The
African arowana,
Heterotis niloticus, is one of seven members of the arowana family. Despite being called an "Arowana", the African arowana is more closely related to
Arapaima gigas, the only other member in the subfamily
Heterotidinae. The only plankton-feeding
osteoglossid, the African arowana has a more terminal mouth than other species of arowana (
Osteoglossum and
Scleropages). Rarely imported for the home aquarium, in captivity it is known to be willing to accept dry, floating pellets on a regular basis and, in fact, sometimes does not consume live goldfish.
[edit] Description
Like the other Osteoglossids, 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 times
Standard Length (SL). It has been reported to reach up
to 100 cm (39 in) SL and weigh up to 10.2 kg (22 lb).
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, 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.
[edit] Range
This species is widespread throughout
Africa, where it is native to all the watersheds in Sahelo-Sudanese region,
Senegal, and
Gambia as well as parts of eastern Africa. This range includes the basins of the
Corubal,
Volta,
Ouémé,
Niger,
Bénoué, and
Nile Rivers as well as those of
Lake Chad and
Lake Turkana. It has been successfully introduced to
Côte d'Ivoire, the
Cross River in
Nigeria, the
Sanaga and
Nyong rivers in
Cameroon, and
Ogooué River in
Gabon, as well as the lower and middle
Congo River basin, including
Ubangui and
Kasaï Rivers. It has also been introduced in
Madagascar. In some cases, introduction is reported to have had a negative impact on the local ecology