Piaractus brachypomus | |
---|---|
| |
Adult Piaractus brachypomus at Aquarium du palais de la Porte Dorée | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Characiformes |
Family: | Serrasalmidae |
Genus: | Piaractus |
Species: | P. brachypomus |
Binomial name | |
Piaractus brachypomus (G. Cuvier, 1818) | |
Synonyms | |
Piaractus brachypomus also known as the red-bellied Pacu or pirapitinga, is a large species of pacu, a close relative of piranhas and silver dollars, in the serrasalmid family. [1] [2] It is native to the Amazon basin in tropical South America, but it formerly included populations in the Orinoco, which was described in 2019 as a separate species, P. orinoquensis . [3] Additionally, P. brachypomus is widely farmed and has been introduced to other regions. [4] In South Florida they are invasive in rivers, canals or lakes. [5]
As with a number of other closely related species, P. brachypomus is often referred to as the red-bellied pacu in reference to the appearance of the juveniles. This has resulted in a great deal of confusion about the nature and needs of all the species involved, with the reputation and requirements of one frequently being wrongly attributed to the others. [6]
In general, its behavior resembles that of the closely related tambaqui (Colossoma macropomum). It is migratory, but the pattern is poorly understood. [7] Spawning occurs at the beginning of the flood season between November and February. [8] Larvae of the Red-Bellied Pacu are found in whitewater rivers, but adults mainly live in flooded forests and floodplains of various river types, including those of both nutrient-rich and nutrient-poor. [7] Unlike the tambaqui, the Red-bellied pacu also occurs in the headwaters of nutrient-poor rivers (not just in the lower sections). [7]
It mainly feeds on fruits, seeds, and nuts, but it is opportunistic and will also take zooplankton, insects, crustaceans and small fish, especially in the dry season. [4] [9] In general, more seeds are able to pass undamaged through the red-bellied pacu than the tambaqui, meaning that the former is overall a more efficient seed disperser. [10]
Piaractus brachypomus can reach up to 88 cm (2.9 ft) in length and 25 kg (55 lb) in weight. [2]
Juveniles have a distinct red chest and stomach, and are easily confused with the carnivorous red-bellied piranha (Pygocentrus nattereri), but the two can be separated by their teeth, which are molar-like in Piaractus brachypomus. [1] This similarity is believed to be Batesian mimicry by P. brachypomus in an attempt of avoiding predation by other species. [4] Adults lack the bright red chest and belly, and resemble the tambaqui (Colossoma macropomum), but can be separated by several meristic and morphological features: The Red-Bellied Pacu has a smaller adipose fin that lacks rays, as well as differences in teeth and operculum. [1] [11] The Red-bellied Pacu also has a more rounded head profile (less elongated and pointed). [11] [12] The other member of its genus, P. mesopotamicus , can be distinguished by its smaller scale-size [13] and the higher number of lateral scales (more than 110). [1]
The Red-Bellied Pacu supports major fisheries and based on a review by IBAMA, it was the 12th most caught fish by weight in the Brazilian Amazon in 1998 (just after the tambaqui). [7]
The Red-Bellied Pacu is often kept in aquaculture. Hybrids between this species and the tambaqui have been produced in aquaculture. [14] It can also hybridize with P. orinoquensis, but the offspring appears to be sterile. [3]