PACU
| Pacu | |
|---|---|
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| Large pacu (Serrasalminae) at the Shedd Aquarium | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Characiformes |
| Family: | Characidae |
| Subfamily: | Serrasalminae |
Pacu (Portuguese pronunciation: [paˈku]) is a common name used in the aquarium trade to refer to several common species of omnivorous South American freshwater 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, which are uncannily similar to human teeth, and a less severe underbite, or a slight overbite. Pacu, unlike some types of piranha, actually feed on plants and not flesh. Additionally, full-grown pacu are much larger than piranha, reaching up to 0.9 m (3.0 ft) and 25 kg (55 lb) in the wild.
Pacu is a term of Brazilian Indian/Guaraní origin. When the large fish of the Colossoma genus entered the aquarium trade in the U.S. and other countries, they were erroneously labeled pacu. In the Brazilian Amazon, the term pacu is generally reserved to smaller and medium-sized fish in the Metynnis, Mylossoma, Mylesinus and Myleus genera. The Colossoma macropomum fish are known as tambaqui, whereas Piaractus brachypomus is known as pirapitinga. In Perú, both of the species (Colossoma macropomum and Piaractus brachypomum) are called pacú and gamitana. In Rio Paraná/Paraguay there is Piaractus mesopothamicus, which is also called "pacú" in Paraguay.
Pacu, along with their piranha cousins, are a characin fish, meaning a kind of tetra, belonging to the Characiformes order. The ongoing classification of these fish is difficult and often contentious, with ichthyologists basing ranks according to characteristics that may overlap irregularly (see Cladistics). DNA research sometimes confounds rather than clarifies species ranking. Ultimately, classifications can be rather arbitrary.
Pacu, along with piranha, are currently further classified into the Serrasalminae subfamily. Serrasalminae means "serrated salmon family" and is a name which refers to the serrated keel running along the belly of these fish. However, dental characteristics and feeding habits further separate the two groups from each other.
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Wikipedia