Mystery of the shining fish -- solved at last!

Look at that handful of shiny new coins before they blong! into the soft drink machine. From quarters to cars, people admire things that shine. While bright, shiny objects are just pretty to humans, they are lifesavers for fish.

Ever notice that cool, shimmering shine of fish scales in aquarium fish or in the supermarket case" Fish use that metallic shimmer when they swim up to the surface. It dazzles and distracts seagulls and perhaps other fish that are looking for dinner.

Scientist Lia Addadi and her team now have discovered the secret of that shine. Researchers already knew that fishes’ shine comes from crystals built right into their skin! Stacked on top of each other like tiny pancakes, these layers of crystals reflect light with a glimmering glow. It helps camouflage the fish as they swim in shallow water.

However, scientists could not figure out the exact shape of these crystals or how they work.

Addadi’s team removed a batch of crystals from the skin of the Japanese Koi fish, which look like big gold fish. The scientists used X-rays to see right into the crystals and figure out their shape and structure. Addadi was surprised to find that the crystals were arranged in a pattern nobody expected. That pattern is the secret of fish shine. With this fishy knowledge, scientists may make new kinds of camouflage designs that are lifesavers for humans, especially soldiers trying to hide on the battle field.

This amazing study is in the pages of ACS’ Crystal Growth & Design, a scientific journal.

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*The research in this press release is from a copyrighted publication, and stories must credit the journal by name or the American Chemical Society. News media may obtain a full text of this report (“Biogenic Guanine Crystals from the Skin of Fish May Be Designed to Enhance Light Reflectance”) in ACS’ Crystal Growth & Design, by contacting Michael Bernstein.