The status of amur beak gudgeon Microphysogobio amurensis (Taranetz 1937) inferred from complete mitochondrial genome analysis

The complete mitogenome sequence of Microphysogobio amurensis has been amplified and sequenced in this study. The overall base composition of M. amurensis mitogenome is: A (30%), C (26.8%), G (17.2%), T (26%), with an obvious A + T bias (56%). The assembled mitogenome, consisting of 16605 bp, has 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a control region. To estimate the status of M. amurensis, all available mitogenomes of Microphysogobio were downloaded from GenBank for phylogenetic analysis. The result strongly supported the traditional taxonomic hypothesis that M. amurensis was sister to M. brevirostris and M. koreensis. However, taxonomic confusion on its generic assignment remains to be further studied, as this study and other relevant molecular studies not only suggested that Microphysogobio could be divided in two major clusters (viz. the Palearctic species group and the Oriental species group), but also that two allied genera (Biwia, Rostrogobio) were embedded within the Palearctic species group of Microphysogobio.