Molecular analyses of the genus Drunella (Ephemeroptera: Ephemerellidae) in the East Asian region

Abstract

The DNA-based identification of aquatic insects, which show high species diversity, is becoming increasingly popular because these insects are excellent indicators of the condition of the aquatic environment. Spiny crawler mayflies (Ephemerellidae) are aquatic insects known for their altitudinal stratified distribution patterns and niche partitioning at the microhabitat scale. For these reasons, they are a good bioindicator of the condition of an aquatic ecosystem. Here, we report the results of a study in which we obtained DNA barcoding data on various genotypes of spiny crawler mayfly species collected in various areas. In addition, we discuss the importance of accumulating genetic data collected from a wide area. We conducted molecular analyses of Drunella mayflies based on the mitochondrial DNA COI region and the nuclear DNA H3 region. A total of 101 specimens of 8 spiny crawler mayfly species were collected between 2013 and 2016 from 75 locations of the East Asian region, including the Japanese Archipelago, the Korean Peninsula, and the Russian Far East. We found a total of 86 haplotypes and 57 genotypes of East Asian Drunella mayflies and reinterpreted two cryptic Drunella lineages (Drunella basalis clades I and II and Drunella ishiyamana clades I and II).