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| Registros recuperados: 115 | |
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| Buestel, Dominique; Pouvreau, Stephane; Tiapari, Jerome; Bougrier, Serge; Chabirand, Jean-michel; Geairon, Philippe; Fougerouse, A. |
| A study of pearl oysters Pinctada margaritifera growth and mortality was done on a monthly basis between June 1990 and September 1991 in Takapoto atoll (Tuamotu archipelago). Meanwhile, sampling parameters representative of bivalves food showed a remarquable spatial stability whithin the lagoon. The amplitude of temporal variability varied in the order of some days. Carrying capacity appears low : energetic content of particulate material in waters is about 2 joules/liter, ten times lower than in temperate areas. On the opposite, seasonal effect is reduced and particulate food is always available. Oysters rearing conditions were appropriate during the studied period with a low mortality rate and a regular growth in size (from 97 mm to 136 mm). Pearls... |
| Tipo: Text |
Palavras-chave: Atoll; Pearl oyster; Carrying capacity; Growth; Pinctada margaritifera; Atoll; Huître perlière; Capacité Trophique; Croissance; Pinctada margaritifera. |
| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/1995/rapport-1642.pdf |
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| Pouvreau, Stephane; Morizur, Yvon. |
| This study provides some background on the set nets and the use of the gears. The various metiers using set nets are presented by region and maritime basin detailing the target species. The physical characteristics of nets (type, mesh), the number of vessels engaged in the activity, fishing areas, the amount of material used and the composition of the catch are inventoried by target species. Intraspecific selectivity for the main target species of set nets is examined in light of the available size composition of catches of turbot, brill, monkfish, pollack, red mullet, bass, common sole, rays, hake, spider crab, lobster. Few differences exist between the nets (single layer) and trammel nets except for the lobster. Minimum mesh sizes are suggested by target... |
| Tipo: Text |
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| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/00049/16036/13511.pdf |
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| Morizur, Yvon; Tregenza, N; Heessen, H; Beerow, S; Pouvreau, Stephane. |
| Incidental mammal catch and the composition of the fish catch were studied in pelagic trawl fisheries in the North-East Atlantic. Several seasonal European fisheries were investigated with scientific observation on the fishing vessels. A total of 379 days at sea were observed . The sampled fisheries were horsemackerel (Dutch, French), herring (Irish), mackerel (UK), pilchard (UK , French) and other French fisheries (hake, tuna, bass, black bream, anchovy). Unintentional catches of dolphins were recorded in four of the investigated fisheries (Dutch horsemackerel, French tuna, French hake and French sea bass) at a rate of 1 dolphin per 100 tow hours; Grey seals were caught in the Irish herring fishery at a rate of 4 individuals per 100 tow hours. The fish... |
| Tipo: Text |
Palavras-chave: Albacore; Bluefin tuna Bass Black bream Whiting Hake Anchovy Pilchard Mackerel Horsemackerel Seal Cetacean Incidental mammal catch Reasons for discarding Discards By catch Pelagic trawl. |
| Ano: 1996 |
URL: https://archimer.ifremer.fr/doc/1996/rapport-1236.pdf |
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| Morizur, Yvon; Pouvreau, Stephane; Guenole, Annie. |
| Observers were set on board of fishing vessels from North Brittanny ports during one full year (1992-93). This study granted by EC Commission (contract CE/DGXIV-C-1 n° 1992/06) was a first approach for assessing French discards in the western English Channel. It identifies the main species discarded and produces a rough estimate of discard rates and size compositions in each métier targeting fish. The major reasons for variability were explained. Size compositions of catches and discards were provided in order to permit better estimates of the mortality induced by fishing operations. The fixed nets observed were large mesh nets (270 to 360 mm) targeting monkfish and small mesh nets (<200 mm) targeting coastal resources. Netting was found to be more... |
| Tipo: Text |
Palavras-chave: France; Western English Channel; Bottom trawls; Fixed nets; Fisheries; Discards. |
| Ano: 1996 |
URL: https://archimer.ifremer.fr/doc/1996/rapport-1730.pdf |
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| 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 |
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| Buestel, Dominique; Pouvreau, Stephane. |
| Results of research concerning the food of the pearl oyster Pinctada mai margaritifera are presented, by taking Takapoto atoll (Tuamotu archipelago, French Polynesia) as a study site. Monthly sampling of several parameters representative of bivalve environment and food (water temperature, salinity, mineral and organic matter, proteins, lipids and carbohydrates, chlorophyll a and phaeopigments) confirm and increase knowledge of the Takapoto lagoon hydrobiology. The variability of these parameters was analysed. Takapoto lagoon showed a remarkable spatial stability. Temporal variations showed a low seasonal trend. Local meteorology (wind, precipitation) had an influence on short-term variability (especially for mineral matter). Night and day rhythm also... |
| Tipo: Text |
Palavras-chave: Pinctada margaritifera; Matière en suspension; Capacité trophique; Huı̂tre perlière; Atoll; Pinctada margaritifera; Suspended matter; Carrying capacity; Pearl oyster; Atoll. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00000/10529/7078.pdf |
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| Fagon, N.; Le Souchu, Pierrick; Lefebvre, Sebastien; Pouvreau, Stephane. |
| Force est de constater que, malgré un intérêt croissant depuis les 20 dernières années en matière d'écophysiologie des mollusques, il n'existe, à notre connaissance, aucun système réellement adapté à la mesure en continu et de façon concomitante des principales fonctions écophysiologies des mollusques filtreurs (notamment consommation et filtration). Faisant suite à la réalisation d'un cahier des charges et d'une version préliminaire d'un système, le but du présent projet est de doter la Station Expérimentale d'Argenton (entité expérimentale de l'UMR « Physiologie et Ecophysiologie des Mollusques Marins) de deux systèmes automatisés et opérationnels de mesures de l'écophysiologie des mollusques filtreurs. Après un bref rappel des principes de mesures des... |
| Tipo: Text |
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| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00306/41769/40982.pdf |
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| 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 |
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| 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 |
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| Pouvreau, Stephane; Bacher, Cedric; Heral, Maurice. |
| A model of bioenergetics of the black pearl oyster (Pinctada margaritifera) was built to simulate growth, reproduction and spawning in suspended culture at field sites in Takapoto lagoon (French Polynesia). This model was based on allometric scaling of physiological functions and scope for growth (SFG) calculations. The input functions were clearance rate (CR, 1 day(-1)), retention efficiency (RE, %) for each kind of particle encountered in suspended matter, pseudofaeces and faeces productions (PF and F, mg C day(-1)), excretion and respiration rate (U and R, mg C day(-1)). The assimilated carbon (i.e., SFG, mg C day(-1)) was partitioned to the three internal state variables (somatic tissue, shell and gonad) according to the asymptotic increase of the... |
| Tipo: Text |
Palavras-chave: Pearl farming; Food depletion; Scope for growth; Carrying capacity; Suspension feeding; Tropical lagoon. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-380.pdf |
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| Soletchnik, Patrick; Le Moine, Olivier; Faury, Nicole; Guilpain, Patrice; Geairon, Philippe; Razet, Daniel; Seugnet, Jean-luc; Robert, Stephane; Ropert, Michel; Simonne, Charlotte; Hugonnet, Virginie; Moal, Jeanne; Pouvreau, Stephane; Huvet, Arnaud; Samain, Jean-francois; Lambert, Christophe; Soudant, Philippe; Frouel, Stephane; Choquet, Gwenaelle; Delaporte, Maryse; Paillard, Christine. |
| Four laboratories are involved in this multidisciplinary study: the Conchological Laboratory of Normandie (LCN), the Invertebrates Physiology Laboratory (LPI), the Université Bretagne Occidentale (LEMAR IHP) and the Conchological Laboratory of Poitou-Charentes (LCPC). The part of the study which is presented here (thematics "Coastal ecology") was produced in collaboration with the LCN. The data on the Bay of Veys was collected by Michel Ropert. This study aims at observing the "sites" effect on mortality and on the general biology of the animal, as well as measuring some environmental elements (e.g. water temperature, etc.). The geographical sites are Gefosse in the Bay of Veys (East Cotentin) and the Ronce bank in the south of the Marennes Oléron Bay. The... |
| Tipo: Text |
Palavras-chave: Immunologie; Physiologie; Paramètres environnementaux; Croissance; Ecologie côtière; Baies des Veys Cotentin; Ronce Charente Maritime; Comparaison sites; Reproduction; Mortalités; Crassostrea gigas; Huîtres. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/acte-3405.pdf |
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| Faury, Nicole; Geairon, Philippe; Moal, Jeanne; Pouvreau, Stephane; Razet, Daniel; Ropert, Michel; Soletchnik, Patrick. |
| Proximate biochemical analysis (proteins, lipids and carbohydrates) are performed on a regular basis by the various laboratories fom the Aquaculture Resources Directorate. Methods initially developed to analyse hydrological parameters were firstly transfered to assess meat components.1t appears now important to review and update the commonly used methods (Lowry et al., (1951), Dubois et al.,(l956), Marsh et Weinstein, (1966)), for our specifie purposes. A round table was organized to facilitate discussion among researchers and technicians from both Directorates 'Aquaculture Resources' and 'Product Valorization'and external partners, University of Caen. Several communications reviewing former and recent studies were done. Colleagues from the Directorate... |
| Tipo: Text |
Palavras-chave: Glycogen; Carbohydrates; Lipids; Proteins; Methods comparison; Proximate biochemical composition; Glycogène; Carbohydrates; Lipiedes; Protéines; Comparaison méthodes; Composition biochimique. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/rapport-6378.pdf |
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| Delaporte, Maryse; Moal, Jeanne; Soudant, Philippe; Lambert, Christophe; Pouvreau, Stephane; Enriquez, Martha; Degremont, Lionel; Soletchnik, Patrick; Gagnaire, Beatrice; Ropert, Michel. |
| In the frame of MOREST project, a common biological material, resulting of a mixture of different families produced in experimental hatchery, was reared in two different environmental fields : Normandy and Charente. Concomitantly, a pool was conditioned at the Ifremer Argenton hatchery with three different algae levels : 4%, 8% and 12% of algal dry weight per oyster dry weight. During the experiments, five immune parameters were studied in parallel with survival rate and reproductive status (stages and intensity). Site location, seasonal variations and experimental diet level clearly influenced oyster immune parameters. Haemocyte counts were higher for oysters reared in Normandy than those reared in Charente and in hatchery. Granulocyte percentage was... |
| Tipo: Text |
Palavras-chave: Defense mechanisms; Nutrition; Seasonal variations; Physiology; Crassostrea gigas; Pacific oysters. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3500.pdf |
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| 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 |
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| Savina, Marie; Pouvreau, Stephane. |
| A comparative ecophysiological study was carried out in September and November 2002 for two bivalves, Paphia rhomboides and Glycymeris glycymeris, which are significantly harvested in the Western Channel (French coast). Individual measurements of clearance and respiration rates were performed for both species, in several experimental conditions of temperature and phytoplankton concentrations. Those conditions were chosen to be in the range of those commonly observed in the subtidal area of the Western Channel. The mean value of clearance rate and oxygen consumption obtained from continuous data recording did not reveal any significant influence of temperature in the investigated range, but a significant difference between P rhomboides and G. glycymeris.... |
| Tipo: Text |
Palavras-chave: Filter feeding; Bivalves; Glycymeris glycymeris; Paphia rhomboides; Scope for growth; Ecophysiology. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-379.pdf |
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| Pouvreau, Stephane; Davenel, A; Quellec, S; Rambeau, M. |
| Nuclear Magnetic Resonance (NMR) is increasingly used in biology and the appearance of imaging and structural and/or metabolic spectroscopy (MRI/MSR) platforms (Rennes, Strasbourg, Marseille...) devoted to this small animal shows the recent keen interest in these research techniques. However, to this day and to our knowledge, no approach of this style has been developed for sea molluscs and even less so for the cup oyster, Crassostrea gigas. Because of its economic importance, this bivalve mollusc is the subject of much research in physiology, to the point of becoming, at IFREMER, a biological model for marine invertebrates. Nonetheless, most of the methodologies developed for studying it are destructive, which (1) prevents individual follow-up, (2)... |
| Tipo: Text |
Palavras-chave: Nuclear Magnetic Resonance; Anatomy; Biometry; Physiology; Bivalvia. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/rapport-1560.pdf |
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| Fabioux, Caroline; Huvet, Arnaud; Lelong, C; Robert, Rene; Pouvreau, Stephane; Daniel, Jean-yves; Mingant, Christian; Le Pennec, M. |
| The oyster vasa-like gene was previously demonstrated to be specifically expressed in germline cells of adult oysters Crassostrea gigas. In the present study, this gene was used as a molecular marker to establish the developmental pattern of germline cells during oyster ontogenesis. using whole-mount in situ hybridization and real-time PCR. The Oyvlg transcripts appeared to be localized to the vegetal pole of unfertilized oocytes and maternally transmitted to embryos. At early development, these maternal transcripts were observed to segregate into a single blastomere, from the CD macromere of 2-cell stage to the 4d mesentoblast of blastula. From late blastula stage, the mesentoblast divided into two cell clumps that migrated to both sides of the larvae... |
| Tipo: Text |
Palavras-chave: Primordial germ cells; Oyster vasa like gene; Germline; Development; Crassostrea gigas. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-648.pdf |
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| Registros recuperados: 115 | |
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