How a Colour-Changing Hogfish Knows whether Its Skin Is White, Brown or Polka-Dotted

How do colour-changing animals know what colour they are? Hogfish (Lachnolaimus maximus) could shed light on the answer: scientists found that some of their skin cells contain a light-sensing protein that might help them to detect when they shift between white, reddish-brown and mottled. The cells sit directly below chromatophores — cells in which pigments can be moved around to create colours or patterns.