We take a very broad approach to studies of settlement and metamorphosis of marine invertebrate animals. Metamorphosis in larvae of many invertebrates depends on very specific external chemical signals. Our studies include investigation of the chemical nature of a small metabolite from prey coral that induces settlement and metamorphosis in the sea slug Phestilla sibogae and of a complex substance from bacterial films that induces metamorphosis in the small fouling worm Hydroides elegans. We have extensively investigated settlement-signal transduction mechanisms in these larvae, as well as the roles of de novo transcription events following induction. We are interested in the genetics of both bacteria and larval populations in determining settlement in larval H. elegans. The latter work has led us to a major interest on the composition of marine biofilms, and thus on the interactions between marine microorganisms and developing marine animals at the time of larval recruitment. Finally, together with a collaborator from the University of California, we are studying the responses of invertebrate larvae with living benthic communities, both coral reefs and biofouling communities.This effort includes extensive field studies, research in very large and very small flumes, and extensive micro-videography of larvae at the point of settlement.