for National Geographic News
In the same way that a child's first week of violin lessons sends the family running for earplugs, so may the spiny lobster keep predators at bay, biologists say.
There are many species of this clawless lobster throughout the world, and they are the only animals known to make noise like an orchestra of violiniststhough the lobsters' sound is much more screech than sweet music.
"It really is an intriguing mechanism," said Sheila Patek, an assistant professor at the University of California, Berkeley.
Most insects, crustaceans, and other shelled creatures make noise by rubbing a hard pick over a series of bumps or ridges, much like a person running a thumbnail across a comb or a guitarist picking at strings.
To generate their sound, the lobsters rub a soft nubcalled a plectrumfound on the underside of their antennae over a smooth file located on the side of a plate below their eyes.
The noisemaking mechanism, referred to as "stick and slip," results in a screech that, according to Patek, appears to be part of the lobsters' defense strategy against predators.
Peter Bouwma, a graduate student at Florida State University in Tallahassee who is studying the spiny lobster, said that Patek's research detailing how the sound is made is "very interesting" but that scientists are uncertain as to why the lobsters make the noise.
"We know the method now, but we don't know what the function is," he said.
Kari Lavalli is a scientist at Austin Community College in Texas and spiny lobster research collaborator with a group at Florida State University. She says spiny lobster defense mechanisms are species specific.
For example, Florida spiny lobsters (Panulirus argus), which Bouwma studies, do everything from feeding to migrating in a large group, and they employ a "collective self defense strategy when attacked," Lavalli said.
SOURCES AND RELATED WEB SITES