Résumé
Crepidula convexa, a calyptreid gastropod with direct embryonic development, changes sex from male to female in the course of its lifetime (protandry). Under sex-allocation theory, male reproductive success should be independent from age and size (a proxy used for age). However, this may be counterbalanced by female cryptic choice or gregarious behaviour. Eleven polymorphic microsatellite loci were thus developed to examine paternity of embryos and larvae. This set of loci appears suitable to carry out paternity analyses due to the high exclusion probability of unrelated males given the maternal genotype.