Quirks & Quarks

Fish Use Polarized Light to Disappear

Microscopic structures on fish skin can reflect polarized light in such a way as to camouflage them to match their background and hide from hunters

Scientists discover how some fish create a cloaking effect to avoid predators

Simulated image of fish in polarized light, with mirrored skin left, with reflective platelet skin, right (Molly Cummings)
For many years, scientists have wondered how fish, living in the open ocean, seem to be able to disappear from predators. Now a new study by Dr. Molly Cummings, a Professor in the Department of Integrative Biology at the University of Texas, Austin, has revealed the mechanism these fish have evolved to pull off their disappearing act.

The fish use microscopic structures in the cells of their skin, called platelets, to reflect the polarized light in the ocean. Also, by reflecting the light at the most common angles of predation, they match their background and become invisible to any danger.

Understanding this mechanism may have applications for underwater camouflage for navy vessels.

Related Links

- Paper in Science
- University Of Texas release
- Washington Post story
Discovery News story