• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.2
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• pp.128-133
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• 2003

Stimulus effects of strobe light on jack mackerel Trachurus japonicus were studied by measuring the heart rate change according to the different strobe light intensity of 5~75 lx$\cdot$s. Heart rate was observed for 60 min: 10 min before, 30 min during and 20 min after the strobe light stimulus. The measurement of heart rate was repeated three times at 2 hour intervals. The results showed that the heart rate increased during stimulus but temporarily decreased immediately after ending of stimulus. The heart rate changes in both during and after stimulus were decreased with reducing light intensities. The heart rate change according to the repeated experiment was not remarkably different under the lower light intensity

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.3
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• pp.156-162
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• 2006

The halophilic enterobacteria, Enterobacteria cancerogenus, was isolated from the intestines of the fusiform fish (Trachurus japonicus) to yield a protein-like material termed PLM-f74. PLM-f74 was characterized by strong inhibition ratios to angiogenesis (82.8% at the concentration of $18.5{\mu}g/mL$) and elevated antioxidative capacities with low toxicity. The PLM-f74 is a glycoprotein comprised of saccharides and amino acids. PLM-f74 inhibited non-activated U937 monocytic cell adhesion to HUVECs activated with IL-$1{\beta}$ by 78.0%, and the adherence of U937 cells treated with the PLM-f74 and stimulated with IL-$1{\beta}$ to unstimulated HUVECs decreased by 102%. When both cell types were pretreated with PLM-f74, the adhesion of U937 cells to IL-$1{\beta}$ stimulated HUVECs was completely suppressed by 121% at a concentration of 18.5 ug/mL. PLM-f74 blocked signal pathways from VEGFR2, PI3K, ${\beta}$-catenin and VE-cadherin to NF-kB based on western bolt analysis. And also inhibited IL-1-stimulated HUVEC expression of the adhesion molecules, ICAM-1 by 40%, VCAM-1 by 60%, and E-selectin by 70% at the same concentration noted above. New anti-angiogenic and anti-cell adhesion materials showing elevated antioxidative capacities and non-toxicity may be expected from these results.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.3
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• pp.189-195
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• 2023

This study quantitatively evaluated size selectivity for three netting shapes (T0; regular, T45, T90) and hanging ratio (35%, 70%) of T0 netting used for trawl codend. The size selectivity experiment was performed in a tank using a cube experimental model with a length of 50 cm on one side and 389 experimental individuals, jack mackerel (Trachurus japonicus). In the selectivity analysis, a selectivity curve was created based on the selection ratio using a logistic function, and the 25%, 50%, and 70% selection length and selection range (SR) were obtained. The T0 netting was 19.54 cm when the 50% selective length, which is a selectivity evaluation index, had a hanging ratio of 35%, a selection range of 0.51 cm, and 22.70 cm and 3.08 cm for the hanging ratio of 70%. The T45 netting was 24.34 cm and 2.13 cm, and the T90 netting was 23.51 cm and 2.84 cm. The results of the T45 netting and the T90 netting are similar, and the 50% selection length and selection range were relatively larger than the T0 netting. There was a significant difference in the correlation between the circumference of the inner circle of the mesh by the shape of the netting and the body girth of the experimental individual (Pearson test, r = 0.86, p < 0.05). There was no significant difference in the correlation between the selection ratio by the T0 netting, T45 netting, and T90 netting with a 70% hanging ratio (one-way ANOVA, p > 0.05). The results of this study showed that selectivity such as T45 netting and T90 netting appeared when the hanging ratio, which maximizes the area of T0 netting, was maintained at 70%.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.223-231
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• 2001

For the purpose of providing the basic data on the improved fishing gear and the man power saving, which contribute to enhance fishing efficiency of set net in the coast of Jeju Island, this study executed the test of fish tank by reducing these actual nets by 1/30 and using the manufactured model nets, and observed and interpreted the behaviors of entering and escaping of the schools of mackerel Scomber japonicus, horse mackerel Trachurus japonicus and rabbit fish Siganus fuscescens. Thereby the result is as follows ; 1. After the elapsed time of 60 seconds, in case of rectangular set net, the ratio for entering by a school of fish marked 50% with mackerel, 18% with horse mackerel and 28% with rabbit fish, and in case of pound net, the ratio for entering net by a school of fish marked 70% with mackerel, 60% with horse mackerel and 30% with rabbit fish. 2. After the elapsed time of 60 seconds, in case of rectangular set net, the ratio for escaping by a school of fish marked 70% with mackerel, 40% with horse mackerel and 24% with rabbit fish, and in case of pound net, the ratio for escaping from net by a school of fish marked 0% with mackerel, 0% with horse mackerel and 3% with rabbit fish. 3. After the elapsed time of 60 seconds, in case of rectangular set net, the ratio for remaining by a school of fish marked 30% with mackerel, 60% with horse mackerel and 76% with rabbit fish, and in case of pound net, the ratio for remaining by a school of fish marked 100% with mackerel, 100% with horse mackerel and 97% with rabbit fish.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.3
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• pp.161-171
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• 1994

Mesh selection analysis for the trawl net were carried out at the Southern Korean Sea and the East China Sea during the 1992-1994 years by the training ship Seabada of the National Fisheries University of Pusan, using A type (51.2mm), B type (70.2mm), C type (77.6mm), D type (88.0mm) square mesh cod-ends. The fishing trials were made using bottom trawl of the trouser type cod-end with cover net. Selection curves and selection parameters were calculated by a logistic model for Sphyraena pinguis, Pampus argenteus, Trachurus japonicus, Pagrus major, Callanthias japonicus, Trichiurus lepturus. The results obtained are summarized as follows: 1. Red barracuda : Selection range and fifty percent selection length in the A type was 115.8mm, 292.8mm, respectively. 2. Harvest fish : Each selection range and fifty percent selection length in the B. C. and D type was 37.7mm, 113.8mm : 40.1mm, 131.7mm and 64.8mm, 148.6mm, respectively. Selection parameters of master curve were : slope, 3.81 : intercept, -6.4. Optimum mesh size was 89.3mm. 3. Horse mackerel : Each selection range and fifty percent selection length in the A, B, C and D type was 43.0mm, 148.3mm : 60.7mm, 183.2mm, 214.5mm and 91.4mm, 254.9mm, respectively. Selection parameters of master curve were : slope 2.30 : intercept, -6.4. Optimum mesh size was 66.8mm. 4. Red seabrem : Selection range and fifty percent selection length in the D type was 42.7mm, 203.4mm, respectively. 5. Yellowsail red bass : Selection range and fifty percent selection length in the A type was 84.0mm, 110.6mm, respectively. 6. Hair tail : Each selection range and fifty percent selection length in the A, B and C type was 59.7mm, 176.0mm : 100.9mm, 250.7mm and 178.6mm, 307.0mm, respectively. Selection parameters of master curve were : slope, 1.54 : intercept, -5.4. Optimum mesh size was 57.5mm.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.4
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• pp.311-320
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• 1997

We selected horse mackerel Trachurus japonicus, mackerel Scomber japonicus and arrow squid Todarodes pacificus, to be used in the experiment. These fishes migrate to the Cheju coast and were caught by set-net. We studied on the attracting effect and the leading effect on the fish school using incandescent lights in an outdoor water tank at the Marine Research Institute Cheju National University. The results obtained are summarized as follows; 1. The horse mackerels, mackerels and arrow squids were actively attracted to the incandescent light. The optimum illumination and the reactions of each fish school were different though. 2. We turned the first attracting lamp on and turned it off after ten minutes. Then we turned the second attracting lamp on and turned it off after another ten minutes. The reaction of each fish school was a little bit different, but it worked to lead them to their destination. 3. We turned the three attracting lamps on at the same tune. After ten minutes, We turned the first attracting lamp off. After another ten minutes we turned the second attracting lamp off. The reaction of each fish school was a bit different, but it worked to lead them to their destination. 4. One incandescent light was moving. The reaction of each fish school was a little bit different, but it worked to lead them to their destination.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.95-106
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• 2021

In order to understand the seasonal variations of species composition of fish in the Goseong, middle East Sea of Korea, we surveyed fish fauna using set net during 2 years. In this study, a total of 77 taxa belonging to 40 families were collected and 75 species were identified. The dominant family were Tetraodontidae and Pleuronectidae, and the dominant species were Arctoscopus japonicus, Konosirus punctatus, Stephanolepis cirrhifer, Thamnaconus modestus, and Trachurus japonicus. The results of the hierarchical clustering using the number of individuals of collected species showed that they are divided into three seasonal groups: Group A (Jan.~Apr.), Group B (May~Jun., Nov.~Dec.), Group C (Jul.~Oct.). The sea surface temperature (SST) was higher than the results of previous studies in winter and spring, and species composition in spring have changed from cold-water species to the warm-water species, recently. The species composition has become similar to the that of southern Gangwon-do regions (Samcheok and Gangneung) of the previous studies. The species diversity of family Tetraodontidae has increased, which is estimated to have an effect on increase in SST and the quantity of entering the East Sea. Therefore, we assumed that the change of species composition is related to the extension of northern distribution limits and survival temperature, and abundant preys. Therefore, it is necessary that an efficient resource management policy as well as the ways of commercially use of migratory warm-water fish, rapidly.

• Korean Journal of Ichthyology
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• v.22 no.3
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• pp.168-178
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• 2010

Fish assemblages associated with rock reef and non-rock reef were studied using specimens collected at three sites in Geomun Island waters of the Southern Sea, Korea, in February, May, August and October, 2006. Two survey methods for the study were followed: collection by a gill net, and video observation by scuba diving. The gill-net survey was conducted during the night, the scuba-diving observations were conducted during the day. From the gill-net survey, a total of 40 species, 380 inds. and 71,426.9 g was caught at the three sites. The dominant species was Trachurus japonicus; other species were Raja kenojei, Dasyatis akajei, Stephanolepis cirrhifer, Narke japonica, Pagrus major, Sebastes inermis, and Sphyraena pinguis. At the rock-reef site, a total of 26 species, 264 inds. and 46,776.7 g was caught by gill net, and the dominant species was T. japonicus. A total of 17 species, 45 inds., 10,535.1 g was caught at the flat-bottom 1 site, and 19 species, 71 inds. and 14,115.1 g were caught at the flat-bottom 2 site. The scuba-diving survey resulted in 13 species and 1,749 inds. observed at the three sites through the survey period. The main observed fishes were rock-dwelling species such as Chromis notatus, Microcanthus strigatus, S. cirrhifer, Ditrema temmincki, Evistias acutriostris, Girella punctata, Halichoeres poecilopterus, Hexagrammos agrammus, Prionurus scalprum, Sebastes inermis, and Semicossyphus reticulatus. Seven species and 1,739 inds. observed at the rock-reef site comprised 99.4% of the inds. of the three sites. Therefore, the fish community in Geomun Island waters included many rock-reef. species, but a few were migratory species like T. japonicus and Scomber japonicus. The abundance of fish at the rock-reef site was high in comparison with those at two non-rock reefs. The dominant species were very different between the day and the night, although rock-reef species comprised the main part of the fish community. We conclude that the high abundance of fish in Geomun Island waters is most closely related to physical structure, such as rock reefs, which is the main habitat of many fishes.

• Korean Journal of Ichthyology
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• v.13 no.3
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• pp.210-219
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• 2001

The fisheries resources of the set net fishery on four fishing grounds (Pyuong Dae, Gu Eum, Du Moah, Gang Jeong) in coastal waters of Jeju Island were studied to the determine catch-variation characteristics from January, 1998 to December, 1999. A total catch of 153,862 kg was made through the survey period. The large total was related mainly to the high catch of Trachurus japonicus, which comprised 58.2% of the total. Other dominant species which account for 23.0% of the total catch were Siganus fuscescens, Todarodes pacificus, Loligo chinesis, Seriola lalandi, Sepioteuthis lessoniana, and Seriola quinqueradiata. Catch density was high in Gu Eum (more than 100,000 kg), whereas those in Pyuong Dae, Du Moah, and Gang Jeong were less than 30,000 kg in total. The fishing period of the set net fishery was from April to December, which was also closely related to the variation of the sea water temperature in the fishing grounds. The ranges of water temperature in the four fishing grounds were $18{\sim}26^{\circ}C$ in Pyuong Dae, $16{\sim}26^{\circ}C$ in Du Moah, $15{\sim}26^{\circ}C$ in Gu Eum, and $15{\sim}26^{\circ}C$ in Gang Jeong.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.3
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• pp.241-248
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• 2002

The combined hydroacoustic and demersal trawl surveys to investigate the distribution characteristics of fish schools in the Yellow Sea and the East China Sea were carried out during the spring of 1997 by the training ship "Nagasaki Maru" of Nagasaki University. Fish samples were collected by bottom trawling from 9 trawl stations randomly selected in the survey area, and the species and length compositions of trawl catches are examined. Hydroacoustic data were collected by using a Furuno FQ-50 scientific echo sounder operating at 50KHz and the data stored in field were later processed in the laboratory. The results obtained can be summarized as follows ：1. In the 9 trawl surveys conducted in the Yellow Sea and the East China Sea, 78 species including 80 species of fishes, 4 species of Cephalopoda and 6 species of Crustacea, were identified. The most abundant species in these stations were swimming crab(Portunus trituberculatus), Japanese horse mackere(Trachurus japonicus), redlip croaker(Larimichthys polyactis) and the catch per one hour in each station ranged 7.7 to 182.5 kg/hour. 2. The mean volume backscattering strength for the entire water column and the bottom layer of the 0-10 m from bottom friction were -74.6 ㏈ and -68.2 ㏈, respectively. That is, the mean volume backscattering strength for the bottom layer was 6.4 ㏈ higher than that for the entire water column 3. In the surveys during the spring of 1997, the geographical distribution characteristics of fish schools suggests a trend of decreasing fish abundance toward the coast area of Korea and the highest demersal concentrations appeared in waters between the Cheju Island and the Tsushima Island 4. The distribution density of fish school in the East China Sea and Yellow Sea during the 1997 acoustic survey were estimated to be 6.65$\times$10$^{-5}$ kg/㎥ in the entire water column and 2.86$\times$l0$^{-4}$ kg/㎥ in the bottom layer, respectively.pectively.