helluva cephalopod
September 2, 2011 7:50 AM   Subscribe

And I say to myself... what a wonderful (underwater) world.

Obligatory link to one of my all time favorite songs at Metafilter Music: Cephalopod.
posted by flapjax at midnite (21 comments total) 26 users marked this as a favorite
Now there's a superpower worth having.
posted by chavenet at 7:57 AM on September 2, 2011

You call that an ink defense? (couldn't resist)
posted by jeffburdges at 8:05 AM on September 2, 2011 [1 favorite]

Pretty amazing.
posted by weapons-grade pandemonium at 8:06 AM on September 2, 2011

So they're colorblind, which I did not know... but they can match their color to their surroundings.


posted by curious nu at 8:09 AM on September 2, 2011 [1 favorite]

Oh noes! Now that song is stuck in *my* head again. Thanks flapjax.
posted by lothar at 8:31 AM on September 2, 2011 [1 favorite]

Double, but that was a long time ago, and the main link is dead.
posted by MrMoonPie at 8:33 AM on September 2, 2011

Cephalopodophile here. the unicorns of the sea.

Holy shit, they're COLORBLIND but communicate in color?! Wtf? Huh. Why would they use color then? So strange. Gifted with a language they can speak with their skin but not hear?

Ok, camouflage, skin texture change for survival but the palette of colors? Cephalopods change colors according to the environment and to communicate with other cephalopods. I call bs on cephalopods being color blind. No way. I know it's been proven scientifically that they are color blind. But I don't believe that is true or the full truth.

Scientists say it's the iridophores that help the cephalopods make the changes in color but I think there must be some other form of visual molecules, other than chromatophores and iridophores that scientists have not discovered yet. Something more sophisticated, perhaps unique to cephalopods that make them not color blind but super color visual. Guess it's the rhabdomeres. No, must be something else.
posted by nickyskye at 8:47 AM on September 2, 2011 [3 favorites]

How cephalopods could match colors without seeing them:

1. In the environment in which they live, certain patterns always correlate with certain colors. Say, the colors of rocks and gravel on the bottom always generally look the same, and occur in conjunction with the gravelly pattern. Or the light green of a certain kind of kelp is always more or less the same light green.

2. The octopus can see the pattern, and evolves reflexive pattern and texture matching. It also does its best to match gray intensities to those of the background.

3. Now, the octopuses whose skin color cells do a better job (more or less randomly) of matching the actual colors of the background will ten to survive and reproduce more successfully. Those who match the colors worse will tend to survive less. Eventually you'll get nothing but octopuses that match colors perfectly, despite still not being able to see them.

I can think of two predictions this hypothesis makes that would be testable, in theory. One is that color matching in cephalopods should be genetically linked. Figure out if that's true. The other is that moving a species to an environment with different color patterns on similar textures should throw off that individual's ability to color-match. That seems to be the case in nickyskye's link above. It would be cool to be able to observe a population come back into equilibrium with the new environment, but that would probably take too long to observe.
posted by rusty at 8:57 AM on September 2, 2011 [2 favorites]

Another theory regarding color perception and camouflage in cephalopods might be better described as:
OMG, WTF!!!!!
posted by johngumbo at 9:00 AM on September 2, 2011 [3 favorites]

Pretty amazing.

I prefer a simple, "Wow!"
posted by philip-random at 9:02 AM on September 2, 2011

flapjax at midnight, I love you! I would have your child for posting this if I could.

My son is researching just this stuff right now. He is going to explore the colorblindness of squids and their ability to camouflage themselves as his high school science fair project this year. What he wants to do is find out what stimulus leads them to change color (difficult, as lots of things seem to, and it doesn't seem to be fear, as they can ink you), then inhibit that stimulus (almost impossible) and see if the squid can still work around that to camouflage itself (I'm betting yes. Cuttlefish are awesome).

One of the roadblocks to his research has been finding information on the composition of the ink squids use, because whenever he looks the ink up he gets recipes, as the Japanese consider it a delicacy in their part of their world.

curious nu: "So they're colorblind, which I did not know... but they can match their color to their surroundings.



I know, when my kid told me that I had the same reaction! What? No. Really?!
posted by misha at 9:03 AM on September 2, 2011

I thought this was going to be the one where it steals the dude's camera.
posted by cjorgensen at 9:03 AM on September 2, 2011

I registered cuttleflesh.com after I saw the original camo video several years ago. Someday I'm gonna make something appropriate (or really inappropriate) out of it.

The interview adds a ton of value to this stuff. Thanks!
posted by DigDoug at 9:04 AM on September 2, 2011

Oh, and one thing considered while he was brainstorming was putting each of his squid in a small tank (just during the observation-and-record part of the experiment) in which all of the tank's sides have been patterned and possibly textured differently, to see how the squid's camouflage reacts to that quandary.
posted by misha at 9:05 AM on September 2, 2011

I love this. Thanks!
posted by widdershins at 10:29 AM on September 2, 2011

Wouldn't first contact be fun if the aliens we meet communicate in color and texture patterns evolved from defensive camouflage strategies instead of noises? Star Trek-style universal translator my ass, it's not going to be Darmok and Jalad, it's going to be tree color and gravel pathway texture.
posted by fnerg at 11:02 AM on September 2, 2011 [2 favorites]

You know I'm not really an elephant but a grand piano, do you?
posted by Namlit at 11:02 AM on September 2, 2011

I wonder if the experiments showing lack of color vision in cephalopods (thanks for digging up that link, nickyskye) ran afoul of the quirks of our color vision. This page* summarizes the complex and slightly bizarre physiology of human color perception, which involves not only cones with different wavelength sensitivities but also significant neural processing. So the marine biologists made checkerboards using pigments that looked like nice bright green, yellow and blue to us humans, but maybe those pigments appeared quite different to a cephalopod.

(I've had the weird experience of measuring the UV/Vis absorbance spectra of two solutions which were obviously a totally different color - bright pink and bright blue - and not being able to find a wavelength that could differentiate the two in a single number. It was as plain as day to the naked eye that they were different colors, but the absorbance spectra were surprisingly similar. Maybe cephalopods also do some neural processing jiggery-pokery.)

*I'm sure I first saw it on MeFi but I couldn't find the link, so my apologies to the original linker.
posted by Quietgal at 1:01 PM on September 2, 2011 [1 favorite]

Nice post. Ta.
The music's great too, but I'm still in love with the track that starts a minute in to this Previously
posted by Dub at 8:38 PM on September 2, 2011

You call that an ink defense? (slightly nsfw)
posted by sebastienbailard at 10:34 PM on September 2, 2011

posted by the_very_hungry_caterpillar at 12:48 AM on September 3, 2011

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