Actinopterygii (ray-finned fishes) > Perciformes
(Perch-likes) > Cichlidae
(Cichlids) > Pseudocrenilabrinae
Etymology: Oreochromis: Latin, aurum = gold + Greek, chromis = a fish, perhaps a perch (Ref. 45335); andersonii: Named for the Swede Charles John Anderson, who explored Namibia during the middle of the 19th century (Ref. 13337).
Environment: milieu / climate zone / depth range / distribution range
Freshwater; brackish; benthopelagic; depth range 0 - 10 m (Ref. 54002), usually 3 - 6 m (Ref. 54002). Tropical; 18°C - 33°C (Ref. 3); 12°S - 21°S
Africa: Ngami basin, Okavango River; Cunene River and Mossamedes, Angola; upper Zambezi, Kafue River; middle Zambezi, Lake Kariba and Cabora Bassa since construction of dams. Several countries report adverse ecological impact after introduction (2265). Reported as introduced in Kasanka National Park (upper Congo River basin) in Zambia (Ref. 95585).
Length at first maturity / Size / Weight / Age
Maturity: Lm 24.4, range 12 - 15 cm
Max length : 61.0 cm TL male/unsexed; (Ref. 40637); max. published weight: 4.7 kg (Ref. 40637); max. reported age: 13 years (Ref. 13400)
(total): 15 - 18;
soft rays: 9 - 13;
Vertebrae: 30 - 32. Diagnosis: male genital papilla bluntly conical with a narrow flange slightly notched in the middle; jaws enlarged in breeding males, which in this species are normally not less than 30cm TL; scales in lateral line series 31-35, usually 32-33; scales of cheek in 3 full rows; vertebrae 30-32; total number of dorsal rays 28-31. Pectoral fin in adults 34-43% SL (Ref. 2), very long (Ref. 1904). Depth of body 40.5-50.5% SL; color-pattern of non-breeding fish and female always including 3 or 4 conspicuous mid-lateral blotches and a red margin on dorsal and caudal fins; breeding male with red margins broader and brighter and general dark, iridescent purplish-brown color of head, back and flanks, masking the blotches; no series of vertical spots or vertical stripes on caudal fin; nest a simple circular depression (Ref. 2).
Occurs in both river and swamp habitats and is adapted to fairly fast-flowing rivers (Ref. 6465). Hardy, tolerating fresh and brackish water (up to 20ppt, Ref. 3), preferring slow-flowing or standing water; adults occupy deep open waters, juveniles remain inshore among vegetation (Ref. 7248, 52193). Prefers fairly deep, quiet water with some weed cover; hippo pools are a favoured retreat (Ref. 12524, 13337). Forms schools (Ref. 2, 12524, 13337). Mainly diurnal; a detritivore which feeds on fine particulate matter (Ref. 2), including algae (Ref. 246, 12524, 13337, 53992), diatoms, detritus (Ref. 7248, 52193, 53992) and zooplankton (Ref. 7248, 52193). Larger individuals also take insects and other invertebrates (Ref. 53992). Feeding regime is variable, the diet changes according to food availability (Ref. 6465). Female mouthbrooder (Ref. 87, 246, 6465, 12524, 13337). Fine angling and table species (Ref. 6465, 12524, 13337).
Spawning did not occur in ponds at a temperature below 21°C (Ref. 2). Rarely more than one brood in a season (Ref. 87, 246), but known to breed at least twice a year under pond conditions (Ref. 12524, 13337). Males excavate saucer-shaped nests (Ref. 246, 314, 6465, 12524, 13337, 54048) that can be up to 75cm in diameter and 30cm deep, using mouth and fins (Ref. 2, 314, 52307), in the center of their territory (Ref. 52307), on a sandy substrate (any vegetation is uprooted with its mouth) and in water from 1-3m deep, where they display to attract females (Ref. 12524, 13337, 54048). Up to 40 nests can be found together (Ref. 6465). Females are the primary care-givers (Ref. 52307), moutbrooding eggs, larvae and fry; multiple broods are raised during the warmer months (Ref. 7248, 52193). She lays her eggs in the concavity on top of the nest, the male fertilizes the eggs whereupon the female takes the eggs into her mouth where they are incubated; males guard the nest and females against all intruders; parental care is exercised for the first few weeks after the eggs hatch (Ref. 12524, 13337).
Trewavas, E., 1983. Tilapiine fishes of the genera Sarotherodon, Oreochromis and Danakilia. British Mus. Nat. Hist., London, UK. 583 p. (Ref. 2)
IUCN Red List Status (Ref. 119314)
CITES (Ref. 115941)
Threat to humans
Potential pest (Ref. 6465)
Fisheries: commercial; aquaculture: commercial; gamefish: yes
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01622 (0.01256 - 0.02095), b=2.99 (2.95 - 3.03), in cm Total Length, based on LWR estimates for this species (Ref. 93245
Trophic Level (Ref. 69278
): 2.1 ±0.0 se; Based on diet studies.
Resilience (Ref. 69278
): Medium, minimum population doubling time 1.4 - 4.4 years (K=0.17-0.22; tm=4; tmax=13).
Vulnerability (Ref. 59153
): Moderate vulnerability (40 of 100) .