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Desirable attributes of
Species used in small scale Alien species in African aquaculture |
Oreochromis andersonii (Three-spot tilapia)
Family: Cichlidae Size: Attains about 3.2 kg and 450mm TL. Native range: Central west Africa from 12 - 21 °S: Mainly the upper Zambezi, Kafue, upper Zaire, Cunene, Okavango and Lake Liambezi. Habitat preference & tolerance levels: Generalised habitat preferences. Found in well-vegetated, sheltered habitats along margins of mainstreams and in floodplain lagoons as well as in fairly fast-flowing sections of rivers, but not in very steep gradients. Adults in deep open water, juveniles inshore among vegetation. Temperature tolerance about 18 - 33 oC. Breeds at temperatures > 21oC. Hardy, tolerates fresh and brackish water. Survived in tanks with salinities up to 26 ppt. but not as tolerant of high salinites as some other cichlids. General biology and aquaculture potential: Omnivorous. Predominantly a bottom feeder. Takes algae from the mud surface, but also feeds on plankton, aquatic and terrestrial insect larvae, small crustacea and fine particulate matter (particularly diatoms and blue green algae). Opportunistic. Changes diet according to availability of food. Less specialised than O. macrochir which has a similar diet. Males excavate saucer-shaped nests, females mouthbrood eggs, larvae and fry and males guard the nest. Peak spawning in early summer, multiple broods throughout summer. After they leave the nest the juveniles continue to live in schools for a period. Will not spawn in natural environments if water too deep. Relatively low fecundity. Between 356-567 eggs in females of 170 - 260 mm. Feeding habits complementary to those of O. macrochir and T. rendalli so these species can be cultured together. Growth: In natural waters rarely matures when less than 3 years (at 27 cm TL). Marked differences in size of different sexes after maturation, males being larger. Lì: 313.5 - 608.4 k: 0.455- 0.176 to: between -1.029 and + 0.195 Regions farmed: (click to map) References: Bell-Cross & Minshull 1988; Trewavas 1983; Philippart & Ruwet 1982; Skelton 1993 |
