Firefly squid

This is a beautiful little animal with a brief and brilliant life.

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Watasenia scintillans is a small (mantle length,~6 cm; wet weight,~9 g), luminescent deep-sea squid, indigenous to northern Japan. Females carrying fertilized eggs come inshore each spring by the hundreds of millions, even a billion, to lay eggs in Toyama Bay (max. depth, 1200 m) and die, thereupon completing a 1-year life cycle.

Watasenia possesses numerous (~800), minute dermal light organs (photophores) on its ventral side. Other organs are scattered over the head, funnel, mantle, and arms, but none is found on its dorsal side. There are five prominent organs beneath the lower margin of each eye. They all emit a bluish light. A cluster of three tiny black-colored organs (<l mm diam) is located at the tip of each of the fourth pair of arms. They emit brilliant flashes of light which are clearly visible to the unaided eye even in a lighted room. Some of the flashes have a cadence resembling that of a terrestrial firefly flashing at night, and thus the squid is known in Japan as the “firefly squid” or “hotaru-ika.”

A billion die every year as a natural part of their lifecycle; all those glittering little creatures dying profligately—Nature is both exuberant and pitiless, it seems.


Tsuji FI (2005) Role of molecular oxygen in the bioluminescence of the firefly squid, Watasenia scintillans. Biochem Biophys Res Commun. 338(1):250-253.

Welcome to the new place!

As you’ve figured out now, I’ve joined the ranks of the many science bloggers at scienceblogs.com. The plaster’s still wet on the walls and there are a few things I still would like to see fixed up here in the new place (my rotating logos will be implemented some time—Carl Buell‘s Brontops will change now and then, pretty as it is; someday I’ll have to see what I can do to get Pirate Mode functioning here, too), but for now it’s a good clean layout and plenty of buckets to pour text into, and that’s all that really matters. Most importantly, with a team of pros managing the behind-the-scenes work and some really powerful servers to handle the pages, I’m hoping the frequent slow-downs and flailing databases of the past are now behind me. Let’s try to kick the tires and have a few hundred-thousand-visitor days to see how well it can all cope, OK?

Let me also reassure (or worry) you with one important thing: I think Seed gets it. When we were negotiating this move, one specific request was that I could be as free here to say what I want as I was on my own server, and I’m confident that that will be the case—so expect me to be as obnoxious as ever, sprinkling little bits of information on my usual abrasiveness to make it all go down smoothly. So, no changes except for the new URL, better performance, and a few quirky features that are gone but may slowly be restored…content will be the same, and there are promises of better things to come. We all win!

Of course, if there are things you really miss, or if you encounter new problems, please do let me know about them, and I’ll pass them onto the good guys who do the real work around here. I’m planning to just put my feet up and babble.