Morphological and behavioural traits of a feral strain of the common carp Cyprinus carpio from Lake Biwa in Japan were compared with those of two domesticated strains reared in Japan (one commercial strain and one ornamental koi). To compare genetically inherited traits, all fish were reared from eggs under similar environmental conditions. Using these fish, the following five traits were compared among the three strains: body...

Wild common carp ( Cyprinus carpio ) are probably suffering from biological invasions of conspecific domesticated strains. However, such invasions may be largely camouflaged by morphological similarities between introduced and native strains. We conducted a large survey of mitochondrial DNA sequences (complete D‐loop region) from 11 localities in Japan. From a total of 166 individuals, 28 haplotypes were determined to fit into...

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...