• 한국수산과학회지
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• 제50권5호
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• pp.547-552
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• 2017

The viral hemorrhagic septicemia virus (VHSV) has an extensive host range, and infects farmed and wild fish inhabiting both freshwater and marine ecosystems. Enzyme-linked immunosorbent assay (ELISA) is highly useful in diagnosing viral hemorrhagic septicemia. However, ELISA shows high, non-specific background reaction with fish antibodies. In this study, we optimized the antigen and antibody concentrations used for detecting specific antibodies in VHSV-infected olive flounder to reduce non-specific binding, and improve the sensitivity of ELISA. The results suggested that OD (optical Density) values were valid when ELISA was performed with $0.1{\mu}g/well$ of virus, involving blocking with blocking buffer (Roth, Roti-Block), 1:300-1:600 dilution with flounder antisera, and 1:1000 dilution with anti-flounder IgM and HRP-conjugated goat anti-mouse IgG for detecting the VHSV antibody in flounder sera. Furthermore, 11 different VHSV strains isolated in Korea from 2012 to 2016 were used to infect the fish. The results showed no correlation between viral pathogenicity and antibody production. This research is a basic study on the application of antibody detection in the diagnosis of viral hemorrhagic septicemia in the olive flounder.

• 스마트미디어저널
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• 제11권4호
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• pp.62-68
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• 2022

수산 양식장 질병 감염의 확산을 사전에 차단을 위해서는 양식장의 수질 환경 및 생육 어류의 상태를 실시간 모니터링하면서 어류의 질병을 예측하는 시스템이 필요하다. 어류 질병 예측의 기존 연구는 이미지 처리 기법이 대부분이었으나 최근에는 딥러닝 기법을 통한 질병 예측방법의 연구가 활발히 진행되고 있다. 본 논문에서는 수산 양식장에서 발생할 수 있는 넙치의 질병을 딥러닝 기술로 예측하는 방법에 대한 연구결과를 소개하고자 한다. 이 방법은 양식장에서 수집된 카메라 영상에 데이터 증강과 전처리 포함하여 질병 인식률의 성능을 높인다. 이것을 통해 질병 어류를 조기 발견으로 양식 어업에서 어류 집단 폐사 등 어업 재해를 예방하고 지역 수산 양식장으로 어류의 질병 확산 피해를 줄여 매출액 감소 차단될 것으로 기대한다.

• 한국어병학회지
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• 제20권1호
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• pp.61-70
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• 2007

2004년 10월부터 2006년 8월까지 우리나라에서 양식되고 있는 넙치를 대상으로 세균성 질병의 발생률을 조사하기위한 역학조사를 실시하였다. 외관상 질병이 의심되는 개체를 포함하여 무작위로 총 1,271 마리를 채집하여 조사하였다. 검사개체중 738 마리에서 병원체에 감염되어 있었으며 이중 331 마리에서 366 균주가 검출되었다. 검출된 세균의 종류는 Vibrio spp. (42.1%), Streptococcus spp. (16.9%), Edwardsiella tarda (12.3%), Photobacterium damselae subsp. damselae (8.2%), Pseudomonas spp. (2.2%) 및 기타 (18.3%)로 나타났다. Vibrio spp. 및 P. damselae subsp. damselae는 연중 모든 계절에 검출되었으며 반면에 Streptococcus spp. 및 E. tarda는 주로 5월부터 검출되기 시작하여 11월까지 검출되었다. 검출된 세균 중에서 206건은 다른 세균 (3.6%), 기생충 (31.4%) 또는 바이러스 (41.7%)와 혼합감염 되어있었다; Vibrio spp. (n=21), Streptococcus spp. (n=13), Trichodina (n=76), Scutica (n=31), VNNV (n=112), VHSV (n=46).

• 한국어병학회지
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• 제32권1호
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• pp.29-35
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• 2019

2015년부터 2017년까지 우리나라 넙치 양식장에서 발생하는 폐사피해를 표본조사를 통해 모니터링 하였다. 표본어가는 전국의 수산질병관리원과 지속적으로 거래하고 있으며 현장방문을 통해 설문이 가능한 양식어가 중 층화구조분석을 통해 선정 하였다. 수산질병관리사 조사요원의 직접적인 현장방문을 통한 설문 조사를 수행하여 객관적으로 양식현황 및 폐사 현황을 파악하였다. 조사기간 중 24.78%/2015년, 30.19%/2016년 그리고 21.59%/2017년의 누적 폐사율을 나타내었고, 감염성 질병에 의한 폐사는 스쿠티카증(2015-2017년 평균 누적 폐사율: 56.7%)과 바이러스성출혈성 패혈증 감염(추정)(2015-2017년 평균 누적 폐사율: 8.9%)에 의한 피해가 높은 것으로 나타났으며, 제주에서는 여윔증(2016-2017년 평균 누적 폐사율: 10.3%)에 의한 피해가 높게 나타났다.

• 한국콘텐츠학회논문지
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• 제22권3호
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• pp.71-80
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• 2022

과거 양식장에서 어류 질병은 세균성이었던 반면 최근은 바이러스성 및 혼합된 형태가 되면서 어류 질병의 빈도가 높아졌다. 양식장이라는 밀폐된 공간에서 바이러성 질병은 확산속도가 높으므로 집단 폐사로 이어질 확률이 매우 높다. 집단 폐사를 방지하기 위해서는 어류 질병의 빠른 식별이 중요하다. 그러나 어류의 질병 진단은 고도의 전문지식이 필요하고 매번 어류의 상태를 눈으로 확인하기 어렵다. 질병의 확산을 막기 위해서는 병이든 어류의 자동식별 시스템이 필요하다. 본 논문에서는 딥러닝 기반의 넙치의 질병 식별 시스템의 성능을 높이기 위해서 기존 전처리 방법을 비교 실험한다. 대상 질병은 넙치에서 가장 빈번히 발생하는 3가지 질병 스쿠티카병, 비브리오증, 림포시스티스를 선정하였고 이미지 전처리 방법으로 RGB, HLS, HSV, LAB, LUV, XYZ, YCRCV를 사용하였다. 실험결과 일반적인 RGB를 사용하는 것보다 HLS가 가장 좋은 결과를 얻을 수 있었다. 간단한 방법으로 질병의 인식률을 향상해 어류 질병 식별 시스템을 고도화 할 수 있을 것으로 예상한다.

• 한국수산과학회지
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• 제41권4호
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• pp.248-252
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• 2008

A 6-week feeding trial was conducted to investigate effects of dietary supplementation with wood vinegar (WV) as a feed additive for juvenile olive flounder, Paralichthys olivaceus. Eight experimental diets supplemented with 0(control), 0.01, 0.025, 0.05, 0.1, 0.25, 0.5 and 2.0% WV/kg diet($WV_0,\;WV_{0.01},\;WV_{0.025},\;WV_{0.05},\;WV_{0.1},\;WV_{0.25},\;WV_{0.5},\;and\;WV_{2.0}$, respectively) were prepared by mixing with basal diet. After the 6-week feeding trial, fish fed the $WV_{0.1}$ diet had significantly higher weight gain, feed efficiency, and specific growth rate than those of fish fed the other diets(P<0.05). No mortality was observed in the treatment groups fed the experimental diets for 6 weeks. The liver antioxidant activity of fish fed the $WV_{0.01},\;WV_{0.025},\;and\;WV_{0.05}$ diets was significantly higher than that of fish fed the other diets. The lysozyme activity of fish fed the $WV_{0.25}$ diet was significantly higher than that of fish fed the other diets. Fish fed diets supplemented with WV had significantly lower cumulative mortality than that of fish fed the control diet throughout the challenge test, and fish fed the $WV_{0.05}\;and\;WV_{0.1}$ diets had the highest resistance to disease caused by Edwardsiella tarda at day 7 of the challenge test. Therefore, feeding 0.05-0.1% WV/kg diet improves the growth and immune responses of juvenile olive flounder, Paralichthys olivaceus.

• 한국수산과학회지
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• 제53권2호
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• pp.191-202
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• 2020

We evaluated the effects of dietary supplementation of phytosterol on the growth, feed utilization, immunity, digestibility, wound healing ability and disease resistance of olive flounder Paralichthys olivaceus. We conducted two consecutive feeding trials at different growth stages of the fish: EXP-1 (68.9 g) and EXP-2 (16.5 g). The experimental diets were supplemented with graded levels of phytosterol (1% ecdysteroid extracted from Achyranthis radix) at 0, 0.025, 0.05, 0.1, 0.2 and 0.4% (designated as Con, PHY0.025, PHY0.05, PHY0.1, PHY0.2 and PHY0.4, respectively). Dietary phytosterol did not significantly affect growth and cholesterol concentration. Feed utilization was higher in fish fed phytosterol-supplemented diets than in fish fed the control diet. Dietary phytosterol increased innate immunity and digestibility of protein and dry matter. Wound healing ability was also increased by the phytosterol supplementation. The survival against Edwardsiella tarda challenge was higher in fish fed low-phytosterol diets than in fish fed the control diet. The optimum dietary level of phytosterol seems to be approximately 0.05%. The results in this study indicate that the phytosterol could be used as a functional supplement in diets to improve feed utilization, immunity, digestibility and wound healing ability of olive flounder.

• 한국양식학회지
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• 제11권2호
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• pp.223-230
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• 1998

This study was carried out for the purpose of developing environmental friendly and effective chemical treatment method for the disease control in the land-based flounder culture which is industrially popular in the coastal area in Korean. The chemicals such as flounder, Paralichthys olivaceus and their effects on the fish based on the 24hr-$LC_{50}$, $LT_{50}$, 24-hour survival rate at each experimental concentration, recovery rate of the survived individual from chemical treatment, and the histological change of the gill after chemical treatment were investigated and analyzed. The 24hr-$LC_{50}$ was 321.65 ppm for formalin, 419.62 ppm for chlorine dioxide, and 395.97 ppm for hydrogen peroxide, respectively. The $LT_{50}$ was 15-hour for formalin, 17-hour for chlorine dioxide and 24-hour for hydrogen peroxide, respectively. Fishes exposed to the experimental concentration of three chemicals were quickly susceptible in the order of formalin, chlorine dioxide and hydrogen peroxide with a trend of shorter half lethal time at higher concentration. Initial survival rate of the flounder soon after chemical treatment was the highest in the hydrogen peroxide treatment compared with the other two chemicals. The histological damage by the hydrogen peroxide treatment was negligible compared with the other two chemicals. Accordingly, hydrogen peroxide treatment showed the lowest toxicity compared with the other two chemicals to the experimental fishes.

• 한국수산과학회지
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• 제39권2호
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• pp.72-77
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• 2006

Enrofloxacin (ENRO) is one of the most commonly used fluoroquinolones for treating bacterial disease in olive flounder (Paralichthys olivaceus) farming, but its withdrawal time for industrial-scale farming has not been well established. Withdrawal times of ENRO following oral administration were evaluated in olive flounder under field conditions. Fish were held in an inland fish tank and fed a commercial mediated diet containing 5 mg/kg of ENRO for 9 days. Seven fish per sampling point were examined during and after treatment. ENRO and its major metabolite, ciprofloxacin (CIP), were analyzed using high-performance liquid chromatography with a fluorescence detector. The concentration of ENRO and CIP in muscle increased during the medication period, and then decreased rapidly The sum of ENRO and CIP concentration in olive flounder peaked on day 6, with a maximal concentration in muscle of 4.30 mg/kg. ENRO residues were eliminated rapidly; at 10 days post treatment, the level in muscle was 0.10 mg/kg, but it took about 50 days to be reduced to below 0.1 mg/kg. After 60 days, the residual concentration was below 0.1 mg/kg in all samples. The level of ENRO accumulation at the beginning of oral administration was variable, according to the farming conditions, but the overall exhaustion time was almost the same. We concluded that an adequate withdrawal period of enrofloxacin is 60 days in the case of oral administration.

• 한국수산과학회지
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• 제44권6호
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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.