• Applied Microscopy
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• v.26 no.3
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• pp.267-275
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• 1996

The internal ultrastructural changes of germ cells and external morphology of spermatozoon during the spermatogenesis in the rockfish, Sebastes inermis were studied using transmission and scanning electron microscope. The testis is seminiferous tubule type in internal structure. Seminiferous tubule consist of many cyst which contain numerous germ cells in same developmental stage. Spermatogonium contained a large nucleus with single nucleolus in interphase. Primary spermatocyte identified by the presence of synaptonemal complex in nucleus and the contained a number of mitochondria, endoplasmic reticula and Golgi bodies in cytoplasm. The nucleoplasm of secondary spermatocyte was more concentrated than that of the previous phase. Spermatids were more condensed in nucleus and cytoplasm, and show the long-spherical shape. In the cytoplasm of spermatid mitochondria located to lower portion of the nucleus and Golgi bodies located to upper portion, but proacrosomal granule is not appeared. The spermatozoon consist of the head and tail. No acrosome could be found in the head. The cytoplasmic collar of posterior part in sperm head contained mitochondria which surrounded axial filament. The well developed axonemal lateral fins were identified in sperm flagellum, and the axial filament of the flagellum consist of nine pairs of peripheral microtubules and one pair of central microtubules.

• Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.20.1-20.12
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• 2016

The osteological development in Sebastes koreanus is described and illustrated on the basis of 32 larvae [6.11-11.10 mm body length (BL)] and a single juvenile (18.60 mm BL) collected from the Yellow Sea. The first-ossified skeletal elements, which are related to feeding, swimming, and respiration, appear in larvae of 6.27 mm BL; these include the jaw bones, palatine, opercular, hyoid arch, and pectoral girdle. All skeletal elements are fully ossified in the juvenile observed in the study. Ossification of the neurocranium started in the frontal, pterotic, and parietal regions at 6.27 mm BL, and then in the parasphenoid and basioccipital regions at 8.17 mm BL. The vertebrae had started to ossify at ~7.17 mm BL, and their ossification was nearly complete at 11.10 mm BL. In the juvenile, although ossification of the pectoral girdle was fully complete, the fusion of the scapula and uppermost radial had not yet occurred. Thus, the scapula and uppermost radial fuse during or after the juvenile stage. The five hypurals in the caudal skeleton were also fused to form three hypural elements. The osteological results are discussed from a functional viewpoint and in terms of the comparative osteological development in related species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.1
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• pp.52-58
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• 2014

Morphological and genetic variation of two populations of Platichthys stellatus were investigated based on 30 individuals each, collected from Uljin (seedling release area) and Pohang (control) in Korea. Morphological analyses demonstrated that the two populations of P. stellatus were well distinguishable in body color of the blind side and fin shape. Mitochondrial DNA control region analysis indicated no significant differences between the two populations ($F_{ST}=-0.00849$, P>0.05). We also analyzed microsatellite DNA loci of the two populations using six markers. Observed heterozygosity ($H_O$) and expected heterozygosity ($H_E$) were 0.550 and 0.592, respectively, in P. stellatus from Uljin, but 0.700 and 0.737 in P. stellatus from Pohang. An index of differentiation in genetic structure revealed significant differences between the two populations ($F_{ST}=0.0208$, P<0.05). Our results suggest that the Uljin population may be comprised of released P. stellatus, whereas the Pohang population may be wild P. stellatus, highlighting the necessity of continuous monitoring of the two populations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.5
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• pp.654-658
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• 2014

We report the first identification of a spawning ground of the blackfin flounder Glyptocephlaus stelleri near the Wangdol-cho sea mountains, located in the southern East Sea. Eggs and larval fish of G. stelleri were collected during April and June, 2014, when an abundance of eggs was found in the southern area of Wangdol-cho. Our findings suggest that G. stelleri prefers to spawn in the vicinity of the off-shore sea mountains, where the temperature is between 10 and $12^{\circ}C$ and the water depth is 100 m, rather than inshore.

• Animal Systematics, Evolution and Diversity
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• v.13 no.1
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• pp.29-36
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• 1997

한국산 기름종개속 어류중 Cobitis taenia complex의 집단간 유전적 차이에 따른 종 분화 여부를 밝히고자 6개 집단을 대상으로 mitochondrial DNA(mtDNA)의 RFLP분석을 실 시하였다. C. taenia complex mtDNA를 10개의 6-base cutting 제한효소로 처리한 다음 그 절편 양상을 비교, 분석한 결과 6개 집단 공히 mtDNA 의 전체 genome 크기는 약 17.0$\pm$ 0.5Kbp였으며 공동절편수(F)에서 C. t. taenia 2개집단과 C. t. stria와 C. t. lutheri 4개 집단 간의 F값은 평균 0.263으로 차이가 있었으나, C. t. striata 와 C. t. lutheri 사이는 F=0.569로 가깝게 나타났다. 염기치환율 (p)에 있어 C. t. taenia는 C. t. striata 및 C. t. lutheri와 평균 p=0.082로 뚜렷한 종간차이를 보였으나, C. t. striata와 C. t. lutheri 집단들은 p=0.033으로 매우 가까운 유사성을 나타내었다. MtDNA 분석결과 C. taenia complex 중 C. t. taenia는 완전히 종분화가 이루어진 별종으로, C. t. striata와 C. t. lutherisms 아직 종수준의 분화가 이루어지지 않은 아종으로 분류함이 타당하다고 사료된다.

• Animal Systematics, Evolution and Diversity
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• v.13 no.1
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• pp.9-20
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• 1997

한국산 송사리 (Oryzias)속의 송사리 (O. latipes)와 대륙송사리(O. sinensis)의 집단 내 유전적 변이 및 종간 유연관계를 밝히고자 남한의 16개집단과 일본산 송사리(O. latipes) 1개 집단 등 총 17개 집단에 대한 isozyme 분석을 실시하였다. Isozyme 분석 결과 17개의 효소 및 비효소단백질에서 총 32개의 유전자를 검출한 결과, 전체 유전자중 Est-1과 Est-3 는 종 특유의 유전적 표식인자(genetic marker)였다. 송사리집단 중 진도집단의 유전적 변이 가 가장 낮았으며(Ho=0.011, He=0.043), 대륙송사리 서천집단의 유전적 변이가 가장 높았 다.(Ho=0.114, He=0.124). 한국산 송사리 11개 집단의 평균 유전적 변이 정도는 P=12.7%, Ho=0.029, He=0.042, 대륙송사리 5개 집단의 평균 유전적 변이정도는 P=26.3%, Ho=0.082, He=0.097로 각각 나타나 대륙송사리집단의 유전적 변이 정도가 송사리집단에 비해 약 2.5배 정도 높았고 일본산 송사리의 유전적 변이 정도는 P=15.6%, Ho=0.073, He=0.068로 나타났 다. 한국산 송사리와 일본산 송사리와의 유연관계는 S=0.761(D=0.243)로 나타나 유전적으로 뚜렷한 별개의 분류군으로 생각되며, 대륙송사리와 송사리간의 종간 유전적 근연치는 S=0.648(D=0.389)로 일반적인 척추동물의 종간 유전적 분화 수준을 나타냈다.

• Korean Journal of Ichthyology
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• v.11 no.2
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• pp.191-197
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• 1999

Stomach contents of hairtail, Trichiurus lepturus collected in the Nakdong River Estuary were examined quantitatively. T. lepturus was a carnivore which consumed mainly fishes, crustaceans (such as copepods, euphausiids and shrimps) and chaetognaths. Its diets included small quantities of small squids. T. lepturus showed ontogenetic progression of three feeding stages : an initial feeding stage was a planktivorous stage in which copepods were the major food item, followed by a mixed feeding stage in which euphausiids, mysids, shrimps, chaetognaths and fishes were the major food items, and finally a piscivorous stage in which fishes were the major food item. Especially anchovies were heavily selected by large T. lepturus.

• Korean Journal of Ichthyology
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• v.11 no.2
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• pp.172-176
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• 1999

Chromosome of cobitid fishes, Iksookimia yongdokensis collected from the 4 streams flowing to the eastsouthern coast of Korea was studied using chromosome of gill and kidney cells prepared by flame drying technique. The results obtained were as follows: the chromosome number was 100 composed of 44 meta-submetacentric and 56 subtelo-telocentric chromosomes, and the fundamental number (FN) was 144. It was remarked that Iksookimia yongdogensis was distinguishable from its congeners in the karyotype. The above evidences may suggest that Iksookimia yongdokensis was one of the tetraploid species of cobitid fishes.

• Korean Journal of Ichthyology
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• v.8 no.1
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• pp.22-48
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• 1996

The toxonomic revision of the suborder Labroidei was made based on the specimens collected from the coasts of Korean Peninsula from 1988 to 1996. The fishes of this suborder in Korea are composed 32 species belonging to 22 genera and five families of Pomacentridae, Cichlidae, Embiotocidae, Labridae, and Scaridae. And the keys to species, genera and families are provided with redescriptions and collection data. Among them the specimens of 21 species were collected and Ditrema viridis of family Embiotocidae was the first record from the coast of Wando-gun, Chollanam-do, Korea. Most species of the suborder Labroidei of Korea were mainly distributed in the coast of Cheju Island and South coast influenced by the warm Kuroshio Current.

• Korean Journal of Ichthyology
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• v.8 no.1
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• pp.1-8
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• 1996

Cobitis striata testes were paired, with elongate form and suspended on the dorsal body wall. The testicular structure of immature testes composed of many seminal lobules with regular arrangement, whereas mature testes anastomose neighbouring seminal lobules. The spermatozoa of C. striata were anacrosomal aquasperm type and have spherical nucleus. The mid piece of spermatozoa was $0.8{\mu}m$ in length and contained 5~8 ring-shaped mitochondria. The flagellum of the spermatozoa in the present species was uniflagellate consisting of a typical 9+2 axoneme without fins.