Genetic analysis of temporal and spatial disjunction in populations of yellowfin goby, Acanthogobius flavimanus

Yellowfin goby, Acanthogobius flavimanus, is a demersal, estuarine fish native to eastern Asia that has extended its distribution to estuaries of the eastern Pacific Ocean. This provides an opportunity to study the effects of founder events that result in spatial disjunction. The goal of this thesis is to determine the extent to which exogenous reinforcement, or self-recruitment, contributes to the maintenance of four populations of yellowfin goby in estuaries using data from microsatellite loci. Using MIGRATE, effective population sizes were estimated for Upper Newport Bay (168), Bolsa Chica (100), San Francisco Bay (171) and Tokyo Bay (199). Estimates of variance effective size for Newport Bay (7), Bolsa Chica (38) and San Francisco Bay (86) were also made. Using Arlequin, non-significant pairwise RST comparisons were observed for Bolsa Chica-Tokyo Bay and San Francisco-Tokyo Bay. Based on migration rates and allelic diversity, Tokyo Bay is the evident source for all invasive populations in California. Based on RST comparisons, populations in San Francisco Bay and Bolsa Chica were directly established from Tokyo Bay, while the Upper Newport Bay population is probably the result of emigration from Bolsa Chica.