Xenomystus nigri (Günther, 1868)
African knifefish
Xenomystus nigri
photo by Kaladjian, M.

Family:  Notopteridae (Featherbacks or knifefishes), subfamily: Xenomystinae
Max. size:  30 cm SL (male/unsexed)
Environment:  demersal; freshwater; pH range: 6 - 8; dH range: 5 - 19
Distribution:  Africa: widely distributed in tropical Africa, in the Nile, Chad, Niger, Ogowe and Congo basins (Ref. 7431). Also present in coastal rivers in Sierra Leone, Liberia, Togo, Benin and Cameroon, but not found in Côte d'Ivoire nor Ghana (Ref. 7431).
Diagnosis:  Dorsal spines (total): 0-0; Anal spines: 0-0; Anal soft rays: 108-130. Body height 5-5.4 x SL, head length 6.9-7.5 x SL, snout smaller than eye, eye diameter 3.8-4.5 x head length, maxilla extends to vertical of eye center or just under the eye's posterior border, ventral spines 25-32
Biology:  Prefers quiet waters with vegetation. Females lay 150-200 eggs of 2 mm diameter (Ref. 1672). Can produce barking sounds. Comes to the surface from time to time to swallow air. Feeds at dusk and during the night on worms, crustaceans, insects and snails (Ref. 7020).
IUCN Red List Status: Least Concern (LC); Date assessed: 05 June 2019 Ref. (130435)
Threat to humans:  harmless

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