【Reading】えぞぼら

【English Name】Wrinkled Neptune

The representative whelk handled in the market as "ma-tsubu" is Neptunea polycostata (ezobora). The crunchy, springy mouthfeel when made into nigiri sushi or sashimi is its appeal, and it draws steadfast support from sushi lovers. The main fishing method is the whelk basket (tsubu-kago), and individuals landed in the Sea of Okhotsk off Hokkaido and Sakhalin account for the bulk of distribution.

Its habitat is limited to the seabed at depths of 50 to 200 meters, in the cool waters facing the Sea of Okhotsk. The shell reaches a maximum of about 15 cm, and it is also characteristic that females grow larger than males. A carnivorous predator, it uses a long, tubular proboscis to feed on benthic animals such as polychaetes, bivalves, and sea squirts.

The most important point in handling it as an ingredient is removal of the salivary gland. The salivary gland contains tetramine, and eating it with insufficient removal can cause poisoning symptoms such as headache, dizziness, an intoxicated feeling, and unsteady gait roughly 30 minutes to 1 hour later. According to information released by the Ministry of Health, Labour and Welfare, recovery proceeds within a few hours, and there have been no fatal cases.

In classification it belongs to the genus Neptunea in the family Buccinidae, and is a species described by Scarlato in 1955. There are also reported cases of individuals with left-handed (sinistral) shells.