Bioluminescent Firefly Squid: “Flashes of Brilliance,” bioGraphic

Solvin Zankl photo,”Flashes of Brillance,” bioGraphic.

THREE INCHES LONG, MOSTLY DEEP-WATER DENIZENS and found in Japanese waters, bioluminescent firefly squid (Watasenia scintillans) are not particularly familiar to western divers. But once a year, female fireflies come to the surface in large, nightly aggregations and put on dazzling shows of light.

“The squids’ twinkling displays have captured scientists’ attention since the early 20th century, and have helped researchers better understand the chemistry of bioluminescence,” says science writer Elizabeth Preston in “Flashes of Brilliance” on the website bioGraphic, published by the California Academy of Sciences.

And, the story features fantastic images of the fireflies by photographer Solvin Zankl.


Most of the year, they live out of sight in the mid-depths, typically 600-2,000 ft./200-600 m. But after mating during their annual spring spawning season off the coast of Japan, the females rise to the surface by the millions to release their eggs for the next generation. Once released, their generation is done and many wash up on the shore.

Oh, yeah. Also, gulls, fur seals and Japanese gourmands harvest them and eat them. They’re a Japanese delicacy called Hotaru-ika.

PRINCIPAL SOURCES:Flashes of Brilliance,” biographic; “Watasenia scintillans/Oceanic Squid,”  Encyclopedia of Life.