Ruler Marine: Pacu
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 has pointed, razor-sharp teeth in a pronounced underbite, whereas pacu has 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.
Native Distribution and Habitat
Pacus are native to tropical and subtropical South America. They inhabit rivers, lakes, floodplains, and flooded forests in the Amazon, Orinoco, São Francisco River, and Río de la Plata Basins, as well as rivers in the Guianas. Here they form part of the highly diverse Neotropical fish fauna. Their habitat preferences vary significantly depending on the exact species. Several species are migratory.