• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.189-194
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• 2022

Unidentified postflexion larva (18.57 mm in standard length, SL), belonging to the family Synodontidae was collected from Jeju Island, Korea, in November 2019. Molecular analysis revealed that the unidentified larva was identical to Synodus kaianus adults in mtDNA cytochrome c oxidase subunit I region (Kimura-2-parameter distance, d= 0.006), and was different from the close species S. macrops (d=0.220). The postflexion larva of S. kaianus has the following morphological features: regularly distributed seven peritoneal pigment spots along the alimentary canal; and, intensively distributed stellate melanophores at the middle of the base of caudal fin and behind the last anal fin ray. The postflexion larva of S. kaianus differed from that of S. macrops in snout length and size of peritoneal pigment spots. This is the first record of S. kaianus in Korea, and we suggest the Korean name "Ka-i-ya-kkoch-dong-myeol" for S. kaianus, according to Lee et al. (1999).

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.4
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• pp.221-226
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• 2022

A filarial nematode was found in a blood sample of an Anas falcata individual collected in South Korea in 2018. Phylogenetic analysis based on partial cytochrome C oxidase subunit I (COI) sequences placed the nematode as a novel genus of the family Onchocercidae and as closely related to Mansonella species, Chandlerella quiscali, and filarial nematodes recently reported in avian species. However, different phylogenetic relationship was observed in the NADH dehydrogenase subunit 5 and 12S rRNA-based phylogenetic trees, which might indicate the filarial nematode found in this study was not defined to belong to the known specific genera of the family Onchocercidae. The screening of 105 additional avian blood samples retrieved only one 12S rRNA-targeting polymerase chain reaction (PCR)-positive sample, which indicates that filarial nematode infection is rare in wild birds or that it occurs below the detection limit of PCR in blood samples. Nevertheless, considering the recent findings about ancient interactions between birds and human pathogenic filarial nematodes and their pathogenic potential in several avian species, additional exploration of novel filarial nematodes in wild birds remains necessary.

• Parasites, Hosts and Diseases
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• v.60 no.3
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• pp.201-205
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• 2022

Babesia microti is one of the most common causative agents of babesiosis. A sensitive and rapid detection is necessary for screening potentially infected individuals. In this study, B. microti cytochrome c oxidase subunit I (cox1) was selected as the target gene, multiple primers were designed, and optimized by a recombinase-aided amplification (RAA) assay. The optimal primers and probe were labeled with fluorescein. The sensitivity of fluorescent RAA (fRAA) was evaluated using gradient diluents of the cox1 recombinant plasmid and genomic DNA extracted from whole blood of B. microti infected mice. The specificity of fRAA was assessed by other transfusion transmitted parasites. The analytical sensitivity of the fRAA assay was 10 copies of recombinant plasmid per reaction and 10 fg/µl B. microti genomic DNA. No cross-reaction with any other blood-transmitted parasites was observed. Our results demonstrated that the fRAA assay would be rapid, sensitive, and specific for the detection of B. microti.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.569-574
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• 2023

A single specimen (30.35 mm standard length) of Ptereleotris evides was collected from the southern coast of Jejudo Island, Korea, in September 2017 during a skin diving outing. Ptereleotris evides is characterized by having a slightly elongated body, six spines on the 1^st dorsal fin, one spine and 25 soft rays on the 2^nd dorsal fin, 22 pectoral fin rays, one spine and four soft rays on the pelvic fin, one spine and 25 soft rays on the anal fin, and no disc in pelvic fin. This species differs from the congeneric species, P. hanae and P. heteroptera in having no elongated rays on the caudal fin and a black spot at the ventral margin of the caudal peduncle, respectively. Molecular analysis results based on mitochondrial DNA cytochrome c oxidase subunit I (COI) sequences showed that our specimen almost corresponded to P. evides (99.82%) sequences from registered at the NCBI. As this is the first record of P. evides in Korean waters, we propose a new Korean name for it, "Ga-mak-cheong-hwang-mun-jeol".

• Journal of Species Research
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• v.12 no.2
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• pp.174-179
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• 2023

Three newly recorded rotifers were collected through surveys of several islands in Korea: Lecane perplexa (Ahlstrom, 1938); Lindia torulosa Dujardin, 1841; and Monommata maculata Harring & Myers, 1930. These species represent 24th, second, and third records of each genus discovered in Korea, respectively. Lecane perplexa and Monommata maculata, were collected from reservoirs using plankton nets, whereas Lindia torulosa was collected from a soil sample. The morphological characteristics of the discovered species are as follows: Lecane perplexa is characterized by a straight or slightly concave anterior margin of the lorica, an incomplete transverse fold on the ventral lorica, and a single toe with pseudoclaws and accessory claws; Lindia torulosa has an illoricated and vermiform body, a head with rostrum, a pair of auricles, cardate type trophi, and distinctively shaped epipharynx components; and Monommata maculata is characterized by long toes, an inner margin of rami with 10-12 serrated teeth, 3-4 large teeth, and interlocking teeth. Here, the morphological characteristics of the three Korean monogonont rotifers, which include trophi photographs, are presented. In addition, partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI) of each species are presented.

• Animal Systematics, Evolution and Diversity
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• v.38 no.1
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• pp.14-19
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• 2022

Leptochiton Gray, 1847 is one of the most ancient chiton groups which includes more than 130 species that occur in cold and deep waters worldwide. Due to their small-sized body, they are often confused as juveniles of other chiton species. Moreover, lack of morphological information makes species identification of this group very challenging. To date, only two Leptochiton species(L. fuliginatus and L. rugatus) have been reported from Korean waters. In this study, we found L. hakodatensis(Thiele, 1909) for the first time in Korea and described microscopic morphological characters of valves (tegmentum sculpture), girdle scale, and radula using a scanning electron microscopy (SEM). Leptochiton hakodatensis is morphologically similar to L. fuliginatus and L. rugatus, but differently characterized by having dorso-ventrally rounded (not carinated) intermediate valves, girdle (perinotum) scales sculptured with 4-7 longitudinal ribs, and bicuspid major lateral teeth of radula. In addition to morphological examination, we determined the partial mitochondrial cytochrome c oxidase subunit I(cox1) as a DNA barcode sequence information. This is the first report that describes microscopic characters (tegmentum of valves, girdle structure, and radula) of L. hakodatensis using a SEM. This study provides a morphological basis for describing Leptochiton species and discovery of a "hidden" species of this genus.

• BMB Reports
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• v.56 no.11
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• pp.575-583
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• 2023

Mitochondria, fundamental cellular organelles that govern energy metabolism, hold a pivotal role in cellular vitality. While consuming dioxygen to produce adenosine triphosphate (ATP), the electron transfer process within mitochondria can engender the formation of reactive oxygen species that exert dual roles in endothelial homeostatic signaling and oxidative stress. In the context of the intricate electron transfer process, several metal ions that include copper, iron, zinc, and manganese serve as crucial cofactors in mitochondrial metalloenzymes to mediate the synthesis of ATP and antioxidant defense. In this mini review, we provide a comprehensive understanding of the coordination chemistry of mitochondrial cuproenzymes. In detail, cytochrome c oxidase (CcO) reduces dioxygen to water coupled with proton pumping to generate an electrochemical gradient, while superoxide dismutase 1 (SOD1) functions in detoxifying superoxide into hydrogen peroxide. With an emphasis on the catalytic reactions of the copper metalloenzymes and insights into their ligand environment, we also outline the metalation process of these enzymes throughout the copper trafficking system. The impairment of copper homeostasis can trigger mitochondrial dysfunction, and potentially lead to the development of copper-related disorders. We describe the current knowledge regarding copper-mediated toxicity mechanisms, thereby shedding light on prospective therapeutic strategies for pathologies intertwined with copper dyshomeostasis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.916-922
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• 2023

An abnormal shape of Bathyraja brachyurops was first reported from the catch of a bottom trawl in the southwest Atlantic Ocean in June 2022. Both pectoral fins of the specimen did not fuse with the head, resulting in a horn-like structure separated from the sides of the eyes. Analysis of mitochondrial DNA cytochrome c oxidase subunit I sequences showed that our specimen was perfectly matched to Bathyraja brachyurops registered with the National Center for Biotechnology Information. Our specimen possessed the following morphological features: a pair of flexible but elongated and pointed horns on the head; rough dorsal disc, densely covered with numerous small denticles on the head, anterior margin of pectoral fins and median line of the disc; a thorn between the first and second dorsal fins; and a pair of large ocelli at the base of pectoral fins. Unlike the normal B. brachyurops, our specimen had a slender clasper and no nuchal thorns, which may be related to the morphological abnormality. The horn-like structure on the head may be owing to the lack of fusion between the pectoral fins and head during early embryonic development.

• Animal Systematics, Evolution and Diversity
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• v.39 no.4
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• pp.254-263
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• 2023

Two feather mites, Brephosceles anatina Dubinin, 1951 (Analgoidea: Alloptidae) and Freyana anatina (Koch, 1844) (Pterolichoidea: Freyanidae), have been reported for the first time from the Eastern Spot-billed Duck, Anas zonorhyncha Swinhoe, 1866 (Anseriformes: Anatidae), in Korea. The genera Brephosceles Hull, 1934 and Freyana Haller, 1877 are new records of Korean fauna. The morphology of B. anatina is distinguished from three species of the lambda species group in having legs IV extending the level of setae e2 with the distal end of the tarsus in males, and the incision on the posterior margin of the hysteronotal shield triangular-shaped and distinctly longer than its greatest width in females. Freyana anatina is distinguished from F. nyrocae and F. obliquasetae in having setae ps1 with a rectangle bend in homeomorphic males, and setae ps1 obliquely ovate and divergent, with the inner canal going obliquely across the membranous part of these setae in females. This study provides morphological redescriptions of both feather mite species supplemented with partial sequences of mitochondrial cytochrome c oxidase subunit I(COI), based on specimens collected in Korea.

• Animal Systematics, Evolution and Diversity
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• v.39 no.4
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• pp.264-271
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• 2023

The edible jellyfish Rhopilema esculentum occurs in waters throughout northeastern Asia, including in Korea, China, and Japan. In Korean waters, R. esculentum has appeared in two regions (Gangwha and Muan). Based on the appearance of young medusae and coastal distribution records, these two regions may be key R. esculentum breeding sites. In the present study, we investigate and compare the genetic structure of R. esculentum in the two regions using mitochondrial sequences (16S ribosomal RNA and cytochrome c oxidase subunit I). The genetic diversity of the R. esculentum population at Ganghwa exceeded that of the population at Muan. Despite considerable geographic separation (400 km) between the two regions(Gangwha and Muan), our haplotype network suggests that the Gangwha and Muan populations of R. esculentum are related. The simple and monotonous genetic structure of the Muan population shows that R. esculentum emergence is relatively recent. In contrast, the Gangwha population shows evolution. Moreover, jellyfish of the Gangwha population are genetically diverse and remain constant despite environmental fluctuations in the Han River. The Gangwha area is considered to be the old origin of R. esculentum in Korea.