Science Visualized Animals

These transparent fish turn rainbow with white light. Now, we know why

Light gets diffracted by repeated structures in the ghost catfish’s muscles

A close up photo of several ghost catfish swimming on a black background while a light is shining on some of their scales which appear iridescent.

The ghost catfish (several shown) becomes iridescent when white light passes through its mostly transparent body.

Nan Shi, Xiujun Fan and Genbao Wu

By McKenzie Prillaman

The ghost catfish transforms from glassy to glam when white light passes through its mostly transparent body. Now, scientists know why.

The fish’s iridescence comes from light bending as it travels through microscopic striped structures in the animal’s muscles, researchers report March 13 in the Proceedings of the National Academy of Sciences.