Camouflage-Coloration Components
Chromatophore
The outermost layer of a cephalopod's skin allows the animal to change color. It's full of chromatophore, consisting of pigment-containing sacs that have dozens of radial muscles attached to its periphery. These muscles are neural controlled, and nerves connect the chromatophores directly to the animal's brain, so the creature doesn't have to rely upon hormones or some other signaling mechanism in order to change color. The pigment sac increases or decreases in area in less than a second by contracting and relaxing the chromatophore muscles. By selectively expanding and retracting distinct groups of chromatophores, cephalopods can produce an array of patterns, such as bands, stripes and spots. It is interesting to note that many deep water forms of cephalopods possess fewer chromatophores as they are less useful in an environment in little or no light.