• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.575-584
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• 2021

The critical low temperature and response of the behavioral tolerance of red sea bream Pagrus major fingerlings were determined using the continuous behavior monitoring system (CBMS). The behavior of the experimental organisms was observed by decreasing the water temperature by 2.0℃ and 4.0℃ every 12 hours and 24 hours in the range of 8.0-20.0℃. An unstable behavior pattern was observed in red seabream fingerlings exposed to water temperatures below 12.0℃, in which the swimming activity decreased and repeatedly stopped, regardless of the exposure time and water temperature fluctuation. The swimming ability of the organisms exposed to 8.0-10.0℃ decreased sharply, and the behavior of staying at the bottom of the test tank was observed. Only 50 % of the organisms survived due to the low-temperature stress, and all individuals died within six hours after the cold shock. In addition, the behavior index (BI) decreased rapidly, and the amplitude change of the coefficient of variation (CV) was found to have a greater variation than the other water temperatures (p<0.05). Low-temperature stress of red sea bream is promoted at 12.0℃, and it is interpreted as the tolerance limit, which can induce a sublethal response of the organisms exposed to cold shock of 8.0-10.0℃.

• Korean Journal of Environmental Biology
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• v.21 no.1
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• pp.26-30
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• 2003

Cytochrome P450 (CYP) induction was determined in microsomes of three aquacultured fish species (Sebastes schlegeli, Paralichthys olivaceus and Pagrus major) and two wild fish species (Mugil cephalus and Stephanolepis cirrhifey) in vitro exposed to $\beta$-naphthoflavone (BNF). The microsomes of five fish were exposed to BNF (5 mM or 10 mM) in dimethylsulfoxide at $30^{\circ}C$ for 9 hr. The CYP contents in most fish increased according to exposure duration for 3 or 5 hour, and then decreased, while steady increase of CYP was observed in P. major for 9 hour. The induction of CYP contents in aquacultured fish species (207~422%) were higher than those in wild fish species (206~207%).

• Proceedings of the Korean Aquaculture Society Conference
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• 2005.05a
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• pp.44-45
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• 2005

• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.158-159
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• 2004

• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.126-127
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• 2004

• Proceedings of the Korean Society of Life Science Conference
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• 2000.09a
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• pp.53-53
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• 2000

• Development and Reproduction
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• v.4 no.1
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• pp.125-131
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• 2000

This study has used differential display-PCR, to amplify genes transcribed during the ovarian maturation induced by human chorionic gonadotropin (hCG). The cDNA expressed at the times of acquisition of oocyte maturational competence in red seabream (Pagrus major) following treatment with hCG was amplified and cloned. A full-length of cDNA for p. major was isolated using differential display-PCR and 5'RACE. This cDNA clone contained 2,662 nucleotides including the open reading frame that encoded 434 amino acids. Homology analyses, using the GenBank and EMBL general database searches, indicated that the nucleotides sequence of the cDNA does not have high homology with any other genes. This cDNA was judged to be a gene, which induction of maturational competence coincides with increase of mRNA related ovarian maturation. Consensus sequences which were consistent with protein kinase C phosphorylation sites and casein kinase II phosphorylation sites were identified. in vitro, the transcription level of mRNA related ovarian maturation increased between 9hr and 24hr following treatment of ovarian follicles with hCG. It was also increased after GtH-II (300 ng/ml) stimulation. Furthermore, in vivo, mRNA related ovarian maturation was rarely expressed prior to the acquisition of oocyte maturational competence, but was strongly expressed after the acquisition of oocyte maturational competence, suggesting that the hCG induction of maturational competence is brought about by the de novo synthesis of the mRNA related ovarian maturation in p. major.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.3
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• pp.373-381
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• 1995

Oxygen consumption of marine fishes according to different water temperatures, fish population densities and body weights was measured in the respiratory chamber for the following six species: the olive flounder Paralichthys olivaceus, the tiger puffer Takifugu rubripes, the rockfish Sebastes schlegeli, the sea bass Lateolabrax Japonicus, the red seabream Pagrus major and the black seabream Acanthopagrus schlegeli. Also the lethal concentration of dissolved oxygen in them was determined. Oxygen consumption in each fish species increased as the water temperature increased. The relationship between the oxygen consumption rate $(Oc,\;ml/kg{\cdot}\;hr)$ and the water temperature (T,$^{\circ}C$) for each species appeared as the following equations demonstrate; olive flounder: Oc=34.0515T-339.5987 $(r^2=0.9730)$, tiger puffer: Oc=34.4941T-479.8732 $(r^2=0.9483),$ rockfish: Oc=44.7970T-634.2627 $(r^2=0.9718),$ sea bass: Oc=26.1488T-318.0633 $(r^2=0.9316),$ red seabream: Oc=61.1020T-722.8926 $(r^2= 0.9805),$ black seabream: Oc=75.1460T-947.9370 $(r^2=0.9392).$ The of gen consumption of fish with different population densities decreased as the number of fish increased. As the body weight of the olive flounder increased, the mass-specific oxygen consumption decreased. The relationship between oxygen consumption and body weight (W; g) was expressed as Oc=2532.0268W-0.6565 $(r^2=0.9229)$. The levels of lethal dissolved oxygen in the olive flounder, rockfish, tiger puffer and red seabream were 0.66, 0.79, 0.75 and 1.36 m1/1, respectively.

• Journal of Aquaculture
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• v.13 no.1
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• pp.69-78
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• 2000

Bioactivity growth and survival rte of yolk sac larvae in cultured black seabream (Acanthopogrus schlegeli) red seabream (Pagrus major) and olive flounder (Paralichthys olivaceus) to 5 different concentration (0, 25, 50, 75 and 100%) of water soluble fraction (WSF) of Kuwait crude oil were studied. The 75% and 100% of WSF concentration influenced negatively on the length growth of larvae in each species so the growth rates of total length in the concentration of WSF were significantly lower than those of control. The high concentration (50%, 75%, and 100%) of WSF influenced negatively not only on the swimming frequency and speed but also on the morphological abnormality of larvae. Red seabream larvae showed the highest rate of abnormality by WSF among the tested fishes. The fish larvae exposed during pre-and post-hatch (egg and larval stages) and during post-hatch (larval stage only) to the WSF were significantly influenced on their survival rate. The larvae of red seabream were more sensitive to WSF than those of black seabream and olive flounder. The survival rates of larvae exposed to higher concentration (50%, 75%, and 100%) of WSF were significantly lower than those of the control but those of the 25% group were not.

• Journal of Aquaculture
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• v.8 no.1
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• pp.1-19
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• 1995

In red seabream, Pagrus major the female specific protein in the vitellogenic female serum was identified by Ouchterlony's immunodiffusion test and immunoelectrophoresis. The female specific serum protein might be vitellogenin based on the results of the immunological analysis for the male and vitellogenic female sera and crude egg extracts. Also, it was identified by the immunodiffusion test that the purified yolk protein from ovarian egg extracts has antigenic identities shared with the female specific serum protein. To study the relationship between the maturational stages of gonad and plasma levels of vitellogenin, these were measured from the late resting period (January) to the vitellogenic preiod (April) by the modified enzymeimmunoassay (EIA) using antiserum against yolk protein. The level of plasma vitellogenin began to increase in February (previtellogenesis stage) and continuously increased with the ovarian growth during the vitellogenesis period (March to April). The plasma vitellogenin levels were significantly different between the females and the males in February. Validation for the modified EIA system. was tested .The absorbance curve of serial dilutions of serum from the vitellogenic female was paralleled to the standard curve of yolk protein; $109\pm5.6\%$ recovery was achieved by the modified EIA. And the intraassay coefficients of variation were less than 10% within the concentration ranging from 31.3 ng/ml to 1,000 ng/ml. These findings suggest that the sex determination in adult red seabreams could be possible by using the modified EIA as early as in February.