Scientists have know for a while that piranhas produce a sound, however until now they have not known the purpose or reason behind this. Sandie Millot, Pierre Vandewalle and Eric Parmentier at the University of Liege in Belgium have been on a quest to translate the noise or often referred to as the bark of the Piranha
The trio have discovered that the piranha make three different sounds depending on their mood or behaviour and have published their results in "The Journal of Experimental Biology"
To record the sounds, the scientists used a Hydrophone which is an underwater microphone and also video recorded the fish so they could study their movements whilst they were making the sounds.
The first of the sounds they deciphered was a bark the fish produced when they "displayed" to each other, which is a form of confrontation but not an actual fight.
The other two sounds were recorded as a drum-like percussive beat, being made when they were chasing each other and also a softer croak when they were biting each other. Strange but True.