Conservation Assessment of Cambarus dubius in Pennsylvania with Distribution Notes on Lacunicambarus thomai.

Abstract

Burrowing crayfishes are poorly understood animals that face conservation and management issues due to a lack of distribution and ecological data. Within Pennsylvania, the burrowing crayfish Cambarus dubius has a limited distribution and its conservation status within the state is unranked. An assessment was conducted in southwestern Pennsylvania to assess the conservation status of C. dubius throughout its historic range. GIS-landscape data was used to analyze potential predictors of presence/absence. Six historic sites and 790 new sites were sampled for the presence of C. dubius.  Of the 796 sites sampled, C. dubius was collected from 61 sites. Active crayfish burrows were present at 137 additional sites; these are predicted to be those of C. dubius due to the structure of the burrows. Additional biological and ecological data on C. dubius are also provided. The global model produced from logistic regression analysis was unable to predict variables of presence/absence; suggestions for additional variables to better predict presence/absence of C. dubius are provided. Collections also yielded populations of Lacunicambarus thomai within the range of C. dubius and are the easternmost within Pennsylvania.