DNA analysis of a non-native lineage of Sinanodonta woodiana species complex (Bivalvia: Unionidae) from Middle Asia supports the Chinese origin of the European invaders.

The Sinanodonta woodiana species complex includes several cryptic species-level phylogenetic lineages, the taxonomic placement of which is unclear. Here, we present the results of molecular analyses of a Sinanodonta sample from Middle Asia (Uzbekistan). The COI haplotype of the Uzbekistan lineage is similar to those of invasive Sinanodonta populations from Europe, Russia and Myanmar. We show that the non-native Sinanodonta flocks in Europe and Middle Asia originated from a single source population in China. Our results reveal that the Sinanodonta woodiana species complex comprises at least six distinct biological species: S. cf. gibba (=temperate invasive lineage), S. cf. woodiana (=tropical invasive lineage), S. schrenkii (=S. amurensis), S. ovata, S. jourdyi, and S. lucida, and two phylogenetic lineages with uncertain taxonomic names.