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Registros recuperados: 170 | |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 & 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 |
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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 |
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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 |
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Registros recuperados: 170 | |
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