How the Cuttlefish Gets Its Spots

Cephalopods – particularly the octopus and the cuttlefish – are the undisputed masters of the quick change.

Their skin is packed with specialized cells called ‘chromatophores’ that change the colour or reflectivity of the skin. Each chromatophore has its own activating muscle and nerve fibre, and these are connected to a part of the brain dedicated to coordinating the complex patterns.

Although the chromatophores only contain red, yellow and brown pigments, cuttlefish can create almost any colour by combining different layers of coloured and reflecting cells.

Green, for example, is achieved by using an iridescent layer deep in the skin to scatter light back through yellow pigments, which act as a filter.

All the layers are controlled independently and simultaneously, so a cuttlefish can change its entire skin colour in less than a second.

Chameleons use a similar arrangement of skin cells but the chromatophores are controlled using hormones, rather than nerve impulses, so the change occurs more slowly.