• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.561-568
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• 2009

We determined the contents of heavy metals in the muscle of wild and cultured fishes, collected from fish markets located in the eastern (Pohang), western (Gunsan), and southern (Tongyeong) coasts of Korea, from 2004 to 2005. As the results of monitoring the heavy metal contents in spring season, the wild fishes contained the range of Cd (0.01-0.08 mg/kg), Cr (ND-0.28 mg/kg), Cu (0.06-1.53 mg/kg), Hg (0.02-0.16 mg/kg), Mn (0.04-1.15 mg/kg), Ni (ND-0.09 mg/kg), Pb (0.03-0.41 mg/kg), and Zn (1.84-6.61 mg/kg). While for the cultured fishes, Cd (0.01-0.05 mg/kg), Cr (ND-0.17 mg/kg), Cu (0.05-0.61 mg/kg), Hg (0.02-0.13 mg/kg), Mn (0.03-0.17 mg/kg), Ni (ND-0.08 mg/kg), Pb (0.03-0.33 mg/kg), and Zn (2.06-6.20 mg/kg) were contained. In summer season, the contents of heavy metal in the muscle of the wild fishes were as follows: Cd (ND-0.11 mg/kg), Cr (0.01-0.37 mg/kg), Cu (0.21-1.31 mg/kg), Hg (0.01-0.11 mg/kg), Mn (ND-1.47 mg/kg), Ni (ND-0.26 mg/kg), Pb (0.06-0.48 mg/kg), and Zn (2.94-14.38 mg/kg). In comparison, the contents of heavy metal in the muscle of cultured fishes were Cd (ND-0.05 mg/kg), Cr (0.13-0.33 mg/kg), Cu (0.19-0.56 mg/kg), Hg (0.05-0.26 mg/kg), Mn (ND-0.14 mg/kg), Ni (ND-0.58 mg/kg), Pb (0.07-0.45 mg/kg), and Zn (2.43-7.53 mg/kg). Also the fall and the winter season, the heavy metal contents in the fishes showed almost similar with other season, however, Pb was lower and Zn was higher than both spring and summer season. The wild fishes contained the heavy metals a little more than the cultured fishes. We could not observe clear seasonal variation in the heavy metal contents of the fishes. The levels of Hg and Pb in all samples tested did not exceed the maximum permissible levels in the fishes set by the Korean Food & Drug Agency for safe human consumption.

• Journal of Aquaculture
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• v.17 no.3
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• pp.167-172
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• 2004

Chemoenzymatic method was used in this study to evaluate the quality of cultured red seabrim. Level of ATP related compounds, ATPase and Adenylate energy charge (AEC) well reflected changes in condition of fish. ATP level in the muscle of exercised cultured red seabream was decreased significantly during cultured period. In contrast, the level of ADP in the muscle was increased during the period. Level of ATP related compounds in the muscle of cultured red seabream without exercise didn't show significant difference compared to the exercised group. AEC value in muscle of cultured red seabream without exercise was 0.89$\pm$0.02, while AEC value of the exercised group was 0.88$\pm$0.04. ATP and AEC levels among different size of fish did not show any significant difference. AEC value in all sample was higher than 0.8, indicating that the condition of cultured fish was healthy. Activity of Mg2$^{＋}$ (＋Ca2$^{＋}$), Mg2$^{＋}$ (-Ca2$^{＋}$) and Ca2$^{＋}$-ATPase during culture period did not change significantly, regardless of exercise. Therefore, the AEC appears to have some validity as fish health indicator.

• Journal of fish pathology
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• v.1 no.2
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• pp.73-76
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• 1988

There prevailed lymphocystis disease with 1 to 2cm in size in the skin and pins of cultured Sebastes schlegeli in fish farms in Tongyoung-gun, Sanyang-myeon, Kon-ri from summer, 1987 to fall, 1988. Though there were some difference between each fish farm, this disease prevailed widely from immature fish to mature fish, less than 10cm to 30cm in body length with about 8 through 80% of infection rate. Sebastes schlegeli with the lymphocystis disease showed combined nipple-shaped mass by doubly, triply propagated lymphocystis. But the author considered that lymphocystis disease was not a direct cause of death of Sebastes schlegeli, the fish showed marked inflammation by seconary infection of pathogenic organisms.

• Korean Journal of Veterinary Service
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• v.20 no.1
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• pp.11-18
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• 1997

Characteristics, pathogenicity and control of the causative organisms isolated front diseased cultured flounder, Paralichthys olivaceus were studied. The causative organisms were identified as E tarda by biochemical and biophysical characteristics. Also, it strains were named as E tarda KBF-1 and E tarda KMF-1, and optimal pH of E tarda KBF-1 and E tarda KMF-1 were 8.0, and optimal concentration of NaCl. E tarda KBF-1 was 0% and E tarda KMF-1 was 1%. In the pathogenicity test, 0~10 of the flounders of artificially infected group(E tarda KBF-1) with $1.0{\times}10^7$ cfu/fish were died within 60 hrs, but 0~9 flounders infected group with 41.0{\times}10^6$ cfu/fish were died within 60 hrs. Also, 0~10 flounders infected group(E tarda KMF-1) with $1.0{\times}10^7$ cfu/fish were died within 36 hrs, while 0~7 flounders infected with $1.0{\times}10^6$ cfu/fish were died within 60 hrs. Drug sensitivity of E tarda KBF-1 strain was resistant to AM, CF and N, and intermediate to E, K and S, and sensitivity to C, G, SxT and FF. But E tarda KMF-1 strain was resistant to CF, E and V, and intermediate to AM, C, N and SxT, and sensitivity to GM and FF.

• Ocean and Polar Research
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• v.23 no.3
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• pp.285-290
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• 2001

The strength of juvenile black rockfish, Sebastes schlegeli, raised in different hatcheries for wild stock enhancement was evaluated in terms of resistance to an anesthetizing agent, tricaine methane-sulfonate (MS-222), and exposure to drying. The working dosage of MS-222 varied significantly with fish size and hatchery population. Smaller fish were less resistant to the chemical than larger ones. MS-222 effects also differed with fish growth history. The fish cultured in embanked populations showed stronger resistance, earlier recovery, and lower mortality, compared to those cultured in land-based tanks or collected from wild stocks. Similar results were seen in juveniles challenged to dry exposure. These results suggest that an embanked population of black rockfish is more resistant to anesthetic stress, expressed as anesthesia recovery and mortality, and that this population is healthier than others.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.725-730
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• 2015

We observed yellow catfish Pelteobagrus fulvidraco fingerlings cultured in land ponds in Korea swimming in a corkscrew spiral pattern while hanging head-up and tail-down at the water surface, before eventually dying. Externally, these fish displayed “hole in the head” disease, pale gills, and hemorrhages in the base of the pectoral and caudal fins; internally they had liver hemorrhages and kidney discoloration. The bacterium Edwardsiella ictaluri (YCK-01 and YCL-01) was identified in the kidneys and livers of diseased fish via phenotypic characteristics and PCR analysis using the ictaluri-specific primers IVS (an intervening sequence) and IRS (the inter-ribosomal spacer). Infectivity challenges by intraperitoneal and immersion routes showed that a representative bacterial strain (YCK) exhibited strong virulence to yellow catfish, with an LD₅₀ of 3.2×10⁴ CFU/fish and 2.5×10⁶ CFU/mL, respectively. This is the first report of E. ictaluri infection in yellow catfish from Korea.

• Journal of fish pathology
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• v.31 no.2
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• pp.87-92
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• 2018

A case of disease was occurred in tiger puffer, Takifugu rubripes, reared in circulated system (water temperature was about $20^{\circ}C$) on land in Korea. Diseased fish showed a unique external sign, the cloudy skin ulcer in various sizes. We investigated the cause of disease, and isolated one pure cultured bacterium, TP01. This had 99.7% homology with Vibrio atlanticus by sequence analysis of the 16S rRNA and rpoA genes. TP01 showed some differences with other reported V. atlanticus strains in the biochemical characteristics as like Voges-Proskauer test and gelatin hydrolysis.

• Journal of Aquaculture
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• v.7 no.2
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• pp.109-122
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• 1994

The cultured olive flounder larvae given nutrient enriched rotifer, Artemia nauplii and commertial micro diet were investigated the changes of lipid content, fatty acid composition and vitamin E content in whole body with growth stages in order to compare with those of the wild one. The results obtained are as follows. 1) Lipid and vitamin E contents of the cultured larvae were higher than those of the wild one. 2) Clear differences of fatty acid composition with growth stages, especially 18: 2n-6 and 22 : 6n-3, were recognized between the wild and cultured olive flounder larvae. 3) Changes of lipid content, fatty acid composition and vitamin E content were found to be affected by dietary composition given to fish. 4) The wild olive flounder larvae were found to obtain natural live foods containing of low lipid content and high concentration 22: 6n-3 based on the fatty acid composition of the fish.

• Journal of fish pathology
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• v.21 no.3
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• pp.247-257
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• 2008

To understand the activity of non-specific defence factors in cultured Sebastes, the antibacterial effect of the serum, skin mucus and homogenate of various organs from cultured oblong rockfish (Sebastes oblongus) and rockfish(Sebastes schlegeli) against pathogenic bacteria, Aeromonas hydrophila, Edwardsiella tarda, Vibrio anguillarum, and Streptococcus sp. was compared with that of flounder(Paralichthys olivaceus) and seabass(Leteolabrax japonicus). And the activities of proteolytic enzyme, chitinolytic enzyme and haemolycin as non-specific defence factor were investigated on the oblong rockfish and rockfish. Samples from oblong rockfish showed the highest antibacterial activity by lysoplate assay on agar plate mixed with pathogens, followed in descending order by rockfish, seabass, and flounder. Turbidimetric assay was carried to evaluate the lysozyme activity of fish samples against lyophilized cells of Micrococcus lysodeiktikus. The serum, kidney, liver, stomach, intestine and eyeball of oblong rockfish and the mucus and gill of rockfish appeared to have the highest lysozyme activity among the fish strains investigated. All samples except skin mucus, liver, and eyeball of oblong rockfish and rockfish showed proteolytic enzyme activity. Chitinolytic enzyme activity was showed in random sampling and haemolytic activity was remarkable in oblong rockfish. Therefore, Sebastes strain was proved to have effective defense mechanisms based on the antibacterial activities, and lysozyme, proteolytic enzyme, chitinolytic enzyme, and haemolycin were considered to act as the non-specific defence factor of Sebastes.

• Journal of fish pathology
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• v.13 no.2
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• pp.121-127
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• 2000

From August to October 1998, over 60% mortality of cultured striped beakperch Oplegnathus fasciatus was occurred in net cages along the southern coast of Korea. Moribund fish showed some clinical signs of lethargic behavior, dark coloration or decoloration, severe gill anemia and enlargement of spleen. Also enlarged basophilic cells showing Feulgen -positive reaction were observed in the tissue section of spleen, kidney, liver and heart of the diseased fish. GF cells inoculated with spleen homogenate of diseased fish produced cytopathic effect of enlarged and rounded cells, therefore the causative virus was isolated from diseased fish. Striped beakperch fingerlings intraperitoneally inoculated with the causative virus ($10^4TCID_{50}$/0.1 ml) revealed symptoms similar to those of naturally infected fish and died from 7 to 14 days post injection. Transmission electron microscopy revealed that the causative virus was enveloped icosahedral particle with 120~130 nm in diameter. PCR products of the expected size (500 bp) were amplified with a primer set based on the ATPase gene of RSIV(red sea bream iridovirus) using template DNAs which were extracted from the spleen of diseased fish and GF cells inoculated with the causative virus. According to the analysis of nucleotide sequence of these PCR products, the sequence from ATPase cDNA gene of the causative virus showed 95% homology with that of RSIV. These results indicate that the mass mortality in the cultured striped beakperch was caused by the infection of iridovirus similar to RSIV.