Physa natricina Taylor 1988, junior synonym of Physa acuta Draparnaud, 1805 (Pulmonata: Physidae)

Abstract

Physa natricina Taylor, 1988 is reported as a narrow range endemic species from the Snake River in Idaho, USA and is currently protected under the federal Endangered Species Act. We examined all available type material as well as more than 1,500 specimens of Physa collected from the Snake River and adjacent areas over the past twelve years and compared them to the original descriptions and the type material. No material collected from the Snake River, nor from the paratype series, could be confidently ascribed to P. natricina using both the internal and external morphological characters defined in the original description, nor by direct comparison to the holotype. Furthermore, the holotype and paratypes all have internal and external morphology that is accommodated within the natural range of variation of the polymorphic Physa acuta Draparnaud, 1805. Therefore P. natricina is conspecific with P. acuta, a common, widespread species.