Consulta: creatorFacets:"Levy, Peva"
Registros recuperados: 21
Data/hora: 01/06/2024 11:22:18

Characterization of molecular processes involved in the pearl formation in Pinctada margaritifera for a sustainable development of pearl farming industry in French Polynesia
Provedor de dados: 5
Autores: Gueguen, Yannick; Montagnani, Caroline; Joubert, Caroline; Marie, Benjamin; Belliard, Corinne; Tayale, Alexandre; Fievet, Julie; Levy, Peva; Piquemal, David; Marin, Frederic; Le Moullac, Gilles; Ky, Chin-long; Garen, Pierre; Lo, Cedrick; Saulnier, Denis.
Tahiti’s pearl farming industry plays a major socio-economic role in French Polynesia. In an increasingly competitive market where the production of high quality pearls becomes essential, research can help secure and ensure sustainable production. In that context, Ifremer, in close collaboration with the “direction des resources marines” (French Polynesian government agency) has developed research projects on the “sustainable development of pearl farming”. This program is organized along 3 axes: (1) understanding the animal physiology and initiating a genetically selective breeding program of donor oysters; (2) understanding pearl oyster larvae dispersal and recruitment; (3) understanding the molecular mechanisms underlying biomineralization processes...
Tipo: Text
Palavras-chave: Pearl oyster; Biomineralization; Pinctada margaritifera.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00167/27840/26049.pdf

Molecular detection of betanodavirus from the farmed fish, Platax orbicularis (Forsskal) (Ephippidae), in French Polynesia
Provedor de dados: 5
Autores: David, R.; Treguier, Cathy; Montagnani, Caroline; Belliard, Corinne; Levy, Peva; Nedelec, Georges; Joufoques, Vaiana; Remoissenet, G.; Gueguen, Yannick; Cochennec-laureau, Nathalie.
Tipo: Text
Palavras-chave: Betanodavirus; Detection; French Polynesia; Genotype; Platax orbicularis.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00003/11380/7972.pdf

Bilan final 2004-2007 du Réseau de Veille Zoosanitaire REPANUI des huîtres perlières Pinctada margaritifera en Polynésie francaise
Provedor de dados: 5
Autores: Saugeon, Cecile; Fougerouse, Angelique; Pellan, Antoine; Levy, Peva; Cochennec-laureau, Nathalie.
De nombreuses pathologies affectent les mollusques, dont les huîtres perlières. Celles-ci peuvent être sensibles à des maladies, ce qui peut entraîner parfois de fortes mortalités au sein d’une population. La présence de certains agents pathogènes dans la région Asie-Pacifique ainsi que les fortes mortalités dans les années 1985 sur le cheptel de Pinctada margaritifera en Polynésie française, permet de se rendre compte de la vulnérabilité de la filière perlicole.  De part l’importance socio-économique de la perliculture en Polynésie française, le Service de la Perliculture, en collaboration avec l’Ifremer de Tahiti, a mis en place en 2003 un réseau de surveillance épidémiologique des pathologies de l’huître perlière P. margaritifera (REPANUI). Après cinq...
Tipo: Text
Ano: 2007
URL: http://archimer.ifremer.fr/doc/00168/27883/26137.pdf

Gonad transcriptome analysis of pearl oyster Pinctada margaritifera: identification of potential sex differentiation and sex determining genes
Provedor de dados: 5
Autores: Teaniniuraitemoana, Vaihiti; Huvet, Arnaud; Levy, Peva; Klopp, Christophe; Lhuillier, Emeline; Gaertner-mazouni, Nabila; Gueguen, Yannick; Le Moullac, Gilles.
Background  Black pearl farming is based on culture of the blacklip pearl oyster Pinctada margaritifera (Mollusca, lophotrochozoa), a protandrous hermaphrodite species. At first maturation, all individuals are males. The female sex appears progressively from two years old, which represents a limitation for broodstock conditioning for aquaculture production. In marine mollusks displaying hermaphroditic features, data on sexual determinism and differentiation, including the molecular sex determining cascade, are scarce. To increase genomic resources and identify the molecular mechanisms whereby gene expression may act in the sexual dimorphism of P. margaritifera, we performed gonad transcriptome analysis.  Results  The gonad transcriptome of P. margaritifera...
Tipo: Text
Palavras-chave: Pinctada margaritifera; Gametogenesis; Transcriptome; Differential expression; Sex determinism.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00201/31194/29593.pdf

Identifying Robust Proxies of Gonad Maturation for the Protandrous Hermaphrodite     Tridacna maxima     (Röding, 1798, Bivalvia) from Individual to Population Scale
Provedor de dados: 5
Autores: Menoud, Mathilde; Van Wynsberge, Simon; Le Moullac, Gilles; Levy, Peva; Andrefouet, Serge; Remoissenet, Georges; Gaertner-mazouni, Nabila.
Monitoring gonadmaturation for protandrous and functional hermaphrodite species such as the giant clamTridacna maxima is difficult due to the juxtaposition and relative proportion ofmale and female tissues in the gonad [gonadal sex ratio (GSR)]. Here, the relevance of the widely used gonadosomatic index (GSI) as proxy of giant clam gonad maturation is tested with a large dataset (n = 265). Gonadosomatic index is compared with other indices, namely the proportion of the male part harboring spermatozoids, the proportion of empty oocyte follicles, the mean oocyte diameter, and the oocyte elongation. At gonad scale, high index variability highlighted partial spawning. At individual scale, male and female maturation proxies were contrasted, showing either...
Tipo: Text
Palavras-chave: Giant clam; Marine bivalve; Reproduction; Spawn; Tatakoto atoll; Histology; Tridacna maxima.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00333/44441/44111.pdf

Development of an antiseptic procedure to improve retention rates during the grafting process of black-lip oyster, Pinctada margaritifera
Provedor de dados: 5
Autores: Cochennec, Nathalie; Haffner, Philippe; Levy, Peva; Saulnier, Denis; Fougerouse, A.; Langy, Sandra.
In French Polynesia, black pearl cultivation now takes place on about 30 of the 118 atolls or islands. This activity has largely replaced copra, coconut oil and fishing as a source of income. Around 1,000 pearl farms, generally small ones of less than 5 ha, are registered. The pearl farms are mainly owned by families. In 1998, about 7,000 persons were employed in theentire pearl industry, from production to retailing. In value, this activity represents the first exportation of French Polynesian products. From 1988 to date, exports increased exponentially before leveling. Starting with less than two kilograms in 1972, exports have now stabilized at Il tons of "black" pearls.
Tipo: Text
Palavras-chave: Vibrio; Microbiology; Grafting process; Pinctada margaritifera.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-4928.PDF

Réseau de surveillance des polluants anthropiques dans les lagons de Polynésie française. Rapport final - Septembre 2014. Contrat de projet Etat-Pays
Provedor de dados: 5
Autores: Bernagout, Solene; Bouisset, Patrick; Leclerc, Gael; Rua, Jean; Nohl, Marine; Garen, Pierre; Levy, Peva; Tetaura, Nono-lewis; Poroi, Destremeau; Sham Koua, Manaarii; Liao, Vetea; Bosserelle, Pauline; Planes, Serge; Espiau, Benoit.
La mise en place d’un réseau d’observation de la qualité des eaux lagonaires de Polynésie française, financé par le contrat de projet Etat – Pays, a été initiée mi 2012 pour une durée de deux ans. Durant un à trois semestres la contamination in situ a été suivie sur 6 sites : Vairao et la baie de Phaéton à Tahiti, Moorea (Vaiare), Huahine (Faie), Maupiti et Rangiroa. Le mollusque bioindicateur utilisé est l’huître perlière Pinctada margaritifera. Après transplantation et 4 mois d’immersion sur site, la mesure dans les chairs de la radioactivité gamma n’a pas permis de détecter de radionucléides artificiels, cependant du césium 137 a été mesuré dans les sédiments sur 2 sites. Le plutonium (émetteur alpha) est présent en faibles quantités dans les chairs....
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00249/35975/34499.pdf

Effect of food conditioning on gonadic activity in the oyster Pinctada margaritifera
Provedor de dados: 5
Autores: Le Moullac, Gilles; Hui, Belinda; Vonau, Vincent; Levy, Peva; Cochard, Jean-claude.
Preliminary experiments allowed defining basic requirements of Pinctada margaritifera for somatic and gonadic growth in controlled conditions. This study was continued by observation of the gametogenesis at a cellular level. In April/May 2008, 125 oysters were conditioned for 30 days in 25 tubular tanks (30 L). Water was renewed 4 times/hour. A mixed (v:v) diet of Isochrysis galbana (T-Iso) and Chaetoceros gracilis was supplied continuously. A control batch of 125 oysters was maintained in trays in the lagoon. An initial sample of 30 individuals was made. Gonadic changes were first characterized using a gonadal development index (GDI) based on the ratio of the gonad area to the total visceral mass area on a sagittal section of the body. Histological...
Tipo: Text
Palavras-chave: Pearl oyster; Reproduction; Gametogenesis; Broodstock.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00029/14010/11196.pdf

Characterization of two new genes implicated in mineralization process of Pinctada margaritifera
Provedor de dados: 5
Autores: Cochennec-laureau, Nathalie; Fleury, Elodie; Belliard, Corinne; Levy, Peva.
A transplant is a complex surgical procedure performed to obtain a pearl after about 12 to 18 months. One of the key steps in this procedure is the transfer of the graft (piece of mantle) from the donor oyster. A functional relationship exists between the coating nature of the pearl and the cellular structure of the pearl bag portion of the graft. We have identified two genetic markers of biomineralisation in Pinctada margaritifera, the pearl oyster: Perline and Calcine, responsible for secretion of aragonite and calcite, respectively. After isolating and sequencing a portion of each of these genes, we verified the specificity of these sequences using molecular methods (RT-PCR, in situ hybridisation) and biocomputing methods (alignments, phylogenetic...
Tipo: Text
Ano: 2005
URL: http://archimer.ifremer.fr/doc/00168/27888/26143.pdf

Effect of temperature, food availability, and estradiol injection on gametogenesis and gender in the pearl oyster     Pinctada margaritifera
Provedor de dados: 5
Autores: 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
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00285/39638/38184.pdf

Proteinaceous exotoxins of shrimp-pathogenic isolates of Vibrio penaeicida and Vibrio nigripulchritudo
Provedor de dados: 5
Autores: Aguirre-guzman, Gabriel; Labreuche, Yannick; Ansquer, Dominique; Espiau, Benoit; Levy, Peva; Ascencio, Felipe; Saulnier, Denis.
The pathogenicity of two V. penaeicida strains, AM101 and KH-1, with different geographic origin, and V. nigripulchritudo strain AM102, were investigated in juvenile blue shrimp species Litopenaeus stylirostris. Alive bacteria and protein fractions (PFs) obtained from cell-free supernatants (CFS) were used in experimental challenges. Strains AM102, AM101, and KH-1 produced respectively 60, 54 and 12% mortality at 96h after infection using 104 cfu mL-1 of bacterial suspension. Exocellular toxin-like factors were evidenced in CFS from the New Caledonian strains (AM102 and AM101) but not the Japanese strain (KH-1). At 48h post injection of each CFS, mortality rates were respectively 96,98 and 5% when these strains were cultivated at 20°C, whereas only O,16...
Tipo: Text
Palavras-chave: Pathogenicity; Exotoxin; Shrimp; Litopenaeus stylirostris; Vibrio nigripulchritudo; Vibrio penaeicida.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/publication-2807.pdf

Rapid and sensitive PCR detection of Vibrio penaeicida, the putative etiological agent of syndrome 93 in New Caledonia
Provedor de dados: 5
Autores: 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

Feeding the pearl oyster Pinctada margaritifera during reproductive conditioning
Provedor de dados: 5
Autores: 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

Bilan 2005-2006 du Réseau de Veille Zoosanitaire des huîtres perlières, Pinctada margaritifera, en Polynésie française
Provedor de dados: 5
Autores: Cochennec-laureau, Nathalie; Fougerouse, Angelique; Pellan, Antoine; Levy, Peva.
En 2005 et 2006, un total de 1333 analyses réparties en 1109 huîtres perlières, P. margaritifera, 93 pipi, P. maculata, 27 chama, Chamidae sp, 46 kapi kapi, Saccostrea cucullata et 58 Isognomon sp. ont été effectuées dans le cadre du REseau de PAthologie des huîtres perlières (REPANUI). Les analyses histologiques ont révélé comme les années précédentes la présence de sporozoaires de type grégarine, des parasites de type Rickettsien, des kystes de cestodes (Tylocephalum sp.). Une infection par des vers trématodes a été détectée chez S. cucullata.  Depuis la mise en place de cette surveillance active en 2003, aucun agent pathogène à déclaration obligatoire de la liste de l’Office International des Epizooties (OIE) n’a été diagnostiqué, confirmant le bon état...
Tipo: Text
Ano: 2006
URL: http://archimer.ifremer.fr/doc/00168/27882/26136.pdf

Growth, Survival and Reproduction of the Giant Clam Tridacna maxima (Röding 1798, Bivalvia) in Two Contrasting Lagoons in French Polynesia
Provedor de dados: 5
Autores: 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
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00371/48214/48335.pdf

Molecular Signatures Discriminating the Male and the Female Sexual Pathways in the Pearl Oyster Pinctada margaritifera
Provedor de dados: 5
Autores: 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
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00256/36768/35374.pdf

Study of the ontogeny of the orbicular batfish (Platax orbicularis)
Provedor de dados: 5
Autores: Bardon-albaret, Agnes; Gasset, Eric; Teissier, Alexandre; Teiri, W; Maamaatuaiahutapu, M; David, R; Tayale, Alexandre; Belliard, Corinne; Levy, Peva; Basset, Caline; Sicard, Julien; Magre, Kevin; Herne, Antoine; Reverter, Myriam; Sasal, Pierre; Coves, Denis; Saulnier, Denis.
Tipo: Text
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00281/39246/37819.pdf

A histological examination of grafting success in pearl oyster Pinctada margaritifera in French Polynesia
Provedor de dados: 5
Autores: Cochennec-laureau, Nathalie; Montagnani, Caroline; Saulnier, Denis; Fougerouse, Angelique; Levy, Peva; Lo, Cedrik.
Pearl oyster grafting is a complex surgical operation that should lead to pearl formation after approximately eighteen months. Although this technique has been used for many years in French Polynesia, the grafting process is still not standardised. While studies have been carried out in order to improve graft performance and yield, these remain highly variable due to post-grafting mortality, nucleus rejection and unreliable pearl quality, all of which constrain pearl farm profitability. The present study uses histological analysis to monitor oysters that either rejected or retained their nuclei. Both groups of oysters are compared in terms of evolution of the graft, which could influence retention, and the development of a pearl sac in cases where grafting...
Tipo: Text
Palavras-chave: Grafting process; Pearl formation; Pearl oyster; Pteriidae; Pinctada margaritifera.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00002/11288/7823.pdf

Mise en place d'un Réseau de Veille Zoosanitaire des huîtres perlières Pinctada margaritifera en Polynésie Française
Provedor de dados: 5
Autores: Cochennec-laureau, Nathalie; Levy, Peva; Saulnier, Denis; Fougerouse, Angelique.
L’importance socio-économique de l’activité perlière justifie que le Service de la Perliculture mette en place un réseau de surveillance pathologique de l’huître perlière Pinctada margaritifera en Polynésie française. Les objectifs de ce réseau sont de prévenir l’introduction ou l’apparition d’agents infectieux, de prévenir leur propagation à l’intérieur d’une zone d’élevage, d’étudier les moyens de limiter leur impact, de surveiller leur évolution et enfin de garantir les échanges entre les zones d’élevage. Cette première année a permis d’élaborer le schéma de fonctionnement du réseau et de vérifier sa faisabilité. Cinq zones de prélèvements ont été définies en fonction de critères d’accessibilité à la zone et de facilité d’acheminement des échantillons,...
Tipo: Text
Ano: 2003
URL: http://archimer.ifremer.fr/doc/00168/27886/26141.pdf

Biofouling development and its effect on growth and reproduction of the farmed pearl oyster Pinctada margaritifera
Provedor de dados: 5
Autores: 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

Maîtrise technique de la production de poissons lagonaires
Provedor de dados: 5
Autores: Remoissenet, Georges; Tamata, Thierry; Joufoques, Vaiana; Teissier, Alexandre; Tchepidjian, Benoît; Frogier, Teraiareva; Flohr, Stanley; Flores, David; Dagouret, Jean-marie; Le Marechal, Benoit; Darrasse, Sebastien; Tehahe, Ronald; Cochennec-laureau, Nathalie; Levy, Peva; Belliard, Corinne; Nedelec, Georges.
Ce rapport constitue l’aboutissement en fin d’année 2005 de la deuxième phase du Contrat de développement sur la maîtrise de l’élevage de poissons lagonaires, programme réalisé à l’Ifremer de Vairao en collaboration étroite entre l’Ifremer et la Polynésie française, et conduit par le service de la pêche (SPE) de Polynésie française. L’année 2005 a été consacrée essentiellement à la poursuite de nos travaux de mise au point technique de l’élevage du « Moi » et du « Paraha peue ». Dans ce cadre, rappelons qu’en début d’année 2005, un bilan de nos travaux ainsi qu’un recadrage des objectifs et des actions ont été réalisés lors d’une réunion technique de concertation à laquelle participait notamment Denis Coves, responsable des programmes piscicoles à...
Tipo: Text
Ano: 2006
URL: http://archimer.ifremer.fr/doc/00128/23885/21818.pdf