• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.499-500
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• 2006

• Journal of Life Science
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• v.7 no.1
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• pp.1-9
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• 1997

For the recent years, considerable efforts have been made to rationalize the techniques of research and monitoring of biological effects of marine pollutants such as heavy metals, polychlorinate biphenyls (PCBs), organochlorine pesticides, polycyclic aromatic hydrocarbons (PAHs), organophosphorus pesticides. This study was designed as a part of efforts to investigate the biochemical pollutant markers for diagnosis of marine pollutions by the changes in lipid components of the flounder (Paralichthys olivaceus) in Yellow Sea of Korea. Homoglobin levels in serum of cultured and wild flounders in Yellow Sea were significantly lower (5 - 15% and 20 -25 % , respectively) than those of wild flounder in Pohang. Triglyceride (TG) contents in serum of cultured flounders in Yellow Sea were 10 - 40% higher than those of wild flounder in Pohang. Total and low density lipoprotein (LDL)-cholesterol contents in serum of flounders in Yellow Sea were significantly 10-15% and 30-35% (cultured), and 10-20% (wild), respectively, higher than those of wild flounder in Pohang. Atherogenic index (AI) and T-Chol/PL rations in serum of cultured and wild flounders in Yellow sea were significantly 20-45% and 10-!5%, 6-35% and 15-35%, respectively, higher than those of wild flounder in pohang. These results suggest that near-coastal waters as well as neritic waters of the Yellow Sea might be affected by pollutant input.

• Journal of fish pathology
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• v.16 no.3
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• pp.183-191
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• 2003

The effect of each dietary supplements (Undaria 5%, Undaria 10%, Obosan 0.5%, Wasabi leaf 2%, Wasabi stem 2%) on the water temperature fluctuation in juvenile olive flounder (Paralichthys olivaceus) was investigated. The response to stress was assessed in terms of effects on haematological and immunological, and resistance against Edwardsiella tarda infection. Plasma glucose and cortisol levels were significantly lower in 5% undaria and 2% wasabi leaf supplement groups than the controls after the first change of water temperature (P<0.05). The plasma lysozyme activities and the survival rates from E. tarda infection were significantly higher in the 5% undaria supplement groups than the control (P<0.05). These results suggest that the 5% undaria supplement seems to be contributable to the increased disease resistance on olive flounder.

• Journal of Life Science
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• v.19 no.1
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• pp.87-93
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• 2009

We have investigated the effects of the culture broth of lactic acid bacteria (LAB) cultured in herb extract on growth, hematological parameter, nonspecific immune responses and disease resistance of olive flounder (Paralichthys olivacells) and parrot fish (Oplegnathus fasciatus) for 12 weeks. Weight gain of olive flounder fed diet with mixture was not significant among the control group. But In parrot fish, was significantly higher 20g than control group. The feed efficiency of olive flounder were 25% higher in the experimental groups than in the control. There were no significant differences in feed efficiency among each group on parrot fish. Treatment of olive flounder contents of GOT and GPT in serum decreased after 8 weeks. But there were no significant differences in GLU and TP among each group. Also, there was no significant of NBT reduction. The activities of lysozyme were higher in experimental group of olive flounder than in the control after 8 weeks. On the other hand, activities of lysozyme were triple higher in the experimental group of parrot fish than in the control after 12 weeks. In the oliver flounder case, the survival rate (%) after an artificial challenge with $10^7$ CFU/ml of Vibrio anguillarum and Streptococcus iniae per fish, was 18% higher in the experimental groups than the control. The higher survival rate of parrot fish were 17% and 16% in the experimental groups than the control respectively.

• Journal of fish pathology
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• v.25 no.3
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• pp.263-270
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• 2012

This study surveyed for the prevalence of parasites, bacteria and viruses in four fish species, olive flounder (Paralichthys olivaceus), red sea bream (Pagrus major), black sea bream (Acathopagrus schlegeli) and black rockfish (Sebastes schlegeli) in 2010. The survey was aimed to compare the pathogens detected from wild and cultured fish for an epidemiological study. Anisakis sp. was predominantly detected from wild olive flounder and red sea bream (58.6% and 41.7% respectively), but not from the cultured fishes, suggesting anisakid infection is rare in cultured fish. The wild fish get in contact with the anisakids through their prey such as small fishes or crustaceans which carry the anisakids; whereas the cultured fish are fed with formulated feed, free of anisakids. Bacterial detection rates from the wild fishes examined in the study were lower than those of cultured fishes. Vibrio sp. dominated among detected bacterial population in cultured olive flounder (18%). Since vibriosis is known as a secondary infection caused by other stressful factors such as parasitic infections, handling and chemical treatment, it seems that cultured olive flounder are exposed to stressful environment. Viruses diagnosed in the study showed difference in distribution between wild and cultured fishes; hirame rhabdovirus (HRV) (0.1%) and lymphocystis disease virus (LCDV) (3.9%) were detected in the cultured olive flounder, but not in the wild fish, and marine birnavirus (MBV) (1.7%) and red sea bream iridovirus (RSIV) (3.2%) were detected from the wild and cultured red sea bream, respectively. From the survey conducted, it can be concluded that even though some pathogens (Trichodina sp., Microcotyle sp., etc.) are detected from both the wild and cultured fish, pathogens such as Anisakis sp., Vibrio sp. and LCDV showed difference in distribution in the wild and cultured host of same fish species and this can be attributed to their environmental condition and feeding.

• Journal of fish pathology
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• v.28 no.3
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• pp.165-169
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• 2015

Occurrence of Scuticociliatosis in olive flounder farm of Jeju was monitored from 2007 to 2014. As a result, 23.8~36.4% of referred samples were diagnosed as Scuticociliatosis. Based on fish size, the highest incidence (50.5%) was found in fish with size of 10~20 cm.

• Journal of fish pathology
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• v.32 no.1
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• pp.29-35
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• 2019

A monitoring was performed to survey the mortalities that had occurred in the aquaculture farms of olive flounder (Paralichthys olivaceus) in South Korea from 2015 to 2017. The indirect inquiry for entire farms and the sample survey for selected farms were carried out. The aquatic organism disease inspectors, who have a national license for the diagnosis and prevention of aquatic organism diseases and a have close relationship with the farms, investigated the rates and causes of mortalities according to the standard manual. The mortality rate by sample survey of farms in 2015, 2016, and 2017 were 24.78% (Chunnam: 17.86%, Jeju: 28.69), 30.19% (Chunnam: 24.45%, Jeju: 32.65), and 21.59% (Chunnam: 10.57%, Jeju: 26.00%), respectively. The major cause of mortality was scuticociliatosis, and the mortality caused by viral hemorrhagic septicemia and emaciation disease (Jeju) were also high. Our results can contribute to effective establishment prevention of epidemics system and acquired status as a disease-cleansing country.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.132-138
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• 2019

Among several marine-derived microorganisms isolated from the coast of Jeju Island that had antimicrobial activity against fish disease pathogens, Bacillus subtilis MD-02 was tested for its dietary effect on the innate immune response and disease resistance of olive flounder. Strain MD-02 was fed to the olive flounder at a concentration of $1.2{\times}10^4$, $1.2{\times}10^6$, or $1.2{\times}10^8CFU/100g$, respectively. Consequently, the hematocrit was higher in these three groups than that in the control group at 4 weeks, and the aspartate aminotransferase and alanine aminotransferase levels were decreased in the $1.2{\times}10^8$ and $1.2{\times}10^4CFU/100$ groups compared with the control group levels. The amylase activity and total protein were significantly increased in the $1.2{\times}10^4CFU/100g$ group at 3 weeks. The innate immune response, determined from the lysozyme and macrophage activities, was higher in the $1.2{\times}10^8CFU/100g$ group than in the control group. In addition, treatment of the olive flounders with Streptococcus parauberis at $1.2{\times}10^6CFU/ml$ confirmed the mortality rate, which was 100% in the control group and 40-60% in the groups fed B. subtilis MD-02, indicating that the fish had resistance to fish disease pathogens. Therefore, it was confirmed that when fed MD-02, olive flounder builds an innate immune response and acquires resistance to fish disease pathogens, indicating that B. subtilis MD-02 can be developed as a beneficial feed additive.

• Journal of fish pathology
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• v.27 no.1
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• pp.17-24
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• 2014

To study the possible use of probiotics in fish farming, The in vitro and in vivo antibacterial effects of Pseudomonas aeruginosa MB I-3 (MB I-3) against the fish pathogenic bacterium Listonella anguillarum were evaluated. The inhibitory effects of MB I-3 against vibrios were investigated by the double layer method and the co-culture. The results showed that MB I-3 inhibited the growth of pathogenic vibrios including Listonella anguillarum, Vibrio alginolyticus, Vibrio cholerae, Vibrio fluvialis, Vibrio furnissii, Vibrio harveyi, Vibrio parahaemolyticus and Vibrio vulnificus. Extracellular substances obtained from the cultural supernatant of MB I-3 by ethyl acetate extraction showed inhibitory effects on L. anguillarum. The antibacterial substance of MB I-3 was evaluated to destroy the cell membrane of L. anguillarum in electron micrographs. The probiotic effects of MB I-3 was tested by exposing olive flounder (Paralichthys olivaceus) fry to L. anguillarum with or without MB I-3. The cumulative mortality of olive flounder fry infected with L. anguillarum was 24% in the group with MB I-3, while it was 46% in the control group without MB I-3. These results indicate that MB I-3 has potential applications as a probiotic for the control of fish pathogenic vibrios in fish rearing system.

• Journal of fish pathology
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• v.27 no.1
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• pp.35-45
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• 2014

In this study, we investigated the effects of dietary 1% garlic extract on nonspecific immune responses and fish diseases (Viral Hemorrhagic Septicemia Virus, Vibrio anguillarum, Streptococcus iniae and Edwardsiella tarda) resistance in olive flounder Paralichthys olivaceus. Fish were fed a commercial diets supplemented with 1% garlic extract for 4 weeks. After the 4 weeks feeding experiment, the artificial infection was made by V. anguillarum, S. iniae, E. tarda and VHSV. And the cumulative mortality was monitored for 2 weeks after artificial infection. The cumulative mortalities decreased in all experiments except for group of E. tarda compared to control group. We observed significantly higher levels of the hematocrit, glucose, total protein, lysozyme activity and the macrophage activity in the experimental group compared to the control group. In the experiments of drug sensitivity and MIC using the three bacteria (V. anguillarum, S. iniae and E. tarda), 1% garlic extract was more effective than the previously reported fermented garlic powder. These results suggested that garlic extract can increase the disease resistance of olive flounder against V. anguillarum, S. iniae and VHSV and the ability of nonspecific immune responses.