Genetic analysis and population genetic structure of hard-shelled mussel, Mytilus coruscus Gould 1861 (Mytiloida: Mytilidae) from the coasts of South Korea based on mitochondrial cytochrome oxidase (COI) gene sequences

Background Mytilus coruscus Gould, 1861 is a mussel species in the family Mytilidae, native to the Northwest Pacific Ocean, ranging from the East China Sea, the Yellow Sea, and as far as the Peter the Great Gulf in the East Sea. In Korea, this species has been heavily exploited for nutrient-rich food resources and experienced severe reduction in their population. Objective The aim of this study was to investigate the genetic diversity and population structure and to provide baseline data to facilitate the conservation and sustainable use of the vulnerable species M. coruscus in South Korea. Methods Mitochondrial DNA (mtDNA) cytochrome c oxidase I (COI) sequences of 91 adult individuals from four islands and one coastal localities in South Korea were sequenced. We then compared genetic diversity and haplotype data with previously published Chinese wild populations. Results Mytilus coruscus populations on Korean coasts were found to exhibit high genetic diversity despite concerns regarding recent population reduction. A total of 42 haplotypes were defined by 56 polymorphic sites. High-level genetic diversity was observed on four Island sites (Hd = 0.906-0.955, pi = 0.0068-0.0090). The other seashore site represented relatively lower genetic diversity (Hd = 0.529, pi = 0.0011) and was genetically differentiated from the others. In a previous study, wild populations on the East China Sea exhibited similarly high genetic diversity as that observed in our study. Additionally, Chinese M. coruscus populations exhibit a distinct regional haplotype distribution pattern while sharing six haplotypes with Korean populations. Conclusions The results of this study provide insights that further the current understanding regarding the evolution of M. coruscus species and provides comprehensive genetic data to facilitate the development of an effective conservation strategy.

Automated summary

Despite concerns over population reduction, Mytilus coruscus populations in Korean coasts exhibit high genetic diversity. A distinct genetic pattern was observed in Korean populations compared to Chinese wild populations, with shared haplotypes between the two.