Protandric Hermaphroditism in Prosobranch Gastropods

Very few investigations have been carried out about factors responsible for sex differentiation in protandric hermaphrodite molluscs. In Cvepidula plana, Gould (1947) showed the occurrence of a feminizing influence when individuals are isolated and a masculinizing effect of the female at the bottom of the chain on upper individuals of the association. However, experiments of Coe (1942) on Crepidula onyx and Wilczynsky (1958) on Crepidula fornicata, partly disprove Gould’s work.