Optimisation d'une méthode standardisée de choc thermique sur des juvéniles de Crassostrea gigas : application à des populations d'ecloseries
Mortality among juvenile Crassostrea gigas has been occuring during the summer months since 1995 and is now considered to be a real problem for French oyster culture. The aim of this study was to standardise the stress that could be applied to Crassostrea gigas spat. In initial experiments in 1998,...
| Main Authors: | , , , , , |
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| Format: | Report |
| Language: | French |
| Published: |
1999
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| Subjects: | |
| Online Access: | https://archimer.ifremer.fr/doc/00080/19095/16690.pdf https://archimer.ifremer.fr/doc/00080/19095/ |
| Summary: | Mortality among juvenile Crassostrea gigas has been occuring during the summer months since 1995 and is now considered to be a real problem for French oyster culture. The aim of this study was to standardise the stress that could be applied to Crassostrea gigas spat. In initial experiments in 1998, the weight of individual spat and the duration of a heat shock at 50°C in freshwater, adapted for oysters of between 500 and 2000 mg, were built into a model to obtain 50% mortality. However, the precision was low (50%) and will need to be improved in the future. Following this, hatchery-produced juveniles weighing 10 to 500 mg were subjected to heat shock at 45°C in heshwater the duration of the shock was calculated based on a model built in 1997. The results showed a high intra and inter-population variability in mortality. This variability seemed to be related to the genetic characteristics of each population and to the growth rate. However, the results of a study of growth where the nutritional conditions were different showed that this test is probably an estimate of a limited oyster fragility and is not predictive of other kinds of mortality. However, this process could be used by breeders to estimate the sensitivity of different spat populations to heat shock before rearing, and in applied scientific research as a standard stress procedure in genetics, physiology and pathology.https://w3.ifremer.fr/archimer-admin/abstract.jsp# L'apparition et la répétition depuis 1995, d'importantes mortalités estivales chez les juvéniles d'huître creuse Crassostrea gigas en élevage représente un réel problème pour l'ostréiculture en France. Cette étude s'inscrit donc dans l'esprit des travaux antérieurs visant à standardiser un stress applicable au naissain d'huître creuse. Un modèle utilisable pour le naissain de captage naturel et prenant en compte le poids moyen, vis à vis du temps d'application d'un choc thermique à 50°C appliqué à des juvéniles de 500 à 2000 mg, a été établi en 1998 pour provoquer 50% de mortalité. ... |
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