Pygocentrus nattereri
Red-bellied piranhas are schooling fish of South American rivers, famous for their sharp teeth and feeding frenzies — myths that exaggerate their danger to people. They actually scavenge and hunt mostly small fish, and schools provide defence against predators such as caimans, river dolphins, and cormorants. During the flooded season they spawn among vegetation, and their jaws deliver a bite with considerable force for their size.