ABSTRACT
Abstract The feeding interactions between sacoglossan (= ascoglossan) sea slugs and their algal prey are discussed. Many of these gastropod molluscs are capable of kleptoplasty-a process whereby the slugs photosynthesize using chloroplasts ingested from their algal diet. Despite extensive study, the importance of kleptoplasty in sacoglossan (slug) feeding ecology remains poorly defined. The effects of slug grazing on marine algae, particularly in tropicalsubtropical regions are also unclear. We extend the scope of previous reviews and synthesize the disparate areas of sacoglossan feeding ecology. The review is in three parts: first, the diet of sacoglossans is discussed; secondly, the role of kleptoplasty in slug feeding ecology is examined and thirdly, the effects of grazing by the slugs on their food algae are considered. Further research is required to clarify sacoglossan feeding ecology, in particular slug food choice in the field, the importance of kleptoplasty to the range of slug diets and the effects of slug grazing on tropical marine algae.
