Cooperative Fish and Wildlife Research Units Program: Arkansas
Education, Research and Technical Assistance for Managing Our Natural Resources

Crayfish are extremely important in most freshwater systems, typically acting as keystone species. There are multiple crayfish species of greatest conservation need in the Ozark Highlands of Arkansas and Missouri. The Mammoth Spring crayfish, Orconectes marchandi, and the Coldwater Crayfish, Orconectes eupunctus, are two of our most geographically restricted stream crayfish and are considered imperiled in Arkansas, Missouri and globally, and candidates for listing by the USFWS. Hubbs’ crayfish, Cambarus hubbsi, is another narrow range endemic occurring in north-central Arkansas and south-central Missouri. The threat of an advancing invasive species, along with potential habitat loss and fragmentation, makes determining potential invasive species effects, population status and population genetics of these species extremely important. We propose to determine population status of Orconectes marchandi, Orconectes eupunctus, and Cambarus hubbsi by comparing abundance and occupancy rates from 1998-1999 to those from a recent study in 2010-2011. We will also examine population genetics of Orconectes marchandi and compare current and historical genetic diversity. We will use genetic data to examine population structure, gene flow among sub-populations, and potential ESU’s for O. marchandi. Simulation models will be used to determine potential effects of an invasive crayfish on O. marchandi, O. eupunctus, and C. hubbsi populations.