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| Registros recuperados: 92 | |
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| Dao, Jean-claude; Gerard, Andre; Buestel, Dominique. |
| Research on the black scallop followed that on the king scallop. Indeed, over the 1973-1975 " spadework » period, it has been demonstrated that the roadsted of Brest was: - an overexploited king scallop deposit; the broodstock not being able to ensure a satisfying renewal of the species. - a black scallop production deposit (hundreds of tonnes). In parallel, the collection trials provided null results for the king scallop but very interesting results for the black scallop (thousands of spats per collector). From 1976 onwards, the spat collecting operations did not focus on king scallop juveniles anymore, but on black scallop. |
| Tipo: Text |
Palavras-chave: Reproduction; Captage; Physiologie; Pétoncle; Chlamys varia. |
| Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/1985/acte-6538.pdf |
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| Arzul, Isabelle; Renault, Tristan; Thebault, Anne; Gerard, Andre. |
| Since 1972, several herpes-like virus infections have been reported among different bivalve species around the world. Most of these reports involved larvae or juveniles presenting high mortalities. Two case reports of herpes-like viruses concerned adult oysters, Crassostrea virginica in USA and Ostrea angasi in Australia. Molecular techniques including PCR and in situ hybridization (ISH) have been recently developed to detect the oyster herpesvirus genome. In the present study, 30 Pacific oyster, Crassostrea gigas, adults have been analyzed using three different techniques: PCR, ISH and immunochemistry, in order to detect herpesviruses in asymptomatic individuals. PCR and ISH allowed detection of oyster herpesvirus DNA in 93.3 and 86.6%, respectively, of... |
| Tipo: Text |
Palavras-chave: Protein; DNA; Healthy carrier; Adult oyster; Crassostrea gigas; Herpesvirus. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-697.pdf |
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| Gerard, Andre. |
| Following the development of the hatchery tool, different triploidy induction techniques have been tried out in vitro. The method using cytochalasin B was selected and successfully applied to cupped oysters, Crassostrea gigas and especially to clams, Ruditapes philippinarum. Larval survival rates were lower than control rates. On the other hand, larvae's growth speed was comparable. These methods will now be used to produce significant test populations which will then be cultivated in French coastal waters. |
| Tipo: Text |
Palavras-chave: Palourdes; Huîtres creuses; Polyploïdisation; Conchyliculture. |
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/rapport-3853.PDF |
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| Boudry, Pierre; Collet, Bertrand; Kotoulas, Georgios; Magoulas, Antonio; Hervouet, Veronique; Bonhomme, Francois; Gerard, Andre. |
| Highly polymorphic genetic markers can be useful tools for the analysis of parental contributions. The present paper reports 3 experiments using microsatellite markers to analyse parental contributions in controlled in vitro factorial crosses of the cupped oyster Crassostrea gigas. Parentage analysis was eased by the large polymorphism observed at the 3 loci studied. In a cross between 20 males and 20 females, a quarter of the progeny could be assigned to a given parent using a single microsatellite locus showing 28 alleles. In 3 crosses between 5 males and females, all the progeny could be assigned to a family by using 3 loci. In all cases, the combined genotyping at 2 loci allowed parentage to be detennined unambiguously. Despite the balanced gametic... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Microsatellites; Parental contributions; Crassostrea gigas; Microsatellites; Contributions parentales. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/1998/acte-2739.pdf |
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| Naciri-graven, Y; Launey, Sophie; Lebayon, N; Gerard, Andre; Baud, Jean-pierre. |
| Genetic variability for growth was analysed in three populations of Ostrea edulis, selected for resistance to the protozoan parasite Bonamia ostreae. This study was undertaken first to determine the potential for selection for growth in populations that have never been selected for this character, and second to estimate heterosis versus inbreeding depression. Growth was monitored in culture for 10 months. The selected populations (namely S85-G3, S89I-G2 and S89W-G2), their crossbred population and a control population were composed of full-sib families whose parents were already genotyped using five microsatellite markers. This genotyping allowed the estimation of genetic relatedness among pairs of parents. The parents' relatedness was then correlated with... |
| Tipo: Text |
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| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-2719.pdf |
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| Cochard, Jean-claude; Gerard, Andre. |
| The analysis of the Pecten maximus larval productions carried out between 1982 and 1986 in the framework of the repopulating program of the roadsted of Brest demonstrated the existence of a number of factors affecting larval growth in hatcheries: - Larval growth shows important seasonal fluctuations. It is minimal in February-March (3 to 4 µm.D-1) and maximal in June (6 to 8 µm.D-1). The growth of larvae from conditioned spawners does not differ from that of larvae from mature genitors collected in their natural habitat. Growth is favoured by an unknown factor present in sea water and held with a filtration of 0,2 µm. - The growth of the larvae cultivated in slack water in flat bottom ponds is higher than that of the larvae cultivated in bubbling water in... |
| Tipo: Text |
Palavras-chave: Larve; Ecloserie; Croissance organisme; Coquille Saint Jacques; Pecten maximus L.; Production. |
| Ano: 1987 |
URL: http://archimer.ifremer.fr/doc/1987/acte-6534.pdf |
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| Gerard, Andre; Thouard, Emmanuel; Veron, Gerard; Denis, Jacques; Thebaud, Olivier. |
| The "Artificial reefs" and "Repopulating" issues have been tackled by the Ifremer for a number of years without reaching a clear cut point of view, mainly for lack of socio-economic elements necessary to a rigorous analysis of these devices and practices. During a mission in Japan in January 2006, some Japanese experts, have presented to the head of the Ifremer a few examples of realisations related to these fields and conducted in their country. The head of the Ifremer realised the scope of such devices in Japan and expressed the wish to see an in-depth study carried out over there. In this purpose, the International Relationship Department organised and co-financed the three-month stay in Japan of a student from the University of Montpellier III, Sylvain... |
| Tipo: Text |
Palavras-chave: France; Etranger; Recommandations; Réglementation; Cadre juridique; Protection; Aménagement; Intérêt; Ecosystème; Récifs artificiels. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/rapport-6533.pdf |
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| Gerard, Andre; Thouard, Emmanuel; Zambonino, Jose-luis; Gaignon, Jean-louis; Antoine, Loic; Harache, Yves; Veron, Gerard; Perez, Jose. |
| The repopulating of aquatic environments has long been based on the idea that in order to increase halieutic resources, one just had to artificially increase the number of fish in their early stages in marine or fresh water environments. Therefore, as the knowledge on the reproduction of some species and the mastery of their artificial reproduction was growing, the capacity to produce large amounts of eggs or fries from different fish or mollusc species became a reality. Controlled reproduction and the availability of large quantities of fertilized eggs, and then of larvae showing, in captivity, a greater survival capacity than naturally reproduced ones, lead to an increase of repopulating attempts through the release of fries or young fishes raised in... |
| Tipo: Text |
Palavras-chave: Recommandation; Repeuplement; Milieu aquatique; Ressources halieutiques. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/rapport-6532.pdf |
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| Boudry, Pierre; Collet, B; Mccombie, Helen; Ernande, Bruno; Morand, B; Heurtebise, Serge; Gerard, Andre. |
| In order to study individual growth variability and its relationship with survival in juvenile Crassostrea gigas, parental oysters were sampled at four sites located along the French Atlantic coast and bred under controlled hatchery conditions. Four groups of larvae were obtained by crossing five males and five females from each of the four sites, and a fifth group by crossing these 20 males and 20 females together in a pool. Larvae were reared under conditions allowing the maintenance of a maximum variability of size and gave five experimental groups. Oysters were individually monitored for growth and survival from 3 to 10 months after fertilization. The individual growth performances were relatively stable over time and no noticeable compensation for... |
| Tipo: Text |
Palavras-chave: Survival; Oysters; Growth; Crassostrea gigas; Aquaculture. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-467.pdf |
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| Goulletquer, Philippe; Joly, Jean-pierre; Gerard, Andre; Le Gagneur, Eric; Moriceau, Jacques; Peignon, Jean-marie; Heurtebise, Serge; Phelipot, Pascal. |
| Triploid oysters Crassllstrea gigas were: produced in 1990 by treating fertilized eggs with cytochalasin B (CS). Triploids, treated diploids, and controls were deployed early 1991 in a high carrying capacity ecosystem on the Eastern Coast of Normandy (France). A monthly monitoring in 1992 showed that triploids yielded significantly higher growth rate and biochemical composition. However, growth was more heterogeneous. No evidence was found for a length or weight bimodal frequency distribution within triploid groups after a 26 months rearing cycle. Triploids showed retardation of gametogenesis. Carbohydrates content in triploids remained almost constant (40%) from June to September. Their survival rates were significantly lower than controls. Moreover... |
| Tipo: Text |
Palavras-chave: Biochemical compostion; Survival; Carrying capacity; Triploid; Growth; Oysters; Crassostrea gigas; Composition biochimique; Survie; Capacité trophque; Triploïdes; Croissance; Huîtres; Crassostrea gigas. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/1996/publication-3088.pdf |
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| Gerard, Andre; Naciri, Yamama; Peignon, Jean-marie; Ledu, Christophe. |
| A novel method using 6-dimcthylaminopurinc (6-0MAP) has recently been demonstrated to be a good triploid inductor for bivalve molluscs. The effects of 6-DMAP concentration, timing of treatment after fertilization and treatment duration on survival and triploid induction of Crassostrea gigas (Thunberg) embryos were examined. An influence of sperm concentration was also detected and discussed. Survival to D-stage was inversely related to 6-DMAP concentration and the percentage of triploids was shown to be 6-DMAP dose dependent. Two optimal moments for treatment application were determined corresponding to extrusions of the first and second polar bodies. Optimal treatment of 450 µmol/l 6-DMAP beginning 15 min after fertilization over a 10 min period yielded... |
| Tipo: Text |
Palavras-chave: Genetic; Triploid induction; Crassostrea gigas; 6 DMAP; Triploid; Oysters. |
| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/1994/publication-3198.pdf |
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| Amiard, Jean-claude; Perrein Ettajani, H; Gerard, Andre; Baud, Jean-pierre; Amiard Triquet, C. |
| The present study was designed to compare the response to contaminants in diploid with triploid specimens of the oyster Crassostrea gigas. The reproduction investment in bivalve molluscs has priority on somatic growth. Thus, genetic sterilization by triploidy induction enables the energy flux to be directed toward somatic growth and glucide storage. Bioaccumulation was examined for Ag (10 mug/L), Cd (10 mug/L), and Cu (30 mug/L) to determine if the response to metals follows similar patterns in diploid (2n) and triploid (3n) groups. The effect of ploidy was also evaluated as a function of dry weight of soft tissue and condition index. Moreover, the reciprocal influence of these metals on their incorporation was studied. The results showed that the major... |
| Tipo: Text |
Palavras-chave: Oyster culture; Metal bioaccaumulation; Polyploidy. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-791.pdf |
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| Huvet, Arnaud; Gerard, Andre; Ledu, Christophe; Phelipot, Pascal; Heurtebise, Serge; Boudry, Pierre. |
| The distinction of the two cupped oysters Crassostrea gigas (Thunberg, 1793) and Crassostrea angulata (Lamark, 1819) into two species was chiefly due to their differing geographical distributions, C. gigas being present in Asia and C. angulata in Europe. Today it is commonly accepted that C. angulata and C. gigas are a single species according to morphological, genetic and F1 hybridization data. However, the demonstration of the fertility of their hybrids and the absence of any reproductive isolation remained to be investigated. Consequently, we studied the fertility of hybrids and sperm competition by performing three different experiments and producing G1 and G2 hybrid progenies between wild populations of C. angulata and C. gigas. Progenies showed very... |
| Tipo: Text |
Palavras-chave: Crassostrea angulata; Crassostrea gigas; Developmental yields of larvae; Fertility; Controlled crosses; Hybridization. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-1395.pdf |
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| Gerard, Andre. |
| Cette revue bibliographique, consacrée à la 'Ifilière" coquille Saint-Jacques, devait en théorie, faire abstraction de toutes les études traitant de cette espèce comme d'un "modèle" biologique. Lu frontière entre "fi1ière1'et "modèle" n'est pas aussi simple que l'on pourrait le penser. Lu filière coquille Saint-Jacques, après les échecs des opérations de captage, repose depuis 1982 sur la production de naissain en écloserie. Le développement d'une telle filière de production ne pouvait se faire sans un minimum de recherche dans des domaines comme la "nutrition larvairen ou la "Iphysiologie de la reproduction1'. Ces domaines de recherche qui se sont développés à I'IFREMER, l'ont été , au moins au départ, pour répondre aux besoins des acteurs de la filière... |
| Tipo: Text |
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| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00080/19080/16675.pdf |
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| Gerard, Andre. |
| Des élevages d'Artemia salina en milieux non renouvelés sont réalisés au Centre Océanologique de Bretagne pour l'étude de la nutrition et le contrôle des taux physiologiques, Sur ces élevages, un certain nombre de paramètres sont mesurés en continu ou semi-continu : pH, température, oxygène dissous, nitrites, ammoniaque, biomasse chlorophylienne... Les premières expériences avaient mis en évidence des variations dans le temps des paramètres mesurés avec des seuils d'équilibre résultant vraisemblablement d'une auto-régulation par les bactéries. Dans tous les écosystèmes aquatiques ou terrestres le rôle de la microflore bactérienne est primordial ; le métabolisme bactérien est un maillon essentiel des cycles vitaux du carbone, de l'azote et du soufre... Nous... |
| Tipo: Text |
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| Ano: 1976 |
URL: http://archimer.ifremer.fr/doc/00444/55535/57124.pdf |
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| Registros recuperados: 92 | |
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