Beware, sushi and sashimi lovers: If you feel a sharp pain in your stomach after enjoying a bowl of raw seafood, you might have succumbed to the perils of the parasitic worm Anisakis.

The Health, Labor and Welfare Ministry has issued an official warning on the rapidly growing number of Anisakis infections linked to eating raw or undercooked fish.

Larvae of the white, string-like parasite are about 5 mm wide and up to 3 cm long. They are often found in species like mackerel, Japanese horse mackerel, salmon, saury, sardines and squid.