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Registros recuperados: 65
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Toxic effects of leachates from plastic pearl-farming gear on embryo-larval development in the pearl oyster Pinctada margaritifera ArchiMer
Gardon, Tony; Huvet, Arnaud; Paul-pont, Ika; Cassone, Anne-laure; Koua, Manaarii Sham; Soyez, Claude; Jezequel, Ronan; Receveur, Justine; Le Moullac, Gilles.
Pearl-farming leads to significant plastic pollution in French Polynesia (FP) as the end of life of most farming gear is currently poorly managed. Plastic debris released into the aquatic environment accumulates, with potentially detrimental effects on the lagoon ecosystem and pearl oyster Pinctada margaritifera, a species of ecological, commercial and social value. Here, we tested the effects of leachates from new (N) and aged (A) plastic pearl-farming gear (spat collector and synthetic rope) obtained after 24 h and 120 h incubation, on the embryo-larval development of the pearl oyster using an in-vitro assay. Embryos were exposed for 24 h and 48 h to a negative control (0) and the leachate from 0.1, 1, 10 and 100 g of plastic. L−1. After 24 h exposure to...
Tipo: Text Palavras-chave: Aquaculture; Synthetic materials; Hazardous chemicals; Toxicity; Marine bivalve; Early development.
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00627/73917/73257.pdf
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Transcriptional regulation of pyruvate kinase and phosphoenolpyruvate carboxykinase in the adductor muscle of the oyster Crassostrea gigas during prolonged hypoxia ArchiMer
Le Moullac, Gilles; Bacca, Helene; Huvet, Arnaud; Moal, Jeanne; Pouvreau, Stephane; Van Wormhoudt, A.
The response of Crassostrea gigas to prolonged hypoxia was investigated for the first time by analyzing the metabolic branch point formed by pyruvate kinase (PK) and phosphoenolpyruvate carboxykinase (PEPCK). PK and PEPCK cDNAs were cloned and sequenced. The main functional domains of the PK sequence, such as the binding sites for ADP/ATP and phosphoenolpyruvate (PEP), were identified whereas the PEPCK sequence showed the specific domain to bind PEP in addition to the kinase-1 and kinase-2 motifs to bind guanosine triphosphate (GTP) and Mg2+, specific for all PEPCKs. A C-terminal extension was detected for the first time in eukaryota PK. Separation of mitochondrial and cytosolic fraction showed that more than 92% of the PEPCK enzyme activity was cytosolic...
Tipo: Text Palavras-chave: Succinate alanine carboxykinase phosphoenolpyruvate pyruvate kinase hypoxia Oyster.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-2683.pdf
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Determination of gender in the pearl oyster pinctada margaritifera ArchiMer
Chavez-villalba, Jorge; Soyez, Claude; Huvet, Arnaud; Gueguen, Yannick; Lo, Cedrik; Le Moullac, Gilles.
The pearl industry in French Polynesia is based on exploitation of natural stocks of the black-lip pearl oyster (Pinctada margaritifera); it generates an annual turnover of 90 million euros. Improvements in pearl quality need genetic studies to improve the populations. This pearl oyster is a protandric species, where the sex-ratio normally is biased towards males. There is an increasing interest in gender control to find the mechanisms to augment female proportions for management purposes. This review summarizes information on exogenous and endogenous factors regulating gender in this and other bivalves and concludes that P. margaritifera is a protandric hermaphrodite, developing as a male during the first two years and without evidence of an effect from...
Tipo: Text Palavras-chave: Pearl oyster; Pinctada; Hermaphrodite; Temperature; Food; Stress; Sex genes; Sex steroids.
Ano: 2011 URL: http://archimer.ifremer.fr/doc/00040/15100/12543.pdf
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Production de post-larves de P. japonicus, gain de productivité par modification des séquences alimentaires ArchiMer
Le Moullac, Gilles.
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Ano: 1986 URL: http://archimer.ifremer.fr/doc/00357/46826/46696.pdf
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Gamete cryopreservation, an asset for a durable pearl farming in French Polynesia ArchiMer
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...
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Ano: 2009 URL: http://archimer.ifremer.fr/doc/00029/14043/11238.pdf
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Adaptation du métabolisme respiratoire de l'huître creuse Crassostrea gigas ArchiMer
Le Moullac, Gilles.
Summer mortality of the oyster result from the interaction of many factors. A respiratory assumption proposes a link between the supposed causes of the energy state, the cultivation methods and the medium. This work is focused towards the search for specific metabolic markers of environmental stresses. The cDNA of genes coding for PK and PEPCK were cloned and sequenced in order to detect their regulation level. The sediment nearness affects the state of energy reserves, the metabolic pathways of energy production implying a regulation of the PK. Face to the dissolved oxygen decline, oysters were oxyregulator but with a low regulation ability. In hypoxia, glycolysis was slowed down. PK activity was inhibited resulting from an increase in alanine sensitivity...
Tipo: Text Palavras-chave: Régulation; Enzyme; Expression génique; Anoxie; Bivalve.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/these-4315.pdf
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Défi MOREST - Mortalités estivales de l'huître creuse Crassostrea gigas. Caractérisation des facteurs de risques associés aux mortalités estivales - Synthèse du thème 6 - Le risque température. (La Rochelle 14- 15 mars 2006) ArchiMer
Lambert, C.; Moal, J.; Pouvreau, Stephane; Le Moullac, Gilles; Samain, Jean-francois.
Les mortalités apparaissent toujours très rapidement après le passage de la température de l'eau à 19°C. II a bien été montré que ce n'était pas la valeur absolue de la température qui était associée à la mortalité, puisque des années très chaudes comme 2003, peu de mortalités étaient enregistrées. II s'agit plutôt d'un seuil à partir duquel le risque devient réel. La température affecte tous les processus de la physiologie et c'est un facteur clef de la distribution géographique des espèces. Les espèces se maintiennent dans les conditions environnementales qui ont permis leur adaptation. Les mortalités traduisent donc une rupture de l'adaptation ou une modification brutale de l'environnement qui peut affecter les équilibres qui se sont installés entre...
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Ano: 2006 URL: http://archimer.ifremer.fr/doc/00304/41537/40745.pdf
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Rapid and sensitive PCR detection of Vibrio penaeicida, the putative etiological agent of syndrome 93 in New Caledonia ArchiMer
Saulnier, Denis; Avarre, Jean-christophe; Le Moullac, Gilles; Ansquer, Dominique; Levy, Peva; Vonau, Vincent.
Experimental infections of Penaeus (Litopenaeus) stylirostris were performed with a Vibrio penaeicida strain (AM101) isolated in New Caledonia from Syndrome 93 diseased shrimp. Cumulative mortalities resulting from intramuscular injection or immersion of shrimp in bacterial suspensions demonstrated high virulence for this bacterial strain and suggested that V. penaeicida could be the etiological agent of Syndrome 93. The median lethal dose (LD50) for AM101 was 1.3 x 104 CFU (colony forming units) ml-1 by immersion and less than 5 CFU shrimp-1 by intramuscular challenge, with mortality outbreaks at 48 and 22 h after challenge, respectively. A polymerase chain reaction (PCR) detection assay using a primer set designed from the 16S ribosomal RNA gene of V....
Tipo: Text Palavras-chave: Small subunit rDNA gene; Penaeus (Litopenaeus) stylirostris; Vibriosis; Shrimp disease; PCR diagnosis; Vibrio penaeicida; Syndrome 93.
Ano: 2000 URL: http://archimer.ifremer.fr/doc/2000/publication-4436.pdf
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Pearl Oysters Pinctada margaritifera grazing on natural plankton in Ahe atoll lagoon (Tuamotu archipelago, French Polynesia) ArchiMer
Fournier, Jonathan; Dupuy, Celie; Bouvy, Marc; Couraudon-reale, Marine; Charpy, Loic; Pouvreau, Stephane; Le Moullac, Gilles; Le Pennec, Marie-annick; Cochard, Jean-claude.
In atoll lagoons of French Polynesia, growth and reproduction of pearl oysters are mainly driven by plankton concentration. However, the actual diet of black-lip pearl oysters P. margaritifera in these lagoons is poorly known. To fill this gap, we used the flow through chamber method to measure clearance rates of P. margaritifera in Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia). We found : (i) that pearl oysters cleared plankton at a rate that was positively related to plankton biovolume, (ii) that nanoflagellates were the main source of carbon for the pearl oysters, (iii) that the quantity and origin of carbon filtrated by pearl oysters was highly dependent on the concentration and composition of plankton. These results provide essential...
Tipo: Text Palavras-chave: Pinctada margaritifera; Clearance rates; French Polynesia; Phytoplankton; Protists.
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00078/18888/16599.pdf
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Evidence of a Biological Control over Origin, Growth and End of the Calcite Prisms in the Shells of Pinctada margaritifera (Pelecypod, Pterioidea) ArchiMer
Cuif, Jean-pierre; Burghammer, Manfred; Chamard, Virginie; Dauphin, Yannicke; Godard, Pierre; Le Moullac, Gilles; Nehrke, Gernot; Perez-huerta, Alberto.
Consistently classified among the references for calcite simple prisms, the microstructural units that form the outer layer of the Pinctada margaritifera have been investigated through a series of morphological, crystallographical and biochemical characterizations. It is often said that the polygonal transverse shape of the prisms result from the competition for space between adjacent crystals. In contrast to this classical scheme the Pinctada prisms appear to be composed of four successive developmental stages from the concentrically growing disks on the internal side of the periostracum to the morphological, structural and compositional changes in both envelopes and mineral components at the end of the prisms. These latest structural and compositional...
Tipo: Text Palavras-chave: Biomineralization; Bivalve shell; Microstructure; Calcite prisms.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00249/36039/34574.pdf
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Estimation of physical and physiological performances of blacklip pearl oyster larvae in view of DEB modeling and recruitment assessment ArchiMer
Sangare, Nathanael; Lo-yat, Alain; Le Moullac, Gilles; Pecquerie, Laure; Thomas, Yoann; Beliaeff, Benoit; Andrefouet, Serge.
In French Polynesia black pearl farming represents one of the dominant business sectors. However, it still entirely relies on unpredictable Pinctada margaritifera spat collection success, which is itself conditioned by larval development completion. To assess the relationship between larval development and recruitment success, we studied under controlled conditions the effect of food concentration on development, growth, ingestion rate, survival and metabolic rate at the larval stage. Larvae were exposed to four different phytoplankton densities (2,5; 7,5; 15 and 30 cell.μL−1). Larvae survived equally all over the range of phytoplankton concentration with an average survival rate of 16% at the end of experiments. Food concentration significantly affected...
Tipo: Text Palavras-chave: Bivalve larvae; Pinctada margaritifera; Physiology; Energetics; Dynamic energy budget theory; Pearl farming; Aquaculture.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00476/58795/61446.pdf
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Quantification of eggs and sperm in the Black-lip pearl oyster Pinctada margaritifera using an enzyme-linked immunosorbent assay (ELISA) ArchiMer
Jeung, Hee-do; Kang, Do-hyung; Park, Heung-sik; Le Moullac, Gilles; Choi, Kwang-sik.
We have developed immunological probes to quantify eggs and sperm of the Black-lip pearl (BLP) oyster Pinctada margaritifera. The western blot assay revealed that the polyclonal antibodies developed in this study specifically recognized only egg and sperm proteins. These polyclonal antibodies also showed high sensitivities to the antigens, detecting 0.31–10 μg/ml of the egg or sperm proteins in an indirect enzyme-linked immunosorbent assay (ELISA). Accordingly, we used an indirect ELISA to quantify the eggs and sperm in BLP oysters collected in December 2009 from Weno Island in Micronesia and in May 2010 from Tahiti. The gonad somatic index (GSI), a ratio of gonad weight to somatic tissue weight, of the females collected from Weno Island ranged from 3.6 to...
Tipo: Text Palavras-chave: Black-lip pearl oyster; ELISA; Pinctada margaritifera; Polyclonal antibody; Quantification of eggs and sperm.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00175/28659/32145.pdf
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Influence of water temperature and food on the last stages of cultured pearl mineralization from the black-lip pearl oyster Pinctada margaritifera ArchiMer
Latchere, Oihana; Mehn, Vincent; Gaertner-mazouni, Nabila; Le Moullac, Gilles; Fievet, Julie; Belliard, Corinne; Cabral, Philippe; Saulnier, Denis.
Environmental parameters, such as food level and water temperature, have been shown to be major factors influencing pearl oyster shell growth and molecular mechanisms involved in this biomineralization process. The present study investigates the effect of food level (i.e., microalgal concentration) and water temperature, in laboratory controlled conditions, on the last stages of pearl mineralization in order to assess their impact on pearl quality. To this end, grafted pearl oysters were fed at different levels of food and subjected to different water temperatures one month prior to harvest to evaluate the effect of these factors on 1) pearl and shell deposition rate, 2) expression of genes involved in biomineralization in pearl sacs, 3) nacre...
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Ano: 2018 URL: https://archimer.ifremer.fr/doc/00428/54007/55223.pdf
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Biofouling development and its effect on growth and reproduction of the farmed pearl oyster Pinctada margaritifera ArchiMer
Lacoste, Elise; Le Moullac, Gilles; Levy, Peva; Gueguen, Yannick; Gaertner-mazouni, Nabila.
In bivalve aquaculture, dominant fouling organisms are filter feeders which can compete for food with reared bivalves, sometimes causing mortality or reducing their growth rate. This study investigated the effect of biofouling on the farmed pearl oyster Pinctada margaritifera in two lagoons of French Polynesia. Survival, growth and reproduction of 2 year-old pearl oysters were monitored with regular sampling schedules, from the initial stage of colonization up to 20 months of biofouling accumulation. Control groups of pearl oysters were kept free of biofouling as is the current practice in pearl farms. After more than a year of monitoring, no significant difference was recorded in shell growth rate between pearl oysters reared with epibionts and the...
Tipo: Text Palavras-chave: Pearl oyster culture; Pinctada margaritifera; Biofouling; Growth; Reproduction.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00201/31188/29587.pdf
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Changes in fatty acid and sterol composition during oogenesis in the pearl oyster Pinctada margaritifera ArchiMer
Vahirua Lechat, I; Laure, F; Le Coz, Jean-rene; Bianchini, J; Bellais, M; Le Moullac, Gilles.
The fatty acid and sterol composition of the oyster Pinctada margaritifera during oogenesis and in eggs was analysed. No major differences were observed during oogenesis, but the egg composition was significantly different from that of gonads. The amount of saturated fatty acids was the highest in eggs and the C16:0 predominant (P < 5%); by contrast, the amount of 22:6(n-3) was significantly lower (P < 5%) than in gonads. No major differences were observed for the polar lipid (PL) composition during oogenesis. The main free sterols in gonads and eggs were cholesterol and brassicasterol. Among free sterols, the proportion of cholesterol diminished continuously from the beginning to the end of gonad maturation, and this decrease persisted in eggs after...
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Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-5902.pdf
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Physiological responses of female and male black-lip pearl oysters (Pinctada margaritifera) to different temperatures and concentrations of food ArchiMer
Chavez-villalba, Jorge; Soyez, Claude; Aurentz, Hermann; Le Moullac, Gilles.
This study was designed to measure responses of four-year-old black-lip pearl oysters (Pinctada margaritifera) to different temperatures and food concentrations and to identify the energy requirements of each sex. Oysters were fed a monospecific microalgal diet of Isochrysis affinis galbana (T-iso). Measurements of oxygen consumption and ingestion rates were carried out at 24 degrees C and 27 degrees C and at two algal (T-iso) concentrations: 5000 and 30 000 cell ml(-1). Glycogen content in adductor muscle, absorption efficiency and scope for growth were also estimated. Females and males responded differently to environmental factors, with food level being the most influential parameter. Oxygen consumption and absorption efficiency were significantly...
Tipo: Text Palavras-chave: Food supply; Ingestion rate; Glycogen; Oxygen consumption; Scope for growth; Pearl oyster.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00157/26855/24980.pdf
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Calcein staining of calcified structures in pearl oyster Pinctada margaritifera and the effect of food resource level on shell growth ArchiMer
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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Expérimentation in situ des effets d'un immunostimulant administré par voie orale chez Penaeus stylirostris. Rapport de mission en Nouvelle- Calédonie du 29/11/96 au 13/12/96 ArchiMer
Le Moullac, Gilles; Boglio, Eric; Goarant, Cyrille.
Une substance immunostimulante administrée par voie orale est testée chez la crevette Penaeus stylirostris. Cette expérimentation est réalisée à la station de St Vincent afin de se rapprocher des conditions du Syndrôme 93. Les effets sont mesurés pendant 2 semaines sur des paramètres hématologiques (hémocytes totaux, cellules à grands granules, coloration spécifique : cellules incorporant le rouge neutre). D'autre part un stress des crevettes en cage sur un fond réduit en bassin constitue le challenge. L'administration de l'immunostimulant par voie orale augmente significativement le nombre des hémocytes totaux, ainsi que les cellules incorporant le rouge neutre. Cependant le stress de la mise en cage sur fond réduit n'a pas déclenché de mortalité de type...
Tipo: Text Palavras-chave: Penaeus stylirostris; Syndrome 93; Immunostimulant; Hémocyte; Stade de mue..
Ano: 1997 URL: https://archimer.ifremer.fr/doc/00680/79245/81762.pdf
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Caracterization de las trypsinas y amilasas de Penaeus vannamei (crustacea decapoda) : adaptacion a la composicion deln regimen alimenticio ArchiMer
Van Wormhoudt, Alain; Le Moullac, Gilles; Klein, Birgit; Sellos, Daniel.
Las tripsinas, entre las proteasas, y las amilasas, entre las carbohidrasas, son las enzimas más activas en Penaeus vannamei, un camarón de interés comercial, especialmente en Latinoamérica. Estas enzimas y sus cDNAS fueron caracterizados. En lo que respecta a las tripsinas, se reconocieron cinco isoformas y se analizaron sus cDNAs correspondientes, los cuales codifican una preproenzima de 225 aminoácidos conteniendo un supuesto precursor peptídico de 14 residuos y una secuencia señal altamente hidrofobica de 14 aminoácidos. Dentro de la secuencia del zimogeno, se detectaron algunos sitios autocatalíticos (Int. J. Biochem. Cell Biol. 1996, 28, 551-563). Con respecto a las amilasas, dos isoformas fueron purificadas y caracterizadas; se hizo una selección en...
Tipo: Text
Ano: 1999 URL: http://archimer.ifremer.fr/doc/00176/28726/27183.pdf
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Shell Growth Performance of Hatchery Produced Pinctada margaritifera: Family Effect and Relation with Cultured Pearl Weight ArchiMer
Ky, Chin-long; Le Moullac, Gilles.
Size is the most important and valuable quality trait of cultured pearls produced by the black-lipped pearl oyster, Pinctada margaritifera. In French Polynesia, several breeding programmes have been started that aim to improve this size trait, which is highly related to shell growth rate in both recipient and donor oysters. Shell growth rate dictates the time of grafting, size of implanted nuclei and bio-mineralisation potential of the mantle and pearl sac. We assessed shell growth rate through routine digital shell biometric analysis on 22 hatchery families produced between 2005 and 2008. These included full-sib families and half-sib families derived from polyandry (one dam crossed with two or more sires). Results showed that: 1) a significant family...
Tipo: Text Palavras-chave: Pinctada margaritifera; Pearl oyster; Hatchery-produced families; Growth performance; Shell diameter; Cultured pearl size.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00387/49810/50384.pdf
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