• Journal of fish pathology
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• v.22 no.3
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• pp.383-389
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• 2009

Analysis of expressed sequence tags (ESTs) is an efficient approach for gene discovery, expression profiling, and development of resources useful for functional genomics studies. As part of studies on the immune system of olive flounder, a total of 251 EST sequences from gill cDNA library were generated to identify and characterize important genes in the immune machanisms of olive flounder. Of the 251 clones, 126 clones (50.2%) were identified as orthologues of known genes from olive flounder and other organisms. Among the 126 EST clones, 16 clones (12.7%) were representing 9 unique genes identified as homologous to the previously reported olive flounder ESTs, 100 clones (79.4%) representing 103unique genes were identified as orthologs of known genes from other organisms. We also identified several kinds of immune associated proteins, indicating EST as a powerful method for identifying immune related genes of fish as well as identifying novel genes. Further studies using cDNA microarrays are needed to identify the differentially expressed transcripts after disease infection.

• Journal of fish pathology
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• v.16 no.2
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• pp.91-102
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• 2003

The present study was investigated the effects of chlorine dioxide ($CIO_2$) on the rcspimtory metabolism of olive flounder (Parolichlhys olivaceus) imtermittently exposed to seawater chlorinated by $CIO_2$:. Oxygen consumption of flounder before and after once or twice $CIO_2$-treatment with 12 hr- or/and 24 hr-interval were serially measured with automatic intenniteent-flow respirometer system (AIRS). The oxygen consumption rates of flowKier exposed to 0.10 and 0.20 ppm$CIO_2$, were not different from the control fish prior to the once or twice chlorinations . On the other hand, the respiratory metabolic rates of flounder exposed to 0.30 ppm$CIO_2$ were significantly increased 15% and 22 - 23% after the once and twice chlorinations compared to the control fish. respectively. The flounder exposed In 0.40 and 0.50 ppm$CIO_2$: died within 4 hr and I hr. respectively. The elevation( respiratory metabolism in flounder exposed toO.30 ppm$CIO_2$ and above is considered due to physiological stress caused by $CIO_2$ exposure.

• Journal of fish pathology
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• v.21 no.3
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• pp.209-217
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• 2008

A disease with mass mortality characterized exophthalmia and abdominal distension by ascites occurred in farmed starry flounder, Platichthys stellatus in Pohang since October of 2007. Severe necrosis and infiltration of inflammatory cells were observed in tissue histopathological sections from liver, kidney, spleen and heart of the diseased fish. The catalase-negative and gram positive cocci with -hemolysis were isolated from moribund fish. Analysis of the API profiles and the multiplex PCR of the isolates showed that strains were identified as Streptococcus parauberis. In API profiles, S. parauberis isolated from starry flounder differed from those of olive flounder, Paralichthys olivaceus to the test of arginine dihydrolase, D-mannitol, D-sorbitol and α-lactose. And the strains, PH0710 and PH0711, were strongly lethal for starry flounder (LD50 ranging from 4.2×103~4.2×102 cfu/fish at 7 days after intraperitoneally inoculation). This is the first report on a S. parauberis infection in starry flounder.

• Journal of Aquaculture
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• v.13 no.2
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• pp.181-186
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• 2000

Relationship between hsp 70 expression and development of thermotolerance in the olive flounder was investigated by exposing the fish to 23 or 26$^{\circ}C$ for 1 h. After selected intervals, they were re-exposed to 31$^{\circ}C$ for a duration of 15 min. Theremotolerance rapidly developed with increasing interval and peaked at 3 h interval. Subsequently, it gradually decayed and disappeared by 24 h interval. The flounder displayed remarkably high levels of hsp 70 mRNA and protein, as compared to control flounder. Hence, the olive flounder acquires thermotolerance, which is positively correlated with the synthesis of hsp 70.

• Journal of fish pathology
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• v.23 no.3
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• pp.379-388
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• 2010

This paper presents a computer program for easy and rapid disease diagnosis of olive flounder diseases. To design the program, standard diagnosis process of the 14 olive flounder diseases was first setup, then implemented four-steps diagnosis program. To run program, first input fundamental information such as water temperature, size of the diseased fish. Then sequentially, three categories of key factors for disease diagnosis which include external clinical signs, internal clinical signs and microscopic observations are selected. When a user selects the observed signs of olive flounder from the listed options, the program provides maximum 5 presumed disease candidates in order. The disease information, treatment and prevention methods are provided by connected web server through internet. The program would support fish doctors and farmers by providing easy and rapid diagnosis of diseased olive flounder.

• Fisheries and Aquatic Sciences
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• v.26 no.10
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• pp.605-616
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• 2023

Scuticociliatosis, caused by the parasitic pathogen Miamiensis avidus, poses a significant threat to olive flounder farms in South Korea. Infected fish suffer from severe systemic infections affecting various organs, with potential secondary bacterial diseases. This study investigated the emergence of different M. avidus serotypes in 20 olive flounder farms on Jeju island, South Korea, from 2015 to 2020. Additionally, we identified Tenacibaculum maritimum as a co-infecting bacteria. Based on serotyping and monitoring data, we developed a trivalent vaccine targeting two serotypes of M. avidus and one strain of T. maritimum. The efficacy of the vaccine was evaluated under laboratory conditions and demonstrated a relative percentage of survival (RPS) of 75%, 80%, and 93% for M. avidus serotype I, M. avidus serotype II and T. maritimum, respectively. Furthermore, successful field trials conducted on four different olive flounder farms resulted in significantly higher survival rates (52%-76% RPS) and weight gains in vaccinated fish. Overall, this study presents an effective vaccine against M. avidus and T. maritimum infections in farmed olive flounder, making a valuable contribution to sustainable aquaculture in South Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.93-97
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• 2000

This study was carried out to investigate the effect of rotifer fed the different diets in high density culture on larval flounder Paralichthys olivaceus. Potifer was enriched with enrichment supplements, Marine ${\alpha}\;and\;{\omega}-yeast$ for 6 hours after being cultured with freshwater Chlorella for 18 hours during high density culture before it was fed to larval flounder. And rotifer was culutured with marine Chlorella and freshwater Chlorella for 24 hours during semi-continuous high density culture before it was fed to larval flounder. Culture tanks(21 working volum) set for rotifer culture in a water bath($28{\circ}C$) were continuously supplied with oxygen gas. The content of n-3 HUFA to fatty acids in rotifer(dry weight ${\%}$) enriched with Marine ${\alpha}$ for 6 hours and cultures with marine Chlorella for 24 hours were higher than that in rotifer enriched with ${\omega}-yeast$ for 6 hours or cultured with freshwater Chlorella for 24 hours. The growth and survival rates of larval flounder fed on rotifer enriched with Marine ${\alpha}$ for 6 hours and cultured with marine Chlorella for 24 hours were higher than those of larval flounder fed on rotifer enriched with ${\omega}-yeast$ for 6 hours or cultured with freshwater Chlorella for 24 hours. And the content of n-3 HUFA of larval flounder fed on rotifer enriched with Marine ${\alpha}$ for 6 hours was higher than that of larval flounder fed on other rotifers, The results from this study indicated that rotifer culture with marine Chiorelia would be suitable for the high density culture and effective diet for the growth of larval flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.4
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• pp.411-416
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• 2015

Olive flounder Paralichthys olivaceus production has increased gradually in recent years, but prices have fallen. Thus, the development of a variety of processed foods incorporating olive flounder would help to increase the income of fishermen. This study was conducted to investigate the best method for olive flounder ball processing. Clean olive flounder were divided into five portions. Olive flounder meat (100 g with added egg white 39 g) was chopped and then mixed with 10 mL fresh cream and ingredients. The dough was molded into the shape of a ball. The olive flounder balls were then processed by two different methods. In the first method, the flounder ball was boiled in water for 3 min then vacuum-packed in polyethylene film and stored at $-20^{\circ}C$ for 7 days. After 7 days, the ball was thawed and heated in a microwave for 2 min (Sample-1). In the second method, the ball was vacuum-packed in polyethylene film without boiling and then stored at $-20^{\circ}C$ for 7 days before thawing and boiling in water for 3 min (Sample-2). After heating, both types of olive flounder balls were evaluated. Various factors (including the viable bacterial count, chemical composition, pH, hardness, thiobarbituric acid level, salinity, and free amino acid content) were measured, and a sensory evaluation was conducted. Based on the results of the sensory and hardness evaluations, Sample-1 was deemed to be superior to Sample-2.

• Journal of Aquaculture
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• v.10 no.2
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• pp.179-187
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• 1997

Early development growth and sexual phenomena of the hybrid between male spotted flounder (Verasper variegatus) and female olive flounder (Paralichthys olivaceus) were investigated. The hybrid produced was newly called the "Bumnupchi" in Korean name, "Mottled flounder" in English name. Fertilization rate, hatching rate and early survival rate of the mottled flounder were 56.9~72.3%, 86.7~92.5% and 89.1~96.0%, respectively. At 50th day and 240th day after hatching, they were 2.1$\pm0.2cm\;and\;22.9\pm2.1cm\;in\;total\;length, \;0.10\pm0.002g\;and\;179.0\pm38.5g$ in body weight, respectively. Eye position of the mottled flounder was mixed with both dextral (77.7%) and sinistral type (22.3%). Gonads were differentiated into ovarian type and testis type at 80th day after hatching, and its ratio was 1:1 (P>0.05). Most Gonads seemed to be sterile without having germ cell, whereas only 3.6% of investigated indiciduals turned out to have oocytes in the gonad. When the induction of sex reversal were attempted by daily oral administration of $17\beta$-methyltestosterone (0.5mg/kg fish) andestradiol-17$17\beta$(0.5mg/kg fish)from 40th to 100th day after hatching, both testis and ovary type were induced 81.9% and 87.7% of each hormone-treated fish, respectively.fish, respectively.

• Food Science and Preservation
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• v.16 no.1
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• pp.128-133
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• 2009

We performed an experiment of keeping the extension of raw and semi-dried flounder (Pleuronectes herzensteini). The effect of with (WG) or without gill (OG), drying degree (20% drying: 20D, 40% drying: 40D) and storage temperature($5^{\circ}C$) and 0.1% chitosan-ascorbate (CA) treatment of vacuum packaging flounder on the growth of contaminated microorganism during storage for 10 days were investigated. Total aerobacter (TA) in the OG-treated raw flounder was $0.29{\sim}0.44$ log cycle lower than that of WG-treated flounder. Also, the number of Staphylococcus aureus (SA) and E. coli (EO) in OG were lower compared with WG. The number of TA, SA and EO in 20 D among 0 D, 20 D and 40 D stored at $5^{\circ}C$ were lowest. Especially, the SA and EO was $0.13{\sim}0.53$, 0.3-0.88, and 0.13-0.74 log cycle lower compared with raw flounder. The growth of TA, SA and EO separated from raw flounder in tryptic soy broth were completely inhibited by 0.1% CA. The anti-biotical effect of CA of two microorganisms SA and EO that separated from flounder, and the growth of all of them were 90% (SA), 96% (EO) inhibited at the 0.1% CA. The inhibition times at $37^{\circ}C$ in soy broth was 36 hr. However when CA was added directly to flounder, it appeared inhibition effect to 0.88 log cycle. The effect of CA was better when gills removed and 20% drying.