EYES AND SKIN OF OCTOPUS - COMPENSATING FOR SENSORY DEFICIENCIES

Octopuses are the chameleons of the sea and can change their appearance to an extraordinary degree. Yet recent experiments, described here, show that they are almost certainly colour-blind. They blend in with their background primarily because of their neurally-controlled chromatophores, which, regulated by information from an eye sensitive to brightness, constitute a system for matching luminance. Deeper in the skin, however, there is a system of broad-band reflectors (the leucophores and iridophores). When the overlying chromatophores retract, these will automatically reflect incident light, whatever its wavelength. © 1979.