FAUCCI, A.; HADFIELD, M.G.; Univ. of Hawaii, Honolulu: Marine dispersal patterns in Hawaii: a casestudy of tubesnails with differing developmental modes

Population genetic data can be used as an indirect measure of dispersal, because the variation in the distance that larvae are transported, and subsequently gene flow, result in characteristic genetic patterns. Vermetids or tubesnails are sessile gastropods abundant in shallow marine waters, which show a range of developmental patterns from obligate, pelagic planktotrophic larvae, which reside in the plankton for several weeks, to species with directly developing benthic juveniles, which lack a planktonic phase. The mitochondrial protein-coding gene cytochrome oxidase I was sequenced for five species from the Hawaiian Islands. Neighbor-joining, maximum-likelihood, and maximum-parsimony trees were produced. Species with direct development show highly structured populations throughout the Hawaiian Archipelago, suggesting very limited to no dispersal among islands. Species with planktotrophic larvae show no structure throughout the main Hawaiian Islands and only some structure throughout the Northwestern Hawaiian Islands. Furthermore, historical hypotheses regarding the biogeography of the Hawaiian Archipelago have been tested using a phylogenetic approach and questions regarding the colonization of the Hawaiian Island are being discussed.