On average, this salmon prefers a
temperate climate around the
latitude of 65–58°N, and in the sea, it prefers a depth of .
Life cycle Like other Pacific salmon, masu salmon's
biological life cycle is subdivided into freshwater and marine periods; in rivers, this species lives from 1 to 3 years and can form living freshwater forms. The sea lifecycle, depending on the age of the young, continues for 2.0 to 3.5 years. In the sea, the masu salmon feeds intensely on
crustaceans, less often on young fish. On attaining sexual maturity, in its third to seventh years of life, it enters rivers to spawn. Its spawning run starts earlier than that of other salmon species. After spawning, most passing fish die, and those that remain alive (preferentially dwarf males) participate in spawning the next year, too. Emerging from the nest, the young do not travel to the sea immediately, but remain in spawning areas, in the upper reaches of rivers, and on shallows with weak currents. The young move to pools and rolls of the river core to feed on chironomids, stone flies, and may fly larvae, and on airborne insects. The masu salmon travels to the ocean in its second, or occasionally even third year of life. ==Economic importance==