Genetic variation in the Indian rice frog, Rana limnocharis (Amphibia: Anura), in Taiwan, as revealed by allozyme data

We conducted an electrophoretic survey of 12 Taiwanese populations of Rana limnocharis (nine from the main island and three from adjacent islets). Analysis using resultant data and previously published data for populations of continental China and the southern Ryukyus indicated the presence of substantial genetic differentiation between eastern (i.e., eastern main island and Lutao and Lanyu islands) and the remaining (i.e., northern, western, and southern main island and Penghu Island) populations within Taiwan, with the latter being more similar to continental Asian populations. The southern Ryukyu population, while being more similar to the eastern Taiwan populations, was the most divergent of all populations examined. The genetic differentiation between eastern and remaining Taiwanese populations is considered to reflect the primary interruption of gene flow between them by the central mountain range of the main island. However, the eastern Taiwan populations lack fixed or nearly fixed alleles unique to themselves, and they share most alleles with one or both of the remaining Taiwanese and southern Ryukyu populations. Genotype of the current eastern Taiwan populations may have been derived from an introgression between western Taiwan populations and former eastern Taiwan populations that were genetically closer to the southern Ryukyu populations.