Oreochromis niloticus (Linnaeus, 1758)

Freshwater, Brackish

Sexual maturity is reached at 3-6 months depending on temperature, reaching about 30 g. Reproduction occurs only when temperatures are over 20°C. Several yearly spawnings every 30 days. Females incubate eggs inside their mouths (approximately for a week) where larvae hatch and remain until the vitellus is reabsorved.Egg size 1.5 mm, larval length at hatching 4 mm. Spawns in firm sand in water from 0.6 to 2 m deep of lakes. Males set up and defend territory which are visited by the females. Courtship lasts several hours. Eggs are shed in batches in shallow nest and fertilized by male. Each batch of eggs is picked up into oral cavity by female. Females solely involved in broodcare. Female carries up to 200 eggs in her mouth where the larvae hatch and remain until after the yolk-sac is absorbed.

Potamodromous. Migrating within streams, migratory in rivers, e.g. Saliminus, Moxostoma, Labeo. Migrations should be cyclical and predictable and cover more than 100 km.

Inhabit the littoral zone of lakes and are abundant in Lakes Turkana (Rudolf) and Albert. Although a freshwater species they are also found in brackish water like in the Nile Delta. The area occupied by the species extends from 8° S to 32° N and from 6000 ft (1830 m) to sea level. O. niloticus of Lake Edward form very large schools of 100 sq.m or more at the lake surface when feeding. The species takes epiphytic algae, diatoms or plankton according to conditions. (See also Ref. 3736).

Acanthogyrus Infestation. Parasitic infestations (protozoa, worms, etc.) ; Aeromonasis in Tilapia. Bacterial ; Aeromonosis. Bacterial ; Alitropus Infestation. Parasitic infestations (protozoa, worms, etc.) ; Amplicaecum Infection (Larvae). Parasitic infestations (protozoa, worms, etc.) ; Caligus Infestation 3. Parasitic infestations (protozoa, worms, etc.) ; Cichlidogyrus Disease. Parasitic infestations (protozoa, worms, etc.) ; Cichlidogyrus Infestation 10. Parasitic infestations (protozoa, worms, etc.) ; Cichlidogyrus Infestation 2. Parasitic infestations (protozoa, worms, etc.) ; Cichlidogyrus Infestation 3. Parasitic infestations (protozoa, worms, etc.) ; Cichlidogyrus Infestation 4. Parasitic infestations (protozoa, worms, etc.) ; Sporozoa-infection (Myxobolussp. ). Parasitic infestations (protozoa, worms, etc. )

Ponds (exotic species) and brackish water

Habitat benthopelagic; potamodromous ; freshwater; brackish; depth range 5 - ? m , usually ? - 20 m

IUCN Redlist Category: Not Evaluated

Not Evaluated IUCN 2006

fisheries: highly commercial; aquaculture: commercial