Population Genetic Structure of the Temperate Scleractinian Coral, Oculina Arbuscula, in Coastal Georgia

Dispersal of marine organisms has generally been assumed to be demographically open with planktonic larvae exploiting ocean currents to travel long distances. However, recent studies report evidence of local larval recruitment. In this study, I hypothesized that populations of the temperate coral, Oculina arbuscula, are maintained primarily by local recruitment off the Georgia coast because: 1) suitable substrate for settlement is patchy and 2) O. arbuscula\u27s branching morphology is conducive to asexual reproduction by fragmentation. To address this hypothesis, I combined data from allozyme electrophoresis, histocompatibility assays, and despersion of established colonies. Results indicated substantial local recruitment maintained primarily by sexual reproduction rather than asexual fragmentation. Sexually produced planulae are not only philopatric, but also show evidence of some migration among populations. In this temperate species, local recruitment primarily maintains aggregated populations of O. arbuscula