Cuttlefish can change colour like chameleons

Part of the cephalopod class, the cuttlefish is a remarkable mollusc that can change its colour to protect itself against predators. Cuttlefish have a combination of cells stacked in different layers in their skin that operate in unison to produce a swift and impressive camouflage technique.

The most important of these cells are the chromatophores, which hold pigments of different colour directly under the skin. They are attached to a group of 15-25 muscles, and when the muscles contract or relax they can make a specific pigment larger or smaller, thus altering the surface colouration of the skin.

Another layer of cells, the leucophores, help the cuttlefish blend into the environment around them. These flattened and branched cells can scatter and reflect the incoming light on the cuttlefish, therefore giving the skin the same colouration as the main wavelength of light in the environment.