• Journal of Aquaculture
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• v.17 no.4
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• pp.275-281
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• 2004

The present study was conducted to evaluate dietary requirements for essential fatty acids (EFAs) such as linoleic acid (LA, l8:2n-6), -lenolenic acid (LNA, 18:3n-3), or docosahexaenoic acid (DHA, 22:6n-3), eicosapentaenoic acid (EPA, 20:5n-3) and arachidonic acid (ARA, 20:4n-6) in juvenile eel Anguilla japonica cultured in a recirculating system for 16 weeks. The experimental diets contained 50% crude protein, 10% crude lipid and 3800 kcal/kg energy.Brown fish meal and blood meal were used as the main protein sources, while coconut oil, com oil and linseed oil were used as the lipid source to yield target fatty acids ratios. At the end of the trial, the effects of essential fatty acids supplementation on weight gain (WG), specific growth rate (SGR), feeding efficiency (FE), proximate composition andwhole body fatty acids contents were examined. WG, SGR, and FEof eels fed diet D2, D3, was significantly higher (P<0.05) than those of fish fed the other diets. Whole body HUFA concentration of eels fed D 1 was significantly lower (P<0.05) than those fed the other diets. HUFA/SFA (saturated fatty acids) ratio of whole body in eels fed diets D2, D3 and D6 were significantly higher than that of eels fed diet D1 (P<0.05).DHA/EPA ratio of whole body in eels fed diet D7was significantly higher than those fed the other diets; and eels fed diet D5 showed the lowest DHA/EPA ratio among all the dietary treatments (P<0.05).Based on the experimental results, we concluded that LNA (n-3) and LA (n-6) were necessary for optimum growth of juvenile eel, and the dietary requirement of LNA and LA were 0.35∼0.5% and 0.5∼0.65%, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.93-97
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• 2000

This study was carried out to investigate the effect of rotifer fed the different diets in high density culture on larval flounder Paralichthys olivaceus. Potifer was enriched with enrichment supplements, Marine ${\alpha}\;and\;{\omega}-yeast$ for 6 hours after being cultured with freshwater Chlorella for 18 hours during high density culture before it was fed to larval flounder. And rotifer was culutured with marine Chlorella and freshwater Chlorella for 24 hours during semi-continuous high density culture before it was fed to larval flounder. Culture tanks(21 working volum) set for rotifer culture in a water bath($28{\circ}C$) were continuously supplied with oxygen gas. The content of n-3 HUFA to fatty acids in rotifer(dry weight ${\%}$) enriched with Marine ${\alpha}$ for 6 hours and cultures with marine Chlorella for 24 hours were higher than that in rotifer enriched with ${\omega}-yeast$ for 6 hours or cultured with freshwater Chlorella for 24 hours. The growth and survival rates of larval flounder fed on rotifer enriched with Marine ${\alpha}$ for 6 hours and cultured with marine Chlorella for 24 hours were higher than those of larval flounder fed on rotifer enriched with ${\omega}-yeast$ for 6 hours or cultured with freshwater Chlorella for 24 hours. And the content of n-3 HUFA of larval flounder fed on rotifer enriched with Marine ${\alpha}$ for 6 hours was higher than that of larval flounder fed on other rotifers, The results from this study indicated that rotifer culture with marine Chiorelia would be suitable for the high density culture and effective diet for the growth of larval flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.748-752
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• 1999

This study was carried out to compare the growth and fatty acids composition of the rotifer (Brachionus rotundiformis) cultured in high density by the various enrichments and culture methods. The rotifer fed on condensed freshwater Chlorella was enriched with $\omega$-yeast, Algamac, Super Selco and marine Chlorella. In another culture method, the rotifer was cultured with enrichment supplements for 6 hours after feeding with condensed freshwater Chlorella supplement for 18 hour. The rotifer fed with condensed marine Chlorella for 24 hours without fieshwater Chlorella was used as a control group. Culture tanks (5 $\ell$ working volume) was immersed in a water bath ($28^{\circ}C$). The density of rotifer and dissolved oxygen level in water was stable in control group of rotifer cultured with condensed marine Chlorella for 24 hours and the n-3 HUFA content of rotifer was the highest among the rotifer culture methods. However, the density of rotifer and dissolved oxygen level in the groups of rotifers enriched with $\omega$-yeast, Algamac and Super Selco by methods were drastically decreased, The n-3 HUFA contents of rotifers enriched by Super Selco were higher than those of rotifer enriched by either $\omega$-yeast or Algamac in both methods. The results from this experiment indicated that supplementation of condensed marine Chlorella for 24 hour by the semi-continuous culture was effective for the improvement of the nutritional value of rotifer and it could provide the stable growth condition for rotifer culture in high density.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.4
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• pp.183-186
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• 2007

The effect of live food and commercial diet on sweetfish Plecoglossus altivelis culture was assessed by determining the daily growth rate and feed conversion ratio. After feeding for 8 weeks, the Moina macrocopa diet resulted in a higher growth rate of 5.101 compared to commercial (3.441) and Artemia (2.729) diets. In addition fish fed the M. macrocopa diet had the weight gain, averaging 41.29 g at the end of the experiment. The content of n-3 highly unsaturated fatty acids (HUFA) was highest in the commercial diet, while free fatty acids were not detected in the M. macrocopa diet. Triglycerides, the energy source in fishes, constituted 40.0% of the M. macrocopa diet, which was significantly higher than in the commercial and Artemia diets at 20.0 and 12.0%, respectively These results indicate that freshwater M. macrocopa can be used as feed for sweetfish larvae, even without docosahexaenoic acid (DHA) enrichment from Artemia.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.798-802
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• 1999

This study was performed to compare the effect of enrichement of rotifer and Artemia fed marine bacteria (Erythrobacter sp. S$\pi$-1) with those fed the different diets-(Super Selco, $\omega$-yeast and marine Chlorella) on the slime flounder larvae, Microstomus achne. Because the ratio of docosahexaenoic acid (DHA) to fatty acids in rotifer (dry weight $\%$) fed on Super Selco and ESP-SR including Erythrobacter sp. S$\pi$-1 was higher than that in rotifer fed marine Chlorella, the growth of the slime larvae fed the former showed better than the latter. And the ratio of DHA and highly unsaturated fatty acid (n-3 HUFA) to fatty acids in Artemia (dry weight $\%$) enriched by ESP-A including Erythrobacter sp. S$\pi$-1 were also higher than those in Artemia enriched by others or Artemia without enrichment. Larvae fed on Artemia enriched by ESP-A showed better growth and survival rate than those fed on Artemia enriched by others or Artemia without enrichment. With regard to dietary value of Erythrobacter sp. S$\pi$-1, its use could improve the quality of the live foods for the slime flounder larvae.

• Journal of Life Science
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• v.28 no.12
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• pp.1424-1431
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• 2018

We prepared flocculated detritus-like organic marine snow originating from various organisms by fermentation using microorganisms; this fermented organic material was fed to the leptocephali of the eel (Anguilla japonica) to investigate whether or not such organic matter was an appropriate food source for the larvae. A strain was isolated from a biofloc technology system used to culture fish, and seven types of organic material from hen's egg, eel muscle, tuna muscle, lugworm, shrimp, manila clam, mussel, and sea squirt were fermented using isolated bacteria (Bacillus sp.). The fermented matter did not show any specific form and was larger than $10-20{\mu}m$ but no more than $100{\mu}m$ in size. Four diets (A-D) were prepared using the various fermented products, and the larvae were fed the prepared food from 20 days after hatching. The leptocephali fed the A, B, and C diets survived until 37, 39, and 37 days after hatching, respectively. However, the leptocephali fed the D diet survived for 60 days after hatching. The protein content of each diet was very similar, but the n-3 HUFA concentration in the D diet was approximately twice as high as that of the others.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.390-398
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• 2014

We conducted an 8-week feeding trial to evaluate dietary lipid sources on the growth performance and body composition of juvenile river puffer fish Takifugu obscurus. Nine experimental diets were formulated with fishmeal as the major protein ingredients, providing 50% crude protein. The experimental diets contained either beef fallow (BF), soybean oil (SO), rapeseed oil (RO), or linseed oil (LO). Each of these diets was then supplemented or not with 0.5% n-3 HUFA (BFH, SOH, ROH, and LOH), resulting in a total of eight experimental diets. The control diet contained fish oil (FO) as the lipid source. Fish averaging $10.3{\pm}0.03g$ were fed the experimental diets in randomly selected triplicate groups for 8 weeks. Weight gain and feeding efficiency of fish fed the FO and SOH diets were significantly higher than those of fish fed BF or RO (P<0.05), but these diets did not differ significantly from the other diets. The protein efficiency ratio of fish fed the SOH diet was significantly higher than that of fish fed the BF, SO, or RO diets (P<0.05), but these were not significantly different from the other diets. The specific growth rate of fish fed the FO and SOH diets was significantly higher than that of fish fed the BF diet (P<0.05). Whole body DHA and n-3 HUFA contents of fish fed the FO diet were significantly higher than those of fish fed the SO, RO, or LO diets (P<0.05), but were not significantly different from the other diets. These results indicate that soybean oil and linseed oil could replace up to 100% of fish oil in the diet containing 60% fishmeal for river puffer fish.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.2
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• pp.154-160
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• 2016

Several our studies have focused recently on the mass production of the freshwater Cladoceran Moina macrocopa which can substitute Artemia nauplii for the culture of larval marin fish. A 6 weeks experiment was conducted to investigate the effects of enrichment on the fatty acid composition of Moina macrocopa through feeding Schizochytrium sp. containing highly unsaturated fatty acids and to study the impacts of n-3-HUFA enriched Moina on improving survival rate and fatty acid compostion of larval rockfish Sebastes schlegeli. After feeding for 6 weeks, the Moina-fed fry resulted in a higher survival rate of 99.2% compared to the Artemia-fed fry 12.8%. In addition, the Moina-fed fry had the fast growth rate 45.6mm compare to the Artemia-fed fry 25.7 mm at the end of the experiment. The Moina-fed fry showed significantly higher level of 16.47% DHA than their Artemia-fed fry counterparts of the level of 3.97% with respect to DHA. PL, the cell membrane components in living food organisms, constituted 63.8% of the Moina, which was significantly higher than in the 40.1% of the Artemia. The present study indicate that Moina macrocopa can be used as Artemia substitute and improving the survival rate rockfish larvae through enchriment Schizochytrium sp.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.682-687
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• 2018

This study investigated the food value of Paracyclopina nana for flounder Paralichthys olivaceus larvae in two feeding stages, rotifer (for 12 days) and Artemia (for 16 days). In the rotifer feeding stage, survival and growth of flounder larvae in the only P. nana (nauplii) feeding experiment were higher than in the only rotifer feeding experiment on 12 DAH (days after hatching). In the Artemia feeding stage, the growth of flounder larvae in the only P. nana (C4-adult) feeding experiment and mixture feeding experiment (P. nana+Artemia) were higher than in other experiments on 30 DAH, but the survival of flounder larvae did not differ significantly among experiments. The n-3 HUFA contents of nauplius and C4-adult were 4.0% and 5.4%, respectively. Overall the results of this study indicate that the brackish water cyclopoid copepod, P. nana, is an effective live food organism for larval seedling production of marine fish.

• Journal of Aquaculture
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• v.11 no.3
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• pp.381-390
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• 1998

Three feeding experiments were carried out to evaluate the effects of fatty acids or lipid sources in diets on the survival, growth and body composition of junenile abalone(Haliotis discus hannai). Diets used in this study contained casein or fish meal as a protein source. Three replicate groups of abalone averaging 160 mg were fed with casein diets containing 12:0, 18:1, 18:2n-6, 18:3n-3, n-3HUFA, squid liver oil (SO), corn oil (CO), beef tallow (BT), SO+CO, and SO+BT, or fed fish meal diets containing SO, CO, BT, SO+CO, SO+BT and not supplemental oil for 20 weeks, respectively. Survival rate, weight gain and soft body weight of abalone were not significantly affected by different fatty acids in the casein diets (P>0.05). Weight gain, soft body weight and shell length of abalone fed the casein diets containing SO, SO+CO or SO+BT were significantly higher (P<0.05) than those of abalone fed the casein diets containing CO or BT. Survival rate of abalone fed the fish meal diets was not influenced by different lipid sources (P>0.05). Weight gain and soft body weight of abalone fed the fish meal diets containing beef tallow (BT or SO+BT diet) were lower than those of abalone fed the diet not added oil or diets containing SO, CO and/or SO+CO(P<0.05). These data indicated that SO or SO+CO was good dietary lipid source for juvenile abalone, and that these oil supplement in diet was not necessary when fish meal was used as a protein source.