Three new species of western California springsnails previously confused with Pyrgulopsis stearnsiana (Caenogastropoda, Hydrobiidae)

Abstract

We describe three new, allopatric species of springsnails (genus Pyrgulopsis) from western California (P. lindae, P. ojaiensis, P. torrida) that were previously identified as P. stearnsiana. The new species are differentiated from P. stearnsiana and each other both by mtCOI sequences (3.9-9.9%) and details of penial morphology. We also provide a phylogeny with increased sampling which confirms a previous finding that P. stearnsiana sensu stricto is paraphyletic relative to two other California species (P. diablensis, P. giulianii). Our molecular and morphological evidence suggests that P. stearnsiana paraphyly is an artifact of conservative taxonomy, however additional studies utilizing rapidly evolving genetic markers will be needed to confidently tease apart the cryptic diversity in this widely ranging springsnail. The new species described herein are narrowly distributed and vulnerable to anthropogenic stressors. The single known population of P. torrida may have become extirpated between 2000 and 2015.