【Reading】しろざけ

【English Name】Chum Salmon

Shirozake (chum salmon) is a fish belonging to the genus Oncorhynchus of the family Salmonidae in the order Salmoniformes, with the scientific name Oncorhynchus keta. The standard Japanese name of this fish, widely beloved in Japan as "sake" or "shake," is formally shirozake.

Its main habitat is the North Pacific, and it is distributed over a wide range, including the Bering Sea, the Sea of Okhotsk, and the Sea of Japan. Within Japan, its upstream migration into the rivers of Hokkaido and the Tohoku region is famous; on the Pacific side, the southern limit is the Kuriyama River in Chiba Prefecture, and on the Sea of Japan side, a tributary of the Go River flowing through Shimane Prefecture is said to be the southern limit.

Although its flesh is reddish in color, biologically it is treated as a white-fleshed fish. That red color is due to astaxanthin (a carotenoid pigment) possessed by the crustaceans it eats as food, and is not the color of the muscle tissue itself.

As a sushi neta, farmed Atlantic salmon (commonly called "salmon") has become more widely established for raw consumption than shirozake itself. Wild shirozake carries the risk of parasites such as Anisakis, so when eaten raw, freezing treatment is a prerequisite. Salmon became widespread in Japanese sushi restaurants around 1990, and aggressive sales promotion from Norway is said to have been the turning point.

Mature fish that have reached the breeding season grow to roughly 70–80 cm in body length, and large individuals can comfortably exceed 90 cm. In autumn they ascend rivers to spawn, and most parent fish end their lives within a few days afterward. The timing of the upstream migration varies by region, and is mainly seen from October to December.