• Journal of Aquaculture
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• v.7 no.1
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• pp.63-76
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• 1994

The effects of different dietary lipids on growth, body chemical composition, and nutrient partition of the Korean rockfish (43 g of initial mean weight) were studied. Fish were fed three experimental diets containing 1) $4.5\%$ squid liver oil, 2) $1\%$ squid liver oil and $3.5\%$ beef tallow, and 3) $1\%$ squid liver oil and $3.5\%$ soybean oil. Growth and feed efficiency were detarmined during a 19-week feeding period at water temperature of $15.5^{\circ}C$, and at the end of which body chemical compositions were analyzed. Remained fish were fasted for 45 days, and four fish were taken at 6, 12 and 24 hours, and 3, 15 and 45 days after the fasting to determine tissue compositions and hematological changes. Growth, feed efficiency, protein and lipid retention efficiency, hepatosomatic index(HSI), viscerosomatic index (VSI), and chemical composition of whole body and dorsal muscle were not affected by the different dietary lipids. Liver moisture content of fish fed squid liver oil diet was higher than that of fish fed beef tallow or soybean oil diet. Liver lipid content of fish fed beef tallow diet was higher than that of fish fed the other diets. Fatty acid composition of dorsal muscle and liver were affected by the different dietary lipids ; high levels of 20 : 5n-3 and 22 : 6n-3 from fish fed the diet containing squid liver oil, 18 : 1 from fish fed the diet containing beef tallow, and high 18 : 2n-6 and 18 : 3n-3 from fish fed the diet containing soybean oil were observed. Both HSI and VSI of fish fed three diets decreased with time after the begining of starvation. Liver glycogen did not change during the first 15 days of starvation and decreased thereafter, and that was not affected by the different dietary lipids. Lipid and protein contents in the dorsal muscle of fish decreased up to 15 days of starvation and remained unchanged thereafter, these were not different from each other. Glucose, free fatty acid, triglyceride and phospholipid concentrations in Fish serum were varied for the first 15 days of starvation, after that the concentrations of fish serum remained relatively stable in all the treatment groups with prolonged starvation. The results indicate that Korean rockfish can utilize fish oil, animal fat or vegetable oil equally as energy source when n-3HUF A is adquate.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.4
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• pp.317-325
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• 1990

The attraction activity of the natural baits for sea eels(Astroconger myriaster) was surveyed by using fishing traps in the 3 different fishing ground of southern coastal waters of Korea. Twenty four different baits were experimented and weight for each bait was 50g, the optimal minimum weight owing to our preliminary test. Among the above 24 baits, anchovy(Engraulis japonica), sardine(Sardinops melanosticta), or marine worms(Neanthes japonica)were most effective. In case of sardine bait, the body showed higher attraction activity than the head or viscera and the builded juice of anchovy or sardine showed higher attraction activity than spoiled one.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.339-344
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• 2011

We investigated the effects of enrichment with oil or bacteria on the fatty acid composition of rotifers and Artemia as live prey. One enrichment(oil source) was mainly composed of squid Todarodes pacificus liver oil; the other(photosynthetic-bacterial source) was primarily made up of Schizochytrium sp. The enrichments were intended to enhance the nutritional value of the live prey, such as their EPA, DHA and n-3 HUFA contents. The lipid content as EPA and DHA of rotifers was higher when enriched with the oil source rather than the photosynthetic-bacterial source. The DHA content of Artemia nauplii after enrichment differed significantly, depending on the type of enrichment used(P<0.05). When the Artemia nauplii were enriched with the oil source, the DHA content was increased to 16.8%, whereas it increased only to 1.1% when enriched with the photosynthetic-bacterial source. These results indicate that selection of the enrichment is important for Artemia nauplii but not for rotifers.

• Journal of Aquaculture
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• v.13 no.3
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• pp.197-206
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• 2000

At the Poryoung coast, the spawning season of the mullet, Chelon lauvergnii lasts from May to June. A combination of rotifer, Rotifer nauplii and synthetic feed supported significantly (P < 0.05) better survival and growth of 1-day old mullet larvae during 70-day rearing experiment than the other feeds consisting of rotifer or rotifer + Artemia nauplii. Significantly higher growth and survival were also observed, when the larvae were fed on rotifer, that were harvested from culture enriched with masimaTR, or Artemia nauplii from culture enriched with cuttlefish liver oil, At the feeding density of 97-98 individuals /200 l, the mullet larvae displayed maximum growth and survival in aquarium each with 100 larvae /200 l.

• Journal of Aquaculture
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• v.10 no.4
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• pp.417-424
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• 1997

This study was carried out to investigate the effects of experimental formulated diets, commercial diets and natural diet(dried Undaria) on growth and body composition of Haliotis discus hannai. Experimental diets was formulated to provide 34.1% protein and 7.5% lipid, and prepared by different $CaCl_2$ concentration (5, 10 and 15%) and dipping time (10, 20 and 60 second) in solution. The juvenile abalone average weighing 0.3g were distributed in a flow-through aquarium system using a cmpletely randomized desing with 13 diets and 3 replictes per diet (50 abalone/tank), and fed diets for 17 weeks. The abalone fed the time nine experimental formulated diets and two commercial diets showed better growth performance than that of natural diets. No significant differences were found among abalone fed the experimental diets and commercial diets in survival rate, weight gain, soft body weight and soft body composition (P>0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.745-750
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• 2014

This study investigated the effects of squid Todarodes pacificus liver oil on the serum lipids and adipose tissue weight of rats. The rats in the soybean oil (SO) group received a basic diet prepared according to the recommendations of the American Institute of Nutrition (AIN-93G), with 7% SO as lipid source. The rats in the Patagonian toothfish Dissostichus eleginoides muscle oil (PTFO) group received 5% PTFO and 2% SO as the lipid source, while the rats in the eco-friendly squid liver oil (EFSO) group received 5% EFSO and 2% SO. EFSO was prepared according to the method outlined in the author's patent. PTFO was extracted from muscle using a physical method in the author's laboratory. The prominent polyunsaturated fatty acids in the dietary oils were 18:2n-6 (54.3%) and 18:3n-3 (5.64%) in SO, DHA (6.77%) and EPA (3.61%) in PTFO, and DHA (26.2%) and EPA (9.94%) in EFSO. After feeding for 4 weeks, the serum lipid levels (e.g., triglyceride, total cholesterol, and low-density lipoprotein cholesterol) of the rats in the EFSO group were significantly reduced as compared with those in the SO group (P<0.05); those of the rats in the PTFO group were also reduced, albeit not significantly, compared with the SO group. On the other hand, the total white adipose tissue (visceral, epididymal, and perirenal) weight was significantly reduced in the EFSO and PTFO groups compared to the SO group. These results demonstrate that EFSO is an effective lipid modifying agent in rat blood, and that EFSO and PTFO have greater anti-obesity effects than SO.

• Journal of Aquaculture
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• v.6 no.2
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• pp.89-105
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• 1993

In order to investigate the effects of dietary n-3 highly unsaturated fatty acids (n-3HUF A) levels on growth and body composition of the Korean rockfish, six experimental diets with various levels of n-3HUFA, which were adjusted by adding squid liver oil and/or soybean oil at $8\%$ dietary lipid level, were fed to the Korean rockfish (6.2g in mean body weight) for 10 weeks. Daily weight gain, feed efficiency and nutrient retention efficiency were the lowest in the fish fed a diet containing 0% n-3HUFA. These parameters were effectively improved by supplementation with n-3HUFA, and showed linear increase up to $1.2\%$ dietary n-3HUFA level (P<0.01). There was no additional response above this level. A higher concentration of nonpolar lipids in the liver was observed for the fish fed insufficient levels of n-3HUFA in the diets. However the liver glycogen content and hepatosomatic index were slightly deareased. The lipid contents of the whole body and vicera showed significantly higher in the fish fed sufficient levels of n-3HUFA in the diets (P<0.05). The fatty acid compositions of polar lipids in the whole body and liver were affected by dietary fatty acid compositions. The contents of n-3HUFA and 18:1 in the liver increased with increasing the n-3HUFA level in the diets, while the 18:2n-6 and 18: 3n-3 decreased. These results suggest that n-3HUFA plays an essential role for normal growth of the Korean rockfish, and the requirement of n-3HUF A is around $1.2\%$ of the diet.

• Journal of Aquaculture
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• v.21 no.2
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• pp.82-88
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• 2008

A 12-week feeding trial was conducted to investigate the effects of dietary supplementation of probiotics as a feed additive for juvenile Korean rockfish Sebastes schlegeli. Four experimental diets supplemented with no probiotic(Control), Bacillus polyfermenticus(BP), Bacillus licheniformis(BL) or Bacillus polyfermenticus plus Saccharomyces cerevisiae(BP+SC) at $1.0{\times}10^7$ CFU/kg diet as a dry-mater(DM) basis were prepared by mixing with a basal diet. After 12 weeks of the feeding trial, fish fed BP+SC diet showed significantly higher weight gain(WG), feed efficiency(FE), specific growth rate(SGR) and protein efficiency ratio(PER) than those of fish fed control diet(P<0.05), however there were no significant differences in WG, FE, SGR and PER among fish fed the BP, BL and BP+SC diets. Fish fed BP and BP+SC diets showed significantly higher condition factor(CF) than that of fish fed control and BL diets. Fish fed BP, BL, BP+SC diets showed significantly higher hepatosomatic index(HSI) than that of fish fed control diet, however there was no significant difference in HSI among fish fed BP, BL and BP+SC diets. Fish fed BP+SC diet showed significantly lower serum glucose than that of fish fed control diet, however there was no significant difference in serum glucose among fish fed BP, BL and BP+SC diets. Fish fed BP+SC diet showed significantly higher respiratory burst activity(NBT assay) than that of the fish fed control and BL diets, however there was no significant difference in NBT assay between fish fed BP and BP+SC diets. Fish fed BP and BL diets showed significantly higher lysozyme activity than that of the fish fed control diet, however there was no significant difference in lysozyme activity among fish fed BP, BL and BP+SC diets. Fish fed BP and BP+SC diets showed significantly lower cumulative mortality than that of the fish fed control diet, however there was no significant difference in cumulative mortality among fish fed BP, BL and BP+SC diets after the challenge test. From these results, dietary B. polyfermenticus, B. licheniformis and B. polyfermenticus plus S. cerevisiae supplementation in juvenile Korean rockfish diet could enhance growth performances, non-speicific immunities and a higher resistance against the specific pathogen.

• 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.