Developmental Symbiosis: A Sponge Larva Needs Symbiotic Bacteria to Succeed on the Benthos.

Settlement and metamorphosis of marine invertebrate larvae are processes of profound developmental, morphological, physiological and ecological change. That these processes in larvae of a marine sponge critically rely on products supplied by endosymbiotic bacteria signals the importance of developmental symbiosis among the most basal metazoans.