Every year, between March and June, the 14-km shoreline of Japan’s Toyama Bay is lit up in blue. The electrifying light show isn’t man-made; it’s a natural phenomenon, caused by thousands of bioluminescent cephalopods known as ‘Glowing Firefly Squids’. These fascinating creatures normally live 1,200 ft underwater, but are pushed to the surface by waves during the Hotaru Ika (firefly squid) season.
Firefly Squid, or Watasenia Scintillans, are normally about three inches long and covered with photophores. Large photophores are present around their eyes and on the tips of their tentacles, while tiny photophores cover the entire body. These photophores contain light-producing chemicals that are responsible for the squid’s bioluminescence. Fireflies have similar photophores, so the squid are named after them.