Reading a Cuttlefish's Mind — On Its Skin

(Credit: Stephan Junek) Pity the cuttlefish that tries to play poker. Where humans might blush when embarrassed or go white when frightened, cuttlefish wear their thoughts on their skins much more literally. Our own color transformations are caused by nothing more than changes in the blood flowing right under our skin, and it's a poor marker of what our actual thoughts are. Cuttlefish, by contrast, are covered in up to millions of tiny pigment-filled cells called chromatophores. Muscles in the cells stretch to reveal the colors, and it's a part of why a cuttlefish, closely related to octopuses and squid, can go from a drab brown to a perfect mimic of a coral reef in seconds.