A Systematic Study on the Opossum Shrimp Tribe Mysini (Crustacea: Mysida: Mysidae) from Korea: Taxonomy and DNA Barcoding

Abstract

A systematic study of the tribe Mysini in Korean waters was carried out on the basis of morphology and DNA barcoding. Samples were collected from intertidal zone, tidal pools, and subtidal zone at 29 localities. As a result of this study, 15 species of 8 genera belonging to the tribe Mysini were identified. Of these, three species, Exacanthomysis japonica Murano, 1991, Nipponomysis calcarata Takahashi and Murano, 1986, Nipponomysis fusca (Ii, 1936) were recorded for the first time in Korea and the genus Exacanthomysis Holmquist, 1981 was also newly reported from Korea. These species were fully described and illustrated in this study. For DNA barcoding in species level, 42 individuals of 13 species were sequenced in mitochondrial cytochrome c oxidase subunit I (mtCOI). All species represented enough barcode gap except three species: Nipponomysis fusca (Ii, 1936), Neomysis intermedia (Czerniavsky, 1882), and Paracanthomysis hispida Ii, 1936. They showed relatively low interspecific sequence divergence indicating ambiguous barcode gap. However, these species can be distinguished among them by the following morphological characters: 1) the number of segment of fourth pleopod in male, 2) shape of antennal scale apex, rostrum, and telson. Therefore, in order to understand the current results, more morphological and additional molecular analysis should be required. Specimens obtained in the study were described with taxonomic remarks, and illustrated with photographs. A list and a key for the tribe Mysini of Korean mysids including previously known 16 other species are provided herein.