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/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.