Consulta: subjectFacets:"Oyster"
Registros recuperados: 170
Data/hora: 01/06/2024 03:25:39

Энергетический баланс и чистая эффективность роста плоской устрицы (Ostrea edulis L.)
Provedor de dados: 13
Autores: Золотницкий, А. П.; Сытник, Н. А.
Исследованы энергетический баланс и чистая эффективность роста (коэффициент К2) плоской устрицы (Ostrea edulis L.) в онтогенезе. Выявлены общие тенденции изменений отдельных его компонентов в процессе роста и распределение энергетических трат на индивидуальную продукцию, энергетический обмен, ассимилированную и потреблённую пищу. Дана характеристика сезонных изменений чистой эффективности роста, связанных с температурой воды и массой тела, динамика которых описывается уравнением множественной регрессии. Показано, что максимальные значения К2 у исследованного вида могут составлять 0.63 – 0.67.
Tipo: Journal Contribution
Palavras-chave: Устрица; Энергетический баланс; Рост; Метаболизм; Ассимиляция; Рацион; Эффективность; Устриця; Енергетичний баланс; Зростання; Метаболізм; Асиміляція; Раціон; Ефективність; Oyster; Energy balance; Growth; Metabolism; Assimilation; Ration; Efficiency.
Ano: 2010
URL: http://repository.ibss.org.ua/dspace/handle/99011/1919

Open-air treatment of wastewater from land-based marine fish farms in extensive and intensive systems: current technology and future perspectives
Provedor de dados: 5
Autores: Hussenot, Jerome; Lefebvre, Sébastien; Brossard, Nicolas.
Marine land-based fish farms located in coastal wetlands (salt-pond zones, lagoon banks, etc.), whether extensive or intensive, send farm effluents directly to the sea or after short periods of stocking in retention reservoirs. The aims of our investigation have been to compare the efficiency of current and potential water treatment procedures in open-air. Wastewater retention ponds in commercial farms (Atlantic coasts of France) are efficient in removing up to 1 metric ton of particulate material (dry weight) per hectare and per day (faeces and unconsumed feed), but are inefficient in reducing dissolved wastes, both organic (urea, amino acids, protein) and inorganic (total ammonia nitrogen, phosphates). Forthcoming outdoor technology to treat these forms...
Tipo: Text
Palavras-chave: Traitement de l'eau; Effluent; Décantation; Sédimentation; Écumage; Microalgue; Huître; Water treatment; Effluent; Aquaculture; Sedimentation; Foam fractionation; Microalgae; Oyster.
Ano: 1998
URL: https://archimer.ifremer.fr/doc/1998/publication-873.pdf

Use of an ecosystem model for the assessment of the influence of cultivated oysters (Crassostrea gigas) on the nitrogen cycling in the Marennes-Oleron Bay
Provedor de dados: 5
Autores: Bacher, Cedric.
A model of the growth of cultivated oyster in the Marennes-Oléron bay was developped to assess the influence of the nutrients input and of the amount of oysters on the growth performance (Railiard. 1991). The ecosystem main characteristics are: - short residence time of the water. - high turbidity level, depending on the season, tidal level, bathymetry, currents and wind. The turbidity acts on the primary production through light limitation and on oyster production as a food dilution factor. - presence of high density cultivated areas on mid-tidal flats. The amount of oysters is ranging between 80 000 and 110 000 tons according to the year. - spatial variability of the biological and physical features. - coupling effects of the physic process (transport,...
Tipo: Text
Palavras-chave: Ecosystem model; Oyster; Crassostrea gigas; Nitrogen cycling; Marennes Oleron Bay; Charente Maritime.
Ano: 1993
URL: http://archimer.ifremer.fr/doc/00102/21300/18914.pdf

Rapid and sensitive detection of ostreid Herpesvirus 1 in oyster samples by real-time PCR (Poster)
Provedor de dados: 5
Autores: Pepin, Jean-francois; Riou, Antoine; Renault, Tristan.
Herpes and herpes-like virus infections have been reported in various marine mollusc species associated with high mortality rates. Following the characterisation and genome sequencing of ostreid herpesvirus 1 (OsHV-1), specific diagnostic tools have been developed based on conventional PCR techniques or in situ hybridisation. We have now developed a real-time PCR assay for rapid, sensitive and quantitative detection of OsHV-1, and compared it with a conventional PCR technique described previously. The new assay utilised SYBR® Green chemistry with specific primers C9/C10 targeting the C region, which is present in two copies in the OsHV-1 genome and encodes two proteins of unknown function. The assay was applied successfully to rapid diagnosis (100 minutes)...
Tipo: Text
Palavras-chave: Crassostrea gigas; PCR; Oyster; OsHV 1; Detection; Herpes virus 1.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3653.pdf

Feeding of Crassostrea gigas at high seston load : modeling requirements
Provedor de dados: 5
Autores: Barille, Laurent; Prou, Jean.
Ecophysiological experiments conducted in situ in the Bay of Marennes-Oléron during a spring and neap tide cycle in May 1991 , were designed to get a better representation of 2 important components of the energy budget of the Japanese oyster Crassostrea gigas : clearance rate and selection efficiency. The relationships previously established by Raillard et al. ( 1993) are re-evaluated by integrating the effects of high seston loads, typical of tidal effect within estuaries, on the physiological processes. For the clearance rate, the re-evaluated parameterization includes: - a negative effect of turbidity. - a clogging threshold set to 192 mg/l. Selection efficiency parameterizations are modified by incorporating : - a constant inorganic ingestion for...
Tipo: Text
Palavras-chave: Matematical model; Oyster; Crassostrea gigas; Clearance rate; Seclection efficency; Marennes Oleron; Charente Maritime.
Ano: 1993
URL: http://archimer.ifremer.fr/doc/00102/21299/18913.pdf

Gonad volume assessment in the oyster Crassostrea gigas: Comparison between a histological method and a Magnetic Resonance Imaging (MRI) method
Provedor de dados: 5
Autores: Flahauw, Emilie; Quellec, Stephane; Davenel, Armel; Degremont, Lionel; Lapegue, Sylvie; Hatt, Philippe-jacques.
Previous studies comparing Crassostrea gigas selected lines with different susceptibility to summer mortality concluded that the higher the reproductive effort the lower the survival. But theywere lacking individual followup of this reproductive effort which would be of great interest to help us to understand the physiology of the oysters facing summermortalities. Themost frequently usedmethod for assessing the volume of the gonad is to measure the area it occupies on histological sections. Gonad measurement by magnetic resonance imaging, in contrast, is non-destructive and therefore makes it possible to assess individual evolution as well as to compare individuals. The present study compared the values of gonad volume by thismethodwith the values of gonad...
Tipo: Text
Palavras-chave: Oyster; Crassostrea gigas; Reproduction; Histology; Magnetic resonance imaging; MRI.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00102/21309/19410.pdf

Performances de croissance de l'huître creuse, Crassostrea gigas (Thunberg) dans le bassin d'élevage de Marennes-Oléron entre 1979 &amp; 1982
Provedor de dados: 5
Autores: Berthome, Jean-paul; Prou, Jean; Bodoy, Alain.
Growth of the japanese oyster, Crassostrea gigas was monitored during 4 years, by following the recruitment of the year 1978, held in rearing conditions. After three and half years, the average length was la cm and the average total weight was 80 g. Clear seasonal changes were observed on the growth in length and weight.  An  important loss in dry weight occured in July, during the release of gametes. Such losses constituted 29 %, 43 % and 60 % of the dry weight, respectively for individuals which were 2 years, 3 years and 4 years old. The higher instantaneous growth rates  (G) were observed during spring and at the beginning of summer. Growth model of Von Bertalanffy, gave the best estimate for the length growth of the species. During the 1979-1982...
Tipo: Text
Palavras-chave: Growth parameter; Growth model; Reardd stock; Crassostrea gigas; Oyster; Growth; Descripteurs de croissance; Modèle de croissance; Stock cultivé; Crassostrea gigas; Huître; Croissance.
Ano: 1986
URL: http://archimer.ifremer.fr/doc/1986/publication-2967.pdf

Real-time PCR assay for rapid detection and quantification of Vibrio aestuarianus in oyster and seawater: A useful tool for epidemiologic studies
Provedor de dados: 5
Autores: Saulnier, Denis; De Decker, Sophie; Haffner, Philippe.
Because Vibrio aestuarianus is known to cause serious infections in Pacific oyster Crassostrea gigas, a real-time PCR assay was developed targeting the dnaJ gene of this bacterium. Only V. aestuarianus strains isolated from C. gigas mortality events in different geographic areas and the reference strain tested positive, whereas no amplification products was obtained with type strains belonging to 23 other species of Vibrio. Sensitivity and reproducibility of the method were assessed using either seawater or oyster homogenate samples spiked with one V aestuarianus strain. All these samples were stored at -20 degrees C in order to mimic retrospective or grouped natural sample analysis without quantification bias due to prolonged freezing. Analysis of...
Tipo: Text
Palavras-chave: V. aestuarianus; Vibrio; Taqman; Real time PCR; Pathogen; Oyster; Crassostrea gigas.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6447.pdf

Dynamique des sédiments fins et mixtes des zones intertidales de la baie de Marennes-Oléron
Provedor de dados: 5
Autores: Kervella, Stephane.
This thesis aims at increasing the general knowledge on sediment dynamics of intertidal flats in the Marennes-Oléron Bay, according to physical, biological and anthropogenic factors.  The conducted research is compound of three complementary studies: (1) a study of sediment behaviour through applied rheophysics on intertidal superficial sediments; (2) a hydro-sedimentary study based on identification of the forcing action (physical, biological or anthropogenic) on the intertidal flat stability over several time scales (from the event to several months); (3) a specific application of the model SiAM-2DH to the Marennes-Oléron Bay.  The surface sediments shows a mechanical behaviour that mainly depends on the fine fraction for a composition that contains up...
Tipo: Text
Palavras-chave: Rhéophysique; Seuil d’écoulement; Sédiments cohésifs et mixtes; Sédimentation; Érosion; Hydrodynamique; Vasière; Zone intertidale; Conchyliculture; ALTUS; SiAM-2DH; Baie de Marennes-Oléron; Rhéophysics; Shear strenght; Cohesive and mixed sediment; Sédimentation; Erosion; Hydrodynamics; Mudflat; Intertidal area; Oyster; ALTUS; SiAM-2DH; Marennes-Oléron Bay.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00004/11534/8117.pdf

Diagnosis of oyster herpes-like virus: development and validation of molecular, immunological and cellular tools "VINO" - First Periodic Progress Report 4th January 1999 to 3rd January 2000
Provedor de dados: 5
Autores: Renault, Tristan; Davison, Andrew; Xhonneux, Florence; Dorange, Germaine; Culloty, Sarah; Novoa, Beatriz; Dixon, Peter.
The aim of the programme is to develop specific tools for diagnosing herpes-like virus infections in bivalves and to validate these reagents by using them in different European laboratories involved in shellfish epidemiological surveys. This will done using techniques developed by the partners to characterise viruses by studying their genomes and immunologically reactive proteins, to cultivate oyster cells and vertebrate cell lines and to perform epidemiological surveys among bivalves. The programme objectives are: 1 - Obtaining the complete oyster herpes-like virus DNA sequence with determination of the genome structure. 2 - Comparing oyster herpes-like viruses with other viruses belonging to the Helpesviridae family on the basis of sequence data and...
Tipo: Text
Palavras-chave: Pathology; Diagnosis; Oyster; Herpes like virus; Herpesviridae; Immunology; Detection; Virus; Bivalves.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00044/15523/12910.pdf

Detection of multiple noroviruses associated with an international gastroenteritis outbreak linked to oyster consumption
Provedor de dados: 5
Autores: Le Guyader, Soizick; Bon, Fabienne; Demedici, Dario; Parnaudeau, Sylvain; Bertone, Alessandra; Crudeli, Silvia; Doyle, Aoife; Zidane, Mohamed; Suffredini, Elisabetta; Kohli E, Evelyne; Maddalo, Francesco; Monini, Marina; Gallay, Anne; Pommepuy, Monique; Pothier, Pierre; Ruggeri, Franco M.
An international outbreak linked to oyster consumption involving a group of over 200 people in Italy and 127 total subjects in 13 smaller clusters in France was analyzed using epidemiological and clinical data and shellfish samples. Environmental information from the oyster-producing area, located in a lagoon in southern France, was collected to investigate the possible events leading to the contamination. Virologic analyses were conducted by reverse transcription-PCR (RT-PCR) using the same primer sets for both clinical and environmental samples. After sequencing, the data were analyzed through the database operated by the scientific network FoodBorne Viruses in Europe. The existence of an international collaboration between laboratories was critical to...
Tipo: Text
Palavras-chave: Seafood; Contamination; Norovirus; Epidemiology; Virology; Oyster.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2096.pdf

Traditional oyster culture in France
Provedor de dados: 5
Autores: Heral, Maurice.
The indigenous oyster of mainland France, the fiat oyster, Ostrea edulis has been part of the human diet for centuries. The Romans collected them and exported them to Rome. Although tanks for holding oysters after harvesting were in use at that time (GreIon 1978) it seems that true culture was not developed along the coast contrary to the records of Pliny the Older. It appears that oysters were already being captured on hoards off the Italian coast. The exploitation of natural stocks continued through the Middle Ages and the Renaissance. However, it was not until the 17th century that oyster culture began, first in the pools of the salt marshes of the Atlantic coast and then in specially managed ponds. Papy (1941) repeats a good description given in 1688...
Tipo: Text
Palavras-chave: Rearing; Diseases; Analytical model; Overall model; Cultured stocks; Energetics; Reproduction; Nutrition; Physiology; France; Culture; Oyster.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/1989/publication-3039.pdf

Modulations of the interactions between pacific cupped oyster Crassostrea gigas and Vibrio according to bacterial virulence and to genetic and physiological status of the host : Methodology and first results
Provedor de dados: 5
Autores: De Decker, Sophie; Normand, Julien; Duperthuy, Marylise; Boudry, Pierre; Saulnier, Denis.
Rearing of Crassostrea gigas is the most economically important aquaculture activity in France. Bacteria belonging to Vibrio genus constitute one of the most abundant bacterial group in marine ecosystems. Two Vibrio species, V. splendidus and V. aestuarianus, were associated with many cases of mortality events in reared C. gigas spat and juvenile oysters, commonly during summer. This summer mortality syndrome has been extensively documented as the result of complex interactions between pathogens, host and environmental conditions. This work aims to study the Vibrio-host interactions and their modulations according to the virulence of pathogens and the genetic and/or physiological parameters of the host. These factors will be characterized by in vitro and...
Tipo: Text
Palavras-chave: Genetic; Pathogens; Interaction; Vibrio; Crassostrea gigas; Oyster.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3430.pdf

Cryopreservation of Crassostrea gigas vesicular cells: Viability and metabolic activity
Provedor de dados: 5
Autores: Hanquet, Anne-caroline; Kellner, K; Heude, C; Naimi, Amine; Mathieu, M; Poncet, J.m.
Cryopreservation is widely used for long-term conservation of various tissues, embryos or gametes. However, few studies have described cryopreservation of invertebrate primary cell cultures and more particularly of marine invertebrate somatic cells. This technique would however be of great interest to facilitate the study of various metabolic processes which vary seasonally. The aim of the present study was to develop a protocol for cryopreservation of Crassostrea gigas vesicular cells. Different parameters were adjusted to improve recovery of cells after freezing. The most efficient cryoprotectant agent was a mix of Me2SO, glycerol, and ethylene glycol (4% each). The optimal cooling rate was -1 degrees C min(-1) down to -70 degrees C before transfer into...
Tipo: Text
Palavras-chave: Glycogen metabolism; Vesicular cells; Cryopreservation; Mollusc; Oyster; Crassostrea gigas.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1938.pdf

Characterization of a gonad-specific transforming growth factor-beta superfamily member differentially expressed during the reproductive cycle of the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Fleury, Elodie; Fabioux, Caroline; Lelong, C; Favrel, P; Huvet, Arnaud.
Through differential screening between oyster families selected for high and low summer survival, we have characterized a new transforming growth factor-beta (TGF-beta) superfamily member. This novel factor, named oyster-gonadal-TGF beta-like (og-TGF beta-like), is synthesized as a 307 amino acid precursor and displays 6 of the 7 characteristic cysteine residues of the C-terminal, mature peptide. Sequence comparison revealed that og-TGF beta-like has a low percentage of identity with other known TGF-beta superfamily members, suggesting that og-TGF beta-like is a derived member of this large superfamily. Real-time PCR (RT-PCR) analysis in different oyster tissues showed that og-TGF beta-like is specifically expressed in both male and female gonads, at...
Tipo: Text
Palavras-chave: Reproduction; Oyster; Gene expression; Transforming growth factor; Bivalve mollusc.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-3899.pdf

Ingestion of a bacterivorous ciliate by the oyster Crassostrea gigas: Protozoa as a trophic link between picoplankton and benthic suspension-feeders
Provedor de dados: 5
Autores: Le Gall, Solange; Bel Hassen, Malika; Le Gall, Pierre.
The linked concepts of 'microbial loop' and 'protozoan trophic link' have been very well documented in filter-feeding microzooplankton such as copepods, but have not been applied to energy transfer to benthic suspension-feeding macrofauna, with the exception of the recent demonstration of heterotrophic flagellate assimilation by mussels. The oyster Crassostrea gigas obtains energy resources by filtering microalgae (similar to 5 to 100 mu m). However, in turbid estuaries, light-limited phytoplanktonic production cannot entirely account for oyster energy requirements. Conversely, picoplankters (&lt;2 mu m), which are main effecters of coastal energy flow and matter cycling, are not efficiently retained by oyster filtration. Ciliate protozoal as both...
Tipo: Text
Palavras-chave: Oyster; Food sources; Picoplankton; Protozoa; Trophic link.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00337/44788/44482.pdf

Etude comparative des caractéristiques écophysiologiques et des performances de croissance de l'huître creuse Crassostrea gigas diploïde et triploïde en milieu contrôlé
Provedor de dados: 5
Autores: Haure, Joel; Fortin, Adeline; Dupuy, Beatrice; Nourry, Max; Palvadeau, Hubert; Papin, Mathias; Penisson, Christian; Martin, Jean-louis.
Introduction: Marine farming in France is currently very widely dominated by oyster farming. French oyster production totals 148,467 tons, for a turnover of close to 280 million euros, making France the leading European producer. The two main species concerned are the cup oyster, Crassostrea gigas (140,000 tons) and the flat oyster, Ostrea edulis (2,000 tons), the production of which has collapsed since 1970 following successive epizootics of Marteilia refringens and Bonamia ostreae. French oyster farming is thus in a situation of quasi single-crop farming, with more than 90% of tonnage pertaining to the cup oyster (FAO data from 1993).  This situation of quasi single-crop farming leads to the pessimistic observation that one hypothetical crisis in the...
Tipo: Text
Palavras-chave: Growth; Ecophysiology; Oyster; Crassostrea Gigas; Eeproduction; Milieu Controle; Croissance; Triploide; Diploide; Ostreidae; Huitre; Crassostrea Gigas; Ecophysiologie; Reproduction.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/rapport-1509.pdf

Overwiew on selective breeding and genetic improvement in bivalve shellfish
Provedor de dados: 5
Autores: Boudry, Pierre.
Dr. Boudry focussed his talk on oysters, which are the most important bivalve species produced world wide (more than 4 million tons). One of the main characteristic of bivalve aquaculture is that most of the juveniles ("seed or "spat") are collected from natural recruitment (e.g. 100% of the European mussel production). Hatchery propagation is used in the case of introduced species (e.g. Crassostrea gigas in USA)  or limited natural recruitment.    The most significant genetic improvement for the production of Pacific oyster (C. gigas) to date has been obtained through the breeding of triploids, especially since the development of tetraploids. Triploidy lead to highly reduced gametogenesis and, as a result better growth and survival.  Many quantitative...
Tipo: Text
Palavras-chave: Crassostrea gigas; Oyster; Genetic variability; Bivalve shellfish; Selective breeding; Genetic.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/acte-3479.pdf

Effect of orgnotin compounds (TBT) used in antifouling paints on cultured marine molluscs - a literature study
Provedor de dados: 5
Autores: Heral, Maurice; Alzieu, Claude; Deslous-paoli, Jean-marc.
Organotin salts, used as antifouling substances have a deleterious effect on the environment particularly on molluscs and especially on the Japanese oyster Crassostrea gigas. A synthesis of the effects of tributyltin (TBT) on cultured molluscs reveals the following effects: 1) acute and chronic toxicity to the adults; 2) accumulation in the flesh 01 the adults; 3) perturbation 01 reproduction particularly fertility, mortality 01 offspring and decrease in larval growth rate; 4) decrease in the growth rate 01 juveniles and thickening 01 the shell; and 5) modification 01 the physiology al sublethal levels.
Tipo: Text
Palavras-chave: TBT; Crassostrea gigas; Oyster; Marine molluscs; Organotin.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/1989/publication-3016.pdf

Growth of the Pacific oyster (Crassostrea gigas) in a high-turbidity environment: Comparison of model simulations based on scope for growth and dynamic energy budgets
Provedor de dados: 5
Autores: 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 &gt; 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

Effect of sediment nearness on the metabolic enzyme activity and energy state of the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Le Moullac, Gilles; Fleury, Pierre-gildas; Le Coz, Jean-rene; Moal, Jeanne; Samain, Jean-francois.
This study was designed to assess in situ the effects of sediment nearness on Crassostrea gigas metabolism. One year-old oysters were reared for 5 months (April-August) in plastic bags on metallic frames at 10 and 60 cm off the sediment at the beginning of April. The management of the energetic resources (storage, consumption) was estimated with respect to biochemical changes of proteins, lipids and carbohydrates. In order to evaluate the  effect of the sediment nearness at cellular level, the metabolic rate was evaluated by assessing pyruvate kinase (PK) and phosphoenolpyruvate carboxykinase (PEPCK) enzyme activities and electron transport system (ETS) activity. The metabolic pathways were assessed by measuring ATP and intermediary metabolites such as...
Tipo: Text
Palavras-chave: Aspartate; Succinate; Alanine; ETS; PEPCK; PK; Carbohydrate; Lipids; Proteins; Sediment; Oyster; Aspartate; Succinate; Alanine; ETS; PEPCK; PK; Glucides; Lipides; Proteines; Sédiment; Huître.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2803.pdf

Noninvasive characterization of gonad maturation and determination of the sex of Pacific oysters by MRI
Provedor de dados: 5
Autores: Davenel, Armel; Quellec, Stéphane; Pouvreau, Stephane.
The aim of this study was to test the ability of magnetic resonance imaging (MRI) technique to characterize gonad development and to determine the sex of live Pacific oysters through their shells. A preliminary nuclear magnetic resonance (NMR) retaxometry study was conducted to characterize T-1 and T-2 NMR relaxation parameters for the main oyster organs. This showed that T-1-weighted MRI sequences were most appropriate to optimize contrasts between tissues in images. The results showed that gray levels of gonads in images acquired with gradient-echo sequence were variably affected by T-2* weighting effect. However, the ovaries systematically gave a hypersignal in spin-echo T-1-weighted images, and stack histograms of female oysters showed a peak well...
Tipo: Text
Palavras-chave: Spin echo; Gradient echo; Sex determination; Gonad maturation; Oyster.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1987.pdf

Comparative embryotoxicity and genotoxicity of the herbicide diuron and its metabolites in early life stages of Crassostrea gigas: implication of reactive oxygen species production
Provedor de dados: 5
Autores: Behrens, Daphne; Rouxel, Julien; Burgeot, Thierry; Akcha, Farida.
Herbicides are one of the major classes of pollutants contaminating coastal waters over the world. Among them, diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is a phenylurea herbicide frequently detected in oyster-producing area, known to be toxic for this important exploited non-target species. With the aim to investigate the mechanisms by which diuron displays its toxicity in oyster, the implication of both biotransformation and oxygen reactive species (ROS) production was studied considering embryotoxicity and genotoxicity as endpoints. Comparative embryotoxicity and genotoxicity of diuron and its main metabolites (DCPMU, DCPU and 3,4-DCA) were thus studied on oyster larvae by the embryo-larval bioassay on D larvae and the comet assay on trochophore...
Tipo: Text
Palavras-chave: Oyster; Herbicide; Embryotoxicity; Genotoxicity; Oxidative stress; Biotransformation.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00324/43521/43053.pdf

Norovirus contamination on French marketed oysters
Provedor de dados: 5
Autores: Schaeffer, Julien; Le Saux, Jean-claude; Lora, Monica; Atmar, Robert; Le Guyader, Soizick.
Contaminaded shellfish have been implicated in gastroenteritis outbreaks in different countries. As no regulation has been set up yet regarding viral contamination of food, very few data are available on the prevalence of contamined products on the market. This study presents data obtained from oysters collected on the French market in one producing area over a 16 month period of time. Noroviruses were detected in 9% of samples with a seasonal impact and influence of climatic events. Contamination levels were low and, surprisingly, oysters sampled directly from the producer were found to have less contamination than oystes from supermarkets.
Tipo: Text
Palavras-chave: Oyster; Marker; Norovirus; Quantification; Calicivirus; Prevalence.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00152/26367/24457.pdf

Cryopreservation of Pacific oyster ( Crassostrea gigas ) larvae: Revisiting the practical limitations and scaling up the procedure for application to hatchery
Provedor de dados: 5
Autores: Labbe, Catherine; Haffray, Pierrick; Mingant, Christian; Quittet, Benjamin; Diss, Blandine; Tervit, H. Robin; Adams, Serean L.; Rimond, Flore; Suquet, Marc.
Pacific oyster Crassostrea gigas is one major species for aquaculture, and the development of breeding programs and the need for preservation of wild stock genetic resources prompted the need for larvae cryopreservation. The objective of the present study was to choose the most reliable protocol from several existing publications, to test its biological and practical limitations, and to adapt it to hatchery conditions. The selected protocol was characterized by a very slow freezing rate without seeding, and by the use of ethylene glycol and sucrose as cryoprotectant. The best survivals after thawing and rearing up to 48 h post fertilization (hpf) were obtained with larvae that were frozen at late trochophore (20 hpf) and early-D (24 hpf) stages. Increasing...
Tipo: Text
Palavras-chave: Oyster; Cryobanking; D stage; Ethylene glycol; High throughput; Hatchery.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00423/53460/54354.pdf

Environment and immunomodulation : effects of the soluble fraction of Norwegian heavy fuel on the immune system of Pacifc oyster, Crassostrea gigas
Provedor de dados: 5
Autores: Bado-nilles, Anne; Auffret, Michel; Quentel, Claire; Le Floch, Stéphane; Arzel, Jacqueline; Gagnaire, Beatrice; Renault, Tristan; Thomas-guyon, Hélène.
Estuaries and coastal areas are often subjected to much pollution, including pesticides and polycyclic aromatic hydrocarbons (PAHs) produced by anthropic activities. Bay of Marennes-Oléron is an estuarine coastal zone in which there is a high level of aquacultural production and this has adverse effects in aquatic organisms. In fact, PAHs, which are widely spread throughout aquatic ecosystems, have a low polarity and so there is a clear tendency to bioaccumulate in marine organisms (1). The harmful effects of such contaminants on the organism's immune system, leading to a decreased resistance to pathogens, is a relatively new area of research and it still poorly understood. The aim of the present work was to detect the impact in vivo of PAHs on the immune...
Tipo: Text
Palavras-chave: PaHs; Contamination; Crassostrea gigas; Oyster.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/acte-3428.pdf

Improving detoxification Efficiency of PSP-contaminated oysters (Crassostrea gigas Thunberg)
Provedor de dados: 5
Autores: Lassus, Patrick; Bardouil, Michele; Baron, Regis; Berard, Jean-baptiste; Masselin, Pierre; Truquet, Philippe; Pitrat, Jp.
Shellfish production, and production of marine bivalve molluscs in particular, is the main form of marine aquaculture in the European Union, with a production estimated at 1,200,000 tons in 1999 (Food and Agricultural Organization). Moreover, aquaculture production is rapidly expanding throughout Europe and is becoming a major economic resource in developing areas such as Northern Greece, Ireland, and northwestern Spain. These shellfish, mainly mussels, oysters, and clams, are produced in a natural environment. Due to variations in their environment, these otherwise edible species may however become unsafe for human consumption. Potential problems are amplified due to the nature of shellfish themselves: as they are filter feeders, they consume large...
Tipo: Text
Palavras-chave: Detoxification; PSP toxin; Toxic algae; Bioaccumulation; Contaminant; Clam; Mussel; Oyster; Shellfish culture.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-2271.pdf

Conséquences génétiques de la production intensive de larves d'huîtres en écloserie : étude des processus de dérive et de sélection liés aux pratiques d'élevage.
Provedor de dados: 5
Autores: Taris, Nicolas.
In order to study the genetic influence of intensive production of the larval stage in commercial hatcheries, two types of specific selective processes were examined: the effects of discarding the smallest larvae and temperature. A mixed-family approach was used in order to infer the genetic composition of the larvae.  The results show that our mixed-family approach, combined with microsatellite-based family assignment, is a powerful tool for the study of bivalve larvae genetics. Selective sieving is an advantageous practice at a phenotypic scale, but also represents a substantial risk for diversity loss. The culled larvae are important for the minimization of the variability in reproductive success and the maximization of broodstock genetic diversity....
Tipo: Text
Palavras-chave: Hatchery; Oyster; Genetic diversity; Selection domestication; Larvae; Crassostrea gigas; Ecloserie; Huître; Diversité génétique; Sélection domestication; Larve; Crassostrea gigas.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/these-976.pdf

Study of interactions between flat oyster, Ostrea edulis, and the parasite Bonamia ostreae using flow cytometry and suppression subtractrive hybridization (SSH)
Provedor de dados: 5
Autores: Morga, Benjamin; Arzul, Isabelle; Faury, Nicole; Gagnaire, Beatrice; Chollet, Bruno; Renault, Tristan.
Bonamiosis due to the intrahaemocytic protistan parasite Bonamia ostreae is a European endemic disease affecting flat oysters Ostrea edulis. Control of bonamiosis requires a good knowledge of the parasite life cycle including host-parasite interactions. In this study, we investigated interactions between parasites and haemocytes by flow cytometry and Suppression Subtractive Hybridization (SSH). In both approaches, analyses were performed after 2 hours of contact between haemocytes and parasites purified from highly infected flat oysters. Flow cytometry analyses consisted in testing haemocyte activities including esterase activities, reactive oxygen species (ROS) production and phagocytosis after contact with live parasites and parasites inactivated by...
Tipo: Text
Palavras-chave: SSH; Suppression subtractive hybridization; Cytometry; Bonamia ostreae; Parasite; Ostrea edulis; Oyster.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3367.pdf

Report of the workshop on shellfish bivalve cultivation, growth, modelling and impact on the ecosystem
Provedor de dados: 5
Autores: Heral, Maurice; Bayne, B.
The Workshop was held in Plymouth (6-10 October 1996) in the Royal Plymouth Corinthian Yacht club organised by the Plymouth Marine Laboratory under the joint charmanships of B. Bayne et M. Héral. 36 scientists were participated to this meeting from 11 countries, 8 belonging to ICES (Annex 1) 30 communications have been presented. This meeting was supported by an European Union contrat from DG14 with a concerted action AIR3 CT 942219 on Trophic capacity of coastal zone of oysters, mussels and cockles cultivation. This contract has paid the travel cost of all the participants.
Tipo: Text
Palavras-chave: Coastal systems; Carrying capacity; Physiological results; Oyster; Shefflish bivalve.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/1996/acte-7350.pdf

In vitro culture of mollusc hemocytes. Functional study of burst respiratory activity and analysis of interactions with protozoan and procaryotic pathogens
Provedor de dados: 5
Autores: Boulo, Viviane; Hervio, Dominique; Morvan, Annie; Bachere, Evelyne; Mialhe, Eric.
The chief importance of hemocytes as immune effectors in molluscs has led to develop researches for in vitro culture. The chemiluminescence technique has been used to estimate the phagocytosis capacity of Crassostrea gigas hemocytes according to different culture media and times. Sea water was used as a basic medium. Additives, such as antibiotics or glucose and buffers, such as Tris or Hepes, were tested as weIl as artificial sea water. Hemocyte chemiluminescence activities were recorded at t=o in relation to the medium composition. The highest values were observed when hemocytes were kept in sea water without any modification. Whichever medium, chemiluminescence activity was substantially decreased when hemocytes were previously kept in vitro for a few...
Tipo: Text
Palavras-chave: Crassotrea gigas; Oyster; Bonamia ostreae; Pathogens; Molluscs; Hemocytes.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/acte-4115.PDF

Transcriptional changes in Crassostrea gigas oyster spat following a parental exposure to the herbicide diuron
Provedor de dados: 5
Autores: Rondon, R.; Akcha, Farida; Alonso, P.; Menard, Dominique; Rouxel, Julien; Montagnani, Caroline; Mitta, Guillaume; Cosseau, C.; Grunau, C.
The Pacific oyster Crassostrea gigas is the main oyster species produced in the world, and a key coastal economic resource in France. High mortalities affect Pacific oysters since 2008 in France and Europe. Their origins have been attributed to a combination of biotic and abiotic factors, underlining the importance of environment quality. The impact of water pollution has been pointed out and one of the pollutants, the genotoxic herbicide diuron, occurs at high concentrations all along the French coasts. Previous work has revealed that a parental exposure to diuron had a strong impact on hatching rates and offspring development even if spats were not exposed to diuron themselves. In this study, we explored for the first time the transcriptional changes...
Tipo: Text
Palavras-chave: Mollusk; Oyster; Diuron; Transcriptomic; Ecotoxicology.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00318/42938/42438.pdf

Autotetraploid Pacific oysters (Crassostrea gigas) obtained using normal diploid eggs: induction and impact on cytogenetic stability
Provedor de dados: 5
Autores: Benabdelmouna, Abdellah; Ledu, Christophe.
We describe two methods of producing viable and fertile autotetraploid Pacific oyster (Crassostrea gigas Thunberg) based on the use of normal-sized oocytes produced by normal diploid females. Our methods showed that the oocyte size is not a limiting factor for the success of the induction to autotetraploidy. These methods offer means of direct introgression of genetic progress from elite diploid lines to tetraploids used as broodstock, avoiding a triploid step with the risk of transferring undesirable traits from highly fecund triploids. High variability in the level of cytogenetic stability was found among the different tetraploid oysters tested showing that induction method has an important impact on the long-term cytogenetic stability of the...
Tipo: Text
Palavras-chave: Oyster; Tetraploid induction; Mosaicism; Aneuploidy; Cytogenetic stability.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00278/38924/37464.pdf

First evidence of the activation of Cg-timp, an immune response component of pacific oysters, through a damage-associated molecular pattern pathway
Provedor de dados: 5
Autores: Montagnani, Caroline; Avarre, Jean-christophe; De Lorgeril, Julien; Quiquand, M; Boulo, Viviane; Escoubas, Jean-michel.
In a previous work, we characterized a Crassostrea gigas cPNA (Cg-timp) encoding a protein which presents all the features of vertebrate tissue inhibitor of metalloproteinase (TIMP). The expression pattern of this gene led us to propose that Cg-timp is an important factor in oyster wound heating and defense mechanisms. Here we describe the analysis of Cg-timp expression in oysters challenged by live or dead bacteria as well as by bacterial secretory/excretory products and metalloproteinase. Surprisingly, bacterial secretory/excretory products activate Cg-timp gene expression whereas heat-inactivated ones do not. To address the question of the signal transduction pathway involved in Cg-timp gene activation, we isolated and sequenced Cg-timp promoter and...
Tipo: Text
Palavras-chave: Damage associated molecular pattern; Tissue inhibitor of metalloproteinase; Metalloproteinase; Mollusk immunity; Crassostrea gigas; Oyster.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2094.pdf

Nanoplastics impaired oyster free living stages, gametes and embryos
Provedor de dados: 5
Autores: Tallec, Kevin; Huvet, Arnaud; Di Poi, Carole; Gonzalez-fernandez, Carmen; Lambert, Christophe; Petton, Bruno; Le Goic, Nelly; Berchel, Mathieu; Soudant, Philippe; Paul-pont, Ika.
In the marine environment, most bivalve species base their reproduction on external fertilization. Hence, gametes and young stages face many threats, including exposure to plastic wastes which represent more than 80% of the debris in the oceans. Recently, evidence has been produced on the presence of nanoplastics in oceans, thus motivating new studies of their impacts on marine life. Because no information is available about their environmental concentrations, we performed dose-response exposure experiments with polystyrene particles to assess the extent of micro/nanoplastic toxicity. Effects of polystyrene with different sizes and functionalization (plain 2-μm, 500-nm and 50-nm; COOH-50 nm and NH2-50 nm) were assessed on three key reproductive steps...
Tipo: Text
Palavras-chave: Oyster; Embryos; Gametes; Microplastics; Nanoplastics.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00453/56419/58090.pdf

Farmed bivalve loss due to seabream predation in the French Mediterranean Prevost Lagoon
Provedor de dados: 5
Autores: Richard, Marion; Forget, Fabien; Mignucci, Alexandre; Mortreux, Serge; Le Gall, Patrik; Callier, Myriam; Weise, Am; Mckindsey, Cw; Bourjea, Jerome.
Bivalve predation by seabream has been observed worldwide and is a major concern for bivalve farmers. Farmed bivalve-seabream interactions must be better understood to ensure the sustainability of bivalve aquaculture. The objectives of this study were to characterize gilthead seabream Sparus aurata presence in a bivalve farm in Prevost Lagoon (Mediterranean Sea) using acoustic telemetry and to evaluate monthly losses of mussels Mytilus galloprovincialis and oysters Crassostrea gigas due to seabream predation over an 18 mo period inside the farm and at an unprotected experimental platform. Large (281 to 499 mm TL) seabream were more commonly detected in the bivalve farm than were small (200 to 280 mm TL) seabream. In contrast to small seabream, 90% of large...
Tipo: Text
Palavras-chave: Shellfish culture; Sparus aurata; Size; Acoustic telemetry; Crassostrea gigas; Mytilus galloprovincialis; Oyster; Mussel.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00663/77515/79299.pdf

Anaesthesia and gonad sampling in the European flat oyster (Ostrea edulis)
Provedor de dados: 5
Autores: Suquet, Marc; Gonzalez, Ricardo; Lebrun, Luc; Queau, Isabelle; Mingant, Christian; Robert, Rene.
Controlled reproduction of the European flat oyster requires the development of tools adapted to this species, including a practical anaesthesia and gonad sampling protocol to facilitate sex determination and the verification of gametogenesis. Three replicate groups of 10 oysters (mean weight +/- SD: 29.9 +/- 8.5 g) were anaesthetised in 5 L containers using magnesium chloride designed either for laboratory (Flucka (R)) or agricultural (Dead Sea Work (R): DSW) use, at two concentrations (50 or 72 g L-1). No significant differences were observed in the percentages of oysters anaesthetised or subsequent oyster mortality with the different anaesthetics or concentrations, but increasing water temperature from 14.9 to 18.8 degrees C significantly increased the...
Tipo: Text
Palavras-chave: Oyster; Ostrea edulis; Anaesthesia; Magnesium chloride; Gonad sampling.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00018/12907/9876.pdf

Oysters as sentinels of climate variability and climate change in coastal ecosystems
Provedor de dados: 5
Autores: Thomas, Yoann; Cassou, Christophe; Gernez, Pierre; Pouvreau, Stephane.
Beyond key ecological services, marine resources are crucial for human food security and socio-economical sustainability. Among them, shellfish aquaculture and fishing are of primary importance but become more vulnerable under anthropogenic pressure, as evidenced by reported mass mortality events linked to global changes such as ocean warming and acidification, chemical contamination, and diseases. Understanding climate-related risks is a vital objective for conservation strategies, ecosystems management and human health. We provide here a comprehensive study of the historical mortality of adult oysters related to observed climate variability along the French Atlantic coast from 1986 to 2015, and we built on this knowledge to develop hindcast and forecast...
Tipo: Text
Palavras-chave: North Atlantic; Weather regime; Oyster; Monitoring network; Mortality risk assessment; Climate models; RCP scenarios.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00461/57255/59281.pdf

Summer mortality of selected juvenile pacific oyster Crassostrea gigas under laboratory conditions and in comparison with field performance
Provedor de dados: 5
Autores: Degremont, Lionel; Soletchnik, Patrick; Boudry, Pierre.
This study reports mortality under laboratory conditions in unselected controls and two lines of juvenile Pacific oysters Crassostrea gigas, previously selected for their high or low survival in the field during the summer period. Oysters were also deployed in field conditions and mortality between both conditions was then compared. In the laboratory, mortality was observed in all experiments and it always lasted for a week indicating that mortality under laboratory conditions was a short-term event. It was also shown that mortality could be repeated for a batch in several experiments using oysters which never experienced any abnormal mortality. This approach could facilitate further studies to investigate the causes of mortality by allowing repeated...
Tipo: Text
Palavras-chave: Summer mortality; Crassostrea gigas; Laboratory; Field; Oyster; Juvenile.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00013/12432/9228.pdf

Development of a new diagnostic tool (Mini-Array) for ostreid Herpesvrus 1 (OsHV-1) detection in the Pacific oyster Crassostre gigas
Provedor de dados: 5
Autores: Varsamos, S.; Pepin, Jean-francois; Sauvage, Christopher; Renault, Tristan.
OsHV-1 was the first herpesvirus to be identified in an invertebrate host and is associated to mortalities in the Pacific oyster (Crassostrea gigas) and other economically important bivalve species. Infections due to OsHV-1 are frequently reported and cause high mortality rates in larvae and spat of C. gigas. Detection of this pathogen is usually performed by PCR and/or in situ hybridization. This presentation will focus on the development of a new molecular diagnostic tool for OsHV-1 (and OsHV-1 variant 1) detection: the mini-array. This detection system, which allows multiple pathogens detection, combines viral DNA amplification by PCR and a specific hybridisation on a nylon membrane, revealed by a colorimetric reaction (DNA chip). Multiplex PCR involves...
Tipo: Text
Palavras-chave: Diagnostic; Crassotrea gigas; Oyster; Detection; Herpesviridae; OsHV 1.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3652.pdf

Project ROMEO : E. C. n° FA-S2 9052 - Research objectives : Mortality in European Oysters - Final Report
Provedor de dados: 5
Autores: Renault, Tristan; Arzul, Isabelle.
Crassostrea gigas is increasingly being cultured in a great number of countries from animaIs originally introduced from Japan, and is one of the most exploited bivalve species in the EU (FAO, 1989). Although no serious pathogen was detected previously in Japanese oysters in Europe, mortalities have been observed since the introduction of this bivalve species into the EU. Thus, oyster cultivation may be endangered by the occurrence of epizootics, especially virus diseases, which are considered one of the maj or risks to production. Indeed, mortalities have been described among different species of ostreids and are associated with the presence of viruses belonging to various families. The first description of a virus was reported in adult Eastern oyters,...
Tipo: Text
Palavras-chave: Pathology; Virology; Herpes-like infection; Detection; Diagnosis; Herpesviridae; Oyster; Crassostrea gigas; Mortality.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00044/15536/12915.pdf

Cytotoxic and antibacterial properties of Mytilus galloprovincialis, Ostrea edulis and Crassostrea gigas (bivalve molluscs) hemolymph
Provedor de dados: 5
Autores: Hubert, Florence; Van Der Knaap, Wil; Noel, Thierry; Roch, Philippe.
Mussel (Mytilus galloprovincialis) plasma contains cytotoxic activity against both vertebrate (erythrocytes and mouse tumour) and protozoan cells. Procaryotes (Escherichia coli and Vibrio alginolyticus) were not sensitive to the cytotoxicity. The activity was still present in dialyzed samples but was inhibited by heating at 45°C. Large individual variability which was not correlated with protein concentration and an increasing number of reactive specimens following injection, suggested that naive mussels were in various stages of immune response. Purification by anion exchange chromatography followed by gel filtration revealed a 320 kDa cytotoxic polymeric protein that acts through a polymerization process after binding onto target cell membranes as...
Tipo: Text
Palavras-chave: Cytotoxicité; Antibactérien; Hémolymphe; Lysat d'hémocyte; Moule; Huître; Mytilus galloprovincialis; Ostrea edulis; Crassostrea gigas; Cytotoxicity; Antibacterial; Hemolymph; Hemocyte lysate; Musssel; Oyster; Mytilus galloprovincialis; Ostrea edulis; Crassostrea gigas.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/00039/15008/12333.pdf

Effects of an environmentally relevant concentration of diuron on oyster genitors during gametogenesis: responses of early molecular and cellular markers and physiological impacts
Provedor de dados: 5
Autores: Akcha, Farida; Barranger, Audrey; Bachere, Evelyne; Berthelin, C. Heude; Piquemal, D.; Alonso, P.; Sallan, R. Rondon; Dimastrogiovanni, G.; Porte, C.; Menard, Dominique; Szczybelski, A.; Benabdelmouna, Abdellah; Auffret, M.; Rouxel, Julien; Burgeot, Thierry.
Genitors of the Pacific oyster Crassostrea gigas were submitted during gametogenesis to a short pulse exposure to the herbicide diuron at a realistic environmental concentration. Histological analysis showed no effect of diuron on gametogenesis course, sex ratio and reproductive effort. A non-significant increase in testosterone and progesterone levels was observed in genitors exposed to the herbicide. At cell level, diuron exposure was shown to modulate the phagocytic activity of circulating hemocytes. The results of a transcriptional analysis showed that diuron affected the expression of genes belonging to functions known to play a major role during oyster gametogenesis such as gene transcription regulation, DNA replication and repair, DNA methylation...
Tipo: Text
Palavras-chave: Oyster; Pesticide; Reproduction; Histology; Gene expression; RT-qPCR; Steroid; Immunity.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00309/41983/83232.pdf

Programme qualité des huîtres creuses Crassostrea gigas : 1ère année (1995)
Provedor de dados: 5
Autores: Baud, Jean-pierre; Goyard, Emmanuel.
Variability of oyster quality at marketable size in winter was assesed by using a proportional sampling strategy based upon the yearly production of the oyster packing house. Landings per unit of production were estimated using the number of commercialized sanitary certification labels or/and the annual landings declared to the Veterinary Services. The range of variability for 15 parameters was estimated using the national monitoring network (REMORA) data outputs and a regional questionnaire. Both data sources showed similar results. Condition indices and morphological factors led to the highest variability. However, these conclusions should be confirmed by additional studies considering seasonal trends to assess the described quantitative relationships.
Tipo: Text
Palavras-chave: Programme qualité; Huître creuses; Crassostrea gigas; Quality monitoring network; Oyster; Crasssotrea gigas.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00047/15871/13290.pdf

Magnetic resonance imaging as a means to assess the body growth and the gonad development of the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Hatt, Philippe-jacques; Davenel, Armel; Eliat, Pierre-antoine; Quellec, Stephane.
To make a preliminary exploration of the possibilities and limits of magnetic resonance imaging (MRI) for assessing body growth and gonad development of the Pacific oyster, Crassostrea gigas, individual monitoring was conducted on diploid and triploid oysters in their second year, maintained from February to October in a pond on the French Atlantic coast. Magnetic resonance imaging was done on each oyster on five dates during the study period. From these images, variations in the volumes of the flesh, digestive gland-gonad and adductor muscle, and the surface of the gills were measured over time. Apart from the well known differences between diploids and triploids related to maturation of gametes, other original observations of assessing growth were made...
Tipo: Text
Palavras-chave: Crassostrea gigas; Oyster; Gonad development; Growth; Magnetic resonance imaging; MRI.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6872.pdf

Feeding rate of the oyster Crassostrea gigas in a natural planktonic community of the Mediterranean Thau Lagoon
Provedor de dados: 5
Autores: Dupuy, Christine; Vaquer, André; Lam Hoai, Thong; Rougier, Claude; Mazouni, Nabila; Lautier, Jacques; Collos, Yves; Le Gall, Solange.
The Mediterranean Thau Lagoon is an important oyster farming area in Europe. Oyster growth rates are among the highest in France, although chlorophyll a concentration is low. Previous studies have demonstrated that picophytoplankton, nano-microphytoplankton, dinoflagellates and loricate ciliates such as tintinnids are abundant. However, heterotrophic flagellates and aloricate ciliates have not been investigated. The aim of this study was to assess picophytoplankton, protist and zooplankton abundances in the Lagoon and to investigate the particular structure of the microbial food web, which may explain such paradoxical oyster growth. In oligotrophic waters in the Thau Lagoon, the picoeukaryote Ostreococcus tauri is the dominant autotrophic picoplankter,...
Tipo: Text
Palavras-chave: Trophic link; Picophytoplankton; Heterotrophic protist; Microbial food web; Thau Lagoon; Food source; Oyster; Bivalve.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-812.pdf

Spatio-temporal changes in mortality, growth and condition of the pacific oyster, Crassostrea gigas, in Normandy (France)
Provedor de dados: 5
Autores: Royer, J; Ropert, Michel; Costil, K.
Summer mortalities have been observed in French shellfish areas (including Normandy) since 1994, but origin of this syndrome remains unclear and is suspected to be caused by a combination of several interacting extrinsic (biotic and abiotic) and intrinsic (genetic, physiological, immunological) factors. The French research program, MOREST aimed to identify the origin of oyster summer mortality along the French coast, focusing on the interactions between oysters, their pathogens, and the environment. The present study analyzed spatio-temporal variation in growth, condition and mortality in spat, and half-grown and market-sized oysters reared from February 2000 to October 2003 at six stations within two different areas in the Bay of Veys, Normandy: Grandcamp...
Tipo: Text
Palavras-chave: France English Channel; Growth; Summer mortality; Crassostrea gigas; Oyster.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-4733.pdf

Bonamia ostreae and Ostrea edulis : a stable host-parasite system in France?
Provedor de dados: 5
Autores: Arzul, Isabelle; Miossec, Laurence; Blanchet, Estelle; Garcia, Celine; Francois, Cyrille; Joly, Jean-pierre.
Bonamiosis due to the intrahaemocytic protistan parasite Bonamia ostreae is a European endemic disease affecting flat oysters Ostrea edulis. After its first description in June 1979 in L'Ile Tudy, Brittany, the parasite rapidly spread to all French oyster farming areas and in other European countries through transfers of live molluscs. Bonamiosis and marteiliosis, another protozoan disease appeared in the seventies, drastically reduced the French flat oyster production from 20 000 tonnes in 1970 to less than 2000 tonnes after 1981. In 2001, about 1650 t of flat oysters were marketed in France. The production is restricted to several areas specialised in reproduction, growth and/or marketing, and depends on transfers of animals. Most important production...
Tipo: Text
Palavras-chave: Bonamia ostreae; Parasitology; Pathology; Ostrea edulis; Oyster.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/acte-6381.pdf

Long-term records of cadmium and silver contamination in sediments and oysters from the Gironde fluvial-estuarine continuum - Evidence of changing silver sources
Provedor de dados: 5
Autores: Lanceleur, Laurent; Schaefer, Joerg; Chiffoleau, Jean-francois; Blanc, Gerard; Auger, Dominique; Renault, Sophie; Baudrimont, Magalie; Audry, Stephane.
The Gironde fluvial estuarine system is impacted by historic metal pollution (e.g. Cd, Zn, Hg) and oysters (Crassostrea gigas) from the estuary mouth have shown extremely high Cd concentrations for decades. Based on recent work (Chiffoleau et al., 2005) revealing anomalously high Ag concentrations (up to 65 mg kg(-1); dry weight) in Gironde oysters, we compared long-term (similar to 1955-2001) records of Ag and Cd concentrations in reservoir sediment with the respective concentrations in oysters collected between 1979 and 2010 to identify the origin and historical trend of the recently discovered Ag anomaly. Sediment cores from two reservoirs upstream and downstream from the main metal pollution source provided information on (i) geochemical background...
Tipo: Text
Palavras-chave: Silver; Cadmium; Estuary; Oyster; Biomonitoring.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00060/17109/15071.pdf

Variance of reproductive success in the European flat oyster Ostrea edulis assessed by microsatellite-based parentage analyses in a natural population and in hatchery
Provedor de dados: 5
Autores: Lallias, Delphine; Taris, Nicolas; Boudry, Pierre; Bonhomme, Francois; Lapegue, Sylvie.
he European flat oyster (Ostrea edulis L.) is a marine bivalve whose natural geographical distribution ranges along the European Atlantic coast from Norway to Morocco, in addition to the Mediterranean and Black Sea. Previous studies of allozymes, microsat-ellites and mitochondrial differentiation over the whole range concluded that a significant divergence existed between Mediterranean and Atlantic populations, together with an isolation-by-distance pattern. However, the average mitochondrial haplotypic diversity displayed a high among populations variance, reflecting smaller effective population size in some locations. Additionally, a ten-fold quantitative difference was observed in the same study in Fst between the mitochondrial and the nuclear genomes,...
Tipo: Text
Palavras-chave: Genotypes; Genetic diversity; Breeding success; Allozymes; Population genetics; Parentage analyses; Natural population; Ostrea edulis; Oyster.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/acte-3334.pdf

Fluctuating asymmetry and mortality in cultured oysters (Crassostrea gigas) in Marennes-Oleron basin
Provedor de dados: 5
Autores: Frechette, Marcel; Goulletquer, Philippe; Daigle, Gaétan.
Japanese cupped oysters suffer summer mortality in many culture sites along the French Atlantic coast. To ascertain whether mortality might be associated with morphological features of the shells, we estimated fluctuating asymmetry (FA) of hatchery/nursery-produced oysters kept in culture bags in the intertidal. FA is defined as random variations from a perfect symmetry plane (bilateral or radial) in some morphological trait. FA increases with disruption of homeostasy during ontogeny and has both genetic and environmental determinants. We found significant differences in FA between dead and live oysters in two of our three study groups. Therefore, lack of developmental stability may be involved in the summer mortality syndrome of oysters. We also found...
Tipo: Text
Palavras-chave: Oyster; Mortality; Fluctuating asymmetry; Aquaculture.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/publication-575.pdf

Effects of temperature and salinity on the survival of Bonamia ostreae parasite infecting falt oyster Ostrea edulis in sea water
Provedor de dados: 5
Autores: Arzul, Isabelle; Bond, Celine; Gagnaire, Beatrice; Chollet, Bruno; Morga, Benjamin; Ferrand, Sylvie; Robert, Maeva; Renault, Tristan.
Bonamiosis due to the intrahaemocytic protistan parasite Bonamia ostreae is a European endemic disease affecting flat oysters Ostrea edulis. The parasite has been described in different ecosystems from estuaries to open sea and no clear correlations could be demonstrated between the development of the disease and environmental parameters such as temperature or salinity. The parasite life cycle, including its survival outside the host is not completely known. Nevertheless, the infection can be directly transmitted by cohabitation between infected and non infected oysters suggesting that the parasite does not need intermediate host to complete its cycle. In the present study, the impact of temperature and salinity on the survival of purified parasites...
Tipo: Text
Palavras-chave: Effects; Temperarature; Salinity; Bonamia ostreae; Parasite; Pathology; Flat oyster; Ostrea edulis; Oyster.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3375.pdf

Croissance, engraissement et mortalité de l'huître creuse Crassostrea gigas en baie de Bourgneuf  : comparaison de quatre secteurs ostréicoles
Provedor de dados: 5
Autores: Haure, Joel; Baud, Jean-pierre.
A study on mortalities, growth and fattening of the oyster Crassostrea gigas was carried out spring with the autumn 1987 in four sites of bay of Bourgneuf. Mortalities, more important in spring, prove to be higher in the sectors North compared to the Southern sectors of bay of Bourgneuf.  The performances of growth are rather weak when they are compared with other French oyster sectors. They however present a better production in the cattle-breeding areas located at the South of bay. The spring phase is marked by the formation of glucidic reserves, at the moment of the reheating of water, which is quickly transformed, in the majority of the sites, in lipids of reserves of the ovocytes, during the gamétogenèse.   The state of fattening of Crassostrea gigas...
Tipo: Text
Palavras-chave: Fattening; Oyster; Mortality; Growth; Bay of Bourgneuf; Crassostrea gigas; Engraissement; Huitre; Mortalité; Croissance; Baie de Bourgneuf; Crassostrea gigas.
Ano: 1990
URL: http://archimer.ifremer.fr/doc/1990/rapport-1646.pdf

Evidence of differential chromosome loss in aneuploid karyotypes of the Pacific oyster, Crassostrea gigas
Provedor de dados: 5
Autores: Leitao, Alexandra; Boudry, Pierre; Thiriot Quievreux, Catherine.
The G-banding technique was performed on aneuploid karyotypes from gill tissue of the Pacific oyster, Crassostrea gigas, to assess whether chromosome losses could be explained by differential chromosomal susceptibility and to clarify the negative correlation between aneuploidy and growth rate previously reported in different populations of this oyster. The study of 95 G-banded aneuploid karyotypes showed that only 4 of the 10 chromosome pairs (viz. 1, 5, 9, and 10) of C. gigas were affected by the loss of one homologous chromosome. Pairs 1, 9, and 10, which were lost in 56, 33, and 44% of cases, respectively, may be considered to be differentially affected. Hypotheses on this differential chromosomal susceptibility are discussed.
Tipo: Text
Palavras-chave: Oyster; Karyotype; G banding; Growth; Aneuploidy; Huître; Caryotype; Bandes G; Croissance; Aneuploïdie.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/publication-742.pdf

Genetic basis of gametogenesis in diploid and triploid Pacific oysters, Crassostrea gigas
Provedor de dados: 5
Autores: Normand, Julien; Ernande, Bruno; Boudry, Pierre.
Today, triploidy is the most common method used to genetically improve marine bivalve aquaculture production. In the Pacific oyster Crassostrea gigas, triploidy affects many traits. The most proeminent one is reproductive effort, which is greatly reduced compared to diploids. The combined effects of physiological trade-offs between survival, growth and reproduction together with the reduction of reproductive effort in triploids explains the global enhancement of yield observed. However, the sterility of triploid oysters is only partial and some triploid individuals can show normal gametogenesis (i.e. similar to diploids), especially under warm conditions. In diploid oysters, the heritability of reproductive effort has been shown to be relatively low, but a...
Tipo: Text
Palavras-chave: Parentage analysis; Triploidy; Oyster; Quantitative genetics; Gametogenesis.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/acte-4525.pdf

Characterization of a defensin from the oyster Crassostrea gigas - Recombinant production, folding, solution structure, antimicrobial activities, and gene expression
Provedor de dados: 5
Autores: Gueguen, Yannick; Herpin, Amaury; Aumelas, André; Garnier, Julien; Fievet, Julie; Escoubas, Jean-michel; Bulet, Philippe; Gonzalez, Marcelo; Lelong, Christophe; Favrel, Pascal; Bachere, Evelyne.
In invertebrates, defensins were found in arthropods and in the mussels. Here, we report for the first time the identification and characterization of a defensin (Cg-Def) from an oyster. Cg-def mRNA was isolated from Crassostrea gigas mantle using an expressed sequence tag approach. To gain insight into potential roles of Cg-Def in oyster immunity, we produced the recombinant peptide in Escherichia coli, characterized its antimicrobial activities, determined its solution structure by NMR spectroscopy, and quantified its gene expression in vivo following bacterial challenge of oysters. Recombinant Cg-Def was active in vitro against Gram-positive bacteria but showed no or limited activities against Gram-negative bacteria and fungi. The activity of Cg-Def was...
Tipo: Text
Palavras-chave: Crassostrea gigas; Genomic library; Microbiology; Defensin; Oyster.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2127.pdf

Effects of dissolved mercury on embryogenesis, survival, growth and metamorphosis of Crassostrea gigas oyster larvae
Provedor de dados: 5
Autores: Beiras, Ricardo; His, Edouard.
The effects of mercury (Hg) concentrations ranging from 0 (control) to 1024 µg 1-1 upon embryogenesis, survival, growth and metamorphosis of Crassostrea gigas (Thunberg) oyster larvae were investigated. Embryogenesis was abnormal in 50 % of the individuals at 11 µg 1-1 . The 48 h LD50 for D·shaped, umbonate and pediveliger larvae were 33, 115 and 200 µg 1-1 respectively. The increase in LD50 was partially explained by the larval weight increase, although weight-specific tolerance to Hg was higher in smaller larvae. Growth, the most sensitive physiological process studied, was significantly retarded at 4 µg 1-1. The metamorphosis rate was significantly reduced when competent pediveligers were exposed to 64 µg 1-1 for 48 h prior to the addition of the...
Tipo: Text
Palavras-chave: Mercury; Oyster; Larvae; Embryo; Bioassay; Ecotoxicology; Crassostrea gigas.
Ano: 1994
URL: http://archimer.ifremer.fr/doc/00037/14867/12191.pdf

Influence of low temperatures on the survival of the Pacific oyster (Crassostrea gigas) infected with Ostreid herpesvirus type 1
Provedor de dados: 5
Autores: Pernet, Fabrice; Tamayo, David; Petton, Bruno.
Mortalities of oyster seed of Crassostrea gigas associated with ostreid herpes virus OsHV-1 μVar have been observed in many oyster producing countries since 2008. The objective of this study was to further investigate whether low temperature treatments can offer a viable option to mitigate oyster mortalities. An experiment was set-up to further evaluate the effect of low temperature treatments (10 and 13°C vs. 21°C) and their duration (6 d to 83 d) on the survival of oysters previously infected with OsHV-1 μVar by means of exposure to field conditions in areas where mortalities were occurring. Average survival of oysters infected with OsHV-1μVar was 71% after 83 d at low temperatures compared to only 23% in controls maintained at 21°C. During...
Tipo: Text
Palavras-chave: Bivalve; Disease; OsHV-1; Oyster; Temperature; Virus.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00259/37047/35555.pdf

Etude d'un élevage intégré bars-huîtres
Provedor de dados: 5
Autores: Buchet, Vincent; Bluteau, A.
Whatever the hydraulic gestion, an épuration of the fishes sewages is possible with the integrated system studied. The main action is situed in the intermediary pond with a significant decrease of nutrients, especially ammonia, and particulate mineral matters. The oyster's pond have no significant action on nutrients, but their action is real on chlorophyll which become limiting factor in 20% renewal system. One of the effluent, system 1 (renewal 10%) had high suspended matter and low nutrient concentrations. The other (renewal 20%) was poor in supcnded matters (chlorophyll). The system 2 give best oyster's growth, close to traditional nursery performances, with an highest mortality (32%). In the first system, suspended matter concentrations are too high...
Tipo: Text
Palavras-chave: Valorization; Oyster; Pre ongrowing; Seabass; Integrated rearing; Valorisation; Huître; Prégrossissement; Bar; Elevage intégré.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/1996/rapport-1917.pdf

Summer mortality in juvenile cupped oysters : response to selection in the field and in laboratory
Provedor de dados: 5
Autores: Degremont, Lionel; Bedier, Edouard; Soletchnik, Patrick; Ropert, Michel; Samain, Jean-francois; Boudry, Pierre.
The French project "Morest", coordinated by IFREMER, aims to a better understanding of the causes of summer mortalities in juvenile oysters by a multidisciplinary approach. Within this program, a first generation (G1) was bred in 2001 to assess to what extent genetic variability exists for this trait in French populations. 17 half-sib families (HSF) including 44 full-sib families (FSF) were obtained in the G1, and each FSF was reared in three sites along the French coast during the summer period. Significant differences in survival were observed among HSF, clearly indicating a genetic basis for survival. Estimation of heritability for survival was very high: 0.81 &amp;#61617; 0.29. In 2002, 3 "good" HSF and 3 "bad" HSF were selected on their survival...
Tipo: Text
Palavras-chave: Selection; Genetic; Mortalities; Crassostrea gigas; Oyster.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/acte-3439.pdf

Diagnosis of oyster herpes-like virus: development and validation of molecular, immunological and cellular tools "VINO" Third Periodic Progress Report : 4th January 2001 to 3rd January 2002
Provedor de dados: 5
Autores: Renault, Tristan; Davison, Andrew; Xhonneux, Florence; Dorange, Germaine; Culloty, Sarah; Novoa, Beatriz; Dixon, Peter.
Herpesvirus infections have been reported in different bivalves species around the world. Specific diagnostic tools are needed in order ta assess the causative raIe of these agents in mortalities observed among bivalves There is currently a lack of information concerning the occurrence of bivalve herpesviruses. This is probably due ta the lack of suitable diagnostic tools. The basic method for examination of bivalve samples is predominantly histology. This enables the identification of any cellular changes, but is not conclusive for virus identification. Transmission electron microscopy is a necessity for visual confirmation of viral infections. However, histology and electron microscopy are time consuming and inadequate for epidemiological studies. The...
Tipo: Text
Palavras-chave: Pathology; Virology; Diagnosis; Herpes like virus; Virus; Oyster; Detection; OsHV-1; Herpesviridae.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00044/15524/12911.pdf

Essential Fatty Acid Assimilation and Synthesis in Larvae of the Bivalve Crassostrea gigas
Provedor de dados: 5
Autores: Da Costa Gonzalez, Fiz; Robert, Rene; Quere, Claudie; Wikfors, Gary H.; Soudant, Philippe.
Essential fatty acids (EFA) are important for bivalve larval survival and growth. The purpose of this study was to quantitatively assess for the first time through a mass-balance approach dietary EFA incorporation and synthesis within Crassostrea gigas larvae. A first experiment was carried out using two microalgae, Tisochrysis lutea (T) and Chaetoceros neogracile (Cg), as mono- and bi-specific diets. A second experiment using a similar design was performed to confirm and extend the results obtained in the first. Flow-through larval rearing was used for accurate control of food supply and measurement of ingestion. Non-methylene-interrupted fatty acids were synthetized from precursors supplied in the diet: 16:1n-7 and 18:1n-9, mediated by Delta 5...
Tipo: Text
Palavras-chave: Fatty acid; Larvae; Lipids; Metabolism; Oyster; Synthesis.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00268/37962/36086.pdf

Functional Characterization of a short neuropeptide F-related receptor in a Lophotrochozoa, the mollusk Crassostrea gigas
Provedor de dados: 5
Autores: Bigot, Laetitia; Beets, Isabel; Dubos, Marie-pierre; Boudry, Pierre; Schoofs, Liliane; Favrel, Pascal.
Members of the short neuropeptide F (sNPF) family of peptides and their cognate receptors play key roles in a variety of physiological processes in arthropods. In silico screening of GigasDatabase, a specific expressed sequence tag database from the Pacific oyster Crassostrea gigas, resulted in the identification of a receptor (CgsNPFR-like) phylogenetically closely related to sNPF receptors (sNPFRs) of insects. A reverse endocrinology approach was undertaken to identify the peptide ligand(s) of this orphan receptor. Though structurally distinct from insect sNPFs, three RFamide peptides derived from the same precursor, i.e. GSLFRFamide, SSLFRFamide and GALFRFamide, specifically activate the receptor in a dose-dependent manner, with respective EC50 values...
Tipo: Text
Palavras-chave: Oyster; Crassostrea gigas; SNPF; Energy metabolism; Reproduction; Starvation.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00207/31777/30188.pdf

Individual monitoring of gonad development in the European flat oyster Ostrea edulis by in vivo magnetic resonance imaging
Provedor de dados: 5
Autores: Davenel, Armel; Gonzalez, Ricardo; Suquet, Marc; Quellec, Stephane; Robert, Rene.
Previous studies have shown that magnetic resonance imaging is a very appropriate non-invasive technique for quantifying the growth of somatic and gonadic tissues and sex determination in the Pacific oyster, Crassostrea gigas. Despite a thinner gonad, harder to distinguish than that of the Pacific oyster, we showed in this study that it was possible to distinguish and quantify the development of the gonad of the European flat oyster, Ostrea edulis, using a 3D MRI sequence with a suitable finer resolution. Compared to T2-weighted images, theoretically the most appropriate for good anatomical description, T1-weighted images were more suited to gonad observation. The gonad development was quantified by the number of voxels with higher grey level. Larvae were...
Tipo: Text
Palavras-chave: Oyster; Ostrea edulis; Gonad development; Magnetic resonance imaging.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00014/12508/9363.pdf

Impacts des informations produites par l'IFREMER sur la qualité des eaux littorales dans la production et la commercialisation des coquillages
Provedor de dados: 5
Autores: Dubuisson-quellier, Sophie.
La connaissance aussi bien que la gestion des écosystèmes marins suppose de disposer d'un réferentiel d'indicateurs et de mesures capable d'informer sur l'état du milieu. Le zonage, c'est-à-dire le découpage en zones géographiques, participe de la construction de ce réferentiel, notamment lorsqu'il permet ensuite la mise en place de réseaux de mesure pour la surveillance de la qualité du milieu littoral, dans un souci d'observation pour la gestion opérationnelle de ce milieu (politiques d'occupation des espaces, usages différents des espaces côtiers). Le principe du zonage est ancien (Morel, 1996) et peut varier en complexité selon qu'une seule variable descriptive est utilisée, comme dans le cas du zonage thématique basé sur la géographie physique et...
Tipo: Text
Palavras-chave: Oyster; Ostreiculture; Mussel culture; Marennes Oleron Bay; Crassostrea Gigas; Water quality; Aquaculture; Economic impact; Coastal water; Marine pollution; Shellfish culture; SEM; Marennes Oleron bassin; Crassostrea gigas; Economie; Qualite eau; Controle sanitaire; Conchyliculture; Ostreiculture; Developpement aquaculture.
Ano: 2001
URL: https://archimer.ifremer.fr/doc/2001/rapport-1740.pdf

Comparative study on the contamination and decontamination of Japanese oyster Crassostrea gigas and blue mussel Mytilus edulis by oxytetracycline and oxolinic acid
Provedor de dados: 5
Autores: Pouliquen, Hervé; Le Bris, Hervé; Buchet, Vincent; Pinault, Louis.
Marine fish farms use many antibacterial agents to prevent or fight bacterial diseases. The major part of the orally supplied drugs reach the environment, either directly due to excessive feeding and reduced appetite of the cultured fish, or indirectly after passing through the fish. Some of the drugs entering the environment may be taken up by bivalves. Comparative contamination and decontamination of Japanese oyster Crassostrea gigas and blue mussel Mytilus edulis were studied when these bivalves were kept during 10 d in seawater containing oxytetracycline (OTC) or oxolinic acid (OA) at concentrations of 0.15 and 1.50 mg l(-1). After the 10 d exposure at the seawater concentrations of 0.15 and 1.50 mg l(-1), OTC and OA concentrations in bivalve tissues...
Tipo: Text
Palavras-chave: Mussel; Oxolinic acid; Oxytetracycline; Oyster.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/00282/39359/39437.pdf

In vitro research of anti-HSV-1 activity in different extracts from Pacific oysters Crassostrea gigas
Provedor de dados: 5
Autores: Olicard, Cecile; Didier, Yohann; Marty, Christel; Bourgougnon, Nathalie; Renault, Tristan.
Mortalities related to the detection of Ostreid Herpesvirus 1 (OsHV-1) have been previously reported in France among larvae and spat of the Pacific oyster Crassostrea gigas. Adult oysters appear less sensitive to herpesvirus infections, although OsHV-1 has been detected in adults without signs of disease or mortality. This suggests that the virus is able to persist in its host and that adult oysters may be able to control OsHV-1 infection. Little is known about antiviral substances in invertebrates. The present work concerns the research of antiviral substances in adult oyster C. gigas, where putative antiviral activities were monitored using 3 strategies: (1) in metabolites with variable polarity, (2) in peptidic extracts and (3) in crude haemolymph. In...
Tipo: Text
Palavras-chave: Haemolymph; Antiviral peptides; HSV 1; OsHV 1; Antiviral defence; Crassostrea gigas; Oyster.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-2922.pdf

Etude des mécanismes antiviraux développés par les huîtres lors d'infections à virus de type herpès
Provedor de dados: 5
Autores: Olicard, Cecile.
Tipo: Text
Palavras-chave: Cytometry; Herpes like virus; Oyster; Antivirus mechanisms.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/2002/rapport-1769.pdf

Etude de la virulence des Vibrio pathogènes en relation avec la variabilité de la réponse chez l'uître creuse
Provedor de dados: 5
Autores: De Decker, Sophie.
The bacteria of the Vibrio genus are one of the most abundant groups in the aquatic ecosystems. Two species of vibrios, Vibrio splendidus and V. Aestuarianus, have been associated, in some cases, to mortality in flat oyster Crassostrea gigas farms, most of the time during the summer period. This doctoral thesis studies the Vibrio-host interaction and their modulations according to the host's pathogenic virulence and its genetic, physiologic and immunitary parameters. These factors will be characterised by in vitro and in vivo approaches (experimental infection). The characterization of contrasted genetic families according to their sensitivity to these vibrios will enable the implementation of new improvement strategies in oyster farms (prophylactic...
Tipo: Text
Palavras-chave: Immunologie; Physiologie; Paramètres génétiques; Virulence; Oyster; Crassostrea gigas; Pathogène; Vibrio.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3431.pdf

Study of genetic damage in the japanese oyster induced by an environmentally-relevant exposure to diuron: evidence of vertical transmission of dna damage
Provedor de dados: 5
Autores: Barranger, Audrey; Akcha, Farida; Rouxel, Julien; Brizard, Raphael; Maurouard, Elise; Pallud, Marie; Menard, Dominique; Tapie, N.; Budzinski, Helene; Burgeot, Thierry; Benabdelmouna, Abdellah.
Pesticides represent a major proportion of the chemical pollutants detected in French coastal waters and hence a significant environmental risk with regards to marine organisms. Commercially-raised bivalves are particularly exposed to pollutants, among them pesticides, as shellfish farming zones are subject to considerable pressure from agricultural activities on the mainland.  The aims of this study were to determine (1) the genotoxic effects of diuron exposure on oyster genitors and (2) the possible transmission of damaged DNA to offspring and its repercussions on oyster fitness. To investigate these points, oysters were exposed to concentrations of diuron close to those detected in the Marennes-Oleron Basin (two 7-day exposure pulses at 0.4 and 0.6 μg...
Tipo: Text
Palavras-chave: Herbicide; Diuron; Oyster; Genotoxicity; Comet assay; Cytogenetics.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00162/27311/25541.pdf

Croissance des huîtres creuses, Crassostrea gigas, en baie du mont Saint-Michel, avant la restructuration de 2004
Provedor de dados: 5
Autores: Bouget, Jean-francois; Mazurie, Joseph.
This study presents the main results of oyster growth obtained experimentally in 2002 and 2003, in the farming area of Cancale before the leases reorganization of 2004. According to the REMORA monitoring network from 1990 to 2004, the oyster growth in Cancale bay may be characterized by an average annual weight gain (around 30g per year), a rather weak meat content compared to other regional oyster sites, and an exceptional quality of shell (absence of blisters, few Poly do rd). Spatially, the oyster farming area of Cancale shows rather homogeneous performances of breeding, in spite of the muddy southern area. In addition an experimental trial in 2003 allowed to evaluate favourably the potential of the new oyster area of Saint-Benoît : in these...
Tipo: Text
Palavras-chave: Mont Saint Michel; Crassostrea gigas; Growth; Breeding; Oyster; Mont Saint Michel; Crassostrea gigas; Croissance; Ostréiculture; Huître.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/rapport-1637.pdf

Déterminisme du recrutement. Séminaire de Nantes, 2-4 juillet 1984
Provedor de dados: 5
Autores: Ifremer.
The causality of recruitment is of paramount importance for the progress of the control of marine living resources, but its study remains technically complax.The aim of the Nantes panel was to evaluate the state of advancement of three running programs on exploited species (sole, scallops and oysters), and to set out the basis of a wider national program of interest for both basic and targeted research.
Tipo: Text
Palavras-chave: Recrutement; Variabilité; Déterminisme; Sole; Coquille St Jacques; Huître; Recruitment; Variability; Causality; Sole; Scallop; Oyster.
Ano: 1985
URL: http://archimer.ifremer.fr/doc/00136/24713/22766.pdf

Modelling of paralytic shellfish toxin biotransformations in the course of Crassostrea gigas detoxification kinetics
Provedor de dados: 5
Autores: Gueguen, Marielle; Baron, Regis; Bardouil, Michele; Truquet, Philippe; Haberkorn, Hansy; Lassus, Patrick; Barille, Laurent; Amzil, Zouher.
The aim of this study was to evaluate the importance of biotransformation of paralytic shellfish toxins during the detoxification process in contaminated oysters. Mathematical models based upon the detoxification patterns of digestive gland and other tissues were developed. It was demonstrated that biotransformations do not seem to play an important role in digestive gland or other tissue detoxification kinetics with our data set. Moreover, different toxin transfers from digestive gland toward other tissues were investigated. No significant transfer was highlighted in our data set. These first conclusions were drawn after comparing the results obtained from 13 biotransformations and identifiable transfer scenarios. Finally, to determine a more robust...
Tipo: Text
Palavras-chave: Detoxification kinetics modelling; Biotransformation of saxitoxin analogues; Oyster.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00049/16047/14309.pdf

Bonamia ostreae, parasite of the European flat oyster, Ostrea edulis, does not experimentally infect the Japanese oyster, Crassostrea gigas
Provedor de dados: 5
Autores: Renault, Tristan; Cochennec, Nathalie; Grizel, Henri.
The protozoan Bonamia ostreae (Ascetospora) is the etiological agent of bonamiosis, or hemocyte disease of the European fiat oyster, Ostrea edulis (Pichot et al., 1980). Since this infection was first reported from the coast of Brittany (Comps et al., 1980), the parasite has spread rapidly along the French Atlantic coasts (Grizel &amp; Tigé, 1982), and in the European countries including the UK, Holland, lreland and Spain (Bannister &amp; Key, 1982; Van Banning, 1982; Polanco et al., 1984). Under the EEC Council Directive 91/67, this parasitic protozoan is included in list II of Annex A. Serious pathogen agents for molluscs that should be obligatorily declared are placed in this list
Tipo: Text
Palavras-chave: Infection; Protozoan; Oyster; Ostrea edulis; Bonamia ostreae.
Ano: 1995
URL: http://archimer.ifremer.fr/doc/1995/publication-2892.pdf

Putative antiviral activity in hemolymph from adult Pacific oysters, Crassostrea gigas
Provedor de dados: 5
Autores: Olicard, Cecile; Renault, Tristan; Torhy, Corinne; Benmansour, Abdenour; Bourgougnon, Nathalie.
Innate, non-specific resistance mechanisms are important to pathogens, particularly for delaying virus replication at the onset of infection, Innate immunity constitutes the first line of defense in vertebrates and is the only one in invertebrates. Little is known about possible antiviral substances in invertebrates. The present work concerns a Study of antiviral substances in hemolymph from adult Crassostrea gigas oysters. Despite the detection of cytotoxicity in fresh filtered hemolymph for both mammalian (CC50: 750 mu g/ml) and fish cells (CC50: &gt; 2000 mu g/ml for EPC cells and 345 mu g/ml for RTG-2 cells), an antiviral substance was detected. Fresh filtered hemolymph was capable of inhibiting the replication of herpes simplex virus type I in vitro...
Tipo: Text
Palavras-chave: Hemolymph; VHSV; IPNV; HSV; Antiviral defense; Crassosirea gigas; Oyster.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-774.pdf

Detection of ostreid herpesvirus 1 DNA by PCR in bivalve molluscs: A critical review
Provedor de dados: 5
Autores: Batista, Frederico; Arzul, Isabelle; Pepin, Jean-francois; Ruano, Francisco; Friedman, Carolyn S.; Boudry, Pierre; Renault, Tristan.
Herpes-like viral infections have been reported in different bivalve mollusc species throughout the world. High mortalities among hatchery-reared larvae and juveniles of different bivalve species have been associated often with such infections. The diagnosis of herpes-like viruses in bivalve molluscs has been performed traditionally by light and transmission electron microscopy. The genome sequencing of one of these viruses, oyster herpesvirus 1 (OsHV-1), allowed the development of DNA-based diagnostic techniques. The polymerase chain reaction (PCR) has been used for the detection of OsHV-1 DNA in bivalve molluscs at different development stages. In addition, the PCR used for detection of OsHV-1 has also allowed the amplification of DNA from an OsHV-1...
Tipo: Text
Palavras-chave: Oyster; Bivalve molluscs; PCR; Detection; OsHV 1; Herpesvirus.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2322.pdf

Marqueurs microsatellites chez l'huître plate Ostrea edulis l. : caractérisation et applications à un programme de sélection pour une résistance au parasite Bonamia ostreae et à l'etude de populations naturelles
Provedor de dados: 5
Autores: Launey, Sophie.
The flat oyster Ostrea edulis L. is the indigenous oyster of the Atlantic as well as the Mediterranean coasts of Europe.  Its commercial exploitation dates back to Antiquity but its breeding is now threatened by two parasitic protozoa, among which Bonamia ostreae. Various aspects of the genetics of this species' natural and farmed populations have been studied with the aid of microsatellite markers.  At first, the implementation and the screening of two partial genomic libraries made it possible to identify 28 new microsatellite loci. Analysis of the segregation of 12 of these loci and of two enzymatic loci shows that most microsatellite loci are transmitted in a Mendelian way, but some loci have significant segregation distortions. Moreover, seven linkage...
Tipo: Text
Palavras-chave: Microsatellites markers; Parasite; Bonamia ostreae; Oyster; Ostrea edulis; Marqueurs microsatellites; Parasite; Bonamia ostreae; Huître; Ostrea edulis.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/1998/these-1919.pdf

What role for genomics in fisheries management and aquaculture?
Provedor de dados: 5
Autores: Wenne, Roman; Boudry, Pierre; Hemmer-hansen, Jakob; Lubieniecki, Krzysztof P.; Was, Anna; Kause, Antti.
The development and application of genomics has been facilitated in a number of fields by the availability of new methodologies and tools, such as high throughput DNA sequencing and complementary DNA (cDNA) microarrays. Genomic tools are already used in research on commercially important fish and shellfish species. Thousands of expressed sequence tags (EST) are now available for some of these species, and the sequencing of complete genomes of tilapia, cod, salmonids, flatfishes, sea bass and Pacific oyster has been proposed. Microarray technology through simultaneous analysis of the expression of thousands of genes allows the identification of candidate genes involved in the function of multiple physiological, morphological and behavioural traits of...
Tipo: Text
Palavras-chave: Oyster; Fish; Quantitative trait loci; Mariculture; Fisheries; Genetics; Genomics.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2927.pdf

Response to unintentional selection for faster development associated with inbreeding depression in Crassostrea gigas larvae, resulting from a broodstock selective breeding plan
Provedor de dados: 5
Autores: Taris, Nicolas; Batista, Frederico; Marissal, Eric; Boudry, Pierre.
Direct and indirect consequences of selective breeding in marine bivalves still remain largely unexplored. For species with two-phase life cycle, like the Pacific oyster (Crassostrea gigas), most studies have focused on juvenile and adult stages, but relatively few have focused on juvenile and adult stages, but relatively few have considered the larval stage, especially in a domestication context. We assessed the impact of hatchery practices on larval traits, notably on larval growth (due to the culling of slow growing larvae), by the study of larval progenies. Larvae originating from crosses using parental oysters both from natural beds and from hatchery broodstock which had been selected for adult growth and shell shape for seven generations. A set of...
Tipo: Text
Palavras-chave: Inbreeding depresion; Larvae stage; Genetic variability; Hatchery; Domestication; Genetic; Crassostrea gigas; Oyster.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/acte-3337.pdf

L'éthoxyrésorufine-o-déethylase, les adduits à l'ADN et les mocronuclei dans les organismes marins. Application à la surveillance des effets biologiques sur les côtes françaises
Provedor de dados: 5
Autores: Burgeot, Thierry.
Three biomarkers [ethoxyresorufm-o-deethylase (EROD), DNA adducts and micronuclei (MN) were studied for biomonitoring applications along French coasts. EROD was developed at an experirnental stage in two pilot sites, Seine Bay and Fos sur Mer, using the dab (Limanda limanda), dragon et (Callionymus lyra), red mullet (Mullus barbatus) and comber (Serranus hepatus) as target species. Higbest EROD activity was observed in the subestuarial part of Seine Bay and at the stations closest to sources of pollution from Cortiou and Fos sur Mer. The suitable number of fish for detection of a significant difference between two EROD activities was deterrnined as a function of sampling variance and a preselected statistical power. A preliminary study on hepatocytes in a...
Tipo: Text
Palavras-chave: Ethoxyrésorufine-o-déethylase; Adduits à l'ADN; Micronuclei; Poisson; Moule; Huître; Biosurveillance; Ethoryresorufin-o-deethylase; DNA adducts; Micronuclei; Fish; Mussel; Oyster; Biomonitoring.
Ano: 1994
URL: http://archimer.ifremer.fr/doc/00443/55462/56984.pdf

Impact of the reproduction dynamics on genetic variation in the European flat oyster Ostrea edulis
Provedor de dados: 5
Autores: Lapegue, Sylvie; Taris, Nicolas; Lallias, Delphine; Bonhomme, Francois; Boudry, Pierre.
The European flat oyster (Ostrea edulis L.) is a marine bivalve whose natural geographical distribution ranges along the European Atlantic coast from Norway to Morocco, in addition to the Mediterranean and Black Sea. The latest results obtained on the genetic differentiation between these populations have led us to pursue studies at a finer scale, in order to estimate the effective number of breeders and the temporal dynamics of reproduction and, more specially, recruitment. Several experiments were performed to document (1) the variance in allele frequencies during a natural settlement period; (2) the paternal contribution to fertilization by analyzing larvae sampled at the brooding stage within individual females; (3) the variance of individual...
Tipo: Text
Palavras-chave: Ostrea edulis; Oyster; Sexual reproduction; Population dynamics; Oyster culture; Inbreeding; Heterosis; Genetic isolation; Genetic diversity; Breeding success; Biological fertilization.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/acte-3436.pdf

Development of a TaqMan PCR assay for the detection of Bonamia species
Provedor de dados: 5
Autores: Corbeil, Serge; Arzul, Isabelle; Diggles, Ben; Heasman, Mike; Chollet, Bruno; Berthe, Franck; Crane, Mark St. J.
The development of molecular diagnostic assays with increased sensitivity compared with conventional histological techniques is highly desirable for effective management of bonamiosis in cultured oyster stocks and wild populations. A real-time TaqMan PCR assay was developed for the specific detection of Bonamia species in infected oyster tissues. The TaqMan assay was shown to be significantly more sensitive than histopathology. Although a real-time TaqMan PCR assay is comparable with conventional PCR in terms of sensitivity, it offers the advantages that it is a rapid test and has a very low risk of sample cross-contamination. Furthermore, it can be optimised to quantify the parasite load in samples. The assay detected Bonamia isolates from Australia, New...
Tipo: Text
Palavras-chave: Oyster; Real time TaqMan PCR assay; Bonamia spp.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1980.pdf

Biological characteristics of sperm in European flat oyster (     Ostrea edulis     )
Provedor de dados: 5
Autores: Suquet, Marc; Pouvreau, Stephane; Queau, Isabelle; Boulais, Myrina; Le Grand, Jacqueline; Ratiskol, Dominique; Cosson, Jacky.
n brooding mollusc species that incubate larvae before their release in seawater, the biology of gametes remains poorly explored. The present study describes some biological characteristics of sperm of the European flat oyster, a native species that has been over-exploited in the past and is nowadays classified as an endangered species in Europe. Flat oysters were collected by divers in the Rade de Brest (Finistère, France), during its natural reproduction period. Gonadal pH is acidic (6.31 ± 0.10). Spermatozoa are clustered in spermatozeugmata, an acellular structure in which the sperm heads are embedded. After their transfer in seawater, spermatozeugmata have a mean diameter of 64 ± 3 μm and they release free spermatozoa for a mean duration of...
Tipo: Text
Palavras-chave: Oyster; Ostrea edulis; Brooding species; Sperm; Spermatozeugmata; Endangered species.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00454/56539/58245.pdf

Caractérisation de la virulence d'une souche de Vibrio aestuarianus, pathogène de l'huître Crassostrea gigas
Provedor de dados: 5
Autores: Labreuche, Yannick.
In France. shellfish production is a traditional. well-established industry. mainly based upon commercial farming of the Pacifie oyster. Crassostrea gigas. Since the 1980's, annual mass mortalities of C. gigas have been reported during summer. Several studies on this subject have demonstrated that these mortality outbreaks resulted from complex interactions between the physiologieal andJor genetic status of the oysters. environmental factors, and one or more infectious agents, among which are bacteria of the genus Vibrio.
Tipo: Text
Palavras-chave: Huître; Crassostrea gigas; Bactéries; Vibrio aestuarlanus; Pathogénicité; Produits extracellulaires; Métalloprotéase; Hémocytes; Interactions hôte/pathogène; Oyster; Crassostrea gigas; Bacteria; Vibrio aestuarianus; Pathogenicity; Extracellular products; Metalloprotease; Hemocytes; Host/pathogen interactions.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/00034/14561/11859.pdf

Validation in commercial conditions of the response to selection of the European flat oyster Ostrea edulis for resistance to Bonamia ostreae
Provedor de dados: 5
Autores: Bedier, Edouard; Langlade, Aime; Angeri, Stéphane; Brizard, Raphael; Nerlovic, V.; Glize, Philippe; Haffray, Philippe.
Since the outbreaks of the parasitosis with Marteilia refringens and Bonamia ostreae in the last 60's, the French production of the European flat oyster dropped from 20000 mT to less than 1500 mT currently, leaving the French shellfish farming in situation of virtually monoculture of the Pacific cupped oyster Crassostrea gigas. To sustain this traditional culture, Ifremer has developed, at the experimental level, a genetic selection for a better tolerance to Bonamia ostreae which led to an improvement of survivals. The transfer of these results to the business scale requires the control of the reproduction in hatchery and the adaptation of the cycle of production to the constraints of seedlings in deep water as practised in Brittany (France). That's why a...
Tipo: Text
Palavras-chave: Selection; Genetic; Bonamia ostreae; Parasite; Ostrea edulis; Oyster.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/acte-3313.pdf

Comparative histological study of gametogenesis in diploid and triploid pacific oysters (Crassostrea gigas) reared in an estuarine farming site in France during the 2003 heatwave
Provedor de dados: 5
Autores: Normand, Julien; Le Pennec, Marcel; Boudry, Pierre.
We compared the temporal dynamics of gametogenesis in diploid and triploid Pacific oysters (Crassostrea gigas) using histology. Oysters were reared in an estuarine farming site in Brittany over 3 years and their gametogenesis was monitored over the exceptionally hot summer of 2003. Both diploids and triploids showed active gametogenesis, but a high proportion of triploids remained at early stages of gonad development. Gametogenesis of triploids was characterized by the simultaneous occurrence of gonias and immature cytes together with mature gametes rather than overall retardation, though some triploids showed complete gonad maturation. Evidence of spawning was seen in both groups, and the quantity of germinal products emitted appeared to be similar in...
Tipo: Text
Palavras-chave: Triploidy; Crassostrea gigas; Oyster; Gametogenesis.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4152.pdf

Population Genetics of the Eastern Oyster Crassostrea virginica (Gmelin, 1791) in the Gulf of Mexico
Provedor de dados: 5
Autores: Varney, Robin L.; Galindo, Clara; Cruz, Pedro; Gaffney, Patrick M.
Genetic variation in eastern oysters (Crassostrea virginica) collected from 13 sites in the Gulf of Mexico was examined using a combination of mitochondrial DNA (mtDNA) sequencing, mtDNA restriction fragment length polymorphism analysis, and nuclear single nucleotide polymorphism analysis. Both mitochondrial and nuclear markers showed significant differentiation among samples. Combined with previous allozyme and microsatellite data, these results indicate considerable population subdivision throughout the Gulf of Mexico, despite the potentially homogenizing effect of larval dispersal.
Tipo: Text
Palavras-chave: Gulf of Mexico; Mitochondrial DNA; Single nucleotide polymorphism; Genetics; Oyster; Crassostrea virginica.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-7397.pdf

Les risques conchylicoles en Baie de Quiberon. Troisième partie : le risque d’hypoxie pour l’huître creuse Crassostrea gigas. Rapport final du projet Risco 2010-2013
Provedor de dados: 5
Autores: Stanisiere, Jean-yves; Mazurie, Joseph; Bouget, Jean-francois; Langlade, Aime; Gabellec, Raoul; Retho, Michael; Quinsat, Kevin; Leclerc, Emilie; Cugier, Philippe; Dussauze, Morgan; Menesguen, Alain; Dumas, Franck; Gohin, Francis; Augustin, Jean-marie; Ehrhold, Axel; Sinquin, Jean-marc; Goubert, Evelyne; Dreano, Alain.
The project “Risco”, supported by the “Pôle Mer” and funded by the Regional Council of Brittany, deals with specific risks of mortality of oysters, Crassostrea gigas, cultivated on the bottom, in a subtidal bay of South Brittany : the bay of Quiberon (56, France). Massive mortalities of oysters were reported in summer 2006 in this bay, exclusively located in the deep muddy area with a positive gradient eastward. A validated biogeochemical model was applied in order to simulate the dissolved oxygen over 2000-2006 : it revealed several episodes of hypoxia, more or less intense according to years, but with the same spatial distribution. This approach proved 2006 to be the most hypoxic year since 2000. The hypoxia was due to a rare conjunction of 3 factors :...
Tipo: Text
Palavras-chave: Baie Quiberon; Crassostrea gigas; Huître; Mortalité; Croissance; Hypoxie; Oxygène; Modèle; Upwelling; Loire; Vilaine; Quiberon; Crassostrea gigas; Oyster; Mortality; Growth; Hypoxia; Oxygen; Model; DEB; Upwelling; Loire; Vilaine.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00180/29131/27535.pdf

Écologie de la reproduction de l’huître Crassostrea gigas en lagune méditerranéenne
Provedor de dados: 5
Autores: Lagarde, Franck.
The Mediterranean lagoons host many anthropogenic uses including shellfish aquaculture since the beginning of the 20th century. Imported in 1970, the cupped oyster, Crassostrea gigas, has adapted perfectly and has allowed an important development of oyster’s industry until 2008, the year of occurence of spat outbreak related to the emergence of an Ostreid Herpes-virus μvar. The scarcity of spat and the speculation on this product changed regionally cultural practices and the supply of juveniles, with in particular the wish of developing a local activity of spat collection. However the cycle of reproduction of the species and the recruitment of juveniles were poorly known in lagoon environments. In this context, the objective of this thesis is to...
Tipo: Text
Palavras-chave: Huître; Écologie larvaire; Ressource trophique; Connectivité; Recrutement; Lagune côtière; Oyster; Larval ecology; Trophic resource; Connectivity; Recruitment; Coastal lagoon.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00472/58347/60901.pdf

Differential Mortality and High Viral Load in Naive Pacific Oyster Families Exposed to OsHV-1 Suggests Tolerance Rather than Resistance to Infection
Provedor de dados: 5
Autores: Agnew, M. Victoria; Friedman, Carolyn S.; Langdon, Christopher; Divilov, Konstantin; Schoolfield, Blaine; Morga, Benjamin; Degremont, Lionel; Dhar, Arun K.; Kirkland, Peter; Dumbauld, Brett; Burge, Colleen A.
Pacific oysters, Crassostrea gigas, are one of the most productive aquaculture species in the world. However, they are threatened by the spread of Ostreid herpesvirus-1 (OsHV-1) and its microvariants (collectively “µvars”), which cause mass mortalities in all life stages of Pacific oysters globally. Breeding programs have been successful in reducing mortality due to OsHV-1 variants following viral outbreaks; however, an OsHV-1-resistant oyster line does not yet exist in the United States (US), and it is unknown how OsHV-1 µvars will affect US oyster populations compared to the current variant, which is similar to the OsHV-1 reference, found in Tomales Bay, CA. The goals of this study were to investigate the resistance of C. gigas juveniles produced by the...
Tipo: Text
Palavras-chave: OsHV-1; Mu vars; Oyster; Virus; Tolerance; Virulence; QPCR.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00665/77739/79862.pdf

Endurcissement du naissain d’huîtres creuses, Crassostrea gigas par le niveau d’exondation ou la densité d’élevage : récapitulatif d’essais conduits entre 2004 et 2007 en rivière d’Auray (56), pour réduire les mortalités estivales
Provedor de dados: 5
Autores: Mazurie, Joseph; Bouget, Jean-francois; Langlade, Aime; Claude, Serge.
This report summarizes a list of husbandry experiments conducted between 2004 and 2007 so as to reduce the summer mortalities of the oyster Crassostrea gigas by farming practices. The Japanese technique so‐called “hardening”, based on nursing the young oysters (less than 1 year‐old) in intertidal areas with high air exposure, is tested and adapted. Significant improvements of survival rates (e.g. 60% survival instead of 40% survival rate) have been obtained by transferring the spat only a few month (between march and june‐july) on “high” inter‐tidal farming plots (up to 40% of mean air exposure time). In such conditions, growth is transiently reduced, but a compensatory growth seems to happen when oysters are transferred back on low concessions. Another...
Tipo: Text
Palavras-chave: Huître; Crassostrea gigas; Mortalité; Endurcissement; Exondation; Densité; Oyster; Crassostrea gigas; Mortality; Hardening; Air exposure; Density.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00042/15350/12705.pdf

Space-time clustering of mortality notifications in Pacific oysters of Charente sluices, France, 2008-2010
Provedor de dados: 5
Autores: Lupo, Coralie; Mandard, Yann-vari; Arzul, Isabelle; Francois, Cyrille; Garcia, Celine; Renault, Tristan; Bareille, Nathalie.
Current monitoring of exceptional mortality events of oysters in France consists in passive surveillance, leading to delayed investigation of causation by scientists and management by policy makers. Early detection of clusters of mortality events in time and space would increase possibilities for their investigation and management. A space-time cluster analysis of existing mortality notifications in Pacific oysters was conducted in France, Charente sluices, from 2008 to 2010. As an example of potential demographic confounder of clustering, the analyses were adjusted on oyster age. Several clusters were identified in space and time each studied year. Patterns of mortality notifications were consistent with the introduction and spread of a contagious disease...
Tipo: Text
Palavras-chave: Notification; Oyster; Mortality; Cluster analysis; Saptiotemporal.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00058/16915/14393.pdf

Ecophysiological study on the Pacific oyster Crassostrea gigas naturally infected by a Chlamydia-like microorganism : effect of infection level and diet on oyster physiological responses
Provedor de dados: 5
Autores: Soletchnik, Patrick; Goulletquer, Philippe; Cochennec, Nathalie; Renault, Tristan; Geairon, Philippe.
A population of Pacific ovsters, Crassostrea gigas, infected with a Chlamydia-like procaryote was reared to compare infection trends under three different feeding conditions: a starved condition, an  intermediate condition with a diet of Skeletonema costatllm, and a mixed algal diet. Several physiological and pathological criteriJ: presence of gill abnormality; microscopic examination, basophilic intracytoplasmic inclusions, Feulgen reaction; condition index, filtration, food consumptiQn; fecal production and respiration were used to compare the various modalities one month after the initiation of the experiment. The Irodality of starved oysters showed reduce physiological performances in terms of scope for growth and condition index compared to oysters...
Tipo: Text
Palavras-chave: Pathogen; Chlamydia; Procaryote; Crassostrea gigas; Oyster; Ecophysiology; Pathogène; Chlamydia; Procaryote; Crassostrea gigas; Huître; Ecophysiologie.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/1998/publication-2741.pdf

Chromosome loss in bi-parental progenies of tetraploid Pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: Mccombie, Helen; Lapegue, Sylvie; Cornette, Florence; Ledu, Christophe; Boudry, Pierre.
Alterations of chromosome number have been observed in the somatic tissue of Crassostrea gigas diploids and artificial polyploids. Tetraploid oysters with abnormal chromosome numbers in some or all of their tissue are considered undesirable as parents either for triploids (produced via a cross with diploids and of aquacultural interest) or for tetraploid breeding. Aneuploid tetraploid oysters may confer the tendency to lose chromosomes and to revert to lower ploidy levels to their offspring. More directly, their offspring could have a lower ploidy because of potential links between somatic and gametic chromosome loss. The present study evaluated the phenomenon in six bi-parental tetraploid families bred from parents of differing somatic ploidy quality. The...
Tipo: Text
Palavras-chave: Crassostrea gigas; Mitosis; Chromosome; Cytogenetics; Aneuploid; Polyptoid; Tetraploid; Oyster.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-633.pdf

Demonstration of a true phenoloxidase activity and activation of a ProPO cascade in Pacific oyster, Crassostrea gigas (Thunberg) in vitro
Provedor de dados: 5
Autores: Hellio, Claire; Bado Nilles, Anne; Gagnaire, Beatrice; Renault, Tristan; Thomas-guyon, Helene.
The prophenoloxidase (ProPO) system is the origin of melanin production and is considered to be an innate defence mechanism in invertebrates. In different bivalve species, phenoloxidase (PO) is present in the haemolymph as an inactive form of ProPO. The present study focuses on the Pacific adult oyster, Crassostrea gigas, an economically important bivalve species along French coasts. The results indicate that many factors may inhibit the PO-like activity. These include: phenylthiourea (PTU), sodium diethylthiocarbamate (DETC), beta-mercaptoethanol and tropolone, which repressed the spontaneous PO activity. The activation of PO-like activity in C. gigas acellular fraction by lipopolysaccharide (LPS) involved participation of other factors, including at...
Tipo: Text
Palavras-chave: Prophenoloxidase; Phenoloxidase; Oyster; Immunity; Defence; Crassostrea gigas.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2926.pdf

Center for Independent Experts (CIE) Review of the Status of the Eastern Oyster (Crassostrea virginica)
Provedor de dados: 5
Autores: Goulletquer, Philippe.
NOAA’s National Marine Fisheries Services (NMFS) received a petition to list the Eastern oyster (Crassostrea virginica) as either threatened or endangered under the Endangered Species Act (ESA). The Eastern oyster is an emblematic species in the US coastal states, playing a significant role at various levels: shaping coastal social communities, providing a commercial activity (public fishery &amp; aquaculture) and recreational - amenity benefits, and as a keystone species in highly diverse and sensitive ecosystems (estuaries). This petition is likely the result of concerns regarding the partial collapse of public fisheries in several states as well as from the resulting damages to this species induced by severe hurricanes. A Biological Review Team (BRT)...
Tipo: Text
Palavras-chave: Biology; Habitat threats; Predation; Disease; Bivalvia; Crassostrea virginica; Oyster; Recommendations.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/00043/15458/12833.pdf

Du concept de santé à la détermination d’intervalles de référence chez l’huître creuse Crassostrea gigas
Provedor de dados: 5
Autores: Francois, Cyrille.
Of interest of everyone, health is not an easy concept to figure out. Although there is no universal definition of health, its various uses and meanings allow us to specify its biological, psychic and social dimensions. In animal health, the biological dimension remains the most studied, there is therefore no consensual definition of international animal health. So how to understand the health of marine shellfish? A living being can be functionally described in physiopathology by monitoring biomarkers under laboratory conditions. In men and many animals, "normal" biomarker values have been proposed; these have been determined by carrying out measurements or observations in samples of healthy populations, the rigorous selection of these populations and...
Tipo: Text
Palavras-chave: Santé; Huître; Valeurs de référence; Filtration; Consommation d’oxygène; Health; Oyster; Reference values; Clearance rate; Oxygen consumption rate.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00610/72189/70970.pdf

Approche des relations entre  a croissance de l'huître Crassostrea  gigas et le milieu dans le bassin d'Arcachon
Provedor de dados: 5
Autores: Maurer, Daniele.
study of the experimental growth of the oyster Crassostrea gigas was undertaken of 1985 to 1988, parallel to a follow-up hydrobiologic of the medium, in three sites of the basin of Arcachon. - The characteristics of growth of the studied sites proved very stable during various years ; they are also very different from one site to another, the performances being able to vary the simple one with the double of the center of the basin towards the exit on the ocean. It is during the summer and of the autumn that the difference is established between the sectors, the spring growths being similar. The hierarchy observed is associated a more or less great precocity of the laying. - A gradient influences continental oceanic-influence is observed, resulting in more...
Tipo: Text
Palavras-chave: Ostreiculture; Oyster; Hydrobiology; Growth; Bay of Arcachon; Crassostrea gigas; Ostréiculture; Huître; Hydrobiologie; Croissance; Baie d'Arcachon; Crassostrea gigas.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/1989/rapport-1645.pdf

Taxonomie de l'huître naine Ostreola stentina
Provedor de dados: 5
Autores: Lapegue, Sylvie; Ben Salah, Inès; Batista, Frederico; Heurtebise, Serge; Neifar, Lassad; Boudry, Pierre.
Despite the economic importance of numerous oyster species throughout the world, our knowledge of their systematics and phylogeography remains fragmentary. In Europe, the indigenous species, Ostrea edulis, suffered overexploitation as well as two successive parasitosis over the last century. However, this species is still cultivated in Europe, and especially in Spain and France. Its distribution area stretches from the Atlantic coasts of Europe to the north of Africa as well as around the Mediterranean and Black Sea. Its Mediterranean and South Atlantic distribution area is shared with another indigenous species, the dwarf oyster, Ostreola stentina. Its very small adult size (a few centimetres) makes its culture pointless from a commercial point of view....
Tipo: Text
Palavras-chave: Ostreola stentina; Oyster; Taxonomy; Ostreola stentina; Huître; Taxonomie.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/acte-3364.pdf

Impacts of Deepwater Horizon oil and associated dispersant on early development of the Eastern oyster Crassostrea virginica
Provedor de dados: 5
Autores: Vignier, J.; Donaghy, L.; Soudant, P.; Chu, F. L. E.; Morris, J. M.; Carney, M. W.; Lay, C.; Krasnec, M.; Robert, Rene; Volety, A. K.
The explosion of the Deepwater Horizon (DWH) oil platform resulted in large amounts of crude oil and dispersant Corexit 9500A® released into the Gulf of Mexico and coincided with the spawning season of the oyster, Crassostrea virginica. The effects of exposing gametes and embryos of C. virginica to dispersant alone (Corexit), mechanically (HEWAF) and chemically dispersed (CEWAF) DWH oil were evaluated. Fertilization success and the morphological development, growth, and survival of larvae were assessed. Gamete exposure reduced fertilization (HEWAF: EC201 h = 1650 μg tPAH50 L− 1; CEWAF: EC201 h = 19.4 μg tPAH50 L− 1; Corexit: EC201 h = 6.9 mg L− 1). CEWAF and Corexit showed a similar toxicity on early life stages at equivalent nominal concentrations....
Tipo: Text
Palavras-chave: Deepwater Horizon oil; Oyster; Fertilization; CEWAF; Corexit; PAH.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00277/38853/42693.pdf

Recent advances in EST sequencing in Crassostrea gigas: towards the sequencing of the Pacific oyster genome
Provedor de dados: 5
Autores: Boudry, Pierre; Huvet, Arnaud; Lapegue, Sylvie; Sauvage, Christopher; Tanguy, A.; Moraga, D.; Goostrey, A.; Prunet, P.; Boulo, Viviane; Gueguen, Y.; Moal, Jeanne; Fleury, Elodie; Samain, Jean-francois; Mathieu, M.; Favrel, P.
Rationale for EST and genome sequencing of the Pacific oyster: • its membership of the Lophotrochozoa, an little studied branch of the Eukaryotes, • its worldwide aquacultural importance (4.2 million metric tons, worth 3.5 billion US dollars), • its high fecundity, with concomitantly high DNA polymorphism, • its use as a biosensor of coastal pollution. In 2004, an international community of biologists, the Oyster Genome Consortium (OGC) led by D. Hedgecock (University of Southern California) and uniting 70 participants from 10 countries, first presented the Pacific oyster Crassostrea gigas as a genome-sequencing candidate to Joint Genome Institute (JGI, USA) (Hedgecock et al., 2005). Besides this project (that remains to be accepted), several EST...
Tipo: Text
Palavras-chave: Characteristics; Genome size; Genome; Crassostrea gigas; Oyster; Genetic.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3414.pdf

Cultured heart cells from oyster: an experimental approach for evaluation of the toxicity of the marine pollutant tributyltin
Provedor de dados: 5
Autores: Droguet, Mickael; Devauchelle, Nicole; Pennec, Jean-pierre; Quinn, Brian; Dorange, Germaine.
European Community regulations on chemicals promote alternative methods to test substances presenting potential risks for the environment. In the present work, cultured atrial cells isolated from oyster (Crassostrea gigas) were used as an experimental model to investigate the toxicity of tributyltin (TBT) after short-time exposure at concentrations representative of those that can be measured in seawater, marine sediments and/or bivalves bioaccumulating this pollutant. In vitro and in vivo assays produce values of the same order of magnitude for both animal/cell survival and heart/cardiomyocyte beating rate. The survival rate of whole animals decreased from 10(-6) M TBT after 3 days. For cultured cells, the viability, evaluated using 3-(4,...
Tipo: Text
Palavras-chave: Oyster; Heart cells; Flow cytometry; Tributyltin; Toxicity; Antifouling.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00089/20032/17688.pdf

The taxonomic status and origin of the Portuguese oyster Crassostea angulata (Lamark, 1819)
Provedor de dados: 5
Autores: Batista, Frederico; Leitao, Alexandra; Huvet, Arnaud; Lapegue, Sylvie; Heurtebise, Serge; Boudry, Pierre.
The taxonomic status of the Portuguese oyster Crassostrea angulata and the Pacific oyster Crassostrea gigas has often been a matter of controversy. Based on larval shell morphology, experimental hybridisation and electrophoretic studies of enzyme polymorphism several authors have considered these two species as being synonymous. During the recent years, several genetic studies based on mitochondrial DNA and microsatellites data have provided evidences that the two taxa are genetically distinct although closely related. Furthermore, karyotype analyses have also highlighted the close genetic similarity of these taxa in comparison with other cupped oyster species. However, a comparative analysis of restriction enzymes ideograms revealed differences between...
Tipo: Text
Palavras-chave: Geographical origin; Phylogenetic; Genetic; Taxonomic status; Crassostrea angulata; Oyster.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/acte-3433.pdf

Characterization of GnRH-related peptides from the Pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: Bigot, Laetitia; Zatylny-gaudin, Celine; Rodet, Franck; Bernay, Benoit; Boudry, Pierre; Favrel, Pascal.
Gonadotropin-releasing hormone (GnRH), a key neuropeptide regulating reproduction in vertebrates has now been characterized in a number of non-vertebrate species. Despite the demonstration of its ancestral origin, the structure and the function of this family of peptides remain poorly known in species as distant as lophotrochozoans. In this study, two GnRH-related peptides (Cg-GnRH-a and CgGnRH-G) were characterized by mass spectrometry from extracts of the visceral ganglia of the Pacific oyster Crassostrea gigas. These peptides showed a high degree of sequence identity with GnRHs of other mollusks and annelids and to a lesser extent with those of vertebrates or with AKH and corazonins of insects. Both the mature peptides and the transcript encoding the...
Tipo: Text
Palavras-chave: Mollusk; Bivalve; Oyster; Neuroendocrinology; Reproduction; GnRH.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00079/19003/17477.pdf

Infections virales chez les huîtres Crassostrea angulata Lmk. et Crassostrea gigas Th.
Provedor de dados: 5
Autores: Comps, Michel; Duthoit, Jean-louis.
Two viral infections associated to some epizooties have been observed in Crassostrea angulata Lmk. The first one concerns the Gill disease in which the viral damages go hand in hand with a cellular hypertrophy, while, in the second one, the contaminated cells are associated with a deterioration of the connective tissue. These branchial necrosis associated to a virus have been observed again recently in some Portuguese oysters from the natural deposits of the Cadix (Spain) area. Moreover, the study of the summer mortalities (July 1977) in the oyster Crassostrea gigas Th. demonstrated the presence in this species of a virus of the same type as the one associated to the massive mortalities of the Portuguese oyster. In both cases, the viral morphogenesis takes...
Tipo: Text
Palavras-chave: Oyster; Crassostrea gigas; Crassostrea angulata; Pathology; Virus; Huître; Crassostrea gigas; Crassostrea angulata; Pathologie; Virologie.
Ano: 1979
URL: http://archimer.ifremer.fr/doc/1979/publication-5922.PDF

Induction of apoptosis by UV in the flat oyster, Ostrea edulis
Provedor de dados: 5
Autores: Gervais, Ophelie; Renault, Tristan; Arzul, Isabelle.
Apoptosis is a fundamental feature in the development of many organisms and tissue systems. It is also a mechanism of host defense against environmental stress factors or pathogens by contributing to the elimination of infected cells. Hemocytes play a key role in defense mechanisms in invertebrates and previous studies have shown that physical or chemical stress can increase apoptosis in hemocytes in mollusks. However this phenomenon has rarely been investigated in bivalves especially in the flat oyster Ostrea edulis. The apoptotic response of hemocytes from flat oysters, O. edulis, was investigated after exposure to UV and dexamethasone, two agents known to induce apoptosis in vertebrates. Flow cytometry and microscopy were combined to demonstrate that...
Tipo: Text
Palavras-chave: Apoptosis; Hemocyte(s); Oyster; Ostrea edulis; UV; Flow cytometry; Microscopy.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00270/38160/36295.pdf

Variable microsatellites in the Pacific Oyster Crassostrea gigas and other cupped oyster species
Provedor de dados: 5
Autores: Huvet, Arnaud; Boudry, Pierre; Ohresser, M; Delsert, Claude; Bonhomme, F.
Source/description : Genomic DNA was extracted from a whole Pacific oyster (C. gigas) after grinding in liquid nitrogen. Purified DNA was then digested by a mix of 3 restriction enzymes (AluI, RsaI, HaeIII). DNA fragments ranging from 250 to 500 bp were size-selected by agarose gel electrophoresis and ligated into the dephosphorylated blunt-ended SmaI-linearised pBKS2 plasmid (Stratagene Cloning System, CA). White colonies (11,500) were screened by hybridisation with double-stranded DNA probes containing dinucleotide repeats. Poly(dAdC), poly(dAdG), poly(dAdT) (Pharmacia Biotech, Sweden) were mixed at equimolar ratio and radiolabelled by [&amp;#61537;-32P] alpha dATP and dCTP using a random priming labelling kit (Life Technologies, Germany). Filter...
Tipo: Text
Palavras-chave: Crassostrea gigas; Oyster; Microsatellites.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-703.pdf

Impact of intensive larval rearing practices in oyster hatcheries : selective processes and loss of genetic variability (Poster)
Provedor de dados: 5
Autores: Taris, Nicolas; Sauvage, Christopher; Boudry, Pierre.
Early-life history of oysters, like in most marine bivalves, is characterized by high fecundity and low survival rate. In hatcheries, which are ecoming more and more important for the production of juveniles for aquaculture production, rearing conditions are optimised (density, feeding, temperature...), and contrast with those observed in the wild. Additionally, slow growing larvae are culled by sieving.
Tipo: Text
Palavras-chave: Crassostrea gigas; Juvenile; Genetic variability; Selection; Genetic; Hatcheries; Oyster.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/acte-3444.pdf

Réseau de suivi de la croissance de l'huître creuse en Bretagne. Synthèse des quatre années 1989 à 1992
Provedor de dados: 5
Autores: Littaye-mariette, Anne; Mazurie, Joseph.
Since 1989, an homogeneous Crassostrea gigas oyster stock has been distributed once a year on several rearing sites in Brittany (3 populations per site). The main quantitative and qualitative growth descriptors, which reflect water quality effects during the monitoring period, are estimated at the end of each year. The 1989-1992 analysis prompted us to describe various growth responses correlated to biotops: oyster production in open areas influenced by oceanic waters was fairly constant in quality, including size and Polydora sp. infestation. In contrast, oysters in estuarine areas, partly affected by eutrophication (e.g., Aber Benoît, Pen Bé), or with a low carrying capacity, were characterized by weight and Polydora sp. infestation heterogeneity. These...
Tipo: Text
Palavras-chave: Polydora; Condition Index; Mortality; Growth; Monitoring; Oyster; Crassostrea gigas; Brittany; Polydora; Indice de condition; Mortalité; Croissance; Réseau; Huître; Crassostrea gigas; Bretagne.
Ano: 1993
URL: http://archimer.ifremer.fr/doc/1993/rapport-1639.pdf

In-situ microcosms, a tool for assessment of pesticide impacts on oyster spat (Crassostrea gigas)
Provedor de dados: 5
Autores: Stachowski Haberkorn, S; Quiniou, Francoise; Nedelec, M; Robert, Rene; Limon, G; De La Broise, D.
Effects of the herbicide Basamais (bentazon) and the fungicide Opus (epoxiconazole) on oyster spat (Crassostrea gigas) were assessed using in-situ microcosms in a field experiment lasting 13 days. Six-week-old hatchery spat (mean size 1.1 mm), previously collected on PVC plates, was immersed in glass bottles filled with 200 mu m filtered seawater. Bottles were maintained underwater at 6 m depth and their water content changed every other day. Growth, measured as shell area index increase, was 126 +/- 4% in the control bottles. While no growth differences were observed between control and individual pesticide treatments at 10 mu g l(-1), oysters treated with a mix of 10 mu g l(-1) Opus and 10 mu g l(-1) Basamais showed a 50% growth reduction compared with...
Tipo: Text
Palavras-chave: Epoxiconazole; Bentazon; Pesticide; Toxicity; Oyster; Microcosm.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4134.pdf

Cellular and molecular hemocyte responses of the Pacific oyster, Crassostrea gigas, following bacterial infection with Vibrio aestuarianus strain 01/32
Provedor de dados: 5
Autores: Labreuche, Yannick; Lambert, Christophe; Soudant, Philippe; Boulo, Viviane; Huvet, Arnaud; Nicolas, Jean-louis.
The strategies used by bacterial pathogens to circumvent host defense mechanisms remain largely undefined in bivalve molluscs. In this study, we investigated experimentally the interactions between the Pacific oyster (Crassostrea gigas) immune system and Vibrio aestuarianus strain 01/32, a pathogenic bacterium originally isolated from moribund oysters. First, an antibiotic-resistant V. aestuarianus strain was used to demonstrate that only a limited number of bacterial cells was detected in the host circulatory system, suggesting that the bacteria may localize in some organs. Second, we examined the host defense responses to V. aestuarianus at the cellular and molecular levels, using flow-cytometry and real-time PCR techniques. We showed that hemocyte...
Tipo: Text
Palavras-chave: Crassostrea gigas; Oyster; Pathogenesis; Vibrio aestuarianus; Bivalve immunity.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-2182.pdf

Evidence of herpesvirus (OsHV-1) resistance in juvenile Crassostrea gigas selected for high resistance to the summer mortality phenomenon
Provedor de dados: 5
Autores: Degremont, Lionel.
During the MOREST project (2001–2006), oyster summer mortality was extensively investigated in Crassostrea gigas in France. However, significant increases in magnitude and geographic distribution of summer mortality episodes have been reported since 2008. This paper investigates the response to selection for survival, which was successfully performed between 2001 and 2003, in this new context. It also examines the relationship between the mortality and the three pathogens Vibrio aestuarianus, V. splendidus and the Ostreid herpesvirus 1 (OsHV-1). Three batches of juvenile (6-month-old) Crassostrea gigas were produced in February 2009 and tested in the field in the Marennes-Oléron Bay during summer (August and September) 2009: one control batch, one batch...
Tipo: Text
Palavras-chave: Summer mortality; Crassostrea gigas; Disease resistance; Ostreid herpesvirus; Vibrio sp; Oyster.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00033/14472/11770.pdf

Insights on the association between somatic aneuploidy and ostreid herpesvirus 1 detection in the oysters Crassostrea gigas, C. angulata and their F1 hybrids
Provedor de dados: 5
Autores: Batista, Frederico M.; Lopez-sanmartin, Monserrat; Boudry, Pierre; Navas, Jose I.; Ruano, Francisco; Renault, Tristan; Fonseca, Vera G.; Leitao, Alexandra.
Cytogenetic abnormalities associated with viral infections, including from viruses of the Herpesvirales order, have been reported in vertebrate species. Ostreid herpesvirus 1 (OsHV-1) has been detected worldwide during mortality outbreaks of the Pacific oyster Crassostrea gigas. On the other hand, a high proportion of aneuploid cells in somatic tissues have been observed in C. gigas. In this study, we analysed the putative association between aneuploidy levels and the detection of OsHV-1 in gills of C. gigas, the Portuguese oyster C. angulata and their F1 hybrids cultured in Ria Formosa (Portugal). OsHV-1 was detected by PCR in 5.4% of the total of oysters analysed (n = 111) namely in 11.1%, 8.0% and 1.7% of C. gigas, C. angulata and F1 hybrid...
Tipo: Text
Palavras-chave: Aneuploidy; Ostreid herpesvirus 1; Oyster; Crassostrea.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00215/32581/35759.pdf

Human and animal enteric caliciviruses in oysters from different coastal regions of the United States
Provedor de dados: 5
Autores: Costantini, V; Loisy, Fabienne; Joens, L; Le Guyader, Soizick; Saif, L.
Food-borne diseases are a major cause of morbidity and hospitalization worldwide. Enteric caliciviruses are capable of persisting in the environment and in the tissues of shellfish. Human noroviruses (HuNoVs) have been implicated in outbreaks linked to shellfish consumption. The genetic and antigenic relatedness between human and animal enteric calliciviruses suggests that interspecies transmission may occur. To determine the occurrence of human and animal enteric calliciviruses in United States market oysters, we surveyed regional markets. Oysters were collected from 45 bays along the United States coast during the summer and winter of 2002 and 2003. Samples were analyzed by reverse transcription-PCR, and results were confirmed by hybridization and...
Tipo: Text
Palavras-chave: Monitoring; Microbiology; Sampling; Oyster; Shellfish tissue; Human norovirus; Calicivirus.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1235.pdf

Vibrio aestuarianus zinc metalloprotease causes lethality in the Pacific oyster Crassostrea gigas and impairs the host cellular immune defenses
Provedor de dados: 5
Autores: Labreuche, Yannick; Le Roux, Frederique; Henry, Joel; Zatylny, Celine; Huvet, Arnaud; Lambert, Christophe; Soudant, Philippe; Mazel, Didier; Nicolas, Jean-louis.
Extracellular products (ECPs) of the pathogenic Vibrio aestuarianus 01/32 were previously reported to display lethality in Crassostrea gigas oysters and to cause morphological changes and immunosuppression in oyster hemocytes. To identify the source of this toxicity, biochemical and genetic approaches were developed. ECP protease activity and lethality were shown to be significantly reduced following incubation with metal chelators, suggesting the involvement of a zinc metalloprotease. An open reading frame of 1836 bp encoding a 611-aa metalloprotease (designated yam) was identified. The deduced protein sequence showed high homology to other Vibrio metalloproteases reported to be involved in pathogenicity. To further confirm the role of this enzyme in ECP...
Tipo: Text
Palavras-chave: Vibrio aestuarianus; Metalloprotease; Crassostrea gigas; Oyster; Hemocytes; Extracellular products.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00015/12649/9588.pdf

A Sustained Immune Response Supports Long-Term Antiviral Immune Priming in the Pacific Oyster,  Crassostrea gigas
Provedor de dados: 5
Autores: Lafont, Maxime; Vergnes, Agnes; Vidal-dupiol, Jeremie; De Lorgeril, Julien; Gueguen, Yannick; Haffner, Philippe; Petton, Bruno; Chaparro, Cristian; Barrachina, Celia; Destoumieux-garzon, Delphine; Mitta, Guillaume; Gourbal, Benjamin; Montagnani, Caroline.
Over the last decade, innate immune priming has been evidenced in many invertebrate phyla. If mechanistic models have been proposed, molecular studies aiming to substantiate these models have remained scarce. We reveal here the transcriptional signature associated with immune priming in the oyster Crassostrea gigas. Oysters were fully protected against Ostreid herpesvirus 1 (OsHV-1), a major oyster pathogen, after priming with poly(I·C), which mimics viral double-stranded RNA. Global analysis through RNA sequencing of oyster and viral genes after immune priming and viral infection revealed that poly(I·C) induces a strong antiviral response that impairs OsHV-1 replication. Protection is based on a sustained upregulation of immune genes, notably genes...
Tipo: Text
Palavras-chave: Innate immunity; Priming; OsHV-1; Antiviral response; Immune memory; Oyster; POMS; Poly(I·C); Interferon; Transcriptomic.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00614/72580/71541.pdf

Influence of one selected Tisochrysis lutea strain rich in lipids on Crassostrea gigas larval development and biochemical composition
Provedor de dados: 5
Autores: Da Costa, F.; Petton, Bruno; Mingant, Christian; Bougaran, Gael; Rouxel, Catherine; Quere, Claudie; Wikfors, G. H.; Soudant, P.; Robert, Rene.
Effects of a remarkably high overall lipid Tisochrysis lutea strain (T+) upon gross biochemical composition, fatty acid (FA), sterol and lipid class composition of Crassostrea gigas larvae were evaluated and compared with a normal strain of Tisochrysis lutea (T) and the diatom Chaetoceros neogracile (Cg). In a first experiment, the influence of different single diets (T, T+ and Cg) and a bispecific diet (TCg) was studied, whereas, effects of monospecific diets (T and T+) and bispecific diets (TCg and T+Cg) were evaluated in a second experiment. The strain T+ was very rich in triglycerides (TAG: 93–95% of total neutral lipids), saturated FA (45%), monounsaturated FA (31–33%) and total fatty acids (4.0–4.7 pg cell−1). Larval oyster survival and growth rate...
Tipo: Text
Palavras-chave: Larvae; Lipids; Oyster; Tisochrysis lutea.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00251/36258/36063.pdf

Hybridization and morphological differences between the two closely related oyster taxa Crassostrea angulata and C. gigas
Provedor de dados: 5
Autores: Batista, Frederico; Fonseca, Vera; Ben-hamadou, Radhouan; Taris, Nicolas; Henriques, Maria; Boudry, Pierre.
Unlike in some crops, no large heterotic effects have been observed in most farmed animals. Interestingly, significant hybrid vigour for some traits has been reported in the Pacific oyster, Crassostrea gigas. Crossbreeding between closely related taxa can be seen as an efficient way to exploit the dominance component of the genetic variance of a trait. Factorial crosses between the Portuguese oyster C. angulata (from Sado estuary, Portugal) and C. gigas (from Seudre estuary, France) were done to evaluate the aquaculture potential of hybrids. Juveniles of the different progenies were reared in Ria Formosa (Portugal) under usual farming conditions. The genetic confirmation of all progenies was done using mitochondrial and nuclear markers in order to detect...
Tipo: Text
Palavras-chave: Hybridization; Crassostrea angulata; Crassostrea gigas; Genetic; Oyster.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/acte-3429.pdf

Temperature and photoperiod drive Crassostrea gigas reproductive internal clock
Provedor de dados: 5
Autores: Fabioux, Caroline; Huvet, Arnaud; Le Souchu, Pierrick; Le Pennec, Marcel; Pouvreau, Stephane.
This study examined the gametogenic cycle of Crassostrea gigas in controlled conditions over one year, with a focus on the initiation of gametogenesis. This work analysed also the role of temperature and photoperiod in the regulation of oyster reproduction. Broodstock were maintained in natural (NC), accelerated (AC) and perpetual winter (WC) conditions of temperature and photoperiod, with feeding ad libitum. Qualitative and quantitative analyses of the reproductive pattern were performed using biometric measurement approach, sex ratio determination, histology and a gonad filling index. Each experimental treatment led to different strategies for growth and resource allocation. The gametogenic cycle, appeared entirely modulated, accelerated or delayed, by...
Tipo: Text
Palavras-chave: Temperature; Regulation; Gonad filling index; Gonial mitosis; Reproduction; Oyster.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-826.pdf

Detection of ostreid herpesvirus-1 (OsHV-1) by PCR using a rapid and simple method of DNA extraction from oyster larvae
Provedor de dados: 5
Autores: Batista, Frederico; Taris, Nicolas; Boudry, Pierre; Renault, Tristan.
A DNA extraction procedure was developed for the detection of ostreid herpesvirus-1 (OsHV-1) using the polymerase chain reaction (PCR) in oyster larvae. The DNA extraction procedure developed was tested on 8 larval samples. Abnormal nuclei with characteristic features associated with OsHV-1 infections were only observed in samples in which the viral DNA was detected by PCR. A previously described competitive PCR method was applied to detect inhibition during PCR reactions. The results show that the method can be used on small amounts of oyster larvae (3 mg) for the detection of OsHV-1 DNA by PCR.
Tipo: Text
Palavras-chave: DNA extraction; Detection; Larvae; Oyster; OsHV 1; Herpesvirus.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-2916.pdf

Ecophysiological and metabolic adaptations to sulphide exposure of the oyster Crassostrea gigas
Provedor de dados: 5
Autores: Le Moullac, Gilles; Cheize, Marie; Gastineau, Olivier; Daniel, Jean-yves; Le Coz, Jean-rene; Huvet, Arnaud; Moal, Jeanne; Pouvreau, Stephane; Van Wormhoudt, A; Samain, Jean-francois.
The purpose of this study is to examine the response of the oyster Crassostrea gigas to sulphide at different biological scales. A first experiment was designed to measure for 20 h the clearance (CR) and oxygen consumption (OC) rates of oysters exposed at different concentrations of sulphide (0, 3, 6, 12, 20, and 40 mu M). The second experiment was carried out to evaluate the metabolic adaptations to chronic sulphide exposure for 10 days by measuring PK and PEPCK enzyme activities, succinate and alanine content, the adenylate energy charge (AEC), and the activity of the electron transport system (ETS)in whole oysters at above 20 mu M. PK and PEPCK mRNAs and enzyme activities have been measured in adductor muscle. When exposed to sulphide above 20 mu M, CR...
Tipo: Text
Palavras-chave: ATP; AEC; Electron transport system; Succcinate; Alanine; Phosphoenolpyruvate carboxykinase; Pyruvate kinase; Oxygen consumption; Clearance rate; Crassostrea gigas; Sulphide; Oyster.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-3924.pdf

Les besoins écophysiologiques des larves d'huitres creuse Crassostrea gigas en conditions contrôlees : effet de la température, de la nourriture et modélisation de la croissance
Provedor de dados: 5
Autores: Rico Villa, Benjamin.
Nowadays, spat production of Pacific oyster Crassostrea gigas relies on rearing techniques under controlled conditions in hatchery. In this context, an extensive research in aquaculture is necessary because larval development and metamorphosis are critical for hatchery management. Firstly, a diet consisted in a Haptophyceae: Isochrysis affinis galbana (clone T-ISO) and a Bacillariophyceae: Chaetoceros calcitrans forma pumilum demonstrated its efficiency to supply the nutritional needs throughout the whole larval rearing. Then, a flow-through rearing system was developed and coupled with a continuous hydrobiological data recorder to provide basic information for ecophysiology research through different trophic levels and/or temperature throughout larval...
Tipo: Text
Palavras-chave: Crassostrea gigas; Larve; Huître; Croissance; Ecophysiologie; Microalgues; Température; Système d’élevage; Modélisation; Crassostrea gigas; Larvae; Oyster; Growth; Ecophysiology; Microalgae; Temperature; Rearing System; Modelling.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00012/12308/9102.pdf

Introduction into France of the Japanese oyster (Crassostrea gigas)
Provedor de dados: 5
Autores: Grizel, Henri; Heral, Maurice.
The Japanese oyster (Crassostrea gigas) has been introduced in France on a large scale to replace cultivation of the Portuguese oyster (Crassostrea angulata), affected by a viral disease. The importation took place from 1971 to 1975, with broodstock coming from British Columbia (Canada) and spat from Japan. Good growth rate and success of the natural setting on the French Atlantic coast attested to the success of this implantation, with a production which reached 80000 t by 1976. The precautionary measures associated with this transfer Iimited the implantation of an introduced fauna, 15 years after, to: Balanus amphitrite, Aiptasia pulchella and, on the Mediterranean coast, Undaria pinnatifida and Laminaria japonica. The authors also discuss the possible...
Tipo: Text
Palavras-chave: Crassostrea gigas; Oyster; Introduction; Crassostrea gigas; Huître; Introduction.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/publication-2760.PDF

Modelling the impact of a cultivated oyster population on the nitrogen dynamics: the Thau lagoon case (France)
Provedor de dados: 5
Autores: Bacher, Cedric; Bioteau, Hélène; Chapelle, Annie.
The Thau lagoon (France) is an important site for the cultivation of Crassastrea gigas. The relationship belween the oyster population and the environment was assessed through a model of trophic relationships. The results represent the initial step lowards a more precise assessment of the biological fluxes in the lagoon. This preliminary model was based on the nitrogen dynamics among the following compartments: phytoplankton, zooplankton. oysters. detritus and dissolved inorganic nitrogen in the water column. Two other compartments were also considered in the sediment: detritus and dissolved nitrogen. The model considered the watershed input and seawater exchange belween the lagoon and the open sea . The parameters were estimated from experiments on oyster...
Tipo: Text
Palavras-chave: Oyster; Crassostrea gigas; Nitrogen dynamics; Impact.
Ano: 1995
URL: http://archimer.ifremer.fr/doc/00039/15069/12403.pdf

Effects of Alexandrium minutum exposure on nutrition-related processes and reproductive output in oysters Crassostrea gigas
Provedor de dados: 5
Autores: Haberkorn, Hansy; Lambert, Christophe; Le Goic, Nelly; Moal, Jeanne; Suquet, Marc; Gueguen, Marielle; Sunila, Inke; Soudant, Philippe.
This study assessed the effects of an artificial bloom of the toxin-producing dinoflagellate, Alexandrium minutum, upon nutrition related processes and reproductive output of the Pacific oyster, Crassostrea gigas. Oysters were exposed to A. minutum, Paralytic Shellfish Toxins (PST) producer and compared to a control batch of oysters fed Isochrysis galbana clone Tahitian (T.Iso). The experiment was performed in June 2008, when oysters were found ripe. Several physiological variables of oysters, such as PSTs accumulation, digestive gland and histological observations as well as spermatozoa quality, were measured at the end of the exposure. Results indicate that the digestive gland was greatly impacted upon A. minutum exposure. Monoacylglycerol and...
Tipo: Text
Palavras-chave: Harmful algae; Alexandrium minutum; Oyster; Nutrition-related processes; Reproductive output.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00008/11927/8653.pdf

The oyster vasa-like gene: a specific marker of the germline in Crassostrea gigas
Provedor de dados: 5
Autores: Fabioux, Caroline; Pouvreau, Stephane; Leroux, Frederique; Huvet, Arnaud.
The vasa gene is,a key determinant for germline formation in eukaryotes. This gene, highly conserved through evolution, encodes a RNA helicase protein member of the DEAD-box family. To understand the germline formation in oyster, we report here the isolation and the characterization of a vasa orthologue in Crassostrea gigas (Oyvlg). OyVLG contained the eight consensus domains of the DEAD-box including those providing RNA unwinding activity. The expression pattern of Oyvlg was examined in adult oyster tissues at different reproductive stages. Its expression was restricted to germline cells both in males and females, including germinal stem cells and auxiliary cells. The expression of Oyvlg, strongest in early germ cells, decreased as the maturation...
Tipo: Text
Palavras-chave: RNA helicase; DEAD box; Vasa; Germline; Gametogenesis; Oyster.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-646.pdf

GigaTON: an extensive publicly searchable database providing a new reference transcriptome in the pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: Riviere, Guillaume; Klopp, Christophe; Ibouniyamine, Nabihoudine; Huvet, Arnaud; Boudry, Pierre; Favrel, Pascal.
Background: The Pacific oyster, Crassostrea gigas, is one of the most important aquaculture shellfish resources worldwide. Important efforts have been undertaken towards a better knowledge of its genome and transcriptome, which makes now C. gigas becoming a model organism among lophotrochozoans, the under-described sister clade of ecdysozoans within protostomes. These massive sequencing efforts offer the opportunity to assemble gene expression data and make such resource accessible and exploitable for the scientific community. Therefore, we undertook this assembly into an up-to-date publicly available transcriptome database: the GigaTON (Gigas TranscriptOme pipeliNe) database. Description: We assembled 2204 million sequences obtained from 114 publicly...
Tipo: Text
Palavras-chave: Oyster; Transcriptome; Development; Stress; Tissues; NGS.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00302/41321/40520.pdf

Etude et modélisation de la dynamique des populations de bivalves en élevage (Crassostrea gigas et Mytilus galloprovincialis) dans le bassin de Thau (Méditerranée, France) et des ascidies solitaires associées
Provedor de dados: 5
Autores: Gangnery, Aline.
The total standing stock of bivalves cultured in Thau Lagoon (France) that is mainly constituted of the Pacific oyster, Crassostrea gigas, and the Mediterranean mussel, Mytilus galloprovincialis, vary between 14,000 and 20,000 tons within a year. These variations were attributed to the rearing cycle of molluscs in the lagoon but also to their growth performances. Oysters cultured in the Thau Lagoon presented the best growth rate ever reported whereas trophic conditions are low : mean concentrations in organic particulate matter and total chlorophyll a averaged 1 mg.l-1 and 1.2 µg.l-1, respectively. The development of a growth model shows that temporal pattern (i.e. seasonality) of bivalve growth is explained by water temperature and spatial pattern is...
Tipo: Text
Palavras-chave: Lagoon ecosystem; Resource management; Rearing strategies; Production; Standing stock; Hydrobiology; Growth; Shellfish culture; Ascidiella aspersa; Mussel; Oyster; Ecosystème lagunaire; Gestion des ressources; Stratégies d'élevage; Production; Stock; Hydrobiologie; Croissance; Conchyliculture; Ascidiella aspersa; Moule; Huître.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/these-102.pdf

Detection and description of a particular Ostreid herpesvirus 1 genotype associated with massive mortality outbreaks of Pacific oysters, Crassostrea gigas, in France in 2008
Provedor de dados: 5
Autores: Segarra, Amelie; Pepin, Jean-francois; Arzul, Isabelle; Morga, Benjamin; Faury, Nicole; Renault, Tristan.
Ostreid herpesvirus 1 (OsHV-1) infections have been reported around the world and are associated with high mortalities of the Pacific oyster (Crassostrea gigas). In the summer 2008, abnormal mortality rates ranging from 80% to 100% were reported in France and affected only Pacific oysters. Analyses of oyster samples collected during mortality outbreaks demonstrated a significant detection of OsHV-1 (75% of analysed batches), which appeared stronger than previous years. DNA sequencing based on C and IA regions was carried out on 28 batches of OsHV-1 infected Pacific oysters collected in 2008. Polymorphisms were described in both the C and IA regions and characterized a genotype of OsHV-1 not already reported and termed OsHV-1 μVar. A microsatellite zone...
Tipo: Text
Palavras-chave: Herpes virus; Oyster; Crassostrea gigas; OsHV-1 mu Var; Increased mortality; Microsatellites.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00011/12260/9035.pdf

Experimental evidence for a genetic basis to differences in aneuploidy in the Pacific oyster (Crassostrea gigas)
Provedor de dados: 5
Autores: Leitao, Alexandra; Boudry, Pierre; Mccombie, Helen; Gerard, Andre; Thiriot-quievreux, Catherine.
Aneuploidy has been previously reported in wild and cultivated Pacific oysters, Crassostrea gigas, and has been shown to be negatively correlated with growth. This is especially important since high variability of growth rate is one of the major problems in the aquacultural production of this species. The existence of a genetic basis for the observed differences in aneuploidy was first investigated through the comparative study of six full-sib families, with mean individual weights ranging from 0.59 to 1.49 g. The slowest growing family was found to have the highest level of aneuploidy. Significant differences in aneuploidy were also found among families when individuals with the same growth rate were sampled. This supports the hypothesis of the existence...
Tipo: Text
Palavras-chave: Oyster; Growth; Genetics; Full sib families; Crassostrea gigas; Aneuploidy; Huître; Croissance; Génétique; Famille de plein frères; Crassostrea gigas; Aneuploïdie.
Ano: 2001
URL: https://archimer.ifremer.fr/doc/2001/publication-2700.pdf

Genotoxicity of diuron and glyphosate in oyster spermatozoa and embryos
Provedor de dados: 5
Autores: Akcha, Farida; Spagnol, Charlene; Rouxel, Julien.
We investigated the effects of genotoxicant exposure in gametes and embryos to find a possible link between genotoxicity and reproduction/developmental impairment, and explore the impact of chemical genotoxicity on population dynamics. Our study focused on the genotoxic effects of two herbicides on oyster gametes and embryos: glyphosate (both as an active substance and in the Roundup formulation) and diuron. France is Europe's leading consumer of agrochemical substances and as such, contamination of France's coastal waters by pesticides is a major concern. Glyphosate and diuron are among the most frequently detected herbicides in oyster production areas; as oyster is a specie with external reproduction, its gametes and embryos are in direct contact with...
Tipo: Text
Palavras-chave: Genotoxicity; Embryotoxicity; Oyster; Gametes; Pesticides; Diuron; Glyphosate.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00070/18128/15783.pdf

Flow cytometry to measure impact of temperature and salinity on the survival of Bonamia ostreae, parasite infecting flat oyster Ostrea edulis, in seawater
Provedor de dados: 5
Autores: Arzul, Isabelle; Bond, Celine; Gagnaire, Beatrice; Morga, Benjamin; Chollet, Bruno; Ferrand, Sylvie; Robert, Maeva; Renault, Tristan.
Bonamiosis due to the intrahaemocytic protistan parasite Bonamia ostreae is a European endemic disease affecting the flat oyster, Ostrea edulis. After its first description in June 1979&amp;#305; in Brittany, the parasite rapidly spread to all French oyster farming areas and in other European countries through transfers of live molluscs. The parasite has been described in different ecosystems from estuaries to open sea and no clear correlations could he demonstrated between the disease development and environmental parameters like temperature or salinity. The infection can he directly transmitted by cohabitation between infected and non infected oysters. Nevertheless, the parasite life cycle, including its survival outside the host, is not completely...
Tipo: Text
Palavras-chave: Impact; Salinity; Temperature; Flow cytometry; Bonamia ostreae; Parasite; Ostrea edulis; Oyster.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3372.pdf

Ecophysiologie de la maturation sexuelle et de la ponte de l'huître creuse Crassostrea gigas : réponses métaboliques (respiration) et alimentaires (filtration, absorption) en fonction des différents stades de maturation
Provedor de dados: 5
Autores: Soletchnik, Patrick; Razet, Daniel; Geairon, Philippe; Faury, Nicole; Goulletquer, Philippe.
The study of maturation and spawning of the oyster is part of a research program to investigate the summer mortalities of the oysters, Crassostrea gigas in Marennes-Oléron Bay. Four maturity stages were simultaneously obtained by diet and thermal conditioning (immature, low maturation, mature and post-spawning stages). Measurements of clearance, filtration, absorption and respiration rates allowed a calculation of the scope for growth and hence an estimation of the oyster's energetic budget at various maturity stages. Male and female oysters had similar physiological responses. The filtration rate ranged from 2.4 to 2.6 1.h(-1) at the early stages of maturation and decreased to 1.8 1.h.' during the maturity stage. Growth rate resulting from gonad...
Tipo: Text
Palavras-chave: Huître; Crassostrea gigas; Conditionnement; Maturation; Filtration; Absorption; Respiration; Oyster; Crassostrea gigas; Conditioning; Maturation; Filtration; Absorption and respiration rates.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/1997/publication-3090.pdf

Etude de la structure des communautés bactériennes du sédiment et de l'écologie de Vibrio aestuarianus pathogène de l'huître creuse Crassostrea gigas dans deux sites ostréicoles
Provedor de dados: 5
Autores: Azandegbe, Afi.
Since several years, the French oyster farming copes with high mortality affecting juveniles and some adults of the Pacific oyster Crassostrea gigas. Studies conducted in the framework of a multidisciplinary project (MOREST) showed that mortality was related to several factors like physiological and genetic status of oyster, pathogens including bacteria of the genus Vibrio, and revealed that the sediment, on which the oyster cages are installed, might play a particular role. This has been suggested because of the concomitance of the mortalities and increased toxic compounds like ammonia and sulphides in the sediment. Moreover, the presence of Vibrio bacteria in the sediment indicates a dual role of sediment in the mortality onset. The physico-chemical...
Tipo: Text
Palavras-chave: Huître; Crassostrea gigas; Bactéries; Vibrio aestuarianus; Écologie; Sédiment; Ammonium; Sulfures; Oyster; Crassostrea gigas; Bacteria; Vibrio aestuarianus; Ecology; Sediment; Ammonia; Sulphide.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00032/14277/11561.pdf

Product differentiation and quality approach in the French market for oysters and mussels.
Provedor de dados: 5
Autores: Charles, Erwan; Paquotte, Philippe.
France is one of the world top producers of oysters and mussels by aquaculture with 140 000 tonnes of oysters, 60 000 tonnes of mussels and an ex-farm turnover accounting to 350 millions US$ in 1996. The French market is by far the largest one in Europe for oyster and is supplied entirely by domestic production, with very little external trade. On the contrary, the French market for mussel is a very competitive one, widely open to imports. Given the evolution of market conditions due to the development of supermarkets, to the competition of new value added products and to the modification of consumer's habits, the French oyster and mussel producers have started to implement various strategies of product differentiation and of quality approach. These...
Tipo: Text
Palavras-chave: Seafood market study; Product differentiation; Quality; Oyster; Aquaculture; SEM.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/1998/acte-2523.pdf

Oyster reproduction is affected by exposure to polystyrene microplastics
Provedor de dados: 5
Autores: Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goic, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-pont, Ika; Soudant, Philippe; Huvet, Arnaud.
Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L−1) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS...
Tipo: Text
Palavras-chave: Microplastic; Reproduction; Energy allocation; Oyster.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00311/42233/41600.pdf

Epidémiologie de Bonamia ostreae et Marteilia refringens en Bretagne en 1984 et 1985 : situation et évolution
Provedor de dados: 5
Autores: Tige, Gilbert; De Kergariou, Gabriel; Cochennec, Nathalie; Rabouin, Marie-agnès.
A systematic surveillance progam conducted since 1980 along the coasts of Britanny has followed the evolution and epidemiological state of the natural O. eulis oyster beds and seed areas in the intertidal zones and deep water. Presently, Marteilia refringens exists endemically in Brittany estuaries ; the rate and degree of infestation varies from year to year depending on the hydrological conditions and the geographical region. In no case, however, is the return of flat oyster culture envisoned. Bonamia ostreae is present not only in the estuaries but also in the deep-water rearing areas (Baie de Quiberon, Cancale, Baie de St Brieuc). The infestation increases with age, but also depends on the quantity of the stock and the culture practises. In particular,...
Tipo: Text
Palavras-chave: Huître plate; Ostrea edulis; Maladie; Bonamia ostreae; Marteilia refringens; Bretagne; Oyster; Ostrea edulis; Diseases; Bonamia ostreae; Marteilia refringens.
Ano: 1986
URL: http://archimer.ifremer.fr/doc/00022/13299/10353.pdf

Understanding the dynamics of δ13C and δ15N in soft tissues of the bivalve Crassostrea gigas facing environmental fluctuations in the context of Dynamic Energy Budgets (DEB)
Provedor de dados: 5
Autores: Emmery, Antoine; Lefebvre, Sebastien; Alunno-bruscia, Marianne; Kooijman, S. A. L. M.
We studied the dynamics of stable isotopes δ13C and δ15N of an opportunistic suspension feeder the Pacific oyster (Crassostrea gigas) to better understand the factors that influence the trophic enrichment (trophic-shift, Δ) between primary producers and consumers. Most of the previous studies on this topic do not quantify mass fluxes or isotopic discrimination phenomena in the organism, which are two pillars in isotope ecology. We used a dynamic energy budget (DEB) approach (Kooijman, 2010) to quantify i) the fluxes of elements and isotopes in C. gigas soft tissues and ii) the impact of the scaled feeding level, the organism mass and the isotopic ratio of food on the "trophic-shift" Δ, and isotope turnover in tissues. Calibration and parametrization...
Tipo: Text
Palavras-chave: Oyster; Isotopic ratio; Discrimination; Trophic-shift; Diet; DEB theory.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00043/15434/12784.pdf

Experimental and natural cathodoluminescence in the shell of Crassostrea gigas from Thau lagoon (France): ecological and environmental implications
Provedor de dados: 5
Autores: Langlet, D; Alunno-bruscia, Marianne; Rafelis, M; Renard, M; Roux, M; Schein, E; Buestel, Dominique.
We present a cathodoluminescence (CL) study of growth layer deposition in the shell of the oyster Crassostrea gigas. CL is based on the physical properties of lattice-bound manganese (Mn2+), which is the main activator in calcium carbonate. Our study involved chemical marking by immersing individuals in seawater to which manganese chloride had been added, and subsequent reading of the shell with CL microscopy coupled with numeric treatment of microphotographs; CL emission was analyzed using a scanning electron microscope coupled to a spectrometer. Since the marking did not harm the oysters, repeated markings were possible, allowing validation of the inferences made from analysis of the shell rings. Oysters reared in a French Mediterranean lagoon (Thau...
Tipo: Text
Palavras-chave: Mediterranean lagoon; Manganese marking; Carbonate biomineraliation; Shell growth; Cathodoluminescence; Oyster.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1979.pdf

Development of SNPs and their use for the identification of summer mortality resistance QTLs in the Pacific oyster (Crassotrea gigas)
Provedor de dados: 5
Autores: Sauvage, Christopher; Lapegue, Sylvie; Bierne, Nicolas; Boudry, Pierre.
Summer mortalities of the Pacific cupped oyster Crassostrea gigas have been described in the literature for decades. One solution to overcome this problem would be to select animals more tolerant to summer mortalities, as this trait was shown to be highly heritable (Degrémont, 2003). The identification of markers associated to the resistance would allow to better understand this complex phenomenon and, eventually to establish markers assisted selection. Recently, two moderately dense genetic linkage maps have been established in the Pacific oyster based on microsatellites and AFLP markers (Hubert and Hedgecock, 2004; Li and Guo, 2004). In this context, the development and mapping of SNPs will increase the density of the linkage map and consequently the...
Tipo: Text
Palavras-chave: QTLs analyses; Summer mortaliy; Genetic; SNPs; Crassostrea gigas; Oyster.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/acte-3351.pdf

Déterminismes génétiques de l'allocation à la reproduction chez les huîtres creuses (Crassostrea gigas) triploïdes
Provedor de dados: 5
Autores: Normand, Julien.
In diploid Pacific oyster Crassostrea gigas, gonadic development can be important in terms of energetic investment. Phenotypic and genetic negative correlations have also been observed between gonadic occupation and traits related to survival and growth, and this fact suggests that this trait could be deleterious for its aquaculture production. Triploidy can be been artificially induced to improve the production of Pacific oysters as it results in a general diminution of mean gonadic development. This trait is however highly variable. In this context, this study aimed to quantify and qualify the allocation to reproduction in triploid oysters and to study its genetic bases. Variability for allocation to reproduction and growth was first studied in 3 sets of...
Tipo: Text
Palavras-chave: Triploidy x genetic interaction; Genetic determinism; Sexual dimorphism; Gametogenesis; Allocation to reproduction; Triploid; Oyster; Interaction triploïdie x génétique; Déterminisme génétique; Dimorphisme sexuel; Gamétogenèse; Allocation à la reproduction; Triploïde; Huître.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/these-6971.PDF

Etudes sur la pathologie des huîtres
Provedor de dados: 5
Autores: Balouet, G.
French summary: In 1974, at the request of a group of oyster farmers in the Brittany region, the Pathology Laboratory of the U.E.R. Medicine of Brest undertook a series of theoretical and applied research projects concerning the problem of flat oyster digestive gland disease, due to Marteilia refringens, the primary economic problem of that time.  In 1978, in the research report of Contract C.N.E.X.O. 77/1690, the main results obtained since the beginning of the study of the parasitosis were made public. The present report has as its objective to show: - The results obtained in 1978-1979 while monitoring the parasitosis, and most especially the epidemiological evolution of the disease; - Information concerning the presence of other infectious diseases...
Tipo: Text
Palavras-chave: Parasite; Ostrea edulis; Oyster; Pathology.
Ano: 1978
URL: http://archimer.ifremer.fr/doc/1978/rapport-1927.pdf

Reproductive effort and growth in Crassostrea gigas: comparison of young diploid and triploid oysters issued from natural crosses or chemical induction
Provedor de dados: 5
Autores: Normand, Julien; Ernande, Bruno; Haure, Joel; Mccombie, Helen; Boudry, Pierre.
Early reproductive effort and growth were measured in 3 groups of the Pacific oyster Crassostrea gigas: 1 diploid group and 2 triploid groups resulting from either chemical induction (3nCB) or crosses between tetraploid and diploid parents (3nDT). Oysters were reared under intensive nursery conditions and sampled when 5 mo old. Reproductive effort was estimated by cross-sectional area measurements of the visceral mass (i.e. gonadic occupation) and maturation stage was assessed by qualitative histology. As expected, comparison of the reproductive patterns of these 3 groups revealed a lower reproductive effort in triploid individuals relative to diploid. However, gonadic occupation in triploid oysters was higher than expected in both 3nCB and 3nDT groups, as...
Tipo: Text
Palavras-chave: Triploidy; Oyster; Gametogenesis; Crassostrea gigas.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6978.pdf

Crassostrea gigas ferritin: cDNA sequence analysis for two heavy chain type subunits and protein purification
Provedor de dados: 5
Autores: Durand, Jean-pierre; Goudard, Françoise; Pieri, Jacques; Escoubas, Jean-michel; Schreiber, Nathalie; Cadoret, Jean-paul.
Ferritin has been shown as being the principal iron storage in the majority of living organisms. In marine species, ferritin is also involved in high-level accumulation of Po-210. As part of our work on the investigation of these radionuclides' concentration in natural environment, ferritin was searched at the gene and protein level. Ferritin was purified from the visceral mass of the oyster Crassostrea gigas by ion-exchange chromatography and HPLC. SDS-PAGE revealed one band of 20 kDa. An Expressed Sequence Tag (EST) library was screened and led to the identification of two complementary DNA (cDNA) involved in ferritin subunit expression. The complete coding sequences and the untranslated regions (UTRs) of the two genes were obtained and a 5' Rapid...
Tipo: Text
Palavras-chave: Iron; IRE; EST; Oyster.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-693.pdf

Mitochondrial and nuclear DNA phylogeography of  two cupped oysters Crassostrea gigas and Crassostrea angulata
Provedor de dados: 5
Autores: Boudry, Pierre; Huvet, Arnaud.
The taxonomic status of Crassostrea angulata and Crassostrea gigas has long been a matter of controversy. Morphological and physiological similarities, as well as homogeneity in allelic frequencies on allozymes between the populations of the two taxa, lead most authors to suggest to regroup of the two within the same species. European and Asian populations of C. gigas and C. angulata have been studied using microsatellite and mitochondrial DNA markers. The analysis of genetic distances and the distribution of allelic and haplotype frequencies revealed a differentiation between the populations of C. gigas and C. angulata. The data allowed the construction of Neighbor-joining trees for each of the two types of markers. Similar topologies appeared with data...
Tipo: Text
Palavras-chave: Mitochondrial DNA; Nuclear DNA; Phylogeography; Crassostrea angulata; Crassostrea gigas; Genetic; Oyster.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/1999/acte-3434.pdf

Perception of oyster-based products by French consumers: the effect of processing and role of social representations
Provedor de dados: 5
Autores: Debucquet, Gervaise; Cornet, Josiane; Adam, Isabelle; Cardinal, Mireille.
The search for new markets in the seafood sector, associated with the question of the continuity of raw oyster consumption over generations can be an opportunity for processors to extend their ranges with oyster-based products. The twofold aim of this study was to evaluate the impact of processing and social representation on perception of oyster-based products by French consumers and to identify the best means of development in order to avoid possible failure in the market. Five products with different degrees of processing (cooked oysters in a half-shell, hot preparation for toast, potted oyster, oyster butter and oyster-based soup) were presented within focus groups and consumer tests, at home and in canteens with the staff of several companies in order...
Tipo: Text
Palavras-chave: Oyster; Processing; Consumer perception; Disgust; Social representation.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00098/20945/18603.pdf

Tissue expression of two alpha-amylase genes in the Pacific oyster Crassostrea gigas. Effects of two different food rations
Provedor de dados: 5
Autores: Huvet, Arnaud; Daniel, Jean-yves; Quere, Claudie; Dubois, Solene; Prudence, Marie; Van Wormhoudt, A; Sellos, D; Samain, Jean-francois; Moal, Jeanne.
A semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay was developed to estimate tissue-specific expression of two amylase genes in five different tissues of the Pacific oyster Crassostrea gigas and the experimental effects of food level on the cellular, enzymatic and gene expression changes of the digestive gland. Results indicated that both genes were transcribed at different levels depending on tissue type. A strong preferential expression of both amylase genes was observed in the digestive gland leading to high amylase activities, in accordance with the digestive function of this organ. Traces of gene expression and activity were observed in other analysed tissues. These appeared higher in labial palps than in other...
Tipo: Text
Palavras-chave: Oyster; Gene expression; Food regulation; Digestive enzyme activity; Alpha amylase.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/publication-394.pdf

Contribution à l'étude de l'ontogenèse du système immunitaire chez l'huître creuse Crassostrea gigas
Provedor de dados: 5
Autores: Tirape Bajana, Ana.
The interest for the understanding of the immune mechanisms in the oyster, Crassotrea gigas has been considerably increased these last years, mainly because of economie losses due to diseases which affected the continuity of this species. The studies of these mechanisms contributes to a better understanding of the differential susceptibilities observed in this species against various pathogens. In the present study, our  goal was to define the ontogenesis of immune system in C. gigas during the development, by functional genomic approaches. The studies have been focalized on the analyses of expression and localization of effectors previously identified in adult oysters as implicated in immunity. We have shown, in particular, that hemocytes appear in the...
Tipo: Text
Palavras-chave: Invertébré; Mollusque bivalve; Huître; Cra; Immunité; Hémocytes; Hématopoïèse; Développement; Ontogenèse; Expression des gènes; Q-PCR; SSH; Invertebrate; Bivalve Mollusk; Oyster; Crassostrea gigas; Immunity; Hemocytes; Hematopoiesis; Development; Ontogenesis; Gene expression; Q-PCR; SSH.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/00440/55113/56565.pdf

Nickel and vanadium contamination of benthic invertebrates following the "Erika" wreck
Provedor de dados: 5
Autores: Chiffoleau, Jean-francois; Chauvaud, Laurent; Amouroux, David; Barats, Aurélie; Dufour, Aurélie; Pecheyran, Christophe; Roux, Nathalie.
Levels of nickel and vanadium, trace metals found in high concentration in the oil spilled from the "Erika" tanker off Brittany (France) in December 1999 (41 +/- 1 and 87 +/- 3 mg kg(-1) respectively), have been monitored over a one-year period following this accidental event in several benthic invertebrates. Ni and V in mussels (Mytilus edulis) and oysters (Crassostrea gigas) soft tissues were analysed twice a month by graphite furnace atomic absorption spectrometry and a scallop (Pecten maximus) shell daily growth bands were sampled every three bands by laser ablation and analysed by ICP-MS for these two contaminants. Survey data for mollusc tissues were compared with reference data arising from the national monitoring database. Ni concentrations in...
Tipo: Text
Palavras-chave: Monitoring; Scallop shell; Oyster; Mussel; Vanadium; Nickel; Oil spill.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-402.pdf

Sensitivity of eastern oyster ( Crassostrea virginica) spermatozoa and oocytes to dispersed oil: Cellular responses and impacts on fertilization and embryogenesis
Provedor de dados: 5
Autores: Vignier, J.; Volety, A. K.; Rolton, A.; Le Goic, N.; Chu, F. -l. E.; Robert, Rene; Soudant, P.
The 2010 Deepwater Horizon (DWH) oil spill released millions of barrels of oil and dispersant into the Gulf of Mexico. The timing of the spill coincided with the spawning season of Crassostrea virginica. Consequently, gametes released in the water were likely exposed to oil and dispersant. This study aimed to (i) evaluate the cellular effects of acute exposure of spermatozoa and oocytes to surface slick oil, dispersed mechanically (HEWAF) and chemically (CEWAF), using flow-cytometric (FCM) analyses, and (ii) determine whether the observed cellular effects relate to impairments of fertilization and embryogenesis of gametes exposed to the same concentrations of CEWAF and HEWAF. Following a 30-min exposure, the number of spermatozoa and their viability were...
Tipo: Text
Palavras-chave: Deepwater Horizon oil spill; Oyster; Spermatozoa; Oocyte; Flow-cytometry.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00377/48851/51168.pdf

First results of an epidemiological study on oyster (Crassostrea gigas) mortality events in France during summer 2008
Provedor de dados: 5
Autores: Miossec, Laurence; Allain, Gwenhael; Arzul, Isabelle; Francois, Cyrille; Garcia, Celine; Cameron, Angus.
Abnormal mortalities occurred in most oyster producing areas in France during the summer of 2008.  The mortalities were sudden and severe (up to 100%) and mainly affected 6 to 18 month old juveniles.  Only Crassostrea gigas species was affected.  The cause of the mortality was unclear but OsHV-1 virus and bacteria belonging to Vibrionaceae family were frequently detected in affected populations. An epidemiological study was commenced in autumn 2008 in order to identify factors associated with, and the cause (or causes) of these mortalities.  This paper presents the results of the first (descriptive) part of this investigation.  The objectives were to identify the affected population and to describe the pattern of mortalities in time and space.  Mortality...
Tipo: Text
Palavras-chave: France; Crassostrea gigas; Oyster; Mortality; Epidemological study.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/acte-6772.pdf

Delivery of riboflavin to larval and adult pacific oysters, Crassostrea gigas Thunberg by lipid spray beads
Provedor de dados: 5
Autores: Langdon, Cj; Seguineau, Catherine; Ponce, B; Moal, Jeanne; Samain, Jean-francois.
Lipid spray beads (SB) were prepared containing 13% w/w particulate riboflavin. Beads suspended in seawater lost 73% riboflavin after 24 h. Release of riboflavin from SE ingested by Pacific oyster (Crassostrea gigas) larvae was observed under epifluorescent light. Riboflavin concentrations in tissues of adult oysters fed on riboflavin-SB were significantly (SNK, P &lt; 0.05) greater than those of oysters fed on seawater-filled SE. Concentrations of riboflavin in oysters exposed to dissolved riboflavin were not significantly greater than those of oysters fed on seawater-filled SE: indicating that elevated riboflavin concentrations in oysters fed on riboflavin-SB were attributable to breakdown of ingested beads rather than uptake of dissolved riboflavin...
Tipo: Text
Palavras-chave: Spray beads; Lipid; Riboflavin; Oyster; Larvae; Crassostrea gigas.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00000/10493/9511.pdf

Recherche d'AND d'herpèsvirus infectant les bivalves dans des échantillons d'eau de claires ostréicoles
Provedor de dados: 5
Autores: Solliec, Gaëlle; Vigneron, Valérie; Montanie, Hélène; Renault, Tristan.
Viral particles, associated with high mortality rates, have been reported among larvae and juveniles in different marine bivalve specie and characterized as member of the Hespesviridae family. Most studies focused on the detection of such viral infections among economically important species. However, the persistence of bivalve herpes viruses in marine environment is poorly documented. This topic appears as an important research domain in order to clarify the natural infection cycle of the herpesvirus of marine bivalves.
Tipo: Text
Palavras-chave: Herpesviridae; Oyster; PCR; DNA; Herpesvirus; Huître; PCR; ADN.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/acte-2856.pdf

Molecular cloning and seasonal expression of oyster glycogen phosphorylase and glycogen synthase genes
Provedor de dados: 5
Autores: Bacca, Helene; Huvet, Arnaud; Fabioux, Caroline; Daniel, Jean-yves; Delaporte, Maryse; Pouvreau, Stephane; Van Wormhoudt, A; Moal, Jeanne.
To investigate the control at the mRNA level of glycogen metabolism in the cupped oyster Crassostrea gigas, we report in the present paper the cloning and characterization of glycogen phosphorylase and synthase cDNAs (Cg-GPH and Cg-GYS, respectively, transcripts of main enzymes for glycogen use and storage), and their first expression profiles depending on oyster tissues and seasons. A strong expression of both genes was observed in the labial palps and the gonad in accordance with specific cells located in both tissues and ability to store glucose. Cg-GPH expression was also found mainly in muscle suggesting ability to use glycogen as readily available glucose to. supply its activity. For seasonal examinations, expression of Cg-GYS and Cg-GPH genes...
Tipo: Text
Palavras-chave: Reproduction; Regulation; Oyster; Glycogen; Expression; Gene; Energy; Crassostrea gigas; Bivalve.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-435.pdf

Chromosome loss in tetraploid families of the Pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: Mccombie, Helen; Lapegue, Sylvie; Cornette, Florence; Ledu, Christophe; Boudry, Pierre.
Alterations of  chromosome number have been observed in the somatic tissue of  Crassostrea gigas diploids and artificial polyploids bred in this species.   Tetraploid animals with lower chromosome counts in some or all of their somatic tissue are considered undesirable as parents either for commercial triploids (produced via a  cross with diploids) or for tetraploid breeding because (1) they may confer the tendency to lose chromosomes and revert to lower ploidy levels to their offspring or (2) their offspring could have a lower ploidy directly because of potential links between somatic and gametic chromosome loss.  The present study evaluated the phenomenon in bi-parental tetraploid families bred from parents of differing ploidy quality, including a...
Tipo: Text
Palavras-chave: Tetraploid; Chromosome; Genetic; Crassostrea gigas; Oyster.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/acte-3435.pdf

Diagnostic moléculaire de l'origine des contaminations fécales dans l'environnement littoral - Développement de marqueurs Bacteroidales spécifiques de l'hôte
Provedor de dados: 5
Autores: Mieszkin, Sophie.
Human and animal faecal pollution affects environmental water in inland and coastal areas, with negative implications for recreational uses, public safety and shellfish sanitary status due to the presence of enteric pathogens. Starting from 2011, the revised Bathing Water European Directive (2006/7/CE) requires the establishment of bathing water profiles with an inventory and study of the pollution sources likely to affect water quality. The faecal microbiological indicators used in these regulations, Escherichia coli and enteroccoci, cannot distinguish between human and animal faecal contamination. Thus, alternative methods, that focus on target microorganisms such as bacteria belonging to the Bacteroidales order were developed or are being developed to...
Tipo: Text
Palavras-chave: Contaminations fécales humaines; Porcines et ruminants; Bacteroidales; Gènes codant les ARNr 16S; PCR quantitative en temps réel; Eaux; Persistance; Huîtres; Human; Porcine and ruminant faecal contaminations; Bacteroidales; 16S rRNA genes; Quantitative real-time PCR; Water; Persistence; Oyster.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00021/13206/10258.pdf

Genetic improvement for disease resistance in oysters: a review
Provedor de dados: 5
Autores: Degremont, Lionel; Garcia, Celine; Allen, Standish K., Jr.
Oyster species suffer from numerous disease outbreaks, often causing high mortality. Because the environment cannot be controlled, genetic improvement for disease resistance to pathogens is an attractive option to reduce their impact on oyster production. We review the literature on selective breeding programs for disease resistance in oyster species, and the impact of triploidy on such resistance. Significant response to selection to improve disease resistance was observed in all studies after two to four generations of selection for Haplosporidium nelsoni and Roseovarius crassostrea in Crassostrea virginica, OsHV-1 in Crassostrea gigas, and Martelia sydneyi in Saccostrea glomerata. Clearly, resistance in these cases was heritable, but most of the studies...
Tipo: Text
Palavras-chave: Disease resistance; Oyster; Selection; Pathogen; Genetic; Mortality.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00269/38049/36139.pdf

Studies of a European shellfish disease: Bonamia ostreae parasite of the flat oyster Ostrea edulis ; control and treatment. Final Report
Provedor de dados: 5
Autores: Bachere, Evelyne; Ifremer, Unité de Pathologie, Immunologie et Génétique Moléculaire des Invertébrés Marins, F-17390 La Tremblade, France; CEV, Centro Experimental de Vilaxoan, Conselleria de Pesca, Villagarcia de Arosa, Spain; CSIC, Consejo Superior Investigaciones Cientificas, Peira de Bouzas S/N, Avda E. Cabello 636208, Vigo, Spain; UCC, University College Cork, Dept of Zoology Cork, Ireland; FCR, Fisheries Research Center, Abbotstown, Castleknock, Dublin 15, Ireland; US, University of Southampton, Dept of Oceanography Southampton S09 5NH, United Kingdom.
Bonamia ostreae, an intrahemocytic protozoan parasite infecting the oyster Ostrea edulis, is responsible for an endemic disease affecting all intensive breeding areas of European countries. Epidemiological studies showed variable prevalences, 43% in Galicia (Spain), from 6% to 32% in France and 45% in the most important area of Ireland. The impact of oyster transfers, handlings, high densities have been implicated in the disease development but environmental stressors could be more involved than zootechnical methods. The effect of water temperature, salinity and tidal exposure were particulary examined to assess stress induced changes and determine physiological, biochemical and immunological state indices of oyster populations, which will contribute to...
Tipo: Text
Palavras-chave: Disease; Oyster; Ostrea edulis; Parasitology; Bonamia ostreae; Epidemiology.
Ano: 1990
URL: http://archimer.ifremer.fr/doc/00273/38383/36713.pdf

Copper induces expression and methylation changes of early development genes in Crassostrea gigas embryos
Provedor de dados: 5
Autores: Sussarellu, Rossana; Lebreton, Morgane; Rouxel, Julien; Akcha, Farida; Riviere, Guillaume.
Copper contamination is widespread along coastal areas and exerts adverse effects on marine organisms such as mollusks. In the Pacific oyster, copper induces severe developmental abnormalities during early life stages; however, the underlying molecular mechanisms are largely unknown. This study aims to better understand whether the embryotoxic effects of copper in Crassostrea gigas could be mediated by alterations in gene expression, and the putative role of DNA methylation, which is known to contribute to gene regulation in early embryo development. For that purpose, oyster embryos were exposed to 4 nominal copper concentrations (0.1, 1, 10 and 20 μg L−1 Cu2+) during early development assays. Embryotoxicity was monitored through the oyster embryo-larval...
Tipo: Text
Palavras-chave: Oyster; Embryotoxicity; Copper; Gene expression; DNA methylation.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00417/52856/53756.pdf

Monoclonal antibodies against Bonamia ostreae (Protozoa: Ascetospera), an intrahaemocytic parasite of flat oyster Ostrea edulis (Mollusca : Bivlavia)
Provedor de dados: 5
Autores: Rogier, Hervé; Hervio, Dominique; Boulo, Viviane; Clavies, Christine; Hervaud, Eliane; Bachere, Evelyne; Mialhe, Eric; Grizel, Henri; Pau, Bernard; Paolucci, Francis.
The protozoan Bonamia ostreae (Ascetospora), a paasite of the flat oyster Ostrea edulis, was purified by differential and isopycnic centrifugations. Mice of the strain Balb/c were immunized with purified parasites and hybridomas were prepared by fusion of immunized mouse splenocytes with the mouse myeloma cell line P3-X63-Ag8-653. From the fusion, 12 clones were isolated and saved. The resulting antibodies were characterized with a solid phase radioimmunoassay (RIA). Antibodies from 7 clones reacted only with B. ostreae and not with normal host tissue. Although some of the antibiodies identified. One of these antibodies (20B2-1B12) has an apparent association constant of ca 3 X 10(8) M-1 and bound to a number of different sites on the parasite. These...
Tipo: Text
Palavras-chave: Monoclonal antibodies; Oyster; Ostrea edulis; Bonamia ostreae.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/publication-2756.pdf

Les risques conchylicoles en Baie de Quiberon. Deuxième partie : le risque de prédation sur l’huître creuse Crassostrea gigas. Rapport final du projet Risco 2010-2013
Provedor de dados: 5
Autores: Mazurie, Joseph; Stanisiere, Jean-yves; Bouget, Jean-francois; Langlade, Aime; Leclerc, Emilie; Quinsat, Kevin; Herve, Gilles; Augustin, Jean-marie; Ehrhold, Axel; Sinquin, Jean-marc; Meidi-deviarni, Ika; Goubert, Evelyne; Cochet, Helene; Dreano, Alain.
This study (“Risco”), implicating both industry, socio-economic experts and biologists, was funded by the Regional Council of Brittany, for 3 years (2010-2012), to investigate about the causes of oysters (Crassostrea gigas) mortalities in the bay of Quiberon (South Brittany, France). The protocol including both a sonar and video visualization of the bottom, and a monthly survey of 15 experimental oyster structures, allowed to assess the risk due to predation. A clear spatial distribution of the predatory effect was evidenced, with starfish (Asterias rubens and Marthasterias glacialis) predominating in the North-East sector, and boring snails (Ocenebra erinacea and Pterophora inornata) in the South-Center area.. The main mortalities from these predators...
Tipo: Text
Palavras-chave: Baie de Quiberon; Huître; Crassostrea gigas; Risque; Mortalité; Prédation; Étoiles de mer; Bigorneaux perceurs; Risco; Bay of Quiberon; Oyster; Crassostrea gigas; Risk; Mortality; Predation; Starfish; Oyster drills; Risco.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00180/29130/27534.pdf

Suivi de la reproduction de l'huître creuse Crassostrea gigas et de la moule Mytilus edulis dans le bassin de Marennes-Oléron. Bilan de trois années d'observation de 1997 à 2000. Rappels sur la reproduction de C. gigas et la technique de pêche de larves
Provedor de dados: 5
Autores: Arnaud, Christophe; Faury, Nicole; Bouquet, Jean-paul; Guesdon, Stephane.
Monitoring of reproduction in the oyster Crassostrea gigas, and more particularly in the mussel Mytilis edulis were conducted, in the Marennes-Oléron Bay each year, from June to September. This report gives the main results obtained in 1997, 1998, 1999,2000 and compares the results between years. It also summarises the fishing techniques used and gives information on larval development in the annexes. NOT CONTROLLED OCR
Tipo: Text
Palavras-chave: Marennes Oléron; Larvae; Reproduction; Mussel; Oyster; Marennes Oléron; Larves; Reproduction; Moule; Huître.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/rapport-3883.pdf

Seston dynamics and bivalve feeding in the Bay of Marennes-Oléron (France)
Provedor de dados: 5
Autores: Zurburg, Wouter; Smaal, Aad; Heral, Maurice; Dankers, Norbert.
Within the framework of an investigation into the carrying capacity of the Bay of Marennes-Oléron (France) for bivalve culture, the in situ uptake of suspended particulate material by oysters (Crassostrea gigas) and mussels (Mytilus edulis) was determined in experiments with benthic ecosystem tunnels. Very high fluctuations in seston quantity and quality were observed within and between tidal cycles. The percentage of organic carbon was inversely related to seston quantity at low concentrations. Organic carbon was diluted by resuspension of material rich in inorganic matter. At high seston concentrations a constant level of about 2% organic carbon was found. The CIN ratio was relatively constant throughout the seasons and fairly low (6.5 to 8.4). Owing to...
Tipo: Text
Palavras-chave: Microphytobenthos; Chlorophyll; Feeding; Mussel; Oyster; Seston quality; Seston load.
Ano: 1994
URL: http://archimer.ifremer.fr/doc/1994/publication-6843.PDF

Flat oyster follows the apoptosis pathway to defend against the protozoan parasite Bonamia ostreae
Provedor de dados: 5
Autores: Gervais, Ophelie; Chollet, Bruno; Renault, Tristan; Arzul, Isabelle.
The in vitro model Ostrea edulis hemocyte - Bonamia ostreae is interesting to investigate host-parasite interactions at the cellular level. Indeed, this unicellular parasite infects the flat oyster Ostrea edulis and multiplies within hemocytes, the central effectors of oyster defenses. Apoptosis is a mechanism used by many organisms to eliminate infected cells. In order to study the potential involvement of this mechanism in the oyster response to B. ostreae, in vitro experiments were carried out by exposing hemocytes from the naturally susceptible oyster O. edulis and a resistant oyster species Crassostrea gigas to live and heat-inactivated parasites. Hemocyte apoptotic response was measured using a combination of flow cytometry and microscopy analyses....
Tipo: Text
Palavras-chave: Apoptosis; Host-parasite interactions; Parasite; Oyster; Bonamia ostreae; Ostrea edulis.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00346/45692/45312.pdf

Impact du sédiment sur les mortalités estivales de naissain d'huîtres creuses Crassostrea gigas en baie de Quiberon
Provedor de dados: 5
Autores: Bedier, Edouard; Knoery, Joel Radford; Fleury, Pierre-gildas; Quiniou, Francoise; Langlade, Aime; Cozic, Amandine; Delesmont, Edith; Delesmont, Régis; Caisey, Xavier; Lecureuil, Laetitia.
The phenomenon of summer mortalities of the Pacific cupped oyster Crassostrea gigas is observed in France since the beginning of the 90's. These mortalities are classically associated to younger stages and summer temperatures and occur during the reproduction period of the animal. The studies undertaken during the project Morest (2001-2005), showed that a number of biological and environmental risks, the interaction of them induces lethal stresses for animals in physiological weakness, exists in summer. Among these risks, that which is withstood by the oysters bred close to the sediment proved to be significant in intertidal areas. In Quiberon bay (southern Brittany, France), the breeding practices of sowing oysters in deep water is thus likely to expose...
Tipo: Text
Palavras-chave: Huître; Crassostrea gigas; Mortalité; Sédiment; Composé réduit; Flux; Sulfure; Ammonium; Oyster; Crassostrea gigas; Mortality; Sediment; Reduced compound; Flux; Sulphide; Ammonia.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/00108/21956/19550.pdf

Economic Analysis of Using Soybean Meal as a Mushroom Growing Substrate
Provedor de dados: 31
Autores: Fewell,   Jason E.; Gustafson,   Cole R.
Mushrooms have been grown commercially on many different substrates for years, usually agricultural by-products such as straw or stover.  Increased popularity for specialty mushrooms with consumers has led to increased production and great demand for economic substrates.  Oyster mushrooms are easier to grow relative to other types of mushrooms and their production has increased dramatically in recent years.  This study examines the economic feasibility of using soybean hulls as a primary substrate for oyster mushrooms, replacing traditional wheat straw.  The study uses a cost-benefit analysis to determine an optimal substrate based on yield and the number of crops harvested per year.   The study shows that soybean hulls, combined with corn gluten or...
Tipo: Report
Palavras-chave: Oyster; Mushrooms; Substrate; Soybean; Hulls; Meal; Economic; Feasibility; Crop Production/Industries.
Ano: 2007
URL: http://purl.umn.edu/7634

Growth and antioxidant response of juvenile oysters Crassostrea sikamea and Crassostrea corteziensis treated with Streptomyces strains
Provedor de dados: 45
Autores: García-Bernal,M.; Medina-Marrero,R.; Campa-Córdova,Á.I.; Mazón-Suástegui,J.M.
ABSTRACT The effect of three Streptomyces strains (N7, RL8 and V4) and a mixture of Bacillus (BMix) on the growth (Weight, Size) and superoxide dismutase activity (SOD) in hatchery-reared juvenile oysters Crassostrea corteziensis and Crassostrea sikamea was investigated to determine their probiotic potential. Microorganisms were added to culture water at 1×106 CFU/ml once a day during 30 days and all oysters fed daily a microalgae mix. Juveniles of C. sikamea treated with strains N7, RL8 and V4 had a significant weight gain compared to the control group. C. corteziensis juveniles treated with strains RL8 and BMix showed a significantly higher weight gain than the control group. No significant size increase was observed in any treated group for both oyster...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Actinomycetes; Oyster; Growth; Probiotic effect; SOD activity.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352019000601993

Relationship between environmental variables and growth of Pteria colymbus (Mollusca Bivalvia: Pteriidae), at three cultivation depths
Provedor de dados: 50
Autores: Freites,Luis Felipe; Guevara,Miguel; Márquez,Adrián; Revilla,Jormil; Narváez,Mariela; Lodeiros,César.
ABSTRACT We studied the influence of environmental variables associated with three water depths (2, 6 and 10 m) on shell growth, soft tissues dry mass (STDM) and survival of the Caribbean winged oyster Pteria colymbus (Roding, 1798). chlorophyll-a (Chl-a), dissolved oxygen, particulate organic matter (POM) and temperature were studied at each depth. Oysters were placed in 135 plastic baskets with five individuals in each basket. Three baskets at each depth were chosen at monthly intervals for measurements of biometric parameters, biofouling, and survival. At the end of the study, dry mass of the individuals grown at 10 m was significantly lower (Kruskal-Wallis non-parametric test KW, P &lt; 0.05) with the highest values of STDM corresponding to oysters...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biofouling; Environment; Depth; Oyster; Survival.
Ano: 2020
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-97612020000100009

Raw oysters can be a risk for infections
Provedor de dados: 55
Autores: Vieira,Regine Helena Silva dos Fernandes; Sousa,Oscarina Viana de; Costa,Renata Albuquerque; Theophilo,Grace Nazareth Diogo; Macrae,Andrew; Fonteles Filho,Antonio Adauto; Rodrigues,Dália dos Prazeres.
The aims of this study were to count and identify sucrose positive and negative vibrios isolated from cultivated Crassostrea rhizophorae oysters during their growing cycle. Every month for 12 months, 10 to 18 oysters were collected for study. Collections occurred at the Center for Studies of Coastal Aquaculture (CSCA), which is associated with the Institute of Marine Science, Labomar, located in Euzebio, Ceará, Brazil. Approximately 150 oysters and their intervalvular liquor were studied. Vibrio Standard Plates Counts (SPC) from oyster meat and their intervalvular liquor varied from 25 to 59,000,000 CFU/g. For most of the 12 months of the oysters' life, it was possible to identify Vibrio parahaemolyticus. Vibrio carchariae was identified in four...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Vibrio spp; Oyster; Public health; Vibrio parahaemolyticus; Vibrio carchariae.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702010000100013

Bacteria of fecal origin in mangrove oysters (Crassostrea rhizophorae) in the Cocó River estuary, Ceará State, Brazil
Provedor de dados: 58
Autores: Silva,Ana I.M.; Vieira,Regine H.S.F.; Menezes,Francisca G.R.; Fonteles-Filho,Antonio A.; Torres,Regina C.O.; Sant'Anna,Ernani S.
This study was aimed at evaluating the microbiological quality of mangrove oysters (Crassostrea rhizophorae), collected at a natural oyster bed in the estuary of Cocó river (Fortaleza, Ceará, Brazil). MPN values were used for estimating the total (TC) and fecal (FC) coliforms and Enterococcus spp. TC and FC MPN values in the whole muscle and intervalve liquid ranged from &lt;1.8 to &gt;1,600/g and from &lt;1.8 to 920/g, respectively. The MPN estimates for Enterococcus spp. were between &lt;3.0 and &gt;1,100/g. No correlation was found between the physico-chemical parameters (temperature, salinity and pH) of the surrounding water and the bacteriological contamination levels found in the tested oysters. The only correlation found was between TC and FC...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Oyster; Total and fecal coliforms; Enterococci; Bacteriocins.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822004000100021