Seasonal gut contents of introduced Allegheny Crayfish (Faxonius obscurus) in an eastern Pennsylvania stream

Abstract

Crayfish are important components of many freshwater ecosystems and play key roles as detritivores and/or carnivores. However, dietary studies are lacking for many species. Few data are available on the diet of Allegheny Crayfish (Faxonius obscurus), a common species native to western Pennsylvania and historically introduced into the central and eastern portions of the commonwealth. We collected Allegheny Crayfish from a site in eastern Pennsylvania from April to October and dissected specimens to evaluate the seasonal diet of this species. We found that gut contents in all months sampled primarily consisted of organic detritus (e.g., dead leaves and woody debris) and inorganic detritus (e.g., sand and silt), with small quantities of macroinvertebrate material and negligible vegetal material (macrophytes or algae). Generally, the diet of this species is similar those of other crayfish in the genus Faxonius.