PLANKTONIC DISPERSAL OF JUVENILE BRITTLE STARS (ECHINODERMATA: OPHIUROIDEA) ON A CARIBBEAN REEF

摘要

Juveniles of four species of shallow water ophiuroids were captured in a plankton net tethered on the reef flat at Carrie Bow Cay, Belize: Ophiothrix orstedii, Ophiothrix angulata, Ophiocoma wendtii, and Ophiactis savignyi. These water-borne animals were similar in size to the smallest benthic conspecifics found on the reef, but considerably larger than newly metamorphosed postlarvae. Thus, this first report of planktonic dis- persal by juvenile coral reef ophiuroids suggests that they reenter the plankton and drift, or perhaps raft on algal fragments, after first having recruited to the benthos. The occur- rence of water-borne juveniles in species with planktotrophic and abbreviated larval de- velopment, and with clonal, asexual reproduction suggests that postlarval drifting may augment larval dispersal in some ophiuroid species and substitute for it in others.