Heterobranchus
| Heterobranchus | ||||||||||||
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Heterobranchus longifilis |
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| Scientific name | ||||||||||||
| Heterobranchus | ||||||||||||
| Geoffroy Saint-Hilaire , 1809 |
Heterobranchus is aspecies of fish from the family of the gill sac catfish (Clariidae)foundin Africa . Heterobranchus species occur in tropical Africa south of the Sahara and in the Nile .
features
They have a streamlined, torpedo-shaped body, a dorso- ventrally flattened head and reach lengths of 64 cm to 1.5 meters. The dorsal and anal fins are long, the pectoral fins have a powerful spine. The pelvic fins have a narrow fin base. In contrast to the externally similar gill sac catfish genus Clarias , the Heterobranchus species have a well-developed, long adipose fin . Four pairs of barbels are arranged around the mouth . The premaxillary and vomer are covered with teeth arranged in a band. The species are gray-brown or gray to green-gray in color, with a lighter to yellow underside, some individuals of all species are spotted dark.
Like some related genera, Heterobranchus species with a structure called the suprabranchial organ, formed from the second and fourth gill arches, can breathe atmospheric air. The animals can cover distances of a few hundred meters over land, using the pectoral fins as locomotion organs.
species
Fishbase lists four species.
- Heterobranchus bidorsalis Geoffroy Saint-Hilaire, 1809 ( type species of the genus). Body length up to 80 centimeters. In theupper reaches of the Nile , Niger system including Benue , Volta , Senegal and Gambia . The species is kept and bred in fish ponds.
- Heterobranchus boulengeri Pellegrin, 1922 . Body length up to 64 centimeters. Rarely found, more often only in the Mwerusee , alsoprovenin the lower reaches of its tributary Luapula .
- Heterobranchus isopterus Bleeker, 1863 . Body length up to 51 centimeters. Waters on the West African coast from Konkouré in Guinea to Ohumbe in Cameroon , at one point in Upper Senegal.
- Heterobranchus longifilis Valenciennes, 1840 . Body length up to 117 centimeters, maximum weight up to 50 kilograms. In the Nile, Benue, Shari , Niger, Volta, Gambia and other waters near the West African coast from Guinea to the Sanaga , in the entire Congo system, Lake Eduard , Lake Tanganyika , Zambezi including Kariba Dam , Lake Malawi and its outflows Shire , Pungwe and Búzi . In other areas of Africa, such as the Ivory Coast , introduced and bred in fish farms.
Systematics
In a phylogenomic analysis (based on the sequence of the cytochrome b gene) the genus was found to be monophyletic , as suggested by the morphological analysis by Teugels and Denayer. The related genus Clarias proved to be paraphyletic to her (and the genus Channallabes ) . Heterobranchus bidorsalis can be crossed with some Clarias species such as Clarias anguillaris and Clarias gariepinus , the hybrids are fertile. Some of the hybrids are used in commercial fish farms.
literature
- Hans-Jochim Franke: Handbook of Welskunde. Urania-Verlag, 1985.
- Günther Sterba : The world's freshwater fish. 2nd Edition. Urania, Leipzig / Jena / Berlin 1990, ISBN 3-332-00109-4 .
- CG Teugels & B. Denayer: (1991) A systematic revision of the African catfish genus Heterobranchus . Zoological Journal of the Linnean Society 98: 237-257.
Individual evidence
- ^ Jean François Agnese, Guy G. Teugels JD McEachran (2001): Genetic Evidence for Monophyly of the Genus Heterobranchus and Paraphyly of the Genus Clarias (Siluriformes, Clariidae). Copeia Vol. 2001, No. 2: 548-552.
Web links
- Heterobranchus on Fishbase.org (English)