Fish sees with skin posthumously

Researchers report that reef-dwelling hogfish have light-sensitive cells embedded in their skin, allowing the animals to sense brightness and adjust their colour without relying solely on eyes. The study, published in Nature, shows this skin-based photoreception can continue to influence colour change even after death. Hogfish live in Atlantic reefs and can shift hues in milliseconds. Those rapid changes aid camouflage, social signalling and may help with temperature regulation and attracting mates.

To reach these conclusions, authors examined skin samples and whole animals under different light conditions, finding skin cells that respond directly to light and trigger pigment changes. Co-author Lori Schweikert said the animals "seem to observe their own colour transformation," highlighting how peripheral light detection can operate independently of the eyes. The findings offer new insight into how animals sense their surroundings, suggesting vision-related functions can be distributed across tissues, not limited to the brain and eyes.