The black piranha, a native of the Amazon, has the most powerful bite of all carnivorous fishes, living or extinct, given their body size, according to new research.
Even at their small body sizes, diet studies indicate that piranhas will attack and bite chunks of bony fins and flesh from prey many times larger than themselves.
In spite of their fearsome reputation, no quantitative data or empirical estimates regarding the piranhas' biting abilities were available.
The first bite-force measurements taken from wild specimens of the largest species of piranha in the Amazon, the black piranha, shows this creature can bite with a force more than 30 times greater than its weight.
The new research, co-authored by Guillermo Orti, professor of biology at the George Washington University, highlights the piranhas' specialised jaw morphology, which allows them to attack and bite chunks out of much larger prey.
"It was very exciting to participate in this project, travel one more time to the Amazon to be able to directly measure bite forces in the wild," said Orti.
"I learned a lot of biomechanics from my colleagues while collecting valuable specimens for my own research."
His research focuses on the evolution of fishes in general, but specialises on Amazonian fishes, to unravel evolutionary relationships based on DNA sequence data, according to the journal Scientific Reports, a publication from Nature.
In 2010, Orti along with other researchers participated in an expedition to the Xingu and Iriri rivers in Amazonia to collect the data on the fish, according to a George Washington statement.
The expedition was organised and filmed by National Geographic.