Ecological Risk Screening Summary - Ringed Crayfish (Faxonius neglectus) - High Risk

Species that are considered high risk have a well-documented history of invasiveness in at least one location globally, and a high or medium climate match to the contiguous United States.

Ringed Crayfish (Faxonius neglectus) is a crayfish native to the southern and western Plains region of the United States. It has been introduced into drainages adjacent to its native range as well as in the northeastern and northwestern United States. No information is available on specific introduction events, but introduction may have occurred through bait-bucket release, aquarium release, or release with stocked fish. F. neglectus has displaced two native crayfish species in the Spring River drainage of Missouri and Arkansas, although researchers have yet to identify the mechanisms by which this displacement has taken place. F. neglectus has also been found in caves in southern Missouri and may threaten vulnerable species within those ecosystems. At least 10 U.S. States regulate F. neglectus at the species or family level. Due to the documentation of established populations outside of its native range and the documented negative impacts from reliable sources the History of Invasiveness is classified as High. The climate matching analysis for the contiguous United States indicates establishment concern for this species outside its native range. Most of the contiguous United States had high or medium matches. The Certainty of Assessment is classified as High. The Overall Risk Assessment Category for Faxonius neglectus is High.