Cephalopods' Polyphenism

One of the most impressive features of cephalopods (octopus, cuttlefish and squid) is their ability to exhibit enormous phenotypic plasticity. This functions as a defense system against predators, as an advantage for prey hunting and as a possible means of interspecies communication. Cephalopods’ skin can change constantly in both colour and texture in a very sophisticated way.

Octopus vulgaris changing from camouflaged to conspicuous, in approximately two seconds, reacting to a diver. (image from: Hanlon R. Cephalopod dynamic camouflage. Current Biology. 2007; 17(11): R400-R404.)