A graduate student from Berkeley has discovered the secret workings of the disco clam’s previously inexplicable light show.
Disco clams, also known as the Ctenoides ales, live in tropical regions of the Pacific, clustering inside reef crevices. They are known for producing flashing underwater light shows, which it has now been discovered have nothing to with bio-luminescence — the process in which light is produced by living organisms due to a chemical reaction.
One side of the edge of the clam’s lip is very reflective and when it unfurls it — around twice every second — the lip reflects any ambient light in the same a mirror ball does. The clams live at between three and 50 meters under water where light is dim and blue-green, but the silica is an ideal reflector of the blue light that penetrates these deeper waters, so the light show can continue even in the semi-darkness.
Why do the clams flash at all? They are either trying to attract prey or breeding partners, or maybe they are scaring away predators.[More.](http://www.wired.co.uk/news/archive/2014-06/25/disco-clams)