New research identifies piranha species by its "bark"

The bark of a piranha can never be worse than its sting, but it could be more useful, according to new research. A recent study of sounds made by piranhas in the Amazon revealed that their underwater "barking" can be used as effective indicators of the different species that hide in these murky waters.

Rodney Rountree, also known as "The Fish Listener", and Francis Juanes of the University of Victoria, have studied more than 70 species of fish, including four types of piranha, during the month of July 2012, in the Pacaya-Samiria National Reserve, Peru. . They auditioned over 550 captured people by gently placing them under water next to a hydrophone to record all sounds.

"In the Amazon, most habitats are very turbid and you usually can not turn off the cameras and observe the behavior," Rountree told Phys.org. "The only way to watch the fish is to catch them. Pbadive acoustics allows you to potentially locate fish only by their sounds. "

Rountree also recorded more than 641 minutes of underwater soundscapes in 22 sites of the reserve and heard similar piranha "barking" in known active tasting locations, accompanied by calls for catfish and fish. Other known prey. "When piranhas are present and feeding, they bite and bite, so the other fish make a lot of sounds," he said.

With the help of a statistical badysis, researchers could differentiate piranha species according to the model of their bark.

Although this is not the first time scientists have documented the range of sounds from carnivorous fish that contract muscles near their gas bladders, previous studies have typically been conducted in the laboratory.

Rountree and Juanes presented their research on Monday, November 5th, at the 176th Assembly of the Acoustical Society of America, held in conjunction with the Canadian Acoustical Society 2018 Acoustic Week in Victoria, British Columbia.

The researchers also hope to use their work to explain the benefits of using pbadive acoustic monitoring to supplement or even replace traditional methods of catching fish. "Often the hardest thing is to find where they are," said Rountree. "So any tool that helps you find the fish is very useful."