(National Geographic/David Gruber)
What is biofluorescence? Jane J. Lee of National Geographic explains that it's:
[...] the ability to reflect the blue light hitting a surface and re-emit it as a different color. The most common colors are green, red, and orange.
Biofluorescence is different from bioluminescence, in which animals either produce their own light through a series of chemical reactions, or host bacteria that give off light.
This property is found in some fish, crustaceans, and corals. But now, for the first time, scientists have found it in a reptile. David Gruber, a marine biologist, led a team that searched for biofluorescent creatures off the Solomon Islands. They were shocked when an Eastern Pacific Hawksbill Turtle swam into view and glowed:
The marine biologist captured the turtle sighting on a video camera system, whose only artificial illumination was a blue light that matched the blue light of the surrounding ocean. A yellow filter on the camera allowed the scientists to pick up fluorescing organisms.
Gruber followed the turtle for a short while, but "after a few moments I let it go because I didn't want to harass it." The hawksbill proceeded to dive down into the pitch-black ocean.
Later, Gruber tested his equipment on captive Hawksbill Turtles and found that they were biofluorescent, too.
-via Twisted Sifter