Genetic biogeography among insular populations of the amphidromous fish Plecoglossus altivelis assessed from mitochondrial DNA analysis

摘要: Ayu, Plecoglossus altivelis, is an amphidromous fish which isdistributed over the Japanese Archipelago including peripheralislands, some of harbor endangered populations. Weanalyzed nucleotide sequences mitochondrial DNA controlregion to clarify factors affecting genetic variabilityof mainland and insular As inferred from nucleotidediversity π, overall low variability in insularpopulations suggests their vulnerability extinction, althoughthere were still significant differences betweenpopulations. Patterns explained bygene flow with population as pairwisefixation index FST rate loss haplotypes assessedfrom haplotype diversity h, turn, these two arefunctions geographical distance andpopulation size, respectively. We conclude that geneticvariability observed on each island brought about by its owndynamic equilibrium maintained continuous immigration andlocal depending location theisland relative together size theisland. Conservation measures for populations arerecommended take this uniqueness into account.