Camouflaged Cuttlefish: Don’t Mind Me, I’m Not Here.
Filed by KOSU News in Science.
October 14, 2011
This is Camo Week at this blog, when we celebrate varieties (hunting, eating) of camouflage, so I can’t not mention the champs: cuttlefish. Here’s why: Take this cuttlefish, who lives in a lab in Porto, Portugal…
He’s a little odd-looking, for those of you who aren’t familiar with this animal. A relative of the octopus and the squid, cuttlefish have tentacles, squishy bodies, no bones and a remarkable talent for mime. Place this guy next to a plastic underwater “plant,” and in no time, he will assume the guise of his neighbor. He will pucker his skin, splay his body, hold his tentacles, and adjust his coloration in a Marcel Marceau-like attempt to blend in. Cuttlefish can hold an attitude for 20 minutes or so. Like so:
They are so good at this, in part because they don’t have bones, but also because they’ve got big brains and a distributed intelligence that allows them to pucker, stretch and sculpt themselves in ways we can’t even remotely copy. Our skin? We do goose bumps. They choose these attitudes. This is their art. Next to them, we’re pathetic. When I was at ABC News, I got marine biologist Roger Hanlon to introduce me to one of his lab cuttlefish, who matter-of-factly disappeared before my eyes. Or tried to.
We were really hard on this cuttlefish, sticking him in an environment he’d never find at sea. Football players are used to this, but what cuttlefish has tried to blend into black and white lines arranged in parallels? None, I figure.
But look at this guy! When our lines went straight up, he gamely stuck a bunch of his tentacles right up there with them. (left image) When we angled, he angled too, using different tentacles to cover different stripes (right image).
While this is all pretty good, on their best days, cuttlefish are simply astounding. The best thing they do — and I don’t think Roger Hanlon has quite figured out how — is on sunny days when light is flickering on the shallow ocean bottom, occasionally interrupted by clouds, cuttlefish can mimic the weather!
When the light around them is changing, they don’t want to be a dark, noticeable clump, so they turn their skin into a billboard — like those screens you see around Times Square — and they pulsate lights and shadows in tune with the weather so their enemies don’t notice they’re there.
How they time their skin cells to mime the movement of sunrays through water, angle changes, passing clouds, how they can split their displays in two, broadcasting one message to the right, a different message to the left, I have no idea. But they can. Watch.
I guess if you’ve spent the last 100 million years as an unprotected, unshelled, naked lump of delicious protein surrounded by predators, you learn a thing or two about camouflage.
For more details see, Barbosa, Allen, Mathger and Hanlon, “Cuttlefish use visual cues to determine arm postures for camouflage” and Ed Yong’s excellent summary, Will all Camouflaged Cuttlefish Please Raise Their Tentacles? at Ed’s blog, Not Exactly Rocket Science. [Copyright 2011 National Public Radio]