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| Registros recuperados: 74 | |
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| Dupuy, Christine; Pastoureaud, Annie; Ryckaert, Mireille; Sauriau, Pierre-guy; Montanie, Hélène. |
| To assess the in situ impact of oysters Crassostrea gigas on planktonic protist and bacteria communities and the potential contribution of protozoa to their food resource intake, the abundance and the diversity of protists and bacteria were followed in 2 Atlantic coastal ponds, with and without oysters. The protist biomass in such ponds was high, with a maximum in spring of 982 mug C l(-1) and a minimum in winter of 179 pg C l(-1). Whatever the season, the presence of oysters (20 m(-2) corresponding to an average of 23 mg dry weight m(-2)) induced a significant decrease in >5 pm protist abundance. On the contrary, planktonic organisms <5 pm, such as Chlorophyta flagellates and bacteria, developed similarly in both ponds. It can be assumed that such... |
| Tipo: Text |
Palavras-chave: Trophic link; Bacteria; Protists; Microbial food web; Coastal pond; Food source; Oysters; Bivalve. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-822.pdf |
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| Dupuy, Christine; Vaquer, André; Lam Hoai, Thong; Rougier, Claude; Mazouni, Nabila; Lautier, Jacques; Collos, Yves; Le Gall, Solange. |
| The Mediterranean Thau Lagoon is an important oyster farming area in Europe. Oyster growth rates are among the highest in France, although chlorophyll a concentration is low. Previous studies have demonstrated that picophytoplankton, nano-microphytoplankton, dinoflagellates and loricate ciliates such as tintinnids are abundant. However, heterotrophic flagellates and aloricate ciliates have not been investigated. The aim of this study was to assess picophytoplankton, protist and zooplankton abundances in the Lagoon and to investigate the particular structure of the microbial food web, which may explain such paradoxical oyster growth. In oligotrophic waters in the Thau Lagoon, the picoeukaryote Ostreococcus tauri is the dominant autotrophic picoplankter,... |
| Tipo: Text |
Palavras-chave: Trophic link; Picophytoplankton; Heterotrophic protist; Microbial food web; Thau Lagoon; Food source; Oyster; Bivalve. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-812.pdf |
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| Dutertre, Mickael; Beninger, Peter G.; Barille, Laurent; Papin, Mathias; Rosa, Philippe; Barille, Anne-laure; Haure, Joel. |
| The proliferation of the voluntarily-introduced cupped oyster, Crassostrea gigas, has attained the proportions of species invasion in many intertidal habitats in Europe, presumably resulting from successful reproduction of farmed individuals. It is thus imperative to better understand the reproductive characteristics of farmed oysters, since they are directly under human control. We quantified the dry tissue mass (DTM), gametosomatic index (GSI), and reproductive cycle of farmed oysters at two sites in Bourgneuf Bay, France, in relation to environmental parameters using continuously-recording probes in 2005 and 2006. The GSI was developed for this study, based on the actual area occupied by gametes, rather than the area of the gonad previously used for... |
| Tipo: Text |
Palavras-chave: Atlantic Ocean; Crassostrea gigas; Oyster farming; Bivalve; Gametosomatic index; Biological invasion; Atresia; Oocytes; Turbidity; Temperature; Reproduction. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6871.pdf |
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| Fuhrmann, Marine; Delisle, Lizenn; Petton, Bruno; Corporeau, Charlotte; Pernet, Fabrice. |
| The Pacific oyster, Crassostrea gigas, is an osmoconforming bivalve exposed to wide salinity fluctuations. The physiological mechanisms used by oysters to cope with salinity stress are energy demanding and may impair other processes, such as defense against pathogens. This oyster species has been experiencing recurrent mortality events caused by the Ostreid herpesvirus 1 (OsHV-1). The objectives of this study were to investigate the effect of salinity (10, 15, 25 and 35‰) on energetic reserves, key enzyme activities and membrane fatty acids, and to identify the metabolic risk factors related to OsHV-1-induced mortality of oysters. Acclimation to low salinity led to increased water content, protein level, and energetic reserves (carbohydrates and... |
| Tipo: Text |
Palavras-chave: Bivalve; Disease; Environment; Metabolism; Mortality risk; Salinity. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00427/53886/54958.pdf |
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| Fuhrmann, Marine; Petton, Bruno; Quillien, Virgile; Faury, Nicole; Morga, Benjamin; Pernet, Fabrice. |
| Mortality of young Pacific oysters Crassostrea gigas associated with the ostreid herpesvirus 1 (OsHV-1) is occurring worldwide. Here, we examined for the first time the effect of salinity on OsHV-1 transmission and disease-related mortality of C. gigas, as well as salinity-related effects on the pathogen itself. To obtain donors for OsHV-1 transmission, we transferred laboratory-raised oysters to an estuary during a disease outbreak and then back to the laboratory. Oysters that tested OsHV-1 positive were placed in seawater tanks (35‰, 21°C). Water from these tanks was used to infect naïve oysters in 2 experimental setups: (1) oysters acclimated or non-acclimated to a salinity of 10, 15, 25 and 35‰ and (2) oysters acclimated to a salinity of 25‰; the... |
| Tipo: Text |
Palavras-chave: Bivalve; Herpesviridae; Infection; Disease transmission; Risk analysis. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00350/46100/45781.pdf |
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| Fuhrmann, Marine; Richard, Gaëlle; Quere, Claudie; Petton, Bruno; Pernet, Fabrice. |
| Environmental change in the marine realm has been accompanied by emerging diseases as new pathogens evolve to take advantage of hosts weakened by environmental stress. Here we investigated how an exposure to reduced seawater pH influenced the response of the oyster Crassostrea gigas to an infection by the Ostreid herpesvirus type I (OsHV-1). Oysters were acclimated at pH 8.1 or pH 7.8 and then exposed to OsHV-1. Their survival was monitored and oyster tissues were sampled for biochemical analyses. The survival of oysters exposed to OsHV-1 at pH 7.8 was lower (33.5%) than that of their counterparts at pH 8.1 (44.8%) whereas levels of OsHV-1 DNA were similar. Energetic reserves, fatty acid composition and prostaglandin levels in oyster did not vary... |
| Tipo: Text |
Palavras-chave: Acidification; Bivalve; Disease; Environment; Metabolism; Mortality risk. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00472/58334/60887.pdf |
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| Gangnery, Aline; Normand, Julien; Duval, Cyrielle; Cugier, Philippe; Grangeré, Karine; Petton, Bruno; Petton, Sebastien; Orvain, Francis; Pernet, Fabrice. |
| Oyster diseases have major consequences on fisheries and aquaculture. In France, young Pacific oysters Crassostrea gigas are severely hit by the ostreid herpesvirus, whereas adults suffer mortalities presumably caused by pathogenic bacteria. Here we investigated the origin and spread of mortalities that affect both young and adult oysters, and we identified and compared their risk factors. Mortality was monitored in 2 age classes of oysters deployed in early spring at 39 sites spread over a 37 km2 surface area inside and outside of shellfish farms. Environmental data obtained from numerical modelling were used to investigate risk factors. Mortality of young oysters associated with ostreid herpesvirus occurred in the oyster farming area. Hydrodynamic... |
| Tipo: Text |
Palavras-chave: Aquaculture; Bivalve; Disease; Epidemiology and health; Ecological modelling; Hydrodynamic connectivity. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/69983/67896.pdf |
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| Gerard, Andre; Peignon, Jean-marie; Chagot, Dominique. |
| Individual determination of ploidy level in experimentally induced triploid bivalve molluscs using image cytometry. The sexual maturation in bivalve molluscs causes decreased growth and sometimes increased mortalities. These drawbacks can be avoided by genetic sterilization (triploidy). Triploïdy induction require a egg treatment and a ploidy control at each generation. The ploidy level is usually determined by counting the chromosomes, a technique which is relatively easy for the trochophora stage and for juveniles measuring from 5 mm to 3 cm only. ln order to be able to follow up the evolution of the ploidy rate during any stage of animallife, we have developed an estimation method based on image cytometry. Individual DNA content is determined by... |
| Tipo: Text |
Palavras-chave: Image cytometry; Caryology; Triploidy; Bivalve; Imagerie numérique; Caryologie; Triploïdie; Bivalve. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/1991/acte-3202.pdf |
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| Heral, Maurice; Lucas, Albert; Deslous Paoli, Jean-marc; Goulletquer, Philippe; Masse, Henri; LABEIM (Laboratoire de Biologie et d'Ecologie des Invertébrés Marins). |
| En septembre 1984, MM. HERAL et DESLOUS-PAOLI organisèrent à La Tremblade, une "réunion méthodologie expérimentale mollusques". Cette rencontre faisait suite à un bref état qui s'était engagé au Congrès de Montpellier sur les "Bases biologiques de l'Aquaculture", où il était apparu que la terminologie et la méthodologie concernant le métabolisme des bivalves devaient être clarifiées. Grâce à une large information auprès des spécialistes français de la physiologie des bivalves, la réunion à La Tremblade a réuni un grand nombre de participants très motivés. Pendant 2 jours des discussions très animées ont permis de bien comprendre les échanges entre les bivalves et leur environnement et d'y jeter un regard neuf, ce qui impliquait une analyse critique du... |
| Tipo: Text |
Palavras-chave: Terminologie; Méthodologie; Bilan d'énergie; Physiologie; Bivalve; Terminology; Methodology; Energy budget; Physiology; Bivalve molluscs. |
| Ano: 1987 |
URL: http://archimer.ifremer.fr/doc/00014/12562/9432.pdf |
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| Huvet, Arnaud; Jeffroy, F; Fabioux, C; Daniel, Jean-yves; Quillien, Virgile; Van Wormhoudt, A; Moal, Jeanne; Samain, Jean-francois; Boudry, Pierre; Pouvreau, Stephane. |
| To examine further a previously reported association between amylase gene polymorphism and growth in the Pacific oyster Crassostrea gigas, ecophysiological parameters and biochemical and molecular expression levels of alpha-amylase were studied in Pacific oysters of different amylase genotypes. Genotypes that previously displayed significantly different growth were found to be significantly different for ingestion and absorption efficiency. These estimated parameters, used in a dynamic energy budget model, showed that observed ingestion rates (unlike absorption efficiencies) allowed an accurate prediction of growth potential in these genotypes. The observed association between growth and amylase gene polymorphism is therefore more likely to be related to... |
| Tipo: Text |
Palavras-chave: Ingestion; Gene expression; Bivalve; Alpha amylase. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-5165.pdf |
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| Kermorvant, Claire; Caill-milly, Nathalie; D'Amico, Frank; Bru, Noelle; Sanchez, Florence; Lissardy, Muriel; Brown, Jennifer. |
| Bivalves are important components of benthic marine and freshwater ecosystems throughout the world. One of the most exploited bivalves used for human consumption is manila clam (Venerupis philippinarum). In Arcachon Bay (SW France), commercial fishers and scientists have developed a monitoring survey to estimate clam stocks to assist in implementing a sustainable management strategy. The survey design that is currently used is based on standard stratified random sampling (StRS). The survey has been undertaken every 2 years since 2006. Each survey costs approximately (sic) 50 000, with funding provided by similar to 20% of the commercial fishers. The survey is quite expensive, given that this resource is managed mostly at a regional level. In 2016 for... |
| Tipo: Text |
Palavras-chave: Venerupis philippinarum; Bivalve; Simulation; Survey; Arcachon Bay; GRTS. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00410/52102/52808.pdf |
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| Knuckey, R; Brown, M; Robert, Rene; Frampton, D. |
| A novel technique was developed for the flocculation of marine microalgae commonly used in aquaculture. The process entailed an adjustment of pH of culture to between 10 and 10.6 using NaOH, followed by addition of a non-ionic polymer Magnafloc LT-25 to a final concentration of 0.5 mg L−1. The ensuing flocculate was harvested, and neutralised giving a final concentration factor of between 200- and 800-fold. This process was successfully applied to harvest cells of Chaetoceros calcitrans, C. muelleri, Thalassiosira pseudonana, Attheya septentrionalis, Nitzschia closterium, Skeletonema sp., Tetraselmis suecica and Rhodomonas salina, with efficiencies ≥80%. The process was rapid, simple and inexpensive, and relatively cost neutral with... |
| Tipo: Text |
Palavras-chave: Chaetoceros; Thalassiosira; Flocculation; Concentrate; Bivalve; Algal paste. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1820.pdf |
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| Lassudrie Duchesne, Malwenn; Hegaret, Helene; Wikfors, Gary H; Mirella Da Silva, Patricia. |
| Bivalves were long thought to be “symptomless carriers” of marine microalgal toxins to human seafood consumers. In the past three decades, science has come to recognize that harmful algae and their toxins can be harmful to grazers, including bivalves. Indeed, studies have shown conclusively that some microalgal toxins function as active grazing deterrents. When responding to marine Harmful Algal Bloom (HAB) events, bivalves can reject toxic cells to minimize toxin and bioactive extracellular compound (BEC) exposure, or ingest and digest cells, incorporating nutritional components and toxins. Several studies have reported modulation of bivalve hemocyte variables in response to HAB exposure. Hemocytes are specialized cells involved in many functions in... |
| Tipo: Text |
Palavras-chave: Bivalve; Harmful algal blooms (HABs); Pathogen; Hemocyte; Disease. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00612/72401/71346.pdf |
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| Lassudrie, Malwenn; Soudant, Philippe; Richard, Gaelle; Henry, N.; Medhioub, Walid; Da Silva, P.m.; Donval, Anne; Bunel, M.; Le Goïc, Nelly; Lambert, Christophe; De Montaudoin, X.; Fabioux, Caroline; Hegaret, Helene. |
| Manila clam stock from Arcachon Bay, France, is declining, as is commercial harvest. To understand the role of environmental biotic interactions in this decrease, effects of a toxic dinoflagellate, Alexandrium ostenfeldii, which blooms regularly in Arcachon bay, and the interaction with perkinsosis on clam physiology were investigated. Manila clams from Arcachon Bay, with variable natural levels of perkinsosis, were exposed for seven days to a mix of the nutritious microalga T-Iso and the toxic dinoflagellate A. ostenfeldii, a producer of spirolides, followed by seven days of depuration fed only T-Iso. Following sacrifice and quantification of protozoan parasite Perkinsus olseni burden, clams were divided into two groups according to intensity of the... |
| Tipo: Text |
Palavras-chave: Bivalve; Harmful algal bloom; Oxidative stress; Venerupis philippinarum; Alexandrium ostenfeldii; Perkinsus olseni.. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00189/30022/28507.pdf |
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| Registros recuperados: 74 | |
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