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Sample records for bivalve mollusk species

  1. Microbial Diseases of Bivalve Mollusks: Infections, Immunology and Antimicrobial Defense.

    Science.gov (United States)

    Zannella, Carla; Mosca, Francesco; Mariani, Francesca; Franci, Gianluigi; Folliero, Veronica; Galdiero, Marilena; Tiscar, Pietro Giorgio; Galdiero, Massimiliano

    2017-06-17

    A variety of bivalve mollusks (phylum Mollusca, class Bivalvia) constitute a prominent commodity in fisheries and aquacultures, but are also crucial in order to preserve our ecosystem's complexity and function. Bivalve mollusks, such as clams, mussels, oysters and scallops, are relevant bred species, and their global farming maintains a high incremental annual growth rate, representing a considerable proportion of the overall fishery activities. Bivalve mollusks are filter feeders; therefore by filtering a great quantity of water, they may bioaccumulate in their tissues a high number of microorganisms that can be considered infectious for humans and higher vertebrates. Moreover, since some pathogens are also able to infect bivalve mollusks, they are a threat for the entire mollusk farming industry. In consideration of the leading role in aquaculture and the growing financial importance of bivalve farming, much interest has been recently devoted to investigate the pathogenesis of infectious diseases of these mollusks in order to be prepared for public health emergencies and to avoid dreadful income losses. Several bacterial and viral pathogens will be described herein. Despite the minor complexity of the organization of the immune system of bivalves, compared to mammalian immune systems, a precise description of the different mechanisms that induce its activation and functioning is still missing. In the present review, a substantial consideration will be devoted in outlining the immune responses of bivalves and their repertoire of immune cells. Finally, we will focus on the description of antimicrobial peptides that have been identified and characterized in bivalve mollusks. Their structural and antimicrobial features are also of great interest for the biotechnology sector as antimicrobial templates to combat the increasing antibiotic-resistance of different pathogenic bacteria that plague the human population all over the world.

  2. Histological techniques for marine bivalve mollusks and crustaceans, 2nd edition

    OpenAIRE

    Howard, Dorothy W.; Lewis, Earl J.; Keller, B. Jane; Smith, Cecelia S.

    2004-01-01

    Investigators at the Cooperative Oxford Laboratory (COL) diagnose and study crustaceans, mollusks, finfish, and a variety of other marine and estuarine invertebrates to assess animal health. This edition updates the Histological Techniques for Marine Bivalve Mollusks manual by Howard and Smith (1983) with additional chapters on molluscan and crustacean techniques. The new edition is intended to serve as a guide for histological processing of shellfish, principally bivalve mollusks and crustac...

  3. Mobile Element Evolution Playing Jigsaw - SINEs in Gastropod and Bivalve Mollusks.

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    Matetovici, Irina; Sajgo, Szilard; Ianc, Bianca; Ochis, Cornelia; Bulzu, Paul; Popescu, Octavian; Damert, Annette

    2016-01-06

    SINEs (Short INterspersed Elements) are widely distributed among eukaryotes. Some SINE families are organized in superfamilies characterized by a shared central domain. These central domains are conserved across species, classes, and even phyla. Here we report the identification of two novel such superfamilies in the genomes of gastropod and bivalve mollusks. The central conserved domain of the first superfamily is present in SINEs in Caenogastropoda and Vetigastropoda as well as in all four subclasses of Bivalvia. We designated the domain MESC (Romanian for MElc-snail and SCoica-mussel) because it appears to be restricted to snails and mussels. The second superfamily is restricted to Caenogastropoda. Its central conserved domain-Snail-is related to the Nin-DC domain. Furthermore, we provide evidence that a 40-bp subdomain of the SINE V-domain is conserved in SINEs in mollusks and arthropods. It is predicted to form a stable stem-loop structure that is preserved in the context of the overall SINE RNA secondary structure in invertebrates. Our analysis also recovered short retrotransposons with a Long INterspersed Element (LINE)-derived 5' end. These share the body and/or the tail with transfer RNA (tRNA)-derived SINEs within and across species. Finally, we identified CORE SINEs in gastropods and bivalves-extending the distribution range of this superfamily. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  4. Irradiated bivalve mollusks: Use of EPR spectroscopy for identification and dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Alberti, Angelo, E-mail: aalberti@isof.cnr.it [CNR-ISOF, Area della Ricerca di Bologna, Via P. Gobetti 101, Bologna I-40129 (Italy); Chiaravalle, Eugenio [Istituto Zooprofilattico Sperimentale della Puglia e Basilicata, Via Manfredonia 20, Foggia I-71100 (Italy); Fuochi, Piergiorgio; Macciantelli, Dante [CNR-ISOF, Area della Ricerca di Bologna, Via P. Gobetti 101, Bologna I-40129 (Italy); Mangiacotti, Michele, E-mail: michelemangiacotti@libero.it [Istituto Zooprofilattico Sperimentale della Puglia e Basilicata, Via Manfredonia 20, Foggia I-71100 (Italy); Marchesani, Giuliana [Istituto Zooprofilattico Sperimentale della Puglia e Basilicata, Via Manfredonia 20, Foggia I-71100 (Italy); Plescia, Elena [CNR-ISOF, Area della Ricerca di Bologna, Via P. Gobetti 101, Bologna I-40129 (Italy)

    2011-12-15

    High energy radiation treatment of foodstuff for microbial control and shelf-life extension is being used in many countries. However, for consumer protection and information, the European Union has adopted the Directives 1999/2/EC and 1999/3/EC to harmonize the rules concerning the treatment and trade of irradiated foods in EU countries. Among the validated methods to detect irradiated foods the EU directives also include Electron Paramagnetic Resonance (EPR/ESR) spectroscopy. We describe herein the use of EPR for identification of four species of bivalve mollusks, i.e. brown Venus shells (Callista chione), clams (Tapes semidecussatus), mussels (Mytilus galloprovincialis) and oysters (Ostrea edulis) irradiated with {sup 60}Co {gamma}-rays. EPR could definitely identify irradiated seashells due to the presence of long-lived free radicals, primarily CO{sub 2}{sup -}, CO{sub 3}{sup 3-}, SO{sub 2}{sup -} and SO{sub 3}{sup -} radical anions. The presence of other organic free radicals, believed to originate from conchiolin, a scleroprotein present in the shells, was also ascertained. The use of one of these radicals as a marker for irradiation of brown Venus shells and clams can be envisaged. We also propose a dosimetric protocol for the reconstruction of the administered dose in irradiated oysters. - Highlights: > EPR spectroscopy is confirmed a valuable identification tool for irradiated mollusks. > A conchiolin-derived radical can be used as irradiation marker for some mollusks. > A reliable protocol is outlined for dose reconstruction of irradiated oysters.

  5. Investigation into Cryptosporidium and Giardia in bivalve mollusks farmed in Sardinia region and destined for human consumption

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    Tiziana Tedde

    2013-06-01

    Full Text Available Cryptosporidium and Giardia are protozoan parasites transmitted by fecal-oral ingestion of (oocysts, and are responsible for enteritis in several animal species and humans worldwide. These (oocysts can survive for over a year in aquatic environments and can accumulate in bivalve mollusks, which filter large volumes of water. The aim of this study is to evaluate the natural occurrence of Cryptosporidium and Giardia contamination in different specimens of edible bivalves mollusks from farming sites of the western and north-eastern coasts of Sardinia. From April 2011 to February 2012, 1095 specimens of Mytilus galloprovincialis and 240 of Crassostrea gigas were sampled from Olbia and Oristano gulf and San Teodoro pond. Hepatopancreas and gills, including the labial palp, were examined for oocysts and cysts after pooling and homogenisation using different techniques: i staining for light and fluorescence microscopy; ii direct immunofluorescence (IF Merifluor® test Cryptosporidium/ Giardia (Meridian Bioscience Inc., Cincinnati, OH, USA; and iii molecular procedures. However, in the context under study, all mollusks examined with the three main diagnostic techniques were negative for both parasites pointing out the hypothetically low zoonotic risk related to Cryptosporidium and Giardia in bivalves, especially Mytilus galloprovincialis and Crassostrea gigas.

  6. Mobile Element Evolution Playing Jigsaw—SINEs in Gastropod and Bivalve Mollusks

    Science.gov (United States)

    Matetovici, Irina; Sajgo, Szilard; Ianc, Bianca; Ochis, Cornelia; Bulzu, Paul; Popescu, Octavian; Damert, Annette

    2016-01-01

    SINEs (Short INterspersed Elements) are widely distributed among eukaryotes. Some SINE families are organized in superfamilies characterized by a shared central domain. These central domains are conserved across species, classes, and even phyla. Here we report the identification of two novel such superfamilies in the genomes of gastropod and bivalve mollusks. The central conserved domain of the first superfamily is present in SINEs in Caenogastropoda and Vetigastropoda as well as in all four subclasses of Bivalvia. We designated the domain MESC (Romanian for MElc—snail and SCoica—mussel) because it appears to be restricted to snails and mussels. The second superfamily is restricted to Caenogastropoda. Its central conserved domain—Snail—is related to the Nin-DC domain. Furthermore, we provide evidence that a 40-bp subdomain of the SINE V-domain is conserved in SINEs in mollusks and arthropods. It is predicted to form a stable stem-loop structure that is preserved in the context of the overall SINE RNA secondary structure in invertebrates. Our analysis also recovered short retrotransposons with a Long INterspersed Element (LINE)-derived 5′ end. These share the body and/or the tail with transfer RNA (tRNA)-derived SINEs within and across species. Finally, we identified CORE SINEs in gastropods and bivalves—extending the distribution range of this superfamily. PMID:26739168

  7. Optimal designs of mollusk shells from bivalves to snails.

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    Okabe, Takuya; Yoshimura, Jin

    2017-02-10

    Bivalve, ammonite and snail shells are described by a small number of geometrical parameters. Raup noted that the vast majority of theoretically possible shell forms do not occur in nature. The constraint factors that regulate the biased distribution of natural form have long since been an open problem in evolution. The problem of whether natural shell form is a result of optimization remains unsolved despite previous attempts. Here we solve this problem by considering the scaling exponent of shell thickness as a morphological parameter. The scaling exponent has a drastic effect on the optimal design of shell shapes. The observed characteristic shapes of natural shells are explained in a unified manner as a result of optimal utilization of shell material resources, while isometric growth in thickness leads to impossibly tight coiling.

  8. [Nutrition and biological value of food parts of a trade bivalve mollusk Anadara broughtoni].

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    Tabakaeva, O V; Tabakaev, A V

    2015-01-01

    Currently, the human diet includes different new products of seafishing, including non-fish--bivalves and gastropods, holothurias, echinoderms, jellyfishes that demands careful studying of their chemical composition. The purpose of the study was to determine the nutritional and biological value of all soft parts of the burrowing bivalve MOLLUSK Anadara broughtoni from the Far East region. It was established thatfood parts of a bivalve were significantly flooded (water content--73.5-84.2%), with the minimum water content in the adductor and maximum in the mantle. Dry solids are presented by organic (89-93%) and mineral (7-11%) components. Organic components consist of protein (14.6-20.7%), lipids (1.8-2.3%), carbohydrates (2.1-2.6%). The analysis of amino-acid composition of proteins of food parts of the mollusk of Anadara broughtonishowed the presence of all essential amino acids with slight differences in their content depending on the localization of the protein. All edible parts have tryptophan as the limiting amino acid. Muscle proteins have maximum level of lysine, methionine, cysteine, phenylalanine and tyrosine; mantle proteins--leucine, isoleucine and threonine; adductor proteins--valine, phenylalanine, tyrosine, methionine and cysteine. Predominant nonessential amino acids forproteins of all food pieces are glycine, aspartic acid, glutamic acid, arginine. The coefficient of amino-acid score differences of adductor protein (31.7%) is less than the same of cloak by 3.7%. The indicator "biological value" is maximal for adductor (68.3%), but the differenceformuscle is only 0.83%. Mantle proteins are characterized by minimum biological value (64.6%). The coefficient of utility of amino acid composition of protein is maximalfor muscle (57.83%), and values for a cloak and an adductor differ slightly (55.81 and 55.96%). Taurine content in food parts of a mollusk Anadara broughtoni is rather high compared to with other bivalve mollusks of the Far East region

  9. Marine Bacteria with antimicrobials capacity isolated from cultures of bivalve mollusks

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    Fabiola Pellon

    2014-06-01

    Full Text Available Microorganisms have commonly been studied as producers of antibacterial substances; yet they are also considered producers of antifungic, antiviral, antiparasitic, citotoxics and inhibitory of other forms of cellular growth substances. This paper describes the isolation, inhibitory potential and phenotipic characterization of native bacterial strains associated to bivalve mollusks such as Argopecten purpuratus “concha de abanico” and Crassostrea gigas “ostra” in cultivation systems. From 345 marine strains collected, 20 strains were recovered that had the ability of inhibiting a wide spectrum of fish, mollusks and shellfish pathogenic bacteria; being the most sensitive pathogens Aeromonas sobria P-281, Aeromonas hydrophila ATCC 7966, Vibrio vulnificus ATCC 27562 and Vibrio parahaemolyticus ATCC 17803. The phenotipic characterization of this strains with inhibitory capacity allowed the identification of the following genera: Vibrio (40%, Aeromonas (15%, Flavobacterium (10%, Pseudomonas (5%, Moraxella (5%, Flexibacter (5%. A 20% could not be identified. The results suggest that the isolated bacteria could be used as probiotics agents for the biological control of pathogens from marine organisms of interest in mariculture.

  10. North Atlantic Oscillation dynamics recorded in shells of a long-lived bivalve mollusk

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    Schöne, Bernd R.; Oschmann, Wolfgang; Rössler, Jochen; Freyre Castro, Antuané D.; Houk, Stephen D.; Kröncke, Ingrid; Dreyer, Wolfgang; Janssen, Ronald; Rumohr, Heye; Dunca, Elena

    2003-12-01

    Existing reconstructions of the winter North Atlantic Oscillation (WNAO) are based on terrestrial proxies and historical documents. No direct high-resolution, long-term rec ords from marine settings are available for this major climate-dictating phenomenon, which severely affects a variety of economic aspects of our society. Here we present a 245 yr proxy WNAO index based on shells of the long-lived marine bivalve mollusk Arctica islandica. Variations in annual rates of shell growth are positively correlated with WNAO-related changes in the food supply. Maximum amplitudes in frequency bands of 7 9 and 5 7 yr fall exactly within the range of instrumental and other proxy WNAO indices. These estimates were obtained for specimens collected live, 2000 km apart, in the central North Sea and on the Norwegian Shelf. Hence, the WNAO influences hydrographic regimes of large regions of the ocean. Our study demonstrates that A. islandica can reliably reconstruct WNAO dynamics for time intervals and regions without instrumental records. Our new tool functions as a proxy for the WNAO index prior to the twentieth-century greenhouse forcing and has the potential to further validate other proxy-based WNAO records.

  11. Occurrence of potentially pathogenic Vibrio in oysters (Crassostrea gigas) and waters from bivalve mollusk cultivations in the South Bay of Santa Catarina.

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    Ramos, Roberta Juliano; Miotto, Letícia Adélia; Miotto, Marília; Silveira Junior, Nelson; Cirolini, Andréia; Silva, Helen Silvestre da; Rodrigues, Dália dos Prazeres; Vieira, Cleide Rosana Werneck

    2014-01-01

    This research aimed to identify and quantify potentially pathogenic Vibrio from different cultivations of bivalve shellfish in the State of Santa Catarina, Brazil, and water regions in the South Bay, as well as correlate the incidence of these microorganisms with the physicochemical parameters of marine waters. Between October 2008 and March 2009, 60 oyster and seawater samples were collected from six regions of bivalve mollusk cultivation, and these samples were submitted for Vibrio counts. Twenty-nine (48.3%) oyster samples were revealed to be contaminated with one or more Vibrio species. The Vibrio parahaemolyticus and Vibrio vulnificus counts in the samples ranged from oyster and from oyster, respectively. Of the 60 seawater samples analyzed, 44 (73.3%) showed signs of contamination with one or more vibrio species. The counts of V. parahaemolyticus and V. vulnificus in the samples ranged from < 0.3 log10 MPN·100mL(-1) to 1.7 log10MPN·100mL(-1) seawater and from < 0.3 log10 MPN·100mL(-1) to 2.0 log10 MPN·100mL(-1) seawater, respectively. A positive correlation between V. vulnificus counts and the seawater temperature as well as a negative correlation between the V. parahaemolyticus counts and salinity were observed. The results suggest the need to implement strategies to prevent vibrio diseases from being transmitted by the consumption of contaminated bivalve shellfish.

  12. Ultrasound assisted enzymatic hydrolysis for isolating titanium dioxide nanoparticles from bivalve mollusk before sp-ICP-MS.

    Science.gov (United States)

    Taboada-López, María Vanesa; Iglesias-López, Sara; Herbello-Hermelo, Paloma; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2018-08-14

    Applicability of single-particle inductively coupled plasma mass spectrometry (sp-ICP-MS) using dwell times equal to or shorter than 100 μs has been tested for assessing titanium dioxide nanoparticles (TiO 2 NPs) in bivalve mollusks. TiO 2 NPs isolation from fresh mollusk tissues was achieved by ultrasound assisted enzymatic hydrolysis procedure using a pancreatin/lipase mixture. Optimum extraction conditions imply ultrasonication (60% amplitude) for 10 min, and 7.5 mL of a solution containing 3.0 g L -1 of pancreatin and lipase (pH 7.4). The developed method was found to be repeatable (repeatability of 17% for the over-all procedure, TiO 2 NPs concentration of 5.33 × 10 7  ± 8.89 × 10 6 , n = 11), showing a limit of detection of 5.28 × 10 6 NPs g -1 , and a limit of detection in size of 24.4-30.4 nm, based on the 3σ criteria, and on the 3σ/5 σ criteria, respectively. The analytical recovery within the 90-99% range (use of TiO 2 NPs standards of 50 nm at 7 and 14 μg L -1 as Ti). Several bivalve mollusks (clams, cockles, mussels, razor clams, oysters and variegated scallops) were analyzed for total titanium (ICP-MS after microwave assisted acid digestion), and for TiO 2 NPs by the proposed method. TiO 2 NPs concentrations were within the 2.36 × 10 7 -1.25 × 10 8 NPs g -1 range, and the most frequent sizes were from 50 to 70 nm. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Occurrence of potentially pathogenic Vibrio in oysters (Crassostrea gigas and waters from bivalve mollusk cultivations in the South Bay of Santa Catarina

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    Roberta Juliano Ramos

    2014-06-01

    Full Text Available Introduction This research aimed to identify and quantify potentially pathogenic Vibrio from different cultivations of bivalve shellfish in the State of Santa Catarina, Brazil, and water regions in the South Bay, as well as correlate the incidence of these microorganisms with the physicochemical parameters of marine waters. Methods Between October 2008 and March 2009, 60 oyster and seawater samples were collected from six regions of bivalve mollusk cultivation, and these samples were submitted for Vibrio counts. Results Twenty-nine (48.3% oyster samples were revealed to be contaminated with one or more Vibrio species. The Vibrio parahaemolyticus and Vibrio vulnificus counts in the samples ranged from < 0.5 log10 Most Probable Number (MPN g–1 to 2.3 log10 MPN g–1 oyster and from < 0.5 log10 MPN g–1 to 2.1 log10 MPN g–1 oyster, respectively. Of the 60 seawater samples analyzed, 44 (73.3% showed signs of contamination with one or more vibrio species. The counts of V. parahaemolyticus and V. vulnificus in the samples ranged from < 0.3 log10 MPN·100mL–1 to 1.7 log10MPN·100mL–1 seawater and from < 0.3 log10 MPN·100mL–1 to 2.0 log10 MPN·100mL–1 seawater, respectively. A positive correlation between V. vulnificus counts and the seawater temperature as well as a negative correlation between the V. parahaemolyticus counts and salinity were observed. Conclusions The results suggest the need to implement strategies to prevent vibrio diseases from being transmitted by the consumption of contaminated bivalve shellfish.

  14. Assessment of heavy metals pollution in the gulf of Gabes (Tunisia using four mollusk species

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    L. RABAOUI

    2013-08-01

    Full Text Available Since the establishment of the ‘Tunisian Chemical Group’ in Gabes city, Tunisia, no serious investigations were carried out about the heavy metal pollution in Gabes gulf.  In the present study, the contents of four heavy metals were assessed in four mollusk species (two gastropods, Gibbula ardens and Patella caerulea, and two bivalves, Pinctada radiata and Pinna nobilis, collected from twelve coastal stations. The results obtained showed generally that high concentrations of heavy metals were recorded in the central area of Gabes gulf, nearer to Gabes city; the low concentrations were in contrast found at the edges of this gulf, which is probably due to the chemical pollution generated from the huge industry of phosphoric acid in Gabes city. Comparing the results found with the four examined species, the lowest concentrations were noted with the two bivalve species P. radiata and P. nobilis. The highest heavy metals’ concentrations, noted during this study, are comparable to the findings of other authors in other areas, but they are considerably beyond the standards. A remediation action is necessarily needed either by reducing the amount of heavy metals in the phosphgypums quantities thrown directly in the sea or by stopping completely this harmful industry to protect the marine life in the area. A remediation action is necessarily needed to protect the marine life in the area.

  15. Persistent organic pollutants in four bivalve species from Svalbard waters

    International Nuclear Information System (INIS)

    Vieweg, Ireen; Hop, Haakon; Brey, Thomas; Huber, Sandra; Ambrose, William G.; Locke V, William L.; Gabrielsen, Geir W.

    2012-01-01

    Organochlorine compounds (OC) were determined in Arctic bivalves (Mya truncata, Serripes groenlandicus, Hiatella arctica and Chlamys islandica) from Svalbard with regard to differences in geographic location, species and variations related to their size and age. Higher chlorinated polychlorinated biphenyls (PCB 101–PCB 194), chlordanes and α-hexachlorocyclohexane (α-HCH) were consistently detected in the bivalves and PCBs dominated the OC load in the organisms. OC concentrations were highest in Mya truncata and the lowest in Serripes groenlandicus. Species-specific OC levels were likely related to differences in the species’ food source, as indicated by the δ 13 C results, rather than size and age. Higher OC concentrations were observed in bivalves from Kongsfjorden compared to the northern sampling locations Liefdefjorden and Sjuøyane. The spatial differences might be related to different water masses influencing Kongsfjorden (Atlantic) and the northern locations (Arctic), with differing phytoplankton bloom situations. - Highlights: ► Organochlorine compounds (OC) were analyzed in 4 bivalve species from Svalbard. ► Polychlorinated biphenyls dominated the OC load observed in the bivalves. ► Atlantic water influenced bivalves had higher OC levels than those from Arctic water. ► Location and species, rather than size and age, determined the OC pattern found. - New findings of organochlorines in Arctic bivalves that are central for evaluating the importance of geographical location and species for the organochlorine pattern in benthic organisms.

  16. Comparative susceptibility of veliger larvae of four bivalve mollusks to a Vibrio alginolyticus strain.

    Science.gov (United States)

    Luna-González, A; Maeda-Martínez, A N; Sainz, J C; Ascencio-Valle, F

    2002-06-03

    The susceptibility of 7 d old veliger larvae of the scallops Argopecten ventricosus and Nodipecten subnodosus, the penshell Atrina maura, and the Pacific oyster Crassostrea gigas to a pathogenic strain of Vibrio alginolyticus was investigated by challenging the larvae with different bacterial concentrations in a semi-static assay. The results indicate that the larvae of the 2 scallop species are more susceptible to the V. alginolyticus strain than those of the oyster and the penshell. Signs of the disease were similar to bacillary necrosis described in previous work. Interspecies differences in susceptibility to pathogens are discussed.

  17. The use of raw and acid-pretreated bivalve mollusk shells to remove metals from aqueous solutions

    International Nuclear Information System (INIS)

    Liu Yang; Sun Changbin; Xu Jin; Li Youzhi

    2009-01-01

    Heavy metal removal from industrial wastewater is not only to protect living organisms in the environment but also to conserve resources such as metals and water by enabling their reuse. To overcome the disadvantage of high cost and secondary pollution by the conventional physico-chemical treatment techniques, environmentally benign and low-cost adsorbents are in demand. In this study, the use of raw and acid-pretreated bivalve mollusk shells (BMSs) to remove metals from aqueous solutions with single or mixed metal was evaluated at different BMSs doses, pH and temperatures in batch shaking experiments in laboratory conditions. When the BMSs were used to treat CuSO 4 .5H 2 O solution, the copper sorption capacities of the raw and acid-pretreated BMSs were approximately 38.93 mg/g and 138.95 mg/g, respectively. The copper removal efficiency (CRE) of the raw BMSs became greatly enhanced with increasing initial pH, reaching 99.51% at the initial pH 5. Conversely, the CRE of the acid-pretreated BMSs was maintained at 99.48-99.52% throughout the pH range of 1-5. Furthermore, the CRE values of the raw and acid-pretreated BMSs were not greatly changed when the temperature was varied from 15 deg. C to 40 deg. C. In addition, the CRE value of the raw BMSs was maintained for 12 cycles of sorption-desorption with a CRE of 98.4% being observed in the final cycle. Finally, when the BMSs were used to treat electroplating wastewater, the removal efficiencies (REs) of the raw BMSs were 99.97%, 98.99% and 87% for Fe, Zn and Cu, respectively, whereas the REs of the acid-pretreated BMSs were 99.98%, 99.43% and 92.13%, respectively. Ion exchange experiments revealed that one of mechanisms for metal sorption by the BMSs from aqueous solution is related to ion exchange, especially between the metal ions in the treated solution and Ca 2+ from BMSs. Infrared absorbance spectra analysis indicated that the acid pretreatment led to occurrence of the groups (i.e. -OH, -NH, C=O and S=O) of

  18. The use of raw and acid-pretreated bivalve mollusk shells to remove metals from aqueous solutions.

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    Liu, Yang; Sun, Changbin; Xu, Jin; Li, Youzhi

    2009-08-30

    Heavy metal removal from industrial wastewater is not only to protect living organisms in the environment but also to conserve resources such as metals and water by enabling their reuse. To overcome the disadvantage of high cost and secondary pollution by the conventional physico-chemical treatment techniques, environmentally benign and low-cost adsorbents are in demand. In this study, the use of raw and acid-pretreated bivalve mollusk shells (BMSs) to remove metals from aqueous solutions with single or mixed metal was evaluated at different BMSs doses, pH and temperatures in batch shaking experiments in laboratory conditions. When the BMSs were used to treat CuSO(4)x5H(2)O solution, the copper sorption capacities of the raw and acid-pretreated BMSs were approximately 38.93 mg/g and 138.95 mg/g, respectively. The copper removal efficiency (CRE) of the raw BMSs became greatly enhanced with increasing initial pH, reaching 99.51% at the initial pH 5. Conversely, the CRE of the acid-pretreated BMSs was maintained at 99.48-99.52% throughout the pH range of 1-5. Furthermore, the CRE values of the raw and acid-pretreated BMSs were not greatly changed when the temperature was varied from 15 degrees C to 40 degrees C. In addition, the CRE value of the raw BMSs was maintained for 12 cycles of sorption-desorption with a CRE of 98.4% being observed in the final cycle. Finally, when the BMSs were used to treat electroplating wastewater, the removal efficiencies (REs) of the raw BMSs were 99.97%, 98.99% and 87% for Fe, Zn and Cu, respectively, whereas the REs of the acid-pretreated BMSs were 99.98%, 99.43% and 92.13%, respectively. Ion exchange experiments revealed that one of mechanisms for metal sorption by the BMSs from aqueous solution is related to ion exchange, especially between the metal ions in the treated solution and Ca(2+) from BMSs. Infrared absorbance spectra analysis indicated that the acid pretreatment led to occurrence of the groups (i.e. -OH, -NH, C=O and S

  19. A critical examination of the possible application of zinc stable isotope ratios in bivalve mollusks and suspended particulate matter to trace zinc pollution in a tropical estuary.

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    Araújo, Daniel; Machado, Wilson; Weiss, Dominik; Mulholland, Daniel S; Boaventura, Geraldo R; Viers, Jerome; Garnier, Jeremie; Dantas, Elton L; Babinski, Marly

    2017-07-01

    The application of zinc (Zn) isotopes in bivalve tissues to identify zinc sources in estuaries was critically assessed. We determined the zinc isotope composition of mollusks (Crassostrea brasiliana and Perna perna) and suspended particulate matter (SPM) in a tropical estuary (Sepetiba Bay, Brazil) historically impacted by metallurgical activities. The zinc isotope systematics of the SPM was in line with mixing of zinc derived from fluvial material and from metallurgical activities. In contrast, source mixing alone cannot account for the isotope ratios observed in the bivalves, which are significantly lighter in the contaminated metallurgical zone (δ 66 Zn JMC  = +0.49 ± 0.06‰, 2σ, n = 3) compared to sampling locations outside (δ 66 Zn JMC  = +0.83 ± 0.10‰, 2σ, n = 22). This observation suggests that additional factors such as speciation, bioavailability and bioaccumulation pathways (via solution or particulate matter) influence the zinc isotope composition of bivalves. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Reconstructing Past Seasonal to Multicentennial-Scale Variability in the NE Atlantic Ocean Using the Long-Lived Marine Bivalve Mollusk Glycymeris glycymeris

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    Reynolds, D. J.; Hall, I. R.; Slater, S. M.; Scourse, J. D.; Halloran, P. R.; Sayer, M. D. J.

    2017-11-01

    The lack of long-term, highly resolved (annual to subannual) and absolutely dated baseline records of marine variability extending beyond the instrumental period (last 50-100 years) hinders our ability to develop a comprehensive understanding of the role the ocean plays in the climate system. Specifically, without such records, it remains difficult to fully quantify the range of natural climate variability mediated by the ocean and to robustly attribute recent changes to anthropogenic or natural drivers. Here we present a 211 year (1799-2010 C.E.; all dates hereafter are Common Era) seawater temperature (SWT) reconstruction from the northeast Atlantic Ocean derived from absolutely dated, annually resolved, oxygen isotope ratios recorded in the shell carbonate (δ18Oshell) of the long-lived marine bivalve mollusk Glycymeris glycymeris. The annual record was calibrated using subannually resolved δ18Oshell values drilled from multiple shells covering the instrumental period. Calibration verification statistics and spatial correlation analyses indicate that the δ18Oshell record contains significant skill at reconstructing Northeast Atlantic Ocean mean summer SWT variability associated with changes in subpolar gyre dynamics and the North Atlantic Current. Reconciling differences between the δ18Oshell data and corresponding growth increment width chronology demonstrates that 68% of the variability in G. glycymeris shell growth can be explained by the combined influence of biological productivity and SWT variability. These data suggest that G. glycymeris can provide seasonal to multicentennial absolutely dated baseline records of past marine variability that will lead to the development of a quantitative understanding of the role the marine environment plays in the global climate system.

  1. 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.

  2. Bioaccumulation of 210Po in common gastropod and bivalve species from the northern Gulf.

    Science.gov (United States)

    Uddin, S; Bebhehani, M

    2014-06-01

    This study sets the baseline for the concentration of the natural-series radionuclide polonium-210 in two species of gastropods and four species of bivalves that are common to the Northern Arabian/Persian Gulf. (210)Po is primarily absorbed from water and via ingestion of detrital material by gastropoda and bivalves. This concentrated (210)Po can then be passed along to the next trophic level of the marine food web. The lowest (210)Po concentration was measured in the gastropod Stomatella auricular (10.36-12.39Bq kg(-1)dry) and the highest in the bivalve Marica marmorata (193.51-215.60Bq kg(-1)dry). The measured concentration factor for these molluscs in the northern Gulf varied between 4.8 and 115×10(3), values very similar to the IAEA recommended value for bivalves and gastropods of 2×10(4). Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Distribution of DTHS3 satellite DNA across 12 bivalve species Eva ...

    Indian Academy of Sciences (India)

    Windows User

    In this work, characterization of DTHS3 satellite DNA was further expanded within the Class. Bivalvia. Monomer variants of DTHS3 satDNA were compared in 12 bivalve species belonging to two different Subclasses, Heterodonta and Pteriomorphia. This satDNA, whose age is estimated to a minimum of 516 Ma, ...

  4. Mollusk communities of the central Congo River shaped by combined effects of barriers, environmental gradients, and species dispersal

    Directory of Open Access Journals (Sweden)

    Oscar Wembo Ndeo

    2017-05-01

    Full Text Available Rapids, falls, and cascades might act as barriers for freshwater species, determining the species community up- and downstream of barriers. However, they affect community composition not only by acting as barriers but also by their influence on environmental gradients. Moreover, the directional dispersal of species along the watercourse might determine community composition. A suitable system to study these differential effects is the Congo River, the world’s second largest river by discharge. The small ‘Upper Congo Rapids’ ecoregion features several rapids known as barrier for fishes. The Wagenia Cataracts at the town of Kisangani constitute the strongest drop of the Congo River and several studies have emphasized its role as barrier for fish distribution. Alternative explanations for this pattern, however, are rarely evaluated. Though mollusks represent a vital component of the macrozoobenthos, with distribution patterns and underlying drivers often distinct from that of fishes, virtually no field surveys of the Congo River have been reported for decades. We collected and determined mollusks of 51 stations, recorded environmental conditions, and generated proxies for directional species dispersal and an indirect barrier effect. Those variables were subjected to distance-based redundancy analyses and variation partitioning in order to test whether the mollusk community compositions are better explained by an individual or combined influence of the direct and indirect effect of the cataract barrier, environmental conditions, and downstream-directed dispersal. Our survey showed an exclusive upstream/downstream distribution for just four out of the 19 species, suggesting a limited barrier effect. We revealed no direct influence of the barrier itself on community composition but of substrate type. However, we found an indirect effect of the barrier through replacing spatially structured communities upstream of the cataract with more uniform

  5. Metals and organotins in multiple bivalve species in a one-off global survey

    DEFF Research Database (Denmark)

    Larsen, Martin Mørk; Strand, Jakob; Christensen, Jan H.

    2011-01-01

    contamination levels on a global scale. Metal concentrations in nine bivalve species were normalised to the Mytilidae family using conversion factors based on cosampled species and literature bioconcentration factors. The lowest metal and tributyltin concentrations were below background assessment...... were low, but not always lower than expected impacted areas. The most contaminated areas were harbours, where especially Copenhagen, St Croix and Sydney, can be considered hotspots of tributyltin as well as a number of metals....

  6. Modiolarca lateralis (Pteryomorphia: Mytilidae: bivalve associated to six species of ascidians from Bocas del Toro, Panama

    Directory of Open Access Journals (Sweden)

    Juan I Cañete

    2013-11-01

    Full Text Available We describe the presence of the bivalve Modiolarca lateralis (Say, 1822 in six tropical ascidians Ascidia curvata, A. sydneiensis, A. panamensis, A. interrupta, Herdmania pallida and Polycarpa spongiabilis collected at depths of 1-3 m on coral reefs, mangrove roots and dock supports in Almirante Bay, Bocas del Toro, Panama (9°18'N, 82°13'W during June-July 2011. Bivalve prevalence varied between 9-30% across species, but was mainly associated with A. panamensis, P. spongiabilis and A. interrupta. Prevalence seems to be influenced by tunic thickness rather than by the ascidian size. Bivalves varied in size (0.6-11 mm shell length, with the smallest individual found in A. sydneiensis. There were only one or two bivalves per ascidians, although a maximum of 18 was found in one A. panamensis. M. lateralis seems to behave similarly to its temperate counterparts: it has a variety of hosts, occurs mainly in the anterior region of the ascidians, and has a variable abundance per host.

  7. Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay.

    Science.gov (United States)

    Praveen Kumar, M K; Shyama, S K; Sonaye, B S; Naik, U Roshini; Kadam, S B; Bipin, P D; D'costa, A; Chaubey, R C

    2014-05-01

    Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of 'Comet assay' for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in both bivalve species. This showed a dose-dependent increase of genetic damage induced in bivalves by EMS as well as gamma radiation. Further, the highest DNA damage was observed at 24h. The damage gradually decreased with time, i.e. was smaller at 48 and 72 h than at 24h post irradiation in both species of bivalves. This may indicate repair of the damaged DNA and/or loss of heavily damaged cells as the post irradiation time advanced. The present study

  8. Proteomic Profiling of Cytosolic Glutathione Transferases from Three Bivalve Species: Corbicula fluminea, Mytilus galloprovincialis and Anodonta cygnea

    Directory of Open Access Journals (Sweden)

    José Carlos Martins

    2014-01-01

    Full Text Available Suspension-feeding bivalves are considered efficient toxin vectors with a relative insensitivity to toxicants compared to other aquatic organisms. This fact highlights the potential role of detoxification enzymes, such as glutathione transferases (GSTs, in this bivalve resistance. Nevertheless, the GST system has not been extensively described in these organisms. In the present study, cytosolic GSTs isoforms (cGST were surveyed in three bivalves with different habitats and life strategies: Corbicula fluminea, Anodonta cygnea and Mytilus galloprovincialis. GSTs were purified by glutathione-agarose affinity chromatography, and the collection of expressed cGST classes of each bivalve were identified using a proteomic approach. All the purified extracts were also characterized kinetically. Results reveal variations in cGST subunits collection (diversity and properties between the three tested bivalves. Using proteomics, four pi-class and two sigma-class GST subunits were identified in M. galloprovincialis. C. fluminea also yielded four pi-class and one sigma-class GST subunits. For A. cygnea, two mu-class and one pi-class GST subunits were identified, these being the first record of GSTs from these freshwater mussels. The affinity purified extracts also show differences regarding enzymatic behavior among species. The variations found in cGST collection and kinetics might justify diverse selective advantages for each bivalve organism.

  9. Mollusks: how are they arranged in the rocky intertidal zone?

    Directory of Open Access Journals (Sweden)

    Débora R. A. Veras

    2013-06-01

    Full Text Available Mollusks occupy different kinds of environments, including the intertidal zone. The present study investigated the spatial distribution of mollusks on beach rocks of the intertidal zone of Pacheco Beach in the state of Ceará, Brazil. Sampling occurred from August 2006 to September 2007. Across two transects, six samples of 0.25 m² were collected monthly in gaps of 30 m (0 m, 30 m, 60 m, 90 m, 120 m and 150 m. The mollusks were counted in field, and samples of sediment and algae were taken for further analysis. A total of 74,515 individuals were found and classified into 67 species, 52 genera and 39 families. Gastropods were predominant, corresponding to 73.1% of the species, followed by bivalves (22.4% and chitons (4.5%. Caecum ryssotitum de Folin, 1867 was the most abundant taxon, representing 68.8% of total specimen findings. In general, species were mostly found in Middle Littoral zone (samples 60 m and 90 m, suggesting that the greater number of microenvironments available in this area may contribute to establishment and survival.

  10. Near infra-red spectroscopy quantitative modelling of bivalve protein, lipid and glycogen composition using single-species versus multi-species calibration and validation sets

    Science.gov (United States)

    Bartlett, Jill K.; Maher, William A.; Purss, Matthew B. J.

    2018-03-01

    Near infrared spectroscopy (NIRS) quantitative modelling was used to measure the protein, lipid and glycogen composition of five marine bivalve species (Saccostrea glomerata, Ostrea angasi, Crassostrea gigas, Mytilus galloprovincialis and Anadara trapezia) from multiple locations and seasons. Predictive models were produced for each component using individual species and aggregated sample populations for the three oyster species (S. glomerata, O. angasi and C. gigas) and for all five bivalve species. Whole animal tissues were freeze dried, ground to > 20 μm and scanned by NIRS. Protein, lipid and glycogen composition were determined by traditional chemical analyses and calibration models developed to allow rapid NIRS-measurement of these components in the five bivalve species. Calibration modelling was performed using wavelet selection, genetic algorithms and partial least squares analysis. Model quality was assessed using RPIQ and RMESP. For protein composition, single species model results had RPIQ values between 2.4 and 3.5 and RMSEP between 8.6 and 18%, the three oyster model had an RPIQ of 2.6 and an RMSEP of 10.8% and the five bivalve species had an RPIQ of 3.6 and RMSEP of 8.7% respectively. For lipid composition, single species models achieved RPIQ values between 2.9 and 5.3 with RMSEP between 9.1 and 11.2%, the oyster model had an RPIQ of 3.6 and RMSEP of 6.8 and the five bivalve model had an RPIQ of 5.2 and RMSEP of 6.8% respectively. For glycogen composition, the single species models had RPIQs between 3.8 and 18.9 with RMSEP between 3.5 and 9.2%, the oyster model had an RPIQ of 5.5 and RMSEP of 7.1% and the five bivalve model had an RPIQ of 4 and RMSEP of 7.6% respectively. Comparison between individual species models and aggregated models for three oyster species and five bivalve species for each component indicate that aggregating data from like species produces high quality models with robust and reliable quantitative application. The benefit of

  11. Immunotoxicity of nanoparticle nTiO2 to a commercial marine bivalve species, Tegillarca granosa.

    Science.gov (United States)

    Shi, Wei; Han, Yu; Guo, Cheng; Zhao, Xinguo; Liu, Saixi; Su, Wenhao; Zha, Shanjie; Wang, Yichen; Liu, Guangxu

    2017-07-01

    The increasing production and extensive application of nanoparticles (NPs) inevitably leads to increased release of NPs into the marine environment and therefore poses a potential threat to marine organisms, especially the sessile benthic bivalves. However, the impacts of NPs on the immunity of commercial and ecological important bivalve species, Tegillarca granosa, still remain unknown to date. In addition, the molecular mechanism of the immunotoxicity of NPs still remains unclear in marine invertebrates. Therefore, the immunotoxicity of nTiO 2 exposure to T. granosa at environmental realistic concentrations was investigated in the present study. Results obtained showed that the total number, phagocytic activity, and red granulocytes ratio of the haemocytes were significantly reduced after 30 days nTiO 2 exposures at the concentrations of 10 and 100 μg/L. Furthermore, the expressions of genes encoding Pattern Recognition Receptors (PPRs) and downstream immune-related molecules were significantly down-regulated by nTiO 2 exposures, indicating a reduced sensitivity to pathogen challenges. In conclusion, evident immunotoxicity of nTiO 2 to T. granosa at environmental realistic concentrations was detected by the present study. In addition, the gene expression analysis suggests that the PRRs (both TLRs and RIG1 investigated) may be the molecules for NPs recognition in marine invertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay

    International Nuclear Information System (INIS)

    Praveen Kumar, M.K.; Shyama, S.K.; Sonaye, B.S.; Naik, U Roshini; Kadam, S.B.; Bipin, P.D.; D’costa, A.; Chaubey, R.C.

    2014-01-01

    Highlights: • Possible genotoxic effect of accidental exposure of aquatic fauna to γ radiation. • Relative sensitivity of bivalves to γ radiation is also analyzed using comet assay. • γ radiation induced significant genetic damage in both the species of bivalves. • P. malabarica and M. casta exhibited a similar level of sensitivity to γ radiation. • Comet assay may be used as a biomarker for the environmental biomonitoring. - Abstract: Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of ‘Comet assay’ for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in

  13. Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay

    Energy Technology Data Exchange (ETDEWEB)

    Praveen Kumar, M.K., E-mail: here.praveen@gmail.com [Department of Zoology, Goa University, Goa 403206 (India); Shyama, S.K., E-mail: skshyama@gmail.com [Department of Zoology, Goa University, Goa 403206 (India); Sonaye, B.S. [Department of Radiation Oncology, Goa Medical College, Goa (India); Naik, U Roshini; Kadam, S.B.; Bipin, P.D.; D’costa, A. [Department of Zoology, Goa University, Goa 403206 (India); Chaubey, R.C. [Radiation Biology and Health Science Division, Bhabha Atomic Research Centre, Mumbai (India)

    2014-05-01

    Highlights: • Possible genotoxic effect of accidental exposure of aquatic fauna to γ radiation. • Relative sensitivity of bivalves to γ radiation is also analyzed using comet assay. • γ radiation induced significant genetic damage in both the species of bivalves. • P. malabarica and M. casta exhibited a similar level of sensitivity to γ radiation. • Comet assay may be used as a biomarker for the environmental biomonitoring. - Abstract: Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of ‘Comet assay’ for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in

  14. Geochemical aspects of Meretrix casta (bivalve) shells of Vellar ...

    African Journals Online (AJOL)

    SAM

    2014-05-14

    May 14, 2014 ... The bivalve mollusk, Meretrix casta shells are abundant in the Vellar estuary along the East .... the Shervarayan hills of Salem District in Tamil Nadu, India. .... coast of Peninsular Malaysia and its potential as biomaterial for use.

  15. The Shell of the Invasive Bivalve Species Dreissena polymorpha: Biochemical, Elemental and Textural Investigations.

    Directory of Open Access Journals (Sweden)

    Françoise Immel

    Full Text Available The zebra mussel Dreissena polymorpha is a well-established invasive model organism. Although extensively used in environmental sciences, virtually nothing is known of the molecular process of its shell calcification. By describing the microstructure, geochemistry and biochemistry/proteomics of the shell, the present study aims at promoting this species as a model organism in biomineralization studies, in order to establish a bridge with ecotoxicology, while sketching evolutionary conclusions. The shell of D. polymorpha exhibits the classical crossed-lamellar/complex crossed lamellar combination found in several heterodont bivalves, in addition to an external thin layer, the characteristics of which differ from what was described in earlier publication. We show that the shell selectively concentrates some heavy metals, in particular uranium, which predisposes D. polymorpha to local bioremediation of this pollutant. We establish the biochemical signature of the shell matrix, demonstrating that it interacts with the in vitro precipitation of calcium carbonate and inhibits calcium carbonate crystal formation, but these two properties are not strongly expressed. This matrix, although overall weakly glycosylated, contains a set of putatively calcium-binding proteins and a set of acidic sulphated proteins. 2D-gels reveal more than fifty proteins, twenty of which we identify by MS-MS analysis. We tentatively link the shell protein profile of D. polymorpha and the peculiar recent evolution of this invasive species of Ponto-Caspian origin, which has spread all across Europe in the last three centuries.

  16. Comparative in vitro study on free radical scavenging potential of selected bivalve species

    Digital Repository Service at National Institute of Oceanography (India)

    Shenai-Tirodkar, P.S.; Pawar, R.T.; Jagtap, T.G.

    Bivalves such as, Crassostrea spp., Meretrix casta, Placuna placenta and Polymesoda erosa are largely consumed as edible seafood. It forms natural source of nutrition in coastal and worldwide population. Free radical scavenging activities...

  17. [Ecological studies on mollusk populations of medical and veterinary relevance existing in La Coca farm].

    Science.gov (United States)

    Wong Sarmiento, Lin; Vázquez Perera, Antonio A; Quesada Martínez, Maritza; Sánchez Noda, Jorge; Hevia Jiménez, Yosvania; Fuentes Leyva, Joaquín; Ramos Pérez, Ramón

    2010-01-01

    ecological studies were carried out on mollusk populations of medical and veterinary importance with emphasis on Fasciola hepatica intermediary hosts species. to determine the relative abundance of populations and the possible use of some species as biological control agents against F. hepatica intermediary hosts. a total of 13 freshwater bodies were sampled during March and November, 2008 using Capture by effort unit method to capture the mollusks thirteen mollusk species (12 gastropods and 1 bivalve) were found after sampling. The relative abundance of species varied in different types of habitat. The intermediary host species of fascioliasis were dominant in two sites. Fossaria cubensis was dominant in Canal de la Entrada despite the presence of Melanoides tuberculata. The specie Pseudosuccinea columella was more abundant in Los Mangos. In La Presa del Matadero y Las Palmas despite the presence of these species, the prevailing ones were Physa acuta and some planorbids. the sites where intermediary hosts of Fasciola hepatica predominated were identified through data on the distribution and relative abundance. In some sites Melanoides tuberculata was present and acted as a biological control agent but it did not in others. Therefore, an evaluation on using a different thiarid would be useful to control these species.

  18. Chemometrics methods for the investigation of methylmercury and total mercury contamination in mollusks samples collected from coastal sites along the Chinese Bohai Sea.

    Science.gov (United States)

    Yawei, Wang; Lina, Liang; Jianbo, Shi; Guibin, Jiang

    2005-06-01

    The development and application of chemometrics methods, principal component analysis (PCA), cluster analysis and correlation analysis for the determination of methylmercury (MeHg) and total mecury (HgT) in gastropod and bivalve species collected from eight coastal sites along the Chinese Bohai Sea are described. HgT is directly determined by atomic fluorescence spectrometry (AFS), while MeHg is measured by a laboratory established high performance liquid chromatography-atomic fluorescence spectrometry system (HPLC-AFS). One-way ANOVA and cluster analysis indicated that the bioaccumulation of Rap to accumulate Hg was significantly (P<0.05) different from other mollusks. Correlation analysis shows that there is linear relationship between MeHg and HgT in mollusks samples collected from coastal sites along the Chinese Bohai Sea, while in mollusks samples collected from Hongqiao market in Beijing City, there is not any linear relationship.

  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. First records of Freshwater Bivalves of Ilha Grande National Park, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Flávio Henrique Ragonha

    2014-03-01

    Full Text Available The Ilha Grande National Park, Paraná, Brazil, is located in the Upper Paraná River and has characteristics typical of a floodplains. This protected area includes lagoons connected and disconnected to the Paraná River, although the latter also connect during periods of high water level, thus composing a heterogeneous group of lacustrine environments. The enormous potential the flora and fauna diversities are still little known to the region, as can be seen through benthic invertebrates, inclunding bivalves mollusks. The granulometric composition of these floodplain lagoons was formed mainly by mud and very fine sand. Furthermore, organic matter composition was predominantly of fine particulate. The other abiotic factors differed from lagoons located within the island of the park to those located in the left margin of Paraná River. The results demonstrated the importance of abiotic factors such as the physical composition of granulometric texture, organic matter and macrophyte banks, to the establishment of bivalves in these floodplain lagoons. We recorded bivalves of Pisidium (native, Diplodon (native, and Corbicula (invasive. The highest values of Diplodon sp. density were observed at São João/C lake, for Pisidium sterkianum (Pilsbry, 1897 at São João/M lake, and to Jatobá/C lagoon with high density of invasive species Corbicula fluminea (Müller, 1774. This study to obtain conduct the first records of freshwater bivalves in floodplains lagoon in the Ilha Grande National Park, and provides contributions to better understanding the ecology of these mollusks. The recording of native species in the region of Upper Paraná River floodplain after a lomg period without new records, demonstrated the importance of protecting the lagoons of the Ilha Grande National Park as they can be a possible refuge to some species of native freshwater bivalves.

  1. Chemosynthetic bacteria found in bivalve species from mud volcanoes of the Gulf of Cadiz.

    Science.gov (United States)

    Rodrigues, Clara F; Webster, Gordon; Cunha, Marina R; Duperron, Sébastien; Weightman, Andrew J

    2010-09-01

    As in other cold seeps, the dominant bivalves in mud volcanoes (MV) from the Gulf of Cadiz are macrofauna belonging to the families Solemyidae (Acharax sp., Petrasma sp.), Lucinidae (Lucinoma sp.), Thyasiridae (Thyasira vulcolutre) and Mytilidae (Bathymodiolus mauritanicus). The delta(13)C values measured in solemyid, lucinid and thyasirid specimens support the hypothesis of thiotrophic nutrition, whereas isotopic signatures of B. mauritanicus suggest methanotrophic nutrition. The indication by stable isotope analysis that chemosynthetic bacteria make a substantial contribution to the nutrition of the bivalves led us to investigate their associated bacteria and their phylogenetic relationships based on comparative 16S rRNA gene sequence analysis. PCR-denaturing gradient gel electrophoresis analysis and cloning of bacterial 16S rRNA-encoding genes confirmed the presence of sulfide-oxidizing symbionts within gill tissues of many of the studied specimens. Phylogenetic analysis of bacterial 16S rRNA gene sequences demonstrated that most bacteria were related to known sulfide-oxidizing endosymbionts found in other deep-sea chemosynthetic environments, with the co-occurrence of methane-oxidizing symbionts in Bathymodiolus specimens. This study confirms the presence of several chemosynthetic bivalves in the Gulf of Cadiz and further highlights the importance of sulfide- and methane-oxidizing symbionts in the trophic ecology of macrobenthic communities in MV.

  2. Can bivalve veligers escape feeding currents of adult bivalves?

    NARCIS (Netherlands)

    Troost, K.; Veldhuizen, R.; Stamhuis, E.J.; Wolff, W.J.

    2008-01-01

    While the stock of introduced Pacific oysters (Crassostrea gigas) increased in the Oosterschelde estuary (SW Netherlands), so did the filtration pressure of all bivalve species together. In the same period, stocks of native bivalves declined slightly. The expansion of Pacific oysters in Dutch

  3. Chemosymbiotic bivalves from the mud volcanoes of the Gulf of Cadiz, NE Atlantic, with descriptions of new species of Solemyidae, Lucinidae and Vesicomyidae.

    Science.gov (United States)

    Olive, Graham; Rodrigues, Clara F; Cunha, Marina R

    2011-01-01

    The chemosymbiotic bivalves collected from the mud volcanoes of the Gulf of Cadiz are reviewed. Of the thirteen species closely associated with chemosynthetic settings two Solemyidae, Solemya (Petrasma) elarraichensissp. n. and Acharax gadiraesp. n., one Lucinidae, Lucinoma asapheussp. n., and one Vesicomyidae, Isorropodon megadesmussp. n. are described and compared to close relatives of their respective families. The biodiversity and distribution of the chemosymbiotic bivalves in the Gulf of Cadiz are discussed and compared to the available information from other cold seeps in the Eastern Atlantic and Mediterranean. Although there is considerable similarity at the genus level between seep/mud volcano fields in the Eastern Atlantic and Mediterranean, there is little overlap at the species level. This indicates a high degree of endemism within chemosymbiotic bivalve assemblages.

  4. Recirculation nursery systems for bivalves

    NARCIS (Netherlands)

    Kamermans, P.; Blanco Garcia, A.; Joaquim, Sandra; Matias, Domitilia; Magnesen, Thorolf; Nicolas, J.; Petten, Bruno; Robert, Rene

    2016-01-01

    n order to increase production of bivalves in hatcheries and nurseries, the development of new technology and its integration into commercial bivalve hatcheries is important. Recirculation aquaculture systems (RASs) have several advantages: high densities of the species can be cultured resulting in

  5. Boreholes on three bivalve species found on the sand beach at Sagot Cape, Baengnyeongdo, Korea

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    Dal-Yong Kong

    2017-12-01

    Full Text Available Circular to subcircular boreholes were found on the surfaces of three different bivalve shells (Mactra chinensis, Felaniella usta, and Nuttallia japonica that were pushed onto the sand beach at Sagot Cape, Baengnyeongdo, Korea. The boreholes are characterized by beveled holes that are parabolic in cross section. The boreholes are classified into the ichnospecies Oichnus paraboloides, probably drilled by a naticid gastropod Glossaulax didyma didyma living in the Baengnyeong tidal flat. In the case of Mactrashells, boreholes are observed more or less evenly on left and right valves, and 96% of boreholes are located on the umbo. This may suggest that the life position of the Baengnyeong bivalves did not dictate the preference of G. didyma didyma in the Baengnyeong tidal flat ecosystem. The clustered distribution of the boreholes in the umbo area indicates a strong site selectivity for boreholes that is quite a common phenomenon in many naticid gastropods. Keywords: Baengnyeongdo, Mactra chinensis, Naticid gastropods, Oichnus paraboloides, Prey–predator interactions

  6. Evaluation of tropical water sources and mollusks in southern Brazil using microbiological, biochemical, and chemical parameters.

    Science.gov (United States)

    Souza, Doris Sobral Marques; Ramos, Ana Paula Dores; Nunes, Fabrício Flores; Moresco, Vanessa; Taniguchi, Satie; Leal, Diego Averaldo Guiguet; Sasaki, Silvio Tarou; Bícego, Márcia Caruso; Montone, Rosalinda Carmela; Durigan, Maurício; Teixeira, Adriano Luiz; Pilotto, Mariana Rangel; Delfino, Nicésio; Franco, Regina Maura Bueno; Melo, Cláudio Manoel Rodrigues de; Bainy, Afonso Celso Dias; Barardi, Célia Regina Monte

    2012-02-01

    Florianópolis, a city located in the Santa Catarina State in southern Brazil, is the national leading producer of bivalve mollusks. The quality of bivalve mollusks is closely related to the sanitary conditions of surrounding waters where they are cultivated. Presently, cultivation areas receive large amounts of effluents derived mainly from treated and non-treated domestic, rural, and urban sewage. This contributes to the contamination of mollusks with trace metals, pesticides, other organic compounds, and human pathogens such as viruses, bacteria, and protozoan. The aim of this study was to perform a thorough diagnosis of the shellfish growing areas in Florianópolis, on the coast of Santa Catarina. The contamination levels of seawater, sediments, and oysters were evaluated for their microbiological, biochemical, and chemical parameters at five sea sites in Florianópolis, namely three regular oyster cultivation areas (Sites 1, 2, and oyster supplier), a polluted site (Site 3), and a heavily polluted site (Site 4). Samples were evaluated at day zero and after 14 days. Seawater and sediment samples were collected just once, at the end of the experiment. Antioxidant defenses, which may occur in contaminated environments in response to the increased production of reactive oxygen species (ROS) by organisms, were analyzed in oysters, as well as organic compounds (in oysters and sediment samples) and microbiological contamination (in oysters and seawater samples). The results showed the presence of the following contaminants: fecal coliforms in seawater samples (four sites), human adenovirus (all sites), human noroviruses GI and GII (two sites), Hepatitis A viruses (one site), JC Polyomavirus in an oyster sample from the oyster supplier, Giardia duodenalis cysts, and Cryptosporidium sp oocysts (one site). Among organochlorine pesticides, only DDT (dichlorodiphenyltrichloroethane) and HCH (hexachlorocyclohexane) were detected in some sediment and oysters samples in very

  7. Light and scanning electron microscopic studies of Unionicola tetrafurcatus (Acari: Unionicolidae) infecting four freshwater bivalve species with referring to histopathological effect on its hosts.

    Science.gov (United States)

    Abdel-Gaber, Rewaida; Fol, Mona; Al Quraishy, Saleh

    2018-05-08

    Water mites of the genus Unionicola are the most common symbionts of freshwater bivalves. During the current investigation, a total of 120 live freshwater mussels [Corbicula fluminea (Veneroida), Coelatura aegyptiaca (Unionoidea) Mutela rostrata and Chambardia rubens (Mutelidae)], were collected from 2 localities in Tura (Helwan Governorate) and El Kanater (Qaluobiya Governorate), Egypt. Only 3 of the 4 bivalve species listed are considered freshwater bivalves (members of Unionoidea). While, C. fluminea belong to the family Cyrenidae within Veneroida. The collected mussels were dissected and examined for the presence of unionicolid mites. It was found that 30.83% (37/120) were infected with a single mite species Unionicola tetrafurcatus (Unionicolidae). The highest prevalence was observed during the summer with 83.33% (25/30), whereas the least was observed in autumn, i.e. 33.33% (10/30). Mites were recovered from the gills, gonads, and visceral mass of mussel hosts. gills of host mussels were the primary site of oviposition for unionicola mites. Smaller bivalves in size had significantly greater numbers of mites than larger ones in size. Numbers of mites per host species was variable and the highest prevalence level of 83.33% (25/30) was recorded in C. fluminea, while, the lowest one of 16.66% (5/30) was found in C. rubens. Morphological and morphometric characterizations of mites revealed some differences between the present species and other related Unionicola. Histopathological responses of host mussels to the eggs, larvae, and cuticular remnants of U. tetrafurcatus were also studied. Therefore, the present study demonstrated that freshwater bivalves have a new host and locality records for infection with U. tetrafurcatus. Future studies are recommended to include advanced molecular characteristics for these mites.

  8. Availability of mollusks as ''biological monitor'' to monitoring of the long-lived silver isotope released into the marine environment

    International Nuclear Information System (INIS)

    Watabe, Teruhisa; Yokosuka, Setsuko; Kurosawa, Akiko

    2003-01-01

    The species of mollusks often show unique physiological properties and the elemental composition different from those of fishes as observed in the blood constituents. Much higher concentrations of metal elements such as cupper, zinc, cadmium and so on have been reported for squids and bivalves than other organisms. The present study reports the results of gamma spectrometry analyses for two species of gastropods (Buccinum isaotakii and Buccinum striatissimum), one of the important species of mollusks, inhabiting on the sea bottom at the depth of some hundreds meters off the coast and for squids (Todarodes pacificus, Thysanoteuthis rhombus, etc.) landed at several fishing ports in Japan. It would be noted that 108m Ag (half-life time: 418.21y) was commonly detected in the viscera of both gastropods and squids usually at the radioactivity level higher than 137 Cs. A discussion on the distribution and inventory of 108m Ag in the water column was attempted on the basis of the data on its specific activity, which was derived from the data on stable silver for the samples of interest obtained by analyses using ICP-AES. Special attention was directed to the efficacy and applicability of the mollusks having an affinity for this element to the environmental monitoring as indices. (author)

  9. Carbon isotopes in mollusk shell carbonates

    Science.gov (United States)

    McConnaughey, Ted A.; Gillikin, David Paul

    2008-10-01

    Mollusk shells contain many isotopic clues about calcification physiology and environmental conditions at the time of shell formation. In this review, we use both published and unpublished data to discuss carbon isotopes in both bivalve and gastropod shell carbonates. Land snails construct their shells mainly from respired CO2, and shell δ13C reflects the local mix of C3 and C4 plants consumed. Shell δ13C is typically >10‰ heavier than diet, probably because respiratory gas exchange discards CO2, and retains the isotopically heavier HCO3 -. Respired CO2 contributes less to the shells of aquatic mollusks, because CO2/O2 ratios are usually higher in water than in air, leading to more replacement of respired CO2 by environmental CO2. Fluid exchange with the environment also brings additional dissolved inorganic carbon (DIC) into the calcification site. Shell δ13C is typically a few ‰ lower than ambient DIC, and often decreases with age. Shell δ13C retains clues about processes such as ecosystem metabolism and estuarine mixing. Ca2+ ATPase-based models of calcification physiology developed for corals and algae likely apply to mollusks, too, but lower pH and carbonic anhydrase at the calcification site probably suppress kinetic isotope effects. Carbon isotopes in biogenic carbonates are clearly complex, but cautious interpretation can provide a wealth of information, especially after vital effects are better understood.

  10. Mollusks in the Mangrove Rehabilitation Areas in Western Pangasinan, Philippines

    Directory of Open Access Journals (Sweden)

    Rene B. De Vera

    2015-12-01

    Full Text Available Mollusks are predominantly found inmangrove ecosystems. Nowadays, these are declining due to habitat disturbances. This study was conducted in Western, Pangasinan, with mangrove rehabilitation projects under Community Based Forest Management Agreement. Four mangrove rehabilitation areas were looked into: Pilar and Victory, Bolinao; and Awile and Tori-tori, Anda, Pangasinan. Purposive sampling was done in selecting the mangrove rehabilitation areas. Ten percent sampling of the areas using the belt transect quadrat method was employed. Diversity, dominance , richness and evenness indices for mollusks were determined. Mann Whitney test, Student’s t-test and Kruskal Wallis test were used. A total of fourteen kinds of mollusks species were identified. The species were Tectusfenestratus (fenestrate top, Terebraliasulcata (Sulcate swamp perith, Haliotisovinagemelin (oval abalone, Neritaplanospiraanton (flat spired nerite, Clithionoualensis(dubious nerite, Fasciolaria trapezium (trapezium horse conch, Nasarriuspullus (ribbed dog whelk, Trochusmaculatus (maculated top, Rhinoclavisvertagus (Common vertagus , Telescopium telescopium (Telescope Snail, Isognomonephippium (saddle tree oyster Crassostriairedali (slipper oyster, Strombuslabiatus (Plicate conch and Polymesodaexpansa (Yellowish mangrove clam. The highest mollusks species diversity and richness indeces were observed in Victory, Bolinao. Mollusks species dominance and evenness indeces were highest in Pilar, Bolinao and Tori-tori, Anda, respectively. The study revealed a significant difference in the probability of gathering mollusks species in the four mangrove rehabilitation areas. It is recommended that fisherfolkand coastal communities be educated about the need for mollusks conservation and habitat protection. It is expected that this study may provide light to future research on mangrove fauna particularly mollusks in Pangasinan.

  11. Archaeozoology of marine mollusks from Sambaqui da Tarioba, Rio das Ostras, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Rosa C. C. L. de Souza

    2010-06-01

    Full Text Available A reference inventory of prehistoric marine mollusks from the Rio das Ostras region was created based on an excavation carried out at the Sambaqui da Tarioba shellmound. Patterns of richness and biogeography were studied, and the representativeness of bivalve and gastropod diversities found at this archaeological site were inferred. A total of 47 taxa belonging to 28 families, most of which from unconsolidated substrates, was identified. The shellmound species composition does not differ from the present-day composition. All recorded species are characteristic of a wide transition zone between the south of the states of Espírito Santo (21°S and Rio Grande do Sul (32°S. Thus, the data show little evidence of evolution in the composition, richness,and biodiversity distribution patterns of mollusks in the Rio das Ostras region. Likewise, a reconstitution of the paleoenvironment from the functional characteristics of the shellmound species indicates that the locality's geomorphology and climate remained largely unchanged in the last 4,000 years BP.

  12. Fossil Cenozoic crassatelline bivalves from Peru: New species and generic insights

    Directory of Open Access Journals (Sweden)

    Thomas J. DeVries

    2016-08-01

    Full Text Available Discoveries of new fossil Cenozoic crassatellines in Peru provide a new phylogenetic perspective on “large” Neogene genera, in which four lineages are considered to have arisen independently from different Paleogene Crassatella ancestors. Latest Oligocene and early Miocene species of the new genus Tilicrassatella gen. nov.―T. ponderosa, T. torrens sp. nov., and T. sanmartini sp. nov. from the East Pisco Basin―probably evolved from the late Eocene species, Crassatella rafaeli sp. nov., which itself differed in significant respects from slightly older species of the East Pisco Basin, C. neorhynchus and C. pedroi sp. nov. The paciphilic genus, Hybolophus, is raised to full generic status. Added to its ranks are the East Pisco Miocene species H. maleficae sp. nov., H. terrestris sp. nov., and the oldest species of the genus, the late Eocene or Oligocene H. disenum sp. nov. from the Talara Basin of northern Peru. Kalolophus gen. nov., encompassing circum-Caribbean fossil species, the extant species, K. speciosus, and the trans-isthmus species, K. antillarum, appears to have evolved from the early Oligocene Floridian species, Crassatella portelli sp. nov. The genus Marvacrassatella is a western Atlantic Miocene lineage most likely descended from Kalolophus. The genus Eucrassatella is restricted to Australian and New Zealand taxa. The Eocene New Zealand species, Spissatella media, is transferred to Eucrassatella and deemed a candidate for the most recent common ancestor of younger Eucrassatella and all Spissatella species. In the southern Pacific Ocean, the circum-Caribbean region, and tropical western America, crassatelline lineages developed one or more of the following characters: large resilifers, smooth ventral margins, and an extended left anterior cardinal tooth. Some of these late Paleogene convergent character changes might have countered increased shear forces exerted on the crassatelline valves while burrowing into finer-grained and

  13. Redox-Stratified Bacterial Communities in Sediments Associated with Multiple Lucinid Bivalve Species: Implications for Symbiosis in Changing Coastal Habitats

    Science.gov (United States)

    Paterson, A. T.; Fortier, C. M.; Long, B.; Kokesh, B. S.; Lim, S. J.; Campbell, B. J.; Anderson, L. C.; Engel, A. S.

    2017-12-01

    Lucinids, chemosymbiotic marine bivalves, occupy strong redox gradient habitats, including the rhizosphere of coastal seagrass beds and mangrove forests in subtropical to tropical ecosystems. Lucinids and their sulfide-oxidizing gammaproteobacterial endosymbionts, which are acquired from the environment, provide a critical ecosystem service by removing toxic reduced sulfur compounds from the surrounding environment, and lucinids may be an important food source to economically valuable fisheries. The habitats of Phacoides pectinatus, Stewartia floridana, Codakia orbicularis, Ctena orbiculata, and Lucina pensylvanica lucinids in Florida and San Salvador in The Bahamas were evaluated in comprehensive malacological, microbiological, and geochemical surveys. Vegetation cover included different seagrass species or calcareous green macroalgae. All sites were variably affected by anthropogenic activities, as evidenced by visible prop scars in seagrass beds, grain size distributions atypical of low energy environments (i.e., artificial fill or dredge material from nearby channels), and high levels of pyrogenic hydrocarbon compounds in sediment indicative of urbanization impact. Where present, lucinid population densities frequently exceeded 2000 individuals per cubic meter, and were typically more abundant underlying seagrass compared to unvegetated, bare sand. Dissolved oxygen and sulfide levels varied from where lucinids were recovered. The sediment bacterial communities from classified 16S rRNA gene sequences indicated that the diversity of putative anaerobic groups increased with sediment depth, but putative aerobes, including of Gammaproteobacteria related to the lucinid endosymbionts, decreased with depth. Where multiple seagrass species co-occurred, retrieved bacterial community compositions correlated to overlying seagrass species, but diversity differed from bare sand patches, including among putative free-living endosymbiont groups. As such, continued sea

  14. Source and impact of lead contamination on δ-aminolevulinic acid dehydratase activity in several marine bivalve species along the Gulf of Cadiz

    International Nuclear Information System (INIS)

    Company, R.; Serafim, A.; Lopes, B.; Cravo, A.; Kalman, J.; Riba, I.; DelValls, T.A.; Blasco, J.; Delgado, J.; Sarmiento, A.M.; Nieto, J.M.; Shepherd, T.J.; Nowell, G.; Bebianno, M.J.

    2011-01-01

    Coastal areas and estuaries are particularly sensitive to metal contamination from anthropogenic sources and in the last few decades the study of space-time distribution and variation of metals has been extensively researched. The Gulf of Cadiz is no exception, with several rivers draining one of the largest concentrations of sulphide deposits in the world, the Iberian Pyrite Belt (IPB). Of these rivers, the Guadiana, one of the most important in the Iberian Peninsula, together with smaller rivers like the Tinto and Odiel, delivers a very high metal load to the adjacent coastal areas. The purpose of this work was to study the source and impact of lead (Pb) drained from historical or active mining areas in the IPB on the activity of a Pb inhibited enzyme (δ-aminolevulinic acid dehydratase, ALAD) in several bivalve species along the Gulf of Cadiz. Seven marine species (Chamelea gallina, Mactra corallina, Donax trunculus, Cerastoderma edule, Mytilus galloprovincialis, Scrobicularia plana and Crassostrea angulata) were collected at 12 sites from Mazagon, near the mouth of the rivers Tinto and Odiel (Spain), to Cacela Velha (Ria Formosa lagoon system, Portugal). Lead concentrations, ALAD activity and lead isotope ratios ( 206 Pb/ 204 Pb, 207 Pb/ 204 Pb and 208 Pb/ 204 Pb) were determined in the whole soft tissues. The highest Pb concentrations were determined in S. plana (3.50 ± 1.09 μg g -1 Pb d.w.) and D. trunculus (1.95 ± 0.10 μg g -1 Pb d.w.), while M. galloprovincialis and C. angulata showed the lowest Pb levels ( -1 Pb d.w.). In general, ALAD activity is negatively correlated with total Pb concentration. However this relationship is species dependent (e.g. linear for C. gallina ALAD = -0.36[Pb] + 0.79; r = 0.837; or exponential for M. galloprovincialis ALAD = 2.48e -8.3[Pb] ; r = 0.911). This indicates that ALAD activity has considerable potential as a biomarker of Pb and moreover, in marine bivalve species with different feeding habits. Lead isotope data

  15. 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.

  16. Caracterização físico-química e microestrutural de conchas de moluscos bivalves provenientes de cultivos da região litorânea da ilha de Santa Catarina Physical chemistry and micro structural characterization of shells of bivalve mollusks from sea farmer around the Santa Catarina island

    Directory of Open Access Journals (Sweden)

    Denyo Silva

    2010-01-01

    Full Text Available Samples of shells of oysters and mussels from sea farm around the Santa Catarina Island in south Brazil were collected and analyzed by DRX, FRX, SEM, CHN-S, FTIR, TG, AAS/Flame and AAS /GF. The results showed that the crystalline structure of mussel's shells is mainly formed by aragonite and the oyster's shells by calcite. The calcium percentage in both shells species was in the range of 33 to 35% and also 850 and 1200 mg/kg of strontium was detected in the shells of oysters and mussels, respectively. The content of organic matter was larger in the mussel's shells and the thermal degradation of both shells species occurred by three events at different temperatures from 250 to 830 ºC.

  17. Source and impact of lead contamination on {delta}-aminolevulinic acid dehydratase activity in several marine bivalve species along the Gulf of Cadiz

    Energy Technology Data Exchange (ETDEWEB)

    Company, R.; Serafim, A.; Lopes, B.; Cravo, A. [CIMA, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Kalman, J.; Riba, I.; DelValls, T.A. [Catedra UNESCO/UNITWIN/WiCop, Department of Physical-Chemistry, Faculty Marine and Environmental Sciences, University of Cadiz, 11510 Puerto Real, Cadiz (Spain); Blasco, J. [Instituto Ciencias Marinas Andalucia (CSIC), Campus Rio San Pedro, 11510 Puerto Real, Cadiz (Spain); Delgado, J. [Department of Geology, University of Huelva, Avda Fuerzas Armadas s/n, 21071 Huelva (Spain); Sarmiento, A.M. [Catedra UNESCO/UNITWIN/WiCop, Department of Physical-Chemistry, Faculty Marine and Environmental Sciences, University of Cadiz, 11510 Puerto Real, Cadiz (Spain); Department of Geology, University of Huelva, Avda Fuerzas Armadas s/n, 21071 Huelva (Spain); Nieto, J.M. [Department of Geology, University of Huelva, Avda Fuerzas Armadas s/n, 21071 Huelva (Spain); Shepherd, T.J.; Nowell, G. [Department of Earth Sciences, University of Durham, Science Laboratories, Durham DH1 3LE (United Kingdom); Bebianno, M.J., E-mail: mbebian@ualg.pt [CIMA, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)

    2011-01-17

    Coastal areas and estuaries are particularly sensitive to metal contamination from anthropogenic sources and in the last few decades the study of space-time distribution and variation of metals has been extensively researched. The Gulf of Cadiz is no exception, with several rivers draining one of the largest concentrations of sulphide deposits in the world, the Iberian Pyrite Belt (IPB). Of these rivers, the Guadiana, one of the most important in the Iberian Peninsula, together with smaller rivers like the Tinto and Odiel, delivers a very high metal load to the adjacent coastal areas. The purpose of this work was to study the source and impact of lead (Pb) drained from historical or active mining areas in the IPB on the activity of a Pb inhibited enzyme ({delta}-aminolevulinic acid dehydratase, ALAD) in several bivalve species along the Gulf of Cadiz. Seven marine species (Chamelea gallina, Mactra corallina, Donax trunculus, Cerastoderma edule, Mytilus galloprovincialis, Scrobicularia plana and Crassostrea angulata) were collected at 12 sites from Mazagon, near the mouth of the rivers Tinto and Odiel (Spain), to Cacela Velha (Ria Formosa lagoon system, Portugal). Lead concentrations, ALAD activity and lead isotope ratios ({sup 206}Pb/{sup 204}Pb, {sup 207}Pb/{sup 204}Pb and {sup 208}Pb/{sup 204}Pb) were determined in the whole soft tissues. The highest Pb concentrations were determined in S. plana (3.50 {+-} 1.09 {mu}g g{sup -1} Pb d.w.) and D. trunculus (1.95 {+-} 0.10 {mu}g g{sup -1} Pb d.w.), while M. galloprovincialis and C. angulata showed the lowest Pb levels (<0.38 {mu}g g{sup -1} Pb d.w.). In general, ALAD activity is negatively correlated with total Pb concentration. However this relationship is species dependent (e.g. linear for C. gallina ALAD = -0.36[Pb] + 0.79; r = 0.837; or exponential for M. galloprovincialis ALAD = 2.48e{sup -8.3[Pb]}; r = 0.911). This indicates that ALAD activity has considerable potential as a biomarker of Pb and moreover, in

  18. Galeommatid bivalves from Phuket, Thailand

    DEFF Research Database (Denmark)

    Lützen, Jørgen; Nielsen, Claus

    2005-01-01

    Twenty-seven species of galeommatid bivalves from six genera have been collected at intertidal reef flats near Phuket Marine Biological Center, Thailand (Andaman Sea, Indian Ocean). Fourteen of the species are new to science and a new genus (Nudiscintilla gen. nov.) has been established. The spec......Twenty-seven species of galeommatid bivalves from six genera have been collected at intertidal reef flats near Phuket Marine Biological Center, Thailand (Andaman Sea, Indian Ocean). Fourteen of the species are new to science and a new genus (Nudiscintilla gen. nov.) has been established...... crustacean, the remainder hide under shale, rocks and coral blocks, often in small intra- or interspecific family flocks. The behaviour was also noted for some of the species. It is presumed that galeommatid species go through a lengthy planktonic phase....

  19. Chemometrics methods for the investigation of methylmercury and total mercury contamination in mollusks samples collected from coastal sites along the Chinese Bohai Sea

    International Nuclear Information System (INIS)

    Wang Yawei; Liang Lina; Shi Jianbo; Jiang Guibin

    2005-01-01

    The development and application of chemometrics methods, principal component analysis (PCA), cluster analysis and correlation analysis for the determination of methylmercury (MeHg) and total mercury (HgT) in gastropod and bivalve species collected from eight coastal sites along the Chinese Bohai Sea are described. HgT is directly determined by atomic fluorescence spectrometry (AFS), while MeHg is measured by a laboratory established high performance liquid chromatography-atomic fluorescence spectrometry system (HPLC-AFS). One-way ANOVA and cluster analysis indicated that the bioaccumulation of Rap to accumulate Hg was significantly (P<0.05) different from other mollusks. Correlation analysis shows that there is linear relationship between MeHg and HgT in mollusks samples collected from coastal sites along the Chinese Bohai Sea, while in mollusks samples collected from Hongqiao market in Beijing City, there is not any linear relationship. - Rapana venosa might be used as a potential biomonitor for Hg pollution in the Bohai Sea, China

  20. Biomonitoring on Integrated Multi-Thropic Aquaculture (IMTA) activities using macrobenthic mollusks on Tembelas Island, Kepulauan Riau Province

    Science.gov (United States)

    Abyan Syuja’, M.; Putro, Sapto P.; Muhammad, Fuad

    2018-05-01

    Macrobenthic mollusks are considered a good aquatic bioindicator for environmental biomonitoring. This study was conducted in Tembelas Island, Karimun District, Kepulauan Riau Province, at 103°29’47’ - 103°29’90’ BT and 0.991°16’63’ - 0.989°06’37’ LS. The objective was to compare the quality of water and sediment at Integrated Multitrophic Aquaculture (IMTA) sites, monocultural sites and reference sites using the community structure of mollusks, and to assess the potential of mollusks as bioindicator. The research was conducted in June and October of 2016. Data of abiotic parameters included the composition of sediment substrate and DO, pH, salinity, temperature and turbidity. The sampling procedure was performed with the use of an Ekman Grab. The animals obtained were 1 mm size-sieved and were fixed using 10% formalin for further analysis. In total there were 49 species and 2 classes obtained (Gastropods and Bivalves). The most prevalent genus were Costoanachis sp (Fam. Collumbellidae) and Anodontia sp (Fam. Lucinidae). The values of outcomes from indices used were considered low, ranging from 1.34 to 2.54 for diversity (H’), from 0.86 to 0.96 for evenness, and from 0.11 to 0.31 for dominance (C). Further analysis consisting of a multivariate approach and graphical methods of cluster analysis and Non- Metric Multidimensional Scaling (NMDS) ordination showed differences between the assemblages in the aquacultural areas and the reference area. However, the tendency of grouping the stations between IMTA and monocultural sites did not occur, implying both sites have relatively similar structures of macrobenthic mollusks. Based on the data obtained, sediment composition at the KJABB IMTA, monocultural areas and the reference area were dominated by silt, with the highest value being 92.06% found in the KJABB IMTA area. Clay, silt and nitrogen levels were the abiotic factors influencing structure of macrobenthic mollusks (BIO-ENV-Primer 6.1.5; r = 0.571).

  1. Marine mollusks as bio concentrators of uranium and plutonium

    International Nuclear Information System (INIS)

    Ordonez R, E.; Almazan T, M. G.; Escalante G, D. C.

    2017-09-01

    The sudden presence of certain radionuclides in the marine environment has been of global concern and has raised concerns about the nature and abundance of these, in an attempt to establish dispersion patterns from their discharge points. In the particular case of our country, there are few data on the presence and concentration of alpha emitters, such as uranium and plutonium in the littorals and due to this fact there is a need to establish their reference levels in some specific points of the Mexican littoral. This work thus raises the study of part of the biota that grows and develops in sites near the sampling points. Is known that bivalve mollusks are natural bio-concentrators due to their capacity to absorb some metals dissolved in water, being able to find contaminating metals in their soft bodies, but they also accumulate large quantities when they generate their shells from dissolved carbonates that are complex with uranium and plutonium. The shells of the mollusks were studied to determine the physicochemical characteristics of their shells and the U and Pu were also separated by means of radiochemical techniques, being then electrodeposited in steel discs and evaluated by means of alpha spectroscopy. The results of the methodology prototype are presented to determine the U and Pu dispersed in the littoral by means of the analysis of some mollusks of the zone. (Author)

  2. The inventory of mollusc species and its potent on seagrass bed in Kei Kecil Islands, Southeast Moluccas

    Directory of Open Access Journals (Sweden)

    AGUS KUSNADI

    2008-10-01

    Full Text Available Inventory of mollusk species and its potential on sea grass bed in Kei Kecil islands, Southeast Moluccas have been conducted by using quadrate-transect line method. The study was carried out in February-August 2007. There were 103 species of mollusk observed, 80 species belong to gastropods and 23 belong to bivalves. From the total species, 72 of them were reported as the potential species and the others still unknown. Most of potential group was used as food resources (55 species and other species were potential as decoration, souvenir, ornament, and accessories (31 species. Some species were potential for building material, knife tool, barter tool and bioactive compounds. The top shells (Trochus niloticus, the giant clams (Tridacna spp. and Hippopus hippopus and the abalone (Haliotis spp. were the major trading commodities for shellfish fisheries.

  3. Invasion of the striped mollusks

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    Introduced to this country only five years ago, the prolific zebra mussel has infested the Great Lakes and has already begun to move into fresh waters beyond the region. Dense populations in utility water systems have caused serious problems, reducing plant efficiency and blocking lines used for cooling and fire fighting. Experts say the striped mollusk has the potential to become the industry's worst biological problem, possibly affecting 70% of US power plants. While it appears that the invader is here to stay, EPRI and others continue to develop and refine techniques to control mussel growth. This article describes how the mollusk got here, reviews the problems it can cause and what is being done to mitigate the problems and control the growth and spread of the mollusk.

  4. 19 CFR 12.26 - Importations of wild animals, fish, amphibians, reptiles, mollusks, and crustaceans; prohibited...

    Science.gov (United States)

    2010-04-01

    ..., reptiles, mollusks, and crustaceans; prohibited and endangered and threatened species; designated ports of..., Birds, and Insects § 12.26 Importations of wild animals, fish, amphibians, reptiles, mollusks, and... crustacea), amphibians, reptiles, or the offspring or eggs of any of the foregoing which the Secretary of...

  5. Interspecific variability of endocrine disruption and oxidative stress in two bivalve species from the Ria Formosa Lagoon (south coast of Portugal

    Directory of Open Access Journals (Sweden)

    Catarina Pereira

    2013-01-01

    Full Text Available Estuaries are highly productive ecosystems that have been increasingly affected by anthropogenic activities. In this study, the presence of endocrine disrupting compounds (EDCs and their relation to oxidative stress were assessed in two bivalve species (mussels Mytilus galloprovincialis and clams Ruditapes decussatus from the Ria Formosa Lagoon (south Portugal. We applied the alkali-labile phosphate (ALP assay to determine vitellogenin-like protein levels, and the lipid peroxidation (LPO method to assess oxidative damage. Mussels and clams exhibited the same pattern of ALP concentrations, with no differences between genders and higher levels in winter. R. decussatus showed higher ALP values than M. galloprovincialis, possibly associated with a stronger responsiveness of clams to EDCs or due to the influence of the reproductive cycle. Mussels exhibited a more evident seasonal effect for LPO, indicating that these organisms are more influenced by seasonal fluctuations in the water column compared to the sediment-associated clams. Both species appear to be under the influence of EDC exposure (which could induce Vg-like protein synthesis and oxidative stressors (leading to lipid peroxidation in the Ria Formosa Lagoon, particularly in winter, reflecting the presence of different contaminants in Ria Formosa and environmental changes, as well as complex interactions between them.

  6. Late Miocene mollusks from the Queen Charlotte Islands, British Columbia, Canada

    Science.gov (United States)

    Addicott, Warren O.

    1978-01-01

    A fauna of bivalve mollusks, scattered gastropods, and an echinoid from exposures of the Skonun Formation in the northeastern part of Graham Island is indicative of an early late Miocene age and correlation with the provincial Wishkahan Stage. The molluscan assemblages are from the upper 600 of the 1800-m-thick marine and nonmarine formation, which appears to be entirely of late Miocene age. The Skonun Formation is the strandline fa.cies of marginal marine and nonmarine deposits of the northwestern part of the Queen Charlotte basin, a Nieogene embayment paralleling the modern mainland coast. The molluscan fauna and associated lignite beds are known from a few widely scattered outcrops; they are indicative of alternating marine and nonmarine to brackish-water environments in the upper part of the formation. The Skonun fauna occurs near the northern boundary of the Pacific Northwest Neogene molluscan province. It is the only marine Neogene molluscan fauna known from the British Columbia coast. The fauna has strong taxonomic ties with the fauna of the Empire Formation of southwestern Oregon and has several species in common with the upper Miocene of the Lituya district, southeastern Alaska, implying that these three faunas are coeval.

  7. Microplastics in commercial bivalves from China

    International Nuclear Information System (INIS)

    Li, Jiana; Yang, Dongqi; Li, Lan; Jabeen, Khalida; Shi, Huahong

    2015-01-01

    We investigated microplastic pollution in 9 commercial bivalves from a fishery market in China. Multiple types of microplastics, including fibers, fragments and pellets, occurred in the tissue of all bivalves. The number of total microplastics varied from 2.1 to 10.5 items/g and from 4.3 to 57.2 items/individual for bivalves. Scapharca subcrenata contained on average 10.5 items/g and exhibited the highest levels of microplastics by weight. Fibers were the most common microplastics and consisted of more than half of the total microplastics in each of the 8 species. In Alectryonella plicatula, pellets accounted for 60% of the total microplastics. The most common size class was less than 250 μm and accounted for 33–84% of the total microplastics calculated by species. Our results suggest that microplastic pollution was widespread and exhibited a relatively high level in commercial bivalves from China. More intensive investigations on microplastics should be conducted in seafood. - Highlights: • Fiber, fragment and pellet microplastics were found in 9 bivalves. • The abundance of microplastics was 2.1–10.5 items/g. • Fibers were the most common microplastics. • The most common size class of microplastics was less than 250 μm. • Microplastic pollution was widespread and serious in commercial bivalves. - Fiber, fragment and pellet microplastics in the range of 2.1–10.5 items/g were observed in 9 species of commercially popular bivalves from China.

  8. A survey of the mammals, lizards and mollusks

    NARCIS (Netherlands)

    NN,

    1940-01-01

    This annotated list of the mammals, lizards and mollusks of the Leeward Group, is based on author’s collection and therefore includes additional mainland-records of the island-species. As a rule a short commentary is given only as a guide to the adopted nomenclature and classification, in case of

  9. Cadmium distribution in coastal sediments and mollusks of the US

    International Nuclear Information System (INIS)

    Apeti, Dennis A.; Lauenstein, Gunnar G.; Riedel, Gerhardt F.

    2009-01-01

    Cadmium (Cd) concentrations in the coastal United States were assessed using the National Status and Trends (NS and T) Mussel Watch dataset, which is based on the analysis of sediments and bivalves collected from 280 sites since 1986. Using the 1997 sediment data, Pearson correlation (r = 0.44, p < 0.0001) suggested that Cd distributions in sediment can, be to some extent, explained by the proximity of sites to population centers. The 2003 tissue data indicated that 'high' Cd concentrations (greater than 5.6 μg/g dry weights [dw] for mussel and 5.4 μg/g dw for oysters) were related to salinity along the East and Gulf coasts. Along the West coast, however, these 'high' sites appeared to be related to upwelling phenomenon. Additionally, sedimentary diagenesis was found to be the most likely explanation of why sediment and mollusk Cd content were not well correlated.

  10. Anodontites trapesialis (LAMARCK, 1819: a bivalve parasite of freshwater fishes / Anodontites trapesialis (LAMARCK, 1819: um bivalve parasito de peixes de água doce

    Directory of Open Access Journals (Sweden)

    Ângela Teresa Silva-Souza

    2008-08-01

    Full Text Available The bivalve mollusk Anodontites trapesialis has been indicated as an alternative source for aquaculture because it is considered a food of good nutritional value with a protein content close to that of fish. Its shells can be utilized as fertilizer and mixed to the food of domestic animals, and the nacre can be used to manufacture buttons and crafts. However, the larvae of A. trapesialis, which are the lasidium type, are obligatory parasites of freshwater fishes, and the introduction of this bivalve in fish farm tanks have caused trouble and losses for producers. Nothing is known, however, about their development in these environments. On the other hand, it should be pointed out that A. trapesialis is on Brazil’s list of species threatened with extinction. This article provides a compilation of information present in the literature, offering a detailed review, with the aim of presenting a general panorama of what is known about Anodontites trapesialis and its larval parasitism of fishes.O molusco bivalve, Anodontites trapesialis, tem sido indicado como fonte alternativa para a aqüicultura, por ser considerado um alimento de bom valor nutricional com um conteúdo protéico próximo ao do pescado. Suas conchas podem ser utilizadas como fertilizantes calcáreos e ser agregadas a alimentos de animais domésticos e o nácar pode ser utilizado para fabricar botões e artesanatos. No entanto, as larvas de A. trapesialis, que são do tipo lasidium, são parasitas obrigatórias de peixes de água doce e a introdução desse bivalve em tanques de piscicultura tem causado transtornos e prejuízos aos produtores. Nada se conhece, porém, sobre o seu desenvolvimento nesses ambientes. Por outro lado, ressalta-se que A. trapesialis consta da lista brasileira de espécies ameaçadas de extinção. No presente artigo são compiladas as informações presentes na literatura, em uma revisão detalhada, com o objetivo de apresentar o panorama geral do

  11. Complete sequences of the highly rearranged molluscan mitochondrial genomes of the scaphopod graptacme eborea and the bivalve mytilus edulis

    Energy Technology Data Exchange (ETDEWEB)

    Boore, Jeffrey L.; Medina, Monica; Rosenberg, Lewis A.

    2004-01-31

    We have determined the complete sequence of the mitochondrial genome of the scaphopod mollusk Graptacme eborea (Conrad, 1846) (14,492 nts) and completed the sequence of the mitochondrial genome of the bivalve mollusk Mytilus edulis Linnaeus, 1758 (16,740 nts). (The name Graptacme eborea is a revision of the species formerly known as Dentalium eboreum.) G. eborea mtDNA contains the 37 genes that are typically found and has the genes divided about evenly between the two strands, but M. edulis contains an extra trnM and is missing atp8, and has all genes on the same strand. Each has a highly rearranged gene order relative to each other and to all other studied mtDNAs. G. eborea mtDNA has almost no strand skew, but the coding strand of M. edulis mtDNA is very rich in G and T. This is reflected in differential codon usage patterns and even in amino acid compositions. G. eborea mtDNA has fewer non-coding nucleotides than any other mtDNA studied to date, with the largest non-coding region being only 24 nt long. Phylogenetic analysis using 2,420 aligned amino acid positions of concatenated proteins weakly supports an association of the scaphopod with gastropods to the exclusion of Bivalvia, Cephalopoda, and Polyplacophora, but is generally unable to convincingly resolve the relationships among major groups of the Lophotrochozoa, in contrast to the good resolution seen for several other major metazoan groups.

  12. Mollusks of Candomblé: symbolic and ritualistic importance.

    Science.gov (United States)

    Léo Neto, Nivaldo A; Voeks, Robert A; Dias, Thelma L P; Alves, Rômulo R N

    2012-03-15

    Human societies utilize mollusks for myriad material and spiritual ends. An example of their use in a religious context is found in Brazil's African-derived belief systems. Candomblé, an Afro-Brazilian religion introduced during the 18th-19th centuries by enslaved Yoruba, includes various magical and liturgical uses of mollusks. This work inventoried the species utilized by adherents and to analyzed their symbolic and magical context. Data were obtained from Candomblé temples in two cities in the northeast of Brazil-Caruaru, in the state of Pernambuco, and Campina Grande, in the state of Paraíba. Questionnaires administered to eleven adepts revealed that at least nineteen mollusk species are being used. Shells from Monetaria moneta, M. annulus and Erosaria caputserpentis were cited by all of the interviewees. Three uses stood out: divination (jogo de búzios); utilization as ritual objects; and employment as sacrificial offerings (Igbin or Boi-de-Oxalá). The jogo de búzios (shell toss), employed in West Africa, Brazil and Cuba, is of fundamental importance to the cult, representing the means by which the faithful enter in contact with the divinities (Orixás) and consult people's futures (Odu). The utilization of mollusks in Candomblé is strongly influenced by ancient Yoruba myths (Itãs) which, having survived enslavement and generations of captive labor, continue to guide the lives of Brazil's African Diaspora.

  13. Mollusks of Candomblé: symbolic and ritualistic importance

    Directory of Open Access Journals (Sweden)

    Léo Neto Nivaldo A

    2012-03-01

    Full Text Available Abstract Human societies utilize mollusks for myriad material and spiritual ends. An example of their use in a religious context is found in Brazil's African-derived belief systems. Candomblé, an Afro-Brazilian religion introduced during the 18th-19th centuries by enslaved Yoruba, includes various magical and liturgical uses of mollusks. This work inventoried the species utilized by adherents and to analyzed their symbolic and magical context. Data were obtained from Candomblé temples in two cities in the northeast of Brazil-Caruaru, in the state of Pernambuco, and Campina Grande, in the state of Paraíba. Questionnaires administered to eleven adepts revealed that at least nineteen mollusk species are being used. Shells from Monetaria moneta, M. annulus and Erosaria caputserpentis were cited by all of the interviewees. Three uses stood out: divination (jogo de búzios; utilization as ritual objects; and employment as sacrificial offerings (Igbin or Boi-de-Oxalá. The jogo de búzios (shell toss, employed in West Africa, Brazil and Cuba, is of fundamental importance to the cult, representing the means by which the faithful enter in contact with the divinities (Orixás and consult people's futures (Odu. The utilization of mollusks in Candomblé is strongly influenced by ancient Yoruba myths (Itãs which, having survived enslavement and generations of captive labor, continue to guide the lives of Brazil's African Diaspora.

  14. Terrestrial mollusk records from Chinese loess sequences and changes in the East Asian monsoonal environment

    Science.gov (United States)

    Wu, Naiqin; Li, Fengjiang; Rousseau, Denis-Didier

    2018-04-01

    The terrestrial mollusk fossils found in Chinese loess strata have been studied for over one hundred years. However, the greatest progress in these studies has been made only in the last two decades. In this paper, we review the advancements, advantages and limitations of terrestrial mollusk studies in Chinese loess deposits. Improvements in research methods and approaches have allowed the extraction of more detailed paleoenvironmental and paleoclimatic information from mollusk assemblages. The broadened research scope and content have yielded many new findings and results. The mollusk record has thus become one of the most important proxies in the paleoenvironmental and paleoclimatic reconstruction of loess-paleosol sequences in China. The greatest progress in the studies of terrestrial mollusks in Chinese loess sequences can be summarized as follows: (1) modern mollusk assemblages can be classified into four ecotypes, based on their temperature and humidity requirements, including eurytopic, semi-aridiphilous and sub-humidiphilous, cold-aridiphilous, and thermo-humidiphilous types; (2) Quaternary mollusk assemblages can be modified into the following three ecological types: glacial loess, interglacial paleosol, and interstadial weakly-developed paleosol assemblages; (3) mollusk records successfully reveal long-term climatic and environmental changes reflective of the history of East Asian monsoonal variations since the Late Cenozoic, and the succession of mollusk species also indicate short-term environmental changes such as millennial climate variability during Last Glacial Maximum and unstable climatic fluctuations during glacial and interglacial periods; and (4) more recently, new analytical approaches have offered increased research potential in areas such as paleotemperature reconstruction using the isotopic compositions of modern and fossil mollusk shells, combined with higher accuracy 14C dating of Quaternary loess deposits, which will greatly improve

  15. Oxidative stress in mollusks Biomphalaria Glabrata exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luanna R.S.; Augusto, Ricielle L.; Siqueira, Williams N.; Luna Filho, Ricardo L.C.; Pereira, Dewson R.; França, Elvis J.; Silva, Edvane B.; Melo, Ana M.M.A., E-mail: luannaribeiro_lua@hotmail.com, E-mail: williams.wns@gmail.com, E-mail: ejfranca@gmail.com, E-mail: edvborges@yahoo.com, E-mail: luannaribeiro_lua@hotmail.com, E-mail: williams.wns@gmail.com, E-mail: ricardolclf@hotmail.com, E-mail: dewson.rocha@gmail.com, E-mail: s, E-mail: amdemelo@hotmail.com, E-mail: ricielleaugusto@gmail.com, E-mail: williams.wns@gmail.com, E-mail: ejfranca@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2017-11-01

    Ionizing radiation can cause biological changes in different organisms such as mollusks from Biomphalaria glabrata species, in which alterations could be observed in the reproductive system of the specimens, prejudicing fertility and fecundity. As the changes may occur due to the lipid peroxidation caused by the action of free radicals on the gonads, the objective of this work was to evaluate the oxidative damage caused by the exposure of B. glabrata mollusks to different doses of gamma radiation. In addition, efforts were carried out to standardize a sensitive and low-cost technique for detecting negative effects caused by high doses of ionizing radiation. For this, each mollusk group (n = 10) was submitted to 0 (control), 10, 15, 20 and 25 Gy (Gammacell- {sup 60}Co, dose rate 3.532 kGy/h). The TBARS method was applied for the quantification of lipid peroxidation of the gonads of the mollusks after 24 and 48 h. ANOVA, followed by the mean comparison (Tukey) at the 5% of significance level, indicated high concentrations of TBARS in the gonads after 24 h. Otherwise, after 48 h, differences for TBARS concentrations were not significant at the 95% confidence level, determining that the action of free radicals from ionizing radiation on cell membranes mainly occurred within 24 h after irradiation. (author)

  16. Oxidative stress in mollusks Biomphalaria Glabrata exposed to gamma radiation

    International Nuclear Information System (INIS)

    Silva, Luanna R.S.; Augusto, Ricielle L.; Siqueira, Williams N.; Luna Filho, Ricardo L.C.; Pereira, Dewson R.; França, Elvis J.; Silva, Edvane B.; Melo, Ana M.M.A.

    2017-01-01

    Ionizing radiation can cause biological changes in different organisms such as mollusks from Biomphalaria glabrata species, in which alterations could be observed in the reproductive system of the specimens, prejudicing fertility and fecundity. As the changes may occur due to the lipid peroxidation caused by the action of free radicals on the gonads, the objective of this work was to evaluate the oxidative damage caused by the exposure of B. glabrata mollusks to different doses of gamma radiation. In addition, efforts were carried out to standardize a sensitive and low-cost technique for detecting negative effects caused by high doses of ionizing radiation. For this, each mollusk group (n = 10) was submitted to 0 (control), 10, 15, 20 and 25 Gy (Gammacell- "6"0Co, dose rate 3.532 kGy/h). The TBARS method was applied for the quantification of lipid peroxidation of the gonads of the mollusks after 24 and 48 h. ANOVA, followed by the mean comparison (Tukey) at the 5% of significance level, indicated high concentrations of TBARS in the gonads after 24 h. Otherwise, after 48 h, differences for TBARS concentrations were not significant at the 95% confidence level, determining that the action of free radicals from ionizing radiation on cell membranes mainly occurred within 24 h after irradiation. (author)

  17. Invasion of the striped mollusks

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Introduced to this country only five years ago, the prolific zebra mussel has infested the Great Lakes and has already begun to move into fresh waters beyond the region. Dense populations in utility water systems have caused serious problems, reducing plant efficiency and blocking lines used for cooling and fire fighting. Experts say the striped mollusk has the potential to become the industry's worst biological problem, possibly affecting 70% of US power plants. While it appears that the invader is here to stay, EPRI and others continue to develop and refine techniques to control mussel growth

  18. Microplastics in commercial bivalves from China.

    Science.gov (United States)

    Li, Jiana; Yang, Dongqi; Li, Lan; Jabeen, Khalida; Shi, Huahong

    2015-12-01

    We investigated microplastic pollution in 9 commercial bivalves from a fishery market in China. Multiple types of microplastics, including fibers, fragments and pellets, occurred in the tissue of all bivalves. The number of total microplastics varied from 2.1 to 10.5 items/g and from 4.3 to 57.2 items/individual for bivalves. Scapharca subcrenata contained on average 10.5 items/g and exhibited the highest levels of microplastics by weight. Fibers were the most common microplastics and consisted of more than half of the total microplastics in each of the 8 species. In Alectryonella plicatula, pellets accounted for 60% of the total microplastics. The most common size class was less than 250 μm and accounted for 33-84% of the total microplastics calculated by species. Our results suggest that microplastic pollution was widespread and exhibited a relatively high level in commercial bivalves from China. More intensive investigations on microplastics should be conducted in seafood. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Genetical structure of populations of modelling species of terrestrial mollusks in conditions of the urbanized landscape on example Сhondrula tridens Müll (Gastropoda, Pulmonata

    Directory of Open Access Journals (Sweden)

    Eduard A Snegin

    2011-06-01

    Full Text Available On the basis of the analysis of the morphological and genetical variability revealed by a method of gel-electrophoresis of proteins in PAAG, the state of gene pools of populations of modeling species Сhondrula tridens Müll (threedens snail in conditions of the urbanized forest-steppe landscape of the south of Mid-Russia Upland is investigated. In the majority of the investigated bunches authentic decrease of a level of heterozygosity and the decrease of an allelic diversification caused, both is fixed by natural historical factors, and factors of an anthropogenic parentage. The genetic-automatic processes in populations are considered and vectors of natural selection are defined. Calculation of effective number of researched bunches is spent.

  20. Artificially evolved functional shell morphology of burrowing bivalves

    DEFF Research Database (Denmark)

    Germann, D. P.; Schatz, W.; Hotz, Peter Eggenberger

    2014-01-01

    The morphological evolution of bivalves is documented by a rich fossil record. It is believed that the shell shape and surface sculpture play an important role for the burrowing performance of endobenthic species. While detailed morphometric studies of bivalve shells have been done...... dimensional (3D) objects, the first ever artificial evolution of a physical bivalve shell was performed. The result was a vertically flattened shell occupying only the top sediment layers. Insufficient control of the sediment was the major limitation of the setup and restricted the significance of the results...

  1. Paleoecological insights from fossil freshwater mollusks of the Kanapoi Formation (Omo-Turkana Basin, Kenya).

    Science.gov (United States)

    Van Bocxlaer, Bert

    2017-09-13

    The Early Pliocene Kanapoi Formation of the Omo-Turkana Basin consists of two fluvial/deltaic sedimentary sequences with an intermediate lacustrine sequence that was deposited in Paleolake Lonyumun, the earliest large lake in the basin. Overall, the geology and vertebrate paleontology of the Kanapoi Formation are well studied, but its freshwater mollusks, despite being a major component of the benthic ecosystem, have not been subjected to in-depth study. Here I present the first treatment of these mollusks, which have been retrieved mainly from the lacustrine but also from the upper fluvial sediments, with a focus on paleoecological implications. Overall, the freshwater mollusk fauna is reasonably diverse and contains the gastropods Bellamya (Viviparidae), Melanoides (Thiaridae), Cleopatra (Paludomidae) and Gabbiella (Bithyniidae), as well as the unionoid bivalves Coelatura, Pseudobovaria (Unionidae), Aspatharia, Iridina (Iridinidae) and Etheria (Etheriidae). Material is typically recrystallized and lithified and its taphonomy suggests deposition in a system with intermediate energy, such as a beach, with post-depositional deformation and abrasion. The mollusk assemblage is indicative of perennial, fresh and well-oxygenated waters in the Kanapoi region. It suggests that Paleolake Lonyumun had largely open shores with limited vegetation and that swampy or ephemeral backwaters were rare. Overall, these findings support earlier paleoecological interpretations based on the fish assemblage of Paleolake Lonyumun at Kanapoi. Moreover, mollusk assemblages from this lake are very similar across the Omo-Turkana Basin (Nachukui, Usno, Mursi and Koobi Fora Formations) suggesting that the lacustrine paleoecological conditions found in the Kanapoi Formation existed throughout the basin. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Polonium-210 in marine bivalves inhabiting a wedge bank region, South India

    International Nuclear Information System (INIS)

    Feroz Khan, M.; Godwin Wesley, S.; Rajan, M.P.

    2013-01-01

    Determination of background radiation dose-rate is important in the process of assessing risks to the environment from exposure to living organisms both in terms of deriving the incremental dose-rate and as a point of reference for evaluating the significance of the exposure level. In the present study, 210 Po was quantified in two species of bivalve mollusks commonly available from so called a 'wedge bank region' of southern tip of India. Based on the activity concentration in media and in the whole body, an external and internal dose rate assessment to green mussel Perna viridis and brown mussel Perna indica due to 210 Po was derived using ERICA assessment tool. The samples were collected at the intertidal region along the wedge bank region of southern tip of India during 2009 to 2010. The measurement contributes to a better knowledge of these elements, since no data exists in this region. 5-10 g of each tissue sample was wet-digested using 70% concentrated HNO 3 followed by the addition of 40% H 2 O 2 along with 20 8Po tracer (0.2 Bq). The normality of the data set was checked using Lilliefors test (ne''50) and potential outliers, if any, were tested using Walsh's test (n>60). Using the measured 210 Po activity in molluscs, sediments and seawater, dose assessment was performed using the Tier 2 ERICA environment dose assessment tool 1.0

  3. Inactivation of Vibrio cholerae O1 El Tor inoculated into Peruvian ''choro'' mussels (Aulacomya ater) and two species of clams (Argopecten purpuratus and Gari solida) using medium-dose irradiation

    International Nuclear Information System (INIS)

    Torres, Z.; Bernuy, B.; Kahn, G.; Zapata, G.; Vivanco, M.; Guzman, E.; Leon, R.

    2001-01-01

    The radiation decimal reduction dose (D 10 ) for Vibrio cholerae O1 biotype El Tor inoculated through the natural feeding system into three species of bivalve mollusks from the Peruvian Pacific coast: ''choro'' mussels (Aulacome ater), ''abanico'' clams (Argopecten purpuratus), and common clams (Gari solida), was determined in vivo. The D 10 value obtained in vivo was 0.14 kGy in all mollusks tested. Concurrent studies conducted to determine the potential use of irradiation to extend the microbiological shelf-life of the mollusks during post-irradiation storage at 0-1 deg. C indicated that a dose of 1.0 kGy was optimal for choro mussels and abanico clams, whereas 2.0 kGy produced the best results when treating common clams. Shelf-life extension thus achieved was 31 days for choro mussels, 16 days for abanico clams, and 21 days for common clams. Non-irradiated control samples of all mollusks spoiled after 17 days of refrigerated storage. There were no significant (p<.05) adverse effects from the application of the optimal radiation treatments on the sensory characteristics (i.e. appearance, odor, flavor, and texture) of the mollusks. Total volatile basic nitrogen (VBN) and pH values were examined for use as indexes of seafood freshness. (author)

  4. Risk Assessment of Organochlorines in Mollusk from the Mediterranean and Red Sea Coasts of Egypt.

    Science.gov (United States)

    El Nemr, Ahmed; El-Said, Ghada F; Khaled, Azza

    2016-04-01

    Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) residues were studied in different mollusk species from the Egyptian Mediterranean and Red Sea coasts. The average levels of OCPs in mollusks comprised chlordanes, dieldrins, total endrin, endosulfan compounds, and methoxychlor (DECEM), dichlorodiphenyltrichloroethanes (DDTs), and, hexachlorocyclohexanes (HCHs). The averages of HCHs, DDTs, and polychlorinated biphenyls (PCBs) in mollusks from the Mediterranean Sea were 1.13±1.21, 1.30±1.27, and 1.40±0.93 ng/g, respectively; from the Red Sea, they were 0.62±0.90, 1.77±1.82, and 6.44±5.05 ng/g, respectively. The analysis of HCHs, DDTs, and PCBs in mollusks indicates a new usage of lindane, PCB congeners, and the input of technical HCH and aged DDT. The data showed that the Red Sea Coast was more affected by PCBs congeners than the Mediterranean Sea Coast, which may be attributed to the different activities along the two coastal areas. Mollusks in the Mediterranean Sea had higher dieldrins, total endrin, endosulfan compounds, and methoxychlor contents than those in the Red Sea. Interestingly, HCHs, DDTs, and PCBs levels were lower than those recommended for Swedish Food Regulation and U.S. Food and Drug Administration, which means that mollusks from these two coastal areas are safe as food.

  5. The Roles of Macrobenthic Mollusks as Bioindicator in Response to Environmental Disturbance : Cumulative k-dominance curves and bubble plots ordination approaches

    Science.gov (United States)

    Putro, Sapto P.; Muhammad, Fuad; Aininnur, Amalia; Widowati; Suhartana

    2017-02-01

    Floating net cage is one of the aquaculture practice operated in Indonesian coastal areas that has been growing rapidly over the last two decades. This study is aimed to assess the roles of macrobenthic mollusks as bioindicator in response to environmental disturbance caused by fish farming activities, and compare the samples within the locations using graphical methods. The research was done at the floating net cage fish farming area in the Awerange Gulf, South Sulawesi, Indonesia at the coordinates between 79°0500‧- 79°1500‧ LS and 953°1500‧- 953°2000‧ BT, at the polyculture and reference areas, which was located 1 km away from farming area. Sampling period was conducted between October 2014 to June 2015. The sediment samples were taken from the two locations with two sampling time and three replicates using Van Veen Grab for biotic and abiotic assessment. Mollusks as biotic parameter were fixed using 4% formalin solution and were preserved using 70% ethanol solution after 1mm mesh size. The macrobenthic mollusks were found as many as 15 species consisting of 14 families and 2 classes (gastropods and bivalves). Based on cumulative k-dominance analysis projected on each station, the line of station K3T1 (reference area; first sampling time) and KJAB P3T2 (polyculture area; second sampling time) are located below others curves, indicating the highest evenness and diversity compared to the other stations, whereas station K2T1 (reference area; first sampling time) and K3T2 (polyculture area, second sampling time) are located on the top, indicate the lowest value of evenness and diversity. Based on the bubble plots NMDS ordination, the four dominant taxa/species did not clearly show involvement in driving/shifting the ordinate position of station on the graph, except T. agilis. However, the two species showed involvement in driving/shifting the ordinate position of two stations of the reference areas from the first sampling time by Rynoclavis sordidula

  6. Anatomical study on Myoforceps aristatus, an invasive boring bivalve in S.E. Brazilian coast (Mytilidae

    Directory of Open Access Journals (Sweden)

    Luiz Ricardo L. Simone

    2006-01-01

    Full Text Available The bivalve Myoforceps aristatus (Dillwyn, 1817, also known as Lithophaga aristata, have been recently collected in the coasts of Rio de Janeiro and São Paulo, Brazil; a species that bores shells of other mollusks. This occurrence has been interpreted as an invasion of this species, originally from the Caribbean. The distinguishing character of the species is the posterior extensions of the shell crossing with each other. Because specimens with this character have also been collected in the Pacific Ocean, they all have been considered a single species. However, it is possible that more than one species may be involved in such worldwide distribution. With the objective of providing full information based on Atlantic specimens, a complete anatomical description is provided, which can be used in comparative studies with specimens from other oceans. Additional distinctive features of M. aristatus are the complexity of the incurrent siphon, the kidney opening widely into the supra-branchial chamber (instead of via a nephropore, and the multi-lobed auricle.O bivalve Myoforceps aristatus (Dillwyn, 1817, também conhecido como Lithophaga aristata, tem sido recentemente coletado nas costas do Rio de Janeiro e São Paulo, Brasil; uma espécie que perfura conchas de outros moluscos. Esta ocorrência está sendo interpretada como uma invasão de uma espécie originada do Caribe. O caráter distintivo da espécie é a região posterior da concha, com extensões que se cruzam. Como espécimes com esta característica também têm sido coletados no oceano Pacífico, eles tem sido considerados como pertencentes à mesma espécie. Entretanto, é possível que mais de uma espécie possam estar envolvidas nesta suposta distribuição mundial. Com o objetivo de fornecer informação completa baseada em material do Atlântico, uma descrição anatômica completa é dada, a qual pode ser usada em estudos comparativos com espécimes de outros oceanos. As caracter

  7. Linking changes in subcellular cadmium distribution to growth and mortality rates in transplanted freshwater bivalves (Pyganodon grandis)

    International Nuclear Information System (INIS)

    Perceval, Olivier; Couillard, Yves; Pinel-Alloul, Bernadette; Campbell, Peter G.C.

    2006-01-01

    Relationships between Cd accumulation and subcellular distribution, and growth and mortality rates were examined in the freshwater bivalve Pyganodon grandis in a transplant experiment. Organisms were transferred from a clean lacustrine site to four lakes situated along a Cd concentration gradient in the mining region of Rouyn-Noranda. The bivalves were maintained in open enclosures placed in the bottom sediments of the littoral zone of all five lakes for 400 days. At the end of the experiment, metallothionein (MT) was measured in the bivalve gills with a Hg-saturation assay and Cd partitioning among the various cytosolic protein pools was determined by size-exclusion chromatography. Marked differences were observed among the five sites: the range in calculated free-cadmium ion concentrations in water overlying the sediments was 35-fold whereas Cd concentrations in the gill cytosol of the transplanted bivalves varied three-fold. In the transplanted bivalves, the distribution of gill Cd among the various cytosolic complexes also varied significantly among sites. For bivalves transplanted to the three most contaminated sites, Cd concentrations in the high molecular weight pool (HMW > 25 kDa) were significantly higher than the baseline levels determined from bivalves caged at the reference site; a similar trend was seen for Cd concentrations in the metallothionein pool (Cd-MT). For bivalves transferred to two of the high contamination sites, proportionately less of the gill cytosolic Cd was sequestered (i.e. detoxified) by MT-like proteins. Reductions in survival were also observed at these two sites, and these elevated mortalities, in turn, were consistent with the absence of indigenous bivalve populations at these sites. This result is compatible with our recent work on P. grandis populations living in lakes of the Rouyn-Noranda area, in which we demonstrated that excessive accumulation of Cd in the HMW pool of the gill cytosol of the individual mollusks could be

  8. Taxocenosis of mollusks and crustaceans on roots of rhizophora mangle (rhizophoraceae) at Cispata Bay, Cordoba, Colombia

    International Nuclear Information System (INIS)

    Quiros R, Jorge Alexander; Arias, Jorge Enrique

    2013-01-01

    Despite the existing knowledge on the ecology of mangroves at Cispata Bay, few studies have focused on the association of invertebrates on red mangrove roots, so between December 2010 and September 2011, it was characterized Taxocenosis of mollusks and crustaceans on roots of rhizophora mangle in two study sites at Cispata Bay, Colombia. For the collections of biological material were randomly taken three red mangrove roots with a diameter homogeneous by sampling station. Mollusks and crustaceans were obtained from the root surface with a scraping knife then were removed and fixed in 10 % formalin for later identification to species using specialized taxonomic keys. of the 12289 individuals collected in the four samples, 10470 belonged to the phylum Mollusca (85,2 %) and the remaining 1819 to subphylum Crustacea (14,8 %). for mollusks were identified 14 species distributed in 11 families and two classes; bivalvia and gastropoda. for crustaceans were identified 24 species distributed in 16 families and four orders; sessillia, decapoda, isopoda and amphipoda. in both sectors sampling mytella charruana, balanuseburneus and crassostrea rhizophorae were the most important species in terms of abundance, however mollusks like m. charruana and B. eburneus have a great ability to adapt and adjust to changing hydroclimatic, which was reflected in the dominance of these species in the sector with the greatest influence Sinu River. The presence of crustaceans Petrolisthes armatus and Aratus pisonii in the sector with more proximity to the Caribbean Sea indicate that are species with great mobility and physiological adaptation mechanisms.

  9. Investigation of antibiotics in mollusks from coastal waters in the Bohai Sea of China

    International Nuclear Information System (INIS)

    Li Wenhui; Shi Yali; Gao Lihong; Liu Jiemin; Cai Yaqi

    2012-01-01

    This study focused on the presence and distribution of 22 antibiotics, including eight quinolones, nine sulfonamides and five macrolides in mollusks from the Bohai Sea of China. 190 samples of eleven species were collected in 2006, 2007 and 2009. Laboratory analyses revealed that antibiotics were widely distributed in the mollusks with quinolones as the major compounds with concentrations of 0.71∼1575.10 μg/kg, which were up to two orders of magnitude higher than those of sulfonamides (0∼76.75 μg/kg) and macrolides (0∼36.21 μg/kg). The contents of quinolones and macrolides did not show significant changes from 2006, 2007 to 2009, while sulfonamides decreased significantly from 2006 to 2009. Compared with other sites, the city of Dalian was more polluted with quinolones, while Beidaihe was more contaminated with erythromycin and sulfapyridine. In addition, Mactra veneriformis and Meretrix merehjgntrix Linnaeus contained higher concentrations of quinolones and sulfamonomethoxine, while Mytilus edulis had higher levels of erythromycin and sulfapyridine. - Highlights: ► Antibiotics widely existed in the mollusks from the Bohai Sea. ► Quinolones were the major antibiotics in the mollusks. ► The concentrations of sulfonamides decreased from 2006 to 2009. - Antibiotics were widely distributed in the mollusks with quinolones as the major compounds.

  10. The mollusks in zootherapy: traditional medicine and clinical-pharmacological importance

    Directory of Open Access Journals (Sweden)

    Eraldo Medeiros Costa Neto

    2006-09-01

    Full Text Available The use of animals as sources of medicines is a cross-cultural phenomenon that is historically ancient and geographically widespread. This article reviews the use of mollusks in traditional medicine and discusses the clinical and pharmacological importance of these invertebrates. The roles that mollusks play in folk practices related to the healing and/or prevention of illnesses have been recorded in different social-cultural contexts worldwide. The clinical and therapeutic use of compounds coming from different species of mollusks is recorded in the literature. The chemistry of natural products provided by oysters, mussels, clams, sluggards, and snails has been substantially investigated, but the majority of these studies have focused on the subclasses Opistobranchia and Prosobranchia. Research into the knowledge and practices of folk medicine makes possible a better understanding of the interaction between human beings and the environment, in addition to allowing the elaboration of suitable strategies for the conservation of natural resources.

  11. New insights into the apoptotic process in mollusks: characterization of caspase genes in Mytilus galloprovincialis.

    Directory of Open Access Journals (Sweden)

    Alejandro Romero

    2011-02-01

    Full Text Available Apoptosis is an essential biological process in the development and maintenance of immune system homeostasis. Caspase proteins constitute the core of the apoptotic machinery and can be categorized as either initiators or effectors of apoptosis. Although the genes encoding caspase proteins have been described in vertebrates and in almost all invertebrate phyla, there are few reports describing the initiator and executioner caspases or the modulation of their expression by different stimuli in different apoptotic pathways in bivalves. In the present work, we characterized two initiator and four executioner caspases in the mussel Mytilus galloprovincialis. Both initiators and executioners showed structural features that make them different from other caspase proteins already described. Evaluation of the genes' tissue expression patterns revealed extremely high expression levels within the gland and gills, where the apoptotic process is highly active due to the clearance of damaged cells. Hemocytes also showed high expression values, probably due to of the role of apoptosis in the defense against pathogens. To understand the mechanisms of caspase gene regulation, hemocytes were treated with UV-light, environmental pollutants and pathogen-associated molecular patterns (PAMPs and apoptosis was evaluated by microscopy, flow cytometry and qPCR techniques. Our results suggest that the apoptotic process could be tightly regulated in bivalve mollusks by overexpression/suppression of caspase genes; additionally, there is evidence of caspase-specific responses to pathogens and pollutants. The apoptotic process in mollusks has a similar complexity to that of vertebrates, but presents unique features that may be related to recurrent exposure to environmental changes, pollutants and pathogens imposed by their sedentary nature.

  12. Lower Oligocene bivalves of Ramanian Stage from Kachchh ...

    Indian Academy of Sciences (India)

    Sehe area of western Kachchh considered their. Bed Nos. 4 and 5 as .... with very thin population. The Bermoti stream ...... Recent; Indo–Pacific. Subgenus: .... Type species: Cardium discors Lamarck' 1805; T. Eocene–Miocene; Europe–Asia ..... Shuto Tsugio 1971 Neogene Bivalves from Panay Island, the. Philippines.

  13. Distribution of organotin compounds in the bivalves of the Aegean Sea, Greece

    NARCIS (Netherlands)

    Chandrinou, S.; Pappas, K.; Nikolaou, A.; Stasinakis, A.S.; Wegener, J.W.M.; Alexandropoulos, Th.; Thomaidis, N.S.

    2007-01-01

    Five bivalve species - Mytilus galloprovinciallis (Mediterranean mussels), Venus gallina (stripped venus), Modiola barbatus L. (bearded horse mussels), Pecten jacobeus (scallops) and Callista chione (hard clams) - were collected from seven areas in Aegean Sea, Greece, between August 2001 and January

  14. Marine mollusks as bio concentrators of uranium and plutonium; Moluscos marinos como bioconcentradores de uranio y plutonio

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez R, E.; Almazan T, M. G.; Escalante G, D. C., E-mail: eduardo.ordonez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2017-09-15

    The sudden presence of certain radionuclides in the marine environment has been of global concern and has raised concerns about the nature and abundance of these, in an attempt to establish dispersion patterns from their discharge points. In the particular case of our country, there are few data on the presence and concentration of alpha emitters, such as uranium and plutonium in the littorals and due to this fact there is a need to establish their reference levels in some specific points of the Mexican littoral. This work thus raises the study of part of the biota that grows and develops in sites near the sampling points. Is known that bivalve mollusks are natural bio-concentrators due to their capacity to absorb some metals dissolved in water, being able to find contaminating metals in their soft bodies, but they also accumulate large quantities when they generate their shells from dissolved carbonates that are complex with uranium and plutonium. The shells of the mollusks were studied to determine the physicochemical characteristics of their shells and the U and Pu were also separated by means of radiochemical techniques, being then electrodeposited in steel discs and evaluated by means of alpha spectroscopy. The results of the methodology prototype are presented to determine the U and Pu dispersed in the littoral by means of the analysis of some mollusks of the zone. (Author)

  15. Short-term fluctuations in bivalve larvae compared with some environmental factors in a coastal lagoon (South Portugal

    Directory of Open Access Journals (Sweden)

    Luis M.Z. Chícaro

    2000-12-01

    Full Text Available In this study, short-term fluctuations in bivalve larvae were compared with some triggering factors for a period of sixteen months. Data on the abundance of planktonic larvae, collected two to three times a week were related to water temperature, salinity, wind velocity, tidal amplitude and chlorophyll a. Higher densities of planktonic bivalve larvae were caught between May and August, but intense fluctuations in abundance were observed. Planktonic bivalve larvae of eighteen taxa were identified. Larvae of Mytilus galloprovincialis, Cerastoderma edule, Ruditapes decussates and Venerupis spp. were the most abundant. The seasonal fluctuations of bivalve abundance seem to be controlled by temperature, the major factor in the timing of the reproduction of bivalves. Nevertheless, advection may be also a key factor during the planktonic life of bivalve species in coastal systems, such as the Ria Formosa.

  16. Light indirectly mediates bivalve habitat modification and impacts on seagrass

    DEFF Research Database (Denmark)

    Castorani, Max C. N.; Glud, Ronnie; Hasler-Sheetal, Harald

    2015-01-01

    Environmental context may influence the sign, strength, andmechanisms of species interactions but few studies have experimentally tested the potential for abiotic conditions to mediate interactions through multiple cooccurring stress pathways. Abiotic conditionsmay mediate species interactions...... by directly or indirectly influencing the effects of habitat-modifying organisms that are capable of simultaneously ameliorating and exacerbating multiple stressors. Itwas hypothesized that light availability changes seagrassmetabolismand thereby indirectly regulates bivalve habitat modification...

  17. A Darriwilian (Middle Ordovician bivalve-dominated molluscan fauna from the Stairway Sandstone, Amadeus Basin, central Australia

    Directory of Open Access Journals (Sweden)

    Kristian G. Jakobsen

    2016-12-01

    Full Text Available A bivalve-dominated molluscan fauna is described from the Darriwilian (Middle Ordovician Stairway Sandstone, Amadeus Basin, central Australia. The fauna comprises 16 species of bivalves and rostroconchs plus six gastropod species which are treated under open nomenclature. Two new bivalves, Sthenodonta paenesymmetrica sp. nov. and Modiolopsis pojetai sp. nov., are described. The relatively low-diverse molluscan fauna constitutes around 62% of the total benthic macrofauna. Approximately 75% of the molluscs comprise bivalves, especially nuculoids, which were biogeographically restricted to low latitudes during the Ordovician. The molluscan assemblage displays a very high degree of endemism at species level, though the bivalve Sthenodonta eastii also occurs in the Georgina Basin farther to the northeast. This indicates a possible marine connective seaway between the Georgina and Amadeus basins during the Darriwilian. Nuculites, Cyrtodonta, and Modiolopsis are cosmopolitan and previously reported from North China, Avalonia, and Southern Gondwana.

  18. The Mediterranean Sea Mollusks - a school shell collection

    Science.gov (United States)

    Marcu, Delia

    2017-04-01

    School: 1. "Ana Aslan" Technical College, Street Decebal 1, Cluj-Napoca, Romania 2. Orthodox Theological Seminary, Avram Iancu Square No.18, Cluj-Napoca, Romania The aim of the present project is to develop the students awareness of human activities impact on mollusks population in the Mediterranean Sea. Students have studied about the Geography of the Mediterranean Sea and they have the theoretical knowledge related to the its specific flora and fauna. One of the main fears related to the Mediterranean Sea is the loss of marine and coastal biodiversity due to biological disturbance, climate change and human activities. Out of all reasons, the human impact is considered to be the major cause of habitat loss, degradation and extinction. Regarding the Phylum Mollusca a major threat is represented by unregulated fisheries and shell traffic. In order to enable the students possibility to observe the great diversity of the Phylum Mollusca in the Mediterranean Sea, a school shell collection was made. The shells were brought by the students and they had to mention if the shells were bought, received as a souvenir or picked from their environment. Further, the students learned how to prepare the shells for the collection. The next step involved the shell classification and by this activity the students learned how to use the IUCN: International Union for Conservation of Nature database to identify the threatened species, as well as the World Register of Marine Species (WoRMS) for a correct identification of the species. As Romania romania bordering the Black Sea, the students had the opportunity to identify the mollusks species common for both the Mediterranean Sea and the Black Sea. The objectives of this study were to highlight the human-environment relation and the interconnection between environment conditions and life quality, to develop the students research, exploration and investigation skills, to be able to identify the causes of species extinction and methods

  19. Mercury accumulation in marine bivalves: Influences of biodynamics and feeding niche

    Energy Technology Data Exchange (ETDEWEB)

    Pan Ke [Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Wang Wenxiong, E-mail: wwang@ust.hk [Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

    2011-10-15

    Differences in the accumulation of mercury (Hg) in five species of marine bivalves, including scallops Chlamys nobilis, clams Ruditapes philippinarum, oysters Saccostrea cucullata, green mussels Perna viridis, and black mussels Septifer virgatus, were investigated. The bivalves displayed different patterns of Hg accumulation in terms of the body concentrations of methylmercury (MeHg) and total Hg (THg), as well as the ratio of MeHg to THg. Parameters of the biodynamics of the accumulation of Hg(II) and MeHg could reflect the species-dependent Hg concentrations in the bivalves. With the exception of black mussels, we found a significant relationship between the efflux rates of Hg(II) and the THg concentrations in the bivalves. The interspecific variations in the MeHg to THg ratio were largely controlled by the relative difference between the elimination rates of Hg(II) and MeHg. Stable isotope ({delta}{sup 13}C) analysis indicated that the five bivalve species had contrasting feeding niches, which may also affect the Hg accumulation. - Highlights: > Significant difference in Hg accumulation and MeHg:THg ratio in different bivalves. > THg concentrations in the bivalves were generally related to the efflux rates of Hg(II). > Elimination of Hg(II) and MeHg controlled the interspecific variation in MeHg:THg ratio. > MeHg and THg concentrations reflect the interaction of Hg biodynamics and food. - The species-specific body concentrations of MeHg and THg in bivalves reflect the complicated interaction between the biodynamics of Hg(II) and MeHg and the different food sources.

  20. Nature's Palette: Characterization of Shared Pigments in Colorful Avian and Mollusk Shells.

    Science.gov (United States)

    Verdes, Aida; Cho, Wooyoung; Hossain, Marouf; Brennan, Patricia L R; Hanley, Daniel; Grim, Tomáš; Hauber, Mark E; Holford, Mandë

    2015-01-01

    Pigment-based coloration is a common trait found in a variety of organisms across the tree of life. For example, calcareous avian eggs are natural structures that vary greatly in color, yet just a handful of tetrapyrrole pigment compounds are responsible for generating this myriad of colors. To fully understand the diversity and constraints shaping nature's palette, it is imperative to characterize the similarities and differences in the types of compounds involved in color production across diverse lineages. Pigment composition was investigated in eggshells of eleven paleognath bird taxa, covering several extinct and extant lineages, and shells of four extant species of mollusks. Birds and mollusks are two distantly related, calcareous shell-building groups, thus characterization of pigments in their calcareous structures would provide insights to whether similar compounds are found in different phyla (Chordata and Mollusca). An ethylenediaminetetraacetic acid (EDTA) extraction protocol was used to analyze the presence and concentration of biliverdin and protoporphyrin, two known and ubiquitous tetrapyrrole avian eggshell pigments, in all avian and molluscan samples. Biliverdin was solely detected in birds, including the colorful eggshells of four tinamou species. In contrast, protoporphyrin was detected in both the eggshells of several avian species and in the shells of all mollusks. These findings support previous hypotheses about the ubiquitous deposition of tetrapyrroles in the eggshells of various bird lineages and provide evidence for its presence also across distantly related animal taxa.

  1. Nature's Palette: Characterization of Shared Pigments in Colorful Avian and Mollusk Shells.

    Directory of Open Access Journals (Sweden)

    Aida Verdes

    Full Text Available Pigment-based coloration is a common trait found in a variety of organisms across the tree of life. For example, calcareous avian eggs are natural structures that vary greatly in color, yet just a handful of tetrapyrrole pigment compounds are responsible for generating this myriad of colors. To fully understand the diversity and constraints shaping nature's palette, it is imperative to characterize the similarities and differences in the types of compounds involved in color production across diverse lineages. Pigment composition was investigated in eggshells of eleven paleognath bird taxa, covering several extinct and extant lineages, and shells of four extant species of mollusks. Birds and mollusks are two distantly related, calcareous shell-building groups, thus characterization of pigments in their calcareous structures would provide insights to whether similar compounds are found in different phyla (Chordata and Mollusca. An ethylenediaminetetraacetic acid (EDTA extraction protocol was used to analyze the presence and concentration of biliverdin and protoporphyrin, two known and ubiquitous tetrapyrrole avian eggshell pigments, in all avian and molluscan samples. Biliverdin was solely detected in birds, including the colorful eggshells of four tinamou species. In contrast, protoporphyrin was detected in both the eggshells of several avian species and in the shells of all mollusks. These findings support previous hypotheses about the ubiquitous deposition of tetrapyrroles in the eggshells of various bird lineages and provide evidence for its presence also across distantly related animal taxa.

  2. Aliens in Paradise. Boat density and exotic coastal mollusks in Moorea Island (French Polynesia).

    Science.gov (United States)

    Ardura, Alba; Planes, Serge; Garcia-Vazquez, Eva

    2015-12-01

    Pacific islands are particularly vulnerable to the effects of invasive species. After habitat destruction or modification, invasive species are responsible for more biological extinctions than any other cause. Further, the rate of extinction of native species has been higher on islands than anywhere else in the world. Invasive species have also degraded native ecosystems. In order to detect exotic intertidal mollusk species, an extensive sampling around Moorea Island, a more or less unspoiled island surrounded by a rich coral reef habitat, has been developed considering that sampled points have different characteristics in wave exposure, algae coverage, type of substrate, distance to ports, distance to freshwater, distance sewage and boat traffic. Samples were DNA barcoded for unequivocal species assignation. The presence of five NIS among 26 species seems an important signal of introduction of alien biota in Moorea Island coast. However they were represented by a total of 38 individuals among 1487 mollusks (2.55%). While the distance to relatively big ports influenced directly species richness, the intensity of maritime traffic measured as boat density near sampling points was significantly associated with the frequency of exotic species. Other environmental factors did not show significant correlation with the frequency of exotics, suggesting that in an environment without big discontinuities, with little habitat modification, local boat traffic is the most influential factor in the spread of exotic species. This could be mitigated relatively easily by reducing boat density in local zones of ecological interest. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Cationic surfactants for control of fresh- and saltwater mollusks in nuclear cooling systems

    International Nuclear Information System (INIS)

    Post, R.M.; Mallen, E.; Lehmann, F.

    1991-01-01

    One result of the release of the US Nuclear Regulatory Commission's Generic Letter 89-13, Service Water Problems Affecting Safety-Related Equipment, was the heightened awareness of the nuclear industry to the problems of macrofouling in heat exchange systems. The principal mollusk species that contribute to freshwater macrofouling problems are Asiatic Clam (southern United States) and Zebra Mussel (Great Lakes). The predominant saltwater fouling mollusks are the Blue Mussel (Pacific, northern Atlantic), Ribbed Mussel (southern Atlantic, Gulf Coast), and American Oyster (Atlantic, Gulf Coast). The nuclear community's awareness of macrofouling problems and the ineffectiveness of intermittent chlorination programs have led to the development of several chemical control technologies for eliminating macrofouling organism infestation. One technology that has proven effective for the control of macrofouling organisms is the periodic addition of a combination of two cationic charged surfactants, specifically, alkyldimethylbenzylammonium chloride (QUAT) and dodecyl guanidine hydrochloride (DGH). Experience with the cationic surfactants at several nuclear power plants is reported

  4. Nursery function of coastal temperate benthic habitats: New insight from the bivalve recruitment perspective

    Science.gov (United States)

    Barbier, Pierrick; Meziane, Tarik; Forêt, Martin; Tremblay, Réjean; Robert, René; Olivier, Frédéric

    2017-03-01

    Marine habitat function has been typically investigated in terms of biogeochemical regulation but rarely in terms of population renewal, which is mainly controlled by recruitment dynamics. The recruitment phase is crucial for organisms with a bentho-pelagic life cycle, such as bivalves, and it regulates the population renewal success. This study provides new insight on the role of temperate benthic habitats on bivalve recruitment, as a function of nursery areas. Six dominant benthic habitats of the Chausey archipelago (Normandy, France) were studied. In each habitat, bivalve recruit assemblages were described at the end of two reproductive seasons. Furthermore, Ostrea edulis juveniles were immerged on each habitat during two months to compare growth performances and feeding status, estimated by fatty acid composition. Recruit assemblages differ from each habitat according to sediment grain-size composition and bathymetrical levels. Subtidal habitats, and especially Crepidula fornicata banks and Glycymeris glycymeris coarse sands, supported the highest species abundance and richness of recruits. All O. edulis juveniles fed on the same trophic resources but digestive glands of juveniles from C. fornicata banks were more concentrated in total fatty acids than those from subtidal G. glycymeris coarse sands and maerl banks. Our results depict the key role of subtidal and structured habitats, composed of ecosystem engineers, in enhancing bivalve recruitment and extending the bivalve population renewal. This study suggests that the crucial role of these habitats as bivalve nurseries must be integrated in management perspectives. 2-column fitting image. 1-column fitting image.

  5. Microplastics in bivalves cultured for human consumption.

    Science.gov (United States)

    Van Cauwenberghe, Lisbeth; Janssen, Colin R

    2014-10-01

    Microplastics are present throughout the marine environment and ingestion of these plastic particles (microplastics in two species of commercially grown bivalves: Mytilus edulis and Crassostrea gigas. Microplastics were recovered from the soft tissues of both species. At time of human consumption, M. edulis contains on average 0.36 ± 0.07 particles g(-1) (wet weight), while a plastic load of 0.47 ± 0.16 particles g(-1) ww was detected in C. gigas. As a result, the annual dietary exposure for European shellfish consumers can amount to 11,000 microplastics per year. The presence of marine microplastics in seafood could pose a threat to food safety, however, due to the complexity of estimating microplastic toxicity, estimations of the potential risks for human health posed by microplastics in food stuffs is not (yet) possible. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Influence of food on the assimilation of selected metals in tropical bivalves from the New Caledonia lagoon: Qualitative and quantitative aspects

    International Nuclear Information System (INIS)

    Hedouin, Laetitia; Metian, Marc; Lacoue-Labarthe, Thomas; Fichez, Renaud; Teyssie, Jean-Louis; Bustamante, Paco; Warnau, Michel

    2010-01-01

    The present study aimed at examining the influence of food quality and quantity on the assimilation efficiency (AE) of metals in two abundant bivalves in the New Caledonia lagoon, the oyster Isognomon isognomon and the clam Gafrarium tumidum. Bivalves were exposed via their food to the radiotracers of three metals of concern in New Caledonia ( 54 Mn, 57 Co and 65 Zn) under different feeding conditions (phytoplankton species, cell density, and cell-associated metal concentration). When bivalves were fed Heterocapsa triquetra, Emiliania huxleyi and Isochrysis galbana, AE of Mn, Co and Zn was strongly influenced by the phytoplankton species and by the metal considered. In contrast, when fed one given phytoplankton species previously exposed to different concentrations of Co, phytoplankton-associated Co load had no influence on the AE and on the retention time of the metal in both bivalves. Metals ingested with I. galbana displayed generally the highest AE in both bivalve species, except for Mn in clams for which the highest AE was observed for H. triquetra. Influence of food quantity was investigated by exposing bivalves to different cell densities of I. galbana (5 x 10 3 , 10 4 or 5 x 10 4 cell ml -1 ). As for food quality, food quantity was found to influence AE of Mn, Co and Zn, the highest AE being observed when bivalves were fed the lowest cell density. Overall, results indicate that the two bivalve species are able to adjust their feeding strategies according to the food conditions prevailing in their environment.

  7. Environmentally applications of invasive bivalves for water and wastewater decontamination.

    Science.gov (United States)

    Gomes, João; Matos, Ana; Quinta-Ferreira, Rosa M; Martins, Rui C

    2018-07-15

    The environmental and economic impact of invasive bivalve species implies the development of suitable pest management strategies. Chemical control is the most usual approach. However, the production of toxic intermediates as well as the unavoidable impact over non target biota is of special concern. Another approach consists on the physical removal of the animals from the invaded sites. The high biofiltration and bioaccumulation capacity of such animals make them interesting for the removal of contaminants from water and wastewater. In this context, environmental applications can be given for these pests encompassing nutrients removal for the recovery of eutrophic sites, water disinfection, organic and metal contaminants abatement. These approaches may be integrated with pest management where the physical removed animals from the invaded spots could be used for assembling biofilter for water and wastewater decontamination. However, some drawbacks must be addressed before proposing such alternative. In fact, the further spreading of the bivalves into non-invaded sites must be avoided. Moreover, some operational questions must be addressed such as the fate of contaminated animals after biofiltration. Bearing in mind the interesting results already available in this subject, this paper aims to critically overview literature regarding the environmental applications of invasive bivalves. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Biomonitoring of Heavy Metals Using Intertidal Mollusks in East Johor Coastal Waters

    International Nuclear Information System (INIS)

    Mohd Mokhlesur Rahman

    2016-01-01

    Interspecies, inter-tissue and interspatial dissimilarities of trace metals in particular body parts of Saccostrea cucullata, Thais clavigera and Nerita chameleon from the east Johor coastal waters were compared. Metals of interest includes Pb, Cd, Zn, Cu, Mn, Co, Se and Sr. Bivalve mollusk S. cucullata evidenced to be a worthy bioindicator for Zn and Cu while the two gastropod molluscs, T. clavigera for Cd and Se, and N. chameleon for Pb, Mn and Sr. The prominent concentration of metals originate in T. clavigera may be the outcome of biomagnification transfer from the S. cucullata on which they feed while for N. chameleon, it might be resulting from their herbivorous feeding behavior on algae on rocks which they graze. The metal accumulation patterns indicate consistent enrichment of essential metals in soft tissue. Values of operculum to tissue ratio (OTR) and shell to tissue (STR) higher than unity in T. clavigera indicate that operculum had higher affinities for Pb, Mn and Se while shell had higher affinities for Co and Sr. In N. chameleon, values of OTR and STR higher than unity displayed that operculum and shell had similar higher affinities for Co and Sr and Cd, Co and Sr, respectively. Significant interspatial variations (p<0.05 and p<0.01) in trace metals were noted. Assessment of metal concentration with maximum permissible limits of toxic metals in food shown the values were well within safety levels, except for Zn in S. cucullata that need to be monitored. (author)

  9. Wood-Boring Bivalves (Mollusca: Teredinidae, Pholadidae) of Pacific coast of Colombia

    International Nuclear Information System (INIS)

    Cantera K, Jaime R

    2010-01-01

    Twelve species of wood-boring bivalves, ten of the family Teredinidae and two of family Pholadidae were collected in mangroves at 6 locations of the Pacific coast of Colombia. This paper presents a brief escription of these species, including size, ecological notes and geographical distribution.

  10. Adaptive morphologies and guild structure in a high-diversity bivalve fauna from an early Campanian rocky shore, Ivö Klack (Sweden)

    DEFF Research Database (Denmark)

    Sørensen, Anne Mehlin; Surlyk, Finn; Jagt, John W. M.

    2012-01-01

    habitats. Study of the functional morphology of bivalve shells and comparison with extant relatives has resulted in a subdivision of the fauna into seven guilds and five habitats. The bivalve fauna represents a withinhabitat, time-averaged assemblage to which none of the species was introduced from...

  11. First evidence of immunomodulation in bivalves under seawater acidification and increased temperature.

    Directory of Open Access Journals (Sweden)

    Valerio Matozzo

    Full Text Available Water acidification, temperature increases and changes in seawater salinity are predicted to occur in the near future. In such a global climate change (GCC scenario, there is growing concern for the health status of both wild and farmed organisms. Bivalve molluscs, an important component of coastal marine ecosystems, are at risk. At the immunological level, the ability of an organism to maintain its immunosurveillance unaltered under adverse environmental conditions may enhance its survival capability. To our knowledge, only a few studies have investigated the effects of changing environmental parameters (as predicted in a GCC scenario on the immune responses of bivalves. In the present study, the effects of both decreased pH values and increased temperature on the important immune parameters of two bivalve species were evaluated for the first time. The clam Chamelea gallina and the mussel Mytilus galloprovincialis, widespread along the coast of the Northwestern Adriatic Sea, were chosen as model organisms. Bivalves were exposed for 7 days to three pH values (8.1, 7.7 and 7.4 at two temperatures (22 and 28°C. Three independent experiments were carried out at salinities of 28, 34 and 40 PSU. The total haemocyte count, Neutral Red uptake, haemolymph lysozyme activity and total protein levels were measured. The results obtained demonstrated that tested experimental conditions affected significantly most of the immune parameters measured in bivalves, even if the variation pattern of haemocyte responses was not always linear. Between the two species, C. gallina appeared more vulnerable to changing pH and temperature than M. galloprovincialis. Overall, this study demonstrated that climate changes can strongly affect haemocyte functionality in bivalves. However, further studies are needed to clarify better the mechanisms of action of changing environmental parameters, both individually and in combination, on bivalve haemocytes.

  12. Morphometric Studies on Anodonta Anatine Bivalve Population from the Dognecea Lake

    Directory of Open Access Journals (Sweden)

    Marian Bura

    2011-10-01

    Full Text Available In the Dognecea Lake, near town Bocsa in Caras-Severin county a strong bivalve population has been discovered from the duck mussel specie (Anodonta anatina. Harvested individuals were transported to the Aquaculture laboratory where measurements and correct identification was made. This specie is considered endangered but in Banat area, especially in the Dognecea Lake it is well represented, having an ecological importance, but the bivalve can have an economical importance too, due to the high percentage of edible part of 56.5%.

  13. Bivalve aquaculture transfers in Atlantic Europe. Part A: Transfer activities and legal framework

    DEFF Research Database (Denmark)

    Muehlbauer, F.; Fraser, D.; Brenner, M.

    2014-01-01

    environment and address economic considerations remains unanswered. This study provides the first overview of bivalve transfer activities for aquaculture purposes along the European Atlantic coast. Existing international and EU legislation is described, and potential weaknesses in the existing legislative......Intentional transfers of numerous bivalve species have had a long tradition and are commonly conducted along the European Atlantic coast. However numerous studies have concluded that intentional transfer of species for aquaculture purposes is one of the most principal vectors for the introduction...... frameworks are discussed. Recommendations for the development of integrated risk assessment methods are given. These may help to minimize the intrinsic threats of transfer activities in marine environments. The resulting impacts and effects of transfer activities of bivalves for aquaculture purpose...

  14. Inducing the Alternative Oxidase Forms Part of the Molecular Strategy of Anoxic Survival in Freshwater Bivalves

    Directory of Open Access Journals (Sweden)

    Maria S. Yusseppone

    2018-02-01

    Full Text Available Hypoxia in freshwater ecosystems is spreading as a consequence of global change, including pollution and eutrophication. In the Patagonian Andes, a decline in precipitation causes reduced lake water volumes and stagnant conditions that limit oxygen transport and exacerbate hypoxia below the upper mixed layer. We analyzed the molecular and biochemical response of the North Patagonian bivalve Diplodon chilensis after 10 days of experimental anoxia (<0.2 mg O2/L, hypoxia (2 mg O2/L, and normoxia (9 mg O2/L. Specifically, we investigated the expression of an alternative oxidase (AOX pathway assumed to shortcut the regular mitochondrial electron transport system (ETS during metabolic rate depression (MRD in hypoxia-tolerant invertebrates. Whereas, the AOX system was strongly upregulated during anoxia in gills, ETS activities and energy mobilization decreased [less transcription of glycogen phosphorylase (GlyP and succinate dehydrogenase (SDH in gills and mantle]. Accumulation of succinate and induction of malate dehydrogenase (MDH activity could indicate activation of anaerobic mitochondrial pathways to support anoxic survival in D. chilensis. Oxidative stress [protein carbonylation, glutathione peroxidase (GPx expression] and apoptotic intensity (caspase 3/7 activity decreased, whereas an unfolded protein response (HSP90 was induced under anoxia. This is the first clear evidence of the concerted regulation of the AOX and ETS genes in a hypoxia-tolerant freshwater bivalve and yet another example that exposure to hypoxia and anoxia is not necessarily accompanied by oxidative stress in hypoxia-tolerant mollusks.

  15. Inducing the Alternative Oxidase Forms Part of the Molecular Strategy of Anoxic Survival in Freshwater Bivalves

    Science.gov (United States)

    Yusseppone, Maria S.; Rocchetta, Iara; Sabatini, Sebastian E.; Luquet, Carlos M.; Ríos de Molina, Maria del Carmen; Held, Christoph; Abele, Doris

    2018-01-01

    Hypoxia in freshwater ecosystems is spreading as a consequence of global change, including pollution and eutrophication. In the Patagonian Andes, a decline in precipitation causes reduced lake water volumes and stagnant conditions that limit oxygen transport and exacerbate hypoxia below the upper mixed layer. We analyzed the molecular and biochemical response of the North Patagonian bivalve Diplodon chilensis after 10 days of experimental anoxia (<0.2 mg O2/L), hypoxia (2 mg O2/L), and normoxia (9 mg O2/L). Specifically, we investigated the expression of an alternative oxidase (AOX) pathway assumed to shortcut the regular mitochondrial electron transport system (ETS) during metabolic rate depression (MRD) in hypoxia-tolerant invertebrates. Whereas, the AOX system was strongly upregulated during anoxia in gills, ETS activities and energy mobilization decreased [less transcription of glycogen phosphorylase (GlyP) and succinate dehydrogenase (SDH) in gills and mantle]. Accumulation of succinate and induction of malate dehydrogenase (MDH) activity could indicate activation of anaerobic mitochondrial pathways to support anoxic survival in D. chilensis. Oxidative stress [protein carbonylation, glutathione peroxidase (GPx) expression] and apoptotic intensity (caspase 3/7 activity) decreased, whereas an unfolded protein response (HSP90) was induced under anoxia. This is the first clear evidence of the concerted regulation of the AOX and ETS genes in a hypoxia-tolerant freshwater bivalve and yet another example that exposure to hypoxia and anoxia is not necessarily accompanied by oxidative stress in hypoxia-tolerant mollusks. PMID:29527172

  16. Biostratigraphy of the Miocene of Zeven, county of Bremervoerde, based on mollusks

    Energy Technology Data Exchange (ETDEWEB)

    Hinsch, W

    1969-06-01

    Cores from 2 water wells and a gas well, containing a very rich assemblage of fossil mollusks, were used to clarify the biostratigraphy of the Miocene near Zeven, especially in the sands corresponding to the brown coal deposits. The overburden contains the fauna of the Reinbek, the underburden 2 faunas of the Hemmoor, one of brachyhaline and one of euhaline characteristics. A list of the 174 species found, and of those most useful for age determinations, is given. The correspondence between several local nomenclatures in the Helvetian, Burdigalian and Aquitanian formations is tabulated. (12 refs.)

  17. Trophic Dynamics of Filter Feeding Bivalves in the Yangtze Estuarine Intertidal Marsh: Stable Isotope and Fatty Acid Analyses

    Science.gov (United States)

    Wang, Sikai; Jin, Binsong; Qin, Haiming; Sheng, Qiang; Wu, Jihua

    2015-01-01

    Benthic bivalves are important links between primary production and consumers, and are essential intermediates in the flow of energy through estuarine systems. However, information on the diet of filter feeding bivalves in estuarine ecosystems is uncertain, as estuarine waters contain particulate matter from a range of sources and as bivalves are opportunistic feeders. We surveyed bivalves at different distances from the creek mouth at the Yangtze estuarine marsh in winter and summer, and analyzed trophic dynamics using stable isotope (SI) and fatty acid (FA) techniques. Different bivalve species had different spatial distributions in the estuary. Glauconome chinensis mainly occurred in marshes near the creek mouth, while Sinonovacula constricta preferred the creek. Differences were found in the diets of different species. S. constricta consumed more diatoms and bacteria than G. chinensis, while G. chinensis assimilated more macrophyte material. FA markers showed that plants contributed the most (38.86 ± 4.25%) to particular organic matter (POM) in summer, while diatoms contributed the most (12.68 ± 1.17%) during winter. Diatoms made the largest contribution to the diet of S. constricta in both summer (24.73 ± 0.44%) and winter (25.51 ± 0.59%), and plants contributed no more than 4%. This inconsistency indicates seasonal changes in food availability and the active feeding habits of the bivalve. Similar FA profiles for S. constricta indicated that the bivalve had a similar diet composition at different sites, while different δ13C results suggested the diet was derived from different carbon sources (C4 plant Spartina alterniflora and C3 plant Phragmites australis and Scirpus mariqueter) at different sites. Species-specific and temporal and/or spatial variability in bivalve feeding may affect their ecological functions in intertidal marshes, which should be considered in the study of food webs and material flows in estuarine ecosystems. PMID:26261984

  18. Thyasirid bivalves from Cretaceous and Paleogene cold seeps

    Directory of Open Access Journals (Sweden)

    Krzysztof Hryniewicz

    2017-11-01

    Full Text Available We present a systematic study of thyasirid bivalves from Cretaceous to Oligocene seep carbonates worldwide. Eleven species of thyasirid bivalves are identified belonging to three genera: Conchocele, Maorithyas, and Thyasira. Two species are new: Maorithyas humptulipsensis sp. nov. from middle Eocene seep carbonates in the Humptulips Formation, Washington State, USA, and Conchocele kiritachiensis sp. nov. from the late Eocene seep deposit at Kiritachi, Hokkaido, Japan. Two new combinations are provided: Conchocele townsendi (White, 1890 from Maastrichtian strata of the James Ross Basin, Antarctica, and Maorithyas folgeri (Wagner and Schilling, 1923 from Oligocene rocks from California, USA. Three species are left in open nomenclature. We show that thyasirids have Mesozoic origins and appear at seeps before appearing in “normal” marine environments. These data are interpreted as a record of seep origination of thyasirids, and their subsequent dispersal to non-seep environments. We discuss the age of origination of thyasirids in the context of the origin of the modern deep sea fauna and conclude that thyasirids could have deep sea origins. This hypothesis is supported by the observed lack of influence of the Cretaceous and Paleogene Oceanic Anoxic Events on the main evolutionary lineages of the thyasirids, as seen in several other members of the deep sea fauna.

  19. Bio-accumulation kinetics of radioruthenium in marine bivalves. Laboratory study

    International Nuclear Information System (INIS)

    Mu, D.H.; Yan, S.P.; Gu, Y.J.; Li, D.J.; Du, J.Z.

    2007-01-01

    Three kinds of marine bivalves (wild Saccostrea cucullata, aquacultured Perna viridis and aquacultured Pinctada martens), collected from Daya Bay, the South China Sea, were used to investigate the bio-accumulation of radioruthenium in the glass aquarium with natural seawater (pH 8.20, 35 per mille salinity, filtered by 0.45 μm) at ambient temperature under laboratory feeding conditions. The experimental results show that the stead-state of biology concentration factor (BCF, ml/g) of radioruthenium was approached around 6 days for most species of bivalves. The values of BCF in shells are the highest in organs all the three bivalves. The orders of BCF values (ml x g -1 ) are as: Perna viridis (33.2) < Saccostrea cucullata (47.0) < Pinctada martensi (208.4) for shells and Saccostrea cucullata (1.5) < Pinctada martensi (2.2) ∼ Perma viridis (2.4) for soft tissues, respectively, after exposed for 14 days. The rate constants of uptake and elimination of radioruthenium on marine bivalves were also discussed by first-order kinetics model. The Pinctada martensi may be applicable to be an indictor for monitoring radioruthenium among the three bivalves. (author)

  20. Ecology of megabenthic bivalve communities from sandy beaches on the south coast of Portugal

    Directory of Open Access Journals (Sweden)

    Marta M. Rufino

    2010-03-01

    Full Text Available Ecological aspects of 75 megabenthic bivalve species found on the south coast of Portugal (from Vila Real to Sagres were studied based on the information provided by seasonal bivalve surveys from 2000 to 2007 (8600 hauls, simultaneously using a razor shell dredge and a clam dredge. Of the 75 species identified, 36 occurred less than 30 times, and thus were considered rare in the area. The remaining 39 bivalves were analysed according to their occurrence, bathymetric distribution, geographic preferences, seasonal preferences, burying-depth, beach exposure and river mouth proximity. All species belonging to the Pharidae and Solenidae families (razor shells and most Tellinidae were significantly more frequent in the razor shell dredge (indicating deeper burying in the sediment, whilst the families Cardiidae and Donacidae were significantly more frequent in the clam dredge (indicating that these species are probably closer to the sediment surface. As for the season, most bivalve species occurred similarly in both seasons (19 sp; 49%, but a large proportion were more abundant during the autumn surveys (17 sp., 44%, whereas only three species were commoner during the spring surveys. Most species belonging to the families Cardiidae and Mactridae were commoner in the autumn surveys. The spatial distribution differed between species and cluster analysis identified four communities with greater geographic affinity. Species belonging to the family Cardiidae were preferably found in the western part (WB and the eastern part (S of the study area, whereas the families Donacidae, Mactridae and Tellinidae occurred mainly in the central area (EB and the eastern (S coastal sectors. Overall, shallower species (modal depth at 3-6 m showed greater occurrences and abundances than the deeper ones, and the depth pattern observed did not change between seasons. Donacidae and Mactridae (except Mactra glauca were represented essentially by shallow species, whereas

  1. Bivalve aquaculture-environment interactions in the context of climate change.

    Science.gov (United States)

    Filgueira, Ramón; Guyondet, Thomas; Comeau, Luc A; Tremblay, Réjean

    2016-12-01

    Coastal embayments are at risk of impacts by climate change drivers such as ocean warming, sea level rise and alteration in precipitation regimes. The response of the ecosystem to these drivers is highly dependent on their magnitude of change, but also on physical characteristics such as bay morphology and river discharge, which play key roles in water residence time and hence estuarine functioning. These considerations are especially relevant for bivalve aquaculture sites, where the cultured biomass can alter ecosystem dynamics. The combination of climate change, physical and aquaculture drivers can result in synergistic/antagonistic and nonlinear processes. A spatially explicit model was constructed to explore effects of the physical environment (bay geomorphic type, freshwater inputs), climate change drivers (sea level, temperature, precipitation) and aquaculture (bivalve species, stock) on ecosystem functioning. A factorial design led to 336 scenarios (48 hydrodynamic × 7 management). Model outcomes suggest that the physical environment controls estuarine functioning given its influence on primary productivity (bottom-up control dominated by riverine nutrients) and horizontal advection with the open ocean (dominated by bay geomorphic type). The intensity of bivalve aquaculture ultimately determines the bivalve-phytoplankton trophic interaction, which can range from a bottom-up control triggered by ammonia excretion to a top-down control via feeding. Results also suggest that temperature is the strongest climate change driver due to its influence on the metabolism of poikilothermic organisms (e.g. zooplankton and bivalves), which ultimately causes a concomitant increase of top-down pressure on phytoplankton. Given the different thermal tolerance of cultured species, temperature is also critical to sort winners from losers, benefiting Crassostrea virginica over Mytilus edulis under the specific conditions tested in this numerical exercise. In general, it is

  2. Students' knowledge on the African giant mollusk Achatina fulica in a public school in the Recife metropolitan region

    Directory of Open Access Journals (Sweden)

    Marcos Souto Alves

    2007-03-01

    Full Text Available The African giant mollusk Achatina fulica Bowdich, 1822 was introduced into Brazil in 1988 as a substitute for the European escargot Helix sp. This action did not induce the expected results and the gastropod has become an invasive species according to records in 23 Brazilian states. The presence of A. fulica has been reported to many towns in the state of Pernambuco. This work was carried out in order to evaluate, from an ethnoscientific approach, student knowledge about this giant African mollusk in a public school of Cabo de Santo Agostinho (Pernambuco. The Collective Subject Discourse (CSD technique was applied to the data obtained. The pupils' discourse revealed the existence of previous knowledge about A. fulica, especially on the following issues: disease transmission, taxonomy, environmental impacts brought about by the introduction of exotic species, and the process of ingress and growth of the mollusk in the human body. The authors emphasize the need of considering students' previous knowledge in order to plan and implement educational strategies related to wildlife conservation and exotic species management.

  3. An overview of chemosynthetic symbioses in bivalves from the North Atlantic and Mediterranean Sea

    Science.gov (United States)

    Duperron, S.; Gaudron, S. M.; Rodrigues, C. F.; Cunha, M. R.; Decker, C.; Olu, K.

    2013-05-01

    Deep-sea bivalves found at hydrothermal vents, cold seeps and organic falls are sustained by chemosynthetic bacteria that ensure part or all of their carbon nutrition. These symbioses are of prime importance for the functioning of the ecosystems. Similar symbioses occur in other bivalve species living in shallow and coastal reduced habitats worldwide. In recent years, several deep-sea species have been investigated from continental margins around Europe, West Africa, eastern Americas, the Gulf of Mexico, and from hydrothermal vents on the Mid-Atlantic Ridge. In parallel, numerous, more easily accessible shallow marine species have been studied. Herein we provide a summary of the current knowledge available on chemosymbiotic bivalves in the area ranging west-to-east from the Gulf of Mexico to the Sea of Marmara, and north-to-south from the Arctic to the Gulf of Guinea. Characteristics of symbioses in 53 species from the area are summarized for each of the five bivalve families documented to harbor chemosynthetic symbionts (Mytilidae, Vesicomyidae, Solemyidae, Thyasiridae and Lucinidae). Comparisons are made between the families, with special emphasis on ecology, life cycle, and connectivity. Chemosynthetic symbioses are a major adaptation to ecosystems and habitats exposed to reducing conditions. However, relatively little is known regarding their diversity and functioning, apart from a few "model species" on which effort has focused over the last 30 yr. In the context of increasing concern about biodiversity and ecosystems, and increasing anthropogenic pressure on oceans, we advocate a better assessment of the diversity of bivalve symbioses in order to evaluate the capacities of these remarkable ecological and evolutionary units to withstand environmental change.

  4. An overview of chemosynthetic symbioses in bivalves from the North Atlantic and Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    S. Duperron

    2013-05-01

    Full Text Available Deep-sea bivalves found at hydrothermal vents, cold seeps and organic falls are sustained by chemosynthetic bacteria that ensure part or all of their carbon nutrition. These symbioses are of prime importance for the functioning of the ecosystems. Similar symbioses occur in other bivalve species living in shallow and coastal reduced habitats worldwide. In recent years, several deep-sea species have been investigated from continental margins around Europe, West Africa, eastern Americas, the Gulf of Mexico, and from hydrothermal vents on the Mid-Atlantic Ridge. In parallel, numerous, more easily accessible shallow marine species have been studied. Herein we provide a summary of the current knowledge available on chemosymbiotic bivalves in the area ranging west-to-east from the Gulf of Mexico to the Sea of Marmara, and north-to-south from the Arctic to the Gulf of Guinea. Characteristics of symbioses in 53 species from the area are summarized for each of the five bivalve families documented to harbor chemosynthetic symbionts (Mytilidae, Vesicomyidae, Solemyidae, Thyasiridae and Lucinidae. Comparisons are made between the families, with special emphasis on ecology, life cycle, and connectivity. Chemosynthetic symbioses are a major adaptation to ecosystems and habitats exposed to reducing conditions. However, relatively little is known regarding their diversity and functioning, apart from a few "model species" on which effort has focused over the last 30 yr. In the context of increasing concern about biodiversity and ecosystems, and increasing anthropogenic pressure on oceans, we advocate a better assessment of the diversity of bivalve symbioses in order to evaluate the capacities of these remarkable ecological and evolutionary units to withstand environmental change.

  5. Structure-based function prediction of the expanding mollusk tyrosinase family

    Science.gov (United States)

    Huang, Ronglian; Li, Li; Zhang, Guofan

    2017-11-01

    Tyrosinase (Ty) is a common enzyme found in many different animal groups. In our previous study, genome sequencing revealed that the Ty family is expanded in the Pacific oyster ( Crassostrea gigas). Here, we examine the larger number of Ty family members in the Pacific oyster by high-level structure prediction to obtain more information about their function and evolution, especially the unknown role in biomineralization. We verified 12 Ty gene sequences from Crassostrea gigas genome and Pinctada fucata martensii transcriptome. By using phylogenetic analysis of these Tys with functionally known Tys from other molluscan species, eight subgroups were identified (CgTy_s1, CgTy_s2, MolTy_s1, MolTy-s2, MolTy-s3, PinTy-s1, PinTy-s2 and PviTy). Structural data and surface pockets of the dinuclear copper center in the eight subgroups of molluscan Ty were obtained using the latest versions of prediction online servers. Structural comparison with other Ty proteins from the protein databank revealed functionally important residues (HA1, HA2, HA3, HB1, HB2, HB3, Z1-Z9) and their location within these protein structures. The structural and chemical features of these pockets which may related to the substrate binding showed considerable variability among mollusks, which undoubtedly defines Ty substrate binding. Finally, we discuss the potential driving forces of Ty family evolution in mollusks. Based on these observations, we conclude that the Ty family has rapidly evolved as a consequence of substrate adaptation in mollusks.

  6. Interactive effects of CO2 and trace metals on the proteasome activity and cellular stress response of marine bivalves Crassostrea virginica and Mercenaria mercenaria

    International Nuclear Information System (INIS)

    Götze, Sandra; Matoo, Omera B.; Beniash, Elia; Saborowski, Reinhard; Sokolova, Inna M.

    2014-01-01

    Highlights: • Elevated P CO 2 enhanced accumulation of Cu and Cd in the gills of mollusks. • The proteasome activities were affected by metals but robust to elevated P CO 2 . • Exposure to Cd and Cu had opposite effects on the proteasome activity. • Combined exposure to Cu and elevated P CO 2 negatively affected energy status. - Abstract: Increased anthropogenic emission of CO 2 changes the carbonate chemistry and decreases the pH of the ocean. This can affect the speciation and the bioavailability of metals in polluted habitats such as estuaries. However, the effects of acidification on metal accumulation and stress response in estuarine organisms including bivalves are poorly understood. We studied the interactive effects of CO 2 and two common metal pollutants, copper (Cu) and cadmium (Cd), on metal accumulation, intracellular ATP/ubiquitin-dependent protein degradation, stress response and energy metabolism in two common estuarine bivalves—Crassostrea virginica (eastern oyster) and Mercenaria mercenaria (hard shell clam). Bivalves were exposed for 4–5 weeks to clean seawater (control) and to either 50 μg L −1 Cu or 50 μg L −1 Cd at one of three partial pressures of CO 2 (P CO 2 ∼395, ∼800 and ∼1500 μatm) representative of the present-day conditions and projections of the Intergovernmental Panel for Climate Change (IPCC) for the years 2100 and 2250, respectively. Clams accumulated lower metal burdens than oysters, and elevated P CO 2 enhanced the Cd and Cu accumulation in mantle tissues in both species. Higher Cd and Cu burdens were associated with elevated mRNA expression of metal binding proteins metallothionein and ferritin. In the absence of added metals, proteasome activities of clams and oysters were robust to elevated P CO 2 , but P CO 2 modulated the proteasome response to metals. Cd exposure stimulated the chymotrypsin-like activity of the oyster proteasome at all CO 2 levels. In contrast, trypsin- and caspase-like activities of

  7. Interactive effects of CO₂ and trace metals on the proteasome activity and cellular stress response of marine bivalves Crassostrea virginica and Mercenaria mercenaria

    Energy Technology Data Exchange (ETDEWEB)

    Götze, Sandra [Alfred Wegener Institute, Helmholtz Centre for Polar, Marine Research, Functional Ecology, 27570 Bremerhaven (Germany); Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223 (United States); Matoo, Omera B. [Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223 (United States); Beniash, Elia [Department of Oral Biology, University of Pittsburgh, Pittsburgh, PA (United States); Saborowski, Reinhard [Alfred Wegener Institute, Helmholtz Centre for Polar, Marine Research, Functional Ecology, 27570 Bremerhaven (Germany); Sokolova, Inna M., E-mail: isokolov@uncc.edu [Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223 (United States)

    2014-04-01

    Highlights: • Elevated PCO₂ enhanced accumulation of Cu and Cd in the gills of mollusks. • The proteasome activities were affected by metals but robust to elevated PCO₂. • Exposure to Cd and Cu had opposite effects on the proteasome activity. • Combined exposure to Cu and elevated PCO₂ negatively affected energy status. - Abstract: Increased anthropogenic emission of CO₂ changes the carbonate chemistry and decreases the pH of the ocean. This can affect the speciation and the bioavailability of metals in polluted habitats such as estuaries. However, the effects of acidification on metal accumulation and stress response in estuarine organisms including bivalves are poorly understood. We studied the interactive effects of CO₂ and two common metal pollutants, copper (Cu) and cadmium (Cd), on metal accumulation, intracellular ATP/ubiquitin-dependent protein degradation, stress response and energy metabolism in two common estuarine bivalves—Crassostrea virginica (eastern oyster) and Mercenaria mercenaria (hard shell clam). Bivalves were exposed for 4–5 weeks to clean seawater (control) and to either 50 μg L⁻¹ Cu or 50 μg L⁻¹ Cd at one of three partial pressures of CO₂ PCO₂ ~395, ~800 and ~1500 μatm) representative of the present-day conditions and projections of the Intergovernmental Panel for Climate Change (IPCC) for the years 2100 and 2250, respectively. Clams accumulated lower metal burdens than oysters, and elevated PCO₂ enhanced the Cd and Cu accumulation in mantle tissues in both species. Higher Cd and Cu burdens were associated with elevated mRNA expression of metal binding proteins metallothionein and ferritin. In the absence of added metals, proteasome activities of clams and oysters were robust to elevated PCO₂, but PCO₂ modulated the proteasome response to metals. Cd exposure stimulated the chymotrypsin-like activity of the oyster proteasome

  8. Bivalves: From individual to population modelling

    NARCIS (Netherlands)

    Saraiva, S.; van der Meer, J.; Kooijman, S.A.L.M.

    2014-01-01

    An individual based population model for bivalves was designed, built and tested in a 0D approach, to simulate the population dynamics of a mussel bed located in an intertidal area. The processes at the individual level were simulated following the dynamic energy budget theory, whereas initial egg

  9. A rapid assessment survey of invasive species of macrobenthic invertebrates in Korean waters

    Science.gov (United States)

    Park, Chul; Kim, Sung-Tae; Hong, Jae-Sang; Choi, Keun-Hyung

    2017-09-01

    Introduced species are a growing and imminent threat to living marine resources in parts of the world's oceans. The present study is a rapid assessment survey of invasive macrobenthic invertebrate species in Korean ports. We surveyed over 40 ports around Korea during the period of May 2010 March 2013. Among the sampling sites were concrete walls, docks and associated floats, bumpers, tires, and ropes which might harbor non-native species. We found 15 invasive species as follows: one Sponge, two Bryozoans, three Mollusks, one Polychaete, four Cirripedes, and four Ascidians. Three morphologically similar species, namely X. atrata, M. galloprovincialis, and X. securis were further examined for distinctions in their morphology. Although they could be reasonably distinguished based on shell shapes, significant overlap was noted so that additional analysis may be required to correctly distinguish them. Although many of the introduced species have already spread to all three coastal areas, newly arrived invasive species showed a relatively restricted range, with a serpulid polychaete Ficopomatus enigmaticus and a mytilid bivalve Xenostrobus securis found only at a few sites on the East Coast. An exception is for Balanus perforatus, which has rapidly colonized the East coast of Korea following its introduction into the region. Successful management of invasive macrobenthic invertebrates should be established in order to contain the spread of these newly arrived species.

  10. Lower Oligocene bivalves of Ramanian Stage from Kachchh, Gujarat, India

    Science.gov (United States)

    Kachhara, R. P.; Jodhawat, R. L.; Devi, K. Bigyapati

    2012-04-01

    ), Maniyara Fort (23°28'05″N; 68°37'E) Rakhdi Dam (23°27'26″N; 68°40'10″E) and Waior (23°25'05″N; 68°41'37″E) with a view to highlight the entombed bivalve taxa. Authors have encountered 53 species of which 23 are restricted to the Ramanian Stage.

  11. Bivalve grazing can shape phytoplankton communities

    Science.gov (United States)

    Lucas, Lisa; Cloern, James E.; Thompson, Janet K.; Stacey, Mark T.; Koseff, Jeffrey K.

    2016-01-01

    The ability of bivalve filter feeders to limit phytoplankton biomass in shallow waters is well-documented, but the role of bivalves in shaping phytoplankton communities is not. The coupled effect of bivalve grazing at the sediment-water interface and sinking of phytoplankton cells to that bottom filtration zone could influence the relative biomass of sinking (diatoms) and non-sinking phytoplankton. Simulations with a pseudo-2D numerical model showed that benthic filter feeding can interact with sinking to alter diatom:non-diatom ratios. Cases with the smallest proportion of diatom biomass were those with the fastest sinking speeds and strongest bivalve grazing rates. Hydrodynamics modulated the coupled sinking-grazing influence on phytoplankton communities. For example, in simulations with persistent stratification, the non-sinking forms accumulated in the surface layer away from bottom grazers while the sinking forms dropped out of the surface layer toward bottom grazers. Tidal-scale stratification also influenced vertical gradients of the two groups in opposite ways. The model was applied to Suisun Bay, a low-salinity habitat of the San Francisco Bay system that was transformed by the introduction of the exotic clam Potamocorbula amurensis. Simulation results for this Bay were similar to (but more muted than) those for generic habitats, indicating that P. amurensis grazing could have caused a disproportionate loss of diatoms after its introduction. Our model simulations suggest bivalve grazing affects both phytoplankton biomass and community composition in shallow waters. We view these results as hypotheses to be tested with experiments and more complex modeling approaches.

  12. [Radioecological studies of freshwater mollusks in the Chernobyl accident exclusion zone].

    Science.gov (United States)

    Gudkov, D I; Nazarov, A B; Dziubenko, E V; Kaglian, A E; Klenus, V G

    2009-01-01

    Species-specificity and dynamics of 90Sr, 137Cs and some transuranic elements accumulation in bivalve and gastropod freshwater molluscs of the Chernobyl exclusion zone during 1997-2008 was analyzed. The results of radiation dose and chromosome aberration rate estimation and the analysis of hemolymph composition of freshwater snail (Lymnaea stagnalis L.) was produced. The absorbed dose rate was registered in the range of 0.3-85.0 microGy/h. In closed water bodies the heightened chromosome aberration rate (up to 27%) in embryo tissues, and also the change of haematological indexes for the adult individuals of snails was registered.

  13. Bivalve fouling of nuclear power plant service-water systems. Volume 2. Current status of biofouling surveillance and control techniques

    International Nuclear Information System (INIS)

    Daling, P.M.; Johnson, K.I.

    1985-03-01

    This report describes the current status of techniques for detection and control of cooling-water system fouling by bivalve mollusks at nuclear power plants. The effectiveness of these techniques is evaluated on the basis of information gathered from a literature review and in interviews with nuclear power plant personnel. Biofouling detection techniques examined in this report include regular maintenance, in-service inspection, and testing. Generally, these methods have been inadequate for detecting biofouling. Recommendations for improving biofouling detection capabilities are presented. Biofouling prevention (or control) methods that are examined in this report include intake screen systems, thermal treatment, preventive maintenance, chemical treatment alternatives, and antifoulant coatings. Recommendations for improving biofouling control methods at operating nuclear power plants are presented. Additional techniques that could be implemented at future power plants or that require further research are also described

  14. American Tertiary mollusks of the genus Clementia

    Science.gov (United States)

    Woodring, W.P.

    1927-01-01

    Aside from its value as an aid in determining the age of Tertiary beds, the chief interest of the genus Clementia lies in the anomalous features of its present and former distribution. An attempt is made in this paper to trace its geologic history, to point out its paleobiologic significance, and to describe all the known American Tertiary species. The fossils from Colombia used in preparing this report were collected during explorations made under the direction of Dr. 0. B. Hopkins, chief geologist of the Imperial Oil Co. (Ltd.), who kindly donated them to the United States National Museum. Dr. T. Wayland Vaughan, of the Scripps Institution of Oceanography, furnished information relating to specimens collected by him in Mexico. Dr. Bruce L. Clark, of the University of California; Dr. G. Dallas Hanna, of the California Academy of Sciences; Dr. H. A. Pilsbry, of the Philadelphia Academy of Natural Sciences; and Dr. W. D. Matthew, of the American Museum of Natural History, generously loaned type specimens and other material. Doctor Clark and Doctor Hanna also gave information concerning the Tertiary species from California. Mr. Ralph B. Stewart, of the University of California, read the manuscript, and I have taken advantage of his suggestions. I am also indebted to Mr. L. R. Cox, of the British Museum, for information relating to the fossil species from Persia, Zanzibar, and Burma, and to Dr. Axel A. Olsson, of the International Petroleum Co., for data concerning undescribed Tertiary species from Peru.

  15. The miRNA biogenesis in marine bivalves

    Directory of Open Access Journals (Sweden)

    Umberto Rosani

    2016-03-01

    Full Text Available Small non-coding RNAs include powerful regulators of gene expression, transposon mobility and virus activity. Among the various categories, mature microRNAs (miRNAs guide the translational repression and decay of several targeted mRNAs. The biogenesis of miRNAs depends on few gene products, essentially conserved from basal to higher metazoans, whose protein domains allow specific interactions with dsRNA. Here, we report the identification of key genes responsible of the miRNA biogenesis in 32 bivalves, with particular attention to the aquaculture species Mytilus galloprovincialis and Crassostrea gigas. In detail, we have identified and phylogenetically compared eight evolutionary conserved proteins: DROSHA, DGCR8, EXP5, RAN, DICER TARBP2, AGO and PIWI. In mussels, we recognized several other proteins participating in the miRNA biogenesis or in the subsequent RNA silencing. According to digital expression analysis, these genes display low and not inducible expression levels in adult mussels and oysters whereas they are considerably expressed during development. As miRNAs play an important role also in the antiviral responses, knowledge on their production and regulative effects can shed light on essential molecular processes and provide new hints for disease prevention in bivalves.

  16. Climate change and body size shift in Mediterranean bivalve assemblages: unexpected role of biological invasions.

    Science.gov (United States)

    Nawrot, Rafał; Albano, Paolo G; Chattopadhyay, Devapriya; Zuschin, Martin

    2017-08-16

    Body size is a synthetic functional trait determining many key ecosystem properties. Reduction in average body size has been suggested as one of the universal responses to global warming in aquatic ecosystems. Climate change, however, coincides with human-enhanced dispersal of alien species and can facilitate their establishment. We address effects of species introductions on the size structure of recipient communities using data on Red Sea bivalves entering the Mediterranean Sea through the Suez Canal. We show that the invasion leads to increase in median body size of the Mediterranean assemblage. Alien species are significantly larger than native Mediterranean bivalves, even though they represent a random subset of the Red Sea species with respect to body size. The observed patterns result primarily from the differences in the taxonomic composition and body-size distributions of the source and recipient species pools. In contrast to the expectations based on the general temperature-size relationships in marine ectotherms, continued warming of the Mediterranean Sea indirectly leads to an increase in the proportion of large-bodied species in bivalve assemblages by accelerating the entry and spread of tropical aliens. These results underscore complex interactions between changing climate and species invasions in driving functional shifts in marine ecosystems. © 2017 The Author(s).

  17. Report of Freshwater Mollusks Workshop 19-20 May 1981.

    Science.gov (United States)

    1982-05-01

    RELOCATION OF LAMPSILIS HIGGINSI IN THE UPPER MISSISSIPPI RIVER ....... ....................... 104 David Nelson HIGGINS ’ EYE MUSSEL RECOVERY PLAN...0830 The Higgins ’ Eye Mussel Recovery Team - Dr. Edward Stern, University of Wisconsin Dealing with Endangered Mollusks at Corps of Engineers District...typically dark yellowish-brown to brown in color. Quadrula stapes appears to be most closely related to Q. intermedia which is endemic to the Tennessee

  18. Spermatozoan ultrastructure in the trigonioid bivalve Neotrigonia margaritacea Lamarck (Mollusca): Comparison with other bivalves, especially Trigonioida and Unionoida

    Science.gov (United States)

    Healy, J. M.

    1996-06-01

    Spermatozoa of the trigonioid bivalve Neotrigonia margaritacea (Lamarck) (Trigoniidae, Trigonioida) are examined ultrastructurally. A cluster of discoidal, proacrosomal vesicles (between 9 to 15 in number) constitutes the acrosomal complex at the nuclear apex. The nucleus is short (2.4 2.6 μm long, maximum diameter 2.2 μm), blunt-conical in shape, and exhibits irregular lacunae within its contents. Five or sometimes four round mitochondria are impressed into shallow depressions in the base of the nucleus as is a discrete centriolar fossa. The mitochondria surround two orthogonally arranged centrioles to form, collectively, the midpiece region. The distal centriole, anchored by nine satellite fibres to the plasma membrane, acts as a basal body to the sperm flagellum. The presence of numerous proacrosomal vesicles instead of a single, conical acrosomal vesicle sets Neotrigonia (and the Trigonioida) apart from other bivalves, with the exception of the Unionoida which are also known to exhibit this multivesicular condition. Spermatozoa of N. margaritacea are very similar to those of the related species Neotrigonia bednalli (Verco) with the exception that the proacrosomal vesicles of N. margaritacea are noticeably larger than those of N. bednalli.

  19. RECONSTRUCTING DIET COMPOSITION ON THE BASIS OF FECES IN A MOLLUSK-EATING WADER, THE KNOT CALIDRIS-CANUTUS

    NARCIS (Netherlands)

    DEKINGA, A; PIERSMA, T

    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.

  20. 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

  1. Ocean acidification increases cadmium accumulation in marine bivalves: a potential threat to seafood safety.

    Science.gov (United States)

    Shi, Wei; Zhao, Xinguo; Han, Yu; Che, Zhumei; Chai, Xueliang; Liu, Guangxu

    2016-01-21

    To date, the effects of ocean acidification on toxic metals accumulation and the underlying molecular mechanism remains unknown in marine bivalve species. In the present study, the effects of the realistic future ocean pCO2 levels on the cadmium (Cd) accumulation in the gills, mantle and adductor muscles of three bivalve species, Mytilus edulis, Tegillarca granosa, and Meretrix meretrix, were investigated. The results obtained suggested that all species tested accumulated significantly higher Cd (p ocean acidification-induced increase in Cd accumulation may have occurred due to (i) the ocean acidification increased the concentration of Cd and the Cd(2+)/Ca(2+) in the seawater, which in turn increased the Cd influx through Ca channel; (ii) the acidified seawater may have brought about epithelia damage, resulting in easier Cd penetration; and (iii) ocean acidification hampered Cd exclusion.

  2. Shell growth and environmental control of methanophyllic Thyasirid bivalves from Svalbard cold seeps

    Science.gov (United States)

    Carroll, Michael; Åström, Emmelie; Ambrose, William; Locke, William; Oliver, Graham; Hong, Wei-Li; Carroll, JoLynn

    2016-04-01

    The analysis of molluscan shell material (sclerochronology) can provide information about an organism's age, growth history, and environmental conditions during its lifetime. Bivalve molluscs are common members of hydrothermal vents and methane cold seeps communities where, supported by chemosynthetic symbionts, they can reach high density and biomass. But little is known about methane-associated bivalve populations inhabiting high-Arctic cold seeps, and sclerochronological analysis of methane-influenced bivalves is rare. We measured growth rates and elemental and isotopic shell signatures in a newly discovered species of bivalve (Thyasiridae) from cold seeps at 350-390m depth southwest of Svalbard. First discovered in 2014, recently described shells of Thyasira capitanea sp.nov. were found at 2 independent seep systems in Storfjordrenna. Mean shell carbon isotopic ratios from inorganic δ13C (mean = -4.8‰) and organic δ13C (mean = -26.9‰) fractions clearly indicate a methane influenced habitat and food source for these organisms. Shell mineral ratios (Li/Ca, Mg/Ca, Mn/Ca, Fe/Ca, Sr/Ca, Ba/Ca, Pb/Ca) sampled along the axis of growth with laser-ablated ICP-MS exhibit variability through time and between sites, suggesting that concentrations of these elements that may be affected by methane emissions. The mineralogical data also elucidates the internal pattern of shell deposition and growth checks, and combined with the isotopic and growth rate data, enables us to interpret the temporal history of methane release from these locations.

  3. Miocene and Pleistocene mollusks from San Andres Island (Caribbean Sea, Colombia) and Paleogeographic considerations

    International Nuclear Information System (INIS)

    Diaz M, Juan Manuel; Garcia Llano, Cesar Fernando

    2010-01-01

    San Andres Island is the largest emerged portion of the oceanic archipelago of San Andres and Providencia, southwestern Caribbean Sea; it originated as a coralline atoll during Miocene times. The central and highest part of the island consists of a calcareous crest, the San Andres Formation, formed by Neogene lagoonal and reefal deposits. This crest is surrounded by a calcareous platform of Pleistocene age (San Luis Formation) which emerges only along the island coast, whereas its most part is submerged and covered by a Recent reef complex. Fossil material of molluscs from these two formations was collected in various sites throughout the island and taxonomically identified. In the four sites sampled in the San Andres Formation, material belonging to 19 gastropod and 37 bivalve species was obtained, most of them relatively well represented in other geologic formations of the Caribbean region that are stratigraphically situated between the upper Miocene and the middle Pliocene. Some elements occurring in this formation, such as Ostrea haitiensis, Meretrix dariena and Siphocypraea henekeni, were widely distributed in the Caribbean Miocene Province. In the San Luis Formation, material belonging to 18 gastropod and 11 bivalve species was obtained, most of them also represented in the Recent molluscan fauna of the region. The estimated age of this formation is Sangamonian, hence corresponding to similar formations occurring in Grand Cayman, Jamaica, Hispaniola, the Netherlands Antilles and other Caribbean islands, with which it also shows a great similarity in the composition of the molluscan fauna.

  4. El Niño impact on mollusk biomineralization-implications for trace element proxy reconstructions and the paleo-archeological record.

    Directory of Open Access Journals (Sweden)

    Alberto Pérez-Huerta

    Full Text Available Marine macroinvertebrates are ideal sentinel organisms to monitor rapid environmental changes associated with climatic phenomena. These organisms build up protective exoskeletons incrementally by biologically-controlled mineralization, which is deeply rooted in long-term evolutionary processes. Recent studies relating potential rapid environmental fluctuations to climate change, such as ocean acidification, suggest modifications on carbonate biominerals of marine invertebrates. However, the influence of known, and recurrent, climatic events on these biological processes during active mineralization is still insufficiently understood. Analysis of Peruvian cockles from the 1982-83 large magnitude El Niño event shows significant alterations of the chemico-structure of carbonate biominerals. Here, we show that bivalves modify the main biomineralization mechanism during the event to continue shell secretion. As a result, magnesium content increases to stabilize amorphous calcium carbonate (ACC, inducing a rise in Mg/Ca unrelated to the associated increase in sea-surface temperature. Analysis of variations in Sr/Ca also suggests that this proxy should not be used in these bivalves to detect the temperature anomaly, while Ba/Ca peaks are recorded in shells in response to an increase in productivity, or dissolved barium in seawater, after the event. Presented data contribute to a better understanding of the effects of abrupt climate change on shell biomineralization, while also offering an alternative view of bivalve elemental proxy reconstructions. Furthermore, biomineralization changes in mollusk shells can be used as a novel potential proxy to provide a more nuanced historical record of El Niño and similar rapid environmental change events.

  5. Ecological drivers and habitat associations of estuarine bivalves

    OpenAIRE

    McKeon, C. Seabird; Tunberg, Bj?rn G.; Johnston, Cora A.; Barshis, Daniel J.

    2015-01-01

    Community composition of the infaunal bivalve fauna of the St. Lucie Estuary and southern Indian River Lagoon, eastern Florida was sampled quarterly for 10 years as part of a long-term benthic monitoring program. A total of 38,514 bivalves of 137 taxa were collected and identified. We utilized this data, along with sediment samples and environmental measurements gathered concurrently, to assess the community composition, distribution, and ecological drivers of the infaunal bivalves of this es...

  6. Deciphering the link between doubly uniparental inheritance of mtDNA and sex determination in bivalves: Clues from comparative transcriptomics

    Science.gov (United States)

    Capt, Charlotte; Renaut, Sébastien; Ghiselli, Fabrizio; Milani, Liliana; Johnson, Nathan A.; Sietman, Bernard E.; Stewart, Donald; Breton, Sophie

    2018-01-01

    Bivalves exhibit an astonishing diversity of sexual systems and sex-determining mechanisms. They can be gonochoric, hermaphroditic or androgenetic, with both genetic and environmental factors known to determine or influence sex. One unique sex-determining system involving the mitochondrial genome has also been hypothesized to exist in bivalves with doubly uniparental inheritance (DUI) of mtDNA. However, the link between DUI and sex determination remains obscure. In this study, we performed a comparative gonad transcriptomics analysis for two DUI-possessing freshwater mussel species to better understand the mechanisms underlying sex determination and DUI in these bivalves. We used a BLAST reciprocal analysis to identify orthologs between Venustaconcha ellipsiformis and Utterbackia peninsularis and compared our results with previously published sex-specific bivalve transcriptomes to identify conserved sex-determining genes. We also compared our data with other DUI species to identify candidate genes possibly involved in the regulation of DUI. A total of ∼12,000 orthologous relationships were found, with 2,583 genes differentially expressed in both species. Among these genes, key sex-determining factors previously reported in vertebrates and in bivalves (e.g., Sry, Dmrt1, Foxl2) were identified, suggesting that some steps of the sex-determination pathway may be deeply conserved in metazoans. Our results also support the hypothesis that a modified ubiquitination mechanism could be responsible for the retention of the paternal mtDNA in male bivalves, and revealed that DNA methylation could also be involved in the regulation of DUI. Globally, our results suggest that sets of genes associated with sex determination and DUI are similar in distantly-related DUI species.

  7. Reproductive investment in the intertidal bivalve Macoma balthica

    Science.gov (United States)

    Honkoop, P. J. C.; Van der Meer, J.; Beukema, J. J.; Kwast, D.

    1999-05-01

    Bivalve eggs generally contain large amounts of lipids which, in comparison with proteins and carbohydrates, have high energy contents and are thus costly in energetic terms. As lipid contents vary between species, comparisons of reproductive investments should not only include numbers and sizes of eggs, but also their energy content. We estimated the investment in egg material of mature females of the Baltic tellin Macoma balthica (L.) in terms of both mass and energy content. All mass below a minimum body mass (below which no eggs are produced) was defined as structural mass. This threshold amounts to a body mass index (BMI) of 5.6 (ash-free dry mass per cubic shell length in mg cm -3). More than half (55%) of the mass above the structural mass was invested in egg material and 45% in extra somatic tissue and tissue for production and storage of gametes. This means that the amount of eggs spawned ranged from 0 (at BMI = 5.6 mg cm -3) to 33% of the total ash-free dry mass (at a high BMI value of 14 mg cm -3). Eggs contained a relatively large amount of lipids, about 30% of their ash-free dry mass, whereas non-egg material contained only about 7% lipids. Eggs of two other bivalves in the Wadden Sea, the cockle Cerastoderma edule and the mussel Mytilus edulis, were smaller and contained only about 11% and 20% lipids, respectively. Energy content of M. balthica eggs amounted to ˜0.006 J, in the other two species to ˜0.002 J. The function of the more expensive eggs in M. balthica may be related to its early spawning in spring, causing slower larval development until first feeding.

  8. The use of bivalves as rapid, real-time indicators of aquatic pollution

    International Nuclear Information System (INIS)

    Markich, S.J.

    1995-01-01

    The ability of bivalves to filter large volumes of water on a daily basis, combined with the relatively high permeability of their cell membranes, make them valuable organisms to use in the contemporary detection of pollution. Bivalves are well known to respond to chemical contaminants by isolating their soft tissues from the aquatic medium by valve closure. The sensory acuity (via specialized sensory regions including the osphradium) and associated repertoire of this behavioral response can be employed to assess subtle effects exerted by chemical contaminants, such as complex effluents, that may ultimately influence the survival of these organisms. As hazard assessment tools, behavioral studies reflect sublethal toxicity and often yield a highly sensitive estimate of the lowest observable effect concentration (LOEC). Moreover, valve movement behavior has been identified as one of the more sensitive biological early warning measures to a variety of aquatic contaminants, in comparison with those used in other aquatic animal phyla. Therefore, the valve movement behavior of both freshwater (Hyridella depressa, Velesunio angasi and V. ambiguus) and marine (Mytilus edulis) bivalves was continuously monitored, using an on-line computer based data acquisition system, during exposure to either trace metals (e.g. Cu, Cd, Mn and U) or complex effluents (ie treated sewage effluent and acid leachate derived from contaminated Sydney Harbour sediments), in the context of using the valve movement behavior of the bivalve species to indicate the biological significance of exposure to the above-mentioned pollutants. The results indicate that several components of the valve movement behavior of each bivalve provide quantifiable and ecologically interpretable sub-lethal endpoints for the rapid and sensitive evaluation of waters containing either complex effluents or elevated levels of trace metals

  9. Molecular Typing of Vibrio parahaemolyticus Strains Isolated from Mollusks in the North Adriatic Sea.

    Science.gov (United States)

    Rahman, Mohammad Shamsur; Carraro, Roberta; Cardazzo, Barbara; Carraro, Lisa; Meneguolo, Davide Boscolo; Martino, Maria Elena; Andreani, Nadia Andrea; Bordin, Paola; Mioni, Renzo; Barco, Lisa; Novelli, Enrico; Balzan, Stefania; Fasolato, Luca

    2017-08-01

    Vibrio parahaemolyticus is an emerging foodborne pathogen in the Mediterranean, usually associated with shellfish consumption. The increase in the number of outbreaks in Europe is primarily associated with the global warming of the ocean that has a great impact on the spread and genetic selection of waterborne pathogens. The primary role of Italy in Europe's mollusk production, together with the fact that cases of infections with V. parahaemolyticus are not always notified to the European community, highlighted the necessity of acquiring new information about the epidemiological involvement of shellfish products. The aim of the study was to provide useful insights into the first steps of the Risk Assessment associated with V. parahaemolyticus through the molecular characterization of isolates from commercialized mollusks. A total of 102 strains identified as V. parahaemolyticus were investigated as part of a larger sampling (1-year survey) from several shellfish species collected from the Venice lagoon and the North Adriatic sea. All strains were characterized by multilocus sequence typing and tested for the presence of virulence genes (trh and tdh). The study of sampling/environmental factors and epidemiological analyses was performed to describe the behaviors of the different genetic populations. The population structure analysis highlighted three genetic clusters that could be subject to temperature selection during cold (≤15°C) and warm (>16°C) seasons. Moreover, other factors, such as molluscan species (clams/mussels), probably played a role in the distribution of genetic clusters. Although few strains carried the virulence factors (n = 6 trh + ), epidemiological links with clinical isolates and a local dissemination of some sequence types were underlined. This work provides a useful background on the genotype spread as a first step in the Hazard Identification in light of future climate changes.

  10. Bioaccumulation of selected metals in bivalves (Unionidae) and Phragmites australis inhabiting a municipal water reservoir

    OpenAIRE

    Rzymski, Piotr; Niedzielski, Przemysław; Klimaszyk, Piotr; Poniedziałek, Barbara

    2014-01-01

    Urbanization can considerably affect water reservoirs by, inter alia, input, and accumulation of contaminants including metals. Located in the course of River Cybina, Maltański Reservoir (Western Poland) is an artificial shallow water body built for recreation and sport purposes which undergoes restoration treatment (drainage) every 4 years. In the present study, we demonstrate an accumulation of nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in water, sediment, three bivalve species (Anodo...

  11. Remarks on the influence of fluorine exhalations upon the mollusks in the surroundings of Zlar nad Hronom

    Energy Technology Data Exchange (ETDEWEB)

    Lisicky, M

    1973-01-01

    Seventeen localities in the area contaminated by fluorine and its immediate vicinity were investigated. The malacocenoses in stagnant water and in the forest were most injured. Two hypothesis concerning the possible influence of hydrogen fluoride on the water-mollusks are advanced: direct effect, i.e., corrosion of the conch; and indirect effect - the HJ blocks the calcium and the only way out for the snails is to gnaw the conches. In the contaminated area the malacocenoses tend to show high dominance of one euryoecic species. 7 references.

  12. Benzene Synthesis for 14C Measurements and Evaluation of Uncertainty in Mollusk Shells

    International Nuclear Information System (INIS)

    Romero del Hombrebueno, B.; Simon, M. A.; Larena, P.

    2002-01-01

    This work describes the method and Instrumentation used by Environmental Isotopes laboratory of the CIEMAT Analytical Chemistry Laboratory (DIAE) for the synthesis of benzene from carbonates of mollusk shells and the liquid scintillation counting of 14 C for radiocarbon dating in these samples. The usefulness of mollusk shells for 14 C dating are considered. (Author) 15 refs

  13. Uncharted waters: Bivalves of midway atoll and integrating mathematics into biology education

    Science.gov (United States)

    McCully, Kristin M.

    To protect and conserve the Earth's biodiversity and ecosystem services, it is important not only to understand and conserve species and ecosystems, but also to instill an understanding and appreciation for biodiversity and ecosystem services in the next generations of both scientists and citizens. Thus, this dissertation combines research into the ecology and identity of large bivalves at Midway Atoll in the Northwestern Hawaiian Islands (NWHI) with research on pedagogical strategies for integrating mathematics into undergraduate biology education. The NWHI is one of the few remaining large, mainly intact, predator-dominated coral reef ecosystems and one of the world's largest marine protected areas. Previous bivalve studies focused on the black-lipped pearl oyster, Pinctada margaritifera, which was heavily harvested in the late 1920s, has not recovered, and is now a candidate species for restoration. First, I combined remote sensing, geographic information systems, SCUBA, and mathematical modeling to quantify the abundance, spatial distributions, and filtration capacity of large epifaunal bivalves at Midway Atoll. These bivalves are most abundant on the forereef outside the atoll, but densities are much lower than reported on other reefs, and Midway's bivalves are unlikely to affect plankton abundance and productivity inside the lagoon. Second, I used molecular techniques and phylogenetic reconstructions to identify pearl oysters (Pinctada) from Midway Atoll as P. maculata , a species not previously reported in Hawaii. As a small morphologically cryptic species, P. maculata may be a native species that has not been collected previously, a native species that has been identified incorrectly as the morphologically similar P. radiata, or it may be a recent introduction or natural range extension from the western Pacific. Finally, I review science education literature integrating mathematics into undergraduate biology curricula, and then present and evaluate a

  14. Moluscos dulceacuícolas exóticos en Chile Exotic freshwater mollusks in Chile

    Directory of Open Access Journals (Sweden)

    Sergio Letelier V.

    2007-10-01

    Full Text Available Las especies de moluscos exóticas dulceacuícolas registradas en esta contribución, corresponden a ejemplares recolectados en humedales en acuarios comerciales o interceptados en barreras aduaneras, así como de referencias bibliográficas. Un total de 7 especies pertenecientes a 6 géneros fueron identificadas: Pomacea bridgesii; Helobia sp.; Thiara (Melanoides tuberculata; Melanoides maculata; Physa sp.; Physella venustula y Biomphalaria sp. Melanoides maculata fue recolectada en el río Lluta y clasificada como especie criptogénica. Los moluscos exóticos recolectados podrían tener éxito en su establecimiento si se considera la vulnerabilidad de los hábitats nativos debido al cambio en las condiciones climáticas globales o a las elevaciones térmicas producidas en el sector costero por los fenómenos de El Niño. En este sentido, las especies subtropicales observadas se podrían considerar como no endémicas y vectores potenciales de zoonosis parasitarias. Las principales vías de introducción de moluscos dulceacuícolas exóticos se derivaron del intercambio comercial, por lo cual, y frente a su incremento interregional, se hace necesario recopilar datos ecológicos y taxonómicos adecuados que permitan evaluar el riesgo de su establecimiento, así como servir de base para la aplicación de futuros tratamientos en bioseguridad.The exotic freshwater mollusk species we report here were collected in wetlands, commercial aquariums, or were given to us by government officials who intercepted some exotic species at customs offices. Other records came from the specialized literature. These species are Pomacea bridgesii; Helobia sp.; Thiara (Melanoides tuberculata; Melanoides maculata; Physa sp., Physella venustula and Biomphalaria sp. It is not clear how Melanoides maculata, found in the Río Lluta, reached Chile. The exotic species collected could expand their ranges in Chilean territory given global environmental and climate change or the

  15. 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.

  16. Availability of pearl producing marine bivalves in south-eastern coast of Bangladesh and culture potentialities

    Directory of Open Access Journals (Sweden)

    Md Ataur Rahman

    2015-12-01

    Full Text Available The present study was conducted during September 2014 to July 2015 to identify the pearl bearing bivalves in south-eastern coast of Bangladesh and culture potentialities of marine oyster in captivity based on field investigation. A total of 7 pearl bearing bivalve species were identified in the coast with a salinity of 18-34 ppt, pH 8.1-8.3 and water depth ranged 0.2-2.0 meter in their habitat. From the collected bivalves, most abundant oyster species windowpane oyster, Placuna placenta (Linnaeus, 1758 was reared in fiber glass tanks with seawater for a period of 6 months. During rearing highest survival rate of 88% was observed in T1 with sandy and gravel substratum and lowest survival rate of 78% was found in T2 with muddy substratum. Average temperature and salinity were varied between 24 °C-25 °C and 21-26 ppt respectively. From the reared oyster, highest 54 nos. small pearls in the month of April and lowest 7 pearls in December from a single P. placenta were obtained. The study proved that pearls can be obtained from the marine oysters in captivity in Bangladesh, and this offers large scale culture potentialities in our coast.

  17. Dinophysis caudata generated lipophilic shellfish toxins in bivalves from the Nanji Islands, East China Sea

    Science.gov (United States)

    Jiang, Tao; Xu, Yixiao; Li, Yang; Qi, Yuzao; Jiang, Tianjiu; Wu, Feng; Zhang, Fan

    2014-01-01

    A 12-month program of monitoring potentially toxic microalgae (that produce lipophilic shellfish toxins; LSTs) and their toxins in bivalves was conducted from April 2006 to March 2007 in the Nanji Islands, East China Sea. Two Dinophysis species, D. caudata and D. acuminata, were identified, and D. caudata was found to be the dominant species. D. caudata was detected in water samples between April and June 2006, and between February and March 2007. It reached its highest abundances in May, with a mean abundance of 1.38×102 cells/L in surface water and 1.25×102 cells/L in bottom water (cultured bivalves sampled between April and June were contaminated with LSTs, with an average toxicity of 85 μg okadaic acid (OA) eq./100 g meat, which was four times higher than the Chinese regulatory limit (20 μg OA eq./100 g meat). Ten out of fifteen wild samples (66.7%) collected during the same period were positive for LSTs, and contained an average LST toxicity of 45 μg OA eq./100 g meat (more than twice the regulatory value). Cultured Patinopecten yessoensis collected on 15 May 2006 had the highest toxicity, 320 μg OA eq./100 g meat, and relatively high toxicities (80 to 160 μg OA eq./100 g meat) were found in bivalves until the end of July.

  18. Characterizing Photosymbiosis Between Fraginae Bivalves and Symbiodinium Using Phylogenetics and Stable Isotopes

    Directory of Open Access Journals (Sweden)

    Jingchun Li

    2018-04-01

    Full Text Available Photosymbiotic associations between heterotrophic hosts and photosynthetic algae play crucial roles in maintaining the trophic and structural integrity of coral reef ecosystems. The marine bivalve subfamily Fraginae contains both non-symbiotic and photosymbiotic lineages, making it an ideal comparative system to study the origin and evolutionary adaptations of photosymbiosis. The symbiotic species exhibit unique morphological adaptations to photosymbiosis. However, the basic biology of these photosymbiotic relationships, such as symbiont diversity and nutritional benefits, has not been thoroughly characterized. In this study, we examined the general morphology of four Fraginae species occupying different depths (0–10 m: Corculum cardissa, Fragum fragum, Fragum scruposum, and Fragum sueziense. Abundant symbionts were found in the mantle, gill, and part of the foot, contained in tubular networks within host tissues. We used molecular phylogenetics to investigate the algal symbiont community of these Fraginae species. Results showed that symbionts from all four species are dinoflagellates belonging to the Symbiodinium clade C and we did not detect any host-specific or geographic-specific genetic structures within the symbionts. We also used stable carbon isotope analyses to examine whether the cockles are directly utilizing photosynthetically derived carbon sources. All species show less depleted 13C compared to filter-feeding bivalves, suggesting at least part of their organic carbon is derived directly from the symbionts. However, 13C depletion of Fragum sueziense collected from deeper habitats are less distinguishable from filter-feeding bivalves. This indicates that species in deeper habitats may rely less on photosymbiosis due to the reduced light availability. Given that the symbiotic fragines exhibit varying morphologies, habitats, and utilization of symbiont photosynthesis, the subfamily represents an ideal model system to study

  19. Semi-automatic surface sediment sampling system - A prototype to be implemented in bivalve fishing surveys

    Science.gov (United States)

    Rufino, Marta M.; Baptista, Paulo; Pereira, Fábio; Gaspar, Miguel B.

    2018-01-01

    In the current work we propose a new method to sample surface sediment during bivalve fishing surveys. Fishing institutes all around the word carry out regular surveys with the aim of monitoring the stocks of commercial species. These surveys comprise often more than one hundred of sampling stations and cover large geographical areas. Although superficial sediment grain sizes are among the main drivers of benthic communities and provide crucial information for studies on coastal dynamics, overall there is a strong lack of this type of data, possibly, because traditional surface sediment sampling methods use grabs, that require considerable time and effort to be carried out on regular basis or on large areas. In face of these aspects, we developed an easy and un-expensive method to sample superficial sediments, during bivalve fisheries monitoring surveys, without increasing survey time or human resources. The method was successfully evaluated and validated during a typical bivalve survey carried out on the Northwest coast of Portugal, confirming that it had any interference with the survey objectives. Furthermore, the method was validated by collecting samples using a traditional Van Veen grabs (traditional method), which showed a similar grain size composition to the ones collected by the new method, on the same localities. We recommend that the procedure is implemented on regular bivalve fishing surveys, together with an image analysis system to analyse the collected samples. The new method will provide substantial quantity of data on surface sediment in coastal areas, using a non-expensive and efficient manner, with a high potential application in different fields of research.

  20. Immunotoxicological effects of environmental contaminants on marine bivalves.

    Science.gov (United States)

    Renault, T

    2015-09-01

    Coastal areas are complex environments frequently contaminated by numerous pollutants that represent a potential threat to marine organisms, especially bivalves. These pollutants may have major ecological consequences. Although effects of different environmental contaminants on the immune system in marine bivalves have been already reported, a few of reviews summarizes these effects. The main purpose of this chapter relies on summarizing recent body of data on immunotoxicity in bivalves subjected to contaminants. Immune effects of heavy metals, pesticides, HAP, PCB and pharmaceuticals are presented and discussed and a particular section is devoted to nanoparticle effects. A large body of literature is now available on this topic. Finally, the urgent need of a better understanding of complex interactions between contaminants, marine bivalves and infectious diseases is noticed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Environmental influence on population dynamics of the bivalve Anomalocardia brasiliana

    Science.gov (United States)

    Corte, Guilherme Nascimento; Coleman, Ross A.; Amaral, A. Cecília Z.

    2017-03-01

    Understanding how species respond to the environment in terms of population attributes (e.g. abundance, growth, mortality, fecundity, and productivity) is essential to protect ecologically and economically important species. Nevertheless, responses of macrobenthic populations to environmental features are overlooked due to the need of consecutive samplings and time-consuming measurements. We examined the population dynamics of the filter-feeding bivalve Anomalocardia brasiliana on a tidal flat over the course of one year to investigate the hypothesis that, as accepted for macrobenthic communities, populations inhabiting environments with low hydrodynamic conditions such as tidal flat should have higher attributes than populations inhabiting more energetic habitats (i.e. areas more influenced by wave energy such as reflective and intermediate beaches). This would be expected because the harsh conditions of more energetic habitats force organisms to divert more energy towards maintenance, resulting in lower population attributes. We found that A. brasiliana showed moderate growth and secondary production at the study area. Moreover the recruitment period was restricted to a few months. A comparison with previous studies showed that, contrary to expected, A. brasiliana populations from areas with low hydrodynamic conditions have lower abundance, growth, recruitment and turnover rate. It is likely that morphodynamic characteristics recorded in these environments, such as larger periods of air exposure and lower water circulation, may affect food conditions for filter-feeding species and increase competition. In addition, these characteristics may negatively affect macrobenthic species by enhancing eutrophication processes and anoxia. Overall, our results suggest that models accepted and applied at the macrobenthic community level might not be directly extended to A. brasiliana populations.

  2. Ecological drivers and habitat associations of estuarine bivalves

    Directory of Open Access Journals (Sweden)

    C. Seabird McKeon

    2015-11-01

    Full Text Available Community composition of the infaunal bivalve fauna of the St. Lucie Estuary and southern Indian River Lagoon, eastern Florida was sampled quarterly for 10 years as part of a long-term benthic monitoring program. A total of 38,514 bivalves of 137 taxa were collected and identified. We utilized this data, along with sediment samples and environmental measurements gathered concurrently, to assess the community composition, distribution, and ecological drivers of the infaunal bivalves of this estuary system. Salinity had the strongest influence on bivalve assemblage across the 15 sites, superseding the influences of sediment type, water turbidity, temperature and other environmental parameters. The greatest diversity was found in higher salinity euhaline sites, while the greatest abundance of individual bivalves was found in medium salinity mixohaline sites, the lowest diversity and abundances were found in the low salinity oligohaline sites, demonstrating a strong positive association between salinity and diversity/abundance. Water management decisions for the estuary should incorporate understanding of the role of salinity on bivalve diversity, abundance, and ecosystem function.

  3. Ecological drivers and habitat associations of estuarine bivalves.

    Science.gov (United States)

    McKeon, C Seabird; Tunberg, Björn G; Johnston, Cora A; Barshis, Daniel J

    2015-01-01

    Community composition of the infaunal bivalve fauna of the St. Lucie Estuary and southern Indian River Lagoon, eastern Florida was sampled quarterly for 10 years as part of a long-term benthic monitoring program. A total of 38,514 bivalves of 137 taxa were collected and identified. We utilized this data, along with sediment samples and environmental measurements gathered concurrently, to assess the community composition, distribution, and ecological drivers of the infaunal bivalves of this estuary system. Salinity had the strongest influence on bivalve assemblage across the 15 sites, superseding the influences of sediment type, water turbidity, temperature and other environmental parameters. The greatest diversity was found in higher salinity euhaline sites, while the greatest abundance of individual bivalves was found in medium salinity mixohaline sites, the lowest diversity and abundances were found in the low salinity oligohaline sites, demonstrating a strong positive association between salinity and diversity/abundance. Water management decisions for the estuary should incorporate understanding of the role of salinity on bivalve diversity, abundance, and ecosystem function.

  4. Multiple Beneficial Lipids Including Lecithin Detected in the Edible Invasive Mollusk Crepidula fornicata from the French Northeastern Atlantic Coast

    Science.gov (United States)

    Dagorn, Flore; Buzin, Florence; Couzinet-Mossion, Aurélie; Decottignies, Priscilla; Viau, Michèle; Rabesaotra, Vony; Barnathan, Gilles; Wielgosz-Collin, Gaëtane

    2014-01-01

    The invasive mollusk Crepidula fornicata, occurring in large amounts in bays along the French Northeastern Atlantic coasts, may have huge environmental effects in highly productive ecosystems where shellfish are exploited. The present study aims at determining the potential economic value of this marine species in terms of exploitable substances with high added value. Lipid content and phospholipid (PL) composition of this mollusk collected on the Bourgneuf Bay were studied through four seasons. Winter specimens contained the highest lipid levels (5.3% dry weight), including 69% of PLs. Phosphatidylcholine (PC) was the major PL class all year, accounting for 63.9% to 88.9% of total PLs. Consequently, the winter specimens were then investigated for PL fatty acids (FAs), and free sterols. Dimethylacetals (DMAs) were present (10.7% of PL FA + DMA mixture) revealing the occurrence of plasmalogens. More than forty FAs were identified, including 20:5n-3 (9.4%) and 22:6n-3 (7.3%) acids. Fourteen free sterols were present, including cholesterol at 31.3% of the sterol mixture and about 40% of phytosterols. These data on lipids of C. fornicata demonstrate their positive attributes for human nutrition and health. The PL mixture, rich in PC and polyunsaturated FAs, offers an interesting alternative source of high value-added marine lecithin. PMID:25532566

  5. Multiple beneficial lipids including lecithin detected in the edible invasive mollusk Crepidula fornicata from the French Northeastern Atlantic coast.

    Science.gov (United States)

    Dagorn, Flore; Buzin, Florence; Couzinet-Mossion, Aurélie; Decottignies, Priscilla; Viau, Michèle; Rabesaotra, Vony; Barnathan, Gilles; Wielgosz-Collin, Gaëtane

    2014-12-22

    The invasive mollusk Crepidula fornicata, occurring in large amounts in bays along the French Northeastern Atlantic coasts, may have huge environmental effects in highly productive ecosystems where shellfish are exploited. The present study aims at determining the potential economic value of this marine species in terms of exploitable substances with high added value. Lipid content and phospholipid (PL) composition of this mollusk collected on the Bourgneuf Bay were studied through four seasons. Winter specimens contained the highest lipid levels (5.3% dry weight), including 69% of PLs. Phosphatidylcholine (PC) was the major PL class all year, accounting for 63.9% to 88.9% of total PLs. Consequently, the winter specimens were then investigated for PL fatty acids (FAs), and free sterols. Dimethylacetals (DMAs) were present (10.7% of PL FA + DMA mixture) revealing the occurrence of plasmalogens. More than forty FAs were identified, including 20:5n-3 (9.4%) and 22:6n-3 (7.3%) acids. Fourteen free sterols were present, including cholesterol at 31.3% of the sterol mixture and about 40% of phytosterols. These data on lipids of C. fornicata demonstrate their positive attributes for human nutrition and health. The PL mixture, rich in PC and polyunsaturated FAs, offers an interesting alternative source of high value-added marine lecithin.

  6. Bivalves: From individual to population modelling

    Science.gov (United States)

    Saraiva, S.; van der Meer, J.; Kooijman, S. A. L. M.; Ruardij, P.

    2014-11-01

    An individual based population model for bivalves was designed, built and tested in a 0D approach, to simulate the population dynamics of a mussel bed located in an intertidal area. The processes at the individual level were simulated following the dynamic energy budget theory, whereas initial egg mortality, background mortality, food competition, and predation (including cannibalism) were additional population processes. Model properties were studied through the analysis of theoretical scenarios and by simulation of different mortality parameter combinations in a realistic setup, imposing environmental measurements. Realistic criteria were applied to narrow down the possible combination of parameter values. Field observations obtained in the long-term and multi-station monitoring program were compared with the model scenarios. The realistically selected modeling scenarios were able to reproduce reasonably the timing of some peaks in the individual abundances in the mussel bed and its size distribution but the number of individuals was not well predicted. The results suggest that the mortality in the early life stages (egg and larvae) plays an important role in population dynamics, either by initial egg mortality, larvae dispersion, settlement failure or shrimp predation. Future steps include the coupling of the population model with a hydrodynamic and biogeochemical model to improve the simulation of egg/larvae dispersion, settlement probability, food transport and also to simulate the feedback of the organisms' activity on the water column properties, which will result in an improvement of the food quantity and quality characterization.

  7. The endemic mollusks reveal history of the long-lived Pliocene Lake Slavonia in NW Croatia

    Science.gov (United States)

    Mandic, Oleg; Kurečić, Tomislav; Neubauer, Thomas A.; Harzhauser, Mathias

    2015-04-01

    The present investigation deals with the fossil mollusk record of the long-lived Pliocene Lake Slavonia settled in the southern Pannonian Basin. The samples originate from Vukomeričke gorice, a low hill-range situated north of the Kupa River in the area between the towns of Zagreb, Sisak and Karlovac in NW Croatia. Representing the SW margin of the Lake Slavonia the freshwater deposits alternate there with the alluvial series, providing altogether about 400-m-thick, Pliocene continental succession, known in literature by informal name Paludina beds (acc. to a junior synonym of Viviparus). The endemic fauna of the Lake Slavonia became particularly well-known in the late 19th century after Melchior Neumayr demonstrated that the gradual evolutionary change of the mollusk phenotypes toward more complex morphology represents a function of adaptation to environmental change in the paleolake. Even Charles Darwin commented that result as by far the best case which I have ever met with, showing the direct influence of the conditions of life on the organization. The deposition in the Lake Slavonia (~4.5 to ~1.8 Ma) coincides with the Pliocene Climate Optimum (PCO), but captures also the transition into the Pleistocene climate marked by the initial Ice Age pulse at 2.59 Ma. The increase of polar temperatures resulted during PCO in a significant melting of the ice caps leading to a global sea level rise tentatively getting up to 25 m higher than today. Coincidence of the climate and geodynamic settings in southeastern Europe provided conditions supporting extended settlement of lacustrine environments including Lake Slavonia, Lake Kosovo, Lake Transylvania and Lake Dacia, all characterized by explosive adaptive radiations of viviparid snails. In particular, the latter adaptive radiations resulted in the regional phylostratigraphy of Lake Slavonia Viviparus species enabling excellent stratigraphic control for the investigated deposits. Hence, based on this evidence, the

  8. Nitrogen Isotope Analyses in Mollusk Shell: Applications to Environmental Sciences and Archaeology.

    Science.gov (United States)

    Andrus, C. F. T.; Bassett, C.; Black, H. D.; Payne, T. N.

    2017-12-01

    Several recent studies demonstrate that nitrogen isotope analysis of the organic fraction of mollusk shells can serve as a proxy for anthropogenic environmental impacts, including sewage input into estuaries. Analysis of δ15N in shells from archaeological sites permits construction of time-series proxy data from the present day to pre-industrial times, yielding insight into the history of some human environmental influences such as waste input and land use changes. Most such studies utilize a single bulk analysis per valve, combining shell material grown over time periods of one or more years. However, large, fast-growing species (e.g. some scallops and abalone) may permit sub-annual sampling, potentially yielding insight into seasonal processes. Such sclerochronological sampling of archaeological shells may enable researchers to detect variation at a finer temporal scale than has been attempted to date, which in turn may facilitate analysis of seasonal resource procurement strategies and related actions. This presentation will incorporate new and published data from the Atlantic, Pacific and Gulf of Mexico coasts of North America to assess how sclerochronological δ15N data can be useful to better understand pre-industrial human-environmental interaction and change, and also address diagenesis and other preservational concerns commonly found in archaeological samples.

  9. Comparative sensitivity of European native (Anodonta anatina) and exotic (Corbicula fluminea) bivalves to mercury

    Science.gov (United States)

    Oliveira, Patrícia; Lopes-Lima, Manuel; Machado, Jorge; Guilhermino, Lúcia

    2015-12-01

    Pollution is believed to be an important factor modulating the competition between exotic invasive bivalves and their native competitors. Thus, the objective of the present study was to compare the sensitivity of the European native Anodonta anatina and the exotic invasive species Corbicula fluminea to mercury, a ubiquitous environmental contaminant of high concern. In laboratory acute bioassays, adult organisms of both species were exposed independently to mercury for 96 h (31-500 μg/L). The criteria indicative of toxicity were mortality and biomarkers of oxidative stress and damage, neurotoxicity, and energy production changes. Mercury induced mortality in A. anatina (72 h-LC10 and 72 h-LC50 of 14.0 μg/L and 49.6 μg/L, respectively) but not in C. fluminea. The ability of C. fluminea to maintaining the shell closed for considerable periods of time when exposed to high concentrations of mercury and the effective activation (up to 63 μg/L) of mechanisms against the oxidative stress caused by mercury may have contributed to its relatively low sensitivity. In the range of concentrations tested, mercury had no significant effects on the other parameters analysed in C. fluminea. Overall, the findings of the present study, suggest that in real scenarios of competition between C. fluminea and A. anatina populations, the presence of mercury may modulate the process, acting in favour of the exotic species because it is less sensitive to this environmental contaminant than the native bivalve. The results of the present study highlight the need of further investigation on the effects of mercury on the competition between exotic invasive species and their native competitors, especially the effects potentially induced by long-term exposure to low concentrations of this metal, the mechanisms involved in the tolerance to mercury-induced stress, and the potential post-exposure recovery of both exotic invasive and native bivalves. This knowledge is most important for

  10. Soundscapes and Larval Settlement: Larval Bivalve Responses to Habitat-Associated Underwater Sounds.

    Science.gov (United States)

    Eggleston, David B; Lillis, Ashlee; Bohnenstiehl, DelWayne R

    2016-01-01

    We quantified the effects of habitat-associated sounds on the settlement response of two species of bivalves with contrasting habitat preferences: (1) Crassostrea virginicia (oyster), which prefers to settle on other oysters, and (2) Mercenaria mercenaria (clam), which settles on unstructured habitats. Oyster larval settlement in the laboratory was significantly higher when exposed to oyster reef sound compared with either off-reef or no-sound treatments. Clam larval settlement did not vary according to sound treatments. Similar to laboratory results, field experiments showed that oyster larval settlement in "larval housings" suspended above oyster reefs was significantly higher compared with off-reef sites.

  11. Metabolites of saxitoxin analogues in bivalves contaminated by Gymnodinium catenatum.

    Science.gov (United States)

    Vale, Paulo

    2010-01-01

    Bivalve metabolites of saxitoxin analogues, not present in microalgae, were recently described as an important toxin fraction in mussels contaminated by Alexandrium tamarense. These possess very low fluorescence, and require mass spectrometry detection. HILIC-MS was implemented to look for these metabolites in bivalves contaminated during Gymnodinium catenatum blooms at the Portuguese coast. The presence of M1 was tentatively identified in several bivalves, ranging from estuarine (Mytilus galloprovinciallis, Cerastoderma edule and Ruditapes decussatus) to oceanic habitat (Donax trunculus and Ensis spp.). It was hypothesized that M1 could contribute to an important fraction of the profile of STX analogues. M1 was more abundant in estuarine bivalves that retain longer PSP toxins, in the following order: mussels>cockles>clams. These data highlight that the study by fluorimetry alone of the carbamoyl, N-sulfocarbamoyl, and decarbamoyl families is manifestly insufficient to fully understand toxin dynamics in bivalves feeding on G. catenatum without a proper study of hydroxybenzoate and hydroxylated M-toxins.

  12. Zoochorous dispersal of freshwater bivalves: an overlooked vector in biological invasions?

    Directory of Open Access Journals (Sweden)

    Coughlan Neil E.

    2017-01-01

    Full Text Available Vectors that underpin the natural dispersal of invasive alien species are frequently unknown. In particular, the passive dispersal (zoochory of one organism (or propagule by another, usually more mobile animal, remains poorly understood. Field observations of the adherence of invasive freshwater bivalves to other organisms have prompted us to assess the importance of zoochory in the spread of three prolific invaders: zebra mussel Dreissena polymorpha; quagga mussel Dreissena bugensis; and Asian clam Corbicula fluminea. An extensive, systematic search of the literature was conducted across multiple on-line scientific databases using various search terms and associated synonyms. In total, only five publications fully satisfied the search criteria. It appears that some fish species can internally transport viable adult D. polymorpha and C. fluminea specimens. Additionally, literature indicates that veligers and juvenile D. polymorpha can adhere to the external surfaces of waterbirds. Overall, literature suggests that zoochorous dispersal of invasive bivalves is possible, but likely a rare occurrence. However, even the establishment of a few individuals (or a single self-fertilising C. fluminea specimen can, over-time, result in a substantial population. Here, we highlight knowledge gaps, identify realistic opportunities for data collection, and suggest management protocols to mitigate the spread of invasive alien species.

  13. The quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897) – another Ponto-Caspian dreissenid bivalve in the southern Baltic catchment: the first record from the Szczecin Lagoon

    OpenAIRE

    Adam Woźniczka; Brygida Wawrzyniak-Wydrowska; Teresa Radziejewska; Anna Skrzypacz

    2016-01-01

    In 2014, a non-indigenous dreissenid bivalve, the quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897) was for the first time recorded in the Szczecin Lagoon. This was also the first record of the species in the Baltic Sea catchment. The quagga mussel was found to accompany the zebra mussel (Dreissena polymorpha), a non-indigenous bivalve already firmly established in the Lagoon. As indicated by the new immigrant's estimated abundance (4000.0 ± 355.44 ind. m−2) and the zebra mussel ...

  14. Predation and habitat modification synergistically interact to control bivalve recruitment on intertidal mudflats

    NARCIS (Netherlands)

    van der Heide, T.; Tielens, E.; van der Zee, E.M.; Weerman, E.J.; Holthuijsen, S.; Eriksson, B.K.; Piersma, T.; van de Koppel, J.; Olff, H.

    2014-01-01

    Bivalves are key components of coastal ecosystems because they link pelagic and benthic food webs, and shape the landscape through habitat modification. Nevertheless, many bivalve stocks have dramatically declined, and recruitment failure due to (anthropogenically-) increased predation by

  15. Predation and habitat modification synergistically interact to control bivalve recruitment on intertidal mudflats

    NARCIS (Netherlands)

    van der Heide, Tjisse; Tielens, Elske; van der Zee, Els; Weerman, Ellen J.; Holthuijsen, Sander; Eriksson, Britas Klemens; Piersma, Theun; van de Koppel, Johan; Olff, Han

    Bivalves are key components of coastal ecosystems because they link pelagic and benthic food webs, and shape the landscape through habitat modification. Nevertheless, many bivalve stocks have dramatically declined, and recruitment failure due to (anthropogenically-) increased predation by

  16. 76 FR 65200 - Risk Assessment on Norovirus in Bivalve Molluscan Shellfish: Request for Comments and for...

    Science.gov (United States)

    2011-10-20

    ... transmission of norovirus from infected or ill food workers in food manufacturing or retail establishments to... Molluscan Shellfish Contamination Levels During Food Preparation and Bivalve Molluscan Shellfish Consumption... and other factors influencing bivalve molluscan shellfish contamination levels during food preparation...

  17. Patterns of species richness in sandy beaches of South America ...

    African Journals Online (AJOL)

    The middle shore is primarily occupied by cirolanids and bivalves, and hippid crabs, bivalves and amphipods dominate the lower beach. Generally, species richness increases from upper to lower beach levels. Studies carried out on exposed sandy beaches of south-central Chile (ca. 40°S) show that different beach states ...

  18. Biosorption of divalent Pb, Cd and Zn on aragonite and calcite mollusk shells

    Energy Technology Data Exchange (ETDEWEB)

    Du Yang; Lian Fei [Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Zhu Lingyan, E-mail: zhuly@nankai.edu.cn [Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China)

    2011-07-15

    The potential of using mollusk shell powder in aragonite (razor clam shells, RCS) and calcite phase (oyster shells, OS) to remove Pb{sup 2+}, Cd{sup 2+} and Zn{sup 2+} from contaminated water was investigated. Both biogenic sorbents displayed very high sorption capacities for the three metals except for Cd on OS. XRD, SEM and XPS results demonstrated that surface precipitation leading to crystal growth took place during sorption. Calcite OS displayed a remarkably higher sorption capacity to Pb than aragonite RCS, while the opposite was observed for Cd. However, both sorbents displayed similar sorption capacities to Zn. These could be due to the different extent of matching in crystal lattice between the metal bearing precipitate and the substrates. The initial pH of the solution, sorbent's dosage and grain size affected the removal efficiency of the heavy meals significantly, while the organic matter in mollusk shells affected the removal efficiency to a lesser extent. - Highlights: > Mollusk shells display high removal efficiency to heavy metals in contaminated water. > Surface precipitation leading to crystal growth takes place during the sorption. > Crystal structure similarity between precipitates and substrates affects the sorption. > pH, sorbent dosage and grain size of adsorbent affects the removal efficiency. > Organic matter in mollusk shells affects the removal efficiency to a less extent. - Mollusk shells display high sorption ability to heavy metals and crystal structure similarity between precipitates and substrates affects the sorption.

  19. Evaluation of the efficacy of twelve mitochondrial protein-coding genes as barcodes for mollusk DNA barcoding.

    Science.gov (United States)

    Yu, Hong; Kong, Lingfeng; Li, Qi

    2016-01-01

    In this study, we evaluated the efficacy of 12 mitochondrial protein-coding genes from 238 mitochondrial genomes of 140 molluscan species as potential DNA barcodes for mollusks. Three barcoding methods (distance, monophyly and character-based methods) were used in species identification. The species recovery rates based on genetic distances for the 12 genes ranged from 70.83 to 83.33%. There were no significant differences in intra- or interspecific variability among the 12 genes. The monophyly and character-based methods provided higher resolution than the distance-based method in species delimitation. Especially in closely related taxa, the character-based method showed some advantages. The results suggested that besides the standard COI barcode, other 11 mitochondrial protein-coding genes could also be potentially used as a molecular diagnostic for molluscan species discrimination. Our results also showed that the combination of mitochondrial genes did not enhance the efficacy for species identification and a single mitochondrial gene would be fully competent.

  20. Artificially evolved functional shell morphology of burrowing bivalves

    DEFF Research Database (Denmark)

    Germann, D. P.; Schatz, W.; Hotz, Peter Eggenberger

    2014-01-01

    dimensional (3D) objects, the first ever artificial evolution of a physical bivalve shell was performed. The result was a vertically flattened shell occupying only the top sediment layers. Insufficient control of the sediment was the major limitation of the setup and restricted the significance of the results......, there are almost no studies experimentally testing their dynamic properties. To investigate the functional morphology of the bivalve shell, we employed a synthetic methodology and built an experimental setup to simulate the burrowing process. Using an evolutionary algorithm and a printer that prints three...

  1. Modeling the carbon isotope composition of bivalve shells (Invited)

    Science.gov (United States)

    Romanek, C.

    2010-12-01

    The stable carbon isotope composition of bivalve shells is a valuable archive of paleobiological and paleoenvironmental information. Previous work has shown that the carbon isotope composition of the shell is related to the carbon isotope composition of dissolved inorganic carbon (DIC) in the ambient water in which a bivalve lives, as well as metabolic carbon derived from bivalve respiration. The contribution of metabolic carbon varies among organisms, but it is generally thought to be relatively low (e.g., 90%) in the shells from terrestrial organisms. Because metabolic carbon contains significantly more C-12 than DIC, negative excursions from the expected environmental (DIC) signal are interpreted to reflect an increased contribution of metabolic carbon in the shell. This observation contrasts sharply with modeled carbon isotope compositions for shell layers deposited from the inner extrapallial fluid (EPF). Previous studies have shown that growth lines within the inner shell layer of bivalves are produced during periods of anaerobiosis when acidic metabolic byproducts (e.g., succinic acid) are neutralized (or buffered) by shell dissolution. This requires the pH of EPF to decrease below ambient levels (~7.5) until a state of undersaturation is achieved that promotes shell dissolution. This condition may occur when aquatic bivalves are subjected to external stressors originating from ecological (predation) or environmental (exposure to atm; low dissolved oxygen; contaminant release) pressures; normal physiological processes will restore the pH of EPF when the pressure is removed. As a consequence of this process, a temporal window should also exist in EPF at relatively low pH where shell carbonate is deposited at a reduced saturation state and precipitation rate. For example, EPF chemistry should remain slightly supersaturated with respect to aragonite given a drop of one pH unit (6.5), but under closed conditions, equilibrium carbon isotope fractionation

  2. Growth rates and geochemical proxies in Late Campanian bivalves - New insights from micro-X-ray Fluorescence mapping and numerical growth modelling

    Science.gov (United States)

    de Winter, Niels; Goderis, Steven; van Malderen, Stijn; Vanhaecke, Frank; Claeys, Philippe

    2017-04-01

    Understanding the Late Cretaceous greenhouse climate is of vital importance for understanding present and future climate change. While a lot of good work has been done to reconstruct climate in this interesting period, most paleoclimatic studies have focused on long-term climate change[1]. Alternatively, multi-proxy records from marine bivalves provide us with a unique opportunity to study past climate on a seasonal scale. However, previous fossil bivalve studies have reported ambiguous results with regard to the interpretation of trace element and stable isotope proxies in marine bivalve shells[2]. One major problem in the interpretation of such records is the bivalve's vital effect and the occurrence of disequilibrium fractionation during bivalve growth. Both these problems are linked to the annual growth cycle of marine bivalves, which introduces internal effects on the incorporation of isotopes and trace elements into the shell[3]. Understanding this growth cycle in extinct bivalves is therefore of great importance for the interpretation of seasonal proxy records in their shells. In this study, three different species of extinct Late Campanian bivalves (two rudist species and one oyster species) that were found in the same stratigraphic interval are studied. Micro-X-Ray Fluorescence line scanning and mapping of trace elements such as Mg, Sr, S and Zn, calibrated by LA-ICP-MS measurements, is combined with microdrilled stable carbon and oxygen isotope analysis on the well-preserved part of the shells. Data of this multi-proxy study is compared with results from a numerical growth model written in the open-source statistics package R[4] and based on annual growth increments observed in the shells and shell thickness. This growth model is used together with proxy data to reconstruct rates of trace element incorporation into the shell and to calculate the mass balance of stable oxygen and carbon isotopes. In order to achieve this goal, 2D mapping of bivalve shell

  3. Ecological studies of wood-boring bivalves in the vicinity of the Oyster Creek Nuclear Generating Station. Progress report Sep-Nov 81

    International Nuclear Information System (INIS)

    Hoagland, K.E.; Crocket, L.

    1982-06-01

    The species composition, distribution, and population dynamics of wood-boring bivalves are being studied in the vicinity of the Oyster Creek Nuclear Generating Station, Barnegat Bay, New Jersey. Untreated wood test panels are used to collect organisms at 12 stations. Physiological tolerances of 3 species are also under investigation in the laboratory. Competition among the species is being analyzed. In the fall of 1981, Teredo bartschi remained in Oyster Creek despite continuous prolonged outages of the Oyster Creek Nuclear Generating Station

  4. Assessing phototoxicity of petroleum using the bivalve Mulinia lateralis and the mysid Mysidopsis bahia

    International Nuclear Information System (INIS)

    Pelletier, M.; Champlin, D.; Burgess, R.; Ho, K.; Kuhn-Hines, A.

    1995-01-01

    One of the major inputs of PAHs in the marine environment is petroleum products. A large and often catastrophic source of petroleum is an oil spill, which releases concentrated quantities of PAHs into the water column. Intermediate molecular weight compounds remain in the water column for a relatively extended length of time. These compounds include phototoxic PAHs such as anthracene, fluoranthene, pyrene, and their substituted derivatives. Assessments of the environmental impact of marine oil spills have not included phototoxicity tests using pelagic larvae of benthic invertebrates. In this study, the photoreactive toxicity of individual PAHs, including anthracene, pyrene, and fluoranthene, were determined using the bivalve, Mulinia lateralis and the mysid, Mysidopsis bahia. Ultraviolet light exposures increased toxicity relative to fluorescent light for both species but a particularly dramatic response was seen using M. lateralis embryos. This species was relatively insensitive when exposed under fluorescent lights, but exhibited up to a 4,000 fold increase in toxicity under ultraviolet lights. Exposures with different types of petroleum (e.g., fuel oil number-sign 2 and crude oil) under fluorescent and ultraviolet light will demonstrate the utility of this bivalve and mysid for assessing oil spill-related acute and sublethal toxicity in the marine environment

  5. Harmful algal blooms and Vibrio spp. association in fishing and marine farming areas of mollusk bivalves in Sechura and Pisco bays, Peru

    Directory of Open Access Journals (Sweden)

    Rita Orozco

    2017-04-01

    Full Text Available Between February 2010 and May 2014, 22 surveys in Pisco and 16 in Sechura were conducted; both are major areas for shellfish production and mariculture in Peru. The incidence of Vibrio in seawater was monitored during algal blooms and in their absence. Environmental parameters such as temperature and nutrients were measured. In Sechura, Pseudo-nitzschia seriata and Protoperidinium depressum caused algal blooms and were dominant throughout the evaluation period. The temperatures in this area ranged from 21.8 to 25.3 °C. In Pisco, the harmful algal bloom-forming Akashiwo sanguinea, Messodinium rubrum, and Prorocentrum minimum and the dinoflagellate Cochlodinium polikrykoides were most prevalent. Harmful algal blooms occurred when temperatures were between 17.1 and 23.3 °C, with phosphates ranging 1.22 - 6.85 µM and nitrates 0.15 - 7.85 µM. In May 2012, the dinoflagellate Alexandrium peruvianum caused an algal bloom, with temperatures ranging 18.0 to 23.2 °C, phosphate values from 0.73 to 11.56 µM, and nitrates from 0.76 to 9.81 µM. Coliforms were low, < 2 - 23 MPN/100 ml, in both bays throughout the study period. Vibrio alginolyticus was the dominant Vibrio spp. predominated in both bays, while V. vulnificus and V. parahaemolyticus were detected in Pisco, where warmer sea temperatures are common and severe infections cases by seafood ingestion has been associated with a pathogen V. parahaemolyticus.

  6. Bioaccumulation Potential of Contaminants from Bedded and Suspended Oakland Harbor Deepening Project Sediments to San Francisco Bay Flatfish and Bivalve Mollusks

    Science.gov (United States)

    1994-08-01

    potential TBT tributyltin TCDD tetrachlorod ibenzo-p-dioxin TeBT tetrabutyltin TEF toxicity equivalency factor TOC total organic carbon TSS total...these sediments and in the four experiments to be discussed below include 15 PAHs; the metals Cd, Cr, and Hg; tributyltin ( TBT ) and dibutyltin (DBT); and...4,4’DDT. b. Aroclor 1254 ................ B6 Figure B 11. Contaminant concentrations in sediments. a. Dibutyltin. b. Tributyltin

  7. 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.

  8. Acute sensitivity of freshwater mollusks and commonly tested invertebrates to select chemicals with different toxic models of action

    Science.gov (United States)

    Previous studies indicate that freshwater mollusks are more sensitive than commonly tested organisms to some chemicals, such as copper and ammonia. Nevertheless, mollusks are generally under-represented in toxicity databases. Studies are needed to generate data with which to comp...

  9. Organisms associated with the sandy-beach bivalve Donax serra ...

    African Journals Online (AJOL)

    57: 134-136. BROWN, AC. & WEBB, S.c. 1994. Organisms associated \\.,.,ith burrowing whelks of the genus Bullia. S Afr. 1. Zool. 29: 144-151. BROWN, A.C., STENTON-DOZEY, J.~.E. & TRUEMAN, E.R.. 1989. Sandy-beach bivalves and gastropods; a comparison between Donax serra and Ruilia digitalis. Adv. mar. Bioi. 25:.

  10. Seasonal variability in somatic and reproductive investment of the bivalve

    NARCIS (Netherlands)

    Santos, S.; Cardoso, J.F.M.F.; Carvalho, C.; Luttikhuizen, P.C.; van der Veer, H.W.

    2011-01-01

    Monthly investment in soma and gonads in the bivalve Scrobicularia plana is described for three populations along its distributional range: Minho estuary, Portugal; Westerschelde estuary, The Netherlands and Buvika estuary, Norway. Seasonal cycles in body mass (BMI), somatic mass (SMI) and

  11. Abundance, biomass and caloric content of Chukchi Sea bivalves and association with Pacific walrus (Odobenus rosmarus divergens) relative density and distribution in the northeastern Chukchi Sea

    Science.gov (United States)

    Young, Jordann K.; Black, Bryan A.; Clarke, Janet T.; Schonberg, Susan V.; Dunton, Kenneth H.

    2017-10-01

    The northeastern Chukchi Sea is a shallow subarctic shelf ecosystem that supports a substantial benthic infaunal community of which bivalves are a major component. We assessed the patterns in population abundance, biomass, and caloric content of ten dominant bivalve taxa in relation to the distribution of the upper trophic level consumer Pacific walrus (Odobenus rosmarus divergens). Bivalves were collected over four cruises in the northeastern Chukchi Sea (2009, 2010, 2012, 2013). Our samples were largely dominated by calorie-dense, deposit-feeding species, including Macoma spp., Ennucula tenuis, Nuculana spp. and Yoldia spp. Weight-frequency distributions were strongly right-skewed for most taxa, though some showed evidence of a bimodal distribution. Caloric densities as measured through bomb calorimetry significantly differed among taxa (ANOVA F = 32.57, df = 9, p-valueanimal wet weight was found to be a reliable predictor of whole animal caloric content. Bivalve populations and peak caloric densities were centered on and to the southeast of Hanna Shoal, which coincided with peak Pacific walrus relative density (walruses per km surveyed) from July through October. Significant differences in mean caloric values were found between areas with and without walruses present (student's t-test, t=-2.9088, df = 252.24, p-value = 0.003952), as well as between areas with low and high walrus relative densities in the pooled annual dataset and in each individual month except October (ANOVA, p-value<0.05). The high-calorie deposit feeders that dominate these bivalve communities preferentially consume food sources, such as sea ice algae, that are likely to be affected by shifting sea ice dynamics. As such, continued warming has the potential to alter bivalve communities in the northeastern Chukchi Sea, which may have profound implications for upper trophic levels.

  12. Contamination in sediments, bivalves and sponges of McMurdo Sound, Antarctica

    International Nuclear Information System (INIS)

    Negri, Andrew; Burns, Kathryn; Boyle, Steve; Brinkman, Diane; Webster, Nicole

    2006-01-01

    This study examined the concentrations of total hydrocarbons (THC), polychlorinated biphenyls (PCB), polyaromatic hydrocarbons (PAH), and trace metals (Cu, Zn, Cd, Pb, Hg and As) in marine sediments off Scott Base (NZ) and compared them with sediments near the highly polluted McMurdo Station (US) as well as less impacted sites including Turtle Rock and Cape Evans. The Antarctic mollusc, Laternula elliptica and three common sponge species were also analysed for trace metals. The mean THC concentration in sediments from Scott Base was 3 fold higher than the pristine site, Turtle Rock, but 10 fold lower than samples from McMurdo Station. McMurdo Station sediments also contained the highest concentrations of PAHs, PCBs and the trace metals, Cu, Zn, Pb, Cd and Hg. Copper was significantly higher in bivalves from McMurdo Station than other sites. Trace metal concentrations in sponges were generally consistent within sites but no spatial patterns were apparent. - Analyses of Antarctic marine sediments, bivalves and sponges revealed strong PAH, PCB and trace metal gradients in McMurdo Sound

  13. Traces (ichnospecies Oichnus paraboloides of predatory gastropods on bivalve shells from the Seogwipo Formation, Jejudo, Korea

    Directory of Open Access Journals (Sweden)

    Dal-Yong Kong

    2015-12-01

    Full Text Available Circular to subcircular drill holes were identified on the bivalve shells collected from the Seogwipo Formation, Jejudo, Korea. A great majority of the drill holes (>70% were found on the surfaces of a bivalve species Glycymeris rotunda. They are characterized by a beveled sharp edge and paraboloid in cross section with larger outer borehole diameter (OBD; mean 4.21 mm and smaller inner borehole diameter (mean 2.94 mm. Walls of the drill holes are generally smooth, and walls ornamented with etched relief-like structures were also recognized. A slightly raised central boss observed in an incomplete specimen may indicate a failure of predator’s attack. All drill holes collected are classified as a single ichnospecies Oichnus paraboloides Bromley, 1981. They are interpreted as boring traces produced by predatory gastropods, particularly naticid gastropods. Most O. paraboloides boreholes are observed in the central area of shell surfaces; a few boreholes lie marginally, which may reflect a borehole-site selectivity. No correlation between size of prey (shell height and size of predator (OBD is recognized. It is likely, however, that drilled shells of about 30 mm in height represent optimal prey size for naticid predators that lived in a benthic Seogwipo community.

  14. Contamination in sediments, bivalves and sponges of McMurdo Sound, Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Negri, Andrew [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia)]. E-mail: a.negri@aims.gov.au; Burns, Kathryn [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia); Boyle, Steve [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia); Brinkman, Diane [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia); Webster, Nicole [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia); Biological Sciences, University of Canterbury, Christchurch (New Zealand)

    2006-10-15

    This study examined the concentrations of total hydrocarbons (THC), polychlorinated biphenyls (PCB), polyaromatic hydrocarbons (PAH), and trace metals (Cu, Zn, Cd, Pb, Hg and As) in marine sediments off Scott Base (NZ) and compared them with sediments near the highly polluted McMurdo Station (US) as well as less impacted sites including Turtle Rock and Cape Evans. The Antarctic mollusc, Laternula elliptica and three common sponge species were also analysed for trace metals. The mean THC concentration in sediments from Scott Base was 3 fold higher than the pristine site, Turtle Rock, but 10 fold lower than samples from McMurdo Station. McMurdo Station sediments also contained the highest concentrations of PAHs, PCBs and the trace metals, Cu, Zn, Pb, Cd and Hg. Copper was significantly higher in bivalves from McMurdo Station than other sites. Trace metal concentrations in sponges were generally consistent within sites but no spatial patterns were apparent. - Analyses of Antarctic marine sediments, bivalves and sponges revealed strong PAH, PCB and trace metal gradients in McMurdo Sound.

  15. Accumulation of butyl- and phenyltin compounds in starfish and bivalves from the coastal environment of Korea

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Won Joon [Southern Coastal Environment Research Division, Korea Ocean Research and Development Institute, Jangmok-myon 391, Geoje 656-830 (Korea, Republic of)]. E-mail: wjshim@kordi.re.kr; Yim, Un Hyuk [Southern Coastal Environment Research Division, Korea Ocean Research and Development Institute, Jangmok-myon 391, Geoje 656-830 (Korea, Republic of); Kim, Nam Sook [Southern Coastal Environment Research Division, Korea Ocean Research and Development Institute, Jangmok-myon 391, Geoje 656-830 (Korea, Republic of); Hong, Sang Hee [Southern Coastal Environment Research Division, Korea Ocean Research and Development Institute, Jangmok-myon 391, Geoje 656-830 (Korea, Republic of); Oh, Jae Ryoung [Southern Coastal Environment Research Division, Korea Ocean Research and Development Institute, Jangmok-myon 391, Geoje 656-830 (Korea, Republic of); Jeon, Joong Kyun [Department of Marine Bioscience and Technology, Kangnung National University, Kangnung 210-702 (Korea, Republic of); Okamura, Hideo [Laboratory of Marine Environment Management, Kobe University Mercantile Marine, Fukaeminami 5-1-1, Highshinada, Kobe 658-0022 (Japan)

    2005-02-01

    Triphenyltin (TPT) and tributyltin (TBT) concentrations were determined in two starfish species (Asteria pectinifera and Asterias amurensis), bivalves (Crassostrea gigas or Mytilus edulis), and seawater samples from sites around the coasts of Korea. Both TPT and TBT concentrations in starfish ranged from 8 to 1560 ng/g and from <2 to 797 ng/g as Sn on a dry weight basis, respectively. TPT concentration accounted for 75.4% and 86.4% of total phenyltin concentration in A. pectinifera and A. amurensis, respectively, while monobutyltin, a degradation product of TBT, accounted for 86.3% and 57.2% of total butyltin, respectively. Triphenyltin concentrations in A. pectinifera were significantly correlated to water and bivalve TPT concentrations, which implies that dietary uptake of TPT from contaminated prey as well as direct uptake from surrounding water contribute to TPT body residues in the starfish. Starfish could be target organisms for monitoring TPT compound in the marine environment, due to their high accumulation and low degradation capacity towards TPT. - Starfish are effective organisms for monitoring phenyltin contamination in the marine environment.

  16. Accumulation of butyl- and phenyltin compounds in starfish and bivalves from the coastal environment of Korea

    International Nuclear Information System (INIS)

    Shim, Won Joon; Yim, Un Hyuk; Kim, Nam Sook; Hong, Sang Hee; Oh, Jae Ryoung; Jeon, Joong Kyun; Okamura, Hideo

    2005-01-01

    Triphenyltin (TPT) and tributyltin (TBT) concentrations were determined in two starfish species (Asteria pectinifera and Asterias amurensis), bivalves (Crassostrea gigas or Mytilus edulis), and seawater samples from sites around the coasts of Korea. Both TPT and TBT concentrations in starfish ranged from 8 to 1560 ng/g and from <2 to 797 ng/g as Sn on a dry weight basis, respectively. TPT concentration accounted for 75.4% and 86.4% of total phenyltin concentration in A. pectinifera and A. amurensis, respectively, while monobutyltin, a degradation product of TBT, accounted for 86.3% and 57.2% of total butyltin, respectively. Triphenyltin concentrations in A. pectinifera were significantly correlated to water and bivalve TPT concentrations, which implies that dietary uptake of TPT from contaminated prey as well as direct uptake from surrounding water contribute to TPT body residues in the starfish. Starfish could be target organisms for monitoring TPT compound in the marine environment, due to their high accumulation and low degradation capacity towards TPT. - Starfish are effective organisms for monitoring phenyltin contamination in the marine environment

  17. Seagrass mollusks as a model group for paleoecological and paleodiversity studies

    NARCIS (Netherlands)

    Reich, S.

    2014-01-01

    Today’s global marine diversity hotspot is located in the Indo-Malayan region of the Indo-West Pacific. Numerous groups of marine organisms including mollusks contribute to this high taxonomic richness that is thought to have originated in the Early Neogene. Because the available fossil data to

  18. The Relationship between Mollusks and Oxygen Concentrations in Todos Santos Bay, Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    J. Gabriel Kuk-Dzul

    2016-01-01

    Full Text Available This study describes the relationship between mollusks, physicochemical properties of seawater, and sediments under natural conditions of low impact. Thirty-nine stations were sampled in October 1994 using a Van Veen grab (0.1 m−2. Temperature, salinity, and dissolved oxygen (DO concentrations of bottom water were obtained with a CTD. Organic matter content and sediment grain analysis were determined. A total of 836 mollusks were collected. Gastropoda was the most abundant (52% and diverse class with 27 genera, followed by Bivalvia with eight genera and Scaphopoda with only one genus. According to CCA analysis, dominant mollusks were significantly related with high DO concentrations. Donax, Natica, Acteocina, Bulla, Anachis, Odostomia, and Crucibulum can be classified as sensitive genera because they were found mainly in high oxygen concentrations (3.1–5.6 mL L−1; on the other hand, Cardiomya, Nuculana, Laevicardium, Chione, Truncatella, and Dentalium can be classified as tolerant genera (1.0–5.6 mL L−1. Todos Santos Bay hosts a diverse malacological fauna (36 genera; our results show that the dominant genera were mainly related to high dissolved oxygen concentrations. Mollusks can be a useful tool in environmental monitoring programs related with oxygen depletion in coastal areas.

  19. Heavy metal pollution in marine mollusks from the coastal waters of ...

    African Journals Online (AJOL)

    Studies of heavy metals in four marine mollusks, Thais haemastoma, T. nodosa, Nerita senegalensis and P. perna, have been conducted. This involved the assessment of levels of heavy metal pollution from point sources in the Korle lagoon and the determination of the extent to which these metals are transported by ...

  20. Element availability of bivalve with symbiotic zooxanthellae in coral sea area as studied by multielement profiling analysis

    Science.gov (United States)

    Itoh, A.; Kabe, N.

    2008-12-01

    In coral sea, a characteristic ecosystem is formed by many kinds of marine animals and plants, although seawater is uneutrophic. This may be explained by the fact that various chemical species with bioessentiality are effectively taken and used by lower animals and plants in coral sea area. A symbiotic relationship often found among different animals and plants in this area is considered to be working as one of such processes. However, the specific bioavailability of the elements for the marine animals and plants in coral reef area has not been studied from the viewpoints of trace and ultratrace elements. It is found by the present authors that bivalve with symbiotic zooxanthellae (Tridacna crocea) living on coral reef had relatively higher bio- accumulation factors for many bio-essential elements than other kinds of bivalves, although they live in the uneutrophic sea area. The present authors focused on Tridacna crocea as one of the symbiotic animals. Thus, in the present study, at first, multielement determination of major-to-ultratrace elements (about 20 elements) in each organ of Tridacna crocea with symbiotic zooxanthellae, were carried out by ICP-AES, ICP- MS, and CHN coder. At Second, the specific bioavailability of trace and ultratrace elements in Tridacna crocea was discussed on the multielement data for seawater, seaweeds, and other bivalves in coral sea area.

  1. Análisis de endemismo de moluscos dulceacuícolas de Chile Endemism analysis of Chilean freshwater mollusks

    Directory of Open Access Journals (Sweden)

    CARMEN FUENTEALBA

    2010-06-01

    Full Text Available La diversidad geológica y climática de Chile continental permite la diferenciación de una gran variedad de ecosistemas terrestres y acuáticos. La evidencia de los actuales patrones de distribución de especies dulceacuícolas sugiere en gran medida una relación con las glaciaciones del Pleistoceno y algunos eventos tectónicos postglaciales que afectaron la hidrografía del país. Las especies de moluscos dulceacuícolas en Chile, a diferencia de las especies marinas, han sido escasamente valoradas, a pesar del papel que cumple un importante número de ellas en los ecosistemas. Actualmente no existen estudios biogeográficos que permitan establecer patrones distribucionales y los procesos que los condicionaron. Un análisis de parsimonia de endemismos (PAE y de riqueza de cinco zonas hidrográficas, basado en 75 especies de moluscos dulceacuícolas, sugiere la existencia de tres áreas biogeográficas: Norte (entre las latitudes 17°-33° S, Centro-Sur (33°-44° S y Sur (44°-56° S. La zona hidrográfica V (44°-56° S, incluida en el área Sur, posee el mayor porcentaje de endemismo (75 %, a diferencia de la zona hidrográfica III (17°-26° S, incluida en el área Centro-Norte, la cual registró el valor más bajo (42 %.The Chilean geological and climatic diversity allows the differentiation of a great variety of terrestrial and aquatic ecosystems. Evidence provided by distributional patterns of freshwater species suggests a correspondence with Pleistocene glaciations, and some post-glacial tectonic events that affected the hydrography of the country. The species of freshwater Chilean mollusks, unlike the marine species, have been undervalued. Currently there are no biogeographic studies that would allow identifying distribution patterns and the possible processes that shaped them. A parsimony analysis of endemicity (PAE and the richness of five hidrographic zones, based on 75 freshwater mollusk species, suggests the existence of three

  2. Subcellular compartmentalization of Cd and Zn in two bivalves. II. Significance of trophically available metal (TAM)

    Science.gov (United States)

    Wallace, W.G.; Luoma, S.N.

    2003-01-01

    This paper examines how the subcellular partitioning of Cd and Zn in the bivalves Macoma balthica and Potamocorbula amurensis may affect the trophic transfer of metal to predators. Results show that the partitioning of metals to organelles, 'enzymes' and metallothioneins (MT) comprise a subcellular compartment containing trophically available metal (TAM; i.e. metal trophically available to predators), and that because this partitioning varies with species, animal size and metal, TAM is similarly influenced. Clams from San Francisco Bay, California, were exposed for 14 d to 3.5 ??g 1-1 Cd and 20.5 ??g 1-1 Zn, including 109Cd and 65Zn as radiotracers, and were used in feeding experiments with grass shrimp Palaemon macrodatylus, or used to investigate the subcellular partitioning of metal. Grass shrimp fed Cd-contaminated P. amurensis absorbed ???60% of ingested Cd, which was in accordance with the partitioning of Cd to the bivalve's TAM compartment (i.e. Cd associated with organelles, 'enzymes' and MT); a similar relationship was found in previous studies with grass shrimp fed Cd-contaminated oligochaetes. Thus, TAM may be used as a tool to predict the trophic transfer of at least Cd. Subcellular fractionation revealed that ???34% of both the Cd and Zn accumulated by M. balthica was associated with TAM, while partitioning to TAM in P. amurensis was metal-dependent (???60% for TAM-Cd%, ???73% for TAM-Zn%). The greater TAM-Cd% of P. amurensis than M. balthica is due to preferential binding of Cd to MT and 'enzymes', while enhanced TAM-Zn% of P. amurensis results from a greater binding of Zn to organelles. TAM for most species-metal combinations was size-dependent, decreasing with increased clam size. Based on field data, it is estimated that of the 2 bivalves, P. amurensis poses the greater threat of Cd exposure to predators because of higher tissue concentrations and greater partitioning as TAM; exposure of Zn to predators would be similar between these species.

  3. 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

  4. Plio-Pleistocene extinctions and immigration credit reflected in the size-frequency distribution of Mediterranean marine bivalves

    Science.gov (United States)

    Nawrot, Rafal; Zuschin, Martin; Chattopadhyay, Devapriya

    2015-04-01

    Following the opening of the Suez Canal hundreds of Red Sea species have entered the Mediterranean Sea making it a global hot spot of marine bioinvasion. With the ongoing influx of the subtropical and tropical alien species and increasing sea surface temperatures, the Mediterranean biota is currently gaining a more tropical character and increasingly becoming a mixture of faunal stocks with different evolutionary histories. This susceptibility to invasion was suggested to reflect the presence of an empty ecological space left after decimation of incumbent warm-water fauna during Plio-Pleistocene climate fluctuations. As molluscs are among the most prolific immigrants, we test this hypothesis using data on taxonomic composition and body size of Pliocene Mediterranean bivalves derived from the literature sources and museum collections. The Pliocene inter-specific size-frequency distribution (SFD) is strikingly similar to the SFDs of the Recent Red Sea bivalve fauna, in spite of different biogeographic provenance and the absence of true reef ecosystems in the Pliocene of the Mediterranean region. In contrast, body-size patterns in both assemblages are significantly different from the present-day Mediterranean fauna characterized by smaller median and modal size. Our preliminary results suggest that the distinct shape of the modern Mediterranean SFD may reflect the selective nature of the late Piacenzian - Galesian (Late Pliocene - Early Pleistocene) extinctions pulses related to the onset of the Northern Hemisphere glaciations. These extinctions affected almost 40% of Pliocene species and were biased towards large-bodied taxa. They were not followed by re-immigration of warm-water species owing to the isolation from the tropical Atlantic biota by the cold upwelling along the NW coasts of Africa. The resulting invasion credit (sensu Jackson & Sax, 2010) is currently being paid by the Red Sea bivalves colonizing the Mediterranean Sea through the Suez Canal. Successful

  5. Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae.

    Science.gov (United States)

    Waldbusser, George G; Hales, Burke; Langdon, Chris J; Haley, Brian A; Schrader, Paul; Brunner, Elizabeth L; Gray, Matthew W; Miller, Cale A; Gimenez, Iria; Hutchinson, Greg

    2015-01-01

    Ocean acidification (OA) is altering the chemistry of the world's oceans at rates unparalleled in the past roughly 1 million years. Understanding the impacts of this rapid change in baseline carbonate chemistry on marine organisms needs a precise, mechanistic understanding of physiological responses to carbonate chemistry. Recent experimental work has shown shell development and growth in some bivalve larvae, have direct sensitivities to calcium carbonate saturation state that is not modulated through organismal acid-base chemistry. To understand different modes of action of OA on bivalve larvae, we experimentally tested how pH, PCO2, and saturation state independently affect shell growth and development, respiration rate, and initiation of feeding in Mytilus californianus embryos and larvae. We found, as documented in other bivalve larvae, that shell development and growth were affected by aragonite saturation state, and not by pH or PCO2. Respiration rate was elevated under very low pH (~7.4) with no change between pH of ~ 8.3 to ~7.8. Initiation of feeding appeared to be most sensitive to PCO2, and possibly minor response to pH under elevated PCO2. Although different components of physiology responded to different carbonate system variables, the inability to normally develop a shell due to lower saturation state precludes pH or PCO2 effects later in the life history. However, saturation state effects during early shell development will carry-over to later stages, where pH or PCO2 effects can compound OA effects on bivalve larvae. Our findings suggest OA may be a multi-stressor unto itself. Shell development and growth of the native mussel, M. californianus, was indistinguishable from the Mediterranean mussel, Mytilus galloprovincialis, collected from the southern U.S. Pacific coast, an area not subjected to seasonal upwelling. The concordance in responses suggests a fundamental OA bottleneck during development of the first shell material affected only by

  6. Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae.

    Directory of Open Access Journals (Sweden)

    George G Waldbusser

    Full Text Available Ocean acidification (OA is altering the chemistry of the world's oceans at rates unparalleled in the past roughly 1 million years. Understanding the impacts of this rapid change in baseline carbonate chemistry on marine organisms needs a precise, mechanistic understanding of physiological responses to carbonate chemistry. Recent experimental work has shown shell development and growth in some bivalve larvae, have direct sensitivities to calcium carbonate saturation state that is not modulated through organismal acid-base chemistry. To understand different modes of action of OA on bivalve larvae, we experimentally tested how pH, PCO2, and saturation state independently affect shell growth and development, respiration rate, and initiation of feeding in Mytilus californianus embryos and larvae. We found, as documented in other bivalve larvae, that shell development and growth were affected by aragonite saturation state, and not by pH or PCO2. Respiration rate was elevated under very low pH (~7.4 with no change between pH of ~ 8.3 to ~7.8. Initiation of feeding appeared to be most sensitive to PCO2, and possibly minor response to pH under elevated PCO2. Although different components of physiology responded to different carbonate system variables, the inability to normally develop a shell due to lower saturation state precludes pH or PCO2 effects later in the life history. However, saturation state effects during early shell development will carry-over to later stages, where pH or PCO2 effects can compound OA effects on bivalve larvae. Our findings suggest OA may be a multi-stressor unto itself. Shell development and growth of the native mussel, M. californianus, was indistinguishable from the Mediterranean mussel, Mytilus galloprovincialis, collected from the southern U.S. Pacific coast, an area not subjected to seasonal upwelling. The concordance in responses suggests a fundamental OA bottleneck during development of the first shell material

  7. Indian marine bivalves: Potential source of antiviral drugs

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Ansari, Z.A.; Ingole, B.S.; Bichurina, M.A.; Sovetova, M.; Boikov, Y.A.

    in large quantities by traditional methods and sold live in the market for human consumption. The economically important sp e cies of marine bivalves are green mussel ( Perna viridis ), e s tuarine oyster ( Crassostrea madrasensis ), giant oyster... in developing an effecti ve drug has been the unique characteristics of antigenic variation of virus resulting in the emergence of new variant virus strains 14 . There are a number of antiviral drugs introduced in the market such as tricyclic sy m- metric...

  8. Parasites of economically important bivalves from the southern coast of Bahia State, Brazil Parasitos de bivalves de interesse econômico no Litoral Sul do Estado da Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Gabriela Calvi Zeidan

    2012-12-01

    Full Text Available This study investigated the parasites of three commercially important bivalve species (Crassostrea rhizophorae, Mytella guyanensis and Lucina pectinata from the southern coast of Bahia, Brazil. A total of 540 specimens were collected in August 2009 and February 2010, at three localities. The bivalve specimens were measured on their longest axis, opened, and macroscopically examined for the presence of parasites or signs of disease. They were then fixed in Davidson' solution and subjected to routine histological processing, with paraffin embedding and H&E staining; next, the specimens were examined under a light microscope. No parasites were observed associated with L. pectinata. Rickettsia-like organisms (RLOs, Sphenophrya sp. (Ciliophora, Nematopsis sp. (Apicomplexa, Urastoma sp. (Turbellaria and Bucephalus sp. (Digenea were observed in both C. rhizophorae and M. guyanensis, as well as Ancistrocoma sp. (Ciliophora and Tylocephalum sp. (Cestoda in the former. A high prevalence of Nematopsis sp. was seen, but caused no apparent damage to the host. Bucephalus sp. caused the destruction of tissues, with castration, but showed low prevalence. The other parasites occurred in low prevalence and intensity, without causing significant damage.Neste estudo foram investigados os parasitos de três espécies de bivalves de interesse econômico (Crassostrea rhizophorae, Mytella guyanensis e Lucina pectinata da Bahia. Foram analisados 540 exemplares, obtidos em duas coletas (agosto-2009 e fevereiro-2010, em três localidades. Os bivalves foram medidos quanto ao seu maior eixo, abertos e examinados macroscopicamente quanto à presença de parasitos ou sinais de enfermidades. Depois disso, foram fixados em solução de Davidson e processados por rotina de histologia, com inclusão em parafina e coloração com H&E. O material foi examinado ao microscópio de luz. Nenhum parasito esteve associado a L. pectinata. Bactérias do tipo RLOs (organismos assemelhados a

  9. 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

  10. The Bivalve Production Chain in Santa Catarina, Brazil, and its Management and Operational Limitations

    OpenAIRE

    Gallon, Alessandra Vasconcelos; Universidade Federal do Ceará (UFC); Nascimento, Cristiano; Universidade Federal do Paraná - UFPR; Pfitscher, Elisete Dahmer; Universidade Federal de Santa Catarina

    2011-01-01

    Bivalve farming (mussels and oysters), a major component in the socio-economic development of the state of Santa Catarina, Brazil, combines the activities of public and private agencies in fish farming. Current analysis deals with the management and the operational limitations of the local bivalve production chain. Current exploratory research, undertaken by direct observations and the literature on the subject, employs data quality. Results show that the bivalve production chain, comprising ...

  11. Characterization of the secretomes of two vibrios pathogenic to mollusks.

    Directory of Open Access Journals (Sweden)

    Stéphanie Madec

    Full Text Available Vibrio tapetis causes the brown ring disease in the Japanese clam Ruditapes philippinarum while Vibrio aestuarianus is associated with massive oyster mortalities. As extracellular proteins are often associated with the virulence of pathogenic bacteria, we undertook a proteomic approach to characterize the secretomes of both vibrios. The extracellular proteins (ECPs of both species were fractionated by SEC-FPLC and in vitro assays were performed to measure the effects of each fraction on hemocyte cellular parameters (phagocytosis and adhesion. Fractions showing a significant effect were subjected to SDS-PAGE, and proteins were identified by nano LC-MS/MS. 45 proteins were identified for V. aestuarianus and 87 for V. tapetis. Most of them belonged to outer membrane or were periplasmic, including porins or adhesins that were already described as virulence factors in other bacterial species. Others were transporter components, flagella proteins, or proteins of unknown function (14 and 15 respectively. Interestingly, for V. aestuarianus, we noted the secretion of 3 extracellular enzymes including the Vam metalloprotease and two other enzymes (one putative lipase and one protease. For V. tapetis, we identified five extracellular enymes, i.e. two different endochitinases, one protease, one lipase and an adhesin. A comparison of both secretomes also showed that only the putative extracellular lipase was common to both secretomes, underscoring the difference in pathogenicity mechanisms between these two species. Overall, these results characterize for the first time the secretomes of these two marine pathogenic vibrios and constitute a useful working basis to further analyze the contribution of specific proteins in the virulence mechanisms of these species.

  12. Nyctemeral variations of magnesium intake in the calcitic layer of a Chilean mollusk shell (Concholepas concholepas, Gastropoda)

    OpenAIRE

    Lazareth, Claire E.; Guzman, Nury; Poitrasson, F.; Candaudap, F.; Ortlieb, Luc

    2007-01-01

    International audience; Mollusk shells are increasingly used as records of past environmental conditions, particularly for sea-surface temperature (SST) reconstructions. Many recent studies tackled SST (and/or sea-surface salinity) tracers through variations in the elementary (Mg and Sr) or stable isotope (δ18 O) composition within mollusk shells. But such attempts, which sometimes include calibration studies on modern specimens, are not always conclusive. We present here a series of Mg and S...

  13. Transgenerational exposure of North Atlantic bivalves to ocean acidification renders offspring more vulnerable to low pH and additional stressors.

    Science.gov (United States)

    Griffith, Andrew W; Gobler, Christopher J

    2017-09-12

    While early life-stage marine bivalves are vulnerable to ocean acidification, effects over successive generations are poorly characterized. The objective of this work was to assess the transgenerational effects of ocean acidification on two species of North Atlantic bivalve shellfish, Mercenaria mercenaria and Argopecten irradians. Adults of both species were subjected to high and low pCO 2 conditions during gametogenesis. Resultant larvae were exposed to low and ambient pH conditions in addition to multiple, additional stressors including thermal stress, food-limitation, and exposure to a harmful alga. There were no indications of transgenerational acclimation to ocean acidification during experiments. Offspring of elevated pCO 2 -treatment adults were significantly more vulnerable to acidification as well as the additional stressors. Our results suggest that clams and scallops are unlikely to acclimate to ocean acidification over short time scales and that as coastal oceans continue to acidify, negative effects on these populations may become compounded and more severe.

  14. Model studies of the effect of aerosol wastewater emissions on terrestrial mollusks Achatina fulica

    Directory of Open Access Journals (Sweden)

    Kamardin Nikolaj Nikolaevich

    2016-12-01

    Full Text Available The laboratory experiments were carried on using the juvenile mollusk Achatina fulica as a bioindicator of soil contamination and air pollution. It is shown that when experimental animals breathed and had dermal contact with the aerosols prepared from the wastewater and those prepared from two solutions of Ni in distilled water at two concentrations they weighed significantly less than controls . According to the results of AAS, heavy metals (HM, in particular Cd, Cu, Ni of sewage accumulated in the digestive gland of the shell. In model experiments mollusks were contained in the chamber periodically (2 hours of input and 2 hours of pause filled with aerosol containing Ni at concentrations of 30 and 50 mg / dm3 nickel for two weeks It resulted in accumulation of Ni in the digestive gland of mollusks with concentrations 6 to 10 times exceeding controls, respectively. At that the experimental animals gained weight reliably slower than the controls contained in aquatic aerosol without Ni. The subsequent one week exposure of shells in aerosol, prepared from the distilled water without Ni reduced the concentration of nickel in the tissue of the digestive gland. Thus, bioavailability of HM and nickel solutions prepared from untreated wastewaters in breathing aerosol and possibly by skin contact was demonstrated. The toxicant delivery seems to occur apart from food intake.

  15. Study on the bioaccumulation of Polonium-210 on bivalve indicator organisms of Tamilnadu and Pondicherry coast (East Coast of India)

    International Nuclear Information System (INIS)

    Syed Mohamed, H.E.; Sadiq Bukhari, A.; Meeramaideen, M.; Masilamani, V.; Shamsudin, Mohamed; Shahul Hameed, P.

    2012-01-01

    210 Po is a major contributor (90%) of the natural radiation dose from alpha-emitting radionuclides, received by most marine organisms. Among marine organisms, benthic fauna are superior to many other biological groups, since they could be monitored due to their sedentary habits and then must either adapt to environmental stress or perish. They also reflect the water conditions not only at the time of sampling but also for some past time as well. The affinity of 210 Po for protein enables it to pass through the food chain, and increased body burdens of 210 Po have been found where diets include protein-rich meat and seafood. The present study was launched to evaluate the rate of accumulation of 210 Po in the benthic bivalve molluscs such as Perna indica, P.viridis, Meretrix casta, Cardium coronatum, Gafrarium tumidum, Paphia textrix, Vellorita cyprinodea and Pinctada sp., of Tamilnadu and Pondicherry coast. Water samples, sediments and bivalves were collected from Gulf of Mannar (6 sampling stations), Palk Strait (8 sampling stations) of Tamilnadu and Pondicherry (6 sampling stations). 210 Po determination as made was as per standard protocols. The results showed that 210 Po concentration in coastal waters of Gulf of Mannar, Palk Strait and Pondicherry ranged 0.5 - 2.83 mBq/l (mean 1.33 mBq/I), 2.14 - 32.14 mBq/l (mean 15.3 mBq/l) and 1.36 - 2.0 mBq/1 (mean 1.59 mBq/1) respectively. The sediments maintained higher level of 210 Po (mean value of 3.62 Bq/kg in Gulf of Mannar, 107.9 Bq/kg in Palk Strait and 3.0 Bq/kg in Pondicherry) than water. The 210 Po rich sediment therefore serves as a vital link in the transfer of Polonium from water to the marine organisms. The concentration of 210 Po in eight species of bivalves collected from the study area, recorded a maximum level ranging from 65.2 to 2668.9 Bq/kg in soft tissues and from 1.19 to 15.3 Bq/kg in shells. The bioaccumulation ability in bivalve species with reference to 210 Po was observed to be highly variable

  16. Influence of temperature on fluoride toxicity and bioaccumulation in the nonindigenous freshwater mollusk Dreissena polymorpha Pallas, 1769.

    Science.gov (United States)

    Del Piero, Stefania; Masiero, Luciano; Casellato, Sandra

    2012-11-01

    Fluoride toxicity and bioaccumulation tests (short- and long-term) were performed on the nonindigenous freshwater mollusk Dreissena polymorpha at two different temperatures: 17 ± 0.5°C and 22 ± 0.5°C. Concentrations that did not result in toxicity in short-term experiments (96 h) induced effects over a longer period (17 weeks), especially at the warmest temperature, highlighting the role of this parameter. Fluoride bioaccumulation increased linearly with increasing concentration and temperature, reaching 4,202 µg F(-)/g dry weight in soft tissues only after 48 h of exposure at 22°C at a concentration of 640 mg F(-)/L. Comparing tolerance to fluoride and bioaccumulation values of this species with those of other freshwater invertebrates, D. polymorpha was much more resistant and revealed its capacity to accumulate a great quantity of this xenobiotic substance. The results of the present study demonstrated that fluoride accumulation in the soft tissue of this animal was much higher (up to 1,409.6 µg F(-)/g dry wt) than that in its shell (up to 706.4 µg F(-)/g dry wt). If we consider this datum and the fact that D. polymorpha is widespread in many aquatic ecosystems around the world, representing a food source for many birds and other vertebrates, we must acknowledge the possibility that it can represent a serious danger in view of fluoride biomagnification in the aquatic environment. Copyright © 2012 SETAC.

  17. 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

  18. A novel filtering mutualism between a sponge host and its endosymbiotic bivalves.

    Science.gov (United States)

    Tsubaki, Remi; Kato, Makoto

    2014-01-01

    Sponges, porous filter-feeding organisms consisting of vast canal systems, provide unique substrates for diverse symbiotic organisms. The Spongia (Spongia) sp. massive sponge is obligately inhabited by the host-specific endosymbiotic bivalve Vulsella vulsella, which benefits from this symbiosis by receiving protection from predators. However, whether the host sponge gains any benefit from this association is unclear. Considering that the bivalves exhale filtered water into the sponge body rather than the ambient environment, the sponge is hypothesized to utilize water exhaled by the bivalves to circulate water around its body more efficiently. We tested this hypothesis by observing the sponge aquiferous structure and comparing the pumping rates of sponges and bivalves. Observations of water currents and the sponge aquiferous structure revealed that the sponge had a unique canal system enabling it to inhale water exhaled from bivalves, indicating that the host sponge adapted morphologically to receive water from the bivalves. In addition, the volume of water circulating in the sponge body was dramatically increased by the water exhaled from bivalves. Therefore, this sponge-bivalve association can be regarded as a novel mutualism in which two filter-feeding symbionts promote mutual filtering rates. This symbiotic association should be called a "filtering mutualism".

  19. Development of human impact on suspension-feeding bivalves in coastal soft-bottom ecosystems

    NARCIS (Netherlands)

    Wolff, Wim J.; Dame, RF; Olenin, S

    2005-01-01

    Suspension-feeding bivalves often may occur in large concentrations ('beds') on tidal flats. This makes them attractive for human consumers and the archaeological record shows collection of bivalves by coastal populations already tens of thousands of years ago. In modem time human interference with

  20. Effect of dietary polyunsaturated fatty acids on reproductive output and larval growth of bivalves

    NARCIS (Netherlands)

    Hendriks, I.E.; Van Duren, L.A.; Herman, P.M.J.

    2003-01-01

    The pre-spawning condition of adult bivalves is influenced by quantity and quality of available food. For bivalves, the essential polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) 20:5(n-3) and docosahexaenoic acid (DHA) 22:6(n-3) are presumed to determine the nutritional value of

  1. Pharmaceutically active compounds and endocrine disrupting chemicals in water, sediments and mollusks in mangrove ecosystems from Singapore.

    Science.gov (United States)

    Bayen, Stéphane; Estrada, Elvagris Segovia; Juhel, Guillaume; Kit, Lee Wei; Kelly, Barry C

    2016-08-30

    This study investigated the occurrence of bisphenol A (BPA), atrazine and selected pharmaceutically active compounds (PhACs) in mangrove habitats in Singapore in 2012-2013, using multiple tools (sediment sampling, POCIS and filter feeder molluscs). Using POCIS, the same suite of contaminants (atrazine, BPA and eleven PhACs) was detected in mangrove waters in 28-days deployments in both 2012 and 2013. POCIS concentrations ranged from pg/L to μg/L. Caffeine, BPA, carbamazepine, E1, triclosan, sulfamerazine, sulfamethazine, and lincomycin were also detected in mangrove sediments from the low pg/g dw (e.g. carbamazepine) to ng/g dw (e.g. BPA). The detection of caffeine, carbamazepine, BPA, sulfamethoxazole or lincomycin in bivalve tissues also showed that these chemicals are bioavailable in the mangrove habitat. Since there are some indications that some pharmaceutically active substances may be biologically active in the low ppb range in marine species, further assessment should be completed based on ecotoxicological data specific to mangrove species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Marine Bivalve Cellular Responses to Beta Blocker Exposures ...

    Science.gov (United States)

    β blockers are prescription drugs used for medical treatment of hypertension and arrhythmias. They prevent binding of agonists such as catecholamines to β adrenoceptors. In the absence of agonist induced activation of the receptor, adenylate cyclase is not activated which in turn limits cAMP production and protein kinase A activation, preventing increases in blood pressure and arrhythmias. After being taken therapeutically, commonly prescribed β blockers may make their way to coastal habitats via discharge from waste water treatment plants (WWTP) posing a potential risk to aquatic organisms. The aim of our research is to evaluate cellular responses of three commercially important marine bivalves - Eastern oysters, blue mussels and hard clams - upon exposure to two β blocker drugs, propranolol and metoprolol, and to find molecular initiating events (MIEs) indicative of the exposure. Bivalves were obtained from Narragansett Bay (Rhode Island, USA) and acclimated in the laboratory. Following acclimation, gills and hepatopancreas (HP) tissues were harvested and separately exposed to 0, 1, 10, 100 and 1000 ng/l of each drug. Tissues were bathed in 30 parts per thousand (ppt) filtered seawater, antibiotic mix, Leibovitz nutrient media, and the test drug. Exposures were conducted for 24 hours and samples were saved for cellular biomarker assays. A lysosomal destabilization assay, which is a marker of membrane damage, was also performed at the end of each exposure.

  3. The quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897 – another Ponto-Caspian dreissenid bivalve in the southern Baltic catchment: the first record from the Szczecin Lagoon

    Directory of Open Access Journals (Sweden)

    Adam Woźniczka

    2016-04-01

    Full Text Available In 2014, a non-indigenous dreissenid bivalve, the quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897 was for the first time recorded in the Szczecin Lagoon. This was also the first record of the species in the Baltic Sea catchment. The quagga mussel was found to accompany the zebra mussel (Dreissena polymorpha, a non-indigenous bivalve already firmly established in the Lagoon. As indicated by the new immigrant's estimated abundance (4000.0 ± 355.44 ind. m−2 and the zebra mussel to quagga mussel abundance ratio (about 60:40, the immigration of D. rostriformis bugensis to the Lagoon can be regarded as successful. The quagga mussel has already formed a strong and reproducing population which co-occurs with that of the zebra mussel in the area.

  4. Preliminary Results on the Evaluation of the Occurrence of Tetrodotoxin Associated to Marine Vibrio spp. in Bivalves from the Galician Rias (Northwest of Spain

    Directory of Open Access Journals (Sweden)

    Jose Manuel Leão

    2018-03-01

    Full Text Available Tetrodotoxins (TTX are a potent group of natural neurotoxins putatively produced by symbiotic microorganisms and affecting the aquatic environment. These neurotoxins have been recently found in some species of bivalves and gastropods along the European Coasts (Greece, UK, and The Netherlands linked to the presence of high concentrations of Vibrio, in particular Vibrio parahaemolyticus. This study is focused on the evaluation of the presence of Vibrio species and TTX in bivalves (mussels, oysters, cockles, clams, scallops, and razor clams from Galician Rias (northwest of Spain. The detection and isolation of the major Vibrio spp. and other enterobacterial populations have been carried out with the aim of screening for the presence of the pathways genes, poliketide synthase (PKS and non-ribosomal peptide synthetase (NRPS possibly involved in the biosynthesis of these toxins. Samples containing Vibrio spp. were analyzed by biochemical (API20E-galery and genetic tests (PCR-RT. These samples were then screened for TTX toxicity by a neuroblastoma cell-based assay (N2a and the presence of TTX was further confirmed by LC-MS/MS. TTX was detected in two infaunal samples. This is the first confirmation of the presence of TTX in bivalve molluscs from the Galician Rias.

  5. 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

  6. Los moluscos y la contaminación: Una revisión Mollusks and pollution: A review

    Directory of Open Access Journals (Sweden)

    Erick Raúl Baqueiro-Cárdenas

    2007-10-01

    Full Text Available Los moluscos son un grupo megadiverso que en cuanto a número de especies sólo lo sobrepasan los insectos y los nemátodos; no así en cuanto a la diversidad de hábitos de vida y hábitats que ocupan. Las especies de moluscos se encuentran en los desiertos y en las zonas polares; en los trópicos y en las grandes profundidades oceánicas. Sin embargo, es en las lagunas litorales tropicales donde alcanzan su máxima diversidad y función; los hay desde consumidores primarios en las redes tróficas, tanto de herbívoros como de detritívoros, hasta depredadores de segundo nivel y parásitos especializados. Existen especies especializadas y especies oportunistas, lo que se manifiesta en diferentes respuestas a las modificaciones del hábitat y la contaminación. En esta contribución se analizan las respuestas que individuos o poblaciones de moluscos tienen al impacto de la contaminación, así como sus mecanismos etológicos y fisiológicos de adaptación o sobrevivencia. Tomando en consideración lo anterior, se plantea su aplicación como indicadores de contaminación, ya sea por la desaparición de especies estenobiónticas, el predominio de las euribiónticas o por su capacidad de acumular contaminantes cuando sus concentraciones no alcanzan dosis que impacten las poblaciones, bien en procesos de bioacumulación a lo largo del ciclo de vida del organismo o por biomagnificación a través de las cadenas tróficas o de los cambios fisiológicos producidos por la contaminación.Mollusks are a mega-diverse group, surpassed only by insects and nematodes in number of species, but not in diversity of life strategies and occupied habitats; they can be found from deserts to polar zones and from the highest mountain to the deepest ocean trench. But it is at tropical coastal lagoons where they find their maximum diversity and function; there are first order consumers in both herbivore and detritus food chains, to second order carnivores and specialized

  7. GSD Update: What are invasive species? ... And do we really need to worry about them?

    Science.gov (United States)

    Catherine Dold

    2011-01-01

    Invasive species are the focus of the September 2011 issue of GSDUpdate: What Are Invasive Species? And Do We Really Need to Worry About Them? An invasive species is any species - non-native or native to a region - that could cause economic or ecological harm to an area. Invasives can be weeds, shrubs and trees, insects, mollusks, vertebrates and even microorganisms...

  8. [Risk-benefit of some mollusks and processed fishes in the renal patient's diet].

    Science.gov (United States)

    Castro-González, M I; Miranda-Becerra, D; Pérez-Gil, R F

    2010-03-01

    The renal diet must include limited amounts of high quality protein, phosphorus P and potassium K. n-3 polyunsaturated fatty acids (n-3PUFA EPA and DHA), present in fishes and mollusks, render beneficial properties against progression of renal damage. The aim of this study was to evaluate protein PR, phosphorus P, potassium K, calcium Ca and n-3PUFA in processed fishes and mollusks as an alimentary option for renal patients. Canned tuna (water AA and oil AC), sardine in tomate sauce ST and chipotle SC and smoked salmon SA, fresh jumbo flying squid CA, common octopus PU and oyster OS were evaluated. Significant difference was detected (p <.0.05) for K between different types of fish. SA contained 38g/100g PR, 307 mg/100g of P, 371 mg/ 100g K and 106 mg/100g n-3PUFA. Sardines contained (279-304 mg/100g of P and 283-322 mg/100g K and tunas 142-160 mg/100g P and 141-154 mg/100g K. Tunas and sardines had elevated concentration of n-3PUFA (4114 and 4790 mg/ 100g respectively), P:n-3PUFA and K:n-3PUFA ratio was low in tunas (0.03) and sardines (0.06). AA and AC contained (10.1 and 11.1 mgP/gPR), while ST and SC provided 26.4-19.1 mg/P/gPR. n-3PUFA/gPR were similar for tunas and sardines (302-424mg/gPR). Mollusks: CA presented the highest values of P and PR (2.4 mg/100g and 18.4g/100g). n-3PUFA ranged from 4.3 to 79 mg/100g in PU and OS respectively. Among processed fishes, only canned tunas are recommended for the diet of renal patients, in an individualized basis. The risk-benefit ratio of sardines in the renal diet should be evaluated, due to their high content of P and n-3PUFA. Salmon and mollusks are not recommended for the renal diet.

  9. Smaller calcite lattice deformation caused by occluded organic material in coccoliths than in mollusk shell

    DEFF Research Database (Denmark)

    Frølich, Simon; Sørensen, Henning Osholm; Hakim, Sepideh Sadat

    2015-01-01

    The growth and nucleation of biominerals are directed and affected by associated biological molecules. In this paper, we investigate the influence of occluded biomolecules on biogenic calcite from the coccolithophorid Pleurochrysis carterae and from chalk, a rock composed predominantly of fossil....... Two heating cycles allow us to differentiate the effects of thermal agitation and organic molecules. Single peak analysis and Rietveld refinement were combined to show significant differences resulting from the occluded biomolecules on the mineral phase in biogenic calcite in the mollusk shell...

  10. Study of the elemental content in mollusk from Uruguayan's coast by X-ray fluorescence

    International Nuclear Information System (INIS)

    Bernasconi, G.; Odino, R.; Souto, B.; Mendez, Silvia

    1992-01-01

    The main objective of the study is to establish a starting point on the content of trace elements, either with a toxic and/or nutritional interest, in Uruguayan coastal mollusks. The River Plate is located between Argentina and Uruguay and has an estuarine nature. It is thus a zone with distinctive features among the South American Atlantic coasts. The analysis techniqe employed is X-ray fluroescence, which is non-destructive and multi-elemental. A simple way of sample preparation is proposed, which does not use reagents that may introduce foreign elements, and is therefore low cost. tabs

  11. Molecular phylogeny of the bivalve superfamily Galeommatoidea (Heterodonta, Veneroida) reveals dynamic evolution of symbiotic lifestyle and interphylum host switching

    Science.gov (United States)

    2012-01-01

    Background Galeommatoidea is a superfamily of bivalves that exhibits remarkably diverse lifestyles. Many members of this group live attached to the body surface or inside the burrows of other marine invertebrates, including crustaceans, holothurians, echinoids, cnidarians, sipunculans and echiurans. These symbiotic species exhibit high host specificity, commensal interactions with hosts, and extreme morphological and behavioral adaptations to symbiotic life. Host specialization to various animal groups has likely played an important role in the evolution and diversification of this bivalve group. However, the evolutionary pathway that led to their ecological diversity is not well understood, in part because of their reduced and/or highly modified morphologies that have confounded traditional taxonomy. This study elucidates the taxonomy of the Galeommatoidea and their evolutionary history of symbiotic lifestyle based on a molecular phylogenic analysis of 33 galeommatoidean and five putative galeommatoidean species belonging to 27 genera and three families using two nuclear ribosomal genes (18S and 28S ribosomal DNA) and a nuclear (histone H3) and mitochondrial (cytochrome oxidase subunit I) protein-coding genes. Results Molecular phylogeny recovered six well-supported major clades within Galeommatoidea. Symbiotic species were found in all major clades, whereas free-living species were grouped into two major clades. Species symbiotic with crustaceans, holothurians, sipunculans, and echiurans were each found in multiple major clades, suggesting that host specialization to these animal groups occurred repeatedly in Galeommatoidea. Conclusions Our results suggest that the evolutionary history of host association in Galeommatoidea has been remarkably dynamic, involving frequent host switches between different animal phyla. Such an unusual pattern of dynamic host switching is considered to have resulted from their commensalistic lifestyle, in which they maintain filter

  12. Molecular phylogeny of the bivalve superfamily Galeommatoidea (Heterodonta, Veneroida reveals dynamic evolution of symbiotic lifestyle and interphylum host switching

    Directory of Open Access Journals (Sweden)

    Goto Ryutaro

    2012-09-01

    Full Text Available Abstract Background Galeommatoidea is a superfamily of bivalves that exhibits remarkably diverse lifestyles. Many members of this group live attached to the body surface or inside the burrows of other marine invertebrates, including crustaceans, holothurians, echinoids, cnidarians, sipunculans and echiurans. These symbiotic species exhibit high host specificity, commensal interactions with hosts, and extreme morphological and behavioral adaptations to symbiotic life. Host specialization to various animal groups has likely played an important role in the evolution and diversification of this bivalve group. However, the evolutionary pathway that led to their ecological diversity is not well understood, in part because of their reduced and/or highly modified morphologies that have confounded traditional taxonomy. This study elucidates the taxonomy of the Galeommatoidea and their evolutionary history of symbiotic lifestyle based on a molecular phylogenic analysis of 33 galeommatoidean and five putative galeommatoidean species belonging to 27 genera and three families using two nuclear ribosomal genes (18S and 28S ribosomal DNA and a nuclear (histone H3 and mitochondrial (cytochrome oxidase subunit I protein-coding genes. Results Molecular phylogeny recovered six well-supported major clades within Galeommatoidea. Symbiotic species were found in all major clades, whereas free-living species were grouped into two major clades. Species symbiotic with crustaceans, holothurians, sipunculans, and echiurans were each found in multiple major clades, suggesting that host specialization to these animal groups occurred repeatedly in Galeommatoidea. Conclusions Our results suggest that the evolutionary history of host association in Galeommatoidea has been remarkably dynamic, involving frequent host switches between different animal phyla. Such an unusual pattern of dynamic host switching is considered to have resulted from their commensalistic lifestyle, in

  13. Uptake and loss of 134Cs and 60Co by the Baltic bivalve Macoma Baltica under laboratory conditions

    International Nuclear Information System (INIS)

    Evans, S.

    1982-01-01

    In order to predict the radiological impact on man via harvestable sea food products, it is essential to make a critical evaluation of the transfer routes and the rates on which radionuclides are transferred through the aquatic food chains. In the Baltic, the bivalve Macoma Baltica comprises a main food item for fish species of commercial interest, such as flounder. The accumulation and release of Cs-134 and Co-60 by Macoma was experimentally investigated. The nuclides were added to the water and the activity content of the bivalves was determined at regular intervals. The uptake was quite rapid, 40 per cent (Cs) and 55 per cent (Co) respectively of the final steady state was obtained after 24 hours. The subsequent release was rapid as well, 50 per cent (Cs) and 40 per cent (Co) respectively of the accumulated activity was lost within 6 days. The experiments demonstrated that the major intake route following short-term releases of activity will be from the water column. The close connection between activity in water and organism can thus be used for predictive purposes without the complication of radionuclide uptake from contaminated sediments. (Author)

  14. Carbon and nitrogen elemental and isotopic ratios of filter-feeding bivalves along the French coasts: An assessment of specific, geographic, seasonal and multi-decadal variations.

    Science.gov (United States)

    Briant, Nicolas; Savoye, Nicolas; Chouvelon, Tiphaine; David, Valérie; Rodriguez, Samuel; Charlier, Karine; Sonke, Jeroen E; Chiffoleau, Jean François; Brach-Papa, Christophe; Knoery, Joël

    2018-02-01

    Primary consumers play a key role in coastal ecosystems by transferring organic matter from primary producers to predators. Among them, suspension-feeders, like bivalve molluscs are widely used in trophic web studies. The main goal of this study was to investigate variations of C and N elemental and isotopic ratios in common bivalves (M. edulis, M. galloprovincialis, and C. gigas) at large spatial (i.e. among three coastal regions) and different temporal (i.e. from seasonal to multi-decadal) scales in France, in order to identify potential general or specific patterns and speculate on their drivers. The observed spatial variability was related to the trophic status of the coastal regions (oligotrophic Mediterranean Sea versus meso- to eutrophic English Channel and Atlantic ocean), but not to ecosystem typology (estuaries, versus lagoons versus bays versus littoral systems). Furthermore, it highlighted local specificities in terms of the origin of the POM assimilated by bivalves (e.g., mainly continental POM vs. marine phytoplankton vs. microphytobenthic algae). Likewise, seasonal variability was related both to the reproduction cycle for C/N ratios of Mytilus spp. and to changes in trophic resources for δ 13 C of species located close to river mouth. Multi-decadal evolution exhibited shifts and trends for part of the 30-year series with decreases in δ 13 C and δ 15 N. Specifically, shifts appeared in the early 2000's, likely linking bivalve isotopic ratios to a cascade of processes affected by local drivers. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. High pressure processing of bivalve shellfish and HPP's potential use as a virus intervention

    Science.gov (United States)

    Bivalve shellfish readily bioconcentrate pathogenic microbes and substance, such as algal and dinoflagulate toxins, fecal viruses and bacteria, and naturally present vibrio bacteria. High pressure processing (HPP) is currently used as an intervention for Vibrio vulnificus bacteria within molluscan ...

  16. Revision of the Late Permian Non-Marine Bivalve Genus Verneuilunio Starobogatov, 1987

    Directory of Open Access Journals (Sweden)

    M.N. Urazaeva

    2015-03-01

    Full Text Available The genus Verneuilunio (type species Naiadites verneuili has been singled out from the genus Palaeanodonta Amalitzky based on differences in the structure of hinge margin established using the literature data. Both genera have been included in the family Palaeanodontidae, which used to be considered by the discoverer of this genus as a subjective synonym for the family Palaeomutelidae. The revision of W. Amalitskii’s collection has demonstrated that the original diagnosis of the genus con-tains a number of inaccuracies. This creates difficulties for identification of the genus Verneuilunio and complicates its placement within higher taxa. The paper presents a revised diagnosis of the genus Verneuilunio. The detailed description of its type species is provided. The genus Verneuilunio has been assigned to the family Naiaditidae based on the duplivincular and slightly amphidetic ligament. According to this feature, the genus under study is significantly different from other unio-like Late Permian non-marine bivalve genera (Palaeomutela, Palaeanodonta, Oligodontella, and Opokiella, often occurring in the same strata. The genus Verneuilunio mostly resembles some Late Carboniferous “atypical” unio-like species of the genus Anthraconaia Trueman et Weir. Statistical processing of the biometric parameters of Verneuilunio verneuili and the species A. pruvosti, mostly resembling it, has revealed statistically significant differences in elongation of the posterior end of the shell. To date, the geographic range of the genus Verneuilunio is restricted to the central part of the East European Platform, whereas its stratigraphic range is in the lower sublayer of the Severodvinsk layer.

  17. The isotopic biosignatures of photo- vs. thiotrophic bivalves: are they preserved in fossil shells?

    Science.gov (United States)

    Dreier, A; Loh, W; Blumenberg, M; Thiel, V; Hause-Reitner, D; Hoppert, M

    2014-09-01

    Symbiont-bearing and non-symbiotic marine bivalves were used as model organisms to establish biosignatures for the detection of distinctive symbioses in ancient bivalves. For this purpose, the isotopic composition of lipids (δ13C) and bulk organic shell matrix (δ13C, δ34S, δ15N) from shells of several thiotrophic, phototrophic, or non-symbiotic bivalves were compared (phototrophic: Fragum fragum, Fragum unedo, Tridacna maxima; thiotrophic: Codakia tigerina, Fimbria fimbriata, Anodontia sp.; non-symbiotic: Tapes dorsatus, Vasticardium vertebratum, Scutarcopagia sp.). ∆13C values of bulk organic shell matrices, most likely representing mainly original shell protein/chitin biomass, were depleted in thio- and phototrophic bivalves compared to non-symbiotic bivalves. As the bulk organic shell matrix also showed a major depletion of δ15N (down to -2.2 ‰) for thiotrophic bivalves, combined δ13C and δ15N values are useful to differentiate between thio-, phototrophic, and non-symbiotic lifestyles. However, the use of these isotopic signatures for the study of ancient bivalves is limited by the preservation of the bulk organic shell matrix in fossils. Substantial alteration was clearly shown by detailed microscopic analyses of fossil (late Pleistocene) T. maxima and Trachycardium lacunosum shell, demonstrating a severe loss of quantity and quality of bulk organic shell matrix with time. Likewise, the composition and δ13C-values of lipids from empty shells indicated that a large part of these compounds derived from prokaryotic decomposers. The use of lipids from ancient shells for the reconstruction of the bivalve's life style therefore appears to be restricted. © 2014 John Wiley & Sons Ltd.

  18. Calibration of hydroclimate proxies in freshwater bivalve shells from Central and West Africa

    Science.gov (United States)

    Kelemen, Zita; Gillikin, David P.; Graniero, Lauren E.; Havel, Holly; Darchambeau, François; Borges, Alberto V.; Yambélé, Athanase; Bassirou, Alhou; Bouillon, Steven

    2017-07-01

    Freshwater bivalve shell oxygen and carbon stable isotope ratios (δ18O, δ13C) may act as recorders of hydroclimate (e.g., precipitation-evaporation balance, discharge) and aquatic biogeochemistry. We investigate the potential of these hydroclimate proxies measured along the growth axis of shells collected from the Oubangui River (Bangui, Central African Republic) and the Niger River (Niamey, Niger). Biweekly water samples and in situ measurements collected over several years, along with daily discharge data from both sites allowed a direct comparison with proxies recorded in the shells. Data from a total of 14 unionid shells, including three species (Chambardia wissmanni, Aspatharia dahomeyensis, and Aspatharia chaiziana), confirmed that shells precipitate carbonate in oxygen isotope equilibrium with ambient water. Because water temperature variations were small, shell δ18O values (δ18Oshell) also accurately record the seasonality and the range observed in water δ18O (δ18Ow) values when calculated using an average temperature. Calculated δ18Ow values were in good agreement over the entire record of measured δ18Ow values, thus δ18Oshell records can be reliably used to reconstruct past δ18Ow values. Discharge and δ18Ow values from both rivers fit a logarithmic relationship, which was used to attempt reconstruction of past hydrological conditions, after calculating δ18Ow values from δ18Oshell values. A comparison with measured discharge data suggests that for the two rivers considered, δ18Oshell data are good proxies for recording discharge conditions during low(er) discharge levels, but that high discharge values cannot be accurately reconstructed due to the large scatter in the discharge-δ18Ow relationship. Moreover, periods of bivalve shell growth cessation due to high turbidity or air exposure should be taken into account. While δ13C values of dissolved inorganic carbon in both rivers showed clear seasonality and correlated well with discharge

  19. Facultative parasitism by the bivalve Kurtiella pedroana in the sand crab Emerita analoga

    Science.gov (United States)

    Bhaduri, Ritin; Valentich-Scott, Paul; Hilgers, Mark; Singh, Rajvir; Hickman, Mikaila; Lafferty, Kevin D.

    2017-01-01

    It is rare that an organism capable of independent or commensalistic existence can also become endoparasitic on a host. In this study, we documented a potential step toward parasitism in the commensal clam Kurtiella pedroana (Bivalvia: Galeommatoidea). Galeommatoideans are known commensals of various invertebrates, including crustaceans. Emerita analoga (Decapoda: Hippidae) is an abundant intertidal decapod inhabiting sandy beaches of the Pacific coast of North and South America. Crabs collected from Monterey Bay, California, were measured and examined externally and internally for associated molluscs. Out of the 520 crabs, 37 large female individuals harbored 49 bivalves (prevalence of 7.11% and mean intensity of 1.3). Forty-one ectocommensal clams were either inside the crab's branchial chambers or on their lateroventral surfaces, and were attached by byssal threads. Our key finding was eight clams that lacked byssal threads and were living in the hemocoel. These internal clams were significantly smaller than the ectocommensals. Because these internal clams lacked access to their normal food, we hypothesize they might have fed on their host's hemolymph as would a parasite. This clam species likely can't reproduce inside its host, implying that endoparasitism is a dead-end state for K. pedroana. Facultative parasitism in a free-living or an ectocommensal is uncommon and suggests a pathway to parasitism.

  20. Physiological status and intersex in the endobenthic bivalve Scrobicularia plana from thirteen estuaries in northwest France

    International Nuclear Information System (INIS)

    Fossi Tankoua, O.; Amiard-Triquet, C.; Denis, F.; Minier, C.; Mouneyrac, C.; Berthet, B.

    2012-01-01

    The bivalve Scrobicularia plana, an important species for the structure and functioning of estuarine and coastal mudflats, was studied in thirteen sites from NW France differing by their degree of contamination to document the presence of reproduction impairments (intersex, sex ratio, gonadosomatic indices) in relation to the condition revealed by using hepatosomatic and condition indices. In agreement with recent studies in other European estuaries, intersex was revealed in all the studied estuaries, including sites the chemical and ecological status of which is considered “good” according to the criteria of the European Water Framework Directive. The presence of endocrine disrupting chemicals (EDCs) could result in such disturbances. Our results re-inforce the concern linked to the subtle effects of EDCs, which are active at very low doses, often in the absence of any major sign of toxicity. However at this stage, no clear link may be established between intersex and population effects. - Highlights: ► Clams were collected from 13 estuaries differing by their degree of contamination. ► Gonadosomatic, hepatosomatic and condition indices were determined. ► Reproduction impairments (intersex, biased sex ratio, asynchronism) were shown. ► Intersex shown even at sites with good ecological status (Water Framework Directive). ► No clear links between intersex and populational effects. - Intersex in clams from estuaries, the chemical/ecological status of which was considered as good under the EC Water Framework Directive.

  1. Effect of the alien invasive bivalve Corbicula fluminea on the nutrient dynamics under climate change scenarios

    Science.gov (United States)

    Coelho, J. P.; Lillebø, A. I.; Crespo, D.; Leston, S.; Dolbeth, M.

    2018-05-01

    The main aim of this study was to evaluate the impact of the alien invasive bivalve Corbicula fluminea (Müller, 1774) in the nutrient dynamics of temperate estuarine systems (oligohaline areas) under climate change scenarios. The scenarios simulated shifts in climatic conditions, following salinity (0 or 5) and temperature (24 or 30 °C) changes, usual during drought and heat wave events. The effect of the individual size/age (different size classes with fixed biomass) and density (various densities of <1 cm clams) on the bioturbation-associated nutrient dynamics were also evaluated under an 18-day laboratory experimental setup. Results highlight the significant effect of C. fluminea on the ecosystem nutrient dynamics, enhancing the efflux of both phosphate and dissolved inorganic nitrogen (DIN) from the sediments to the water column. Both drought and heat wave events will have an impact on the DIN dynamics within C. fluminea colonized systems, favouring a higher NH4-N efflux. The population structure of C. fluminea will have a decisive role on the impact of the species, with stronger nutrient effluxes associated with a predominantly juvenile population structure.

  2. [Isolation of the cercaria Diplostomum phoxini (Faust, 1918) Arvy et Buttner, 1954 (Diplostomatidae) from fresh water mollusks of the Crimea].

    Science.gov (United States)

    Sten'ko, R P

    1976-01-01

    Data on the biology and morphology of cercariae of Diplostomum phoxini (Faust, 1918) Arvy et Buttner, 1954 are given. The cercariae were found in Radix auricularia from the middle part of the Burulcha river (Ukranian SSR, Crimea). In November, 1974 the invasion extensity of mollusks was 16.3%. No cercariae were found in spring and summer samples.

  3. Genetic connectivity between north and south Mid-Atlantic Ridge chemosynthetic bivalves and their symbionts.

    Directory of Open Access Journals (Sweden)

    Karina van der Heijden

    Full Text Available Transform faults are geological structures that interrupt the continuity of mid-ocean ridges and can act as dispersal barriers for hydrothermal vent organisms. In the equatorial Atlantic Ocean, it has been hypothesized that long transform faults impede gene flow between the northern and the southern Mid-Atlantic Ridge (MAR and disconnect a northern from a southern biogeographic province. To test if there is a barrier effect in the equatorial Atlantic, we examined phylogenetic relationships of chemosynthetic bivalves and their bacterial symbionts from the recently discovered southern MAR hydrothermal vents at 5°S and 9°S. We examined Bathymodiolus spp. mussels and Abyssogena southwardae clams using the mitochondrial cytochrome c oxidase subunit I (COI gene as a phylogenetic marker for the hosts and the bacterial 16S rRNA gene as a marker for the symbionts. Bathymodiolus spp. from the two southern sites were genetically divergent from the northern MAR species B. azoricus and B. puteoserpentis but all four host lineages form a monophyletic group indicating that they radiated after divergence from their northern Atlantic sister group, the B. boomerang species complex. This suggests dispersal of Bathymodiolus species from north to south across the equatorial belt. 16S rRNA genealogies of chemoautotrophic and methanotrophic symbionts of Bathymodiolus spp. were inconsistent and did not match the host COI genealogy indicating disconnected biogeography patterns. The vesicomyid clam Abyssogena southwardae from 5°S shared an identical COI haplotype with A. southwardae from the Logatchev vent field on the northern MAR and their symbionts shared identical 16S phylotypes, suggesting gene flow across the Equator. Our results indicate genetic connectivity between the northern and southern MAR and suggest that a strict dispersal barrier does not exist.

  4. An integrated ecosystem approach for assessing the potential role of cultivated bivalve shells as part of the carbon trading system

    DEFF Research Database (Denmark)

    Filgueira, Ramón; Byron, C.J.; Comeau, L.A.

    2015-01-01

    , is needed to provide a rigorous assessment of the role of bivalve mariculture in the CO2 cycle. On the other hand, the discussion about the inclusion of shells of cultured bivalves into the carbon trading system should be framed in the context of ecosystem goods and services. Humans culture bivalves......The role of bivalve mariculture in the CO2 cycle has been commonly evaluated as the balance between respiration, shell calcium carbonate sequestration and CO2 release during biogenic calcification. However, this approach neglects the ecosystem implications of cultivating bivalves at high densities...... with the aim of producing food, not sequestering CO2 in their shells, therefore the main ecosystem good provided by bivalve aquaculture is meat production, and shells should be considered as by-products of this human activity. This reasoning is key to split the CO2 released due to respiration between meat...

  5. From bacteria to mollusks: the principles underlying the biomineralization of iron oxide materials.

    Science.gov (United States)

    Faivre, Damien; Godec, Tina Ukmar

    2015-04-13

    Various organisms possess a genetic program that enables the controlled formation of a mineral, a process termed biomineralization. The variety of biological material architectures is mind-boggling and arises from the ability of organisms to exert control over crystal nucleation and growth. The structure and composition of biominerals equip biomineralizing organisms with properties and functionalities that abiotically formed materials, made of the same mineral, usually lack. Therefore, elucidating the mechanisms underlying biomineralization and morphogenesis is of interdisciplinary interest to extract design principles that will enable the biomimetic formation of functional materials with similar capabilities. Herein, we summarize what is known about iron oxides formed by bacteria and mollusks for their magnetic and mechanical properties. We describe the chemical and biological machineries that are involved in controlling mineral precipitation and organization and show how these organisms are able to form highly complex structures under physiological conditions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Applicability of a bioelectronic cardiac monitoring system for the detection of biological effects of pollution in bioindicator species in the Gulf of Finland

    Science.gov (United States)

    Kholodkevich, Sergey V.; Kuznetsova, Tatiana V.; Sharov, Andrey N.; Kurakin, Anton S.; Lips, Urmas; Kolesova, Natalia; Lehtonen, Kari K.

    2017-07-01

    Field testing of an innovative technology based on a bioelectronic cardiac monitoring system was carried out in the Gulf of Finland (Baltic Sea). The study shows that the bioelectronic system is suitable for the selected bivalve mollusks Mytilus trossulus, Macoma balthica and Anodonta anatina. Specimens taken from reference sites demonstrated a heart rate recovery time of freshwater and brackish water areas. Development of methodological basis for the testing of adaptive capacities (health) of key aquatic organisms provides new knowledge of biological effects of anthropogenic chemical stress in aquatic organisms.

  7. Borniopsis mortoni sp. n. (Heterodonta, Galeommatoidea, Galeommatidae sensu lato, a new bivalve commensal with a synaptid sea cucumber from Japan

    Directory of Open Access Journals (Sweden)

    Ryutaro Goto

    2016-09-01

    Full Text Available The Galeommatoidea is a bivalve superfamily that exhibits high species diversity in shallow waters. Many members of this superfamily are associated commensally with burrowing marine invertebrates in benthic sediments. The genus Borniopsis is known only from eastern Asia and exhibits high host diversity (e.g., mantis shrimps, crabs, holothurians, sipunculans and echiurans. A new species, Borniopsis mortoni sp. n., is described from mud flats at the mouth of the Souzu River, southwestern Shikoku Island, Japan. This species has elongate-ovate shells covered by a tan to dark brown periostracum, and lives attached by both its foot and byssal threads to the body surface of the synaptid sea cucumber Patinapta ooplax. Several individuals of B. mortoni are often found on the same host, but sometimes more than 10 individuals can occur together. Borniopsis mortoni is one of the smallest species in this genus. Probably, its small body size is an adaptation to the mode of life in a narrow host burrow. Until now, only two other Borniopsis species were known to have commensal associations with synaptids. Thus, this is the third example of a synaptid-associated species from this genus. In addition, we briefly review the galeommatoideans commensal with apodid sea cucumbers.

  8. DICKINSARTELLA FAUNA FROM THE SAIWAN FORMATION (OMAN: A BIVALVE FAUNA TESTIFYING TO THE LATE SAKMARIAN (EARLY PERMIAN CLIMATIC AMELIORATION ALONG THE NORTH-EASTERN GONDWANAN FRINGE.

    Directory of Open Access Journals (Sweden)

    CRISTIANO LARGHI

    2005-11-01

    Full Text Available The transitional faunas of the Permian Huqf succession of Oman make it one of the key-sections for the intercalibration of Early to Middle Permian biostratigraphical scales. The abundance of fossils improved the knowledge of some marine faunas which populated the North-Eastern Gondwanan fringe during times of climatic changes in the Permian. A Sterlitamakian (upper Sakmarian, Lower Permian bivalve fauna from the Saiwan Formation in the Huqf area, informally named "Dickinsartella Fauna", is described in the present paper. The specimens examined were collected from the "Pachycyrtella Bed" (Auctorum, the basal bed of the Formation in its type locality. The Dickinsartella Fauna can be identified for the presence of the new genus Dickinsartella, which dominates the bivalve thanatocoenosis with D. pistacina sp. n. (type species. The bivalve fauna from the Pachycyrtella Bed includes the new species Stutchburia sangallii and Promytilus  mazzolenii, and also Astartella obliqua Dickins, 1963, Nuculopsis cf. bangarraensis Dickins, 1963, ?Oriocrassatella sp., and indeterminable aviculopectinids. This fauna shows a low taxonomic diversity. Nevertheless, some species are represented by a high number of generally well-preserved specimens, i.e. some specimens of S. sangallii sp. n. and A. obliqua show part of the ligament.  The good preservation of the shells permitted the microstructural analysis of D. pistacina sp. n. and S. sangallii sp. n. The microstructure of S. sangallii sp. n. supports the close phylogenetical link between modiomorphids and crassatelloids recognized by some previous authors.The new genus Dickinsartella includes the more recent species belonging to the important Paleozoic Order Cyrtodontida Scarlato & Starobogatov, 1971. The discovery of Dickinsartella gen. n. and other taxa of the Pachycyrtella Bed, present also in the Sakmarian levels of the Carnarvon and Perth Basins in Western Australia,  indicates a wider distribution of the

  9. Veda-scope: More comfortable than the bivalve speculum and cytologically equivalent.

    Science.gov (United States)

    Longmore, Peter G

    2004-04-01

    The aim of the present study was to confirm that the Veda-scope is equivalent to the bivalve speculum in the collection of endocervical cells, as confirmation of adequate cervical sampling for Pap smear testing. The study also aimed to assess the comfort level of the Veda-scope compared to the traditional bivalve speculum and the patient preference of the Veda-scope compared to the bivalve speculum. Multicentre, randomised, controlled crossover, cytologist blinded study. The total number of subjects enrolled in the study were 250. The number of evaluable subjects were 210. In primary efficacy analysis, no significant difference was seen between the presence or absence of endocervical cells in the smears using either the Veda-scope or the bivalve speculum. There was a high concordance level between the diagnosis assigned to each specimen of a paired sample, the diagnosis agreeing in 97.6% cases. The primary reason given by many women for avoidance of regular Pap smear examinations is the discomfort or pain experienced with sample collection with the bivalve speculum. In the present study, 92% of subjects indicated a preference for the Veda-scope for Pap smear collection, while only 8.4% preferred the bivalve speculum. Subject preference was also assessed with respect to how the subject rated the comfort level of her previous Pap smear. In subjects who rated their previous Pap smear as very comfortable or comfortable, 86% expressed a preference for the Veda-scope. This rose to 93% in subjects who rated their previous Pap smear as only tolerable. The results of the present study show that Pap smear collections with the Veda-scope are of equal quality to those collected with the bivalve speculum, with an equivalent diagnostic outcome. A very strong preference for the Veda-scope was shown by the women enrolled in the present study based on the comfort levels experienced with the two devices.

  10. Latitudinal variation in the reproductive cycle of two bivalves with contrasting biogeographical origin along the Humboldt Current Upwelling Ecosystem

    Directory of Open Access Journals (Sweden)

    Roberto A. Uribe

    2012-10-01

    Full Text Available Argopecten purpuratus (Lamarck, 1819 and Mesodesma donacium (Lamarck, 1818 are bivalves that inhabit the Humboldt Current Upwelling Ecosystem. They have contrasting biogeographical origins, suggesting that their responses to exogenous factors should differ. Using circular statistics, we examine synchrony/asynchrony in the reproductive cycle between populations of each species. The results indicate that there is reproductive asynchrony in both species along their distributional range. However, there was synchrony for A. purpuratus in several location-pairs, including Paita-Chimbote, Chimbote-Callao, Callao-Pisco and Pisco-Antofagasta. For M. donacium, there were only two synchronic groups: Camaná-Capellanía-Mehuín and Hornitos-Peñuelas-Longotoma-La Ligua-Cucao-Quilanlar. A. purpuratus showed gametogenenic activity throughout the year. In contrast, M. donacium showed strong seasonality, with gametogenesis in winter and spawning in spring/summer. In conclusion, the patterns observed for these sympatric species suggest that on a large scale the reproductive cycles follow the expected patterns for the contrasting biogeographic origin of each species, so it could be argued that they are modulated by endogenous factors. However, at a local scale, the reproductive cycles of these species show variation, likely determined by local oceanographic or hydrographic processes.

  11. Habitat creation and biodiversity maintenance in mangrove forests: teredinid bivalves as ecosystem engineers

    Directory of Open Access Journals (Sweden)

    Ian W. Hendy

    2014-09-01

    Full Text Available Substantial amounts of dead wood in the intertidal zone of mature mangrove forests are tunnelled by teredinid bivalves. When the tunnels are exposed, animals are able to use tunnels as refuges. In this study, the effect of teredinid tunnelling upon mangrove forest faunal diversity was investigated. Mangrove forests exposed to long emersion times had fewer teredinid tunnels in wood and wood not containing teredinid tunnels had very few species and abundance of animals. However, with a greater cross-sectional percentage surface area of teredinid tunnels, the numbers of species and abundance of animals was significantly higher. Temperatures within teredinid-attacked wood were significantly cooler compared with air temperatures, and animal abundance was greater in wood with cooler temperatures. Animals inside the tunnels within the wood may avoid desiccation by escaping the higher temperatures. Animals co-existing in teredinid tunnelled wood ranged from animals found in terrestrial ecosystems including centipedes, crickets and spiders, and animals found in subtidal marine ecosystems such as fish, octopods and polychaetes. There was also evidence of breeding within teredinid-attacked wood, as many juvenile individuals were found, and they may also benefit from the cooler wood temperatures. Teredinid tunnelled wood is a key low-tide refuge for cryptic animals, which would otherwise be exposed to fishes and birds, and higher external temperatures. This study provides evidence that teredinids are ecosystem engineers and also provides an example of a mechanism whereby mangrove forests support intertidal biodiversity and nurseries through the wood-boring activity of teredinids.

  12. Trace Fossil Evidence of Trematode-Bivalve Parasite-Host Interactions in Deep Time.

    Science.gov (United States)

    Huntley, John Warren; De Baets, Kenneth

    2015-01-01

    Parasitism is one of the most pervasive phenomena amongst modern eukaryotic life and yet, relative to other biotic interactions, almost nothing is known about its history in deep time. Digenean trematodes (Platyhelminthes) are complex life cycle parasites, which have practically no body fossil record, but induce the growth of characteristic malformations in the shells of their bivalve hosts. These malformations are readily preserved in the fossil record, but, until recently, have largely been overlooked by students of the fossil record. In this review, we present the various malformations induced by trematodes in bivalves, evaluate their distribution through deep time in the phylogenetic and ecological contexts of their bivalve hosts and explore how various taphonomic processes have likely biased our understanding of trematodes in deep time. Trematodes are known to negatively affect their bivalve hosts in a number of ways including castration, modifying growth rates, causing immobilization and, in some cases, altering host behaviour making the host more susceptible to their own predators. Digeneans are expected to be significant agents of natural selection. To that end, we discuss how bivalves may have adapted to their parasites via heterochrony and suggest a practical methodology for testing such hypotheses in deep time. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Gene expression and physiological changes of different populations of the long-lived bivalve Arctica islandica under low oxygen conditions.

    Directory of Open Access Journals (Sweden)

    Eva E R Philipp

    Full Text Available The bivalve Arctica islandica is extremely long lived (>400 years and can tolerate long periods of hypoxia and anoxia. European populations differ in maximum life spans (MLSP from 40 years in the Baltic to >400 years around Iceland. Characteristic behavior of A. islandica involves phases of metabolic rate depression (MRD during which the animals burry into the sediment for several days. During these phases the shell water oxygen concentrations reaches hypoxic to anoxic levels, which possibly support the long life span of some populations. We investigated gene regulation in A. islandica from a long-lived (MLSP 150 years German Bight population and the short-lived Baltic Sea population, experimentally exposed to different oxygen levels. A new A. islandica transcriptome enabled the identification of genes important during hypoxia/anoxia events and, more generally, gene mining for putative stress response and (anti- aging genes. Expression changes of a antioxidant defense: Catalase, Glutathione peroxidase, manganese and copper-zinc Superoxide dismutase; b oxygen sensing and general stress response: Hypoxia inducible factor alpha, Prolyl hydroxylase and Heat-shock protein 70; and c anaerobic capacity: Malate dehydrogenase and Octopine dehydrogenase, related transcripts were investigated. Exposed to low oxygen, German Bight individuals suppressed transcription of all investigated genes, whereas Baltic Sea bivalves enhanced gene transcription under anoxic incubation (0 kPa and, further, decreased these transcription levels again during 6 h of re-oxygenation. Hypoxic and anoxic exposure and subsequent re-oxygenation in Baltic Sea animals did not lead to increased protein oxidation or induction of apoptosis, emphasizing considerable hypoxia/re-oxygenation tolerance in this species. The data suggest that the energy saving effect of MRD may not be an attribute of Baltic Sea A. islandica chronically exposed to high environmental variability (oxygenation

  14. Dioxin-like chemicals in bivalves and sediment collected from around Australia

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, J.F.; Muller, R.; Goudkamp, K. [EnTox, The University of Queensland, Brisbane (AU)] (and others)

    2004-09-15

    The aquatic environment is a significant sink for persistent organic pollutants including dioxin-like chemicals. Besides continuous investigations into sources of higher chlorinated PCDD that have initially been found in soils, and later in dugong and sediments little is known about the levels of dioxin-like chemicals in Australia's aquatic environment. In 2002 the National Dioxin Program (NDP) was commissioned by the Department of Environment and Heritage, Australia. One focus of the NDP was to evaluate background levels of dioxin-like chemicals in Australia's environment. One component of the 'Environmental Levels' project aimed to identify dioxinlike chemicals in the aquatic environment including bivalves collected in both marine, estuarine and freshwater systems. Here we report results from the NDP aquatic study with a particular emphasis on the levels of dioxin-like chemicals in bivalves and sediments respectively in areas from where the bivalves were collected.

  15. 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.

  16. 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.

  17. Do mollusks use vertebrate sex steroids as reproductive hormones? Part I: Critical appraisal of the evidence for the presence, biosynthesis and uptake of steroids.

    Science.gov (United States)

    Scott, Alexander P

    2012-11-01

    The consensus view is that vertebrate-type steroids are present in mollusks and perform hormonal roles which are similar to those that they play in vertebrates. Although vertebrate steroids can be measured in molluscan tissues, a key question is 'Are they formed endogenously or they are picked up from their environment?'. The present review concludes that there is no convincing evidence for biosynthesis of vertebrate steroids by mollusks. Furthermore, the 'mollusk' genome does not contain the genes for key enzymes that are necessary to transform cholesterol in progressive steps into vertebrate-type steroids; nor does the mollusk genome contain genes for functioning classical nuclear steroid receptors. On the other hand, there is very strong evidence that mollusks are able to absorb vertebrate steroids from the environment; and are able to store some of them (by conjugating them to fatty acids) for weeks to months. It is notable that the three steroids that have been proposed as functional hormones in mollusks (i.e. progesterone, testosterone and 17β-estradiol) are the same as those of humans. Since humans (and indeed all vertebrates) continuously excrete steroids not just via urine and feces, but via their body surface (and, in fish, via the gills), it is impossible to rule out contamination as the sole reason for the presence of vertebrate steroids in mollusks (even in animals kept under supposedly 'clean laboratory conditions'). Essentially, the presence of vertebrate steroids in mollusks cannot be taken as reliable evidence of either endogenous biosynthesis or of an endocrine role. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  18. SHRIMP (CRANGON-CRANGON L) BROWSING UPON SIPHON TIPS INHIBITS FEEDING AND GROWTH IN THE BIVALVE MACOMA-BALTHICA (L)

    NARCIS (Netherlands)

    KAMERMANS, P; HUITEMA, HJ

    1994-01-01

    The influence of siphon browsing on the feeding behaviour and growth of Macoma balthica, a deposit-feeding bivalve, was studied in three manipulative experiments. Browsing was simulated by removing part of the inhalant siphon with scissors, or studied by exposing the bivalves to shrimps (Crangon

  19. Phenology of abundance of bivalve spat and of their epibenthic predators: limited evidence for mismatches after cold winters

    NARCIS (Netherlands)

    Dekker, R.; Beukema, J.J.

    2014-01-01

    Annual recruitment of bivalves in the Wadden Sea is usually more successful in summers after cold than after mild winters. The new generation (0-group) of the main predators (shrimps and shore crabs) of early benthic stages of bivalves appear later in spring on tidal flats after colder winters. If

  20. An integrated ecosystem approach for assessing the potential role of cultivated bivalve shells as part of the carbon trading system

    NARCIS (Netherlands)

    Filgueira, R.; Byron, C.J.; Comeau, L.A.; Jansen, H.M.; Smaal, A.C.

    2015-01-01

    The role of bivalve mariculture in the CO2 cycle has been commonly evaluated as the balance between respiration, shell calcium carbonate sequestration and CO2 release during biogenic calcification. However, this approach neglects the ecosystem implications of cultivating bivalves at high densities,

  1. In situ method for measurements of community clearance rate on shallow water bivalve populations

    DEFF Research Database (Denmark)

    Hansen, Benni W.; Dolmer, Per; Vismann, Bent

    2011-01-01

    An open-top chamber was designed for measuring ambient community clearance rate on undisturbed bivalve populations in the field. The chamber was pressed 5-10 cm down in the sediment on the mussel bed. It holds approximately 30-40 cm water column equal to a volume of 43-77 L. It was provided...... with an air lift connected to a SCUBA diver pressure tank generating a continuous and gentle water circulation. This ensures a complete mixture of suspended particles, and thereby, a maximum filtration by the bivalves. An in situ fluorometer was mounted to record plant pigment reduction due to mussel...

  2. Otimização do processo de depuração de moluscos bivalves

    OpenAIRE

    Correia, Maria Helena Oliveira Casimiro

    2016-01-01

    A contaminação microbiológica de moluscos bivalves constitui uma das principais preocupações inerentes à segurança alimentar desta importante fonte de receitas para a economia portuguesa. Os bivalves capturados ou produzidos em zonas estuarinas ou lagunares devem passar por um processo de depuração, para redução dos níveis de contaminação microbiológica, antes da sua comercialização. Este trabalho teve como principal objetivo o desenvolvimento de sistemas modulares de dep...

  3. What is hiding behind ontogenic d13C variations in mollusk shells: New insights from scallops.

    Science.gov (United States)

    Chauvaud, L.; Lorrain, A.; Gillikin, D. P.; Thebault, J.; Paulet, Y.; Strand, O.; Blamart, D.; Guarini, J.; Clavier, J.

    2008-12-01

    We examined d13Ccalcite variations along scallop shells (Pecten maximus) sampled in Norway, France and Spain. Time series of shell calcite d13C show a consistent pattern of decreasing d13C with age. This almost linear d13C trend reflects an increasing contribution of metabolic CO2 to skeletal carbonate throughout ontogeny. We have removed this ontogenic trend to try to extract other information from our shell calcite d13C dataset. Scallops from the Bay of Brest (western Brittany, France) were then used to interpret the data as many environmental parameters were available for this site. d13Ccalcite variations were compared to d13C of dissolved inorganic carbon (DIC) and Chl a. The detrended calcite d13C profiles seem to follow a seasonal pattern, but surprisingly are inversely related to the d13C DIC and chlorophyll a concentrations measured within the water column. Theses results suggest that shell d13C variations are not controlled by isotopic variation of DIC. Since scallops eat phytoplankton and microphytobenthos cells, and, as a consequence respire organic mater largely depleted in 13C, we therefore suggest that in mollusk suspension feeders the shell d13Ccalcite might still be used to track the annual number of phytoplankton blooms when d13C values of calcite are detrended. We must consider this trend as a potential biological filter hiding precious environmental records.

  4. Effects of depuration on the element concentration in bivalves: Comparison between sympatric Ruditapes decussatus and Ruditapes philippinarum

    Science.gov (United States)

    Freitas, R.; Ramos Pinto, L.; Sampaio, M.; Costa, A.; Silva, M.; Rodrigues, A. M.; Quintino, V.; Figueira, E.

    2012-09-01

    Organisms living in coastal ecosystems are frequently subjected to anthropogenic pressures such as metals. Metals, especially those not required for metabolic activity (e.g. mercury, lead and cadmium) can be toxic even at quite low concentrations not only to organisms that accumulate them, but also to their consumers. Throughout the world, Ruditapes decussatus and Ruditapes philippinarum have been successfully commercialised for human consumption and for monitoring environmental conditions such as contamination. These two clam species share similar habitats and requirements, successfully competing both in the natural environment and in aquaculture farms. Because differences in metal accumulation may exist between R. decussatus and R. philippinarum, different risks to public health may overcome as well as distinct ecological implications. The effect of depuration on the metal burden and biochemical status of both clams species may also diverge and since the information available is subjective and scarce, the aims of the present study were to: 1) assess the total metal accumulation and intracellular partitioning, at natural conditions, in the two clam species collected at the same site; 2) evaluate the effect of depuration as a mean of reducing the levels of distinct elements, assessing also the effect of depuration time (2 and 7 days); 3) investigate the efficiency of depuration by biochemical status of the two bivalve species, evaluating changes in lipid peroxidation and activity of antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and of glutathione S-transferase (GST). Metal chelation by metallothioneins (MTs) was also determined. The results obtained showed that concentration of elements in clams was low, presenting very similar concentration levels for all elements. The present work further demonstrated that the total element concentration decreased in the shorter depuration period (2 days) and that R. decussatus and R. philippinarum partitioned

  5. Processes of physical change to the seabed and bivalve recruitment over a 10-year period following experimental hydraulic clam dredging on Banquereau, Scotian Shelf

    Science.gov (United States)

    Gilkinson, K.; King, E. L.; Li, M. Z.; Roddick, D.; Kenchington, E.; Han, G.

    2015-01-01

    A previous study on the effects of experimental hydraulic clam dredging on seabed habitat and commercial bivalve populations revealed a lack of recovery after a 3-year post-dredging period (1998-2001) on a deep (65-75 m) offshore sandy bank on the Scotian Shelf, Canada. Follow-up sidescan sonar surveys were carried out 5 and 10 years after dredging (2003, 2008) in order to identify long-term processes of seabed recovery. Grab sampling was carried out 10 years after dredging to identify post-dredging commercial bivalve recruitment. Changes in the seafloor, including dredge tracks, were documented with a series of 7 sidescan sonar surveys between 1998 and 2008. A sediment mobility model was constructed based on modeled tidal current and hindcast wave data over this time period to quantify natural seabed disturbance and interpret changes to the dredge tracks mapped by sidescan sonar surveys. The model indicated that tidal currents had minimal effect on sediment mobilization. The main driving force associated with re-working of surficial sediments as evidenced by deterioration of dredge tracks in sonograms was annual fall/winter storms. While the annual frequency of storms and associated wave heights was variable, the observations and sediment mobility calculations suggest that the most influential variable is the magnitude of individual large storms, specifically storms with a significant wave height of ∼11 m. These storms are capable of generating mobile sediment layers of 20-30 cm thickness, equivalent to the dredge blade cutting depth. It appears that, with minor exceptions, sediment properties have returned to pre-dredging conditions 10 years after dredging in this habitat. Based on known age-length relationships, the four commercial bivalve species showed very low recruitment at the experimental site over the 10-year post-dredging period. However, this is unlikely due to a dredging effect since a similar pattern was observed in non-dredged areas.

  6. Direct injection of tissue extracts in liquid chromatography/tandem mass spectrometry for the determination of pharmaceuticals and other contaminants of emerging concern in mollusks.

    Science.gov (United States)

    Bayen, Stéphane; Estrada, Elvagris Segovia; Juhel, Guillaume; Kelly, Barry C

    2015-07-01

    In the present study, a straightforward approach was validated for the analysis of pharmaceutically active compounds and endocrine-disrupting chemicals in the mollusk tissues, with a focus on two species commonly consumed in Southeast Asia (green mussels: Perna viridis; lokan clams: Polymesoda expansa). This approach relied on a simple solvent extraction (shaker table) followed by direct injection in liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). This "cleanup-free" approach was made possible by the use of isotopically labeled surrogates (to correct for matrix effects) and a post-column switch on the LC-MS/MS system (to remove potential interfering material). Altogether, relative recoveries were satisfactory for 36 out of 44 compounds (26-163% range) and excellent for 27 out of 44 compounds (79-107% range). Method detection limits (MDLs) were usually expressed in the nanogram per gram wet weight (ww) range and below. The method was successfully applied to 16 batches of green mussel samples collected in Singapore coastal waters. Trace levels of six compounds were detected in mussel tissues: caffeine (0.22-1.55 ng g(-1) ww), carbamazepine (

  7. Differing responses of the estuarine bivalve Limecola balthica to lowered water pH caused by potential CO2 leaks from a sub-seabed storage site in the Baltic Sea: An experimental study.

    Science.gov (United States)

    Sokołowski, Adam; Brulińska, Dominika; Mirny, Zuzanna; Burska, Dorota; Pryputniewicz-Flis, Dorota

    2018-02-01

    Sub-Seabed CCS is regarded as a key technology for the reduction of CO 2 emissions, but little is known about the mechanisms through which leakages from storage sites impact benthic species. In this study, the biological responses of the infaunal bivalve Limecola balthica to CO 2 -induced seawater acidification (pH7.7, 7.0, and 6.3) were quantified in 56-day mesocosm experiments. Increased water acidity caused changes in behavioral and physiological traits, but even the most acidic conditions did not prove to be fatal. In response to hypercapnia, the bivalves approached the sediment surface and increased respiration rates. Lower seawater pH reduced shell weight and growth, while it simultaneously increased soft tissue weight; this places L. balthica in a somewhat unique position among marine invertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. An ecosystem-based approach and management framework for the integrated evaluation of bivalve aquaculture impacts

    NARCIS (Netherlands)

    Cranford, P.J.; Kamermans, P.; Krause, G.H.M.; Mazurie, J.

    2012-01-01

    An ecosystem-based approach to bivalve aquaculture management is a strategy for the integration of aquaculture within the wider ecosystem, including human aspects, in such a way that it promotes sustainable development, equity, and resilience of ecosystems. Given the linkage between social and

  9. Burrowing Behavior of a Deposit Feeding Bivalve Predicts Change in Intertidal Ecosystem State

    NARCIS (Netherlands)

    Compton, T.J.; Bodnar, W.; Koolhaas, A.; Dekinga, A.; Holthuijsen, S.; Ten Horn, J.; McSweeney, N.; van Gils, J.A.; Piersma, T.

    2016-01-01

    Behavior has a predictive power that is often underutilized as a tool for signaling ecological change. The burrowing behavior of the deposit feeding bivalve Macoma balthica reflects a typical food-safety trade-off. The choice to live close to the sediment surface comes at a risk of predation and is

  10. Burrowing behavior of a deposit feeding bivalve predicts change in intertidal ecosystem state

    NARCIS (Netherlands)

    Compton, Tanya J.; Bodnar, Wanda; Koolhaas, Anita; Dekinga, Anne; Holthuijsen, Sander; ten Horn, Job; McSweeney, Niamh; van Gils, Jan; Piersma, Theunis

    2016-01-01

    Behavior has a predictive power that is often underutilized as a tool for signaling ecological change. The burrowing behavior of the deposit feeding bivalve Macoma balthica reflects a typical food-safety trade-off. The choice to live close to the sediment surface comes at a risk of predation and is

  11. Bivalve grazing, nutrient cycling and phytoplankton dynamics in an estuarine ecosystem

    NARCIS (Netherlands)

    Prins, T.C.

    1996-01-01


    This thesis has considered the impact of the suspension feeding bivalve Mytilusedulis on nutrient cycling and phytoplankton in an estuarine ecosystem. The research was started within the framework of an extensive research project with the

  12. Predation on intertidal mussels: Influence of biotic factors on the survival of epibenthic bivalve beds

    NARCIS (Netherlands)

    Waser, A.M.

    2018-01-01

    Coastal areas are amongst the most productive ecosystems in the world. Important components of these coastal areas are reef-forming bivalves such as mussels and oysters, as they have important facilitating effects on many associated organisms through the provision of substratum,

  13. The oxygen-binding properties of hemocyanin from the mollusk Concholepas concholepas.

    Science.gov (United States)

    González, Andrea; Nova, Esteban; Del Campo, Miguel; Manubens, Augusto; De Ioannes, Alfredo; Ferreira, Jorge; Becker, María Inés

    2017-12-01

    Hemocyanins have highly conserved copper-containing active sites that bind oxygen. However, structural differences among the hemocyanins of various mollusks may affect their physicochemical properties. Here, we studied the oxygen-binding cooperativity and affinity of Concholepas concholepas hemocyanin (CCH) and its two isolated subunits over a wide range of temperatures and pH values. Considering the differences in the quaternary structures of CCH and keyhole limpet hemocyanin (KLH), we hypothesized that the heterodidecameric CCH has different oxygen-binding parameters than the homodidecameric KLH. A novel modification of the polarographic method was applied in which rat liver submitochondrial particles containing cytochrome c oxidase were introduced to totally deplete oxygen of the test solution using ascorbate as the electron donor. This method was both sensitive and reproducible. The results showed that CCH, like other hemocyanins, exhibits cooperativity, showing an inverse relationship between the oxygen-binding parameters and temperature. According to their Hill coefficients, KLH has greater cooperativity than CCH at physiological pH; however, CCH is less sensitive to pH changes than KLH. Appreciable differences in binding behavior were found between the CCH subunits: the cooperativity of CCH-A was not only almost double that of CCH-B, but it was also slightly superior to that of CCH, thus suggesting that the oxygen-binding domains of the CCH subunits are different in their primary structure. Collectively, these data suggest that CCH-A is the main oxygen-binding domain in CCH; CCH-B may play a more structural role, perhaps utilizing its surprising predisposition to form tubular polymers, unlike CCH-A, as demonstrated here using electron microscopy. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Determination of the toxic variability of lipophilic biotoxins in marine bivalve and gastropod tissues treated with an industrial canning process.

    Science.gov (United States)

    García, Carlos; Oyaneder-Terrazas, Javiera; Contreras, Cristóbal; Del Campo, Miguel; Torres, Rafael; Contreras, Héctor R

    2016-11-01

    Contamination of shellfish with lipophilic marine biotoxins (LMB), pectenotoxins (PTXs), yessotoxins (YTXs) and okadaic acid (OA) toxin groups in southern Chile is a constant challenge for the development of miticulture considering the high incidence of toxic episodes that tend to occur. This research is focused on using methodologies for assessing the decrease in toxins of natural resources in Chile with high value, without altering the organoleptic properties of the shellfish. The species were processed through steaming (1 min at 121°C) and subsequent canning (5 min at 121°C). Changes in the profiles of toxins and total toxicity levels of LMB in endemic bivalves and gastropods were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The total reduction of toxicity (≈ 15%) was not related to the destruction of the toxin, but rather to the loss of LMB on removing the shells and packing media of canned products (***p < 0.001). Industrial processing of shellfish reduces LMB contents by up to 15% of the total initial contents, concomitant only with the interconversion of PTX-group toxins into PTX-2sa. In soft bottom-dwelling species with toxicities beyond the standard for safe human consumption (≥ 160 μg OA-eq kg - 1 ), toxicity can be reduced to safe levels through industrial preparation procedures.

  15. Factors influencing the microplastic contamination of bivalves from the French Atlantic coast: Location, season and/or mode of life?

    Science.gov (United States)

    Phuong, Nam Ngoc; Poirier, Laurence; Pham, Quoc Tuan; Lagarde, Fabienne; Zalouk-Vergnoux, Aurore

    2018-04-01

    Monitoring the presence of microplastics (MP) in marine organisms is currently of high importance. This paper presents the qualitative and quantitative MP contamination of two bivalves from the French Atlantic coasts: the blue mussel (Mytilus edulis) and the Pacific oyster (Crassostrea gigas). Three factors potentially influencing the contamination were investigated by collecting at different sampling sites and different seasons, organisms both wild and cultivated. Inter- and intra-species comparisons were also achieved. MP quantity in organisms was evaluated at 0.61±0.56 and 2.1±1.7MP per individual respectively for mussels and oysters. Eight different polymers were identified. Most of the MPs were fragments; about a half of MPs were grey colored and a half with a size ranging from 50 to 100μm for both studied species. Some inter-specific differences were found but no evidence for sampling site, season or mode of life effect was highlighted. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. 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.

  17. Comparison of visual observation and excavation to quantify density of the endangered bivalve Unio crassus in rivers of north-eastern France

    Directory of Open Access Journals (Sweden)

    Lamand F.

    2014-04-01

    Full Text Available In the context of a rapid decline in several protected unionid species, government agencies urgently require a reliable method to estimate population size for the most endangered species. We used a dataset collected from 16 river stations in north-eastern France to compare the efficiency of visual estimation (bathyscope and a manual excavation to estimate numbers of the endangered bivalve Unio crassus. Our investigations indicated that, whereas a visual approach was sufficient to detect unionid presence, only 10% of all individuals were registered compared with manual excavation at the same site. In order to obtain an accurate density estimate (especially as regards the juvenile population, sediment excavation is necessary, despite it being time consuming and damaging to the mussel’s habitat.

  18. Characterization of freshwater bivalves as radio contamination (57Co, 110mAg, 134Cs) bio-indicators in a metallic multi pollution context (Cd, Zn)

    International Nuclear Information System (INIS)

    Fraysse, B.

    2001-07-01

    This study concerns freshwater bio-indicators of radio-contamination, in a metallic multi-pollution context. Metals, such as cadmium (Cd) and zinc (Zn), are widely represented in aquatic ecosystems, and their concentrations can induce physiological effects. This chronicle exposure generates both metabolic and behaviour stress of individuals, and can also yield to detoxification mechanisms induction. The main goal of this work was to estimate the influence of metals on the radionuclides ( 57 Co, 110m Ag, 134 Cs) bioaccumulation by two different bivalve species (Corbicula fluminea et Dreissena polymorpha), by studying the contamination level, the kinetic of the radionuclide transfer and the soft-body repartition. As the exploratory feature of this study, two parts have been developed: (i) testing the problematic suitability in a really bio-monitoring situation, and (ii) analysing the metal/radionuclide interaction mechanisms under controlled and standardised conditions (laboratory). For the different experimental conditions explored (laboratory and field), radionuclide bioaccumulation by freshwater bivalves has been influenced by metal exposure. This result was obtained after assessing a decrease of the organisms contamination level by radionuclide and their accumulation rate, an increase of their depuration rate and tissue and cellular repartition changes. (author)

  19. Do mollusks use vertebrate sex steroids as reproductive hormones? II. Critical review of the evidence that steroids have biological effects.

    Science.gov (United States)

    Scott, Alexander P

    2013-02-01

    In assessing the evidence as to whether vertebrate sex steroids (e.g. testosterone, estradiol, progesterone) have hormonal actions in mollusks, ca. 85% of research papers report at least one biological effect; and 18 out of 21 review papers (published between 1970 and 2012) express a positive view. However, just under half of the research studies can be rejected on the grounds that they did not actually test steroids, but compounds or mixtures that were only presumed to behave as steroids (or modulators of steroids) on the basis of their effects in vertebrates (e.g. Bisphenol-A, nonylphenol and sewage treatment effluents). Of the remaining 55 papers, some can be criticized for having no statistical analysis; some for using only a single dose of steroid; others for having irregular dose-response curves; 40 out of the 55 for not replicating the treatments; and 50 out of 55 for having no within-study repetition. Furthermore, most studies had very low effect sizes in comparison to fish-based bioassays for steroids (i.e. they had a very weak 'signal-to-noise' ratio). When these facts are combined with the fact that none of the studies were conducted with rigorous randomization or 'blinding' procedures (implying the possibility of 'operator bias') one must conclude that there is no indisputable bioassay evidence that vertebrate sex steroids have endocrinological or reproductive roles in mollusks. The only observation that has been independently validated is the ability of estradiol to trigger rapid (1-5 min) lysosomal membrane breakdown in hemocytes of Mytilus spp. This is a typical 'inflammatory' response, however, and is not proof that estradiol is a hormone - especially when taken in conjunction with the evidence (discussed in a previous review) that mollusks have neither the enzymes necessary to synthesize vertebrate steroids nor nuclear receptors with which to respond to them. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  20. Nyctemeral variations of magnesium intake in the calcitic layer of a Chilean mollusk shell ( Concholepas concholepas, Gastropoda)

    Science.gov (United States)

    Lazareth, Claire E.; Guzman, Nury; Poitrasson, Franck; Candaudap, Frederic; Ortlieb, Luc

    2007-11-01

    Mollusk shells are increasingly used as records of past environmental conditions, particularly for sea-surface temperature (SST) reconstructions. Many recent studies tackled SST (and/or sea-surface salinity) tracers through variations in the elementary (Mg and Sr) or stable isotope (δ 18O) composition within mollusk shells. But such attempts, which sometimes include calibration studies on modern specimens, are not always conclusive. We present here a series of Mg and Sr analyses in the calcitic layer of Concholepas concholepas (Muricidae, Gastropoda) with a very high time-resolution on a time window covering about 1 and a half month of shell formation, performed by Laser Ablation Inductively-Coupled Plasma Mass Spectrometry (LA-ICP-MS) and electron probe micro-analysis (EPMA). The selected specimen of this common Chilean gastropod was grown under controlled environmental conditions and precise weekly time-marks were imprinted in the shell with calcein staining. Strontium variations in the shell are too limited to be interpreted in terms of environmental parameter changes. In contrast, Mg incorporation into the shell and growth rate appear to change systematically between night and day. During the day, Mg is incorporated at a higher rate than at night and this intake seems positively correlated with water temperature. The nightly reduced Mg incorporation is seemingly related to metabolically controlled processes, formation of organic-rich shell increments and nocturnal feeding activity of the animals. The nyctemeral Mg changes in the C. concholepas shell revealed in this study might explain at least part of the discrepancies observed in previous studies on the use of Mg as a SST proxy in mollusk shells. In the case of C. concholepas, Mg cannot be used straightforwardly as a SST proxy.

  1. Cross-habitat interactions among bivalve species control community structure on intertidal flats

    NARCIS (Netherlands)

    Donadi, S.; van der Heide, T.; van der Zee, E.M.; Eklöf, J.S.; van de Koppel, J.; Weerman, E.J.; Piersma, T.; Olff, H.; Eriksson, B.K.

    2013-01-01

    Increasing evidence shows that spatial interactions between sedentary organisms can structure communities and promote landscape complexity in many ecosystems. Here we tested the hypothesis that reef-forming mussels (Mytilus edulis L.), a dominant intertidal ecosystem engineer in the Wadden Sea,

  2. Cross-habitat interactions among bivalve species control community structure on intertidal flats

    NARCIS (Netherlands)

    Donadi, Serena; van der Heide, Tjisse; van der Zee, Els M.; Eklöf, Johan S.; van de Koppel, Johan; Weerman, Ellen J.; Piersma, Theunis; Olff, Han; Eriksson, Britas Klemens

    Increasing evidence shows that spatial interactions between sedentary organisms can structure communities and promote landscape complexity in many ecosystems. Here we tested the hypothesis that reef-forming mussels (Mytilus edulis L.), a dominant intertidal ecosystem engineer in the Wadden Sea,

  3. Some effects of temperature and starvation on the bivalve @iDonax vittatus@@ (da Costa) in experimental laboratory populations

    Digital Repository Service at National Institute of Oceanography (India)

    Ansell, A.D.; Sivadas, P.

    The effect of temperature on the body weight and composition, and on respiration, filtration and NH, excretion of the bivalve Donax uittatus (da Costa) has been investigated in laboratory-maintained populations under conditions of starvation In all...

  4. 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

  5. Assessment of Toxic Metals and feed habits of the snail Pomacea specie from the Amatitlan Lake

    International Nuclear Information System (INIS)

    Roesch Palomo, R.R.

    1998-01-01

    In the present thesis an assesment of cadmium, cooper, cromium VI, and lead was made in samples of snail pomacea specie from the Amatitlan Lake. We conclude that the comsuption of this mollusk is toxic for human health. The concentration of heavy metals like cadmium, cooper shows that are not recomended for human comsuption according to Spanish and FAO/PAHO standards

  6. The accumulation of radionuclides by Dreissena polymorpha molluscs - The Accumulation of Radionuclides from Water and Food in the Dreissena polymorpha Mollusks

    Energy Technology Data Exchange (ETDEWEB)

    Jefanova, O.; Marciulioniene, D. [Nature Research Centre, Akademijos str. 2, LT-08412 Vilnius, Lietuva (Lithuania)

    2014-07-01

    The specific activity of {sup 137}Cs, {sup 60}Co, {sup 54}Mn, {sup 90}Sr was measured in mollusks Dreissena polymorpha samples from lake Drukshiai that is the cooling pond of the Ignalina NPP. Item the accumulation of {sup 137}Cs, {sup 90}Sr, {sup 144}Ce, {sup 106}Ru in the mollusks from water and from phytoplankton which is a part of their diet was evaluated under laboratory conditions. The data of long-term (1991-2009) studies conducted at six monitoring stations of lake Drukshiai show that in 1991 {sup 137}Cs in mollusks Dreissena polymorpha was found only in that lake's area which was influenced by the effluent that got into lake from the industrial drainage channel of Ignalina NPP. In later periods of the investigation the {sup 137}Cs specific activity was detected in mollusks samples which had been collected at other monitoring stations (the aquatory of lake Drukshiai). Meanwhile {sup 60}Co and {sup 54}Mn in Dreissena polymorpha were detected only in that lake's area which was impacted by the industrial drainage channel. The data of long-term investigation show that the major amount of radionuclides has come into lake Drukshiai through the industrial drainage system of Ignalina NPP. Albeit {sup 137}Cs, {sup 90}Sr, {sup 144}Ce, {sup 106}Ru get into the mollusks through a large amount of the water rather than from the food (phytoplankton), therefore the food can also be the main source of radionuclides in the organism of these mollusks in aquatic environment when there are low levels of specific activities of these radionuclides. (authors)

  7. Assessing the effects of seawater temperature and pH on the bioaccumulation of emerging chemical contaminants in marine bivalves.

    Science.gov (United States)

    Maulvault, Ana Luísa; Camacho, Carolina; Barbosa, Vera; Alves, Ricardo; Anacleto, Patrícia; Fogaça, Fabiola; Kwadijk, Christiaan; Kotterman, Michiel; Cunha, Sara C; Fernandes, José O; Rasmussen, Rie R; Sloth, Jens J; Aznar-Alemany, Òscar; Eljarrat, Ethel; Barceló, Damià; Marques, António

    2018-02-01

    Emerging chemical contaminants [e.g. toxic metals speciation, flame retardants (FRs) and perfluorinated compounds (PFCs), among others], that have not been historically recognized as pollutants nor their toxicological hazards, are increasingly more present in the marine environment. Furthermore, the effects of environmental conditions (e.g. temperature and pH) on bioaccumulation and elimination mechanisms of these emerging contaminants in marine biota have been poorly studied until now. In this context, the aim of this study was to assess, for the first time, the effect of warmer seawater temperatures (Δ = + 4°C) and lower pH levels (Δ = - 0.4 pH units), acting alone or combined, on the bioaccumulation and elimination of emerging FRs (dechloranes 602, 603 and 604, and TBBPA), inorganic arsenic (iAs), and PFCs (PFOA and PFOS) in two estuarine bivalve species (Mytilus galloprovincialis and Ruditapes philippinarum). Overall, results showed that warming alone or combined with acidification promoted the bioaccumulation of some compounds (i.e. dechloranes 602, 604, TBBPA), but also facilitated the elimination of others (i.e. iAs, TBBPA). Similarly, lower pH also resulted in higher levels of dechloranes, as well as enhanced iAs, PFOA and PFOS elimination. Data also suggests that, when both abiotic stressors are combined, bivalves' capacity to accumulate contaminants may be time-dependent, considering significantly drastic increase observed with Dec 602 and TBBPA, during the last 10 days of exposure, when compared to reference conditions. Such changes in contaminants' bioaccumulation/elimination patterns also suggest a potential increase of human health risks of some compounds, if the climate continues changing as forecasted. Therefore, this first study pointed out the urgent need for further research on the effects of abiotic conditions on emerging contaminants kinetics, to adequately estimate the potential toxicological hazards associated to these compounds and

  8. An ecosystem-based approach and management framework for the integrated evaluation of bivalve aquaculture impacts

    DEFF Research Database (Denmark)

    Cranford, Peter J.; Kamermans, Pauline; Krause, Gesche

    2012-01-01

    for bivalve aquaculture be based on a tiered indicator monitoring system that is structured on the principle that increased environmental risk requires increased monitoring effort. More than 1 threshold for each indicator would permit implementation of predetermined impact prevention and mitigation measures......An ecosystem-based approach to bivalve aquaculture management is a strategy for the integration of aquaculture within the wider ecosystem, including human aspects, in such a way that it promotes sustainable development, equity, and resilience of ecosystems. Given the linkage between social...... and ecological systems, marine regulators require an ecosystem-based decision framework that structures and integrates the relationships between these systems and facilitates communication of aquaculture–environment interactions and policy-related developments and decisions. The Drivers-Pressures-State Change-Impact-Response...

  9. Benzene Synthesis for ''14C Measurements and Evaluation of Uncertainty in Mollusk Shells; Sintesis de Benceno para la Determinacion de C''14 y Evaluacion de su Incertidumbre en Conchas de Moluscos

    Energy Technology Data Exchange (ETDEWEB)

    Romero del Hombrebueno, B.; Simon, M. A.; Larena, P.

    2002-07-01

    This work describes the method and instrumentation used by Environmental Isotopes laboratory of the CIEMAT Analytical Chemistry Laboratory (DIAE) for the synthesis of benzene from carbonates of mollusk shells and the liquid scintillation counting of ''14C for radiocarbon dating in these samples. The usefulness of mollusk shells for ''14 C dating are considered. (Author)

  10. Interactive effects of metal contamination and pathogenic organisms on the introduced marine bivalve Ruditapes philippinarum in European populations

    International Nuclear Information System (INIS)

    Paul-Pont, Ika; Montaudouin, Xavier de; Gonzalez, Patrice; Jude, Florence; Raymond, Natalie; Paillard, Christine; Baudrimont, Magalie

    2010-01-01

    In natural environment, marine organisms are concomitantly exposed to pollutants and multiple disease agents resulting in detrimental interactions. The present study evaluated interactive effects of metal contamination (cadmium) and pathogenic organisms (trematode parasites Himasthla elongata and pathogenic bacteria Vibrio tapetis) singularly and in combination on the bivalve Ruditapes philippinarum, an introduced species to Europe, under laboratory controlled conditions. After 7 days, metal bioaccumulation and pathogen load were analyzed as well as metallothionein (MT) response and hemocyte concentrations and activities. Results showed that infection by opportunistic pathogens affects metal accumulation, leading to maximal Cd accumulation in co-infected clams. Among stressors only V. tapetis induced significant effects on immune parameters whereas a particular interaction 'trematode-bacteria' was shown on MT responses. Despite low trematode infection in agreement with the resistant status of R. philippinarum to these macroparasites, significant interaction with bacteria and metal occurred. Such results highlight the necessity of taking pathogens into account in ecotoxicological studies. - Co-infection by opportunistic pathogens affects metal accumulation and some defense-related activities in the Manila clam Ruditapes philippinarum.

  11. Interactive effects of metal contamination and pathogenic organisms on the introduced marine bivalve Ruditapes philippinarum in European populations

    Energy Technology Data Exchange (ETDEWEB)

    Paul-Pont, Ika, E-mail: i.paulpont@epoc.u-bordeaux1.f [Universite Bordeaux 1, UMR 5805 CNRS, Station Marine d' Arcachon, place du Dr. Peyneau, Arcachon 33120 (France); Montaudouin, Xavier de; Gonzalez, Patrice; Jude, Florence; Raymond, Natalie [Universite Bordeaux 1, UMR 5805 CNRS, Station Marine d' Arcachon, place du Dr. Peyneau, Arcachon 33120 (France); Paillard, Christine [Universite de Bretagne Occidentale-IUEM, LEMAR UMR 6539 CNRS, Place Nicolas Copernic, Technopole Brest Iroise, 29280 Plouzane (France); Baudrimont, Magalie [Universite Bordeaux 1, UMR 5805 CNRS, Station Marine d' Arcachon, place du Dr. Peyneau, Arcachon 33120 (France)

    2010-11-15

    In natural environment, marine organisms are concomitantly exposed to pollutants and multiple disease agents resulting in detrimental interactions. The present study evaluated interactive effects of metal contamination (cadmium) and pathogenic organisms (trematode parasites Himasthla elongata and pathogenic bacteria Vibrio tapetis) singularly and in combination on the bivalve Ruditapes philippinarum, an introduced species to Europe, under laboratory controlled conditions. After 7 days, metal bioaccumulation and pathogen load were analyzed as well as metallothionein (MT) response and hemocyte concentrations and activities. Results showed that infection by opportunistic pathogens affects metal accumulation, leading to maximal Cd accumulation in co-infected clams. Among stressors only V. tapetis induced significant effects on immune parameters whereas a particular interaction 'trematode-bacteria' was shown on MT responses. Despite low trematode infection in agreement with the resistant status of R. philippinarum to these macroparasites, significant interaction with bacteria and metal occurred. Such results highlight the necessity of taking pathogens into account in ecotoxicological studies. - Co-infection by opportunistic pathogens affects metal accumulation and some defense-related activities in the Manila clam Ruditapes philippinarum.

  12. Laboratory and field assessment of uranium trophic transfer efficiency in the crayfish Orconectes limosus fed the bivalve C. fluminea

    International Nuclear Information System (INIS)

    Simon, Olivier; Garnier-Laplace, Jacqueline

    2005-01-01

    At present, ecotoxicological information regarding the impact of natural uranium (U) on freshwater ecosystems via the trophic contamination route is scarce. We generated an experimental trophic food chain involving the prey species, Corbicula fluminea, and a predator, Orconectes limosus, for a 10-day and a 30-day feeding periods (food ration: one whole soft body/day/crayfish). We studied the efficiency of U trophic transfer and the distribution of U in the predator. During the test, we varied the quantity of dietary U (from beforehand contaminated bivalves at concentrations ranging from 0.9 ± 0.1 to 20.2 ± 9 μg/g fw provided to each crayfish over the 10 days) applying a daily feeding rate equal to 3.9 ± 0.8% fw. The efficiency of U trophic transfer from clams to crayfish varied between 1 and 13% depending on the prey exposure modalities. Accumulation of U was observed in the digestive gland but also in gills, in the muscle, and in the molt of the crayfish after trophic exposure treatments. Under high-level exposure conditions, the digestive gland was the main target-organ, however a significant accumulation was also observed in the stomach. With regard to low levels of trophic exposure, accumulation of U in gills, in the stomach, and in the digestive gland was of the same order of magnitude. Longer exposure period which incorporated a crayfish molt, resulted in a decrease of trophic transfer ratio and a modified U tissue distribution

  13. Bathymetric and geographic population structure in the pan-Atlantic deep-sea bivalve Deminucula atacellana (Schenck, 1939).

    Science.gov (United States)

    Zardus, John D; Etter, Ron J; Chase, Michael R; Rex, Michael A; Boyle, Elizabeth E

    2006-03-01

    The deep-sea soft-sediment environment hosts a diverse and highly endemic fauna of uncertain origin. We know little about how this fauna evolved because geographic patterns of genetic variation, the essential information for inferring patterns of population differentiation and speciation are poorly understood. Using formalin-fixed specimens from archival collections, we quantify patterns of genetic variation in the protobranch bivalve Deminucula atacellana, a species widespread throughout the Atlantic Ocean at bathyal and abyssal depths. Samples were taken from 18 localities in the North American, West European and Argentine basins. A hypervariable region of mitochondrial 16S rDNA was amplified by polymerase chain reaction (PCR) and sequenced from 130 individuals revealing 21 haplotypes. Except for several important exceptions, haplotypes are unique to each basin. Overall gene diversity is high (h = 0.73) with pronounced population structure (Phi(ST) = 0.877) and highly significant geographic associations (P < 0.0001). Sequences cluster into four major clades corresponding to differences in geography and depth. Genetic divergence was much greater among populations at different depths within the same basin, than among those at similar depths but separated by thousands of kilometres. Isolation by distance probably explains much of the interbasin variation. Depth-related divergence may reflect historical patterns of colonization or strong environmental selective gradients. Broadly distributed deep-sea organisms can possess highly genetically divergent populations, despite the lack of any morphological divergence.

  14. Microbial Communities in Sunken Wood Are Structured by Wood-Boring Bivalves and Location in a Submarine Canyon

    Science.gov (United States)

    Fagervold, Sonja K.; Romano, Chiara; Kalenitchenko, Dimitri; Borowski, Christian; Nunes-Jorge, Amandine; Martin, Daniel; Galand, Pierre E.

    2014-01-01

    The cornerstones of sunken wood ecosystems are microorganisms involved in cellulose degradation. These can either be free-living microorganisms in the wood matrix or symbiotic bacteria associated with wood-boring bivalves such as emblematic species of Xylophaga, the most common deep-sea woodborer. Here we use experimentally submerged pine wood, placed in and outside the Mediterranean submarine Blanes Canyon, to compare the microbial communities on the wood, in fecal pellets of Xylophaga spp. and associated with the gills of these animals. Analyses based on tag pyrosequencing of the 16S rRNA bacterial gene showed that sunken wood contained three distinct microbial communities. Wood and pellet communities were different from each other suggesting that Xylophaga spp. create new microbial niches by excreting fecal pellets into their burrows. In turn, gills of Xylophaga spp. contain potential bacterial symbionts, as illustrated by the presence of sequences closely related to symbiotic bacteria found in other wood eating marine invertebrates. Finally, we found that sunken wood communities inside the canyon were different and more diverse than the ones outside the canyon. This finding extends to the microbial world the view that submarine canyons are sites of diverse marine life. PMID:24805961

  15. An ecosystem-based approach and management framework for the integrated evaluation of bivalve aquaculture impacts

    OpenAIRE

    Cranford, Peter J.; Kamermans, Pauline; Krause, Gesche; Mazurie, Joseph; Buck, Bela H.; Dolmer, Per; Fraser, David; Van Nieuwenhove, Kris; O'Beirn, Francis X.; Sanchez-mata, Adoracion; Thorarinsdottir, Gudrun G.; Strand, Oivind

    2012-01-01

    An ecosystem-based approach to bivalve aquaculture management is a strategy for the integration of aquaculture within the wider ecosystem, including human aspects, in such a way that it promotes sustainable development, equity, and resilience of ecosystems. Given the linkage between social and ecological systems, marine regulators require an ecosystem-based decision framework that structures and integrates the relationships between these systems and facilitates communication of aquaculture–en...

  16. Impact of seawater carbonate chemistry on the calcification of marine bivalves

    OpenAIRE

    Thomsen Jörn; Haynert Kristin; Wegner K Mathias; Melzner Frank

    2015-01-01

    Bivalve calcification, particular of the early larval stages is highly sensitive to the change of ocean carbonate chemistry resulting from atmospheric CO2 uptake. Earlier studies suggested that declining seawater [CO32−] and thereby lowered carbonate saturation affect shell production. However, disturbances of physiological processes such as acid-base regulation by adverse seawater pCO2 and pH can affect calcification in a secondary fashion. In order to determine the e...

  17. 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.

  18. 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.

  19. Marine pollution detection through biomarkers in marine bivalves

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Pereira, N.; Desai, S.R.; Jena, K.B.; Snigdha

    ous physiological and biochemical parameters in resident b i ota. Use of the so - called ?biomarker? has been adopted from i demiology? or ?molecular toxicology? by free - radical biologists to describe changes in biolog i cal molec ules out... of attack by free radicals like oxygen, nitrogen or ha l- ide species, in dealing with aquatic toxico l ogy 6 . In this context, the cytochrome P450 - linked mixed function ox y- genase (MFO) enzyme system has been extensively stu d ied 7...

  20. Protecting rare, old-growth, forest-associated species under the Survey and Manage program guidelines of the northwest forest plan.

    Science.gov (United States)

    Randy Molina; Bruce G. Marcot; Robin. Lesher

    2006-01-01

    The Survey and Manage Program of the Northwest Forest Plan (MFP) represents an unparalleled attempt to protect rare, little-known species associated with late-successional and old-growth forests on more than 7.7 million ha of federal lands. Approximately 400 species of amphibians, bryophytes, fungi, lichens, mollusks, vascular plants, arthropod functional groups, and...

  1. The brackish-water bivalve Waagenoperna from the Lower Jurassic Badaowan Formation of the Junggar Basin and its palaeoenvironmental and palaeogeographic significance

    Directory of Open Access Journals (Sweden)

    Yanhong Pan

    2013-01-01

    Full Text Available The brackish-water bivalve Waagenoperna Tokuyama, 1959 is reported from the Lower Jurassic Badaowan Formation at four localities, along the southern margin and western margin of the Junggar Basin. Taphonomic features recorded in the field indicate that it occurs in autochthonous or parautochthonous assemblages. The autecology of Waagenoperna therefore yields information on the palaeoenvironment of the area. The restriction of Waagenoperna to marine and brackish-water settings suggests that the sea water once reached these areas during the Sinemurian. This paper discusses the palaeogeographic implications and suggests an ingression of the sea water from the west to the western and southern part of the Junggar Basin. Additionally, the two Waagenoperna species collected from the Haojiagou section in the Junggar Basin are taxonomically documented.

  2. SURVIVAL ESTIMATES OF BYCATCH INDIVIDUALS DISCARDED FROM BIVALVE DREDGES

    Directory of Open Access Journals (Sweden)

    Francisco Leitão

    2014-12-01

    Full Text Available The fate of released bycatch is an issue of great interest for fisheries research and management. Survival experiments were carried out to assess the survival capacity of animals damaged and discarded during clam dredging operations. Three common bycatch species, two fish (Trachinus vipera; Dicologlossa cuneata and one crab (Polybius henslowii, were collected during the sorting of catches from a commercial dredging boat. An arbitrary score scale was used to quantify the type and extent of damage to the organisms. Onboard, damaged individuals were placed in tanks containing seawater which were subsequently transferred to the laboratory. Survival experiments were conducted during the subsequent 48h. D. cuneata exhibited the lowest mortality after 48h (54%, followed by P. henslowii (65% and T. vipera (81%. Despite the magnitude of the percentage mortalities determined, the average number of individuals estimated to die during a 15 minutes tow (standard commercial fishing time was relatively small: 1.2, 3.24 and 11 for D. cuneata, T. vipera and P. henslowii, respectively. Nevertheless, when these figures are extrapolated to cover all the dredging fleet the impact of this practice on the populations of the species studied can be significant, particulary for D. cuneata.

  3. 6-Bromohypaphorine from Marine Nudibranch Mollusk Hermissenda crassicornis is an Agonist of Human α7 Nicotinic Acetylcholine Receptor

    Directory of Open Access Journals (Sweden)

    Igor E. Kasheverov

    2015-03-01

    Full Text Available 6-Bromohypaphorine (6-BHP has been isolated from the marine sponges Pachymatisma johnstoni, Aplysina sp., and the tunicate Aplidium conicum, but data on its biological activity were not available. For the nudibranch mollusk Hermissenda crassicornis no endogenous compounds were known, and here we describe the isolation of 6-BHP from this mollusk and its effects on different nicotinic acetylcholine receptors (nAChR. Two-electrode voltage-clamp experiments on the chimeric α7 nAChR (built of chicken α7 ligand-binding and glycine receptor transmembrane domains or on rat α4β2 nAChR expressed in Xenopus oocytes revealed no action of 6-BHP. However, in radioligand analysis, 6-BHP competed with radioiodinated α-bungarotoxin for binding to human α7 nAChR expressed in GH4C1 cells (IC50 23 ± 1 μM, but showed no competition on muscle-type nAChR from Torpedo californica. In Ca2+-imaging experiments on the human α7 nAChR expressed in the Neuro2a cells, 6-BHP in the presence of PNU120596 behaved as an agonist (EC50 ~80 μM. To the best of our knowledge, 6-BHP is the first low-molecular weight compound from marine source which is an agonist of the nAChR subtype. This may have physiological importance because H. crassicornis, with its simple and tractable nervous system, is a convenient model system for studying the learning and memory processes.

  4. Quantification of "2"3"2Th, "2"3"4U, "2"3"5U and "2"3"8U in river mollusks by magnetic sector mass spectrometry with inductively coupled plasma source (Icp-SFMS)

    International Nuclear Information System (INIS)

    Arevalo R, D. L.; Hernandez M, H.; Romero G, E. T.; Lara A, N.; Alfaro de la T, M. C.

    2016-09-01

    The present work deals with the methodology established for the quantification of "2"3"2Th, "2"3"4U, "2"3"8U and "2"3"5U in the shell of gastropod mollusks collected in the rivers Valles, Coy and Axtla of San Luis Potosi, Mexico, which belong to the Panuco River basin; these rivers have as main source of pollution the discharge of municipal sewage, waste from small industries, agricultural and cattle residues and from natural sources. Conventional methods for measuring radio-nuclides are confronted with certain conditions related to the requirement in measurement, basically in the characterization that is related to the concepts of precision and accuracy. The analysis of the gastropod mollusk shell was performed by the Icp-SFMS technique; the main advantages of this technique lie in the isotope quantification capacity, the high precision and the low limits of detection, in this study are very important because these elements are in concentrations between ppb and ppt. This technique allowed the analysis of the samples having a complex matrix by the presence CaCO_3 minimizing the interferences thanks to the ionization efficiency of the Ar plasma. For the species Pachychilus monachus were found concentrations of "2"3"2Th of 0.16-5.37 μg/g and of total U of 0.101-4.081 μg/g being this species where the highest values of total U were found. For Thiara (melanoids) tuberculata the lowest values were found among the different species ("2"3"2Th 0.61-3.61 μg/g and total U 0.006-0.042 μg/g), for Pachychilus suturalis, values of "2"3"2Th of 0.58-6.4 μg/g and for Pachychilus sp. were found between 0.26-7.62 μg/g and for total U values between 0.28-3.33 μg/g. The method offers several advantages: speed, good precision, low values of quantification limits and high sensitivity in the measurement of radio-nuclides and heavy metals. (Author)

  5. Sodium provides unique insights into transgenerational effects of ocean acidification on bivalve shell formation.

    Science.gov (United States)

    Zhao, Liqiang; Schöne, Bernd R; Mertz-Kraus, Regina; Yang, Feng

    2017-01-15

    Ocean acidification is likely to have profound impacts on marine bivalves, especially on their early life stages. Therefore, it is imperative to know whether and to what extent bivalves will be able to acclimate or adapt to an acidifying ocean over multiple generations. Here, we show that reduced seawater pH projected for the end of this century (i.e., pH7.7) led to a significant decrease of shell production of newly settled juvenile Manila clams, Ruditapes philippinarum. However, juveniles from parents exposed to low pH grew significantly faster than those from parents grown at ambient pH, exhibiting a rapid transgenerational acclimation to an acidic environment. The sodium composition of the shells may shed new light on the mechanisms responsible for beneficial transgenerational acclimation. Irrespective of parental exposure, the amount of Na incorporated into shells increased with decreasing pH, implying active removal of excessive protons through the Na + /H + exchanger which is known to depend on the Na + gradient actively built up by the Na + /K + -ATPase as a driving force. However, the shells with a prior history of transgenerational exposure to low pH recorded significantly lower amounts of Na than those with no history of acidic exposure. It therefore seems very likely that the clams may implement less costly and more ATP-efficient ion regulatory mechanisms to maintain pH homeostasis in the calcifying fluid following transgenerational acclimation. Our results suggest that marine bivalves may have a greater capacity to acclimate or adapt to ocean acidification by the end of this century than currently understood. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Comparison of 230Th/234U Dating Results Obtained on Fossil Mollusk Shell from Morocco and Fossil Coral Samples from Egypt. Research of Methodological Criteria to Valid the Measured Age

    International Nuclear Information System (INIS)

    Choukri, A.; Hakam, O.K.; Reyss, J.L.

    2013-01-01

    Radiochemical ages of 126 unrecrystallized coral samples from the Egyptian shoreline and 125 fossil mollusk shell samples from the Atlantic coast of Moroccan High Atlas are discussed.For corals, the obtained ages are in good agreement with the ages reported previously on urecristallized corals except in some sites where some samples are affected by a cementation of younger aragonite.For mollusk shells, the obtained ages are in the most of cases, rejuvenated.This rejuvenation is due eventually to a post-incorporation of secondary uranium that is responsible of the wide dispersion of apparent ages of mollusk shells.

  7. Physiological effects of hypercapnia in the deep-sea bivalve Acesta excavata (Fabricius, 1779) (Bivalvia; Limidae)

    DEFF Research Database (Denmark)

    Hammer, Karen M.; Kristiansen, Erlend; Zachariassen, Karl Erik

    2011-01-01

    The option of storing CO(2) in subsea rock formations to mitigate future increases in atmospheric CO(2) may induce problems for animals in the deep sea. In the present study the deep-sea bivalve Acesta excavata was subjected to environmental hypercapnia (pHSW 6.35, P(CO2), =33,000 mu atm...... extracellular pH remained significantly lower during recovery. Intracellular non-bicarbonate buffering capacity of the posterior adductor muscle of hypercapnic animals was significantly lower than control values, but this was not the case for the remaining tissues analyzed. Oxygen consumption initially dropped...

  8. Trace element determination in soft tissues of marine bivalves by activation analysis

    International Nuclear Information System (INIS)

    Fukushima, M.; Tamate, H.; Nakano, Y.

    2003-01-01

    Trace elements in soft tissues of marine bivalves were determined by neutron activation analysis (NAA) and photon activation analysis (PAA). Elemental levels of Ag, As, Br, Co, Cu, Fe, I, Mn, Ni, Rb, Se, and Zn in the organs of giant ezoscallos, rock oysters, and giant crams were obtained. The metal-bound proteins were extracted from the mantles and hepatopancreases of rock oysters. By irradiating the fraction obtained by HPLC gel chromatography, the possibility for the existence of an Ag bound protein in the mantles was found. (author)

  9. Estimation of food limitation of bivalve larvae in coastal waters of north-western Europe

    DEFF Research Database (Denmark)

    Bos, O.G.; Hendriks, I.E.; Strasser, M.

    2006-01-01

    Marine invertebrate recruitment may be affected by food limitation during the pelagic larval life stages. In the present study, field data on abundance of bivalve larvae along with their prey (small phytoplankton) were examined to see whether they were consistent with predictions made...... assimilation rate averaged 7-26% of the maximum assimilation rate. Under the assumptions made for the present study, it is suggested that growth of larvae in north-west European waters is often food-limited. (c) 2005 Elsevier B.V. All rights reserved...

  10. Feeding current characteristics of three morphologically different bivalve suspension feeders, Crassostrea gigas, Mytilus edulis and Cerastoderma edule, in relation to food competition

    NARCIS (Netherlands)

    Troost, K.; Stamhuis, E.J.; van Duren, L.A; Wolff, W.J.

    Introduced Pacific oysters (Crassostrea gigas) have shown rapid expansion in the Oosterschelde estuary, while stocks of native bivalves declined slightly or remained stable. This indicates that they might have an advantage over native bivalve filter feeders. Hence, at the scale of individual

  11. Feeding current characteristics of three morphologically different bivalve suspension feeders, Crassostrea gigas Mytilus edulis and Cerastoderma edule , in relation to food competition

    NARCIS (Netherlands)

    Troost, K.; Stamhuis, E.J.; Duren, L.A.; Wolff, W.

    2009-01-01

    Introduced Pacific oysters (Crassostrea gigas) have shown rapid expansion in the Oosterschelde estuary, while stocks of native bivalves declined slightly or remained stable. This indicates that they might have an advantage over native bivalve filter feeders. Hence, at the scale of individual

  12. A statistical study of {sup 238}U and {sup 234}U/{sup 238}U distributions in coral samples from the Egyptian shoreline of the north-western Red sea and in fossil mollusk shells from the Atlantic coast of High Atlas in Morocco: implications for {sup 230}Th/{sup 234}U dating

    Energy Technology Data Exchange (ETDEWEB)

    Choukri, A.; Hakam, O.K. [Lab. des Faibles Radioactivites et d' Environnements, UFR: Faibles Radioactivites, Mathematiques physiques et environnement, Kenitra (Morocco); Reyss, J.L. [Lab. des Sciences de Climat et de l' Environnement, Domaine du CNRS, Gif sur Yvette (France); Plaziat, J.C. [Univ. de Paris-Sud, Dept. des Sciences de la Terre, Orsay (France)

    2002-07-01

    In this work, radiochemical analysis results of 126 uncrystallized coral samples from the Egyptian shoreline of northwestern Red Sea and 120 fossil mollusk shell samples from the Atlantic coast of Moroccan High Atlas at the North of Agadir City in Morocco are presented and discussed. The coral samples were collected in Egypt from the emerged coral reef terraces over 500 km from The Ras Gharib-Ras Shukeir depression (28 10') in the north to Wadi Lahami (north of Ras Banas, 24 10') in the south. The fossil mollusk shells were collected in Morocco from Agadir-Harbour in the south to Tamri village in the north extending over about 50 km. The statistical distributions of results ({sup 238}U content, {sup 234}U/{sup 238}U activity ratio and ages) obtained on the dated materials in the two different regions were compared for three fossil sea levels corresponding to three different climatic stages (Holocene, 5e, 7 and/or 9) in the aim to establish methodological criteria for judging validity of the measured ages. For corals, {sup 238}U content varies in narrow interval around the same average value of 3 ppm for the three sea levels, the calculated initial {sup 234}U/{sup 238}U values are in agreement with the actual sea water ratio (1.15) with some values slightly higher than for the older sea levels. The obtained ages are in good agreement with the ages reported previously for the three emerged fossil sea levels on unrecrystallized corals by alpha spectrometry and by mass spectrometry. For mollusk shells, except for Holocene sea level, {sup 238}U and initial {sup 234}U/{sup 238}U activity ratios vary for the older levels in wide intervals, independent of species and calcite contents of samples. The high {sup 238}U contents and {sup 234}U/{sup 238}U activity ratio are due eventually to a post-incorporation of secondary uranium from sea water or from continental waters drained away rivers. This incorporation leads to a rejuvenation of mollusk shell ages and is

  13. The complete genome of Teredinibacter turnerae T7901: an intracellular endosymbiont of marine wood-boring bivalves (shipworms.

    Directory of Open Access Journals (Sweden)

    Joyce C Yang

    Full Text Available Here we report the complete genome sequence of Teredinibacter turnerae T7901. T. turnerae is a marine gamma proteobacterium that occurs as an intracellular endosymbiont in the gills of wood-boring marine bivalves of the family Teredinidae (shipworms. This species is the sole cultivated member of an endosymbiotic consortium thought to provide the host with enzymes, including cellulases and nitrogenase, critical for digestion of wood and supplementation of the host's nitrogen-deficient diet. T. turnerae is closely related to the free-living marine polysaccharide degrading bacterium Saccharophagus degradans str. 2-40 and to as yet uncultivated endosymbionts with which it coexists in shipworm cells. Like S. degradans, the T. turnerae genome encodes a large number of enzymes predicted to be involved in complex polysaccharide degradation (>100. However, unlike S. degradans, which degrades a broad spectrum (>10 classes of complex plant, fungal and algal polysaccharides, T. turnerae primarily encodes enzymes associated with deconstruction of terrestrial woody plant material. Also unlike S. degradans and many other eubacteria, T. turnerae dedicates a large proportion of its genome to genes predicted to function in secondary metabolism. Despite its intracellular niche, the T. turnerae genome lacks many features associated with obligate intracellular existence (e.g. reduced genome size, reduced %G+C, loss of genes of core metabolism and displays evidence of adaptations common to free-living bacteria (e.g. defense against bacteriophage infection. These results suggest that T. turnerae is likely a facultative intracellular ensosymbiont whose niche presently includes, or recently included, free-living existence. As such, the T. turnerae genome provides insights into the range of genomic adaptations associated with intracellular endosymbiosis as well as enzymatic mechanisms relevant to the recycling of plant materials in marine environments and the production

  14. SNP detection from de novo transcriptome sequencing in the bivalve Macoma balthica: marker development for evolutionary studies.

    Directory of Open Access Journals (Sweden)

    Eric Pante

    Full Text Available Hybrid zones are noteworthy systems for the study of environmental adaptation to fast-changing environments, as they constitute reservoirs of polymorphism and are key to the maintenance of biodiversity. They can move in relation to climate fluctuations, as temperature can affect both selection and migration, or remain trapped by environmental and physical barriers. There is therefore a very strong incentive to study the dynamics of hybrid zones subjected to climate variations. The infaunal bivalve Macoma balthica emerges as a noteworthy model species, as divergent lineages hybridize, and its native NE Atlantic range is currently contracting to the North. To investigate the dynamics and functioning of hybrid zones in M. balthica, we developed new molecular markers by sequencing the collective transcriptome of 30 individuals. Ten individuals were pooled for each of the three populations sampled at the margins of two hybrid zones. A single 454 run generated 277 Mb from which 17K SNPs were detected. SNP density averaged 1 polymorphic site every 14 to 19 bases, for mitochondrial and nuclear loci, respectively. An [Formula: see text] scan detected high genetic divergence among several hundred SNPs, some of them involved in energetic metabolism, cellular respiration and physiological stress. The high population differentiation, recorded for nuclear-encoded ATP synthase and NADH dehydrogenase as well as most mitochondrial loci, suggests cytonuclear genetic incompatibilities. Results from this study will help pave the way to a high-resolution study of hybrid zone dynamics in M. balthica, and the relative importance of endogenous and exogenous barriers to gene flow in this system.

  15. Short-Term and Long-Term Biological Effects of Chronic Chemical Contamination on Natural Populations of a Marine Bivalve.

    Directory of Open Access Journals (Sweden)

    Marine Breitwieser

    Full Text Available Understanding the effects of chronic chemical contamination on natural populations of marine organisms is complex due to the combined effects of different types of pollutants and environmental parameters that can modulate the physiological responses to stress. Here, we present the effects of a chronic contamination in a marine bivalve by combining multiple approaches that provide information on individual and population health. We sampled variegated scallops (Mimachlamys varia at sites characterized by different contaminants and contamination levels to study the short and long-term (intergenerational responses of this species to physiological stress. We used biomarkers (SOD, MDA, GST, laccase, citrate synthase and phosphatases as indicators of oxidative stress, immune system alteration, mitochondrial respiration and general metabolism, and measured population genetic diversity at each site. In parallel, concentration of 14 trace metals and 45 organic contaminants (PAHs, PCBs, pesticides in tissues were measured. Scallops were collected outside and during their reproductive season to investigate temporal variability in contaminant and biomarker levels. Our analyses revealed that the levels of two biomarkers (Laccase-type phenoloxidase and malondialdehyde were significantly correlated with Cd concentration. Additionally, we observed significant seasonal differences for four of the five biomarkers, which is likely due to the scallop reproductive status at time of sampling. As a source of concern, a location that was identified as a reference site on the basis of inorganic contaminant levels presented the same level of some persistent organic pollutants (DDT and its metabolites than more impacted sites. Finally, potential long-term effects of heavy metal contamination were observed for variegated scallops as genetic diversity was depressed in the most polluted sites.

  16. The control of an invasive bivalve, Corbicula fluminea, using gas impermeable benthic barriers in a large natural lake.

    Science.gov (United States)

    Wittmann, Marion E; Chandra, Sudeep; Reuter, John E; Schladow, S Geoffrey; Allen, Brant C; Webb, Katie J

    2012-06-01

    Anoxia can restrict species establishment in aquatic systems and the artificial promotion of these conditions can provide an effective control strategy for invasive molluscs. Low abundances (2-20 m(-2)) of the nonnative bivalve, Asian clam (Corbicula fluminea), were first recorded in Lake Tahoe, CA-NV in 2002 and by 2010 nuisance-level population densities (>10,000 m(-2)) were observed. A non-chemical control method using gas impermeable benthic barriers to reduce dissolved oxygen (DO) concentrations available to C. fluminea was tested in this ultra-oligotrophic natural lake. In 2009, the impact of ethylene propylene diene monomer (EPDM) sheets (9 m(2), n = 6) on C. fluminea beds was tested on 1-7 day intervals over a 56 day period (August-September). At an average water temperature of 18 °C, DO concentrations under these small barriers were reduced to zero after 72 h resulting in 100 % C. fluminea mortality after 28 days. In 2010, a large EPDM barrier (1,950 m(2)) was applied to C. fluminea populations for 120 days (July-November). C. fluminea abundances were reduced over 98 % after barrier removal, and remained significantly reduced (>90 %) 1 year later. Non-target benthic macroinvertebrate abundances were also reduced, with variable taxon-specific recolonization rates. High C. fluminea abundance under anoxic conditions increased the release of ammonium and soluble reactive phosphorus from the sediment substrate; but levels of unionized ammonia were low at 0.004-0.005 mg L(-1). Prolonged exposure to anoxia using benthic barriers can provide an effective short term control strategy for C. fluminea.

  17. Short-Term and Long-Term Biological Effects of Chronic Chemical Contamination on Natural Populations of a Marine Bivalve.

    Science.gov (United States)

    Breitwieser, Marine; Viricel, Amélia; Graber, Marianne; Murillo, Laurence; Becquet, Vanessa; Churlaud, Carine; Fruitier-Arnaudin, Ingrid; Huet, Valérie; Lacroix, Camille; Pante, Eric; Le Floch, Stéphane; Thomas-Guyon, Hélène

    2016-01-01

    Understanding the effects of chronic chemical contamination on natural populations of marine organisms is complex due to the combined effects of different types of pollutants and environmental parameters that can modulate the physiological responses to stress. Here, we present the effects of a chronic contamination in a marine bivalve by combining multiple approaches that provide information on individual and population health. We sampled variegated scallops (Mimachlamys varia) at sites characterized by different contaminants and contamination levels to study the short and long-term (intergenerational) responses of this species to physiological stress. We used biomarkers (SOD, MDA, GST, laccase, citrate synthase and phosphatases) as indicators of oxidative stress, immune system alteration, mitochondrial respiration and general metabolism, and measured population genetic diversity at each site. In parallel, concentration of 14 trace metals and 45 organic contaminants (PAHs, PCBs, pesticides) in tissues were measured. Scallops were collected outside and during their reproductive season to investigate temporal variability in contaminant and biomarker levels. Our analyses revealed that the levels of two biomarkers (Laccase-type phenoloxidase and malondialdehyde) were significantly correlated with Cd concentration. Additionally, we observed significant seasonal differences for four of the five biomarkers, which is likely due to the scallop reproductive status at time of sampling. As a source of concern, a location that was identified as a reference site on the basis of inorganic contaminant levels presented the same level of some persistent organic pollutants (DDT and its metabolites) than more impacted sites. Finally, potential long-term effects of heavy metal contamination were observed for variegated scallops as genetic diversity was depressed in the most polluted sites.

  18. Seasonal variability in somatic and reproductive investment of the bivalve Scrobicularia plana (da Costa, 1778) along a latitudinal gradient

    Science.gov (United States)

    Santos, Sílvia; Cardoso, Joana F. M. F.; Carvalho, Célia; Luttikhuizen, Pieternella C.; van der Veer, Henk W.

    2011-03-01

    Monthly investment in soma and gonads in the bivalve Scrobicularia plana is described for three populations along its distributional range: Minho estuary, Portugal; Westerschelde estuary, The Netherlands and Buvika estuary, Norway. Seasonal cycles in body mass (BMI), somatic mass (SMI) and gonadal mass (GMI) indices were observed for all populations. In Portugal, BMI and SMI peaked in mid-autumn, while in The Netherlands both indices were at their highest in mid-spring. Norway showed a different pattern with two distinct peaks: one in mid-autumn and a second peak in spring. GMI reached maximum values in July in Portugal and Netherlands and in June in Norway. Overall, mean BMI and SMI were lower in Portugal while mean GMI was lower in Norway. The spawning period lasted the whole summer in Portugal, but was shorter (only two months) in The Netherlands and Norway. The reproductive investment in The Netherlands was significantly higher than in Portugal and Norway, with the lowest values being observed in Norway. Differences in annual cycles between populations were attributed to environmental factors, namely temperature and food availability. Temperature seems important in shaping the reproductive pattern with more northern populations showing shorter reproductive periods starting later in the year, and a lower reproductive output. In addition, winter water temperatures can explain the lower mean body and somatic mass values observed in Portugal. Food availability influenced the physiological performance of the species with peaks in somatic mass coinciding with phytoplankton blooms. This relation between physiological performance and environmental factors influences S. plana distribution, densities and even survival, with natural consequences on its commercial importance.

  19. Field clearance of an intertidal bivalve bed: relative significance of the co-occurring blue mussel Mytilus edulis and Pacific oyster Crassostrea gigas

    DEFF Research Database (Denmark)

    Vismann, Bent; Holm, Mark Wejlemann; Davids, Jens

    2016-01-01

    was estimated by combining field measurements of clearance rates and modelling of the bivalve bed (topography, biomass distribution, temporal and spatial water coverage and depth). The average density of C. gigas and M. edulis was 35 ± 36 and 1001 ± 685 ind. m−2, respectively. The water volume cleared during...... a tidal cycle was estimated at 45 838 m3, of which C. gigas and M. edulis contributed 9169 and 36 669 m3, respectively. Therefore, M. edulis contributed 4 times as much as C. gigas to the bivalve bed’s clearance, and the 2 bivalves were estimated to clear the water volume 1.9 times during each tidal cycle....... However, the estimated water column cleared during low tide is overestimated due to phytoplankton depletion. Hence, it is concluded that the bivalve bed clears the water close to 1 time each tidal cycle. This, together with a low dry weight of soft parts, indicates that the bivalve bed, in general...

  20. 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

  1. Guidance documents: Continued support to improve operations of fish hatcheries and field sites to reduce the impact or prevent establishment of New Zealand Mudsnails and other invasive mollusks

    Science.gov (United States)

    Moffitt, Christine M.

    2017-01-01

    This project tested and revised a risk assessment/management tool authored by Moffitt and Stockton designed to provide hatchery biologists and others a structure to measure risk and provide tools to control, prevent or eliminate invasive New Zealand mudsnails (NZMS) and other invasive mollusks in fish hatcheries and hatchery operations. The document has two parts: the risk assessment tool, and an appendix that summarizes options for control or management.The framework of the guidance document for risk assessment/hatchery tool combines approaches used by the Hazard Analysis and Critical Control Points (HACCP) process with those developed by the Commission for Environmental Cooperation (CEC), of Canada, Mexico, and the United States, in the Tri-National Risk Assessment Guidelines for Aquatic Alien Invasive Species. The framework approach for this attached first document assesses risk potential with two activities: probability of infestation and consequences of infestation. Each activity is treated equally to determine the risk potential. These two activities are divided into seven basic elements that utilize scientific, technical, and other relevant information in the process of the risk assessment. To determine the probability of infestation four steps are used that have scores reported or determined and averaged. This assessment follows a familiar HACCP process to assess pathways of entry, entry potential, colonization potential, spread potential. The economic, environmental and social consequences are considered as economic impact, environmental impact, and social and cultural influences.To test this document, the Principal Investigator worked to identify interested hatchery managers through contacts at regional aquaculture meetings, fish health meetings, and through the network of invasive species managers and scientists participating in the Western Regional Panel on Aquatic Nuisance Species and the 100th Meridian Initiative's Columbia River Basin Team, and the

  2. Teredo navalis in the Baltic Sea: Larval Dynamics of an Invasive Wood-Boring Bivalve at the Edge of Its Distribution

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    Heike Lippert

    2017-10-01

    Full Text Available Wooden groin systems on the southwestern Baltic Sea coast are a traditional and important coastal-protection facility, but have been regularly infested and destroyed by the wood-boring bivalve Teredo navalis since the early 1990s. The occurrence of T. navalis was presumed to be limited mainly by the prevailing low salinities. Recently, a possible range expansion of this invasive species to the more eastern parts of the Baltic Sea has been discussed. T. navalis larval settlement was therefore monitored at the distribution boundary of the species in the Baltic Sea over a period of 4 years. At 7 stations along the prevailing salinity gradient on the Mecklenburg-western Pomeranian coast, larval traps were installed at regular time intervals, while at the same time water temperature and salinity were measured continuously every hour. Correlations between measured abiotic parameters and borehole abundance of T. navalis were tested. For the German Baltic Sea coast, no range expansion of T. navalis was confirmed. The salinity and temperatures at the groin systems varied among the study years, and significant correlations between T. navalis borehole abundance and salinity as well as temperature were found. Higher summer temperatures favor the T. navalis borehole abundance on the Mecklenburg-western Pomeranian coast, and may slightly shift the distribution border of this species toward lower salinities.

  3. The invasion of five alien species in the Delta do Parnaíba Environmental Protection Area, Northeastern Brazil

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    Daniel Loebmann

    2010-09-01

    Full Text Available Marine biological invasions have been regarded as one of the major causes of native biodiversity loss, with shipping and aquaculture being the leading contributors for the introductions of alien species in aquatic ecosystems. In the present study, five aquatic alien species (one mollusk, three crustaceans and one fish species were detected during dives, shore searches and from the fisheries on the coast of the Delta do Parnaíba Environmental Protection Area, in the States of Piauí and Maranhão, Northeastern Brazil. The species were the bicolor purse-oyster Isognomon bicolor, the whiteleg shrimp Litopenaeus vannamei, the giant river prawn Macrobrachium rosenbergii, the Indo-Pacific swimming crab Charybdis hellerii and, the muzzled blenny Omobranchus punctatus. Ballast water (I. bicolor, C. hellerii, and O. punctatus and aquaculture activities (L. vannamei and M. rosenbergii in adjacent areas are the most likely vectors of introduction. All exotic species found have potential impact risks to the environment because they are able to compete against native species for resources (food and habitat. Isognomon bicolor share the same habitat and food items with the native bivalve species of mussels and barnacles. Litopenaeus vannamei share the same habitat and food items with the native penaeids such as the pinkspot shrimp Farfantepenaeus brasiliensis, the Southern brown shrimp Farfantepenaeus subtilis, and the Southern white shrimp Litopenaeus schmitti, and in the past few years L. vannamei was responsible for a viral epidemics in the cultivation tanks that could be transmitted to native penaeid shrimps. Charybdis hellerii is also able to cause impacts on the local fisheries as the species can decrease the populations of native portunid crabs which are commercialized in the studied region. Macrobrachium rosenbergii may be sharing natural resources with the Amazon River prawn Macrobrachium amazonicum. Omobranchus punctatus shares habit with the native

  4. Los moluscos de la ofrenda 107 del Templo Mayor de Tenochtitlan The mollusks of the offering 107 of the Great Temple of Tenochtitlan

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    Norma Valentín-Maldonado

    2007-10-01

    Full Text Available El propósito de este trabajo es dar a conocer la identificación biológica de las especies de moluscos encontradas en la ofrenda 107, que fue depositada en la séptima etapa constructiva del Templo Mayor de Tenochtitlan (1502-1521. La identificación se realizó por medio de la bibliografía especializada, y en el caso de algunos ejemplares por comparación directa con los de la colección malacológica de referencia del Laboratorio M. en C. Ticul Álvarez Solórzano. Se identificaron 246 ejemplares de moluscos marinos; 191 pertenecen a la clase Gastropoda (78% y 55 a la Bivalvia (22%. El número más frecuente de especies proviene de la provincia caribeña, siendo su hábitat principal las playas arenosas y las costas rocosas. Los desgastes y fracturas observadas en la mayoría de los esqueletos calcáreos de animales ya muertos, indican que fueron recolectados en las playas; por otro lado, el buen estado de preservación de algunos de ellos sugiere que se capturaron vivos, y en ciertos casos mediante buceo. A través de este estudio ha sido posible obtener datos, como la procedencia, el hábitat, la coloración natural y la selectividad de las diferentes especies identificadas, los cuales contribuyen al conocimiento de aspectos económicos e ideológicos de la cultura mexica.The purpose of this work is to report the identifications of the species of mollusks found in offering 107, which was buried in the seventh stage of the construction of the Great Temple of Tenochtitlan (1502-1521. This was done by direct comparison with specimens in the malacological reference collection of the Ticul Álvarez Solorzano Laboratory and the literature. The 246 marine individuals belonging to two classes were identified; 191 belonging to the Gastropoda (78% and 55 to the Bivalvia (22%. The largest number of species came from the Caribbean Province, with species from sandy beaches and rocky coasts being most common. The abrasions and fractures observed in

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

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    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.

  6. Uniform Variation in Genetic-Traits of a Marine Bivalve Related to Starvation, Pollution and Geographic Clines

    NARCIS (Netherlands)

    Hummel, H.; Bogaards, R.H.; Amiard-Triquet, C.; Bachelet, G.; Desprez, M.; Marchand, J.; Rybarczyk, H.; Sylvand, B.; De Wit, Y.; De Wolf, L.

    1995-01-01

    Consistent patterns of genetic variation in the marine bivalve Macoma balthica (L.) were found after exposure to low levels of copper, starvation, and along geographic dines. The geographic dines were related to temperature and salinity. Genetic differences were primarily found in the LAP (Leucine

  7. The potential accumulation of polycyclic aromatic hydrocarbons in phytoplankton and bivalves in Can Gio coastal wetland, Vietnam.

    Science.gov (United States)

    Thuy, Hoang Thi Thanh; Loan, Tu Thi Cam; Phuong, Trinh Hong

    2018-05-12

    Polycyclic aromatic hydrocarbons (PAHs) are one of the most important classes of anthropogenic persistent organic contaminants in the marine environment. This review discusses a whole range of findings that address various aspects of the bioaccumulation of PAHs in two common marine biota (phytoplankton and bivalves) globally and especially for Can Gio coastal wetland, Vietnam. The published information and collected data on the bioconcentration and accumulation mechanisms of PAHs as well as implications for Can Gio coastal wetland are compiled for phytoplankton and bivalves. PAHs are still released to Can Gio coastal environments from various sources and then transported to coastal environments through various physical processes; they may enter marine food chains and be highly accumulated in phytoplankton and bivalves. Thus, PAHs' bioaccumulation should be considered as one important criterion to assess the water's quality, directly linked to human health due to seafood consumption. Ecologically, Can Gio coastal wetland plays an important role to the South Vietnam key economic zone. However, it is also an area of potential PAHs inputs. With the abundant phytoplankton and bivalves in Can Gio coastal wetland, the PAHs bioaccumulation in these biota is inevitably detected. Thus, further study on the bioavailability of these contaminants is urgently needed in order to mitigate their negative effects and protect the ecosystems.

  8. Evaluation of the feeding preference between the aquatic macrophytes Egeria densa and Chara indica by the invasive mollusk Melanoides tuberculata.

    Science.gov (United States)

    Medeiros, E L; Henry-Silva, G G

    2017-01-01

    This study evaluated the feeding preference of the invasive mollusk Melaniudes tuberculata between the aquatic macrophytes Egeria densa and Chara indica. The experiment consisted of twelve experimental units (glass aquariums) each of which contained three liters of water and three compartments. Fragments of E. densa and C. indica were placed in separate compartments within each unit; the third compartment, which did not contain macrophytes, was used as the control. Twenty Melanoides tuberculata individuals were placed in each unit and monitored hourly over the course of 24 hours for preferential movements. Physical and chemical water variables were measured at the beginning and end of the experiment. Habitat complexity was determined through collected macrophyte fragments and determined using the Fractop program. After 24 hours, the highest average number of individuals was observed in the treatment with Chara indica (ten individuals), which differed significantly from the treatment with E. densa (four individuals) and the control treatment (two individuals). The number of individuals between the E. densa and control treatment were similar. M. tuberculata showed a clear feeding preference for C. indica.

  9. From Mollusks to Medicine: A Venomics Approach for the Discovery and Characterization of Therapeutics from Terebridae Peptide Toxins

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    Aida Verdes

    2016-04-01

    Full Text Available Animal venoms comprise a diversity of peptide toxins that manipulate molecular targets such as ion channels and receptors, making venom peptides attractive candidates for the development of therapeutics to benefit human health. However, identifying bioactive venom peptides remains a significant challenge. In this review we describe our particular venomics strategy for the discovery, characterization, and optimization of Terebridae venom peptides, teretoxins. Our strategy reflects the scientific path from mollusks to medicine in an integrative sequential approach with the following steps: (1 delimitation of venomous Terebridae lineages through taxonomic and phylogenetic analyses; (2 identification and classification of putative teretoxins through omics methodologies, including genomics, transcriptomics, and proteomics; (3 chemical and recombinant synthesis of promising peptide toxins; (4 structural characterization through experimental and computational methods; (5 determination of teretoxin bioactivity and molecular function through biological assays and computational modeling; (6 optimization of peptide toxin affinity and selectivity to molecular target; and (7 development of strategies for effective delivery of venom peptide therapeutics. While our research focuses on terebrids, the venomics approach outlined here can be applied to the discovery and characterization of peptide toxins from any venomous taxa.

  10. Taxonomic revision of the fossil pulmonate mollusks of Itaboraí Basin (Paleocene, Brazil

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    Rodrigo Brincalepe Salvador

    2013-01-01

    Full Text Available The limestones of Itaboraí Basin (Middle Paleocene, Rio de Janeiro, Brazil, harbor a rich fossil molluscan fauna consisting exclusively of pulmonate snails, both terrestrial and freshwater. An extensive taxonomic revision of this paleofauna is conducted here. A new genus, Cortana, is described as well as two new species, Eoborus fusiforme and Gastrocopta itaboraiensis. The revised classification is as follows: Austrodiscus lopesi (Charopidae; Biomphalaria itaboraiensis (Planorbidae; "Brachypodella" britoi (Urocoptidae; Brasilennea arethusae, Brasilennea guttula, Brasilennea minor (Cerionidae; Bulimulus fazendicus, Bulimulus trindadeae, Cortana carvalhoi, Cyclodontina coelhoi, Itaborahia lamegoi, Leiostracus ferreirai, Plagiodontes aff. dentatus (Orthalicidae; Cecilioides sommeri (Ferussaciidae; Eoborus rotundus, Eoborus sanctijosephi, Eoborus fusiforme (Strophocheilidae; Gastrocopta mezzalirai, Gastrocopta itaboraiensis (Gastrocoptidae; Temesa magalhaesi (Clausiliidae. The species Strobilopsis mauryae was considered a synonym of Brasilennea arethusae; Bulimulus sommeri a synonym of Itaborahia lamegoi; and Vorticifex fluminensis a synonym of Eoborus sanctijosephi. Itaboraí Basin has the most ancient records of the families Orthalicidae, Gastrocoptidae, Ferussaciidae and Strophocheilidae. Moreover, the basin's records of Charopidae, Clausiliidae, Cerionidae, and Urocoptidae are among the most ancient in the world and, among these, those of Cerionidae, Clausiliidae and Urocoptidae deserve special attention since they are greatly removed from these families' current distribution. Additionally, Itaboraí has the most ancient records for the genera Austrodiscus, Brachypodella, Bulimulus, Cecilioides, Cyclodontina, Eoborus, Gastrocopta, Leiostracus, Plagiodontes and Temesa. There are three endemic genera in the basin: Brasilennea, Cortana and Itaborahia. Further discussion on paleobiogeography and evolution of this paleofauna is also provided.

  11. Size Polymorphism in Alleles of the Myoglobin Gene from Biomphalaria Mollusks

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    Marcelo M. Santoro

    2010-10-01

    Full Text Available Introns are common among all eukaryotes, while only a limited number of introns are found in prokaryotes. Globin and globin-like proteins are widely distributed in nature, being found even in prokaryotes and a wide range of patterns of intron-exon have been reported in several eukaryotic globin genes. Globin genes in invertebrates show considerable variation in the positions of introns; globins can be found without introns, with only one intron or with three introns in different positions. In this work we analyzed the introns in the myoglobin gene from Biomphalaria glabrata, B. straminea and B. tenagophila. In the Biomphalaria genus, the myoglobin gene has three introns; these were amplified by PCR and analyzed by PCR-RFLP. Results showed that the size (number or nucleotides and the nucleotide sequence of the coding gene of the myoglobin are variable in the three species. We observed the presence of size polymorphisms in intron 2 and 3; this characterizes a homozygous/heterozygous profile and it indicates the existence of two alleles which are different in size in each species of Biomphalaria. This polymorphism could be explored for specific identification of Biomphalaria individuals.

  12. Using transplanted bivalves to assess oil exposure and effects in Delaware Bay

    International Nuclear Information System (INIS)

    Salazar, M.; Salazar, S.; Mearns, A.; Venosa, A.; Eberhart, B.

    1995-01-01

    To evaluate the effectiveness of bioremediation, the US EPA oiled intertidal plots in Delaware Bay and monitored oil degradation rates. This controlled release of oil was also used to test the utility of transplanted bivalves in assessing oil spills and to evaluate the extent and potential effects of the release. Measuring the accumulation of oil in bivalve tissues was used to estimate exposure and the extent of contamination. Growth was used to estimate potential bioeffects. Approximately 1,800 mussels and 1,200 oysters were transplanted to 11 intertidal sites. Five treatment sites were within 1 meter of the lower end of the oiled plots. A total of six sites were used as controls, three on either side of the oiled plots at 5, 10, and 100 m. Samples were taken on Day 0, 2, 15, and 28 to estimate the rate of bioaccumulation. All of the mussels died within the first week of exposure; oysters exhibited over 95% survival but growth was minimal. The authors found a statistically significant difference in tissue weights when comparing treatment sites with control sites. The total concentration of polynuclear aromatic hydrocarbons (PAHs) in tissues of oysters nearest the oiled plots increased by a factor of four after an exposure period of two days. PAH concentrations in control oysters nearest the mouth of the bay increased slightly but the differences were not statistically significant. The control oysters nearest the head of the bay received an intermediate dose which was depurated by the end of the 28-day experiment. PAHs in the oysters nearest the oiled plots approached but did not return to background levels by the end of the test

  13. Hepatitis A and E Viruses in Wastewaters, in River Waters, and in Bivalve Molluscs in Italy.

    Science.gov (United States)

    Iaconelli, M; Purpari, G; Della Libera, S; Petricca, S; Guercio, A; Ciccaglione, A R; Bruni, R; Taffon, S; Equestre, M; Fratini, M; Muscillo, M; La Rosa, Giuseppina

    2015-12-01

    Several studies have reported the detection of hepatitis A (HAV) and E (HEV) virus in sewage waters, indicating a possibility of contamination of aquatic environments. The objective of the present study was to assess the occurrence of HAV and HEV in different water environments, following the route of contamination from raw sewage through treated effluent to the surface waters receiving wastewater discharges . Bivalve molluscan shellfish samples were also analyzed, as sentinel of marine pollution. Samples were tested by RT-PCR nested type in the VP1/2A junction for HAV, and in the ORF1 and ORF2 regions for HEV. Hepatitis A RNA was detected in 12 water samples: 7/21 (33.3%) raw sewage samples, 3/21 (14.3%) treated sewage samples, and 2/27 (7.4%) river water samples. Five sequences were classified as genotype IA, while the remaining 7 sequences belonged to genotype IB. In bivalves, HAV was detected in 13/56 samples (23.2%), 12 genotype IB and one genotype IA. Whether the presence of HAV in the matrices tested indicates the potential for waterborne and foodborne transmission is unknown, since infectivity of the virus was not demonstrated. HEV was detected in one raw sewage sample and in one river sample, both belonging to genotype 3. Sequences were similar to sequences detected previously in Italy in patients with autochthonous HEV (no travel history) and in animals (swine). To our knowledge, this is the first detection of HEV in river waters in Italy, suggesting that surface water can be a potential source for exposure .

  14. Impact of seawater carbonate chemistry on the calcification of marine bivalves

    Science.gov (United States)

    Thomsen, J.; Haynert, K.; Wegner, K. M.; Melzner, F.

    2015-07-01

    Bivalve calcification, particularly of the early larval stages, is highly sensitive to the change in ocean carbonate chemistry resulting from atmospheric CO2 uptake. Earlier studies suggested that declining seawater [CO32-] and thereby lowered carbonate saturation affect shell production. However, disturbances of physiological processes such as acid-base regulation by adverse seawater pCO2 and pH can affect calcification in a secondary fashion. In order to determine the exact carbonate system component by which growth and calcification are affected it is necessary to utilize more complex carbonate chemistry manipulations. As single factors, pCO2 had no effects and [HCO3-] and pH had only limited effects on shell growth, while lowered [CO32-] strongly impacted calcification. Dissolved inorganic carbon (CT) limiting conditions led to strong reductions in calcification, despite high [CO32-], indicating that [HCO3-] rather than [CO32-] is the inorganic carbon source utilized for calcification by mytilid mussels. However, as the ratio [HCO3-] / [H+] is linearly correlated with [CO32-] it is not possible to differentiate between these under natural seawater conditions. An equivalent of about 80 μmol kg-1 [CO32-] is required to saturate inorganic carbon supply for calcification in bivalves. Below this threshold biomineralization rates rapidly decline. A comparison of literature data available for larvae and juvenile mussels and oysters originating from habitats differing substantially with respect to prevailing carbonate chemistry conditions revealed similar response curves. This suggests that the mechanisms which determine sensitivity of calcification in this group are highly conserved. The higher sensitivity of larval calcification seems to primarily result from the much higher relative calcification rates in early life stages. In order to reveal and understand the mechanisms that limit or facilitate adaptation to future ocean acidification, it is necessary to better

  15. HMGB in mollusk Crassostrea ariakensis Gould: structure, pro-inflammatory cytokine function characterization and anti-infection role of its antibody.

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    Ting Xu

    Full Text Available BACKGROUND: Crassostrea ariakensis Gould is a representative bivalve species and an economically important oyster in China, but suffers severe mortalities in recent years that are caused by rickettsia-like organism (RLO. Prevention and control of this disease is a priority for the development of oyster aquaculture. It has been proven that mammalian HMGB (high mobility group box can be released extracellularly and acts as an important pro-inflammatory cytokine and late mediator of inflammatory reactions. In vertebrates, HMGB's antibody (anti-HMGB has been shown to confer significant protection against certain local and systemic inflammatory diseases. Therefore, we investigated the functions of Ca-HMGB (oyster HMGB and anti-CaHMGB (Ca-HMGB's antibody in oyster RLO/LPS (RLO or LPS-induced disease or inflammation. METHODOLOGY/PRINCIPAL FINDINGS: Sequencing analysis revealed Ca-HMGB shares conserved structures with mammalians. Tissue-specific expression indicates that Ca-HMGB has higher relative expression in hemocytes. Significant continuous up-regulation of Ca-HMGB was detected when the hemocytes were stimulated with RLO/LPS. Recombinant Ca-HMGB protein significantly up-regulated the expression levels of some cytokines. Indirect immunofluorescence study revealed that Ca-HMGB localized both in the hemocyte nucleus and cytoplasm before RLO challenge, but mainly in the cytoplasm 12 h after challenge. Western blot analysis demonstrated Ca-HMGB was released extracellularly 4-12 h after RLO challenge. Anti-CaHMGB was added to the RLO/LPS-challenged hemocyte monolayer and real-time RT-PCR showed that administration of anti-CaHMGB dramatically reduced the rate of RLO/LPS-induced up-regulation of LITAF at 4-12 h after treatment. Flow cytometry analysis indicated that administration of anti-CaHMGB reduced RLO/LPS-induced hemocyte apoptosis and necrosis rates. CONCLUSIONS/SIGNIFICANCE: Ca-HMGB can be released extracellularly and its subcellular localization

  16. 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

  17. 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.

  18. Between Land and Sea: Mangroves and Mollusks along Brazil’s Mangal Coast

    Directory of Open Access Journals (Sweden)

    Judith A. Carney

    2016-12-01

    Full Text Available Westerners have long viewed mangroves as forbidding, pestilential landscapes. While modern medicine transformed their deadly reputation, the perception lingered of an environment that was little more than a tropical wasteland. The 1992 Earth Summit in Rio de Janeiro profoundly changed this view by drawing attention to the ecosystem as a habitat crucial to the life cycles of many species and endangered fauna yet increasingly at risk from deforestation. Conservation initiatives in the years since the Rio Summit, however, seldom recognize mangroves as a habitat that has also long supported human life. This is evident in the shell middens found along mangrove coasts and in the historical record of shellfish harvested for dietary protein. With a focus on Brazil, this article examines the shellfish that sustained Amerindians, enslaved Africans, and their descendants along the mangal coast since pre-Columbian times. The discussion contends that Brazil’s mangrove forests cannot be separated from the history of the tropical peoples who have successively lived in and managed this ecosystem from ancient times to the present. Finally, the article concludes that a research focus on shellfish suggests broader linkages to South Atlantic history.

  19. Interpopulational variability of molecular responses to ionizing radiation in freshwater bivalves Anodonta anatina (Unionidae)

    Energy Technology Data Exchange (ETDEWEB)

    Falfushynska, H. [Research Laboratory of Comparative Biochemistry and Molecular Biology, Ternopil National Pedagogical University, 2, Kryvonosa Str, Ternopil 46027 (Ukraine); Department of Biological Sciences, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Department of General Chemistry, I.Ya. Horbachevsky Ternopil State Medical University, 1, Maidan Voli, Ternopil 46001 (Ukraine); Gnatyshyna, L. [Research Laboratory of Comparative Biochemistry and Molecular Biology, Ternopil National Pedagogical University, 2, Kryvonosa Str, Ternopil 46027 (Ukraine); Department of General Chemistry, I.Ya. Horbachevsky Ternopil State Medical University, 1, Maidan Voli, Ternopil 46001 (Ukraine); Yurchak, I.; Stoliar, O. [Research Laboratory of Comparative Biochemistry and Molecular Biology, Ternopil National Pedagogical University, 2, Kryvonosa Str, Ternopil 46027 (Ukraine); Sokolova, I.M., E-mail: isokolova@uncc.edu [Department of Biological Sciences, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)

    2016-10-15

    Freshwater ecosystems are exposed to multiple anthropogenic stressors including chemical pollution and warming that can affect health of the resident organisms and their responses to novel challenges. We investigated the of in situ exposure history on molecular responses to a novel stressor, ionizing radiation, in unionid mollusks Anodonta anatina. Males from pristine (F-), agricultural (A-) sites and a cooling reservoir of a nuclear power plant (N-site) were exposed to acute low dose (2 mGy) X-ray radiation followed by 14 days of recovery (R-groups) or to control conditions (C-groups). Biomarkers of oxidative stress, geno-, cyto- and neurotoxicity were used to assess cellular injury and stress. Control group from the cooling reservoir (CN) had higher background levels of caspase-3 activity, metallothionein concentrations and nuclear lesions and lower levels of superoxide dismutase (SOD) and glutathione in the gills compared to other control groups (CF and CA). Irradiation induced cellular damage in mussels from all three sites including increased levels of nuclear lesions in hemocytes, depletion of caspase-3, suppression of superoxide dismutase and catalase activities, an increase of the lipid peroxidation and oxidized glutathione levels, as well as down-regulation of cholinesterase indicating neurotoxicity. The up-regulation of ethoxyresorufin-O-deethylase activity in the digestive gland and vitellogenin-like protein level in gonads were also found in radiation-exposed groups indicating feminization of males and disturbances of xenobiotic metabolism. The RA-group showed the greatest magnitude of radiation-induced stress responses compared to the other two groups. Overall, unionid mollusks, particularly those from a chronically polluted agricultural site, were highly sensitive to low-dose radiation (2 mGy) indicating limitations of stress protection mechanisms to deal with multiple stressors. - Highlights: • Habitat-specific effects of irradiation were studied

  20. Interpopulational variability of molecular responses to ionizing radiation in freshwater bivalves Anodonta anatina (Unionidae)

    International Nuclear Information System (INIS)

    Falfushynska, H.; Gnatyshyna, L.; Yurchak, I.; Stoliar, O.; Sokolova, I.M.

    2016-01-01

    Freshwater ecosystems are exposed to multiple anthropogenic stressors including chemical pollution and warming that can affect health of the resident organisms and their responses to novel challenges. We investigated the of in situ exposure history on molecular responses to a novel stressor, ionizing radiation, in unionid mollusks Anodonta anatina. Males from pristine (F-), agricultural (A-) sites and a cooling reservoir of a nuclear power plant (N-site) were exposed to acute low dose (2 mGy) X-ray radiation followed by 14 days of recovery (R-groups) or to control conditions (C-groups). Biomarkers of oxidative stress, geno-, cyto- and neurotoxicity were used to assess cellular injury and stress. Control group from the cooling reservoir (CN) had higher background levels of caspase-3 activity, metallothionein concentrations and nuclear lesions and lower levels of superoxide dismutase (SOD) and glutathione in the gills compared to other control groups (CF and CA). Irradiation induced cellular damage in mussels from all three sites including increased levels of nuclear lesions in hemocytes, depletion of caspase-3, suppression of superoxide dismutase and catalase activities, an increase of the lipid peroxidation and oxidized glutathione levels, as well as down-regulation of cholinesterase indicating neurotoxicity. The up-regulation of ethoxyresorufin-O-deethylase activity in the digestive gland and vitellogenin-like protein level in gonads were also found in radiation-exposed groups indicating feminization of males and disturbances of xenobiotic metabolism. The RA-group showed the greatest magnitude of radiation-induced stress responses compared to the other two groups. Overall, unionid mollusks, particularly those from a chronically polluted agricultural site, were highly sensitive to low-dose radiation (2 mGy) indicating limitations of stress protection mechanisms to deal with multiple stressors. - Highlights: • Habitat-specific effects of irradiation were studied

  1. Taxonomic revision of the fossil pulmonate mollusks of Itaboraí Basin (Paleocene, Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Brincalepe Salvador

    2013-01-01

    Full Text Available The limestones of Itaboraí Basin (Middle Paleocene, Rio de Janeiro, Brazil, harbor a rich fossil molluscan fauna consisting exclusively of pulmonate snails, both terrestrial and freshwater. An extensive taxonomic revision of this paleofauna is conducted here. A new genus, Cortana, is described as well as two new species, Eoborus fusiforme and Gastrocopta itaboraiensis. The revised classification is as follows: Austrodiscus lopesi (Charopidae; Biomphalaria itaboraiensis (Planorbidae; "Brachypodella" britoi (Urocoptidae; Brasilennea arethusae, Brasilennea guttula, Brasilennea minor (Cerionidae; Bulimulus fazendicus, Bulimulus trindadeae, Cortana carvalhoi, Cyclodontina coelhoi, Itaborahia lamegoi, Leiostracus ferreirai, Plagiodontes aff. dentatus (Orthalicidae; Cecilioides sommeri (Ferussaciidae; Eoborus rotundus, Eoborus sanctijosephi, Eoborus fusiforme (Strophocheilidae; Gastrocopta mezzalirai, Gastrocopta itaboraiensis (Gastrocoptidae; Temesa magalhaesi (Clausiliidae. The species Strobilopsis mauryae was considered a synonym of Brasilennea arethusae; Bulimulus sommeri a synonym of Itaborahia lamegoi; and Vorticifex fluminensis a synonym of Eoborus sanctijosephi. Itaboraí Basin has the most ancient records of the families Orthalicidae, Gastrocoptidae, Ferussaciidae and Strophocheilidae. Moreover, the basin's records of Charopidae, Clausiliidae, Cerionidae, and Urocoptidae are among the most ancient in the world and, among these, those of Cerionidae, Clausiliidae and Urocoptidae deserve special attention since they are greatly removed from these families' current distribution. Additionally, Itaboraí has the most ancient records for the genera Austrodiscus, Brachypodella, Bulimulus, Cecilioides, Cyclodontina, Eoborus, Gastrocopta, Leiostracus, Plagiodontes and Temesa. There are three endemic genera in the basin: Brasilennea, Cortana and Itaborahia. Further discussion on paleobiogeography and evolution of this paleofauna is also provided.Os calc

  2. Abnormalities in bivalve larvae from the Puck Bay (Gulf of Gdansk, southern Baltic Sea) as an indicator of environmental pollution.

    Science.gov (United States)

    Lasota, Rafal; Gierszewska, Katarzyna; Viard, Frédérique; Wolowicz, Maciej; Dobrzyn, Katarzyna; Comtet, Thierry

    2018-01-01

    This study described the occurrence of abnormalities in bivalve larvae from the Puck Bay. Analyses of plankton samples collected in 2012-2013 showed that larval Mytilus trossulus, Mya arenaria, and Cerastoderma glaucum exhibited abnormalities that could indicate adverse environmental impacts. The deformities were mainly in shells, but missing soft tissue fragments and protruding vela were also noted. In addition to larval studies, we analyzed benthic postlarvae of Mytilus trossulus. Interestingly, grooves and notches at different locations of the prodissoconch, dissoconch, and shell margin were observed. Some of these deformations were reminiscent of the indentations found on the shell edge of larvae. Comparing the proportion of abnormal postlarvae to larvae with shell abnormalities suggested that the survival of larvae with shell abnormalities was low. Overall, our results suggested that the ratio of abnormal bivalve larvae could be used as an indicator of the biological effects of hazardous substances in the pelagic environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Molluscan indicator species and their potential use in ecological status assessment using species distribution modeling.

    Science.gov (United States)

    Moraitis, Manos L; Tsikopoulou, Irini; Geropoulos, Antonios; Dimitriou, Panagiotis D; Papageorgiou, Nafsika; Giannoulaki, Marianna; Valavanis, Vasilis D; Karakassis, Ioannis

    2018-05-24

    Marine habitat assessment using indicator species through Species Distribution Modeling (SDM) was investigated. The bivalves: Corbula gibba and Flexopecten hyalinus were the indicator species characterizing disturbed and undisturbed areas respectively in terms of chlorophyll a concentration in Greece. The habitat suitability maps of these species reflected the overall ecological status of the area. The C. gibba model successfully predicted the occurrence of this species in areas with increased physical disturbance driven by chlorophyll a concentration, whereas the habitat map for F. hyalinus showed an increased probability of occurrence in chlorophyll-poor areas, affected mainly by salinity. We advocate the use of C. gibba as a proxy for eutrophication and the incorporation of this species in monitoring studies through SDM methods. For the Mediterranean Sea we suggest the use of F. hyalinus in SDM as an indicator of environmental stability and a possible forecasting tool for salinity fluctuations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Prevalence of Perkinsus marinus (dermo), Haplosporidium nelsoni (MSX), and QPX in bivalves of Delaware's inland bays and quantitative, high-throughput diagnosis of dermo by QPCR.

    Science.gov (United States)

    Ulrich, Paul N; Ewart, John W; Marsh, Adam G

    2007-01-01

    Restoration of oyster reef habitat in the Inland Bays of Delaware was accompanied by an effort to detect and determine relative abundance of the bivalve pathogens Perkinsus marinus, Haplosporidium nelsoni, and QPX. Both the oyster Crassostrea virginica and the clam Mercenaria mercenaria were sampled from the bays. In addition, oysters were deployed at eight sites around the bays as sentinels for the three parasites. Perkinsus marinus prevalence was measured with a real-time, quantitative polymerase chain reaction (PCR) methodology that enabled high-throughput detection of as few as 31 copies of the ribosomal non-transcribed spacer region in 500 ng oyster DNA. The other pathogens were assayed using PCR with species-specific primers. Perkinsus marinus was identified in Indian River Bay at moderate prevalence ( approximately 40%) in both an artificial reef and a wild oyster population whereas sentinel oysters were PCR-negative after 3-months exposure during summer and early fall. Haplosporidium nelsoni was restricted to one oyster deployed in Little Assawoman Bay. QPX and P. marinus were not detected among wild clams. While oysters in these bays have historically been under the greatest threat by MSX, it is apparent that P. marinus currently poses a greater threat to recovery of oyster aquaculture in Delaware's Inland Bays.

  5. Prospecção de moluscos bivalves no estudo da poluição dos rios Cachoeira e Santana em Ilhéus, Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Denise Sande

    2010-06-01

    Full Text Available A survey about the pollution level of the Cachoeira and Santana Rivers (Ilheus, Bahia, Brazil was performed for a quarter, through the assessment of the microbiological quality of water and seafood (Crassostrea rhizophorae - oyster and Tagelus plebeius - razor clam extracted from these rivers. Traditional indicators of pollution such as total coliforms (Ct and thermtolerant coliforms (CT, and total count of micro-organisms, with isolation and identification of Enterobacteriaceae were determined in rivers samples, which exhibited different levels of faecal pollution. An amount of 68 micro-organisms was isolated, distributed in ten species, among them, Salmonella typhi, Escherichia coli and Shigella sp., warning about the risk of consuming these shellfish in nature, even when there is accordance with the laws established for CT. The bivalve prospection to monitor pollution levels was not effective considering CT detection in oysters and moapens. There was also the highest contamination degree in the Cachoeira River, which is used for water distribution in the region and as livelihood source through extractive activities for the riverside population.

  6. Bioavailability and toxicity of metals from a contaminated sediment by acid mine drainage: linking exposure-response relationships of the freshwater bivalve Corbicula fluminea to contaminated sediment.

    Science.gov (United States)

    Sarmiento, Aguasanta M; Bonnail, Estefanía; Nieto, José Miguel; DelValls, Ángel

    2016-11-01

    Streams and rivers strongly affected by acid mine drainage (AMD) have legal vacuum in terms of assessing the water toxicity, since the use of conventional environmental quality biomarkers is not possible due to the absence of macroinvertebrate organisms. The Asian clam Corbicula fluminea has been widely used as a biomonitor of metal contamination by AMD in freshwater systems. However, these clams are considered an invasive species in Spain and the transplantation in the field study is not allowed by the Environmental Protection Agency. To evaluate the use of the freshwater bivalve C. fluminea as a potential biomonitor for sediments contaminated by AMD, the metal bioavailability and toxicity were investigated in laboratory by exposure of clams to polluted sediments for 14 days. The studied sediments were classified as slightly contaminated with As, Cr, and Ni; moderately contaminated with Co; considerably contaminated with Pb; and heavily contaminated with Cd, Zn, and specially Cu, being reported as very toxic to Microtox. On the fourth day of the exposure, the clams exhibited an increase in concentration of Ga, Ba, Sb, and Bi (more than 100 %), followed by Co, Ni, and Pb (more than 60 %). After the fourth day, a decrease in concentration was observed for almost all metals studied except Ni. An allometric function was used to determine the relationship between the increases in metal concentration in soft tissue and the increasing bioavailable metal concentrations in sediments.

  7. 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

  8. Biochemical and behavioural responses of the endobenthic bivalve Scrobicularia plana to silver nanoparticles in seawater and microalgal food.

    Science.gov (United States)

    Buffet, Pierre-Emmanuel; Pan, Jin-Fen; Poirier, Laurence; Amiard-Triquet, Claude; Amiard, Jean-Claude; Gaudin, Pierre; Risso-de Faverney, Christine; Guibbolini, Marielle; Gilliland, Douglas; Valsami-Jones, Eugenia; Mouneyrac, Catherine

    2013-03-01

    Because of their bactericidal effects, Ag nanoparticles (Ag NPs) have promising industrial development but could lead to potential ecological risks. The aim of this study was to examine the uptake and effect of silver (soluble or as lactate Ag NPs of 40 nm) at low concentrations (10 μg L(-1)) in the endobenthic bivalve Scrobicularia plana exposed, for 14 days, directly (water) or via the diet (microalgae). The stability of Ag NPs in seawater was examined using dynamic light scattering. Release of soluble Ag from Ag NPs in the experimental media was quantified by using diffusive gradient in thin film. Bioaccumulation of Ag in bivalves was measured by electrothermal atomic absorption spectrometry. Behavioural and biochemical biomarkers were determined in bivalves. Aggregation of Ag NPs and the release of soluble Ag from Ag NPs were observed in the experimental media. For both forms of Ag, bioaccumulation was much more important for waterborne than for dietary exposure. The response of oxidative stress biomarkers (catalase, glutathion S-transferase, superoxide dismutase) was more important after dietary than waterborne exposure to Ag (soluble and NPs). These defences were relatively efficient since they led to a lack of response of damage biomarkers. Burrowing was not affected for bivalves exposed directly or through the diet to both Ag forms but feeding behaviour was impaired after 10 days of dietary exposure. Since no differences of responses to Ag either soluble or nanoparticulate were observed, it seems that labile Ag released from Ag NPs was mainly responsible for toxicity. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Polychlorinated biphenyls, organochlorine pesticides and polycyclic aromatic hydrocarbons in a one-off global survey of bivalves

    DEFF Research Database (Denmark)

    Vorkamp, Katrin; Strand, Jakob; Christensen, Jan H.

    2010-01-01

    During the Danish Galathea 3 expedition, bivalve samples were collected at the Faroe Islands, Greenland, Ghana, South Africa, Australia, Solomon Islands, New Zealand, Chile, US Virgin Islands, Boston, Newfoundland and Shetland Islands and analysed for organochlorines and PAHs. Concentration...... in terms of PCB and PAH levels, while other Greenland samples came closest to representing PAH background levels. Several locations had undetectable organochlorine levels, including Hobart and Chile, which had the lowest Sigma PAH concentrations (group the stations...

  10. A mollusk VDR/PXR/CAR-like (NR1J) nuclear receptor provides insight into ancient detoxification mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Cruzeiro, Catarina, E-mail: catarinarcruzeiro@hotmail.com [ICBAS - Institute of Biomedical Sciences Abel Salazar, U. Porto - University of Porto (Portugal); CIIMAR/CIMAR - Interdisciplinary Center of Marine and Environmental Research, U. Porto (Portugal); Lopes-Marques, Mónica, E-mail: monicaslm@hotmail.com [ICBAS - Institute of Biomedical Sciences Abel Salazar, U. Porto - University of Porto (Portugal); CIIMAR/CIMAR - Interdisciplinary Center of Marine and Environmental Research, U. Porto (Portugal); Ruivo, Raquel, E-mail: ruivo.raquel@gmail.com [CIIMAR/CIMAR - Interdisciplinary Center of Marine and Environmental Research, U. Porto (Portugal); Rodrigues-Oliveira, Nádia, E-mail: nadia.oliveira@ciimar.up.pt [CIIMAR/CIMAR - Interdisciplinary Center of Marine and Environmental Research, U. Porto (Portugal); Santos, Miguel M., E-mail: santos@ciimar.up.pt [CIIMAR/CIMAR - Interdisciplinary Center of Marine and Environmental Research, U. Porto (Portugal); FCUP - Faculty of Sciences, Department of Biology, U. Porto (Portugal); Rocha, Maria João, E-mail: mjsrocha@netcabo.pt [ICBAS - Institute of Biomedical Sciences Abel Salazar, U. Porto - University of Porto (Portugal); CIIMAR/CIMAR - Interdisciplinary Center of Marine and Environmental Research, U. Porto (Portugal); Rocha, Eduardo, E-mail: erocha@icbas.up.pt [ICBAS - Institute of Biomedical Sciences Abel Salazar, U. Porto - University of Porto (Portugal); CIIMAR/CIMAR - Interdisciplinary Center of Marine and Environmental Research, U. Porto (Portugal); Castro, L. Filipe C., E-mail: filipe.castro@ciimar.up.pt [CIIMAR/CIMAR - Interdisciplinary Center of Marine and Environmental Research, U. Porto (Portugal); FCUP - Faculty of Sciences, Department of Biology, U. Porto (Portugal)

    2016-05-15

    Highlights: • A nuclear receptor orthologue of the NR1J group is isolated from a mollusc. • The molluscan NR1J transactivates gene expression upon exposure to okadaic acid but not a pesticide, esfenvarelate and triclosan. • Lineage specific gene duplications and gene loss have occurred in the NR1J of protostomes with likely impacts on detoxification mechanisms. - Abstract: The origin and diversification of the metazoan endocrine systems represents a fundamental research issue in biology. Nuclear receptors are critical components of these systems. A particular group named VDR/PXR/CAR (NR1I/J) is central in the mediation of detoxification responses. While orthologues have been thoroughly characterized in vertebrates, a sparse representation is currently available for invertebrates. Here, we provide the first isolation and characterization of a lophotrochozoan protostome VDR/PXR/CAR nuclear receptor (NR1J), in the estuarine bivalve the peppery furrow shell (Scrobicularia plana). Using a reporter gene assay, we evaluated the xenobiotic receptor plasticity comparing the human PXR with the S. plana NR1Jβ. Our results show that the molluscan receptor responds to a natural toxin (okadaic acid) in a similar fashion to that reported for other invertebrates. In contrast, the pesticide esfenvalerate displayed a unique response, since it down regulated transactivation at higher concentrations, while for triclosan no response was observed. Additionally, we uncovered lineage specific gene duplications and gene loss in the gene group encoding NRs in protostomes with likely impacts on the complexity of detoxification mechanisms across different phyla. Our findings pave the way for the development of multi-specific sensor tools to screen xenobiotic compounds acting via the NR1I/J group.

  11. A mollusk VDR/PXR/CAR-like (NR1J) nuclear receptor provides insight into ancient detoxification mechanisms

    International Nuclear Information System (INIS)

    Cruzeiro, Catarina; Lopes-Marques, Mónica; Ruivo, Raquel; Rodrigues-Oliveira, Nádia; Santos, Miguel M.; Rocha, Maria João; Rocha, Eduardo; Castro, L. Filipe C.

    2016-01-01

    Highlights: • A nuclear receptor orthologue of the NR1J group is isolated from a mollusc. • The molluscan NR1J transactivates gene expression upon exposure to okadaic acid but not a pesticide, esfenvarelate and triclosan. • Lineage specific gene duplications and gene loss have occurred in the NR1J of protostomes with likely impacts on detoxification mechanisms. - Abstract: The origin and diversification of the metazoan endocrine systems represents a fundamental research issue in biology. Nuclear receptors are critical components of these systems. A particular group named VDR/PXR/CAR (NR1I/J) is central in the mediation of detoxification responses. While orthologues have been thoroughly characterized in vertebrates, a sparse representation is currently available for invertebrates. Here, we provide the first isolation and characterization of a lophotrochozoan protostome VDR/PXR/CAR nuclear receptor (NR1J), in the estuarine bivalve the peppery furrow shell (Scrobicularia plana). Using a reporter gene assay, we evaluated the xenobiotic receptor plasticity comparing the human PXR with the S. plana NR1Jβ. Our results show that the molluscan receptor responds to a natural toxin (okadaic acid) in a similar fashion to that reported for other invertebrates. In contrast, the pesticide esfenvalerate displayed a unique response, since it down regulated transactivation at higher concentrations, while for triclosan no response was observed. Additionally, we uncovered lineage specific gene duplications and gene loss in the gene group encoding NRs in protostomes with likely impacts on the complexity of detoxification mechanisms across different phyla. Our findings pave the way for the development of multi-specific sensor tools to screen xenobiotic compounds acting via the NR1I/J group.

  12. Manganese in the shell of the bivalve Mytilus edulis: Seawater Mn or physiological control?

    Science.gov (United States)

    Freitas, Pedro S.; Clarke, Leon J.; Kennedy, Hilary; Richardson, Christopher A.

    2016-12-01

    Manganese in the shell calcite of marine bivalves has been suggested to reflect ambient seawater Mn concentrations, thus providing a high-resolution archive of past seawater Mn concentrations. However, a quantitative relationship between seawater Mn and shell Mn/Ca ratios, as well as clear understanding of which process(es) control(s) shell Mn/Ca, are still lacking. Blue mussels, Mytilus edulis, were grown in a one-year duration field experiment in the Menai Strait, U.K., to study the relationship between seawater particulate and dissolved Mn2+ concentrations and shell calcite Mn/Ca ratios. Shell Mn/Ca showed a well-defined intra-annual double-peak, with maximum values during early spring and early summer and low values during autumn and winter. Seawater particulate Mn peaked during winter and autumn, with a series of smaller peaks during spring and summer, whereas dissolved Mn2+ exhibited a marked single maximum during late-spring to early-summer, being low during the remainder of the year. Consequently, neither seawater particulate Mn nor dissolved Mn2+ concentrations explain the intra-annual variation of shell Mn/Ca ratios. A physiological control on shell Mn/Ca ratios is evident from the strong similarity and timing of the double-peaked intra-annual variations of Mn/Ca and shell growth rate (SGR), the latter corresponding to periods of increased metabolic activity (as indicated by respiration rate). It is thus likely that in M. edulis SGR influences shell Mn/Ca by altering the concentration or activity of Mn2+ within the extra-pallial fluid (EPF), by changing the flux of Mn into or the proportion of protein bound Mn within the EPF. By linking shell Mn/Ca ratios to the endogenous and environmental factors that determine growth and metabolic activity, this study helps to explain the lack of a consistent relationship between shell Mn/Ca in marine bivalve shell calcite and seawater particulate and dissolved Mn2+ concentrations. The use of Mn content from M. edulis

  13. How the fluctuations of water levels affect populations of invasive bivalve Corbicula fluminea (Müller, 1774 in a Neotropical reservoir?

    Directory of Open Access Journals (Sweden)

    LRP. Paschoal

    Full Text Available Corbicula fluminea is an invasive bivalve responsible for several environmental and financial problems around the globe. Despite the invasive potential of this species, it suffers certain restrictions in lentic environments due to natural phenomena that significantly affect its population structure (e.g. water column fluctuation and sunlight exposure. The present study addresses how temporal decline of the water level in a Neotropical reservoir and exposure to sunlight affect the population structure of C. fluminea. Samplings were carried out twice in the reservoir of Furnas Hydroelectric Power Station (HPS (Minas Gerais, Brazil, in 2011 and 2012. Population density, spatial distribution and mean shell length of C. fluminea were estimated for each year after sampling in 51 quadrats (0.0625m2 placed on three transects at different distances along the reservoir margins (0, 10 and 20 m from a fixed-point. We observed a predominance of C. fluminea in both years, with a simultaneous gradual decrease in density and richness of native species in the sampling area. Significant differences in density of C. fluminea were registered at different distances from the margin, and are related to the temporal variability of physical conditions of the sediment and water in these environments. We also registered a trend toward an increase in the density and aggregation of C. fluminea as we moved away from the margin, due to the greater stability of these areas (>10 m. The mean shell length of C. fluminea showed significant difference between the distinct distances from the margin and during the years, as well as the interaction of these factors (Distances vs.Years. These results were associated with the reproductive and invasive capacity of this species. This study reveals that these temporal events (especially water column fluctuation may cause alterations in density, spatial distribution and mean shell length of C. fluminea and the composition of the native

  14. 76 FR 61825 - Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List 29 Mollusk...

    Science.gov (United States)

    2011-10-05

    ... program. Inclusion or removal of individual species and subspecies in the special status species program... hesperian is threatened by fire, pesticide application, recreation, and invasive species (CBD et al. 2008... pesticides, recreational activities involving motor vehicles, and invasive species may negatively impact some...

  15. Are Mussels Always the Best Bioindicators? Comparative Study on Biochemical Responses of Three Marine Invertebrate Species to Chronic Port Pollution.

    Science.gov (United States)

    Laitano, María V; Fernández-Gimenez, Analía V

    2016-07-01

    Bivalves have traditionally been considered good bioindicators due to their sensitivity to pollution, among other features. This characteristic is shared by several other non-bivalve species as well, though studies in this respect remain scarce. This work aims to compare biomarker sensitivity to chronic port pollution among three intertidal invertebrate species with good bioindicator characteristics. Mussels' immunological (phenoloxidase and peroxidases) and biotransformation (glutathione-S-transferase) responses were contrasted against those of limpets and barnacles. The three species under study evidenced activity of all the enzymes measured, although with differences. Barnacle Balanus glandula was the most sensitive species showing pollution modulation of the three enzymes, which suggests that mussels would not always be the best bioindicator species among marine invertebrates depending on the responses that are assessed.

  16. The bivalve Anopaea (Inoceramidae) from the Upper Jurassic-lowermost Cretaceous of Mexico

    Science.gov (United States)

    Zell, Patrick; Crame, J. Alistair; Stinnesbeck, Wolfgang; Beckmann, Seija

    2015-07-01

    In Mexico, the Upper Jurassic to lowermost Cretaceous La Casita and coeval La Caja and La Pimienta formations are well-known for their abundant and well-preserved marine vertebrates and invertebrates. The latter include conspicuous inoceramid bivalves of the genus Anopaea not formally described previously from Mexico. Anopaea bassei (Lecolle de Cantú, 1967), Anopaea cf. stoliczkai (Holdhaus, 1913), Anopaea cf. callistoensis Crame and Kelly, 1995 and Anopaea sp. are rare constituents in distinctive Tithonian-lower Berriasian levels of the La Caja Formation and one Tithonian horizon of the La Pimienta Formation. Anopaea bassei was previously documented from the Tithonian of central Mexico and Cuba, while most other members of Anopaea described here are only known from southern high latitudes. The Mexican assemblage also includes taxa which closely resemble Anopaea stoliczkai from the Tithonian of India, Indonesia and the Antarctic Peninsula, and Anopaea callistoensis from the late Tithonian to ?early Berriasian of the Antarctic Peninsula. Our new data expand the palaeogeographical distribution of the high latitude Anopaea to the Gulf of Mexico region and substantiate faunal exchange, in the Late Jurassic-earliest Cretaceous, between Mexico and the Antarctic Realm.

  17. Intrinsic hierarchical structural imperfections in a natural ceramic of bivalve shell with distinctly graded properties.

    Science.gov (United States)

    Jiao, Da; Liu, Zengqian; Zhang, Zhenjun; Zhang, Zhefeng

    2015-07-22

    Despite the extensive investigation on the structure of natural biological materials, insufficient attention has been paid to the structural imperfections by which the mechanical properties of synthetic materials are dominated. In this study, the structure of bivalve Saxidomus purpuratus shell has been systematically characterized quantitatively on multiple length scales from millimeter to sub-nanometer. It is revealed that hierarchical imperfections are intrinsically involved in the crossed-lamellar structure of the shell despite its periodically packed platelets. In particular, various favorable characters which are always pursued in synthetic materials, e.g. nanotwins and low-angle misorientations, have been incorporated herein. The possible contributions of these imperfections to mechanical properties are further discussed. It is suggested that the imperfections may serve as structural adaptations, rather than detrimental defects in the real sense, to help improve the mechanical properties of natural biological materials. This study may aid in understanding the optimizing strategies of structure and properties designed by nature, and accordingly, provide inspiration for the design of synthetic materials.

  18. Draft Genome of the Pearl Oyster Pinctada fucata: A Platform for Understanding Bivalve Biology

    Science.gov (United States)

    Takeuchi, Takeshi; Kawashima, Takeshi; Koyanagi, Ryo; Gyoja, Fuki; Tanaka, Makiko; Ikuta, Tetsuro; Shoguchi, Eiichi; Fujiwara, Mayuki; Shinzato, Chuya; Hisata, Kanako; Fujie, Manabu; Usami, Takeshi; Nagai, Kiyohito; Maeyama, Kaoru; Okamoto, Kikuhiko; Aoki, Hideo; Ishikawa, Takashi; Masaoka, Tetsuji; Fujiwara, Atushi; Endo, Kazuyoshi; Endo, Hirotoshi; Nagasawa, Hiromichi; Kinoshita, Shigeharu; Asakawa, Shuichi; Watabe, Shugo; Satoh, Nori

    2012-01-01

    The study of the pearl oyster Pinctada fucata is key to increasing our understanding of the molecular mechanisms involved in pearl biosynthesis and biology of bivalve molluscs. We sequenced ∼1150-Mb genome at ∼40-fold coverage using the Roche 454 GS-FLX and Illumina GAIIx sequencers. The sequences were assembled into contigs with N50 = 1.6 kb (total contig assembly reached to 1024 Mb) and scaffolds with N50 = 14.5 kb. The pearl oyster genome is AT-rich, with a GC content of 34%. DNA transposons, retrotransposons, and tandem repeat elements occupied 0.4, 1.5, and 7.9% of the genome, respectively (a total of 9.8%). Version 1.0 of the P. fucata draft genome contains 23 257 complete gene models, 70% of which are supported by the corresponding expressed sequence tags. The genes include those reported to have an association with bio-mineralization. Genes encoding transcription factors and signal transduction molecules are present in numbers comparable with genomes of other metazoans. Genome-wide molecular phylogeny suggests that the lophotrochozoan represents a distinct clade from ecdysozoans. Our draft genome of the pearl oyster thus provides a platform for the identification of selection markers and genes for calcification, knowledge of which will be important in the pearl industry. PMID:22315334

  19. [Achatina fulica Bowdich (1822) a new host of Cryptosporidium (Apicomplexa, Cryptosporidiidae) species].

    Science.gov (United States)

    Schiffler, Cinthia L; Gomes, Francimar F; Ederli, Nicole B; De Oliveira, Francisco Carlos R

    2008-09-01

    With the objective of isolate Cryptosporidium spp. in Achatina fulica s feces, 50 mollusks were collected in nine neighborhoods of the municipal of Campos dos Goytacazes, RJ to the observation of oocysts in feces. The snails were put in individuals containers and fed with water and green vegetables ad libitum until be collected a gram of feces per animal. The samples were conditioned in tubes with formalin 10% and later smear of feces were made and dyed by Ziechl-Neelsen modified technique. Of the 50 samples examined, 26 (52%) were positive for the presence of oocysts of Cryptosporidium spp. The morphology and morphometry of the oocysts showed that are a great morphologic variability. Considering the obtained results, the mollusk Achatina fulica is a host of Cryptosporidium species and can participate in the epidemic chain of the cryptosporidiosis.

  20. A study of the uptake and toxicity of some stable and radioactive pollutants in marine organisms: antimony, silver, cobalt and strontium in mollusks, crustaceans and teleosts

    International Nuclear Information System (INIS)

    Amiard, J.-C.

    1978-10-01

    Qualitative and quantitative results following direct aquatic contamination of mollusks, crustaceans and teleosts by 125 Sb, 110 Ag, 60 Co, 85 Sr are reported. The effects of a number of biotic and abiotic parameters on the contamination of the various organisms and the distribution and elimination of the radionuclides in the tissues were investigated. The transfer of sup(110m)Ag, 60 Co and 125 Sb was studied in several benthic food chains. The transfer factor (F.T.) between a given trophic level and the initial environment (seawater) was determined as well as various physiological parameters (percentages ingested, assimilated, eliminated via the feces or urine and/or the gills. Elimination and tissue uptake were followed in mollusks and crustaceans. The consequences of contamination by stable and radioactive pollutants on plants and animals were considered. Acute (lethal) toxicity of various metals or metalloids on marine organisms were quantified. More sensitive sublethal tests considering physiological functions or behaviour were used. Irradiation doses to experiment animals were calculated, showing the importance of the (internal or external distribution of radionuclides and individual geometries on the total exposure dose [fr

  1. Congener-specific distribution and bioaccumulation of short-chain chlorinated paraffins in sediments and bivalves of the Bohai Sea, China.

    Science.gov (United States)

    Ma, Xindong; Chen, Chen; Zhang, Haijun; Gao, Yuan; Wang, Zhen; Yao, Ziwei; Chen, Jiping; Chen, Jingwen

    2014-02-15

    Short-chain chlorinated paraffins (SCCPs) are a new type of persistent organic pollutants that are of great environmental concern because of their wide distribution. In this study, surface sediments and bivalve samples were collected from the coastal area of the Bohai Sea in China. Total SCCP (ΣSCCP) concentrations in surface sediments and bivalves ranged from 97.4 ng g(-1) dry weight (dw) to 1756.7 ng g(-1) dw and 476.4-3269.5 ng g(-1) dw, respectively. C10-CPs and C11-CPs were the predominant homologue groups in all sediments and bivalves. Specific congener composition analysis and correspondence analysis indicated that the local SCCP source mainly came from CP-42 and CP-52 products, and riverine input had an important function. The biota-sediment accumulation factors of ΣSCCPs for bivalves ranged from 1.08 to 1.61, and a significant correlation indicated that the SCCP congener with higher chlorination degree was more likely to be accumulated in bivalves. Copyright © 2014. Published by Elsevier Ltd.

  2. Burrowing behavior of a deposit feeding bivalve predicts change in intertidal ecosystem state

    Directory of Open Access Journals (Sweden)

    Tanya Joan Compton

    2016-03-01

    Full Text Available Behavior has a predictive power that is often underutilized as a tool for signaling ecological change. The burrowing behavior of the deposit feeding bivalve Macoma balthica reflects a typical food-safety trade-off. The choice to live close to the sediment surface comes at a risk of predation and is a decision made when predation danger, food intake rates or future fitness prospects are low. In parts of the Dutch Wadden Sea, Macoma populations declined by 90% in the late 1990s, in parallel with large-scale mechanical cockle-dredging activities. During this decline, the burrowing depth of Macoma became shallow and was correlated with the population decline in the following year, indicating that it forecasted population change. Recently, there has been a series of large recruitment events in Macoma. According to the food-safety trade-off, we expected that Macoma should now live deeper, and have a higher body condition in association with this change in depth of living. Indeed, we observed that Macoma now lives deeper and that living depth in a given year forecasted population growth to the next year, especially in individuals larger than 14 mm. As living depth and body condition were strongly correlated in individuals larger than 14 mm, larger Macoma could be living deeper to protect their reproductive assets. Our results confirmed that burrowing depth signals impending population change and, together with body condition, can provide an early warning signal of ecological change. We suggest that population recovery is being driven by improved intertidal habitat quality in the Dutch Wadden Sea, rather than by the proposed climate-change related effects. This shift in ecosystem state is suggested to include the recovery of diatom habitat in the top layer of the sediment after cockle-dredging ended.

  3. Eocene Antarctic seasonality inferred from high-resolution stable isotope profiles of fossil bivalves and driftwood

    Science.gov (United States)

    Judd, E. J.; Ivany, L. C.; Miklus, N. M.; Uveges, B. T.; Junium, C. K.

    2017-12-01

    The Eocene Epoch was a time of large-scale global climate change, experiencing both the warmest temperatures of the Cenozoic and the onset of southern hemisphere glaciation. The record of average global temperatures throughout this transition is reasonably well constrained, however considerably less is known about the accompanying changes in seasonality. Seasonally resolved temperature data provide a wealth of information not readily available from mean annual temperature data alone. These data are particularly important in the climatically sensitive high latitudes, as they can elucidate the means by which climate changes and the conditions necessary for the growth of ice sheets. Several recent studies, however, have suggested the potential for monsoonal precipitation regimes in the early-middle Eocene high latitudes, which complicates interpretation of seasonally resolved oxygen isotope records in shallow nearshore marine settings. Seasonal precipitation and runoff could create a brackish, isotopically depleted lens in these environments, depleting summertime δ18Ocarb and thereby inflating the inferred mean and range of isotope-derived temperatures. Here, we assess intra-annual variations in temperature in shallow nearshore Antarctic waters during the middle and late Eocene, inferred from high-resolution oxygen isotope profiles from accretionary bivalves of the La Meseta Formation, Seymour Island, Antarctica. To address concerns related to precipitation and runoff, we also subsample exceptionally preserved fossil driftwood from within the formation and use seasonal differences in δ13Corg values to estimate the ratio of summertime to wintertime precipitation. Late Eocene oxygen isotope profiles exhibit strongly attenuated seasonal amplitudes and more enriched mean annual values in comparison with data from the middle Eocene. Preliminary fossil wood data are not indicative of a strongly seasonal precipitation regime, implying that intra-annual variation in oxygen

  4. 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.

  5. Biological Carbon Dioxide Assimilation Process Using Marine Phytoplankton Tetraselmis suecica and Bivalve Perna viridis

    Directory of Open Access Journals (Sweden)

    Sirichai Dharmvanij

    2012-01-01

    Full Text Available The Biological CO2 assimilation process using marine phytoplankton and marine bivalve was evaluated by carbon assimilation of the green mussel Perna viridis fed with Tetraselmis suecica under laboratory condition. Incorporation of carbon dioxide into phytoplankton biomass was performed through aeration. The experiment consisted of three treatments i.e. mussels without feeding (Control, mussels fed with T. suecica cultured with air (Treatment 1: T-Air, and mussels fed with T. suecica cultured with 1.5% CO2 in air (Treatment 2: T-CO2. The results showed that growth of mussels in T-Air and T-CO2 was 22.4 ± 4.0 mg/individual/day and 28.9 ± 12.3 mg/individual/day, respectively, which was significantly higher than control (mussels without feeding. Growth of mussels in T-Air was significantly lower than in T-CO2. Carbon content in shell (15.59 ± 0.57 % D.W. and meat (38.28 ± 1.72 % D.W. of mussels fed with aerated T. suecica (T-Air was significantly higher than that found in mussels fed with 1.5% CO2 T. suecica (14.2 ± 0.47 and 36.61± 0.43 % D.W. in shell and in meat, respectively (p≤0.05. With T-Air, 1.95±0.27 and 9.36±1.24% of carbon from T. suecica cells was assimilated into shell and meat of the mussel, respectively, while in T-CO2 , carbon assimilation from T. suecica cells in shell and meat was 2.19±0.55 and 11.22±2.76% respectively.

  6. Effect of chronic selenium exposure on the freshwater bivalve Corbicula fluminea

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, E.; Adam, C.; Massabuau, J.C.; Garnier-Laplace, J. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    Selenium is essential for most of living organisms. In oxic to moderately oxic fresh-waters, Se exists predominantly in the (+VI) and (+IV) oxidation states as selenate (SeO{sub 4}{sup 2-}) and selenite (SeO{sub 3}{sup 2-}) respectively, whereas in the biota it is incorporated as Se(-II) into seleno-proteins or amino-acids, or as elemental selenium Se(0). At low concentrations, it acts against oxidative damages mainly as the glutathione peroxidase seleno-dependant, but it may be toxic at higher levels (for example, by replacing sulphur in important biomolecules). In filter feeders, such as the freshwater bivalve Corbicula fluminea, selected as biological model, the ventilation activity is a primary limiting step that controls the water influx and therefore the delivery of contaminants. Consequently, a series of short-term experiments were performed to study the effects of different dissolved Se concentrations and forms (selenite; selenate; selenomethionine) on the ventilation activity of Corbicula fluminea and Se tissular distribution. The modification of the ventilation activity of the Se-exposed groups, in comparison to this of reference groups (not exposed to Se) varied greatly according to the form and the concentrations of the Se used. Se concentrations in tissues indicated that selenite was the less bioavailable form whereas selenomethionine displayed the opposite trend. On the basis of this set of experiments, a limited number of conditions have been selected to provide highly contrasting ventilation flow rates and selenium bioaccumulation levels, in order to study the effects of long term exposures, i) at the molecular level, by measuring bio-markers of oxidative stress (forms of glutathione, glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase, and bio-marker of genotoxicity (comet assay), ii) at the (sub)cellular level by analysing Se micro-localisation in target organs and iii) at the individual level by monitoring the variation

  7. [Centrocestus formosanus (Opisthorchiida: Heterophyidae) as a cause of death in gray tilapia fry Oreochromis niloticus (Perciforme: Cichlidae) in the dry Pacific of Costa Rica].

    Science.gov (United States)

    Arguedas Cortés, Donald; Dolz, Gaby; Romero Zúñiga, Juan J; Jiménez Rocha, Ana E; León Alán, Dennis

    2010-12-01

    Centrocestusformosanus is a zoonotic trematode from Asia and has been mainly associated as cause of death of cultured fish. To identify pathogen trematode species in tilapia fry (Oreochromis niloticus) and to determine mollusks hosting these parasites, freshwater mollusks were collected from tilapia cultured ponds and experimental infections were carried out with tilapia fries and different mollusk species. A total of 907 freshwater mollusks were obtained from tilapia ponds and were identified to species level, four gastropods and one bivalve were determined: Melania tuberculata, Melanoides turricula, Pomacea flagellata, Haitia cubensis and Anodontiles luteola. For the first time, the presence of M. turricula and H. cubensis are reported in Costa Rica. Seven morphotypes of cercariae (Xifiodiocercaria, Equinostoma, Oftalmocercaria, Parapleurolofocercus, Cistocerca, Furcocercaria and Leptocercaria) parasitizing all five species of mollusks were found, all of distome type. Experimental exposure of tilapia fry to M. tuberculata demonstrated that the parapleurolofocercus morphotype found in the mollusk is in accordance with the finding of C. formosanus in tilapia fry. An abundance and mean intensity of 1018-1027 digeneans per gill in each exposed fish was determined. Centrocestus formosanus is reported for the first time in Costa Rica, for which the primary and secondary intermediate hosts were also determined.

  8. A malacological survey in the Manso Power Plant, State of Mato Grosso, Brazil: new records of freshwater snails, including transmitters of schistosomiasis and exotic species

    Directory of Open Access Journals (Sweden)

    Monica Ammon Fernandez

    2014-07-01

    Full Text Available Introduction Schistosomiasis is a parasitic disease of public health concern in Brazil, and the construction of hydroelectric dams, in addition to increasing permanent human settlement and tourism, has created conditions suitable for the establishment of mollusks that can transmit schistosomiasis. Such areas require a number of actions to prevent the establishment of schistosomiasis. This paper reports on a freshwater malacological survey carried out in the geographical area of the Manso Power Plant. Methods Mollusks were collected in 18 municipalities in the State of Mato Grosso between February 2002 and February 2004 (qualitative study and from April 2009 to February 2011 (quantitative study. Results Thirty-one species of mollusks were collected, including newly recorded species (Antillorbis nordestensis and Burnupia ingae. In addition, the geographic distributions of known species, including Biomphalaria straminea, a snail vector of Schistosoma mansoni, were expanded. A total of 4,507 specimens were collected in the APM Manso reservoir (Usina Hidrelétrica de Aproveitamento Múltiplo de Manso during the quantitative study, and Biomphalaria amazonica was found in six of the 10 localities analyzed. The Afroasiatic species Melanoides tuberculata, introduced after February 2009, was the dominant species (relative abundance 94.96%. Conclusions The study area is epidemiologically important due to the occurrence of B. straminea and B. amazonica, which are vectors of schistosomiasis, and M. tuberculata, a snail host of Centrocestus formosanus, which is responsible for centrocestiasis transmission. Observations of M. tuberculata and the exotic freshwater clams Corbicula fluminea and Corbicula largillierti raise concerns about biodiversity.

  9. Interactions of cationic polystyrene nanoparticles with marine bivalve hemocytes in a physiological environment: Role of soluble hemolymph proteins

    Energy Technology Data Exchange (ETDEWEB)

    Canesi, Laura, E-mail: Laura.Canesi@unige.it [Dept. of Earth, Environmental and Life Sciences – DISTAV, University of Genoa (Italy); Ciacci, Caterina [Dept. of Biomolecular Sciences – DIBS, University of Urbino (Italy); Fabbri, Rita; Balbi, Teresa [Dept. of Earth, Environmental and Life Sciences – DISTAV, University of Genoa (Italy); Salis, Annalisa; Damonte, Gianluca [Centre of Excellence for Biomedical Research – CEBR, University of Genoa (Italy); Cortese, Katia [Department of Experimental Medicine – DIMES, University of Genoa (Italy); Caratto, Valentina [Dept. of Earth, Environmental and Life Sciences – DISTAV, University of Genoa (Italy); Monopoli, Marco P. [Centre for BioNanoInteractions, School of Chemistry and Chemical Biology, University College Dublin (Ireland); Department of Pharmaceutical and Medical Chemistry, Royal College of Surgeons, 123 St. Stephen Green, Dublin (Ireland); Dawson, Kenneth [Centre for BioNanoInteractions, School of Chemistry and Chemical Biology, University College Dublin (Ireland); Bergami, Elisa; Corsi, Ilaria [Dept. of Physical, Earth and Environmental Sciences, University of Siena (Italy)

    2016-10-15

    The bivalve Mytilus galloprovincialis has proven as a suitable model invertebrate for evaluating the potential impact of nanoparticles (NPs) in the marine environment. In particular, in mussels, the immune system represents a sensitive target for different types of NPs. In environmental conditions, both NP intrinsic properties and those of the receiving medium will affect particle behavior and consequent bioavailability/uptake/toxicity. However, the evaluation of the biological effects of NPs requires additional understanding of how, once within the organism, NPs interact at the molecular level with cells in a physiological environment. In mammalian systems, different NPs associate with serum soluble components, organized into a “protein corona”, which affects particle interactions with target cells. However, no information is available so far on the interactions of NPs with biological fluids of aquatic organisms. In this work, the influence of hemolymph serum (HS) on the in vitro effects of amino modified polystyrene NPs (PS-NH{sub 2}) on Mytilus hemocytes was investigated. Hemocytes were incubated with PS-NH{sub 2} suspensions in HS (1, 5 and 50 µg/mL) and the results were compared with those obtained in ASW medium. Cell functional parameters (lysosomal membrane stability, oxyradical production, phagocytosis) were evaluated, and morphological changes were investigated by TEM. The activation state of the signalling components involved in Mytilus immune response (p38 MAPK and PKC) was determined. The results show that in the presence of HS, PS-NH{sub 2} increased cellular damage and ROS production with respect to ASW medium. The effects were apparently mediated by disregulation of p38 MAPK signalling. The formation of a PS-NH{sub 2}-protein corona in HS was investigated by centrifugation, and 1D- gel electrophoresis and nano-HPLC-ESI-MS/MS. The results identified the Putative C1q domain containing protein (MgC1q6) as the only component of the PS-NH{sub 2} hard

  10. Interactions of cationic polystyrene nanoparticles with marine bivalve hemocytes in a physiological environment: Role of soluble hemolymph proteins

    International Nuclear Information System (INIS)

    Canesi, Laura; Ciacci, Caterina; Fabbri, Rita; Balbi, Teresa; Salis, Annalisa; Damonte, Gianluca; Cortese, Katia; Caratto, Valentina; Monopoli, Marco P.; Dawson, Kenneth; Bergami, Elisa; Corsi, Ilaria

    2016-01-01

    The bivalve Mytilus galloprovincialis has proven as a suitable model invertebrate for evaluating the potential impact of nanoparticles (NPs) in the marine environment. In particular, in mussels, the immune system represents a sensitive target for different types of NPs. In environmental conditions, both NP intrinsic properties and those of the receiving medium will affect particle behavior and consequent bioavailability/uptake/toxicity. However, the evaluation of the biological effects of NPs requires additional understanding of how, once within the organism, NPs interact at the molecular level with cells in a physiological environment. In mammalian systems, different NPs associate with serum soluble components, organized into a “protein corona”, which affects particle interactions with target cells. However, no information is available so far on the interactions of NPs with biological fluids of aquatic organisms. In this work, the influence of hemolymph serum (HS) on the in vitro effects of amino modified polystyrene NPs (PS-NH 2 ) on Mytilus hemocytes was investigated. Hemocytes were incubated with PS-NH 2 suspensions in HS (1, 5 and 50 µg/mL) and the results were compared with those obtained in ASW medium. Cell functional parameters (lysosomal membrane stability, oxyradical production, phagocytosis) were evaluated, and morphological changes were investigated by TEM. The activation state of the signalling components involved in Mytilus immune response (p38 MAPK and PKC) was determined. The results show that in the presence of HS, PS-NH 2 increased cellular damage and ROS production with respect to ASW medium. The effects were apparently mediated by disregulation of p38 MAPK signalling. The formation of a PS-NH 2 -protein corona in HS was investigated by centrifugation, and 1D- gel electrophoresis and nano-HPLC-ESI-MS/MS. The results identified the Putative C1q domain containing protein (MgC1q6) as the only component of the PS-NH 2 hard protein corona in

  11. Respiration of bivalves from three different deep-sea areas: Cold seeps, hydrothermal vents and organic carbon-rich sediments

    Science.gov (United States)

    Khripounoff, A.; Caprais, J. C.; Decker, C.; Le Bruchec, J.; Noel, P.; Husson, B.

    2017-08-01

    We studied bivalves (vesicomyids and mytilids) inhabiting four different areas of high sulfide and methane production: (1) in the Gulf of Guinea, two pockmarks (650 m and 3150 m depth) and one site rich in organic sediments in the deepest zone (4950 m average depth), (2) at the Azores Triple Junction on the Mid-Atlantic Ridge, one hydrothermal site (Lucky Strike vent field, 1700 m depth). Two types of Calmar benthic chambers were deployed, either directly set into the sediment (standard Calmar chamber) or fitted with a tank to isolate organisms from the sediment (modified Calmar chamber), to assess gas and solute exchanges in relation to bivalve bed metabolism. Fluxes of oxygen, total carbon dioxide, ammonium and methane were measured. At the site with organic-rich sediments, oxygen consumption by clams measured in situ with the standard benthic chamber was variable (1.3-6.7 mmol m-2 h-1) as was total carbon dioxide production (1-9.6 mmol m-2 h-1). The observed gas and solute fluxes were attributed primarily to bivalve respiration (vesicomyids or mytilids), but microbial and geochemical processes in the sediment may be also responsible for some of variations in the deepest stations. The respiration rate of isolated vesicomyids (16.1-0.25.7 μmol g-1 dry weight h-1) was always lower than that of mytilids (33 μmol g-1 dry weight h-1). This difference was attributed to the presence of a commensal scaleworm in the mytilids. The respiratory coefficient (QR) ≥1 indicated high levels of anaerobic metabolism. The O:N index ranged from 5 to 25, confirming that vesicomyids and mytilids, living in symbiosis with bacteria, have a protein-based food diet.

  12. Immunomodulation by different types of N-oxides in the hemocytes of the marine bivalve Mytilus galloprovincialis.

    Directory of Open Access Journals (Sweden)

    Caterina Ciacci

    Full Text Available The potential toxicity of engineered nanoparticles (NPs for humans and the environment represents an emerging issue. Since the aquatic environment represents the ultimate sink for NP deposition, the development of suitable assays is needed to evaluate the potential impact of NPs on aquatic biota. The immune system is a sensitive target for NPs, and conservation of innate immunity represents an useful basis for studying common biological responses to NPs. Suspension-feeding invertebrates, such as bivalves, are particularly at risk to NP exposure, since they have extremely developed systems for uptake of nano and microscale particles integral to intracellular digestion and cellular immunity. Evaluation of the effects of NPs on functional parameters of bivalve immunocytes, the hemocytes, may help understanding the major toxic mechanisms and modes of actions that could be relevant for different NP types in aquatic organisms.In this work, a battery of assays was applied to the hemocytes of the marine bivalve Mytilus galloprovincialis to compare the in vitro effects of different n-oxides (n-TiO(2, n-SiO(2, n-ZnO, n-CeO(2 chosen on the basis of their commercial and environmental relevance. Physico-chemical characterization of both primary particles and NP suspensions in artificial sea water-ASW was performed. Hemocyte lysosomal and mitochondrial parameters, oxyradical and nitric oxide production, phagocytic activity, as well as NP uptake, were evaluated. The results show that different n-oxides rapidly elicited differential responses hemocytes in relation to their chemical properties, concentration, behavior in sea water, and interactions with subcellular compartments. These represent the most extensive data so far available on the effects of NPs in the cells of aquatic organisms. The results indicate that Mytilus hemocytes can be utilized as a suitable model for screening the potential effects of NPs in the cells of aquatic invertebrates, and may

  13. Bioacessibilidade in vitro das biotoxinas marinhas ácido ocadaico, dinofisistoxina-2 e seus derivados em bivalves crus e cozinhados

    OpenAIRE

    Manita, Diana Filipa Pereira

    2017-01-01

    Dissertação de Mestrado em Segurança Alimentar As biotoxinas marinhas mais frequentes e abundantes em Portugal são as toxinas lipofílicas, nomeadamente as toxinas do grupo do ácido ocadaico (AO), que inclui as dinofisistoxinas (DTX1 e DTX2) e os seus derivados (DTX3), responsáveis pela intoxicação diarreica (DSP diarrhetic shellfish poisoning). A investigação da presença, variabilidade e transformação de biotoxinas marinhas em moluscos bivalves é de elevada importância não só p...

  14. Uranium(VI) speciation: modelling, uncertainty and relevance to bioavailability models. Application to uranium uptake by the gills of a freshwater bivalve

    International Nuclear Information System (INIS)

    Denison, F.H.

    2004-07-01

    The effects of varying solution composition on the interactions between uranium(VI) and excised gills of the freshwater bivalve Corbicula fluminea have been investigated in well defined solution media. A significant reduction in the uptake of uranium was observed on increasing the concentrations of the uranium complexing ligands citrate and carbonate. Saturation kinetics as a function of uranium concentration at a pH value of 5.0 were observed, indicating that the uptake of uranium is a facilitated process, probably involving one or several trans-membrane transport systems. A relatively small change in the uptake of uranium was found as a function of pH (factor of ca. 2), despite the extremely large changes to the solution speciation of uranium within the range of pH investigated (5.0 - 7.5). A comprehensive review of the thermodynamic data relevant to the solution composition domain employed for this study was performed. Estimates of the uncertainties for the formation constants of aqueous uranium(VI) species were integrated into a thermodynamic database. A computer program was written to predict the equilibrium distribution of uranium(VI) in simple aqueous systems, using thermodynamic parameter mean-values. The program was extended to perform Monte Carlo and Quasi Monte Carlo uncertainty analyses, incorporating the thermodynamic database uncertainty estimates, to quantitatively predict the uncertainties inherent in predicting the solution speciation of uranium. The use of thermodynamic equilibrium modelling as a tool for interpreting the bioavailability of uranium(VI) was investigated. Observed uranium(VI) uptake behaviour was interpreted as a function of the predicted changes to the solution speciation of uranium. Different steady-state or pre-equilibrium approaches to modelling uranium uptake were tested. Alternative modelling approaches were also tested, considering the potential changes to membrane transport system activity or sorption characteristics on

  15. Challenges to the Application of δ15N measurements of the organic fraction of archaeological and fossil mollusk shells to assess paleoenvironmental change.

    Science.gov (United States)

    Andrus, C. F. T.

    2015-12-01

    Nitrogen isotope analysis of the organic fraction of mollusk shells is beginning to be applied to questions of past anthropogenic and natural environmental variation using samples from archaeological and fossil deposits. Fairly extensive proxy validation research has been conducted in the past decade, documenting the relationship between the δ15N of ambient particulate organic matter, mollusk soft tissues, and shell organic matrix. However, comparatively little research has addressed the potential effects of taphonomy and diagenesis on these proxy records. Assessing archaeological samples are especially complex in that humans may have transported and/or cooked shell prior to deposition. Shell δ15N data will be presented from modern and archaeological oyster (Crassostrea virginica) and clam shell (Mercenaria spp.) of various late Holocene ages and late Cretaceous Crassatellites vadosus shells. Archaeological shells show some loss of organic matter over time, yet some Cretaceous shells retain enough matrix to permit δ15N analysis. The Cretaceous samples required concentration of the remaining organic matrix by removing carbonate via acid pretreatment prior to EA-IRMS analysis, but modern and archaeological shells had sufficient organic matrix to permit analysis without acid pretreatment. The δ15N data from the archaeological shells do not display obvious alteration from the loss of organic matrix. The results of cooking experiments performed on modern oyster shells also indicate little alteration of δ15N values, unless the shell was heated to the point of disintegration. While these experiments indicate promise for the application of δ15N analysis of shell organic matter, the results are incomplete and lack ideal control over initial δ15N values in ancient samples used for comparisons. Future research, perhaps focused on compound-specific δ15N analysis and additional controlled experiments on moderns shells, may improve this assessment.

  16. Chemosymbiotic species from the Gulf of Cadiz (NE Atlantic: distribution, life styles and nutritional patterns

    Directory of Open Access Journals (Sweden)

    C. F. Rodrigues

    2013-04-01

    Full Text Available Previous work in the mud volcanoes from the Gulf of Cadiz (South Iberian Margin revealed a high number of chemosymbiotic species, namely bivalves and siboglinid polychaetes. In this study we give an overview of the distribution and life styles of these species in the Gulf of Cadiz, determine the role of autotrophic symbionts in the nutrition of selected species using stable isotope analyses (δ13C, δ15N and δ34S and investigate the intra-specific variation of isotope signatures within and between study sites. During our studies, we identified twenty siboglinidae and nine bivalve chemosymbiotic species living in fifteen mud volcanoes. Solemyid bivalves and tubeworms of the genus Siboglinum are widespread in the study area, whereas other species were found in a single mud volcano (e.g. "Bathymodiolus" mauritanicus or restricted to deeper mud volcanoes (e.g. Polybrachia sp., Lamelisabella denticulata. Species distribution suggests that different species may adjust their position within the sediment according to their particular needs, and to the intensity and variability of the chemical substrata supply. Tissue stable isotope signatures for selected species are in accordance with values found in other studies, with thiotrophy as the dominant nutritional pathway, and with methanotrophy and mixotrophy emerging as secondary strategies. The heterogeneity in terms of nutrient sources (expressed in the high variance of nitrogen and sulphur values and the ability to exploit different resources by the different species may explain the high diversity of chemosymbiotic species found in the Gulf of Cadiz. This study increases the knowledge on distributional patterns and resource partitioning of chemosymbiotic species and highlights how trophic fuelling varies on spatial scales with direct implications to seep assemblages and potentially to the biodiversity of continental margin.

  17. Alkylphenols and polycyclic aromatic hydrocarbons in bivalves from Comunidad Valenciana coastal waters; Alquilfenoles e hidrocarburos aromaticos policiclicos en bivalvos de las coastas de la comunidad Valenciana

    Energy Technology Data Exchange (ETDEWEB)

    Marti Ortega, N.; Aguado Garcia, D.; Bouzas Blanco, A.; Segovia Martinez, L.; Albargues Llamas, M.; Sevillano Cabeza, A.; Campins Falco, P.; Seco Torrecillas, A.; Ferrer Polo, J.

    2009-07-01

    This paper reports the results on alkylphenol and polycyclic aromatic hydrocarbons (PAH) pollution in mussels and cleans from Comunidad Valenciana coastal waters, in 2008. The significant presence of nonylphenol observed in both bivalves reflects an exposure to alkyl phenolic surfactants from the discharges of wastewater treatment plants that treat industrial and urban wastewaters, where the presence of alkylphenol polyethoxylated is common due to its extensive use (detergents, solubilizers...). The presence of low levels of PAH was observed in most of the studied areas. However, it must be highlighted that bivalves consumption does not imply any risk for human health. (Author) 21 refs.

  18. Distribution and density of the bivalve Anomalocardia brasiliana in the estuarine region of Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    A. M. L. Rodrigues Maia

    2017-06-01

    Full Text Available Abstract The objective of this study was to analyze the density and distribution of the bivalve Anomalocardia brasiliana in beaches in the estuarine region of the semiarid in Rio Grande do Norte State, Barra and Pernambuquinho (04°56.978’S and 37°08.961’W and 04°56.792’S and 37°09.375’W, respectively. Samples were collected monthly during 37 months using five transects (300 m long and 400 m apart laid perpendicularly to the beach line toward the sea. Seven collection points, 50 m apart, were set in each transect, and shellfish and sediment samples were collected. Temperature and salinity were measured in each transect. The results showed a temperature variation of average values of 3 °C; the greatest variation (33.2 °C was observed in May of 2009. The lowest average salinity values were observed between April and June of 2009 (5, 8.7, and 7.8, respectively. This fact was due to an atypical rainfall in the region, which resulted in a large freshwater inflow into the estuary; the average salinity values were about 40 in the remaining months. The highest precipitation values were observed in April/09, April/10, and April/11; the highest precipitation occurred in April/09 (316.3 mm. The lower average densities of A. brasiliana were observed in April and May/09 when compared to the other months; the lowest value was observed in April/09 (26 ind/m2. The highest densities occurred between November/10 and July/11, with values ranging from 70 to 322 ind/m2. The highest inflow of young individuals (lengths from 2 to 5 mm was observed between April and June of 2010 and on September/10 while the highest frequency of adults (from 20 to 25 mm occurred between December of 2010 and April of 2011. Hence, the results of this study show that in the months with the greatest rainfall, salinity and the average density of A. brasiliana showed the lowest values.

  19. Effect of the exposure to suspended solids on the enzymatic activity in the bivalve Sinonovacula constricta

    Directory of Open Access Journals (Sweden)

    Guojun Yang

    2017-01-01

    Full Text Available Aquatic animals are susceptible to sudden changes of their living environment but they adopt strategies to cope with adverse environmental challenges. Contamination by suspended solids, often associated with a dramatic change in the concentrations of important water-quality variables is a frequent occurrence in China's coastal waters and estuaries. Here we studied the impact of suspended solids on the activities of the antioxidant enzymes superoxide dismutase (SOD and catalase (CAT, as well as adenosine triphosphates (including Na+ K+-ATPase, Mg+ +-ATPase, Ca+ +-ATPase and H+ K+-ATPase in the gills and visceral mass tissues of the molluscan bivalve Sinonovacula constricta exposed (4, 8, 12, 16, 20, and 24 days to various concentrations of suspended solids. Our results showed that the antioxidant enzymes cooperated closely to effectively scavenge superoxide anion free radicals and H2O2 (which can ultimately inhibit gill activity through the modification of SOD and/or CAT enzymatic activities. ATPases activity (considered to be a sensitive indicator of toxicity could play an effective role in the maintenance of functional integrity of the plasma membranes as well as some other intracellular functions. After the exposure, a decrease in the Na+ K+-ATPase, Mg+ +-ATPase, and Ca+ +-ATPase activity of the gills was observed suggesting that they were inhibited by the treatments. These results also indicated that, from day 4 to day 16, exposure to high concentrations of suspended solids had an inhibitory effect on the activity of H+-K+-ATPase in the visceral mass of S. constricta. However, after a period of adaptation the H+-K+-ATPase activity was restored to original levels. Our results suggest that long-term exposure to high levels of suspended solids disturb osmoregulation, gastric acid secretion and digestion, cause oxidative damage, as a consequence of antioxidant enzymes inactivation which eventually damages the gills, affect the food intake

  20. 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.

  1. 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.)

  2. Evaluation of the threat of marine CO2 leakage-associated acidification on the toxicity of sediment metals to juvenile bivalves

    International Nuclear Information System (INIS)

    Basallote, M. Dolores; Rodríguez-Romero, Araceli; De Orte, Manoela R.; Del Valls, T. Ángel; Riba, Inmaculada

    2015-01-01

    Highlights: • Short-term tests using juveniles of bivalves to study the effects of CO 2 dissolved. • CO 2 causes effects if the threshold concentration of the organism is overlapped. • Flows of escaped CO 2 would affect the geochemical composition of sediment–seawater. • CO 2 -induced acidification would affect differently to marine sediment toxicity. - Abstract: The effects of the acidification associated with CO 2 leakage from sub-seabed geological storage was studied by the evaluation of the short-term effects of CO 2 -induced acidification on juveniles of the bivalve Ruditapes philippinarum. Laboratory scale experiments were performed using a CO 2 -bubbling system designed to conduct ecotoxicological assays. The organisms were exposed for 10 days to elutriates of sediments collected in different littoral areas that were subjected to various pH treatments (pH 7.1, 6.6, 6.1). The acute pH-associated effects on the bivalves were observed, and the dissolved metals in the elutriates were measured. The median toxic effect pH was calculated, which ranged from 6.33 to 6.45. The amount of dissolved Zn in the sediment elutriates increased in parallel with the pH reductions and was correlated with the proton concentrations. The pH, the pCO 2 and the dissolved metal concentrations (Zn and Fe) were linked with the mortality of the exposed bivalves

  3. Late Devonian (Frasnian) bivalves from the Nocedo Formation: the results of Wilhelm Kegel’s 1927 field trip to northern Spain

    NARCIS (Netherlands)

    Amler, M.R.W.

    2010-01-01

    During a field trip to the Peña-Corada Unit of the southernmost Esla region of the Cantabrian Mountains in 1927, the German stratigrapher Wilhelm Kegel sampled brachiopods and bivalves from a section in the Laoz valley near La Ercina. The stratigraphic position is believed to be part of the Nocedo

  4. Systematics, functional morphology and distribution of a bivalve (Apachecorbula muriatica gen. et sp. nov.) from the rim of the 'Valdivia Deep' brine pool in the Red Sea

    KAUST Repository

    Oliver, Pere Graham

    2014-11-11

    The deep brine pools of the Red Sea comprise extreme, inhospitable habitats yet house microbial communities that potentially may fuel adjacent fauna. We here describe a novel bivalve from a deep-sea (1525 m) brine pool in the Red Sea, where conditions of high salinity, lowered pH, partial anoxia and high temperatures are prevalent. Remotely operated vehicle (ROV) footage showed that the bivalves were present in a narrow (20 cm) band along the rim of the brine pool, suggesting that it is not only tolerant of such extreme conditions but is also limited to them. The bivalve is a member of the Corbulidae and named Apachecorbula muriatica gen. et sp. nov. The shell is atypical of the family in being modioliform and thin. The semi-infaunal habit is seen in ROV images and reflected in the anatomy by the lack of siphons. The ctenidia are large and typical of a suspension feeding bivalve, but the absence of \\'guard cilia\\' and the greatly reduced labial palps suggest that it is non-selective as a response to low food availability. It is proposed that the low body mass observed is a consequence of the extreme habitat and low food availability. It is postulated that the observed morphology of Apachecorbula is a result of paedomorphosis driven by the effects of the extreme environment on growth but is in part mitigated by the absence of high predation pressures. © Marine Biological Association of the United Kingdom, 2014.

  5. Subcellular partitioning of cadmium in the freshwater bivalve, Pyganodon grandis, after separate short-term exposures to waterborne or diet-borne metal

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Sophie; Hare, Landis [INRS-Eau, Terre et Environnement, Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada); Campbell, Peter G.C., E-mail: peter.campbell@ete.inrs.ca [INRS-Eau, Terre et Environnement, Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada)

    2010-11-15

    The dynamics of cadmium uptake and subcellular partitioning were studied in laboratory experiments conducted on Pyganodon grandis, a freshwater unionid bivalve that shows promise as a biomonitor for metal pollution. Bivalves were collected from an uncontaminated lake, allowed to acclimate to laboratory conditions ({>=}25 days), and then either exposed to a low, environmentally relevant, concentration of dissolved Cd (5 nM; 6, 12 and 24 h), or fed Cd-contaminated algae ({approx}70 nmol Cd g{sup -1} dry weight; 4 x 4 h). In this latter case, the bivalves were allowed to depurate for up to 8 days after the end of the feeding phase. As anticipated, the gills were the main target organ during the aqueous Cd exposure whereas the intestine was the initial site of Cd accumulation during the dietary exposure; during the subsequent depuration period, the dietary Cd accumulated in both the digestive gland and in the gills. For the gills, the distribution of Cd among the subcellular fractions (i.e., granules > heat-denatured proteins (HDP) {approx} heat-stable proteins (HSP) > mitochondria {approx} lysosomes + microsomes) was insensitive to the exposure route; both waterborne and diet-borne Cd ended up largely bound to the granule fraction. The subcellular distribution of Cd in the digestive gland differed markedly from that in the gills (HDP > HSP {approx} granules {approx} mitochondria > lysosomes + microsomes), but as in the case of the gills, this distribution was relatively insensitive to the exposure route. For both the gills and the digestive gland, the subcellular distributions of Cd differed from those observed in native bivalves that are chronically exposed to Cd in the field - in the short-term experimental exposures of P. grandis, metal detoxification was less effective than in chronically exposed native bivalves.

  6. Cephalic and limb anatomy of a new Isoxyid from the Burgess Shale and the role of "stem bivalved arthropods" in the disparity of the frontalmost appendage.

    Directory of Open Access Journals (Sweden)

    Cédric Aria

    Full Text Available We herein describe Surusicaris elegans gen. et sp. nov. (in Isoxyidae, amended, a middle (Series 3, Stage 5 Cambrian bivalved arthropod from the new Burgess Shale deposit of Marble Canyon (Kootenay National Park, British Columbia. Surusicaris exhibits 12 simple, partly undivided biramous trunk limbs with long tripartite caeca, which may illustrate a plesiomorphic "fused" condition of exopod and endopod. We construe also that the head is made of five somites (= four segments, including two eyes, one pair of anomalocaridid-like frontalmost appendages, and three pairs of poorly sclerotized uniramous limbs. This fossil may therefore be a candidate for illustrating the origin of the plesiomorphic head condition in euarthropods, and questions the significance of the "two-segmented head" in, e.g., fuxianhuiids. The frontalmost appendage in isoxyids is intriguingly disparate, bearing similarities with both dinocaridids and euarthropods. In order to evaluate the relative importance of bivalved arthropods, such as Surusicaris, in the hypothetical structuro-functional transition between the dinocaridid frontal appendage and the pre-oral-arguably deutocerebral-appendage of euarthropods, we chose a phenetic approach and computed morphospace occupancy for the frontalmost appendages of 36 stem and crown taxa. Results show different levels of evolutionary decoupling between frontalmost appendage disparity and body plans. Variance is greatest in dinocaridids and "stem bivalved" arthropods, but these groups do not occupy the morphospace homogeneously. Rather, the diversity of frontalmost appendages in "stem bivalved" arthropods, distinct in its absence of clear clustering, is found to link the morphologies of "short great appendages," chelicerae and antennules. This find fits the hypothesis of an increase in disparity of the deutocerebral appendage prior to its diversification in euarthropods, and possibly corresponds to its original time of development. The

  7. Cephalic and limb anatomy of a new Isoxyid from the Burgess Shale and the role of "stem bivalved arthropods" in the disparity of the frontalmost appendage.

    Science.gov (United States)

    Aria, Cédric; Caron, Jean-Bernard

    2015-01-01

    We herein describe Surusicaris elegans gen. et sp. nov. (in Isoxyidae, amended), a middle (Series 3, Stage 5) Cambrian bivalved arthropod from the new Burgess Shale deposit of Marble Canyon (Kootenay National Park, British Columbia). Surusicaris exhibits 12 simple, partly undivided biramous trunk limbs with long tripartite caeca, which may illustrate a plesiomorphic "fused" condition of exopod and endopod. We construe also that the head is made of five somites (= four segments), including two eyes, one pair of anomalocaridid-like frontalmost appendages, and three pairs of poorly sclerotized uniramous limbs. This fossil may therefore be a candidate for illustrating the origin of the plesiomorphic head condition in euarthropods, and questions the significance of the "two-segmented head" in, e.g., fuxianhuiids. The frontalmost appendage in isoxyids is intriguingly disparate, bearing similarities with both dinocaridids and euarthropods. In order to evaluate the relative importance of bivalved arthropods, such as Surusicaris, in the hypothetical structuro-functional transition between the dinocaridid frontal appendage and the pre-oral-arguably deutocerebral-appendage of euarthropods, we chose a phenetic approach and computed morphospace occupancy for the frontalmost appendages of 36 stem and crown taxa. Results show different levels of evolutionary decoupling between frontalmost appendage disparity and body plans. Variance is greatest in dinocaridids and "stem bivalved" arthropods, but these groups do not occupy the morphospace homogeneously. Rather, the diversity of frontalmost appendages in "stem bivalved" arthropods, distinct in its absence of clear clustering, is found to link the morphologies of "short great appendages," chelicerae and antennules. This find fits the hypothesis of an increase in disparity of the deutocerebral appendage prior to its diversification in euarthropods, and possibly corresponds to its original time of development. The analysis of this

  8. Macrophyte canopy structure and the success of an invasive marine bivalve

    NARCIS (Netherlands)

    Reusch, TBH; Williams, Susan L.

    In both terrestrial and aquatic environments introductions of non-indigenous species are continuing and represent one important component of global change. Negative biotic interactions by resident species may prevent successful invaders from becoming pests. Few experimental data are available on the

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

    Directory of Open Access Journals (Sweden)

    José R. B. de Souza

    2005-12-01

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

  10. Interactive effects of pH and metals on mitochondrial functions of intertidal bivalves Crassostrea virginica and Mercenaria mercenaria

    International Nuclear Information System (INIS)

    Ivanina, Anna V.; Sokolova, Inna M.

    2013-01-01

    Highlights: •Interactive effects of trace metals Cd and Cu and pH were studied in mitochondria of clams and oysters. •Mitochondrial respiration and membrane potential of bivalves were robust to pH variation (6.6–7.8). •Elevated levels of Cd and Cu inhibited mitochondrial respiration in the pH-dependent manner but did not affect the membrane potential. •Negative effects of Cd and Cd on mitochondrial respiration were alleviated at low pH (7.0 and below). •Moderate acidosis may protect molluscan mitochondria from metal toxicity. -- Abstract: Intertidal bivalves experience broad fluctuations of environmental temperature, pH and oxygen content which could change their intracellular pH. They are also exposed to trace metals such as cadmium (Cd) and copper (Cu) that accumulate in their tissues and may negatively affect mitochondrial functions and bioenergetics. We determined the interactive effects of pH and trace metals (25 μM Cd or Cu) on mitochondrial functions (including respiration and membrane potentials in both ADP-stimulated (state 3) and resting (state 4) states) of two common marine bivalves, the hard clams (Mercenaria mercenaria) and eastern oysters (Crassostrea virginica). In the absence of the trace metals, mitochondrial functions of C. virginica and M. mercenaria were insensitive to pH in a broad physiologically relevant range (6.6–7.8). Mitochondrial respiration was generally suppressed by 25 μM Cd or Cu (with the stronger effects observed for ADP-stimulated compared to the resting respiration) while the mitochondrial membrane potential was unaffected. pH modulated the effects of Cu and Cd on mitochondrial respiration of the bivalves. In oysters, Cu suppressed ADP-stimulated mitochondrial respiration at high and low pH values (6.6 and 7.8, respectively), but had no effect in the intermediate pH range (7.0–7.4). In clams, the negative effect of Cu on ADP-stimulated respiration was only observed at extremely high pH (7.8). A decrease in p

  11. Metals and pesticides in commercial bivalve mollusc production areas in the North and South Bays, Santa Catarina (Brazil).

    Science.gov (United States)

    de Souza, R V; Garbossa, L H P; Campos, C J A; Vianna, L F de N; Vanz, A; Rupp, G S

    2016-04-15

    Concentrations of heavy metals were quantified in mussels Perna perna and Pacific oysters Crassostrea gigas in 28 cultivation sites in the North and South Bays, SC (Brazil). Concentrations of pesticides were also quantified in these bivalve, water and sediment samples collected in 14 cultivation sites on four occasions in the period October 2012-October 2013. Pesticides were not detected in any of the mussel, oyster, water or sediment samples. The South Bay was found to be generally more contaminated with As while the North Bay showed higher concentrations of Ni. Concentrations of Pb and Cd were below the limit of detection of the method (0.5mg/kg) in all samples. Mussels accumulated more As and Ni than oysters, while the opposite was observed for Cu. Metal concentrations were below the maximum levels for foodstuffs specified in the Brazilian legislation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Interactive effects of pH and metals on mitochondrial functions of intertidal bivalves Crassostrea virginica and Mercenaria mercenaria

    Energy Technology Data Exchange (ETDEWEB)

    Ivanina, Anna V.; Sokolova, Inna M., E-mail: isokolov@uncc.edu

    2013-11-15

    Highlights: •Interactive effects of trace metals Cd and Cu and pH were studied in mitochondria of clams and oysters. •Mitochondrial respiration and membrane potential of bivalves were robust to pH variation (6.6–7.8). •Elevated levels of Cd and Cu inhibited mitochondrial respiration in the pH-dependent manner but did not affect the membrane potential. •Negative effects of Cd and Cd on mitochondrial respiration were alleviated at low pH (7.0 and below). •Moderate acidosis may protect molluscan mitochondria from metal toxicity. -- Abstract: Intertidal bivalves experience broad fluctuations of environmental temperature, pH and oxygen content which could change their intracellular pH. They are also exposed to trace metals such as cadmium (Cd) and copper (Cu) that accumulate in their tissues and may negatively affect mitochondrial functions and bioenergetics. We determined the interactive effects of pH and trace metals (25 μM Cd or Cu) on mitochondrial functions (including respiration and membrane potentials in both ADP-stimulated (state 3) and resting (state 4) states) of two common marine bivalves, the hard clams (Mercenaria mercenaria) and eastern oysters (Crassostrea virginica). In the absence of the trace metals, mitochondrial functions of C. virginica and M. mercenaria were insensitive to pH in a broad physiologically relevant range (6.6–7.8). Mitochondrial respiration was generally suppressed by 25 μM Cd or Cu (with the stronger effects observed for ADP-stimulated compared to the resting respiration) while the mitochondrial membrane potential was unaffected. pH modulated the effects of Cu and Cd on mitochondrial respiration of the bivalves. In oysters, Cu suppressed ADP-stimulated mitochondrial respiration at high and low pH values (6.6 and 7.8, respectively), but had no effect in the intermediate pH range (7.0–7.4). In clams, the negative effect of Cu on ADP-stimulated respiration was only observed at extremely high pH (7.8). A decrease in p

  13. The mismatch between bioaccumulation in field and laboratory environments: Interpreting the differences for metals in benthic bivalves

    International Nuclear Information System (INIS)

    Belzunce-Segarra, Maria J.; Simpson, Stuart L.; Amato, Elvio D.; Spadaro, David A.; Hamilton, Ian L.; Jarolimek, Chad V.; Jolley, Dianne F.

    2015-01-01

    Laboratory-based bioaccumulation and toxicity bioassays are frequently used to predict the ecological risk of contaminated sediments in the field. This study investigates the bioassay conditions most relevant to achieving environmentally relevant field exposures. An identical series of metal-contaminated marine sediments were deployed in the field and laboratory over 31 days. Changes in metal concentrations and partitioning in both sediments and waters were used to interpret differences in metal exposure and bioaccumulation to the benthic bivalve Tellina deltoidalis. Loss of resuspended sediments and deposition of suspended particulate matter from the overlying water resulted in the concentrations of Cu, Pb and Zn (major contaminants) becoming lower in the 1-cm surface layer of field-deployed sediments. Lower exchange rates of overlying waters in the laboratory resulted in higher dissolved metal exposures. The prediction of metal bioaccumulation by the bivalves in field and laboratory was improved by considering the metal partitioning within the surface sediments. - Highlights: • Particulate metals are the dominant metal exposure route in laboratory and field tests (87). • There is an over-representation of the dissolved metal exposure in the laboratory (81). • Laboratory bioassays result in higher bioaccumulation of major metals, Cu, Pb, Zn (82). • Differences in exposure must be considered for a proper sediment quality evaluation (83). • Traditional measurements are not sufficient to explain bioaccumulation results (79). - To improve the value of field- and laboratory-based sediment bioassays in ecological risk assessments, it is necessary to create exposure conditions that resemble those in the field

  14. Hypoxia and acidification have additive and synergistic negative effects on the growth, survival, and metamorphosis of early life stage bivalves.

    Science.gov (United States)

    Gobler, Christopher J; DePasquale, Elizabeth L; Griffith, Andrew W; Baumann, Hannes

    2014-01-01

    Low oxygen zones in coastal and open ocean ecosystems have expanded in recent decades, a trend that will accelerate with climatic warming. There is growing recognition that low oxygen regions of the ocean are also acidified, a condition that will intensify with rising levels of atmospheric CO2. Presently, however, the concurrent effects of low oxygen and acidification on marine organisms are largely unknown, as most prior studies of marine hypoxia have not considered pH levels. We experimentally assessed the consequences of hypoxic and acidified water for early life stage bivalves (bay scallops, Argopecten irradians, and hard clams, Mercenaria mercenaria), marine organisms of significant economic and ecological value and sensitive to climate change. In larval scallops, experimental and naturally-occurring acidification (pH, total scale  = 7.4-7.6) reduced survivorship (by >50%), low oxygen (30-50 µM) inhibited growth and metamorphosis (by >50%), and the two stressors combined produced additively negative outcomes. In early life stage clams, however, hypoxic waters led to 30% higher mortality, while acidified waters significantly reduced growth (by 60%). Later stage clams were resistant to hypoxia or acidification separately but experienced significantly (40%) reduced growth rates when exposed to both conditions simultaneously. Collectively, these findings demonstrate that the consequences of low oxygen and acidification for early life stage bivalves, and likely other marine organisms, are more severe than would be predicted by either individual stressor and thus must be considered together when assessing how ocean animals respond to these conditions both today and under future climate change scenarios.

  15. Validation of the flow-through chamber (FTC and steady-state (SS methods for clearance rate measurements in bivalves

    Directory of Open Access Journals (Sweden)

    Poul S. Larsen

    2011-09-01

    To obtain precise and reliable laboratory clearance rate (filtration rate measurements with the ‘flow-through chamber method’ (FTC the design must ensure that only inflow water reaches the bivalve's inhalant aperture and that exit flow is fully mixed. As earlier recommended these prerequisites can be checked by a plot of clearance rate (CR versus increasing through-flow (Fl to reach a plateau, which is the true CR, but we also recommend to plot percent particles cleared versus reciprocal through-flow where the plateau becomes the straight line CR/Fl, and we emphasize that the percent of particles cleared is in itself neither a criterion for valid CR measurement, nor an indicator of appropriate ‘chamber geometry’ as hitherto adapted in many studies. For the ‘steady-state method’ (SS, the design must ensure that inflow water becomes fully mixed with the bivalve's excurrent flow to establish a uniform chamber concentration prevailing at its incurrent flow and at the chamber outlet. These prerequisites can be checked by a plot of CR versus increasing Fl, which should give the true CR at all through-flows. Theoretically, the experimental uncertainty of CR for a given accuracy of concentration measurements depends on the percent reduction in particle concentration (100×P from inlet to outlet of the ideal ‘chamber geomety’. For FTC, it decreases with increasing values of P while for SS it first decreases but then increases again, suggesting the use of an intermediate value of P. In practice, the optimal value of P may depend on the given ‘chamber geometry’. The fundamental differences between the FTC and the SS methods and practical guidelines for their use are pointed out, and new data on CR for the blue mussel, Mytilus edulis, illustrate a design and use of the SS method which may be employed in e.g. long-term growth experiments at constant algal concentrations.

  16. Effects of metal contamination on the gene expression profile of two benthic species: Cerastoderma edule and Ruditapes philippinarum

    KAUST Repository

    Rodrigues, Raquel

    2017-08-14

    This study aimed to identify new biomarkers for metal exposure in two bivalve species. Suppressive Subtractive Hybridization (SSH) was employed to evaluate the transcriptomic response of Cerastoderma edule and Ruditapes philippinarum to metal pollution. Protein synthesis and catalytic activity were the most affected metabolic processes in C. edule and R. philippinarum, respectively. Also, different genes responded to the effect of contamination in each species. The different response observed in both species reinforces the importance of including more than one bioindicator species in risk assessment studies. These results provide the basis for new studies, which are necessary for further validation of the use of the identified genes as molecular biomarkers for metal exposure.

  17. Effects of metal contamination on the gene expression profile of two benthic species: Cerastoderma edule and Ruditapes philippinarum

    KAUST Repository

    Rodrigues, Raquel; Lourenç o, Joana; Pereira, Patrí cia; Carvalho, Susana; Mendo, Sonia

    2017-01-01

    This study aimed to identify new biomarkers for metal exposure in two bivalve species. Suppressive Subtractive Hybridization (SSH) was employed to evaluate the transcriptomic response of Cerastoderma edule and Ruditapes philippinarum to metal pollution. Protein synthesis and catalytic activity were the most affected metabolic processes in C. edule and R. philippinarum, respectively. Also, different genes responded to the effect of contamination in each species. The different response observed in both species reinforces the importance of including more than one bioindicator species in risk assessment studies. These results provide the basis for new studies, which are necessary for further validation of the use of the identified genes as molecular biomarkers for metal exposure.

  18. Uranium(VI) speciation: modelling, uncertainty and relevance to bioavailability models. Application to uranium uptake by the gills of a freshwater bivalve; Speciation de l'uranium(6), modelisation, incertitude et implication pour les modeles de biodisponibilite. Application a l'accumulation dans les branchies d'un bivalve d'eau douce

    Energy Technology Data Exchange (ETDEWEB)

    Denison, F.H

    2004-07-01

    The effects of varying solution composition on the interactions between uranium(VI) and excised gills of the freshwater bivalve Corbicula fluminea have been investigated in well defined solution media. A significant reduction in the uptake of uranium was observed on increasing the concentrations of the uranium complexing ligands citrate and carbonate. Saturation kinetics as a function of uranium concentration at a pH value of 5.0 were observed, indicating that the uptake of uranium is a facilitated process, probably involving one or several trans-membrane transport systems. A relatively small change in the uptake of uranium was found as a function of pH (factor of ca. 2), despite the extremely large changes to the solution speciation of uranium within the range of pH investigated (5.0 - 7.5). A comprehensive review of the thermodynamic data relevant to the solution composition domain employed for this study was performed. Estimates of the uncertainties for the formation constants of aqueous uranium(VI) species were integrated into a thermodynamic database. A computer program was written to predict the equilibrium distribution of uranium(VI) in simple aqueous systems, using thermodynamic parameter mean-values. The program was extended to perform Monte Carlo and Quasi Monte Carlo uncertainty analyses, incorporating the thermodynamic database uncertainty estimates, to quantitatively predict the uncertainties inherent in predicting the solution speciation of uranium. The use of thermodynamic equilibrium modelling as a tool for interpreting the bioavailability of uranium(VI) was investigated. Observed uranium(VI) uptake behaviour was interpreted as a function of the predicted changes to the solution speciation of uranium. Different steady-state or pre-equilibrium approaches to modelling uranium uptake were tested. Alternative modelling approaches were also tested, considering the potential changes to membrane transport system activity or sorption characteristics on

  19. Environmental control and control of the environment: the basis of longevity in bivalves.

    Science.gov (United States)

    Abele, Doris; Philipp, Eva

    2013-01-01

    Longevity and ageing are two sides of a coin, leaving the question open as to which one is the cause and which one the effect. At the individual level, the physiological rate of ageing determines the length of life (= individual longevity, as long as death results from old age and not from disease or other impacts). Individual longevity depends on the direct influence of environmental conditions with respect to nutrition, and the possibility for and timing of reproduction, as well as on the energetic costs animals invest in behavioural and physiological stress defence. All these environmental effectors influence hormonal and cellular signalling pathways that modify the individual physiological condition, the reproductive strategy, and the rate of ageing. At the species level, longevity (= maximum lifespan) is the result of an evolutionary process and, thus, largely determined by the species' behavioural and physiological adaptations to its ecological niche. Specifically, reproductive and breeding strategies have to be optimized in relation to local environmental conditions in different habitats. As a result of adaptive and evolutionary processes, species longevity is genetically underpinned, not necessarily by a few ageing genes, but by an evolutionary process that has hierarchically shaped and optimized species genomes to function in a specific niche or environmental system. Importantly, investigations and reviews attempting to unravel the mechanistic basis of the ageing process need to differentiate clearly between the evolutionary process shaping longevity at the species level and the regulatory mechanisms that alter the individual rate of ageing. Copyright © 2012 S. Karger AG, Basel.

  20. The Mitochondrial Genomes of the Nudibranch Mollusks, Melibe leonina and Tritonia diomedea, and Their Impact on Gastropod Phylogeny.

    Directory of Open Access Journals (Sweden)

    Joseph L Sevigny

    Full Text Available The phylogenetic relationships among certain groups of gastropods have remained unresolved in recent studies, especially in the diverse subclass Opisthobranchia, where nudibranchs have been poorly represented. Here we present the complete mitochondrial genomes of Melibe leonina and Tritonia diomedea (more recently named T. tetraquetra, two nudibranchs from the unrepresented Cladobranchia group, and report on the resulting phylogenetic analyses. Both genomes coded for the typical thirteen protein-coding genes, twenty-two transfer RNAs, and two ribosomal RNAs seen in other species. The twelve-nucleotide deletion previously reported for the cytochrome oxidase 1 gene in several other Melibe species was further clarified as three separate deletion events. These deletions were not present in any opisthobranchs examined in our study, including the newly sequenced M. leonina or T. diomedea, suggesting that these previously reported deletions may represent more recently divergent taxa. Analysis of the secondary structures for all twenty-two tRNAs of both M. leonina and T. diomedea indicated truncated d arms for the two serine tRNAs, as seen in some other heterobranchs. In addition, the serine 1 tRNA in T. diomedea contained an anticodon not yet reported in any other gastropod. For phylogenetic analysis, we used the thirteen protein-coding genes from the mitochondrial genomes of M. leonina, T. diomedea, and seventy-one other gastropods. Phylogenetic analyses were performed for both the class Gastropoda and the subclass Opisthobranchia. Both Bayesian and maximum likelihood analyses resulted in similar tree topologies. In the Opisthobranchia, the five orders represented in our study were monophyletic (Anaspidea, Cephalaspidea, Notaspidea, Nudibranchia, Sacoglossa. In Gastropoda, two of the three traditional subclasses, Opisthobranchia and Pulmonata, were not monophyletic. In contrast, four of the more recently named gastropod clades (Vetigastropoda

  1. The ecology of freshwater bivalves in the Lake Sapanca basin, Turkey

    Czech Academy of Sciences Publication Activity Database

    Ercan, E.; Gaygusuz, Ö.; Tarkan, A. S.; Reichard, Martin; Smith, C.

    2013-01-01

    Roč. 37, č. 6 (2013), s. 730-738 ISSN 1300-0179 R&D Projects: GA ČR GA13-05872S Institutional support: RVO:68081766 Keywords : Turkey * water quality * invasive species * age * growth Subject RIV: EH - Ecology, Behaviour Impact factor: 0.585, year: 2013

  2. Bivalve aquaculture transfers in Atlantic Europe. Part B: Environmental impacts of transfer activities

    NARCIS (Netherlands)

    Brenner, M.; Fraser, D.; Nieuwenhove, van K.; Kamermans, P.

    2014-01-01

    For centuries human populations have moved live shellfish around the world for consumption or aquaculture purposes; being relayed from their area of origin for growout or sale. This is in contrast to the inadvertent anthropogenic spreading of species via e.g. ballast waters. There are inherent risks

  3. Evaluation of the threat of marine CO{sub 2} leakage-associated acidification on the toxicity of sediment metals to juvenile bivalves

    Energy Technology Data Exchange (ETDEWEB)

    Basallote, M. Dolores, E-mail: dolores.basallote@uca.es [Cátedra UNESCO/UNITWIN WiCop, Departamento de Química-Física, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Polígono Río San Pedro s/n, 11510 Puerto Real, Cádiz (Spain); Rodríguez-Romero, Araceli [Departamento de Ecología y Gestión Costera, Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Río San Pedro, 11510 Puerto Real, Cádiz (Spain); De Orte, Manoela R.; Del Valls, T. Ángel; Riba, Inmaculada [Cátedra UNESCO/UNITWIN WiCop, Departamento de Química-Física, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Polígono Río San Pedro s/n, 11510 Puerto Real, Cádiz (Spain)

    2015-09-15

    Highlights: • Short-term tests using juveniles of bivalves to study the effects of CO{sub 2} dissolved. • CO{sub 2} causes effects if the threshold concentration of the organism is overlapped. • Flows of escaped CO{sub 2} would affect the geochemical composition of sediment–seawater. • CO{sub 2}-induced acidification would affect differently to marine sediment toxicity. - Abstract: The effects of the acidification associated with CO{sub 2} leakage from sub-seabed geological storage was studied by the evaluation of the short-term effects of CO{sub 2}-induced acidification on juveniles of the bivalve Ruditapes philippinarum. Laboratory scale experiments were performed using a CO{sub 2}-bubbling system designed to conduct ecotoxicological assays. The organisms were exposed for 10 days to elutriates of sediments collected in different littoral areas that were subjected to various pH treatments (pH 7.1, 6.6, 6.1). The acute pH-associated effects on the bivalves were observed, and the dissolved metals in the elutriates were measured. The median toxic effect pH was calculated, which ranged from 6.33 to 6.45. The amount of dissolved Zn in the sediment elutriates increased in parallel with the pH reductions and was correlated with the proton concentrations. The pH, the pCO{sub 2} and the dissolved metal concentrations (Zn and Fe) were linked with the mortality of the exposed bivalves.

  4. Endangered Species

    Science.gov (United States)

    EPA's Endangered Species Protection Program helps promote recovery of listed species. The ESPP determines if pesticide use in a geographic area may affect any listed species. Find needed limits on pesticide use in Endangered Species Protection Bulletins.

  5. PAH assessment in the main Brazilian offshore oil and gas production area using semi-permeable membrane devices (SPMD) and transplanted bivalves

    Science.gov (United States)

    André Lourenço, Rafael; Francisco de Oliveira, Fábio; Haddad Nudi, Adriana; Rebello Wagener, Ângela de Luca; Guadalupe Meniconi, Maria de Fátima; Francioni, Eleine

    2015-06-01

    The Campos Basin is Brazil's main oil and gas production area. In 2013, more than 50 million cubic meters of produced water (PW) was discharged into these offshore waters. Despite the large volumes of PW that are discharged in the Campos Basin each day, the ecological concern of the chemicals in the PW are not completely understood. Polycyclic aromatic hydrocarbons (PAH) are the most important contributors to the ecological hazards that are posed by discharged PW. This study aimed to evaluate the potential bioaccumulation of PAH using transplanted bivalves (Nodipecten nodosus) and semi-permeable membrane devices (SPMD). The study was conducted in two platforms that discharge PW (P19 and P40). Another platform that does not discharge PW (P25) was investigated for comparison with the obtained results. Time-integrated hydrocarbon concentrations using SPMD and transplanted bivalves were estimated from the seawater near the three platforms. The bioaccumulation of the PAH in the transplanted bivalves at platforms P19 and P40 were up to fivefold greater than the bioaccumulation of the PAH at platform P25. The lowest PAH concentrations were estimated for platform P25 (4.3-6.2 ng L-1), and the highest PAH concentrations were estimated for platform P19 (9.2-37.3 ng L-1). Both techniques were effective for determining the bioavailability of the PAH and for providing time-integrated hydrocarbon concentrations regarding oil and gas production activities.

  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. Larval habitat choice in still water and flume flows by the opportunistic bivalve Mulinia lateralis

    Science.gov (United States)

    Grassle, Judith P.; Snelgrove, Paul V. R.; Butman, Cheryl Ann

    Competent pediveligers of the coot clam Mulinia lateralis (Say) clearly preferred an organically-rich mud over abiotic glass beads in 24-h flume experiments, and often demonstrated the same choice in still-water experiments. We hypothesize that peediveligers with characteristic helical swimming paths above the bottom can exercise habitat choice in both still water nad flow, but that the limited swimming ambits of physiologically older periveligers require near-bottom flows to move the larvae between sediment patches so that they can exercise habitat choice. Although M. lateralis larvae are planktotrophic, their ability to delay metamorphosis in the absence of a preferred sediment cue is limited to about five days, a shorter time than the lecithotrophi larvae of the opportunistic polychaete species, Capitella spp. I and II. Field distributions of all three opportunistic species may result, at least in part, from active habitat selection for high-organic sediments by settling larvae.

  8. Phenoloxidase activity in larval and juvenile homogenates and adult plasma and haemocytes of bivalve molluscs.

    Science.gov (United States)

    Luna-González, Antonio; Maeda-Martínez, Alfonso N; Vargas-Albores, Francisco; Ascencio-Valle, Felipe; Robles-Mungaray, Miguel

    2003-10-01

    Phenoloxidase (PO) activity was studied in larval and juvenile homogenates and in the plasma and haemocytes of adult Crassostrea gigas, Argopecten ventricosus, Nodipecten subnodosus, and Atrina maura. Samples were tested for the presence of PO activity by incubation with the substrate L-3, 4-dihydroxyphenylalanine using trypsin, alpha-chymotrypsin, laminarin, lipopolysaccharides (LPS), and sodium dodecyl sulphate (SDS) to elicit activation of prophenoloxidase (proPO) system. PO activity was not detected in larval homogenate. In juvenile homogenate, PO activity was found only in C. gigas and N. subnodosus. PO activity was present in adult samples and was enhanced by elicitors in the plasma of all species tested, but in haemocyte lysate supernatant (HLS) of only N. subnodosus. Activation of proPO by laminarin was suppressed by a protease inhibitor cocktail (P-2714) in plasma and HLS of all species tested.

  9. 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.

  10. A shell-formation related carbonic anhydrase in Crassostrea gigas modulates intracellular calcium against CO2 exposure: Implication for impacts of ocean acidification on mollusk calcification.

    Science.gov (United States)

    Wang, Xiudan; Wang, Mengqiang; Jia, Zhihao; Song, Xiaorui; Wang, Lingling; Song, Linsheng

    2017-08-01

    Ocean acidification (OA) could decrease the shells and skeletons formation of mollusk by reducing the availability of carbonate ions at calcification sites. Carbonic anhydrases (CAs) convert CO 2 to HCO 3 - and play important roles in biomineralization process from invertebrate to vertebrate. In the present study, a CA (designated as CgCA) was identified and characterized in Pacific oyster C. gigas. The cDNA of CgCA was of 927bp encoding a predicted polypeptide of 308 amino acids with a signal peptide and a CA catalytic function domain. The mRNA transcripts of CgCA were constitutively expressed in all tested tissues with the highest levels in mantle and hemocytes. During the early development period, the mRNA transcripts of CgCA could be detected in all the stages with the highest level in D-veliger larvae. Elevated CO 2 increased the mRNA transcripts of CgCA in muscle, mantle, hepatopancreas, gill and hemocytes significantly (p<0.05) and induced the translocation of CgCA in hemocytes and mantle. Moreover, elevated CO 2 also caused the decrease of intracellular Ca 2+ in hemocytes (p<0.05). The inhibition of CA by acetazolamide and suppression of CgCA gene via RNA interference could increase the intracellular Ca 2+ in hemocytes (p<0.05). Besides, the decrease of intracellular Ca 2+ content caused by Ca 2+ reagent ionomycin could affect localization of CgCA in mantle tissue. The results indicated CgCA played essential roles in calcification and elevated CO 2 accelerated the mutual modulation between calcium and CgCA, implying reduced calcification rate and dissolved shells under OA. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Pearl mussels (Margaritifera marocana) in Morocco: Conservation status of the rarest bivalve in African fresh waters.

    Science.gov (United States)

    Sousa, Ronaldo; Varandas, Simone; Teixeira, Amílcar; Ghamizi, Mohamed; Froufe, Elsa; Lopes-Lima, Manuel

    2016-03-15

    Margaritifera marocana is one of the rarest freshwater mussel species (listed as critically endangered), and is endemic to Morocco. Despite its constrained distribution and low abundance, to date there are no quantitative studies addressing the conservation status of this species. Surveys were conducted in 36 sites along the Oum Er Rbia river basin (Rivers Derna, Laabid and Oum Er Rbia) to assess the distribution, abundance, population structure and genetic diversity of M. marocana. Just one specimen was found on River Oum Er Rbia and none on River Derna; however, a high abundance was found in the lower section of River Laabid (e.g., site Laabid 6 reached a mean density of 11.0 ± 6.8 ind.m(-2)). Contrary to earlier information, which reported an overall population size fewer than 250 individuals in a restricted area and no juvenile presence, this study showed that a much higher abundance exists in River Laabid alone. In addition, the species is present in more than 50 km of this river and is still recruiting since small specimens were found. Regarding genetic diversity, six of nine loci previously used in Margaritifera margaritifera were polymorphic and suitable in M. marocana. The spatial range contraction of this species is likely to be very recent, since no strong signature was detected by the molecular diversity indices. Information gathered in this study can be used as a reference to the present conservation status of M. marocana, and guide future research and management initiatives to better conserve it. We conclude discussing the potential major threats for the future survival of M. marocana and suggest some management measures (and research needs) that should be urgently applied. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Quantification of {sup 232}Th, {sup 234}U, {sup 235}U and {sup 238}U in river mollusks by magnetic sector mass spectrometry with inductively coupled plasma source (Icp-SFMS); Cuantificacion de {sup 232}Th, {sup 234}U, {sup 235}U y {sup 238}U en moluscos de rios por espectrometria de masas de sector magnetico con fuente de plasma acoplado inductivamente (ICP-SFMS)

    Energy Technology Data Exchange (ETDEWEB)

    Arevalo R, D. L.; Hernandez M, H.; Romero G, E. T.; Lara A, N. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Alfaro de la T, M. C., E-mail: arevalo0591@hotmail.com [Universidad Autonoma de San Luis Potosi, Dr. Salvador Nava s/n, Zona Universitaria, 78290 San Luis Potosi, SLP (Mexico)

    2016-09-15

    The present work deals with the methodology established for the quantification of {sup 232}Th, {sup 234}U, {sup 238}U and {sup 235}U in the shell of gastropod mollusks collected in the rivers Valles, Coy and Axtla of San Luis Potosi, Mexico, which belong to the Panuco River basin; these rivers have as main source of pollution the discharge of municipal sewage, waste from small industries, agricultural and cattle residues and from natural sources. Conventional methods for measuring radio-nuclides are confronted with certain conditions related to the requirement in measurement, basically in the characterization that is related to the concepts of precision and accuracy. The analysis of the gastropod mollusk shell was performed by the Icp-SFMS technique; the main advantages of this technique lie in the isotope quantification capacity, the high precision and the low limits of detection, in this study are very important because these elements are in concentrations between ppb and ppt. This technique allowed the analysis of the samples having a complex matrix by the presence CaCO{sub 3} minimizing the interferences thanks to the ionization efficiency of the Ar plasma. For the species Pachychilus monachus were found concentrations of {sup 232}Th of 0.16-5.37 μg/g and of total U of 0.101-4.081 μg/g being this species where the highest values of total U were found. For Thiara (melanoids) tuberculata the lowest values were found among the different species ({sup 232}Th 0.61-3.61 μg/g and total U 0.006-0.042 μg/g), for Pachychilus suturalis, values of {sup 232}Th of 0.58-6.4 μg/g and for Pachychilus sp. were found between 0.26-7.62 μg/g and for total U values between 0.28-3.33 μg/g. The method offers several advantages: speed, good precision, low values of quantification limits and high sensitivity in the measurement of radio-nuclides and heavy metals. (Author)

  13. Assessment of bioavailability of weathered oil residues using caged bivalves (Crassostrea gigas and Mytilus edulis) as indicator organisms

    International Nuclear Information System (INIS)

    Bleczinski, C.F.; Costa, H.J.; Rigatti, M.J.; Wong, M.C.; Boehm, P.D.

    1993-01-01

    In April 1988, an estimated 400,000 gallons of San Joaquin Valley crude oil spilled into Peyton Slough and subsequently into Suisun Bay from an oil refinery in Martinez, California. The crude oil initially impacted a number of ecologically sensitive environments including estuarine water, marsh grasses, marsh and shoreline sediment, and intertidal sediment. A four-year oil weathering study was performed to determine the concentrations of environmentally important compounds in the stranded oil, to monitor changes in these concentrations over time, and to assess the potential long-term impact of the spilled oil in these various environments. As a result of marked differences in the rate of weathering at the different sites, a bioaccumulation component was added to the original study design in order to assess the bioavailability of crude oil residues remaining four-years post spill. Caged bivalves (Crassostrea gigas and Mytilus edulis) were deployed at the three study sites as sentinel organisms and exposed for three months. Sediments and organism tissues were analyzed using gas chromatography/mass spectrometry for polynuclear aromatic hydrocarbon (PAH) assemblages characteristics of the spilled oil. Advanced hydrocarbon fingerprinting techniques (e.g., double ratio plots of characteristic alkyl PAHs) were used to match distributions in the organisms and in the study site sediments

  14. Feeding behavior of the invasive bivalve Limnoperna fortunei (Dunker, 1857 under exposure to toxic cyanobacteria Microcystis aeruginosa

    Directory of Open Access Journals (Sweden)

    V Gazulha

    Full Text Available The aim of this study was to test the effects of cyanobacteria toxicity on feeding behavior of the golden mussel Limnoperna fortunei. First, it was tested the hypothesis that L. fortunei preferentially graze on non-toxic phytoplankton and reject toxic cyanobacteria. Second, it was tested the hypothesis that toxic cyanobacteria negatively affect feeding and survival of L. fortunei. The present study is the first to evaluate the effects of toxic cyanobacteria on L. fortunei feeding and survival. In the short-term grazing, golden mussel filtration rates were evaluated in the presence of toxic and non-toxic strains of cyanobacteria Microcystis aeruginosa, and non-toxic phytoplankton Nitzschia palea. Highest filtration rates were registered when mussels fed on Nitzschia. Despite that, golden mussel expelled Nitzschia cells in large quantities and preferentially ingested Microcystis cells, both toxic and non-toxic strains. In the long-term grazing, mussels were exposed to toxic and non-toxic strains of Microcystis during 5 days. Filtration rates were not significantly different for toxic and non-toxic Microcystis throughout exposure period. The results have demonstrated cyanobacteria toxicity is not the main factor influencing L. fortunei feeding behavior. Survival of L. fortunei feeding on toxic cyanobacteria shows the potential of this invasive bivalve as a vector to the transference of cyanotoxins to higher trophic levels.

  15. A humidity sensitive two-dimensional tunable amorphous photonic structure in the outer layer of bivalve ligament from Sunset Siliqua

    International Nuclear Information System (INIS)

    Zhang, Weigang; Zhang, Gangsheng

    2015-01-01

    A humidity sensitive two-dimensional tunable amorphous photonic structure (2D TAPS) in the outer layer of bivalve ligament from Sunset Siliqua (OLLS) was reported in this paper. The structural color and microstructure of OLLS were investigated by reflection spectra and scanning electron microscopy, respectively. The results indicate that the reflection peak wavelength of the wet OLLS blue-shifts from 454 nm to 392 nm with the increasing of air drying time from 0 to 40 min, while the reflectivity decreases gradually and vanishes at last, relevant color changes from blue to black background color. The structural color in the OLLS is produced by a two-dimensional amorphous photonic structure consisting of aligned protein fibers, in which the diameter of protein fiber and the inter-fiber spacing are 101 ± 12 nm. Water can reversibly tune the reflection peak wavelength and reflectivity of this photonic structure, and the regulation achieved through dynamically tuning the interaction between inter-fiber spacing and average refractive index. - Highlights: • A humidity sensitive two-dimensional tunable amorphous photonic structure • Water can reversibly tune the reflection peak wavelength and reflectivity of this photonic structure. • This photonic structure may yield very useful template for artificial structures

  16. A humidity sensitive two-dimensional tunable amorphous photonic structure in the outer layer of bivalve ligament from Sunset Siliqua

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weigang, E-mail: abczwg15@163.com [College of Materials and Chemical Engineering, Chuzhou University, Chuzhou 239000 (China); Zhang, Gangsheng [College of Material Science and Technology, Guangxi University, Nanning 530004 (China)

    2015-07-01

    A humidity sensitive two-dimensional tunable amorphous photonic structure (2D TAPS) in the outer layer of bivalve ligament from Sunset Siliqua (OLLS) was reported in this paper. The structural color and microstructure of OLLS were investigated by reflection spectra and scanning electron microscopy, respectively. The results indicate that the reflection peak wavelength of the wet OLLS blue-shifts from 454 nm to 392 nm with the increasing of air drying time from 0 to 40 min, while the reflectivity decreases gradually and vanishes at last, relevant color changes from blue to black background color. The structural color in the OLLS is produced by a two-dimensional amorphous photonic structure consisting of aligned protein fibers, in which the diameter of protein fiber and the inter-fiber spacing are 101 ± 12 nm. Water can reversibly tune the reflection peak wavelength and reflectivity of this photonic structure, and the regulation achieved through dynamically tuning the interaction between inter-fiber spacing and average refractive index. - Highlights: • A humidity sensitive two-dimensional tunable amorphous photonic structure • Water can reversibly tune the reflection peak wavelength and reflectivity of this photonic structure. • This photonic structure may yield very useful template for artificial structures.

  17. Genotoxic and Cytotoxic Effects on the Immune Cells of the Freshwater Bivalve Dreissena polymorpha Exposed to the Environmental Neurotoxin BMAA.

    Science.gov (United States)

    Lepoutre, Alexandra; Milliote, Nadia; Bonnard, Marc; Palos-Ladeiro, Mélissa; Rioult, Damien; Bonnard, Isabelle; Bastien, Fanny; Faassen, Elisabeth; Geffard, Alain; Lance, Emilie

    2018-03-01

    The environmental neurotoxin β- N -Methylamino-l-alanine (BMAA) has been pointed out to be involved in human neurodegenerative diseases. This molecule is known to be bioaccumulated by bivalves. However, little data about its toxic effects on freshwater mussels is available, particularly on the hemolymphatic compartment and its hemocyte cells involved in various physiological processes such as immune defenses, digestion and excretion, tissue repair, and shell production. Here we exposed Dreissena polymorpha to dissolved BMAA, at the environmental concentration of 7.5 µg of /mussel/3 days, during 21 days followed by 14 days of depuration in clear water, with the objective of assessing the BMAA presence in the hemolymphatic compartment, as well as the impact of the hemocyte cells in terms of potential cytotoxicity, immunotoxicity, and genotoxiciy. Data showed that hemocytes were in contact with BMAA. The presence of BMAA in hemolymph did not induce significant effect on hemocytes phagocytosis activity. However, significant DNA damage on hemocytes occurred during the first week (days 3 and 8) of BMAA exposure, followed by an increase of hemocyte mortality after 2 weeks of exposure. Those effects might be an indirect consequence of the BMAA-induced oxidative stress in cells. However, DNA strand breaks and mortality did not persist during the entire exposure, despite the BMAA persistence in the hemolymph, suggesting potential induction of some DNA-repair mechanisms.

  18. A complete Holocene record of trematode-bivalve infection and implications for the response of parasitism to climate change.

    Science.gov (United States)

    Huntley, John Warren; Fürsich, Franz T; Alberti, Matthias; Hethke, Manja; Liu, Chunlian

    2014-12-23

    Increasing global temperature and sea-level rise have led to concern about expansions in the distribution and prevalence of complex-lifecycle parasites (CLPs). Indeed, numerous environmental variables can influence the infectivity and reproductive output of many pathogens. Digenean trematodes are CLPs with intermediate invertebrate and definitive vertebrate hosts. Global warming and sea level rise may affect these hosts to varying degrees, and the effect of increasing temperature on parasite prevalence has proven to be nonlinear and difficult to predict. Projecting the response of parasites to anthropogenic climate change is vital for human health, and a longer term perspective (10(4) y) offered by the subfossil record is necessary to complement the experimental and historical approaches of shorter temporal duration (10(-1) to 10(3) y). We demonstrate, using a high-resolution 9,600-y record of trematode parasite traces in bivalve hosts from the Holocene Pearl River Delta, that prevalence was significantly higher during the earliest stages of sea level rise, significantly lower during the maximum transgression, and statistically indistinguishable in the other stages of sea-level rise and delta progradation. This stratigraphic paleobiological pattern represents the only long-term high-resolution record of pathogen response to global change, is consistent with fossil and recent data from other marine basins, and is instructive regarding the future of disease. We predict an increase in trematode prevalence concurrent with anthropogenic warming and marine transgression, with negative implications for estuarine macrobenthos, marine fisheries, and human health.

  19. Prevalence of human pathogenic enteric viruses in bivalve molluscan shellfish and cultured shrimp in south west coast of India.

    Science.gov (United States)

    Umesha, Kanasinakatte R; Bhavani, Naniah C; Venugopal, Moleyur N; Karunasagar, Indrani; Krohne, Georg; Karunasagar, Iddya

    2008-03-20

    The prevalence of human enteric viruses in bivalve molluscan shellfish and shrimp collected off the south west coast of India was studied to assess the extent of fecal pollution of coastal environment. Out of 194 samples analyzed, 37% of oyster, 46% of clam and 15% of shrimp samples were positive for enteroviruses (EV). Adenoviruses (ADV) were detected in 17% of oyster and 27% of clam samples. However, other enteric viruses such as noroviruses (NoV) and hepatitis A virus (HAV) were not detected in any of the samples. High prevalence of EV and ADV was noticed between May to December. Thirty four percent of oyster and 49% of clam samples showed fecal coliform values higher than the limit. MS-2 phage was detected in 57% of oyster and 73% of clam samples. The presence of MS-2 phage and human enteric viruses showed association while fecal coliforms and enteric viruses showed no association. However, 17 samples, which were positive for enteric viruses (EV and ADV), were negative for MS-2 phage.

  20. Covarying Shell Growth Parameters and the Regulation of Shell Shape in Marine Bivalves: A Case Study on Tellinoidea

    Directory of Open Access Journals (Sweden)

    Jean Béguinot

    2014-01-01

    Full Text Available Specific parameters characterising shell shape may arguably have a significant role in the adaptation of bivalve molluscs to their particular environments. Yet, such functionally relevant shape parameters (shell outline elongation, dissymmetry, and ventral convexity are not those parameters that the animal may directly control. Rather than shell shape, the animal regulates shell growth. Accordingly, an alternative, growth-based description of shell-shape is best fitted to understand how the animal may control the achieved shell shape. The key point is, in practice, to bring out the link between those two alternative modes of shell-shape descriptions, that is, to derive the set of equations which connects the growth-based shell-shape parameters to the functionally relevant shell-shape parameters. Thus, a preliminary object of this note is to derive this set of equations as a tool for further investigations. A second object of this work is to provide an illustrative example of implementation of this tool. I report on an unexpected negative covariance between growth-based parameters and show how this covariance results in a severe limitation of the range of interspecific variability of the degree of ventral convexity of the shell outline within the superfamily Tellinoidea. Hypotheses are proposed regarding the constraints possibly at the origin of this limitation of interspecific variability.

  1. Genotoxic and Cytotoxic Effects on the Immune Cells of the Freshwater Bivalve Dreissena polymorpha Exposed to the Environmental Neurotoxin BMAA

    Directory of Open Access Journals (Sweden)

    Alexandra Lepoutre

    2018-03-01

    Full Text Available The environmental neurotoxin β-N-Methylamino-l-alanine (BMAA has been pointed out to be involved in human neurodegenerative diseases. This molecule is known to be bioaccumulated by bivalves. However, little data about its toxic effects on freshwater mussels is available, particularly on the hemolymphatic compartment and its hemocyte cells involved in various physiological processes such as immune defenses, digestion and excretion, tissue repair, and shell production. Here we exposed Dreissena polymorpha to dissolved BMAA, at the environmental concentration of 7.5 µg of /mussel/3 days, during 21 days followed by 14 days of depuration in clear water, with the objective of assessing the BMAA presence in the hemolymphatic compartment, as well as the impact of the hemocyte cells in terms of potential cytotoxicity, immunotoxicity, and genotoxiciy. Data showed that hemocytes were in contact with BMAA. The presence of BMAA in hemolymph did not induce significant effect on hemocytes phagocytosis activity. However, significant DNA damage on hemocytes occurred during the first week (days 3 and 8 of BMAA exposure, followed by an increase of hemocyte mortality after 2 weeks of exposure. Those effects might be an indirect consequence of the BMAA-induced oxidative stress in cells. However, DNA strand breaks and mortality did not persist during the entire exposure, despite the BMAA persistence in the hemolymph, suggesting potential induction of some DNA-repair mechanisms.

  2. New Typical Vector of Neurotoxin β-N-Methylamino-l-Alanine (BMAA in the Marine Benthic Ecosystem

    Directory of Open Access Journals (Sweden)

    Aifeng Li

    2016-11-01

    Full Text Available The neurotoxin β-N-methylamino-l-alanine (BMAA has been identified as an environmental factor triggering neurodegenerative diseases such as Amyotrophic Lateral Sclerosis (ALS and Alzheimer’s disease (AD. We investigated the possible vectors of BMAA and its isomers 2,4-diaminobutyric acid (DAB and N-2(aminoethylglycine (AEG in marine mollusks collected from the Chinese coast. Sixty-eight samples of marine mollusks were collected along the Chinese coast in 2016, and were analyzed by an HILIC-MS/MS (hydrophilic interaction liquid chromatography with tandem quadrupole mass spectrometer method without derivatization. BMAA was detected in a total of five samples from three species: Neverita didyma, Solen strictus, and Mytilus coruscus. The top three concentrations of free-form BMAA (0.99~3.97 μg·g−1 wet weight were detected in N. didyma. DAB was universally detected in most of the mollusk samples (53/68 with no species-specific or regional differences (0.051~2.65 μg·g−1 wet weight. No AEG was detected in any mollusk samples tested here. The results indicate that the gastropod N. didyma might be an important vector of the neurotoxin BMAA in the Chinese marine ecosystem. The neurotoxin DAB was universally present in marine bivalve and gastropod mollusks. Since N. didyma is consumed by humans, we suggest that the origin and risk of BMAA and DAB toxins in the marine ecosystem should be further investigated in the future.

  3. Pleurolucina from the western Atlantic and eastern Pacific Oceans: a new intertidal species from Curaçao with unusual shell microstructure (Mollusca, Bivalvia, Lucinidae

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    Emily A. Glover

    2016-09-01

    Full Text Available A new shallow water species of the lucinid bivalve Pleurolucina is described from Curaçao in the southern Caribbean Sea and compared with known species of the genus from the western Atlantic and eastern Pacific Oceans. Although confused with the Floridian species P. leucocyma, it is most similar to the eastern Pacific P. undata. As in all studied lucinids, the new species possesses symbiotic bacteria housed in the ctenidia. The shell microstructure is unusual with repeated and intercalated conchiolin layers that have sublayers of ‘tulip-shaped’ calcareous spherules. Predatory drillings by naticid gastropods frequently terminate at the conchiolin layers.

  4. Bivalve aquaculture transfers in Atlantic Europe. Part B: Environmental impacts of transfer activities

    DEFF Research Database (Denmark)

    Brenner, M.; Fraser, D.; Van Nieuwenhove, K.

    2014-01-01

    For centuries human populations have moved live shellfish around the world for consumption or aquaculture purposes; being relayed from their area of origin for growout or sale. This is in contrast to the inadvertent anthropogenic spreading of species via e.g. ballast waters. There are inherent...... designed to minimise the impact on ecosystems worldwide. In a companion paper details of actual transfer activities in Atlantic Europe are presented and all levels of legislation dealing with transfer activities on a global, regional and national scale are carefully reviewed....

  5. Structure of sperm, spermatozeugmata and 'lateral organs' in the bivalve Arthritica (Galeommatoidea: Leptonidae)

    DEFF Research Database (Denmark)

    Jespersen, Åse; Lützen, Jørgen

    2009-01-01

    The position and structure of paired 'lateral organs' in the foot of Arthritica semen and Arthritica bifurca might indicate a chemosensory function. In both species part of the organ is also glandular. In A. semen the glandular epithelium is detached piecemeal and, probably by means of the foot...... chamber, which serves as a marsupium, but its function is uncertain. Arthritica semen is a protandric hermaphrodite and produces very large ova that undergo a direct development that results in a non-planktonic lecithotrophic crawling juvenile stage. The sperm cells have filiform nuclei that are straight...

  6. Metabolic Energy Demand Is Not Increased during Initial Shell Formation of Bivalves Exposed to Aragonite Undersaturation

    Science.gov (United States)

    Pan, F.; Frieder, C.; Applebaum, S.; Manahan, D. T.

    2016-02-01

    The Pacific oyster, Crassostrea gigas, is a major commercial species in global aquaculture. Ocean acidification is having a negative effect on larval production of this species, so the mechanisms of this impact are of considerable interest. Formation of new shell in C. gigas during the first 2-days post-fertilization results in a rapid six-fold increase in total mass. This period of early development has high sensitivity to changes in carbonate chemistry, in particular aragonite saturation state (Ω). An elevated energy cost for calcification at low Ω is often invoked as a mechanism. In this study, we characterized the developmental progression of first shell formation, total metabolic expenditure, and underlying biochemical processes of energy allocation during early development of C. gigas, under control (Ω >> 1) and undersaturated conditions (Ω pump activity (Na+, K+-ATPase) between the two treatments. We conclude that early development to the shelled-veliger larval stage does not require more energy at undersaturation. This finding helps constrain potential mechanisms of larval sensitivity to ocean acidification and narrows the focus for possible mitigation strategies for oyster aquaculture production.

  7. Influence of a step-change in metal exposure (Cd, Cu, Zn) on metal accumulation and subcellular partitioning in a freshwater bivalve, Pyganodon grandis: A long-term transplantation experiment between lakes with contrasting ambient metal levels

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Sophie [INRS-Eau, Terre et Environnement, Université du Québec, 490 de la Couronne, Québec, QC G1K 9A9 (Canada); Bonneris, Emmanuelle [INRS-Eau, Terre et Environnement, Université du Québec, 490 de la Couronne, Québec, QC G1K 9A9 (Canada) and Bayer S.A.S., Bayer CropScience, 16 Rue Jean-Marie Leclair, CP 90106, F 69266 Lyon Cedex 09 (France); Michaud, Annick [INRS-Eau, Terre et Environnement, Université du Québec, 490 de la Couronne, Québec, QC G1K 9A9 (Canada) and Direction des Évaluations environnementales, Ministère du Développement durable, de l’Environnement et des Parcs, 675, boul. René-Lévesque Est, 6e étage, Québec, QC G1R 5V7 (Canada); Pinel-Alloul, Bernadette [Groupe de Recherche Interuniversitaire en Limnologie et Environnement Aquatique (GRIL), Département de Sciences Biologiques, Université de Montréal, C.P. 6128, Montréal, QC H3C 3J7 (Canada); Campbell, Peter G.C., E-mail: peter.campbell@ete.inrs.ca [INRS-Eau, Terre et Environnement, Université du Québec, 490 de la Couronne, Québec, QC G1K 9A9 (Canada)

    2013-05-15

    Highlights: ? We transferred freshwater bivalves from a reference lake to a Cd and Zn contaminated lake. ? Changes in metal accumulation and subcellular partitioning were followed over time (up to 860 d). ? Metal detoxification strategies differed between target organs (gills vs. digestive gland). ? The ability to handle Cd is inherent in P. grandis, not a trait acquired after long-term adaptation. -- Abstract: The objective of the present field experiment was to identify detoxification responses in the gills and digestive gland of a freshwater unionid bivalve, Pyganodon grandis, subjected to a step-change in metal exposure. Adult bivalves were transferred from a reference site (Lake Opasatica) and a metal-contaminated lake (Lake Héva) to a second contaminated lake (Lake Vaudray) in northwestern Quebec, Canada. Changes in organ metal concentrations, in the subcellular distribution of metals and in metallothionein concentrations were followed over time (t = 0, 132, (400) and 860 days). At each collection time and for each bivalve, the gills and digestive gland were excised and gently homogenized; six sub-cellular fractions were separated by differential centrifugation and analyzed for their Cd, Cu and Zn content, and metallothionein was quantified independently. Metal detoxification strategies were shown to differ between target organs: in the gills, incoming metals were sequestered largely in the granules, whereas in the digestive gland the same metals primarily accumulated in the cytosol, in the metallothionein-like protein fraction. These metal-handling strategies, as employed by the metal-naïve bivalves originating in the reference lake, closely resemble those identified in free-living P. grandis chronically exposed in the metal-contaminated lake, suggesting that the ability to handle incoming metals (Cd in particular) is inherent in P. grandis and is not a trait acquired after long-term adaptation of the bivalve to metal-contaminated environments. The

  8. Spatial distribution modelling of the endangered bivalve Pinna nobilis in a Marine Protected Area

    Directory of Open Access Journals (Sweden)

    M. VÁZQUEZ-LUIS

    2014-09-01

    Full Text Available The spatial distribution of Pinna nobilis densities have been analysed through a geostatistical approach in the MPA of Cabrera National Park, Balearic Islands (Spain, Western Mediterranean Sea. Regression kriging was used to model the effect of environmental variables on the density of living individuals of P. nobilis and generate a predictive map of its distribution within the MPA. The environmental variables considered for the model were: depth; slope; habitat type and heterogeneity; wave exposure; and MPA zoning. A total of 378 transects were randomly distributed with a total of 149,000 m2 surveyed at a depth range from 4.2 to 46 m. The recorded P. nobilis densities are among the highest in the Mediterranean Sea. With respect to the prediction model, results indicate that benthic habitats play a key role in the spatial distribution of P. nobilis, with higher densities in seagrass meadows of Posidonia oceanica. The fan mussel population density peaked at 9 m depth, decreasing with depth. Also, decreasing densities are expected with increasing exposure to waves. The predicted map shows some hotspots of density different in size and distributed along the MPA, and provides valuable information for the spatial conservation management of this species.

  9. Sulfur contents and sulfur-isotope compositions of thiotrophic symbioses in bivalve molluscs and vestimentiferan worms

    Science.gov (United States)

    Vetter, R.D.; Fry, B.

    1998-01-01

    Total sulfur (S(TOT)), elemental sulfur (S??) and sulfur-isotope compositions (??34S) of marine animals were analyzed to determine whether these chemical characteristics could help distinguish animals with a sulfur-based, thiotrophic nutrition from animals whose nutrition is based on methanotrophy or on more normal consumption of phytoplankton-derived organic matter. The presence of S??was almost entirely confined to the symbiont-containing tissues of thiotrophs, but was sometimes undetectable in thiotrophic species where sulfide availability was probably low. When S??contents were subtracted, the remaining tissue-sulfur concentrations were similar for all nutritional groups. ??34S values were typically lower for thiotrophs than for other groups, although there was overlap in methanotroph and thiotroph values at some sites. Field evidence supported the existence of small to moderate (1 to 10???)34S fractionations in the uptake of sulfides and metabolism of thiosulfate. In general, a total sulfur content of >3% dry weight, the presence of elemental sulfur, and ??34S values less than + 5??? can be used to infer a thiotrophic mode of nutrition.

  10. Calcification in a marginal sea – influence of seawater [Ca2+] and carbonate chemistry on bivalve shell formation

    Directory of Open Access Journals (Sweden)

    J. Thomsen

    2018-03-01

    Full Text Available In estuarine coastal systems such as the Baltic Sea, mussels suffer from low salinity which limits their distribution. Anthropogenic climate change is expected to cause further desalination which will lead to local extinctions of mussels in the low saline areas. It is commonly accepted that mussel distribution is limited by osmotic stress. However, along the salinity gradient, environmental conditions for biomineralization are successively becoming more adverse as a result of reduced [Ca2+] and dissolved inorganic carbon (CT availability. In larvae, calcification is an essential process starting during early development with formation of the prodissoconch I (PD I shell, which is completed under optimal conditions within 2 days. Experimental manipulations of seawater [Ca2+] start to impair PD I formation in Mytilus larvae at concentrations below 3 mM, which corresponds to conditions present in the Baltic at salinities below 8 g kg−1. In addition, lowering dissolved inorganic carbon to critical concentrations (< 1 mM similarly affected PD I size, which was well correlated with calculated ΩAragonite and [Ca2+][HCO3−] ∕ [H+] in all treatments. Comparing results for larvae from the western Baltic with a population from the central Baltic revealed a significantly higher tolerance of PD I formation to lowered [Ca2+] and [Ca2+][HCO3−] ∕ [H+] in the low saline adapted population. This may result from genetic adaptation to the more adverse environmental conditions prevailing in the low saline areas of the Baltic. The combined effects of lowered [Ca2+] and adverse carbonate chemistry represent major limiting factors for bivalve calcification and can thereby contribute to distribution limits of mussels in the Baltic Sea.

  11. Calcification in a marginal sea - influence of seawater [Ca2+] and carbonate chemistry on bivalve shell formation

    Science.gov (United States)

    Thomsen, Jörn; Ramesh, Kirti; Sanders, Trystan; Bleich, Markus; Melzner, Frank

    2018-03-01

    In estuarine coastal systems such as the Baltic Sea, mussels suffer from low salinity which limits their distribution. Anthropogenic climate change is expected to cause further desalination which will lead to local extinctions of mussels in the low saline areas. It is commonly accepted that mussel distribution is limited by osmotic stress. However, along the salinity gradient, environmental conditions for biomineralization are successively becoming more adverse as a result of reduced [Ca2+] and dissolved inorganic carbon (CT) availability. In larvae, calcification is an essential process starting during early development with formation of the prodissoconch I (PD I) shell, which is completed under optimal conditions within 2 days. Experimental manipulations of seawater [Ca2+] start to impair PD I formation in Mytilus larvae at concentrations below 3 mM, which corresponds to conditions present in the Baltic at salinities below 8 g kg-1. In addition, lowering dissolved inorganic carbon to critical concentrations (< 1 mM) similarly affected PD I size, which was well correlated with calculated ΩAragonite and [Ca2+][HCO3-] / [H+] in all treatments. Comparing results for larvae from the western Baltic with a population from the central Baltic revealed a significantly higher tolerance of PD I formation to lowered [Ca2+] and [Ca2+][HCO3-] / [H+] in the low saline adapted population. This may result from genetic adaptation to the more adverse environmental conditions prevailing in the low saline areas of the Baltic. The combined effects of lowered [Ca2+] and adverse carbonate chemistry represent major limiting factors for bivalve calcification and can thereby contribute to distribution limits of mussels in the Baltic Sea.

  12. Effects of cadmium on anaerobic energy metabolism and mRNA expression during air exposure and recovery of an intertidal mollusk Crassostrea virginica

    International Nuclear Information System (INIS)

    Ivanina, Anna V.; Sokolov, Eugene P.; Sokolova, Inna M.

    2010-01-01

    Marine organisms are exposed to periodical oxygen deficiency and pollution stress in estuarine and coastal zones which may strongly affect their performance and survival. We studied the combined effects of exposure to a common pollutant, cadmium (Cd), and intermittent anoxia on anaerobic metabolism, energy status and mRNA expression of 13 genes involved in and/or controlled by the hypoxia inducible factor-1 (HIF-1) pathway in hepatopancreas of an intertidal bivalve, the eastern oyster Crassostrea virginica. In control oysters, prolonged anoxia resulted in a selective suppression of nitric oxide synthase (NOS) and upregulation of cytochrome c oxidase subunit IV (COX4) while the levels of other transcripts remained unchanged. During post-anoxic recovery, mRNA expression of hypoxia inducible factor-1α (HIF-1α) was elevated, phosphoenolpyruvate carboxykinase (PEPCK), NOS and LON protease suppressed, and mRNA expression of other studied genes not changed. Notably, most of the key glycolytic genes that are stimulated by HIF-1 in mammals, either remained unchanged or were downregulated in anoxic oysters suggesting a different mechanism of molecular response to oxygen deficiency. Patterns of transcriptional response during anoxia and reoxygenation were significantly altered by Cd exposure in a gene-specific manner. Anaerobic metabolism (indicated by accumulation of L-alanine, succinate and acetate during anoxia) was also suppressed in Cd-exposed oysters. In control oysters, ATP turnover rate (M ATP ) during anoxia was mostly sustained by anaerobic glycolysis with negligible contributions from ATP and PLA breakdown. In contrast, in Cd-exposed oysters ATP breakdown contributed significantly to anaerobic M ATP . Thus, while control oysters could efficiently defend the ATP levels and tissue energy status during prolonged anoxia, Cd-exposed oysters experienced a disturbance in tissue energy balance indicated by the depletion of ATP, a rapid decline in adenylate energy charge

  13. Effects of cadmium on anaerobic energy metabolism and mRNA expression during air exposure and recovery of an intertidal mollusk Crassostrea virginica

    Energy Technology Data Exchange (ETDEWEB)

    Ivanina, Anna V. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Sokolov, Eugene P. [Department of General Surgery, Carolina' s Medical Center, 1000 Blythe Blvd., Charlotte, NC 28203-5871 (United States); Sokolova, Inna M., E-mail: isokolov@uncc.edu [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)

    2010-09-01

    Marine organisms are exposed to periodical oxygen deficiency and pollution stress in estuarine and coastal zones which may strongly affect their performance and survival. We studied the combined effects of exposure to a common pollutant, cadmium (Cd), and intermittent anoxia on anaerobic metabolism, energy status and mRNA expression of 13 genes involved in and/or controlled by the hypoxia inducible factor-1 (HIF-1) pathway in hepatopancreas of an intertidal bivalve, the eastern oyster Crassostrea virginica. In control oysters, prolonged anoxia resulted in a selective suppression of nitric oxide synthase (NOS) and upregulation of cytochrome c oxidase subunit IV (COX4) while the levels of other transcripts remained unchanged. During post-anoxic recovery, mRNA expression of hypoxia inducible factor-1{alpha} (HIF-1{alpha}) was elevated, phosphoenolpyruvate carboxykinase (PEPCK), NOS and LON protease suppressed, and mRNA expression of other studied genes not changed. Notably, most of the key glycolytic genes that are stimulated by HIF-1 in mammals, either remained unchanged or were downregulated in anoxic oysters suggesting a different mechanism of molecular response to oxygen deficiency. Patterns of transcriptional response during anoxia and reoxygenation were significantly altered by Cd exposure in a gene-specific manner. Anaerobic metabolism (indicated by accumulation of L-alanine, succinate and acetate during anoxia) was also suppressed in Cd-exposed oysters. In control oysters, ATP turnover rate (M{sub ATP}) during anoxia was mostly sustained by anaerobic glycolysis with negligible contributions from ATP and PLA breakdown. In contrast, in Cd-exposed oysters ATP breakdown contributed significantly to anaerobic M{sub ATP}. Thus, while control oysters could efficiently defend the ATP levels and tissue energy status during prolonged anoxia, Cd-exposed oysters experienced a disturbance in tissue energy balance indicated by the depletion of ATP, a rapid decline in

  14. Temporal variability of the bivalve Erodona mactroides BOSC, 1802 during and after the El Niño phenomenon (2002/2003 in a subtropical lagoon, southern Brazil Variabilidade temporal do bivalve Erodona mactroides BOSC, 1802 durante e após o fenômeno El Niño (2002/2003 em uma laguna subtropical, sul do Brasil

    Directory of Open Access Journals (Sweden)

    Leonir André Colling

    2010-12-01

    Full Text Available AIM: The aim of this work was to study the relationships between temporal variability of Erodona mactroides and abiotic parameters of the water column and the substrate in a shallow embayment of the Patos Lagoon estuarine region in southern Brazil; METHODS: Samples were taken with a PVC corer (10 cm diameter buried 10 cm into the sediment between October 2002 and December 2004. Each month 18 biologic samples were taken, six substrate samples were analyzed for sediment grain size and organic matter content and sediment deposition rates were determined by 12 sediment traps every two weeks. Salinity, water temperature, water level and estuarine freshwater discharge were measured daily. Abiotic parameters and bivalve densities were tested among months with registered mortality events by ANOVA (One-way, p = 0.05, being the E. mactroides seasonal variability tested by Kruskal-Wallis (p = 0.05. Regression analyses among abiotic parameters and Spearman's "R" correlation analyses between biological and environmental data were both performed; RESULTS: Two periods were identified with distinct features: one at the beginning of the study when observed limnetic conditions in the estuarine region were caused by the ENSO - El Niño 2002/2003 phenomenon when an absence of E. mactroides was registered as well as a higher percentages of fine sediments and lower percentages of organic matter. The second period was characterized by a decreasing influence of the El Niño and predominance of mixohaline conditions, recruitments and increasing densities of E. mactroides with a successive decrease of mean densities due to three mortality events, lower percentages of fine sediments and higher percentages of organic matter; CONCLUSIONS: The present study provides evidences that the occurrence of E. mactroides in the southern estuarine region depends on the water flow regime from the drainage basin, which characterizes species recruitment as temporally unpredictable and

  15. Conservation genetics of a critically endangered limpet genus and rediscovery of an extinct species.

    Directory of Open Access Journals (Sweden)

    Diarmaid Ó Foighil

    Full Text Available A third of all known freshwater mollusk extinctions worldwide have occurred within a single medium-sized American drainage. The Mobile River Basin (MRB of Alabama, a global hotspot of temperate freshwater biodiversity, was intensively industrialized during the 20(th century, driving 47 of its 139 endemic mollusk species to extinction. These include the ancylinid limpet Rhodacmea filosa, currently classified as extinct (IUCN Red List, a member of a critically endangered southeastern North American genus reduced to a single known extant population (of R. elatior in the MRB.We document here the tripling of known extant populations of this North American limpet genus with the rediscovery of enduring Rhodacmea filosa in a MRB tributary and of R. elatior in its type locality: the Green River, Kentucky, an Ohio River Basin (ORB tributary. Rhodacmea species are diagnosed using untested conchological traits and we reassessed their systematic and conservation status across both basins using morphometric and genetic characters. Our data corroborated the taxonomic validity of Rhodacmea filosa and we inferred a within-MRB cladogenic origin from a common ancestor bearing the R. elatior shell phenotype. The geographically-isolated MRB and ORB R. elatior populations formed a cryptic species complex: although overlapping morphometrically, they exhibited a pronounced phylogenetic disjunction that greatly exceeded that of within-MRB R. elatior and R. filosa sister species.Rhodacmea filosa, the type species of the genus, is not extinct. It persists in a Coosa River tributary and morphometric and phylogenetic analyses confirm its taxonomic validity. All three surviving populations of the genus Rhodacmea merit specific status. They collectively contain all known survivors of a phylogenetically highly distinctive North American endemic genus and therefore represent a concentrated fraction of continental freshwater gastropod biodiversity. We recommend the establishment

  16. Interactions of cationic polystyrene nanoparticles with marine bivalve hemocytes in a physiological environment: Role of soluble hemolymph proteins.

    Science.gov (United States)

    Canesi, Laura; Ciacci, Caterina; Fabbri, Rita; Balbi, Teresa; Salis, Annalisa; Damonte, Gianluca; Cortese, Katia; Caratto, Valentina; Monopoli, Marco P; Dawson, Kenneth; Bergami, Elisa; Corsi, Ilaria

    2016-10-01

    The bivalve Mytilus galloprovincialis has proven as a suitable model invertebrate for evaluating the potential impact of nanoparticles (NPs) in the marine environment. In particular, in mussels, the immune system represents a sensitive target for different types of NPs. In environmental conditions, both NP intrinsic properties and those of the receiving medium will affect particle behavior and consequent bioavailability/uptake/toxicity. However, the evaluation of the biological effects of NPs requires additional understanding of how, once within the organism, NPs interact at the molecular level with cells in a physiological environment. In mammalian systems, different NPs associate with serum soluble components, organized into a "protein corona", which affects particle interactions with target cells. However, no information is available so far on the interactions of NPs with biological fluids of aquatic organisms. In this work, the influence of hemolymph serum (HS) on the in vitro effects of amino modified polystyrene NPs (PS-NH2) on Mytilus hemocytes was investigated. Hemocytes were incubated with PS-NH2 suspensions in HS (1, 5 and 50µg/mL) and the results were compared with those obtained in ASW medium. Cell functional parameters (lysosomal membrane stability, oxyradical production, phagocytosis) were evaluated, and morphological changes were investigated by TEM. The activation state of the signalling components involved in Mytilus immune response (p38 MAPK and PKC) was determined. The results show that in the presence of HS, PS-NH2 increased cellular damage and ROS production with respect to ASW medium. The effects were apparently mediated by disregulation of p38 MAPK signalling. The formation of a PS-NH2-protein corona in HS was investigated by centrifugation, and 1D- gel electrophoresis and nano-HPLC-ESI-MS/MS. The results identified the Putative C1q domain containing protein (MgC1q6) as the only component of the PS-NH2 hard protein corona in Mytilus

  17. Scientific opinion on the risks for public health related to the presence of tetrodotoxin (TTX) and TTX analogues in marine bivalves and gastropods

    DEFF Research Database (Denmark)

    Petersen, Annette

    Tetrodotoxin (TTX) and its analogues are produced by marine bacteria and have been detected in marine bivalves and gastropods from European waters. The European Commission asked EFSA for a scientific opinion on the risks to public health related to the presence of TTX and TTX analogues in marine...... bivalves and gastropods. The Panel on Contaminants in the Food Chain reviewed the available literature but did not find support for the minimum lethal dose for humans of 2 mg, mentioned in various reviews. Some human case reports describe serious effects at a dose of 0.2 mg, corresponding to 4 μg/kg body...... weight (bw). However, the uncertainties on the actual exposure in the studies preclude their use for derivation of an acute reference dose (ARfD). Instead, a group ARfD of 0.25 μg/kg bw, applying to TTX and its analogues, was derived based on a TTX dose of 25 μg/kg bw at which no apathy was observed...

  18. Effects of anthropogenic sound on digging behavior, metabolism, Ca2+/Mg2+ ATPase activity, and metabolism-related gene expression of the bivalve Sinonovacula constricta

    Science.gov (United States)

    Peng, Chao; Zhao, Xinguo; Liu, Saixi; Shi, Wei; Han, Yu; Guo, Cheng; Jiang, Jingang; Wan, Haibo; Shen, Tiedong; Liu, Guangxu

    2016-01-01

    Anthropogenic sound has increased significantly in the past decade. However, only a few studies to date have investigated its effects on marine bivalves, with little known about the underlying physiological and molecular mechanisms. In the present study, the effects of different types, frequencies, and intensities of anthropogenic sounds on the digging behavior of razor clams (Sinonovacula constricta) were investigated. The results showed that variations in sound intensity induced deeper digging. Furthermore, anthropogenic sound exposure led to an alteration in the O:N ratios and the expression of ten metabolism-related genes from the glycolysis, fatty acid biosynthesis, tryptophan metabolism, and Tricarboxylic Acid Cycle (TCA cycle) pathways. Expression of all genes under investigation was induced upon exposure to anthropogenic sound at ~80 dB re 1 μPa and repressed at ~100 dB re 1 μPa sound. In addition, the activity of Ca2+/Mg2+-ATPase in the feet tissues, which is directly related to muscular contraction and subsequently to digging behavior, was also found to be affected by anthropogenic sound intensity. The findings suggest that sound may be perceived by bivalves as changes in the water particle motion and lead to the subsequent reactions detected in razor clams. PMID:27063002

  19. Effects of anthropogenic sound on digging behavior, metabolism, Ca(2+)/Mg(2+) ATPase activity, and metabolism-related gene expression of the bivalve Sinonovacula constricta.

    Science.gov (United States)

    Peng, Chao; Zhao, Xinguo; Liu, Saixi; Shi, Wei; Han, Yu; Guo, Cheng; Jiang, Jingang; Wan, Haibo; Shen, Tiedong; Liu, Guangxu

    2016-04-11

    Anthropogenic sound has increased significantly in the past decade. However, only a few studies to date have investigated its effects on marine bivalves, with little known about the underlying physiological and molecular mechanisms. In the present study, the effects of different types, frequencies, and intensities of anthropogenic sounds on the digging behavior of razor clams (Sinonovacula constricta) were investigated. The results showed that variations in sound intensity induced deeper digging. Furthermore, anthropogenic sound exposure led to an alteration in the O:N ratios and the expression of ten metabolism-related genes from the glycolysis, fatty acid biosynthesis, tryptophan metabolism, and Tricarboxylic Acid Cycle (TCA cycle) pathways. Expression of all genes under investigation was induced upon exposure to anthropogenic sound at ~80 dB re 1 μPa and repressed at ~100 dB re 1 μPa sound. In addition, the activity of Ca(2+)/Mg(2+)-ATPase in the feet tissues, which is directly related to muscular contraction and subsequently to digging behavior, was also found to be affected by anthropogenic sound intensity. The findings suggest that sound may be perceived by bivalves as changes in the water particle motion and lead to the subsequent reactions detected in razor clams.

  20. Effects of anthropogenic sound on digging behavior, metabolism, Ca2+/Mg2+ ATPase activity, and metabolism-related gene expression of the bivalve Sinonovacula constricta

    Science.gov (United States)

    Peng, Chao; Zhao, Xinguo; Liu, Saixi; Shi, Wei; Han, Yu; Guo, Cheng; Jiang, Jingang; Wan, Haibo; Shen, Tiedong; Liu, Guangxu

    2016-04-01

    Anthropogenic sound has increased significantly in the past decade. However, only a few studies to date have investigated its effects on marine bivalves, with little known about the underlying physiological and molecular mechanisms. In the present study, the effects of different types, frequencies, and intensities of anthropogenic sounds on the digging behavior of razor clams (Sinonovacula constricta) were investigated. The results showed that variations in sound intensity induced deeper digging. Furthermore, anthropogenic sound exposure led to an alteration in the O:N ratios and the expression of ten metabolism-related genes from the glycolysis, fatty acid biosynthesis, tryptophan metabolism, and Tricarboxylic Acid Cycle (TCA cycle) pathways. Expression of all genes under investigation was induced upon exposure to anthropogenic sound at ~80 dB re 1 μPa and repressed at ~100 dB re 1 μPa sound. In addition, the activity of Ca2+/Mg2+-ATPase in the feet tissues, which is directly related to muscular contraction and subsequently to digging behavior, was also found to be affected by anthropogenic sound intensity. The findings suggest that sound may be perceived by bivalves as changes in the water particle motion and lead to the subsequent reactions detected in razor clams.

  1. Effects of arctic temperatures on distribution and retention of the nuclear waste radionuclides 241Am, 57Co, and 137Cs in the bioindicator bivalve Macoma balthica

    Science.gov (United States)

    Hutchins, D.A.; Stupakoff, I.; Hook, S.; Luoma, S.N.; Fisher, N.S.

    1998-01-01

    The disposal of radioactive wastes in Arctic seas has made it important to understand the processes affecting the accumulation of radionuclides in food webs in coldwater ecosystems. We examined the effects of temperature on radionuclide assimilation and retention by the bioindicator bivalve Macoma balthica using three representative nuclear waste components, 241Am, 57Co, and 137Cs. Experiments were designed to determine the kinetics of processes that control uptake from food and water, as well as kinetic constants of loss. 137Cs was not accumulated in soft tissue from water during short exposures, and was rapidly lost from shell with no thermal dependence. No effects of temperature on 57Co assimilation or retention from food were observed. The only substantial effect of polar temperatures was that on the assimilation efficiency of 241Am from food, where 10% was assimilated at 2??C and 26% at 12??C. For all three radionuclides, body distributions were correlated with source, with most radioactivity obtained from water found in the shell and food in the soft tissues. These results suggest that in general Arctic conditions had relatively small effects on the biological processes which influence the bioaccumulation of radioactive wastes, and bivalve concentration factors may not be appreciably different between polar and temperate waters.

  2. [Proceedings of the symposium 'Molluscan Palaeontology' : 11th International Malacological Congress, Siena (Italy) 30th August - 5th September 1992 / A.W. Janssen and R. Janssen (editors)]: The Mesozoic Marine Revolution and epifaunal bivalves

    NARCIS (Netherlands)

    Harper, E.M.; Skelton, P.W.

    1992-01-01

    The well documented dramatic increase in predation pressure which started during the early Mesozoic, termed the Mesozoic Marine Revolution (MMR), had an important impact on the evolution of prey organisms (Vermeij, 1983). Epifaunal bivalves in particular are at considerable risk to predation. In

  3. Rhythmic patterns in ancient shells: Can we reconstruct sub-annual cyclicity in trace element and stable isotope profiles from rudist bivalves?

    Science.gov (United States)

    de Winter, N.; Sinnesael, M.; Vansteenberge, S.; Goderis, S.; Snoeck, C.; Van Malderen, S. J. M.; Vanhaecke, F. F.; Claeys, P.

    2017-12-01

    Well-preserved shells of Torreites rudists from the Late Campanian Saiwan Formation in Oman exhibit fine internal layering. These fine (±20 µm) laminae are rhythmically bundled (±400 µm) and subdivide the shells' larger scale annual lamination (±15 mm), suggesting the presence of several interfering cycles in shell growth rate. The aim of the present study is to determine the duration and chemical signature of these rhythmic variations in shell composition. To achieve this, a range of micro-analytical techniques is applied on cross sections through the shells. Firstly, microscopy-based layer counting and colorimetric analysis are carried out on thin sections of shell calcite. Secondly, X-Ray Fluorescence (XRF) and Fourier Transform InfraRed (FTIR) mapping of cross sections of the shells reveal chemical and structural differences between laminae in 2D. Thirdly, high-resolution XRF (25 µm) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS; 10 µm) trace element profiles are used to quantify variations in chemical composition between shell laminae. Fourthly, annual chronology is established based on micro-sampled stable carbon and oxygen stable isotope measurements (250 µm) along the growth axis of the shells. Finally, spectral analysis routines are applied to extract rhythmic patterns matched to the shell laminae from the structural, chemical and colorimetric data. Combining these methods allows for a full evaluation of the structural and chemical characteristics as well as the timing of sub-annual lamination in rudist shells. The results of this study shed light on the external factors that influenced growth rates in rudist bivalves. A better understanding of the timing of deposition of these laminae allows them to be used to improve age models of geochemical records in rudist shells. Characterization of small scale variations in shell composition will characterize the uncertainties contained within lower resolution proxy records from

  4. Bioaccumulation of selenium and induced biological effects in the filter feeding bivalve Corbicula fluminea: influence of ventilatory activity, selenium speciation and route of transfer

    International Nuclear Information System (INIS)

    Fournier, E.

    2005-10-01

    Selenium is an essential micro-nutrient for most of living organisms. However, toxic effects in several ecosystems have been reported in the literature. Toxicity comprehension is difficult due to the complexity of Se oxidation states in the environment. The aim of this thesis work was to acquire knowledge on the physiological and environmental factors involved in bioaccumulation and toxicity processes in the freshwater filter-feeding bivalve C. fluminea. The aims were: i) to define what the factors involved in Se bioaccumulation processes in the bivalve are, ii) to characterize Se bioaccumulation at different biological organisation levels, iii) to investigate Se toxic effects. First experiments, carried out for short term exposure duration (3 days), have permitted to underline the importance of Se chemical speciation in bioaccumulation processes in C. fluminea. It has been shown that the organic form, seleno-methionine, was much more bio-available than the inorganic forms, selenite and selenate. Moreover, the route of transfer was determinant in those processes. Inorganic forms have been better extracted by trophic route, whereas seleno-methionine has been better extracted by the direct route. In our experimental conditions, ventilation of the bivalve has not been a limiting factor for Se bioaccumulation by the direct route, whereas it has been for bioaccumulation by the trophic route. Ventilation has been largely modified by the presence of dissolved selenite and seleno-methionine. We have shown that the kinetics of seleno-methionine bioaccumulation are much more fast than those of selenite. Moreover, when introduced as SeMet, internalized Se appeared to be relatively remanent in soft tissues of C. fluminea in comparison with Se internalized when introduced as selenite. Subcellular and molecular distributions of these forms were very different. Finally, it has been shown that seleno-methionine and selenite could generate weak alterations of the anti

  5. GREATER HEMOCYTE BACTERICIDAL ACTIVITY IN OYSTERS (CRASSOSTREA VIRGINICA) FROM A RELATIVELY CONTAMINATED SITE IN PENSACOLA BAY, FLORIDA.

    Science.gov (United States)

    Bivalve mollusks such as Crassostrea virginica inhabiting polluted estuaries and coastal areas may bioaccumulate high concentrations of contaminants without apparent ill effects. However, changes in putative internal defense activities have been associated with contaminant accumu...

  6. Emerging and potential technologies for facilitating shrimp peeling: A review

    DEFF Research Database (Denmark)

    Dang, Tem Thi; Gringer, Nina; Jessen, Flemming

    2018-01-01

    , ultrasound and microwave can potentially become the alternatives since they have strong peeling effects on lobsters, crabs, bivalve mollusks, eggshells, human skin, fruits and vegetables. Also these technologies offer benefits such as short process time, retained nutritional and sensorial characteristics...

  7. Spatial and temporal distribution of tributyltin (TBT) in seawater, sediments and bivalves from coastal areas of Korea during 2001-2005.

    Science.gov (United States)

    Choi, Minkyu; Choi, Hee-Gu; Moon, Hyo-Bang; Kim, Gui-Young

    2009-04-01

    Tributyltin (TBT) concentrations were determined in seawater, sediments and bivalve samples collected from Korean coastal areas during 2001-2005, to investigate the levels and temporal variation in TBT contamination in relation to the timing of the imposition of regulations on TBT use in Korea. TBT concentrations ranged from TBT were found at locations close to intensive shipping traffic and industrial complexes, and the contamination at some hot spot areas was high enough to cause harmful effects on marine organisms. TBT concentrations and their occurrence in Korean coastal waters have been decreasing annually. In particular, TBT concentrations in seawater have dramatically decreased. This result is consistent with regulations and bans on the use of TBT in Korea.

  8. Environmental DNA (eDNA metabarcoding assays to detect invasive invertebrate species in the Great Lakes.

    Directory of Open Access Journals (Sweden)

    Katy E Klymus

    Full Text Available Describing and monitoring biodiversity comprise integral parts of ecosystem management. Recent research coupling metabarcoding and environmental DNA (eDNA demonstrate that these methods can serve as important tools for surveying biodiversity, while significantly decreasing the time, expense and resources spent on traditional survey methods. The literature emphasizes the importance of genetic marker development, as the markers dictate the applicability, sensitivity and resolution ability of an eDNA assay. The present study developed two metabarcoding eDNA assays using the mtDNA 16S RNA gene with Illumina MiSeq platform to detect invertebrate fauna in the Laurentian Great Lakes and surrounding waterways, with a focus for use on invasive bivalve and gastropod species monitoring. We employed careful primer design and in vitro testing with mock communities to assess ability of the markers to amplify and sequence targeted species DNA, while retaining rank abundance information. In our mock communities, read abundances reflected the initial input abundance, with regressions having significant slopes (p<0.05 and high coefficients of determination (R2 for all comparisons. Tests on field environmental samples revealed similar ability of our markers to measure relative abundance. Due to the limited reference sequence data available for these invertebrate species, care must be taken when analyzing results and identifying sequence reads to species level. These markers extend eDNA metabarcoding research for molluscs and appear relevant to other invertebrate taxa, such as rotifers and bryozoans. Furthermore, the sphaeriid mussel assay is group-specific, exclusively amplifying bivalves in the Sphaeridae family and providing species-level identification. Our assays provide useful tools for managers and conservation scientists, facilitating early detection of invasive species as well as improving resolution of mollusc diversity.

  9. Using biochemical and isotope geochemistry to understand the environmental and public health implications of lead pollution in the lower Guadiana River, Iberia: A freshwater bivalve study

    Energy Technology Data Exchange (ETDEWEB)

    Company, R. [CIMA, Faculty of Marine and Environmental Sciences, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)], E-mail: rcompany@ualg.pt; Serafim, A.; Lopes, B.; Cravo, A. [CIMA, Faculty of Marine and Environmental Sciences, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Shepherd, T.J.; Pearson, G. [Department of Earth Sciences, Durham University, Science Labs., Durham DH1 3LE (United Kingdom); Bebianno, M.J. [CIMA, Faculty of Marine and Environmental Sciences, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)], E-mail: mbebian@ualg.pt

    2008-11-01

    Lead is a natural component of aquatic ecosystems with no known biological role and is highly toxic. Its toxicity stems from its ability to mimic biologically important metals and to produce membrane damage through lipid peroxidation (LPO). Most lead poisoning symptoms are thought to occur by interfering with an essential enzyme, {delta}-aminolevulinic acid dehydratase (ALAD), the activity of which is markedly inhibited by lead. The purpose of this work was to study the levels and effects of lead pollution (responses of ALAD and oxidative stress biomarker LPO) in the freshwater bivalve Corbicula fluminea along the lower Guadiana River (Portugal and Spain); a major river system impacted by historic mining pollution and more recent anthropogenic inputs. The results show that the enzymatic activity of ALAD is negatively correlated with the total Pb concentration of the whole tissue suggesting that ALAD has considerable potential as a biomarker of lead exposure in C. fluminea. To identify the sources of lead to which bivalves have been exposed, high precision {sup 206}Pb/{sup 204}Pb, {sup 207}Pb/{sup 204}Pb, {sup 208}Pb/{sup 204}/Pb ratios for C. fluminea confirm that historical mining activities in the Iberian Pyrite Belt are the dominant source of lead pollution in the lower Guadiana River. The isotope patterns however exhibit marked seasonal and geographic variation in response to rainfall and river water management. Locally, other anthropogenic sources of lead have been detected in C. fluminea close to population centres, thus adding to its versatility as a freshwater bio-indicator. Overall, the study highlights the value of natural ecosystems as monitors of water quality and their importance for public health assessment and surveillance.

  10. Use of a combined effect model approach for discriminating between ABCB1- and ABCC1-type efflux activities in native bivalve gill tissue

    Energy Technology Data Exchange (ETDEWEB)

    Faria, Melissa [Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18, 08034 Barcelona (Spain); CESAM & Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Pavlichenko, Vasiliy [Siberian Institute of Plant Physiology and Biochemistry, Siberian Branch of Russian Academy of Sciences (SIPPB SB RAS), Lermontov Str. 132, 664033, Irkutsk (Russian Federation); Department of Bioanalytical Ecotoxicology, UFZ — Helmholtz Centre for Environmental Research, Permoserstr. 15, D-04318 Leipzig (Germany); Burkhardt-Medicke, Kathleen [Department of Bioanalytical Ecotoxicology, UFZ — Helmholtz Centre for Environmental Research, Permoserstr. 15, D-04318 Leipzig (Germany); Institute of Hydrobiology, Dresden University of Technology, D-01062 Dresden (Germany); Soares, Amadeu M.V.M. [CESAM & Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Altenburger, Rolf [Department of Bioanalytical Ecotoxicology, UFZ — Helmholtz Centre for Environmental Research, Permoserstr. 15, D-04318 Leipzig (Germany); Barata, Carlos [Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18, 08034 Barcelona (Spain); Luckenbach, Till, E-mail: till.luckenbach@ufz.de [Department of Bioanalytical Ecotoxicology, UFZ — Helmholtz Centre for Environmental Research, Permoserstr. 15, D-04318 Leipzig (Germany)

    2016-04-15

    Aquatic organisms, such as bivalves, employ ATP binding cassette (ABC) transporters for efflux of potentially toxic chemicals. Anthropogenic water contaminants can, as chemosensitizers, disrupt efflux transporter function enabling other, putatively toxic compounds to enter the organism. Applying rapid amplification of cDNA ends (RACE) PCR we identified complete cDNAs encoding ABCB1- and ABCC1-type transporter homologs from zebra mussel providing the molecular basis for expression of both transporter types in zebra mussel gills. Further, efflux activities of both transporter types in gills were indicated with dye accumulation assays where efflux of the dye calcein-am was sensitive to both ABCB1- (reversin 205, verapamil) and ABCC1- (MK571) type specific inhibitors. The assumption that different inhibitors targeted different efflux pump types was confirmed when comparing measured effects of binary inhibitor compound mixtures in dye accumulation assays with predictions from mixture effect models. Effects by the MK571/reversin 205 mixture corresponded better with independent action, whereas reversin 205/verapamil joint effects were better predicted by the concentration addition model indicating different and equal targets, respectively. The binary mixture approach was further applied to identify the efflux pump type targeted by environmentally relevant chemosensitizing compounds. Pentachlorophenol and musk ketone, which were selected after a pre-screen of twelve compounds that previously had been identified as chemosensitizers, showed mixture effects that corresponded better with concentration addition when combined with reversine 205 but with independent action predictions when combined with MK571 indicating targeting of an ABCB1-type efflux pump by these compounds. - Highlights: • Sequences and function of ABC efflux transporters in bivalve gills were explored. • Full length Dreissena polymorpha abcb1 and abcc1 cDNA sequences were identified. • A mixture effect

  11. Using biochemical and isotope geochemistry to understand the environmental and public health implications of lead pollution in the lower Guadiana River, Iberia: a freshwater bivalve study.

    Science.gov (United States)

    Company, R; Serafim, A; Lopes, B; Cravo, A; Shepherd, T J; Pearson, G; Bebianno, M J

    2008-11-01

    Lead is a natural component of aquatic ecosystems with no known biological role and is highly toxic. Its toxicity stems from its ability to mimic biologically important metals and to produce membrane damage through lipid peroxidation (LPO). Most lead poisoning symptoms are thought to occur by interfering with an essential enzyme, delta-aminolevulinic acid dehydratase (ALAD), the activity of which is markedly inhibited by lead. The purpose of this work was to study the levels and effects of lead pollution (responses of ALAD and oxidative stress biomarker LPO) in the freshwater bivalve Corbicula fluminea along the lower Guadiana River (Portugal and Spain); a major river system impacted by historic mining pollution and more recent anthropogenic inputs. The results show that the enzymatic activity of ALAD is negatively correlated with the total Pb concentration of the whole tissue suggesting that ALAD has considerable potential as a biomarker of lead exposure in C. fluminea. To identify the sources of lead to which bivalves have been exposed, high precision (206)Pb/(204)Pb, (207)Pb/(204)Pb, (208)Pb/(204)/Pb ratios for C. fluminea confirm that historical mining activities in the Iberian Pyrite Belt are the dominant source of lead pollution in the lower Guadiana River. The isotope patterns however exhibit marked seasonal and geographic variation in response to rainfall and river water management. Locally, other anthropogenic sources of lead have been detected in C. fluminea close to population centres, thus adding to its versatility as a freshwater bio-indicator. Overall, the study highlights the value of natural ecosystems as monitors of water quality and their importance for public health assessment and surveillance.

  12. Using biochemical and isotope geochemistry to understand the environmental and public health implications of lead pollution in the lower Guadiana River, Iberia: A freshwater bivalve study

    International Nuclear Information System (INIS)

    Company, R.; Serafim, A.; Lopes, B.; Cravo, A.; Shepherd, T.J.; Pearson, G.; Bebianno, M.J.

    2008-01-01

    Lead is a natural component of aquatic ecosystems with no known biological role and is highly toxic. Its toxicity stems from its ability to mimic biologically important metals and to produce membrane damage through lipid peroxidation (LPO). Most lead poisoning symptoms are thought to occur by interfering with an essential enzyme, δ-aminolevulinic acid dehydratase (ALAD), the activity of which is markedly inhibited by lead. The purpose of this work was to study the levels and effects of lead pollution (responses of ALAD and oxidative stress biomarker LPO) in the freshwater bivalve Corbicula fluminea along the lower Guadiana River (Portugal and Spain); a major river system impacted by historic mining pollution and more recent anthropogenic inputs. The results show that the enzymatic activity of ALAD is negatively correlated with the total Pb concentration of the whole tissue suggesting that ALAD has considerable potential as a biomarker of lead exposure in C. fluminea. To identify the sources of lead to which bivalves have been exposed, high precision 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, 208 Pb/ 204 /Pb ratios for C. fluminea confirm that historical mining activities in the Iberian Pyrite Belt are the dominant source of lead pollution in the lower Guadiana River. The isotope patterns however exhibit marked seasonal and geographic variation in response to rainfall and river water management. Locally, other anthropogenic sources of lead have been detected in C. fluminea close to population centres, thus adding to its versatility as a freshwater bio-indicator. Overall, the study highlights the value of natural ecosystems as monitors of water quality and their importance for public health assessment and surveillance

  13. Cephalic and Limb Anatomy of a New Isoxyid from the Burgess Shale and the Role of “Stem Bivalved Arthropods” in the Disparity of the Frontalmost Appendage

    Science.gov (United States)

    Aria, Cédric; Caron, Jean-Bernard

    2015-01-01

    We herein describe Surusicaris elegans gen. et sp. nov. (in Isoxyidae, amended), a middle (Series 3, Stage 5) Cambrian bivalved arthropod from the new Burgess Shale deposit of Marble Canyon (Kootenay National Park, British Columbia). Surusicaris exhibits 12 simple, partly undivided biramous trunk limbs with long tripartite caeca, which may illustrate a plesiomorphic “fused” condition of exopod and endopod. We construe also that the head is made of five somites (= four segments), including two eyes, one pair of anomalocaridid-like frontalmost appendages, and three pairs of poorly sclerotized uniramous limbs. This fossil may therefore be a candidate for illustrating the origin of the plesiomorphic head condition in euarthropods, and questions the significance of the “two-segmented head” in, e.g., fuxianhuiids. The frontalmost appendage in isoxyids is intriguingly disparate, bearing similarities with both dinocaridids and euarthropods. In order to evaluate the relative importance of bivalved arthropods, such as Surusicaris, in the hypothetical structuro-functional transition between the dinocaridid frontal appendage and the pre-oral—arguably deutocerebral—appendage of euarthropods, we chose a phenetic approach and computed morphospace occupancy for the frontalmost appendages of 36 stem and crown taxa. Results show different levels of evolutionary decoupling between frontalmost appendage disparity and body plans. Variance is greatest in dinocaridids and “stem bivalved” arthropods, but these groups do not occupy the morphospace homogeneously. Rather, the diversity of frontalmost appendages in “stem bivalved” arthropods, distinct in its absence of clear clustering, is found to link the morphologies of “short great appendages,” chelicerae and antennules. This find fits the hypothesis of an increase in disparity of the deutocerebral appendage prior to its diversification in euarthropods, and possibly corresponds to its original time of development

  14. Use of a combined effect model approach for discriminating between ABCB1- and ABCC1-type efflux activities in native bivalve gill tissue

    International Nuclear Information System (INIS)

    Faria, Melissa; Pavlichenko, Vasiliy; Burkhardt-Medicke, Kathleen; Soares, Amadeu M.V.M.; Altenburger, Rolf; Barata, Carlos; Luckenbach, Till

    2016-01-01

    Aquatic organisms, such as bivalves, employ ATP binding cassette (ABC) transporters for efflux of potentially toxic chemicals. Anthropogenic water contaminants can, as chemosensitizers, disrupt efflux transporter function enabling other, putatively toxic compounds to enter the organism. Applying rapid amplification of cDNA ends (RACE) PCR we identified complete cDNAs encoding ABCB1- and ABCC1-type transporter homologs from zebra mussel providing the molecular basis for expression of both transporter types in zebra mussel gills. Further, efflux activities of both transporter types in gills were indicated with dye accumulation assays where efflux of the dye calcein-am was sensitive to both ABCB1- (reversin 205, verapamil) and ABCC1- (MK571) type specific inhibitors. The assumption that different inhibitors targeted different efflux pump types was confirmed when comparing measured effects of binary inhibitor compound mixtures in dye accumulation assays with predictions from mixture effect models. Effects by the MK571/reversin 205 mixture corresponded better with independent action, whereas reversin 205/verapamil joint effects were better predicted by the concentration addition model indicating different and equal targets, respectively. The binary mixture approach was further applied to identify the efflux pump type targeted by environmentally relevant chemosensitizing compounds. Pentachlorophenol and musk ketone, which were selected after a pre-screen of twelve compounds that previously had been identified as chemosensitizers, showed mixture effects that corresponded better with concentration addition when combined with reversine 205 but with independent action predictions when combined with MK571 indicating targeting of an ABCB1-type efflux pump by these compounds. - Highlights: • Sequences and function of ABC efflux transporters in bivalve gills were explored. • Full length Dreissena polymorpha abcb1 and abcc1 cDNA sequences were identified. • A mixture effect

  15. Spatially Extended Habitat Modification by Intertidal Reef-Building Bivalves has Implications for Consumer-Resource Interactions

    NARCIS (Netherlands)

    van der Zee, E.M.; van der Heide, T.; Donadi, S.; Eklöf, J.S.; Eriksson, B.K.; Olff, H.; van der Veer, H.W.; Piersma, T.

    2012-01-01

    Ecosystem engineers can strongly modify habitat structure and resource availability across space. In theory, this should alter the spatial distributions of trophically interacting species. In this article, we empirically investigated the importance of spatially extended habitat modification by

  16. Spatially extended habitat modification by intertidal reef-building bivalves has implications for consumer-resource interactions

    NARCIS (Netherlands)

    van der Zee, Els M.; van der Heide, Tjisse; Donadi, Serena; Eklöf, Johan S.; Eriksson, Britas Klemens; Olff, Han; van der Veer, Henk W.; Piersma, Theunis

    Ecosystem engineers can strongly modify habitat structure and resource availability across space. In theory, this should alter the spatial distributions of trophically interacting species. In this article, we empirically investigated the importance of spatially extended habitat modification by

  17. SALMONELLA SPECIES

    African Journals Online (AJOL)

    DR. AMINU

    ... of Salmonella species serotypes in relation to age and sex among children, ..... However, most antimicrobials show sufficient selective toxicity to be of value in ... salmonellosis should be given good attention (Barrow et al., 2007). To reduce ...

  18. Radionuclide transfer to freshwater biota species: review of Russian language studies

    Energy Technology Data Exchange (ETDEWEB)

    Fesenko, S., E-mail: s.fesenko@iaea.or [International Atomic Energy Agency, NAAL, 1400 Vienna (Austria); Fesenko, J.; Sanzharova, N.; Karpenko, E.; Titov, I. [Russian Institute of Agricultural Radiology and Radioecology, 249020 Obninsk (Russian Federation)

    2011-01-15

    Around 130 publications reporting studies on radionuclide transfer to freshwater biota species conducted in the former USSR were reviewed to provide the concentration ratio values. None of these studies were available up to now in the English language reviews or publications. The values derived have been compared with the CR values used for freshwater systems in the International reviews. For some radionuclides reviewed in this paper, the data are in good agreement with the mean CR values presented earlier, however for some of them, in particular, for {sup 241}Am (bivalve molluscs, gastropods and pelagic fish), {sup 60}Co (gastropods, benthic fish and insect larvae), {sup 90}Sr and {sup 137}Cs (benthic fish and zooplankton), the mean values given here are substantially different from those presented earlier. The data reported in this paper for thirty five radionuclides and eleven groups of freshwater species markedly improve the extent of available data for evaluation of radiation impact on freshwater species. - Research highlights: {yields} The paper provides information on concentration ratios to freshwater biota species for 35 radionuclides. Many of the data are for {sup 90}Sr and {sup 137}Cs. {yields} For the majority of radionuclides reviewed in this paper, the CR values are in good agreement with those given in the recent International reviews. {yields} For {sup 241}Am (bivalve molluscs, gastropods and pelagic fish), {sup 60}Co (gastropods, benthic fish and insect larvae), {sup 90}Sr and {sup 137}Cs (benthic fish and zooplankton), the mean values based on review of the Russian language publications are substantially different from those presented in the International reviews. {yields} Information presented in the paper significantly increases the availability of data on radionuclide accumulation in freshwater species.

  19. Radionuclide transfer to freshwater biota species: review of Russian language studies

    International Nuclear Information System (INIS)

    Fesenko, S.; Fesenko, J.; Sanzharova, N.; Karpenko, E.; Titov, I.

    2011-01-01

    Around 130 publications reporting studies on radionuclide transfer to freshwater biota species conducted in the former USSR were reviewed to provide the concentration ratio values. None of these studies were available up to now in the English language reviews or publications. The values derived have been compared with the CR values used for freshwater systems in the International reviews. For some radionuclides reviewed in this paper, the data are in good agreement with the mean CR values presented earlier, however for some of them, in particular, for 241 Am (bivalve molluscs, gastropods and pelagic fish), 60 Co (gastropods, benthic fish and insect larvae), 90 Sr and 137 Cs (benthic fish and zooplankton), the mean values given here are substantially different from those presented earlier. The data reported in this paper for thirty five radionuclides and eleven groups of freshwater species markedly improve the extent of available data for evaluation of radiation impact on freshwater species. - Research highlights: → The paper provides information on concentration ratios to freshwater biota species for 35 radionuclides. Many of the data are for 90 Sr and 137 Cs. → For the majority of radionuclides reviewed in this paper, the CR values are in good agreement with those given in the recent International reviews. → For 241 Am (bivalve molluscs, gastropods and pelagic fish), 60 Co (gastropods, benthic fish and insect larvae), 90 Sr and 137 Cs (benthic fish and zooplankton), the mean values based on review of the Russian language publications are substantially different from those presented in the International reviews. → Information presented in the paper significantly increases the availability of data on radionuclide accumulation in freshwater species.

  20. Microplastics as contaminants in commercially important seafood species.

    Science.gov (United States)

    Santillo, David; Miller, Kathryn; Johnston, Paul

    2017-05-01

    The ingestion of microplastic fragments, spheres, and fibers by marine mollusks, crustaceans, and fish, including a number of commercially important species, appears to be a widespread and pervasive phenomenon. Evidence is also growing for direct impacts of microplastic ingestion on physiology, reproductive success and survival of exposed marine organisms, and transfer through food webs, although the ecological implications are not yet known. Concerns also remain over the capacity for microplastics to act as vectors for harmful chemical pollutants, including plastic additives and persistent organic pollutants, although their contribution must be evaluated alongside other known sources. The potential for humans, as top predators, to consume microplastics as contaminants in seafood is very real, and its implications for health need to be considered. An urgent need also exists to extend the geographical scope of studies of microplastic contamination in seafood species to currently underrepresented areas, and to finalize and adopt standardized methods and quality-assurance protocols for the isolation, identification, and quantification of microplastic contaminants from biological tissues. Such developments would enable more robust investigation of spatial and temporal trends, thereby contributing further evidence as a sound basis for regulatory controls. Despite the existence of considerable uncertainties and unknowns, there is already a compelling case for urgent actions to identify, control, and, where possible, eliminate key sources of both primary and secondary microplastics before they reach the marine environment. Integr Environ Assess Manag 2017;13:516-521. © 2017 SETAC. © 2017 SETAC.

  1. Bioaccumulation of selenium and induced biological effects in the filter feeding bivalve Corbicula fluminea: influence of ventilatory activity, selenium speciation and route of transfer; Bioaccumulation du selenium et effets biologiques induits chez le bivalve filtreur Corbicula fluminea: prise en compte de l'activite ventilatoire, de la speciation du selenium et de la voie de contamination

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, E

    2005-10-15

    Selenium is an essential micro-nutrient for most of living organisms. However, toxic effects in several ecosystems have been reported in the literature. Toxicity comprehension is difficult due to the complexity of Se oxidation states in the environment. The aim of this thesis work was to acquire knowledge on the physiological and environmental factors involved in bioaccumulation and toxicity processes in the freshwater filter-feeding bivalve C. fluminea. The aims were: i) to define what the factors involved in Se bioaccumulation processes in the bivalve are, ii) to characterize Se bioaccumulation at different biological organisation levels, iii) to investigate Se toxic effects. First experiments, carried out for short term exposure duration (3 days), have permitted to underline the importance of Se chemical speciation in bioaccumulation processes in C. fluminea. It has been shown that the organic form, seleno-methionine, was much more bio-available than the inorganic forms, selenite and selenate. Moreover, the route of transfer was determinant in those processes. Inorganic forms have been better extracted by trophic route, whereas seleno-methionine has been better extracted by the direct route. In our experimental conditions, ventilation of the bivalve has not been a limiting factor for Se bioaccumulation by the direct route, whereas it has been for bioaccumulation by the trophic route. Ventilation has been largely modified by the presence of dissolved selenite and seleno-methionine. We have shown that the kinetics of seleno-methionine bioaccumulation are much more fast than those of selenite. Moreover, when introduced as SeMet, internalized Se appeared to be relatively remanent in soft tissues of C. fluminea in comparison with Se internalized when introduced as selenite. Subcellular and molecular distributions of these forms were very different. Finally, it has been shown that seleno-methionine and selenite could generate weak alterations of the anti

  2. Of tests, trochs, shells, and spicules: Development of the basal mollusk Wirenia argentea (Solenogastres) and its bearing on the evolution of trochozoan larval key features

    DEFF Research Database (Denmark)

    Todt, Christiane; Wanninger, Andreas

    2010-01-01

    ) to be derived. Larval characters are central in these discussions, specifically the larval test (calymma, apical cap), the ontogeny of the epidermal scleritome, and the proposed absence of larval protonephridia. To date, developmental data are available for five solenogaster species, but most reports...... a fully developed foregut, but the midgut and hindgut are not yet interconnected. CONCLUSIONS: Solenogastres develop via a trochophore-like lecitotrophic larva with a preoral apical cap that at least partly represents an enlarged prototrochal area. Homology of this larval type (pericalymma larva) to test...

  3. Trace elements in bivalves from the Rio Cruces, Chile, trace watershed evolution after a major earthquake and challenge a postulated chemical spill from a pulp plant

    Science.gov (United States)

    Risk, M.; Burchell, M.; Nairn, R.; Tubrett, M.; Forsterra, G.

    2009-05-01

    In May, 1960, the largest recorded earthquake in the history of the planet hit southern Chile, dropping part of the course of the Rio Cruces by 2m and creating an extensive wetland. The Brazilian Waterweed Egeria densa colonised the area, and became a primary food source for large populations of the Black-necked Swan, Cygnus melancoryphus. In 2004, a large pulp mill commenced operations upstream on the river. According to local reports, immediately after the opening of the plant, the weed died and the swans left. There was public outcry, and a search for a cause or a culprit. It was postulated that some sort of chemical spill from the plant caused the weed to die, resulting in departure of the swans. In 2008, we collected specimens of the bivalve Diplodon chilensis from several locations downstream from the Plant and towards the wetland to see if there was evidence of a chemical spill recorded in the shells. We prepared thin-sections of the shells to observe growth line development and patterns. Additionally, shell samples were analysed for stable oxygen isotopes and trace elements, using LA-ICP/MS. Based on annual growth lines, some of the bivalves were long-lived, with an age of more than 50 years. These individuals settled in the river shortly after the earthquake, and have lived there continuously ever since. Annual and sub-annual banding was clear, and the annual cyclicity of the major bands was verified with oxygen isotope analysis. There are no changes in growth corresponding to 2004. Trace element scans provided a wealth of information on the evolution of this earthquake-impacted wetland. Barium, Strontium and Manganese all showed strong annual cyclicity. From the analysis of older specimens, we interpret the high peaks of the Ba signal as reflecting soil erosion-Ba peaks are large immediately after the earthquake, then they diminish through time. Sr is likely a temperature signal, and Mn reflects runoff. Minor peaks in Cu, As and Pb probably reflect

  4. Invasive zebra mussels (Driessena polymorpha) and Asian clams (Corbicula fluminea) survive gut passage of migratory fish species: implications for dispersal

    Science.gov (United States)

    Gatlin, Michael R.; Shoup, Daniel E.; Long, James M.

    2013-01-01

    The introduction and spread of invasive species is of great concern to natural resource managers in the United States. To effectively control the spread of these species, managers must be aware of the multitude of dispersal methods used by the organisms. We investigated the potential for survival through the gut of a migrating fish (blue catfish, Ictalurus furcatus) as a dispersal mechanism for two invasive bivalves: zebra mussel (Driessena polymorpha) and Asian clam (Corbicula fluminea). Blue catfish (N = 62) were sampled over several months from Sooner Lake, Oklahoma, transported to a laboratory and held in individual tanks for 48 h. All fecal material was collected and inspected for live mussels. Survival was significantly related to water temperature in the lake at the time of collection, with no mussels surviving above 21.1 C°, whereas 12 % of zebra mussels (N = 939) and 39 % of Asian clams (N = 408) consumed in cooler water survived gut passage. This research demonstrates the potential for blue catfish to serve as a dispersal vector for invasive bivalves at low water temperatures.

  5. Mesocosm validation of the marine No Effect Concentration of dissolved copper derived from a species sensitivity distribution.

    Science.gov (United States)

    Foekema, E M; Kaag, N H B M; Kramer, K J M; Long, K

    2015-07-15

    The Predicted No Effect Concentration (PNEC) for dissolved copper based on the species sensitivity distribution (SSD) of 24 marine single species tests was validated in marine mesocosms. To achieve this, the impact of actively maintained concentrations of dissolved copper on a marine benthic and planktonic community was studied in 18 outdoor 4.6m(3) mesocosms. Five treatment levels, ranging from 2.9 to 31μg dissolved Cu/L, were created in triplicate and maintained for 82days. Clear effects were observed on gastropod and bivalve molluscs, phytoplankton, zooplankton, sponges and sessile algae. The most sensitive biological endpoints; reproduction success of the bivalve Cerastoderma edule, copepod population development and periphyton growth were significantly affected at concentrations of 9.9μg Cu/L and higher. The No Observed Effect Concentration (NOEC) derived from this study was 5.7μg dissolved Cu/L. Taking into account the DOC concentration of the mesocosm water this NOEC is comparable to the PNEC derived from the SSD. Copyright © 2015. Published by Elsevier B.V.

  6. Experimental effects of immersion time and water temperature on body condition, burying depth and timing of spawning of the tellinid bivalve Macoma balthica

    Science.gov (United States)

    de Goeij, Petra; Honkoop, Pieter J.

    2003-03-01

    The burying depth of many bivalve molluscs on intertidal mudflats varies throughout the year and differs between places. Many factors are kno