• Title/Summary/Keyword: marine bio

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Feeding Habits of Javelin Goby Synechogobius hasta on Tide Flat in Sangnae-ri Suncheon, Korea (순천 상내리 갯벌역에 출현하는 풀망둑(Synechogobius hasta)의 식성)

  • Park, Jong Hyeok;Jeong, Jae Mook;Kim, Hyeon Ji;Ye, Sang Jin;Baeck, Gun Wook
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.6
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    • pp.982-987
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    • 2015
  • During the study period, a total of 158 individuals of Synechogobius hasta were collected. The range of body length (BL) was 15.4-44.5 cm. The stomachs of 26.6% of the individuals were empty. The most abundant prey was shrimp. Among shrimp, Exopalaemon orientis was the most abundant species, being present in 27% in %IRI (index of relative importance). Fishes and crabs were also abundant prey. Analysis of ontogenetic changes, suggested that shrimp were the main prey of S. hasta of two size classes (<20 and 20-25 cm). The proportion of shrimp decreased, but that of fishes and crabs increased, with increasing body length, beginning at the 25-30 cm size class. In spring, fishes were the dominant prey, while shrimps, and crabs and fishes dominated in autumn and winter, respectively.

Gene Structure and Estrogen-Responsive mRNA Expression of a Novel Choriogenin H Isoform from a Marine Medaka Oryzias dancena

  • Lee, Sang Yoon;Kim, Dong Soo;Nam, Yoon Kwon
    • Fisheries and Aquatic Sciences
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    • v.15 no.3
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    • pp.221-231
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    • 2012
  • The marine medaka Oryzias dancena choriogenin H gene (odChgH) and its mRNA expression during estradiol-$17{\beta}$ (E2) exposure were characterized. At the amino acid level, the choriogenin H protein is predicted to possess the conserved repetitive N-terminal region, as well as zona pellucida (ZP) and Trefoil factor family (TFF) domains. At the genomic level, odChgH has an eight-exon organization with a distribution pattern of transcription factor binding sites in the 5'-upstream region, which is commonly found in other estrogen-responsive genes. The tissue distribution pattern of odChgH mRNA was found to be gender-specific, whereby females showed a higher expression level and wider tissue distribution than did males. During embryonic development, odChgH mRNA was robustly detected from the stage of visceral blood vessel formation. Experimental E2 exposure of males resulted in odChgH mRNA being induced not only in the liver, but also in other several tissues. The E2-mediated induction was fairly dose-dependent. The basal expression levels of hepatic odChgH mRNA were lower in males that were acclimated to 30 ppt salinity than in those acclimated to 0 or 15 ppt salinity. In contrast, the inducibility of odChgH mRNA during E2 exposure was greater in seawater-acclimated fish than in brackish water- or freshwater-acclimated fish.

Maturation and spawning of female black scraper, Thamnaconus modestus in the coastal waters off Middle East Sea, Korea (동해 중부해역에 출현하는 말쥐치(Thamnaconus modestus) 암컷의 성숙과 산란)

  • NAM, Ki-Mun;YOO, Jun-Taek;KIM, Jea-Won;PARK, Jong Hyeok;BAECK, Gun Wook
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.54 no.1
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    • pp.89-95
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    • 2018
  • The maturation and spawning of black scraper, Thamnaconus modestus were studied using samples collected monthly from March, 2015 to February, 2016 in the coastal waters off Middle East Sea, Korea. The gonadosomatic index (GSI) of female was the highest in June. The spawning periods lasted from March to September based on histological observation of female gonad development. The percentage of sexually mature females estimated from a logistic function was over 50% for the size group 18.02 cm (total length, TL). The size of eggs spawned was between 0.40 to 0.58 mm. Fecundity varied between 185,648 and 9,747,250 eggs. The relationship between the fecundity and TL of the fish was expressed in the fecundity equation as $F=0.0297TL^{5.4835}$.

Diet of the Walleye Pollock Gadus chalcogrammus in the East Sea, Korea (한국 동해에 출현하는 명태(Gadus chalcogrammus)의 위내용물 조성)

  • Ko, A Reum;Lee, Soo Jeong;Yang, Jae Hyeong;Baeck, Gun Wook
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.53 no.3
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    • pp.456-463
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    • 2020
  • The diet of the walleye pollock Gadus chalcogrammus, was studied by examining the stomach contents of 864 individuals. Using gill nets, samples were collected monthly from January to December 2017 in Jugwang, Sokcho, Yangyang, Uljin, Ganggu, and Gampo, Korea. The specimens ranged in total length (TL) from 16.6 to 75.2 cm. G. chalcogrammus fed mainly on Euphausia pacifica (Euphausiacea) and less on Cephalopoda, Pisces, Mysidacea, and Macrura. The results indicated that G. chalcogrammus is a specialist feeder, feeding mainly Euphausiacea. With growth, however, its diet shifted from Euphausiacea to Cephalopoda, Macrura and Pisces. Smaller individuals (<40.0 cm TL) consumed mainly Euphausiacea. The proportion of Euphausiacea decreased with increasing body size, whereas the consumption of Cephalopoda and Macrura increased gradually.

A Study on the Human Resources Development with the IT Combined Ability in the Field of Fisheries and Oceans in Busan (부산지역 해양수산 IT융합 인적자원개발에 관한 연구)

  • Jang, Young-Soo;Park, Jong-Un;Song, Jung-Hun;Choi, Sung-Wook
    • Journal of Fisheries and Marine Sciences Education
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    • v.23 no.2
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    • pp.244-252
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    • 2011
  • This study was carried out through survey based on job candidates of marine-bio, marine logistics, and GIS in order to train the human resources with the IT combined ability in the field of fisheries and oceans in Busan. Also, it included the survey on the field of the human resource development which businesses require in Busan. The analysis showed that food industry was most preferred by job candidates and the most required efforts for self-development to employ was to improve their English skills. The most preferred area was Busan and their salary requirements were in the 25 million to 30 million Won range. In findings on survey of businesses, businesses showed a profound interest in HACCP qualification in sea food and logitics manager qualification, and thought that the abilities that job candidates must have were communication and creativity rather than major and skills.

Seasonal Variation in Species Composition of Fishes Collected by a Three Sided Fyke Net from Sannam Reservoir in Changwon-si, Gyeongsangnam-do (경상남도 창원시 산남저수지에서 삼각망으로 채집된 어류의 계절별 종조성)

  • Kim, Kyung Ryul;Park, Jong Hyeok;Park, Jong Sick;Choi, Mun Seong;Lee, Dae Hyun;Baeck, Gun Wook
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.52 no.6
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    • pp.745-751
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    • 2019
  • Seasonal variation in species composition of fishes in the Sannam reservoir in Changwon, Korea was determined using samples collected by a three-sided fyke net in 2018. During the study period, we collected 2,181 individuals of 9 species, with a total weight of 111,552.2 g. The dominant species were Lepomis macrochirus, Carassius carassius, Erythroculter erythropterus, and Cyprinus carpio. These species accounted for 96.1% of the total number of individuals. The number of fish species, number of individuals, biomass and species diversity indices fluctuated with the seasons. The peak number of fish species occurred in May and August, the biomass of fishes was highest in May. Whereas the number of individuals was highest in February.

Apoptotic effect of physcion isolated from marine fungus Microsporum sp. in PC3 human prostate cancer cells

  • Ding, Yi-Shan;Kim, Won-Suk;Park, Sun Joo;Kim, Se-Kwon
    • Fisheries and Aquatic Sciences
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    • v.21 no.8
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    • pp.22.1-22.7
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    • 2018
  • Background: Apoptosis is a process of programmed cell death, and apoptosis defect results in serious diseases such as cancer. Apoptosis induction is one of the key mechanisms of anti-cancer agents. This study was aimed to find anti-prostate cancer compounds from marine-derived fungus Microsporum sp. Results: We found that physcion isolated from the fermentation broth extract of the marine fungus Microsporum sp. strain MFS-YL decreases the cell proliferation of PC3 human prostate cancer cells. Physcion induced cell apoptosis as determined by Annexin V/propidium iodide double staining. Physcion downregulated the anti-apopotoic proteins such as Ras, Bcl-xL, and Bcl-2, whereas upregulated the pro-apoptotic Bax. Physcion also activated caspase-3, caspase-8, and caspase-9. Conclusion: These results suggest that physcion from Microsporum sp. inhibits the proliferation of PC3 human prostate cancer cells via the pathway leading to apoptotic cell death. Physcion may be a potential candidate in the field of anticancer drug discovery against human prostate cancer.

Feeding habits of the bighead croaker, Collichthys niveatus in West Sea, Korea (서해에서 어획된 눈강달이(Collichthys niveatus)의 식성)

  • KO, A-Reum;JEONG, Jae Mook;BAECK, Gun Wook
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.4
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    • pp.327-334
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    • 2019
  • The feeding habits of the bighead croaker Collichthys niveatus were studied using 745 specimens collected by bottom trawl net in the West Sea, Korea, in April and October of 2016, 2017 and 2018. The size of C. niveatus ranged from 4.8 to 16.0 cm in total length. The stomach contents analysis indicated that C. niveatus consumed mainly euphausiids and copepods. C. niveatus consumed mainly euphausiids and copepods in all size classes. The dietary compositions of C. niveatus was not significantly different among size classes (One-way ANOVA, P > 0.05). As body size of C. niveatus increased, the mean weight of prey per stomach (mW/ST) tended to increase.