Morphological Variation among Populations of the Western Slimy Salamander on the Edwards Plateau of Central Texas

Abstract

We conducted a morphometric analysis on Western Slimy Salamanders, Plethodon albagula, from each of the five mitochondrially defined groups that occur on the Edwards Plateau of central Texas. Although several groups are similar in body size and/or shape, multivariate analyses do find significant differences among groups, and several groups have clear differences for one or several characters. Thus, for several between-group comparisons, the morphological data are consistent with the mitochondrial data in arguing for cryptic lineages of slimy salamanders on the Edwards Plateau. These results demonstrate that despite the common interpretation of morphological conservatism in plethodontids, detailed morphometric studies can be used in taxonomic and evolutionary investigations of these salamanders. Lastly, male central Texas P. albagula are found to have a larger mean body size than females; this pattern of sexual size dimorphism (SSD) is reverse from that observed in nearly all other plethodontids with SSD.