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| Registros recuperados: 65 | |
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| Teaniniuraitemoana, Vaihiti; Lepretre, Maxime; Levy, Peva; Vanaa, Vincent; Parrad, Sophie; Gaertner-mazouni, Nabila; Gueguen, Yannick; Huvet, Arnaud; Le Moullac, Gilles. |
| The black-lip pearl oyster Pinctada margaritifera is a protandrous hermaphrodite species. Its economic value has led to the development of controlled hatchery reproduction techniques, although many aspects remain to be optimized. In order to understand reproductive mechanisms and their controlling factors, two independent experiments were designed to test hypotheses of gametogenesis and sex ratio control by environmental and hormonal factors. In one, pearl oysters were exposed under controlled conditions at different combinations of temperature (24 and 28°C) and food level (10,000 and 40,000 cells mL−1); whereas in the other, pearl oysters were conditioned under natural conditions into the lagoon and subjected to successive 17β-estradiol injections (100 μg... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00285/39638/38184.pdf |
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| 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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| 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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| Sangare, Nathanael; Lo-yat, Alain; Le Moullac, Gilles; Pecquerie, Laure; Thomas, Yoann; Lefebvre, Sebastien; Le Gendre, Romain; Beliaeff, Benoit; Andréfouët, Serge. |
| The black-lipped pearl oyster (Pinctada margaritifera) is extensively farmed in French Polynesia to produce black pearls. For a sustainable management of marine resources, studying interactions between organisms and environment, and the associated factors and processes that will impact their life cycle and thus modulate population dynamics is a major research priority. Here, we describe black-lipped pearl oyster energy acquisition and use, and its control by temperature and food concentration within the Dynamic Energy Budget (DEB) theory framework. The model parametrization was based on literature data and a specific laboratory experiment. Model validation was carried out thanks to historical in-situ datasets and a dedicated field survey. Three theoretical... |
| Tipo: Text |
Palavras-chave: Bivalve; Physiology; Bioenergetics; Dynamic energy budget theory; Environmental change; Pearl farming. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00613/72469/71614.pdf |
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| Hui, Belinda; Vonau, Vincent; Moriceau, Jacques; Tetumu, Roger; Vanaa, Vincent; Demoy-schneider, Marina; Suquet, Marc; Le Moullac, Gilles. |
| Cryopreservation is a valuable tool for genetic improvement programs. Several bivalve mollusc species have already been the subject of such programs and the Tahitian black pearl oyster industry is now planning the development of selective breeding for desirable traits in Pinctada margaritifera. The ability to cryopreserve spermatozoa would, therefore, offer significant benefits to the cultured black pearl industry. Spermatozoa were cryopreserved with CPA 0.7 M trehalose in 0.8 M Me2SO and a two-step freezing process was used: straws were first maintained in nitrogen vapour for 10 minutes, then directly plunged into liquid nitrogen and stored for one week before use. The viability of thawed sperm was 23 % lower than that of fresh sperm. When using thawed... |
| Tipo: Text |
Palavras-chave: Cryopreservation; Spermatozoa; Fertility; Larval rearing; Pearl oyster; Pinctada margaritifera. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00040/15098/12446.pdf |
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| Cochard, Jean-claude; Tiapari, Jerome; Teissier, Hinano; Le Moullac, Gilles. |
| Le cycle reproducteur de l’huître perlière a été étudié de septembre 2002 à août 2003 sur des échantillons de 30 individus initialement âgés de 2 ans prélevés à intervalles de 15 jours sur une filière d’élevage dans le lagon de Rikitea aux îles Gambier. Les paramètres biométriques suivis étaient les dimensions de la coquille, le poids total, le poids de chair humide et sèche. Le poids des principaux organes frais et séchés ont été mesurés pour l’évaluation de la croissance. L’état physiologique était évalué par la mesure de leur taux de glycogène. Le développement gonadique a été suivi par la mesure du poids de la gonade disséquée et par l’étude de coupes histologiques de 5 individus par prélèvement. La croissance a été relativement importante pendant les... |
| Tipo: Text |
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| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00182/29289/27773.pdf |
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| Le Moullac, Gilles; Schuck, Lucie; Chabrier, Sebastien; Belliard, Corinne; Lyonnard, Pierre; Broustal, Floriane; Soyez, Claude; Saulnier, Denis; Brahmi, Chloe; Ky, Chin-long; Beliaeff, Benoit. |
| The objective of this study was to observe the impact of temperature on pearl formation using an integrative approach describing the rotation of the pearls, the rate of nacre deposition, the thickness of the aragonite tablets and the biomineralizing potential of the pearl sac tissue though the expression level of some key genes. Fifty pearl oysters were grafted with magnetized nuclei to allow the rotation of the pearls to be described. Four months later, 32 of these pearl oysters were exposed to four temperatures (22, 26, 30 and 34°C) for 2 weeks. Results showed that the rotation speed differed according to the movement direction: pearls with axial movement (AM) had a significantly higher rotation speed than those with random movement (RM). Pearl... |
| Tipo: Text |
Palavras-chave: Magnetometer; Rotation speed; Nacre growth; Nacre thickness; Gene expression; Pmarg-Pif177. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00450/56196/57753.pdf |
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| 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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| Le Moullac, Gilles; Soyez, Claude; Sham-koua, Manaarii; Levy, Peva; Moriceau, Jacques; Vonau, Vincent; Maihota, Mayalen; Cochard, Jean-claude. |
| This study aimed to model the food intake of P. margaritifera in order to examine the relationship between food level and reproductive activity. The effect of microalgae concentration on ingestion rate and assimilation efficiency was studied over a broad concentration range, using a mixture of Isochrysis galbana and Chaetoceros gracilis. Reproductive effort was assessed using three microalgae concentrations of 0.5, 7 and 18 cell μL-1. Reproductive status was assessed by gonad development index (GDI) – the ratio of the gonad surface to the visceral mass surface – and histological analysis of the gonad based on the presence (continuous or discontinuous) or the absence of gonial cells (GC). Ingestion is a saturating function of seston concentration for... |
| Tipo: Text |
Palavras-chave: Pinctada margaritifera; Food level; Ingestion rate; Reproduction; Gametogenesis. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00050/16085/13562.pdf |
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| 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 |
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| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00176/28726/27183.pdf |
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| Van Wynsberge, Simon; Andrefouet, Serge; Gaertner-mazouni, Nabila; Wabnitz, Colette C. C.; Menoud, Mathilde; Le Moullac, Gilles; Levy, Peva; Gilbert, Antoine; Remoissenet, Georges. |
| Shell growth, reproduction, and natural mortality of the giant clam Tridacna maxima were characterized over a two-year-period in the lagoon of the high island of Tubuai (Austral Archipelago) and in the semi-closed lagoon of Tatakoto (Tuamotu Archipelago) in French Polynesia. We also recorded temperature, water level, tidal slope, tidal range, and mean wave height in both lagoons. Lower lagoon aperture and exposure to oceanic swells at Tatakoto than at Tubuai was responsible for lower lagoon water renewal, as well as higher variability in temperature and water level at Tatakoto across the studied period. These different environmental conditions had an impact on giant clams. Firstly, spawning events in the lagoon of Tatakoto, detected by gonad maturity... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00371/48214/48335.pdf |
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| Teaniniuraitemoana, Vaihiti; Huvet, Arnaud; Levy, Peva; Gaertner-mazouni, Nabila; Gueguen, Yannick; Le Moullac, Gilles. |
| The genomics of economically important marine bivalves is studied to provide better understanding of the molecular mechanisms underlying their different reproductive strategies. The recently available gonad transcriptome of the black-lip pearl oyster Pinctada margaritifera is a novel and powerful resource to study these mechanisms in marine mollusks displaying hermaphroditic features. In this study, RNAseq quantification data of the P. margaritifera gonad transcriptome were analyzed to identify candidate genes in histologically-characterized gonad samples to provide molecular signatures of the female and male sexual pathway in this pearl oyster. Based on the RNAseq data set, stringent expression analysis identified 1,937 contigs that were differentially... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00256/36768/35374.pdf |
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| Gardon, Tony; Reisser, Celine; Soyez, Claude; Quillien, Virgile; Le Moullac, Gilles. |
| Plastic pollution in the environment is increasing at global scale. Microplastics (MP) are derived from degradation of larger plastic items or directly produced in microparticles form (<5 mm). Plastics, widely used in structures and equipments of pearl farming, are a source of pollution to the detriment of the lagoon ecosystem. In order to evaluate the impact of MP on the physiology of Pinctada margaritifera, a species of ecological and commercial interests, adult oysters were exposed to polystyrene microbeads (micro-PS of 6 and 10 μm) for 2 months. Three concentrations were tested: 0.25, 2.5, 25 μg L-1 and a control. Ingestion and respiration rate and assimilation efficiency were monitored on a metabolic measurement system to determine the individual... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00435/54684/56104.pdf |
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| Le Moullac, Gilles; Soyez, Claude; Lyonnard, Pierre; Chabrier, Sébastien; Milhade, Leo; Gueguen, Yannick; Beliaeff, Benoit. |
| Non‐invasive functional exploration techniques can provide information on different aspects of general organism functioning and, unlike lethal or invasive techniques, allow individual organisms to be monitored for as long as necessary. For bivalves, a fairly wide variety of methods and instrumental means exist allowing physiology to be assessed on‐line while keeping animals alive and intact. The current range of non‐invasive techniques for bivalves consists of systems for measuring metabolic flows and valve activity, which can be used on bivalve molluscs for as long as an individual animal's characteristics (e.g. size) make this technically feasible. In this paper, we present some of these non‐invasive techniques with applications for pearl oyster and list... |
| Tipo: Text |
Palavras-chave: Bivalve; Filtration; Pearl rotation; Respiration; Valvometry. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00599/71161/69551.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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| Registros recuperados: 65 | |
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