Reproduction et recrutement de la coque Cerastoderma edule L. a Saint-Pol-de-Leon (Bretagne Nord)

Investigation on the recruitment of Cerastoderma edule was carried out at St-Pol-de-Leon over three years. This approach is intended to disclose in the fluctuations of recruitment the part of variability linked with reproduction and spawning. Stages of sexual maturity are used together with a condition index. The reproductive activity spread out over the most part of the year, ripe individuals being observed even in winter. Main spawning took place in summer and autumn. Seasonal and interannual fluctuations of recruitment are associated with the variations of the condition index. An increase of the reproductive activity could be observed between 1987 and 1989 related with temperature. It is shown that this factor is the main responsible of the variations of recruitment.