• 한국수산과학회지
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• 제55권3호
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• pp.379-385
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• 2022

This study was conducted to evaluate the dietary supplementation of citrus byproduct (CBP) on the growth performance, feed utilization, and innate immune responses of juvenile olive flounder Paralichthys olivaceus under low water temperatures (11-15℃). Dietary L-ascorbyl-2-polyphosphate was replaced with graded CBP levels at 0 (Con), 25 (CBP25), 50 (CBP50), 75 (CBP75), and 100% (CBP100). Triplicate groups of juvenile olive flounder were handfed with one of the diets twice a day for 42 days. The growth performance and feed utilization of fish fed with diet containing levels of CBP75 or CBP100 increased significantly compared to those of fish with fed Con. Dietary CBP supplementation increased the protein efficiency ratio in fish. There was no significant differences in innate immune responses between groups, even though CBP supplementation tended to increase. These findings indicate that CBP could be used as a vitamin C source and improve the growth performance of juvenile olive flounder under low water temperatures.

• Fisheries and Aquatic Sciences
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• 제21권3호
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• pp.12.1-12.15
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• 2018

A preliminary investigation of length-weight relationship, condition factor and reproductive ecology of African pike fish, Hepsetus odoe, was conducted between June to August 2010 in Lake Eleiyele. A total of 90 samples of the fish species were caught by fishermen using gill nets. The results obtained showed that fish species had isometric growth pattern (contrary to negative allometry expected) with the growth exponent, b value of 2.64, that is not statistically different from 3 and with high statistical power of 0.866 when tested. The mean condition factor, K, was found to be 2.6, indicating that the fish species were in good condition in the study area. For reproductive biology, mean fecundity and gonadosomatic index were found to be 1349 eggs and 3.53% respectively. This study was necessary to fill the knowledge gap and provide information for management and conservation of the investigated species in the lake system. This study recommended that further research needs to be conducted because the sampling was carried out in the rainy season period and within a quarter of a year.

• Fisheries and Aquatic Sciences
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• 제26권8호
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• pp.461-469
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• 2023

The objective of this study was to evaluate how the tank colours may change the effects of extreme temperature on the survival, growth, and quality of juvenile golden trevally (Gnathanodon speciosus). The experiment was set up with fifteen treatments of five tank colours (blue, red, yellow, grey, and white) and three temperatures (30℃, 32℃, 34℃) with three replications. Fish performance was assessed for four weeks. The results showed that tank colours and elevated temperatures affected the quality of golden trevally juveniles. The survival and growth rate of fish tend to decrease gradually, but the deformation rate of fish tended to increase in the order of tank colours: red, yellow > grey, blue, and white. The growth and survival rate of fish gradually decreased when the rearing temperature increased from 30℃ to 34℃ and this effect was independent of tank colors. Importantly, the deformation rate increased under elevated temperature, particularly in blue and white tanks with potential long-term effects. It is, therefore, not recommended to use blue and white tanks for rearing the golden trevally juveniles, particularly during extremely high temperatures from heatwave events.

• Fisheries and Aquatic Sciences
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• 제26권1호
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• pp.58-68
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• 2023

This study was conducted to determine dietary threonine (Thr) requirement for juvenile olive flounder (Paralichthys olivaceus). A total of 450 juvenile fish (23.2 ± 0.4 g) were randomly distributed to 18 tanks (215 L) with 25 fish per tank. Experimental diets included with graded levels of Thr at 0.0%, 0.4%, 0.8%, 1.2%, 1.6%, and 2.0% were assigned for triplicate groups of fish and fed two times daily to apparent satiation for 12 weeks. Weight gain, specific growth rate, feed intake, feed utilization and survival were significantly (p < 0.05) increased in fish fed with dietary Thr levels over 0.8%, and no significant differences were observed between 0.8% to 2.3% levels. Non-specific immune parameters of serum lysozyme, myeloperoxidase activity, antiprotease activity, and total immunoglobulin were significantly increased by dietary Thr over 0.8%. Based on the broken-line regression analysis, the Thr requirement for the optimum growth and immune response in olive flounder is likely to be 1.03% in the diet.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2019년도 정기학술대회 발표논문집
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• pp.202-202
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• 2019

Mealworm (Tenebrio molitor) was evaluated to investigate the effect of partial or total replacement of fish meal in diets for white shrimp, Litopenaeus vannamei. Experimental groups of shrimp with average initial body weight (2.43 ± 0.54 g) were fed each with 4 isonitrogeneous (38% crude protein) diets formulated to include 0, 25, 50 and 100% (diets 1 to 4, respectively) of fish meal substituted with mealworm. After eight weeks of feeding trials, shrimp fed with diet 3 and 4 revealed the highest values for live weight gain(8.01 ± 2.51 and 7.93 ± 1.12), specific growth rates (2.70 ± 1.12 and 2.59 ± 0.51) as well as better feed conversion ratio (2.69 ± 0.09 and 2.72 ± 0.19) compared to the control group with statistically significant manner (p<0.05). Survival range was 98% in all the treatments. An increase in weight gain and other growth associated parameters was observed with higher replacement. These results clearly indicate that 50% and 100% of fish meal protein in shrimp diet can be replaced by mealworm not only without any adverse effect but also the effect of promoting growth performance.

• 한국수산과학회지
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• 제56권5호
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• pp.716-720
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• 2023

This study was designed to analyze the effects of reducing water turnover in olive flounder Paralichthys olivaceus farms, focusing on olive flounder growth, decreasing electricity costs, and developing measures to ensure business stability. Daily water turnover was set at 18 in the control group and six in the experimental group. Juvenile fish were reared for 12 months. No significant differences in mean weight were observed between groups until five months. After five months, the mean weight of the control group grew significantly faster than that of the experimental group. Maintaining water turnovers leverl at six turnovers for the first five months after stocking juvenile fish and then increasing water turnover resulted in a 34.4% reduction in electricity costs compared to the control group. This approach presents a potential method to enhance the profitability of olive flounder farms and ensure stable productivity and profitability without sacrificing olive flounder growth.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2001년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.293-294
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• 2001

In nutrition studies of fish, determining the optimum dietary protein level for growth of fish is generally a primary consideration because protein is not only the major constituent of fish body, but also it has critical functions as enzymes and hormones. Many studies have been carried out to determine the protein requirements of fish, and the estimated protein requirements range from 30％ to 55％ of diet. (omitted)

• 한국양식학회지
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• 제21권4호
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• pp.265-271
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• 2008

유럽과 중국에서 양식 대상종으로 각광을 받고 있는 터봇 Scophthalmus maximus의 하계 국내 사육 가능성을 평가하고자 사육수온과 밀도에 대한 성장 특성을 비교하였다. 수온별 실험 결과 성장은 $20^{\circ}C$에서 가장 빨랐으며, 생존율은 $20^{\circ}C$와 $23^{\circ}C$ 모두 98.4%, 비만도는 $3.96{\sim}4.14$, 사료계수는 $0.84{\sim}0.89$로 차이가 없어 $23^{\circ}C$에서도 사육이 양호하였다. 수온 $26^{\circ}C$에서는 20일까지 일간성장률이 양호하였으며 50일 이후 폐사개체가 증가하여 60일에는 60.9%를 나타내었다. $29^{\circ}C$에서는 실험시작 7일 후에 전개체가 폐사되었다. 밀도별 사육실험 결과 생존율은 200마리/$m^2$ 실험구가 99.4%, 160 마리/ 실험구가 100%, 120 마리/실험구가 97.9%, 80 마리/$m^2$ 실험구가 98.4%로 각 실험구 모두 양호한 생존율을 보였다. 사육실험 결과 200 마리/$m^2$ 실험구는 다른 저밀도 실험 실험구와 비만도, 일간성장률, 사료계수의 차이가 없었고, 최종사육밀도는 $10\;kg/m^2$로 넙치보다 고밀도로 사육이 가능함이 확인되었다. 이상의 결과로부터 하절기에 $25^{\circ}C$ 이상의 수온이 거의 나타나지 않는 울진 이북 동해안 지역은 터봇을 사육하는데 적합한 수온 조건을 지니고 있으며, 수온 $26^{\circ}C$가 20일 이내인 지역이라면 터봇 종묘를 양성하는데 지장이 없을 것으로 사료되었다.

• 한국수산과학회지
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• 제48권3호
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• pp.308-313
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• 2015

A $3{\times}3$ factorial study was conducted to investigate the effects of dietary protein and lipid levels on the growth, feed utilization and innate immunity of red seabream Pagrus major. Nine diets consisting of three protein levels (42%, 46% and 50% crude protein) and three lipid levels (10%, 14% and 18% crude lipid) were formulated. Triplicate groups of red seabream were fed the experimental diets to apparent satiation (5-6 times a day, from 08:00 to 18:00 h at 2-h intervals) for 10 weeks. At the end of the feeding trial, the weight gain and specific growth rate of fish fed P46L14 (46% protein and 14% lipid), P50L10 (50% protein and 10% lipid) and P50L14 (50% protein and 14% lipid) were significantly (P<0.05) higher than those of fish fed P42L18 (42% protein and 18% lipid). The feed conversion ratios (FCR) of the fish were affected by dietary lipid levels (P<0.039), but not dietary protein levels. The FCR tended to increase with increasing dietary lipid levels from 10% to 18% with the 46% and 50% protein levels. The weight gain, protein efficiency ratio, specific growth rate, feed intake and survival of fish were not affected by either dietary protein or lipid levels. Myeloperoxidase activity in the group fed P50L14 (50% protein and 14% lipid) was significantly higher than that in the group fed P42L10 (42% protein and 10% lipid) or P50L18 (50% protein and 18% lipid). However, the myeloperoxidase activity of fish was not affected by either dietary protein or lipid level. The fish fed P46L14 (46% protein and 14% lipid) and P46L18 (46% protein and 18% lipid) showed significantly higher superoxide dismutase activity than did the fish fed P46L10 (46% protein and 10% lipid), P50L10 (50% protein and 10% lipid) of P50L18 (50% protein and 18% lipid). In conclusion, the optimum protein and lipid levels for the growth and feed utilization of juvenile red seabream were 46% and 14%, respectively, and the optimum dietary protein to energy ratio was 27.4 g/MJ.

• 한국양식학회지
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• 제17권4호
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• pp.240-245
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• 2004

본 연구에서는 우리나라 남동해 연안에서 4계절 동안 나타나는 전형적 수온 범위(3~33$^{\circ}C$)에서 양성용 농어의 사료 섭식량 및 효율,성장,생존 등에 있어 수온의 영향을 파악해 보고, 양성시 농어의 최적 사육수온 조건을 구명하고자 실시하였다. 실험 결과,농어는 수온 범위 6-3$0^{\circ}C$적정한 어종으로 판단되지만, 사료섭식량, 사료효율, 성장, 생존을 동시에 고려했을 때, 정상적인 양성을 위해서는 동절기 수온을 17$^{\circ}C$이상 유지하는 것이 정상적인 성장을 유지해 줄 수 있으며, 하절기의 경우 수온 21-27$^{\circ}C$가 적정 한 것으로 판단된다.