Species that are considered uncertain risk need a more in-depth assessment beyond the Risk Summary to better define the species’ risk to U.S. environments.
Poeciliopsis gracilis, Porthole Livebearer, is a small livebearing fish native to Mexico and Central America. It is used in the aquarium trade. This species has been introduced and become established outside of its native range in the United States, Mexico, and Venezuela. P. gracilis can become abundant where introduced. Impacts to native fish populations have been documented for communities of nonnative fishes to which P. gracilis belongs, but not for P. gracilis individually. The history of invasiveness is classified as “none documented.” P. gracilis is a host to the pathogenic parasite Gyrodactylus cichlidarum, which presents a threat to tilapia aquaculture. P. gracilis has a medium climate match with the contiguous United States. The areas of the highest match are in the far southern and southwestern United States, especially in Arizona, California, Florida, Nevada, and Texas. Because no negative impacts of introductions of this species have been conclusively documented, certainty of this assessment is low. Overall risk assessment category is Uncertain.
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Uncertain Risk
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