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| Registros recuperados: 136 | |
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| Prudence, Marie. |
| Two amylase genes, A and B, from the oyster Crassostrea gigas were characterized. Using PCR-RFLP, 6 and 4 alleles, respectively, were described for the amylase genes A and B. The roles of A and B amylase genes were investigated experimentally. They are expressed during larval and adult stages, and A transcripts are more abundant than B. The A transcript increases significantly with temperature, in high trophic conditions. However, A and B transcript levels do not change when food quantity increases although amylase activity augments. The level of B is correlated with dietary starch quantities, whereas the amount of A appears to remain constant ; simultaneously amylase activity decreases and the KM increases. These results suggest that expression of B is... |
| Tipo: Text |
Palavras-chave: Enzymatic analyse; Genetic polymorphism; Genes; Nutrition; Growth; Environmental effects; Oysters; Amylases; Amylases; Analyse enzymatique; Polymorphisme génétique; Gènes; Nutrition; Croissance; Effets de l'environnement; Huîtres; Amylases; Amylases. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/these-1700.pdf |
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| Haberkorn, Hansy; Lambert, Christophe; Le Goic, Nelly; Quere, Claudie; Bruneau, A; Riso, Ricardo; Auffret, Michel; Soudant, Philippe. |
| Effects of simultaneous exposure of Pacific oyster, Crassostrea gigas, to both a harmful dinoflagellate that produces Paralytic Shellfish Toxins (PST), Alexandrium minutum, and cadmium (Cd) and copper (Cu), were assessed. Oysters were exposed to a mix of Cd-Cu with two different diets (i.e. A. minutum or Tisochrysis lutea) and compared to control oysters fed A. minutum or T. lutea, respectively, without metal addition. Metals and PST accumulations, digestive gland lipid composition, and cellular and biochemical hemolymph variables were measured after 4 days of exposure. Oysters exposed to Cd-Cu accumulated about thirty-six times less PSTs than oysters exposed to A. minutum alone. Exposure to Cd-Cu induced significant changes in neutral lipids (increase in... |
| Tipo: Text |
Palavras-chave: Harmful algae; Metals; Oysters; Toxin accumulation; Physiological effects. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00169/28071/26286.pdf |
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| Gonzalez-fernandez, Carmen; Tallec, Kevin; Le Goic, Nelly; Lambert, Christophe; Soudant, Philippe; Huvet, Arnaud; Suquet, Marc; Berchel, Mathieu; Paul-pont, Ika. |
| While the detection and quantification of nano-sized plastic in the environment remains a challenge, the growing number of polymer applications mean that we can expect an increase in the release of nanoplastics into the environment by indirect outputs. Today, very little is known about the impact of nano-sized plastics on marine organisms. Thus, the objective of this study was to investigate the toxicity of polystyrene nanoplastics (NPs) on oyster (Crassostrea gigas) gametes. Spermatozoa and oocytes were exposed to four NPs concentrations ranging from 0.1 to 100 mg L−1 for 1, 3 and 5 h. NPs coated with carboxylic (PS-COOH) and amine groups (PS-NH2) were used to determine how surface properties influence the effects of nanoplastics. Results demonstrated the... |
| Tipo: Text |
Palavras-chave: Nanoplastics; Oysters; Gametes; Cellular responses. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00443/55459/56976.pdf |
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| Fleury, Pierre-gildas; Mazurie, Joseph; Ropert, Michel; Soletchnik, Patrick; Le Coz, Florence. |
| The wide range of data from the French Ifremer/REMORA network, collected since 1993 allow a global characterization of mortalities of 1-year old and 2-years old cupped oysters Crassostrea gigas, that are cultivated in the main French oyster areas (Fleury et al, 2003), and thus a better understanding of the causes of these mortalities (Ifremer /MOREST project). The average annual mortalities on intertidal sites range from 10 to 20%. Most of the mortalities take place in Spring and Summer. 1-year oyster mortalities occur in Marennes and several sites in Brittany whilst 2-years oyster mortalities occur in the same sites and in baie des Veys (Normandy). In addition, 2-years oyster mortalities appear more variable according to different annual surveys.... |
| Tipo: Text |
Palavras-chave: Meteorolgical factors; Phytoplankton; REMORA; Mortalities; Oysters; Crassostrea gigas. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/acte-4547.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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| Goulletquer, Philippe; Heral, Maurice; Prou, Jean. |
| Oyster landings in the Maryland portion of the Chesapeake Bay have declined by more than 50fold since the early part of the century, despite intensive management efforts. The annual shell repletion program is the most critical programmatic element to effect recovery of the ailing Eastern oyster Crassotrea virginica stock and fishery. The overall efficacy of shell repletion management depends primarily on the success of spat settlement on the planted shell, and furthermore on their survival rate. The Operations Research techniques and mathematical programming developed by Rothschild et al. (1991) attempt to maximize spat recruitment to the oyster stock subject to a series of operational constraints. Allocation and timing of shell deployment are the most... |
| Tipo: Text |
Palavras-chave: Larval; Settlement; USA; Chesapeake Bay; Crassotrea virginica; Oysters. |
| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/1994/publication-3074.pdf |
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| Heral, Maurice; Robert, Jean-michel; Truquet, Isabelle; Barbaroux, Olivier; Garnier, Jacqueline; Razet, Daniel. |
| Values of nitrogen nutrients (ammonia, nitrite and nitrate) are compared with values of total organic nitrogen and urea. In summer, the consumation by micro and macrophytes is added to less important telluric input of nineral nitroge. However, an important provision of organic nitrogen remains. On the contrary, in winter, organic nitrogen does not represent more than 10% of total nitrogen. The autors postulate that populations of oysters are at the starting point of the organic nitrogen production cycle. |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Biochimical composition; Oysters; Crassostrea gigas; Composition biochimique; Huîtres. |
| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/1981/acte-2940.pdf |
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| Registros recuperados: 136 | |
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