The red-bellied piranha or red piranha (Pygocentrus nattereri) is a species of piranhanative to South America, found in the Amazon River Basin, coastal rivers of northeasternBrazil, and the basins of the Paraguay and Paraná. The red-bellied piranha has a popular reputation as a ferocious predator, despite being primarily scavengers. As their name suggests, red-bellied piranhas have a reddish tinge to the belly when fully grown, although juveniles are a silver colour with darker spots. They grow to a maximum length of 33 centimetres (13 in) and a weight of 3.5 kilograms (7.7 lb). The way to distinguish males from females is that the female has a slightly deeper color of red on her belly.