Molecular refinement of the taxonomy of Pyrgulopsis springsnails in western North America
| Authors: | Michael K. Young, Kristine L. Pilgrim, Eric S. Miskow, Chante L. Lundskog, Kathryn E. Perez, Michael K. Schwartz |
| Year: | 2026 |
| Type: | Scientific Journal |
| Station: | Rocky Mountain Research Station |
| Source: | Western North American Naturalist |
Abstract
Springsnails in the genus Pyrgulopsis in western North America have long been a dilemma for taxonomists. Defining species boundaries has been complicated by the presence of undiscovered or cryptic taxa, range over- or underestimation, species complexes representing an unknown number of species, and named species synonymous with other taxa. To address these issues, we conducted an array of molecular species delimitation analyses using sequences from up to 2 mitochondrial and 2 nuclear genes from over 5000 specimens representing 140 of the 151 currently recognized taxa. These analyses reaffirmed most species hypotheses, favored synonymy for some taxa and redrawing of species boundaries for others, and provided evidence of the presence of myriad new or cryptic taxa. There were occasional disagreements among methods and genes with respect to species boundaries, particularly within the P. pilsbryana species complex, and we also observed instances of recent hybridization and potential taxa of hybrid origin. Although these analyses clarified many of the species hypotheses within the genus, further taxonomic resolution of this group will require more spatially comprehensive and intensive field sampling coupled with greater genetic representation of individuals. We suspect that the complex evolutionary histories of members of Pyrgulopsis will constitute an ongoing challenge for characterizing the biodiversity of this group.