Fish Skin Doesn't Just Reflect Light – It Might Actually Sense It

A preprint study suggests cobalt silverside fish skin may actively respond to light, not just reflect it.

In Hypoatherina tsurugae, iridophore cells shifted their light-reflecting state when directly illuminated, especially by blue light.

The effect points to a possible light-sensing role in fish skin structures, potentially involving guanine crystals and opsins.

If confirmed, the findings could broaden understanding of fish coloration, signaling, camouflage, and photoreception.