Genetic identity of Japanese Sympetrum frequens and Korean S. depressiusculum inferred from mitochondrial 16S rRNA sequences (Odonata: Libellulidae)

Abstract

The Japanese endemic Sympetrum frequens is considered as the insular vicariant of S. depressiusculum, widely distributed in the Eurasian Continent. In Korea, morphologically intermediate specimens have been collected, mixed with typical S. depressiusculum. The taxonomical status of these two species is thus questionable. To clarify their status, sequencing of mitochondrial 16S ribosomal RNA (rRNA) was performed on 77 specimens of Sympetrum species collected from Korea and Japan. The pairwise differences between 378 nucleotides of S. frequens and S. depressiusculum, including the intermediate type, revealed only minor differences (< 0.5%, average 0.48%). The neighbor-joining phylogenetic tree indicated that all S. frequens and S. depressiusculum form one clade, suggesting that they pertain to a single species. The tree also suggests that the S. frequens population from Hokkaido is different from all other populations.

Key words:

• Odonata
• dragonfly
• molecular phylogeny
• mitochondrial 16S ribosomal RNA
• Korean Peninsula
• Japanese Islands
• Sympetrum frequens
• S. depressiusculum