Systematic studies of the Orconectes juvenilis complex (Decapoda : Cambaridae), with descriptions of two new species

The juvenilis complex of the crayfish genus Orconectes has been problematic for over 100 years. Morphological variation across the range of the comple x was examined to determine species boundaries and geographic distribution. Multivariate and univariate analyses of characters support the recognition of O. juvenilis and warrant the descriptions of two new species, O. ronald i and O. cristavarius. The shape of the form I male pleopod, the shape of t he rostrum, and the length of the areola are the most useful characters for diagnosing species within the O. juvenilis complex. A key to members of th e O. juvenilis complex is provided.