Pacu

Pacu is a common name used to refer to several species of omnivorous South American freshwater serrasalmid fish related to piranhas. 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. Pacu, unlike piranha, mainly feed on plant material and not flesh or scales. Additionally, the pacu can reach much larger sizes than piranha, at up to 1.08 m (3 ft 6+1⁄2 in) in total length and 40 kg (88 lb) in weight. The common name pacu is generally applied to fish classified under the below listed genera. Among these, several genera contain species where commonly used English names include the word pacu, as listed.

Source: Wikipedia