This illustration was made by Citron You must credit this : Citron / C · CC BY-SA 3.0Red-bellied piranha
Pygocentrus nattereri
Red-bellied and sharp-toothed, more feared than dangerous, but worth respecting.
What it is
A deep-bodied fish with a reddish belly and very sharp triangular teeth, it lives in slow rivers, lagoons and marshes and eats fish, carrion and invertebrates, often in groups. Serious attacks on people are rare. Even so, bites do happen at freshwater beaches in summer, especially when water levels drop or when food or fishing scraps are in the water.
Did you know…?
In January 2023, six swimmers were bitten at the beach of the Laguna Blanca resort (San Pedro), and the managers used nets to remove fish from the swimming area.
Where
Rivers, lagoons and marshes throughout the country. At freshwater beaches, swim in designated areas and follow local advice.
Researched and reviewed in September 2026 with 3 sources. A second reviewer checked dates, coordinates and lodging. Hours and prices may change.