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.
The San Francisco Piranha (Pygocentrus piraya) is a fish native to the São Francisco River basin in eastern Brazil. Pygocentrus piraya has been introduced outside of its native range through accidental escapes from regional breeding farms and possibly stocking actions. This fish is found in the aquarium trade, may be a recreational target species, and bred in captivity. Pygocentrus piraya is regulated in multiple States. There are general statements that introductions have had an impact (damage to fishing nets, and competition with or predation on native fish) but no supporting information was available. The history of invasiveness is classified as Data Deficient. The climate match for the contiguous United States is medium. Most of the contiguous United States had a low match, except for small patches of medium match scattered along the coast of southern California, the Gulf Coast, and the southern Atlantic Coast. Southern Florida had a high match. The certainty of assessment is low due to a lack of supporting information about impacts. The overall risk assessment category for Pygocentrus piraya is Uncertain.