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Sample records for bivalvia ostreidae mantenidos

  1. Complete mitochondrial DNA sequence of the European flat oyster Ostrea edulis confirms Ostreidae classification

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    Morga Benjamin

    2011-10-01

    Full Text Available Abstract Background Because of its typical architecture, inheritance and small size, mitochondrial (mt DNA is widely used for phylogenetic studies. Gene order is generally conserved in most taxa although some groups show considerable variation. This is particularly true in the phylum Mollusca, especially in the Bivalvia. During the last few years, there have been significant increases in the number of complete mitochondrial sequences available. For bivalves, 35 complete mitochondrial genomes are now available in GenBank, a number that has more than doubled in the last three years, representing 6 families and 23 genera. In the current study, we determined the complete mtDNA sequence of O. edulis, the European flat oyster. We present an analysis of features of its gene content and genome organization in comparison with other Ostrea, Saccostrea and Crassostrea species. Results The Ostrea edulis mt genome is 16 320 bp in length and codes for 37 genes (12 protein-coding genes, 2 rRNAs and 23 tRNAs on the same strand. As in other Ostreidae, O. edulis mt genome contains a split of the rrnL gene and a duplication of trnM. The tRNA gene set of O. edulis, Ostrea denselamellosa and Crassostrea virginica are identical in having 23 tRNA genes, in contrast to Asian oysters, which have 25 tRNA genes (except for C. ariakensis with 24. O. edulis and O. denselamellosa share the same gene order, but differ from other Ostreidae and are closer to Crassostrea than to Saccostrea. Phylogenetic analyses reinforce the taxonomic classification of the 3 families Ostreidae, Mytilidae and Pectinidae. Within the Ostreidae family the results also reveal a closer relationship between Ostrea and Saccostrea than between Ostrea and Crassostrea. Conclusions Ostrea edulis mitogenomic analyses show a high level of conservation within the genus Ostrea, whereas they show a high level of variation within the Ostreidae family. These features provide useful information for further

  2. [Reproductive cycle of the mangrove oyster Crassostrea rhizophorae (Bivalvia: Ostreidae) in Camamu Bay, Bahia, Brasil].

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    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.

  3. Phylogenetic analysis of Thai oyster (Ostreidae) based on partial sequences of the mitochondrial 16S rDNA gene

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    Bussarawit, Somchai; Gravlund, Peter; Glenner, Henrik;

    2006-01-01

    Ten oyster species of the family Ostreidae (Subfamilies Crassostreinae and Lophinae) from Thailand were studied using morphological data and mitochondrial 16S rDNA gene sequences. Additional sequence data from five specimens of Ostreidae and one specimen of Tridacna gigas were downloaded from Gen...

  4. Tissue-specific accumulation of cadmium in subcellular compartments of eastern oysters Crassostrea virginica Gmelin (Bivalvia: Ostreidae)

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    Sokolova, I.M. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)]. E-mail: insokolo@uncc.edu; Ringwood, A.H. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Johnson, C. [Johnson C. Smith University, 100 Beatties Ford Road, Charlotte, NC 28216 (United States)

    2005-09-10

    Cadmium distribution was studied in different subcellular fractions of gill and hepatopancreas tissues of eastern oysters Crassostrea virginica. Oysters were exposed for up to 21 days to low sublethal Cd concentrations (25 {mu}g L{sup -1}). Gill and hepatopancreas tissues were sampled and divided into organelle fractions and cytosol by differential centrifugation. Organelle content of different fractions was verified by activities of marker enzymes, citrate synthase and acid phosphatase for mitochondria and lysosomes, respectively. In both tissue types, there was a significant accumulation of cadmium in cytosol reaching 230-350 ng mg{sup -1} protein. Among organelles, mitochondria were the main target for Cd bioaccumulation in gills (250-300 ng mg{sup -1} protein), whereas in hepatopancreas tissues, the highest cadmium accumulation occurred in lysosomes (90-94 ng mg{sup -1} protein). Although 75-83% of total cadmium burden was associated with the cytosol reflecting high volume fraction of this compartment, Cd concentrations in organelle fractions reached levels that could cause dysfunction of mitochondria and lysosomes. Organ- and organelle-specific patterns of cadmium bioaccumulation support our previous in vivo studies, which showed adverse effects of cadmium exposures on mitochondrial oxidation in gills and on the lysosomal system of hepatopancreas. This may have important implications for the development of biomarkers of effect for heavy metals and for understanding the mechanisms of toxic effects of metals.

  5. Morphology of the larval shell of three oyster species of the genus Crassostrea Sacco, 1897 (Bivalvia: Ostreidae).

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    Christo, S W; Absher, T M; Boehs, G

    2010-08-01

    In this study we describe the morphology of the larval shell of three oyster species of Crassostrea genus. Two species, C. rhizophorae and C. brasiliana, are native to the Brazilian coast, and C. gigas is an introduced species. Samples of laboratory reared larvae, obtained through artificial fertilisation, were collected at intervals during the cultivation process for analysis using Scanning Electron Microscopy (SEM). Prodissoconch morphology was observed in relation to the presence, position, form and number of teeth in the three larval stages: D-shaped larva, umbo larva and pediveliger. Characteristic of D-shaped larvae of C. rhizophorae was the total absence of teeth in the provinculum area while C. brasiliana and C. gigas had two anterior and two posterior teeth in each valve. In the umbo larval phase, the three species had the same number of teeth in each valve: two posterior and two anterior teeth in the right valve and three posterior and three anterior in the left valve. In the pediveliger stage the three species could be differentiated by the number of anterior teeth of the right valve: C. rhizophorae had two teeth, C. brasiliana one tooth and C. gigas three teeth.

  6. 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.

  7. 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

  8. Preferencias de consumo de cuatro forrajes por venado cola blanca (Odocoileus virginianus mantenidos en cautiverio en Yucatan

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    Israel Fernando Castillo-López

    2011-02-01

    Full Text Available El  venado cola blanca  (Odocoileus  virginianus.Zimmermann es uno de los recursos silvestres y cinegéticos más  importantes  en México.  Sin embargo,  los estudios que existen sobre  su crianza en cautiverio son insuficientes para optimizar su producción. El objetivo planteado en este trabajo fue  evaluar  la  preferencia  relativa  de  cuatro forrajes,  comparar  el  consumo  ad  libitum  del forraje nativo preferido contra un pasto de corte, en venados cola blanca mantenidos en cautiverio, y medir  la relación entre el contenido de sustancias antinutricionales de  los alimentos con el consumo.Se utilizaron cuatro venados cola blanca machos adultos  con  peso  promedio  de  45  Kg,  y  tres especies de árboles  forrajeros nativos: Leucaena leucocephala, Guazuma ulmifolia,  Brosimum alicastrum  y  el  pasto  de  corte  Pennisetum purpureum.  Para  medir  la  preferencia  se realizaron dos experimentos, mediante el diseño

  9. Cadmium exposure affects mitochondrial bioenergetics and gene expression of key mitochondrial proteins in the eastern oyster Crassostrea virginica Gmelin (Bivalvia: Ostreidae)

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    Sokolova, Inna M. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)]. E-mail: insokolo@uncc.edu; Sokolov, Eugene P. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Ponnappa, Kavita M. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)

    2005-07-01

    Cadmium is a ubiquitous and extremely toxic metal, which strongly affects mitochondrial function of aquatic organisms in vitro; however, nothing is known about the in vivo effects of sublethal concentrations of this metal on mitochondrial bioenergetics. We have studied the effects of exposure to 0 (control) or 25 {mu}g L{sup -1} (Cd-exposed) Cd{sup 2+} on mitochondrial function and gene expression of key mitochondrial proteins in the eastern oyster Crassostrea virginica. Cadmium exposure in vivo resulted in considerable accumulation of cadmium in oyster mitochondria and in a significant decrease of ADP-stimulated respiration (state 3) by 30% indicating impaired capacity for ATP production. The decrease in state 3 respiration was similar to the level of inhibition expected from the direct effects of cadmium accumulated in oyster mitochondria. On the other hand, while no effect on proton leak was expected based on the mitochondrial accumulation of cadmium, Cd-exposed oysters in fact showed a significant decline of the proton leak rate (state 4 + respiration) by 40%. This suggested a downregulation of proton leak, which correlated with a decrease in mRNA expression of a mitochondrial uncoupling protein UCP6 and two other potential uncouplers, mitochondrial substrate carriers MSC-1 and MSC-2. Expression of other key mitochondrial proteins including cytochrome c oxidase, adenine nucleotide transporter and voltage dependent anion channel was not affected by cadmium exposure. Adenylate energy charge (AEC) was significantly lower in Cd-exposed oysters; however, this was due to higher steady state ADP levels and not to the decrease in tissue ATP levels. Our data show that adjustment of the proton leak in cadmium-exposed oysters may be a compensatory mechanism, which allows them to maintain normal mitochondrial coupling and ATP levels despite the cadmium-induced inhibition of capacity for ATP production.

  10. Reproductive traits of the symbiotic pea crab Austinotheres angelicus (Crustacea, Pinnotheridae living in Saccostrea palmula (Bivalvia, Ostreidae, Pacific coast of Costa Rica

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    Carolina Salas-Moya

    2014-11-01

    Full Text Available Pea crabs of the family Pinnotheridae exhibit a symbiotic life style and live associated with a variety of different marine organisms, especially bivalves. Despite the fact that pea crabs can cause serious problems in bivalve aquaculture, the available information about the ecology of these crabs from Central America is extremely limited. Therefore, the present study aimed to describe different reproductive features of the pinnotherid crab Austinotheres angelicus associated with the oyster Saccostrea palmula in the Golfo de Nicoya, Pacific coast of Costa Rica. Monthly sampling was conducted from April to December 2012. Average carapace width (CW of the 47 analyzed ovigerous females was 7.62 mm. The species produced on average 2677 ± 1754 recently -extruded embryos with an average volume of 0.020 ± 0.003 mm3; embryo volume increased during embryogenesis by 21%, but did not vary significantly between developmental stages. Brood mass volume varied greatly (between 11.7 and 236.7 mm3, and increased significantly with female CW. Females invested on average 76.7% (minimum: 21.7%; maximum: 162.8% of their body weight in brood production, which confirms a substantially higher energy allocation for embryo production in pinnotherid crabs compared to free-living decapods.

  11. Reproductive traits of the symbiotic pea crab Austinotheres angelicus (Crustacea, Pinnotheridae) living in Saccostrea palmula (Bivalvia, Ostreidae), Pacific coast of Costa Rica

    Science.gov (United States)

    Salas-Moya, Carolina; Mena, Sebastián; Wehrtmann, Ingo S.

    2014-01-01

    Abstract Pea crabs of the family Pinnotheridae exhibit a symbiotic life style and live associated with a variety of different marine organisms, especially bivalves. Despite the fact that pea crabs can cause serious problems in bivalve aquaculture, the available information about the ecology of these crabs from Central America is extremely limited. Therefore, the present study aimed to describe different reproductive features of the pinnotherid crab Austinotheres angelicus associated with the oyster Saccostrea palmula in the Golfo de Nicoya, Pacific coast of Costa Rica. Monthly sampling was conducted from April to December 2012. Average carapace width (CW) of the 47 analyzed ovigerous females was 7.62 mm. The species produced on average 2677 ± 1754 recently -extruded embryos with an average volume of 0.020 ± 0.003 mm3; embryo volume increased during embryogenesis by 21%, but did not vary significantly between developmental stages. Brood mass volume varied greatly (between 11.7 and 236.7 mm3), and increased significantly with female CW. Females invested on average 76.7% (minimum: 21.7%; maximum: 162.8%) of their body weight in brood production, which confirms a substantially higher energy allocation for embryo production in pinnotherid crabs compared to free-living decapods. PMID:25561840

  12. Molecular characterization and expression of a novel homolog of uncoupling protein 5 (UCP5) from the eastern oyster Crassostrea virginica (Bivalvia: Ostreidae).

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    Kern, Britt; Ivanina, Anna V; Piontkivska, Helen; Sokolov, Eugene P; Sokolova, Inna M

    2009-06-01

    Uncoupling proteins (UCPs) belong to the mitochondrial anion carrier gene family which has been implicated in diverse physiological functions ranging from thermoregulation to antioxidant defense. In mammals, the UCP family is well characterized and contains five members (UCP1-5). In contrast, invertebrate homologues of uncoupling proteins are much less studied both from the viewpoints of structure and function. In this study we report nucleotide and predicted protein structure of an important member of UCP family, UCP5 from eastern oysters Crassostrea virginica. UCP5 from oysters appears to be a close homolog of the mammalian brain mitochondrial carrier protein (BMCP1, or UCP5) and is the first full-length UCP described from a Lophotrochozoan invertebrate. Evolutionary analysis of UCP sequences indicates at least three monophyletic UCP branches (UCP1-3, UCP4 and UCP5) that have diverged early in the evolution, prior to the divergence of vertebrates and invertebrates. In oysters, two forms of UCP5 transcript are found (UCP5S and UCP5L) that differ by 152 bp in length due to the presence of an intron in UCP5L. UCP5 was expressed in all studied oyster tissues, unlike mammals, where UCP5 is predominantly expressed in brains and male gonads. Hypoxia-reoxygenation stress, sublethal Cd exposure (50 ?g L(?1) Cd for 56 days) and acclimation to different temperatures (12 and 20 °C) had no significant effect on UCP5 mRNA expression in oysters indicative of its relative unimportance in antioxidant defense and temperature adaptation of oyster mitochondria. These data suggest that despite the relatively high degree of evolutionary conservation of the UCP5 amino acid sequence, its functional significance in mitochondria changed in the course of evolution of mollusks and vertebrates.

  13. Interacciones sociales de un grupo de chigüiros (Hydrochoerue hidrochaeris: mammalia, mantenidos en confinamiento estricto

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    Romero Blanca

    1992-11-01

    Full Text Available The social interactions among ten captive capybaras (hydrochoerus hydrochaeris, 8 males and 2 females, captives in an area from 5 X 9 m. were studied. There exist one dominant male sexualy prefered by females. Agression does not seem to affect the social cohesion and the scent mark does not generate territoriality in the group. The anus-genital olfaction is not exclusive between individuals oí the same sex and does not seem to be useful in the detection oí oestral behaviour in females, There in a high sexual selectivity between individuals oí different sexo There was a good harmony and tolerance among the group oí capybaras¡ depending oí social and environmental
    conditions.
    Fueron estudiadas las interrelaciones sociales en un grupo de 10 chigüiros (8 machos y 2 hembras mantenidos en confinamiento en un área de 5 X 9 m. Existe dominancia social por parte de un macho al cual las hembras prefieren sexualmente. La agresión no parece afectar la cohesión social, así como la señalización (marcación social no genera territorialidad dentro del grupo. La olfación social a nivel anogenital no es exclusiva entre individuos de diferente sexo y no parece ser útil para establecer la conducta de estro en
    las hembras. Existe una alta selectividad en cuanto a la direccionalidad de las interacciones entre ellos, siendo de máxima importancia aquellas que tienen que ver con la reproducción. La armonía y tolerancia social dentro del
    grupo fue buena. Estos patrones de conducta hacen del chigüiro una especie susceptible de criar en altas densidades.

  14. Molecular phylogenetics and systematics of the bivalve family Ostreidae based on rRNA sequence-structure models and multilocus species tree.

    Science.gov (United States)

    Salvi, Daniele; Macali, Armando; Mariottini, Paolo

    2014-01-01

    The bivalve family Ostreidae has a worldwide distribution and includes species of high economic importance. Phylogenetics and systematic of oysters based on morphology have proved difficult because of their high phenotypic plasticity. In this study we explore the phylogenetic information of the DNA sequence and secondary structure of the nuclear, fast-evolving, ITS2 rRNA and the mitochondrial 16S rRNA genes from the Ostreidae and we implemented a multi-locus framework based on four loci for oyster phylogenetics and systematics. Sequence-structure rRNA models aid sequence alignment and improved accuracy and nodal support of phylogenetic trees. In agreement with previous molecular studies, our phylogenetic results indicate that none of the currently recognized subfamilies, Crassostreinae, Ostreinae, and Lophinae, is monophyletic. Single gene trees based on Maximum likelihood (ML) and Bayesian (BA) methods and on sequence-structure ML were congruent with multilocus trees based on a concatenated (ML and BA) and coalescent based (BA) approaches and consistently supported three main clades: (i) Crassostrea, (ii) Saccostrea, and (iii) an Ostreinae-Lophinae lineage. Therefore, the subfamily Crassostreinae (including Crassostrea), Saccostreinae subfam. nov. (including Saccostrea and tentatively Striostrea) and Ostreinae (including Ostreinae and Lophinae taxa) are recognized [corrected]. Based on phylogenetic and biogeographical evidence the Asian species of Crassostrea from the Pacific Ocean are assigned to Magallana gen. nov., whereas an integrative taxonomic revision is required for the genera Ostrea and Dendostrea. This study pointed out the suitability of the ITS2 marker for DNA barcoding of oyster and the relevance of using sequence-structure rRNA models and features of the ITS2 folding in molecular phylogenetics and taxonomy. The multilocus approach allowed inferring a robust phylogeny of Ostreidae providing a broad molecular perspective on their systematics.

  15. Molecular phylogenetics and systematics of the bivalve family Ostreidae based on rRNA sequence-structure models and multilocus species tree.

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    Daniele Salvi

    Full Text Available The bivalve family Ostreidae has a worldwide distribution and includes species of high economic importance. Phylogenetics and systematic of oysters based on morphology have proved difficult because of their high phenotypic plasticity. In this study we explore the phylogenetic information of the DNA sequence and secondary structure of the nuclear, fast-evolving, ITS2 rRNA and the mitochondrial 16S rRNA genes from the Ostreidae and we implemented a multi-locus framework based on four loci for oyster phylogenetics and systematics. Sequence-structure rRNA models aid sequence alignment and improved accuracy and nodal support of phylogenetic trees. In agreement with previous molecular studies, our phylogenetic results indicate that none of the currently recognized subfamilies, Crassostreinae, Ostreinae, and Lophinae, is monophyletic. Single gene trees based on Maximum likelihood (ML and Bayesian (BA methods and on sequence-structure ML were congruent with multilocus trees based on a concatenated (ML and BA and coalescent based (BA approaches and consistently supported three main clades: (i Crassostrea, (ii Saccostrea, and (iii an Ostreinae-Lophinae lineage. Therefore, the subfamily Crassostreinae (including Crassostrea, Saccostreinae subfam. nov. (including Saccostrea and tentatively Striostrea and Ostreinae (including Ostreinae and Lophinae taxa are recognized [corrected]. Based on phylogenetic and biogeographical evidence the Asian species of Crassostrea from the Pacific Ocean are assigned to Magallana gen. nov., whereas an integrative taxonomic revision is required for the genera Ostrea and Dendostrea. This study pointed out the suitability of the ITS2 marker for DNA barcoding of oyster and the relevance of using sequence-structure rRNA models and features of the ITS2 folding in molecular phylogenetics and taxonomy. The multilocus approach allowed inferring a robust phylogeny of Ostreidae providing a broad molecular perspective on their systematics.

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

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    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.

  17. 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.

  18. 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.

  19. 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...

  20. 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...

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

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    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.

  2. [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.).

  3. 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

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

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    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.

  5. 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

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    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

  6. 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...

  7. 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.

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

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    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

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

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    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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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...

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

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    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.

  16. 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

  17. 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.

  18. 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

  19. 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.

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

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    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. 

  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

    2017-02-01

    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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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 termed dribble spawning, and is the same in all populations. The 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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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.

  13. 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)

  14. 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.

  15. 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

  16. Fauna Europaea: Mollusca – Bivalvia

    Directory of Open Access Journals (Sweden)

    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.

  17. Karyotype details of Crassostrea gryphoides (Rivalvia: Ostreidae) from central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, U.

    stream_size 4 stream_content_type text/plain stream_name Chromosome_Inf_Ser_50_7.pdf.txt stream_source_info Chromosome_Inf_Ser_50_7.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  18. 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.

  19. Comparación histomorfométrica in vitro del ligamento periodontal de premolares extraídos mantenidos en cuatro medios de conservación

    Directory of Open Access Journals (Sweden)

    I. Prokopowitsch

    2013-04-01

    Full Text Available Objetivo: El propósito de este estudio fue evaluar histológica y morfométricamente los resultados de diferentes tipos de medios de almacenamiento para los dientes avulsionados en el mantenimiento de la preservación de la integridad del ligamento periodontal. Material y métodos: Estudio de tipo experimental de laboratorio, se utilizaron veintitrés premolares extraídos por motivos ortodóncicos. Los medios de conservación evaluados fueron: leche tipo "B" y tipo "C", solución salina y medio seco. Un total de cinco dientes fueron almacenados en cada uno de los medios de conservación durante 120 minutos. Otros tres dientes sirvieron como controles fijados inmediatamente después de la extracción representando el ligamento periodontal íntegro. Los dientes se fijaron, procesaron y tiñeron con hematoxilina y eosina para evaluación histológica a través de microscopia óptica. Resultados: La edad de los pacientes que aportaron los dientes osciló entre 13 a 17 años. Los resultados de la evaluación cualitativa mostraron que la solución fisiológica fue el medio de almacenamiento más adecuado seguido de la leche tipo C y tipo B. En el análisis estadístico no hubo diferencia estadísticamente significativa entre los grupos de solución fisiológica y leche tipo C. Después de 120 minutos se encontraron diferencias estadísticamente significativas entre las alteraciones histomorfométricas del grupo control y los grupos de dientes que se mantuvieron en condiciones de humedad y los secos. Conclusión: Dados los resultados de este estudio, la solución salina (grupo II y la leche tipo C (Grupo III pueden considerarse como las formas de conservación más adecuadas de los dientes avulsionados.

  20. Recuperación de Acipenser sturio L., 1758 en Alemania: características del crecimiento de los peces juveniles mantenidos en condiciones experimentales de interior

    OpenAIRE

    Kirschbaum, F.; Gessner, J.; Williot, P.

    2001-01-01

    The survival of the highly endangered Acipenser sturio L., 1758 depends nearly exclusively upon the establishment of captive broodstocks. Such measures were initiated in Germany in 1996, due to a transfer of 40 artificially reproduced individuals from France under a co-operation agreement. We report the results of rearing these fish for a period of 3 years under freshwater conditions. During the first year the fish being exclusively fed frozen chironomid larvae (N = 40) grew from a median of ...

  1. 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.

  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. 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.

  4. Sperm structure and sperm transfer in Pseudopythina subsinuata (Bivalvia, Galeommatoidea)

    DEFF Research Database (Denmark)

    Jespersen, Åse

    2009-01-01

    to the elongate cells. Most females contain one to three "sperm trees", structures consisting of a short stem and numerous branches. They are firmly implanted in the abfrontal part of the gill filament and protrude into the posterior part of the suprabranchial (brooding) chamber. Implantation of the trees causes......Males and females of the commensal protandric bivalve Pseudopythina subsinuata have paired seminal receptacles, the interior of which contains many slender elongate cells. The testis produces small euspermatozoa and comparatively few and much larger paraspermatozoa. The 16-µm-long and 3-5-µm...... 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...

  5. 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

  6. 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....

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

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    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.

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

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    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.

  11. Efecto de la dieta artificial MP sobre la emergencia y relacion de sexos de Phymastichus coffea (Hymenoptera:Eulophidae) mantenido sobre su hueped, Hypothenemus hampei (Coleoptera: Scloytidae)a traves de generaciones contin

    Science.gov (United States)

    Phymastichus coffea La Salle (Hymenoptera: Eulophidae) is an endoparasitoid that attacks the adult coffee berry borer, Hypothenemus hampei Ferrari (Coleoptera: Scolytidae). The MP diet developed by Portilla and Streett is the only reported diet that allows cultures of P. coffea to develop and repr...

  12. Evidence of sexual transition in Leopard Grouper (Mycteroperca rosacea individuals held in captivity Evidencia de transición sexual en individuos de cabrilla sardinera (Mycteroperca rosacea mantenidos en cautiverio

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    Margarita Kiewek-Martínez

    2010-01-01

    Full Text Available This study describes histological observations of the gonads of 12 captive leopard grouper, M. rosacea maintained in captivity. Monthly gonad samples during February to April 2003, were obtained by catheterization and analyzed to determine sex and degree of ovarian development. Oocytes were classified into 5 stages of development and the frequencies were obtained to describe the oocyte distribution in the ovary. Two fish that were females in February were in a bisexual stage in March and functional males in April. The transitional stage was observed during the reproductive season and included degeneration of primary oocytes and proliferation of spermatogonia.Este estudio describe las observaciones histológicas del desarrollo gonadal de 12 individuos de la cabrilla sardinera, en condiciones de cautiverio. De febrero a abril del 2003 se obtuvieron muestras mensuales de la gónada mediante un catéter flexible, las cuales fueron analizadas para determinar el sexo del organismo y el estadio de desarrollo gonadal. Los ovocitos fueron clasificados en 5 etapas de desarrollo y se calcularon las frecuencias para determinar su distribución dentro del ovario. Dos individuos que fueron identificados como hembras en febrero, se encontraron en estadio bisexual en marzo y fueron machos funcionales en abril. Este estadio de transición se observó durante el periodo reproductor y se caracterizó por la degeneración de ovocitos primarios y la proliferación de espermatogonias.

  13. DNA barcoding reveals that the common cupped oyster in Taiwan is the Portuguese oyster Crassostrea angulata (Ostreoida; Ostreidae), not C. gigas

    Science.gov (United States)

    Hsiao, Sheng-Tai; Chuang, Shin-Chang; Chen, Kao-Sung; Ho, Ping-Ho; Wu, Chi-Lun; Chen, Chaolun Allen

    2016-01-01

    The Pacific cupped oyster, Crassostrea gigas, is one of the major aquacultural shellfish species that has been introduced to Europe and America from its native source in the West Pacific. In Taiwan, the cultivated cupped oysters along the west coast have been identified as C. gigas for over centuries; however, several molecular phylogenetic studies have cast doubt upon the existence of this species in Taiwan and adjacent waters. Indeed, our analyses of mitochondrial cytochrome oxidase I (COI) sequences from 313 Crassostrea collected from 12 locations along Taiwanese and southern Chinese coastlines confirm that all samples were the Portuguese oyster, C. angulata, rather than C. gigas. Multiple lines of evidence, including haplotypic and nucleotide diversity of the COI gene, demographic history, and population genetics, suggest that Taiwanese C. angulata is unique, probably experienced a sudden population expansion after the Last Glacial Maxima around 20,000 years ago, and has a significantly limited genetic connectivity across the Taiwan Strait. Our study applies an extended sampling and DNA barcoding to confirm the absence of C. gigas in natural and cultivated populations in Taiwan and southern China, where we only found C. angulata. We highlight the importance of conserving the gene pool of the C. angulata population in Taiwan, particularly considering the current threats by large-scale environmental disturbances such as marine pollution, habitat destruction, and climate change. PMID:27666088

  14. DNA barcoding reveals that the common cupped oyster in Taiwan is the Portuguese oyster Crassostrea angulata (Ostreoida; Ostreidae), not C. gigas

    Science.gov (United States)

    Hsiao, Sheng-Tai; Chuang, Shin-Chang; Chen, Kao-Sung; Ho, Ping-Ho; Wu, Chi-Lun; Chen, Chaolun Allen

    2016-09-01

    The Pacific cupped oyster, Crassostrea gigas, is one of the major aquacultural shellfish species that has been introduced to Europe and America from its native source in the West Pacific. In Taiwan, the cultivated cupped oysters along the west coast have been identified as C. gigas for over centuries; however, several molecular phylogenetic studies have cast doubt upon the existence of this species in Taiwan and adjacent waters. Indeed, our analyses of mitochondrial cytochrome oxidase I (COI) sequences from 313 Crassostrea collected from 12 locations along Taiwanese and southern Chinese coastlines confirm that all samples were the Portuguese oyster, C. angulata, rather than C. gigas. Multiple lines of evidence, including haplotypic and nucleotide diversity of the COI gene, demographic history, and population genetics, suggest that Taiwanese C. angulata is unique, probably experienced a sudden population expansion after the Last Glacial Maxima around 20,000 years ago, and has a significantly limited genetic connectivity across the Taiwan Strait. Our study applies an extended sampling and DNA barcoding to confirm the absence of C. gigas in natural and cultivated populations in Taiwan and southern China, where we only found C. angulata. We highlight the importance of conserving the gene pool of the C. angulata population in Taiwan, particularly considering the current threats by large-scale environmental disturbances such as marine pollution, habitat destruction, and climate change.

  15. 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...

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    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. 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.

  19. 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

  20. 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.

  1. NUCINELLA ALIBRANDI (CONTI, 1864 AND N. SEGUENZAE (DALL, 1898,THE LAST EUROPEAN NUCINELLIDS (BIVALVIA, PROTOBRANCHIA

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    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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Molecular Cytogenetics in Trough Shells (Mactridae, Bivalvia: Divergent GC-Rich Heterochromatin Content

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    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.

  7. 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...

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  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. 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. 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

  16. 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.

  17. 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.

  18. REVIEW: Symbiosis between the Giant Clams (Bivalvia: Cardiidae and Zooxanthellae (Dinophyceae

    Directory of Open Access Journals (Sweden)

    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. 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.)

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Novel Microsatellite Markers of Meretrix petechialis and Cross-species Amplification in Related Taxa (Bivalvia: Veneroida

    Directory of Open Access Journals (Sweden)

    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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. The Chamidae family (Bivalvia: Venerida in Peru, with the addition of five new records

    Directory of Open Access Journals (Sweden)

    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.

  16. 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.

  17. 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

  18. 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.

  19. 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?

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. [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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. [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.

  13. The biology and functional morphology of Macoma biota (Bivalvia: Tellinidae: Macominae

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    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.

  14. 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 ...

  15. 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

    Deep-sea mussels associated with sunken wood are less well known in terms of anatomy, biology and evolution than their bathymodioline allies from cold seeps and hydrothermal vents. During the Danish 'Ingolf Expedition' (1895-96) to the Northeast Atlantic, two pieces of pinewood were collected fro...... to its shell development, alimentary system, gill anatomy and life habits provide important clues to the evolution of the Bathymodiolinae....

  16. Winter distribution, density and size of Mesodesma mactroides (Bivalvia, Mactracea in Monte Hermoso beach (Argentina

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    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.

  17. 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.

  18. 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.

  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. 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.

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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

  8. Anatomy of Phyllodina persica (Bivalvia: Tellinidae, and its first occurrence in southeastern Brazilian waters

    Directory of Open Access Journals (Sweden)

    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.

  9. Redescription and anatomy of Diplodonta portesiana (d’Orbigny, 1846 (Bivalvia, Ungulinidae from Brazil

    Directory of Open Access Journals (Sweden)

    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.

  10. Desarrollo embrionario y larval temprano de Gari solida (Gray, 1828 (Bivalvia: Psammobiidae

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    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.

  11. Environ: E00159 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available E00159 Oyster shell (JP16) Crude drug Calcium carbonate [CPD:C08129], Scleroprotein, Calcium... phosphate, Silicate Ostreidae [TAX:6563] Same as: D06790 Osteridae Oyster shell Major component: Calcium carbonate [CPD:C08129] ...

  12. Identificación de cepas de salmonella spp resistentes a antimicrobianos, y factores de riesgo para su circulación, en aves y cerdos mantenidos en sistemas productivos de traspatio de la región del libertador general Bernardo O'Higgins, Chile

    OpenAIRE

    Gómez Vega, Elizabeth

    2013-01-01

    El actual aumento de la incidencia de Salmonella spp, ha provocado un gran impacto, tanto en la salud pública como en salud animal. Se considera que el incremento de la diseminación de los microorganismos a través de las cadenas productivas animales (bovinos, cerdos, pollos y en especial gallinas ponedoras) tiene un rol fundamental en este evento. Los principales reservorios de Salmonella spp son animales portadores asintomáticos y las fuentes de infección más frecuente son los alimentos o...

  13. 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

    Directory of Open Access Journals (Sweden)

    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.

  14. Cambios en el uso de la ostra perlera Pinctada mazatlanica (Bivalvia: Pteriidae en el Templo Mayor de Tenochtitlan Changes in the use of the pearl oyster Pinctada mazatlanica (Bivalvia: Pteriidae in the Great Temple of Tenochtitlan

    Directory of Open Access Journals (Sweden)

    Adrián Velázquez

    2007-10-01

    Full Text Available La concha del bivalvo panámico Pinctada mazatlanica fue ampliamente utilizada por las antiguas sociedades del México prehispánico; en las ofrendas enterradas en el Templo Mayor de Tenochtitlan se han encontrado alrededor de 600 objetos elaborados con ella, la mayor parte de los cuales proceden de la etapa constructiva IV (1440-1481, lo que llama la atención, ya que para entonces los mexicas no habían logrado conquistar emplazamientos en la costa del Pacífico. En los sucesivos agrandamientos arquitectónicos es notable el descenso en los objetos de la referida ostra, lo cual en principio se explicó por la mayor destrucción que éstos habían sufrido; sin embargo, el hallazgo de varios ricos depósitos en el predio conocido como Casa de las Ajaracas, correspondientes al reinado de Moctezuma II (1502-1521, en los que prácticamente se encuentra ausente la Pinctada mazatlanica, da lugar a nuevas interpretaciones. En el presente trabajo se presentan 2 posibles hipótesis para explicar el hecho anterior.The nacreous shell of the tropical Pacific mollusc Pinctada mazatlanica was widely used by the ancient inhabitants of Mexico. Around 600 pieces made of this shell have been found in offerings buried in the Great Temple of Tenochtitlan. Most of these objects come from the IVth construction stage (1440-1481, prior to the conquest of the Pacific Coast by the Aztecs. It was previously thought that the considerably smaller numbers found in the following stages were due to the greater degree of destruction suffered by the temple. Nevertheless, the almost complete absence of this material in nine offerings found recently corresponding to the VIIth construction stage (1502-1521, raise other possibilities. In this work two different hypotheses are presented to explain this observation.

  15. Características histológicas del ciclo reproductivo de Euvola ziczac (Linnaeu (Pectinidae, Bivalvia del litoral sur-sudeste del Brasil Histological characteristics of the reproductive cycle of Euvola ziczac (Pectinidae, Bivalvia from south-southern Brazil

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    Carlos Alberto Borzone

    2003-12-01

    Full Text Available Scallops were collected from beds at 30 to 40 m depth on the south-southern inner continental shelf of Brazil for histological gonadal characterization of the reproductive cycle. This hermaphroditic scallop was an important shellfish resource during 70-80 decade, with maximal annual landings of 8,845 tons, but now is depleted. Results shows that reproduction is continuous, with two major spawning periods, the first during end of summer and throughout autumn, and the second during winter and beginning of spring. A characteristic phenomenon of oocyte atresia, with maximal incidences in September is described. This phenomenon, followed by the mature oocyte resorption and new oocyte proliferation and maturation, was related to the lack of spawning stimulation. A semi-annual thermal cycle on the bottom water due to the South Atlantic Central Water intrusion seems to be the principal reproductive cycle controller. Fluctuations in landings registered since the beginning of the fishery may be partly related to oceanographic variations.

  16. Biologia e anatomia funcional de Donax gemmula Morrison (Bivalvia, Donacidae do litoral de São Paulo, Brasil Biology and functional anatomy of Donax gemmula Morrison (Bivalvia, Donacidae from the littoral of São Paulo, Brazil

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    Flávio Dias Passos

    2004-12-01

    Full Text Available Donax gemmula Morrison, 1971 ocorre em praias arenosas da costa sudeste-sul do Brasil até o Uruguai. Espécimes foram coletados na Praia de Barequeçaba, São Sebastião, Estado de São Paulo, Brasil. O comportamento do animal foi registrado "in situ" e em aquários e a morfologia funcional a partir de espécimes dissecados sob estereomicroscópio; detalhes da anatomia foram obtidos a partir de cortes histológicos. A concha pequena, lisa, subglobosa, e o pé grande, muscular, provido de um par de músculos elevadores bem desenvolvidos, permitem escavação rápida, vital em praias sujeitas à intensa ação de ondas onde a espécie vive. Aparato bissal vestigial ocorre desde a fase juvenil à adulta e este donacídeo de vida livre, infaunal, não migra acompanhando o ritmo das marés. As margens do manto possuem prega mediana duplicada; além de tentáculos captados, as pregas medianas possuem tentáculos sensoriais filiformes, longos, estes últimos restritos à região posterior do animal. A espécie tem hábito alimentar suspensívoro seletivo, o qual é revelado pela presença de ctenídios grandes, completos e homorhábdicos, palpos labiais pequenos e muito seletivos, intestino curto, fracamente sinuoso, separado do saco do estilete cristalino, e tentáculos ramificados formando um crivo em torno da abertura inalante.Donax gemmula Morrison, 1971 is a small bivalve occurring on sandy beaches throughout the Southeastern Brazilian coast to Uruguai. Live specimens were collected from Barequeçaba Beach, São Sebastião, State of São Paulo, Brazil. The animal's behaviour was recorded in situ as well as in aquaria, and its functional morphology registered from specimens dissected under stereomicroscope; details of the anatomy were obtained from histological sections. The minute, smooth subglobose shell, and the large, muscular foot provided with a pair of well-developed elevator muscles allow fast burrowing, vital in the disturbed beach environment where the species lives. A vestigial byssal apparatus is present from juvenile through the adult form and this free-living infaunal donacid does not migrate following the rising and ebbing tides. The mantle margins have the middle fold duplicated; besides captate tentacles, the middle folds bear long, filiform, sensory tentacles, the latter restricted to the rear end of the animal. The presence of complete, large, homorhabdic ctenidia; small but very selective labial palps; short and few convoluted intestine, separated from the style sac; and straining tentacles encircling the inhalant aperture reveal the selective suspension feeding habit of the species.

  17. 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.

  18. Ciclo gonadal del chorito Mytilus chilensis (Bivalvia: Mytilidae en dos localidades del sur de Chile Gonadal cycle of the mussel Mytilus chilensis (Bivalvia: Mytilidae at two localities in southern of Chile

    Directory of Open Access Journals (Sweden)

    Pablo A Oyarzún

    2011-11-01

    Full Text Available Se analizó de forma cualitativa y cuantitativa el ciclo gonadal del bivalvo Mytilus chilensis en las localidades de Chaihuín y bahía Yal, sur de Chile, entre octubre 2007 y junio 2008. Por medio de análisis histológico gonadal se determinaron cuatro estadios gametogénicos y a su vez se estimó en forma cuantitativa, el Volumen de la Fracción Gamética (VFG, el porcentaje de tejido interfolicular y el índice gonadal. El análisis cuantitativo (VFG fue el mejor indicador para determinar los desoves. En los ejemplares de Chaihuín se observaron dos eventos de emisión gamética en forma simultánea en ambos sexos, que ocurrieron en octubre y marzo. Sin embargo, en los ejemplares de bahía Yal se registraron cuatro desoves, principalmente de marzo a junio (otoño, cuando la temperatura del agua disminuyó. Se determinó una escasa relación entre el Índice Gonadosomático (IG y los estadios gametogénicos, al igual que entre el IG y el porcentaje de ovocitos maduros, por ende el IG no sería un indicador apropiado para los desoves en esta especie. Se sugiere la revisión del periodo de veda de Mytilus chilensis (1 noviembre a 31 diciembre, ya que la mayor parte de los individuos de las poblaciones estudiadas, maduran principalmente en octubre. En ambas localidades, el porcentaje de tejido conjuntivo de los especímenes estudiados fluctúo entre 15 y 70% de cobertura gonadal. Los resultados obtenidos mostraron diferencias en los ciclos reproductivos de Mytilus chilensis entre las localidades analizadas, las que se podrían atribuir a diferencias ambientales (e.g. temperatura causadas por el gradiente latitudinal.A qualitative and quantitative analysis was carried out of the gonadal cycle of the bivalve Mytilus chilensis from Chaihuín and Yal bay, southern Chile, between October 2007 and June 2008. Four gametogenic stages were determined using histological analysis of the gonads, and quantitative estimates were made of the Gametic Volume Fraction (VFG, percentage of inter follicular connective tissue, and the Gonadosomatic Index (IG. The quantitative analysis (VFG was the best indicator of spawning. Two spawning events, one in October and one in March, were observed simultaneously in both sexes of mussels from Chaihuín. However, for specimens from bahía Yal, four spawning events were registered, principally from March to June (autumn, when the water temperature decreased. The relationship between the IG and the gametogenic stages was very low, as was that between the IG and the percentage of mature oocytes. Therefore, the IG is not a good indicator of spawning in this species. A re-evaluation of the ban period established for Mytilus chilensis (1 November to 31 December is suggested since most individuals from the populations studied mature mainly in October. At both sites, the percentage of connective tissue for the analyzed mussel individuals ranged between 15 and 70% of gonadal coverage. The results obtained in the present study showed differences in the reproductive cycles of Mytilus chilensis between the sites sampled. These differences could be due to environmental differences (e.g. temperature caused by the latitudinal gradient.

  19. 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...

  20. Non-target trials with Pseudomonas fluorescens strain CL145A, a lethal control agent of dreissenid mussels (Bivalvia: Dreissenidae

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    Daniel P. Molloy

    2013-01-01

    Full Text Available In an effort to develop an efficacious and environmentally safe method for managing zebra mussels (Dreissena polymorpha and quaggamussels (Dreissena rostriformis bugensis, we initiated a research project investigating the potential use of bacteria and their naturalmetabolic products as biocontrol agents. This project resulted in the discovery of an environmental isolate lethal to dreissenid mussels,Pseudomonas fluorescens strain CL145A (Pf-CL145A. In previous published reports we have demonstrated that: 1 Pf-CL145A’s mode ofaction is intoxication (not infection; 2 natural product within ingested bacterial cells lyse digestive tract epithelial cells leading to dreisseniddeath; and 3 high dreissenid kill rates (>90% are achievable following treatment with Pf-CL145A cells, irrespective of whether thebacterial cells are dead or alive. Investigating the environmental safety of Pf-CL145A was also a key element in our research efforts, andherein, we report the results of non-target trials demonstrating Pf-CL145A’s high specificity to dreissenids. These acute toxicity trials weretypically single-dose, short-term (24-72 h exposures to Pf-CL145A cells under aerated conditions at concentrations highly lethal todreissenids (100 or 200 mg/L. These trials produced no evidence of mortality among the ciliate Colpidium colpoda, the cladoceran Daphniamagna, three fish species (Pimephales promelas, Salmo trutta, and Lepomis macrochirus, and seven bivalve species (Mytilus edulis,Pyganodon grandis, Pyganodon cataracta, Lasmigona compressa, Strophitus undulatus, Lampsilis radiata, and Elliptio complanata. Lowmortality (3-27% was recorded in the amphipod Hyalella azteca, but additional trials suggested that most, if not all, of the mortality couldbe attributed to some other unidentified factor (e.g., possibly particle load or a water quality issue rather than Pf-CL145A’s dreissenidkillingnatural product. In terms of potential environmental safety, the results of these invertebrate and vertebrate non-target trials areencouraging, but it would be unrealistic to think that dreissenids are the only aquatic organisms sensitive to Pf-CL145A’s dreissenid-killingnatural product. Additional testing is needed to better define Pf-CL145A’s margin of safety by identifying the sensitivity of other susceptibleorganisms. The results of these non-target safety trials – in combination with equally promising mussel control efficacy data – have now ledto Pf-CL145A’s commercialization under the product name Zequanox®, with dead cells as the product’s active ingredient. The commercialavailability of only dead-cell Zequanox formulations will eliminate the risk of any possible non-target infection by Pf-CL145A, furtherreducing environmental concerns. During the non-target project reported herein, the limited quantities of Pf-CL145A cells that we were ableto culture severely restricted the number and size of our trials. In contrast, the availability of Zequanox will now greatly expand theopportunities for non-target testing. The trials reported herein – exposing non-target organisms under aerated conditions to unformulated,laboratory-cultured cells – clearly point to Pf-CL145A’s potential for high host specificity, but non-target trials with Zequanox – using Pf-CL145A cells cultured, killed, and formulated using industrial-scale protocols – will be even more important as they will define the nontargetsafety limits of the actual commercial products under a wide range of environmental conditions.

  1. 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.

  2. Behavioral responses of Arctica islandica (Bivalvia: Arcticidae) to simulated leakages of carbon dioxide from sub-sea geological storage.

    Science.gov (United States)

    Bamber, Shaw D; Westerlund, Stig

    2016-11-01

    Sub-sea geological storage of carbon dioxide (CO2) provides a viable option for the Carbon Capture and Storage (CCS) approach for reducing atmospheric emissions of this greenhouse gas. Although generally considered to offer a low risk of major leakage, it remains relevant to establish the possible consequences for marine organisms that live in or on sediments overlying these storage areas if such an event may occur. The present study has used a series of laboratory exposures and behavioral bioassays to establish the sensitivity of Arctica islandica to simulated leakages of CO2. This long-lived bivalve mollusc is widely distributed throughout the North Sea, an area where geological storage is currently taking place and where there are plans to expand this operation significantly. A recently published model has predicted a maximum drop of 1.9pH units in seawater at the point source of a substantial escape of CO2 from sub-sea geological storage in this region. Valve movements of A. islandica exposed to reduced pH seawater were recorded continuously using Hall effect proximity sensors. Valve movement regulation is important for optimising the flow of water over the gills, which supplies food and facilitates respiration. A stepwise reduction in seawater pH showed an initial increase in both the rate and extent of valve movements in the majority of individuals tested when pH fell to 6.2 units. Exposing A. islandica to pH 6.2 seawater continuously for seven days resulted in a clear increase in valve movements during the first 40h of exposure, followed by a gradual reduction in activity intensity over the subsequent five days, suggesting acclimation. The ability of both exposed and control bivalves to burrow successfully into sediment on completion of this exposure was very similar. A final exposure trial, testing whether increased valve movements initiated by reduced pH were related to foot extension during attempted burrowing, found no such association. In summary, significant changes in valve behavior did not occur until seawater pH fell to 6.2 units. The response took the form of an increase in valve activity rather than closure. The absence of foot extension coincident with increased valve movements indicates A. islandica were not attempting to burrow, leaving the possibility that valve movements are supporting a respiratory response to hypercapnia. In conclusion, A. islandica appears to be tolerant of reductions in seawater pH equivalent to those predicted for substantial losses of CO2 through leakage from sub-sea geological storage.

  3. Size-selective predation of the catfish Pimelodus pintado (Siluriformes: Pimelodidae on the golden mussel Limnoperna fortunei (Bivalvia: Mytilidae

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    João P. Vieira

    2013-02-01

    Full Text Available This paper describes the size-selective predation on Limnoperna fortunei (Dunker, 1857 by Pimelodus pintado (Azpelicueta, Lundberg & Loureiro, 2008 from the time it arrived at the Mirim Lagoon basin (2005. Sampling was carried out using bottom trawl in depths of 3-6 m, from January to November 2005, and from October to November 2008. Pimelodus pintado began to prey upon L. fortunei soon after its arrival (austral spring of 2005. On the spring of 2008, L. fortunei was found to be the most important food item of P. pintado. The variation in length of the mussels (0.7-3.2 cm, with a mode of 1.3 cm indicates that the species is now fully established in the system. Our data indicates that large individuals of P. pintado incorporate more mussels in their diets than small individuals. However, regardless of their size, P. pintado individuals predate only on small (<1.4 cm representatives of L. fortunei. This prey size corresponds to a phase when the mussel is more mobile and readily available for fish. Larger, more aggregated prey groups that are attached to hard substrates are avoided by fish predators.

  4. Search effort and imperfect detection: Influence on timed-search mussel (Bivalvia: Unionidae surveys in Canadian rivers

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    Reid S. M.

    2016-01-01

    Full Text Available Inventories and population monitoring are essential activities supporting the conservation of freshwater mussel diversity in Canadian rivers. Despite widespread use of timed-search methods to survey river mussels, the relationship between species detection and search effort has received limited study. In this study, repeat-sampling data from 54 Ontario river sites were used to estimate: (1 species detection probabilities; (2 the number of sampling events required to confidently detect species; and, (3 the power of timed-search surveys to detect future distribution declines. Mussels were collected using visual and tactile methods, and collection data were recorded separately for each 1.5 h of search time (up to 4.5 h. Thirteen species were collected; including two endangered species (Rainbow Villosa iris and Eastern Pondmussel Ligumia nasuta. In all cases, species detection was imperfect. However, detection probabilities (p for most species were high (>0.69. Two repeat 4.5 h surveys are required to confidently assess whether most (83% species are present at a site. Search effort had a positive effect on estimates of species richness, detection probability and site occupancy, and the power to detect future distribution declines. At all levels of sampling effort, detection probability and site occupancy estimates were positively correlated to mussel abundance.

  5. First Indonesian record of Fungiacava eilatensis Goreau et al., 1968 (Bivalvia: Mytilidae), endosymbiont of Fungia spp. (Scleractinia: Fungiidae)

    NARCIS (Netherlands)

    Hoeksema, B.W.; Achituv, Y.

    1993-01-01

    The mytilid bivalve Fungiacava eilatensis Goreau, Goreau, Neumann & Yonge, 1968, previously mistakenly referred to as F. eilatensis Soot-Ryen, 1969, is reported for the first time from Indonesia. It lives as an obligate endosymbiont of mushroom corals, particulary Fungia spp., reef-dwelling corals r

  6. Occurrence of the invasive species Corbicula fluminea (Bivalvia, Corbiculidae) in the Sapucaí River (São Paulo, Brazil)

    OpenAIRE

    Vianna, Marina Peixoto; Avelar, Wagner Eustáquio Paiva

    2010-01-01

    Biological invasions are gaining increasing importance due to the ecological damage and economic impacts caused by the invaders. Corbicula fluminea (Müller, 1774) is an invasive exotic bivalve introduced into Brazil in the 1970's, and it has colonized the major rivers of the south and southeast. This species, owing to its adaptations to the environment, speed of colonization and reproductive success among others parameters, quickly occupies the substrates preferred by the natives. The pr...

  7. Low Genetic Diversity and High Invasion Success of Corbicula fluminea (Bivalvia, Corbiculidae) (Müller, 1774) in Portugal

    Science.gov (United States)

    Gomes, Cidália; Sousa, Ronaldo; Mendes, Tito; Borges, Rui; Vilares, Pedro; Vasconcelos, Vitor; Guilhermino, Lúcia; Antunes, Agostinho

    2016-01-01

    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. PMID:27391333

  8. Composición bioquímica de la carne de Polymesoda radiata (Bivalvia: Corbiculidae) en Costa Rica

    OpenAIRE

    Ruiz Campos, Eleazar; Cabrera Peña, Jorge; Cruz, Rafael A; Palacios, José A

    2015-01-01

    Se determinó la composición bioquímica y el indice de condición de la almeja verde (Polymesoda radiata) en el río Bebedero, Guanacaste, Costa Rica, entre agosto de 1992 y julio de 1993. El peso promedio de carne fresca fue de 12.53 ± 3.78 % , con un valor promedio de humedad de 90.10 ± 2.14 % . El promedio de los componentes en base seca fue proteínas 78.29 ± 2.15, Iípidos 9.52 ±1 %, carbohidratos 5.78 ± 2.5 % y cenizas 6.43 ± 2.1 %. El promedio del índice de condición para la población fue d...

  9. Efeitos de microplástico na fisiologia do mexilhão Perna perna (Bivalvia: Mytilidae)

    OpenAIRE

    Liv Goldstein Ascer

    2015-01-01

    Dentre as diferentes poluições presentes nos oceanos, o plástico é provavelmente, aquele que leva aos maiores impactos ambientais, sendo encontrado de praias e manguezais à giros no meio dos oceanos. Os macroplásticos, cujo tamanho é superior a 5mm, são maiores em volume e provocam um impacto socioambiental importante, porém os microplásticos, fragmentos menores que 5mm, estão em maior quantidade e podem provocar danos em organismos marinhos filtradores como mexilhões e ostras. Apesar da sua ...

  10. Mitogenomics of southern hemisphere blue mussels (Bivalvia: Pteriomorphia): Insights into the evolutionary characteristics of the Mytilus edulis complex

    Science.gov (United States)

    Gaitán-Espitia, Juan Diego; Quintero-Galvis, Julian F.; Mesas, Andres; D’Elía, Guillermo

    2016-01-01

    Marine blue mussels (Mytilus spp.) are widespread species that exhibit an antitropical distribution with five species occurring in the Northern Hemisphere (M. trossulus, M. edulis, M. galloprovincialis, M. californianus and M. coruscus) and three in the Southern Hemisphere (M. galloprovincialis, M. chilensis and M. platensis). Species limits in this group remain controversial, in particular for those forms that live in South America. Here we investigated structural characteristics of marine mussels mitogenomes, based on published F mtDNA sequences of Northern Hemisphere species and two newly sequenced South American genomes, one from the Atlantic M. platensis and another from the Pacific M. chilensis. These mitogenomes exhibited similar architecture to those of other genomes of Mytilus, including the presence of the Atp8 gene, which is missing in most of the other bivalves. Our evolutionary analysis of mitochondrial genes indicates that purifying selection is the predominant force shaping the evolution of the coding genes. Results of our phylogenetic analyses supported the monophyly of Pteriomorphia and fully resolved the phylogenetic relationships among its five orders. Finally, the low genetic divergence of specimens assigned to M. chilensis and M. platensis suggests that these South American marine mussels represent conspecific variants rather than distinct species. PMID:27241855

  11. Assessment of heavy metal accumulation in Mytilus galloprovincialis and Tapes decussatus (Bivalvia distributed in the Homa Lagoon (Izmir Bay.

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    Mustafa Bilgin

    2015-03-01

    Full Text Available Bu çalışma kapsamında Gediz Deltasında yer alan Kırdeniz, Homa ve Çilazmak Dalyanları ile Çamaltı Tuzlası kıyılarından alınan yüzey sedimentlerinde ağır metal konsantrasyonları saptanmıştır. Zenginleşme faktörleri(EF hesap edilerek, metal kirliliğinin muhtemel kaynakları belirlenmiş ve sediment kalite kriterlerine (SQG göre sediment kalitesi ve kirlilik düzeyleri tespit edilmiştir. En yüksek metal konsantrasyonları, Çamlatı Tuzlası, Kırdeniz ve Çilazmak Dalyanlarında saptanmıştır. Tüm çalışma bölgesi için Pb, Cr, Ni’ nin yansıra özellikle Çilazmak ve Çamaltı Tuzlası alanlarında Hg kirlilikleri antropojenik kaynaklıdır. Çalışma alanının tümünde Ni konsantrasyonları PEL değerinin, Pb ve Cr seviyeleri ise TEL değerinin üstündedir. SOQ kriterlerine göre tüm istasyonlar Ni ve Cr açısından aşırı kirli; Pb için ise kısmen kirli olarak sınıflandırılmıştır. En yüksek kirlilik dereceleri Kırdeniz ve Çilazmak Dalyanlarında tespit edilmiştir.

  12. A new species of living glass-scallop, genus Similipecten (Bivalvia, Propeamussiidae), from the Bahama Islands (West Indies)

    NARCIS (Netherlands)

    Dijkstra, H.H.

    2002-01-01

    Introduction Redfern described and figured a propeamussiid species (as Cyclopecten sp.) from the Bahama Islands, which he compared with Cyclopecten nanus Verril & Bush in Verrill, 1897,known from the sub-tropical and tropical western Atlantic. In fact, both species are more morphologically related t

  13. Population biology and secondary production of the stout razor clam Tagelus plebeius (Bivalvia, Solecurtidae on a sandflat in southeastern Brazil

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    Jolnnye R. Abrahão

    2010-02-01

    Full Text Available The population biology and production of the stout razor clam Tagelus plebeius Lightfoot, 1786 were investigated on an intertidal sandflat on the southeast coast of Brazil (Enseada Beach, São Sebastião, state of São Paulo between April 1997 and April 1998. Two rectangular sites of 50 X 10 m parallel to the waterline were established, site A (upper intertidal level and site B (middle intertidal level, where the samples were taken in an 0.5 x 0.5 m quadrat. High abundances were recorded in winter and spring, with no significant differences between the sites. The high bivalve abundances were related to the presence of very fine homogeneous sediment with low salinities. Tagelus plebeius had negative allometric growth, characteristic of deep burrowers for the relationships DM/SL and AFDM/SL. Parameters of the modified von Bertalanffy growth function were: L∞ = 67.01 mm, K = 1.73 year-1, t0 = -0.11 year, C = 0.43, WP = 0.96. The instantaneous mortality (Z was 3.12 year-1, relatively high in comparison to other tropical bivalve populations. Secondary production was 1.53 g AFDM m-2 year-1, with a P/B ratio reaching 1.37 year-1. This high turnover ratio (P/B was related to a rapid population replacement, connected with the short life span and high mortality of the species.

  14. Golden mussel Limnoperna fortunei (Bivalvia: Mytilidae distribution in the main hydrographical basins of Uruguay: update and predictions

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    Ernesto Brugnoli

    2005-06-01

    Full Text Available Limnoperna fortunei, an Asiatic rivers bivalve has become a worldwide problematic invasive species causing several water quality and macrofouling problems. In the Neotropical region it was first recorded in 1991 in the Río de la Plata coast, Buenos Aires province. Since this, it showed a quick upstream invasion into the principals aquatic systems of the Plata Basin. Nevertheless, there is not a study about its invasion and distribution process in aquatic systems of Uruguay. We describe the new records of Limnoperna fortunei in Uruguayan coast of Río de la Plata, Santa Lucía, Negro and Uruguay Rivers. With these results we aim to estimate its distributional limits for Uruguay main hydrographical basins. We also deal with the role of salinity as the main abiotic factor in limiting the east distribution of this mussel in Uruguayan coast of Río de la Plata and as a potential determinant of the "new" colonization on the Atlantic and the Merín Lagoon Basins. Its presence in the ecosystems not only can cause changes at the ecosystem level but also endanger the associated community, favoring the displacement and the disappearance of endemic species.Limnoperna fortunei, é um bivalve invasor de origem asiática que ocasiona problemas na qualidade d'água e poluição em diversas parte do mundo. Na região Neotropical foi registrado pela primeira vez na costa do Rio de la Plata, província de Buenos Aires. Desde então mostrou uma rápida invasão águas acima nos principais sistemas aquáticos da Bacia del Plata. Porém, ainda não existem estudos acerca do processo de invasão e distribuição nos ecossistemas aquáticos do Uruguai. O presente trabalho descreve os novos registros de Limnoperna fortunei na costa uruguaia do Rio de la Plata e dos Rios Santa Lucia e Uruguai. Os presentes resultados permitem avaliar seus limites de distribuição nas principais bacias hidrográficas do Uruguai. Discute-se o papel da salinidade como o principal fator abiótico limitante da distribuição deste mexilhão dourado na costa Uruguaia do Rio de la Plata e como potencial determinante na nova colonização nas bacias hidrográficas das Lagoas Merin e Atlântica. Sua presença nos ecossistemas aquáticos pode ocasionar não apenas mudanças a nível do ecossistema, mas também pôr em perigo as comunidades associadas favorecendo o desaparecimento das espécies endêmicas.

  15. 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.)

  16. Monitoring invasive quagga mussels, Dreissena rostriformis bugensis (Bivalvia: Dreissenidae, and other benthic organisms in a western US aqueduct

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    S. Mark Nelson

    2013-01-01

    Full Text Available A quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897 invasion of an aqueduct in Arizona was monitored from 2007 – 2011using colonization substrates. As numbers increased, a filtering-collector caddisfly (Smicridea fasciatella McLachlan, 1871 declinedsignificantly in abundance. After two years of colonization, freshwater sponges were detected and associated with a decline in D. r. bugensisnumbers. Periphyton biomass increased considerably on substrates; perhaps partially, the result of decreased turbidity. Aqueduct biofoulerscould have major impacts on costs associated with aqueduct maintenance. From an operations viewpoint, mussels are undesirable due to flowrestriction associated with increased friction. Augmented sponge and periphyton biomass may also influence aqueduct operations andefficiencies.

  17. New records of Fungiacava eilatensis Goreau et al., 1968 (Bivalvia, Mytilidae) boring into Indonesian mushroom corals (Scleractinia, Fungiidae)

    NARCIS (Netherlands)

    Hoeksema, B.W.; Kleemann, K.

    2002-01-01

    New observations on endoparasites in mushroom corals at South Sulawesi and Bali resulted in eight coral host records of the mytilid bivalve Fungiacava eilatensis Goreau et al., 1968, bringing the total to 14. The host corals were observed in various habitats, most frequently on sandy substrates. The

  18. Comparative efficiency in the culture of the scallop Nodipecten nodosus (Linnaeus, 1758 (Bivalvia: Pectinidae at different densities and depths

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    Jaime Fernando Ferreira

    2006-06-01

    Full Text Available Different methods of growth of scallops are used which employ different densities and depths in several parts of the globe. These methods present different efficiencies depending on the location, the species, and the stage of cultivation. In order to establish a recommended growth system for Nodipecten nodosus, survival and growth rates were compared for two densities (50 and 100 seeds per lanternet floor and three depths (4, 9 and 14 m, evaluating the physico-chemical and environmental parameters of the growing-out area. The seeds had an initial length of 23.93mm ± 2.39, and at the end of the experiment, the highest average was approximately 47.97mm ± 4.54 at a depth of 4m, in low density. After 4 month’s experimentation, it was observed that the survival did not differ according to the tested densities and depths (P>0.05. However, the final growth was significantly greater at 4m in low density, when compared to the final growth at a depth of 14m in high density. It was concluded that the most viable culture method for N. nodosus was the one close to the surface (4m, where organic matter presented the lowest rate, and chlorophyll a and final growth rates were found to be the highest, consequently classifying this depth as the most viable during the intermediate culture.

  19. Seasonal abundance of the shipworm Neoteredo reynei (Bivalvia, Teredinidae in mangrove driftwood from a northern Brazilian beach

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    Carlos S. Filho

    2008-03-01

    Full Text Available Shipworms are important decomposers of wood, especially in mangrove forests where productivity is high. However, little emphasis has been given to the activity of shipworms in relation to the export of nutrients from mangroves to adjacent coastal areas. As a first step to obtaining such information, the frequency of colonized mangrove driftwood as well as shipworm density and length were studied by collecting washed up logs during a year at Ajuruteua beach, state of Pará, northern Brazil. A single species, Neoteredo reynei (Bartsch, 1920, was found colonizing driftwood. Although large colonized logs were most common on the beach, shipworm density was higher in small logs, especially during the dry season. In general, however, density was higher during the wet season (January to April and lowest in July. Overall shipworm mean length was 9.66cm. In large logs, mean length increased between the wet and dry seasons. However, there was no difference in length among log size categories. Mean shipworm length was similar throughout most of the year but tended to be greater in July. Although salinity varied between 10.9 and 40 during the year, no relationship was found between salinity and density or length. The results suggest that shipworm activity in driftwood logs is relatively constant throughout the year. Increased air humidity and rainfall may promote survival during the wet season. Large logs may take longer to colonize and thus have lower densities than small ones which are scarce probably because they are destroyed rapidly by shipworm activity. However, data on the disintegration of logs would be necessary to test this hypothesis. Larger size of shipworms in the dry season may be related to growth after an earlier recruitment period. Shipworms in large logs during the dry season may be better protected from dessication and high temperatures by the insulating properties of the larger volume of wood.

  20. Lithophaga (Bivalvia, Mytilidae), including a new species, boring into mushroom corals (Scleractinia, Fungiidae) of South Sulawesi, Indonesia

    NARCIS (Netherlands)

    Kleemann, K.; Hoeksema, B.W.

    2002-01-01

    Bivalve species of the mytilid genus Lithophaga, including a new one, are recorded from Indonesian mushroom corals (Scleractinia, Fungiidae). True associations with live hosts including L. laevigata, L. lessepsiana, L. lima, L. punctata spec. nov., and L. simplex, while specimens of L. malaccana and

  1. A new species of the genus Policordia (Bivalvia, Verticordioidea, Lyonsiellidae from off the coast of southern California

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    Lyudmila A. Safonova

    2016-10-01

    Full Text Available A new species, Policordia hispida, is described and compared with three similar species: P. densicostata (Locard, 1898; P. pilula (Pelseneer, 1911 and a yet un-described species, Policordia sp. (= P. pilula sensu Ivanova, 1977 not Pelseneer, 1911. This is a first record for the genus in the Californian province.

  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 Pacific clam Nutricola tantilla (Bivalvia:Veneridae) has separate sexes and makes use of brood protection and sperm storage

    DEFF Research Database (Denmark)

    Lützen, Jørgen; Jespersen, Åse; Russell, Michael P.

    2015-01-01

    Et morfologisk studie af en NW Amerikansk blødbunds-musling Nutricola tantilla viste at den er særkønnet og ikke, som tidligere rapporteret, protandrisk hermafrodit. Vi baserer denne konklusion på at små hanner har højt specialiserede kirtelholdige spermiodukter, mens større hunner har simple ovi...

  4. 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.

  5. 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.

  6. Pectinoidea (Bivalvia: Propeamussiidae, Entoliidae and Pectinidae) from the Tarava Seamounts, Society Islands and the Tuamotu Archipelago (French Polynesia)

    NARCIS (Netherlands)

    Dijkstra, H.H.; Maestrati, P.

    2013-01-01

    Eighteen species of Pectinoidea (six Propeamussiidae Abbott, 1954, one Entoliidae Teppner, 1922, eleven Pectinidae Rafinesque, 1815) are listed from the Tarava Seamounts, Society Islands and Tuamotu Archipelago, French Polynesia. Four Propeamussiidae species (Parvamussium lamellatum n. sp., Parvamus

  7. Biochemical and fatty acid composition of Arca noae (Bivalvia: Arcidae from the Mali Ston Bay, Adriatic Sea

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    I. DUPCIC RADIC

    2014-09-01

    Full Text Available Biochemical and fatty acid composition of the bivalve Arca noae were investigated in the Mali Ston Bay in relation to environmental conditions. Sampling was carried out monthly, from December 2001 to November 2002. Wet shellfish meat consists on average of 77.61% water and 22.39% dry matter, while dry shellfish meat consists on average of 89.04% organic and 10.96% inorganic matter. PCA analysis identified temperature, nitrate, silicate, MICRO, Chl a and salinity as the most important environmental factors influencing biochemical composition of A. noae. An increase of dry weight content of A. noae was observed during the spring when both the sea temperature and food supply increased rapidly. Contents of protein (54.39-62.06% of dry weight, carbohydrate (4.13-8.07% of dry weight and lipid (3.46-8.58% of dry weight varied significantly during the year. Protein and lipid level reached the maximum value in June. The fatty acid profiles of total lipids extracted from A. noae showed high level of unsaturation (UNS/SAT 1.9-3.4. Total polyunsaturated fatty acids (PUFA represented the majority of total fatty acids (40.3-59.9% of total fatty acids and the most abundant were eicosapentaenoic (20:5n-3 and docosahexaenoic (22:6n-3 acid. n-3/n-6 PUFA ratio value varied between 2.1 and 5.0 and was the highest during the spring (April to June. Due to their low lipid and high percentages of healthy polyunsaturated fatty acids A. noae can be evaluated as a quality seafood product. The most suitable period of the year for its consumption is in the spring when it reaches its highest nutritional values.

  8. SEM observation of structural (non-mineralogical) alteration inside the previously crystallized nacreous layer of Crenomytilus grayanus (Bivalvia: Mytilidae).

    Science.gov (United States)

    Zuykov, Michael; Pelletier, Emilien; Kolyuchkina, Galina

    2013-01-01

    A microstructural and mineralogical study shows the transition of aragonitic nacreous tablets to aragonitic prisms inside previously secreted nacre, i.e. without contact with the mantle or extrapallial fluid, in a field-collected mytilid bivalve Crenomytilus grayanus (D.). The intermediate zone between nacre and new prisms is represented by nacre tablets "stuck together" or by disordered calcium carbonate material. The modified nacre forms aragonitic lenses of prisms (ALPs). These lenses may reach 500 μm in thickness below the tunnels excavated by the shell borers. ALPs are similar to myostracal prisms in mineralogy, morphology, and orientation, but differ from those in the outer shell layer. The process of ALPs formation is different to that of normal shell formation (e.g. nacre-prisms transition between prismatic and nacreous layers), remote biomineralization, extra shell thickening, as well as, shell repair, erosion, deformation or disease. Response to shell excavation by boring organisms is discussed as the reason for the appearance of ALPs.

  9. Frequency, Magnitude, and Possible Causes of Stranding and Mass-Mortality Events of the Beach Clam Tivela mactroides (Bivalvia: Veneridae).

    Science.gov (United States)

    Turra, Alexander; Pombo, Maíra; Petracco, Marcelo; Siegle, Eduardo; Fonseca, Mariana; Denadai, Márcia R

    2016-01-01

    Stranding combined with mass-mortality events of sandy-beach organisms is a frequent but little-understood phenomenon, which is generally studied based on discrete episodes. The frequency, magnitude, and possible causes of stranding and mass-mortality events of the trigonal clam Tivela mactroides were assessed based on censuses of stranded individuals, every four days from September 2007 through December 2008, in Caraguatatuba Bay, southeastern Brazil. Stranded clams were classified as dying (closed valves did not open when forced) or dead (closed valves were easily opened). Information on wave parameters and the living intertidal clam population was used to assess possible causes of stranding. This fine-scale monitoring showed that stranding occurred widely along the shore and year-round, with peaks interspersed with periods of low or no mortality. Dead clams showed higher mean density than dying individuals, but a lower mean shell length, attributed to a higher tolerance to desiccation of larger individuals. Wave height had a significant negative relationship to the density of dying individuals, presumed to be due to the accretive nature of low-energy waves: when digging out, clams would be more prone to be carried upward and unable to return; while larger waves, breaking farther from the beach and with a stronger backwash, would prevent stranding in the uppermost areas. This ecological finding highlights the need for refined temporal studies on mortality events, in order to understand them more clearly. Last, the similar size structure of stranded clams and the living population indicated that the stranded individuals are from the intertidal or shallow subtidal zone, and reinforces the ecological and behavioral components of this process, which have important ecological and socioeconomic implications for the management of this population.

  10. Gametogénesis y desove de chione subrugosa (Wood, 1928 (Bivalvia veneridae en el golfo de Nicoya, Costa Rica.

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    Rafael A Cruz

    2016-03-01

    El índice de condición reflejó las variaciones en la maduración sexual, Ch. subrugosa es un molusco dioico con una producción sexual de 1.4 hembras /1 macho; en ningún caso se encontró evidencia de hermafroditismo. Los picos de desove aparecen en junio-octubre y febrero, épocas caracterizadas por un leve incremento en la temperatura y un fuerte decrecimiento en la salinidad superficial del agua.

  11. Early life history and spatiotemporal changes in distribution of the rediscovered Suwannee moccasinshell Medionidus walkeri (Bivalvia: Unionidae)

    Science.gov (United States)

    Johnson, Nathan A.; Mcleod, John; Holcomb, Jordan; Rowe, Matthew T.; Williams, James D.

    2016-01-01

    Accurate distribution data are critical to the development of conservation and management strategies for imperiled species, particularly for narrow endemics with life history traits that make them vulnerable to extinction. Medionidus walkeri is a rare freshwater mussel endemic to the Suwannee River Basin in southeastern North America. This species was rediscovered in 2012 after a 16-year hiatus between collections and is currently proposed for listing under the Endangered Species Act. Our study fills knowledge gaps regarding changes in distribution and early life history requirements of M. walkeri. Spatiotemporal changes in M. walkeri distribution were displayed using a conservation status assessment map incorporating metadata from 98 historical (1916–1999) and 401 recent (2000–2015) site surveys from museums and field notes representing records for 312 specimens. Recent surveys detected M. walkeri only in the middle Suwannee subbasin (n = 86, 22 locations) and lower Santa Fe subbasin (n = 2, 2 locations), and it appears the species may be extirpated from 67% of historically occupied 10-digit HUCs. In our laboratory experiments, M. walkeri successfully metamorphosed onPercina nigrofasciata (56.2% ± 8.9) and Etheostoma edwini (16.1% ± 7.9) but not on Trinectes maculatus, Lepomis marginatus, Notropis texanus, Noturus leptacanthus, Etheostoma fusiforme, orGambusia holbrooki. We characterize M. walkeri as a lure-displaying host fish specialist and a long-term brooder (bradytictic), gravid from fall to early summer of the following year. The early life history and distribution data presented here provide the baseline framework for listing decisions and future efforts to conserve and recover the species.

  12. Bad taxonomy can kill : molecular reevaluation of Unio mancus Lamarck, 1819 (Bivalvia : Unionidae and its accepted subspecies

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    Prie V.

    2012-07-01

    Full Text Available The conservation status of European unionid species rests on the scientific knowledge of the 1980s, before the current revival of taxonomic reappraisals based on molecular characters. The taxonomic status of Unio mancus Lamarck, 1819, superficially similar to Unio pictorum (Linnaeus, 1758 and often synonymized with it, is re-evaluated based on a random sample of major French drainages and a systematic sample of historical type localities. We confirm the validity of U. mancus as a distinct species occurring in France and Spain, where it is structured into three geographical units here ranked as subspecies: U. m. mancus [Atlantic drainages, eastern Pyrenees, Spanish Mediterranean drainages], U. m. turtonii Payraudeau, 1826 [coastal drainages East of the Rhône and Corsica] and U. m. requienii Michaud, 1831 [Seine, Saône-Rhône, and coastal drainages West of the Rhône]. Many populations of Unio mancus have been extirpated during the 20th century and the remaining populations continue to be under pressure; U. mancus satisfies the criteria to be listed as «Endangered» in the IUCN Red List.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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

  1. 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.

  2. 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 ...

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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.

  7. 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.

  8. Frequency, Magnitude, and Possible Causes of Stranding and Mass-Mortality Events of the Beach Clam Tivela mactroides (Bivalvia: Veneridae)

    Science.gov (United States)

    Turra, Alexander; Pombo, Maíra; Petracco, Marcelo; Siegle, Eduardo; Fonseca, Mariana; Denadai, Márcia R.

    2016-01-01

    Stranding combined with mass-mortality events of sandy-beach organisms is a frequent but little-understood phenomenon, which is generally studied based on discrete episodes. The frequency, magnitude, and possible causes of stranding and mass-mortality events of the trigonal clam Tivela mactroides were assessed based on censuses of stranded individuals, every four days from September 2007 through December 2008, in Caraguatatuba Bay, southeastern Brazil. Stranded clams were classified as dying (closed valves did not open when forced) or dead (closed valves were easily opened). Information on wave parameters and the living intertidal clam population was used to assess possible causes of stranding. This fine-scale monitoring showed that stranding occurred widely along the shore and year-round, with peaks interspersed with periods of low or no mortality. Dead clams showed higher mean density than dying individuals, but a lower mean shell length, attributed to a higher tolerance to desiccation of larger individuals. Wave height had a significant negative relationship to the density of dying individuals, presumed to be due to the accretive nature of low-energy waves: when digging out, clams would be more prone to be carried upward and unable to return; while larger waves, breaking farther from the beach and with a stronger backwash, would prevent stranding in the uppermost areas. This ecological finding highlights the need for refined temporal studies on mortality events, in order to understand them more clearly. Last, the similar size structure of stranded clams and the living population indicated that the stranded individuals are from the intertidal or shallow subtidal zone, and reinforces the ecological and behavioral components of this process, which have important ecological and socioeconomic implications for the management of this population. PMID:26745804

  9. [Seasonal variation in proximate composition of mussels Tagelus peruvianus (Bivalvia: Solecurtidae) from the Gulf of Nicoya, Puntarenas, Costa Rica].

    Science.gov (United States)

    Fonseca Rodríguez, Cristian; Marín-Vindas, Carolina; Chavarría-Solera, Fabián; Agüero Pedro, Toledo

    2011-12-01

    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 decreased, indicative of two spawning periods and one gonadal resting phase. Soft tissues were respectively characterized by protein (61.9 +/- 4.3%), carbohydrates (15.7 +/- 2.4%), ash (14.0 +/- 1.9%) and lipids (8.5 +/- 1.7%). The average caloric content was 5.0 +/- 0.1 kcal/g. The results showed that the decrease in protein and fat percentage, and calories content, occurred during the spawning seasons. We suggest that T. peruvianus has an optimal nutritional value for human consumption because of the low-fat and moderate protein content.

  10. Strict sex-specific mtDNA segregation in the germ line of the DUI species Venerupis philippinarum (Bivalvia: Veneridae).

    Science.gov (United States)

    Ghiselli, Fabrizio; Milani, Liliana; Passamonti, Marco

    2011-02-01

    Doubly Uniparental Inheritance (DUI) is one of the most striking exceptions to the common rule of standard maternal inheritance of metazoan mitochondria. In DUI, two mitochondrial genomes are present, showing different transmission routes, one through eggs (F-type) and the other through sperm (M-type). In this paper, we report results from a multiplex real-time quantitative polymerase chain reaction analysis on the Manila clam Venerupis philippinarum (formerly Tapes philippinarum). We quantified M- and F-types in somatic tissues, gonads, and gametes. Nuclear and external reference sequences were used, and the whole experimental process was designed to avoid any possible cross-contamination. In most male somatic tissues, the M-type is largely predominant: This suggests that the processes separating sex-linked mitochondrial DNAs (mtDNAs) in somatic tissues are less precise than in other DUI species. In the germ line, we evidenced a strict sex-specific mtDNA segregation because both sperm and eggs do carry exclusively M- and F-types, respectively, an observation that is in contrast with a previous analysis on Mytilus galloprovincialis. More precisely, whereas two mtDNAs are present in the whole gonad, only the sex-specific one is detected in gametes. Because of this, we propose that the mtDNA transmission is achieved through a three-checkpoint process in V. philippinarum. The cytological mechanisms of male mitochondria segregation in males and degradation in females during the embryo development (here named Checkpoint #1 and Checkpoint #2) are already well known for DUI species; a Checkpoint #3 would act when primordial germ cells (PGCs) are first formed and would work in both males and females. We believe that Checkpoint #3 is a mere variation of the "mitochondrial bottleneck" in species with standard maternal inheritance, established when their PGCs separate during embryo cleavage.

  11. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  13. [Sexual cycle of Cerastoderma glaucum Poiret, 1798 (Bivalvia, Eulamellibranchia, Cardiidae) in Lake Tunis and in the Bou Grara sea (Tunisia)].

    Science.gov (United States)

    Zaouali, J

    1980-09-01

    The study of the sexual cycle of Cerastoderma glaucum points out the presence of a very short sexual rest period (from january to march) and of three spawning periods (from may to june, august to september, december to january). If autumn is warm (15 degree C), 80 to 90% of the winter stock is formed by mature individuals.

  14. Distribution, Genetic Characterization, and Life History of the James spinymussel, Pleurobema collina (Bivalvia: Unionidae), in Virginia and North Carolina

    OpenAIRE

    Petty, Melissa A.

    2005-01-01

    Three spined, mussel species occur in the United States along the Atlantic slope; James spinymussel (Pleurobema collina), Tar spinymussel (Elliptio steinstansana), and Altamaha spinymussel (E. spinosa). The James spinymussel was listed as endangered in 1988, and was until recently considered to be endemic to the James River basin (Clarke and Neves 1984; USFWS 1990). Biologists with the North Carolina Department of Transportation (NCDOT) discovered spinymussel populations in the Dan and Mayo...

  15. Functional morphology, biology and sexual strategy of the circumboreal, adventitious crypt-building, Crenella decussata (Bivalvia: Mytiloidea: Crenellidae)

    DEFF Research Database (Denmark)

    Morton, Brian; Dinesen, Grete E.; Ockelmann, Kurt W.

    2016-01-01

    to the prodissoconch stage. Subsequently, these larvae are transferred to the exhalant tube of the crypt wherein they attach by a single fine byssal thread and are further brooded until the crawl-away juvenile stage is attained. Experimental studies of larval behaviour suggest that parental pheromones sustain...... the female/offspring bond. Newly hatched individuals responded to parental exhalant water by actively attaching themselves using a byssal thread. This response persisted for 28 days, but not after 55 days when, we suggest, the pheromonal response ceases and offspring are developed sufficiently to take up...... life in their own nests. Offspring retrieved from parental crypts and fed continuously reached an average shell length of 500 mm after 7.5 months. Brooded offspring thus appear to rely on embryonal energy resources until post-metamorphosis, after which suspension feeding becomes essential for further...

  16. New species and new records of deep-water Pectinoidea (Bivalvia: Propeamussiidae, Entoliidae and Pectinidae) from the South Pacific

    NARCIS (Netherlands)

    Dijkstra, H.H.; Maestrati, P.

    2008-01-01

    Fifty-two deep-water species of Pectinoidea (37 Propeamussiidae, 1 Entoliidae, 14 Pectinidae) are listed from Norfolk Ridge (11 species), Loyalty Islands (4 species), Fiji Islands (30 species), Tonga (26 species), Solomon Islands (26 species) and the Marquesas archipelago (8 species). All species fr

  17. Evolutionary ecology of the Pachydontinae (Bivalvia, Corbulidae) in the Pebas lake/wetland system (Miocene, western Amazonia)

    NARCIS (Netherlands)

    Wesselingh, F.P.

    2006-01-01

    Miocene deposits in western Amazonia and adjacent areas of South America harbour a diverse suite of endemic corbulid bivalves, commonly referred to as Pachydontinae, that show a wide variety of morphologies. Especially in the Miocene Pebas Formation (Peru, Colombia and Brazil), this group diversifie

  18. Differences in sperm ultrastructure between Mytilus chilensis and Mytilus galloprovincialis (Bivalvia, Mytilidae: could be used as a taxonomic trait?

    Directory of Open Access Journals (Sweden)

    Pablo A Oyarzún

    2014-03-01

    Full Text Available The sperm ultrastructure has been used to solve several systematic and phylogenetic problems in marine invertebrates. The sperm ultrastructure of the Chilean mussel Mytilus chilensis and Mytilus galloprovincialis corresponds to the ect-aquasperm type. Sperm from both taxa measured 55-60 μm between head (acrosome + nucleus, midpiece (only 5 mitochondria and the flagellum which in its end piece has a smaller diameter tail. The differences between both taxa are clearly shown, in the structure of the acrosome and nucleus. Therefore, according to our results and those reported in the literature, we indicate that Chilean native mussel sperm is different from other species of the Mytilus complex (M. trossulus, M. galloprovincialis and M. edulis. These differences in sperm ultrastructure found in M. chilensis, are another trait that can be used to validate the taxonomic status of the species. Differences in sperm morphology are related with reproductive isolation, and probably will be useful to understand future data on speciation. Finally, we discussed the finding that Mytilus galloprovincialis sperm from Chile have an acrosome notoriously smaller than those reported for specimens from Europe and Africa, though they have a great similarity with specimens from Japan, as reported in the literature.

  19. Phage particles infecting branchial Rickettsiales-like organisms in banded carpet shell Polititapes virgineus (Bivalvia) from Galicia (NW Spain).

    Science.gov (United States)

    Darriba, S; Ruiz, M; López, C

    2012-09-12

    Basophilic intracellular prokaryotic-like colonies were observed in the gills of banded carpet shell Polititapes virgineus (= Tapes rhomboides) (Linnaeus, 1767) from a natural bed in Galicia (NW Spain). Light microscope observations suggested the presence of 2 types of colonies, but transmission electron microscopy revealed that these were the same Rickettsiales-like colonies, one infected and the other uninfected by phage particles. This is the first report of the presence of phage particles in Rickettsiales-like organisms in the gills of P. virgineus.

  20. Early replication dynamics of sex-linked mitochondrial DNAs in the doubly uniparental inheritance species Ruditapes philippinarum (Bivalvia Veneridae).

    Science.gov (United States)

    Guerra, D; Ghiselli, F; Milani, L; Breton, S; Passamonti, M

    2016-03-01

    Mitochondrial homoplasmy, which is maintained by strictly maternal inheritance and a series of bottlenecks, is thought to be an adaptive condition for metazoans. Doubly uniparental inheritance (DUI) is a unique mode of mitochondrial transmission found in bivalve species, in which two distinct mitochondrial genome (mtDNA) lines are present, one inherited through eggs (F) and one through sperm (M). During development, the two lines segregate in a sex- and tissue-specific manner: females lose M during embryogenesis, whereas males actively segregate it in the germ line. These two pivotal events are still poorly characterized. Here we investigated mtDNA replication dynamics during embryogenesis and pre-adulthood of the venerid Ruditapes philippinarum using real-time quantitative PCR. We found that both mtDNAs do not detectably replicate during early embryogenesis, and that the M line might be lost from females around 24 h of age. A rise in mtDNA copy number was observed before the first reproductive season in both sexes, with the M mitochondrial genome replicating more than the F in males, and we associate these boosts to the early phase of gonad production. As evidence indicates that DUI relies on the same molecular machine of mitochondrial maternal inheritance that is common in most animals, our data are relevant not only to DUI but also to shed light on how differential segregations of mtDNA variants, in the same nuclear background, may be controlled during development.

  1. [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.

  2. 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.

  3. MARMARONIA ANGIOLINII, NEW GENUS AND NEW SPECIES OF BAKEVELLIIDAE (PTERIOIDA, BIVALVIA FROM THE MIDDLE PERMIAN OF CHIOS (GREECE

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    CRISTIANO LARGHI

    2002-11-01

    Full Text Available The Guadalupian (Middle Permian "Gymnocodiacean Limestones" cropping out in the north-eastern part of the Greek island of Chios (eastern Aegean Sea are amongst the most fossiliferous in the western Tethys. They contain rich assemblages of corals, brachiopods, molluscs, calcareous algae, foraminifers and ostracods. Scant attention was given till now to mollusc faunas compared with brachiopods and foraminifers. In the present paper the new genus Marmaronia, with type-species M. angiolinii n. sp., is established to distinguish some bivalves of the Bakevelliidae King, 1850, from the middle Guadalupian successions of the Marmaro locality in Chios Island. M. angiolinii n. gen. n. sp. is strongly inequivalve, with valves differing in convexity, umbo development and ornamentation. The left valve shows a radial furrow running from the anterior part of the umbonal region anteroventrally and is ornamented by strong radial costae; the right valve is ornamented by concentric sculpture and by thin rugae in the first growth stages of the posterior part of the shell. Both valves have a wide posterior wing. Two hypotheses concerning the epi- or endobyssate adaptation of Marmaronia are also discussed briefly in the present paper.   

  4. 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.

  5. Occurrence of the invasive species Corbicula fluminea (Bivalvia, Corbiculidae in the Sapucaí River (São Paulo, Brazil

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    Marina Peixoto Vianna

    2010-09-01

    Full Text Available Biological invasions are gaining increasing importance due to the ecological damage and economic impacts caused by the invaders. Corbicula fluminea (Müller, 1774 is an invasive exotic bivalve introduced into Brazil in the 1970’s, and it has colonized the major rivers of the south and southeast. This species, owing to its adaptations to the environment, speed of colonization and reproductive success among others parameters, quickly occupies the substrates preferred by the natives. The present study registers its occurrence in Sapucaí River, São Paulo State. Samples were taken at two different sites of the river with different substrates, one sandy and another muddy. Granulometric analysis and determination of the organic matter content of the sediment were then conducted. The individuals captured in sandy sediment showed higher densities, higher average size, and therefore higher average biomass.

  6. 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

  7. Devonia perrieri (Malard, 1903 (Bivalvia found in situ on the holothurian Leptosynapta inhaerens (Müller, 1776 in Norway

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    Glenn A. Bristow

    2010-12-01

    Full Text Available 800x600 Normal 0 21 false false false NO-BOK X-NONE X-NONE MicrosoftInternetExplorer4 The ectosymbiotic bivalve, Devonia perrieri, has earlier been found non-associated with its host in grab samples in Western Norway, but has never been found on its purported host, Leptosynapta inhaerens. Here we show it for the first time on its host, Leptosynapta inhaerens, in Norwegian waters. This confirms that the host in Western Norway is same as elsewhere in the bivalve’s distribution area.

  8. Devonia perrieri (Malard, 1903) (Bivalvia) found in situ on the holothurian Leptosynapta inhaerens (Müller, 1776) in Norway

    OpenAIRE

    Bristow, Glenn A; Per Johannessen; Bjørn Berland; Christoffer Schander

    2010-01-01

    The ectosymbiotic bivalve, Devonia perrieri, has earlier been found non-associated with its host in grab samples in Western Norway, but has never been found on its purported host, Leptosynapta inhaerens. Here we show it for the first time on its host, Leptosynapta inhaerens, in Norwegian waters. This confirms that the host in Western Norway is same as elsewhere in the bivalve’s distribution area.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. [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.

  15. A pesca e o manejo do berbigão (Anomalocardia brasiliana (Bivalvia: Veneridae na Reserva Extrativista Marinha do Pirajubaé, SC, Brasil

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    Paulo Ricardo Pezzuto

    2015-08-01

    Full Text Available The Marine Extractive Reserve of Pirajubaé (MER is located in the urban area of Florianópolis city (capital of Santa Catarina State, Southern Brazil, and has the bivalve known as “berbigão” (Anomalocardia brasiliana as its main fishing resource. Based on 100 daily surveys carried out during 2005, this paper describes the berbigão fishery and presents the history of its management. A hand dredge (“gancho” was used by 22 men and four women to catch the berbigão. The fishery is conducted predominantly in the morning and under water depths between 20 and 50 cm. On average, each fisherman swept 469.2 m2 with the dredge and caught 270.5 kilograms of live clams per fishing day, summing up 888.6 t landed in the RESEX along 2005. More than 97% of the individuals in the catch exceeded the minimum legal size (20 mm total length. However, both individual size and total biomass of the stock reduced significantly over time. Most of the catch was processed (i.e. cooked and unshelled and sold to very few buyers. Current management measures include: a maximum number of authorized fisherman; b days of the week and times of the day when the fishery is allowed; c minimum distance between the iron bars in the ganchos’ basket; d minimum legal size; e space-time rotation of fishing areas and, f reporting of daily production data. In spite of the large volume of scientific and traditional knowledge available and the existence of management rules discussed and approved on a participatory system, both the berbigão sustainability and the RESEX as a whole are threatened by administrative, social, economic, environmental and bureaucratic pressures. Neutralize such threats is a key challenge to be faced in this important federal conservation area of Southern Brazil.

  16. Othonella araguaiana (Bivalvia, Megadesmidae from the Corumbataí Formation (Midlle Permian, Eastern Margin of the Paraná Basin: Systematic, Evolutionary and Biostratigraphic Significances

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    Marcello Guimarães Simões

    2010-07-01

    Full Text Available In this study, the occurrence of Othonella araguaiana Mendes, a rare bivalve species is reported for the first time in thePinzonella illusa biozone, Middle Permian Corumbataí Formation, in the State of São Paulo. This species was originallydescribed in coeval rocks of the Estrada Nova Formation (= Corumbataí from the Alto Araguaia and Alto Garças regions,State of Mato Grosso. The specimens of O. araguaiana were found in the base of a bioclastic sandstone bed, a proximaltempestite, in the middle of the Corumbataí Formation, in the city of Rio Claro, São Paulo State. The silicified shells andinternal molds are well preserved, showing impressions of muscle scars and other internal anatomic characters (e.g., hinge,never illustrated by previous authors. In his original description, Mendes (1963 called attention to the similarity betweenO. araguaiana and Terraia aequilateralis, a common veneroid of the Corumbataí Formation. Conversely, Runnegar andNewell (1971 suggested that O. araguaiana belongs to Megadesmidae, being a junior synonym of Plesiocyprinella carinata(the commonest megadesmid of the Passa Dois Group. Our study indicates that O. araguaiana is indeed a megadesmid,but is distinct from the P. carinata. The new occurrence of O. araguaiana demonstrates that a the paleobiogeographicdistribution of this species is wider than previously thought (that it was restricted to the northern part of Paraná Basin,Mato Grosso State; b the molluscan fauna of the Corumbataí Formation (P. illusa biozone in the State of São Paulo ismore diverse and dominated by megadesmids; and c the composition of the molluscan fauna of the Corumbataí Formationin Alto Garças, State of Mato Grosso, is essentially the same as that of the P. illusa biozone of the eastern margin of theParaná Basin.

  17. Inter- and intra-specimen variability masks reliable temperature control on shell Mg/Ca ratios in laboratory and field cultured Mytilus edulis and Pecten maximus (bivalvia

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    H. A. Kennedy

    2008-02-01

    Full Text Available The Mg/Ca ratios of biogenic calcites are commonly seen as a valuable palaeo-proxy for reconstructing past ocean temperatures. The temperature dependence of Mg/Ca ratios in bivalve calcite has been the subject of contradictory observations. The palaeoceanographic use of a geochemical proxy, like Mg/Ca ratios, is dependent on initial, rigorous calibration and validation of relationships between the proxy and the ambient environmental variable to be reconstructed. Shell Mg/Ca ratio data are reported for the calcite of two bivalve species, Mytilus edulis (common mussel and Pecten maximus (king scallop, for the first time grown in laboratory culturing experiments at controlled and constant aquarium seawater temperatures over a range from ~10 to ~20°C. Furthermore, Mg/Ca ratio data of laboratory-grown and field-grown M. edulis specimens were compared. Only a weak, albeit significant, shell Mg/Ca ratio–temperature relationship was observed in the two bivalve species: M. edulis (r2=0.37, pr2=0.50, pP. maximus (r2=0.21, p<0.001, laboratory cultured specimens only. In the two species, shell Mg/Ca ratios also were not found to be controlled by shell growth rate and salinity. Furthermore, measurement of Mg/Ca ratios in the shells of multiple specimens illustrated that a large degree of variability in the measured shell Mg/Ca ratios was significant at the species, inter- and intra-individual shell levels. The study data suggest the use of bivalve calcite Mg/Ca ratios as a reliable, precise and accurate temperature proxy still remains limited, at least in the species studied to date. Such limitations are most likely due to the presence of significant physiological effects on Mg incorporation in bivalve calcite, with such variability differing both within single shells and between shells of the same species that were precipitated under the same ambient conditions.

  18. 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.

  19. Comparative mitogenomic analyses of three scallops (Bivalvia: Pectinidae reveal high level variation of genomic organization and a diversity of transfer RNA gene sets

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    Kong Xiaoyu

    2009-05-01

    Full Text Available Abstract Background It can be seen from the available mollusk mitogenomes that the family Pectinidae exhibits the most variation in genome organization. In this study, comparative mitogenomic analyses were performed for three scallops from the subfamily Chlamydinae (Pectinidae, with the goal of characterizing the degree of variability of mitogenome organization and other characteristics among species from the same subfamily and exploring their possible evolution route. Findings The complete or nearly complete mtDNA sequences of scallop Mimachlamys nobilis (17 935 bp, Mizuhopecten yessoensis (20 964 bp and Chlamys farreri (17 035 bp were determined using long PCR amplification and primer walking sequencing strategy. Highly variable size difference of the three genomes resulted primarily from length and number variations of non-coding regions, and the major difference in gene content of the three scallop species are due to varying tRNA gene sets. Only 21, 16, and 17 tRNA genes were detected in the mitogenomes of M. nobilis, M. yessoensis and C. farreri, respectively. Remarkably, no trnS gene could be identified in any of the three scallops. A newly-detected trnA-like sequence within the mitogenome of M. yessoensis seems to exemplify the functional loss of a tRNA gene, and the duplication of trnD in M. yessoensis raises a fundamental question of whether the retention of the tRNA gene copy of 2-tRNAs is easier than that of 4-tRNAs. Analysis of putative evolutionary pathways of gene rearrangement indicates that transposition of neighboring gene blocks may play an important role in the evolution of mitogenomes in scallops. Parsimonious analysis of the genomic variations implies that the mitogenomes of M. yessoensis and C. farreri are likely to derive independently from a common ancestor that was closely related to M. nobilis. Conclusion Comparative mitogenomic analyses among three species from the subfamily Chlamydinae show that the three genomes exhibit a high level of genomic variation and a diversity of tRNA gene sets, characterized by extensive translocation of genes. These features provide useful clues and information for evolutionary analysis of scallop mitogenomes.

  20. Description and morphology of the “Juan de Fuca vent mussel”, Benthomodiolus erebus sp. n. (Bivalvia, Mytilidae, Bathymodiolinae: “Phylogenetically basal but morphologically advanced”

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    P. Graham Oliver

    2015-08-01

    Full Text Available The Juan de Fuca vent mussel first found in 1990 is formally described as Benthomodiolus erebus sp. n. Comparisons are made with the three other species previously assigned to Benthomodiolus namely B. lignocola, B. geikotsucola and B. abyssicola. The anatomies of all four species are examined and are shown to share the arrangement of pedal and byssus musculature, having largely un-fused mantle margins and a hind gut with a very short loop. The ctenidia were examined using both light and scanning electron microscopy. B. erebus and B. geikotsucola were found to have lamellar filaments with extensive abfrontal expansion and fusion of the ascending and descending arms. In this there is similarity with Bathymodiolus. B. lignocola and B. abyssicola were found to have linear filaments with narrow abfrontal surfaces with little fusion. All four species were shown to have the abfrontal surfaces covered by polygonal cushions of microvilli although these were much less apparent in B. lignocola and B. abyssicola. Although Benthomodiolus was shown by a number of previous studies, using molecular data alone, to be phylogenetically basal to all other Bathymodiolinae the anatomy is highly adapted for chemosymbiosis. Species of Benthomodiolus are found on wood-falls, whale-falls and vent sites and thus mirror the habits of the Bathymodiolus/Idas clade.

  1. Mantle-shell complex reactions elicited by digenean metacercariae in Gaimardia trapesina (Bivalvia: Gaimardiidae) from the Southwestern Atlantic Ocean and Magellan Strait.

    Science.gov (United States)

    Ituarte, C F; Cremonte, F; Deferrari, G

    2001-12-20

    The host response to 3 different larval digeneans affecting Southwestern Atlantic and Magellanic populations of the bivalve Gaimardia trapesina (Lamarck, 1819) (Gaimardiidae) is described. Unencysted metacercariae of 2 species of Gymnophallidae and 1 species of Lepocreadiidae co-exist in the peripheral and general extrapallial spaces. Differences in host responses to stimuli generated by each parasite are described. Infections by Gymnophallidae gen. sp. 1 metacercariae elicit a mantle-shell complex reaction involving both alteration of the mantle epithelium (hyperplasia and metaplasia) and calcium carbonate deposition to form an incomplete calcareous covering of single larvae, comprising individual crystallites in an organic matrix. The calcareous covering covers only the posterior two-thirds of the larval body, having its anterior end free in the extrapallial space, which ensures survival of the larvae. The peculiar features of the host response result from a successful process of adjustment to the parasite's life cycle. Metacercariae of Gymnophallidae gen. sp. 2 occur in one or more small groups of up to 30 individuals, either in the general or in the peripheral extrapallial spaces. The outer mantle reaction includes hyperplasia and metaplasia of the epithelium adjacent to the larvae. Deposition of calcium carbonate did not occur. Lepocreadiidae gen. sp. metacercariae were observed exclusively in the general extrapallial space lodged in single shallow pits whose shape fit the parasite's body shape and size. In simultaneous infections, metacercariae of Gymnophallidae and Lepocreadiidae elicited different responses in an individual, which suggests that each parasitic entity involves a different stimulus to the host.

  2. Survival of glochidial larvae of the freshwater pearl mussel, Margaritifera laevis (Bivalvia: Unionoida), at different temperatures: a comparison between two populations with and without recruitment.

    Science.gov (United States)

    Akiyama, Yoshihiro; Iwakuma, Toshio

    2007-09-01

    The viability of free-living glochidia of the freshwater pearl mussel (Margaritifera laevis) was studied in the laboratory at water temperatures of 10 degrees C, 15 degrees C and 20 degrees C. To obtain glochidia, gravid female mussels were collected from the Chitose River, inhabited by adult and juvenile mussels, and from the Abira River, where only adult mussels were found. Daily survival rates of glochidia from each population at various water temperatures were significantly different, and survival time was longest at the lowest temperature in each population. Maintenance of some field mussel populations might become difficult at higher water temperatures due to the short survival time of glochidia and expected low density of host fish. Daily survival rates of glochidia were compared between the Abira population at 15 degrees C and the Chitose population at 20 degrees C, since these temperatures were close to the mean water temperature during the period of glochidial release in the respective rivers. Daily mean survival rates were significantly different between the Abira population at 15 degrees C and the Chitose population at 20 degrees C. Mean glochidial survival rate for the Chitose population changed from 85.3% to 66.2% from 9 to 13 h, whereas that for the Abira population dropped suddenly from 80.4% to 34.2% from 10 to 14 h after the initiation of experiment. Absence of juveniles in the Abira River might have been caused by the low glochidial viability. Survival times of free-living glochidia in Margaritiferidae tend to be shorter than in other families in Unionoida. A trade-off is suggested between high fertility and low glochidial survival rate in Margaritiferidae.

  3. Updated mitochondrial phylogeny of Pteriomorph and Heterodont Bivalvia, including deep-sea chemosymbiotic Bathymodiolus mussels, vesicomyid clams and the thyasirid clam Conchocele cf. bisecta.

    Science.gov (United States)

    Ozawa, Genki; Shimamura, Shigeru; Takaki, Yoshihiro; Yokobori, Shin-Ichi; Ohara, Yasuhiko; Takishita, Kiyotaka; Maruyama, Tadashi; Fujikura, Katsunori; Yoshida, Takao

    2017-02-01

    The mitochondrial genomes of bivalves have often been used for comparative genomics and for resolving phylogenetic relationships. More than 100 bivalve complete mitochondrial genomes have been sequenced to date. However, few mitochondrial genomes have been reported for deep-sea chemosymbiotic bivalves, which belong to the subclasses Pteriomorphia and Heterodonta. In the present study, we sequenced the mitochondrial genomes of eight deep-sea chemosymbiotic bivalve species: three species of Bathymodiolus mussels (B. japonicus, B. platifrons, and B. septemdierum), four species of vesicomyid clams (Abyssogena mariana, A. phaseoliformis, Isorropodon fossajaponicum, and Phreagena okutanii, all of which were formerly classified in the genus Calyptogena), and one species of thyasirid clam (Conchocele cf. bisecta). With a few exceptions, these mitochondrial genomes contained genes that are typical of metazoans: 13 protein-coding genes, two rRNA genes, and 22 tRNA genes. The major non-coding region with a high A+T content of each genome, which contained tandem repeats and hairpins, was hypothesized to function as a control region. The phylogenetic trees of Pteriomorphia and Heterodonta were reconstructed based on the concatenated sequences of 14 shared genes. Bathymodiolus formed a monophyletic clade with asymbiotic Mytilidae mussels, the vesicomyid clams formed a monophyly that was sister to the Veneridae, and C. cf. bisecta branched basally in the Heterodonta. It is known that the gene orders of mitochondrial genomes vary among bivalves. To examine whether gene order variation exhibits phylogenetic signals, tree topologies based on the minimum number of gene rearrangements were reconstructed for two clades (superfamily Tellinoidea, which includes the Psammobiidae, Semelidae, Solecurtidae, and Tellinidae; and the clade comprising the Myidae, Mactridae, Arcticidae, Vesicomyidae, and Veneridae) with high statistical support in sequence-based phylogenies. The resulting tree topologies were almost identical to those of the sequence-based trees. Our present findings suggest that the evolution of bivalves could be precisely traced back through the analysis of mitochondrial genomes, and that such an analysis could contribute to understanding bivalve evolution and diversity.

  4. Descripción de un nuevo género y dos especies de moluscos, (Bivalvia), para el Pacífico ecuatoriano

    OpenAIRE

    M. Cruz

    1980-01-01

    Se describe un nuevo género :Eucrassinella y dos nuevas especies: Eucrassinella manabiensis y E. aequatorialis; que pertenecen a la familia Crassatellidae. Se agrega un cuadro comparativo de los géneros ya existentes con el nuevo y otro cuadro de las dos especies recién descritas. De los ejemplares recolectados ocho pertenecen a E. manabiensis y uno a E. aequatorialis. Las dos especies fueron encontradas en la plataforma de la provincia de Manabí y la primera también en los sedimentos recient...

  5. 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.

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 五种蚌的形态变异与判别分析%Morphological variations and discriminant analysis of five freshwater unionid species (Bivalvia: Unionidae)

    Institute of Scientific and Technical Information of China (English)

    魏开建; 熊邦喜; 赵小红; 龙良启; 王明学; 王卫民; 赵振山

    2003-01-01

    运用多变量形态度量学方法,采用6个形态性状对褶纹冠蚌、三角帆蚌、圆背角无齿蚌、椭圆背角无齿蚌和球形无齿蚌5种蚌的种间以及地理种群间的形态变异进行了研究.主成分分析构建了2个主成分,第一主成分受4个性状的影响,贡献率为54.17%;第二主成分受1个性状的影响,贡献率为34.08%.主成分分析和聚类分析表明,褶纹冠蚌与三角帆蚌形态相近,椭圆背角无齿蚌与球形无齿蚌外形相似.方差分析和t检验表明,褶纹冠蚌和三角帆蚌的不同地理种群分别表现出形态上的变异.建立了5种蚌的判别函数,三角帆蚌和圆背角无齿蚌的判别准确率均为100%,褶纹冠蚌、椭圆背角无齿蚌和球形无齿蚌的判别准确率依次为98.92%、86.36%和96.88%,总判别准确率为97.83%.

  9. SO-CALLED MIDDLE TRIASSIC "CLARAIA" (BIVALVIA) FROM GUANGXI, SOUTH CHINA%广西中三叠世的"克氏蛤"之订正

    Institute of Scientific and Technical Information of China (English)

    陈金华; 小松俊文

    2002-01-01

    描述报道广西中三叠世地层中一类形态相似于克氏蛤(Claraia)的双壳纲化石,经研究,发现海扇科的关键特征丝梳,认为不属于克氏蛤,而可能是Periclaraia属的一个新种;并初步探讨化石层的生态环境,认为可能是相对隔离的盆地中央区.新种是由海扇类进入隔离环境后经特化形成的;新种与克氏蛤的表面相似性是生活习性的相似性导致的形态趋同现象.

  10. Biomonitoring of Pb and Cd in two impacted watersheds in Southeast Brazil, using the freshwater mussel Anodontites trapesialis (Lamarck, 1819 (Bivalvia : Mycetopodidae as a biological monitor

    Directory of Open Access Journals (Sweden)

    Andréa C. Tomazelli

    2003-12-01

    Full Text Available Studies were carried out to investigate the contamination of Piracicaba and Mogi-Guaçu River basins (São Paulo State, Southeastern, Brazil for heavy metals (Cd and Pb, using the limnic bivalve Anodontites trapesialis as a biological monitor. The results showed that the concentrations of Pb were higher than the control group in both basins, showing the bioavailability of this non-essential element in the basins. The concentrations were higher in the Mogi-Guaçu than in the Piracicaba basin, and in the slightly contaminated sites in both basins. There was no correlation between the degree of human impact and Cd and Pb concentrations, it was not possible to infer about concentrations of these heavy metals in the bivalves based only in a broad evaluation of human impact.O principal objetivo deste estudo foi investigar a contaminação pelos metais pesados Cd e Pb nas bacias dos rios Piracicaba e Mogi-Guaçu (Estado de São Paulo, Brasil, utilizando o bivalve limnico Anodontites trapesialis como indicador biológico. As bacias estudadas apresentam diferentes graus de impacto, sendo a qualidade da água geralmente melhor na bacia do rio Mogi-Guaçu. Os teores de Pb detectados nos bivalves não podem ser considerados críticos, contudo, houve acúmulo em relação ao grupo de controle em ambas as bacias, especialmente na bacia do rio Mogi-Guaçu. As maiores concentrações dos elementos, especialmente Pb, foram observadas nos locais menos poluídos e na bacia menos degradada. Este fato sugere que estas concentrações não estão sendo afetadas apenas pelas atividades antrópicas nas bacias, mas deve-se considerar também fatores que afetem a biodisponibilidade ou fontes específicas e não pontuais.

  11. 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.

  12. 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)

  13. 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.

  14. Optimize Artificial Environment for Live Bivalvia Purification and its effect%活双壳贝类净化人工环境优化设计与效应

    Institute of Scientific and Technical Information of China (English)

    张饮江; 徐文达; 周培根; 沈和定; 吴建中; 王艳

    2007-01-01

    根据双壳贝类生态生理特性,创建由水质处理、O3-UV组合消毒、调温监控等循环水系统组成,有利于双壳贝类张壳、排泄、存活等生理活动,以及避免引起再污染的最佳净化环境,促进贝类净化进程,保证了净化贝类的质量安全;研制高效实用的双壳贝类净化浅水槽模式.结果表明,毛蚶仅在30 h内就达到欧盟规定的净化标准,存活率达91%,快速有效.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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. 

  17. Large-scale mitochondrial COI gene sequence variability reflects the complex colonization history of the invasive soft-shell clam, Mya arenaria (L.) (Bivalvia)

    Science.gov (United States)

    Lasota, Rafal; Pierscieniak, Karolina; Garcia, Pascale; Simon-Bouhet, Benoit; Wolowicz, Maciej

    2016-11-01

    The aim of the study was to determine genetic diversity in the soft-shell clam Mya arenaria on a wide geographical scale using mtDNA COI gene sequences. Low levels of genetic diversity was found, which can most likely be explained by a bottleneck effect during Pleistocene glaciations and/or selection. The geographical genetic structuring of the studied populations was also very low. The star-like phylogeny of the haplotypes indicates a relatively recent, rapid population expansion following the glaciation period and repeated expansion following the founder effect(s) after the initial introduction of the soft-shell clam to Europe. North American populations are characterized by the largest number of haplotypes, including rare ones, as expected for native populations. Because of the founder effect connected with initial and repeated expansion events, European populations have significantly lower numbers of haplotypes in comparison with those of North America. We also observed subtle differentiations among populations from the North and Baltic seas. The recently founded soft-shell clam population in the Black Sea exhibited the highest genetic similarity to Baltic populations, which confirmed the hypothesis that M. arenaria was introduced to the Gulf of Odessa from the Baltic Sea. The most enigmatic results were obtained for populations from the White Sea, which were characterized by high genetic affinity with American populations.

  18. Ascetoaxinus quatsinoensis sp. et gen. nov. (Bivalvia: Thyasiroidea) from Vancouver Island, with notes on Conchocele Gabb, 1866, and Channelaxinus Valentich-Scott & Coan, 2012.

    Science.gov (United States)

    Oliver, P Graham; Frey, Melissa A

    2014-10-02

    Ascetoaxinus quatsinoensis sp. et gen. nov. is described from deep waters off the coast of Vancouver Island, British Columbia, Canada. The shell of this species is quite unusual in that the margin of the lunule is distinctly scalloped, a feature not reported previously for the Thyasiroidea. Further investigation led to the discovery of another similarly scalloped shell, represented by the unique type specimen of Cryptodon ovoideus Dall, 1890, herein re-classified as Ascetoaxinus ovoidea (Dall, 1890). Results obtained from scanning electron microscopy reveal additional anatomical differences, including distinct gill structure, that distinguish A. quatsinoensis from other thyasirids examined. Morphological comparisons of this new species to closely related taxa has resulted in a re-evaluation of the genera Conchocele Gabb, 1866, and Channelaxinus Valentich-Scott and Coan, 2012.

  19. “TUBULAR GILLS” Extreme gill modification in the Thyasiroidea with the description of Ochetoctena tomasi gen. et sp. nov. (Bivalvia: Thyasiroidea

    Directory of Open Access Journals (Sweden)

    Graham Oliver

    2014-10-01

    Full Text Available Three dimensional tubular structures of the ctenidium of some thyasirid bivalves are described for the first time. The classification of the thyasirid gill is modified accordingly into five types based on the number of demibranchs, reflection of the filaments and shape of the filaments, either rod, laminar or tubular. The tubular structure is seen in its most modified form in a chemosymbiotic abyssal species from the south-east Atlantic, which is described here as Ochetoctena tomasi gen et sp. nov.

  20. 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)

  1. An annually-resolved palaeoenvironmental archive for the Eastern Boundary North Atlantic upwelling system: Sclerochronology of Glycymeris glycymeris (Bivalvia) shells from the Iberian shelf

    Science.gov (United States)

    Freitas, Pedro; Monteiro, Carlos; Butler, Paul; Reynolds, David; Richardson, Christopher; Gaspar, Miguel; Scourse, James

    2015-04-01

    The seasonally variable western Iberia upwelling system, albeit placed at a crucial climatic boundary position to record high frequency climate events, lacks well-dated high-resolution records of environmental variability. Bivalve shells provide robust high-resolution archives of oceanographic and climatic variability on timescales of decades to millennia. In particular, the North Atlantic Ocean region has recently seen several noteworthy sclerochronological and geochemical reconstructions based on bivalve shells (mainly Arctica islandica) of high frequency oceanographic and climatic conditions during the last millennium. However, due to the absence of Arctica islandica and similarly long-lived bivalves, sclerochronological palaeoenvironmental studies of southern European coastal shelf seas are scarce. In particular, none of these studies focus on reconstructing the variability of an eastern boundary upwelling system. The relatively long-lived bivalve (>100 years) Glycymeris glycymeris occurs in European and North West African coastal shelf seas and provides a valid annually resolved archive of environmental conditions during growth. Annual growth increment width series from living G. glycymeris shells, collected in 2014 on the western Iberian continental shelf (ca. 35 m water depth), were used to construct a statistically robust, ca. 70-year long absolutely-dated chronology. Sub-annually resolved (11 to 22 samples per year) oxygen stable isotope (δ18Oshell) data covering three years of shell growth, together with the direct evaluation of the time of growth mark deposition in shells collected during the autumn and winter months, were used to constrain the season of growth and to evaluate the seasonal bias of the sea-surface temperature signal preserved in the δ18Oshelldata. The growth increment width and δ18Oshell series, once robustly calibrated against modelled and instrumental oceanographic and climatic series, potentially provide novel insights into the variability of the western Iberia upwelling system and the associated mechanisms. This study was financed and conducted in the frame of the Portuguese Fundação para a Ciência e Tecnologia (FCT) GLYCY Project (contract PTDC/AAC-CLI/118003/2010).

  2. 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.

  3. 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.

  4. 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.

  5. 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 remains uncertain. Neptunea are a predatory snails well represented in the earliest Miocene to Holocene of the northern Pacific Ocean and in the late Pliocene to Holocene of the northern Atlantic. The presence of Neptunea at CSM, if identified properly, gives a maximum age for these deposits of latest Miocene or early Pliocene, after the opening of the Bering Strait, although they could be as young as Holocene.

  6. 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.

  7. 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...

  8. Review of the functional morphology, biology and perturbation impacts on the boreal, habitat-forming horse mussel Modiolus modiolus (Bivalvia: Mytilidae: Modiolinae)

    DEFF Research Database (Denmark)

    Dinesen, Grete E.; Morton, Brian

    2014-01-01

    and overall biology. Modiolus modiolus is a typical epibenthic, suspension-feeding mytilid, albeit with anatomical modifications adapting it to a partially buried, gregarious lifestyle in a stable environment experiencing medium–high energy levels. The juvenile shell is covered partly in byssal setae secreted...... and locality. With age (≥ 20–45 years), shells often become deformed, particularly posteriorly and around the byssal gape, thereby increasing reproductive capacity (gonadal volume) without increasing somatic growth. Information on the biology, reproductive strategy and life history traits of M. modiolus...

  9. [Non detection of enterovirus in the bivalve Anadara tuberculosa (Bivalvia:Arcidae) caused by chemical contamination in the Pacific of Costa Rica].

    Science.gov (United States)

    Libia Herrero, U; Alejandro Palacios, F; Laya Hun, O; Francisco Vega, A

    1999-09-01

    Anadara tuberculosa is one of the most abundant mollusks of commercial importance in Costa Rica. Its habitat water is a potential source of fecal and chemical contamination to humans. We wanted to asses enterovirus, mainly poliovirus and hepatitis A virus and chemicals such as sulphates and nitrates in meat and body fluids. Thirteen samples were taken from four sites in Nicoya Gulf, three sites in the Sierpe-Térraba mangrove (Pacific of Costa Rica) and from five fish markets in San José, the capital of Costa Rica. Samples were tested for 1) fecal coliforms (Most Probable Number/100 ml), 2) isolation of enterovirus in cell culture (Hep-2, FrhK-4), 3) cell cytotoxicity in Vero cells and 4) the ability to inactivate 10 ID50% of poliovirus in cell culture. The Most Probable Number/100 ml in surrounding water was higher than the accepted standard for recreational waters, although the number of fecal coliforms in meats and body fluids was lower than in the external water. No cytopathogenic agents were isolated, but we found nitrate and sulphate concentrations that exceeded maxima for human consumption and recreation. The intrinsic cytotoxicity of the samples was at a 1/8 dilution, but some samples were cytotoxic at dilutions of 1/128. Body fluids were more cytotoxic than meats, but a positive correlation between cytotoxicity and chemical contamination was not determined: apparently other pollutants not identified in this study were responsible. Fluid and meat capacity to inactivate 10 ID50% of poliovirus in cell culture was demonstrated. Samples that were toxic for cell cultures also showed a higher percentage of poliovirus inactivation. Monitoring chemical pollution in these waters is highly recommended.

  10. Extirpation of freshwater mussels (Bivalvia: Unionidae) following the invasion of dreissenid mussels in an interconnecting river of the Laurentian Great Lakes

    Science.gov (United States)

    Schloesser, Don W.; Metcalfe-Smith, Janice L.; Kovalak, William P.; Longton, Gary D.; Smithee, Rick D.

    2006-01-01

    Previous (1992-1994) surveys for native freshwater mussels (Unionidae) along main channels of the Detroit River showed that unionids had been extirpated from all but four sites in the upper reaches of the river due to impacts of dreissenid mussels (Dreissena polymorpha and D. bugensis). These four sites were surveyed again in 1998 using the same sampling method (timed-random searches) to determine if they may serve as ''refugia'' where unionids and dreissenids co-exist. Two additional sites were sampled using additional methods (excavated-quadrat and line-transect searches) for comparison with unpublished data collected in 1987 and 1990. A total of four individuals of four species (Actinonaias ligamentina, Cyclonaias tuberculata, Lasmigona complanata and Pleurobema sintoxia) were found by timed-random searches at four sites in 1998 compared to 720 individuals of 24 species in 1992 and 39 individuals of 13 species in 1994. Excavated-quadrat and line-transect searches at the two additional sites yielded only one live specimen of Ptychobranchus fasciolaris compared to 288 individuals of 18 species in 1987 and 1990. Results of this study suggest that remaining densities of unionids in channels of the Detroit River are too low to support viable reproducing populations of any species. Therefore, we conclude that unionids have been extirpated from main channels of the Detroit River due to dreissenid infestation. As the Detroit River was one of the first water bodies in North America to be invaded by dreissenids, it is likely that unionids will also be extirpated from many other rivers and lakes across eastern North America over the next few decades. Resource agencies should be encouraged to implement active management programs to protect remaining unionid populations from zebra mussels.

  11. Benthic communities on hard substrates covered by Limnoperna fortunei Dunker (Bivalvia, Mytilidae at an estuarine beach (Río de la Plata, Argentina

    Directory of Open Access Journals (Sweden)

    Fernando G. Spaccesi

    2012-01-01

    Full Text Available The structure and composition of benthic communities on hard substrates covered by the nonindigenous bivalve Limnoperna fortunei Dunker, the golden mussel, were quantified in the middle zone of the Río de la Plata Estuary (Argentina from April 2001 through March 2002. A total of 26 taxa were recorded. L. fortunei and Nematoda were the central and dominant groups, with a prodigious abundance of over 80%. The prevalence of L. fortunei, rather than the environmental variables, regulated the dynamics of the associated invertebrate fauna. The golden mussel alters both the structure and function of benthic native communities on hard substrates, allows a higher surface available for colonization and refuge, and provides food source to deposit-feeding organisms in the form of organic or residual material. The mussel also increases the abundance and diversity of taxa on hard substrata - such as Oligochaeta, Hirudinea, Tardigrada, Chironomidae, Copepoda, Tanaidacea, and Hydrachnidia. Similarities and nonparametric multidimensional-scaling analyses indicated that the benthic composition had a seasonal variation. L. fortunei has an environmental impact, an ability to invade new freshwater ambiences worldwide and ecological characteristic comparable to those of Dreissena polymorpha Pallas (the zebra mussel of North America and Europe.

  12. Distribución, abundancia y aspectos biológicos de la almeja Polymesoda solida Phillippi, 1846 (Bivalvia: Corbiculidae en la Isla De Salamanca, Caribe Colombiano

    Directory of Open Access Journals (Sweden)

    Blanco Jacobo

    2006-06-01

    Full Text Available Con el propósito de evaluar el estado actual de la almeja estuarina Polymesoda solida como recurso ecológico y
    pesquero, se estudiaron diversos aspectos de la población en el sector occidental de la isla de Salamanca, en el Caribe colombiano. El muestreo se llevó a cabo mensualmente en cuatro ciénagas interconectadas de este Parque Natural, tres de ellas sometidas a explotación, entre abril y noviembre de 2004. Se estimó la densidad por metro cuadrado y se efectuaron mediciones de largo, alto y espesor de las conchas para obtener las distribuciones de tallas y relaciones morfométricas. Para conocer la condición física de los animales se estimaron índices de condición con base en los pesos de concha y partes blandas y se calculó el porcentaje de materia
    orgánica en los tejidos blandos. El estado reproductivo se determinó a partir de observaciones en fresco del material gonadal. Se llevaron a cabo análisis de correlación y de regresión múltiple para conocer el grado de influencia de diversas variables ambientales sobre aspectos biológicos de la almeja. Las condiciones ambientales en las ciénagas variaron en función de la distancia al río Magdalena y al mar, mostrando para ciertas variables un patrón marcadamente estacional, obedeciendo a las épocas climáticas. Se destacaron las diferencias en las características de P. solida entre sitios de muestreo, presentándose rangos de tallas, densidades, índices de condición y tipo de sustrato muy característico para cada ciénaga. La densidad varió inversamente con la talla, las longitudes de los ejemplares oscilaron entre 9,8 mm y 50 mm, predominando el rango de 25-30 mm. Se encontraron
    reclutas (<5mm ocasionalmente en orillas arenosas de algunos sectores. Las fluctuaciones en el índice de condición de los individuos se asociaron a los cambios en el estado fisiológico a lo largo del tiempo, muy dependientes del estado reproductivo. También se observaron diferencias entre ciénagas, señalándose la importancia de la salinidad, pH y transparencia del agua en las características biológicas de la población y por lo tanto se corroboró la importancia del régimen hídrico en su regulación. La mejor condición física de P. solida estuvo directamente relacionada con la menor salinidad a nivel espacial y temporal. Esto permitió establecer que la almeja en la zona de estudio posiblemente se adapta mejor a salinidades muy bajas en relación con lo encontrado
    en otros lugares del mundo. La gran variabilidad en las distribuciones de tallas y en la densidad de individuos
    se asoció a la heterogeneidad de un sistema estuarino altamente cambiante y a la explotación pesquera, debido
    al método de pesca selectivo, ocasionando discontinuidades en las distribuciones de tallas a nivel temporal y escasez de tallas muy pequeñas o muy grandes. Las diferencias espaciales en la relación talla-peso y en las relaciones morfométricas, así como la segregación de tallas y el reclutamiento en áreas diferentes a las de los adultos, sugieren que la población de P. solida se distribuye de acuerdo con criterios de modelos metapoblacionales y se resalta que su manejo como recurso, debe plantearse de acuerdo a tales criterios, pues de acuerdo con la información pesquera, la especie presenta varias señales de sobreexplotación.

  13. 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.

  14. [Mollusks in the Bou Grara Sea (southern, Tunisia): initial biometric data on Cerastoderma glaucum Poirêt, 1789 (Bivalvia, Eulamellibranchia, Cardiae)].

    Science.gov (United States)

    Zaouali, J

    1979-12-01

    The statistical study of Cerastoderma glaucum in the little harbour of Bou Grara points out the presence of 21 ribs on the valves, a mean growth of 19,3 mm for the first year of life and a mean longevity of two years; the formation of rest rings is made at summer period. The dynamical study of the population shows its large homeostasy.

  15. 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.

  16. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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)

  19. 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 ...

  20. Etude comparative entre la microflore de l'appareil digestif de Teredo navalis L. (Teredinidae-bivalvia) et les population bactériennes de son environnement

    OpenAIRE

    Martinez, J-c.

    1982-01-01

    L'utilisation des deux milieux de culture (2216E et T.C.B.S.) a permis d'isoler 333 souches bactériennes provenant des appareils digestifs de tarets, des galeries servant d'habitat dans les bois et de l'eau de mer environnante. Les échantillonnages ont été réalisés dans la rade de Brest en trois périodes, de février à avril 1980. La description de ces souches par 109 caractères écologiques, biochimiques et nutritionnels, permet de définir les caractéristiques essentielles des conitituants de ...

  1. Características biológicas de una población de Pteria sterna(Bivalvia: Pteriidae en Zorritos, Tumbes, Perú

    Directory of Open Access Journals (Sweden)

    Elmer Ordinola

    2013-12-01

    Full Text Available Entre abril y noviembre de 2011 se analizó una población de Pteria sterna (Gould, 1851 que se encontraba adherida a una red de cerco hundida en Zorritos, Tumbes, Perú (3º40’30.7”S - 80º40’20.8”W. Los individuos presentaron tallas de 5 a 94 mm de altura valvar. La talla promedio se incrementó hacia finales del periodo evaluado. La estructura de tallas mostró la presencia de reclutas en la mayoría de meses evaluados, con máximos en abril y agosto. Se registraron cinco grupos de edad. La proporción sexual fue 1:1. Los desoves fueron continuos, a excepción de junio, con un máximo en noviembre. La relación altura valvar-peso total no mostró diferencias por sexos. El crecimiento de esta especie fue alométrico negativo. Las demás relaciones (potencial: peso del cuerpo-peso total, y lineales: peso del cuerpo-peso total y peso del talo – peso total presentaron elevadas correlaciones. El rendimiento del músculo (talo representó el 6.3% del peso total.

  2. 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.

  3. The complete maternally and paternally inherited mitochondrial genomes of the endangered freshwater mussel Solenaia carinatus (Bivalvia: Unionidae and implications for Unionidae taxonomy.

    Directory of Open Access Journals (Sweden)

    Xiao-Chen Huang

    Full Text Available Doubly uniparental inheritance (DUI is an exception to the typical maternal inheritance of mitochondrial (mt DNA in Metazoa, and found only in some bivalves. In species with DUI, there are two highly divergent gender-associated mt genomes: maternal (F and paternal (M, which transmit independently and show different tissue localization. Solenaia carinatus is an endangered freshwater mussel species exclusive to Poyang Lake basin, China. Anthropogenic events in the watershed greatly threaten the survival of this species. Nevertheless, the taxonomy of S. carinatus based on shell morphology is confusing, and the subfamilial placement of the genus Solenaia remains unclear. In order to clarify the taxonomic status and discuss the phylogenetic implications of family Unionidae, the entire F and M mt genomes of S. carinatus were sequenced and compared with the mt genomes of diverse freshwater mussel species. The complete F and M mt genomes of S. carinatus are 16716 bp and 17102 bp in size, respectively. The F and M mt genomes of S. carinatus diverge by about 40% in nucleotide sequence and 48% in amino acid sequence. Compared to F counterparts, the M genome shows a more compact structure. Different gene arrangements are found in these two gender-associated mt genomes. Among these, the F genome cox2-rrnS gene order is considered to be a genome-level synapomorphy for female lineage of the subfamily Gonideinae. From maternal and paternal mtDNA perspectives, the phylogenetic analyses of Unionoida indicate that S. carinatus belongs to Gonideinae. The F and M clades in freshwater mussels are reciprocal monophyly. The phylogenetic trees advocate the classification of sampled Unionidae species into four subfamilies: Gonideinae, Ambleminae, Anodontinae, and Unioninae, which is supported by the morphological characteristics of glochidia.

  4. Sex-linked mitochondrial behavior during early embryo development in Ruditapes philippinarum (Bivalvia Veneridae) a species with the Doubly Uniparental Inheritance (DUI) of mitochondria.

    Science.gov (United States)

    Milani, Liliana; Ghiselli, Fabrizio; Passamonti, Marco

    2012-05-01

    In most metazoans mitochondria are inherited maternally. However, in some bivalve molluscs, two mitochondrial lineages are present: one transmitted through females (F-type), the other through males (M-type). This unique system is called Doubly Uniparental Inheritance (DUI) of mitochondria. In DUI species, M-type mitochondria have to invade the germ line of male embryos during development, otherwise sperm would transmit F-type mtDNA and DUI would fail. The mechanisms by which sperm mitochondria enter the germ line are still unknown. To address this question, we traced the movement of spermatozoon mitochondria (M-type) in embryos of the DUI species Ruditapes philippinarum by fertilizing eggs with sperm stained with the mitochondrial-specific vital dye MitoTracker Green. As in Mytilus DUI species, in R. philippinarum the distribution of sperm mitochondria follows two different patterns: an aggregated one in which these organelles locate near the first cleavage furrow, and a dispersed one in which sperm mitochondria are scattered. The presence of the two mitochondrial patterns in these taxa, together with their absence in species with Strictly Maternal Inheritance (SMI), confirms that their occurrence is related to DUI. Moreover, a Real-Time qPCR analysis showed that neither M-type nor F-type mitochondria undergo replication boosts in the earliest embryo development. This is the first study on sex-linked mtDNA copy number carried out by qPCR analysis on embryos of a DUI species and the first time the segregation patterns of sperm mitochondria are described in a DUI system other than Mytilus.

  5. Combined Use of Morphological and Molecular Tools to Resolve Species Mis-Identifications in the Bivalvia The Case of Glycymeris glycymeris and G. pilosa

    Science.gov (United States)

    Holmes, Anna; Bušelić, Ivana; Thébault, Julien; Featherstone, Amy

    2016-01-01

    Morphological and molecular tools were combined to resolve the misidentification between Glycymeris glycymeris and Glycymeris pilosa from Atlantic and Mediterranean populations. The ambiguous literature on the taxonomic status of these species requires this confirmation as a baseline to studies on their ecology and sclerochronology. We used classical and landmark-based morphometric approaches and performed bivariate and multivariate analyses to test for shell character interactions at the individual and population level. Both approaches generated complementary information. The former showed the shell width to length ratio and the valve asymmetry to be the main discriminant characters between Atlantic and Mediterranean populations. Additionally, the external microsculpture of additional and finer secondary ribs in G. glycymeris discriminates it from G. pilosa. Likewise, landmark-based geometric morphometrics revealed a stronger opisthogyrate beak and prosodetic ligament in G. pilosa than G. glycymeris. Our Bayesian and maximum likelihood phylogenetic analyses based on COI and ITS2 genes identified that G. glycymeris and G. pilosa form two separate monophyletic clades with mean interspecific divergence of 11% and 0.9% for COI and ITS2, respectively. The congruent patterns of morphometric analysis together with mitochondrial and nuclear phylogenetic reconstructions indicated the separation of the two coexisting species. The intraspecific divergence occurred during the Eocene and accelerated during the late Pliocene and Pleistocene. Glycymeris pilosa showed a high level of genetic diversity, appearing as a more robust species whose tolerance of environmental conditions allowed its expansion throughout the Mediterranean. PMID:27669452

  6. Identification, cloning and environmental factors modulation of a αβ defensin from the Lessepsian invasive mussel Brachidontes pharaonis (Bivalvia: Mytilidae

    Directory of Open Access Journals (Sweden)

    MG Parisi

    2015-10-01

    Full Text Available Immunological effectors of invasive species playing a role in addressing new colonization are still poorly studied. In the present study the cDNA sequence of the defensin from a Lessepsian invasive species, the Red Sea mussel Brachidontes pharaonis, was cloned using RACE method. Defensins are a class of widely known antimicrobial peptides (AMPs, oligopeptides with a broad spectrum of targeted organisms ranging from viruses to parasites. Analysis of BpDef sequence (262 bp revealed the presence of an ORF coding for 81 amino acids. The full-length amino acid sequence showed the highest similarity to antimicrobial peptides MGD1 and MGD2 sequence from Mytilus galloprovincialis. Phylogenetic analysis suggested that BpDef belongs to the αβ defensin AMPs with a typical domain structurally characterized by a α helix and two β sheets. BpDef mRNA is located in circulating hemocytes with small intra-cytoplasmic granules and with large granules. The transcription of defensin gene was modulated by the stress from temperatures and oxygenation condition. Temperatures of 20 °C did not stimulate a BpDef transcription over a short time. At 30 °C the kinetics of BpDef gene transcription showed up regulation after one day, while it was down regulated after six days, both under normoxia and hypoxia conditions.

  7. Characterisation of 12 microsatellite loci in the Vietnamese commercial clam Lutraria rhynchaena Jonas 1844 (Heterodonta: Bivalvia: Mactridae) through next-generation sequencing.

    Science.gov (United States)

    Thai, Binh Thanh; Tan, Mun Hua; Lee, Yin Peng; Gan, Han Ming; Tran, Trang Thi; Austin, Christopher M

    2016-05-01

    The marine clam Lutraria rhynchaena is gaining popularity as an aquaculture species in Asia. Lutraria populations are present in the wild throughout Vietnam and several stocks have been established and translocated for breeding and aquaculture grow-out purposes. In this study, we demonstrate the feasibility of utilising Illumina next-generation sequencing technology to streamline the identification and genotyping of microsatellite loci from this clam species. Based on an initial partial genome scan, 48 microsatellite markers with similar melting temperatures were identified and characterised. The 12 most suitable polymorphic loci were then genotyped using 51 individuals from a population in Quang Ninh Province, North Vietnam. Genetic variation was low (mean number of alleles per locus = 2.6; mean expected heterozygosity = 0.41). Two loci showed significant deviation from Hardy-Weinberg equilibrium (HWE) and the presence of null alleles, but there was no evidence of linkage disequilibrium among loci. Three additional populations were screened (n = 7-36) to test the geographic utility of the 12 loci, which revealed 100 % successful genotyping in two populations from central Vietnam (Nha Trang). However, a second population from north Vietnam (Co To) could not be successfully genotyped and morphological evidence and mitochondrial variation suggests that this population represents a cryptic species of Lutraria. Comparisons of the Qang Ninh and Nha Trang populations, excluding the 2 loci out of HWE, revealed statistically significant allelic variation at 4 loci. We reported the first microsatellite loci set for the marine clam Lutraria rhynchaena and demonstrated its potential in differentiating clam populations. Additionally, a cryptic species population of Lutraria rhynchaena was identified during initial loci development, underscoring the overlooked diversity of marine clam species in Vietnam and the need to genetically characterise population representatives prior to microsatellite development. The rapid identification and validation of microsatellite loci using next-generation sequencing technology warrant its integration into future microsatellite loci development for key aquaculture species in Vietnam and more generally, aquaculture countries in the South East Asia region.

  8. Colonization of Asian freshwaters by the Mytilidae (Bivalvia): a comparison of Sinomytilus harmandi from the Tonle-Sap River, Phnom Penh, Cambodia, with Limnoperna fortunei

    DEFF Research Database (Denmark)

    Morton, Brian; Dinesen, Grete E.

    2010-01-01

    Sinomytilus harmandi occurs in the lakes and rivers of Indochina, notably in Cambodia, Laos, Thailand and Vietnam and, again notably, the Mekong River and its myriad tributaries. Hitherto, this species and its four junior synonyms have been examined only superficially. Because of an interior shell...

  9. 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.

  10. 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.

  11. 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

  12. Aspectos da reprodução e dinâmica populacional de Chione pubera (Bory Saint-Vicent (Bivalvia, Veneridae no sul do Brasil General features of the reproduction and population dynamics of Chione pubera (Bory Saint-Vicent (Bivalvia, Veneridae in South Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Borzone

    2001-06-01

    Full Text Available Material collected with a 2-meter wide beam trawl during eight surveys conducted from December 1995 to February 1997 was used for a first preliminary description of the reproduction and population dynamics of the edible venerid bivalve Chione pubera (Bory Saint-Vicent, 1827. Greatest catches were found between 30 to 35 meters depth, on fine sandy bottoms with a mud content lower than 10%. Dry weight meat condition index showed highest values during autumn and lowest values from winter to summer months. Histological analysis of gonadal tissue showed a continuous reproduction, with peaks of maturation on autumn and spring, Spawning was related with the increase of water temperature, that occurs twice a year in the region as a consequence of a particular hydrological characteristic of the inner continental shelf. Size frequency distribution showed a unique principal mode with slow if any displacement through time, indicating a long lived species.

  13. 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.

  14. Use of clearance rate in Choromytilus chorus (Bivalvia: Mytilidae as a non-destructive biomarker of aquatic pollution El uso de la tasa de aclaramiento en Choromytilus chorus (Bivalvia: Mytilidae como biomarcador no destructivo de la polución acuática

    Directory of Open Access Journals (Sweden)

    BEATRIZ TORO

    2003-06-01

    Full Text Available Reduction in clearance rate was observed in the mussel Choromytilus chorus in relation to the degree of environmental pollution. Three sampling sites included the polluted San Vicente Bay, middling polluted Corral Bay, and weakly polluted Yaldad Bay in southern Chile. Pollution levels were estimated by quantitative analysis of polynuclear aromatic hydrocarbons (PAHs in mussel tissue from the three sites. Mussels from San Vicente showed lowest clearance rates and highest PAHs levels in both spring 1998 and summer 1999. Populations from Corral and Yaldad showed generally low levels of PAHs, so the mussels from Yaldad showed the highest rates of clearance in comparison to Corral and San Vicente populations. The significant negative relationship (P Se observó un deterioro de la tasa de aclaramiento en Choromytilus chorus de acuerdo al grado de polución ambiental. Se incluyeron tres sitios de muestreos, la bahía de San Vicente muy contaminada, la bahía de Corral con una polución intermedia y la bahía de Yaldad, al sur de Chile, con una baja contaminación. Los niveles de polución fueron estimados por análisis cuantitativos de hidrocarburos aromáticos polinucleares (HAPs en el tejido de los choros zapatos de los tres sitios de muestreo. Los choros zapatos de San Vicente mostraron la menor tasa de aclaramiento y altos niveles de HAPs, tanto en la primavera de 1998 como en el verano de 1999. Las poblaciones de Corral y Yaldad mostraron en general bajos niveles de HAPs, en tanto que los ejemplares de Yaldad presentaron altas tasas de aclaramiento en comparación con las poblaciones de Corral y San Vicente. La relación negativa significativa (P < 0,001 entre la polución en el tejido de los choros zapatos y sus tasas de aclaramiento, argumenta la utilidad del método como un biomarcador no destructivo para evaluar el impacto ambiental de la polución en las especies marinas

  15. Use of clearance rate in Choromytilus chorus (Bivalvia: Mytilidae) as a non-destructive biomarker of aquatic pollution El uso de la tasa de aclaramiento en Choromytilus chorus (Bivalvia: Mytilidae) como biomarcador no destructivo de la polución acuática

    OpenAIRE

    BEATRIZ TORO; Jorge M Navarro; HERNÁN PALMA-FLEMING

    2003-01-01

    Reduction in clearance rate was observed in the mussel Choromytilus chorus in relation to the degree of environmental pollution. Three sampling sites included the polluted San Vicente Bay, middling polluted Corral Bay, and weakly polluted Yaldad Bay in southern Chile. Pollution levels were estimated by quantitative analysis of polynuclear aromatic hydrocarbons (PAHs) in mussel tissue from the three sites. Mussels from San Vicente showed lowest clearance rates and highest PAHs levels in both s...

  16. 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.

  17. PLICATOUNIO (GUANGXIPLICATOUNIO), A NEW NAME FOR PLICATOUNIO(GUANGXICONCHA) YAO AND YU, 1986 (BIVALVIA: PLICATOUNIONIDAE),PREOCCUPIED BY GUANGXICONCHA ZHANG, 1977 (BIVALVIA: LUNULACARDIIDAE)%新建广西褶珠蚌(新名)(Guangxiplicatounio nom.nov.)替代晚出名Guangxiconcha Yao and Yu,1986(非Guangxiconcha Zhang,1977)

    Institute of Scientific and Technical Information of China (English)

    方宗杰

    2007-01-01

    姚培毅、于菁珊(1986)为广西扶绥下白垩统的褶珠蚌类标本建立了一个新亚属Plicatounio(Guangxiconcha)Yao and Yu,以Plicatounio(Guangxiconcha)fortis Yao and Yu,1986(230页,图版1,图4;图版2,图3,6)作为模式种。

  18. Distribuição sazonal e reprodução de Neocorbicula limosa (Maton (Bivalvia, Corbiculidae no Lago Guaíba, Rio Grande do Sul, Brasil Seasonal distribution and reproduction of Neocorbicula limosa (Maton (Bivalvia, Corbiculidae in the Guaíba Lake, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Teimo Focht

    2001-03-01

    Full Text Available Neocorbicula limosa (Maton, 1811 is the only species of that South American genus that occurs in the hydrographic basins of Rio Grande do Sul State, Brazil. Seasonal quantitative collections between 1995 and 1996 in the lake Guaiba were accomplished, with the aim to know the reproductive dynamics and environmental preferences of populations of N. limosa. A substratum constituted by medium to coarse sands at an 'average depth around 2m shown to be favorable to installation of population of N. limosa. The largest population density (2.496 ind./m² was registered in summer. Embryos at various development phases were registered inside individuals. The shell sizes of these individuals started from 8mm in length. The embryo's size could reach ¼ of the shell-mother's size, and their liberation occurs through the rupture of the gills.

  19. 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

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    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.

  20. Allozymic variation in the clam genus Eurhomalea (Bivalvia: Veneriidae along southern South American coast Variación alozímica en el género de almejas Eurhomalea (Bivalvia: Veneriidae a lo largo de la costa sur de Sudamérica

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    M.H GALLARDO

    2003-09-01

    Full Text Available The correspondence between allozymic variation and specific differentiation was studied in four populations corresponding to the three nominal, allopatric species of clam genus Eurhomalea (E. rufa, E. lenticularis, E. exalbida described for southern South America. Allozyme variation scored in 12 loci was high as indicated by heterozygosity levels (15.8-20.7 % and by the presence of only three monomorphic loci (Hk-2, Icd-2, and Xdh-1. These high estimates of allelic variability were influenced by the low levels of interspecific genetic similarity (I = 0.64 and for the high conspecific values of genetic identity observed. The high estimates of substructuring found at the species level (F ST = 0.39 contrasted with the low differentiation (F ST = 0.027 and high migration rate (Nm = 9 existing among conspecific samples. Diagnostic allele fixation coinciding with specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, alpha-Gpd, Icd-1, Ldh, Odh, Pgm-3 differed sharply in frequency among species. The Wagner procedure and the neighbor-joining algorithm produced a similar tree topology highly related to the geographic distance and to their taxonomic recognition. The lack of coincidence between patterns of allozymic variation and the two distinctive shell morphs (flat and globoid occurring in E. exalbida from Ushuaia bay do not support their taxonomic recognition.Se estudió la correspondencia entre la variación bioquímica y la diferenciación específica en cuatro poblaciones correspondientes a las tres especies nominales y alopátricas en las almejas del género Eurhomalea (E. rufa, E. lenticularis, E. exalbida descritas para la zona sur de Sudamérica. La variación alozímica registrada en 12 loci fue alta como lo indican los altos niveles de heterocigosidad (15,8-20,7 % y por la presencia de solo tres loci monomórficos (Hk-2, Icd-2 y Xdh-1. Esta alta estimación de variabilidad alélica influyó en los bajos niveles de similitud genética interespecífica (I = 0,64 y en los altos valores de identidad genética conespecífica observados. El alto grado de subestructuración poblacional interespecífica (F ST = 0,39 contrasta con la poca diferenciación (F ST = 0,027 y la alta tasa de migración (Nm = 9 existente a nivel intraespecífica. Coincidiendo con la situación específica de estas tres especies, se observó fijación alternativa de alelos en el locus Hk-1 mientras que los loci (Adh, alfa-Gpd, Idh-1, Ldh, Odh, Pgm-3 están fuertemente diferenciados en sus frecuencias. El procedimiento de Wagner y el algoritmo de Unión al Vecino produjeron topologías similares, altamente relacionadas con la distancia geográfica y con la situación taxonómica. La falta de coincidencia entre los patrones de variación y los dos morfos (planas y globosas presentes en E. exalbida de la bahía Ushuaia no apoyan su reconocimiento taxonómico como entidades genéticas discretas.

  1. Ocorrência do molusco asiático Corbicula fluminea (Müller, 1774 (Bivalvia, Corbiculidae no baixo rio Negro, Amazônia central Occurrence of the Asian mollusc Corbicula fluminea (Müller, 1774 (Bivalvia, Corbiculidae in the lower Rio Negro, Central Amazon Region, Brazil

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    Daniel Mansur Pimpão

    2008-01-01

    Full Text Available O rio Negro é um dos maiores afluentes do rio Amazonas, mas poucos moluscos foram registrados até o momento para aquele rio, representados apenas por gastrópodes. Foi registrada a presença do molusco bivalve exótico Corbicula fluminea na margem esquerda do baixo rio Negro, no lago do Tupé e no Catalão - margem direita do rio Negro, todas localidades no município de Manaus, Brasil. O registro foi realizado por meio da coleta de conchas e espécimes vivos. É o primeiro registro de C. fluminea para o estado do Amazonas e Amazônia central.The Rio Negro is one of the biggest Rio Amazonas tributaries. Few molluscs have been registered to that river yet, represented only by gastropods. It is reported the occurrence of the exotic bivalve mollusc Corbicula fluminea in left bank margin of Rio Negro, Lago do Tupé and Catalão - right bank margin of Rio Negro, all localities in the municipality of Manaus, Brazil. The species is recorded by a collection of shells and specimens alive. This is the first occurrence of C. fluminea in the Amazon State and Central Amazon.

  2. 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

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    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.

  3. 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.

  4. 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...

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

    Science.gov (United States)

    1992-09-01

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

  6. THREE YEAR VARIATION IN SHELL GROWTH OF THEMUSSEL, ELLIPTIO WACCAMAWENSIS (LEA), IN LAKEWACCAMAW, A BAY LAKE IN NORTH CAROLINA

    Science.gov (United States)

    Freshwater mussels (Bivalvia: Unionidae) are one of the most endangered animal taxa in North America, and continued research on unionids will improve management decisions regarding their conservation. One unexplored aspect of unionid ecology is the magnitude of interannual variat...

  7. Vetenfinf se ha actualizado recientemente

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    Veterinaria.org

    2008-02-01

    Full Text Available ResumenSe trata de un sitio web alojado en el servidor de Veterinaria.org y mantenido por el Dr. Norberto Fondevila, del Instituto de Virologia CICVyA- INTA Cautelar de Argentina .

  8. Ion microprobe assessment of the heterogeneity of Mg/Ca, Sr/Ca and Mn/Ca ratios in Pecten maximus and Mytilus edulis (bivalvia shell calcite precipitated at constant temperature

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    P. S. Freitas

    2009-07-01

    Full Text Available Small-scale heterogeneity of biogenic carbonate elemental composition can be a significant source of error in the accurate use of element/Ca ratios as geochemical proxies. In this study ion microprobe (SIMS profiles showed significant small-scale variability of Mg/Ca, Sr/Ca and Mn/Ca ratios in new shell calcite of the marine bivalves Pecten maximus and Mytilus edulis that was precipitated during a constant-temperature culturing experiment. Elevated Mg/Ca, Sr/Ca and Mn/Ca ratios were found to be associated with the deposition of elaborate shell features, i.e. a shell surface stria in P. maximus and surface shell disturbance marks in both species, the latter a common occurrence in bivalve shells. In both species the observed small-scale elemental heterogeneity most likely was not controlled by variable transport of ions to the extra-pallial fluid, but by factors such as the influence of shell organic content and/or crystal size and orientation, the latter reflecting conditions at the shell crystal-solution interface. In the mid and innermost regions of the P. maximus shell the lack of significant small-scale variation of Mg/Ca ratios, which is consistent with growth at constant temperature, suggest a potential application as a palaeotemperature proxy. Cross-growth band element/Ca ratio profiles in the interior of bivalve shells may provide more promising palaeo-environmental tools than sampling from the outer region of bivalve shells.

  9. 双壳纲贝类18S rRNA基因序列变异及系统发生%18S rRNA gene variation and phylogenetic analysis among 6 orders of Bivalvia class

    Institute of Scientific and Technical Information of China (English)

    孟学平; 申欣; 程汉良; 赵娜娜

    2011-01-01

    双壳纲贝类栖息于环境多变的海域,是一个形态学和生态学都具有多样性的类群,清晰而可靠的进化关系对于养殖与相关种类的管理具重要意义.然而,目前对双壳类宏观分子系统学研究的报道较少.研究用18S rRNA基因(18S)分析了双壳类3个亚纲贝类的系统发育关系.从GenBank下载帘蛤目、海螂目、贻贝目、胡桃蛤目、蚶目、珍珠贝目6个目94个种类的18S全/部分序列107个,通过ClustalX软件进行序列比对,用MEGA4.1软件和PHyML软件计算遗传距离,构建系统发育树,研究了双壳类18S变异规律及其在系统发生研究中的应用.结果显示18S有插入/缺失序列,存在长度多态性.序列比对显示有5段约30 70bp的保守区,4段约130 550bp的高变区.碱基组成平均为T:24.4%,C:23.6%,A:24.5%,G:27.5%.G+C含量为51.1%.在1796个比对位点中,变异位点占31.7%,简约信息位点占24.0%.目内科间遗传距离为0.003 0.043,目间遗传距离为0.026 0.093.NJ树和ML树显示贻贝目、珍珠贝目、胡桃蛤目、蚶目和海螂目的缝栖蛤科先分别聚为支持率很高(BPN=94 100)的单系支,后聚为一大支(BPN=100).蛤蜊科与帘蛤目的其他科分离形成一置信度很高的单系支(BPN=93).帘蛤科种类聚为置信度较低(BPN=60)的一支.海螂目、帘蛤目的种类没能完全聚到所属支系,彼此嵌套,缝栖蛤科的种类从海螂目中分离出来.18S资料揭示帘蛤目的蛤蜊科、海螂目的缝栖蛤科已经进化为独立的支系.

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

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    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.

  11. Mollusks (Gastropoda and Bivalvia) of the Multiple-Use Reserve Martín García Island, Río de la Plata River: biodiversity and ecology.

    Science.gov (United States)

    César, I I; Martín, S M; Rumi, A; Tassara, M

    2012-02-01

    The Island of Martin Garcia is located in the Upper Río de la Plata, to the south of mouth the Uruguay River. The aim of the present study was to analyse the biodiversity of the island freshwater mollusks and their relationships to environmental variables. Twelve sampling sites were selected, five were along the littoral section of the island and seven were Inland ponds. Seven major environmental variables were measured: water and air temperature, percentage of oxygen saturation, dissolved oxygen, electrical conductivity, total dissolved solids and pH. Twenty-seven mollusk species were found, Antillorbis nordestensis, Biomphalaria tenagophila tenagophila , B. t. guaibensis, B. straminea, B. peregrina, Drepanotrema kermatoides, D. cimex, D. depressissimum, Chilina fluminea, C. rushii, C. megastoma, Uncancylus concentricus, Hebetancylus moricandi, Stenophysa marmorata, Heleobia piscium, H. parchappii, Potamolithus agapetus, P. buschii, P. lapidum, Pomacea canaliculata, P. megastoma, Asolene platae, Corbicula fluminea, Eupera platensis, Pisidium sterkianum, P. taraguyense and Limnoperna fortunei. UPGMA clustering of species based on their occurrence in different ecological conditions revealed two main species groups. The Canonical Correspondence Analysis suggests that the species distribution is related to the physico-chemical condition of water. Axis two of the ordination diagram displayed the approximately 95.6% of the correlation between species and environmental variables. Dissolved oxygen, conductivity, water temperature and pH showed the highest fluctuations during the sampling period. The species richness (S) showed relationships mainly with water temperature and conductivity. The biodiversity of the gastropods and bivalves from Martín García Island amounts to up to 26 species. Among the Gastropoda, the Planorbidae family made the most sizeable contribution. The Lithogliphidae P. agapetus (26.28%) and P. buschii (9.50%) showed the highest relative frequencies of occurrence within the littoral environments, while the Planorbidae D. cimex (23.83%) and D. kermatoides (11.59%) likewise did so in the inland ponds.

  12. 大连沿海几种腹足类和双壳类的营养成分分析%An Analysis of Nutritive Components of Some Gastropoda and Bivalvia in Dalian Coastline

    Institute of Scientific and Technical Information of China (English)

    陶平; 许庆陵; 谭淑荣

    2000-01-01

    对大连沿海所产的3种腹足类和8种双壳类的有机和无机成分进行了测定分析.分析结果表明:蛋白质、脂肪含量均有差异;大多可称之为高蛋白、低脂肪食品.无机营养素含量因种类而不同,但总的变化趋势差距不大.为开发和利用这些海洋贝类资源提供了营养评价的参考依据.

  13. 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.

  14. 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.

  15. 内蒙古宁城道虎沟地区中侏罗世非海相双壳类Ferganoconcha%NON-MARINE FERGANOCONCHA (BIVALVIA) FROM THE MIDDLE JURASSIC IN DAOHUGOU AREA, NINGCHENG COUNTY, INNER MONGOLIA, CHINA

    Institute of Scientific and Technical Information of China (English)

    姜宝玉

    2006-01-01

    Ferganoconcha是广泛分布于我国北部、中亚、西伯利亚和乌拉尔地区下、中侏罗统的一类非海相双壳类.Ferganoconcha sibirica的产出表明道虎沟地区道虎沟层与辽西地区的海房沟组和冀北地区的九龙山组层位相当,时代介于早侏罗世晚期至中侏罗世之间.结合昆虫和叶肢介化石反映的时代,认为道虎沟层的时代可能为中侏罗世早-中期.综合近年来在Ferganoconchidae的分类方面取得的进展,对F.sibirica进行了重新厘定.

  16. A NEW SUBGENUS MATSUMOTOINA (BIVALVIA)FROM THE ASIAN NON-MARINE CRETACEOUS%亚洲非海相白垩系一新亚属松本蚌

    Institute of Scientific and Technical Information of China (English)

    郭福祥

    1982-01-01

    @@ 本文建立一新亚属松本蚌Pseudohyria(Matsumotoina)subgen.nov.,并说明广义的Pseudohyria的地质时代是中、晚白垩世,狭义的Pseudohyria s.s.仍限于晚白垩世,新亚属属于中白垩世产物.

  17. TAXONOMIC STUDY ON MERETRIX( BIVALVIA, VENERIDAE) FROM CHINA SEAS%中国近海文蛤属(双壳纲,帘蛤科)的系统分类学研究

    Institute of Scientific and Technical Information of China (English)

    张素萍; 王鸿霞; 徐凤山

    2012-01-01

    长期以来,我国的文蛤分类存在着严重的问题和混乱现象,它已影响和制约了我国文蛤的水产养殖和遗传育种等相关研究.利用比较形态学和分子生物学技术,对我国沿海分布的文蛤属进行了系统的分类学研究,澄清了混淆种,修订了物种名称,确立了我国沿海文蛤的分类地位,对文蛤属的分类系统进行分子重建.结果表明短文蛤和丽文蛤为近缘种先聚到一起,然后与斧文蛤聚到一起,而琴文蛤、文蛤与该属其它3种文蛤的分歧时间较早.研究结果将为文蛤的分类研究、遗传育种、资源保护和利用提供科学依据.%Most species of bivalves in the genus Meretrix are important commercial clams and distributed in coastal areas of China. Whereas, species identification and classification within the genus Meretrix is frequently confused in literature, e. G. The specific name M. Meretix has been used for various species, which have seriously restricted the researches of Meretrix aquaculture and breeding program. In present study, we clarified the confusable species and revised the species name of five Meretrix species in Chinese coastal zones base on combination of morphological and molecular analyses. Furthermore, the geographic distributions of diese five Meretrix species were confirmed. Molecular phylogenetic analysis based on the CO I sequences showed that M. Petechialis and M. Lusoria cluster together then duster with M. Lamarckii, whereas M. Meretrix and M. Lyrata derived early from a common ancestor compared with the other three species.

  18. 关于晚二叠世克氏蛤类研究中的几个问题%DISCUSSION ON THE STUDY OF THE GENERA CLARAIA AND CLARAIOIDES (BIVALVIA) OF LATE PERMIAN AGE

    Institute of Scientific and Technical Information of China (English)

    方宗杰

    2003-01-01

    对当前二叠-三叠纪克氏蛤类研究中存在的几个问题进行讨论,并对杨逢清等(2002)提出的关于属一级划分的原则提出质疑.通过对Claraia tumida(Patte)的再研究,确认早三叠世的克氏蛤不存在足丝凹口内端呈明显扩大的类型.经过详细的讨论和比较,无论是从形态上,或是生态上,还是从生物地理学的角度,克氏蛤和类克氏蛤在晚二叠世都应被视为两个平行发展的属.类克氏蛤在二叠纪末全部灭绝,未留下任何后裔,它与克氏蛤之间并不存在演化关系.克氏蛤的地质历程是晚二叠世早期至早三叠世晚期,发现于俄罗斯北极区新地岛晚二叠世早期的Claraia novosemelica Lobanova是克氏蛤的最早代表,它应当位于克氏蛤演化的基干部位.

  19. 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.

  20. 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.

  1. 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.

  2. 蚌科20种蚌类肛门的比较解剖及其系统学意义%COMPARATIVE ANATOMY OF THE ANUS OF 20 UNIONID SPECIES (BIVALVIA: UNIONIDAE) AND ITS SYSTEMATIC SIGNIFICANCE

    Institute of Scientific and Technical Information of China (English)

    舒凤月; 吴小平

    2005-01-01

    对蚌科11属20种蚌类肛门进行了比较解剖研究.结果表明,蚌科肛门的结构特征具有重要的分类学价值,肛门类型、肛门相对后闭壳肌位置、肛门壁内表面是否具纵嵴、肠沟终止位置等特征因种类不同而有明显差异,可作为分类依据之一.

  3. 基于CO Ⅰ的中国西施舌DNA条形码%DNA Barcodes of Clam Coelomactata antiquata (Bivalvia: Veneroida)in China Based on CO Ⅰ Gene

    Institute of Scientific and Technical Information of China (English)

    孟学平; 高如承; 申欣; 郑雯雯; 赵娜娜; 程汉良; 田美

    2011-01-01

    以我国大连(DL)、日照(RZ)、启东(QD)、长乐(CL)、漳州(ZZ)和北海(BH)6个野生群体西施舌为研究对象,用引物LCO1490和HCO2198扩增线粒体细胞色素C氧化酶亚基Ⅰ(COⅠ)基因片段序列,PCR产物双向测序,用ClustalX进行DNA序列比对,用MEGA4.1和PhyML软件构建NJ树和ML树,用Arlequin3.11软件进行分子方差分析,研究CO Ⅰ这一特定基因区段作为DNA条形码在识别西施舌地理群体的可行性和有效性.结果获得658 bp的CO Ⅰ核苷酸片段,其T、C、A、G含量分别为42.4%、14.8%、21.8%、21.0%,A+T(64.2%)含量明显高于G+C含量.变异位点占15.3%(101/658),其中简约信息位点占14.1%.群体内遗传距离为0.0020~0.0043,群体间遗传距离为0.0024~0.0883.群体间氨基酸序列无变异.长乐、漳州群体(DH组)与其他群体(HB组)间有显著的遗传分化(FST=0.956~0.970).NJ树和ML树显示长乐、漳州群体聚为一支,北方的大连、日照、启东群体和南方的北海群体聚为置信度较高的另一支(BPN=99),2支间的遗传距离为0.0837,是2支内群体间遗传距离的17.8~23.5倍.本研究结果表明,CO Ⅰ基因片段序列作为鉴定福建西施舌条形码是可行的,但不能将其余群体区别开来.

  4. 橄榄蛏蚌血细胞形态及吞噬能力的初步研究%A Preliminary Study on Morphology and Phagocytic Ability of Hemocytes from Solenaia oleivora (Bivalvia: Unionidae)

    Institute of Scientific and Technical Information of China (English)

    李乾坤; 张桂蓉; 魏开建; 王亚妮; 郭向召; 陈在林; 鄢国新

    2012-01-01

    对橄榄蛏蚌(Solenaia oleivora)血细胞的形态特征和吞噬作用进行了初步研究.基于瑞氏染色后血细胞的形态、颜色、大小等特征,可将橄榄蛏蚌的血细胞分为大颗粒细胞、小颗粒细胞、透明细胞、类淋巴细胞共4种类型.透明细胞的直径最大,小颗粒细胞次之,类淋巴细胞最小;透明细胞的胞核直径最大,小颗粒细胞次之,大颗粒细胞最小.类淋巴细胞的核质比最大(0.67),其他3种细胞的核质比为0.37 ~0.48.4种血细胞所占比例以小颗粒细胞最高(43.6%),透明细胞次之(36.6%),类淋巴细胞最低(7.0%).橄榄蛏蚌平均血细胞浓度为(4.21±1.51)×105个/mL,个体的血细胞浓度与体重(或壳长)不相关(P>0.05),不同体重组(或壳长组)的平均血细胞浓度无显著差异(P>0.05).在37℃体外吞噬试验中,橄榄蛏蚌血细胞对金黄色葡萄球菌的吞噬比例为(43.6±7.0)%,吞噬指数为(0.743±0.145).4种血细胞中,小颗粒细胞的吞噬比例最大(0.288±0.061),类淋巴细胞不具吞噬能力.

  5. 蚌科钩介幼虫的比较形态学研究Ⅱ.六个种幼虫的形态%A COMPARATIVE STUDY ON GLOCHIDIAL MORPHOLOGY OF UNIONIDAE (BIVALVIA)

    Institute of Scientific and Technical Information of China (English)

    吴小平; 梁彦龄; 王洪铸; 欧阳珊

    2000-01-01

    研究了真柱矛蚌、剑状矛蚌、洞穴丽蚌、角月丽蚌、三角帆蚌、褶纹冠蚌等六种蚌的育儿囊的类型和钩介幼虫的形态,应用光镜及扫描电镜对钩介幼虫的形态结构进行了观察和比较.结果表明,真柱矛蚌、剑状矛蚌、三角帆蚌、褶纹冠蚌的育儿囊为外鳃类同生型,洞穴丽蚌、角月丽蚌的育儿囊为外鳃类四生型;钩介幼虫可分为二类:真柱矛蚌、剑状矛蚌、褶纹冠蚌为有钩型,三角帆蚌、洞穴丽蚌、角月丽蚌为无钩型.一些细微结构在不同种之间也存在着差异.

  6. 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)

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    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.

  7. 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.

  8. 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.

  9. Discovery of the Bivalvia Qiyangia Assemblage in Northern Qiangtang Area and Its Stratigraphic Significances%羌北双壳类祁阳蚌组合的发现及其地层学意义

    Institute of Scientific and Technical Information of China (English)

    李乾; 陆刚; 张能; 莫丽群; 许华; 唐朝霞; 卫小彦

    2006-01-01

    藏北羌塘盆地独雪山地区,在原先认为不整合于早侏罗世火山岩系之上的"中侏罗统雀莫错组"中,新近发现了一套早侏罗世淡水双壳类祁阳蚌(Qiyangia)组合,表明羌北盆地存在早侏罗世沉积地层,其为一套海陆交互相沉积的粗碎屑岩→灰岩→细碎屑岩夹灰岩,下侏罗统与中侏罗统为连续沉积.据此资料,该区侏罗系目前采用的岩石地层单位系统及地层的对比认识存有问题,文章对此套早侏罗世沉积的岩石地层划分方案进行了讨论,指出雁石坪地区的侏罗系岩石地层系统作为等时的地层单位运用于羌北盆地北西部并不适宜,羌北盆地已有的地层系统格架有必要重新认识.

  10. 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].

  11. 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

  12. 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

    Johnson, R. I. I Q6 9. lhe n ionacea of li Iliam Irvin Utter- hack. Nauti , I u 2 - 13 .5 . Johnson, R. I. 192. Il lust rat ions of all of the ol lusks...York, No. 4: 1-108. Welsh , J. H. 1933. Photic stimulation and rhythmical con- tractions of the mantle flaps of a lamellibranch. Pro- ceedings of the...National Academy of Sciences, 19: 755-757. Welsh , J. H. 1961. A female Lampsilis covata ’entricosa (Barnes). Science, 134: 73, cover. White, D. S. 1979

  13. 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.

  14. 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

  15. 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

    species appears nearly extirpated in the Upper Mississippi, and no conceivable factor in its decline can be ruled out. Perhaps the instrumental one sim...Leggett, W. C. 1977. The ecology of fish migrations. Annual Review of Ecology and Systematics, 8: 285-308. Lillie, F. R. 1895. The embryology of the

  16. Ion microprobe assessment of the heterogeneity of Mg/Ca, Sr/Ca and Mn/Ca ratios in Pecten maximus and Mytilus edulis (bivalvia shell calcite precipitated at constant temperature

    Directory of Open Access Journals (Sweden)

    H. Kennedy

    2009-01-01

    Full Text Available Small-scale heterogeneity of biogenic carbonate elemental composition can be a significant source of error in the accurate use of element/Ca ratios as geochemical proxies. In this study ion microprobe (SIMS profiles showed significant small-scale variability of Mg/Ca, Sr/Ca and Mn/Ca ratios in new shell calcite of the marine bivalves P. maximus and Mytilus edulis that was precipitated during a constant-temperature culturing experiment. Elevated Mg/Ca, Sr/Ca and Mn/Ca ratios were found to be associated with the deposition of elaborate shell features, i.e. a shell surface stria in P. maximus and surface shell disturbance marks in both species, the latter a common occurrence in bivalve shells. In both species the observed small-scale elemental heterogeneity most likely was not controlled by variable transport of ions to the extra-pallial fluid, but by factors such as shell Mg content influencing Sr and Mn heterogeneity, the influence of shell organic content and/or conditions at the shell crystal-solution interface. Invariant Mg/Ca ratios observed in the mid and innermost regions of the P. maximus shell suggests a potential application as a palaeotemperature proxy.

  17. The biology and functional morphology of Coralliophaga lithophagella (Bivalvia: Arcticoidea: Trapezidae): An abyssate, deep-water, nestler from the Açores. With comparative notes on the estuarine Trapezium liratum from Hong Kong

    Science.gov (United States)

    Morton, Brian

    2014-04-01

    Coralliophaga lithophagella is a nestler of basaltic rocks in the deeper waters (˜57-360 m) of the Açores and of shallower limestone karst in the Mediterranean where it predominately occurs in empty lithophagine burrows. In the Açores, because of low oceanic productivity and the basaltic, un-boreable, substratum, C. lithophagella is but 50% the shell length of continental European conspecifics and the shell's postero-dorsal margin is growth elevated to enhance particle capture. This is also achieved with relatively enormous ctenidia, minute labial palps and a simplified intestine. Unusually amongst the Trapezidae, C. lithophagella is abyssate and the foot is reduced. Also atypically, and during ontogeny, the shell enlarges postero-dorsally to facilitate particle capture. Anatomical features of the representatives of the constituent genera of the Trapezidae are compared one with another and with Arctica islandica (Arcticidae), the constituent families of the Arcticoidea. It is concluded that the Trapezidae constitutes a discrete clade of epibenthic nestlers, possibly descended from an endobenthic arcticoid ancestor, and showing a trend towards a reduction in shell and hinge complexity. The status of Fluviolanatus subtorta with mantle margins filled with single-celled algae and putatively assigned to the Trapezidae, awaits molecular confirmation.

  18. Componentes bioquímicos de los tejidos de Perna perna y P. viridis (Lineo, 1758) (Bivalvia: Mytilidae), en relación al crecimiento en condiciones de cultivo suspendido

    OpenAIRE

    Acosta, Vanessa; Natera,Yolimar; Lodeiros, César; Freites,Luis; Vásquez,Aléikar

    2010-01-01

    Se evaluó los cambios ocurridos en carbohidratos, proteínas y lípidos de la glándula digestiva, músculo y lóbulos gonadales de los mejillones Perna perna y P. viridis bajo condiciones de cultivo suspendido en el Golfo de Cariaco, Venezuela. Paralelamente, se llevaron registros de la condición reproductiva de ambas especies y de temperatura, clorofila a y seston. Los resultados muestraron que en los tejidos analizados de ambas especies, los lóbulos gonadales presentaron las mayores variaciones...

  19. 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,

  20. 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.

  1. Isognomon bicolor (C.B. Adams (Bivalvia, Isognomonidae: primeiro registro para o Brasil, redescrição da espécie e considerações sobre a ocorrência e distribuição de Isognomon na costa brasileira Isognomon bicolor (C.B. Adams (Bivalvia, Isognomonidae: first record to the Brazilian littoral, redescription of the species and comments on the occurrence and distribution of Isognomon in the Brazilian coast

    Directory of Open Access Journals (Sweden)

    Osmar Domaneschi

    2002-06-01

    Full Text Available The bivalve family Isognomonidae is represented in the Western Atlantic by the living genera Crenatula Lamarck, 1804 and Isognomon Solander, 1786. I. alatus (Gmelin, 1791 and I. radiatus (Anton, 1839 are the only Isognomonidae referred to the Brazilian malacofauna. The present work refers to the first record and geographic distribution of I. bicolor along the Brazilian littoral, and presents a re-description of the species based on shell characters, which include those of the prodissoconch. The occurrence of I. alatus and I. radiatus along the Brazilian littoral could not be confirmed, despite the intensive search for these Isognomonidae from Rio Grande do Norte through Rio Grande do Sul.

  2. Estuarine Habitat and Juvenile Salmon: Current and Historical Linkages in the Lower Columbia River and Estuary

    Science.gov (United States)

    2011-12-01

    Polychaeta 1 1 0.01 Bivalvia 5 5 0.03 Arachnida 10 10 20 0.14 Acarina 25 2 27 0.19 Cladocera 4,941 4,416 9,357 64.53 Copepoda 14 72 86 0.59...Bivalvia 1 2 3 0.01 Arachnida 31 34 39 17 48 169 0.48 Acarina 53 34 54 31 62 234 0.66 Cladocera 1,125 917 634 148 8,598 11,422 32.29 Copepoda...17 0.11 Nereis limnicola 6 6 0.04 Oligochaeta 3 3 0.02 Bivalvia 1 1 0.01 Arachnida 3 7 24 2 5 41 0.28 Acarina 6 8 2 16

  3. El aspecto progresivo en traducción : Una investigación sobre el gerundio español y su traducción sueca en La casa de los espíritus de Isabel Allende

    OpenAIRE

    2011-01-01

    El propósito de la tesina es investigar las traducciones suecas de la construcción estar + gerundio para ver si se ha mantenido el aspecto progresivo o no. Si se lo ha mantenido, ¿qué métodos han sido usados? Es un asunto interesante porque la lengua sueca no tiene un equivalente formal al gerundio español y tampoco existen muchos trabajos anteriores sobre esta cuestión. La novela La casa de los espíritus de Isabel Allende con su traducción sueca han servido como corpus y hemos usado cien eje...

  4. Sexual Risk Behavior Among Military Personnel Stationed at Border-Crossing Zones in the Dominican Republic

    Science.gov (United States)

    2010-01-01

    Vinculación Serológica en Poblaciones Vulnerables: Gay, Trans, y otros Hombres que tienen sexo con hombres (GTH), Traba- jadoras Sexuales (TRSX) y Usuarios...Resultados. De todos los entrevistados, 41% revelaron que habían mantenido rela- ciones sexuales casuales en los últimos 12 meses, 37% de los hombres alguna...vez ha- bían mantenido relaciones sexuales con un profesional del sexo (19% en los últimos 12 meses) y 7% de los hombres informaron que habían tenido

  5. A case of associated occurrence of the crab Lauridromia inter-media (Laurie, 1906) (Crustacea: Decapoda: Dromiidae) and the actinian Nemanthus annamensis Carlgren, 1943 (Anthozoa: Actiniaria: Nemanthidae)

    NARCIS (Netherlands)

    Lavaleye, M.S.S.; Hartog, den J.C.

    1995-01-01

    Members of the crab family Dromiidae tend to cover their carapace mostly with sponges or colonial tunicates. More rarely are used other objects or organisms such as solitary Tunicata, Zoantharia (= encrusting anemones), valves of Bivalvia, etc.; a review of these is presented. A new association of a

  6. 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.

  7. Ecology of Buzzards Bay: An Estuarine Profile

    Science.gov (United States)

    1996-09-01

    bucera Polychaeta Ascophyllum nodosum Phaeophyta Tellina tenera Bivalvia Fucus vesiculosus Phaeophyta Ninoe nigripes Polychaeata Chondrus crispus...macroalgal growth. The rockweeds, .4scop/zy//wm nodosum and Fucus vesiculosus , abound on rocks in the littoral zone. Other hard-bottom (sand, shells

  8. A Review of Marine Growth Protection System (MGPS) Options for the Royal Australian Navy

    Science.gov (United States)

    2011-12-01

    DSTO-TR-2631 2.5.2 Protection or remediation  Mexel® 432 is a “ molecular level” filming agent of proprietary formulation which is marketed as...Salinity and temperature tolerances of the green and brown mussels, Perna viridis and Perna perna (Bivalvia: Mytilidae). Revista de Biologia Tropical

  9. Utilización de modelos murinos en ciencias biomédicas

    Directory of Open Access Journals (Sweden)

    Angel Céspedes Rubio

    2005-03-01

    Full Text Available Se define como modelo al animal producido y mantenido bajo condiciones controladas de bioterio, que posee claros antecedentes genéticos y microbiológicos comprobables, del cual pueden obtenerse respuestas fragmentarias de significado bológico fiable y reproducible.

  10. A curious case of herbivory in the common toad Rhinella arenarum during hibernation in captivity conditions

    Directory of Open Access Journals (Sweden)

    Pozzi, Andrea Gabriela

    2012-12-01

    Full Text Available El objetivo de la presente nota es documentar un comportamiento curioso ocurrido con un grupo de animales adultos de Rhinella arenarum que fueron mantenidos en condiciones de hibernación artificial en el laboratorio durante abril-julio del 2012.

  11. El protocolo z39.50: ¿qué es?, ¿para qué sirve?

    OpenAIRE

    Ponsati Obiols, Agnès

    2000-01-01

    Es un protocolo para la recuperación de información basado en la estructura cliente/servidor que facilita la interconexión de sistemas informáticos. Es un protocolo desarrollado y mantenido por bibliotecarios (Biblioteca del Congreso) que ha conseguido su mayoría de edad al ser adoptado como una norma ISO 23950.

  12. Genetic analysis of the marine mussel Perna viridis (Bivalvia: Mytilidae) based on mitochondrial COI sequence and its phylogenetic relationship with other congeneric species%基于COI序列的翡翠股贻贝Perna viridis线粒体遗传特性分析及其近缘种间的系统关系探讨

    Institute of Scientific and Technical Information of China (English)

    位正鹏; 孔晓瑜; 吴相云; 喻子牛

    2009-01-01

    应用通用引物COIL 1490和COtH 2198对翡翠股贻贝Perna viridis的性腺和体细胞线粒体DNA进行PCR扩增,获得661bp长度的COI基因片段,经过比对性腺与体细胞的COI片段,发现雄性性腺与体细胞COI基因均为一个单倍型,即体内只有一种线粒体DNA类型,没有发现双单性遗传现象,雌、雄性腺的COI基因片段变异率很低(0.31%).应用 PAUP构建NJ树、MP树以及贝叶斯法构建了贝叶斯树,对股贻吡属3种间的系统关系进行了分析,结果表明,翡翠股贻贝P.viridis、p.canaliculus和P.perna之间的分化与分歧年代的估算是相吻合的.

  13. 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.

  14. 基于rDNA ITS序列研究蚌科6种类的系统发生关系%The Phylogenetic Analysis of 6 Bivalvia Species(Unionidae)Based on the Sequences of Ribosomal DNA Internal Transcribed Spacer

    Institute of Scientific and Technical Information of China (English)

    许志强; 葛家春; 李晓晖; 霍光明; 潘建林

    2009-01-01

    通过测定核糖体转录间隔区ITS1以及ITS2序列研究了江苏地区蚌科(Unionidae)6种常见贝类--褶纹冠蚌(Cristaria plicata)、三角帆蚌(Hyriopsis cumingii)、背角无齿蚌(Anodneta woodiana woodiana)、扭蚌(Arconaia lanceolata)、圆顶珠蚌(Unio douglasiae)以及背瘤丽蚌(Lamprotula leai)的系统发生关系.结果显示:6种蚌的ITS1 序列长度介于354~439 bp之间,平均G+C百分含量为52.7%;ITS2序列长度介于287~354 bp之间,平均G+C百分含量为51.2%.对6种贝类的相关序列进行比对,ITS1的比对长度包括501个位点,其中有364个变异位点和99个简约信息位点;ITS2的比对长度包括381个位点,其中有259个变异位点和66个简约信息位点.以虾夷扇贝(Mizuhopecten yessoensis)为外群,采用邻接法(NJ)分析6种贝类的系统发生关系,贝类明显聚合为3个类群:类群Ⅰ包括三角帆蚌(H.culingii)和背瘤丽蚌(L.leai),类群Ⅱ包括扭蚌(A.lanceolata)和圆顶珠蚌(U.douglasiae),类群Ⅲ由背角无齿蚌(A.woodiana woodiana)和褶纹冠蚌(C.plicata)组成.

  15. 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.

  16. FROM MORPHOLOGICAL APPROACH TO PARACLADISTIC APPROACH: A BRIEF INTRODUCTION TO THE NEW CLASSIFICATION OF THE UPDATED VERSION OF BIVALVIA TREATISE%从形态分类到准分支系统分类——修订版Treatise双壳纲卷分类系统简介

    Institute of Scientific and Technical Information of China (English)

    方宗杰

    2014-01-01

    修订版Treatise双壳纲卷首卷即将正式出版,其分类系统的纲要已提前公开发表.在古生物学家、现代生物学家和分子生物学家的共同努力下,终于顺利地实现了化石和现生双壳类分类系统的初步融合,与1969版的形态分类相比,整个分类系统已经面目全非.为此,有必要全面介绍其分类方法和原则,介绍新分类系统带来的种种重大变化.新分类系统将进化学派的系统发育概念与分支系统分析方法的合理内核有机结合,发挥后者在方法论方面的优势,摒弃其系统发育即分岐演化的错误概念和某些不合理的分类学原则,如拒绝接受并系群和姐妹群必须具有相同级序等;充分发挥林奈系统的长处并加以改进,形成由共同衍征主导同时也考虑前进演化的林奈式级序体系,准分支系统分类方法由此形成.新方法兼顾分支发生和进化级这两个不同的方面,注重恢复可能的祖-裔关系;主要根据系统树但借鉴分支图方法来确定级序格架,将级序与系统树的分枝点对应,即与衍征的分歧时间对应,使级序的划分不再主观任意;一般将姐妹分类单元置于同一级序,必要时将并系群与其后裔类群置于同一级序,而姐妹群则可能被置于不同的级序.采用近亲单元和准近亲单元分别作为无级序的单系群和并系群的标识,解决了将化石分类群融入现代生物分类系统的技术难题,可简化并有效地保持分类系统的稳定性.新方法使双壳纲完成从形态分类向准分支系统分类的转变,这代表着分类学未来发展的新趋势,而林奈式级序体系则为林奈系统今后的改革提供了新的范例.

  17. 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.

  18. 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.

  19. 双壳类软体动物精子发生及其在系统演化研究中的应用前景%SPERMATOGENESIS OF BIVALVIA AND ITS PROSPECTIVE APPLICATION IN THE STUDY OF PHYL OGENETIC DEVELOPMENT

    Institute of Scientific and Technical Information of China (English)

    竺俊全; 杨万喜

    2002-01-01

    综述了双壳类软体动物精子发生及精子形态结构方面的研究进展.指出双壳类软体动物精子发生过程中精细胞分化具有种、属特异性,精细胞分化的细节是区别个体外部形态很近的物种的依据;精子的形态结构具有种的特征,精子结构的比较研究将成为双壳类软体动物系统演化研究的重要方法之一.

  20. 双壳纲八种贝类的核DNA定量分析及其与进化地位关系的初步探讨%Quantitative Analysis of DNA Contents of Eight Species Belonging to Bivalvia and Primary Discussion on the Relationship Between C-Values and Evolutionary Degrees

    Institute of Scientific and Technical Information of China (English)

    王昭萍; 高凌云; 于瑞海; 黎筠

    2007-01-01

    运用流式细胞仪测定了双壳纲8种贝类的细胞核DNA含量.结果显示,测定贝类的DNA含量分别为(pg):太平洋牡蛎,2.06±0.03;东方海笋,2.11±0.07;近江牡蛎,2.18±0.13;结蚶,2.59±0.10;青蚶,3.08±0.23;砂海螂,3.24±0.28;缢蛏,3.85±0.10;日本镜蛤,5.00±0.20.双因素方差分析表明,同种贝类个体间DNA含量的差异不显著(p>0.05),仅占总差异的0.12%;而种间差异极为显著(p<0.01),比例高达97.45%.本实验所测8种贝类的DNA含量与其进化地位间未呈现出明显的相关性.

  1. Analysis of Genetic Diversity in Populations of Two Commercial Species of Mercenaria mercenaria and Cyclina sinensis (Bivalvia Veneridae) Based on ITS-1 Sequence%帘蛤科两种经济贝类种群的ITS-1序列遗传多样性分析

    Institute of Scientific and Technical Information of China (English)

    吴琪; 潘鹤婷; 潘宝平

    2007-01-01

    利用核糖体DNA转录间隔区ITS-1序列对硬壳蛤(Mercenaria mercenaria)的养殖群体和青蛤(Cyclina sinensis)的野生种群遗传多样性进行了分析.经过PCR扩增、连接与测序后,得到硬壳蛤ITS-1的长度为718~724 bp,青蛤的为665~683 bp,序列用ClustalX 1.83多重比对后,在725 bp组成的同源片段中有714个碱基序列为保守位点,通过DNAsp软件分析,该种群的核酸多态性指数Pi为0.003 02,每位点Eta为0.003 04,并检测出4个单倍型(Haplotype)序列.青蛤在由695 bp组成的同源片段中有644个碱基序列为保守位点,该种群的Pi为0.030 71,每位点Eta为0.037 8,共测出6个单倍型(Haplotype)序列.利用PAUP4.10软件计算出每个种群内单倍型序列间的相对遗传距离,其中,硬壳蛤的遗传距离仅为0.0014~0.005 6,说明其DNA遗传多样性的丰度较低;而野生青蛤种群的遗传距离为0.003 6~0.010 5,说明其遗传多样性比较丰富.文章还初步讨论了双壳类遗传多样性变动的因素及种质保护等问题.

  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. 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.

  5. 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.

  6. 变废为宝——谈牡蛎青的综合开发利用

    Institute of Scientific and Technical Information of China (English)

    李泳; 宋文东; 洪鹏志; 张兆霞

    2007-01-01

    @@ 牡蛎(Oyster)是中国著名而常见的贝类,属于软体动物门(Mollusca),瓣鳃纲(Lanellibranchia),异柱目(Anisomyaria),牡蛎科(Ostreidae).牡蛎俗称蛎黄、蛎子、海蛎等(粤、闽称蚝或蚵,江、浙称蛎黄,山东以北称蛎子或海蛎子).牡蛎是一种营养价值很高的珍贵海产品,为世界性的贝类,目前已发现有100多种,全世界濒海各国几乎都有生产.中国沿海所产的牡蛎约20多种,其总产量在贝类中居首位.

  7. MACROINVERTEBRATES COMPOSITION IN THE BLIZNEC STREAM, SECOND AND THIRD MAKSIMIR LAKE

    Directory of Open Access Journals (Sweden)

    Marina Piria

    2004-06-01

    Full Text Available Qualitative and quantitative macroinvertebrates in spring period was investigated during two years in the first and second Maksimir Lake and Bliznec stream. The domination of Gastropoda was outstanding at these three investigated sites. From time to time stronger development of Gastropoda, Bivalvia, Diptera and Crustacea was noted at the second Maksimir Lake. Gastropoda was dominant at the third Maksimir Lake (from 1.484 to 2.506 g m–2 while Crustacea, Oligochaeta and Hirudinea made important biomass. Species density in the Bliznec stream was quantitative higher than the one at other stations. The dominant group was Gastropoda (from 0.568 to 3.026 g m–2 and there was higher development of Trichoptera, Crustacea, Diptera, Heteroptera and Bivalvia (Table 3 and 4. Bliznec stream water quality, observed by biological method given by Kerovec, ranged from polluted to highly polluted.

  8. New geographic and depth records for deep-water mollusks in the Gulf of California, Mexico Nuevos registros geográficos y batimétricos para moluscos de mar profundo en el golfo de California, México

    Directory of Open Access Journals (Sweden)

    Pablo Zamorano

    2007-12-01

    Full Text Available Six oceanographic cruises (Talud IV-IX were made in the southern Gulf of California aboard the R/V El Puma of the Universidad Nacional Autónoma de México. A total of 56 species of deep-sea mollusks were identified, of which 16 (13 Bivalvia, 2 Gastropoda, 1 Scaphopoda represent either a new geographic or bathymetric record, or both.A partir de 6 campañas oceanográficas (Talud IV-IX realizadas en el sur del golfo de California a bordo del B/O "El Puma" de la Universidad Nacional Autónoma de México, se identificaron 56 especies de moluscos de aguas profundas. De ellas 16 (13 Bivalvia, 2 Gastropoda, 1 Scaphopoda corresponden a un nuevo registro geográfico, batimétrico o ambos.

  9. Pursuing the quest for better understanding the taxonomic distribution of the system of doubly uniparental inheritance of mtDNA

    Directory of Open Access Journals (Sweden)

    Arthur Gusman

    2016-12-01

    Full Text Available There is only one exception to strict maternal inheritance of mitochondrial DNA (mtDNA in the animal kingdom: a system named doubly uniparental inheritance (DUI, which is found in several bivalve species. Why and how such a radically different system of mitochondrial transmission evolved in bivalve remains obscure. Obtaining a more complete taxonomic distribution of DUI in the Bivalvia may help to better understand its origin and function. In this study we provide evidence for the presence of sex-linked heteroplasmy (thus the possible presence of DUI in two bivalve species, i.e., the nuculanoid Yoldia hyperborea(Gould, 1841and the veneroid Scrobicularia plana(Da Costa,1778, increasing the number of families in which DUI has been found by two. An update on the taxonomic distribution of DUI in the Bivalvia is also presented.

  10. Pursuing the quest for better understanding the taxonomic distribution of the system of doubly uniparental inheritance of mtDNA

    Science.gov (United States)

    Gusman, Arthur; Lecomte, Sophia; Stewart, Donald T.; Passamonti, Marco

    2016-01-01

    There is only one exception to strict maternal inheritance of mitochondrial DNA (mtDNA) in the animal kingdom: a system named doubly uniparental inheritance (DUI), which is found in several bivalve species. Why and how such a radically different system of mitochondrial transmission evolved in bivalve remains obscure. Obtaining a more complete taxonomic distribution of DUI in the Bivalvia may help to better understand its origin and function. In this study we provide evidence for the presence of sex-linked heteroplasmy (thus the possible presence of DUI) in two bivalve species, i.e., the nuculanoid Yoldia hyperborea(Gould, 1841)and the veneroid Scrobicularia plana(Da Costa,1778), increasing the number of families in which DUI has been found by two. An update on the taxonomic distribution of DUI in the Bivalvia is also presented. PMID:27994972

  11. Food habits and seasonal variation of stomach contents of tongue sole Cynoglossus semilaevis (Günther) in the Bohai Sea

    Science.gov (United States)

    Dou, Shuozeng

    1993-03-01

    Examination of the food habits and seasonal variation of the stomach contents of adult tongue sole, Cynoglossus semilaevis (Günther) taken in July 1982 July 1983 from Laizhou Bay and the Huanghe River estuary of the Bohai Sea showed crustacea, bivalvia and small fishes comprised the main prey. Invertebrates such as polychaeta, cephalopoda, gastropoda, echinodermata and actiniaria were also intermittently found in them. They intensively fed all the year found (monthly feeding rate of over 80%). The main food items were Alpheus japonica, Alpheus distinguendus. Oratosquilla oratoria, Eucrate crenata and Carcinoplax vestitus, etc. In summer and autumn, the portion of bivalvia such as Cultellus attenuatus and Musculus senhousei increased steadily. From summer to winter, a stable proportion of small fishes such as Rhinogobius pflaumi and Setipinna taty was in the diet.

  12. The Calyptogena magnifica chemoautotrophic symbiont genome

    Energy Technology Data Exchange (ETDEWEB)

    Newton, I.L.; Woyke, T.; Auchtung, T.A.; Dilly, G.F.; Dutton,R.J.; Fisher, M.C.; Fontanez, K.M.; Lau, E.; Stewart, F.J.; Richardson,P.M.; Barry, K.W.; Saunders, E.; Detter, J.C.; Wu, D.; Eisen, J.A.; Cavanaugh, C.M.

    2007-03-01

    Chemoautotrophic endosymbionts are the metabolic cornerstone of hydrothermal vent communities, providing invertebrate hosts with nearly all of their nutrition. The Calyptogena magnifica (Bivalvia: Vesicomyidae) symbiont, Candidatus Ruthia magnifica, is the first intracellular sulfur-oxidizing endosymbiont to have its genome sequenced, revealing a suite of metabolic capabilities. The genome encodes major chemoautotrophic pathways as well as pathways for biosynthesis of vitamins, cofactors, and all 20 amino acids required by the clam.

  13. Nuevos registros de bivalvos marinos para el Perú

    Directory of Open Access Journals (Sweden)

    Carlos Paredes

    2013-03-01

    Full Text Available Seis especies de Bivalvia: Adrana sowerbyana (Orbigny, 1845; Malletia goniura Dall, 1890; Mytilus strigatus Hanley, 1843; Leiosolenus spatiosa (Carpenter, 1857; Pinna rugosa G.B. Sowerby I, 1835 y Delectopecten zacae (Hertlein, 1935 se reportan por primera vez para aguas peruanas. Se da información sobre la distribución, el hábitat y comentarios relevantes de cada una de las especies.

  14. A complex picture of associations between two host mussels and symbiotic bacteria in the Northeast Atlantic

    OpenAIRE

    Rodrigues, CF; Cunha,, Gil; Genio, L.; Duperron, S.

    2013-01-01

    Among chemosymbiotic metazoans found at deep-sea hydrothermal vents, cold seeps and organic falls, members of the mussel clade Bathymodiolinae (Bivalvia: Mytilidae) have evolved interactions with a higher diversity of bacterial lineages than other bivalve groups. Here, we characterized the bacteria associated with "Bathymodiolus" mauritanicus and Idas-like specimens from three sites in the Northeast Atlantic (two mud volcanoes in the Gulf of Cadiz and one seamount of the Gorringe Bank). Phylo...

  15. 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

  16. 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

  17. Disturbance of shallow marine soft-bottom environments and megabenthos assemblages by a huge tsunami induced by the 2011 M9.0 Tohoku-Oki earthquake.

    Directory of Open Access Journals (Sweden)

    Koji Seike

    Full Text Available Huge tsunami waves associated with megathrust earthquakes have a severe impact on shallow marine ecosystems. We investigated the impact of a tsunami generated by the 2011 M9.0 Tohoku-Oki earthquake on the seafloor and large benthic animals in muddy and sandy ria coasts (Otsuchi and Funakoshi bays in northeastern Japan. We conducted underwater field surveys using scuba equipment in water depths of <20 m before the tsunami (September 2010 and after the tsunami (September 2011 and September 2012. During the study period, episodic changes in topography and grain-size composition occurred on the seafloor of the study area. Megabenthos sampling revealed a distinct pattern of distribution succession for each benthic species. For example, the protobranch bivalve Yoldia notabilis (Bivalvia: Nuculanidae and the heterodont bivalve Felaniella usta (Bivalvia: Ungulinidae disappeared after the tsunami event, whereas the distribution of the venus clam Gomphina melanaegis (Bivalvia: Veneridae remained unchanged. In addition, the patterns of succession for a single species, such as the giant button top shell Umbonium costatum (Gastropoda: Trochidae and the heart urchin Echinocardium cordatum (Echinoidea: Loveniidae, varied between the two bays studied. Our data also show that reestablishment of some benthic animal populations began within 18 months of the tsunami disturbance.

  18. Comportamiento reproductivo y fisiología del lenguado senegalés, (Solea Senegalensis) en cautividad / Reproductive Behaviour and Physiology of Senegalese Sole, (Solea Senegalensis) Broodstock in Captivity

    OpenAIRE

    Carazo Ortega, Ignacio

    2013-01-01

    [spa] En el presente trabajo de tesis doctoral se presenta y describe por primera vez el comportamiento reproductivo del lenguado senegalés (Solea senegalensis) de origen salvaje mantenido en cautividad, trabajando con un total de 15 cortejos. El cortejo del lenguado senegalés se inicia mediante una serie de contactos entre machos y hembras, seguido de una serie de comportamientos de tipo competitivo observados exclusivamente en los machos. Posteriormente un macho centra su atención sobre...

  19. Venezuela: factores claves en el conflicto gobierno-medios

    Directory of Open Access Journals (Sweden)

    Lic. Sebastián de la Nuez Aránega

    2002-01-01

    Full Text Available El siguiente trabajo tiene por finalidad analizar las características del conflicto que desde el principio de su mandato ha mantenido el actual gobierno venezolano con los medios de comunicación en general, conflicto que se ha visto potenciado por la creciente beligerancia de muchos medios, una política comunicacional gubernamental centrada en la personalidad agresiva del presidente y una sentencia del Tribunal Supremo de Justicia sobre el derecho a réplica.

  20. West Nile virus; ecology and epidemiology of an emerging pathogen in Colombia

    OpenAIRE

    Berrocal Almanza, LC; Peña, J.; Gonz?lez, M; Mattar, S

    2006-01-01

    El virus del oeste del Nilo (VON) es mantenido en la naturaleza en un ciclo enzo?tico ave-mosquito-ave. Los principales vectores son los mosquitos del genero Culex. Las aves son los hu?spedes amplificadores primarios. Humanos y caballos son hu?spedes incidentales finales. En humanos las infecciones por VON se presentan como enfermedad febril autolimitada. En los casos de enfermedad neurol?gica se puede presentar encefalitis, meningitis o meningoencefalitis, con mayor incidencia y mortalidad p...

  1. Crónica de la prensa salvadoreña: imaginarios que migran

    OpenAIRE

    Amparo Marroquín Parducci

    2008-01-01

    EL ARTÍCULO PRESENTA UN ESTUDIO DE LAS NARRATIVAS QUE LA PRENSA escrita ha venido construyendo en El Salvador en torno al fenómeno de la migración. Se argumenta que a través del tema de la migración se construye una poética de nación imaginada, y conjuntamente, se da la construcción de las alteridades que desde el discurso oficial se han mantenido vigentes.

  2. Inflamación y envejecimiento del músculo liso. Papel protector de la melatonina

    OpenAIRE

    Gómez Pinilla, Pedro Julián

    2013-01-01

    En la presente tesis se demuestra que el tratamiento con melatonina es efectivo en la recuperación del músculo liso y plexo nervioso de la vejiga urinaria y vesícula biliar de cobaya sometidos a un ligero estrés oxidativo mantenido en el tiempo como ocurre en el envejecimiento, pero también ejerce efectos beneficiosos en estados de mayor agresión oxidativa como la inflamación aguda.

  3. Engaños ópticos y artificios perspectivos

    OpenAIRE

    2014-01-01

    Título de la conferencia: "Engaños ópticos y artificios perspectivos" La conferencia incide en las relaciones que las disciplinas del Arte y la Ciencia han mantenido históricamente a través de la Geometría, tomando como hilo argumental la Perspectiva. Conferencia enmarcada en la asignatura Geometría en el arte. Universidad de Málaga. Campus de Excelencia Internacional Andalucia Tech.

  4. Aspectos reproductivos de la babilla Caiman crocodilus fuscus (Cope 1868, en condiciones de cautiverio

    Directory of Open Access Journals (Sweden)

    González Acosta Julio A.

    1996-06-01

    Full Text Available Observations were made on reproduction parameters of Caiman crocodilus tuscus in confimenet in the farm Saurus Ltd. during two periods of nesting and laying ( years 1992 - 1993 .Se realizaron observaciones sobre parámetros reproductivos en Caimsn crocodilus tuscus mantenidos en cautividad en el zoocriadero Saurus Ltda, durante dos épocas de anidación y postura (años 1992 - 1993.

  5. Nuevas estrategias terapéuticas en diabetes mellitus tipo 1

    OpenAIRE

    Barajas, M. (Miguel); Príncipe, R.M. (R.M.); Escalada, J.; Prosper, F. (Felipe); J. Salvador

    2008-01-01

    El principal determinante del riesgo de complicaciones derivadas de la diabetes mellitus tipo 1 se debe a los altos niveles de glucosa en sangre mantenidos durante largo tiempo. Para conseguir un beneficio terapéutico en pacientes con diabetes mellitus es necesario desarrollar tratamientos que permitan de manera segura, efectiva y estable mantener la normoglucemia. Lamentablemente, el tratamiento de la diabetes mellitus tipo 1 mediante el aporte exógeno de insulina no ...

  6. Nuevas estrategias terapéuticas en diabetes mellitus tipo 1 New therapeutic strategies for type 1 diabetes mellitus

    OpenAIRE

    Barajas, M. (Miguel); Príncipe, R.M. (R.M.); Escalada, J.; Prósper, F; J. Salvador

    2008-01-01

    El principal determinante del riesgo de complicaciones derivadas de la diabetes mellitus tipo 1 se debe a los altos niveles de glucosa en sangre mantenidos durante largo tiempo. Para conseguir un beneficio terapéutico en pacientes con diabetes mellitus es necesario desarrollar tratamientos que permitan de manera segura, efectiva y estable mantener la normoglucemia. Lamentablemente, el tratamiento de la diabetes mellitus tipo 1 mediante el aporte exógeno de insulina no es capaz de conseguir ni...

  7. El «saber artístico» de un antropólogo y el estudio de la cultura en el Perú: A propósito de una obra olvidada de José María Arguedas

    Directory of Open Access Journals (Sweden)

    Juan Javier Rivera Andía

    2011-12-01

    Full Text Available Este breve texto intenta llamar la atención sobre ciertas preguntas en torno al carácter inédito que ha mantenido, por casi medio siglo, un archivo etnográfico acopiado por J. M. Arguedas. Entre ellas, nos preguntamos si tal condición estaría ligada a la forma en que Arguedas concebía el saber de la antropología.

  8. Historia del modelo cosmológico estándar LCDM: la cosmología física tras del modelo del big bang

    OpenAIRE

    2015-01-01

    Desde que el big bang se asentara como modelo cosmológico estándar han pasado 50 años. En este periodo, la cosmología ha mantenido abierta la cuestión de cuál es la evolución del universo y a través de la teoría inflacionaria ha enfrentado el p

  9. Behavioral analysis of Wistar rats fed with a flaxseed based diet added to an environmental enrichment Análisis del comportamiento de ratas Wistar alimentadas con una dieta a base de linaza añadidos a un enriquecimiento ambiental

    Directory of Open Access Journals (Sweden)

    J. Azevedo de Meneses

    2011-08-01

    ó dieta a base de linaza y fué mantenido en ambiente enriquecido; FSEG, que recibió dieta a base de linaza y fué mantenido en ambiente padrón; CEEG, que recibió dieta a base de caseína y fué mantenido en ambiente enriquecido; CSEG, que recibió dieta a base de caseína y fué mantenido en ambiente padrón; MCEEG, que recibió dieta a base de caseína con modificaciones de modo a proporcionar el mismo contenido de fibras y grasa encontrados en la dieta a base de linaza, y mantenido en ambiente enriquecido; MCSEG, que recibió dieta a base de caseína modificada y fué mantenido en ambiente padrón. Todos los animales tubieron temperatura ambiente controlada, jaulas colectivas (n = 3 y ciclo claro/oscuro (12 h, recibiendo água y ración ad libitum, excepto los grupos MCEEG y MCSEG que fueron sometidos a sistema pair feeding con los grupos FEEG y FSEG, respectivamente. El consumo y peso corporal de los animales fué medido dos veces por semana. Los animales fueron mantenidos en sus respectivos grupos a partir del primer mes de vida y hasta el segundo, cuando se inició un período de pruebas en el Open Field Test. Al término de las pruebas se sacrificaron los animales y se retiraron sus cerebros para calcular el peso relativo. Nuestros resultados muestran una interacción entre la linaza y el enriquecimiento ambiental en la habituación a un nuevo ambiente, haciendo que los animales sean mas manipulables y menos nerviosos.

  10. 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.

  11. The first record of the Chinese pond mussel Sinanodonta woodiana (Lea, 1834 in Montenegro

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    Tomović Jelena

    2013-01-01

    Full Text Available Sinanodonta woodiana (Lea, 1834, Chinese pond mussel (Bivalvia: Unionoida: Unionidae is one of the most invasive aquatic macroinvertebrate species found in Europe. We report the Chinese pond mussel for the first time in Montenegro, in August 2012, in Lake Šasko (Adriatic part of the Central Mediterranean subarea. One specimen of the Chinese pond mussel was observed in a habitat with a predominantly silt-clay substrate. The main pathway of species introduction was evaluated to be via fish stocking. [Projekat Ministarstva nauke Republike Srbije, br. III 43002 i br. ON 173025

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

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    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.

  13. New York Bight Study: Report 5, NY Bight Biological Review Program

    Science.gov (United States)

    1994-05-01

    Chapter 3 Step 2: Examining Potential Impacts with Existing Databases and Models 65 material in the Gulf of Mexico . Using trawl and hydroacoustic surveys...48.7 11.3 Pogonophora 2.9 4.7 2.1 Sipunculda 0.6 2.5 1.9 1.9 0.8 Echiura 1.3 0.4 0.3 Mollusca -Gastropoda 0.4 8.3 25.7 39.2 13.4 2.4 Mollusca -Bivalvia...types of information should be integrated into management deci- sions. Over 80 sample stations were located in offshore waters between the Gulf of

  14. [Latin American malacology. Freshwater mollusks from Argentina].

    Science.gov (United States)

    Rumi, Alejandra; Gregoric, Diego E Gutiérrez; Núñez, Verónica; Darrigran, Gustavo A

    2008-03-01

    A report and an updated list with comments on the species of freshwater molluscs of Argentina which covers an area of 2 777 815 km2 is presented. Distributions of Gastropoda and Bivalvia families, endemic, exotic, invasive as well as entities of sanitary importance are also studied and recommendations on their conservation are provided. Molluscs related to the Del Plata Basin have been thoroughly studied in comparison to others areas of the country. This fauna exhibits relatively the biggest specific richness and keeps its affinity with the fauna of other regions of the basin in areas of Paraguay and Brasil. The 4 500 records of molluscs considered in this paper arise from the study of the collections of Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Buenos Aires; Museo de La Plata, La Plata and Fundación "Miguel Lillo", Tucumán. These institutions keep very important collections of molluscs in southern South America. Field information has recently been obtained and localities cited by other authors are also included in the data base. Until today, 166 species have been described, 101 belonging to 10 families of Gastropoda and 65 to 7 of Bivalvia. Families with highest specific richness are Lithoglyphidae (22) and Sphaeriidae (25), respectively. The number of endemic species (those present only in Argentina) by family is: Gastropoda: Ampullariidae (1), Cochliopidae (10), Lithoglyphidae (11), Thiariidae (3), Chilinidae (11), Lymnaeidae (2) and Physidae (2?); Bivalvia: Hyriidae (1?); Etheriidae (1?) and Sphaeriidae (10). Families with a distribution that comprise almost the whole country are: the Sphaeriidae and the gastropods Cochliopidae, Chilinidae and Lymnaeidae. Families Erodonidae and Solecurtidae (Bivalvia) were registered in mixohaline environments from Buenos Aires province. Gastropod families Thiaridae and Glacidorbiidae show a very restricted distribution. The rest of the families are present mainly in the center and north of the country

  15. Struktur komunitas tiram daging di perairan estuaria Kuala Gigieng, Kabupaten Aceh Besar, Provinsi Aceh

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    Chitra Octavina

    2014-08-01

    Full Text Available Tiram daging (Ostreidae merupakan salah satu kerang yang memiliki nilai ekonomi penting bagi masyarakat Kuala Gigieng. Namun, kualitas dan kuantitas tiram menurun akibat eksploitasi dan pencemaran perairan. Penelitian ini bertujuan untuk menganalisis struktur populasi dan kondisi habitat tiram di perairan estuaria Kuala Gigieng Kabupaten Aceh Besar, Provinsi Aceh. Sampling dilakukan pada tiga lokasi selama bulan Agustus hingga September 2013. Hasil penelitian menunjukkan bahwa terdapat dua genus tiram di perairan Kuala Gigieng yaitu Crassostrea dan Ostrea dengan total 5 spesies (C. gigas, C. iridescens, C. angulata, C. virginica and O. edulis. Kepadatan tertinggi berada pada lokasi yang tekanan penangkapan dan lingkungannya yang rendah. Pola penyebaran tiram daging di Kuala Gigieng cenderung mengelompok. Frekuensi ukuran selang kelas tiram terbanyak yang ditemukan yaitu 24-37,20 mm dengan ukuran layak tangkap yaitu 32,27 mm. Pertumbuhan tiram daging di Kuala Gigieng tergolong lambat, hal ini ditunjukkan dengan panjang maksimal (Lmaks yang mampu dicapai kerang ini hanya 37,91-72,81 mm dalam waktu 0-3,42 tahun. secara keseluruhan, struktur populasi tiram daging dan kondisi habitat di Kuala Gigieng mulai menurun. Oleh karen itu, diperluka pengaturan pengelolaan sumberdaya tiram dengan melakukan pengaturan penangkapan, budidaya tiram, dan pembuangan limbah agar sumberdaya tiram di Kuala Gigieng tetap lestari.

  16. Molecular identification, phylogeny and geographic distribution of Brazilian mangrove oysters (Crassostrea)

    Science.gov (United States)

    2010-01-01

    Oysters (Ostreidae) manifest a high degree of phenotypic plasticity, whereby morphology is of limited value for species identification and taxonomy. By using molecular data, the aim was to genetically characterize the species of Crassostrea occurring along the Brazilian coast, and phylogenetically relate these to other Crassostrea from different parts of the world. Sequencing of the partial cytochrome oxidase c subunit I gene (COI), revealed a total of three species of Crassostrea at 16 locations along the Brazilian coast. C. gasar was found from Curuçá (Pará state) to Santos (São Paulo state), and C. rhizophorae from Fortim (Ceará state) to Florianópolis (Santa Catarina state), although small individuals of the latter species were also found at Ajuruteua beach (municipality of Bragança, Pará state). An unidentified Crassostrea species was found only on Canela Island, Bragança. Crassostrea gasar and C. rhizophorae grouped with C. virginica, thereby forming a monophyletic Atlantic group, whereas Crassostrea sp. from Canela Island was shown to be more similar to Indo-Pacific oysters, and either arrived in the Atlantic Ocean before the convergence of the Isthmus of Panama or was accidentally brought to Brazil by ship. PMID:21637433

  17. Levels of Platinum Group Metals in Selected Species (Sarotherodon melanotheron, Chonophorus lateristriga, Macrobrachium vollenhovenii and Crassostrea tulipa in Some Estuaries and Lagoons Along the Coast of Ghana

    Directory of Open Access Journals (Sweden)

    D. K. Essumang

    2010-01-01

    Full Text Available The use of some biota as bioindicators of heavy metal pollution has been demonstrated as particularly adequate due to their capacity of bioconcentration. This study evaluated the levels of platinum group metals (PGMs in some selected species along the coastal belt of Ghana, using the neutron activation analysis (NAA method. The result was processed to evaluate pollution indices in order to map the distribution of the metals in those species in the lagoons and estuaries along the costal belt of Ghana. The analysis showed significant levels of all PGMs in blackchin tilapia (Sarotherodon melanotheron Cichlidae, brown goby (Chonophorus lateristriga Gobiidae, shrimp (Macrobrachium vollenhovenii Palaemonidae, and mangrove oysters (Crassostrea tulipa Ostreidae in the lagoons and river Pra estuary. However, the oysters showed an elevated mean concentration of 0.13 μ/g (dry weight Pd. From the pollution indices, most of the sampling sites registered mean contamination factor (CF values between 1.20 and 3.00 for Pt, Pd, and Rh. The pollution load index (PLI conducted also gave an average pollution index between 0.79 and 2.37, indicating progressive contamination levels. The results revealed that anthropogenic sources, industrial and hospital effluent, etc., together with vehicular emissions, could be the contributing factors to the deposition of PGMs along the Ghanaian coast.

  18. Millennial-scale sustainability of the Chesapeake Bay Native American oyster fishery.

    Science.gov (United States)

    Rick, Torben C; Reeder-Myers, Leslie A; Hofman, Courtney A; Breitburg, Denise; Lockwood, Rowan; Henkes, Gregory; Kellogg, Lisa; Lowery, Darrin; Luckenbach, Mark W; Mann, Roger; Ogburn, Matthew B; Southworth, Melissa; Wah, John; Wesson, James; Hines, Anson H

    2016-06-01

    Estuaries around the world are in a state of decline following decades or more of overfishing, pollution, and climate change. Oysters (Ostreidae), ecosystem engineers in many estuaries, influence water quality, construct habitat, and provide food for humans and wildlife. In North America's Chesapeake Bay, once-thriving eastern oyster (Crassostrea virginica) populations have declined dramatically, making their restoration and conservation extremely challenging. Here we present data on oyster size and human harvest from Chesapeake Bay archaeological sites spanning ∼3,500 y of Native American, colonial, and historical occupation. We compare oysters from archaeological sites with Pleistocene oyster reefs that existed before human harvest, modern oyster reefs, and other records of human oyster harvest from around the world. Native American fisheries were focused on nearshore oysters and were likely harvested at a rate that was sustainable over centuries to millennia, despite changing Holocene climatic conditions and sea-level rise. These data document resilience in oyster populations under long-term Native American harvest, sea-level rise, and climate change; provide context for managing modern oyster fisheries in the Chesapeake Bay and elsewhere around the world; and demonstrate an interdisciplinary approach that can be applied broadly to other fisheries.

  19. Habitat Suitability Index Models: Gulf of Mexico American Oyster

    Science.gov (United States)

    Cake, Edwin W.

    1983-01-01

    The American or eastern oyster (Crassostrea virrinica [Gmelin]), a bivalve in the family Ostreidae, is an important commercia and recreational species along the Atlantic and Gulf of Mexico coasts of North America and other areas (U.S. Pacific coast and Hawaii) where it has been introduced (Galtsoff 1964). It evolved over the last 25 million years (Miocene and Pliocene epochs) from an ancestral, Atlantic-Pacific species that also gave rise to the Central American oyster of the Pacific coast, Crassostrea corteziensis (Hertlein) (Stenzel 1971). It evolved to fill a eurytopic niche in coastal estuaries where it forms massive reefs in nearshore bays, sounds, lagoons, and river mouths. Its existence depends on suitable substratum (cultch and firm bottom sediments) and acceptable sal-inity conditions. The location and distribution of oyster reefs in a salt marsh-estuari ne ecosystem are not acci denta 1; rather, they result from the interacti on of many bi 01 ogi ca 1, chemica1, geo1ogi ca1, and phys i ca 1 processes (Butler 1954a; Marshall 1954; Bahr and Lanier 1981).

  20. TRANSGRESSIVE SEQUENCES ON FORELAND MARGINS: A CASE STUDY OF THE NEOGENE CENTRAL GUADALQUIVIR BASIN, SOUTHERN SPAIN

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    J. GABRIEL PENDÓN

    2004-07-01

    Full Text Available The Guadalquivir foreland basin, located between the Iberian basement northward and the Betic orogen to the South, represents the western sector of the earlier foredeep basin of the Betic Cordillera. Along the northern foreland margin, the sedimentary fill of this basin includes a Tortonian Basal Transgressive Complex (BTC, composed of five internal sequences bounded by transgressive surfaces. Two main parts are distinguished within each sequence: the lower transgressive lag deposits, and the upper stillstand/prograding sediments. Three facies associations were distinguished within this stratigraphic succession along the central sector of this basin margin: unfossiliferous conglomerates and coarse-grained sands (A, fossiliferous conglomerates and coarse-grained sands (B, and yellow medium-coarse-grained fossiliferous sands (C. A fourth facies association (D: blue silty marlstones and shales overlies the BTC. Deposits of alluvial sediments (facies association A and shallow-marine/foreshore sediments (facies association C, were recurrently interrupted by transgressive pulses (facies associations B and C. Every pulse is recorded by an erosional, cemented sandy-conglomerate bar with bivalves (Ostreidae, Isognomon, balanids, gastropods and other marine bioclasts; or their transgressive equivalents. The lateral facies changes in each individual sequence of the BTC are related to: (1 the influence on the northern foreland margin of the tectonic activity of the southern orogenic margin; (2 the palaeorelief formed by irregularities of the substrate which controls the sediment dispersal; and (3 the evolution stages of the sedimentary systems. 

  1. Prevención de úlceras por presión y lesiones musculoesqueléticas: paciente con ictus

    OpenAIRE

    Rodríguez Pappalardo, Fátima; Luque Moreno, Carlos; Peña Salinas, Marta; López Rodríguez, Luis

    2012-01-01

    Planteamos un caso clínico en el que enfermera y fisioterapeuta ponen en común procedimientos para mejorar la higiene postural de un paciente encamado con un accidente cerebrovascular y hemiplejia izquierda. Describimos analíticamente una intervención conjunta durante un mes. A pesar de que se ha mantenido el riesgo máximo de UPP objetivado inicialmente, durante este periodo no han aparecido úlceras, obteniendo un mantenimiento o aumento del rango de las articulaciones. Es impo...

  2. TASAS DE CONCEPCIÓN, FERTILIDAD Y PROLIFICIDAD EN OVEJAS DE PELO ALIMENTADAS CON DIETAS ENRIQUECIDAS CON ÁCIDOS GRASOS POLIINSATURADOS

    OpenAIRE

    G Cansino-Arroyo; J Herrera-Camacho; JR Aké-López

    2009-01-01

    Las tasas de concepción, de fertilidad y prolificidad fueron evaluadas en ovejas de pelo distribuidas al azar en: un grupo testigo que recibió 800 g MS de un concentrado comercial, un grupo melaza (n = 51) alimentado con 717.6 g MS del concentrado comercial + 80.25 g MS de melaza y un grupo aceite (n = 85) mantenido con 726.8 del concentrado comercial + 30.0 g de aceite de maíz como fuente de ácidos grasos poliinsaturados. Las tasas de concepción y fertilidad fueron similares entre los tratam...

  3. Efectos de la alcalosis metabólica inducida por la dieta en el rendimiento anaeróbico de alta intensidad Effects of the metabolic alkalosis induced by the diet in the high intensity anaerobic performance

    OpenAIRE

    O. Ríos Enríquez; Guerra-Hernández, E.; B. Feriche Fernández-Castanys

    2010-01-01

    Objetivos: El propósito principal de este estudio es comparar el efecto de una alcalosis y acidosis inducidas por la dieta sobre el rendimiento en un esfuerzo anaeróbico láctico mantenido. Métodos: Para ello, trece sujetos activos se sometieron de forma cruzada a sendas dietas durante dos días y medio. Inmediatamente después realizaron una prueba de esfuerzo anaeróbica láctica máxima de estado estable hasta el agotamiento sobre cicloergómetro a 250 W. Resultados: La valoración de las dietas m...

  4. RELACIONES ENTRE EL APARATO DE GOLGI Y LA MITOSIS: PAPEL DE LA GOLGINA P115 EN LA ACTIVACION DE CDK1 Y EL PUNTO DE CONTROL G2/M D ELA MITOSIS EN DROSOPHILA

    OpenAIRE

    Ibar ValenZuela, MARÍA CONSUELO

    2013-01-01

    Las células eucariontes tienen organelos derivados de membrana dentro de los cuales se encuentra el retículo endoplasmático y el aparato de Golgi, los cuales les permiten separar y organizar las distintas funciones celulares. Estos organelos tienen que ser mantenidos en las células hijas durante la división celular, generando las preguntas: ¿qué ocurre cuando las células se dividen? ¿se dividen los organelos existentes o nuevas copias son generadas? ¿cómo esto se encuentra acop...

  5. La eficacia escolar y otros resultados de la enseñanza secundaria: tres décadas de investigación británica

    OpenAIRE

    Gray, John

    2006-01-01

    Por mucho tiempo se ha mantenido el supuesto de que las escuelas eficaces respecto a algún aspecto (generalmente desempeño académico) eran también más eficaces en otros aspectos. Este artículo revisa las últimas tres décadas de investigaciones británicas que han analizado la eficacia de las escuelas a través de una amplia variedad de aspectos afectivos, sociales y otros aspectos no cognoscitivos, entre los que se incluyen: la actitud de los estudiantes ante la escuela, sus niveles de implicac...

  6. La secularización del poder durante el Imperio Nuevo egipcio : La epifanía real en la ventana de aparición

    OpenAIRE

    Pereyra de Fidanza, Maria Violeta

    2015-01-01

    La segunda mitad de la dinastía 18 ha sido uno de los períodos de la historia del antiguo Egipto abordado con mayor frecuencia por los egiptólogos. Por décadas, el reinado de Amenhotep IV / Ajenatón, su revolución religiosa y su arte naturalista ejercieron una extraordinaria atracción por parte de historiadores e historiadores del arte que se ha mantenido hasta el presente. Más que cualquier otro momento de la historia de Egipto, el período de...

  7. H??bitos de vida saludable en la poblaci??n universitaria

    OpenAIRE

    S??nchez-Ojeda, Mar??a Angustias; Luna-Bertos, Mar??a Elvira de

    2015-01-01

    El estilo de vida se define como el conjunto de pautas y h??bitos comportamentales cotidianos de una persona, que mantenidos en el tiempo pueden constituirse en dimensiones de riesgo o de seguridad dependiendo de su naturaleza. Los objetivos del presente trabajo han sido conocer los estilos de vida de los j??venes universitarios en las siguientes dimensiones: alimentaci??n, ejercicio f??sico, consumo de tabaco, alcohol y otras drogas, relaciones sexuales y seguridad vial. Para ello se ha real...

  8. Valoración de la fatiga neuromuscular en el antebrazo del motorista de velocidad

    OpenAIRE

    Torrado Pineda, Priscila

    2015-01-01

    Actualmente, es frecuente ver cómo muchas escuderías tienen sus motos paradas en boxes por patologías neuromusculares de sus pilotos oficiales, debiendo recurrir a pilotos substitutos. Durante una carrera de motos la fatiga es alta porque los pilotos tienen que soportar niveles de tensión muscular elevados, particularmente en los brazos y antebrazos y además mantenidos durante un largo periodo de tiempo. Un estudio previo realizado durante una carrera de resistencia de 24 h (Marina,...

  9. La interferencia de las patentes en el ejercicio del derecho de libertad de investigación

    OpenAIRE

    Wong Ramírez, Sulan Cristina

    2013-01-01

    [Resumen]La patente, en el discurso de los derechos de propiedad intelectual, es defendida como un instrumento que incentiva el desarrollo científico, beneficiando a la sociedad al generar productos y servicios útiles que mejoran la calidad de vida de las personas. Esta concepción, deudora del relato jurídico-político moderno, se ha mantenido inalterable en el tiempo. Sin embargo, la patente, al otorgar derechos exclusivos de explotación, crea situaciones que interfieren en el ejercicio de la...

  10. POR UNA POLÍTICA FISCAL CONTRACÍCLICA

    OpenAIRE

    Eduardo Ramírez Cedillo

    2006-01-01

    La postura fiscal de las economías latinoamericanas y de muchas en desarrollo ha mantenido un carácter procíclico que ha jugado un papel importante en la inestabilidad que observan éstas, a diferencia de lo que sucede en los países desarrollados, que utilizan su política fiscal para atenuar las presiones del ciclo económico. A este respecto, en este trabajo se vierten algunas explicaciones, como: la exposición a la volatilidad de los capitales financieros y el uso inadecuado de la política de...

  11. Historia geopolítica de las enfermedades en Colombia

    Directory of Open Access Journals (Sweden)

    Hugo Armando Sotomayor

    2009-07-01

    sociales del país, el racismo, cargado de desprecio y subvaloración de lo "indio" y lo ~negro", y las guerras, de conquista, entre potencias coloniales, de Independencia, de defensa nacional y civiles, no pueden entenderse en toda su extensión si se estudian aisladamente. Ellos deben ser asociados, en su génesis y continuidad, a la historia de los intereses del poder político, social y de dominio territorial que introdujo el imperio español y a los que se han mantenido durante toda la vida republicana.

  12. Clinton-Lewinsky: el escándalo que comenzó en la Red

    Directory of Open Access Journals (Sweden)

    Dra. Claudia Quadros

    1999-01-01

    Full Text Available Internet fue el medio usado para publicar las primeras informaciones y rumores sobre la historia de que Mónica Lewinski, becaria de la Casa Blanca, había mantenido relaciones sexuales con el presidente de Estados Unidos, Bill Clinton. Matt Drudge, un periodista responsable de la edición de un panfleto digital sin credibilidad llamado 'The Drudge Report' (http://www.drudgereport.com fue el primero en difundir el escándalo. El hecho tuvo lugar el 18 de enero de 1998.

  13. Diseño de un sistema de buenas prácticas de manufactura en

    OpenAIRE

    Sánchez Vásquez, Viviana Lorena; Decker Campuzano, Fernando Enrique

    2010-01-01

    Hace ya más de 60 años, abre sus puertas a sus clientes la empresa familiar LA DELICIA dedicada a la elaboración de una gran variedad de panes, dulces y tortas. La misma se ha mantenido entre las más importantes del sector debido al distintivo toque de sabor y apariencia artesanal de sus productos. En el transcurso de los años la empresa ha ido creciendo a tal punto que hoy en día ha pasado de ser una panadería artesanal de barrio como lo fue en sus orígenes, para convert...

  14. Galicia Clínica. Informe de los editores

    Directory of Open Access Journals (Sweden)

    Rafael Monte Secades

    2012-12-01

    Full Text Available En el año 2008, la revista Galicia Clínica retomó su actividad, interrumpida en 1996 después de 65 años de vida editorial. La Sociedad Gallega de Medicina Interna (SOGAMI, en su XXV aniversario, planteó la recuperación de la revista, con la que los internistas habían mantenido una estrecha relación en su prime-ra etapa, a nivel particular como medio de formación continuada, e institucional al servir de vehículo para la publicación de comunicaciones a sus congresos.

  15. Comportamiento reproductivo y fertilidad de Macrobrachium carcinus (Decapoda: Palaemonidae) en Venezuela

    OpenAIRE

    2016-01-01

    El camarón "gigante" de agua dulce Macrobrachium carcinus se encuentra presente en Venezuela tanto en puequeflos ríos litorales como en ríos más caudalosos. En el presente trabajo, seis machos y 22 hembras capturados en el río Manzanares del Edo. Sucre, fueron mantenidos durante 14 meses en el laboratorio con el objeto de hacer observaciones sobre el proceso de muda, apareamiento, desove, período de incubación, eclosión de los huevos y número de zonas/hembra. De los 33 procesos de muda observ...

  16. Evaluación del proceso de gestión de calidad en las fábricas procesadoras de queso del municipio de Belén: aplicación a la estandarización del proceso de producción Planta Ibel.

    OpenAIRE

    Santoyo Ardila, Rocío Himelda

    2011-01-01

    La apertura económica y la globalización es cada vez más exigente con la calidad tanto de los productos como de los servicios. En los mercados locales y regionales como en la ciudad de Belén (Boyacá), se evidencia este problema en las agroindustrias procesadoras de queso, debido a que se conformaron como empresas familiares y se han mantenido así elaborando los productos de manera empírica sin que se realicen investigaciones ni mejoras lo que podría generar una salida del mercado debido a la ...

  17. Sensibilización y tolerancia a la violencia de parejas de novios en relaciones de noviazgo universitarias

    OpenAIRE

    Rodríguez Franco, Luis; Rodríguez Díaz, Francisco Javier; Antuña Bellerín, María de los Ángeles; López-Cepero Borrego, Javier

    2010-01-01

    En nuestro estudio, se analiza la sensibilización y tolerancia a la violencia de pareja en estudiantes mujeres de entre 16 y 25 años que cursan sus estudios universitarios. El único requisito adicional para la formación de la muestra ha sido el haber mantenido una relación de noviazgo de, al menos, un mes de duración. La muestra se compone de un total de 1079 sujetos de las Universidades de Sevilla, Asturias, Huelva, A Coruña y Vigo a quienes se aplicó el Cuestionario de Violen...

  18. Pobreza, movimiento social y mujer

    OpenAIRE

    Elsa Patiño Tovar

    2005-01-01

    Los movimientos sociales en Puebla se han nutrido ampliamente de la participación de las mujeres; sobre todo, cuando hablamos de las organizaciones populares independientes (OPI). Su participación ha mantenido vivas a muchas organizaciones que de otra manera habrían desaparecido ya, pues no sólo participan en las tareas cotidianas de la organización sino, también, son las primeras en dar la cara cuando hay enfrentamientos con el gobierno y sus organizaciones corporativas, en do...

  19. No innovar el orden andino según el licenciado Polo

    OpenAIRE

    Sosa Miatello, Sara

    2014-01-01

    Se analiza la obra del licenciado Juan Polo de Ondegardo, con énfasis en la llamada Relación de 1571 cuya propuesta busca no innovar,en lo posible, el orden andino. Así,sugiere Polo mantener costumbres y leyes preexistentes a la llegada de los españoles, pues solo de ese modo podrían conciliarse los intereses tanto de gobernantes como de gobernados. Por ejemplo, esto es claro en la concepción que tiene dicho personaje del sistema tributario y del régimen de caciques que -mantenidos en esencia...

  20. Metodología para el estudio de la regulación del peso corporal y/o de la etiología de la obesidad

    OpenAIRE

    A. Marti; Martinez, J. A.

    2002-01-01

    La obesidad, uno de los más graves problemas de salud de las sociedades desarrolladas, es el resultado de un balance energético positivo mantenido en el tiempo. La regulación del peso corporal y su mantenimiento parece estar regulado por un eje con tres componentes interdependientes: la ingesta dietética, el gasto energético y la adipogénesis, aunque es preciso profundizar en los procesos que intervienen tanto en la oxidación de nutrientes como en el balance energético. Los procesos metabólic...

  1. Informe Mesa de Comunicaciones 11. Docencia y Evaluación: Reflexiones y Nuevas Propuestas

    OpenAIRE

    IRLES PARREÑO, RICARDO

    2014-01-01

    El Informe tiene como objetivo presentar, unificar y sintetizar las comunicaciones presentadas en la Mesa nº 11 de las XII Jornadas de Redes de Investigación en Docencia Universitaria celebradas en el curso académico 2013-2014 en la Universidad de Alicante y que han tenido por título genérico “El reconocimiento docente: Innovar e investigar con criterios de calidad” Asimismo pretendemos recoger el debate mantenido a la finalización de la mesa entre los asistentes y ponentes.

  2. Efecto de la mutación en el Gen Halotano sobre los inductores de contracción muscular a lo largo de la tenderización temprana. Papel del género

    OpenAIRE

    Pérez Martínez, Zulema

    2015-01-01

    La carne de cerdo es uno de los alimentos más consumidos. Para ello es necesario asegurar que la carne tiene una buena calidad y que el animal haya mantenido un bienestar adecuado. Para la realización de este proyecto se usaron 24 cerdos [(Large White x Landrace) x Pietrain],que fueron divididos en machos normales, machos portadores del gen halotano, hembras normales y hembras portadoras del gen halotano (6cerdos/grupo). Se criaron en una granja experimental donde fueron destetados a los 28 d...

  3. La cocina de Pozuzo como eje central de una ruta gastronómica para su desarrollo turístico

    OpenAIRE

    Morcia Rivera, Frida Lina

    2013-01-01

    En la provincia de Oxapampa, departamento de Pasco, está ubicado el distrito llamado Pozuzo, cuyos pobladores de origen austro-alemán han hecho de este lugar una interesante propuesta para disfrutar de una cultura suspendida en el tiempo —donde la tradición se ha mantenido a través de más de un siglo— y de un turismo no convencional muy especial vinculado directamente a la naturaleza en la cual, aprovechando las tendencias actuales, sería posible el desarrollo de otras modalidades de turismo ...

  4. Actuaciones del Laboratorio de Genética Bioquímica (LAGENBIO) de la Universidad de Zaragoza encaminadas a la conservación y mejora genética de las razas bovinas explotadas en Aragón, Parda de Montaña, Pirenaica y Serrana de Teruel en colaboración con las asociaciones de ganaderos ARAPARDA, ASAPI y ASERNA

    OpenAIRE

    Sanz, Ariadne; Cons, C.; Banzo, P.; Buisán, M.; Casasús Pueyo, Isabel; Macarulla, J.M.; Marín, J; Naval, C.; Sanz Pascua, Albina; Martín Burriel, Inmaculada; Rodellar Penella, Clementina; Zaragoza, Pilar

    2015-01-01

    El Laboratorio de Genética Bioquímica (LAGENBIO), perteneciente a la Facultad de Veterinaria de la Universidad de Zaragoza ha llevado a cabo durante más de una década acciones encaminadas a la conservación y mejora genética de las razas bovinas Parda de Montaña, Pirenaica y Serrana de Teruel explotadas en Aragón. Para ello ha mantenido convenios y contratos de colaboración con las asociaciones de criadores de las razas bovinas ARAPARDA (Asociación de Criadores de Raza Bovina ...

  5. Buenos Aires maraîchère : une Buenos Aires bolivienne ? Le complexe maraîcher de la Région métropolitaine à l'épreuve de nouveaux acteurs

    OpenAIRE

    Le Gall, Julie

    2011-01-01

    Buenos Aires hortícola: ¿una Buenos Aires boliviana? El complejo hortícola de la Región metropolitana a prueba de nuevos actores Resumen: Al estudiar el caso de Buenos Aires, esta tesis se interesa por la conservación de espacios de proximidad para alimentar las metrópolis: a pesar de presiones metropolitanas fuertes, la capital argentina ha mantenido sus espacios de producción y comercialización para abastecer en hortalizas frescas a sus 13 millones de habitantes. Siguiendo una línea reflexi...

  6. Leslie C. Gates, Electing Chávez. The Business of Anti-Neoliberal Politics in Venezuela, Pittsburg, University of Pittsburg Press, 2010, 195 p. 

    OpenAIRE

    Langue, Frédérique

    2010-01-01

    La génesis de la Quinta República se ha interpretado con frecuencia tanto dentro como fuera del ámbito universitario, como el resultado del fracaso final del sistema de partidos heredado del pacto de Punto Fijo, de las llamadas "políticas públicas" y de las instituciones afines. Pese a las relaciones que el primer presidente antiliberal de la región ha mantenido ocasionalmente con interlocutores del mundo empresarial y financiero, nunca se había contemplado sin embargo la naturaleza y mucho m...

  7. Relación interprofesional entre el personal médico y de enfermería en cuatro unidades de cuidados críticos del HUCA

    OpenAIRE

    Álvarez Riesgo, Judith

    2013-01-01

    INTRODUCCIÓN: Según diversos estudios, una fluida relación entre los profesionales de enfermería y medicina tiene múltiples ventajas, por el contrario, en un ambiente sanitario donde la colaboración es mínima, aumentan las incidencias. A pesar de trabajar en el mismo entorno, los obstáculos entre estos profesionales siempre han sido evidentes, de hecho han mantenido en cuantiosas ocasiones relaciones de dominación, indiferencia o incomprensión mutua. En el pasado las relaciones entre el perso...

  8. Vigilancia centinela para el virus del oeste del nilo en culicidos y aves domésticas en el departamento de Córdoba

    OpenAIRE

    Manolo Jaramillo; José Peña; Luis Berrocal; Nicholas Komar; Marco González; César Ponce; Katiuska Ariza; Salim Máttar

    2005-01-01

    El virus del Oeste del Nilo (VON) género Flavivirus, familia Flaviviridae, es mantenido en la naturaleza en un ciclo enzoótico ave-mosquito-ave. Las aves son los hospederos amplificadores primarios. Humanos y caballos son hospederos incidentales finales. En humanos las infecciones se manifiestan como enfermedad febril autolimitada. También puede presentarse encefalitis o meningoencefalitis. El virus se ha establecido en Norte América y se ha documentado su circulación en México, Jamaica, Repú...

  9. Masculinidad y poder

    OpenAIRE

    Menjívar Ochoa, Mauricio

    2015-01-01

    El trabajo aborda la masculinidad en el marco de las relaciones de poder, partiendo de la perspectiva de aquellos estudios sobre masculinidad ubicados en una perspectiva crítica de la masculinidad hegemónica. Para tales efectos, se parte de la importancia de inscribir el tema de la masculinidad y el poder dentro de los estudios de género, señalando los mecanismos con los que el patriarcado ha generado la hegemonía de los hombres: el consenso y la coacción, mediante los cuales se ha mantenido ...

  10. Asma inducida por el ejercicio.

    OpenAIRE

    Laurencena, Soledad

    2010-01-01

    El asma inducido por el ejercicio es una sensación de dificultad respiratoria, con la presencia de tos, sibilancias y opresión torácica tras realizar un esfuerzo físico. Sería el broncoespasmo transitorio que ocurre tras un ejercicio mantenido de tres a ocho minutos de duración al ochenta por ciento o más de la frecuencia cardíaca máxima. Se realizó un estudio transversal, descriptivo no experimental, tomando una muestra de 100 personas, entre 14 y 18 años, que estudian el ...

  11. Succinilcolina versus Rocuronio, escogencia clínica mediante un análisis de decisión médica / Succinylcholine vs. Rocuronium, clinical choice through a medical analysis decision

    OpenAIRE

    Luquetta Berrío, Jorge Armando

    2010-01-01

    La discusión sobre la escogencia del relajante muscular en la inducción de secuencia rápida, se ha mantenido vigente. Rocuronio al igual que Succinilcolina son relajantes musculares eficaces y con producción también de efectos adversos importantes, características que influyen de manera importante en su uso. Los análisis de decisión ayudan a la escogencia de la mejor opción al asignarle utilidades a estas características, y de esta forma se toma la decisión más consecuente. Objetivo: realizar...

  12. Crónica de la prensa salvadoreña: imaginarios que migran

    Directory of Open Access Journals (Sweden)

    Amparo Marroquín Parducci

    2008-08-01

    Full Text Available EL ARTÍCULO PRESENTA UN ESTUDIO DE LAS NARRATIVAS QUE LA PRENSA escrita ha venido construyendo en El Salvador en torno al fenómeno de la migración. Se argumenta que a través del tema de la migración se construye una poética de nación imaginada, y conjuntamente, se da la construcción de las alteridades que desde el discurso oficial se han mantenido vigentes.

  13. La orientación Fraga: asilos policiales para la reclusión de niños pobres, abandonados y "viciosos" : Buenos Aires, primera década del siglo XX

    OpenAIRE

    Freidenraij, Claudia

    2014-01-01

    Desde fines del siglo XIX la Policía tuvo la iniciativa de regentear los establecimientos correccionales de menores e, incluso, fantaseó con la idea de fundar y sostener sus propios reformatorios. En 1899 la Jefatura alentaba en las páginas de su Revista la creación de “una casa de corrección” para menores que oficiara, a la vez, de escuela de primeras letras, de artes y oficios, en la cual serían “alojados, mantenidos y educados todos los niños púberes y adolescentes que se recogieran en la ...

  14. El mito de Greta Garbo en la Literatura Española e Hispanoamericana

    OpenAIRE

    Portela Lopa, Antonio

    2013-01-01

    [ES] El presente trabajo analiza el impacto literario del mito de Greta Garbo desde una óptica panhispánica. Aborda no sólo su constitución en mito como una unidad de significado organizada por el hecho fílmico y cinematográfico, sino también por la literatura. Se ha dividido en distintos modelos, conformados por aportaciones de las teorías fílmicas y literarias focalizadas en su mayor parte en los procesos de recepción. Aunque se ha mantenido la especificidad de los códigos que form...

  15. La programación neurolingüística (PNL) con adolescentes migrantes. Investigación diagnóstica y propuesta de intervención con PNL en la elaboración del duelo migratorio

    OpenAIRE

    Polanco Estibález, Adriana

    2016-01-01

    La programación neurolingüística (PNL) es una metodología de intervención con personas y grupos, aplicada en ámbitos tales como la educación reglada y organizaciones sociales. Sin embargo, convendría valorar su utilidad en entornos educativos no formales. Dadas sus sólidas bases y su interés mantenido, este trabajo estudia la aplicación y los beneficios de la PNL en adolescentes migrantes que están elaborando su duelo migratorio apoyados por el Servicio Educativo Intercultural ...

  16. El procurador: capacidad de postulación. El ius postulandi. Código deontológico.

    OpenAIRE

    Roldán Pérez, Luis

    2015-01-01

    Comienza la conferencia integrando la figura del Procurador en el Derecho Romano marcando brevemente el iter que ha ido sufriendo esta figura a lo largo de la Historia y destacando la importancia de la institución y que, por su necesidad y conveniencia, la ha mantenido vigente aunque con sus adaptaciones a la vida jurídica y social actual. Destaca en un segundo momento, las funciones que en la actualidad competen al Procurador y su responsabilidad en sus tres parcelas, la civil, la penal...

  17. Apuntes al estudio del dragón como elemento festivo en Oriente y Occidente : China y España

    OpenAIRE

    Sánchez Beltrán, Juan Pablo

    2008-01-01

    Los dragones son animales mitológicos que aparecen tanto en las culturas orientales, como en las Occidentales; sin embargo, mientras que en Oriente son considerados unos animales benefactores y por lo tanto deben ser cuidados, en Occidente simbolizan el mal y por ello deben ser combatidos. El dragón ha sido representado en ambas culturas y su figura se ha mantenido con el paso de los años, llegando a ser un elemento imprescindible en muchas celebraciones civiles y religiosas. En la actualidad...

  18. Incidencia de agenesia dental en perros Beagle. Resultados preliminares(Dental agenesis incidence in Beagle dogs. Preliminary results)

    OpenAIRE

    Rodríguez Sosa; Cabrera García, A; Domínguez López, HA; Soca Pérez, M; Purón Guzméli, CA; Macías Hernández, I; Gil Díaz, F; Aliaga Aleaga, Y; Guerrero Contreras, M; Acosta Berbes, A

    2011-01-01

    ResumenEn el presente trabajo se examinaron 49 perros Beagle procedentes del CENPALAB que fueron mantenidos bajo el mismo régimen de convivencia, alimentación y manejo en el Bioterio de la Facultad de Medicina “Victoria de Girón” tributarios todos a estudios de implantes dentales.AbstractForty-nine Beagle dogs coming from CENPALAB were maintained under the same coexistence, feeding and handling regime in the Bioterio of Medicine High School “Victoria de Girón” tributary to studies of dental i...

  19. Sobre los textos y sus derechos en la Biblioteca virtual 'Miguel de Cervantes' en la Universidad de Alicante

    Directory of Open Access Journals (Sweden)

    Rovira, José Carlos

    2001-05-01

    Full Text Available Cercanos ya a los dos años de su inauguración, quiero reflexionar en este artículo sobre la cuestión de derechos de autor en una Biblioteca Virtual, a partir de la experiencia que nosotros mismos hemos tenido. Mi marco de reflexión no es jurídico, aunque por supuesto parto de la Ley de Propiedad Intelectual, y del respeto escrupuloso a la misma que la biblioteca ha mantenido en su desarrollo. Hoy, más de cinco mil textos literarios en la red, junto a otros muchos recursos, avalan nuestra experiencia.

  20. Integración financiera regional en la zona Asia Pacífico

    OpenAIRE

    2011-01-01

    La integración regional se ha reforzado como parte de las respuestas defensivas ante la crisis financiera internacional. En la región del Asia Pacífico se ha mantenido el avance de proyectos de integración financiera que incluyen mecanismos de intercambio de divisas, sistemas de información y supervisión de políticas económicas, hasta debates académicos sobre integración profunda en uniones monetarias y moneda común. Los acuerdos y propuestas de integración entre los países del Asia Pacífico ...

  1. LA LIGA COMUNISTA 23 DE SEPTIEMBRE 1973-1981. HISTORIA DE LA ORGANIZACIÓN Y SUS MILITANTES

    OpenAIRE

    Rangel Hernández, Lucio

    2012-01-01

    La situación actual de la sociedad mexicana no puede entenderse al margen del complejo proceso armado que ha vivido el país desde el 23 de septiembre de 1965. Desde esa fecha y hasta nuestros días, de acuerdo con Carlos Montemayor y Verónica Oikión la guerrilla rural y la urbana han mantenido ciclos de recurrencia y latencia.1 Desde entonces, hasta el presente, la respuesta del Estado ha sido casi exclusivamente militar, tendiente a aniquilar a los grupos armados. No ha existid...

  2. DINÁMICA DE LA ESTRUCTURA DEL SECTOR HOTELERO EN IBIZA Y FORMENTERA 1960-2000

    Directory of Open Access Journals (Sweden)

    Joan Carles Cirer Costa

    2010-01-01

    Full Text Available En este artículo se analiza la evolución de la estructura empresarial del sector del alojamiento turístico en Ibiza y Formentera entre los años 1960 y 2000, utilizando el instrumental propio de la Economía Industrial. El primer objetivo consiste en comprobar si han aparecido estructuras de tipo oligopolístico o si se ha mantenido el elevado nivel de competitividad inicial. La conclusión es que a lo largo de los 40 años contemplados el sector ha crecido con enorme rapidez, pero manteniendo una estructura competitiva y abierta.

  3. Epidemiología de la diabetes mellitus de tipo 1 en menores de 15 años en Aragón (1991-2010)

    OpenAIRE

    Conde Barreiro, Santiago; Rodríguez Rigual, Mercedes; Bueno Lozano, Gloria

    2013-01-01

    La diabetes mellitus (DM) es un trastorno endocrino-metabólico crónico caracterizado por un aumento mantenido de los niveles de glucosa en sangre. La diabetes mellitus tipo 1 (DM1) es la forma más común en la edad pediátrica, y constituye en los países desarrollados la segunda enfermedad crónica más frecuente en la infancia, y supone un importante problema de Salud Pública a nivel mundial que exige recursos adecuados para su manejo e investigación. Durante los últimos años se han coordinado ...

  4. Uso medicinal de las plantas por los otomíes del municipio de Nicolás Flores, Hidalgo, México

    OpenAIRE

    A. Sánchez-González; D. Granados-Sánchez; R. Simón-Nabor

    2008-01-01

    El conocimiento de las plantas medicinales por los otomíes (hñähñü) de Nicolás Flores, Hidalgo se ha mantenido a través de las generaciones. La influencia de la medicina alópata está restringida principalmente a la prevención de enfermedades como poliomielitis, sarampión, viruela y paludismo. La medicina tradicional es más viable ante las condiciones socioeconómicas, fisiográficas y culturales en esta región. El objetivo de este estudio fue identificar las especies de plantas que utilizan los...

  5. Estudio de la pérdida dental en pacientes diagnosticados de periodontitis, tratados y controlados con terapia periodontal de soporte

    OpenAIRE

    Estefanía Fresco, Ruth

    2016-01-01

    173 p. Los objetivos son analizar la pérdida dental en los pacientes diagnosticados de periodontitis crónica o agresiva, tratados y mantenidos durante un mínimo de 5 años, así como reconocer cuáles son los factores de riesgo involucrados en la pérdida dental en estos pacientes. Para ello se diseñó un estudio retrospectivo y observacional, con un tamaño muestral de 175 pacientes. Los datos se recogieron revisando la historia clínica y los registros radiográficos, mediante una entrevista con...

  6. DELEUZE, Gilles (2014), Michel Foucault y el poder, Viajes iniciáticos I, trad. Javier Palacio Tauste, Errata naturae, Madrid, 168 pp.

    OpenAIRE

    2014-01-01

    Durante el curso 1985-1986 en la Universidad de París 8, Vincennes-Saint Denis, Deleuze imparte clases sobre Foucault, con quien había mantenido amistad. Tras la muerte de Foucault, Deleuze considera que no hay mayor homenaje que leer y releerle, y a lo largo de las tres lecciones que se hallan en el presente volumen explica sus lecturas, es decir, expone la manera en que ha de leerse a Foucault y cómo ha de entenderse la transición del saber al poder, tema central que aborda desde la obra de...

  7. Análisis genómico de girasol: desarrollo de colecciones de ESTs y de una plataforma bioinformática para estudios de expresión de genes candidato en respuestas a estreses abióticos

    OpenAIRE

    Fernández, Paula del Carmen

    2006-01-01

    El girasol es uno de los principales cultivos oleaginosos del mundo por su volumen de producción y composición en ácidos grasos insaturados. En promedio, durante los últimos cinco años, la producción mundial se ha mantenido estable concentrándose el 72% de la misma entre Argentina y la Unión Europea. A pesar de esto y debido a las condiciones de los precios internacionales y la productividad comparativa con otros cultivos, el área de producción se está desplazando a regiones más áridas a nive...

  8. Segmentación y clasificación de las universidades en Chile: desventajas de inicio y efectos de las políticas públicas de financiamiento

    OpenAIRE

    Améstica Rivas,Luis; Gaete Feres, Héctor; Llinas-Audet,Xavier

    2014-01-01

    El presente trabajo examina cómo las políticas públicas de financiamiento destinado a las universidades estatales y privadas del Consejo de Rectores (CRUCH) en Chile han generado una segmentación económica y territorial, debido a la focalización de recursos económicos entregados históricamente a cada una de las instituciones, bajo instrumentos de financiamiento que se han mantenido por más de treinta años en el sistema, independientemente de las coaliciones y políticas gobernantes. Un análisi...

  9. NUEVOS AVANCES EN EL ESTUDIO CIENTÍFICO DE LA COMPRENSIÓN DE TEXTOS

    OpenAIRE

    2007-01-01

    La comprensión de textos es una actividad psicológica que ha mantenido el interés de investigadores en la ciencia cognitiva. Sin embargo, sólo recientemente han surgido estudios en las neurociencias que intentan develar la maquinaria cerebral que soporta tal proceso. Este escrito revisa algunos de los trabajos clásicos y, particularmente, recientes en la ciencia cognitiva y los avances actuales en la neurociencia de la comprensión de textos. Luego se presenta un potencial modelo neurocognitiv...

  10. Genes antisociales y exención o atenuación de la responsabilidad criminal

    OpenAIRE

    2015-01-01

    En los últimos años son numerosos e intensos los debates que se han mantenido a nivel internacional, tanto desde un punto de vista moral como jurídico, en relación a la idea de que la incapacidad de controlar la agresividad impulsiva puede estar parcialmente influenciada por el perf il genético de un determinado individuo. Así, son numerosas las sentencias en el marco internacional, que han permitido mitigar la pena de los acusados, constituyéndose éstas como hechos alt...

  11. Los desarrolladores de libros app infantiles y juveniles: radiografía, perspectivas y modelo de negocio.

    OpenAIRE

    Sanz Pilar, Neila; García Rodríguez, Araceli

    2014-01-01

    El mercado de Literatura Infantil y Juvenil en España se ha mantenido en auge en las últimas décadas y ha sufrido un incremento exponencial desde la introducción de las TIC’s y el desarrollo de contenidos digitales especialmente dirigidos a niños y jóvenes. Por ese motivo esta investigación pretende mostrar una breve radiografía de los desarrolladores de un determinado tipo de libros electrónicos, los libros aplicación, o enriquecidos, utilizando la terminología anglosajona, destinados a este...

  12. Prevención de úlceras por presión y lesiones musculoesqueléticas: paciente con ictus Pressure ulcer prevention and muscular and skeletal injuries: Patient with stoke

    OpenAIRE

    Carlos Luque Moreno; Marta Peña Salinas; Fátima Rodríguez Pappalardo; Luis López Rodríguez

    2012-01-01

    Planteamos un caso clínico en el que enfermera y fisioterapeuta ponen en común procedimientos para mejorar la higiene postural de un paciente encamado con un accidente cerebrovascular y hemiplejia izquierda. Describimos analíticamente una intervención conjunta durante un mes. A pesar de que se ha mantenido el riesgo máximo de UPP objetivado inicialmente, durante este periodo no han aparecido úlceras, obteniendo un mantenimiento o aumento del rango de las articulaciones. Es importante un traba...

  13. Efectos del Diferencial de Impuestos a las Gasolinas en la Demanda de Automóviles

    OpenAIRE

    2010-01-01

    La política tributaria respecto a los combustibles en Chile ha mantenido desde sus inicios impuestos menores para las gasolinas respecto al diesel. Como resultado la fracción de automóviles con motor diesel en el parque automotor ha crecido fuertemente, en especial durante los últimos cinco años. Dado que en promedio 20% de las emisiones de los motores diesel equivalen a un 80% de las emisiones de motores a gasolinas, esto tiene consecuencias importantes en la magnitud de las externalidades a...

  14. Incidencia de agenesia dental en perros Beagle. Resultados preliminares(Dental agenesis incidence in Beagle dogs. Preliminary results

    Directory of Open Access Journals (Sweden)

    Rodríguez Sosa

    2011-11-01

    Full Text Available ResumenEn el presente trabajo se examinaron 49 perros Beagle procedentes del CENPALAB que fueron mantenidos bajo el mismo régimen de convivencia, alimentación y manejo en el Bioterio de la Facultad de Medicina “Victoria de Girón” tributarios todos a estudios de implantes dentales.AbstractForty-nine Beagle dogs coming from CENPALAB were maintained under the same coexistence, feeding and handling regime in the Bioterio of Medicine High School “Victoria de Girón” tributary to studies of dental implant all them.

  15. Lenguaje y medios: Noticias internacionales de la imprenta a la televisión

    OpenAIRE

    Ávila, Raúl

    2013-01-01

    Cuando Gutenberg inventa la imprenta de tipos móviles en el siglo xv, lo primero que publica es la Biblia, el libro que había sido mantenido casi bajo custodia en los monasterios. Este hecho, sin duda, resulta trascendental en la cultura occidental. Gracias a! nuevo medio de comunicación masiva el conocimiento sagrado pudo evadir el límite de los conventos. Por eso podría considerarse a la imprenta como uno de los factores que hicieron posible el movimiento protestante encabezado por Lutero. ...

  16. El sistema tributario y sus implicaciones en la reducción de pobreza

    OpenAIRE

    2001-01-01

    Los resultados del ajuste estructural son alentadores, en los últimos catorce años se ha mantenido una razonable estabilidad económica e índices de inflación bajos. Sin embargo, los indicadores sociales están muy por debajo del promedio Latinoamericano y son comparables a los de las regiones más empobrecidas del mundo. Para lograr un crecimiento socialmente sostenible se debe diseñar una política fiscal que se atribuya como objetivo central, por el lado de los ingresos y de los egresos, la re...

  17. Mecenazgo cultural: Estado, poder y finaciación de las expresiones artísticas Cultural patronage: State, power, and financing of artistic expressions

    Directory of Open Access Journals (Sweden)

    Mariana Baranchuk

    2007-09-01

    Full Text Available El capital participó en confl uencia con el Estado en la promoción de productos para el mercado cultural desde la antigüedad hasta la actualidad. Este trabajo indaga la relación que a través de distintos momentos históricos han mantenido el poder económico, el Estado y las expresiones artísticas concretas; insinuando que dicho vínculo así como el mantenido con los artistas (y/o trabajadores de la cultura incide sobre la obra concreta tanto en su dimensión simbólica, en tanto producto cultural; como en su dimensión económica, en cuanto mercancía. Palabras clave: Mecenazgo. Financiamiento de expresiones artísticas. Legitimación de artistas. Capital funding has participated, in confluence with the State, in the promotion of products for the cultural market since the ancient times up to nowadays. This work looks into the relationship that the economical power, the State, and the artistic expressions have maintained through different historical moments; insinuating that this linkage, as well as the connection to the artists (and/or cultural workers, affects the work itself, not only in its symbolic dimension, as a cultural product, but in its economic dimension, as a merchandise. Keywords: Patronage. Financing of artistic expressions. Legitimizing artists.

  18. "Recent" macrofossil remains from the Lomonosov Ridge, central Arctic Ocean

    Science.gov (United States)

    Le Duc, Cynthia; de Vernal, Anne; Archambault, Philippe; Brice, Camille; Roberge, Philippe

    2016-04-01

    The examination of surface sediment samples collected from 17 sites along the Lomonosov Ridge at water depths ranging from 737 to 3339 meters during Polarstern Expedition PS87 in 2014 (Stein, 2015), indicates a rich biogenic content almost exclusively dominated by calcareous remains. Amongst biogenic remains, microfossils (planktic and benthic foraminifers, pteropods, ostracods, etc.) dominate but millimetric to centrimetric macrofossils occurred frequently at the surface of the sediment. The macrofossil remains consist of a large variety of taxa, including gastropods, bivalvia, polychaete tubes, scaphopods, echinoderm plates and spines, and fish otoliths. Among the Bivalvia, the most abundant taxa are Portlandia arctica, Hyalopecten frigidus, Cuspidaria glacilis, Policordia densicostata, Bathyarca spp., and Yoldiella spp. Whereas a few specimens are well preserved and apparently pristine, most mollusk shells displayed extensive alteration features. Moreover, most shells were covered by millimeter scale tubes of the serpulid polychaete Spirorbis sp. suggesting transport from low intertidal or subtidal zone. Both the ecological affinity and known geographic distribution of identified bivalvia as named above support the hypothesis of transportation rather than local development. In addition to mollusk shells, more than a hundred fish otoliths were recovered in surface sediments. The otoliths mostly belong to the Gadidae family. Most of them are well preserved and without serpulid tubes attached to their surface, suggesting a local/regional origin, unlike the shell remains. Although recovered at the surface, the macrofaunal assemblages of the Lomonosov Ridge do not necessarily represent the "modern" environments as they may result from reworking and because their occurrence at the surface of the sediment may also be due to winnowing of finer particles. Although the shells were not dated, we suspect that their actual ages may range from modern to several thousands of

  19. Macroepizoísmo em Libinia ferreirae (Crustacea, Brachyura, Majidae Macroepizoites on Libinia ferreirae (Crustacea, Brachyura, Majidae

    Directory of Open Access Journals (Sweden)

    Vanessa C. Winter

    2006-06-01

    Full Text Available Um estudo de distribuição dos macroepizóicos foi realizado numa população do caranguejo-aranha Libinia ferreirae Brito Capello, 1871 proveniente do litoral dos estados do Paraná e de Santa Catarina. O material biológico foi obtido junto aos pescadores, e faz parte do rejeito de pesca. Os caranguejos foram mensurados e os macroepizóicos identificados e contados. Os seguintes macroepizóicos sésseis foram registrados: Calliactis tricolor (Lesueur, 1817 (Cnidaria; Actiniaria (Cnidaria; Arca sp. (Mollusca; Ostreidae (Mollusca; Acanthodesia tenuis (Desor, 1848 (Bryozoa; Cirripedia e duas espécies tubícolas de Gammaridea (Crustacea. Além destes organismos ocorreram dois tubos desabitados e quatro animais vágeis. A anêmona C. tricolor foi a espécie mais abundante e freqüente, sendo, provavelmente, utilizada como mecanismo de camuflagem pelo caranguejo. O macroepizoísmo em L. ferreirae está relacionado com a idade ou tamanho do caranguejo, tendo maior incidência naqueles mais velhos ou de maior porte. Entretanto, a densidade dos macroepizóicos por caranguejo se mantém em torno de três. Não há relação entre o macroepizoísmo e o sexo do hospedeiro; somente fêmeas ovígeras utilizam desse recurso mais freqüentemente do que as não-ovígeras. Devido à maior área de fixação, os macroepizóicos colonizam principalmente a carapaça do caranguejo, enquanto nos pereiópodos há predominância de Bryozoa.A study of the distribution of the macroepizoites was carried out on a population of the spider crab Libinia ferreirae Brito Capello, 1871 from the Southern Brazilian coast. Crabs were obtained from shrimps and fishes by-catch. They were measured, and their macroepizoites were identified and counted. The following sessile macroepizoites were registered: Calliactis tricolor (Lesueur, 1817 (Cnidaria; Actiniaria (Cnidaria; Arca sp. (Mollusca; Ostreidae (Mollusca; Acanthodesia tenuis (Desor, 1848 (Bryozoa; Cirripedia and two species

  20. Spermatogenesis in the rock oyster, Saccostrea forskali (Gmelin, 1791).

    Science.gov (United States)

    Nuurai, Parinyaporn; Panasophonkul, Sasiporn; Tinikul, Yotsawan; Sobhon, Prasert; Wanichanon, Ratanasate

    2016-02-01

    Morphology of the differentiating spermatogenic cells of the rock oyster Saccostrea forskali (Bivalve: Ostreidae) was investigated by light and transmission electron microscopy. The testis is formed by several branching acini containing developing spermatogenic cells, classified into 7 stages based on nuclear characteristics, patterns of chromatin condensation and cytoplasmic contents. The spermatogonium is characterized by a euchromatic nucleus with a prominent nucleolus. The cytoplasm contains several round granulo-fibrillar dense bodies surrounded by numerous mitochondria. The round nucleus of the primary spermatocyte contains patches of electron-dense heterochromatin, numerous proacrosomal vesicles, ribosomes and mitochondria. The secondary spermatocytes contain a reticulated chromatin pattern and reduced number of proacrosomal vesicles. The early spermatids contain a small amount of euchromatin among dense patches of heterochromatin. A large single acrosomal vesicle is located in the posterior part of the cell. The middle spermatid is characterized by the migration of an acrosomal vesicle to the anterior part of the nucleus. The late spermatids contain highly condensed heterochromatin blocks and the acrosomal vesicle becomes cup-shaped and invaginated at the basal part. The spermatozoon contains a barrel-shaped head covered with the cup-like acrosome. At this stage, the subacrosomal space contains an axial rod in subacrosomal materials. Three to four transverse bands appear at the anterior region of the acrosome. The middle piece consists of spherical mitochondria surrounding the proximal and distal centrioles. The flagellum consists of 9+2 axonemal microtubule doublets surrounded by the plasma membrane. Our electron microscopic study of spermatogenesis in the S. forskali provides important new information on the mechanism of development of spermatogenesis of this species.

  1. 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.

  2. The Bivalve Yangtzedonta is not the Brachiopod Xianfengella

    Institute of Scientific and Technical Information of China (English)

    YU Wen

    2005-01-01

    The alleged "holotype" of the bivalve Yangtzedontaprimitiva Yu, 1985 figured by Qian (2001) is a broken and distorted specimen of the brachiopod Xianfengella prima He and Yang, 1982 and not the holotype of Y. primitiva. Qian contends that the oldest recognized monoplacophoran, Maikhanella pristinis (Jiang, 1980), is neither a monoplacophoran nor the oldest molluscan fossil in the Meishucunian Stage of China. Furthermore, he considers that the oldest bivalve Xianfengoconcha elliptica Zhang, 1980 is an inarticulate brachiopod, not a mollusc. Watsonella yunnanensis (He and Yang, 1982), is associated with Yangtzedonta primitiva Yu but indicates no evolutionary relationship between the Classes Rostroconchia and Bivalvia in the Lower Cambrian Zhongyicun Member of the Yuhucun Formation. Qian's confusion in using non-molluscan fossils to discuss the early evolution of shelled molluscs also confuses the basic concepts of the respective groups.

  3. ANCAMAN DI BALIK HASIL LAUT DI PERAIRAN TELUK JAKARTA TERHADAP KESEHATAN MASYARAKAT

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    Satmoko Wisaksono

    2012-10-01

    Full Text Available Tidak dapat dipungkiri dan disangsikan bahwa bahan makanan yang berasal dari hasil perikanan laut mempunyai kadar nilai gizi tinggi. lkan laut misalnya selain dagingnya mudah dicerna, juga kandungan protein, vitamin, mineral serta lemak tak jenuh sangat diperlukan untuk pertumbuhan dan kecerdasan. Jenis-jenis ikan laut segar yang banyak dikonsumsi dan disajikan di restoran seafood adalah ikan tongkol, tengiri, kakap, kerang, cumi, sotong, udang, kepiting, rajungan, dan lain sebagainya.Hasil penelitian yang dilakukan oleh Yayasan Lembaga Konsumen Indoneia (YLKI bekerjasama dengan IPB tahun 1997 menunjukkan bahwa contoh komoditi hasil laut yang diperoleh mengandung logam berat Hg adalah dari kelompok kerang-kerangan (Bivalvia yaitu kerang darah, hijau dan tahu.

  4. 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)

  5. Food and feeding habits of king weakfish, Macrodon ancylodon (Bloch & Schneider, 1801 caught in the southern coast of Brazil (lat, 29º to 32ºs

    Directory of Open Access Journals (Sweden)

    Anastácio Afonso Juras

    1985-01-01

    Full Text Available Macrodon ancylodon was obtained from landings in Santos Port (São Paulo State of fish caught monthly by commercial vessels, on the southern coast of Brazil during September 1976 to August 1977. The measurements of total lenght, total weight determination of sex and maturity stages were made. The food items found in stomach contents were: shrimp (Artemesia longinaris, fishes (Paralonchurus brasiliensis, Macrodon ancylodon, Trichirus lepturus, Gadidae, Engraulidae, molluscs (Loliginidae, Bivalvia and Stomatopoda. Widening of food spectrum was observed in winter. The index of preponderance showed that immature females, immature and mature males fed predominantly on shrimp, while mature females fed mainly on fishes. During spring and summer (spawning season M. ancylodon exhibited relatively low percentage of full stomachs. Cannibalism was encountered more intensively for mature fish.

  6. Molluscs associated with a Sardinian deep water population of Corallium rubrum (Linnι, 1758

    Directory of Open Access Journals (Sweden)

    F. CROCETTA

    2012-12-01

    Full Text Available Molluscan species living in association with Corallium rubrumcolonies are poorly known. Specimensfound on the branches of red coral colonies located off Capo Caccia (Alghero – SS, West Sardinia,Mediterranean Sea were studied by analyzing red coral branches collected at a depth of between 100 and120 m; their assemblage was made up of 44 species, all belonging to the classes Gastropoda and Bivalvia.Some data on the geographical distribution, ecology, taxonomy and dominance of these species, bothalive and dead, are given and the most interesting are commented on. Among the recorded species Triviamultilirata, Simnia purpurea, Coralliophila brevis, Ocinebrina paddeui, Pleurotomella demosia, Palliolumstriatum and Pseudamussium sulcatum deserve attention. Moreover, the second finding of livingspecimens of Asperarca secreta, described only on loose valves, is reported, and finally the prey-predatorrelationships among several gastropods and Cnidarians are confirmed.

  7. Crystallization in organo-mineral micro-domains in the crossed-lamellar layer of Nerita undata (Gastropoda, Neritopsina).

    Science.gov (United States)

    Nouet, Julius; Baronnet, Alain; Howard, Lauren

    2012-02-01

    Crossed-lamellar shell microstructure consists of a sophisticated arrangement of interspersed lamellae, which is very commonly found in Gastropoda or Bivalvia shell layers. Its smallest constitutive microstructural units are usually described as sub-micrometric fibers, or rods, and form very ordered and regular patterns. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) imaging confirms the presence of even smaller building units in the form of organo-mineral granules, and we further investigate their internal structure within aragonite crossed-lamellar internal layer of Nerita undata (Gastropoda, Neritopsina) shell. Their coalescence may have controlled anisotropically the propagation of the crystallographic coherence through this complex microstructure, as suggested by the propagation of the microtwinning pattern between neighboring granules.

  8. Aspectos gerais sobre a alimentação do cangulo, Balistes vetula Linnaeus, 1758 (Pisces - Balistidae no estado de Pernambuco - Brasil

    Directory of Open Access Journals (Sweden)

    Técio Luiz Macêdo Costa

    1987-01-01

    Full Text Available The Balistidae, especially Balistes vetula are commom fishes in tropical waters from Northeastern Brazil. Studies about these fishes captured at the coastal area of Recife between Pina; Boa Viagem, Piedade and Candeias beaches were carried out in order to determine the diet, and to verify a possible diet diversification between the sexes, and times of the year. Males and females had a food diet consisting mostly of molluscs belonging the classes Scaphopoda, Bivalvia, Gastropoda and crustaceans and fishes. Echinoderms, foraminifera, bryozoa, sponges, polychaete worms, coelenterates and brachiopods were also observed in smaller proportions. Both males and females had a carnivorous benthic diet. Growth and changes in the seasons were not reflected by changes in the diet.

  9. ASPECTS OF BIODETERIORATION OF LAPIDEOUS SUBMERGED ARTEFACTS: 3D METHODOLOGIES APPLICATION

    Directory of Open Access Journals (Sweden)

    S. Ricci

    2015-04-01

    Full Text Available Submerged stone archaeological artefacts are bioeroded by endolithic microbiota (cyanobacteria, algae and fungi and macroborers (Porifera, Bivalvia and Sipuncula. Optical microscope and SEM observations permit to analyse the bioerosion traces and to identify bioeroders. Data obtained with these techniques cannot be used to estimate volumes of material bioeroded. This aspect require the need to collect three-dimensional, close-range data from artefact. In this work we illustrate two 3D imaging techniques used to study bioerosion phenomena of underwater Cultural Heritage. In particular Digital Video Microscope permit the elaboration of 3D images, which are widely employed for close-range acquisitions. Underwater Laser Scanner documents the in situ degradation of submerged artefacts. This research aims to sensitize specialist figures in the study 3D offering a starting point for future collaborations that could lead to interesting results.

  10. OIL DECONTAMINATION OF BOTTOM SEDIMENTS EXPERIMENTAL WORK RESULTS

    Directory of Open Access Journals (Sweden)

    Lushnikov Sergey V.

    2006-08-01

    Full Text Available This article presents the results of experimental work during 2004-2005 on oil decontamination of bottom sediments of Lake Schuchye, situated in the Komi Republic (Northern Russia. The cause of thecontamination were huge oil spills occurred after a series of accidental ruptures on the Harjaga-Usinsk and Vozej-Usinsk oil-pipe lines in 1994. Flotation technology was used for the cleaning of bottom sediments.157 tons of crude oil were removed during the course of 2-year experimental work from an area of 4,1 ha.The content of aliphatic and alicyclic oil hydrocarbons was reduced from 53,3 g/kg to 2,2 g/kg, on average.Hydrobiological investigations revealed that bottom sediments started to be inhabited by benthos organisms, dominantly Oligochaeta. Besides Oligochaeta, Chironomidae maggots and Bivalvia were detected. Theappearance of Macrozoobenthos organisms can serve as a bioindicator of water quality.

  11. Aspects of Biodeterioration of Lapideous Submerged Artefacts: 3d Methodologies Application

    Science.gov (United States)

    Ricci, S.; Antonelli, F.; Sacco Perasso, C.

    2015-04-01

    Submerged stone archaeological artefacts are bioeroded by endolithic microbiota (cyanobacteria, algae and fungi) and macroborers (Porifera, Bivalvia and Sipuncula). Optical microscope and SEM observations permit to analyse the bioerosion traces and to identify bioeroders. Data obtained with these techniques cannot be used to estimate volumes of material bioeroded. This aspect require the need to collect three-dimensional, close-range data from artefact. In this work we illustrate two 3D imaging techniques used to study bioerosion phenomena of underwater Cultural Heritage. In particular Digital Video Microscope permit the elaboration of 3D images, which are widely employed for close-range acquisitions. Underwater Laser Scanner documents the in situ degradation of submerged artefacts. This research aims to sensitize specialist figures in the study 3D offering a starting point for future collaborations that could lead to interesting results.

  12. Benthic macroinvertebrates as bioindicators of water quality in an Atlantic forest fragment

    Directory of Open Access Journals (Sweden)

    Augusto Oliveira

    2010-12-01

    Full Text Available The objective of this study was to evaluate benthic macroinvertebrate communities as bioindicators of water quality in five streams located in the "Reserva Particular do Patrimônio Natural" (RPPN Mata Samuel de Paula and its surroundings, in the municipality of Nova Lima near the city of Belo Horizonte, Minas Gerais State, southeastern Brazil. This region has been strongly modified by human activities including mining and urbanization. Samples were collected in the field every three months between August 2004 and November 2005, totaling six samplings in the rainy and dry seasons. This assessment identified one area ecologically altered while the other sampling sites were found to be minimally disturbed systems, with well-preserved ecological conditions. However, according to the Biological Monitoring Work Party (BMWP and the Average Score Per Taxon (ASPT indices, all sampling sites had excellent water quality. A total of 14,952 organisms was collected, belonging to 155 taxa (148 Insecta, two Annelida, one Bivalvia, one Decapoda, one Planariidae, one Hydracarina, and one Entognatha. The most abundant benthic groups were Chironomidae (47.9%, Simuliidae (12.3%, Bivalvia (7.5%, Decapoda (6.1%, Oligochaeta (5.2%, Polycentropodidae (3.7%, Hydropsychidae (2.5%, Calamoceratidae (1.8%, Ceratopogonidae (1.7%, and Libellulidae (1.2%. The assessment of the benthic functional feeding groups showed that 34% of the macroinvertebrates were collector-gatherers, 29% predators, 24% collector-filterers, 8% shredders, and 5% scrapers. The RPPN Mata Samuel de Paula comprises diversified freshwater habitats that are of great importance for the conservation of many benthic taxa that are intolerant to organic pollution.

  13. Manejo de primates en cautiverio: interpretación de marcadores etológicos de adaptación en Cebus libidinosus juveniles Management of Captive Primates: Ethological Bookmarks in Cebus libidinosus

    Directory of Open Access Journals (Sweden)

    A.M Giudice

    2011-06-01

    Full Text Available Los primates mantenidos en cautiverio, evidencian la necesidad de estimular su comportamiento natural y de promover su bienestar. Esta contribución describe los cambios en los marcadores etológicos en Cebus libidinosus (CLI juveniles (1 macho y 2 hembras mantenidos en cautiverio (ECAS, Berazategui, Argentina, bajo dos condiciones de alojamiento. Se utilizó el muestreo de barrido. Se evaluó la conducta "locomoción estereotipada". El tiempo total de observación fue de 290 horas. El nivel de locomoción estereotipada descendió y la jeraquía social se modifico. CLI mantenidos en cautiverio muestran: incremento en el comportamiento de interacción ambiente físico-social luego del cambio de recinto y la frecuencia de locomoción estereotipada se relacionó con las tareas de mantenimiento. Debido a la condición social de las especies de primates, el mantener grupos sociales formados según su estructura social en vida libre, resulta en un aumento de bienestar mayor que cambios en las condiciones físicas del alojamiento.The primates maintained in captivity, highlight the need to encourage their natural behavior and promote their welfare. In this paper we describe the changes in the ethological markers in Cebus libidinosus (CLI juvenile (1 male and 2 females kept in captivity (ECAS, Berazategui, Argentine, under two housing conditions. We used scan sampling. We evaluated the behavior "stereotyped locomotion". The total observing time was 290 hours. Stereotyped locomotion level decrease and the social hierarchy was modified. CLI maintained in captivity shows: an increase in the behavior of the physical environment and social interaction after the change of enclosure and frequency of stereotyped locomotion was associated with maintenance. Because the social status of the species of primates, maintaining in groups formed according to their social structure in the wild, resulting in a greater welfare benefit that changes in the physical conditions

  14. Chile: Neoliberalismo y subdesarrollo económico

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    Raúl Concha Monardes

    2014-12-01

    Full Text Available Se expone que el Régimen Militar que gobernó a Chile entre 1973 y 1990 ejecutó reformas  económicas y sociales con el objetivo declarado de crear una nueva economía. Presentado como  el modelo que terminaría con los atrasos del país hasta convertirlo en uno plenamente desarrollado, los gobiernos democráticos que le sucedieron, han mantenido vigente la fórmula hasta el día de hoy. Este artículo esboza algunas de las causas que podrían explicar el bloqueo chileno hacia el desarrollo económico.

  15. DELEUZE, Gilles (2014, Michel Foucault y el poder, Viajes iniciáticos I, trad. Javier Palacio Tauste, Errata naturae, Madrid, 168 pp.

    Directory of Open Access Journals (Sweden)

    Alba Ramírez Guijarro

    2014-06-01

    Full Text Available Durante el curso 1985-1986 en la Universidad de París 8, Vincennes-Saint Denis, Deleuze imparte clases sobre Foucault, con quien había mantenido amistad. Tras la muerte de Foucault, Deleuze considera que no hay mayor homenaje que leer y releerle, y a lo largo de las tres lecciones que se hallan en el presente volumen explica sus lecturas, es decir, expone la manera en que ha de leerse a Foucault y cómo ha de entenderse la transición del saber al poder, tema central que aborda desde la obra de Foucault, sobre todo a partir de La arqueología del saber y Vigilar y castigar.

  16. Crecimiento económico y demográfico regional en Colombia, 1985-2012

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    Luis Armando Galvis

    2015-12-01

    Full Text Available En el crecimiento económico y demográfico de Colombia han primado las grandes urbes, y en términos demográficos hoy es un país urbano. Este artículo examina la dinámica del crecimiento económico, en especial, la dinámica poblacional desde mediados de los ochenta. El análisis de las matrices de transición de Markov indica que el comportamiento demográfico de los municipios muestra signos de persistencia. Las principales ciudades mantienen su jerarquía y siguen siendo las más densamente pobladas. Los municipios con bajo nivel de densidad se han mantenido relativamente estancados en términos demográficos.

  17. Entre la racionalidad tecnocrática y la gobernabilidad. La importancia del consenso político en México

    OpenAIRE

    Rogelio Hernández Rodríguez

    2014-01-01

    Desde los años ochenta del siglo pasado la élite tecnocrática ha operado la economía mexicana sin importar si gobierna el país el P artido R evolucionario I nstitucional o algún partido de oposición . Además de no manifestar ningún compromi s o ideológico o partidario, la élite ha mantenido un estricto control de las finanzas públicas nacionales generando importantes consecuencias políticas y electorales en el país . Al margen de si existen o no otras opciones econó micas, el principal proble...

  18. Eficiencia técnica y ambiental de la camaronicultura en Nayarit aplicando el índice de Malmquist

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    Francisco Javier Martínez-Cordero

    2015-01-01

    Full Text Available A partir de una base de datos no homogénea de 32 granjas de camarón en Nayarit para el periodo 2008-2011, el presente estudio aplica el índice de Malmquist para analizar su eficiencia técnica ET y ambientalmente ajustada EAA de una empresa o industria acuícola sostenible. Los resultados indican que los niveles de ET y EAA se han mantenido arriba de 0.80 y 0.75 en promedio, respectivamente. En general, los resultados confirman estudios regionales previos del cultivo de camarón, en función de que los rendimientos (kg/ha/año pueden ser decrecientes por causa de las enfermedades virales. Se recomienda aplicar estos indicadores de manera continua para asistir la planificación y toma de decisión tanto a nivel empresa como industria.

  19. La asociación pro indígena y las atrocidades del Putumayo, una misión auto restringida.

    Directory of Open Access Journals (Sweden)

    Frederica Barclay Rey de Castro

    2010-01-01

    Full Text Available Este artículo examina el accionar y la postura de la Asociación Pro Indígena frente a la población indígena amazónica a inicios del siglo XX a través de un análisis de su intervención en el caso del Putumayo. Argumenta que, sin haberse mantenido al margen del caso, la Asociación Pro Indígena optó por auto restringir su papel en este importante caso sin poder escapar a las presiones “nacionalistas” que pesaban en el ambiente, justificando su rol en la marginalidad social de los indígenas amazónicos no obstante que reconoció la gravedad de los hechos y caracterizó el fenómeno como de abierta esclavitud.

  20. Las construcciones condicionales en el marco de la oración compuesta

    OpenAIRE

    Hernán Cuadrado, Luis Alberto

    2013-01-01

    Según la Real Academia Española, "el periodo condicional, llamado también hipotético, consta [...] de dos oraciones, relacionadas mediante la conjunción si. Una de ellas, la que expresa la condición, es la subordinada, y se llama prótasis; y la otra, que expresa la consecuencia, es la principal, y se llama apódosis" (Gramática, § 433, b). Esta caracterización del periodo u oración condicional ofrecida por la Real Academia Española en su Gramática se ha mantenido sin cambios sustanciales en e...

  1. Gobiernos democráticos del Estado español frente la persistencia de la memoria y la historia de las fosas de la guerra civil española. La actuación de la Generalitat en Cataluña (2004-2015

    Directory of Open Access Journals (Sweden)

    Queralt Solé

    2016-01-01

    Full Text Available Desde el año 2002 en Cataluña ha existido la demanda social para la localización de personas desaparecidas durante la Guerra Civil, algunas de ellas aún hoy en día enterradas en fosas comunes que se han mantenido hasta la actualidad. La Generalidad de Cataluña, a diferencia de otros gobiernos autonómicos, ha llevado a cabo diversas exhumaciones y recogida de restos en superficie con diferentes resultados. El presente artículo, realizando un recorrido que va de historia a la arqueología, expone como se desarrollaron estas actuaciones y analiza cuales fueron los resultados de cada una de ellas.

  2. Las bases del nuevo debate intersubjetivo: comunidad científica ampliada y evaluación social de la ciencia

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    Marcos Antonio da Silva

    2015-08-01

    Full Text Available Este trabajo enfoca uno de los aspectos más problemáticos para el análisis de las ciencias actuales: la discusión acerca de la evaluación de las ciencias y sus consecuencias para la actividad científica. En este escenario, asume como objeto de su análisis el intento de colocar en nuevas bases el debate sobre un mundo posible: la evaluación social de la ciencia. En este ámbito, cabe notar, la comunidad científica – comunidad científica estándar – siempre se ha mantenido como el punto básico de la evaluación de la ciencia y de toda la actividad científica.

  3. A formulação da política de segurança alimentar no Peru 2001-2006: um estudo de caso no departamento de Puno.

    OpenAIRE

    Montaño, Edgard Manuel Hito

    2009-01-01

    p. 1-191 En el Perú una cuarta parte de niños menores de 5 años se encuentran en desnutrición crónica y la evolución de este indicador desde 1996 prácticamente se ha mantenido igual. En el departamento de Puno el problema aún es mayor por sus condicionantes socio-económicas y políticas. Después del ajuste estructural provocado por los cambios del sistema económico, la mitad de la población peruana, pasó al estado de pobreza y una cuarta parte a la extrema pobreza; siendo afectado el acceso...

  4. Modelos contables y comprensión de la crisis financiera

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    Dirk J. Bezemer

    2012-06-01

    Full Text Available Este artículo muestra que los modelos macroeconómicos contables ayudaron a prever la crisis de crédito y la recesión económica, mientras que los modelos de equilibrio ubicuos en la formulación de política y la investigación de la corriente principal no. Explora los antecedentes intelectuales del enfoque contable como alternativa a la economía neoclásica y el ascenso y declive de los modelos de flujo de fondos durante la posguerra. Incluye estudios de caso actuales de ambos tipos de modelos y analiza por qué el enfoque contable se ha mantenido fuera de la corriente dominante. Hace recomendaciones constructivas para revisar los métodos de evaluación de la estabilidad financiera y aboga por una “contabilidad de la economía”.

  5. Servicios, patología y rehabilitación de muralla e instalaciones de recreo

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    Cuenca García, Juan Antonio

    1985-04-01

    Full Text Available Not Available.El pueblo de Granadilla ha mantenido durante siglos su configuración de pueblo defensivo, sin extenderse fuera de sus murallas; esto dio lugar a la creación, por un lado, de un sistema de trazado urbanístico propio, basado en las directrices de toda ciudad árabe con recinto defensivo y, por otro lado, de una infraestructura en materia de servicios orientada hacia el autoabastecimiento, sobre todo, en tiempos de guerra y sitio. Hasta hace relativamente poco tiempo, en el pueblo no existía luz eléctrica ni abastecimiento de agua potable. Exclusivamente disponían de unos aljibes donde captaban el agua de lluvia. Tampoco existía red de saneamiento, sirviéndose de los ya tradicionales pozos negros.

  6. Pierre Vilar Frontinhan 1906 - París 2003

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    Pablo Rodríguez

    2010-08-01

    Full Text Available En el pasado mes de agosto falleció en París el historiador y maestro de tantas generaciones Pierre Vilar. Aunque había mantenido una intensa actividad de reflexión sobre los sucesos contemporáneos, ésta se vio afectada en 1991 luego que una grave enfermedad le negó la visión. Fue entonces cuando decidió con la ayuda de Rosa Congost escribir sus reflexiones y recuerdos, especie de memoria de juventud. Pensar Históricamente (Barcelona: Editorial Crítica, 1997, el libro que reúne estos ejercicios, es una obra de sumo interés para conocer la infancia, adolescencia y juventud de este connotado historiador.

  7. Actividad del virus del oeste del Nilo y otros flavivirus en cinco departamentos del Caribe colombiano

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    Jaime Álvarez

    2010-04-01

    Full Text Available El virus del oeste del Nilo (VON y el virus de la encefalitis de San Luis (VESL pertenece a la familia Flaviviridae, género Flavivirus y hacen parte del serocomplejo de la encefalitis japonesa (1. Estos virus se encuentran distribuidos en Estados Unidos, centro América y suramerica (2. Son mantenidos en la naturaleza en un ciclo enzoótico ave-mosquito-ave. Humanos, équidos y otros vertebrados se infectan por la picadura de mosquitos del genero Culex principalmente (1,2. En humanos se han identificado y descrito nuevos modos de transmisión de VON incluyendo infección a través de productos sanguíneos contaminados (3, transplante de órganos (4, transmisión a través de la leche materna (5, transmisión intrauterina (6, y exposición ocupacional (7.

  8. Elementos históricos sobre la prostitución femenina en Costa Rica. El caso del Valle Central Noroccidental.

    OpenAIRE

    Fernández Carballo, Rodolfo; Rodríguez Sancho, Javier

    2011-01-01

    En este artículo, el lector encontrará un análisis socio-histórico acerca de algunos aspectos que evidenciaron la prostitución femenina en la Sección Noroccidental del Valle Central de Costa Rica durante el siglo XX.Por ello, hemos efectuado una valoración de fondo acerca de los diversos factores socialesque dieron origen al fenómeno en la región, sin dejar de lado, otras localidades del país que de una u otra forma han mantenido vínculos con el área de estudio.Con base en diversas fuentes e ...

  9. Una introducción a los presupuestos sensibles al généro

    OpenAIRE

    2016-01-01

    Los presupuestos públicos: un reflejo de las prioridades gubernamentales A raíz de las crisis económicas en las que se han visto inmersos diversos países en la última década, los arquitectos de las políticas públicas han comenzado a reconocer, al menos a nivel discursivo, la necesidad de integrar “políticas sociales” en la administración macroeconómica. A pesar de esta intención, se ha mantenido el diseño de políticas macro económicas con un enfoque de indicadores y criterios de eficiencia, p...

  10. Un análisis de la integración comercial entre los países de América del Sur

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    Vázquez Cueto, María José

    2008-01-01

    Full Text Available Los países que componen América del Sur vienen históricamente intentando unaintegración económica (CAN, MERCOSUR y Chile con mayor o menor fortuna. En estetrabajo se trata de analizar la evolución de la integración global entre ellos a través deindicadores que relacionan sus flujos comerciales, midiendo sus distintos grados de apertura yde conexión. Tomando como años de referencia 1996 y 2006, observamos los distintoscomportamientos de los países del lado de sus exportaciones. La evidencia empírica nosmuestra como el cambio en las relaciones que ha mantenido Venezuela con el resto, a nivel deexportaciones, han supuesto un freno hacia el proceso de integración comercial entre ellos

  11. Una aproximación a las funciones ejecutivas en el trastorno del espectro autista

    OpenAIRE

    2011-01-01

    Introducción: La hipótesis psicológica de la disfunción ejecutiva desempeña un papel crucial para explicar el fenotipo conductual de las personas con trastornos del espectro autista (TEA), relacionada también con otras hipótesis como el déficit en teoría de la mente o la hipótesis de la coherencia central débil. Sin embargo, ninguna de estas hipótesis son mutuamente excluyentes y los comportamientos que tienen su origen en alguna de esas tres hipótesis están también moldeados y mantenidos por...

  12. Entre guerra y paz. América Latina frente a la tragedia del primer conflicto mundial

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    GRAZIANO PALAMARA

    2015-07-01

    Full Text Available El presente ensayo propone un análisis de las posturas latinoamericanas ante la Primera Guerra Mundial -Pgm-; la reflexión se fundamenta en un modelo interpretativo, que considera las guerras de alcance mundial, no solo como el punto de disgregación de un sistema internacional, sino como el momento fundante de un nuevo orden. Este modelo permite reflexionar en cuanto a la manera como Latinoamérica se acercó al declive del orden posnapoleónico y la conducta que adoptó, en 1917, al ingresar Estados Unidos al conflicto y la Revolución de Octubre en Rusia, cuando se abrió en el contexto de las relaciones internacionales una nueva época que habría mantenido intactas algunas de sus características, por lo menos hasta la caída del muro de Berlín.

  13. Balance energético de juveniles de Chirostoma estor estor (Jordan, 1879) (Pisces,Atherinopsidae) en relación con el tamaño corporal

    OpenAIRE

    María Eugenia Vega; Fernando Díaz; Sonia Espina

    2004-01-01

    En este trabajo se determinó el flujo energético de juveniles de Chirostoma estor estor (Jordan, 1979) de dos diferentes clases de peso (P 0.05). En la Clase A se agruparon los peces de 1.50 ± 0.22 g y en la Clase B los de 3.30 ± 0.29 g. Los peces mantenidos a 20 °C, se alimentaron al 4% del peso corporal, con una dieta balanceada comercial (28% de proteína). Se midieron las respuestas fisiológicas y se integraron en la ecuación del balance energético con el fin de estimar la energía potenci...

  14. El Diario de Agustín

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    Manuel Gárate

    2009-01-01

    Full Text Available Un importante éxito de público y la difusión  por el llamado “boca a boca”, han sido los elementos más singulares del estreno del documental “El Diario de Agustín” de los realizadores chilenos Ignacio Agüero y Fernando Villagrán. Esto no es menor cuando se trata de un proyecto que critica duramente al principal conglomerado de la prensa chilena y que por años ha mantenido un enorme poder e influencia en la política local. El documental expone  el papel jugado por el diario El Mercurio -de pr...

  15. El Diario de Agustín

    OpenAIRE

    2009-01-01

    Un importante éxito de público y la difusión  por el llamado “boca a boca”, han sido los elementos más singulares del estreno del documental “El Diario de Agustín” de los realizadores chilenos Ignacio Agüero y Fernando Villagrán. Esto no es menor cuando se trata de un proyecto que critica duramente al principal conglomerado de la prensa chilena y que por años ha mantenido un enorme poder e influencia en la política local. El documental expone  el papel jugado por el diario El Mercurio -de pro...

  16. De la hegemonía a la multipolaridad en el comercio internacional desde la posguerra

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    Hernández Adolfo

    1987-06-01

    Full Text Available EI presente artículo se propone interpretar los cambios que en el curso de la posguerra han sufrido las participaciones de unos cuantos países y grupos de países en el comercio mundial desde la posguerra. Algunas de estas se han mantenido relativamente estables; otras han experimentado variaciones abruptas, lo que plantea interrogantes acerca de tres cuestiones cruciales de la economía mundial: las relaciones entre las naciones capitalistas avanzadas y las subdesarrolladas; la participación de los países de economía planificada en el comercio de Occidente, y la competencia entre países capitalistas avanzados.

  17. Flexibilidad y estrategias laborales de los profesionistas en la Zona Metropolitana de Monterrey

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    Mario Alberto Jurado Montelongo

    2001-01-01

    Full Text Available La restructuración económica en marcha desde la década de 1980 en la Zona Metropolitana de Monterrey (ZMM, ha impactado en la dinámica del mercado laboral. La movilidad laboral se ha alterado. Los trabajadores de alta escolaridad han mantenido su presencia creciente en el mercado laboral y han experimentado un aumento constante en sus jornadas laborales y una disminución de la cobertura de las prestaciones sociales vinculadas a los servicios médicos, principalmente. Por medio de una revisión de las estadísticas presentadas por la Encuesta Nacional de Empleo Urbano (eneu este artículo busca resaltar algunas consecuencias en las condiciones de trabajo de los técnicos y profesionistas tomando en cuenta la caída en importancia de los empleos estables o por contrato indeterminado

  18. Brasil, América Latina e crise das reformas liberais

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    Luis Sergio Henriques

    2002-01-01

    Full Text Available En esta entrevista, concedida a la revista ESPACIOS (CINDES, Ecuador, y que se nos ha dado la primicia de su publicación, el autor opina críticamente sobre el futuro de Brasil, y de Latinoamérica en general, frente a las reformas liberales que la sociedad capitalista está implementando a nivel global. Brasil ha respondido a estas “reformas liberales”, entre dos escenarios que se han mantenido coexistiendo: por un lado, las fuerzas totalitarias y conservadoras que se adhieren al sistiema; por el otro, las fuerzas sociales disidentes de izquierda que se valen de la sociedad civil para demandar una democracia más participativa con el propóstio de combatir la hegemonía política y socio-cultural.

  19. Los Goya: de la Quinta a Burdeos y vuelta

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    Junquera, Juan José

    2003-12-01

    Full Text Available This paper is a scholarly complement to the assertions made by the author in a recent book and article concerning the authorship of the paintings in the Quinta del Sordo. He proposes that these creations are not by Francisco de Goya, and advances the possibility that Javier Goya could have falsified his father's works. Key words: Spanish painting; 18th century; Francisco de Goya; Black paintings.

    El artículo completa, con aparato crítico, lo mantenido por el autor en un reciente libro y artículo: la imposibilidad de atribución de las Pinturas Negras a Francisco de Goya, haciéndose también una primera tentativa de deslinde de las falsificaciones de la obra paterna por parte de Javier Goya.

  20. Compromiso ontológico de la música occidental

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    Myriam Arroyave Montoya

    2013-01-01

    Full Text Available La música occidental ha mantenido una relación cruzada y necesaria, más o menos comprometida, con la aritmética, la geometría y la física. En este artículo se hace un seguimiento histórico de este vínculo, intentando poner en evidencia algunas de las problemáticas filosóficas y epistemológicas compartidas por aquellas disciplinas. El camino seguido empieza en los griegos y termina en la Alta Edad Media, época en la que se establecen los principios de la notación diastemática, que constituye el fundamento de la escritura sobre pentagrama, es decir, el sistema simbólico característico de la tradición occidental hasta el siglo XX.