Revisiting the North American freshwater mussel genus Quadrula sensu lato (Bivalvia Unionidae): Phylogeny, taxonomy and species delineation

Abstract

Freshwater mussels (Bivalvia, Unionidae) have suffered strong declines over the last century. High morphological plasticity of Unionidae causes disturbances in their systematics and taxonomy, hampering conservation efforts. Species that have historically been placed under the North American genus Quadrula have suffered from numerous taxonomic and species delineation problems since its inception. Four genera are presently recognized within Quadrula sensu lato, that is, Cyclonaias, Quadrula, Theliderma and Tritogonia, but their phylogenetic basis remains incompletely tested. In the present study, we reconstructed several two-marker (mtDNA cytochrome c oxidase subunit I-COI and NADH dehydrogenase subunit 1-ND1) phylogenies with newly collected specimens and all previously available sequences covering most species within this group. We then delineated the species within the group using an integrative approach with the application of molecular statistical methods, morphometric (Fourier Shape) analyses and geographic distribution data.Four clades corresponding to these genera were consistently recovered in all phylogenies. To validate the generic status of these clades, molecular analyses were complemented with morphological, anatomical and ecological data compiled from the literature. Several revisions are here proposed to the current systematics and taxonomy of these genera, including the synonymization of Cyclonaias asperata under Cyclonaias kieneriana; the inclusion of Quadrula apiculata and Quadrula rumphiana under Quadrula quadrula; the placement of Quadrula nobilis under Tritogonia; and finally the separation of the Mobile River basin populations of Theliderma metanevra as a new species, that is, Theliderma johnsoni n. sp. The conservation implications of the proposed changes are then discussed. 314 | LOPES-LIMA Et AL. F I G U R E 1 Map of all sampling sites for the present study; both tissue and shell materials in red; only shell materials in white [Colour figure can be viewed at wileyonlinelibrary.com] F I G U R E 2 Bayesian consensus tree inferred from the cytochrome c oxidase subunit I (COI) gene fragment. The values above and below the nodes indicate Bayesian posterior probability (bpp) percentage and maximum likelihood bootstrap values (bs), respectively. Values over 95% are represented by an asterisk, and those <50% are not shown for clarity [Colour figure can be viewed at wileyonlinelibrary.com] SUPPORTING INFORMATION Additional supporting information may be found online in the Supporting Information section at the end of the article. How to cite this article: Lopes-Lima M, Burlakova L, Karatayev A, et al. Revisiting the North American freshwater mussel genus Quadrula sensu lato (Bivalvia Unionidae): Phylogeny, taxonomy and species delineation. Zool Scr. 2019;48:313-336. https://doi.

New species of the genus Inversidens Haas, 1911 (Unionoida, Unionidae, Gonideinae) from Jiangxi Province, China

“…Mitochondrial cytochrome oxidase subunit I (COI) gene sequences have been widely used for species delimitation of freshwater mussels based on genetic distance and the criteria of monophyly (Elderkin et al 2016;Lopes-Lima et al 2019;Smith et al 2019). Polymerase chain reaction (PCR) amplification of the COI gene with a 680-base pair fragment was performed using a primer pair consisting of LCO1490 and HCO2198 (Folmer et al 1994).…”

Biogeography of freshwater mussels (Bivalvia: Unionida) in Texas and implications on conservation biology

“…Uniomerus tetralasmus and Uniomerus declivis were combined because surveyors have had difficulty differentiating the two based on external morphology, which has led to confusion about their distribution in Texas (Randklev et al, 2021). Quadrula apiculata was combined with Quadrula quadrula based on phylogenetic data from Lopes‐Lima et al (2019), which reported Q. apiculata as a junior synonym of Q. quadrula . Quadrula couchiana was excluded from our analysis due to uncertainties about whether it is a valid taxon given morphological similarities with Q. quadrula (Howells et al, 1996; Randklev et al, 2021), which also ranges in the Rio Grande basin.…”

Burrowing behaviour of unionid mussels in subtropical rivers: Implications for survey guidelines

“…Cyclonaias petrina and Fusconaia askewi are considered Texas endemics (Burlakova et al, 2018; Lopes‐Lima et al, 2019) and both are listed as state‐threatened species, but they can be locally abundant within their drainages. Cyclonaias pustulosa (formerly Cyclonaias aurea ; Johnson et al, 2018; Lopes‐Lima et al, 2019), Amblema plicata , and Tritogonia verrucosa are common species widely distributed throughout the Mississippian faunal region (Haag, 2012). Cyclonaias pustulosa , A. plicata , and T. verrucosa were the focus of the field study (see Section 2.3).…”