Planktonic dispersal of juvenile brittle stars (Echinodermata: Ophiuroidea) on a Caribbean reef

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 dispersal 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 occurrence of water-borne juveniles in species with planktotrophic and abbreviated larval development, and with clonal, asexual reproduction suggests that postlarval drifting may augment larval dispersal in some ophiuroid species and substitute for it in others.