• Ocean and Polar Research
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• v.23 no.3
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• pp.279-284
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• 2001

The natural high productivity of temperate coastal waters in Korea can be used in advantage to reduce the feed costs for the cage-cultured marine carnivorous fish species. By using the night-lights methods an alternative of supplementary feeding strategy can be offered to the cage farmers and maintain sound environmental conditions that could enhance maximum sustainable yields. The aim of this study was to investigate the effects of night-lights which shown positive results on feeding and growth in sea cage cultured rockfish, Sebastes schlegeli. The study showed that for the water around overhead illuminated sea cage, higher zooplankton density was observed at night than during the daytime. Increased amounts of for-age, evidenced by stomach content analyses were observed in the early evening, but decreased amounts were observed in the morning and afternoon. That is, feeding activities of the fish were most intensive from midnight to dawn. In a three month feeding experiment, the results showed that night-lighted groups were superior to groups with the highest feeding efficient. This study suggested that the evidence that night-lights superimposed on only day-lights enhance growth of rockfish in sea cages during summer and winter, with timing of exposure affecting growth of juvenile fish. The capability to control the feeding behavior of marine life via manipulation and external stimuli could considerably benefit the advancement of sea cage aquaculture in coastal areas.

• Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.299-304
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• 2009

The effects of different feeding regimes on the compensatory growth of olive flounder Paralichthys olivaceus were investigated. Seven treatments with triplicates of different feeding regimes were conducted, as follows: (1) fed twice a day 6 days a week for 8 weeks; (2) starved for 1 week, then fed twice a day 6 days a week for 3 weeks; (3) starved for 2 weeks, then fed twice a day 6 days a week for 6 weeks; (4) starved for 5 days, then fed twice a day for 9 days; (5) starved for 10 days, then fed twice a day for 18 days; (6) starved for 2 days, then fed twice a day for 5 days, starved for another 3 days, and fed twice a day 4 days; and (7) starved for 4 days, then fed twice a day for 10 days, starved for another 6 days, and fed twice a day for 8 days. Forty fish averaging 12.5 g, were hand-fed to satiation according to the designated feeding schedule. Fish from the control group gained more weight than those from any other group. Feeding efficiency did not vary among treatments. In summary, olive flounder subjected to fasting with different feeding regimes did not fully compensate growth compared to fish fed for 8 weeks without fasting. In addition, the less that fasted groups were subsequently fed, the lower their compensatory growth.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.2
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• pp.169-175
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• 2014

The age and growth of rabbit fish, Siganus fuscescens were investigated from samples monthly collected in the coast of Jeju island, Korea from February to December 2012. Ages were determined from annuli in otoliths, and annuli were formed in one or two months immediately after spawning once a year. Also, main spawning period was estimated between July and August, thus rings were considered as annual marks. The von Bertalanffy growth equations estimated from a non-linear regression method were $L_t=37.24(1-e^{-0.33(t+1.24)})$ ($R^2=0.92$) for female and $L_t=31.44(1-e^{-0.45(t+1.23)})$ ($R^2=0.90$) for male, and the growth between female and male was different.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.524-532
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• 2022

We investigated the effects of taurine-enriched rotifers on larval growth and swim bladder inflation of yellowtail Seriola quinqueradiata. Rotifers were enriched with a commercial taurine supplement at two levels (0 and 800 mg/L). The larvae (initial notochord length=3.98±0.24 mm) were fed the enriched rotifers in triplicate from two days post-hatch for five days. The average taurine contents of the taurine non-enriched and enriched rotifers were 0.35±0.01 and 4.77±0.05 mg/g dry matter, respectively. The weight gain and specific growth rate of the fish fed enriched rotifers with the taurine supplement at 800 mg/L significantly improved compared with those of fish fed rotifers without taurine enrichment (P<0.05). The swim bladder inflation rate of larvae fed taurine enriched rotifers significantly (P<0.05). The results of the present study indicate that yellowtail larvae benefit from taurine concentrations compared with those typically reported to feed on non-taurine supplemented rotifers. Furthermore, taurine-enriched food for fish larval effectively improved the growth performance and swim bladder inflation of yellowtail larvae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.407-412
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• 2013

We performed four sets of feeding trials to establish optimum feed size (Exp-I), stocking density (Exp-II) and feeding frequency (Exp-III and IV) for Korean rockfish. In Exp-I, three different particle sizes of a commercial diet (small, 2.0-2.1 mm; medium, 2.4-3.2 mm; and large, 4.0-5.3 mm) were fed to four replicate groups of fish ($22.8{\pm}0.1g$), each of which was fed to apparent satiation for six weeks. In Exp-II, fish ($44.3{\pm}0.4g$) were reared at four stocking densities (1.5, 3.0, 4.5 and 6.0 $kg/m^3$) and fed a commercial diet to apparent satiation for four weeks. In Exp-III, fish ($14.8{\pm}0.1g$) were fed a commercial diet once, twice, thrice, $4{\times}$ or $5{\times}$ a day at a feeding ratio of 3.25% of body mass. Another group of fish was fed the same commercial diet $5{\times}$ a day to apparent satiation; this treatment was designated FS (five times satiation/day). In Exp-IV, fish ($31.3{\pm}0.1g$) were fed a commercial diet once, twice, thrice or $4{\times}$ a day to apparent satiation. Another group of fish was fed to apparent satiation once every 48 hours. In Exp-I, fish fed the large particle (4.0-5.3 mm) diet had a significantly higher feed conversion ratio and lower protein efficiency ratio than fish fed the small particle diet. In Exp-II, groups of fish reared at densities of 4.5 and 6.0 $kg/m^3$ had significantly higher feed intake and growth performance than fish reared at 1.5 and 3.0 $kg/m^3$. In Exp-III, fish fed to apparent satiation had significantly higher growth performances than fish fed once or $4{\times}$ a day. A significantly higher feed conversion ratio and a lower protein efficiency ratio were obtained in the FS group. In Exp-IV, growth performance and feed utilization efficiency were not significantly affected by experimental variation in feeding frequency. Fish fed to apparent satiation once every 48 hours had better feed utilization than those in other treatments and growth performances of those were comparable. Therefore, the optimum feed particle size, stocking density and feeding frequency for Korean rockfish under conditions we used were 2.0-3.2 mm, 4.5-6.0 $kg/m^3$, and once a day or once every 48 hour, respectively.

• Journal of Aquaculture
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• v.21 no.4
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• pp.239-243
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• 2008

A $3{\times}2$ factorial experiment was conducted to investigate the proper dietary protein and lipid levels for the growth of sub-adult flounder Paralichthys olivaceus reared during the summer season. Six experimental diets were formulated to contain three levels of protein (45%, 50% and 55%) and two levels of lipid (9% and 14%). Duplicate groups of fish (initial body weight of 298 g) were hand-fed to apparent satiation during the summer season ($21.8{\pm}1.7^{\circ}C$) for 60 days. Survival of each group was over 83% and there was not significant difference among all groups. Weight gain of fish fed the 45% protein diet with 14% lipid was not significantly different from that of fish fed the 50% and 55% protein diets with 9% and 14% lipids, but weight gain of fish fed the 45% protein diet with 9% lipid was significantly lower than that of fish fed the 55% protein diets with 14% lipid. Feed efficiency tended to increase with increasing dietary lipid level at each protein levels, although no significant differences were observed at 50% and 55% protein levels. Protein efficiency ratio, daily feed intake, condition factor and hepatosomatic index were not significantly affected by dietary protein and lipid levels. Crude lipid content of the liver tended to increase with increasing dietary lipid level at the same protein levels, but the opposite appearance was found for moisture content. The contents of moisture, crude protein and crude lipid of the dorsal muscle were not significantly affected by dietary protein and lipid levels. Based on data obtained form this study, inclusion of dietary protein at level of 45% appears sufficient to support optimal growth, and an increase of dietary lipid level from 9% to 14% has beneficial effects on feed utilization of sub-adult flounder during the summer season.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.759-764
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• 2009

With its rapid growth, the digital contents-related industry is drawing attention as an industry generating a high value added. Specifically, the 3D morphing technology often used in the appearance or movement of each object comprising contents makes it possible to compose various contents by inferring the appearance and movement of the object. For a realistic swimming appearance of fish by using fish that swim in the water, this paper proposes a technique that applies the same speed concept as a physical pendulum to a swimming cycle and applies a frame morphing technique that is able to express the growth process from fry to adult fish. This article is capable of realistically reviving the fish growth process, and can through magnified applying can be applied to in 3D fishes encyclopedias or virtual underwater expressions etc. in the viewpoint which is oceanography.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.3
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• pp.383-390
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• 2014

A 15-wk feeding trial was conducted to examine the supplemental effects of Barodon on growth performance, gastrointestinal histology, feed digestibility and innate immunity in olive founder. A basal commercial diet was used as a control and two other diets were prepared by spraying 0.1% or 0.2% of Barodon. Triplicate groups of fish (BW, 145 g) were fed one of the test diets to apparent satiation twice daily. At the end of the feeding trial, fish growth performance was not significantly affected by dietary treatments; however, feed utilization was significantly improved (linear and quadratic, p<0.05) by Barodon supplementation. Significantly higher (p<0.05) survival rates were obtained in fish fed Barodon containing diets. Hepatosomatic index increased significantly in Barodon treated groups. Also, the use of Barodon resulted in significant increase (linear and quadratic, p<0.05) of intestine length and number of goblet cells. Significantly higher (Quadratic, p<0.05) apparent digestibility coefficient of DM was obtained by supplementation of Barodon. Lysozyme and myeloperoxidase activities increased quadratically and linearly, respectively, in Barodon treated fish. Also, significantly higher (linear and quadratic, p<0.05) superoxide dismutase activity was found in Barodon fed fish. The findings in this study show that inclusion of Barodon in diets for olive flounder improves feed utilization and digestibility, and positively affects digestive tract histology and innate immunity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.4
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• pp.344-348
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• 2009

This study was conducted to investigate effects of dietary lipid level on growth and body composition of juvenile red sea bream in low temperatures. Duplicate groups of fish (initial body weight of 79 g) were fed one of three isonitronic diets (47% crude protein) containing different lipid levels (10%, 17% and 22%) for 25 weeks during the winter season. Weight gain and survival of fish fed 17% lipid diet were significantly (P<0.05) higher than those fish fed the 10% or 22% lipid diet. Protein efficiency ratio, daily feed intake, condition factor, hepatosomatic index and viscerasomatic index were not affected by dietary lipid level, but feed efficiency of fish fed 10% lipid diet was significantly (P<0.05) lower than those fish fed the 17% or 22% lipid diet. Proximate composition of the whole body, liver, viscera and dorsal muscle were not significantly different among all groups except for crude protein content of dorsal muscle. The contents of 16:0, 18:0, 20:4n-3 and 20:5n-3 of the whole body were significantly (P<0.05) affected by dietary lipid level. The results of this study suggest that an increased dietary lipid level from 10% to 17% can improve growth of juvenile red sea bream in low temperature periods.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.648-653
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• 2012

The present study examined the effects of dietary supplementation with nucleotide (inosine monophosphate product, IMP) on the growth performance, feed utilization, and non-specific immune responses of juvenile tilapia Oreochromis niloticus. Triplicate groups of tilapia (initial body weight, $7.4{\pm}0.04$ g) were fed experimental diets containing 0%, 0.05%, 0.1%, and 0.2% IMP. Fish were fed six times a day until apparent satiation for 13 weeks. At the end of the feeding trial, final body weight and food utilization of fish fed 0.1% IMP were significantly higher than those of fish fed the control diet. Results of hematological parameters were not affected by dietary IMP. However, blood protein level was significantly higher in the 0.05% treatment, as compared to that of the control and 0.2% IMP diets. Myeloperoxidase activity was higher in fish fed 0.1% IMP than in fish fed the control and 0.2% IMP diets. These results suggest that dietary supplementation with IMP can enhance the growth performance, feed utilization, and innate immune response of juvenile tilapia. The optimal IMP supplementation level appears to be 0.1% in practical feed formulations for tilapia.