1 : The piranha seemed to make a strong impression on the former president, who described it as a “bloody-crazy fish” and “the embodiment of evil ferocity.”
2 : Researchers suspect that these barking sounds are a way they can issue a threat—red-bellied piranhas bark in the hands of anglers who catch them.
3 : Despite a reputation for attacking, piranha attacks on humans are rare. Piranhas will only attack if provoked, like sharks, wolves, and grizzly bears.
4 : The exact number of piranha species is unknown. However, estimates range between 30-60 or more species of piranha, which are all native to lakes and rivers in South America.
5 : Most adult piranhas, depending on the species, eat snakes, fish, bird fragments, and small mammals. Some species, like the black and red-bellied piranhas, cannot resist eating leaves or figs.
6 : Opportunistic piranhas can repeatedly pluck scales off the same victim for many years without killing it. Scales often grow back. In other words, they are a renewable source of food for piranhas.
7 : Piranha’s razor-sharp teeth are pretty intense and replaceable. They often lose their teeth throughout their lifetime but will replace them the same way sharks do.
8 : Piranhas swim in shoals for safety reasons, not for hunting, though it may seem like a good hunting technique since more piranhas can easily take down a larger foe.
9 : True piranhas have tricuspid teeth with a more pronounced middle crown, about 4 mm tall.
10 : Piranhas play a valuable role in the ecosystem as predators, prey, or scavengers. Their presence in the water bodies affects the distribution of other fish and wildlife species.