• Fisheries and Aquatic Sciences
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• 제22권7호
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• pp.14.1-14.8
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• 2019

Olive flounder (Paralichthys olivaceus) is the major species developed for aquaculture in South Korea. Over the long history of olive flounder aquaculture, complex and diverse diseases have been a major problem, negatively impacting industrial production. Vibriosis is a prolific disease which continuously damages olive flounder aquaculture. A bacterial disease survey was performed from January to June 2017 on 20 olive flounder farms on Jeju Island. A total of 1710 fish were sampled, and bacteria from the external and internal organs of 560 fish were collected. Bacterial strains were identified using 16 s rRNA sequencing. Twenty-seven species and 184 strains of Vibrio were isolated during this survey, and phylogenetic analysis was performed. Bacterial isolates were investigated for the distribution of pathogenic and non-pathogenic species, as well as bacterial presence in tested organs was characterized. V. gigantis and V. scophthalmi were the dominant non-pathogenic and pathogenic strains isolated during this survey, respectively. This study provides data on specific Vibrio spp. isolated from cultured olive flounder in an effort to provide direction for future research and inform aquaculture management practices.

• Fisheries and Aquatic Sciences
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• 제2권2호
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• pp.161-166
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• 1999

The rigor-mortis progress of cultured olive flounder spiked at the brain started much faster than that of wild one. They attained full rigor state after 30 hrs at $0^{\circ}C$, 36 hrs at $5^{\circ}C$ and 50 hrs at $10^{\circ}C$ in the cultured flounder, while after 36 hrs at $0^{\circ}C$, 50 hrs at $5^{\circ}C$, and 60 hrs at $10^{\circ}C$ in the wild. ATP concentration in the muscle was around $5.9\mu mol/g$ for wild and $6.2\mu mol/g$ for cultured flounder. ATP breakdown progressed rapidly in $0^{\circ}C$ samples, followed by $5^{\circ}C$ and $10^{\circ}C$ samples. $Mg^{2+}$-ATPase activity of myofibrillar protein in the presence of 0.25mM CaCb was higher in cultured myofibri1lar protein than in wild one. $Mg^{2+}$-ATPase activities of myofibrillar protein increased during storage in samples stored at $0^{\circ}C$ and $5^{\circ}C$ while decreased in samples stored at $10^{\circ}C$. The level of breaking strength of muscle immediately after death was higher in the wild muscle than in the cultured muscle. The breaking strength reached maximum level at 10 hrs after death in both samples.

• Parasites, Hosts and Diseases
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• 제57권4호
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• pp.439-444
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• 2019

Since Kudoa septempuntata was identified as a causative agent of food poisoning associated with raw olive flounder Paralichthys olivaceus, interest and concern regarding the parasite have increased. However, there have been no investigations or reports of other Kudoa species infecting the fish (except for K. paralichthys, which infects the brain) in Korea. We found cysts filled with myxospores of Kudoa species in muscles of cultured olive flounder specimens and identified these to the species level. Mature spores were quadrate, measuring $8.7{\pm}0.5{\mu}m$ in length, $9.2{\pm}0.4{\mu}m$ in thickness, and $12.9{\pm}0.6{\mu}m$ in width. The spores containing 4 polar capsules had a length of $2.1{\pm}0.2{\mu}m$ and a width of $1.8{\pm}0.3{\mu}m$. The partial 18S and 28S rDNA of isolates showed 99-100% similarities with K. ogawai. Using these morphological and molecular analyses, the species was identified as K. ogawai. This study is the first report of K. ogawai infection in cultured olive flounder in Korea.

• 한국수산과학회지
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• 제47권5호
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• pp.611-621
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• 2014

A nationwide survey was conducted to study the rate of Kudoa septempunctata parasitization in cultured olive flounder, Paralichthys olivaceus, in Korea in 2013. Of 1107 olive flounder sampled randomly from 89 culture farms in five different regions in Korea, K. septempunctata was detected only in Jeju, where 10 of 318 fish (3.14%) were PCR positive, with genomic concentrations of $4.67{\times}10^5$ to $1.48{\times}10^{11}$ rDNA copies/g by real-time PCR. Of the ten Kudoapositive fish, K. septempunctata spores with 5-7 polar capsules were detected only in four fish. No samples of K. septempunctata were detected in olive flounder from the other regions surveyed. Furthermore, K. septempunctata was not detected in 326 samples of olive flounder seeds sampled from 39 hatcheries in seven different regions in Korea. Therefore, the parasite infection is restricted to Jeju and K. septempunctata infection is not spread from hatcheries.

• 한국발생생물학회지:발생과생식
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• 제14권2호
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• pp.131-141
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• 2010

이 연구는 양식산 넙치의 성장단계별 및 계절에 따른 생리학적 반응과 혈액학적 요소들을 파악하고자 하였으며, 분석된 항목으로는 hematocrit, red blood cell, hemoglobin, 글루코스, 콜레스테롤, 총단백질, AST, ALT, $Na^+,\;K^+,\;Cl^-,\;Ca^{2+},\;Mg^{2+}$, osmolality, 코티졸 및 $T_3$였다. 성장단계별 혈액학적 성상에 있어 $T_3$는 어류의 크기가 클수록 증가하는 경향을 나타내었다. 반면, 콜레스테롤은 어체의 크기가 클수록 감소하는 경향을 보였다. 계절별 혈액학적 성상에 있어 Ht와 RBC는 가을에 가장 높은 수준을 나타냈다. 코티졸은 모든 그룹에서 $2.2{\pm}0.4{\sim}4.3{\pm}1.9ng/m{\ell}$의 농도를 보였다. 나머지 혈액학적 요소는 성장단계별, 계절별로 특이한 차이를 나타내지 않았다. 본 연구에서 분석 비교한 각종 혈액학적 요소의 측정값은 양식산 넙치의 생리활성 평가에 활용될 수 있을 것으로 기대된다.

• 한국식품저장유통학회지
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• 제18권5호
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• pp.746-754
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• 2011

배합사료를 공급한 양식 넙치와 생사료를 공급한 양식넙치의 핵산 관련 물질 및 유리아미노산 측정을 통한 품질의 차이를 비교하였다. 넙치 등근육의 핵산관련물질은 모든 실험사료구에서 공통적으로 AMP 함량이 가장 높았고 그 다음으로 IMP의 함량이 높았다. 공급한 사료에 따라서 HxR의 성분에는 유의적인 차이(p<0.05)를 보였으나, 핵산 관련물질 조성의 분포양상은 비슷한 경향을 나타내었다. 또한, 넙치 지느러미살의 핵산 관련 물질 조성 중 공급한 사료의 종류에 상관없이 IMP 함량이 공통적으로 가장 높게 나타났으나 함량에는 유의적인 차이를 보이지 않았다. 한편, 어육의 초기 변화 정도를 측정하는 K value는 넙치 등근육에서 MP, CEP 및 FEP의 공급구가 각각 9.63%, 9.83% 및 5.84%를 나타내었고, 넙치 지느러미 살에서는 각각 15.71%, 11.22% 및 17.60%를 나타내었다. 넙치를 사육하는 동안 공급하는 사료의 종류에 따라 등 근육 및 지느러미살의 특정 유리아미노산 함량에는 유의적인 차이가 있으나, 전반전인 유리아미노산의 조성에는 큰 차이가 없었다. 유리아미노산 중에서 taurine 함량이 모든 실험사료구에서 공통적으로 가장 높았고, CEP 및 FEP 공급구는 asparagine과 citrulline의 함량이 MP 공급구보다 높았다. 이처럼, 넙치를 사육하는 동안 공급하는 사료의 종류에 따라 등근육 및 지느러미살의 특정 유리아미노산의 함량에 차이가 나는 것으로 볼 때, 맛과 풍미에 큰 영향을 미치는 유리아미노산 조성의 규명은 기호도를 예측할 수 있는 효과적인 방법이라 생각된다.

• 한국어병학회지
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• 제35권1호
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• pp.57-63
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• 2022

Vibrio parahaemolyticus와 V. vulnificus 같은 인체 위해성 세균들은 수산물을 통하여 인체에 감염되는 것으로 알려져 있음으로 생선회로 선호도가 높은 넙치에서 이들 세균이 어느 정도 생존 가능한지 알아보고자 하였다. 먼저 온도와 염분 농도가 다른 배지에서 이들 세균의 생장도를 조사하였다. 37℃ 에서 보다 25℃에서 V. parahaemolyticus와 V. vulnificus는 약 50~60% 감소한 생장률을 보였다. 그러나 1%, 2% 및 3% NaCl을 함유한 배지로 25℃에서 배양하였을 때의 생장은 3% NaCl을 함유한 배지에서 V. vulnificus가 증가된 생장을 보인 것을 제외하고 차이는 없었다. V. parahaemolyticus와 V. vulnificus에 대한 넙치의 감수성을 알아보기 위하여 1×10⁶CFU/fish로 복강 주사하여 인위 감염을 하였으나 1주일간 사망 개체는 없었다. V. parahaemolyticus와 V. vulnificus에 대한 넙치의 방어능력을 알아보기 위하여 넙치의 혈청 및 체표 점액에서의 세균 생존력과 신장에서 분리한 macrophage의 식균 활성을 알아보았다. 혈청에서는 3시간 이내에 각각 85%, 99% 이상의 균이 제거되었고 체표 점액에서는 12시간까지 세균 수가 감소하였으며 신장백혈구는 약 70% 이상에서 식균 작용을 나타냈다. 따라서 넙치는 환경 수에 있는 V. parahaemolyticus와 V. vulnificus에 대한 단순 이동매개체로 작용한다 할지라도 발달된 자체 항균력으로 이들 세균의 수를 감소시켜 인체 감염 가능성을 저하하는 효과가 있음을 시사하였다.

• 한국어병학회지
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• 제16권1호
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• pp.51-59
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• 2003

Streptococcal infection is one of the most serious disease of cultured olive flounder, Paralychthys olivaceus in Korea and caused by more than one species. However, there has been considerable confusions about the taxonomic position of the fish pathogenic streptococci. In this study, We performed the randomly amplified polymorphic DNA(RAPD) pattern analysis to evaluate the possible classification in 8 streptococci isolated from diseased olive flounder and reference strains based on their DNA structure. RAPD PCR with DNA solution prepared by simple boiling and 10-mer random primer was appeared to be a good tool for discrimination of different streptococcal strains. Phenotypical characters by simple biological test and API 20 Strep corresponded well to the specific profiles of RAPD in streptococcal isolates of this study. Therefore, the RAPD profile was considered as one of differential characters to discriminate the streptococcal isolates from diseased olive flounder.

• 한국수산과학회지
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• 제40권3호
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• pp.128-132
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• 2007

We identified a microsatellite marker, Poli121TUF, which appears to be significantly linked (P<0.001) with a lymphocystis disease virus (LCDV)-resistance gene in the olive flounder, Paralichthys olivaceus. The olive flounder is an economically important food fish, that is widely cultured in Korea, Japan, and China. Lymphocystis disease has spread in these countries and has seriously reduced the economic value of the fish. LCDV causes lymphocystis cells (LC) to form on the body surface, fins, gills, mouth, and intestine. Fish with LC lose commercial value due to their deformed appearance. The identified micro satellite marker can be used as a candidate locus for marker-assisted selection (MAS) in order to enhance the efficiency of selection for LCDV resistance in the olive flounder.

• 대한수의학회지
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• 제47권3호
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• pp.299-302
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• 2007

Neoheterobothrium hirame (N. hirame) is a large blood-feed gill-worm infecting the highly prized olive flounder. The present study was reported the occurrence and elimination of Neoheterobothrium infection from young cultured oliver flounder in the western coast of Korea. Flounder (weight 18-25 g, length 10-15 cm) were obtained from a cultured farm at Taean of Korea at May 2006. A lot of flounder died with serious anemia. We isolated N. hirame from the buccal cavity wall of dead flounder. Adult parasites were 5-15 mm in total length, with 4 pairs of clamps on the pedunculated haptor and isthmus region embedded in host tissue, while immature and sub-adults were identified the attachment to the gill filaments, rakers and arches with the clamps. All fish with infection were treated with 8% NaCl-supplemented seawater for 1 and 10 min at $22^{\circ}C$, respectively. The significant reduction in mortality (6.7%) was observed among fish treated with 8% salt water for 10 minutes, when compared with that of non-treatment group (100%).