The masu, or cherry salmon (Oncorhynchus masou) is found in northwestern Pacific waters and apparently as landlocked populations in a few Korean mountain streams . I recently heard that they are occasionally caught in Alaskan waters. Unlike most of the other members of the genus Oncorhynchus, a few cherry salmon are able to survive to spawn a second time. The only other members of the genus able to do this are, of course, the rainbow/steelhead (O. mykiss) and the cutthroat (O. clarki).

Most of the species within the genus Oncorhynchus are sufficiently close genetically to breed together (cutthroat and rainbow for example) but in most cases run timing and differing preferences in spawning habitat (gravel size, current velocity, etc.) work to maintain isolation between the species; at least under natural conditions.