Insights on the evolution and conservation of Appalachian burrowing crayfishes, with the description of a new species of Cambarus Erichson, 1846 (Decapoda: Astacidea: Cambaridae)

Abstract

Abstract A new species of crayfish, Cambarus nyxn. sp., is described from the Kentucky/Tennessee border in the Dissected Appalachian Plateau sub-ecoregion of the US. Of the recognized species of Cambarus Erichson, 1846, it is morphologically most similar to Cambarus deweesae Bouchard & Etnier, 1979, found primarily in the Southern Limestone/Dolomite Valleys and Low Rolling Hills sub-ecoregion. Cambarus nyxn. sp., is distinguishable from other recognized congeners, except for C. deweesae, by the strongly serrated lateral margin of the propodi of the chelae, closed areola, two rows of palmar tubercles, truncate rostrum with convergent margins, and Form I male (MI) gonopod having a central projection shorter than the mesial process. The new species differs from C. deweesae in coloration (blue vs. red, respectively) and size at maturity only. There is considerable genetic, morphometric, and color variation among populations herein considered as members of the new species. The species has a limited range and highlights once more the need for increased conservation efforts for North American crayfishes. Genetic analysis of C. nyxn. sp. sheds light on the evolutionary process occurring in the crayfishes of the Appalachian Mountains after the origin of Cambarus.