• Journal of Aquaculture
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• v.12 no.2
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• pp.91-100
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• 1999

The complete nucleotide sequence of olive flounder (Paralichthys olivaceus) hsp70-related rDNA was determined by RT- and RACE-PCR methods. A full-length of hsp70-related cDNA has an open reading frame of 1.95 kb encoding 650 amino acids with a calculated molecular weight of 71.1 kD. A corresponding hsp70-related protein contains a number of conserved elements including an ATP-binding domain, a nuclear localization signal and the carboxyl terminal motif, EEVD, which may have a role in chaperone function. Comparison of nucleotide and predicted amino acid sequence between olive flounder hsp70-related gene and hsp/hsc70 genes of other species revealed a high similarity with the cognate form of these genes. These results indicated that we recovered likely to be a olive flounder cognate hsc70 gene.

• Development and Reproduction
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• v.23 no.1
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• pp.55-61
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• 2019

To develop a promoter capable of driving transgene expression in non-model fish, we identified and characterized the muscle-specific alpha-actin gene in olive flounder, Paralichthys olivaceus (PoACTC1). The regulatory region of PoACTC1 includes putative regulatory elements such as a TATA box, two MyoD binding sites, three CArG boxes, and a CCAAT box. Microinjection experiments demonstrated that the regulatory region of PoACTC1, covering from -2,126 bp to +751 bp, just prior to the start codon, drove the expression of red fluorescent protein in developing zebrafish embryos and hatching olive flounder. These results suggest that the regulatory region of PoACTC1 may be useful in developing a promoter for biotechnological applications such as transgene expression in olive flounder.

• Journal of fish pathology
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• v.31 no.2
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• pp.101-107
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• 2018

Quantitative analysis of a myxosporean parasite, Parvicapsula sp. in internal organs (kidney, intestine, spleen, brain and liver) from non-emaciated (farm-A) or emaciated (farm-B and farm-C) olive flounder Paralichthys olivaceus were performed by real-time PCR. The highest DNA copy number ($1.7{\times}10^7copies/mg$ tissue) was detected in kidney of the emaciated olive flounder from farm-C, while the DNA copy number was below detection limit in all the organs of the olive flounder from farm-B. There was not positive result in all of organs from olive flounder in farm-A. PCR and histopathological analysis were also performed using the same specimen and showed same results as those by real-time PCR.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.716-720
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• 2023

This study was designed to analyze the effects of reducing water turnover in olive flounder Paralichthys olivaceus farms, focusing on olive flounder growth, decreasing electricity costs, and developing measures to ensure business stability. Daily water turnover was set at 18 in the control group and six in the experimental group. Juvenile fish were reared for 12 months. No significant differences in mean weight were observed between groups until five months. After five months, the mean weight of the control group grew significantly faster than that of the experimental group. Maintaining water turnovers leverl at six turnovers for the first five months after stocking juvenile fish and then increasing water turnover resulted in a 34.4% reduction in electricity costs compared to the control group. This approach presents a potential method to enhance the profitability of olive flounder farms and ensure stable productivity and profitability without sacrificing olive flounder growth.

• Journal of fish pathology
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• v.37 no.1
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• pp.123-132
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• 2024

Viral diseases cause enormous economic losses to the olive flounder (Paralichthys olivaceus) aquaculture industry in Korea. This study aimed to identify immune-related genes expressed in the kidney of olive flounder injected with Polyinosinic-polycytidylic acid (Poly (I:C)). Thirty fish were divided into two groups by intraperitoneal injection of 100µl of diethylpyrocarbonate-treated water or poly I:C per fish. Kidney tissues at day 3 and 30 after the injection were used for RNA-seq analysis to identify differentially expressed genes (DEGs). Poly I:C group upregulated il8, cfh, tnfaip2b, c3b.2, ly6d and cd38 genes at 3 days post-injection. Additionally, cd22, ccl34a.3, c9, cxcl19, ccl27a, ccl7, and cfh genes were upregulated at 30 days post-injection. Differential expression gene analysis showed that poly I:C has both short and long-term immune effects in olive flounder. This study provides a theoretical basis for understanding the molecular mechanism of the short and long-term immune effects of poly I:C.

• Korean Journal of Environmental Biology
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• v.21 no.4
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• pp.352-357
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• 2003

Phenanthrene, one of Polycyclic aromatic hydrocarbons with three aromatic rings, is a ubiquitous contaminant in the environment. Phenanthrene has been identified in ambient air, drinking water and sediment. We examined the effect of phenanthrene on steroid hormones level of olive flounder, Paralichthys olivaceus. Plasma testosterone level was increased significantly in fish exposed to phenanthrene($\geq1.0 \mu M$) at 4th week. However, there was no significant changes of estradiol-17$\beta$ concentration in fish exposed to phenanthrene. The physiological variation in phenanthrene exposed fish was a dramatic increase in plasma cortisol level. It is concluded that chronic exposure of phenanthrene can induce increase of plasma testosterone levels and elevate the plasma cortisol level in flounder, Paralichthys olivaceus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.671-674
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• 2016

We cytogenetically analyzed a triploid King-Nupchi strain of the olive flounder Paralichthys olivaceus to define the simplest, most rapid, and most effective method of ploidy analysis in aquaculture farms. Female triploidy of the flounder King-Nupchi strain was induced by cold shock (3 min post-fertilization at 2-4℃ for 45 min). Triploid induction was confirmed by erythrocyte measurement (nuclear volume, 29.15±2.10 μm³); flow cytometry (2.14±0.03 pg/cell); chromosome count (3N=72); Ag-NOR banding; and silver staining. Silver staining of finned cells obtained using a solid tissue technique was the most effective method of ploidy verification.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.756-759
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• 2010

The feeding habits of olive flounder, Paralichthys olivaceus were studied using 126 specimens collected from coastal waters off Taean, Korea from April 2008 to March 2009. The total lengths of P. olivaceus ranged from 16.7 to 40.6 cm. P. olivaceus was a piscivore that consumed mainly fishes. The diet also included small quantities of shrimps, cephalopods, polychaetes and mysids. Although, P. olivaceus mainly consumed fishes of all size classes, some degree of change in diet composition was found; i.e. after fishes, smaller individuals fed more on shrimps, whereas larger individuals consumed more cephalopods.

• Environmental Analysis Health and Toxicology
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• v.17 no.1
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• pp.13-19
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• 2002

Effects of Formalin treatment on embryogenesis and larvae growing in fertilized eggs and hatched larvae of olive flounder, Paralichthys alivaceus were investigated. Fertilized eggs and hatched larvae were exposed to aqueous solution with 100, 200, 400, 800 and 1,000 ppm of nominal formalin concentration. They were kept in sea water of 16, 18 and 22$^{\circ}C$, respectively. Survival rate and hatchability of fertilized eggs were high in control groups more than formalin treated groups in 16, 18 and 22$^{\circ}C$, respectively (P<0.05). A similar effect that survival rate of hatched larvae was also observed for control and treatment groups. On the other hand, fertilized eggs treated with 400 ppm formalin, were all death in kept in 22$^{\circ}C$. These results suggest that high-dose of formalin in fertilized eggs and hatched larvae in olive flounder, Paralichthys olivaceus was inhibited the normal embryogenesis for fertilized eggs and growing for hatched larvae. Also, these inhibited effects was promoted in higher temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.785-790
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• 2011

This study investigated the nutritive quality of olive flounder Paralichthys olivaceus fed either moist pellet (MP) or moist pellet mixed with mushroom extract (MPME) for 6 months. There was no significant difference in crude protein or extractive nitrogen in the muscle of flounder fed MP versus MPME (P > 0.05). The total amino acid content in the muscle of flounder fed MP was $15.22{\pm}5.24$ g/100 g, compared to $19.90{\pm}2.90$ g/100 g for flounder fed MPME. Essential amino acid content was $7.04{\pm}2.21$ g/100 g in the muscle of flounder fed MP versus $8.94{\pm}2.50$ g/100 g for MPME. Total amino acid content was higher in the muscle of olive flounder fed MPME, while essential amino acid content was higher in flounder fed MP. The ratio of non-essential amino acids to essential amino acids was $0.86{\pm}0.07$ for flounder fed MP and $0.81{\pm}0.08$ for flounder fed MPME. There was no significant difference in free amino acid content and fatty acid composition. The breaking strength of muscle of olive flounder fed MP was higher ($1.44{\pm}0.51\;kg/cm^2$) than in flounder fed MPME ($1.29{\pm}0.30\;kg/cm^2$). There was no evidence that dietary additives, such as mushroom extract, increase growth rate or nutritive quality of olive flounder.