Red-bellied piranha or Red piranha (Pygocentrus nattereri)
The red-bellied or red piranha (Pygocentrus nattereri) is a species of piranha native to South America, found in the Amazon River Basin. 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.
Photographed at the Georgia Aquarium