The red-bellied piranha, Pygocentrus nattereri, is a carnivorous freshwater fish which lives in the rivers of South America.
This rather solitary fish mainly hunts other fish, especially those that are sick or wounded, which reduces the spread of germs.
In the dry season, red-bellied piranhas often find themselves trapped in residual ponds where prey is rare. Starving, they become aggressive and band together to attack larger animals such as capybaras.
These are predators with sharp teeth.
This species is well and truly carnivorous. But in spite of its ferocious appetite, powerful jaws and sharp teeth, the red-bellied piranha never seems to have attacked humans, according to records.