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Cichliformes (Cichlids, convict blennies) >
Cichlidae (Cichlids) > Pseudocrenilabrinae
Etymology: Oreochromis: Latin, aurum = gold + Greek, chromis = a fish, perhaps a perch (Ref. 45335); leucostictus: From the Greek "leukostiktos" = with white spots, referring to the white spotted color pattern of this species (Ref. 55074).
More on author: Trewavas.
Issue
Species also referred to as Tilapia nigra x T. zillii (Ref. 5166).
Environment: milieu / climate zone / depth range / distribution range
Ekologi
; sötvatten bentopelagisk; pH range: 7.0 - 9.0; dH range: 10 - ?; djupintervall 0 - 10 m (Ref. 34291). Tropical; 26°C - 28°C (Ref. 2060); 2°N - 2°S
Africa: Lakes Edward, George and Albert and affluent rivers and streams of these lakes and of the Semliki River (Ref. 5166). Also in tributaries of the Aswa River where it is not certain whether it occurs naturally or has been introduced (Ref. 5166, 34290). Introduced from Lake Albert to Lake Victoria and fish ponds in catchment (Ref. 1739, 4967); also introduced in Lake Kivu (Ref. 107916). Several countries report adverse ecological impact after introduction.
Length at first maturity / Size / Vikt / Age
Maturity: Lm 19.5, range 6 - 22 cm
Max length : 36.3 cm SL hane/ej könsbestämd; (Ref. 56123)
Short description
Bestämningsnycklar | Morfologi | Morfometri
Taggstrålar i ryggfenan (totalt) : 15 - 18; Mjukstrålar i ryggfenan (totalt) : 10 - 13; Taggstrålar i analfenan: 3 - 4; Mjukstrålar i analfenan: 9 - 11; Ryggkotor: 27 - 29. Diagnosis: A small medium-sized tilapia, with a relatively deep, flattened body and small head and jaws (Ref. 118638). 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). Scales on lateral line 28-30 (Ref. 2, 34290, 54836), rarely 31 or 32 (Ref. 2). Gill-rakers on lower part of first gill-arch 19-24 (Ref. 34290, 54836). Length/depth ratio of caudal peduncle 0.5-0.8 (Ref. 34290). Males are black with white spots on the flanks and fins; females are more olive coloured, with pale ventral regions, faint vertical barring and dark anal and tail fins (Ref. 2, 4903, 34290, 118638). Lower lip often bluish-white; 8 to 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).
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), a maternal mouthbrooder (Ref. 4903, 34291, 55074, 118638). Males dig simple pits in shallow water (Ref. 118638). Strongly prone to precocious maturity; this makes it an undesirable aquaculture species (Ref. 118638). Caught in large numbers by small-meshed nets in shallow swampy areas, where it has become established (Ref. 118638). When stocked along with Nile tilapia, probably will assist in filling all suitable niches and competitively excluding native species (Ref. 118638).
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).
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. 130435)
Threat to humans
Potential pest (Ref. 13364)
Human uses
Fiskeri: ; Vattenbruk: experimentell; Akvarium: Kommersiell
Verktyg
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Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01380 (0.00751 - 0.02539), b=2.98 (2.83 - 3.13), in cm total length, based on LWR estimates for this species & Genus-body shape (Ref.
93245).
Trofisk nivå (Ref.
69278): 2.3 ±0.14 se; based on food items.
Generation time: 1.8 ( na - na) years. Estimated as median ln(3)/K based on 1
growth studies.
Resiliens (Ref.
120179): Mellan, lägsta populationsfördubblingstid 1,4-4,4 år (K=0.63; assumed tmax>2).
Fishing Vulnerability (Ref.
59153): Low vulnerability (25 of 100).
