• Animal cells and systems
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• v.14 no.1
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• pp.59-71
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• 2010

Gammarus gageoensis n. sp., a new species of freshwater gammarid, was collected from Gageodo Island, South Korea. This new species is characterized in terms of its morphology by the flagellum of antenna 2 with calceoli, the pereopods 3 and 4 with numerous long curled setae on the posterior margins, the terminal article of the outer ramus in uropod 3, which is longer than the adjacent spines, and the presence of both rami with long simple setae. The morphological characters of the new species that are different to related species are presented in the text. This paper also compares the new species to related species by the partial sequence of the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene. The sequence difference, consisting of a 39-44% difference relative to closely related species, is also large enough to designate this gammarid as a different species from other freshwater gammarid species. This is the first finding of a new species of Korean freshwater gammarid since 1992. Including this new species, a total of 10 species are known to Korea.

• Parasites, Hosts and Diseases
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• v.51 no.6
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• pp.739-742
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• 2013

A 52-year-old woman presented with lower back pain, progressive symmetrical paraparesis with sensory impairment, and sphincter disturbance. Magnetic resonance imaging (MRI) of the whole spine revealed multiple intradural extramedullary serpiginous-mass lesions in the subarachnoid space continuously from the prepontine to the anterior part of the medulla oblongata levels, C7, T2-T8, and T12 vertebral levels distally until the end of the theca sac and filling-in the right S1 neural foramen. Sparganosis was diagnosed by demonstration of the sparganum in histopathological sections of surgically resected tissues and also by the presence of serum IgG antibodies by ELISA. DNA was extracted from unstained tissue sections, and a partial fragment of mitochondrial cytochrome c oxidase subunit 1 (cox1) gene was amplified using a primer set specific for Spirometra spp. cox1. After sequencing of the PCR-amplicon and alignment of the nucleotide sequence data, the causative agent was identified as the larva of Spirometra erinaceieuropaei.

• ALGAE
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• v.33 no.1
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• pp.37-48
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• 2018

Alaria is the second largest genus of the Laminariales, which is distributed far into the northern Pacific and Atlantic oceans. Due to its high morphological plasticity, over 100 specific and sub-specific names have been used in Alaria, this has been tailored down to the present 17 species through morphological revision and molecular phylogenetic analysis. Endemic species of Alaria from Russian Far East have not been thoroughly revised since their original description, and few of them were confirmed using molecular data until recently. We carried out morphological and molecular studies on A. paradisea which is an endemic species distributed on the Kurile Islands, first described by Miyabe and Nagai in 1932 as Pleuropterum paradiseum. The range of morphological variability and its distribution was re-evaluated using the type specimen as well as other specimens. Analyses of partial mitochondrial cytochrome c oxidase subunit 1 and nuclear-encoded internal transcribed spacer sequences showed that A. paradisea nested within the genus Alaria, but differs morphologically from any other Alaria species in having additional sporophylls with a central midrib (${\beta}-sporophylls$). Our results showed that A. paradisea clearly belongs to the genus Alaria based on DNA data, although the key morphological character that was used to include this species to the genus Pleuropterum, ${\beta}-sporophylls$, is stable and distinguishes it from other Alaria species.

• Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.137-143
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• 2014

The hairtail (currently recognized as Trichiurus lepturus in Korea) is one of the most important commercial fish species in Korea, Japan, China, and Taiwan. Because the amount of catches has been steadily declining, we must determine the early life stages of the hairtail from the viewpoint of resource management. Furthermore, the taxonomic status of the hairtail is unclear among ichthyologists, potentially creating management difficulties. Therefore, the purpose of this study was to compare morphological and molecular information on eggs, larvae, and adults of hairtail from Korea with that of T. lepturus from the Atlantic Ocean, and to review the taxonomic status of the hairtail. A total of 510 base pairs of the mitochondrial DNA cytochrome oxidase subunit I sequences of 12 eggs, 2 larvae, and 11 adults of the hairtail from the Korean waters clearly matched those of Trichiurus japonicus adults (d = 0.000-0.014) from the East China Sea rather than those of T. lepturus (d = 0.100-0.110) from the Atlantic Ocean. Our results also showed that larvae of the Korean hairtail are different than those in the Atlantic Ocean in having no melanophores along the ventral edge of the lower jaw. Therefore, our findings suggest that the hairtail in the Korean waters may not be T. lepturus, but T. japonicus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.4
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• pp.444-449
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• 2018

Two specimens of Scomberoides tol (99.0 mm and 124.5 mm in total length), belonging to the family Carangidae, order Perciformes were collected from Korean waters using a gape net with wings and a hand net between 2014 and 2017. These specimens are characterized by having the origin of the soft-rayed portion of the dorsal fin just above the origin of the soft-rayed portion of the anal fin, dorsal spines not connected by fin membranes and posterior end of the maxilla and upper jaw not extending beyond the posterior margin of the eye. A comparison of mitochondrial DNA cytochrome c oxidase subunit I sequences indicated that these specimens matched Scomberoides tol (K2P distance, d = 0.002), but differed from other Scomberoides species (6.9-9.1%). This is the first reliable report of Scomberoides tol from Korea.

• ALGAE
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• v.32 no.1
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• pp.29-39
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• 2017

Geographic distributions of pathogens are affected by dynamic processes involving host susceptibility, availability and abundance. An oomycete, Pythium porphyrae, is the causative agent of red rot disease, which plagues Pyropia farms in Korea and Japan almost every year and causes serious economic damage. We isolated an oomycete pathogen infecting Pyropia plicata from a natural population in Wellington, New Zealand. The pathogen was identified as Pythium porphyrae using cytochrome oxidase subunit 1 and internal transcribed spacer of the rDNA cistron molecular markers. Susceptibility test showed that this Pythium from New Zealand was able to infect several different species and genera of Bangiales including Pyropia but is not able to infect their sporophytic (conchocelis) phases. The sequences of the isolated New Zealand strain were also identical to Pythium chondricola from Korea and the type strain from the Netherlands. Genetic species delimitation analyses found no support for separating P. porphyrae from P. chondricola, nor do we find morphological characters to distinguish them. We propose that Pythium chondricola be placed in synonymy with P. porphyrae. It appears that the pathogen of Pyropia, both in aquaculture in the northern hemisphere and in natural populations in the southern hemisphere is one species.

• Animal Systematics, Evolution and Diversity
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• v.37 no.3
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• pp.235-241
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• 2021

To provide better taxonomic information of the genus Nectoneanthes, the two DNA barcode regions of mitochondrial cytochrome c oxidase subunit I (COI) and 16S ribosomal DNA (rDNA) sequences of Nectoneanthes oxypoda and N. uchiwa were determined. In addition, the respective sequences of four nereidid species closely related to Nectoneanthes were retrieved from GenBank for comparison and to estimate intra- and inter-specific genetic distances. The aligned sequence lengths of COI and 16S rDNA were 570 bp and 419 bp long, respectively. The mean intraspecific variation in both markers was less than 1% in all species except for that in COI of H. diadroma (1.87%). The mean interspecific variation between N. oxypoda and N. uchiwa was 12.02% regarding COI and 1.85% regarding 16S rDNA. In contrast, the mean interspecific variation between species of other genera was comparably higher(i.e., genus Perinereis: 20.5% in COI and 8.3% in 16S rDNA; genus Hediste: 13.18% in COI and 2.64% in 16S rDNA), compared with that between the two Nectoneanthes species. This result indicated that these Nectoneanthes species are genetically more closely related than other congeneric species of different genera. The DNA barcoding information on Nectoneanthes species generated in this study provides valuable insights for further biodiversity studies on nereidid species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.146-153
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• 2022

The vertical distribution and abundance of icthyoplankton in the southern waters of Jeju Island during June 2020 were investigated. Fish eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and the 16S rRNA gene. During this period, fish eggs of 23 taxa belonging to 21 families and larvae of 27 taxa belonging to 25 families were collected. Fish eggs were located mostly from the surface to 30 m depth of the water column. Larvae were located from the surface to 80 m depth of the water column. Vertical distributions of fish eggs and larvae were influenced by oceanography conditions such as temperature, salinity, and thermocline depth. No discernible difference in mean thermocline depth was observed between day and night.

• 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".

• 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.