REPRODUCTION IN CREPIDULA-PHILIPPIANA (GASTROPODA, CALYPTRAEIDAE) FROM SOUTHERN CHILE

Crepidula philippiana differs from most congeneric species in having o nly one embryo per capsule which attains a great hatching size, a feat ure shared only with C. monoxyla from New Zealand. In C. philippiana, this single embryo results from the ingestion of numerous nurse eggs. The clutch size (fecundity per spawn) is accordingly reduced. A signif icantly smaller but more uniform hatching size is observed among the r emaining species of Crepidula, and clutch size is greater. Why do Crep idula species adopt different embryo nourishing mechanisms to attain d irect development? Hypotheses considering ecological aspects and repro ductive strategies are discussed.