• ALGAE
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• v.34 no.2
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• pp.91-97
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• 2019

Chilean species of marine macroalgae with amphitropical distributions oftentimes result from introductions out of the Northern Hemisphere. This possibility was investigated using haplotype data in an amphitropical red macroalgae present in Chile, Callophyllis variegata. Published sequence records from Canada and the United States were supplemented with new collections from Chile (April 2014-November 2015). Specimens of C. variegata were amplified for the 5′ end of the cytochrome c oxidase subunit I gene (COI-5P) and the full length nuclear internal transcribed spacer region. Haplotype networks and biogeographic distributions were used to infer whether C. variegata was introduced between hemispheres, and several population parameters were estimated using IMa2 analyses. C. variegata displayed a natural amphitropical distribution, with an isolation time of approximately 938 ka between hemispheres. It is hypothesized that contemporary populations of C. variegata were established from a refugial population during the late Pleistocene, and may have crossed the tropics via rafting on buoyant species of kelp or along deep-water refugia coincident with global cooling, representing a rare case of a non-human mediated amphitropical distribution.

• ALGAE
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• v.36 no.1
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• pp.13-24
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• 2021

The present-day genetic structure of macroalgal species reflects both geographical history and oceanic circulation patterns as well as anthropogenic introduction across native ranges. To precisely understand the genetic diversity and how the factors shape the current population structure of Gloiopeltis furcata sensu lato, we determined the mitochondrial 5' end of cytochrome c oxidase subunit I (COI-5P) sequences for 677 individuals sampled from 67 sites spanning almost the entire distribution range in Korea and Japan. Results from the phylogenetic analysis and haplotype distribution revealed eleven distinct lineages within G. furcata s.l. along the Korea-Japan coastal areas and displayed divergent phylogeographic patterns among lineages. Despite the closely related lineages distributed in same habitats as high rocky intertidal zone, they display different phylogeographic patterns among lineages. The populations from the south of Korea-Japan harbored the highest genetic diversity and unique endemism in comparison with other populations in the distribution range. This could be the evidence of southern refugia for G. furcata s.l. in the Northwest (NW) Pacific and the recent migration from native to introduced region. The reason is that an exceptional distribution pattern was found high genetic diversity in Hakodate of Japan where is the northern location in the NW Pacific. Our results imply the contemporary influence on the distribution due to current circulation pattern and anthropogenic effects. These phylogeographic findings provide the important insight into cryptic species diversity and the detailed distribution pattern of Gloiopeltis in the NW Pacific.

• Animal Systematics, Evolution and Diversity
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• v.34 no.3
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• pp.127-142
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• 2018

A new species of Eudactylopus Scott A., 1909 is described from the southern coast of Korea. The specimens were collected using a light trap set overnight at the entrance near a pier. Eudactylopus yokjidoensis n. sp. is similar to E. andrewi Sewell, 1940 and E. spectabilis (Brian, 1923) in two key respects: similar length of proximal and distal inner setae on female P2 enp-2, and modification of two subapical setae on male P2 endopod. However, E. yokjidoensis can be differentiated from the two species by following morphological characteristics: in females, the length ratio of cephalothorax/2nd-4th thoracic somites combined is smaller in E. yokjidoensis than other two species (1 : 0.8 vs. 1 : 1); antennule has nine segments (vs. 7-segmented in E. andrewi); P2 to P4 each bears a process in medial distal margin of basis, while it is just smooth in E. spectabilis; in males; the length ratio of cephalothorax to 2nd-4th thoracic somites combined is smaller in E. yokjidoensis than other two species (1 : 0.6 vs. 1 : 1 in E. andrewi and 1 : 0.8 in E. spectabilis); and P5 exopod has a comb-like innermost seta, while it is bipinnate seta in E. spectabilis. To prove the Korean species of Eudactylopus to be new, full descriptions of both sexes are given here, and the claim is supported by distinct genetic differences between E. yokjidoensis and E. spectabilis (22.3-22.7%) in the mitochondrial gene cytochrome oxidase subunit I(mtCOI) sequence.

• Journal of Embryo Transfer
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• v.10 no.2
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• pp.121-129
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• 1995

To examine the critical effect of oxygen concentration on embryonic development, in vitro fertilized embryos were cultured in media(TCM199 vs. SOF) supplemented sera(1O% FCS vs. 10% HS) with and without bovine oviduct epithelial cells under two gas atmosphere (5% $CO_2$ in air vs. 5% $CO_2$, 5% $O_2$, 90% $N_2$). Oocytes, obtained from abattoir ovaries, were matured in EGF containing TCM199 medium co-cultured with BOEC for 24 hours, followed by exposure to frozen-thawed, heparin4reated spermatozoa in TALP for 30 hours. And then early embryos(1~2 cell) were cultured in both TCM199 and SOF supplemented with 10% FCS or 10% RS under 5% $CO_2$ in air or 5% COi, 5% $O_2$, 90% $N_2$. Development to morulae and blastocysts was recorded on days 7, after the start of in vitro fertilization. The developmental rates of in vitro fertilized embryos to morulae and blastocysts cultured in SOF with BOEC under 5% $CO_2$, 5% $O_2$, 90% $N_2$(24.4%) were significantly(p<0.05) higher than cultured in SOF with BOEC under 5% $CO_2$ in air(14.1%) at seven days after in vitro fertilization. When early bovine embryos were cultured in TCM 199 and SOF under two different gas atmosphere, there were no significant differences in the developmental rates to morulae and blastocysts between supplements of 10% FCS and 10% HS. The rates of development to morulae and blastocysts were significantly(p<0.01) higher in TCM 199 with BOEC(24.7%) than TCM199 without BOEC(10.9%) under 5% $CO_2$ in air, otherwise SOF without BOEC(36.4%) were significantly (p<0.05) higher than in SOF with BOEC (24.4%) under 5% $CO_2$, 5% $O_2$, 90% $N_2$. In summary, these experiments have proved that the culture system in SOF supplemented 10% ES is effective on in vitro development of early bovine embryos under 5% $CO_2$, 5% $O_2$, 90% $N_2$. In addition, it is effective to development of bovine embryos that TCM 199 should be co-cultured with BOEC and SOF should be cultured without somatic cells under two different gas atmosphere.

• Korean Journal of Ichthyology
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• v.30 no.2
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• pp.114-118
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• 2018

A single specimen (1,058 mm TL) of Pteroplatytrygon violacea, belonging to the family Dasyatidae, was firstly collected by using drift gill net in the north-western coastal waters of Jejudo Island, Korea on 6 July, 2017. This species was characterized by having a broadly rounded snout, five pairs of gill openings, tail with a large spine, ventral tail fold not reaching to the tip of tail, no dorsal fold, and ventral surface of disc dark purple. Based on such morphological characters, the specimen was identified as P. violacea and confirmed with the nucleotide sequence of the mitochondrial cytochrome c oxidase subunit I gene. We added P. violacea to the Korean fish fauna and propose the new Korean names, "Bo-ra-saek-ga-o-ri-sok" and "Bo-ra-saek-ga-o-ri" for the genus and species, respectively.

• ALGAE
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• v.35 no.3
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• pp.213-224
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• 2020

The freshwater red algal genus Sheathia contains species with heterocortication (both bulbous and cylindrical cells covering the main axis) and homocortication (only cylindrical cells). When the genus was proposed, the species with heterocortication were revised, but all specimens with homocortication were assigned to Sheathia arcuata with the caveat that it may represent a species complex. Recent studies have described new species with homocortication and S. arcuata has been rendered paraphyletic. In the current study, new sequences of the rbcL and 5′ region of the cytochrome c oxidase subunit I markers were combined with previously published data to construct a robust phylogeny and circumscribe new species. Four new species, S. abscondita, S. californica, S. plantuloides, and S. transpacifica are proposed. Examination of morphological characters among homocorticate species show no diagnostic characters to distinguish among species, whereas S. plantuloides is only known from sporophytes (chantransia) so it lacks the typical morphological characters derived from the gametophytes for comparison. Although DNA sequence data would be needed to make a positive species identification, geography could be employed to narrow the identification to one or two species. The genus is geographically widespread having been recorded from oceanic islands and five continents, whereas the individual species typically occur on a single continent. With this study, the number of species recognized in Sheathia is raised to 17; seven heterocorticate and 10 homocorticate, making this genus one of the most species rich in the Batrachospermales. As well, the resulting phylogeny provides insights into the evolution of heterocortication in Sheathia.

• ALGAE
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• v.35 no.4
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• pp.337-347
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• 2020

Haraldiophyllum hawaiiense sp. nov. is described as a new mesophotic alga and a new genus record for the Hawaiian Islands. Six specimens were collected at a depth range of 81-93 m from Papahānaumokuākea Marine National Monument, and their morphology investigated, as well as molecular phylogenetic analyses of the plastidial ribulose-1,5-bisphosphate carboxylase-oxygenase large-subunit (rbcL) gene and a concatenated alignment of rbcL and nuclear large-subunit rRNA gene (LSU) sequences. Phylogenetic analyses supported H. hawaiiense sp. nov. as a distinct lineage within the genus Haraldiophyllum, and sister to a large clade containing the type species, H. bonnemaisonii, as well as H. crispatum and an undescribed European specimen. The six Hawaiian specimens were shown to be identical, but unique among other species of the genus as well as the recently segregated genus Neoharaldiophyllum, which comprises half of the species previously included in Haraldiophyllum. The vegetative morphology of H. hawaiiense sp. nov. resembles Neoharaldiophyllum udoense (formerly H. udoensis); however, no female or post-fertilization structures were found in the Hawaiian specimens to allow a more comprehensive comparison. The molecular phylogenies demonstrate that Haraldiophyllum is paraphyletic, suggesting either that the Myriogrammeae tribe includes undescribed genera, including Haraldiophyllum sensu stricto, or that Neoharaldiophyllum species should be transferred into the genus Haraldiophyllum. However, based on vegetative morphology and molecular analyses, and pending resolution of this taxonomic issue, the Hawaiian specimens are placed within the genus Haraldiophyllum. This new record for the Hawaiian Islands highlights the novel biodiversity from mesophotic depths, reaffirming the need for further investigation into the biodiversity of Mesophotic Coral Ecosystems.

• Korean Journal of Ichthyology
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• v.34 no.4
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• pp.225-230
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• 2022

The single postlarval specimen (7.53 mm in standard length) of Thalassoma quinquevittatum (Lay & Bennett, 1839), belongs to the family Labridae, was collected by a bongo net from the southern coastal waters of Jeju-do Island, Korea in November 2020. T. quinquevittatum has a deeply curved dorsal contour before the dorsal fin, the oval eyes, and no melanophores throughout the body. While T. amblycephalum has a slightly curved dorsal contour before the center of the dorsal fin, the circular eyes, and few melanophores on the body. A molecular analysis based on 548 base pairs sequences in the mitochondrial DNA cytochrome c oxidase subunit I region shows that the specimen was closely matched to adult T. quinquevittatum (K2P distance=0.002-0.005). We report the first record of T. quinquevittatum in Korean waters, and suggest its new Korean name "Da-seot-jul-saek-dong-nol-rae-gi".

• Journal of Life Science
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• v.20 no.3
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• pp.336-344
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• 2010

To assess population structure and genetic diversity among the Pacific cod (Gadus macrocephalus), we investigated mtDNA COI gene sequences of 7 populations. Samples were obtained from Sokcho, Wolsung, Geojedo, Yeosu, Geomundo and Westsouth in 2008 and 2009 (n=28). The sequence analysis of 28 individual samples showed 8 haplotypes, ranging in sequence divergence by pairwise comparisons from 0.2 to 2.2% (1 bp-11 bp). The Gal haplotype was found in Wolsung, Geojedo, Yeosu, Geomundo and Westsouth, and was regarded as the main haplotype of Korean Pacific cod. Ga2, Ga3, Ga6 and Ga7 haplotypes were found only in Sokcho. In the PHYLIP analysis, 8 haplotypes formed two independent groups: cladeA consisted of Ga2, Ga3, Ga6 and Ga7 haplotypes, whereas cladeB contained Gal, Ga4, Ga5 and Ga8 haplotypes. The genetic relationship between the two groups was weakly supported by bootstrap analysis(<50%). In pairwise comparisons between 6 populations other than that from Sokcho, a very high per generation migration ratio ($N_m$=infinite) and a very low level of geographic distance ($F_{sr}=-0.0123-(-0.0423)$) were observed. The estimates of genetic distance between Sokcho and the other localities were all statistically significant (p<0.05, p<0.01, p<0.001), indicating a limited mtDNA-based gene flow between Sokcho and other regions. The finding of the lowest genetic diversity in the Sokcho population (nucleotide diversity=0.00589) may be a result of relatively small population size and interrupted gene flow to other localities. Consequently, the overall considerable migration of Pacific cod population in Korea caused a genetically homogeneous structure to form, although a distinct population was found in this study.