Characterization of the complete mitochondrial genome of Khawia sinensis belongs among platyhelminths, cestodes

- This is the first time to report the full mitochondrial genome of Khawia sinensis.
- By genetic analysis, we found Khawia sinensis closely related to species from Diphyllobothriidae.
- The complete mitochondrial genome of Khawia sinensis will provide useful information for the study of species identification, molecular epidemiology and population genetics.

Khawia sinensis is an important species in freshwater fish causing considerable economic losses to the breeding industry. This is the first mt genome of a caryophyllidean cestode characterised. The entire mt genome of K. sinensis is 13,759 bp in length. This mt genome contains 12 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes and two non-coding regions. The arrangement of the K. sinensis mt genome is the same as other tapeworms, however, the incomplete stop codon (A) is more frequent that other species. Phylogenetic analyses based on concatenated amino-acid sequences of the 12 protein-coding genes of 17 tapeworms including K. sinensis were conducted to assess the relationship of K. sinensis with other species, the result indicated K. sinensis was closely related with cestode species. This complete mt genome of K. sinensis will enrich the mitochondrial genome databases of tapeworms and provide important molecular markers for ecology, diagnostics, population variation and evolution of K. sinensis and other species.