Lobsters Make Noise Like Violins
May 9 -- The spiny lobster may not make a pretty sound, but it uses the same tools violinists use to play beautiful concertos, a new study finds.
The lobsters are known for their spine-encrusted antennae and the way they migrate in long, single file lines along the ocean floor. But new research shows the crustaceans are also unique for the way they use the biological equivalent of a violin to make a far-from-harmonic, raspy sound.
"When you rub a bow over a violin, the sound is produced by frictional interaction between the two surfaces," explains Sheila Patek, a Duke University post doctorate researcher who authored a study about the crustacean's noisemakers published in Thursday's edition of Nature magazine. "Lobsters also have a bow and a string. They're just not resonant."
In place of a gut string bow, the lobster has a nub of tissue called the plectrum. This soft tissue rubs over the soft surface of a fleshy file just below the lobster's eye. The sticking and slipping motion over microscopic ridges on the file provides the lobster with its caustic sound.
The sound not only resembles the violin's mechanisms, it's also created in the same way that rubbing a wet thumb over a balloon makes a squeak or the moving parts of a squeaky door hinge creak.
Patek suspects the spiny lobsters don't use the noise to communicate — as she says, "We don't even think they have ears." Spiny lobsters hear only at close range using sensory hairs. Instead Patek thinks the noise is intended to discourage a predator such as a grouper or a shark from eating the animal.
"It's like you were going to eat a sandwich and just before you bit it it makes a loud noise," explains Patek. "That might give you pause."
Stick Scraping and Head Clicking
The spiny lobster's noisemaking device is the only one of its kind to be detected in any animal, says Ron Hoy, a professor of Neurobiology and Behavior at Cornell University. Many other animals, such as crickets, produce noise by scraping a hard pick over a rough-edged file. The effect generates pulses of sound, much like a stick scraping over a washboard.
