• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.344-353
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• 2021

Juvenile olive flounder, Paralichthys olivaceus (mean weight 66.7±7.1 g; mean length 19.2±0.9 cm) in a bio-floc environment were exposed to microplastic (PE: polyethylene, size 40-48 ㎛) at 0, 4, 20, 100, 500 and 2,500 mg L^-1 for 96 hours. No P. olivaceus deaths were observed following microplastic exposure. In the plasma components, calcium was significantly decreased whereas there was no significant change with magnesium following microplastic exposure. Glucose was significantly decreased with over 100mg L^-1 at 48 hours and 20mg L^-1 at 96 hours. Cholesterol was significantly decreased with over 20mg L^-1 after 48 hours, whereas there was no significant change in the total protein content. In enzymatic plasma components, the AST(Aspartate aminotransferase) was significant decreased by microplastic exposure. The results of this study indicate that acute exposure to microplastic induces blood physiological changes in P. olivaceus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.2
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• pp.141-148
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• 2019

This study examined the effect of insulin-like growth factor (IGF)-I expression in the liver and muscle on the growth of Paralichthys olivaceus fed diets low in fish meal. A feeding experiment was conducted at Jeju National University, Jeju Island, Korea. Groups of P. olivaceus (total initial weight: 200 g) were maintained for 20 weeks on one of five experimental diets containing different proportions of fish meal. Diets containing 0%, 20%, 30%, 40%, and 50% fish meal were labeled FM0, FM20, FM30, FM40, and FM50, respectively. Fish growth was observed every 4 weeks during the feeding experiment, and plasma and liver and muscle tissues were sampled. Plasma IGF-I levels were analyzed using an ELISA kit. The mechanism of IGF-I receptor signaling was examined using immunoblotting and reverse transcription-polymerase chain reaction. The greatest total weight increase was observed in the FM30 group. In parallel, plasma levels of IGF-I and IGF-binding protein were highest in the FM30 group, and mRNA and protein expression were also significantly higher in this group. The first step in the IGF-I signaling pathway, tyrosine-phosphorylation checking, occurred smoothly until 20 weeks. These results suggest that a dietary ratio of 30% fish meal best promotes growth in this species. The IGF-I signaling pathway in the liver and muscle is associated with growth in P. olivaceus.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.5
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• pp.1470-1478
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• 2015

Adjuvant is an immune enhancer commonly used during vaccination to enhance the host immune response. In the present study, we produced the several recombinant protein from immune related gene of olive flounder (Paralichthys olivaceus). Especially, to produce the soluble type of recombinant protein, we constructed the MBP (Maltose binding protein) fusion G-CSF (Granulocyte colony stimulating factor) recombinant protein among the flounder immune related genes. To verify the immune stimulatory effect and safety of this recombinant protein (rPoGCSF), expression changes of several immune genes were tested using quantitative real-time PCR method with gene specific primer from flounder head kidney leukocytes. As a result, we confirmed that the rPoGCSF has an ability of immune stimulatory effect, also it has broad range of pH and temperature.

• 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.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.133-138
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• 2004

A lot of cultured flounders died by ascitic disease blooming during the summer season in 2002, southern parts of Korea. This study was conducted to investigate the microbial flora for the ascitic cultivated olive flounder (Paralichthys olivaceus) which were collected in the Koe-je island in the southern of Korea from July 2002 to October 2003. Three Genera (Vibrio, Photobacterium and Edwardsiella), seven species of bacteria (V. harveyi, V. alginolyticus, V. parahaemolyticus, V. carcariae, V. metschenikovii, P. damsela and E. tarda) and a fish pathogenic birnavirus (marine birnavirus, MABV) were isolated from the liver, dropsy, spleen and identified by biochemical and molecular biological characterization.

• Development and Reproduction
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• v.22 no.3
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• pp.283-288
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• 2018

The author carried out PCR-based genetic platform to investigate the hierarchical polar dendrogram of Euclidean genetic distances of one bastard halibut population, particularly for Paralichthys olivaceus, which was further connected with those of the other fish population, by involving with the precisely designed oligonucleotide primer sets. Eight oligonucleotides primers were used generating excessively alterating fragments, ranging in size of DNA bands from larger than approximately 100 bp to less than 2,000 bp. As regards average bandsharing value (BS) results, individuals from Hampyeong population (0.810) displayed lower bandsharing values than did individuals from Wando population (0.877). The genetic distance between individuals approved the existence of close relationship in the cluster II. Relatively, individuals of one bastard halibut population were fairly related to that of the other fish population, as shown in the polar hierarchical dendrogram of Euclidean genetic distances. The points of a noteworthy genetic distance between two P. olivaceus populations demonstrated this PCR procedure is one of the quite a few means for individuals and/or populations biological DNA investigates, for species security and proliferation of bastard halibut individuals in coastal region of the Korea.

• Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.123-129
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• 2011

To determine whether rearing density affects the hypermelanosis on the blind side (ambicoloration) of olive flounders Paralichthys olivaceus, we reared fry with an unpigmented non-eyed (blind) side in duplicate at densities of 150 individuals/$m^2$ (commercial production density: control) and 450 individuals/$m^2$ (high density group) for 90 days in 1-t dark-green fiberglass reinforced plastics (FRP) tank. We recorded feed intake, feed conversion efficiency (FE), growth and survival, and measured the ratios of staining blind-side area (staining area) and ambicolored fish every 30 days. Daily feed intake (DFI), feed conversion efficiency (FE), growth rate, condition factors, and survival rate were calculated at the end of the experiment. Although the FE was higher in the high-density compared to the control, the two density groups showed similar feed intakes, growth, and survival. The ratio of staining area as well as the ratio of ambicolored fish significantly were significantly higher in the high-density group than in the control from days 30 to 60, but significantly increased and evened out by the end of the experiment (P<0.05). In conclusion, we determined that rearing density is not the main cause of the blind-side hypermelanosis, but found that increasing the rearing density can accelerate the ambicoloration in olive flounders.

• Journal of Aquaculture
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• v.12 no.2
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• pp.79-89
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• 1999

The recombinant bovine somatotropin (rBST) was administered to the oliver flounder, Paralichthys olivaceus, to know the effects and optimal administration frequency and dosage of the hormone. The experiment was conducted with three different treatment groups (A, B and C) designated based on the duration and administration frequency of rBST and one control (D) from April 14, 1996 to March 16, 1997. The fish of hormone treated groups grew 7.86 to 10.07% (47.45 to 60.75 g in weight) better than the control at the end of the experiment (P<0.05). No significant differences in their growth were detected among treatment groups. The distinct growth improvement was recognized four weeks after completion of the first four hormone administration. When considering water temperatures measured from the experimental tanks, the effect of rBST on the flounder was greater during the period showing relatively lower temperature. The survival rates were higher in treatment groups than in the control, revealing 98.3% (A), 98.4% (B), 97.7% (C) and 93.1% (D) during the first stage of culture; 92.7% (A), 91.3% (B), 86.7% (C) and 80.0% (D) during the second stage of culture.

• 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.

• Fisheries and Aquatic Sciences
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• v.20 no.6
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• pp.10.1-10.7
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• 2017

Small GTPases are well known as one of the signal transduction factors of immune systems. The ADP-ribosylation factors (ARFs) can be classified into three groups based on the peptide sequence, protein molecular weight, gene structure, and phylogenetic analysis. ARF1 recruits coat proteins to the Golgi membranes when it is bound to GTP. The class I duplicated ARF gene was cloned and characterized from the olive flounder (Paralichthys olivaceus) for this study. PoARF1b contains the GTP-binding motif and the switch 1 and 2 regions. PoARF1b and PoARF1b mutants were transfected into a Hirame natural embryo cell to determine the distribution of its GDP/GTP-bound state; consequently, it was confirmed that PoARF1b associates with the Golgi body when it is in a GTP-binding form. The results of the qPCR-described PoARF1b were expressed for all of the P. olivaceus tissues. The authors plan to study the gene expression patterns of PoARF1b in terms of immunity challenges.