Scientist Discovers Source of Disco Clams' Underwater Light Show [VIDEO]

Scientist Lindsey Dougherty, four years after being dazzled by the disco clam, has finally discovered the source of this mollusk's underwater light show.

The secret lies in its mirrored lips, packed with tiny nanospheres of silica that serve as light reflectors.

Dougherty, a University of California, Berkeley graduate student and diving instructor, first encountered the two-inch clam in 2010 while diving in Wakatobi, Indonesia.

"I've dived with humpback whales and great white sharks," Dougherty said in a statement, "but when I saw the disco clam, I was enamored. I said then, 'I'm going to do a Ph.D. on the disco clam.'"

It didn't take her long to confirm that the flashing was not, as most people assumed, a form of bioluminescence - a chemical reaction inside animals like plankton that produces light similar to that of a glow stick. Instead, she realized the rhythmic light show came from the furling and unfurling of its highly reflective mantle lip. When the clam unfurls its lip - typically twice a second - the millimeter-wide mirror is revealed and reflects the light like a disco ball.

Even underwater the disco dance scene is impressive because the 340-nanometer-wide silica on its lips are effective at reflecting the blue light that penetrates the deep ocean.

The outside of the lip contains no silica nanospheres, so when the lip is furled, no light is reflected - allowing for flashing patterns.

Dougherty used high-speed video, transmission electron microscopy, spectrometry, energy dispersive x-ray spectroscopy and computer modeling to study the detailed internal structure of the margin of the clam's lip.

She could find no other animal that uses silica nanospheres as flashing reflectors like clam, called Ctenoides ales, does. Dougherty speculates that the clam, also referred to as the electric clam, uses its light show to attract prey (mostly plankton) or other clams as potential breeding partners, or to scare away predators.

Dougherty is currently studying the clams to find out the answer, as well as is studying their eyes - all 40 of them - to determine whether these underwater creatures can see their own disco light.

This research was published in this week's issue of the British Journal of the Royal Society Interface.