‘Disco clams’ were recently caught on camera 'partying' on the ocean floor while producing their own strobe light effects.
And now one scientist, who first came across the entertaining mollusc four years ago, has discovered the secret of how it lights up.
Ctenoides ales, dubbed disco clams because of this unique feature, produce the effect using its lips - which is packed with tiny spheres of reflective silica - like a mirror ball.
Lindsey Dougherty encountered the two-inch clam in 2010 while diving with her mother and sister in Wakatobi, Indonesia.
She saw Ctenoides ales roll the edge of its mantle - a layer of muscle and tissue that acts like a cloak over the mollusc's body - and produce a strobe-light effect using its mirrored lips.
She found that the flashing was not a form of bioluminescence, which is a chemical reaction inside animals like plankton that produces light similar to that of a glow stick.
Instead, she found, the edge of the clam's mantle lip is highly reflective on one side.
When the clam unfurls its lip - typically twice a second - the millimetre-wide mirror is revealed and reflects the ambient light, like a disco ball.
The inside of the clam's lip is packed with tiny spheres of silica, only 340 nanometers in diameter, that are ideal reflectors, particularly of the blue light that penetrates deeper into seawater compared to red light.
The outside of the lip contains no silica nanospheres, so when the lip is furled, no light is reflected, according to the study, published in the British Journal of the Royal Society Interface.
By repeatedly unfurling and furling the lip, the clam produces a continual rippling light show.
The non-reflective back of the lip strongly absorbs blue light, so it appears dark and makes the contrast between the sides even more striking.
0 Comments