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The narrator says that octopuses are colorblind and also says they use sight alone to camouflage based on their surroundings. How is one to reconcile these clai

The narrator says that octopuses are colorblind and also says they use sight alone to camouflage based on their surroundings. How is one to reconcile these claims with the fact that the octopuses clearly take on the color of their surroundings when they camouflage?

dm2 13y ago
It might not be a conscious decision for them. Their brain might automatically change their skin color to their surroundings, but that's a complete guess, I just can't imagine looking at something and "telling" my skin to change to that pattern and color. This article suggests that octopuses see polarized light which might be one key to mimicking color. http://io9.com/5804055/squids-and-octopuses-imitate-color-despite-being-colorblind http://io9.com/5804055/squids-and-octopuses-imitate-color-de...
beefman 13y ago
The narrator said the texture is matched by sight. It wasn't clear how the color is matched, though reflective skin spots were mentioned.
petegrif 13y ago
The narrator also said that how they did it was a mystery right now.
cgh 13y ago
I got the impression that sight is used for textural changes but colour matching is via some other mechanism that isn't well understood.
kahirsch 13y ago
There's a 3-video lecture on camouflage by Roger Hanlon (who took that video). The part about color-blindness is in part 2, here[1]. [1] http://www.youtube.com/watch?v=mtIiSXRv5no&t=33m23s http://www.youtube.com/watch?v=mtIiSXRv5no&t=33m23s
- adriand 13y ago
  Thanks, that is a super interesting talk! He posits one mechanism for how the octopus might be able to colour-match while being colour-blind, which is the presence of distributed light sensing pigments in the skin - a molecule for this, "opsin", can be found in the skin of cuttlefish and squid (and maybe octopi too, he didn't say). He says that although the pigment they have found for light-sensing is the same one they have found in the eye, and thus only indicates that the skin may be able to "see" a single colour (i.e. is also colour-blind), the research suggests that other pigments may exist, or that some other mechanism like refraction of nearby chromatophores (pigmented and/or light-reflecting cells) may allow those pigments to detect more than just a single colour. When I was first trying to imagine how a colour-blind octopus could colour-match itself to its surroundings, one thought I had was how a deaf person can sense sound via felt vibrations. Based on the frequency of the vibration, pitch can be inferred. In a way, that is sort of similar to what he suggests is happening with the light-sensing pigments in the skin - the information the organism requires is fed to it via its skin rather than the organs typically used for this task, the eyes.

dm2 13y ago

It might not be a conscious decision for them. Their brain might automatically change their skin color to their surroundings, but that's a complete guess, I just can't imagine looking at something and "telling" my skin to change to that pattern and color. This article suggests that octopuses see polarized light which might be one key to mimicking color. http://io9.com/5804055/squids-and-octopuses-imitate-color-despite-being-colorblind http://io9.com/5804055/squids-and-octopuses-imitate-color-de...

beefman 13y ago

The narrator said the texture is matched by sight. It wasn't clear how the color is matched, though reflective skin spots were mentioned.

petegrif 13y ago

The narrator also said that how they did it was a mystery right now.

cgh 13y ago

I got the impression that sight is used for textural changes but colour matching is via some other mechanism that isn't well understood.

kahirsch 13y ago

There's a 3-video lecture on camouflage by Roger Hanlon (who took that video). The part about color-blindness is in part 2, here[1]. [1] http://www.youtube.com/watch?v=mtIiSXRv5no&t=33m23s http://www.youtube.com/watch?v=mtIiSXRv5no&t=33m23s

adriand 13y ago
Thanks, that is a super interesting talk! He posits one mechanism for how the octopus might be able to colour-match while being colour-blind, which is the presence of distributed light sensing pigments in the skin - a molecule for this, "opsin", can be found in the skin of cuttlefish and squid (and maybe octopi too, he didn't say). He says that although the pigment they have found for light-sensing is the same one they have found in the eye, and thus only indicates that the skin may be able to "see" a single colour (i.e. is also colour-blind), the research suggests that other pigments may exist, or that some other mechanism like refraction of nearby chromatophores (pigmented and/or light-reflecting cells) may allow those pigments to detect more than just a single colour. When I was first trying to imagine how a colour-blind octopus could colour-match itself to its surroundings, one thought I had was how a deaf person can sense sound via felt vibrations. Based on the frequency of the vibration, pitch can be inferred. In a way, that is sort of similar to what he suggests is happening with the light-sensing pigments in the skin - the information the organism requires is fed to it via its skin rather than the organs typically used for this task, the eyes.