Pairwise sequence comparison data of the DNA barcodes of aquatic insects

This study compared the DNA sequences of cytochrome coxidase subunit I (COI) and histone H3 of Ephemeroptera, Odonata, Plecoptera, and Trichoptera in a pairwise manner, and calculated the sequence similarities based on uncorrected P-distance (number of identical sites in both sequences per total number of the sites compared). Datasets of annotated sequences, the source organisms of which are identified at the species level in taxonomy, were retrieved from INSD (GenBank/ ENA/ DDBJ) as of the end of May 2020. Similarity scores of the pairwise comparison were sorted by the combinations of taxonomic groups; intraspecific variations, intrageneric-interspecific divergences, intrafamily-intergeneric divergences, and intraorder-interfamily divergences for Ephemeroptera, Odonata, Plecoptera, and Trichoptera. Similarity scores at the cumulative relative frequency points (1%, 5%, 10%, and median) may be used as the threshold to differentiate between the taxonomic groups based on sequence match. This is often done in the characterization of morphologically-unidentified specimens using barcode sequences, in the metabarcoding analysis of the local fauna, and environmental DNA analysis.