Cousins of the famous Piranha, South American Pacu can grow to around a meter in length. They have blunt, human-like teeth, which they use to feed on fruit, nuts, and vegetation, and occasionally small fish and vertebrates. They are found in freshwater across South America, including the Amazon basin. Here, they are beneficial to their environment, as their herbivorous diet aids in seed dispersal.

The National Zoo & Aquarium is home to 4 South American Pacu.