# Redtail catfish

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This article is about the South American redtail catfish. For the Asian redtail catfish, see [Hemibagrus wyckioides](/source/Hemibagrus_wyckioides).

The **redtail catfish** (***Phractocephalus hemioliopterus***), is a large [species](/source/Species) of South American [pimelodid](/source/Pimelodidae) (long-whiskered) [catfish](/source/Catfish). It is known in [Venezuelan Spanish](/source/Venezuelan_Spanish) as ***cajaro***; in [Guyana](/source/Guyana), it is known as a **banana catfish**, and in [Brazil](/source/Brazil) it is known as ***pirarara***,[2] a fusion of words from the indigenous [Tupi language](/source/Tupi_language): [*pirá*](https://en.wiktionary.org/wiki/pir%C3%A1) and [*arara*](https://en.wiktionary.org/wiki/arara).[3] It is the only [extant](/source/Extant_taxon) species of its genus, ***Phractocephalus***.

The redtail catfish is quite common in the [aquarium](/source/Aquarium) trade, although it is often sold in its juvenile state, only measuring a few centimeters or inches at the time of sale. Additionally, they are often sold with little to no information for novice or uninformed buyers, with vague warnings, if any, regarding the fish's massive adult size. Thus, many redtail catfish are sold and subsequently purchased as very small specimens, soon outgrowing their new aquariums—something which makes them highly unsuitable for all but the largest, usually public, aquariums (or outdoor stock tanks, pools, ponds, lakes, etc).[4] Unfortunately, many have likely been purchased when young, by uninformed shoppers, and later released by these same individuals when their true size and voracity became evident. In this way, humans have directly contributed to the species' spreading in areas outside of its natural range.

Hatchling (fry) and juvenile redtail catfish are most at-risk of being consumed by a range of predators, both aquatic and terrestrial. Larger adult specimens generally have little to fear, becoming voracious, [opportunistic](/source/Opportunism) hunters themselves. Nevertheless, at any age or size, the redtail catfish is always at-risk of being consumed by humans, [jaguars](/source/Jaguar), [giant otters](/source/Giant_otter), [Orinoco](/source/Orinoco_crocodile) and [American crocodiles](/source/American_crocodile), and [caimans](/source/Caiman), among other species.

Unlike other, bottom-dwelling catfish species, the redtail is an active swimmer, and does not lie in-wait on the river bottom to ambush passing prey. The redtail catfish is also not a picky eater, and is known for consuming anything that fits into its mouth. Meals range from other types of [fishes](/source/Fish), [crustaceans](/source/Crustacean), [aquatic worms](/source/Worm), and even [amphibians](/source/Amphibian), such as [frogs](/source/Frog), to fallen [fruits](/source/Fruit), [seeds](/source/Seed) and [tree nuts](/source/Nut_(fruit)), such as those of [palms](/source/Arecaceae) or *[Ficus](/source/Ficus)*.[5] In captivity, it has been reported that the redtail catfish will eat dry [cat food](/source/Cat_food).

## Fossil species

Although the redtail catfish is the only living representative of this genus, there are other members that date back to the upper [Miocene](/source/Miocene), and are only known from [fossil](/source/Fossil) remains. *[P. nassi](/source/Phractocephalus_nassi)* was described in 2003, from the [Urumaco Formation](/source/Urumaco_Formation) at [Urumaco](/source/Urumaco), [Venezuela](/source/Venezuela). Another fossil species, *[P. acreornatus](/source/Phractocephalus_acreornatus),* is known from the [Solimões Formation](/source/Solim%C3%B5es_Formation), [Acre](/source/Acre_(state)), [Brazil](/source/Brazil).[1][2] This genus has a minimum age of about 13.5 million years.[2]

## Description

*Phractocephalus hemioliopterus* can reach about 1.8 m (5.9 ft) in length, and about 80 kg (180 lb) in weight.[6] However, this is exceptionally rare, and most do not approach this size. They average 42-54 in ftin m in length. These colorful large catfishes have a brownish back, with yellow sides, and characteristic orange-red [dorsal fin](/source/Dorsal_fin) and [caudal fin](/source/Caudal_fin) (hence the common name). Sometimes the dorsal, pelvic and anal fins are also red. They have a broad head with long whiskers, dark black body and white underneath that extends from the mouth to the caudal fin. It has a pair of barbels on the upper jaw, and two pairs on the lower jaw. Their whiskers are sensitive and have chemical reception cells which are used as the sense of smell. They breed using external fertilization after laying their eggs. They communicate by making a clicking sound to warn off potential dangers.[5]

## Distribution and habitat

The redtail catfish is native to the [Amazon](/source/Amazon_basin), [Orinoco](/source/Orinoco), and [Essequibo](/source/Essequibo_River) river basins of South America, in [Ecuador](/source/Ecuador), [Venezuela](/source/Venezuela), [Guyana](/source/Guyana), [Colombia](/source/Colombia), [Peru](/source/Peru), [Suriname](/source/Suriname), [Bolivia](/source/Bolivia), and [Brazil](/source/Brazil).[2] It is found only in [fresh water](/source/Fresh_water), and inhabits larger rivers, streams, and lakes.[7][4] They eat during the evening and night and stay motionless during the day. They are bottom-dwellers and move about quite slowly. Red-tailed catfish are territorial fish.[5] Redtail catfish is also an invasive species in [Malaysia](/source/Malaysia); they are now found mostly in the [Perak River](/source/Perak_River) and [Pahang River](/source/Pahang_River).[citation needed]

## Relationship with humans

Due to the potentially large size of this species, redtail catfish are considered a [game fish](/source/Game_fish) by [anglers](/source/Angling). The current [IGFA](/source/IGFA) world-record for weight is from 2010 and belongs to Gilberto Fernandes, of Brazil, with a specimen that weighed-in at 56 kg (123 lb 7 oz).[8]

It is said that the South American tribes living in the forests do not eat the meat of redtail catfish as it is "black" in coloration.[9]

Globally, in places such as [Thailand](/source/Thailand), [Taiwan](/source/Taiwan), [Hong Kong](/source/Hong_Kong), and [Florida](/source/Florida),[10] the redtail catfish is an [alien species](/source/Alien_species) that has likely been released into local waterways by humans, similarly to other large freshwater species (like the [common pleco](/source/Common_pleco), [zebra tilapia](/source/Zebra_tilapia), or the [alligator gar](/source/Alligator_gar)).[11] In some regions, it is feared as a potential danger to human life; it is believed, by some, to be the cause of the many mysterious drownings of passengers aboard the ship *[Sobral Santos II](/source/Sobral_Santos_II)* when it sank.[citation needed]

### In the aquarium

The redtail catfish is an extremely popular fish in Amazonian-themed exhibits at [public aquaria](/source/Public_aquaria), where they are often housed with other large fish, such as *[Colossoma macropomum](/source/Colossoma_macropomum)* or pacu, and other large catfish.

Juveniles are often available as [aquarium](/source/Aquarium) fish, despite their eventual large size. In an aquarium where they may be well-fed, these fish can grow quite rapidly,[9] and require tanks of at least 10,000 L (2,600 US gal) when fully mature.[4] Weekly feeding is appropriate for this catfish; overfeeding is a common cause of death in this species.[12] It feeds heavily on live and dead fishes and other meat. Even as a juvenile of only a few inches in length, they are able to swallow many of the more common aquarium fish (such as [tetras](/source/Tetras) or [guppies](/source/Guppy)), and it is only appropriate to house this fish with other species of relatively large size. Redtail catfish also have a habit of swallowing inedible objects in the aquarium. Though these are often [regurgitated](/source/Regurgitation_(digestion)), both the swallowing and the regurgitation can present a problem for the fish, and these objects are best kept out of the aquarium.[12]

The redtail catfish has been hybridized with other fish, such as the *[Pseudoplatystoma](/source/Pseudoplatystoma)* or Tiger Shovelnose Catfish, through the use of hormones, in attempts to create a viable food fish: the Tiger Redtail Catfish. These hybrid fish sometimes make it into the aquarium hobby under a variety of common names.[12]

## See also

- [List of freshwater aquarium fish species](/source/List_of_freshwater_aquarium_fish_species)

## References

1. ["*Phractocephalus* (cajaro)"](https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=251791). *Paleobiology Database*

1. Lundberg, John G. & Aguilera, Orangel (2003). ["The late Miocene *Phractocephalus* catfish (Siluriformes: Pimelodidae) from Urumaco, Venezuela: additional specimens and reinterpretation as a distinct species"](http://www.scielo.br/pdf/ni/v1n2/v1n2a04.pdf). *Neotropical Ichthyology*. **1** (2): 97–109. [doi:10.1590/S1679-62252003000200004](https://doi.org/10.1590/S1679-62252003000200004)

1. Cunha, Antônio Geraldo da (2010). [*Dicionário etimológico da língua portuguesa*](https://books.google.com/books?id=4yiODwAAQBAJ) (in Portuguese). 4 ed. LEXIKON Editora. pp. 498–499. ISBN 978-85-86368-89-9. Retrieved 14 July 2020.

1. ["*Phractocephalus hemioliopterus* Red-tail Catfish"](http://www.seriouslyfish.com/species/phractocephalus-hemioliopterus/). *Seriously Fish*

1. ["Red-tailed catfish | the Dallas World Aquarium"](https://dwazoo.com/animal/red-tailed-catfish/). 25 November 2013.

1. ["*Phractocephalus hemioliopterus*"](http://www.fishing-worldrecords.com/scientificname/Phractocephalus%20hemioliopterus/show). *Fishing World Records*. Retrieved 9 May 2013.

1. ["Catfish, redtail (pirarara)"](https://igfa.org/member-services/world-record/common-name/Catfish,%20redtail%20(pirarara)). *World Record Search*. [International Game Fish Association](/source/International_Game_Fish_Association). 3 April 2010. Retrieved 14 July 2014.

1. Axelrod, Herbert R. (1996). *Exotic Tropical Fishes*. T.F.H. Publications. ISBN 0-87666-543-1.

1. ["Observations • iNaturalist"](https://www.inaturalist.org/observations/111972439). 18 April 2022. Retrieved 31 May 2024.

1. ["10 ปลาเอเลี่ยนในเมืองไทย ที่กำลังยึดแหล่งน้ำโดยคุณไม่รู้ตัว"](http://animals.spokedark.tv/?p=2218) (in Thai). spokedark. August 13, 2014. [Archived](https://archive.today/20160630043531/http://animals.spokedark.tv/?p=2218) June 30, 2016 at the Wayback Machine. Retrieved June 30, 2016.

1. ["PlanetCatfish::Catfish of the Month::January 2000"](http://www.planetcatfish.com/cotm/cotm.php?article_id=77). PlanetCatfish.com. 2006-05-11. Retrieved 2007-05-08.

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Adapted from the Wikipedia article [Redtail catfish](https://en.wikipedia.org/wiki/Redtail_catfish) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Redtail_catfish?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.