Oysters have an alternative sexuality. They can be male or female during a season then change sex next year.
The meeting of ovules and sperm cells happens in the water at the mercy of the waves : it is the fecundation ...

During July, the oyster farmers place on appropriate grounds collectors (pickets in slate or plastic supports : " pléno ", small cups and tiles in Arcachon) which are supports for these small larvas. Once fixed, they change completely into " little oysters ", that is to say into " broods ".. 18 months later, the brood has got bigger on the collector, and it has to be " détroquée " (unsticked). It is what will be
sowed on the oyster-beds. These operations are realized on the collecting areas in Arcachon or in Charente. The brood is selected and bought between March and June, to be sowed in Brittany.