Mitochondrial DNA Haplotypes of Killer Whales around Hokkaido, Japan

Abstract. In this study, we examined a genetic variation of killer whales, Orcinus orca, from off the coast of Hokkaido, Japan, by sequencing the D-loop and cytochrome b (Cyt-b) regions of the mitochondrial genome. Three D-loop and two Cyt-b haplotypes were identified from eight skin biopsies. These five haplotypes had been previously deposited at GenBank and the International Nucleotide Sequence Database Collaboration (INSDC). Two D-loop and one Cyt-b haplotypes were consistent with the marine mammal-eating “Transient” ecotype previously reported in Japanese waters. One D-loop and one Cyt-b haplotypes were identified as the fish-eating “Resident” or “Offshore” ecotype that is the first record of this ecotype in Japanese waters. Our study showed that different ecotypes exist in Japanese waters, contributing to the conservation and management of killer whales.