• Fisheries and Aquatic Sciences
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• 제16권4호
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• pp.261-265
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• 2013

The study was conducted to investigate the responses of the hepatic microsomal cytochrome P450 monooxygenase system in the rock bream Oplegnathus fasciatus after chronic exposure to 0, 1, 2, 4, and $8{\mu}g/L$ tributyltin (TBT) concentrations for 4 weeks. Hepatic cytochrome 450 content and ethoxyresorufin O-deethylation (EROD) activity were found to significantly increase in fish treated with the higher concentration of TBT (${\geq}4{\mu}g/L$); however, no significant changes were observed in penthoxyresorufin O-deethylation (PROD) activity in all treated groups compared to the control group. These findings suggest that exposure to a low TBT concentration (${\geq}4{\mu}g/L$) has the potential to induce cytochrome 450 content and EROD enzyme activity in hepatic tissue in the rock bream.

• 수산경영론집
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• 제52권3호
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• pp.27-38
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• 2021

This study is aimed to figure out the productivity and variability of cage-aquaculture changes. According to the analysis, the productivity of major fish species has been increasing, except mullet. Although the regional productivity has decreased in the last two years, it has been on the rise considering as a whole. Gyeongsangnam-do showed the highest level of productivity by region. Productivity by species was also higher than other regions in the cases of rock fish, mullet and sea bream followed by productivity of Chungcheongnam-do. The production of marine cage-culture in Jeollanam-do is the second largest in Korea in value/weight while its productivity is lower than that of Chungcheongnam-do. When it comes to comparison by region, Gyeongsangnam-do shows the lowest productivity variation. And Jeollanam-do shows the second-lowest variation in productivity that is only about half of that of Chungcheongnam-do province. Thus, it is found that Jeollanam-do region has an advantage in management stability while its productivity is low. On the other hand, productivity by species was also analyzed. Gyeongsangnam-do has the highest productivity by species for rock fish, mullet and sea bream whereas rock bream productivity is the highest in Jeollanam-do. Therefore, it probably needs to reflect these results when choosing regional-focused incubation fish species.

• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.873-879
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• 2005

Red sea bream iridovirus (RSIV) obtained from infected rock bream was propagated by Bluegill fry-2 (BF-2) cell culture. The virus titer was determined as $10^{5.5}\;TCID_{50}/ml$ on confluent BF-2 cell monolayers. The integrin binding site of ORF 055L of infectious spleen and kidney necrosis virus (ISKNV) was selected for the construction of a primer to obtain the RSIV ORF 055L gene. The genes were amplified using RSIV gene lyzate by PCR. The homologies of the ORF 055L sequence of RSIV with ISKNV and rock bream iridovirus (RBIV) were approximately $96\%$ and $100\%$, respectively. DNA vaccine was constructed by cloning the ORF 055L of RSN into pcDNA 3.1 (+), containing a cytomegalovirus (CMV) promoter. For antibody production, pcDNA-055 DNA vaccine was injected to BALB/c mice. The production of antibodies against pcDNA-055 DNA vaccine was confirmed by the Western blot analysis. The antibodies produced by the pcDNA-055 DNA vaccine showed efficacy to neutralize the RSIV in the neutralization test in BF-2 cell culture.

• 한국어병학회지
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• 제37권1호
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• pp.25-36
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• 2024

In this study, we analyzed the phylogenetic classification, epitope prediction, and pathogenicity of red sea bream iridovirus (RSIV) isolated from rock bream between 2019 and 2023. Phylogenetics based on genes encoding MCP and ATPase indicated that all five RSIV isolates belonged to RSIV subtype II. The deduced amino acid sequence of the MCP for the amplicons (1362 bp) obtained from RSIV isolates had a length of 453 amino acids. Among these, the amino acid sequences of the RSIV-19, 21, 22, and 23 isolates showed 100% identity, while the RSIV-20 isolate showed 99.78% identity with one residue difference at position 306. As a result of antigenicity analysis based on amino acid sequence, the antigenicity score of the RSIV-20 isolate was 0.6386 and the other RSIV isolates were 0.6365. Additionally, the prediction of their antigenic determinants resulted in a total of 17 identical antigenic plots. When each RSIV was inoculated into rock bream, no significant differences were observed with 100% cumulative mortality in all groups. This study provides data on the potential for genetic variation of RSIV isolated in the same marine area over the past five years, and the antigenicity and pathogenicity results of each isolate are expected to be useful information for selecting future vaccine strains.

• 한국어병학회지
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• 제26권2호
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• pp.123-128
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• 2013

The outbreak of haemorrhagic speticemia and dermal lesions in cultured Rock sea breem in Jeju Island are frequently associated with keratitis. Prolonged infection leads to the symptoms accompanied by necrosis of fin and skin and the fishes died. Present study aims to study the histopathological changes of diseased fish muscle tissue. The tissue at the initial stage of infection showed normal muscular texture, however in the late stages of infection, muscular lesion had been expanded and hence, necrosis had progressed deeply into muscle tissue. Mild tissue in caudal fin was found with more necrosis, and gill tissues were also collapsed. In Kidney, renal tubules were teared along with tissue destruction (Espada, J et al, 1993). Hence in the present study, we examined the histopathological variation of the infection fishes, and this basic data would be used for future research of in haemorrhagic specticemia and dermal diseases.

• 한국어병학회지
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• 제19권3호
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• pp.277-284
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• 2006

최근 양식현장에서 양식기구 소독과 어병방역을 목적으로 목초액을 사용하고 있으나 목초액에 대한 정보는 거의 없는 실정이다. 본 연구에서는 목초액에 대한 어류독성을 검토하기 위하여 잉어, 넙치, 조피볼락 및 감성돔을 대상으로 독성 여부를 확인하였다. 목초액에 대한 반수치사 농도는 담수 어종인 잉어의 경우 48시간 LC50치가 1243 ppm, 넙치에서 1397 ppm으로 나타나 시험에 대상으로 한 다른 어종에 비해 높게 나타났으며, 조피볼락에서는 1058 ppm,감성돔의 경우는 LC50치가 650 ppm으로 조사되어 가장 낮게 나타났다. LC50 농도에 노출된 어체의 조직학적 관찰에서는 목초액이 처리된 모든 어체의 아가미에서 괴사, 증생 및 박리 등이 관찰되어, 아가미의 심각한 손상으로 삼투조절 및 산소공급에 문제가 있을 것으로 추정되었다.

• 수산해양기술연구
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• 제21권1호
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• pp.35-40
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• 1985

색망지에 대한 돌돔과 능성어의 선택반응을 조사하기 위하여 적색, 황색, 녹색, 청색 및 흑색의 다섯가지 색망지를 사용하여 시어의 반응을 조사한 결과는 다음과 같다. 1. 수조내에 색망지를 설치하지 않고 백색 배경 하에서 조사하였을 때, 돌돔과 능성어는 양 가쪽 구간중 어느 한 쪽으로 편중하여 분포하는 경향은 나타나지 않았다. 2. 돌돔은 수조의 양 가쪽 구간에 색망지를 설치한 경우가 설치하지 아니한 때보다 중간 구간에 많이 모였으나, 능성어에서는 반대로 나타났다. 3. 돌돔이 많이 선택한 색망지의 순위는 황색, 흑색, 청색, 녹색, 적색의 순으로 나타났다. 4. 능성어가 많이 선택한 색망지의 순위는 녹색, 흑색, 적색, 청색, 황색의 순으로 나타났다.

• 한국수산과학회지
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• 제39권2호
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• pp.66-71
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• 2006

Fluoroquinoles have a wide range of antimicrobial properties and are effective in the treatment of bacterial diseases in fish. The use of fluoroquinoles continues to grow steadily. Fluoroquinolone antibiotics are probably the most important class used among synthetic antibiotics in human and veterinary medicines because of their broad activity spectrum and good oral absorption. This study was conducted to estimate the residue of antibiotics in four species of farmed fishes, including olive flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagrus major), and sea bass (Lateolabrax japonicus), collected from fish farms located in the southern coastal area of Korea. The residues of fluoroquinolones were determined using high performance liquid chromatography (HPLC) with a fluorescence detector. Residuals of five fluoroquinolones in muscle tissue of farmed fish were analyzed. We found that enrofloxacin was the most common agent in fish muscle, and that ciprofloxacin was the next most common. The range of detected concentrations of fluoroquinolones in olive flounder muscle was 0-0.859 mg/kg in 32.6% of all samples. Enrofloxacin was commonly detected in sea bass muscle at a range of 0-0.143 mg/kg in 38.9% of all samples. Fluoroquinolones were detected in 6.9% of black rock fish muscle and in 16.6% of sea bream, although the detected concentration was below 0.01 mg/kg. The maximum detection value of enrofloxacin and ofloxacin in olive flounder at the time of shipping was 0.102 mg/kg and 0.09 mg/kg, respectively; no other antimicrobials were detected. We detected no antimicrobial substances in red sea bream.

• Fisheries and Aquatic Sciences
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• 제9권4호
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• pp.146-152
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• 2006

Systemic infections of maricultured fishes by Megalocytivirus species have occurred over a broad area in South Korea, causing extensive economic loss. We developed digoxigenin-labeled nucleic acid probes against the 230-bp ATPase and 311-bp major capsid protein (MCP) of rock bream Oplegnathus fasciatus iridovirus (RBIV) using polymerase chain reaction, and an in situ hybridization (ISH) method to detect Megalocytivirus in formalin-fixed tissues of mariculture species (rock bream, sea bass, and olive flounder). ISH-positive cells were abundant in the hematopoietic and connective tissues of various organs, while brain tissue showed little or no signal. The ISH procedure can become an important diagnostic tool in complement with histopathological methods, and advances epidemiological studies on the origin and distribution of Megalocytivirus in mariculture.

• 한국어병학회지
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• 제36권2호
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• pp.229-238
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• 2023

In this study, the correlation between clinical changes and RSIV genome copy number was investigated to determine the quantitative criteria for the characteristics of RSIV infection. The rock bream (Oplegnathus fasciatus) was intraperitoneally injected with three different doses (1.0×10¹, 1.0×10³ and 1.0×10⁵ viral genome copies/fish) as low, medium, and high doses, respectively. The clinical signs (spleen enlargement, death) observation and real-time PCR were conducted at 5, 10 and 14 days post-injection. During the experiment, spleen index as a quantitative indicator for spleen enlargement was continuously increased in the medium- (up to 2.26) and high-dose (up to 4.99) challenge groups, respectively. Notably, when the spleen index was over 1.5, 2.0, 2.5 and 3.0, a positive correlation was revealed with average viral genome copy numbers of 2.51, 3.37, 4.97 and 5.43×10⁷ viral genome copies/mg, respectively. Moreover, the threshold of spleen index over 1.5 was 1.0×10⁶ viral genome copies/mg, while the thresholds of spleen index over 2.0 and dead was 2.51×10⁷ viral genome copies/mg and the thresholds of spleen index over 2.5 and 3 was 3.98×10⁷ viral genome copies/mg. These findings suggest the possibility of quantitatively analyzing the characteristics and development process of RSIV infection.