Doing the lobster rock

By BBC News Online's Helen Briggs

The lobster makes a screeching sound using the same mechanism as the violin, scientists in the United States have discovered.

The creature, which belongs to the family of spiny lobsters, or crawfish, scrapes the fleshy ends of its tentacles against its hard shell.

You could certainly have a lobster orchestra but it wouldn't sound very beautiful

Sheila Patek

But rather than creating sweet music, the denizen of the deep emits an ugly rasping noise that deters sharks and other predators seeking a tasty snack.

Biologists say it is a novel underwater sound system that has not been found before in the animal kingdom.

Good vibrations

"It's the same frictional mechanism that works both in the lobster and the violin to generate vibrations," said Sheila Patek of Duke University, Durham, North Carolina.

She said that the sound made by the lobster is akin to running a finger over a balloon, or a bow over a string. Friction causes the bow to stick, then slip, generating vibrations and producing sound.

Sheila Patek studied the lobsters using an underwater microphone. Image: Duke University

"It's not a beautiful violin-like sound," she told BBC News Online. "You could certainly have a lobster orchestra but it wouldn't sound very beautiful."

Dr Patek studied the spiny lobster using an underwater microphone and tiny sensors attached to the muscles of its antenna.

The sound is generated by a fleshy "plectrum" on the lobster's tentacles and file-like plates covered in microscopic ridges just below its eyes.

Dr Patek says the lobster's novel sound system is probably crucial to its survival. Normally, the creature is protected by a hard shell. But when it moults, its soft parts are vulnerable to attack.

In contrast, the lobster's clawed relative makes its own distinctive buzzing noise by contracting the muscles in its head. And insects such as crickets make a noise more like a washboard than a violin, by rubbing a hard plectrum over large ridges.

The new research is published in the journal Nature.

Image courtesy of Natural History Magazine/Sally Bensusen.