Oncorhynchus Masou - Life Cycle

Life Cycle

Like other Pacific salmon, its life cycle is subdivided into marine and freshwater periods; in rivers, this species lives from 1 to 3 years and can form living fresh-water forms. The sea life cycle, depending on the age of the young, continues for 2 to 3.5 years. In the sea, the masu salmon feed 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 next year, too. Emerging from the nest, the young do not roll into the sea 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 chironomid, stone fly and may fly larvae, and on air insects. The masu salmon rolls into the sea in its second, occasionally even third year of life.