WILSON, M. M.*; TURNER, R. L.: Mode of Reproduction and Genetic Structure of the Brooding Hermaphroditic Sea Cucumber Synaptula hydriformis Using Randomly Amplified Polymorphic DNA

The viviparous sea cucumber Synaptula hydriformis is a simultaneous hermaphrodite that maintains multiple broods within the perivisceral coelom. It is an epiphytic species that clings to drift macroalgae, fleshy and calcareous attached algae, blades of seagrass, and the submerged roots of mangrove trees. Over the last century, there has been much disagreement over the method of fertilization. Authors of recent studies suggest that this species is a facultative, if not obligate, self-fertilizer. Synaptula hydriformis presents an intriguing case study for genetic diversity because its life history could involve relatively little gene flow among geographically isolated populations even with complete out-crossing. Randomly amplified polymorphic DNA (RAPD) analysis is being used to assess rates of self-fertilization and cross-fertilization in S. hydriformis collected in central and southern Florida. RAPD banding patterns of the brooded young will be compared with those of the maternal adult. RAPD analysis will also be used to examine the genetic diversity at several geographic scales: brood, algal clump, collection site, and within the Western Atlantic. This research is funded in part by the PADI Foundation.