Meeting Abstract

P2.102  Monday, Jan. 5  Host-specific morphological plasticity obscures species boundaries in a commensal barnacle LAKE, D.T.**; FRICK, M.G.; RAWSON, P.D.; ZARDUS, J.D.; The Citadel, Charleston, SC; Caretta Research Project, Savannah, GA; University of Maine, Orono; The Citadel, Charleston, SC laked1@citadel.edu

Barnacles are familiar shoreline animals; however, less well known are the many species that live attached to other animals as obligate commensals. The four recent species of barnacles in the genus Chelonibia as adults are only found attached to marine vertebrates, crustaceans and molluscs: C. testudinaria and C. caretta attaching to sea turtles, C. manati to manatees, and C. patula to crabs and snails. Sharing similarities in form but varying in size and growth habits, these taxa have been deemed separate species at least since Darwins 1854 monograph on the Cirripedia. However, despite morphological differences these barnacles may in fact constitute a single species that exhibits different forms depending on host affiliation. To test this hypothesis, we compared genetic variation between specimens of Chelonibia collected from sea turtles, crabs, and manatees. DNA was extracted using commercially available kits and a portion of the mitochondrial gene cytochrome oxidase I (COI) was amplified through the Polymerase Chain Reaction (PCR). Resulting sequences were compared and analyzed phylogenetically. The results support our hypothesis in part, showing low or no genetic variation among C. testudinaria, C. manati, and C. patula but significant species-level divergence with C. caretta.