Red-bellied Piranha

The red-bellied piranha is a freshwater fish native to the rivers and floodplain lakes of the Amazon basin in South America, among the best known of the piranha species due to its reputation, often exaggerated in popular culture, as an aggressive shoaling predator. It has a deep, laterally compressed body, a silvery flank and a reddish-orange belly and lower fins, along with a single row of sharp, tightly interlocking triangular teeth adapted for shearing flesh. Red-bellied piranhas typically travel in shoals for both protection from their own predators and to improve hunting success, feeding on fish, insects, crustaceans and carrion, and while genuinely dangerous feeding frenzies do occur under conditions of low water levels and scarce food, unprovoked attacks on healthy humans in normal river conditions are far less common than their fearsome reputation suggests. The species plays an important ecological role in its native river systems by scavenging carrion and controlling populations of other fish, and it has become a popular, if tightly regulated, species in the aquarium trade in some countries.