Wednesday, February 23, 2011
February 23, 2011 : Clusterwink Snail
Tiny snails found on Australia’s eastern coast can flicker their spiral shells like dim, blue-green light bulbs.
Some snails excrete bioluminescent trails of snot or blink their muscly foot to attract mates. But the clusterwink snail is the first discovered to use the shell-flashing trick, which seems to have evolved as a form of self-defense.
“The snail produces light when tapped or around animals that might eat it, even while it’s hiding in its shell,” said Dimitiri Deheyn, a marine biologist at the Scripps Oceanographic Institute in San Diego. Deheyn and his colleague describe the bioluminescent trick of the snail, also known as Hinea brasiliana, in an upcoming study in the journal Proceedings of the Royal Society B.
The snail’s glow-in-the-dark-shell trick was noticed by scientists decades ago, but until now, nobody had any idea what chemicals are involved in generating the glow, or how the shell lights amplifies the light.
“Pinning down what particular biomechanism the snails use to glow is going to be important for the biotech industry,” said marine biologist Mark Moline of California Polytechnic State University, who wasn’t involved in the study.
When threatened, fingernail-sized H. brasiliana generates pulses of bioluminescent light from a single spot on its mushy body. The light pulses are variable, lasting as short as 1/50th of a second to as long as a few seconds. But the opaque shell diffuses only the blue-green color of light it generates — and no other color — like a highly selective frosted light bulb.