• ALGAE
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• v.33 no.1
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• pp.69-84
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• 2018

We examined the species diversity of Herposiphonia on Korean coasts, based on a combination of morphology and molecular analyses of the mitochondrial COI-5P DNA barcode marker and plastid rbcL gene. We report the presence of eight species including three novel species: H. donghaensis sp. nov., H. jejuinsula sp. nov., H. sparsa sp. nov., H. caespitosa, H. fissidentoides, H. insidiosa, H. parca, and H. subdisticha. Specimens were separated into eight clades in both the COI-5P and rbcL gene analyses, with 1.3-19.6 and 6.6-15% interspecific sequence divergence, respectively. These eight species are also distinguishable by several morphological characteristics such as: branching pattern (d/i pattern in H. donghaensis sp. nov. and H. sparsa sp. nov.; d/d/d/i pattern in others), shape of determinate branch (ligulate in H. fissidentoides; terete in others), number of vegetative trichoblasts (1-2 in H. insidiosa and H. sparsa sp. nov.; 3-4 in H. caespitosa; absent in others), and number of segments and pericentral cells in determinate branches. About three novel species revealed by our analyses, H. donghaensis sp. nov. is newly discovered, and H. jejuinsula sp. nov. and H. sparsa sp. nov. were previously reported in Korea as H. nuda and H. secunda, respectively. Our results show that DNA barcoding and rbcL analyses are useful for delimiting species boundaries and discovering cryptic species diversity in the genus Herposiphonia.

• Journal of Environmental Science International
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• v.20 no.4
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• pp.551-554
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• 2011

The production of the sharp-toothed eel by commercial catch off waters of Korea is annually declined after 1978. This study was carried out to obtain the stock management of the sharp-toothed eel using the PCR-aided RFLP method. The mtDNA COI gene was amplified using species-specific primers and PCR product was observed to 700 bp. Amplified DNA fragments were treated with six kinds of restriction enzymes (BaeHI, EcoRI, PstI, Ksp22, HinfI and HaeIII). The treatment of HaeIII showed a distinct PCR product between Yeosu/Jinhae/Jeju/Goseoung and Jangheung/Haenam populations that were observed from 300 to 400 bp in reference to 100 bp molecular marker. However, DNA fragment within populations had an identical pattern. The phylogenetic homology is 82% between two populations inferred from RFLP PCR product pattern using NTsysPC ver. 2.1. The use of HaeIII plays an important role in discriminating populations. It is thought that adults after over-wintering in the southern part of Jeju migrate to the Yeosu, Jinhae and Goseoung regions to spawn instead of to southwestern waters. Individuals within populations showed a relatively active genetic mixing and migration regardless of geography. However, the genetic ancestor of Jangheung and Haenam populations is appeared to be more adjacent to China or Japan than Jeju.

• Journal of Species Research
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• v.9 no.1
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• pp.1-10
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• 2020

A new dragonfly species, Nannophya koreana sp. nov., is described from Korea on the basis of morphology and mitochondrial cytochrome oxidase c subunit I (COI) gene sequences. Nannophya materials from Korea and other areas in Southeast Asia were compared. The new species was previously recognized in Korea as the endangered pygmy dragonfly Nannophya pygmaea Rambur, 1842, which is widely distributed in insular and peninsular Southeast Asia. However, male adults of the Nannophya population in Korea could be distinguished from other N. pygmaea populations by the presence of a thick, incomplete black stripe on the lateral synthorax that terminated at half-length (vs. continuous to wing base), light orange (vs. red) anal appendages, and 4-5 (vs. 2-3) black teeth on the ventral superior appendages. In addition, the body length of N. koreana was generally larger (1.2-1.4 times) than that of N. pygmaea, regardless of life stage. COI gene sequences from the two groups exhibited substantial genetic differences (>12%), thereby sufficiently substantiating their differentiation. The taxonomic status, distribution, and habitat of the new species are discussed.

• Animal cells and systems
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• v.16 no.4
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• pp.313-320
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• 2012

Genetic variation was surveyed at four microsatellite loci and 1416 base pairs (bp) of the mitochondrial DNA (mtDNA) cytochrome c oxidase I gene (COI) to clarify the genetic structure of the small yellow croaker, Larimichthys polyactis, in the Yellow and East China Seas, especially regarding four provisional populations, (one Korean and three Chinese populations). Based on microsatellite DNA variations, the estimated expected heterozygosity ($H_E$) in each population ranged from 0.776 to 0.947. The microsatellite pairwise $F_{ST}$ estimates showed no significant genetic differentiation between the populations. MtDNA variations also indicated no genetic structure in L. polyactis, but very high variability. The absence of genetic differentiation among and within populations of L. polyactis may either result from the random migration of the adult or the passive dispersal of the eggs and larvae.

• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.229-239
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• 2021

Thamnaconus modestus, distributed in the Northwest Pacific, has high economic value and is used in various seafood. In this study, the morphological and genetic characteristics of T. modestus and T. septentrionalis were compared and analyzed. We observed the external and internal morphology of T. modestus, sketched skeletal elements, and analyzed phylogenetic evolutionary relationships using the cytochrome c oxidase subunit I (COI) gene on mitochondrial DNA compared to T. septentrionalis. The T. modestus observed in this study had blackish-brown patterns irregularly scattered on the gray-brown body, and the fins were blue-green. Genetic analysis results based on the COI sequences of T. modestus showed seven types of base sequence variation; however, the homology was more than 98.8%. In addition, as a result of comparison of the COI nucleotide sequences and phylogenetic analysis in Tetraodontiformes, two T. septentrionalis sequences (JN813099, MW485059) were similar to T. modestus with 99% homology, and the other two T. septentrionalis sequences (EF607583, KP267619) were similar to those of species belonging to another genus Thamnaconus with 95% homology with T. modestus. It was not easy to classify the species based on morphological characteristics, and phylogenetic analysis between T. modestus and T. septentrionalis confirmed the difference in classification. These results provide the external and internal morphology of T. modestus and will be used as important information for the taxonomic study of T. modestus and T. septentrionalis.

• 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.

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.205-208
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• 2015

Some euryalid specimens were collected with fishing nets from Mipo, Gyungsangnamdo and Aewol, Jejudo Island, Korea. They were identified as Gorgonocephalus eucnemis (${M\ddot{u}ller}$ & Troschel, 1842), belonging to family Gorgonocephalidae of order Euryalida, which was new to the Korean fauna. Their molecular analyses were done with newly intended COI primers of mitochondrial cytochrome oxidase I (COI) gene for the accurate molecular identification. The Korean G. eucnemis was coincident with this NCBI species as a result of Blast analysis, which showed the 99% similarity. In the current study, three Gorgonocephalus species have been reported from Korea.

• Journal of Ecology and Environment
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• v.37 no.1
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• pp.35-39
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• 2014

The phylogenetic analysis was carried out to find out the validity of Chrysochroa coreana as a new species. The insect specimens were collected at Kaohsiung, Taiwan and Shizuoka, Japan. Partial region (532 bp) of COI was amplified and sequenced. The sequences were aligned and then analyzed. Based on the Kimura-2-parameter method, we calculated genetic distances among them. It indicated that the Korean individual of C. fulgidissima was closely related to Taiwan one with relatively low genetic distance (0.083). On the other hand, the Japanese individual was remotely related with those of Korean (0.192) and Taiwan (0.183) individuals. To clarify if the populations of C. fulgidissima from Korea, Taiwan, and Japan are different at the level(s) of subspecies, species, or genus, it is necessary that more samples of the members of the family Buprestidae should be collected and genetically analyzed.

• Animal Systematics, Evolution and Diversity
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• v.36 no.3
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• pp.258-263
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• 2020

The aim of this study is to report monotypic species, Nonparahalosydna pleiolepis(Marenzeller, 1879) for the first time from Korean waters with its DNA barcoding data. We collected individuals of the species from the subtidal zone of southern coast of Korea through scuba diving. To estimate DNA barcoding gap, the pairwise genetic distances were calculated between N. pleiolepis and its congeners (Halosydna brevisetosa Kinberg, 1856 and Lepidonotus squamatus (Linnaeus, 1758)) based on the cytochrome c oxidase subunit I gene (COI). Inter-specific genetic distances ranged from 18.7% to 24.6%, while intra-specific genetic distance within N. pleiolepis ranged from 0.3% to 0.5%. The maximum intra-specific genetic distance among the three species was 1.4%. The morphological diagnosis of N. pleiolepis with a taxonomic note on the species were also provided.

• Animal Systematics, Evolution and Diversity
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• v.35 no.2
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• pp.84-90
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• 2019

The brittle star, Amphistigma minuta H.L. Clark, 1938, was collected from Munseom Island, Jeju-do, Korea, by SCUBA diving. This species has distinct morphological features, as follows: a small disk with large papillae on the disk margin; slender arms and four arm spines at proximal; and oral parts the same as those of the genus Amphipholis. Additionally, we obtained partial sequences of the cytochrome c oxidase subunit I gene (COI) (513 bp) and compared them with sequences from Australian A. minuta and 13 other species of Amphiuridae. As a result, intraspecific pairwise distance was 0.4% between two Korean individuals and intraspecific distance between the Australian and the Korean populations was 2.6-2.8%, which indicates they should be considered as the same species. Ultimately, 15 species of the family Amphiuridae have currently been recorded in Korea, including A. minuta.