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Sample records for prosobranch mollusc hydrobia

  1. Review of intersex in gastropods and other molluscs

    DEFF Research Database (Denmark)

    Strand, Jakob

    Various studies have demonstrated that the presence of imposex, i.e. an imposition of a penis and/or a vas deferens in addition to the normal reproductive tracts in females of gonochoristics prosobranch gastropod species, is a common phenomenon in the marine environment today. However, also other....... This includes examples like transformation of the reproductive and genital tracts in gastropods and cephalopods, spermatogenesis in the female ovary and oocyte development in male testis (ovo-testis).  ......Various studies have demonstrated that the presence of imposex, i.e. an imposition of a penis and/or a vas deferens in addition to the normal reproductive tracts in females of gonochoristics prosobranch gastropod species, is a common phenomenon in the marine environment today. However, also other...... signs of endocrine disruption causing sex reversal, characterized as intersex, have been reported for marine molluscs. Intersex can more generally be defined as disturbance of the phenotypic sex characters and different types of intersex have been recorded for both female and male molluscs...

  2. Reproduction-associated immunoreactive peptides in the nervous systems of prosobranch gastropods.

    Science.gov (United States)

    Ram, J L; Gallardo, C S; Ram, M L; Croll, R P

    1998-12-01

    Antibodies against reproductive peptides of Aplysia and Lymnaea were used to localize homologous immunoreactive peptides in the nervous systems of three prosobranch species: Busycon canaliculatum, Concholepas concholepas, and Tegula atra. Positive control experiments in L. stagnalis demonstrated the broad species range of the anti-egg-laying hormone (anti-ELH) antibody used in this study, and showed binding of anti-alpha-caudodorsal-cell peptide (anti-alpha-CDCP) to the same cells in cerebral and buccal ganglia. Dot immunoassays with synthetic ELH confirmed the reactivity and sensitivity (concholepas and T atra, ELH-like immunoreactivity was found in cerebral ganglia, and in T. atra in fibers in the cerebral ganglia and cerebral-pedal connectives. Thus, cerebral ganglia are the major locus of the ELH-like immunoreactivity in prosobranchs.

  3. Implications of Zostera noltii recolonization on Hydrobia ulvae population structure success.

    Science.gov (United States)

    Grilo, T F; Cardoso, P G; Pardal, M A

    2012-02-01

    Over 1990-1998, the Mondego estuary, Portugal, experienced profound modifications due to eutrophication, culminating in the disappearance and replacement of Zostera noltii by opportunistic macroalgae in the inner most disturbed areas. A decade after restoration measures implementation, Z. noltii started to gradually recolonize the inner parts, following 20 years of absence. This work explores the factors underlying successful Z. noltii recolonization and its subsequent implications on a mud snail Hydrobia ulvae population. During the macroalgal bloom, highest values in H. ulvae abundance, biomass and production were recorded, strongly declining afterwards. Three recovery attempts characterized the post-restoration phase, with considerably increases in H. ulvae abundance, biomass and production since Z. noltii reappearance. The seagrass provided long-term protection and abundant food resources for reproductive adults, contrarily to the ephemeral macroalgae. Through time, large size individuals increased, becoming the population more stable, structured and similar to the one inhabiting the "original"Z. noltii meadows. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Viruses infecting marine molluscs.

    Science.gov (United States)

    Arzul, Isabelle; Corbeil, Serge; Morga, Benjamin; Renault, Tristan

    2017-07-01

    Although a wide range of viruses have been reported in marine molluscs, most of these reports rely on ultrastructural examination and few of these viruses have been fully characterized. The lack of marine mollusc cell lines restricts virus isolation capacities and subsequent characterization works. Our current knowledge is mostly restricted to viruses affecting farmed species such as oysters Crassostrea gigas, abalone Haliotis diversicolor supertexta or the scallop Chlamys farreri. Molecular approaches which are needed to identify virus affiliation have been carried out for a small number of viruses, most of them belonging to the Herpesviridae and birnaviridae families. These last years, the use of New Generation Sequencing approach has allowed increasing the number of sequenced viral genomes and has improved our capacity to investigate the diversity of viruses infecting marine molluscs. This new information has in turn allowed designing more efficient diagnostic tools. Moreover, the development of experimental infection protocols has answered some questions regarding the pathogenesis of these viruses and their interactions with their hosts. Control and management of viral diseases in molluscs mostly involve active surveillance, implementation of effective bio security measures and development of breeding programs. However factors triggering pathogen development and the life cycle and status of the viruses outside their mollusc hosts still need further investigations. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Effects of endocrine disruptors on prosobranch snails (Mollusca: Gastropoda) in the laboratory. Part II: Triphenyltin as a xeno-androgen.

    Science.gov (United States)

    Schulte-Oehlmann, U; Tillmann, M; Markert, B; Oehlmann, J; Watermann, B; Scherf, S

    2000-12-01

    In laboratory experiments the effects of suspected endocrine disrupting chemicals on freshwater and marine prosobranch species were analysed. In this second of three publications the responses of the freshwater ramshorn snail Marisa cornuarietis and of two marine prosobranchs (the dogwhelk Nucella lapillus and the netted whelk Hinia reticulata) to the xeno-androgenic model compound triphenyltin (TPT) are presented. Marisa and Nucella were exposed via water (nominal concentrations 5-500 ng TPT-Sn/L) and Hinia via sediments (nominal concentrations 50-500 micrograms TPT-Sn/kg dry wt.) for up to 4 months. Female ramshorn snails but not the two marine species developed imposex in a time and concentration dependent manner (EC10 4 months: 12.3 ng TPT-Sn/L) with a comparable intensity as described for tributyltin. TPT reduced furthermore the fecundity of Marisa at lower concentrations (EC10 4 months: 5.59 ng TPT-Sn/L) with a complete inhibition of spawning at nominal concentrations > or = 250 ng TPT-Sn/L (mean measured +/- SD: > or = 163 +/- 97.0 ng TPT-Sn/L). The extension of the pallial sex organs (penis with accessory structures and prostate gland) of male ramshorn snails and dogwhelks were reduced by up to 25% compared to the control but not in netted whelks. Histopathological analyses for M. cornuarietis and H. reticulata provide evidence for a marked impairment of spermatogenesis (both species) and oogenesis (only netted whelks). The test compound induced a highly significant and concentration independent increase in the incidence of hyperplasia on gills, osphradia and other organs in the mantle cavity of N. lapillus indicating a carcinogenic potential of TPT. The results show that prosobranchs are sensitive to endocrine disruption at environmentally relevant concentrations of TPT. Also, M. cornuarietis is a promising candidate for a future organismic invertebrate system to identify endocrine-mimetic test compounds.

  6. Effects of endocrine disruptors on prosobranch snails (Mollusca: Gastropoda) in the laboratory. Part I: Bisphenol A and octylphenol as xeno-estrogens.

    Science.gov (United States)

    Oehlmann, J; Schulte-Oehlmann, U; Tillmann, M; Markert, B

    2000-12-01

    The effects of suspected endocrine disrupting chemicals on freshwater and marine prosobranch species were analysed in laboratory experiments. In this first publication, the responses of the freshwater snail Marisa cornuarietis and of the marine prosobranch Nucella lapillus to the xeno-estrogenic model compounds bisphenol A (BPA) and octylphenol (OP) are presented at nominal concentration ranges between 1 and 100 micrograms/L. Marisa was exposed during 5 months using adult specimens and in a complete life-cycle test for 12 months. In both experiments, the xeno-estrogens induced a complex syndrome of alterations in female Marisa referred to as "superfemales" at the lowest concentrations. Affected specimens were characterised by the formation of additional female organs, an enlargement of the accessory pallial sex glands, gross malformations of the pallial oviduct section resulting in an increased female mortality, and a massive stimulation of oocyte and spawning mass production. The effects of BPA and OP were comparable at the same nominal concentrations. An exposure to OP resulted in inverted U-type concentration response relationships for egg and spawning mass production. Adult Nucella from the field were tested for three months in the laboratory. As in Marisa, superfemales with enlarged accessory pallial sex glands and an enhancement of oocyte production were observed. No oviduct malformations were found probably due to species differences in the gross anatomical structure of the pallial oviduct. A lower percentage of exposed specimens had ripe sperm stored in their vesicula seminalis and additionally male Nucella exhibited a reduced length of penis and prostate gland when compared to the control. Because statistically significant effects were observed at the lowest nominal test concentrations (1 microgram BPA or OP/L), it can be assumed that even lower concentrations may have a negative impact on the snails. The results show that prosobranchs are sensitive to

  7. Effects of endocrine disruptors on prosobranch snails (Mollusca: Gastropoda) in the laboratory. Part III: Cyproterone acetate and vinclozolin as antiandrogens.

    Science.gov (United States)

    Tillmann, M; Schulte-Oehlmann, U; Duft, M; Markert, B; Oehlmann, J

    2001-12-01

    The effects of suspected endocrine disrupting chemicals on freshwater and marine prosobranch species were analysed in laboratory experiments. In this last of three publications, the responses of the fresh water snail Marisa cornuarietis and of two marine prosobranchs (Nucella lapillus, Nassarius (Hinia) reticulatus) to the antiandrogenic model compounds cyproterone acetate (CPA) and vinclozolin (VZ) are presented. The snails were exposed to nominal CPA concentrations of 1.25 mg/L alone and simultaneously to a potent synthetic estrogen (ethinylestradiol), androgen (methyltestosterone) or an indirectly acting xeno-androgen (tributyltin) in experiments with adult specimens and in a life cycle test for 12 months. Marisa and Nucella were furthermore exposed to nominal concentrations of 0.03-1.0 microgram VZ/L for up to 5 months. The antiandrogens induced a number of biological responses in all three species. The length of the penis and of accessory male sex organs (e.g., penis sheath, prostate) were significantly reduced. For Marisa, this effect occurred only in sexually immature specimens and was reversible as the males attained puberty. Typical androgen-mediated responses (imposex development, delayed spermatogenesis, tubulus necrosis of the testis with orchitis and Leydig cell hyperplasia) were partially or totally suppressed by a simultaneous administration of CPA. In the two marine species even adult, sexually mature males responded to antiandrogens with a reduction of the male sex organs and an advancement of the sexual repose phase. The results for CPA and VZ are compared with the effects of an exposure to xeno-estrogens (bisphenol A, octylphenol) and xeno-androgens (triphenyltin, tributyltin) in the same species. Each group of endocrine disruptors induces a characteristic set of toxicological effects in prosobranch snails which can be used as endpoints in an organismic invertebrate test for the identification of endocrine mimetic test compounds. Estrogens cause

  8. Evaluation of yolk protein as biomarkers for endocrine disruption in molluscs

    DEFF Research Database (Denmark)

    Morthorst, Jane Ebsen; Holbech, Henrik; Kinnberg, Karin Lund

    is also regulated by estrogens in molluscs even though it still remains unknown if and where vertebrate steroids are synthesized in molluscs and regulation of the endocrine system in molluscs is also unknown. By using our newly developed ELISA the present work investigates if yolk protein is a suitable......During recent years invertebrates and especially molluscs have received increasing attention in the field of endocrine disruption and development of OECD test guidelines to assess the effects of endocrine disrupting compounds (EDCs) in molluscs is under development. The development of standardized...... tests to detect effects of EDCs in molluscs has proved cumbersome due to lack of specific biomarkers and endpoints for endocrine effects. Intersex (presence of oocytes in the testis) and induction of vitellogenin (the yolk protein precursor in oviparous vertebrates) have been used as biomarkers for EDCs...

  9. Cellular effects of tributyltin (TBT) on the penis epithelium cells of prosobranchs ( Hinia reticulata and Ocinebrina aciculata)

    Science.gov (United States)

    Brick, M.; Deutsch, U.; Fioroni, P.

    1996-09-01

    Cytopathological effects on organelles of penis epithelium cells were investigated in prosobranchs that had been exposed for two weeks to three months to high TBT-concentrations in artificial seawater. TBT exposure damaged cell organelles, such as mitochondria, Golgi dictyosomes, endoplasmatic reticulum, and injured the cell membranes. In addition, atypical intercellular spaces were observed between the cells of the epithelial layer. Further cell alterations included the increase of residual bodies within the cells as well as structural changes of the basal lamina. The ultrastructural changes were compared with cell alterations of specimens which had been collected in a polluted environment on the coast of Brittany (France).

  10. Sensitization pattern of crustacean-allergic individuals can indicate allergy to molluscs

    DEFF Research Database (Denmark)

    Vidal, C; Bartolomé, B; Rodríguez, V

    2015-01-01

    This study investigated the sensitization pattern of crustacean-allergic patients according to tolerance to molluscs. Thirty-one patients with anaphylaxis to crustaceans (14 with mollusc allergy and 17 with mollusc tolerance) were studied using skin prick tests (SPTs), specific IgEs (sIgEs) and SDS-PAGE...

  11. [Contribution to the study of Microphallidae Travassos 1920 (trematoda). XXXII. Microphallus breviatus n. sp., a species with an abbreviated evolutive cycle from a Mediterranean pond in the Languedoc].

    Science.gov (United States)

    Deblock, S; Maillard, C

    1975-01-01

    Contribution to the study of Microphallidae Travassos, 1920 (Trematoda). XXXII. - Microphallus breviatus n. sp., a short life-cycle species of a mediterranean pond of Languedoc. The whole larval life-cycle of M. breviatus takes place in one host, Hydrobia ventrosa (Montagu), Mollusc Hydrobiidae. Hepato-pancreatic sporocysts produce morphologically altered xiphidio-cercariae which become encysted metacercariae in the sporocyts themselves. This species is defined in the genus by the anatomic characteristics of its cercariae and metacercariae, allied with its uncommon biology including two hosts only.

  12. Development and validation of OECD test guidelines on mollusc reproductive toxicity tests

    DEFF Research Database (Denmark)

    Lagadic, Laurent; Holbech, Henrik; hutchinson, tom

    the comparison of endpoints relevant for reproduction in invertebrates often shows a much higher sensitivity in molluscs vs. e.g. daphnids. The OECD test guideline programme has thus been extended to cover reproduction effects of chemicals in molluscs. Existing mollusc toxicity test protocols have been reviewed...... in an OECD Detailed Review Paper that identifies two relevant candidate species for developing freshwater tests: Potamopyrgus antipodarum and Lymnaea stagnalis. However, this review did not clarify which toxicity test design/conditions are the most appropriate for chemicals assessment. Therefore, a mollusc...... reproduction test guideline will be developed describing partial- and full- life-cycle test protocols in these species, so as to propose a balanced suite of apical mollusc toxicity tests applicable for the assessment of any type of chemical, including endocrine disruptors, as level 4 and 5 assays of the EDTA...

  13. Transcriptome of the Antarctic brooding gastropod mollusc Margarella antarctica.

    Science.gov (United States)

    Clark, Melody S; Thorne, Michael A S

    2015-12-01

    454 RNA-Seq transcriptome data were generated from foot tissue of the Antarctic brooding gastropod mollusc Margarella antarctica. A total of 6195 contigs were assembled de novo, providing a useful resource for researchers with an interest in Antarctic marine species, phylogenetics and mollusc biology, especially shell production. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Neuro-endocrine disruption in molluscs

    DEFF Research Database (Denmark)

    Holbech, Henrik; Bech Sanderhoff, Lene; Waller, Stine P.

    The Mollusca phylum is the second largest animal phylum with around 85,000 registered mollusc species and increasing attention to effects of chemicals on the molluscan endocrine system have been given during the last years. This includes initiation of the development of OECD test guidelines (TG...... efficient and fast in vivo system using embryos of the freshwater pulmonate gastropod Lymnaea stagnalis (the great pond snail). It is known that serotonin and dopamine are involved in many reproductive processes in molluscs Incl. egg maturation and spawning and that pedal ciliary activity causing L....... stagnalis embryos to rotate in the eggs is serotonin/dopamine regulated. We have developed a system to quantify embryo rotation and present results of exposure to serotonin, dopamine and different anti-depressive pharmaceuticals (e.g. selective serotonin reuptake inhibitors, SSRI´s) using the L. stagnalis...

  15. Mollusc reproductive toxicity tests - Development and validation of test guidelines

    DEFF Research Database (Denmark)

    Ducrot, Virginie; Holbech, Henrik; Kinnberg, Karin Lund

    . Draft standard operating procedures (SOPs) have been designed based upon literature and expert knowledge from project partners. Pre-validation studies have been implemented to validate the proposed test conditions and identify issues in performing the SOPs and analyzing test results. Pre-validation work......The Organisation for Economic Cooperation and Development is promoting the development and validation of mollusc toxicity tests within its test guidelines programme, eventually aiming for the standardization of mollusc apical toxicity tests. Through collaborative work between academia, industry...... and stakeholders, this study aims to develop innovative partial life-cycle tests on the reproduction of the freshwater gastropods Potamopyrgus antipodarum and Lymnaea stagnalis, which are relevant candidate species for the standardization of mollusc apical toxicity tests assessing reprotoxic effects of chemicals...

  16. Fossils mollusc asemblage found at Zagarzazu, marine Pleistocene, Uruguay

    International Nuclear Information System (INIS)

    Rojas, A. . E mail: alejandra@fcien.edu.uy

    2004-01-01

    There are presented the results of the paleoecological analysis of the mollusc assemblage found at Zagarzazu, Colonia department. The fossils are well preserved, arranged in thin shell-beds with some specimens in life position. The assemblage is indicative of higher temperatures than present, and a strong marine influence. It is important to stress that new thermophilic molluscs for the marine Quaternary were found and that this locality represents a new Pleistocene marine record in Uruguay [es

  17. Patterns of DNA barcode variation in Canadian marine molluscs.

    Science.gov (United States)

    Layton, Kara K S; Martel, André L; Hebert, Paul D N

    2014-01-01

    Molluscs are the most diverse marine phylum and this high diversity has resulted in considerable taxonomic problems. Because the number of species in Canadian oceans remains uncertain, there is a need to incorporate molecular methods into species identifications. A 648 base pair segment of the cytochrome c oxidase subunit I gene has proven useful for the identification and discovery of species in many animal lineages. While the utility of DNA barcoding in molluscs has been demonstrated in other studies, this is the first effort to construct a DNA barcode registry for marine molluscs across such a large geographic area. This study examines patterns of DNA barcode variation in 227 species of Canadian marine molluscs. Intraspecific sequence divergences ranged from 0-26.4% and a barcode gap existed for most taxa. Eleven cases of relatively deep (>2%) intraspecific divergence were detected, suggesting the possible presence of overlooked species. Structural variation was detected in COI with indels found in 37 species, mostly bivalves. Some indels were present in divergent lineages, primarily in the region of the first external loop, suggesting certain areas are hotspots for change. Lastly, mean GC content varied substantially among orders (24.5%-46.5%), and showed a significant positive correlation with nearest neighbour distances. DNA barcoding is an effective tool for the identification of Canadian marine molluscs and for revealing possible cases of overlooked species. Some species with deep intraspecific divergence showed a biogeographic partition between lineages on the Atlantic, Arctic and Pacific coasts, suggesting the role of Pleistocene glaciations in the subdivision of their populations. Indels were prevalent in the barcode region of the COI gene in bivalves and gastropods. This study highlights the efficacy of DNA barcoding for providing insights into sequence variation across a broad taxonomic group on a large geographic scale.

  18. Biomimetic and bio-inspired uses of mollusc shells.

    Science.gov (United States)

    Morris, J P; Wang, Y; Backeljau, T; Chapelle, G

    2016-06-01

    Climate change and ocean acidification are likely to have a profound effect on marine molluscs, which are of great ecological and economic importance. One process particularly sensitive to climate change is the formation of biominerals in mollusc shells. Fundamental research is broadening our understanding of the biomineralization process, as well as providing more informed predictions on the effects of climate change on marine molluscs. Such studies are important in their own right, but their value also extends to applied sciences. Biominerals, organic/inorganic hybrid materials with many remarkable physical and chemical properties, have been studied for decades, and the possibilities for future improved use of such materials for society are widely recognised. This article highlights the potential use of our understanding of the shell biomineralization process in novel bio-inspired and biomimetic applications. It also highlights the potential for the valorisation of shells produced as a by-product of the aquaculture industry. Studying shells and the formation of biominerals will inspire novel functional hybrid materials. It may also provide sustainable, ecologically- and economically-viable solutions to some of the problems created by current human resource exploitation. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. The use of yolk protein as biomarkers for endocrine disruption in molluscs

    DEFF Research Database (Denmark)

    Holbech, Henrik; Kinnberg, Karin Lund; Bjerregaard, Poul

    Invertebrates and especially molluscs have received increasing attention in relation to endocrine disrupting chemicals (EDs) during the last few years and the development of OECD test guidelines to assess the effect of EDs with molluscs are in progress. One of the main problems with the development...

  20. Ancient DNA analysis identifies marine mollusc shells as new metagenomic archives of the past.

    Science.gov (United States)

    Der Sarkissian, Clio; Pichereau, Vianney; Dupont, Catherine; Ilsøe, Peter C; Perrigault, Mickael; Butler, Paul; Chauvaud, Laurent; Eiríksson, Jón; Scourse, James; Paillard, Christine; Orlando, Ludovic

    2017-09-01

    Marine mollusc shells enclose a wealth of information on coastal organisms and their environment. Their life history traits as well as (palaeo-) environmental conditions, including temperature, food availability, salinity and pollution, can be traced through the analysis of their shell (micro-) structure and biogeochemical composition. Adding to this list, the DNA entrapped in shell carbonate biominerals potentially offers a novel and complementary proxy both for reconstructing palaeoenvironments and tracking mollusc evolutionary trajectories. Here, we assess this potential by applying DNA extraction, high-throughput shotgun DNA sequencing and metagenomic analyses to marine mollusc shells spanning the last ~7,000 years. We report successful DNA extraction from shells, including a variety of ancient specimens, and find that DNA recovery is highly dependent on their biomineral structure, carbonate layer preservation and disease state. We demonstrate positive taxonomic identification of mollusc species using a combination of mitochondrial DNA genomes, barcodes, genome-scale data and metagenomic approaches. We also find shell biominerals to contain a diversity of microbial DNA from the marine environment. Finally, we reconstruct genomic sequences of organisms closely related to the Vibrio tapetis bacteria from Manila clam shells previously diagnosed with Brown Ring Disease. Our results reveal marine mollusc shells as novel genetic archives of the past, which opens new perspectives in ancient DNA research, with the potential to reconstruct the evolutionary history of molluscs, microbial communities and pathogens in the face of environmental changes. Other future applications include conservation of endangered mollusc species and aquaculture management. © 2017 John Wiley & Sons Ltd.

  1. Plant indicator values as a tool for land mollusc autecology assessment

    Science.gov (United States)

    Horsák, Michal; Hájek, Michal; Tichý, Lubomír; Juřičková, Lucie

    2007-09-01

    The aim of this paper was to utilize Ellenberg's plant indicator system for assessing mollusc autecology and to highlight possibilities and advantages of that approach in the case of fen mollusc communities. Molluscs and plants from 137 fen sites in the Western Carpathian Mountains were recorded quantitatively from homogeneous areas of 16 m 2. Water conductivity and pH were measured in the field. Values of Ellenberg's "light, temperature, continentality, moisture, soil reaction, and nutrients" were estimated for each site. The whole data set was processed using ordinations (PCA, DCA, and CCA) and generalized additive models (GAMs). We observed a strong correlation between water pH and Ellenberg soil reaction estimated by plant indicator values ( r = 0.72, P < 0.001). Ellenberg soil reaction was found to be the best predictor of mollusc species composition, which expressed the main mineral-richness gradient. We found the existence of a second important gradient, the gradient of "light", expressing site and canopy openness. A tight correspondence between the results of species response curve modelling based on water conductivity and Ellenberg soil reaction confirmed that "soil reaction" does not express merely pH, but rather the total amount of calcium. We conclude that the Ellenberg's indicator system can be used to study the ecology of land molluscs, an important group of invertebrates in bioindication and nature conservation. Our data and approach could help design appropriate conservation management regimes for threatened snail species. We propose that our approach will be useful also in ecological studies of other animal groups.

  2. Concentration parameters for radionuclides by marine molluscs

    International Nuclear Information System (INIS)

    Nakahara, Motokazu; Makamura, Ryoichi; Suzuki, Yuzuru; Matsuba, Mitsue

    1994-01-01

    Accumulation of radionuclides from seawater and from food by marine molluscs was observed in the laboratory experiments to get bioconcentration parameters for the nuclides. The radionuclides investigated were 57 Co, 95m Tc, 103 Ru, 137 Cs, 65 Zn and 54 Mn. Several species of molluscs containing pelecypods, gastropods and cephalopod were used for the experimental organisms. For the uptake experiment from seawater, the organisms were kept for more than seven days in radioactive seawater containing those radionuclides together. Then the organisms were transferred into nonradioactive seawater to observe the loss of the nuclides from the organisms. Biphasic loss curves were observed for all of the nuclides. Bioconcentration parameters, such as uptake rate, excretion rate, biological half-life and concentration factor at steady state were estimated from the uptake and excretion curves of the nuclides by the organisms by applying an exponential model. In the uptake experiments from radioactive food, the phytoplankton (Tetraselmis tetrathele), the brown algae (Eisenia bicyclis) and the viscera of abalone (Haliotis discus) were fed to bivalves, herbivorous gastropods and carnivorous molluscs, respectively. After single feeding of the labelled food with the nuclides, retention of the nuclides in whole body of the organisms was followed for several weeks or more. The organisms showed relatively high retention of the nuclides in whole body, except 137 Cs and 54 Mn. Retention of 137 Cs and 54 Mn in the organisms one day after feeding of radioactive food was lower than 25% of the radioactivity dosed. (author)

  3. Infectious diseases of marine molluscs and host responses as revealed by genomic tools

    Science.gov (United States)

    Ford, Susan E.

    2016-01-01

    More and more infectious diseases affect marine molluscs. Some diseases have impacted commercial species including MSX and Dermo of the eastern oyster, QPX of hard clams, withering syndrome of abalone and ostreid herpesvirus 1 (OsHV-1) infections of many molluscs. Although the exact transmission mechanisms are not well understood, human activities and associated environmental changes often correlate with increased disease prevalence. For instance, hatcheries and large-scale aquaculture create high host densities, which, along with increasing ocean temperature, might have contributed to OsHV-1 epizootics in scallops and oysters. A key to understanding linkages between the environment and disease is to understand how the environment affects the host immune system. Although we might be tempted to downplay the role of immunity in invertebrates, recent advances in genomics have provided insights into host and parasite genomes and revealed surprisingly sophisticated innate immune systems in molluscs. All major innate immune pathways are found in molluscs with many immune receptors, regulators and effectors expanded. The expanded gene families provide great diversity and complexity in innate immune response, which may be key to mollusc's defence against diverse pathogens in the absence of adaptive immunity. Further advances in host and parasite genomics should improve our understanding of genetic variation in parasite virulence and host disease resistance. PMID:26880838

  4. Predicting the Response of Molluscs to the Impact of Ocean Acidification

    Directory of Open Access Journals (Sweden)

    John M. Wright

    2013-04-01

    Full Text Available Elevations in atmospheric carbon dioxide (CO2 are anticipated to acidify oceans because of fundamental changes in ocean chemistry created by CO2 absorption from the atmosphere. Over the next century, these elevated concentrations of atmospheric CO2 are expected to result in a reduction of the surface ocean waters from 8.1 to 7.7 units as well as a reduction in carbonate ion (CO32− concentration. The potential impact that this change in ocean chemistry will have on marine and estuarine organisms and ecosystems is a growing concern for scientists worldwide. While species-specific responses to ocean acidification are widespread across a number of marine taxa, molluscs are one animal phylum with many species which are particularly vulnerable across a number of life-history stages. Molluscs make up the second largest animal phylum on earth with 30,000 species and are a major producer of CaCO3. Molluscs also provide essential ecosystem services including habitat structure and food for benthic organisms (i.e., mussel and oyster beds, purification of water through filtration and are economically valuable. Even sub lethal impacts on molluscs due to climate changed oceans will have serious consequences for global protein sources and marine ecosystems.

  5. Predicting the Response of Molluscs to the Impact of Ocean Acidification

    Science.gov (United States)

    Parker, Laura M.; Ross, Pauline M.; O’Connor, Wayne A.; Pörtner, Hans O.; Scanes, Elliot; Wright, John M.

    2013-01-01

    Elevations in atmospheric carbon dioxide (CO2) are anticipated to acidify oceans because of fundamental changes in ocean chemistry created by CO2 absorption from the atmosphere. Over the next century, these elevated concentrations of atmospheric CO2 are expected to result in a reduction of the surface ocean waters from 8.1 to 7.7 units as well as a reduction in carbonate ion (CO32−) concentration. The potential impact that this change in ocean chemistry will have on marine and estuarine organisms and ecosystems is a growing concern for scientists worldwide. While species-specific responses to ocean acidification are widespread across a number of marine taxa, molluscs are one animal phylum with many species which are particularly vulnerable across a number of life-history stages. Molluscs make up the second largest animal phylum on earth with 30,000 species and are a major producer of CaCO3. Molluscs also provide essential ecosystem services including habitat structure and food for benthic organisms (i.e., mussel and oyster beds), purification of water through filtration and are economically valuable. Even sub lethal impacts on molluscs due to climate changed oceans will have serious consequences for global protein sources and marine ecosystems. PMID:24832802

  6. Review of the RNA Interference Pathway in Molluscs Including Some Possibilities for Use in Bivalves in Aquaculture

    Directory of Open Access Journals (Sweden)

    Leigh Owens

    2015-03-01

    Full Text Available Generalised reviews of RNA interference (RNAi in invertebrates, and for use in aquaculture, have taken for granted that RNAi pathways operate in molluscs, but inspection of such reviews show little specific evidence of such activity in molluscs. This review was to understand what specific research had been conducted on RNAi in molluscs, particularly with regard to aquaculture. There were questions of whether RNAi in molluscs functions similarly to the paradigm established for most eukaryotes or, alternatively, was it more similar to the ecdozoa and how RNAi may relate to disease control in aquaculture? RNAi in molluscs appears to have been only investigated in about 14 species, mostly as a gene silencing phenomenon. We can infer that microRNAs including let-7 are functional in molluscs. The genes/proteins involved in the actual RNAi pathways have only been rudimentarily investigated, so how homologous the genes and proteins are to other metazoa is unknown. Furthermore, how many different genes for each activity in the RNAi pathway are also unknown? The cephalopods have been greatly overlooked with only a single RNAi gene-silencing study found. The long dsRNA-linked interferon pathways seem to be present in molluscs, unlike some other invertebrates and could be used to reduce disease states in aquaculture. In particular, interferon regulatory factor genes have been found in molluscs of aquacultural importance such as Crassostrea, Mytilus, Pinctada and Haliotis. Two possible aquaculture scenarios are discussed, zoonotic norovirus and ostreid herpesvirus 1 to illustrate the possibilities. The entire field of RNAi in molluscs looks ripe for scientific exploitation and practical application.

  7. Effects of fluoxetine on the reproduction of two prosobranch mollusks: Potamopyrgus antipodarum and Valvata piscinalis

    International Nuclear Information System (INIS)

    Gust, M.; Buronfosse, T.; Giamberini, L.; Ramil, M.; Mons, R.; Garric, J.

    2009-01-01

    Fluoxetine is a widely used antidepressant, frequently found in aquatic ecosystems. We investigated its effects on two freshwater prosobranch gastropods: Valvata piscinalis (European valve snail) and Potamopyrgus antipodarum (New Zealand mudsnail), which have different reproductive modes. The fecundity of V. piscinalis (cumulate number of eggs at day 42) was not affected with an NOEC of 100 μg/L nominal concentration (69 μg/L measured concentration). The mudsnail P. antipodarum responded in a biphasic dose-effect curve at low concentrations. The cumulate number of neonates at day 42 had an LOEC of 100 μg/L (69 μg/L) and an NOEC of 33.3 μg/L (13 μg/L), whereas the embryos in the brood pouch at day 42 only showed an LOEC of 3.7 μg/L (1 μg/L). We also observed histological effects in P. antipodarum (gonadal thickness). Among the sexual steroids we measured only testosterone which varied, independent of reproduction. Moreover the use of two closely related species highlights the interspecific variability. - Fluoxetine has significant effects on the reproduction and development of some freshwater snails

  8. Effects of fluoxetine on the reproduction of two prosobranch mollusks: Potamopyrgus antipodarum and Valvata piscinalis

    Energy Technology Data Exchange (ETDEWEB)

    Gust, M. [Laboratoire d' ecotoxicologie, Cemagref, 3b quai Chauveau, CP 220, 69336 Lyon Cedex 09 (France)], E-mail: marion.gust@cemagref.fr; Buronfosse, T. [Laboratoire d' endocrinologie, Ecole Nationale Veterinaire de Lyon, avenue Bourgelat, 69280 Marcy l' Etoile (France)], E-mail: thierry.buronfosse@inserm.fr; Giamberini, L. [Laboratoire des interactions Ecotoxicologie, Biodiversite, Ecosystemes, CNRS UMR 7146, campus Bridoux, 57000 Metz (France)], E-mail: giamb@sciences.univ-metz.fr; Ramil, M. [Federal Institute of Hydrology (BFG), D-56068 Koblenz, Am Mainzer Tor 1 (Germany)], E-mail: mramil@usc.es; Mons, R. [Laboratoire d' ecotoxicologie, Cemagref, 3b quai Chauveau, CP 220, 69336 Lyon Cedex 09 (France)], E-mail: raphael.mons@cemagref.fr; Garric, J. [Laboratoire d' ecotoxicologie, Cemagref, 3b quai Chauveau, CP 220, 69336 Lyon Cedex 09 (France)], E-mail: jeanne.garric@cemagref.fr

    2009-02-15

    Fluoxetine is a widely used antidepressant, frequently found in aquatic ecosystems. We investigated its effects on two freshwater prosobranch gastropods: Valvata piscinalis (European valve snail) and Potamopyrgus antipodarum (New Zealand mudsnail), which have different reproductive modes. The fecundity of V. piscinalis (cumulate number of eggs at day 42) was not affected with an NOEC of 100 {mu}g/L nominal concentration (69 {mu}g/L measured concentration). The mudsnail P. antipodarum responded in a biphasic dose-effect curve at low concentrations. The cumulate number of neonates at day 42 had an LOEC of 100 {mu}g/L (69 {mu}g/L) and an NOEC of 33.3 {mu}g/L (13 {mu}g/L), whereas the embryos in the brood pouch at day 42 only showed an LOEC of 3.7 {mu}g/L (1 {mu}g/L). We also observed histological effects in P. antipodarum (gonadal thickness). Among the sexual steroids we measured only testosterone which varied, independent of reproduction. Moreover the use of two closely related species highlights the interspecific variability. - Fluoxetine has significant effects on the reproduction and development of some freshwater snails.

  9. Concentration parameters for radionuclides by marine molluscs

    Energy Technology Data Exchange (ETDEWEB)

    Nakahara, Motokazu; Makamura, Ryoichi; Suzuki, Yuzuru; Matsuba, Mitsue [National Inst. of Radiological Sciences, Nakaminato, Ibaraki (Japan). Nakaminato Lab. Branch Office

    1994-03-01

    Accumulation of radionuclides from seawater and from food by marine molluscs was observed in the laboratory experiments to get bioconcentration parameters for the nuclides. The radionuclides investigated were {sup 57}Co, {sup 95m}Tc, {sup 103}Ru, {sup 137}Cs, {sup 65}Zn and {sup 54}Mn. Several species of molluscs containing pelecypods, gastropods and cephalopod were used for the experimental organisms. For the uptake experiment from seawater, the organisms were kept for more than seven days in radioactive seawater containing those radionuclides together. Then the organisms were transferred into nonradioactive seawater to observe the loss of the nuclides from the organisms. Biphasic loss curves were observed for all of the nuclides. Bioconcentration parameters, such as uptake rate, excretion rate, biological half-life and concentration factor at steady state were estimated from the uptake and excretion curves of the nuclides by the organisms by applying an exponential model. In the uptake experiments from radioactive food, the phytoplankton (Tetraselmis tetrathele), the brown algae (Eisenia bicyclis) and the viscera of abalone (Haliotis discus) were fed to bivalves, herbivorous gastropods and carnivorous molluscs, respectively. After single feeding of the labelled food with the nuclides, retention of the nuclides in whole body of the organisms was followed for several weeks or more. The organisms showed relatively high retention of the nuclides in whole body, except {sup 137}Cs and {sup 54}Mn. Retention of {sup 137}Cs and {sup 54}Mn in the organisms one day after feeding of radioactive food was lower than 25% of the radioactivity dosed. (author).

  10. FMRFamide-like immunoreactivity in the central nervous system of the cephalopod mollusc, Idiosepius notoides

    DEFF Research Database (Denmark)

    Wollesen, Tim; Loesel, R.; Wanninger, Andreas Wilhelm Georg

    2008-01-01

    For more than a century, cephalopod molluscs have been the subject of extensive studies with respect to their complex neuroanatomy and behavior. In comparison to gastropod molluscs surprisingly little work has been carried out on the characterization of neurons in the central nervous system (CNS...

  11. EU Regulatory Risk Management of Marine Biotoxins in the Marine Bivalve Mollusc Food-Chain.

    Science.gov (United States)

    O'Mahony, Micheál

    2018-03-10

    Food safety risk assessment in the European Union (EU) recognises consumer illness that arises from marine biotoxins as a risk associated with bivalve mollusc consumption. EU food regulations contain various general food safety obligations, which should contribute significantly to managing this risk. EU food regulations additionally impose various specific obligations on both Food Business Operators and Competent Authorities in order to manage the marine biotoxin food safety risk in the bivalve mollusc food-chain. These have a particular focus on the pre-harvest component of the food-chain. A central component of these specific systems is the requirement for ongoing monitoring of phytoplankton and biotoxin concentrations in water and molluscs, respectively. This monitoring explicitly brings a potential outcome of closing production areas delineated by classification to prohibit the harvest of bivalve molluscs as food from those areas when acceptable biotoxin concentrations are exceeded. This review considers the utility of these systems, at conceptual and practical levels, and explores their contribution to an effective regulatory risk management approach.

  12. INVENTORY AND DISTRIBUTION OF MOLLUSC IN CORAL REEF OF BACAN ISLAND WATERS, NORTH MALUKU PROVINCE

    Directory of Open Access Journals (Sweden)

    Hendrik A.W. Cappenberg

    2017-11-01

    Full Text Available Bacan Island waters of North Maluku Province consisted of three main tropical ecosystems, namely mangrove, seagrass, and coral reef with the highest marine biodiversity. Mollusc is a group of marine fauna that most of them associated with coral reef.  However, little is known about their information in the Bacan Island due to lack of study conducted there. The purpose of this study is to observe the diversity and distribution of mollusc fauna in the coral reef flat of Bacan Island. Mollusc inventory was done using Rapid Reef Resource Assessment (RRA method by snorkling in the reefs of east coast (25 sites and west coast (10 sites of Bacan Island. The molluscs found were directly identified into species level and recorded.  Results of inventory show that there are 47 species belong to 19 families with the family of Muricidae is the highest diversity (6 species, while the lowest are Buccinidae, Bursidae, Haliotidae, Olividae, Cardiidae, Isognomonidae and Spondylidae, respectively with only 1 species in each of those families. The highest species number of mollusc was distributed along the east coast of the island (40 species, and the lowest one was in the west coast (37 species. Some species such as Tridacna spp., Pinctada margaritifera and Pteria penguin are important species, because they have economical values. Keywords:       biodiversity, molluscs, coral reef, Bacan Island, North Maluku

  13. Large-Scale Trade in Legally Protected Marine Mollusc Shells from Java and Bali, Indonesia.

    Science.gov (United States)

    Nijman, Vincent; Spaan, Denise; Nekaris, K Anne-Isola

    2015-01-01

    Tropical marine molluscs are traded globally. Larger species with slow life histories are under threat from over-exploitation. We report on the trade in protected marine mollusc shells in and from Java and Bali, Indonesia. Since 1987 twelve species of marine molluscs are protected under Indonesian law to shield them from overexploitation. Despite this protection they are traded openly in large volumes. We collected data on species composition, origins, volumes and prices at two large open markets (2013), collected data from wholesale traders (2013), and compiled seizure data by the Indonesian authorities (2008-2013). All twelve protected species were observed in trade. Smaller species were traded for Java and Bali, but the trade involves networks stretching hundreds of kilometres throughout Indonesia. Wholesale traders offer protected marine mollusc shells for the export market by the container or by the metric ton. Data from 20 confiscated shipments show an on-going trade in these molluscs. Over 42,000 shells were seized over a 5-year period, with a retail value of USD700,000 within Indonesia; horned helmet (Cassis cornuta) (>32,000 shells valued at USD500,000), chambered nautilus (Nautilus pompilius) (>3,000 shells, USD60,000) and giant clams (Tridacna spp.) (>2,000 shells, USD45,000) were traded in largest volumes. Two-thirds of this trade was destined for international markets, including in the USA and Asia-Pacific region. We demonstrated that the trade in protected marine mollusc shells in Indonesia is not controlled nor monitored, that it involves large volumes, and that networks of shell collectors, traders, middlemen and exporters span the globe. This impedes protection of these species on the ground and calls into question the effectiveness of protected species management in Indonesia; solutions are unlikely to be found only in Indonesia and must involve the cooperation of importing countries.

  14. Large-Scale Trade in Legally Protected Marine Mollusc Shells from Java and Bali, Indonesia

    Science.gov (United States)

    Nijman, Vincent; Spaan, Denise; Nekaris, K. Anne-Isola

    2015-01-01

    Background Tropical marine molluscs are traded globally. Larger species with slow life histories are under threat from over-exploitation. We report on the trade in protected marine mollusc shells in and from Java and Bali, Indonesia. Since 1987 twelve species of marine molluscs are protected under Indonesian law to shield them from overexploitation. Despite this protection they are traded openly in large volumes. Methodology/Principal Findings We collected data on species composition, origins, volumes and prices at two large open markets (2013), collected data from wholesale traders (2013), and compiled seizure data by the Indonesian authorities (2008–2013). All twelve protected species were observed in trade. Smaller species were traded for trade involves networks stretching hundreds of kilometres throughout Indonesia. Wholesale traders offer protected marine mollusc shells for the export market by the container or by the metric ton. Data from 20 confiscated shipments show an on-going trade in these molluscs. Over 42,000 shells were seized over a 5-year period, with a retail value of USD700,000 within Indonesia; horned helmet (Cassis cornuta) (>32,000 shells valued at USD500,000), chambered nautilus (Nautilus pompilius) (>3,000 shells, USD60,000) and giant clams (Tridacna spp.) (>2,000 shells, USD45,000) were traded in largest volumes. Two-thirds of this trade was destined for international markets, including in the USA and Asia-Pacific region. Conclusions/Significance We demonstrated that the trade in protected marine mollusc shells in Indonesia is not controlled nor monitored, that it involves large volumes, and that networks of shell collectors, traders, middlemen and exporters span the globe. This impedes protection of these species on the ground and calls into question the effectiveness of protected species management in Indonesia; solutions are unlikely to be found only in Indonesia and must involve the cooperation of importing countries. PMID:26717021

  15. Petroleum hydrocarbon concentrations in eight mollusc species along Tamilnadu coast, Bay of Bengal, India.

    Science.gov (United States)

    Veerasingam, S; Venkatachalapathy, R; Sudhakar, S; Raja, P; Rajeswari, V

    2011-01-01

    Eight mollusc species and sediment samples collected from three different stations along Tamilnadu coast, Bay of Bengal, India were analysed for the levels of petroleum hydrocarbons to elucidate the status of the petroleum residues in mollusc meant for human consumption. The concentrations of petroleum hydrocarbons in sediments along Tamilnadu coast varied from 5.04-25.5 microg/g dw (dry weight). High concentration of petroleum hydrocarbons in the sediment of Uppanar estuary (25.5 +/- 1.45 microg/g dw) was perhaps land and marine based anthropogenic sources of this region. The petroleum hydrocarbon residues in eight mollusc species collected from Uppanar, Vellar and Coleroon estuaries varied between 2.44-6.04 microg/g ww (wet weight). Although the concentration of petroleum hydrocarbons in sediment of the Uppanar region was markedly higher than the background, the petroleum hydrocarbon residues in mollusc collected from Uppanar estuary did not suggest bioaccumulation. The results signified that industrial growth has affected the aquatic environments and regular monitoring will help to adopt stringent pollution control measures for better management of the aquatic region.

  16. EU Regulatory Risk Management of Marine Biotoxins in the Marine Bivalve Mollusc Food-Chain

    Directory of Open Access Journals (Sweden)

    Micheál O’Mahony

    2018-03-01

    Full Text Available Food safety risk assessment in the European Union (EU recognises consumer illness that arises from marine biotoxins as a risk associated with bivalve mollusc consumption. EU food regulations contain various general food safety obligations, which should contribute significantly to managing this risk. EU food regulations additionally impose various specific obligations on both Food Business Operators and Competent Authorities in order to manage the marine biotoxin food safety risk in the bivalve mollusc food-chain. These have a particular focus on the pre-harvest component of the food-chain. A central component of these specific systems is the requirement for ongoing monitoring of phytoplankton and biotoxin concentrations in water and molluscs, respectively. This monitoring explicitly brings a potential outcome of closing production areas delineated by classification to prohibit the harvest of bivalve molluscs as food from those areas when acceptable biotoxin concentrations are exceeded. This review considers the utility of these systems, at conceptual and practical levels, and explores their contribution to an effective regulatory risk management approach.

  17. Detecting the presence of infectious hepatitis A virus in molluscs positive to RT-nested-PCR

    NARCIS (Netherlands)

    Medici, de D.; Croci, L.; Pasquale, di S.; Fiore, A.; Toti, L.

    2001-01-01

    Aims: The objective of this study was to det. the presence of infectious hepatitis A virus (HAV) in molluscs naturally contaminated with viral HAV-RNA. Methods and Results: One hundred and forty-two mollusc samples were analyzed for the presence of viral HAV-RNA using RT-nested-PCR; pos. samples

  18. Ancient DNA analysis identifies marine mollusc shells as new metagenomic archives of the past

    DEFF Research Database (Denmark)

    Der Sarkissian, Clio; Pichereau, Vianney; Dupont, Catherine

    2017-01-01

    Marine mollusc shells enclose a wealth of information on coastal organisms and their environment. Their life history traits as well as (palaeo-) environmental conditions, including temperature, food availability, salinity and pollution, can be traced through the analysis of their shell (micro...... extraction, high-throughput shotgun DNA sequencing and metagenomic analyses to marine mollusc shells spanning the last ~7,000 years. We report successful DNA extraction from shells, including a variety of ancient specimens, and find that DNA recovery is highly dependent on their biomineral structure......, carbonate layer preservation and disease state. We demonstrate positive taxonomic identification of mollusc species using a combination of mitochondrial DNA genomes, barcodes, genome-scale data and metagenomic approaches. We also find shell biominerals to contain a diversity of microbial DNA from the marine...

  19. Shell biofilm-associated nitrous oxide production in marine molluscs

    DEFF Research Database (Denmark)

    Heisterkamp, I.M.; Schramm, Andreas; Larsen, Lone Heimann

    2013-01-01

    Emission of the greenhouse gas nitrous oxide (N2O) from freshwater and terrestrial invertebrates has exclusively been ascribed to N2O production by ingested denitrifying bacteria in the anoxic gut of the animals. Our study of marine molluscs now shows that also microbial biofilms on shell surfaces...... are important sites of N2O production. The shell biofilms of Mytilus edulis, Littorina littorea and Hinia reticulata contributed 18-94% to the total animal-associated N2O emission. Nitrification and denitrification were equally important sources of N2O in shell biofilms as revealed by 15N-stable isotope...... mollusc species. Ammonium excretion by the animals was found to be sufficient to sustain N2O production in the shell biofilm. Apparently, the animals provide a nutrient-enriched microenvironment that stimulates growth and N2O production of the shell biofilm. This animal-induced stimulation...

  20. Predicting the effects of ocean acidification on predator-prey interactions: a conceptual framework based on coastal molluscs.

    Science.gov (United States)

    Kroeker, Kristy J; Sanford, Eric; Jellison, Brittany M; Gaylord, Brian

    2014-06-01

    The influence of environmental change on species interactions will affect population dynamics and community structure in the future, but our current understanding of the outcomes of species interactions in a high-CO2 world is limited. Here, we draw upon emerging experimental research examining the effects of ocean acidification on coastal molluscs to provide hypotheses of the potential impacts of high-CO2 on predator-prey interactions. Coastal molluscs, such as oysters, mussels, and snails, allocate energy among defenses, growth, and reproduction. Ocean acidification increases the energetic costs of physiological processes such as acid-base regulation and calcification. Impacted molluscs can display complex and divergent patterns of energy allocation to defenses and growth that may influence predator-prey interactions; these include changes in shell properties, body size, tissue mass, immune function, or reproductive output. Ocean acidification has also been shown to induce complex changes in chemoreception, behavior, and inducible defenses, including altered cue detection and predator avoidance behaviors. Each of these responses may ultimately alter the susceptibility of coastal molluscs to predation through effects on predator handling time, satiation, and search time. While many of these effects may manifest as increases in per capita predation rates on coastal molluscs, the ultimate outcome of predator-prey interactions will also depend on how ocean acidification affects the specified predators, which also exhibit complex responses to ocean acidification. Changes in predator-prey interactions could have profound and unexplored consequences for the population dynamics of coastal molluscs in a high-CO2 ocean. © 2014 Marine Biological Laboratory.

  1. Large-Scale Trade in Legally Protected Marine Mollusc Shells from Java and Bali, Indonesia.

    Directory of Open Access Journals (Sweden)

    Vincent Nijman

    Full Text Available Tropical marine molluscs are traded globally. Larger species with slow life histories are under threat from over-exploitation. We report on the trade in protected marine mollusc shells in and from Java and Bali, Indonesia. Since 1987 twelve species of marine molluscs are protected under Indonesian law to shield them from overexploitation. Despite this protection they are traded openly in large volumes.We collected data on species composition, origins, volumes and prices at two large open markets (2013, collected data from wholesale traders (2013, and compiled seizure data by the Indonesian authorities (2008-2013. All twelve protected species were observed in trade. Smaller species were traded for 32,000 shells valued at USD500,000, chambered nautilus (Nautilus pompilius (>3,000 shells, USD60,000 and giant clams (Tridacna spp. (>2,000 shells, USD45,000 were traded in largest volumes. Two-thirds of this trade was destined for international markets, including in the USA and Asia-Pacific region.We demonstrated that the trade in protected marine mollusc shells in Indonesia is not controlled nor monitored, that it involves large volumes, and that networks of shell collectors, traders, middlemen and exporters span the globe. This impedes protection of these species on the ground and calls into question the effectiveness of protected species management in Indonesia; solutions are unlikely to be found only in Indonesia and must involve the cooperation of importing countries.

  2. Biomarkers of metabolism disturbance in bivalve molluscs induced by environmental pollution with processed by-products of oil

    Directory of Open Access Journals (Sweden)

    E. V. Sukharenko

    2017-05-01

    Full Text Available Processed by-products of oil are the most common pollutants in all river and sea water. The increase in oxidative stress in bivalve molluscs was studied in both tissues of the hepatopancreas and the gill. The model for artificial treatment with processed by-products of oil was performed in a laboratory experiment with the river mollusc Dreissena polymorpha Pallas, 1771. The exposure of the molluscs over 28 days to mazut 50 mg/l induced significant increase of both final product of lipid peroxidation (LPO and antioxidant enzime activity. A significant increase in LPO was observed in the hepatopancreas and gill of D. polymorpha treated with mazut compared to the control group. Antioxidant enzyme activity of cartalase, supeoxide dismutase, glutathione reductase and glutathione-S-transferase showed a greater increase (by almost 1.5 times in the hepatopancreas than in the gill of D. polymorpha. A similar LPO growth and modulation of antioxidant enzyme activity were determined in the hepatopancreas and gill of the mussel Mytilus galloprovincialis Lamarck, 1879 collected in an area polluted with resins, hydrocarbons and asphaltenes, Donuzlav lake in the Kerch gulf. Varied cellular reactivation of the antioxidant enzyme system in the hepatopancreas rather than the gill was observed in both kinds of mollusc Dreissena and Mytilus. The obtained results are evidence of the higher sensitivity of the hepatopancreas cells of bivalve molluscs to organic pollutants compared to the gill cells.

  3. The ecology, evolution, impacts and management of host-parasite interactions of marine molluscs.

    Science.gov (United States)

    Coen, Loren D; Bishop, Melanie J

    2015-10-01

    Molluscs are economically and ecologically important components of aquatic ecosystems. In addition to supporting valuable aquaculture and wild-harvest industries, their populations determine the structure of benthic communities, cycling of nutrients, serve as prey resources for higher trophic levels and, in some instances, stabilize shorelines and maintain water quality. This paper reviews existing knowledge of the ecology of host-parasite interactions involving marine molluscs, with a focus on gastropods and bivalves. It considers the ecological and evolutionary impacts of molluscan parasites on their hosts and vice versa, and on the communities and ecosystems in which they are a part, as well as disease management and its ecological impacts. An increasing number of case studies show that disease can have important effects on marine molluscs, their ecological interactions and ecosystem services, at spatial scales from centimeters to thousands of kilometers and timescales ranging from hours to years. In some instances the cascading indirect effects arising from parasitic infection of molluscs extend well beyond the temporal and spatial scales at which molluscs are affected by disease. In addition to the direct effects of molluscan disease, there can be large indirect impacts on marine environments resulting from strategies, such as introduction of non-native species and selective breeding for disease resistance, put in place to manage disease. Much of our understanding of impacts of molluscan diseases on the marine environment has been derived from just a handful of intensively studied marine parasite-host systems, namely gastropod-trematode, cockle-trematode, and oyster-protistan interactions. Understanding molluscan host-parasite dynamics is of growing importance because: (1) expanding aquaculture; (2) current and future climate change; (3) movement of non-native species; and (4) coastal development are modifying molluscan disease dynamics, ultimately leading to

  4. Contamination of raw bivalve molluscs available in Poland between 2009 and 2013 with marine biotoxins

    Directory of Open Access Journals (Sweden)

    Michalski Mirosław

    2016-12-01

    Full Text Available Introduction: Growing consumption of shellfish is associated with an increased risk of food poisoning. The study was carried out on live bivalve molluscs available on the Polish market between 2009 and 2013. Material and Methods: ELISA was used for the determination of the following marine biotoxins: paralytic shellfish poison (PSP, amnaesic shellfish poison (ASP, and diarrhoeic shellfish poison (DSP. The molluscs, of which seven species were examined, were obtained from wholesale companies and markets. Results: Marine biotoxins were detected below the permitted levels in 67.6% of the samples. The maximum amounts of PSP and ASP biotoxins were found in great scallops (532.6 μg/kg and 1.0 mg/kg respectively and the peak for DSP was in blue mussels (107 μg/kg. Conclusion: The analysis of toxicological status of raw bivalve molluscs available on the market in Poland indicates that they are safe for consumers.

  5. Molluscs production associated to lunar-tide cycle: a case study in Paraíba State under ethnoecology viewpoint

    Directory of Open Access Journals (Sweden)

    Alves Rômulo RN

    2006-06-01

    Full Text Available Abstract Molluscs have been for a long time a very important food resource for humans. Therefore, oysters, clams, and mussels are highly required at seafood markets. Like any commercial food, it is necessary that molluscs present good quality standards, concerning some criteria such as amount of meat and appearance. In bivalves, condition index or fattening index is considered a satisfactory method for estimating the amount of meat related to the shell cavity. Molluscs gatherers of Paraíba State coast, northeastern Brazil, state that molluscan meat production increases during spring tide (designated by them as maré de lançamento in opposition to the meat decrease which happens during neap tide (maré de quebramento (they are designated technically in Portuguese as maré de sizígia and maré de quadratura, respectively. Weperformed a survey on the production of unha-de-velho or 'oldman'snail' (Tagelus plebeius caught by molluscs gatherers in the estuary of River Paraíba do Norte, by observing locally their work, applying questionnaires, searching for a possible scientific relation of that molluscs condition to the gatherers empirical statement. Thus, we estimatedthe molluscs condition index through the method of solids percentage determination. We studied their work and the molluscs condition index during a full lunar-tide cycle. Determinations were carried out between 2nd September and 20th October, 1998, through 20 catches performed to obtain condition index from 400 bivalves. We observed that several biotic and abiotic ecological factors, namely reproduction cycle, biochemical components variations, animal size, and even parasitism, may affect the animal condition index. Despite this aspect, our present results confirmed a high overlapping (80% of the condition index curve with lunar-tide cycle, in agreement with the gatherers statement. Although we recognize the need for formulating and testing other hypotheses, we consider a priori that

  6. Labelling and Marketing of Bivalve and Gastropod Molluscs Retailed in Sardinia, Italy Between 2009 and 2013.

    Science.gov (United States)

    Meloni, Domenico

    2015-05-28

    The aim of the present survey was to investigate the correct enforcement of the Community rules on the labelling and marketing of bivalve and gastropod molluscs retailed in Sardinia, Italy between 2009 and 2013. A total of 1500 packages and labels for live bivalve and gastropod molluscs were considered. A total of 375 labels (25%) presented non-compliance concerning the wrong trade name and additional wrong or missing information. The highest percentage of anomalous labels has been detected in small-scale retail shops (35%) and open-air markets (25%) compared with the big retailing chains (20%). The 5% of packages were not in compliance with the European Community rules on packaging of bivalve and gastropod molluscs. The high percentage of non-compliance with the European regulations on labelling results is a strong limitation for the consumers and highlights the need to improve the control system about labelling of seafood products.

  7. Mollusc diversity associated with the non-indigenous macroalga Asparagopsis armata Harvey, 1855 along the Atlantic coast of the Iberian Peninsula.

    Science.gov (United States)

    Rubal, Marcos; Costa-Garcia, Ricardo; Besteiro, Celia; Sousa-Pinto, Isabel; Veiga, Puri

    2018-05-01

    The aims of this study were to explore mollusc assemblages associated with the non-indigenous macroalga Asparagopsis armata, to compare them with those on other macroalgae at the study region and to explore potential differences on mollusc assemblages between two regions in the Atlantic coast of the Iberian Peninsula, where A. armata is present. To achieve this, at each region, four intertidal shores were sampled. Twenty-nine mollusc species were reported and thus, A. armata harboured similar or higher diversity than other annual macroalgae in this area. When compared with perennial macroalgae, results depend on the species and studied area. Moreover, significant differences in structure of mollusc assemblages between the two studied regions were found. However, these were due to differences in the relative abundance of species rather than the presence of exclusive species at each region. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Prosobranch snails as test organisms for the assessment of endocrine active chemicals--an overview and a guideline proposal for a reproduction test with the freshwater mudsnail Potamopyrgus antipodarum.

    Science.gov (United States)

    Duft, Martina; Schmitt, Claudia; Bachmann, Jean; Brandelik, Cornelius; Schulte-Oehlmann, Ulrike; Oehlmann, Jörg

    2007-02-01

    Recently, prosobranch snails have been recommended as promising candidates for test organisms for the assessment of endocrine active chemicals. Three prosobranch snail species, the freshwater mudsnail Potamopyrgus antipodarum, the freshwater ramshorn snail Marisa cornuarietis, and the marine netted whelk Nassarius reticulatus are portrayed and their respective biotests are presented together with results of laboratory experiments and biological effect monitoring surveys in the field. All characterized species are highly sensitive toward xeno-androgens [triphenyltin (TPT), tributyltin (TBT), methyltestosterone (MT) and fenarimol (FEN)], and xeno-estrogens [bisphenol A (BPA), octylphenol (OP), ethinylestradiol], and show effects at environmentally relevant, rather low concentrations in laboratory experiments. For exposure to the xeno-androgen TPT, EC(10) values range between 15.9 and 29.0 ng as Sn/L (sediment 0.03 mug as Sn/kg), for TBT, EC(10) values are found between 3.42 and 37.8 ng as Sn/L (sediment 2.98 microg as Sn/kg) and effect concentrations for FEN are calculated as 18.6 ng/L (EC(10)) and 0.19 microg/kg (EC(50) sediment; EC(10) not calculable). Exposure to xeno-estrogens yielded EC(10 )values of 13.9 ng/L (0.19 microg/kg) for BPA, a NOEC of <1 microg/L (EC(10) of 0.004 microg/kg) for OP and a NOEC of 1 ng/l (EC(10) sediment of 2.2 microg/kg) for ethinylestradiol. Responses to androgens comprised the development of imposex and the reduction of fertility or embryo production, effects of estrogens included the stimulation of egg production and embryo production, and the increased weight of glands. Also, biological effect monitoring studies with P. antipodarum and N. reticulatus in several rivers or estuarine areas revealed the capacity of the biotests to detect an androgenic or estrogenic potential of sediment samples. A comparison of the three test species with regard to sensitivity and practical aspects in routine application favors the freshwater mudsnail P

  9. Labelling and marketing of bivalve and gastropod molluscs retailed in Sardinia, Italy between 2009 and 2013

    Directory of Open Access Journals (Sweden)

    Domenico Meloni

    2015-06-01

    Full Text Available The aim of the present survey was to investigate the correct enforcement of the Community rules on the labelling and marketing of bivalve and gastropod molluscs retailed in Sardinia, Italy between 2009 and 2013. A total of 1500 packages and labels for live bivalve and gastropod molluscs were considered. A total of 375 labels (25% presented non-compliance concerning the wrong trade name and additional wrong or missing information. The highest percentage of anomalous labels has been detected in small-scale retail shops (35% and open-air markets (25% compared with the big retailing chains (20%. The 5% of packages were not in compliance with the European Community rules on packaging of bivalve and gastropod molluscs. The high percentage of non-compliance with the European regulations on labelling results is a strong limitation for the consumers and highlights the need to improve the control system about labelling of seafood products.

  10. Concentration peculiarities of radionuclides by freshwater molluscs of Chernobyl NPP exclusion zone

    International Nuclear Information System (INIS)

    Gudkov, D.I.; Kuz'menko, M.I.; Nazarov, A.B.; Derevets, V.V.

    2001-01-01

    The results of radionuclides 90 Sr and 137 Cs content in molluscs tissue of water objects within Chernobyl NPP exclusion zone has been analysed. The age dynamics of radionuclides content in some species of Gastropoda was studied

  11. Fauna of gastropod molluscs in the Curonian Lagoon littoral biotopes (Baltic Sea, Kaliningrad region, Russia

    Directory of Open Access Journals (Sweden)

    Dmitry Filippenko

    2011-12-01

    Full Text Available A survey of the gastropod mollusc fauna in the coastal waters of the southern part of the Curonian Lagoon (Kaliningrad region, Russia were carried out. Study revealed 34 aquatic gastropods representing 30% of Prosobranchia and 70% of Pulmonata. Obtained data showed higher mollusc diversity in the littoral biotopes in comparison with open areas of the Lagoon. The fauna is represented by a typical Central European species complex of freshwater gastropods. The reed zone along the coastline in the Lagoon functions as a barrier and provides shallow water habitats with slow moving and warmer water, where maximum gastropod species concentrate.

  12. Eye structure and vision in the freshwater pulmonate mollusc Planorbarius corneus

    NARCIS (Netherlands)

    Zhukov, VV; Bobkova, MB; Vakolyuk, IA

    2002-01-01

    The structure of the mollusc Planorbarius corneus eye was studied using light and electron microscopy. The eye consists of the cornea, eye lens of non-spherical shape, and the vitreous body tightly bound to it, as well as of a monolayer non-inverted retina composed of photoreceptor and supporting

  13. [Distribution of acetylcholinesterase activity in the digestive system of the gastropod molluscs Littorina littorea and Achatina fulica].

    Science.gov (United States)

    Zaĭtseva, O V; Kuznetsova, T V

    2008-01-01

    With the use of the histochemical procedure for the demonstration of acetylcholinesterase (AchE) activity, the distribution cholinergic regulatory elements was studied in the esophagus, the pharynx, the stomach, the liver (the digestive gland) and the intestine in sea and terrestrial gastropod molluscs that differed in their general organization level, lifestyle, habitat and feeding type. In both molluscs, all the parts of the digestive tract contained the significant amount of intraepithelial AchE-positive cells of the open type, single subepithelial neurons and the nervous fibers localized among the muscle cells of the wall of the organs. The basal processes of the AchE-positive intraepithelial cells were shown to form the intraepithelial nerve plexus and to pass under the epithelium. The peculiarities and common principles in the distribution of the nervous elements detected, their possible function and the regulatory role in the digestion in gastropod molluscs and other animals are discussed.

  14. The Mg - SST relationship in mollusc shells: is there a rule? Examples from three tropical species

    Science.gov (United States)

    Lazareth, C. E.; Guzmán, N.; Lecornec, F.; Cabioch, G.; Ortlieb, L.

    2009-04-01

    The geochemistry of mollusc shells is currently viewed as a powerful tool for paleoenvironmental reconstructions. Indeed, molluscs are ubiquitous animals, with a worldly geographical and environmental distribution, providing various environmental records. Moreover, mollusc shells are abundantly found in fossil and archaeological settings. In the paleoclimatic reconstructions, the sea-surface temperatures (SST) are a key parameter. If shell stable oxygen isotope signatures can provide accurate SST records, this proxy is also influenced by the water isotopic composition. To find another tracer which would depend on the SST solely, the relationship between Mg content changes in mollusc shell and SST has been investigated for a few years. Nevertheless, if the reliability of shell Mg as SST tracer has been proven in some species, this is clearly not a "universal" and definitive rule. To reconstruct the past tropical SSTs, Mg calibration studies were undertaken on Concholepas concholepas (gastropod, South America), Protothaca thaca (bivalve, South America) and Tridacna squamosa (bivalve, New Caledonia). The very high-resolution (infra-daily) analyses of the C. concholepas gastropod revealed a significant metabolism control, at the nyctemeral scale, on the Mg incorporation into the calcite shell layer. Over a two months period, the Mg fluctuations in C. concholepas shell do not match with the SST instrumental measurements. Mg content changes along the aragonitic shell growth axis of several living P. thaca from a same Peruvian site are significantly different indicating no relationship between Mg and SST. The Mg variations measured in a Chilean P. thaca shell are, surprisingly, similar to variations of the instrumental SST. Unless this quite reliable relationship between P. thaca shell and SST is confirmed, and that the inter-site difference in Mg response to environmental forcing is understood, P. thaca shell Mg cannot be used as SST proxy. Lastly, a preliminary work

  15. Lipids from the nacreous and prismatic layers of two Pteriomorpha Mollusc shells

    Science.gov (United States)

    Farre, B.; Dauphin, Y.

    2009-04-01

    Mollusc shells are the best-known Ca-carbonate biominerals. They are commonly described as a mineralized two layered structure: an outer layer composed of calcite prismatic units, and an internal layer composed of tablets of aragonite: the nacreous layer. An external organic layer (periostracum) is present in most taxa. However, the most common structure in the Mollusc shell is the aragonite crossed lamellar layer, but aragonite prisms, calcite foliated layers and homogeneous layers have been also described by Boggild (1930) in all the Mollusc orders. Since, more detailed descriptions of Bivalve shells have been done (Taylor et al., 1969, 1973). Despite the nacroprismatic arrangement is rare, calcite prismatic and aragonite nacreous layers are the best studied because of their simple 3D structure and large units. Among these Molluscs, some Bivalve species composed of these two layers are of commercial interest, such as the pearl oyster, Pinctada margaritifera, cultivated in French Polynesia to produce black pearls. It is well established that Mollusc shells are composite structures of organic and inorganic components (Hatchett, 1799; Grégoire et al., 1955; Beedham, 1958; Simkiss, 1965; Mutvei, 1969; Cuif et al., 1980; Berman et al., 1993; Kobayashi and Samata, 2006). Numerous studies are concerned with the organic matrix of the shell. Organic components are commonly obtained after a strong or mild decalcification process. They are said to consist of both a soluble and insoluble fraction. The main part of studies is dedicated to the soluble components, and among them, proteins (Grégoire et al., 1955; Grégoire, 1961; Krampitz et al., 1976; Samata et al., 1980, 2004; Weiner, 1983; Miyamoto et al., 2006). Despite the pioneering work of Wada (1980) sugars are usually neglected despite their role in biomineralization. The third component of the organic matrix of calcareous biominerals is lipids. To date, there is a paucity of information concerning the presence

  16. THE MEDICALLY IMPORTANT MOLLUSCS OF INDONESIA

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    Machfudz Djajasasmita

    2012-09-01

    Full Text Available At present in Indonesia 32 species of non-marine molluscs which belong to IS families have been known to be potentially of medicalor veterinary importance, since they are suspected to be capable in transmitting human and animal diseases. The brackish water family Potamididae comprises of 1 species; whereas the freshwater snails are : Viviparidae (3 sp., Ampullariidae (3 sp., Bythiniidae (1 sp.. Pomatiopsidae (1 sp., Thiaridae (7 sp., Lymnaeidae(l sp. and Planorbidae (5 sp.; freshwater bivalve are: Corbiculidae (4 sp.; land snails are: Subulinidae (2 sp., Achatinidae (1 sp. and Bradybaenidae (1 sp.; land slug: Veronicelidae (2 sp. Philomycidae (1 sp. and Limacidae (1 sp.. All are common species which can be found in the vicinity of human habitation (ponds, rice-field, ditches, gardens etc. The parasitological studies on these molluscs are rather limited, only 9 species have been studied and confirmed to be the intermediate host of parasitic nematodes and nematodes; i.e. Oncomelania hupensis lindoensis, the intermediate host of the blood fluke Schistosoma japonica in Central Sulawesi: Pila suctata, Achatina fulica and Laevicaulis alte from several places in Sumatra, Java, Sulawesi and Flores have been found to be harbouring the larvae of the nematode Angiostrongylus cantonensis, the causative agent of eosinophilic meningoencephalitis; Bellamy a rudipelis, Gyraulus sarasinorum and Corbicula lindoensis were recorded as the intermediate host of the intestinal fluke Echinostoma lindoensis in Central Sulawesi; Lymnaea rubiginosa plays an important role in the life-cycle of the cattle liver fluke Fasciola gigantica and F.hepatica, which may reduce the national meat production; and Digoniostoma truncatum from Bali has been recorded naturally infected with radiae and cercariae of Paramphistoma sp., the causative agent of the fatal paramphistomiasis of cattle. Gyraulus convexiusculus is considered to be the most likely first intermediate host of

  17. Molluscs for Sale: Assessment of Freshwater Gastropods and Bivalves in the Ornamental Pet Trade.

    Science.gov (United States)

    Ng, Ting Hui; Tan, Siong Kiat; Wong, Wing Hing; Meier, Rudolf; Chan, Sow-Yan; Tan, Heok Hui; Yeo, Darren C J

    2016-01-01

    The ornamental pet trade is often considered a key culprit for conservation problems such as the introduction of invasive species (including infectious diseases) and overharvesting of rare species. Here, we present the first assessment of the biodiversity of freshwater molluscs in the ornamental pet trade in Singapore, one of the most important global hubs of the ornamental aquarium trade, and discuss associated conservation concerns. We recorded freshwater molluscs from ornamental pet shops and major exporters including non-ornamental species (e.g., hitchhikers, molluscs sold as fish feed). We recorded an unexpectedly high diversity-59 species-of freshwater bivalves and gastropods, with the majority (38 species or 64%) being from the Oriental region. In addition to morphological examination, we sequenced the DNA barcode region of mitochondrial CO1 and 16S genes to provide molecular data for the confirmation of the identification and for future re-identification. DNA barcodes were obtained for 50 species, and all but four were separated by > 3% uncorrected pairwise distances. The trade has been considered a main introduction pathway for non-native species to Singapore, and we found that out of 15 species in the trade as well as in the wild in Singapore, 12 are either introduced or of unknown origin, representing almost half of the known non-native freshwater molluscs in Singapore. Particularly prevalent are non-ornamental species: six hitchhikers on aquarium plants and six species sold as fish feed. We found that a quarter of the trade species have a history of introduction, which includes 11 known or potentially invasive species. We conclude that potential overharvesting is difficult to assess because only half of the trade species have been treated by IUCN. Of these, 21 species are of Least Concern and three are Data Deficient. Our checklist, with accompanying DNA barcodes, images, and museum vouchers, provides an important reference library for future monitoring

  18. Marine 14C reservoir ages for 19th century whales and molluscs from the North Atlantic

    Science.gov (United States)

    Mangerud, Jan; Bondevik, Stein; Gulliksen, Steinar; Karin Hufthammer, Anne; Høisæter, Tore

    2006-12-01

    In order to compare radiocarbon dates on marine and terrestrial samples the former have to be corrected for a reservoir age. We present reservoir ages from dating 21 whales collected 1860-1901 and recalculating dates of 23 molluscs collected 1857-1926. Most of the whales were caught along the coast of Norway, but one is from France and one from Iceland. We assume the former mainly lived in the North and equatorial Atlantic and in the Norwegian Sea. Whales feed only on pelagic organisms and will provide the reservoir age for the open ocean surface water. However, they travel long distances and will integrate the reservoir ages of the different water masses along their way. Molluscs (dated from Norway, Spitsbergen and Arctic Canada) are stationary and monitor the sea water passing their dwelling site, but some also take up carbon from particulate food or sediment pore water. Coastal water also often contains some continental carbon. We present two different views on how to analyze and interpret the data. Mangerud recommends to use reservoir ages based on a combination of the whale and mollusc dates, i.e. 380±30 and 360±30 yr relative to Intcal04 and British oak, respectively, and a Δ R value of 20±30 for the surface water in the N-Atlantic and Norwegian Sea. Bondevik and Gulliksen maintain that the reservoir age—and Δ R—along the Norwegian coast is latitude dependant, with Δ R-values increasing from -3±22 in the South to 105±24 at Spitsbergen. Whales, reflecting North Atlantic open ocean surface water have lower Δ R (7±11) than most molluscs.

  19. [NADPH-diaphorase activity in digestive system of gastropod molluscs Achatina fulica and Littorina littorea].

    Science.gov (United States)

    Zaĭtseva, O V; Kuznetsova, T V; Markosova, T G

    2009-01-01

    Localization and peculiarities of NO-ergic elements were studied for he first time throughout the entire length of digestive tract of the marine gastropod mollusc Achatina fulica (Prosobranchia) and the terrestrial molusc Littorina littorea (Pulmonata) by using histochemical method of detection of NADPH-diaphorase (NADPHd). NO-ergic cells and fibers were revealed in all parts of the mollusc digestive tract beginning from pharynx. An intensive NADPHd activity was found in many intraepithelial cells of the open type and in their processes in intra- and subepithelial nerve plexuses, single subepithelial neurons, granular connective tissue cells, and numerous nerve fibers among muscle elements of he digestive tract wall as well as in nerves innervating the tract. NADPHd was also present in receptor cells of he oral area and in the central A. fulica ganglia participating in innervation of the digestive tract. The digestive tract NO-ergic system ofA. fulica has a more complex organization that that of L. littorea. In the A. fulica pharynx, stomach, and midgut, directly beneath epithelium, there is revealed a complex system of glomerular structures formed by thin NADPHd-positive nerve fibers coming from the side of epithelium. More superficially under the main groups of muscle elements, small agglomerations of NADPHd-positive neurons are seen, which could be considered as primitive, non-formed microganglia. Peculiarities of distribution and a possible functional role of NO-ergic elements in the digestive tract of molluscs are discussed as compared with other invertebrate and vertebrate animals.

  20. The Mediterranean stony coral Cladocora caespitosa (Linnaeus, 1767) as habitat provider for molluscs: colony size effect

    Science.gov (United States)

    Pitacco, Valentina; Crocetta, Fabio; Orlando-Bonaca, Martina; Mavrič, Borut; Lipej, Lovrenc

    2017-11-01

    The stony coral Cladocora caespitosa (Linnaeus, 1767) is an important Mediterranean habitat builder, whose survival is now being threatened by human activities and possibly natural events such as mass mortality and bleaching. We characterized the mollusc assemblage associated with colonies in the Gulf of Trieste (northern Adriatic Sea) and then tested whether the number of mollusc species increases in relation with colony size, following a Species-Area Relationship (SAR) model. At least 62 taxa were found in association with coral colonies, with bivalves constituting the dominant group. More than half of the 3034 specimens encountered were juveniles. Mollusc taxa richness increased with increasing C. caespitosa colony size according to the power-function model, whilst the analyses of trophic and functional groups supports the hypothesis of at least two factors underlying SAR (area per se and habitat diversity). Our results confirmed the importance of C. caespitosa for benthic communities, indicating that larger colonies support higher biodiversity, and suggesting that C. caespitosa is the most important habit builder among Mediterranean cnidarians, having also an influential function as a natural nursery ground. These results underline the necessity of new investigations aimed at filling gaps in our knowledge and planning new measures to protect the species.

  1. Conservation thinning in secondary forest: negative but mild effect on land molluscs in closed-canopy mixed oak forest in Sweden.

    Directory of Open Access Journals (Sweden)

    Birte Rancka

    Full Text Available Secondary succession is changing the character of many temperate forests and often leads to closed-canopy stands. In such forests set aside for conservation, habitat management alternatives need to be tested experimentally, but this is rarely done. The Swedish Oak Project compares two often debated alternatives: minimal intervention and non-traditional active management (conservation thinning on plots of each type replicated at 25 sites. We study responses of several taxa, and here report results for land molluscs. They are considered to be sensitive to more open, drier forest and we predicted a negative effect of the thinning (26% reduction of the basal area; mean value for 25 experimental forests. We sampled molluscs in the litter in ten 20 x 25 cm subplots, and by standardised visual search, in each plot. In total, we recorded 53 species of snails and slugs (24 369 individuals and the mean species richness in plots was 17. Two seasons after thinning, mean (± SE species richness had decreased by 1.4 (± 0.9 species in thinning plots, but increased by 0.7 (± 1.0 species in minimal intervention plots, a significant but small change with considerable variation among sites. In matched comparisons with minimal intervention, thinning reduced the overall abundance of molluscs. Most species responded negatively to thinning - but only five of the 53 species were significantly affected, and reproduction seemed to be negatively affected in only one species. An ordination analysis did not reveal any particular change in the species community due to thinning. Thus, the negative effect of conservation thinning on land molluscs was apparently mild - one reason was that many trees, shrubs and other forest structures remained after the treatment. Conservation thinning may be recommended, since other taxa are favoured, but minimal intervention is also a useful form of management for molluscs and saproxylic taxa.

  2. A biomonitoring study: trace metals in algae and molluscs from Tyrrhenian coastal areas

    International Nuclear Information System (INIS)

    Conti, M.E.; Cecchetti, Gaetano

    2003-01-01

    Marine organisms were evaluated as possible biomonitors of heavy metal contamination in marine coastal areas. Concentrations of Cd, Cr, Cu, Pb, and Zn were measured in the green algae Ulva lactuca L., the brown algae Padina pavonica (L.) Thivy, the bivalve mollusc Mytilus galloprovincialis Lamarck, and the two gastropod molluscs Monodonta turbinata Born and Patella cerulea L. collected at six coastal stations in the area of the Gulf of Gaeta (Tyrrhenian Sea, central Italy). The coastal area of the Regional Park of Gianola and Monte di Scauri (a 'Protected Sea Park' area) was chosen as a control site. Seawater samples were also collected in each site to assess soluble and total metal concentrations and to gain additional information on both the environmental conditions of the area and possible bioaccumulation patterns. Metal concentrations detected in algae and molluscs did not show significant differences among all stations studied. Moreover, statistical analyses (ANOVA, multiple comparison tests, cluster analysis) showed that the Sea Park station was not significantly different from the others. The hypothesis that the Protected Sea Park would be cleaner than the others must therefore be reconsidered. Data from this study were also compared with those previously obtained from uncontaminated sites in the Sicilian Sea, Italy. The results show clearly differences between these two marine ecosystems. The species examined showed great accumulations of metals, with concentration factors (CFs) higher than 10,000 with respect to the concentrations (soluble fractions) in marine waters. Metal concentrations recorded in this area may be used for background levels for intraspecific comparison within the Tyrrhenian area, a body of water about which information is still very scarce

  3. First record of molluscs naturally infected with Angiostrongylus cantonensis (Chen, 1935 (Nematoda: Metastrongylidae in Brazil

    Directory of Open Access Journals (Sweden)

    Roberta Lima Caldeira

    2007-11-01

    Full Text Available Seeking the identification of Angiostrongylus cantonensis as a potential etiological agent of three clinical cases of eosinophilic meningitis, mollusc specimens were collected in the state of Espírito Santo, Brazil. The snails were identified as Sarasinula marginata (45 specimens, Subulina octona (157, Achatina fulica (45 and Bradybaena similaris (23. Larvae obtained were submitted to polymerase chain reaction and restriction fragment length polymorphism diagnosis. Their genetic profile were corresponded to A. cantonensis. Rattus norvegicus experimentally infected with third-stage larvae, developed menigoencephalitis, and parasites became sexually mature in the lungs. Additionally, larvae obtained from A. fulica snails, from São Vicente, state of São Paulo, also showed genetic profiles of this nematode. This is the first record of Brazilian molluscs infected with this nematode species.

  4. Assessment of Heavy Metals in Bivalves Molluscs of Apulian Region: a 3-years control activity of a EU Laboratory

    Directory of Open Access Journals (Sweden)

    Miedico O.

    2013-04-01

    Full Text Available The bivalve molluscs represent an important matrix to be studied for several reasons. Their nutritional properties make them valuable to the consumers, so that their consumption and commercial value has risen worldwide. Simultaneously, their significant water-filtering capability and their persistence in the same place make them good bio-indicators of marine ecosystems. The presence of the heavy metal contaminants, as Cd, Pb and Hg, was investigated in bivalve molluscs such as mussels (Mytilus galloprovincialis, clams (Venus gallina and oysters (Ostrea edulis. In the present study, a survey was carried out on 334 samples addressed to the Istituto Zooprofilattico Sperimentale – Puglia e Basilicata, Foggia (ITALY between 2009-2011, and collected by official authorities along the coasts of Apulia Region. The conformity of heavy metal content in bivalve molluscs was verified, in according to EC Reg. 1881/2006. The compliance was found for the total amount of samples. The obtained data on heavy metals concentration in bivalve molluscs were compared with data found in monitoring studies on the incidence of heavy metals in 1981 in North-Western Mediterranean Sea, in 2003 in Tyrrhenian Sea and in 2010 in Pacific Ocean (Chile, reported in literature. The information obtained from this work offer an essential database, not only for the authorities involved in food control, but also for the official institutions responsible of a constant control of the marine ecosystem pollution.

  5. Coral and mollusc resistance to ocean acidification adversely affected by warming

    Science.gov (United States)

    Rodolfo-Metalpa, R.; Houlbrèque, F.; Tambutté, É.; Boisson, F.; Baggini, C.; Patti, F. P.; Jeffree, R.; Fine, M.; Foggo, A.; Gattuso, J.-P.; Hall-Spencer, J. M.

    2011-09-01

    Increasing atmospheric carbon dioxide (CO2) concentrations are expectedto decrease surface ocean pH by 0.3-0.5 units by 2100 (refs , ), lowering the carbonate ion concentration of surfacewaters. This rapid acidification is predicted to dramatically decrease calcification in many marine organisms. Reduced skeletal growth under increased CO2 levels has already been shown for corals, molluscs and many other marine organisms. The impact of acidification on the ability of individual species to calcify has remained elusive, however, as measuring net calcification fails to disentangle the relative contributions of gross calcification and dissolution rates on growth. Here, we show that corals and molluscs transplanted along gradients of carbonate saturation state at Mediterranean CO2 vents are able to calcify and grow at even faster than normal rates when exposed to the high CO2 levels projected for the next 300 years. Calcifiers remain at risk, however, owing to the dissolution of exposed shells and skeletons that occurs as pH levels fall. Our results show that tissues and external organic layers play a major role in protecting shells and skeletons from corrosive sea water, limiting dissolution and allowing organisms to calcify. Our combined field and laboratory results demonstrate that the adverse effects of global warming are exacerbated when high temperatures coincide with acidification.

  6. FEATURES OF THE GEOGRAPHICAL DISTRIBUTION OF TERRESTRIAL MOLLUSCS IN THE CAUCASUS

    Directory of Open Access Journals (Sweden)

    M. Z. Magomedova

    2015-01-01

    Full Text Available Aim. High population, high proliferation rates, a large species diversity, low mobility and small ability to overcome geographic barriers, ease of collecting material and sensitive response to changes in the external environment makes this group a convenient object of biogeographic and ecological research. Methods. The inventory of Caucasian ground malacofauna made it possible to make a complete list of species; their characteristics were determined by the geographical distribution of major natural regions of the Caucasus. Results. The comparative analysis of the geographical distribution of terrestrial molluscs on key areas of the Caucasus showed that among the 352 species belonging to 140 genera of 36 families, most richly represented Western Caucasus, which accounts for 51% or 181 species from 80 genera of 20 families, while the share of Armenian, Eastern and Central Caucasus accounts for 35-37%. Talysh, in turn, is characterized by the presence of only 11% of the species composition of the Caucasian land mollusc. Caucasus limited in distribution among the analyzed species is 72% or 255 species belonging to 104 genera of 24 families. Conclusion. The results prove the species diversity of the different regions of theCaucasus and could serve as the basis to reconsider the possible ways of formation of fauna of the region discussed. 

  7. Angiostrongylus cantonensis (Nematode: Metastrongyloidea in molluscs from harbour areas in Brazil

    Directory of Open Access Journals (Sweden)

    Omar dos Santos Carvalho

    2012-09-01

    Full Text Available Angiostrongylus cantonensis is the most common aetiological agent of human eosinophilic meningoencephalitis. Following a report indicating the presence of this parasite in Brazil in 2007, the present study was undertaken to investigate the presence of A. cantonensis in the surrounding Brazilian port areas. In total, 30 ports were investigated and the following molluscs were identified: Achatina fulica, Belocaulus sp., Bradybaena similaris sp., Cyclodontina sp., Helix sp., Leptinaria sp., Melampus sp., Melanoides tuberculata, Phyllocaulis sp., Pomacea sp., Pseudoxychona sp., Rhinus sp., Sarasinula marginata, Streptaxis sp., Subulina octona, Succinea sp., Tomigerus sp., Wayampia sp. and specimens belonging to Limacidae and Orthalicinae. Digestion and sedimentation processes were performed and the sediments were examined. DNA was extracted from the obtained larvae and the internal transcribed spacer region 2 was analysed by polymerase chain reaction-restriction fragment length polymorphism after digestion with the endonuclease ClaI. Of the 30 ports investigated in this study, 11 contained molluscs infected with A. cantonensis larvae. The set of infected species consisted of S. octona, S. marginata, A. fulica and B. similaris. A total of 36.6% of the investigated ports were positive for A. cantonensis, indicating a wide distribution of this worm. It remains uncertain when and how A. cantonensis was introduced into South America.

  8. Coral and mollusc resistance to ocean acidification adversely affected by warming

    OpenAIRE

    Rodolfo-Metalpa, R; Houlbrèque, F; Tambutté, E; Boisson, F; Baggini, C; Patti, FP; Jeffree, R; Fine, M; Foggo, A; Gattuso, JP; Hall-Spencer, JM

    2011-01-01

    Increasing atmospheric carbon dioxide (CO 2) concentrations are expectedto decrease surface ocean pH by 0.3-0.5 units by 2100 (refs,), lowering the carbonate ion concentration of surfacewaters. This rapid acidification is predicted to dramatically decrease calcification in many marine organisms. Reduced skeletal growth under increased CO 2 levels has already been shown for corals, molluscs and many other marine organisms. The impact of acidification on the ability of individual species to cal...

  9. Application of photostimulated luminescence (PSL) to detect irradiated molluscs

    International Nuclear Information System (INIS)

    Marchesani, G.; Chiaravalle, A.E.; Chiesa, L.M.

    2011-01-01

    Complete text of publication follows. In contrast to thermally processed foods, irradiation is a cold treatment both to reduce microbiological contamination and to increase the shelf-life of raw seafood. According to the list of States' authorizations molluscs can be irradiated in a range of 0.5 / 3 kGy only in authorized countries (e.g. UK, Belgium and Czech Republic). Therefore the aim of this study is to identify, at different dose levels (0.5, 1, 1.5, 2, 3 kGy), irradiated oysters, clams and mussels using luminescence materials from different sites (shells and pulps) and to determine sample sensitivity for previous screening result confirmation. A total number of 10 samples for each species were analyzed by both procedures: screening and calibrated PSL. Samples were irradiated using a low energy X-ray irradiator (RS-2400, Radsource Inc.) with the following operational settings: 150 kV and 45 mA. Whole pulps were simply dispensed into a clean Petri-dish whereas shells powder required to be fixed as a thick layer with silicone grease. Results obtained showed that screening analysis can be used to identify correctly all irradiated and non irradiated samples. Particularly untreated sample exhibited a sensitivity index from 2 to 4 order of magnitude greater than the exposed sample one, while for exposed specimen calibrated PSL signals, after re-irradiation at defined dose, were of the same order of the first measurement (initial PSL counts). In conclusion mineral debris contaminating pulps and biocarbonates from shells can be considered reliable radioinduced markers and PSL techniques can be easily applied for rapid and simple analysis to identify irradiated molluscs in official controls.

  10. Molluscs associated with the macroalgae of the genus Gracilaria (Rhodophyta): importance of algal fronds as microhabitat in a hypersaline mangrove in Northeastern Brazil.

    Science.gov (United States)

    Queiroz, R N M; Dias, T L P

    2014-08-01

    The fronds of marine macroalgae play an important role in coastal ecosystems because the algae banks are utilized as a microhabitat by different taxa, including molluscs, one of the most abundant and diverse animals of marine ecosystems. In this study, we characterized the malacofauna associated with the macroalgae Gracilaria domingensis (Kützing) Sonder ex Dickie 1874 and Gracilaria cuneata Areschoug 1854 of a hypersaline mangrove on the northern coast of the state of Rio Grande do Norte, Northeastern Brazil. The first alga dominates in the rainy season and it is substituted by second one in the dry period. A total of 1,490 molluscs were surveyed, representing 56 species in 29 families: 1,081 were associated with G. domingensis and 409 with G. cuneata, the latter showing the greater diversity (H'=1.25). Columbellidae, Neritidae, Pyramidellidae and Cerithiidae were among the most representative families in the number of species and individuals. The micromolluscs were dominant in the algal microhabitat, constituting 74.63% of the malacofauna recorded. The columbellid Parvanachis obesa (C. B. Adams, 1845) was the dominant species followed by the neritid Neritina virginea (Linnaeus, 1758) in both algae. In spite of the annual alternated succession of the algae species, at least 15 mollusc species are common for these algae. Furthermore, juveniles of P. obesa were recorded in both seasons, indicating a continuous reproduction. Possible reasons for difference in abundance, diversity and dominance of molluscs living on these algae are discussed. Both species of substrate-algae represent an important microhabitat for refuge, feeding and the reproduction of small-sized mollusc species during rainy and dry seasons.

  11. Molluscs associated with the macroalgae of the genus Gracilaria (Rhodophyta: importance of algal fronds as microhabitat in a hypersaline mangrove in Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    RNM Queiroz

    Full Text Available The fronds of marine macroalgae play an important role in coastal ecosystems because the algae banks are utilized as a microhabitat by different taxa, including molluscs, one of the most abundant and diverse animals of marine ecosystems. In this study, we characterized the malacofauna associated with the macroalgae Gracilaria domingensis (Kützing Sonder ex Dickie 1874 and Gracilaria cuneata Areschoug 1854 of a hypersaline mangrove on the northern coast of the state of Rio Grande do Norte, Northeastern Brazil. The first alga dominates in the rainy season and it is substituted by second one in the dry period. A total of 1,490 molluscs were surveyed, representing 56 species in 29 families: 1,081 were associated with G. domingensis and 409 with G. cuneata, the latter showing the greater diversity (H′=1.25. Columbellidae, Neritidae, Pyramidellidae and Cerithiidae were among the most representative families in the number of species and individuals. The micromolluscs were dominant in the algal microhabitat, constituting 74.63% of the malacofauna recorded. The columbellid Parvanachis obesa(C. B. Adams, 1845 was the dominant species followed by the neritid Neritina virginea (Linnaeus, 1758 in both algae. In spite of the annual alternated succession of the algae species, at least 15 mollusc species are common for these algae. Furthermore, juveniles of P. obesa were recorded in both seasons, indicating a continuous reproduction. Possible reasons for difference in abundance, diversity and dominance of molluscs living on these algae are discussed. Both species of substrate-algae represent an important microhabitat for refuge, feeding and the reproduction of small-sized mollusc species during rainy and dry seasons.

  12. Evaluation of the effect of temperature, pH, and bioproduction on Hg concentration in sediments, water, molluscs and algae of the delta of the Ebro river.

    Science.gov (United States)

    Schuhmacher, M; Domingo, J L; Llobet, J M; Corbella, J

    1993-01-01

    The effects of temperature, pH, and bioproduction on mercury levels in sediments, water, molluscs and algae from the delta of the Ebro river (NE Spain) were determined in this study. Mercury concentrations were measured in a cold-vapor atomic absorption spectrophotometer. The ranges of mercury concentrations were the following: sediments, 0.014-0.185 microgram g-1; water, 0.001-0.018 microgram g-1; molluscs, 0.118-0.861 microgram g-1; and algae 0.008-0.026 microgram g-1. Although not statistically significant, a decrease in the pH of the water corresponded with a diminution in the content of mercury in sediments and molluscs, while the mercury levels in water and algae were lower in the areas with high levels of bioproduction. The concentrations of mercury in water significantly decreased with temperature. However, the differences with temperature of the mercury concentrations in sediments did not reach the level of significance. Consequently, water would not be an adequate indicator to determine the levels of mercury contamination, although both sediments and molluscs can be used for this purpose.

  13. Rodriguesic acids, modified diketopiperazines from the gastropod mollusc Pleurobranchus areolatus

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Fabio R.; Santos, Mario F.C.; Berlinck, Roberto G.S., E-mail: rgsberlinck@iqsc.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Quimica; Williams, David E.; Andersen, Raymond J. [Departments of Chemistry and Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver (Canada); Padula, Vinicius [SNSB-Zoologische Staatssammlung München, München, Germany and Department Biology II and GeoBio-Center, Ludwig-Maximilians-Universität München, (Germany); Ferreira, Antonio G. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica

    2014-04-15

    In the present investigation, two specimens of the nudipleuran mollusc Pleurobranchus areolatus have shown to accumulate oxidized rodriguesin A derivatives. Rodriguesic acid presents a carboxylic acid replacing the terminal methyl group of the alkyl chain of rodriguesin A. A hydroxamate group was also present on the diketopiperazine moiety of a rodriguesic acid derivative. The structures of both rodriguesic acid and of rodriguesic acid hydroxamate have been established by analysis of spectroscopic data, including their absolute configuration. Two methyl esters of the rodriguesic acids have been isolated as major compounds, but were considered to be isolation artifacts. (author)

  14. Rodriguesic acids, modified diketopiperazines from the gastropod mollusc Pleurobranchus areolatus

    International Nuclear Information System (INIS)

    Pereira, Fabio R.; Santos, Mario F.C.; Berlinck, Roberto G.S.; Padula, Vinicius; Ferreira, Antonio G.

    2014-01-01

    In the present investigation, two specimens of the nudipleuran mollusc Pleurobranchus areolatus have shown to accumulate oxidized rodriguesin A derivatives. Rodriguesic acid presents a carboxylic acid replacing the terminal methyl group of the alkyl chain of rodriguesin A. A hydroxamate group was also present on the diketopiperazine moiety of a rodriguesic acid derivative. The structures of both rodriguesic acid and of rodriguesic acid hydroxamate have been established by analysis of spectroscopic data, including their absolute configuration. Two methyl esters of the rodriguesic acids have been isolated as major compounds, but were considered to be isolation artifacts. (author)

  15. Postglacial floodings of the Marmara Sea: molluscs and sediments tell the story

    Science.gov (United States)

    Büyükmeriç, Yeşim

    2016-08-01

    The early Holocene marine flooding of the Black Sea has been the subject of intense scientific debate since the "Noah's Flood" hypothesis was proposed in the late 1990s. The chronology of the flooding is not straightforward because the connection between the Black Sea and the Mediterranean Sea involves the intermediate Marmara Sea Basin via two sills (Dardanelles and Bosphorus). This study explores the chronology of late Pleistocene-Holocene flooding by examining sedimentary facies and molluscs from 24 gravity cores spanning shelf to slope settings in the southern Marmara Sea Basin. A late Pleistocene Ponto-Caspian (Neoeuxinian) mollusc association is found in 12 of the cores, comprising 14 mollusc species and dominated by brackish (oligohaline-lower mesohaline) endemic taxa (dreissenids, hydrobiids). The Neoeuxinian association is replaced by a Turritella- Corbula association at the onset of the Holocene. The latter is dominated by marine species, several of which are known to thrive under dysoxic conditions in muddy bottoms. This association is common in early Holocene intervals as well as sapropel intervals in younger Holocene strata. It is an indicator of low-salinity outflows from the Black Sea into the Marmara Sea that drive stratification. A marine Mediterranean association (87 species) represents both soft bottom and hard substrate faunas that lived in well-ventilated conditions and upper mesohaline-polyhaline salinities (ca. 25 psu). Shallower areas were occupied by hard substrate taxa and phytopdetritic communities, whereas deeper areas had soft bottom faunas. The middle shelf part of the northern Gemlik Gulf has intervals with irregular and discontinuous sedimentary structures admixed with worn Neoeuxinian and euryhaline Mediterranean faunas. These intervals represent reworking events (slumping) likely related to seismic activity rooted in the North Anatolian Fault system. The core data and faunas indicate an oscillating postglacial sea-level rise and

  16. Voyaging around nacre with the X-ray shuttle: From bio-mineralisation to prosthetics via mollusc phylogeny

    International Nuclear Information System (INIS)

    Chateigner, D.; Ouhenia, S.; Krauss, C.; Hedegaard, C.; Gil, O.; Morales, M.; Lutterotti, L.; Rousseau, M.; Lopez, E.

    2010-01-01

    Research highlights: → Nacre could be a non ancestral form of calcium carbonate in molluscs. → Texture terms as useful links to ancestors in classification. → X-ray diffraction useful for biomineralisation, phylogeny, cladistic and implantology. → Farming conditions do not influence much shell growth. → Electrodeposition of aragonite as future technique for implant coating. - Abstract: Strong textures of mollusc shell layers are utilised to provide phylogenetic information. Aragonitic and calcitic layers are the targets here, inside which nacre layers, but not only, play a specific role. At the light of the texture patterns and a parcimonious approach, nacre appears not as an ancestral form of calcium carbonate in mollusc layers. Also, from texture terms we can propose some links to ancestral fossilised species. The aragonite unit-cell distortions due to macromolecule complex insertions in the microstructures are measured on raw specimens for several aragonite layers of gastropods and bivalves. The textural information is used to provide precise structural determination of the biogenic aragonite. Such information might provide useful lights on the biomineralisation processes in the future, in cladistic approaches. Farming conditions are shown not to influence much shell textures of Helix aspersa aspersa. Closely related species exhibit globally close textures, among which three are good candidates for bone neogeneration and which textures are identical. Electrodeposition of aragonite, with inclusion of molecular extract from shell species, results in nacre-like layers exhibiting structural distortions similar to known inductive layers. X-ray diffraction experiments are shown to provide invaluable insights in testing biomineralisation and phylogenetic hypotheses.

  17. Isolation of living Algae growing in the shells of Molluscs and Barnacles with EDTA (ethylenediaminetetraacetic acid)

    NARCIS (Netherlands)

    Prud’homme van Reine, W.F.; Hoek, van den C.

    1966-01-01

    Several decalcifying mixtures or aqueous solutions of inorganic or organic acids are generally used for releasing algae growing in the shells of molluscs and barnacles, for instance dilute hydrochloric, nitric, citric, or acetic acid (4), a mixture of nitric acid, chromic acid and alcolhol (1),

  18. First records of freshwater molluscs from the ecological reserve El Edén, Quintana Roo, México Primeros registros de moluscos dulceacuícolas de la Reserva Ecológica El Edén, Quintana Roo, México

    Directory of Open Access Journals (Sweden)

    Roberto Cózatl-Manzano

    2007-12-01

    Full Text Available The diversity of the freshwater molluscs at El Edén was unknown. This is the first treatment of them, allowing us to compare spatial and temporal species distribution. Eleven species of freshwater molluscs were found in 2 surveys carried in March (dry season and September (rainy season 1998 at the reserve El Edén. A total of 266 individuals were collected; 8 pulmonates, Mayabina spiculata, Mexinauta impluviatus, Physa sp., Biomphalaria havanensis, Drepanotrema lucidum, Drepanotrema kermatoides, Planorbella (Pierosoma trivolvis, and Planorbula armigera; 2 prosobranchs, Pyrgophorus sp. and Pomacea flagellata; and one bivalve, Musculium transversum. Pulmonata dominate over Prosobranchia species in diversity. No significant differences were observed in diversity between dry and rainy seasons. However, species abundance recorded in both seasons was very low, probably due to a combination of inadequate food resources and disadvantageous climate (periodic conditions of drought and flooding. Further studies using a combination of different sampling methods and more frequent samplings are needed to confirm or identify these factors. We suggest that future studies should focus on cultivation of species with economic potential such as the apple snail Pomacea flagellata.La diversidad de moluscos dulceacuícolas de la Reserva Ecológica El Edén se desconocía; este estudio constituye su primer registro. Asimismo, esta investigación permite comparar la distribución espacial y temporal de las especies registradas. Las recolectas se efectuaron en marzo (temporada de sequía y septiembre (lluvia de 1998. Se registran 11 especies (266 individuos en total, 8 pulmonados: Mayabina spiculata, Mexinauta impluviatus, Physa sp., Biomphalaria havanensis, Drepanotrema lucidum, Drepanotrema kermatoides, Planorbella (Pierosoma trivolvis y Planorbula armigera; dos prosobranquios: Pyrgophorus sp. y Pomacea flagellata, y un bivalvo: Musculium transversum. Los pulmonados

  19. An investigation of green iridescence on the mollusc Patella granatina

    Energy Technology Data Exchange (ETDEWEB)

    Brink, D J; Berg, N G van der [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa)

    2005-01-21

    In this paper we investigate the relatively rare phenomenon of iridescence on the outer surface of seashells (not the well known pearly inner surfaces). Using reflection spectroscopy and scanning electron microscopy we show that rows of iridescent green spots on the mollusc Patella granatina are caused by a thin-film stack buried about 100 {mu}m below the rough outer surface of the shell. The high-density layers in the stack seem to be made of crystalline aragonite, but according to Raman spectroscopy and ellipsometry measurements the low-density layers as well as the bulk of the shell wall are a mixture of porous aragonite and organic materials such as carotenoids.

  20. Traditional utilization and biochemical composition of six mollusc shells in Nigeria

    Directory of Open Access Journals (Sweden)

    Ademolu Kehinde O.

    2015-06-01

    Full Text Available The shells of molluscs protect them from physical damage, predators and dehydration. We studied various local uses of shells and their biochemical properties in Abeokuta, Nigeria. A standard structured questionnaire about use was applied to 100 snail and herb sellers and shells from 120 adult individuals of Archachatina marginata, Achatina achatina, Achatina fulica, Littorina littorea, Meretrix lusoria and Merceneria mercenaria were evaluated for their mineral components (Ca2+, Fe2+, Mg2+, Na+, Zn+, P+, K+ and proximate composition (crude protein, ash, fibre, crude fat and carbohydrate using standard methods. Properties against fungi and bacteria isolates were also tested. These shells are used for bleaching, brushing, abrasion and others. The weight of the shells varied from 0.5g (L. littorea to 25.00g (A. marginata and thickness from 0.46mm in M .lusoria to 5.35mm in M. mercenaria. We found no inhibitory effect against fungi and bacterial isolates. The molluscs are high in carbohydrates (83.54-92.76g/100g and low in protein (0.16-0.38g/100g. The fat content ranged between 0.42g/100g and 0.82g/100g, and ash between 2.14g/100g and 9.45g/100g. Ca2+ was the most abundant (10.25-96.35mg/g while K+ was the least abundant (0.3-0.7mg/g (p<0.05. Active ingredients of these shells can be used in the feed and construction industries.

  1. Mollusc and brachiopod skeletal hardparts: Problematic archives of past seawater properties (Invited)

    Science.gov (United States)

    Immenhauser, A.; Schone, B. R.; Hoffmann, R.; Niedermayr, A.

    2013-12-01

    Biomineralized exo- or endoskeletons of fossil marine invertebrates are widespread and diverse components of the Phanerozoic rock record of Earth's past and present oceans. Exoskeletons serve as protection against environmental pressure or predators, whilst endoskeletons may act as support or serves as an attachment for muscles and ligaments and hence as a mechanism for transmitting muscular forces. Biogenic hardparts represent sophisticated products resulting from the hierarchical interaction of inorganic minerals (95%) and macromolecular organic matrix, forming commonly less than 5%. The significance of biogenic carbonate archives lies in the time-resolved growth-increments and their respective multi-proxy geochemical signatures that have been widely used to assess past oceanic seawater properties. We here compile and review published work dealing with crystallization pathways of skeletal hardparts secreted by molluscs (i.e., bivalves and cephalopods) as well as brachiopods as widely used archives of ancient neritic epeiric settings. Bivalves and cephalopods (e.g., extinct ammonoids and belemnites and extant Sepia, Nautilus and Spirula) all form accretionary calcitic, aragonitic or vateritic skeletal hardparts. Despite the fact that molluscs and brachiopods form part of very different branches of the animal phylogenetic tree, their biomineralization strategies are surprisingly similar. Our main focus lies in a critical assessment of the complex pathways of ions and aquo-complexes from their source (seawater) to the final product (biomineral). We do this as an attempt to critically test the commonly held hypothesis that many fossil shell hardparts precipitated, under favourable conditions and pending subsequent diagenetic alteration, in equilibrium with seawater. Two main observations stand out: (1) the present knowledge on pathways and mechanisms (e.g., ion channel trans-membrane or endocytosis and vesicle transport, precursor mineralogies etc.) is surprisingly

  2. The clam (Chamelea gallina: evaluation of the effects of solids suspended in seawater on bivalve molluscs

    Directory of Open Access Journals (Sweden)

    Salvatora Angela Angioni

    2010-03-01

    Full Text Available The study was designed to evaluate the effects of solids in suspension in seawater on clams (Chamelea gallina. The aim was to investigate the possible correlation between the widespread deaths of clams in the coastal waters of the central and northern Adriatic in the last five years and increased concentrations of solids in suspension. The research involved conducting 96-hour tests on clams farmed in aquariums containing filtered seawater. The tests were preceded by a 7-day adaptation stage to allow the molluscs to acclimatise. During this period, the clams were fed on unicellular seaweed (Dunaliella tertiolecta. The molluscs were exposed to particles of solids in suspension consisting of pools of silica gel (SiO2 granules of various sizes, similar to those constituting silt, whose presence and suspension in the sea considerably increase after heavy rain and heavy seas. The study established that the number of deaths caused by solids suspended in seawater at the concentrations used in the tests was not statistically significant.

  3. Are the Traditional Medical Uses of Muricidae Molluscs Substantiated by Their Pharmacological Properties and Bioactive Compounds?

    Directory of Open Access Journals (Sweden)

    Kirsten Benkendorff

    2015-08-01

    Full Text Available Marine molluscs from the family Muricidae hold great potential for development as a source of therapeutically useful compounds. Traditionally known for the production of the ancient dye Tyrian purple, these molluscs also form the basis of some rare traditional medicines that have been used for thousands of years. Whilst these traditional and alternative medicines have not been chemically analysed or tested for efficacy in controlled clinical trials, a significant amount of independent research has documented the biological activity of extracts and compounds from these snails. In particular, Muricidae produce a suite of brominated indoles with anti-inflammatory, anti-cancer and steroidogenic activity, as well as choline esters with muscle-relaxing and pain relieving properties. These compounds could explain some of the traditional uses in wound healing, stomach pain and menstrual problems. However, the principle source of bioactive compounds is from the hypobranchial gland, whilst the shell and operculum are the main source used in most traditional remedies. Thus further research is required to understand this discrepancy and to optimise a quality controlled natural medicine from Muricidae.

  4. The effect of submarine thermal springs of Doğanbey Cape (Seferihisar - İzmir on foraminifer, ostracod and mollusc assemblages

    Directory of Open Access Journals (Sweden)

    Engin MERİÇ

    2017-12-01

    Full Text Available The aim of this study was to fi gure out the effects of the submarine hot water springs located on the coast of Doğanbey Cape (north of Kuşadası Bay on various micro- and macrofaunal assemblages living around these springs. Young sediment samples were collected from different depths at 15 stations. The benthic foraminifer, ostracod and mollusc faunas were investigated. 35 genera and 61 species of benthic foraminifers, 16 genera and 20 species of ostracods and 14 genera and 15 species of molluscs were identifi ed. Typical Aeegan foraminifer fauna was found to be dominant. Besides, individuals with colored tests or abnormal morphology, as well as alien species, which are frequently observed on the Aegean coasts were also observed in the study area. The foraminifer, ostracod and mollusc species also constituted typical Aegean fauna. It is known that the ecological conditions experienced of the Amphistegina lobifera Larsen individuals in typical Aegean benthic foraminifer assemblage have an effect on the abundance distribution. Ideal conditions for Amphistegina lobifera Larsen was found to be 18.00-32.00 m depth range and 19-20oC temperatures. CTD conductivity values gradually increased near to the hot water spring but a decrease in the number of individuals were observed. Chemical analyzes in sediment samples were performed with X-Ray Fluorescence Analysis Spectrometer (WDXRF. Heavy metal ingredients (Cr, Mn, Co, Ni, Cu, Zn and Pb of the sediments were evaluated, concentrations were recorded as Cr>Ni>Mn in samples DB1-DB6 and also in DB15; Mn>Cr>Ni in DB8-DB11 and DB13-DB14; Cr>Mn>Ni in DB7 and in DB12. The radioactive elements U and Th were found to be high in DB9, DB10 and DB11. The chemical and radioactive properties of the sediments were observed to affect the tests of benthic foraminifers, where as no such effect was found on ostracod and mollusc tests.

  5. Měkkýši Národní přírodní rezervace Soos Molluscs (Mollusca of the Soos National Nature Reserve

    Directory of Open Access Journals (Sweden)

    Jitka Horáčková

    2012-12-01

    Full Text Available The Soos National Nature Reserve nearby Františkovy Lázně Town (Western Bohemia, Czech Republic is a spectacular peatbog site with the occurrence of fens on numerous mineral spring effluents, emanations of pure carbon dioxide in mofettes (i.e. false mud volcanoes, parts with saltwater wetlands, and diatomite mantel in its central part. These natural conditions affect general character of all habitats, vegetation and malacocoenoses in the reserve. Altogether, 31 mollusc species were found there, but only two of them are considered as near threatened (Pisidium obtusale and Vertigo substriata. The majority of recorded assemblage was composed of common and generalist mollusc species.

  6. New trends in important diseases affecting the culture of fish and molluscs in the ICES area 2002-2015

    DEFF Research Database (Denmark)

    Alfjorden, Anders; Areskog, Marlene; Bruno, David

    The ICES Working Group on Pathology and Diseases of Marine Organisms (WGPDMO) provides annual reviews of national reports on the disease status of wild and farmed fish and molluscs in the ICES area. In 2004, the group published a first report collating this information from 1998-2002. This second...

  7. Detection limits by EPR spectroscopy of cumulated doses ionizing radiations in molluscs shells

    International Nuclear Information System (INIS)

    Ostrowski, K.; Burlinska, G.; Dziedzic-Goclawska, A.; Stachowicz, W.; Michalik, J.; Sadlo, J.

    1997-01-01

    The exposure of waters to ionizing radiation from radionuclides stored in concrete containers or freed in nuclear accidents or underwater eruption might be difficult to be proved, when currents, rains, exchange of water displace sand soils or rocks in the bottom. Ionizing radiation evokes stable paramagnetic centers in the crystalline lattice of mineral components in bones as well as in exoskeletons of most molluscs, which are detected by the EPR spectroscopy and could be used as an indicator of the exposure to the action of radiation during prolonged period of time. (authors)

  8. Sensitivity of Mediterranean bivalve mollusc aquaculture to climate change, ocean acidification, and other environmental pressures: findings from a producers’ survey

    NARCIS (Netherlands)

    Rodrigues, L.; van den Bergh, J.C.J.M.; Mass, F.; Theodorou, J.A.; Ziveri, P.; Gazeau, F.

    2015-01-01

    Human-induced climate change and ocean acidification are global environmental phenomena with a common driver: anthropogenic emissions of carbon dioxide. Both processes potentially threaten the Mediterranean bivalve mollusc aquaculture sector, which is economically relevant to several regions and

  9. On the safe of pesticides in controlling the terrestrial mollusc pests

    Directory of Open Access Journals (Sweden)

    A. Panigrahi

    1993-06-01

    Full Text Available The preferred food items of the slugs Laevicaulis alte and the snails Achatina fulica were used to prepare 'poison baits'by injecting the pesticides 'Rogor'and 'Nuvan'to kill these mollusc pests. The 'poison baits'prepared with Thrichosanthes dioica and Lycopersicum esculentum were accepted by 100% individuals of both the species irrespective of the pesticides used. In all cases the slug and the snail individuals died within a considerable length of time following consuption of the bait. The importance of using 'poison bait'lies not only with the sure success in killing the pests but also with the 'safe use'of toxic materials in order to avoid environmental hazards.

  10. The lunar-tide cycle viewed by crustacean and mollusc gatherers in the State of Paraíba, Northeast Brazil and their influence in collection attitudes

    Directory of Open Access Journals (Sweden)

    Alves Rômulo RN

    2006-01-01

    Full Text Available Abstract Traditional human communities have a wide knowledge of their environment. Collection of animals in estuarine and coastal areas are directly influenced by tidal cycles. The aim of this study is to evaluate the understanding of the tides associated with the lunar cycle held by people who gather crustaceans and molluscs in the State of Paraiba. The empirical knowledge of 20 crab gatherers and 30 mollusc gatherers was recorded through open interviews and structured questionnaires. The results showed that the gatherers have an accurate comprehension of tidal phenomenon based on their exploitation of natural resources, which perpetuates through generations.

  11. Tinjauan Keanekaragaman Moluska Air Tawar Di Beberapa Situ Di DAS Ciliwung - Cisadane [Study on the Freshwater Mollusc Diversity of the Small Lakes Along Ciliwung and Cisadane Rivers

    OpenAIRE

    Marwoto, Ristiyanti M; Isnaningsih, Nur R

    2014-01-01

    The freshwater molluscs (snails and bivalves) can be found in many type of water course either flowing or stagnant water. Some of them have survived living in bad condition such as polluted water. There are 199 situ (small lakes) in Jabodetabek (Jakarta, Bogor, Depok, Tangerang, Bekasi) have been reported but only 20 % were in good condition, even 12% have dissapeared that caused by silting up of the situ. The aim of the study was to evaluate the diversity of the molluscs as well as to know t...

  12. Responses of freshwater molluscs to environmental factors in Southern Brazil wetlands Respostas de moluscos límnicos a fatores ambientais em áreas úmidas do sul do Brasil

    Directory of Open Access Journals (Sweden)

    L. Maltchik

    2010-08-01

    Full Text Available Freshwater molluscs play an important role in aquatic ecosystems, providing food for many fish species and vertebrates. Investigations on factors that determine mollusc species richness and distribution in wetland systems are scarce in the Neotropical region. The main goal of this study was to determine how much variation in mollusc richness and composition is explained by area, hydroperiod, altitude, water conductivity, and dominant aquatic vegetation. This survey was performed in an extensive area of a Neotropical region (~280,000 km² in southern Brazil, with a large number of wetland systems (111 and covering a wide gradient of altitude and wetland surface area. The mollusc richness was positively associated with wetland area and negatively associated with altitude. The richness and composition of the freshwater molluscs were similar between permanent and intermittent wetlands and it did not differ significantly between aquatic bed and emergent wetlands. The first three axes of CCA explained 16.2% of the total variation in the composition of the freshwater mollusc observed. The variation in the composition had a correlation with wetland area, altitude and water conductivity. Our results showed that the wetlands are important habitats for molluscs in southern Brazil, and that the richness and the composition of molluscs were associated with area, altitude, water conductivity and dominant vegetation.Moluscos límnicos desempenham um papel importante em ecossistemas aquáticos, fornecendo alimento para diversos peixes e vertebrados. Investigações sobre os fatores que determinam a riqueza e a distribuição das espécies de moluscos em áreas úmidas são escassos na região neotropical. O principal objetivo deste estudo foi determinar a variação na riqueza e na composição de moluscos em função da área, hidroperíodo, altitude, condutividade da água e tipo de vegetação aquática dominante. Este estudo foi desenvolvido em uma extensa

  13. Shell biofilm-associated nitrous oxide production in marine molluscs: processes, precursors and relative importance.

    Science.gov (United States)

    Heisterkamp, Ines M; Schramm, Andreas; Larsen, Lone H; Svenningsen, Nanna B; Lavik, Gaute; de Beer, Dirk; Stief, Peter

    2013-07-01

    Emission of the greenhouse gas nitrous oxide (N2 O) from freshwater and terrestrial invertebrates has exclusively been ascribed to N2 O production by ingested denitrifying bacteria in the anoxic gut of the animals. Our study of marine molluscs now shows that also microbial biofilms on shell surfaces are important sites of N2 O production. The shell biofilms of Mytilus edulis, Littorina littorea and Hinia reticulata contributed 18-94% to the total animal-associated N2 O emission. Nitrification and denitrification were equally important sources of N2 O in shell biofilms as revealed by (15) N-stable isotope experiments with dissected shells. Microsensor measurements confirmed that both nitrification and denitrification can occur in shell biofilms due to a heterogeneous oxygen distribution. Accordingly, ammonium, nitrite and nitrate were important drivers of N2 O production in the shell biofilm of the three mollusc species. Ammonium excretion by the animals was found to be sufficient to sustain N2 O production in the shell biofilm. Apparently, the animals provide a nutrient-enriched microenvironment that stimulates growth and N2 O production of the shell biofilm. This animal-induced stimulation was demonstrated in a long-term microcosm experiment with the snail H. reticulata, where shell biofilms exhibited the highest N2 O emission rates when the animal was still living inside the shell. © 2012 John Wiley & Sons Ltd and Society for Applied Microbiology.

  14. SURVEY ON V. CHOLERAE, V. VULNIFICUS AND V. PARAHAEMOLYTICUS IN BIVALVE MOLLUSCS OF THE ADRIATIC SEA AND PROPOSAL OF AN ANALYTICAL PROTOCOL

    Directory of Open Access Journals (Sweden)

    M.L. Valeri

    2009-06-01

    Full Text Available Bivalve molluscs from Adriatic sea were analyzed for V. parahaemolyticus, V. cholerae e V. vulnificus presence. The isolates on TCBS Agar and m-CPC Agar were selected on the basis of a new biochemical screening, that showed a good performance, because among 2344 strains from primary culture only 237 (10% were presumptively assigned to the species of interest. The PCR analyses was performed for the target genes toxR hlyA, ctxA, tcpI (V. cholerae, toxR, tl, tdh, trh (V. parahaemolyticus, vvhA and viuB (V. vulnificus. Among the 9 strains confirmed to belong to V. parahaemolyticus specie, 6 were sucrose positive. On 215 samples of molluscs only 5 resulted positive for V. parahaemolyticus being toxR+, tl+, although non pathogenic (tdh-, trh-, and none for V. cholerae e V. vulnificus.

  15. Impoverishment of recent floodplain forest mollusc fauna in the lower Ohře River (Czech Republic) as a result of prehistoric human impact

    Czech Academy of Sciences Publication Activity Database

    Juřičková, L.; Horáčková, J.; Ložek, Vojen; Horsák, M.

    2013-01-01

    Roč. 42, 1 MAR (2013), s. 932-946 ISSN 0300-9483 Institutional support: RVO:67985831 Keywords : floodplain * mollusc * Ohře River (Czech Republic) Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.383, year: 2013

  16. Managing marine mollusc diseases in the context of regional and international commerce: policy issues and emerging concerns

    Science.gov (United States)

    Carnegie, Ryan B.; Arzul, Isabelle; Bushek, David

    2016-01-01

    Marine mollusc production contributes to food and economic security worldwide and provides valuable ecological services, yet diseases threaten these industries and wild populations. Although the infrastructure for mollusc aquaculture health management is well characterized, its foundations are not without flaws. Use of notifiable pathogen lists can leave blind spots with regard to detection of unlisted and emerging pathogens. Increased reliance on molecular tools has come without similar attention to diagnostic validation, raising questions about assay performance, and has been accompanied by a reduced emphasis on microscopic diagnostic expertise that could weaken pathogen detection capabilities. Persistent questions concerning pathogen biology and ecology promote regulatory paralysis that impedes trade and which could weaken biosecurity by driving commerce to surreptitious channels. Solutions that might be pursued to improve shellfish aquaculture health management include the establishment of more broad-based surveillance programmes, wider training and use of general methods like histopathology to ensure alertness to emerging diseases, an increased focus on assay assessment and validation as fundamental to assay development, investment in basic research, and application of risk analyses to improve regulation. A continual sharpening of diagnostic tools and approaches and deepening of scientific knowledge is necessary to manage diseases and promote sustainable molluscan shellfish industries. PMID:26880834

  17. Butyltin compounds in sediment and molluscs from the shipping strait between Denmark and Sweden

    International Nuclear Information System (INIS)

    Strand, Jakob; Jacobsen, Jens A.; Pedersen, Britta; Granmo, Aake

    2003-01-01

    The deposit feeding bivalve Nuculana pernula is a suitable for monitoring bioavailability of TBT in sediment along a major shipping route. - The distribution of tributyltin (TBT) contamination in the subtidal zone of the waters between Denmark and Sweden was investigated in relation to major international shipping lanes. Sediment and different benthic molluscs were sampled in transects along and perpendicularly to the shipping lanes in the Sound (Oresund) and the Kattegat/Skagerrak region. The samples were analysed for TBT and its degradation products, dibutyltin (DBT) and monobutyltin (MBT), using GC-PFPD. In sediments, the TBT concentration ranged from -1 dry weight (dw) with a strong correlation between the TBT concentration and the organic fraction in sediment (r 2 =0.90) in the samples collected in the Sound, where the highest concentrations were found. This relationship was not observed in the samples from the Kattegat because the TBT concentration in most sediment samples was below the limit of detection. In the molluscs, TBT and its degradation products were detected in all samples from the entire area with concentrations ranging from 8.1 ng g -1 dw in Buccinum undatum to 1316 ng g -1 dw in Nuculana pernula. The deposit-feeding bivalve N. pernula was found to have a particularly high accumulation potential for TBT. In addition, a strong correlation between TBT concentrations in sediment and N. pernula was found. Therefore this species seems to be an ideal organism for monitoring sediment contamination. The TBT concentration in N. pernula was found to decrease gradually along the shipping lanes from the Sound, through the Kattegat and into the Skagerrak

  18. Behaviour of molluscs in cantabrian biota with respect to the activity present in the marine medium

    International Nuclear Information System (INIS)

    Montesinos, M.; Santos, A.M. de los

    1981-01-01

    The behaviour of molluscs with regard to the activity present in the marine medium is studied. For this purpose three large groups are considered, with special reference to their ecology and their particular mode of incorporating activity. Determinations are made of the total alpha and beta activity, as well as that due to elements such as 90 Sr, 137 Cs and natural U, in the organisms in question and in their eco-environment. A comparison is likewise established between the biocoenoses inhabiting Cantabrian and Mediterranean biota. (author)

  19. Assessing the presence of marine toxins in bivalve molluscs from southwest India.

    Science.gov (United States)

    Turner, Andrew D; Dhanji-Rapkova, Monika; Rowland-Pilgrim, Stephanie; Turner, Lucy M; Rai, Ashwin; Venugopal, Moleyur N; Karunasagar, Indrani; Godhe, Anna

    2017-12-15

    The south west coast of India has been showing a steady increase in shellfish cultivation both for local consumption and fishery export, over recent years. Perna viridis and Crassostrea madrasensis are two species of bivalve molluscs which grow in some selected regions of southern Karnataka, close to the city of Mangalore. In the early 1980s, shellfish consumers in the region were affected by intoxication from Paralytic Shellfish Poison present in local bivalves (clams and oysters) resulting in hospitalisation of many, including one fatality. Since then, there have been no further reports of serious shellfish intoxication and there is little awareness of the risks from natural toxins and no routine monitoring programme in place to protect shellfish consumers. This study presents the findings from the first ever systematic assessment of the presence of marine toxins in mussels and oysters grown in four different shellfish harvesting areas in the region. Shellfish were collected and subjected to analysis for ASP, PSP and lipophilic toxins, as well as a suite of non-EU regulated toxins such as tetrodotoxin and selected cyclic imines. Results revealed the presence of low levels of PSP toxins in oysters throughout the study period. Overall, total toxicities reached a maximum of 10% of the EU regulatory limit of 800 μg STX eq/kg. Toxin profiles were similar to those reported from the 1980 outbreak. No evidence was found for significant levels of ASP and lipophilic toxins, although some cyclic imines were detected, including gymnodimine. The results indicated that the risk to shellfish consumers during this specific study period would have been low. However, with historical evidence for extremely high levels of PSP toxins in molluscs, there is a strong need for routine surveillance of shellfish production areas for marine toxins, in order to mitigate against human health impacts resulting from unexpected harmful algal blooms, with potentially devastating socio

  20. Detection of Bioactive Compounds in the Mucus Nets of Dendropoma maxima, Sowerby 1825 (Prosobranch Gastropod Vermetidae, Mollusca

    Directory of Open Access Journals (Sweden)

    Anne Klöppel

    2013-01-01

    Full Text Available The sessile suspension-feeding wormsnail Dendropoma maxima, Sowerby 1825 (Vermetidae secretes a mucus net to capture planktonic prey. The nets are spread out over the corals and often have remarkable deleterious effects on them like changes in growth form and pigmentation shifts not uncommonly resulting in tissue necrosis. Until now, there is no explanation for this phenomenon although the indication as well as theories about its genesis is mentioned in several publications. Vermetids are well studied concerning the intraspecific competition with neighboring individuals but not in their interaction with other taxa like corals or fish. We did extensive in situ video recording and observed that fish avoided the plankton-load nets although several specialized taxa are known to be molluscivores, mucivores, and/or feed on plankton. As many molluscs use chemical weapons to combat feeding pressure and to defend themselves against predators, we screened empty and plankton-load mucus nets for potential bioactive metabolites. Bioactivity testing was performed with a recently developed system based on a chromatographic separation (high-performance thin-layer chromatography (HPTLC and a bioassay with luminescent bacteria Vibrio fischeri. Thus, we found at least two active compounds exclusively accumulated by the wormsnails themselves. This is the first record of bioactive properties in the whole family of Vermetidae.

  1. Histopathologic and biochemical responses in Arctic marine bivalve molluscs exposed to experimentally spilled oil

    Energy Technology Data Exchange (ETDEWEB)

    Neff, J.M.; Hillman, R.E.; Carr, R.S.; Buhl, R.L.; Lahey, J.I.

    1987-01-01

    Following two experimental spills of chemically dispersed and undispersed crude oil in shallow bays on the northwest coast of Baffin Island bivalve molluscs accumulated significant amounts of petroleum hydrocarbons in bay receiving dispersed oil and in those receiving crude oil alone. Specimens of Mya truncata and Macoma calcarea for histopathologic examination were collected immediately before, immediately after and one year after the experimental oil spills. Immediately after there was increased gill and digestive tract necrosis in Mya from the chemically dispersed oil. After one year a few clams had granulocytomas throughout the tissues. Three clams receiving oil alone collected one year after the spill had invasive neoplasias. There were few lesions in Macoma immediatelly after or one year after the spill; animals had a high incidence of vacuolization of the digestive tubule epithelium. The incidence of parasitism and hemocytic infiltration also was higher in Maccoma. Clams Mya truncata were collected for biochemical analysis before, after and two weeks after the simulated oil spills. Concentations in the clam tissues of glucose, glycogen, trehalose, total lipid, and free amino acids were measured; free amino acids in adductor muscles were the most useful indices of pollutant stress. The results of the biochemical analyses indicate that Mya were not severely stressed by either dispersed oil or oil alone. After two weeks, clams from the dispersed oil bays were nearly normal, while those from the bay receiving oil alone appeared stressed. These results seem to corroborate results that the acute effects of dispersed oil are greater than those of undispersed oil, but effects of undispersed oil on infaunal molluscs develop more slowly and persist longer than those from dispersed oil. 43 refs., 2 figs., 6 tabs.

  2. ESR-dating of subfossil mollusc shells: the problem of absorbed paleodose fading

    International Nuclear Information System (INIS)

    Molod'kov, A.

    1988-01-01

    Detailed investigation of paleodosimetric prperties of subfossil mollusc shells has been carried out with respect to their dating by ESR-spectroscopy. Attention has been paid to the connection between the absorbed paleodose value and factors on the upper dating limit. Energetic parameters of the CO 3 3- centres have been determined in the calcareous shell skeleton serving as a paleodetector: E=1.515 eV, ν 0 =8x10 13 s -1 , τ=1.14x10 6 years at 5 deg C. Mathematical models have been elaborated for the accumulation of paleodose in natural conditions. New paleodosimetric equations proposed for calculating the age of shells and some minerals may be applied both to ESR- and thermoluminescence-dating. The proposed method enables one to date the shells within the time span of nx10 2 -nx10 6 years

  3. Concentration of Organochlorine and Organophosphorus Pesticides in Different Molluscs from Tighra Reservoir, Gwalior, India.

    Science.gov (United States)

    Mamta; Rao, R J; Wani, Khursheed Ahmad

    2015-09-01

    Concentration of organochlorine and organophosphorus pesticides and their metabolites were determined in whole body homogenate of L. acuminata, I. exustus, V. dissimilis, V. bengalensis, from Tighra Reservoir during summer and post monsoon season using GC-MS technique. The different types of pesticides viz., HCB, heptachlor, aldrin, endosulfan, dieldrin, p,p-DDT, choloropyrifos, methyl parathion, dicholorovos, ethion, malathion, parathion were found in resident molluscs studied. Concentration of these pesticides varied independently during the summer and the post monsoon season at monitored sites. The study concluded that presence of pesticides in Tighra Reservoir is a major concern on public and ecosystem health and use of biopesticides in the adjacent area of Reservoir is highly recommended.

  4. Major and c-series gangliosides in lenticular tissues: mammals to molluscs.

    Science.gov (United States)

    Saito, M; Sugiyama, K

    2001-10-01

    Gangliosides of eye lenses were examined in mammals (rat, rabbits, pig, cow), bird (chicken), reptile (terrapin), amphibian (bullfrog), bony fish (red sea bream, bluefin tuna, bonito, Pacific mackerel) and molluscs (common squid, Pacific octopus). Besides the fact that GM3 was the common ganglioside species, the composition of major gangliosides in mammalian eye lenses significantly differed from each other. While gangliotetraose gangliosides were abundant in rat eye lens, they did not constitute major components in porcine and bovine tissues. The c-series ganglioside GT3 was expressed in rat eye lenses but were practically absent in other mammalian tissues. The composition of major gangliosides in eye lenses of lower animals varied from species to species, whereas c-series gangliosides were consistently expressed, showing similar compositional profiles. Our results demonstrate the species-specific compositions of lenticular gangliosides. Evidence was also provided suggesting that eye lenses of common squid (Todarodes pacificus) and Pacific octopus (Octopus vulgaris) express gangliosides including gangliotetraose species and c-series gangliosides.

  5. Menadione Sodium Bisulphite (MSB) enhances the resistance response of tomato, leading to repel mollusc pests.

    Science.gov (United States)

    Carrillo-Perdomo, Estefanía; Jiménez-Arias, David; Aller, Ángel; Borges, Andrés A

    2016-05-01

    Snails and slugs are terrestrial gastropods representing an important biotic stress that adversely affects crop yields. These pests are typically controlled with molluscicides, which produce pollution and toxicity and further induce the evolution of resistance mechanisms, making pest management even more challenging. In our work, we have assessed the efficacy of two different plant defence activators, menadione sodium bisulphite (MSB) and 1,2,3-benzothiadiazole-7-thiocarboxylic acid S-methyl ester (BTH), as inducers of resistance mechanisms of the model plant for defence, Solanum lycopersicum, against the generalist mollusc Theba grasseti (Helicidae). The study was designed to test the feeding behaviour and choice of snails, and also to analyse the expression profile of different genes specifically involved in defence against herbivores and wounds. Our data suggest that, through the downregulation of the terpene volatile genes and the production of proteinase inhibitors, treated MSB plants may be less apparent to herbivores that use herbivore-induced plant volatiles for host location. By contrast, BTH was not effective in the treatment of the pest, probably owing to an antagonistic effect derived from the induction of both salicylic-acid-dependent and jasmonic-acid-dependent pathways. This information is crucial to determine the genetic basis of the choice of terrestrial gastropod herbivores in tomato, providing valuable insight into how the plant defence activators could control herbivore pests in plants. Our work not only reports for the first time the interaction between tomato and a mollusc pest but also presents the action of two plant defence inductors that seems to produce opposed responses by inducing resistance mechanisms through different defence pathways. © 2015 Society of Chemical Industry.

  6. Relationship between anti-oxidant capacity and manganese accumulation in the soft tissues of two freshwater molluscs: Unio pictorum mancus (Lamellibranchia, Unionidae and Viviparus ater (Gastropoda, Prosobranchia

    Directory of Open Access Journals (Sweden)

    Oscar RAVERA

    2005-08-01

    Full Text Available Manganese is an element of great importance in the life cycle of plants and animals. For example, it plays an essential role as an activator of various enzymatic systems such as isoenzymes of superoxide dismutase. Freshwater Unionidae concentrate relatively large amounts of manganese in their tissues, but little is known about the physiological role of this metal. The aim of this research is to acquire a better knowledge of the role of manganese in molluscs which accumulate large amounts of this metal and in those with low manganese concentrations. As manganese is one of the metals present in the superoxide molecule, the possible relationship between manganese concentration in the soft tissues of molluscs and the antioxidant capacity of the metal can usefully be tested. To this end two species of molluscs were analysed: Unio pictorum mancus (Lamellibranchia, Unionidae, which is very rich in manganese, and Viviparus ater (Gastropoda, Prosobranchia which has a low manganese content. The adults of both species were analysed for manganese concentration by ICP, and for antioxidant capacity as RAC (Relative Antioxidant Capacity by a superoxide dismutase method. The results clearly demonstrate the active role played by manganese against free radicals and consequently the important role of the metal in protecting Unio against oxidative stress. The low concentration of manganese in Viviparus may be the result of the effective excretion of this metal, as was found for ruthenium.

  7. Structural determination of the carbohydrate chains from arthropod and mollusc hemocyanin by means of 500-MHz 1H-NMR spectroscopy

    International Nuclear Information System (INIS)

    Kuik, J.A. van.

    1987-01-01

    In this thesis carbohydrate structures of hemocyanins of arthropods and molluscs are studied. Hemocyanins are high-molecular-mass, copper-containing oxygen-transport proteins. The function of these carbohydrate chains are yet still unknown. It is not probable that they play a role in the oxygen-binding processes. They are rather thought to have a function in the build-up of the hemocyanin molecules. 286 refs.; 30 figs.; 25 tabs

  8. Characterization of South American Snails of the Genus Biomphalaria (Basommatophora: Planorbidae and Schistosoma mansoni (Platyhelminthes: Trematoda in Molluscs by PCR-RFLP

    Directory of Open Access Journals (Sweden)

    Roberta Lima Caldeira

    2016-01-01

    Full Text Available The identification of snails of the genus Biomphalaria can be done using morphological characteristics which depends on the size of the snails and skill and knowledge of researcher. These methods sometimes are not adequate for identification of species. The PCR-RFLP, using the ITS region of the rDNA, has been used to identify Brazilian species of the genus Biomphalaria. Nevertheless, there is a lack of information about snails from other Latin American countries. In addition, some snails may be infected by Schistosoma mansoni and when submitted to PCR-RFLP they show molecular profiles different from those previously standardized for the other mollusc species. In this work the molecular profiles of 15 species and the subspecies were established by PCR-RFLP of ITS-rDNA with the enzyme DdeI. Moreover, the molecular profiles of host species, B. glabrata, B. straminea, B. tenagophila, and B. prona, infected by S. mansoni were also established. The molluscs were dissected to permit morphological identification. These results contribute to a correct identification of snails of the genus Biomphalaria and detection of these snails infected by S. mansoni.

  9. Ministry of Health Circular No. 36 on the physical requirements for marine waters intended for mollusc culture (Section 12 of Act No. 192 of 2 May 1977 and Section 5 of Ministerial Decree of 27 April 1978)

    International Nuclear Information System (INIS)

    1979-01-01

    This Circular by the Minister of Health follows up a Ministerial Decree of 27 April 1978 made in implementation of the 1977 Act on health protection standards for the production of and trade in molluscs. It fixes the microbiological, biological, chemical and physical quality requirements for waters intended for molluscs culture and production. These include radionuclide concentrations which must not exceed the limits laid down by Presidential Decree No. 185 of 13 February 1964 on radiation protection. (NEA) [fr

  10. THE SECTION OF TORRE PICCHIO (TERNI, UMBRIA, CENTRAL ITALY:A VILLAFRANCHIAN SITE RICH IN VERTEBRATES, MOLLUSCS,OSTRACODS AND PLANTS

    Directory of Open Access Journals (Sweden)

    ODOARDO GIROTTI

    2003-03-01

    Full Text Available Fluvial deposits of the S. Maria di Ciciliano Formation crop out near Montecastrilli (Terni, in the southwestern branch of the Tiberino Basin.  Many specimens of plants ("mummified" woods, fruits and seeds, freshwater molluscs, ostracods, vertebrate bones and coprolites were collected at Torre Picchio. This small outcrop contains a fairly rich record of fruits and seeds, among which about 50 species were identified; the most frequent invariably belong to submerged, floating and emergent aquatic herbs, possibly because these were buried not far from their place of growth, thus representing the ancient local vegetation.  The fruits and seeds of woody plants, including several exotic elements, were transported from neighbouring areas and indicate a paleoclimate similar to the present day, though slightly wetter.  Among molluscs, three distinct assemblages were found, indicating fluvial, swampy and lacustrine environment, respectively.  They contain taxa of biochronological interest, most of them typical of Early Pleistocene deposits (late Villafranchian, but making their first appearance in the Late Pliocene (Middle Villafranchian. One species, Margarifera (Pseudunio auricularia, represents the oldest record everywhere, since it was known, so far, only from the Middle Pleistocene upwards.  As palaeoenvironmental indicators, the ostracods complete the information given by molluscs.  Vetrebrates are represented by large and small mammals, rare birds, reptiles, amphibians and some fishes.  A great number of coprolites was collected as well.  The mammal assemblage shows affinities with the Costa S. Giacomo and Olivola F. U. (Middle and Late Villafranchian, Late Pliocene. Mimomys medasensis, an Iberoccitane element, is signaled for the first time in Italy.  From the geological point of view, the S. Maria di Ciciliano Fm. is interfingering with the marine Chiani-Tevere Fm., which is mostly Santernian in age and lies unconformably on the Middle

  11. Molluscs as evidence for a late Pleistocene and early Holocene humid period in the southern coastal desert of Peru (14.5°S)

    Science.gov (United States)

    Mächtle, Bertil; Unkel, Ingmar; Eitel, Bernhard; Kromer, Bernd; Schiegl, Solveig

    2010-01-01

    The southern Peruvian coastal desert around Palpa, southern Peru (14.5°S) is currently characterized by hyper-arid conditions. However, the presence of two species of molluscs ( Scutalus, Pupoides) and desert-loess deposits indicates the past development of semi-desert and grassland ecosystems caused by a displacement of the eastern desert margin due to hydrological changes. Radiocarbon dating shows that the transition to a semi-arid climate in the southern Peruvian coastal desert took place during the Greenland interstadial 1, ˜ 13.5 cal ka BP. At the beginning of the Holocene, the mollusc fauna vanished due to increasing humidity and the development of grasslands. Dust particles were fixed by the grasses, as indicated by abundant Poaceae phytoliths, and desert loess was formed. The humid period we observe here is out of phase with the palaeoenvironmental records from the Titicaca region, which indicates dry conditions at that time. This paper offers a new idea for this contradiction: an orbitally driven meridional shift of the Bolivian high might have altered the moisture supply across the Andes.

  12. Mollusc succession of a prehistoric settlement area during the Holocene: A case study of the České středohoří Mountains (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Juřičková, L.; Horáčková, J.; Jansová, A.; Ložek, Vojen

    2013-01-01

    Roč. 23, č. 12 (2013), s. 1811-1823 ISSN 0959-6836 Institutional support: RVO:67985831 Keywords : České středohoří Mountains * Holocene * mollusc succession * prehistoric settlement * radiocarbon AMS dating Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.794, year: 2013

  13. Turning snails into slugs: induced body plan changes and formation of an internal shell.

    Science.gov (United States)

    Osterauer, Raphaela; Marschner, Leonie; Betz, Oliver; Gerberding, Matthias; Sawasdee, Banthita; Cloetens, Peter; Haus, Nadine; Sures, Bernd; Triebskorn, Rita; Köhler, Heinz-R

    2010-01-01

    The archetypal body plan of conchiferan molluscs is characterized by an external calcareous shell, though internalization of shells has evolved independently in a number of molluscan clades, including gastropod families. In gastropods, the developmental process of torsion is regarded as a hallmark that is associated with a new anatomical configuration. This configuration is present in extant prosobranch gastropod species, which predominantly bear external shells. Here, we show that short-term exposure to platinum during development uncouples at least two of the processes associated with torsion of the freshwater snail Marisa cornuarietis. That is, the anus of the treated snails is located anteriorly, but the gill and the designated mantle tissue remains in a posterior location, thus preventing the formation of an external shell. In contrast to the prosobranchian archetype, platinum treatment results in the formation of a posterior gill and a cone-shaped internal shell, which persists across the lifetime. This first finding of artificially induced snail-slug conversion was also seen in the pulmonate snail Planorbarius corneus and demonstrates that selective alteration of embryonic key processes can result in fundamental changes of an existing body plan and-if altered regulation is inherited-may give rise to a new one. © 2010 Wiley Periodicals, Inc.

  14. Linking δ15N and histopathological effects in molluscs exposed in situ to effluents from land-based marine fish farms

    International Nuclear Information System (INIS)

    Carballeira, C.; Espinosa, J.; Carballeira, A.

    2011-01-01

    Highlights: ► Land-based marine aquaculture effluents induce branchial exfoliation and phagocytic haemocytosis in exposed molluscs. ► Transplanted clams are more sensitive to aquaculture discharges than native mussels. ► δ 15 N in organisms is a cost-effective means of biomonitoring exposure to contamination from aquaculture. ► δ 15 N analysis may facilitate the evaluation of potential effects at the tissue level. - Abstract: Histopathological alterations can indicate time-integrated impacts on organisms stemming from alterations at lower biological organisation levels. Long-term (native mussels) and short-term (transplanted clams) changes in the tissues of molluscs exposed to the effluents from two land-based marine fish farms (LBMFFs) were determined. Histological alterations were related to the δ 15 N isotopic signal measured in mussels and macroalgae. Effluents from LBMFFs were found to cause severe and moderate gill filament exfoliation in clams and mussels, respectively. Some transplanted clams showed severe degrees of hemocytic phagocytosis in gonads and connective tissue. In an attempt to semi-quantitatively summarize the observed histopathological alterations, a weighted index of damage (WID) was calculated for each type of alteration, species and sampling site. The WID was clearly related to the δ 15 N descriptor of exposure. Further studies aimed at standardizing this relationship may establish critical thresholds of the descriptor for its implementation within environmental monitoring plans for LBMFFs.

  15. Bioaccumulation of microcystins in two freshwater gastropods from a cyanobacteria-bloom plateau lake, Lake Dianchi

    International Nuclear Information System (INIS)

    Zhang Junqian; Wang Zhi; Song Zhuoyan; Xie Zhicai; Li Lin; Song, Lirong

    2012-01-01

    To investigate the bioaccumulation patterns of microcystins (MCs) in organs of two gastropods, samples were collected in Lake Dianchi monthly from May to October, 2008, when cyanobacteria typically bloom. The average MCs concentrations for Radix swinhoei (pulmonate) and Margarya melanioides (prosobranch) tended to be similar for the different organs: the highest values in the hepatopancreas (9.33 by 3.74 μg/g DW), followed by digestive tracts (1.66 by 3.03 μg/g DW), gonads (0.45 by 1.34 μg/g DW) and muscles (0.22 by 0.40 μg/g DW). Pulmonate had higher value than prosobranch because of the stronger bioaccumulation ability in hepatopancreas. The levels in organs of R. swinhoei were correlated with environmentally dissolved MCs, but influenced by intracellular MCs for M. melanioides. The estimated MCs concentrations in edible parts of M. melanioides were beyond the WHO’s provisional tolerable daily intake (0.04 μg/kg), suggesting the risk of consumption of M. melanioides from the lake. Highlights: ► We probe bioaccumulated patterns of microcystins in organs of pulmonate and prosobranch. ► The highest microcystins in hepatopancreas for both snails. ► The higher microcystins for pulmonate results from the stronger bioaccumulation ability in hepatopancreas. ► Environmentally dissolved microcystins are the main sources for pulmonate, but intracellular for prosobranch. ► Suggesting the risk of consumption snails in the studying regions. - Higher bioaccumulation MCs level for pulmonate mainly contributed to the stronger bioaccumulation ability in its hepatopancreas.

  16. Inter-species variations in metal concentration in the soft tissue of some molluscs from the coasts of Aden Governorate

    International Nuclear Information System (INIS)

    Ali, A. A.; Baharoon, A. Ab.

    2002-01-01

    Nearly most of the molluscs are considered as good biomonitors for heavy metals pollution due to their mode of life, but there are differences in the bioavailability of heavy metals in their soft tissues. This research shows that Turbo coronatus and A canthopleura haddoni are the best to accumulate Cd, Pb, Co, Cr, As for Ni, P. perna and the latter two speciments show higher concentrations. Turbo coronatus and Ostrea cucullata are the best to accumulate Cu, and Zn. A canthopleura haddoni and Veneridae pitar sp. show higher availability of Fe, and Mn in their soft tissues. (author)

  17. Tributyltin accumulation and effects in marine molluscs from West Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Strand, J.; Asmund, G

    2003-05-01

    Tributyltin is accumulated in marine molluscs living in Greenland, with the highest levels found in harbour areas. - The levels of the antifouling agent tributyltin (TBT) and its breakdown products in bivalves were investigated in 1999-2000 at six areas along the west coast of Greenland with focus on locations inside and outside harbours. In addition female gastropods were examined for the development of TBT-induced masculine characteristics in form of imposex or intersex. The highest TBT concentration, 254 ng g{sup -1} ww, was found in the bivalve Mytilus edulis sampled inside Nuuk harbour, but significant TBT concentrations were also present in bivalves from the other harbour areas. Only low levels of TBT were detected in bivalves sampled outside the harbours and in several of the samples the TBT level was below the detection limit. The examination of neogastropods like Buccinum revealed that imposex development occurred in all the harbours. In contrast, imposex was not found in any neogastropods sampled outside the harbour areas. However, the value of marine neogastropods as indicators of TBT contamination in West Greenland seems limited, because of large species diversity and the difficulties in sampling enough specimens at least with the current sampling strategy. No effects, which could be related to TBT contamination, were found in the most abundant tidal gastropod in West Greenland, Littorina saxatilis.

  18. Tributyltin accumulation and effects in marine molluscs from West Greenland

    International Nuclear Information System (INIS)

    Strand, J.; Asmund, G.

    2003-01-01

    Tributyltin is accumulated in marine molluscs living in Greenland, with the highest levels found in harbour areas. - The levels of the antifouling agent tributyltin (TBT) and its breakdown products in bivalves were investigated in 1999-2000 at six areas along the west coast of Greenland with focus on locations inside and outside harbours. In addition female gastropods were examined for the development of TBT-induced masculine characteristics in form of imposex or intersex. The highest TBT concentration, 254 ng g -1 ww, was found in the bivalve Mytilus edulis sampled inside Nuuk harbour, but significant TBT concentrations were also present in bivalves from the other harbour areas. Only low levels of TBT were detected in bivalves sampled outside the harbours and in several of the samples the TBT level was below the detection limit. The examination of neogastropods like Buccinum revealed that imposex development occurred in all the harbours. In contrast, imposex was not found in any neogastropods sampled outside the harbour areas. However, the value of marine neogastropods as indicators of TBT contamination in West Greenland seems limited, because of large species diversity and the difficulties in sampling enough specimens at least with the current sampling strategy. No effects, which could be related to TBT contamination, were found in the most abundant tidal gastropod in West Greenland, Littorina saxatilis

  19. Metals in molluscs and algae: A north-south Tyrrhenian Sea baseline

    International Nuclear Information System (INIS)

    Conti, Marcelo Enrique; Finoia, Maria Grazia

    2010-01-01

    We develop a 800 km long relative baseline of metal pollution for the Tyrrhenian Sea, from the north of Naples to south of Sicily (Italy), based on spatio-temporal (1997-2004) concentrations of trace metals in marine organisms and on the bioaccumulative properties of those organisms. The study concerns sites in the gulf of Gaeta-Formia, near Naples, and three islands north, west, and south of Sicily: Ustica, Favignana and Linosa. The five metals are: cadmium, chromium, copper, lead, and zinc; the species include: Monodonta turbinata (n = 161), Patella caerulea (n = 244) and the algae Padina pavonica (n = 84). We use Johnson's (1949) probabilistic method to determine the type of distribution that accounts for our data. It is a system of frequency curves that represents the transformation of the standard normal curves. We find an N-S pollution gradient in molluscs considered: the lowest metal pollution occurs around the Sicilian islands. Our method can accurately characterize marine pollution by contributing to: policy-making, coastal resources management, the assessments of environmental damages from marine accidents and other events. The method here presented is a useful tool for pollution comparisons purposes among ecosystems (i.e., risk monitoring) and it is an ideal starting point for its application on a global scale.

  20. Spatial distribution of epibenthic molluscs on a sandstone reef in the Northeast of Brazil

    Directory of Open Access Journals (Sweden)

    AS. Martinez

    Full Text Available The present study investigated the distribution and abundance of epibenthic molluscs and their feeding habits associated to substrate features (coverage and rugosity in a sandstone reef system in the Northeast of Brazil. Rugosity, low coral cover and high coverage of zoanthids and fleshy alga were the variables that influenced a low richness and high abundance of a few molluscan species in the reef habitat. The most abundant species were generalist carnivores, probably associated to a lesser offer and variability of resources in this type of reef system, when compared to the coral reefs. The results found in this study could reflect a normal characteristic of the molluscan community distribution in sandstone reefs, with low coral cover, or could indicate a degradation state of this habitat if it is compared to coral reefs, once that the significantly high coverage of fleshy alga has been recognized as a negative indicator of reef ecosystems health.

  1. Spatial distribution of epibenthic molluscs on a sandstone reef in the Northeast of Brazil.

    Science.gov (United States)

    Martinez, A S; Mendes, L F; Leite, T S

    2012-05-01

    The present study investigated the distribution and abundance of epibenthic molluscs and their feeding habits associated to substrate features (coverage and rugosity) in a sandstone reef system in the Northeast of Brazil. Rugosity, low coral cover and high coverage of zoanthids and fleshy alga were the variables that influenced a low richness and high abundance of a few molluscan species in the reef habitat. The most abundant species were generalist carnivores, probably associated to a lesser offer and variability of resources in this type of reef system, when compared to the coral reefs. The results found in this study could reflect a normal characteristic of the molluscan community distribution in sandstone reefs, with low coral cover, or could indicate a degradation state of this habitat if it is compared to coral reefs, once that the significantly high coverage of fleshy alga has been recognized as a negative indicator of reef ecosystems health.

  2. In Vivo Recording of Neural and Behavioral Correlates of Anesthesia Induction, Reversal, and Euthanasia in Cephalopod Molluscs

    Directory of Open Access Journals (Sweden)

    Hanna M. Butler-Struben

    2018-02-01

    Full Text Available Cephalopod molluscs are among the most behaviorally and neurologically complex invertebrates. As they are now included in research animal welfare regulations in many countries, humane and effective anesthesia is required during invasive procedures. However, currently there is no evidence that agents believed to act as anesthetics produce effects beyond immobility. In this study we demonstrate, for the first time, that two of the most commonly used agents in cephalopod general anesthesia, magnesium chloride and ethanol, are capable of producing strong and reversible blockade of afferent and efferent neural signal; thus they are genuine anesthetics, rather than simply sedating agents that render animals immobile but not insensible. Additionally, we demonstrate that injected magnesium chloride and lidocaine are effective local anesthetic agents. This represents a considerable advance for cephalopod welfare. Using a reversible, minimally invasive recording procedure, we measured activity in the pallial nerve of cuttlefish (Sepia bandensis and octopus (Abdopus aculeatus, Octopus bocki, during induction and reversal for five putative general anesthetic and two local anesthetic agents. We describe the temporal relationship between loss of behavioral responses (immobility, loss of efferent neural signal (loss of “consciousness” and loss of afferent neural signal (anesthesia for general anesthesia, and loss of afferent signal for local anesthesia. Both ethanol and magnesium chloride were effective as bath-applied general anesthetics, causing immobility, complete loss of behavioral responsiveness and complete loss of afferent and efferent neural signal. Cold seawater, diethyl ether, and MS-222 (tricaine were ineffective. Subcutaneous injection of either lidocaine or magnesium chloride blocked behavioral and neural responses to pinch in the injected area, and we conclude that both are effective local anesthetic agents for cephalopods. Lastly, we

  3. In Vivo Recording of Neural and Behavioral Correlates of Anesthesia Induction, Reversal, and Euthanasia in Cephalopod Molluscs.

    Science.gov (United States)

    Butler-Struben, Hanna M; Brophy, Samantha M; Johnson, Nasira A; Crook, Robyn J

    2018-01-01

    Cephalopod molluscs are among the most behaviorally and neurologically complex invertebrates. As they are now included in research animal welfare regulations in many countries, humane and effective anesthesia is required during invasive procedures. However, currently there is no evidence that agents believed to act as anesthetics produce effects beyond immobility. In this study we demonstrate, for the first time, that two of the most commonly used agents in cephalopod general anesthesia, magnesium chloride and ethanol, are capable of producing strong and reversible blockade of afferent and efferent neural signal; thus they are genuine anesthetics, rather than simply sedating agents that render animals immobile but not insensible. Additionally, we demonstrate that injected magnesium chloride and lidocaine are effective local anesthetic agents. This represents a considerable advance for cephalopod welfare. Using a reversible, minimally invasive recording procedure, we measured activity in the pallial nerve of cuttlefish ( Sepia bandensis ) and octopus ( Abdopus aculeatus, Octopus bocki ), during induction and reversal for five putative general anesthetic and two local anesthetic agents. We describe the temporal relationship between loss of behavioral responses (immobility), loss of efferent neural signal (loss of "consciousness") and loss of afferent neural signal (anesthesia) for general anesthesia, and loss of afferent signal for local anesthesia. Both ethanol and magnesium chloride were effective as bath-applied general anesthetics, causing immobility, complete loss of behavioral responsiveness and complete loss of afferent and efferent neural signal. Cold seawater, diethyl ether, and MS-222 (tricaine) were ineffective. Subcutaneous injection of either lidocaine or magnesium chloride blocked behavioral and neural responses to pinch in the injected area, and we conclude that both are effective local anesthetic agents for cephalopods. Lastly, we demonstrate that a

  4. Effects of urban wastewater on crab and mollusc assemblages in equatorial and subtropical mangroves of East Africa

    Science.gov (United States)

    Cannicci, Stefano; Bartolini, Fabrizio; Dahdouh-Guebas, Farid; Fratini, Sara; Litulo, Carlos; Macia, Adriano; Mrabu, Elisha J.; Penha-Lopes, Gil; Paula, José

    2009-09-01

    Mangrove forests are known to accomplish crucial ecosystem functions and services. They are nursery areas for fish, prawns and crabs, which provide coastal communities with a variety of food, timber and chemicals, and protect coasts from catastrophic events, such as tsunamis. Recently, a novel ecological service has been proposed for mangrove systems, namely natural wastewater treatment wetlands. This hypothesis was based on experimental data collected mainly in Chinese mangrove systems, which proved that mangrove soils were efficient in absorbing nutrients. Moreover, sewage loading seemed harmless to both plants and benthic communities in these systems. However, before promoting the use of natural mangroves as pollution buffers, or constructed mangrove wetlands as sewage treatment facilities, more data are needed on their overall tolerance to organic loading. Differences in macrobenthos patterns were thus investigated between peri-urban mangroves and sites not affected by sewage disposal in East Africa. We assessed differences in epifaunal assemblages, comprising crabs and molluscs, employing multivariate ACI unbalanced analyses to compare peri-urban mangrove swamps with those characteristic of non-urban mangroves with similar ecological traits. The sampling design was spatially nested, replicates being assessed at equatorial (southern Kenya) and subtropical (southern Mozambique) sites. The results manifested a consistent increase in crab biomass at the peri-urban sites in both Kenya and Mozambique. Moreover, the peri-urban systems were richer than the non-urban mangroves, both in terms of fiddler crabs ( Uca spp.) which feed on benthic microalgae and bacteria, and sesarmids, such as Perisesarma guttatum and Neosarmatium meinerti, which feed on both substratum and leaf litter. The abundance of gastropods, in contrast, decreased significantly, especially in Kenya, mainly due to the disappearance of the mud whelk Terebralia palustris. The results thus indicate that

  5. Variation in the composition of corals, fishes, sponges, echinoderms, ascidians, molluscs, foraminifera and macroalgae across a pronounced in-to-offshore environmental gradient in the Jakarta Bay-Thousand Islands coral reef complex.

    Science.gov (United States)

    Cleary, D F R; Polónia, A R M; Renema, W; Hoeksema, B W; Rachello-Dolmen, P G; Moolenbeek, R G; Budiyanto, A; Yahmantoro; Tuti, Y; Giyanto; Draisma, S G A; Prud'homme van Reine, W F; Hariyanto, R; Gittenberger, A; Rikoh, M S; de Voogd, N J

    2016-09-30

    Substrate cover, water quality parameters and assemblages of corals, fishes, sponges, echinoderms, ascidians, molluscs, benthic foraminifera and macroalgae were sampled across a pronounced environmental gradient in the Jakarta Bay-Thousand Islands reef complex. Inshore sites mainly consisted of sand, rubble and turf algae with elevated temperature, dissolved oxygen, pH and chlorophyll concentrations and depauperate assemblages of all taxa. Live coral cover was very low inshore and mainly consisted of sparse massive coral heads and a few encrusting species. Faunal assemblages were more speciose and compositionally distinct mid- and offshore compared to inshore. There were, however, small-scale differences among taxa. Certain midshore sites, for example, housed assemblages resembling those typical of the inshore environment but this differed depending on the taxon. Substrate, water quality and spatial variables together explained from 31% (molluscs) to 72% (foraminifera) of the variation in composition. In general, satellite-derived parameters outperformed locally measured parameters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. BIOCHRONOLOGY OF SELECTED MAMMALS, MOLLUSCS AND OSTRACODS FROM THE MIDDLE PLIOCENE TO THE LATE PLEISTOCENE IN ITALY. THE STATE OF THE ART

    Directory of Open Access Journals (Sweden)

    E. GLIOZZI

    1997-11-01

    Full Text Available The Authors have elaborated four range charts of mammalian (large and micro, molluscs and fresh-water and brackish ostracodes faunas, for the selected Plio-Pleistocene fossiliferous localities of the Italy. A new Mammal Age (Aurelian correlatable to late Middle and Late Pleistocene has been defined. Inside this age two Faunal Units (Torre in Pietra and Vitinia have been defined as characteristic for Early and Middle Aurelian, while no gisements have been chosen for the late Aurelian. Biochronological units are calibrated on magnetostratigraphic and isotopic scales and by radiometric datings.    

  7. Metals in molluscs and algae: a north-south Tyrrhenian Sea baseline.

    Science.gov (United States)

    Conti, Marcelo Enrique; Finoia, Maria Grazia

    2010-09-15

    We develop a 800 km long relative baseline of metal pollution for the Tyrrhenian Sea, from the north of Naples to south of Sicily (Italy), based on spatio-temporal (1997-2004) concentrations of trace metals in marine organisms and on the bioaccumulative properties of those organisms. The study concerns sites in the gulf of Gaeta-Formia, near Naples, and three islands north, west, and south of Sicily: Ustica, Favignana and Linosa. The five metals are: cadmium, chromium, copper, lead, and zinc; the species include: Monodonta turbinata (n=161), Patella caerulea (n=244) and the algae Padina pavonica (n=84). We use Johnson's (1949) [15] probabilistic method to determine the type of distribution that accounts for our data. It is a system of frequency curves that represents the transformation of the standard normal curves. We find an N-S pollution gradient in molluscs considered: the lowest metal pollution occurs around the Sicilian islands. Our method can accurately characterize marine pollution by contributing to: policy-making, coastal resources management, the assessments of environmental damages from marine accidents and other events. The method here presented is a useful tool for pollution comparisons purposes among ecosystems (i.e., risk monitoring) and it is an ideal starting point for its application on a global scale. Copyright 2010 Elsevier B.V. All rights reserved.

  8. Oxygen isotopes of marine mollusc shells record Eocene elevation change in the Pyrenees

    Science.gov (United States)

    Huyghe, Damien; Mouthereau, Frédéric; Emmanuel, Laurent

    2012-09-01

    Constraining paleoaltimetry of collisional orogens is critical to understand the dynamics of topographic evolution and climate/tectonics retroactions. Here, we use oxygen stable-isotope record on oyster shells, preserved in marine foreland deposits, to examine the past elevation of the Pyrenees during the Eocene. Our approach is based on the comparison with the Paris basin, an intracratonic basin not influenced by orogenic growth. The finding of a shift of 1.5‰ between 49 and 41 Ma, indicating more negative δ18Oc in the south Pyrenean foreland, is interpreted to reflect the inflow of river water sourced from higher elevation in the Pyrenees. To test this and provide paleoelevation estimate, we adopt a morphologic-hydrological model accounting for the hypsometry of drainage basin. Our best fitting model shows that the Pyrenees rose up to 2000 m. This indicates that the Pyrenees reached high elevation in the Eocene, thus providing new critical constraints on their long-term orogenic development. δ18O of marine mollusc shells are proved potentially attractive for paleoelevation studies, especially for mountain belts where elevated continental surfaces have not been preserved.

  9. [SPECTRAL AND ACID-BASE PROPERTIES OF HEMOLYMPH PLASMA AND ITS FRACTIONS FROM GASTROPOD PULMONATE MOLLUSC ACHATINA FULICA].

    Science.gov (United States)

    Petrova, T A; Lianguzov, A Yu; Malygina, N M

    2016-01-01

    The set of normal biochemical indicators of the hemolymph plasma of gastropod pulmonate mollusc Achatinafulica is described. Comparative analysis of the whole plasma and its subfractions enriched and depleted of oxygen-carrying protein hemocyanin was performed by spectrophotometry and spectrofluorimetry methods. Individual features of the absorption spectra were analyzed using fourth derivatives. The optimum method for estimating protein concentration was chosen. To characterize acid-base properties of plasma hemolymph and its sub-fractions we calculated buffer capacity, equivalence points and pK values of dominant buffer groups. It is shown that the major role in maintaining the buffer capacity of hemolymph belongs to the bicarbonate system. These results are compared with data for Helix pomatia available in literature. In the future the indicators studied in this work will be used to develop ecotoxicological criteria for the environmental assessment.

  10. Angiostrongylus cantonensis infection in molluscs in the municipality of São Gonçalo, a metropolitan area of Rio de Janeiro, Brazil: role of the invasive species Achatina fulica in parasite transmission dynamics

    Directory of Open Access Journals (Sweden)

    Ana PM Oliveira

    2015-09-01

    Full Text Available The aim of this study was to analyse the infection dynamics ofAngiostrongylus cantonensisin its possible intermediate hosts over two years in an urban area in the state of Rio de Janeiro where the presence ofA. cantonensis had been previously recorded in molluscs. Four of the seven mollusc species found in the study were exotic.Bradybaena similariswas the most abundant, followed byAchatina fulica, Streptaxissp., Subulina octona, Bulimulus tenuissimus, Sarasinula linguaeformisand Leptinaria unilamellata. Only A. fulicaand B. similariswere parasitised by A. cantonensis and both presented co-infection with other helminths. The prevalence of A. cantonensisin A. fulicawas more than 50% throughout the study. There was an inverse correlation between the population size ofA. fulicaand the prevalence of A. cantonensisand abundance of the latter was negatively related to rainfall. The overall prevalence of A. cantonensisin B. similariswas 24.6%. A. fulicawas the most important intermediary host of A. cantonensisin the studied area andB. similariswas secondary in importance for A. cantonensistransmission dynamics.

  11. 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.

  12. Terrestrial mollusc records from Xifeng and Luochuan L9 loess strata and their implications for paleoclimatic evolution in the Chinese Loess Plateau during marine Oxygen Isotope Stages 24-22

    Directory of Open Access Journals (Sweden)

    B. Wu

    2011-04-01

    Full Text Available Marine Isotope Stages 24-22 is a key period of the Mid-Pleistocene Transition, however, its climate variability is still unclear. The coarse-grained loess unit L9, one of the most prominent units in the Chinese loess stratigraphy, yields a high potential terrestrial record of paleoclimatic and paleoenvironmental changes during this period. In this study, two high-resolution terrestrial mollusc records of L9 loess strata from the Xifeng and Luochuan sequences in the Chinese Loess Plateau were analysed. Our mollusc results show that the MIS 24, the early and late parts of MIS 22 were dominated by cold and dry climate. Relatively mild-humid climate occurred in MIS 23 and the middle part of MIS 22. The climatic conditions at Xifeng region were cooler and more unstable compared to Luochuan region. A comparison of mollusc species composition and other proxies of L9 strata (MIS 24-22 with those of L1 loess units (MIS 4-2 indicates that the L9 loess was not deposited under the most severe glacial conditions in Quaternary climate history as suggested in previous studies. Our study shows that climatic conditions in the Loess Plateau during the L9 loess forming period were similar to that of gentle glacials (MIS 24 and MIS 22 and interglacial (MIS 23, as suggested by the marine δ18O record. Three cooling fluctuations occurred at ~930 ka, 900 ka and 880 ka, which might hint to the global "900 ka cooling event". The "900-ka event" in the Loess Plateau does not seem to be a simple long glaciation, but rather several complex climatic fluctuations superposed on a general cooling trend. The uplift of the Tibetan Plateau and the general cooling experienced by the Earth during this period may have resulted in abundant dust sources and increased dust transport capability, as indicated by increased grain size and the mass accumulation rate of L9 loess.

  13. The importance of terrestrial carbon in supporting molluscs in the wetlands of Poyang Lake

    Science.gov (United States)

    Zhang, Huan; Yu, Xiubo; Wang, Yuyu; Xu, Jun

    2017-07-01

    Allochthonous organic matter plays an important role in nutrient cycling and energy mobilization in freshwater ecosystems. However, the subsidies of this carbon source in floodplain ecosystems have not yet well understood. We used a Bayesian mixing model and stable isotopes (δ13C and δ15N) of primary food resources and dominant molluscs species, to estimate the relative importance of allochthonous carbon sources for consumers in a representative sub-lake of Poyang Lake during a prolonged dry season. Our study inferred that terrestrial-derived carbon from Carex spp. could be the primary contributor to snails and mussels in Dahuchi Lake. The mean percentage of allochthonous food resources accounted for 35%-50% of the C incorporated by these consumers. Seston was another important energy sources for benthic consumers. However, during the winter and low water-level period, benthic algae and submerged vegetation contributed less carbon to benthic consumers. Our data highlighted the importance of terrestrial organic carbon to benthic consumers in the wetlands of Poyang Lake during the prolonged dry period. Further, our results provided a perspective that linkages between terrestrial and aquatic ecosystems might be facilitated by wintering geese via their droppings.

  14. Shaping mechanisms of metal specificity in a family of metazoan metallothioneins: evolutionary differentiation of mollusc metallothioneins

    Directory of Open Access Journals (Sweden)

    Atrian Sílvia

    2011-01-01

    Full Text Available Abstract Background The degree of metal binding specificity in metalloproteins such as metallothioneins (MTs can be crucial for their functional accuracy. Unlike most other animal species, pulmonate molluscs possess homometallic MT isoforms loaded with Cu+ or Cd2+. They have, so far, been obtained as native metal-MT complexes from snail tissues, where they are involved in the metabolism of the metal ion species bound to the respective isoform. However, it has not as yet been discerned if their specific metal occupation is the result of a rigid control of metal availability, or isoform expression programming in the hosting tissues or of structural differences of the respective peptides determining the coordinative options for the different metal ions. In this study, the Roman snail (Helix pomatia Cu-loaded and Cd-loaded isoforms (HpCuMT and HpCdMT were used as model molecules in order to elucidate the biochemical and evolutionary mechanisms permitting pulmonate MTs to achieve specificity for their cognate metal ion. Results HpCuMT and HpCdMT were recombinantly synthesized in the presence of Cd2+, Zn2+ or Cu2+ and corresponding metal complexes analysed by electrospray mass spectrometry and circular dichroism (CD and ultra violet-visible (UV-Vis spectrophotometry. Both MT isoforms were only able to form unique, homometallic and stable complexes (Cd6-HpCdMT and Cu12-HpCuMT with their cognate metal ions. Yeast complementation assays demonstrated that the two isoforms assumed metal-specific functions, in agreement with their binding preferences, in heterologous eukaryotic environments. In the snail organism, the functional metal specificity of HpCdMT and HpCuMT was contributed by metal-specific transcription programming and cell-specific expression. Sequence elucidation and phylogenetic analysis of MT isoforms from a number of snail species revealed that they possess an unspecific and two metal-specific MT isoforms, whose metal specificity was

  15. Angiostrongylus cantonensis infection in molluscs in the municipality of São Gonçalo, a metropolitan area of Rio de Janeiro, Brazil: role of the invasive species Achatina fulica in parasite transmission dynamics.

    Science.gov (United States)

    Oliveira, Ana P M; Gentile, Rosana; Maldonado Júnior, Arnaldo; Lopes Torres, Eduardo J; Thiengo, Silvana C

    2015-09-01

    The aim of this study was to analyse the infection dynamics of Angiostrongylus cantonensisin its possible intermediate hosts over two years in an urban area in the state of Rio de Janeiro where the presence ofA. cantonensis had been previously recorded in molluscs. Four of the seven mollusc species found in the study were exotic.Bradybaena similaris was the most abundant, followed by Achatina fulica, Streptaxis sp., Subulina octona, Bulimulus tenuissimus, Sarasinula linguaeformis and Leptinaria unilamellata. Only A. fulica and B. similaris were parasitised by A. cantonensis and both presented co-infection with other helminths. The prevalence of A. cantonensis in A. fulica was more than 50% throughout the study. There was an inverse correlation between the population size ofA. fulica and the prevalence of A. cantonensis and abundance of the latter was negatively related to rainfall. The overall prevalence of A. cantonensis in B. similaris was 24.6%. A. fulica was the most important intermediary host of A. cantonensis in the studied area and B. similaris was secondary in importance for A. cantonensis transmission dynamics.

  16. Assessment of arsenic in coastal sediments, seawaters and molluscs in the Tarut Island, Arabian Gulf, Saudi Arabia

    Science.gov (United States)

    El-Sorogy, Abdelbaset S.; Youssef, Mohamed; Al-Kahtany, Khaled; Al-Otaiby, Naif

    2016-01-01

    In order to assess arsenic on the Tarut coast, Saudi Arabian Gulf, 38 sediment samples, 26 seawater samples and 40 gastropod and bivalve specimens were collected for analyses by Inductively Coupled Plasma-Mass Spectrometer. The Enrichment Factor (EF), the Geoaccumulation Index (Igeo) and the Contamination Factor (CF) indicated that coastal sediments of Tarut Island are severely enriched, strongly polluted and very highly contaminated with arsenic as a result of anthropogenic inputs. Comparison with arsenic in coastal sediments, seawaters and molluscs in the Red Sea, the Arabian Gulf and abroad coasts suggested that the studied samples have higher concentrations of As. The suggested natural sources of arsenic in the study area are the weathering and decomposition of neighboring deserts. The anthropogenic sources include the land reclamation, petrochemical industries, boat exhaust emissions, oil leakage, desalination plants and sewage effluents. These anthropogenic sources are the dominant sources of As in the study area and mostly came from Al Jubail industrial city to the north.

  17. Development and application of the mollusc Arctica islandica as a paleoceanographic tool for the North Atlantic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Weidman, C.R.

    1995-09-01

    Until now there has been no tool comparable to corals for reconstructing long term high-resolution geochemical time-series for the colder, higher-latitude oceans. In this thesis, the long-lived (+100 years) boreal mollusc (Bivalvia) Arctica islandica is shown to be practical for this purpose in the northern North Atlantic Ocean. The evidence, compiled here, demonstrates that the carbonate shell of this species faithfully records the ambient dissolved inorganic carbon`s (DIC) radiocarbon ({Delta}{sup 14}C) concentration and accurately reflects the ambient temperature in its stable oxygen isotope ({delta}{sup 18}O) composition. However, the stable carbon isotope ({delta}{sup 13}C) composition of the A. islandica shell likely is not a good recorder of ambient DIC {delta}{sup 13}C, and likely responds to physiological controls. Four {Delta}{sup 14}C time histories are reconstructed from the annual bands of A. islandica shells for the higher-latitudes of the northern North Atlantic Ocean (from 41{degree}N to 70{degree}N).

  18. Structure and seasonality in a Malaysian mudflat community

    Science.gov (United States)

    Broom, M. J.

    1982-08-01

    An assessment of community composition and the functional roles of the dominant species has been carried out in two intertidal areas of Malaysian mudflat dominated by natural populations of the arcid bivalve mollusc Anadara granosa. In addition to A. granosa, organisms of numerical importance are the venerid bivalve Pelecyora trigona, the neogastropod Plicarcularia leptospira, the mesogastropods Stenothyra glabrata and Cerithidea cingulata and the hermit crab Diogenes sp. The mesogastropod Natica maculosa and the neogastropod Thais carinifera may be of some importance to community organization but they are not numerically dominant. Annelids are conspicuous by their absence. The following trophic roles are ascribed to specific members of the community: A. granosa—facultative surface deposit feeder; P. trigona—suspension feeder; P. leptospira—scavenger; C. cingulata—deposit feeder/grazer; S. glabrata—deposit feeder/grazer; N. maculosa—predator; T. carinifera—predator; Diogenes sp.—scavenger/predator. S. glabrata is of particular interest because it appears to fill the niche occupied by mud snails of the genus Hydrobia in temperate mudflat systems. There is evidence of seasonality on the mudflats which points to a spawning of certain forms triggered by the major annual salinity depression at the time of the onset of the north-east monsoon in October/November. Concentrations of benthic chlorophyll a show no obvious signs of a seasonal fluctuation and the seasonality of the primary consumers is not thought to be related to food abundance. However there is some evidence of seasonality of reproduction in N. maculosa which preys on the seasonally reproducing bivalves.

  19. Oxygen consumption and responses of the freshwater snail Bulinus ...

    African Journals Online (AJOL)

    behaviour to oxygen differences in the water is of special interest. Knowledge of this ... fold, the prosobranch, to enhance the gaseous exchange between the animal ..... meins that little stress on the respiration ability was encountered towards ...

  20. Mollusc life and death assemblages on a tropical rocky shore as proxies for the taphonomic loss in a fossil counterpart

    DEFF Research Database (Denmark)

    Sørensen, Anne Mehlin; Surlyk, Finn

    2013-01-01

    a lower taxonomic agreement to the death assemblage than found in previous published studies. Rocky shore life and death assemblages thus appear to show lower taxonomic agreement compared to muddy or sandy shelf assemblages due to the mix after death with the sandy beach assemblage. A hypothetical fossil......Comparison of a modern rocky shore mollusc life assemblage from Thailand with the associated death assemblage, and interpretation of the fossilization potential of the latter, are used to investigate the fidelity in reconstruction of ancient analogues. The fauna from the death assemblage represents...... species from the rocky shore and the associated sandy pocket beaches, and only a few exotic species from other, completely different habitats are present. The environmental fidelity between the life and death assemblage is thus high, with the majority of species from the death assemblage representing...

  1. Cryptomphalus aspersa Mollusc Egg Extract Promotes Regenerative Effects in Human Dermal Papilla Stem Cells

    Directory of Open Access Journals (Sweden)

    María Teresa Alameda

    2017-02-01

    Full Text Available The aim of this study was to test, by an in vitro approach, whether a natural extract derived from eggs of the mollusc Cryptomphalus aspersa (e-CAF that seems to present regenerative properties, can enhance the mobilization of human hair dermal papilla cells (HHDPCs and play a role on tissue repair and regeneration. We have tested HHDPCs proliferation by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium-bromide (MTT assay; cell migration by using a wound healing assay, as well as the modulation of the expression of cytoskeletal (F-actin and vimentin and cell adhesion to the extracellular matrix (ECM (vinculin and P-FAK proteins. We also explored whether e-CAF could lead HHDPCs to keratinocytes and/or fibroblasts by evaluating the expression of specific markers. We have compared these e-CAF effects with those induced by TGFβ1, implicated in regulation of cell proliferation and migration. e-CAF promotes proliferation and migration of HDDPCs cells in a time- and dose-dependent manner; it also increases the migratory behavior and the expression of adhesion molecules. These results support the fact that e-CAF could play a role on skin regeneration and be used for the prevention or repair of damaged tissue, either due to external causes or as a result of cutaneous aging.

  2. Testing cosmic dose rate models for ESR: Dating corals and molluscs on San Salvador, Bahamas

    International Nuclear Information System (INIS)

    Deely, A.E.; Blackwell, B.A.B.; Mylroie, J.E.; Carew, J.L.; Blickstein, J.I.B.; Skinner, A.R.

    2011-01-01

    Sealevel curves are best developed on tectonically stable coastlines, like San Salvador, where eolianites preserve transgressive and regressive phases associated with Quaternary high seastands, while reef facies mark the highstands. At 11 locations around San Salvador, terrestrial molluscs (Cerion) from the eolianites, lagoonal bivalves (Codakia), and corals from the highstand deposits were dated by ESR. Volumetrically averaged sedimentary dose rates were calculated from sedimentary geochemistry and time-averaged cosmic dose rates from each sample's current and past geologic contexts. Rice Bay Formation corals dated at 3.9 ± 0.3 to 7.1 ± 0.4 ka (OIS 1). Minimum ages for the Cockburn Town Member's regressive phase ranged from 49 ± 6 to 75 ± 8 ka, correlating with OIS 3-4. Codakia dates showed that an OIS 5a sealevel approached modern levels at 91-78 ka. In situ corals from the Cockburn Town Reef averaged from 127 ± 6 to 138 ± 10 ka, correlating well with OIS 5e. Ages from the Reef's rubble zones hint that some coral reefs grew as early as OIS 7, but were likely reworked during OIS 5. San Salvador preserves deposits from three mid to late Quaternary highstands above, and as many as three that closely approach, modern sealevel.

  3. Testing cosmic dose rate models for ESR: Dating corals and molluscs on San Salvador, Bahamas

    Energy Technology Data Exchange (ETDEWEB)

    Deely, A.E. [RFK Science Research Institute, Glenwood Landing, NY, 11547-0866 (United States); Blackwell, B.A.B., E-mail: bonnie.a.b.blackwell@williams.edu [RFK Science Research Institute, Glenwood Landing, NY, 11547-0866 (United States); Dept. of Chemistry, Williams College, Williamstown MA, 01267-2692 (United States); Mylroie, J.E. [Dept. of Geosciences, Mississippi State University, MS, 39762-5448 (United States); Carew, J.L. [Dept. of Geology and Environmental Geosciences, College of Charleston, Charleston, SC 29424 (United States); Blickstein, J.I.B. [RFK Science Research Institute, Glenwood Landing, NY, 11547-0866 (United States); Skinner, A.R. [RFK Science Research Institute, Glenwood Landing, NY, 11547-0866 (United States); Dept. of Chemistry, Williams College, Williamstown MA, 01267-2692 (United States)

    2011-09-15

    Sealevel curves are best developed on tectonically stable coastlines, like San Salvador, where eolianites preserve transgressive and regressive phases associated with Quaternary high seastands, while reef facies mark the highstands. At 11 locations around San Salvador, terrestrial molluscs (Cerion) from the eolianites, lagoonal bivalves (Codakia), and corals from the highstand deposits were dated by ESR. Volumetrically averaged sedimentary dose rates were calculated from sedimentary geochemistry and time-averaged cosmic dose rates from each sample's current and past geologic contexts. Rice Bay Formation corals dated at 3.9 {+-} 0.3 to 7.1 {+-} 0.4 ka (OIS 1). Minimum ages for the Cockburn Town Member's regressive phase ranged from 49 {+-} 6 to 75 {+-} 8 ka, correlating with OIS 3-4. Codakia dates showed that an OIS 5a sealevel approached modern levels at 91-78 ka. In situ corals from the Cockburn Town Reef averaged from 127 {+-} 6 to 138 {+-} 10 ka, correlating well with OIS 5e. Ages from the Reef's rubble zones hint that some coral reefs grew as early as OIS 7, but were likely reworked during OIS 5. San Salvador preserves deposits from three mid to late Quaternary highstands above, and as many as three that closely approach, modern sealevel.

  4. Macroevolutionary consequences of profound climate change on niche evolution in marine molluscs over the past three million years

    Science.gov (United States)

    Saupe, E.E.; Hendricks, J.R.; Portell, R.W.; Dowsett, Harry J.; Haywood, A. M.; Hunter, S.J.; Lieberman, B.S.

    2014-01-01

    In order to predict the fate of biodiversity in a rapidly changing world, we must first understand how species adapt to new environmental conditions. The long-term evolutionary dynamics of species' physiological tolerances to differing climatic regimes remain obscure. Here, we unite palaeontological and neontological data to analyse whether species' environmental tolerances remain stable across 3 Myr of profound climatic changes using 10 phylogenetically, ecologically and developmentally diverse mollusc species from the Atlantic and Gulf Coastal Plains, USA. We additionally investigate whether these species' upper and lower thermal tolerances are constrained across this interval. We find that these species' environmental preferences are stable across the duration of their lifetimes, even when faced with significant environmental perturbations. The results suggest that species will respond to current and future warming either by altering distributions to track suitable habitat or, if the pace of change is too rapid, by going extinct. Our findings also support methods that project species' present-day environmental requirements to future climatic landscapes to assess conservation risks.

  5. Models for positional signalling, the threefold subdivision of segments and the pigmentation pattern of molluscs.

    Science.gov (United States)

    Meinhardt, H

    1984-11-01

    Models of biological pattern formation are discussed. The regulatory features expected from the models are compared to those observed experimentally. It will be shown that: (i) Stable gradients appropriate to supply positional information can be produced by local autocatalysis and long-range inhibition. (ii) Spatially ordered sequences of differentiated cell states can emerge if these cell states mutually activate each other on long range but exclude each other locally. Segmentation results from the repetition of three such cell states, S, A and P (and not of only two, as is usually assumed). With a repetition of three states, each segment has a defined polarity. The confrontation of P cells and S cells lead to the formation of a segment border (...P/SAP/SAP/S...) while the A-P confrontation is a prerequisite for appendage formation. Mutations of Drosophila affecting larval segmentation are discussed in terms of this model. (iii) The two models for the generation of sequences of structures in space (positional information including interpretation versus mutual activation) lead to different predictions with respect to intercalary regeneration. This allows a distinction between the two models on the basis of experiments. (iv) The pigmentation patterns of certain molluscs emerge from a coupled oscillation of cells (that is, a lateral inhibition in time, instead of space). The oblique lines result from a chain of triggering events.

  6. Microplastics contamination in molluscs from the northern part of the Persian Gulf.

    Science.gov (United States)

    Naji, Abolfazl; Nuri, Marzieh; Vethaak, A Dick

    2018-04-01

    Microplastics (MPs) are well-known emerging contaminants in the marine environment. A key route by which MPs can directly affect marine life is through ingestion. The objective of the present study was to evaluate the occurrence of MPs in marine life and seafood for human consumption in the Persian Gulf. We conducted a whole body analysis of MP (between 10 and 5000 μm in diameter) abundance in five species of molluscs with different feeding strategies, including both gastropods and bivalves from the littoral zone of the Iranian coast of the Persian Gulf. The mean number of total encountered MPs in all species ranged from 0.2 to 21.0 particles per g of soft tissue (wet weight) and from 3.7 to 17.7 particles per individual. Overall, microfibres followed by fragments were the most common type of MP isolated in each species (respectively > 50% and ≈26%). Film (≈14%) and pellets (≈2%) were less commonly observed. The observed MPs were classified into three size groups (ca. 10-25 μm, 25-250 μm and 250-5000 μm), and 37-58% of MPs fell into the smallest size group. Fourier transform infrared (FT-IR) analysis confirmed the presence of polyethylene (PE), polyethylene terephthalate (PET), and nylon (PA). Our results indicated that molluscan shellfish from the Persian Gulf contain MPs, with higher concentrations in a predatory species, suggesting trophic transfer of MPs in the food web. The consumption of edible species may be a source of human microplastic intake. We compared our results with those previously reported for other regions of the world and identified the need for further studies in the Persian Gulf. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Volatile and bioactive compounds in opercula from Muricidae molluscs supports their use in ceremonial incense and traditional medicines.

    Science.gov (United States)

    Nongmaithem, Bijayalakshmi Devi; Mouatt, Peter; Smith, Joshua; Rudd, David; Russell, Michael; Sullivan, Caroline; Benkendorff, Kirsten

    2017-12-12

    Muricidae molluscs are the source of a valuable purple dye that was traded as a luxury item in the Mediterranean region and by the late Byzantine was reserved for royalty and priests. Less well known is the use of muricid opercula in sacred incense and traditional medicines, although they are still used as rare ingredients today. This study provides the first chemical assessment of opercula from Muricidae, based on several traditional preparation procedures. Chemical analysis of opercula smoke revealed aromatic phenols, which act as fragrance stabilisers and produce a "medicinal" odour. Analysis of lipid extracts revealed pharmaceutically active compounds, including brominated indoles, choline esters and adenosine, consistent with their traditional medical applications. Depending on the preparation procedures, toxic pyridine was also detected. ICP-MS analysis of muricid opercula shows the presence of essential macro and microelements, as well as metals, some of which exceed the recommended safe levels for human use. Nevertheless, these findings support the Muricidae as an historically important marine resource, providing Biblical dyes, medicines and perfume. The opercula contains biologically active compounds and produces smoke containing volatile scent compounds, consistent with their identification as the most likely source of onycha, a controversial ingredient in sacred incense.

  8. Comparative mapping of GABA-immunoreactive neurons in the central nervous systems of nudibranch molluscs.

    Science.gov (United States)

    Gunaratne, Charuni A; Sakurai, Akira; Katz, Paul S

    2014-03-01

    The relative simplicity of certain invertebrate nervous systems, such as those of gastropod molluscs, allows behaviors to be dissected at the level of small neural circuits composed of individually identifiable neurons. Elucidating the neurotransmitter phenotype of neurons in neural circuits is important for understanding how those neural circuits function. In this study, we examined the distribution of γ-aminobutyric-acid;-immunoreactive (GABA-ir) neurons in four species of sea slugs (Mollusca, Gastropoda, Opisthobranchia, Nudibranchia): Tritonia diomedea, Melibe leonina, Dendronotus iris, and Hermissenda crassicornis. We found consistent patterns of GABA immunoreactivity in the pedal and cerebral-pleural ganglia across species. In particular, there were bilateral clusters in the lateral and medial regions of the dorsal surface of the cerebral ganglia as well as a cluster on the ventral surface of the pedal ganglia. There were also individual GABA-ir neurons that were recognizable across species. The invariant presence of these individual neurons and clusters suggests that they are homologous, although there were interspecies differences in the numbers of neurons in the clusters. The GABAergic system was largely restricted to the central nervous system, with the majority of axons confined to ganglionic connectives and commissures, suggesting a central, integrative role for GABA. GABA was a candidate inhibitory neurotransmitter for neurons in central pattern generator (CPG) circuits underlying swimming behaviors in these species, however none of the known swim CPG neurons were GABA-ir. Although the functions of these GABA-ir neurons are not known, it is clear that their presence has been strongly conserved across nudibranchs. Copyright © 2013 Wiley Periodicals, Inc.

  9. Bioaccumulation of Iron and Lead in the soft tissue of some marine molluscs and associated sediment at labor Island,Aden,yemen

    International Nuclear Information System (INIS)

    Ali, Anis Ahmed; Baharoon Aqil Abdulrahman

    2000-01-01

    The aim of this research work is to know the effect of the oil spill from the oil pipes that pass near the Labor Island, in addition the use of the Island as a station for gathering the old ships and boats that been prepared for re-exportation. For this purpose, a number of marine molluscs were used such as, A canthopleura haddoni (chitons), Ostrea cucullata (oysters), Turbo coronatus (sea snails). The were classified to their classes and sizes. Associated surfacial sediments were also used after sieving to <63 μm, in order to be analyzed by using the AAS. The results obtained showed high concentration in Fe and Pb in the soft tissue of the marine animals used and the associated sediment. These results indicate that these two heavy metals were bioaccumulated, and this accumulation may be returned to the oil spill from the oil pipes, or to the spill of drainage from the Iron mountain camp, or all the probabilities together. (author)

  10. Molluscs and echinoderms aquaculture: biological aspects, current status, technical progress and future perspectives for the most promising species in Italy

    Directory of Open Access Journals (Sweden)

    Antonio Pais

    2012-10-01

    Full Text Available Shellfish aquaculture is a widespread activity in the Italian peninsula. However, only two bivalve species are mainly cultured along the coastline of that country: the Mediterranean mussel Mytilus galloprovincialis and the Manila clam Venerupis philippinarum (Ruditapes philippinarum. By contrast, just a few other mollusc species of commercial interest are scarcely reared at a small-scale level. After analysing the current status of Italian shellfish production, this paper reports and discusses the potential for culturing several different invertebrate species [i.e., the European flat oyster Ostrea edulis, the grooved carpet shell Venerupis decussata (Ruditapes decussatus, the razor clams Ensis minor and Solen marginatus, the cephalopod Octopus vulgaris, and the purple sea urchin Paracentrotus lividus] in this country. In addition, a detailed overview of the progress made in aquacultural techniques for these species in the Mediterranean basin is presented, highlighting the most relevant bottlenecks and the way forward to shift from the experimental to the aquaculture phase. Finally, an outlook of the main economic and environmental benefits arising from these shellfish culture practices is also given.

  11. Stationary and non-stationary occurrences of miniature end plate potentials are well described as stationary and non-stationary Poisson processes in the mollusc Navanax inermis.

    Science.gov (United States)

    Cappell, M S; Spray, D C; Bennett, M V

    1988-06-28

    Protractor muscles in the gastropod mollusc Navanax inermis exhibit typical spontaneous miniature end plate potentials with mean amplitude 1.71 +/- 1.19 (standard deviation) mV. The evoked end plate potential is quantized, with a quantum equal to the miniature end plate potential amplitude. When their rate is stationary, occurrence of miniature end plate potentials is a random, Poisson process. When non-stationary, spontaneous miniature end plate potential occurrence is a non-stationary Poisson process, a Poisson process with the mean frequency changing with time. This extends the random Poisson model for miniature end plate potentials to the frequently observed non-stationary occurrence. Reported deviations from a Poisson process can sometimes be accounted for by the non-stationary Poisson process and more complex models, such as clustered release, are not always needed.

  12. An illustrated catalogue of Rudolf Sturany’s type specimens in the Naturhistorisches Museum Wien, Austria (NHMW: deep-sea Eastern Mediterranean molluscs

    Directory of Open Access Journals (Sweden)

    Paolo G. Albano

    2018-01-01

    Full Text Available The “Pola” expeditions were the first to explore the deep Eastern Mediterranean Sea in the 1890s. They remained the most intense surveys in that area for a century and constitute today a fundamental baseline to assess change in the basin, whose fauna is still inadequately described. Solid taxonomic foundations for the study of deep-sea organisms are needed and we here contribute by revising the name-bearing types of mollusc species introduced by Rudolf Sturany on the basis of the “Pola” material from the Eastern Mediterranean Sea stored in the Natural History Museum in Vienna. Sturany introduced 15 names (Marginella occulta var. minor Sturany, 1896 shall not be considered as the introduction of a new name. He described and established two manuscript names by Monterosato: Jujubinus igneus and Pseudomurex ruderatus. The genus Isorropodon was also introduced together with its type species I. perplexum. For each name, we list the available type material, provide the original description and a translation into English and illustrate the specimens in colour and with SEM imaging.

  13. Investigation and measurement of radio thermoluminescence properties of some calci tic mollusc shells of the Persian Gulf and the Oman Sea (for γ radiation dosimetry)

    International Nuclear Information System (INIS)

    Ghafourian, H.; Rabbani, M.; Rouhi, U.

    2000-01-01

    Biogenic Calcium Carbonate, particularly as naturally thermoluminescent calci tic mollusc shells may serve as excellent radio thermoluminescent dosimeters. In this study the radio thermoluminescence properties of 8 different bivalves of the Persian Gulf, the Oman Sea and the internal calcite shell of Sepia sp. are investigated. The results of this investigation have shown that the shells of Sepia sp., Pinctata radiata and Card ita bicolor as appropriate dosimeters for both personal and industrial dosimetry purposes, among which Sepia sp. is the most sensitive one. Callista umbonella and Mactra sp. are relatively less thermoluminescent while Saccostrea Cucullata and Chlamys ruschenbergerii are completely inert with respect to γ - thermoluminescence. Thermoluminescence properties of Anadara refescens and Anadara secticostata decrease surprisingly by an increase in the absorbed dose of γ radiation, which can mainly be interpreted as the result of crystal lattice destruction caused by ionizing radiation

  14. Molluscs of an intertidal soft-sediment area in China: Does overfishing explain a high density but low diversity community that benefits staging shorebirds?

    Science.gov (United States)

    Yang, Hong-Yan; Chen, Bing; Piersma, Theunis; Zhang, Zhengwang; Ding, Changqing

    2016-03-01

    The Yellow Sea is a key staging ground for shorebirds that migrate from Australasia to the Arctic each spring. A lot of attention has been paid to the impact of habitat loss due to land reclamation on shorebird survival, but any effects of overfishing of coastal resources are unclear. In this study, the abundance of molluscs in the intertidal mudflats of northern Bohai Bay on the Chinese Yellow Sea was investigated in 2008-2014 from the perspective of their importance as food for northward migrating shorebirds, especially Red Knots Calidris canutus. Numerically contributing 96% to the numbers of 17 species found in spring 2008, the bivalve Potamocorbula laevis (the staple food of Red Knots and other shorebirds) dominated the intertidal mollusc community. In the spring of 2008-2014, the densities of P. laevis were surprisingly high, varying between 3900 and 41,000 individuals/m2 at distinctly small sizes (average shell lengths of 1.1 to 4.8 mm), and thus reaching some of the highest densities of marine bivalves recorded worldwide and providing good food for shorebirds. The distribution of P. laevis was associated with relatively soft sediments in close proximity to the recently built seawalls. A monthly sampling programme showed steep seasonal changes in abundance and size. P. laevis were nearly absent in winter, each year settling on the intertidal mudflats anew. Peak densities were reached in spring, when 0-age P. laevis were 1-3 mm long. The findings point to a highly unusual demographic structure of the species, suggesting that some interfering factors are at play. We hypothesise that the current dominance of young P. laevis in Bohai Bay reflects the combined pressures of a nearly complete active removal of adult populations from mid-summer to autumn for shrimp farming (this clearing of adults may offer space for recruitment during the next spring) and low numbers of epibenthic predators of bivalves, such as shrimps and crabs, due to persistent overfishing in

  15. Quaternary ostracodes and molluscs from the Rukwa Basin (Tanzania) and their evolutionary and paleobiogeographic implications

    Science.gov (United States)

    Cohen, Andrew S.; Van Bocxlaer, Bert; Todd, Jonathan A.; McGlue, Michael; Michel, Ellinor; Nkotagu, Hudson H.; Grove, A.T.; Delvaux, Damien

    2013-01-01

    Much of the spectacular biodiversity of the African Great Lakes is endemic to single lake basins so that the margins of these basins or their lakes coincide with biogeographic boundaries. Longstanding debate surrounds the evolution of these endemic species, the stability of bioprovinces, and the exchange of faunas between them over geologic time as the rift developed. Because these debates are currently unsettled, we are uncertain of how much existing distribution patterns are determined by modern hydrological barriers versus reflecting past history. This study reports on late Quaternary fossils from the Rukwa Basin and integrates geological and paleoecological data to explore faunal exchange between freshwater bioprovinces, in particular with Lake Tanganyika. Lake Rukwa's water level showed large fluctuations over the last 25 ky, and for most of this period the lake contained large habitat diversity, with different species assemblages and taphonomic controls along its northern and southern shores. Comparison of fossil and modern invertebrate assemblages suggests faunal persistence through the Last Glacial Maximum, but with an extirpation event that occurred in the last 5 ky. Some of the molluscs and ostracodes studied here are closely related to taxa (or part of clades) that are currently endemic to Lake Tanganyika, but others testify to wider and perhaps older faunal exchanges between the Rukwa bioprovince and those of Lake Malawi and the Upper Congo (in particular Lake Mweru). The Rukwa Basin has a long history of rifting and lacustrine conditions and, at least temporarily, its ecosystems appear to have functioned as satellites to Lake Tanganyika in which intralacustrine speciation occurred. Paleontological studies of the Rukwa faunas are particularly relevant because of the basin's important role in the late Cenozoic biogeography of tropical Africa, and because many of the molecular traces potentially revealing this history would have been erased in the late

  16. Proton nuclear magnetic resonance study of the ferrous derivatives of the dimeric and tetrameric hemoglobin from the mollusc Scapharca inaequivalvis

    International Nuclear Information System (INIS)

    Inubushi, Toshiero; Yonetani, Takahashi; Chiancone, E.; Univ. 'La Sapienza', Rome

    1988-01-01

    Proton NMR spectra have been measured for the two hemoglobins from the mollusc Scapharca inaequivalvis: HbI, a homodimer, and HbII, a heterotetramer. These hemoglobins are endowed with a unique subunit assembly, since the heme carrying E and F helices are involved in the major intersubunit contact. In the far-downfield region of hyperfine-shifted resonances the spectra of HbI and HbII in the deoxy state show respectively one (66.7 ppm) and two (67.8 and 63.6 ppm) exchangeable signals of the proximal histidine N/sub delta/H groups, the resonance position being indicative of a significant strain in the iron-imidazole interaction. In the hydrogen-bonded proton region, inter-and intrasubunit hydrogen-bonded proton signals have been detected for both hemoglobins. Deoxy-HbI shows two unique downfied resonances at 11.83 and 11.51 ppm which disappear in the oxygenated state, suggesting that the corresponding hydrogen bonds are iinvolved in the stabilization of the tertiary and/or quaternary structure of the deoxy form. HbII shows even smaller changes in this region upon changes in ligation state. These results therefore provide further proof that, at variance with the vertebrate hemoglobin tetramer, the unique subunit assembly of these proteins is stabilized mainly by hydrophobic interactions

  17. Molecular and Biochemical Methods Useful for the Epigenetic Characterization of Chromatin-Associated Proteins in Bivalve Molluscs

    Directory of Open Access Journals (Sweden)

    Ciro Rivera-Casas

    2017-08-01

    Full Text Available Bivalve molluscs constitute a ubiquitous taxonomic group playing key functions in virtually all ecosystems, and encompassing critical commercial relevance. Along with a sessile and filter-feeding lifestyle in most cases, these characteristics make bivalves model sentinel organisms routinely used for environmental monitoring studies in aquatic habitats. The study of epigenetic mechanisms linking environmental exposure and specific physiological responses (i.e., environmental epigenetics stands out as a very innovative monitoring strategy, given the role of epigenetic modifications in acclimatization and adaptation. Furthermore, the heritable nature of many of those modifications constitutes a very promising avenue to explore the applicability of epigenetic conditioning and selection in management and restoration strategies. Chromatin provides a framework for the study of environmental epigenetic responses. Unfortunately, chromatin and epigenetic information are very limited in most non-traditional model organisms and even completely lacking in most environmentally and ecologically relevant organisms. The present work aims to provide a comprehensive and reproducible experimental workflow for the study of bivalve chromatin. First, a series of guidelines for the molecular isolation of genes encoding chromatin-associated proteins is provided, including information on primers suitable for conventional PCR, Rapid Amplification of cDNA Ends (RACE, genome walking and quantitative PCR (qPCR experiments. This section is followed by the description of methods specifically developed for the analysis of histone and SNBP proteins in different bivalve tissues, including protein extraction, purification, separation and immunodetection. Lastly, information about available antibodies, their specificity and performance is also provided. The tools and protocols described here complement current epigenetic analyses (usually limited to DNA methylation by incorporating

  18. Eutrophication and Dreissena invasion as drivers of biodiversity: a century of change in the mollusc community of Oneida Lake.

    Directory of Open Access Journals (Sweden)

    Vadim A Karatayev

    Full Text Available Changes in nutrient loading and invasive species are among the strongest human-driven disturbances in freshwater ecosystems, but our knowledge on how they affect the biodiversity of lakes is still limited. We conducted a detailed historical analysis of the mollusc community of Oneida Lake based on our comprehensive lakewide study in 2012 and previous surveys dating back to 1915. In the early 20th century, the lake had a high water clarity, with abundant macrophytes and benthic algae, and hosted the most diverse molluscan community in New York State, including 32 gastropod and 9 unionid species. By the 1960s, lake turbidity increased during a period of anthropogenic eutrophication, resulting in a 38% decline in species richness and a 95% reduction in abundance of native gastropods grazing on benthic algae. Following the invasion of Dreissena spp. in 1991 and subsequent increases in water clarity, native gastropod species richness expanded by 37% and abundance increased 20-fold by 2012. In contrast, filter-feeding unionids were unaffected by increased turbidity during the period of eutrophication but were extirpated by dreissenids. Through contrasting effects on turbidity, eutrophication and Dreissena spp. have likely driven the observed changes in native grazing gastropods by affecting the abundance of light-limited benthic algae. Given the high species richness and ecological importance of benthic grazers, monitoring and managing turbidity is important in preserving molluscan diversity.

  19. Structure and density population of the invasive mollusc Limnoperna fortunei associated with Eichhornia crassipes in lakes of the Middle Paraná floodplain

    Directory of Open Access Journals (Sweden)

    Gabriela E. Musin

    2015-04-01

    Full Text Available The roots of Eichhornia crassipes provide different microhabitats for invertebrates, including substrate for the Asian invasive bivalve Limnoperna fortunei. This work evaluated the density and size structure of L. fortunei on the roots of E. crassipes in lentic waterbodies associated with the Middle Paraná floodplain. The field work was carried out between November 2009–2010, covering different phases of the hydrological regime. Floating meadows of E. crassipes were sampled monthly in two lakes with different degrees of connection to the main channel of the Paraná River. Bivalve densities were not associated with variations of the biomass of E. crassipes roots and the highest mussel densities were recorded during months of high temperature. The maximum size recorded in both lakes corresponded to individuals approximately 2.5 years old; however, up to 75% of the molluscs were represented by pre-reproductive individuals (up to 6 months old. In these lakes with soft bottom and limited hard substrates, E. crassipes is an important site for the mussel attachment during its early stages of development and could not be the final site of settlement during its lifecycle.

  20. 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

  1. Impact of toxic cyanobacteria on gastropods and microcystin accumulation in a eutrophic lake (Grand-Lieu, France) with special reference to Physa (= Physella) acuta

    International Nuclear Information System (INIS)

    Lance, Emilie; Brient, Luc; Carpentier, Alexandre; Acou, Anthony; Marion, Loic; Bormans, Myriam; Gerard, Claudia

    2010-01-01

    Hepatotoxic microcystins (MCs) produced by cyanobacteria are known to accumulate in gastropods following grazing of toxic cyanobacteria and/or absorption of MCs dissolved in water, with adverse effects on life history traits demonstrated in the laboratory. In the field, such effects may vary depending on species, according to their relative sensitivity and ecology. The aims of this study were to i) establish how various intensities of MC-producing cyanobacteria proliferations alter the structure of gastropod community and ii) compare MC tissue concentration in gastropods in the field with those obtained in our previous laboratory experiments on the prosobranch Potamopyrgus antipodarum and the pulmonate Lymnaea stagnalis. We explored these questions through a one-year field study at three stations at Grand-Lieu Lake (France) affected by different intensities of cyanobacteria proliferations. A survey of the community structure and MC content of both cyanobacteria and gastropods was associated with a caging experiment involving P. antipodarum and L. stagnalis. In total, 2592 gastropods belonging to 7 prosobranch and 16 pulmonate species were collected. However, distribution among the stations was unequal with 62% vs 2% of gastropods sampled respectively at the stations with the lowest vs highest concentrations of MC. Irrespective of the station, pulmonates were always more diverse, more abundant and occurred at higher frequencies than prosobranchs. Only the pulmonate Physa acuta occurred at all stations, with abundance and MC tissue concentration (≤ 4.32 μg g DW -1 ) depending on the degrees of MC-producing cyanobacteria proliferations in the stations; therefore, P. acuta is proposed as a potential sentinel species. The caging experiment demonstrated a higher MC accumulation in L. stagnalis (≤ 0.36 μg g DW -1 for 71% of individuals) than in P. antipodarum (≤ 0.02 μg g DW -1 for 12%), corroborating previous laboratory observations. Results are discussed in

  2. Monitoring changes in the intracellular calcium concentration and synaptic efficacy in the mollusc Aplysia.

    Science.gov (United States)

    Ludwar, Bjoern Ch; Evans, Colin G; Cropper, Elizabeth C

    2012-07-15

    It has been suggested that changes in intracellular calcium mediate the induction of a number of important forms of synaptic plasticity (e.g., homosynaptic facilitation). These hypotheses can be tested by simultaneously monitoring changes in intracellular calcium and alterations in synaptic efficacy. We demonstrate how this can be accomplished by combining calcium imaging with intracellular recording techniques. Our experiments are conducted in a buccal ganglion of the mollusc Aplysia californica. This preparation has a number of experimentally advantageous features: Ganglia can be easily removed from Aplysia and experiments use adult neurons that make normal synaptic connections and have a normal ion channel distribution. Due to the low metabolic rate of the animal and the relatively low temperatures (14-16 °C) that are natural for Aplysia, preparations are stable for long periods of time. To detect changes in intracellular free calcium we will use the cell impermeant version of Calcium Orange which is easily 'loaded' into a neuron via iontophoresis. When this long wavelength fluorescent dye binds to calcium, fluorescence intensity increases. Calcium Orange has fast kinetic properties and, unlike ratiometric dyes (e.g., Fura 2), requires no filter wheel for imaging. It is fairly photo stable and less phototoxic than other dyes (e.g., fluo-3). Like all non-ratiometric dyes, Calcium Orange indicates relative changes in calcium concentration. But, because it is not possible to account for changes in dye concentration due to loading and diffusion, it can not be calibrated to provide absolute calcium concentrations. An upright, fixed stage, compound microscope was used to image neurons with a CCD camera capable of recording around 30 frames per second. In Aplysia this temporal resolution is more than adequate to detect even a single spike induced alteration in the intracellular calcium concentration. Sharp electrodes are simultaneously used to induce and record

  3. Choose Your Weaponry: Selective Storage of a Single Toxic Compound, Latrunculin A, by Closely Related Nudibranch Molluscs.

    Directory of Open Access Journals (Sweden)

    Karen L Cheney

    Full Text Available Natural products play an invaluable role as a starting point in the drug discovery process, and plants and animals use many interesting biologically active natural products as a chemical defense mechanism against predators. Among marine organisms, many nudibranch gastropods are known to derive defensive metabolites from the sponges they eat. Here we investigated the putative sequestration of the toxic compound latrunculin A--a 16-membered macrolide that prevents actin polymerization within cellular processes--which has been identified from sponge sources, by five closely related nudibranch molluscs of the genus Chromodoris. Only latrunculin A was present in the rim of the mantle of these species, where storage reservoirs containing secondary metabolites are located, whilst a variety of secondary metabolites were found in their viscera. The species studied thus selectively accumulate latrunculin A in the part of the mantle that is more exposed to potential predators. This study also demonstrates that latrunculin-containing sponges are not their sole food source. Latrunculin A was found to be several times more potent than other compounds present in these species of nudibranchs when tested by in vitro and in vivo toxicity assays. Anti-feedant assays also indicated that latrunculin A was unpalatable to rock pool shrimps, in a dose-dependent manner. These findings led us to propose that this group of nudibranchs has evolved means both to protect themselves from the toxicity of latrunculin A, and to accumulate this compound in the mantle rim for defensive purposes. The precise mechanism by which the nudibranchs sequester such a potent compound from sponges without disrupting their own key physiological processes is unclear, but this work paves the way for future studies in this direction. Finally, the possible occurrence of both visual and chemosensory Müllerian mimicry in the studied species is discussed.

  4. Effects of bioturbation on the fate of oil in coastal sandy sediments - An em>in situem> experiment

    DEFF Research Database (Denmark)

    Timmermann, Karen; Banta, Gary T.; Klinge, Lars

    2011-01-01

    Effects of bioturbation by the common lugworm Arenicola marina on the fate of oil hydrocarbons (alkanes and PAHs) were studied in situ during a simulated oil spill in a shallow coastal area of Roskilde fjord, Denmark. The fate of selected oil compounds was monitored during 120 d using GC–MS and b......) mainly was affected by removal processes induced by wave actions and other bioturbating infauna such as Nereis diversicolor, Corophium volutator and Hydrobia spp. present in the experimental plots....

  5. COMPARATIVE SPERM ULTRASTRUCTURE OF BAIKALIAN ENDEMIC PROSOBRANCH GASTROPODS.

    Science.gov (United States)

    Ropstorf, PETER; Healy, JOHN M.; Riedel, FRANK; Sitnikova, TATIANA Y.

    2002-05-01

    Mature euspermatozoan ultrastructure is described for seven species of the rissooidean family Baicaliidae (endemic to Lake Baikal, Russia)-Liobaicalia stiedae, Teratobaikalia ciliata, T. macrostoma, Baicalia carinata, Pseudobaikalia pulla, Maackia bythiniopsis, M. variesculpta, and M. herderiana. For comparison with these species and previously investigated Rissooidea, two species of the Lake Baikal endemic genus Benedictia (B. cf. fragilis and B. baicalensis; Hydrobiidae: Benedictiinae of some authors, Benedictiidae of other authors) in addition to Lithoglyphus naticoides (Hydrobiidae: Lithoglyphinae) and Bythinella austriaca (Hydrobiidae: Bythinellinae) were also investigated. Paraspermatozoa were not observed in any of the species examined, supporting the view that these cells are probably absent in the Rissooidea. In general, the euspermatozoa of all species examined resemble those of many other caenogastropods (basally invaginated acrosomal vesicle, mid-piece with 7-13 helical mitochondria, an annulus, glycogen piece with nine peri-axonemal tracts of granules). However, the presence of a completely flattened acrosomal vesicle and a specialized peri-axonemal membranous sheath (a scroll-like arrangement of 4-6 double membranes) at the termination of the mid-piece, clearly indicates a close relationship between the Baicaliidae and other rissooidean families possessing these features (Bithyniidae, Hydrobiidae, Pyrgulidae, and Stenothyridae). Euspermatozoa of Benedictia, Lithoglyphus, Bythinella, and Pyrgula all have a solid nucleus, which exhibits a short, posterior invagination (housing the centriolar complex and proximal portion of the axoneme). Among the Rissooidea, this form of nucleus is known to occur in the Bithyniidae, Hydrobiidae, Truncatellidae, Pyrgulidae, Iravadiidae, Pomatiopsidae, and Stenothyridae. In contrast, the euspermatozoa of the Baicaliidae all have a long, tubular nucleus, housing not only the centriolar derivative, but also a substantial portion of the axoneme. Among the Rissooidea, a tubular nuclear morphology has previously been seen in the Rissoidae, which could support the view, based on anatomical grounds, that the Baicaliidae may have arisen from a different ancestral source than the Hydrobiidae. However, the two styles of nuclear morphology (short, solid versus long, tubular) occur widely within the Caenogastropoda, and sometimes both within a single family, thereby reducing the phylogenetic importance of nuclear differences within the Rissooidea. More significantly, the occurrence of the highly unusual membranous sheath within the mid-piece region in the Baicaliidae appears to tie this family firmly to the Bithyniidae + Hydrobiidae + Stenothyridae + Pyrgulidae assemblage. Eusperm features of Benedictia spp. strongly resemble those of hydrobiids and bithyniids, and neither support recognition of a distinct family Benedictiidae (at best this is a subfamily of Hydrobiidae) nor any close connection with the hydrobiid subfamily Lithoglyphinae.

  6. Gametogenic activity in three internally fertilized prosobranchs from ...

    African Journals Online (AJOL)

    1987-07-09

    Jul 9, 1987 ... Africa, with notes on the egg capsules of Burnupena Jagenaria .... Ovarian development, however, appeared to ... PholOmicrographs of hislOlogical sections showing four reproductive phases in female Burnupena lagenaria.

  7. Decadal climate variation recorded in modern global carbonate archives (brachiopods, molluscs)

    Science.gov (United States)

    Romanin, Marco; Zaki, Amir H.; Davis, Alyssa; Shaver, Kristen; Wang, Lisha; Aleksandra Bitner, Maria; Capraro, Luca; Preto, Nereo; Brand, Uwe

    2017-04-01

    The progress of the Earth's warming trend has rapidly accelerated in the last few decades due to the increase in emission of anthropogenic greenhouse gases. The exchange of heat between the atmosphere and seawater has consequently elevated the rate of temperature buildup in the low and high latitude ocean. Records of the variation in seawater temperature in response to local and global changes in climate are preserved within the carbonate structures of marine biogenic archives. Investigating the isotopic composition of the archives' growth increments documents the magnitude of sea surface temperature (SST) change. A long-term (1956-2012) record of temperature change in sub-tropical seawater was acquired from the giant clam Tridacna maxima collected from the Red Sea in conjunction with published results of the oyster Hyotissa hyotis (Titschack et al., 2010). Variation in polar-subpolar SST was obtained from the brachiopod Magellania venosa recovered from the coastal area of southern Chile, and from the proxy record of Hemithiris psittacea of Hudson Bay (Brand et al., 2014). The former reveals a long-term (1961-2012) time-series of Antarctic-induced oceanographic change in the southern hemisphere, while the latter represents a trend of Hudson Bay seawater SST in the northern hemisphere. Evaluation of the isotopic compositions confirms the equilibrium incorporation of oxygen isotopes with respect to ambient seawater in brachiopods and some bivalves. A general trend of decreasing δ18O values in the Red Sea molluscs is observed, indicating an increase in tropical seawater temperature of about 0.79°C since 1988. The δ18O values of the polar-subpolar brachiopods display similar depletion slopes but of larger magnitudes than that of the Red Sea archives. This signifies a rise in seawater temperature of about 1.47°C in Hudson Bay since 1991, and about 2.08°C in southern Chile since 1988. The 2013 IPCC report suggests an increase in SST of +0.094°C per decade (average

  8. A high molecular weight proteoglycan is differentially expressed during development of the mollusc Concholepas concholepas (Mollusca; Gastropoda; Muricidae).

    Science.gov (United States)

    Brandan, E; González, M; Inestrosa, N C; Tremblay, C; Urrea, R

    1992-12-15

    Incorporation of radioactive sulfate to hatched veliger larvae of the gastropod muricid Concholepas concholepas indicated that over 87% of the sulfated macromolecules were found in the detergent insoluble fraction, rich in extracellular matrix (ECM) components. The sulfated material was solubilized with guanidine salt followed by urea dialysis and fractionated by DEAE-Sephacel chromatography. Three sulfated compounds eluting at 0.7, 1.1, and 3.0 M NaCl, called peaks I, II, and III, respectively, were obtained. The sulfated compound present in peak I was degraded by pronase or sodium alkaline treatment to a small sulfated resistant material, suggesting the presence of a proteoglycan (PG). Filtration analysis on Sephacryl S-500 and SDS-PAGE of the intact PG indicates that it has a high molecular weight (360,000 to over 1 x 10(6)). Monoclonal antibodies (mAb) against this PG were produced. The specificity of one mAb, the 6H2, was demonstrated by size chromatography and ELISA analysis. The epitope recognized by this mAb seems to be present in the core protein of the PG. Both the extent of sulfation and the presence of different sulfated species of PGs were evaluated during the development of this mollusc. A twelvefold increase in the incorporation of sulfate to PGs per milligram of protein was found in veliger larvae compared to blastula-glastula stages. This change correlated well with the differential expression of the sulfated PG present in peak I. Biochemical and immunological analysis indicate that high levels of this PG are found in veliger and trocophore larvae in comparison with blastula-gastrula and early juveniles.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Reproductive impacts of tributyltin (TBT) and triphenyltin (TPT) in the hermaphroditic freshwater gastropod Lymnaea stagnalis

    OpenAIRE

    Giusti, Arnaud; Barsi, Alpar; Dugue, Mael; Collinet, Marc; Thome, Jean-Pierre; Joaquim-Justo, Celia; Roig, Benoit; Lagadic, Laurent; Ducrot, Virginie

    2013-01-01

    Tributyltin (TBT) and triphenyltin (TPT) are emblematic endocrine disruptors, which have been mostly studied in gonochoric prosobranchs. Although both compounds can simultaneously occur in the environment, they have mainly been tested separately for their effects on snail reproduction. Because large discrepancies in experimental conditions occurred in these tests, the present study aimed at comparing the relative toxicity of TBT and TPT under similar laboratory conditions in the 0–600 ng Sn/L...

  10. Modulation of pumping rate by two species of marine bivalve molluscs in response to neurotransmitters: Comparison of in vitro and in vivo results.

    Science.gov (United States)

    Frank, Dana M; Deaton, Lewis; Shumway, Sandra E; Holohan, Bridget A; Ward, J Evan

    2015-07-01

    Most studies regarding the neuroanatomy and neurophysiology of molluscan ctenidia have focused on isolated ctenidial tissue preparations. This study investigated how bivalve molluscs modulate their feeding rates by examining the effects of a variety of neurotransmitters, including serotonin, dopamine, and the dopamine agonist apomorphine on both isolated ctenidial tissue and in intact members of two commercially important bivalve species: the blue mussel, Mytilus edulis; and the bay scallop Argopecten irradians. In particular, we examined the effect of changes in: 1) beat of the lateral cilia (in vitro), 2) distance between ctenidial filaments and/or plicae (in vivo), and 3) diameter of the siphonal openings (in vivo) on alteration of bulk water flow through the mantle cavity. Important differences were found between isolated tissue and whole animals, and between species. Drugs that stimulated ciliary beat in vitro did not increase water processing rate in vivo. None of the treatments increased water flow through the mantle cavity of intact animals. Results suggest that A. irradians was primarily modulating lateral ciliary activity, while M. edulis appeared to have a number of ways to control water processing activity, signifying that the two species may have different compensatory and regulatory mechanisms controlling feeding activity. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Comparison of gastropod mollusc (Apogastropoda: Hydrobiidae habitats in two crater lakes in Nicaragua

    Directory of Open Access Journals (Sweden)

    Jeffrey K McCrary

    2008-03-01

    Full Text Available The aquatic gastropod mollusc, Pyrgophorus coronatus, may perform an important role in the transmission of an emergent ocular pathology among fishes in Lake Apoyo, Nicaragua. This disease emerged after an introduction of tilapia (Oreochromis niloticus and the subsequent loss of Chara sp. beds in the lake. We compared the mollusc population densities in three habitats (sandy/muddy substrates, rocks, and Chara vegetation at varying depths (1.5, 10, 20, and 30 m in two volcanic crater lakes in Nicaragua: Lake Apoyo and Lake Xiloa, where lower numbers of affected fishes were found and tilapia has not been introduced. Duplicate samples at 1.5 m depth were taken in each habitat monthly for a year, and triplicate samples for bathymetric analysis of snail populations were performed during August, 2005. Samples of fixed surface area were filtered in a 0.4 cm size screen and live snails were counted from each sample. The preferred snail habitat in both lakes, Chara beds, was vastly reduced in Lake Apoyo via consumption by introduced Nile tilapia (Oreochromis niloticus. Structureless sandy substrates (mean ± standard error 3.1±1.3 ind/m² had lower population densities than other habitats in Lake Xiloá (rocks 590.9±185.3 ind/m²; vegetation 3 686.5±698.2 ind/m2; ANOVA I, pEl gasterópodo acuático, Pyrgophorus coronatus, podría jugar un papel importante en la transmisión de una patología ocular emergente entre los peces de la laguna de Apoyo, Nicaragua. Esta enfermedad surgió después de una introducción de tilapia (Oreochromis niloticus y la subsecuente pérdida de lechos de Chara sp. en la laguna. Comparamos las densidades poblacionales del caracol en tres hábitats (substratos arenosos/lodosos, rocas y vegetación de Chara en dos lagunas cratéricas volcánicas en Nicaragua: La laguna de Apoyo y la laguna de Xiloá, donde no se encuentraron grandes cantidades de peces afectados y donde no se han introducido tilapias. Mensualmente, por un a

  12. Recommended reporting standards for test accuracy studies of infectious diseases of finfish, amphibians, molluscs and crustaceans: the STRADAS-aquatic checklist

    Science.gov (United States)

    Gardner, Ian A; Whittington, Richard J; Caraguel, Charles G B; Hick, Paul; Moody, Nicholas J G; Corbeil, Serge; Garver, Kyle A.; Warg, Janet V.; Arzul, Isabelle; Purcell, Maureen; St. J. Crane, Mark; Waltzek, Thomas B.; Olesen, Niels J; Lagno, Alicia Gallardo

    2016-01-01

    Complete and transparent reporting of key elements of diagnostic accuracy studies for infectious diseases in cultured and wild aquatic animals benefits end-users of these tests, enabling the rational design of surveillance programs, the assessment of test results from clinical cases and comparisons of diagnostic test performance. Based on deficiencies in the Standards for Reporting of Diagnostic Accuracy (STARD) guidelines identified in a prior finfish study (Gardner et al. 2014), we adapted the Standards for Reporting of Animal Diagnostic Accuracy Studies—paratuberculosis (STRADAS-paraTB) checklist of 25 reporting items to increase their relevance to finfish, amphibians, molluscs, and crustaceans and provided examples and explanations for each item. The checklist, known as STRADAS-aquatic, was developed and refined by an expert group of 14 transdisciplinary scientists with experience in test evaluation studies using field and experimental samples, in operation of reference laboratories for aquatic animal pathogens, and in development of international aquatic animal health policy. The main changes to the STRADAS-paraTB checklist were to nomenclature related to the species, the addition of guidelines for experimental challenge studies, and the designation of some items as relevant only to experimental studies and ante-mortem tests. We believe that adoption of these guidelines will improve reporting of primary studies of test accuracy for aquatic animal diseases and facilitate assessment of their fitness-for-purpose. Given the importance of diagnostic tests to underpin the Sanitary and Phytosanitary agreement of the World Trade Organization, the principles outlined in this paper should be applied to other World Organisation for Animal Health (OIE)-relevant species.

  13. Příspěvek k poznání vodních měkkýšů severní části CHKO Orlické hory

    Directory of Open Access Journals (Sweden)

    Luboš Beran

    2009-03-01

    Full Text Available This paper brings a review of a malacological survey of the northern part of the Orlické Hory Protected Landscape Area, situated in northwestern part of Bohemia (Czech Republic near boundary between the Czech Republic and Poland. Altogether, only 12 common species of aquatic molluscs (8 gastropods, 4 bivalves were found. Galba truncatula, Radix peregra, Ancylus fluviatilis, Pisidium personatum, and P. casertanum belong to the most frequent molluscs found during this research. Occurrence of vulnerable or endangered molluscs as well as non-native molluscs was not documented in this area.

  14. Proterometra epholkos sp. n. (Digenea: Azygiidae) from Terrapin Creek, Alabama, USA: molecular characterization of life cycle, redescription of Proterometra albacauda, and updated lists of host and geographic locality records for Proterometra spp. in North America.

    Science.gov (United States)

    Womble, Matthew R; Orélis-Ribeiro, Raphael; Bullard, Stephen A

    2015-02-01

    Proterometra epholkos sp. n. asexually reproduces in the stream dwelling prosobranch, Elimia cf. modesta (Cerithioidea: Pleuroceridae) and infects the buccal cavity epithelium of spotted bass, Micropterus punctulatus (Perciformes: Centrarchidae) in the Coosa River (Terrapin Creek; N33°51'36.56″, W85°31'28.15″; Cleburne County, Alabama, USA). We characterize cercariae and adults of the new species using morphology and molecular sequence data and redescribe its morphologically similar congener Proterometra albacauda based on the holotype and paratype (USNPC Nos. 61229-30). The new species can be distinguished most easily from P. albacauda by the combination of having cercariae with long mamillae (>100μm) that encircle the tail stem anteriorly, that are restricted to 1 lateral column per body margin at midbody, and that are absent from the medial surface of the tail stem as well as by having adults with a partly extracecal uterus, a transverse metraterm occupying the space between the oral sucker and prostatic sac, and a vitellarium that is longer than the ceca and extends anteriad to the level of or beyond the posterior margin of the oral sucker. Sequence data from the ribosomal internal transcribed spacer 2 (ITS2; 251bp) did not reject the notion that the cercariae and adults we collected simultaneously from those infected, sympatric, individual snails and fish in Terrapin Creek were conspecific. Also provided herein for species of Proterometra are (i) taxonomic keys for cercariae and adults based on morphological and behavioral characteristics sourced from the published literature, (ii) updated lists of host records (prosobranchs and fishes) and geographic locality records for Proterometra spp., and (iii) synopses and assessments of the morphological features previously used to differentiate them. Proterometra macrostoma (type species), Proterometra melanophora, and Proterometra hodgesiana are species inquirendae; requiring new collections from type

  15. Biomonitoring of Heavy metals using the bivalve molluscs in sunderban mangrove wetland, Northeast Coast of Bay of bengal (india): possible risks to Human health

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, Henrique; Cardoso, Ines [Departamento de Biologia Animal/Instituto de Oceanografia, Campo Grande, Lisboa (Portugal); Chatterjee, Mousumi; Kumar Bhattacharya, Asok; Aftab Alam, Mohammad [Department of Marine Science, University of Calcutta, Calcutta (India); Kanta Satpathy, Kamala [Indira Gandhi Centre for Atomic Research, Environmental and Industrial Safety Section, Safety Group, Kalpakkam, Tamil Nadu (India); Kumar Sarkar, Santosh

    2008-02-15

    The suitability of using four bivalve molluscs (Sanguinolaria acuminata, Anadara granosa, Meretrix meretrix, and Pelecyora trigona) in biomonitoring of heavy metals (Cu, Pb, Cd, Zn, and Hg) collected from intertidal regions of the Sunderban mangrove wetland, northeastern part of the Bay of Bengal, were evaluated. Both speciesdependent variability and temporal variations were pronounced. A high degree of organ specificity was evident in the bivalves where gill and mantle exhibited higher metal accumulation due to ion exchange property of the mucous layer covering these organs while shells represent very poor accumulation. Elevated values of Zn and Cu reflect high potential for biomagnification through marine food chain. Metal concentrations in different body size groups of the bivalves do not follow uniform trend. Correlation coefficient between different metal couplings as tested statistically revealed significant coupling for Pb-Zn, Pb-Cu, Zn-Cu, and Hg-Cu. Concentrations of all the metals in specific organs (visceral mass, mantle and gill) of the bivalves exceeded the safe levels according to the international standards for metals compiled by Food and Agricultural Organization of the United Nations and would be of great risk for human consumption. It is concluded that the mussel and clam are suitable biomonitors to employ in programs designed to assess changes in metal pollution in the Sunderban mangrove wetland. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  16. The importance of pre-annealing treatment for ESR dating of mollusc shells: A key study for İsmil in Konya closed Basin/Turkey

    Science.gov (United States)

    Ekici, Gamze; Sayin, Ulku; Aydin, Hulya; Isik, Mesut; Kapan, Sevinc; Demir, Ahmet; Engin, Birol; Delikan, Arif; Orhan, Hukmu; Biyik, Recep; Ozmen, Ayhan

    2018-02-01

    In this study, Electron Spin Resonance (ESR) spectroscopy is used to determine the geological ages of fossil mollusc shells systematically collected from two different geological splitting at İsmil Location (37.72769° N, 33.17781° E) in eastern part of Konya. According to the assessment of obtained ESR ages, the importance of pre-annealing treatment emphasize in the case of g=2.0007 dating signal is overlapped with the other signals arisen from short lived radicals that cause the wrong age calculation. To overcome this problem, the samples are pre-annealed at 180°C for 16 minutes and, in this case ESR ages are re-calculated for g=1.9973 dating signal. Dose response curves are obtained using 1.9973 signals after pre-annealing treatments for each samples. ESR ages of samples are obtained in the range of 138 ± 38 ka and 132 ± 30 ka (Upper Pleistocene) according to the Early Uranium Uptake model and the results are in good agreement with the estimated ages from stratigraphic and paleontological correlation by geologists. Thus, it is suggested that especially in the case of 2.0007 dating signal cannot been used due to superimposition case, the signal with 1.9973 g value can be used for dating after pre-annealing treatment. The results reports the first ESR ages on shells collected from İsmil Location and highlight the importance of pre-annealing treatment. This study is supported by TUBITAK 114Y237 research project.

  17. Genotoxic, cytotoxic, developmental and survival effects of tritiated water in the early life stages of the marine mollusc, Mytilus edulis

    Energy Technology Data Exchange (ETDEWEB)

    Hagger, Josephine A. [School of Biological Sciences, University of Plymouth, Drake Circus, Devon, Plymouth PL4 8AA (United Kingdom); Atienzar, Franck A. [School of Biological Sciences, University of Plymouth, Drake Circus, Devon, Plymouth PL4 8AA (United Kingdom); Jha, Awadhesh N. [School of Biological Sciences, University of Plymouth, Drake Circus, Devon, Plymouth PL4 8AA (United Kingdom)]. E-mail: ajha@plymouth.ac.uk

    2005-09-10

    Using an integrated approach linking different levels of biological organisation, the genotoxic, cytotoxic, developmental and survival impact of tritiated water (HTO) were investigated in the embryo-larvae of marine mollusc Mytilus edulis. One-hour-old embryos were exposed to a range of concentrations (0.37-370 kBq ml{sup -1}) of HTO, which delivered a dose between 0.02 and 21.41 mGy over the exposure period for different end points. Detrimental effects, if any, were monitored at different levels of biological organisation (i.e. DNA, chromosomal, cellular and individual). Genotoxic effects were assessed using molecular and cytogenetic approaches which included analysis of random amplified polymorphic DNA (RAPD), induction of sister chromatid exchanges (SCEs) and chromosomal aberrations (Cabs). Cytotoxic effects were evaluated by determining the proliferative rate index (PRI) of the embryo-larval cells. Developmental and survival effects were also monitored every 24 h up to 72 h. Results in general indicated that HTO significantly increased cytogenetic damage, cytotoxicity, developmental abnormalities and mortality of the embryo-larvae as a function of concentration or radiation dose. The analysis of RAPD profiles also revealed qualitative effects in the HTO exposed population compared to controls. However, while the embryo-larvae showed dose or concentration dependent effects for mortality, developmental abnormalities and induction of SCEs, the dose-dependent effects were not apparent for Cabs and PRI at higher doses. The study contributes to our limited understanding of the impact of environmentally relevant radionuclides on non-human biota and emphasises the need for further investigations to elucidate potentially long term damage induced by persistent, low levels of other radionuclides on commercially and ecologically important species, in order to protect human and ecosystem health.

  18. Reproductive impacts of tributyltin (TBT) and triphenyltin (TPT) in the hermaphroditic freshwater gastropod Lymnaea stagnalis.

    Science.gov (United States)

    Giusti, Arnaud; Barsi, Alpar; Dugué, Maël; Collinet, Marc; Thomé, Jean-Pierre; Joaquim-Justo, Célia; Roig, Benoit; Lagadic, Laurent; Ducrot, Virginie

    2013-07-01

    Tributyltin (TBT) and triphenyltin (TPT) are emblematic endocrine disruptors, which have been mostly studied in gonochoric prosobranchs. Although both compounds can simultaneously occur in the environment, they have mainly been tested separately for their effects on snail reproduction. Because large discrepancies in experimental conditions occurred in these tests, the present study aimed to compare the relative toxicity of TBT and TPT under similar laboratory conditions in the range of 0 ng Sn/L to 600 ng Sn/L. Tests were performed on the simultaneous hermaphrodite Lymnaea stagnalis, a freshwater snail in which effects of TPT were unknown. Survival, shell length, and reproduction were monitored in a 21-d semistatic test. Frequency of abnormal eggs was assessed as an additional endpoint. Triphenyltin hampered survival while TBT did not. Major effects on shell solidity and reproduction were observed for both compounds, reproductive outputs being more severely hampered by TBT than by TPT. Considering the frequency of abnormal eggs allowed increasing test sensitivity, because snail responses to TBT could be detected at concentrations as low as 19 ng Sn/L. However, the putative mode of action of the 2 compounds could not be deduced from the structure of the molecules or from the response of apical endpoints. Sensitivity of L. stagnalis to TBT and TPT was compared with the sensitivity of prosobranch mollusks with different habitats and different reproductive strategies. Copyright © 2013 SETAC.

  19. Sediment core fossils in ancient Lake Ohrid: testing for faunal change since the Last Interglacial

    Directory of Open Access Journals (Sweden)

    C. Albrecht

    2010-11-01

    Full Text Available Ancient Lake Ohrid is probably of early Pleistocene or Pliocene origin and amongst the few lakes in the world harbouring an outstanding degree of endemic biodiversity. Although there is a long history of evolutionary research in Lake Ohrid, particularly on molluscs, a mollusc fossil record has been missing up to date. For the first time, gastropod and bivalve fossils are reported from the basal, calcareous part of a 2.6 m long sediment succession (core Co1200 from the north-eastern part of Lake Ohrid. Electron spin resonance (ESR dating of mollusc shells from the same stratigraphic level yielded an age of 130 ± 28 ka. Lithofacies III sediments, i.e. a stratigraphic subdivision comprising the basal succession of core Co1200 between 181.5–263 cm, appeared solid, greyish-white, and consisted almost entirely of silt-sized endogenic calcite (CaCO3>70% and intact and broken mollusc shells. Here we compare the faunal composition of the thanatocoenosis with recent mollusc associations in Lake Ohrid. A total of 13 mollusc species (9 gastropod and 4 bivalve species could be identified within Lithofacies III sediments. The value of sediment core fossils for reconstructing palaeoenvironmental settings was evaluated and the agreement between sediment and palaeontological proxies was tested.

    The study also aims at investigating major faunal changes since the Last Interglacial and searching for signs of extinction events.

    The combined findings of the ecological study and the sediment characteristics suggest deposition in a shallow water environment during the Last Interglacial. The fossil fauna exclusively included species also found in the present fauna, i.e. no extinction events are evident for this site since the Last Interglacial. The thanatocoenosis showed the highest similarity with recent Intermediate Layer (5–25 m water depth mollusc assemblages. The demonstrated existence of a mollusc fossil record in Lake Ohrid

  20. Catalogue systématique des mollusques (gastropodes prosobranches et polyplacophores)

    NARCIS (Netherlands)

    Horst, R.; Schepman, M.M.

    1908-01-01

    La collection conchyliologique du Musée d’Histoire Naturelle des Pays-Bas est d’origine très hétérogène. Au premier lieu elle dérive du Cabinet de Zoologie, d’Anatomie Comparée et de Minéralogie de l’Université de Leide, qui surtout sous la direction du professeur Brugmans (1786—1819) s’était

  1. Příspěvek k poznání vodních měkkýšů evropsky významné lokality Bystřice se zaměřením na populaci velevruba tupého (Unio crassus A contribution to the knowledge of aquatic molluscs of the Bystřice SCI focused on the population of Unio crassus

    Directory of Open Access Journals (Sweden)

    Luboš Beran

    2011-03-01

    Full Text Available This paper brings results of a malacological survey of the Bystřice River on the territory of the Site of Community Importance (SCI Bystřice (Eastern Bohemia, Czech Republic. The research was focused on the population of endangered bivalve Unio crassus which is the main object of conservation of this SCI. Twenty one species of aquatic molluscs (11 gastropods, 10 bivalves were found in 2010. Most of the molluscs belong to common and widespread species. Altogether 26 species have been found during research in the Bystřice River since 2000. Expansion of non-native species Potamopyrgus antipodarum and Physella acuta is the most visible change in comparison with the previous research. The research in 2010 confirmed existence of the occurrence of Unio crassus all over the SCI and also upstream of this site. The population density documented in 2010 was higher than that found during the previous research. In the upper part of the SCI, the density of U. crassus population was at least 1 ind./1 m of the river stream while in the lower part it did not exceed 1 ind. per 10 m of the river. The reason was the canalisation of the river and the absence of suitable sediments. The occurrence of the bivalve was not recorded downstream of the SCI.

  2. Cytogenetic and morphophysiological differences in snail Lymnaea stagnalis (Gastropoda, Pulmonata) from reservoirs of the Chernobyl NPP resettling zone

    International Nuclear Information System (INIS)

    Koneva, A.Yu.; Afonin, V.Yu.; Dramashka, S.Ya.; Golubew, A.P.

    2006-01-01

    A cytogenetic analysis of the molluscs obtained from animals of two populations of the Chernobyl NPP zone was carried out. Preservation of the raised number of cells with micronuclei in hemolymph of the molluscs obtained from animals lived under conditions with the highest level of radiation contamination was noted. Interpopulational distinctions in a number of biological parameters were revealed. Away of fertilization which is used for animal production under laboratory conditions affects sensitivity of molluscs to additional acute irradiation was established. (authors)

  3. Marine Science

    African Journals Online (AJOL)

    importance of intertidal molluscs, Kaullysing et al. document the density and diversity of the benthic molluscs ... Natural hormonal compounds or artificial chemicals. Abstract ... lagoon area when compared with that in the reef and beach areas.

  4. Feeding behaviour and food selection in the horseshoe crab, Tachypleus gigas (Muller)

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A; Mishra, J.K.; Parulekar, A

    The Indian horseshoe crab, Tachypleus gigas, is a benthic feeder which subsists mainly on molluscs, decayed organic matter and polychaetes, in order of prevalence. A strong and positive preference was recorded for molluscs over other food organisms...

  5. ESR analyses for herbivore teeth and molluscs from Kharga, Dakhleh, and Bir Tarfawi Oases: Constraining water availability and hominin paleolithic activity in the Western Desert, Egypt

    Science.gov (United States)

    Blackwell, B. A. B.; Skinner, A. R.; Smith, J. R.; Hill, C. L.; Churcher, C. S.; Kieniewicz, J. M.; Adelsberger, K. A.; Blickstein, J. I. B.; Florentin, J. A.; Deely, A. E.; Spillar, K. V.

    2017-12-01

    Today, Bir Tarfawi, Kharga and Dakhleh Oases all sit in Egypt's hyperarid Western Desert. A dearth of naturally occurring surface water coupled with ≤ 0.1 mm/y of precipitation, and evaporation rates > 2 m/y make Bir Tarfawi uninhabitable today, while Dakhleh and Kharga depend on borehole water to support human inhabitation. Yet in scattered locations dotting the Quaternary surfaces and deposits near each oasis, Paleolithic artefacts, fossil ungulate teeth, and snails record times when surface water did exist in wetlands, small ponds, and even large lakes. At Bir Tarfawi in Marine Isotope Stages (MIS) 5, 7, and 13, wetlands or small lakes supported freshwater snails, large herbivores, and hominins. Dakhleh Oasis hosted a large lake in MIS 6 that provided a deep reliable water supply for many millennia subsequently. ESR dates on fossils and tufa dates show thriving lacustrine and terrestrial ecosystems at Dakhleh during MIS 5, 7, 9, 11, and 17, and in shorter episodes in MIS 1, 2, 3, 6, and 12. At Kharga Oasis, springs discharged along the Libyan Escarpment edge, but the water was ponded in small basins dammed within tufa deposits. These dated deposits and fossils attest that water existed there in MIS 2-11, and one spot dating to ∼ 2.3 Ma. This proxy evidence suggest that, thanks to higher rainfall and/or groundwater tables, sufficient water persisted for much of the Pleistocene, supporting food resources, like large herbivores and molluscs, to thrive and enabling hominin habitation. and activity in the Western Desert.

  6. Step process for selecting and testing surrogates and indicators of afrotemperate forest invertebrate diversity.

    Directory of Open Access Journals (Sweden)

    Charmaine Uys

    Full Text Available BACKGROUND: The diversity and complexity of invertebrate communities usually result in their exclusion from conservation activities. Here we provide a step process for assessing predominantly ground-dwelling Afrotemperate forest invertebrates' (earthworms, centipedes, millipedes, ants, molluscs potential as surrogates for conservation and indicators for monitoring. We also evaluated sampling methods (soil and litter samples, pitfall traps, active searching quadrats and tree beating and temporal (seasonal effects. METHODOLOGY/PRINCIPAL FINDINGS: Lack of congruence of species richness across taxa indicated poor surrogacy potential for any of the focus taxa. Based on abundance and richness, seasonal stability, and ease of sampling, molluscs were the most appropriate taxon for use in monitoring of disturbance impacts. Mollusc richness was highest in March (Antipodal late summer wet season. The most effective and efficient methods were active searching quadrats and searching litter samples. We tested the effectiveness of molluscs as indicators for monitoring by contrasting species richness and community structure in burned relative to unburned forests. Both species richness and community structure changed significantly with burning. Some mollusc species (e.g. Macroptychia africana showed marked negative responses to burning, and these species have potential for use as indicators. CONCLUSIONS/SIGNIFICANCE: Despite habitat type (i.e., Afrotemperate forest being constant, species richness and community structure varied across forest patches. Therefore, in conservation planning, setting targets for coarse filter features (e.g., habitat type requires fine filter features (e.g., localities for individual species. This is especially true for limited mobility taxa such as those studied here. Molluscs have high potential for indicators for monitoring, and this requires broader study.

  7. THE STATUS OF MOLLUSK DIVERSITY AND PHYSICAL SETTING OF THE MANGROVE ZONES IN CATANDUANES ISLAND, LUZON, PHILIPPINES

    Directory of Open Access Journals (Sweden)

    JIMMY T. MASAGCA

    2010-09-01

    Full Text Available The status of mollusk diversity and physical setting of mangrove areas in Catanduanes island, Luzon (Philippines are described. A total of 57 species of mollusks, consisting of 27 gastropods and 30 bivalves were recorded in the island. Registering higher values of species diversity indices (Margalef and species richness (Menhinick are the prosobranch, Terebralia sulcata; corbiculid bivalve, Geloina coaxans; potamidiids, Cerithidea cingulata and Cerithidea rhizophorarum; and two other species of the genus Littorina (Littorinopsis. Using the physiographic model, majority of the mangrove areas under study follow the composite river and wave-dominated setting with some few areas having the wave-dominated, tide-dominated allochthonous setting.

  8. Mesure de l'uranium dans un ensemble d'échantillons de formations ...

    African Journals Online (AJOL)

    The analyses were carried out on some of natural deposits samples such as the corals, the fossil shells molluscs, the phosphates, the travertines, the lichens and of the impure carbonate deposits. Measurements were realized by spectrometry alpha for fossil shell molluscs, corals, travertines and impure carbonates, ...

  9. Effects of 4-n-nonylphenol on the Prosobranch Snail Marisa cornuarietis

    OpenAIRE

    Dahl, Mads-Peter Jakob; Mariager, Nadja M; Hansen, Sandra F

    2005-01-01

    The awareness of endocrine disrupting chemicals (EDC’s) has increased throughout the last decade due to great amounts released into the environment by the industry. In this study we have investigated the effect of the abundant EDC, 4-n-nonylphenol, on the gastropod Marisa cornuarietis, as very little attention has been dedicated to the invertebrates responses to EDC’s. M. cornuarietis was exposed to a nominal concentration of 4-n-NP of 100µg/L for a period of 34 days. The experiment was perfo...

  10. Culinary ecology

    International Nuclear Information System (INIS)

    Koshkin, A.

    1996-01-01

    Effect of petroleum, petroleum products, heavy metals and other pollutants on sea organisms and on molluscs in particular is considered. It is shown that molluscs represent the original biological indicators of seawater pollution by petroleum products: the character of pollutions can be determined according to their behaviour, state and number

  11. On the role of water and forage in penetration of some radionuclides into the Limnaea organism

    International Nuclear Information System (INIS)

    Marchyulenene, D.P.; Polikarpov, G.G.; AN Ukrainskoj SSR, Sevastopol. Inst. Biologii Yuzhnykh Morej)

    1976-01-01

    The objective of this work was to study under laboratory conditions the significance of elodea (Elodea canadensis Rich.) and aqueous medium in accumulation of strontium-90, cesium-137, cerium-144 and ruthenium-106 by limnetic gastropods (Limnaea Stagnalis L.). The study revealed that only 2 and 5% of strontium-90 and cerium-144 respectively were accumulated in molluscs shell from radioactive food, and 4 and 26% - in the body. The authors believed that higher accumulation levels of cerium-144 and ruthenium-106 in mollusca body when the molluscs are fed with radioactive elodea were caused by high accumulation coefficients (AC) of radionuclides in food, i.e. elodea, and their accumulation in the gastrointestinal tracts of molluscs. To appreciates the significance of elodea and water as sources of radionuclide accumulation by mollusca, strontium-90 and cerium-144 AC in molluscs were estimated in relation to water and elodea. The results obtained indicated that AC of these radionuclides in mollusca was much lower in relation to food than to water

  12. Caribbean Land Molluscs: Vertiginidae

    NARCIS (Netherlands)

    Haas, Fritz

    1960-01-01

    The area dealt with in this publication requires definition. In order to avoid misunderstanding, its individual components are listed as follows (see Table 1): Bahamas — Bimini’s, Cat Key, New Providence Lesser Antilles, with the following groups: Virgin Islands — St. Thomas, St. John, St. Croix

  13. Antimicrobial peptides in marine invertebrate health and disease

    OpenAIRE

    Destoumieux-Garzón, Delphine; Rosa, Rafael Diego; Schmitt, Paulina; Barreto, Cairé; Vidal-Dupiol, Jeremie; Mitta, Guillaume; Gueguen, Yannick; Bachère, Evelyne

    2016-01-01

    Aquaculture contributes more than one-third of the animal protein from marine sources worldwide. A significant proportion of aquaculture products are derived from marine protostomes that are commonly referred to as ‘marine invertebrates’. Among them, penaeid shrimp (Ecdysozosoa, Arthropoda) and bivalve molluscs (Lophotrochozoa, Mollusca) are economically important. Mass rearing of arthropods and molluscs causes problems with pathogens in aquatic ecosystems that are exploited by humans. Remark...

  14. No substantial changes in estrogen receptor and estrogen-related receptor orthologue gene transcription in Marisa cornuarietis exposed to estrogenic chemicals

    OpenAIRE

    Beresford, N; Granger, DW; Pounds, NA; Rand-Weaver, M; White, R; Jobling, S; Routledge, EJ

    2013-01-01

    This article is made available through the Brunel Open Access Publishing Fund. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-No Derivative Works License, which permits non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited. Estrogen receptor orthologues in molluscs may be targets for endocrine disruptors, although mechanistic evidence is lacking. Molluscs ...

  15. Analysis of the scallop microbiota by means of 16S rRNA gene pyrosequencing

    OpenAIRE

    Alex Mira; Jesus L Romalde

    2014-01-01

    Bivalve molluscs, due to its filter-feeding mechanism, have an abundant associated bacterial microbiota composed of a large number of species of different genera. The knowledge about the composition of the microbiota associated with bivalve molluscs is based, mostly, on techniques of cultivation of microorganisms, but also on DGGE methods. However, it is estimated that less than 1% of the bacteria are culturable with current methods, which lead to an underestimation of the microbial diversity...

  16. Can molluscan assemblages give insights into Holocene environmental changes other than sea level rise? A case study from a macrotidal bay (Marennes-Oleron, France)

    OpenAIRE

    Poirier, Clement; Sauriau, Pierre-guy; Chaumillon, Eric; Allard, Jonathan

    2009-01-01

    During the Late Holocene, the rate of sea level rise decreased and climate changes, hydrodynamic processes or anthropogenic impacts became predominant parameters governing the sedimentary infill of estuarine environments. The aim of this study is to describe the response of past benthic mollusc communities to these forcing factors. Mollusc skeletal remains were sampled from three 8000, 5500 and 2600 year-long sedimentary records in the Marennes-Oleron Bay (Atlantic Coast, France), where envir...

  17. An evaluation of intertidal feeding habitats from a shorebird perspective: Towards relevant comparisons between temperate and tropical mudflats

    Science.gov (United States)

    Piersma, Theunis; de Goeij, Petra; Tulp, Ingrid

    Macrozoobenthic communities of intertidal soft sediments are reviewed worldwide from the perspective of a mollusc-eating shorebird species. Based on 19 sites, total biomass figures varied between 5 and 80 g AFDM per m 2 (average 24 g AFDM per m 2); no latitudinal trends are apparent. The contribution made by bivalves and gastropods varies between 1% and 99%, north-temperate intertidal flats having relatively more molluscs than tropical flats. Intertidal flats in the tropics contain a greater variety of taxa, with brachiopods in Indonesia and echinoderms in northwest Australia contributing significantly to biomass only there. Limits to the occurrence of avian predators of intertidal benthos are set by the harvestable fraction of the biomass on offer and the costs of living at a particular site. No systematic differences in the harvestable fraction of the total mollusc-biomass for a worldwide occurring shorebird species specializing on molluscs (knots Calidris canutus) were apparent between temperate and tropical intertidal areas, in spite of large differences in maintenance metabolism incurred by these birds. The harvestable fractions of bivalves in the two West African areas (Banc d'Arguin, Mauritania and Guinea-Bissau) tended to be high (23-84% of total biomass in six species), they were relatively low (2-52% in five species) in the temperate Wadden Sea and the tropical northwest Australian site. Harvestable biomass determines the intake rate of shorebirds, as illustrated by functional-response curves of knots feeding on two bivalves species. We argue that the collection of information on size-depth relationships along with faunal and biomass surveys at a range of sites is bound to greatly increase our understanding of both the biology of tidal-flat invertebrates and the resource base underpinning the spectacular seasonal migrations of shorebirds.

  18. Developmental transcriptome of Aplysia californica'

    KAUST Repository

    Heyland, Andreas

    2010-12-06

    Genome-wide transcriptional changes in development provide important insight into mechanisms underlying growth, differentiation, and patterning. However, such large-scale developmental studies have been limited to a few representatives of Ecdysozoans and Chordates. Here, we characterize transcriptomes of embryonic, larval, and metamorphic development in the marine mollusc Aplysia californica and reveal novel molecular components associated with life history transitions. Specifically, we identify more than 20 signal peptides, putative hormones, and transcription factors in association with early development and metamorphic stages-many of which seem to be evolutionarily conserved elements of signal transduction pathways. We also characterize genes related to biomineralization-a critical process of molluscan development. In summary, our experiment provides the first large-scale survey of gene expression in mollusc development, and complements previous studies on the regulatory mechanisms underlying body plan patterning and the formation of larval and juvenile structures. This study serves as a resource for further functional annotation of transcripts and genes in Aplysia, specifically and molluscs in general. A comparison of the Aplysia developmental transcriptome with similar studies in the zebra fish Danio rerio, the fruit fly Drosophila melanogaster, the nematode Caenorhabditis elegans, and other studies on molluscs suggests an overall highly divergent pattern of gene regulatory mechanisms that are likely a consequence of the different developmental modes of these organisms. © 2010 Wiley-Liss, Inc., A Wiley Company.

  19. The evolution of mollusc shells.

    Science.gov (United States)

    McDougall, Carmel; Degnan, Bernard M

    2018-05-01

    Molluscan shells are externally fabricated by specialized epithelial cells on the dorsal mantle. Although a conserved set of regulatory genes appears to underlie specification of mantle progenitor cells, the genes that contribute to the formation of the mature shell are incredibly diverse. Recent comparative analyses of mantle transcriptomes and shell proteomes of gastropods and bivalves are consistent with shell diversity being underpinned by a rapidly evolving mantle secretome (suite of genes expressed in the mantle that encode secreted proteins) that is the product of (a) high rates of gene co-option into and loss from the mantle gene regulatory network, and (b) the rapid evolution of coding sequences, particular those encoding repetitive low complexity domains. Outside a few conserved genes, such as carbonic anhydrase, a so-called "biomineralization toolkit" has yet to be discovered. Despite this, a common suite of protein domains, which are often associated with the extracellular matrix and immunity, appear to have been independently and often uniquely co-opted into the mantle secretomes of different species. The evolvability of the mantle secretome provides a molecular explanation for the evolution and diversity of molluscan shells. These genomic processes are likely to underlie the evolution of other animal biominerals, including coral and echinoderm skeletons. This article is categorized under: Comparative Development and Evolution > Regulation of Organ Diversity Comparative Development and Evolution > Evolutionary Novelties. © 2018 Wiley Periodicals, Inc.

  20. La formación de anillos de crecimiento en Fissurella crassa en el norte de Chile

    OpenAIRE

    Marta Bretos

    1980-01-01

    Growth discontinuity in molluscs result in the formation of rings on their shells. Two kind of rings may be formed: disturbance and growth rings. Growth rings can be used to determine the age of molluscs with long life span. For this, it is necessary to know how many growth rings are formed per year. It has been demonstrated experimentally, using marked specimens, that F. crassa forms two growth rings per year at Huayquique, Northern Chile. They are formed during winter and summer. Disturbanc...

  1. La formacion de anillos de crecimiento en Fissurella crassa en el norte de Chile

    OpenAIRE

    Bretos, Marta

    1980-01-01

    Growth discontinuity in molluscs result in the formation of rings on their shells. Two kind of rings may be formed: disturbance and growth rings. Growth rings can be used to determine the age of molluscs with long life span. For this, it is necessary to know how many growth rings are formed per year. It has been demonstrated experimentally, using marked specimens, that F. crassa forms two growth rings per year at Huayquique, Northern Chile. They are formed during winter and summer. Disturbanc...

  2. Vyhodnotenie malakofauny z náplavov Neresnice (stredné Slovensko Interpretation of molluscan fauna from the Neresnica River flood deposits (Central Slovakia

    Directory of Open Access Journals (Sweden)

    Marek Čiliak

    2011-11-01

    Full Text Available Sampling of flood debris deposits can be useful method in insufficiently surveyed areas. This sampling method also allows us to detect the presence of rare and endangered species in the study area. We studied flood debris along the Neresnica River to gather data on mollusc fauna of the Pliešovská Kotlina basin and the Javorie Mts. (Central Slovakia. In spring 2010, samples of flood debris were taken at three sites along the river. Molluscan thanatocoenoses were composed of 68 species (56 terrestrial and 12 aquatic ones. The most notable records were two subterranean species – Lucilla scintilla and L. singleyana, and also the species of nature conservation interest – Vertigo angustior. We found representatives of all ecological groups of molluscs, which provide the evidence of ecosystem diversity in various habitats along the river. We documented that the land use of the studied drainage basin was only partially reflected by the structure of mollusc assemblages from flood deposits.

  3. Sub-lethal cadmium exposure increases phytochelatin concentrations in the aquatic snail Lymnaea stagnalis

    Energy Technology Data Exchange (ETDEWEB)

    SF, Gonçalves [Department of Biology & CESAM, Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro (Portugal); SK, Davies [Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ (United Kingdom); Bennett, M. [Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ (United Kingdom); Raab, A.; Feldmann, J. [TESLA, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland (United Kingdom); Kille, P. [Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3US (United Kingdom); Loureiro, S. [Department of Biology & CESAM, Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro (Portugal); DJ, Spurgeon [Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Wallingford OX10 8BB (United Kingdom); JG, Bundy, E-mail: j.bundy@imperial.ac.uk [Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ (United Kingdom)

    2016-10-15

    Phytochelatins are metal-binding metabolites found in almost all plant species and some animal groups, including nematodes and annelids, where they can play an important role in detoxifying metals such as cadmium. Species from several other taxa contain a phytochelatin synthase (PCS) gene orthologue, including molluscs, indicating they may have the potential to synthesize phytochelatins. However, the presence of a gene alone does not demonstrate that it plays a functional role in metal detoxification. In the present study, we show that the aquatic snail Lymnaea stagnalis produced both penta- and heptapeptide phytochelatins (i.e. phytochelatin-2 and phytochelatin-3), and their levels increased in response to sub-lethal levels of cadmium. - Highlights: • Little is known about the role of phytochelatins in metal detoxification in animals. • We detected phytochelatins (PC{sub 2} and PC{sub 3}) in a mollusc species, Lymnaea stagnalis. • Phytochelatins increased in Lymnaea stagnalis when exposed to cadmium. • Future research on phytochelatin responses in molluscs would be valuable.

  4. Selection and validation of a set of reliable reference genes for quantitative RT-PCR studies in the brain of the Cephalopod Mollusc Octopus vulgaris

    Directory of Open Access Journals (Sweden)

    Biffali Elio

    2009-07-01

    Full Text Available Abstract Background Quantitative real-time polymerase chain reaction (RT-qPCR is valuable for studying the molecular events underlying physiological and behavioral phenomena. Normalization of real-time PCR data is critical for a reliable mRNA quantification. Here we identify reference genes to be utilized in RT-qPCR experiments to normalize and monitor the expression of target genes in the brain of the cephalopod mollusc Octopus vulgaris, an invertebrate. Such an approach is novel for this taxon and of advantage in future experiments given the complexity of the behavioral repertoire of this species when compared with its relatively simple neural organization. Results We chose 16S, and 18S rRNA, actB, EEF1A, tubA and ubi as candidate reference genes (housekeeping genes, HKG. The expression of 16S and 18S was highly variable and did not meet the requirements of candidate HKG. The expression of the other genes was almost stable and uniform among samples. We analyzed the expression of HKG into two different set of animals using tissues taken from the central nervous system (brain parts and mantle (here considered as control tissue by BestKeeper, geNorm and NormFinder. We found that HKG expressions differed considerably with respect to brain area and octopus samples in an HKG-specific manner. However, when the mantle is treated as control tissue and the entire central nervous system is considered, NormFinder revealed tubA and ubi as the most suitable HKG pair. These two genes were utilized to evaluate the relative expression of the genes FoxP, creb, dat and TH in O. vulgaris. Conclusion We analyzed the expression profiles of some genes here identified for O. vulgaris by applying RT-qPCR analysis for the first time in cephalopods. We validated candidate reference genes and found the expression of ubi and tubA to be the most appropriate to evaluate the expression of target genes in the brain of different octopuses. Our results also underline the

  5. Spatial distribution, inter-annual variability and influence of abiotic factors on molluscan assemblages collected with otter trawl in the northen Alborán Sea

    OpenAIRE

    Ciércoles, C. (Cristina); García-Ruiz, C. (Cristina); González-Aguilar, M. (María); López-González, N. (Nieves); Tuite, P. (Patrick); Ortiz-de-Urbina-Gutiérrez, J.M. (José María); Rueda, J.L. (José Luis)

    2016-01-01

    Molluscs constitute one of the most diverse and best represented invertebrate groups in the marine environment. In the northern sectors of the Alborán Sea and Gulf of Cádiz 1200 spp. of the 1800 spp. occurring in the Mediterranean Sea, have been found so far highlighting the importance of this area for the european molluscan fauna (Gofas et al., 2011). Molluscs are also the second group in abundance and biomass in demersal fisheries and an important component of soft-bottom benthic communitie...

  6. Identification of a phenoloxidase- and melanin-dependent defence mechanism in Achatina fulica infected with Angiostrongylus vasorum.

    Science.gov (United States)

    Coaglio, Aytube Lucas; Ferreira, Mônica Alves Neves Diniz; Dos Santos Lima, Walter; de Jesus Pereira, Cíntia Aparecida

    2018-02-27

    Angiostrongylus vasorum has different freshwater aquatic and terrestrial gastropod molluscs as an intermediate host, e.g. Arion spp. The mollusc Achatina fulica is a danger to public health, given the large diversity of nematodes utilizing it as an intermediate host, such as the parasites of the genus Angiostrongylus, of importance in human and veterinary medicine. Achatina fulica has been shown to have an excellent capacity for maintaining outbreaks and natural infections with A. cantonensis in Asia. Within the mollusc, the nematode parasites activate haemocytes and/or haemolymph factors and in some invertebrates, phenoloxidase (PO), that induces the release of toxic elements and eliminates the parasites. Despite the importance of A. fulica in the life-cycle of nematodes, little is known regarding the defence mechanisms involving PO in molluscs infected with nematodes. Here, the presence of PO and nitric oxide (NO) in the haemolymph and haemocytes of A. fulica infected with first-stage (L1) larvae of Angiostrongylus vasorum was evaluated, together with the presence of melanin in the cephalopod mollusc tissue. An increase in PO at one day post infection (dpi), in comparison with the control using the substrates L-tyrosine (F (4,90)  = 6.73, P = 0.00006), L-DOPA (F (4,90)  = 22.67, P = 0.02) and p-phenylenediamine (PPD) (F (4,90)  = 27.58, P = 0.0019), was observed. PO increase coincided with the presence of melanin in the cephalopodal tissue. At 8 dpi, PO activity, compared to L-DOPA (F (4,90)  = 22.67, P = 0.00002) and PPD (F (4,90)  = 27.58, P = 0.079) decreased, while melanin increased. At 13 dpi, PO decreased with PPD (F (4,90)  = 27.58, P = 0.000015) and also the amount of melanin observed in histology. At 30 dpi, PO increased along with the substrates L-DOPA and PPD, while melanin decreased. NO levels increased until 8 dpi, and decreased after 13 dpi. To our knowledge, this is the first study that

  7. Transfer factors of trace elements and radionuclides in the marine environment of India

    International Nuclear Information System (INIS)

    Desai, M.V.M.; Pulhani, Vandana; Padmanabhan, Hemalatha

    1998-11-01

    The document presents the data base on Bioaccumulation Factor, B p and Distribution Coefficient, K d values generated in the eastern and western coastal marine waters of India with a view to develop site-specific or species-specific values. Comparison with the IAEA default values from Safety Series No. 57 and Technical Report Series No. 247 values is made. Generally, the B p values for trace elements do not vary by more than a factor of 3 except for some specific cases like Fe in molluscs, crustaceans and fish, Ni in molluscs and Zn in sea weeds and molluscs. The same is true for the B p values of fission nuclides viz., 137 Cs and 90 Sr in molluscs, crustaceans and sea weeds except for the B p of 137 Cs in fish which is significantly lower in the Indian context. The fission nuclide 144 Ce shows distinctly higher accumulation factors in all organisms. The B p values of natural radionuclides such as 210 Pb , 210 Po, Ra and U are close to the IAEA default values except for the high value of U in fish. Similarly, B p values of Pu in fish and crustaceans are significantly higher than that of the IAEA default values. The report presents B p values for Cu and Cd in different marine organisms and K d values in marine sediments. K d values for suspended particles are also presented. B p values for plankton and porifera are also given. (author)

  8. Vodní měkkýši bývalého lomu Chabařovice v severních Čechách

    Directory of Open Access Journals (Sweden)

    Luboš Beran

    2010-11-01

    Full Text Available This paper completes the knowledge of aquatic molluscs of a former coal quarry Chabařovice near Ústí nad Labem in Northern Bohemia. This quarry was opened in 1977 and 20 years later the mining was finished. A part of the coal quarry was flooded and new water reservoir Milada originated in the area of 250 ha with max. depth 24,7 m and this water reservoir is the biggest aquatic habitat in this area. Other four smaller water reservoirs, numerous drainage canals and small wetlands were built and aquatic molluscs of these sites were studied in 2010. Altogether, 16 species of aquatic molluscs (12 gastropods, 4 bivalves were found at 41 sites. Drainage canals, new brooks and small new wetlands are inhabited by poor aquatic malacofauna which contains often only one or two widespread species – Galba truncatula and Radix auricularia. Bivalve Pisidium casertanum was found only at three sites. Similar situation is in the case of water reservoirs Rabenov and Roudníky. Only artifical water reservoir Milada and smaller water reservoir close to this lake are inhabited by rich aquatic malacofauna containing 14 respectively 6 species. Molluscs were studied also in the past before opening the quarry and the actual malacofauna is richer probably due to the existence of more aquatic habitats. Three non-native species were found and the occurrence of other non native species is expected in the future as well as changes in autochtonous malacofauna.

  9. Last interglacial marine environments in the White Sea region, northern Russia

    DEFF Research Database (Denmark)

    Grøsfjeld, Kari; Funder, Svend; Seidenkrantz, Marit-Solveig

    2006-01-01

    Marine sediments from river sections in the Mezen River drainage, northwest Russia, have been analysed for dinoflagellate cysts, foraminifers and molluscs. The sediments were dated by pollen analysis and by reference to the local sea-level history, and are Late Saalian to late Eemian (c. 133 to 119...... water was stronger and probably penetrated further eastwards than at present. The molluscs, dinoflagellate cysts and foraminifers reflect the warmer than present conditions and that the optimum temperature occurred at the time of the early Eemian global sea-level rise. Around 128 kyr BP, the eustatic...

  10. Shell extracts of the edible mussel and oyster induce an enhancement of the catabolic pathway of human skin fibroblasts, in vitro.

    Science.gov (United States)

    Latire, Thomas; Legendre, Florence; Bouyoucef, Mouloud; Marin, Frédéric; Carreiras, Franck; Rigot-Jolivet, Muriel; Lebel, Jean-Marc; Galéra, Philippe; Serpentini, Antoine

    2017-10-01

    Mollusc shells are composed of more than 95% calcium carbonate and less than 5% organic matrix consisting mostly of proteins, glycoproteins and polysaccharides. In this study, we investigated the effects of matrix macromolecular components extracted from the shells of two edible molluscs of economic interest, i.e., the blue mussel Mytilus edulis and the Pacific oyster Crassostrea gigas. The potential biological activities of these organic molecules were analysed on human dermal fibroblasts in primary culture. Our results demonstrate that shell extracts of the two studied molluscs modulate the metabolic activities of the cells. In addition, the extracts caused a decrease of type I collagen and a concomitant increase of active MMP-1, both at the mRNA and the protein levels. Therefore, our results suggest that shell extracts from M. edulis and C. gigas contain molecules that promote the catabolic pathway of human dermal fibroblasts. This work emphasises the potential use of these shell matrices in the context of anti-fibrotic strategies, particularly against scleroderma. More generally, it stresses the usefulness to valorise bivalve shells that are coproducts of shellfish farming activity.

  11. Cuantificación de metales pesados en Anadara tuberculosa(Mollusca:bivalvia del estero Huaylá de Puerto Bolívar, por espectrofotometría de absorción atómica

    Directory of Open Access Journals (Sweden)

    Collaguazo-Collaguazo, Yadira

    2017-09-01

    Full Text Available The presence of heavy metals in bivalve molluscs implies a serious problem for the consumers health of this type of food. Therefore, the objective of the present investigation was to determine the presence of heavy metals in Anadara tuberculosa, mollusc of commercial importance at Puerto Bolívar, Ecuador. Atomic absorption spectrophotometry was the method used to quantify the concentration of heavy metals. The concentration of six metals was determined: lead (Pb, arsenic (As, mercury (Hg, cadmium (Cd, chromium (Cr and cobalt (Co. The average values obtained, expressed in mg.kg-1 were: Pb (7.52 ± 0.46; As (1.55 ± 0.14; Hg (364.38 ± 91.39; Cd (1.68 ± 0.28; Cr (3,89 ± 1,82 and Co (2,71 ± 0,34 in A. tuberculosa The results show that Pb, As, Cd, and Hg exceed the maximum permissible limits, mercury exceeds by more than 100 times the limit value. The smaller size (3-4 cm studied mollusc, has the capacity to bioaccumulate higher concentration of Pb, Cd and Cr.

  12. The Role of the Cephalopod Digestive Gland in the Storage and Detoxification of Marine Pollutants

    Directory of Open Access Journals (Sweden)

    Pedro M. Costa

    2017-04-01

    Full Text Available The relevance of cephalopods for fisheries and even aquaculture, is raising concerns on the relationship between these molluscs and environmental stressors, from climate change to pollution. However, how these organisms cope with environmental toxicants is far less understood than for other molluscs, especially bivalves, which are frontline models in aquatic toxicology. Although, sharing the same basic body plan, cephalopods hold distinct adaptations, often unique, as they are active predators with high growth and metabolic rates. Most studies on the digestive gland, the analog to the vertebrate liver, focused on metal bioaccumulation and its relation to environmental concentrations, with indication for the involvement of special cellular structures (like spherulae and proteins. Although the functioning of phase I and II enzymes of detoxification in molluscs is controversial, there is evidence for CYP-mediated bioactivation, albeit with lower activity than vertebrates, but this issue needs yet much research. Through novel molecular tools, toxicology-relevant genes and proteins are being unraveled, from metallothioneins to heat-shock proteins and phase II conjugation enzymes, which highlights the importance of increasing genomic annotation as paramount to understand toxicant-specific pathways. However, little is known on how organic toxicants are stored, metabolized and eliminated, albeit some evidence from biomarker approaches, particularly those related to oxidative stress, suggesting that these molluscs' digestive gland is indeed responsive to chemical aggression. Additionally, cause-effect relationships between pollutants and toxicopathic effects are little understood, thus compromising, if not the deployment of these organisms for biomonitoring, at least understanding how they are affected by anthropogenically-induced global change.

  13. Role of olfaction in Octopus vulgaris reproduction.

    Science.gov (United States)

    Polese, Gianluca; Bertapelle, Carla; Di Cosmo, Anna

    2015-01-01

    The olfactory system in any animal is the primary sensory system that responds to chemical stimuli emanating from a distant source. In aquatic animals "Odours" are molecules in solution that guide them to locate food, partners, nesting sites, and dangers to avoid. Fish, crustaceans and aquatic molluscs possess sensory systems that have anatomical similarities to the olfactory systems of land-based animals. Molluscs are a large group of aquatic and terrestrial animals that rely heavily on chemical communication with a generally dispersed sense of touch and chemical sensitivity. Cephalopods, the smallest class among extant marine molluscs, are predators with high visual capability and well developed vestibular, auditory, and tactile systems. Nevertheless they possess a well developed olfactory organ, but to date almost nothing is known about the mechanisms, functions and modulation of this chemosensory structure in octopods. Cephalopod brains are the largest of all invertebrate brains and across molluscs show the highest degree of centralization. The reproductive behaviour of Octopus vulgaris is under the control of a complex set of signal molecules such as neuropeptides, neurotransmitters and sex steroids that guide the behaviour from the level of individuals in evaluating mates, to stimulating or deterring copulation, to sperm-egg chemical signalling that promotes fertilization. These signals are intercepted by the olfactory organs and integrated in the olfactory lobes in the central nervous system. In this context we propose a model in which the olfactory organ and the olfactory lobe of O. vulgaris could represent the on-off switch between food intake and reproduction. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Deep-ocean disposal of high-activity nuclear wastes: a conservative assessment of the seafood critical pathway

    International Nuclear Information System (INIS)

    Baxter, M.S.; Economides, B.

    1984-01-01

    This paper applies conventional 'worst-case' assumptions to modelling the effects of possible future disposal of high-activity wastes in the oceans. It otherwise uses previously published and generally accepted data to assess the possible intakes of the waste nuclides via consumption of seaweeds, molluscs, crustaceans, plankton and fish. Model-predicted intakes for critical groups generally exceed ICRP-recommended limits, with 244 Cm, 241 Am and 137 Cs being the most potentially hazardous nuclides. The various seafood consumption pathways are found to rank, in decreasing order of potential hazard, as seaweeds > molluscs > plankton > fish > crustaceans. (Auth.)

  15. MOLLUSKS IN RADIOECOLOGICAL STUDIES OF FRESHWATER ECOSYSTEMS

    Directory of Open Access Journals (Sweden)

    Д. Гудков

    2012-04-01

    Full Text Available Species-specificity and dynamics of 90Sr, 137Cs and some transuraniс elements accumulation in bivalveand gastropod freshwater molluscs of the Chernobyl exclusion zone during 1998–2010 was analyzed. Theresults of radiation dose as well as chromosome aberration rate estimation and analysis of hemolymphcomposition of molluscs was produced. The radiation absorbed dose rate was registered in the range of 0.3–85.0 μGy h–1. In closed water bodies the heightened chromosome aberration rate (up to 27 % in embryotissues, and also change of haematological indexes for the adult individuals of snails was registered

  16. Strontium-90 in the western Gulf of Mexico

    International Nuclear Information System (INIS)

    Payton, P.H.; Hild, S.B.; Oertti, C.U.; Suttle, A.D. Jr.

    1977-01-01

    The results of measurements of 90 Sr in water, coral, hermit crabs and molluscs from the western Gulf of Mexico and in fresh water molluscs from Canyon Lake, Texas are reported. Preparation of samples for measurement in the anticoincidence mode in a lead shielded flow proportional counter is described. The measured value of 0.095 +- 0.003 pCi/litre for Gulf water is in accord with literature values. Concentration factors for 90 Sr are apparently 1 for coral. The activity incorporated into shells normalized to calcium content, decreases from Galveston to Campeche Bay. (U.K.)

  17. Experimental evidence for inherent Lévy search behaviour in foraging animals.

    Science.gov (United States)

    Kölzsch, Andrea; Alzate, Adriana; Bartumeus, Frederic; de Jager, Monique; Weerman, Ellen J; Hengeveld, Geerten M; Naguib, Marc; Nolet, Bart A; van de Koppel, Johan

    2015-05-22

    Recently, Lévy walks have been put forward as a new paradigm for animal search and many cases have been made for its presence in nature. However, it remains debated whether Lévy walks are an inherent behavioural strategy or emerge from the animal reacting to its habitat. Here, we demonstrate signatures of Lévy behaviour in the search movement of mud snails (Hydrobia ulvae) based on a novel, direct assessment of movement properties in an experimental set-up using different food distributions. Our experimental data uncovered clusters of small movement steps alternating with long moves independent of food encounter and landscape complexity. Moreover, size distributions of these clusters followed truncated power laws. These two findings are characteristic signatures of mechanisms underlying inherent Lévy-like movement. Thus, our study provides clear experimental evidence that such multi-scale movement is an inherent behaviour rather than resulting from the animal interacting with its environment. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  18. BIOTECHNOLOGY IN THE STUDY OF MOLLUSCS

    Directory of Open Access Journals (Sweden)

    Christopher J. Bayne

    2012-09-01

    Full Text Available The optimization of conditions and media for the in vitro culture of molluscan cells have yielded advances such that primary cultures can now be maintained for weeks or months. With one exception, molluscan cells have proven refractory to the establishment of continous cell lines. Knowledge derived from these studies has helped investigators maintain and grow intramolluscan parasites in vitro.Recent advances in cell fusion, cell cloning and transfection of oncogenes have yet to be applied in molluscan cell culture. Once established, future cell lines will permit a great variety of studies including the control of gene expression, post-transcriptional processing including glycosylation, and the produc­tion in quantity of molluscan factors such as lectins, hormoned, immunogenic macromolecules and others of interest. In addition these lines will also facilitate screening for molluscan viruses and other cellular pathogens, and the propagation of these putative agents of biological control. Such cell lines would also permit the study of molecular mechanisms of drug and hormone actions, and the rational design of drugs.Molecular genetic protocols have been restricted so far to studies of evolution and systematics within molluscan taxa. Both RNA and DNA probes are being developed from ribosomal, mitochondrial and nuclear compartments. Both direct sequencing and restriction length polymorphisms detected using endonucleases are yielding useful data.

  19. Optimizing a method for detection of hepatitis A virus in shellfish and study the effect of gamma radiation on the viral genome

    International Nuclear Information System (INIS)

    Amri, Islem

    2008-01-01

    Our work was aimed at detecting the hepatitis A virus (HAV) in bivalve mollusc collected from five shellfish harvesting areas and from a coastal region in Tunisia using RT-Nested-PCR and studying the effect of gamma radiation on HAV genome. Two methods used to recover HAV from mollusc flesh and two methods of extraction of virus RNA were compared in order to determine the most sensitive method. Glycine extraction and extraction of virus RNA using proteinase K were more convenient and then used in this study for detection of HAV in shellfish. The results of molecular analyses: RT-Nested-PCR using primers targeted at the P1 region revealed that 28 % of the samples were positive for HAV. Doses of gamma irradiation ranging between 5 to 30 kGy were used to study the effect of this radiation on HAV genome after the contamination of mollusc flesh with suspension of HAV (derived from stool specimens). HAV specific genomic band was observed for doses between 5 to 20 kGy. We didn't detect HAV genome with doses 25 and 30 kGy. (Author)

  20. Influence of the Bottom Sediment Characteristics on the Bivalve Mollusk Anadara kagoshimensis Histopathology's Variability in the Northeastern Coast of the Black Sea

    Science.gov (United States)

    Kolyuchkina, G. A.; Budko, D. F.; Chasovnikov, V. K.; Chzhu, V. P.

    2017-11-01

    With increasing anthropogenic impact on the environment, investigations of organism's response to the contamination of natural habitats, are especially relevant. In the present study, we sought to identify the correlation between the bottom sediments and local variability in histopathology of Anadara kagoshimensis (Bivalvia) in four sites of the north-eastern coast of the Black Sea. Bottom sediment grain size, redox potential of pore water, heavy metals, benzo-α-pyrene and DDT concentrations have been used as characteristics of bottom sediments. Analysis of the data revealed differences in the geochemical background of the studied sites and the histopathological state of the molluscs from these areas. Among the 10 studied elements as well as benzo-α-pyrene and DDT, only Ni has shown an exceedance of statutory limits of concentration in bottom sediments. The study reveals a relationship between Ni concentration in the bottom sediments and frequency of heavy histopathologies in the molluscs. In addition to causes directly related to pollution, mild pathology may be influenced by "natural" causes; in particular, the high content of brown cells in the connective tissue of the digestive gland may be due to the age of molluscs.

  1. Reconstructing diet composition on the basis of faeces in a mollusc-eating wader, the Knot Calidris canutus

    NARCIS (Netherlands)

    Dekinga, A.; Piersma, T.

    1993-01-01

    Methods are described to assess the molluscan diet of Knots feeding on intertidal flats in western Europe from their faecal output. The size distributions of two common bivalve prey, Macoma balthica and Cerastoderma edule, can be estimated from the heights of shell hinges retrieved from droppings.

  2. Concentration of PSP (Paralytic Shellfish Poisoning) Toxin On Shellfish From Inner Ambon Bay and Kao Bay North Halmahera

    Science.gov (United States)

    Pello, F. S.; Haumahu, S.; Huliselan, N. V.; Tuapattinaja, M. A.

    2017-10-01

    The Inner Ambon Bay and Kao Bay have potential on fisheries resources which one of them is molluscs. Molluscs especially for class bivalve have economical values and are consumed by coastal community. The research had been done to analyze saxitoxin (STX) concentration on bivalves from Kao Bay and Inner Ambon Bay. The Saxitoxin Elisa Test Kit Protocol was used to determine saxitoxin concentration. The measurement showed that the highest concentration of saxitoxin (392.42 µg STXeq/100g shellfish meat) was Gafrarium tumidum from Ambon Bay, whereas concentration of saxitoxin (321.83 µg STXeq/100g shellfish meat) was Mactra mera from Kao Bay

  3. Intertidal oysters reach their physiological limit in a future high-CO2 world.

    Science.gov (United States)

    Scanes, Elliot; Parker, Laura M; O'Connor, Wayne A; Stapp, Laura S; Ross, Pauline M

    2017-03-01

    Sessile marine molluscs living in the intertidal zone experience periods of internal acidosis when exposed to air (emersion) during low tide. Relative to other marine organisms, molluscs have been identified as vulnerable to future ocean acidification; however, paradoxically it has also been shown that molluscs exposed to high CO 2 environments are more resilient compared with those molluscs naive to CO 2 exposure. Two competing hypotheses were tested using a novel experimental design incorporating tidal simulations to predict the future intertidal limit of oysters in a high-CO 2 world; either high-shore oysters will be more tolerant of elevated P CO 2 because of their regular acidosis, or elevated P CO 2  will cause high-shore oysters to reach their limit. Sydney rock oysters, Saccostrea glomerata , were collected from the high-intertidal and subtidal areas of the shore and exposed in an orthogonal design to either an intertidal or a subtidal treatment at ambient or elevated P CO 2 , and physiological variables were measured. The combined treatment of tidal emersion and elevated P CO 2  interacted synergistically to reduce the haemolymph pH (pH e ) of oysters, and increase the P CO 2  in the haemolymph ( P e,CO 2 ) and standard metabolic rate. Oysters in the intertidal treatment also had lower condition and growth. Oysters showed a high degree of plasticity, and little evidence was found that intertidal oysters were more resilient than subtidal oysters. It is concluded that in a high-CO 2 world the upper vertical limit of oyster distribution on the shore may be reduced. These results suggest that previous studies on intertidal organisms that lacked tidal simulations may have underestimated the effects of elevated P CO 2 . © 2017. Published by The Company of Biologists Ltd.

  4. Committed effective dose from naturally occuring radionuclides in shellfish

    Science.gov (United States)

    Khandaker, Mayeen Uddin; Wahib, Norfadira Binti; Amin, Yusoff Mohd.; Bradley, D. A.

    2013-07-01

    Recognizing their importance in the average Malaysian daily diet, the radioactivity concentrations in mollusc- and crustacean-based food have been determined for key naturally occuring radionuclides. Fresh samples collected from various maritime locations around peninsular Malaysia have been processed using standard procedures; the radionuclide concentrations being determined using an HPGe γ-ray spectrometer. For molluscs, assuming secular equilibrium, the range of activities of 238U (226Ra), 232Th (228Ra) and 40K were found to be 3.28±0.35 to 5.34±0.52, 1.20±0.21 to 2.44±0.21 and 118±6 to 281±14 Bq kg-1 dry weight, respectively. The respective values for crustaceans were 3.02±0.57 to 4.70±0.52, 1.38±0.21 to 2.40±0.35 and 216±11 to 316±15 Bq kg-1. The estimated average daily intake of radioactivity from consumption of molluscs are 0.37 Bq kg-1 for 238U (226Ra), 0.16 Bq kg-1 for 232Th (228Ra) and 18 Bq kg-1 for 40K; the respective daily intake values from crustaceans are 0.36 Bq kg-1, 0.16 Bq kg-1 and 23 Bq kg-1. Associated annual committed effective doses from molluscs are estimated to be in the range 21.3 to 34.7 μSv for 226Ra, 19.3 to 39.1 μSv for 228Ra and 17.0 to 40.4 μSv for 40K. For crustaceans, the respective dose ranges are 19.6 to 30.5 μSv, 22.0 to 38.4 μSv and 31.1 to 45.5 μSv, being some several times world average values.

  5. La formación de anillos de crecimiento en Fissurella crassa en el norte de Chile

    Directory of Open Access Journals (Sweden)

    Marta Bretos

    1980-12-01

    Full Text Available Growth discontinuity in molluscs result in the formation of rings on their shells. Two kind of rings may be formed: disturbance and growth rings. Growth rings can be used to determine the age of molluscs with long life span. For this, it is necessary to know how many growth rings are formed per year. It has been demonstrated experimentally, using marked specimens, that F. crassa forms two growth rings per year at Huayquique, Northern Chile. They are formed during winter and summer. Disturbance ring formation has also been observed as a result of sawing marks on their shells. A growth curve for this species is proposed on the basis of Walford's line.

  6. Biokinetic behavior of Tc in the red abalone, Haliotis rufescens: a reassessment

    International Nuclear Information System (INIS)

    Beasley, T.M.; Lorz, H.V.; Gonor, J.J.

    1981-01-01

    The biokinetic behavior of /sup 95m/Tc in the red abalone, Haliotis rufescens, is reviewed in light of recent experiments on other molluscs. Additional experimentation has confirmed that, when uptake is directly from labeled seawater, abalone exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics cannot be described by a single compartment model as had been previously advanced. Assimilation of /sup 95m/Tc by the abalone following a single feeding of labeled macroalga, Nereocystis pyrifera, is high (approx. 45%) and loss kinetics are similar to those observed following direct uptake from seawater

  7. Uptake and metabolism of 14C-chloropyrifos by marine bivalves

    International Nuclear Information System (INIS)

    Zhong, C.G.; Chen, S.; Zhao, X.; Shi, J.; Carvalho, F.P.

    1999-01-01

    The uptake and metabolism of 14 C-chlorpyrifos by two marine bivalves, Paphia undulata and Sinonovacula constricta, were studied in a simulated ecosystem. The experiments were carried out in two 30 L glass tanks containing each 20 L of filtered sea water, contaminated with 14 C-chlorpyrifos 1.85x10 4 Bq.L -1 (16.7 μg.L -1 ) at the beginning of the exposure period. At different time intervals, three specimens of each species were sampled for analysis of the pesticide in the molluscs tissues. The 14 C-chlorpyrifos residues were extracted from the digestive gland of the molluscs and analyzed by co-chromatography with pesticide standards by TLC methods described before

  8. Biokinetic behavior of technetium in the red abalone, Haliotis rufescens: a re-assessment

    Energy Technology Data Exchange (ETDEWEB)

    Beasley, T.M.; Lorz, H.V.; Gonor, J.J. (Oregon State Univ., Newport (USA). Marine Science Center)

    1982-10-01

    The biokinetic behavior of sup(95m)Tc in the red abalone, haliotis rufescens, is reviewed in light of recent experiments with other molluscs. Additional experimentation has confirmed that, when uptake is directly from labeled seawater, abalones exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics in the abalone cannot be described by a single compartment model as had been previously advanced. Assimilation of sup(95m)Tc by abalones following a single feeding of labeled macroalga, Nereocystis luetkeana, approximately equal to 45% and loss kinetics are similar to those observed following direct uptake from seawater.

  9. Biokinetic behavior of technetium in the red abalone, Haliotis rufescens: a re-assessment

    Energy Technology Data Exchange (ETDEWEB)

    Beasley, T.M.; Lorz, H.V.; Gonor, J.J.

    1982-10-01

    The biokinetic behavior of /sup 95m/Tc in the red abalone, Haliotis rufescens, is reviewed in light of recent experiments with other molluscs. Additional experimentation has confirmed that, when uptake is directly from labelled seawater, abalones exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics in the abalone cannot be described by a single compartment model as had been previously advanced. Assimilation of /sup 95m/Tc by abalones following a single feeding of labeled macroalga, Nereocystis luetkeana, is approximately 45% and loss kinetics are similar to those observed following direct uptake from seawater.

  10. Biokinetic behavior of technetium in the red abalone, Haliotis rufescens: a re-assessment

    International Nuclear Information System (INIS)

    Beasley, T.M.; Lorz, H.V.; Gonor, J.J.

    1982-01-01

    The biokinetic behavior of sup(95m)Tc in the red abalone, haliotis rufescens, is reviewed in light of recent experiments with other molluscs. Additional experimentation has confirmed that, when uptake is directly from labeled seawater, abalones exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics in the abalone cannot be described by a single compartment model as had been previously advanced. Assimilation of sup(95m)Tc by abalones following a single feeding of labeled macroalga, Nereocystis luetkeana, approximately equal to 45% and loss kinetics are similar to those observed following direct uptake from seawater. (author)

  11. Parasite communities: patterns and processes

    National Research Council Canada - National Science Library

    Esch, Gerald W; Bush, Albert O; Aho, John M

    1990-01-01

    .... Taking examples from many hosts including molluscs, marine and freshwater fish, amphibians, reptiles, birds and mammals, this book shows how parasitic communities are influenced by a multitude...

  12. Acute toxicities of crude oils and oil-dispersant mixtures to Red sea fishes and invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Eisler, R.

    1975-11-01

    Crude oil from fields in the Persian Gulf and in the Sinai plus a chemical oil dispersant were tested, using static bioassay procedures, for toxicity to adults or juveniles of ten marine species: Heteroxenia fuscescens, a soft coral; Nerita forskali and Drupa granulata, gastropod molluscs; Mytilus variabilis, a mussel; Acanthopleura haddoni, a chiton (mollusc); Echinometra mathaei, sea urchin; Calcinus latens, a hermit crab; Palaemon pacificus, a shrimp; Parupeneus barberinus, goatfish; and Siganus rivulatus, rabbitfish. Concentrations fatal to 50 percent of individual test species in 168 hours, LC-50 (168 h), ranged from 0.74 to more than 30.0 ml/liter for Persian Gulf crude, from 14.5 to more than 30.0 ml/liter for Sinai crude, and from 0.006 to 0.064 ml/liter for the dispersant. In general, fishes and crustaceans were the most sensitive groups assayed and molluscs the most resistant. LC-50 (168 h) values for oil-dispersant mixtures of 10 parts oil to 1 part dispersant (v/v) for selected species ranged from 0.047 to 0.152 ml/liter which appears to reflect the biocidal properties of the dispersant. Some individuals that survived immersion in high concentrations of the test compounds for 168 h were adversely affected during treatment and afterwards.

  13. Freshwater gastropods in the Northern littoral mesoregion of Espírito Santo, Brazil

    Directory of Open Access Journals (Sweden)

    Marco Antônio Andrade de Souza

    2017-09-01

    Full Text Available Studies on the distribution of molluscs in Brazilhave been conducted since the beginning of the twentieth and the knowledge of the species distributed in the country represent important findings, which contribute to the understanding of human diseases and those of veterinary importance, transmitted by them. In order to verify the distribution of freshwater gastropods in Espírito Santo, a malacological surveywas carried out in nine municipalities that comprise the Northern mesoregion of the State, between January 2010 and February 2015. Initially the water collections occurring in the municipality were verified and the lotic systems at different levels of use and conservation were determined. Molluscs were collected monthly using a hand net adapted to a stick steel. An individual sample effort of 30 minutes was applied, by scanning, at about ten meters in each one of the selected habitats. A total of 6,000 specimens were collected, represented by genera Melanoides, Drepanotrema, Physa, Biomphalaria and Pomacea. Among the molluscs, some specimens were positive for flatworm larvae of medical and veterinary importance. The results contributed to the knowledge of the current distribution of freshwater gastropods in the Northern region of Espírito Santo whose the only record for the region dates back to 1983.

  14. Antimicrobial and antioxidant activities of ethyl acetate and methanol extracts of Littorina littorea and Galatea paradoxa

    Directory of Open Access Journals (Sweden)

    Lawrence Sheringham Borquaye

    2016-12-01

    Full Text Available The aquatic environment is a vital resource for bioprospecting pharmacologically important natural products. Molluscs are known to harbour compounds with antimicrobial, antitumor and antioxidant activities. This study evaluated the antimicrobial and antioxidant properties of ethyl acetate and methanol tissue extracts of two molluscs, Littorina littorea (L. littorea and Galatea paradoxa (G. paradoxa. Agar diffusion and broth dilution assays were used to test for antimicrobial activity against nine microbes. The 1,1-diphenyl-2-picrylhydrazyl (DPPH method was used to determine antioxidant activity of the extracts. Extracts of both molluscs showed significant activity against all the bacteria strains tested but were inactive towards the fungus. The best antibacterial activity was recorded by methanol extract of L. littorea towards Pseudomonas aeruginosa. In comparison to ethyl acetate extracts, methanol extracts were more efficient in scavenging the DPPH radical. Methanol extracts of L. littorea had an IC50 of 0.37 mg/mL which was closer to that of the standard ascorbic acid drug (0.0048 mg/mL than any of the other extracts. The findings of this work indicate that the tissue extracts of L. littorea and G. paradoxa are promising sources of antimicrobial and antioxidant agents that can be utilized for pharmaceutical and nutraceutical purposes.

  15. First report of endosymbionts in Dreissena polymorpha from the brackish Curonian Lagoon, SE Baltic Sea

    Directory of Open Access Journals (Sweden)

    Romualda Chuševė

    2012-11-01

    Full Text Available We report the first results of a parasitological study ofDreissena polymorpha (zebra mussels from the brackishCuronian Lagoon, SE Baltic Sea. Zebra mussels were collected monthlyfrom May to October 2011 from a site near the mouth of the River Nemunas.Three types of endosymbionts were found in the mantle cavity andvisceral mass of the molluscs during dissections, i.e. thecommensal ciliate Conchophthirus acuminatus and parasitic ciliateOphryoglena sp., and rarely encountered, unidentified nematodes.The abundances of C. cuminatus and Ophryoglena sp.were positively associated with host shell length and watertemperature, but no effect of water salinity was detected.As the endosymbionts are either highly host-specific to zebra mussels(C. acuminatus and Ophryoglena sp. or are probablyfree-living organisms that inadvertently infect the molluscs (nematodes,we conclude that the presence of D. polymorpha in theCuronian Lagoon does not pose any serious parasitologicalrisk to native biota. We emphasize, however, that this conclusionshould be treated with caution as it is based on a study conductedonly at a single location. Our work extends the currentlyscarce records of D. polymorpha parasites and commensals frombrackish waters, and adds to a better understanding of the ecologicalimpact this highly invasive mollusc causes in the areas it has invaded.

  16. Dentalium beads - shells of fosillised sea molluscs at the Vinča-Belo brdo site

    Directory of Open Access Journals (Sweden)

    Dimitrijević Vesna

    2010-01-01

    Full Text Available During excavation of the Vinča-Belo Brdo site a significant number of decorated items made from clay, stone, bone, and seashells or snail shells have been collected over the years. Amongst the decorated objects which could be classified as jewellery the majority are bracelets, pendants, and beads made from Spondylus and Glycymeris shells, as well as beads made from Dentalium shells. The appearance of these beads and the question of their origin have not yet been specifically considered within studies of prehistoric cultures in the central Balkans. Furthermore, they have rarely been illustrated and mentioned in archaeological site inventories, which we presume has not been because of their poor representation, but rather because of their being unfamiliar. The aim of this work is therefore to: a systematize data about Dentalium beads from all phases of excavation of the Belo Brdo site in Vinča; b to show the importance of this kind of jewellery in the study of resources around the Vinča settlement; and c to indicate the wider chronological perspective and the significance of studying Dentalium beads within the prehistory of the central Balkans. Dentalium is a carnivorous Scaphopoda sea mollusc, uncommon and insufficiently studied. Representatives of this class of Scaphopoda have been found on Serbian territory in the Badenian sediments, deposited fifteen million years ago. Badenian sediments were discovered around Loznica, Belgrade, Aranđelovac, Golubac, Zaječar, and Negotin. The region of Belgrade and the surrounding area had been covered by a warm, shallow sea of normal salination. On the territory of Belgrade, offsprings of the Badenian sediments, rich in fossils, have been discovered in the city centre (Tašmajdan, Kalemegdan, as well as in many surrounding places (Rakovica, Kaluđerica, Leštani, and Jajinci (fig. 2. Scaphopod shells found at the Vinča-Belo Brdo archaeological site are usually transversally broken. Judging by the basic

  17. About application of method of atomic and absorption spectroscopy for investigation of large di cuspid mollusks as test-object of environmental conditions in Zaragshan pool

    International Nuclear Information System (INIS)

    Izzatulaev, Z.I.

    1999-01-01

    The knowledge of water ecosystems evolution laws requires for thorough investigations of chemical and elementary composition of aquatic organisms and the environment, which is of a great importance for the regions affected by technical factors influence. Therefore, we started investigating the large di cuspid molluscs as water bio filters for the first time.The investigations were conducted using different species of mollusks of Unionid and Korbikulid tribes.Contents of lead, zinc, cadmium, copper, magnesium, iron, chrome and mercury in the molluscs were determined using atomic and absorption spectrophotometer. High content of microelements in soft tissues and shell limestone is explained by the fact that they are directly absorbed in the food chain.The investigations data are not final. The investigations will be conducted in the future

  18. Deep-sea disposal: Protecting fish and man

    International Nuclear Information System (INIS)

    Hagen, A.

    1988-01-01

    The definition of radioactive waste unsuitable for dumping at sea is based on the protection of man. See IAEA Safety Series No. 78. The development of criteria for assessing the impact on deep sea marine organisms at the population level has been attempted in a report recently published by the IAEA. See IAEA Technical Reports Series, No. 228 (1988). The report indicates that certain radionuclides may give rise to high dose rates to marine organisms if dumping is carried out with the assumptions of instantaneous release at the sea floor and dumping over long periods of time. In the report, a hypothetical dose rate to molluscs from zinc-65, which poses no significant harm to man, has the potential for giving high doses to bottom-dwelling molluscs

  19. Travel report Mauritania bivalve Molluscs october 2008

    NARCIS (Netherlands)

    Poelman, M.

    2008-01-01

    During the last four years Mauritania has been working on the completion of a Food Safety Program of Bivalve Mollusks, in order to obtain an export approval by the Europe Union. During the preparations for an inspection by the FVO (Food and Veterinary Office) no fisheries or production activities

  20. Early development of the aplacophoran mollusc Chaetoderma

    DEFF Research Database (Denmark)

    Nielsen, Claus; Haszprunar, Gerhard; Ruthensteiner, Bernhard

    2007-01-01

    The early development of the trochophore larva of the aplacophoran Chaetoderma nitidulum (Mollusca: Caudofoveata = Chaetodermomorpha) is described using scanning and transmission electron microscopy and using fluorescence staining and confocal laser scanning microscopy of the muscle system...

  1. Hábito alimentar e osteologia da boca do peixe-rei, Odontesthes humensis de Buen (Atheriniformes, Atherinopsidae na Lagoa Mirim, Rio Grande do Sul, Brasil Feeding habits and mouth osteology of silverside, Odontesthes humensis de Buen (Atheriniformes, Atherinopsidae in the Mirim Lagoon, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Fábio Lameiro Rodrigues

    2001-09-01

    Full Text Available Gut contents of 304 individuals of the silverside Odontesthes humensis de Buen, 1953 were analyzed using frequency of occurrence (FO% and gravimetric (P% methods. A total of 207 individuals (68.1% had some food itens in the gut, while 97 individuals (31.9% had empty guts. The silverside Odontesthes humensis has presented a benthic carnivorous diet, preying mainly on molluscs and arthropods. The molluscs Heleobia sp. (FO = 61.35% and Corbicula fluminea (Müller, 1774 (FO = 57.97% were the most frequent itens, followed by Neocorbicula limosa (Maton, 1811 (FO = 17.39%. Among the arthropods, the coleoptera insects (FO= 18.84% were dominant followed by, insect larvae (FO = 6.76%, the crustacean Palaemonetes argentinus Nobili, 1901 (FO = 1.93% and isopods (FO = 1.45%. Vegetal remains, organic matter and digested fish were grouped due to low frequency (FO = 9.13% being considered occasional. Juvenile fed mainly on insect larvae and moluscs, while the adults preferred molluscs and coleoptera. On the description of its feeding apparatus the importance of a protrusible upper jaw was observed, being important on the capture of prey in inaccessible places. A protrusible mouth and the format of the pharingean plates, are important morphological characters that assist on the capture and handling of prey. The molariform shaped pharingean teeth help break hard food items, as shells and carapaces.

  2. River Floodplains as Habitat and Bio-Corridors for Distribution of Land Snails: Their Past and Present

    Directory of Open Access Journals (Sweden)

    Horáčková Jitka

    2015-12-01

    Full Text Available River floodplains of Czech rivers serve as refugia to woodland or hydrophilous gastropods, in current intensively agriculturally utilised, urbanised and largely fragmented landscape. This habitat often form one of the last refuge and replace the natural habitat of these species. River floodplains also represent linear bio-corridors in landscape and allow gastropods to spread through the landscape in both directions, up and down the stream. We showed based on available fossil mollusc successions that development of the floodplain mollusc fauna took place quite different way in various river floodplains, depending on their specifics and geographical location, because especially the ones situated in the chernozem area of the Czech Republic had very different history in comparison with those in higher altitudes. The species richness and composition of recent floodplain malacofauna arises from historical development of particular area/site and depends also on environmental factors such as an elevation, humidity gradient, vegetation type and its biomass, light conditions of the site and soil reaction. Recently, the invasive plants represent a serious problem for current floodplain ecosystems; species richness and abundances of terrestrial mollusc floodplain assemblages are changing due to their effect. The impact on gastropods is species-specific and was described for the following species: Impatiens glandulifera, Fallopia japonica subsp. japonica, F. sachalinensis, F. ×bohemica.

  3. The presence of APGWamide in Octopus vulgaris: a possible role in the reproductive behavior

    NARCIS (Netherlands)

    Di Cristo, C.; van Minnen, J.; Di Cosmo, A.

    2005-01-01

    The concerted action of many neuropeptides has been implicated in the nervous control of specific behaviors in many molluscs. In the present study, the presence of amidated tetrapeptide Ala-Pro-Gly-Trp-NH

  4. Studies on the diet of various lobster species have shown ...

    African Journals Online (AJOL)

    spamer

    However, the proportion of the population feeding showed marked seasonal trends at both sites, tracking the commercial ..... The general diet of crustaceans, molluscs and echino- .... habits of polychelid lobsters in the Western Mediterranean.

  5. No substantial changes in estrogen receptor and estrogen-related receptor orthologue gene transcription in Marisa cornuarietis exposed to estrogenic chemicals.

    Science.gov (United States)

    Bannister, Richard; Beresford, Nicola; Granger, David W; Pounds, Nadine A; Rand-Weaver, Mariann; White, Roger; Jobling, Susan; Routledge, Edwin J

    2013-09-15

    Estrogen receptor orthologues in molluscs may be targets for endocrine disruptors, although mechanistic evidence is lacking. Molluscs are reported to be highly susceptible to effects caused by very low concentrations of environmental estrogens which, if substantiated, would have a major impact on the risk assessment of many chemicals. The present paper describes the most thorough evaluation to-date of the susceptibility of Marisa cornuarietis ER and ERR gene transcription to modulation by vertebrate estrogens in vivo and in vitro. We investigated the effects of estradiol-17β and 4-tert-Octylphenol exposure on in vivo estrogen receptor (ER) and estrogen-related receptor (ERR) gene transcription in the reproductive and neural tissues of the gastropod snail M. cornuarietis over a 12-week period. There was no significant effect (p>0.05) of treatment on gene transcription levels between exposed and non-exposed snails. Absence of a direct interaction of estradiol-17β and 4-tert-Octylphenol with mollusc ER and ERR protein was also supported by in vitro studies in transfected HEK-293 cells. Additional in vitro studies with a selection of other potential ligands (including methyl-testosterone, 17α-ethinylestradiol, 4-hydroxytamoxifen, diethylstilbestrol, cyproterone acetate and ICI182780) showed no interaction when tested using this assay. In repeated in vitro tests, however, genistein (with mcER-like) and bisphenol-A (with mcERR) increased reporter gene expression at high concentrations only (>10(-6)M for Gen and >10(-5)M for BPA, respectively). Like vertebrate estrogen receptors, the mollusc ER protein bound to the consensus vertebrate estrogen-response element (ERE). Together, these data provide no substantial evidence that mcER-like and mcERR activation and transcript levels in tissues are modulated by the vertebrate estrogen estradiol-17β or 4-tert-Octylphenol in vivo, or that other ligands of vertebrate ERs and ERRs (with the possible exception of genistein and

  6. No substantial changes in estrogen receptor and estrogen-related receptor orthologue gene transcription in Marisa cornuarietis exposed to estrogenic chemicals☆☆☆

    Science.gov (United States)

    Bannister, Richard; Beresford, Nicola; Granger, David W.; Pounds, Nadine A.; Rand-Weaver, Mariann; White, Roger; Jobling, Susan; Routledge, Edwin J.

    2013-01-01

    Estrogen receptor orthologues in molluscs may be targets for endocrine disruptors, although mechanistic evidence is lacking. Molluscs are reported to be highly susceptible to effects caused by very low concentrations of environmental estrogens which, if substantiated, would have a major impact on the risk assessment of many chemicals. The present paper describes the most thorough evaluation to-date of the susceptibility of Marisa cornuarietis ER and ERR gene transcription to modulation by vertebrate estrogens in vivo and in vitro. We investigated the effects of estradiol-17β and 4-tert-Octylphenol exposure on in vivo estrogen receptor (ER) and estrogen-related receptor (ERR) gene transcription in the reproductive and neural tissues of the gastropod snail M. cornuarietis over a 12-week period. There was no significant effect (p > 0.05) of treatment on gene transcription levels between exposed and non-exposed snails. Absence of a direct interaction of estradiol-17β and 4-tert-Octylphenol with mollusc ER and ERR protein was also supported by in vitro studies in transfected HEK-293 cells. Additional in vitro studies with a selection of other potential ligands (including methyl-testosterone, 17α-ethinylestradiol, 4-hydroxytamoxifen, diethylstilbestrol, cyproterone acetate and ICI182780) showed no interaction when tested using this assay. In repeated in vitro tests, however, genistein (with mcER-like) and bisphenol-A (with mcERR) increased reporter gene expression at high concentrations only (>10−6 M for Gen and >10−5 M for BPA, respectively). Like vertebrate estrogen receptors, the mollusc ER protein bound to the consensus vertebrate estrogen-response element (ERE). Together, these data provide no substantial evidence that mcER-like and mcERR activation and transcript levels in tissues are modulated by the vertebrate estrogen estradiol-17β or 4-tert-Octylphenol in vivo, or that other ligands of vertebrate ERs and ERRs (with the possible exception of

  7. Zooplankton biomass and composition in the western Bay of Bengal during late sw monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.; Madhupratap, M.; Nair, V.R.; Nair, S.R.S.; Rao, T.S.S.

    and neritic regions of the southwestern Bay of Bengal. Other groups like chaetognaths, ostracods, amphipods, euphausiids, fish eggs, fish larvae, polychaetes, cladocerans, planktonic molluscs, etc. contributed to a lesser percentage of the general composition...

  8. Carbonate mineralogy and faunal relationship in tropical shallow water marine sediments: Cape Comorin, India

    Digital Repository Service at National Institute of Oceanography (India)

    Hashimi, N.H.; Nair, R.R.; Kidwai, R.M.; Rao, V.P.

    molluscs exceed other components, as on the eastern shelf between 10 and 40 m, the most abundant mineral is aragonite. Low-magnesium calcite does not appear to be related to depth or carbonate components...

  9. Middle to Late Ordovician faunal studies from central Australia and Tasmania during the Great Ordovician Biodiversification Event

    DEFF Research Database (Denmark)

    Jakobsen, Kristian Grube

    A profound transformation of the marine biosphere took place during the Great Ordovician Biodiversification Event (GOBE), recognized as the longest interval of sustained biodiversification in the history of life. Successions through the Middle Ordovician Stairway Sandstone of the Amadeus Basin......, but the diversity is generally relatively low. The bivalves are the most dominant and diverse group in the central Australian fauna, whereas the brachiopods are the most dominant and diverse group in the Tasmanian fauna. Thirteen trilobite, five brachiopod, four conodont and 22 mollusc taxa have been documented......, but the preservation and low number of specimens prevent formal definition of additional new taxa. Although highly endemic at species level, the investigated brachiopod, trilobite and mollusc faunas display a high degree of overall similarity at generic level with Middle Ordovician faunas from North China. Other...

  10. Harpacticoida (Crustacea, Copepoda of Mussel Beds and Macroalgae on the Rocky Substrates in the North-Western Black Sea

    Directory of Open Access Journals (Sweden)

    Portianko V. V.

    2017-10-01

    Full Text Available The role of harpacticoid copepods in total abundance, biomass and species diversity of meiobenthos on rocky substrates is described. Th e fauna of harpacticoid copepods consists of 19 species in algal beds, 23 species in mussel beds and 24 species in mixed aggregation of molluscs and macrophytes. In the macrophyte aggregation, the maximal abundance was registered in Cladophora vagabunda - 88 750 ind. × m-2, while minimal was on Laurensia paniculata - 8250 ind. × m-2. According to the frequency of occurrence, the habitat preferred by copepods was Ceramium elegans, but according to their percentage in total meiobenthos among macrophytes it was Ulva intestinalis, 56.6 %. The percentage of copepods in the pure mussel beds was higher comparing to mixed aggregation of molluscs and macrophytes.

  11. A preliminary report on the distribution and relative abundance of Euthecosomata with a note on the seasonal variation of Limacina species in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Sakthivel, M.

    Euthecosomata (holoplanktonic opisthobranch molluscs) sorted out from the collections of the International Indian Ocean Expedition are now being studied and the present communication is a first report based on an examination of material from 395...

  12. A documentation on burrows in hard substrates of ferromanganese crusts and associated soft sediments from the Central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R

    , which are extensively bioturbated. Both the ferromanganese-coated and uncoated relict burrows have been collected from the same locality. Mobile epibenthic megafauna, e.g. molluscs, echinoderms, etc. seem to be main bioturbating organisms. The adjacent...

  13. Developmental transcriptome of Aplysia californica'

    KAUST Repository

    Heyland, Andreas; Vue, Zer; Voolstra, Christian R.; Medina, Mó nica; Moroz, Leonid L.

    2010-01-01

    developmental transcriptome with similar studies in the zebra fish Danio rerio, the fruit fly Drosophila melanogaster, the nematode Caenorhabditis elegans, and other studies on molluscs suggests an overall highly divergent pattern of gene regulatory mechanisms

  14. Soft sediment dwelling macro-invertebrates of Rajapur Bay, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Harkantra, S.N.; Parulekar, A.H.

    Thirtyfour species of soft sediment dwelling macro-invertebrates were recorded in Rajapur Bay at the proposed effluent discharge location of nuclear power plant. The fauna mainly composed of polychaetes (42.52%), molluscs (39.03%), crustaceans (7...

  15. Long-term lead accumulation in abalone (Haliotis spp. ) fed on lead-treated brown algae (Egregia laevigata)

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, J; Schulz-Baldes, M

    1976-01-01

    In this study we assessed the amount of lead accumulated in the body of a grazing mollusc by transfer from its algal food in laboratory experiments, and compared these results with the amounts found in naturally occurring molluscs and seaweed. Near La Jolla, California (USA), where the concentration of lead in seawater is probably less than 0.08 ..mu..g 1/sup -1/, most of the naturally occurring Egregia laevigata contains less than 0.4 ..mu..g Pb g/sup -1/ wet weight. The total body masses, without shells, of juvenile Haliotis rufescens fed on this seaweed for 3 to 6 months showed similar concentrations. When, however, E. laevigata is placed for 1 to 6 days in seawater to which lead has been added (0.1 or 1.0 mg 1/sup -1/) both the seaweed and the abalone subsequently fed with it accumulate proportionally larger amounts of lead. After 6 months, young abalone fed on E. laevigata pretreated with 1.0 mg Pb 1/sup -1/ accumulated up to 21 ..mu..g Pb g/sup -1/ wet weight. This amount of lead had no apparent consequences on the growth or activity of the molluscs. Analyses of 6 different organs from adult abalone showed that the lead was selectively concentrated in the digestive gland. In the foot (muscle tissue), which is the part normally consumed by humans, only negligible amounts were found.

  16. Climate warming reduces fish production and benthic habitat in Lake Tanganyika, one of the most biodiverse freshwater ecosystems

    Science.gov (United States)

    Cohen, Andrew S.; Gergurich, Elizabeth L.; Kraemer, Benjamin M.; McGlue, Michael M.; McIntyre, Peter B.; Russell, James M.; Simmons, Jack D.; Swarzenski, Peter W.

    2016-01-01

    Warming climates are rapidly transforming lake ecosystems worldwide, but the breadth of changes in tropical lakes is poorly documented. Sustainable management of freshwater fisheries and biodiversity requires accounting for historical and ongoing stressors such as climate change and harvest intensity. This is problematic in tropical Africa, where records of ecosystem change are limited and local populations rely heavily on lakes for nutrition. Here, using a ∼1,500-y paleoecological record, we show that declines in fishery species and endemic molluscs began well before commercial fishing in Lake Tanganyika, Africa’s deepest and oldest lake. Paleoclimate and instrumental records demonstrate sustained warming in this lake during the last ∼150 y, which affects biota by strengthening and shallowing stratification of the water column. Reductions in lake mixing have depressed algal production and shrunk the oxygenated benthic habitat by 38% in our study areas, yielding fish and mollusc declines. Late-20th century fish fossil abundances at two of three sites were lower than at any other time in the last millennium and fell in concert with reduced diatom abundance and warming water. A negative correlation between lake temperature and fish and mollusc fossils over the last ∼500 y indicates that climate warming and intensifying stratification have almost certainly reduced potential fishery production, helping to explain ongoing declines in fish catches. Long-term declines of both benthic and pelagic species underscore the urgency of strategic efforts to sustain Lake Tanganyika’s extraordinary biodiversity and ecosystem services.

  17. The anatomy of the serotonergic nervous system of an entoproct creeping-type larva and its phylogenetic implications

    DEFF Research Database (Denmark)

    Wanninger, Andreas Wilhelm Georg; Fuchs, Judith; Haszprunar, Gerhard

    2007-01-01

    the anatomy of the serotonergic nervous system of the creeping-type larva of Loxosomella murmanica. The apical organ is very complex and comprises six to eight centrally positioned flask cells and eight bipolar peripheral cells. In addition, a prototroch nerve ring, an anterior nerve loop, a paired buccal...... molluscs and may be diagnostic for a mollusc-entoproct clade. In addition, the larva of Loxosomella expresses a mosaic of certain neural features that are also found in other larval or adult Spiralia, e.g., a prototroch nerve ring, an anterior nerve loop, and a buccal nervous system....... ones, are found along the anterior-posterior axis. The combination of a complex larval serotonergic apical organ and (adult) tetraneury, comprising one pair of ventral and one pair of more dorsally situated lateral longitudinal nerve cords without ganglia, has so far only been reported for basal...

  18. THE BAFFIN BAY REGION DURING THE LAST INTERGLACIATION: EVIDENCE FROM NORTHWEST GREENLAND

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1989-01-01

    Coastal sections in the Thule area, northwest Greenland, provide a recordof last interglacial glacial and oceanographic events on the northern perimeter of Baffin Bay. The record is dated by a combination of thermoluminescence and 14C dating; local and regional correlation is provided by amino acid...... for the last nterglacial/glacial cycle was attained during Middle Sangamonian times, and a smaller advance took place in the Late Wisconsinan. In beween ice coverage was similar to the present, or smaller. The record provides a link between events in Arctic Canada and northern Greenland, and shows...... analyses of mollusc shells, and periods of penetration by warm subarctic water have been identified by their foraminifera and mollusc faunas. Subarclic water reached the area on three occasions: during the Holocene, and in the Early and Late Sangamonian. Maximum, although restricted, ice coverage...

  19. Feeding habits of Barbul de piedra (ariopsis sp.) in the Sinu River, Colombia

    International Nuclear Information System (INIS)

    Olaya Nieto, Charles W; Arellano Padilla, John J; Martinez Gonzalez, Angel L

    2012-01-01

    The feeding habits of Barbul de piedra in the Sinu River were studied. the stomach content was analyzed using the proportion of empty stomachs, grade of digestion, frequency of occurrence, numerical frequency, gravimetry, relative importance index and the gut length total length relationship. Only 18.8% of stomachs were empty, most of preys were half digested and five food groups were identified: crustaceans, fishes, vegetable rests, molluscs and others. Crustaceans were the most frequent, abundant and greater weight composition group. The relative importance index indicated that crustaceans and fishes were secondary relative importance groups and vegetable rests, molluscs and others were occasional or circumstantial groups. The results achieved in this work indicate that Barbul de piedra is a fish that keeps your feeding habits as they grow and along the hydrological cycle, although shows carnivorous preference, especially by crustaceans.

  20. New caulerpenyne-derived metabolites of an Elysia Sacoglossan from the south Indian coast

    Digital Repository Service at National Institute of Oceanography (India)

    Ciavatta, M.L.; Gresa, M.P.L.; Gavagnin, M.; Manzo, E.; Mollo, E.; DeSouza, L.; Cimino, G.

    and Caulerpa has also been demonstrated by chemical studies [6], while there is a lack of chemical information about the Indo-Pacific species that seems to have similar alimentary habits. The ability of Caulerpa-feeder molluscs to transform dietary...

  1. Biological geography of the European seas: results from the MacroBen database

    NARCIS (Netherlands)

    Arvanitidis, C.; Somerfield, P.J.; Rumohr, H.; Faulwetter, S.; Valavanis, V.; Vasileiadou, A.; Chatzigeorgiou, G.; Vanden Berghe, E.; Vanaverbeke, J.; Labrune, C.; Grémare, A.; Zettler, M.L.; Kedra, M.; Wlodarska-Kowalczuk, M.; Aleffi, I.F.; Amouroux, J.M.; Anisimova, N.; Bachelet, G.; Büntzow, M.; Cochrane, S.J.; Costello, M.J.; Craeymeersch, J.A.; Dahle, S.; Degraer, S.; Denisenko, S.; Dounas, C.; Duineveld, G.; Emblow, C.; Escavarage, V.; Fabri, M.C.; Fleischer, D.; Gray, J.S.; Heip, C.H.R.; Herrmann, M.; Hummel, H.; Janas, U.; Karakassis, I.; Kendall, M.A.; Kingston, P.; Kotwicki, L.; Laudien, J.; Mackie, A.S.Y.; Nevrova, E.L.; Occhipinti-Ambrogi, A.; Oliver, P.G.; Olsgard, F.; Palerud, R.; Petrov, A.; Rachor, E.; Revkov, N.K.; Rose, A.; Sardá, R.; Sistermans, W.C.H.; Speybroeck, J.; Van Hoey, G.; Vincx, M.; Whomersley, P.; Willems, W.; Zenetos, A.

    2009-01-01

    This study examines whether or not biogeographical and/or managerial divisions across the European seas can be validated using soft-bottom macrobenthic community data. The faunal groups used were: all macrobenthos groups, polychaetes, molluscs, crustaceans, echinoderms, sipunculans and the last 5

  2. Regional differences in the lateral mobility of plasma membrane lipids in a molluscan embryo

    NARCIS (Netherlands)

    Speksnijder, J.E.; Dohmen, M.R.; Tertoolen, L.G.J.; Laat, S.W. de

    1985-01-01

    Regional and temporal differences in plasma membrane lipid mobility have been analyzed during the first three cleavage cycles of the embryo of the polar-lobe-forming mollusc Nassarius reticulatus by the fluorescence photobleaching recovery (FPR) method, using 1,1′-ditetradecyl

  3. Benthic life on the tropical sandy shore: Miramar beach a case study

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.

    of shore-dwelling bivalve molluscs. The foot of intertidal and subtidal clams such as Mactra violacea and Meretrix spp. is relatively large and powerful. It can pull the shell below the sand surface very quickly symbolising the burrowing life style. Other...

  4. Characteristics of nearshore waters in Binge Bay, Karwar

    Digital Repository Service at National Institute of Oceanography (India)

    Zingde, M.D.; Singbal, S.Y.S.

    was observed. Levels of soluble Mn, Fe, Cu and Zn were on the lower side of the range observed for the Arabian Sea. Concentrations of some trace metals in marine algae, fishes, crustaceans and molluscs are also reported and discussed...

  5. Isozyme Variation in Two Samples of Babylonia areolata from Southeast Asia

    DEFF Research Database (Denmark)

    Nguyen, T. X. T.; Nugranad, J.; Simonsen, V.

    2001-01-01

    Hylleberg, J. (Ed.) Proceedings of the 11th International Congress & Workshop of the Tropical Marine Mollusc Programme (TMMP), Kodaikanal, Rameswaram and Tuticorin Tamilnadu, India, 28th September- 8th October 2000. Part 1. Tuticorin, India: Sugnthi Devadason Marine Research Institute (SDMRI...

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

    NARCIS (Netherlands)

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

    1985-01-01

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

  7. Validation of the OECD reproduction test guideline with the New Zealand mudsnail Potamopyrgus antipodarum using trenbolone and prochloraz

    DEFF Research Database (Denmark)

    Geiss, Cornelia; Ruppert, Katharina; Askem, Clare

    2017-01-01

    The Organisation for Economic Cooperation and Development (OECD) provides several standard test methods for the environmental hazard assessment of chemicals, mainly based on primary producers, arthropods, and fish. In April 2016, two new test guidelines with two mollusc species representing...

  8. Caribbean land molluscs: Bulimulidae II. Plekocheilus and Naesiotus

    NARCIS (Netherlands)

    Breure, A.S.H.

    1975-01-01

    The second part of this series on the Bulimulidae deals with the genera Plekocheilus Guilding and Naesiotus Albers, two and six species of which are recognized respectively. The following new synonymy is proposed: Bulimulus chrysaloides Pilsbry = Naesiotus chrysalis (Pfeiffer). Bulimulus

  9. Committed effective dose from naturally occuring radionuclides in shellfish

    International Nuclear Information System (INIS)

    Khandaker, Mayeen Uddin; Wahib, Norfadira Binti; Amin, Yusoff Mohd.; Bradley, D.A.

    2013-01-01

    Recognizing their importance in the average Malaysian daily diet, the radioactivity concentrations in mollusc- and crustacean-based food have been determined for key naturally occuring radionuclides. Fresh samples collected from various maritime locations around peninsular Malaysia have been processed using standard procedures; the radionuclide concentrations being determined using an HPGe γ-ray spectrometer. For molluscs, assuming secular equilibrium, the range of activities of 238 U ( 226 Ra), 232 Th ( 228 Ra) and 40 K were found to be 3.28±0.35 to 5.34±0.52, 1.20±0.21 to 2.44±0.21 and 118±6 to 281±14 Bq kg −1 dry weight, respectively. The respective values for crustaceans were 3.02±0.57 to 4.70±0.52, 1.38±0.21 to 2.40±0.35 and 216±11 to 316±15 Bq kg −1 . The estimated average daily intake of radioactivity from consumption of molluscs are 0.37 Bq kg −1 for 238 U ( 226 Ra), 0.16 Bq kg −1 for 232 Th ( 228 Ra) and 18 Bq kg −1 for 40 K; the respective daily intake values from crustaceans are 0.36 Bq kg −1 , 0.16 Bq kg −1 and 23 Bq kg −1 . Associated annual committed effective doses from molluscs are estimated to be in the range 21.3 to 34.7 μSv for 226 Ra, 19.3 to 39.1 μSv for 228 Ra and 17.0 to 40.4 μSv for 40 K. For crustaceans, the respective dose ranges are 19.6 to 30.5 μSv, 22.0 to 38.4 μSv and 31.1 to 45.5 μSv, being some several times world average values. - Highlights: ► Activity concentrations of naturally occuring radionuclides were assessed for shellfish. ► 238 U, 232 Th, 40 K intake via shellfish showed several times higher than world averages. ► Committed effective doses due to the ingestions of 238 U, 232 Th, 40 K are the first report in Malaysia. ► Estimated committed effective dose also showed higher values than the world average

  10. Molecular and morphological identification of larval opecoelids (Digenea: Opecoelidae) parasitising prosobranch snails in a Western Mediterranean lagoon

    Czech Academy of Sciences Publication Activity Database

    Born-Torrijos, A.; Kostadinova, Aneta; Raga, J. A.; Holzer, Astrid S.

    2012-01-01

    Roč. 61, č. 3 (2012), s. 450-460 ISSN 1383-5769 R&D Projects: GA ČR GAP505/10/1562; GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : ITS rDNA * 28S rDNA * morphology * Life-cycle * Opecoelidae * Cainocreadium labracis * Macvicaria obovata * Gibbula adansonii * Western Mediterranean Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.302, year: 2012

  11. The ibero-balearic region: one of the areas of highest Hydrobiidae (Gastropoda, Prosobranchia, Rissooidea diversity in Europe

    Directory of Open Access Journals (Sweden)

    Arconada, Beatriz

    2003-12-01

    Full Text Available The prosobranch mollusc family Hydrobiidae Troschel, 1857 has a cosmopolitan distribution and is made up of small to minute species that inhabit permanent aquatic ecosystems. It is one of the largest families within the superfamily Rissooidea. The evolutionary relationships between members of this family are still unclear due to: 1 insufficient available information regarding the morphological characters of many of the described taxa, 2 uncertainty concerning which morphological characters are of greatest taxonomic and phylogenetic interest, and 3 the rare use of molecular characters to study evolutionary relationships. In this work, we examine the reasons for the confusing systematics of hydrobiids. We include a diagnosis of the 13 genera and a list of the 43 species described and accepted to date for the Ibero-balearic region, along with data regarding their geographic distribution and a compilation of the most relevant bibliographical references. The Iberian Peninsula is one of the areas of greatest hydrobiid diversity in Europe, and has a large number of endemic genera and species in addition to those that have a typically circummediterranean distribution. Numerous hydrobiid species and populations are threatened, and in some cases, in danger of extinction due to the fragile nature of many of the ecosystems they inhabit.

    La familia Hydrobiidae Troschel, 1857 de moluscos prosobranquios, tiene distribución cosmopolita y está constituida por especies de tamaño pequeño (o incluso diminuto que habitan ecosistemas acuáticos permanentes. Se trata de una de las familias con mayor número de especies de la superfamilia Rissooidea. Las relaciones evolutivas entre los miembros de esta familia son aún confusas debido a: (1 la insuficiente información disponible sobre los caracteres morfológicos de muchos de los táxones descritos, (2 la indefinición de los caracteres morfológicos de interés taxonómico y filogenético, y (3 la escasa

  12. Lateral mobility of plasma membrane lipids in a molluscan egg: Evidence for an animal/vegetal polarity

    NARCIS (Netherlands)

    Laat, S.W. de; Speksnijder, J.E.; Dohmen, M.R.; Zoelen, E. van; Tertoolen, L.G.J.; Bluemink, J.G.

    1984-01-01

    The lateral diffusion of the lipid analog C₁₄-diI (3', 3'-dihexadecylindocarbocyanine iodide) was measured in the plasma membrane of early embryos of the mollusc Nassarius reticulatus using the FPR-(Fluorescence Photobleaching Recovery) method. At almost all stages measured (from

  13. Effects of Seawater Acidification on the Liffe Cycle and Fitness of Opossum Shrimp Population

    Science.gov (United States)

    Much of the current concern about ecological effects of ocean acidification focuses on molluscs and coccolithophores because of their importance in the global calcium cycle. However, many other marine organisms are likely to be affected by acidification because of their known se...

  14. Effects of Seawater Acidification on the Life Cycle and fitness of Opossum Shrimp Populations

    Science.gov (United States)

    Much of the current concern about ecological effects of ocean acidification focuses on molluscs and coccolithophores because of their importance in the global calcium cycle. However, many other marine organisms are likely to be affected by acidification because of their known ph...

  15. Assessment and rehabilitation of wildlife affected by an oil spill in Puerto Rico

    International Nuclear Information System (INIS)

    Mignucci-Giannoni, A.A.

    1999-01-01

    On 7 January 1994, the barge Morris J. Berman spilled approximately 3.6 million liters of oil off Punta Escambron in San Juan, Puerto Rico. This resulted in the contamination of extensive areas, impacting on natural resources along more than 48 km of Puerto Rico's north shore. Thousands of dead and alive oiled organisms washed ashore. Dead wildlife were collected opportunistically, and examined for the presence of oil and identified. Live wildlife was cleaned and treated at a temporary triage facility. A total of 5687 organisms of over 152 species were collected, including cnidarians, annelids, crustaceans, molluscs, echinoderms, fishes, birds and sea turtles. Molluscs and echinoderms were noticeably more affected than other species. Four species classified as endangered or threatened were also affected. A significant impact was observed on the live specimens presented for medical treatment, including shore crabs, birds and sea turtles. Only 63% of these were successfully rehabilitated. (author)

  16. Baseline growth and reproductive parameters in Lymnaea stagnalis for OECD test guideline development: optimization of diets and culturing conditions

    DEFF Research Database (Denmark)

    Holbech, Henrik; Hutchinson, Tom

    laboratories in Denmark, Germany and the UK for the OECD pre-validation work to date. Laboratory cultures of L. stagnalis are traditionally fed fresh (preferably organic) lettuce; however, interrupted supplies of fresh lettuce in some countries in 2011 highlighted a potential problem for the draft OECD test...... of a mollusc reproduction test guideline. An ad hoc mollusc expert group has been formed in Europe to validate methods that can meet this need. Currently, a key species for use in this context is the freshwater gastropod Lymnaea stagnalis. An important aspect of this work is to first develop a specific...... pathogen free defined strain of L. stagnalis and second to establish a historical database of growth and reproductive rates under defined culturing conditions. A mass culture of the RENILYS® strain of L. stagnalis have been established at INRA (France) since 2002 and has been distributed to research...

  17. Diagenetic changes in Concholepas concholepas shells (Gastropoda, Muricidae) in the hyper-arid conditions of Northern Chile - implications for palaeoenvironmental reconstructions

    Science.gov (United States)

    Guzmán, N.; Dauphin, Y.; Cuif, J. P.; Denis, A.; Ortlieb, L.

    2009-02-01

    Variations in the chemical composition of fossil biogenic carbonates, and in particular of mollusc shells, have been used in a range of palaeoenvironmental reconstructions. It is of primary importance, therefore, to detect and understand the diagenetic processes that may modify the original chemical signature. This microstructural and biogeochemical study focuses on modern and fossil (Holocene and Pleistocene) shells of a littoral gastropod of Northern Chile, and on the characterization of mineral component transformations at the nanometric scale and concomitant intracrystalline organic compound modifications. The inner aragonite layer of the shell exhibits more complex deteriorations than the calcite layer. This preliminary study confirms that physical and chemical alterations of various components of mollusc shell biocrystals are complex and might manifest in different ways even within a single individual. The single criterion of determining the mineralogical composition to verify the conservation state of shell samples is insufficient.

  18. Diagenetic changes in Concholepas concholepas shells (Gastropoda, Muricidae in the hyper-arid conditions of Northern Chile – implications for palaeoenvironmental reconstructions

    Directory of Open Access Journals (Sweden)

    L. Ortlieb

    2009-02-01

    Full Text Available Variations in the chemical composition of fossil biogenic carbonates, and in particular of mollusc shells, have been used in a range of palaeoenvironmental reconstructions. It is of primary importance, therefore, to detect and understand the diagenetic processes that may modify the original chemical signature. This microstructural and biogeochemical study focuses on modern and fossil (Holocene and Pleistocene shells of a littoral gastropod of Northern Chile, and on the characterization of mineral component transformations at the nanometric scale and concomitant intracrystalline organic compound modifications. The inner aragonite layer of the shell exhibits more complex deteriorations than the calcite layer. This preliminary study confirms that physical and chemical alterations of various components of mollusc shell biocrystals are complex and might manifest in different ways even within a single individual. The single criterion of determining the mineralogical composition to verify the conservation state of shell samples is insufficient.

  19. THE MOLLUSCAN FAUNA FROM THE UPPER PLEISTOCENE VERTEBRATE-BEARING DEPOSITS OF S. TEODORO CAVE (NORTH-EASTERN SICILY

    Directory of Open Access Journals (Sweden)

    DANIELA ESU

    2007-03-01

    Full Text Available This paper deals with terrestrial, freshwater and marine molluscs collected in the upper Pleistocene deposits of clay, sands and gravels of S. Teodoro Cave (North-eastern Sicily. Beginning from 1998 two trenches have been excavated (1998 and 2002-2004. A highly diversified assemblage of endemic and not endemic vertebrates (elephant, horse, wild ox, deer, wild boar, hyaena, fox, mouse, ground vole, shrew, hedgehog, bats, birds, reptiles, invertebrates (molluscs and vegetal remains have been collected from the two trenches. The molluscan fauna is represented by poor to rich-species assemblages of land and freshwater gastropods and bivalves with Mediterranean-European character. Some species have been found for the first time as fossils in Sicily. The land snails prevail in the 1998 trench showing a persistent arid environment during the time of the sediment deposition. The freshwater species, characteristic of slow-running water, point to the presence of a small water body (stream or spring inside the cave, probably more consistent in the 2002-2004 trench where this fauna prevails. The dispersal of the molluscan fauna of S. Teodoro Cave from the mainland during the low stand sea-level phases of the upper Pleistocene probably belongs to the same dispersal events following the Oxygen Isotope Stage 5e which introduced into the island not endemic faunal elements which are associated with endemic faunal elements in S. Teodoro Cave. Littoral marine reworked molluscs found in the cave deposits probably come from the sedimentary cover of a middle Pleistocene terrace which overlies the roof of the cave. SHORT NOTE

  20. Direct dating of fossils by the helium-uranium method

    International Nuclear Information System (INIS)

    Schaeffer, O.A.

    1967-01-01

    The He-U method has been found to be applicable to the dating of fossil carbonates. This method furnishes a new dating technique particularly applicable to the Pleistocene and the Tertiary periods, especially the Late Tertiary, for which other methods of age dating either fail or are difficult to correlate with the fossil record. The method has been checked for possible losses of helium and uranium from or to the surroundings. It has been found that, while a calcite lattice does not appear to retain helium, if the lattice is aragonite there is good evidence that helium leakage is not a problem. This is true at least for times up to 20 m. y. For corals where the uranium is apparently uniformly distributed within the lattice as a trace element, the uranium does not exchange or undergo concentration changes. As a result aragonite corals yield reliable He-U ages. On the other hand, the uranium in mollusc fossils is apparently mainly in the grain boundaries and is not always a tight system as far as uranium exchange or concentration changes are concerned. To obtain a reliable age for a mollusc one needs additional evidence to ensure lack of changes in uranium concentration. If the measurement of U and He is combined with 238 U, 234 U and 230 Th determinations, it appears that many mollusc shells will also be datable by the method. The resulting evidence for secular equilibrium in the 238 U chain is good evidence for a closed system as far as U concentration changes are concerned. (author)

  1. Prolonged Permian Triassic ecological crisis recorded by molluscan dominance in Late Permian offshore assemblages.

    Science.gov (United States)

    Clapham, Matthew E; Bottjer, David J

    2007-08-07

    The end-Permian mass extinction was the largest biotic crisis in the history of animal life, eliminating as many as 95% of all species and dramatically altering the ecological structure of marine communities. Although the causes of this pronounced ecosystem shift have been widely debated, the broad consensus based on inferences from global taxonomic diversity patterns suggests that the shift from abundant brachiopods to dominant molluscs was abrupt and largely driven by the catastrophic effects of the end-Permian mass extinction. Here we analyze relative abundance counts of >33,000 fossil individuals from 24 silicified Middle and Late Permian paleocommunities, documenting a substantial ecological shift to numerical dominance by molluscs in the Late Permian, before the major taxonomic shift at the end-Permian mass extinction. This ecological change was coincident with the development of fluctuating anoxic conditions in deep marine basins, suggesting that numerical dominance by more tolerant molluscs may have been driven by variably stressful environmental conditions. Recognition of substantial ecological deterioration in the Late Permian also implies that the end-Permian extinction was the climax of a protracted environmental crisis. Although the Late Permian shift to molluscan dominance was a pronounced ecological change, quantitative counts of 847 Carboniferous-Cretaceous collections from the Paleobiology Database indicate that it was only the first stage in a stepwise transition that culminated with the final shift to molluscan dominance in the Late Jurassic. Therefore, the ecological transition from brachiopods to bivalves was more protracted and complex than their simple Permian-Triassic switch in diversity.

  2. Prolonged Permian–Triassic ecological crisis recorded by molluscan dominance in Late Permian offshore assemblages

    Science.gov (United States)

    Clapham, Matthew E.; Bottjer, David J.

    2007-01-01

    The end-Permian mass extinction was the largest biotic crisis in the history of animal life, eliminating as many as 95% of all species and dramatically altering the ecological structure of marine communities. Although the causes of this pronounced ecosystem shift have been widely debated, the broad consensus based on inferences from global taxonomic diversity patterns suggests that the shift from abundant brachiopods to dominant molluscs was abrupt and largely driven by the catastrophic effects of the end-Permian mass extinction. Here we analyze relative abundance counts of >33,000 fossil individuals from 24 silicified Middle and Late Permian paleocommunities, documenting a substantial ecological shift to numerical dominance by molluscs in the Late Permian, before the major taxonomic shift at the end-Permian mass extinction. This ecological change was coincident with the development of fluctuating anoxic conditions in deep marine basins, suggesting that numerical dominance by more tolerant molluscs may have been driven by variably stressful environmental conditions. Recognition of substantial ecological deterioration in the Late Permian also implies that the end-Permian extinction was the climax of a protracted environmental crisis. Although the Late Permian shift to molluscan dominance was a pronounced ecological change, quantitative counts of 847 Carboniferous–Cretaceous collections from the Paleobiology Database indicate that it was only the first stage in a stepwise transition that culminated with the final shift to molluscan dominance in the Late Jurassic. Therefore, the ecological transition from brachiopods to bivalves was more protracted and complex than their simple Permian–Triassic switch in diversity. PMID:17664426

  3. A geographical information system for the management of the aquaculture data in the Adriatic Sea – the Strengthening of Centres for Aquaculture Production and Safety surveillance in the Adriatic countries experience: Present capabilities, tools and functions

    Directory of Open Access Journals (Sweden)

    Susanna Tora

    2017-11-01

    Full Text Available The European Commission (EC regulation no. 854/2004 requires a systematic monitoring of chemical and microbiological contaminants in live bivalve molluscs, live echinoderms, live tunicates and live marine gastropods for human consumption through surveillance plans to be implemented in all European Union (EU countries.A consortium of five Adriatic countries was set up in the framework of the Instrument of Pre-accession Assistance Adriatic Cross-border Cooperation Programme (IPA Adriatic CBC 2007- 2013 with the aim of collecting data and distribute information on harvesting and production in mollusc areas. A web-based geographical information system (GIS application was developed to support the partners to manage data and to make these data available to final users, policy makers and to risk assessors. The GIS for the Strengthening of Centres for Aquaculture Production and Safety surveillance in the Adriatic countries (CAPS2 is divided into two levels, the national and the supranational one, and it distributes spatial and epidemiological information coming from various data acquisition and management sites. The great innovation is the possibility for each country to use online drawing, modifying and change of the geographic areas according to national surveillance needs. Currently it hosts data coming from about 230 production and relay areas with more than 29,478 laboratory tests performed on collected samples since August 2014. Data collected are used by each national competent authority to classify production or relay areas according to the EC regulation mentioned and to conduct risk assessment studies to evaluate the level of consumers’ exposure to contaminants in the consumption of bivalve mollusc products.

  4. A critical analysis of the biological impacts of plasticizers on wildlife

    Science.gov (United States)

    Oehlmann, Jörg; Schulte-Oehlmann, Ulrike; Kloas, Werner; Jagnytsch, Oana; Lutz, Ilka; Kusk, Kresten O.; Wollenberger, Leah; Santos, Eduarda M.; Paull, Gregory C.; Van Look, Katrien J. W.; Tyler, Charles R.

    2009-01-01

    This review provides a critical analysis of the biological effects of the most widely used plasticizers, including dibutyl phthalate, diethylhexyl phthalate, dimethyl phthalate, butyl benzyl phthalate and bisphenol A (BPA), on wildlife, with a focus on annelids (both aquatic and terrestrial), molluscs, crustaceans, insects, fish and amphibians. Moreover, the paper provides novel data on the biological effects of some of these plasticizers in invertebrates, fish and amphibians. Phthalates and BPA have been shown to affect reproduction in all studied animal groups, to impair development in crustaceans and amphibians and to induce genetic aberrations. Molluscs, crustaceans and amphibians appear to be especially sensitive to these compounds, and biological effects are observed at environmentally relevant exposures in the low ng l−1 to µg l−1 range. In contrast, most effects in fish (except for disturbance in spermatogenesis) occur at higher concentrations. Most plasticizers appear to act by interfering with the functioning of various hormone systems, but some phthalates have wider pathways of disruption. Effect concentrations of plasticizers in laboratory experiments coincide with measured environmental concentrations, and thus there is a very real potential for effects of these chemicals on some wildlife populations. The most striking gaps in our current knowledge on the impacts of plasticizers on wildlife are the lack of data for long-term exposures to environmentally relevant concentrations and their ecotoxicity when part of complex mixtures. Furthermore, the hazard of plasticizers has been investigated in annelids, molluscs and arthropods only, and given the sensitivity of some invertebrates, effects assessments are warranted in other invertebrate phyla. PMID:19528055

  5. A faunistic survey of digenean larvae infecting freshwater snails ...

    African Journals Online (AJOL)

    Biomphalaria and Bulinus spp have been reported in Tanzania as vectors of Schistosoma mansoni and Schistosoma haematobium respectively. Thus most schistosomiasis control efforts have focussed on elimination of these molluscs in freshwater systems or deworming infected persons. In addition almost there is limited ...

  6. De weekdieren van de Nederlandse brakwatergebieden (Mollusca)

    NARCIS (Netherlands)

    Kuijper, W.J.

    2000-01-01

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

  7. Prevalance and consequences of the most frequently observed alien molluse in US wadeable stream ecosystems

    Science.gov (United States)

    Alien molluscs are widely distributed in U.S. streams. While some raise economic concerns on the order of billions of dollars, documentation of widespread ecological effects has, in some instances, been more elusive. A probability survey of wadeable streams of the coterminous U.S...

  8. The stratigraphy and regional structure of Miocene deposits in western Amazonia (Peru, Colombia and Brazil), with implications for late Neogene landscape evolution

    NARCIS (Netherlands)

    Wesselingh, F.P.; Hoorn, M.C.; Guerrero, J.; Räsänen, M.E.; Romero Pittmann, L.; Salo, J.A.

    2006-01-01

    A biozonation based on molluscs is proposed for Miocene deposits of western Amazonia (Peru, Colombia and Brazil), commonly referred to as the Pebas Formation. The new zonation refines existing pollen zonations and provides a key for the quick assessment of the stratigraphic position of Neogene

  9. A name is a name is a name: some thoughts and personal opinions about molluscan scientific names

    NARCIS (Netherlands)

    Dance, S.P.

    2009-01-01

    Since 1758, with the publication of Systema Naturae by Linnaeus, thousands of scientific names have been proposed for molluscs. The derivation and uses of many of them are here examined from various viewpoints, beginning with names based on appearance, size, vertical distribution, and location.

  10. The impact of small benthic passive suspension feeders in shallow marine ecosystems: the hydroids as an example

    NARCIS (Netherlands)

    Gili, J.-M.; Alvà, V.; Coma, R.; Orejas, C.; Pagès, F.; Ribes, M.; Zabala, M.; Arntz, W.; Bouillon, J.; Boero, F.; Hughes, R.G.

    1998-01-01

    Benthic suspension feeders are abundant in littoral and shallow sub-littoral ecosystems, where they feed on the plankton and on organic matter suspended in the water column. Recent studies indicate that active suspension feeders with powerful water filtration mechanisms (e.g., bivalve molluscs) may

  11. Primary structure of the oligosaccharide moiety of hemocyanin from the scorpion Androctonus australis

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Debeire, P.; Montreuil, J.; Goyffon, M.; Kuik, J.A. van; Halbeek, H. van

    1986-01-01

    Hemocyanin, the copper-containing glycoprotein that serves as an oxygen carrier in the hemolymph of some arthropods and molluscs, was obtained from the blood of the scorpion Androctonus australis. Sugar analysis of the glycoprotein revealed that its carbohydrate moiety is of the N-glycosylic type.

  12. Nutrient Discharge from aquaculture operations in function of system design and production enviorment

    NARCIS (Netherlands)

    Verdegem, M.C.J.

    2013-01-01

    In aquaculture, nutrient loading is defined as the difference between nutrients supplied with fertilizers and feed and nutrients harvested in the form of finfish, crustaceans, molluscs and seaweeds. On average, the production of finfish and crustaceans results in a net nutrient loading, while for

  13. An early 'handwritten' shell exchange catalogue of the Leiden Museum, with notes on the collectors Rethaan Macaré and Tischbein

    NARCIS (Netherlands)

    Bruggen, van A.C.

    2013-01-01

    A ‘handwritten’ (lithographed) shell exchange catalogue of the National Museum of Natural History, Leiden (The Netherlands), dated 1850 and containing 864 nominal taxa (861 molluscs and 3 brachiopods), is discussed in the context of the history of the museum. This catalogue must have been

  14. Effect factors for marine eutrophication in LCIA based on species sensitivity to hypoxia

    DEFF Research Database (Denmark)

    Cosme, Nuno Miguel Dias; Hauschild, Michael Zwicky

    2016-01-01

    -observed-effect-concentrations (LOEC), were compiled from literature for 91 demersal species of fish, crustaceans, molluscs, echinoderms, annelids, and cnidarians, and converted to temperature-specific benthic (100 m depth) LOEC values. Species distribution and LOEC values were combined using a species sensitivity distribution (SSD...

  15. Survival under stress: molecular mechanisms of metabolic rate ...

    African Journals Online (AJOL)

    Studies in my laboratory are analysing the molecular mechanisms and regulatory events that underlie transitions to and from hypometabolic states In systems including anoxia-tolerant turtles and molluscs, estivating snails and toads, hibernating small mammals, and freeze tolerant frogs and insects. Our newest research ...

  16. Miocene freshwater Mollusca from western Brazilian Amazonia

    NARCIS (Netherlands)

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

    2006-01-01

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

  17. Molluscan Population Of An African Arid Zone Lake | Idowu | Animal ...

    African Journals Online (AJOL)

    The species composition, abundance and distribution of molluscs population together with some physico-chemical variables from five different stations in the littoral region of lake Alau, MaiduguriBorno state, were studied from October 2001 to September 2002. Three patterns of seasonal abundance were found, maximal ...

  18. Preliminary gut content and dentition analysis reveal subtle resource ...

    African Journals Online (AJOL)

    use

    been hypothesized to have contributed to the evolution and adaptive .... nets with stretched mesh sizes (25.4 to 203.2 mm) during both day and night hours .... Embryos, Eggs. Unicuspid (Deeply embended). 3. Hypotrophic. Sucking. A. alluaudi. Molluscs. Subequally – Unequally bicuspid. 3. Hypertrophic. Crushing. A. nubila.

  19. Thirty-ninth annual report of the director, January-December 1985

    International Nuclear Information System (INIS)

    1986-01-01

    The Fishing Research Institute did investigations on canned fish, canned pet food, crustacea, molluscs, salted-, dried-, smoked-, fresh-, and frozen fish, as well as silage, fish meals and fish oils. Gamma radiation as a method of heat treatment for the sterilisation of salt II, was also discussed

  20. On the identities of the molluscan names described in A Short Zoology of Tahiti in the Society Islands by Anthony Curtiss in 1938 (Mollusca: Cephalopoda, Gastropoda).

    Science.gov (United States)

    Low, Martyn E Y; Tan, Siong Kiat

    2014-02-11

    Anthony Curtiss described two species of cephalopod and nine species of gastropod molluscs from Tahiti. Herein, we discuss and determine the identities of these eleven names. Ten of these names are considered to be junior subjective synonyms of well-known taxa, and one an unavailable name.

  1. A new genus and species of Aclididae (Gastropoda) from off Tenerife, Canary Islands

    NARCIS (Netherlands)

    Moolenbeek, R.G.; Warén, A.

    1987-01-01

    Dr. Manuel Carrillo Pèrez (Universidad de la Laguna) has sent some dredge-samples to the first author. This material contained many interesting molluscs, not mentioned by Nordsieck & Talavera (1979). Amongst them was a very peculiar gastropod species, which was difficult to identify. Based on some

  2. Overwinteringsgedrag van de nauwe korfslak Vertigo angustior (Mollusca)

    NARCIS (Netherlands)

    Boesveld, A.

    2005-01-01

    Overwintering habits of the land snail Vertigo angustior (Mollusca) During a mollusc survey in 2004 en 2005 in the province of Zuid-Holland special attention was paid to Vertigo angustior. The species was observed overwintering in large groups, up to hundreds of specimens together, between mosses

  3. Holocene stratigraphy and vegetation history in the Scoresby Sund area, East Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1978-01-01

    The Holocene stratigraphy in Scoresby Sund is based on climatic change as reflected by fluctuations in fjord and valley glaciers, immigration and extinction of marine molluscs, and the vegetation history recorded in pollen diagrams from five lakes. The histories are dated by C-14, and indirectly...

  4. Heavy metals in seafood of Sepetiba Bay, Rio de Janeiro, Brazil

    International Nuclear Information System (INIS)

    Pfeiffer, W.C.; Fiszman, M.; Lima, N.R.W.; Lacerda, L.D. de

    Metals Cu, Cr, Cd, Zn, Mn and Pb, were measured in seafood items from Sepetiba Bay, Rio de Janeiro, The results showed that the highest concentrations are presented by filter-feeding molluscs, probably due to their relationship with the bay's suspended particulate matter. (M.A.C.) [pt

  5. Neuropeptides predicted from the transcriptome analysis of the gray garden slug Deroceras reticulatum

    Science.gov (United States)

    The gray garden slug, Deroceras reticulatum (Gastropoda: Pulmonata), is one of the most common terrestrial molluscs. Studies on D. reticulatum have mainly focused on ecology and biology due to severe damages on a wide range of vegetables and field crops. However, little is known about hormonal signa...

  6. The gastropod menace: slugs on Brassica plants affect caterpillar survival through consumption and interference with parasitoid attraction

    Science.gov (United States)

    Terrestrial molluscs and insect herbivores play a major role as plant consumers in a number of ecosystems, but their direct and indirect interactions have hardly been explored. The omnivorous nature of slugs makes them potential disrupters of predator-prey relationships, as a direct threat to small ...

  7. Type specimens of Pectinidae (Bivalvia) described by Ignaz von Born (1778 - 1780)

    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

  8. 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

  9. Moringa, marinade, bacteria, fungi, catfish, smoke-dried

    African Journals Online (AJOL)

    Osondu

    2013-01-16

    Jan 16, 2013 ... spoilage thus limiting economic loss and possible heath risk to consumers ... Ethiopian Journal of Environmental Studies and Management Vol. 6 No.1 2013. 1Department of Animal Production, University of Ilorin, Ilorin, ..... Molluscs by Major Fishing Areas. ... Microbiological quality of smoke-dried mangrove.

  10. Molluscan radiations and landscape evolution in Miocene Amazonia

    NARCIS (Netherlands)

    Wesselingh, F.P.

    2008-01-01

    This PhD study aims to exploit the rich archive provided by the Miocene mollusc fauna of the Pebas Formation and other inland Miocene Amazonian formations to reconstruct landscape evolution and biotic development in lowland Amazonia during the Neogene. Over 160 samples from more than 70 Pebas

  11. Intake of 90Sr, 137Cs, 144Ce, 106Ru by fresh water organisms with food and water

    International Nuclear Information System (INIS)

    Marciulioniene, D.P.; Dusauskiene-Duz, R.F.; Polikarpov, G.G.

    1978-01-01

    Investigations of the water basins of various areas of Lithuania were carried out in 1973-1975. The investigations were performed to determine the role of food and water in accumulation of 90 Sr, 137 Cs, 144 Ce, 106 --Ru under experimental conditions by fresh water organisms (molluscs, larvae, insects, fishes) as well as 90 Sr in mollusc and fish organisms under natural conditions. It was found that the intake of the above radionuclides in fresh water organisms with radioactive food was less active and in smaller quantities than that with water. The accumulation levels of the radionuclides in fresh water organisms resulted from the radioactive food, depended on the physical and chemical state of the radionuclides and on the concentration of isotopic and nonisotopic carriers in water, food and in the very organism. Dependence of the accumulation coefficient (AC) of different radionuclides in fresh water organisms on the AC value in food as well as on the diet type was not determined

  12. Assessment and rehabilitation of wildlife affected by an oil spill in Puerto Rico

    Energy Technology Data Exchange (ETDEWEB)

    Mignucci-Giannoni, A.A. [University of Puerto Rico, San Juan (Puerto Rico). Caribbean Stranding Network

    1999-10-01

    On 7 January 1994, the barge Morris J. Berman spilled approximately 3.6 million liters of oil off Punta Escambron in San Juan, Puerto Rico. This resulted in the contamination of extensive areas, impacting on natural resources along more than 48 km of Puerto Rico`s north shore. Thousands of dead and alive oiled organisms washed ashore. Dead wildlife were collected opportunistically, and examined for the presence of oil and identified. Live wildlife was cleaned and treated at a temporary triage facility. A total of 5687 organisms of over 152 species were collected, including cnidarians, annelids, crustaceans, molluscs, echinoderms, fishes, birds and sea turtles. Molluscs and echinoderms were noticeably more affected than other species. Four species classified as endangered or threatened were also affected. A significant impact was observed on the live specimens presented for medical treatment, including shore crabs, birds and sea turtles. Only 63% of these were successfully rehabilitated. (author)

  13. Assessment and rehabilitation of wildlife affected by an oil spill in Puerto Rico

    Energy Technology Data Exchange (ETDEWEB)

    Mignucci-Giannoni, A.A. [University of Puerto Rico, San Juan (Puerto Rico). Caribbean Stranding Network

    1999-07-01

    On 7 January 1994, the barge Morris J. Berman spilled approximately 3.6 million liters of oil off Punta Escambron in San Juan, Puerto Rico. This resulted in the contamination of extensive areas, impacting on natural resources along more than 48 km of Puerto Rico's north shore. Thousands of dead and alive oiled organisms washed ashore. Dead wildlife were collected opportunistically, and examined for the presence of oil and identified. Live wildlife was cleaned and treated at a temporary triage facility. A total of 5687 organisms of over 152 species were collected, including cnidarians, annelids, crustaceans, molluscs, echinoderms, fishes, birds and sea turtles. Molluscs and echinoderms were noticeably more affected than other species. Four species classified as endangered or threatened were also affected. A significant impact was observed on the live specimens presented for medical treatment, including shore crabs, birds and sea turtles. Only 63% of these were successfully rehabilitated. (author)

  14. A Prince's tribute...and trial. Monaco's Prince Albert II followed the footsteps of his great great grandfather when he ventured the Arctic Archipelago to trace climate change, this time with IAEA Marine scientists

    International Nuclear Information System (INIS)

    Lodding, L.

    2006-01-01

    Monaco's Prince Albert II followed the footsteps of his great great grandfather when he ventured to the Arctic Archipelago to track climate change, this time with IAEA Marine scientists. He undertook this trip to draw global attention to the environmental damage to the Arctic regions caused by global warming. Although far away from industrialized areas, Svalbard Island is eminently suitable to observe the evolution of climate change and long-range pollutants transported from northern European countries by water currents and from North America by winds. Using nuclear techniques, it is hoped that some of the causes of climate change can be unlocked. The first of these studies was undertaken to evaluate the shell laminations of a very long-lived marine bivalve mollusc, the Ocean Quahog. The mollusc, with a life expectancy well over a century, acts as a recording of temperature variations and water chemistry. The second project aimed at determining levels of contaminates in marine zooplankton in remote arctic environments for comparison with other climatic regions

  15. Toxic trace elements in Chilean seafoods

    International Nuclear Information System (INIS)

    De Gregori, I.; Delgado, D.; Pinochet, H.; Gras, N.; Thieck, M.; Munoz, L.; Bruhn, C.; Navarrete, G.

    1992-01-01

    Chile is a well known producer and exporter of shell fish. These seafoods, like other specimens of marine origin, are susceptible to environmental and other contaminations like trace elements, including toxicants. Therefore adequate analytical quality assurance is mandatory before accepting analytical results. In this context, use of at least 2 independent methods of determination and validation with certified reference materials (CRM) provides acceptable criteria for judging the reliability of the data. This paper describes sample treatments and analytical procedures for Cd, Cu and Hg determinations in mollusc samples. Three independent analytical techniques, namely differential pulse anodic stripping voltammetry, neutron activation analysis and atomic absorption spectrometry, were used. CRM standards of the IAEA, NIST and BCR were analyzed to evaluate quality assurance. Following the quality control phase, the concentrations of cadmium, copper, and mercury in fresh and canned mollusc samples Tagelus dombeii and Semelle solida (Navajuelas and Almejas chilenas respectively) from different locations were determined. (author). 32 refs.; 4 figs.; 7 tabs

  16. Oxygen isotope fractionation and algal symbiosis in benthic foraminifera from the Gulf of Elat, Israel

    International Nuclear Information System (INIS)

    Buchardt, B.; Hansen, H.J.

    1977-01-01

    In order to investigate possible isotopic fractionations due to algal symbiosis the oxygen and carbon isotope compositions of shell carbonate from symbiont-free and symbiont-bearing benthic foraminifera have been compared to that of molluscs living at the same locality. The material was collected over a depth profile in the Gulf of Elat (Aqaba), Israel, covering the interval from 4 to 125 metres. After corrections variations for temperature with depth, characteristic 18 O-depletions were observed in the foraminiferal shell carbonate when compared to the molluscs. These depletions are interpreted as 1) a constant vital effect seen in all the foraminifera studied and 2) an additional, light-dependent vital effect observed in the symbiont-bearing forms only, caused by incorporation of photosynthetic oxygen formed by the symbiotic algae. This additional vital effect emphasizes the difficulties in applying foraminifera to oxygen isotope palaeotemperature analyses. No well-defined differences in carbon isotope compositions are observed between symbiont-bearing and symbiont-free foraminifera. (author)

  17. Triphenyltin alters lipid homeostasis in females of the ramshorn snail Marisa cornuarietis.

    Science.gov (United States)

    Lyssimachou, Angeliki; Navarro, Juan Carlos; Bachmann, Jean; Porte, Cinta

    2009-05-01

    Molluscs are sensitive species to the toxic effects of organotin compounds, particularly to masculinisation. Both tributyltin (TBT) and triphenyltin (TPT) have been recently shown to bind to mollusc retinoid X receptor (RXR). If RXR is involved in lipid homeostasis, exposure to TPT would have an immediate effect on endogenous lipids. To test this hypothesis, the ramshorn snail Marisa cornuarietis was exposed to environmentally relevant concentrations of TPT (30, 125, 500 ng/L as Sn) in a semi-static water regime for 7 days. Percentage of lipids and total fatty acid content decreased significantly in TPT-exposed females while the activity of peroxisomal acyl-CoA oxidase, involved in fatty acid catabolism, increased. In addition, fatty acid profiles (carbon chain length and unsaturation degree) were significantly altered in exposed females but not in males. This work highlights the ability of TPT to disrupt lipid metabolism in M. cornuarietis at environmentally realistic concentrations and the higher susceptibility of females in comparison to males.

  18. Airborne seafood allergens as a cause of occupational allergy and asthma.

    Science.gov (United States)

    Lopata, Andreas L; Jeebhay, Mohamed F

    2013-06-01

    Occupational allergy and asthma is a serious adverse health outcome affecting seafood-processing workers. Allergic reactions are directed to two major seafood groups: fish and shellfish, with the latter group comprising crustaceans and molluscs. Several allergenic proteins have been identified in these different groups, but few have been characterised on a molecular level. Parvalbumin appears to be the major fish allergen, while tropomyosin the major crustacean allergen. Other IgE-binding proteins have also been identified in molluscs and other seafood-associated agents (e.g. Anisakis sp), although their molecular nature has not been characterised. Aerosolised allergens can be identified and quantified using immunological and chemical approaches, detecting levels as low as 10 ng/m(3). This contemporary review discusses interesting and recent findings in the area of occupational seafood allergy including high-risk occupations, environmental risk factors for airborne exposures, major and minor allergens implicated and innovative approaches in diagnosing and managing occupational allergy and asthma associated with seafood processing.

  19. Standard Guide for Irradiation of Finfish and Aquatic Invertebrates Used as Food to Control Pathogens and Spoilage Microorganisms

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This guide outlines procedures and operations for the irradiation of raw, untreated, fresh (chilled), or frozen finfish and aquatic invertebrates, while ensuring that the irradiated product is safe and wholesome. 1.1.1 Aquatic invertebrates include molluscs, crustacea, echinoderms, etc. 1.1.1.1 Molluscs include bivalve shellfish, such as clams, mussels, and oysters; snails; and cephalopods, such as squid and octopus. 1.1.1.2 Crustacea include shellfish such as shrimp, lobster, crabs, prawns and crayfish. 1.1.1.3 Echinoderms include sea urchins and sea cucumbers. 1.2 This guide covers absorbed doses used to reduce the microbial and parasite populations in aquatic invertebrates and finfish. Such doses typically are below 10 kGy (1). 1.3 The use of reduced-oxygen packaging (vacuum or modified atmosphere, and including products packed in oil) with irradiated, raw product is not covered by this guide. The anaerobic environment created by reduced-oxygen packaging provides the potential for outgrowth o...

  20. Oxygen isotope fractionation and algal symbiosis in benthic foraminifera from the Gulf of Elat, Israel

    Energy Technology Data Exchange (ETDEWEB)

    Buchardt, B; Hansen, H J [Copenhagen Univ. (Denmark)

    1977-01-01

    In order to investigate possible isotopic fractionations due to algal symbiosis the oxygen and carbon isotope compositions of shell carbonate from symbiont-free and symbiont-bearing benthic foraminifera have been compared to that of molluscs living at the same locality. The material was collected over a depth profile in the Gulf of Elat (Aqaba), Israel, covering the interval from 4 to 125 metres. After correcting for variations of temperature with depth, characteristic /sup 18/O-depletions were observed in the foraminiferal shell carbonate when compared to the molluscs. These depletions are interpreted as 1) a constant vital effect seen in all the foraminifera studied and 2) an additional, light-dependent vital effect observed in the symbiont-bearing forms only, caused by incorporation of photosynthetic oxygen formed by the symbiotic algae. This additional vital effect emphasizes the difficulties in applying foraminifera to oxygen isotope palaeotemperature analyses. No well-defined differences in carbon isotope compositions are observed between symbiont-bearing and symbiont-free foraminifera.

  1. Zvyšky bratislavských lužných lesov – významné refúgium podunajskej malakofauny Remnants of alluvial woodland in a urbanised area – important refuge for Middle-Danubian land gastropods (Bratislava City, Slovakia

    Directory of Open Access Journals (Sweden)

    Juraj Čačaný

    2012-10-01

    Full Text Available The paper brings a review of a long-term malacological survey of fragmented urban alluvial woodland, an important refuge of Middle-Danubian terrestrial molluscan fauna. In the area of Bratislava agglomeration we surveyed two softwood and 26 hardwood alluvial forests. Altogether, 52 mollusc species have been recorded during the last 20 years (representing 79% of the total terrestrial mollusc fauna living in the Slovak section of the Danube floodplain. The most frequent species (more than 75% sites were Aegopinella nitens, Helix pomatia, Monachoides incarnatus (every three species at 27 sites, i.e. 96%, Cochlodina laminata (26 sites, 93%, Petasina unidentata (25 sites, Urticicola umbrosus (24 sites, Alinda biplicata (23 sites, and Clausilia pumila (21 sites. The main ecological groups were forest species in general (45%, mainly eurytopic and slightly hygrophilous, hygrophilous species in general (26%, hygrophilous and riparian, euryecious species (16%, semi-steppe (8% and open-country species (5%.

  2. Search for the dose-sensitive optically stimulated luminescence response in natural carbonates

    International Nuclear Information System (INIS)

    Jaek, Ivar; Huett, Galina; Rammo, Ilmar; Vasilchenko, Valeri

    2001-01-01

    Carbonates of different origin, such as Iceland spar, calcites, and mollusc shells, used as electron spin resonance and thermoluminescence paleodosimeters, were studied in order to determine their suitability for optically stimulated luminescence dating. The stimulation/excitation spectra of the afterglow of the samples were recorded in the wavelength range of 250-1100 nm. The results of the study show that these spectra present either excitation spectra of Mn 2+ ion fluorescence (samples of calcites and Iceland spar, red emission recorded) or the excitation spectra of primary phosphorescence (samples of carbonates, including molluscs shells; short-wave emission bands recorded). The recorded stimulation spectra revealed no spectral bands sensitive to stimulation by ionizing radiation, which would disappear as a result of heating and could thus be related to deep traps in carbonates, needed dating. The cause of this situation which is unusual in luminescent crystals, including luminescence (paleo)dosimeters, and the ways of overcoming the difficulties in optical dating of natural carbonates are discussed. (author)

  3. European Scientific Notes. Volume 34, Number 6,

    Science.gov (United States)

    1980-06-30

    During the past year the Depart- molluscs, echinoderms, salps , and doli- ment of Documentation and Publications olids. produced three issues of...of keeping the weary travelers awake. the food of these fish was completed It was reminiscent of the record storm as well. that passed over the same

  4. A Genetic Analysis of Crystal Growth

    DEFF Research Database (Denmark)

    Brown, Stanley; Sarikaya, Mehmet; Johnson, E.

    2000-01-01

    The regulation of crystal morphology by proteins is often observed in biology. It is a central feature in the formation of hard tissues such as bones, teeth and mollusc shells. We have developed a genetic system in the bacterium Escherichia coli to study the protein-mediated control of crystal...

  5. Fine structure of the creeping larva of Loxosomella murmanica: additional evidence for a clade of Kamptozoa (Entoprocta) and Mollusca

    DEFF Research Database (Denmark)

    Haszprunar, Gerhard; Wanninger, Andreas Wilhelm Georg

    2008-01-01

    . The prototroch consists of two ciliary rings; a downstream collecting system is not present. Although there is a one-way gut with a lumen throughout, the larva obviously does not feed. A single pair of protonephridia is present. The foot sole shares distinct similarities with basic molluscs, particularly...

  6. Reactive oxygen species in unstimulated hemocytes of the pacific oyster Crassostrea gigas: a mitochondrial involvement.

    Directory of Open Access Journals (Sweden)

    Ludovic Donaghy

    Full Text Available The Pacific oyster Crassostrea gigas is a sessile bivalve mollusc whose homeostasis relies, at least partially, upon cells circulating in hemolymph and referred to as hemocytes. Oyster's hemocytes have been reported to produce reactive oxygen species (ROS, even in absence of stimulation. Although ROS production in bivalve molluscs is mostly studied for its defence involvement, ROS may also be involved in cellular and tissue homeostasis. ROS sources have not yet been described in oyster hemocytes. The objective of the present work was to characterize the ROS sources in unstimulated hemocytes. We studied the effects of chemical inhibitors on the ROS production and the mitochondrial membrane potential (Δψ(m of hemocytes. First, this work confirmed the specificity of JC-10 probe to measure Δψ(m in oyster hemocytes, without being affected by ΔpH, as reported in mammalian cells. Second, results show that ROS production in unstimulated hemocytes does not originate from cytoplasmic NADPH-oxidase, nitric oxide synthase or myeloperoxidase, but from mitochondria. In contrast to mammalian cells, incubation of hemocytes with rotenone (complex I inhibitor had no effect on ROS production. Incubation with antimycin A (complex III inhibitor resulted in a dose-dependent ROS production decrease while an over-production is usually reported in vertebrates. In hemocytes of C. gigas, the production of ROS seems similarly dependent on both Δψ(m and ΔpH. These findings point out differences between mammalian models and bivalve cells, which warrant further investigation about the fine characterization of the electron transfer chain and the respective involvement of mitochondrial complexes in ROS production in hemocytes of bivalve molluscs.

  7. Book review of Littler DM. Littler MM (2000) Caribbean Reef Plants An Identification Guide to the Reef Plants of the Caribbean, Bahamas, Florida and Gulf of Mexico

    Science.gov (United States)

    Zuschin, M.; Hohenegger, J.; Steininger, F.

    2001-09-01

    Information on spatial variability and distribution patterns of organisms in coral reef environments is necessary to evaluate the increasing anthropogenic disturbance of marine environments (Richmond 1993; Wilkinson 1993; Dayton 1994). Therefore different types of subtidal, reef-associated hard substrata (reef flats, reef slopes, coral carpets, coral patches, rock grounds), each with different coral associations, were investigated to determine the distribution pattern of molluscs and their life habits (feeding strategies and substrate relations). The molluscs were strongly dominated by taxa with distinct relations to corals, and five assemblages were differentiated. The Dendropoma maxima assemblage on reef flats is a discrete entity, strongly dominated by this encrusting and suspension-feeding gastropod. All other assemblages are arranged along a substrate gradient of changing coral associations and potential molluscan habitats. The Coralliophila neritoidea- Barbatia foliata assemblage depends on the presence of Porites and shows a dominance of gastropods feeding on corals and of bivalves associated with living corals. The Chamoidea- Cerithium spp. assemblage on rock grounds is strongly dominated by encrusting bivalves. The Drupella cornus-Pteriidae assemblage occurs on Millepora- Acropora reef slopes and is strongly dominated by bivalves associated with living corals. The Barbatia setigera- Ctenoides annulata assemblage includes a broad variety of taxa, molluscan life habits and bottom types, but occurs mainly on faviid carpets and is transitional among the other three assemblages. A predicted degradation of coral coverage to rock bottoms due to increasing eutrophication and physical damage in the study area (Riegl and Piller 2000) will result in a loss of coral-associated molluscs in favor of bivalve crevice dwellers in dead coral heads and of encrusters on dead hard substrata.

  8. Molluscan assemblages on coral reefs and associated hard substrata in the northern Red Sea

    Science.gov (United States)

    Zuschin, M.; Hohenegger, J.; Steininger, F.

    2001-09-01

    Information on spatial variability and distribution patterns of organisms in coral reef environments is necessary to evaluate the increasing anthropogenic disturbance of marine environments (Richmond 1993; Wilkinson 1993; Dayton 1994). Therefore different types of subtidal, reef-associated hard substrata (reef flats, reef slopes, coral carpets, coral patches, rock grounds), each with different coral associations, were investigated to determine the distribution pattern of molluscs and their life habits (feeding strategies and substrate relations). The molluscs were strongly dominated by taxa with distinct relations to corals, and five assemblages were differentiated. The Dendropoma maxima assemblage on reef flats is a discrete entity, strongly dominated by this encrusting and suspension-feeding gastropod. All other assemblages are arranged along a substrate gradient of changing coral associations and potential molluscan habitats. The Coralliophila neritoidea- Barbatia foliata assemblage depends on the presence of Porites and shows a dominance of gastropods feeding on corals and of bivalves associated with living corals. The Chamoidea- Cerithium spp. assemblage on rock grounds is strongly dominated by encrusting bivalves. The Drupella cornus-Pteriidae assemblage occurs on Millepora- Acropora reef slopes and is strongly dominated by bivalves associated with living corals. The Barbatia setigera- Ctenoides annulata assemblage includes a broad variety of taxa, molluscan life habits and bottom types, but occurs mainly on faviid carpets and is transitional among the other three assemblages. A predicted degradation of coral coverage to rock bottoms due to increasing eutrophication and physical damage in the study area (Riegl and Piller 2000) will result in a loss of coral-associated molluscs in favor of bivalve crevice dwellers in dead coral heads and of encrusters on dead hard substrata.

  9. Pairing Quaternary paleoecology and modern ROV exploration to produce novel reconstructions of marine ecosystem responses to millennial-scale climate change

    Science.gov (United States)

    Myhre, S. E.; Pak, D. K.; Borreggine, M. J.; Hill, T. M.; Kennett, J.; Nicholson, C.; Deutsch, C. A.

    2017-12-01

    One of the most interesting problems for 21st Century marine ecology is understanding the potential physical, chemical, and biological scale of future climate-forced oceanographic changes. These fundamental questions can be informed through the examination of micro- and macrofauna from Quaternary sedimentary sequences, combined with modern observations of continental margin ecosystems. Here we examine Remotely Operated Vehicle (ROV) exploratory videos and sedimentary push cores, to identify biological assemblages, including mollusc, echinoderm, ostracod, and foraminifera density, diversity, and community structure from Santa Barbara Basin in the California Borderland. ROV explorations, from 380-500 meters below sea level (mbsl), describe the zonation of benthic fauna and the distribution of chemosynthetic trophic webs, which are consequences of gradations in the oxygen minimum zone and the ventilating sill depth (475 mbsl). Such observations reveal the modern vertical distribution of chemosynthetic bacterial communities and shallower, diverse communities associated with detrital food webs. Biological assemblages from 16.1-3.4 ka (from core MV0811-15JC, collected at 418 mbsl) produce a suite of paleoceanographic indicators, such as dissolved oxygen concentrations (foraminifera), chemosynthetic trophic webs (molluscs), and water masses (ostracods). These assemblages demonstrate how continental margin ecosystems reorganize vertically (through the water column) and geographically through climate events, for example through the loss of cryophilic species, the ephemeral occurrence of chemosynthetic communities, and the trace fossil evidence (through predation scarring on mollusc shells) of higher trophic web interactions. Together with ROV seafloor observations, these communities can reconstruct step-by-step vertical changes in the zonation of the continental margin, and can identify intervals of zonation change in relation to both Santa Barbara Basin ventilation and the

  10. Twelve invertebrate and eight fish species new to the marine fauna of Madeira, and a discussion of the zoogeography of the area

    Science.gov (United States)

    Wirtz, Peter

    1998-06-01

    The benthic ctenophore Vallicula multiformis, a large undescribed flatworm species of the genus Pseudoceros, the prosobranch gastropod Tonna maculosa, the opisthobranch gastropods Placida cf. dendritica, Caloria elegans, Aeolidiella sanguinea, Janolus cristatus, the decapod Balssia gasti, the sea urchin Schizaster canaliferus and the tunicates Clavelina lepadiformis, Clavelina dellavallei and Pycnoclavella taureanensis are recorded from Madeira for the first time. This is the first record of a platyctenid ctenophore in the eastern Atlantic. The teleost fishes Pomatoschistus pictus, Vaneaugobius canariensis, Chromogobius sp., Nerophis ophidion, Hippocampus hippocampus, Acanthocybium solandri, Sphyraena viridensis and Sphyraena barracuda are recorded from Madeira for the first time. The presence of the sea-hare Aplysia dactylomela at Madeira is confirmed; the species has increased tremendously in abundance in the last four years. The crocodile fish Grammoplites gruveli can occasionally be found in the mantle cavity of cuttlefish ( Sepia officinalis) sold at the fish market of Funchal, but does not originate from Madeiran waters. An analysis of 100 new records from the coastal fauna of Madeira shows that, while predominantly of lusitanian, mediterranean and mauritanian affinity, Madeira’s shallow water fauna contains a large component of tropical species.

  11. Monitoring tectonic uplift and paleo-environmental reconstruction for marine terraces near Magaracik and Samandag, Hatay Province, Turkey

    International Nuclear Information System (INIS)

    Florentin, Jonathan A.; Blackwell, Bonnie A.B.; Blickstein, Joel I.B.; Skinner, Anne R.; Tueysuez, Okan; Tari, Ufuk; Can Genc, S.; Imren, Caner; Mo, Shirley; Huang, Yiwen E.W.; Kim, Maria

    2014-01-01

    Near Hatay, the Antakya-Samandag-Cyprus Fault (ASCF), East Anatolian and Dead Sea Fault Zones, the large faults that form the edges of the African, Anatolian, Cyprus and Arabian Plates, all produce large earthquakes, which have decimated Hatay repeatedly. Near Samandag, Hatay, differential vertical displacement on the ASCF has uplifted the southeastern side relative to northwestern side, producing large fault scarps that parallel the Asi (Orontes) River. Tectonic uplift coupled with Quaternary sea level fluctuations has produced several stacked marine terraces stranded above current sea level. This study dated 24 mollusc samples from 10 outcrops on six marine terraces near Samandag electron spin resonance (ESR). Ages were calculated using time-averaged and volumetrically averaged external dose rates, modelled by assuming typical water depths for the individual species and sediment thicknesses estimated from geological criteria. Uplift rates were then calculated for each fault block. At all the Magaracik terraces, the dates suggest that many shells were likely reworked. On the 30 m terrace at Magaracik IV (UTM 766588-3999880), Lithophagus burrows with in situ shells cross the unconformity. One such shell dated to 62 ± 6 ka, setting the minimum possible age for the terrace. For all the Magaracik terraces at ∼30 m above mean sea level (amsl), the youngest ages for the reworked shells, which averaged 60 ± 3 ka for six separate analyses, sets the maximum possible age for this unit. Thus, the terrace must date to 60-62 ± 3 ka, at the MIS 3/4 boundary when temperatures and sea levels were fluctuating rapidly. Older units dating to MIS 7, 6, and 5 likely were being eroded to supply some fossils found in this terrace. At Magaracik Dump (UTM 765391-4001048), ∼103 m amsl, Ostrea and other shells were found cemented in growth position to the limestone boulders outcropping there -1 , since MIS 5c. At Samandag Kurt Stream at 38 m amsl, molluscs were deposited fine sandy

  12. Recognizing cephalopod boreholes in shells and the northward spread of Octopus vulgaris Cuvier, 1797 (Cephalopoda, Octopodoidea)

    NARCIS (Netherlands)

    Hiemstra, Auke-Florian

    2015-01-01

    Octopuses prey on molluscs by boring through their shell. Among the regular naticid borings, traces of cephalopod predation should be found soon on Dutch beaches. Bottom trawling has declined, and by the effects of global warming Octopus will find its way back to the North Sea where it lived before.

  13. Lanthanides, thorium, iodine in terrestrail invertebrates

    International Nuclear Information System (INIS)

    Zhulidov, A.V.; Pokarzhevskij, A.D.; Katargin, N.V.; AN SSSR, Moscow

    1991-01-01

    It is shown that among examined terrestrial invertebrates the highest levels on lanthanide and thorium concentration are typical for animals, feeding on plant tissues - earthworms, molluscs, diploid. It is shown that there are no reasons to hope, that regularities of migration of transuranium elements and lanthanides in tropic chains are identical

  14. Detection of hepatitis A virus in shellfish by nested reverse transcription-PCR

    NARCIS (Netherlands)

    Croci, L.; Medici, de D.; Morace, G.; Fiore, A.; Scalfaro, C.; Beneduce, F.; Toti, L.

    1999-01-01

    A method for the detection of HAV in shellfish, based on the use of guanidinium isothiocyanate-contg. soln. for RNA extn. and purifn. steps, followed by nested PCR, is hereby proposed. Tests were carried out on mollusc samples spiked with HAV strain FG. Results showed that in samples subjected only

  15. Small-sized euryhaline fish as intermediate hosts of the digenetic trematode Cryptocotyle concavum

    Science.gov (United States)

    Zander, C. D.; Kollra, H.-G.; Antholz, B.; Meyer, W.; Westphal, D.

    1984-03-01

    Cercariae of the trematode Cryptocotyle concavum, which encyst in skin and/or kidney of sticklebacks and gobies, were studied in the Schlei Fjord (western Baltic Sea). Mean incidence of dermal cysts was 48 % in Gasterosteus aculeatus and 37 % in Pungitius pungitius. No cysts were found in the kidneys of sticklebacks. While 97 % of Pomatoschistus microps had encysted metacercariae in the kidneys, only 2 % had cysts in the skin. Pomatoschistus minutus, however, showed hardly any cyst infestation of either skin or kidney. In P. microps the intensity of infestation by metacercariae was frequently more than 50 cysts; in contrast, sticklebacks rarely exhibited more than 5 dermal cysts. Infested fish were larger than 10 mm in total length, the incidence rate increasing with growth. Parasitic infestation depends on ambient salinity: C. concavum was not found at salinities below 4 ‰. In contrast to the high incidence in fish, the first hosts — the snails Hydrobia stagnalis and H. neglecta — showed remarkably low infection rates (3 to 5 %). The findings reported are related to the distribution of C. concavum, the mode of life of infested fish, the feeding habits of the final hosts and the infestation of P. microps by other parasites. Evidently, P. microps represents an optimal second host for C. concavum.

  16. Spatial and temporal patterns of benthic invertebrates in the Tagus estuary, Portugal: comparison between subtidal and an intertidal mudflat

    Directory of Open Access Journals (Sweden)

    Susana França

    2009-06-01

    Full Text Available Intertidal mudflats are a dominant feature in many estuarine systems and may be a significant component of the feeding grounds available for many fish and bird species. Therefore, it is crucial to determine the importance and role that this particular habitat plays for the different estuarine communities. Spatial and temporal dynamics of macrobenthic communities in an intertidal mudflat of the Tagus estuary were assessed in order to determine the role of this habitat in the whole estuarine functioning. Benthic macroinvertebrate communities were sampled monthly in two intertidal areas (upper and lower and in the adjoining subtidal area for one year. Macroinvertebrate density and biomass in the intertidal mudflat were higher than in the subtidal area, but no clear trends were found between the lower and upper intertidal area. Spatial patterns in the community were more pronounced than seasonal patterns. This benthic community was characterised by high densities of Pygospio elegans, Scrobicularia plana, Cyathura carinata, Hydrobia ulvae and Nereis diversicolor. Abundance and biomass values in this intertidal mudflat were considered low in comparison with other estuarine habitats, namely seagrass beds. Nevertheless, this habitat plays an important role for the main species present in the community, acting as a key area for recruitment, with high concentrations for many invertebrate species.

  17. A bird's eye survey of Central American planorbid molluscs.

    Science.gov (United States)

    Paraense, W Lobato

    2003-01-01

    In the course of two trips to Central America (June 1967 and JulyAugust 1976) I had the opportunity of collecting topotypic specimens of Planorbis nicaraguanus Morelet, 1849, anatomically defined in this paper, and of P. yzabalensis Crosse & Fischer, 1879, the identity of the latter with Drepanotrema anatinum (Orbigny, 1835) is confirmed. The following planorbid species were also found: Helisoma trivolvis (Say, 1817) in Nicaragua, Guatemala, Costa Rica and Belize; H. duryi (Wetherby, 1879) in Costa Rica; Biomphalaria helophila (Orbigny, 1835) in Guatemala, Belize, Nicaragua, Costa Rica and El Salvador; B. kuhniana (Clessin, 1883) in Panama; B. obstructa (Morelet,1849) in Guatemala, Belize and El Salvador; B. straminea (Dunker, 1848) in Costa Rica; B. subprona (Martens, 1899) in Guatemala; D. anatinum (Orbigny,1835) in Belize, Guatemala, Nicaragua and Costa Rica; D. depressissimum (Moricand,1839) in Nicaragua, Costa Rica and Panama; D. lucidum (Pfeiffer, 1839) in Guatemala, Belize and Nicaragua; D. surinamense (Clessin, 1884) in Costa Rica and Panama; and Gyraulus percarinatus sp. n. in Panama. The occurrence of B. kuhniana and D. surinamense is first recorded in Central America, and Gyraulus percarinatus is the first representative of the genus provenly occurring in the American continent south of the United States. The following synonymy is proposed: Planorbis declivis Tate, 1870 = Biomphalaria helophila (Orbigny, 1835); Planorbis isthmicus Pilsbry, 1920 = Biomphalaria kuhniana (Clessin, 1883); Planorbis cannarum Morelet, 1849 and Segmentina donbilli Tristram, 1861 = Biomphalaria obstructa (Morelet, 1849); and Planorbis yzabalensis Crosse & Fischer, 1879 = Drepanotrema anatinum (Orbigny, 1835), confirming Aguayo (1933).

  18. Toxicity of tributyltin in the marine mollusc Mytilus edulis.

    Science.gov (United States)

    Hagger, Josephine A; Depledge, Michael H; Galloway, Tamara S

    2005-01-01

    Our previous studies have demonstrated that tributyltin (TBT) is genotoxic to the early life stages of marine mussels and worms. Here, the toxicity of TBT to adult organisms was determined using a suite of biomarkers designed to detect cytotoxic, immunotoxic and genotoxic effects. Exposure of adult mussels, Mytilus edulis, to environmentally realistic concentrations of TBTO for 7 days resulted in a statistically significant decrease in cell viability at concentrations of 0.5 microg/l and above. TBT had no effect on phagocytic activity or antioxidant capacity (FRAP assay). There was a statistically significant increase in DNA damage detected using the comet and micronucleus assays between the controls and 0.5, 1 and 5 microg/l of TBTO (P > 0.0005). Furthermore there was a strong correlation between DNA strand breaks (comet assay) and formation of micronuclei (P = 0.0005; R2 = 61.5%). Possible mechanisms by which TBT could damage DNA either directly or indirectly are discussed including the possibility that TBT is genotoxic due to its ability to disrupt calcium homeostasis.

  19. A comparison of mollusc diversity between the relatively pristine ...

    African Journals Online (AJOL)

    2016-04-02

    Wittmann, ...... of suitable biotopes and possible negative impacts from the .... BROWN DS (1994) Freshwater Snails of Africa and their Medical. Importance .... Department of Environmental Affairs and Tourism, Pretoria. TAYLOR ...

  20. Isotopic and elemental proxies in mollusc and brachiopod calcite

    DEFF Research Database (Denmark)

    Ullmann, Clemens Vinzenz

    composition of the oceans have changed. These changes of environmental conditions and seawater composition are primarily caused by plate tectonic processes, the cyclic variations of the Earth’s orbital parameters and living organisms, actively causing, and passively adapting to shifting conditions...

  1. Dr C. Beets (1916-1995) and the 'Rijksmuseum van Geologie en Mineralogie'

    NARCIS (Netherlands)

    Winkler Prins, C.F.

    1996-01-01

    Dr Cornelis Beets, internationally renowned specialist of Indonesian Cainozoic molluscs, died on the 28th of July 1995. Born April 25, 1916, he read geology at Leiden University and obtained his PhD in 1941 on a geological study of the Turin Hills (Italy). When working on his PhD, he had already

  2. Evaluation of the acute toxicity of refined petroleum products against ...

    African Journals Online (AJOL)

    Static and static-renewal evaluation of the acute toxicity of three refined petroleum products — petrol, kerosene and diesel — against two freshwater animals, the mollusc Pila ovata and the fish Poecilia reticulata, was conducted in the laboratory. Petrol, kerosene and diesel were found to be moderately toxic to the test ...

  3. On the function of chitin synthase extracellular domains in biomineralization.

    Science.gov (United States)

    Weiss, Ingrid M; Lüke, Florian; Eichner, Norbert; Guth, Christina; Clausen-Schaumann, Hauke

    2013-08-01

    Molluscs with various shell architectures evolved around 542-525 million years ago, as part of a larger phenomenon related to the diversification of metazoan phyla. Molluscs deposit minerals in a chitin matrix. The mollusc chitin is synthesized by transmembrane enzymes that contain several unique extracellular domains. Here we investigate the assembly mechanism of the chitin synthase Ar-CS1 via its extracellular domain ArCS1_E22. The corresponding transmembrane protein ArCS1_E22TM accumulates in membrane fractions of the expression host Dictyostelium discoideum. Soluble recombinant ArCS1_E22 proteins can be purified as monomers only at basic pH. According to confocal fluorescence microscopy experiments, immunolabeled ArCS1_E22 proteins adsorb preferably to aragonitic nacre platelets at pH 7.75. At pH 8.2 or pH 9.0 the fluorescence signal is less intense, indicating that protein-mineral interaction is reduced with increasing pH. Furthermore, ArCS1_E22 forms regular nanostructures on cationic substrates as revealed by atomic force microscopy (AFM) experiments on modified mica cleavage planes. These experiments suggest that the extracellular domain ArCS1_E22 is involved in regulating the multiple enzyme activities of Ar-CS1 such as chitin synthesis and myosin movements by interaction with mineral surfaces and eventually by protein assembly. The protein complexes could locally probe the status of mineralization according to pH unless ions and pCO2 are balanced with suitable buffer substances. Taking into account that the intact enzyme could act as a force sensor, the results presented here provide further evidence that shell formation is coordinated physiologically with precise adjustment of cellular activities to the structure, topography and stiffness at the mineralizing interface. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Giant Clams and Rising CO2: Light May Ameliorate Effects of Ocean Acidification on a Solar-Powered Animal.

    Directory of Open Access Journals (Sweden)

    Sue-Ann Watson

    Full Text Available Global climate change and ocean acidification pose a serious threat to marine life. Marine invertebrates are particularly susceptible to ocean acidification, especially highly calcareous taxa such as molluscs, echinoderms and corals. The largest of all bivalve molluscs, giant clams, are already threatened by a variety of local pressures, including overharvesting, and are in decline worldwide. Several giant clam species are listed as 'Vulnerable' on the IUCN Red List of Threatened Species and now climate change and ocean acidification pose an additional threat to their conservation. Unlike most other molluscs, giant clams are 'solar-powered' animals containing photosynthetic algal symbionts suggesting that light could influence the effects of ocean acidification on these vulnerable animals. In this study, juvenile fluted giant clams Tridacna squamosa were exposed to three levels of carbon dioxide (CO2 (control ~400, mid ~650 and high ~950 μatm and light (photosynthetically active radiation 35, 65 and 304 μmol photons m-2 s-1. Elevated CO2 projected for the end of this century (~650 and ~950 μatm reduced giant clam survival and growth at mid-light levels. However, effects of CO2 on survival were absent at high-light, with 100% survival across all CO2 levels. Effects of CO2 on growth of surviving clams were lessened, but not removed, at high-light levels. Shell growth and total animal mass gain were still reduced at high-CO2. This study demonstrates the potential for light to alleviate effects of ocean acidification on survival and growth in a threatened calcareous marine invertebrate. Managing water quality (e.g. turbidity and sedimentation in coastal areas to maintain water clarity may help ameliorate some negative effects of ocean acidification on giant clams and potentially other solar-powered calcifiers, such as hard corals.

  5. Transmission dynamics of Fasciola hepatica in the Plateau Region of Mexico. Effect of weather and treatment of mammals under current farm management.

    Science.gov (United States)

    Cruz-Mendoza, Irene; Quiroz-Romero, Héctor; Correa, Dolores; Gómez-Espinoza, Guillermo

    2011-01-10

    The aim of the present work was to study the dynamics of Fasciola hepatica natural infection in ovines, caprines, bovines and two mollusc species, Lymnaea (Fossaria) humilis and Lymnaea (F.) bulimoides, from 2004 to mid 2007 under normal farm management conditions, and the relation to climate changes. The study was performed in a research centre in the plateau of Mexico. Temperature and rainfall were registered every month, as well as the number and intensity of infection in livestock and molluscs, as determined by coprology and direct observation/cercariae release, respectively. The first two years mammals were treated with clorsulon/ivermectin because the animals were harbouring concomitant intestinal nematode infections and this was the available drug combination. During the second period treatment was with triclabendazole. The temperature ranged from around cero to 30 °C, except during September 2005 to January 2006, when a cold climate prevailed. The rainfall augmented every year in July-August, and slightly in April, 2006. Lymneid snails appeared during or immediately after the rainfall peaks of 2004 and 2006, while few L. humilis and no L. bulimoides were present during the same period of 2005, probably because it was cold. A total of 15564 cercariae were released from molluscs during the wet time of 2004, 76 during 2005 and 368 in 2006. Several peaks of infection in mammals were observed, most occurring up to 4 months after the snails had disappeared. As expected, the weather had strong impact on snails and then on livestock infection. Also, treatment given to livestock was related to reduced cercarieae release five months later. Therefore, the combination of treatment and inspection of snails in the biotopes where the livestock graze may facilitate control of fasciolosis under current farm management. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Giant Clams and Rising CO2: Light May Ameliorate Effects of Ocean Acidification on a Solar-Powered Animal.

    Science.gov (United States)

    Watson, Sue-Ann

    2015-01-01

    Global climate change and ocean acidification pose a serious threat to marine life. Marine invertebrates are particularly susceptible to ocean acidification, especially highly calcareous taxa such as molluscs, echinoderms and corals. The largest of all bivalve molluscs, giant clams, are already threatened by a variety of local pressures, including overharvesting, and are in decline worldwide. Several giant clam species are listed as 'Vulnerable' on the IUCN Red List of Threatened Species and now climate change and ocean acidification pose an additional threat to their conservation. Unlike most other molluscs, giant clams are 'solar-powered' animals containing photosynthetic algal symbionts suggesting that light could influence the effects of ocean acidification on these vulnerable animals. In this study, juvenile fluted giant clams Tridacna squamosa were exposed to three levels of carbon dioxide (CO2) (control ~400, mid ~650 and high ~950 μatm) and light (photosynthetically active radiation 35, 65 and 304 μmol photons m-2 s-1). Elevated CO2 projected for the end of this century (~650 and ~950 μatm) reduced giant clam survival and growth at mid-light levels. However, effects of CO2 on survival were absent at high-light, with 100% survival across all CO2 levels. Effects of CO2 on growth of surviving clams were lessened, but not removed, at high-light levels. Shell growth and total animal mass gain were still reduced at high-CO2. This study demonstrates the potential for light to alleviate effects of ocean acidification on survival and growth in a threatened calcareous marine invertebrate. Managing water quality (e.g. turbidity and sedimentation) in coastal areas to maintain water clarity may help ameliorate some negative effects of ocean acidification on giant clams and potentially other solar-powered calcifiers, such as hard corals.

  7. Control of climate and Tethyan legacy on distribution of Paleocene ...

    Indian Academy of Sciences (India)

    11

    planktotrophic larvae of these benthic molluscs could not cross the deep ocean barrier that lay between the .... temporal data and consideration of the whole epoch in a single time frame, it was still able to ..... Shallow benthic gastropod faunas, hence, flourished in a big ... They also thought that the current was from east to.

  8. Fulltext PDF

    Indian Academy of Sciences (India)

    Unknown

    After a doctorate in Paleontology (1967) at Columbia University, S J Gould went to Harvard where he spent the rest of his career, becoming the Alexander Agassiz Professor of Zoology in 1982. As a paleontologist, he was a specialist of gastropod molluscs from West Indies. But he soon became involved in broader and ...

  9. 1851-IJBCS-Article-Cyril Roméo

    African Journals Online (AJOL)

    hp

    attack rates during the different harvests. This was done in version 12.4 of SPSS software. RESULTS ... rolling up and shrivelled plants. They also cause indirect damages on the young plants by infecting them with .... fruits) by the other bio attackers (birds, molluscs and burns). Contrary to the hot red pepper (Figure 6), the ...

  10. Feeding ecology of the beach silverside Atherinella blackburni (Atherinopsidae in a tropical sandy beach, Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Júlio Guazzelli Gonzalez

    Full Text Available Abstract The feeding ecology of the beach silverside (Atherinella blackburni in the surf zone of a tropical sand beach, located in the southeastern Brazil, was accessed through the gut content analysis of 198 fish. Factors such as fish's size, season and day period were analysed to understand how these variables affect the diet composition of the species. Results show that A. blackburni is a coastal neritic fish with a broad feeding niche. Most recurrent prey were zooplanktonic crustaceans, insects and benthic molluscs, in which Copepoda crustaceans were the dominant dietary item in occurrence and abundance. A. blackburni appears to have a slight ontogenetic shift in its diet, changing from benthic molluscs to crustaceans and insects along its life cycle. The diel activity also reveals to be an important factor to the A. blackburni feeding ecology. The predominant occurrence of small fish during the morning, along with the main preys for this size class, suggests that small individuals use shallower waters as feeding grounds during the morning and, during the night, they move to deeper waters for protection against predators.

  11. Real-time monitoring of calcium carbonate and cationic peptide deposition on carboxylate-SAM using a microfluidic SAW biosensor

    Directory of Open Access Journals (Sweden)

    Anna Pohl

    2014-10-01

    Full Text Available A microfluidic biosensor with surface acoustic wave technology was used in this study to monitor the interaction of calcium carbonate with standard carboxylate self-assembled monolayer sensor chips. Different fluids, with and without biomolecular components, were investigated. The pH-dependent surface interactions of two bio-inspired cationic peptides, AS8 and ES9, which are similar to an extracellular domain of the chitin synthase involved in mollusc shell formation, were also investigated in a biological buffer system. A range of experimental conditions are described that are suitable to study non-covalent molecular interactions in the presence of ionic substances, such as, mineral precursors below the solubility equilibrium. The peptide ES9, equal to the mollusc chitin synthase epitope, is less sensitive to changes in pH than its counterpart AS8 with a penta-lysine core, which lacks the flanking acidic residues. This study demonstrates the extraordinary potential of microfluidic surface acoustic wave biosensors to significantly expand our experimental capabilities for studying the principles underlying biomineralization in vitro.

  12. Arsenic Speciation in Fish Products and Seafood as a Prerequisite for Proper Risk Assessment

    Science.gov (United States)

    Orletti, Roberta; Chessa, Giannina; Carloni, Cristiano; Griffoni, Francesco; Palombo, Paolo; Velieri, Francesco

    2015-01-01

    The Boi Cerbus lagoon, facing a mining and industrial site in Sardinia (Italy), is an important fishing area for the local population. Previous studies showed high concentrations of total arsenic (Astot) in fish, molluscs and crustaceans sampled in the lagoon, and a possible exceeding of the provisional tolerable weekly intake set by the Joint FAO/WHO Expert Committee on Food Additives by some local consumer groups. However, the percentage of inorganic As (Asinorg) should be known for a correct assessment of potential risk, as its toxicity is much higher than that of the organic forms. Eighty samples of 14 different species of fish, molluscs and crustaceans, sampled in the Boi Cerbus lagoon in 3 different seasons (winter, spring and summer), were analysed for Astot by inductively coupled plasma mass spectrometry (ICP-MS) and Asinorg by high performance liquid chromatography-ICP-MS. All the data obtained from the analysis were statistically processed to evaluate significant differences based on season, taxon and habitat, in preparation for a subsequent risk assessment. PMID:27800381

  13. Triphenyltin alters lipid homeostasis in females of the ramshorn snail Marisa cornuarietis

    Energy Technology Data Exchange (ETDEWEB)

    Lyssimachou, Angeliki [Environmental Chemistry Department, IIQAB-CSIC, Jordi Girona 18, 08034 Barcelona (Spain); Navarro, Juan Carlos [Institute of Aquaculture of Torre de la Sal, CSIC, 12595 Ribera de Cabanes, Castellon (Spain); Bachmann, Jean [Department of Ecology and Evolution-Ecotoxicology, Johann Wolfgang Goethe-University Frankfurt, D-60054 Frankfurt am Main (Germany); Porte, Cinta, E-mail: cinta.porte@cid.csic.e [Environmental Chemistry Department, IIQAB-CSIC, Jordi Girona 18, 08034 Barcelona (Spain)

    2009-05-15

    Molluscs are sensitive species to the toxic effects of organotin compounds, particularly to masculinisation. Both tributyltin (TBT) and triphenyltin (TPT) have been recently shown to bind to mollusc retinoid X receptor (RXR). If RXR is involved in lipid homeostasis, exposure to TPT would have an immediate effect on endogenous lipids. To test this hypothesis, the ramshorn snail Marisa cornuarietis was exposed to environmentally relevant concentrations of TPT (30, 125, 500 ng/L as Sn) in a semi-static water regime for 7 days. Percentage of lipids and total fatty acid content decreased significantly in TPT-exposed females while the activity of peroxisomal acyl-CoA oxidase, involved in fatty acid catabolism, increased. In addition, fatty acid profiles (carbon chain length and unsaturation degree) were significantly altered in exposed females but not in males. This work highlights the ability of TPT to disrupt lipid metabolism in M. cornuarietis at environmentally realistic concentrations and the higher susceptibility of females in comparison to males. - Short-term exposure to the fungicide TPT disrupts lipid metabolism in M. cornuarietis at environmentally realistic concentrations.

  14. Polarimetry of Pinctada fucata nacre indicates myostracal layer interrupts nacre structure.

    Science.gov (United States)

    Metzler, Rebecca A; Jones, Joshua A; D'Addario, Anthony J; Galvez, Enrique J

    2017-02-01

    The inner layer of many bivalve and gastropod molluscs consists of iridescent nacre, a material that is structured like a brick wall with bricks consisting of crystalline aragonite and mortar of organic molecules. Myostracal layers formed during shell growth at the point of muscle attachment to the shell can be found interspersed within the nacre structure. Little has been done to examine the effect the myostracal layer has on subsequent nacre structure. Here we present data on the structure of the myostracal and nacre layers from a bivalve mollusc, Pinctada fucata . Scanning electron microscope imaging shows the myostracal layer consists of regular crystalline blocks. The nacre before the layer consists of tablets approximately 400 nm thick, while after the myostracal layer the tablets are approximately 500 nm thick. A new technique, imaging polarimetry, indicates that the aragonite crystals within the nacre following the myostracal layer have greater orientation uniformity than before the myostracal layer. The results presented here suggest a possible interaction between the myostracal layer and subsequent shell growth.

  15. Alimentação de Bairdiella ronchus (Cuvier (Perciformes, Sciaenidae na Baía de Guaratuba, Paraná, Brasil Feeding of Bairdiella ronchus (Cuvier (Perciformes, Sciaenidae at the Guaratuba Bay, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Vendel

    1998-01-01

    Full Text Available Seasonal variation of food items of Bairdiella ronchus (Cuvier, 1830 classified by size was analysed based on monthly samples between september/1993 and september/1996 at the Guaratuba Bay, Southern Brazil. The stomach contents of a hundred eighty-two fishes were analysed by the Occunence Frequency Method and Point Count for a Lot Method. The individuais were divided in two groups, smaller and longer than 140mm, and a comparative study of digestive tract and branchial are was performed for these groups. For fishes smaller than 140mm the following sequence of items was obtained matching both methods by using the Preponderance índices: decapods (subdivided in Brachyura, Caridea and Penaeidea, polychaets, isopods, fishes, unidentified material, copepods, amphipods, molluscs and plant material. For fishes longer than or equal to 140mm the sequence was decapods, polychaets, fishes, copepods, amphipods, isopods, molluscs and plant material, in this order. These results suggest that Bairdiella ronchus at the Guaratuba Bay is a carnivorous species using mainly decapod crustaceans as food throughout the year.

  16. Régime alimentaire de Ctenopoma petherici (Perciformes, Anabantidae dans la rivière Agnéby et dans le lac de barrage hydroélectrique d'Ayamé 2 (Côte d'Ivoire

    Directory of Open Access Journals (Sweden)

    Kassi, GB.

    2018-01-01

    Full Text Available Feeding Diets of Ctenopoma petherici (Perciformes, Anabantidae from the Agneby River and from the Hydroelectric Lake Dam of Ayame 2 (Côte d'Ivoire. The present study describes the feeding habits of Ctenopoma petherici (Perciformes, Anabantidae in the Agneby River and in the hydroelectric Lake dam of Ayame 2. Fishes were caught monthly using gill-nets from September 2015 to August 2016. Stomach contents of 425 specimens were analysed under a magnifying glass and a microscope. The Relative Importance of Food Index has been calculated to assess the relative abundance of the preys. The general profile of the diet indicated that C. petherici feeds on insects, arachnids, molluscs, batrachians, macrophytes and algae. The insects provide the main part of the feeding and they constitute the principal prey category. Macrophytes were the secondary item while arachnids, molluscs, batrachians and algae were accessory preys. These results indicate that this species is omnivorous with an insectivorous tendency. This feeding pattern is seasonally affected, particularly in the Agneby River. However, there is no variation in the diet according to the size of the individuals.

  17. Studies on the distribution of 210Po and 210Pb in the ecosystem of Point Calimere Coast (Palk Strait), India

    International Nuclear Information System (INIS)

    Suriyanarayanan, S.; Brahmanandhan, G.M.; Malathi, J.; Ravi Kumar, S.; Masilamani, V.; Shahul Hameed, P.; Selvasekarapandian, S.

    2008-01-01

    A systematic study on the natural radionuclides such as 210 Po and 210 Pb in the environmental matrices of Point Calimere ecosystem has been undertaken to establish a baseline data on the radiation profile of Point Calimere environment. The environmental samples such as water, sediment and biota (seaweeds, crustaceans, molluscs and fish) have been subjected to analyses. It has been observed that the concentration of 210 Po and 210 Pb in the water samples of Point Calimere to be 0.5 mBq/l and 1.3 mBq/l, respectively. The soft tissues of the organisms accumulated higher 210 Po content while shells and bones contained more 210 Pb. The bivalve molluscs Meretrix casta have been identified to accumulate higher concentration of 210 Po suggesting that they could serve as bio-indicator of radionuclides like 210 Po in the Point Calimere ecosystem. The concentration factor of 210 Po for the biotic components ranged from ∼10 3 to 10 6 while for 210 Pb it ranged from ∼10 3 to 10 5

  18. Arsenic speciation in fish products and seafood as a prerequisite for proper risk assessment

    Directory of Open Access Journals (Sweden)

    Pierluigi Piras

    2015-02-01

    Full Text Available The Boi Cerbus lagoon, facing a mining and industrial site in Sardinia (Italy, is an important fishing area for the local population. Previous studies showed high concentrations of total arsenic (Astot in fish, molluscs and crustaceans sampled in the lagoon, and a possible exceeding of the provisional tolerable weekly intake set by the Joint FAO/WHO Expert Committee on Food Additives by some local consumer groups. However, the percentage of inorganic As (Asinorg should be known for a correct assessment of potential risk, as its toxicity is much higher than that of the organic forms. Eighty samples of 14 different species of fish, molluscs and crustaceans, sampled in the Boi Cerbus lagoon in 3 different seasons (winter, spring and summer, were analysed for Astot by inductively coupled plasma mass spectrometry (ICP-MS and Asinorg by high performance liquid chromatography-ICP-MS. All the data obtained from the analysis were statistically processed to evaluate significant differences based on season, taxon and habitat, in preparation for a subsequent risk assessment.

  19. Triphenyltin alters lipid homeostasis in females of the ramshorn snail Marisa cornuarietis

    International Nuclear Information System (INIS)

    Lyssimachou, Angeliki; Navarro, Juan Carlos; Bachmann, Jean; Porte, Cinta

    2009-01-01

    Molluscs are sensitive species to the toxic effects of organotin compounds, particularly to masculinisation. Both tributyltin (TBT) and triphenyltin (TPT) have been recently shown to bind to mollusc retinoid X receptor (RXR). If RXR is involved in lipid homeostasis, exposure to TPT would have an immediate effect on endogenous lipids. To test this hypothesis, the ramshorn snail Marisa cornuarietis was exposed to environmentally relevant concentrations of TPT (30, 125, 500 ng/L as Sn) in a semi-static water regime for 7 days. Percentage of lipids and total fatty acid content decreased significantly in TPT-exposed females while the activity of peroxisomal acyl-CoA oxidase, involved in fatty acid catabolism, increased. In addition, fatty acid profiles (carbon chain length and unsaturation degree) were significantly altered in exposed females but not in males. This work highlights the ability of TPT to disrupt lipid metabolism in M. cornuarietis at environmentally realistic concentrations and the higher susceptibility of females in comparison to males. - Short-term exposure to the fungicide TPT disrupts lipid metabolism in M. cornuarietis at environmentally realistic concentrations.

  20. A First Insight into the Genome of the Filter-Feeder Mussel Mytilus galloprovincialis.

    Directory of Open Access Journals (Sweden)

    Maria Murgarella

    Full Text Available Mussels belong to the phylum Mollusca, one of the largest and most diverse taxa in the animal kingdom. Despite their importance in aquaculture and in biology in general, genomic resources from mussels are still scarce. To broaden and increase the genomic knowledge in this family, we carried out a whole-genome sequencing study of the cosmopolitan Mediterranean mussel (Mytilus galloprovincialis. We sequenced its genome (32X depth of coverage on the Illumina platform using three pair-end libraries with different insert sizes. The large number of contigs obtained pointed out a highly complex genome of 1.6 Gb where repeated elements seem to be widespread (~30% of the genome, a feature that is also shared with other marine molluscs. Notwithstanding the limitations of our genome sequencing, we were able to reconstruct two mitochondrial genomes and predict 10,891 putative genes. A comparative analysis with other molluscs revealed a gene enrichment of gene ontology categories related to multixenobiotic resistance, glutamate biosynthetic process, and the maintenance of ciliary structures.

  1. A Dopa Decarboxylase Modulating the Immune Response of Scallop Chlamys farreri

    Science.gov (United States)

    Zhou, Zhi; Yang, Jialong; Wang, Lingling; Zhang, Huan; Gao, Yang; Shi, Xiaowei; Wang, Mengqiang; Kong, Pengfei; Qiu, Limei; Song, Linsheng

    2011-01-01

    Background Dopa decarboxylase (DDC) is a pyridoxal 5-phosphate (PLP)-dependent enzyme that catalyzes the decarboxylation of L-Dopa to dopamine, and involved in complex neuroendocrine-immune regulatory network. The function for DDC in the immunomodulation remains unclear in invertebrate. Methodology The full-length cDNA encoding DDC (designated CfDDC) was cloned from mollusc scallop Chlamys farreri. It contained an open reading frame encoding a polypeptide of 560 amino acids. The CfDDC mRNA transcripts could be detected in all the tested tissues, including the immune tissues haemocytes and hepatopancreas. After scallops were treated with LPS stimulation, the mRNA expression level of CfDDC in haemocytes increased significantly (5.5-fold, PDDC inhibitor methyldopa, the ROS level in haemocytes of scallops was decreased significantly to 0.41-fold (PDDC in scallop, modulated the immune responses such as haemocytes encapsulation as well as the ROS level through its catalytic activity, functioning as an indispensable immunomodulating enzyme in the neuroendocrine-immune regulatory network of mollusc. PMID:21533240

  2. Molecular analyses reveal high species diversity of trematodes in a sub-Arctic lake

    Science.gov (United States)

    Soldánová, Miroslava; Georgieva, Simona; Roháčováa, Jana; Knudsen, Rune; Kuhn, Jesper A.; Henriksen, Eirik H.; Siwertsson, Anna; Shaw, Jenny C.; Kuris, Armand M.; Amundsen, Per-Arne; Scholz, Tomáš; Lafferty, Kevin D.; Kostadinova, Aneta

    2017-01-01

    To identify trematode diversity and life-cycles in the sub-Arctic Lake Takvatn, Norway, we characterised 120 trematode isolates from mollusc first intermediate hosts, metacercariae from second intermediate host fishes and invertebrates, and adults from fish and invertebrate definitive hosts, using molecular techniques. Phylogenies based on nuclear and/or mtDNA revealed high species richness (24 species or species-level genetic lineages), and uncovered trematode diversity (16 putative new species) from five families typical in lake ecosystems (Allocreadiidae, Diplostomidae, Plagiorchiidae, Schistosomatidae and Strigeidae). Sampling potential invertebrate hosts allowed matching of sequence data for different stages, thus achieving molecular elucidation of trematode life-cycles and exploration of host-parasite interactions. Phylogenetic analyses also helped identify three major mollusc intermediate hosts (Radix balthica, Pisidium casertanum and Sphaerium sp.) in the lake. Our findings increase the known trematode diversity at the sub-Arctic Lake Takvatn, showing that digenean diversity is high in this otherwise depauperate sub-Arctic freshwater ecosystem, and indicating that sub-Arctic and Arctic ecosystems may be characterised by unique trematode assemblages.

  3. Real-time monitoring of calcium carbonate and cationic peptide deposition on carboxylate-SAM using a microfluidic SAW biosensor.

    Science.gov (United States)

    Pohl, Anna; Weiss, Ingrid M

    2014-01-01

    A microfluidic biosensor with surface acoustic wave technology was used in this study to monitor the interaction of calcium carbonate with standard carboxylate self-assembled monolayer sensor chips. Different fluids, with and without biomolecular components, were investigated. The pH-dependent surface interactions of two bio-inspired cationic peptides, AS8 and ES9, which are similar to an extracellular domain of the chitin synthase involved in mollusc shell formation, were also investigated in a biological buffer system. A range of experimental conditions are described that are suitable to study non-covalent molecular interactions in the presence of ionic substances, such as, mineral precursors below the solubility equilibrium. The peptide ES9, equal to the mollusc chitin synthase epitope, is less sensitive to changes in pH than its counterpart AS8 with a penta-lysine core, which lacks the flanking acidic residues. This study demonstrates the extraordinary potential of microfluidic surface acoustic wave biosensors to significantly expand our experimental capabilities for studying the principles underlying biomineralization in vitro.

  4. The effect of em>Hydrobia ulvaeem> and microphytobenthos on cohesive sediment dynamics on an intertidal mudflat described by means of numerical modelling

    DEFF Research Database (Denmark)

    Lumborg, Ulrik; Andersen, Thorbjørn Joest; Pejrup, Morten

    2006-01-01

    been used as input to the 2D hydrodynamic numerical model MIKE 21 MT. The model was used to investigate the effect that differences in the benthic communities may have on the net deposition. The model included computation of hydrodynamics, wave fields and cohesive sediment dynamics. Based...

  5. Alien species in the Mediterranean Sea by 2010. A contribution to the application of European Union’s Marine Strategy Framework Directive (MSFD. Part I. Spatial distribution

    Directory of Open Access Journals (Sweden)

    A. ZENETOS

    2010-11-01

    Species that are classified as invasive or potentially invasive are 134 in the whole of the Mediterranean: 108 are present in the EMED, 76 in the CMED, 53 in the Adriatic and 64 in the WMED. The WMED hosts most invasive macrophytes, whereas the EMED has the lion’s share in polychaetes, crustaceans, molluscs and fish.

  6. The Ichnogenus Gastrochaenolites and its Tracemakers from Firmgrounds of the Bohemian Cretaceous Basin (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Mikuláš, Radek; Žítt, Jiří; Nekovařík, Č.

    2003-01-01

    Roč. 10, - (2003), s. 13-21 ISSN 1042-0940 R&D Projects: GA ČR GA205/99/1315 Institutional research plan: CEZ:AV0Z3013912 Keywords : Mollusc traces * Gastrochaenolites * Cretaceous Subject RIV: DB - Geology ; Mineralogy http://rzblx1.uni-regensburg.de/ezeit/detail.phtml?bibid=CASCR& colors =7&lang=en&jour_id=41560

  7. Errata to the Review Article (Medit. Mar. Sci. 11/2, 2010, 381-493: "Alien species in the Mediterranean Sea by 2010. A contribution to the application of European Union’s Marine Strategy Framework Directive (MSFD. Part I. Spatial distribution"

    Directory of Open Access Journals (Sweden)

    A. ZENETOS

    2011-12-01

    Species that are classified as invasive or potentially invasive are 134 in the whole of the Mediterranean: 108 are present in the EMED, 76 in the CMED, 53 in the Adriatic and 64 in the WMED. The WMED hosts most invasive macrophytes, whereas the EMED has the lion’s share in polychaetes, crustaceans, molluscs and fish.

  8. Biomonitoring: Guide for the Use of Biological Endpoints in Monitoring Species, Habitats, and Projects

    Science.gov (United States)

    2007-11-01

    et al ., 1991; Welsh and Ollivier 1998), behavior (Daly et al ., 1995; Maltby et al ., 2002 ...include changes in species diversity and community structure (Karr 1981; Bramblett and Fausch 1991; Barbour et al ., 1999; Zweig and Rabeni 2001; Martin et ...programs in aquatic habitats; these programs typically employ benthic invertebrates such as molluscs (Maltby et al ., 2002 ; Applied Biomonitoring

  9. Reproductive characterization of three species of Giant African land ...

    African Journals Online (AJOL)

    Administrator

    2011-09-05

    Sep 5, 2011 ... wild lay eggs about two to three times per season. (Cobbinah et al., 2008). ... courtship and copulatory duration of three (3) species of. Giant African land ... digital stop watch and the snails were observed from 6.00 pm to. 7.00 am daily ..... trail following in apple snail, Pomacea canaliculata. J. Mollusc stud.

  10. Study of dinosaur's egg shell by EPR method; Issledovaniya metodom EhPR skorlupy yaits dinozavrov

    Energy Technology Data Exchange (ETDEWEB)

    Tleuberdina, R A; Nasirov, R N

    1998-07-01

    Two varieties of calcium carbonate are defined on base of ESR spectra radiation-inducted signals containing in mollusc shell and dinosaur and ostrich egg shell; their spectral characters are studied by infrared-spectroscopy methods and X-ray analysis. Possibility of correlation between ESR signals intensity of CO{sub 2}-radical of investigated object and geological age is determined. (author)

  11. Study of dinosaur's egg shell by EPR method

    International Nuclear Information System (INIS)

    Tleuberdina, R.A.; Nasirov, R.N.

    1998-01-01

    Two varieties of calcium carbonate are defined on base of ESR spectra radiation-inducted signals containing in mollusc shell and dinosaur and ostrich egg shell; their spectral characters are studied by infrared-spectroscopy methods and X-ray analysis. Possibility of correlation between ESR signals intensity of CO 2 -radical of investigated object and geological age is determined. (author)

  12. Learning and memory in Octopus vulgaris: a case of biological plasticity.

    Science.gov (United States)

    Zarrella, Ilaria; Ponte, Giovanna; Baldascino, Elena; Fiorito, Graziano

    2015-12-01

    Here we concisely summarize major aspects of the learning capabilities of the cephalopod mollusc Octopus vulgaris, a solitary living marine invertebrate. We aim to provide a backdrop against which neurobiology of these animals can be further interpreted and thus soliciting further interest for one of the most advanced members of invertebrate animals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Reproductive biology and diet of Mustelus punctulatus (Risso, 1826 (Chondrichthyes: Triakidae from the Gulf of Gabès, central Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Bechir Saïdi

    2009-06-01

    Full Text Available Specimens of Mustelus punctulatus were collected between January 2002 and December 2005 from commercial fisheries in the Gulf of Gabès (central Mediterranean Sea. Males and females reached a maximum total length (TL of 111 and 122 cm respectively. Males matured between 76 and 88.5 cm TL, with a size at maturity (TL50 of 81.4 cm TL. Females matured between 88 and 100 cm TL with a TL50 of 95.6 cm. Females had an annual reproductive cycle. Mating occurred through late-May and June. Ovulation occurred from early July to mid-August with parturition occurring from mid-May to early June, after a gestation period of 11 months. The size at birth was estimated to be 24.5 to 30.5 cm TL. Positive linear relationships were detected between the TL of mature females and ovarian and uterine fecundities. Mustelus punctulatus is an opportunistic predator that consumes a wide range of demersal and benthic prey items. It preys mainly on crustaceans, teleosts and molluscs. Polychaetes, sipunculids, echinoderms and tunicates are also consumed. The species change their main food item as they grow, from crustaceans to teleosts then to molluscs.

  14. Antimicrobial peptides in marine invertebrate health and disease.

    Science.gov (United States)

    Destoumieux-Garzón, Delphine; Rosa, Rafael Diego; Schmitt, Paulina; Barreto, Cairé; Vidal-Dupiol, Jeremie; Mitta, Guillaume; Gueguen, Yannick; Bachère, Evelyne

    2016-05-26

    Aquaculture contributes more than one-third of the animal protein from marine sources worldwide. A significant proportion of aquaculture products are derived from marine protostomes that are commonly referred to as 'marine invertebrates'. Among them, penaeid shrimp (Ecdysozosoa, Arthropoda) and bivalve molluscs (Lophotrochozoa, Mollusca) are economically important. Mass rearing of arthropods and molluscs causes problems with pathogens in aquatic ecosystems that are exploited by humans. Remarkably, species of corals (Cnidaria) living in non-exploited ecosystems also suffer from devastating infectious diseases that display intriguing similarities with those affecting farmed animals. Infectious diseases affecting wild and farmed animals that are present in marine environments are predicted to increase in the future. This paper summarizes the role of the main pathogens and their interaction with host immunity, with a specific focus on antimicrobial peptides (AMPs) and pathogen resistance against AMPs. We provide a detailed review of penaeid shrimp AMPs and their role at the interface between the host and its resident/pathogenic microbiota. We also briefly describe the relevance of marine invertebrate AMPs in an applied context.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. © 2016 The Author(s).

  15. Effects of estrogen exposure in mussels, Mytilus edulis, at different stages of gametogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Ciocan, Corina M.; Cubero-Leon, Elena; Puinean, Alin M.; Hill, Elizabeth M. [Department of Biology and Environmental Science, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ (United Kingdom); Minier, Christophe [Laboratoire d' Ecotoxicologie, Universite du Havre, 25 Rue Philippe Lebon, BP540, 766058 Le Havre (France); Osada, Makoto [Laboratory of Aquacultural Biology, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-amamiyamachi, Sendai 981-8555 (Japan); Fenlon, Kate [Department of Biology and Environmental Science, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ (United Kingdom); Rotchell, Jeanette M., E-mail: j.rotchell@sussex.ac.u [Department of Biology and Environmental Science, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ (United Kingdom)

    2010-09-15

    Mytilus edulis were exposed to 17{beta}-estradiol (E2) and the synthetic estrogens ethinyl estradiol (EE2) and estradiol benzoate (EB) for 10 days. Two exposures were performed to determine their effect on vitellogenin (VTG) and estrogen receptor 2 (ER2) mRNA expression at different stages of the reproductive cycle. Significant natural variation was not observed in VTG mRNA expression, though ER2 mRNA expression displayed significantly lower values during January, February and July compared with other times of the year. A significant increase in VTG and ER2 mRNA expression was observed in mussels exposed to estrogens at the early stage of gametogenesis. In contrast, mature mussels displayed no statistically significant change in the VTG or ER2 mRNA expression. The data presented suggests that the reproductive physiology of molluscs, in terms of VTG and ER2 mRNA expression, may be susceptible to damage by environmental estrogens at certain points in their gametogenesis process. - This study concerns vitellogenin and estrogen receptor mRNA expression in a mollusc and is relevant to those studying endocrine disruption in invertebrate species.

  16. Heterozygosity and fitness: No strong association in Great Lakes populations of the zebra mussel, Dreissena Polymorpha (Pallas)

    Science.gov (United States)

    Lewis, K.M.; Feder, J.L.; Horvath, T.G.; Lamberti, G.A.

    2000-01-01

    A number of studies have found positive associations between allozyme heterozygosity and fitness surrogates (e.g., body size and growth rate) for marine molluscs. We investigated whether similar relationships exist for freshwater populations of the zebra mussel, Dreissena polymorpha. Only one significant correlation between multi-locus heterozygosity and shell length was observed for a total of 22 D. polymorpha populations surveyed from midwestern U.S.A. lakes and streams, and the result was not significant on a table-wide basis. Meta-analysis revealed a significant common correlation coefficient (effect magnitude) between multi-locus heterozygosity and shell length across all 22 sites (rc = 0.052, P = 0.019, 1557 df). However, the variance in shell length explained by multi-locus heterozygosity was small (rc2 = 0.0027), implying a weak causal relationship if any. Also, we saw no relationship between heterozygosity and growth rate in a one-year field enclosure experiment. A significant heterozygosity-shell length correlation previously reported for a zebra mussel population at Put-in-Bay, Lake Erie, Ohio, may have been the product of unique population dynamics, rather than natural selection. Similar demographic considerations may contribute to inconsistencies in heterozygosity-fitness correlations seen for other molluscs.

  17. Risk assessment for human health and terrestrial ecosystem under chronic radioactive pollution near regional radioactive waste storage

    Science.gov (United States)

    Lavrentyeva, G. V.; Katkova, M. N.; Shoshina, R. R.; Synzynys, B. I.

    2017-01-01

    An impact of the radioactive waste storage facility at the regional population was assessed under supervision of IAEA. It was made in accordance with the methodology for assessment of doses and risks to human storage using different scenarios of radionuclides releases into the environment. The following scenarios were considered: leakage of fluid, resuspension of dust, fire, flooding. Thy evaluation of radiation doses received and the risks to the human showed that the risk has been acceptable for all scenarios. An approach for an ecological risk assessment for terrestrial ecosystem is presented as five modules: selection of the ecosystem-receptor of radiation effects; determination of reference species of living organisms and their survival indices; the critical load as an absorbed dose rate is calculated from the dependence between the absorbed Sr-90 radiation dose rate and the coefficient of radioactive strontium accumulation in mollusc shells; the critical dose; risk is assessed from a part of the ecosystem territory with increased mollusc loading; uncertainties appeared at each stage of risk assessment are characterized. The risk of exposure to the repository on the ecosystem should be characterized as unacceptable.

  18. Laboratory scale photobioreactor for high production of microalgae Rhodomonas salina used as food for intensive copepod cultures

    DEFF Research Database (Denmark)

    Thuy, Minh Vu Thi; Jepsen, Per Meyer; Hansen, Benni Winding

    Introduction Microalgae are essential feeds for many cultured molluscs, larvae of marine fishes, crustaceans as well as other important live feeds including rotifers, Artemia and copepods (Muller-Feuga, 2000). Microalgae are grown either in open culture systems (ponds) or closed systems (photobio......Introduction Microalgae are essential feeds for many cultured molluscs, larvae of marine fishes, crustaceans as well as other important live feeds including rotifers, Artemia and copepods (Muller-Feuga, 2000). Microalgae are grown either in open culture systems (ponds) or closed systems...... for copepods (Støttrup and Jensen, 1990; Zhang et al., 2013). Despite the benefit of using R. salina in cultivation of copepods, to our knowledge, there is no report on the production of this microalga at industrial scale to supply sufficient food for mass production of copepods. We intend to conduct the basic...... was cultivated continuously at temperature of 20ºC and salinity of 30ppt in two tubular PBRs with addition of CO2. The experiment was run two times and each PBR in 18 - 30 days. Periodically, the algae were sampled for analyzing the growth, biochemical composition and production. An exponential light model...

  19. Measurement of the oxygen binding properties of haemocyanin with the aid of a thin-layer optical cell

    Directory of Open Access Journals (Sweden)

    W. J. van Aardt

    1992-07-01

    Full Text Available The merits of the thin-layer method of Dolman and Gill to study the oxygen binding of haemocyanin were experimentally tested with haemocyanin obtained from arthropods and molluscs. The results show that, spectrophotometrically, oxyhaemocyanin from both arthropods and molluscs has a prominent absorption peak between 335 and 345 nm. Haemocyanin is more stable in the thin- layer preparation when compared with haemoglobin. At 35 °C a decrease in the initial absorbance value of less than 2% was found after three hours. For haemoglobin the initial value decreases nearly 10% during the same period. For a high-affinity haemocyanin such as Marisa cornuarietis (P⁵⁰ = 1,07 mmHg the thin-layer method of Dolman and Gill (1978 shows better PO₂ resolution than other methods. The reason for this is that the dilution valve, which is absent in other thin-layer methods, intrinsically measures the resultant PO₂ values at very low tensions more accurately. In this study a step-by-step explanation of the technique is given. The calculations have been explained using real figures and examples. It is hoped that this detailed description will make this technique more readily available for use by respiratory physiologists.

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

    Science.gov (United States)

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

    2009-02-01

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

  1. First report of Angiostrongylus cantonensis (Nematoda: Metastrongylidae in Achatina fulica (Mollusca: Gastropoda from Southeast and South Brazil

    Directory of Open Access Journals (Sweden)

    Arnaldo Maldonado Júnior

    2010-11-01

    Full Text Available The rat lungworm Angiostrongylus cantonensis is a worldwide-distributed zoonotic nematode that can cause human eosinophilic meningoencephalitis. Here, for the first time, we report the isolation of A. cantonensis from Achatina fulica from two Brazilian states: Rio de Janeiro (specifically the municipalities of Barra do Piraí, situated at the Paraiba River Valley region and São Gonçalo, situated at the edge of Guanabara Bay and Santa Catarina (in municipality of Joinville. The lungworms were identified by comparing morphological and morphometrical data obtained from adult worms to values obtained from experimental infections of A. cantonensis from Pernambuco, Brazil, and Akita, Japan. Only a few minor morphological differences that were determined to represent intra-specific variation were observed. This report of A. cantonensis in South and Southeast Brazil, together with the recent report of the zoonosis and parasite-infected molluscs in Northeast Brazil, provide evidence of the wide distribution of A. cantonensis in the country. The need for efforts to better understand the role of A. fulica in the transmission of meningoencephalitis in Brazil and the surveillance of molluscs and rodents, particularly in ports, is emphasized.

  2. First report of Angiostrongylus cantonensis (Nematoda: Metastrongylidae) in Achatina fulica (Mollusca: Gastropoda) from Southeast and South Brazil.

    Science.gov (United States)

    Maldonado, Arnaldo; Simões, Raquel O; Oliveira, Ana Paula M; Motta, Esther M; Fernandez, Mônica A; Pereira, Zilene M; Monteiro, Simone S; Torres, Eduardo J Lopes; Thiengo, Silvana Carvalho

    2010-11-01

    The rat lungworm Angiostrongylus cantonensis is a worldwide-distributed zoonotic nematode that can cause human eosinophilic meningoencephalitis. Here, for the first time, we report the isolation of A. cantonensis from Achatina fulica from two Brazilian states: Rio de Janeiro (specifically the municipalities of Barra do Piraí, situated at the Paraiba River Valley region and São Gonçalo, situated at the edge of Guanabara Bay) and Santa Catarina (in municipality of Joinville). The lungworms were identified by comparing morphological and morphometrical data obtained from adult worms to values obtained from experimental infections of A. cantonensis from Pernambuco, Brazil, and Akita, Japan. Only a few minor morphological differences that were determined to represent intra-specific variation were observed. This report of A. cantonensis in South and Southeast Brazil, together with the recent report of the zoonosis and parasite-infected molluscs in Northeast Brazil, provide evidence of the wide distribution of A. cantonensis in the country. The need for efforts to better understand the role of A. fulica in the transmission of meningoencephalitis in Brazil and the surveillance of molluscs and rodents, particularly in ports, is emphasized.

  3. Risk assessment for human health and terrestrial ecosystem under chronic radioactive pollution near regional radioactive waste storage

    International Nuclear Information System (INIS)

    Lavrentyeva, G V; Katkova, M N; Shoshina, R R; Synzynys, B I

    2017-01-01

    An impact of the radioactive waste storage facility at the regional population was assessed under supervision of IAEA. It was made in accordance with the methodology for assessment of doses and risks to human storage using different scenarios of radionuclides releases into the environment. The following scenarios were considered: leakage of fluid, resuspension of dust, fire, flooding. Thy evaluation of radiation doses received and the risks to the human showed that the risk has been acceptable for all scenarios. An approach for an ecological risk assessment for terrestrial ecosystem is presented as five modules: selection of the ecosystem-receptor of radiation effects; determination of reference species of living organisms and their survival indices; the critical load as an absorbed dose rate is calculated from the dependence between the absorbed Sr-90 radiation dose rate and the coefficient of radioactive strontium accumulation in mollusc shells; the critical dose; risk is assessed from a part of the ecosystem territory with increased mollusc loading; uncertainties appeared at each stage of risk assessment are characterized. The risk of exposure to the repository on the ecosystem should be characterized as unacceptable. (paper)

  4. Diversity patterns and freshwater molluscs similarities in small water reservoirs

    Directory of Open Access Journals (Sweden)

    Tomáš Čejka

    2011-02-01

    Full Text Available The survey presents the molluscan fauna from six impoundment systems of two sides (NW and SE of the Small Carpathians. Altogether 25 species (15 gastropod and 10 bivalve species were identified in reservoirs and their subsystems (inflows and outlets. The number of species per site ranged from 2 to 12, the mean number of species per site was 7. The mean number of individuals per site ranged from 15 to 905 (mean 174 ind/m2. Radix auricularia, R. ovata, Gyraulus albus, Gyraulus parvus/laevis, Hippeutis complanatus and Pisidium casertanum were present in more than 50% of reservoirs. The most abundant and frequent species in the entire area and all subsystems were Pisidium casertanum, Pisidium subtruncatum and Gyraulus parvus/laevis. Faunistic similarity indices indicate moderate degree of beta diversity i.e., differentiation among the sites; good separation of sites by cluster analysis indicates a different composition among inflows/outlets and littoral molluscan faunas of reservoirs.

  5. Growth and reproduction of two molluscs from an exposed sandy ...

    African Journals Online (AJOL)

    greater size on Maitland River beach than on any other beach in the ... tions suggests that large quantities of available food in the form of carrion ... was done in preference to treating shells with hydrochloric acid and ...... numerous birds and fishes the only defmite predators to date are the ... Low predation is therefore the.

  6. Evolution of the AKH/corazonin/ACP/GnRH receptor superfamily and their ligands in the Protostomia

    DEFF Research Database (Denmark)

    Hauser, Frank; Grimmelikhuijzen, Cornelis

    2014-01-01

    In this review we trace the evolutionary connections between GnRH receptors from vertebrates and the receptors for adipokinetic hormone (AKH), AKH/corazonin-related peptide (ACP), and corazonin from arthropods. We conclude that these G protein-coupled receptors (GPCRs) are closely related and hav......QLTFSSDWSGamide), and the penis worm Priapulus caudatus (pQIFFSKGWRGamide). This is the first report, showing that AKH signaling is widespread in molluscs....

  7. Natural capacity of radioactivity fixing by marine components in the Romanian sector of the Black Sea

    International Nuclear Information System (INIS)

    Patrascu, V.

    1992-01-01

    The natural capacity of radioactivity fixing by marine components is determined from a qualitative viewpoint by using concentration factors. Estimates are made for 271 samples of sediment macro-algae, molluscs and fish, collected from the Danube Mouths - Mangalia area, during 1983 - 1991. Natural and artificial radionuclides are studied (K-40, Ac-228, Ra-226, Co-60, Ag-110 m, Ru-106, Cs-135, and Cs-137). (Author)

  8. Alien species in the Mediterranean Sea by 2012. A contribution to the application of European Union’s Marine Strategy Framework Directive (MSFD. Part 2. Introduction trends and pathways

    Directory of Open Access Journals (Sweden)

    Α. ZENETOS

    2012-12-01

    Full Text Available More than 60 marine non-indigenous species (NIS have been removed from previous lists and 84 species have been added, bringing the total to 986 alien species in the Mediterranean [775 in the eastern Mediterranean (EMED, 249 in the central Mediterranean (CMED, 190 in the Adriatic Sea (ADRIA and 308 in the western Mediterranean (WMED]. There were 48 new entries since 2011 which can be interpreted as approximately one new entry every two weeks. The number of alien species continues to increase, by 2-3 species per year for macrophytes, molluscs and polychaetes, 3-4 species per year for crustaceans, and 6 species per year for fish. The dominant group among alien species is molluscs (with 215 species, followed by crustaceans (159 and polychaetes (132. Macrophytes are the leading group of NIS in the ADRIA and the WMED, reaching 26-30% of all aliens, whereas in the EMED they barely constitute 10% of the introductions. In the EMED, molluscs are the most species-rich group, followed by crustaceans, fish and polychaetes. More than half (54% of the marine alien species in the Mediterranean were probably introduced by corridors (mainly Suez. Shipping is blamed directly for the introduction of only 12 species, whereas it is assumed to be the most likely pathway of introduction (via ballasts or fouling of another 300 species. For approximately 100 species shipping is a probable pathway along with the Suez Canal and/or aquaculture. Approximately 20 species have been introduced with certainty via aquaculture, while >50 species (mostly macroalgae, occurring in the vicinity of oyster farms, are assumed to be introduced accidentally as contaminants of imported species. A total of 18 species are assumed to have been introduced by the aquarium trade. Lessepsian species decline westwards, while the reverse pattern is evident for ship-mediated species and for those introduced with aquaculture. There is an increasing trend in new introductions via the Suez Canal and via

  9. Differentiation of MIS 9 and MIS 11 in the continental record: vegetational, faunal, aminostratigraphic and sea-level evidence from coastal sites in Essex, UK

    Science.gov (United States)

    Roe, Helen M.; Coope, G. Russell; Devoy, Robert J. N.; Harrison, Colin J. O.; Penkman, Kirsty E. H.; Preece, Richard C.; Schreve, Danielle C.

    2009-11-01

    Multidisciplinary investigations of the vegetational, faunal and sea-level history inferred from the infills of buried channels on the coast of eastern Essex have a direct bearing on the differentiation of MIS 11 and MIS 9 in continental records. New data are presented from Cudmore Grove, an important site on Mersea Island that can be linked to the terrace sequence of the River Thames. The vegetational history has been reconstructed from a pollen sequence covering much of the interglacial represented. The temperate nature of the climate is apparent from a range of fossil groups, including plant remains, vertebrates (especially the rich herpetofauna), molluscs and beetles, which all have strong thermophilous components. The beetle data have been used to derive a Mutual Climatic Range reconstruction, suggesting that mean July temperatures were about 2 °C warmer than modern values for southeast England, whereas mean January temperatures may have been slightly colder. The sea-level history has been reconstructed from the molluscs, ostracods and especially the diatoms, which indicate that the marine transgression occurred considerably earlier in the interglacial cycle than at the neighbouring Hoxnian site at Clacton. There are a number of palynological similarities between the sequence at Cudmore Grove and Clacton, especially the presence of Abies and the occurrence of Azolla filiculoides megaspores. Moreover, both sites have yielded Palaeolithic archaeology, indeed the latter is the type site of the Clactonian (flake-and-core) industry. However, the sites can be differentiated on the basis of mammalian biostratigraphy, new aminostratigraphic data, as well as the differences in the sea-level history. The combined evidence suggests that the infill of the channel at Cudmore Grove accumulated during MIS 9, whereas the deposits at Clacton formed during MIS 11. The infill of a much later channel, yielding non-marine molluscs and vertebrates including Hippopotamus, appears

  10. Comprehensive characterization of the acute and chronic toxicity of the neonicotinoid insecticide thiamethoxam to a suite of aquatic primary producers, invertebrates, and fish.

    Science.gov (United States)

    Finnegan, Meaghean C; Baxter, Leilan R; Maul, Jonathan D; Hanson, Mark L; Hoekstra, Paul F

    2017-10-01

    Thiamethoxam is a neonicotinoid insecticide used widely in agriculture to control a broad spectrum of chewing and sucking insect pests. Recent detection of thiamethoxam in surface waters has raised interest in characterizing the potential impacts of this insecticide to aquatic organisms. We report the results of toxicity testing (acute and chronic) conducted under good laboratory practices for more than 30 freshwater species (insects, molluscs, crustaceans, algae, macrophytes, and fish) and 4 marine species (an alga, a mollusc, a crustacean, and a fish). As would be anticipated for a neonicotinoid, aquatic primary producers and fish were the least sensitive organisms tested, with acute median lethal and effect concentrations (LC50/EC50) observed to be ≥80 mg/L in all cases, which far exceeds surface water exposure concentrations. Tested molluscs, worms, and rotifers were similarly insensitive (EC50 ≥ 100 mg/L), except for Lumbriculus sp., with an EC50 of 7.7 mg/L. In general, insects were the most sensitive group in the study, with most acute EC50 values insects (acute EC50 insects (EC50 > 5.5 mg/L). The most sensitive chronic response was for Chironomus riparius, with a 30-d no-observed-effect concentration (NOEC; emergence) of 0.01 mg/L. Observed toxicity to the tested marine organisms was comparable to that of freshwater species. We used the reported data to construct species sensitivity distributions for thiamethoxam, to calculate 5% hazard concentrations (HC5s) for acute data (freshwater invertebrates), and compared these with measured concentrations from relevant North American surface waters. Overall, based on acute toxicity endpoints, the potential acute risk to freshwater organisms was found to be minimal (likelihood of exceeding HC5s < 1%). Environ Toxicol Chem 2017;36:2838-2848. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. © 2017 The Authors. Environmental

  11. A systematic review of animal predation creating pierced shells: implications for the archaeological record of the Old World.

    Science.gov (United States)

    Kubicka, Anna Maria; Rosin, Zuzanna M; Tryjanowski, Piotr; Nelson, Emma

    2017-01-01

    The shells of molluscs survive well in many sedimentary contexts and yield information about the diet of prehistoric humans. They also yield evidence of symbolic behaviours through their use as beads for body adornments. Researchers often analyse the location of perforations in shells to make judgements about their use as symbolic objects (e.g., beads), the assumption being that holes attributable to deliberate human behaviour are more likely to exhibit low variability in their anatomical locations, while holes attributable to natural processes yield more random perforations. However, there are non-anthropogenic factors that can cause perforations in shells and these may not be random. The aim of the study is compare the variation in holes in shells from archaeological sites from the Old World with the variation of holes in shells pierced by mollusc predators. Three hundred and sixteen scientific papers were retrieved from online databases by using keywords, (e.g., 'shell beads'; 'pierced shells'; 'drilling predators'); 79 of these publications enabled us to conduct a systematic review to qualitatively assess the location of the holes in the shells described in the published articles. In turn, 54 publications were used to assess the location of the holes in the shells made by non-human predators. Almost all archaeological sites described shells with holes in a variety of anatomical locations. High variation of hole-placement was found within the same species from the same site, as well as among sites. These results contrast with research on predatory molluscs, which tend to be more specific in where they attacked their prey. Gastropod and bivalve predators choose similar hole locations to humans. Based on figures in the analysed articles, variation in hole-location on pierced shells from archaeological sites was similar to variation in the placement of holes created by non-human animals. Importantly, we found that some predators choose similar hole locations to

  12. Determination of the variability of both hydrophilic and lipophilic toxins in endemic wild bivalves and carnivorous gastropods from the southern part of Chile.

    Science.gov (United States)

    Zamorano, Ruben; Marín, Michelle; Cabrera, Fabiola; Figueroa, Diego; Contreras, Cristóbal; Barriga, Andrés; Lagos, Néstor; García, Carlos

    2013-01-01

    The aim of this study was to analyse and determine the composition of paralytic shellfish poisoning (PSP) toxins and lipophilic toxins in the Region of Aysén, Chile, in wild endemic mussels (Mytilus chilensis, Venus antiqua, Aulacomya ater, Choromytilus chorus, Tagelus dombeii and Gari solida) and in two endemic carnivorous molluscs species (Concholepas concholepas and Argobuccinum ranelliforme). PSP-toxin contents were determined by using HPLC with fluorescence detection, while lipophilic toxins were determined by using LC-MS/MS. Mean concentrations for the total of PSP toxins were in the range 55-2505 μg saxitoxin-equivalent/100 g. The two most contaminated samples for PSP toxicity were bivalve Gari solida and carnivorous Argobuccinum ranelliforme with 2505 ± 101 and 1850 ± 137 μg saxitoxin-equivalent/100 g, respectively (p < 0.05). The lipophilic toxins identified were okadaic acid, dinophysistoxin-1 (DTX-1), azaspiracid-1 (AZA-1), pectenotoxin-2 (PTX-2) and yessotoxins (YTX). All analysed molluscs contained lipophilic toxins at levels ranging from 56 ± 4.8 to 156.1 ± 8.2 μg of okadaic acid-equivalent/kg shellfish together with YTX at levels ranging from 1.0 ± 0.1 to 18 ± 0.9 μg of YTX-equivalent/kg shellfish and AZA at levels ranging from 3.6 ± 0.2 to 31 ± 2.1 μg of AZA-equivalent/kg shellfish. Furthermore, different bivalves and gastropods differ in their capacity of retention of lipophilic toxins, as shown by the determination of their respective lipophilic toxins levels. In all the evaluated species, the presence of lipophilic toxins associated with biotransformation in molluscs and carnivorous gastropods was not identified, in contrast to the identification of PSP toxins, where the profiles identified in the different species are directly related to biotransformation processes. Thus, this study provides evidence that the concentration of toxins in the food intake of the evaluated species (Bivalvia and Gastropoda class) determines the degree of

  13. The influence of seagrass on shell layers and Florida Bay mudbanks

    Science.gov (United States)

    Prager, E.J.; Halley, R.B.

    1999-01-01

    Aerial photography indicates that sometime since the early 1970's, an emergent ridge of shell debris developed on a mudbank north of Calusa Key in Florida Bay. Coarse shell deposits on and within the Bay's shallow mudbanks are believed to be the product of transport during major storm events and subsequent winnowing. However, shell material from the ridge contains nuclear bomb 14C, supporting formation within the past 30 years and the last major hurricanes to influence Florida Bay were Donna and Betsy (1960 and 1965). Results from this study suggest that the Calusa ridge and other coarse shell deposits in Florida Bay can result from, 1) periodic seagrass mortality and wave-induced transport during frequent winter cold fronts and/or 2) mollusc blooms and subsequent burial. A survey of bottom types indicates that dense to intermediate beds of seagrass, mainly Thalassia testudinum (turtle grass), occur within the shallow basins of western Florida Bay and along the margins of Bay mudbanks. Wave measurements and modeling indicate that Thalassia along mudbank margins can reduce incoming wave-energy by over 80%. Seagrass beds also host particularly dense populations of molluscs from periodic 'blooms' and are believed to be the major source of coarse sediments in the Bay. Thus, if bank-edge seagrass dies, sediments, including shell debris, become exposed and subject to greatly increased wave energy. Modeling indicates that winds typical of winter cold fronts in South Florida can produce near-bottom velocities and shear stress at a grass-free bank edge which are sufficient to transport coarse carbonate grains. Shell layers found at depth in mudbank cores can also be explained by previous episodes of sediment accretion over mollusc-rich seagrass beds or grass bed mortality at the edge of a mudbank and shell transport during cold front passage. The latter implies that mortality of marginal seagrass beds has occurred throughout the history of Florida Bay and that the

  14. A neurotropic herpesvirus infecting the gastropod, abalone, shares ancestry with oyster herpesvirus and a herpesvirus associated with the amphioxus genome

    Directory of Open Access Journals (Sweden)

    Sawbridge Tim

    2010-11-01

    Full Text Available Abstract Background With the exception of the oyster herpesvirus OsHV-1, all herpesviruses characterized thus far infect only vertebrates. Some cause neurological disease in their hosts, while others replicate or become latent in neurological tissues. Recently a new herpesvirus causing ganglioneuritis in abalone, a gastropod, was discovered. Molecular analysis of new herpesviruses, such as this one and others, still to be discovered in invertebrates, will provide insight into the evolution of herpesviruses. Results We sequenced the genome of a neurotropic virus linked to a fatal ganglioneuritis devastating parts of a valuable wild abalone fishery in Australia. We show that the newly identified virus forms part of an ancient clade with its nearest relatives being a herpesvirus infecting bivalves (oyster and, unexpectedly, one we identified, from published data, apparently integrated within the genome of amphioxus, an invertebrate chordate. Predicted protein sequences from the abalone virus genome have significant similarity to several herpesvirus proteins including the DNA packaging ATPase subunit of (putative terminase and DNA polymerase. Conservation of amino acid sequences in the terminase across all herpesviruses and phylogenetic analysis using the DNA polymerase and terminase proteins demonstrate that the herpesviruses infecting the molluscs, oyster and abalone, are distantly related. The terminase and polymerase protein sequences from the putative amphioxus herpesvirus share more sequence similarity with those of the mollusc viruses than with sequences from any of the vertebrate herpesviruses analysed. Conclusions A family of mollusc herpesviruses, Malacoherpesviridae, that was based on a single virus infecting oyster can now be further established by including a distantly related herpesvirus infecting abalone, which, like many vertebrate viruses is neurotropic. The genome of Branchiostoma floridae (amphioxus provides evidence for the

  15. Měkkýši navrhované PR Údolí Vrchlice u Kutné Hory

    Directory of Open Access Journals (Sweden)

    Lucie Juřičková

    2009-12-01

    Full Text Available This paper brings the first malacological research of the proposal nature reserve Vrchlice Valley (Central Bohemia, Czech Republic after hundred years. Altogether, 44 mollusc species have been recorded in a very diverse mosaic of floodplain forests, cliffs and meadows. Rare or locally important species Vertigo pusilla, Semilimax semilimax, Daudebardia rufa, Isognomostoma isognomostomos, Oxyloma elegans, Vitrea crystallina and Laciniaria plicata were recorded in the area of the reserve.

  16. Os polimorfos de carbonato de cálcio: uma síntese fácil de aragonita

    OpenAIRE

    Bessler,Karl E.; Rodrigues,Laécio C.

    2008-01-01

    Aragonite is a metastable polymorph of calcium carbonate. The calcareous exoskeletons of some organisms like corals or molluscs consist essentially of aragonite. The questions of how, and why these organisms prefer the thermodynamically unstable aragonite for the construction of their hard shells are discussed. The importance of the biomineralization process for the development of new materials is outlined. In the experimental part, a very simple synthesis of polycrystalline aragonite is perf...

  17. Concentration of 137Cs by certain species of fresh water invertebrates

    International Nuclear Information System (INIS)

    Nilov, V.I.

    1983-01-01

    Results of experimental studies on 137 Cs accumulation by fresh-water invertebrates of various taxonomic groups are given. The invertebrate 137 Cs accumulative ability depends on the species belonging, age and sex of the animal. Radionuclide deposition by Cladocera depends on water temperature. Mollusc embryons need different quantities of cerium for their development. An appreciable role in 137 Cs extraction from fresh water is attributed to fry, adult Gammarus and Daphnia

  18. The Chernobyl reactor accident and its impact on the aquatic environment (marine and freshwater)

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    The impact of the Chernobyl reactor accident of 1986 on the freshwater and marine environment of the British Isles is discussed. Particular reference is made to the monitoring of radionuclide concentrations in foodstuffs such as shellfish, molluscs, trout, watercress and laverbread and the possible restrictions on their consumption by the public. Attention is drawn to the effects of the accident on the marine environment in a wider context. (U.K.)

  19. Microfacies and microfossils in Upper Jurassic limestones from Cheile Turenilor

    Directory of Open Access Journals (Sweden)

    Emanoil Săsăran

    2001-09-01

    Full Text Available In the Cheile Turenilor (Tureni Gorges area, a carbonate succession about 150 m thick developed on top of island arc magmatites. It mainly consist of gravity - induced deposits (debris flows, mass flows and grain flows. Coral, sponges and stromatoporoid bioconstructions are associated. Microbolites play an important role, as binders of the intraclastic rudstones/ grainstones facies, as well as of the incorporated corals, sponges, stromatoporoids, bryozoans, molluscs.

  20. Tributyltin (TBT) inhibition of oligomycin-sensitive Mg-ATPase activity in mussel mitochondria.

    Science.gov (United States)

    Pagliarani, Alessandra; Bandiera, Patrizia; Ventrella, Vittoria; Trombetti, Fabiana; Pirini, Maurizio; Nesci, Salvatore; Borgatti, Anna Rosa

    2008-06-01

    Tributyltin (TBT), one of the most toxic lipophilic aquatic pollutants, can be efficiently incorporated from sea water and sediments by filter-feeding molluscs. As far as we are aware TBT effects on the mitochondrial oligomycin-sensitive Mg-ATPase, the enzymatic core of energy production and a known target of TBT toxicity in mammals, have not been yet investigated in molluscs; thus the hydrolytic capability of the mitochondrial complex in the presence of micromolar concentrations of TBT was assayed in the mussel Mytilus galloprovincialis. Gill and mantle ATPase activities were progressively depressed by increasing TBT doses up to a maximal inhibition (82% in the gills and 74% in the mantle) at 0.62 microM TBT. Non-cooperative inhibition kinetics (n(H) approximately -1) and a non-competitive mechanism with respect to ATP substrate were pointed out. The mitochondrial Mg-ATPase susceptivity to TBT in the marine mussel was consistent with the formation of a TBT-Mg-ATPase complex, apparently more stable in the gills than in the mantle. The complex shape of the dose-response curve and the partial release of Mg-ATPase inhibition within the 0.6-34.4 microM TBT range suggest multiple interactions of TBT with the enzyme complex putatively related to its molecular mechanism of toxicity.

  1. Exposure to TBT increases accumulation of lipids and alters fatty acid homeostasis in the ramshorn snail Marisa cornuarietis.

    Science.gov (United States)

    Janer, Gemma; Navarro, Juan Carlos; Porte, Cinta

    2007-09-01

    Recent studies have shown that organotin compounds affect lipid homeostasis in vertebrates, probably through interaction with RXR and/or PPARgamma receptors. Molluscs are sensitive species to the toxic effects of tributyltin (TBT), particularly to masculinization, and TBT has been recently shown to bind to molluscs RXR. Thus, we hypothesized that exposure to TBT could affect lipid homeostasis in the ramshorn snail Marisa cornuarietis. For comparative purposes, the synthetic androgen methyl-testosterone (MT) was included in the study due to its masculinization effects, but its lack of binding to the RXR receptor. M. cornuarietis was exposed to different concentrations of TBT (30, 125, 500 ng/L as Sn) and MT (30, 300 ng/L) for 100 days. Females exposed to 500 ng/L TBT showed increased percentage of lipids and increased levels of fatty acids in the digestive gland/gonad complex (2- to 3-fold). In addition, fatty acid profiles were altered in both males and females exposed to 125 and 500 ng/L TBT. These effects were not observed in females exposed to MT. Overall, this work suggest that TBT acts as a potent inducer of lipid and fatty acid accumulation in M. cornuarietis as shown in vertebrate studies earlier, and that sex differences in sensitivity do exist.

  2. Responses of the molluscan fauna to environmental variations in a Halodule wrightii Ascherson ecosystem from Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    KCRISHNA V.S. BARROS

    2013-10-01

    Full Text Available ABSTRACT This study observed the spatial and temporal distributions of molluscs in a Halodule wrightii meadow, verifying if they respond satisfactorily to seasonal changes in this seagrass ecosystem. Twenty-four species were identified. Chitons were rare, bivalves had greater number of species (11, followed by gastropods (9 which were also the most abundant class (73%. All classes were more abundant in the belowground. The most common species was Tricolia affinis, especially in aboveground. The occurrence of some species in both strata or out of the expected stratum may have been influenced by shallow layer of the sediment considered in this study, hydrodynamic, and low biomass of the studied meadow. According to univariate and multivariate analyses, despite of molluscan descriptors had been related to variables associated with rainfall, the seagrasses had an important role on the seasonal and vertical variations of the molluscan fauna. The biomass of the epiphyte Hypnea musciformis was correlated to temporal variations of the species from aboveground, indicating its secondary role for this community. The molluscs were sensible to environmental variations, and also reflected seasonal changes of the seagrass, showing that damages on these meadows reflect even at lower levels of the marine food web.

  3. CASA in invertebrates.

    Science.gov (United States)

    van der Horst, Gerhard; Bennett, Monique; Bishop, John D D

    2018-04-09

    Sperm movement has been described in several phyla of invertebrates. Yet, sperm motility has only been quantified using computer-aided sperm analysis (CASA-Mot) in externally fertilising species (broadcast spawners) of two phyla, molluscs and echinoderms. In the present study we quantified in detail the nature of the sperm tracks, percentage motility groupings and detailed kinematics of rapid-, medium- and slow-swimming spermatozoa in the oyster Crassostrea gigas and four species never previously studied by CASA-Mot, namely the molluscs Choromytilus meridionalis, Donax serra and Haliotis midae and the echinoderm Parechinus angulosus. A feature common to all these species are the helical tracks, the diameter of which seems to be species specific. Using CASA-Mot, the behaviour of spermatozoa was also studied over time and in the presence of egg water and Ca2+ modulators such as caffeine and procaine hydrochloride. For the first time, we show that hyperactivation can be induced in all species in the presence of egg water (sea water that was mixed with mature eggs and then centrifuged) and/or caffeine, and these hyperactivated sperm tracks were characterised using CASA-Mot. We relate the different patterns of sperm motility and behaviour to reproductive strategies such as broadcast spawning and spermcasting, and briefly review studies using CASA-Mot on other invertebrates.

  4. First evidence of a potential antibacterial activity involving a laccase-type enzyme of the phenoloxidase system in Pacific oyster Crassostrea gigas haemocytes.

    Science.gov (United States)

    Luna-Acosta, Andrea; Saulnier, Denis; Pommier, Mylène; Haffner, Philippe; De Decker, Sophie; Renault, Tristan; Thomas-Guyon, Hélène

    2011-12-01

    Phenoloxidases (POs) are a group of copper proteins including tyrosinase, catecholase and laccase. In several insects and crustaceans, antibacterial substances are produced through the PO cascade, participating in the direct killing of invading microorganisms. However, although POs are widely recognised as an integral part of the invertebrate immune defence system, experimental evidence is lacking that these properties are conserved in molluscs, and more particularly in the Pacific oyster Crassostrea gigas. In the present study, Vibrio splendidus LGP32 and Vibrio aestuarianus 02/041 growths were affected, after being treated with C. gigas haemocyte lysate supernatant (HLS), and either a common substrate of POs, l-3,4-dihydroxyphenylalanine (L-DOPA), to detect catecholase-type PO activity, or a specific substrate of laccase, p-phenylenediamine (PPD), to detect laccase-type PO activity. Interestingly, a higher bacterial growth inhibition was observed in the presence of PPD than in the presence of L-DOPA. These effects were suppressed when the specific PO inhibitor, phenylthiourea (PTU), was added to the medium. Results of the present study suggest, for the first time in a mollusc species, that antibacterial activities of HLS from C. gigas potentially involve POs, and more particularly laccase catalysed reactions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Accumulation of platinum group elements by the marine gastropod Littorina littorea

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, Rachel [School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Turner, Andrew, E-mail: aturner@plymouth.ac.uk [School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2011-04-15

    The accumulation and trophic transfer of the platinum group elements (PGE): Rh, Pd and Pt; have been studied in short-term (5 day) exposures conducted in aquaria containing the marine macroalga, Ulva lactuca, and/or the grazing mollusc, Littorina littorea. Metals added to sea water (to concentrations of 20 {mu}g L{sup -1}) were taken up by U. lactuca in the order Rh, Pt > Pd and by L. littorea in the order Pd {>=} Pt {>=} Rh, with greatest metal accumulation in the latter generally occurring in the visceral complex and kidney. When fed contaminated alga, accumulation of Rh and Pd by L. littorea, relative to total available metal, increased by an order of magnitude, while accumulation of Pt was not readily detected. We conclude that the diet is the most important vector for accumulation of Rh and Pd, while accumulation of Pt appears to proceed mainly from the aqueous phase. - Research highlights: > Platinum group elements are accumulated by, Littorina littorea. > The aqueous phase and diet are important vehicles for Rh and Pd accumulation by the snail. > Grazing molluscs may serve as biomonitors of coastal PGE contamination. - Platinum group elements are accumulated by the marine snail, Littorina littorea, from both the aqueous phase and the diet.

  6. RUDI, a short interspersed element of the V-SINE superfamily widespread in molluscan genomes.

    Science.gov (United States)

    Luchetti, Andrea; Šatović, Eva; Mantovani, Barbara; Plohl, Miroslav

    2016-06-01

    Short interspersed elements (SINEs) are non-autonomous retrotransposons that are widespread in eukaryotic genomes. They exhibit a chimeric sequence structure consisting of a small RNA-related head, an anonymous body and an AT-rich tail. Although their turnover and de novo emergence is rapid, some SINE elements found in distantly related species retain similarity in certain core segments (or highly conserved domains, HCD). We have characterized a new SINE element named RUDI in the bivalve molluscs Ruditapes decussatus and R. philippinarum and found this element to be widely distributed in the genomes of a number of mollusc species. An unexpected structural feature of RUDI is the HCD domain type V, which was first found in non-amniote vertebrate SINEs and in the SINE from one cnidarian species. In addition to the V domain, the overall sequence conservation pattern of RUDI elements resembles that found in ancient AmnSINE (~310 Myr old) and Au SINE (~320 Myr old) families, suggesting that RUDI might be among the most ancient SINE families. Sequence conservation suggests a monophyletic origin of RUDI. Nucleotide variability and phylogenetic analyses suggest long-term vertical inheritance combined with at least one horizontal transfer event as the most parsimonious explanation for the observed taxonomic distribution.

  7. Angiostrongylus cantonensis and Rat Lungworm Disease in Brazil

    Science.gov (United States)

    de Oliveira Simões, Raquel; Fernandez, Monica Ammon; Júnior, Arnaldo Maldonado

    2013-01-01

    The metastrongyloid nematode genus Angiostrongylus includes 18 species, two of which are relevant from a medical standpoint, Angiostrongylus costaricensis and Angiostrongylus cantonensis. The first was described from Costa Rica in 1971 and causes abdominal angiostrongyliasis in the Americas, including in Brazil. Angiostrongylus cantonensis, first described in 1935 from Canton, China, is the causative agent of eosinophilic meningitis. The natural definitive hosts are rodents, and molluscs are the intermediate hosts. Paratenic or carrier hosts include crabs, freshwater shrimp, amphibians, flatworms, and fish. Humans become infected accidentally by ingestion of intermediate or paratenic hosts and the parasite does not complete the life cycle as it does in rats. Worms in the brain cause eosinophilic meningitis. This zoonosis, widespread in Southeast Asia and the Pacific islands, has now been reported from other regions. In the Americas there are records from the United States, Cuba, Jamaica, Brazil, Ecuador, and Haiti. In Brazil seven human cases have been reported since 2007 from the southeastern and northeastern regions. Epidemiological studies found infected specimens of Rattus norvegicus and Rattus rattus as well as many species of molluscs, including the giant African land snail, Achatina fulica, from various regions of Brazil. The spread of angiostrongyliasis is currently a matter of concern in Brazil. PMID:23901376

  8. Acute toxicity of birch tar oil on aquatic organisms

    Directory of Open Access Journals (Sweden)

    M. HAGNER

    2008-12-01

    Full Text Available Birch tar oil (BTO is a by-product of processing birch wood in a pyrolysis system. Accumulating evidence suggests the suitability of BTO as a biocide or repellent in terrestrial environments for the control of weeds, insects, molluscs and rodents. Once applied as biocide, BTO may end up, either through run-off or leaching, in aquatic systems and may have adverse effects on non-target organisms. As very little is known about the toxicity of BTO to aquatic organisms, the present study investigated acute toxicity (LC50/EC50 of BTO for eight aquatic organisms. Bioassays with the Asellus aquaticus (crustacean, Lumbriculus variegatus (oligochaeta worm, Daphnia magna (crustacean, Lymnea sp. (mollusc, Lemna minor (vascular plant, Danio rerio (fish, Scenedesmus gracilis (algae, and Vibrio fischeri (bacterium were performed according to ISO, OECD or USEPA-guidelines. The results indicated that BTO was practically nontoxic to most aquatic organisms as the median effective BTO concentrations against most organisms were >150 mg L-1. In conclusion, our toxicity tests showed that aquatic organisms are to some extent, invariably sensitive to birch tar oil, but suggest that BTO does not pose a severe hazard to aquatic biota. We deduce that, unless BTOs are not applied in the immediate vicinity of water bodies, no special precaution is required.;

  9. De novo characterisation of the greenlip abalone transcriptome (Haliotis laevigata) with a focus on the heat shock protein 70 (HSP70) family.

    Science.gov (United States)

    Shiel, Brett P; Hall, Nathan E; Cooke, Ira R; Robinson, Nicholas A; Strugnell, Jan M

    2015-02-01

    Abalone (Haliotis) are economically important molluscs for fisheries and aquaculture industries worldwide. Despite this, genomic resources for abalone and molluscs are still limited. Here we present a description and functional annotation of the greenlip abalone (Haliotis laevigata) transcriptome. We present a focused analysis on the heat shock protein 70 (HSP70) family of genes with putative functions affecting temperature stress and immunity. A total of ~38 million paired end Illumina reads were obtained, resulting in a Trinity assembly of 222,172 contigs with minimum length of 200 base pairs and maximum length of 33 kilobases. The 20,702 contigs were annotated with gene descriptions by BLAST. We created a program to maximise the number of functionally annotated genes, and over 10,000 contigs were assigned Gene ontologies (GO terms). By using CateGOrizer, immunity related GO terms for stressors such as heat, hypoxia, oxidative stress and wounding received the highest counts. Twenty-six contigs with homology to the HSP70 family of genes were identified. Ninety-one putative single-nucleotide polymorphisms were observed in the abalone HSP70 contigs. Eleven of these were considered non-synonymous. The annotated transcriptome described in this study will be a useful basis for future work investigating the genetic response of abalone to stress.

  10. Effects of tributyltin (TBT) and testosterone on the female genital system in the mesogastropod Littorina littorea (Prosobranchia)

    Science.gov (United States)

    Deutsch, U.; Fioroni, P.

    1996-03-01

    Experiments were performed with the mesogastropod Littorina littorea on Helgoland, in Roscoff, and in the laboratory in order to evaluate the reaction of the female genital system to TBT, an environmental toxicant. The snails were either injected with 50 or 100 ng tributyltin (TBT) soluted in ethanol or exposed to artificial sea water treated with 5, 50, 100, and 200 ng TBT/l, and 33 ng testosterone/l. The duration of the experiments was either four or eight weeks. None of the analysed female L. littorea showed signs of imposex. Compared to results for the control groups, the size of the female glandular complex was significantly reduced if the pre-experimental toxication was already high, as is the case in snails collected around Helgoland. TBT-related gland complex reduction occurs also in female L. littorea from other sampling sites. In addition, injection of ethanol also causes a decrease in gland size. The experimental results demonstrate that the distal female genital system responds with significantly lower sensitivity to TBT than that of other prosobranchs. This behaviour is ascribed to the lack of an androgen receptor at the ovipositor. The results further strengthen the case of the extreme rarity of imposex described for female L. littorea in natural habitats. However, strong TBT-toxication may affect L. littorea populations significantly because of increasing masculinization of the females, which reduces reproduction ability.

  11. Secondary ion mass spectrometry and environment. SIMS as applied to the detection of stable and radioactive isotopes in marine organisms

    International Nuclear Information System (INIS)

    Chassard-Bouchaud, C.; Escaig, F.; Hallegot, P.

    1984-01-01

    Several marine species of economical interest, Crustacea (crabs and prawns) and Molluscs (common mussels and oysters) were collected from coastal waters of France: English Channel, Atlantic Ocean and Mediterranean Sea and of Japan. Microanalyses which were performed at the tissue and cell levels, using Secondary Ion Mass Spectrometry, revealed many contaminants; stable isotopes as well as radioactive actinids such as uranium were detected. Uptake, storage and excretion target organs were identified [fr

  12. Sleep researchers need to bring Darwin on board: elucidating functions of sleep via adaptedness and natural selection

    OpenAIRE

    Kavanau, Julian L.

    2004-01-01

    The development of neural multifunctionality – given brain regions carrying out more than one function – conferred great efficiency on brain function at early stages of evolution. This applied to animals that led relatively simple lives with few needs for long-term memories, such as many lower invertebrates – many molluscs, echinoderms, worms, etc. As more complex lifestyles and detailed focal vision evolved, needs for self-initiated and reflexive activities increased in frequency, and recogn...

  13. Enterococcus spp. Resistant to Multiple Antimicrobial Drugs and Determination of Fecal Contamination Levels in Mangrove Oysters (Crassostrea rhizophorae)

    OpenAIRE

    Rubião, Cynthia Annes; Franco, Robson Maia; Mesquita, Eliana de Fátima Marques de; Miguel, Marco Antonio Lemos; Cabral, Claudius Couto; Fonseca, Ana Beatriz Monteiro

    2017-01-01

    ABSTRACT The aim of this study was to determine and compare the Most Probable Number (MPN) of Total Coliforms (TC), Escherichia coli and Enterococcus spp. and to characterize the antimicrobial resistance profiles of Enterococcus spp. isolated from oysters collected in the Barra de Guaratiba Mangrove, Rio de Janeiro, Brazil. The enumeration of E. coli has been used to indicate fecal contamination and hygienic-sanitary conditions of bivalve molluscs. Enterococci are capable to transfer several ...

  14. A Guide to the Principal Marine Fouling Organisms, with Particular Reference to Cockburn Sound, W.A.,

    Science.gov (United States)

    1982-07-01

    and crowned with long, feathery tentacles ( branchial filaments) which are used to draw food and oxygen from the water. The end of one filament is... branchial filaments. Tubes can reach 50 mm long and 0.5 mm diameter. Filograna can reproduce asexually with new individuals budded off parent worms and...the branchial crown of feeding tentacles seen in serpulids. Bivalves are the most significant of the fouling molluscs. The animal is laterally

  15. Acoustical Scattering, Propagation, and Attenuation Caused by Two Abundant Pacific Schooling Species: Humboldt Squid and Hake

    Science.gov (United States)

    2015-09-30

    an area important for acoustical testing and tactical exercises, the most abundant species by biomass is Pacific hake, Merluccius productus, a fish...scattering characteristics of the animal especially if the animal has eaten hard- shelled mollusc prey. Figure 7. A dorsal scan (similar to an x-ray) of a...kHz echogram. 11 In order to generate abundance and biomass estimates for organisms using active acoustics, one assumption that can be made is

  16. Hatchery-scale trials using cryopreserved spermatozoa of black-lip pearl oyster, Pinctada margaritifera

    OpenAIRE

    Hui, Belinda; Vonau, Vincent; Moriceau, Jacques; Tetumu, Roger; Vanaa, Vincent; Demoy-schneider, Marina; Suquet, Marc; Le Moullac, Gilles

    2011-01-01

    Cryopreservation is a valuable tool for genetic improvement programs. Several bivalve mollusc species have already been the subject of such programs and the Tahitian black pearl oyster industry is now planning the development of selective breeding for desirable traits in Pinctada margaritifera. The ability to cryopreserve spermatozoa would, therefore, offer significant benefits to the cultured black pearl industry. Spermatozoa were cryopreserved with CPA 0.7 M trehalose in 0.8 M Me2SO and...

  17. Salix transect of Europe: variation in ploidy and genome size in willow-associated common nettle, Urtica dioica L. sens. lat., from Greece to arctic Norway

    OpenAIRE

    Quentin Cronk; Oriane Hidalgo; Jaume Pellicer; Diana Percy; Ilia Leitch

    2016-01-01

    Abstract Background The common stinging nettle, Urtica dioica L. sensu lato, is an invertebrate "superhost", its clonal patches maintaining large populations of insects and molluscs. It is extremely widespread in Europe and highly variable, and two ploidy levels (diploid and tetraploid) are known. However, geographical patterns in cytotype variation require further study. New information We assembled a collection of nettles in conjunction with a transect of Europe from the Aegean to Arctic No...

  18. Prolonged Permian–Triassic ecological crisis recorded by molluscan dominance in Late Permian offshore assemblages

    OpenAIRE

    Clapham, Matthew E.; Bottjer, David J.

    2007-01-01

    The end-Permian mass extinction was the largest biotic crisis in the history of animal life, eliminating as many as 95% of all species and dramatically altering the ecological structure of marine communities. Although the causes of this pronounced ecosystem shift have been widely debated, the broad consensus based on inferences from global taxonomic diversity patterns suggests that the shift from abundant brachiopods to dominant molluscs was abrupt and largely driven by the catastrophic effec...

  19. Enewetak Marine Biological Laboratory 1973--1974 annual report. Final report

    International Nuclear Information System (INIS)

    1974-01-01

    Brief summaries are presented of ecological studies carried out at Enewetak from July 1973 through June 30, 1974. Data are included on the content of 90 Sr in the skeleton of coral. Other studies included measurements of the chemical composition of 60 marine animals; and the growth rate, interactions of prey populations, food supply, food chains, and population dynamics of communities of crustaceans, molluscs, corals, sponges, algae, reef fishes, and shore birds. (U.S.)

  20. Manipulations of adult density and juvenile habitat quality in Northern Abalone stock restoration

    OpenAIRE

    DeFreitas, Bart Andre

    2005-01-01

    Wild abalone populations throughout the world have declined dramatically over the past 40 years due primarily to market demands for the mollusc's edible foot. Northern abalone (Haliotis kamtschatkana), the only abalone species occurring in British Columbia (B.C.), is widely thought to be threatened by potential population collapse as a result of low adult densities that impair reproductive potential. This study examined the hypothesis that the abundance of wild northern abalone populations ar...

  1. Determination of radionuclides and trace elements in marine sediments and biota from the red sea coast

    International Nuclear Information System (INIS)

    Sirelkhatim, Dia Awad

    2002-09-01

    This study presents data on the concentration levels of natural ( 226 Ra, 210 Pb, 210 Po, 238 U, 234 Th and 40 K) and artificial ( 239+240 Pu, 238 Pu, 90 Sr, 137 Cs) radionuclides as well as trace metals (Pb, Sr, Cr, Ni, V, Ba, La, Ce, Rb, Zn, Nb, As, Ti, Mn, Y, Zr, Th, U, and Ga) in multicellular marine algae, molluscs, coral in surface marine sediments collected from the shallower waters of the fringing reefs area and Flamingo Bay near Port Sudan harbour. The analyses were performed using gamma spectrometry, alpha spectrometry, liquid scintillation counting technique, Cerenkov counting technique and X RF.Surface sediments from this coastal region are poor in their trace metals and radionuclide content compared to similar data reported from different coastal areas around the globe and no source of emission has appeared to make any significant contribution. Surface enrichment of 210 Pb and 210 Po with respect to their progenitor 226 Ra is evident from the activity ratios of 210 Pb/ 226 Ra (3.03±1.79) and 210 Po/ 226 Ra (2.23±1.56) indicating sources other than in situ decay of parent nuclide. Activity concentration ranges in mBq/Kg dry weight of the artificial radionuclides studied were found to be from 5.10 to 82 ( 239+240 Pu), from 0.89 to 8.63 ( 238 Pu),and from 29.6 to 389.5 ( 90 Sr). The ratio 239+240 Pu/ 238 Pu which is used for source term identification has confirmed that the origin of anthropogenic radioactivity in the studied area is mainly the global fall-out. 137 Cs was not detected in all samples analysed. Considering 238 U, 234 Th and 40 K, their activity concentration (Bq/Kg dry weight) ranges in sediments are 2.41-6.69, 27.3-79.4 and 462-656, respectively. 234 Th/ 238 U ratio was an order of magnitude higher than unity indicating that the sediments are from high productivity area with a high biogenic flux from the adjacent water. Among marine plants and animals investigated, the coral species, Favites, show substantial concentration of radium at

  2. Chemical diversity in opisthobranch molluscs from scarcely investigated Indo-Pacific areas

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; Guo, Y.-W.; Fakhr, I.M.I.; Mollo, E.

    on Nudibranchs Nudibranchs are exclusively carnivorous with a broad range of alimentary habits. They appear to have the ability to sequester, accumulate and modify dietary metabolites as well as to synthesize defensive compounds de novo (Cimino and Ghiselin... of the chemical data reviewed in this chapter, taking into account alimentary habits and geographical chemical variations, suggests some interesting generalizations. 8.6.1 Nudibranchs The intra-specific geographic variations observed in the chemical...

  3. Comparison between EDXRF and FAAS for Zn determination in terrestrial molluscs

    International Nuclear Information System (INIS)

    Melo, Julyanne T.B.; Cantinha, Rebeca S.; Santos, Mariana L.O.; Santos, Katarine M.B.; Franca, Elvis J.; Melo, Ana M.M.A.

    2015-01-01

    Even with the most advanced analytical techniques, achieving the true values of a given analyte in a sample cannot be an easy task. Energy Dispersive X-Ray Fluorescence (EDXRF) and Flame Atomic Absorption Spectrometry (FAAS) have been widely used for analysis of the chemical composition of biological matrices in environmental studies. However, depending on the sample matrix, a combination of techniques could be needed for the correct determination of the analyte. Zinc distribution in Littoraria angulifera and Melampus coffea is quite dependent on the environment, so that, diverse methods could be necessary to evaluate the chemical composition of these mollusks. This study aimed at the comparison between EDXRF and FAAS techniques for determining Zn in the soft tissues of terrestrial mollusks. The animals were collected in three mangroves in the State of Pernambuco, Brazil. After shell removal, tissues were lyophilized and milled in a mortar. Test portions of 500 mg were analyzed by EDXRF, followed by chemical treatment for FAAS analysis. For the quality of the analytical procedure, the standard reference material SRM 2976 Mussel Tissue was analyzed together with the samples. The results for the analysis of the certified reference material SRM 2976 indicated the quality of the analytical procedure for both techniques. Adjusted-R 2 between EDXRF and FAAS results was 0.95, indicating a good equivalence of Zn determination by both techniques. However, some improvement of EDXRF determination could be necessary because of the tendency of lower results compared to FAAS, probably related to spectral interferences during the analysis. (author)

  4. Heavy metal concentrations in marine molluscs from the Moroccan coastal region

    Energy Technology Data Exchange (ETDEWEB)

    Maanan, Mohamed [Geolittomer, UMR 6554 LETG - CNRS, Universite de Nantes, BP 81227, 44312 Nantes Cedex 3 (France)], E-mail: mohamed.maanan@univ-nantes.fr

    2008-05-15

    Mussels (Mytilus galloprovincialis), clams (Venerupis decussatus) and oysters (Crassostrea gigas) were sampled seasonally during 2004-2005, from different coastal environments of Morocco in order to measure their accumulated heavy metal concentrations. The concentrations of Hg and Pb were determined by AFS and ICP-MS methods, respectively, whilst the remaining metals (Cd, Cr, Cu, Mn, Zn and Ni) were quantified by AAS. The soft tissue concentrations of the mussels were on average 7.2 mg kg{sup -1} (Cd), 9.6 mg kg{sup -1} (Pb), 0.6 mg kg{sup -1} (Hg), 26.8 mg kg{sup -1} (Cu), 8.8 mg kg{sup -1} (Cr), 292 mg kg{sup -1} (Zn), 20.8 mg kg{sup -1} (Mn) and 32.8 mg kg{sup -1} (Ni). The highest tissue heavy metal concentrations were recorded in the south from the industrial area of Jorf Lasfar. The relationships between metal concentration and season in each species showed very similar annual profiles with a peak observed around spring-summer. Statistical analysis indicated that different species showed different bioaccumulation of metals depending on study site and season. - The accumulated metal concentrations in bivalves from the clean stations may be considered as useful Atlantic coast reference background levels for future comparison.

  5. Plant indicator values as a tool for land mollusc autecology assessment

    Czech Academy of Sciences Publication Activity Database

    Horsák, M.; Hájek, Michal; Tichý, L.; Juřičková, L.

    2007-01-01

    Roč. 32, č. 2 (2007), s. 161-171 ISSN 1146-609X Grant - others:GA AV ČR(CZ) KJB601630501 Program:KJ Institutional research plan: CEZ:AV0Z60050516 Keywords : Ellenberg indicator values * animal autecology assessment * species response curve Subject RIV: EF - Botanics Impact factor: 1.306, year: 2007

  6. Comparison between EDXRF and FAAS for Zn determination in terrestrial molluscs

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Julyanne T.B.; Cantinha, Rebeca S.; Santos, Mariana L.O.; Santos, Katarine M.B.; Franca, Elvis J., E-mail: julyanne.melo@ufpe.br, E-mail: rebecanuclear@gmail.com, E-mail: marianasantos_ufpe@hotmail.com, E-mail: katarine.mizan@gmail.com, E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Melo, Ana M.M.A., E-mail: amdemelo@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Biofisica e Radiobiologia

    2015-07-01

    Even with the most advanced analytical techniques, achieving the true values of a given analyte in a sample cannot be an easy task. Energy Dispersive X-Ray Fluorescence (EDXRF) and Flame Atomic Absorption Spectrometry (FAAS) have been widely used for analysis of the chemical composition of biological matrices in environmental studies. However, depending on the sample matrix, a combination of techniques could be needed for the correct determination of the analyte. Zinc distribution in Littoraria angulifera and Melampus coffea is quite dependent on the environment, so that, diverse methods could be necessary to evaluate the chemical composition of these mollusks. This study aimed at the comparison between EDXRF and FAAS techniques for determining Zn in the soft tissues of terrestrial mollusks. The animals were collected in three mangroves in the State of Pernambuco, Brazil. After shell removal, tissues were lyophilized and milled in a mortar. Test portions of 500 mg were analyzed by EDXRF, followed by chemical treatment for FAAS analysis. For the quality of the analytical procedure, the standard reference material SRM 2976 Mussel Tissue was analyzed together with the samples. The results for the analysis of the certified reference material SRM 2976 indicated the quality of the analytical procedure for both techniques. Adjusted-R{sup 2} between EDXRF and FAAS results was 0.95, indicating a good equivalence of Zn determination by both techniques. However, some improvement of EDXRF determination could be necessary because of the tendency of lower results compared to FAAS, probably related to spectral interferences during the analysis. (author)

  7. Molluscan assemblages of seagrass-covered and bare intertidal flats on the Banc d'Arguin, Mauritania, in relation to characteristics of sediment and organic matter

    Science.gov (United States)

    Honkoop, Pieter J. C.; Berghuis, Eilke M.; Holthuijsen, Sander; Lavaleye, Marc S. S.; Piersma, Theunis

    2008-11-01

    The Banc d'Arguin, a non-estuarine area of shallows and intertidal flats off the tropical Saharan coast of Mauritania, is characterised by extensive intertidal and subtidal seagrass beds. We examined the characteristics of intertidal seagrass ( Zostera noltii) meadows and bare areas in terms of the presence and abundance of molluscs (gastropods and bivalves). To explain observed differences between molluscan assemblages in seagrass and bare patches, some aspects of the feeding habitat (top-5 mm of the sediment) and of food (organic materials) of molluscs were examined. The novelty of this study is that phytopigments were measured and identified to assess source and level of decay (freshness) of organic material in the sediment and to study their importance as an explanatory variable for the distribution of molluscs. Over an area of 36 km 2 of intertidal flats, at 12 sites, paired comparisons were made between seagrass-covered and nearby bare patches. Within seagrass meadows, dry mass of living seagrass was large and amounted to 180 ±10 g AFDM m - 2 (range 75-240). Containing twice the amount of silt per unit dry sediment mass, seagrass sediments were muddier than bare areas; the relative amount of organic material was also larger. The total number of species of bivalves and gastropods amounted to 27, 14 of which were found only in seagrass areas, 4 only in bare and 9 in both types of habitat. Among the three numerically most abundant species, the bivalves Anadara senilis, Dosinia hepatica and Loripes lacteus, the first was numerically most abundant in bare and the other two in seagrass-covered areas. Bare intertidal areas had greater mean total biomass of molluscs (80.5 g AFDM m - 2 ) than seagrass meadows (30.0 g AFDM m - 2 ). In both habitats, the bulk of the biomass was made up by A. senilis. Excluding this species, bare mudflats contained on average only 3.1 g AFDM m - 2 and seagrass meadows 6.9 g AFDM m - 2 . As compared to previous surveys in 1980-1986, the

  8. Mitogenomics does not resolve deep molluscan relationships (yet?).

    Science.gov (United States)

    Stöger, I; Schrödl, M

    2013-11-01

    The origin of molluscs among lophotrochozoan metazoans is unresolved and interclass relationships are contradictory between morphology-based, multi-locus, and recent phylogenomic analyses. Within the "Deep Metazoan Phylogeny" framework, all available molluscan mitochondrial genomes were compiled, covering 6 of 8 classes. Genomes were reannotated, and 13 protein coding genes (PCGs) were analyzed in various taxon settings, under multiple masking and coding regimes. Maximum Likelihood based methods were used for phylogenetic reconstructions. In all cases, molluscs result mixed up with lophotrochozoan outgroups, and most molluscan classes with more than single representatives available are non-monophyletic. We discuss systematic errors such as long branch attraction to cause aberrant, basal positions of fast evolving ingroups such as scaphopods, patellogastropods and, in particular, the gastropod subgroup Heterobranchia. Mitochondrial sequences analyzed either as amino acids or nucleotides may perform well in some (Cephalopoda) but not in other palaeozoic molluscan groups; they are not suitable to reconstruct deep (Cambrian) molluscan evolution. Supposedly "rare" mitochondrial genome level features have long been promoted as phylogenetically informative. In our newly annotated data set, features such as genome size, transcription on one or both strands, and certain coupled pairs of PCGs show a homoplastic, but obviously non-random distribution. Apparently congruent (but not unambiguous) signal for non-trivial subclades, e.g. for a clade composed of pteriomorph and heterodont bivalves, needs confirmation from a more comprehensive bivalve sampling. We found that larger clusters not only of PCGs but also of rRNAs and even tRNAs can bear local phylogenetic signal; adding trnG-trnE to the end of the ancestral cluster trnM-trnC-trnY-trnW-trnQ might be synapomorphic for Mollusca. Mitochondrial gene arrangement and other genome level features explored and reviewed herein thus

  9. Delta-associated molluscan life and death assemblages in the northern Adriatic Sea: Implications for paleoecology, regional diversity and conservation.

    Science.gov (United States)

    Weber, Kristina; Zuschin, Martin

    2013-01-15

    Life-death (LD) studies of shelly macrofauna are important to evaluate how well a fossil assemblage can reflect the original living community, but can also serve as a proxy for recent ecological shifts in marine habitats and in practice this has to be distinguished using taphonomic preservation pattern and estimates of time-averaging. It remains to be rigorously evaluated, however, how to distinguish between sources of LD disagreement. In addition, death assemblages (DAs) also preserve important information on regional diversity which is not available from single censuses of the life assemblages (LAs). The northern Adriatic Sea is an ecosystem under anthropogenic pressure, and we studied the distribution and abundance of living and dead bivalve and gastropod species in the physically stressful environments (tidal flat and shallow sublittoral soft bottoms) associated with the delta of the Isonzo River (Gulf of Trieste). Specifically we evaluated the fidelity of richness, evenness, abundance, habitat discrimination and beta diversity. A total of 10,740 molluscs from fifteen tidal flat and fourteen sublittoral sites were analyzed for species composition and distribution of living and dead molluscs. Of 78 recorded species, only eleven were numerically abundant. There were many more dead than living individuals and rarefied species richness in the DA was higher at all spatial scales, but the differences are lower in habitats and in the region than at individual stations. Evenness was always higher in death assemblages, and probably due to temporally more variable LAs the differences are stronger in the sublittoral habitats. Distinct assemblages characterized intertidal and sublittoral habitats, and the distribution and abundance of empty shells generally corresponded to that of the living species. Death assemblages have lower beta diversity than life assemblages, but empty shells capture compositional differences between habitats to a higher degree than living shells

  10. A prospective, open, comparative study of 5% potassium hydroxide solution versus cryotherapy in the treatment of genital warts in men *

    OpenAIRE

    Camargo, Caio Lamunier de Abreu; Belda, Walter; Fagundes, Luiz Jorge; Romiti, Ricardo

    2014-01-01

    BACKGROUND: Genital warts are caused by human papillomavirus infection and represent one of the most common sexually transmitted diseases. Many infections are transient but the virus may recur, persist, or become latent. To date, there is no effective antiviral treatment to eliminate HPV infection and most therapies are aimed at the destruction of visible lesions. Potassium hydroxide is a strong alkali that has been shown to be safe and effective for the treatment of genital warts and mollusc...

  11. New records for the shallow-water chiton fauna (Mollusca, Polyplacophora of the Azores (NE Atlantic

    Directory of Open Access Journals (Sweden)

    Sérgio Ávila

    2013-06-01

    Full Text Available Published records, original data from recent field work on all of the islands of the Azores (NE Atlantic, and a revision of the entire mollusc collection deposited in the Department of Biology of the University of the Azores (DBUA were used to compile a checklist of the shallow-water Polyplacophora of the Azores. Lepidochitona cf. canariensis and Tonicella rubra are reported for the first time for this archipelago, increasing the recorded Azorean fauna to seven species.

  12. Regional differences in the lateral mobility of plasma membrane lipids in a molluscan embryo

    OpenAIRE

    Speksnijder, J.E.; Dohmen, M.R.; Tertoolen, L.G.J.; Laat, S.W. de

    1985-01-01

    Regional and temporal differences in plasma membrane lipid mobility have been analyzed during the first three cleavage cycles of the embryo of the polar-lobe-forming mollusc Nassarius reticulatus by the fluorescence photobleaching recovery (FPR) method, using 1,1′-ditetradecyl 3,3,3′,3′-tetramethylindocarbocyanine iodide (C14diI) as a fluorescent lipid probe. During this period of development the lateral diffusion coefficient of membrane lipids is consistently greater in the vegetal polar lob...

  13. Cephalopods as Predators: A Short Journey among Behavioral Flexibilities, Adaptions, and Feeding Habits

    OpenAIRE

    Villanueva, Roger; Perricone, Valentina; Fiorito, Graziano

    2017-01-01

    The diversity of cephalopod species and the differences in morphology and the habitats in which they live, illustrates the ability of this class of molluscs to adapt to all marine environments, demonstrating a wide spectrum of patterns to search, detect, select, capture, handle, and kill prey. Photo-, mechano-, and chemoreceptors provide tools for the acquisition of information about their potential preys. The use of vision to detect prey and high attack speed seem to be a predominant pattern...

  14. Facies and age of the Oso Ridge Member (new), Abo Formation, Zuni Mountains, New Mexico

    Science.gov (United States)

    Armstrong, A.K.; Stamm, R.G.; Kottlowski, F.E.; Mamet, B.L.; Dutro, J.T.; Weary, D.J.

    1994-01-01

    The Oso Ridge Member (new), at the base of the Abo Formation, nonconformably overlies Proterozoic rocks. The member consists of some 9m of conglomerate and arkose composed principally of fragments of the underlying Proterozoic metamorphic rocks; thin, fossiliferous limestone lenses are interbedded with the arkose. Biota from the lenses include a phylloid alga, foraminifers, conodonts, brachiopods, and molluscs. The age of the Oso Ridge Member is Virgilian Late Pennsylvanian) to Wolfcampian (Early Permian). -from Authors

  15. GENETIC DIVERSITY OF Vibrio harveyi ISOLATED FROM TIGER PRAWN Penaeus monodon HATCHERIES AND GROW OUT PONDS

    OpenAIRE

    Muliani Muliani; Ince Ayu Khairana Kadriah; Andi Parenrengi; Sulaeman Sulaeman

    2006-01-01

    ibrio harveyi is known as one among the most harmful bacteria infecting tiger prawn at every stage of its life’s. The present research was aimed to reveal the genetic diversity of Vibrio harveyi isolated from tiger prawn (Penaeus monodon) culture. The samples of bacteria were collected from hatchery (brood-stock, larvae, natural feed, artemia, and larval rearing water) and grow-out (juveniles, water, shrimp, sediment, plankton, crab, mollusc, microalgae, and wild fish).  The taxonomic identif...

  16. Impairing DNA methylation obstructs memory enhancement for at least 24?hours in Lymnaea

    OpenAIRE

    Rothwell, Cailin M.; Lukowiak, Ken D.

    2017-01-01

    ABSTRACT Stressor-induced memory enhancement has previously been shown to involve DNA methylation in the mollusc Lymnaea stagnalis. Specifically, injection of the DNA methylation inhibitor 5-AZA one hour before exposure to a memory-enhancing stressor obstructs memory augmentation. However, the duration of the influence of 5-AZA on this memory enhancement has not yet been examined. In this study, 2 memory-enhancing stressors (a thermal stress and exposure to the scent of a predator) were used ...

  17. Kinetic catalytic studies of scorpion's hemocyanin

    International Nuclear Information System (INIS)

    Queinnec, E.; Vuillaume, M.; Gardes-Albert, M.; Ferradini, C.; Ducancel, F.

    1991-01-01

    Hemocyanins are copper proteins which function as oxygen carriers in the haemolymph of Molluscs and Arthropods. They possess enzymatic properties: peroxidatic and catalatic activities, although they have neither iron nor porphyrin ring at the active site. The kinetics of the catalytic reaction is described. The reaction of superoxide anion with hemocyanin has been studied using pulse radiolysis at pH 9. The catalytic rate constant is 3.5 X 10 7 mol -1 .l.s -1 [fr

  18. Local phylogenetic divergence and global evolutionary convergence of skull function in reef fishes of the family Labridae

    OpenAIRE

    Westneat, Mark W; Alfaro, Michael E; Wainwright, Peter C; Bellwood, David R; Grubich, Justin R; Fessler, Jennifer L; Clements, Kendall D; Smith, Lydia L

    2005-01-01

    The Labridae is one of the most structurally and functionally diversified fish families on coral and rocky reefs around the world, providing a compelling system for examination of evolutionary patterns of functional change. Labrid fishes have evolved a diverse array of skull forms for feeding on prey ranging from molluscs, crustaceans, plankton, detritus, algae, coral and other fishes. The species richness and diversity of feeding ecology in the Labridae make this group a marine analogue to t...

  19. An early (1850) 'handwritten' shell exchange catalogue of the Leiden Museum, with notes on the collectors Rethaan Macaré and Tischbein

    OpenAIRE

    Bruggen, van, A.C.

    2013-01-01

    A ‘handwritten’ (lithographed) shell exchange catalogue of the National Museum of Natural History, Leiden (The Netherlands), dated 1850 and containing 864 nominal taxa (861 molluscs and 3 brachiopods), is discussed in the context of the history of the museum. This catalogue must have been distributed in a limited edition to shell collectors interested in the exchange of specimens. Among the exchange partners of the museum were the well-known 19th century Dutch collector Lady (later Dowager) F...

  20. Diversity of helminth parasites in aquatic invertebrate hosts in Latin America: how much do we know?

    Science.gov (United States)

    Aguirre-Macedo, M L; May-Tec, A L; Martínez-Aquino, A; Cremonte, F; Martorelli, S R

    2017-03-01

    Helminths in aquatic invertebrate hosts have been overlooked in comparison with vertebrate hosts. Therefore, the known diversity, ecology and distribution of these host-parasite systems are very limited in terms of their taxonomic diversity, habitat and geographic regions. In this study we examined the published literature on helminth parasites of aquatic invertebrates from Latin America and the Caribbean (LAC) to identify the state of the knowledge in the region and to identify patterns of helminth diversity. Results showed that 67% of the literature is from Argentina, Mexico and Brazil. We found records for 772 host-parasite associations. Most records relate to medically or economically important hosts. Molluscs were the most studied host group with 377 helminth records (80% trematodes). The lymnaeids and planorbids were the most studied molluscs across LAC. Arthropods were the second most studied host group with 78 helminth records (trematodes 38%, cestodes 24% and nematodes 20%), with shrimps and crabs being the most studied hosts. Host species with the largest number of helminth taxa were those with a larger sampling effort through time, usually in a small country region. No large geographical-scale studies were identified. In general, the knowledge is still too scarce to allow any zoogeographical or helminth diversity generalization, as most hosts have been studied locally and the studies on invertebrate hosts in LAC are substantially uneven among countries.

  1. Pearl aquaculture-profitable environmental remediation?

    Science.gov (United States)

    Gifford, S; Dunstan, R H; O'Connor, W; Roberts, T; Toia, R

    2004-02-05

    Bivalve molluscs are filter feeders, with pearl oysters able to filter water at rates up to 25 lh(-1)g(-1) of dry wt. tissue. Since this process leads to rapid bioaccumulation of recalcitrant pollutants such as heavy metals, organochlorine pesticides and hydrocarbons from impacted sites, it has prompted the widespread use of molluscs as biomonitors to quantify levels of marine pollution. This paper proposes pearl oyster deployment as a novel bioremediation technology for impacted sites to remove toxic contaminants, reduce nutrient loads and lower concentrations of microbial pathogens. Estimates extrapolated from the literature suggest that a modest pearl oyster farm of 100 t oyster material per year could remove 300 kg heavy metals plus 24 kg of organic contaminants via deposition into the tissue and shell. Furthermore, it was estimated that up to 19 kg of nitrogen may be removed from the coastal ecosystem per tonne of pearl oyster harvested. Pearl oysters are also likely to filter substantial amounts of sewage associated microbial pathogens from the water column. Method of cultivation and site selection are the key to minimising negative environmental impacts of bivalve cultivation. Deployment of oysters at sites with high nutrient and contaminant loadings would be advantageous, as these compounds would be removed from the ecosystem whilst generating a value-added product. Future potential may exist for harvesting bio-concentrated elements for commercial production.

  2. Mollusca from a species-rich deep-water Leptometra community in the Alboran Sea

    Directory of Open Access Journals (Sweden)

    Serge Gofas

    2014-12-01

    Full Text Available An exceptional species richness for Mollusca was found on Avempace bank (349-365 m, Djibouti group, Alboran Sea, where the most abundant species was the crinoid Leptometra phalangium. A sample of sediment sieved on a 0.5-mm mesh yielded 156 species of molluscs (83 live-taken, 1772 specimens with a high Shannon-Wiener diversity index (H’(log2=3.60. The dominant mollusc was Limopsis aurita and the six most common species accounted for 77% of the specimens. On the other hand, 42 species were represented by only one or two specimens. Two species are described as new, three more are first findings in the Mediterranean and two are first findings in Iberian waters. One-third of the species have not been reported from the neighbouring, well-explored Alboran Island platform. There is a considerable balance between the trophic groups, denoting a stable and structured community. Most of the species have an extensive Atlantic range, and most have a planktonic larval stage. Therefore, it can be hypothesized that the fauna benefits from a diverse influx of larvae carried in by the more superficial incoming Atlantic current. Because of its exceptional richness, this type of bathyal community with Leptometra and Limopsis should be considered a high priority for habitat conservation in the Mediterranean deep sea.

  3. Impairing DNA methylation obstructs memory enhancement for at least 24 hours in Lymnaea.

    Science.gov (United States)

    Rothwell, Cailin M; Lukowiak, Ken D

    2017-01-01

    Stressor-induced memory enhancement has previously been shown to involve DNA methylation in the mollusc Lymnaea stagnalis . Specifically, injection of the DNA methylation inhibitor 5-AZA one hour before exposure to a memory-enhancing stressor obstructs memory augmentation. However, the duration of the influence of 5-AZA on this memory enhancement has not yet been examined. In this study, 2 memory-enhancing stressors (a thermal stress and exposure to the scent of a predator) were used to examine whether injection of the DNA methylation inhibitor 5-AZA 24 hours before stress exposure would still impair memory enhancement. Indeed, it was observed that memory is still obstructed when 5-AZA is injected 24 hours before exposure to either of these stressors in Lymnaea . Understanding that 5-AZA still effectively impairs memory enhancement after a period of 24 hours is valuable because it indicates that experimental manipulations do not need to be made within one hour after the injection of this DNA methylation inhibitor and can instead be made within one day (i.e. 24 hours). These results will allow for a future examination of the possible involvement of DNA methylation in memory enhancement related to longer-term stressors or environmental changes. This study further elucidates the involvement of epigenetic changes in memory enhancement in Lymnaea , providing insight into the process of memory formation in this mollusc.

  4. Embryonic chirality and the evolution of spiralian left–right asymmetries

    Science.gov (United States)

    2016-01-01

    The group Spiralia includes species with one of the most significant cases of left–right asymmetries in animals: the coiling of the shell of gastropod molluscs (snails). In this animal group, an early event of embryonic chirality controlled by cytoskeleton dynamics and the subsequent differential activation of the genes nodal and Pitx determine the left–right axis of snails, and thus the direction of coiling of the shell. Despite progressive advances in our understanding of left–right axis specification in molluscs, little is known about left–right development in other spiralian taxa. Here, we identify and characterize the expression of nodal and Pitx orthologues in three different spiralian animals—the brachiopod Novocrania anomala, the annelid Owenia fusiformis and the nemertean Lineus ruber—and demonstrate embryonic chirality in the biradial-cleaving spiralian embryo of the bryozoan Membranipora membranacea. We show asymmetric expression of nodal and Pitx in the brachiopod and annelid, respectively, and symmetric expression of Pitx in the nemertean. Our findings indicate that early embryonic chirality is widespread and independent of the cleavage programme in the Spiralia. Additionally, our study illuminates the evolution of nodal and Pitx signalling by demonstrating embryonic asymmetric expression in lineages without obvious adult left–right asymmetries. This article is part of the themed issue ‘Provocative questions in left–right asymmetry’. PMID:27821523

  5. Radionuclide transfer to marine biota species: review of Russian language studies.

    Science.gov (United States)

    Fesenko, S; Fesenko, E; Titov, I; Karpenko, E; Sanzharova, N; Fonseca, A Gondin; Brown, J

    2010-11-01

    An extensive programme of experiments on transfer of radionuclides to aquatic species was conducted in the former USSR starting from the early 1950s. Only a few of these studies were made available in the English language literature or taken into account in international reviews of radionuclide behaviour in marine ecosystems. Therefore, an overview of original information on radionuclide transfer to marine biota species available from Russian language literature sources is presented here. The concentration ratio (CR) values for many radionuclides and for marine species such as: (239)Pu, (106)Ru and (95)Zr (crustacean), (54)Mn, (90)Sr, (95)Nb, (106)Ru, (137)Cs (239)Pu, (241)Am and natural U (molluscs), and (54)Mn, (90)Sr, (137)Cs and (144)Ce (fish) are in good agreement with those previously published, whilst for some of them, in particular, for (32)P and (110)Ag (crustaceans), (35)S (molluscs), (32)P, (35)S, (95)Nb, and (106)Ru (macroalgae) and (60)Co and (239,240)Pu (fish) the data presented here suggest that changes in the default CR reference values presented in recent marine reviews may be required. The data presented here are intended to supplement substantially the CR values being collated within the handbook on Wildlife Transfer Coefficients, coordinated under the IAEA EMRAS II programme.

  6. Metallothionein and glutathione in Lymnaea stagnalis determine the specificity of responses to the effects of ionising radiation

    International Nuclear Information System (INIS)

    Gnatyshyna, L.; Falfushynska, H.; Stoliar, O.; Bodilovska, O.; Oleynik, O.; Golubev, A.

    2012-01-01

    The aim of our study was to distinguish the stress-related molecular response of the pulmonate mollusc Lymnaea stagnalis from the Chernobyl area in comparison with the consequences of other harmful effects, including the short-term effects of radiation and heating. Specimens inhabiting ponds near the Chernobyl nuclear power plant, the cooling channel of the electric power station and the soil reclamation channel (groups R, T and C, correspondingly), and specimens adapted to laboratory conditions (a control group (CL), a disposable group exposed to 2 mGy X-ray radiation over the body (RL), and a group exposed to 25 deg. C for 4 days (TL)) were compared. Despite high variability of responses, Principle Component Analysis distinctly separated the laboratory and feral groups into two sets. In the feral groups, low levels of the stress-related and metal-binding protein metallothionein (MT), protein carbonyls and lactate dehydrogenase in the digestive gland were indicated. The main separating criteria selected by classification and regression tree analysis were the protein carbonyls, cholinesterase and MT. Molluscs from group R were clearly distinguished by the lowest levels of MT, Mn-superoxide dismutase and lactate dehydrogenase, and the highest level of glutathione, demonstrating that the oppression of the gene-determined stress-related response and its partially metabolic compensation can be possible markers for chronic environmental effects of irradiation. (authors)

  7. Lateral mobility of plasma membrane lipids in a molluscan egg: Evidence for an animal/vegetal polarity

    OpenAIRE

    Laat, S.W. de; Speksnijder, J.E.; Dohmen, M.R.; Zoelen, E. van; Tertoolen, L.G.J.; Bluemink, J.G.

    1984-01-01

    The lateral diffusion of the lipid analog C₁₄-diI (3', 3'-dihexadecylindocarbocyanine iodide) was measured in the plasma membrane of early embryos of the mollusc Nassarius reticulatus using the FPR-(Fluorescence Photobleaching Recovery) method. At almost all stages measured (from fertilized egg up to 8-cell stage) the diffusion coefficient (D) of the mobile fraction (MF) of C₁₄-diI is significantly higher in the plasma membrane of the polar lobe as compared to the plasma membrane of the anima...

  8. Acute and chronic exposure in mussel (aulacomya ater) and clam (semelle solida) with Cs137

    International Nuclear Information System (INIS)

    Bringas, J.E.

    1996-01-01

    Two of the most common Peruvian benthonic molluscs, have been shown to be effective concentrators of Cesium-137 and have also proven useful as indicators of that radionuclide in their natural environment, according with results in this paper. However the clam is a better indicator, when determining environmental acute release of Cesium-137 due to reactor accidents, nuclear tests, accidents in nuclear ships, submarines and radioactive material transport, and the mussel for a continuous monitoring of environmental radio contaminant levels. (author). 11 refs

  9. The AquaDEB project: Physiological flexibility of aquatic animals analysed with a generic dynamic energy budget model (phase II)

    OpenAIRE

    Alunno-bruscia, Marianne; Van Der Veer, Henk; Kooijman, S. A. L. M.

    2011-01-01

    This second special issue of the Journal of Sea Research on development and applications of Dynamic Energy Budget (DEB) theory concludes the European Research Project AquaDEB (2007–2011). In this introductory paper we summarise the progress made during the running time of this 5 years’ project, present context for the papers in this volume and discuss future directions. The main scientific objectives in AquaDEB were (i) to study and compare the sensitivity of aquatic species (mainly molluscs ...

  10. EFSA (European Food Safety Authority) and ECDC (European Centre for Disease Prevention and Control), 2015. The European Union summary report on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2014

    DEFF Research Database (Denmark)

    Helwigh, Birgitte; Porsbo, Lone Jannok; Boysen, Louise

    This report of the European Food Safety Authority and the European Centre for Disease Prevention and Control presents the results of the zoonoses monitoring activities carried out in 2014 in 32 European countries (28 Member States (MS) and four non-MS). Campylobacteriosis was the most commonly re......, molluscs and products thereof’. The report further summarises trends and sources along the food chain of tuberculosis due to Mycobacterium bovis, Brucella, Trichinella, Echinococcus, Toxoplasma, rabies, Coxiella burnetii (Q fever), West Nile virus and tularaemia....

  11. Some structures of marine natural products

    Energy Technology Data Exchange (ETDEWEB)

    Finer-Moore, J.S.

    1979-07-01

    Applications of x-ray crystallographic methods to marine chemistry are discussed. Results of research on a biosynthetic problem: diterpenes from Dictyotaceae are discussed under the following section headings: history of the problem; dictyoxepin; dictyodial; and dictyolactone. Studies on marine ecology are reported under the following headings: symbiosis and antibiosis; metabolites from opisthobranch molluscs, including, dolabelladiene, 9-isocyanopupukeanane and 2-isocyanopupukeanane, and crispatone; metabolites of goronians and soft corals, including zooxanthellae and the metabolism of coelenterates, ophirin, sinularene, and erectene. (JGB)

  12. Biological mineralization of iron: Studies using Moesbauer spectroscopy and complementary techniques

    International Nuclear Information System (INIS)

    Webb, J.; Kim, K.S.; Tran, K.C.; Pierre, T.G.S.

    1988-01-01

    Biological deposition of solid Fe-containing phases can be studied using 57 Fe Moessbauer spectroscopy. Other techniques are needed in order to understand this complex process. These include proton-induced X-ray and γ-ray emission (PIXE/PIGME), electron microscopy, electron and X-ray diffraction, infrared spectroscopy and chemical characterization of organic components. This paper reviews and evaluates the application of these techniques to biological mineralization of Fe, particularly that occurring in the radula teeth of the marine molluscs, chitons and limpets. (orig.)

  13. Testosterone-Fatty Acid esterification: a unique target for the endocrine toxicity of tributyltin to gastropods.

    Science.gov (United States)

    Leblanc, Gerald A; Gooding, Meredith P; Sternberg, Robin M

    2005-01-01

    Over the past thirty years, a global occurrence of sexual aberration has occurred whereby females among populations of prosobranch snails exhibit male sex characteristics. This condition, called imposex, has been causally associated with exposure to the biocide tributyltin. Tributyltin-exposed, imposex snails typically have elevated levels of testosterone which have led to the postulate that this endocrine dysfunction is responsible for imposex. This overview describes recent evidence that supports this postulate. Gastropods maintain circulating testosterone levels and administration of testosterone to females or castrates stimulates male sex differentiation in several snail species. Studies in the mud snail (Ilyanassa obsoleta) have shown that gastropods utilize a unique strategy for regulating free testosterone levels. Excess testosterone is converted to fatty acid esters by the action of a testosterone-inducible, high capacity/low affinity enzyme, acyl-CoA:testosterone acyl transferase, and stored within the organisms. Free testosterone levels are regulated during the reproductive cycle apparently due to changes in esterification/desterification suggesting that testosterone functions in the reproductive cycle of the organisms. Testosterone esterification provides a unique target in the testosterone regulatory machinery of snails that is altered by tributyltin. Indeed, imposex and free testosterone levels were elevated in field collected snails containing high tin levels, while testosterone-fatty acid ester pools were reduced in these organisms. These observations indicate that tributyltin elevates free testosterone by reducing the retention of testosterone as fatty acid-esters. This endocrine effect of tributyltin may be responsible for imposex.

  14. Ultrastructure of spermiogenesis in Vampyroteuthis infernalis Chun — a relict cephalopod mollusc

    Science.gov (United States)

    Healy, John M.

    1990-03-01

    Spermiogenesis in the relict deep-sea cephalopod Vampyroteuthis infernalis Chun is examined using transmission electron microscopy (TEM), and the results compared with available data on other cephalopods. Early spermatids of Vampyroteuthis exhibit an ovoid nucleus (with dense irregular patches), numerous mitochondria and a pair of triplet substructure centrioles (arranged parallel to each other). Subsequently, the following morphological changes take place: (1) nuclear contents condense into a fibrous reticulum, then into thick fibres; (2) the acrosomal vesicle (presumably Golgi-derived) positions itself in a shallow depression at the nuclear apex; (3) the flagellum forms from one of the two centrioles; (4) mitochondria cluster around the flagellum at the base of the nucleus; (5) a dense, fibrous plug forms within the basal invagination of the nucleus. Microtubules surround the acrosome and condensing nucleus of spermatids. The dense plug is of special systematic importance since it also occurs in spermatids and spermatozoa of Octopus spp., but not in any investigated species of the Sepiida, Sepiolida or Teuthida. Late spermatids and mature spermatozoa of Vampyroteuthis strongly resemble developing spermatids of Octopus, suggesting a close phylogenetic relationship between Vampyroteuthis (and the Vampyromorpha) and octopods.

  15. Biodepuration of polynuclear aromatic hydrocarbons from a bivalve mollusc, Mercenaria mercenaria L

    International Nuclear Information System (INIS)

    Tanacredl, J.T.; Cardenas, R.R.

    1991-01-01

    Mercenaria mercenaria, exposed in vitro for 48 h to nine parent polynuclear aromatic hydrocarbons (PAHs) found in waste crankcase oil (WCCO) and analyzed by multiparametric analysis over a 45-day depuration period in an activated carbon filtration aquaria system, did not depurate PAHs, but rather maintained them at detectable levels. Uptake of PAHs was shown to be directly related to clam weight. A cluster analysis of empirical results reaffirmed a biostabilization in PAH groupings in clam tissue over a 45-day depuration period and exhibited no evidence of a decreasing trend in total PAHs when subjected to ANOVA. Due to the commercial importance of hard-shell clams, the practices of clam depuration and clam relaying are reviewed in light of potential long-terms public health exposures to low-level xenobiotics and the implications for human consumers

  16. Macrobenthic molluscs from a marine - lagoonal environmental transition in Lesvos Island (Greece).

    Science.gov (United States)

    Evagelopoulos, Athanasios; Koutsoubas, Drosos; Gerovasileiou, Vasilis; Katsiaras, Nikolaos

    2016-01-01

    This paper describes an occurence dataset, also including numerical abundance and biomass data, pertaining to the macrobenthic molluscan assemblages from a marine - lagoonal environmental transition. The study system was the soft-substrate benthoscape of the area of the Kalloni solar saltworks (Lesvos Island, Greece). Specifically, the study area extended from the infralittoral zone of the inner Kalloni Gulf (marine habitat) to the bottoms of the first two evaporation ponds of the Kalloni solar saltworks (lagoonal habitat). Bottom sediment samples (3 replicates) were collected with a Van Veen grab sampler (0.1 m 2 ) at four sampling sites, along a 1.5 km long line transect that spanned the marine - lagoonal environmental transition. A total of four surveys were carried out seasonally in 2004.  A total of 39,345 molluscan individuals were sorted out of the sediment samples and were identified to 71 species, belonging to the Gastropoda (36), Bivalvia (34) and Scaphopoda (1) classes. Numerical abundance and wet biomass (with shells) data are included in the dataset. The dataset described in the present paper partially fills a significant gap in the scientific literature: Because ecological research of coastal lagoons has seldom explicitly considered the marine - lagoonal habitats interface, there are no openly accessible datasets pertaining to the particular structural component of the transitional waters benthoscapes of the Mediterranean Sea. Such datasets could prove valuable in the research of the structure and functioning of transitional waters benthoscapes. The present dataset is available as a supplementary file (Suppl. material 1) and can also be accessed at http://ipt.medobis.eu/resource?r=kalloni_saltworks_phd.

  17. Detection and quantification of Sapovirus in bivalve molluscs from Galicia (NW Spain.

    Directory of Open Access Journals (Sweden)

    Jesus L Romalde

    2014-06-01

    SaV was detected in 30 of the 168 samples (17,85%. There was no significant difference between the two Rías in terms of detections, although it was observed a seasonality increment of positive samples from November 2011 until April 2012 in both Rías due to the rainy season and the decrease of seawater temperature. Total quantification ranged between 103 and 105 copies of viral RNA/g of digestive tissue (c/g, being mussels the specie with lower main quantification (3,1 x 104 c/g and clams the species with higher medium rates (2,0 x 105 c/g. This represents the first study out of Japan in which human Sapovirus was detected and quantified into human food intended for consumption.

  18. Is oxidative stress related to cadmium accumulation in the Mollusc Crassostrea angulata?

    Energy Technology Data Exchange (ETDEWEB)

    Macías-Mayorga, Dayanara, E-mail: dayanara.macias@uleam.edu.ec [Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz (Spain); Departamento Central De Investigación (DCI), Universidad Laica Eloy Alfaro de Manabí, Vía San Mateo, Manta (Ecuador); Laiz, Irene [Departamento de Física Aplicada, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz (Spain); Moreno-Garrido, Ignacio; Blasco, Julián [Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz (Spain)

    2015-04-15

    Highlights: • The cadmium accumulation in C. angulata tended toward a stationary state. • Metallothionein-like protein (MTLP) is clearly induced by Cd accumulation. • The MTLP detoxification mechanism is affected at high Cd concentrations. • Cadmium toxicity causes GSH levels to decrease and inhibits antioxidant enzymes. - Abstract: The kinetics of cadmium (Cd) accumulation in the gills and digestive gland of Crassotrea angulata at three concentrations of cadmium (0.088 μM, 0.44 μM and 2.22 μM) was monitored for 28 days. The relationship between accumulation and toxicity was studied using metallothionein-like protein (MTLP) concentration and reduced glutathione levels (GSH) as biochemical endpoints. The activity of enzymes which form part of the antioxidant defense system, in particular glutathione reductase (GR), total glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT), as enzymatic endpoints, was also assessed. A first order kinetic model demonstrated that the accumulation process does not take place linearly, as the Cd concentration in gills and digestive gland tended toward a stationary state. Metallothionein-like protein is clearly induced by Cd accumulation; however, at high Cd concentrations the detoxification mechanism of this protein is affected. High Cd concentrations (2.22 μM) lead to a decrease in GSH levels, and also inhibit antioxidant enzyme activities, demonstrating the adverse effect of this metal on the antioxidant balance system.

  19. Is oxidative stress related to cadmium accumulation in the Mollusc Crassostrea angulata?

    Science.gov (United States)

    Macías-Mayorga, Dayanara; Laiz, Irene; Moreno-Garrido, Ignacio; Blasco, Julián

    2015-04-01

    The kinetics of cadmium (Cd) accumulation in the gills and digestive gland of Crassotrea angulata at three concentrations of cadmium (0.088 μM, 0.44 μM and 2.22 μM) was monitored for 28 days. The relationship between accumulation and toxicity was studied using metallothionein-like protein (MTLP) concentration and reduced glutathione levels (GSH) as biochemical endpoints. The activity of enzymes which form part of the antioxidant defense system, in particular glutathione reductase (GR), total glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT), as enzymatic endpoints, was also assessed. A first order kinetic model demonstrated that the accumulation process does not take place linearly, as the Cd concentration in gills and digestive gland tended toward a stationary state. Metallothionein-like protein is clearly induced by Cd accumulation; however, at high Cd concentrations the detoxification mechanism of this protein is affected. High Cd concentrations (2.22 μM) lead to a decrease in GSH levels, and also inhibit antioxidant enzyme activities, demonstrating the adverse effect of this metal on the antioxidant balance system. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Is oxidative stress related to cadmium accumulation in the Mollusc Crassostrea angulata?

    International Nuclear Information System (INIS)

    Macías-Mayorga, Dayanara; Laiz, Irene; Moreno-Garrido, Ignacio; Blasco, Julián

    2015-01-01

    Highlights: • The cadmium accumulation in C. angulata tended toward a stationary state. • Metallothionein-like protein (MTLP) is clearly induced by Cd accumulation. • The MTLP detoxification mechanism is affected at high Cd concentrations. • Cadmium toxicity causes GSH levels to decrease and inhibits antioxidant enzymes. - Abstract: The kinetics of cadmium (Cd) accumulation in the gills and digestive gland of Crassotrea angulata at three concentrations of cadmium (0.088 μM, 0.44 μM and 2.22 μM) was monitored for 28 days. The relationship between accumulation and toxicity was studied using metallothionein-like protein (MTLP) concentration and reduced glutathione levels (GSH) as biochemical endpoints. The activity of enzymes which form part of the antioxidant defense system, in particular glutathione reductase (GR), total glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT), as enzymatic endpoints, was also assessed. A first order kinetic model demonstrated that the accumulation process does not take place linearly, as the Cd concentration in gills and digestive gland tended toward a stationary state. Metallothionein-like protein is clearly induced by Cd accumulation; however, at high Cd concentrations the detoxification mechanism of this protein is affected. High Cd concentrations (2.22 μM) lead to a decrease in GSH levels, and also inhibit antioxidant enzyme activities, demonstrating the adverse effect of this metal on the antioxidant balance system

  1. TBT pollution and effects in molluscs at US Virgin Islands, Caribbean Sea

    DEFF Research Database (Denmark)

    Strand, Jakob; Jørgensen, Anne; Tairova, Zhanna

    2009-01-01

    Thais deltoidea, Thais rustica and Purpura patula all seem to have potential as suitable and sensitive bioindicators for assessing levels and effects of TBT pollution in coastal areas including coral reefs in the Caribbean Sea. However, considerable interspecies differences in especially accumulation...

  2. Detection of Taurine in Biological Tissues by 33S NMR Spectroscopy

    Science.gov (United States)

    Musio, Roberta; Sciacovelli, Oronzo

    2001-12-01

    The potential of 33S NMR spectroscopy for biochemical investigations on taurine (2-aminoethanesulfonic acid) is explored. It is demonstrated that 33S NMR spectroscopy allows the selective and unequivocal identification of taurine in biological samples. 33S NMR spectra of homogenated and intact tissues are reported for the first time, together with the spectrum of a living mollusc. Emphasis is placed on the importance of choosing appropriate signal processing methods to improve the quality of the 33S NMR spectra of biological tissues.

  3. الأسالیب المعماریة لتغطیة المحاریب فی العمارة الأندلسیة "دراسة أثریة معماریة مقارنة مع المغرب الأقصى"

    Directory of Open Access Journals (Sweden)

    prof . Ahmed dokmak

    2016-01-01

    Full Text Available This research vestigates a new comparative architectural study about Andalusian – Moroccan mihrabs , similarities and differences through the remaining mihrabs from Umayyad era , kings of communities , Morabitin , Amohads , Beni Nasr , Al-Marenin ,Al-Saadin as well as showing the diversity in covering methods such as molluscous , lobed domes , stlactites domes , half lobed domes , octal , smooth , in addition to a study of architectural elements as their plan, arches, transition areas, types of domes , and comparing them with contemporary ones in Andalus and Morocco .

  4. Actividad molusquicida del Paraiso (Melia azedarach L. (Meliaceae sobre Lymnaea cubensis, molusco vector de Fasciolosis Molluscicidal activity of Paraiso (Melia azedarach L. (Meliaceae on Lymnaea cubensis, host snail of Fasciolosis

    Directory of Open Access Journals (Sweden)

    Marlene Piña Perez

    1998-06-01

    ções do suco extraído do fruto e semente do Paraiso (Melia azedarach L. foram testadas para determinar as doses médias letais (DL50 e máxima (DL90 usando um programa computadorizado PROBIT-LOG. Sete séries experimentais foram realizadas , usando 72 moluscos em cada uma. Para determinar a influência sobre a freqûência cardíaca foram testados três grupos de 10 moluscos, dois foram tratados com as CL50= 0,88627 e CL90= 1,7641, respectivamente, enquanto que o terceiro foi considerado como controle. RESULTADOS E CONCLUSÕES: Observou-se uma marcada influência de ambas as doses sobre a freqüência cardíaca do molusco estudado. Os resultados foram alentadores, pois demonstraram um potencial uso dessa planta no controle de moluscos não desejados.INTRODUCTION: Fasciolosis is a source of serious economic loss in various regions of Brazil and when control measures of its host (molluscs are not taken under favorable ecological conditions, isolated cases of human Fasciolosis may occur. Among the alternative measures for its control is the use of vegetable extracts and the purpose of this project is the assessment of the use of juice extracted from the fruit and seeds of the Paraiso plant (Melia azedarach L. in the control of Lymnaea cubensis, the main vector of Fasciolosis in Cuba. MATERIAL AND METHOD: Various concentrations of the juice extracted from the Paraiso fruit (Melia azedarach L. were tested to determine the average and maximum lethal doses (DL50 and DL90, respectively used in a computerized PROBIT-LOG program. Seven experimental series were undertaken, 72 molluscs being used in each of them. Three groups of ten molluscs were tested to determine the effect on cardiac frequency, two of them being treated with CL50=0.88627 and CL90=1.7641, respectively, the third being used as control. RESULTS AND CONCLUSIONS: A considerable effect of both doses on the cardiac frequency of the mollusc studied was observed. The results were encouraging, for they demonstrated the

  5. Malacología Latinoamericana: Moluscos de agua dulce de Argentina

    Directory of Open Access Journals (Sweden)

    Alejandra Rumi

    2008-03-01

    Full Text Available Se presenta un estado de situación y una lista actualizada y comentada sobre las especies de moluscos de agua dulce de la República Argentina. Se aborda en Gastropoda y Bivalvia la distribución a nivel de familias; las entidades endémicas, exóticas, invasoras y de importancia sanitaria. Los moluscos relacionados a la cuenca del Plata presentan la mayor riqueza específica. Base de datos: 4 500 registros relevados de las tres colecciones más importantes de la Argentina: MLP, MACN y FML. Además, se incluye información de recolecciones actuales y localidades citadas por otros autores. Hasta el presente han sido descritas 166 especies. De ellas 101 pertenecen a 10 familias de Gastropoda y 65 a 7 de Bivalvia. Las familias que presentan mayor riqueza específica son Lithoglyphidae (22 y Sphaeriidae (25, respectivamente. Sphaeriidae, Cochliopidae, Chilinidae y Lymnaeidae se distribuyen prácticamente en todo el país. Erodonidae y Solecurtidae se registran en ambientes mixohalinos de la provincia de Buenos Aires. Thiaridae y Glacidorbiidae presentan una distribución muy restringida. Especies endémicas de la Argentina: Gastropoda: Ampullariidae (1, Cochliopidae (10, Lithoglyphidae (11, Thiariidae (3, Chilinidae (11, Lymnaeidae (2 y Physidae (2?; Bivalvia: Hyriidae (1?; Etheriidae (1? y Sphaeriidae (10. Especies de interés sanitario: propagadoras de: Esquistosomiasis, Biomphalaria peregrina, B. straminea y B. tenagophila (Planorbidae; Fasciolasis, Lymnaea viatrix y L. columnella (Lymnaeidae; y dermatitis esquistosómicas, Chilina gibbosa y C. fluminea (Chilinidae. Especies de origen asiático: Corbicula fluminea (Corbiculidae y Limnoperna fortunei (Mytilidae. Es prioritaria la formación de áreas protegidas para la conservación de especies endémicas, especialmente de la Mesopotamia Argentina.Latin American Malacology. Freshwater Mollusks from Argentina. A report and an updated list with comments on the species of freshwater molluscs of

  6. A model explaining synchronization of neuron bioelectric frequency under weak alternating low frequency magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Moral, A. del, E-mail: delmoral@unizar.es [Laboratorio de Magnetismo, Departamento de Física de Materia Condensada and Instituto de Ciencia de Materiales, Universidad de Zaragoza and Consejo Superior de Investigaciones Científicas, 50009 Zaragoza (Spain); Laboratorio de Magnetobiología, Departamento de Anatomía e Histología, Facultad de Medicina, Universidad de Zaragoza, 50009 Zaragoza (Spain); Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, 28223 Madrid (Spain); Azanza, María J., E-mail: mjazanza@unizar.es [Laboratorio de Magnetobiología, Departamento de Anatomía e Histología, Facultad de Medicina, Universidad de Zaragoza, 50009 Zaragoza (Spain); Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, 28223 Madrid (Spain)

    2015-03-01

    A biomagnetic-electrical model is presented that explains rather well the experimentally observed synchronization of the bioelectric potential firing rate (“frequency”), f, of single unit neurons of Helix aspersa mollusc under the application of extremely low frequency (ELF) weak alternating (AC) magnetic fields (MF). The proposed model incorporates to our widely experimentally tested model of superdiamagnetism (SD) and Ca{sup 2+} Coulomb explosion (CE) from lipid (LP) bilayer membrane (SD–CE model), the electrical quadrupolar long range interaction between the bilayer LP membranes of synchronized neuron pairs, not considered before. The quadrupolar interaction is capable of explaining well the observed synchronization. Actual extension of our SD–CE-model shows that the neuron firing frequency field, B, dependence becomes not modified, but the bioelectric frequency is decreased and its spontaneous temperature, T, dependence is modified. A comparison of the model with synchronization experimental results of pair of neurons under weak (B{sub 0}≅0.2–15 mT) AC-MF of frequency f{sub M}=50 Hz is reported. From the deduced size of synchronized LP clusters under B, is suggested the formation of small neuron networks via the membrane lipid correlation. - Highlights: • Neuron pair synchronization under low frequency alternating (AC) magnetic field (MF). • Superdiamagnetism and Ca{sup 2+} Coulomb explosion for AC MF effect in synchronized frequency. • Membrane lipid electrical quadrupolar pair interaction as synchronization mechamism. • Good agreement of model with electrophysiological experiments on mollusc Helix neurons.

  7. NeuronBank: a tool for cataloging neuronal circuitry

    Directory of Open Access Journals (Sweden)

    Paul S Katz

    2010-04-01

    Full Text Available The basic unit of any nervous system is the neuron. Therefore, understanding the operation of nervous systems ultimately requires an inventory of their constituent neurons and synaptic connectivity, which form neural circuits. The presence of uniquely identifiable neurons or classes of neurons in many invertebrates has facilitated the construction of cellular-level connectivity diagrams that can be generalized across individuals within a species. Homologous neurons can also be recognized across species. Here we describe NeuronBank.org, a web-based tool that we are developing for cataloging, searching, and analyzing neuronal circuitry within and across species. Information from a single species is represented in an individual branch of NeuronBank. Users can search within a branch or perform queries across branches to look for similarities in neuronal circuits across species. The branches allow for an extensible ontology so that additional characteristics can be added as knowledge grows. Each entry in NeuronBank generates a unique accession ID, allowing it to be easily cited. There is also an automatic link to a Wiki page allowing an encyclopedic explanation of the entry. All of the 44 previously published neurons plus one previously unpublished neuron from the mollusc, Tritonia diomedea, have been entered into a branch of NeuronBank as have 4 previously published neurons from the mollusc, Melibe leonina. The ability to organize information about neuronal circuits will make this information more accessible, ultimately aiding research on these important models.

  8. Reproductive toxicity of bisphenol A and cadmium in Potamopyrgus antipodarum and modulation of bisphenol A effects by different test temperature

    International Nuclear Information System (INIS)

    Sieratowicz, Agnes; Stange, Daniela; Schulte-Oehlmann, Ulrike; Oehlmann, Joerg

    2011-01-01

    An OECD initiative for the development of mollusc-based toxicity tests for endocrine disrupters and other chemicals has recommended three test species with respective test designs for further standardisation. Preparing a subsequent pre-validation study we performed a reproduction test with Potamopyrgus antipodarum, determining the concentration range of the selected test substances, bisphenol A (BPA) and cadmium (Cd). At 16 deg. C, the recommended test temperature, the number of embryos in the brood pouch was increased by BPA and decreased by Cd (NOEC: 20 μg BPA/L and 1 μg Cd/L). Coinstantaneous BPA tests at 7 deg. C and 25 deg. C demonstrated a temperature dependency of the response, resulting in lower NOECs (5 μg/L respectively). As expected, reproduction in control groups significantly varied depending on temperature. Additional observations of the brood stock showed seasonal fluctuations in reproduction under constant laboratory conditions. The recommended temperature range and test conditions have to be further investigated. - Highlights: → We performed a reproduction test with the mollusc Potamopyrgus antipodarum. → We defined the test substance concentration range for a pre-validation study. → The bisphenol A effect (increased reproduction) depends on the test temperature. → Reproduction of control groups significantly varies depending on temperature. → The brood stock shows seasonal fluctuations in reproduction at constant conditions. - A reproduction test with Potamopyrgus antipodarum with 2 substances for subsequent pre-validation is presented and bisphenol A effects show a temperature dependency.

  9. Tropomyosin or not tropomyosin, what is the relevant allergen in house dust mite and snail cross allergies?

    Science.gov (United States)

    Bessot, J C; Metz-Favre, C; Rame, J M; De Blay, F; Pauli, G

    2010-02-01

    Since tropomyosin is cross reactive in many arthropods, it was assumed that this highly conserved protein could be responsible for cross reactions in house dust mite (HDM) allergic patients who experienced adverse reactions after crustacean and mollusc ingestion. Here we report two clinical cases where the role of tropomyosin is a matter of debate. In the first case, the clinical history, as well as the results of in vivo and in vitro investigations, are in favour of a shrimp allergy without any snail allergy in a patient sensitized to HDM. In the second, the clinical history and the cutaneous tests are in favour of an allergy to snails without any allergy to shrimps in a patient suffering from HDM allergies. The clinical presentation is different in shrimp and snail allergies. In shrimp allergy, symptoms are mainly urticaria or angio-oedema. In snail allergies, adverse reactions are especially severe asthma. Shrimp tropomyosin is a dominant allergen in crustaceans whereas has a much less prominent role in HDM sensitization. Cross reactivities between HDM and snails have been confirmed by inhibition experiments. However, tropomyosin appears to be a minor allergen or even is not involved in snail allergy. It is necessary to clarify the allergens shared between HDMI and snails. The effects of HDM immunotherapy in snail allergy are questioned. Knowledge of taxonomy can contribute to more precise evaluation of cross reactivities between crustaceans and molluscs.

  10. Mixed effects of elevated pCO2 on fertilisation, larval and juvenile development and adult responses in the mobile subtidal scallop Mimachlamys asperrima (Lamarck, 1819.

    Directory of Open Access Journals (Sweden)

    Elliot Scanes

    Full Text Available Ocean acidification is predicted to have severe consequences for calcifying marine organisms especially molluscs. Recent studies, however, have found that molluscs in marine environments with naturally elevated or fluctuating CO2 or with an active, high metabolic rate lifestyle may have a capacity to acclimate and be resilient to exposures of elevated environmental pCO2. The aim of this study was to determine the effects of near future concentrations of elevated pCO2 on the larval and adult stages of the mobile doughboy scallop, Mimachlamys asperrima from a subtidal and stable physio-chemical environment. It was found that fertilisation and the shell length of early larval stages of M. asperrima decreased as pCO2 increased, however, there were less pronounced effects of elevated pCO2 on the shell length of later larval stages, with high pCO2 enhancing growth in some instances. Byssal attachment and condition index of adult M. asperrima decreased with elevated pCO2, while in contrast there was no effect on standard metabolic rate or pHe. The responses of larval and adult M. asperrima to elevated pCO2 measured in this study were more moderate than responses previously reported for intertidal oysters and mussels. Even this more moderate set of responses are still likely to reduce the abundance of M. asperrima and potentially other scallop species in the world's oceans at predicted future pCO2 levels.

  11. Middle and late Badenian palaeoenvironments in the northern Vienna Basin and their potential link to the Badenian Salinity Crisis

    Science.gov (United States)

    Harzhauser, Mathias; Grunert, Patrick; Mandic, Oleg; Lukeneder, Petra; Gallardo, Ángela García; Neubauer, Thomas A.; Carnevale, Giorgio; Landau, Bernard M.; Sauer, Roman; Strauss, Philipp

    2018-04-01

    Hydrocarbon exploration in the Bernhardsthal and Bernhardsthal-Sued oil fields documents an up to 2000 m thick succession of middle and upper Badenian deposits in this part of the northern Vienna Basin (Austria). Based on palaeontological analyses of core-samples, well-log data and seismic surveys we propose an integrated stratigraphy and describe the depositional environments. As the middle/late Badenian boundary is correlated with the Langhian/Serravallian boundary, the cores capture the crucial phase of the Middle Miocene Climate Transition. The middle Badenian starts with a major transgression leading to outer neritic to upper bathyal conditions in the northern Vienna Basin, indicated by Bathysiphon-assemblages and glass-sponges. A strong palaeo-relief and rapid synsedimentary subsidence accentuated sedimentation during this phase. The middle/late Badenian boundary coincides with a major drop of relative sea level by about 200 m, resulting in a rapid shift from deeper marine depositional environments to coastal and freshwater swamps. In coeval marine settings, a more than 100 m thick unit of anhydrite-bearing clay formed. This is the first evidence of evaporite precipitation during the Badenian Salinity Crisis in the Vienna Basin. Shallow lagoonal environments with diverse and fully marine mollusc and fish assemblages were established during the subsequent late Badenian re-flooding. In composition, the mollusc fauna differs considerably from older ones and is characterized by the sudden appearance of species with eastern Paratethyan affinities.

  12. Study of the toxic effects of flame retardant PBDE-47 on the clam Chamelea gallina (Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    Salvatora Angela Angioni

    2013-03-01

    Full Text Available The purpose of the study is to evaluate the effects of 2,2',4,4'-tetrabromodiphenylether (PBDE-47 on the Chamelea gallina clam (according to current commercial regulations: Venus gallina. PBDEs, which are used as flame retardants in various industrial products, are classed as hazardous substances by Directive 2011/65/EU. They are bioaccumulative compounds, considered to be endocrine disruptors, genotoxic, neurotoxic and practically ubiquitous, and their concentration in the environment has considerably increased in recent years. The aim of this study is to establish the effects of PBDE-47 on Chamelea gallina: toxic power and any harmful effects on the gonads, bioaccumulation capacity in the tissues, and possible entry into the food chain. The research used 96-hour and 21-day experimental tests on clams housed in filtered seawater. The tests were preceded by a period of acclimatisation of the molluscs lasting five to seven days. The clams were fed on seaweed (Dunaliella tertiolecta. The choice of the toxic compound PBDE-47 was based on the high concentration, among the congeners of PBDE, found in some aquatic species. The study demonstrated that the concentration of the contaminant used did not alter the vital functions, cause significant levels of mortality or lead to evident alteration in the gonads of Chamelea gallina. However, the research demonstrated the bioaccumulation capacity of the bivalve mollusc, allowing PBDE-47 to enter the food chain.

  13. Phylogenetic patterns and phenotypic plasticity of molluscan sexual systems.

    Science.gov (United States)

    Collin, Rachel

    2013-10-01

    Molluscs show a wide diversity of sexual systems and strategies. There are both gastropod and bivalve families that are each primarily dioecious, simultaneous hermaphrodites, or sequential hermaphrodites, and other families in which almost every sexual strategy occurs. The multiple evolutionary transitions of sexual systems within molluscs would allow comparative analyses of the associated ecological factors, but data on all but a few groups are too sparse to draw many solid conclusions. The phylogenetic distribution of sexual systems in the Mollusca shows that gastropods and bivalves demonstrate different patterns, possibly associated with the presence/absence of copulation. The distribution of change of sex suggests that, in gastropods, sequential hermaphrodites do not evolve from simultaneous hermaphrodites, and that sex reversal (flip-flopping) occurs in free-spawners but not in copulators. Three well-studied protandrous gastropod groups (calyptraeids, coralliophilids, and patellogastropods) show similar responses to environmental conditions and associations with conspecifics. They all have the following attributes: (1) they are sedentary, (2) they live in groups, patches, or aggregates, and (3) size at sex change varies among sites and among aggregates. In addition the available experimental evidence suggests that (4) the presence of females or large individuals represses growth and sex change of males, and (5) behavior seems to mediate the repressive influence of large females. Available data from other species tend to support these patterns. Finally, the repression of growth of males by females in protandry likely facilitates the evolution of dwarf males.

  14. Malakofauna pohoria Bachureň (východné Slovensko Malacofauna of the Bachureň Mts. (Eastern Slovakia

    Directory of Open Access Journals (Sweden)

    Jozef Šteffek

    2013-01-01

    Full Text Available The Bachureň Mts. are the least known orographic unit of Slovakia from the malacological point of view, therefore it was important to fill this gap in the faunistic research of malacofauna in Slovakia. In order to achieve the maximum mollusc diversity of the Bachureň Mts., various habitat types were the subject of interest. Field work was conducted in the years 2009–2011 at 78 sites. Altogether 108 mollusc species were recorded. In total, nearly 20 000 specimens were collected and identified. Half of all recorded species were representatives of woodland species s. l. From zoogeographical point of view, species with cosmopolitan, Euro-Siberian and Central European distribution made up the highest proportion. Carpathian species were numerous as well. Across the whole mountain, West Carpathian species (Petasina unidentata, Plicuteria lubomirskii and Trochulus villosulus encountered the species with centre in eastern part of the Carpathians (Perforatella dibothrion, Pseudalinda stabilis, Oxychilus orientalis and Vestia gulo. On the basis of spatial distribution of sensitive species indicating undisturbance of habitats, the most valuable biotopes showed to be springs, wetlands and riparian vegetation along the upper parts of the streams with Acicula parcelineata, Bulgarica cana, Macrogastra latestriata, Vertigo angustior, V. antivertigo, V. substriata, and Cochlicopa nitens. Valuable biotopes were dolomite rocks with the occurrence of relict steppe with Pupilla triplicata and well-preserved scree woodlands with V. substriata and B. cana as well.

  15. A model explaining synchronization of neuron bioelectric frequency under weak alternating low frequency magnetic field

    International Nuclear Information System (INIS)

    Moral, A. del; Azanza, María J.

    2015-01-01

    A biomagnetic-electrical model is presented that explains rather well the experimentally observed synchronization of the bioelectric potential firing rate (“frequency”), f, of single unit neurons of Helix aspersa mollusc under the application of extremely low frequency (ELF) weak alternating (AC) magnetic fields (MF). The proposed model incorporates to our widely experimentally tested model of superdiamagnetism (SD) and Ca 2+ Coulomb explosion (CE) from lipid (LP) bilayer membrane (SD–CE model), the electrical quadrupolar long range interaction between the bilayer LP membranes of synchronized neuron pairs, not considered before. The quadrupolar interaction is capable of explaining well the observed synchronization. Actual extension of our SD–CE-model shows that the neuron firing frequency field, B, dependence becomes not modified, but the bioelectric frequency is decreased and its spontaneous temperature, T, dependence is modified. A comparison of the model with synchronization experimental results of pair of neurons under weak (B 0 ≅0.2–15 mT) AC-MF of frequency f M =50 Hz is reported. From the deduced size of synchronized LP clusters under B, is suggested the formation of small neuron networks via the membrane lipid correlation. - Highlights: • Neuron pair synchronization under low frequency alternating (AC) magnetic field (MF). • Superdiamagnetism and Ca 2+ Coulomb explosion for AC MF effect in synchronized frequency. • Membrane lipid electrical quadrupolar pair interaction as synchronization mechamism. • Good agreement of model with electrophysiological experiments on mollusc Helix neurons

  16. Ross Sea Mollusca from the Latitudinal Gradient Program: R/V Italica 2004 Rauschert dredge samples

    Directory of Open Access Journals (Sweden)

    Claudio Ghiglione

    2013-10-01

    Full Text Available Information regarding the molluscs in this dataset is based on the Rauschert dredge samples collected during the Latitudinal Gradient Program (LGP on board the R/V “Italica” in the Ross Sea (Antarctica in the austral summer 2004. A total of 18 epibenthic dredge deployments/samplings have been performed at four different locations at depths ranging from 84 to 515m by using a Rauschert dredge with a mesh size of 500µm. In total 8,359 specimens have been collected belonging to a total of 161 species. Considering this dataset in terms of occurrences, it corresponds to 505 discrete distributional records (incidence data. Of these, in order of abundance, 5,965 specimens were Gastropoda (accounting for 113 species, 1,323 were Bivalvia (accounting for 36 species, 949 were Aplacophora (accounting for 7 species, 74 specimens were Scaphopoda (3 species, 38 were Monoplacophora (1 species and, finally, 10 specimens were Polyplacophora (1 species. This data set represents the first large-scale survey of benthic micro-molluscs for the area and provides important information about the distribution of several species, which have been seldom or never recorded before in the Ross Sea. All vouchers are permanently stored at the Italian National Antarctic Museum (MNA, Section of Genoa, enabling future comparison and crosschecking. This material is also currently under study, from a molecular point of view, by the barcoding project “BAMBi” (PNRA 2010/A1.10.

  17. Co-Option and De Novo Gene Evolution Underlie Molluscan Shell Diversity

    Science.gov (United States)

    Aguilera, Felipe; McDougall, Carmel

    2017-01-01

    Abstract Molluscs fabricate shells of incredible diversity and complexity by localized secretions from the dorsal epithelium of the mantle. Although distantly related molluscs express remarkably different secreted gene products, it remains unclear if the evolution of shell structure and pattern is underpinned by the differential co-option of conserved genes or the integration of lineage-specific genes into the mantle regulatory program. To address this, we compare the mantle transcriptomes of 11 bivalves and gastropods of varying relatedness. We find that each species, including four Pinctada (pearl oyster) species that diverged within the last 20 Ma, expresses a unique mantle secretome. Lineage- or species-specific genes comprise a large proportion of each species’ mantle secretome. A majority of these secreted proteins have unique domain architectures that include repetitive, low complexity domains (RLCDs), which evolve rapidly, and have a proclivity to expand, contract and rearrange in the genome. There are also a large number of secretome genes expressed in the mantle that arose before the origin of gastropods and bivalves. Each species expresses a unique set of these more ancient genes consistent with their independent co-option into these mantle gene regulatory networks. From this analysis, we infer lineage-specific secretomes underlie shell diversity, and include both rapidly evolving RLCD-containing proteins, and the continual recruitment and loss of both ancient and recently evolved genes into the periphery of the regulatory network controlling gene expression in the mantle epithelium. PMID:28053006

  18. NMDA receptor expression and C terminus structure in the rotifer Brachionus plicatilis and long-term potentiation across the Metazoa.

    Science.gov (United States)

    Kenny, Nathan J; Dearden, Peter K

    2013-12-01

    The C termini of N-methyl-D-aspartate (NMDA) receptor NR2 subunits are thought to play a major role in the molecular establishment of memory across the Bilateria, via the phenomenon known as long-term potentiation (LTP). Despite their long history of use as models in the study of memory, the expression and structure of the NR2 subunit in the Lophotrochozoa has remained uncategorized. Here, we report the phylogenic relationships of NR subunits across the Bilateria, and the cloning and in situ analysis of expression of NMDA NR1 and NR2 subunits in the monogont rotifer Brachionus plicatilis. RNA in situ hybridization suggests expression of NMDA receptor subunits in B. plicatilis is neural, consistent with expression observed in other species, and ours is the first report confirming NR2 expression in the lophotrochozoan clade. However, the single NR2 subunit identified in B. plicatilis was found to lack the long C terminal domain found in vertebrates, which is believed to modulate LTP. Further investigation revealed that mollusc and annelid NR2 subunits possess long intracellular C terminal domains. As data from molluscs (and particularly Aplysia californica) are the basis for much of our understanding of LTP, understanding how these diverse lophotrochozoan C termini function in vivo will have many implications for how we consider the evolution of the molecular control of learning and memory across the Metazoa as a whole and interpret the results of experiments into this vital component of cognition.

  19. Update of alien fauna and new records from Tunisian marine waters

    Directory of Open Access Journals (Sweden)

    K. OUNIFI- BEN AMOR

    2015-01-01

    Full Text Available An updated inventory of alien marine fauna in coastal and offshore Tunisian waters is presented. Records were compiled from scientific and ‘grey’ publications, presentations at scientific meetings, theses presented in fulfillment of requirements towards MSc and PhD degrees, websites and personal observations. 136 alien species were recorded in Tunisian waters, 60 records in northern coasts, West Mediterranean and 76 in central and southern coasts, Central Mediterranean. Nearly half of the first sightings in Tunisian waters took place in the Gulf of Gabès. The dominant taxa are Crustancean (24%, Molluscs (23%, Fishes (19% and Annelida (13%. Twenty one species previously reported as aliens, were upon consideration, reclassified as range-expanding Atlantic species. Amathia verticillata, previously considered native to the Mediterranean, is reclassified as pseudoindigenous. Twenty one alien species are newly recorded from Tunisia, including 5 fish species, 5 polychaetes, 4 crustaceans, 4 molluscs, and one each schyphozoan, bryozoan and tunicate. The findings of Gibberulus gibberulus albus, Morula aspera and Calcinus latens, three species new to the Mediterranean, and of Actaedoes tomentosus, reported for the second time in the basin, are described. Species were classified according to their establishment status and their origins. This contribution highlights the dual origin of biological invasion in Tunisian waters (Red Sea and Atlantic, with slightly more species of Red Sea and Indo-Pacific origin (61,76%.  The impact of the alien species in Tunisian waters was discussed.

  20. Validation of a an analysis method of Marine Bio toxins Type Saxitoxin based on test coupled receptor (RBA) with Radiochemical Detection with liquid scintillation

    International Nuclear Information System (INIS)

    Selmi, Zied

    2009-01-01

    The saxitoxin s are bio toxins belonging to the family of toxins of the type PSP. They are paralysing toxins secreted by marine micro-organisms, phytoplankton, called Alexandrium. They constitute a risk for the human health in the event of their consumption in contaminated food. The acceptable maximum limit of these bio toxins in molluscs and shellfish is fixed to 800 μg /kg of meat of molluscs or shellfish. It proves, thus, that it is essential to develop and validate analytical methods for the level monitoring of contamination of the marine resources by these species in order to found a program of their monitoring and to guarantee an acceptable level of the food safety of the products available on the national and international markets. The present work allowed the validation of the quantification method of these toxins which is based on the use of the Receptor Binding Assay (RBA) with liquid scintillation nuclear technique detection using tritium as radiotracer and while proceeding by the different statistical tests of validation (Standard Nf XP T 90-210). The field of linearity ranged from 0 to 20 n M and the limit of detection was found to be 1 n M. The validation of this method will allow the reinforcement of the analytical means of analysis of marine bi toxins type SXT and to set up, in the near future, a monitoring and surveillance routine program for these bio toxins at the national, regional and African scales. (Author)

  1. Concentration of radionuclides by marine organisms and their food chain

    International Nuclear Information System (INIS)

    Nakahara, Motokazu

    1993-01-01

    Accumulation of radionuclides from seawater and from food by marine organisms was observed in the laboratory experiments to get bioconcentration parameters for the nuclides. The radionuclides investigated were 57 Co, 95m Tc, 103 Ru, 137 Cs, 65 Zn and 54 Mn. Several species of molluscs containing pelecypods, gastropods and cephalopod were used for the experimental organisms. For the uptake experiment from seawater, the organisms were kept for more than seven days in radioactive seawater containing those radionuclides together. Then the organisms were transferred into non-radioactive seawater to observe the loss of the nuclides from the organisms. Biphasic loss curves were observed for all of the nuclides. Bioconcentration parameters, such as uptake rate, excretion rate, biological half-life and concentration factor at steady state were estimated from the uptake and excretion curves of the nuclides by the organisms by applying an exponential model. In the uptake experiments from radioactive food, the phytoplankton (Tetraselmis tetrathele), the brown algae (Eisenia bicyclis) and the viscera of abalone were fed to bivalves, herbivorous gastropods and carnivorous molluscs, respectively. After single feeding of the labelled food with the nuclides, retention of the nuclides in whole body of the organisms was followed for several weeks or more. The organisms showed relatively high retention of the nuclides in whole body, except 137 Cs and 54 Mn. Retention of 137 Cs and 54 Mn in the organisms one day after feeding of radioactive food was lower than 25 % of the radioactivity dosed. (author)

  2. Share Contract Choices and Economic Performance

    DEFF Research Database (Denmark)

    Salazar Espinoza, César Antonio

    2015-01-01

    framework, we estimate a dose-response function to study the formation of contracts and identify the marginal effects of changes in crew profit shares on fishing returns in Chilean artisanal fisheries. The results support share contract choices based on bargaining power, monitoring costs, technology, state...... of fishing resources, and outside options. We find significant effects of increasing crew profit shares on vessel owner returns in the interval (0.25, 0.65). The results vary across fisheries, however. While the effects are not significant in the fish group, they are larger and robust for molluscs...

  3. Nuclear chemistry research. Annual progress report, 1 January 1974--31 December 1974

    International Nuclear Information System (INIS)

    Wolke, R.L.

    1974-01-01

    The charge-state program was directed toward heavier ions than had been studied previously. The low-level counting program was continued in two projects: a search for natural alpha radioactivity in osmium and a search for strontium activity in marine mollusc shells. In parallel with the latter work, a comprehensive literature review was made of the applications of radiochemistry to oceanographic research. A new, non-experimental project was begun: a general, consistent mathematical analysis of low-level counting statistics. Improvements in facilities and equipment are reported. (U.S.)

  4. Mid-Pacific Marine Laboratory. Annual report for the period, 1 October 1977--30 September 1978

    Energy Technology Data Exchange (ETDEWEB)

    Reese, E.S.; Johnson, V.R. Jr.

    1979-03-01

    Studies on behavior included reproduction and sociobiology of reef fishes and aggression, hearing, and ultrasonic telemetry in sharks. Ecological studies included population, growth, and mortality studies on birds, corals, crustacea, echinoderms, fishes, molluscs, and rats. Geochemistry studies included biogeochemistry of reef organisms and hydrogeochemistry of groundwater. Geology studies included bioerosion of sea urchins, biology of endolithic processes, and survey of soils. Oceanography studies were conducted on lagoon circulation. Physiological studies were conducted on symbiosis in corals and utilization of organic material by Foraminifera. Studies on systematics of algae, echinoderms, and fishes were conducted. (HLW)

  5. Androgen metabolism in invertebrates and its modulation by xenoandrogens: a comparative study.

    Science.gov (United States)

    Janer, G; Leblanc, G A; Porte, C

    2005-04-01

    Marisa cornuarietis (Mollusc), Hyalella azteca (Crustacean), and Paracentrotus lividus (Echinoderm) demonstrated the ability to metabolize androgens through different pathways catalyzed by 5alpha-reductases (5alpha-R), hydroxysteroid dehydrogenases (HSD), hydroxylases, sulfotransferases (SULT), and fatty-acid acyl-CoA acyltransferases (ATAT). Interspecies differences and tissue-specific distribution of those enzymatic activities were observed. Xenobiotics, such as triphenyltin, tributyltin, and fenarimol, interfered with some of the pathways studied, namely, testosterone sulfation, testosterone esterification, and 5alpha-R activity. The work evidenced different sensitivity of those pathways to androgenic compounds, together with interphyla differences in androgen metabolism.

  6. Diversity of marine invertebrates in a thermal effluent

    International Nuclear Information System (INIS)

    Logan, D.T.; Maurer, D.

    1975-01-01

    Invertebrates were collected at four sites in the Indian River and Indian River Bay in Delaware to study the effects of thermal effluents from a steam-generating plant. A list of species of anemones, nemerteans, annelids, molluscs, and crustaceans is presented. Differences in species composition, an increase in relative numbers of a pollution indicator organism, and reduction in species number and in the total number of organisms in the effluent were noted. The period of highest diversity corresponded to that of the lowest numbers of species and individuals and highest effluent temperatures. (U.S.)

  7. Mercury in marine organisms of the Tay region

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A M; Jones, Y; Stewart, W D.P.

    1972-07-21

    The problem of mercury pollution in the Tay region of the United Kingdom is discussed with emphasis on mercury concentration within marine algae and invertebrates. High levels of Hg were found in Broughty Ferry algae while there was no detectable mercury in any of the samples collected from north of Arbroath. Most was found in the thallose algae, Ulva lactuca and Porphyra umbilicalis, and in Ceramium rubrum. In studies carried out on molluscs, high levels were found in the lamellibranch, Mytilus edulis and in the gastropods Littorina littoralis and Nucella lapillus. 12 references, 3 tables.

  8. A checklist of malacofauna of the Vellar Estuarine Mangroves, India

    Directory of Open Access Journals (Sweden)

    K. Kesavan

    2009-07-01

    Full Text Available A survey conducted to know the diversity of malacofauna in Vellar estuarine mangroves (southeast coast of India. In this study, 13 species of molluscs (10 species of gastropods - Melampus ceylonicus, Cerithidea cingulata, Cassidula nucleus, Pythia plicata, Neritina (Dostia violacea, Littorina scabra, Littorina melanostoma, Ellobium aurisjudae, C. obtusa T. telescopium and Assiminea nitida and 3 species of bivalves - Perna viridis, Crassostrea madrasensis and Modiolus metcalfei were recorded. M. pulchella, C. obtusa, L. scabra and N. violacea were found arboreal. T. telescopium, C. cingulata and E. aurisjudae were found crawling on the intertidal mud.

  9. Pb and Sr isotopes and trace metals in molluscs: constraints on metal sources and water fluxes in a coastal lagoon (Thau, France); Isotope du Pb, du Sr et metaux traces dans les mollusques: contraintes sur les sources de metaux et les mouvements d'eaux dans une lagune cotiere (Thau, France)

    Energy Technology Data Exchange (ETDEWEB)

    Labonne, M

    1998-07-01

    Because of its unique ability to characterize the origins and quantify the fluxes of waters and their loads, isotopic geochemistry is being increasingly used in environmental problems. On the other hand, molluscs are known to concentrate metals in a very strong manner and equilibrate relatively rapidly with their environment. They are used in many programs of coastal survey (Mussel Watch, RNO,...). The originality of our work is to apply isotopic systems (Pb, Sr) to living organisms, in order to: 1- identify the metal sources; 2- determine their proportions in the lagoon and 3- to trace the water movements. The Thau lagoon (Herault, S. France) presents various potential sources of metals inputs: heavy traffic road, Sete harbour, various industries (cement factory, fertilizers...), agriculture, camping areas and leisure ports, not to mention natural (rock) sources. Our study deals with the metal and alkali, alkali-earth concentrations, Pb and Sr isotopes determined on both mussels implanted in the lagoon and wild mussels. We also compare our mussel results with those determined on clams which live at the water/sediments interface. A first study deals with the metal accumulation in laboratory experiments using mono-isotopic tracers 'spike'. It shows that the new metal is being superimposed to the metals initially present in the organisms; this effect is seen within a few days, although variable depending on elements (Zn, Cd, Pb). We have sampled the introduced mussels 4 times a year and we see that the concentration fluctuations are principally related to animal weight variations. The flesh isotopic compositions usually define nice alignments depending on season, indicative of a progressive mixing between two main components: one natural, one anthropogenic. Depending on winds,two influences of seawater entries orlocal water treatment plants effluents can be shown. We have compared past and present metal levels and origins in the area by analysing also

  10. An innovative statistical approach for analysing non-continuous variables in environmental monitoring: assessing temporal trends of TBT pollution.

    Science.gov (United States)

    Santos, José António; Galante-Oliveira, Susana; Barroso, Carlos

    2011-03-01

    The current work presents an innovative statistical approach to model ordinal variables in environmental monitoring studies. An ordinal variable has values that can only be compared as "less", "equal" or "greater" and it is not possible to have information about the size of the difference between two particular values. The example of ordinal variable under this study is the vas deferens sequence (VDS) used in imposex (superimposition of male sexual characters onto prosobranch females) field assessment programmes for monitoring tributyltin (TBT) pollution. The statistical methodology presented here is the ordered logit regression model. It assumes that the VDS is an ordinal variable whose values match up a process of imposex development that can be considered continuous in both biological and statistical senses and can be described by a latent non-observable continuous variable. This model was applied to the case study of Nucella lapillus imposex monitoring surveys conducted in the Portuguese coast between 2003 and 2008 to evaluate the temporal evolution of TBT pollution in this country. In order to produce more reliable conclusions, the proposed model includes covariates that may influence the imposex response besides TBT (e.g. the shell size). The model also provides an analysis of the environmental risk associated to TBT pollution by estimating the probability of the occurrence of females with VDS ≥ 2 in each year, according to OSPAR criteria. We consider that the proposed application of this statistical methodology has a great potential in environmental monitoring whenever there is the need to model variables that can only be assessed through an ordinal scale of values.

  11. Kahalalide F analogues from the mucous secretion of Indian sacoglossan mollusc Elysia ornata

    Digital Repository Service at National Institute of Oceanography (India)

    Ciavatta, M.L.; PrabhaDevi; Carbone, M.; Mathieu, V.; Kiss, R.; Casapullo, A.; Gavagnin, M.

    , better delivery, or longer half-life. More than 150 analogues were obtained by solid phase peptide synthesis8,9 and more recently a semi-synthetic approach to produce KF analogues starting from natural KF has been also performed.10In parallel...

  12. Monitoring the presence of domoic acid in the production areas of bivalve molluscs

    Directory of Open Access Journals (Sweden)

    Rachele Rossi

    2016-09-01

    Full Text Available Algal biotoxins, chemical compounds produced by some microscopic algae, constitute the phytoplankton. The mussels, feeding on phytoplankton, can accumulate these compounds to become themselves toxic. There have been several cases of food poisoning by consumption of contaminated shellfish. Such food poisoning have pushed our health care system to provide monitoring of shellfish in the framework of the monitoring plans carried out by AASSLL. In this paper we report the results obtained monitoring the presence of amnesic shellfish poisoning biotoxins, like domoic acid and its isomers, produced by Pseudonitzschia algae. The analyses were carried out by using both the high-performance liquid chromatography- ultraviolet official method and an experimental method performed with a time-offlight mass spectrometer (ESI-TOF. The 100% of samples analysed by the official method have always been below the limits of sensitivity (except one sample, and the 65% of samples analysed by ESI-TOF showed the presence of domoic acid.

  13. Survival of egg-laying controlling neuroendocrine cells during reproductive senescence of a mollusc

    NARCIS (Netherlands)

    Janse, C.

    2004-01-01

    During brain aging neuronal degradation occurs. In some neurons this may result in degeneration and cell death, still other neurons may survive and maintain their basic properties. The present study deals with survival of the egg-laying controlling neuroendocrine caudodorsal cells (CDCs) during

  14. Bonamia parasites: a rapidly changing perspective on a genus of important mollusc pathogens

    NARCIS (Netherlands)

    Engelsma, M.Y.; Culloty, S.C.; Lynch, S.A.; Arzul, I.; Carnegie, R.B.

    2014-01-01

    Organisms of the genus Bonamia are intracellular protistan parasites of oysters. To date, 4 species have been described (B. ostreae, B. exitiosa, B. perspora and B. roughleyi), although the status of B. roughleyi is controversial. Introduction especially of B. ostreae and B. exitiosa to naïve host

  15. Zoology: Molluscs All Beneath the Sun, One Shell, Two Shells, More, or None.

    Science.gov (United States)

    Sigwart, Julia D

    2017-07-24

    One great remaining problem in evolutionary biology is to understand which common ancestor could have given rise to descendants as different as giant squid and microscopic pea clams. Two new papers provide important insights into molluscan body plan disparity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. The hydrogeothermal potential of Southern Hesse; Das hydrogeothermische Potential Suedhessens

    Energy Technology Data Exchange (ETDEWEB)

    Fitzer, C; Fluhrer, S; Sanner, B; Knoblich, K [Giessen Univ. (Germany). Inst. fuer Angewandte Geowissenschaften

    1997-12-01

    The paper investigates rock series suited as storage media and the temperature distribution in the subsurface of Southern Hesse. It gives an idea of the possibilities for hydrogeothermal energy use in the area. The densily populated Rhein-Main-region provides a good demand potential for geothermal heat. A substantially elevated geothermal gradient of about 60 K/km as compared to the continental average of 30 K/km could be demonstrated in the northern part of the Upper Rhine Graben. Thermal anomalies could be localised. The Rotliegend-layers (Perm) provide the highest geothermal ressources in the region. In more shallow depth, the Hydrobia layers (Teritary) show reasonable values. To the north, the potential of these series decreases. Hence hydrogeothermal energy use should not be considered in the northern part of Southern Hesse. The highest potential can be expected from the Rotliegend layers in the area of Stockstadt and Biebesheim. (orig.) [Deutsch] Die Untersuchung geht auf die moeglichen Speichergesteine und die Temperaturverteilung im Untergrund Suedhessens ein und gibt einen ersten Eindruck von den Moeglichkeiten zur Nutzung der Hydrogeothermie in der Region. Fuer geothermische Waerme besteht im dicht besiedelten Rhein-Main-Gebiet eine gute Abnehmerstruktur. Im noerdlichen Oberrheingraben konnte im Mittel ein deutlich erhoehter Temperaturgradient von etwa 60 K/km gegenueber dem kontinentalen Krustendurchschnittswert von 30 K/km nachgewiesen werden. Waemeanomalien wurden lokalisiert. Die Rotliegendschichten weisen im untersuchten Gebiet eindeutig die hoechsten Ressourcen auf. In geringerer Tiefenlage erzielen die Hydrobienschichten noch beachtliche Werte. Nach Norden nimmt das Potential der Schichten ab. Daher ist von einer Nutzung der Hydrogeothermie im noerdlichen Bereich Suedhessens eher abzuraten. Die hoechsten Ressourcen in Suedhessen sind im Bereich von Stockstadt und Biebesheim in den Rotliegenschichten zu erwarten. (orig.)

  17. Parasites in the Wadden Sea food web

    Science.gov (United States)

    Thieltges, David W.; Engelsma, Marc Y.; Wendling, Carolin C.; Wegner, K. Mathias

    2013-09-01

    While the free-living fauna of the Wadden Sea has received much interest, little is known on the distribution and effects of parasites in the Wadden Sea food web. However, recent studies on this special type of trophic interaction indicate a high diversity of parasites in the Wadden Sea and suggest a multitude of effects on the hosts. This also includes effects on specific predator-prey relationships and the general structure of the food web. Focussing on molluscs, a major group in the Wadden Sea in terms of biomass and abundance and an important link between primary producers and predators, we review existing studies and exemplify the ecological role of parasites in the Wadden Sea food web. First, we give a brief inventory of parasites occurring in the Wadden Sea, ranging from microparasites (e.g. protozoa, bacteria) to macroparasites (e.g. helminths, parasitic copepods) and discuss the effects of spatial scale on heterogeneities in infection levels. We then demonstrate how parasites can affect host population dynamics by acting as a strong mortality factor, causing mollusc mass mortalities. In addition, we will exemplify how parasites can mediate the interaction strength of predator-prey relationships and affect the topological structure of the Wadden Sea food web as a whole. Finally, we highlight some ongoing changes regarding parasitism in the Wadden Sea in the course of global change (e.g. species introduction, climate change) and identify important future research questions to entangle the role of parasites in the Wadden Sea food web.

  18. Marine Mollusca of isotope stages of the last 2 million years in New Zealand. Part 3, Gastropoda (Vetigastropoda - Littorinimorpha)

    International Nuclear Information System (INIS)

    Beu, A.G.

    2010-01-01

    Three new species: Grandicrepidula hemispherica (Nukumaruan, S Hawke's Bay), Pelicaria Granttaylori (Mangapanian-early Nukumaruan, Wanganui-Hawke's Bay), Pelicaria arahura (Waipipian-early Mangapanian, Westland and Hawke's Bay). Drawings of marine species in Smith's (1874) three plates of New Zealand molluscan types are republished. Further Australian molluscs in Wanganui Basin: Sabia australis (Lamarck), Clanculus plebejus (Philippi), both early Nukumaruan. Further northern New Zealand molluscs in Wanganui Basin: Stephopoma roseum (Quoy and Gaimard), OIS 13, 9. Distinctive gastropods extinct at end Nukumaruan: Struthiolaria frazeri (Hutton), Taxonia suteri (Marwick). Taniella planisuturalis (Marwick) (Opoitian-Nukumaruan, southern NZ) and Trivia (Ellatrivia) zealandica (Kirk) (Nukumaruan, Hawke's Bay-Wanganui; Castlecliffian, North Canterbury) occur in Castlecliffian (OIS 15?) rocks at Whakatane. Cantharidella tessellate (A. Adams) and Risellopsis varia (Hutton), formerly Haweran, are recorded from Nukumaruan and Castlecliffian rocks, respectively. New fossil late Nukumaruan-early Castlecliffian records listed from Mikonui-1 offshore well, Westland, include Malluvium calcareum (Suter) and 10 other species. Other biostratigraphically useful gastropods: Calliostoma (Maurea) nukumaruense (Laws) (Mangapanian-OIS 17); Argobuccinum pustulosum (Lightfoot), Semicassis labiate (Perry) (both earliest in OIS 7). New synonymy: Zeacumantus perplexus (Marshall and Murdoch) =Z. lutulentus (Kiener); Pelicaria vermis (Martyn) =all named Nukumaruan-Recent forms (other than P. rugosa (Marwick) and P. granttaylori n. sp.); Trivia flora Marwick =T.zealandica Kirk. Taxonomy revised: Zelippistes benhami (Suter) (OIS 13 and 9 at Wanganui), distinguished from Lippistes and Separatista; Stiracolpus species, informally; Maoricrypta profunda (Hutton), Waipipian-early Castlecliffian (- OIS 19); M. radiata (Hutton) (=incurva Zittel,=hochetteriana Woods, =wilckensi Finlay), (Middle Miocene

  19. The assessment of ionising radiation impact on the cooling pond freshwater ecosystem non-human biota from the Ignalina NPP operation beginning to shut down and initial decommissioning.

    Science.gov (United States)

    Mazeika, J; Marciulioniene, D; Nedveckaite, T; Jefanova, O

    2016-01-01

    The radiological doses to non-human biota of freshwater ecosystem in the Ignalina NPP cooling pond - Lake Druksiai were evaluated for several cases including the plant's operation period and initial decommissioning activities, using the ERICA 1.2 code with IAEA SRS-19 models integrated approach and tool. Among the Lake Druksiai freshwater ecosystem reference organisms investigated the highest exposure dose rate was determined for bottom fauna - benthic organisms (mollusc-bivalves, crustaceans, mollusc-gastropods, insect larvae), and among the other reference organisms - for vascular plants. The mean and maximum total dose rate values due to anthropogenic radionuclide ionising radiation impact in all investigated cases were lower than the ERICA screening dose rate value of 10 μGy/h. The main exposure of reference organisms as a result of Ignalina NPP former effluent to Lake Druksiai is due to ionizing radiation of radionuclides (60)Co and (137)Cs, of predicted releases to Lake Druksiai during initial decommissioning period - due to radionuclides (60)Co, (134)Cs and (137)Cs, and as a result of predicted releases to Lake Druksiai from low- and intermediate-level short-lived radioactive waste disposal site in 30-100 year period - due to radionuclides (99)Tc and (3)H. The risk quotient expected values in all investigated cases were <1, and therefore the risk to non-human biota can be considered negligible with the exception of a conservative risk quotient for insect larvae. Radiological protection of non-human biota in Lake Druksiai, the Ignalina NPP cooling pond, is both feasible and acceptable. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Phylogeny and mitochondrial gene order variation in Lophotrochozoa in the light of new mitogenomic data from Nemertea

    Directory of Open Access Journals (Sweden)

    von Döhren Jörn

    2009-08-01

    Full Text Available Abstract Background The new animal phylogeny established several taxa which were not identified by morphological analyses, most prominently the Ecdysozoa (arthropods, roundworms, priapulids and others and Lophotrochozoa (molluscs, annelids, brachiopods and others. Lophotrochozoan interrelationships are under discussion, e.g. regarding the position of Nemertea (ribbon worms, which were discussed to be sister group to e.g. Mollusca, Brachiozoa or Platyhelminthes. Mitochondrial genomes contributed well with sequence data and gene order characters to the deep metazoan phylogeny debate. Results In this study we present the first complete mitochondrial genome record for a member of the Nemertea, Lineus viridis. Except two trnP and trnT, all genes are located on the same strand. While gene order is most similar to that of the brachiopod Terebratulina retusa, sequence based analyses of mitochondrial genes place nemerteans close to molluscs, phoronids and entoprocts without clear preference for one of these taxa as sister group. Conclusion Almost all recent analyses with large datasets show good support for a taxon comprising Annelida, Mollusca, Brachiopoda, Phoronida and Nemertea. But the relationships among these taxa vary between different studies. The analysis of gene order differences gives evidence for a multiple independent occurrence of a large inversion in the mitochondrial genome of Lophotrochozoa and a re-inversion of the same part in gastropods. We hypothesize that some regions of the genome have a higher chance for intramolecular recombination than others and gene order data have to be analysed carefully to detect convergent rearrangement events.