Speaking of firefly squid, Toyama Bay is famous. During the spawning season from March to May, millions of firefly squids rush near the coast and shine in the dark night. This is known as a rare phenomenon that is unprecedented in the world, and it is also called toyama squid at the same time as firefly squid in English. In Toyama Bay, especially from the right bank of the Joganji River to Uozu City, it is designated as a national special natural monument as the “firefly squid group sea surface”. It seems that the unique terrain of Toyama Bay, which suddenly deepens from the coast, contributes. Firefly squids live at a depth of about 200 m during the day, but they surfaced all at once at night due to spawning, and some of them were launched into shallow water and sounded like “Kyun, Kyun”, invite melancholy. In order to prevent its rapid decay and parasite worms, it can be boiled in boiling water as soon as it is landed, or it can be frozen or refrigerated and lined up in food supermarkets and fresh fish stores in the Tokyo metropolitan area, etc.
ホタルイカといえば富山湾が有名です。3~5月の産卵期には海岸近くまで数百万匹のホタルイカが押し寄せて闇夜に光り輝きます。これは世界でも例のない珍しい現象として知られており、英名でもfirefly squidと同時にtoyama squidとも呼ばれます。富山湾の中でも特に常願寺川右岸から魚津市にかけては「ホタルイカ群遊海面」として国の特別天然記念物に指定されています。海岸から急に深くなる富山湾独特の地形が寄与しているようです。ホタルイカは日中水深200m前後の所に生息していますが、産卵のため夜一斉に浮上し、中には浅瀬に打ち上げられ「キューン、キューン」という音を出して鳴いているようにも聞こえ、哀愁を誘います。腐敗が早いのと寄生虫を防ぐ為、水揚げするとすぐに熱湯で茹でるか、冷凍・冷蔵で首都圏などの食品スーパーマーケットや鮮魚店に並べられます。