Complete mitochondrial DNA sequence of the giant water bug Kirkaldyia deyrolli (Hemiptera: Belostomatidae)

Giant water bugs (genus Kirkaldyia and Lethocerus) are well known species from aquatic habitats throughout the world's subtropical and tropical areas. Only one species of the Kirkaldyia deyrolli is distributed in Japan. K. deyrolli has been designated as second category rare species according Law for Conservation of Endangered Species of Wild Fauna and Flora in Japan, in 2019. We analyzed, for the first time, the complete mitochondrial genomes of the giant water bug K. deyrolli from Japan using next-generation sequencing. The mitochondrial genome was a circular and 15,579 bp molecule that included 13 protein-coding genes (PCGs), 22 tRNA genes, and two ribosomal RNA genes, along with one AT-rich control region. The AT content value was 69.55%. The heavy strand was predicted to have nine PCGs and 15 tRNA genes, whereas the light strand was predicted to contain four PCGs, seven tRNA genes, and two rRNA genes. Start codons were variable for all PCGs: four ATA, three ATC, four ATG, two ATT genes as the start codon. Stop codons were of two types: TAA for 12 genes and TAG for one gene. Incomplete stop codon T was identified. The molecular phylogenetic relationship, inferred using 13 PCGs, was consistent with that reported in previous studies, which predicted a sister relationship to the genus Lethocerus.