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The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: Nile Tilapia

Synonyms and Other Names: Nile mouthbrooder

Taxonomy: available through www.itis.gov

Identification: A commonly used name is Tilapia nilotica. Distinguishing characteristics, synonyms, an illustration, keys, and a discussion of hybrids in Trewavas (1983). Distinguishing characteristics and illustration were also given by Eccles (1992). Photographs appeared in Axelrod et al. (1985) and Axelrod (1993). This species closely resembles Oreochromis aureus. Before the two species were shown to be distinct, many or most accounts of "Tilapia nilotica" in U.S. ponds probably referred to O. aureus, likely imported from Israel (Trewavas 1983).

In the U.S. and other regions where they have been introduced, tilapias have hybridized and introgressed in aquaculture settings and subsequently escaped into the wild. Reproductively viable hybrids have resulted from these various crosses and thus, for most tilapia populations in the U.S., the use of meristics and traditional systematics to assign species names to specimens is not useful (see: Costa-Pierce 2003).

Nile Tilapia is closely related to, and often confused with, Blue Tilapia (O. aureus). These two species can generally be distinguished by the following characteristics (Trewavas 1983):

	Blue Tilapia	Nile Tilapia
Number of dorsal spines	15-16 (mode 16)	16-18 (mode 17)
Total dorsal fin rays	27-30 (mode 28)	29-31 (mode 30)
Banding on caudal fin	No distinct bands/stripes	Distinct, regular dark stripes
Male breeding coloration	Metallic blue	Red
Dorsal fin margin	Vermillion	Dark grey or black

 

Size: 63 cm (de Moor and Bruton 1988)

Native Range: Tropical and subtropical Africa, Middle East. Widely distributed in Nile and Niger river basins and in lakes Tanganyika, Albert, Edward, and George, as well as in many smaller drainages and lakes in western and eastern Africa; also in Middle East in Yarkon River, Israel (Trewavas 1983).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology: Nile Tilapia is primarily herbivorous, with aquatic macrophytes, algae, and diatoms generally comprising >90% of its diet and the remainder including aquatic insects and crustaceans and fish eggs (Khallaf and Alne-na-ei 1987).

Means of Introduction: This species was introduced for aquaculture purposes. It was introduced into open waters, likely through escape or release from fish farms.

Status: Established in Mississippi. Possibly established in a large reservoir bordering Florida and Georgia. Established locally (Alachua County) in Florida. Reported from Alabama and Arizona.

Impact of Introduction:

Summary of species impacts derived from literature review. Click on an icon to find out more...

Ecological	Economic

Nile Tilapia exert competition pressures on native fish and are known to prey on amphibians and juveniles of other fish species (Zambrano et al. 2006). However, Peterson et al. (2006) found little overlap in the diets of Nile Tilapia and three native centrarchids (Bluegill Lepomis macrochirus, Redear Sunfish L. microlophus, and Largemouth Bass Micropterus salmoides), with tilapia foraging at a lower trophic level (e.g., higher proportion of small benthic invertebrates and detritus) than native centrarchids (primarily consuming fishes and larger invertebrates). In Nevada and Arizona, the introduction of O. niloticus has resulted in the decline of endangered Moapa Dace and Moapa White River Springfish (Wise et al. 2007). Martin et al. (2010) found that Nile Tilapia displaced native Redspotted Sunfish (L. miniatus) from preferred habitat in laboratory experiments, exposing the sunfish to greater predation pressure.

Remarks: A specimen taken from Lake Seminole on the Georgia side of the lake near Saunder's Slough in 1991 was originally reported as O. aureus (Gennings, personal communication); however, all available specimens and photographs of tilapia from that lake have thus far proven to be O. niloticus (Smith-Vaniz, personal communication). Although O. niloticus has been reported from Texas, these reports were based on erroneous identifications of other tilapia species (Hubbs 1982, cited by Muoneke 1988). Reports of this species in Arizona also may be based on a misidentification. Minckley's (1973) figure 122, labeled as "Tilapia nilotica," and his description of their young, more closely match T. mariae (Courtenay and Hensley 1979; Courtenay et al. 1984, 1986).

Grammer et al. (2012) found that introduced Nile Tilapia in Mississippi live to ~4 years, confirming multi-year survival and establishment of this population.

Nile Tilapia have also been introduced into Thailand (Tongnunui and Beamish 2009) and El Salvador (McMahan et al. 2013).

Voucher specimens: Florida (UF many specimens), Georgia (UF, UGAMNH), Mississippi (MMNH).

References: (click for full references)

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.

Costa-Pierce, B.A. 2003. Rapid evolution of an established feral tilapia (Oreochromis spp.): the need to incorporate invasion science into regulatory structures. Biological Invasions 5: 71-84.

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., and J.D. Williams. 1992. Dispersal of exotic species from aquaculture sources, with emphasis on freshwater fishes. 49-81 in A. Rosenfield, and R. Mann, eds. Dispersal of living organisms into aquatic ecosystems. Maryland Sea Grant Publication, College Park, MD.

Courtenay, W.R., Jr., D.A. Hensley, J.N. Taylor, and J.A. McCann. 1984. Distribution of exotic fishes in the continental United States. 41-77 in W.R. Courtenay, Jr., and J.R. Stauffer, Jr., eds. Distribution, biology and management of exotic fishes. Johns Hopkins University Press, Baltimore, MD.

Courtenay, W.R., Jr., D.A. Hensley, J.N. Taylor, and J.A. McCann. 1986. Distribution of exotic fishes in North America. 675-698 in C.H. Hocutt, and E.O. Wiley, eds. The zoogeography of North American freshwater fishes. John Wiley and Sons, New York, NY.

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.

Gennings, R.M. - Georgia Department of Natural Resources, Atlanta, GA. Response to NBS-G nonindigenous questionnaire.

Grammer, G.L., W.T. Slack, M.S. Peterson, and M.A. Dugo. 2012. Nile tilapia Oreochromis niloticus (Linnaeus, 1758) establishment in temperate Mississippi, USA: multi-year survival confirmed by otolith ages. Aquatic Invasions 7: in press.

Hornsby, J. - Alabama Game & Fish, Montgomery, AL.

Khallaf, E.A., and A.A. Alne-na-ei. 1987. Feeding ecology of Oreochromis niloticus (Linnaeus) & Tilapia zillii (Gervais) in a Nile Canal. Hydrobiologia 146:57-62.

Martin, C.W., M.M. Valentine, and J.F. Valentine. 2010. Competitive interactions between invasive Nile tilapia and native fish: the potential for altered trophic exchange and modification of food webs. PLoS ONE 5(12): e14395.

Minckley, W.L. 1973. Fishes of Arizona. Arizona Fish and Game Department. Sims Printing Company, Inc., Phoenix, AZ.

McMahan, C.D., W.A. Matamoros, F.S. Álvarez Calderón, W.Y. Henríquez, H.M. Recinos, P. Chakrabarty, E. Barraza, and N. Herrera. 2013. Checklist of the inland fishes of El Salvador. Zootaxa 3608(3):440-456. http://dx.doi.org/10.11646/zootaxa.3608.6.2

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, N.J. Brown-Peterson, and J.L. McDonald. 2004. Reproduction in nonnative environments: establishment of Nile tilapia Oreochromis niloticus, in coastal Mississippi watersheds. Copeia 2004: 842-849.

Peterson, M.S., W.T. Slack, G.L. Waggy, J. Finley, C.M. Woodley, M.L. Partyka. 2006. Foraging in non-native environments: comparison of Nile tilapia and three co-occurring native centrarchids in invaded coastal Mississippi watersheds. Environmental Biology of Fishes 76:283-301

Smith-Vaniz, W. - Ichthyologist, U.S. Geological Survey, Gainesville, FL.

Tongnunui, S., and F.W.H. Beamish. 2009. Habitat and relative abundance of fishes in small rivers in eastern Thailand. Environmental Biology of Fishes 85:209-220.

Trewavas, E. 1983. Tilapiine fishes of the genera Sarotherodon, Oreochromis, and Danakilia. Publication No. 898. British Museum of Natural History, London, UK.

Wise, R.M., V.W. van Wilgen, M.P. Hill, F. Schulthess, D. Tweddle, A. Chabi-Olay, and H.G. Zimmermann. 2007. The economic impact and appropriate management of selected invasive alien species on the African continent. Council of Scientific and Industrial Research Report Number: CSIR/NRE/RBSD/ER/2007/0044/C.

Zambrano, L., E. Martínez-Meyer, N. Menezes, and A.T. Peterson. 2006. Invasive potential of common carp (Cyprinus carpio) and Nile tilapia (Oreochromis niloticus) in American freshwater systems. Canadian Journal of Fisheries and Aquatic Sciences 63: 1903-1910.

Other Resources:
Global Invasive Species Database Factsheet

US Fish and Wildlife Service Ecological Risk Screening Summary for Oreochromis niloticus

Author: Nico, L.G., Schofield, P.J., and Neilson, M.E.

Peer Review Date: 12/18/2013

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.