Ecological Risk Screening Summary - Least Crayfish (Cambarellus diminutus) - Uncertain Risk

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.

Cambarellus diminutus is a small freshwater crayfish native to southern Alabama and Mississippi. It is known from less than 20 locations, but can be abundant at those locations. C. diminutus is present but rare in the pet trade in the U.S. and Europe. There is potential for species introduction to new ecosystems through aquarium releases and escape from garden ponds, but no established populations have been reported outside the native range. Researchers based in the Czech Republic reported a medium risk category according to the Freshwater Invertebrate Invasiveness Scoring Kit (FI-ISK). Climate match with the United States is medium, with highest match centered around the species’ native range. Without any evidence of population establishment outside the native range and a low rate of trade, overall risk posed by this species is uncertain.