Lieb, D. A., R. W. Bouchard, and R. F. Carline. 2011. Crayfish fauna of southeastern Pennsylvania: distributions, ecology, and changes over the last century. Journal of Crustacean Biology 31:166-178.
Abstract
We describe the current distributions and relative abundances of southeastern Pennsylvania’s crayfish; changes in the region’s crayfish
fauna over the last century; and, where pertinent, the relationship of the current fauna to site-specific characteristics, basin-wide
attributes, and exotic crayfish. The crayfish fauna currently inhabiting the region bears little resemblance to the historical assemblage.
Whereas historical surveys yielded Orconectes limosus and Cambarus bartonii, both native species, recent collections produced eight
species including five exotics. Many areas occupied by exotic Orconectes no longer support O. limosus. Cambarus bartonii was found in
a number of invaded systems, but was typically a minor component of the crayfish community and may not be able to persist in those
systems indefinitely. The distribution of Cambarus (Puncticambarus) sp., an undescribed member of the Cambarus acuminatus
complex, was extremely limited, with populations only found in four streams, all of which are threatened by urbanization and exotic
crayfish. Exotic species collections include the first published records for Procambarus clarkii in Pennsylvania and extend the ranges of
Orconectes virilis and Orconectes obscurus in the state by . 150 km. These results indicate the need for conservation and management
initiatives aimed at preserving the native crayfish that remain in southeastern Pennsylvania.