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==Anatomy==
==Anatomy==
[[Image:Phractocephalus hemioliopterus.jpg|thumb|left|260px|Redtail catfish in an aquarium.]]
[[Image:Phractocephalus hemioliopterus.jpg|thumb|left|260px|Redtail catfish in an aquarium.]]
The redtail catfish has a broad head with a wide mouth. Its body is primarily dark gray with small darker gray spots. The [[Anatomical terms of location|ventral]] surface is paler. A lateral white band starts at the [[caudal peduncle]] and runs [[Anatomical terms of location|anteriorly]], tapering to end anywhere from midway along the body to just behind the [[operculum]]. The caudal fin is red or orange, giving the fish its common name.
The redtail catfish has a broad head with a wide mouth. Its body is primarily dark gray with small darker gray spots. The [[Anatomical terms of location|ventral]] surface is paler. A lateral white band starts at the [[caudal peduncle]] and runs [[Anatomical terms of location|anteriorly]], tapering to end anywhere from midway along the body to just behind the [[Operculum (fish)|operculum]]. The caudal fin is red or orange, giving the fish its common name.


Upon maturity these fish can reach a length of 1.3 [[Metre|m]] (4 [[Foot (unit of length)|ft]]) [[Fish measurement|total length]]. They have been known to reach over 44 [[kilogram|kg]] (97 [[pound (mass)|lb]]).<ref name=Fishbase/>
Upon maturity these fish can reach a length of 1.3 [[Metre|m]] (4 [[Foot (unit of length)|ft]]) [[Fish measurement|total length]]. They have been known to reach over 44 [[kilogram|kg]] (97 [[pound (mass)|lb]]).<ref name=Fishbase/>

Revision as of 06:39, 28 August 2007

This article is about the South American redtail catfish. For the Asian redtail catfish, see Hemibagrus wyckioides.

Redtail catfish
Scientific classification
Kingdom:
Phylum:
Class:
Order:
Family:
Genus:
Phractocephalus

Agassiz, 1829
Species:
P. hemioliopterus
Binomial name
Phractocephalus hemioliopterus
Synonyms
  • Silurus hemioliopterus Bloch & Schneider, 1801
  • Pimelodus grunniens Humboldt, 1821
  • Rhamdia grunniens (Humboldt, 1821)
  • Phractocephalus bicolor Spix & Agassiz, 1829

The redtail catfish, Phractocephalus hemioliopterus, is a pimelodid (long-whiskered) catfish named for its red or orange caudal fin. In Venezuela it is known as cajaro and in Brazil it is known as pirarara.[1] It is the only extant species of the genus Phractocephalus. This fish originates from South America. Despite reaching a large size, this fish is a common aquarium fish.

Extinct Phractocephalus

Although the redtail catfish is the only living representative of this genus, there are other members that date back to the upper Miocene. P. nassi was described in 2003, and is from Urumaco, Venezuela. Another undescribed member is known to exist from Acre, Brazil.[1] This genus has a minimum age of about 13.5 million years.[1]

Distribution and Habitat

The redtail catfish is native to the Amazon, Orinoco, and Essequibo river basins of South America.[1] It is found only in fresh water.[2] This fish has also been introduced into Florida, but it is not established.[2]

Anatomy

Redtail catfish in an aquarium.

The redtail catfish has a broad head with a wide mouth. Its body is primarily dark gray with small darker gray spots. The ventral surface is paler. A lateral white band starts at the caudal peduncle and runs anteriorly, tapering to end anywhere from midway along the body to just behind the operculum. The caudal fin is red or orange, giving the fish its common name.

Upon maturity these fish can reach a length of 1.3 m (4 ft) total length. They have been known to reach over 44 kg (97 lb).[2]

Relationship to humans

Because of the large size this fish can reach, it is a minor game fish.[2]

It is said that the natives do not eat the meat of the Redtail catfish because it is black in coloration. [3] However, the redtail catfish has been hybridized with other fish such as the Tiger Shovelnose Pseudoplatystoma sp. through the use of hormones in attempts to create a viable food fish; these hybrid fish sometimes make it into the aquarium hobby under a variety of common names.[4]

In the aquarium

The redtail catfish is an extremely popular fish in Amazonian themed exhibits at public aquaria, where they are often housed with other large fish such as Colossoma macropomum, Arapaima gigas, and other large catfish.

Juveniles are often available as aquarium fish despite their eventual large size. In an aquarium where they may be well-fed, these fish can grow quite rapidly.[3] Weekly feeding is appropriate for this catfish; overfeeding is a common cause of death in this species.[4] 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, 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. Both the swallowing and the regurgitation can present a problem for the fish, and objects are best kept out of the aquarium.[4]

References

  1. ^ a b c d Lundberg, John G. (2003). "The late Miocene Phractocephalus catfish (Siluriformes: Pimelodidae) from Urumaco, Venezuela: additional specimens and reinterpretation as a distinct species" (PDF). Neotropical Ichthyology. 1 (2): 97–109. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  2. ^ a b c d Froese, Rainer; Pauly, Daniel (eds.). "Phractocephalus hemioliopterus". FishBase. Apr 2007 version.
  3. ^ a b Axelrod, Herbert R. (1996). Exotic Tropical Fishes. T.F.H. Publications. ISBN 0-87666-543-1
  4. ^ a b c "PlanetCatfish::Catfish of the Month::January 2000". PlanetCatfish.com. 2006-05-11. Retrieved 2007-05-08.