Taxonomic characterization of Tanakia species (Acheilognathidae) using DNA barcoding analyses

Abstract

Tanakia is a bitterling genus with six species found in Far East Asia. Our aim was to construct the standard DNA barcode database available for the identification of six Tanakia species by comparing the range of intra- and inter-specific genetic distances, identifying the phylogenetic placement of each Tanakia species and providing the unique barcode characteristics that are specific to each species, using cytochrome oxidase I (COI) and cytochrome b (cyt b). Both loci failed to create a perfect barcoding gap between the ranges of inter- and intra-specific genetic distances, though interspecific COI distances were sufficiently greater than intraspecific values with only a few exceptions. In our phylogenetic analyses, T. koreensis and T. signifer did not form a monophyletic cluster of haplotypes in both loci. COI provided clear nucleotide characteristics that distinguish each species, whereas relatively fewer informative sites were found within the range of cyt b. Overall, COI could be regarded as appropriate species identification solution in Tanakia. Our analyses yielded some taxonomic issues that need the further investigation, and are expected to be helpful in the examination for the conservation status of Tanakia species that are on the verge of being endangered.

Keywords:

• DNA barcode
• cytochrome oxidase subunit I
• cytochrome b
• Tanakia
• Acheilognathidae

Acknowledgements

We thank Seigo Kawase, Inoue Yutaka and Daemin Kim for providing specimens used in our study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This works was supported by the grant from the National Research Foundation of Korea (Grant No. 2015R1D1A2A01058987).