EPIBIONTS OF HAWKSBILL SEA TURTLES IN SOUTHEAST FLORIDA

Sea turtles, like all marine vertebrates, can host considerable populations of epibionts, i.e., externally-attached symbiotic organisms on the skin and shell. These organisms can form facultative, obligate, and sometimes endemic commensal relationships with sea turtles, whose outer surface provides an insular, mobile substrate for their colonization and dispersal. Juvenile hawksbill turtles, Eretmochelys imbricata, living off Florida’s east coast can develop considerable epibiotic growth. I analyzed 236 photographs of 213 hawksbill turtles from SE Florida to document colonization patterns, relative abundance, and ecology of macroscopic commensals, including sea turtle barnacles (Chelonibia spp.), fire coral (Millepora spp.), and sponges (Porifera). I found that the epibionts increased significantly in overall abundance with turtle size. Hawksbill epibionts may reflect turtle movement and dispersal and can serve as a model for studying successional processes of epibiotic colonization.