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.
P. alleni is a freshwater crayfish native to Florida. The species was captured outside its native range in Riverside County, California, and individuals have also been captured in France and Germany. It is unknown whether these captures represent established populations. The species is available in the aquarium trade in North America and Europe, as well as a P. alleni-Procambarus clarkii hybrid. Climate match with the United States is medium, with California and eastern Texas being the most suitable climate for this species outside its native range in Florida. More research is needed to understand the impacts from introductions of this species. Overall risk posed by this species is uncertain.