Information Last Reviewed Spring 2007
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Cichlidae
Juvenile Morphology
See adult morphology
Adult Morphology
Caudal fin with regular dark vertical stripes 
Dorsal fin with dark margin
Red coloration on head and lower part of the body in breeding males
Variable coloration in females dependent on subspecies- some may show coloration similar to males during breeding season
Distinguishing Characteristics
Nile tilapia is unlikely to be confused with native North American species but is similar to and has historically been confused with blue tilapia, Oreochromis aureus.
Caudal fin with regular dark vertical stripes vs. vague or variable stripes in O. aureus
Lacks the intense metallic blue on head of breeding males as in O. aureus
Typically higher number of dorsal spines (16-18 in O. niloticus and 15-16 in O. aureus)
Behavior
During the day fish may form large schools that break up during the night and reform at dawn 
Diet
Juveniles
Diurnal feeding pattern 
Omnivorous as fry consuming primarily copepods, hydracarines and insects
By 6 cm TL, diet becomes primarily phytoplankton
Adults
Diurnal feeding pattern
Primarily utilize phytoplankton (blue-green algae and diatoms) but may also consume macrophytes when phytoplankton densities are low
Growth
Maximum size of 64 mm TL
Typically obtain a total length of 25 cm by second year 
Maturity
Total length at first sexual maturity ranges from 9 to 15 cm TL 
Size at maturity positively correlated to maximum size observed in population
Age at maturity occurs in first year between 5 and 10 months of age
Female fecundity ranges from 149 to 2797 ova for fish between 36 and 975 g 
Spawning
In Israel spawning occurs between April and May
In Nile delta spawning more protracted- from April to August 
Reproduction first observed at 19 deg C
Males construct simple crater-shaped nests in sand or mud
Nests two times the male length or up to 1 m in diameter
Spawning habitat variable- from firm sand to muddy lagoons to steep lava shores
Females form school above the nests and swim in a circular motion
No lasting pair-bond retained during breeding season
Both male and female clean nest
Eggs are laid in approximately 20 batches over a 45-min to 2 hour period
Female picks up the eggs as soon as they are laid
Females develop a characteristic coloration pattern while brooding young (dark stripes across forehead and a dark operculum, chin, and eye) 
A single female may have several size classes of ova in the ovaries at any one time- indicating multiple spawns in a single season 
Eggs
Eggs yellow and pear-shaped
Female rolls eggs in her mouth during incubation 
A female may brood up to 2000 eggs at once
Hatching occurs at 4-5 days when young are 4.5 mm in length 
Juveniles
After hatching, young remain with mother and will reenter her mouth if threatened
Preferred Environment
Temperature
Eurythermal; can tolerate a wide range of temperatures (8 – 42 deg C)
Can tolerate temperatures of 8 deg C at night for several hours 
Prefers temperatures between 28 –30 deg C depending on acclimation temperature 
Oxygen
Can tolerate low dissolved oxygen (0.1ppm) 
Salinity
Moderately euryhaline; can withstand salinity range of 11 to 29‰ 
Reduced salinity tolerance when compared to many other introduced tilapia
Native Range
Tropical and subtropical Africa, Israel
North American Distribution
Established:
Georgia- Lake Seminole 
Florida- Lake Seminole
California 
Mississippi- Pascagoula River estuary Jackson Co. (Mark Peterson, Todd Slack final report)
Probable Means of Introduction
Escape from aquaculture facilities
Control of aquatic vegetation 
Negative
Largely unknown but likely similar to other tilapia species (see account for Oreochromis aureus)
Dispersal of exotic diseases and parasites
Positive
None identified
Control Measures
None identified
Beamish, F.W.H. 1970. Influence of temperature and salinity acclimation on temperature preferenda of the euryhaline fish T. nilotica. Journal of the Fisheries Research Board of Canada 27(7):1209-1214.
Duponchelle, F. and J. Panfili. 1998. Variation in age and size at maturity of female Nile tilapia, Oreochromis niloticus, populations from man-made lakes of Cote D’Ivoire. Environmental Biology of Fishes 52:453-165.
Duponchelle, F., P. Cecchi, D. Corbin, J. Nunez and M. Legendre. 2000. Variations in fecundity and egg size of female Nile tilapia, Oreochromis niloticus, from man-made lakes of Cote D’Ivoire. Environmental Biology of Fishes 57:155-170.
El-Zarka, S., A.H, Shaheen, and A.A. Aleem. 1970. Tilapia fishery in Lake Mariut: Age and growth of Tilapia nilotica in the lake. Bulletin of the Institute of Oceanography and Fisheries 1:149-182.
Fish, G.R. 1955. The food of Tilapia in East Africa. Uganda Journal 19(1):85-89.
Fishelson, L. 1967. Cichlidae of the genus Tilapia in Israel. Bamidgeh 18:67-80.
Fuller, P.L., L.G. Nico, and J.D. Williams. 1999. Nonindigenous Fishes Introduced into Inland Waters of the United States American Fisheries Society Special Publication Number 27.
Gwahaba, J.J. 1978. The biology of cichlid fishes (Teleostei) in an equatorial lake (Lake George, Uganda). Archives of Hydrobiology 83:538-551.
Hanon, L. 1975. Adaptations morphologiques et comportementales a l’incubation buccales chez les poisons cichlides: oeufs et alvins. Annales de la Societe Royale Zoologique de Belgique 105:169-192.
Kirk, R.G. 1972. A review of the recent developments in tilapia culture with special reference to fish farming in the heated effluents of power stations. Aquaculture 1:45-60.
Latif, A.F.A. and M.M. Rashid. 1972. Studies on Tilapia nilotica from Lake Nasser. I. Macroscopic characters of gonads. Bulletin of the Institute of Oceanography and Fisheries 215-238.
Magid, A. and M.M. Babiker. 1975. Oxygen consumption and respiratory behavior of three Nile fishes. Hydrobiologia 46:359-367.
Moyle, P.B. and L.H. Davis. 2000. A list of freshwater, anadromous and euryhaline fishes of California. California Fish and Game 86(4):244-258.
Philippart, J-Cl. And J-Cl. Ruwet. 1982. Ecology and distribution of tilipias, p. 15-59. In R.S.V. Pullin and R.H. Lowe-McConnell (eds.) The biology and culture of tilapias. ICLARM Conference Proceedings 7, 432 p. International Center for Living Aquatic Resources Management, Manila, Philippines.
Shireman, J.V. 1984. Control of aquatic weeds with exotic fishes. p. 302-312 in W.R. Courtenay, Jr., and J.R. Stauffer, Jr. Distribution, Biology and Management of Exotic Fishes. Johns Hopkins University Press. Baltimore.
Trewevas, E. 1983. Tilapiine Fishes of the Genera Sarotherodon, Oreochromis and Danakilia. British Museum of Natural History, Publ. Num. 878. Comstock Publishing Associates. Ithaca, New York. 583 pp.
Turner, G.F. and R.L. Robinson. 2000. Reproductive biology, mating systems and parental care, p. 33-58 in M.C.M. Beveridge and B.J. McAndrew (eds.) Tilapias: Biology and Exploitation. Kluwer Academic Press, Great Britain.
Yashouv, A. 1958. Biological data on Tilapia galilaea and Tilapia nilotica in fish ponds. Bamidgeh 10:46-52.
Axelrod, H.R. 1993. The most complete colored lexicon of cichlids. Tropical Fish Hobbyist Publications, Inc., Neptune City, NJ.
Axelrod, H.R., W.E. Burgess, N. Pronek, and J. G. Walls. 1985. Dr. Axelrod's atlas of freshwater aquarium fishes. Tropical Fish Hobbyist Publications, Inc., Neptune City, NJ.
Boschung, H.T. 1992. Catalogue of freshwater and marine fishes of Alabama. Alabama Museum of Natural History Bulletin 14:1-266.
Courtenay, W.R., Jr., and D.A. Hensley. 1979. Range expansion in southern Florida of the introduced spotted tilapia, with comments on environmental impress. Environmental Conservation 6(2):149-151.
Courtenay, W.R., Jr., D.A. Hensley, J.N. Taylor, and J.A. McCann. 1984. Distribution of exotic fishes in the continental United States. Pages 41-77 in W. R. Courtenay, Jr., and J. R. Stauffer, Jr., editors. Distribution, biology and management of exotic fishes. Johns Hopkins University Press, Baltimore, MD.
de Moor, I.J., and M.N. Bruton. 1988. Atlas of alien and translocated indigenous aquatic animals in southern Africa. South African National Scientific Programmes Report 144. Foundation for Research Development and Council for Scientific and Industrial Research, Pretoria, South Africa.
Eccles, D.H. 1992. FAO species identification sheets for fishery purposes: Field guide to the freshwater fishes of Tanzania. Food and Agriculture Organization of the United Nations (FAO), Rome, Italy. 145 pp.
Minckley, W.L. 1973. Fishes of Arizona. Arizona Fish and Game Department. Sims Printing Company, Inc., Phoenix, AZ.
Muoneke, M.I. 1988. Tilapia in Texas waters. Texas Parks and Wildlife Department, Inland Fisheries Data Series 9, Austin, TX. 44 pp.
Peterson, M.S., W.T. Slack and C.M. Woodley. 2002. Influence of tilapiine fishes on freshwater fishes in south Mississippi. Final Report to Mississippi Wildlife Fisheries and Parks. Report number 219
Fish Base:
USGS Nonindigenous Species Program:
http://nas.er.usgs.gov/queries/SpFactSheet.asp?speciesID=468