Abstract
MtDNA sequence data ( c . 2100 bp of complete D‐loop + cytochrome b gene regions) showed a principal phylogenetic split within common carp Cyprinus carpio between the Lake Biwa wild form ( n = 3) and ‘Eurasian’ wild ( n = 18) and domesticated ( n = 35) forms. This supports the idea of the ancient origin of the Lake Biwa wild form, as well as the East Asian origin of wild common carp, previously proposed on the basis of fossil data. In addition, a possible multiple origin of koi carp was indicated by the polyphyletic distribution of five mtDNA haplotypes of koi carp within the ‘Eurasian’ clade.