Pacu vs. Piranha — What's the Difference?

Herbivorous fish with human-like teeth.

Carnivorous fish with sharp teeth.

Usually peaceful and not aggressive.

Often portrayed as aggressive predators.

Pacu (Portuguese pronunciation: [paˈku]) is a common name used to refer to several species of omnivorous South American freshwater serrasalmid fish that are related to the piranha. Pacu and piranha do not have similar teeth, the main difference being jaw alignment; piranha have pointed, razor-sharp teeth in a pronounced underbite, whereas pacu have squarer, straighter teeth and a less severe underbite, or a slight overbite.

A piranha or piraña (, , or ; Portuguese: [piˈɾɐ̃ɲɐ], Spanish: [piˈɾaɲa]), a member of family Serrasalmidae, or a member of the subfamily Serrasalminae within the tetra family, Characidae in order Characiformes, is a freshwater fish that inhabits South American rivers, floodplains, lakes and reservoirs. Although often described as extremely predatory and mainly feeding on fish, their dietary habits vary extensively, and they will also take plant material, leading to their classification as omnivorous.

Any of several South American freshwater fishes related to the piranha.

Any of various tropical American freshwater fishes of several genera, especially Serrasalmus and Pygocentrus, that have sharp teeth and are known for attacking and feeding on live animals. Also called caribe.

A South American fresh-water fish (Myletes pacu), of the family Characinidæ. It is highly esteemed as food.

(ichthyology) Any of the carnivorous or frugivorous freshwater fish living in South American rivers and belonging to the subfamily Serrasalminae.

Someone who attacks in search of booty

Small voraciously carnivorous freshwater fishes of South America that attack and destroy living animals