<p>This <a href="http://www.fishbase.org/summary/853">chain catshark</a> dwells in the dark night of the deep sea. But without a yellow filter to block out blue light—which some biofluorescent fish have—these neon colors would be invisible.</p>

Catshark

This chain catshark dwells in the dark night of the deep sea. But without a yellow filter to block out blue light—which some biofluorescent fish have—these neon colors would be invisible.

PHOTOGRAPH BY DAVID GRUBER AND VINCENT PIERIBONE

Like The "Glowing" Sea Turtle, These Animals Also Light Up

Sharks, fish, corals, and now sea turtles all have the ability to shine for those with the right equipment.

A hawksbill sea turtle that can light up like a neon Christmas tree is the latest addition to a menagerie of animals with an ability known as biofluorescence.

These luminous animals can reflect the blue light hitting a surface and re-emit it as a different color—the most common being green, red, or orange. Biofluorescence is different from bioluminescence, where animals either produce their own light through a series of chemical reactions, or host other organisms that give off light.

People don't really think about the importance of light in the ocean, only a small portion of which is sunlit, John Sparks, curator of fishes at the American Museum of Natural History in New York City, said in a

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