We present the first molecular-genetic analyses of Acheilognathus chankaensis free embryos floodplain lake of the Razdolnaya River basin (Primorsky region, Russia). Examination of 115 Nodularia douglasiae individuals revealed 24 infested bivalves hosting 219 free embryos (length 3–5 mm). Genetic analysis of 23 specimens via cox1 mtDNA sequencing confirmed identity with A. chankaensis populations from Northeast China and South Korea. Phylogenetic reconstruction (Bayesian inference, maximum parsimony, maximum likelihood) of six Acheilognathinae genera resolved nine generic groups and two distinct lineages of A. chankaensis: sensu stricto (11 haplotypes in haplogroups A1 (Primorye−Korea−Heilongjiang) and A2 (Yangtze basin)) and a polyphyletic A. chankaensis sensu lato group. Our results demonstrate possible post-glacial dispersal patterns via connected drainages (haplogroup A1), ancient vicariance in South China (haplogroup A2), and taxonomic discordance requiring revision of A. chankaensis s.l.
Vainutis et al. (Mon,) studied this question.