• 한국수산과학회지
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• 제48권3호
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• pp.322-328
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• 2015

Three feeding trials were conducted to investigate the optimal feeding rates of subadult Korean rockfish Sebastes schlegeli at low, optimal and high water temperatures. In Exp-I, triplicate groups of fish (248 g) were fed a commercial diet (CD) with five different feeding rates of 0.1%, 0.2%, 0.4%, 0.6% and 0.8% body weight per day for 10 weeks at the low temperature ($11.6-15.2^{\circ}C$). In Exp-II, fish (129 g) were fed the same CD with five different feeding rates of 0.4%, 0.8%, 1.2%, 1.6% and 2.0% body weight per day for 10 weeks at the optimal temperature ($16.0-18.8^{\circ}C$). In Exp-III, fish (85.7 g) were fed the same CD with five different feeding rates of 0.4%, 0.8%, 1.2%, 1.6% and 2.0% body weight per day for 12 weeks at the high temperature ($21.0-28.5^{\circ}C$). The optimal feeding rates in the low, optimal, and high water temperatures were estimated to be 0.56%, 0.93% and 1.17% body weight per day, respectively, for subadult Korean rockfish.

• 한국수산과학회지
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• 제46권3호
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• pp.282-286
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• 2013

This study was conducted to compare extruded pellets (EP) and soft extruded pellets (SEP) with a raw fish-based moist pellet (MP) diet on the growth and flesh quality of Korean rockfish Sebastes schlegeli. Three groups of 20,000 fish (initial mean weight 133 g) per net-cage ($6{\times}12{\times}7m$) were fed commercial EP, SEP or MP for 16 months. The survival of fish fed SEP was higher than those of fish fed EP or MP. The highest growth performances were observed in the mean weight gain, total weight gain, and feed efficiency of fish fed MP, followed by those fed EP and SEP. Among the fish fed on extruded pellets, the total weight gain of fish fed SEP was higher than that of those fed EP, while fish fed EP grew faster than those fed SEP. No notable differences in body composition, sensory scores or textural properties of the dorsal muscle were observed in fish fed on EP, SEP or MP. Thus, it is suggested that extruded pellets, rather than raw fish-based moist pellets, could be fed to Korean rockfish without compromising flesh quality.

• 한국수산과학회지
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• 제54권5호
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• pp.617-623
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• 2021

The study was conducted to investigate the dietary supplementation of citrus by-product (CBP) and CBP fermented with Bacillus subtilis (BS) or B. pumilus (BP) on growth performance, feed utilization, innate immune responses and disease resistance of Korean rockfish Sebastes schlegelii. Triplicate groups of juvenile fish (initial weight of 22.9 g) were fed one of five experimental diets which were formulated to replace a synthetic vitamin C (L-ascorbyl-2-polyphosphate, LAPP) with CBP or fermented CBP. A basal diet without LAPP and CBP was used as the control diet (Con). At the end of the 13 weeks feeding trial, growth performance, feed utilization and survival of fish fed the Con were significantly lower than those of fish fed the LAPP, CBP and fermented CBP diets. Fish fed the Con were significantly lower in lysozyme activity than fish fed LAPP, CBP and fermented CBP diets. In a challenge test against Edwardsiella tarda, cumulative mortality of fish fed LAPP, CBP and fermented CBP diets was significantly lower (20-30%) than that of the Con (60%). The findings in this study indicate that the CBP and/or fermented CBP can be a promising vitamin C source for LAPP replacement in diet for Korean rockfish.

• 한국수산과학회지
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• 제52권4호
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• pp.358-365
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• 2019

This study investigated the effects of dietary cactus Opuntia ficus-indica stem and fruit extract on the growth, flesh quality, lysozyme activity, and histological changes of growing Korean rockfish Sebastes schlegeli. Three replicates of fish (152 g/fish) were fed one of the following diets: containing 0 additions (control); 0.1, 0.5, or 1.0% cactus stem powder; or 1.0% fruit extract for 11 weeks. Growth performance did not differ significantly among treatments, including survival, final weight, feed efficiency, and daily feed intake. The experimental diets did not affect the proximate and fatty acid compositions, plasma biochemistry, or dorsal muscle texture of the fish. However, the plasma lysozyme activity of the fish fed the diet containing 0.1% cactus stem was significantly higher than that of the fish fed the control diet. These fish had variously sized lipid vacuoles in the liver tissue compared with the control. Distinct mucosal folds and mucus-secreting goblet cells developed in the fish fed the diet containing 1% cactus stem compared with the other dietary groups. These results suggest that feeding growing Korean rockfish cactus stem might increase the plasma lysozyme activity and induce histological changes in the gastrointestinal tract that might be related to digestion.

• 한국어류학회지
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• 제20권3호
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• pp.149-155
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• 2008

The effects of noise stress response on hematological parameters (hemoglobin, hematocrit and MCHC) and plasma parameters (cortisol, glucose and albumin) in Korean rockfish (Sebastes schlegeli), a very important commercial marine fish in Korea, were investigated. These parameters were analyzed on fish exposed to an explosion of noise. There were no significant differences or trends in hematological parameters (hematocrit; control $29.7{\pm}4.8%$, experiment 32.0 35.5%; hemoglobin; control $6.5{\pm}0.7g/dL$, experiment 6.2 7.8 g/dL; MCHC; control $19.6{\pm}0.6g/dL$, experiment 19.9~22.2 g/dL). However, plasma cortisol and glucose exhibited significant differences from start to finish and displayed the following patterns (cortisol; control $180.7{\pm}35.4ng/mL$, experiment 247.0 444.5 ng/mL; glucose; control $32.5{\pm}6.3mg/dL$, experiment 50.5 109.0 mg/dL). In addition, the glucocorticoid receptor (GR) mRNA expression and basal levels of various tissues (eye, gills, liver, intestine, skin and gonads) were investigated for the first time in this marine fish. When the Korean rockfish was exposed to explosive noise stress, the GR mRNA was expressed more in the gonads than in other tissues tested and was elevated significantly from two and four times in the liver and gills, respectively, after noise exposure.

• 한국양식학회지
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• 제21권2호
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• pp.107-110
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• 2008

본 연구에서는 육성기 조피볼락 사육용으로 부상배합사료의 효과를 조사하기 위하여 평균 체중 112 g의 조피볼락을 8개월간 사육하였다. 실험사료로 4종류의 부상배합사료를 준비하여 1일 1회 만복으로 공급하였다. 사육실험 결과, 생존률은 모든 실험구에서 100%로 양호하였다. 성장률, 사료효율, 단백질효율, 사료섭취율 및 간중량지수 모두 각 실험구간에 유의한 차이가 없었다. 사육실험 종료시, 전어체와 간의 일반성분도 모든 실험구간에 차이가 없었다. 이상의 결과로 볼 때, 본 연구에 사용된 실험사료 조성은 육성기 조피볼락 양식을 위한 실용사료의 조성으로 사용하여도 좋을 것으로 판단된다.

• 수산해양교육연구
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• 제26권4호
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• pp.695-704
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• 2014

조피볼락 친어 3개 그룹(서해자연산, 서해가두리양식산, 동해자연산)과 치어 5개 그룹(서해자연산, 서해육산양식산, 서해육상 가두리양식산, 서해 축제식 가두리양식산, 서해축제식양식산)에 대하여 사육방법과 크기의 차이에 따라서 9개의 혈청 화학성분이 어떠한 변화를 나타내는지 알아보고자 하였다. 그 결과, 7개 항목인 총단백, 알부민, 총콜레스테롤, AST, ALT, LDH, ALP의 함량에서 친어 및 치어그룹 간에 유의적인 차이가 관찰되었다. 즉, 총단백, 알부민, 총콜레스테롤, ALP는 친어그룹이 치어그룹에 비해 높은 농도를 보였으며, 반대로 AST, ALT, LDH는 치어그룹이 친어그룹에 비하여 높은 농도를 나타내었다. 이러한 결과는 사육방법과 크기(친어, 치어)가 서로 다른 조피볼락의 생리적인 변화와 관련이 있는 것으로 판단된다.

• 한국수산과학회지
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• 제31권5호
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• pp.774-778
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• 1998

동물성장인자인 insulin-like growth factor-I (IGF-I)이 조피볼락의 성장 및 혈액중에 존재하는 IGF binding proteins (IGFBPs)에 미치는 영향을 검토하기 위하여 human recombinant IGF-I을 투여하여 분석한 결과, 절식중의 조피볼락 체중은 IGF-I 투여군이 생리식염수만 투여한 대조군 보다 체중 증가효과가 있었으며, 혈액중 glucose농도는 IGF-I의 투여군이 혈당저하효과를 나타내었다. 그리고 혈액중 IGFBP-3는 IGF-I투여군에서 증가하였으며, IGFBP-1은 감소하였다.

• 한국수산과학회지
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• 제51권4호
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• pp.411-419
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• 2018

This study investigated the survival rates and physiological responses of Korean rockfish, Sebastes schlegeli, in live fish containers ($8^{\circ}C$, 33 psu) for 18 days. The survival rate was 99% and 97% in the control and experimental groups, respectively. Hematocrit and hemoglobin did not differ significantly between the control and experimental groups. Glucose and cortisol rose immediately on the first day of containment, but both gradually normalized. Aspartate aminotransferase and alanine aminotransferase did not differ significantly between the two groups after recovery. $NH_3$ continued to rise after the first day, but decreased to a level not significantly different from that of the control group during the recovery period. Plasma ions and osmolality did not change abnormally. The hemocyte population was not significantly different from that of the control. The ratios of apoptotic and necrotic cells indicated no specific variation in hemocyte viability. The histological changes in the skin and gills were not significantly different from those seen in the control. The experimental data obtained in this study suggest that live fish containers may be used to transport Korean rockfish without significantly affecting their physiology or survival.

• 수산해양교육연구
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• 제28권3호
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• pp.692-700
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• 2016

넙치($700{\pm}50g$, $23{\pm}1.5^{\circ}C$) 및 조피볼락($500{\pm}30g$, $23{\pm}1.5^{\circ}C$)에게 Thiamphenicol(TP)을 1일 1회 경구(100 mg/kg BW) 투여한 다음, 경시적(1시간~432시간)으로 혈청 내 TP의 잔류량을 HPLC로써 분석하였다. TP를 어류 혈청에 0.1, 1.0, $10{\mu}g/mL$으로 첨가한 각각의 농도에 대하여 넙치 및 조피볼락에서 TP의 평균 회수율은 77.05~97.23%와 89.96~97.11%로 나타났다. TP의 경구 투여에 따른 넙치와 조피볼락의 체내 약물 혈중농도는 two-compartment model로 조사되었다. TP를 투여 후 넙치 혈청에서 10시간째 $10.08{\mu}g/mL$와 15시간째 $10.06{\mu}g/mL$로 최대값을 보였고, 조피볼락 혈청에서는 15시간째 $8.88{\mu}g/mL$로 최대값을 나타내었다. 넙치와 조피볼락의 혈청에서 TP는 투여 후 432시간째(18일째) 모든 시료에서 검출한계 이하로 검출되지 않았다. TP의 어류 체내 잔류 양상은 넙치와 조피볼락에서 매우 유사하였다. 본 연구에서 얻어진 결과는 넙치와 조피볼락에 TP를 처방하여 치료 계획을 수립할 때 유용하게 활용될 것으로 여겨진다.