A study was conducted to investigate the species diversity of the genus Amphora in relation to environmental settings in Ulleungdo and Dokdo. Although Amphora is one of the most speciose genera in marine habitats, its recorded diversity in Korean waters has been relatively low compared to similar ecosystems. In this study, light microscopy (LM) and scanning electron microscopy (SEM) were employed to examine the morphology and ultrastructure of Amphora taxa. Specimens were collected from four stations across intertidal and subtidal habitats. As a result, Amphora arcuata and Amphora bigibba var. interrupta were documented for the first time in Korean waters. Amphora arcuata was found at two subtidal sites(20m depth), whereas A. bigibba var. interrupta occurred at all four stations, including one intertidal location (0 m depth). These findings contribute to a more comprehensive understanding of Amphora biodiversity in Ulleungdo and Dokdo, which harbor unique island ecosystems.

This study aims to discover and document amphipods from Korea, contributing to the clarification of the Korean amphipod taxonomy. As part of this effort, a newly recorded species of the lycaeid amphipod genus Lycaea Dana, 1852 was collected during a survey of Ulleungdo Island, Korea, conducted in the spring of 2023. The newly recorded species, Lycaea pulex Marion, 1874, is characterized by the structure of the propodus on both gnathopods and the inner ramus of uropod 2. This species is morphologically similar to L. bovallii Chevreux, 1900, L. intermedia, Zeidler, 2021, and L. vincentii Stebbing, 1888. However, it can be distinguished from its congeners by differences in peduncular article 3 of antenna 1, the length ratio of pereopod 4, and the morphology of the inner ramus of uropod 2. To date, only one species of the family Lycaeidae, Simorhynchotus antennarius (Claus, 1871) has been recorded in Korea. This study represents the first record of the genus Lycaea in Korean waters. Additionally, a key to species of the family Lycaeidae from Korean waters is provided.

This red-tongued pit viper (Gloydius ussuriensis) inhabits the Korean Peninsula, including inland areas as well as Baengnyeongdo, Jeju-do, and Gapado Islands. However, the taxonomic status of Gloydius ussuriensis populations, including their subspecies classification, remains unclear, as few phylogenetic or taxonomic studies have compared inland and island populations. To address this gap, we analyzed 513 individuals sampled between 2018 and 2022. Mitochondrial DNA revealed two major lineages: (1) inland, Baengnyeongdo, and Chinese populations and (2) Jeju-do and Gapado populations. Nuclear DNA analysis (K=3) identified three genetic groups, namely, inland, Baengnyeongdo, and Gapado, whereas the Jeju-do population exhibited an admixture of the inland and Gapado groups. Discriminant analysis of the 11 morphological traits indicated clear differences among the Baengnyeongdo, Gapado, Jeju-do, and inland populations. The snout-vent length was the longest in Baengnyeongdo and the shortest in the Gapado group. The ecological niche overlap between the populations was low (PI=0.4075). Based on these findings, three subspecies have been identified: G. ussuriensis ussuriensis, G. ussuriensis baengnyeongensis, and G. ussuriensis jejuensis. The Tsushima Island pit viper (G. tsushimaensis) from Japan, although classified as a separate species, showed genetic and morphological similarities to the Jeju-do-Gapado group. Further phylogenetic and taxonomic studies are needed for G. ussuriensis island populations in southwestern Korea, which were not included in this study.