Hydrodynamic Facilitation of Gregarious Settlement of a Reef-Building Tube Worm

摘要

Habitat selection occurs for many benthic marine invertebrates when theirplanktonic larvae settle and metamorphose into benthic adults. Initiation of settlement presumably is a response to chemical cues associated with preferred adult habitats. An understanding of the interaction between the relevant chemical and physical processes has been impeded, however, because the naturally occurring compounds that induce larval settlement have eluded isolation and identification and because experimental assessments of larval substrate selection have been conducted in still water rather than under realistic flow conditions. Active selection of substrates at the time of settlement has only recently been shown to occur under realistic flow conditions. Gregarious settlement is common among marine invertebrates, including barnacles, mussels, and oysters, and is thought to be mediated by chemical signals originating from conspecific adults. The larvae of some sabellariid polychaetes settle preferentially upon contact with the cemented sand tubes of adult conspecifics to form large aggregations.