Hollywood has given the piranha a rough reputation as a vicious fish with a penchant for biting. But according to scientist from the University of Liège, Belgium, the piranha barks more than it bites. The team of biologists plunged an underwater microphone into a tank of captive red-bellied piranhas and listened in to the different sounds they make in different situations.
So far, the team registered three distinct noises. When piranhas enter into a confrontation they'll make a barking noise. When they're fighting for food or circling an opponent, a piranha will make short percussive drum-like sounds. And when their jaws snap at each other, a softer croaking sound is produced.The Presurfer