Revisiting the genus Pseudocuneopsis (Bivalvia, Unionidae): Morphology, mitochondrial phylogenomics, and the description of a new species

Species diversity can be underestimated due to a lack of regional studies and limitations in research methods. China is widely recognized as one of the primary hotspots for the biodiversity of freshwater mussels as it harbours a wealth of endemic species. Pseudocuneopsis was recently established to belong to the Unioninae subfamily within Unionidae and is endemic to China. Recent research has expanded the diversity and range of distribution of this genus. However, sufficient data is required to precisely determine the phylogenetic relationships within Pseudocuneopsis. This study conducted an integrative taxonomy using morphological, COI barcode, and complete maternal mitogenome data to clarify the taxonomy of Pseudocuneopsis. Both morphological and COI barcode data supported the validity of all Pseudocuneopsis species. Furthermore, a new species, Pseudocuneopsis yemaoi sp. n. was described from a tributary of the Man River in Hubei, China. Mitochondrial phylogenomic analyses showed that P. yemaoi was closely related to P. sichuanensis and resolved phylogenetic relationship as (P. capitata + (P. yangshuoensis + (P. sichuanensis + P. yemaoi))). Our results highlight the significance of utilizing integrative classification methods. Moreover, we propose enhancing the research and preservation measures of minor streams in China, as these streams may house distinctive species.