【Reading】なみがい

【English Name】Japanese Geoduck

Namigai is a bivalve belonging to the family Hiatellidae, widely known at sushi restaurants by the name "shiro-miru." Its shell length is about 10–13 cm, but the soft body is larger than the shell, and when it extends its siphon it can reach more than three times the shell length.

It has the ecology of burrowing about 30–40 cm deep into the sandy-muddy seabed and protruding the tip of its siphon above the sand to filter-feed on plankton. It is widely distributed from Hokkaido to Kyushu, with major fishing grounds in Mikawa Bay of Aichi Prefecture, Chiba Prefecture, and the Seto Inland Sea coast, and it is caught by free-diving fishing.

In sushi, the siphon portion is used as the topping, and its hallmark is a sweetness and a distinctive crisp, crunchy bite. Originally mirukui (hon-miru, the geoduck-like clam) was prized as a high-grade sushi topping, but as it became scarce due to overfishing, distribution of namigai as a substitute spread. In recent years, the catch of namigai itself has also decreased, and its price is on a rising trend. Its peak season (shun) is mainly around March to May, corresponding to the period before spawning when the flesh is full.