''Oreochromis esculentus'', the Singida tilapia or Graham's tilapia, is a species of

cichlid Cichlids are fish from the family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses ( Labridae), in the order Perciformes, but molecular studies have contradicted this ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Lake Victoria Lake Victoria is one of the African Great Lakes. With a surface area of approximately , Lake Victoria is Africa's largest lake by area, the world's largest tropical lake, and the world's second-largest fresh water lake by surface area after ...

basin, including some of its satellite lakes such as Kyoga, in

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...

Uganda }), is a landlocked country in East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territor ...

, and

Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

. Its common name refers to Lake Singida, but this population is the result of an

introduction Introduction, The Introduction, Intro, or The Intro may refer to: General use * Introduction (music), an opening section of a piece of music * Introduction (writing), a beginning section to a book, article or essay which states its purpose and g ...

that happened in the 1950s. This fish is highly valued by local fishermen, who know it as ''ngege''. In 1927-1928 Michael Graham conducted the first ever systematic

Fisheries Survey of Lake Victoria Lake Victoria supports Africa's largest inland fishery, with the majority of present catch being the invasive Nile perch, introduced to the Lake in the 1950s. Prior to the introduction of Nile perch as well as Nile tilapia, the fish community w ...

. In his official report of the expedition, Graham wrote that "The ngege or satu ''Tilapia esculenta'', is the most important food fish of the lake, whether for native or non-native consumption. No other fish equals it in the quality of the flesh. It is convenient size for trade, travels well and is found in much greater numbers than other important fish, such as semutundu (Luganda), ''Bagrus sp.'.Graham M. (1929.) The Victoria Nyanza and Its Fisheries: A Report on the Fish Survey of Lake Victoria 1927–1928 and Appendices. London: Crown Agents for the Colonies. 256pp. Furthermore, Graham noted that "The introduction of the European flax gill-net of 5 inch mesh has undoubtedly caused a diminution in the number of ngege in those parts of the Kavirondo Gulf, the northern shore of the lake, the Sesse Islands and Smith's Sound which are conveniently situated to markets". ''Oreochromis esculentus'' has been introduced into the

Pangani River The Pangani River (pin-gi'nee) (also called Luffu and Jipe Ruvu, especially in older sources, and probably once called Rhaptus) is a major river of northeastern Tanzania. It has two main sources: the Jipe Ruvu River, Ruvu, which rises as River L ...

basin, where it presents a threat to the native relative '' O. jipe''.

Description

This species reaches a

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

of up to , although it only rarely surpasses .

Conservation

Due to the introduced

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

Nile perch The Nile perch (''Lates niloticus''), also known as the African snook, Goliath perch, African barramundi , Goliath barramundi, Giant lates or the Victoria perch, is a species of freshwater fish in family Latidae of order Perciformes. It is wid ...

(''Lates niloticus'') and the highly competitive

Nile tilapia The Nile tilapia (''Oreochromis niloticus'') is a species of tilapia, a cichlid fish native to the northern half of Africa and the Levante area, including Israel, and Lebanon. Numerous introduced populations exist outside its natural range. It i ...

(''Oreochromis niloticus''), with the main population in Lake Victoria itself having declined by more than 80% in the last 20 years. In addition to the threat from the introduced species, the remaining populations are also under heavy fishing pressure, leading to the evaluation of this species as near threatened.

References

External links

* esculentus Fish of Lake Victoria Critically endangered fish Critically endangered fauna of Africa Fish described in 1928 Taxonomy articles created by Polbot {{Tilapiini-stub