Genetic relationships of Japanese and Korean bagrid catfishes inferred from mitochondrial DNA analysis

Partial sequences of the cytochrome b gene (740 bp) and restriction fragmen t length polymorphisms in the mitochondrial DNA were used to examine inter- and intraspecific relationships among nine species of bagrid catfishes (fam ily Bagridae) in Japan and Korea. Several opinions have been expressed rega rding the kinship among Japanese and Korean bagrid catfishes, based on exte rnal morphological similarities. Almost all of them, however, were rejected by the current data sets. For instance, it has been considered that the Ko rean species, Pseudobagrus brevicorpus and P. fulvidraco, were closely-rela ted to P. ichikawai and P. nudiceps, respectively, found in Japan. Resultin g trees indicated that P. ichikawai branched off separately from all of the remaining Pseudobagrus species. Similarly, P. nudiceps and P. fulvidraco w ere represented by distantly separated branches. The intraspecific genetic divergence of bagrid catfishes was relatively smalt, even among geographica lly distant populations.