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| Registros recuperados: 65 | |
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| Boucher, Jean; Laurec, Alain; Samain, Jean-francois; Smith, S. L.. |
| The amylase and trypsin activity of the most important zooplankton species has been measured in the upwelling zone of the Spanish Sahara during the "Gibraltar ecophysiological cruise" of the oceanographic vessel Jean Charcot. The analysis of the results was carried out for the double purpose of demonstrating the regulation by the nutrition of the activities of digestive enzymes and utilizing these results to study the feeding behavior under the natural environmental conditions of an ecosystem. With regard to its biological significance, the influence of the quality and quantity of food available has been demonstrated by a bouble experimental approach followed by a statistical one. Significant correlations were found between the specific amylase activity... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1975 |
URL: http://archimer.ifremer.fr/doc/1975/publication-5105.pdf |
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| Boucher, Jean; Samain, Jean-francois. |
| The feeding of the zooplankton has been studied in the natural environment of an upwelling ecosystem by measurements of amylase and protease activities. The hypothesis of enzymatic specific activity as a nutritional index is extended by a correlation with Lorenzen's grazing index. There is no correlation between amylase and protease activity so the diet of the populations is described by the ratio of these two enzymatic activities. Variations of relative feeding rate for Calanus, Temora, Acartia, Podon, and for the total sample are discussed in relation to the ecological and trophic characteristics of the environment. |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1975 |
URL: http://archimer.ifremer.fr/doc/1975/publication-5463.pdf |
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| Boucher, Jean; Samain, Jean-francois. |
| Specific amylase activity was measured during the CINECA III cruise in the moroccan upwelling area. In this region the population is homogeneous and in a steady state during the study. The hypothesis of enzymatic activity rate as a nutrition index is enlarged by a relation with diet, fast and feeding stock. A mathematical expression is given of the relationship between zooplankton digestive activity and phytoplankton biomass. Analysis of this equation shows a daily physiological rhythm of the amylase activity. [NOT CONTROLLED OCR] |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1974 |
URL: http://archimer.ifremer.fr/doc/1974/publication-5149.pdf |
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| Boudry, Pierre; Huvet, Arnaud; Lapegue, Sylvie; Sauvage, Christopher; Tanguy, A.; Moraga, D.; Goostrey, A.; Prunet, P.; Boulo, Viviane; Gueguen, Y.; Moal, Jeanne; Fleury, Elodie; Samain, Jean-francois; Mathieu, M.; Favrel, P.. |
| Rationale for EST and genome sequencing of the Pacific oyster: its membership of the Lophotrochozoa, an little studied branch of the Eukaryotes, its worldwide aquacultural importance (4.2 million metric tons, worth 3.5 billion US dollars), its high fecundity, with concomitantly high DNA polymorphism, its use as a biosensor of coastal pollution. In 2004, an international community of biologists, the Oyster Genome Consortium (OGC) led by D. Hedgecock (University of Southern California) and uniting 70 participants from 10 countries, first presented the Pacific oyster Crassostrea gigas as a genome-sequencing candidate to Joint Genome Institute (JGI, USA) (Hedgecock et al., 2005). Besides this project (that remains to be accepted), several EST... |
| Tipo: Text |
Palavras-chave: Characteristics; Genome size; Genome; Crassostrea gigas; Oyster; Genetic. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/acte-3414.pdf |
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| David, Elise; Boudry, Pierre; Degremont, Lionel; Tanguy, Amelie; Quere, N; Samain, Jean-francois; Moraga, D. |
| Large-scale mortality events have been observed in Pacific oyster Crassostrea gigas on the west coast of France since the early 1980s, particularly during summer. In order to understand the causes of this mortality, two generations of oysters from single-pair matings were studied in three sites on the French Atlantic coast (Baie-des-Veys, Auray and Ronce-les-Bains). The present paper examines the role of two candidate genes in the susceptibility of oysters to summer mortality, and the selective pressure exerted by such mortality on their polymorphism. Glutamine synthetase (amino-acid metabolism) and delta-9 desaturase (lipid metabolism) genes were studied in the successive generations, using polymerase chain reaction single-strand conformation polymorphism... |
| Tipo: Text |
Palavras-chave: SSCP; Mortality; Glutamine synthetase; Delta 9 desaturase; Crassostrea gigas. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3040.pdf |
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| Degremont, Lionel; Bedier, Edouard; Soletchnik, Patrick; Ropert, Michel; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois; Boudry, Pierre. |
| Summer mortality has been reported in the Pacific oyster, Crassostrea gigas, for many years in different parts of the world. The causes of this phenomenon are complex. The multidisciplinary program "MOREST", coordinated by IFREMER, was initiated to understand the causes of summer mortality of Crassostrea gigas juveniles in France and to reduce its impact on oyster production. Within this program, three successive groups of bi-parental families were bred in a hatchery in 2001 and placed in the field during summer in three sites (Ronce, Riviere d'Auray, and Baie des Veys). This paper reports the relative importance of family, site and field placement timing for three characters of major importance for oyster production: survival, growth, and yield. At the... |
| Tipo: Text |
Palavras-chave: Juvenile; Crassostrea gigas; Oysters; Yield; Growth; Survival. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-1693.pdf |
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| Degremont, Lionel; Bedier, Edouard; Soletchnik, Patrick; Ropert, Michel; Samain, Jean-francois; Boudry, Pierre. |
| The French project "Morest", coordinated by IFREMER, aims to a better understanding of the causes of summer mortalities in juvenile oysters by a multidisciplinary approach. Within this program, a first generation (G1) was bred in 2001 to assess to what extent genetic variability exists for this trait in French populations. 17 half-sib families (HSF) including 44 full-sib families (FSF) were obtained in the G1, and each FSF was reared in three sites along the French coast during the summer period. Significant differences in survival were observed among HSF, clearly indicating a genetic basis for survival. Estimation of heritability for survival was very high: 0.81  0.29. In 2002, 3 "good" HSF and 3 "bad" HSF were selected on their survival... |
| Tipo: Text |
Palavras-chave: Selection; Genetic; Mortalities; Crassostrea gigas; Oyster. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3439.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; Bedier, Edouard; Ropert, Michel; Soletchnik, Patrick; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois. |
| In the scope of the Morest program, 3 series of bi-parental families of cupped oyster consisting of full and half-sib have been created in 2001, and then studied on a regular basis on several sites over the summer period. In October, major survival differences had been demonstrated between the 3 families. The average survival rate for the half-sib families monitored on the three sites varies from 17 to 97 %. Some of them showed high mortality for the three sites, indicating a strong genetic basis (h2 = 0.81 - 0.29) to the variations observed regarding survival. To a lesser extent, growth differences between the studied half-sib families indicate a weaker heritability for this character. .... |
| Tipo: Text |
Palavras-chave: Physiologie; Génétique; Naissain; Sélection; Croissance; Survie; Huîtres; Crassostrea gigas. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3490.pdf |
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| Degremont, Lionel; Boudry, Pierre; Ropert, Michel; Samain, Jean-francois; Bedier, Edouard; Soletchnik, Patrick. |
| This study investigated the effects of age (first or second summer of life) and environment (three study sites on French coasts) on summer mortality in Crassostrea gigas, using three generations of oysters produced during the Morest project. For each generation, two groups of oysters, selected either as 'resistant' (R) or 'susceptible' (S) to summer mortality at the age of 6 months in Rivière d'Auray (RA, South Brittany), were evaluated. In Ronce (Marennes-Oléron Bay) and RA, R oysters had low mortality during their first and second summers, while mortality was higher during the second summer in Baie des Veys (BDV, Normandy). In RA, S oysters exhibited higher mortality during their first summer than during their second, while the opposite result was found... |
| Tipo: Text |
Palavras-chave: Summer mortality; Age; Environment; Genetic; Crassostrea gigas. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6972.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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| 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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| Delaporte, Maryse; Chu, Fu-lin; Langdon, Chris; Moal, Jeanne; Lambert, Christophe; Samain, Jean-francois; Soudant, Philippe. |
| The aim of this study was to assess the effect of dietary eicosapentaenoic acid (20:5n-3) on hemocyte parameters such as hemocyte concentration, phagocytosis, and non-stimulated reactive oxygen species (ROS) production in Pacific oysters Crassostrea gigas, as well on proximate biochemical and fatty acid compositions. One-year-old oysters (C. gigas) were fed T-Isochrysis aff. galbana(T-Iso), which is low in 20:5n-3, either alone or with supplements of a lipid emulsion rich in 20:5n-3 at 1%, 10% or 50% (dry weight of the algal ration) for up to 7 weeks. Changes in gill fatty acid composition demonstrated that the lipid emulsion was well ingested by oysters during the dietary conditioning. Biochemical analysis indicated that oysters fed supplements of 50%... |
| Tipo: Text |
Palavras-chave: Polyunsaturated fatty acids; Immunology; Hemocytes; Eicosapentaenoic acid 20 : 5n 3; Crassostrea gigas; Bivalves. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2604.pdf |
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| Delaporte, Maryse; Soudant, P; Lambert, C; Jegaden, M; Moal, Jeanne; Pouvreau, Stephane; Degremont, Lionel; Boudry, Pierre; Samain, Jean-francois. |
| Within the framework of a national scientific program named "MORtalites ESTivales de l'huitre creuse Crassostrea gigas" (MOREST), a family-based experiment was developed to study the genetic basis of resistance to summer mortality in the Pacific oyster, Crassostrea gigas. As part of the MOREST project, the second generation of three resistant families and two susceptible families were chosen and pooled into two respective groups: "R" and "S". These two groups of oysters were conditioned for 6 months on two food levels (4% and 12% of oyster soft-tissue dry weight in algal dry weight per day) with a temperature gradient that mimicked the Marennes-Oleron natural cycle during the oyster reproductive period. Oyster mortality remained low for the first two... |
| Tipo: Text |
Palavras-chave: Summer mortality; Reproduction; Reactive oxygen species ROS; Hemocyte parameters; Genetic selection; Crassostrea gigas. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3578.pdf |
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| Delaporte, Maryse; Soudant, P; Lambert, C; Moal, Jeanne; Pouvreau, Stephane; Samain, Jean-francois. |
| The aim of this study was to test the effect of food quantity on energy storage and defense capacities of oysters during a reproductive cycle. One-year-old Crassostrea gigas oysters were fed two different dietary rations (4% and 12% of oyster dry weight in algal dry weight per day) in controlled experimental conditions over an annual cycle. Oyster dry weights, carbohydrate and lipid contents, energetic adenylate charge, and hemocyte parameters of oysters were significantly affected by reproductive processes related to seasonal temperature variation and, to a lesser extent, by the dietary rations. Energy parameters decreased during gametogenesis as gonads developed then increased during the gonad resorption phase. The additional energy provided to oysters... |
| Tipo: Text |
Palavras-chave: Reactive oxygen species production; Reproduction; Phagocytosis; Hemocyte parameters; Energy storage; Crassostrea gigas. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1549.pdf |
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| Delaporte, Maryse; Soudant, Philippe; Moal, Jeanne; Giudicelli, Emilie; Lambert, Christophe; Seguineau, Catherine; Samain, Jean-francois. |
| Arachidonic acid (20:4n-6, ArA) and its eicosanoid metabolites have been demonstrated to be implicated in immune functions of vertebrates, fish, and insects. Thus, the aim of this study was to assess the impact of ArA supplementation on the FA composition and hemocyte parameters of oysters Crassostrea gigas. Oyster dietary conditioning consisted of direct addition of ArA solutions at a dose of 0, 0.25, or 0.41 mu g ArA per mL of seawater into tanks in the presence or absence of T-Iso algae. Results showed significant incorporation of ArA into gill polar lipids when administered with algae (up to 19.7%) or without algae (up to 12.1%). ArA supplementation led to an increase in hemocyte numbers, phagocytosis, and production of reactive oxygen species by... |
| Tipo: Text |
Palavras-chave: Hemocyte parameters; Oyster immunity; Arachidonic Acid; Poly unsaturated fatty acids; Nutrition; Bivalve; Crassostrea gigas. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1876.pdf |
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| Delaporte, Maryse; Soudant, Philippe; Moal, Jeanne; Lambert, Christophe; Quere, Claudie; Miner, Philippe; Choquet, Gwenaelle; Paillard, Christine; Samain, Jean-francois. |
| The impact of diets upon the fatty acid composition of haemocyte polar lipids and consequently upon immune parameters has been tested in the oyster Crassostrea gigas and the clam Ruditapes philippinarum. Oysters and clams were fed each of three cultured algae: Chaetoceros calcitrans, which is rich in 20:5(n-3) and 20:4(n-6) and poor in 22:6(n-3) fatty acids; T-Iso (Isochrysis sp.), which is rich in 22:6(n-3) and deficient in 20:5(n-3) and 20:4(n-6); and Tetraselmis suecica, which is deficient in 22:6(n-3) and contains only small amounts of 20:5(n-3) and 20:4(n-6). Fatty acid composition of haemocyte polar lipids was greatly affected by the diet. Oysters and clams fed C. calcitrans maintained a higher proportion of 20:5(n-3) and 20:4(n-6) in their haemocyte... |
| Tipo: Text |
Palavras-chave: Ruditapes philippinarum; Crassostrea gigas; Polyunsaturated fatty acids; Phagocytosis; Oxidative activity; Haemocyte membrane; Nutrition; Immunology; Bivalve; Immunologie; Bivalve; Ruditapes philippinarum; Crassostrea gigas; Acides gras poly insatures; Phagocytose; Flambee respiratoire; Membrane; Hemocyte; Nutrition. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-354.pdf |
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| Gagne, Renee; Tremblay, Rejean; Olivier, Frederic; Pernet, Fabrice; Miner, Philippe; Samain, Jean-francois. |
| Through biological flume experiments, we studied the effect of shear velocity and attachment period on the percent detachment of Pecten maximus post-larvae of different sizes reared on two experimental diets. The first diet, (Pavlova lutheri, Isochrysis galbana, Chaetoceros calcitrans), which served as a reference diet (PTC), is commonly used in bivalve hatcheries; the second is the PTC diet with the addition of Rhodomonas salina (PTCR). Our results indicate that the detachment of post-larvae fed PTCR diet showed significant interactions between scallop length, attachment period and shear stress, while the post-larvae feed with the PTC diet showed only effect of shear stress factor. Furthermore, post-larvae exposed to various flume velocities showed... |
| Tipo: Text |
Palavras-chave: Attachment; Pecten maximus; Benthic boundary layer; Flume; Diet. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00111/22219/20056.pdf |
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| Registros recuperados: 65 | |
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