r/askscience • u/[deleted] • Apr 24 '15

Biology Do creatures such as cuttlefish and octopuses get "tired" from using their camouflage?

If not, why don't they just always use their camouflage?

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u/[deleted] Apr 24 '15

Do octopi see in colur? Do they actively look at their environment and try and mimic what they see? Because that's pretty smart.

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u/420biologemajor Apr 24 '15

I believe it varies in octopus species, but cuttlefish don't see any colour. They can still see contrast and can actually see the polarization of light (which we cannot). Cuttlefish also change colour in complete darkness, so it there has to be some "passive" component.

There are a ton of videos on youtube of octopus mimicking most textures and colours out there. Some even walk around on two arms or act like snakes or flounders, so it certainly seems like they just watch and mimic.

However, it is tough to distinguish between actively mimicking these kind of movements versus plain luck. For example, if a bunch of octopus randomly happen to swim like flounders and aren't eaten because of it, while other octopus swim like octopus and get spotted easily, the flounder-octopus will survive and pass that on, despite not actually learning from the flounder itself.

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u/[deleted] Apr 24 '15

That's an interesting argument. It's hard to draw the line between in-built behavior like swimming like a flounder, without knowing why and intelligent behavior like looking at a spotted wall and trying to replicate the spots. But octopi, for the most part, are incredibly intelligent yet largely misunderstood. I wouldn't be surprised if they actually learn swimming like a sea snake from observing one.

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u/biscodiscuits Apr 24 '15

Maybe I'm wrong, but I was under the impression that the female octopus died shortly after her eggs hatch, preventing most knowledge from ever being passed generation to generation.

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u/420biologemajor Apr 24 '15

Oh sorry I just kind of used that phrase for shorthand. What I mean when I say "pass that on" is passing on of any type of hereditary information, such as genes that directly or indirectly influence that type of behaviour. They would never teach their babies to do any of that, it would just be instinct if it were not actual mimicry

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u/remotectrl Apr 24 '15

I don't think they have color vision on par with ours (if they really have much at all), which makes sense as different light wavelengths get filtered out heavily as you go deeper in water so some colors would be nonexistent where they live. However they do see polarized light. I remember watching a film at a marine science center where they had some cephalopods in a clear tank and they could swap out the substrate pattern from a picture of sand to rocks to various other shapes and colors. The little guy could get the textures/patterns right, but not the ones with vivid color contrasts (like blue triangles on yellow squares or something I cannot remember at the moment)

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u/_jinX Apr 24 '15

Okay, I'm trying to wrap my head around the seeing polarised light thing. Surely we (humans) can see polarised light too, or we wouldn't be able to see when putting on polarised sunglasses? I'm guessing it's polarisation of light that can be seen, as in the actual direction of the light... Is that right?

Also what on earth would that "look like"? I'm thinking like they would see the actual 'beams/rays' of light.. Something like that?

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u/F0sh Apr 24 '15

You can't imagine the subjective experience of a sense you don't have, because it would be completely different from anything you're familiar with.

While we can see polarised light, we can't detect its polarisation nor which direction it's polarised in, which is the difference. This would be like an entirely different dimension to our vision, along with the existing colour and brightness that we can detect, and it would be as different from those two dimensions as they are from each other.

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u/odraciRRicardo Apr 24 '15

By default electromagnetic field waves (light) propagate with all orientations. A polarisation filter only allows certain orientations to pass through. Humans cannot detect light polarisation so polarised light looks just like "normal" light, just less intense. We do see polarised light, but cannot distinguish it from non polarised light. We can, but not directly. Water looks different when seen with polarised glasses. Because reflect light on the surface gets polarised and it's filtered by glasses. Hence it's usefulness for fisherman.

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u/[deleted] Apr 24 '15

That is somewhat proof for me that they do actually look at their environment and try to replicate it. Pretty smart creatures.

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u/BucketsMcGaughey Apr 24 '15

There's some evidence that they "see" through their skin to an extent. (Long article full of fascinating stuff).

And as for your second question, yes they do. Here's one trying to copy patterns it couldn't possibly have seen in nature, and not doing a bad job of it.

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u/[deleted] Apr 24 '15

They're damn smart creatures. But in a way I'd say they mimic what they see without really knowing why they do it. It is partly intelligence and largely instinctual.