Firefly Squid

Watasenia scintillans

The firefly squid (Watasenia scintillans) is a small, bioluminescent squid reaching only 7 to 8 cm in mantle length. Its body is equipped with thousands of photophores that produce intense blue light, particularly concentrated on the tips of the tentacles. Found in the western Pacific Ocean around Japan, it inhabits deep waters at depths of 200 to 400 meters during the day, migrating to the surface at night. Each spring, massive aggregations of firefly squid gather in Toyama Bay, Japan, for spawning, creating one of the most spectacular natural light shows in the ocean. The bioluminescence serves for counter-illumination camouflage and mate attraction. The Toyama Bay firefly squid spawning events draw divers, photographers, and tourists from around the world. It is the sole species in the genus Watasenia and is commercially harvested as a delicacy in Japan.