A new spider species of the genus Pholcus Walckenaer, 1805, Pholcus osaek sp. nov., in the family Pholcidae C.L. Koch, 1850, is described from Korea. This new species belongs to phungiformes-group in the genus. It can be distinguished from its congeners by the shape and structure of genital organs of both males and females. It is found on and between rock walls in mountainous mixed forests. Additionally, the taxonomic status of Pholcus uksuensis Kim & Ye, 2014 is revalidated, re-diagnosed, and redescribed based on specimens collected from the type locality. Considering differences mentioned in the diagnosis through revalidation, P. uksuensis is regarded as a distinct species. Therefore, it should be removed from the synonymy of P. woongil Huber, 2011.

This study describes two new species, Desmoscolex (Desmoscolex) delticeps sp. nov. and Desmoscolex (Desmoscolex) obtusiseta sp. nov. Belonging to the subgenus Desmoscolex, they were discovered in subtidal habitats along the coast of Korea. Detailed morphological analyses of the two new species were conducted using differential interference contrast (DIC) microscopy and scanning electron microscopy (SEM). D. (D.) delticeps sp. nov. was collected from subtidal zones near Ulleungdo Island. It is characterized by a broadly triangular head with robust cephalic setae and centrally positioned oval amphidial fovea. Its somatic setae are arranged in 17 main rings. Its conical terminal ring ends in a long, uncovered spinneret. D. (D.) obtusiseta sp. nov. was collected from distant subtidal zones along the western coast. It is characterized by short, blunt cephalic setae situated on peduncles, a flattened anterior head, and an oval amphidial fovea with a central pore. Its somatic setae are arranged in 17 main rings. Its terminal ring tapers ventrally, ending in a short spinneret. This study highlights distinctive cephalic setae morphologies of these species, providing a deeper understanding of nematode diversity in Korean subtidal zones and contributing to the advancement of marine nematode taxonomy.

The genus Campylomyza Meigen, 1818, from the Micromyinae subfamily of the Cecidomyiidae, includes 40 known species globally. The genus Campylomyza has been primarily studied within the Palearctic region, with 39 species, 2 from the Nearctic region, and 1 from the Oriental region. As of now, four species have been documented in Korea: Campylomyza appendiculata, C. flavipes, C. furva, and C. spinata. Our research from 2017 to 2020 uncovered five previously unreported species in Korea (C. abjecta, C. aborigena, C. cornuta, C. cavitata, and C. cingulata) and introduces seven new species (C. angusta sp. nov., C. ambulata sp. nov., C. convexa sp. nov., C. cornigera sp. nov., C. hori sp. nov., C. odae sp. nov., and C. yeongyangensis sp. nov.). These findings are based on morphological evidence and DNA analysis. We present comprehensive data, including the mitochondrial COI sequences, diagnoses, detailed descriptions, and identification keys for these species. This work was supported by a grant from the National Institute of Biological Resources (NIBR), funded by the Ministry of Environment (MOE) of the Republic of Korea.

The genus Caenoscelis C. G. Thomson (Coleoptera: Cryptophagidae: Cryptophaginae) comprises approximately 30 species in the world, primarily distributed in the Holarctic region. Although 15 Caenoscelis species occur in the Palearctic region, only a single species, Caenoscelis sibirica Reitter, has been documented in Korea. In this study, Caenoscelis koreanus sp. nov. is described, and Caenoscelis ferruginea (C. R. Sahlberg) is reported for the first time in Korea. The new species can be distinguished from other Caenoscelis species by their subquadrate antennomere 10, fully developed hind wings, and male genitalia with subacute parameres and indistinctly separated lateral lobes. Illustrations of habitus, diagnostic characters, and a distribution map of Korean Caenoscelis species are provided.

Stathmopodidae, in the superfamily Gelechioidea, was first described by Edward Meyrick in 1913. This family has various characteristics, such as feeding on crops, moss, spores of fern, aphids, etc., but there is a lot of difficulty in identification due to morphological similarities between species. Therefore, it is necessary to understand the genitalia structure through dissection, but this process necessarily involves damage to the type specimen. To solve these problems, Micro-CT(Computed Tomography) which allows observation of internal structures without damage, was utilized to create a 3D model of the genitalia. In this study, the genitalia structure of Stathmopoda pedella (Linnaeus, 1761), the type species of Stathmopodidae, was imaged using Micro-CT under a resolution of 4 um conditions, providing a 3D description.

The genus Eudarcia belong to the subfamily Meessiinae was established by Clemens (1860), based on type species Eudarcia simulatricella Clemens, 1860. The genus is comprising 82 species in the world, which are wide spread and diverse throughout the Palaearctic region. Among them, nine species of Eudarcia are distributed in East Asia. In Korea four species of the genus Eudarcia have been reported to date. In the past, the subfamily Meessiinae was treated within the family Tineidae. Regier (2015) revised the addition of two families (Meessiidae, Dryadaulidae) to the superfamily Tineoidea through molecular analysis. In this study we described Eudarcia sp. as a new species, with illustration of adults and male genitalia.

During a survey of free-living marine nematodes of Korea, two new marine desmoscolecid nematodes belonging to subgenus Quadricoma Filipjev, 1922 were discovered. Tricoma (Q.) jejuensis sp. nov. and T. (Q.) unipapillata sp. nov. are described based on specimens obtained from washings of coarse sediments from eastern and southern coasts of Korea. Tricoma (Q.) jejuensis sp. nov. is characterized by having 33 quadricomoid body rings and inversion at main ring 23, pentagonal head with truncated anterior end, a pair of ocelli situated at main ring 6, somatic setae comprising of 8 pairs of subdorsal setae and 12 pairs of subventral setae, and relatively short spicules (42-46 μm long). Tricoma (Q.) unipapillata sp. nov. is characterized by 44 quadricomoid body rings and inversion at main ring 32, somatic setae comprising of 7 pairs of subdorsal setae and 10 pairs of subventral setae, globular head truncated anterior end, relatively short and stumpy cephalic setae with cuticular flange, one single naked ventral median genital papillae situated on main ring 20, and spicules with a proximally marked capitulum. Detailed morphological descriptions and illustrations of these two new species are provided in this study.

During the ichthyoplankton survey around the Chilsan Island (previously known as the biggest spawning ground of the Sciaenidae) in the southwestern sea of Korea from April to June in 2019 using ring nets, we collected a total of 12 individuals belonging to the family Sciaenidae. Using molecular methods, we identified five sciaenid species (Collichthys lucidus, Collichthys niveatus, Johnius grypotus, Nibea albiflora, and Pennahia argentata), and described and compared them on the basis of the preflexion larval stage. C. lucidus was well distinguished by the presence of occipital crests at preflexion stage. Although there were no occipital crests, preflexion larva of C. niveatus was distinguished by the absence of melanophore except for the upper part of the abdominal cavity. J. grypotus and N. albiflora were very similar morphologically, but were distinguished by myomere height (15.22-15.53% in J. grypotus vs. 11.66-12.78% in N. albiflora) in the percentage of notochord length, and eye diameter (32.58-33.37% in J. grypotus vs. 40.32-42.53% in N. albiflora) in the percentage of head length between specimens of similar size (J. grypotus: 3.22-3.23 mm, N. albiflora: 3.04-3.13 mm). P. argentata were distinguished by distribution of ventral caudal melanophore (one row of small spot in P. argentata vs. irregular patches on the central part of caudal in J. grypotus and N. albiflora). Comparative morphological studies using more diverse species must be conducted for more comprehensive understanding of the morphogenesis of Sciaenidae.

A single juvenile malacanthid specimen (Hoplolatilus chlupatyi) was collected from the South Sea of Korea and identified by DNA barcoding. This species is readily distinguished from other malacanthid species in having well developed rostral spine and elongated spines in the posttemporal and preopercle. A molecular analysis based on mitochondrial DNA COI sequences showed that this species is matched to adult H. chlupatyi (genetic distance = 0.005). Therefore, this is the first record of H. chlupatyi in Korea. We propose new Korean names, “Mu-ji-gae-og-dom-sog” for the genus Hoplolatilus and “Mu-ji-gae-og-dom” for the species H. chlupatyi.