The complete mitochondrial genome sequence and phylogenetic analysis of Gnathopogon herzensteini(Cypriniformes, Cyprinidae, Gobioninae)

Gnathopogon herzensteini is a small-sized fish endemic to the upper reaches of the Jialing River and the Han River. Wild populations of G. herzensteini have declined sharply during the past few decades and the phylogeny of this species has not yet fully resolved. Notably, the relationship between Gnathopogon and Gobiocypris genera still remains controversial. Scientific progress is hampered by the scarcity of molecular data for G. herzensteini. To address this problem, the complete mitochondrial genome of G. herzensteini were sequenced and characterised, and used to analyse its phylogenetic position within the subfamily Gobioninae. The genome is a circular molecule of 16,597 bases, consisting of 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and a control region (D-loop). The nucleotide composition exhibited A/T bias: A 30.0%, T 27.0%, G 17.2%, and C 25.8%. Phylogenetic tree revealed that Gobiocypris clustered within the genus Gnathopogon, thus rendering it paraphyletic. The clade of genus Gnathopogon was closely related to Coreoleuciscus, with strong statistical support. These data are a stepping stone towards the understanding of genetics and phylogeny of G. herzensteini.