• 한국수산과학회지
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• 제43권6호
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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.

• 한국어병학회지
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• 제12권1호
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• pp.63-65
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• 1999

남해안에 서식하는 넙치의 장에서 이생흡충류에 속하는 Pseudolepidapedon kobayashii 1종을 국내에서 처음 기록하였으며, 넙치는 이 기생충의 새로운 종숙주로 밝혀졌다. 본 논문에서는 P. kobayashii의 형태학적 특징들을 기술하였고 같은 속내의 다른 종들과 형태학적 차이점을 비교하였다.

• 한국식품조리과학회지
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• 제19권1호
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• pp.72-78
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• 2003

This study was conducted to investigate the physicochemical and organoleptic characteristics and freshness of wild and cultivated Paralichthys olivaceus during storage. By the results of morphological observation, wild Paralichthys olivaceus had white abdomen, light black skin and transparent muscle, but cultivated Paralichthys olivaceus had black spotted abdomen, dark black skin and dark pink muscle. Moisture contents of wild and cultivated Paralichthys olivaceus were similar, but the lipid content was higher in cultivated Paralichthys olivaceus than that of wild Paralichthys olivaceus. Sensory scores of appearance, taste, texture and overall acceptability were higher in wild Paralichthys olivaceus than that of cultivated Paralichthys olivaceus. The reason was that lipid content was higher in cultivated Paralichthys olivaceus The freshness of cultivated Paralichthys olivaceus seemed to last shorter than that of wild one due to rapid increase of the volatile basic nitrogen content, pH and total microbial count during storage.

• 한국발생생물학회지:발생과생식
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• 제24권1호
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• pp.19-30
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• 2020

The pH of water is one of the main environmental factors exerting selective pressure on marine and freshwater organisms. Here, we focus on the influence of pH on an organism's ability to maintain homeostasis and investigate the effects of acidification on immunity-related genes and osmotic pressure during early development of the olive flounder, Paralichthys olivaceus. The aim of our study was to determine the influence of various pH levels on the fertilized eggs and larvae of P. olivaceus. Gametes of P. olivaceus were artificially introduced and the resulting fertilized eggs were incubated at pH 4.0 (low), 6.0, and 8.0 (equivalent to natural sea water; control). We found that all eggs sank from the water column at pH 4.0. After 38 h, these eggs showed slow development. Hatching occurred more slowly at pH 4.0 and 6.0 and did not occur at all at pH 4.0. Result of gene expression, caspase and galectin-1 were expressed from the blastula to pre-hatch stages, with the exception of the two-cell stage. HSP 70 was also steadily expressed at all pH levels over the five days. The osmolality of fertilized eggs differed marginally at each stage and across pH levels. So, this results demonstrates that low pH level is detrimental to P. olivaceus fertilized eggs.

• 한국수산과학회지
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• 제44권6호
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• pp.684-688
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• 2011

The feeding habits of Paralichthys olivaceus in the Uljin marine ranching area, located on the mid-eastern coast of Korea, were studied from January to November 2009. In total, 381 specimens were collected; fish ranged in size from 15.4 to 59.0 cm in total length. P. olivaceus is a carnivore, mainly consuming other fishes and crustaceans. The prey items of P. olivaceus changed ontogenetically. Small individuals fed on decapod crustaceans while large ones fed heavily on other fishes. The diet of P. olivaceus varied seasonally. Fish comprised the main prey items throughout the year. The stomach contents index (SCI) of each size class increased and the dietary breadth index (DBI) of each size class decreased as individuals grew.

• 한국발생생물학회지:발생과생식
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• 제16권1호
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• pp.9-18
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• 2012

The effects of the estrogenic compound 4-nonylphenol (4-NP) on vitellogenesis in juvenile olive flounder ($Paralichthys$ $olivaceus$) and rockfish ($Sebastes$ $schlegeli$) exposed continuously at 10, 50 and $100{\mu}g{\ell}^{-1}$ levels for 7 days were compared. The expression of VTG mRNA level and protein using specific probes were examined. The levels of plasma estradiol-17 ${\beta}(E_2)$ and testosterone (T) were assessed by radioimmunoassay (RIA). Plasma $E_2$ concentrations increased significantly in two female fish species exposed to $100{\mu}g{\ell}^{-1}$ of 4-NP over concentrations in control fish. Plasma T concentrations increased in $P.$ $olivaceus$. Four days after exposure, the level of VTG mRNA expression increased in $P.$ $olivaceus$ and $S.$ $schlegeli$ exposed to $20{\mu}g{\ell}^{-1}$ of 4-NP. In addition, plasma VTG protein expression was seen in $P.$ $olivaceus$ and $S.$ $schlegeli$. In $S.$ $schlegeli$ and $P.$ $olivaceus$ exposed to 4-NP, the changes were noticed mainly in hepatocytic vaculation after 7 days of exposure. Thus, 4-NP may disrupt vitellogenesis in immature fish both directly and indirectly via disrupted steroidogenesis and liver pathology. Immature $S.$ $schlegeli$ were the most sensitive to 4-NP exposure in vitellogenesis.

• 한국수산과학회지
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• 제53권5호
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• pp.733-739
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• 2020

Olive flounder Paralichthys olivaceus (total weight 216.4±14.6 g, total length 28.4±1.7 cm) were exposed to different pH levels (3, 4, 5, 6, 7, 8, and 9) for 96 h. At pH 4, hemoglobin decreased significantly, while plasma calcium, glucose, cholesterol, and ALP increased significantly. Exposure to pH 4 also induced stress responses, as evidenced by a significant decrease in heat shock protein 70 (HSP 70) and a significant increase in cortisol. The results of this study indicate that acute exposure to acidic or alkaline pH (pH 3 or 9) induced significant mortality, while exposure to pH 4significantly affected hematological parameters and stress responses in P. olivaceus.

• Fisheries and Aquatic Sciences
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• 제8권3호
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• pp.132-137
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• 2005

Olive flounder (Paralichthys olivaceus) is one of the most commercially important species of farmed marine fish in Korea. Although techniques for rearing the larva of this species are improving, production costs are also increasing due to microbial influences and genetic degradation caused by successive culturing. Since the demand for healthy seed, which requires eggs of good quality of, is high, we examined the effects of nutrient composition on the size of P. olivaceus eggs. We analyzed floating (live) and sunken (dead) eggs of P. olivaceus from five different hatcheries for their size and amino and fatty acid composition. The sizes of eggs and oil globules from floating vs. sunken eggs were significantly different at p<0.05. No significant relationships were observed, however, among larval length, hatching percentage, and egg and oil globule size. The dry weight and amino acid levels of floating eggs were greater than those of sunken eggs (p<0.05), but no difference in fatty acid content was observed.

• 환경생물
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• 제30권3호
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• pp.238-244
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• 2012

넙치, Paralichthys olivaceus 수정란의 부화율을 이용하여 중금속(Pb, Cr, As)의 독성 영향을 조사하였다. Pb, Cr, 및 As (0, 10, 100, 500, 1,000, 2,500, 5,000 ppb)에 수정란을 48 h 노출시킨 후, 정상 부화율을 백분율로 나타내었다. 중금속을 포함하지 않는 대조구에서는 정상 부화율이 80% 이상을 나타냈으나, 중금속 농도가 증가할수록 정상 부화율은 급격히 감소하였다. 정상 부화율은 Pb, Cr, 및 As에 대해 농도 의존적으로 감소하였으며, 각각 100, 100, 500 ppb 이상의 농도에서 유의한 차이를 나타내었다. P. olivaceus의 정상 부화율에 대한 Pb, Cr 및 As의 반수 영향농도($EC_{50}$)를 이용한 독성은 Cr>As>Pb 순으로 나타났다. Pb와 As의 NOEC와 LOEC 각각 100 ppb와 500 ppb로 유사한 값을 나타냈으며, Cr에 대한 NOEC는 10 ppb, LOEC는 100 ppb를 나타내었다. 이들 결과로부터 자연생태계 내에서 Pb과 As의 농도는 100 ppb, Cr 농도는 10 ppb를 초과할 경우 P. olivaceus 수정란의 정상 부화율은 독성 영향이 나타날 것으로 판단된다. 본 연구 결과를 바탕으로, P. olivaceus의 정상 부화율을 이용한 생물학적 평가방법은 중금속과 같은 유해물질에 대한 해양생태계의 영향을 판단하기 위한 시험방법으로 유용하게 이용될 수 있을 것으로 판단된다.

• 환경생물
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• 제30권2호
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• pp.136-142
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• 2012

넙치(Paralichthys olivaceus) 수정란의 부화율에 대한 중금속(Cd, Cu, Zn)의 급성독성을 조사하였다. Cd, Cu 및 Zn (0, 10, 100, 500, 1000, 2500, 5000 ppb)에 수정란을 48 h 노출시킨 후, 정상 부화율을 백분율로 나타내었다. Cd, Cu 및 Zn을 포함하지 않는 대조구에서는 정상 부화율이 80% 이상을 나타냈으나, 중금속 농도가 증가할수록 정상 부화율은 급격히 감소하였다. 정상 부화율은 Cd, Cu 및 Zn에 대해 농도 의존적으로 감소하였으며, 각각 1000, 100, 100 ppb 이상의 농도에서 유의적이 차이를 나타내었다. P. olivaceus의 정상 부화율에 대한 Cd, Cu 및 Zn의 반수영향농도($EC_{50}$)를 이용한 독성은 Zn>Cu>Cd 순으로 강한 것으로 나타났으며, 이들 중금속에 대한 $EC_{50}$는 각각 584, 1015, 1282 ppb를 나타내었다. Cd에 대한 NOEC는 500 ppb를 나타냈고 LOEC는 500 ppb를 나타내었다. Cu와 Zn의 NOEC와 LOEC 각각 100 ppb와 500 ppb로 유사한 값을 나타내었다. NOEC와 LOEC 결과로부터 자연생태계 내에서 Cu와 Zn 농도는 100 ppb, Cd 농도는 500 ppb를 초과할 경우 P. olivaceus 수정란의 정상 부화율은 감소할 것으로 판단된다. 본 연구결과를 바탕으로, P. olivaceus의 정상 부화율을 이용한 생물학적 시험은 중금속과 같은 유해물질에 대한 해양생태계의 영향을 판단하기 위한 시험방법으로 유용하게 이용될 수 있을 것으로 판단된다.