Delphinus orca Linnaeus, 1758 p.77; Type locality- eastern North Atlantic (European Seas).
Orca ater Cope, 1869 p.22; Type locality- North Pacific (Oregon to Aleutian Islands).
Orca pacifica Gray, 1870 p.76; Type locality- North Pacific.
Orcinus orca: Kuroda, 1938 p.18; Won, 1958 p.435; Won, 1967 p.85; Won, 1968 p.227; Kim et al., 2000 p.84; Kim, 2004 p.237.
Range: Incidental catches of O. orca occurred in the East Sea and around Jeju Island (Cetacean Research Institute 2007; Fig. 93).
Remarks: The killer whale, an abundant, highly social species with reduced genetic variation, has no consistent geographical pattern of global diversity and no mtDNA variation within regional populations (Hoelzel et al. 2002). Because of range-wide low genetic diversity, the killer whale remains a monotypic species, even though two subspecies (resident killer whale and transient killer whale or Bigg’s killer whale) or three ecotypes have been proposed (Reeves & Read 2003; Morin et al. 2010). Compared to Antarctic and eastern North Pacific populations, which have three well-described ecotypes (Stevens et al. 1989; Pitman & Ensor 2003), populations of O. orca in the western North Pacific have been poorly studied. Both specialized piscivorous resident and mammal eating transient ecotypes inhabit the western North Pacific Ocean (Burdin et al. 2007; Pilot et al. 2010; Morin et al. 2010); the ecotype inhabiting seas around Korea remains uncertain.