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Registros recuperados: 858 | |
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Arnaud, Christophe; Fillon, Alain. |
The Charente-Maritime coast has, on its northern part, between the Charente estuary and the northern boundary of the department (Isle of Ré included), many sites which interest the oyster culture industry, especially as far as juvenile collection is concerned. The well-known centre of Fouras is one of them. To help the professionals, and for its own purposes, the Ifremer studies the periods of emission of cupped oyster larvae in order to let the oyster farmers know about the best collection times. Contractualized for the first time in 1996 between the SRC FIE-Centre Ouest and the Ifremer, this work has been carried out again in 1997 by the DEL coastal laboratory of La Rochelle, following the renewal of this contract. This report presents the different... |
Tipo: Text |
Palavras-chave: Captage; Marennes Oléron; Crassostrea gigas; Larves; Reproduction. |
Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/1998/rapport-6568.PDF |
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Couty, Angélique. |
The Japan oyster: Crassostrea gigas have been imported on the french coasts in the seventies and from this time it adapted to this environment. Since, it became the main oyster producted in France. But ,since twenty years C. gigas presents an anormaly and important mortality eah year in the period of summer. The syndrome known as summer mortality, appears particulary in mid-june. This mortality can affected 50% of the culture. Many studies have brought elements in the comprehension of the condition of apparition of this mortalilities. Temperature seems to play an important rule with reproductive maturation. But also, the deep ofwater could be associated to this mass mortality. The study began in march 2003 and characterize more precisely the summer... |
Tipo: Text |
Palavras-chave: Crassostrea gigas; Mortalité estivale; Croissance; Maturation; Environnement; Crassostrea gigas; Summer mortality; Growth; Maturation; Environment. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00306/41767/40980.pdf |
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Deslous-paoli, Jean-marc; Zanette, Yvan; Heral, Maurice; Masse, Henri; Garnier, Jacqueline. |
The breeding of Pacific oysters Crassostra gigas, in non tidal ponds, before commercialization, brings about an improvement of the shell and of the quantity and quality of the tissues. In fact, the Berthome's indice (1978) moves from 1.36 in June to 0.68 December, and the density of the shell increases in the same time from 1.79 to 1.98. On the other hand, the percentage of tissues in the oyster is 12.4% at the end of gametogenesis and more than 9% at the end of breeding. The dry tissues are composed of 10.3 of ash, 40.3% of proteins, 12.6% of lipids and 9% of carbohydrate. 95% of the carbohydrate are glycogen. The resulting energetic values are measured to 5.10 cal-mg super(-1) of dry tissues ash free. |
Tipo: Text |
Palavras-chave: Crassostrea gigas; Tissues; Biochemical composition; Shells; Growth; Oyster culture. |
Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/1981/publication-1892.pdf |
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Pouvreau, Stephane; Maurer, Daniele; Auby, Isabelle; Soletchnik, Patrick; Mille, Dominique; Bernard, Ismael; Bedier, Edouard. |
In France, spatfall of Pacific Oysters occurs traditionally in two shellfish area of the south west of France: the Marennes-Oléron bay and the Arcachon basin. The spat collected in both sites ensures approx. 70 % of the need of the French oysters production (the other part is produced in hatcheries). But, since ten years, recruitment have become highly variable especially in Arcachon basin. For instance, in this site, spatfall (assessed at the end of the reproductive season) can vary between 50 oysters per collector to more than 20 000 oysters per collector (Figure 1). This huge variation arise questions from oysters producers and the French National Committee for Shellfish Culture want to get some explanations of the phenomenon. It is well known that... |
Tipo: Text |
Palavras-chave: Larvae; Reproduction; Recruitment; Spatfall; Crassostrea gigas. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/acte-4543.pdf |
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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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Bacher, Cedric. |
A model of the growth of cultivated oyster in the Marennes-Oléron bay was developped to assess the influence of the nutrients input and of the amount of oysters on the growth performance (Railiard. 1991). The ecosystem main characteristics are: - short residence time of the water. - high turbidity level, depending on the season, tidal level, bathymetry, currents and wind. The turbidity acts on the primary production through light limitation and on oyster production as a food dilution factor. - presence of high density cultivated areas on mid-tidal flats. The amount of oysters is ranging between 80 000 and 110 000 tons according to the year. - spatial variability of the biological and physical features. - coupling effects of the physic process (transport,... |
Tipo: Text |
Palavras-chave: Ecosystem model; Oyster; Crassostrea gigas; Nitrogen cycling; Marennes Oleron Bay; Charente Maritime. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00102/21300/18914.pdf |
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Pepin, Jean-francois; Riou, Antoine; Renault, Tristan. |
Herpes and herpes-like virus infections have been reported in various marine mollusc species associated with high mortality rates. Following the characterisation and genome sequencing of ostreid herpesvirus 1 (OsHV-1), specific diagnostic tools have been developed based on conventional PCR techniques or in situ hybridisation. We have now developed a real-time PCR assay for rapid, sensitive and quantitative detection of OsHV-1, and compared it with a conventional PCR technique described previously. The new assay utilised SYBR® Green chemistry with specific primers C9/C10 targeting the C region, which is present in two copies in the OsHV-1 genome and encodes two proteins of unknown function. The assay was applied successfully to rapid diagnosis (100 minutes)... |
Tipo: Text |
Palavras-chave: Crassostrea gigas; PCR; Oyster; OsHV 1; Detection; Herpes virus 1. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/acte-3653.pdf |
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Labreuche, Yannick; Soudant, Philippe; Goncalves, Madeleine; Lambert, Christophe; Nicolas, Jean-louis. |
Vibrio aestuarianus strain 01/32 was previously shown to be pathogenic to Crassostrea gigas juveniles. To investigate virulence mechanisms of this pathogen, we studied the toxicity to oysters of its extracellular products (ECPs). ECPs displayed lethality to animals, with a LD50 value of 3.3 mu g/g body weight. To determine the oyster cellular immune responses induced by these ECPs, we further examined in vitro their effects on C. gigas hemocytes, using flow cytometric-based hemocyte assays. Treatment of hemolymph with ECPs caused a significant inhibition of hemocyte phagocytosis and adhesive capabilities. In contrast, the pathway of reactive oxygen species production was enhanced by higher ECP concentrations. Exposure of hemocytes to live bacteria induced... |
Tipo: Text |
Palavras-chave: Vibrio aestuarianus; ECPs; Crassostrea gigas; ROS production; Adhesion; Phagocytosis; Flow cytometry; Bivalve immunity. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1035.pdf |
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Barille, Laurent; Prou, Jean. |
Ecophysiological experiments conducted in situ in the Bay of Marennes-Oléron during a spring and neap tide cycle in May 1991 , were designed to get a better representation of 2 important components of the energy budget of the Japanese oyster Crassostrea gigas : clearance rate and selection efficiency. The relationships previously established by Raillard et al. ( 1993) are re-evaluated by integrating the effects of high seston loads, typical of tidal effect within estuaries, on the physiological processes. For the clearance rate, the re-evaluated parameterization includes: - a negative effect of turbidity. - a clogging threshold set to 192 mg/l. Selection efficiency parameterizations are modified by incorporating : - a constant inorganic ingestion for... |
Tipo: Text |
Palavras-chave: Matematical model; Oyster; Crassostrea gigas; Clearance rate; Seclection efficency; Marennes Oleron; Charente Maritime. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00102/21299/18913.pdf |
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Sauriau, Pierre-guy; Bacher, Cedric. |
Stock assessement of wild soft-bottom mol/uses has been part of a general approach to shellfish management in oyster farming in Marennes-Oleron Bay. A sampling survey is described as a stratified random sampling after optimum allocation of the sample sire in each stratum. The aim of this study is ta ilIustrate the use of kriging techniques in the case of suspension-feeders. Regarding suspension-feeding molluscs. trophic competitors of the oyster Crassostrea gigas the whole stratified design produced an estimation with a precision around 25%. Then the geostatistical technique. i.e. kriging was used to depict the spatial and variability patterns of several trophic groups. The biomass data are expressed in ash-free. dry-weight units. In addition, the... |
Tipo: Text |
Palavras-chave: Marennes Oléron; Crassostrea gigas; Krigeage; Suspensivore; Echantillonnage stratifié; Peuplement benthique. |
Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/1991/publication-3055.pdf |
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His, Edouard. |
L'introduction d'une nouvelle espèce en ostréiculture donne souvent lieu à des débats passionnés dans les milieux ostréicoles. Un exemple est donné par Charles Martin, parqueur du Bassin d'Arcachon, dans son ouvrage "Agriculteur de la mer"; il rapporte les mesures restrictives qu'avait entraînées l'introduction de l'huître portugaise à Arcachon au début du 20ème siècle. Un des arguments avancés pour expliquer les réticences était celui de la "concurrence vitale" et de la compétition sur le plan nutritionnel (filtration) entre C. angulata et Ostrea edulis: cette dernière espèce était alors seule exploitée dans le bassin. Il fallut attendre l'épizootie de 1920, qui anéantit presque totalement l'huître plate, pour que la portugaise soit définitivement admise. |
Tipo: Text |
Palavras-chave: Ostréiculture; Crassostrea gigas; Crassostrea angulata; Filtration; Bassin Arcachon; Gironde. |
Ano: 1970 |
URL: http://archimer.ifremer.fr/doc/00009/11978/8682.pdf |
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Ropert, Michel; Kopp, Joel. |
The Shellfish Laboratory of Normandy (LCN : Laboratoire Conchylicole de Normandie) observed unusual hydrologic anomalies associated with important oyster mortalities during the winter of 1999. These anomalies were described as sudden salinity variations during the lidal cycle, particularly on the rising tide. Starting in 1996 a multi-parameter probe was used to monitor salinity, temperature and depth every 10 to 20 minutes in the inter-tidal zone. Alter data processing and filtering, two criteria concerning low salinity were chosen : amplitude and duration. Application of a cumulative function (Ibanez et al., 1993) to this time series data treatment showed the 3 year trend (1996-1999). Salinity variation data and climatic data were used in a multivariate... |
Tipo: Text |
Palavras-chave: Crassostrea gigas; Mortalités; Salinité; Baie des Veys; Suivi; Crassostrea gigas; Mortality; Salinity; Baie of Veys; Monitoring. |
Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00102/21310/18928.pdf |
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Registros recuperados: 858 | |
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