
Theses and Dissertations
Date of Award
12-1-2024
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Biology
First Advisor
Kathryn E. Perez
Second Advisor
Matthew Terry
Third Advisor
Frederic Zaidan
Abstract
The springsnail genus Pyrgulopsis is one of the most diverse groups of freshwater gastropods in North America (Hershler, 2014), with many species displaying high levels of endemism (Hurt, 2003). This study attempts to circumscribe three putative species of springsnails: Pyrgulopsis serrata, Pyrgulopsis marcida, and a newly identified clade, referred to as Lineage C, from the Ruby Lake National Wildlife Refuge, Nevada, USA and nearby springs. Using an integrative taxonomic approach, we combined morphological, anatomical, and molecular data to examine species boundaries and evolutionary relationships.
Many lines of evidence were considered to determine species boundaries. Phylogenetic analysis of the mitochondrial cytochrome oxidase I (COI) gene supported the distinctiveness of Lineage C, forming a well-supported monophyletic clade sister to P. sterilis and separate from P. serrata and P. marcida. However, pairwise genetic distances (p-distances) between Lineage C and the other species ranged from 2.1% to 2.6%, which is below the expected “DNA barcoding” threshold for Pyrgulopsis. The combined morphological and anatomical results, with differences in shell morphology and radular structure, suggest that Lineage C represents a distinct species. These data also support P. marcida and P. serrata as distinct species.
The findings of this study have important implications for the conservation of these springsnails, which are highly vulnerable due to their restricted ranges and dependency on groundwater-fed habitats. The integrative approach employed here, combining genetic and morphological data, underscores the importance of multi-faceted taxonomic studies in understanding biodiversity and informing conservation efforts.
Recommended Citation
Meadows, Trenton, "How Many Tiny Snails? Circumscription of Three Species of Pyrgulopsis (Mollusca: Gastropoda: Hydrobiidae)in Nevada Mountain Springs" (2024). Theses and Dissertations. 1630.
https://scholarworks.utrgv.edu/etd/1630
Comments
Copyright 2024 Trenton Meadows. https://proquest.com/docview/3153338581