Observations on the wentletrap Epitonium clathratulum (Kanmacher, 1797) (Prosobranchia, Epitoniidae) and the sea anemone Bunodosoma biscayensis (Fischer, 1874) (Actiniaria, Actiniidae)

A review is given of the most important literature on parasite/host (or predator/prey) relations of Epitoniidae and Anthozoa, and various modes of feeding are mentioned. An as yet unreported association of the wentletrap Epitonium clathratulum and the sea anemone Bunodosoma biscayensis is described. Both species were collected at Plage d’Ilbarritz, Côte Basque, SW. France. Field and aquarium observations suggest that E. clathratulum feeds on partly digested food in the gastric cavity of its host-anemone. This is achieved in a way as yet unprecedented: the wentletrap climbs the oral disc of its host and introduces its proboscis through the mouth slit into the gastric cavity to feed. The sequence of climbing the host and feeding is described and depicted.