First confirmed report of Nassarius sinarum (Mollusca, Gastropoda) in Korea

The marine gastropod mollusc Nassarius sinarum has attracted attention due to its status as a potential invasive species and the ecological impact it may have on local environments and the fishing industry. It was observed exclusively within China initially, but its distribution now seems to have expanded into Japan and Korea. Accurate identification of N. sinarum, particularly in its juvenile stage, is vital for understanding its ecological influences and distribution patterns.This study represents the first comprehensive analysis of N. sinarum samples from Korea. It includes morphological examination, scanning electron microscopy images and molecular sequencing. Two live specimens were collected from the Yeongsan River estuary in Korea and their morphological features were analysed and compared to those of samples from China and Japan. The samples’ species were confirmed by molecular identification, based on cytochrome c oxidase subunit I (COI) and histone H3 (H3) genetic markers.It was observed that juvenile N. sinarum shells lack key species-characteristic morphological traits, such as a thick outer lip and diminishing axial ribs. However, COI marker-based molecular identification affirmed that these Korean specimens were N. sinarum. The H3 region was registered with the National Center for Biotechnology Information (NCBI) for the first time. Phylogenetic analysis of the H3 region did not resolve species distinctions within the Nassarius, suggesting that the H3 marker is not suitable for species identification within this genus. In this context, multiple genetic markers, when used appropriately, can also be applied to genus-level searches, enhancing species identification accuracy and reducing misidentification.The sequences provided in this study can serve as a valuable reference for future DNA barcoding research. Additional samples and surveys should be conducted through collaborative efforts amongst national and institutional organisations to further clarify the ecological status of N. sinarum and to investigate its distribution and potential impact around East Asia. Finally, a new Korean name, (No-lan-jul-job-ssal-mu-nui-go-dung; 노란줄좁쌀무늬고둥) has been proposed for N. sinarum

First reliable report of the Nassarius sinarum (Mollusca, Gastropoda) from Korea as an invasive species

Two live specimens of the mud snail, Nassarius sinarum, was collected from the Yeongsan River estuary in Jeollanam-do, Korea, during June 2022. The species was identified based on its morphology and DNA barcoding.Morphological descriptions and photographs of N. sinarum were used to verify its occurrence in Korean waters as an invasive species. The species is characteristic in its axial ribs, which weaken towards the outer lip. Molecular analysis of the mitochondrial DNA cytochrome oxidase subunit I gene showed that the specimen belonged to N. sinarum with 98.48–99.69% sequence similarity. The new Korean name of “No-lan-jul-job-ssal-mu-nui-go-dung; 노란줄좁쌀무늬고둥” was proposed for the species

A new species of Fogedia (Bacillariophyceae) from tidal flats of Northeast Asia

The genus Fogedia was first established in 1997 based on Navicula giffeniana as a type species. The important features of the genus were the presence of lateral area, the location of the internal raphe fissure, and the simple apical raphe endings. Later, the generic description of Fogedia has been emended with the reports of four new species to the science having the genus to include twelve members in total. A thirteenth member of the genus has been observed in tidal flats of the Yellow Sea, and here we describe the species as Fogedia orientalis sp. nov. based on observations with the light (LM) and scanning electron microscope (SEM). Regional distribution of the species in the Northeast Asia is also discussed. The new Fogedia species is morphologically similar to F. densa in terms of small cell size as wells as the absence of a lateral area, however, the density and pattern of striae are clearly different from each other. Morphological characteristics and global occurrences of the thirteen Fogedia species has been provided.N

First record of the red clingfish, Pherallodus indicus (Gobiesociformes: Gobiesocidae) from Jeju Island, Korea

A single specimen of Pherallodus indicus was collected for the first time from a tidal pool on the eastern coast of Jeju Island, Korea, in June 2017. This species is characterized by the division of the sucking disc formed from the pelvic fin into two portions, a lower jaw without mandibular canal pores, a head without preopercular canal pores, and eight dorsal and seven anal fin rays. The newly proposed Korean name for Pherallodus is “Eol-ruk-hak-chi-sok”, and the species name is “Eol-ruk-hak-chi”

First reliable record of the blue-lined octopus, Hapalochlaena fasciata (Hoyle, 1886) (Cephalopoda: Octopodidae), from Jeju Island, Korea

A specimen of the blue-lined octopus, Hapalochlaena fasciata (Hoyle, 1886) was collected from a tidal pool on the southern coast of Jeju Island, Korea, on 10 September 2015 and identified by DNA barcoding. This species is characterized by its blue middle lines on dorsal and lateral mantle and head, with development of numerous small papillae on the mantle, head, and arms. A molecular analysis of the mitochondrial DNA cytochrome oxidase subunit I gene showed that the specimen belonged to H. fasciata with 98.8% sequence similarity. The proposed Korean name is “Pa-ran-seon-mun-eo”. The present study far expanded the geographic distribution of H. fasciata, and further monitoring is to be made for this venomous octopus species

Checklist of the tidal pool fishes of Jeju Island, Korea

Seventy-six species of fishes, representing 60 genera and 34 families, were recorded from tidal pools on Jeju Island, southern Korea. The major families in terms of species were the Gobiidae (11 species), Pomacentridae (8 species), Blenniidae (6 species), and Labridae (5 species). Thirty-nine species were classified as tropical, 26 as temperate and 11 as subtropical