【Reading】しらうお

【English Name】Shirauo (Japanese Icefish)

Shirauo (Japanese icefish), written with the characters 白魚 or 鮊, is a small fish about 8 cm long belonging to the family Salangidae in the order Osmeriformes. It lives in brackish waters throughout East Asia, and while alive its semi-transparent body allows the spine and internal organs to be seen through it. A distinctive feature is that its body color turns milky white when it dies. The whole body has a wedge-like outline with a sharply pointed tip, and it has a small adipose fin behind the dorsal fin.

It is often confused with shirouo (family Gobiidae, order Perciformes), which is similar in appearance and ecology, but taxonomically it belongs to a completely different lineage. It is a relative of ayu (sweetfish) and wakasagi (Japanese smelt), and the two can be distinguished by the presence or absence of an adipose fin.

It is distributed throughout Japan from Hokkaido to southern Kyushu, with Hokkaido, Aomori, Akita, Ibaraki, and Shimane being representative production areas. Catches tend to be larger in eastern Japan, where adults that have migrated to brackish waters during the spring spawning season are caught with four-armed scoop nets and gill nets. It has long been loved as a flavor that heralds spring.

In the world of Edomae sushi, it is a traditional sushi topping on par with kohada (gizzard shad) and anago (conger eel). Besides tempura, clear soup, and tamago-toji (cooked with beaten egg), it can be enjoyed in a wide range of preparations such as tsukudani, sunomono, and rice cooked together with it. However, because it is a fish that inhabits freshwater areas, caution against parasites such as Metagonimus yokogawai and Gnathostoma is essential, and the utmost care is required when eating it raw.