Diversité génétique et dynamique du recrutement chez l'huître plate Ostrea edulis L.

In order to understand better some fundamental aspects of the bivalve biology, one has to pay attention to the variance of their breeding success, the time structure of the populations and their effective size. An abundant literature shows the existence of a heterozygote deficit as well as positive relationships between heterozygoty and fitness components. This last point is the subject of explanatory hypotheses which have never been clearly decided between until now. One of these hypotheses is the possible existence of a certain degree of inbreeding among those populations. This is only possible in the case of separated colonies coming from a small amount of spawners, thus creating blood relations between individuals recruited from the same area, and consequently a restricted local effective stock and the inbreeding of their offspring. In order to go deeper into this hypothesis, the interactions between genetics and demography at a population level have been studied on flat oyster larvae, spats and adults, through the analysis of five microsatellite markers. ...