Diet of Cypraea caputdraconis (Mollusca: Gastropoda) As It Relates to Food Availability in Easter Island

Abstract

Diet and food preferences of Easter Island's endemic cowrie, Cypraea caputdraconis (Melvill), are reported. Gut content analyses of specimens from different rocky intertidal localities around the island revealed that C. caputdraconis is primarily an herbivore. Algae composed > 90% of the cowrie's diet in all cases. Five algal genera, Cladophora, Sphacelaria, Ceramium, Galaxaura, and Pterocladia, were the most frequent and abundant items in the diet of C. caputdraconis. The feeding habits of C. caputdraconis are most similar to those of C. caputserpentis L. from Hawaii in that both have clearly herbivorous diets. Both species share the R-l type of taenioglossan radula, which also supports their close phylogenetic relationship. Indo-West Pacific populations of C. caputserpentis have been suggested as ancestral to C. caputdraconis from Easter Island.