-01-01

    Problems emerging in the course of taxonomic studies and species diagnostics of freshwater bivalves are discussed by the example of one of the bivalve groups (the family Unionidae). It is shown that one of the causes of the current, diametrically opposing views on specific and generic systematics of Bivalvia is the fact that researchers revising taxonomic groups ignore complex analysis of several independent characters (conchological, anatomical, biochemical, genetic, etc.).

  4. (Born, 1778) (Mollusca: Bivalvia)

    African Journals Online (AJOL)

    1988-05-27

    May 27, 1988 ... Most populations had a unimodal size distribution in which small individuals ... exploited areas, suggesting that size distribution was unrelated to human explOitation. ... abundant on the east coast of southern Africa, where it.

  5. Fauna Europaea: Mollusca - Bivalvia

    NARCIS (Netherlands)

    Araujo, R.; de Jong, Y.

    2015-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The

  6. Systematic notes on the Mesodesmatidae (Mollusca, Bivalvia), and descriptions of a new species and a new subspecies

    NARCIS (Netherlands)

    Rooij-Schuiling, de L.A.

    1972-01-01

    In 1959, Mr. A. Hoogerwerf obtained a number of small Mollusca from the gizzard of a godwit (Limosa spec.) shot near Koerik, West Irian, New Guinea, that eventually came into my hands for identification. Though the specimens clearly belonged to a species of the genus Mesodesma (Mactracea, fam. Mesod

  7. The linked units of 5S rDNA and U1 snDNA of razor shells (Mollusca: Bivalvia: Pharidae).

    Science.gov (United States)

    Vierna, J; Jensen, K T; Martínez-Lage, A; González-Tizón, A M

    2011-08-01

    The linkage between 5S ribosomal DNA and other multigene families has been detected in many eukaryote lineages, but whether it provides any selective advantage remains unclear. In this work, we report the occurrence of linked units of 5S ribosomal DNA (5S rDNA) and U1 small nuclear DNA (U1 snDNA) in 10 razor shell species (Mollusca: Bivalvia: Pharidae) from four different genera. We obtained several clones containing partial or complete repeats of both multigene families in which both types of genes displayed the same orientation. We provide a comprehensive collection of razor shell 5S rDNA clones, both with linked and nonlinked organisation, and the first bivalve U1 snDNA sequences. We predicted the secondary structures and characterised the upstream and downstream conserved elements, including a region at -25 nucleotides from both 5S rDNA and U1 snDNA transcription start sites. The analysis of 5S rDNA showed that some nontranscribed spacers (NTSs) are more closely related to NTSs from other species (and genera) than to NTSs from the species they were retrieved from, suggesting birth-and-death evolution and ancestral polymorphism. Nucleotide conservation within the functional regions suggests the involvement of purifying selection, unequal crossing-overs and gene conversions. Taking into account this and other studies, we discuss the possible mechanisms by which both multigene families could have become linked in the Pharidae lineage. The reason why 5S rDNA is often found linked to other multigene families seems to be the result of stochastic processes within genomes in which its high copy number is determinant.

  8. Fauna Europaea: MolluscaBivalvia

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    Rafael Araujo

    2015-07-01

    European freshwater bivalves belong to the Orders Unionoida and Cardiida. All the European unionoids are included in the superfamily Unionoidea, the freshwater mussels or naiads. The European cardiids belong to the following three superfamilies: Cardioidea, Cyrenoidea and Dreissenoidea. Among the Unionoidea there are the most imperilled animal groups on the planet while the Cardioidea includes the cosmopolitan genus Pisidium, the Cyrenoidea the Asiatic clam (Corbicula fluminea and the Dreissenoidea the famous invasive zebra mussel (Dreissena polymorpha. Basic information is summarized on their taxonomy and biology. Tabulations include a complete list of the current estimated families, genera and species.

  9. Evaluation of the levels of Br, Cl, K, Mg, Mn and V in Perna perna mussels (Linnaeus, 1758: Mollusca Bivalvia) collected in the coast of Sao Paulo state, Brazil; Avaliacao dos teores de Br, Cl, K, Mg, Mn e V em mexilhoes Perna perna (Linnaeus, 1758: Mollusca Bivalvia) coletados no litoral do estado de Sao Paulo, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Daniele

    2012-07-01

    The coastal environment has been heavily altered by multiple environmental impacts of human activities, such as disposal of sewage from urban areas, the release of numerous chemical industries, agriculture and the flow of vessels, which can lead to accidental spills of oil and oil products, fuels and other products transported by sea. In this context, a means of determining concentrations of these potentially toxic substances in the sea water is the biomonitoring by means of different types of bivalves, which have been used by various researchers, in Brazil and other countries. With regard to bivalve mollusks, particularly mussels, their use in monitoring the marine contamination is mainly due to their wide geographic distribution, sessile habit and ability to concentrate toxic metals to 102-105 times in relation to the concentrations detected in water. In the present study, we employed the passive biomonitoring using the Perna perna bivalve mollusk with respect to the elements Br, Cl, K, Mg, Mn and V. These elements were chosen since they can be determined by INAA method (Instrumental Neutron Activation Analysis), by means of short irradiation which provides faster analyzes and also due to their importance from the standpoint of environmental or nutritional studies. The aim of this study was to evaluate the content of Br, Cl, K, Mg, Mn and V in samples of Perna perna mussels (Linnaeus, 1758: Mollusca, Bivalvia) collected in coastal regions of Sao Paulo subject to anthropogenic contamination (Ponta de Itaipu and Palmas Island, in Santos), comparing the values obtained in sites potentially impacted with the values of the control site in Praia da Cocanha, in Caraguatatuba. The collection points located in Sao Paulo coast are located in the geographical areas 23 Masculine-Ordinal-Indicator 37'S - 45 Degree-Sign 24' W (Caraguatatuba) and 23 Masculine-Ordinal-Indicator 57'S - 46 Masculine-Ordinal-Indicator 20' W (Santos). The collection of organisms

  10. Simbiontes associados com Anomalocardia brasiliana (Gmelin (Mollusca, Bivalvia, Veneridae na Ilha de Santa Catarina e região continental adjacente, Santa Catarina, Brasil Symbionts associated with Anomalocardia brasiliana (Gmelin (Mollusca, Bivalvia, Veneridae on Santa Catarina Island and adjacent continental region, Santa Catarina, Brazil

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    Guisla Boehs

    2004-12-01

    Full Text Available Berbigões, Anomalocardia brasiliana (Gmelin, 1791, de bancos naturais da Ilha de Santa Catarina e região continental adjacente (SC, Brasil, foram examinados quanto a presença de simbiontes. Holothuriophilus tomentosus (Ortmann, 1894 (Brachyura, Sphenia antillensis Dall & Simpson, 1901 (Bivalvia e poliquetos espionídeos (Polychaeta foram observados macroscopicamente. A análise das secções histológicas evidenciou esporocistos de trematódeos (Digenea, um metacestóide (Cestoda e dois ciliados (Ciliophora.Pointed venus, Anomalocardia brasiliana (Gmelin, 1791, from natural beds of Santa Catarina Island and adjacent continental region (SE Brazil were examined in respect of symbiotic associations. Holothuriophilus tomentosus (Ortmann, 1894 (Brachyura, Sphenia antillensis Dall & Simpson, 1901 (Bivalvia, and polychaete worms (Polychaeta were found by macroscopic diagnosis. By analysis of histological sections, it was noted trematode sporocysts (Digenea, a metacestode (Cestoda and two ciliates (Ciliophora.

  11. Comunidad de moluscos asociados al mejillón verde Perna viridis (Mollusca: Bivalvia y sus relaciones tróficas en la costa norte de la Península de Araya, Estado Sucre, Venezuela

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    Sioliz Villafranca

    2006-12-01

    Full Text Available Perna viridis es un bivalvo procedente del Indo-Pacífico que habita en la zona intermareal y ha invadido varios ecosistemas de la costa norte del estado Sucre, Venezuela. Con la finalidad de realizar un estudio sobre las comunidades de moluscos asociadas a esta especie y sus relaciones tróficas, se llevaron a cabo muestreos bimensuales entre octubre/97 y agosto/98, en un banco natural de mejillones a dos metros de profundidad en la costa norte de la península de Araya (10°40’N -48°63’W. Los organismos fueron recolectados delimitando el área con una cuadrícula de 0.25 m². Se identificaron los organismos hasta la categoría de especies utilizando claves específicas para moluscos y bibliográficamente se les determinó categoría trófica.Se capturó un total de 1 235 individuos de P. viridis y asociados a la especie 3 163 especímenes pertenecientes al phylum Mollusca, contenidos en tres clases: Bivalvia,Gastropoda y Polyplacophora. Éstas estuvieron representadas por 50 especies correspondientes a 10 órdenes, 24 familias; para los gasterópodos se contabilizaron 25 especies, para los bivalvos 22 y tres para los poliplacóforos. Del total de las especies, 40% fueron filtradoras, 26% carnívoras, 24% herbívoras y el 10% restante presentó dos categorías.De las filtradoras las más representativas fueron: Perna perna, Musculus lateralis, Crassostrea rhizophorae y Ostrea equestris; en el grupo de los carnívoros dominaron tres especies de la familia Columbellidae:Mitrella lunata, Anachis obesa y Nitidella ocellata y para el grupo de los herbívoros destacaron dos especies de la familia Fisurellidae: Diodora cayenensis y D. minuta. Se registraron dos especies filtradoras-detritívoras, y tres especies herbívoras-filtradoras representantes del género C repidula. El alto porcentaje de filtradores sería un indicativo de que dentro de este sistema probablemente hay una mayor disponibilidad de fracciones alimenticias para este grupo

  12. Megafauna recovered from a cold hydrocarbon seep in the deep Alaskan Beaufort Sea, including a new species of Axinus (Thracidae: Bivalvia: Mollusca)

    Science.gov (United States)

    Powell, C. L.; Valentich-Scott, P.; Lorenson, T. D.; Edwards, B. D.

    2011-12-01

    Several specimens of a new species of Axinus and a single well-worn gastropod columella provisionally assigned to the genus Neptunea (Buccinidae: Gastropoda: Mollusca) were recently recovered from at least two cores, the longest of which is 5.72 m long, from a large seafloor mound, informally named the Canning Seafloor Mound (CSM). The CSM is located at 2,530 m water depth on the Alaskan Beaufort Sea slope north of Camden Bay and is a fluid explosion feature containing methane hydrate and methane-saturated sediments overlying a folded and faulted deep basin. Only two modern species of Axinus are currently known. Axinus grandis (Verrill & Smith, 1885) is a northern Atlantic species and the recently described species, A. cascadiensis Oliver and Holmes (2007), is only known from Baby Bare Seamount, Cascadia Basin, northeastern Pacific Ocean. Common fragments, single valves, and a single articulated specimen represent this new Axinus species. These shells were distributed over nearly the entire length of the primary core. All specimens show wear and (or) dissolution. The age of these specimens is unknown and no living representatives were encountered. The genus Axinus has a fossil record back to the early Eocene in England and the Paleocene and Eocene in Egypt. Biogeographically the genus appears to have originated in the Tethys Sea and became established in the Atlantic Ocean during the Eocene, spreading across the Arctic Ocean in the late Tertiary. With the opening of the Bering Strait in the latest Miocene or early Pliocene the genus Axinus migrated southwest into the northeast Pacific. Interestingly, hydrocarbon seep deposits are also present on the adjacent North Slope of Alaska in the Marsh Anticline at Carter Creek, Camden Bay. These rocks, the Nuwok beds, contain abundant Thracidae bivalve of the genus Thracia, but not Axinus, however the rocks also represent cold seep deposits. These rocks have been variously dated from Oligocene to Pliocene and the exact age

  13. Perfil de lípidos y ácidos grasos de Perna viridis, mejillón verde (Mollusca: Bivalvia en el oriente venezolano y la costa oeste de Trinidad

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    Tamar Koftayan

    2011-03-01

    Full Text Available Los lípidos totales fueron extraídos, identificados y cuantificados por gravimetría, mediante TLC/FID (sistema Iatroscan. Los ácidos grasos de los lípidos totales, fosfolípidos y triacilgliceroles fueron identificados y cuantificados por cromatografía de gases. Las mayores concentraciones de lípidos totales se presentaron en las muestras de Los Cedros, La Brea y Chaguaramas con valores de 7.92, 7.74 y 7.53%; respectivamente y los valores mínimos en las de La Restinga (6.08%. En la composición lípidica, las muestras de Chacopata presentaron la menor concentración de fosfolípidos (48.86% y los máximos valores de colesterol (38.87% y triacilgliceroles (12.26%, y las muestras de La Esmeralda y Río Caribe exhibieron concentraciones máximas de fosfolípidos (88.71-84.93%, respectivamente y mínimas de colesterol (6.50-4.42%. En los lípidos totales, los ácidos grasos saturados se encontraron entre 15.04 y 65.55%, con máximos en muestras de La Esmeralda y mínimos en Chacopata y los poliinsaturados estuvieron entre 7.80 y 37.18%, con máximos valores en la Brea y mínimos en la Esmeralda. En los fosfolípidos, la concentración de ácidos grasos saturados estuvo entre 38.81 y 48.68% para las muestras de Chaguaramas y Chacopata, respectivamente; los ácidos grasos poliinsaturados se encontraron entre no detectado y 34.51%, con altas concentraciones en muestras de Los Cedros (27.97% y Chaguaramas (34.51%. En los triacilgliceroles, la composición de ácidos grasos saturados variaron entre 14.27 y 53.80%, con baja concentración en Chacopata y alta concentración en La Restinga; los ácidos grasos poliinsaturados estuvieron entre 4.66 y 35.55%, con valores menores en las muestras de Chacopata (4.66% y mayores en Chaguaramas. El consumo frecuente de Perna viridis es recomendable, debido a su alto contenido de fosfolípidos y ácidos grasos insaturados.Lipid and fatty acid profile of Perna viridis, Green Mussel (Mollusca: Bivalvia in

  14. Mollusca (terrestrial and marine Gastropods et Bivalvia from Morocco

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    Atanas Irikov

    2013-12-01

    Full Text Available Fifteen samples with molluscs are collected from various habitats and regions of Morocco, located in the seashore zone, as well as the central and the eastern parts of the country. We recorded 21 terrestrial and 15 marine species of molluscs. New localities and new species for the fauna of Morocco and the African continent are reported for the first time.

  15. Morphological and molecular diversity of Unionidae (Mollusca, Bivalvia from Portugal

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    Reis, J.

    2013-06-01

    Full Text Available Freshwater mussels from the family Unionidae are known to exhibit a high level of ecological phenotypic plasticity that is reflected in their shell shape. This variation has caused uncertainty on systematics and taxonomy of the group. Several naiad populations from nine river basins from Portugal were analyzed genetically, using two mitochondrial gene fragments (16SrRNA and Cytochrome Oxidase I and morphologically, using ANOVA analyses of shell dimmensions. Molecular phylogenetic analyses were used to revise the systematics and to infer an evolutionary hypothesis for the family at the western-most Atlantic Iberian Peninsula. Genetic and morphological data were in agreement and supported the occurrence of 5 species in the region: Anodonta anatina, Anodonta cygnea, Potomida littoralis, Unio tumidiformis and Unio delphinus. The differentiation of all these species, except A. cygnea, is thought to have taken place during the isolation of the Iberian Peninsula and formation of the current river basins in the Tertiary. The possibility of A. cygnea being a relatively recent introduction is discussed. Basic morphometric measures of the shell proved to be useful to separate Unio species, but also seem to be strongly affected by environmental conditions. The high intra-specific morphologic variation was partially related to the species’ high level of phenotypic plasticity, but seems to have an important role in evolutionary processes.Las náyades de la familia Unionidae tienen gran plasticidad fenotípica, lo que se refleja en la forma de su concha. Esta variabilidad morfológica ha sido causa de gran confusión en la taxonomía y sistemática del grupo. Se han estudiado, genética y morfológicamente, numerosas poblaciones de náyades provenientes de nueve cuencas hidrográficas portuguesas. Para ello se han analizando dos fragmentos de genes mitocondriales (ARNr 16S y Citocromo Oxidasa I así como diferentes variables morfológicas de la concha. Se han realizado además análisis filogenéticos para conocer la sistemática de la familia e inferir una hipótesis evolutiva de su distribución en el oeste de la península Ibérica. Los datos genéticos y morfológicos sugieren la existencia de cinco especies: Anodonta anatina, Anodonta cygnea, Potomida littoralis, Unio tumidiformis y Unio delphinus. La diferenciación de estas especies, con la excepción de A. cygnea, ha ocurrido durante el aislamiento de la península Ibérica y posterior formación de las actuales cuencas hidrográficas en el Terciario. Se discute la posibilidad de que la presencia de A. cygnea se deba a una introducción reciente. Los datos morfométricos analizados pueden ser útiles para separar las especies del género Unio, pero son también dependientes de las condiciones ambientales. La elevada variabilidad morfológica dentro de cada especie está relacionada con su plasticidad fenotípica, pero tiene a su vez un importante papel en el proceso evolutivo.

  16. [Energy metabolism and body mass ratio in bivalves mollusca (Mollusca: Bivalvia)].

    Science.gov (United States)

    Vladimirova, I G; Kleĭmenov, S Iu; Radzinskaia, L I

    2003-01-01

    On the basis of experimental and published data, the interspecific and intraspecific (ontogenetic) dependence of energy metabolism on body weight in bivalves was calculated. Changes in the parameters of intraspecific allometric dependence under the effect of environmental factors were analyzed. The rate of comparable standard metabolism (coefficient a at k = 0.76) was shown to vary in different taxonomic and zoogeographic groups of bivalves.

  17. Ocorrência do bivalve exótico Mytilopsis leucophaeta (Conrad (Mollusca, Bivalvia, no Brasil Occurrence of exotic bivalve Mytilopsis leucophaeta (Conrad (Mollusca, Bivalvia, in Brazil

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    José R. B. de Souza

    2005-12-01

    Full Text Available O molusco Mytilopsis leucophaeta (Conrad, 1831, natural da América do Norte, foi localizado no litoral de Pernambuco, Brasil, em 2004, trazido provavelmente por água de lastro de navios. Na região, sua distribuição atualmente abrange zonas estuarinas adjacentes ao Porto do Recife. Os organismos foram encontrados restritos à região entre-marés, formando agregados densos com até 176.800 ind./m².The mussel Mytilopsis leucophaeta (Conrad, 1831 is native to North America. It was found at Pernambuco Coast, northeastern Brazil, in 2004, probably brought by ships' ballast water. The distribution of this species has been now spread to estuarial area near Recife Harbour. They showed a clumped distribution with a maximum of 176,800 ind./m² only in the intertidal zone.

  18. Phylogenetic analysis of Pectinidae (Bivalvia) based on the ribosomal DNA internal transcribed spacer region

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The ribosomal DNA internal transcribed spacer (ITS) region is a useful genomic region for understanding evolutionary and genetic relationships. In the current study, the molecular phylogenetic analysis of Pectinidae (Mollusca: Bivalvia) was performed using the nucleotide sequences of the nuclear ITS region in nine species of this family. The sequences were obtained from the scallop species Argopecten irradians, Mizuhopecten yessoensis, Amusium pleuronectes and Mimachlamys nobilis, and compared with the published sequences of Aequipecten opercularis, Chlamys farreri, C. distorta, M. varia, Pecten maximus, and an outgroup species Perna viridis. The molecular phylogenetic tree was constructed by the neighbor-joining and maximum parsimony methods. Phylogenetic analysis based on ITS1, ITS2, or their combination always yielded trees of similar topology. The results support the morphological classifications of bivalve and are nearly consistent with classification of two subfamilies (Chlamydinae and Pectininae) formulated by Waller. However, A. irradians, together with A. opercularis made up of genera Amusium, evidences that they may belong to the subfamily Pectinidae. The data are incompatible with the conclusion of Waller who placed them in Chlamydinae by morphological characteristics. These results provide new insights into the evolutionary relationships among scallop species and contribute to the improvement of existing classification systems.

  19. Verspreiding en habitats van Unio caffer Krauss, 1848 (Bivalvia: Unionoida: Unionidae in Suid-Afrika gebaseer op die rekords in die databasis van die Nasionale Varswaterslakversameling

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    K. N. de Kock

    2010-01-01

    Full Text Available Die kosmopolities-verspreide Unionoida bereik hul grootste diversiteit in Noord-Amerika. In Suid-Afrika word twee genera van die familie Unionidae, naamlik Unio en Coelatura wat vier spesies insluit, aangetref. Hierdie artikel handel oor die verspreiding en habitats van Unio caffer Krauss, 1848 gebaseer op die rekords in die Nasionale Varswaterslakversameling (NVWSV van Suid-Afrika. Alhoewel dit elders in Suid-Afrika sporadies aangetref is, is die Wes-Kaap die enigste provinsie waarvan geen monster op rekord in die databasis van die NVWSV is nie. Van die 58 monsters wat op rekord is, is die meerderheid in riviere (32.8% en damme (20.7% versamel en in watertoestande wat as standhoudend, staande, helder en vars beskryf is. ’n Temperatuur-indeks wat vir hierdie spesie bereken is, het dit vyfde in rangorde geplaas van die 12 Bivalvia-spesies wat in die databasis verteenwoordig word op grond van ’n assosiasie met lae omgewingstemperature. ’n Besluitnemingsboom-analise het aangedui dat temperatuur, substratum en waterbronne die mees betekenisvolle bydrae gelewer het tot die daarstelling van die gedokumenteerde geografiese verspreiding van U. caffer. Omdat omvattende opnames van varswater Mollusca deur staatsinstansies reeds in die tagtigerjare van die vorige eeu uitgefaseer is en die meerderheid versamelpunte sedertdien nie weer gemonster is nie, is kennis oor hul huidige stand van bewaring en spesiediversiteit gebrekkig. Negatiewe resultate by drie voormalige lokaliteite van U. caffer wat wel intussen deur die outeurs besoek is, dui egter daarop dat die voortbestaan daarvan, soos van sommige verwante spesies elders in die wêreld, bedreig word. Dit word bepleit dat opnames van varswater Mollusca met die gedokumenteerde verspreiding in die databasis van die NVWSV as riglyn, beplan en uitgevoer behoort te word. Die resultate van sulke opnames behoort ’n groot bydrae te lewer om die huidige stand van die verspreiding en spesiediversiteit van

  20. Systematic reviews on the Mesodesmatidae (Mollusca, Bivalvia) I. The Genus Monterosatus Beu, 1971

    NARCIS (Netherlands)

    Rooij-Schuiling, de L.A.

    1977-01-01

    In trying to identify a small Mesodesma from West Irian, New Guinea, much material in the collections of several museums was studied. As a guide for the identification I at first used the revision of the Mesodesmatidae by Lamy (1914), which is based exclusively on the collections of the Parisian

  1. Effects of salinity on biomarker responses in Crassostrea rhizophorae (Mollusca, Bivalvia) exposed to diesel oil.

    Science.gov (United States)

    da Silva, Angela Zaccaron; Zanette, Juliano; Fernando Ferreira, Jaime; Guzenski, João; Marques, Maria Risoleta Freire; Bainy, Afonso Celso Dias

    2005-11-01

    Crassostrea rhizophorae is a euryhaline oyster that inhabits mangrove areas, which are widely distributed along the Brazilian coast. The aim of this study was to investigate the effects of salinity (9, 15, 25, and 35ppt) on the activities of glutathione S-transferase (GST), glucose 6-phosphate dehydrogenase (G6PDH), catalase (CAT), and acetylcholinesterase (AChE) in the digestive gland of this species after exposure to diesel oil for 7 days at nominal concentrations of 0.01, 0.1, and 1mlL(-1) and after depuration for 24h and 7 days. GST activity increased in a diesel oil concentration-dependent manner at salinities 25 and 15ppt and remained slightly elevated even after depuration periods of 24h and 7 days. No changes were observed in the activities of G6PDH, CAT, and AChE in the oysters exposed to diesel and depurated. Based on these results, GST activity in the digestive gland of C. rhizophorae might be used as a biomarker of exposure to diesel oil in sites where the salinity is between 15 and 25ppt, values usually observed in mangrove ecosystems.

  2. The sensorial structures of Spondylus americanus Hermann,1781 (Mollusca: Bivalvia, Spondylidae

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    Marina Gomes Viana

    2007-09-01

    Full Text Available Adult animals of Spondylus americanus were analyzed and specialized sensorial structures, the sensorial papillae and the eyes, were characterized. The sensorial papillae were projections on the edge of the mantle in form of light brown fingers which had function of percepting stimulus coming from the medium. They were constituted by loose conjunctive tissues with longitudinal muscular fibers and externally covered by ciliated cubic epithelium, which presented high amount of melanocytes that gave the coloration of the papillae. The eyes were more complex, being on small stalks histologically similar to the papillae. They exhibited a circular formate and had a metallic blue color. Theses structures were constituted by a corneo epithelium, cornea, lens, retina, basal stalk, periocular band and optical nerve. The eyes were distributed asymmetrically to both valves related with the sedentarism of the species. Right valve presented a smaller number of eyes when compared to left one.Foram examinados exemplares adultos de Spondylus. americanus Hermann, 1781 e estruturas especializadas na percepção de estímulos foram caracterizadas: as papilas sensoriais e os ocelos. As papilas sensoriais são projeções do bordo manto em forma de dedos de cor castanha e com a função de perceber estímulos vindo do meio, são constituídas por tecido conjuntivo frouxo contendo fibras musculares longitudinais e revestidas externamente por epitélio cúbico ciliado, o qual apresenta grande quantidade de melanócitos, que dão a coloração das papilas. Os ocelos são mais complexos, estando sobre pequenos pedúnculos histologicamente semelhante às papilas, têm formato circular e possui cor azul metálica. Constituí-se por um epitélio córneo, córnea, lente, retina, pedúnculo basal, banda periocular e nervo óptico. Os ocelos distribuem-se assimetricamente por ambas as valvas, o que está relacionado com o sedentarismo da espécie. A valva direita apresenta menor número de ocelos quando comparada a esquerda.

  3. Submarine canyons as the preferred habitat for wood-boring species of Xylophaga (Mollusca, Bivalvia)

    Science.gov (United States)

    Romano, C.; Voight, J. R.; Company, J. B.; Plyuscheva, M.; Martin, D.

    2013-11-01

    Submarine canyons are often viewed as natural “debris concentrators” on the seafloor. Organic substrates may be more abundant inside than outside canyon walls. To determine the effects of the presence these substrates in the Blanes submarine canyon (NW Mediterranean) and its adjacent western open slope, we deployed wood to study colonizing organisms. Three replicate pine and oak cubes (i.e. most common trees inland) were moored at 900, 1200, 1500 and 1800 m depth and collected after 3, 9 and 12 months. Wood from inside the canyon was significantly more heavily colonized by the five morphotypes of wood-boring bivalves than was wood on the adjacent open slope. Xylophaga sp. A dominated all wood types and locations, with peak abundance at 900 and 1200 m depth. Its growth rate was highest (0.070 mm d-1) during the first three months and was faster (or it recruits earlier) in pine than in oak. Size distribution showed that several recruitment events may have occurred from summer to winter. Xylophaga sp. B, appeared first after 9 months and clearly preferred pine over oak. As the immersion time was the same, this strongly supported a specific association between recruiters and type of substrate. Three morphotypes, pooled as Xylophaga spp. C, were rare and seemed to colonize preferentially oak inside the canyon and pine in the adjacent open slope. Individuals of Xylophaga were more abundant inside the canyon than in nearby off-canyon locations. Blanes Canyon may serve as a long-term concentrator of land-derived vegetal fragments and as a consequence sustain more animals. Are the species richness and abundance of wood-boring bivalves higher inside the canyon than on the adjacent open slope? Do the composition and density of the wood-boring bivalves change with deployment time and depth, as well as on the type of the sunken wood? What is the growth rate of the dominant wood-boring species?

  4. External morphology of spermatozoa and spermatozeugmata of the freshwater mussel Truncilla truncata (Mollusca: Bivalvia: Unionidae)

    Science.gov (United States)

    Waller, D.L.; Lasee, B.A.

    1997-01-01

    Truncilla truncata males release spherical aggregates of spermatozoa, called spermatozeugmata, at spawning. Sperm aggregates from other bivalve species have been described, but few detailed studies exist of the morphology of unionid spermatozeugmata and spermatozoa. We provide the first description of the external morphology of spermatozeugmata and spermatozoa of T. Truncata. The spermatozeugmata had an inside diameter of 76 mu m and contained 8000-9000 spermatozoa. Heads of spermatozoa were directed toward the center of the sphere into a translucent shell; tails were arranged radially and caused the spermatozeugmata to rotate. Spermatozoa of T. Truncata measured 3.3 mu m in length (excluding tail) and each had a head, a midpiece and a flagellum. We also documented the release of spermatozeugmata in two additional unionid species, Lampsilis cardium and Amblema plicata plicata.

  5. Taxonomic implications of molecular studies on Northern Brazilian Teredinidae (Mollusca: Bivalvia specimens

    Directory of Open Access Journals (Sweden)

    Sonia Maria Lima Santos

    2005-03-01

    Full Text Available The current taxonomy of the Teredinidae (shipworms is wholly based on morphology and up to now no molecular studies of the phylogeny of this group have been published. In the present study the relationships between four genera of the subfamilies Teredininae and Bankiinae were established and the efficiency of the 16S rRNA gene in characterizing four Teredinidae species was tested. Phylogenetic trees support the grouping of Bankia fimbriatula with Nausitora fusticula and of Neoteredo reynei with Psiloteredo healdi, but the genetic distances do not justify the classification of these species into two distinct subfamilies. The results show that B. fimbriatula, N. reynei and P. healdi specimens from the coast of the Brazilian state of Pará have five distinct 16S rRNA haplotypes, with one N. reynei haplotype differing from the other haplotypes in respect to at least seven sequences sites, indicating the existence of two very distinct sympatric lineages.

  6. Clarifying phylogenetic relationships and the evolutionary history of the bivalve order Arcida (Mollusca: Bivalvia: Pteriomorphia).

    Science.gov (United States)

    Combosch, David J; Giribet, Gonzalo

    2016-01-01

    The systematics of the bivalve order Arcida constitutes an unresolved conundrum in bivalve systematics. The current definition of Arcida encompasses two superfamilies: Limopsoidea, which includes the recent families Philobryidae and Limopsidae, and Arcoidea, which encompasses the families Arcidae, Cucullaeidae, Noetiidae, Glycymerididae and Parallelodontidae. This classification, however, is controversial particularly with respect to the position and taxonomic status of Glycymerididae. Previous molecular phylogenies were limited either by the use of only a single molecular marker or by including only a few limopsoid and glycymeridid taxa. The challenging nature of Arcida taxonomy and the controversial results of some of the previous studies, prompted us to use a broad range of taxa (55 species), three nuclear markers (18S rRNA, 28S rRNA and histone H3) and a wide range of algorithmic approaches. This broad but stringent approach led to a number of results that differ significantly from previous studies. We provide the first molecular evidence that supports the separation of Arcoidea from Limopsoidea, although the exact position of Glycymerididae remains unresolved, and the monophyly of Limopsoidea is algorithm-dependent. In addition, we present the first time-calibrated evolutionary tree of Arcida relationships, indicating a significant increase in the diversification of arcidan lineages at the beginning of the Cretaceous, around 140Ma. The monophyly of Arcida, which has been supported previously, was confirmed in all our analyses. Although relationships among families remain somehow unresolved we found support for the monophyly of most arcidan families, at least under some analytical conditions (i.e., Glycymerididae, Noetiidae, Philobryidae, and Limopsidae). However, Arcidae, and particularly Arcinae, remain a major source of inconsistency in the current system of Arcida classification and are in dire need of taxonomic revision.

  7. Epibiotic relationships on Zygochlamys patagonica (Mollusca, Bivalvia, Pectinidae) increase biodiversity in a submarine canyon in Argentina

    Science.gov (United States)

    Schejter, Laura; López Gappa, Juan; Bremec, Claudia Silvia

    2014-06-01

    The continental slope of the southern SW Atlantic Ocean has many distinguishable deep submarine canyons, varying in depth and extension. The benthic fauna within one of them, detected in April 2005 by means of a multibeam SIMRAD EM1002 sonar, and located at 43°35‧S to 59°33‧W, 325 m depth, was studied to discuss faunal affinities with the neighbouring Patagonian scallop fishing grounds located at upper slope depths. In order to add faunal information to the previous general study, we studied the epibiotic species settled on Patagonian scallops (the dominant species in the area) collected in the reference sampling site using a 2.5-m mouth-opening dredge, 10 mm mesh size. We sampled 103 scallops with shell heights between 22 and 69 mm; epibionts were recorded on both valves. We found 53 epibiotic taxa, which were most conspicuous on the upper valve. Bryozoa was the most diverse group (34 species) while Polychaeta was the most abundant group, recorded on 94% of the scallops. Stylasteridae (2 species) and Clavulariidae (Cnidaria) conform newly recorded epibionts on Z. patagonica and the sponge Tedania (Tedaniopsis) infundibuliformis also represents a new record for the SW Atlantic Ocean.

  8. Results of the Rumphius Biohistorical Expedition to Ambon : Part 6. Mollusca, Bivalvia, Pectinidae

    NARCIS (Netherlands)

    Dijkstra, H.H.

    1997-01-01

    During the Rumphius Biohistorical Expedition (1990) to Ambon 17 Pectinidae species were collected, nine of which were described by Rumphius (1705) and five illustrated by Rumphius. One species, viz. Decatopecten plica (Linnaeus, 1758), illustrated in Rumphius (1705: pl. 44, fig. O), has not been ref

  9. Size-differential feeding in Pinna nobilis L. (Mollusca: Bivalvia): Exploitation of detritus, phytoplankton and zooplankton

    Science.gov (United States)

    Davenport, John; Ezgeta-Balić, Daria; Peharda, Melita; Skejić, Sanda; Ninčević-Gladan, Živana; Matijević, Slavica

    2011-04-01

    The endangered fan shell Pinna nobilis is a large bivalve mollusc (<120 cm shell length) endemic to the Mediterranean that lives one-third buried in soft substrata, generally in shallow coastal waters. We hypothesised that P. nobilis of different sizes would ingest different food sources, because small fan shells will inhale material from closer to the substratum than do large fan shells. We studied stomach contents and faeces of 18 fan shells, 6 small (mean 23.0 cm length), 6 medium-sized (mean 41.5 cm length) and 6 large (mean 62.7 cm length) living in a small area of a low-energy coastal detritic bottom characterised by mud, sand and macroalgae at Mali Ston Bay, Croatia. We found that all P. nobilis ingested copious quantities of undetermined detritus (probably at least 95% of ingested material), phytoplankton, micro and mesozooplankton and pollen grains. Large P. nobilis stomach contents showed a preponderance of water column calanoid copepods, while small fan shells had higher numbers of bivalve larvae. All fan shells took in high numbers of harpacticoid copepods that are benthonic, feeding on microbial communities of detritus and benthic vegetation. There was also a significant selection of phytoplankton species, some apparently occurring between inhalation and ingestion. The stomach contents of small P. nobilis had a higher organic matter content than either medium-sized or large fan shells; this indicated that small fan shells ingested detritus of higher organic content than did larger P. nobilis. As the faeces of all P. nobilis had similar organic matter content, this also indicates higher assimilation efficiencies in small fan shells. The demonstration of differential dietary selectivity by different sized animals has implications for future trophic studies of this endangered species. This study also provides the first demonstration of predation on zooplankton by P. nobilis.

  10. Phylogeny and evolution of ontogeny of the family Oxytomidae Ichikawa, 1958 (Mollusca: Bivalvia)

    Science.gov (United States)

    Lutikov, O. A.; Temkin, I. E.; Shurygin, B. N.

    2010-08-01

    We described ontogenies and reconstructed morphogeneses of hinges in some supraspecific taxa of the bivalve family Oxytomidae Ichikawa, 1958 from the Mesozoic of Russia. The phylogeny of the family is reconstructed using evolutionary and cladistic methods. The appearance of the endemic genus Arctotis Bodylevsky, 1960 in the epicontinental seas of Siberia can be explained in terms of gradual transformations of the ligament and byssal apparatus in the Northern Siberian members of Praemeleagrinella Lutikov et Shurygin, 2009 and Praearctotis Lutikov et Shurygin, 2009.

  11. Cytogenetics of Anodonta cygnea (Mollusca: Bivalvia) as possible indicator of environmental adversity

    Science.gov (United States)

    Carrilho, J.; Leitão, A.; Vicente, C.; Malheiro, I.

    2008-11-01

    Anodonta cygnea is a freshwater clam, belonging to the Unionidae family, which can be found in rivers and lagoons all over Europe and Northern America. As they appear as important case studies for ecological damage assessments, the various species of the Unionidae family have been submitted to a sort of recent studies on their chromosomal or cytogenetic status. In this study we confirmed the diploid chromosome number of 2 n = 38 for this species, and established for the first time the karyotype, which comprised six metacentric, 12 submetacentric and one subtelocentric chromosome pairs. We also found a high percentage of cells with an abnormal number of chromosomes. Considering that karyotype disturbances in Unionids have been previously related with exposure to chemicals, either natural or produced by human activity, we determined the aneuploidy index for our population. The aneuploidy index is an excellent marker for pollutant presence/effect. The animals acclimatized in tap water and in natural water from the lake where the individuals were collected showed different levels of aneuploidy. The higher values were found in tap water. Chromosome analysis techniques seem a suitable tool to study the impact of contaminants referred above, and making A. cygnea a suitable organism for assessment of an eugenic damage in aquatic systems. On the other hand, our results also point out to the importance of doing the acclimatizing process of the collected animals in their own natural water.

  12. Multi-species generalist predation on the stochastic harvested clam Tivela mactroides (Mollusca, Bivalvia)

    Science.gov (United States)

    Turra, Alexander; Fernandez, Wellington S.; Bessa, Eduardo; Santos, Flavia B.; Denadai, Márcia R.

    2015-12-01

    Top-down control is an important force modulating the abundance of prey and structuring marine communities. The harvested trigonal clam Tivela mactroides is hypothesized to be part of the diet of a variety of marine organisms, with its stock influencing predator abundance and being influenced by them. Here we analyzed the diet of potential predators of T. mactroides in Caraguatatuba Bay, northern coast of São Paulo State, Brazil, to identify the main consumers of this marine resource, and also to address the importance of this clam in the diet of each predator. Samples were taken year-round by trawls; all specimens collected were identified and measured and the food items identified and quantified. Twenty-one species consumed T. mactroides, whose importance in the diet varied greatly in both the volume ingested and the frequency of occurrence (pompano Trachinotus carolinus > blue crab Callinectes danae > starfish Astropecten marginatus). Top-down influence on T. mactroides was also dependent on the abundance of consumers (yellow catfish Cathorops spixii > rake stardrum Stellifer rastrifer > barred grunt Conodon nobilis > A. marginatus). Considering the mean volume ingested, the frequency of occurrence of T. mactroides in the diet, and the relative abundance of consumers, the predators that most influenced T. mactroides were T. carolinus, A. marginatus, and C. danae, in decreasing order. Large numbers of small-sized individuals of T. mactroides (<10 mm) were generally preyed upon by A. marginatus, which may have a stronger effect on clam abundance in comparison to C. danae and T. carolinus, which preyed upon larger clams. In conclusion, the results of this study indicate that predators' consumption of T. mactroides in Caraguatatuba Bay can influence its stocks, mainly due to the type and/or abundance of predator species, the volume and number of individuals of T. mactroides preyed upon, and the temporal variations in the abundance of predators.

  13. Systematic reviews on the Mesodesmatidae (Mollusca, Bivalvia) I. The Genus Monterosatus Beu, 1971

    NARCIS (Netherlands)

    Rooij-Schuiling, de L.A.

    1977-01-01

    In trying to identify a small Mesodesma from West Irian, New Guinea, much material in the collections of several museums was studied. As a guide for the identification I at first used the revision of the Mesodesmatidae by Lamy (1914), which is based exclusively on the collections of the Parisian mus

  14. On the identity of broad-shelled mussels (Mollusca, Bivalvia, Mytilus) from the Dutch delta region

    NARCIS (Netherlands)

    Groenenberg, D.S.J.; Wesselingh, F.P.; Rajagopal, S.; Jansen, J.M.; Bos, M.M.; Velde, van der G.; Gittenberger, E.; Hoeksema, B.W.; Raad, H.; Hummel, H.

    2011-01-01

    Late Quaternary (Eemian) deposits of the Netherlands contain shells that resemble those of living Mytilus galloprovincialis. Similar broad-shelled mytilids also occur in estuaries of the southwestern Netherlands together with slender individuals typical of M. edulis. We sampled living mussels along

  15. Thyasira ockelmanni (Mollusca: Bivalvia: Veneroidea, A new species of Thyasiridae from the Norwegian Sea

    Directory of Open Access Journals (Sweden)

    Rozemarijn Keuning

    2010-12-01

    Full Text Available 800x600 Normal 0 21 false false false NO-BOK X-NONE X-NONE MicrosoftInternetExplorer4 A new species of Thyasiridae, Thyasira ockelmanni n.sp. is described from the abyssal depths of the Norwegian Sea. The generic assignment is tentative and possible alternatives are discussed. The new species has some resemblance to Thyasira subovata (Jeffreys, 1881 and Adontorhina similis Barry & McCormack, 2007, but the posterior outline is rounded and not angulate or truncate as in these species.

  16. Sinanodonta woodiana (Mollusca: Bivalvia: Unionidae: Isolation and Characterization of the First Microsatellite Markers

    Directory of Open Access Journals (Sweden)

    Elena Iulia Iorgu

    2011-08-01

    Full Text Available Sinanodonta woodiana (Lea, 1834 is a large Unionid species with a real invasion success. It colonized Europe, Central America, the Indonesian Islands and recently North America. The species life cycle involves a larval parasitic stage on freshwater fish species which contributes to the spread of the mussel. In this paper we describe, for the first time, eight polymorphic microsatellite loci for the species Sinanodonta woodiana. The genetic screening of individuals confirmed that all loci were highly polymorphic. The number of alleles per locus ranged from 7 to 14 and the observed heterozygosity ranged from 0.650 to 0.950. These loci should prove useful to study the species population genetics which could help to infer important aspects of the invasion process.

  17. Toxicological aspects associated with the ecology of Donax trunculus (Bivalvia, Mollusca) in a polluted environment

    Energy Technology Data Exchange (ETDEWEB)

    Fishelson, L.; Manelis, R. [Department of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv (Israel); Bresler, V.; Zuk-Rimon, Z.; Dotan, A.; Yawetz, A. [Institute for Nature Conservation Research, Faculty of Life Sciences, Tel Aviv University, Tel Aviv (Israel); Hornung, H. [Israel Oceanographic and Limnological Research, National Institute of Oceanography, Haifa (Israel)

    1999-02-09

    This study provides data on the ecology and toxicology observed in the population of Donax trunculus, a sand dwelling mussel, in the shallow subtidal of Haifa Bay (Mediterranean Sea, Israel). The studied population of the mussel forms a dominant fraction in a community of sand-dwelling molluscs in a zone located 5-25 m from the shoreline, and at depths of 20-120 cm, numbering up to 2000 per m{sup 2}. Samples of the mussel were collected from three sites, located within 9 km of shore in Haifa Bay. These included a clean site (Akko), a site polluted by a chemical PVC-polymer industry (Frutarom), and a site polluted with oil and waste from the petrochemical industry (Qiryat Yam). Metal analysis indicated site-dependent variations in levels of cadmium, lead, copper and mercury in the mussel soft tissues. Copper levels were similar in the bivalves collected from all the sites. Levels of mercury were significantly higher in specimens from the PVC-polluted site (Frutarom) while levels of cadmium were higher in Akko and Qiryat Yam compared to Frutarom. Lead residues were found only in Donax from Akko. The residual contents of mercury, copper and cadmium were relatively high in the young and noticeably low in Donax of medium body size. The main site of deposition of metals was in the soft tissues of the bivalve, but bioaccumulation of metals was also found in the shells. A marked increase in permeability of gills and mantle to the fluorescent anionic dye-fluorescein (FLU) was detected in Donax from Qiryat Yam and especially Frutarom, compared to the bivalves sampled from Akko. Multiple foci of enhanced permeability (multiple fluorescent spots) were detected in all the individuals sampled from Frutarom but none in the bivalve samples from Akko. Lysosomal accumulation of the metachromatic fluorescent cationic probe, acridine orange - (AO), was significantly decreased in the tissues of D. trunculus from polluted sites, especially polluted by the PVC factory. This decrease correlated with lysosomal enlargement and the formation of secondary lysosomes. D. trunculus appears to possess the most effective biochemical and physiological defense mechanisms enabling it to survive in habitats of polluted shallow waters, where other sand dwelling mollusc species were absent or found only in waters deeper then 2.5 m. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  18. The aquatic molluscs (Mollusca: Gastropoda and Bivalvia of Vrachanski Balkan Nature Park

    Directory of Open Access Journals (Sweden)

    DILIAN GEORGIEV

    2016-05-01

    Full Text Available Till now 13 species of aquatic molluscs are known to inhabit the park area: 11 species of snails and 2 species of clams. Even included in the list the species of Grossuana and Radix balthica has to be studied anatomically for sure identification. Nine species are of conservation statute classified as "Least Concern" or "Vulnerable", and four does not have any statute. Three stygobiotic snail species are local endemics.

  19. The Recent Pectinoidea of the New Zealand region (Mollusca: Bivalvia: Propeamussiidae, Pectinidae and Spondylidae)

    NARCIS (Netherlands)

    H.H. Dijkstra; B.A. Marshall

    2008-01-01

    The Recent Pectinoidea of the New Zealand region are reviewed. Eight new species are described from the New Zealand Exclusive Economic Zone: Parvamussium cancellorum, Cyclochlamys austrina, Cc. delli, Cc. irregularis, Cc. munida, Cc. pileolus, Cyclopecten fluctuosus, and Catillopecten tasmani. Nine

  20. The anatomy and functional morphology of Diplodon rhombeus fontainianus (Orbigny, 1835 (Mollusca Bivalvia, Hyriidae

    Directory of Open Access Journals (Sweden)

    WEP. Avelar

    Full Text Available Diplodon rhombeus fontainianus (Orbigny, 1835, belongs to the family Hyriidae Swainson 1840, the distribution of which is restricted to South America and Australasia. This species, endemic to Brazil, occurs in the central-southern geographical region, Upper Paraná Basin and Atlantic Microbasins Espirito Santo to Paraná states. The mollusk lives buried in muddy substrata, has similar sized adductor muscles, and is dioecious, lacking sexual dimorphism. The apertures are simple (type AII of Yonge, 1948, 1957 as in Diplodon rotundus gratus, Castalia undosa martensi, Castalia undosa undosa and mantle fusion is present only in the base of the exalant aperture. The inhalant aperture exhibits tentacles originating from the inner fold while the exhalant aperture has no tentacles. The ctenidia are type D (of Atkins, 1937. A well-developed marsupium is present in the inner demibranch. The association between the ctenidia and the labial palps belongs to category I (of Stasek, 1963. The stomach constitutes a type IV structure (of Purchon, 1958. The posterior sorting area (psa presents two pouches in Diplodon rhombeus fontainianus. Among the Hyriidae, the presence of these pouches has also been described in several species of Hyriidae from South America. The organization of the gut in the visceral mass follows the same pattern seen in the Hyriidae already studied: Castalia undosa martensi, Castalia undosa undosa, Diplodon.rotundus gratus,Diplodon charruanus and Diplodon pilsbryi.

  1. Pectinoidea (Mollusca, Bivalvia, Propeamussiidae, Cyclochlamydidae n. fam., Entoliidae and Pectinidae) from the Vanuatu Archipelago

    NARCIS (Netherlands)

    Dijkstra, H.H.; Maestrati, P.

    2012-01-01

    This paper documents the species of Pectinoidea Rafinesque, 1815 collected in Vanuatu during the SANTO 2006 expedition. A total of 49 species (13 Propeamussiidae Abbott, 1954, 4 Cyclochlamydidae n. fam., 1 Entoliidae Teppner, 1922, and 31 Pectinidae Rafinesque, 1815) are represented, of which 70% ar

  2. Systematic reviews on the Mesodesmatidae (Mollusca, Bivalvia) I. The Genus Monterosatus Beu, 1971

    NARCIS (Netherlands)

    Rooij-Schuiling, de L.A.

    1977-01-01

    In trying to identify a small Mesodesma from West Irian, New Guinea, much material in the collections of several museums was studied. As a guide for the identification I at first used the revision of the Mesodesmatidae by Lamy (1914), which is based exclusively on the collections of the Parisian mus

  3. Immunological and biochemical responses in Mya arenaria (Mollusca Bivalvia) exposed in vivo to estradiol-17beta.

    Science.gov (United States)

    Gauthier-Clerc, S; Pellerin, J; Fournier, M; Amiard, J-C

    2006-11-01

    Soft-shell clams Mya arenaria were injected with 10, 20 or 40 nmol of estradiol 17beta (E2). We observed a significant inhibiting effect of E2 on phagocytic activity of hemocytes from clams exposed to 10 and 20 nmol. A dose-response increase of the glycogen phosphorylase in the gonad tended to show a remobilisation of glycogen reserves involved in vitellogenesis although the exposure time must have been too short to observe a decrease in glycogen reserves or an increase in RNA concentration. Both results corroborate those of other studies about estrogen involvement in controlling immune capacity and energy metabolism related to vitellogenesis in bivalves. We can assume that immune parameters should now be taken into consideration in assessing endocrine disruption in bivalves. Nevertheless further studies are needed to understand the controlling pathways of E2 with a special regard on its interactions with other effectors involved in bivalve immunity and reproduction as well.

  4. Reproductive Features of Indigenous and the Invasive Chinese Freshwater Mussels (Mollusca, Bivalvia, Anodontinae in Ukraine

    Directory of Open Access Journals (Sweden)

    Yanovych L. M.

    2015-10-01

    Full Text Available Процессы размножения аборигенных видов беззубок из водоемов и водотоков Украины протекают неполноценно. Среди Anodonta anatinа (Linnaeus, 1758 примерно только в 60 % пунктов сбора размножаются 100 % самок, в остальных пунктах «беременными» оказываются лишь 17-90 % самок, у A. cygnea (Linnaeus, 1758 - 50 % самок. Примерно в 70 % пунктов сбора самки A. cygnea и Pseudanodonta complanata Rossmassler, 1835 имеют не полностью (от . до . заполненные половыми продуктами марсупии. Зато вид-вселенец китайская беззубка, Sinanodonta woodiana (Lea, 1834, имеет многократные кладки в течение всего года. Полужабры половыми продуктами заполнены полностью.

  5. Temporal dynamics of amino and fatty acid composition in the razor clam Ensis siliqua (Mollusca: Bivalvia)

    Science.gov (United States)

    Baptista, Miguel; Repolho, Tiago; Maulvault, Ana Luísa; Lopes, Vanessa M.; Narciso, Luis; Marques, António; Bandarra, Narcisa; Rosa, Rui

    2014-12-01

    Few studies have been conducted on the temporal dynamics of both amino acid (AA) and fatty acid (FA) profiles in marine bivalves. We investigated the seasonal variation of these compounds in the pod razor clam Ensis siliqua in relation to food availability, salinity, water temperature and reproductive cycle. AA content varied between 46.94 and 54.67 % dry weight (DW), and the AAs found in greater quantity were glutamic acid, glycine and aspartic acid. FA content varied between 34.02 and 87.94 mg g-1 DW and the FAs found in greater quantity were 16:0 and 22:6 n-3. Seasonal trends were observed for AAs and FAs. FAs increased with gametogenesis and decreased with spawning while AA content increased throughout spawning. The effect of increasing temperature and high food availability during the spawning season masked the loss of AAs resulting from gamete release. Still, a comparatively greater increase in the contents of glutamic acid and leucine with spawning indicate their possible involvement in a post-spawning gonad recovery mechanism. A post-spawning decrease in 14:0, 16:0, 16:1 n-7, 18:1 n-7 and 18:1 n-9 is indicative of the importance of these FAs in bivalve eggs. An increase in 18:3 n-3, 18:4 n-3, 20:1 n-9 and 20:2 n-6 during gametogenesis suggests their involvement in oocyte maturation. The FA 22:4 n-6, while increasing with spawning, appears to play a role in post-spawning gonad recovery. Salinity did not have an effect on the AA composition. None of the environmental parameters measured had an effect on FA composition.

  6. Reproductive cycle of Glycymeris nummaria (Mollusca: Bivalvia from Mali Ston Bay, Adriatic Sea, Croatia

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    Marija Crnčević

    2013-06-01

    Full Text Available The reproductive cycle of the dog cockle, Glycymeris nummaria (Glycymerididae, was studied using specimens collected monthly from Mali Ston Bay, southeastern Adriatic Sea over the period from January to December 2010. We analysed sex ratios, gonad developmental stages, and oocyte diameters using standard histological techniques. There were no differences in the overall sex ratio and no difference in shell length with respect to sex. Results of a size-frequency analysis of oocyte diameters agreed with a qualitative analysis of gonadal developmental stages, confirming the occurrence of one annual spawning peak from May to July. A significant correlation was identified between mean gonad indices of males and females and condition index. This study provides the first data on the reproductive characteristics of G. nummaria, providing necessary information for the future sustainable management of its potential fishery.

  7. Body condition and gametogenic cycle of Galatea paradoxa (Mollusca: Bivalvia) in the Volta River estuary, Ghana

    Science.gov (United States)

    Adjei-Boateng, D.; Wilson, J. G.

    2013-11-01

    The reproductive cycle of Galatea paradoxa which is the basis for an artisanal fishery in the Volta River estuary, Ghana, was studied using condition indices and histological methods from March 2008 to July 2009. The cycle is annual with a single spawning event between June and October. Gametogenesis starts in November progressing steadily to a peak in June-July when spawning begins until October when the animal is spent. The condition indices (shell-free wet weight/total wet weight, ash-free dry weight/shell weight and gonad wet weight/shell weight) showed a clear relationship with the gametogenic stage rising from a minimum at stage (I) start of gametogenesis, to their highest values at stages (IIIA) ripe and (IIIB) start of spawning before declining significantly to stage (IV) spent.It is suggested that condition index may prove a valuable technique in fishery management to recognise the reproductive stages of G. paradoxa as it is less expensive and time consuming than histological techniques in addition to being easier to teach to non-specialists. The data presented in this study provide information on the timing of spawning events for G. paradoxa, which is necessary for developing sustainable management strategies and selection of broodstock for aquaculture.

  8. New insights into diversity and evolution of deep-sea Mytilidae (Mollusca: Bivalvia).

    Science.gov (United States)

    Lorion, Julien; Buge, Barbara; Cruaud, Corinne; Samadi, Sarah

    2010-10-01

    Bathymodiolinae mussels have been used as a biological model to better understand the evolutionary origin of faunas associated with deep-sea hydrothermal vents and cold seeps. Most studies to date, however, have sampled with a strong bias towards vent and seep species, mainly because of a lack of knowledge of closely related species from organic falls. Here we reassess the species diversity of deep-sea mussels using two genes and a large taxon sample from the South-Western Pacific. This new taxonomic framework serves as a basis for a phylogenetic investigation of their evolutionary history. We first highlight an unexpected allopatric pattern and suggest that mussels usually reported from organic falls are in fact poorly specialized with regard to their environment. This challenges the adaptive scenarios proposed to explain the diversification of the group. Second, we confirm that deep-sea mussels arose from organic falls and then colonized hydrothermal vents and cold seeps in multiple events. Overall, this study constitutes a new basis for further phylogenetic investigations and a global systematic revision of deep-sea mussels. Copyright 2010 Elsevier Inc. All rights reserved.

  9. Taxonomy of some Galeommatoidea (Mollusca, Bivalvia associated with deep-sea echinoids

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    Graham Oliver

    2012-04-01

    Full Text Available The type species of Axinodon ellipticus Verrill & Bush, 1898 and Kellia symmetros Jeffreys, 1876 are re-described. It is concluded that the two species are not conspecific and that K. symmetros cannot be placed in the genus Axinodon. The family affinity of Axinodon is not resolved, although it is probable that this genus belongs to the Thyasiridae. Kellia symmetros is the type species of Kelliola and is placed in the Montacutidae. Kelliola symmetros is most probably associated with the echinoid Aeropsis rostrata and is not the species previously recorded from North Atlantic Pourtalesia echinoids under the name of Axinodon symmetros. This commensal associated with the North Atlantic Pourtalesia is here described as new and placed in the new genus as Syssitomya pourtalesium gen. nov. sp. nov., Syssitomya gen. nov. differs from all other genera in the Montacutidae by having laminar gill filaments modified for harbouring symbiotic bacteria and it is thus assumed to be chemosymbiotic. A montacutid associated with the hadal Pourtalesia heptneri is described as Ptilomyax hadalis gen. nov. sp. nov.

  10. Redescription of Hiatella meridionalis d'Orbigny, 1846 (Mollusca, Bivalvia, Hiatellidae from Argentina

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    Luiz Ricardo L. Simone

    2008-01-01

    Full Text Available The redescription of Hiatella meridionalis (d’Orbigny, 1846 is provided as first attempt to improve the systematics of the genus in the regions of Atlantic and western Pacific. This reanalysis is based on specimens collected in the vicinity of the type localities and is based on detailed morphology of samples that some researches consider a single, wide ranging species. From the morphological characters, the more interesting are: a high quantity of papillae at incurrent siphon; the retractor muscles of siphon divided in two bundles; the small size of the palps; the muscular ring in the stomach; and the zigzag fashion of the short intestinal loops. These characters distinguish the species from the other hiatellids so far examined. Type material of the species was examined, by first time illustrated, and the lectotype is designated.A redescrição de Hiatella meridionalis (d’Orbigny, 1846 é realizada como primeiro passo na melhoria da sistemática do gênero das regiões atlântica e pacífica oeste. Esta re-análise é baseada em espécimes coletados nas vizinhanças da localidade tipo e em morfologia detalhada de amostras que alguns pesquisadores consideram pertencer a uma única espécie de ampla distribuição. Dos caracteres anatômicos, os mais interessantes são: uma grande quantidade de papilas no sifão inalante; o músculo retrator dos sifões dividido em duas porções; o tamanho pequeno dos palpos; um anel muscular transversal no estomago; e um padrão em zigzag no curto intestino. Estes caracteres distinguem a espécie dos demais hiatelídeos até então examinados. Os sintipos da espécie foram também examinados e pela primeira vez ilustrados; o lectótipo é designado.

  11. The effect of temperature and body size on filtration rates of Limnoperna fortunei (Bivalvia, Mytilidae under laboratory conditions

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    Débora Pestana

    2009-02-01

    Full Text Available The golden mussel (Limnoperna fortunei, Mollusca: Bivalvia is an invasive species that has been causing considerable environmental and economic problems in South America. In the present study, filtration rates of L. fortunei were determined in the laboratory under different temperatures (10, 15, 20, 25, 28, and 30 ºC and two types of food (Algamac-2000® and the chlorophycean alga Scenedesmus sp.. There was a statistically significant relationship between time and filtration rates in the experiment using Scenedesmus sp., regardless of temperature. However, this pattern was absent in the experiment using Algamac, suggesting that the relationship between filtration rates and temperature might depend on the size of the filtered particles. In addition, there was no correlation between filtration rates and either shell size or condition index (the relationship between the weight and the length of a mussel. The filtration rate measured in the present study (724.94 ml/h was one of the highest rates recorded among invasive bivalves to date. Given that the colonies of the golden mussel could reach hundreds of thousands of individuals per square meter, such filtration levels could severely impact the freshwater environments in its introduced range.

  12. De weekdieren van de Nederlandse brakwatergebieden (Mollusca)

    NARCIS (Netherlands)

    Kuijper, W.J.

    2000-01-01

    The molluscs of the brackish waters in the Netherlands (Mollusca) The Netherlands is a river delta rich in brackish waters. The organisms in these waters need to be adapted to extreme conditions, especially large fluctuations in chlorinity. However, several species occur optimally in this habitat. I

  13. Investigation of the Diversity of Mollusca and Evaluation of Water Quality in Hengyang Reach of Xiangjiang River%湘江衡阳段软体动物多样性调查和水质生物学评价

    Institute of Scientific and Technical Information of China (English)

    刘俊; 吴彦琼; 李静; 胡劲松; 李鹏; 刘运莲

    2011-01-01

    The species and diversity and faunal and distribution of molluscas in Hengyang reach of Xiangjiang River were studied after many years of dayuandu hydropower station built; and in virtue of diversity indexes of molluscas, water quality were evaluated. The result of the research showed that there were 45 species of mollusca in Hengyang reaches of Xiang River, which belong to 2 classes and 9 families and 18 genera. 30 species belonging to 11 genera in 6 families of Gastropoda were found, 15 specieses belonging to 7 genera in 3 families of Bivalvia were found. The mollusca was in Oriental realm. 26 species were endemic species in China, and Mekonia hunanensis was in endangered status (It has been listed in China Species Red List as an extinct species). Shannon index was used to evaluate water quality of Hengyang reaches of Xiang River. The result showed that the water quality in Dongzhou ialand and Hengshan county town belonged to clean water, the other 8 sampling sites water had been polluted slightly.%对衡山大源渡电站蓄水多年后的湘江衡阳段软体动物的种类组成、区系分布以及多样性进行了调查,并用生物多样性指数对湘江衡阳段水质进行了评价.调查结果表明,湘江衡阳段计有软体动物45种,分别隶属于2纲9科18属,其中腹足纲6科11属30种,双壳纲3科7属15种,其区系成分主要为东洋界类型;其中26种为中国特有种,且湖南湄公螺为濒危物种(被定为灭绝的物种).用软体动物的Shannon-Wiener多样性指数(H')对湘江衡阳段进行水质生物学评价,研究结果表明,湘江衡阳段的水质除东洲岛和衡山县城为清洁水外,其余8个采样点的水质均受到了轻度污染.

  14. Gloquídio de Diplodon martensi (lhering (Mollusca, Bivalvia, Hyriidae e seu ciclo parasitário The glochidium of Diplodon martensi (lhering (Mollusca, Bivalvia, Hyriidae and its parasitic cycle

    Directory of Open Access Journals (Sweden)

    Maria Cristina Dreher Mansur

    1999-01-01

    Full Text Available Conchological and anatomical studies of the glochidium of Diplodon martensi (lhering, 1893 were performed on samples collected in a small river, tributary from the Caí River, that belong to the Jacuí River sub-basin in south-eastern Brazil. The parasitic development of the glochidium was observed in laboratory on a small cichlid fish Gymnogeophagus gymnogenys (Hensel, 1870.

  15. The interference of methods in the collection of teredinids (Mollusca, Bivalvia in mangrove habitats Interferência de métodos na coleta de teredinídios (Mollusca, Bivalvia em habitats de manguezais

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    Rosa M. V. Leonel

    2006-03-01

    Full Text Available In the estuary of the Mamanguape River (Paraíba, Brazil, a new collection technique was developed and applied with virgin poles of mangrove trees Avicennia schaueriana (Verbenaceae, Rhizophora mangle (Rhizophoraceae, and Laguncularia racemosa (Combretaceae, taking into account wood preference, water salinity and depth influence during teredinid larval settlement. Sets of poles were vertically fixed in the riverbed at three sites along a decreasing salinity gradient, where they stayed for four months. The poles were collected and divided into upper, median, and lower segments, in agreement with different immersion regimes. An increase of 239% was obtained in the number of individuals when compared to a previous study in the same area using a different methodology. The species Teredo bartschi (Clapp, 1923, Nausitora fusticula (Jeffreys, 1860 and Bankia fimbriatula Moll & Roch, 1931 were registered in both studies, and the species Psiloteredo healdi (Bartsch, 1931 is here registered for the first time as occurring in that estuary. The species Neoteredo reynei (Bartsch, 1920, previously registered on tree branches of the mangrove habitat, was not found in the present work. Bankia fimbriatula, the most abundant species, did not show preference for any substratum but occurred significantly on the lower segment of the poles. N. fusticula, second in abundance, preferred to settle on poles of A. schaueriana and on any of the three segments. Aiming to assess the habitat variations, a more accurate study on teredinids diversity in mangrove ecosystems should be performed through a concomitant analysis from tree branches of the mangrove habitat, as well as from poles of mangrove trees or panels made of pine wood or mangrove trees wood. These collection devices should be maintained along a decreasing salinity gradient exposed to different tide levels.Contemplando a preferência pelo tipo de madeira, a influência da profundidade e da salinidade durante assentamento larval de teredinídeos, uma nova técnica de coleta foi aplicada e desenvolvida no estuário do rio Mamanguape (Paraíba, Brasil, utilizando varas virgens de três espécies de árvores do manguezal: Avicennia schaueriana (Verbenaceae, Rhizophora mangle (Rhizophoraceae e Laguncularia racemosa (Combretaceae. Em três estações demarcadas ao longo do gradiente decrescente de salinidade, conjuntos de varas foram verticalmente fixados nas margens do rio. Após quatro meses, as varas eram coletadas e divididas em três segmentos (superior, médio e inferior, de acordo com os regimes de imersão a que foram submetidas. Comparativamente aos dados obtidos por um estudo anterior na mesma área, com outras metodologias de coleta, foi obtido um aumento de 239% no número de indivíduos coletados com a nova técnica. Embora as espécies Teredo bartschi (Clapp, 1923, Nausitora fusticula (Jeffreys, 1860 e Bankia fimbriatula Moll & Roch, 1931 tenham ocorrido nos dois estudos, o teredinídeo Psiloteredo healdi (Bartsch, 1931 tem sua presença registrada pela primeira vez neste estuário. Tendo sido previamente registrada em ramos de árvores do manguezal, Neoteredo reynei (Bartsch, 1920 não foi coletada no presente trabalho. Sendo a espécie mais abundante, B. fimbriatula não mostrou preferência de assentamento em nenhum dos substratos, ocorrendo significativamente associada ao segmento inferior das varas. Como segunda espécie mais abundante, N. fusticula mostrou preferência significativa de assentamento em A. schaueriana, ocorrendo indistintamente nos três segmentos das varas. Visando contemplar as variações do habitat e obter maior precisão de resultados, é recomendável que em estudos sobre a diversidade de teredinídeos, sejam incluídas análises concomitantes de troncos e ramos das árvores, com o uso de varas de árvores do manguezal ou de coletores artificiais feitos com pinho ou madeira de árvores do manguezal. Os coletores devem ser mantidos ao longo do gradiente de salinidade e expostos aos diferentes níveis das marés.

  16. Polidorídeos (Polychaeta: spionidae) em Crassostrea rhizophorae (Mollusca: bivalvia) de cinco rios da costa pernambucana

    OpenAIRE

    Henrique de Oliveira Bonifácio, Paulo

    2009-01-01

    A ostra Crassostrea rhizophorae ocorre ao longo da costa do Brasil servindo como alimento para comunidades litorâneas e sua produção ajuda no desenvolvimento sócio-econômico local. Polidiariose é uma das diversas doenças presentes em ostreiculturas do mundo. É causada por poliquetas da família Spionidae que perfuram a concha e habitam uma bolha de lodo no interior da ostra, causando perda de valor comercial considerável. Oito gêneros de espionídeos podem ser responsáveis por...

  17. Anatomy and systematics of Anodontites Elongatus (Swainson from Amazon and Parana Basins, Brazil (Mollusca, Bivalvia, Unionoida, Mycetopodidae

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    Luiz Ricardo L Simone

    1997-12-01

    Full Text Available The anatomy of Anodontiies elongatus (Swainson, 1823, a rare species restricted to the Amazon and Parana Basins, is described by first time, showing a group of conchological and anatomical characters exclusive of this species that may be analyzed to identify it. Diagnosis of A. elongatus: shell long antero-posteriorly, umbones prominent, periostracum opaque and smooth, two posterior radial striae; middle fold of mantle edge veiy tall; gill long antero-posteriorly and short dorso-ventrally, extending about a half of it total length beyond visceral mass; palps proportionally small, several furrows in its outer surface; stomach without esophageal transversal ridjp, dorsal hood and gastric shield poorly developed, major typhlosole entering in ddd , posterior pouch of sa³ very-long; style sac reduced, without crystalline style; distal region of intestine and rectum with a well developed typhlosole, "T" in section, other intestinal regions without folds; gonad gonochoristic.

  18. Differences in the rDNA-bearing chromosome divide the Asian-Pacific and Atlantic species of Crassostrea (Bivalvia, Mollusca).

    Science.gov (United States)

    Wang, Yongping; Xu, Zhe; Guo, Ximing

    2004-02-01

    Karyotype and chromosomal location of the major ribosomal RNA genes (rDNA) were studied using fluorescence in situ hybridization (FISH) in five species of CRASSOSTREA: three Asian-Pacific species (C. gigas, C. plicatula, and C. ariakensis) and two Atlantic species (C. virginica and C. rhizophorae). FISH probes were made by PCR amplification of the intergenic transcribed spacer between the 18S and 5.8S rRNA genes, and labeled with digoxigenin-11-dUTP. All five species had a haploid number of 10 chromosomes. The Atlantic species had 1-2 submetacentric chromosomes, while the three Pacific species had none. FISH with metaphase chromosomes detected a single telomeric locus for rDNA in all five species without any variation. In all three Pacific species, rDNA was located on the long arm of Chromosome 10 (10q)--the smallest chromosome. In the two Atlantic species, rDNA was located on the short arm of Chromosome 2 (2p)--the second longest chromosome. A review of other studies reveals the same distribution of NOR sites (putative rDNA loci) in three other species: on 10q in C. sikamea and C. angulata from the Pacific Ocean and on 2p in C. gasar from the western Atlantic. All data support the conclusion that differences in size and shape of the rDNA-bearing chromosome represent a major divide between Asian-Pacific and Atlantic species of CRASSOSTREA: This finding suggests that chromosomal divergence can occur under seemingly conserved karyotypes and may play a role in reproductive isolation and speciation.

  19. [Abundance and morphometry of tuberculosa Anadara and A. similis (Mollusca: Bivalvia) in the Manglar de Purruja, Dulce Gulf, Costa Rica].

    Science.gov (United States)

    Silva Benavides, A M; Bonilla Carrión, R

    2001-12-01

    The density, population, length, yield and sex proportion of the mollusks Anadara tuberculosa and A. similis were studied in Bahía de Golfito, Golfo Dulce, Pacific coast of Costa Rica from February 1998 to February 1999. A. tuberculosa was more abundant (0.9 units m(-2)), than A. similis (0.2 units m(-2)); the highest abundance was found at the canal mouths. The average lengths were 43.3 mm for A. tuberculosa and 42.8 mm for A. similis (both under the Costa Rican legal minimal length for exploitation: 47 mm). Maximum lengths were measured in the middle and upstream Canal Mayor, respectively: 43.0 mm and 43.4 mm. The correlation between length and fresh weight was 0.81 (Pearson). The average total weights were 26.2 g for A. tuberculosa and 19.1 g for A. similis. The condition index (a meat yield measurement) was higher in A. similis (21.2%) than in A. tuberculosa (17.2%). The maximum yield for both species lies in the 31-35 mm range. The male ratio was 43.7%. A species recovery plan is urgent because these results suggest both a decrease in density and illegal exploitation.

  20. Evidence for accumulation of Synechococcus elongatus (Cyanobacteria: Cyanophyceae) in the tissues of the oyster Crassostrea gigas (Mollusca: Bivalvia).

    Science.gov (United States)

    Avila-Poveda, Omar Hernando; Torres-Ariño, Alejandra; Girón-Cruz, Diego Ademir; Cuevas-Aguirre, Angel

    2014-10-01

    Cyanobacteria appear to have direct relations with mollusks in several aspects. This is the first time, distinguishing Gram-negative cyanoprokaryotic Synechococcus elongatus as bright yellow-gold autofluorescence by Lillie's and Hiss' staining methods on paraffin-embedded tissues of Crassostrea gigas. Three diets: cyanoprokaryotes, cyanoprokaryotes with microalgae, and only microalgae were evaluated. Cyanoprokaryotes were intact, densely bundled, and immersed in the cytosol of the digestive gland, connective tissue, mantle, and gonad of C. gigas, revealing an accumulation systemic without tissue damage observed by histology. Unexpectedly, cyanoprokaryotes were slightly most accumulated with microalgae diet by each of the tissues of the C. gigas than with any other diets. Cyanoprokaryotes tend to be in mean slightly higher in the digestive gland than in any other tissues respectively for each diet, although these values are closely similar to connective tissue. A possible order of exposure of the oyster tissues to accumulation of cyanoprokaryotes was digestive gland, connective tissue, mantle, and gonad. Thereby, the digestive gland could be the major target tissue for the accumulation. Our observations provide a valuable insight regarding the ability of cyanoprokaryotes to penetrate, spread, and remain inside the oyster tissues, suggesting for S. elongatus: (1) a pre-accumulation in oyster tissues from the natural environment, (2) a phagocytosis and/or endocytosis process rather than ingestion and extracellular digestion, (3) an apparent cellular division in the cytosol of oyster tissues, (4) an apparent inter-tissue movement, and (5) a possible endosymbiosis between C. gigas and S. elongatus. Hereby, it is possible that S. elongatus have a well-developed host-endobiont relationship with oysters, and thereby support future work toward a description of the escape and spreading mechanisms of S. elongatus inside the tissues of mollusks, and put forward questions as why it is there? and are the cells active or inactive?

  1. Immunochemical localization of ribulose-1,5-bisphosphate carboxylase in the symbiont-containing gills of Solemya velum (Bivalvia : Mollusca)

    NARCIS (Netherlands)

    Cavanaugh, Colleen M.; Abbott, Marilyn S.; Veenhuis, Marten

    1988-01-01

    The distribution of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase (RbuP2Case; EC 4.1.1.39) was examined by using two immunological methods in tissues of Solemya velum, an Atlantic coast bivalve containing putative chemoautotrophic symbionts. Antibodies elicited by the purified large

  2. A new genus and species of Thyasiridae (Mollusca, Bivalvia from deep-water, Beaufort Sea, northern Alaska

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    Paul Valentich-Scott

    2014-12-01

    Full Text Available Bivalve mollusk shells were collected in 2350 m depth in the Beaufort Sea, Arctic Ocean off northern Alaska. Initial identification suggested the specimens were a member of the bivalve family Thyasiridae, but no known eastern Pacific or Arctic living or fossil thyasirid resembled these deep-water specimens. Comparisons were made with the type of the genera Maorithyas Fleming, 1950, Spinaxinus Oliver & Holmes, 2006, Axinus Sowerby, 1821, and Parathyasira Iredale, 1930. We determined the Beaufort Sea species represents a new genus, herein described as Wallerconcha. These specimens also represent a new species, herein named Wallerconcha sarae. These new taxa are compared with known modern and fossil genera and species of thyasirds.

  3. Differences in absolute and relative growth between two shell forms of Pinna nobilis (Mollusca: Bivalvia) along the Tunisian coastline

    Science.gov (United States)

    Rabaoui, Lotfi; Tlig-Zouari, Sabiha; Katsanevakis, Stelios; Belgacem, Walid; Hassine, Oum Kalthoum Ben

    2011-08-01

    This study investigated the absolute and relative growth patterns of the fan mussel Pinna nobilis along the Tunisian coastline, taking into consideration both the variability among different areas and between the two shell forms "combed" and "straight and wide". Five subpopulations of the species were sampled, one from northern, two from eastern and two from southern Tunisia. Various assumptions on the growth patterns were tested based on an information theory approach and multi-model inference. For absolute growth, the assumption of different growth patterns between the two shell forms of P. nobilis and no difference among subpopulations was the most supported by the data. For the same age, "straight and wide" individuals gained on average greater lengths than the "combed" individuals. The absolute growth of the species was found to be asymptotic and the logistic model was the one most supported by the data. As for the relative growth, apart from the classical allometric model Y = aXb, more complicated models of the form ln Y = f(ln X) that either assumed non-linearities or breakpoints were tested in combination with assumptions for possible differences between the two forms and among subpopulations. Among the eight studied relationships between morphometric characters, the classical allometric model was supported in only two cases, while in all other cases more complicated models were supported. Moreover, the assumption of different growth patterns between the two forms was supported in three cases and the assumption of different growth patterns among subpopulations in four cases. Although precise relationships between the morphometric plasticity of the fan mussel and environmental factors have not been proven in this paper, local small scale constraints might be responsible of the different growth patterns observed in the same locality. A possible co-action of genetic factors should be evaluated in the future.

  4. Mytilus antiquorum J. Sowerby, 1821 and other Pliocene mussels (Mollusca, Bivalvia) from the Southern North Sea Basin

    NARCIS (Netherlands)

    Vervoenen, M.; Wesselingh, F.P.; Nieulande, van F.A.D.

    2000-01-01

    Mytilus antiquorum J. Sowerby, 1821, is recorded from the Coralline Crag Formation of East Anglia (UK) and the Lillo Formation (Oorderen, Kruisschans and Merksem members) of the Antwerp area (Belgium). The species is diagnosed on the basis of newly collected material and differentiated from modern E

  5. Integrative study of a new cold-seep mussel (Mollusca: Bivalvia) associated with chemosynthetic symbionts in the Marmara Sea

    Science.gov (United States)

    Ritt, Bénédicte; Duperron, Sébastien; Lorion, Julien; Sara Lazar, Cassandre; Sarrazin, Jozée

    2012-09-01

    Recently, small Idas-like mussels have been discovered living on carbonate crusts associated with cold-seeps in the Marmara Sea. These mussels, here referred to as Idas-like nov. sp., differ morphologically and genetically from another species identified as Idas aff. modiolaeformis, living in the same type of ecosystem in the Nile Deep-Sea Fan (eastern Mediterranean Sea). A phylogenetic analysis confirms the distinction between the two species, which belong to highly divergent lineages. Carbon stable isotope values, as well as the detection of thiotroph-related bacteria in the gill tissue, support the presence of a symbiotic, thiotroph-derived nutrition. In contrast, Idas aff. modiolaeformis displays six different types of symbionts. Finally our size-frequency data suggest that the recruitment is continuous in the examined area. The present study extends the documented distribution of symbiont-bearing mussels to the Marmara Sea, and contributes to the characterisation of biological communities in this recently explored area.

  6. Effect of zinc and benzene on respiration and excretion of mussel larvae (Perna perna (Linnaeus, 1758 (Mollusca; Bivalvia

    Directory of Open Access Journals (Sweden)

    RADLVC. Jorge

    Full Text Available The presence of pollutants in the ocean may affect different physiological parameters of animals. Oxygen consumption and ammonia excretion were evaluated in D-shaped larvae of mussels (Perna perna exposed to zinc sulphate (ZnSO4 and benzene (C6H6. When compared to the control group, both pollutants presented a significant reduction in oxygen consumption. A reduction in the ammonia excretion was also observed, both for ZnSO4 and C6H6 and also in the oxygen consumption. The results indicate that anaerobic metabolism may occur at the beginning of P. perna mussels development, as observed in veliger larvae. The O:N ratio under experimental conditions showed low values indicating that catabolism in veliger larvae was predominantly proteic.

  7. Bivalvia (Mollusca) of Nansha Islands, China%中国南沙群岛的双壳纲贝类

    Institute of Scientific and Technical Information of China (English)

    蔡英亚; 刘桂茂

    2004-01-01

    报道了中国南沙群岛的双壳纲贝类141种,分隶于5亚纲8目36科77属.从种类的组成中,帘蛤科有18种,蚶科15种,扇贝科11种,鸟蛤科10种,锉蛤科8种,贻贝科、海菊蛤科和樱蛤科各7种,砗磲科6种,其他各科的种类均在5种以内.按种的性质而论,大多数属于和珊瑚礁有密切联系的热带种或亚热带种,区系性质为印度-西太平洋区的印尼-马来亚区.

  8. Deep-water Thyasiridae (Mollusca: Bivalvia) from the Oman Margin, Arabian Sea, new species and examples of endemism and cosmopolitanism.

    Science.gov (United States)

    Oliver, P Graham

    2015-08-05

    Seven species of Thyasiridae are reported from the Oman Margin of the Arabian Sea at depths between 688 m and 3356 m. Hypoxic conditions exist at depths between 400 and 1200 m and three species are restricted to this zone and to the Arabian Sea. Leptaxinus indusarium has also been recorded from the Indus Fan and Channelaxinus investigatoris from off Sri Lanka. A new species Thyasira anassa sp. nov. is described from the hypoxic zone. Another four species are recorded from the abyssal zone where oxygen levels are typical for the deep ocean. Here another new species is described, Parathyasira bamberi sp. nov. but the other species could not be conclusively identified because of close affinity with populations from other oceans.  Deep water Atlantic species Axinulus croulinensis and Mendicula ferruginosa are apparently present in the abyssal Indian Ocean while another thyasirid shell is very close to Channelaxinus excavatus from the Eastern Pacific and C. perplicata from the Atlantic. Accompanying these abyssal thyasirids were other bivalve species, Deminucula atacellana, Limopsis pelagica and Bentharca asperula that cannot be distinguished by morphology from their Atlantic populations. It is concluded that using morphology alone that the abyssal species may well be cosmopolitan in distribution.

  9. A new species of Pulvinites (Mollusca: Bivalvia) from the upper Paleocene Paspotansa Member of the Aquia Formation in Virginia ( USA).

    Science.gov (United States)

    Ward, L.W.; Waller, T.R.

    1988-01-01

    Pulvinites lawrencei n.sp. is described from the upper Paleocene (Landenian Stage) Paspotansa Member of the Aquia Formation in Stafford County, Virginia. This is the first report of a member of the pteriacean family Pulvinitidae in the Tertiary on either side of the Atlantic, the only other post-Mesozoic records of Pulvinites being in the Paleocene of California and the present-day Pacific off southeast Australia. The stratigraphic setting and co-occurring molluscan assemblage of the new species indicate shallow-shelf, open-marine conditions with near normal salinities. -Authors

  10. Cytogenetic characterisation of the razor shells Ensis directus (Conrad, 1843) and E. minor (Chenu, 1843) (Mollusca: Bivalvia)

    Science.gov (United States)

    González-Tizón, Ana M.; Rojo, Verónica; Vierna, Joaquín; Jensen, K. Thomas; Egea, Emilie; Martínez-Lage, Andrés

    2013-03-01

    The European razor shell Ensis minor (Chenu 1843) and the American E. directus (Conrad 1843) have a diploid chromosome number of 38 and remarkable differences in their karyotypes: E. minor has four metacentric, one metacentric-submetacentric, five submetacentric, one subtelocentric and eight telocentric chromosome pairs, whereas E. directus has three metacentric, two metacentric-submetacentric, six submetacentric, six subtelocentric and two telocentric pairs. Fluorescent in situ hybridisation (FISH) using a major ribosomal DNA probe located the major ribosomal genes on one submetacentric chromosome pair in both species; FISH with a 5S ribosomal DNA (5S rDNA) probe rendered one chromosomal (weak) signal for E. minor and no signal for E. directus, supporting a more dispersed organisation of 5S rDNA compared to the major ribosomal genes. The vertebrate telomeric sequence (TTAGGG) n was located on both ends of each chromosome, and no interstitial signals were detected. In this work, a comparative karyological analysis was also performed between the four Ensis species analysed revealing that the three European species studied so far, namely E. minor, E. siliqua (Linné 1758) and E. magnus Schumacher 1817 show more similarities among them than compared to the American species E. directus. In addition, clear karyotype differences were found between the morphologically similar species E. minor and E. siliqua.

  11. Numerical Quantification of Perkinsus Marinus in the American Oyster Crassostrea virginicata (Gmelin 1791) (Mollusca: Bivalvia) by Modern Stereology

    Science.gov (United States)

    Species of Perkinsus are responsible for high mortalities of bivalve molluscs world-wide. Techniques to accurately estimate parasites in tissues are required to improve understanding of perkinsosis. This study quantifies the number and tissue distribution of Perkinsus marinus in ...

  12. Life cycle, population dynamics, growth and production of Abra segmentum (Mollusca, Bivalvia) at low salinities in a Mediterranean lagoon

    Science.gov (United States)

    Kevrekidis, Theodoros; Kasapis, K.; Kalpia, V.

    2009-12-01

    Aspects of the biology of Abra segmentum were investigated at low salinities in a Mediterranean coastal lagoon (Monolimni Lagoon, Northern Aegean Sea). Monthly samples were collected during the period from February 1998 to January 1999. Recruitment occurred from mid-spring to early autumn (0.3-5.7 psu) and recruits grew during summer and autumn (1.2-5.7 psu), while a major part vanished during next autumn, displaying a maximum life span of about 20 months. A positive correlation was found between the percentage of individuals having a shell length of ≤3.5 mm and temperature; age group 0 showed a growth rate of 0.97 mm per month, and the largest individual collected had a 19.76 mm shell length. The population density sharply increased during late spring (0.3-1.2 psu); this increase was followed by a decline during summer and, afterwards, a gradual increase up to late autumn. Secondary production calculated by the size-frequency method gave a mean annual density ( n) of 3,357 individuals m-2, a mean annual biomass ( B) of 21.98 g DW m-2, an annual production ( P) of 73.72 g DW m-2 and a P: B ratio of 3.35. A comparison of the present data with available data of A. segmentum populations from higher salinity habitats revealed that this bivalve in the study area showed a life history pattern similar to that of other populations of the species and a comparatively high growth rate, maximum body size, n, B, P and P: B ratio. Our findings suggest that the studied aspects of A. segmentum biology could not be markedly affected by low salinities.

  13. Recrutamento larval e crescimento de teredinidae (mollusca-bivalvia em região entremarés de manguezais

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    Sônia Godoy Bueno Carvalho Lopes

    1997-01-01

    Full Text Available O recrutamento larval e o crescimento de Teredinidae na região entremarés do manguezal da Praia Dura, Ubatuba, SP, foi acompanhado durante doze meses (08/84 a 08/85 utilizando coletores construídos com madeira de mangue. O tempo decorrido para se detectar a presença dos primeiros Teredinidae foi de aproximadamente sete meses após o início do experimento e o número de indivíduos por coletor foi muito reduzido no período de amostragem. Esses resultados contrastam com os obtidos por outros autores que instalaram coletores em ambiente marinho, mas são semelhantes aos obtidos por autores que instalaram coletores em regiões estuarinas do litoral brasileiro. Essas diferenças nos resultados talvez possam ser explicadas pelo fato da salinidade ser mais baixa e mais variável nos estuários que no ambiente marinho. A análise dos dados sobre o recrutamento larval, permite concluir que a espécie mais abundante foi Nausitora fustieula (Jeffreys, 1860, com principal época de instalação em março e taxa inicial de crescimento de 1,86 mm/day. As outras espécies de Teredinidae, Bankiaflmbriatula Moll & Roch, 1931, Bankia roehi Moll, 1931 e Neoteredo reynei (Bartsch, 1920, apresentaram pequeno número de indivíduos e em função disso, não foi possível determinar suas épocas de instalação e respectivas taxas de crescimento.The larval settlement and growth of Teredinidae in the intertidal region of the Praia Dura mangrove, Ubatuba, SP, were undertaken during one year (08/84 to 08/85 using colectors made from mangrove wood. The presence of the first Teredinidae was detected approximately seven month after the inicial experiment and the number of specimens per coletor was small during the sampling period. These results contrast with those obtained by other authors working in a marine environment, but are similar to those obtained in experiments developed in Brazilian estuaries. The differences between data obtained in marine and estuarine environments, might be explained by the lower and more variable salinity gradient in estuaries. Larval settlement data revealed that the most abundant species was Nausitora fustieula (Jeffreys,1860, which settles on wood prefrerably in March, and has an initial growth rate of 1.86 mm/day. The other Teredinidae species Banida fimbriatula Moll & Roch, 1931, Bankia rochi Moll, 1931 and Neoteredo reynei (Bartsch, 1920, occurred in a very small number of specimens and therefore, their time of settlement and growth rates could not be determined.

  14. New lucinid bivalves from shallow and deeper water of the Indian and West Pacific Oceans (Mollusca, Bivalvia, Lucinidae

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    John Taylor

    2013-08-01

    Full Text Available Four new species and a new genus of lucinid bivalves are described from shallow and deeper waters in the Indian and West Pacific Oceans. The new genus Scabrilucina (subfamily Lucininae includes the little-known S. victorialis (Melvill, 1899 from the Arabian Sea and S. vitrea (Deshayes, 1844 from the Andaman Sea as well as a new species S. melvilli from the Torres Strait off northeastern Australia. Ferrocina brunei new species (Lucininae was recovered from 60 m near oil drilling activities off Borneo; its anatomy confirmed the presence of symbiotic bacteria. Two unusual deeper water species of Leucosphaerinae are described, both species included in on-going molecular analyses; Gonimyrtea ferruginea from 400–650 m in the southwest Pacific and Myrtina reflexa from 200–825 m off Zanzibar and Madagascar.

  15. 栉江珧生殖细胞的发生%Gametogenesis in Atria pectinata Linnaeus (Mollusca, Bivalvia)

    Institute of Scientific and Technical Information of China (English)

    王梅芳; 余祥勇; 王如才

    2000-01-01

    通过观察栉江珧(Atrina pectinata linnaeus)的未分化生殖细胞,精原细胞和卵原细胞,精母细胞和卵母细胞,精子和卵子的形态结构与分布状况及核仁在卵成熟过程中的变化,对栉江珧生殖细胞发生及成熟过程的有关问题进行了探讨.

  16. Cryptic species of deep-sea clams (Mollusca: Bivalvia: Vesicomyidae) from hydrothermal vent and cold-water seep environments

    Science.gov (United States)

    Vrijenhoek, Robert C.; Schutz, Steven J.; Gustafson, Richard G.; Lutz, Richard A.

    1994-08-01

    A protein-electrophoretic analysis of six putative morphospecies in the bivalve family Vesicomyidae from eight deep-sea hydrothermal vent sites in the eastern Pacific, three cold-water seep sites in the eastern Pacific and the Gulf of Mexico, and one whale-carcass site off Southern California revealed electromorph patterns diagnostic of 10 vesicomyid species. Electrophoretic patterns for 14 enzymes encoded by 17 presumptive gene loci were scored in all 10 species. The pairwise genetic distances (Nei's D) for these 10 species ranged from 0.857 to 2.792, values within the range expected for distinct species and genera. However, the degree of genetic divergence among these taxa could not be used for phylogenetic inferences because allozyme differences had in many cases reached evolutionary saturation. Notwithstanding, the present results revealed a significant problem with current morphospecies identifications of these clams and with applications of the current generic names Calyptogena and Vesicomya. Given the cryptic nature of these taxa, we suggest that subsequent studies simply refer to these clams as "vesicomyids" until careful morphological analyses and molecular studies are completed and systematic relationships are clarified.

  17. Comparative studies on the histology and ultrastructure of the siphons of two species of Tellinidae (Mollusca: Bivalvia from Brazil

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    João E.V.V. Vitonis

    2012-06-01

    Full Text Available Despite the great importance of the siphons for infaunal bivalves, only a few studies have examined their tissues using histology techniques or scanning electron microscopy. In the present study, the siphons of Tellina lineata Turton, 1819 and Macoma biota Arruda & Domaneschi, 2005 were investigated. The siphon walls are composed by a series of muscle sheets of longitudinal ("L", circular ("C" and radial ("R" fibers, with a clear pattern common to both species: there is a main median longitudinal layer (Lm, and two peripheral circular layers, one inner (Ci and one outer (Co, near the epithelia. A median circular layer (Cm separates an internal (Lmi from an outer (Lmo median longitudinal layer. Further, the Co is split by a thin outer longitudinal layer (Lo, forming Coi and Coo layers, the former being obliquely oriented. Thin radial fibers (R delimit clear packages of Lmi and Lmo fibers. In each siphon, there are six longitudinal nerve cords, running within the Lmi layer, adjacent to the Cm. The inhalant and exhalant siphons of M. biota are very similar in structure, but the Lmo of the exhalant siphon is almost twice as thick as its Lmi, while in the inhalant siphon these layers have similar thicknesses; the Coi is very thick, especially in the exhalant siphon. The inhalant siphon of T. lineata is very similar to that of M. biota, differing only with respect to the thickness of the Coi, which in the former species is not as well developed as in the latter. The Lmo of the exhalant siphon of T. lineata is by far the most developed layer, with the Lmi represented only by uniseriate small cells; in the vicinities of the nerve cords, the Cm is split in two layers. The epithelia of both siphons of M. biota and T. lineata bear ciliated receptors, which were difficult to observe as they were frequently covered with mucus. It was possible to observe that cilia are present in both species, differing in length and in the number per receptor between the inhalant and exhalant siphons, and between the species. Detailed comparisons among the siphons of M. biota and T. lineata and other bivalve species are very difficult, because of at least two reasons. First, each investigator has used different methods to prepare and observe the siphons through histological sections; and second, different nomenclatural schemes are used to describe the musculature of the siphons, causing confusion when the same layers are compared among different species. In order to unify the nomenclature of tissue layers of the bivalve siphons, we now propose a scheme to name these layers based on topological homology.

  18. Differences in the distribution and abundance of Teredinidae (Mollusca: Bivalvia along the coast of Rio de Janeiro state, Brazil

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    Gustavo Carvalho Maldonado

    Full Text Available Abstract Teredinidae are wood-boring mollusks found in marine and estuarine regions. Evaluation of the distribution and abundance of Teredinidae is a very important task, as the impact of the destruction of wood in man-made structures is still underestimated, mainly in tropical regions. It is also know that temperature and salinity are key factors affecting the abundance and activity of Teredinidae due to their effects on the physiological responses of Teredinidae. The aim of this study was to evaluate the distribution and abundance of Teredinidae along the Rio de Janeiro coast according to temperature range and pattern. Artificial pine collectors were used and remained immersed for three months in four regions at 14 sites. We recorded seven species of Teredinidae, identified according to their pallets. Ilha Grande Bay was the region with the highest density and species richness, and the region with the lowest was Guanabara Bay. One gradient of abundance related to temperature was found. The most abundant species were Lyrodus floridanus and Teredo furcifera. Besides temperature, wood availability among regions was another important factor. For the first time, we recorded the occurrence of Bankia destructa on the Rio de Janeiro coast, but this record does not indicate any species introduction or expanding distribution range.

  19. Effects of anthracene on filtration rates, antioxidant defense system, and redox proteomics in the Mediterranean clam Ruditapes decussatus (Mollusca: Bivalvia).

    Science.gov (United States)

    Sellami, Badreddine; Khazri, Abdelhafidh; Louati, Héla; Dellali, Mohamed; Driss, Mouhamed Ridha; Aïssa, Patricia; Mahmoudi, Ezzeddine; Hamouda, Beyrem; Coelho, Ana Varela; Sheehan, David

    2015-07-01

    This study aimed at analyzing the impact of a toxic polyaromatic hydrocarbon (PAH), anthracene (ANT), on Ruditapes decussatus collected from a Tunisian coastal lagoon (Bizerte Lagoon). Filtration rates, several antioxidant enzymes--superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione transferase (GST)--as well as indices of protein oxidation status were determined in various tissues of this bivalve. Specimens were exposed to 100 μg/L of ANT for 2 days. ANT levels were evaluated using HPLC and were detected in the gill and digestive gland at different amounts. ANT exposure altered the behavior of bivalves by changing the siphon movement and decreasing filtration rate significantly. The enzymatic results indicated that ANT exposure affected the oxidative stress status of the gills of R. decussatus. In addition, modification of proteins was detected in the gills using redox proteomics after ANT treatment. Three protein spots were successfully identified by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF-MS). These proteins can be roughly related to muscle contraction function. In contrast, no significant modification of enzymatic and protein responses was detected in the digestive gland after ANT treatment. These data demonstrate that combined behavioral and biochemical analyses are a powerful tool to provide valuable insights into possible mechanisms of toxicity of anthracene in R. decussatus. Additionally, the results highlight the potential of the gill as a valuable candidate for investigating PAH toxicity.

  20. Associated fauna of the fan shell Pinna nobilis (Mollusca: Bivalvia in the northern and eastern Tunisian coasts

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    Lotfi Rabaoui

    2009-03-01

    Full Text Available Epifaunal communities associated with the fan shell Pinna nobilis Linnaeus, 1758 along the Tunisian coastline were investigated. Both univariate and multivariate analysis were done at different spatial scales within five populations located at different localities, three from northern and two from eastern Tunisia. The size of Pinna did not appear as the main factor affecting the structure of the associated biota, which seemed to be more influenced by (a marine-lagoon and (b biogeographic gradients. Patterns of similarity of sessile sclerobionts and motile epifauna were clearly different. The former assemblage best replied to lagoon-sea gradient and to locality, with three real clusters at 40%, whereas the latter assemblage scattered widely in a non-metrical MDS plane, with two real clusters only at 20% similarity. The spatial turnover of motile species was ten times higher than that of sessile species at a small spatial scale, being less affected by Pinna size, and three times higher though invariant at a large geographic scale. On the other hand, β-diversity of sessile species appeared to be more influenced by latitudinal (climatic gradient at a large scale, being higher in the northern than in the eastern communities. Analysis of taxonomic (dissimilarity of the whole community detected these two sources of environmental (lagoon-sea gradient and biogeographic (lati-longitudinal gradient variation, although each phylum showed its peculiar pattern. In terms of Dajoz’s constancy index the majority of associated communities were dominated by rare species, and within the majority of epifaunal assemblages, the most abundant sessile epizoobiont was a bivalve mollusc. The sessile epifauna was dominated by active filterers, which led to a possible existence of trophic competition between the host and the sedentary epizoites, since both basibionts and sclerobionts occupy the same trophic niche. The fan shell played an important ecological role, providing new hard substrate to colonise, increasing the spatial heterogeneity for the surrounding soft-bottom communities, and contributing to the overall increase of the local biotope complexity level.

  1. Effect of heavy metals (Cu, Cd and Pb) on aspartate and alanine aminotransferase in Ruditapes philippinarum (Mollusca: Bivalvia)

    Energy Technology Data Exchange (ETDEWEB)

    Blasco, J.; Puppo, J. [Instituto de Ciencias Marinas de Andalucia, Campus Univ. Rio S. Pedro, 11510 Puerto Real, Cadiz (Spain)

    1999-02-01

    The accumulation of cadmium, copper and lead and their effects on aspartate and alanine aminotransferases in digestive gland, gills, foot and soft body in the clam Ruditapes philippinarum were examined. The animals were exposed to different concentrations: Cd (200-600 {mu}g{center_dot}l{sup -1}), Pb (350-700 {mu}g{center_dot}l{sup -1}) and Cu (10-20 {mu}g{center_dot}l{sup -1}) for 7 days. The highest concentrations were found in digestive gland for cadmium and copper, and in gills for lead, and the lowest values were observed in the foot. Aspartate aminotransferase activity (AST), in general, was not inhibited by cadmium, lead or copper during the exposure. Only in clams exposed to cadmium (600 {mu}g{center_dot}l{sup -1}, 7 days) and copper (20 {mu}g{center_dot}l{sup -1}, 5 days) were observed significant differences (P<0.05) in foot and gills, respectively, with respect to control. In the case of alanine aminotransferase activity (ALT), significant differences were observed for cadmium and lead in treated animals with respect to control. With regard to copper, a decrease in ALT was observed in gills and foot exposed to 20 {mu}g{center_dot}l{sup -1}. A significant correlation (P<0.05) was observed between ALT and metal accumulation for cadmium, copper and lead in gills. In the case of soft body, only cadmium and lead showed a significant correlation. In summary, R. philippinarum can be considered a bioindicator species for cadmium and lead accumulation and ALT could be useful as biomarker of sublethal stress for these metals in soft tissues and gills. Only gills can be considered an adequate target tissue for copper. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  2. Isolation and Characterization of the First Microsatellite Markers for the Endangered Relict Mussel Hypanis colorata (Mollusca: Bivalvia: Cardiidae

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    Luis Ovidiu Popa

    2011-01-01

    Full Text Available Hypanis colorata (Eichwald, 1829 (Cardiidae: Lymnocardiinae is a bivalve relict species with a Ponto-Caspian distribution and is under strict protection in Romania, according to national regulations. While the species is depressed in the western Black Sea lagoons from Romania and Ukraine, it is also a successful invader in the middle Dniepr and Volga regions. Establishing a conservation strategy for this species or studying its invasion process requires knowledge about the genetic structure of the species populations. We have isolated and characterized nine polymorphic microsatellite markers in H. colorata. The number of alleles per locus ranged from 4 to 28 and the observed heterozygosity ranged from 0.613 to 1.000. The microsatellites developed in the present study are highly polymorphic and they should be useful for the assessment of genetic variation within this species.

  3. The Effects of Mercury Exposure on the Surface Morphology of Gill Filaments in Perna perna (Mollusca: Bivalvia)

    Energy Technology Data Exchange (ETDEWEB)

    Gregory, M.A.; George, R.C.; Marshall, D.J.; Anandraj, A.; McClurg, T.P

    1999-01-01

    This study investigated the possibility that changes in the surface morphology of mussel (Perna perna) gill filaments may be used to indicate the relative toxicity of pollutants in the marine environment. Healthy, adult P. perna were collected and immersed in 2 free-flow tanks. Mercury was added to seawater as it entered tank 1 to achieve a constant level of 50 {mu}g/l{sup -1} over 24 days. Uncontaminated seawater was circulated over the mussels in tank 2 (control) for the same period. A 25 mm{sup 2} area of gill filament was removed from each of the 5 specimens before and after 24 days immersion in tank 2, and after immersion for 1, 2, 4, 8, 16 and 24 days in tank 1. These were examined using a scanning electron microscope. The remaining soft tissues from each animal were analysed for mercury using an atomic absorption spectrometer. Mercury concentration increased from 0.13 (pre-immersion) to 87 {mu}g/g after day 24. Surface morphology remained normal for all animals in tank 2 and for those exposed to Hg for up to 8 days. However, from 16 to 24 days exposure there was a gradual increase in the diameters of microvilli, a depletion of abfrontal cilia, an increase in abnormal, perhaps necrotic cells and an unusual increase in the number of cilia on the lateral surfaces. These results confirm that P. perna is an efficient bio-accumulator and suggest that their gill pathomorphology may be a useful indicator of toxicity.

  4. Relationship between element concentrations and body size in the Lake Maggiore population of Unio pictorum mancus (Mollusca, Bivalvia

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    Ilenia CATTANI

    2011-08-01

    Full Text Available The study focused on using a fresh-water mussel (Unio pictorum mancus as a bioindicator of various pollutants, and particularly metals. The elements considered were: Al, As, Ca, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V and Zn. This research was carried out at a site where various other studies have been conducted on important characteristics of the same population of Unio. This site is a small bay called "Sabbie d’Oro" located on the south-east coast of Lake Maggiore. Our study involved quantifying the capacity of this mollusc to concentrate large amounts of metal in its body without evident consequences by using detoxification mechanisms. We analysed not only element concentrations, but also their variability (expressed as CV% in the soft tissues and in the shell, for two main reasons: i the sampling design should include a preliminary analysis to determine how many specimens is necessary collect to ensure a specified level of precision; ii the sample variability value may be combined with the value of analytical precision (BCR to obtain an estimate of the "experimental" precision. In soft tissue, Ca accumulation tended to increase with size, and Al accumulation decreased with size. In shell, Ca and Ni were stored more than in soft tissue, but not proportionally to size. V, Cr and Mo tended to accumulate in the shell progressively over the years, whereas Co and Al are "diluted" during growth, or are absorbed mainly during the juvenile stage. Partition between shell and soft tissue resulted roughly the same in the juvenile and adult stages for the following elements: Fe, Al, Co, As, Pb. The relationships among the various elements were schematized in a hierarchical tree plot.

  5. Estradiol-17beta and testosterone concentrations in male and female Mya arenaria (Mollusca bivalvia) during the reproductive cycle.

    Science.gov (United States)

    Gauthier-Clerc, S; Pellerin, J; Amiard, J C

    2006-01-15

    Perturbation of the reproductive cycle as well as vitellin-like protein synthesis have already been reported in Mya arenaria sampled in contaminated areas of the St. Lawrence maritime estuary (Québec, Canada). To assess the potential role of endocrine disruptors in modulating the reproductive cycle in clams, the role of sex steroids has to be clarified. We determined the levels of estradiol-17beta and testosterone during the reproductive cycle in female and male M. arenaria. Both steroids were measured by ELISA in the gonads and no differences in steroid profiles appeared between sexes. Estrogen levels varied between 150 and 400 pg g(-1) wet weight over gametogenesis and were near 10 times higher than testosterone levels. Results showed transient increases of both steroids at the onset of vitellogenesis in females and during the spawning stage in both sexes. These findings indicate that these hormones could have a role as endogenous modulators of gametogenesis. Further studies are, however, needed to describe the pathway of steroid synthesis in clam gonad and elucidate steroid involvement in controlling gametogenesis and as well as their relationship with neurohormones since these latter are required to promote sexual maturation.

  6. Free amino acids in the clam Macoma balthica (L.) (Bivalvia, Mollusca) from brackish waters of southern Baltic Sea

    NARCIS (Netherlands)

    Sokolowski, A.; Wolowicz, M.; Hummel, H.

    2003-01-01

    Fourteen acidic and neutral free amino acids (FAA) were investigated in soft tissue of Macoma balthica from different depth zones of the Gulf of Gdansk (Baltic Sea) over a full seasonal cycle. The dry weight of the bivalves and physico-chemical parameters of overlying bottom water and surface

  7. Reproductive cycle of Anomalocardia brasiliana (Mollusca: Bivalvia: Veneridae) in the estuary of the Cachoeira River, Ilhéus, Bahia.

    Science.gov (United States)

    Luz, J R; Boehs, G

    2011-08-01

    The aim of this study was to characterize the reproductive cycle of Anomalocardia brasiliana, typical of the estuarine region of the Cachoeira River, Ilhéus, Bahia, Brazil. For this purpose, 20 specimens were collected biweekly between August 2005 and August 2006 on an intertidal bank (14º 48' 23" S and 39º 02' 47" W). The animals were measured on the anteroposterior axis (length), examined macroscopically and removed from the shell and fixed in Davidson's solution. Subsequently, the tissues were impregnated in paraffin, cut into 7 mm sections and stained with Harris hematoxylin and eosin (HE). The slides were examined under a light microscope. The water temperature at the site ranged from 24 to 30.5 ºC (mean: 27.4 ºC; SD ± 1.9), salinity from zero to 23 (mean: 13.7; SD ± 7.5) and rainfall from 28.3 mm to 248.8 mm monthly (yearly mean: 130 mm). The sample (n = 478) showed a sex ratio (M: F) of 1: 1.2 (p reproductive synchrony. The reproductive cycle was continuous, with releases of gametes mainly in spring, summer and autumn. These results are similar to those found in other regions, but there was no reproductive rest period as reported for populations in higher latitudes.

  8. Comparative study of gonadal development of Ruditapes philippinarum (Adams and Reeve and Ruditapes decussatus (L. (Mollusca: Bivalvia: Influence of temperature

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    Marina Delgado

    2007-09-01

    Full Text Available Laboratory experiments were used to study the influence of temperature on the reproductive behaviour of two species of clam, Ruditapes decussatus and Ruditapes philippinarum, during their adaptation to the temperature conditions of Galician coastal waters. In both species the rate of gonadal development was directly related to the increase in temperature. At 14°C the reproductive behaviour was similar, both species needing over 2 months to mature. At 18°C, the rate of gonadal development of R. philippinarum was greater than that of R. decussatus. Nevertheless, the results of this study confirm that both species have adapted perfectly to the temperature conditions of the Galician Rias, though certain differences between the reproductive behaviour of these species were detected. R. philippinarum accumulates oocytes prior to their partial or total emission, while in the case of R. decussatus gametes are liberated continuously. In the early phases of its development, the gonad of R. philippinarum is highly heterogeneous in nature, with up to 3 reproductive states being present at the same time, while in R. decussatus gonadal development is much more uniform. Another major difference concerns the phenomenon of reabsorption, common in R. philippinarum but very rare in R. decussatus. These characteristics may well result in a greater reproductive activity in R. philippinarum than in R. decussatus, and a longer reproduction period in the former. They may also represent a certain advantage for the adaptation of the foreign species (R. philippinarum over the native species (R. decussatus to the temperature conditions of the Galician Rias.

  9. Immunohistochemical localization of serotonin (5-hydroxytryptamine) in the gonad and digestive gland of Mya arenaria (Mollusca: Bivalvia).

    Science.gov (United States)

    Garnerot, F; Pellerin, J; Blaise, C; Mathieu, M

    2006-12-01

    Serotonin (5-hydroxytryptamine or 5-HT) C(10)H(12)N(2)O plays a central role in several physiological processes in marine molluscs, especially in reproduction. 5-HT acts as a neurohormone to modulate spawning, parturition and meiosis by reinitiating prophase in arrested oocytes. Preliminary experiments using 10(-5)M 5-HT dissolved in aquarium water showed that 5-HT induced spawning movements in ripe clams and in both sexes of Mya arenaria while only a few males released sperm. The occurrence of serotoninergic fibers was demonstrated by PAP immunohistochemical reaction in the gonad of both sexes during gametogenesis. In an organism infected by the trematode parasite Prosorhynchus squamatus, we showed that serotoninergic innervation completely disappeared around the gonad's follicles. Although the gonad and digestive gland are intertwined, no serotoninergic innervations were found in the digestive gland. These findings suggest, for the first time to our knowledge in the soft shell clam, that serotonin might be involved in the regulation of gametogenesis.

  10. Reproductive cycle of Tagelus plebeius (Mollusca: Bivalvia in the estuary of the Cachoeira River, Ilhéus, Bahia, Brazil

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    LO. Ceuta

    Full Text Available This study characterized the reproductive cycle of the stout razor clam Tagelus plebeius in the estuary of the Cachoeira River, Ilhéus, Bahia, northeastern Brazil. Samples of 20 animals per collection were taken biweekly from August 2005 to August 2006. The 480 specimens were measured on the antero-posterior axis (length and then removed from the shell. After macroscopic analysis, the gonads were fixed in Davidson's solution, processed by routine histology and stained by Harris hematoxylin and eosin. The gonads of both males and females appeared milky white, without sexual dimorphism. Microscopic analyses indicated a M: F ratio of 1.06: 1 and continuous reproduction of T. plebeius in the region. The period from August to October showed the most intense spawning. This study provides another example of continuous reproduction of bivalves in tropical waters, and because this species is a heavily exploited fishery resource in the region, it draws attention to the need for a management plan aimed at reducing harvests.

  11. Reproductive cycle of Tagelus plebeius (Mollusca: Bivalvia) in the estuary of the Cachoeira River, Ilhéus, Bahia, Brazil.

    Science.gov (United States)

    Ceuta, L O; Boehs, G

    2012-08-01

    This study characterized the reproductive cycle of the stout razor clam Tagelus plebeius in the estuary of the Cachoeira River, Ilhéus, Bahia, northeastern Brazil. Samples of 20 animals per collection were taken biweekly from August 2005 to August 2006. The 480 specimens were measured on the antero-posterior axis (length) and then removed from the shell. After macroscopic analysis, the gonads were fixed in Davidson's solution, processed by routine histology and stained by Harris hematoxylin and eosin. The gonads of both males and females appeared milky white, without sexual dimorphism. Microscopic analyses indicated a M: F ratio of 1.06: 1 and continuous reproduction of T. plebeius in the region. The period from August to October showed the most intense spawning. This study provides another example of continuous reproduction of bivalves in tropical waters, and because this species is a heavily exploited fishery resource in the region, it draws attention to the need for a management plan aimed at reducing harvests.

  12. Multi-locus fossil-calibrated phylogeny, biogeography and a subgeneric revision of the Margaritiferidae (Mollusca: Bivalvia: Unionoida).

    Science.gov (United States)

    Bolotov, Ivan N; Vikhrev, Ilya V; Bespalaya, Yulia V; Gofarov, Mikhail Y; Kondakov, Alexander V; Konopleva, Ekaterina S; Bolotov, Nikita N; Lyubas, Artyom A

    2016-10-01

    The taxonomy and biogeographic history of the bivalve family Margaritiferidae are controversial because previous molecular studies did not provide a well-resolved phylogenetic framework for these enigmatic freshwater mussels that have extensive but disjunct distribution in North America, Eurasia and North Africa. In this study, we present a new, fossil-calibrated phylogenetic hypothesis based on five molecular markers (∼4kb of total length) for ten species. Our results indicate that all recent margaritiferids are in the single genus, Margaritifera Schumacher, 1816. Additionally, we identified three relatively well-supported phylogenetic clades that are valid subgenera, i.e., Margaritifera s. str. (Holarctic), Margaritanopsis (=Cumberlandia) (southeast North America-southeast Asia disjunct) and Pseudunio (Mediterranean). We suggest that the crown lineage of the Margaritiferidae most likely originated in the Cretaceous (mean age 93Ma, 95% CI 66-126Ma). The combined results of ancestral area reconstructions based on the three different approaches (S-DIVA, DEC and S-DEC) showed that ancient vicariance events could have played an important role in speciation within the family. The rates of mitochondrial evolution of margaritiferids are notably slow, which may be associated with their longevity, long generation time and low metabolic rates. Our findings highlight the complex biogeographic history of the Margaritiferidae as an intermixing of ancient vicariance and dispersal events, which were most likely associated with some inland barriers, continental movements and a sea level dynamic.

  13. DNA barcoding and phylogenetic analysis of Pectinidae (Mollusca: Bivalvia) based on mitochondrial COI and 16S rRNA genes.

    Science.gov (United States)

    Feng, Yanwei; Li, Qi; Kong, Lingfeng; Zheng, Xiaodong

    2011-01-01

    DNA sequence data enable not only the inference of phylogenetic relationships but also provide an efficient method for species-level identifications under the terms DNA barcoding or DNA taxonomy. In this study, we have sequenced partial sequences of mitochondrial COI and 16S rRNA genes from 63 specimens of 8 species of Pectinidae to assess whether DNA barcodes can efficiently distinguish these species. Sequences from homologous regions of four other species of this family were gathered from GenBank. Comparisons of within and between species levels of sequence divergence showed that genetic variation between species exceeds variation within species. When using neighbour-joining clustering based on COI and 16S genes, all species fell into reciprocally monophyletic clades with high bootstrap values. These evidenced that these scallop species can be efficiently identified by DNA barcoding. Evolutionary relationships of Pectinidae were also examined using the two mitochondrial genes. The results are almost consistent with Waller's classification, which was proposed on the basis of shell microstructure and the morphological characteristics of juveniles.

  14. First molecular phylogeny of the circumtropical bivalve family Pinnidae (Mollusca, Bivalvia): evidence for high levels of cryptic species diversity.

    Science.gov (United States)

    Lemer, Sarah; Buge, Barbara; Bemis, Amanda; Giribet, Gonzalo

    2014-06-01

    The family Pinnidae Leach, 1819, includes approximately 50 species of large subtidal and coastal marine bivalves. These commercially important species occur in tropical and temperate waters around the world and are most frequently found in seagrass meadows. The taxonomy of the family has been revised a number of times since the early 20th Century, the most recent revision recognizing 55 species distributed in three genera: Pinna, Atrina and Streptopinna, the latter being monotypic. However, to date no phylogenetic analysis of the family has been conducted using morphological or molecular data. The present study analyzed 306 pinnid specimens from around the world, comprising the three described genera and ca. 25 morphospecies. We sequenced the mitochondrial genes 16S rRNA and cytochrome c oxidase subunit I, and the nuclear ribosomal genes 18S rRNA and 28S rRNA. Phylogenetic analysis of the data revealed monophyly of the genus Atrina but also that the genus Streptopinna is nested within Pinna. Based on the strong support for this relationship we propose a new status for Streptopinna Martens, 1880 and treat it as a subgenus (status nov.) of Pinna Linnaeus, 1758. The phylogeny and the species delimitation analyses suggest the presence of cryptic species in many morphospecies displaying a wide Indo-Pacific distribution, including Pinna muricata, Atrina assimilis, A. exusta and P. (Streptopinna) saccata but also in the Atlantic species A. rigida. Altogether our results highlight the challenges associated with morphological identifications in Pinnidae due to the presence of both phenotypic plasticity and morphological stasis and reveal that many pinnid species are not as widely distributed as previously thought.

  15. A contribution to the knowledge of the pectinacean Mollusca (Bivalvia: Propeamussiidae, Entoliidae, Pectinidae) from the Indonesian Archipelago

    NARCIS (Netherlands)

    Dijkstra, H.H.

    1991-01-01

    During the Indonesian-Dutch SNELLIUS -II Expedition (1984-1985) to the Indonesian Archipelago 46 pectinacean species were collected from the Flores Sea and Banda Sea (5°52'-9°57'S, 118°12'-123°58'E) at littoral to bathyal depth (835 m). One new pectinid genus, viz. Glorichlamys gen. nov., six new pr

  16. FMRFamide and related peptides in the phylum mollusca.

    Science.gov (United States)

    López-Vera, Estuardo; Aguilar, Manuel B; Heimer de la Cotera, Edgar P

    2008-02-01

    FMRFamide is one of the well-known peptides studied within the phylum Mollusca. It was first isolated from the clam Macrocallista nimbosa during the end of the 1960s. Since then, a number of reports related to FMRFamide have been published from different experimental approaches, revealing that it and its related peptides (FaRPs) are implicated in a variety of physiological processes. As this year is the 30th anniversary since its discovery, this review focuses on diverse findings related to both FMRFamide and FaRPs in the phylum Mollusca.

  17. De nauwe korfslak Vertigo angustior in Nederland (Mollusca: Gastropoda)

    NARCIS (Netherlands)

    Bruyne, de R.

    2002-01-01

    The narrow whorlsnail Vertigo angustior in the Netherlands (Mollusca: Gastropoda) In June and July 2001, a special survey was held in several coastal areas in the province of Zuid- Holland, the Netherlands. The main objective was retrieving additional data on the occurrence of Vertigo angustior

  18. The Holocene and Recent marine Bivalve Mollusca of Surinam

    NARCIS (Netherlands)

    Regteren Altena, van C.O.

    1968-01-01

    As the preparation of an annotated check list of the marine Mollusca of Surinam (Dutch Guiana) will take some more years, it was thought appropriate to publish a preliminary report on the bivalves. This report consists of a list of 126 species with a few notes containing, i.a., the description of se

  19. Bibliographie der Flussperlmuschel Margaritifera Margaritifera (Linnaeus, 1758) [Mollusca: Pelecypoda

    NARCIS (Netherlands)

    Jungbluth, J.H.; Coomans, H.E.; Grohs, H.

    1985-01-01

    Bibliography of the freshwater Pearlmussel Margaritifera margaritifera (Linnaeus, 1758) [Mollusca: Pelecypoda] The freshwater pearlmussel, described by Linnaeus as Mya margaritifera is one of the most important molluscs existing. It belongs with only a few congeneric fossil and recent species to the

  20. Types of Cenozoic Mollusca from Java in the Martin Collection of Naturalis

    NARCIS (Netherlands)

    Leloux, J.; Wesselingh, F.P.

    2009-01-01

    An updated type catalogue of the Martin Collection (fossil Mollusca, predominantly from the Cenozoic of Java, Indonesia) is presented. Type specimen data, updated locality data, and illustrations are given.

  1. Scanning electron microscopic structure of the prismatic layer in the Bivalvia

    Institute of Scientific and Technical Information of China (English)

    Iwao KOBAYASHI

    2008-01-01

    The shell structure of the Bivalvia has been observed with the use of optical and electron microscopes since the early 1900's. The prismatic structure is one of the more attractive shell structures in bivalved mollusks. This structure is composed of the aggregation of polygonal prisms arranged densely. Each prism is made of small calcite crystallites arranged perpendicular to a growth shell surface. Organic materials, named organic sheaths, accumulate around prisms and stain well with heamatox-ylin-eosin.The Bivalvia, which make prismatic structures, are divided into two groups. One group has the inner shell layer made up of a nacreous structure, and the other has the inner shell layer made up of a foliated structure. The aragonite prismatic layer and the prismatic layer are clo-sely related to each other, as is the aragonite prismatic layer to the composite prismatic one.

  2. A national checklist of marine Mollusca in Spanish waters

    Directory of Open Access Journals (Sweden)

    Serge Gofas

    2017-06-01

    Full Text Available A checklist of marine Mollusca recorded in Spanish jurisdictional waters is presented, based on a thorough literature search and a limited input of recent field work. The list is detailed according to the five demarcations of the Marine Strategy Framework Directive (NOR, Spanish north coast; SUR, Spanish coast of the Gulf of Cádiz; ESAL, Strait of Gibraltar and Alboran Sea; LEBA, East coast of Spain and Balearic Islands; CAN, the Canary Islands. The list differentiates coastal species living from the supralittoral zone to the shelf break, deep-sea benthic or demersal species, and holoplanktonic species, and also distinguishes between non-indigenous species and species endemic to a particular demarcation. A total of 2466 marine Mollusca species have been reported from Spanish waters, of which 1126 are recorded only from waters surrounding the Iberian Peninsula, 498 are recorded from the Canaries only, and 842 are shared. That total number represents around 5.5% of the global marine molluscan richness. Shore and shelf species are the most numerous (1837, followed by deep-sea benthic species (490 and pelagic species (139, but the contribution of the deep-sea species is most noteworthy in NOR. All eight molluscan classes were represented, but solenogastres and scaphopods were notably more represented than usual in NOR. Species richness in SUR and ESAL was higher than would be expected from their areas, supporting the claim that Andalusian waters have an exceptionally diverse molluscan fauna. Thirteen species collected from INDEMARES cruises are here reported for the first time in Spanish waters. The species recorded in Spanish seas represent more than half of the 4340 species of Mollusca recorded within the scope of the European Register of Marine Species, making this the highest species count in European seas. The Canary Islands demarcation holds by far the largest number of endemic species (127, but special mention is needed regarding the ca. 20

  3. DIVERSITAS DAN KERAPATAN MANGROVE, GASTROPODA DAN BIVALVIA DI ESTUARI PERANCAK, BALI

    OpenAIRE

    2011-01-01

    Penelitian ini bertujuan membandingkan diversitas dan kerapatan mangrove dengan kepadatan gastropoda dan bivalvia di mangrove alami dan rehabilitasi. Pengukuran ekosistem mangrove menggunakan transek kuadrat 10 m x 10 m. Kelimpahan dan kepadatan gastropoda dan bialvia menggunakan transek kuadrat berukuran 1 m x 1 m. Analisis nMDS, cluster untuk melihat hubungan karekteristik mangrove alami dan rehabilitasi dianalisis secara deskriptif dan analisis regresi untuk mendetermi...

  4. Long-term feeding with Euglena gracilis cells modulates immune responses, oxidative balance and metabolic condition in Diplodon chilensis (Mollusca, Bivalvia, Hyriidae) exposed to living Escherichia coli.

    Science.gov (United States)

    Bianchi, Virginia A; Castro, Juan M; Rocchetta, Iara; Nahabedian, Daniel E; Conforti, Visitación; Luquet, Carlos M

    2015-02-01

    We evaluated the modulating effect of long-term feeding with lyophilized Euglena gracilis cells on immune response, oxidative balance and metabolic condition of the freshwater mussel Diplodon chilensis. Mussels, previously fed with Scenedesmus vacuolatus (SV) or E. gracilis (EG) for 90 days, were challenged with an environmentally relevant concentration of Escherichia coli in water for 5 days, under feeding or starvation conditions. EG diet increased overall phagocytic activity and tissue hemocyte accumulation (gill and mantle), and favored hemocyte viability upon E. coli challenge. Tissular hemocyte accumulation, and humoral bacteriolytic activity and protein content were similarly stimulated by EG and E. coli, with no further effect when both stimuli were combined. Both, E. coli challenge and EG diet reduced gill bacteriolytic activity with respect to nonchallenged SV mussels, while no effect was observed in challenged EG mussels. Gill and digestive gland protein contents, along with digestive gland bacteriolytic activity were higher in EG than in SV mussels. Both SV and EG mussels showed increased gill mass upon E. coli challenge, while digestive gland mass was increased by bacterial challenge only in SV mussels. Bacterial challenge produced no effect on humoral reactive oxygen species levels of both groups. Total oxyradical scavenging capacity levels was reduced in challenged SV mussels but remained unaffected in EG ones. In general, EG diet decreased glutathione S-transferase and catalase activities in gill and digestive gland, compared with SV diet; but increased enzyme activity was evident in challenged mussels of both groups. Gill and digestive gland lipid peroxidation levels were higher in EG than in SV mussels but E. coli challenge had stronger effect on SV mussels. Adductor muscle RNA:DNA ratio was higher in EG mussels than in SV ones, and increased upon E. coli challenge in mussels of both groups. E. gracilis can be suggested as a nutritional and protective diet complement suitable for filtering bivalves. However, our results obtained from starved mussels show that starvation periods after supplying this diet should be avoided, since these could revert part of the acquired benefits and/or exacerbate detrimental effects.

  5. Occurrence of the cis-4,7,10, trans-13-22:4 fatty acid in the family Pectinidae (Mollusca: Bivalvia).

    Science.gov (United States)

    Kraffe, Edouard; Grall, Jacques; Palacios, Elena; Guerra, Citlali; Soudant, Philippe; Marty, Yanic

    2010-05-01

    The present study aimed to elucidate the effective phylogenetic specificity of distribution of a cis-4,7,10, trans-13-22:4 (22:4(n-9)Delta13trans) among pectinids. For this purpose, we extended the analysis of membrane glycerophospholipids FA composition to 13 species of scallops, covering 11 genera and 7 tribes representatives of the three subfamilies Chlamydinae, Palliolinae and Pectininae and the subgroup Aequipecten. In species belonging to the subfamily Pectininae and the Aequipecten subgroup, 22:4(n-9)Delta13trans was found in substantial amounts, but it was absent in other species belonging to the subfamilies Chlamydinae and Palliolinae. Homologous non-methylene-interrupted (NMI) FA, also hypothesized to differ along phylogenetic lines in bivalves, were totally absent or present only in trace amounts in representatives of the Aequipecten subgroup but ranged from 0.3 to 4.5% of the total FA in Pectinidae, Chlamydinae, and Palliolinae subfamilies. The species-specific occurrence of NMI and 22:4(n-9)Delta13trans FA in membrane lipids of pectinids agrees with the most recent phylogenies based on shell morphology and molecular characteristics. We examined the potential timing of the appearance of 22:4(n-9)Delta13trans in pectinids on a geologic time scale.

  6. Genetic Population Structure of Macridiscus multifarius (Mollusca: Bivalvia) on the Basis of Mitochondrial Markers: Strong Population Structure in a Species with a Short Planktonic Larval Stage.

    Science.gov (United States)

    Ye, Ying Ying; Wu, Chang Wen; Li, Ji Ji

    2015-01-01

    The clam Macridiscus multifarius with a planktonic larval stage of about 10 days is an ecologically and economically important species in the coastal regions of China. In this study, 3 mt-DNA markers (COI, 12S rRNA, and ND1) were used to investigate the population structure and demography of wild M. multifarius populations in 3 coastal localities of the East China Sea (ZS and ZP populations) and Beibu Gulf in the South China Sea (BH population). Sequences of 685 bp in COI, 350 bp in 12S rRNA, and 496 bp in ND1 were determined. High level and significant FST values were obtained among the different localities on the basis of either COI (FST = 0.100-0.444, p < 0.05) or 12S rRNA (FST = 0.199-0.742, p < 0.05) gene, indicating a high degree of genetic differentiation among the populations. FST values were significant but weak for the ND1 gene because it is highly conservative. The median-joining network suggested an obvious genetic differentiation between ZS and BH populations, and the finding is consistent with the results of our demographic analyses using the unweighted pair group method with arithmetic mean. Our study unraveled the extant population genetic structure of M. multifarius and explained the strong population structure of a species with a short planktonic larval stage species; this information could be useful for fishery management measures, including artificial breeding and conservation.

  7. Large Vesicomyidae (Mollusca: Bivalvia) from cold seeps in the Gulf of Guinea off the coasts of Gabon, Congo and northern Angola

    Science.gov (United States)

    von Cosel, Rudo; Olu, Karine

    2009-12-01

    Two new genera and three new species of large Vesicomyidae are described from cold-seep sites on pockmarks and other sulfide-rich environments in the Gulf of Guinea (tropical east Atlantic) off Gabon, Congo (Brazzaville) and northern Angola, from 500 to 4000 m depth: " Calyptogena" (s.l.) regab n. sp., Wareniconcha (n.g.) guineensis (Thiele and Jaeckel 1931), Elenaconcha guiness n.g. n. sp., and Isorropodon atalantae n. sp. For two other species already taken by the R/V Valdivia in 1898, Calyptogena valdiviae (Thiele and Jaeckel 1931) and Isorropodon striatum (Thiele and Jaeckel 1931) new localities were discovered, and the species are rediscussed. E. guiness n.g. n.sp. is also recorded from off Banc d'Arguin, Mauritania, collected by commercial fishing vessels. The vesicomyid species here treated were encountered in different depth ranges along the Gabon-Congo-Angola margin, between 500 and 4000 m depth, and it was found that, in comparison with the dredge samples taken by the Valdivia expedition off southern Cameroon and off Rio de Oro (both at 2500 m), the same species occur in other depth ranges, in some cases with a vertical difference of more than 1000 m. .That means that the species are not confined to a given depth thought being typical for them and that the characteristics of the biotope are likely to play a major role in the distribution of the vesicomyids associated to cold seeps or other reduced environments along the West African margin.

  8. 湘江长沙段的双壳类软体动物%Bivalvia Mollusca in the Changsha Section of Xiang River

    Institute of Scientific and Technical Information of China (English)

    胡自强; 杨海明; 胡少锋

    2004-01-01

    报道了湘江长沙段双壳类软体动物的调查结果,计有双壳类24种及3亚种(其中椭圆背角无齿蚌和橄榄蛏蚌为湖南省新记录种),分别隶属于双壳纲3科17属,其中主要是蚌科珠蚌亚科的种类.并对它们的种类组成、区系、分布、种群大小及栖息环境进行了分析,叙述了优势种的经济价值及利用前景.

  9. First European record of the invasive brackish water clam Rangia cuneata (G.B. Sowerby I, 1831) (Mollusca: Bivalvia)

    OpenAIRE

    Verween, A; Kerckhof, F.; Vincx, M.; Degraer, S.

    2006-01-01

    A population of Rangia cuneata (G.B. Sowerby I, 1831), an estuarine bivalve, has been recorded in the harbour of Antwerp, Belgium. This species is new to the European brackish water fauna. After initially finding only a few small individuals in August 2005, R. cuneata was encountered frequently in the pipes of the cooling water system of an industrial plant from February 2006 onwards. Before this present record, R. cuneata was only known from the Gulf of Mexico and the Atlantic coast of North...

  10. Intra-specific variability in life-history traits of Anadara tuberculosa (Mollusca: Bivalvia in the mangrove ecosystem of the Southern coast of Ecuador

    Directory of Open Access Journals (Sweden)

    Luis Flores

    2014-08-01

    Full Text Available Anadara tuberculosa is one of the most important bivalves along the Western Pacific coast because of its commercial value. Nevertheless, the variability in growth, longlife span, natural mortality and reproductive parameters of this mangrove cockle has not yet been described. The aim of this study was to analyze these lifehistory traits in three areas of the Southern coast of Ecuador. Empirical and length-based methods were used to estimate these biological parameters. Body size data were collected from the commercial fishery between 2004 and 2011 in landing ports near to the Archipelago of Jambeli [Puerto Bolivar (PB, Puerto Jeli (PJ and Puerto Hualtaco (PH]. The von Bertalanffy growth parameters for combined sex were estimated between 70.87 to 93.45mm for L∞ and 0.22 to 0.80/year for k. The growth indices (Φ’ ranged from 3.17 to 3.85, while the overall growth performance (OGP ranged from 5.03 to 5.82. The mean of long-life span (t max, size and age at maturity (L50% and t50% were estimated in 7.71±2.53years, 39.13±2.24mm and 1.46±0.56years for PB; 9.51±2.85years, 37.78±1.95mm and 1.37±0.41years for PJ and 5.81±2.11years, 39.73±3.31mm and 0.94±0.41years for PH. Natural mortality (M ranged from 0.46 to 1.28/year. We concluded that significant intra-specific variation was observed in a temporal scale in Φ’ and OGP indices as well as L50% and M. Therefore, temporal changes in these life-history traits should be taken into account when assessing the status of the mangrove cockle fishery.

  11. Morphological and genetic diversity of the wood-boring Xylophaga (Mollusca, Bivalvia): new species and records from deep-sea Iberian canyons.

    Science.gov (United States)

    Romano, Chiara; Voight, Janet Ruth; Pérez-Portela, Rocío; Martin, Daniel

    2014-01-01

    Deep-sea bivalves of the Xylophagaidae, a poorly known group, are obligate wood-borers. Deployment of wood in three submarine canyons off the Iberian coast, the Blanes and La Fonera Canyons (Mediterranean Sea) and the Avilés Canyon (Cantabric Sea, Bay of Biscay), lead to the discovery of four xylophagaid species in our samples. Xylophaga dorsalis (the dominant species), X. atlantica, X. cf. anselli and the new species X. brava, were identified on the basis of morphological data, and supported by a phylogenetic reconstruction based on the nuclear genes 18S rDNA and 28S rDNA and including several genus of Xylophagaidae. Genetic divergence between species of Xylophaga varied between genes, ranging from 0.5 to 4.0% for the 18SrDNA and from 4.1 to 16.6% for the 28SrDNA. Xylophaga brava sp. nov. appeared to be restricted to the Mediterranean and morphologically resembled the closely related X. cf. anselli from the Cantabrian Sea. However, they clearly diverged in two well-supported clades. Low levels of intraspecific variability and higher interspecific divergence between species also supported the existence of these two different species. Morphologically they differ in the number of cirri at the siphon openings, in the shape of the posterior shell and in the size of prodissoconch II. The new species is characterized by having weak, poorly mineralized mesoplax and siphons united throughout, covered by a periostracal, non-calcified tube; distinct proximal and distal siphons, the former translucent and soft, the latter muscular, with concentric rings. Xylophaga atlantica, previously known only from the western Atlantic, is reported for the first time in the Mediterranean Sea. Whether its presence in the Mediterranean indicates its natural distribution or reflects its recent introduction is unknown. Although xylophagaids have been previously reported to recruit heavily to wood deposited on the seabed, these four species colonized wood suspended 30 m above the seafloor.

  12. Evaluation of the levels of Br, Cl, K, Mg, Mn and V in Perna perna Mussels (Linnaeus, 1758: Mollusca, Bivalvia) collected in coast of Sao Paulo, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Daniele; Vasconcellos, Marina B.A.; Saiki, Mitiki; Catharino, Marilia G.M.; Moreira, Edson G., E-mail: danyseo@uol.com.br, E-mail: mbvascon@ipen.br, E-mail: mitiko@ipen.br, E-mail: mgcatharino@uol.com.br, E-mail: emoreira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sousa, Eduinetty C.P.M. de, E-mail: edvinett@usp.br [Universidade de Sao Paulo (IO/USP), Sao Paulo, SP (Brazil). Instituto Oceanografico. Laboratorio de Ecotoxicologia Marinha e Microfitobentos

    2013-07-01

    In this study the content of Br, Cl, K, Mg, Mn and V was evaluated in samples of Perna perna mussels collected in coastal regions of Sao Paulo (Ponta de Itaipu and Palmas Island, in Santos) subjected to anthropogenic contamination, to compare these values with those of mussels from reference site of Cocanha Beach (in Caraguatatuba). The mussels were collected seasonally from September 2008 to July 2009. They were cleaned, ground, homogenized, lyophilized and then analyzed by Instrumental Neutron Activation Analysis (INAA). The INAA procedure consisted in the irradiation of the samples and synthetic elemental standards for 8 and 10 s, under a thermal neutron flux of 6.6 x 10{sup 12} n cm{sup -2} s{sup -1} in the IEA-R1 nuclear research reactor. For quality control of analytical results, certified reference materials NIST 1566b Oyster Tissue and NIST 2876 Mussel Tissue were analyzed and their results indicated good accuracy. The ranges of concentrations (dry basis) of the elements obtained in mussels collected for the four seasons of the year were: 173.80 to 358.99 mg kg{sup -1} for Br; 45658 ± 1811 to 109166 ± 824 mg kg{sup -1} for Cl; 7043 ± 856 to 12506 ± 675 mg kg{sup -1} for K; 2774 ± 211 to 5691 ± 717 mg kg{sup -1} for Mg; 7.01 ± 0.30 to 29.74 ± 3.32 mg kg{sup -1} for Mn and 0.77 ± 0.02 to 3.43 ± 0.28 mg kg{sup -1} for V. The seasonal and spatial variations of these element concentrations were in this study. (author)

  13. Intra-specific variability in life-history traits of Anadara tuberculosa (Mollusca: Bivalvia) in the mangrove ecosystem of the Southern coast of Ecuador.

    Science.gov (United States)

    Flores, Luis; Licandeo, Roberto; Cubillos, Luis A; Mora, Elba

    2014-06-01

    Anadara tuberculosa is one of the most important bivalves along the Western Pacific coast because of its commercial value. Nevertheless, the variability in growth, long-life span, natural mortality and reproductive parameters of this mangrove cockle has not yet been described. The aim of this study was to analyze these life-history traits in three areas of the Southern coast of Ecuador. Empirical and length-based methods were used to estimate these biological parameters. Body size data were collected from the commercial fishery between 2004 and 2011 in landing ports near to the Archipelago of Jambeli [Puerto Bolivar (PB), Puerto Jeli (PJ) and Puerto Hualtaco (PH)]. The von Bertalanffy growth parameters for combined sex were estimated between 70.87 to 93.45mm for L(infinity) and 0.22 to 0.80/year for k. The growth indices (PHI') ranged from 3.17 to 3.85, while the overall growth performance (OGP) ranged from 5.03 to 5.82. The mean of long-life span (t(max)), size and age at maturity (L50% and t50%) were estimated in 7.71 +/- 2.53 years, 39.13 +/- 2.24mm and 1.46 +/- 0.56 years for PB; 9.51 +/- 2.85 years, 37.78 +/- 1.95mm and 1.37 +/- 0.41 years for PJ and 5.81 +/- 2.11 years, 39.73 +/- 3.31mm and 0.94 +/- 0.41 years for PH. Natural mortality (M) ranged from 0.46 to 1.28/year. We concluded that significant intra-specific variation was observed in a temporal scale in PHI' and OGP indices as well as L50% and M. Therefore, temporal changes in these life-history traits should be taken into account when assessing the status of the mangrove cockle fishery.

  14. Threatened freshwater and terrestrial molluscs (Mollusca, Gastropoda et Bivalvia of Santa Catarina State, Southern Brazil: check list and evaluation of regional threats

    Directory of Open Access Journals (Sweden)

    2011-06-01

    Full Text Available A total of nineteen continental native mollusc species are confirmed for the Santa Catarina State (SC(organized in ten Genera and seven Families, one aquatic Prosobranchia/Caenogastropoda (Ampullariidae,six Pulmonata terrestrial gastropods (one Ellobiidae, three Megalobulimidae and two micro-snails –Charopidae and Streptaxidae and twelve freshwater mussels (eight Mycetopodidae and four Hyriidae. Thesespecies are designated by the International Union for Conservation of the Nature – IUCN as follows: seven as"Vulnerable", six "In Danger" and six “Without Category Established”. The general regional threats that thesespecies are subjected to are briefly analyzed.

  15. Combined effect of temperature and food concentration on the filtration and clarification rates and assimilation efficiency of Atrina tuberculosa Sowerby, 1835 (Mollusca: Bivalvia) under laboratory conditions

    OpenAIRE

    2013-01-01

    In Mexico, Atrina tuberculosa and other bivalve mollusks of commercial importance are intensively exploited, resulting in a drastic decline in their natural populations. This makes the ecophysiological studies of our native mollusks very important. The filtration and clarification rates, and the assimilation efficiency of Atrina tuberculosa at three temperatures (17, 22.5 and 28°C) and three microalgae concentrations (20,000, 40,000 and 60,000 cell•mL-1) were evaluated under laboratory ...

  16. [Lipid and fatty acid profile of Perna viridis, green mussel (Mollusca: Bivalvia) in different areas of the Eastern Venezuela and the West Coast of Trinidad].

    Science.gov (United States)

    Koftayan, Tamar; Milano, Jahiro; D'Armas, Haydelba; Salazar, Gabriel

    2011-03-01

    The species Perna viridis is a highly consumed species, which fast growth makes it an interesting aquaculture alternative for Venezuelan and Trinidad coasts. With the aim to contribute with its nutritional value information, this study analyzed lipid and fatty acid contents from samples taken in five locations from Eastern Venezuela and three from Trinidad West Coast. Total lipids were extracted and quantified, from a pooled sample of 100 organisms per location, by standard gravimetric methods, and their identification and quantification was done by TLC/FID (Iatroscan system). Furthermore, the esterified fatty acids of total lipid, phospholipids and triacylglycerols were identified and quantified by gas chromatography. Eastern Venezuela samples from Los Cedros, La Brea and Chaguaramas showed the highest total lipid values of 7.92, 7.74 and 7.53, respectively, and the minimum values were obtained for La Restinga (6.08%). Among lipid composition, Chacopata samples showed the lowest phospholipid concentration (48.86%) and the maximum values for cholesterol (38.87%) and triacylglycerols (12.26%); besides, La Esmeralda and Rio Caribe samples exhibited maximum phospholipids (88.71 and 84.93 respectively) and minimum cholesterol (6.50 and 4.42%) concentrations. Saturated fatty acids represented between 15.04% and 65.55% within total lipid extracts, with maximum and minimum values for La Esmeralda and Chacopata, respectively. Polyunsaturated results resulted between 7.80 and 37.18%, with higher values in La Brea and lower values in La Esmeralda. For phospholipids, saturated fatty acids concentrations varied between 38.81 and 48.68% for Chaguaramas and Chacopata samples, respectively. In the case of polyunsaturated fatty acids, these varied between non detected and 34.51%, with high concentrations in Los Cedros (27.97%) and Chaguaramas (34.51%) samples. For the triacylglycerols, the saturated fatty acids composition oscillated between 14.27 and 53.80% with low concentrations for Chacopata and high concentration for La Restinga; the polyunsaturated fatty acids were between 4.66 and 35.55% with lower values for Chacopata and higher values for Chaguaramas samples. P. viridis is recommended for human being consumption, according to the high content of unsaturated fatty acids found for this species.

  17. Evaluation of magnesium and manganese in Perna perna mussels (Linnaeus, 1758: mollusca, bivalvia) collected in the cost of the state of Sao Paulo, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Daniele; Vasconcellos, Marina B.A.; Saiki, Mitiko; Cathartino, Marilia G.M.; Moreira, Edson G., E-mail: mbvascon@ipen.b, E-mail: mitiko@ipen.b, E-mail: emoreira@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sousa, Eduinetty C.P.M. de, E-mail: edvinett@usp.b [Universidade de Sao Paulo (IO/USP), SP (Brazil). Inst. Oceanografico. Lab. de Ecotoxicologia Marinha e Microfitobentos

    2011-07-01

    The objective of the present study was to evaluate magnesium and manganese concentrations in Perna perna mussels by applying instrumental neutron activation analysis (INAA). The mussels were collected seasonally from September 2008 to July 2009 at Cocanha Beach in the city of Caraguatatuba (clean region), and at two sites in Santos Bay (Ponta de Itaipu and Palmas Island). The mussel samples were cleaned, grinded, homogenized, lyophilized and then analyzed by INAA. The INAA procedure consisted in the irradiation of the samples and synthetic elemental standards for 10 s, under a thermal neutron flux of 6.6 x 10{sup 12} n cm{sup -2} s{sup -1} in the nuclear research reactor of IPEN-CNEN/SP. The measurements of the gamma radioactivity of the samples and standards were carried out using a hyperpure semiconductor Ge detector, coupled to Digital Spectral Analyzer. The elemental concentrations were calculated by the comparative method. For quality control of analytical results, certified reference materials NIST SRM 1566b oyster tissue and NRC DORM-2 Dogfish Muscle were analyzed and their results indicated good accuracy. The element concentrations in mussels on dry mass basis varied from 2734 {+-} 205 to 5138 {+-} 507 mg kg{sup -1} for Mg and from 7.35{+-}0.57 to 29.06{+-}3.35 mg kg{sup -1} for Mn. The results obtained in mussel analysis indicated that the samples collected in Itaipu in the winter season presented higher accumulation of Mg than the other sites. For Mn, the highest concentrations were obtained for the mussels collected in Palmas in summer time. (author)

  18. Genetic Population Structure of Macridiscus multifarius (Mollusca: Bivalvia) on the Basis of Mitochondrial Markers: Strong Population Structure in a Species with a Short Planktonic Larval Stage

    Science.gov (United States)

    Ye, Ying Ying; Wu, Chang Wen; Li, Ji Ji

    2015-01-01

    The clam Macridiscus multifarius with a planktonic larval stage of about 10 days is an ecologically and economically important species in the coastal regions of China. In this study, 3 mt-DNA markers (COI, 12S rRNA, and ND1) were used to investigate the population structure and demography of wild M. multifarius populations in 3 coastal localities of the East China Sea (ZS and ZP populations) and Beibu Gulf in the South China Sea (BH population). Sequences of 685 bp in COI, 350 bp in 12S rRNA, and 496 bp in ND1 were determined. High level and significant FST values were obtained among the different localities on the basis of either COI (FST = 0.100–0.444, p < 0.05) or 12S rRNA (FST = 0.199–0.742, p < 0.05) gene, indicating a high degree of genetic differentiation among the populations. FST values were significant but weak for the ND1 gene because it is highly conservative. The median-joining network suggested an obvious genetic differentiation between ZS and BH populations, and the finding is consistent with the results of our demographic analyses using the unweighted pair group method with arithmetic mean. Our study unraveled the extant population genetic structure of M. multifarius and explained the strong population structure of a species with a short planktonic larval stage species; this information could be useful for fishery management measures, including artificial breeding and conservation. PMID:26720602

  19. Effects of hydraulic dredging on the physiological responses of the target species Chamelea gallina (Mollusca: Bivalvia: laboratory experiments and field surveys

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    Vanessa Moschino

    2008-09-01

    Full Text Available The effects of mechanical stress in the Venus clam Chamelea gallina during hydraulic dredging were assessed in both laboratory and field studies in order to measure physiological biomarkers at organism level (clearance rate, respiration rate, scope for growth, and survival in air test. In the laboratory, mechanical stress was simulated by shaking clams in a vortex mixer. In the field, clams were collected seasonally at two sites along the northern Adriatic coast (Lido and Jesolo and four levels of stress were applied: the highest was that used in commercial fishing (i.e. high water pressure and mechanised sorting and the lowest manual sampling by SCUBA divers. Survival in air was the most sensitive biomarker in evaluating mechanical stress in the laboratory. Clearance rate also decreased significantly when shaking was applied. Field results indicated that high water pressure and mechanised sorting affected clearance, scope for growth and survival in air, all showing decreasing trends as mechanical stress increased at both sampling sites. The detrimental effects of mechanical disturbance may be emphasised depending on season, when exogenous and endogenous stress increases. A potential risk is highlighted mostly for undersized clams that are fished and then discarded.

  20. The metacercariae of sibling species of Meiogymnophallus, including M. rebecqui comb. nov. (Digenea: Gymnophallidae), and their effects on closely related Cerastoderma host species (Mollusca: bivalvia).

    Science.gov (United States)

    Bowers, E A; Bartoli, P; Russell-Pinto, F; James, B L

    1996-01-01

    The morphology and ecology are described for four sibling species of digenean metacercariae: Meiogymnophallus minutus (Cobbold 1859), M. strigatus (Lebour 1908) from the estuarine cockle Cerastoderma edule L. and M. fossarum (Bartoli, 1965) and M. rebecqui (Bartoli, 1983) comb. nov. from the brackish water lagoon cockle C. glaucum (Poiret). Although occupying different sites within the two species of cockle, both M. minutus and M. fossarum infections result in pathological effects that may cause heavy host mortality. Remarkably, they also result in an inversion of the cockles in situ in the sand such that predation by the final host species is enhanced.

  1. Sediment analysis does not provide a good measure of heavy metal bioavailability to Cerastoderma glaucum (Mollusca: Bivalvia) in confined coastal ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Arjonilla, M.; Gomez-Parra, A. (Instituto de Ciencias Marinas de Andalucia, Puerto Real Cadiz (Spain)); Forja, J.M. (Facultad de Ciencias del Mar, Puerto Real Cadiz (Spain))

    1994-06-01

    Sediments are considered a sink for metals entering the marine environment, especially in coastal areas. Once in the sediment layer, metals are distributed amongst all different phases of the sediment, governed by physicochemical conditions. One fraction is immobilized due to its incorporation into weakly reactive phases of the sediment; Another fraction may remain weakly bound to organic or mineral phases as sorbed, precipitated, or coprecipitated and complexed forms and can be assimilated by detritivorous and suspension-feeding benthic organisms. Many selective procedures have been suggested for metal extraction from sediments in order to estimate concentrations of fractions which are directly or indirectly available to the biota. The absence of a chemical treatment adequate for accurate quantification of metal bioavailability is well-known. Nevertheless, a good correlation between metal content in some organisms and in the sediment after a specific extraction treatment has sometimes been found so sediments are frequently used as indicators in pollution studies. In this paper, concentrations of heavy metals (Fe, Mn, Cu, Ph and Cd) in the cockle Cerastoderma glaucum, and in sediments at the same sampling locations are compared. C. glaucum is a suspension and deposit feeder, inhabiting a wide range of salinities. The study sampled 8 saltponds in the south of Cadiz Bay, located along a gradient of contamination produced by urban and industrial sewage effluents. The study sought to identify areas with different relative risk from metal pollution, in terms of biological effects and effects on water quality due to natural resuspension of sediments or to human relocation of sediments. C. glaucum was selected because of its wide distribution in the Bay, and also because it has no commercial value. This second fact means that its distribution and growth is not directly affected by man. 19 refs., 4 figs., 1 tab.

  2. Raspodjela, brojnost i biološki parametri vrste Cerastoderma glaucum (Mollusca: Bivalvia) duž obale zaljeva Gabes (Tunis, središnji Mediteran)

    OpenAIRE

    Derbali, Abdelkarim; ELHASNI, Kamel; Jarboui, Othman; Ghorbel, Mohamed

    2012-01-01

    Srčanka Cerastoderma glaucum (poiret, 1789) predstavlja jednu od najčešćih vrsta morskih mekušaca prisutnih u infralitoralnim zajednicama mekog dna u vodama Tunisa. Status ove vrste je još uvijek nedovoljno poznat te postoje praznine u znanju o njenoj raspodjeli, brojnosti i biološkim parametrima. značajna ekološka uloga vrste C. glaucum u ekosustavu i mogući budući komercijalni interes zahtijevaju bolje znanje o njenom stoku. Ova studija je usmjerena na istraživanje raspodjele, bro...

  3. Seasonal Variation in the Biochemical Constituents, Percentage Edibility and Condition Index of the Estuarine Clam, Soletellina diphos (Linnaeus, 1771 (Mollusca: Bivalvia: Veneroida: Psammobiidae

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    Vishwajeet M. Lagade

    2015-01-01

    Full Text Available A variety of biochemical analyses and condition indices have been employed by various authors all over the world to assess the chemical and health index of bivalves. In order to understand the effect of seasonal climate change on the nutritive value and physiological fitness of an estuarine population of the psammobiid Soletellina diphos on the West coast of India. The present study was under-taken in order to determine the seasonal fluctuations of the biochemical constituents in different parts of the body and the percentage edibility and condition index. This study has shown that seasonality is related to significant alterations in the biochemical constituents, percentage edibility and condition index (pS. diphos. These changes could be due to the clam’s seasonal activities, particularly those related to its reproductive cycle. Higher values of the protein and lipid contents were recorded during the post-monsoon period, whereas maximum concentrations of glycogen were detected during the winter season. On the other hand, the lowest protein and glycogen contents were recorded during summer, while minimal lipid contents were observed during the winter season. The Percentage Edibility (PE and Condition Index (CI significantly fluctuated during the annual cycle, with maximum values occurring during the post-monsoon period (September-October 2008 and the lowest values during winter (November-December 2008. Therefore, it seems that the best nutritive season for S. diphos is in the post-monsoon period (September-October, when the highest values of its biochemical composition, percentage edibility and condition index occur. However, during the summer season (April-May, the lowest levels of the organic constituents, the percentage edibility and the condition index were recorded. Hence, that season is not ideal from the nutritive point of view. The study concludes that the physiological activity, the nutritive value and the meat quality of the clam S. diphos are seasonally related. Moreover, such baseline information is important from the viewpoint of aquaculture, as it demonstrates the seasonal impact on the nutritive status, reproductive output and physiological fitness of S. diphos.

  4. Analysis of Isozyme Diversities in Atrina pectinata Linnaeus (Mollusca,Bivalvia)%栉江珧同工酶多态性的分析

    Institute of Scientific and Technical Information of China (English)

    余祥勇; 王梅芳; 杨书婷; 桂建芳

    2005-01-01

    采用垂直板聚丙烯酰胺梯度凝胶电泳对栉江珧(Atrina pectinata Linnaeus)消化盲囊进行了5种酶(SOD、EST、MDH、ME、LDH)的同工酶分析.结果表明不同个体的同工酶表达呈现多态现象,个体间酶带带型既有相一致的共同特征谱带,又有较多的变异,5种酶均可把样品大致区分为差异明显的2种或3种类型,而且酶谱类型与形态类型基本对应,同工酶表达上的多样性表明栉江珧种内在生化遗传上存在较大的变异,具有较丰富的遗传多态性.

  5. Analysis of trace elements in the shells of short-necked clam Ruditapes philippinarum (Mollusca: Bivalvia) with respect to reconstruction of individual life history

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Jumpei; Sakamoto, Wataru [Division of Applied Biosciences, Graduate School of Agriculture, Kyoto Univ., Kyoto (Japan)

    1998-07-01

    Strontium (Sr) concentration in the shells of short-necked clams collected at different locations (Shirahama, warm area and Maizuru, cold area, Japan) was analyzed by two methods, PIXE and EPMA. The Sr concentration of external surface of shell umbo, which was made during short term at early benthic phase, was analyzed by PIXE, and was ranged from 1000 to 3500 ppm for individuals. The Sr concentration of clams collected at Shirahama showed positive correlation with shell length (SL) in individuals with SL < 31 mm, whereas clams collected at Maizuru did not show significant correlation. This result may be caused from the difference of the spawning seasons between two areas. The Sr concentration of cross section of shell umbo, which develops thicker continuously during their life to form faint stratum structure, was analyzed by EPMA along the line across the stratum structure. Some surges and long term waving patterns of the Sr concentration were observed. These results suggest that the life histories of individual clams could be recorded in the shell umbo cross sections as variations of trace elements and analyses of trace elements could clarify the histories of individual clams. (author)

  6. 越南沿海的双壳纲软体动物%Studies on the Bivalvia (Mollusca) of the Vietnam Coast

    Institute of Scientific and Technical Information of China (English)

    蔡英亚; 李海燕

    2002-01-01

    报道了越南沿海的双壳纲软体动物320种,隶属3亚纲、6目、26总科、41科、148属.从种类的组成中,帘蛤科有57种,蚶科32种,樱蛤科29种,贻贝科25种,鸟蛤科16种,牡蛎科14种,蛤蜊科13种,珍珠贝科和扇贝科各12种,紫云蛤科11种,竹蛏科10种,其他各科的种类均在7种以内.按种的性质而论,越南沿海主要是由热带种和亚热带种类组成,还有与珊瑚礁紧密联系的热带种.就越南沿海双壳纲软体动物分类区系而论,应属印度-西太平洋区的印尼-马来亚区.

  7. Mitochondrial phylogenomics of the Bivalvia (Mollusca: searching for the origin and mitogenomic correlates of doubly uniparental inheritance of mtDNA

    Directory of Open Access Journals (Sweden)

    Bogan Arthur E

    2010-02-01

    Full Text Available Abstract Background Doubly uniparental inheritance (DUI is an atypical system of animal mtDNA inheritance found only in some bivalves. Under DUI, maternally (F genome and paternally (M genome transmitted mtDNAs yield two distinct gender-associated mtDNA lineages. The oldest distinct M and F genomes are found in freshwater mussels (order Unionoida. Comparative analyses of unionoid mitochondrial genomes and a robust phylogenetic framework are necessary to elucidate the origin, function and molecular evolutionary consequences of DUI. Herein, F and M genomes from three unionoid species, Venustaconcha ellipsiformis, Pyganodon grandis and Quadrula quadrula have been sequenced. Comparative genomic analyses were carried out on these six genomes along with two F and one M unionoid genomes from GenBank (F and M genomes of Inversidens japanensis and F genome of Lampsilis ornata. Results Compared to their unionoid F counterparts, the M genomes contain some unique features including a novel localization of the trnH gene, an inversion of the atp8-trnD genes and a unique 3'coding extension of the cytochrome c oxidase subunit II gene. One or more of these unique M genome features could be causally associated with paternal transmission. Unionoid bivalves are characterized by extreme intraspecific sequence divergences between gender-associated mtDNAs with an average of 50% for V. ellipsiformis, 50% for I. japanensis, 51% for P. grandis and 52% for Q. quadrula (uncorrected amino acid p-distances. Phylogenetic analyses of 12 protein-coding genes from 29 bivalve and five outgroup mt genomes robustly indicate bivalve monophyly and the following branching order within the autolamellibranch bivalves: ((Pteriomorphia, Veneroida Unionoida. Conclusion The basal nature of the Unionoida within the autolamellibranch bivalves and the previously hypothesized single origin of DUI suggest that (1 DUI arose in the ancestral autolamellibranch bivalve lineage and was subsequently lost in multiple descendant lineages and (2 the mitochondrial genome characteristics observed in unionoid bivalves could more closely resemble the DUI ancestral condition. Descriptions and comparisons presented in this paper are fundamental to a more complete understanding regarding the origins and consequences of DUI.

  8. Effects of the invasive macroalga Lophocladia lallemandii on the diet and trophism of Pinna nobilis (Mollusca: Bivalvia and its guests Pontonia pinnophylax and Nepinnotheres pinnotheres (Crustacea: Decapoda

    Directory of Open Access Journals (Sweden)

    Miguel Cabanellas-Reboredo

    2010-03-01

    Full Text Available Pinna nobilis and its guests Pontonia pinnophylax and Nepinnotheres pinnotheres were sampled from Posidonia oceanica meadows invaded and non-invaded by the red alga Lophocladia lallemandii. Understanding the interactions among native and invasive species was the primary aim. Therefore, the effects of the invasive L. lallemandii on the percentage contribution of the food sources of P. nobilis and its guests and their trophic associations were investigated by applying mixing models to the δ13C and δ15N stable isotopes. Isotopic analyses revealed that the guests of P. nobilis occupied a higher trophic level than their host due to their capacity for food selection. The invasion of L. lallemandii altered the percentage contribution of the food sources to the consumers’ diet. Whereas the percentage contribution of the food sources to the δ13C signatures did not really change, L. lallemandii produced variations in the percentage contribution to the δ15N signatures. This red macroalga represented one of the main food sources for P. nobilis, with a real contribution of 19.4% in the invaded meadows. Moreover, L. lallemandii slightly decreased the trophic level of the consumers. This study provides the first isotopic and trophic data for the pea crab N. pinnotheres.

  9. Reproductive activity and biochemical composition of the pullet carpet shell Venerupis senegalensis (Gmelin, 1791 (Mollusca: Bivalvia from Ria de Aveiro (northwestern coast of Portugal

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    Sandra Joaquim

    2011-06-01

    Full Text Available The present study characterizes the reproductive cycle of Venerupis senegalensis (=V. pullastra from Ria de Aveiro (Portugal as well as its nutrient storage and exploitation strategy. The reproductive cycle followed a seasonal cycle that correlated negatively with sea surface temperature, and comprised a ripe stage in winter followed by a spawning period that began in late winter and ended in the early summer. This extended spawning may be an advantageous strategy for the species because it ensures a continuous supply of settlers. Gametogenesis began in late summer/early autumn and intensified with the decrease in temperature during autumn. The condition index increased even during the spawning period, which indicates that there is rapid recovery and that reserves are accumulated during late summer and used later in the gametogenic process. Proteins did not contribute significantly to gametogenesis and the glycogen pattern is typical of conservative species, since gametogenesis depends largely on the amount of glycogen stored. The lipid storage and utilization cycle showed that gametogenesis took place in autumn/winter and that energy reserves were accumulated in summer.

  10. Distribución del género Diplodon (Mollusca: Bivalvia: Hyriidae en territorio Argentino mediante el uso de Colecciones Biológicas

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    Santiago Hernán Torres

    2013-10-01

    Full Text Available Los bivalvos nacaríferos dulciacuícolas (“náyades”, son especies infaunales, endémicas de la RegiónNeotropical, pertenecientes a las familias Hyriidae (Swaison, 1840 y Etheriidae (Swaison, 1840. La alteración del ambiente y la competencia con especies invasoras como Corbicula fluminea (Müller, 1774 y Limnoperna fortunei (Dunker, 1857, impactan sobre las poblaciones naturales. En esta comunicación, se presenta el inicio de un Proyecto de investigación sobre la distribución geográfica de las especies del género Diplodon en la Argentina. Estas especies son un componente importante de la infauna de los cuerpos lóticos y lénticos, viviendo en fondos limosos, limo-arenosos, excepcionalmente en sustratos duros, con un régimen nutricio filtrador, teniendo un papel importante como recicladores de materia orgánica. Conocer la distribución de los bivalvos pertenecientes al género Diplodon en el territorio Argentino permitirá el reconocimiento de potenciales áreas prioritarias para su conservación. Sobre la base de la bibliografía disponible y los ejemplares de las especies del genero Diplodon depositados en la Colección Malacológica del Museo de La Plata (FCNyM-UNLP, se confeccionó una matriz de datos que incluye la identificación del ejemplar, la colección en que se encuentra depositado, el número de catálogo, la localidad y la fecha de colecta. Cada localidad fue ubicada mediante el uso de cartas geográficas de Argentina y revisiones bibliográficas en imágenes satelitales de GoogleEarth, asignando las coordenadas para cada punto. Como resultado del trabajo se obtiene la distribución de estas especies nativas y se discute el grado de solapamiento con las dos especies de bivalvos invasores y el impacto de actividades humanas. 

  11. Morphological and genetic diversity of the wood-boring Xylophaga (Mollusca, Bivalvia: new species and records from deep-sea Iberian canyons.

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    Chiara Romano

    Full Text Available Deep-sea bivalves of the Xylophagaidae, a poorly known group, are obligate wood-borers. Deployment of wood in three submarine canyons off the Iberian coast, the Blanes and La Fonera Canyons (Mediterranean Sea and the Avilés Canyon (Cantabric Sea, Bay of Biscay, lead to the discovery of four xylophagaid species in our samples. Xylophaga dorsalis (the dominant species, X. atlantica, X. cf. anselli and the new species X. brava, were identified on the basis of morphological data, and supported by a phylogenetic reconstruction based on the nuclear genes 18S rDNA and 28S rDNA and including several genus of Xylophagaidae. Genetic divergence between species of Xylophaga varied between genes, ranging from 0.5 to 4.0% for the 18SrDNA and from 4.1 to 16.6% for the 28SrDNA. Xylophaga brava sp. nov. appeared to be restricted to the Mediterranean and morphologically resembled the closely related X. cf. anselli from the Cantabrian Sea. However, they clearly diverged in two well-supported clades. Low levels of intraspecific variability and higher interspecific divergence between species also supported the existence of these two different species. Morphologically they differ in the number of cirri at the siphon openings, in the shape of the posterior shell and in the size of prodissoconch II. The new species is characterized by having weak, poorly mineralized mesoplax and siphons united throughout, covered by a periostracal, non-calcified tube; distinct proximal and distal siphons, the former translucent and soft, the latter muscular, with concentric rings. Xylophaga atlantica, previously known only from the western Atlantic, is reported for the first time in the Mediterranean Sea. Whether its presence in the Mediterranean indicates its natural distribution or reflects its recent introduction is unknown. Although xylophagaids have been previously reported to recruit heavily to wood deposited on the seabed, these four species colonized wood suspended 30 m above the seafloor.

  12. Occurrence, population dynamics and habitat characterization of Mytella guyanensis (Lamarck, 1819 (Mollusca, Bivalvia in the Paraíba do Norte river estuary

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    Alberto Kioharu Nishida

    1995-01-01

    Full Text Available A survey of Mytellaguyanensis occurrence and population dynamics were performed in the Paraíba do Norte river estuary. The characterization and the influence of temperature, salinity and substrate, as well as the associated fauna and flora on the population were also examined. Mytella guyanensis lives buried in the substrate of the mangrove intertidal zone of the Paraíba do Norte river estuary, from the mouth to 24 km upriver. Average annual density of this bivalve species was 5.2 individuals per m², with a predominantly aggregated distribution. The most frequent size was between 4.5 and 5.5 cm in length. Analysis of the substrate demonstrated the presence of two types of substrates in relation to the percentage of silt and clay and the water content. Besides interfering in the population density, the substrate heterogeneity may be a decisive factor in aggregation. Eight species of crustacean decapods and one bivalve species were identified as associated fauna.A ocorrência de M, guyanensis no estuário do Rio Paraíba do Norte foi mapeada, determinando-se sua presença ao longo dos afluentes e ilhas aí existentes. O estudo da dinâmica da população foi realizado em área protegida da Ilha da Restinga, coletando-se os animais ao longo de 37 transecções. A cada mês foram feitos 60 lançamentos com um delimitador de 0,1 m², sobre uma ou mais transecções. Todo o substrato foi retirado juntamente com os exemplares de M. guyanensis e a fauna associada, até a profundidade de 10 cm. A triagem dos exemplares menores foi feita por peneiramento do substrato. O tipo de substrato foi anotado a cada lançamento. Dois tipos de substrato estão presentes na área: um substrato de tipo consistente, constituido por 89.7% de silte e argila e 10.3% de areia fina e outro de tipo não consistente contendo 74.5% de silte e argila e 25.5% de areia fina. O substrato de tipo não consistente apresenta quantidade de água significativamente maior que o de tipo consistente. Mytella guyanensis vive enterrada no solo numa profundidade máxima de 1,0 cm, sempre envolvida pelos filamentos do bisso. A densidade média anual observada para a espécie foi de 5,2 indivíduos por m²; a distribuição espacial predominante foi do tipo agregado, sofrendo interferência do tipo de substrato presente. Houve preferência de fixação da espécie pelo substrato do tipo consistente. Animais entre 4,5 e 5,5 cm de comprimento ocorrem o ano todo, sendo mais numerosos aqueles com comprimento entre 4,5 e 5,0 cm. A presença de formas jovens foi assinalada em baixa frequência em alguns meses do ano. A salinidade da água estuarina variou de acordo com o regime pluviométrico da região, permanecendo dentro dos níveis de tolerância da espécie. A fauna associada está representada por oito espécies de crustáceos e por uma de molusco bivalve.

  13. Producción secundaria e índice de condición en Arca zebra (Mollusca: Bivalvia del Golfo de Cariaco, Venezuela

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    Antulio Prieto Arcas

    2001-06-01

    Full Text Available Se estudió la biomasa, producción secundaria e índice de condición del bivalvo Arca zebra, desde agosto, 1984 hasta agosto, 1985 en Pariche, localidad situada en la costa norte del Golfo de Cariaco, Venezuela. La densidad promedio fue de 37 ind.m-2, con una mayor abundancia a 3 m de profundidad (49.75 ind.m-2. La estructura poblacional es estable con reclutamientos en octubre, diciembre 1984 y junio 19885. Los valores bimensuales de biomasa oscilaron entre 189.86 g Ps m-2 (agosto-84 y 28.51 g Ps m-2 (octubre-84, con un promedio de 93.69 g Ps m-2, y no presentaron diferencias significativas (Fs, P 0.05. Utilizando un método para poblaciones con reproducción contínua y edades no separables, se obtuvo una producción secundaria de 131.61 g Ps. m-2.año-1, y la relación P/B de1.41 año-1. La mayor producción secundaria ocurrió entre febrero 1985 y agosto 1985 (65%, con el mayor aporte por el intervalo 60.00-79.95 mm (45.73%. Se observaron cambios significativos en la variación mensual del índice de condición (IC= (Ps/ Ph x100 en dos clases de tallas analizadas, presentando los valores más altos en julio de 1985 (26.84% y el mínimo en enero de 1985 (16.31%.Production and condition index of a turkeywing (Arca zebra population were studied from August 1984 to August 1985 in Pariche, Cariaco Gulf, Venezuela. Production was studied through bimonthly collections using a method designed for populations with continuous reproduction and indistinguishable age classes. The population distribution was stable with a mean density of 37 ind.m-2. A production of 131.61 g dry weight m-2.year-1 was calcuclated from data on density, biomass and weight increase along the year. Highest production was between February 1985 and August 1985 (65% and concentrated in individuals 60.00-79.95 mm long (45.73%. There was large seasonal variation in the mean monthly condition index (IC= (Ps/Ph x100 in the two size classes examined: it reached a maximum in July 1985 (26.84% and a minimum in January 1985 (16.31%.

  14. Length class and histological description of the gonads of Diplodon ellipticus (Wagner, 1827 (Mollusca, Bivalvia, Hyriidae at an artificial lake, Morretes, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Ana Aparecida Nogueira Meyer

    2014-09-01

    Full Text Available This study aimed to analyze the frequency by length classes and the histological organization of gonads of Diplodon ellipticus at an artificial lake located in the town of Morretes, Paraná, Brazil. Six bimonthly sampling campaigns were conducted within the period from July 2009 to May 2010, with capture of 150 specimens. The total length of shells was measured for determining the frequencies of length classes and an analysis of the presence of marsupials in branchiae was performed. Sex determination was performed through histological analysis of cross sections of the visceral mass. We registered 8 length classes, with an interval of 9 mm, and the modal class varied between 50 and 59 mm. The population is predominantly dioecious, with occurrence of hermaphrodite specimens at low frequency. Marsupials were registered among females (86% in all sampling campaigns and in 2 hermaphrodite specimens. Histological analyses showed that spermatogenesis and oogenesis occur over the year, indicating that D. ellipticus has a strategy that provides continuous reproduction, with peaks of glochidia release.

  15. Current knowledge on population studies on five continental molluscs (Mollusca, Gastropoda et Bivalvia of Santa Catarina State (SC, Central Southern Brazil region

    Directory of Open Access Journals (Sweden)

    A. Ignacio Agudo-Padrón

    2011-03-01

    Full Text Available Although still very scarce, available knowledge on population studies on continental (land and freshwatermolluscs in the territory of Santa Catarina State is shortly analyzed and discussed. Based on the IUCN“Restricted Distribution” criterion, a total of 54 nominal species, including 31 terrestrial gastropods, 15freshwater gastropods and 8 limnic bivalves, were considered strong candidates as threatened taxa. Out of allthese endangered species, only 5 limnic forms (2 gastropods and 3 bivalves were previously analysed, in someway, at population level.

  16. Taxonomy, distribution and population structure of invasive Corbiculidae (Mollusca, Bivalvia in the Suquía River basin, Córdoba, Argentina

    Directory of Open Access Journals (Sweden)

    Paola B. Reyna

    2013-06-01

    Full Text Available Invasive species are one of the most significant causes of biodiversity loss and changes in ecosystem services, which underlines the importance of their detection and their study. The Asian clams (Corbiculidae are invasive organisms that accidentally entered the La Plata River, Argentina, presumably in the 1960s. The objectives of the present study were to identify the corbiculid species and to determine their distribution at several locations along the Suquía River basin, an extended area in central Argentina. In addition, population structure was evaluated monthly during one year, at a site in the city of Córdoba that is characterized by high human influence. The presence of Corbicula fluminea (Müller, 1774 and Corbicula largillierti (Philippi, 1844 in the Suquía River basin is reported for the first time. The former species was found only in a lentic environment (San Roque reservoir, while the latter was also found along the tributary rivers and brooks of the basin. Corbicula largillierti showed variations in average density between the different sites and also in biomass and size classes throughout the study period at the site at Córdoba city. The relative composition of the sediments, flow fluctuation and human pollution may be responsible for the observed differences.

  17. On the stratigraphic position of the Delden Member (Breda Formation, Overijssel, the Netherlands) with implications for the taxonomy of Pygocardia (Mollusca, Bivalvia)

    NARCIS (Netherlands)

    Bosch, J.; Wesselingh, F.P.

    2006-01-01

    Re-identification of parts of the mollusc fauna of the Delden Member, especially Pygocardia and Panopea species, from the vicinity of Delden (Overijssel prov., the Netherlands) and comparison with other Neogene faunas from the southern North Sea Basin imply a late Early to early Late Pliocene age fo

  18. Molecular phylogeny and shell microstructure of Fungiacava eilatensis Goreau et al. 1968, boring into mushroom corals (Scleractinia: Fungiidae), in relation to other mussels (Bivalvia: Mytilidae)

    NARCIS (Netherlands)

    Owada, M.; Hoeksema, B.W.

    2011-01-01

    Research on the evolution of the symbiosis between the boring mussel Fungiacava eilatensis (Bivalvia: Mytilidae) and its mushroom coral hosts (Scleractinia: Fungiidae), which requires phylogenetic reconstructions of both the Mytilidae and the Fungiidae, contributes to the understanding of the comple

  19. Descriptions of three new species of Mitridae (Mollusca: Gastropoda) from South China Sea

    Institute of Scientific and Technical Information of China (English)

    LI Baoquan; ZHANG Suping; LI Xinzheng

    2005-01-01

    Three new species of Family Mitridae (Mollusca: Gastropoda) from the South China Sea are described in the present paper. They are Ziba aglais sp. nov. B. LI & S. ZHANG, Neocancilla daidaleosa sp.nov. B. LI & X. LI, and Mitra holkosa sp. nov. B. LI. Their systematic positions are also discussed.

  20. Holoplanktonic Mollusca: development in the Mediterranean Basin during the last 30 million years and their future

    NARCIS (Netherlands)

    Janssen, A.W.; Peijnenburg, K.T.C.A.; Goffredo, S.; Dubinsky, Z.

    2014-01-01

    A short introduction is given to the systematics and morphology of pelagic Gastropoda (Mollusca: Heteropoda and Pteropoda), also explaining some details of the animals’ particular way of life. The fossil record of these invertebrates is discussed briefly, followed by an overview of existing literatu

  1. A honeycomb composite of mollusca shell matrix and calcium alginate.

    Science.gov (United States)

    You, Hua-jian; Li, Jin; Zhou, Chan; Liu, Bin; Zhang, Yao-guang

    2016-03-01

    A honeycomb composite is useful to carry cells for application in bone, cartilage, skin, and soft tissue regenerative therapies. To fabricate a composite, and expand the application of mollusca shells as well as improve preparing methods of calcium alginate in tissue engineering research, Anodonta woodiana shell powder was mixed with sodium alginate at varying mass ratios to obtain a gel mixture. The mixture was frozen and treated with dilute hydrochloric acid to generate a shell matrix/calcium alginate composite. Calcium carbonate served as the control. The composite was transplanted subcutaneously into rats. At 7, 14, 42, and 70 days after transplantation, frozen sections were stained with hematoxylin and eosin, followed by DAPI, β-actin, and collagen type-I immunofluorescence staining, and observed using laser confocal microscopy. The composite featured a honeycomb structure. The control and composite samples displayed significantly different mechanical properties. The water absorption rate of the composite and control group were respectively 205-496% and 417-586%. The composite (mass ratio of 5:5) showed good biological safety over a 70-day period; the subcutaneous structure of the samples was maintained and the degradation rate was lower than that of the control samples. Freezing the gel mixture afforded control over chemical reaction rates. Given these results, the composite is a promising honeycomb scaffold for tissue engineering.

  2. Anti-ulcer potentials of phylum mollusca (tropical snail) slime

    Institute of Scientific and Technical Information of China (English)

    Nwodo NJ; Okonta J M; Ezugwu CO; Attama AA

    2009-01-01

    Objective:The effectiveness of the slimy substance in snail to regenerate and repair damaged areas on its body/shell lead to this investigation.Methods:The anti-ulcer'property of snail slime extracted from phylum mollusca (tropical snail)from the giant African snail Archachatina marginata (Fam.Arionidae)was investi-gated using histamine,stress and indomethacin-induced ulcers.The solubility profile of extract was investiga-ted in different solvents and at different temperatures.Chemical analysis was carried out to determine the types of constituents present in the slim,while acute toxicity test was carried out to evaluate its profile of toxicity. The effect of the snail slim on gastrointestinal motility was investigated in mice,while the guinea pig ileum was used to study the effect of the extract on contraction produced by acetylcholine and histamine.The snail slime contained copious quantity of protein,with varying amounts of simple sugars,carbohydrates and fats.The slime was not soluble in most common solvents and increases in temperature,did not appear to increase its sol-ubility.Results:The result further indicated that although the snail slime exhibited significant (P <0.05)an-ti-ulcer induced by stress and histamine,it was most potent against ulcer induced by indomethacin.The snail slime potently inhibited gastrointestinal movement in mice in a dose-dependent manner;however,it was not a-ble to inhibit contraction induced by acetylcholine and histamine in guinea pig ileum.Conclusion:The snail mucin possesses potent antiulcer properties without any toxic effect.The mechanism responsible for the anti-ul-cer property may not be postulated with certainty but cytoprotective and anti-spasmodic activities are most likely to be involved.

  3. PHYSIOLOGICAL RESPONSES OF THE BROWN MUSSEL Perna perna (MOLLUSCA, BIVALVIA EXPOSED TO THE ANIONIC SURFACTANT LINEAR ALKYLBENZENE SULPHONATE (LAS = RESPOSTAS FISIOLÓGICAS DE MEXILHÃO Perna perna (MOLLUSCA, BIVALVIA EXPOSTO AO SURFACTANTE ANIÔNICO ALQUILBENZENO SULFONATO LINEAR (LAS

    Directory of Open Access Journals (Sweden)

    Marina Freitas Stefanoni

    2011-01-01

    Full Text Available The effects of the Linear Alkylbenzene Sulphonate (LAS were evaluated on the mussel Perna perna, using physiological and genotoxic biomarkers. The Micronuclei (MN assay was used to estimate effects at nuclear level, whereas the physiological effects were evaluated by measuring the oxygen consumption and ammonia excretion rates. Significant effects were observed for the MN assay and the ammonia excretion rate, even in low concentrations. The oxygen consumption was not affected in the tested concentrations. For MN and ammonia excretion, the animals exposed to intermediate concentrations were not affected, but responded to the higher concentrations, indicating the existence of compensatory mechanisms at physiological level. However, parallel to this study other authors indicate the presence of progressive effects at the cellular level, suggesting that the organisms are not capable to recover of such increasing effects. Additionally, the results show that the levels of LAS observed for Brazilian coastal waters may chronically affect the biota. = Os efeitos do Alquilbenzeno Sulfonato de Sódio Linear sobre o mexilhão Perna perna foram avaliados por meio do uso de biomarcadores genotóxicos e fisiológicos. O ensaio da taxa de micronúcleos (MN foi conduzido para estimar o efeito ao nível nuclear, enquanto os efeitos fisiológicos foram avaliados através da medição da taxa de consumo de oxigênio e de excreção de amônia. Efeitos significativos foram observados para o ensaio do MN e para a taxa de excreção de amônia, mesmo em baixas concentrações. O consumo do oxigênio não foi afetado pelas concentrações dos ensaios. Para MN e excreção de amônia, os animais expostos às concentrações intermediárias não foram afetados, mas responderam às maiores concentrações, sugerindo a existência de mecanismos compensatórios em nível fisiológico. Contudo, paralelamente ao presente estudo, outros autores demonstraram haver efeitos progressivos em nível celular, sugerindo que os organismos não conseguem se recuperar dos efeitos crescentes da exposição. Os resultados ainda mostram que níveis de LAS presentes na costa brasileira podem afetar cronicamente a biota.

  4. Ciclo gametogênico e comportamento reprodutivo de Iphigenia brasiliana (Mollusca, Bivalvia, Donacidae no estuário do rio Subaé, Baía de Todos os Santos, Bahia, Brasil Gametogenic cycle and reproductive behavior of Iphigenia brasiliana (Mollusca, Bivalvia, Donacidae in the Subaé river estuary, Todos os Santos Bay, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Patrícia P. Silva

    2012-12-01

    Full Text Available Este estudo teve como objetivos descrever o ciclo gametogênico e o comportamento reprodutivo da população de Iphigenia brasiliana (Lamarck,1818 no estuário do rio Subaé, Baía de Todos os Santos, Bahia. Os bivalves foram coletados de novembro de 2001 a novembro de 2002. Um total de 244 espécimes foi medido (eixo anteroposterior, eviscerado, fixado, desidratado e incluído em parafina. O estudo histológico das gônadas foi realizado através de cortes seriados do tecido gonadal, de 5 mm de espessura, e corados pela HE. O tamanho médio mínimo da primeira maturação sexual (Lpm foi estimado a partir da distribuição das frequências relativas de jovens e adultos, por classe de comprimento dos indivíduos. As frequências relativas dos sexos em cada estádio de desenvolvimento foram consideradas conjuntamente para a análise do comportamento reprodutivo da população, e, em separado, para avaliar a sincronia do ciclo sexual entre machos e fêmeas. Foi observada uma variação de tamanhos entre 9,1 e 66,6 mm, com comprimento médio de 50,2 mm. O estudo não demonstrou diferença significativa entre os tamanhos de machos e fêmeas. Não foi possível observar a diferenciação de sexos em 2,1% dos indivíduos analisados. 51,6% dos indivíduos foram identificados como machos (M e 46,3% como fêmeas (F, não sendo constatadas diferenças significativas entre o número médio de machos e fêmeas, resultando numa proporção de M:F de 1,1:1. O Lpm foi estimado em 11,4 mm, mas apenas ao alcançarem comprimento médio de 34,4 mm, todos os indivíduos foram considerados adultos. Foram caracterizados quatro estádios de evolução do desenvolvimento gonadal em fêmeas e machos. A análise dos diferentes estádios permitiu a observação dos fenômenos de atresia e inversão sexual em fêmeas. O ciclo reprodutivo apresentou eliminação contínua de gametas, com maiores intensidades reprodutivas nos meses de novembro de 2001 a abril de 2002 e, também, no mês de outubro de 2002.This study aimed to describe the gametogenic cycle and reproductive behavior of the population of Iphigenia brasiliana (Lamarck, 1818 in the estuary of the Subaé river, Todos os Santos Bay, Bahia. The bivalves were collected from November 2001 to November 2002. A total of 244 specimens was measured (anteroposterior axis, gutted, fixed, dehydrated and embedded in paraffin. The histology of the gonads was performed by 5 mm thick serial sections of gonadal tissue, and stained with HE. The length at the beginning of gonadal maturation (Lpm was estimated from the distribution of the relative frequencies of youth and adults, by length class of individuals. The relative frequencies of the sexes at each stage of development were considered together for the analysis of the reproductive behavior of the population, and, separately, to assess the sexual cycle synchrony between males and females. We observed a variation of sizes between 9.1 and 66.6 mm, with a mean length of 50.2 mm. The study showed no significant difference between the sizes of males and females. There was no evidence of gender differentiation in 2.1% of subjects analyzed. 51.6% of subjects were identified as males (M and 46.3% as females (F, without significant differences among average number of male and female, resulting in the proportion of M:F ratio of 1,1:1. Lpm was estimated at 11.4 mm, but only to achieve average length of 34.4 mm, all subjects were considered adults. We characterized four stages of evolution of gonadal development in females and males. Analysis of different stages allowed the observation of the atresia phenomena and sex reversal in females. The reproductive cycle presents continuous elimination of gametes, with higher reproductive intensities in the months of November 2001 to April 2002 and also in October 2002.

  5. Avaliação da infestação e diversidade de Teredinidae (Mollusca - Bivalvia ao longo da costa do estado do Rio de Janeiro, Brasil Evaluation of the infestation and diversity of Teredinidae (Mollusca - Bivalvia along the coast of Rio de Janeiro State, Brazil

    Directory of Open Access Journals (Sweden)

    Andrea de O. R. Junqueira

    1989-01-01

    Full Text Available In order to evaluate the diversity and infestation level of Teredinidae wood-boring molluscs, ten satations were chosen along the coast of Rio de Janeiro State. Using five pine-wood panels in each station, it was possible to distinguish five areas according to species dominance. Ilha Grande Bay is characterized by the dominance of Lyrodus floridanus (Bartsch, 1922; Sepetiba Bay, by Bankia fimbriatula Moll & Roch, 1931, Tijuca Lagoon by Teredo navalis Linnaeus, 1758; Guanabara Bay by Notoredo knoxi (Bartsch, 1917 and Araruama Lagoon by Teredo furcifera Martens, 1894. Specific composition and dominance of these species were due mainly to abiotic factors such as salinity whereas infestation level was associated not only to salinity but also to other factors such as the quantity and quality of fouling, the presence of larval dispersion focus and the wood supply in each area.

  6. Avaliação da infestação e diversidade de Teredinidae (Mollusca - Bivalvia) ao longo da costa do estado do Rio de Janeiro, Brasil Evaluation of the infestation and diversity of Teredinidae (Mollusca - Bivalvia) along the coast of Rio de Janeiro State, Brazil

    OpenAIRE

    Junqueira, Andrea O. R.; Sergio Henrique G. da Silva; Maria Júlia M. Silva

    1989-01-01

    In order to evaluate the diversity and infestation level of Teredinidae wood-boring molluscs, ten satations were chosen along the coast of Rio de Janeiro State. Using five pine-wood panels in each station, it was possible to distinguish five areas according to species dominance. Ilha Grande Bay is characterized by the dominance of Lyrodus floridanus (Bartsch, 1922); Sepetiba Bay, by Bankia fimbriatula Moll & Roch, 1931, Tijuca Lagoon by Teredo navalis Linnaeus, 1758; Guanabara Bay by Notoredo...

  7. Triplodon chodo, a new species of pearly fresh water mussel from the Amazon Basin (Mollusca: Bivalvia: Unionoida: Hyriidae Triplodon chodo, uma nova espécie de bivalve de água doce da bacia Amazônica (Mollusca: Bivalvia: Unionoida: Hyriidae

    Directory of Open Access Journals (Sweden)

    Maria C. D. Mansur

    2008-03-01

    Full Text Available A new species of the genus Triplodon Spix, 1827 is described based on shell samples collected on Rivers Jamari (Rondônia State and Aripuanã (Amazonas State from the Madeira River Basin; on the Amazon at Oriximiná and on the mouth of Tapajós River at Alter do Chão (Pará State. Triplodon chodo is a new species considered closely related to T. stevensi Lea, 1871, (described from the part of the River Essequibo which borders the Guianas. Triplodon chodo is distinguished from the latter by its smaller, lighter shell, the absence of a wing in the anterior region and by the delicate shape of the external sculpture, which is composed of minuscule nodules organized in rows that converge and crosses on the centre of the valves. The straight and vertical posterior margin forms a right or slightly obtuse angle with the shell's dorsal and ventral margins. The anterior region is short, low and slightly tapering, with the distal extremity situated on the half of the shell height. The dorsal and ventral margins are equally curved.Descreve-se uma nova espécie do gênero Triplodon Spix, 1827 com base em conchas coletadas nos rios Jamari (estado de Rondônia e Aripuanã (estado do Amazonas da bacia do rio Madeira; no rio Amazonas, em Oriximiná e na desembocadura do rio Tapajós, junto a Alter do Chão (estado do Pará. Triplodon chodo é uma nova espécie, considerada como muito afim à T. stevensi Lea, 1871 (descrita para a parte do rio Essequibo que faz fronteira com as Guianas, que se distingue dessa última pela concha menor, mais frágil, pela ausência de expansão alada na região anterior e pela forma delicada da escultura externa, composta por numerosos e minúsculos nódulos organizados em fileiras que convergem e se cruzam na parte central das valvas. A margem posterior é reta e vertical formando um ângulo reto ou levemente obtuso com as margens dorsal e ventral da concha. A região anterior é curta, baixa e levemente descendente apresentando a extremidade distal situada na metade da altura total da concha. As margens ventral e dorsal são igualmente curvas.

  8. Land snails (Mollusca: Gastropoda of India: status, threats and conservation strategies

    Directory of Open Access Journals (Sweden)

    S. Sen

    2012-09-01

    Full Text Available Land snails form an important component in the forest ecosystem. In terms of number of species, the phylum Mollusca, to which land snails belong, is the largest phylum after Arthropoda. Mollusca provide unique ecosystem services including recycling of nutrients and they provide a prey base for small mammals, birds, snakes and other reptiles. However, land snails have the largest number of documented extinctions, compared to any other taxa. Till date 1,129 species of land snails are recorded from Indian territory. But only basic information is known about their taxonomy and little is known of their population biology, ecology and their conservation status. In this paper, we briefly review status, threats and conservation strategies of land snails of India.

  9. Distribution patterns of the Jurassic ostreids (Bivalvia) from Tanggula of China

    Institute of Scientific and Technical Information of China (English)

    沙金庚

    2001-01-01

    Distribution of the Jurassic ostreids (Bivalvia) from Tanggula area of China includes three patterns, which are (1) Tethys: containing Liostrea birmanica and Eligmus rollandi, (2) western Europe and northern Tethys: consisting of Gryphaea (Bilobissa) bilobata; and (3) Global: composed of Actinostreon gregareum and Nanogyra nana. However, they are all limited between palaeolatidudes 60° South and North. Actinostreon gregareum originated in the Sinemurian of northern Chile and it entered Kenya and Madagascar in the Toarcian, but there is no reliable Si-nemurian-Toarcian A. gregareum fossil record in continental margins between Chile and Kenya and Madagascar. Such distribution patterns and dispersal processes have demonstrated that (1) during the Jurassic all seas and oceans were connected to each other; (2) the Tethys and the western European epicontinental seas did produce some endemic taxa; (3) the distribution of these ostreids was most likely controlled by latitudes and creature ecology; and (4) A, gr

  10. Biocenosis de Bivalvia y Polyplacophora del intermareal rocoso en playa Tlacopanocha, Acapulco, Guerrero, México Polyplacophora and Bivalvia biocenosis at rocky intertidal Tlacopanocha beach, Acapulco, Guerrero, Mexico

    Directory of Open Access Journals (Sweden)

    Lizeth Galeana-Rebolledo

    2012-11-01

    Full Text Available El Estado de Guerrero, México, tiene regiones marinas prioritarias para la conservación de su biodiversidad y la información acerca de la diversidad de moluscos es escasa, por lo que es necesario realizar inventarios de especies, estudios de ecología de poblaciones y comunidades. Este estudio se efectuó en el intermareal rocoso de la playa Tlacopanocha. Los objetivos fueron: determinar la riqueza, densidad y diversidad de especies; analizar la composición de especies y estructura de tallas. El área de muestreo fue de 10 m² y la unidad de muestreó fue de 1 m². Se identificaron 35 especies, de las cuales tres son nuevos registros para el intermareal rocoso de Guerrero: las familias mejor representadas en riqueza de especies fueron Ischnochitonidae y Arcidae, y en abundancia Chitonidae y Chamidae; la densidad fue de 31,60 ind m-2. Polyplacophora presentó 42,9% de especies dominantes y Bivalvia 19,0%. Chama corallina presentó la mayor talla en longitud y Chama sordida en ancho. La riqueza de especies de moluscos registrada se considera alta y corresponde a lo esperado para un sustrato rocoso en zona tropical. Polyplacophora presentó alta composición de especies, que podría ser resultado de la adaptación de los organismos a las condiciones dinámicas del intermareal rocoso. Los nuevos registros indican la importancia de los inventarios de especies y también del conocimiento de las poblaciones y comunidades de la fauna marina de Guerrero.The State of Guerrero, Mexico, has priority marine areas for conservation of its biodiversity, but information concerning diversity of mollusks is limited, so it is convenient to carry out species inventories, studies of populations and community ecology. This study was conducted in the intertidal rocky beach Tlacopanocha. The objectives were to determine richness, density and species diversity, analyze the species composition and size structure. The sampling area was 10 m² and the sampling unit was

  11. A Holistic Approach to Taxonomic Evaluation of Two Closely Related Endangered Freshwater Mussel Species, the Oyster Mussel (Epioblasma capsaeformis) and Tan Riffleshell (Epioblasma florentina walkeri) (Bivalvia: Unionidae)

    OpenAIRE

    Jones, Jess Walter

    2004-01-01

    A Holistic Approach to Taxonomic Evaluation of Two Closely Related Endangered Freshwater Mussel Species, the Oyster Mussel (Epioblasma capsaeformis) and Tan Riffleshell (Epioblasma florentina walkeri) (Bivalvia: Unionidae) by Jess W. Jones Richard J. Neves, Chairperson Fisheries and Wildlife Sciences (ABSTRACT) Primers for 10 polymorphic DNA microsatellite loci were developed and characterized for the endangered oyster mussel Epioblasma capsaeformis from the Clinch River, TN. Microsatellite...

  12. Inventarisatie van de landslakken van de Zeeuwse kust, met de nadruk op de nauwe korfslak Vertigo angustior (Mollusca: Gastropoda).

    NARCIS (Netherlands)

    Boesveld, A.

    2006-01-01

    The distribution of the land snails of the province of Zeeland, with special emphasis on Vertigo angustior (Mollusca: Gastropoda) In 2005 the land snail fauna of the coast of the province of Zeeland was mapped. In total 98 soil and litter samples were taken and on 54 localities records were gathered

  13. Cenozoic Molluscan types from Java (Indonesia) in the Martin Collection (Division of Cenozoic Mollusca), National Museum of Natural History, Leiden

    NARCIS (Netherlands)

    Hoek Ostende, van den L.W.; Leloux, J.; Wesselingh, F.P.; Winkler Prins, C.F.

    2002-01-01

    An inventory of type material in the ‘Martin Collection’ at the Division of Cenozoic Mollusca of the National Museum of Natural History, Leiden, The Netherlands has been made. In total 1842 lots containing over 5700 type specimens of 912 species were encountered. The status of the types is outlined.

  14. Babosas terrestres (Mollusca, Gastropoda de la Región de Murcia (SE España

    Directory of Open Access Journals (Sweden)

    Borredà, V.

    2014-09-01

    Full Text Available Terrestrial slugs (Mollusca, Gastropoda from Murcia (SE Spain This study examines the few citations about terrestrial slugs from Murcia (SE Spain and adds data from our own surveys. We provide a systematic checklist of the species of terrestrial slugs known from Murcia (SE Spain and comment on the most significant species: Deroceras nitidum, Arion gilvus and A. lusitanicus s. l.

  15. The mitochondrial genome of the sipunculid Phascolopsis gouldii supports its association with Annelida rather than Mollusca

    Energy Technology Data Exchange (ETDEWEB)

    Boore, Jeffrey L.; Staton, Joseph

    2001-09-01

    We have determined the sequence of about half (7470 nts) of the mitochondrial genome of the sipunculid Phascolopsis gouldii, the first representative of this phylum to be so studied. All of the 19 identified genes are transcribed from the same DNA strand. The arrangement of these genes is remarkably similar to that of the oligochaete annelid Lumbricus terrestris. Comparison of both the inferred amino acid sequences and the gene arrangements of a variety of diverse metazoan taxa reveals that the phylum Sipuncula is more closely related to Annelida than to Mollusca. This requires reinterpretation of the homology of several embryological features and of patterns of animal body plan evolution.

  16. Studies on the ecology of Saccostrea cucullata (Born, 1778 ...

    African Journals Online (AJOL)

    ... of Saccostrea cucullata (Born, 1778) (Mollusca: Bivalvia) on the east coast of ... Most populations had a unimodal size distribution in which small individuals were ... areas, suggesting that size distribution was unrelated to human exploitation.

  17. Evolution of sex-dependent mtDNA transmission in freshwater mussels (Bivalvia: Unionida).

    Science.gov (United States)

    Guerra, Davide; Plazzi, Federico; Stewart, Donald T; Bogan, Arthur E; Hoeh, Walter R; Breton, Sophie

    2017-05-08

    Doubly uniparental inheritance (DUI) describes a mode of mtDNA transmission widespread in gonochoric freshwater mussels (Bivalvia: Palaeoheterodonta: Unionida). In this system, both female- and male-transmitted mtDNAs, named F and M respectively, coexist in the same species. In unionids, DUI is strictly correlated to gonochorism and to the presence of the atypical open reading frames (ORFans) F-orf and M-orf, respectively inside F and M mtDNAs, which are hypothesized to participate in sex determination. However, DUI is not found in all three Unionida superfamilies (confirmed in Hyrioidea and Unionoidea but not in Etherioidea), raising the question of its origin in these bivalves. To reconstruct the co-evolution of DUI and of ORFans, we sequenced the mtDNAs of four unionids (two gonochoric with DUI, one gonochoric and one hermaphroditic without DUI) and of the related gonochoric species Neotrigonia margaritacea (Palaeoheterodonta: Trigoniida). Our analyses suggest that rearranged mtDNAs appeared early during unionid radiation, and that a duplicated and diverged atp8 gene evolved into the M-orf associated with the paternal transmission route in Hyrioidea and Unionoidea, but not in Etherioidea. We propose that novel mtDNA-encoded genes can deeply influence bivalve sex determining systems and the evolution of the mitogenomes in which they occur.

  18. University Marine Biological Station Millport Annual Report

    Science.gov (United States)

    1987-07-31

    34Species of the Family Nuculidae (Bivalvia: Protobranchia) from the Deep Atlantic: their Taxonomy , Form and Function". (Supervisor: Professor J.A. Allen...ALLEN, J.A., & HANNAH, F.J. 1986, A reclassification of the Subclass Protobrancnia ( Mollusca : Bivalvia). J ConCn. 32j 225-249. ALLEN, J.A. 1987. Sir

  19. On the establishment of two more alien mollusca (Chama aspersa Reeve, 1846 and Chama asperella Lamarck, 1819 in the eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    P. OVALIS

    2012-12-01

    Full Text Available The Indo-Pacific bivalvia Chama aspersa Reeve, 1846 and Chama asperella Lamarck, 1819 are recorded for the first time in Greek waters. These findings represent a considerable expansion in the eastern Mediterranean. Ship fouling is assumed as the most probable transportation means. However, natural dispersal via the Suez Canal is feasible as well.

  20. Factors driving changes in freshwater mussel (Bivalvia, Unionida) diversity and distribution in Peninsular Malaysia.

    Science.gov (United States)

    Zieritz, Alexandra; Lopes-Lima, Manuel; Bogan, Arthur E; Sousa, Ronaldo; Walton, Samuel; Rahim, Khairul Adha A; Wilson, John-James; Ng, Pei-Yin; Froufe, Elsa; McGowan, Suzanne

    2016-11-15

    Freshwater mussels (Bivalvia, Unionida) fulfil important ecosystem functions and are one of the most threatened freshwater taxa globally. Knowledge of freshwater mussel diversity, distribution and ecology in Peninsular Malaysia is extremely poor, and the conservation status of half of the species presumed to occur in the region has yet to be assessed. We conducted the first comprehensive assessment of Peninsular Malaysia's freshwater mussels based on species presence/absence and environmental data collected from 155 sites spanning all major river catchments and diverse habitat types. Through an integrative morphological-molecular approach we recognised nine native and one widespread non-native species, i.e. Sinanodonta woodiana. Two species, i.e. Pilsbryoconcha compressa and Pseudodon cambodjensis, had not been previously recorded from Malaysia, which is likely a result of morphological misidentifications of historical records. Due to their restriction to single river catchments and declining distributions, Hyriopsis bialata, possibly endemic to Peninsular Malaysia, Ensidens ingallsianus, possibly already extinct in the peninsula, and Rectidens sumatrensis, particularly require conservation attention. Equally, the Pahang, the Perak and the north-western river catchments are of particular conservation value due to the presence of a globally unique freshwater mussel fauna. Statistical relationships of 15 water quality parameters and mussel presence/absence identified acidification and nutrient pollution (eutrophication) as the most important anthropogenic factors threatening freshwater mussel diversity in Peninsular Malaysia. These factors can be linked to atmospheric pollution, deforestation, oil-palm plantations and a lack of functioning waste water treatment, and could be mitigated by establishing riparian buffers and improving waste water treatment for rivers running through agricultural and residential land.

  1. Structure and composition of the septal nacreous layer of Nautilus macromphalus L. (Mollusca, Cephalopoda).

    Science.gov (United States)

    Dauphin, Yannicke

    2006-01-01

    The nacreous layer of Mollusca is the best-known aragonitic structure and is the usual model for biomineralization. However, data are based on less than 10 species. In situ observations of the septal nacreous layer of the cephalopod Nautilus shell has revealed that the tablets are composed of acicular laths. These laths are composed of round nanograins surrounded by an organic sheet. No hole has been observed in the decalcified interlamellar membranes. A set of combined analytical data shows that the organic matrices extracted from the nacreous layer are glycoproteins. In both soluble and insoluble matrices, S amino acids are rare and the soluble organic matrices have a higher sulfated sugar content than the insoluble matrices. It is possible that the observed differences in the structure and composition of the nacreous layers of the outer wall and septa of the Nautilus shell have a dual origin: evolution and functional adaptation. However, we have no appropriate data as yet to answer this question.

  2. Determination of protein-carbonyls and ubiquitin-mediated proteolysis as biomarkers of oxidative-stress in bivalvia and anthozoa

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Stephen Thomas

    2002-07-01

    This study describes the investigation of biomarkers of oxidative-stress in the bivalves Mytilus edulis and Dosinia lupinus, together with host and symbiont tissues of the scleractinian Anthozoa Agaricia agaricites. The biomarkers used were assay of total (via spectrophotometry) and individual (via Western blotting; Oxyblot kit) protein-carbonyls (PC=Os) and content of ubiquitin protein conjugates (UPC) via Western blotting (Bivalvia and Anthozoa) and immunohistochemistry (Anthozoa only). Additional assays for Bivalvia were Trolox equivalent antioxidant capacity (TEAC); and post {gamma}-irradiation survival rates. Experimental stressors for Bivalvia were increased seawater temperature, H{sub 2}O{sub 2} and {sup 60}Co {gamma}-radiation (latter two were used in vivo and in vitro). Comparisons of clean and polluted marine sites are included. Stressors used for Anthozoa were increased solar irradiation concomitant with elevated seawater temperature. Results and conclusions were as follows: individual samples showed considerable variation, pooling of samples improved consistency. Controls for both biomarkers had detectable background levels in each phylum, against which relatively small differences were assessed. In M. edulis, no measurable differences in PC=Os could be determined when elevated seawater temperature or dilute H{sub 2}O{sub 2} (<30% v/v) stressors were used, nor with between-site comparisons. Concentrated H{sub 2}O{sub 2} (30% v/v) produced a small difference. {sup 60}Co {gamma}-radiation produced clearer differences via Oxyblot and spectrophotometric assays. Comparison of four different tissues from the two bivalves found considerable species-specific and tissue-specific differences. Post-irradiation mortality between species was significantly different (<0.001), D. lupinus was more susceptible than M. edulis. TEAC values generally showed a decrease following irradiation (except for digestive gland). UPCs were clearly different between tissues and

  3. The Upper Miocene of the Rostov Dome (Eastern Paratethys: Implication of the chronostratigraphy and bivalvia-based biostratigraphy

    Directory of Open Access Journals (Sweden)

    Ruban Dmitry A.

    2005-01-01

    Full Text Available The Rostov Dome is located in the south of the Russian Platform. In the Late Miocene this area was embraced by the Eastern Paratethys. The implications of a recently developed Neogene chronostratigraphy to the studied area are discussed. The Sarmatian regional stage corresponds to the upper part of the Langhian, the entire Serravalian and the lower part of the Tortonian global stages; the Maeotian regional stage corresponds to the upper part of the Tortonian and the lowermost horizons of the Messinian global stages; the Pontian regional stage corresponds to most of the Messinian and the lowermost Zanclean global stages. A first Bivalvia-based bio-stratigraphic framework is proposed for the territory of the Rostov Dome. Five biozones were established within the Serravalian-Messinian: Tapes vitalianus, Cerastoderma fittoni-Cerastoderma subfittoni, Congeria panticapaea, Congeria amygdaloides navicula and Monodacna pseudocatillus-Prosodacna schirvanica.

  4. Genetic diversity of the biofilm covering Montacuta ferruginosa (Mollusca, bivalvia) as evaluated by denaturing gradient gel electrophoresis analysis and cloning of PCR-Amplified gene fragments coding for 16S rRNA

    NARCIS (Netherlands)

    Gillan, D.C.; Speksnijder, Arjen; Zwart, G.; De Ridder, C.

    1998-01-01

    The shell of the bivalve Montacuta ferruginosa, a symbiont living in the burrow of an echinoid, is covered with a rust- colored biofilm, This biofilm includes different morphotypes of bacteria that are encrusted with a mineral rich in ferric ion and phosphate, The aim of this research was to determi

  5. Freshwater Mussels (Mollusca: Bivalvia: Unionidae) of the Upper Mississippi River: Observations at Selected Sites Within the 9-Foot Navigation Channel Project for the St. Paul District, United States Army Corps of Engineers, 1977 - 1979. Volume II. Appendices.

    Science.gov (United States)

    1980-09-10

    as caz’nata A J T R H Ligwnia recta L. subrost rat a Carunculina parva Lampsilis terea L. higginsi L. radiata siliquoidea L. ovata ventricosa Plagio ...radiata siZiquc’idea 1 1 0.?2 X L. ovata ventricosa 2 2 0. 3 Plagio Za trique tra X Arcidens con fragosus 2 2 0.3 Lasmiqona camptlcnata L. cost ata L

  6. Ciclo gametogênico e comportamento reprodutivo de Iphigenia brasiliana (Mollusca, Bivalvia, Donacidae no estuário do rio Subaé, Baía de Todos os Santos, Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Patrícia P. Silva

    Full Text Available Este estudo teve como objetivos descrever o ciclo gametogênico e o comportamento reprodutivo da população de Iphigenia brasiliana (Lamarck,1818 no estuário do rio Subaé, Baía de Todos os Santos, Bahia. Os bivalves foram coletados de novembro de 2001 a novembro de 2002. Um total de 244 espécimes foi medido (eixo anteroposterior, eviscerado, fixado, desidratado e incluído em parafina. O estudo histológico das gônadas foi realizado através de cortes seriados do tecido gonadal, de 5 mm de espessura, e corados pela HE. O tamanho médio mínimo da primeira maturação sexual (Lpm foi estimado a partir da distribuição das frequências relativas de jovens e adultos, por classe de comprimento dos indivíduos. As frequências relativas dos sexos em cada estádio de desenvolvimento foram consideradas conjuntamente para a análise do comportamento reprodutivo da população, e, em separado, para avaliar a sincronia do ciclo sexual entre machos e fêmeas. Foi observada uma variação de tamanhos entre 9,1 e 66,6 mm, com comprimento médio de 50,2 mm. O estudo não demonstrou diferença significativa entre os tamanhos de machos e fêmeas. Não foi possível observar a diferenciação de sexos em 2,1% dos indivíduos analisados. 51,6% dos indivíduos foram identificados como machos (M e 46,3% como fêmeas (F, não sendo constatadas diferenças significativas entre o número médio de machos e fêmeas, resultando numa proporção de M:F de 1,1:1. O Lpm foi estimado em 11,4 mm, mas apenas ao alcançarem comprimento médio de 34,4 mm, todos os indivíduos foram considerados adultos. Foram caracterizados quatro estádios de evolução do desenvolvimento gonadal em fêmeas e machos. A análise dos diferentes estádios permitiu a observação dos fenômenos de atresia e inversão sexual em fêmeas. O ciclo reprodutivo apresentou eliminação contínua de gametas, com maiores intensidades reprodutivas nos meses de novembro de 2001 a abril de 2002 e, também, no mês de outubro de 2002.

  7. Fresh-Water Mussels (Mollusca: Bivalvia: Unionidae) of the Upper Mississippi River: Observations at Selected Sites within the 9-Foot Channel Navigation Project on Behalf of the U.S. Army.

    Science.gov (United States)

    1978-06-16

    nutrition , respiration) are interrupted or terminated, and the organism will die if it cannot stabilize itself. This is accomplished by burrowing out of...of Lake Texoma, Texas and Oklahoma, after more than 30 years impoundment. Southwestern Naturalist, 22: 235-2S4. Whitfield, R. P. 1885. Brachiopoda and

  8. Dinâmica da População de Anomalocardia brasiliana (Mollusca, Bivalvia, Veneridae no Estuário do Rio Paciência, no Município da Raposa, Estado do Maranhão

    Directory of Open Access Journals (Sweden)

    Juan Jethro Silva Santos

    2014-01-01

    Full Text Available A presença de moluscos no litoral maranhense é significativa, servindo de fonte de renda e subsistência para muitas comunidades. Um exemplo de molusco relacionado com esse potencial é a espécie Anomalocardia brasiliana (Gmelin 1791, que possui grande importância para a população do município da Raposa, na ilha do Maranhão. A presente pesquisa objetivou analisar a dinâmica dessa espécie em lotes naturais do próprio município, nos períodos locais caracterizados como seco e chuvoso. Coletas mensais foram realizadas no período de agosto a dezembro de 2010 e março a junho de 2011, onde foram efetuados levantamentos de informações importantes como variáveis biométricas, fator de condição e densidade. Os resultados encontrados mostraram que os organismos durante todo o período de coleta, exceto o mês de agosto, apresentaram tamanho satisfatório para o consumo, com média acima de 20 mm. Para outro caso, observou-se uma diminuição do fator de condição nos meses de agosto e dezembro, podendo estar relacionado com algum estresse no meio como: período de desova da espécie em questão ou pressão antrópica na região, tendo em vista que, esse organismo sofre forte extração local de forma não sustentável. A densidade dos organismos mostrou-se alta, em termos de biomassa, apresentando uma média de 3,16 toneladas em uma área de 6.007,5 m², que comparada com uma criação de gado extensiva, dependendo do manejo, torna-se mais produtiva, econômica e ecológica.

  9. Genetic diversity of the biofilm covering Montacuta ferruginosa (Mollusca, bivalvia) as evaluated by denaturing gradient gel electrophoresis analysis and cloning of PCR-Amplified gene fragments coding for 16S rRNA

    NARCIS (Netherlands)

    Gillan, D.C.; Speksnijder, Arjen; Zwart, G.; De Ridder, C.

    1998-01-01

    The shell of the bivalve Montacuta ferruginosa, a symbiont living in the burrow of an echinoid, is covered with a rust- colored biofilm, This biofilm includes different morphotypes of bacteria that are encrusted with a mineral rich in ferric ion and phosphate, The aim of this research was to

  10. Perfil de lípidos y ácidos grasos de Perna viridis, mejillón verde (Mollusca: Bivalvia en el oriente venezolano y la costa oeste de Trinidad

    Directory of Open Access Journals (Sweden)

    Tamar Koftayan

    2011-03-01

    Full Text Available Los lípidos totales fueron extraídos, identificados y cuantificados por gravimetría, mediante TLC/FID (sistema Iatroscan. Los ácidos grasos de los lípidos totales, fosfolípidos y triacilgliceroles fueron identificados y cuantificados por cromatografía de gases. Las mayores concentraciones de lípidos totales se presentaron en las muestras de Los Cedros, La Brea y Chaguaramas con valores de 7.92, 7.74 y 7.53%; respectivamente y los valores mínimos en las de La Restinga (6.08%. En la composición lípidica, las muestras de Chacopata presentaron la menor concentración de fosfolípidos (48.86% y los máximos valores de colesterol (38.87% y triacilgliceroles (12.26%, y las muestras de La Esmeralda y Río Caribe exhibieron concentraciones máximas de fosfolípidos (88.71-84.93%, respectivamente y mínimas de colesterol (6.50-4.42%. En los lípidos totales, los ácidos grasos saturados se encontraron entre 15.04 y 65.55%, con máximos en muestras de La Esmeralda y mínimos en Chacopata y los poliinsaturados estuvieron entre 7.80 y 37.18%, con máximos valores en la Brea y mínimos en la Esmeralda. En los fosfolípidos, la concentración de ácidos grasos saturados estuvo entre 38.81 y 48.68% para las muestras de Chaguaramas y Chacopata, respectivamente; los ácidos grasos poliinsaturados se encontraron entre no detectado y 34.51%, con altas concentraciones en muestras de Los Cedros (27.97% y Chaguaramas (34.51%. En los triacilgliceroles, la composición de ácidos grasos saturados variaron entre 14.27 y 53.80%, con baja concentración en Chacopata y alta concentración en La Restinga; los ácidos grasos poliinsaturados estuvieron entre 4.66 y 35.55%, con valores menores en las muestras de Chacopata (4.66% y mayores en Chaguaramas. El consumo frecuente de Perna viridis es recomendable, debido a su alto contenido de fosfolípidos y ácidos grasos insaturados.

  11. COⅠ -BASED DNA BARCODING IN MYTILIDAE SPECIES (MOLLUSCA: BIVALVIA)%基于线粒体COⅠ的DNA条形码技术在贻贝科种类鉴定中的应用

    Institute of Scientific and Technical Information of China (English)

    刘君; 李琪; 孔令锋; 陈军; 郑小东; 于瑞海

    2011-01-01

    DNA条形码(DNA barcoding)技术作为近年来发展起来的物种鉴定的一门新兴技术,已引起越来越多的关注.其原理是利用一段短DNA标准序列(对动物而言一般为线粒体细胞色素c氧化酶亚单位I,mitochondrial cytochrome c oxidase subunit Ⅰ,COⅠ)来实现物种鉴定[1].它的两大主要目的是鉴定已知种和发现新种[2,3].

  12. Vertical distribution, segregation by size and recruitment of the yellow clam Mesodesma mactroides Deshayes, 1854 (Mollusca, Bivalvia, Mesodesmatidae in exposed sandy beaches of the Rio Grande do Sul state, Brazil

    Directory of Open Access Journals (Sweden)

    PEA. Bergonci

    Full Text Available The vertical distribution and the segregation by size of the yellow clam Mesodesma mactroides Deshayes, 1854 were investigated in the intertidal zone and its limits with the lower and upper shores at exposed sandy beaches of Rio Grande do Sul state, Brazil. The gathering was made throughout 12 months; from the Pinhal beach towards the south of the State, in six 15 km equidistant transects, determined through random selection. In these transects, the calculation of 30 consecutive waves was made in order to determine its average amplitude point (P0, from which two points were marked towards the lower shore (P-1 and P-2 and three towards the upper shore (P1, P2 and P3. A 30 by 50 cm cylinder was buried down to the depth of 40 cm, the material was separated with a 0.25 cm mesh and the specimens were quantified and measured in length. The yellow clam presented segregation by size, especially between recruit and adult individuals, with recruits occupying preferably the zones above P0 and adults from this point towards the sea. The young specimens are distributed through all zones, mixed with adult and recruit specimens, which dismisses the hypothesis of segregation by size in function of competition for space and food, once the burying depth is directly proportional to their length. However, the segregation between recruits and adults might be related to the filtering mechanism of the adults, which could ingest the larva, as well as the fact that the recruits, being small and light, are easily transported to the regions above P0. Seasonal migration was observed for adult individuals during winter and spring, probably associated to the reproduction period of the species, being that the peak of recruitment was greater in the end of the winter and the beginning of spring.

  13. Freshwater Mussels (Mollusca: Bivalvia: Unionidae) of the Upper Mississippi River: Observations at Selected Sites Within the 9-Foot Navigation Channel Project for the St. Paul District, United States Army Corps of Engineers, 1977 - 1979. Volume I. Text.

    Science.gov (United States)

    1980-09-10

    Platyhelminthes : Trematoda). This point somewhat coun- ters the idea of this population’s viability. Partially reviewed by Fuller (1974), Nearctic...materials. phylogeny ( phylogenies ), phylogenetic--the history of the evolu- tion of a taxon. PL--United States federal Public Law. plankter (plankters...infestation with flukes, a group of parasitic flatworms ( Platyhelminthes : Trematoda). UM -- Upper Mississippi. Unionicolidae, unionicolid -- the

  14. Annotations to the figured scallops (Mollusca, Bivalvia, Pectinidae) in Gualtieri’s “Index Testarum Conchyliorum”, deposited in the Museo di Storia Naturale e del Territorio at Calci (Pisa, Italy)

    NARCIS (Netherlands)

    Dijkstra, H.H.

    2016-01-01

    An overview is given of the Pectinidae types present in the Gualtieri collection. In Gualtieri (1742) 46 figures (pl. 73 - 15 figs, pl. 74 - 25 figs, pl. 98 – 2 figs, and pl. 99 – 4 figs) show specimens of Pectinidae. Linnaeus (1758) referred to 10 Pectinidae species figured by Gualtieri. Of these,

  15. 我国重要帘蛤科(Veneridae)贝类的16S rRNA序列系统学分析%MOLECULAR PHYLOGENY OF VENERIDAE (MOLLUSCA, BIVALVIA) BASED ON 16S rRNA SEQUENCES

    Institute of Scientific and Technical Information of China (English)

    赵婷; 吴琪; 潘宝平

    2013-01-01

    本文对我国隶属于帘蛤科(Veneridae)10个亚科、17个属、20种贝类的16S rRNA基因片段进行了系统学分析,上述动物的16S rRNA片段长度在438-648bp之间,利用PAUP软件包在对序列比对基础上构建了邻接系统树(NJ)和最大拟然系统树(ML).16S rRNA数据显示,我国帘蛤科贝类由三个主要分支组成,美女蛤亚科中的加夫蛤属(Gafrarium)可能是一个单型属,该属与美女蛤属合并为加夫蛤属比较恰当.帘蛤亚科与雪蛤亚科应属于不连续的分类单元.另外,青蛤亚科与仙女蛤亚科均应作为独立的亚科存在.本文的研究结论与修订后的帘蛤科形态分类观点一致.

  16. O Gênero Pholadomya Sowerby, 1823 (Mollusca: Bivalvia na Formação Jandaíra (Cretáceo Superior, Bacia Potiguar: Implicações Paleoecológicas e Paleogeográficas.

    Directory of Open Access Journals (Sweden)

    Natalia Pereira Benaim

    2008-06-01

    Full Text Available Pholadomya Sowerby, 1823 is an anomalodesmatan bivalve that dispersed during Mesozoic, like other Mollusks,colonizating the South Atlantic shallow seas, between Brazil and Africa. On brazilian Cretaceous the sources ofPholadomya are scarce, occurring in outcrops from Algodões Formation, Gramame Formation and Jandaíra Formation,where occurs the species Pholadomya baixaleitensis. Based on specimens from new outcrops of Jandaíra Formation,a new occurrence of P. cf. adversa and P. baixaleitensis are shown and a new morfotype for the genus is described. Itwas possible to infer that the species studied presented deep endobentonic habits, and burrowed slowly the sediment,probably living their whole life into the same cavity. During Campanian Pholadomya is known from Cameroon, France,Poland, Austria, Germany and other localities in United States of America, occurring in association with other tethyanmollusks. The records of the genus in the marginal equatorial basins enhance the fossil bivalve diversity, and agree withthe hypotesis of a south latitudinal range for the Tethyan Realm during Upper Cretaceous.

  17. 广东海陵岛沿海软体动物的分布%DISTRIBUTION OF CLASS BIVALVIA AND GASTROPODA MOLLUSCA IN THE INSHORE REGIONS OF HAILING ISLAND OF GUANGDONG

    Institute of Scientific and Technical Information of China (English)

    唐以杰; 林炜; 陈明旺; 钟诚; 杜晓捷

    2005-01-01

    对海陵岛沿海软体动物进行了采集调查,共鉴定180种,分属 60科. 其中双壳纲20科86种,占总数47.77%,腹足纲38科92种,占总数51.11%,多板纲1科1种,占总数0.56%,头足纲1科1种,占总数0.56%. 分析表明,其区系特点以南海亚热带-热带种和东海-南海亚热带种为主要成分.

  18. Sequence analysis of 18S rRNA gene of six Veneridae clams (Mollusca: Bivalvia)%6种帘蛤科贝类18S rRNA基因全序列比较分析

    Institute of Scientific and Technical Information of China (English)

    程汉良; 彭永兴; 王芳; 孟学平; 阎斌伦; 董志国

    2008-01-01

    对文蛤(Meretrix meretrix)、青蛤(Cyclina sinensis)、江户布目蛤(Protothaca jedoensis)、薄片镜蛤(Dosinia corrugata)、紫石房蛤(Saxidomus purpuraus)和菲律宾蛤仔(Ruditapes philippinarum)6种帘蛤科(Veneridae)贝类的18S rRNA基因序列进行了PCR扩增并测序,以期获得这一序列的基本特征,评估其种间变异程度,探讨这一序列在种类鉴定和分子系统发育等研究中的应用价值.测序结果表明,文蛤、青蛤、江户布目蛤、薄片镜蛤、紫石房蛤和菲律宾蛤仔18S rRNA基因序列全长分别为1 900bp、1 838bp、1 831 bp、1 831 bp、1 829bp和1 833bp.序列中A、T、C和G碱基的平均含量分别为24.0%、24.0%、24.2%和27.8%.用MEGA软件对6种帘蛤18S rRNA基因全序列进行了分析,对位排列后的总长度1 906bp,其中变异位点210个,简约信息位点28个,si/sv=1.4(46/32).从GenBank下载了7种帘蛤科贝类18S rDNA全序列,与本研究实测的6种帘蛤一起用MegAlign软件对其18S rDNA序列进行了比对,物种间序列相似百分比为88.7%~99.7%.文蛤与其他12物种间序列差异较大,序列差异百分比均超过了10%,其他各物种间序列差异百分比不超过3%.以异韧带亚纲(Anomalodesmata)笋螂目(Pholadomyoida)的Lyonsia floridana和Cardiomya costellata为外群,采用相邻连接法(NJ)和最大简约法(MP)构建了帘蛤科贝类的系统发育树,其拓扑结构显示雪蛤亚科(Chioninae)、帘蛤亚科(Venerinae)和镜蛤亚科(Dosiniinae)的种类首先聚在一起,形成一个聚类簇;缀锦蛤亚科(Tapetinae)、卵蛤亚科(Pitarinae)、仙女蛤亚科(Callistinae)、青蛤亚科(Cyelininae)和文蛤亚科(Meretricinae)的种类先后分别单独聚成一枝;最后所有帘蛤科物种聚为一枝,与外群相区别,说明18S rDNA序列适合作为帘蛤科系统发育研究的分子标记.

  19. Phylogenetic Analysis of Veneridae (Mollusca: Bivalvia) based on Mitochondrial 16S rDNA%基于16S rDNA序列的帘蛤科贝类分子系统发育研究

    Institute of Scientific and Technical Information of China (English)

    程汉良; 周旻纯; 陈冬勤; 彭永兴; 董志国; 易乐飞; 孟学平; 申欣

    2012-01-01

    对21种帘蛤科贝类线粒体16S rRNA基因片段的核苷酸序列进行了分析,以探讨这一序列在种质鉴定、分子系统发育研究中的应用价值.试验结果表明,所有物种扩增片段长度504~642 bp,具有明显的长度多态性,序列A+T含量59.2%~69.0%,明显高于GC含量.物种间共有变异位点447个,其中简约信息位点351个.以16S rDNA片段序列为标记,以中国蛤蜊做外群,构建了帘蛤科贝类的系统发生树,拓扑结构显示,帘蛤科贝类形成3个明显类群,缀锦蛤亚科的13个种形成一个单系群,其结点自展值为93%.第二类群由雪蛤亚科、帘蛤亚科和镜蛤亚科的种类组成,结点自展值为87%.第三类群由仙女蛤亚科、青蛤亚科、楔形蛤亚科和文蛤亚科的种类组成,结点自展值为100%.结合拓扑结构分析和序列比对分析,本研究支持将短文蛤和丽文蛤订为文蛤的同物异名的观点,建议将丽文蛤和短文蛤订为文蛤的地理亚种;支持将薄片镜蛤和Dosinia angulosa订为2个独立种的观点;宜将波纹巴非蛤和织锦巴非蛤订为2个独立种.

  20. 帘蛤科贝类rDNA内转录间隔区序列的研究%Study on Sequences of Ribosomal DNA Internal Transcribed Spacers of Clams Belonging to the Veneridae Family (Mollusca: Bivalvia)

    Institute of Scientific and Technical Information of China (English)

    程汉良; 夏德全; 吴婷婷; 孟学平; 吉红九; 董志国

    2006-01-01

    根据18S rDNA、5.8 S rDNA和28 S rDNA保守序列设计引物,应用聚合酶链式反应(PCR)扩增了文蛤(Meretrix meretrix L.)、青蛤(Cyclina sinensis G.)、硬壳蛤(Mercenaria mercenaria L.)和江户布目蛤(Protothaca jedoensis L.)4种帘蛤科贝类的第一内转录间隔区(ITS1)和第二内转录间隔区(ITS2)序列,并进行了测序.结果表明,文蛤、青蛤、硬壳蛤和江户布目蛤的ITS1扩增产物大小分别为978 bp、663 bp、757 bp和942 bp,GC含量分别为61.55%、60.78%、62.48%和64.86%~64.97%,其中ITS1序列长度分别为900bp、585 bp、679 bp和864 bp,是迄今已报道双壳贝类中变化范围最大的,GC含量分别为61.67%、61.03%、63.03%和65.51%~65.62%,江户布目蛤种内ITS1序列有个体差异;ITS2扩增产物大小分别为644 bp、618~620bp、593 bp和513~514 bp,GC含量分别为61.18%、61.29%~61.81%、62.73%和61.48%~61.60%,其中ITS2序列长度分别为412bp、386~388 bp、361bp和281~282 bp,GC含量分别为65.29%、65.21%~66.06%、67.87%和67.38%~67.62%,青蛤和江户布目蛤种内ITS2序列有个体差异.4种蛤ITS1和ITS2序列种间差异很大,有明显的长度多态性,ITS2种间序列相似度73.0%~89.1%,与ITS1的种间序列相似度48.7%~81.5%相比略高.此外,在4种蛤ITS1和ITS2序列中各发现2个与rRNA加工有关的保守区.通过对ITS1和ITS2序列的组装获得了4种蛤5.8S rRNA基因完整序列,序列长度都是157 bp,GC含量57.96%~58.60%,4种蛤5.8S rRNA基因相对保守,种间序列差异度0-6.0%,共有10个变异位点,其中转换4处,颠换6处,硬壳蛤和江户布目蛤5.8S rRNA基因序列完全相同.以ITS2序列(包含5.8S rRNA和28S rRNA基因部分序列)为标记,调用北极蛤科的Arctica islandica相应序列数据作外群,构建了帘蛤科贝类的系统发育树,其拓扑结构显示江户布目蛤与硬壳蛤亲缘关系最近,青蛤与其他3物种的亲缘关系最远.%The first and second internal transcribed spacer (ITS1 and ITS2) regions of the ribosomal DNA from four species,Meretrix meretrix L., Cyclina sinensis G., Mercenaria mercenaria L., and Protothaca jedoensis L., belonging to the family Veneridae were amplified by PCR and sequenced. The size of the ITS 1 PCR amplification product ranged from 663 bp to 978 bp,with GC contents ranging from 60.78% to 64.97%. The size of the ITS1 sequence ranged from 585 bp to 900 bp, which is the largest range reported thus far in bivalve species, with GC contents ranging from 61.03% to 65.62%. The size of the ITS2 PCR amplification product ranged from 513 bp to 644 bp, with GC contents ranging from 61.29% to 62.73%. The size of the ITS2sequence ranged from 281 bp to 412 bp, with GC contents ranging from 65.21% to 67.87%. Extensive sequence variation and obvious length polymorphisms were noted for both regions in these species, and sequence similarity of ITS2 was higher than that of ITS1 across species. The complete sequences of 5.8S ribosomal RNA gene were obtained by assembling ITS1 and ITS2 sequences,and the sequence length in all species was 157 bp. The phylogenetic tree of Veneridae clams was reconstructed using ITS2-containing partial sequences of both 5.8S and 28S ribosomal DNA as markers and the corresponding sequence information in Arctica islandica as the outgroup. Tree topologies indicated that P. jedoensis shared a close relationship with M. mercenaria and C.sinensis, a distant relationship with other species.

  1. Sequence analysis of the ribosomal DNA internal transcribed spacer region in some clam species (Mollusca: Bivalvia: Veneroida)%几种帘形目贝类rDNA ITS序列的比较

    Institute of Scientific and Technical Information of China (English)

    刘相全; 包振民; 胡景杰; 王师; 方建光; 王如才

    2007-01-01

    扩增并测序了4种帘形目和1种蚶目贝类(外群)核糖体DNA的转录间隔区(ITS)序列.帘形目贝类序列长度在874bp到1466bp之间,GC含量在62%到67%之间,ITS序列在相近的3种帘蛤科贝类之间表现出长度保守性和碱基组成的相似性.采用ITS1,ITS2,以及ITS1与ITS2的连接序列进行聚类,结果表明:2种蛤仔聚为一枝,表现出较近的亲缘关系,帘蛤科的3种贝类聚在一起,再与同属帘形目的缢蛏相聚.研究的结果揭示了帘形目贝类的系统发生关系.

  2. MOLECULAR PHYLOGENY OF TAPETINAE (MOLLUSCA, BIVALVIA) BASED ON MTDNA SEQUENCE%缀锦蛤亚科(Tapetinae)贝类线粒体DNA序列的系统学分析

    Institute of Scientific and Technical Information of China (English)

    潘鹤婷; 袁媛; 吴琪; 张素萍; 潘宝平

    2008-01-01

    采用线粒体16S rRNA和COI序列扩增和测序方法,对隶属于缀锦蛤亚科5属7种动物进行了系统学分析.经Clustal x多重比对和PAuP 4.10 软件分析,得到种间序列的遗传距离并构建了邻接(NJ)系统树.实验数据显示,缀锦蛤亚科为遗传连续的同源类群,其中的浅蛤属(Gomphina)、缀锦蛤属(Tapes)和蛤仔属(Ruditapes)亲缘关系较近,结果与Fischer-Piette等(1971)的缀锦蛤亚科的分类方案基本一致.另外,菲律宾蛤仔R.philippinarum 和杂色蛤仔 R.variegata是蛤仔属在印度洋和太平洋海区的一个组群,尽管两种贝类有明显的重叠分布区和相近的贝壳形态,但二者间的16S rRNA 和COI序列遗传距离均达到了物种间差别.结果支持庄启谦(2001)有关菲律宾蛤仔与杂色蛤仔的形态分类及分布区划分的观点.

  3. Density, size structure, shell orientation and epibiontic colonization of the fan mussel Pinna nobilis L. 1758 (Mollusca: Bivalvia in three contrasting habitats in an estuarine area of Sardinia (W Mediterranean

    Directory of Open Access Journals (Sweden)

    Piero Addis

    2009-03-01

    Full Text Available We investigated the spatial distribution, size structure, shell orientation and valve colonization by epibionts of the endangered Mediterranean bivalve Pinna nobilis in three continuous but different habitats in the Gulf of Oristano (Sardinia, western Mediterranean. The sampling stations chosen were: an estuarine area (E of coastal salt-marshes characterized by unvegetated sea-bottoms; and two areas in a seagrass meadow characterized by an extensive Posidonia oceanica meadow (Mw and patched mixed meadows of P. oceanica and Cymodocea nodosa (Me. We found significant differences in mean densities among stations and the highest value was found in the estuarine area. Shell orientation showed that there was uniform circular distribution of specimens in the Mw station and a unimodal distribution in the Me and E stations, where specimens were set at 0°N and 10°NNE, which is a pattern related to sea drift. Shell epibiosis displayed differences between habitats. The highest valve colonization was in the estuary, with filamentous dark algae and Ostrea edulis reaching almost 90 percent of shell coverage. This study provides new information on habitat preferences and data for assessing local populations of P. nobilis that is useful for its conservation and improving the knowledge of its ecology.

  4. Vertical distribution, segregation by size and recruitment of the yellow clam Mesodesma mactroides Deshayes, 1854 (Mollusca, Bivalvia, Mesodesmatidae) in exposed sandy beaches of the Rio Grande do Sul state, Brazil.

    Science.gov (United States)

    Bergonci, P E A; Thomé, J W

    2008-05-01

    The vertical distribution and the segregation by size of the yellow clam Mesodesma mactroides Deshayes, 1854 were investigated in the intertidal zone and its limits with the lower and upper shores at exposed sandy beaches of Rio Grande do Sul state, Brazil. The gathering was made throughout 12 months; from the Pinhal beach towards the south of the State, in six 15 km equidistant transects, determined through random selection. In these transects, the calculation of 30 consecutive waves was made in order to determine its average amplitude point (P0), from which two points were marked towards the lower shore (P-1 and P-2) and three towards the upper shore (P1, P2 and P3). A 30 by 50 cm cylinder was buried down to the depth of 40 cm, the material was separated with a 0.25 cm mesh and the specimens were quantified and measured in length. The yellow clam presented segregation by size, especially between recruit and adult individuals, with recruits occupying preferably the zones above P0 and adults from this point towards the sea. The young specimens are distributed through all zones, mixed with adult and recruit specimens, which dismisses the hypothesis of segregation by size in function of competition for space and food, once the burying depth is directly proportional to their length. However, the segregation between recruits and adults might be related to the filtering mechanism of the adults, which could ingest the larva, as well as the fact that the recruits, being small and light, are easily transported to the regions above P0. Seasonal migration was observed for adult individuals during winter and spring, probably associated to the reproduction period of the species, being that the peak of recruitment was greater in the end of the winter and the beginning of spring.

  5. Molecular classification and morphological traits of two species of Meretrix ( Mollusca, Bivalvia)%浙江和广西两种文蛤的分子鉴定及形态特征分析

    Institute of Scientific and Technical Information of China (English)

    董迎辉; 姚定余; 林志华; 姚韩韩; 陆荣茂

    2011-01-01

    以文蛤如东群体(RD)和北海群体(BH)为对照群,利用线粒体CO Ⅰ基因序列分析技术对苍南文蛤(CN)和北海白壳文蛤(BW)进行了分子鉴定.结果表明,苍南文蛤和斧文蛤的碱基组成非常相似,通过文蛤属贝类基因序列同源性比对和分子系统聚类分析发现,苍南文蛤CN1、CN2与斧文蛤的同源性分别达到100.0%、99.2%,在依据遗传距离构建的系统进化树上,2个苍南文蛤也与斧文蛤单独聚为一支,据此将苍南文蛤确定为斧文蛤,此结果将斧文蛤的分布区域向北扩展到了浙江南部沿海,修正了现有文献中记载的仅在我国南海诸省分布的说法;而自壳文蛤与其它6种文蛤的基因序列同源性都不高(79.6%~85.3%),在系统进化树上单独分出一支,明显是独立于这些文蛤之外的新种.斧文蛤、白壳文蛤与文蛤群体COⅠ基因的遗传多样性分析显示,文蛤BH群体的变异位点数、单倍型数和核苷酸多样性指数均最大,斧文蛤其次,而白壳文蛤10条基因序列完全相同,未发生任何核苷酸位点变异,说明其遗传多样性很低.应用方差分析和Tukey多重比较,分析了斧文蛤、白壳文蛤与文蛤群体的形态差异,发现斧文蛤的壳长明显大于壳高,且SMW/TW、IW/TW 2个参数与文蛤、白壳文蛤群体差异显著(P<0.05);而白壳文蛤的壳宽指数大、壳型相对膨胀,SW/SL和SW/SH值均最大,与文蛤和斧文蛤群体差异显著(P<0.05).本研究结果可为文蛤属贝类种间鉴别、种质资源保护及系统进化研究提供基础资料.%Although many species of the genus Meretrix are commercially-important cultured bivalves,the taxonomy of Meretrix is still in argument over several discrepancies among scientists in the world. Compared with the groups of Meretrix meretrix (RD & BH) ,two groups of Meretrix clam( CN & BW), collected from Cangnan and Beihai, were phylogenetically analyzed and molecularly classified based on partial sequences of the mitochondrial CO Ⅰ gene. The results indicated that the base sequence of CN group and M. lamarckii with similar composition was the highest in homology of 100.0% and 99.2% .respectively. Phylogenetic NJ and UPGMA tree of Meretrix based on genetic distance also showed that CN1 and CN2 were clustered together with M. lamarckii firstly. Therefore we classified CN group as M. lamarckii, which extended the geographic distribution of M. lamarckii from Taiwan to the southern coast of Zhejiang and corrected the existing document claims. But,the BW group shared low sequence homology(79. 6% -85. 3% ) with other six species of Meretrix and formed much independently cluster beyond among groups. Number of polymorphic sites, indexes of haplotype diversity and nucleotide diversity revealed that the level of genetic diversity from high to low was BH > M. lamarckii > RD > BW. The CO Ⅰ gene sequences of BW group showed very low genetic diversity and no nucleotide variation among 10 individuals. The morphological characters of M. lamarckii, BW and M. meretrix were analyzed using statistical analysis of AMOVA and Tukey' s multiple comparisons for seven morphological traits. Three morphological parameters, including SH/SL,SMW/TW and IW/TW,of M. lamarckii differed significantly with M. meretrix and BW (P < 0.05). BW with relatively expanded shell shape differed significantly with M. meretrix and M. lamarckii in parameters of SW/SL and SW/SH( P <0.05). These results can be expected to provide basic data for the studies of species identification, germplasm conservation and phylogeny.

  6. Die verspreiding en habitat van Chambardia wahlbergi en Chambardia petersi (Bivalvia: Iridinidae in Suid-Afrika

    Directory of Open Access Journals (Sweden)

    Kenné N. de Kock

    2012-03-01

    Full Text Available Die verspreiding en habitat van Chambardia wahlbergi en C. petersi, soos weerspieël deur data in die databasis van die Nasionale Varswaterslakversameling (NVWSV word weergegee en bespreek. Alhoewel die verspreiding van hierdie twee spesies grootliks in die Limpopo- en Mpumalangaprovinsie oorvleuel, kom C. wahlbergi, anders as wat in die literatuur gerapporteer is, ook in die Noordwes- en Vrystaatprovinsie in die wesvloeiende Vaalrivier en in verskeie lokaliteite in die Gautengprovinsie voor. Die meerderheid monsters van beide spesies is in riviere en damme en in watertoestande wat as standhoudend, staande, helder en vars beskryf is, versamel. Multivariansie-analises het temperatuur, hoogte bo seevlak en waterliggame as faktore uitgewys wat betekenisvol tot hul geografiese verspreiding bygedra het. Min is oor die bewaringstatus van hierdie twee spesies bekend, maar die opgedateerde IUCN Rooidata-lys (Seddon et al. 2011 dui albei as nie-bedreig aan. Die meerderheid rekords van beide spesies in die databasis van die NVWSV spruit uit werk tydens die vorige eeu in die Nasionale Krugerwildtuin (NKW. Meer onlangse versamelings deur die outeurs in die NKW dui egter op ‘n afname in die aantal plekke van voorkoms, asook die getalle per versamelpunt wat aan die hand doen dat daar tog rede tot kommer oor hul voortbestaan mag wees. Die feit dat besonder groot eksemplare van C. wahlbergi tot so onlangs soos 2007 meestal toevallig in die Vaalrivier aangetref is, beklemtoon die behoefte om weer omvattende opnames van varswater Mollusca, soortgelyk aan dié van die vorige eeu, van stapel te stuur om die gedokumenteerde verspreiding op te dateer en ook die vordering van eksotiese indringerspesies te moniteer.

  7. Occurrence and settlement of the common shipworm Teredo navalis (Bivalvia: Teredinidae) in Bremerhaven harbours, northern Germany

    Science.gov (United States)

    Tuente, Uda; Piepenburg, Dieter; Spindler, Michael

    2002-06-01

    The shipworm Teredo navalis L. is a xylophagous bivalve mollusc (Bivalvia: Teredinidae) with a long record of being very destructive to wooden ships and harbour buildings. It has been reported from numerous sites at the coasts of both the North and Baltic Seas since the eighteenth century. Here, we document for the first time the occurrence of live adult T. navalis in the harbours of Bremerhaven (Weser estuary, northern Germany). From August to December 1998, various wooden structures (fir floating fenders and pier posts, oak piles) from seven stations in different docks of two harbours (Überseehafen, Fischereihafen) were investigated for the presence and density of live specimens and burrows of T. navalis. The settlement of larval shipworms was studied by exposing experimental fir panels 0.06 m2 in size at 20 stations at water depths between 1 and 2 m for periods of 4 months between July and November. In addition, hydrographic profiles (0-8 m water depth) were obtained at 17 stations in five docks once every month from August to December. Live adult shipworms were found in both fir floating fenders and oak piles at four stations. The largest specimen found was 250 mm long. Shipworm burrows were detected at five stations in almost every wooden structure investigated but their abundances differed significantly: Maximum values were >10,000 m-2 in fir floating fenders, 4,600 m-2 in oak piles and 200 m-2 in fir pier posts. Actual shipworm infestation was detected at three of 16 stations in the exposed fir panels (1-3 burrow holes per panel). Water temperatures and salinities varied considerably during the 4-month investigation period. Temperatures decreased from 19.9°C in August to 0.7°C in December. Salinities ranged from 17.6 in August to 1.1 in November, but only at two lock stations during November and December did value drop below 5, which is regarded as the lethal limit for the larvae of this euryhaline teredinid species. We conclude that T. navalis encounters

  8. Polyplacophora (Mollusca from reef ecosystems and associations with macroalgae on the Coast of Alagoas, Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Monica Dorigo Correia

    2015-08-01

    Full Text Available ABSTRACT Brazilian marine molluscs, especially Gastropoda and Bivalvia, are relatively well studied. However, information on the class Polyplacophora is more scarce, particularly on reef-dwelling forms. This study aimed to qualitatively and quantitatively analyze aspects of polyplacophorans from reef ecosystems and their associations with macroalgae on the coast of Maceió (state of Alagoas, Brazilian Northeast. The study area included five coral reefs at Ipioca, Ponta do Prego, Ponta do Meirim, Riacho Doce and Ponta Verde, as well as two sandstone reefs, located in Guaxuma and Sereia. The samples were obtained by snorkelling along the intertidal and subtidal reef zones to a depth of up to five meters during low tides, between 2009 and 2011. In addition, the chitons associated with three macroalgae of the Ponta Verde coral reef were studied based on collections made over 12 years (from the summer of 1998 to the winter of 2009. Three replicates with an area of 25 cm2 were collected from each of the following species of macroalgal phytals: Amphiroa fragilissima (Rhodophyta, Caulerpa racemosa (Chlorophyta and Dictyota cervicornis (Phaeophyta. A total of 715 individuals (110 juveniles and 605 adults were identified, including Acanthochitona terezae Guerra, 1983, Ischnochiton striolatus (Gray, 1828 and Ischnoplax pectinata (Sowerby II, 1840. Acanthochitona terezae was found for the first time in the area. Ischnochiton striolatus was the most abundant species in the reef ecosystem and in association with macroalgae. The greatest number of individuals of all three polyplacophorans identified (adults and juveniles was found on the phytal A. fragilissima.

  9. Catalogue of the type specimens deposited in the Mollusca Collection of the Museu Nacional / UFRJ, Rio de Janeiro, Brazil.

    Science.gov (United States)

    Pimenta, Alexandre Dias; Monteiro, Júlio César; Barbosa, André Favaretto; Salgado, Norma Campos; Coelho, Arnaldo Campos Dos Santos

    2014-03-20

    A curatorial revision of the type specimens deposited in the Mollusca Collection of the Museu Nacional / UFRJ, Rio de Janeiro, Brazil (MNRJ) revealed the existence of 518 lots of type specimens (holotypes, neotypes, syntypes and paratypes) for 285 names of molluscan taxa from 88 families, including 247 gastropods, 30 bivalves, three cephalopods and five scaphopods. A total of 106 holotypes and one neotype are deposited in the MNRJ. Type material for ten nominal taxa described as being deposited in the MNRJ was not located; the probable reasons are discussed. Some previously published erroneous information about types in the MNRJ is rectified. A total of 37 type specimens are illustrated.

  10. Recovery of marine Conus (Mollusca: Caenogastropoda) from imposex at Rottnest Island, Western Australia, over a quarter of a century.

    Science.gov (United States)

    Wells, Fred E; Keesing, John K; Brearley, Anne

    2017-09-04

    Imposex is a reproductive abnormality in which female snails begin to transform to males, but do not become functional. It was caused by tributyltin (TBT) used as an antifoulant in boat paints. Imposex was first recorded marine snails (Conus) (Mollusca: Caenogastropoda) at Rottnest Island, Western Australia, in January 1991, where 88% of individuals at the west end were affected. Most were at moderate Stages 3 and 4 on a scale of 0 (no affect) to 6 (death). TBT was banned on boats 25m in September 2013. In February 2017 only 4% of Conus had imposex, at Stage 1. Copyright © 2017. Published by Elsevier Ltd.

  11. Evolutionary relationships among squids of the family Gonatidae (Mollusca: Cephalopoda) inferred from three mitochondrial loci.

    Science.gov (United States)

    Lindgren, A R; Katugin, O N; Amezquita, E; Nishiguchi, M K

    2005-07-01

    The oceanic squid family Gonatidae (Mollusca: Cephalopoda) is widely distributed in subpolar and temperate waters, exhibiting behavioral and physiological specializations associated with reproduction. Females of several species undergo muscular degeneration upon maturation; origins of this complex morphogenic change are unknown, hindering our understanding of ecological and morpho-physiological adaptations within the family. To provide further information regarding the evolutionary relationships within Gonatidae, three mitochondrial loci (12S rRNA, 16S rRNA, and cytochrome c oxidase subunit I) were analyzed for 39 individuals representing fourteen gonatid and six outgroup cephalopod species. In addition to elucidating relationships among gonatids, molecular data provided more information than morphological data for problematic specimens. Although some data sets are incongruent or have low nodal support values, combined molecular analysis confirms the presence of gonatid groups previously established by morphological characteristics (i.e., possessing radular teeth in seven longitudinal rows and muscular mantle tissue). These characteristics are basal to taxa possessing radular teeth in five longitudinal rows and less muscular mantle tissue, indicating that the derived forms are those species exhibiting physiological adaptation such as tissue degeneration upon maturation and egg brooding.

  12. Hard and soft anatomy in two genera of Dondersiidae (Mollusca, Aplacophora, Solenogastres).

    Science.gov (United States)

    Scheltema, Amélie H; Schander, Christoffer; Kocot, Kevin M

    2012-06-01

    Phylogenetic relationships and identifications in the aplacophoran taxon Solenogastres (Neomeniomorpha) are in flux largely because descriptions of hard parts--sclerites, radulae, copulatory spicules--and body shape have often not been adequately illustrated or utilized. With easily recognizable and accessible hard parts, descriptions of Solenogastres are of greater use, not just to solenogaster taxonomists, but also to ecologists, paleontologists, and evolutionary biologists. Phylogenetic studies of Aplacophora, Mollusca, and the Lophotrochozoa as a whole, whether morphological or molecular, would be enhanced. As an example, morphologic characters, both isolated hard parts and internal anatomy, are provided for two genera in the Dondersiidae. Five species are described or redescribed and earlier descriptions corrected and enhanced. Three belong to Dondersia: D. festiva Hubrecht, D. incali (Scheltema), and D. namibiensis n. sp., the latter differentiated unambiguously from D. incali only by sclerites and copulatory spicules. Two species belong to Lyratoherpia: L. carinata Salvini-Plawen and L. californica (Heath). Notes are given for other species in Dondersiidae: L. bracteata Salvini-Plawen, Ichthyomenia ichthyodes (Pruvot), and Heathia porosa (Heath). D. indica Stork is synonymized with D. annulata. A cladistic morphological analysis was conducted to examine the utility of hard parts for reconstructing solenogaster phylogeny. Results indicate monophyly of Dondersia and Lyratoherpia as described here.

  13. Two new species of Naticidae (Mollusca ,Gastropoda) from the coast of China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Suping

    2008-01-01

    Two new species of Naticidae (Mollusca,Gastropoda) collected from the coast of China are described:Cryptonaitca huanghaien- sis sp.nov.and Sinum vittatum sp.nov.The morphological characteristics between the new species were described and the relat- ed information was provided.The similarities and differences between the new species and related species were also compared and discussed.The new species Cryptonaitca huanghaiensis differed from Cryptonaitca hirasei and Cryptonaitca andoi in outer shape, operculum and radula.The new species Sinum vittatum is similar to Sinum japonicum (Lischke,1869),but the shell of the for- mer is flat-elliptical in shape,spire very small,slightly convex.While the latter is flat-globular in shape,apex light brown in col- or,without a brown band on the body whorl.The comparison results revealed that Cryptonaitca huanghaiensis and Sinum vittatum were two new species from the coast of China.Specimens studied were obtained from collections in the Marine Biological Museum, Chinese Academy of Sciences.

  14. A review of the non-bulimulid terrestrial Mollusca from the Region of Atacama, northern Chile

    Science.gov (United States)

    Araya, Juan Francisco; Catalán, Ricardo

    2014-01-01

    Abstract Terrestrial mollusca are sparsely studied in Chile and, for the first time, a formal record of the diversity of land snails in northern Chile is reported. Coastal and desertic areas in the Region of Atacama, in the border of the Atacama desert and the Pacific Ocean, were surveyed with the aim to describe the presence and distribution of this poorly known fauna. Of the fourteen species recorded, the geographic distribution records for nine species are extended, and some taxa are recorded for the first time since their original descriptions. All, except one, of the fourteen terrestrial molluscan species occurring in the area are endemic to Chile; they are all terrestrial species, most of them have a restricted geographic distribution, and none of them is currently protected by law. The results reveal that the region of Atacama has one of the most diverse terrestrial snail biodiversity in Chile, ranking only after the Juan Fernandez Archipelago. Distribution records of all the studied species and a taxonomic key are also provided. PMID:24715800

  15. Fases larvais do mexilhão dourado Limnoperna fortunei (Dunker (Mollusca, Bivalvia, Mytilidae na Bacia do Guaíba, Rio Grande do Sul, Brasil Larval stages of the golden mussel Limnoperna fortunei (Dunker (Bivalvia, Mytilidae in Guaíba Basin, Rio Grande do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    Cíntia P. dos Santos

    2005-09-01

    Full Text Available Desde o final de 1998, um pequeno bivalve invasor, o "mexilhão dourado", Limnoperna fortunei (Dunker, 1857, oriundo do sudeste asiático, está presente no sul do Brasil. Foi provavelmente transportado, não intencionalmente, através de água de lastro para a Bacia do Guaíba, Rio Grande do Sul, Brasil. Em nosso meio, este molusco vem causando problemas de "macrofouling" com grandes prejuízos econômicos e danos à fauna e flora. As coletas foram qualitativas e quantitativas quinzenais no período de um ano, no lago Guaíba, Praia do Veludo (30°12'35"S, 51°11'68"W, ao sul do município de Porto Alegre. Utilizou-se rede de plâncton com abertura de malha equivalente a 36 mm, filtrando-se a quantidade de 30 litros de água. Descrevem-se brevemente as diferentes fases larvais com parâmetros do comprimento. Primeiramente reconhece-se um estágio ciliado, desenvolvendo-se em trocófora (comprimento de 80 µm a 125 µm com quatro fases distintas, e valvadas com a larva "D" (120 µm a 150 µm, o veliger de charneira reta (150 µm a 190 µm, o veliger umbonado (190 µm a 220 µm e o pediveliger (220 µm a 250 µm. Quando pós-larvas ou plantígradas (comprimento em torno de 300 µm, começam a secretar o fio de bisso, permitindo a fixação ao substrato. Constatou-se a presença de larvas durante todos os meses amostrados, com picos nos meses de outubro a dezembro.Since the end of 1998 a small invasive bivalve, the golden mussel Limnoperna fortunei (Dunker, 1857, originating from Southeast Asia, is present in Southern Brazil. It was probably brought not intentionally in ballast water to the Guaíba Basin in Rio Grande do Sul State. In this environment, the golden mussel is causing macrofouling very rapidly with grate financial loss and damages to the native fauna and flora. Quali-quantitative samplings twice a month were performed during one year in the Guaíba lake, at Veludo Beach (30°12'35"S, 51°11'68"W southward of the municipality of Porto Alegre. Each time, 30 litters of water were filtered through plankton net with a mash opening of 36 mm. The different larval stages with the length parameters were briefly described. Different stages were recognized: five without valves and four valved. The first one recognized as a ciliated stage develops into the trocophora (length from 80 µm to 125 µm with four distinct stages. The valved stages include: the "D" - shaped (length 120 µm to 150 µm, the straight-hinged veliger (length 150 µm to 190 µm, umbonated-veliger (length 190 µm to 220 µm and pediveliger (length 220 µm to 250 µm. When pos-larvae or plantigrades (length about 300 µm, they secrete the byssus thread that permit fixation on the subtract. Larvae were present during all the samplings with strong October-December peaks.

  16. Gastropoda-Bivalvia Fauna And Neogene-Quaternary Stratigraphy of the Southwest of Dardanelles (Çanakkale-NWAnatolia)

    Science.gov (United States)

    Kapan, Sevinç; Kabasakal, Sinem

    2016-04-01

    Gastropoda-Bivalvia Fauna And Neogene-Quaternary Stratigraphy of the Southwest of Dardanelles (Çanakkale-NWAnatolia) Sevinç KAPAN, Sinem KABASAKAL, Çanakkale Onsekiz Mart University, Engineering Faculty, Geological Engineering Department sevinckapan_yesilyurt@hotmail.com In this study, paleontology and stratigraphy of Neogene and Quaternary units around south of the Dardanelles have been examined using Gastropoda and Bivalvia fauna. In the investigation area, the base of the sediments that belongs to Neogene, consist of the volcanics which are formed with basalts, andesites and tuff. Neogene begins unconformity with basal conglomerate which are formed with basalt and tuff gravels. The measurable thickness of the Neogene sediments is approximately 200meters in total. First fossiliferius level which consist of Lymnocardium (Euxinicardium) nobile Sabba has showed similarities with the Pontian (Late Miocene) fauna of the Eastern Paratethys. The existence of Melanopsis and Psidium species indicate that the basin has been brackish water feeding by fresh water in the Early Pliocene. Theodoxus fluviatilis (Linne), Theodoxus (Calvertia) aff. imbricata Brusina, Theodoxus (Calvertia) licherdopoli scriptus (Stefanescu), Viviparus mammatus (Stefanescu), Valvata (Valavata) sulekiana Brusina, Valvata (Cincinna) crusitensis Fontannes, Hydrobia cf grandis Cobalcescu, Hydrobia ventrosa Monfort, Melanopsis (Melanopsis) cf. bergeroni Stefanescu, , Melanopsis (Melanopsis) sandbergeri rumana Tournouer, Melanopsis (Canthidomus) hybostoma anili Taner, Melanopsis (Canthidomus) hybostoma amaradica Fontannes, Melanopsis (Canthidomus) lanceolata Neumayr, Amphimelania fossariformis (Tournouer), Melanoides tuberculata monolithica (Bukowski), Radix (Radix) peregra (Müller), Planorbarius thiollierei (Michaud), Potamida (Potamida) craiovensis craiovensis (Tournouer), Potamida (Potamida) berbestiensis (Fontannes), Unio pristinus davilai Porumbaru, Unio subexquisitus Jatzko, Anadonta zmaji

  17. The complete sequence and gene organization of the mitochondrial genome of the gadilid scaphopod Siphonondentalium lobatum (Mollusca).

    Science.gov (United States)

    Dreyer, Hermann; Steiner, Gerhard

    2004-05-01

    Comparisons of mitochondrial gene sequences and gene arrangements can be informative for reconstructing high-level phylogenetic relationships. We determined the complete sequence of the mitochondrial genome of Siphonodentalium lobatum, (Mollusca, Scaphopoda). With only 13,932 bases, it is the shortest molluscan mitochondrial genome reported so far. The genome contains the usual 13 protein-coding genes, two rRNA and 22 tRNA genes. The ATPase subunit 8 gene is exceptionally short. Several transfer RNAs show truncated TpsiC arms or DHU arms. The gene arrangement of S. lobatum is markedly different from all other known molluscan mitochondrial genomes and shows low similarity even to an unpublished gene order of a dentaliid scaphopod. Phylogenetic analyses of all available complete molluscan mitochondrial genomes based on amino acid sequences of 11 protein-coding genes yield trees with low support for the basal branches. None of the traditionally accepted molluscan taxa and phylogenies are recovered in all analyses, except for the euthyneuran Gastropoda. S. lobatum appears as the sister taxon to two of the three bivalve species. We conclude that the deep molluscan phylogeny is probably beyond the resolution of mitochondrial protein sequences. Moreover, assessing the phylogenetic signal in gene order data requires a much larger taxon sample than is currently available, given the exceptional diversity of this character set in the Mollusca.

  18. Comparative studies on the morphometry and physiology of European populations of the lagoon specialist Cerastoderma glaucum (Bivalvia

    Directory of Open Access Journals (Sweden)

    Katarzyna Tarnowska

    2009-09-01

    Full Text Available Seasonal changes in the morphometric and physiological parameters of the cockle Cerastoderma glaucum (Bivalvia from the Baltic Sea (GD, the North Sea (LV, and the Mediterranean Sea (BL were investigated. The cockles from GD were much smaller than those from other populations due to osmotic stress. The female to male ratios did not differ significantly from 1:1. The northern populations (GD, LV had a monocyclic reproductive pattern, whereas the southern population (BL seemed to reproduce throughout the year. Seasonal changes in the contents of biochemical components appeared to be correlated with changes in trophic conditions and the reproductive cycle. Protein content was the highest in spring for all the populations. The highest lipid contents and lowest carbohydrate contents were noted in GD and BL in spring, while no marked differences were noted among seasons in LV (probably because the data from both sexes were pooled. Respiration rates in GD were the highest among the populations, which could have been due to osmotic stress. High metabolic rates expressed by high respiration rates in GD and LV in spring and autumn could have resulted from gamete development (in spring and phytoplankton blooms (in spring and autumn.

  19. Chinese pond mussel Sinanodonta woodiana (Lea, 1834 (Bivalvia: origin of the Polish population and GenBank data

    Directory of Open Access Journals (Sweden)

    Marianna Soroka

    2014-05-01

    Full Text Available DDNA sequences of the mitochondrial cox1 gene were analysed in 4 new local populations of Sinanodonta woodiana (Bivalvia in Poland, in the first reported Polish population, and in a population from Hungary. The gene sequences of Polish specimens were identical to those of specimens from Hungary, Italy and Ukraine, but different from those of Romanian specimens (data from GenBank. According to fish farm documentation, S. woodiana had spread in Poland by 2 routes: i direct import of fish infected by glochidia of S. woodiana from Hungary; and ii indirectly, by the major distributor of thermophilous fish in Poland, Gosławice Fish Farm, which started to import Hungarian fish in the 1960s. The genetic analysis and available documentation unambiguously confirm that Polish populations of S. woodiana derive from a source population in Hungary. In addition, we noticed doubtful identification of this species in GenBank data and further research is needed to resolve this problem. 

  20. Reproductive biology of blood cockle Anadara granosa (Bivalvia: Arcidae) in the northern region of the Strait of Malacca

    Science.gov (United States)

    Khalil, Munawar; Yasin, Zulfigar; Hwai, Tan Shau

    2017-02-01

    A study on the reproductive cycle of the blood cockle Anadara granosa (Bivalvia: Arcidae) was conducted at three different areas in the northern region of the Strait of Malacca. A total of 1,920 samples of adult A. granosa (38-71 mm length) were collected from June 2009 until September 2010. Qualitative techniques (gonadal microscopic fresh smear test and histology analysis) as well as quantitative techniques (analysis of condition index and gonadal index) were used to predict monthly gonadal development stages of A. granosa. The gonadal index of A. granosa from Banda Aceh (Indonesia) (r = 0.469, P > 0.05) and Pulau Pinang (Malaysia) (r = 0.123, P > 0.05) did not show any correlation to their condition index, whereas the gonadal index of A. granosa from Lhokseumawe (Indonesia) (r = 0.609, P management and to improve the sustainability practices of the fisheries industry. These findings will provide basic information on the biology of the blood cockle A. granosa for stock management in the region.

  1. Reproductive biology of blood cockle Anadara granosa (Bivalvia: Arcidae) in the northern region of the Strait of Malacca

    Science.gov (United States)

    Khalil, Munawar; Yasin, Zulfigar; Hwai, Tan Shau

    2017-03-01

    A study on the reproductive cycle of the blood cockle Anadara granosa (Bivalvia: Arcidae) was conducted at three different areas in the northern region of the Strait of Malacca. A total of 1,920 samples of adult A. granosa (38-71 mm length) were collected from June 2009 until September 2010. Qualitative techniques (gonadal microscopic fresh smear test and histology analysis) as well as quantitative techniques (analysis of condition index and gonadal index) were used to predict monthly gonadal development stages of A. granosa. The gonadal index of A. granosa from Banda Aceh (Indonesia) ( r = 0.469, P > 0.05) and Pulau Pinang (Malaysia) ( r = 0.123, P > 0.05) did not show any correlation to their condition index, whereas the gonadal index of A. granosa from Lhokseumawe (Indonesia) ( r = 0.609, P principle component analysis (PCA) indicated that A. granosa reproduction was affected by interaction between internal physiological factors and indigenous environmental factors. In all sampling areas, phytoplankton density played a key role in the reproductive cycle in A. granosa. Information on the reproductive biology of this species is essential for species management and to improve the sustainability practices of the fisheries industry. These findings will provide basic information on the biology of the blood cockle A. granosa for stock management in the region.

  2. Purification and characterization of two endo-beta-1,4-glucanases from mollusca, Ampullaria crossean.

    Science.gov (United States)

    Li, Yan-Hong; Guo, Rui; Yin, Qiu-Yu; Ding, Ming; Zhang, Si-Liang; Xu, Gen-Jun; Zhao, Fu-Kun

    2005-10-01

    Two novel endo-beta-1,4-glucanases, EG45 and EG27, were isolated from the gastric juice of mollusca, Ampullaria crossean, by anion exchange, hydrophobic interaction, gel filtration and a second round of anion exchange chromatography. The purified proteins EG45 and EG27 appeared as a single band on sodium dodecylsulfate polyacrylamide gel electrophoresis with a molecular mass of 45 kDa and 27 kDa, respectively. The optimum pH for CMC activity was 5.5 for EG45 and 4.4-4.8 for EG27. The optimum temperature range for EG27 was broad, between 50 degrees and 60 degrees; for EG45 it was 50 degrees. The analysis on the stability of these two endo-beta-1,4-glucanases showed that EG27 was acceptably stable at pH 3.0-11.0 even when the incubation time was prolonged to 24 h at 30 degrees, whereas EG45 remained relatively stable at pH 5.0-8.0. About 85% of the activity of EG27 could be retained upon incubation at 60 degrees for 24 h. However, less than 10% residual activity of EG45 was detected at 50 degrees. Among different kinds of substrates, both enzymes showed a high preference for carboxymethyl cellulose. EG45, in particular, showed a carboxymethyl cellulose hydrolytic activity of 146.5 IU/mg protein. Both enzymes showed low activities to xylan (from oat spelt) and Sigmacell 101, and they were inactive to p-nitrophenyl-beta-D-cellobioside, salicin and starch.

  3. pH-Dependent Stability of EGX, A Multi-functional Cellulase from Mollusca, Ampullaria crossean

    Institute of Scientific and Technical Information of China (English)

    Wen-Ying LI; Ji WANG; Yan-Hong LI; Ming DING; Gen-Jun XU; Lan-Ying LIU; Fu-Kun ZHAO

    2004-01-01

    The cellulase activity and stability of EGX, a multi-functional cellulase previously purified from the mollusca Ampullaria crossean, was systematically studied under different pH. The pH induced conformation and stability change of EGX have been investigated by using the intrinsic fluorescence, ANS fluorescence and CD spectrum. It has been found that the conformation and activity of this cellulase were strongly dependent on the pH. EGX was stable for both the enzyme activity and the conformation from pH 5.6 to pH 7.4. As shown by intrinsic and ANS fluorescence, no red shift of emission maximum occurred and a negligible intensity change was observed at pH 5.6-7.4. The activity of EGX remained about 80% in pH 5.6-7.4 and obviously decreased out of side the pH range. Urea-induced changes in EGX at pH 5.4 and pH 8.0 were measured by intrinsic fluorescence and CD spectrum. At pH 5.4, a significantly red shift of emission maximum occurred when the concentration of urea was 5 M compared to the concentration was 3 M at pH 8.0. The α-helix at pH 5.4 was 40.51% in the absence of urea and 31.04% in the presence of 4 M urea. At pH 8.0 the α-helix was 7.23% in the presence of 4 M urea. The data indicated that EGX was much susceptible to urea-induced unfolding at pH 8.0 and much stable at pH 5.4. The greater pH dependent stability of EGX may allow the enzyme to adequately catalyze the hydrolysis of cellulosic materials under natural or industrial extreme conditions.

  4. Nacre and false nacre (foliated aragonite) in extant monoplacophorans (=Tryblidiida: Mollusca)

    Science.gov (United States)

    Checa, Antonio G.; Ramírez-Rico, Joaquín; González-Segura, Alicia; Sánchez-Navas, Antonio

    2009-01-01

    Extant monoplacophorans (Tryblidiida, Mollusca) have traditionally been reported as having an internal nacreous layer, thus representing the ancestral molluscan condition. The examination of this layer in three species of Neopilinidae ( Rokopella euglypta, Veleropilina zografi, and Micropilina arntzi) reveals that only V. zografi secretes an internal layer of true nacre, which occupies only part of the internal shell surface. The rest of the internal surface of V. zografi and the whole internal surfaces of the other two species examined are covered by a material consisting of lath-like, instead of brick-like, crystals, which are arranged into lamellae. In all cases examined, the crystallographic c-axis in this lamellar material is perpendicular to the surface of laths and the a-axis is parallel to their long dimension. The differences between taxa relate to the frequency of twins, which is much higher in Micropilina. In general, the material is well ordered, particularly towards the margin, where lamellae pile up at a small step size, which is most likely due to processes of crystal competition. Given its morphological resemblance to the foliated calcite of bivalves, we propose the name foliated aragonite for this previously undescribed biomaterial secreted by monoplacophorans. We conclude that the foliated aragonite probably lacks preformed interlamellar membranes and is therefore not a variant of nacre. A review of the existing literature reveals that previous reports of nacre in the group were instead of the aragonitic foliated layer and that our report of nacre in V. zografi is the first undisputed evidence of nacre in monoplacophorans. From the evolutionary viewpoint, the foliated aragonite could easily have been derived from nacre. Assuming that nacre represents the ancestral condition, as in other molluscan classes, it has been replaced by foliated aragonite along the tryblidiidan lineage, although the fossil record does not presently provide evidence as to

  5. The Complete Sequence of the Mitochondrial Genome of the Chamberednautilus (Mollusca: Cephalopoda)

    Energy Technology Data Exchange (ETDEWEB)

    Boore, Jeffrey L.

    2005-12-01

    Background: Mitochondria contain small genomes that arephysically separate from those of nuclei. Their comparison serves as amodel system for understanding the processes of genome evolution.Although complete mitochondrial genome sequences have been reported formore than 600 animals, the taxonomic sampling is highly biased towardvertebrates and arthropods, leaving much of the diversity yetuncharacterized. Results: The mitochondrial genome of a cephalopodmollusk, the Chambered Nautilus, is 16,258 nts in length and 59.5 percentA+T, both values that are typical of animal mitochondrial genomes. Itcontains the 37 genes that are typical for animal mtDNAs, with 15 on oneDNA strand and 22 on the other. The arrangement of these genes can bederived from that of the distantly related Katharina tunicata (Mollusca:Polyplacophora) by a switch in position of two large blocks of genes andtranspositions of four tRNA genes. There is strong skew in thedistribution of nucleotides between the two strands. There are an unusualnumber of non-coding regions and their function, if any, is not known;however, several of these demark abrupt shifts in nucleotide skew,suggesting that they may play roles in transcription and/or replication.One of the non-coding regions contains multiple repeats of a tRNA-likesequence. Some of the tRNA genes appear to overlap on the same strand,but this could be resolved if the polycistron were cleaved at thebeginning of the downstream gene, followed by polyadenylation of theproduct of the upstream gene to form a fully paired structure.Conclusions: Nautilus sp. mtDNA contains an expected gene content thathas experienced few rearrangements since the evolutionary split betweencephalopods and polyplacophorans. It contains an unusual number ofnon-coding regions, especially considering that these otherwise often aregenerated by the same processes that produce gene rearrangements. Thisappears to be yet another case where polyadenylation of mitochondrialtRNAs restores

  6. An SCD gene from the Mollusca and its upregulation in carotenoid-enriched scallops.

    Science.gov (United States)

    Li, Xue; Ning, Xianhui; Dou, Jinzhuang; Yu, Qian; Wang, Shuyue; Zhang, Lingling; Wang, Shi; Hu, Xiaoli; Bao, Zhenmin

    2015-06-10

    Carotenoids are a diverse group of red, orange, and yellow pigments that act as vitamin A precursors and antioxidants. Animals can only obtain carotenoids through their diets. Amongst the carotenoids identified in nature, over one third are of marine origin, but current research on carotenoid absorption in marine species is limited. Bivalves possess an adductor muscle, which is normally white in scallops. However, a new variety of Yesso scallop (Patinopecten yessoensis), the 'Haida golden scallop', can be distinguished by its adductor muscle's orange colour, which is caused by carotenoid accumulation. Studying the genes related to carotenoid accumulation in this scallop could benefit our understanding of the mechanisms underlying carotenoid absorption in marine organisms, and it could further improve scallop breeding for carotenoid content. Stearoyl-CoA desaturase (SCD) is the rate-limiting enzyme in the production of monounsaturated fatty acids, which enhance carotenoid absorption. Here, the full-length cDNA and genomic DNA sequences of the SCD gene from the Yesso scallop (PySCD) were obtained. The PySCD gene consisted of four exons and three introns, and it contained a 990-bp open reading frame encoding 329 amino acids. It was ubiquitously expressed in adult tissues, embryos and larvae of both white Yesso scallops and 'Haida golden' scallops. Although the expression pattern of PySCD in both types of scallops was similar, significantly more PySCD transcripts were detected in the 'Haida golden' scallops than in the white scallops. Elevated PySCD expression was found in tissues including the adductor muscle, digestive gland, and gonad, as well as in veliger larvae. This study represents the first characterisation of an SCD gene from the Mollusca. Our data imply that PySCD functions in multiple biological processes, and it might be involved in carotenoid accumulation.

  7. Homology and homoplasy of swimming behaviors and neural circuits in the Nudipleura (Mollusca, Gastropoda, Opisthobranchia)

    Science.gov (United States)

    Newcomb, James M.; Sakurai, Akira; Lillvis, Joshua L.; Gunaratne, Charuni A.; Katz, Paul S.

    2012-01-01

    How neural circuit evolution relates to behavioral evolution is not well understood. Here the relationship between neural circuits and behavior is explored with respect to the swimming behaviors of the Nudipleura (Mollusca, Gastropoda, Opithobranchia). Nudipleura is a diverse monophyletic clade of sea slugs among which only a small percentage of species can swim. Swimming falls into a limited number of categories, the most prevalent of which are rhythmic left–right body flexions (LR) and rhythmic dorsal–ventral body flexions (DV). The phylogenetic distribution of these behaviors suggests a high degree of homoplasy. The central pattern generator (CPG) underlying DV swimming has been well characterized in Tritonia diomedea and in Pleurobranchaea californica. The CPG for LR swimming has been elucidated in Melibe leonina and Dendronotus iris, which are more closely related. The CPGs for the categorically distinct DV and LR swimming behaviors consist of nonoverlapping sets of homologous identified neurons, whereas the categorically similar behaviors share some homologous identified neurons, although the exact composition of neurons and synapses in the neural circuits differ. The roles played by homologous identified neurons in categorically distinct behaviors differ. However, homologous identified neurons also play different roles even in the swim CPGs of the two LR swimming species. Individual neurons can be multifunctional within a species. Some of those functions are shared across species, whereas others are not. The pattern of use and reuse of homologous neurons in various forms of swimming and other behaviors further demonstrates that the composition of neural circuits influences the evolution of behaviors. PMID:22723353

  8. Volutidae (Mollusca: Gastropoda) of the Lakhra Formation (Earliest Eocene, Sindh, Pakistan): systematics, biostratigraphy and paleobiogeography.

    Science.gov (United States)

    Merle, Didier; Pacaud, Jean-Michel; Métais, Grégoire; Bartolini, Annachiara; Lashari, Rafiq A; Brohi, Imdad A; Solangi, Sarfraz H; Marivaux, Laurent; Welcomme, Jean-Loup

    2014-06-27

    The paleobiodiversity of the Volutidae (Mollusca: Gastropoda) of the Ranikot Group (Sindh, Pakistan) and particularly of the Lakhra Formation (SBZ 5 biozone, Earliest Eocene), is reconsidered on the basis of new material collected during recent field trips. Ten new species are described (Mitreola brohii sp. nov., Lyrischapa vredenburgi sp. nov., L. brevispira sp. nov., Athleta (Volutopupa) citharopsis sp. nov., A. (Volutocorbis) lasharii sp. nov., Volutilithes welcommei sp. nov., V. sindhiensis sp. nov., Pseudaulicina coxi sp. nov., Sindhiluta lakhraensis sp. nov. and Pakiluta solangii sp. nov.) and one species is in open nomenclature (Lyria sp.). Three new genera are described: Lyriopsis gen. nov. [Volutinae, ?Lyriini, type species: Lyriopsis cossmanni (Vredenburg, 1923)], Sindhiluta gen. nov. [Volutilithinae, type species: Sindhiluta lakhraensis n. sp.] and Pakiluta gen. nov. [?Volutodermatinae, type species: Pakiluta solangii n. sp.]. Two new combinations are proposed: Lyriopsis cossmanni (Vredenburg, 1923) comb. nov. and Athleta (Volutopupa) intercrenatus (Cossmann & Pissarro, 1909) comb. nov. Lectotypes are designated for Lyria cossmanni Vredenburg, 1923, L. feddeni Vredenburg, 1923, Volutospina noetlingi Cossmann & Pissarro, 1909, V. intercrenata Cossmann & Pissarro, 1909 and Athleta (Volutocorbis) victoriae Vredenburg, 1923. With 21 species, this volutid fauna is the most diverse recorded from the Tethys Ocean during Earliest Eocene time. The assemblage is characterized by a strong turnover marked by regional speciation and the appearance of many western Tethyan invaders. Although at the species level, the assemblage documents a strong provincialism, at the genus level, the high number of shared genera between Eastern Tethyan and Old World Tethyan realms begins a phase of long-term homogeneity of volutid assemblages from the Tethyan paleobiogeographic province.

  9. Purification and Characterization of Two Endo-β-1,4-glucanases from Mollusca, Ampullaria crossean

    Institute of Scientific and Technical Information of China (English)

    Yan-Hong LI; Rui GUO; Qiu-Yu YIN; Ming DING; Si-Liang ZHANG; Gen-Jun XU; Fu-Kun ZHAO

    2005-01-01

    Two novel endo-β-1,4-glucanases, EG45 and EG27, were isolated from the gastric juice of mollusca, Ampullaria crossean, by anion exchange, hydrophobic interaction, gel filtration and a second round of anion exchange chromatography. The purified proteins EG45 and EG27 appeared as a single band on sodium dodecylsulfate polyacrylamide gel electrophoresis with a molecular mass of 45 kDa and 27 kDa,respectively. The optimum pH for CMC activity was 5.5 for EG45 and 4.4-4.8 for EG27. The optimum temperature range for EG27 was broad, between 50 ℃ and 60 ℃; for EG45 it was 50 ℃. The analysis on the stability of these two endo-β-1,4-glucanases showed that EG27 was acceptably stable at pH 3.0-11.0 even when the incubation time was prolonged to 24 h at 30 ℃, whereas EG45 remained relatively stable at pH 5.0-8.0. About 85% of the activity of EG27 could be retained upon incubation at 60 ℃ for 24 h. However,less than 10% residual activity of EG45 was detected at 50 ℃. Among different kinds of substrates, both enzymes showed a high preference for carboxymethyl cellulose. EG45, in particular, showed a carboxymethyl cellulose hydrolytic activity of 146.5 IU/mg protein. Both enzymes showed low activities to xylan (from oat spelt) and Sigmacell 101, and they were inactive to p-nitrophenyl-β-D-cellobioside, salicin and starch.

  10. Thecosomata e Gymnosomata (Mollusca, Gastropoda da cadeia Fernando de Noronha, Brasil

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    Larrazábal Maria Eduarda de

    2003-01-01

    Full Text Available The Mollusca Pteropoda from Fernando de Noronha Chain Northeastern Brazil were studied in order to know their taxonomy and distribution. Collections were carried out during the I Oceanographical Expedition of the REVIZEE Program (Live Resources of the Economical Exclusive Zone from August to September 1995. The studied area is located between 03°04'S-04°23'S and 32°19'W-36°26'W, comprising 35 stations. Sampling was performed through oblique hauls from 50m depth to surface and from 100 m depth to surface, with a Bongo net (300 and 500 µm mesh size, net diameter: 60 cm, that was equipped with a flow meter. Samples in a total of 99 were preserved, immediately, in buffered 4% formaldehyde. Qualitative and quantitative analyses of the samples were performed based on total sample. The samples were analysed on a counting plate "Bogorov" type under a stereo microscope. A total of 8,258 organisms were identified belonging to: 8 families, 16 genera and 27 species. Limacina inflata (d´Orbigny, 1836 and Creseis virgula (Rang, 1828 were frequent and very frequent in the area outranking among the studied Pteropoda. The total density varied from 2.5 to 3,012.05 org.m-³. Highest richness was registered at the Continental Shelf and Slope with 1two species. The Pteropoda association showed higher differences between day and night collections. Limacina inflata caused this difference due to its higher density at night collections and it was independent of the depth, mesh size and temperature. Creseis virgula had its occurrence, mainly, during day time.

  11. Conchological Variability of Anadara Inaequivalvis (Bivalvia, Arcidae In the Black–Azov Sea Basin

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    Anistratenko V. V.

    2014-10-01

    Full Text Available Конхологическая изменчивость Anadara inaequivalvis (Bivalvia, Arcidae в Азово-Черноморском бассейне. Анистратенко В. В., Анистратенко О. Ю., Халиман И. А. - Показан широкий диа- пазон изменчивости раковины Anadara inaequivalvis (Bruguiere, 1789 - вида-вселенца в Азово- Черноморском бассейне. В изученном материале (более 900 створок выделены 6 основных форм комиссурального просвета раковины, которые, однако, не являются дискретными состояниями. Наличие промежуточных вариантов свидетельствует о плавной (непрерывной изменчивости и принадлежности всех изученных популяций к одному виду. Обсуждается варьирование некото- рых других признаков раковины Anadara: количество и скульптированность рёбер на поверхно- сти створок, количество шевронов на лигаментной площадке, форма замочного края и количество зубов замка. Сопоставление морфологических характеристик раковины Anadara из Чёрного и Азовского морей и A. inaequivalvis из юго-восточной Индии подтверждает, что границы и харак- тер изменчивости моллюсков рода Anadara, обитающих в азово-черноморском бассейне, вполне соответствуют изменчивости A. inaequivalvis из типовой

  12. Neuromuscular development of Aeolidiella stephanieae Valdéz, 2005 (Mollusca, Gastropoda, Nudibranchia

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    Klussmann-Kolb Annette

    2010-01-01

    Full Text Available Abstract Background Studies on the development of the nervous system and the musculature of invertebrates have become more sophisticated and numerous within the last decade and have proven to provide new insights into the evolutionary history of organisms. In order to provide new morphogenetic data on opisthobranch gastropods we investigated the neuromuscular development in the nudibranch Aeolidiella stephanieae Valdéz, 2005 using immunocytochemistry as well as F-actin labelling in conjunction with confocal laser scanning microscopy (cLSM. Results The ontogenetic development of Aeolidiella stephanieae can be subdivided into 8 stages, each recognisable by characteristic morphological and behavioural features as well as specific characters of the nervous system and the muscular system, respectively. The larval nervous system of A. stephanieae includes an apical organ, developing central ganglia, and peripheral neurons associated with the velum, foot and posterior, visceral part of the larva. The first serotonergic and FMRFamidergic neural structures appear in the apical organ that exhibits an array of three sensory, flask-shaped and two non-sensory, round neurons, which altogether disappear prior to metamorphosis. The postmetamorphic central nervous system (CNS becomes concentrated, and the rhinophoral ganglia develop together with the anlage of the future rhinophores whereas oral tentacle ganglia are not found. The myogenesis in A. stephanieae begins with the larval retractor muscle followed by the accessory larval retractor muscle, the velar or prototroch muscles and the pedal retractors that all together degenerate during metamorphosis, and the adult muscle complex forms de novo. Conclusions Aeolidiella stephanieae comprises features of the larval and postmetamorphic nervous as well as muscular system that represent the ground plan of the Mollusca or even the Trochozoa (e. g. presence of the prototrochal or velar muscle ring. On the one hand

  13. The complete sequence of the mitochondrial genome of Nautilus macromphalus (Mollusca: Cephalopoda

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    Boore Jeffrey L

    2006-07-01

    Full Text Available Abstract Background Mitochondria contain small genomes that are physically separate from those of nuclei. Their comparison serves as a model system for understanding the processes of genome evolution. Although complete mitochondrial genome sequences have been reported for more than 600 animals, the taxonomic sampling is highly biased toward vertebrates and arthropods, leaving much of the diversity yet uncharacterized. Results The mitochondrial genome of the bellybutton nautilus, Nautilus macromphalus, a cephalopod mollusk, is 16,258 nts in length and 59.5% A+T, both values that are typical of animal mitochondrial genomes. It contains the 37 genes that are almost universally found in animal mtDNAs, with 15 on one DNA strand and 22 on the other. The arrangement of these genes can be derived from that of the distantly related Katharina tunicata (Mollusca: Polyplacophora by a switch in position of two large blocks of genes and transpositions of four tRNA genes. There is strong skew in the distribution of nucleotides between the two strands, and analysis of this yields insight into modes of transcription and replication. There is an unusual number of non-coding regions and their function, if any, is not known; however, several of these demark abrupt shifts in nucleotide skew, and there are several identical sequence elements at these junctions, suggesting that they may play roles in transcription and/or replication. One of the non-coding regions contains multiple repeats of a tRNA-like sequence. Some of the tRNA genes appear to overlap on the same strand, but this could be resolved if the polycistron were cleaved at the beginning of the downstream gene, followed by polyadenylation of the product of the upstream gene to form a fully paired structure. Conclusion Nautilus macromphalus mtDNA contains an expected gene content that has experienced few rearrangements since the evolutionary split between cephalopods and polyplacophorans. It contains an

  14. Population dynamics of freshwater oyster Etheria elliptica (Bivalvia: Etheriidae in the Pendjari River (Benin-Western Africa

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    Akélé G.D.

    2015-01-01

    Full Text Available Etheria elliptica (Bivalvia: Etheriidae is the only freshwater oyster occurring in Africa. The current study provides the first data on the population structure, growth, age, mortality and exploitation status of this species in the Pendjari River. E. elliptica length-frequency data were collected monthly from January to December 2009 and analyzed with FiSAT software. Population parameters including the asymptotic length (L∞ and growth coefficient (K were assessed to evaluate the stock status. The recruitment pattern was modeled with a FiSAT routine. The asymptotic length (L∞ was 14.75 cm, while the growth coefficient (K was 0.38 year-1. The growth performance index (ø′ reached 1.92. Specimens of Etheria elliptica reached a mean size of 4.66 cm and 6.41 cm at the end of one year and 1.5 years, respectively. We estimated total mortality (Z, natural mortality (M and fishing mortality (F to be 2.90 year-1, 1.16 year-1 and 1.74 year-1, respectively. The recruitment pattern was continuous over the year with one major peak event during the rainy season (July. The exploitation rate (E = 0.60 revealed that the freshwater oyster was probably facing overexploitation due to lack of a minimum limit size and also due to an increase in the harvesting effort. Therefore, efficient management methods were urgently required to conserve the species. The return of empty shells into the water to increase the recruitment surface, rotation planning among harvesting sites and the imposition of a minimum limit size were recommendations made in order to ensure the sustainable exploitation of wild stocks.

  15. Mitochondrial genomes and Doubly Uniparental Inheritance: new insights from Musculista senhousia sex-linked mitochondrial DNAs (Bivalvia Mytilidae

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    Milani Liliana

    2011-09-01

    Full Text Available Abstract Background Doubly Uniparental Inheritance (DUI is a fascinating exception to matrilinear inheritance of mitochondrial DNA (mtDNA. Species with DUI are characterized by two distinct mtDNAs that are inherited either through females (F-mtDNA or through males (M-mtDNA. DUI sex-linked mitochondrial genomes share several unusual features, such as additional protein coding genes and unusual gene duplications/structures, which have been related to the functionality of DUI. Recently, new evidence for DUI was found in the mytilid bivalve Musculista senhousia. This paper describes the complete sex-linked mitochondrial genomes of this species. Results Our analysis highlights that both M and F mtDNAs share roughly the same gene content and order, but with some remarkable differences. The Musculista sex-linked mtDNAs have differently organized putative control regions (CR, which include repeats and palindromic motifs, thought to provide sites for DNA-binding proteins involved in the transcriptional machinery. Moreover, in male mtDNA, two cox2 genes were found, one (M-cox2b 123bp longer. Conclusions The complete mtDNA genome characterization of DUI bivalves is the first step to unravel the complex genetic signals allowing Doubly Uniparental Inheritance, and the evolutionary implications of such an unusual transmission route in mitochondrial genome evolution in Bivalvia. The observed redundancy of the palindromic motifs in Musculista M-mtDNA may have a role on the process by which sperm mtDNA becomes dominant or exclusive of the male germline of DUI species. Moreover, the duplicated M-COX2b gene may have a different, still unknown, function related to DUI, in accordance to what has been already proposed for other DUI species in which a similar cox2 extension has been hypothesized to be a tag for male mitochondria.

  16. De novo assembly and characterization of two transcriptomes reveal multiple light-mediated functions in the scallop eye (Bivalvia: Pectinidae.

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    Autum N Pairett

    Full Text Available BACKGROUND: The eye has evolved across 13 separate lineages of molluscs. Yet, there have been very few studies examining the molecular machinary underlying eye function of this group, which is due, in part, to a lack of genomic resources. The scallop (Bivalvia: Pectinidae represents a compeling molluscan model to study photoreception due to its morphologically novel and separately evolved mirror-type eye. We sequenced the adult eye transcriptome of two scallop species to: 1 identify the phototransduction pathway components; 2 identify any additional light detection functions; and 3 test the hypothesis that molluscs possess genes not found in other animal lineages. RESULTS: A total of 3,039 contigs from the bay scallop, Argopecten irradians and 26,395 contigs from the sea scallop, Placopecten magellanicus were produced by 454 sequencing. Targeted BLAST searches and functional annotation using Gene Ontology (GO terms and KEGG pathways identified transcripts from three light detection systems: two phototransduction pathways and the circadian clock, a previously unrecognized function of the scallop eye. By comparing the scallop transcriptomes to molluscan and non-molluscan genomes, we discovered that a large proportion of the transcripts (7,776 sequences may be specific to the scallop lineage. Nearly one-third of these contain transmembrane protein domains, suggesting these unannotated transcripts may be sensory receptors. CONCLUSIONS: Our data provide the most comprehensive transcriptomic resource currently available from a single molluscan eye type. Candidate genes potentially involved in sensory reception were identified, and are worthy of further investigation. This resource, combined with recent phylogenetic and genomic data, provides a strong foundation for future investigations of the function and evolution of molluscan photosensory systems in this morphologically and taxonomically diverse phylum.

  17. On some Indo-Pacific boring endolithic Bivalvia species introduced into the Mediterranean Sea with their host – spread of Sphenia rueppelli A. Adams, 1850

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    A. ZENETOS

    2012-12-01

    Full Text Available The study of the endolithic molluscs found on/in living alien Spondylusshells collected in the Gulf of Iskenderun (Turkey brought to light three more alien bivalvia species namely Petricola hemprichi, Gastrochaena cymbium and Sphenia rueppelli. The presence of Sphenia rueppellideserves attention as it constitutes the first record of this species as living in the Mediterranean Sea. The definitive establishment and spreading of these bivalves in the basin seems to be also attested by careful analysis of specimens sampled in other southern Turkish localities and previously retained in local private collections. The present records raise some questions on the vector of arrival of the species in the Mediterranean Sea that could be strictly connected with their hosts.

  18. New Mediterranean Biodiversity Records (June 2012

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    A. NICOLAIDOU

    2012-12-01

    Full Text Available The present work reports on the extended distribution of nineteen species in the Mediterranean. These are: Upeneus pori(Fish:Turkey, Bursatella leachii (Mollusca, Opisthobranchia: eastern coast of Spain, Sparisoma cretense (Fish: Ionian coastof Greece, Pseudobryopsis myura (Chlorophyta: Turkey, Aplysia dactylomela (Mollusca, Opisthobranchia: Karpathos island,and Kyklades Archipelago, Greece, Asparagopsis armata and Botryocladia madagascariensis (Rhodophyta: South Peloponnesos,Greece, Oxynotus centrina (Fish: Greece, Caulerpa racemosa var. cylindracea (Chlorophyta , Stypopodium schimperi(Phaeophyta Siganus luridus and Stephanolepis diaspros (Fish Percnon gibbesi (Decapoda, Brachyura (Kyklades Archipelago,Greece, Cerithium scabridum (Mollusca, Prosobranchia: Anavissos: Greece and Cerithium renovatum (Mollusca, Prosobranchia:N. Κriti, Cassiopea andromeda (Scyphomedusa: Rhodos Island, Greece, Abra tenuis (Mollusca Bivalvia: VouliagmeniLake, Greece Lagocephalus lagocephalus (Fish: Calabrian coast, Italy and Plocamopherus ocellatus (Mollusca, Opisthobranchia:İskenderun Bay, Turkey.

  19. Species composition and distribution of medical mollusca in Shanghai City%上海市医学贝类物种组成及其分布

    Institute of Scientific and Technical Information of China (English)

    郭云海; 吕山; 顾文彪; 刘和香; 吴缨; 张仪

    2015-01-01

    Objective To investigate the species diversity and distribution of medical mollusca in Shanghai City. Methods From August 2012 to October 2013,all kinds of habitats in 8 districts and counties in Shanghai City,namely Jiading,Qingpu, Baoshan,Minhang,Songjiang,Jinshan,Chongming,Pudong,were selected for the field survey according to the distribution characteristics of the river system,and all the specimens of medical mollusca in the investigation sites were collected and classi⁃fied by morphological identification. Meanwhile,the species composition,habitats as well as the fauna of the medical mollusca collected were analyzed. Results A total of 5 211 specimens were collected,which belonged to 2 classes,14 families,18 gen⁃era and 25 species,including Oncomelania hupensis hupensis,Pomacea canaliculata,Parafossarulus striatulus,Alocinma longicornis,Physa acuta,Galba pervia,Hippeutis cantori,etc. The species numbers of medical mollusca in Chongming,Jin⁃shan,Pudong new area and Qingpu districts(counties)were 22,22,21 and 20,respectively,which were more than those of other areas. The habitat analysis suggested that the species numbers in the river and wetland were the most,both of which were 14 species. The main faunas of the medical mollusca in Shanghai were the cosmopolitan and oriental species. Conclusions The freshwater gastropod species are paucity in Shanghai City,but almost of them can be served as the intermediate hosts of certain parasites to transmit snail⁃related parasitic diseases,so the surveillance of medical mollusca should be strengthened.%目的:调查上海市医学贝类物种多样性及其分布。方法于2012年8月至2013年10月,根据水系分布特点,对上海市嘉定、青浦、宝山、闵行、松江、金山、崇明岛和浦东新区等8个区(县)各类生境进行现场抽样调查,采集医学贝类标本。所获标本经形态学鉴定分类,并对物种组成、生境及区系分布等进行

  20. Identification of several cytoplasmic HSP70 genes from the Mediterranean mussel (Mytilus galloprovincialis) and their long-term evolution in Mollusca and Metazoa.

    Science.gov (United States)

    Kourtidis, Antonis; Drosopoulou, Elena; Nikolaidis, Nikolas; Hatzi, Vasiliki I; Chintiroglou, Chariton C; Scouras, Zacharias G

    2006-04-01

    The HSP70 protein family consists one of the most conserved and important systems for cellular homeostasis under both stress and physiological conditions. The genes of this family are poorly studied in Mollusca, which is the second largest metazoan phylum. To study these genes in Mollusca, we have isolated and identified five HSP70 genes from Mytilus galloprovincialis (Mediterranean mussel) and investigated their short-term evolution within Mollusca and their long-term evolution within Metazoa. Both sequence and phylogenetic analyses suggested that the isolated genes belong to the cytoplasmic (CYT) group of the HSP70 genes. Two of these genes probably represent cognates, whereas the remaining probably represent heat-inducible genes. Phylogenetic analysis including several molluscan CYT HSP70s reveals that the cognate genes in two species have very similar sequences and form intraspecies phylogenetic clades, differently from most metazoan cognate genes studied thus far, implying either recent gene duplications or concerted evolution. The M. galloprovincialis heat-inducible genes show intraspecies phylogenetic clustering, which in combination with the higher amino acid than nucleotide identity suggests that both gene conversion and purifying selection should be responsible for their sequence homogenization. Phylogenetic analysis including several metazoan HSP70s suggests that at least two types of CYT genes were present in the common ancestor of vertebrates and invertebrates, the first giving birth to the heat-inducible genes of invertebrates, whereas the other to both the heat-inducible genes of vertebrates and the cognate genes of all metazoans. These analyses also suggest that inducible and cognate genes seem to undergo divergent evolution.

  1. Species Composition and Fauna of Mollusca in Seven Star Islands%七星列岛软体动物种类组成与区系

    Institute of Scientific and Technical Information of China (English)

    余海; 阙伟伟; 陆京明; 周化斌; 张永普

    2016-01-01

    The resources of mollusca in Seven Star islands are investigated during November 2012 to November 2013 and a total of 102 species of Mollusca are collected. Among them, 61 belong to Gastropods, 25 to Bivalves, 9 to Cephalopda, 6 to Polyplacophora and 1 to Scaphopoda. The mollusca is divided into the following four groups as far as the fauna:34 hiroatsu and widespread species are distributed from the coastal China;56 sub-tropical species in the East China Sea and South China Sea; 9 tropical species in the South China Sea; 2 warm temperate species in the Bohai Sea, Yellow Sea and Northern East China Sea and 1 species is undefined. The faunal character pertains to Chinese-Japanese sub-region, subordinating to Indo-Western-Pacific realm.%2012年11月至2013年11月期间,对七星列岛的软体动物种类进行调查,共发现软体动物102种,其中腹足纲61种,双壳纲25种,头足纲9种,多板纲6种,掘足纲1种。就区系而言,分布于我国沿岸的广温广布种34种,分布于东海和南海的亚热带种56种,南海的热带种9种,渤、黄海延伸到东海北部的暖温带种2种,1种未确定。区系性质属于印度-西太平洋区的中国-日本亚区。

  2. Contribució a l’estudi dels mol·luscs terrestres (Mollusca, Gastropoda del Parc de la Serralada Litoral (Barcelona

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    Bros, V.

    2013-01-01

    Full Text Available Contribution to the study of terrestrial molluscs (Mollusca, Gastropoda Serralada LitoralPark (BarcelonaThe population of molluscs in Serralada Litoral Park (Barcelona, NE Iberian peninsula was assessed, contributing to the conservation plan. A wildlife inventory was conducted based on fieldwork and literature. Gastropod communities in various natural environments and conchological species of interest for conservation are also described. Several environmental aspects that determine the distribution and abundance of snails are discussed and management measures to meet their ecological requirements are suggested.

  3. Astronotus ocellatus (Cichlidae: Pisces and Macropodus opercularis (Anabatidae: Pisces as predators of immature Aedes fluviatilis (Diptera: Culicidae and Biomphalaria glabrata (Mollusca: Planorbidae

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    Rotraut A. G. B. Consoli

    1991-12-01

    Full Text Available Two fish species, Astronotus ocellatus (Cichlidae and Macropodus opercularis (Anabatidae were tested for predacious behavior toward immature mosquitoes (Aedes fluviatili9s, Diptera: Culicidae and schistosomiasis snail hosts (Biomphalaria glabrata, Mollusca: Planorbidae, in the presence or absence of non-living food and laboratory conditions. A. ocellatus, a species indigenous to Brazil, was a very efficient predator of both organisms (alpha=1,05; M. operculatis, an exotic species, preyed well on immature mosquitoes, but small snails and snail egg-masses were ingested only irregulary. Both fish species seemed to prefer live to non-living food.

  4. Molecular inference of phylogenetic relationships among Decapodiformes (Mollusca: Cephalopoda) with special focus on the squid order Oegopsida.

    Science.gov (United States)

    Lindgren, Annie R

    2010-07-01

    Squids, cuttlefish and bobtail squids comprise the molluscan superorder Decapodiformes (Mollusca: Cephalopoda). Although these animals exemplify the morphological and ecological diversity seen in Cephalopoda, no previous study has focused resolving decapodiform relationships, particularly within Oegopsida, a large order comprised of pelagic squid. To further clarify the phylogenetic history of Decapodiformes, and Oegopsida in particular, molecular data for five genes (18S rRNA, 28S rRNA, Histone H3, 16S rRNA, COI) was collected for 90 taxa representing all major lineages and families and evaluated using parsimony, likelihood, and Bayesian analysis. Although ordinal relationships were sensitive to analytical method, several conclusions can be inferred: the pelagic order Myopsida is closely related to the benthic sepioids, whose relationships were ambiguous, and Bathyteuthoidea is distinct from Oegopsida. Within Oegopsida several clades are consistently recovered, some with previous morphological support (e.g. chiroteuthid, lepidoteuthid, histioteuthid families) while others suggest novel relationships (e.g. Architeuthidae+Neoteuthidae). This study, with its broad coverage of taxa, provides the first in-depth analysis of Decapodiformes with special focus on the morphologically and biogeographically diverse Oegopsida, confirms several sister-taxon relationships, and provides new hypotheses of cephalopod evolution in the open ocean.

  5. Biochemical profile of Achatina fulica (Mollusca: Gastropoda) after infection by different parasitic loads of Angiostrongylus cantonensis (Nematoda, Metastrongylidae).

    Science.gov (United States)

    Tunholi-Alves, Vinícius Menezes; Tunholi, Victor Menezes; Amaral, Ludimila Santos; Mota, Esther Maria; Maldonado Júnior, Arnaldo; Pinheiro, Jairo; Garcia, Juberlan

    2015-01-01

    The effect of experimental infection by different parasitic loads of Angiostrongylus cantonensis (Nematode, Metastrongylidae) on the activities of the aminotransferases and concentration of total proteins, uric acid and urea in the hemolymph of Achatina fulica (Mollusca, Gastropoda) were investigated. There was a significant decrease in the concentration of total proteins in the exposed snails to 5000 or more larvae. This change was accompanied by an increase in the concentrations of urea and uric acid in the hemolymph, suggesting a higher rate of deamination of the amino acids. Besides this, variations in the activities of the aminotransferases were also observed, with the highest values recorded in the groups exposed to greater parasite load. These results suggest an increase in the use of total proteins, since there was increased formation of nitrogenous catabolites, in conformity with an increase in the aminotransferase activities. Infection was verified by the fact that L3 larvae recovered from the snails was proportion to the exposure dose of L1 larvae. Histopathological results also indicated presence of an inflammatory cell infiltrate, favoring an increase of both transaminases.

  6. Assessing metal contamination from construction and demolition (C&D) waste used to infill wetlands: using Deroceras reticulatum (Mollusca: Gastropoda).

    Science.gov (United States)

    Staunton, John A; Mc Donnell, Rory J; Gormally, Michael J; Williams, Chris D; Henry, Tiernan; Morrison, Liam

    2014-11-01

    Large quantities of construction and demolition waste (C&D) are produced globally every year, with little known about potential environmental impacts. In the present study, the slug, Deroceras reticulatum (Mollusca: Gastropoda) was used as the first biomonitor of metals (Ag, As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Se, Ti, Tl, V and Zn) on wetlands post infilling with construction and demolition (C&D) waste. The bioaccumulation of As, Ba, Cd, Co, Sb, Se and Tl were found to be significantly elevated in slugs collected on C&D waste when compared to unimproved pastures (control sites), while Mo, Se and Sr had significantly higher concentrations in slugs collected on C&D waste when compared to known contaminated sites (mining locations), indicating the potential hazardous nature of C&D waste to biota. Identifying exact sources for these metals within the waste can be problematic, due to its heterogenic nature. Biomonitors are a useful tool for future monitoring and impact studies, facilitating policy makers and regulations in other countries regarding C&D waste infill. In addition, improving separation of C&D waste to allow increased reuse and recycling is likely to be effective in reducing the volume of waste being used as infill, subsequently decreasing potential metal contamination.

  7. Caracterización molecular de diferentes morfos de Melanoides tuberculata (Mollusca: Thiaridae mediante microsatélites

    Directory of Open Access Journals (Sweden)

    David P.

    2001-06-01

    Full Text Available M. tuberculataes un molusco asiático invasor de ecosistemas tropicales y subtropicales. En Amé-rica, su uso como control biológico ha sido probado en el desplazamiento de poblaciones deBiomphalaria spp. (Mollusca: Planorbidae, hospedadores intermediarios de Schistosoma mansoni(Trematoda: Digenea. A su vez, M. tuberculataes una especie que presenta gran plasticidad feno-típica, reconociéndose varias entidades morfológicas (morfos a lo largo de su rango de distribu-ción. Este trabajo pretende identificar la combinación de alelos microsatelitales característicos de10 morfos americanos. En este orden de ideas, se realizó una extracción de ADN con bufferValsecchi y baño María 90-95ºC (5-15’; se hizo una PCR utilizando primers específicos para M.tuberculata, y finalmente un análisis de secuencias microsatelitales con un secuenciador automá-tico.

  8. Annotated type catalogue of the Orthalicoidea (Mollusca, Gastropoda in the Museum für Naturkunde, Berlin

    Directory of Open Access Journals (Sweden)

    Abraham Breure

    2013-03-01

    Full Text Available The type status is described of 96 taxa classified within the superfamily Orthalicoidea and present in the Mollusca collection of the Museum für Naturkunde der Humboldt-Universität zu Berlin. Lectotypes are designated for the following taxa: Orthalicus elegans Rolle, 1895; Bulimus maranhonensis Albers, 1854; Orthalicus nobilis Rolle, 1895; Orthalichus tricinctus Martens, 1893. Orthalicus sphinx tresmariae is introduced as new name for Zebra sphinx turrita Strebel, 1909, not Z. quagga turrita Strebel, 1909. The following synonyms are established: Zebra crosseifischeri Strebel, 1909 = Orthalicus princeps fischeri Martens, 1893; Orthalicus isabellinus Martens, 1873 = O. bensoni (Reeve, 1849; Zebra zoniferus naesiotes Strebel, 1909 = Orthalicus undatus (Bruguière, 1789; Porphyrobaphe (Myiorthalicus dennisoni pallida Strebel, 1909 = Hemibulimus dennisoni (Reeve, 1848; Zebra delphinus pumilio Strebel, 1909 = Orthalicus delphinus (Strebel, 1909; Orthalicus (Laeorthalicus reginaeformis Strebel, 1909 = Corona perversa (Swainson, 1821; Bulimus (Eurytus corticosus Sowerby III, 1895 = Plekocheilus (Eurytus stuebeli Martens, 1885. The taxon Bulimus (Eudioptus psidii Martens, 1877 is now placed within the family Sagdidae, tentatively in the genus Platysuccinea. Appendices are included with an index to all the types of Orthalicoidea extant (including those listed by Köhler 2007 and a partial list of letters present in the correspondence archives.

  9. ON THE PALEOFAUNA INVERTEBRATES (MOLLUSCA, ARTROPODA; INSECTA OF DIATOMITE DEPOSITS OF SHAMB–1 LOCALITY (SISIAN SUITE, EARLY PLEISTOCENE, ARMENIA

    Directory of Open Access Journals (Sweden)

    М. A. Маrjanyan

    2016-01-01

    Full Text Available Aim. The study of fossil insects from diatomaceous sediments of Shamb-1 locality of Sisian Suite (Early Pleistocene. The collection of fossils plants and animals of Institute of Botany of NAS RA and authors' findings served as material for study.Methods. The material is processed and prepared for study by conventional methods in paleontology for prints and fossils of insects from diatomaceous sediments. There are 654 samples studied: 2 samples were with mollusks’ imprints and 652 samples with imprints of insects, from which preserved marks on 291samples allowed to identify them up to order, family, genus and species.Results. The studied material refers to the Mollusca and Arthropoda (Insecta types. Insects are represented by species of orders Orthoptera (2 fam., Homoptera (1 fam., Heteroptera (2 fam., Coleoptera (15 fam., Hymenoptera (2 fam., Diptera (1 fam.. Coleopteras dominate among them and are presented with following species of the family – Carabidae, Dytiscidae, Hydrophilidae, Histeridae, Staphylinidae, Silphidae, Elateridae, Buprestidae, Lampyridae, Scarabaeidae, Chrysomelidae, Tenebrionidae, Coccinellidae, Cerambycidae, Curculionidae.Main conclusions. An analysis of the taxonomic composition of paleofauna was done, which corresponds to the recent fauna and with considering modern ecological characteristics of systematical groups and species. In the investigated location of Shamb-1 a version is suggested about the palaeolandscapes and palaeoclimate in the Early Pleistocene.

  10. A review of the non-bulimulid terrestrial Mollusca from the Region of Atacama, northern Chile

    Directory of Open Access Journals (Sweden)

    Juan Francisco Araya

    2014-04-01

    Full Text Available Terrestrial mollusca are sparsely studied in Chile and, for the first time, a formal record of the diversity of land snails in northern Chile is reported. Coastal and desertic areas in the Region of Atacama, in the border of the Atacama desert and the Pacific Ocean, were surveyed with the aim to describe the presence and distribution of this poorly known fauna. Of the fourteen species recorded, the geographic distribution records for nine species are extended, and some taxa are recorded for the first time since their original descriptions. All, except one, of the fourteen terrestrial molluscan species occurring in the area are endemic to Chile; they are all terrestrial species, most of them have a restricted geographic distribution, and none of them is currently protected by law. The results reveal that the region of Atacama has one of the most diverse terrestrial snail biodiversity in Chile, ranking only after the Juan Fernandez Archipelago. Distribution records of all the studied species and a taxonomic key are also provided.

  11. Annotated type catalogue of the Orthalicoidea (Mollusca, Gastropoda) in the Museum für Naturkunde, Berlin.

    Science.gov (United States)

    Breure, Abraham S H

    2013-01-01

    The type status is described of 96 taxa classified within the superfamily Orthalicoidea and present in the Mollusca collection of the Museum für Naturkunde der Humboldt-Universität zu Berlin. Lectotypes are designated for the following taxa: Orthalicus elegans Rolle, 1895; Bulimus maranhonensis Albers, 1854; Orthalicus nobilis Rolle, 1895; Orthalichus tricinctus Martens, 1893. Orthalicus sphinx tresmariae is introduced as new name for Zebra sphinx turrita Strebel, 1909, not Zebra quagga turrita Strebel, 1909. The following synonyms are established: Zebra crosseifischeri Strebel, 1909 = Orthalicus princeps fischeri Martens, 1893; Orthalicus isabellinus Martens, 1873 = Orthalicus bensoni (Reeve, 1849); Zebra zoniferus naesiotes Strebel, 1909 = Orthalicus undatus (Bruguière, 1789); Porphyrobaphe (Myiorthalicus) dennisoni pallida Strebel, 1909 = Hemibulimus dennisoni (Reeve, 1848); Zebra delphinus pumilio Strebel, 1909 = Orthalicus delphinus (Strebel, 1909); Orthalicus (Laeorthalicus) reginaeformis Strebel, 1909 = Corona perversa (Swainson, 1821); Bulimus (Eurytus) corticosus Sowerby III, 1895 = Plekocheilus (Eurytus) stuebeli Martens, 1885. The taxon Bulimus (Eudioptus) psidii Martens, 1877 is now placed within the family Sagdidae, tentatively in the genus Platysuccinea. Appendices are included with an index to all the types of Orthalicoidea extant (including those listed by Köhler 2007) and a partial list of letters present in the correspondence archives.

  12. Site Evaluation Studies of the Massachusetts Bay Disposal Site for Ocean Disposal of Dredged Material

    Science.gov (United States)

    1988-07-05

    nutritive to primary productivity. Although no phosphate EPA criteria exist (EPA, 1987), this nutrient often is the causative agent in eutrophication...ANNEL IDA Polychaeta Sabellidae Myxicola sp. 0.56 7.13 BRACHIOPODA Terebratulina sp. - 0.09 MOLLUSCA Bivalvia Pectin idae Placopecten sp. -0.01

  13. Screening of antiangiogenic potential of twenty two marine invertebrate extracts of phylum Mollusca from South East Coast of India

    Institute of Scientific and Technical Information of China (English)

    Pankaj Gupta; Muthuvel Arumugam; Raj Vardhan Azad; Rohit Saxena; Supriyo Ghose; Nihar Ranjan Biswas; Thirumurthy Velpandian

    2014-01-01

    Objective: To evaluate the antiangiogenic potential of twenty two marine invertebrate species of Phylum Mollusca from south east coast of India.Methods:Live specimens of molluscan species were collected and their methanolic extracts were evaluated for preliminary antiangiogenic activity using the in ovo chick chorio-allantoic membrane assay. The extracts were further evaluated for in vivo antiangiogenic activity using chemical cautery induced corneal neovascularization assay in rats and oxygen induced retinopathy assay in rat pups.Results:In the chick chorio-allantoic membrane assay, four methanolic extracts of marine molluscan species viz. Meretrix meretrix, Meretrix casta, Telescopium telescopium and Bursacrumena methanolic extracts exhibited noticeable antiangiogenic activity at the tested concentration of 200 µg whereby they significantly inhibited the VEGF induced proliferation of new blood vessels. Among these four extracts, the methanolic extract of Meretrix casta exhibited relatively higher degree of antiangiogenic activity with an inhibitiory percentage (64.63%) of the VEGF induced neovascularization followed by the methanolic extracts of Telescopium telescopium (62.02%), Bursa crumena (60.48%) and Meretrix meretrix (47.01%). These four methanolic extracts were further evaluated for in vivo antiangiogenic activity whereby the methanolic extract of Telescopium telescopium exhibited most noticeable inhibition (42.58%) of the corneal neovascularization in rats in comparison to the sham treated group, and also exhibited most noticeable inhibition (31.31%) of the oxygen induced retinal neovascularization in rat pups in comparison to the hyperoxia group that was observed for considerable retinal neovascularization.Conclusions:The significant antiangiogenic activity evinced by the extract of Telescopium telescopium merits further investigation for ocular neovascular diseases.

  14. 软体动物门起源和进化中的模糊问题研究%Research on Some Fuzzy Problems of the Origin and Evolution of Mollusca

    Institute of Scientific and Technical Information of China (English)

    阎锡海

    2012-01-01

    软体动物进化是生物进化重要组成部分之一,是生物进化论、动物学研究重要内容之一。根据古生物学、现代生物进化论研究成就,就软体动物起源、进化及一些类群兴盛、绝灭原因中的模糊问题进行了研究。%Mollusca evolution is an important part of biological evolution and zoology.Based on the achievements of paleontology and modern biological evolution,the paper researches some fuzzy problems of the origin and evolution and prosperity and extinction of of mollusca.

  15. A preliminary study of iron isotope fractionation in marine invertebrates (chitons, Mollusca) in near-shore environments

    Science.gov (United States)

    Emmanuel, S.; Schuessler, J. A.; Vinther, J.; Matthews, A.; von Blanckenburg, F.

    2014-10-01

    Chitons (Mollusca) are marine invertebrates that produce radulae (teeth or rasping tongues) containing high concentrations of biomineralized magnetite and other iron-bearing minerals. As Fe isotope signatures are influenced by redox processes and biological fractionation, Fe isotopes in chiton radulae might be expected to provide an effective tracer of ambient oceanic conditions and biogeochemical cycling. Here, in a pilot study to measure Fe isotopes in marine invertebrates, we examine Fe isotopes in modern marine chiton radulae collected from different locations in the Atlantic and Pacific oceans to assess the range of isotopic values, and to test whether or not the isotopic signatures reflect seawater values. Values of δ56Fe (relative to IRMM-014) in chiton teeth range from -1.90 to 0.00 ‰ (±0.05‰ (2σ) uncertainty in δ56Fe), probably reflecting a combination of geographical control and biological fractionation processes. Comparison with published local surface seawater Fe isotope data shows a consistent negative offset of chiton teeth Fe isotope compositions relative to seawater. Strikingly, two different species from the same locality in the North Pacific (Puget Sound, Washington, USA) have distinct isotopic signatures. Tonicella lineata, which feeds on red algae in the sublittoral zone, has a mean δ56Fe of -0.65 ± 0.26‰ (2σ, 3 specimens), while Mopalia muscosa, which feeds on both green and red algae in the eulittoral zone, shows lighter isotopic values with a mean δ56Fe of -1.47 ± 0.98‰ (2σ, 5 specimens). Three possible pathways are proposed to account for the different isotopic signatures: (i) physiologically controlled processes within the chitons that lead to species-dependent fractionation; (ii) diet-controlled variability due to different Fe isotope fractionation in the red and green algal food sources; and (iii) environmentally controlled fractionation that causes variation in the isotopic signatures of bioavailable Fe in the different

  16. The complete mitochondrial genome of the clam Mactra veneriformis (Bivalvia: Mactridae): has a unique non-coding region, missing atp8 and typical tRNA Ser.

    Science.gov (United States)

    Meng, Xueping; Shen, Xin; Zhao, Nana; Tian, Mei; Liang, Meng; Hao, Jue; Cheng, Hanliang; Yan, Binlun; Dong, Zhiguo; Zhu, Xiaoling

    2013-12-01

    Mactra veneriformis (Bivalvia: Mactridae) is one commonly cultured bivalve species in the western Pacific Ocean. In the current study, the complete mitrochondrial DNA (mtDNA) of the clam M. veneriformis was determined. The M. veneriformis mt genome is 16,854 bp in length and encodes 34 genes on the same strand, including 12 protein-coding genes (PCGs), 2 ribosomal RNA genes and 20 transfer RNA genes. The length of 12 PCGs is 11,358 bp, which accounts for 67.4% in whole mt genome. The proportion is similar to other clams' mt genomes and within those of bivalves mt genomes. Gene order (which is the same as that of RZ C. antiquata) of M. veneriformis mt genome is compared with that of other veneroids. Compared with the typical gene content of animal mt genomes, atp8 and two tRNA(Ser) genes are missing in the mt genome. All non-coding regions are 1978 bp in length, among them the longest one is speculated as the control region, which is located between the tRNA(His) and tRNA(Arg). The secondary largest non-coding region (NCR(664)) between the tRNA(Gln) and tRNA(Thr) in the M. veneriformis mt genome contains one section of tandem repeats (125 nt × 5.2 or 249 nt × 2.6). The tandem repeats account for 97.89% (650/664) of the NCR(664), which is a unique characteristic of the M. veneriformis mt non-coding regions compared with those of other veneroids.

  17. 基于线粒体细胞色素c氧化酶亚基I基因序列的帘蛤科贝类分子系统发育研究%Phylogenetic analysis of Veneridae (Mollusca: Bivalvia) based on the mitochondrial cytochrome c oxidase subunit I gene fragment

    Institute of Scientific and Technical Information of China (English)

    程汉良; 彭永兴; 董志国; 易乐飞; 孟学平; 申欣; 周旻纯; 陈冬勤

    2013-01-01

    对21种帘蛤科贝类线粒体细胞色素c氧化酶亚基I(cytochrome c oxidase subunit I,COI)基因核苷酸序列进行了分析,以探讨这一序列在种质鉴定、分子系统发生研究中的应用价值.测序结果表明,所有物种扩增片段长度均为707 bp(含引物),序列A+T含量(62.4%-67.8%)明显高于G+C含量.物种间共有变异位点379个,其中简约信息位点334个;此区段共编码235个氨基酸,种间共有氨基酸变异位点100个.以COI基因片段序列为标记,用中国蛤蜊(Mactra chinensis)作外群,构建了35种帘蛤科贝类(其中14种贝类COI序列从GenBank下载)的系统发生树,结合拓扑结构分析和序列比对分析,结果表明:支持将短文蛤(Meretrix petechinalis)和丽文蛤(M.lusoria)订为文蛤(M.meretrix)的同物异名的观点,建议将丽文蛤和短文蛤订为文蛤的地理亚种;支持将薄片镜蛤(Dosinia corrugata)和D.angulosa订为2个独立种的观点;认为将波纹巴非蛤(Paphia undulata)和织锦巴非蛤(P.textile)订为2个独立种是合适的.COI基因序列含有丰富的遗传信息,适合作为帘蛤科贝类种群遗传结构和系统发生研究的分子标记.

  18. GENETIC DIVERSITY OF FIVE FRESHWATER MUSSELS IN GENUS ANODONTA (MOLLUSCA: BIVALVIA ) REVEALED BY RAPD ANALYSIS%通过RAPD分析揭示五种淡水无齿蚌(软体动物门:双壳类)的遗传多样性

    Institute of Scientific and Technical Information of China (English)

    WEI Kai-Jian; XIONG Bang-Xi; ZHANG Gui-Rong

    2006-01-01

    Unionidae are an important group of benthic freshwater species. Due to the convergence phenomenon within freshwater mussels, there is still much controversy in the classification of Chinese Unionidae. In China, most studies on freshwater mussels emphasized resource investigation, biology and morphology, while little has been done in genetics, and particularly not in population genetic structure as well as genetic diversity. In order to further understand the status of genetic diversity of different species,random amplified polymorphic DNA (RAPD) markers were used to detect genetic diversity of populations in five species of the genus Anodonta : Anodonta arcaeformis , A . arcaeformis flavotincta , A .fluminea , A . woodiana woodiana and A . w . pacifica .DNA extraction method was based on phenol-chloroform and extracted genomic DNA from the adductor muscle and mantle tissues.Sixteen random primers were used for RAPD amplification and the polymorphism of amplified loci were analyzed. The results demonstrated that the percentage of amplified polymorphic loci for various populations ranged from 34.5% to 62.8%, the mean Shannon' s genetic diversity indices ranged from 0. 2021 to 0. 3552, and the mean intra-population Nei's genetic distance ranged from 0. 1386 to 0. 1713. In all populations of the five species, the genetic diversity for A. arcaeformis was the largest, and that of A. fluminea was the lowest. The inter-population genetic distance between A. w. woodiana and A. w. pacifica was 0.3186,so they can be considered as two sister species at the genetic angle.

  19. COI-based DNA Barcoding in Tapetinae Species (Mollusca, Bivalvia, Veneridae) Along the Coast of CHINA%基于COI序列的DNA条形码在中国沿海缀锦蛤亚科贝类中的应用分析

    Institute of Scientific and Technical Information of China (English)

    陈军; 李琪; 孔令锋; 郑小东; 于瑞海

    2010-01-01

    该研究探讨了将COI序列应用于中国沿海缀锦蛤亚科贝类物种鉴定的可行性,获得了该亚科5属11种贝类51个个体的43个单倍型序列.碱幕替换饱和性分析表明,颠换未出现饱和现象,而转换在序列分化达到10%至15%时即到达饱和.单倍犁Hap33可能是由杂交引起的,排除此瞥倍型,种内个体间遗传距离在0%到2.02%之间,平均为0.46%,属内不同种个体间遗传距离在17.21%~32.24%之间,平均为24.96%,存在条形码问隙:11种缀锦蛤哑科贝类在邻接树和贝叶斯树上都独立的单系群.该研究表明,基于COI的DNA条形码技术能够将研究所涉及的约98%的缀锦蛤亚科贝类鉴定剑种的水平,因此,利用DNA条形码技术可以对缀锦蛤亚科贝类进行有效地分类鉴定.

  20. Sequence Analysis on Mitochondrial 16S Rrna Gene Fragments and ITS2 Loci in Three Species of Mactradae (Mollusca: Bivalvia)%蛤蜊科3种贝类16SrRNA基因片段及ITS2核苷酸序列分析

    Institute of Scientific and Technical Information of China (English)

    孟学平; 高如承; 董志国; 阎斌伦; 程汉良; 李艳杰; 陈建安

    2006-01-01

    利用PCR技术分别扩增连云港及启东沿海蛤蜊科的西施舌(Coelomactra antiquata)、中国蛤蜊(Mactra chinensis)和四角蛤蜊(Mactra veneriformis)3种双壳贝的16S rRNA基因片段和ITS2核苷酸序列,测序后用DNA star软件分析了核苷酸差异.结果显示:三种贝类16S rRNA基因片段长度相同,均为306bp(去除引物),核苷酸存在多态性,共有45个变异位点,54个核苷酸发生了变异,全部为碱基置换.西施舌与中国蛤蜊此片段核苷酸的同源性为88.9%,与四角蛤蜊的同源性为88.6%,中国蛤蜊与四角蛤蜊的同源性为90.6%.三种蛤蜊ITS2序列分别为390 bp(西施舌)、441 bp(四角蛤蜊)和466 bp(中国蛤蜊),存在长度多态性,ITS2核苷酸差异分析结果显示,西施舌与中国蛤蜊的同源性为70.9%-71.1 %,西施舌与四角蛤蜊的为70.5%-71.0 %,中国蛤蜊与四角蛤蜊的同源性为88.1%-88.8%.ITS2序列分析结果与16S rRNA基因片段分析结果一致,2种分子分析法均显示中国蛤蜊与四角蛤蜊的亲缘关系近.

  1. MOLECULAR PHYLOGENY OF MERETRIX(MOLLUSCA, BIVALVIA)BASED ON 16S rRNA GENES AND ITS1 SEQUENCES%文蛤属(Meretrix)16S rRna基因及ITS1序列的系统学分析

    Institute of Scientific and Technical Information of China (English)

    潘宝平; 吴琪; 张素萍; 宋林生; 卜文俊

    2006-01-01

    利用线粒体16S rRNA基因片段及核糖体DNA转录间隔区ITS1序列分析的方法,以近缘属的青蛤(Cyclina sinensis)为外群,对文蛤属的文蛤(M.meretrix)、丽文蛤(M.lusoria)、帘文蛤(M.lyrata)和斧文蛤(M.lamarckii)4种贝类进行了系统学研究.经ClustalX多重比对及DNAsp软件分析后,用PAUP4.0分析软件,计算出种间序列的碱基转换/颠换频率,利用邻接法NJ构建系统发育树.结果表明,帘文蛤与该属其他三种的分歧时间较早,两类序列与其他种类间的相对遗传距离分别在0.25866-0.28218和0.15644-0.20104之间.文蛤与丽文蛤间的16S rDNA及ITS1序列间的遗传距离仅为0.04805和0.04201,拓扑结构图显示关系很近,并且二者的分布区大面积重叠,其序列间的转换/颠换频率接近种内单元型(haplotype)间的序列变化,鉴于它们的贝壳形态有一定差别,应归为同一个种内的不同地理亚种比较恰当.

  2. Fluorescent amplified fragment length polymorphism (fAFLP)analysis of population genetic diversity and species relationships of four species of cultured clams in family Veneridae (Mollusca: Bivalvia)%帘蛤科4种养殖蛤群体遗传多样性和种间关系的fAFLP分析

    Institute of Scientific and Technical Information of China (English)

    彭永兴; 程汉良; 夏德全; 吴婷婷; 孟学平; 吉红九; 董志国

    2008-01-01

    利用荧光标记扩增片段长度多态性(fAFLP)技术对文蛤(Meretrix meretrix)、青蛤(Cyclina sinensis)、菲律宾蛤仔(Ruditapes philippinarum)和硬壳蛤(Mercenaria mercenaria)4种帘蛤科贝类的群体遗传多样性和种间关系进行了研究.选择EcoR Ⅰ/Mse Ⅰ进行酶切,使用6个E+3/M+3引物组合进行扩增,共获得1096个位点,多态位点比率95.1%,片段长度50~456 bp.其中,文蛤、青蛤、菲律宾蛤仔和硬壳蛤分别得到681,715,702和694个位点,相应的多态位点比率为76.8%,81.7%,83.0%和75.1%,得到17个种特异性位点,可作为4物种特征标记.分析了群体遗传相似系数和遗传多样性指数以及种间遗传相似系数.结果表明,硬壳蛤群体遗传相似系数最高(0.670 9),遗传多样性指数最低(0.236 0);菲律宾蛤仔群体遗传相似系数最低(0.592 5),遗传多样性指数最高(0.261 8);根据遗传相似系数采用UPGMA法构建了4物种32个体的聚类图,表明文蛤与菲律宾蛤仔遗传关系最近,青蛤与其他3物种遗传关系较远.

  3. Sequence analysis of mitochondrial COI gene fragment of six Veneridae clams ( Mollusca: Bivalvia) and four populations of Meretrix meretrix%6种帘蛤科贝类及4个地理种群文蛤线粒体COI基因片段序列分析

    Institute of Scientific and Technical Information of China (English)

    程汉良; 夏德全; 吴婷婷; 孟学平; 吉红九; 董志国; 陈淑吟

    2007-01-01

    对文蛤(Meretrix meretrix L,1758)、青蛤(Cyclina sinensis G.,1791)、硬壳蛤(Mercenaria mercenaria L,1758)、江户布目蛤(Protothaca jedoensis L,1874)、薄片镜蛤(Dosinia corrugata R.,1850)和菲律宾蛤仔(Ruditapes philippinarum A.,1850)6种帘蛤科贝类和4个地理种群文蛤(大连、连云港、湛江、防城港)的细胞色素c氧化酶亚基Ⅰ(COI)基因片段的核苷酸序列进行了分析,以探讨这一序列在种质鉴定、种群遗传结构和分子系统发生研究中的应用价值.测序结果表明,所有物种扩增片段长度均为709 bp,序列A+T含量(62.2%~67.6%)明显高于GC含量.物种间共有变异位点311个,其中简约信息位点202个;文蛤4个地理种群间共有变异位点46个,其中简约信息位点2个.此区段共编码235个氨基酸,种间共有氨基酸变异位点85个;文蛤种群间只有1个氨基酸变异位点.以COI基因片段序列为标记,用大竹蛏(Solen grandis)作外群,构建了帘蛤科贝类的系统发生树,其拓扑结构显示4个地理种群文蛤首先聚为1个单元,然后与青蛤聚在一起,最后所有帘蛤科物种聚为一枝,与外群相区别,其结果与传统形态分类基本一致,说明COI基因适合作为该科贝类种群遗传结构和系统发生研究的分子标记.

  4. Early stage morphogenesis: an approach to problems of taxonomy, phylogeny and evolution in the Mytilidae (Mollusca: Bivalvia)%早期形态发生:一种解决贻贝科(软体动物门:双壳纲)分类、系统发育和进化问题的方法

    Institute of Scientific and Technical Information of China (English)

    George A. EVSEEV; Olga Ya. SEMENIKHINA; Natalya K. KOLOTUKHINA

    2005-01-01

    Sequence of appearance and transformations of morphological structures during larval and juvenile mytilids life histories have been examined. Ontogenies of about 60 taxa were typified into 4 morphogenetic patterns, or modes. Origin, developmental changes and homologies of the stage morphostructures were considered according to their location in three morphogenetic fields. The first, or central, field forms at the prodissoconch Ⅰ stage (PD-Ⅰ). It can be inherited by prodissoconch Ⅱ (PD-Ⅱ) and nepioconch (N) stages in one taxa, or PD-Ⅱ, N and dissoconch (D) stages in others. The second, or postero-dorsal, field appears at the N stage, and the third field, or antero-dorsal, at the D stage. The postero-dorsal field of the stage D inherits the N-morphostructures in one taxa, or D-stage in others. Central and postero-dorsal field morphostructures exhibit developmental sequences, or a system of characters which possess polarity, in contrast to adult characters applied in mytilid taxonomy. Based on early stage morphological characters of and well-known features studied previously but not used in taxonomy and phylogeny, a revaluation Soot-Ryen's system of supraspecific taxa and reconstruction of phylogenetic relationships among the Recent Mytilidae have been attempted. In the presented scheme, the subfamilies of Scarlato and Starobogatov (1984) form four phylogenetic lines beginning with the Modiolinae.%作者对贻贝科贝类的幼虫和幼贝期发育阶段形态结构的出现和变化顺序进行了研究,其约60个不同分类单元的个体发生可归纳为4种形态发生类型或模式.主要对3个形态发生区域的阶段形态结构的起源、发育变化和同源性做了研究.其一,即中央区域,开始形成于前双壳Ⅰ期(PD-Ⅰ),在某个分类单元它可以在前双壳Ⅱ期(PD-Ⅱ)和幼贝期(N)形成,而在其它分类单元则在前双壳Ⅱ期、幼贝期和双壳期(D)形成;第二区域,即背部后区,在幼贝期出现;第三区域,即背部前区,出现于双壳期.双壳期背部后区在某个分类单元起源于幼贝期的形态构造,在其它分类单元则可能起源于双壳期的形态构造.与在贻贝分类学上应用的成体特征相比,早期发育阶段中央和背部后区的形态结构显示出很明显的发育顺序或特征变化规律.根据以前人们熟知而尚未应用到分类和系统发育研究中的早期发育阶段形态特征,作者重新修订了Soot-Ryen的现生贻贝科种上阶元分类系统,重新提出了科内系统发育关系.修订的分类系统表明,Scarlato and Starobogatov (1984)提出的贻贝科各亚科由偏顶蛤亚科开始,沿4条系统发育路线演化发展,对应其早期发育阶段的4类形态发生类型或模式.

  5. Variación estacional de la composición proximal del mejillón Tagelus peruvianus (Bivalvia: Solecurtidae del Golfo de Nicoya, Puntarenas, Costa Rica

    Directory of Open Access Journals (Sweden)

    Cristian Fonseca Rodríguez

    2011-12-01

    Full Text Available La extracción del mejillón Tagelus peruvianus representa una actividad económica complementaria de los pescadores artesanales, es una de las especies de mayor pesca y consumo ya que son una fuente importante de proteína, minerales y vitaminas esenciales para la población humana. Por lo tanto, se estudió la variación estacional de su composición proximal, índice de condición y contenido energético. Mensualmente, entre noviembre de 2007 y octubre de 2008, se recolectaron de 35 a 40 especímenes. La composición proximal se determinó siguiendo la metodología recomendada por la AOAC. Los resultados mostraron que el índice de condición disminuyó en los meses de diciembre, enero y mayo, lo que indica que hay dos periodos de desove y una fase de reposo gonadal. El componente principal del mejillón es la proteína (61.9±4.3%, seguido de carbohidratos (15.7±2.4%, cenizas (14.0±1.9% y lípidos (8.5±1.7%. El contenido calórico promedio fue de 5.0±0.1kcal/g. La disminución en los valores de proteínas, lípidos y calorías coinciden con los periodos de desove. Se puede concluir que T. peruvianus presenta valores nutricionales óptimos para el consumo humano, por su bajo contenido de grasa y su aceptable contenido proteico.Seasonal variation in proximate composition of mussels Tagelus peruvianus (Bivalvia: Solecurtidae from the Gulf of Nicoya, Puntarenas, Costa Rica. Marine bivalves are a very important food source for human consumption, and species that has not been of traditional use as a fishery resource are gaining interest. Seasonal variation in proximate composition, condition index and energy or caloric content of the mussel Tagelus peruvianus were studied in the Gulf of Nicoya, Puntarenas, Costa Rica. From November 2007 to October 2008, a total of 35 to 40 specimens per month were collected. The proximate composition using the AOAC methods was determined. Results showed that the condition index during December, January and May

  6. Efecto de bacterias probióticas en el cultivo larvario del ostión de placer Crassostrea corteziensis (Bivalvia: Ostreidae

    Directory of Open Access Journals (Sweden)

    Angel Isidro Campa-Córdova

    2011-03-01

    Full Text Available El ostión de placer u ostra del Cortés (Crassostrea corteziensis se considera como una especie con potencial para ser cultivada en gran escala. Sin embargo, al igual que en otros bivalvos, la alta mortalidad que se presenta durante la etapa larvaria y juvenil, es el principal problema que limita el desarrollo del cultivo en el laboratorio. Un método que está ganando aceptación en la acuicultura es el uso de bacterias probióticas para controlar patógenos microbianos. Este estudio analiza el efecto de estas bacterias en la supervivencia y talla final de larvas de ostión de placer Crassostrea corteziensis. Se utilizó una cepa de bacterias ácido lácticas (cepa NS61 aisladas N. subnodosus, así como de bacilos aislados de L. vannamei (Pseudomonas aeruginosa, cepa YC58 y de C. corteziensis (Burkholderia cepacia, cepa Y021. Las cepas se evaluaron por inmersión en cultivos larvarios de C. corteziensis a dos concentraciones diferentes, hasta completar el estadio pediveliger. Los organismos se trataron con bacterias ácido lácticas (Lb, una mezcla de bacilos (Lb en proporción 1:1 y un grupo control. La concentración de 1x10(4UFC/ml registró una mayor supervivencia con Lb y Mb respecto al grupo control. La supervivencia con Mb a una concentración de 1x10(5UFC/ml fue mayor que la del grupo control y del grupo tratado con Lb. Los resultados mostraron que las larvas de C. corteziensis tratadas con probióticos no incrementaron significativamente su talla respecto a las larvas del grupo control. Mientras que las tratadas con Lb a la concentración mayor, 1x10(5UFC/ml, mostraron una disminución de la supervivencia respecto a las tratadas con 1x10(4UFC/ml. Este estudio demostró el efecto benéfico de cepas probióticas utilizadas individualmente o en mezcla en el cultivo larvario de C. corteziensis.Effect of probiotic bacteria on survival and growth of Cortez oyster larvae, Crassostrea corteziensis (Bivalvia: Ostreidae. Disease control

  7. Seasonal variation in larval density of Limnoperna fortunei (Bivalvia, Mytilidae in the Iguaçu and Paraná rivers, in the region of Foz do Iguaçu, Paraná, Southern Brazil

    Directory of Open Access Journals (Sweden)

    Débora Pestana

    2008-06-01

    Full Text Available The larval density of the invasive mussel Limnoperna fortunei (Bivalvia, Mytilidae was monitored from January 2005 to February 2006 at two points along the Paraná and the Iguaçu Rivers, near Foz do Iguaçu, PR, Brazil. The results indicated two density peaks in the Paraná River: a lower peak between March and June and a higher peak in October. In the Iguaçu River, the values were much lower, yet they also showed a peak between September and October. A reduction in the reproductive activity was observed in both the rivers between July and August. The average larval density at the collection point in the Paraná reached 948.5 larvae/m³, with a peak of 2,999.5 larvae/m³ in October. The present study represented the first quantification of the larval density of L. fortunei in the lower reaches of the Iguaçu River, downstream of the Iguaçu falls.A densidade larval do molusco invasor Limnoperna fortunei (Bivalvia, Mytilidae foi monitorada entre janeiro de 2005 e fevereiro de 2006 em dois pontos dos rios Paraná e Iguaçu, na região de Foz do Iguaçu, PR. Os resultados registraram dois picos de densidade no rio Paraná: entre março e junho e um maior em outubro. No rio Iguaçu, os valores foram muito inferiores, mas também com um pico entre setembro-outubro. Em ambos os rios foi verificada uma pausa reprodutiva entre os meses de julho-agosto. A densidade média de larvas de L. fortunei no ponto amostrado no rio Paraná chegou a 948.5 larvas/m³, com pico de 2.999,5 larvas/m³ em outubro. O presente estudo representa a primeira quantificação da densidade larval de L. fortunei no rio Iguaçu, a jusante das Cataratas do Iguaçu.

  8. Community benthic paleoecology from high-resolution climate records: Mollusca and foraminifera in post-glacial environments of the California margin

    Science.gov (United States)

    Myhre, Sarah E.; Kroeker, Kristy J.; Hill, Tessa M.; Roopnarine, Peter; Kennett, James P.

    2017-01-01

    Paleoecological reconstructions of past climate are often based on a single taxonomic group with a consistent presence. Less is known about the relationship between multi-taxon community-wide change and climate variability. Here we reconstruct paleoecological change in a Late Quaternary (16.1-3.4 ka) sediment core from the California margin (418 m below sea level) of Santa Barbara Basin (SBB), USA, using Mollusca (Animalia) and Foraminifera (Rhizaria) microfossils. Building upon previous investigations, we use multivariate ordination and cluster analyses to interpret community-scale changes in these distinctly different taxonomic groups across discrete climate episodes. The strongest differences between seafloor biological communities occurred between glacial (prior to Termination IA, 14.7 ka) and interglacial climate episodes. Holocene communities were well partitioned, indicating that sub-millennial oceanographic variability was recorded by these microfossils. We document strong evidence of chemosynthetic trophic webs and sulfidic environments (from gastropod Alia permodesta and bivalve Lucinoma aequizonata), which characterized restricted intervals previously interpreted as well oxygenated (such as the Pre-Bølling Warming). Mollusc records indicate first-order trophic energetic shifts between detrital and chemosynthetically-fixed carbon. Molluscs associated with widely different physiological preferences occur here within single, decadal intervals of sediment, and as such mollusc assemblages may reflect significant inter-decadal oceanographic variability. Foraminifera assemblages provide exceptional records of the sequential, chronological progression of the deglacial climatic and oceanographic events, whereas mollusc assemblages reflect non-chronological similarities in reoccurring communities. Foraminifera taxa that drive community similarity here are also independently recognized as marker species for seafloor hypoxia regimes, which provides support for the

  9. Experimental Gravel Bar Habitat Creation in the Tombigbee River, Mississippi

    Science.gov (United States)

    2006-02-01

    3 Tennessee-Tombigbee Waterway shortened the distance to the Gulf of Mexico by almost 1,290 km (800 miles) (Brose 1991). PROJECT DESIGN AND...designed to pro- vide a more direct shipping route between the eastern gulf coast and the mid-continental United States. This was done by connecting the...policy for protecting endangered species,” Science 268, 1231-1232. Fuller, S. L. H. (1974). “Clams and mussels ( Mollusca : Bivalvia).” Pollution ecology

  10. Benthic Flux of Dissolved Nickel into the Water Column of South San Francisco Bay

    Science.gov (United States)

    2001-01-01

    Phosphorous (N:P) Benthic Flux Ratio Fig. 9 – Incubation Core Design Fig. 10 – Macroinvertebrate Taxonomy Fig. 11 – Benthic Chlorophyll Analyses Fig...l a r F l u x R a t i o Redfield Ratio Incubation Core Design Fig. 9 Benthic Macroinvertebrate Taxonomy Fig. 10 Benthic Chlorophyll...98 25-May-99 08-Apr-98 15-Sep-98 25-May-99 Phylum Mollusca Class Bivalvia Potamocorbula amurensis 520 303 195 Musculista senhousia 43 130 Mya

  11. TEMPORAL AND SPATIAL DISTRIBUTIONAL PATTERNS OF MOLLUSCA IN A TYPICAL AQUACULTURAL LAKE -- DATONG LAKE%典型养殖湖泊大通湖软体动物的时空分布格局

    Institute of Scientific and Technical Information of China (English)

    李德亮; 张婷; 余建波; 毛小伟; 王红权; 陈开健; 刘安民; 李祖军; 肖调义

    2011-01-01

    研究于 2008 年 12 月至 2009 年 10 月按季度对大通湖水质及软体动物资源监测,并通过纵向比较,探讨了集约化养殖对大通湖水域环境及软体动物群落的影响,以期为其渔业可持续发展提供理论依据.结果显示,大通湖水质全年呈碱性 (8.62 ± 0.07),具有较高的还原性 [(-88.40 ± 9.10) mv],属富营养水体.软体动物共计 5 科 15 种,梨形环棱螺(Bellamya purificata)、河蚬(Corbicula fluminea)和圆顶珠蚌(Uniodoug lasiae)是主要优势种.软体动物平均密度和生物量具有明显的时空差异,时间上呈现由春夏季到秋冬季逐渐升高的趋势,空间上整体呈现由东北向西南逐渐递减的趋势.典范对应分析表明氧化还原电位、pH、溶氧、水深、电导率和水温与大通湖软体动物时空变化的关系最显著.与 1960 年相比,大通湖水体碱性显著增强 (7.0-7.5 vs 8.4-8.8),电导率增加了 9 倍 (0.25-0.27 vs 2.17-2.56 mS/cm),环境类型由氧化型转变为还原型.湖区喜好水草 (白旋螺、光亮隔扁螺、萝卜螺) 与流水生境 (德氏狭口螺、湖沼股蛤、橄榄蛏蚌) 的物种消失,软体动物优势种群呈现由双壳类向腹足类演替的特征.生境破坏和过度捕捞是大通湖软体动物资源面临的最大威胁,也是湖区渔业可持续发展所面临的核心问题.%The environmental characteristics and Mollusca community in Datong Lake were investigated seasonally from December 2008 to October 2009. Potential effects of intensive aquaculture on water quality and Mollusca in Datong Lake were studied by comparing the current sampling with the historical data in 1960, to provide theoretical support for sustainable fishery of the freshwater lakes. The results showed that Datong Lake was eutrophic and the water was alkaline (8.62 ± 0.07), with higher reducibility (-88.40 ± 9.10 mv). Fifteen Mollusca species were recorded, belonging to 5 families. Bellamya purificata, Corbicula

  12. The Diversity of Molluscas Was Applied to Monitor the Heavy Metals in the Huayuan River%软体动物多样性在花垣河水体重金属监测中的应用

    Institute of Scientific and Technical Information of China (English)

    刘俊; 郑济芳; 胡南; 胡劲松; 朱允华; 刘运莲; 殷杰

    2009-01-01

    对湘西花垣河软体动物多样性与重金属污染状况进行了调查.在花垣河8个监测断面中,除S1、S3、S8的软体动物丰富度指数(DMA)与Shannon-Wiener多样性指数(H′)分别介于0.264 3-2.493 7和0.676 5-2.412 3外,S2、S4、S5、S7、S8五个断面的软体动物丰富度和多样性指数均为零.Mn、Cd、Pb、Cu、Zn在花垣河8个监测断面的河水中都能检测到,其中Mn、Cd含量严重超出GB的Ⅴ类水标准.软体动物多样性监测与理化监测的结果均表明,花垣河水体已经受到严重重金属污染.%The diversities of molluscas and the pollution of heavy metals in the Xiangxi Huayuan River were investigated.The species richness indexes (DMA) and Shannon-Wiener diversity indexes (H′) of mollusca at S1,S3,S8 were 0.264 3-2.493 7 and 0.676 5-2.412 3,respectively.The DMA and H′ at the other 5 sections were zero.Mn、Cd、Pb、Cu、Zn were identified in the water,the concentrantions of Mn and Cd were severe exceed the standard of limits of Ⅴ class water of GB.The results of the diversities of molluscas and the physico-chemical monitoring suggested that the water of the Huayuan River had been polluted by heavy metals severity.

  13. 山东潍坊地区医学贝类种类及分布调查研究%The Species and Ecological Distribution of Medical Mollusca in Weifang, Shandong Province

    Institute of Scientific and Technical Information of China (English)

    郭云海; 李娜; 胡玲; 张仪; 周晓农

    2013-01-01

    目的 调查山东潍坊地区医学贝类种类及分布. 方法 选择山东潍坊地区的潍坊市区、寿光、安丘和昌邑等地,现场采集医学贝类标本,进行形态学鉴定和分类定种. 结果 共获得标本1 791个,经形态学鉴定,隶属于2纲9科14种,包括重要医学贝类的纹沼螺(Parafsaruluss triatulus)383个、长角涵螺(Alocinma longicornis)34个、小土蜗(Galba pervia) 63个、椭圆萝卜螺(Radix swinhoei)137个、耳萝卜螺(R.auricularia)95个、尖膀胱螺(Physa acuta) 677个和尖口圆扁螺(Hippeutis cantori)22个.其中纹沼螺和尖膀胱螺为优势物种. 结论 山东潍坊地区可传播寄生虫的医学贝类种类较多.%Objective To investigate the species and distribution of mollusca with medical importance in Weifang,Shandong Province.Methods Species identification and quantitative statistics analysis was studied based on field-collected snails from the districts of Weifang,Shouguang,Anqiu and Changyi,Shandong Province.Results A total of 1 791 medical mollusca specimens were collected,belonging to two Classes,9 families and 14 species.Some important species were discovered including Parafossarulus striatuluis(383),A locinma longicornis(34),Galba pervia (63),Radix swinhoei (137),R.auricularia (95),Physa acuta(677) and Hippeutis cantori(22).The dominant species were P.acuta and P.striatulus.Conclusion There remains a higher diversity of medical mollusca in Weifang,Shandong Province.

  14. Ciclo reproductivo del ostión de manglar Crassostrea rhizophorae (Bivalvia: Ostreidae en la Bahía de Camamu, Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Tiago Lenz

    2011-03-01

    Full Text Available El ostión de manglar es un importante recurso pesquero que se distribuye por toda la costa brasileña y una de las especies nativas con mayor potencial para maricultura. Este estudio tuvo como objetivo conocer las características reproductivas del ostión de manglar Crassostrea rhizophorae en el estero del Río Maraú, Bahía de Camamu, Bahia, Brasil. Las muestras fueran recolectadas mensualmente, entre agosto de 2006 y septiembre de 2007, en dos sitios. Las metodologías utilizadas fueron el análisis histológico de las gónadas y el cálculo de rendimiento de carne. La temperatura del agua durante el período de estudio varió de 23.5°C a 30°C y la salinidad osciló entre 15 y 35ups. La altura de los ostiones examinados varió de 27 a 102mm (n=437. Hubo predominancia de hembras en las poblaciones de ambos sitios. Los análisis de estadios gonádicos demostraron que el proceso de reproducción de C. rhizophorae en el estero del Río Maraú es continuo durante el año, sin período de reposo sexual. El rendimiento de carne (R fue de 8.0% a 17.7% (n=669. Los resultados de este estudio proveen informaciones para la captación de semilla e implantación de la ostricultura en la Bahía de Camamu.Reproductive cycle of the mangrove oyster Crassostrea rhizophorae (Bivalvia: Ostreidae in Camamu Bay, Bahia, Brasil. The mangrove oyster Crassostrea rhizophorae is important fishery resource along the entire Brasilian coast with excellent potential for marine culture. The purpose of this paper was to examine the reproductive characteristics of the oyster of the Maraú river estuary in Camamu Bay, Bahia, Brasil. The samples were collected monthly, from September 2006 to August 2007, at two points (I and II in Camamu Bay. At each site 20 oysters were collected for histological analysis, fixed in Davidson’s solution, embedded in paraffin, dehydrated in an ethanol series, sectioned (7μm thick and stained with Harris hematoxylin and Eosin (HE

  15. Introducción al estudio de los gasterópodos (Mollusca de la laguna de Montcortès (Pallars Sobirà, Cataluña, NE de la península ibérica

    Directory of Open Access Journals (Sweden)

    V. Bros

    2009-01-01

    Full Text Available Introduction to the study of gastropods (Mollusca on the Montcortés lake (Pallars Sobirà, Catlonia, NE of the Iberian peninsulaThe check-list of 50 species of terrestrial gastro­pod and freshwater molluscs in the Montcortès lake (Catalonia, Spain and its environs, pertaining to 24 different families, is shown. Thirty-three species are cited for the first time in the area of study. The unpublished data on their distribution and ecological requirements are contributed. The preliminary results indicate us that the communities of molluscs that accompany to the helofitic vegetation and the higrofits well are formed with elements of high faunistic and ecological interest. Simultaneously, some recommendations for the protection of the malacological fauna of the lake are commented.

  16. Reproducción, dieta y pesquería del pulpo Octopus (Octopus hubbsorum (Mollusca: Cephalopoda en la costa de Oaxaca, México

    Directory of Open Access Journals (Sweden)

    Maria del Carmen Alejo-Plata

    2009-06-01

    Full Text Available Se analizan algunos aspectos de la biología y pesquería de Octopus hubbsorum capturado por pesca artesanal en Puerto Ángel, Oaxaca, México. Las muestras se obtuvieron de enero 2002 a noviembre 2003 con una periodicidad quincenal. A cada uno de los organismos se les registró la longitud dorsal del manto (LDM, peso total, sexo y estado de madurez gonádica. Asímismo se obtuvo el Índice Gonadosomático (IGS. Para el análisis del contenido estomacal se utilizaron los índices de frecuencia de presencia y vaciado. Se analizaron 352 organismos, con un intervalo de tallas de 4 a 19 cm LDM; la proporción de sexos fue diferente de 1 (.2= 24.2, pReproduction, diet and fishery of Octopus (Octopus hubbsorum (Mollusca: Cephalopoda in the coast of Oaxaca, Mexico. The octopus Octopus hubbsorum (Berry 1953 ranges widely and is important for the artisanal fishery in Puerto Angel, Oaxaca, Mexico. Samples were taken approximately at every two weeks from January 2002 to November 2003. All organisms were measured for dorsal mantle length (DLM and total weight; sex and maturity gonadic stage were registered. For the stomach content analysis, frequency of occurrence and emptying indexes were used. The 352 organisms caught ranged from 4 to 18 cm in DLM; the sex ratio was different from 1 (X² = 24.2, p<0.05 throughout the year. The maximum values of the GSI appeared in May (4.1917 for females; 1.2675 in males. LDM for first sexual maturity (LDM50% was 16 cm (females and 14 cm (males. Octopus hubbsorum moves from deep waters to the coast, probably in search of better conditions, and lays masses of eggs on rocky substrata. They are fished from March to October, with higher intensity in April and May. Fishing effort was related to the oceanographic characteristics and the atmospheric conditions of the area. From April to September the CPUE monthly mean was 20-10 kg/divers/day. Using the CPUE and environmental condition relationship, the estimated adequate

  17. Tolerance to air exposure of the New Zealand mudsnail Potamopyrgus antipodarum (Hydrobiidae, Mollusca as a prerequisite to survival in overland translocations

    Directory of Open Access Journals (Sweden)

    Alvaro Alonso

    2012-08-01

    Full Text Available Spreading throughout a new ecosystem is the last step of an exotic species to become invasive. In the case of invasive aquatic molluscs, tolerance to air exposure is one of the main mechanisms allowing overland translocation and spreading. The mudsnail Potamopyrgus antipodarum (Hydrobiidae, Mollusca is native to New Zealand but it has spread worldwide, invading ecosystems in Europe, Australia, America and Asia. The aim of our study is to assess mudsnail tolerance to air exposure, which may contribute to the successful overland translocation of this species. We conducted a laboratory experiment with four levels of air exposure (9, 18, 24 and 36 hours in a controlled climatic chamber. Snails were placed for 60 seconds in a laboratory paper filter to remove surface snail water. Then they were placed back in empty vessels during the four periods of air exposure, except the control group, which was immediately returned to water. At the end of each period of air exposure all vessels were filled with water and the cumulative mortality was monitored after 24, 96, 168 and 264 hours of rehydration. The calculated Lethal Times (i.e. the time of air exposure (in hours necessary to cause the death of 50% (LT50 or 99% (LT99 of the population and their 95% confidence limits at 24, 96, 168 and 264 hours were 28.1 (25.2–31.9, 26.9 (24.2–30.1, 25.9 (23.4–28.9 and 25.9 (23.4–28.9 hours, respectively for LT50, and 49.6 (42.7–63.3, 45.6 (39.9–56.5, 43.2 (38.0–53.0 and 43.2 (38.0–53.0 hours, respectively for LT99. Therefore an air exposure time over 43 hours caused the death of all studied individuals during all monitoring periods. Extending the monitoring period beyond 24 hours did not significantly change lethal times. Therefore, we recommend exposing fishing tools or boats at open air during at least 53 hours as a low cost measure to control mudsnail spread in early stages of invasion.

  18. Biodiversidad de gasterópodos terrestres (Mollusca en el Parque Biológico Sierra de San Javier, Tucumán, Argentina

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    María José Miranda

    2010-09-01

    Full Text Available Se realizó un inventario y se analizaron parámetros de diversidad de la malacofauna terrestre del Parque Biológico Sierra de San Javier. Se llevaron a cabo muestreos cualitativos y cuantitativos en parcelas de 10x10m tomadas en transectas altitudinales, para un total de 22 169 especímenes recolectados. Las identificaciones taxonómicas se llevaron a cabo a nivel de especie. Se construyó una matriz de especies por parcela para analizar patrones de diversidad y se utilizaron estimadores no paramétricos (ICE, ACE, Chao 1 y Chao 2 para calcular la diversidad del Parque, el grado de completitud del muestreo y la agregación espacial de los datos. Se calcularon los índices de Shannon, Simpson, Whittaker y Jaccard. La riqueza del Parque fue estimada en 32 especies distribuidas en 21 géneros y 13 familias. Solo una especie pertenece a Caenogastropoda, el resto son Pulmonados Stylommatophora y Systellommatophora. La familia más representada fue Charopidae mientras que la especie con mayor abundancia relativa fue Adelopoma tucma. La riqueza y diversidad fue levemente mayor en chaco seco que en bosque húmedo de Yungas. Los valores de diversidad obtenidos fueron elevados en comparación con estudios previos realizados en el noroeste Argentino.Biodiversity of land gastropods (Mollusca in Sierra de San Javier Park, Tucumán, Argentina. Studies related to land mollusk diversity in tropical and subtropical forests are scarce. To assess this, a study on land snail diversity of subtropical cloudforest (Yungas and dry forest (Chaco areas of Sierra de San Javier Park, Tucumán, Argentina, was carried out. Taxonomic identifications were performed to species level and built a species per stations data matrix to analyze diversity patterns on qualitative and quantitative samples processed from 10x10m quadrates in altitudinal transects. Non parametric analysis (ICE, ACE, Chao 1 and Chao 2 were used to estimate the true diversity of the area, as well as the

  19. Комплексна дія екологічних факторів на ритм серцевих скорочень у перлівницевих (Mollusca: Bivalvia: Unionidae)

    OpenAIRE

    Стадниченко, А. П.; Гирин, В. К.; Іваненко, Л. Д.; Stadnychenko, A.; Gуrуn, V.; Ivanenko, L.

    2009-01-01

    The complex effect of dry and solutions of detergent (0.02, 0.2, 2 mg/dm3) on the normal beating of Unio rostratus and during the process of invasion by trematoda Bucephalus polymorphus have been investigated. It was noted that after 6 days of dry the heart rhythm increases, but in the case of complex effect of dry and solutions of detergent it decreases beneath the normal. Досліджено вплив умов обсихання, синтентичних поверхнево-активних речовин – СПАР (0,02, 0,2, 2 мг/дм3) на роботу серц...

  20. Intragenomic sequence variation at the ITS1 - ITS2 region and at the 18S and 28S nuclear ribosomal DNA genes of the New Zealand mud snail, Potamopyrgus antipodarum (Hydrobiidae: mollusca)

    Science.gov (United States)

    Hoy, Marshal S.; Rodriguez, Rusty J.

    2013-01-01

    Molecular genetic analysis was conducted on two populations of the invasive non-native New Zealand mud snail (Potamopyrgus antipodarum), one from a freshwater ecosystem in Devil's Lake (Oregon, USA) and the other from an ecosystem of higher salinity in the Columbia River estuary (Hammond Harbor, Oregon, USA). To elucidate potential genetic differences between the two populations, three segments of nuclear ribosomal DNA (rDNA), the ITS1-ITS2 regions and the 18S and 28S rDNA genes were cloned and sequenced. Variant sequences within each individual were found in all three rDNA segments. Folding models were utilized for secondary structure analysis and results indicated that there were many sequences which contained structure-altering polymorphisms, which suggests they could be nonfunctional pseudogenes. In addition, analysis of molecular variance (AMOVA) was used for hierarchical analysis of genetic variance to estimate variation within and among populations and within individuals. AMOVA revealed significant variation in the ITS region between the populations and among clones within individuals, while in the 5.8S rDNA significant variation was revealed among individuals within the two populations. High levels of intragenomic variation were found in the ITS regions, which are known to be highly variable in many organisms. More interestingly, intragenomic variation was also found in the 18S and 28S rDNA, which has rarely been observed in animals and is so far unreported in Mollusca. We postulate that in these P. antipodarum populations the effects of concerted evolution are diminished due to the fact that not all of the rDNA genes in their polyploid genome should be essential for sustaining cellular function. This could lead to a lessening of selection pressures, allowing mutations to accumulate in some copies, changing them into variant sequences.                   

  1. 西藏札达地区早侏罗世双壳类Lithiotis生物岩礁的发现及其地质意义%Discovery of the early Juassic Lithiotis(Bivalvia) bioherm in Zhada area in Tibet and its geological implications

    Institute of Scientific and Technical Information of China (English)

    李金和; 孙苑迪; 夏祥

    2013-01-01

    西藏札达地区首次发现了早侏罗世Lithiotis生物岩礁,赋存于聂聂雄拉组的下部,属进积礁类型。 Lithiotis和相邻层位化石的发现,证明聂聂雄拉组的时代下限可以延伸到早侏罗世土阿辛期,此时札达地区的古地理条件处于能够适应Lithiotis大量繁衍的低纬度碳酸盐岩台地环境。%The discovery of the early Jurassic Lithiotis(Bivalvia) bioherm, for the first time in Zhada area in Tibet, is saved in the Nieniexiongla Formation's lower part and belong to the type of prograded reef. The discovery of the Lithiotis bioherm and the close horizon fossils proof the age of Nieniexiongla Formation's lower part extend to the Toarcian of the Early Jurassic time. The term of palaeogeograph of the this time Zhada area be placed in and can adapt to the low degree of latitude carbonate platform environment that Lithiotis multiply greatly.

  2. First record of Corbicula fluminalis (Müller, 1774 in Lake Garda (Italy, living in sympatry with Corbicula fluminea (Müller, 1774

    Directory of Open Access Journals (Sweden)

    Cristina CAPPELLETTI

    2009-02-01

    Full Text Available The first record of Corbicula fluminalis (Müller, 1774 (Mollusca: Bivalvia: Veneroidea: Corbiculidae in Lake Garda (Italy is presented. This clam was observed in July 2008 along the lake shore, with a high number of shells; sampling of lake sediment revealed the presence of live specimens. C. fluminea (Müller, 1774 has already been recorded in Lake Garda since 2002. The need for further studies on the presence and the spread of the two clams and the biodiversity of the invertebrate community of the lake is underlined, in relation to recent records of other invasive species, such as Dikerogammarus villosus (Sowinsky, 1894.

  3. Phylogenetic position of the genus Perkinsus (Protista, Apicomplexa) based on small subunit ribosomal RNA.

    Science.gov (United States)

    Goggin, C L; Barker, S C

    1993-07-01

    Parasites of the genus Perkinsus destroy marine molluscs worldwide. Their phylogenetic position within the kingdom Protista is controversial. Nucleotide sequence data (1792 bp) from the small subunit rRNA gene of Perkinsus sp. from Anadara trapezia (Mollusca: Bivalvia) from Moreton Bay, Queensland, was used to examine the phylogenetic affinities of this enigmatic genus. These data were aligned with nucleotide sequences from 6 apicomplexans, 3 ciliates, 3 flagellates, a dinoflagellate, 3 fungi, maize and human. Phylogenetic trees were constructed after analysis with maximum parsimony and distance matrix methods. Our analyses indicate that Perkinsus is phylogenetically closer to dinoflagellates and to coccidean and piroplasm apicomplexans than to fungi or flagellates.

  4. [Toxicity of nitrate-N to freshwater aquatic life and its water quality criteria].

    Science.gov (United States)

    Zhang, Ling-Song; Wang, Ye-Yao; Meng, Fan-Sheng; Zhou, Yue-Xi; Yu, Hai-Bin

    2013-08-01

    The toxicity sensitivity of different freshwater aquatic organisms was analyzed using the collected toxicity data in this paper. Three methods were used to estimate the criteria of nitrate to protect the freshwater aquatic life. The results showed that the species sensitivity to nitrate followed the order of Arthropoda > Mollusca > Chordata, and Crustacea > Insecta > Gastropoda > Bivalvia > Amphibia > Actinopterygii. Moreover, the output of assessment factor method, species sensitivity distribution method and USEPA's method was significantly different. Finally, criterias of 87.97 mg x L(-1) and 5.17 mg x L(-1) to protect aquatic life from acute and chronic toxicity were proposed using USEPA's method.

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

    Science.gov (United States)

    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.

  6. COMMUNITY STRUCTURE OF BENTHIC MOLLUSCA AND ITS RELATIONSHIP WITH ENVIRONMENTAL FACTORS IN THE MAINSTREAM OF HUAIHE RIVER%淮河干流软体动物群落结构及其与环境因子的关系

    Institute of Scientific and Technical Information of China (English)

    丁建华; 周立志; 邓道贵; 金显文

    2013-01-01

    2011年3月、6月、9月和12月对淮河干流11个采集点的底栖软体类动物群落结构进行了调查研究,共记录了软体类动物9科26种,其中位于最上游的桐柏金庄种类最少,仅有3种分布,而位于中下游的新城口种类达到15种.总体上看,自上游至下游,软体动物种类的数量呈现一定的增多趋势.Pearson相关性检验结果表明软体动物种类数量和生物密度与河道深度间分别存在显著的正相关(r = 0.617,P = 0.043,n = 11)和负相关关系(r = -0.654,P = 0.029,n = 11).方差分析(One-way ANOVA)结果表明,Shannon-Wiener多样性指数[F(3,40) = 0.225,P = 0.879]、Margalef丰富度指数[F(3,40) = 0.902,P = 0.449]、Pielou均匀性指数[F(3,40) = 0.841,P = 0.479]这3种指数以及生物量[F(3,40) = 1.931,P = 0.14]不存在显著的季节性变化,但生物密度[F(3,40) = 5.45,P = 0.003]却存在极显著的季节性变化.其中,生物密度在6月份出现峰值[(90.13 ± 36.31) ind./m2],最低值出现在12月份[(14.42 ± 2.78) ind./m2];生物量的变化不与生物密度变化同步,其峰值出现在9月份[(155.08 ± 50.43) g/m2],最低值则出现在3月份[(39.15 ± 14.08) g/m2].相似性分析(One-way ANOSIM)结果表明,软体类动物群落在生物密度和生物量方面的优势物种组成上均无显著的季节性差异,其P值分别为0.082和0.514.生物密度在不同月份间的不相似百分比变化幅度从53.87%至59.12%,而生物量的不相似百分比变化幅度则从58.76%至68.58%.冗余分析(Redundancy Analysis RDA)结果表明,河宽、水深和砂质型底质为影响淮河干流底栖软体类动物分布的主要环境因子.%The benthic mollusca community structure at eleven sampling sites in Huaihe River was investigated in March, June, September and December 2011. A total of 26 species from 9 families were recorded. Thereinto, only 3 species occurred in the first upriver site: Tongbaijinzhuang, and 15 species occurred in the downriver

  7. Cloning and Functional Expression of a Multi-Functional Cellulase Gene egx from Mollusca, Ampullaria crossean in vitro%福寿螺多功能纤维素酶基因egx的克隆及其体外功能性表达

    Institute of Scientific and Technical Information of China (English)

    黄妙容; 刘德武; 吴珍芳

    2011-01-01

    [Objective] The objective of the study is to clone the multi-functional cellulase gene from Mollusca, Ampullaria crossean, and analyze its expression in vitro. [Method] The cDNA fragment was amplified by RT-PCR from the stomach of Mollusca, Ampullaria crossean, and then cloned into pMD18-T vector. Following sequencing, the gene was subcloned into the expression vector pET-32a (+) and pcDNA3.1 (+) using EcoR I and Not I restriction sites, and the enzymatic activity was determined by DNS. [Result] Sequence analysis showed that the 1 326 bp amplicon consists of 1 185 bp coding sequence and part of flanking sequence. The DNA sequence and the putative amino acid sequence shared 99% and 100% identity with the reported sequence, respectively. The purified product from E.coli BL-21 (DE3) showed hydrolytic activities to various substrates including carboxylmethyl cellulose sodium salt (CMC-Na), 2-hydroxyethyl-cellulose, hydroxyethyl-cellulose, sigmacell and xylan with specific activities of 24.78, 15.67, 18.42, 600.91 and 175.43 U·mg-1, respectiviely, while the recombination protein expressed in PK15 showed hydrolytic activities of 0.84, 0.78, 1.01, 14.62 and 4.23 U·mL-1, respectively. [Conclusion] The multi-functional cellulase from Mollusca, Ampullaria crossean, was cloned, functional expressed in pro- and eukaryotic cells, and this could provide a foundation for further research and application of the multi-functional cellulase gene from Mollusca, Ampullaria crossean.%[目的]克隆福寿螺多功能纤维素酶基因egx,并在大肠杆菌和哺乳动物细胞中进行表达分析.[方法]通过RT-PCR的方法,从福寿螺胃组织总RNA中克隆福寿螺多功能纤维素酶基因egx序列,连接克隆载体pMD18-T,再通过EcoR Ⅰ和NotⅠ两个酶切位点分别与表达载体pET-32a(+)及pcDNA3.1(+)连接,构建原核、真核表达载体,并在E.coli BL-21 (DE3)和猪肾细胞PK15中进行表达,最后采用DNS法测定表达产物酶

  8. 湛江红树林保护区软体动物群落结构与生态位分析%The Structure of the Mollusca Community and Niche Analysis in Zhangjiang Mangrove Nature Reserves

    Institute of Scientific and Technical Information of China (English)

    唐以杰; 陈康; 刘金苓

    2015-01-01

    对广东湛江红树林保护区高桥核心区软体动物进行采样调查,共采集软体动物20种,隶属1门2纲13科.其中桐花树+红海榄(Acgiceras corniculatum + Rhizophora stylosa )群落10种,桐花树+秋茄(Acgiceras corniculatum + Kandelia candel )群落6种,桐花树+白骨壤(Acgiceras corniculatum + Avicennia marina )群落13种,白骨壤+桐花树群落(Avicennia marina + Acgiceras corniculatum )16种.对软体动物密度数据进行季节和红树植物群落类型进行无重复双因素方差分析,结果显示软体动物栖息密度主要受红树植物群落类型而不是季节的影响.对定量取样中获得的20个物种以 Shannon-Wiener 指数为基础进行了生态位宽度测定,以 Pianka重叠指数为基础进行了生态位重叠值分析,结果表明琵琶拟沼螺(Assiminea lutea )、黑口滨螺(Littoraria melanostoma )和粗糙滨螺(Littorina scaber )的生态位较宽,均为2.0以上,它们之间的生态重叠值也较高,均为0.70以上.以密度数据4次开方为基础,利用欧氏距离进行群落物种的系统聚类分析,结果表明物种的聚类可以反映群落中物种生态位重叠值,但是生态位宽度的研究,要针对不同物种来分析.非度量多维标度排序分析也支持以上结果.研究表明,物种生态宽度、物种之间的生态位重叠值与物种的分布与数量密切相关,反映了软体动物群落中各物种对生境资源利用能力的强弱.%This study was conducted to explore the structure of the mollusca community and niche in Zhangjiang Mangrove Nature Reserves.The mollusks community in the four kinds of mangrove communities in the core region of Gaoqiao town were studies.A total of 20 species in the investigation, belonging to 13 families,2 classes and 1 phyla were collected.The numbers of species found in the Acgiceras corniculatum + Rhizophora stylosa ,Acgiceras corniculatum + Kandelia

  9. [Microbiologic depuration of Anadara tuberculosa (Mollusca: Arcidae)].

    Science.gov (United States)

    Wong, E; Antillón, F; Glenn, E; González, M I

    1997-12-01

    In Costa Rica the mollusk Anadara tuberculosa represents a risk for human health due to the contamination of the growing waters and the fact that its is consumed raw. The families depending on the income obtained through commercialization of these animals have a low education and economic status. Therefore, it is of great importance to develop and evaluate simple methods of depuration that could be easily used by these families to make these mollusks safe for consumption. Bottles containing 11 of saline solution (25g/l) were prepared in duplicates to test the bactericidal effect of acetic acid. The solution in each bottle was adjusted to ph 4.5, 5.0 or 5.5 or held at ph of 7.0 or 8.0 for the controls. The solution in each bottle was then inoculated with approximately 1 X 104 cfu/ml of coliforms. Counts of coliforms were determined for each bottle 0, 1, 2, 4 and 8 hours after inoculation. For the depuration studies, specimens with diameters ranging from 4.0 to 4.5 cm were collected from a harvester at the estuary of Puntarenas, Gulf of Nicoya. Fifty specimens each were depurated in separate tanks containing 25 1 of oxygenated saline solution adjusted with acetic acid to an initial ph of 4.5 (treatment) or non adjusted ph of 8.0 (control). Counts of Enterobacteriaceae were determined, in duplicates, every 12 hr for 48 hr. An additional fifty animals were depurated using the defined method and tested to determine if they met international standards of microbiological quality for aerobic plate count, Enterobacteriaceae count, Escherichia coli count and presence of Salmonella. A sensory evaluation using a triangle test was performed to compare a typical dish prepared with depurated or non-depurated animals. A significant coliform reduction was determined in a saline solution (25 g/l) at a pH range of 4.5 to 5.5. This reduction, during 8 hr, was higher in the acid treatments compared to the controls. During depuration, the elimination of Enterobacteriaceae bacteria was faster when acetic was used (initial ph = 4.5) than when it was not. This elimination was more important the first 24 hr, time defined as adequate for the application of the method. The method has the advantage of transforming the bivalve in a product that is safe for human consumption, since it guarantees that the international standards of microbiological quality, for raw and depurated mollusks, are reached. On the other hand, the sensory qualities of a typical dish prepared with depurated animals are not affected by the method, which can be easily implemented and applied by the people that work in the extraction of this mollusk.

  10. Four new African turriform gastropods (Mollusca: Conoidea).

    Science.gov (United States)

    Morassi, Mauro; Bonfitto, Antonio

    2013-01-01

    Four new species, belonging to four distinct conoidean families, are described from east Africa and Mozambique Channel. Iredalea adenensis sp. nov. (Drilliidae Olsson, 1964), from Gulf of Aden, and Buchema shearmani sp. nov. (Horaiclavidae Bouchet et al., 2011), from off Mogadishu (Somalia), both trawled by local fishermen, represent the first record of their respective genera in eastern Africa. Crassispira somalica sp. nov. (Pseudomelatomidae Morrison, 1965), also collected offshore from Modagishu (Somalia), represents the first eastern Africa species bearing "typical" Crassispira features. Tropidoturris vizcondei sp. nov. (Borsoniidae Bellardi, 1875), from the Mozambique Channel, increases the knowledge of a genus considered endemic to southeastern Africa.

  11. Lorentz Spengler's descriptions of chitons (Mollusca: Polyplacophora)

    NARCIS (Netherlands)

    Kaas, P.; Knudsen, J.

    1992-01-01

    The present paper deals with an important Danish paper on the Polyplacophora, published in 1797 by Lorentz Spengler: Udförlig Beskrivelse over det mangeskallede Konkylie-Slaegt, af Linnaeus kaldet Chiton; med endeel nye Arter og Varieteter. -Skrivter af Naturhistorie-Selskabet, 4e Bind, Ie Hefte, VI

  12. Miocene freshwater Mollusca from western Brazilian Amazonia

    NARCIS (Netherlands)

    Wesselingh, F.P.; Ranzi, A.; Räsänen, M.E.

    2006-01-01

    Thirteen species of fossil molluscs are reported from the Solimões Formation of western Brazilian Amazonia. Based on mammalian chronology of the Solimões Formation and radiometric ages reported from coeval deposits in adjacent Peru, the age of the fauna is established as Late Miocene. The fauna incl

  13. Distribution of molluscan remains in the sediment of the Chukchi Sea and its vicinity, the Arctic

    Institute of Scientific and Technical Information of China (English)

    Gao Aiguo; Xu Fengshan; Sun Haiqing; Li Lon

    2003-01-01

    The result of an analysis of mollusca remains collected from the Chukchi Sea, Beaufort Sea and Bering Sea in the First Chinese National Arctic Research Expedition, from July to September,1999 is presented. Seventeen species of mollusca have been identified, which belong to two classes: Bivalvia and Gastropoda. The compositions of the mollusca are very simple. According to the distribution pattern two groups may be distinguished among molluscan species. The Pan-Arctic and circumboreal group comprises Nuculana pernula, N. radiata, Nucula bellotii, Astarte montagui, Seripes groenlandicus, Macoma calcarea, M. moesta alaskana, Liocyma fluctuosa, Mya pseudoarenaria and Turritella polaris. Three species, Cyclocardia crebricos tata, Trichotrois coronata and Argobuccinum oregonense are components of the Pan-Arctic and Pacific boreal group. With regard to feeding habits, detritus feeders dominate. There are 7 species of detritus feeders, i.e. , Nuculana pernula, N. radiata,Nucula bellotii , Macoma calcarea , M. moesta alaskana , Macoma sp. and Trichotropis coronata . Detritus feeders are dominant with regard to the numbers of species as well as to the frequency of occurrence. Macoma calcarea is the most abundant species.

  14. Modulations in cell-mediated immunity of Mytilus edulis following the `Sea Empress` oil spill

    Energy Technology Data Exchange (ETDEWEB)

    Dyrynda, E.A.; Dyrynda, P.E.J.; Ratcliffe, N.A. [University of Wales Swansea (United Kingdom). School of Biological Sciences; Law, R.J.; Kelly, C.A.; Graham, K.L. [MAFF Fisheries Lab., Burnham-on-Crouch (United Kingdom); Pipe, R.K. [Plymouth Marine Lab. (United Kingdom)

    1997-02-01

    The `Sea Empress` oil tanker grounded outside Milford Haven (Wales, UK) in February 1996, spilling {approx} 70,000 tonnes of crude oil and contaminating over 100 km of coastline, causing mass mortalities and strandings of at least 11 mollusc species. Intensive field monitoring commenced after the spill, examining immunity and hydrocarbon levels in the mussel, Mytilus edulis (Mollusca: Bivalvia), a commercially-harvested species which can accumulate contaminants. Comparisons of mussels from oiled and reference sites revealed significant modulations in cell-mediated immunity. Elevations in blood cell (haemocyte) numbers and decreases in superoxide generation and phagocytosis were identified in contaminated animals. The immune response of contaminated mussels gradually improved and generally showed no significant differences compared with clean mussels after 11 weeks. By then, total hydrocarbon content in contaminated mussels had declined by 70-90%, while polycyclic aromatic hydrocarbon content had decreased by over 90%. (author)

  15. Benthic Macro-Fauna Composition and Abundance in Sombreiro River, Niger Delta, Nigeria

    Directory of Open Access Journals (Sweden)

    E.N. Ezekiel

    2011-04-01

    Full Text Available The benthic macro-fauna composition and abundance in sombreiro was studied for a period of two years (August 2007 - July2009. A total of twenty-eight species belonging to fourteen (14 families, six (6 classes and three (3 phyla were recorded in Sombreiro River. The phylum Annelida dominated with two classes (Oligochaeta and Polychaeta. Oligochaeta was represented by two families (Naididae and Lumbricidae and seven species having 25% by composition. Polychaeta was represented by seven families (Nereidae, Nepthyidae, Capitellidae, Eucinidae, Glyceridae, Arenicolidae and Syllidae and thirteen species having 46.4% by composition. The Phylum arthropoda was represented by two classes (Crustacea and inseita. Two families (Gammaridae and Penaidae having two species consisting of 7.2% were recorded, for the class crustacea. The class insecta was represented by one family (Chironomidae with one species consisting of 3.6%. The phylum Mollusca was represented by two classes (Gastropoda and Bivalvia. Gastropoda had two species with 7.2% composition and Bivalvia has three species with10.7% composition. Oligochaeta was the highest and constituted 62.0%. The others were Polychaeta (23.9%, Insecta (6.7%, Gastropoda (3.9%, Bivalvia (2.2% and Crustacea (1.3%. The mean diversity(S ranged between 11 species. Mean abundance of individuals (N was 985. Mean Margalef index (d value was 1.339. The mean value for Shannon-Wienner (H was 0.956. Mean Pielou’s index of relative density or evenness index (E was 0.986. Mean SimpsIn’s Dominance index (C was 0.623.

  16. Digenean larvae parasitizing Ruditapes decussatus (Bivalvia from Tunisianan coasts

    Directory of Open Access Journals (Sweden)

    Dhrif E.

    2015-06-01

    Full Text Available Eleven species of trematode larvae (sporocysts and cercariae of Bucephalus labracis Paggi et Orecchia, 1965 and Cercaria lata Lespes, 1857 and metacercariae of Acanthoparyphium sp. Dietz , 1909, Caecincola parvulus Marshall et Gilbert, 1905, Curtuteria australis Allison, 1979, Gymnophallus fossarum Bartoli, 1965, Gymnophallus rebecqui Bartoli, 1983, Lepocreadium pegorchis Stossich, 1901, Parazoogonus sp. Looss, 1901, Psilostomum brevicolle Creplin, 1829 and Robphildollfusium fractum Rudolphi, 1819 were found in the clam (Ruditapes decussatus from Tunisian coasts. A part from B. labracis and Cercaria lata, the other trematode species were recorded for the first time in Tunisia. The examination of the frequency of recorded parasites reveals some monthly variation. This variation is statistically significant by comparing the sampling sites. These results indicate that more frequent parasites (G. fossarum, Cercaria lata, Curtuteria australis and Acanthoparyphium sp. could be considered as biological indicators making it possible to predict the capture localities of the clams.

  17. Type specimens of Pectinidae (Bivalvia) described by Ignaz von Born

    NARCIS (Netherlands)

    Dijkstra, H.H.

    2009-01-01

    Born described in two publications (1778, 1780) the molluscs in the collection of Empress Maria Theresa (1717-1780), now in the Natural History Museum at Vienna. In this paper the Pectinidae type material is described. Ten new species were introduced of which Argopecten nucleus (Born, 1778) and Minn

  18. The behaviour of giant clams (Bivalvia: Cardiidae: Tridacninae).

    Science.gov (United States)

    Soo, Pamela; Todd, Peter A

    2014-01-01

    Giant clams, the largest living bivalves, live in close association with coral reefs throughout the Indo-Pacific. These iconic invertebrates perform numerous important ecological roles as well as serve as flagship species-drawing attention to the ongoing destruction of coral reefs and their associated biodiversity. To date, no review of giant clams has focussed on their behaviour, yet this component of their autecology is critical to their life history and hence conservation. Almost 100 articles published between 1865 and 2014 include behavioural observations, and these have been collated and synthesised into five sections: spawning, locomotion, feeding, anti-predation, and stress responses. Even though the exact cues for spawning in the wild have yet to be elucidated, giant clams appear to display diel and lunar periodicities in reproduction, and for some species, peak breeding seasons have been established. Perhaps surprisingly, giant clams have considerable mobility, ranging from swimming and gliding as larvae to crawling in juveniles and adults. Chemotaxis and geotaxis have been established, but giant clams are not phototactic. At least one species exhibits clumping behaviour, which may enhance physical stabilisation, facilitate reproduction, or provide protection from predators. Giant clams undergo several shifts in their mode of acquiring nutrition; starting with a lecithotrophic and planktotrophic diet as larvae, switching to pedal feeding after metamorphosis followed by the transition to a dual mode of filter feeding and phototrophy once symbiosis with zooxanthellae (Symbiodinium spp.) is established. Because of their shell weight and/or byssal attachment, adult giant clams are unable to escape rapidly from threats using locomotion. Instead, they exhibit a suite of visually mediated anti-predation behaviours that include sudden contraction of the mantle, valve adduction, and squirting of water. Knowledge on the behaviour of giant clams will benefit conservation and restocking efforts and help fine-tune mariculture techniques. Understanding the repertoire of giant clam behaviours will also facilitate the prediction of threshold levels for sustainable exploitation as well as recovery rates of depleted clam populations.

  19. Reproduction and sperm structure in Galeommatidae (Bivalvia, Galeommatoidea)

    DEFF Research Database (Denmark)

    Jespersen, Åse; Lützen, Jørgen

    2006-01-01

    Reproduction and/or sperm structure was studied in 18 species belonging to five genera of Galeommatidae from Phuket Island, Andaman Sea, Thailand, and Hong Kong. Incubation of the ova occurs in the inner and outer demibranchs of both gills, and sperm is most probably transferred to the ctenidial...... brood chamber as masses of agglutinated and non-encapsulated spermatozoa. The smallest specimens are males, but change into the female sex and there is a strong indication that some of the species are alternate hermaphrodites. Dwarf males occur in one species (Galeomma layardi). The sperm of all 18...... species studied are of the ent-aquasperm type with a more or less hemispherical acrosome that is tilted with respect to the long axis of the moderately elongated nucleus. It is suggested that this type of sperm affords the best autapomorphy for the family Galeommatidae....

  20. Shipwrecks, ascidians and modiolarca subpicta (Bivalvia, Mytildae, Musculinae)

    NARCIS (Netherlands)

    Gittenberger, A.; Schrieken, N.; Coolen, J.W.P.; Gittenberger, E.

    2013-01-01

    The ovulid gastropod Xandarovula patula (Pennant, 1777) was found 14.vi.2011 on the soft coral Alcyonium digitatum Linnaeus, 1758 (Dead man’s fingers) during a dive in the central North Sea on the wreck ‘Jeanette Kristina’ on the Dutch Dogger Bank. Later on additional specimens were found, sometimes

  1. Type specimens of Pectinidae (Bivalvia) described by Ignaz von Born

    NARCIS (Netherlands)

    Dijkstra, H.H.

    2009-01-01

    Born described in two publications (1778, 1780) the molluscs in the collection of Empress Maria Theresa (1717-1780), now in the Natural History Museum at Vienna. In this paper the Pectinidae type material is described. Ten new species were introduced of which Argopecten nucleus (Born, 1778) and Minn

  2. Genus Donax in the Peruvian coast (Bivalvia: Telllnoidea

    Directory of Open Access Journals (Sweden)

    Carlos Paredes

    2014-06-01

    Full Text Available In the present paper the species of Donax Linnaeus, 1758 in Peru are reviewed. The presence of 7 out of the 11 species is confirmed: D. asper Hanley. 1845; D. caelatus rothi Coan, 1983; D. obesulus Reeve, 1854; D. carinatus Hanley, 1843; D. transversus Sowerby 1,1825; D. californicus Conrad, 1837 and D. marincovichi Coan, 1983; in addition, one is recorded for the first time (D. punctatostriatus Hanley, 1843 in Peruvian waters. Information on the distribution geographical and some ecological relations is presented.

  3. Carbonate-associated sulfate in lucinid (Bivalvia) shells

    Science.gov (United States)

    Peng, Y.; Bao, H.; Anderson, L.; Engel, A. S.

    2007-12-01

    Symbiosis is a fundamental driver of evolution, with examples ranging from mitochondria in eukaryotic cells to barnacle-whale commensalism. The association between sulfur-oxidizing (thiotrophic) bacteria and the lucinid bivalve clade is particularly intriguing because the inferred antiquity of the relationship (>400 m.y.) seems at odds with the relatively loose ecologic linkage of living members. Because only half of genus-level lucinid taxa are extant, and the δ13C of shell carbonate exhibits no systematic difference between symbiotic and non- symbiotic bivalves, a new morphologically-independent proxy to determine whether fossil taxa possessed thiotrophic endosymbionts is needed. The δ34S of carbonate-associated sulfate (CAS) in bivalve shells may hold promise because biogenic carbonate incorporates sulfate into its crystal structure during biomineralization. Incorporation of bacterially derived SO42- (with a more negative δ34S value due to its reduced sulfur origin) into the lucinid-shell crystal lattice would, therefore, impart a distinctly lower δ34SCAS value than that from seawater SO42-, and would be distinguishable from CAS values of co- occurring heterotrophic bivalves. We measured CAS contents, δ34SCAS and δ18OCAS values of 15 sets of lucinid and co-occurring infaunal and epifaunal heterotrophic bivalve shells collected from modern and Cenozoic shallow marine sites. The modern bivalve shells had variable CAS content, from 100 to 2600 ppm. Epifauna often had the highest concentrations relative to the other ecological groups. The δ34SCAS and δ18OCAS clustered at values corresponding to modern seawater sulfate, but with significant scatter. There was no systematic isotope- compositional difference among all bivalves in the same habitat, or among the same lucinid, infaunal, or epifaunal groups across different sites. The fossil bivalve shells tended to preserve lower CAS concentrations and the isotope compositions further deviated from seawater values. These data suggest that 1) pore-water sulfate in shallow sediments is highly heterogeneous in its concentration and isotope composition, probably due to active microbial sulfate reduction, bioturbation, and water-pumping by bivalves and other infaunal filter feeders; 2) CAS is derived from ambient porewater or pumped-in seawater for infauna or epifauna, as well as for lucinids; and 3) CAS concentration and isotope compositions are vulnerable to later diagenetic processes.

  4. Anatomia funcional de Perna perna (Linné (bivalvia, Mytilidae Functional anatomy of Perna perna (Linné (bivalvia, Mytilidae

    Directory of Open Access Journals (Sweden)

    Walter Narchi

    1997-01-01

    Full Text Available Perna perna (Linné, 1758 occurs on the Atlantic littoral from Venezuela to Uruguay. The main organ systems were studied in the living animais, particular attention being paid to the ciliary feeding and cleansing mechanisms in the mantle cavity. The anatomy, functioning of the stomach and the ciliary sorting mechanisms are described. The siphons belong to type A (Yongf. 1948b, the ctenidia to type B( 1 (Atkins 1936c and the stomach is of type III (Purchon 1957 or Section I (Dinamani 1967 with sorting mecanisms of type A and B (Reid 1965. A general comparison was made between the genera of the Mytilidae known and some features of Mytella Soot-Ryen, 1955.

  5. Anatomia funcional de Protothaca (Leukoma pectorina (Lamarck (Bivalvia, Veneridae Functional anatomy of Protothaca (Leukoma pectorina (Lamarck (Bivalvia, Veneridae

    Directory of Open Access Journals (Sweden)

    Cordélia de Oliveira Castro Guerón

    2000-12-01

    Full Text Available Protothaca (Leukoma pectorina (Lamarck, 1818 lives from the West Indies to Santa Catarina State, Brazil, in soft muddy beaches in quiet waters of protected bays with little amounts of suspended material. A study of the functional anatomy of P. pectorina and its ecological aspects were undertaken. The anatomy and functioning of the stomach and the mechanisms for selection of particles were observed. The siphons, ctenidia, labial palps and stomach were analised and related to the animal's natural environment. The siphons belong to type B (Yonge 1948, the ctenidia to type C (1a (Atkins 1937. The ctenidia are homorhabdic (Ridewood 1903 and the stomach belongs to type V (Purchon 1960.

  6. KEANEKARAGAMAN MAKROZOOBENTOS DI PESISIR PANTAI DESA PANGGUNG KECAMATAN KEDUNG KABUPATEN JEPARA

    Directory of Open Access Journals (Sweden)

    Nisrina Arifatul Izzah

    2016-09-01

    Full Text Available Penelitian ini tentang keanekaragaman makrozoobentos di pesisir pantai Desa Panggung Kecamatan Kedung Kabupaten Jepara yang dilaksanakan pada Maret – April 2016. Tujuan penelitian ini adalah untuk mengetahui keanekaragaman makrozoobentos. Penelitian ini menggunakan metode purposive sampling dalam penentuan lokasi stasiun penelitian dan pembuatan plot mengunakan metode line transect. Stasiun penelitian terdiri dari dua stasiun yakni Stasiun I dan Stasiun II. Hasil Penelitian di temukan 6 spesies makrozoobentos terdiri dari 2 jenis dari Classis Bivalvia (Fillum Mollusca yaitu spesies Anadara granosa dan Scrobicularia plana, 2 jenis dari Classis Gastropoda (Fillum Mollusca yaitu spesies Turritella nivea dan Quoyia decollata, 1 jenis dari classis Crustacea (Fillum Arthropoda yaitu Penaeus indicus, dan 1 jenis dari Classis Polychaeta (Fillum Annelida yaitu Arenicola marina. Komposisi spesies, kepadatan populasi, kenanekaragaman dan keseragaman dari komunitas makrozoobentos bahwa stasiun I lebih tinggi dari stasiun II. Terlihat pada hasil indeks keanekaragaman (H’ makrozoobentos di stasiun I (1,52 dan stasiun II (1,47. Kedua stasiun mengindikasikan bahwa keanekaragaman rendah dan kondisi kualitas lingkungan perairan dalam keadaan setengah tercemar. kualitas perairan laut di sekitar pesisir pantai desa Panggung kecamatan Kedung kabupaten Jepara membutuhkan perhatian untuk mengurangi pencemaran lingkungan.

  7. Planorbidae, Lymnaeidae and Physidae of Peru (Mollusca: Basommatophora

    Directory of Open Access Journals (Sweden)

    Paraense W Lobato

    2003-01-01

    Full Text Available In the course of several trips to Peru I had the opportunity of collecting topotypic specimens of Biomphalaria andecola (Orbigny, 1835, B. helophila (Orbigny, 1835, B. pucaraensis (Preston, 1909, Drepanotrema limayanum (Lesson, 1830, D. kermatoides (Orbigny, 1835, and Lymnaea viatrix Orbigny, 1835, besides B. tenagophila (Orbigny, 1835, Helisoma trivolvis (Say, 1817, H. duryi (Wetherby, 1879, Physa acuta Draparnaud, 1801, and seemingly P. peruviana Gray, 1828. B. pucaraensis is considered a junior synonym of B. peregrina (Orbigny, 1835.

  8. Chitons (Mollusca, Polyplacophora) from Alacranes Reef, Yucatan, Mexico.

    Science.gov (United States)

    Reyes-Gómez, Adriana; Ortigosa, Deneb; Simões, Nuno

    2017-01-01

    This study represents the first comprehensive chiton study from Alacranes Reef, the largest reef system in the Gulf of Mexico. Nine chiton species were found in seven localities within the area, in the intertidal and subtidal to 12 m depth. SEM examination of C. janeirensis, A. hemphilli, T. schrammi and C. floridanus, showed variations in the sculpture and radular teeth morphology when compared to specimens of the same species from Florida Keys, Bahamas and Puerto Rico. The distribution ranges of T. schrammi, L. liozonis and S. floridana are extended into the south-western area of the Gulf of Mexico. Altogether, combining previous literature and the present survey, reports eleven chiton species which have now been recorded within the Alacranes reef area.

  9. Phylogenetics, development, and Cenozoic paleontology of Buccinidae (Mollusca:Gastropoda)

    OpenAIRE

    2009-01-01

    The buccinid gastropods (family Buccinidae) are a species-rich clade of mostly North Pacific taxa with an abundant fossil record that dates to the Cretaceous. Here, the evolution, systematics, and biology of fossil and extant members of this family are treated using a variety of analytical and methodological approaches. In chapter one, a new fossil species of Bruclarkia, an endemic eastern Pacific buccinid from the Eocene, Oligocene, and Miocene, is described from the Astoria Formation of the...

  10. Notes on a few Opisthobranch Mollusca from Surinam (Guianas)

    NARCIS (Netherlands)

    Nijssen-Meyer, J.

    1965-01-01

    The Opisthobranchs dealt with in this paper were entrusted to me by Dr. C. O. van Regteren Altena, Rijksmuseum van Natuurlijke Historie, Leiden, and belong to that museum. They are part of a large collection of marine molluscs from Surinam of which Dr. van Regteren Altena intends to publish an annot

  11. New data on southern African Achatinidae (Mollusca, Gastropoda Pulmonata)

    NARCIS (Netherlands)

    Bruggen, van A.C.

    1972-01-01

    Increasing knowledge of the genital anatomy of the species of the African land snail family Achatinidae has greatly improved our understanding of the delimitation of the species and the intricate interrelationships of the various taxa (Mead, 1950). The genitalia of many achatinids are still unknown

  12. p63 gene structure in the phylum mollusca.

    Science.gov (United States)

    Baričević, Ana; Štifanić, Mauro; Hamer, Bojan; Batel, Renato

    2015-08-01

    Roles of p53 family ancestor (p63) in the organisms' response to stressful environmental conditions (mainly pollution) have been studied among molluscs, especially in the genus Mytilus, within the last 15 years. Nevertheless, information about gene structure of this regulatory gene in molluscs is scarce. Here we report the first complete genomic structure of the p53 family orthologue in the mollusc Mediterranean mussel Mytilus galloprovincialis and confirm its similarity to vertebrate p63 gene. Our searches within the available molluscan genomes (Aplysia californica, Lottia gigantea, Crassostrea gigas and Biomphalaria glabrata), found only one p53 family member present in a single copy per haploid genome. Comparative analysis of those orthologues, additionally confirmed the conserved p63 gene structure. Conserved p63 gene structure can be a helpful tool to complement or/and revise gene annotations of any future p63 genomic sequence records in molluscs, but also in other animal phyla. Knowledge of the correct gene structure will enable better prediction of possible protein isoforms and their functions. Our analyses also pointed out possible mis-annotations of the p63 gene in sequenced molluscan genomes and stressed the value of manual inspection (based on alignments of cDNA and protein onto the genome sequence) for a reliable and complete gene annotation.

  13. Upper Cambrian chitons (Mollusca, polyplacophora) from Missouri, USA

    Science.gov (United States)

    Pojeta, J.; Vendrasco, M.J.; Darrough, G.

    2010-01-01

    Numerous new specimens reveal a greater presence of chitons in Upper Cambrian rocks than previously suspected. Evidence is presented showing that the chiton esthete sensory system is present in all chiton species in this study at the very beginning of the known polyplacophoran fossil record. The stratigraphic occurrences and paleobiogeography of Late Cambrian chitons are documented. The 14 previously-named families of Cambrian and Ordovician chitons are reviewed and analyzed. Aulochitonidae n. fam. is defined, based on Aulochiton n. gen.; A. sannerae n. sp. is also defined. The long misunderstood family Preacanthochitonidae and its type genus Preacanthochiton Bergenhayn, 1960, are placed in synonymy with Mattheviidae and Chelodes Davidson & King, 1874, respectively; Eochelodes Marek, 1962, also is placed in synonymy with Chelodes, and Elongata Stinchcomb & Darrough, 1995, is placed in synonymy with Hemithecella Ulrich & Bridge, 1941. At the species level, H. elongata Stinchcomb & Darrough, 1995, and Elongata perplexa Stinchcomb & Darrough, 1995, are placed in synonymy with H. eminensis Stinchcomb & Darrough, 1995. The Ordovician species H. abrupta Stinchcomb & Darrough, 1995, is transferred to the genus Chelodes as C. abrupta (Stinchcomb & Darrough, 1995). The Ordovician species Preacanthochiton baueri Hoare & Pojeta, 2006, is transferred to the genus Helminthochiton as H. ? baueri (Hoare & Pojeta, 2006). The Ordovician species H. marginatus Hoare & Pojeta, 2006, is transferred to the genus Litochiton as L. marginatus (Hoare & Pojeta, 2006). Matthevia walcotti Runnegar, Pojeta, Taylor, & Collins, 1979, is treated as a synonym of Hemithecella expansa Ulrich & Bridge, 1941. In addition, other multivalved Cambrian mollusks are discussed; within this group, Dycheiidae n. fam. is defined, as well as Paradycheia dorisae n. gen. and n. sp. Cladistic analysis indicates a close relationship among the genera here assigned to the Mattheviidae, and between Echinochiton Pojeta, Eernisse, Hoare, & Henderson, 2003, and mattheviids. The results suggest treating these taxa as stem-lineage chitons, and do not support the hypothesis that they are aplacophorans.

  14. Two new species of Enidae (Mollusca: Gastropoda: Pupillacea) from Turkey

    NARCIS (Netherlands)

    Gittenberger, E.

    1986-01-01

    Two new species of Enidae, viz. Zebrina (Ramusculus) mienisi spec. nov. and Turanena tuccari spec. nov., are described from the Turkish provinces of Erzurum and Antalya, respectively. The former species is unknown anatomically and, therefore, its (sub)generic assignment is uncertain. The latter new

  15. Biodiversity and biogeography of Antarctic and sub-Antarctic mollusca

    Science.gov (United States)

    Linse, Katrin; Griffiths, Huw J.; Barnes, David K. A.; Clarke, Andrew

    2006-04-01

    For many decades molluscan data have been critical to the establishment of the concept of a global-scale increase in species richness from the poles to the equator. Low polar diversity is key to this latitudinal cline in diversity. Here we investigate richness patterns in the two largest classes of molluscs at both local and regional scales throughout the Southern Ocean. We show that biodiversity is very patchy in the Southern Ocean (at the 1000-km scale) and test the validity of historical biogeographic sub-regions and provinces. We used multivariate analysis of biodiversity patterns at species, genus and family levels to define richness hotspots within the Southern Ocean and transition areas. This process identified the following distinct sub-regions in the Southern Ocean: Antarctic Peninsula, Weddell Sea, East Antarctic—Dronning Maud Land, East Antarctic—Enderby Land, East Antarctic—Wilkes Land, Ross Sea, and the independent Scotia arc and sub Antarctic islands. Patterns of endemism were very different between the bivalves and gastropods. On the basis of distributional ranges and radiation centres of evolutionarily successful families and genera we define three biogeographic provinces in the Southern Ocean: (1) the continental high Antarctic province excluding the Antarctic Peninsula, (2) the Scotia Sea province including the Antarctic Peninsula, and (3) the sub Antarctic province comprising the islands in the vicinity of the Antarctic Circumpolar Current.

  16. Notes on Cancellaria minima Reeve (Mollusca: Neogastropoda: Cancellariacea)

    NARCIS (Netherlands)

    Verhecken, A.

    1984-01-01

    Cancellaria minima Reeve, 1856, is redescribed after three syntypes and 59 shells recently collected near Madeira and off Morocco. The few literature data concerning this poorly known species are summarized. Its range appears to be situated between 27° and 37°N and 5° and 17°W, as far as known mainl

  17. A new dicyemid from octopus hubbsorum (Mollusca: Cephalopoda: Octopoda)

    OpenAIRE

    Castellanos-Martínez, Sheila; Gómez, M. Carmen; Hochberg, F. G.; Gestal, C.; Furuya, Hidetaka

    2011-01-01

    A new species of dicyemid mesozoan is described from Octopus hubbsorum Berry, 1953, collected in the south of Bahia de La Paz, Baja California Sur, Me´xico. Dicyema guaycurense n. sp. is a medium-size species that reaches about 1,600 mm in length. It occurs in folds of the renal appendages. The vermiform stages are characterized as having 22 peripheral cells, a conical calotte, and an axial cell that extends to the base of the propolar cells. Infusoriform embryos consist of 39 cells;...

  18. Host specificity and phylogenetic relationships among Atlantic Ovulidae (Mollusca: Gastropoda)

    NARCIS (Netherlands)

    Reijnen, B.T.; Hoeksema, B.W.; Gittenberger, E.

    2010-01-01

    Ovulid gastropods and their octocoral hosts were collected along the leeward coast of Curaçao, Netherlands Antilles. New molecular data of Caribbean and a single Atlantic species were combined with comparable data of Indo-Pacific Ovulidae and a single East-Pacific species from GenBank. Based on two

  19. Host specificity and phylogenetic relationships among Atlantic Ovulidae (Mollusca: Gastropoda)

    OpenAIRE

    2010-01-01

    Ovulid gastropods and their octocoral hosts were collected along the leeward coast of Curaçao, Netherlands Antilles. New molecular data of Caribbean and a single Atlantic species were combined with comparable data of Indo-Pacific Ovulidae and a single East-Pacific species from GenBank. Based on two DNA markers, viz. CO-I and 16S, the phylogenetic relationships among all ovulid species of which these data are available are reconstructed. The provisional results suggest a dichotomy between the ...

  20. On Pomacea canaliculata (Lamarck, 1822 (Mollusca; Pilidae: Ampullariidae

    Directory of Open Access Journals (Sweden)

    Silvana C. Thiengo

    1993-03-01

    Full Text Available This paper deals with the morphology of Pomacea caniculata (Lamarck, 1822 collected at Corrientes, Argentina. Comparison is made with Pomacea lineata (Spix, 1827 and Pomacea sordida (Swainson, 1823. The shell is globose, heavy, with greenish or horn-colored periostracum and dark spiral bands; apex subelevated, 5-6 whorls increasing rather rapidly and separated by very deep suture. Aperture large, rounded to subelongated; lip sometimes reddish; umbilicus large and deep; operculum corneous, entirely closing the aperture. Ratios: shell width/shell length = 0.78-0.96 (mean 0.86; aperture length/shell length = 0.68-0.77 (mean 0.72. Radula similar to other congeneric species. Testis and spermiduct as in P. lineata and P. sordida; prostate cylindric and short, cream in color as the testis. Penial sheath straight bearing a central outer gland deeply embedded in the tissue of its basal portion and a large wrinkled gland occupying 2/3 of the distal tip of its inner surface; the rigth margin of the sheath overlaps the left one until 2/3 of its proximal end. Female reproductive apparatus similar to that P. lineata; vestigial male copulatory apparatus (penis and its sheath present in all females examined.

  1. Miscellaneous notes on Southern African Gastropoda Euthyneura (Mollusca)

    NARCIS (Netherlands)

    Bruggen, van A.C.

    1967-01-01

    SUMMARY The following new distribution records of southern African terrestrial molluscs seem to be of particular interest: Pupilla fontana (Krss.), Rachis jejuna (M. & P.), Guppya rumrutiensis (Prest.), Xerocerastus burchelli (Gray) (all four new for Rhodesia), Euonyma damarica Jaeck. (new for Cape

  2. Variation in foraging activity of Acanthochitona garnoti (Mollusca ...

    African Journals Online (AJOL)

    At all sites, chitons spent a significantly greater (p < 0,00 I; multi factor analysis of ... groups mean groups. Aeolean pi

  3. Imposex in endemic volutid from Northeast Brazil (Mollusca: Gastropoda

    Directory of Open Access Journals (Sweden)

    Ítalo Braga de Castro

    2008-10-01

    Full Text Available Imposex is characterized by the development of masculine sexual organs in neogastropod females. Almost 120 mollusk species are known to present imposex when exposed to organic tin compounds as tributyltin (TBT and triphenyltin (TPT. These compounds are used as biocide agents in antifouling paints to prevent the incrustations on boats. Five gastropod species are known to present imposex in Brazil: Stramonita haemastoma, Stramonita rustica, Leucozonia nassa, Cymathium parthenopeum and Olivancillaria vesica. This paper reports the first record of imposex observed in the endemic gastropod Voluta ebraea from Pacheco Beach, Northeast Brazil. Animals presenting imposex had regular female reproductive organs (capsule gland, oviduct and sperm-ingesting gland and an abnormal penis. As imposex occurs in mollusks exposed to organotin compounds typically found at harbors, marinas, shipyards and areas with high shipping activities, probably contamination of Pacheco Beach is a consequence of a shipyard activity located in the nearest areas.O imposex caracteriza-se pelo surgimento de estruturas sexuais masculinas, em fêmeas de gastrópodes. Cerca de 120 espécies de moluscos que exibem o fenômeno quando expostas a contaminação por compostos orgânicos de estanho tais como o Tributilestanho (TBT e o Trifenilestanho (TPT. Esses compostos são utilizados, sobretudo em embarcações, no intuito de evitar a bioincrustração que danifica as embarcações e eleva os custos das viagens marítimas. No Brasil se conhecem 5 espécies de moluscos gastrópodes que manifestam imposex, são elas: Stramonita haemastoma, Stramonita rustica, Leucozonia nassa, Cymathium parthenopeum e Olivancillaria vesica. No Nordeste, monitoramentos da contaminação por organoestânicos foram realizados utilizando o imposex em gastrópodes como biomarcador. O presente estudo tem por objetivo notificar a primeira ocorrência de imposex na espécie endêmica do Nordeste brasileiro, Voluta ebraea. De um total de 11 animais observados, duas fêmeas apresentaram imposex, provenientes da Praia do Pacheco no litoral do Ceará. Observou-se nesses indivíduos a presença de glândula de cápsulas, ovidutos e receptáculo seminal concomitantemente ao pênis o que caracteriza o imposex. Como o imposex só se manifesta em moluscos expostos a compostos organoestânicos tipicamente encontrados em portos, marinas, estaleiros e locais com grande fluxo de embarcações atribui-se a origem dessa contaminação provavelmente a um estaleiro localizado nas proximidades da área de coleta.

  4. Planorbidae, Lymnaeidae and Physidae of Ecuador (Mollusca: Basommatophora

    Directory of Open Access Journals (Sweden)

    W Lobato Paraense

    2004-06-01

    Full Text Available In the course of a trip to Ecuador I had the opportunity of collecting topotypic specimens of the following nominal species of pulmonate molluscs: Biomphalaria cousini Paraense, 1966; Planorbis equatorius Cousin, 1887; P. canonicus Cousin, 1887; Lymnaea cousini Jousseaume, 1887 and P. boetzkesi Miller, 1879. Additional findings were: Helisoma trivolvis (Say, 1817, Biomphalaria peregrina (Orbigny 1835, Drepanotrema anatinum (Orbigny, 1835, D. kermatoides (Orbigny, 1835, D. lucidum (Pfeiffer, 1839, D. surinamense (Clessin, 1884, Lymnaea columella Say, 1817 and Physa acuta Draparnaud, 1805. P. boetzkesi and P. canonicus are considered junior synonyms of Gyraulus hindsianus (Dunker, 1848 and Biomphalaria peregrina (Orbigny, 1835, respectively.

  5. First molecular phylogeny of the subfamily Polycerinae (Mollusca, Nudibranchia, Polyceridae)

    Science.gov (United States)

    Palomar, Gemma; Pola, Marta; Garcia-Vazquez, Eva

    2014-03-01

    The subfamily Polycerinae includes four genera with around 46 species described to date. This subfamily is characterized by a limaciform body, which may have simple tentacular processes on the margin of the oral veil. Phylogenetic relationships between the genera of the subfamily Polycerinae (Polyceridae) have not yet been studied, and therefore, the only available information is based on morphological descriptions. The present study reports the first phylogenetic analysis of Polycerinae based on the mitochondrial genes cytochrome oxidase subunit I and the large ribosomal subunit (16S rRNA) using maximum likelihood and Bayesian methods. Our results showed that Polycerinae is monophyletic, but the relationships within the subfamily as well as within Polycera remain unresolved. A key finding of this study is that there are clearly two sympatric species of Polycera present in South Africa: Polycera capensis Quoy and Gaimard, 1824 also found in Australia and an undescribed Polycera sp. On the other hand, the studied specimens of the genus Gymnodoris were clustered within Polycerinae, reopening the problem of the systematic position of this genus. Additional genes and species of Polycerinae and Gymnodoris would provide more information and probably fully resolve this situation.

  6. Chitons (Mollusca, Polyplacophora) from Alacranes Reef, Yucatan, Mexico

    Science.gov (United States)

    Reyes-Gómez, Adriana; Ortigosa, Deneb; Simões, Nuno

    2017-01-01

    Abstract This study represents the first comprehensive chiton study from Alacranes Reef, the largest reef system in the Gulf of Mexico. Nine chiton species were found in seven localities within the area, in the intertidal and subtidal to 12 m depth. SEM examination of C. janeirensis, A. hemphilli, T. schrammi and C. floridanus, showed variations in the sculpture and radular teeth morphology when compared to specimens of the same species from Florida Keys, Bahamas and Puerto Rico. The distribution ranges of T. schrammi, L. liozonis and S. floridana are extended into the south-western area of the Gulf of Mexico. Altogether, combining previous literature and the present survey, reports eleven chiton species which have now been recorded within the Alacranes reef area. PMID:28769624

  7. Phylogenetic analysis of Biomphalaria tenagophila (Orbigny, 1835 (Mollusca: Gastropoda

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    Liana K Jannotti-Passos

    2010-07-01

    Full Text Available Mitochondrial DNA of Biomphalaria tenagophila, a mollusc intermediate host of Schistosoma mansoni in Brazil, was sequenced and characterised. The genome size found for B. tenagophila was 13,722 bp and contained 13 messenger RNAs, 22 transfer RNAs (tRNA and two ribosomal RNAs (rRNA. In addition to sequencing, the mitochondrial DNA (mtDNA genome organization of B. tenagophila was analysed based on its content and localization of both coding and non-coding regions, regions of gene overlap and tRNA nucleotide sequences. Sequences of protein, rRNA 12S and rRNA 16S nucleotides as well as gene organization were compared between B. tenagophila and Biomphalaria glabrata, as the latter is the most important S. mansoni intermediate host in Brazil. Differences between such species were observed regarding rRNA composition. The complete sequence of the B. tenagophila mitochondrial genome was deposited in GenBank (accession EF433576. Furthermore, phylogenetic relationships were estimated among 28 mollusc species, which had their complete mitochondrial genome deposited in GenBank, using the neighbour-joining method, maximum parsimony and maximum likelihood bootstrap. B. tenagophila was positioned at a branch close to B. glabrata and Pulmonata molluscs, collectively comprising a paraphyletic group, contrary to Opistobranchia, which was positioned at a single branch and constituted a monophyletic group.

  8. Description of the ootheca of Turbinella laevigata (Mollusca, Gastropoda

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    Helena Matthews-Cascon

    2009-04-01

    Full Text Available Turbinella laevigata is found since the intertidal zone up to 40 m depth, being endemic of Brazil where it occurs from the state of Amapá to the state of Espirito Santo. The objective of this study was to describe the ootheca of this species. Fifteen samples collected in the Olho d'Água Beach, City of Icapuí and Fleixeiras Beach, City of Trairí, both in Ceará State, Northeast Brazil, were studied. The spawns were composed by 15 +/- 1.4 SD capsules and had 63 +/- 6.4 SD mm of length with 41 +/- 2.5 SD mm of width. They had a convex and a concave surface, and plaited edges that drew out until the basal membrane, to which they joined forming a medial ridge. This species apparently produced a high amount of nurse eggs. The early juveniles measured 6.4 +/- 0.7 SD mm of length and they presented a protoconch with three whorls.Turbinella laevigata é encontrada desde a zona entre marés até 40 m de profundidade, sendo endêmica do Brasil onde ocorre desde o Estado do Amapá até o Espírito Santo. O objetivo deste estudo foi descrever a ooteca de Turbinella laevigata. Quinze amostras foram coletadas na Praia de Olho d'Água, Município de Icapuí e na Praia de Flexeiras, Município do Trairí, ambos no Estado do Ceará, Nordeste do Brasil, foram estudadas. As desovas de T. laevigata foram compostas por 15 +/- 1.4 SD cápsulas e mediram 63 +/- 6.4 SD mm de comprimento e 41 +/- 2.5 SD mm de largura. Todas as cápsulas estavam fixadas pela membrana basal, a qual tinha a extremidade modificada para se prender ao substrato. Elas possuem uma superfície concava e outra convexa, apresentando margens pregueadas, que se prolongavam até a membrana basal, à qual se uniam formando uma prega. Esta espécie aparentemente produz uma grande quantidade de ovos nutritivos. A concha dos juvenis mediu 6.4 +/- 0.7 SD mm de comprimento e apresentou uma protoconcha com 3 voltas.

  9. Protandric hermaphroditism in the bivalve Arca noae (Mollusca: Arcidae

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    G. BELLO

    2013-02-01

    Full Text Available Following the histological analysis of Arca noae samples from the south-western Adriatic Sea, five hermaphroditic specimens were found out of 168 sexed individuals (3.0%. The hermaphrodite gonads showed the co-occurrence of male and female germ cells within the same acini, i.e. both spermatozoa in the lumen and oogonia lining its wall. Oogonia increased in size through winter, thus suggesting that the direction of sex change is from male to female. Both the biometrical analyses and theoretical considerations strongly suggest that A. noae is an obligate protandric species.

  10. Loss of trematode parthenitae in Planorbella trivolvis (Mollusca: Gastropoda).

    Science.gov (United States)

    Sears, B F; Rohr, J R

    2013-08-01

    Infection by trematode parthenitae (larval, asexual trematodes) has severe consequences for molluscan hosts, resulting in cessation of reproduction and early mortality. Here we present evidence that the freshwater snail Planorbella trivolvis can lose infections by trematode parthenitae. Of 8 P. trivolvis infected by reniferin parthenitae, 6 died within 2 wk, whereas the remaining 2 snails lost their infections within 82 days after initial examination. This phenomenon might suggest that molluscs can resist established trematode infections (i.e., "self-cure") or at least out-survive some trematode parthenitae.

  11. New records of opisthobranchs from Lakshadweep, India (Mollusca: Heterobranchia

    Directory of Open Access Journals (Sweden)

    D. Apte

    2014-03-01

    Full Text Available All India Coordinated Project on Taxonomy (AICOPTAX, an initiative of Ministry of Environment and Forests allowed the authors to study opisthobranch fauna of the west coast of India. During the present study, nine species of opisthobranchs are reported for the first time from Lakshadweep of which six are new records to India.

  12. Diversity of Indo-West Pacific Siphonaria (Mollusca: Gastropoda: Euthyneura).

    Science.gov (United States)

    Dayrat, Benoît; Goulding, Tricia C; White, Tracy R

    2014-03-14

    Species of the limpet genus Siphonaria (Gastropoda: Euthyneura) are commonly found in the rocky intertidal, worldwide, except in the Arctic. In total, 205 species-group names are available and not permanently invalid. However, estimating the actual species diversity of Siphonaria has remained challenging, mainly because past authors have interpreted differently the variation of shell characters, resulting in different taxonomic accounts. Species diversity of Siphonaria is evaluated for the first time here based on DNA sequence data (three mitochondrial gene fragments: COI, 12S, and 16S) and a large sampling focusing on the tropical and subtropical Indo-West Pacific (from eastern Africa to Hawaii): new sequences are provided for 153 individuals, 123 of which were collected from 93 locations throughout the Indo-West Pacific. In total, 41 species (molecular units) are recognized worldwide (31 from the Indo-West Pacific), all of which are strongly supported. Potential names are discussed for those 41 species, based on traditional taxonomy. The shells of 66 of the individuals from which DNA was extracted are illustrated: intra- and inter-specific variation is documented in detail and discussed in the light of new molecular results. It is shown that many species could hardly be identified based on the shell only, because the variation of shell characters is too high and overlaps between species. Geographically, no species is found across the entire Indo-West Pacific, where quite a few species seem to be endemic to restricted areas. The biogeography of Siphonaria in the Indo-West Pacific is compared to other groups.

  13. Recharacterization of Synapterpes (S. hanleyi (Pfeiffer (Mollusca, Gastropoda, Stylommatophora, Subulinidae

    Directory of Open Access Journals (Sweden)

    Norma Campos Salgado

    1999-01-01

    Full Text Available Synapterpes (S. hanleyi (Pfeiffer, 1846 is characterized by anatomy, synonymy and geographical distribution. Shell and soft parts were studied and important taxonomic characters evaluated and illustrated. These studies give conditions to characterize the species and include it in the genus Synapterpes Pilsbry, 1896 and distinguish S. hanleyi from the other species of Synapterpes s.s. known only by their shells, respectively from Brazil and Colombia: S.(S. coronatus (Pfeiffer, 1846 and S.(S. wallisi (Mousson, 1869.

  14. A new species of Anna (Mollusca: Neogastropoda: Buccinidae from Brazil

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    José Coltro

    2013-02-01

    Full Text Available Anna capixaba, a new species found in depths of 45-60 m off the coast of the state of Espírito Santo, southeastern Brazil, is herein described. The new species is mainly characterized by a teleoconch of 4.5 whorls, weakly demarcated from the protoconch; sculptured by rounded, prominent, narrowly-separated, spiral threads; outer lip with 5-6 teeth, posterior tooth stronger; columella with two plicae, smooth.

  15. The Genus Theba (Mollusca: Gastropoda: Helicidae), Systematics and Distribution

    NARCIS (Netherlands)

    Gittenberger, E.; Ripken, Th. E.J.

    1987-01-01

    Our knowledge concerning taxonomy and zoogeography of the fossil and recent species of the helicid genus Theba is summarized and enlarged. The fossil T. arinagae spec. nov. is described from Gran Canaria. The recent T. andalusica spec. nov. and T. sacchii spec. nov. are described from the southernmo

  16. Recharacterization of Strophocheilus miersi Da Costa (Mollusca, Pulmonata, Strophocheilidae

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    Meire Silva Pena

    2004-03-01

    Full Text Available Stropocheilus miersi Da Costa, 1904 is recharacterized by the conchology and morphology of the soft parts, the latter for the first time. Palial complex, reproductive and digestive systems provide important characteristics to enrich the knowledge of the genus Strophocheilus Spix, 1827. The presence of four arched folds in the posterior region of the pediose mass and the morphology of the suprapediose gland offered more data to identify and diagnose the species.Strophocheilus miersi Da Costa, 1904 é recaracterizado pela conquiologia e pela primeira vez a morfologia das partes moles. Complexo palial, sistemas reprodutor e digestivo forneceram importantes caracteres para enriquecer o conhecimento sobre Strophocheilus Spix, 1827. A presençca de quatro pregas arqueadas na região posterior da massa cefalopediosa e a morfologia da glândula suprapediosa acrescentaram dados para a diagnose da espécie.

  17. Protandric hermaphroditism in the bivalve Arca noae (Mollusca: Arcidae

    Directory of Open Access Journals (Sweden)

    G. BELLO

    2013-04-01

    Full Text Available Following the histological analysis of Arca noae samples from the south-western Adriatic Sea, five hermaphroditic specimens were found out of 168 sexed individuals (3.0%. The hermaphrodite gonads showed the co-occurrence of male and female germ cells within the same acini, i.e. both spermatozoa in the lumen and oogonia lining its wall. Oogonia increased in size through winter, thus suggesting that the direction of sex change is from male to female. Both the biometrical analyses and theoretical considerations strongly suggest that A. noae is an obligate protandric species.

  18. Reestablecimiento de Choromytilus chorus (Molina, 1782) (Bivalvia: Mytilidae) en el norte de Chile Reestablishment of Choromytilus chorus (Molina, 1782) (Bivalvia: Mytilidae) in northern Chile

    OpenAIRE

    Miguel Avendaño; Marcela Cantillánez

    2011-01-01

    Hasta fines del siglo pasado no existían registros de la presencia de Choromytilus chorus al norte de los 23°S, pese a antecedentes que señalaban su existencia en épocas pasadas. Ciertos cambios relacionados con las masas de agua costeras de esta zona, habrían generado la ausencia o escasez que presentaba el entorno costero actual. Sin embargo, hace una década atrás, su presencia en el norte de Chile, comienza a tener connotación pesquera. En el presente trabajo se confirma su reestablecimien...

  19. Reestablecimiento de Choromytilus chorus (Molina, 1782 (Bivalvia: Mytilidae en el norte de Chile Reestablishment of Choromytilus chorus (Molina, 1782 (Bivalvia: Mytilidae in northern Chile

    Directory of Open Access Journals (Sweden)

    Miguel Avendaño

    2011-07-01

    Full Text Available Hasta fines del siglo pasado no existían registros de la presencia de Choromytilus chorus al norte de los 23°S, pese a antecedentes que señalaban su existencia en épocas pasadas. Ciertos cambios relacionados con las masas de agua costeras de esta zona, habrían generado la ausencia o escasez que presentaba el entorno costero actual. Sin embargo, hace una década atrás, su presencia en el norte de Chile, comienza a tener connotación pesquera. En el presente trabajo se confirma su reestablecimiento en las regiones de Antofagasta y Tarapacá, mediante prospecciones realizadas en seis lugares donde se registró su presencia, así como mediante la captación de semilla en colectores suspendidos. Se indica interacción con Aulacomya ater, a la cual ha desplazado a estratos más profundos, mientras que su reestablecimiento, iniciado en las regiones de Atacama y Antofagasta, y que se amplió posteriormente a la región de Tarapacá; permite postular la hipótesis que la dinámica de estos bancos, respondería a una estructura de metapoblación, dado el sistema de corrientes y vientos que predominan en la zona norte, permitiendo la advección larval de poblaciones existentes en la región de Coquimbo.Despite indications of its presence in past ages, until the end of the last century, no records showed Choromytilus chorus north of 23°S. Certain changes related to coastal water masses in the zone could be responsible for the present lack or scarcity of this species in the coastal area. However, a decade ago, this species appeared in northern Chile in the context of fisheries. This study confirms the re-establishment of C. chorus in the Antofagasta and Tarapaca regions through surveys at six sites where the species had been registered and spat collection using suspended collectors. This species has interacted with Aulacomya ater, displacing it towards deeper habitats. The re-establishment of C. chorus began in the Atacama and Antofagasta regions and later extended to the Tarapaca region. Thus, we hypothesize that the dynamics of these shoals correspond to a metapopulation structure that has allowed larval advection, given the current system and predominant winds in the northern zone, from populations existing in the Coquimbo region.

  20. 上海苏州河大型底栖动物的研究%A study on macro-invertebrate of the Suzhou River, Shanghai.

    Institute of Scientific and Technical Information of China (English)

    刘国才; 赖伟; 殷浩文; 顾福康

    2001-01-01

    苏州河白鹤至浙江路段6个采样断面大型底栖动物隶属于环节动物门(Annelida)、软体动物门(Mollusca)及节肢动物门(Arthropoda).其中寡毛纲(Oligochaeta)4种、蛭纲(Hirudinea)2种、腹足纲(Gastropoda)5种、双壳纲(Bivalvia)2种及昆虫纲摇蚊科幼虫(Chironomidae)与潜蝇蛹(Agromyzigae)(未定种).随着底质污染的加重,群落结构趋于简化.种类少、高度耐污是存活大型底栖动物的显著特点.从白鹤至华槽断面,高度耐污的霍甫水丝蚓(Limnodrilus hoffmeisteri)数量趋于增加,并在华槽断面形成明显数量高峰;北新泾、武宁路河段底质污染严重,环节动物、软体动物消失;浙江路断面受黄浦江"逆流"影响,寡毛纲动物再度出现,并形成一定数量.%Macro-invertebrate from Annelida, Mollusca and Arthropoda were found in six sections from Baihe to Zhejiang road in the Suzhou River, among which four species were from Oligochaeta, two species from Hirudinea, five species from Gastropoda, two species from Bivalvia and several species from Insecta (unidentified). The community structure of macro-invertebrates became simple with the sediment pollution getting heavier. Limited species with high pollution resistibility were the characteristics of the species survival. The amounts of Limnodrilus hoffmeisteri with high pollution resistibility increased gradually from Baihe to Huacao section, and reached a peak in Huacao section; species from An-nelida, Mollusca were not found in Beixinjing and Wuninglu sections due to heavy sediment pollution; species from Oli-gochaeta were found again and had certain numbers in Zhejiang road section as the result of the effect of courterflow of the Huangpu River.

  1. ORCONECTES LIMOSUS IN THE CZECH REPUBLIC

    Directory of Open Access Journals (Sweden)

    DURIS Z.

    2006-01-01

    Full Text Available Several cases of epibiosis by macro-invertebrates on Orconectes limosus were recorded during our research on the biology of populations of this invasive crayfish species in the Czech Republic. (1 In 2001, we observed a high infestation of O. limosus by native species of branchiobdellidan worms (Annelida: Branchiobdellidae in the river Elbe at Obríství (Central Bohemia. Four European Branchiobdella species were collected and identified from three crayfish specimens: B. pentodonta (52%, B. balcanica (24%, B. parasita (18% and B. hexodonta (6%. In 2003, only a single crayfish was found bearing branchiobdellidans (5 specimens of B. parasita only in the same locality. No branchiobdellidans on O. limosus have been confirmed since. (2 A flooded sandpit Lhota near Brandýs nad Labem is the only Czech locality where the settlement of Dreissena polymorpha (Mollusca, Bivalvia on an O. limosus body was recorded. The crayfish lost the bivalves by moulting in summer; new mussels had settled by late summer and early autumn. (3 Females of the fish louse Argulus cf. foliaceus (Crustacea: Branchiura lay egg-strings on any hard substrate, including the crayfish exoskeleton. Such egg-masses were found on up to 65% of O. limosus specimens in the above-mentioned sandpit. (4 Bryozoan colonies of Plumatella repens were found twice on crayfish in the rivers Elbe (Labe and Cidlina.

  2. A neurophylogenetic approach provides new insight to the evolution of Scaphopoda.

    Science.gov (United States)

    Sumner-Rooney, Lauren H; Schrödl, Michael; Lodde-Bensch, Eva; Lindberg, David R; Heß, Martin; Brennan, Gerard P; Sigwart, Julia D

    2015-01-01

    The position of scaphopods in molluscan phylogeny remains singularly contentious, with several sister relationships supported by morphological and phylogenomic data: Scaphopoda + Bivalvia (Diasoma), Scaphopoda + Cephalopoda (Variopoda), and Scaphopoda + Gastropoda. Nervous system architecture has contributed significant insights to reconstructing phylogeny in the Mollusca and other invertebrate groups, but a modern neurophylogenetic approach has not been applied to molluscs, hampered by a lack of clearly defined homologous characters that can be unequivocally compared across the radical body plan disparity among the living clades. We present the first three-dimensional reconstruction of the anterior nervous system of a scaphopod, Rhabdus rectius, using histological tomography. We also describe a new putative sensory organ, a paired and pigmented sensory mantle slit. This structure is restricted to our study species and not a general feature of scaphopods, but it forms an integral part of the description of the nervous system in R. rectius. It also highlights the potential utility of neuro-anatomical characters for multiple levels of phylogenetic inference beyond this study. This potential has not previously been exploited for the thorny problem of molluscan phylogeny. The neuroanatomy of scaphopods demonstrates a highly derived architecture that shares a number of key characters with the cephalopod nervous system, and supports a Scaphopoda + Cephalopoda grouping.

  3. 中国近海"近江牡蛎"的分类和订名%Classification of "Jin jiang" oysters in China

    Institute of Scientific and Technical Information of China (English)

    王海艳; 郭希明; 刘晓; 张国范; 张素萍; 徐凤山

    2007-01-01

    @@ 牡蛎(Ostreidae)属软体动物门(Mollusca)、双壳纲(Bivalvia)、珍珠贝目(Pterioidae),为世界性广分布种类.由于其肉味鲜美,营养丰富,从远古时代就被人类所食用,具有很高的经济价值,是世界各国海水养殖业重要的养殖对象,是目前中国乃至世界产量最大的经济贝类.由于牡蛎营固着生活,其外部形态常随生活环境的不同而发生极大的变化.牡蛎形态上的这一特点,给主要依据形态特征和生态习性来鉴别物种的经典分类工作带来很大困难,同物异名和异物同名的现象时常发生.

  4. Bilaterian phylogeny based on analyses of a region of the sodium-potassium ATPase beta-subunit gene.

    Science.gov (United States)

    Anderson, Frank E; Córdoba, Alonso J; Thollesson, Mikael

    2004-03-01

    Molecular investigations of deep-level relationships within and among the animal phyla have been hampered by a lack of slowly evolving genes that are amenable to study by molecular systematists. To provide new data for use in deep-level metazoan phylogenetic studies, primers were developed to amplify a 1.3-kb region of the alpha subunit of the nuclear-encoded sodium-potassium ATPase gene from 31 bilaterians representing several phyla. Maximum parsimony, maximum likelihood, and Bayesian analyses of these sequences (combined with ATPase sequences for 23 taxa downloaded from GenBank) yield congruent trees that corroborate recent findings based on analyses of other data sets (e.g., the 18S ribosomal RNA gene). The ATPase-based trees support monophyly for several clades (including Lophotrochozoa, a form of Ecdysozoa, Vertebrata, Mollusca, Bivalvia, Gastropoda, Arachnida, Hexapoda, Coleoptera, and Diptera) but do not support monophyly for Deuterostomia, Arthropoda, or Nemertea. Parametric bootstrapping tests reject monophyly for Arthropoda and Nemertea but are unable to reject deuterostome monophyly. Overall, the sodium-potassium ATPase alpha-subunit gene appears to be useful for deep-level studies of metazoan phylogeny.

  5. Content of toxic and essential metals in canned mussels commonly consumed in Tenerife, Canary Islands, Spain.

    Science.gov (United States)

    Gutiérrez, Angel; Lozano, Gonzalo; Hardisson, Arturo; Rubio, Carmen; González, Tomás

    2004-07-01

    Concentrations of three toxic heavy metals (Hg, Pb, Cd) and six essential heavy metals (Fe, Zn, Mn, Cr, Cu, Ni) were determined in mussel conserves (Mytilus galloprovincialis, Bivalvia, Mollusca) consumed habitually by individuals in Tenerife (Canary Islands, Spain). A total of 600 samples were analyzed, corresponding to six different commercial brands and four different processing types: pickled sauce (mixture of olive oil, vinegar, red pepper, laurel, and salt), coquille St. Jacques sauce (coquille St. Jacques broth), nature (water and salt), and bionature (water, salt, and soluble vegetal fiber). Samples were collected weekly from markets in Santa Cruz de Tenerife during a 12-month period. All values for toxic metals were lower than the permitted maximum for human consumption as proscribed in European Community Directive 2001/22/CE (1,000 microg/kg wet weight for Pb and Cd) and European Community Decision 93/351/EEC (500 microg/kg wet weight for Hg). For the six essential heavy metals, mussels are a very good source, contributing high percentages of the recommended daily allowance.

  6. Life history and propagation of the endangered dromedary pearlymussel (Dromus dromas) (Bivalvia:Unionidae)

    Science.gov (United States)

    Jones, J.W.; Neves, R.J.; Ahlstedt, S.A.; Mair, R.A.

    2004-01-01

    The reproduction, demography, and propagation of the endangered dromedary pearlymussel (Dromus dromas) (Lea, 1834) were studied in the Clinch and Powell rivers, Tennessee. Viable populations of the dromedary pearlymussel now occur only in the Clinch and Powell rivers; the species has been extirpated from the remaining portions of its range in the Cumberland and Tennessee river drainages. Females are long-term winter brooders, and they are gravid from October to June. Glochidia are contained in conglutinates that are red to white and resemble freshwater leeches or flatworms. Conglutinates are 20 to 40 mm long and are released through the excurrent aperture. Estimates of fecundity based on 7 gravid females collected from the Clinch River were 55,110 to 253,050 glochidia/mussel. The ages of 66 valves of D. dromas were determined by thin-sectioning and ranged from 3 to 25 y. Annual growth averaged 5 mm/y until age 10 and decreased to ???1.2 mm/ y thereafter. Nineteen fish species were tested for suitability as hosts for glochidia. Ten were confirmed as hosts through induced infestations of glochidia: black sculpin (Cottus baileyi), greenside darter (Etheostoma blennioides), fantail darter (Etheostoma flabellare), snubnose darter (Etheostoma simoterum), tangerine darter (Percina aurantiaca), blotchside logperch (Percina burtoni), logperch (Percina caprodes), channel darter (Percina copelandi), gilt darter (Percina evides), and Roanoke darter (Percina roanoka). Juveniles produced from these hosts were cultured in dishes held in nonrecirculating aquaculture systems containing fine sediment (<105 ??m) and were fed the green alga Nannochloropsis oculata every 2 d. Survival of 2810 newly metamorphosed juveniles was 836 (29.7%) after 1 to 2 wk.

  7. Reestablecimiento de Choromytilus chorus (Molina, 1782) (Bivalvia: Mytilidae) en el norte de Chile

    OpenAIRE

    Avendaño,Miguel; Cantillánez,Marcela

    2011-01-01

    Hasta fines del siglo pasado no existían registros de la presencia de Choromytilus chorus al norte de los 23°S, pese a antecedentes que señalaban su existencia en épocas pasadas. Ciertos cambios relacionados con las masas de agua costeras de esta zona, habrían generado la ausencia o escasez que presentaba el entorno costero actual. Sin embargo, hace una década atrás, su presencia en el norte de Chile, comienza a tener connotación pesquera. En el presente trabajo se confirma su reestablecimien...

  8. Copepoda (Crustacea) associated with commercial and non-commercial Bivalvia in the East Scheldt, The Netherlands

    NARCIS (Netherlands)

    Stock, Jan H.

    1993-01-01

    Six species of Copepoda Poecilostomatoida of the families Myicolidae, Sabelliphilidae, Lichomolgidae, and Mytilicolidae are recorded from six different species of intertidal bivalves in the East Scheldt (The Netherlands), a branch of the southern bight of the North Sea. One bivalve species may harbo

  9. [Population dynamic of Donax denticulatus (Bivalvia: Donacidae) at Carenero Beach, Southeastern Cuba].

    Science.gov (United States)

    Ocaña, Frank A; Apín, Yanet C; Cala, Yuself R

    2013-12-01

    Bivalve molluscs of Donax genus are a very important component of macro-invertebrate assemblages of sandy beaches, and some species are of commercial value in different countries. Although in Cuba Donax denticulatus is not a currently exploited species, the information concerning a stock assessment is a basic step for future use of this resource. With the aim to generate new data on this species structure, growth and secondary production, monthly samples of D. denticulatus were taken from a beach of the Southeastern coast of Cuba, from February to December 2008. Samples were taken from four stations located along the beach; three strata were marked (P1, P2 and P3) per station across the intertidal zone. Three replicated samples of sediments were taken from each stratum with a 0.025 m2 PVC core and were posteriorly sieved with a 1 mm mesh. Histograms of shell length were constructed based on 1 mm intervals and growth parameters were estimated using ELEFAN I routine of FISAT. Mean density ranged from 146.67-855.55 ind./m2 and no differences were found among months (ANOVA, p > 0.05) but among strata (Scheffé, p < 0.05). An association of recruits, young and adults abundances with the strata (chi2, p < 0.01) was found. Most of the recruits were found in the upper strata while young and adult individuals were abundant in the mid-lower strata. Size frequency histograms of this population showed recruitment between March-June. Growth parameters estimated by Von Bertalanffy were Linfinity = 27.5 mm and K = 1.5/year; and the life spam was estimated in 1.5 years. Using the length-converted catch curve, the mortality rate (Z) was estimated in 4.97/year. Based in terms of Ash free dry mass (AFDM), mean biomass was estimated in 0.47 g/m2.year and the somatic production in 12.4 g/m2.year. The renewal rate (P/B) estimated for this population was 26.38, the highest among other Donax populations. High densities, fast growth and high somatic production indicate that this population can be exploited for fishing purposes for which some management measures are proposed.

  10. Description of a new species of Glycymeris (Bivalvia: Arcoidea) from Madeira, Selvagens and Canary Islands

    NARCIS (Netherlands)

    Goud, J.; Gulden, G.

    2009-01-01

    After revision of the Glycymerididae in the collection of the National Museum of Natural history, a new species, Glycymeris vanhengstumi is described here. It occurs off the coast of Madeira, the Selvagens and the Canary Islands.

  11. Molecular Cytogenetics in Trough Shells (Mactridae, Bivalvia: Divergent GC-Rich Heterochromatin Content

    Directory of Open Access Journals (Sweden)

    Daniel García-Souto

    2016-08-01

    Full Text Available The family Mactridae is composed of a diverse group of marine organisms, commonly known as trough shells or surf clams, which illustrate a global distribution. Although this family includes some of the most fished and cultured bivalve species, their chromosomes are poorly studied. In this work, we analyzed the chromosomes of Spisula solida, Spisula subtruncata and Mactra stultorum by means of fluorochrome staining, C-banding and fluorescent in situ hybridization using 28S ribosomal DNA (rDNA, 5S rDNA, H3 histone gene and telomeric probes. All three trough shells presented 2n = 38 chromosomes but different karyotype compositions. As happens in most bivalves, GC-rich regions were limited to the nucleolus organizing regions in Spisula solida. In contrast, many GC-rich heterochromatic bands were detected in both Spisula subtruncata and Mactra stultorum. Although the three trough shells presented single 5S rDNA and H3 histone gene clusters, their chromosomal locations differed. Regarding major rDNA clusters, while Spisula subtruncata presented a single cluster, both Spisula solida and Mactra stultorum showed two. No evidence of intercalary telomeric signals was detected in these species. The molecular cytogenetic characterization of these taxa will contribute to understanding the role played by chromosome changes in the evolution of trough shells.

  12. Lifespan, growth rate, and body size across latitude in marine Bivalvia, with implications for Phanerozoic evolution.

    Science.gov (United States)

    Moss, David K; Ivany, Linda C; Judd, Emily J; Cummings, Patrick W; Bearden, Claire E; Kim, Woo-Jun; Artruc, Emily G; Driscoll, Jeremy R

    2016-08-17

    Mean body size in marine animals has increased more than 100-fold since the Cambrian, a discovery that brings to attention the key life-history parameters of lifespan and growth rate that ultimately determine size. Variation in these parameters is not well understood on the planet today, much less in deep time. Here, we present a new global database of maximum reported lifespan and shell growth coupled with body size data for 1 148 populations of marine bivalves and show that (i) lifespan increases, and growth rate decreases, with latitude, both across the group as a whole and within well-sampled species, (ii) growth rate, and hence metabolic rate, correlates inversely with lifespan, and (iii) opposing trends in lifespan and growth combined with high variance obviate any demonstrable pattern in body size with latitude. Our observations suggest that the proposed increase in metabolic activity and demonstrated increase in body size of organisms over the Phanerozoic should be accompanied by a concomitant shift towards faster growth and/or shorter lifespan in marine bivalves. This prediction, testable from the fossil record, may help to explain one of the more fundamental patterns in the evolutionary and ecological history of animal life on this planet.

  13. Molecular Cytogenetics in Trough Shells (Mactridae, Bivalvia): Divergent GC-Rich Heterochromatin Content

    OpenAIRE

    Daniel García-Souto; Concepción Pérez-García; Jack Kendall; Pasantes, Juan J.

    2016-01-01

    The family Mactridae is composed of a diverse group of marine organisms, commonly known as trough shells or surf clams, which illustrate a global distribution. Although this family includes some of the most fished and cultured bivalve species, their chromosomes are poorly studied. In this work, we analyzed the chromosomes of Spisula solida, Spisula subtruncata and Mactra stultorum by means of fluorochrome staining, C-banding and fluorescent in situ hybridization using 28S ribosomal DNA (rDNA)...

  14. The complete mitogenome of the marine bivalve Lutraria rhynchaena Jonas 1844 (Heterodonta: Bivalvia: Mactridae).

    Science.gov (United States)

    Gan, Han Ming; Tan, Mun Hua; Thai, Binh Thanh; Austin, Christopher M

    2016-01-01

    The complete mitochondrial genome of the commercially important snout otter clam Lutraria rhynchaena was obtained from low-coverage shotgun sequencing data on the MiSeq platform. The L. rhynchaena mitogenome has 16,927 base pairs (69% A + T content) and made up of 12 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a 953 bp non-coding AT-rich region. This is the first mitogenome to be sequenced from the genus Lutraria, and the seventh to be reported for the family Mactridae.

  15. Oocyte Degeneration Associated with Follicle Cells in Female Mactra chinensis (Bivalvia: Mactridae).

    Science.gov (United States)

    Kim, Sung Han; Chung, Ee-Yung; Lee, Ki-Young

    2014-12-01

    Ultrastructural studies of oocyte degeneration in the oocyte, and the functions of follicle cells during oocyte degeneration are described to clarify the reproductive mechanism on oocyte degeneration of Mactra chinensis using cytological methods. Commonly, the follicle cells are attached to the oocyte. Follicle cells play an important role in oocyte degeneration. In particular, the functions of follicle cells during oocyte degeneration are associated with phagocytosis and the intracellular digestion of products. In this study, morphologically similar degenerated phagosomes (various lysosomes), which were observed in the degenerated oocytes, appeared in the follicle cells. After the spawning of the oocytes, the follicle cells were involved in oocyte degeneration through phagocytosis by phagolysosomes. Therefore, it can be assumed that follicle cells reabsorb phagosomes from degenerated oocytes. In this study, the presence of lipid granules, which occurred from degenerating yolk granules, gradually increased in degenerating oocytes. The function of follicle cells can accumulate reserves of lipid granules and glycogen in the cytoplasm, which can be employed by the vitellogenic oocyte. Based on observations of follicle cells attached to degenerating oocytes after spawning, the follicle cells of this species are involved in the lysosomal induction of oocyte degeneration for the reabsorption of phagosomes (phagolysosomes) in the cytoplasm for nutrient storage, as seen in other bivalves.

  16. Embryonic and larval development of Spisula solidissima similis (Say, 1822) (Bivalvia: Mactridae)

    OpenAIRE

    Walker, R.L.; O Beirn, F. X.

    1996-01-01

    Larvae of the southern surf clam, Spisula solidissima similis (Say, 1822), were reared in the laboratory at a salinity of 25 ppt and a temperature of 20-22°C through the embryonic and early larval development period. Unfertilized eggs averaged 58.5 ± 0.32 (SE) μm, with the size-frequency of eggs being normal. First polar body was observed 22 minutes after fertilization with 50% of eggs exhibiting polar bodies after 26 minutes. Ciliated blastula and trochophore stages occurred at 6 hours an...

  17. Effects of water temperature change on immune function in surf clams, Mactra veneriformis (Bivalvia: Mactridae).

    Science.gov (United States)

    Yu, Jin Ha; Song, Jae Hee; Choi, Min Chul; Park, Sung Woo

    2009-09-01

    Surf clam, Mactra veneriformis is one of the crucial fishery resources in Korea. This study was performed to examine the immune functions of the surf clam under the stress of water temperature changes at 10 degrees C, 20 degrees C or 30 degrees C for 24h. Viable bacterial counts (VBC), total haemocyte count (THC), phagocytic activity, lysozyme activity, NRR times and SOD activity were assessed in three different water temperature groups. Clams held at 10 degrees C decreased in THC, lysozyme activity and NRR times, but phagocytic activity was increased. The highest temperature (30 degrees C) significantly increased in THC, whereas it decreased in phagocytic activity, lysozyme activity and NRR times. In clams maintained at 20 degrees C, phagocytic activity, lysozyme activity and NRR times were increased whereas THC was somewhat decreased with respect to clams held at 30 degrees C. However, water temperature changes did not elicit any alteration of VBC and SOD activity. The present study demonstrates that acute water temperature change affects the haemocytic and haemolymphatic functions, reducing immunosurveillance in stressed surf clam, M. veneriformis.

  18. Oocyte Degeneration Associated with Follicle Cells in Female Mactra chinensis (Bivalvia: Mactridae)

    OpenAIRE

    Kim, Sung Han; Chung, Ee-Yung; Lee, Ki-Young

    2014-01-01

    Ultrastructural studies of oocyte degeneration in the oocyte, and the functions of follicle cells during oocyte degeneration are described to clarify the reproductive mechanism on oocyte degeneration of Mactra chinensis using cytological methods. Commonly, the follicle cells are attached to the oocyte. Follicle cells play an important role in oocyte degeneration. In particular, the functions of follicle cells during oocyte degeneration are associated with phagocytosis and the intracellular di...

  19. Molecular Cytogenetics in Trough Shells (Mactridae, Bivalvia): Divergent GC-Rich Heterochromatin Content.

    Science.gov (United States)

    García-Souto, Daniel; Pérez-García, Concepción; Kendall, Jack; Pasantes, Juan J

    2016-08-16

    The family Mactridae is composed of a diverse group of marine organisms, commonly known as trough shells or surf clams, which illustrate a global distribution. Although this family includes some of the most fished and cultured bivalve species, their chromosomes are poorly studied. In this work, we analyzed the chromosomes of Spisula solida, Spisula subtruncata and Mactra stultorum by means of fluorochrome staining, C-banding and fluorescent in situ hybridization using 28S ribosomal DNA (rDNA), 5S rDNA, H3 histone gene and telomeric probes. All three trough shells presented 2n = 38 chromosomes but different karyotype compositions. As happens in most bivalves, GC-rich regions were limited to the nucleolus organizing regions in Spisula solida. In contrast, many GC-rich heterochromatic bands were detected in both Spisula subtruncata and Mactra stultorum. Although the three trough shells presented single 5S rDNA and H3 histone gene clusters, their chromosomal locations differed. Regarding major rDNA clusters, while Spisula subtruncata presented a single cluster, both Spisula solida and Mactra stultorum showed two. No evidence of intercalary telomeric signals was detected in these species. The molecular cytogenetic characterization of these taxa will contribute to understanding the role played by chromosome changes in the evolution of trough shells.

  20. Isolation by distance and low connectivity in the peppery furrow shell Scrobicularia plana (Bivalvia)

    NARCIS (Netherlands)

    Santos, Silvia; Cruzeiro, Catarina; Olsen, Jeanine L.; van der Veer, Henk W.; Luttikhuizen, Pieternella C.

    2012-01-01

    Scrobicularia plana da Costa, 1778, a commercially important bivalve species in southern Europe, is commonly found along the NE Atlantic and Mediterranean coasts. Like other intertidal mollusk species, it has a wide distributional range and high potential for larval dispersal. However, S. plana has

  1. The biology and functional morphology of Macoma biota (Bivalvia: Tellinidae: Macominae

    Directory of Open Access Journals (Sweden)

    Pedro Ribeiro Piffer

    2011-06-01

    Full Text Available Macoma biota Arruda & Domaneschi, 2005, is a recently described species known only from the intertidal zone of Praia da Cidade, Caraguatatuba Bay, in the state of São Paulo, southeastern Brazil. The main purpose of the present paper is to describe the biology of M. biota, beginning with a detailed analysis of its anatomy and functional morphology and how these attributes are correlated with its habitat and life history. The morphology of the organs in the pallial cavity and their sorting devices indicate that this species has efficient mechanisms to process large amounts of particles that enter this cavity via the inhalant current. M. biota can rapidly select the material suitable for ingestion and direct the undesired excess to the rejection mantle tracts. These characteristics along with the siphon's behavior and the digestive tract configuration reveal that this species can be classified primarily as a deposit feeder, like other species of the genus; however, it can also behave as a suspension feeder, depending on the environmental conditions.

  2. The Complete Maternally and Paternally Inherited Mitochondrial Genomes of a Freshwater Mussel Potamilus alatus (Bivalvia: Unionidae)

    Science.gov (United States)

    Hua, Dan; Xu, Pao; Ma, Xue Y.; Jin, Wu; Yuan, Xin H.; Gu, Ruo B.

    2017-01-01

    Doubly uniparental inheritance (DUI) of mitochondrial DNA, found only in some bivalve families and characterized by the existence of gender-associated mtDNA lineages that are inherited through males (M-type) or females (F-type), is one of the very few exceptions to the general rule of strict maternal mtDNA inheritance in animals. M-type sequences are often undetected and hence still underrepresented in the GenBank, which hinders the progress of the understanding of the DUI phenomenon. We have sequenced and analyzed the complete M and F mitogenomes of a freshwater mussel, Potamilus alatus. The M-type was 493 bp longer (M = 16 560, F = 16 067 bp). Gene contents, order and the distribution of genes between L and H strands were typical for unionid mussels. Candidates for the two ORFan genes (forf and morf) were found in respective mitogenomes. Both mitogenomes had a very similar A+T bias: F = 61% and M = 62.2%. The M mitogenome-specific cox2 extension (144 bp) is much shorter than in other sequenced unionid mitogenomes (531–576 bp), which might be characteristic for the Potamilus genus. The overall topology of the phylogenetic tree is in very good agreement with the currently accepted phylogenetic relationships within the Unionidae: both studied sequences were placed within the Ambleminae subfamily clusters in the corresponding M and F clades. PMID:28068380

  3. Crecimiento del callo de hacha Atrina maura (Sowerby, 1835 (Bivalvia: Pinnidae cultivado a diferentes densidades

    Directory of Open Access Journals (Sweden)

    A. M. Góngora-Gómez

    2011-01-01

    Full Text Available Se estudió el crecimiento de Atrina maura cultivado a diferentes densidades durante 15 meses en la Isla Los Redos, Navolato, Sinaloa, México. El experimento se realizó utilizando el sistema de canastas en suspensión para los primeros cuatro meses de cultivo ajustando la densidad a 50, 100 y 200 organismos/canasta; y la siembra en parques de arena durante los once meses restantes, a una densidad de 4.5, 9 y 18 pinas/ m2 (50/canasta-4.5/m2, 100/canasta-9/m2 y 200/canasta-18/m2. Los juveniles (16.19 ± 6.66 mm de longitud total y 0.3 ± 0.16 g de peso total de promedio inicial se obtuvieron de un laboratorio comercial. Los parámetros físicos (oxígeno disuelto, salinidad, temperatura y pH y químicos (amonio total, nitritos, fosfatos y clorofila "a" fueron obtenidos cada 15 días y cada mes, respectivamente; mientras que 50 organismos seleccionados al azar de cada densidad, fueron medidos y pesados mensualmente. No se observaron diferencias significativas (P < 0.05 para la longitud y el peso entre las densidades en la etapa de canastas. Al final del cultivo, el grupo 200/canasta-18/m2 presentó el mayor peso promedio (284.26 ± 54.45 g. La supervivencia final fluctuó desde 28.15% para el grupo 50/canasta-4.5/m2, hasta 53.69% registrada para la mayor densidad (200/canasta- 18/m2. Los resultados indican que es posible sembrar A. maura a una densidad de 200/canasta-18/m2.

  4. Parasites of the mangrove mussel Mytella guyanensis (Bivalvia: Mytilidae) in Camamu Bay, Bahia, Brazil.

    Science.gov (United States)

    Ceuta, L O; Boehs, G

    2012-08-01

    This contribution reports the parasites found in the mangrove mussel Mytella guyanensis in Camamu Bay, Bahia, Brazil. Samples were collected monthly from September 2006 through October 2007. A total of 460 individuals were collected, fixed in Davidson's solution, and processed by standard histological techniques, and the sections were stained with Harris hematoxylin and eosin (H&E). The water temperature ranged from 23.5 to 31.6 ºC, and the salinity from 25 to 37‰. Microscopic analysis showed Rickettsia-like organisms (RLOs), Nematopsis sp. (Apicomplexa), and Platyhelminthes, including a turbellarian, sporocysts of Bucephalus sp., metacercariae, and metacestodes of Tylocephalum sp. Parasites were observed mainly in the gills, mantle, and digestive gland. The prevalence of Nematopsis sp. was 100%, and in heavily infected mussels the tissues of the labial palps were damaged. RLOs occurred in high prevalence and intensity of infection in some periods. The digenean sporocysts showed moderate prevalence but high intensity of infection, and caused parasitic castration. In general, there was no significant spatial or temporal variation (p > 0.05) of the parasites, which is probably attributable to the small variations of temperature and salinity in the region.

  5. Parasites of the mangrove mussel Mytella guyanensis (Bivalvia: Mytilidae in Camamu Bay, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    LO. Ceuta

    Full Text Available This contribution reports the parasites found in the mangrove mussel Mytella guyanensis in Camamu Bay, Bahia, Brazil. Samples were collected monthly from September 2006 through October 2007. A total of 460 individuals were collected, fixed in Davidson's solution, and processed by standard histological techniques, and the sections were stained with Harris hematoxylin and eosin (H&E. The water temperature ranged from 23.5 to 31.6 ºC, and the salinity from 25 to 37‰. Microscopic analysis showed Rickettsia-like organisms (RLOs, Nematopsis sp. (Apicomplexa, and Platyhelminthes, including a turbellarian, sporocysts of Bucephalus sp., metacercariae, and metacestodes of Tylocephalum sp. Parasites were observed mainly in the gills, mantle, and digestive gland. The prevalence of Nematopsis sp. was 100%, and in heavily infected mussels the tissues of the labial palps were damaged. RLOs occurred in high prevalence and intensity of infection in some periods. The digenean sporocysts showed moderate prevalence but high intensity of infection, and caused parasitic castration. In general, there was no significant spatial or temporal variation (p > 0.05 of the parasites, which is probably attributable to the small variations of temperature and salinity in the region.

  6. [Effect of probiotic bacteria on survival and growth of Cortez oyster larvae, Crassostrea corteziensis (Bivalvia: Ostreidae)].

    Science.gov (United States)

    Campa-Córdova, Angel Isidro; Luna-González, Antonio; Mazón-Suastegui, José Manuel; Aguirre-Guzmán, Gabriel; Ascencio, Felipe; González-Ocampo, Héctor Abelardo

    2011-03-01

    Disease control problems have major constraints in aquaculture production, and the use of probiotics in larviculture is a valid alternative to antibiotics. This study analyzed the effect of probiotic bacteria on survival and final size of Cortez oyster larvae Crassostrea corteziensis. Two different probiotic concentrations were evaluated, 1 x 10(4) and 1 x 10(5) CFU/ml of Lactic acid bacteria (strain NS61) isolated from Nodipecten subnodosus, and bacilli isolated from the white leg shrimp, Litopenaeus vannamei (Pseudomonas aeruginosa, strain YC58) and C. corteziensis (Burkholderia cepacia, strain Y021). Bacteria were added directly into culture tanks, starting the bioassays from veliger to pediveliger stages as follows: (1) Control, without probiotics; (2) lactic acid bacteria (Lb); (3) bacilli mix (Mb) in a proportion 1:1. Results showed a higher larval survival with Lb and Mb at a dose of 1 x 10(4) CFU/ml compared to the control group. Larvae exposed to Mb at 1 x 10(5) CFU/ml showed higher survival than Lb and control. Larval final size was not significantly increased with the tested probiotics, but larvae treated with Lb at 1 x 10(5) CFU/ml showed less survival rate than those treated at 1 x 10(4) CFU/ml. This study showed the beneficial effect of these probiotics, added individually or mixed in C. corteziensis larvae culture.

  7. [Reproductive cycle of the mangrove oyster Crassostrea rhizophorae (Bivalvia: Ostreidae) in Camamu Bay, Bahia, Brasil].

    Science.gov (United States)

    Lenz, Tiago; Boehs, Guisla

    2011-03-01

    The mangrove oyster Crassostrea rhizophorae is important fishery resource along the entire Brasilian coast with excellent potential for marine culture. The purpose of this paper was to examine the reproductive characteristics of the oyster of the Maraú river estuary in Camamu Bay, Bahia, Brasil. The samples were collected monthly, from September 2006 to August 2007, at two points (I and II) in Camamu Bay. At each site 20 oysters were collected for histological analysis, fixed in Davidson's solution, embedded in paraffin, dehydrated in an ethanol series, sectioned (7 microm thick) and stained with Harris hematoxylin and Eosin (HE). Additionally, 30 oysters were sampled, at each point, for a condition index analysis. The water temperature ranged from 23.5 degrees C to 30 degrees C and the salinity from 15 to 25 ups at Point I (Maraú) and from 25 to 35 at Point II (Tanque Island). The oyster's height ranged from 30 to 92 mm at Point I and from 27 to 102 mm at Point II, with an average of 49.0 mm +/- 9.1 (n = 230) and 49.9 mm +/- 9.9 (n = 237), respectively. Among the sampled oysters at Point I, 59.1% were females, 31.3% males, 1.3% hermaphrodites and 8.2% of the oysters of undetermined sex. At Point II, 66.2% were females, 30.4% males, 0.8% hermaphrodites and 2.5% (n = 237) of undetermined sex. The gonadic stage analysis indicated that the reproduction period of the C. rhizophorae in the Maraú Peninsula was continuous all year, without any regressive phase. The condition index (R) ranged from 8.0% to 17.7%. The peak periods of R coincided with the expressive oyster's percentage in the maturation and liberation gametic stages. The results of these findings will contribute information for the oyster spat collection and to the process installation of the oyster culture in Camamu Bay.

  8. Vertical transmission of chemoautotrophic symbionts in the bivalve Solemya velum (Bivalvia: Protobranchia).

    Science.gov (United States)

    Krueger, D M; Gustafson, R G; Cavanaugh, C M

    1996-04-01

    Adults of the bivalve species Solemya velum live in symbiosis with chemoautotrophic bacteria in specialized gill bacteriocytes. The bacteria play an essential nutritional role in the mature association, fixing CO2 via the Calvin cycle with energy obtained through the oxidation of reduced sulfur compounds. To understand how the continuity of this partnership is maintained between host generations, we investigated the mode of symbiont transfer in S. velum. A diagnostic assay using the polymerase chain reaction and primers specific for the S. velum symbiont ribulose-1,5-bisphosphate carboxylase (RubisCO) gene consistently detected bacterial sequence in female gonad tissue, suggesting the presence of symbiont cells in host ovaries and a vertical mode of symbiont transmission from mother to offspring. Furthermore, intracellular bacteria were present in the developing gills of juveniles that had not yet hatched from the gelatinous capsule in which larval development occurs (11 days after fertilization). By 64 days postfertilization, the typical adult gill ultrastructure of alternating bacteriocytes and symbiont-free-intercalary cells was apparent. Knowledge about the mode of symbiont transfer in S. velum allows further study into the dynamics of host-symbiont interactions in chemoautotrophic associations.

  9. Growth and production of Donax striatus(Bivalvia: Donacidae from Las Balsas beach, Gibara, Cuba

    Directory of Open Access Journals (Sweden)

    Frank A Ocaña

    2015-09-01

    Full Text Available Abstract:Clams of the genus Donaxare worldwide the dominating group of the invertebrate community on sandy beaches. They are primary consumers that provide a significant abundance and biomass to the ecosystem. In the Caribbean, Donax striatushas an important role for nature and human, nonetheless studies on the population dynamics of this beach clam are scarce and no information exists on secondary production of this species. Growth parameters and secondary production of D. striatuswere estimated from February 2008 to November 2009 at Las Balsas beach, Northeastern Cuba, in order to provide basic information for management purposes. In each month 45 samples were taken by means of a PVC corer of 0.025 m2 area and sieved with a 1 mm mesh. Animals were measured and weighted with and without shell. A total of 5 471 specimens were collected during the sampling period. Shell length ranged from 2.7-33.3 mm. Growth parameters estimated from length frequency data were Lm = 36.1 mm, K= 0.8/yr and t0 = 0.2/yr. The growth performance resulted in values of 0'= 3.02. Life span was 2.4 yrs and mortality rate was 3.07 /yr. In 2008, mean abundance of D. striatusranged between 17.1770.7 ind./m2. In 2009 the lowest mean abundance was 34.4 and the highest was 892.5 ind./m2. During 2009 biomass and production was more than twice higher in comparison with 2008. Individual production showed highest values in the 24 mm shell size (3.74 g/m2.yr and 25 mm (0.71 g/m2.yr, considering mass with shell and without shell, respectively. During 2009 abundance of individuals with 15 mm shell length or more increased resulting in higher biomass and production, compared to 2008. Using the conversion factor of wet mass to ash free dry mass (AFDM, annual production ranged between 2.87-6.11 g AFDM/m2.yr, resulting in a turnover rate (P/B between 5.11 and 3.47 in 2008 and 2009, respectively. The rapid growth and high turnover rate of D. striatussuggest a rapid recovery of the population. These results support the idea that this beach clam is an important resource at Las Balsas beach. Thus its exploitation must continue with caution, and only at the level of a recreational fishery.

  10. Habitat Preferences and Growth of Ruditapes bruguieri (Bivalvia: Veneridae at the Northern Boundary of Its Range

    Directory of Open Access Journals (Sweden)

    Alla V. Silina

    2014-01-01

    Full Text Available This work is the first attempt to study growth and some morphological parameters of the clam Ruditapes bruguieri, as well as its habitat preferences. It is found that R. bruguieri lives on bottom sediments including pebble and coarse- and medium-grained sand with a slight admixture of silt. At the study area, this bivalve inhabits sea waters with good aeration, stable oceanic water salinity, and a high oxygen concentration. The annual fluctuations of the water temperature from 13-14°C (in winter to 22–29°C (in summer are close to the threshold temperature values, within which the species can exist. Near the boundary of the species range, along the Jeju Island coasts, south of Republic of Korea, 83.8% of all clams die during the coldest period of the year. Here, annual rings are formed on R. bruguieri shells during winter. The maximum age of R. bruguieri, determined during the study, is 6.5 years, but the clam samples contain mainly individuals at 3.0–3.5 years of age (34%. The largest clam dimensions are 36.0 × 26.5 mm (length × height of shell. At the study area, a usual shell length is 20.0–32.0 mm (75% of all the collected individuals.

  11. Life on wood - the carnivorous deep-sea mussel Idas argenteus (Bathymodiolinae, Mytilidae, Bivalvia

    DEFF Research Database (Denmark)

    Ockelmann, Kurt W.; Dinesen, Grete E.

    2011-01-01

    of suspension-feeding mytilids, with no abfrontal tissue adaptation for symbiotic chemo-autotrophic bacteria. The adaptations in I. argenteus to capture prey as well as the reproductive pattern of the prey, Xyloredo, and its functional dwarf males are described. The population dynamics and adaptation...

  12. Molecular phylogenetics and historical biogeography amid shifting continents in the cockles and giant clams (Bivalvia: Cardiidae).

    Science.gov (United States)

    Herrera, Nathanael D; Ter Poorten, Jan Johan; Bieler, Rüdiger; Mikkelsen, Paula M; Strong, Ellen E; Jablonski, David; Steppan, Scott J

    2015-12-01

    Reconstructing historical biogeography of the marine realm is complicated by indistinct barriers and, over deeper time scales, a dynamic landscape shaped by plate tectonics. Here we present the most extensive examination of model-based historical biogeography among marine invertebrates to date. We conducted the largest phylogenetic and molecular clock analyses to date for the bivalve family Cardiidae (cockles and giant clams) with three unlinked loci for 110 species representing 37 of the 50 genera. Ancestral ranges were reconstructed using the dispersal-extinction-cladogenesis (DEC) method with a time-stratified paleogeographic model wherein dispersal rates varied with shifting tectonics. Results were compared to previous classifications and the extensive paleontological record. Six of the eight prior subfamily groupings were found to be para- or polyphyletic. Cardiidae originated and subsequently diversified in the tropical Indo-Pacific starting in the Late Triassic. Eastern Atlantic species were mainly derived from the tropical Indo-Mediterranean region via the Tethys Sea. In contrast, the western Atlantic fauna was derived from Indo-Pacific clades. Our phylogenetic results demonstrated greater concordance with geography than did previous phylogenies based on morphology. Time-stratifying the DEC reconstruction improved the fit and was highly consistent with paleo-ocean currents and paleogeography. Lastly, combining molecular phylogenetics with a rich and well-documented fossil record allowed us to test the accuracy and precision of biogeographic range reconstructions.

  13. Age and growth in three populations of Dosinia exoleta (Bivalvia: Veneridae) from the Portuguese coast

    Science.gov (United States)

    Moura, Paula; Vasconcelos, Paulo; Gaspar, Miguel B.

    2013-12-01

    The present study aimed at estimating the age and growth in three populations of Dosinia exoleta from the Portuguese coast (Aveiro in the north, Setúbal in the southwest and Faro in the south). Two techniques were compared to ascertain the most suitable method for ageing D. exoleta. Growth marks on the shell surface and acetate peel replicas of sectioned shells were the techniques applied. Two hypotheses were tested: growth parameters present latitudinal variation along the Portuguese coast; growth parameters are influenced by the fishing exploitation. Shell surface rings proved inappropriate for ageing this species, whereas acetate peels provided realistic estimates of the von Bertalanffy growth parameters ( K, L ∞ and t 0). A latitudinal gradient in growth rate was detected, with a clear southward increase in the growth coefficient ( K) of D. exoleta (Faro > Setúbal and Aveiro) indicating that warmer waters in southern Portugal provide optimal conditions for the growth of this species. Fishing exploitation in northern Portugal targets larger individuals and leaves behind a younger population of smaller individuals, decreasing the asymptotic shell length ( L ∞ ) of D. exoleta from Aveiro. The overall growth performance was compared among populations of D. exoleta and with other venerid species worldwide.

  14. Molecular insights into the taxonomy of Hypanis (Bivalvia, Cardiidae, Lymnocardiinae) in the Black Sea lagoons

    Science.gov (United States)

    Popa, Luis; Popa, Oana; Iorgu, Elena; Kelemen, Beatrice; Murariu, Dumitru

    2012-06-01

    In this study, we used data from morphology and three DNA markers to assess the taxonomic status of the putative bivalve species Hypanis colorata and Hypanis angusticostata in a Black Sea lagoon, the Razelm Lake in Romania. The morphological data (the shape of shell ribs and the multivariate analysis of morphometric variance of three variables constructed as the ratios between the main dimensions of the shell) confirmed that the two analyzed species are distinct morphological entities. Three molecular markers, one from the nuclear genome (18S rRNA) and two from the mitochondrial genome (16S rRNA and COI), showed extremely reduced sequence divergence (0-0.1%) between the two putative species. Based on these results, we suggest that H. angusticostata and H. colorata are morphotypes of a single species.

  15. Intraspecific phylogeography of Lasmigona subviridis (Bivalvia: Unionidae): Conservation implications of range discontinuity

    Science.gov (United States)

    King, T.L.; Eackles, M.S.; Gjetvaj, B.; Hoeh, W.R.

    1999-01-01

    A nucleotide sequence analysis of the first internal transcribed spacer region (ITS-1) between the 5.8S and 18S ribosomal DNA genes (640 bp) and cytochrome c oxidase subunit I (COI) of mitochondrial DNA (mtDNA) (576 bp) was conducted for the freshwater bivalve Lasmigona subviridis and three congeners to determine the utility of these regions in identifying phylogeographic and phylogenetic structure. Sequence analysis of the ITS-1 region indicated a zone of discontinuity in the genetic population structure between a group of L. subviridis populations inhabiting the Susquehanna and Potomac Rivers and more southern populations. Moreover, haplotype patterns resulting from variation in the COI region suggested an absence of gene exchange between tributaries within two different river drainages, as well as between adjacent rivers systems. The authors recommend that the northern and southern populations, which are reproductively isolated and constitute evolutionarily significant lineages, be managed as separate conservation units. Results from the COI region suggest that, in some cases, unionid relocations should be avoided between tributaries of the same drainage because these populations may have been reproductively isolated for thousands of generations. Therefore, unionid bivalves distributed among discontinuous habitats (e.g. Atlantic slope drainages) potentially should be considered evolutionarily distinct. The DNA sequence divergences observed in the nuclear and mtDNA regions among the Lasmigona species were congruent, although the level of divergence in the COI region was up to three times greater. The genus Lasmigona, as represented by the four species surveyed in this study, may not be monophyletic.

  16. Reproductive ecology of Actinonaias ligamentina (Bivalvia:Unionidae) in a regulated river

    Science.gov (United States)

    Moles, K.R.; Layzer, J.B.

    2008-01-01

    Factors affecting the reproductive success of freshwater mussels in lotic systems are poorly understood. Gravidity, fecundity, and fertilization success of Actinonaias ligamentina were examined at 4 sites along a 63-km reach of the Green River immediately below the Green River Dam, Kentucky. No gravid females were collected at the site closest to the dam, and the percentage of gravid females at downstream sites ranged from 20 to 36%. Not all females became gravid, despite the presence of early stages of ova in the gonadal fluid. This observation suggests that female A. ligamentina undergo a resting stage and, therefore, might not become gravid every year. Fecundity differed among sites and increased with distance from the dam. Fertilization rates ranged from 32 to 97% among sites and increased with distance from the dam. Fertilization rate was independent of local mussel density and position in the mussel bed. The high fertilization rates observed in the upstream portions of mussel beds indicate that freshwater mussel sperm have the ability to travel to distant females in lotic systems. Therefore, females are not necessarily dependent upon nearby males for fertilization. Successful fertilization of A. ligamentina at low mussel densities in the Green River suggests that natural recovery of rare endangered species might be possible if host fish and suitable conditions for juvenile survival and growth are present. ?? 2008 by The North American Benthological Society.

  17. Diversity of Edible Mollusc (Gastropoda and Bivalvia at Selected Divison of Sarawak, Malaysia

    Directory of Open Access Journals (Sweden)

    Hadi Hamli

    2012-01-01

    Full Text Available Diversity of edible mollusc was studied at eight divisions of Sarawak from August 2010 to May 2011. At each division, diversity and number of species were collected from road site selling out lets and local wet markets. Total number of mollusc was comprised of 29 species namely  Solen regularies, S. lamarckii,  Pharella acutidens, Anadara granosa, Pholas orientalis, Gluconome virens, Circe scripta, Anodonta woodina, Paphia undulata, Amusium pleuronectes, Meretrix meretrix, M. lyrata, Polymesoda bengalensis, P. erosa and P. expansa  for bivalve and  Cerithidea rizophorarum, C. obtusa, Telescopium telescopium, Clithon retropictus, Nerita articulate, N. chamaeleon, N. albicilla, Ellobium aurisjuda, Trochus radiates, Planaxis sulcatus, Monodonta labio, Turbo crasus, Thais aculate  and Melo melo  for gastropod. The species number of bivalve was recorded highest (15 species in mollusc group from Sarawak. Mollusc diversity was found highest (14 species in Bintulu and lowest (1 species in the division of Sarikei. From this study, there is a wide chance of research to further explore both on the possibility of commercial value and ecosystem conservation.

  18. Biochemical changes in relation to the breeding cycles of Nausitora hedleyi Schepman (Bivalvia: Teredinidae)

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswathy, M.; Nair, N.B.

    The biochemical changes in relation to the breeding cycles of Nausitora hedleyi - a typical estuarine boring bivalve were studied. The systematic variations in the annual reproductive cycle were also determined. Samples were collected from Cochin...

  19. Effects of stocking density on intermediate culture of the razor clam Ensis arcuatus (Pharidae: Bivalvia)

    OpenAIRE

    Da Costa Gonzalez, Fiz; Barreiro, Berta; Ojea, Justa; Novoa, Susana; Martinez-patino, Dorotea

    2015-01-01

    Commercial production of most bivalve species involves a phase of intermediate cultivation during which juveniles are grown under protected conditions until they can be transferred to the final grow-out location. Consequently, the aim of this study was investigating the effect of density on growth and survival in the intermediate culture of the razor clam Ensis arcuatus in raft. Two series of experiments were performed, using in the first experiment two holding systems: 5-L plastic bottles an...

  20. Complete mitochondrial genome of the Asian green mussel Perna viridis (Bivalvia, Mytilidae).

    Science.gov (United States)

    Li, Xiaoling; Wu, Xiangyun; Yu, Ziniu

    2012-10-01

    The complete mitochondrial (mt) genome of the Asian green mussel Perna viridis (16,627 bp), an economically important bivalve, was newly sequenced and annotated. P. viridis is the shortest and has a comparatively highest overall A+T content (68%) among six available genomes of marine mussels to date. The atp8 gene's length (49 a.a.) of the green mussel is unexpectedly greatly shorter than that of other marine mussels (87 a.a.). Comparison of the gene order demonstrated that the six marine mussels share no identical gene blocks although they belong to the same family, which indicates that this group should be a good model to study mtDNA evolution and mitochondria inheritance.

  1. [Metallothioneins in Perna viridis (Bivalvia: Mytilidae): seasonal variation and its relation to reproductive biology].

    Science.gov (United States)

    Lemus, Mairin; Rojas, Nilis; Rojas-Astudillo, Luisa; Chung, Kyung

    2013-06-01

    Metallothionein is a cytosolic protein found in a variety of tissues and have been involved in the regulation of essential trace metals such as copper and zinc, and in the detoxification of essential and nonessential metals. With the aim to study their seasonal variation and their possible role in reproductive behavior, we evaluated metallothioneins (Mts) in Perna viridis, taken from Rio Caribe and Chacopata localities in the North coast of Sucre state, Venezuela. A total of 325 samples were obtained from February to December 2003. We determined the following biometric indices in bivalves: Condition Index (CI), meat yield (RC) and dry weight-length relationship (PSL). Besides, Mts in whole tissue were separated by molecular exclusion chromatography, Sephadex G-50 and quantified by saturation with cadmium. Our results showed that the biometric indices (RC and PSL) had seasonal variations between localities and maturity stages, with the exception of IC. No significant differences were found between sexes. Mts showed seasonal variations between localities, with the highest concentrations between February and March, and minimum ones between September and December, coinciding with the respectively high and low productivity periods in the area. The mussels from Rio Caribe had higher Mts concentration than those from Chacopata. Furthermore, immature mussels showed the highest Mts concentration while the lowest was found in spawned specimens. We found a significant negative relationship between Mts and CI. Our results demonstrated that MTs in Perna viridis are influenced by the condition index and reproductive status, as well as physico-chemical factors in the marine environment.

  2. Pollution monitoring in Southeast Asia using biomarkers in the mytilid mussel Perna viridis (Mytilidae: Bivalvia).

    Science.gov (United States)

    Nicholson, S; Lam, P K S

    2005-01-01

    Mytilid mussels have been extensively used in marine pollution monitoring programmes in temperate regions of the world although widespread subtropical representatives such as Perna viridis have only comparatively recently been utilised to monitor the sublethal effects of pollution in Southeast Asia. P. viridis is considered a subtropical equivalent of the temperate Mytilus sp. and has considerable potential for pollution monitoring throughout its geographical range. This paper reviews the current status of biomarkers in P. viridis and provides some recommendations on biological-effects monitoring to facilitate the assessment of coastal pollution in Southeast Asia.

  3. Physiological effects of hypercapnia in the deep-sea bivalve Acesta excavata (Fabricius, 1779) (Bivalvia; Limidae)

    DEFF Research Database (Denmark)

    Hammer, Karen M.; Kristiansen, Erlend; Zachariassen, Karl Erik

    2011-01-01

    The option of storing CO(2) in subsea rock formations to mitigate future increases in atmospheric CO(2) may induce problems for animals in the deep sea. In the present study the deep-sea bivalve Acesta excavata was subjected to environmental hypercapnia (pHSW 6.35, P(CO2), =33,000 mu atm) corresp......The option of storing CO(2) in subsea rock formations to mitigate future increases in atmospheric CO(2) may induce problems for animals in the deep sea. In the present study the deep-sea bivalve Acesta excavata was subjected to environmental hypercapnia (pHSW 6.35, P(CO2), =33,000 mu atm......) corresponding to conditions reported from natural CO(2) seeps. Effects on acid base status and metabolic rate were related to time of exposure and subsequent recovery. During exposure there was an uncompensated drop in both hemolymph and intracellular pH. Intracellular pH returned to control values, while...... extracellular pH remained significantly lower during recovery. Intracellular non-bicarbonate buffering capacity of the posterior adductor muscle of hypercapnic animals was significantly lower than control values, but this was not the case for the remaining tissues analyzed. Oxygen consumption initially dropped...

  4. Convergent and parallel evolution in life habit of the scallops (Bivalvia: Pectinidae).

    Science.gov (United States)

    Alejandrino, Alvin; Puslednik, Louise; Serb, Jeanne M

    2011-06-14

    We employed a phylogenetic framework to identify patterns of life habit evolution in the marine bivalve family Pectinidae. Specifically, we examined the number of independent origins of each life habit and distinguished between convergent and parallel trajectories of life habit evolution using ancestral state estimation. We also investigated whether ancestral character states influence the frequency or type of evolutionary trajectories. We determined that temporary attachment to substrata by byssal threads is the most likely ancestral condition for the Pectinidae, with subsequent transitions to the five remaining habit types. Nearly all transitions between life habit classes were repeated in our phylogeny and the majority of these transitions were the result of parallel evolution from byssate ancestors. Convergent evolution also occurred within the Pectinidae and produced two additional gliding clades and two recessing lineages. Furthermore, our analysis indicates that byssal attaching gave rise to significantly more of the transitions than any other life habit and that the cementing and nestling classes are only represented as evolutionary outcomes in our phylogeny, never as progenitor states. Collectively, our results illustrate that both convergence and parallelism generated repeated life habit states in the scallops. Bias in the types of habit transitions observed may indicate constraints due to physical or ontogenetic limitations of particular phenotypes.

  5. ESTRUCTURA POBLACIONAL DE DONAX STRIATUS (BIVALVIA, DONACIDAE EN PLAYA LAS BALSAS, GIBARA, CUBA

    Directory of Open Access Journals (Sweden)

    Frank A. Ocaña Borrego

    2011-06-01

    Full Text Available Donax striatus Linné 1767 es una de las dos especies de almejas de playa que se encuentra en el Caribe. Pocas investigaciones se han centrado en describir aspectos sobre la estructura poblacional de esta especie. Una población de D. striatus fue muestreada mensualmente desde febrero del 2008 hasta enero del 2009 en playa Las Balsas, Gibara, Cuba. La población mostró fluctuaciones estacionales de la densidad, presentando los mayores valores en los meses de mayo y octubre del 2008 y enero del 2009. Se encontraron tres picos de reclutamiento: abril-mayo, agosto del 2008 y enero del 2009. Se observó una distribución estratificada por grupos de tallas: los reclutas fueron registrados en los estratos superiores de la playa y los adultos, fundamentalmente, en los estratos bajos. La mayor abundancia se localizó en el estrato intermedio. No hubo correlación entre los cambios mensuales de densidad con las temperaturas, ni con las precipitaciones, sin embargo, parece que los cambios en el régimen habitual del oleaje y la elevación del nivel medio del mar tienen influencia sobre el comportamiento de la abundancia de esta especie. Se propone una hipótesis que combina parámetros morfodinámicos para explicar la distribución vertical de los diferentes componentes de la población. Donax striatus Linné 1767 is one of the two beach clam species that inhabits in the Caribbean. Few investigations have focused on describing aspects related with the population structure of this species. A population of D. striatus was surveyed from February 2008 to January 2009 in Las Balsas beach, Gibara, Cuba. The population showed seasonal fluctuations of the density presenting the higher values on May and October 2008 and January 2009. There were peaks of recruitment: April-May, August 2008 and January 2009. A stratified distribution by size classes was observed: recruits were found in the higher strata of the beach while adults occur mainly in the lowest strata. The higher abundance was found in the middle strata. There was no correlation between monthly changes in density and temperatures, nor with the rainfall however, changes in the normal wave’s regimen and mid sea level rise seems to have some influence over the behaviour of this species abundance. A hypothesis that combines morphodynamics parameters to explain the across shore distribution of the components of the population, is proposed.

  6. Characteristics of a refuge for native freshwater mussels (Bivalvia: Unionidae) in Lake St. Clair

    Science.gov (United States)

    McGoldrick, D.J.; Metcalfe-Smith, J. L.; Arts, M.T.; Schloesser, D.W.; Newton, T.J.; Mackie, G.L.; Monroe, E.M.; Biberhofer, J.; Johnson, K.

    2009-01-01

    The Lake St. Clair delta (??? 100??km2) provides an important refuge for native freshwater mussels (Unionidae) wherein 22 of the ??? 35 historical species co-occur with invasive dreissenids. A total of 1875 live unionids representing 22 species were found during snorkeling surveys of 32 shallow (??? 1??m) sites throughout the delta. Richness and density of unionids and zebra mussel infestation rates varied among sites from 3 to 13 unionid species, 0.02 to 0.12 unionids/m2, and < 1 to 35 zebra mussels/unionid, respectively. Zebra mussel infestation of unionids in the delta appears to be mitigated by dominant offshore currents, which limit densities of zebra mussel veligers in nearshore compared to offshore waters (13,600 vs. 28,000/m3, respectively). Glycogen concentrations in the tissues of a common and widespread species in the delta (Lampsilis siliquoidea) suggest that zebra mussels may be adversely affecting physiological condition of unionids in a portion of the Lake St. Clair delta. Physiological condition and community structure of unionids within the delta may also be influenced by differences in food quantity and quality resulting from the uneven distribution of water flowing from the St. Clair River. The delta likely supports the largest living unionid community in the lower Great Lakes and includes several species that have been listed as Endangered or Threatened in Canada and/or the state of Michigan, making it an important refuge for the conservation of native unionids. Crown Copyright ?? 2009.

  7. Troponin-like regulation in muscle thin filaments of the mussel Crenomytilus grayanus (Bivalvia: Mytiloida).

    Science.gov (United States)

    Vyatchin, Ilya G; Shevchenko, Ulyana V; Lazarev, Stanislav S; Matusovsky, Oleg S; Shelud'ko, Nikolay S

    2015-10-01

    Muscles of bivalve molluscs have double calcium regulation--myosin-linked and actin-linked. While the mechanism of myosin-linked regulation is sufficiently studied, there is still no consensus on the mechanism of actin-linked regulation. Earlier we showed a high degree of Ca2+-sensitivity of thin filaments from the adductor muscle of the mussel Crenomytilus grayanus (Mytiloida). In order to elucidate the nature of this regulation, we isolated the fraction of minor proteins from the mussel thin filaments, which confers Ca2+-sensitivity to reconstituted actomyosin-tropomyosin. Proteins of this fraction, ABP-19, ABP-20, and ABP-28, were chromatographically purified and identified. According to the results of mass spectrometry and Western blot analysis, as well as by their functional properties, these mussel actin-binding proteins appeared to correspond to the troponin components from the skeletal muscles of vertebrates (TnC, TnI and TnT). The reconstituted mussel troponin complex confers to actomyosin-tropomyosin more than 80% Ca2+-sensitivity. The in vivo molar ratio of actin/tropomyosin/troponin was calculated to be 7:1:0.5, i.e., the content of troponin in mussel thin filaments is two times lower than in thin filaments of skeletal muscles of vertebrates. These data demonstrate that troponin-like regulation found in the catch muscle of the mussel C. grayanus is present at least in two suborders of bivalves: Pectinoida and Mytiloida.

  8. Sperm structure and sperm transfer in Pseudopythina subsinuata (Bivalvia, Galeommatoidea)

    DEFF Research Database (Denmark)

    Jespersen, Åse

    2009-01-01

    -thick paraspermatozoa have a terminally placed irregularly cork-screw-shaped acrosome and a bundle of ca. 16 flagella emerging from behind the nucleus. The role of the paraspermatozoa is obscure. Euspermatozoa are transferred to the seminal receptacles of the females and attach with the tip of the acrosome...... the gill tissue to swell around the stem and some of the nearest filaments to coalesce. All branches are densely coated with euspermatozoa that are attached by means of their acrosomes. It is conjectured that the syncytial and multinucleate trees arise from seminal receptacle cells that detach from...... the receptacle and thereupon fuse. A similar process is known in the allied P. tsurumaru, but the resulting structure ("sperm-carrying body") is not attached to the gills....

  9. Direct evidence for maternal inheritance of bacterial symbionts in small deep-sea clams (Bivalvia: Vesicomyidae)

    Science.gov (United States)

    Szafranski, Kamil M.; Gaudron, Sylvie M.; Duperron, Sébastien

    2014-05-01

    Bacterial symbiont transmission is a key step in the renewal of the symbiotic interaction at each host generation, and different modes of transmission can be distinguished. Vesicomyidae are chemosynthetic bivalves from reducing habitats that rely on symbiosis with sulfur-oxidizing bacteria, in which two studies suggesting vertical transmission of symbionts have been published, both limited by the imaging techniques used. Using fluorescence in situ hybridization and transmission electron microscopy, we demonstrate that bacterial symbionts of Isorropodon bigoti, a gonochoristic Vesicomyidae from the Guiness cold seep site, occur intracellularly within female gametes at all stages of gametogenesis from germ cells to mature oocytes and in early postlarval stage. Symbionts are completely absent from the male gonad and gametes. This study confirms the transovarial transmission of symbionts in Vesicomyidae and extends it to the smaller species for which no data were previously available.

  10. Survival of male and female Cerastoderma glaucum (Bivalvia) during aerial exposure

    OpenAIRE

    Tarnowska, Katarzyna; Verney, A.; Wolowicz, Maciej; Féral, Jean-Pierre; Chenuil, Anne

    2012-01-01

    International audience; The lagoon cockle, Cerastoderma glaucum (Poiret, 1789) usually inhabits small, often isolated, water basins. Dispersal among these basins can take place overland (human mediated) or by migratory birds, when cockles are attached to their bodies. It requires the capacity of the cockle to survive aerial exposure. The time of survival of cockles in air was tested. The LT50 was of 80 h at 15 °C and 43 h at 22 °C. There was no significant difference in survival time neither ...

  11. Winter distribution, density and size of Mesodesma mactroides (Bivalvia, Mactracea in Monte Hermoso beach (Argentina

    Directory of Open Access Journals (Sweden)

    Sandra Marcela Fiori

    2004-03-01

    Full Text Available The yellow clam Mesodesma mactroides (Deshayes, 1854 is a seasonal migrant that moves in spring to the sandy upper intertidal level. In this paper we analyze the spatial distribution of density and mean shell size of the yellow clam population in Monte Hermoso beach (Argentina in winter 1995, i.e., three months before the mass mortality occurred in November 1995. Sampling covered 32 km of beach, with a regular design of 22 transects. The major environmental gradient in the beach was determined using principal component analysis (PCA on the correlation matrix of the environmental data (beach morphology, slope, and sand granulometry. Correlation analysis was used to assess the relationship between the score of a site (transect on the first and second principal component, and clam mean density and mean shell size. Most of the beach seems to be habitable for clams, their spatial heterogeneity not having been explained by the measured variables since, although the first axis of the PCA has demonstrated an E-W physical gradient, clam density was not in correlation with it. Density was maximum near the piers, even though these are points with high tourist activity. It seems that non-extractive touristic activities do not affect population density but rather mean shell size, probably due to reduction of growth rates. The abundance of the winter population, as compared with the assessment done after the mass mortality of November, strongly suggests that a great part of the population was overwintering in the intertidal fringe.O molusco Mesodesma mactroides (Deshayes, 1854 é uma espécie migrante sazonal que na primavera move-se para o nível entremarés superior da praia. Neste estudo, analisamos a distribuição espacial da densidade e o tamanho médio da população do bivalve na praia de Monte Hermoso (Argentina no inverno de 1995, i. é, três meses antes da mortalidade massiva desses moluscos, acontecida em novembro de 1995. A amostragem cobriu 32 km da praia, utilizando-se 22 transectos distribuídos regularmente. O gradiente ambiental principal na praia foi determinado mediante Análise de Componentes Principais (ACP a partir da matriz de correlação dos dados ambientais (morfologia e declividade da praia, e granulometria da areia. A análise da correlação foi utilizada para avaliar a relação entre o escore de um local (transecto no primeiro e segundo componentes principais, a densidade média dos moluscos e tamanho médio da concha. A maior parte da praia parece ser um habitat apropriado para esses moluscos e sua heterogeneidade espacial não foi explicada pelas variáveis medidas, uma vez que, embora o primeiro eixo da PCA tenha demonstrado um gradiente físico no sentido L-O, a densidade dos moluscos não apresentou correlação com o mesmo. A densidade apresentou o máximo valor próximo aos molhes, pontos de grande fluxo turístico, atividade esta que quando não acarreta coleta de moluscos parece não afetar a densidade da população, mas sim o tamanho médio da concha através de uma redução da taxa de crescimento. A abundância da população no inverno, em comparação com a avaliação feita após a mortalidade em massa de novembro, sugere que a maior parte da população passa o inverno na faixa entremarés.

  12. Ultrastructure of the spermatogenesis of the cockle Anadara granosa L. (Bivalvia: Arcidae)

    Science.gov (United States)

    Suwanjarat, J.

    1999-11-01

    In this paper spermatogenesis and sperm ultrastructure of the cockle Anadara granosa are studied using transmission electron microscopy. The spermatocyte presents electron-dense vesicles and the arising axoneme that begins to form the flagellum. During spermatid differentiation, proacrosomal vesicles appear to migrate towards the presumptive anterior pole of the nucleus; eventually these vesicles become acrosome. The spermatozoon of Anadara granosa is of the primitive type. The acrosome, situated at the apex of the nucleus, is cap-shaped and deeply invaginated at the inner side. The spherical nucleus of the spermatozoon contains dense granular chromatin and shows invagination at the posterior poles. The centriole shows the classic nine triplets of microtubules. The middle piece consists of the centriolar complex surrounded by five giant mitochondria. It is shown that the ultrastructure of spermatozoa and spermiogenesis of Anadara granosa reveals a number of features that are common among bivalves.

  13. Genetic diversity of European populations of the invasive soft-shell clam Mya arenaria (Bivalvia)

    NARCIS (Netherlands)

    Lasota, R.; Hummel, H.; Wolowicz, M.

    2004-01-01

    The genetic diversity of the soft-shell clam Mya arenaria from seven locations in Europe (two stations in the southern Baltic Sea (the Gulf of Gdansk) and two in the North Sea (Veerse Meer and Oosterschelde), and three additional stations in the Denmark Straits and Bay of Biscay) was determined usin

  14. The complete mitochondrial genome of the grooved carpet shell, Ruditapes decussatus (Bivalvia, Veneridae

    Directory of Open Access Journals (Sweden)

    Fabrizio Ghiselli

    2017-08-01

    Full Text Available Despite the large number of animal complete mitochondrial genomes currently available in public databases, knowledge about mitochondrial genomics in invertebrates is uneven. This paper reports, for the first time, the complete mitochondrial genome of the grooved carpet shell, Ruditapes decussatus, also known as the European clam. Ruditapes decussatus is morphologically and ecologically similar to the Manila clam Ruditapes philippinarum, which has been recently introduced for aquaculture in the very same habitats of Ruditapes decussatus, and that is replacing the native species. Currently the production of the European clam is almost insignificant, nonetheless it is considered a high value product, and therefore it is an economically important species, especially in Portugal, Spain and Italy. In this work we: (i assembled Ruditapes decussatus mitochondrial genome from RNA-Seq data, and validated it by Sanger sequencing; (ii analyzed and characterized the Ruditapes decussatus mitochondrial genome, comparing its features with those of other venerid bivalves; (iii assessed mitochondrial sequence polymorphism (SP and copy number variation (CNV of tandem repeats across 26 samples. Despite using high-throughput approaches we did not find evidence for the presence of two sex-linked mitochondrial genomes, typical of the doubly uniparental inheritance of mitochondria, a phenomenon known in ∼100 bivalve species. According to our analyses, Ruditapes decussatus is more genetically similar to species of the Genus Paphia than to the congeneric Ruditapes philippinarum, a finding that bolsters the already-proposed need of a taxonomic revision. We also found a quite low genetic variability across the examined samples, with few SPs and little variability of the sequences flanking the control region (Largest Unassigned Regions (LURs. Strikingly, although we found low nucleotide variability along the entire mitochondrial genome, we observed high levels of length polymorphism in the LUR due to CNV of tandem repeats, and even a LUR length heteroplasmy in two samples. It is not clear if the lack of genetic variability in the mitochondrial genome of Ruditapes decussatus is a cause or an effect of the ongoing replacement of Ruditapes decussatus with the invasive Ruditapes philippinarum, and more analyses, especially on nuclear sequences, are required to assess this point.

  15. Recent distribution of Sphaerium nucleus (Studer, 1820 (Bivalvia: Sphaeriidae in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Tereza Kořínková

    2008-04-01

    Full Text Available Recent data about the distribution of Sphaerium nucleus in the Czech Republic are summarized and used in an attempt to evaluate its conservation status. During the last ten years, this species was found at 40 sites, mostly shallow small water bodies situated in lowland river alluviums. These types of habitats are generally endangered due to the huge human impact and exploration of these areas. The revision of voucher specimens of Sphaerium corneum s.lat. deposited in museum collections yielded a further 22 old records of S. nucleus.

  16. Some reproductive parameters of populations of Macoma calcarea (Bivalvia, Tellinidae in the Barents and Pechora Seas

    Directory of Open Access Journals (Sweden)

    Noskovich A. E.

    2017-06-01

    Full Text Available Macoma calcarea is a boreal-arctic species widespread in all the northern seas of Russia. Like all bivalve molluscs M. calcarea plays an important role in marine ecosystems. Despite the widespread use many aspects of the biology of this species have not been adequately studied. The aim of the work is to establish a number of reproductive parameters (the sexual composition, the size of sexual maturity, breeding time, the size of the embryonic shell, the size of oocytes and spermatozoa in the Barents Sea bivalve Macoma calcarea in areas with different hydrological regimes. Molluscs of the populations localized in the area of the Novaya Zemlya Archipelago, in the Varandey, Ivanovskaya, Drozdovka and Ura Bays have been investigated. The material for the study has been samples of molluscs harvested in the mouths of the Barents and Pechora Seas in the period from 2006 to 2011 by the researchers of the Murmansk Marine Biological Institute. 680 samples have been studied all in all. As a result it has been found that makoms from the Novaya Zemlya population significantly differ from molluscs of other populations in the size structure, the ratio of mature and immature individuals. Also, apparently, spawning takes place in other periods than in the southern part of the Barents Sea. The abundance of young molluscs in the Ivanovskaya, Drozdovka, Ura and Varandey Bays indicates the more successful breeding in these areas, however there is also an increased elimination of large individuals. In all areas of the study among the sexually mature molluscs the dominance of males is widespread.

  17. New bathyal species and records of Pectinoidea (Bivalvia: Propeamussiidae and Pectinidae) from Taiwan

    NARCIS (Netherlands)

    Dijkstra, H.H.; Maestrati, P.

    2009-01-01

    New species: Parvamussium liaoi n. sp., Scaeochlamys squamea n. sp. New records for Taiwan: Propeamussium siratama, Parvamussium aldeynzeri, Parvamussium cristatellum, Parvamussium undisonum, Parvamussium vesiculatum, Cic/opecten fluctuatus, Delectopecten musorstomi

  18. REVIEW: Symbiosis between the Giant Clams (Bivalvia: Cardiidae and Zooxanthellae (Dinophyceae

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    UDHI EKO HERNAWAN

    2008-01-01

    Full Text Available Giant clams are the largest bivalves in the world that maintain a mutual relationship with zooxanthellae. Individual giant clam can harbor heterogeneous zooxanthellae, at least four taxa in genus Symbiodinium. The Symbiodinium lives in the zooxanthellal tubular system, a tube structure arising from one of the diverticular duct of the clam’s stomach. Since the numbers of zooxanthellae is the one of some significant factors contributing to the clams growth and survival, the giant clams need to adjust the number of zooxanthellae for physiological reason with unclear mechanism. The important role of the symbiotic relationship to the clams can be seen on the survival, growth and nutrition of the clams. There are at least two significant factors determining the symbiosis, i.e. water temperature in related with level of light intensities and ammonium-phosphate rate. Some topic is still unclear, i.e. the determination of species in genus Symbiodinium, the mechanism for adjusting the population numbers of the algae and what kind of environmental factors determining the symbiosis. Thereby further research is still needed to clarify those missing.

  19. A review of North American Recent Radiolucina (Bivalvia, Lucinidae with the description of a new species

    Directory of Open Access Journals (Sweden)

    Elizabeth Garfinkle

    2012-07-01

    Full Text Available North American members in the genus Radiolucina are reviewed. A lectotype for the type species, Radiolucina amianta, is designated and descriptions and illustrations are provided. A description of a new species, Radiolucina jessicae, from the west coast of Mexico is presented. Key diagnostic species characteristics are outlined and compared among members of the genus.

  20. Abnormal features of Macoma balthica (Bivalvia) in the Baltic Sea: alerting symptoms of environmental adversity?

    Energy Technology Data Exchange (ETDEWEB)

    Sokolowski, Adam; Wolowicz, Maciej; Hummel, Herman; Smolarz-Gorska, Katarzyna; Fichet, Denis; Radenac, Gilles; Thiriot-Quievreux, Catherine; Namiesnik, Jacek

    2004-07-01

    Recent studies of the Baltic clam Macoma balthica (L.) from the southern Baltic (the Gulf of Gdansk) have revealed striking morphological, histological and cytogenetic features. Strong deformation of the shell, including elongation of the posterior end and the appearance of an easily visible flexure in this part, has been recorded. The population contribution of the deformed blunt shelled ('irregular') clams ranged from 0% to 65% and tended to increase with depth. The morphologically 'irregular' clams had higher accumulated tissue concentrations of trace metals (As, Ag, Cd, Pb, Cu and Zn), indicating a different metal handling ability. Adverse conditions in deeper water regions of the Gulf (e.g. hypoxia, hydrogen sulphide, elevated bioavailability of contaminants) have been suggested as inducers of the phenotypical changes (morphological deformation) in part of the population and, in parallel, of the specific physiological adaptations that result in higher metal accumulation in the 'irregular' clams. Cytogenetic and histological analyses showed the presence of tumours in gill cells and digestive system of the affected clams, the prevalence of disseminated neoplasia ranging from 0% to 94% depending on the site. The disease was manifested by a modified karyotype (i.e. an abnormal number and morphology of chromosomes), a higher activity of nucleolar organizer regions (AgNORs), and tissue lesions (enlarged cells, actively proliferative with pleomorphic nuclei). Bottom sediments showed acute toxicity and have been proposed as a source of an initialising carcinogenic factor. However, none of the ecotoxicological studies provided was successful in the clear demonstration of a single (or multifactorial) agent that can account for the disseminated neoplasia.

  1. Low Genetic Diversity and High Invasion Success of Corbicula fluminea (Bivalvia, Corbiculidae (Muller, 1774 in Portugal.

    Directory of Open Access Journals (Sweden)

    Cidália Gomes

    Full Text Available The Asian clam, Corbicula fluminea, is an invasive alien species (IAS originally from Asia that has spread worldwide causing major ecological and economic impacts in aquatic ecosystems. Here, we evaluated C. fluminea genetic (using COI mtDNA, CYTb mtDNA and 18S rDNA gene markers, morphometric and sperm morphology variation in Portuguese freshwater ecosystems. The COI marker revealed a single haplotype, which belongs to the Asian FW5 invasive lineage, suggesting a common origin for all the 13 Portuguese C. fluminea populations analysed. Morphometric analyses showed differences between the populations colonizing the North (with the exception of the Lima River and the Centre/South ecosystems. The sperm morphology examination revealed the presence of biflagellate sperm, a distinctive character of the invasive androgenetic lineages. The low genetic variability of the Portuguese C. fluminea populations and the pattern of sperm morphology have been illuminating for understanding the demographic history of this invasive species. We hypothesize that these populations were derived from a unique introductory event of a Corbicula fluminea FW5 invasive androgenic lineage in the Tejo River, which subsequently dispersed to other Portuguese freshwater ecosystems. The C. fluminea asexual reproductive mode may have assisted these populations to become highly invasive despite the low genetic diversity.

  2. Microbial distribution and abundance in the digestive system of five shipworm species (Bivalvia: Teredinidae.

    Directory of Open Access Journals (Sweden)

    Meghan A Betcher

    Full Text Available Marine bivalves of the family Teredinidae (shipworms are voracious consumers of wood in marine environments. In several shipworm species, dense communities of intracellular bacterial endosymbionts have been observed within specialized cells (bacteriocytes of the gills (ctenidia. These bacteria are proposed to contribute to digestion of wood by the host. While the microbes of shipworm gills have been studied extensively in several species, the abundance and distribution of microbes in the digestive system have not been adequately addressed. Here we use Fluorescence In-Situ Hybridization (FISH and laser scanning confocal microscopy with 16S rRNA directed oligonucleotide probes targeting all domains, domains Bacteria and Archaea, and other taxonomic groups to examine the digestive microbiota of 17 specimens from 5 shipworm species (Bankia setacea, Lyrodus pedicellatus, Lyrodus massa, Lyrodus sp. and Teredo aff. triangularis. These data reveal that the caecum, a large sac-like appendage of the stomach that typically contains large quantities of wood particles and is considered the primary site of wood digestion, harbors only very sparse microbial populations. However, a significant number of bacterial cells were observed in fecal pellets within the intestines. These results suggest that due to low abundance, bacteria in the caecum may contribute little to lignocellulose degradation. In contrast, the comparatively high population density of bacteria in the intestine suggests a possible role for intestinal bacteria in the degradation of lignocellulose.

  3. Novel Microsatellite Markers of Meretrix petechialis and Cross-species Amplification in Related Taxa (Bivalvia: Veneroida

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    Hyun-Sook Ko

    2012-11-01

    Full Text Available The Asian hard clam, Meretrix petechialis, is an economically important bivalve, but its catch and population sizes are decreasing rapidly, owing to many factors, including large-scale reclamation of its natural habitat on the western coast of the Korean peninsula. Attempts to restore the resources and production of this species require genetic structure and diversity information. In this study, we developed 15 microsatellite markers from a partial genomic library enriched in GT repeats. Nine of these markers were polymorphic, with an average allele number of six, and six were monomorphic in 95 tested individuals. No linkage disequilibrium was found between any pair of loci (p > 0.05, and deviations from the Hardy–Weinberg equilibrium (HWE test showing excess of heterozygotes was observed in only one of nine loci. In addition, no null alleles or genetic differentiation between two tested populations were detected. A cross-species amplification in 12 species of four families resulted in two M. petechialis-specific loci and three possible universal markers. This information will be useful in the future development of high-quality artificial seedlings and sustainable resource management.

  4. Cytogenetic analysis in two scallops (Bivalvia: Pectinidae) by PRINS and PI banding

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Cytogenetic analysis was performed for the bay scallop (Argopecten irradians Lamarck 1819) and the Japanese scallop (Patinopecten yessoensis Jay 1857) by primed in situ labeling (PRINS) and propidium iodide (PI) banding techniques. The PRINS analysis revealed that major rRNA genes were clustered in two loci on the telomeric regions of the short arms on two acrocentric chromosome pairs in A. irradians and on two submetacentric pairs in P. yessoensis. The histone H3 gene sites differed in number and location between these two species. The C-band-like patterns revealed by PI staining varied considerably between these two species. A. irradians displayed terminal bands at long arms on all chromosomes, centromeric bands on some pairs and interstitial bands on five pairs. P. yessoensis exhibited only centromeric bands on all chromosomes. These results would contribute to the better understanding of karyotype evolution in A. irradians and P. yessoensis.

  5. The unionid (Bivalvia) fauna of the Sipsey River in northwestern Alabama, an aquatic hotspot

    Science.gov (United States)

    McCullagh, W.H.; Williams, J.D.; McGregor, S.W.; Pierson, J.M.; Lydeard, C.

    2002-01-01

    Recent surveys for unionid bivalves were conducted in the mainstem of the Sipsey River and headwater tributaries (Tombigbee River drainage) during the summer and autumn of 1996-1999. A total of 35 species and 22 genera were found. Museum records from the upper Sipsey, based largely on the efforts of H. H. Smith during 1910-11, raised the total number of recorded unionids in the Sipsey to 42. Smith documented 25 species in the river; however, most of his collections were made in the mid- to upper-Sipsey, which has lower diversity. The three most common recently observed species in descending order of abundance were Quadrula asperata (I. Lea, 1861), Pleurobema decisum (I. Lea, 1831), and Tritogonia verrucosa (Rafinesque, 1820). Federally listed species observed recently include Lampsilis perovalis (Conrad, 1834) (threatened), Medionidus acutissimus (I. Lea, 1831) (threatened), P. decisum (endangered), P. perovatum (Conrad, 1834) (endangered), and Potamilus inflatus (I. Lea, 1831) (threatened). Species not observed recently but recorded in prior surveys include Anodontoides radiatus (Conrad, 1834), Arcidens confragosus (Say, 1829), Plectomerus dombeyanus (Valenciennes, 1827), Q. metanevra (Rafinesque, 1820), Q. stapes (I. Lea, 1831) (federally endangered), P. taitianum (I. Lea, 1834) (federally endangered), and Toxolasma parvus (Barnes, 1823). Many, species are known recently or historically by only five or fewer recorded specimens including: A. radiatus, Elliptio arctata (Conrad, 1834), Ligumia recta (Lamarck, 1819), P. taitianum, P. inflatus, Q. aspera (Lea, 1831), Q. metanevra, Q. stapes, T. parvus, Truncilla donaciformis (I. Lea, 1828), Uniomerus tetralasmus (Say, 1831), Utterbackia imbecillis (Say, 1829), A. confragosus, and P. dombeyanus. Unlike the mussel fauna of most Alabama streams, that of the Sipsey River is still relatively intact in terms of species richness despite impacts from mining, silvicultural, and agricultural activities. A concerted effort should be made to provide guidelines to manage floodplain and watershed activities to avoid future adverse impacts on this aquatic hotspot.

  6. Population dynamics of Megapitaria squalida (Bivalvia: Veneridae) at Magdalena Bay, Baja California Sur, Mexico.

    Science.gov (United States)

    Schweers, Tanja; Wolff, Matthias; Koch, Volker; Duarte, Francisco Sinsel

    2006-09-01

    The population dynamics of an intertidal population of Megapitaria squalida was studied from September 2002 to February 2003 in Bahia Magdalena, Mexico. To obtain information about the artisanal and recreational fishery of M. squalida, local fishermen at different parts of the bay were interviewed. Clam densities were determined at one unexploited and two exploited sites along perpendicular transects from the shore line. Average clam density was 2.01+/-1.41 ind/m2, densities did not differ significantly between the three sampling sites. The length-total mass relation was Mtot = 0.0001*SL3.1644 (r2 = 0.9804, n = 92) and the length-tissue mass relation was Mtis = 0.0002*SL2.7144 (r2 = 0.945, n = 92). Von Bertalanffy-growth parameters were determined using marked individuals. Strong interindividual and also seasonal differences in growth were observed. Average annual values were: K = 0.655, Linfinity = 83 mm. Since M. squalida can reach a shell length of more than 135 mm in deeper waters, it is necessary to consider intertidal and subtidal populations separately. Average total mortality (Z) was 1.61 y(-1). No fishing mortality was calculated because total mortality Z at the unexploited control site was higher than Z at the exploited sites. It appears that M. squalida migrates into deeper water with increasing shell length, as average shell length increased at lower tidal levels and marked specimens showed a clear migration towards deeper waters. As yet no overexploitation could be found in the study area.

  7. Byssogenesis in the juvenile pink heelsplitter mussel, Potamilus alatus (Bivalvia: Unionidae).

    Science.gov (United States)

    Wen, Hai B; Hua, Dan; Ma, Xue Y; Jin, Wu; Zhuang, Yan B; Gu, Ruo B; Yuan, Xin H; Du, Xin W; Xu, Pao

    2015-11-01

    The North American pink heelsplitter (Potamilus alatus) differs from most freshwater mussels in China by the ability to secrete an ephemeral byssus during its juvenile stage. In the present study, light microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to investigate this ephemeral byssal structure, and amino acid composition was analyzed and compared with that of other species. The results revealed that the byssus consists of a long byssal thread and a few adhesive plaques which are randomly set up along the thread and assembled by petioles. There is a thin but distinctive cuticle with a continuous homogeneous matrix surrounding the byssal thread. Structural variation occurred when the byssal thread was differentially stretched. Four-stranded helical primary fasciculi, which form a stable rope-like structure, become evident after removal of the cuticle. The primary fasciculi consist of bundles of hundreds of parallel secondary fasciculi, each measuring about 5 μm in diameter. All evidence indicates that the byssus of the pink heelsplitter has a significantly different macrostructure and microstructure than the permanent byssus of the marine mussel Mytilus. Byssogenesis ceases when juveniles exceed 30 mm in length, although it varies greatly even among juveniles of similar size. Byssus formation is influenced by substrate type. The unique characteristics of the byssus have important advantages for survival, transition, and aggregation during the early life history. This study not only provides first insight into the structure of the ephemeral byssus and its relationship to freshwater mussel development and growth, but also suggests possibilities for the synthesis of novel biopolymer materials particularly useful in freshwater ecosystems.

  8. The families Carditidae and Condylocardiidae in the Magellan and Perú-Chile provinces (Bivalvia: Carditoidea).

    Science.gov (United States)

    Güller, Marina; Zelaya, Diego G

    2013-01-01

    Based on the study of available types and extant collections, this paper provides a systematic revision of the living species of Carditoidea occurring in the Magellan and Perú-Chile Provinces. Out of the 19 nominal species reported for the area, eight species are recognized as valid: Cyclocardia compressa, C. spurca, C. thouarsii, C. velutina, Carditella naviformis, C. semen, C. tegulata and Carditopsis flabellum. Other eight nominal species are regarded as synonyms: Cardita magellanica of Cyclocardia velutina; Carditella pallida of C. tegulata; Cardita australis and Actinobolus philippi of Carditella naviformis; Cardium pygmaeum of Carditella semen; Cardita paeteliana of Cyclocardia spurca; Carditella pallida duodecimcostata of Carditopsis flabellum; and Cardita congelascens of Cyclocardia thouarsii. Furthermore, Cardita malvinae and Cardium parvulum are nomina dubia, and the occurrence of Carditella exulata in Magellanic waters is doubtful.

  9. NUCINELLA ALIBRANDI (CONTI, 1864 AND N. SEGUENZAE (DALL, 1898,THE LAST EUROPEAN NUCINELLIDS (BIVALVIA, PROTOBRANCHIA

    Directory of Open Access Journals (Sweden)

    RAFAEL LA PERNA

    2004-07-01

    Full Text Available The revision of the genus Nucinella Wood, 1851 from the Italian Pleistocene led to the identification of two species, Nucinella alibrandi (Conti, 1864 and N. seguenzae (Dall, 1898. The former is from the continental shelf deposit of Monte Mario (Rome, the latter from upper slope deposits in Southern Italy (Calabria and Messina. The two species are very similar to each other and differ mainly in the anterior features of hinge. The peculiar hinge of Nucinella is examined in detail and its ontogenetic changes are reported. The Tertiary to Quaternary palaeobiogeographic history of Nucinella in the European area proves the Tethyan origins of this genus. Since the closure of the seaway to the Indo-Pacific in the Early Miocene, Nucinella survived in the European waters as a Tethyan relict until the Plio-Pleistocene, when cooling caused its definitive disappearance. N. alibrandi and N. seguenzae are the last representatives of the genus in the European waters.

  10. Growth and production of Donax striatus (Bivalvia: Donacidae) from Las Balsas beach, Gibara, Cuba.

    Science.gov (United States)

    Ocaña, Frank A

    2015-09-01

    Clams of the genus Donax are worldwide the dominating group of the invertebrate community on sandy beaches. They are primary consumers that provide a significant abundance and biomass to the ecosystem. In the Caribbean, Donax striatus has an important role for nature and human, nonetheless studies on the population dynamics of this beach clam are scarce and no information exists on secondary production of this species. Growth parameters and secondary production of D. striatus were estimated from February 2008 to November 2009 at Las Balsas beach, Northeastern Cuba, in order to provide basic information for management purposes. In each month 45 samples were taken by means of a PVC corer of 0.025 m2 area and sieved with a 1 mm mesh. Animals were measured and weighted with and without shell. A total of 5 471 specimens were collected during the sampling period. Shell length ranged from 2.7-33.3 mm. Growth parameters estimated from length frequency data were L∞ = 36.1 mm, K= 0.8/yr and t0= 0.2/yr. The growth performance resulted in values of Φ'= 3.02. Life span was 2.4 yrs and mortality rate was 3.07 /yr. In 2008, mean abundance of D. striatus ranged between 17.1 - 770.7 ind./m2. In 2009 the lowest mean abundance was 34.4 and the highest was 892.5 ind./m2. During 2009 biomass and production was more than twice higher in comparison with 2008. Individual production showed highest values in the 24 mm shell size (3.74 g/m2.yr) and 25 mm (0.71 g/m2.yr), considering mass with shell and without shell, respectively. During 2009 abundance of individuals with 15 mm shell length or more increased resulting in higher biomass and production, compared to 2008. Using the conversion factor of wet mass to ash free dry mass (AFDM), annual production ranged between 2.87-6.11 g AFDM/m2.yr, resulting in a turnover rate (P/B) between 5.11 and 3.47 in 2008 and 2009, respectively. The rapid growth and high turnover rate of D. striatus suggest a rapid recovery of the population. These results support the idea that this beach clam is an important resource at Las Balsas beach. Thus its exploitation must continue with caution, and only at the level of a recreational fishery.

  11. Early development, survival and growth rates of the giant clam Tridacna crocea (Bivalvia: Tridacnidae

    Directory of Open Access Journals (Sweden)

    Miguel Mies

    2012-06-01

    Full Text Available Tridacnid clams are conspicuous inhabitants of Indo-Pacific coral reefs and are traded and cultivated for the aquarium and food industries. In the present study, daily growth rates of larvae of the giant clam Tridacna crocea were determined in the laboratory during the first week of life. Adults were induced to spawn via intra-gonadal serotonin injection through the byssal orifice. After spawning oocytes were collected, fertilized and kept in 3 L glass beakers and raceways treated with antibiotics to avoid culture contamination. Larvae were fed twice with the microalga Isochrysis galbana and zooxanthellae were also offered twice during the veliger stage (days 4 and 6. Larval length was measured using a digitizing tablet coupled to a microcomputer. Larval mortality was exponential during the first 48 hours of life declining significantly afterwards. Mean growth rate was 11.3 μm day-1, increasing after addition of symbionts to 18.0 μm day-1. Survival increased to ca. 75% after the addition of zooxanthellae. The results describe the growth curve for T. crocea larvae and suggest that the acquisition of symbionts by larvae may be useful for larval growth and survival even before larvae have attained metamorphosis.Bivalves tridacnídeos são habitantes conspícuos dos recifes da região do Indo-Pacífico e são cultivados e comercializados para os mercados alimentício e aquarista. No estudo apresentado foram determinadas as taxas de crescimento diário durante a primeira semana de vida da larva do bivalve ornamental Tridacna crocea. As matrizes foram induzidas à desova por meio de uma injeção intragonadal de serotonina realizada através do orifício bissal. Após desova, ovócitos foram coletados, fertilizados e mantidos em béqueres de vidro e tanques de fluxo contínuo tratados com antibióticos para evitar contaminação. Larvas foram alimentadas em duas ocasiões com a microalga Isochrysis galbana e zooxantelas foram oferecidas também por duas vezes. O comprimento larval foi medido através de mesa digitalizadora conectada em um microcomputador. A mortalidade larval foi exponencial durante as primeiras 48 horas de vida, diminuindo em seguida. A taxa média de crescimento foi de 11,3 μm dia-1, aumentando para 18,0 μm dia-1 após a adição de simbiontes. A sobrevivência aumentou para 75% após a adição de zooxantelas. Os resultados apresentam a curva de crescimento para a larva de T. crocea e sugerem que a aquisição de simbiontes pela larva pode ser importante para o crescimento larval e sobrevivência mesmo antes delas completarem a metamorfose.

  12. The Chamidae family (Bivalvia: Venerida in Peru, with the addition of five new records

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    Franz Cardoso

    2016-05-01

    Full Text Available The family Chamidae in Peru is revised, which includes eleven species, distributed in the genus Arcinella Schumacker, 1817 and Chama Linnaeus, 1758. Chama frondosa Broderip, 1835, Chama granti (Strong, 1934, Chama hicksi Valentich-Scott & Coan, 2010, Chama janus Reeve, 1847 and Chama producta Broderip, 1835 are recorded for the first time. Descriptions and data about distribution, ecology and other remarks are given for all species.

  13. Anatomy of Phyllodina persica (Bivalvia: Tellinidae, and its first occurrence in southeastern Brazilian waters

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    Rodrigo Cesar Marques

    2013-01-01

    Full Text Available This study presents a detailed anatomy of a rare Western Atlantic tellin, Phyllodina persica, under a comparative scenario. Some characters are shared with other tellinids such as the large hemipalps compared to gills; gills with outer demibranch with a single lamella absent from the pericardial region; the type-V stomach associated with the style sac conjoined with the proximal intestine, and distal intestine presenting a dorsal and ventral group of loops, separated by the transverse muscle. The stomach presents a laterally enlarged typhlosole, although shallow, without flange in the margins. This feature is not found in other tellinid species. Another noteworthy feature in the stomach is the aperture of both caeca, which are larger than the left pouch aperture, and as wide as the style sac aperture. Furthermore, there is an interesting small process in the anterior hinge, and a pair of oblique protractor muscles placed posteriorly to the anterior foot retractor muscle, being a new type of intrinsic muscle described in bivalves. In addition to anatomy, this study presents the southernmost record of P. persica, expanding its distribution to the southeastern region of Brazil.

  14. Redescription and anatomy of Diplodonta portesiana (d’Orbigny, 1846 (Bivalvia, Ungulinidae from Brazil

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    Bárbara Romera

    2013-03-01

    Full Text Available The present redescription of Diplodonta portesiana (d’Orbigny, 1846 is the first part of the revision of this genus in the East Atlantic. This species, despite being common in the Atlantic coast, remains poorly known. A detailed shell and anatomical study was conducted based not only on specimens from the type locality’s vicinities but also on samples from other regions. Diagnostic characters for D. portesiana includes: rounded shell with a small ligament; triangular, short and deep nymph; external micro ornamentation composed of small concavities in a concentric pattern; small adductor muscles; reduced pedal gape; pair of long hemipalps with a large area covered by folds; stomach with four ducts leading to digestive diverticula; and long intestine length. Our study suggests at least two new diagnostic characters to the genus: the two pair of muscles that controls the incurrent and excurrent openings and a residual ring-like tissue surrounding the anterior half of the posterior foot retractor muscle.

  15. Desarrollo embrionario y larval temprano de Gari solida (Gray, 1828 (Bivalvia: Psammobiidae

    Directory of Open Access Journals (Sweden)

    Ramiro Contreras

    2014-03-01

    Full Text Available Se describe el desarrollo temprano del culengue (Gari solida (Gray, 1828 hasta el estado inicial de larva velígera, a partir de dos desoves efectuados en el verano de 2009. El desove se indujo a 80 ejemplares maduros, entre 50-60 mm de longitud valvar, mediante desecación a temperatura ambiente por aproximadamente media hora y posterior choque térmico (12-14°C y 23-25°C. Los reproductores fueron previamente acondicionados durante 90 días a 14°C en promedio, alimentados con Isochrysis aff galbana (T-Iso, Chaetoceros calcitrans y Tetraselmis suecica en proporción 1:1:1, a una concentración de 300.000 cel mL-1. Los ovocitos se fertilizaron en proporción de 10:1 espermatozoide/ovocito y se incubaron en estanques de 50 L, a 15 ± 0,8°C, sin aireación, con agua de mar filtrada a 1 μm e irradiada con luz ultravioleta. Se efectuaron observaciones y mediciones de los estados de embriogénesis y larva velígera tipo D, registrándose el tiempo de duración de cada fase. La embriogénesis se completó entre 23-24 h post- fecundación (pf y el estado de larva velígera tipo D se alcanzó en 36-37 h pf, midiendo 78 ± 4,7 μm de longitud. Una cubierta gelatinosa rodea al ovocito y se mantiene hasta que se desarrolla completamente la larva D libre nadadora, en 50-52 h pf. Este trabajo constituye un primer reporte sobre el desarrollo temprano de G. solida. Para profundizar en este conocimiento sería deseable incluir técnicas de microscopía electrónica en futuros estudios.

  16. Note on the type series of Parvamussium liaoi and Scaeochlamys squamea (Bivalvia: Pectinoidea) from Taiwan

    NARCIS (Netherlands)

    Chang, C.; Cheng, S.; Dijkstra, H.H.

    2011-01-01

    Pectinoidea is a superfamily of marine bivalve mollusks. Type series of the two new Pectinoidea species, Parvamussium liaoi (Propeamussiidae) and Scaeochlamys squamea (Pectinidae), collected during deep-sea cruises off south and northeastern Taiwan in 2000 and 2001, respectively, were relocated from

  17. Two new species of dicyemid (Dicyemida: Dicyemidae) from two Australian cephalopod species: Sepioteuthis australis (Mollusca: Cephalopoda: Loliginidae) and Sepioloidea lineolata (Mollusca: Cephalopoda: Sepiadariidae).

    Science.gov (United States)

    Catalano, Sarah R; Furuya, Hidetaka

    2013-04-01

    Two new species of dicyemid parasites from Dicyema are described from 2 species of Australian cephalopods, i.e., Dicyema calamaroceum n. sp. from Sepioteuthis australis Quoy and Gaimard, 1832 (southern calamary) collected from Spencer Gulf (SG) and Gulf St Vincent (GSV), South Australia (SA), Australia, and Dicyema pyjamaceum n. sp. from Sepioloidea lineolata Quoy and Gaimard, 1832 (striped pyjama squid), collected from SG, SA, Australia. Dicyema calamaroceum is a medium sized species that reaches approximately 2,400 μm in length. The vermiform stages are characterized by having 31-34 peripheral cells, a conical calotte, and an axial cell that extends to the propolar cells. An anterior abortive axial cell is absent in vermiform embryos, and verruciform cells were not observed in nematogens and rhombogens. Infusoriform embryos consist of 39 cells; 2 nuclei are present in each urn cell, and the refringent bodies are solid. Dicyema pyjamaceum is smaller than D. calamaroceum, with a body length that reaches approximately 1,950 μm. The vermiform stages are characterized by having 20-23 peripheral cells, a cap-shaped calotte that forms a cephalic swelling together with the parapolar cells, and an axial cell that extends to the propolar cells. An anterior abortive axial cell is absent in vermiform embryos. Verruciform cells and granules in propolar cells were observed in nematogens and rhombogens. Infusoriform embryos consist of 37 cells; 2 nuclei are present in each urn cell, and the refringent bodies are solid. This represents the first description of dicyemid parasites from Australia.

  18. Hermaphroditism among dioecious Tagelus plebeius (Lightfoot, 1786) (Mollusca, Psammobiidae) and Iphigenia brasiliana (Lamarck, 1818) (Mollusca, Donacidae) on the Cachoeira River estuary, Ilhéus, Bahia, Brazil.

    Science.gov (United States)

    Ceuta, L O; Boehs, G; Santos, J J B

    2010-02-01

    The samples of Tagelus plebeius and Iphigenia brasiliana were manually collected on the Cachoeira River estuary region (Ilhéus, BA, Brazil) between August 2005 and August 2006, with a periodicity of 15 days, with 20 animals collected/sampled, performing 500 samples from each species. The animals were measured, eviscerated and kept in solution of Davidson and after 24-30 hours, they were transferred to ethanol 70%. The material was processed for routine histology, with paraffin embedding, obtaining 7 microm thick slices, stained with Harris hematoxilin and Eosin (HE). By light microscopy analysis, 2 cases of hermaphroditism (0.4%) in T. plebeius samples and one case (0.2%) in I. brasiliana were registered with predominance of female over male follicles.

  19. Especies nuevas del género Gibberula (Mollusca: Cystiscidae de Cuba y Venezuela New species of the genus Gibberula (Mollusca: Cystiscidae from Cuba and Venezuela

    Directory of Open Access Journals (Sweden)

    José Espinosa

    2011-03-01

    Full Text Available Se describen 3 especies nuevas de moluscos marinos: Gibberula palmasola sp. n., recolectada en la vegetación asociada a rocas rodeadas de sedimentos blandos en una laguna costera cercada por mangle en la península de Guanahacabibes, Cuba, y caracterizada por presentar, el animal vivo, la cabeza negra y una distribución típica de bandas negras y pardas con lunares anaranjados en el manto bajo la concha; Gibberula dosmosquises sp. n., recolectada en fondos rocosos del Caribe insular de Venezuela, se caracteriza por una discreta coloración del manto y un patrón de manchas en el pie, y Gibberula thetisae sp. n, proveniente de los pastos marinos del golfo de Batabanó, Cuba, con 3 pliegues en la columela, el último muy débil, y un labio externo casi cortante, caracteres que permiten separarla de todas las demás especies conocidas en el área antillana, aunque se desconozca la anatomía del animal. Se discute la lista de especies válidas del género para Cuba y Venezuela, y se hacen adiciones y consideraciones al complejo de especies en torno a Gibberula ubitaensis Espinosa y Ortea, 2000.Three new species of marine molluscs are described. Gibberula palmasola new species, collected in vegetation associated with rocks surrounded by soft sediments in a coastal lagoon surrounded by mangroves in Guanahacabibes Peninsula, Cuba, and characterized by a black head and typical distribution of black and brown bands and orange spots in the mantle. Gibberula dosmosquises new species, collected in rocky bottoms of a Caribbean island from Venezuela, characterized by a simple staining in the mantle and a pattern of spots on the foot, and Gibberula thetisae new species, from sea grass in the gulf of Batabano, Cuba, with shell having 3 columellar folds, the last very weak, and a sharp outer lip; although, its anatomy is not known, these conchological characters separate it from all other known species in the Antilles. Aditionally, the list of valid species for Cuba and Venezuela is discussed and some considerations about Gibberula ubitaensis Espinosa y Ortea, 2000 species complex are given.

  20. Distribucion arborea de los gastropodos cerithidea montagnei (mollusca potamidae y littorina Spp. (Mollusca, Littorinidae en el manglar de Mata de Limón, Costa Rica

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    Édgar Suarez B

    2016-03-01

    Full Text Available En el manglar de Mata de Limón, Puntarenas, Costa Rica, se estudió la distribución y preferencia por el susbtrato arbóreo de gastrópodos C. montagnei y Littorina spp. en cuatro especies de mangle, según la cantidad de moluscos observados en cada árbol y la cantidad de árboles con presencia o ausencia de ellos, en el período de setiembre de 1982 a junio de 1983. El orden de preferencia mostrado por ambos grupos de moluscos fue: 1 Rhizophora mangle, 2 Avicennia germinans, 3Pelliciera rhizophorae y 4 Laguncularia racemosa. Se discuten las posibles razones de esta preferencia. Cerithidea montagnei presentó una mayor distribución horizontal, así como una mayor abundancia respecto de Littorina spp.

  1. Study on the Late Permian Claraia in South China

    Institute of Scientific and Technical Information of China (English)

    YANG; Fengqing

    2001-01-01

    [1]Nakazawa, K., On Claraia of Kashmir and Iran, J. Paleont. Soc. Idia., 1977, 20: 194-204.[2]Kulikov, M. V., Tkachuk, G. A., On finding of Claraia (Bivalvia) in Upper Permian deposits of Northern Caucasus,Doklady Akad. Nauk. USSR, 1979, 245(4): 905-908.[3]Yin. H. F.. Uppermost Permian (Changxingian) Pectinacea from South China, Riv. Ital. Paleont., 1982, 88(3): 337-386.[4]Yin. H. F.. Bivalves near the Permian-Triassic boundary in South China, J. Paleo.,1985, 59(3): 572-600.[5]Yang. Z. Y.. Yin H. F., Wu, S. B. et al., Permian-Triassic Boundary Stratigraphy and Fauna of South China (in Chinese).Geological Memoirs, Ser. 2, No. 6, Beijing: Geological Publishing House, 1987, 56-57, 236-237.[6]Guo. F. X.. Bivalves Fossil of Yunnan (in Chinese), Kunming: Yunnan Technology Press, 1985.[7]Fang. Z. J., Discussion on Late Permian “Claraia”, Act. Palaeo. Sini. (in Chinese),1993, 2(6):653-661.[8]Zhang. Z. M.. Discussion on the ligament structure of Claraia and its evolution, Act. Palaeo. Sini. (in Chinese), 1980,19(6): 433-443.[9]Nanjing Institute of Geology and Paleontology, Academia Sinica, The Bivalves of China (in Chinese), Beijing: Science Press, 1976.[10]Zhou. Z. R.. Two ecological types of Permian Ammonoids, Science in China (in Chinese), Ser. B, 1985, (7): 648-657.[11] Stanley. S. M., Relation of shell form to life habitats of the Bivalvia (Mollusca), Geol. Soc. Amer., 1970, 125: 1-496.[12]Stanley, S. M.. tunctional morphology and evolution of byssally attached bivalve mollusks, J. Paleont, 1972, 46(2): 165-207.[13]Yin, H. F.. Ding, M. H., Zhang, K. X. et al., Late Permian-Middle Triassic Ecostratigraphy of the Yangtze Platform and Its Margins, Beijing: Science Press, 1995, 69-76.[14]Leonardi, E. Trias inferiore delle Venezie, Mem. Inst. Geol. Univ. Padova., 1935, II, 1-136.[15]Ichikawa. K. Zur Taxonomie und Phylogenie der Triadischen Pteriidae (Lamellibranch), Palaeotog., 1958, III, A, 132-212.

  2. One hundred years after Pinctada: an update on alien Mollusca in Tunisia

    Directory of Open Access Journals (Sweden)

    M. ANTIT

    2011-04-01

    The occurrence of aliens in Tunisia is balanced between presumably Lessepsian species of tropical Indo-Pacific origin, and species from other sources including species from the Tropical Atlantic introduced through shipping. Nevertheless there is a prevalence of Lessepsian species towards the Gulf of Gabes in the south, whereas the shipping activity in Tunis harbour may be the main pathway of introduction in the north.

  3. Relationship between bioenergetics responses and organic pollutants in the giant mussel, Choromytilus chorus (Mollusca: Mytilidae).

    Science.gov (United States)

    Toro, Beatriz; Navarro, Jorge M; Palma-Fleming, Hernán

    2003-05-08

    Samples of Choromytilus chorus (giant mussel) were collected at three sampling stations exposed to different degrees of pollution along the south-central portion of the Chilean coast in spring 1998 and summer 1999. Measurements were carried out on clearance rate, absorption efficiency, and oxygen consumption of the mussels under controlled laboratory conditions, and related to analytical data on organic pollutants in their tissues. Scope for growth (SFG) was employed as a physiological index to evaluate stress produced by pollutants existing at each sampling site. Individuals from San Vicente bay (highly polluted) showed negative SFG values in spring (-4.6 J/h per g) and summer (-3.5 J/h per g). These results indicated severe stress related to the accumulation of toxic compounds in their tissues. Specimens from Corral bay (medium level of pollution) gave a SFG of 15.5 J/h per g in spring and 6.5 J/h per g in summer, while those from Yaldad bay (low pollution) presented an inverse situation was observed with SFG values of 6.2 J/h per g in spring which was lower than the summer value of 25.7 J/h per g. There was a significant negative correlation between the SFG of the different populations of C. chorus and the concentrations of organochlorines (OChs) and polynuclear aromatic hydrocarbons (PAHs) in their tissues.

  4. Neuromuscular development of Aeolidiella stephanieae Valdéz, 2005 (Mollusca, Gastropoda, Nudibranchia)

    DEFF Research Database (Denmark)

    Kristof, Alen; Klussmann-Kolb, Annette

    2010-01-01

    ABSTRACT: BACKGROUND: Studies on the development of the nervous system and the musculature of invertebrates have become more sophisticated and numerous within the last decade and have proven to provide new insights into the evolutionary history of organisms. In order to provide new morphogenetic ...

  5. Invertebrate shells (mollusca, foraminifera) as pollution indicators, Red Sea Coast, Egypt

    Science.gov (United States)

    Youssef, Mohamed; Madkour, Hashem; Mansour, Abbas; Alharbi, Wedad; El-Taher, Atef

    2017-09-01

    To assess the degree of pollution and its impact on the environment along the Red Sea Coast, the most abundant nine species of recent benthic foraminifera and three species of molluscan shells have been selected for the analysis of Fe, Mn, Zn, Cu, Pb, Ni, Co, and Cd concentrations. The selected foraminiferal species are: Textularia agglutinans, Amphispsorus hemprichii, Sorites marginalis, Peneroplis planatus, Borelis schlumbergeri, Amphistegina lessonii, Ammonia beccarii, Operculina gaimairdi, and Operculinella cumingii. The selected molluscan shells are: Lambis truncata and Strombus tricornis (gastropods) and Tridacana gigas (bivalves). The inorganic material analysis of foraminifera and molluscs from the Quseir and Safaga harbors indicates that foraminifera tests include higher concentrations of heavy metals such as Fe and Mn than molluscan shells. These results are supported by the black tests of porcelaneous foraminifera and reflect iron selectivity. The Cd and Pb concentrations in molluscan shells are high in the El Esh Area because of oil pollution at this site. The Cu, Zn, and Ni concentrations in the studied invertebrates are high at Quseir Harbor and in the El Esh Area because of the strong influence of terrigenous materials that are rich in these metals. The heavy metal contamination is mostly attributed to anthropogenic sources.

  6. Alien Planorbid (Mollusca, Gastropoda Pulmonata) from South West Africa erroneously recorded as Biomphalaria Pfeifferi

    NARCIS (Netherlands)

    Bruggen, van A.C.

    1974-01-01

    In 1970 I published a record of the freshwater snail Biomphalaria pfeifferi (Krauss, 1848) (fam. Planorbidae) for South West Africa: "Sandamap Farm, Spitzkoppe" (Van Bruggen, 1970: 45, figs. 1-13). Dr. D. S. Brown of the Medical Research Council (London) kindly drew my attention to the fact that jud

  7. Nanostructure and crystallography of aberrant columnar vaterite in Corbicula fluminea (Mollusca).

    Science.gov (United States)

    Frenzel, Max; Harrison, Richard J; Harper, Elizabeth M

    2012-04-01

    Both the crystallographic and nanostructural organisation of aberrant columnar vaterite occurring in Corbicula fluminea were characterised in detail for the first time using electron microscopic and X-ray powder diffraction techniques. At the millimetre scale, only a confinement of the otherwise randomly oriented c-axis to the growth surface is observed. Domains of 100 or more individual vaterite columns with common c-axis orientation exist within this disordered material. Each column behaves as a single crystal on the scale of EBSD measurements, but is internally composed of smaller irregularly shaped and slightly misaligned crystalline units (0.3-1.3μm in dimension). These are in turn partitioned by porous boundaries into rounded nanodomains, up to 600nm in size. The geometry of the nanodomains and their respective boundaries might suggest formation by the accretion of vesicles. In addition to crystallographic textures, this observation indicates formation under significant biological control with wider implications for possible causes of the condition.

  8. The genus Alvania on the Canary Islands and Madeira (Mollusca: Gastropoda) Part 1

    NARCIS (Netherlands)

    Moolenbeek, R.G.; Hoenselaar, H.J.

    1989-01-01

    Micromolluscs of the family Rissoidae and belonging to the genus Alvania s.l. from the Canary Islands and the Madeira archipelago are revised. For several species the type locality is restricted and lectotypes are designated for Rissoa canadensis d’Orbigny, 1839, R. euchila Watson, 1886, R.

  9. The genus Alvania on the Canary islands and Madeira (Mollusca: Gastropoda), part 2 [final part

    NARCIS (Netherlands)

    Moolenbeek, R.G.; Hoenselaar, H.J.

    1998-01-01

    Five Alvania species from the Canary Islands and the Madeira Archipelago are revised. A new species to science, A. johannae is described and for three species lectotypes are designated. Altogether 13 littoral alvaniids are presently known from this area. Doubtful records are enumerated and a list of

  10. Sea Hare Aplysia punctata (Mollusca: Gastropoda) Can Maintain Shell Calcification under Extreme Ocean Acidification.

    Science.gov (United States)

    Carey, Nicholas; Dupont, Sam; Sigwart, Julia D

    2016-10-01

    Ocean acidification is expected to cause energetic constraints upon marine calcifying organisms such as molluscs and echinoderms, because of the increased costs of building or maintaining shell material in lower pH. We examined metabolic rate, shell morphometry, and calcification in the sea hare Aplysia punctata under short-term exposure (19 days) to an extreme ocean acidification scenario (pH 7.3, ∼2800 μatm pCO2), along with a group held in control conditions (pH 8.1, ∼344 μatm pCO2). This gastropod and its congeners are broadly distributed and locally abundant grazers, and have an internal shell that protects the internal organs. Specimens were examined for metabolic rate via closed-chamber respirometry, followed by removal and examination of the shell under confocal microscopy. Staining using calcein determined the amount of new calcification that occurred over 6 days at the end of the acclimation period. The width of new, pre-calcified shell on the distal shell margin was also quantified as a proxy for overall shell growth. Aplysia punctata showed a 30% reduction in metabolic rate under low pH, but calcification was not affected. This species is apparently able to maintain calcification rate even under extreme low pH, and even when under the energetic constraints of lower metabolism. This finding adds to the evidence that calcification is a largely autonomous process of crystallization that occurs as long as suitable haeomocoel conditions are preserved. There was, however, evidence that the accretion of new, noncalcified shell material may have been reduced, which would lead to overall reduced shell growth under longer-term exposures to low pH independent of calcification. Our findings highlight that the chief impact of ocean acidification upon the ability of marine invertebrates to maintain their shell under low pH may be energetic constraints that hinder growth of supporting structure, rather than maintenance of calcification.

  11. The shallow-water chitons (Mollusca, Polyplacophora of Caldera, Region of Atacama, northern Chile

    Directory of Open Access Journals (Sweden)

    Juan Francisco Araya

    2015-03-01

    Full Text Available The Molluscan species of the northern littoral of Chile have been sparsely studied. This work reviews for the first time the diversity of polyplacophoran molluscs around the port of Caldera, in the Region of Atacama (26°45’49”S; 70°45’17”W to 27°20’23”S; 70°56’46”W, northern Chile. Eleven species were found in this study: Acanthopleura echinata (Barnes, 1824; Callistochiton pulchellus (Gray, 1828; Calloplax vivipara (Plate, 1899, Chaetopleura peruviana (Lamarck, 1819; Chiton cumingsii Frembly, 1827; Chiton granosus Frembly, 1827; Chiton magnificus Deshayes, 1827; Enoplochiton niger (Barnes, 1824, Radsia barnesii (Gray, 1828, Tonicia atrata (G. B. Sowerby II, 1840 and Tonicia chilensis (Frembly, 1827. All of the species occurring in the area have distributions in the southeastern Pacific Ocean, from Ecuador to central Chile, and three of them are species endemic to the Chilean coasts (Calloplax vivipara, Radsia barnesii, and Tonicia atrata. This diversity of species is comparable to that of better surveyed faunas of central and southern Chile or Patagonia. Of the eleven species recorded, the geographic distribution records for Callistochiton pulchellus, Radsia barnesii and Tonicia atrata are extended, and Calloplax vivipara is found alive again after 40 years, filling a gap in its known distribution. Illustrations of living specimens in their habitat, distribution records and a taxonomic key for all the studied taxa are also provided.

  12. Results of the Rumphius Biohistorical Expedition to Ambon . Part 10. Mollusca, Gastropoda, Naticidae

    NARCIS (Netherlands)

    Kabat, A.R.

    2000-01-01

    The 1990 Rumphius Biohistorical Expedition to Ambon (Indonesia) made 44 collecting stations. Twenty-seven species representing 11 genera of the Naticidae (Gastropoda: Caenogastropoda) were collected at 29 stations. This paper provides keys to the genera and species, along with diagnoses and short sy

  13. A new species of hydrobiid snails (Mollusca, Gastropoda, Hydrobiidae from central Greece

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    Canella Radea

    2011-10-01

    Full Text Available A new minute valvatiform species belonging to the genus Daphniola Radoman 1973, Daphniola eptalophos sp. n., from mountain Parnassos, Greece is described. The new species has a transparent valvatiform-planispiral shell, wide and open umbilicus, grey-black pigmented soft body and head and a black penis with a small colorless outgrowth on the left side near its base. A comparative table of shell dimensions and a key to the species known for this endemic genus for Greece are provided.

  14. Vitrinellidae (Marine Mollusca Gastropoda) from Holocene deposits in Surinam (Dutch Guiana)

    NARCIS (Netherlands)

    Regteren Altena, van C.O.

    1966-01-01

    Five species of Vitrinellidae have been found in the Holocene shell ridges of Surinam. Of these, Vitrinella (Striovitrinella) cupidinensis,Cochliolepis surinamensis, and Solariorbis guianensis are new species, while Cyclostremiscus caraboboensis Weisbord is known from Pliocene beds in Venezuela and

  15. The Marine Mollusca of St. Martin, Lesser Antilles, collected by H.J. Krebs

    NARCIS (Netherlands)

    Coomans, H.E.

    1963-01-01

    In 1864 an anonymous list of species of the West Indian marine mollusks was published in Denmark. There were only twenty copies printed, seven of which were lost during transportation to the West Indies (CLENCH et al., 1947—1948, p. 23). The author was HENDRIK JOHANNES KREBS (1821—1907), Fig. 117, a

  16. Nonhemocyte sources of selected lysosomal enzymes in Biomphalaria glabrata, B. tenagophila and B. straminea (Mollusca: Pulmonata

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    Gary E. Rodrick

    1981-09-01

    Full Text Available The specific activities of acid phosphatase, alkaline phosphatase, β-glucuronidase, lysozymes, glutamate-oxalacetate transaminase and glutamate-pyruvate transaminate were determined in the head-foot and digestive gland of Brazilian Biomphalaria glabrata (Touros, B. tenagophila (Caçapava and B. straminea (Monsenhor Gil. All six enzymes were detected inthe 3000g supernatant. Both cytoplasmic enzymes, glutamate-oxalacetate and glutamate-pyruvate transaminase exhibited the highest specific activities. In the case of the four hydrolytic enzymes assayed, β-glucuronidase exhibited the highest specific activity while lysozyme showed the lowest activity. All six enzymes are thought to be produced by cells within the head-foot and digestive gland of B. glabrata, B. tenagophila and B. straminea.Foram determinadas, na massa cefalopedal e na glândula digestiva de Biomphalaria glabrata de Touros (Rio Grande do Norte B. tenagophila de Cacapava (Sao Paulo e B. straminea de Monsenhor Gil (Piauí, as atividades específicas das seguintes enzimas: fosfatase acida, fosfatase alcalina, beta-glucuronidase, lisozima, transaminase glutâmico-oxalacetica e transaminase glutâmico-piruvica. As seis enzimas referidas foram detectadas no sobrenadante a 3000g. Ambas as enzimas citoplasmaticas - transaminases glutamico-oxalacetica e glutamico-piruvica - mostraram as atividades específicas mais altas. No caso das quatro enzimas hidrolíticas, a beta-glucuronidase revelou a mais alta atividade específica, enquanto a lisozima revelou a mais baixa. E admitido que todas as seis enzimas sao produzidas por celulas presentes na massa cefalopedal e na glândula digestiva das tres especies de moluscos examinadas.

  17. A molecular method to detect and identify the native species of southwestern Atlantic Crassostrea (Mollusca: Ostreidae

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    Sandra Ludwig

    2011-08-01

    Full Text Available Among oysters, species of Crassostrea (Sacco, 1897 are the most attractive to aquaculture. In Brazil, the genus is represented by C. rhizophorae (Guilding, 1828 and C. brasiliana (Lamarck, 1819. Because the maturation and breeding technology is not well developed for these species, aquaculturists need a reliable method to decide the correct time to place spat collectors in the field, and to identify both species, which are morphologically similar. In this study a specific Multiplex PCR protocol was developed, using one pair of universal primers from 18S rDNA as a positive control and a pair of specific primers for each target species. The sensitivity and specificity of the protocol was evaluated. It detected C. rhizophorae DNA in low concentrations, and C. brasiliana DNA in even lower concentrations. Further, the Multiplex PCR proved efficient in detecting DNA in concentrations equivalent to that of a single larva of each species, either separated or combined, when mixed with total DNA extract of a plankton sample representing 1000 L of filtered water. Field tests confirmed the applicability of the protocol, which holds the promise to become an important tool for aquaculture or conservation programs, allowing for the continuous monitoring of the life cycle of C. brasiliana and C. rhizophorae, by detecting the right periods of larval release and settlement.

  18. Biological aspects of Omalonyx convexus (Mollusca, Gastropoda, Succineidae from the Rio Grande do Sul State, Brazil

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    Janine Oliveira Arruda

    2011-12-01

    Full Text Available Omalonyx convexus (Heynemann, 1868 is widely spread throughout the Rio Grande do Sul State, Brazil. The studied specimens presented in vivo, tegument and mantle coloring in variations between milky-white, orange and beige. The shell presented itself covered by the mantle in different extents; however, it was not completely covered on any of the specimens. The feeding diet is basically constituted by vegetal tissues, although non-vegetal food items were also found. The specimens were found in preserved and in polluted fresh water environments, as well as on natural and artificial substrates. The temperature throughout the day influences their placement on habitat substrates.

  19. Caracoles terrestres (Mollusca: Gastropoda) de Iturbide, Nuevo León, México

    OpenAIRE

    Correa Sandoval, Alfonso

    2015-01-01

    Catorce especies de caracoles terrestres son informadas del municipio de Iturbide, Nuevo León, México. El tipo de vegetación más rico en moluscos (11 especies) es el bosque de galería de Populus-Quercus-Juglans, con cobertura vegetal total y escasa pendiente. La distribución panamericana es el principal componente zoogeográfico Fourteen species of land snails are reported from the municipality of Iturbide, Nuevo León, México. The vegetation type with more species ( 1 1) is the Populus-Quer...

  20. The cytoskeleton of chondrocytes of Sepia officinalis (Mollusca, Cephalopoda: an immunocytochemical study

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    F Leone

    2009-06-01

    Full Text Available Our previous electron microscope study showed that chondrocytes from cephalopod cartilage possess a highly developed cytoskeleton and numerous cytoplasmic processes that ramify extensively through the tissue. We have now carried out a light microscope immunocytochemical study of chondrocytes from the orbital cartilage of Sepia officinalis to obtain indications as to the nature of the cytoskeletal components. We found clear positivity to antibodies against mammalian tubulin, vimentin, GFAP, and actin, but not keratin. The simultaneous presence of several cytoskeletal components is consistent with the hypothesis that cephalopod chondrocytes have the characteristics of both chondrocytes and osteocytes of vertebrates, which endow the tissue as a whole with some of the properties of vertebrate bone. We confirm, therefore, the presence in molluscs of the ubiquitous cytoskeletal proteins of metazoan cells that have remained highly conserved throughout phylogenetic evolution.

  1. orthodenticle/otx ortholog expression in the anterior brain and eyes of Sepia officinalis (Mollusca, Cephalopoda).

    Science.gov (United States)

    Buresi, Auxane; Baratte, Sébastien; Da Silva, Corinne; Bonnaud, Laure

    2012-01-01

    The origin of cerebral structures is a major issue in both developmental and evolutionary biology. Among Lophotrochozoans, cephalopods present both a derived nervous system and an original body plan, therefore they constitute a key model to study the evolution of nervous system and molecular processes that control the neural organization. We characterized a partial sequence of an ortholog of otx2 in Sepia officinalis embryos, a gene specific to the anterior nervous system and eye development. By in situ hybridization, we assessed the expression pattern of otx2 during S. officinalis organogenesis and we showed that otx is expressed (1) in the eyes, from early to late developmental stages as observed in other species (2) in the nervous system during late developmental stages. The otx ortholog does not appear to be required for the precocious emergence of the nervous ganglia in cephalopods and is later expressed only in the most anterior ganglia of the future brain. Finally, otx expression becomes restricted to localized part of the brain, where it could be involved in the functional specification of the central nervous system of S. officinalis. These results suggest a conserved involvement of otx in eye maturation and development of the anterior neural structures in S. officinalis.

  2. ESTs library from embryonic stages reveals tubulin and reflectin diversity in Sepia officinalis (Mollusca — Cephalopoda).

    Science.gov (United States)

    Bassaglia, Yann; Bekel, Thomas; Da Silva, Corinne; Poulain, Julie; Andouche, Aude; Navet, Sandra; Bonnaud, Laure

    2012-05-01

    New molecular resources regarding the so-called “non-standard models” in biology extend the present knowledge and are essential for molecular evolution and diversity studies (especially during the development) and evolutionary inferences about these zoological groups, or more practically for their fruitful management. Sepia officinalis, an economically important cephalopod species, is emerging as a new lophotrochozoan developmental model. We developed a large set of expressed sequence tags (ESTs) from embryonic stages of S. officinalis, yielding 19,780 non-redundant sequences (NRS). Around 75% of these sequences have no homologs in existing available databases. This set is the first developmental ESTs library in cephalopods. By exploring these NRS for tubulin, a generic protein family, and reflectin, a cephalopod specific protein family,we point out for both families a striking molecular diversity in S. officinalis.

  3. Caracterização da microbiota bacteriana de Biomphalaria glabrata (Say, 1818)(Mollusca: Gastropoda)

    OpenAIRE

    Silva, Tatiana Maria da

    2012-01-01

    Devido a grande importância da microbiota no desenvolvimento de parasitas nos invertebrados, muitos estudos vêm sendo desenvolvidos para o melhor entendimento desta interação. Desta forma, a associação entre microrganismos e seus hospedeiros invertebrados, vetores de doenças, está se tornando cada vez mais evidente. Com base nisto, o objetivo do presente estudo foi caracterizar a microbiota bacteriana de caramujos da espécie Biomphalaria glabrata, principal hospedeiro interm...

  4. Severnsia strombeulima n. gen. & sp. from Hawaii (Mollusca, Gastropoda: Caenogastropoda: Eulimidae).

    Science.gov (United States)

    Geiger, Daniel L

    2016-02-29

    The malacofauna of Hawaii is rather well-known, owing to Kay (1979) and Severns (2011). Both works stand out because they include a large number of the generally under-represented micromollusks (<5 mm). Here a striking new genus and species of a microsnail is reported from that region.

  5. A contribution to the knowledge of non-marine Mollusca of South West Africa

    NARCIS (Netherlands)

    Bruggen, van A.C.

    1970-01-01

    The moment to collate scattered notes on South West African non-marine molluscs arrived last year when Mr. B. H. Lamoral of the Natal Museum, Pietermaritzburg (South Africa), entrusted the present author with the study of material obtained during a Council of Scientific and Industrial Research (C.S.

  6. Three new species of Pruvotinidae (Mollusca: Solenogastres) from Antarctica and NW Spain

    Science.gov (United States)

    Zamarro, Maria; García-Álvarez, Oscar; Urgorri, Victoriano

    2013-09-01

    The family Pruvotinidae (Solenogastres, Cavibelonia) includes thirty species of fifteen genera grouped in five subfamilies. These subfamilies are defined by the combination of the presence or absence of hollow hook-shaped sclerites, the presence or absence of a dorsopharyngeal gland and the type of ventrolateral foregut glandular organs: type A, type C or circumpharyngeal. In this paper, three new species of the family Pruvotinidae are described: Pruvotina artabra n. sp. and Gephyroherpia impar n. sp. from NW Spain, and Pruvotina manifesta n. sp. from Antarctic Peninsula. These new descriptions increase the global knowledge of Solenogastres biodiversity.

  7. The opisthobranch gastropods (Mollusca: Heterobranchia) from Venezuela: an annotated and illustrated inventory of species.

    Science.gov (United States)

    Gutiérrez, Manuel Caballer; Ortea, Jesús; Rivero, Nelsy; Tucker, Gabriela Carias; Malaquias, Manuel António E; Narciso, Samuel

    2015-10-29

    The Caribbean waters of Venezuela are composed by a large variety of habitats, with over 2800 km of coastline, islands, and islets. This area is a transitional zone between two main biogeographic provinces, the Caribbean and the Brazilian, separated by the fresh water outflows of the Orinoco and Amazon rivers, and is therefore expected to be an area of high species diversity. However, concerning the study of molluscs, Venezuela is probably the poorest known region in the Caribbean. The best compilation of opisthobranch species known in Venezuela was produced almost a decade ago, mentioning the occurrence of 57 species, plus seven determined only to genus level. In this work, 134 species are reported for Venezuela (71 are illustrated), representing about 40 % of the entire diversity of opisthobranchs known in the Caribbean. Among the species occurring in Venezuela, 49 have here the southern limit of their distribution range and only one the northern limit. Forty-six species are recorded for the first time to the country and one is a new record for the Caribbean Sea, namely Placida cremoniana. In addition, the distribution and ecology of the species are given based in literature and new data.

  8. Molecular Phylogeny of Mobilid and Sessilid Ciliates Symbiotic in Eastern Pacific Limpets (Mollusca: Patellogastropoda).

    Science.gov (United States)

    Irwin, Nicholas A T; Lynn, Denis H

    2015-01-01

    The phylogenetic relationships of the ciliate subclass Peritrichia, composed of the orders Mobilida and Sessilida, have recently come under debate as morphological and molecular analyses have struck contrasting conclusions as to the monophyly of the group. We provide additional molecular data to assess the monophyly of the Peritrichia by sequencing the small subunit ribosomal RNA genes of two symbiotic peritrichs, Urceolaria korschelti and Scyphidia ubiquita, found inhabiting the mantle cavity of limpets. Although phylogenetic analyses indicated a nonmonophyletic Peritrichia, approximately unbiased tests revealed that the monophyletic hypothesis could not be rejected. With regard to the Mobilida, our analysis showed divergence within the family Trichodinidae related to host taxa-a molluscan clade and a fish clade. For the Sessilida, the family Scyphidiidae was sister to the Astylozoidae. In our sampling of U. korschelti and S. ubiquita, both species showed significant genetic divergence among geographically isolated, yet morphologically indistinguishable populations. We hypothesize that cryptic speciation has produced these morphologically identical species and argue that more extensive genomic analyses are required to fully assess the monophyly, biogeography, and ultimately biodiversity of the peritrichs.

  9. Patterns of diversity of the Rissoidae (Mollusca: Gastropoda) in the Atlantic and the Mediterranean region.

    Science.gov (United States)

    Ávila, Sérgio P; Goud, Jeroen; de Frias Martins, António M

    2012-01-01

    The geographical distribution of the Rissoidae in the Atlantic Ocean and Mediterranean Sea was compiled and is up-to-date until July 2011. All species were classified according to their mode of larval development (planktotrophic and nonplanktotrophic), and bathymetrical zonation (shallow species--those living between the intertidal and 50 m depth, and deep species--those usually living below 50 m depth). 542 species of Rissoidae are presently reported to the Atlantic Ocean and the Mediterranean Sea, belonging to 33 genera. The Mediterranean Sea is the most diverse site, followed by Canary Islands, Caribbean, Portugal, and Cape Verde. The Mediterranean and Cape Verde Islands are the sites with higher numbers of endemic species, with predominance of Alvania spp. in the first site, and of Alvania and Schwartziella at Cape Verde. In spite of the large number of rissoids at Madeira archipelago, a large number of species are shared with Canaries, Selvagens, and the Azores, thus only about 8% are endemic to the Madeira archipelago. Most of the 542-rissoid species that live in the Atlantic and in the Mediterranean are shallow species (323), 110 are considered as deep species, and 23 species are reported in both shallow and deep waters. There is a predominance of nonplanktotrophs in islands, seamounts, and at high and medium latitudes. This pattern is particularly evident in the genera Crisilla, Manzonia, Onoba, Porosalvania, Schwartziella, and Setia. Planktotrophic species are more abundant in the eastern Atlantic and in the Mediterranean Sea. The results of the analysis of the probable directions of faunal flows support the patterns found by both the Parsimony Analysis of Endemicity and the geographical distribution. Four main source areas for rissoids emerge: Mediterranean, Caribbean, Canaries/Madeira archipelagos, and the Cape Verde archipelago. We must stress the high percentage of endemics that occurs in the isolated islands of Saint Helena, Tristan da Cunha, Cape Verde archipelago and also the Azores, thus reinforcing the legislative protective actions that the local governments have implemented in these islands during the recent years.

  10. Mitochondrial genome of the endangered marine gastropod Strombus gigas Linnaeus, 1758 (Mollusca: Gastropoda).

    Science.gov (United States)

    Márquez, Edna J; Castro, Erick R; Alzate, Juan F

    2016-01-01

    The queen conch Strombus gigas is an endangered marine gastropod of significant economic importance across the Greater Caribbean region. This work reports for the first time the complete mitochondrial genome of S. gigas, obtained by FLX 454 pyrosequencing. The mtDNA genome encodes for 13 proteins, 22 tRNAs and 2 ribosomal RNAs. In addition, the coding sequences and gene synteny were similar to other previously reported mitogenomes of gastropods.

  11. The genus Alvania on the Canary islands and Madeira (Mollusca: Gastropoda), part 2 [final part

    NARCIS (Netherlands)

    Moolenbeek, R.G.; Hoenselaar, H.J.

    1998-01-01

    Five Alvania species from the Canary Islands and the Madeira Archipelago are revised. A new species to science, A. johannae is described and for three species lectotypes are designated. Altogether 13 littoral alvaniids are presently known from this area. Doubtful records are enumerated and a list of

  12. Unusual micrometric calcite-aragonite interface in the abalone shell Haliotis (Mollusca, Gastropoda).

    Science.gov (United States)

    Dauphin, Yannicke; Cuif, Jean-Pierre; Castillo-Michel, Hiram; Chevallard, Corinne; Farre, Bastien; Meibom, Anders

    2014-02-01

    Species of Haliotis (abalone) show high variety in structure and mineralogy of the shell. One of the European species (Haliotis tuberculata) in particular has an unusual shell structure in which calcite and aragonite coexist at a microscale with small patches of aragonite embedded in larger calcitic zones. A detailed examination of the boundary between calcite and aragonite using analytical microscopies shows that the organic contents of calcite and aragonite differ. Moreover, changes in the chemical composition of the two minerals seem to be gradual and define a micrometric zone of transition between the two main layers. A similar transition zone has been observed between the layers in more classical and regularly structured mollusk shells. The imbrication of microscopic patches of aragonite within a calcitic zone suggests the occurrence of very fast physiological changes in these taxa.

  13. Family matters: The first molecular phylogeny of the Onchidorididae Gray, 1827 (Mollusca, Gastropoda, Nudibranchia).

    Science.gov (United States)

    Hallas, Joshua M; Gosliner, Terrence M

    2015-07-01

    Recent investigations into the evolution of the Onchidorididae using morphological based methods have resulted in low support for relationships among genera. This study aims to determine if molecular data corroborates recent morphological interpretations of the evolution of Onchidorididae. Five genetic markers: 16S, 18S, 28S, cytochrome c oxidase 1 (COI) and histone 3 (H3), were sequenced from 32 species comprising Onchidorididae and five other families, three from Phanerobranchia and two from Cryptobranchia. Phylogenies were estimated using maximum likelihood, and Bayesian inference analyses; with both yielding similar topologies. Molecular analyses resulted in high support for the monophyly of the suctorian clade and the placement of the genera within Onchidorididae. However, the Onchidorididae forms a paraphyletic grouping due to the recovery of the Goniodorididae and the Akiodorididae nested within family. In addition, the placement of Corambe as the most derived member of Onchidorididae is contradicted by the present study. Rather it is sister to a large clade that includes Acanthodoris and the species traditionally placed in Onchidoris and Adalaria, now defined as Onchidorididae. We have chosen to maintain Corambidae as a distinct taxon (including Corambe and Loy), sister to Onchidorididae. We also maintain Goniodorididae, Akiodorididae and Calycidoridae (including Calycidoris and Diaphorodoris), which along with the Onchidorididae and Corambidae comprise the suctorian superfamily Onchidoridoidea. Ancestral character reconstruction also suggests that the formation of a gill pocket, a character that currently defines the Cryptobranchia, may have evolved multiple times from an ancestor that lacked the ability to retract its gills into a fully formed gill pocket. The diversity of gill morphology displayed by the Onchidoridoidea will help give new insight into the evolution of this complex character within the Nudibranchia.

  14. The continuing debate on deep molluscan phylogeny: evidence for Serialia (Mollusca, Monoplacophora + Polyplacophora).

    Science.gov (United States)

    Stöger, I; Sigwart, J D; Kano, Y; Knebelsberger, T; Marshall, B A; Schwabe, E; Schrödl, M

    2013-01-01

    Molluscs are a diverse animal phylum with a formidable fossil record. Although there is little doubt about the monophyly of the eight extant classes, relationships between these groups are controversial. We analysed a comprehensive multilocus molecular data set for molluscs, the first to include multiple species from all classes, including five monoplacophorans in both extant families. Our analyses of five markers resolve two major clades: the first includes gastropods and bivalves sister to Serialia (monoplacophorans and chitons), and the second comprises scaphopods sister to aplacophorans and cephalopods. Traditional groupings such as Testaria, Aculifera, and Conchifera are rejected by our data with significant Approximately Unbiased (AU) test values. A new molecular clock indicates that molluscs had a terminal Precambrian origin with rapid divergence of all eight extant classes in the Cambrian. The recovery of Serialia as a derived, Late Cambrian clade is potentially in line with the stratigraphic chronology of morphologically heterogeneous early mollusc fossils. Serialia is in conflict with traditional molluscan classifications and recent phylogenomic data. Yet our hypothesis, as others from molecular data, implies frequent molluscan shell and body transformations by heterochronic shifts in development and multiple convergent adaptations, leading to the variable shells and body plans in extant lineages.

  15. A study of the type series of Nautilus pompilius Linnaeus, 1758 (Mollusca, Cephalopoda, Nautilida).

    Science.gov (United States)

    Nikolaeva, Svetlana V

    2015-05-25

    Few animals are treasured by zoologists more than Nautilus, and Nautilus pompilius Linnaeus, 1758, the type species of the genus, in particular. However, the type series of this species has not been studied in great detail. According to the rules of zoological nomenclature the type series consists of all the specimens included by the author in the new nominal taxon at the time of description (whether directly or by bibliographic reference), and any evidence, published or unpublished, may be taken into account to determine what specimens are included. The type series of Nautilus pompilius includes specimens in the Linnean Society of London, the University Museum in Uppsala, and specimens figured by pre-Linnaean authors indicated by reference by Linnaeus (1758). One specimen in London and four specimens in Uppsala, which are still extant, are likely to have been known to Linnaeus at the time when he prepared the 10th Edition of Systema Naturae (Linnaeus 1758), although none of these specimens was specifically mentioned by him. Even though it is widely believed that Linnaeus (1767) designated as lectotype a specimen figured by Rumphius (1705) in his D'Amboinsche Rariteitkamer, referred to in the Systema Naturae, this presumed lectotypification is not valid because Linnaeus did not explicitly indicate that any particular specimen was considered to be the type of the species. Later lectotype designations of Rumphius' illustrations are invalid because they show three different specimens. It seems that the best approach, given the quality of the material and the lack of clarity as to its type status, would be to apply to the ICZN asking to set aside all previous type fixations and designate a neotype, preferably a DNA sequenced specimen of known provenance.

  16. Recovery of the biogenic nest habitat of Limaria hians (Mollusca: Limacea) following anthropogenic disturbance

    Science.gov (United States)

    Trigg, Colin; Moore, Colin G.

    2009-04-01

    The rate of regrowth of Limaria hians nest material, following a simulated dredging impact, was examined on an extensive L. hians bed off the west coast of Scotland. Within an area of complete coverage of the sea bed by a turf of L. hians nest material, the turf was cleared by diver from 10 × 0.25 m 2 plots and the sediment subsequently raked to simulate the passage of a scallop dredge. The areal extent and pattern of nest regrowth were recorded after 6 and 12 months. Control plots showed no significant change in 100% nest cover over the year. In the treated plots regrowth generally occurred from extension of peripheral nest material. Over the initial 6 autumn and winter months treatment plots displayed a mean regrowth of 9.2% of the cleared area, increasing to 15% in the second 6-month spring and summer period. However, no significant difference in growth was found between these periods. After 12 months half the treatment plots exhibited <25% nest cover and none of them contained nest of a thickness comparable to the surrounding bed. Conversion of regrowth rates within the treated plots to the rate of nest advance along a linear front, gave a value of 3.2 cm per year, highlighting the susceptibility of this species-rich biotope to scallop dredging.

  17. Ultrastructure developments during spermiogenesis in Polydora ciliata (Annelida: Spionidae), a parasite of mollusca

    Science.gov (United States)

    Gao, Yan; Zhang, Tao; Zhang, Libin; Qiu, Tianlong; Xue, Dongxiu; Yang, Hongsheng

    2014-12-01

    Spionid worms of Polydora ciliata inhabit the shells of many commercially important bivalves and cause disease in molluscan aquaculture. Their sperm structure is closely related to their fertilization method. To give an insight into the sperm structure and spermatogenesis, ultrastructure details of the subcellular components of germ cells during spermiogenesis of Polydora ciliata are detected by transmission electron microscopy (TEM). In P. ciliata, during spermiogenesis, chromatin is regularly arranged as dense fibrils and becomes more condensed when the nucleus elongates. Microtubules do not surround the nucleus during its elongation. The Golgi phase is characterized by the formation of proacrosomal granules within the Golgi apparatus. The proacrosomal granules fuse to form a single, spherical acrosomal vesicle that migrates to the anterior pole of the cell. At the time of nuclear condensation, mitochondria become reduced in number but increased in size, causing deep indentation at the base of the nucleus. The mid-piece has a few mitochondria. The cap phase includes the spreading of the acrosomal granule over the surface of the nucleus of the differentiating spermatid. The acrosomal phase of spermiogenesis is typically associated with changes in the shape of the nucleus, acrosome and tail. The relationship of sperm ultrastructure to spermiogenesis in spionidae species was discussed.

  18. Estudo morfométrico da concha de Lymnaea columella say, 1817 (Mollusca, Gastropoda, Pulmonata

    Directory of Open Access Journals (Sweden)

    Marlene T. Ueta

    1980-12-01

    Full Text Available Foram estudadas variações morfométricas de conchas de L. columella, provenientes de dez criadouros localizados nos seguintes municípios do Estado de São Paulo: - Campinas, Americana, Atibaia, Pirassununga, Caçapava e Taubaté. Foram analisados os diferentes tipos de ambientes onde as limneas são encontradas com maior freqüência, estabelecendo-se a época do ano com maior abundância em espécimes, que correspondeu aos meses de julho a outubro. As medidas nas conhas dos diferentes criadouros referiram-se ao comprimento e largura da concha, comprimento e largura da abertura, comprimento da espira e número de voltas. Foram estabelecidos os coeficientes de correlação e de regressão e realizadas análises de variância entre as medidas tomadas e os índices obtidos da relação entre largura/comprimento da concha. Estas conchas foram comparadas com as de L. columella, L. viator, L. cubensis da coleção do Museu Nacional do Rio de Janeiro. Para a maioria das medidas as conchas mostraram proporções constantes, embora apresentassem diferenças em relação ao desenvolvimento. A maior variação foi observada em relação ao comprimento da espira. As variações morfométricas das conchas foram relacionadas com alguns fatores externos como pH, alcalinidade, dureza e teor da água. Aparentemente apenas a dureza total da água influiu na consistência das conchas.

  19. Novas ocorrências de gastrópodes e bivalves marinhos no Brasil (Mollusca

    Directory of Open Access Journals (Sweden)

    Absalão Ricardo Silva

    2003-01-01

    Full Text Available The gastropods Costaclis egregia (Dall, 1889, Thaleia nisonis (Dall, 1889, Tjaernoeia michaeli Engl, 2001 and the bivalves Bathyarca sp., Myonera aff. ruginosa (Jeffreys, 1882 are recorded for the first time in Brazilian waters. This paper presents a brief description of these species and also include ilustrations.

  20. Structure and formation of the unusual sperm of Patelloida latistrigata (Mollusca : Patellogastropoda): implications for fertilization biology.

    Science.gov (United States)

    Hodgson, Alan N; Hodgson, Valerie; Eckelbarger, Kevin J

    2012-04-01

    The structure of the spermatozoa and spermatogenesis of the lottiid limpet Patelloida latistrigata is described by transmission electron microscopy. Although the lengths of the spermatozoa (about 60 μm) and their head region (about 12 μm) are similar to those of other patellogastropods, the structure of the sperm head and midpiece are very different. The head consists of an unusually large acrosome (about 11-μm long) with a broad posterior invagination that houses the relatively small nucleus. The midpiece mitochondria, which are rather elongate with large folded tubular cristae, are housed in a cytoplasmic sheath posterior to the nucleus. The proximal centriole is unusually elongate (about 2-μm long). The axoneme that emerges from the distal centriole is surrounded anteriorly by the cytoplasmic sheath in which the cytoplasmic side of the plasma membrane has electron-dense material. The flagellum is enlarged at its terminal end. Spermatogenesis is similar to that described for other patellogastropods. Patelloida latistrigata, therefore, has spermatozoa that seem to meet the morphological criteria of ent-aquasperm, which raises the question of whether fertilization is truly external in this limpet. However, it is also possible that the modifications to the sperm are linked to unknown specializations of the egg or egg envelope.

  1. New records for the shallow-water chiton fauna (Mollusca, Polyplacophora of the Azores (NE Atlantic

    Directory of Open Access Journals (Sweden)

    Sérgio Ávila

    2013-06-01

    Full Text Available Published records, original data from recent field work on all of the islands of the Azores (NE Atlantic, and a revision of the entire mollusc collection deposited in the Department of Biology of the University of the Azores (DBUA were used to compile a checklist of the shallow-water Polyplacophora of the Azores. Lepidochitona cf. canariensis and Tonicella rubra are reported for the first time for this archipelago, increasing the recorded Azorean fauna to seven species.

  2. Phylogenetic relationships of Nembrothinae (Mollusca: Doridacea: Polyceridae) inferred from morphology and mitochondrial DNA.

    Science.gov (United States)

    Pola, Marta; Cervera, J Lucas; Gosliner, Terrence M

    2007-06-01

    Within the Polyceridae, Nembrothinae includes some of the most striking and conspicuous sea slugs known, although several features of their biology and phylogenetic relationships remain unknown. This paper reports a phylogenetic analysis based on partial sequences of two mitochondrial genes (cytochrome c oxidase subunit I and 16S rRNA) and morphology for most species included in Nembrothinae. Our phylogenetic reconstructions using both molecular and combined morphological and molecular data support the taxonomic splitting of Nembrothinae into several taxa. Excluding one species (Tambja tentaculata), the monophyly of Roboastra was supported by all the phylogenetic analyses of the combined molecular data. Nembrotha was monophyletic both in the morphological and molecular analyses, always with high support. However, Tambja was recovered as para- or polyphyletic, depending on the analysis performed. Our study also rejects the monophyly of "phanerobranch" dorids based on molecular data.

  3. Integrative taxonomy of the genus Onchidium Buchannan, 1800 (Mollusca, Gastropoda, Pulmonata, Onchidiidae)

    Science.gov (United States)

    Dayrat, Benoît; Goulding, Tricia C.; Apte, Deepak; Bhave, Vishal; Joseph Comendador; Qua,ng, Ngô Xuân; Tan, Siong Kiat; Tan, Shau Hwai

    2016-01-01

    Abstract In an effort to clarify the species diversity of onchidiid slugs, the taxonomy of the genus Onchidium Buchannan, 1800 is revised using an integrative approach. New, fresh specimens were collected in a large number of places, including type localities. The genus Onchidium is redefined here as a clade including only three species which are strongly supported by both morphological and molecular data. All three species were already named: the type species Onchidium typhae Buchannan, 1800, Onchidium stuxbergi (Westerlund, 1883), and Onchidium reevesii (J.E. Gray, 1850). With the exception of a re-description of Onchidium typhae published in 1869, all three species are re-described here for the first time. First-hand observations on the color variation of live animals in their natural habitat are provided. The anatomy of each species is described. Important nomenclatural issues are addressed. In particular, Labella Starobogatov, 1976 is regarded as a junior synonym of Onchidium and Labella ajuthiae (Labbé, 1935) and Onchidium nigrum (Plate, 1893) are regarded as junior synonyms of Onchidium stuxbergi. The nomenclatural status of several other species names is discussed as well. Many new records are provided across South-East Asia and precise ranges of geographic distributions are provided for the genus Onchidium and its three species. Distinctive features that help distinguish the genus Onchidium from other onchidiids are provided, as well as an identification key for the three species. PMID:27917062

  4. Gastropoda(Mollusca) of Huaibei Region%淮北市的螺类

    Institute of Scientific and Technical Information of China (English)

    邓道贵; 金宏; 陈海峰

    2002-01-01

    报道了淮北市螺类共17种,其中淡水螺类15种,陆生螺类2种,分别隶属于腹足纲的6科、10属,有3种为安徽省首次记录.作者还阐述了17种螺类的生态分布、区域分布及优势种等情况.并根据淮北市的特点,对它们的开发与利用进行了初步探讨.

  5. Unraveling the evolutionary history of the Chilostoma Fitzinger, 1833 (Mollusca, Gastropoda, Pulmonata) lineages in Greece.

    Science.gov (United States)

    Psonis, Nikolaos; Vardinoyannis, Katerina; Mylonas, Moisis; Poulakakis, Nikos

    2015-10-01

    The land snails of the genus Chilostoma Fitzinger, 1833 that includes, in Greece, the (sub)genera Cattania, Josephinella and Thiessea, are highly diversified and present high levels of endemism. However, their evolutionary history is unknown and their taxonomy is complex and continuously revised. The aim of this study is to investigate the phylogenetic relationships of the lineages of the genus Chilostoma distributed in Greece based on partial DNA sequences of two mitochondrial DNA (16S rRNA and COI) genes. Complete sequences of one nuclear gene (ITS1) representing the major mitochondrial lineages were also analyzed. The phylogenetic trees revealed three distinct major clades that correspond to the three (sub)genera. Several taxonomical incongruencies were made obvious, thus, raising questions about the "true" number of species in each clade, while rendering a taxonomic re-evaluation necessary. From a phylogeographic point of view, it seems that the three major phylogenetic clades were separated in the late Miocene. They started differentiating into distinct species during the Pliocene and Pleistocene through several vicariance and dispersal events.

  6. Random walk, zonation and the food searching strategy of Terebralia palustris (Mollusca, Potamididae) in Kenya

    Science.gov (United States)

    Vannini, Marco; Cannicci, Stefano; Mrabu, Elisha; Rorandelli, Rocco; Fratini, Sara

    2008-12-01

    Terebralia palustris is a common mud-whelk present at a particularly high density in all Indo-West Pacific mangroves. Young snails feed on nothing but mud while larger specimens are able to feed on fallen leaves too. In Kenya (Mida Creek) under the canopy, competition for mangrove leaves can be very high due to the high density of Sesarmidae crabs. On open exposed muddy platforms, no Sesarmidae occur but the leaf density is very low because the leaves are only randomly present as they are deposited and removed twice a day by the tide. However, the snail density is always very high, raising the question as to whether the snails use a special searching strategy to optimize their resource finding rather than a purely random movement. By analyzing the snails' movements on a uniform area at different levels and comparing them with simulated random paths, we could show that the snails' movements are not purely random. The distribution of different size classes of T. palustris in Mida Creek was known to be quite odd: the same simulation approach suggests that the zonation asymmetry could reasonably be due to the stochastic recruitment of juveniles in space and time and maintained by a substantial long-lasting spatial inertia.

  7. How well-known is the Cephalaspidean fauna (Mollusca: Opisthobranchia) in the Indo-Pacific region?

    DEFF Research Database (Denmark)

    Cedhagen, Tomas

    1998-01-01

    The gastropod group Cephalaspidea contains about 700 recent species worldwide. The status of the research on the group, indicated as the number of described species, in the tropical Indo-Pacific region is compared with other areas. The number ofspecies are 118 in the Indo-Pacific, 168 in Japan, a...

  8. A new Taheitia species (Mollusca: Gastropoda Prosobranchia: Truncatellidae) from Irian Jaya

    NARCIS (Netherlands)

    Gittenberger, E.

    1989-01-01

    Shells and an operculum of Taheitia heinrichi spec. nov. are described from the Vogelkop area in western Irian Jaya. This new species, dedicated to the late Heinrich C. Kavelaars, is somewhat similar to T. orrae, known from the island of Biak.

  9. Proteomic analysis from the mineralized radular teeth of the giant Pacific chiton, Cryptochiton stelleri (Mollusca).

    Science.gov (United States)

    Nemoto, Michiko; Wang, Qianqian; Li, Dongsheng; Pan, Songqin; Matsunaga, Tadashi; Kisailus, David

    2012-09-01

    The biomineralized radular teeth of chitons are known to consist of iron-based magnetic crystals, associated with the maximum hardness and stiffness of any biomineral. Based on our transmission electron microscopy analysis of partially mineralized teeth, we suggest that the organic matrix within the teeth controls the iron oxide nucleation. Thus, we used Nano-LC-MS to perform a proteomic analysis of the organic matrix in radular teeth of the chiton Cryptochiton stelleri in order to identify the proteins involved in the biomineralization process. Since the genome sequence of C. stelleri is not available, cross-species similarity searching and de novo peptide sequencing were used to screen the proteins. Our results indicate that several proteins were dominant in the mineralized part of the radular teeth, amongst which, myoglobin and a highly acidic peptide were identified as possibly involved in the biomineralization process.

  10. [Biodiversity of land gastropods (Mollusca) in Sierra de San Javier Park, Tucumán, Argentina].

    Science.gov (United States)

    Miranda, María José; Cuezzo, María Gabriela

    2010-09-01

    Studies related to land mollusk diversity in tropical and subtropical forests are scarce. To assess this, a study on land snail diversity of subtropical cloudforest (Yungas) and dry forest (Chaco) areas of Sierra de San Javier Park, Tucumán, Argentina, was carried out. Taxonomic identifications were performed to species level and built a species per stations data matrix to analyze diversity patterns on qualitative and quantitative samples processed from 10x10m quadrates in altitudinal transects. Non parametric analysis (ICE, ACE, Chao 1 and Chao 2) were used to estimate the true diversity of the area, as well as the degree of undersampling and spatial aggregation of the data. Diversity was also calculated using Shannon, Simpson, Whittaker and Jaccard indices. The richness of the San Javier Park was estimated to be 32 species distributed into 13 families and 21 genera. From the total number of species collected, a single one belongs to Caenogastropoda, while the rest of the species are classified into Pulmonata Stylommatophora and Systellommatophora. The most representative family was the micromollusc Charopidae, while the most relatively abundant species was another micromollusc snail, Adelopoma tucma. Richness and diversity were slightly more elevated in dry forest areas of the Chacoan Ecoregion than in cloud forest areas of Yungas. Non parametric estimators showed that the inventory was complete. Diversity values obtained were high in comparison to previously studied areas of Northwestern Argentina. The total number of specimen collected (22 169 specimens), was higher than other published studies.

  11. Deroceras saronicum spec. nov., eine neue Nacktschneckenart aus Griechenland (Mollusca: Gastropoda: Pulmonata: Agriolimacidae)

    NARCIS (Netherlands)

    Rähle, W.

    1986-01-01

    Deroceras saronicum spec. nov., probably belonging to the subgenus Deroceras s.str., is described. The species is known from the islands of Aegina and Moni (Saronic Gulf) and from the adjacent NE. Peloponnesus, Greece. It is compared with Deroceras maltzani (SIMROTH), a similar species from southern

  12. Dating and biogeographical patterns in the sea slug genus Acanthodoris Gray, 1850 (Mollusca, Gastropoda, Nudibranchia).

    Science.gov (United States)

    Hallas, Joshua M; Simison, W Brian; Gosliner, Terrence M

    2016-04-01

    Recent studies investigating vicariance and dispersal have been focused on correlating major geological events with instances of taxonomic expansion by incorporating the fossil record with molecular clock analyses. However, this approach becomes problematic for soft-bodied organisms that are poorly represented in the fossil record. Here, we estimate the phylogenetic relationships of the nudibranch genus Acanthodoris Gray, 1850 using three molecular markers (16S, COI, H3), and then test two alternative geologically calibrated molecular clock scenarios in BEAST and their effect on ancestral area reconstruction (AAR) estimates employed in LAGRANGE. The global temperate distribution of Acanthodoris spans multiple geological barriers, including the Bering Strait (∼5.32 Mya) and the Baja Peninsula (∼5.5 Mya), both of which are used in our dating estimates. The expansion of the Atlantic Ocean (∼95-105 Mya) is also used to calibrate the relationship between A. falklandica Eliot, 1905 and A. planca Fahey and Valdés, 2005, which are distributed in southern Chile and South Africa respectively. Phylogenetic analyses recovered strong biogeographical signal and recovered two major clades representing northern and southern hemispheric distributions of Acanthodoris. When all three geological events are applied to the calibration analyses, the age for Acanthodoris is estimated to be mid-Cretaceous. When the expansion of the Atlantic Ocean is excluded from our analyses, however, Acanthodoris is estimated to be much younger, with a divergence time estimate during the Miocene. Regardless of divergence estimates, our AAR suggests that Acanthodoris may have origins in the Atlantic Ocean with the Atlantic acting as a dispersal point to the northeastern Pacific. These results suggest that Acanthodoris exhibits a rare instance of western trans-arctic expansion. This study also shows that northeast Pacific specimens of A. pilosa should be regarded as A. atrogriseata and that A. serpentinotus should be regarded as a synonym of A. pina.

  13. A new Middle Miocene Niveria Jousseaume, 1884 (Mollusca: Gastropoda: Trivioidea) from Hungary

    Science.gov (United States)

    Fehse, Dirk

    2011-02-01

    A new species of Niveria from the Middle Miocene (Badenian) of the Paratethys of Borsodbóta, Hungary is described. This species is characterized by its callused dorsum and dorsal depression. Niveria jozefgregoi sp. nov. is discussed with comparative species from the Badenian of Hungary, the Pliocene of the Mediterranean region, Florida and Recent species from Madeira and the Islas Galápagos.

  14. Isolation and characterization of a novel perivitellin from the eggs of Pomacea scalaris (Mollusca, Ampullariidae).

    Science.gov (United States)

    Ituarte, S; Dreon, M S; Ceolín, M; Heras, H

    2008-09-01

    Perivitellins are important components of the perivitelline fluid (PVF) that surrounds gastropod embryos. The glyco-lipo-carotenoprotein ovorubin (OR) from eggs of the snail Pomacea canaliculata has been the most studied to date. Here we report the characterization of scalarin (SC), a glyco-lipo-carotenoprotein from the PVF of P. scalaris. SC was purified by ultracentrifugation and exclusion chromatography. It is the major egg protein, representing 64% of the total soluble protein. The particle has a hydration density of 1.26 g/ml, an apparent molecular mass of 380 kDa and it is an elongated compact protein as estimated by small angle X-ray scattering (SAXS). It is composed of three subunits of ca. 35, 28, and 24 kDa noncovalently bonded. SC is highly glycosylated (carbohydrate content 20.1%, by wt.), with a low lipid content (0.7%), being esterified sterols, pigments and polar lipids the most abundant lipid classes. HPTLC and spectrophotometric analysis of the carotenoid fraction revealed the presence of free astaxanthin (ASX; 62.0%), and an unidentified carotenoid (38.0%). The carotenoid-apoprotein interaction was studied by spectrophotometry. Carotenoids do not seem to affect the structural characteristics of the oligomer. However, the carotenoid-protein association protected ASX against oxidation. The cross-reactivity between SC and perivitellins of P. canaliculata was tested using polyclonal antibodies (PAb) against SC, OR, and perivitellin PV2. The PAbs failed to cross-react with any egg proteins of either the same or other species. SC, among other functional similarities with OR, would be an antioxidant carrier, protecting at the same time carotenoids from oxidation in the perivitellin fluid of the egg.

  15. A Pyrenean Monacha species Monacha (Metatheba) Atacis spec. nov. (Mollusca: Gastropoda: Pulmonata)

    NARCIS (Netherlands)

    Gittenberger, E.; Winter, de A.J.

    1985-01-01

    Monacha (Metatheba) atacis spec. nov. is described from the French NE Pyrenees. The status of Metatheba, hitherto known from Caucasia and Asia Minor only, as well as that of other Monacha "subgenera" is discussed.

  16. Histochemical and ultrastructural characterization of the posterior esophagus of Bulla striata (Mollusca, Opisthobranchia).

    Science.gov (United States)

    Lobo-da-Cunha, Alexandre; Oliveira, Elsa; Ferreira, Iris; Coelho, Rita; Calado, Gonçalo

    2010-12-01

    The posterior esophagus of Bulla striata, running from the gizzard to the stomach, was investigated with light and electron microscopy to obtain new data for a comparative analysis of the digestive system in cephalaspidean opisthobranchs. In this species, the posterior esophagus can be divided into two regions. In the first, the epithelium is formed by columnar cells with apical microvilli embedded in a cuticle. Many epithelial and subepithelial secretory cells are present in this region. In both, electron-lucent secretory vesicles containing filaments and a peripheral round mass of secretory material fill the cytoplasm. These acid mucus-secreting cells may also contain a few dense secretory vesicles. In the second part of the posterior esophagus, the cuticle is absent and the epithelium is ciliated. In this region, epithelial cells may contain larger lipid droplets and glycogen reserves. Subepithelial secretory cells are not present, and in epithelial secretory cells the number of dense vesicles increases, but most secretory cells still contain some electron-lucent vesicles. These cells secrete a mixture of proteins and acid polysaccharides and should be considered seromucous. The secretory cells of the posterior esophagus are significantly different from those previously reported in the anterior esophagus of this herbivorous species.

  17. Rich and rare—First insights into species diversity and abundance of Antarctic abyssal Gastropoda (Mollusca)

    Science.gov (United States)

    Schwabe, Enrico; Michael Bohn, Jens; Engl, Winfried; Linse, Katrin; Schrödl, Michael

    2007-08-01

    The abyssal depths of the polar oceans are thought to be low in diversity compared with the shallower polar shelves and temperate and tropical deep-sea basins. Our recent study on the gastropod fauna of the deep Southern Ocean gives evidence of the existence of a rich gastropod assemblage at abyssal depths. During the ANDEEP I and II expeditions to the southern Drake Passage, Northwestern Weddell Sea, and South Sandwich Trench, gastropods were collected by bottom and Agassiz trawls, epibenthic sledge, and multicorer, at 40 stations in depths between 127 and 5194 m. On the whole, 473 specimens, corresponding to 93 species of 36 families, were obtained. Of those, 414 specimens were caught below 750 m depth and refer to 84 (90%) benthic species of 32 (89%) families. Most families were represented by a single species only. The numerically dominant families were Skeneidae and Buccinidae (with 10 and 11 species, respectively), Eulimidae and Trochidae (with 9 species each), and Turridae (6 species). Thirty-Seven benthic deep-sea species (44%) were represented by a single specimen, and another 20 species (24%) were found at a single station, suggesting that more than two thirds of Antarctic deep-sea gastropod species are very rare or have a very scattered distribution. Of the 27 species occurring at two or more deep-sea stations, 14 were collected with different gear. Approximately half of the deep-water species are new to science or have been recently described. The present investigation increases the total number of recorded benthic Antarctic deep-sea gastropods (below 750 m) from 115 to 177. The previously known depth ranges have been extended, often considerably, for 31 species. The collected deep-sea gastropods comprise both eurybathic shelf species (29%) and apparently true deep-sea species (58%); some of the latter may belong to a so far unknown Antarctic abyssal fauna. Geographical ranges of the collected Antarctic benthic deep-sea gastropod species appear limited, and all these 84 species seem endemic to Antarctica south of the Polar Front. Comparing diversity and abundances based on epibenthic sledge samples, there is no clear relationship between Antarctic deep-sea gastropod abundance and species richness with depth. However, both Antarctic and adjacent deep-sea areas are still far from being adequately sampled to allow more comprehensive conclusions.

  18. Bioaccumulation of heavy metals in mollusca species and assessment of potential risks to human health.

    Science.gov (United States)

    Abdallah, Maha Ahmed Mohamed

    2013-05-01

    Along the Alexandria coast of the Egyptian Mediterranean Sea, five edible species of bivalve molluscs and one gastropoda species (Mactra coralline, Ruditapes decussates, Paphia undulate, Venerupis rhomboids, Crista pectinata and Coralliophila meyendorffi) were analyzed for content of metals (Cadmium, Chromium, Lead, Cobalt and Nickel) in the muscle and in the sediments where they live. The potential health risks of metals to humans via consumption of seafood were assessed by estimated daily intake and target hazard quotient. Significant positive correlations (p < 0.05) were obtained between tissue concentrations for all pairs of metals, with the exception of Cadmium. Significant positive correlations were also obtained for the concentrations of Cd and Ni in tissues of all studied species relative to their concentrations in surface sediments. However, correlations between tissue and sediment concentrations for Chromium, Lead and Cobalt were negative. Ruditapes decussates and C. meyendorffi had the highest values for the summed target hazard quotient and may pose a potential risk to local inhabitants through their consumption in the diet. The potential risk would arise from exposure to high tissue concentrations of Cd and Pb, which exceeded published guidelines for safety of seafood products in some cases. Chromium contributed a considerable fraction of the total target hazard quotient for all metals combined, but did not exceed the published guidelines. Cobalt and Ni did not contribute greatly overall to the target hazard quotient, except in the case of Ni in V. rhomboids.

  19. Comparative analysis of chromosome counts infers three paleopolyploidies in the mollusca.

    Science.gov (United States)

    Hallinan, Nathaniel M; Lindberg, David R

    2011-01-01

    The study of paleopolyploidies requires the comparison of multiple whole genome sequences. If the branches of a phylogeny on which a whole-genome duplication (WGD) occurred could be identified before genome sequencing, taxa could be selected that provided a better assessment of that genome duplication. Here, we describe a likelihood model in which the number of chromosomes in a genome evolves according to a Markov process with one rate of chromosome duplication and loss that is proportional to the number of chromosomes in the genome and another stochastic rate at which every chromosome in the genome could duplicate in a single event. We compare the maximum likelihoods of a model in which the genome duplication rate varies to one in which it is fixed at zero using the Akaike information criterion, to determine if a model with WGDs is a good fit for the data. Once it has been determined that the data does fit the WGD model, we infer the phylogenetic position of paleopolyploidies by calculating the posterior probability that a WGD occurred on each branch of the taxon tree. Here, we apply this model to a molluscan tree represented by 124 taxa and infer three putative WGD events. In the Gastropoda, we identify a single branch within the Hypsogastropoda and one of two branches at the base of the Stylommatophora. We also identify one or two branches near the base of the Cephalopoda.

  20. Prestonellinae-validation of the name as a new subfamily of Bothriembryontidae (Mollusca, Gastropoda, Orthalicoidea).

    Science.gov (United States)

    Bruggen, A C Van; Herbert, David G; Breure, Abraham S H

    2016-02-29

    The affinities of the enigmatic South African land snail genus Prestonella Connolly, 1929 were discussed by Herbert (2007) and Herbert & Mitchell (2009), who showed, on the basis of morphological and molecular data, that the genus is referable to the superfamily Orthalicoidea. Currently, the three described species of Prestonella are the only known African representatives of this diverse superfamily. Earlier, van Bruggen (1978) had recognized that these species formed a distinct group and had placed them in the (new) family Prestonellidae. However, as noted by Bouchet & Rocroi (2005: 140), no diagnosis was provided by van Bruggen; the name Prestonellidae thus does not meet the requirements of ICZN Art. 13.1, and is not an available name. In this paper we will redress this issue, also taking into account more recent research which has shed light on the systematic position of this genus within the Orthalicoidea.

  1. Brazilian species of Gadila (Mollusca: Scaphopoda: Gadilidae): rediscovery of Gadila elongata comb. nov. and shell morphometrics

    OpenAIRE

    Caetano,Carlos H. S.; Victor Scarabino; Ricardo S. Absalão

    2010-01-01

    Gadila elongata comb. nov. was described in 1920 from the northern Gulf of Mexico. Until recently, it was only known from the type locality. Herein we present the first record of G. elongata from Brazil (Northeast coast, Ceará state, collected at 177 m) and a morphometrics analysis of the Brazilian species of Gadila. A multivariate Discriminant Function Analysis, based on nine shell morphometric variables (length, maximum diameter, length to maximum diameter ratio, distance of point of maximu...

  2. Holoplanktonic mollusks (Mollusca: Gastropoda) from the Gulf of California, México

    OpenAIRE

    Angulo Campillo, Orso; Aceves Medina, Gerardo; Avendaño Ibarra, Raymundo

    2011-01-01

    We compiled a checklist of holoplanktonic mollusks obtained from seven oceanographic surveys performed between 2005 and 2007 in the Gulf of California, Mexico. The checklist comprises five orders,15 families, 28 genera and 62 species, including 39 new records and two range extensions within the Gulf.

  3. Brazilian species of Gadila (Mollusca: Scaphopoda: Gadilidae: rediscovery of Gadila elongata comb. nov. and shell morphometrics

    Directory of Open Access Journals (Sweden)

    Carlos H. S. Caetano

    2010-04-01

    Full Text Available Gadila elongata comb. nov. was described in 1920 from the northern Gulf of Mexico. Until recently, it was only known from the type locality. Herein we present the first record of G. elongata from Brazil (Northeast coast, Ceará state, collected at 177 m and a morphometrics analysis of the Brazilian species of Gadila. A multivariate Discriminant Function Analysis, based on nine shell morphometric variables (length, maximum diameter, length to maximum diameter ratio, distance of point of maximum diameter from anterior aperture, maximum curvature, anterior aperture height to anterior aperture width ratio, apical aperture height, apical aperture width and apical aperture height to apical aperture width ratio enabled the distinction between all species studied. Comparisons of shell morphometrics show that length and length to maximum diameter ratio are the most important variables in the differentiation of Gadila species.

  4. Size clines and subspecies in the Streptaxid Genus Gulella PFR. (Mollusca, Gastropoda pulmonata) in Southern Africa

    NARCIS (Netherlands)

    Bruggen, van A.C.

    1980-01-01

    CONTENTS 1. Introduction.................. 3 2. Systematic part................. 6 Gulella adamsiana................. 7 Gulella darglensis................. 14 Gulella elliptica................. 19 Gulella farquhari................. 27 Gulella infrendens................ 33 Gulella planti.............

  5. An annotated list of the species of the genus Corbicula from Indonesia (Mollusca: Corbiculidae)

    NARCIS (Netherlands)

    Djajasasmita, Machfudz

    1977-01-01

    The species of the genus Corbicula known from Indonesia are alphabetically listed and noted. Sixteen out of the 35 described species are considered valid, i.e. C. gustaviana, C. moltkiana, C. sumatrana, C. tobae and C. tumida from Sumatra; C. javanica, C. pulchella and C. rivalis from Java; C.

  6. Histofisiología del epitelio renal de helix aspersa (mollusca, gastropoda, pulmonata, stylommatophora)

    OpenAIRE

    Sánchez Aguayo, Inmaculada

    1983-01-01

    La excreción es, por definición, la separación de los productos de desecho de los fluidos tisulares y corporales, y su eliminación del organismo. Además, se considera como el resultado de la filtración del líquido de la sangre, de la reabsorción de ciertos compuestos y de la secreción de sustancias en el interior de túbulos excretores. Los productos de desecho son el resultado del metabolismo celular. Aunque en general son productos finales de procesos catabólicos, también pueden incluir ...

  7. p63 in Mytilus galloprovincialis and p53 family members in the phylum Mollusca.

    Science.gov (United States)

    Stifanić, Mauro; Micić, Milena; Ramsak, Andreja; Blasković, Sanja; Ruso, Ana; Zahn, Rudolf K; Batel, Renato

    2009-11-01

    Genes of the p53 family are known to be critical regulators of the cell cycle. They have already been established as possible biomarkers. Elaborate regulation mechanisms result in numerous cDNA and protein isoforms being expressed from each gene of the p53 family. Their similarity caused an often misleading nomenclature in non-vertebrate species. The aim of the present work is a clarification of the nomenclature of molluscan p53 family sequences, an essential prerequisite for reliable interpretation of gene expression and protein function studies. Here, we report five partial cDNA and one partial genomic p63 sequences, all originating from two Mytilus galloprovincialis individuals. DNA, deduced protein sequences, and the exon/intron architecture were analyzed and compared to p53, p63 and p73 sequences from other organisms. Along with our sequences, we analyzed all similar molluscan sequences found in the GenBank database. The analysis showed our cDNA sequences code for the TAp63gamma isoform of the p63 protein, and identified all other molluscan p53 family sequences as p63 genes or their expression isoforms. Our results also indicate p63 as the ancestral gene of the p53 family as well as the only gene of the family present in non-chordate metazoan species.

  8. Phylogenetic relationships and evolution of pulmonate gastropods (Mollusca): new insights from increased taxon sampling.

    Science.gov (United States)

    Dayrat, Benoît; Conrad, Michele; Balayan, Shaina; White, Tracy R; Albrecht, Christian; Golding, Rosemary; Gomes, Suzete R; Harasewych, M G; Martins, António Manuel de Frias

    2011-05-01

    Phylogenetic relationships among higher clades of pulmonate gastropods are reconstructed based on a data set including one nuclear marker (complete ribosomal 18S) and two mitochondrial markers (partial ribosomal 16S and Cytochrome oxidase I) for a total of 96 species. Sequences for 66 of these species are new to science, with a special emphasis on sampling the Ellobiidae, Onchidiidae, and Veronicellidae. Important results include the monophyly of Systellommatophora (Onchidiidae and Veronicellidae) as well as the monophyly of Ellobiidae (including Trimusculus, Otina, and Smeagol). Relationships within Ellobiidae, Onchidiidae, and Veronicellidae are evaluated here for the first time using molecular data. Present results are compared with those from the recent literature, and the current knowledge of phylogenetic relationships among pulmonate gastropods is reviewed: despite many efforts, deep nodes are still uncertain. Identification uncertainties about early fossils of pulmonates are reviewed. Impacts of those phylogenetic and fossil record uncertainties on our understanding of the macro-evolutionary history of pulmonates, especially transitions between aquatic and terrestrial habitats, are discussed.

  9. Contribution to the knowledge of the terrestrial gastropods (Mollusca:Gastropoda from Vrachanska Planina Mountains

    Directory of Open Access Journals (Sweden)

    IVAILO K. DEDOV

    2016-05-01

    Full Text Available Gastropods fauna from the Vrachanska Planina Mountains (= Vrachanska Planina, Northwest Bulgaria, as well it presents the up to now unpublished results of several research trips of the authors and further collectors in the region. In total 90 terrestrial gastropods species are now known from this mountain area. 78 species were published from the beginning of research in this area up to recently. 56 species were confirmed with new findings and 22 species were not found again while the courses of our investigations. 12 gastropod species are newly recorded for the range.

  10. The phylogenetic position of Neritimorpha based on the mitochondrial genome of Nerita melanotragus (Mollusca: Gastropoda).

    Science.gov (United States)

    Castro, Lyda R; Colgan, D J

    2010-11-01

    This is the first report of the mitochondrial gene order and almost-complete DNA sequence of a representative of the Neritimorpha, the highest-ranking gastropod clade lacking such data. Mitochondrial gene order in Nerita is largely plesiomorphic. Its only difference from the cephalopod Octopus vulgaris is a tRNA transposition shared by Vetigastropoda and Caenogastropoda. Genome arrangements were not informative enough to resolve the evolutionary relationships of Neritimorpha, Vetigastropoda and Caenogastropoda. The sister-group taxon of Neritimorpha varied in sequence-based analyses. Some suggested that Neritimorpha is the sister group of Caenogastropoda plus Heterobranchia and some that Neritimorpha and Caenogastropoda are sister groups. No analysis significantly supported the hypothesis that Vetigastroda is more closely related to Caenogastropoda than is Neritimorpha.

  11. Mitochondrial DNA hyperdiversity and its potential causes in the marine periwinkle Melarhaphe neritoides (Mollusca: Gastropoda)

    OpenAIRE

    2016-01-01

    We report the presence of mitochondrial DNA (mtDNA) hyperdiversity in the marine periwinkle Melarhaphe neritoides (Linnaeus, 1758), the first such case among marine gastropods. Our dataset consisted of concatenated 16S-COI-Cytb gene fragments. We used Bayesian analyses to investigate three putative causes underlying genetic variation, and estimated the mtDNA mutation rate, possible signatures of selection and the effective population size of the species in the Azores archipelago. The mtDNA hy...

  12. 18S ribosomal DNA sequences provide insight into the phylogeny of patellogastropod limpets (Mollusca: Gastropoda).

    Science.gov (United States)

    Yoon, Sook Hee; Kim, Won

    2007-02-28

    To investigate the phylogeny of Patellogastropoda, the complete 18S rDNA sequences of nine patellogastropod limpets Cymbula canescens (Gmelin, 1791), Helcion dunkeri (Krauss, 1848), Patella rustica Linnaeus, 1758, Cellana toreuma (Reeve, 1855), Cellana nigrolineata (Reeve, 1854), Nacella magellanica Gmelin, 1791, Nipponacmea concinna (Lischke, 1870), Niveotectura pallida (Gould, 1859), and Lottia dorsuosa Gould, 1859 were determined. These sequences were then analyzed along with the published 18S rDNA sequences of 35 gastropods, one bivalve, and one chiton species. Phylogenetic trees were constructed by maximum parsimony, maximum likelihood, and Bayesian inference. The results of our 18S rDNA sequence analysis strongly support the monophyly of Patellogastropoda and the existence of three subgroups. Of these, two subgroups, the Patelloidea and Acmaeoidea, are closely related, with branching patterns that can be summarized as [(Cymbula + Helcion) + Patella] and [(Nipponacmea + Lottia) + Niveotectura]. The remaining subgroup, Nacelloidea, emerges as basal and paraphyletic, while its genus Cellana is monophyletic. Our analysis also indicates that the Patellogastropoda have a sister relationship with the order Cocculiniformia within the Gastropoda.

  13. Biomphalaria obstructa (Morelet, 1849: a study of topotypic specimens (Mollusca: pulmonata: planorbidae

    Directory of Open Access Journals (Sweden)

    W. Lobato Paraense

    1990-12-01

    Full Text Available A description of Biomphalaria obstructa (Morelet, 1849, based on specimens collected at its type locality - isla del carmen, state of Campeche, Mexico - is presented. The Shell is small, 13 mm in diameter, 3.5 mm in width and with 5.75 whorls in the largest specimen, thin, moderately lustrous and translucent, horn-colored. Whorls increasing regularly (neither slowly nor rapidly in diameter, rounded on the periphery side, bluntly angular on the left. Suture well-marked, deeper on the left. Right side widely concave, with first whorl deeply situated and partly hidden by the next. Left side shallower than right one, largely flattened, with first whorl plaintly visible. Aperture roundly heart-shaped, usually in the same plane as the body whorl but somewhat deflected to the left (less frequently to the right in some specimens. Peristome sharp, seldom blunt; a distinct callus on the parietal wall. A number of young shells develop one set (seldom more of apertural lamellae which tend to be resorbed as the shell grows. Absence of renal ridge. Ovotestis with about 70 mostly unbrached diverticula. Seminal vesicle beset with well-developed knoblike to fingerlike diverticula. Vaginal pouch more or less developed. Spermatheca club-shaped when empty, egg-shaped when full, and with intermediate forms between those extremes. Spermathecal body usually somewhat longer than the duct. Prostate with 7 to 20 (mean 12.06 ± 2.51 usually short diverticula which give off plumpish branches spreading out in a fan shape and overlapping to some extent their immediate neighbors. Foremost prostatic diverticulum nearly always partially or completely inserted between the spermathecal body and the uterine wall. Penial sheath consistently narrower and shorter than the prepuce. Muscular coat of the penis consisting of an inner longitudinal and an outer circular layers. Ratios between organ lengths: caudal to cephalic parts of female duct = 0.55 to 1.37 (mean 0.85 +- 0.17; cephalic parte of female duct to penial complex = 1.36 to 2.81 ((mean 1.90 +- 0.33; penial sheath to prepuce = 042 to 0.96 (mean 0.67 +- 0.13. Comparison with Morelet’s type specimens of Planorbis orbiculus and P. retusus points to the identity of those nominal species with B. obstructa.

  14. On a collection of non-marine Mollusca from Curaçao

    NARCIS (Netherlands)

    Benthem Jutting, van Tera

    1925-01-01

    About ten years ago Dr. J. H. VERNHOUT, at that time curator at the National Museum of Natural History at Leiden, gave a commentary on the present state of our knowledge about the “Land- & Freshwater-Molluscs of the Dutch West-Indian Islands” (Notes Leyden Museum, Vol. XXXVI, pag. 177—189, 1914). Af

  15. Deep-water Drilliinae, Cochlespirinae and Oenopotinae (Mollusca: Gastropoda: Turridae from the Campos Basin, southeast Brazil

    Directory of Open Access Journals (Sweden)

    Raquel Medeiros Andrade Figueira

    2010-08-01

    Full Text Available Samples of a soft-bottom community from the continental slope of Campos Basin, off southeast Brazil, were obtained between 2001 and 2003 by the Research Vessel “Astro-Garoupa” with a 0.25 m2 box corer or by dredging with a Charcot dredge. A total of 177 samples were taken at depths ranging from 700 to 1950 m. Mollusks were present at all of the stations and among Gastropoda the Turridae showed the highest diversity. Within the family Cochlespirinae we found: Leucosyrinx tenoceras (Dall, 1889, L. verrillii (Dall, 1881, expanding the known distribution of the latter species farther south, and L.? subgrundifera (Dall, 1888, which is the first record of this species for the South Atlantic and the shallowest depth at which it has ever been found. Within the family Drilliinae we found Splendrillia centimata (Dall, 1889, also the first record of this species for the South Atlantic and its shallowest depth. Within the subfamily Oenopotinae we describe here three new species in the genus Oenopota Mörch, 1852: O. seraphina n. sp., O. diabula n. sp. and O. carioca n. sp.

  16. Variaciones bioquimicas e histologicas asociadas al evento reproductivo de la hembra de Octopus mimus (Mollusca: Cephalopoda)

    National Research Council Canada - National Science Library

    Zamora C., Mauricio; Olivares P., Alberto

    2004-01-01

    ... en especial de las fibras colagenas. Las proteinas, glucidos y lipidos de la glandula digestiva y el musculo decrecen en el periodo comprendido entre la puesta y la eclosion de los huevos. Las drasticas alteraciones bioquimicas y el deterioro estructural irreversible del musculo y glandula digestiva, disminuyen las expectativas de vida, relacio...

  17. Mitochondrial DNA hyperdiversity and its potential causes in the marine periwinkle Melarhaphe neritoides (Mollusca: Gastropoda)

    Science.gov (United States)

    Mardulyn, Patrick; Hardy, Olivier J.; Jordaens, Kurt; de Frias Martins, António Manuel; Backeljau, Thierry

    2016-01-01

    We report the presence of mitochondrial DNA (mtDNA) hyperdiversity in the marine periwinkle Melarhaphe neritoides (Linnaeus, 1758), the first such case among marine gastropods. Our dataset consisted of concatenated 16S-COI-Cytb gene fragments. We used Bayesian analyses to investigate three putative causes underlying genetic variation, and estimated the mtDNA mutation rate, possible signatures of selection and the effective population size of the species in the Azores archipelago. The mtDNA hyperdiversity in M. neritoides is characterized by extremely high haplotype diversity (Hd = 0.999 ± 0.001), high nucleotide diversity (π = 0.013 ± 0.001), and neutral nucleotide diversity above the threshold of 5% (πsyn = 0.0677). Haplotype richness is very high even at spatial scales as small as 100m2. Yet, mtDNA hyperdiversity does not affect the ability of DNA barcoding to identify M. neritoides. The mtDNA hyperdiversity in M. neritoides is best explained by the remarkably high mutation rate at the COI locus (μ = 5.82 × 10−5 per site per year or μ = 1.99 × 10−4 mutations per nucleotide site per generation), whereas the effective population size of this planktonic-dispersing species is surprisingly small (Ne = 5, 256; CI = 1,312–3,7495) probably due to the putative influence of selection. Comparison with COI nucleotide diversity values in other organisms suggests that mtDNA hyperdiversity may be more frequently linked to high μ values and that mtDNA hyperdiversity may be more common across other phyla than currently appreciated. PMID:27761337

  18. A new record of marine wood-borer (Mollusca: Teredinidae) from waters off Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Raveendran, T.V.; Wagh, A.B.

    The occurrence of Teredona princesae (Sivickis) has been reported for the first time from the Exclusive Economic Zone (EEZ) off Bombay. A brief description of the pallet and distribution of this species is presented...

  19. Caribbean Bulimulus revisited: physical moves and molecular traces (Mollusca, Gastropoda, Bulimulidae

    Directory of Open Access Journals (Sweden)

    Abraham S.H. Breure

    2016-03-01

    Full Text Available Twenty-five samples of Bulimulus species are studied, partly from localities within their known distribution range, partly based on interceptions where the material originates from localities where the species seem to be recently introduced and non-native. Molecular study of cytochrome oxidase 1 (CO1 reveals the origin of some of these introductions, but is less conclusive for others. Four different methods for species delimitation were applied, which did not result in unambiguous species hypotheses. For a rapid identification of morphologically indistinct species, a more comprehensive database of sequences is needed.

  20. What explains the invading success of the aquatic mud snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca)?

    NARCIS (Netherlands)

    Alonso, A.; Castro-Diez, P.

    2008-01-01

    The spread of non-native species is one of the most harmful and least reversible disturbances in ecosystems. Species have to overcome several filters to become a pest (transport, establishment, spread and impact). Few studies have checked the traits that confer ability to overcome these steps in the