Molecular phylogeny of the western North American pebblesnails, genus Fluminicola (Rissooidea: Lithoglyphidae), with description of a new species

Abstract

The northwestern North American freshwater gastropod genus Fluminicola (Caenogastropoda, Lithoglyphidae) was previously hypothesized to be paraphyletic based on morphologic data, with F. virens positioned outside the clade containing other congeners. We further evaluated the phylogenetic relationships of Fluminicola using mitochondrial cytochrome c oxidase subunit I (COI) gene sequence data from 22 of 24 previously described congeners, a new congener (F. gustafsoni) that closely resembles F. virens morphologically, representatives of four other lithoglyphid genera, and several outgroups. A Bayesian analysis resolved two well supported Fluminicola clades, consistent with morphological heterogeneity. The clade composed of F. virens and F. gustafsoni was sister to the rest of the Lithoglyphidae; the clade containing the remaining congeners was sister to Somatogyrus. Our results confirm that Fluminicola is paraphyletic. However, this genus cannot be revised until the phylogenetic relationships of its possibly extinct type species are resolved. The new species described herein, F. gustafsoni, differs from F. virens in its smaller size, medium-convex and prominently shouldered teleoconch whorls, weakly angled shell aperture, presence of a well-developed rectangular wing on the outer marginal radular teeth, vertically oriented coiled oviduct, and in its COI sequences. Fluminicola gustafsoni is distributed in riverine habitats in the lower Snake River watershed.

A new species and range extensions for three other species of pebblesnails (Lithoglyphidae, Fluminicola) from the upper Klamath basin, California–Oregon

“…The cytB dataset also included sequences from 13 Fluminicola species (a cytB sequence is not available for F.gustafsoni Hershler & Liu). Given that cytB sequences are not available for other North American lithoglyphid genera, basally positioned F.virens was used to root the trees based on this dataset (Hershler et al 2007; Hershler and Liu 2012). Sample codes, locality and voucher details, and GenBank accession numbers for the sequences used in the molecular phylogenetic analyses are in Suppl.…”

“…This is the fifth in a recent series of papers on the freshwater pebblesnails (Lithoglyphidae: Fluminicola ) of the Pacific Northwest, USA. The previous contributions in this series, which treated the faunas in the Rogue–Umpqua (Hershler et al 2017), upper Sacramento River (Hershler et al 2007), and Snake River watersheds (Hershler and Liu 2012; Liu et al 2013), increased the number of Fluminicola species from 9 to 27 and also documented large range extensions for F.coloradoense Morrison, 1940 and F.multifarius Hershler, Liu, Frest & Johannes, 2007.…”

Two new species of Fluminicola (Caenogastropoda, Lithoglyphidae) from southwest Oregon, USA, and a range extension for F. multifarius

“…Both morphological (Hershler and Frest 1996) and molecular (Hershler and Liu 2012) evidence suggest that the 25 currently recognized Fluminicola species belong to two evolutionarily distinct lineages. One of the lineages contains two species in the Columbia River basin – F. gustafsoni Hershler & Liu, 2012; F. virens (Lea, 1838) – while the other (containing the remaining congeners) is distributed in this drainage and also the Great Basin, upper Colorado River basin, and Sacramento River basin.…”

“… Fluminicola ( Truncatelloidea , Lithoglyphidae ) is a western North American genus of small freshwater gastropods with globose to conical shells, commonly known as pebblesnails, which is distributed in diverse habitats ranging from small seeps to spring-influenced lacustrine reaches to large rivers. Both morphological ( Hershler and Frest 1996 ) and molecular ( Hershler and Liu 2012 ) evidence suggest that the 25 currently recognized Fluminicola species belong to two evolutionarily distinct lineages. One of the lineages contains two species in the Columbia River basin – F. gustafsoni Hershler & Liu, 2012; F. virens (Lea, 1838) – while the other (containing the remaining congeners) is distributed in this drainage and also the Great Basin, upper Colorado River basin, and Sacramento River basin.…”

“…The broad geographic range of Fluminicola includes most of the Pacific Coastal watershed from northern California to southern British Columbia. Pebblesnail populations are scattered throughout much of this huge area, yet are currently undescribed aside from six species in the Columbia River basin ( Hershler and Frest 1996 , Hershler and Liu 2012 , Liu et al 2013 ) and 14 species in the Sacramento River basin ( Hershler et al 2007 ). This taxonomic knowledge gap is hampering efforts by the conservation community to obtain legal protection for pebblesnails (e.g., USFWS 2012 ), which are groundwater-dependent and threatened by various anthropogenic activities.…”