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

This is the fifth in a recent series of papers on the poorly known western North American pebblesnail genus (Caenogastropoda, Lithoglyphidae). Herein we clarify the taxonomic status of the currently undescribed pebblesnail fauna in the upper Klamath River drainage (UKL) based on morphologic evidence, and mitochondrial DNA sequence data from 58 UKL collection localities. We describe one new species () from eight UKL localities which is differentiated by mtDNA sequences and unique penial morphology, and document range extensions to the UKL for three species from closely proximal drainages (, , ).

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

We describe two new species of pebblesnails (Lithoglyphidae: ) from southwest Oregon based on morphologic and mitochondrial DNA (COI, cytB) evidence. , which had been traditionally identified as prior to the recent restriction of the latter to the lower Columbia River drainage, lives in lotic habitats in the Umpqua River basin. This species is readily distinguished from closely related and by shell and anatomical characters, and by its mtDNA sequences (divergence >3.

Three new species of western California springsnails previously confused with Pyrgulopsis stearnsiana (Caenogastropoda, Hydrobiidae).

We describe three new, allopatric species of springsnails (genus Pyrgulopsis) from western California (Pyrgulopsis lindae, Pyrgulopsis ojaiensis, Pyrgulopsis torrida) that were previously identified as Pyrgulopsis stearnsiana. The new species are differentiated from Pyrgulopsis stearnsiana and each other both by mtCOI sequences (3.9-9.

Taxonomic status of the Columbia duskysnail (Truncatelloidea, Amnicolidae, Colligyrus).

Undescribed freshwater snails (Amnicolidae: Colligyrus) from the Mount Hood region (northwestern United States) identified as a new species (commonly known as the Columbia duskysnail) in grey literature have been provided federal protection under the "survey and manage" provisions of the Northwest Forest Plan and have been placed on conservation watch lists. However, there are no published studies of the identity of these snails aside from a molecular phylogenetic analysis which delineated a close relationship between the single sampled population and Colligyrusgreggi, which is distributed more than 750 km to the east of the Mount Hood area. Here we examine the taxonomic status of the Columbia duskysnail based on additional molecular sampling of mitochondrial DNA sequences (COI) and morphological evidence.

Assembly of a micro-hotspot of caenogastropod endemism in the southern Nevada desert, with a description of a new species of Tryonia (Truncatelloidea, Cochliopidae).

Newly obtained and previously published sequences of the cytochrome c oxidase subunit I (COI) gene were analyzed to examine the biogeographic assembly of the caenogastropod fauna (belonging to the families Assimineidae, Cochliopidae, and Hydrobiidae) of an isolated spring along the lower Colorado River in southern Nevada (Blue Point Spring). Based on available COI clock calibrations, the three lineages that comprise this fauna are 2.78-1.

Taxonomic revision of the Pyrgulopsis gilae (Caenogastropoda, Hydrobiidae) species complex, with descriptions of two new species from the Gila River basin, New Mexico.

We describe two new species of springsnails (genus Pyrgulopsis) for populations from the middle Fork and upper East Fork of the Gila River Basin (New Mexico) that had been previously identified as P. gilae. We also restrict P.

Systematics of a widely distributed western North American springsnail, Pyrgulopsis micrococcus (Caenogastropoda, Hydrobiidae), with descriptions of three new congeners.

We describe three new species of springsnails (genus Pyrgulopsis) from the Amargosa River basin, California and Nevada (P. licina sp. n.

Pushing short DNA fragments to the limit: Phylogenetic relationships of 'hydrobioid' gastropods (Caenogastropoda: Rissooidea).

Although phylogenetic studies are increasingly utilizing multi-locus datasets, a review of GenBank data for the Gastropoda indicates a strong bias towards a few short gene fragments (most commonly COI, LSU rRNA, and SSU rRNA). This is particularly the case for the Rissooidea, one of the largest and most taxonomically difficult gastropod superfamilies. Here we analyze fragments of these three genes from 90 species to determine whether they can well resolve higher relationships within this superfamily, whether structurally aligned sequence datasets increase phylogenetic signal, and whether the inclusion of highly variable regions introduces noise.

Redescription of Marstonia comalensis (Pilsbry & Ferriss, 1906), a poorly known and possibly threatened freshwater gastropod from the Edwards Plateau region (Texas).

Marstonia comalensis, a poorly known nymphophiline gastropod (originally described from Comal Creek, Texas) that has often been confused with Cincinnatia integra, is re-described and the generic placement of this species, which was recently allocated to Marstonia based on unpublished evidence, is confirmed by anatomical study. Marstonia comalensis is a large congener having an ovate-conic, openly umbilicate shell and penis having a short filament and oblique, squarish lobe bearing a narrow gland along its distal edge. It is well differentiated morphologically from congeners having similar shells and penes and is also genetically divergent relative to those congeners that have been sequenced (mtCOI divergence 3.

Molecular systematics and radiation of western North American nymphophiline gastropods.

Three mitochondrial DNA (mtDNA) markers were used to infer the phylogenetic relationships of the morphologically diverse, species rich, and poorly understood western North American aquatic gastropod genus Pyrgulopsis (Hydrobiidae: Nymphophilinae). Sequences were obtained from 62 of 124 currently recognized species of Pyrgulopsis and representatives of four related genera of North American nymphophilines. Separate and combined analyses of the mtDNA datasets recovered a well supported clade composed of Pyrgulopsis and two other North American nymphophiline genera (Floridobia, Nymphophilus) consistent with the results of a prior study based on a single gene and with anatomical evidence suggesting that these taxa form a monophyletic group.

A molecular phylogeny of aquatic gastropods provides a new perspective on biogeographic history of the Snake River Region.

Mitochondrial DNA sequences of aquatic gastropods of the subgenus Pyrgulopsis (Natricola) were analyzed to test a commonly accepted hypothesis concerning the early history of the Snake River in the northwestern US. Distributions of Natricola and other regional biota were previously used to infer that the Snake River flowed to the Pacific through southeastern Oregon and northern California during the Neogene prior to its capture by the Columbia River in the late Pliocene (2 Ma). A molecular phylogeny based on partial sequences of COI and NDI (1149 bp) indicates that the Natricola clade is restricted to the modern Snake-Columbia River Basin and the Oregon Lakes region whereas northern California populations previously assigned to this subgenus belong to other lineages.

Mitochondrial DNA sequences reveal extensive cryptic diversity within a western American springsnail.

We analysed cytochrome c oxidase subunit I and NADH dehydrogenase subunit I sequence variation among 29 populations of a widely ranging southwestern springsnail (Pyrgulopsis micrococcus) and 18 regional congeners. Cladistic analyses of these sequences depict P. micrococcus as a polyphyletic composite of five well-supported clades.