A New Relict Species of Slender Salamander (Plethodontidae: Batrachoseps) with a Tiny Range from Point Arguello, California

Abstract

Among western North American amphibian lineages, the plethodontid salamander genus Batrachoseps has undergone the most extensive radiation. Here we describe a new species in the genus from the vicinity of Point Arguello, central California. This lineage falls within the B. pacificus group, but it is differentiated from other species in the group by both molecular sequence data and morphology. It is geographically disjunct from its close relatives, with a tiny range in unlikely habitat along a narrow strip of the Pacific Coast, where it is entirely surrounded by B. nigriventris, a distant relative. Although intraspecific molecular variation is almost entirely absent, some population structure was detected across the 4 km extent of its range. Because of its tiny range and limited genetic variation, the impacts of any potential modifications to its known habitat should be evaluated to ensure the species' continued conservation.