Friday Squid Blogging: Hawaiian Bobtail Squid

This squid has a light-producing organ on its underside powered by luminescent bacteria, possibly making it less noticeable from below.

Posted on November 9, 2007 at 4:02 PM • 9 Comments

Comments

Short John SilverNovember 9, 2007 6:01 PM

"possibly making it less noticeable from below"

Noooooo! It's for cruising along just above the seafloor late at night, with the boombox in its ass pumped up so high that the corals crumble!

GretchenNovember 9, 2007 8:15 PM

Oh thank goodness for a squid post. My Friday just isn't complete without one. ;-)

GretchenNovember 9, 2007 8:18 PM

I'm serious. I thought you were too busy to post one and I was disappointed! You don't realize how much you take for granted the little pleasures of your life until they aren't there.

Chris SNovember 10, 2007 1:33 AM

Hatchetfish use a similar trick. These pictures http://www.lifesci.ucsb.edu/~biolum/organism/... are ok, but even better would be pictures from below. I've seen video, and it is extremely cool - parts of the hatchetfish almost disappear into the glow from above. With the silhouette broken up, predators have a much harder time finding the fish. This http://bricker.tcnj.edu/micro/le9/... appears to be a "night" photo of this squid.

Interestingly, tests of this were done by the military years ago (without knowing about either the squid or the hatchetfish, I expect) by painting and lighting the bottom of aircraft to match the illumination from the sky. Even vehicles that might be skylined on a ridge can be camouflaged with lighting to match the sky behind them.

JuergenNovember 10, 2007 3:11 AM

This kind of counter illumination is common for deep see squid, they are quite good at it. They match the wave length of the blue light deep in the water and even regulate the intensity based on the amount of light coming down
(see Cephalopod Behaviour by Hanlon and Messenger).

The unusual thing about this squid is that it uses different proteins for reflecting the light.

Terry ClothNovember 10, 2007 10:18 AM

@Short John Silver:

Close, but no boom box. They're using the luminescence as a flashlight to search the bottom for food.

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