Molecular and morphological evidence reveals a hidden new taxon in the endemic genus Pseudocuneopsis (Bivalvia, Unionidae) from China.

A new species of freshwater mussel belonging to the genus Pseudocuneopsis , namely Pseudocuneopsiswuana sp. nov. , is diagnosed and described from Guangxi Province, China. This paper provides a detailed shell morphological description, soft-body anatomical characteristics, and partial sequences of mitochondrial COI as DNA barcode data for the novel species. The new species can be distinguished from its congeners ( Pseudocuneopsissichuanensis , P.yangshuoensis , and P.capitata ) by shell shape, beak position, and surface sculpture. Phylogenetic analyses based on the mitochondrial COI gene reveal that Pseudocuneopsiswuana sp. nov. forms a sister group with P.yangshuoensis and exhibits an interspecific genetic distance of 5.1%. Therefore, we provide robust morphological and molecular evidence to support the validity of this new species.