''Piaractus brachypomus'' also known as the red-bellied Pacu or pirapitinga, is a large species of

pacu Pacu () is a common name used to refer to several species of omnivorous South American freshwater Serrasalmidae, serrasalmid fish related to piranhas. Pacu and piranha do not have similar teeth, the main difference being jaw alignment; piranha ...

, a close relative of

piranha A piranha (, or ; ) is any of a number of freshwater fish species in the subfamily Serrasalminae, of the family Serrasalmidae, in the order Characiformes. These fish inhabit South American rivers, floodplains, lakes and reservoirs. Although ...

s and silver dollars, in the

serrasalmid The Serrasalmidae (serrasalmids) are a family of characiform fishes native to freshwater habitats of South America. They include more than 90 species. The name means "serrated salmon family", which refers to the serrated keel running along the ...

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 tributary, 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 ...

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 approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...

, 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 encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created f ...

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

South Florida South Florida, sometimes colloquially shortened to SoFlo, is the Regions of the United States#Florida, southernmost region of the U.S. state of Florida. It is one of Florida's three most commonly referred to directional regions; the two others are ...

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

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 species, introduced elsewhere. It is also known by the names ...

(''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 Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

occurs at the beginning of the flood season between November and February. Larvae of the Red-Bellied Pacu 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 foun ...

s and

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high Discharge (hydrolog ...

s of various river types, including those of both nutrient-rich and nutrient-poor. Unlike the tambaqui, the Red-bellied pacu 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 heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s and small fish, especially in the dry season. 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 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 (biology), type of piranha native to South America, found in the Amazon basin, Amazon, Paraguay River, Paraguay, Paraná River, Paraná and Essequibo Ri ...

(''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, who worked on butt ...

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 zoology and botany which relates to counting quantitative features of animals and plants, such as the number of fins or scales in fish. A meristic (countable trait) can be used to describe a particular species, or used to i ...

and morphological features: The Red-Bellied Pacu has a smaller

adipose fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only b ...

that lacks rays, as well as differences in teeth and operculum.Lauzanna, L.; and G. Loubens (1985). Peces del Rio Marmoré. . The Red-bellied Pacu 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 Red-Bellied Pacu supports major fisheries and based on a review by

IBAMA The Brazilian Institute of the Environment and Renewable Natural Resources ( Portuguese: ''Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis'', IBAMA) is a government agency under the administration of the Brazilian Minis ...

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

Brazilian Amazon Brazilian commonly refers to: * Brazil, a country * Brazilians, its people * Brazilian Portuguese, its dialect Brazilian may also refer to: * "The Brazilian", a 1986 instrumental music piece by Genesis * Brazilian Café, Baghdad, Iraq (1937) * Bra ...

in 1998 (just after the tambaqui). The Red-Bellied Pacu 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. Nelu ...

. 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. Locate ...

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