The zoogeography and centers of origin of the crayfish subgenus Procericambarus (Decapoda : Cambaridae)

The Central Highlands region in the central United States is a taxonomicall y diverse region with a high incidence of stream endemism. Based on the dis tributions of the diverse ichthyofauna in the region, a pre-Pleistocene pat tern of diversity due to vicariant events has been proposed to explain high levels of endemism and species richness. We tested this hypothesis using c rayfish phylogenies and distributional patterns for species distributed in the Central Highlands region. We concluded that both pre-Pleistocene and Pl eistocene hypotheses are compatible with the crayfish distributions and the se distributions are likely due to a combination of both vicariant and disp ersal events. Furthermore, we suggest a Pleistocene center of origin for th e crayfish subgenus Procericambarus within the Ozark region and a pre-Pleis tocene center of origin for the genus Orconectes within the Eastern Highlan ds region.