A clownfish swims through a sea anemone.
The computer-generated clownfish stars of Finding Nemo were quite the chatterboxes. It turns out that real-life clownfish talk to each other, too — although their conversations probably have less emotional baggage.
For more than 70 years, scientists have listened to the little orange-and-white fish make strange chirping and popping sounds. Now, they think they know how the fish do it.
Researchers at Virginia Commonwealth University used high-speed videos and X-rays to peer inside the noisy fish. As the fish opened and raised their mouths in a certain way, special ligaments on the jaw snapped the mouth shut, making the clownfish's teeth bang together.
"It's not like grinding teeth; I mean, it's a quick collision," says team member and biologist Michael Fine. The impact seemed to reverberate through the jaw.
Clownfish aren't the only fish that talk. A lot of species send out warnings or love songs. Some vibrate their swim bladders; others send out burbles of air.
"There are even names, of course, associated with it — like croaker, sea robins, drums," Fine says.
Those are species that are easy for people to hear. But Fine says the voices of other fish are more mysterious.
"There are groups of fishes that we don't really have any idea how they make their sounds," he says.
But now, says Fine, clownfish and their clacking teeth can be taken off that list.
The study appears in the journal Science.