• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.411-422
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• 1986

Diets of the rock trout, Agrammus agrammus, in the shore area of Tongbaeksom, Pusan over the period of July 1981 to June 1982 were studied. Specimens were sampled by angling. Stomach analysis showed that the rock trout fed mainly on epibenthic food in the littoral zone along the coast of Tongbaeksom. The food organisms of the enviornment were studied by means of underwater sampling around the angling area for this study. Although the food items of the fish changed slightly with season and age-group, main food items were Amphipoda (Gammaridae, Caprellidae) and Isopoda (Sphaeromidae, Idotheidae). This suggests that the diets of A. agrammus mainly comprised epibenthic food. Food diversity increased with age. The fish almost consummed on smaller food in size, but had selective predation according to food size, i. e. on larger food as age increases. These data provide additional support for the importance of the detritus-benthos-consummer type food chain.

• Journal of Fisheries and Marine Sciences Education
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• v.11 no.1
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• pp.88-97
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• 1999

Auditory thresholds were determined by means of a conditioned response to sound stimuli at frequencies 80, 100, 200, 300, 500 and 800 Hz for a 10 black rock fish, Sebastes schlegeli. The conditioned response was a change of a cardiac rhythm. It was established through an electric shock as unconditioned stimulus, and could be monitored on an oscilloscope. A stable acoustic condition was obtained by suspending the fish in a small cage at fixed position in the test tank. The sensitive frequencies ranged from 80 Hz to about 800 Hz, showing the best frequency around 100 Hz where the mean threshold value was 90.5 dB. A gradual rise below 300 Hz and a relatively sharp turn above 500 Hz were indicated in the audiogram. The method presented here seemed to be useful for a rapid determination of the audiogram of fishes.

• Journal of fish pathology
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• v.36 no.2
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• pp.229-238
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• 2023

In this study, the correlation between clinical changes and RSIV genome copy number was investigated to determine the quantitative criteria for the characteristics of RSIV infection. The rock bream (Oplegnathus fasciatus) was intraperitoneally injected with three different doses (1.0×10¹, 1.0×10³ and 1.0×10⁵ viral genome copies/fish) as low, medium, and high doses, respectively. The clinical signs (spleen enlargement, death) observation and real-time PCR were conducted at 5, 10 and 14 days post-injection. During the experiment, spleen index as a quantitative indicator for spleen enlargement was continuously increased in the medium- (up to 2.26) and high-dose (up to 4.99) challenge groups, respectively. Notably, when the spleen index was over 1.5, 2.0, 2.5 and 3.0, a positive correlation was revealed with average viral genome copy numbers of 2.51, 3.37, 4.97 and 5.43×10⁷ viral genome copies/mg, respectively. Moreover, the threshold of spleen index over 1.5 was 1.0×10⁶ viral genome copies/mg, while the thresholds of spleen index over 2.0 and dead was 2.51×10⁷ viral genome copies/mg and the thresholds of spleen index over 2.5 and 3 was 3.98×10⁷ viral genome copies/mg. These findings suggest the possibility of quantitatively analyzing the characteristics and development process of RSIV infection.

• Journal of fish pathology
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• v.23 no.1
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• pp.17-25
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• 2010

We have identified an iridovirus CH-1 from sea perch Lateolabrax sp. healthy externally and imported from China to Korea. In a comparison of the nucleotide sequences of the five different genomic regions, the CH-1 appears to be closely related to the ISKNV, IVS-1 and Ehime-1 strains detected in China, Korea and Japan respectively. In quantitative comparison of the viral DNA, level of CH-1 in tissue of imported fish was 10,000 times lower than that of IVS-1 strain presented in the infected rock bream Oplegnathus fasciatus of moribund stage. It allowed us to speculate the possibility of the asymtomatic iridovirus infection in the culturing sea perch. Such possibility of asymptomatic infection was supported by result of no appearance of dead fish with typical symptoms of iridoviral disease in keeping experiment of the imported sea pearch in laboratory for more than three weeks. Such asymptomatic infections with iridovirus were also found in spleen of the culturing and externally healthy sea perch of Korea by the presence of the iridoviral DNA in nested PCR.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.6
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• pp.435-439
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• 2008

The antimicrobial resistance of 160 strains of Enterococcus faecalis and 173 strains of E. faecium to 12 antimicrobial agents was investigated. The test strains were isolated from 126 wild seawater and farmed fish, including olive flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagrus major), and sea bass (Lateolabrax japonicus), in 2005 and 2006. Overall, 91.9% of the E. faecalis isolates and 88.4% of the E. faecium isolates showed antimicrobial resistance to at least one antimicrobial agent. The pattern of antimicrobial resistance of the isolates differed little according to the species of fish. The percentage of E. faecalis and E. faecium with specific antimicrobial resistance differed according to the sample source. For the isolates from farmed fish samples, 66.7% of E. faecalis were tetracycline resistant and 54.5% of E. faecium were erythromycin resistant. By contrast, in the wild fish seawater samples, 92.0% of E. faecalis were rifampin resistant and 88.5% of E. faecium were tetracycline resistant.

• Korean Journal of Veterinary Research
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• v.42 no.4
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• pp.451-457
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• 2002

The purpose of the present experiment was to investigate the micronuclei (MN) frequency in cytokinesis-blocked (CB) cells after various doses of gamma-rays in two species (fish and fowl) and so to contribute to the clarification of the question whether these species are suitable as a target organism in the test system. The frequencies of binucleated cells, and gamma-ray-induced MN in CB cells at several doses were measured in three donors of two species. No binucleated cell was noted in erythrocyte. The peaks of binucleated lymphocyte formation were found at a concentration of 2% phytohaemagglutinin (PHA) and $3{\mu}g/m{\ell}$ cytochalasin B (Cyt-B) in fish at 144 hours after incubation and 2% PHA and $6{\mu}g/m{\ell}$ Cyt-B in fowl at 72 hours after incubation. But the micronucleus counts failed to show any evidence of radiation damage. Measurements performed after irradiation showed a dose-related decrease in the formation of binucleated cells in each of the donors studied. Results indicated that the assays were not suitable for this due to blastization inhibition (binucleation failure) after irradiation. We concluded that the use of CB cell from fish and fowl for detecting the results of mdiation exposure was highly questionable.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.288-301
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• 2000

The species composition and seasonal variation of fish assemblage in the coastal water off Gadeok-do, Korea were studied using the monthly trawled samlpes through a year of 1998. During the study period, 110 species of fishes from 57 families were collected. Repomucenus valenciennei, Thryssa kammalensis, Leiognathus nuchalis and Zoarces gilli dominated the fish assemblage throughout the year, and were responsible for $ 57.6{\%}$ and $37.2{\%}$ in the number of individuals and biomass, respectively. Fish species of secondary importance in abundance were Sillago japonica, Apogon lineatus, Pholis fangi, Engraulis japonicus, Thryssa adelae, Pho;is nebulosa, Conger myriaster, Liparis tanakai, Acentrogobius pflaumii, Limanda yokohamae, Chaeturichthys hexanema, Erisphex pottii and Cunoglossus abbreviatus. Higher numbers of species were collected in spring and autumn than in summer and winter. Abundance was high in spring and autumn, and low in summer and winter, Species diversity indices showed that the fish assemblage was more diverse in autumn than any other seasons.

• Journal of Fisheries and Marine Sciences Education
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• v.18 no.2
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• pp.164-171
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• 2006

kochukaru (chili powder) and various vegetables. As its main ingredient, fresh or sea-water fish is cut into several pieces and boiled with ground beef and green vegetables such as watercress as well as garland chrysanthemum. In addition, onion, radish, chilies, crown daisy, garlic and some times, pumpkin and bean curds are added to the mixture to absorb the kochujang which is the base flavor of this dish. It is then seasoned with kochukaru, garlic, soy sauce and if needed, more kochujang to suit everyone's taste buds. Restaurants that offer this dish often allow you to select your fish from a tank. Many specialty seafood restaurants have several tanks from which you may choose a fish. Popular fish for this dish may include Korean rockfish, flounder, yellow corvina, codfish, croakers, pollacks, and even fresh water fish like carp and trout. In addition, other shell fish such as crabs, clams and oysters can be also added to this soup to compliment and enhance its spicy but refreshing flavor. This soup is one of Korean's most popular dishes while drinking soju. If you order sushi or sashimi, the soup is made from the left-over parts of the fish. The objective of this study is to determine a standardized recipe of Maeun-Tang and to investigate consumption so as to increase its intake opportunities for consumers through its development. Fish species used in Maeuen-Tang's recipes were flounder, Korean rockfish and other fish. Onion, radish, chilies, crown daisy, garlic and some times, pumpkin and bean curds were added to the mixture to absorb the kochujang which is the base flavor of this dish. Most of the stock used in Maeuen-Tang's recipes is pure water, fish stock and vegetable stock, 1.0-1.5 Korean rock fishes and 0.5-1.0 flounders, with its head and bone, which were used in 3-4 portions of Maeun-Tang. Most of the seafood restaurants used seasoning which didn't age and was made by the restaurant. The cooking equipment used in the Maeuen-Tang's recipes were a cook-port and earthen bowl.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.39-39
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• 2003

Antioxidant enzyme genes play a key role in cell defense against the lethal effects of oxidative stresses in animals and have an essential function which has allowed the evolution of aerobic respiration starting from an ancient form of oxygen-insensitive life. Piscine antioxidant enzymes are also involved in the rapid response to various toxic chemicals as well as many biological stresses, indicating that they could be used as biomarkers for health and aquatic environment. With the purpose for developing fine molecular probing tool to assess the stresses in marine fish, we identified three major antioxidant enzyme genes (superoxide dismutase, catalase and glutathione-S-transferase) from Korean rock bream using expressed sequence tag analysis and/or high density filter screening. Here we report the molecular information on these gene transcripts including complete sequence data and expression profiles.

• Computers and Concrete
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• v.19 no.1
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• pp.99-110
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• 2017

In this paper, the effect of normal load on the failure mechanism of echelon joint has been studied using PFC2D. In the first step, calibration of PFC was undertaken with respect to the data obtained from experimental laboratory tests. Then, six different models consisting various echelon joint were prepared and tested under two low and high normal loads. Furthermore, validation of the simulated models were cross checked with the results of direct shear tests performed on non-persistent jointed physical models. The simulations demonstrated that failure patterns were mostly influenced by normal loading, while the shear strength was linked to failure mechanism. When ligament angle is less than $90^{\circ}$, the stable crack growth length is increased by increasing the normal loading. In this condition, fish eyes failure pattern occur in rock bridge. With higher ligament angles, the rock bridge was broken under high normal loading. Applying higher normal loading increases the number of fracture sets while dilation angle and mean orientations of fracture sets with respect to ligament direction will be decreased.