• 한국수산과학회지
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• 제53권4호
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• pp.479-485
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• 2020

We evaluated the hatchability of fertilized eggs from six hybrid combinations of highly valued grouper species inhabiting temperate and warm waters, with the goal of establishing a novel hybrid with enhanced growth and viability during the culturing period in the temperate waters of Korea. Hybrid combinations with red-spotted grouper females exhibited high hatchability with high a fertilization and hatching rate of fertilized eggs and a low deformity rate of hatched larvae. Conversely, hybrid combinations with kelp grouper females had very low hatching rates and very high deformity rates; commercial production of seed from such crosses would be difficult without improving hatchability. The hatchabilities of convict grouper ♀×giant grouper ♂ and kelp grouper ♀×red-spotted grouper ♂ were lower than those of maternal purebreds, but these two hybrid combinations were expected to produce potentially large quantities of hatched larvae. In the above evaluation, promising hybrid combinations were identified for commercial production of seed. For these hybrids to contribute to the development of Korea's mariculture industry, mass production of fertilized eggs and seeds is necessary, along with the development of advanced rearing techniques, such as the identification of a suitable rearing temperature.

• 한국수산과학회지
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• 제54권4호
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• pp.426-433
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• 2021

This study aimed to determine the appropriate salinity condition for optimal cultivation of the juvenile hybrid grouper Epinephleus akaara♀×E. lanceolatus♂ in conditions of decreasing salinity. The survival, growth, metabolic rate, stress, and histological response were investigated in juvenile hybrid grouper exposed to different salinities for 30 days. At 0 psu, the survival rate of the juvenile hybrid grouper was 60% on the 2nd day of exposure and all individuals died on the 3rd day of exposure. At salinities above 3 psu, all animals survived throughout the exposure period. Growth rate for body weight of the juvenile hybrid grouper was the highest in the control and the lowest at 10 psu. Plasma osmolality of the juvenile hybrid grouper exposed to different salinities was 313-355 mg Osmol/kg at salinities above 10 psu, and then decreased to 225-264 mg Osmol/kg at salinities below 5 psu. The oxygen consumption rate tended to decrease as the salinity decreased. Stress responses of the juvenile hybrid grouper were analyzed with decreasing salinity. Therefore, it is considered that a salinity of more than 20 psu is suitable for the culture of the juvenile hybrid grouper.

• 한국어류학회지
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• 제27권1호
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• pp.16-20
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• 2015

서식 환경이 다른 바리과(family Serranidae) 어류 두 종, 붉바리 (Epinephelus akaara)와 brown-marbled grouper (E. fuscoguttatus)의 종간 잡종 수정란의 부화율을 조사하였다. 잡종(붉바리 ♀ ${\times}$ brown marbled grouper ♂)의 수정 후 각 발생단계까지 소요시간은 붉바리 순종과 차이가 없었으며, 부화 소요시간은 $25^{\circ}C$에서 25.6시간이었다. 잡종은 붉바리 순종과는 달리 비균등 난할이 분명하게 관찰되었다. 잡종의 부화율은 네 수온(22, 25, 28, $31^{\circ}C$)에서 대체적으로 낮았으며, $25^{\circ}C$에서 9.8%로 가장 높았다. 이상의 연구에서 서식환경이 서로 다른 바리과 두 종간 잡종이 생산 가능한 것으로 조사되었으며, 향후 산업적 활용성을 검증하기 위하여 발생 양상, 기형률 및 초기 생존율 등에 관한 면밀한 연구가 필요할 것으로 판단된다.

• 한국어류학회지
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• 제31권4호
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• pp.235-240
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• 2019

자바리와 대왕자바리 2종을 대상으로 MS-222 농도 및 수온에 따른 마취효과 실험을 수행하였다. 농도는 100, 150, 200 그리고 250 ppm을, 수온은 18, 22, 26 그리고 30℃에서 마취 및 회복시간을 조사하였다. MS-222 농도와 수온이 높아질수록 마취시간이 짧아지는 경향을 보였으며, 회복시간은 농도와는 비례하지만 수온과는 반비례하는 경향을 보였다. 회복시간은 22℃ 이하에서는 큰 차이가 없었다. 자바리의 최적 마취조건은 회복시간이 가장 짧은 30℃와 100 ppm, 대왕자바리의 경우 30℃ 150 ppm이 회복시간이 100 ppm과 유의적으로 차이가 없으면서 마취시간은 유의하게 짧아 가장 적합했다. 이원배치분산분석 결과 자바리와 대왕자바리의 종 간 유의한 차이가 있었으나, 종과 농도 그리고 종, 농도, 수온에 대한 상호작용 효과는 없었다.

• 환경생물
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• 제38권1호
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• pp.40-46
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• 2020

본 실험에서 암모니아 급성 노출은 대왕범바리의 혈액학적 성상 및 혈장 성분에 유의적 변화를 나타내었다. 본 실험의 결과 20mg L^-1 이상의 급성 암모니아 노출은 대왕범바리의 혈액학적 성상 및 혈장 성분에 영향을 주어 생리적 변화를 일으키며, 40mg L^-1의 급성 암모니아 농도는 대량 폐사를 유발할 수 있음을 나타낸다. 향후 대왕범바리 바이오플락 양식기술 적용을 위한 양식연구에 이러한 결과를 지표로 활용할 수 있을 것이다.

• Ocean and Polar Research
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• 제42권4호
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• pp.303-311
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• 2020

In this study, the embryonic development and hatchability of eggs fertilized by the reciprocal hybrids of kelp grouper (Epinephelus bruneus) and red-spotted grouper (E. akaara) were evaluated with the goal of establishing a novel hybrid with enhanced growth and viability during the farming period in the temperate waters of Korea. The fertilization rates were lower for hybrids than for maternal purebreds and were significantly higher in the red-spotted grouper ♀ × kelp grouper ♂ hybrid (RGKG, 89.61 ± 1.58%) than in the kelp grouper ♀ × red-spotted grouper ♂ hybrid (KGRG, 74.82 ± 4.23%, p < 0.05). Unlike the fertilization rates, the hatching rates of fertilized eggs were similar between hybrids and maternal purebreds and did not differ significantly between KGRG and RGKG (72.74 ± 3.60% vs. 75.23 ± 2.20%, respectively, p > 0.05). The embryonic development of the hybrids was similar to that of maternal purebreds; however, irregular cleavage and asymmetric blastoderm were noticeable in the developing eggs of KGRG hybrids. The deformity rates of newly hatched larvae were higher in hybrids than in maternal purebreds and were significantly higher in KGRG than in RGKG (17.47 ± 1.28% vs. 7.11 ± 0.54%, respectively, p < 0.05). These results demonstrate the potential to produce viable larvae from these two hybrids. Although the production efficiency of KGRG was lower than that of RGKG, the fertilization, hatching, and deformity rates make both hybrids useful for further comparative studies regarding economic aspects.

• 한국수산과학회지
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• 제55권2호
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• pp.129-136
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• 2022

The nutrient composition of the muscle of the hybrid grouper (Epinephelus fuscoguttatus×E. lanceolatus, HG) and the hybrid longtooth grouper (E. moara×E. lanceolatus, HLG) was measured as a function of body weight in this study. The crude protein and lipid levels in HG were 21.0-21.2 g/100 g and 1.9-3.4 g/100 g, respectively. HLG contained 20.6-20.7 g/100 g protein, and 3.9-5.5 g/100 g crude lipid. The total amino acid contents of HG were 18,829.7-18,980.2 mg/100 g and that of HLG was 17,793.7-19,293.7 mg/100 g. The mean saturated fatty acid content was 0.61-1.09 g/100 g for HG and 1.27-1.77 g/100 g for HLG. Monounsaturated and polyunsaturated fatty acid levels were 0.59-1.02 g/100 g (Monoene), 0.67-1.11 g/100 g (Polyene) in HG, which were lower than the 1.21-1.78 (Monoene), 1.22-1.69 g/100 g (Polyene) found in HLG. The highest mineral content (K and P) of HG was 510.13-517.05 mg/100g and 231.59-247.67 mg/100 g, while that of HLG was 518.81-523.59 mg/100 g and 257.51-248.84 mg/100 g, respectively. In conclusion, there is potential for expanding the commercial utilization of HG and HLG as food resources as they are both nutrient-rich.

• 한국수산과학회지
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• 제49권5호
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• pp.612-619
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• 2016

In this study, we crossbred Epinephelus akaara and E. lanceolatus to produce a hybrid grouper with faster growth and adaptation to domestic aquaculture environments. The plasma cortisol and glucose levels and osmoregulation (stress response indicators) of the hybrid grouper, E. akaara ♀ × E. lanceolatus ♂, were investigated under several salinity levels (32, 24, 16, and 8 psu). The body lengths and weights of E. akaara (8.2 ± 0.1 cm, 8.3 ± 0.4 g) and the hybrid (8.6 ± 0.1 cm, 10.0 ± 0.4 g) were similar at the start of the experiment, but were significantly different at the end of the experiment. Juveniles of both E. akaara and the hybrid showed greater weight gain, specific growth, and feed conversion rate (FCR) under low salinity of 16 psu. Under the 8 psu treatment, the juvenile E. akaara all died, while the hybrid juveniles survived. Plasma cortisol levels were not affected by lower salinity in both species. The above results indicate that the hybrid is more tolerant of low salinity than is E. akaara, although both species exhibited higher growth and FCR at 16 psu, lower than the salinity of natural seawater. Thus, juveniles of both E. akaara and the hybrid can be more effectively cultured in brackish areas or waters with salinity lower than that of seawater.

• Ocean and Polar Research
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• 제44권4호
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• pp.365-372
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• 2022

The present study measured the growth performance of juvenile hybrid of red-spotted grouper ♀ × giant grouper ♂ (RGGG) across four water temperatures (19, 23, 27, and 31℃) and compared it to those of maternal purebreds (red-spotted grouper ♀ × ♂, RG) for eight weeks. The specific growth rate (SGR) and weight gain (WG) of RGGG increased as temperature increased, with greater SGR and WG at higher temperatures (27 and 31℃) than RG. The condition factor of RGGG was higher than that of RG and there were no differences between temperature groups within breeding lines. Food consumption increased at higher temperatures for both RGGG and RG, and was the highest in the 31℃ group. Similar to the SGR and WG, the food conversion rate (FCR) in RGGG decreased with increasing water temperature, with the significantly lowest value at 31℃; in RG, however, FCR progressively decreased in the 27℃ group, then increased in the 31℃ group. Furthermore, the FCR of the 31℃ group of RGGG, which had the lowest value among the RGGG groups, was lower than that of the 27℃ group of RG, which had the lowest RG value. In the analysis of nonlinear regression curves within the range of experimental temperature, the optimum temperature for SGR and FCR in RGGG was 31℃, unlike in RG. In conclusion, the growth performance of juvenile RGGG seems to have largely improved from the influence of paternal traits, hybrid with giant grouper, and it is presumed to be more profitable for commercial production in tropics/subtropics.

• 한국어류학회지
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• 제31권1호
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• pp.23-29
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• 2019

이번 연구에서 바리과 어종의 새로운 교잡종을 생산하기 위한 연구의 일환으로 능성어 (Hyporthodus septemfasciatus) ♀${\times}$대왕바리 (Epinephelus lanceolatus) ♂ (CGGG)의 발생 양상, 부화율, 기형 발생률 그리고 부화 소요시간을 조사하고, 교잡종의 모계어종의 순종 (능성어 ♀${\times}$♂, CG)과 비교하였다. CGGG와 CG 수정란은 자외선 살균 해수가 채워진 5-L 용량의 비이커 9개에 3,000~5,000개/비이커의 밀도로 수용되었으며, 발생 기간 중 수온은 $23.5{\sim}24.8^{\circ}C$ 그리고 염분은 32.1~32.8 ppt 였다. CGGG의 수정률과 부화율은 각각 $69.4{\pm}1.5%$와 $59.0{\pm}5.1%$로서 CG에 비해 유의하게 낮았다 (p<0.05). CGGG는 비균등 난할, 배체 체형 기형 그리고 부화자어의 척추 기형이 높게 출현한 것을 제외하고, CG와 동일한 난발생 양상을 보였다. CGGG의 부화까지 소요 시간은 CG에 비해 약 2시간 느렸다(p<0.05). 이상의 결과에서 CGGG는 수정률, 부화율 그리고 기형률 등 발생능력이 CG에 비해 낮았지만 부화자어의 대량생산이 가능할 것으로 판단된다.