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.
Oreochromis macrochir, Longfin Tilapia, is a fish species native to Africa. It has been introduced extensively into reservoirs and rivers in Africa outside of its native range, and it has also become established in Israel and Hawaii. It is utilized in aquaculture and as a sportfish. Numerous U.S. States prohibit or restrict the trade, possession, or use of O. macrochir. This species been implicated in the decline of native fish species in Lake Alaotra, Madagascar, but it was introduced along with carp and several other tilapia species, so this decline cannot be attributed specifically to O. macrochir. Decline of sport fisheries in Hawaii has been attributed to the introduction and proliferation of multiple species of exotic tilapia in reservoirs. History of invasiveness is “none documented.” O. macrochir has a medium climate match with the contiguous United States, with the areas of high match located in Florida and along much of the border with Mexico. Further research is needed to determine what impacts, if any, can be definitively attributed to introductions of O. macrochir. Certainty of this assessment is low, and the overall risk assessment category is uncertain.
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Uncertain Risk
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