DNA barcoding supports reclassification of JapaneseChironomusspecies (Diptera: Chironomidae)

Abstract

Non‐biting midges (Diptera: Chironomidae) adapt to species‐specific environmental conditions and hence are promising bioindicators for aquatic and ecotoxicological monitoring. Although their utility for these purposes was historically limited by difficulties in their morphological identification, DNA barcoding offers a possible solution. Here, eight Japanese species of the genus Chironomus, which is characterized by its worldwide distribution and abundance among Chironomidae, were subjected to DNA barcoding using cytochromec oxidase subunit I (COI). To examine whether this DNA barcode is a useful indicator for Japanese species of Chironomus, we calculated genetic distances within and between the COI sequences of Chironomus species both from this study and worldwide and constructed phylogenetic trees. Based on 415 bp COI sequences and the Kimura two‐parameter model, the average genetic distances within 37 species and between 72 species were 2.6% and 17.2%, respectively. Although the ranges of genetic distances within and between species overlapped from 0.8% to 17.3%, 99.7% of average genetic distances between species were >3.0%. Some of this overlap is attributable to distances within species that were “too large” as well as those between species that were “too small”. Of eight Japanese species examined, two showed genetic distances between species that were below a 3.0% threshold, and four had distances within species that were greater than 3.0%. These results suggest a possible reclassification of these species and the need for further sampling to unveil biogeographic variations among different countries and regions.

Chironomus strenzkei Fittkau, 1968 is a junior synonym of C. striatipennis Kieffer, 1910

“…Chaudhuri et al 1992;Amora et al 2015, Martin 2017, and molecular analysis, with some limited cytological studies (Nath and Lakhotia 1989, and Gupta and Kumar 1991, Martin 2017. Those used for molecular analysis are listed in Pramual et al (2016) and confirmed the conclusion from morphological and cytological studies, that C. kiiensis (group B of Kondo et al 2016) was a junior synonym of C. striatipennis. Kondo et al (2016) considered only the Barcode sequences and concluded from these that they were identical or close relatives.…”

“…Those used for molecular analysis are listed in Pramual et al (2016) and confirmed the conclusion from morphological and cytological studies, that C. kiiensis (group B of Kondo et al 2016) was a junior synonym of C. striatipennis. Kondo et al (2016) considered only the Barcode sequences and concluded from these that they were identical or close relatives. Adults had been made available to Amora et al (2015) for their studies, so were not available for further study.…”

Congruence between molecular and morphological systematics of Alpine non‐biting midges (Chironomidae, Diamesinae)

“…Professional taxonomists are becoming rare even among biologists (Hopkins & Freckleton, 2002) and rapid and efficient tools might support the evaluation of biodiversity, especially those that are DNA‐based. Recent studies showed that DNA barcoding using a short sequence (ca 658 bp) of the mitochondrial COI in particular (Kondo et al., 2016; Kranzfelder et al., 2017; Pfenninger et al., 2007; Pramual et al., 2016) enables a fast and reliable taxon identification to species‐level of whole or even parts of specimens across any life stage (Hebert et al., 2003; Rach et al., 2017). Thus, it offers great promise in advancing freshwater bioassessment and monitoring routines (e.g.…”

Mitochondrial divergence suggests unexpected high species diversity in the opsariichthine fishes (Teleostei: Cyprinidae) and the revalidation of Opsariichthys macrolepis

“…Genetic divergence is generally measured by the estimated pairwise distance between sequences, such as the p-distance, or more commonly, the distance calculated by the Kimura's 2-parameter (K2P) model (Kimura, 1980;Kondo, Ueno, Ohbayashi, Golygina, & Takamura, 2016). In this study, genetic distance was calculated with MEGA 5.0 (Tamura et al, 2011) with the default parameters and 1,000 bootstrap replicates under K2P model.…”