Max length : 127 cm male/unsexed; (Ref. 42492); common length : 62.0 cm TL male/unsexed; (Ref. 11248); max. published weight: 35.0 kg (Ref. 4537); max. reported age: 5 years (Ref. 11248)
Environment
Benthopelagic; freshwater; pH range: 6.5 - 8.2; dH range: ? - 30; depth range 0 - 80 m (Ref. 34291), usually 0 - 70 m (Ref. 34291)
Africa: Rivers Nile, Niger, Senegal, Volta and Lake Chad basins. East African rift lakes, except Lake Kivu, where it was introduced in 1959 and 1960, apparently without success. Countries | FAO areas | Ecosystems | Occurrences | Introductions
Short description
Dorsalspines
(total): 1;
Dorsalsoft rays
(total): 8 - 11;
Analspines: 0;
Analsoft rays: 11 - 14;
Vertebrae: 46 - 49. Body slightly elongated, 5-6 times longer than high (Ref. 7324). Head depressed (Ref. 43434), broad, about 1.3-1.6 times as long as wide (Ref. 30488), squarish when viewed from above (Ref. 28714), and without rough texture (Ref. 3034). Snout broadly rounded, projecting beyond the lower jaw (Ref. 2988). Premaxillary tooth plate 5-7 times longer than wide, a little shorter than and about as broad as the band of vomerine teeth (Ref. 2899). Eye with a free border (Ref. 51936, Ref. 36901). Four pairs of circum-oral barbels, showing great variation in length, being relatively longer in smaller individuals (Ref. 34290). Maxillary barbel 1.2-3.25 times head length (Ref. 3032, Ref. 43434), reaching ventral or not quite so far in adult and reaching anal fin or caudal peduncle in juveniles (Ref. 2899). Nasal barbel 0.2-0.4 times head length (Ref. 367). External mandibular barbel 0.5-1 times head length (Ref. 3032). Internal mandibular barbel 0.36-0.64 times head length; occipital processus not reaching the interneural (Ref. 51936). Dorsal fin short with a well developed spine (Ref. 34290), narrowly separated from the adipose fin (Ref.4967). First branched fin rays of dorsal fin hardly or not filamentous (Ref. 30488), longest ray 1/3-1/4 of the standard length. Last ray of dorsal fin in front of inner ray of ventral fin (Ref. 4912). Dorsal spine smooth (Ref. 36900). Long adipose dorsal fin present (Ref. 34290), 4-5 times as long as deep (Ref. 43434), 1.66-2 times as long as rayed dorsal (Ref. 2899). Anal fin short (Ref. 34290), 0.5-0.7 times head length (Ref. 367), inserted under the last branched dorsal fin ray or just behind this (Ref. 2756). Upper lobe of caudal fin often with a short filament (Ref. 7324). Some caudal fin rays may have filamentous extension (Ref. 34290). Caudal skeleton morphology described in Ref. 51975. Pectoral spine serrated along the inner side (Ref. 3032). No pectoral filaments (Ref. 3036, Ref. 367).
Coloration: dark grey-black above, creamy-white below (Ref. 34290). Body sometimes shot with gold and green (Ref. 4904). Some blackish may be present on the dorsal (Ref. 11235), anal and ventral fins (Ref. 2899). Blackish dots sometimes present on the posterior part of the back and on the adipose fin (Ref. 11235). Freshly caught fish have a greenish iridescence which soon fades to a dark greyish blue (Ref. 3023). Some juveniles may be completely blackish (Ref. 7324).
Inhabits lakes, swamps and rivers (Ref. 31256). Widespread in both shallow and deep water (Ref. 34291). Probably associated with rocky bottoms/coarse substrates (Ref. 27490). Mostly active during the night and the twilight hours (Ref. 2060). Juveniles may frequent exposed rocky shores (Ref. 12526). Feeds on insects, crustaceans, mollusks and fish. Some debris and vegetable matter may also be ingested (Ref. 28714). Moderately important as a food species in Lake Victoria, but becoming rare with the appearance of Nile perch (Ref. 4967). Catches decreased strongly in Lake Victoria after the Lates upsurge (Ref. 34291). Predation by Lates and competition with Lates (for haplochromines) may have played a role in the decline (Ref. 34291). A notably recovery in waters between 3m and 6m depth in Lake Victoria has been reported (Ref. 51900). Second most important food species in Lake Edward, Congo (Ref. 13302).
