|
|
|
| Registros recuperados: 115 | |
|
|
| Royer, J; Seguineau, Catherine; Park, K; Pouvreau, Stephane; Choi, K; Costil, K. |
| Two methods were used to estimate the reproductive output of female Pacific oysters reared in Normandy: histology with image analysis and ELISA (Enzyme-Linked lmmunoSorbent Assay) which allowed the quantification of egg protein. Condition indices, gonad area and gametogenetic stages of the oysters were determined in the entire population (males and females) between May and October 2005. All investigations were performed in 3 age classes: oysters in their first, second or third years (corresponding to spat, half-grown and market-sized oysters, respectively). Both quantitative histology and ELISA provided similar results in terms of reproductive effort (illustrated by the gonado-somatic index, GSI) except during the GSI drop, corresponding to spawning, which... |
| Tipo: Text |
Palavras-chave: Reproductive effort; Image analysis; Gametogenetic cycle; ELISA; Crassostrea gigas; Condition index. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4305.pdf |
| |
|
|
| Pouvreau, Stephane; Gangnery, Aline; Tiapari, Jerome; Lagarde, Franck; Garnier, Matthieu; Bodoy, Alain. |
| The gametogenic cycle and the reproductive effort of the blacklip pearl oyster, Pinctada margaritifera, cultivated in Takapoto lagoon were studied for a 1-year period (March 1997-April 1998) by bimonthly observations of gonadal sections, dry tissue weights and gonadal index in a population of pearl oyster composed of three age-groups. pearl oysters attained sexual maturity in the end of their first year (height approximate to 40 mm), implying that P. margaritifera is a late-maturing species in comparison with other Pteriidae. This species was also confirmed to be a marked protandrous successive hermaphrodite in culture, with 100 % of males at first maturity and 75 % in older pearl oyster (height > 120 mm). The general pattern of gametogenic activity,... |
| Tipo: Text |
Palavras-chave: French Polynesia; Reproductive effort; Reproductive cycle; Tropical aquaculture; Gametogenesis; Blacklip pearl oyster; Polynésie française; Effort de reproduction; Cycle de reproduction; Aquaculture tropicale; Gamétogenèse; Huître perlière. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-1391.pdf |
| |
|
|
| Moal, Jeanne; Bedier, Edouard; Fleury, Pierre-gildas; Langlade, Aime; Le Coguic, Yvette; Degremont, Lionel; Boudry, Pierre; Le Coz, Jean-rene; Pouvreau, Stephane; Enriquez-diaz, M.; Lambert, Christophe; Quere, Christele; Soudant, Philippe; Samain, Jean-francois. |
| Bi-parental families were produced in hatchery and tested in the field in 2001. Two sets of 5 families were constituted, selected on their high (R) and low (S) survival. These two sets were reared in Brittany from March to November 2002. Samplings were performed twice a month to obtain data on biometry, survival, reproductive cycle, biochemical composition, adenylate energy charge, hemolymph parameters (ions and defense system) and muscle strength. "R" and "S" oysters exhibited different reproductive effort and spawning strategy. "R" oysters allocated less energy in gonad than "S" ones and presented a complete spawning at the end of August contrary to the "S" which spawns partially. Mortality started in July when the seawater temperature reached 19 degree... |
| Tipo: Text |
Palavras-chave: Summer; Reproduction; Oyster culture; Mortality; Genetic diversity; Commercial species; Breeding. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3345.pdf |
| |
|
|
| Boudry, Pierre; Degremont, Lionel; Bedier, Edouard; Pouvreau, Stephane; Normand, Julien; Ernande, Bruno. |
| To date, the most significant method to genetically reduce reproductive effort in the Pacific oyster (Crassostrea gigas) has been through the production of triploids, especially since the development of tetraploid lines allowing the breeding of 'natural' triploids. Gametogenesis of triploid oysters is strongly reduced compared with diploids, although they are not fully sterile and can produce viable gametes and some progenies when crossed with diploids. Reduced reproductive allocation and higher heterozygocity are commonly proposed as the main reasons why triploids often present superior yield compared with diploids. Temperature and food availability are known to favour gametogenesis in triploids, but the existence of genetic variation for this trait... |
| Tipo: Text |
Palavras-chave: Selective breeding; Reproduction; Genetic variation; Crassostrea gigas; Pacific oyster; Genetic. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/acte-3445.pdf |
| |
|
|
| Samain, Jean-francois; Degremont, Lionel; Soletchnik, Patrick; Haure, Joel; Bedier, Edouard; Ropert, Michel; Moal, Jeanne; Huvet, Arnaud; Bacca, Helene; Van Wormhoudt, A; Delaporte, Maryse; Costil, K; Pouvreau, Stephane; Lambert, Christian; Boulo, Viviane; Soudant, Philippe; Nicolas, Jean-louis; Leroux, Frederique; Renault, Tristan; Gagnaire, Beatrice; Geret, Florence; Boutet, Isabelle; Burgeot, Thierry; Boudry, Pierre. |
| Summer mortality of Pacific oysters is known in several countries. However no specific pathogen has been systematically associated with this phenomenon. A complex combination of environmental and biological parameters has been suggested as the cause and is now starting to be identified. A high genetic basis was found for survival in oysters when a first generation (G1) was tested in three sites during summer. This paper presents a synthesis on physiological characteristics of two selected groups ('R' and 'S', from families selected for resistance and susceptibility to summer mortality respectively), of the second and third generations. R and S showed improvement or reduction of survival compared with the control in both field and laboratory trials... |
| Tipo: Text |
Palavras-chave: ROS; Temperature; Stress; Hemocytes; Reproduction; Genetic selection; Resistant oyster; Crassostrea gigas; Pacific Oyster; Summer mortality. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2809.pdf |
| |
|
|
| Thomas, Yoann; Pouvreau, Stephane; Alunno-bruscia, Marianne; Barille, Laurent; Gohin, Francis; Bryere, Philippe; Gernez, Pierre. |
| Aim The spread of non-indigenous species in marine ecosystems world-wide is one of today's most serious environmental concerns. Using mechanistic modelling, we investigated how global change relates to the invasion of European coasts by a non-native marine invertebrate, the Pacific oyster Crassostrea gigas. Location Bourgneuf Bay on the French Atlantic coast was considered as the northern boundary of C. gigas expansion at the time of its introduction to Europe in the 1970s. From this latitudinal reference, variations in the spatial distribution of the C. gigas reproductive niche were analysed along the north-western European coast from Gibraltar to Norway. Methods The effects of environmental variations on C. gigas physiology and phenology were studied... |
| Tipo: Text |
Palavras-chave: Biogeographical range expansion; Crassostrea gigas; DEB model; European coasts; Functional traits; Global change; Individual-based model; Invasive species; Remote-sensing. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00287/39828/38459.pdf |
| |
|
| |
|
|
| Pouvreau, Stephane; Tiapari, Jerome; Gangnery, Aline; Lagarde, Franck; Garnier, Matthieu; Teissier, Hinano; Haumani, G; Buestel, Dominique; Bodoy, Alain. |
| Growth of the black-lip pearl oyster, Pinctada margaritifera var. cumingi, was studied for an annual cycle, from March 1997 to April 1998, in the lagoon of Takapoto atoll (Tuamotu archipelago, French Polynesia). Growth in shell and in tissue were measured every 15 days on three successive age groups of cultivated pearl oysters. At the same time, hydrobiological parameters (temperature, salinity, oxygen concentration, suspended particulate matter), known to have influence on bivalve growth, were followed each week during culture. No seasonal trend was observed in hydrobiological parameters, except for temperature which varied between 26 degrees C and 31 degrees C. The potential food for pearl oysters (particulate organic matter, POM, mg l(-1)) was slightly... |
| Tipo: Text |
Palavras-chave: Pearl culture; Matter in suspension; Biochemical composition; Length weight relations ship; Tropical lagoon; Growth; Pinctada margaritifera. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-381.pdf |
| |
|
|
| Barille, Laurent; Lerouxel, Astrid; Dutertre, Mickael; Haure, Joel; Barille, Anne-laure; Pouvreau, Stephane; Alunno-bruscia, Marianne. |
| We compared growth simulations by dynamic energy budget (DEB) and scope for growth (SFG) models of the Pacific oyster Crassostrea gigas, cultivated in Bourgneuf Bay on the French Atlantic coast. This bay is located at a latitude in the middle of the European range of the species, and is characterized by high concentrations of suspended particulate matter (SPM) and a marked gradient between high-turbidity sites in the north (daily SPM > 500 mg L-1) and intermediate-turbidity sites in the south. The models use two forcing variables: seawater temperature and food density. We tested two indices of food availability: chlorophyll a and microalgal concentrations. In the SFG model, food intake is simulated by a type-II Holling functional response, as in the DEB... |
| Tipo: Text |
Palavras-chave: Oyster; Dynamic Energy Budget model; Scope for growth model; Turbidity. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00043/15433/12783.pdf |
| |
|
|
| Cugier, Philippe; Frangoudes, Katia; Blanchard, Michel; Mongruel, Remi; Perez, Jose; Le Mao, Patrick; Robin, T.; Fontenelle, Guy; Mazurie, Joseph; Cayocca, Florence; Pouvreau, Stephane; Olivier, F.. |
| Tipo: Text |
|
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00026/13707/10862.pdf |
| |
|
| |
|
|
| Delaporte, Maryse; Soudant, P; Lambert, C; Moal, Jeanne; Pouvreau, Stephane; Samain, Jean-francois. |
| The aim of this study was to test the effect of food quantity on energy storage and defense capacities of oysters during a reproductive cycle. One-year-old Crassostrea gigas oysters were fed two different dietary rations (4% and 12% of oyster dry weight in algal dry weight per day) in controlled experimental conditions over an annual cycle. Oyster dry weights, carbohydrate and lipid contents, energetic adenylate charge, and hemocyte parameters of oysters were significantly affected by reproductive processes related to seasonal temperature variation and, to a lesser extent, by the dietary rations. Energy parameters decreased during gametogenesis as gonads developed then increased during the gonad resorption phase. The additional energy provided to oysters... |
| Tipo: Text |
Palavras-chave: Reactive oxygen species production; Reproduction; Phagocytosis; Hemocyte parameters; Energy storage; Crassostrea gigas. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1549.pdf |
| |
|
|
| Dauphin, Yannicke; Ball, Alexander D.; Castillo-michel, Hiram; Chevallard, Corinne; Cuif, Jean-pierre; Farre, Bastien; Pouvreau, Stephane; Salome, Murielle. |
| Cultivation of commercial oysters is now facing the possible influence of global change in sea water composition, commonly referred to as "ocean acidification". In order to test the potential consequence of the predicted environmental changes, a cultivation experiment was carried out. The left and right valves of the oyster shell Crassostrea gigas differ in their structure; moreover, lenses of non compact layers are irregular. The shell layers of juvenile C. gigas are studied using a variety of highly spatially resolved techniques to establish their composition and structure. Our results confirm the presence of three different calcitic structural types. The role of the lenses of chalky layers is not yet deciplered. Despite a common mineralogy, the... |
| Tipo: Text |
Palavras-chave: Biomineral; Mollusc shell; Infrared spectroscopy; Laser confocal Microscope; Micro-XANES. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00118/22890/20797.pdf |
| |
|
|
| Bernard, I.; Massabuau, J. -c.; Ciret, P.; Sow, M.; Sottolichio, Aldo; Pouvreau, Stephane; Tran, D.. |
| The precise environmental conditions under which broadcast spawners spawn in the field remain largely unknown. We investigated this issue in the oyster Crassostrea gigas using three different methods at different time scales in two traditional oyster farming areas of the French Atlantic Coast, the Bay of Arcachon and Marennes-Oléron. We directly recorded spawning at high temporal resolution using high-frequency non-invasive (HFNI) valvometry from 2007–2014 and measured the dry mass and oyster larvae abundance in 2008 and 2009. We analyzed a 29-yr series of oyster D-larvae numbers in the Bay of Arcachon (1982–2010). By combining these three approaches, we demonstrated that during the summer months at both sites, spawning in C. gigas occurs in the morning or... |
| Tipo: Text |
|
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00312/42335/41666.pdf |
| |
|
|
| Pouvreau, Stephane; Bodoy, Alain; Buestel, Dominique. |
| In situ clearance rate (CR) and biodeposition of the black pearl oyster, Pinctada margaritifera, were followed during several field experiments from 1996 to 1998 in the lagoon of Takapoto. Serial measurements of total particulate matter (TPM, mg l(-1)), particulate inorganic matter (PLM, mg l(-1)), and particulate organic matter (POM, mg l(-1)) were related to meteorological conditions, especially wind speed. As a general case, POM and PLM increased with wind speed. Nevertheless, PLM increased faster than POM so that the organic content (OC, %) of the TPM decreased progressively when wind speed increased. These TPM variations induced direct changes in feeding processes of P. margaritifera. CR (l h(-1)) averaged 22 l h(-1) for a pearl oyster of 1 g dry... |
| Tipo: Text |
Palavras-chave: Biodeposition; Clearance rate; Seston; Filter feedings behaviour; Tropical lagoon; Tropical bivalve. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-382.pdf |
| |
|
|
| Rico Villa, Benjamin; Pouvreau, Stephane; Robert, Rene. |
| Ingestion, growth and metamorphosis of Pacific oyster, Crassostrea gigas, larvae were studied under controlled conditions of food density and temperature using a combination of a flow-through rearing system and a hydrobiological monitoring device. In a first experiment larvae were exposed to three different phytoplankton densities (12, 20 and 40 cells μl-1) while in a second trial larvae were reared at five different temperatures (17, 22, 25, 27 and 32°C). Both food concentration and temperature significantly affected the larval physiology throughout the entire development from D-veliger to young spat. Larvae survived over a wide range of both environmental parameters with high survival at the end of experiments. The feeding functional response... |
| Tipo: Text |
Palavras-chave: Temperature; Food; Growth; Ecophysiology; Bivalve larvae; Crassostrea gigas. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4747.pdf |
| |
|
|
| Lartaud, Franck; Emmanuel, Laurent; De Rafelis, Marc; Pouvreau, Stephane; Renard, Maurice. |
| Compared to oxygen isotopes, the carbon isotope composition of biogenic carbonates is less commonly used as proxy for palaeoenvironmental reconstructions because shell delta C-13 is derived from both dissolved inorganic (seawater) and organic carbon sources (food), and interactions between these two pools make it difficult to unambiguously identify any independent effect of either. The main purpose of this study was to demonstrate any direct impact of variable food supply on bivalve shell delta C-13 signatures, using low/high rations of a C-13-light mixed algal diet fed to 14-month-old (adult) cultured Japanese Crassostrea gigas under otherwise essentially identical in vitro conditions during 3 summer months (May, June and July 2003, seawater temperature... |
| Tipo: Text |
|
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/2010/publication-7435.pdf |
| |
|
|
| Gonzales, Arriagada; Bernard, Ismael; Maurer, Daniele; Auby, Isabelle; Gasmi, Sonia; Pouvreau, Stephane; David, Valerie. |
| Arcachon Bay is one of the most important spat-supplying area for the French oyster production. During the last 16 years, the local economic activity of spat production has been threatened recurrently by a high interannual variability of seed harvesting. This threatened spat production was attributed to reproductive problems highlighted by both a delay in oyster spawning and a decrease of small larvae abundances since 1995. Recent works showed that these two reproduction indices seem closely related to climate change that might controls the phytoplankton communities of the Bay. Food availability in term of quantity and quality appears thus as a serious track to understand the reproductive problems of oyster in the Arcachon Bay. The aim of this work was... |
| Tipo: Text |
|
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00257/36828/35454.pdf |
| |
|
|
| 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 |
| |
|
|
| Petton, Sebastien; Pouvreau, Stephane; Dumas, Franck. |
| Coastal waters are subject to great environmental and anthropogenic pressures. The diffusion and the transport of these waters are a key element for environmental, ecological and economic management. There are numerous indicators of hydrological characteristics based on theories of transport time scale. However, these indicators strongly depend on the geographical shape of the studied area and tend to give information after long integration time periods, generally on the order of weeks. Here, to qualify a coastal area’s dispersion more precisely, we combined two Lagrangian approaches and estimated a local diffusivity. This paper presents the numerical implementation and the results obtained over a tidally flushed, semi-enclosed water body located at... |
| Tipo: Text |
Palavras-chave: Hydrodynamic model; Lagrangian analysis; Barycentric repositioning method; Local diffusivity. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00609/72068/70919.pdf |
| |
| Registros recuperados: 115 | |
|
|
|
