Practical information to identify and manage non-native, invasive plants and animals
The Quiet Invasion:A Guide to Invasive Species of the Galveston Bay Area
Tilapia sp., Oreochromis sp., and Sarotherodon sp.
| ITIS TSN: | 169809; 170114; 553244 |
| Presence: | Current Invaders |
| Habitat: | Aquatic |
| Native Range: | Africa and southwestern Middle East |
Human Health
This species poses no known human health impacts.Prohibited Lists
As of 2010, all species of the genera Tilapia, Oreochromis, and Sarotherodon are prohibited by the TPWD.Introduction Pathways
Tilapia were introduced into the U.S. via accidental release from aquaculture facilities. Tilapia were also intentionally released for stocking purposes and in some cases, may have escaped from research facilities. Tilapia have expanded their nonnative range through natural migration over large distances (Nico and Fuller 2009b).Geographic Distribution
Tilapia are distributed worldwide due to extensive use as a commercial fish species. Nile tilapia, blue tilapia, Mozambique tilapia, red-belly tilapia and hybrid tilapias are established in Texas. Blue tilapia (O. aureus) is found in Harris, Chambers, Liberty and Brazoria counties. Nile tilapia (O. niloticus) is found in Harris County (Nico 2006a; Nico 2006b; Nico and Schofield 2007; Nico and Fuller 2009b).Specific Primary Habitats
Tilapia tolerate a wide range of environmental conditions. The Nile tilapia is more likely to succeed in tropical climates, while blue tilapia can endure colder temperatures. Tilapia species are usually freshwater species but some, such as the blue tilapia and Mozambique tilapia can tolerate saline waters. Tilapia prefer temperatures of 25-30°C, but some species (blue tilapia) can tolerate temperatures as low as 8°C (MIT 2006).Ecological, Economic, or Social Impact
Tilapia species compete with native finfish species for habitat, food, and spawning areas. They form dense populations and consume large amounts of vegetation, altering the trophic structure of an ecosystem (Canonico et al. 2005).Physical Description
Tilapiine cichlids are medium sized fish, on average 15-30 cm long, but can reach up to 60 cm, weighing up to 3-4 kg (ISSG 2006e; ISSG 2008b; ISSG 2008a; ISSG 2008d). These fish are ovate in shape and laterally compressed, with most species exhibiting an interrupted lateral line. Dorsal fins have anywhere from 7-25 spines and 5-30 soft rays and anal fins display 3-15 spines and 4-15 soft rays (Kullander 1998). Cichlids are often brightly colored and many species display sexual dimorphism (physical differences between males and females in color, shape, or size) with the breeding males exhibiting brilliant blue, pink and bright green colors on their head and caudal fins (ISSG 2006e; ISSG 2008b; ISSG 2008a; ISSG 2008d).Reproduction Characteristics
Nile tilapia (O. niloticus) and blue tilapia (O. aureus) reach sexual maturity at 5-6 months. Female tilapia reproduce every two months under optimal conditions, laying 300-500 eggs per spawn. Nile tilapia spawning begins when water temperatures reach 24°C. Tilapia reproduce via external fertilization by which females deposit eggs in a nest that are fertilized by the male. Oreochromis and Sarotherodon sp. are mouthbrooders; thus, after fertilization, the female collects the eggs in her mouth and incubates them there for 1-2 weeks (ISSG 2006f).Feeding
Tilapia are omnivorous with a diet consisting of algae, vascular plants, zooplankton, fish eggs and larvae, insects and detritus (Canonico et al. 2005; ISSG 2006f).Control
Early detection is key to preventing the spread and establishment of these species and regional/local monitoring or surveillance is essential. Nonnative fish should not be released in local waterways. If found in local waters, note the location and notify the TPWD.Lists
This species belongs to the following lists:
Images
To view a larger version of an image, click on the thumbnail. Blue tilapia (Oreochromis aureus). Photo courtesy of USGS, USGS NAS Database, http://nas.er.usgs.gov. |
 Nile tilapia (Oreochromis niloticus). Photo courtesy of USGS, USGS NAS Database, http://nas.er.usgs.gov. |
 Redbelly tilapia (Tilapia zilli). Photo courtesy of USGS, USGS NAS Database, http://nas.er.usgs.gov. |