Pacu (Portuguese pronunciation):  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