Arizona Hydrobiidae (Prosobranchia: Rissoacea)

Hershler, Robert; Landye, J.

The general study of mollusks in Arizona includes collection of springsnails in Organ Pipe Cactus National Monument (ORPI). Tryonia quitobaquitae Hershler is listed as a new species, with Quitobaquito Springs listed as the type locality (p. 50). Also included is a section (pp. 23-30) on the Montezuma Well springsnail (Pyrgulopsis montezumensis Hershler), a new species endemic to Montezuma Well and its upper 100 meters of outflow, with Montezuma Well listed as the type locality. A diverse fauna of Arizona Hydrobiidae is documented as a result of recent collecting from numerous springs in the state. The fauna is composed of 14 species in two genera, Pyrgulopsis Call and Pilsbry and Tryonia Stimpson. Thirteen species are described as new herein and the fourteenth represents a new state record. All have relatively restricted distributions, and two are single-spring endemics. All congeners are allopatric to one another. Stepwise canonical discriminant function analyses using sets of shell and anatomical data confirmed the distinctiveness of the 12 species of Arizona Pyrgulopsis, as classification of (grouped) topotypes was 89%-93% using shell data, and 100% using anatomical data. Discriminant analyses also confirmed that differentiation among congeners largely involves male anatomy (especially penial features), as this data set yielded the best separation of species in plots of discriminant function scores. (Copied verbatim from the report.) Bibliography, 49 figures, 6 tables, 3 appendices

Arizona Hydrobiidae (Prosobranchia: Rissoacea)

Series