Elimia Comalensis (Gastropoda: Pleuroceridae) from the Edwards Plateau, Texas: Multiple Unrecognized Endemics or Native Exotic?

This research explored the distribution, morphological variation, and molecular systematics of Elimia comalensis (Gastropoda: Pleuroceridae) using geometric morphometrics (n = 565) and mitochondrial DNA sequences (n = 15). Elimia comalensis was originally documented as endemic to Comal Springs, Comal County, Texas, but recent collections found this species in multiple springs and drainages in Central Texas. Morphometric analyses showed a high amount of morphological overlap with no clear geographic patterning. Phylogenetic analysis of mt COI sequence data indicated that E. comalensis represents a single species, with no genetic divergence among isolated populations. We conclude that E. comalensis may be an unrecognized native exotic, a species endemic to one area that has been spread by humans and assumed to be part of the natural fauna.