Freshwater mussels of the family Unionidae are a diverse and ecologically significant group in aquatic ecosystems. We sequenced the maternal mitochondrial genomes of eight putative species of the East Asian endemic subtribe Cristariina and, by integrating molecular data and morphological characteristics, described a new genus and species, Acudonta baitiaoensis, and one newly recorded species for China (Cristaria truncata). Integrative taxonomy revealed three new synonyms of Anemina arcaeformis and using mitochondrial phylogenomics we clarified the intergeneric relationships within the subtribe. (Image credit: Lili Liu.)