How can certain camouflaging octopi and squid emulate their surroundings as close as they do?


I tried to look around this sub for a similar question and cannot see one, but I’m really curious how it works.

In: Biology

I can only answer on a cellular level: the skin cells of the octopus/squid have little packets of pigment stored within the cells. When the squid wants to change color, its brain sends a signal to these cells, which directs some proteins to transport these packets from the interior of the cell to the exterior (cell plasma membrane).
The packets fuse with the membrane and the pigments are exposed to the outside. As cells across the skin perform the process together, the squid appears to change color.

To change back, the process is reversed and the pigments are pinched back into their packets and stored away to be reused.

This is what I want to know. How does a flounder, which doesn’t even have any freakin eyes on one side, know what the surface under its blind side looks like to match it? Does it feel differences in color as heat or wavelengths or something?

Cant ELI5 it as im not ocean expert, but my best guess is simply eye sight. I remember reading that octopi/similar can see in a few more wavelengths and ways than we can, so its entirely possible they “see” things that we cant yet that help them form their camouflage correctly. I’d also add that genetic and evolutionary memory is entirely possible, where as the body retains what patterns worked with what, and what didnt. Kind of similar the way they can open complex items like jars etc, once its learnt, the cephalopod can re-use that “memory bank” information to recreate it anytime it needs to.

[This]( Seems to suggest that their skin has light receptors as well as in their eyes. After skimming the article, I think it says that they likely gather most info about the light, colour, pattern, etc from their eyes, but their skin is also used in conjunction to also sense and add to the picture of their surroundings. It also says relatives like clams and muscles also sense light with their skin.