First 'Glowing' Sea Turtle Discovered in South Pacific

Hawksbill sea turtles (Eretmochelys imbricata) can "glow," or biofluoresce. Here, a newborn makes its way to the ocean at Forte beach in Brazil. Paulo Whitaker / REUTERS

Scientists have found the first biofluorescent, or "glowing" reptile: the hawksbill sea turtle.

Marine biologist David Gruber, of City University of New York, was filming fluorescent corals near the Solomon Islands in the South Pacific when "out of the blue, it almost looks like a bright red-and-green spaceship came underneath my camera," he tells National Geographic.

It wasn't an alien, but rather a hawksbill sea turtle, which is listed by the International Union for Conservation of Nature as critically endangered, meaning it is close to extinction.

Biofluorescence is different from bioluminescence, in which animals produce and emit their own light. Fluorescence happens when a material, like the exterior of this turtle's shell, absorb light at one wavelength and emits it at another; this effect makes it look like the animals are "glowing."

Gruber says he doesn't know what chemical makeup allows the turtles' shell to glow, or what function it might serve, but he hopes to find out.

Fluorescence is found in many other animals, such as corals, fish and insects, although Gruber says that most only fluoresce in one color, whereas the turtle boasts a beautiful pattern of both red and green lights.