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| Registros recuperados: 65 | |
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| Moal, Jeanne; Samain, Jean-francois; Le Coz, Jean-rene; Daniel, Jean-yves. |
| Crassostrea gigas oysters cultivated in Marennes-Oleron Bay (France), face seasonal variations in the environment: salinity, turbidity, phytoplanktonic production, and the tidal rhythm of emersion. The oysters are maintained at different depths to reduce competition for space (e.g. by settlement of mussel spat). The physiological responses of two groups of oysters to different periods of emersion were studied using a seasonal sampling strategy: one group was on a flat part of the area, and the effect of emersion was studied in a short time survey (less than three hours emersion at low tide); the other was located in a very narrow place with a steep slope. This group was subdivided into three, according to bathymetric position, to study the long term effect... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Physiology; Emersion; AEC; Digestive enzimes; Marennes-Oleron Bay. |
| Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/00038/14885/12208.pdf |
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| Degremont, Lionel; Boudry, Pierre; Soletchnik, Patrick; Bedier, Edouard; Ropert, Michel; Samain, Jean-francois. |
| Three successive generations were produced between 2001 and 2003 to assess to what extent genetic variability exists for survival in juvenile oysters Crassostrea gigas. For each generation, two groups were selected for their high ("R" for resistant) and low ("S" for susceptible) survival. Significant differences in mortality were observed during the first year in Riviere d'Auray (RA) (Brittany-France). However, low and similar mortality were observed for both groups, with no significant difference between groups in the first and second generation in this site, where the first summer is the critical, sensitive period with a clear age effect. In Baie des Veys (BDV) (Normandie-France), where mortalities usually mainly affect adults, mortality between groups,... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Spat; Spatial variations; Survival; Rearing; Mollusc culture; Marine molluscs; Environmental factors; Nursery grounds; Mortality causes; Biological age; Aquaculture techniques. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3385.pdf |
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| Huvet, Arnaud; Degremont, Lionel; Labreuche, Yannick; Daniel, Jean-yves; Dubrunfaut, Thomas; Boudry, Pierre; Haure, Joel; Bedier, Edouard; Ropert, Michel; Herpin, Amaury; Cunningham, Charles; Moal, Jeanne; Samain, Jean-francois. |
| Summer mortality associated with juveniles of the oyster Crassostrea gigas is the result of a complex interaction between the host, pathogens and environment. Divergent selection based on summer survival have been applied to produce families with resistant and susceptible progeny. Here, we describe the use of suppression subtractive hybridization to generate 150 clones that were differentially regulated between resistant and susceptible F2 progeny. The nucleotide sequence of these 150 clones was determined. Among the 25 unique sequences that matched with the products of known genes, those putatively implicated in energy generation (12%) and immune function (16%), systems suspected to be implicated in summer mortality, were extended and analyzed by real... |
| Tipo: Text |
Palavras-chave: Selection; Gene; Genetic; Summer mortality; Crassostrea gigas; Pacific oysters. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3447.pdf |
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| Degremont, Lionel; Boudry, Pierre; Bedier, Edouard; Ropert, Michel; Soletchnik, Patrick; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois. |
| The French project "Morest", coordinated by IFREMER, aims to understand the causes of the summer mortalities in Crassostrea gigas. In 2001, three sets of families were bred following a nested half-sib mating design. 17 half-sib families (HSF) were obtained in this first generation (G1) and reared in 3 sites. Significant differences in survival were observed among HSF, and some HSF showed high levels of mortality in all sites, clearly indicating a genetic basis for survival. In 2002, a second generation (G2), including divergent selection and inbred lines, was constituted. Monitoring of survival and growth of G2s were the same as in 2001. Significant differences in survival were found between the offspring of the "high" and "low" selected groups and between... |
| Tipo: Text |
Palavras-chave: Summer; Oyster culture; Juveniles mortality; Genetics; Commercial species; Breeding. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3346.pdf |
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| Degremont, Lionel; Boudry, Pierre; Soletchnik, Patrick; Bedier, Edouard; Ropert, Michel; Samain, Jean-francois. |
| Three successive generations were produced between 2001 and 2003 to assess to what extent genetic variability exists for this trait in juvenile oysters Crassostrea gigas. For each generation, two groups were selected for their high ("R" for resistant) and low ("S" for susceptible) survival. Significant differences of mortality were observed during the first year in Rivière d'Auray (RA) (Brittany-France). However, low and similar mortality were observed for both groups, with no significant difference between groups in the first and second generation in this site, where the first summer is the critical sensitive period with a clear age effect. In Baie des Veys (BDV) (Normandie-France), where mortalities usually mainly affect adults, mortality between... |
| Tipo: Text |
Palavras-chave: Genetic variability; Genetic; Summer mortality; Crassostrea gigas; Pacific oysters. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/acte-3442.pdf |
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| Gagne, Renee; Tremblay, Rejean; Pernet, Fabrice; Miner, Philippe; Samain, Jean-francois; Olivier, Frederic. |
| The main objective of this study was to evaluate the effect of the addition of Rhodomonas salina in the diet of Pecten maximus on growth, survival and metamorphosis success in relation to biochemical content. Food quality is an essential factor in the success of larval, post-larval and juvenile development. A diet rich in polyunsaturated fatty acids present an advantage for growth, survival and metamorphosis success. Larvae and post-larvae fed with the diet containing R. sauna showed a higher accumulation of arachidonic acid (20:4n-6) and generally a lower concentration of docosahexaenoic acid (22:6n-3). Addition of R. sauna in diet was related with higher level of eicosapentaenoic acid (20:5n-3) in larval stages, but lower level in post-larvae. Addition... |
| Tipo: Text |
Palavras-chave: Nutrition; Biochemical characteristics; Fatty acids; Sterol profiles. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00019/13045/10205.pdf |
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| Huvet, Arnaud; Jeffroy, Fanny; Daniel, Jean-yves; Quere, Claudie; Le Souchu, Pierrick; Van Wormhoudt, A.; Boudry, Pierre; Moal, Jeanne; Samain, Jean-francois. |
| In the oyster Crassostrea gigas consumption-related traits, amylase properties and growth were found to be linked through genotypes that differed for polymorphism in the two amylase genes AMYA and AMYB. Modulation of AMYA mRNA level had already been observed in response to food availability, whereas the functional role of AMYB was still unknown. To improve knowledge about the regulation of amylase expression in C. gigas and the respective roles of the two genes, we made an assay of amylase expression at mRNA and enzymatic levels in the digestive gland of oysters that had received dietary supplements of starch. After 18 days, a significant increase of translatable mRNA for AMYB was observed, with a correlated increase in Michaelis-Menten constant Km values... |
| Tipo: Text |
Palavras-chave: Alpha-amylase; Crassostrea gigas; Digestive enzyme; Michaelis-Menten constant; Regulation. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00087/19869/17521.pdf |
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| Samain, Jean-francois; Ropert, Michel; Bedier, Edouard; Soletchnik, Patrick; Mazurie, Joseph; Le Coz, Florence; Blin, Jean-louis; Mille, Dominique; Pajot, Régis; Haffray, Patrick; Bacher, Cedric; Grangere, Karine; Grangere, Karine; Pouvreau, Stephane; Bourles, Yves; Gohin, Francis; Woerther, Patrice; Boudry, Pierre. |
| Summer mortality has been reported in the Pacific oyster, Crassostrea gigas, for many years in Japan, US and Europe. It affects both adults and juveniles and the causes of this phenomenon are complex. Environmental, physiological or pathological putative causes were studied all over the world. Recently, the MOREST project ((MORtalitEStivale) a multidisciplinary project (2001-2005) focused on his problem led to a better understanding of this phenomenon in France. The results showed in these geographical conditions, the main interactions between the oysters, their environment and certain pathogens. |
| Tipo: Text |
Palavras-chave: Interaction model; Environmental parameters; Summer mortality; Crassostrea gigas; Pacific oyster. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/2006/acte-3476.pdf |
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| Soletchnik, Patrick; Ropert, Michel; Bedier, Edouard; Costil, K. S.; Dubois, Brice; Degremont, Lionel; Bouget, Jean-francois; Martin, Jean-louis; Enriquez-diaz, M.; Faury, Nicole; Le Moine, Olivier; Renault, Tristan; Gagnaire, Beatrice; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois. |
| Field characterization of summer mortality was performed in France in the frame of the Morest project. Natural and hatchery spat were compared between three oyster production areas in France. Regardless of the natural or hatchery origin, oysters died during the reproduction period after temperature reaches 19 degree C. Thus, in southern areas, temperature accelerated gametogenesis of small spat (10mm) as well as adults, and mortality appeared for the two age classes. In contrast, sexual maturation proceeded more slowly in northern where spat mortality was lower compared to 18 months old oysters. However, critical gametogenesis and temperature were not sufficient to induce mortalities, as observed in examples with stable environment. Alternatively sediment... |
| Tipo: Text |
Palavras-chave: Seasonal variation; Oyster culture; Mortality causes; Hatcheries; Gametogenesis; Environmental factors; Crassostrea gigas; Oysters. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3348.pdf |
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| Seguineau, Catherine; Soudant, P; Moal, Jeanne; Delaporte, Maryse; Miner, Philippe; Quere, Claudie; Samain, Jean-francois. |
| The present study tested two techniques for dietary supplementation of Crassostrea gigas spat with PUFA, such as arachidonic acid (AA). The first technique consisted of a preliminary enrichment and growth of an algal concentrate (T-ISO, Isochrysis sp.) with AA dissolved in an ethanol solution, the whole culture then being fed to the spat. This enrichment increased the AA weight percentage in T-ISO neutral and polar lipids from 0.6 to 22.4% and from 0.4 to 6.8%, respectively. The second delivery technique was direct addition separately of free AA dissolved in ethanol solution and algal concentrate (T-ISO + AA) to the spat-rearing tank. To test the efficiency of these delivery techniques, oyster spat were supplemented with AA-enriched T-ISO, T-ISO + AA, and... |
| Tipo: Text |
Palavras-chave: Food supply; Arachidonic acid; Spat; Crassostrea gigas; Dietary. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-1094.pdf |
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| Samain, Jean-francois; Moal, Jeanne; Alayse-danet, Anne-marie; Daniel, Jean-yves; Le Coz, Jean-rene. |
| Model for Rapid Detection of Sublethal Effects of Pollutants. II. An in situ Example: Anomalous Metabolism of the Hyponeustonic Copepod Anomalocera patersoni Coinciding with an Oil Spill An unusual correlation has been obsemed between the amylase and trypsin content of a natural zooplankton population and of the hyponeustonic copepod Anomalocera patersoni and the oil spill of the "Amoco Cadiz" in 1978. This anomaly has also been obsewed in Artemia sp. cultures (San Francisco Bay strain) poisoned by copper. This phenomenon could originate from a general physiological perturbation. Such a non-specific perturbation could explain the anormal correlation between parameters which are usually independent and specifically regulated. The determination of such... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/1981/publication-5362.pdf |
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| Jacq, E; Moal, Jeanne; Samain, Jean-francois; Corre, S; Daniel, J; Nicolas, Jean-louis; Cochard, Jean-claude; Fera, P. |
| Larval rearings were performed with seawater either freshly pumped or after storage in a pond. Concerning bacterial populations these waters were characterized by a high diversity, little sized bacteria whose few of them (1%) were cultivable on Zobell medium. In the tanks, the bacterial ecosystem was modified by the presence of antibiotics, larvae and algae: the diversity was lowered, the cellular volume was increased by a factor 2 to 5, 100% bacteria were cultivable and chloramphenicol resistant, and their metabolism changed. Taxonomic screening showed no differences among the two waters neither at the beginning nor at the end of the rearings. However, depending on the water (stored or not) differences were identified for bacterial physiology and... |
| Tipo: Text |
Palavras-chave: Marine aquaculture; Pond culture; Scallop culture; Ecology; Antibiotics; Organic matter; Grazing; Carbohydrates; Mathematical models; Modelling; Growth; Bacterial diseases; Biological production; Culture tanks; Larvae; Rearing. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-914.pdf |
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| Palacios, Elena; Racotta, I; Kraffe, E; Marty, Y; Moal, Jeanne; Samain, Jean-francois. |
| Seasonal variations in fatty acid composition in several tissues of a 1-year-old population of giant lion's-paw scallop Nodipecten subnodosus were analyzed during gonad development. Samples were taken bimonthly from December 1999 to June 2000, a period in which gonad development was occurring. Fatty acid accumulation in neutral and polar lipids of the female gonad was concomitant to the gonad development and presented a maximum in June. Among essential fatty acids, a specific accumulation was observed only for 20:5n - 3 in the female gonad, as suggested by an increase in its proportion in the neutral and the polar fractions. However, no specific accumulation was observed for 22:6n - 3, as its proportion remained relatively constant in both fractions. We... |
| Tipo: Text |
Palavras-chave: Reproduction; Pectinidae; HUFA; EPA; DHA; Arachidonic acid. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-767.pdf |
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| Lambert, Christophe; Soudant, Phillippe; Degremont, Lionel; Delaporte, Maryse; Moal, Jeanne; Boudry, Pierre; Jean, Frédéric; Huvet, Arnaud; Samain, Jean-francois. |
| High variability among individuals is often encountered when hemocyte characteristics are measured in bivalves. Such variability is suspected to result partly from genetic factors. In this study, hemocyte characteristics of six families of Crassostrea gigas were compared by flow cytometry at one sampling date in October 2001. These families were obtained from a nested, half-sibling cross design, and reared from July to October 2001 at three sites distributed along the French Atlantic coast from north to south: Baie des Veys (Normandy), Riviere d'Auray (Brittany) and Ronce (Marennes-oleron Basin, Poitou Charentes). Among the 15 measured hemocyte characteristics, production of reactive oxygen species (ROS) of untreated hemocytes (maintained in filtered... |
| Tipo: Text |
Palavras-chave: Genetic; Flow cytometry; Reactive oxygen species ROS; Adhesion; Hemocyte; Crassostrea gigas; Summer mortality. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3054.pdf |
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| Samain, Jean-francois; Moal, Jeanne; Daniel, Jean-yves; Le Coz, Jean-rene. |
| The ingestion rate and the resulting assimilation calculated by means of a law taking into account activities of the digestive enzymes (amylase and trypsin) on the carbohydrates and proteins ingested, are determined in two experiments on Artemia. They are fed the same species of phytoplankton (Tetraselmis suecica), at the same concentration but with two chemical compositions. In one experiment, the cells are rich in carbohydrates and poor in proteins, and in the second one they are poor in carbohydrates, rich in proteins. Different observed ingestion rates induce a balance in proteins, and a large difference in the carbohydrates ingested. When digestive enzymes are taken into account, the assimilated carbohydrates and proteins are similar (explaining the... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/1981/publication-5360.pdf |
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| Samain, Jean-francois; Boucher, Jean; Buestel, Dominique; Borne, M.; Le Coz, Jean-rene. |
| The relations between the activity of the digestive enzymes amylase and proteases were studied on Artemia salina L. For this purpose, a method for measuring the ingestion was developed compatible with the speed of response of the digestive enzymes. It is demonstrated that the proteic density variations in Artemia of the same size are in relation to the food content of their digestive tract. Therefore the measurement of the size and weight of proteins (proteic density) allows the evaluation of the ingestion. With the aid of this method, a daily ingestion rhythm, with bimodal character, could be demonstrated. The influence on the ingestion, of the concentration of food available (Tetraselmis suecica Butcher) was studied in function of the size of the... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1975 |
URL: http://archimer.ifremer.fr/doc/1975/publication-5104.pdf |
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| Registros recuperados: 65 | |
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