• Fisheries and Aquatic Sciences
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• v.8 no.3
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• pp.128-131
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• 2005

The effects of alternate-week feeding strategies on growth and feed efficiency ratio of juvenile Nile tilapia were investigated in a recirculating aquaculture system. Twenty fish initially weighing 25.5 g were randomly distributed into each of 18 tanks to conduct three replicates for each of six different feeding strategies. Weight gain of fish in the control that were fed daily for 6-week feeding trial was significantly higher than those of fish subjected to various alternate-week feeding regimes. Weight gain of fish that were starved for 3 weeks and then fed daily for 3 weeks (3WS+3WF) was not significantly different from that of fish, starved and fed daily for alternate 1-week period during the trial (1WS+1WF), but was significantly higher than those of fish starved for 2 weeks, and fed for 2 weeks (2WS+2WF); fish starved for 4 weeks and fed for 2 weeks (4WS+2WF); and fish fed for 5 weeks and fed for 1 week (5WS+1WF.) The amount of feed supplied to fish in the groups of 1WS+1WF and 3WS+3WF was significantly lower than that fed to fish in the control group, but significantly higher than the amount feed supplied to fish in the other three groups. Feed efficiency ratio for fish in the control group did not differ from that for fish in the groups of 1WS+1WF, 2WS+2WF and 3WS+3WF, but was significantly higher than that for fish in the groups of 4WS+2WF and 5WS+1WF. In conclusion, juvenile Nile tilapia that were subject to starvation for 1 to 5 weeks did not exhibit compensatory growth sufficient to attain the same weight as fish fed daily for 6 weeks. In addition, fish subjected to starvation exhibited low feed efficiency ratio compared to fish fed daily, which were probably attributable to poor weight gain.

• The Journal of Fisheries Business Administration
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• v.34 no.2
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• pp.53-73
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• 2003

This paper is to analyze the past and present consumption pattern of fishes aquacultured in marine waters and thus to draw the policy direction to enhance the competitiveness of marine fish aquaculture in Korea. At present, the volume of meat consumption is surveyed to be more than that of marine fish, but it is revealed that fish consumption will become more increasing in the future according to the rise of the income. The survey shows that the consumption of fish is highest in the fall, and among the various patterns of consumption, live fish, so-called susi, is surveyed to be highly dominant. It is revealed that fish is enjoyed because of the special savor, diverse nutrients, and the prevention of adult diseases. Natural fish Is revealed to be more preferred to aquacultured one due to the sticky flesh quality and the low probability of the remained after the production process antibiotics, so that it is necessary to enhance the taste quality and make a clean cultivation to capture more market demand. Consumption of high-quality fish seems to become high in more than middle class and consumption of fish are estimated to increase in the future, more than that of meat if income level of the people increases. Also, if we try to make our high-quality fish become popular among the public and competible with the imported fish from abroad, it is recommended that they must lower production price by cost reduction and try to differentiate it by taste and environmental safety, etc. It was revealed that the significant factor in demand function for fish is income and it is almost the only factor affecting that demand. Also, it was revealed that the most significant factor affecting preference of fish is income and it Is almost the only factor affecting the preference. Therefore, we can ascertain that if proper goods can be distributed, demand for and preference of fish may increase according to the increase of income in the future.

• Journal of Korean Academy of Nursing
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• v.19 no.3
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• pp.299-306
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• 1989

In order to evaluate the effect of fish oil on lipid drogenase(G6PDH), malic enzyme(ME), glucose-6-phosphatase(G6Pase) activities were measured in liver and adipose tissue of rats fed 13 days supplemented fish oil at the level of 10% (W/W). Two other groups of rats were fed 10% soybean oil or lard to compare with the effect of fish oil. In all groups, activities of hepatic G6PDH and ME were depressed from the beginning of feeding. This effect was greatest (50%) in fish oil group. Hepatic G6Pase was highest in rats fed lard. When the level of fish oil was reduced to half, as total fat content was maintained at the level of 10% by complementary lard, lipogenic enzyme depressing effect of fish oil was as significant as shown in 10% fish oil diet. Hepatic G6PDH was depressed significantly(14%) in rats fed fish oil as low as 2％. On the other hand, changes in adipose tissue G6PDH and ME activities were small. Adipose tissue G6Page activity increased slightly in rats fed with increasing fish oil(above 0.5%). It is suggested that fish oil alter, more markedly than either soybean oil or lard, cellular lipid metabolism by reducing activities of hepatic lipogenic enzymes.

• Journal of the Korean Society of Food Culture
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• v.31 no.4
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• pp.357-363
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• 2016

The principal objective of this study was to evaluate the utilization of fish paste with added Capsosiphon fulvescens powder were 0, 3, 5, and 7%. The moisture, crude protein, crude lipid, crude ash and carbohydrate contents of the used Capsosiphon fulvescens powder were 8.5, 33.2% 1.1, 9.6, and 47.6%, respectively. For the Hunter color values, the L, a values of the fish paste decreased with increasing concentrations of Capsosiphon fulvescens powder. The b values of the fish paste appreciation with increasing concentrations of Capsosiphon fulvescens powder. And the folding test which represent the flexibility of the fish paste, all test samples showed AA. In the texture meter test, the hardness, strength, cohesiveness, and springiness increased according to increasing concentrations of Capsosiphon fulvescens powder. However, the gumminess and brittleness of the fish paste reduced by the addition of Capsosiphon fulvescens powder. In the sensory evaluation, color and taste of the fish paste were preferred 5% Capsosiphon fulvescens powder and the fish paste prepared with 5% Capsosiphon fulvescens powder were preferred over other fish pastes. These results suggest that Capsosiphon fulvescens powder can be applied to fish paste for the purpose of high quality and functionality.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.129-146
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• 1998

Fatty acid compositions of seventy-two species of Korean fish muscle, 59 species of sea water fish and 13 species of fresh water fish, were studied. Polyunsaturated fatty acid (PUFA) was the richest fatty acid group in all fish samples, accounting for $38.0\pm10.3\%$ of total fatty acids. Monounsaturated fatty acids $(MUFA,\;31.4\pm9.67\%)$ and saturated fatty acids $(SFA, 30.5\pm3.81\%)$ showed a similar level. There was a positive correlation between the total lipid content and MUFA (r=0.7788, p<0.001) and a negative correlation between the total lipid content and PUFA (r= -0.7786, p<0.001) while there was no correlation between the total lipid content and SFA. The proportion of n-3 PUFA and n-6 PUFA was $29.7\pm8.73\%$ and $6,48\pm3.70\%$, respectively, in all fish samples. The n-3 PUFA was rich in sea water fish while n-6 PUFA was rich in fresh water fish. The migratory fish contained the highest level of the n-3 PUFA $(1.82\pm1.01g/100g\;muscle)$, followed by the fresh water fish $(1.09\pm1.04g/100g\;muscle)$, the reef fish $(0.90\pm0.60g/100g\;muscle)$ and the demersal fish $(0.77\pm0.38g/100g\;muscle)$. There was a positive correlation between the total lipid and n-3 PUFA content, $y=0.2083\times+0.05 (r=0.9352,\;p<0.0010)$.

• Proceedings of the Korean Aquaculture Society Conference
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• 2005.05a
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• pp.92-92
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• 2005

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.3
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• pp.282-286
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• 2013

This study was conducted to compare extruded pellets (EP) and soft extruded pellets (SEP) with a raw fish-based moist pellet (MP) diet on the growth and flesh quality of Korean rockfish Sebastes schlegeli. Three groups of 20,000 fish (initial mean weight 133 g) per net-cage ($6{\times}12{\times}7m$) were fed commercial EP, SEP or MP for 16 months. The survival of fish fed SEP was higher than those of fish fed EP or MP. The highest growth performances were observed in the mean weight gain, total weight gain, and feed efficiency of fish fed MP, followed by those fed EP and SEP. Among the fish fed on extruded pellets, the total weight gain of fish fed SEP was higher than that of those fed EP, while fish fed EP grew faster than those fed SEP. No notable differences in body composition, sensory scores or textural properties of the dorsal muscle were observed in fish fed on EP, SEP or MP. Thus, it is suggested that extruded pellets, rather than raw fish-based moist pellets, could be fed to Korean rockfish without compromising flesh quality.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.849-856
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• 2009

In this study, dietary supplementations of Korean Meju, fermented soybean meal (F-SBM) by Aspergillus oryzae, and A. oryzae itself were evaluated on growth performance, feed utilization, immune responses and phosphorus availability in juvenile parrot fish, a marine aquaculture fish species. Four isonitrogenous and isocaloric diets were formulated to contain 8% soybean meal (control diet), 4% Meju (50% soybean meal was replaced by Meju), 4% F-SBM (50% soybean meal was replaced by F-SBM), or 0.08% A. oryzae itself. One of the four experimental diets was fed to triplicate groups of fish for 8 weeks. At the end of the feeding trial, no significant differences were found in growth performances and feed utilization. Red blood cell counts in the fish fed the A. oryzae diet were significantly higher than that of fish fed the control diet. The antioxidant activity in Meju diet was significantly higher than that of the control and A. oryzae diets. Fish fed Meju and F-SBM diets showed numerically higher antioxidant activity of serum compared to that of fish fed the control diet, even though it was not significant. Liver superoxide dismutase activity of fish fed the test diets was significantly higher than that of fish fed the control diet. The apparent digestibility coefficients of protein of fish fed all the diets were not significantly different. Phosphorus absorption was numerically increased in fish fed F-SBM and A. oryzae diets compared to that of fish fed the control diet. This study indicates that the fermentation process of soybean meal does not impair growth performance and feed utilization in parrot fish. The fermentation process could enhance the availability of phosphorus in soybean meal and non-specific immune responses of parrot fish.

• Fisheries and Aquatic Sciences
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• v.22 no.4
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• pp.8.1-8.9
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• 2019

A 12-week feeding trial was designed to evaluate the effect of total replacement of fish oil (FO) with terrestrial alternative oils on growth, feed utilization, body composition, hematological parameters, and fillet fatty acid profile of mandarin fish juveniles. Four iso-nitrogenous (56% crude protein) and iso-lipidic (13% crude lipid) practical diets were formulated. A control diet contained 6% FO and three other experimental diets were prepared by replacing FO with linseed oil, soybean oil, and lard (designed as FO, LO, SO, and lard, respectively). Each diet was randomly allocated to triplicate groups of 25 fish ($1.8{\pm}0.03g/fish$) in a circular tank. Complete replacement of FO by three tested alternative oils had no remarkable impact on growth performance, feed utilization efficiency, and morphological and hematological parameters of juvenile mandarin fish. However, daily feed intake was found to be significantly higher for fish fed the SO diet compared with those fed the FO and LO diets. Fish fed LO and SO diets exhibited significantly higher levels of the whole body lipid compared to fish fed diet containing FO. Fillet fatty acid composition reflected dietary fatty acid profile. The highest level of ${\alpha}$-linolenic acid, linoleic acid, and oleic acid was observed in fish fillet fed LO, SO, and lard, respectively. Although the eicosapentaenoic acid level of fish fillet fed diet FO was higher than other treatments, no significant difference was found in docosahexaenoic acid content among all dietary groups. The results of the present study clearly demonstrate that the complete replacement of FO in mandarin fish diets is achievable. These findings are useful in dietary formulation to reduce feed costs without compromising mandarin fish growth.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.403-412
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• 2011

Hydroacoustic surveys were performed to clarify the density and spatial distribution of fish upstream and downstream of Changzhou Dam in the Pearl River, China, with regard to the condition of the spillways. Fish were densely distributed in the forebay of the upstream dam and the average fish density was 0.22 individuals/$m^3$ under open spillways on 24 June 2010, but when the spillways were closed on 25 June 2010, the fish in the upstream dam dispersed and the average fish density decreased to 0.007 individuals/$m^3$. Meanwhile, the average fish density in the downstream region was 0.28 individuals/$m^3$ before the spillway was opened on 24 May 2010, but it decreased to 0.08 individuals/$m^3$ on 26 June, just after the spillway was closed. The vertical distribution of fish upstream of the dam was not consistent. The target strength (TS) of fish upstream of the dam was larger than that of fish in the downstream region, although the distribution of TS was similar between the upstream and downstream regions. Therefore, we concluded that while numerous fish could swim to the upstream region while the spillways were open, closed spillways obstructed fish migrating upward from the downstream region.