• Animal Systematics, Evolution and Diversity
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• v.38 no.2
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• pp.108-112
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• 2022

An aegid species, Rocinela niponia Richardson, 1909, is a Far Eastern species known from Korean and Japanese waters. In this study, mitochondrial cytochrome c oxidase subunit I (COI) sequences of R. niponia were determined based on four specimens collected from the subtidal zone of Chujado Island, South Korea. We compared DNA barcoding data of this species with its congeners. As a result, there was no intra-specific genetic distance between the four COI sequences of R. niponia. Inter-specific distances between R. niponia and other five aegid species ranged from 23.8% to 35.6%. Morphological diagnosis and images of R. niponia are also provided as a valuable contribution toward the identification of Rocinela species in further taxonomic and ecological studies.

• Animal Systematics, Evolution and Diversity
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• v.37 no.3
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• pp.229-234
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• 2021

Scolelepis (Scolelepis) daphoinos is newly reported in Korean fauna. This species can be distinguished from its congeners by the following characteristics: the presence of reddish pigment patches on the posterior part of the prostomium, notopodial postchaetal lamellae that are partially fused to the branchiae, and the presence of only the bidentate hooded hooks. The morphological diagnosis and photographs of S. (S.) daphoinos are provided. The partial mitochondrial cytochrome c oxidase subunit I (COI), 16S ribosomal DNA(16S rDNA), and the nuclear 18S ribosomal DNA (18S rDNA) sequences from Korean specimens of S. (S.) daphoinos were determined. Species identification was supported by a comparison of DNA barcode sequences of COI and 16S rDNA with morphological examination from the specimens of type locality, China.

• Animal Systematics, Evolution and Diversity
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• v.37 no.3
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• pp.219-224
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• 2021

A hesionid species, Leocratides kimuraorum Jimi, Tanaka and Kajihara, 2017 is newly reported from the sublittoral zones (100 m depth) of the Korean coasts. This species is characterized by lateral antennae as long as the palps, peristomial membrane without papillose, peristomial dorsolateral tubercles with two round marginal lobes, and pharyngeal with terminal papillae. The intra-specific genetic distance among the cytochrome c oxidase subunit I(COI) sequences of L. kimuraorum specimens from Japan (type locality) and Korea (this study) was in the range of 0.002-0.005. The inter-specific genetic distance between L. kimuraorum and other hesionid species were 0.166-0.307. The present study is the first record of Leocratides species in Korean fauna. This paper also provides a morphological description and photographs of L. kimuraorum, with partial sequences of the mitochondrial COI based on Korean specimens.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.64-70
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• 2019

Dirofilaria immitis (D. immitis) is a filarial nematode that causes cardiopulmonary dirofilariasis in dogs. In the late stages of infection, infected dogs show one or more symptoms and advanced heart disorder with perivascular inflammation. To detect D. immitis specifically and efficiently in the early stages of infection, a duplex TaqMan qPCR assay was developed based on previous studies using primers and probes specialized to detect D. immitis cytochrome c oxidase subunit I (COI) and dog glyceraldehyde-3-phosphate dehydrogenase (GAPDH). As positive controls, plasmid DNAs were constructed from D. immitis COI or dog GAPDH and a TA-cloning vector. Simplex and duplex TaqMan qPCR assays were performed using the specific primers, probes, and genomic or plasmid DNA. The duplex reaction developed could detect D. immitis COI and dog GAPDH in the same sample simultaneously after optimization of the primer concentrations. The limit of detection was 25 copies for the simplex and duplex assays, and both showed good linearity, high sensitivity, and excellent PCR efficiency. The duplex assays for pathogen detection reduce the costs, labor, and time compared to simplex reactions. Therefore, the duplex TaqMan qPCR assay developed herein will allow efficient D. immitis detection and quantification from a large number of samples simultaneously.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.731-738
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• 2015

Nematode infection in the epithelial tissue of cultured rockfish Sebastes schlegeli was first reported in 2012. Since then, nematode infections have caused serious economic losses in rockfish aquaculture on the west coast of Korea. Taxonomic and life cycle information for this parasite are currently unknown. In this study, 18S rRNA and cytochrome c oxidase subunit I (COI) genes were used for molecular identification and polymerase chain reaction (PCR) to detect the invisible stages of this parasite. Nucleotide sequences of the 18S rRNA of the rockfish nematode showed 98% identity with that of Philometra morii. Therefore, this rockfish nematode was classified to the Philometridae family. However, we could not identify it to genus level using 18S rRNA. Its COI nucleotide sequences shared 85% and 82% identities with those of Bursaphelenchus sinensis and Philometra overstreeti, respectively. In addition, two gene-specific primer sets were designed based on the 18S rRNA gene to detect the intermediate host and nematode larvae. These primers were specific to this rockfish nematode without cross-reacting to other pathogens. The detection limit of the PCR assay using these primers was 1,000 copies of nematoda plasmid DNA. Therefore, the PCR assay described here is suitable for the detection of nematode DNA within rockfish. In addition, this PCR assay could be used to detect nematode larvae and the intermediate host.

• Genomics & Informatics
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• v.10 no.3
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• pp.206-211
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• 2012

DNA barcoding has been widely used in species identification and biodiversity research. A short fragment of the mitochondrial cytochrome c oxidase subunit I (COI) sequence serves as a DNA bio-barcode. We collected DNA barcodes, based on COI sequences from 156 species (529 sequences) of fish, insects, and shellfish. We present results on phylogenetic relationships to assess biodiversity the in the Korean peninsula. Average GC% contents of the 68 fish species (46.9%), the 59 shellfish species (38.0%), and the 29 insect species (33.2%) are reported. Using the Kimura 2 parameter in all possible pairwise comparisons, the average interspecific distances were compared with the average intraspecific distances in fish (3.22 vs. 0.41), insects (2.06 vs. 0.25), and shellfish (3.58 vs. 0.14). Our results confirm that distance-based DNA barcoding provides sufficient information to identify and delineate fish, insect, and shellfish species by means of all possible pairwise comparisons. These results also confirm that the development of an effective molecular barcode identification system is possible. All DNA barcode sequences collected from our study will be useful for the interpretation of species-level identification and community-level patterns in fish, insects, and shellfish in Korea, although at the species level, the rate of correct identification in a diversified environment might be low.

• Journal of fish pathology
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• v.36 no.2
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• pp.403-408
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• 2023

Mullet is an important marine aquaculture fish species in Korea, with a total of 7,237 tons produced as of 2022, making it the 5th most produced marine aquaculture fish species. In this study, ectoparasites presumed to be isopods were discovered in the fins of farmed flathead grey mullet (average weight 550 g), and the characteristics of the parasites were confirmed. The length of the parasite was 5 to 18 mm, and 3 to 7 parasites were infected per fish. To analyze the characteristics of the parasites, molecular biological identification and phylogenetic analysis were performed using the cytochrome c oxidase subunit I (COI) gene, and it was confirmed to be most closely related to Nerocila japonica in the Cymothoidae family. To confirm the parasite control effect, a direct exposure drug sensitivity test was conducted on five types of aquatic drugs and fresh water, trichlorfon was confirmed to be effective.

• Korean Journal of Ecology and Environment
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• v.53 no.3
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• pp.286-294
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• 2020

The Chironomus(Diptera: Chironomidae) is a freshwater benthic invertebrate that is an important indicator organism used for environmental pollution and water quality monitoring. In this study, we performed morphological classification and genetic species identification using the cytochrome c oxidase subunit I (COI) gene on mitochondrial DNA for an accurate species classification of Chironomus larvae found in tap water purification plants in Incheon, Korea. Twenty larvae in six water purification plants consist of four species, including twelve Chironomus kiiensis, six Chironomus flaviplumus, one Chironomus dorsalis, and one Polypedilum yongsanensis (not included Genus Chironomus). Morphological characteristics of each larvae were identified based on the head capsule, the mentum, the mandible, the antenna, and the claw. Based on the COI sequences of 21 individuals of 17 Chironomus species registered in NCBI Genbank, phylogenetic analysis indicated that the 20 individuals investigated in this study consist of the same clade with corresponding species of the high homology (99~100%) including C. kiiensis, C. flaviplumus, C. dorsalis, and P. yongsanensis. These results will be used as main classification indicator for monitoring freshwater ecosystems by providing integrated morphological and genetic information for the species identification of Korean Chironomus.

• Animal Systematics, Evolution and Diversity
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• v.35 no.2
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• pp.63-72
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• 2019

Four feather mites, Alloptes(Apodalloptes) orthogramme Gaud and Mouchet, 1957, Alloptes(Conuralloptes) limosae Dubinin, 1951, Alloptes (C.) procerus Gaud, 1972 and Alloptes (Sternalloptes) fauri Gaud, 1957 are reported for the first time in South Korea. These specimens were collected from four charadriiform bird species: Actitis hypoleucos, Larus crassirostris, Limosa limosa, and Numenius phaeopus. The family Alloptidae Gaud, 1957 and a genus Alloptes Canestrini, 1879 are newly added to the invertebrate fauna of South Korea as well. Here, we provide the morphological description and illustrations based on the present specimens. Additionally, partial sequences of the mitochondrial cytochrome c oxidase subunit I(COI) were newly-generated for using as DNA barcodes.

• Korean Journal of Ecology and Environment
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• v.55 no.3
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• pp.212-220
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• 2022

An estuary is a water ecosystem with a high abundance of the species diversity, due to a variety of complex physicochemical factors of the area where freshwater and ocean mixed. The identification of Corbicula species in the estuary environments is difficult because of various morphological characteristics. In this study, we provide taxonomic information on Corbicula species with taxonomic difficulties using morphological and genetic analysis. This study was conducted on clams from the Seomjin River-Gwangyang Bay, one of the major production area of marsh clam in Korea. As a result, we characterized Cytocrome C Oxidase subunit I (COI) sequences of the Corbicula. The 636 bp nucleotide sequences of COI have 98% homology among Corbicula species collected from 2 sites of Seomjin River-Gwangyang Bay. The phylogenetic analysis with 17 species of Corbicula indicated that most of the species collected from Seomjin River-Gwangyang Bay were brackish water clam (Corbicula japonica), and only one Asian clam (Corbicula fluminea). The evolutionary distance between C. japonica and C. fluminea was less than 0.003. Therefore, it was confirmed that C. japonica is phylogenetically closely related to C. fluminea. In 9 species of Cyrenidae, phylogenetic tree was classified into three lineages. These results will be used as an important data for an identification of clam species by providing genetic information for Corbicula species with a morphological diversity.