• Journal of Species Research
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• v.6 no.spc
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• pp.185-214
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• 2017

The genus Phyllopodopsyllus T. Scott, 1906 is nearly cosmopolitan and contains around 60 valid species, but has not been previously recorded in Korea. One of the reasons is probably the paucity of research in marginal habitats, such as marine interstitial. I describe two new species here. Numerous specimens of both sexes of P. kitazimai sp. nov. were collected from a beach near Yeongdeok, while only two females of P. busanensis sp. nov. were collected from a beach near Busan. The new species differ in numerous macro-morphological characters, such as the segmentation and armature of the antennula, armature of the mandibula, maxillula, maxilliped, and the first three swimming legs, as well as the shape of the caudal rami and the female genital field. However, they show very little difference in the number and position of cuticular organs (pores and sensilla) on all somites, which might prove these rarely used micro-characters to be useful in the reconstruction of phylogenetic relationships in this group of harpacticoids. Both species have their closest relatives in Japan. Phyllopodopsyllus kitazimai is morphologically most similar to P. punctatus Kitazima, 1981, but can be distinguished by much longer third exopodal segments of the third and fourth swimming legs. Phyllopodopsyllus busanensis shares the largest number of morphological similarities with P. setouchiensis Kitazima, 1981, but can be distinguished by shorter caudal rami. A key to species is also provided.

• Animal Systematics, Evolution and Diversity
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• no.nspc5
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• pp.61-70
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• 2005

A new marine interstitial nematode species belonging to the subgenus Quadricoma of order Desmoscolecida is described from Jindo Island, South Korea. The new species, Tricoma (Quadricoma) jindoensis sp. nov., is most allied with T. (Q.) crassicomoides Timm, 1970 in sharing the similar cephalic setae, broadly truncated border of head, lip region including 6 labial papillae, and slender and long spicule among the seven congeners with 44 quadricomoid rings. However, T. (Q.) jindoensis differs from it by the globular protuberance on the penultimate ring, 7 tail rings, and 9 pairs of subdorsal setae in male. This is the first record of Quadricoma nematodes from East Asia.

• Korean Journal of Ichthyology
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• v.6 no.2
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• pp.193-205
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• 1994

In order to understand fine structural and histochemical changes in the cyst cell and he interstitial cell in the testis of the spottybelly greenling Hexagrammos agrammus associated with the reproductive cycle from January to December, 1992, there cells were studied by electron microscopy and light microscopy. The cyst cells in the mature testis show a weak affinity to haematoxylin. while they become larger in size. At this time, these cells appear to be more functional than those on the growing stage because several mitochondria, endoplasmic reticulum, glycogen particles and a few lipid droplets appear in the cytoplasm of the cyst cell. It appears, therefore, that the cyst cell of this species has vital functions for nutrition, secretion and steroidogenesis. Well-developed interstitial cells contain large rod-shape or spherical mitochondria with tubular cristae and the large quantities of smooth endoplasmic recticulum and electron-dense materials in the vesicle at the mature and spawning stage. The interstitial cells of this species show characteristics of steroid interstitial cells having a vesicular nucleus, mitochondria with tubular cristae, and smooth endoplasmic reticulum. However, these interstitial cells of teleost give negative histochemical reactions for Sudan black B.

• Journal of Species Research
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• v.8 no.3
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• pp.268-282
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• 2019

Recent integrative taxonomic research demonstrated a high endemism of Korean copepods, with closest relatives usually in neighboring countries. Although Korean fauna could be considered well-studied, some marginal habitats still provide unexpected discoveries of copepods described from distant parts of the world. Here I report three such examples. Two belong to the family Tetragonicipitidae: Phyllopodopsyllus thiebaudi santacruzensis Mielke, 1989 and Laophontella horrida dentata Mielke, 1992; one to the family Ancorabolidae: Laophontodes norvegicus George, 2018. Scanning electron microscope photographs are provided for the first time for all three species, revealing unknown details of complex three-dimensional structures and ornamentation of somites. Phyllopodopsyllus thiebaudi santacruzensis was described from the Galapagos Islands, while Laophontella horrida dentata was described from the Pacific Coast of Costa Rica; for both this is the second record, which extends their range into the Western Pacific. Laophontodes norvegicus was described from Norway; this Korean record is its first in the Pacific. The first species is represented in my samples by numerous males, females, and juveniles. However, the second one is represented by one adult male and one juvenile female, while the third is represented by a single adult male, which might suggest that the marine interstitial is not their preferred habitat in Korea.

• Animal Systematics, Evolution and Diversity
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• v.35 no.1
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• pp.33-36
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• 2019

The marine interstitial annelid Pharyngocirrus uchidai(Sasaki, 1981) has been only known from Japan. In this study, we report the occurrence of P. uchidai for the first time in four localities along the eastern coast of Korea: Bukmyeon, Gamchu, Gase, and Oeongchi. Species identification was confirmed by comparison of DNA barcoding sequences with morphological examination from the type locality, Oshoro, Japan. We generated a total of 25 sequences of a partial segment (580 bp) of the cytochrome c oxidase subunit I gene (COI), representing five specimens from each locality. Maximum intra-specific variation was 1.2% in terms of Kimura two-parameter (K2P) distance, observed between two individuals each from Gamchu (i.e., between two specimens from the single locality), Gamchu and Oeongchi, Gamchu and Oshoro, and Oeongchi and Oshoro. On the other hand, an identical haplotype was found in all the five localities, substantiating our species identification for the Korean populations. Inter-specific K2P distance between P. uchidai and an unidentified Saccocirrus sp. from Canada (based on public database entries) was 22.4-23.4%.

• Journal of Advanced Marine Engineering and Technology
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• v.19 no.1
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• pp.36-44
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• 1995

Melting characteristics of unrestrained liquid ice in a rectangular vessel with heated top wall were investigated experimentally. The liquid ice, a mixture of ice particles and ethylene-glycol aqueous solution, was adopted as a testing material. During the melting process the liquid ice was drawn by buoyancy to the heated top wall of the rectangular vessel where close-contact melting occured. The melting behavior and melting rate of the liquid ice as well as local/mean heat-transfer coefficient at the heated top wall were observed and measured under a variety of conditions of heat flux and various initial concentration of the aqueous binary solution. It was found that the heat transfer of the heated top wall is remarkably promoted by the close-contact melting, and that the dendritic frozen layer at the lower interface of the liquid ice is formed. Photographic evidence demonstrated that plumes containing solute-rich liquid issued from isolated chimneys within the liquid ice layer where segregation of interstitial channel took place.

• Animal cells and systems
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• v.15 no.1
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• pp.63-72
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• 2011

A new species belonging to the genus Cyclopinoides Lindberg, 1953 (Cyclopinidae) is described from three beaches in Korea and Japan, as the first record of the genus from the Pacific. Among five species currently recognized in the genus, the new species resembles C. schulzi Herbst, 1964 from the Red Sea in sharing the character combination of 20-segmented antennule and stumpy caudal rami. However, C. orientalis n. sp. differs from it by relatively longer caudal rami (2.5-2.8 times as long as wide in female and about 1.6-1.8 times in male, while less than 2 times in female and about 1.3 times in male of C. schulzi), and by the transformation of an outer distal spine to a slender seta on the distal exopodal segment of leg 4. Moreover, C. orientalis n. sp. is discernible from C. schulzi in having a pyriform copulatory tube (against elongated tubular style in C. schulzi). A key to the species hitherto known in the genus is provided.

• Animal Systematics, Evolution and Diversity
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• v.35 no.3
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• pp.114-122
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• 2019

A new species belonging to the genus Cyclopinopsis Smirnov, 1935 (Cyclopinidae) is described from Korea, as the third species of the genus. Specimens were collected by washing the subtidal sediments off Dokdo Island in the East Sea and the intertidal sands at Baegripo beach, Taean Peninsula on the Yellow Sea coast. Cyclopinopsis deformata n. sp. is characteristic and distinguished from its two congeneric species currently recognized, C. curticauda Smirnov, 1935 and C. brasiliensis Herbst, 1955 in having a deformed seta at the outer distal corner of the third exopodal segment of leg 4. The seta is supposed to be deformed from an outer spine on the third exopodal segment of leg 4, which has been known as completely lost in the genus until now. A character comparison table of the three species and a key to species of the genus Cyclopinopsis are provided herein.

• Journal of Species Research
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• v.5 no.3
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• pp.289-299
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• 2016

Extensive survey of invertebrates in Korea, led by the National Institute of Biological Resources in Incheon, continues to uncover many new and endemic species, but also elements of neighbouring faunas that were previously unknown here. Hemicyclops tanakai Itoh and Nishida, 2002 was originally described from estuarine mud-flats in Tokyo Bay, Japan. We report one male and two females from a sandy beach on Jeju Island, which represent its first record in Korea and second record ever. No morphological differences were observed between these two disjunct populations, so we expect more records of this species in Korea and Japan. Tisbe ensifer Fischer, 1860 was originally described from Madeira and later on reported from numerous other parts of the Northern Atlantic, as well as from the Indian Ocean. We report two females from a shallow littoral in Sokcho, which represents its first record in Korea and the first record in the entire Pacific Ocean. Because of morphological discrepancies reported in previous records we recognize that this species might be in reality a species complex, and we only tentatively identify our Korean specimens as T. cf. ensifer. We provide numerous light photographs of both species in addition to short descriptions, in hope that they might elucidate global problems of their zoogeography and dispersal of small marine invertebrates in general. Further samplings from Korea and other parts of the world will be necessary to test our identifications and phylogenetic relationships of Korean populations with molecular and other tools.

• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.311-318
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• 2006

Ultrastructure of germ cells, the cyst epithelial cells and interstitial cells during spermatogenesis of the stone flounder, Kareius bicoloratus (Pleuronectidae) sampled on the west coast of Korea were investigated by electron microscopic observations. In the primary spermatocyte, the synaptonemal complexes appear in the zygotene stage of the prophase during maturation division. In the growing testis, especially, the interstitial cells (Leydig cells) appear near the primary, secondary spermatocytes and spermatids. Well-developed interstitial cells (steroid hormone secreting cells) which are located in the interlobular space in growing testis have three morphological characteristics of a vesicular nucleus, mitochondria with tubular cristae and smooth endoplasmic reticulum. During spermatogenesis, the primary and secondary spermatocytes attach to the cyst epithelial cell (Sertoli cell) having an elongated ovoid or triangular nucleus and several mitochondria in the cytoplasm. In the growing testis, lipid droplets, the mitochondrial rosettes and glycogen particles appear in the cytoplasm of the cyst epithelial cells near the secondary spermatocytes and spermatids. Particularly, the mitochondria, endoplasmic reticulum, little lipid droplets and the large amount of glycogen particles are present in the cytoplasm of the cyst epithelial cell in the late growing testis. In the late stage of spermiogenesis, the proximal centriole is joined to the nuclear envelope, the distal centriole forms the basal body of the flagellum and gives rise to the axial filament of the flagellum. No acrosome of the sperm is formed as seen in other teleost fish. The head of the spermatozoon is approximately $3{\mu}m$ in length and its tail is about $30{\mu}m$ in length. The axoneme of the tail flagellum of the spermatozoon consists of nine outer doublet microtubules at the periphery and two centrial singlet microtubules at the center. The spermatozoon of this species has two axonemal lateral fins. Especially, the cyst epithelial cells which located near groups of gametes in the various stages, show three functions: nutrition, phagocytosis and steroidogenesis. Especially, the nuclei of cyst epithelial cells in the recovery stage of the testicular developmental stages appear to be irregular in shape after spermiation. Of three functions of the cyst epithelial cell, several characteristics of phagocytosis are showed in the cytoplasm of the cyst epithelial cells in the recovery stage of the testicular developmental stages. At this stage, therefore, it is assumed that the cyst epithelial cells are involved in degeneration and resorption of undischarged germ cells after spermiation.