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

Juveniles of four species of shallow water ophiuroids were captured in a pl ankton net tethered on the reef flat at Carrie Bow Gay, Belize: Ophiothrix orstedii, Ophiothrix angulata, Ophiocoma wendtii, and Ophiactis savignyi. T hese water-borne animals were similar in size to the smallest benthic consp ecifics found on the reef, but considerably larger than newly metamorphosed postlarvae. Thus, this first report of planktonic dispersal by juvenile co ral reef ophiuroids suggests that they reenter the plankton and drift, or p erhaps raft on algal fragments, after first having recruited to the benthos . The occurrence of water-borne juveniles in species with planktotrophic an d abbreviated larval development, and with clonal, asexual reproduction sug gests that postlarval drifting may augment larval dispersal in some ophiuro id species and substitute for it in others.