Two new, possibly threatened species of Pyrgulopsis (Gastropoda: Hydrobiidae) from southwestern California

Abstract

Here we describe (for conservation purposes) two new species of Pyrgulopsis from southwestern California based on morphologic and molecular (mtCOI) evidence. Pyrgulopsis castaicensis n. sp. is endemic to a single spring in the upper portion of the Santa Clara River basin and may be threatened by the proposed development of a master-planned community (Newhall Ranch) near Santa Clarita Valley. This snail differs from two morphologically similar regional congeners (P. micrococcus [Pilsbry in Stearns, 1893], P. stearnsiana [Pilsbry, 1899]) by its larger terminal gland, simple oviduct coil and mtCOI sequences (6.1–9.3% for P. micrococcus, 3.5–8.2% for P. stearnsiana). Pyrgulopsis milleri n. sp. is distributed in spring-fed waters along a short reach of upper Tule River drainage and threatened by surface water diversion and its close proximity to a major road (CA 190). Pyrgulopsis milleri differs from closely similar and geographically proximal P. stearnsiana in its broader central cusps on the central radular teeth, shorter pallial section of the albumen gland, greater overlap of the bursa copulatrix by the albumen gland, simple anterior vas deferens, usual absence of a terminal gland and mtCOI sequences (2.8–8.4%).