Ecological Risk Screening Summary - Oscar (Astronotus ocellatus) - Uncertain Risk

Species that are considered uncertain risk need a more in-depth assessment beyond the Ecological Risk Screening Summary to better define the species’ risk to U.S. environments.

Astronotus ocellatus, Oscar, is a fish native to northern South America. This species is popular in the aquarium trade, as a sport fish, and as a food fish. Due to the large size this species can obtain, it is likely that many introductions have occurred by humans translocating aquarium pets, although this species has also been intentionally stocked as a sport fish outside of its native range and may also escape from aquaculture facilities. A. ocellatus was included by the State of Florida in a 1993 health advisory warning people about eating freshwater fish contaminated with mercury. A. ocellatus has been introduced to multiple U.S. States as well as internationally, but it is reported as established only in Hawaii, Florida, Puerto Rico, Guam, and Australia. The impacts of these introductions are largely unknown. In Brazil, introductions of A. ocellatus, Pygocentrus nattereri, and Cichla cf. monoculus have been associated with the disappearance of native species from several water bodies, although the distinct contributions of A. ocellatus to these native species losses were not identified. A variety of other potential impacts have yet to be documented in the nonnative range. The History of Invasiveness is therefore Data Deficient. The climate matching analysis for the contiguous United States indicates establishment concern for this species. The climate match was highest where the species is already established in southern Florida, with other areas of high match found along the southern Atlantic Coast and parts of the northern Gulf Coast and southern Texas. The Certainty of Assessment is Low due to limited available information on actual impacts of introduction, plus taxonomic uncertainty. The Overall Risk Assessment category for Astronotus ocellatus in the contiguous United States is Uncertain.