Hogfish, Lachnolaimus maximus, possess an uncanny ability to alter their skin colour, transitioning from a mottled white to a deep coral orange within mere seconds. This remarkable transformation is a survival mechanism, allowing them to seamlessly blend with their environment, evading potential predators.

But the question arises: How do hogfish ascertain whether they're truly camouflaged or starkly visible? Recent scientific discoveries provide an intriguing answer. Beneath the hogfish's dynamic, colour-changing skin lies a layer teeming with light-sensing proteins. These proteins, researchers believe, enable the fish to gauge and adjust its skin hue to match its surroundings.

Skin that sees

In 2018, a groundbreaking discovery revealed that the hogfish's skin expressed a gene for an opsin protein, akin to the proteins responsible for colour sensing in our eyes. While similar proteins have been identified in other colour-adaptive creatures like octopuses, their exact role remained a mystery.

However, the latest research, published in Nature Communications, indicates that these opsins are not in the colour-altering skin layer but reside beneath it. This unique arrangement suggests that the hogfish might be using this layer as an internal mirror, cross-referencing its skin colour with its visual perception to ensure perfect camouflage.