What continent are piranhas native to?

Piranhas are native to South America.

These freshwater fish inhabit river systems, floodplains, lakes, and reservoirs across tropical and subtropical South America. Their native range includes the Amazon and Orinoco basins, rivers of the Guianas, the Paraguay–Paraná system, and the São Francisco basin. Individual species often have much narrower distributions than the continent-wide label suggests.

Piranhas are members of the family Serrasalmidae and belong to the order Characiformes. They are closely related to pacus, which generally have deeper, more plant-oriented teeth and diets. Despite their fearsome reputation, piranha diets vary considerably: depending on the species and circumstances, they may eat fish, insects, crustaceans, plant material, carrion, or fruit.

Movies and sensational accounts often portray piranhas as routinely attacking people in vast feeding frenzies. In reality, serious attacks are uncommon, though bites can occur, especially when fish are stressed, crowded, or food is scarce during dry-season low water. Aquarium releases have produced reports outside South America, but such occurrences are introductions, not evidence of their native origin.