''Piaractus brachypomus'', the pirapitinga, is a large species of

pacu Pacu () 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 hav ...

, a close relative of

piranha A piranha or piraña (, , or ; or , ) is one of a number of freshwater fish in the family Serrasalmidae, or the subfamily Serrasalminae within the tetra family, Characidae in order Characiformes. These fish inhabit South American rivers, ...

s and silver dollars, in the

serrasalmid The Serrasalmidae (serrasalmids) are a family of characiform fishes, recently elevated to family status. It includes more than 90 species. The name means "serrated salmon family", which refers to the serrated keel running along the belly of these ...

family.Nico, L.; P. Fuller; and M. Neilson (22 October 2013)
Piaractus brachypomus.
USGS Nonindigenous Aquatic Species Database, Gainesville, FL. Retrieved 2 March 2017. It is native to the

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Bolivi ...

in tropical South America, but it formerly included populations in the

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers , with 76.3 percent of it in Venezuela and the remainder in Colombia. It is the fourth largest river in the wor ...

, which was described in 2019 as a separate species, ''P. orinoquensis''.Escobar, M.D., R.P. Ota, A. Machado-Allison, I.P. Farias and T. Hrbek (2019). A new species of Piaractus (Characiformes: Serrasalmidae) from the Orinoco Basin with a redescription of Piaractus brachypomus. Journal of Fish Biology: -x Additionally, ''P. brachypomus'' is widely

farmed Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people t ...

and has been introduced to other regions.SeriouslyFish
Piaractus brachypomus.
Retrieved 2 March 2017. In

South Florida South Florida is the southernmost region of the U.S. state of Florida. It is one of Florida's three most commonly referred to directional regions; the other two are Central Florida and North Florida. South Florida is the southernmost part of th ...

they are invasive in rivers, canals or lakes. 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.

Ecology

Piaractus brachypomus (Teffe, Brazil, 4 October 1865)

In general, its behavior resembles that of the closely-related

tambaqui The tambaqui (''Colossoma macropomum'') is a large species of freshwater fish in the family Serrasalmidae. It is native to tropical South America, but kept in aquaculture and introduced elsewhere. It is also known by the names black pacu, blac ...

(''Colossoma macropomum''). It is migratory, but the pattern is poorly understood.Araujo-Lima, C.A.R.M.; and M.L. Ruffino (2003). Migratory Fishes of the Brazilian Amazon. Pp. 233—302 in: Carolsfeld, J.; B. Harvey; C. Ross; and A. Baer (editors). Migratory Fishes of South America.

Spawning Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquati ...

occurs at the beginning of the flood season between November and February. Larvae of the pirapitinga are found in whitewater rivers, but adults mainly live in

flooded forest Freshwater swamp forests, or flooded forests, are forests which are inundated with freshwater, either permanently or seasonally. They normally occur along the lower reaches of rivers and around freshwater lakes. Freshwater swamp forests are found ...

s and

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s of various river types, including those of both nutrient-rich and nutrient-poor. Unlike the tambaqui, the pirapitinga also occurs in the headwaters of nutrient-poor rivers (not just in the lower sections). It mainly feeds on fruits, seeds, and nuts, but it is opportunistic and will also take

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

insects Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of j ...

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s and small fish, especially in the dry season. In general, more seeds are able to pass undamaged through the pirapitinga than the tambaqui, meaning that the former is overall a more efficient

seed disperser In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...

Appearance

''Piaractus brachypomus'' can reach up to in length and in weight. Juveniles have a distinct red chest and stomach, and are easily confused with the carnivorous

red-bellied piranha The red-bellied piranha, also known as the red piranha (''Pygocentrus nattereri''), is a type of piranha native to South America, found in the Amazon, Paraguay, Paraná and Essequibo basins, as well as coastal rivers of northeastern Brazil.

(''Pygocentrus nattereri''), but the two can be separated by their teeth, which are molar-like in ''Piaractus brachypomus''. This similarity is believed to be

Batesian mimicry Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, after his work on bu ...

by ''P. brachypomus'' in an attempt of avoiding predation by other species. Adults lack the bright red chest and belly, and resemble the tambaqui (''Colossoma macropomum''), but can be separated by several

meristic Meristics is an area of ichthyology and herpetology which relates to counting quantitative features of fish and Reptile, reptiles, such as the number of fins or scales. A meristic (countable trait) can be used to describe a particular species of fi ...

and morphological features: The pirapitinga has a smaller

adipose fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as s ...

that lacks rays, as well as differences in teeth and operculum.Lauzanna, L.; and G. Loubens (1985). Peces del Rio Marmoré. . The pirapitinga also has a more rounded head profile (less elongated and pointed). The other member of its genus, '' P. mesopotamicus'', can be distinguished by its smaller scale-size and the higher number of lateral scales (more than 110).

Connection to humans

The pirapitinga supports major fisheries and based on a review by

IBAMA Brazilian Institute of the Environment and Renewable Natural Resources ( pt, Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis, IBAMA) is the Brazilian Ministry of the Environment's administrative arm. IBAMA supports anti- ...

, it was the 12th most caught fish by weight in the

Brazilian Amazon Brazilian commonly refers to: * Something of, from or relating to Brazil * Brazilian Portuguese, the dialect of the Portuguese language used mostly in Brazil * Brazilians, the people (citizens) of Brazil, or of Brazilian descent Brazilian may also ...

in 1998 (just after the tambaqui). The pirapitinga is often kept in

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...

. Hybrids between this species and the

have been produced in aquaculture.Gomes, Schneider, Barros, Sampaio, Hashimoto, Porto-Foresti, and Sampaio (2012)
Innovative molecular approach to the identification of Colossoma macropomum and its hybrids.
An. Acad. Bras. Ciênc. 84(2). It can also hybridize with ''P. orinoquensis'', but the offspring appears to be sterile.

References

External links

*http://www.aquaticcommunity.com/mix/redbellypacu.php *http://www.animalplanet.com/tv-shows/river-monsters/fish-guide/red-bellied-pacu/ *http://eol.org/pages/217197/overview
Species Profile - Red-Bellied Pacu (''Piaractus brachypomus'')
National Invasive Species Information Center,

United States National Agricultural Library The United States National Agricultural Library (NAL) is one of the world's largest agricultural research libraries, and serves as a national library of the United States and as the library of the United States Department of Agriculture. Located ...

. {{Taxonbar, from=Q311732 Serrasalmidae Fish described in 1818 Taxa named by Georges Cuvier