Common names:
Victoria tilapia
Lunyoro: Wasamaru Lunyara: Binage Ludope: Mnege Lukenyi: Nsalia General: Ngege (Lake Victoria basin)

Taxonomic tree
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii (ray-finned fish)
Order: Cichliformes (Cichlids)
Family: Cichlidae (Cichlids)
Genus: Oreochromis
Species: Oreochromis variabilis (Boulenger, 1906)
Number of Occurrancies: 128

Etymology(based on Scharpf & Lazara, 2019)

• Oreochromis: oreos, mountains, referring to Mt. Kilimanjaro (Tanzania), location of O. hunteri, type species; chromis, possibly derived from chroemo (to neigh), referring to a drum (Sciaenidae) and its ability to make noise, later expanded to embrace cichlids, damselfishes, dottybacks and wrasses (all perch-like fishes once thought to be related), often used in the names of African cichlid genera following Chromis (now Oreochromis) mossambicus Peters 1852.


• variabilis: referring to “very variable” coloration, “some specimens olive-brown, others brilliant vermilion on the sides, others bright yellow with black markings and the dorsal and caudal fins edged with red.”

Synonyms:click here to view synonyms

Type locality: Lake Victoria, near Entebbe, Uganda. Lectotype at British Museum of Natural History (BMNH)

General identification features for tilapiine cichlids

• A single nostril on each side of the head; dorsal fin with contineous spinous and soft-rayed parts; lateral line interrupted(with anterior superior part and posterior inferior part)


• Cycloid scales


• Tilapia mark (dark spot at the posterior end of the dorsal fin) in juveniles

Distinguishing characters for the genus

• More gillrakers (usually 18-28) on the first gill arch


• Outermost teeth bicuspid in young and in adult females, but in mature males of several species becoming unicuspid by wear or replacement: Note that O. niloticus is an exception; some or all teeth of outermost row are replaced by tricuspids


• Genital papilla of male and female well developed


• Maternal mouth-brooders, usually with marked sexual dimorphism and discromatism (sexual differences related to size and color respectively) at breeding time; males have distinctive and conspicuous breeding colors and are often bigger than females


• Jaws that are greatly enlarged as fish matures, especially males


• Scales of belly smaller, in some species much smaller, than those of flanks; transition between the two sizes gradual or abrupt


• Pharyngeal teeth ranging from relatively coarse, with the length of the lower dentigerous area approximately equal to that of the blade or a little longer, to very fine on a reduced dentigerous area.

Distinguishing characte for the species

• Relatively deep bodied species with a characteristic convexity (or bumb) in front of, and partly above the eye (Diagnostic).


• A characteristic feature of breeding males is the conspicuous genital tassel (a branched structure, yellow to orange in color, developed from genital papilla, which lies immediately before the anus


• Breeding males bluish-grey to bluish green, intense bright red/orange margins to the dorsal and caudal fins; non-breeding fishes uniformly grey or greyish-green, fins grey (the caudal only, if at all, spotted), and dorsal fin tipped with orange throughout life (similar characteristics for breeding females); immature fishes are greyish-silver, with 8-10 dark vertical stripes on the flanks and caudal peduncle, a dorsal fin outlined in orange and a relatively indistinct black marbling "Tilapia" mark.


• Length to depth ratio of the caudal peduncal 0.8-0.9 (Diagnostic)

Additional remarks: This species is critically endangered. Between 1930s and 1960s, the species declined strongly due to intensive fishing. Later, competetion and hybridization with introduced tilapias, especially O. niloticus  suppressed their recovery (Ogutu-Ohwayo 1990). Remnant populations are still hanging in the Upper Victoria Nile, but are also under immense pressure from hydro-electric power dams.

Distribution in Uganda: Lake Victoria and its affluent rivers, Lakes Nabugabo, Kyoga, Kwania and Salisbury and the Victoria Nile

Occurence: Native

Habitat: Benthopelagic; in lakes, it is commmon in waters less than 20 m deep and partly on exposed shores. 

Feeding: Mainly phytoplankton derived from bottom deposits; algae are also scraped from rocks and aquatic plants   

Biology: Female mouth-brooder; spawning occurs on firm/sandy bottoms in shallow waters often on exposed shores, with the males congregating in arenas, but the breeding season is not well defined. Size at 50% maturity ranges from 16-19 cm TL (being higher in males than females), fecundity ranges from 73-14800 eggs in fishes of 13.5-18.6 cm TL, and growth is allometric in both males and females (Njiru et al., 2012). The fish can attain up to 11 cm in the first year, which doubled by the fourth year. Maximum size is about 30 cm SL (Witte and van Densen, 1995).

Economic importance/End use: The species is rare. 

IUCN conservation status: click here to view IUCN status

Threats: Hybridization with introduced tilapias

Main references

• Greenwood PH. 1966. The fishes of Uganda. The Uganda Society, Kampala. 131 pages.


• Twewavas E. 1983. Tilapiine fishes of the genera Sarotherodon, Oreochromis and Danakilia. British Museum (Natural History), London. 604 pages


• Sharpf C, Lazara J.K. 2019. Fish Name Etymology Database v5. www.etyfish.org


• Witte F & van Densen W.L.T. 1995. Fish Stocks and Fisheries of Lake Victoria: a handbook for field observations. Samara Publishing Limited, Netherlands


• Njiru M, Okeyo-Owuor J.B, Gichuki J, 2012. Some aspects of the biology and life-history strategies of Oreochromis variabilis (Boulenger 1906) in the Lake Victoria Basin. Lakes & Reservoirs: Research and Management, 17: 65–72