Behavioural adaptations and diet specificity of sacoglossan opisthobranchs

摘要

Sacoglossan opisthobranchs are suctorial feeders and the majority of species feed on the cytoplasm of siphonalean green algae. All shelled sacoglossans feed on the morphologically variable, but anatomically strictly monosiphonaceous algal genusCaulerpa. Thus stenophagy is plesiomorphic within the group. After losing the shell, an adaptive radiation of diets has taken place. Most shellless species are stenophagous, but some, in particular species with temperatt distributions, are relatively euryphagous.