• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.4
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• pp.322-328
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• 2009

Three-hundred and sixteen Escherichia coli strains from seawater, and a variety of farmed fishes, including oliver flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagrus major) and sea bass (Lateolabrax japonicus) between May to October in 2004, were tested by agar dilution method to determine their susceptibility patterns to 17 antimicrobial agents. Overall, 92.1% of Escherichia coli isolates from samples showed antimicrobial resistance to at least one antimicrobial agent and the multiple resistance was seen in 173 isolates (54.7%). The resistance of E. coli isolates to tetracycline (74.1%) was highest, followed by cephalothin (69.9%), doxycycline (66.5%), streptomycin (47.2%), ampicillin (46.2%), cefazolin (31.6%), enrofloxacin (31.0%). norfloxacin (28.2%). The most frequent resistance pattern was TE-D-CF-CIP-ENO-NOR-AM-S-C-SXT-AmC-CZ (14.7%), followed by CF (6.2%), TE (5.1%), TE-CF (4.5%) in 177 isolates from fishes and TE-D-CF (7.2%) followed by TE-D-CF-S (5.8%), CF and TE-D-S (3.6%) in 139 isolates from seawater.

• Journal of Life Science
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• v.21 no.8
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• pp.1149-1155
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• 2011

Myostatin (MSTN) belongs to the transforming growth factor-${\beta}$ superfamily or growth and differentiation factor 8 (GDF-8), and functions as a negative regulator of skeletal muscle development and growth. Previous studies in mammals have suggested that myostatin knock-out increased muscle mass and decreased fat content compared to those of the wide type. Recently, several studies on myostatin have beenconducted on the block myostatin signal pathway with myostatin antagonists and the MSTN regulation with RNAi to control myostatin function. This study was performed to analyze growth and muscle alteration of Oncorhychus masou by treatment with recombinant myostatin prodomains derived from fish. We designed myostatin prodomains derived from P. olivaceus (pMALc2x-poMSTNpro) and S. schlegeli (pMALc2x-sMSTNpro) in a pMALc2x expression vector, and then purified the recombinant proteins using affinity chromatography. The purified recombinant proteins were treated in O. masou through an immersion method. Recombinant protein treated groups did not show a significant difference in weight, protein, or lipid composition compared to the control. However, there was a difference in the average number and area for histological analyses in the muscle fiber. At twelve and twenty-two weeks from the initial treatment, there were differences in averagefiber number and area between the 0.05 mg/l treated-group and the control, but the numbers were similar to those of the control during the same time period. At twelve weeks, however, 0.2 mg/l treated-group had an increase in average fiber number and decrease in average fiber area compared to the control. At twenty-two weeks, the pMALc2x-sMSTNpro 0.2 mg/l treated-group was induced and showed a decrease in average fiber number and increase in average fiber area. The results between twelve and twenty-two weeks showed that the fiber numbers had decreased, whereas average fiberarea had increased due to sMSTNpro. It is understood that the sMSTNpro induced only hyperplasia at twelve weeks, after which it induced hypertrophy. Recombinant myostatin prodomains derived from fish may induce hyperplasia and hypertrophy in O. masou depending upon the time that has elapsed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.6
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• pp.365-371
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• 2005

The antimicrobial resistance patterns to the 10 antimicrobial agents of potential pathogenic vibrios isolated from seawater and a variety of farmed fishes, including oliver flounder (Payalichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagyus major) and sea bass (Lateolabyax japonicus), were investigated from May to October, 2004. A total of 314 strains of the genus vibrios were isolated from 126 collected samples, and the number of isolated strains of Vibrio payahaemolyticus and Vibrio alginolyticus were 194 and 120, respectively. Apparently $98.5\%$ of V. parahaemolyticus and $100\%$ of V. alginolyticus isolates demonstrated antimicrobial resistance against at least one antimicrobial agent. The resistance of V. parahaernolyticus isolates to ampicillin ($97.9\%$) was highest, followed by oxolinic acid ($26.8\%$), amikacin ($19.1\%$) and tetracycline and amoxicillin/clavulanic acid ($6.7\%$). V. alginolyticus isolates were resistant to ampicillin ($100\%$), solfamethoxazoleit,imethopenem ($25\%$), amikacln ($21.7\%$), amoxicillin/clavulanic acid ($15.8\%$), ciprofloxacin ($13.3\%$), and tetracycline and doxycycline ($11.7\%$). The rate of multiple antimicrobial resistance to at least four antimicrobials was higher in the V. alginolyticus isolates ($20.8\%$) than in the V. parahaemolyticus ($6.7\%$).

• Korean Journal of Ichthyology
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• v.21 no.3
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• pp.191-199
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• 2009

Fisheries resources collected by set net in the Mizo fishing ground off Namhae Island were studied from March to December 2004 to determine species composition and catch variation. The water temperature of the fishing ground ranged $10.9{\sim}25.1^{\circ}C$ A total of 69,147.5 kg comprising 39 species was caught during the survey period. Most of the catch was fishes (33 species); others included cephalopods (5 species) and crustaceans (1 species). The dominant species were migratory, such as Trichiurus lepturus, Ammodytes personatus, Engraulis japonicus, and Scomberomorus niphonius, and accounted for 81.2% of the total catch. Sub-dominant species were Sardinops melanostictus, Acanthopagrus schlegeli, shrimps, and Todarodes pacificus, but they accounted for only 12.1% of the total. The catch by set net during the fishing period was much higher in spring and in autumn than in summer, relating to the recruitment of dominant species. Although the number of species had a tendency to decreased after summer, the catch in autumn was also higher than that in spring due to high temperatures (>$17^{\circ}C$ and seasonal variation of dominant species. The dominant species in spring were A. personatus and E. japonicus and in autumn were T. lepturus, S. niphonius, and E. japonicus.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.2
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• pp.152-159
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• 2017

Rockfish was a commercially important fish specie in marine ranching areas in Korea. To estimate density and biomass of rockfish using acoustic method, target strength (TS) information is required on the species. This study measured TS dependence on tilt angle and size on 14 live rockfish individuals at 38, 70, and, 120 kHz by ex-situ measurement (tethered method) and acoustic scattering model (Krichhoff ray mode, KRM). The swimbladdered angle ranged from 18 to $30^{\circ}$ ($mean{\pm}s.d.=26{\pm}4^{\circ}$). The mean TS for all individuals was highest -35.9 dB of tilt angle $-17^{\circ}$ at 38 kHz, -35.4 dB of tilt angle $-25^{\circ}$ at 70 kHz, and -34.9 dB of tilt angle $-22^{\circ}$ at 120 kHz. The ex-situ TS-total length (TL, cm) relationships were $TS_{38kHz}=20log_{10}(TL)-67.1$, $TS_{70kHz}=20log_{10}(TL)-68.6$, and $TS_{120kHz}=20log_{10}(TL)-69.9$, respectively. The model TS-total length (TL, cm) relationships were $TS_{38kHz}=20log_{10}(TL)-66.4$, $TS_{70kHz}=20log_{10}(TL)-67.0$, $TS_{120kHz}=20log_{10}(TL)-67.0$. The two measurements between the ex-situ TS and KRM model for TS-tilt angle and fish size were found to be significantly correlated.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.6
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• pp.435-439
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• 2008

The antimicrobial resistance of 160 strains of Enterococcus faecalis and 173 strains of E. faecium to 12 antimicrobial agents was investigated. The test strains were isolated from 126 wild seawater and farmed fish, including olive flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagrus major), and sea bass (Lateolabrax japonicus), in 2005 and 2006. Overall, 91.9% of the E. faecalis isolates and 88.4% of the E. faecium isolates showed antimicrobial resistance to at least one antimicrobial agent. The pattern of antimicrobial resistance of the isolates differed little according to the species of fish. The percentage of E. faecalis and E. faecium with specific antimicrobial resistance differed according to the sample source. For the isolates from farmed fish samples, 66.7% of E. faecalis were tetracycline resistant and 54.5% of E. faecium were erythromycin resistant. By contrast, in the wild fish seawater samples, 92.0% of E. faecalis were rifampin resistant and 88.5% of E. faecium were tetracycline resistant.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.62-71
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• 1997

The apparent nutrient digestibilities were examined by using chromic oxide indicator according to the various fecal collection methods in juvenile and adult Korean rockfish (Sebastes schlegeli). Feces were collected from three replicate groups of fish by dissection, stripping or decantation using fecal collector attached to fish rearing tank, respectively. The digestibilities of dry matter, protein, lipid, and energy were affected by fecal collection methods (P<0.01), but not affected by fish size. The digestibilities of nutrient determined by stripping or decantation methods were significantly higher than those determined by dissection method (P<0.01). No significant differences in the digestibilities of protein, lipid and energy were found between the stripping and decantation methods in adult fish (P>0.01). The digestibilities of dry matter, protein, lipid, energy, nitrogen-free extract, and total amino acids in juvenile and adult fish were 58, 93, 94, 79, 32, and $93\%$, and 61, 94, 96, 80, 29, and $94\%$, respectively, when they were measured by decantation method. Methionine, cystine and valine digestibilities were significantly lower than those of other amino acids in both juvenile and adult fish (P<0.01). Results indicate that stripping or decantation with fecal collector could be a reliable digestibility procedure for measuring the nutrient digestibilities in Korean rockfish.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.1
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• pp.48-54
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• 2007

Bacillus polyfermenticus SCD (B. polyfermenticus SCD) has been appropriately used for the therapy of long-term intestinal disorders, because live strains in the form of active endospores can successfully reach the target intestine in humans. B. polyfermenticus SCD produces the most antibiotic-related materials. In the present study, B. polyfermenticus SCD was fermented with soybeans (BPFS) and its probiotic properties were investigated. B. polyfermenticus SCD and BPFS showed a broad spectrum of antimicrobial activity against pathogenic Gram-positive (Streptococcus parauberis, Streptococcus iniae, Lactococcus garviae) and Gram-negative (Flexibacter tractuosus, Vibrio harveyi, Vibrio vulnificus, Vibrio ordalii) bacteria and moulds (Aspergillus niger, Aspergillus oryzae). Sebastes schlegeli were used to examine survival rate and cleanup action by BPFS. Bacterial infection resulted in a mortality of up to 99% in the commercial fodder fed groups. BPFS both enhanced the growth rate of fry by improving their appetite and had cleaned by decreased eutrophication. Therefore, it seems appropriate that BPFS should be developed as an antibiotic replacement, favorable fodder additive, and antifungal material in fish farming systems.

• Environmental Analysis Health and Toxicology
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• v.21 no.2 s.53
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• pp.103-113
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• 2006

This study examined effects of crude oil on the phase II drug-metabolizing enzymes UDP-glucuronosyl transferase (UDPGT) and glutathione S-transferase (GST) in mussel Mytilus edulis and rockfish Sebastes schlegeli, a representative bivalve and a culture fish, respectively. This work also intended indirectly to evaluate the post impact recovery from the massive oil tanker spillage accidents occurred during the summer of 1995 in the sea area off Yosu City, Chonnam. For these, enzyme activities of UDPGT and GST were examined in the fish and mussel following laboratory exposure to fresh crude oil, weathered oil, field-obtained oil residues, or in the field biota samples. Decreased GST activity was observed in rock fish following exposure to oil-soluble fraction (OSF) of fresh oil. A similar diminished GST activity was also observed after OSF of artificially weathered oil. OSF of field oil residues retrieved from the spillage area approximately 1 year later also exerted a slight inhibition of GST to rockfish. There was neither a change in UDPGT in rockfish, nor were there changes in mussel in both enzymes to any oil fractions. We could not observe any difference in the two enzymes either in rockfish or mussel sampled from the field during $1.5{\sim}2.0$ years post spillage, indicating that their enzyme systems might had been recovered by the sampling time. In conclusion, it seems that the inhibition of GST activity in rockfish is a biomarker response to crude oil exposure. The results, however, must be interpreted with care, as the inhibition nay reflect various factors such as oil concentration, duration and water temperature.

• Korean Journal of Ichthyology
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• v.17 no.2
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• pp.142-147
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• 2005

To research changes in the fish community of intertidal zones in relation to the construction of the Saemangeum tidal embankment, fishes were collected in the tide pools of Naechodo, Gunsan-si, and of Haechang, Buan-gun in Jeollabuk-do, every month from December 2002 to October 2004. Based on the fishes collected and data from previous studies show that in the tide pools of Haechang, the number of species decreased, and the dominant species is Tridentiger trigonocephalus, as before. However, in the tide pools of Naechodo, the number of species decreased, and the dominant species changed from T. trigonocephalus to Synechogobius hasta. Favonigobius gymnauchen, which inhabits sand-beds, decreased remarkably. Meanwhile, in the intertidal zone of Haechang, young black porgy were caught in large quantities, while in the intertidal zone of Naechodo, young Acanthopagrus schlegelii and Lateolabrax japonicus, which had been caught in a large amounts between 1994 and 2000, were not caught. The results are thought to show that the intertidal zone of Naechodo, Gunsan-si, had more deposits by tide flats than that of Haechang, Buan-gun, which drastically changed the habitat of its fish community.