Occupies an inshore zone and is common in lagoons (Ref. 87). Occasionally forms schools (Ref. 2, 39939). Is mainly diurnal (Ref. 2). Can tolerate considerable deoxygenation (Ref. 2, 1739, 4903, 13046, 32297) and warm temperatures (Ref. 2060), known to occur at 38.0 °C (Ref. 2). Feeds on phytoplankton (Ref. 2, 21, 4903, 34291, 55486) and detritus (Ref. 34291, 55486, 56058). Ovophilic (Ref. 2060), female mouthbrooder (Ref. 4903, 34291, 55074).

Africa: Lakes Edward, George and Albert and affluent rivers and streams of these lakes and of the Semliki River; tributaries of the Aswa River (possible introduction). Introduced from Lake Albert to Lake Victoria and fish ponds in catchment (Ref. 4967). Several countries report adverse ecological impact after introduction.

Native to: Lakes Albert, Edward and George. Introduced to: Lakes Kyoga, Victoria, Naivasha, and the Lower Ruzizi Basin and upper/middle parts of the Kagera river system (Welcomme 1967, 1988).

Eastern Africa: Lakes Edward and George and associated rivers and streams.

Dorsal spines (total): 15 - 18; Dorsal soft rays (total): 10 - 13; Anal spines: 3 - 4; Analsoft rays: 9 - 11; Vertebrae: 27 - 29

Maximum size: 232 mm SL

36.3 cm SL (male/unsexed; (Ref. 56123))

Diagnosis: lower jaw not longer than 34% of the head, preorbital depth not more than 23.2%; teeth of jaws and pharynx very small, those of the lower pharyngeal restricted to the posterior part of the pad; 27-29 vertebrae (Ref. 2). 28-30 scales on lateral line (Ref. 2, 34290, 54836), rarely 31 or 32 (Ref. 2). 19-24 gill-rakers on lower part of first gill-arch (Ref. 34290, 54836). Length/depth ratio of caudal peduncle 0.5-0.8 (Ref. 34290). Body dark olive-green (Ref. 2, 4903, 34290) to slately-black (Ref. 4903, 34290), clearly marked with whitish spots (Ref. 2, 4903, 34290, 54836). Lower lip often bluish-white; 8 to 11(12) dark vertical stripes sometimes visible on flanks (Ref. 2, 4903, 34290). Dorsal, anal and caudal fins dark; soft dorsal, entire caudal and anal fins with well-defined bluish-white spots (Ref. 4903, 34290). Genital papilla intensely white in both sexes (Ref. 2). Ground color in breeding males changes to dark blue-black, whilst whitish spots on body and fins are intensified; eye outstanding with its bright amber iris crossed by a black bar (Ref. 2, 4903, 34290).Description: body moderately deep in very young fish, becoming slender and lozenge shaped with increase in length (Ref. 55020). Maxillary ending below nostril (Ref. 55985) or a little behind it, between nostril and eye (Ref. 55074, 55985). Teeth very small, in 3-6 series, outermost bicuspid, inner tricuspid (Ref. 2, 55985). 2 series of scales on cheek (Ref. 2, 55985), rarely 1 or 2 scales of a third series (Ref. 2). Lower pharyngeal bone slender, its width usually less than, occasionally equal to, its median length (Ref. 2). Pharyngeal teeth very fine and crowded (Ref. 2), restricted to the posterior part of the pad in adults (Ref. 2, 55985). Flanges on either side of the apex of the triangular area of the lower pharyngeal bone unusually broad; microbranchiospines on outer surfaces of second, third and fourth arches; 7 scales over top of caudal peduncle above lateral line (Ref. 2). Generally 4, rarely 3, scales along the lateral series in the length of the caudal peducle (Ref. 56137). Genital papilla small, but white (Ref. 2, 56136) and conspicuous throughout life, crenellated in mature fishes of both sexes (Ref. 2). Dorsal fin reaching caudal fin base in juveniles and middle of caudal fin in adults; anal fin reaching as far backwards as dorsal fin; pectoral fins reaching anal fin base; pelvic fins reaching vent (Ref. 55074). 3-5 scales between bases of pectoral and pelvic fins; last anal fin spine about as long as last dorsal fin spine (Ref. 55985).Coloration: adults generally dark olive-green with white spots (Ref. 2, 4967, 56137) on the flanks formed by the paler centre of each scale (Ref. 2, 54836, 55074, 56136, 56137). If a pattern is present on the caudal fin, it consists of bluish white spots in a dark reticulum, but this may be restricted to the base or middle of the fin or masked by melanin; iridescence of opercular blotch and preorbital bone produces a dark violet effect (Ref. 2). Lower lip white (Ref. 56136). Dorsal fin usually without red marginal band (Ref. 2, 54836). Dorsal, soft anal and caudal fin spotted (Ref. 55985). Breeding males with a very dark blackish (Ref. 2, 55074, 56137) to blue-green body (Ref. 2, 56137) covered with intense white spots above the anal fin (Ref. 2), and a bright yellow iris that is crossed by an oblique dark bar in life (Ref. 2, 55074, 56136, 56137). Dorsal fin in breeding males may have some red color (but not opaque bright red as in other species) mixed with melanin, which disappears as the fish dies, leaving the lappets black (Ref. 2). Lower lip may be bluish green or greenish white in living male (Ref. 2, 56137), but becomes dark in preserved fish (Ref. 2). Branchiostegal membrane may have yellow patches in non-breeding fish and females, but is black in brooding females (Ref. 2, 56137). Juveniles: body usually dark blue (Ref. 55020) or greenish grey (Ref. 55020, 55074, 56136), with lighter ventral surface and scales showing up distinctly (Ref. 56137). 8-12 dark vertical bars on body (Ref. 2, 55074, 56137), extending from dorsal fin to belly (Ref. 56136). Bars may fade quickly in dead fish; one horizontal stripe is often prominent and appears to be caused by the localized intensification of the pigment of the vertical bars; iris usually with orange spot, intensifying with age (Ref. 55020). Indistinct Tilapia-mark (Ref. 2, 4903, 56136) marbling on a yellowish background (Ref. 2, 4903, 56137), taking the form of a dark bar reaching the depth of the dorsal fin and edged by a translucent area (Ref. 55020), but no longer distinguishable at 6.5-7.0cm SL (Ref. 2, 55020). Soft part of dorsal fin (Ref. 55020, 56136), and caudal and anal fins spotted with light circular spots which appear first at about 2.5cm and intensify with age (Ref. 55020).

benthopelagic; freshwater; pH range: 7.0 - 9.0; dH range: 10; depth range 0 - 10 m (Ref. 34291)

Habitat and Ecology

Systems

• Freshwater

Depth: 4 - 9m.
From 4 to 9 meters.

Habitat: demersal.

Inhabits shallow channels, lagoons and basins of vegetated lakes mentioned above. (See also Ref. 3736, 4967 and 32297). Essentially a species of lagoons, especially closed or nearly closed lagoons (Ref. 2) and shallow sheltered bays (Ref. 39939).

Oreochromis leucostictus (Tilapia leucosticta, T. nilotica) is prey of:
Homo sapiens
Actinopterygii
Aves

Based on studies in:
Uganda (Lake or pond)

This list may not be complete but is based on published studies.

Oreochromis leucostictus (Tilapia leucosticta, T. nilotica) preys on:
algae

Based on studies in:
Uganda (Lake or pond)

This list may not be complete but is based on published studies.

Contracaecum Disease (larvae). Parasitic infestations (protozoa, worms, etc.)

Cichlidogyrus Infestation. Parasitic infestations (protozoa, worms, etc.)

Cichlidogyrus Infestation 7. Parasitic infestations (protozoa, worms, etc.)

Cichlidogyrus Infestation 4. Parasitic infestations (protozoa, worms, etc.)

Cichlidogyrus Infestation 2. Parasitic infestations (protozoa, worms, etc.)

Cichlidogyrus Infestation 10. Parasitic infestations (protozoa, worms, etc.)

Cichlidogyrus Disease. Parasitic infestations (protozoa, worms, etc.)

Breeds over shallow muddy bottoms in sheltered inlets and in the papyrus fringe (Ref. 56123). Ripe males are found near the bottom over particular nesting areas (Ref. 39939). Males establish territory and make a nest by mouth-digging (Ref. 2), actively preventing invasion by other fishes (Ref. 39939). Nests made in shallow water, 15-300cm deep (Ref. 2, 56123), 16-20cm in diameter and 1-4m apart, dug in coarse leaf-debris or on shallow muddy bottoms (Ref. 2, 39939). Brooding females from the lagoons are found in pools adjacent to the lagoons/nursery swamps (Ref. 2, 39939). Fry spent their early days in shallow, grassy (Ref. 2, 32297, 39939) and deoxygenated swamps (Ref. 56123), but move to deeper water as their length increases (Ref. 32297, 39939).

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 23
Species With Barcodes: 1

Population

Population Trend

Least Concern (LC)

Major Threats

Conservation Actions

aquaculture: experimental; aquarium: commercial