• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.365-370
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• 2013

This study investigated the effect of dietary paprika on the skin coloration of red- and white-colored fancy carp Cyprinus carpio var. koi, in two age groups: 0-age ($7.4{\pm}0.1$ g/fish) and 1-age ($164{\pm}2.9$ g/fish). Three isonitrogenous diets were formulated to contain 0, 5, and 10% paprika (Con, P5 and P10, respectively). Three replicate groups of 0-age fish and two replicate groups of 1-age fish were fed one of the experimental diets for 9 weeks. Survival, weight gain, and feed efficiency were not significantly affected by the dietary paprika level (P>0.05) at both fish sizes. The dietary paprika level influenced the redness ($a^*$), lightness ($L^*$), and yellowness ($b^*$) of fish skin. The $L^*$ value of the skin of the fish fed the P5 and P10 diets tended to decrease with feeding period. The skin $a^*$ value of 0-age fish (small) fed the diets containing paprika increased significantly with feeding period and was higher than that of fish fed the control diet after 3 weeks (P<0.05). However, the $a^*$ value of 1-age fish (large) fed the diets containing paprika tended to increase slightly with feeding period. At the end of the experiment, the skin total carotenoid level was increased significantly in fish of both sizes fed the P5 and P10 diets compared to fish fed the control diet. Therefore, 5% paprika powder in the diet increases the skin redness of red- and white-colored fancy carp, especially in small fish.

• Culinary science and hospitality research
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• v.19 no.5
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• pp.158-169
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• 2013

Finespotted flounder, used for a representative raw fish in spring, is considered comparatively difficult to breed, which causes small Olive flounder and Stone flounder from China, similar kinds of flounders, to appear on the market for sale under the name of 'Finespotted flounder.' The reason lies under the considerations that small Olive flounder and Stone flounder from China are relatively lower priced and in higher supply and demand, being difficult to distinguish from Finespotted flounder when sliced with bones. Thus, the purpose of our thesis is to distinguish Finespotted flounder from similar kinds of fish analyzing the lipid content in slices of raw fish and SDS-PAGE(sodiumdodecylsullipide-polyacrylamide gel eletrophoresis). Upon comparing the main components between sliced Finespotted flounder and similar kinds of fish, such as small Olive flounder and Stone flounder from China, we found that there are no noticeable differences among them in moisture content, and little, if any noticeable differences, in crude protein and ash content(P>0.05). Based on these analyses, we have conclude that commercial raw fish restaurants sell small Olive flounder and Stone flounder under the name of Finespotted flounder. However, a variety of factors have an effect on our analysis, such as the individual characteristics of fish and a seasonal variation. The aim of our analysis is to enhance more accurate distinction criteria, although some fish kinds can be discerned with our present technique of examining lipid content and SDS-PAGE. Through more sophisticated analyses developed by consistent research, we look forward to attaining more accurate techniques for discerning between Finespotted flounder and different kinds of similar fish.

• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.310-318
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• 2001

In the large regulated Nakdong River, the Predation effect of juvenile fish on the zooplankton community was evaluated by gut and stomach analyses of fish in 1999. Juvenile fish of five species showed high density from May to early June when river discharge was low and water body became stagnant. During this period, large rotifers, Asplanchna spp. and Brachionus spp. declined and the decrease of cladoceran (Moina micrura and Bosminopsis deitersi) density was also obeserved. At this time, small rotifers including Polyarthra spp. reached maximum density. Gut analysis of fish demonstrated that small-sized juvenile fish (< 15 mm in total length)preferred large rotifers as well as cladocerans, while large sized fish (> 15 mm)selected only cladocerans. On the other hand, juvenile Micropterus salmoides of which size was larger than other juvenile fish consumed not only zooplankton but also other small juvenile fish. Based on these results, the decline of large rotifers and cladocerans during early summer in the river seems to be result of predation by juvenile fish. However, the period when juvenile fish maintained their high density was as short as one month and the decreased density of cladocera rapidly recovered as soon as juvenile fish became scarce. Such a short period of juvenile fish devel-opment in the river can be attributed to the consumption of juvenile fish by the young-of-the-year cohorts as well as adults of M. salmoides. The high trophic state of the river might permit the rapid recovery of the cladoceran community. The predation impact of juvenile fish in the Nakdong River seems to be affected by the existence of piscivore as well as high trophic status.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.2
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• pp.109-117
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• 1997

In order to hold the behavior of fish school to the set-net, a series of tag-recapture experiments were carried out in two fishing grounds of the middle sized set-nets which were located in 20m depth on the coast of Keojedo and Namhaedo in the Southern part of Korea from September to October in 1996. In the experiments, the leading ability of the leader and the fish court and the recapturing ability of the bag nets were checked out for the six species of fish in method of discharging the tagged fishes at side points of leader, and the middle points of the fish court and the bag nets in a hauling step, and recapturing them at the bag nets in the next hauling. The results obtained are as follows; 1. The ratio recaptured at the both side bag-nets in the next hauling after discharged from the fish court in the previous step was 20.3% in small size of mackerel Scomber japonicus, 16.2% in small size of horse mackerel Trachurus japonicus, 10.3% in black sea-bream Acanthopagrus schlegelii, 19.1% in red barracuda Syhyraena pinguis, 16.3% in halfbeak Hemiramphus sajori, 20.0% in gizzard shad Konosirus punctatus individually, and totally in six species of fish, that was 17.2%. 2. The ratio recaptured at the same bag net after discharged in the both side bag-nets was 21.7% in small size of mackerel, 21.5% in small size of horse mackerel, 6.7% in black sea-bream, 17.8% in red barracuda, 16.8 in half-beak, 19.1% in gizzard shad individually, and totally in six species of fish, that was 18.8%. 3. The leading ratio from side points of the leader departed from door in 25m to fish court was 58.9% in small size of mackerel, 74.6% in small size of horse mackerel, 38.0% in black sea-bream, 54.7% in red barracuda, 58.6% in half-beak, 54.5% in gizzard shad individually, and totally in six species of fish, that was 57.8%. So it was assumed that the leader of set-net was very effective in leading to the swimming direction of small size of mackerel, small size of horse mackerel, red barracuda, half-beak and gizzard shad. 4. Red barracuda, half-beak and gizzard shad entered into bag net of upstream in large numbers than bag net of downstream, and small size of horse mackerel and black sea-bream entered into bag net of downstream in large numbers than bag net of upstream. 5. Small size of mackerel and small size of horse mackerel had high remaining rate in the bag net of downstream, and black sea-bream, red barracuda and half-beak had high remaining rate in the bag net of upstream.

• Journal of Aquaculture
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• v.22 no.1
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• pp.63-67
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• 2009

In order to establish optimum anesthesia concentration, we tested the efficacy of clove oil at five different concentrations in large sized (mean SL $17.1{\pm}2.21\;cm$) and small sized (mean SL $0.6{\pm}0.06\;cm$) dark-banded rockfish Sebastes inermis. Optimal anesthesia concentration for dark-banded rockfish was $150\;mgL^{-1}$ in both large and small sized fish. In general, fish exposed to higher anesthetic doses were rapidly induced but took longer to recover (P<0.05). Recovery time of small sized fish was longer than large sized fish in lower concentrations, while recovery time of large sized fish was longer than small sized fish in higher concentration (P<0.05). Using the established optimum aesthetic concentration, we evaluated the physiological response of dark-banded rockfish to clove oil by measuring plasma cortisol and glucose levels. Following administration of $150\;mgL^{-1}$ clove oil at $20^{\circ}C$ (optimum breeding temperature), plasma cortisol level was highest ($42.2{\pm}11.318{\mu}g/dL$) after 0 hour, while plasma glucose level was highest ($52.5{\pm}10.61\;mg/dL$) after 1 hour. Plasma cortisol and glucose concentrations required 6 and 2 hours, respectively, to return to pre-exposure levels.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.3
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• pp.259-269
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• 2014

The objectives of this study to determine seasonal changes in species composition and abundance of fish and decapod assemblage, and the relationships between environmental factors and their abundance in an eelgrass bed of Jindong Bay. A total of 26 fish species and 29 decapod species were collected by a small beam trawl from an eelgrass bed in Jindong Bay in 2002. The dominant fish species were Hexagrammos otakii, Pholis neulosa and P. fangi and these accounted for 48.4 % in the total number of individuals. Dominant decapod taxa were Palaemon macrodactylus, Charybdis japonica, Pagurus minutus and C. bimaculata. These were primarily small species or early juveniles of larger species. Species composition and abundance varied greatly showing a peak in the number of individuals in April and May, and peak biomass in fish in July and decapods in August. Catch rate was low in winter months both in fish and in decapod. Seasonal changes in the abundance of fishes and decapods corresponded with eelgrass biomass and abundance of food organisms indirectly.

• Fisheries and Aquatic Sciences
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• v.8 no.3
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• pp.142-150
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• 2005

The effects of photoperiod, temperature, and fish size on oxygen consumption (OC) in the black porgy Acanthopagrus schlegeli, a euryhaline marine teleost, were studied using a closed recirculating seawater system with a respiratory chamber. Fish reared in indoor recirculating seawater tanks were divided into two groups: small (15.7-55.8 g, mean 38.1$\pm$15.9 g) and large (108.7-238.8 g, mean 181.8$\pm$54.9 g) fish. The OC of the fish showed a clear diel rhythm, with higher values in the daytime and lower values at night, in accordance with light (09:00-20:59 h) and dark (21:00-08:59 h) cycles. The OC of the fish increased linearly with the water temperature. The OC was the highest at 10:00 h, one hour after the onset of daylight and was the lowest at 03:00 h, six hours after dusk. The average OC at $20^{\circ}C$ during the light period was as high as 219.8 mg $O_2$/kg/h in the small fish and 156.3 mg $O_2$/kg/h in the large fish, while during the dark period it was as low as 130.5 and 110.4 mg $O_2$/kg/h, respectively. The OC during the dark period, which showed limited variation, could be regarded as the resting OC, and was 107.6, 130.5, and 219.8 mg $O_2$/kg/h at 15, 20, and $25^{\circ}C$, respectively, in small fish, and 52.3, 110.4, and 171.0 mg $O_2$/kg/h in large fish. As the body weight of black porgy increased, the OC decreased exponentially and the relationship was expressed as OC=1,222.8$BW^{-0.567}$, OC=1,113.2$BW^{-0.448}$, and OC=1,495.3$BW^{-0.468}$ at 15, 20, and $25^{\circ}C$, respectively. At a fish density of 14.5 g/L at $20^{\circ}C$, black porgy had the highest OC per breath compared to fish at the same density at 15 or $25^{\circ}C$. This suggests that the black porgy responds to the stocking density (15 kg/$m^3$) and water temperature ($20^{\circ}C$) conditions commonly observed in intensive aquaculture with the deepest breath and the highest metabolic activity.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.3
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• pp.1-7
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• 2010

The ichthyofauna and passing efficiency of fishways were surveyed in Geumgang estuary from May to October in 2009. The fishes collected were classified into 24 species, 23 genera belonging to 8 families. These 24 species consist of 17 freshwater fish species, 3 migration fish species and 4 peripheral freshwater fish species. Seasonal function of fishways showed the migration from May to June and returning to the reservoir of fishes be washed out to sea when sluice gate open by rainfall in July and August. Most of the fishes catched in fishways moved from middle tide to high tide except for July. Fishes ascended fishways between the middle ebb tide and the ebb tide only July, because small freshwater swim against the fishway for leaching the reservoir through the newly formed flow when the water level at the fishway kept dropping. Small fishes that body length less than 200 mm mainly used gabion type fishways and fishes over 200 mm utilized a cascade type fishways. Based on the total individuals collected, the efficiency of the fishway was 1 % for the anadromous fish and over 80 % for freshwater fish. Therefore, it is concluded that ecological function of the fishway in the Geumgang estuary dike be very important not only for fish migration but also freshwater fishes's returning.

• The Journal of Fisheries Business Administration
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• v.35 no.2
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• pp.71-90
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• 2004

According to this study, overall economic impacts of the FTA between Korea and Singapore upon fish and fishery products of our country were likely to be very small and insignificant. When the tariff on fish and fishery products between the two borders were completely eliminated, if no roundabout exports from other ASEAN countries were practicing, then this study calculated that the increase of imports from Singapore in the 12 chief items was estimated to be only about 250,000kg, which comes to the amount of 1.1 billion won. The 12 items used here account for over 90% imports of fish and fishery products from Singapore. This study also revealed that imports of fish and fishery products from Singapore would be substituted for domestic products more than 100,000kg in the 7 items produced domestically. The substitution effect represents fishermen's demage by replacing domestic products by imports in terms of income which comes to the amount of 438 million won. As the results of the study shows, establishing an FTA between the two countries will not exert so much adverse effects on our fisheries because relative importance of fish and fishery products in both countries are very small. But the contents of the agreement on fish and fishery products between the two countries are very important, as concluding the negotiation and signing the agreement between Korea and Singapore would be a precedent in future negotiations with other asian countries, especially with China and ASEAN countries.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.730-744
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• 2016

In this study, fish fauna and stream characteristics were surveyed from June to October of 2014 in 31 sites of 23 small streams of Namhae Island. During the study period, 38 species belonging to 30 genera under 13 families were collected. Cyprinidae and Gobiidae fish occupied 28.9% (11 species) and Cobitidae fish accounted for 10.5% (4 species). The dominant family was Cyprinidae, and the most dominant species was Zacco koreanus with 30.3% (1,089 individuals) of the total. Eight species (33.8%) such as Zacco koreanus, Squalidus gracilis majimae, Coreoleuciscus splendidus, Pseudobagrus koreanus, Iksookimia hugowolfeld, Iksookimia longicorpa, Silurus microdorsalis and Liobagrus mediadiposalis were Korean endemic and one species of Micropterus salmoides was exotic. According to the analysis of the community based on the diversity, evenness and richness indices, fish community seems to be more stable in the S7. The small streams were classified into three types of steep mountainous, mountainous-flatland, and flat land streams, and their types were categorized by their features of stream width, water depth, bottom substrate, riparian vegetation, and land use patterns. Principal component analysis based on species abundance classified fish communities into three main groups according to human impact and land-use pattern change. These results suggest that fish community structures were primary affected by the longitudinal environmental changes and these were modified by the habitat condition in accordance with the land use pattern change in the small streams.