• Journal of Aquaculture
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• v.20 no.1
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• pp.1-6
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• 2007

Two feeding experiments were conducted to investigate the effects of fermented cactus fruit (Opuntia ficusindica) fluid (FCFF) as a feed additive to a commercial diet on the growth of red sea bream, Pagrus major, and to determine an effective dose. FCFF was prepared by mixing crushed cactus fruit with a starch solution and commercially available microorganisms for 2 weeks at room temperature. Three triplicate groups of red sea bream had initial mean weights of 84.1 g (Exp-1) and 5.1 g (Exp-2) and were fed experimental diets containing 0%, 1%, and 5% FCFF for 2 months (Exp-1) and 0%, 0.2%, 0.5%, and 1% FCFF for 3 months (Exp-2), respectively. In experiment 1, the mean body weight of fish fed the diet containing 1% FCFF was significantly higher (P<0.05) than that of fish fed the diet without FCFF. The survival rate was highest in fish fed the diet containing 1% FCFF, although the difference was not statistically significant. The feed gain ratio (FGR), specific growth rate (SGR), and condition factor (CF) values of fish fed the diet containing 1% FCFF were higher than those of fish in the other dietary groups that received lower levels of FCFF. The daily feeding rate (DFR) of fish fed the diet containing 1% FCFF was slightly lower but not statistically different than the DFR values of fish in the other dietary groups. In experiment 2, the final mean body weight of fish fed the diet containing 1% FCFF was significantly (P<0.05) higher than the mean weight of fish in the control group. The FGR, SGR, and CF values of fish fed the diet containing 1% FCFF were better than the values from fish in the other dietary groups that received lower levels of FCFF, although the differences were not statistically significant. However, the DFR of fish fed the diet containing 1% FCFF was lower than those of fish in the other groups. These results suggest that FCFF could be used as a feed additive in commercial fish food and a preferable level of supplementation is at least 1.0% in fingerling and young red sea bream.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.620-627
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• 2016

A 60-day experiment was conducted to determine the effect of feeding and starvation on the survival, growth, and blood parameters of red sea bream Pagrus major. The starved group was not fed during the first 32 days of the experiment and was then fed for 28 days. The growth rate of the starved fish group was significantly lower than that of the fed fish group. Starvation resulted in growth retardation and reductions in final body weight, growth rate, specific growth rate, and condition factor, whereas the fed fish group grew well and maintained a good condition. The growth rate of the starved group that was refed was higher than that of the fed group. Red blood cells, hematocrit, and hemoglobin showed no significant differences between the fed and starved groups. The cortisol and glucose levels of the fed group of juveniles were higher than those of the starved group. The cortisol levels of the starved group of adults were higher than those of the fed group, whereas the glucose levels of the starved group were lower than those of the fed group. These results suggest that the survival, growth, and hematological parameters used to reflect starvation and feeding in this study provide a useful index of physiological response and survival rate in red sea bream.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.810-817
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• 2014

Two consecutive feeding trials were conducted to evaluate the effects of extruded pellet (EP) and raw fish-based moist pellet (MP) in the juvenile (experiment I) and sub-adult (experiment II) stages of olive flounder, Paralichthys olivaceus. The fish were distributed randomly to three aquarium tanks, as a group of 1,200 fish (initial mean weight $13.5{\pm}1.76g$) in experiment I, and as a group of 390 fish (initial mean weight $385{\pm}15.3g$) in experiment II. In experiment I, the weight gain, specific growth rate, feed efficiency, protein efficiency ratio, and survival of fish fed EP were all significantly higher than those of fish fed MP. In experiment II, no significant differences were observed in weight gain, specific growth rate and survival between the EP and MP groups. However, the feed efficiency and protein efficiency ratios of fish fed EP were significantly higher than those of fish fed MP. The results of this study indicate that EP could be developed to replace MP for market size production of olive flounder without any adverse effects on the growth performance. The dietary formulation used in this study could be used as an appropriate feed for olive flounder.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.2
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• pp.272-277
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• 2012

Compensatory growth of grower olive flounder (Paralichthys olivaceus) was determined at suboptimal temperature ($13.0{\pm}1.9^{\circ}C$). Fifteen fish averaging 201.1 g per tank were distributed into 18 of 300 L flow-through tanks. Six treatments were prepared in triplicate: fish were hand-fed with an extruded pellet to apparent satiation once a day for 16 weeks (16 WF); and the other five groups of fish were hand-fed for 15, 14, 13, 12 and 10 weeks after 1-, 2-, 3-, 4- and 6-week feed deprivation, referred to as 15 WF, 14 WF, 13 WF, 12 WF and 10 WF, respectively. A linear relationship between body weight of fish and feed deprivation was observed: Y (Body weight of fish) = -1.81X (Weeks of feed deprivation)+201.07, $R^2$ = 0.83. Weight gain of grower olive flounder in 15 WF, 14 WF, 13 WF and 12 WF treatments was comparable to that of fish in 16 WF treatment, but lower than that of fish in 10 WF treatment. Specific growth rate of fish in 15 WF treatment was higher than that of fish in 16 WF, 14 WF and 10 WF treatments. Feed consumption of fish was not affected by feeding regime. Feed and protein efficiency ratios of fish in 15 WF treatment were higher than those of fish in 13 WF, 12 WF and 10 WF treatments. Grower olive flounder could achieve full compensatory growth when fish were daily fed for 12 weeks after 4-week feed deprivation at suboptimal temperature.

• Fisheries and Aquatic Sciences
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• v.5 no.2
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• pp.103-107
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• 2002

A 6-week feeding trial was conducted to investigate the effects of six different dietary animal protein sources on growth and body composition of olive flounder, Paralichthys olivaceus in recirculating system. White fish meal (WFM), flounder muscle (FLM), carp muscle (CM), blood meal (BM), squid liver powder (SLP) and casein (CA) were used as the main animal protein sources in the six experimental diets. Fish averaging $2.9\pm0.03g$ $(mean\pm SD)$ were distributed to each aquarium as a group of 15 fish and were fed one of the six experimental diets to each treatment of triplicate groups. After 6-week of the feeding trial, fish fed white fish meal (WFM) and flounder muscle (FLM) diets showed a significant higher weight gain $(WG\%)$ (P<0.05) than those of fish fed the CM, BM, SLP and CA diets. Fish fed BM diet showed the lowest WG among all the dietary treatments. Feed conversion ratio (FCR) and protein efficiency ratio (PER) showed the similar trend as WG. Hematocrit and hemoglobin were not affected by the dietary treatments. Fish fed the FLM and CM diets showed significant higher survival rate than those of fish fed BM diets, and there was no significant difference in survival of fish fed WFM, FLM, CM, SLP and CA diets. These results indicated that WFM and FLM are the best dietary protein sources tested in olive flounder.

• The Journal of Fisheries Business Administration
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• v.38 no.1 s.73
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• pp.1-17
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• 2007

This study is aimed at investigating optimum level of payments in the direct payment program for aquaculture extruded pellets both theoretically and practically by analyzing the effects on production and income in accordance with Green Box conditions of WTO Agreement on Agriculture. In particular, by analyzing both effects on production and income, it evaluates and compares payments affecting to the level of production and income, respectively. Analysis results indicate that the optimum level of payments in the direct payment program for aquaculture extruded pellets is determined by the growth rate of farmed fish, farming period, price and volume of extruded pellets, and additional amount of cost increase and decrease. Suppose that growth rates of farmed fish by extruded pellets(EP) and raw fish - based moist pellets(MP) are the same, it reveals the optimum level of payment should be lowered from the current level of payment. However, when the growth rate of farmed fish by EP is lower than that by MP, the optimum level of payment should be raised from the current level and total amount of payments by area should be increased as well.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.600-606
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• 2016

The effects of feeding frequency on the growth, food consumption, body composition, and hematological response of the Korean rockfish Sebastes schlegelii were investigated for 77 days at ambient water temperatures (17.2-24.5℃) in a sea cage in Tongyeong, Korea. Three replicate groups of fish were hand-fed to satiation with a commercial diet in one of four different feeding frequency trials (one meal every 2 days, and one, two and three meals per day). At the end of the experiment, the mean weight gain, specific growth rate, and daily feed intake of fish fed one and two meals per day were significantly higher than those of fish fed one meal every 2 days or three meals per day. The feed efficiency of the fish fed three meals per day was significantly lower than that of the fish in the other groups. The glucose concentration of fish fed one meal every 2 days was significantly higher than that of the other groups. We conclude that the optimum feeding frequency for improving the growth of Korean rockfish weighing 100-200 g reared in sea cages is one meal per day under our experimental conditions.

• Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.311-316
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• 2009

A 10-week feeding trial with four dietary protein levels (22%, 32%, 42% and 52%) and two dietary lipid levels (8% and 17%) was conducted to investigate the optimum dietary protein and lipid levels for growth of long-nosed barbel fingerlings. Survival rate of fish was not affected by either the dietary protein or the dietary lipid level. Weight gain and feed efficiency were affected by the dietary protein level (P<0.01), but not by the lipid level, and increased with the dietary protein level at the both lipid levels. Weight gain and feed efficiency of fish fed the 52% protein diets with 8-17% dietary lipids were not significantly different from those of fish fed the 42% protein diets with 8-17% dietary lipids and 32% protein diet with 17% dietary lipid. Daily feed intake of fish was not affected by either dietary protein or dietary lipid level. Protein efficiency ratio and protein retention rate of fish fed the 32% protein diet with 17% dietary lipid were significantly higher than those of fish fed the 52% protein diets with 8-17% dietary lipids. Moisture content of fish fed the diets containing 8% lipid were higher than those of fish fed the diets containing 17% dietary lipid at each protein level. Crude lipid content of fish fed the diets containing 17% dietary lipid were higher than that of fish the fed the diet containing 8% dietary lipid at each protein level. The results of this study indicated that 32% protein and 17% lipid could be the optimum dietary level for growth of juvenile long-nosed barbel.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.894-902
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• 2022

This study investigated the effects of photoperiod (NL 12L:12D and LL 24L:0D) and body sizes (30 g and 50 g) on parr-smolt transformation, post-smolt growth and blood properties in the off-season parr-smolt stage of Atlantic salmon reared in a recirculating aquaculture system (RAS). Potential off-season salmon smolt were reared in a freshwater RAS for 80 days and then all experimental fish were transferred to seawater. In both LL groups (LL-30 and LL-50), we recorded and increase in specific growth rate and reduction in feed conversion, although there were no significant difference in body size. The values of osmolality, and serum Na⁺, Cl^- and cortisol concentrations in the LL groups were maintained at lower levels than in NL group fish, and LL group fish were observed to recover to the pre-seawater adaptation state more rapidly than those in the NL group. ID chips were inserted in all smolts reared in freshwater. These fish were subsequently transferred to full-strength seawater and thereafter individual growth rates were monitored for 120 days. The results indicated that compared with smolt reared under natural photoperiodic condition, 24 h lighting in freshwater contributed to enhancing post-smolt specific growth rate in seawater.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.3
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• pp.611-618
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• 2016

A $3{\times}2$ factorial experiment was conducted to investigate effects of water temperature and feeding rate on growth and body composition of olive flounder. Triplicate groups of fish (initial body weight of 118 g) fed a extruded pellet (55% protein and 4708 cal/g) to satiation and at restricted feeding rates of 0.25 and 0.4% body weight per day (BW/d) at the different water temperatures (13 and $18^{\circ}C$) for 9 weeks. Weight gain increased significantly with increase in feeding rates at each temperature. Weight gain of fish fed to satiation was significantly higher at 18 than $13^{\circ}C$, whereas, that of fish fed at 0.25 and 0.4% BW/d were significantly or slightly lower at 18 than $13^{\circ}C$. Feed efficiency and protein efficiency ratio of fish fed to satiation were not significantly different between 13 and $18^{\circ}C$, but those of fish fed at 0.25 and 0.4% BW/d were significantly higher at 13 than $18^{\circ}C$. The major finding of this study is that satiation feeding is efficient for optimal growth and feed efficiency of grower oliver flounder (116-164 g) in suboptimal water temperatures. The maintenance feeding ration which is zero growth performance, were 0.30 and 0.41% BW/day at 13 and $18^{\circ}C$, respectively. In the restricted feeding regime, compromised growth of fish were worsen in higher water temperature ($18^{\circ}C$ vs. $13^{\circ}C$). It might be related to high metabolic rate of fish that spend more energy for maintenance metabolism. Based on these results, we suggest that a satiation feeding regime is recommended for a productive growth of grower olive flounder in the suboptimal temperature.