The African arowana or Nile arowana (''Heterotis niloticus'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

of bonytongue. Despite being called an "arowana", the African arowana is more closely related to arapaimas, the only other members in the subfamily Arapaiminae, than the South American, Asian, and Australian arowanas in the subfamily

Osteoglossinae Arowanas are freshwater bony fish of the subfamily Osteoglossinae, also known as bony tongues (the latter name is now often reserved for Arapaiminae). In this family of fish, the head is bony and the elongated body is covered by large, heavy sc ...

(Arapaiminae is sometimes considered to be a separate family from Osteoglossidae). Compared to these, the African arowana has a more terminal mouth and is the only one that feeds extensively on plankton.

Description

The African arowana is a long-bodied fish with large scales, long dorsal and anal fins set far back on the body, and a rounded caudal fin. Its height is 3.5 to 5.0 times standard length. It has been reported to reach up to long and weigh up to . This fish is gray, brown, or bronze in color. Coloration is uniform in adults, but juveniles often have dark longitudinal bands. African arowanas have air-breathing organs on its

branchiae A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they ar ...

, enabling them to survive in oxygen-depleted water. A suprabranchial organ allows it to concentrate small planktonic food particles and also has a sensory function.

Range

This species is widespread throughout Africa, where it is native to all the watersheds in Sahelo-Sudanese region,

Senegal Senegal,; Wolof: ''Senegaal''; Pulaar: 𞤅𞤫𞤲𞤫𞤺𞤢𞥄𞤤𞤭 (Senegaali); Arabic: السنغال ''As-Sinighal'') officially the Republic of Senegal,; Wolof: ''Réewum Senegaal''; Pulaar : 𞤈𞤫𞤲𞤣𞤢𞥄𞤲𞤣𞤭 ...

, and

Gambia The Gambia,, ff, Gammbi, ar, غامبيا officially the Republic of The Gambia, is a country in West Africa. It is the smallest country within mainland AfricaHoare, Ben. (2002) ''The Kingfisher A-Z Encyclopedia'', Kingfisher Publicatio ...

, as well as parts of eastern Africa. This range includes the basins of the Corubal, Volta, Ouémé,

Niger ) , official_languages = , languages_type = National languagesBénoué Bénoué is a department of North Province in Cameroon. The department covers an area of 13,614 km and as of 2005 had a total population of 1,781,955. The capital of the department lies at Garoua. Subdivisions The department is divided a ...

, and

Nile The Nile, , Bohairic , lg, Kiira , Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest riv ...

Rivers, as well as those of

Lake Chad Lake Chad (french: Lac Tchad) is a historically large, shallow, endorheic lake in Central Africa, which has varied in size over the centuries. According to the ''Global Resource Information Database'' of the United Nations Environment Programme ...

and

Lake Turkana Lake Turkana (), formerly known as Lake Rudolf, is a lake in the Kenyan Rift Valley, in northern Kenya, with its far northern end crossing into Ethiopia. It is the world's largest permanent desert lake and the world's largest alkaline lake. B ...

. It has been successfully introduced to

Côte d'Ivoire Ivory Coast, also known as Côte d'Ivoire, officially the Republic of Côte d'Ivoire, is a country on the southern coast of West Africa. Its capital is Yamoussoukro, in the centre of the country, while its largest city and economic centre ...

, the Cross River in

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

, the Sanaga and

Nyong River The Nyong (formerly german: Yong) is a river in Cameroon. The river flows approximately to empty into the Gulf of Guinea. Course The Nyong originates east of the town of Abong-Mbang, where the northern rain forest feeds it. The river's lengt ...

s in

Cameroon Cameroon (; french: Cameroun, ff, Kamerun), officially the Republic of Cameroon (french: République du Cameroun, links=no), is a country in west-central Africa. It is bordered by Nigeria to the west and north; Chad to the northeast; the ...

, and the

Ogooué River The Ogooué (or Ogowe), also known as the Nazareth river, some long, is the principal river of Gabon in west central Africa and the fifth largest river in Africa by volume of discharge, trailing only the Congo, Kasai, Niger and Zambezi. Its wa ...

Gabon Gabon (; ; snq, Ngabu), officially the Gabonese Republic (french: République gabonaise), is a country on the west coast of Central Africa. Located on the equator, it is bordered by Equatorial Guinea to the northwest, Cameroon to the nort ...

, as well as the lower and middle

Congo River The Congo River ( kg, Nzâdi Kôngo, french: Fleuve Congo, pt, Rio Congo), formerly also known as the Zaire River, is the second longest river in Africa, shorter only than the Nile, as well as the second largest river in the world by discharg ...

basin, including Ubangui and Kasaï Rivers. It has also been introduced in

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Afric ...

. In some cases, introduction is reported to have had a negative impact on the local ecology.

Human use

African arowana is used locally as a food fish and has been collected in the past for the

aquarium trade Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. There is also a piscicultural fishkeeping industry, serving as a branch of agriculture. Origins of fishkeeping Fish ha ...

. It is not aggressive like its relatives. It is

aquacultured 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. lotus ...

in its native range, being a very successful culture due to its tolerance for crowding and ease of feeding.

References

External links

* {{Taxonbar, from1=Q387247, from2=Q14027417 Osteoglossidae Fish described in 1829 Taxa named by Georges Cuvier Fish of Lake Turkana Freshwater fish of West Africa