Mitochondrial DNA phylogeography ofGlyptothorax fokiensisandGlyptothorax hainanensisin Asia

Whole mitochondrial DNA cytochromebsequences in 62 fish from 13 locations in Southeast China identified two major clades corresponding to two allopatric taxa,Glyptothorax fokiensis fokiensisandGlyptothorax fokiensis hainanensis. Reciprocal monophyly and a molecular clock separation between these two taxa of 2·3 million years indicate these taxa should be elevated to species. Mismatch distributions and Fu’sFSstatistic suggest that bothG. fokiensisandG. hainanensishave experienced recent population expansions. Analysis of molecular variance indicates that most of the genetic variation resides among populations within both species, withΦST= 0·645 forG. fokiensisand 0·801 forG. hainanensis, suggesting restricted gene flow among populations. Significant correlations between the geographic and the genetic distances provide support for the importance of geographic isolations between populations. Nested clade analysis also confirms low levels of genetic exchanges between the two major groups and between populations within each group. The phylogeographical pattern among populations ofGlyptothoraxin East Asia can be attributed to historical fragmentations, demographic expansions and occasional long‐distance dispersals stimulated by tectonic activity and Ice Age climate changes.