Preliminary molecular phylogenetic relationships of Helminthoglypta land snails (Mollusca: Gastropoda: Helminthoglyptidae) from northern California and southern Oregon, USA

Abstract

The land snail genus Helminthoglypta is broadly distributed from northern Baja California Norte, Mexico, through California, to southern Oregon, USA. Its taxonomy has been largely based on characters of the shell and reproductive system, with previous molecular studies limited to arid and desert taxa. Here we investigate the molecular relationships among Helminthoglypta taxa occurring in the forests of northern California and southern Oregon using fragments of the mitochondrial gene cyto-chrome c oxidase subunit I (COI) and the mitochondrial large ribosomal subunit (16S). Most of the taxa identified on morphological criteria appear as monophyletic clades in our analyses. Exceptions include the mixing of H. hertleini and H. cypreophila in a single clade, the possible differentiation of H. talmadgei into 2 clades, and the presence of an undescribed species in southern Oregon. Because Helminthoglypta species likely reflect the health of the forest ecosystems in which they occur, accurate species identifications are essential for meaningful results from survey and monitoring programs; our preliminary findings suggest that further studies are needed to fully resolve Helminthoglypta diversity in this region.