• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.173-174
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• 2003

Dietary proteins are the most important factors affecting growth performance of fish and feed cost. Generally, most of the formulated diets for marine fish include a large amount of fish meal as a protein source because of its high nutritive value and palatability. Quality of fish meal in diet may affect on growth and feed efficiency of fish. Therefore, this study was conducted to evaluate the effect of various fish meals as dietary protein source on growth and feed utilization of the juvenile flounder. (omitted)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.796-800
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• 2014

A feeding trial was conducted to investigate the growth and body composition of juvenile sea cucumber Apostichopus japonicus in integrated culture with abalone Haliotis discus hannai or rockfish Sebastes schlegeli. Triplicate groups of sea cucumber averaging $1.2{\pm}0.05g$ were cultured alone or with abalone or rockfish for 12 weeks. Survival of sea cucumber was not affected by co-culturing (P>0.05). Weight gain of sea cucumber cultured with rockfish was significantly higher than that of sea cucumber cultured alone (P<0.05), and did not differ from that of those cultured with abalone (P>0.05). These findings indicate that co-culturing sea cucumber with rockfish effectively improves the growth of sea cucumber.

• Journal of Aquaculture
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• v.19 no.4
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• pp.242-246
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• 2006

Comparisons of growth and survival rate in different culture systems for juvenile abalone were determined in the West Coast of South Korea from June, 2000 to April, 2001. Daily growth rate reached at the maximum by $148.6{\pm}48.96\;{\mu}m/day$ with a stagnant system and at the minimum by $95.3{\pm}21.45\;{\mu}m/day$ with a sprinkler culture system. Survival rate of the juvenile abalone was significantly higher than that in sprinkler culture with a rotary culture (P<0.05). The highest survival rate was 50.0% in the rotary culture and 38.3% was observed in the stagnant culture system. The results from this study indicate that effective survival and growth rate could be predicted in the rotary culture system.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.12
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• pp.1794-1799
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• 2008

This preliminary feeding trial was conducted to study the effects of different dietary selenium (Se) levels on growth performance and toxicity in juvenile black seabream, Acanthopagrus schlegeli (Bleeker). Fish averaging $7.0{\pm}0.1g$ ($mean{\pm}SD$) were fed one of the five semi-purified diets containing 0.21, 0.30, 0.52, 1.29 and 12.3 mg sodium selenite ($Na_2SeO_3$)/kg diet (Se 0.21, Se 0.30, Se 0.52, Se 1.29 or Se 12.3) for 15 weeks. After the feeding trial, weight gain (WG), feed efficiency (FE), specific growth rate (SGR) and protein efficiency ratio (PER) of fish fed Se 0.21, Se 0.30, Se 0.52 and Se 1.29 diets were not significantly different, however fish fed Se 12.3 diet showed significantly lower WG, FE, SGR and PER than those of fish fed the other diets (p<0.05). Fish fed Se 0.21, Se 0.30, Se 0.52, Se 1.29 and Se 12.3 diets showed no significant differences in hematocrit (PCV), hemoglobin (Hb) and red blood cells (RBC), however fish fed Se 12.3 diet showed lower values of PCV, Hb and RBC than those of fish fed the other diets. Histopathological lesions such as tubular necrosis and polycystic dilation of tubules in the kidney tissues were observed in fish fed Se 12.3 diet. Se was accumulated in a dose-dependent manner in the liver, kidney, muscle and gill tissues. Based on the results of this preliminary feeding trial, a dietary Se level of 0.21 mg $Na_2SeO_3/kg$ diet could be optimal for proper growth performances, and a dietary Se level of 12.3 mg $Na_2SeO_3/kg$ diet may ultimately be toxic to juvenile black seabream, Acanthopagrus schlegeli.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.371-376
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• 2013

A feeding trial was conducted to determine the optimum dietary protein and lipid levels for the growth of juvenile muddy loach Misgurnus anguillicaudatus. Eight experimental diets (designated as P20L7, P20L14, P30L7, P30L14, P40L7, P40L14, P50L7 and P50L14) were formulated to contain 20%, 30%, 40% and 50% protein with 7% and 14% lipid. Three replicate groups of muddy loach (1.5 g/fish) were fed one of the experimental diets ad libitum for 8 weeks. Survival of fish fed the P20L14 diet was lower than in other groups (P<0.05). Specific growth rate (SGR) and feed efficiency (FE) of fish were affected by dietary protein (P<0.05) and lipid (P<0.005) levels. SGR and FE of fish tended to decrease with increasing dietary lipid level at the same protein level. There were no significant differences in SGR and FE among fish fed diets containing different protein levels ranging from 30% to 50% with the same lipid level. Whole body moisture and lipid contents were affected by dietary protein and lipid levels. Crude lipid content of fish fed the 14% lipid diets was higher than that of fish fed 7% lipid diets at each protein level. The results of this study indicate that a diet containing 30% protein with 7% lipid would be suitable for the optimum growth and effective feed utilization of juvenile muddy loach.

• Fisheries and Aquatic Sciences
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• v.10 no.4
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• pp.191-195
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• 2007

The aim of this study was to assess whether size-rank at the juvenile stage is associated with growth performance and sex ratio in olive flounder (Paralichthys olivaceus). Juveniles (mean body weight, $8.8{\pm}0.9\;g$) were selected from two age groups, with the high size-rank group (HSRG) fish in the upper 19.3-67.3% of 104 days post-hatching (dph) age group and the low size-rank group (LSRG) fish in the lower 9.0-55.7% of 116 dph age group. Triplicate groups of 100 fish were reared over 32 weeks. A heavier final body weight was observed in the HSRG ($360{\pm}12\;g$) compared to the LSRG ($315{\pm}9\;g$, P<0.05), whereas no differences in feed intake, feeding efficiency, and mortality were seen between the experimental groups. The percentage of females was significantly higher in the HSRG (51.7%) than in the LSRG (30.8%, P<0.05). In addition, a remarkable increase in growth was recorded in females, indicating that the relative frequency of females increased with a body weight increase. The results suggest that high size-rank juvenile olive flounder have better growth performance and a higher percentage of females, because females start growing faster than males before size grading occurs.

• Fisheries and Aquatic Sciences
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• v.18 no.1
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• pp.51-56
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• 2015

A 8-week trial was conducted to evaluate the effects of photoperiod manipulation on the growth performance and hematological parameters of juvenile Caspian roach, Rutilus rutilus caspicus (average weight $1.46{\pm}0.12g$ mean${\pm}$SD) reared under five photoperiods (24 h Light, 24L; 18 h Light & 6 h Dark, 18L:6D; 12 h Light & 12 h Dark, 12L:12D; 6 h Light & 18 h Dark, 6L:18D; 24 h Dark, 24D) with constant light intensity 1,500 lx on the water surface. Triplicate of 20 fish were allocated into each of 15 fiberglass tanks of 50 L capacity and they were fed three times per day with the commercial feed (SFK, Co., Sari - Iran) contains 50.0% protein and 10.5% lipid. At the end of experimental period, final body weight, weight gain and specific growth rates of fish exposed to 24L were significantly higher than those of fish exposed to 12L:12D, 6L:18D and 24D (P < 0.05). Red blood cell and hemoglobin of fish exposed to 24L were significantly higher than those of fish exposed to 24D. No significant difference observed in hematocrit, white blood cell and plasma glucose among the different treatments groups. Therefore, these results demonstrated that the growth performance of juvenile Caspian roach can be significantly stimulated by using 24L and 18L:6D photoperiods without any measurable significant stress response such as plasma glucose concentration.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.11
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• pp.1588-1594
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• 2012

An 8-wk experiment was conducted to evaluate the effect of replacing fish meal (FM) with soy protein isolate (SPI) on the growth, digestive enzyme activity and serum biochemical parameters of juvenile Amur sturgeon (Acipenser schrenckii). SPI was used to replace 0, 25, 50, 62.5, 75, 87.5, 100% of dietary FM and 100% replacement supplemented crystalline amino acid. Healthy sturgeon with an average initial weight of $26.38{\pm}0.24$ g were randomly assigned to 24 aquaria (8 treatments with triplicates each) at an initial stocking density of 11 fish per aquarium and cultured for 8 wks. The results showed that 75.00% or more substitution resulted in a poor weight gain rate, feed conversion ratio and survival rate compared to that of fish fed the control diet (p<0.05), whereas no significant differences were observed between diets of 25.00% to 62.50% substitution. Protease, lipase and amylase activity in foregut, mid-gut and hindgut were significantly (p<0.05) decreased by diets where SPI replacement levels were 62.50% or more. Levels of serum total protein (TP) and globulin decreased significantly from 21.03, 10.34 to 14.05, 5.63 g/L with the increasing dietary SPI (p<0.05), but alkaline phosphatase activity significantly increased (p<0.05). In addition, supplemental crystalline amino acid in the FM absence diet did not improve growth performance, intestine digestive enzyme activities and serum biochemical parameters. In conclusion, the results from this study showed adverse effects of inclusion of SPI in diets on growth performance, feed utilization and serum biochemical parameters in juvenile Amur sturgeon. Based on WGR and replacement ratio presented in this report, a 57.64% replacement level was recommended.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.3
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• pp.407-413
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• 2011

Effect of dietary protein and lipid levels on compensatory growth of juvenile olive flounder (Paralichthys olivaceus) was determined in suboptimal temperature ($13.4{\pm}1.42^{\circ}C$). Five hundred forty fish averaging 79.2 g were randomly distributed into 27 of 300 L flow-through tanks (20 fish/tank). Nine treatments were prepared in triplicate: fish were hand-fed with control (C) diet for 10 weeks (10WF-C); four fish groups were starved for 1 week and then fed with C, high protein (HP), high lipid (HL) and combined high protein and high lipid (HPL) diets for 9 weeks, referred to as 9WF-C, 9WF-HP, 9WF-HL, 9WF-HPL, respectively; and other four fish groups were starved for 2 weeks and then fed with C, HP, HL and HPL diets for 8 weeks, referred to as 8WF-C, 8WF-HP, 8WF-HL and 8WF-HPL, respectively. Weight gain and specific growth rate of fish in 9WF-HP, 9WF-HPL, 8WF-HP and 8WF-HPL treatments were higher than those of fish in 9WF-HL and 8WF-HL treatments. Feed efficiency of fish in 8WF-HP treatment was higher than that of fish in 9WF-C, 9WF-HL and 8WF-HL treatments. Protein efficiency ratio of fish in 10WF-C, 8WF-C, 8WF-HP and 8WF-HPL treatments was higher that that of fish in 9WF-HL and 8WF-HL treatments. Juvenile olive flounder subjected to 2-week feed deprivation could achieve full compensatory growth with dietary supplementation of protein or combined high protein and high lipid.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.12
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• pp.1769-1775
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• 2006

An eight week feeding trial was conducted to investigate the effects of dietary supplementation of hizikia (Hizikia fusiformis) on growth performance, immune responses and resistance of juvenile olive flounder (Paralichthys olivaceus) to Streptococcus iniae. Four experimental diets (designated as Hiz 0, Hiz 2, Hiz 4 and Hiz 6) were formulated to be isonitrogenous (50% crude protein) and isocaloric (17.2 MJ/kg DM). Hizikia powder was added at 0%, 2%, 4% and 6% in diets Hiz 0, Hiz 2, Hiz 4 and Hiz 6, respectively. Three replicates of fish groups (15 fish/tank) were fed one of the experimental diets. At the end of feeding trial, no significant differences were observed in final body weight, specific growth rate, protein efficiency ratio, feed utilization and feed intake among fish groups fed the experimental diets. However, there was clear trend that the growth performances of fish were improved by the increment of dietary hizikia showing a positive growth effects. Mean phagocytes activated with nitro-blue-tetrazolium were significantly increased with the increment of dietary hizikia. The cumulative mortality was significantly (p<0.05) lower in the fish groups fed Hiz 6 diet (no mortality) than that in the other fish groups for 15 days of S. iniae challenge test. The findings of this study suggest that a dietary supplementation of hizikia could enhance the nonspecific immune response and improve the resistance of juvenile olive flounder to S. iniae.