Species that are considered high risk have a well-documented history of invasiveness in at least one location globally, and a high or medium climate match to the contiguous United States.
Coptodon rendalli, the Redbreast Tilapia, is a fish species native to a wide range of fresh and brackish waters in tropical and subtropical Africa. It has been introduced widely outside its range in Africa for aquaculture and weed control, and it is also a commercial and recreational fishing target. C. rendalli has been introduced to parts of Africa outside the native range, Central and South America, Thailand, Turkey, and some Pacific islands. In the United States, C. rendalli is established in Hawaii and Puerto Rico. In Madagascar, extreme population decline of an endemic fish is attributed to the impacts of C. rendalli herbivory on its habitat. Because most introductions of C. rendalli have occurred in locations where other nonnative species introductions have also occurred, the impacts of C. rendalli often cannot be separated from impacts of other nonnative species. For these reasons, the history of invasiveness is high for C. rendalli, but the certainty of the assessment is medium. C. rendalli has a medium climate match with the contiguous United States, with the highest match occurring in the southern United States. The overall risk assessment category is high.
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High Risk
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