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Registros recuperados: 11 | |
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Linard, Clementine; Gueguen, Yannick; Moriceau, Jacques; Soyez, Claude; Hui, Belinda; Raoux, Aurore; Cuif, Jean Pierre; Cochard, Jean-claude; Le Pennec, Marcel; Le Moullac, Gilles. |
Marine mollusc shell growth has been widely measured using fluorochrome marking. In order to test the efficiency and reliability of calcein staining on P. margaritifera shells and pearls, the present study examined two administration methods, different concentrations and several immersion times.Immersion in a 150 mg.L-1 calcein solution for 12 h to 24 h appeared to be the best method for marking P. margaritifera shells. For pearl marking, injection of a 200 mg.L-1 calcein solution into the pearl pouch was the optimal method. Calcein marking was then used to measure the influence of food resource levels on the shell growth. Groups of 23-month-old P. margaritifera were fed at three trophic levels for two months. The two highest food levels tested (6 000... |
Tipo: Text |
Palavras-chave: Bivalvia; Pearl; Shell; Growth; Scanning electron microscope. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00028/13907/11195.pdf |
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Normand, Julien; Le Pennec, Marcel; Boudry, Pierre. |
We compared the temporal dynamics of gametogenesis in diploid and triploid Pacific oysters (Crassostrea gigas) using histology. Oysters were reared in an estuarine farming site in Brittany over 3 years and their gametogenesis was monitored over the exceptionally hot summer of 2003. Both diploids and triploids showed active gametogenesis, but a high proportion of triploids remained at early stages of gonad development. Gametogenesis of triploids was characterized by the simultaneous occurrence of gonias and immature cytes together with mature gametes rather than overall retardation, though some triploids showed complete gonad maturation. Evidence of spawning was seen in both groups, and the quantity of germinal products emitted appeared to be similar in... |
Tipo: Text |
Palavras-chave: Triploidy; Crassostrea gigas; Oyster; Gametogenesis. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4152.pdf |
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Hui, Belinda; Demoy-schneider, Marina; Vonau, Vincent; Le Moullac, Gilles; Moriceau, Jacques; Le Pennec, Marcel; Cochard, Jean-claude. |
Cryopreservation is a useful tool for genetic improvement which has been applied to several bivalve mollusk species. It would allow to keep the gametes of selected individuals and to preserve ex-situ the biodiversity of wild populations of the black-lip pearl oyster Pinctada margaritifera threatened of standardization by the seed transfers between the islands in French Polynesia. The ability to cryopreserve spermatozoa would bring about significant benefits to the cultured black pearl industry. Sperm freezing supposes the control of different steps: preparation of breeders, sperm collection, evaluation of sperm quality and the freezing process itself. Broodstock conditioning in hatchery allows to obtain gametes from the pearl oyster. Sperm quality is... |
Tipo: Text |
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Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00029/14043/11238.pdf |
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Fournier, Jonathan; Levesque, Emmanuelle; Pouvreau, Stephane; Le Pennec, Marcel; Le Moullac, Gilles. |
Pearl culture industry represents one of the dominant business sector of French Polynesia. However, it still entirely relies on unpredictable spat collection success. Our aim was to assess the influence of natural plankton concentration fluctuations on maturation and spawning of the black lip pearl oyster Pinctada margaritifera, during a 4 months survey conducted in Ahe atoll lagoon. Plankton concentration was assessed by chlorophyll a extraction and by microscope counts while gonadic index, gonado-visceral dry weights and histology were used to measure pearl oysters reproduction activity. We found that (i) plankton concentration fluctuations were mainly related to wind regime, (ii) gametogenesis rate was mainly related to plankton concentration, (iii)... |
Tipo: Text |
Palavras-chave: Pearl Oyster; Gametogenesis; Spawning; Phytoplankton; French Polynesia. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00101/21201/19697.pdf |
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Thomas, Yoann; Garen, Pierre; Bennett, Auguste; Le Pennec, Marcel; Clavier, Jacques. |
Bivalve larvae and hydrographic parameters were sampled over a range of spatio-temporal scales in a deep atoll lagoon. Bivalve larvae abundances were very high throughout the year: 18,550 m(-3) in average. Larvae were (i) concentrated at mid-depth with nocturnal ascent and diurnal descent, (ii) heterogeneously dispersed at the lagoon scale, (iii) subject to day-to-day variation in abundance and (iv) transferred between different parts of the lagoon providing evidence of intra-lagoonal connectivity. The primacy of physical factors was seen on large spatial scale with the diluting effect of water renewal and transfers by hydrodynamics. On smaller spatial scale, the primacy of biological processes was recognised, with larval swimming activity leading to dial... |
Tipo: Text |
Palavras-chave: Bivalve larvae; Distribution patterns; Vertical migration; Pinctada margaritifera settlement; Deep atoll lagoon; French Polynesia. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00101/21200/20690.pdf |
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Gerard, Andre; Naciri, Yamama; Peignon, Jean-marie; Ledu, Christophe; Phelipot, Pascal; Baud, Jean-pierre; Nourry, Max; Haure, Joel; Heurtebise, Serge; Garnier, Jacqueline; Martin, Anne-genevieve; Claude, Serge; Langlade, Aime; Joly, Jean-pierre; Goulletquer, Philippe; Ruelle, Francois; Coatanea, Denis; Oheix, Jocelyne; Vercelli, Catherine; Chabirand, Jean-michel; Maurer, Daniele; Borel, Michel; Cardinal, Mireille; Cornet, Josiane; Le Pennec, Marcel; Le Mercier, A.. |
This fifth part of the polyploidisation program reports the experiments that were conducted in 1993 and that were devoted to : - monitoring growth performance of Ostrea edulis diploids and triploids in La Trinité sur Mer and Palavas - monitoring growth performance of Crassostrea gigas diploids and triploids in Port en Bessin, Marennes Oleron (2 locations), Arcachon and Palavas - comparative study of gametogenesis for C. gigas diploids and triploids - comparative study of C. gigas diploids and triploids using sensorial analysis At the end of fifth year, it was clear that triploids are advantageous although such a statement must be moderated according to locations. The gametogenesis stydy showed that triploidy is associated with partial to complete... |
Tipo: Text |
Palavras-chave: Crassostrea gigas; Ostrea edulis; Cytogenetics; Polyploidy; Crassostra gigas; Ostrea edulis; Cytogénétique; Polyploïdie. |
Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/1994/rapport-3860.PDF |
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Le Pennec, Marcel; Coatanea, Denis. |
La production en écloserie de l'huître de roche Saccostrea cucullata echinata été réalisé en Polynésie française au Centre Océanologique du Pacifique (Taravao, Tahiti), à partir de géniteurs importés de Nouvelle-Calédonie. La morphogenèse de la charnière a été étudiée au microscope électronique à balayage depuis la naissance des denticules chez la prodissoconque II jusqu'à leur régression chez la jeune dissoconque. Ces observations montrent l'originalité de la charnière de cette espèce et permettent de confirmer la détermination du nouveau genre Saccostrea au sein de la famille des Ostreidae. Elles montrent aussi que la charnière primitive de Saccostrea se rapproche de celle d'Ostrea, ce qui permet de les situer à une place voisine dans le schéma de la... |
Tipo: Text |
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Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/00150/26165/24260.pdf |
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Fabioux, Caroline; Huvet, Arnaud; Le Souchu, Pierrick; Le Pennec, Marcel; Pouvreau, Stephane. |
This study examined the gametogenic cycle of Crassostrea gigas in controlled conditions over one year, with a focus on the initiation of gametogenesis. This work analysed also the role of temperature and photoperiod in the regulation of oyster reproduction. Broodstock were maintained in natural (NC), accelerated (AC) and perpetual winter (WC) conditions of temperature and photoperiod, with feeding ad libitum. Qualitative and quantitative analyses of the reproductive pattern were performed using biometric measurement approach, sex ratio determination, histology and a gonad filling index. Each experimental treatment led to different strategies for growth and resource allocation. The gametogenic cycle, appeared entirely modulated, accelerated or delayed, by... |
Tipo: Text |
Palavras-chave: Temperature; Regulation; Gonad filling index; Gonial mitosis; Reproduction; Oyster. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-826.pdf |
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Registros recuperados: 11 | |
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