First complete mitochondrial genome of the Corydoras pygmaeus (Actinopteri: Callichthyidae) and its phylogenetic implications

The Pygmy corydoras Corydoras pygmaeus Knaack, 1966, is the smallest member of the genus Corydoras, belonging to the family Callichthyidae and order Siluriformes. The complete mitochondrial genome of C. pygmaeus was sequenced and assembled using next-generation sequencing technology, and phylogenetically compared with those of other species of this genus. The mitochondrial genome of C. pygmaeus is a circular DNA molecule with a size of 16,840 bp (GenBank no. ON729306). A phylogenetic tree was constructed based on 13 protein-coding genes of C. pygmaeus and 13 species of the family Callichthyidae, which showed that C. pygmaeus clustered with other species of this genus, but was the first branch to differentiate. These results could provide basic data for phylogenetic analysis and population genetic diversity protection of Corydoras and Callichthyidae fish in the future.