A NEW SPECIES OF CREPIDULA (MOLLUSCA, MESOGASTROPODA, CALYPTRAEIDAE) FROM CHILE - ADDITIONAL CHARACTERS FOR THE IDENTIFICATION OF EASTERN PACIFIC PLANAR CREPIDULA GROUP

A new species of Crepidula is described. It was collected together wit h Pagurus edwardsii Dana and Pagurus perlatus H. Milne Edwards, inhabi ting the inside of empty shells of Tegula euryomphala Jones and other gastropods. The shell is low convex-oval in juveniles, low convex-oblo ng in males and concave-oblong elongated in females. In the adult phas es the apex projects slightly al the posterior border. The sinusoidal septum is 'V' shaped at its centre, with a smooth sulcus in the left q uarter. The osphradium has 2-13 digitiform leaflets according to phase s of the life cycle. The characteristically thin, external-lateral tee th of the taenioglossate radula possess a row of denticles. In additio n, evidence is given that: (1) males have a lanceolate penis with a sp ermatic tube; (2) the intracapsular-embryonic development starting wit h many embryos, occurs with a decrease at the larvae-protoconch stage, each one with an adhered-vitelline mass, and culminates with a few pr ehatching juveniles of 1 mm size. In the expression of the consecutive -protandric hermaphroditic sexuality, the male phase is truly separate d from the female phase by a transition period at the population level . The shell and radular morphology, intracapsular development and ecol ogical antecedents allow the proposal of Crepidula coquimbensis as a n ew species, and suggest a future taxonomic revision of the group based , moreover, on osphradium structure and new characters of the reproduc tive system, such as penis morphology.