Azeroual, A., Entsua-Mensah, M., Getahun, A., Lalèyè, P., Moelants, T. & Vreven, E.
Snoeks, J., Tweddle, D., Getahun, A., Lalèyè, P., Paugy, D., Zaiss, R., Fishar, M.R.A & Brooks, E.
This species has a wide distribution, with no known major widespread threats. It is therefore listed as Least Concern. It has also been assessed regionally as Least Concern for western Africa. In eastern Africa, it is categorized as Vulnerable. Due to a lack of information on the species distribution and threats in north and northeast Africa, it has been categorized as Data Deficient. It could even be Regionally Extinct within north Africa.
Gymnarchus niloticus naturally occurs from Senegal to Ethiopia.
Central Africa: According to Thys van den Audenaerde (1966) the species has been introduced from Fort-Lamy, Chad to Yaoundé, Cameroon. Its presence is not confirmed by museum records. It is unknown whether the species is established or not.
Eastern Africa: It is present in the northern part of the Lake Turkana basin (Seegers et al. 2003).
Northern Africa: It is present but rare in Lake Nasser (also known as Lake Nubia)
Northeast Africa: This species is found in the Ghazal and Jebel systems, White Nile, and Nile to Lake Nasser, Sudan. It also occurs in the Baro River, Ethiopia.
Western Africa:Gymnarchus niloticus occurs in the basins of the rivers Gambia, Senegal, Niger, Volta, Ouémé and Chad.
Gymnarchus niloticus is a demersal, potamodromous species. Following flooding of the river banks (Gambia river) this species builds large elliptical floating nests in densely vegetated swamps at depths of about 1-1.5 m. Here the eggs are laid and later guarded by one of the parents. Distinct pairing. It lays about 1000 'amber-like' eggs and the larvae hatch after 5 days (Budgett 1901). It feeds on crustaceans, insects, snails, frogs and fish (Bailey 1994). During the day it hides in holes or close to the roots of water plants. This species possesses an electric organ that extends along almost the entire trunk to the tip of the tail (Bennet 1971), and is also equipped with ampullary receptors and two types of tuberous receptors for electroreception (Szabo 1974). It showed increased electric organ discharge (EOD) rate by 50-60 Hz between 21 and 31°C (Lissmann 1958). Gymnarchus niloticus breeds in well-vegetated, marginal areas of swamps and rivers, where a large, floating nest, about 1 m in diameter is constructed.
This is a commercially important species in central Africa. In northern Africa, dams, water pollution (agriculture, domestic and commercial/industrial), groundwater extraction and drought pose possible threats. Deforestation and drought are local threats in western Africa.
Pan-Africa freshwater assessment references. Currently, full citations for references used in the Pan-Africa biodiversity assessments are unavailable on the Red List web site. These will be added to the site in 2011. We apologise for any inconvenience this causes.
IUCN. 2010. IUCN Red List of Threatened Species (ver. 2010.3). Available at: http://www.iucnredlist.org. (Accessed: 2 September 2010).
Azeroual, A., Entsua-Mensah, M., Getahun, A., Lalèyè, P., Moelants, T. & Vreven, E. 2010. Gymnarchus niloticus. The IUCN Red List of Threatened Species 2010: e.T181688A7706153. . Downloaded on 30 November 2015.
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