Phylogeography of the endemic goby, Rhinogobius maculafasciatus (Pisces: Gobiidae), in Taiwan

Genetic diversity within and among populations of the spot-banded goby, Rhinogobius maculafasciatus, in Taiwan was studied by analyzing mitochondrial DNA sequences. The sequence length varied from 2124 to 2126 bp and included the complete cytochrome b gene, 2 tRNA genes, and the control region of mitochondrial DNA (mtDNA). Forty-one haplotypes were identified from 60 specimens. Sequence analysis indicated that 2 distinct clades exist in R. maculafasciatus, and that each clade is divided into 2 subgroups. The 3 populations of the Kaoping River were not included in the same clade. The population sampled from the Lanyang River in northeastern Taiwan probably originated from the eastern coast of China and is connected with populations in southwestern Taiwan by the Coastal Current which flows along the western coast of Taiwan. A hierarchical examination of 6 populations in 3 drainage basins using analysis of molecular variance indicated high genetic differentiation (68.37%) among populations within basins. The results support the hypothesis that the current genetic structure was strongly affected by changes in drainage patterns due to geomorphological processes that occurred in the recent past when the main island of Taiwan formed and separated from the Asian continent 0.55 My before the present.