First Report of Mopalia middendorffii (Polyplacophora: Mopaliidae) from South Korea

다국어 초록 (Multilingual Abstract)

The genus Mopalia is one of the largest polyplacophoran genera, comprises medium- to large-sized chitons characterized by a narrow girdle covered with various corneous bristles and setae. To date, 23 species of Mopalia have been recorded globally; however, knowledge of this genus in South Korea has been restricted to only two previously documented species, Mopalia retifera and Mopalia schrencki. In this study, we report Mopalia middendorffii (Schrenck, 1862) as the third Mopalia species identified from South Korea. M. middendorffii is a medium-sized chiton that can be distinguished from its congeners by its exceptionally long setae, typically recurved and extending up to one-third of the animal’s total length. Detailed microstructural analyses of the shell and radula were conducted using scanning electron microscopy, providing critical taxonomic data to facilitate accurate species identification. Furthermore, molecular phylogenetic analyses based on partial 16S rRNA gene sequences (388 bp) were performed for 18 Mopalia species to corroborate the morphological findings. The maximum-likelihood phylogeny revealed that M. middendorffii was grouped within the same species (BP 85).