• Korean Journal of Ecology and Environment
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• v.52 no.2
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• pp.118-125
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• 2019

Swimming performance of fish is an important factor in the survival of fish. Also, swimming performance of fish is used in the form of habitat, or as a condition to consider when creating a fish ladder. However in Korea, researches in swimming performance of Korean freshwater fish were scarce and inadequate in some part, thus fish ladders were installed without considering their swimming performance. Therefore, in this study, we measured swimming performance of 4 Korean freshwater fish species to consider importance of swimming performance test. The fish used in this study were Carassius auratus, Zacco koreanus, Gnathopogon strigatus, Acheilognathus lanceolata intermedia species which was collected during October to November, 2018 at Geum River, and measurement for swimming speed of each fish was done by using $Loligo^{(R)}$ System, swim tunnel respirometer in January to February of 2019. The average value of the burst critical swimming speed ($U_{crit}$) for each species was $0.8{\pm}0.04m\;s^{-1}$ for C. auratus, $0.77{\pm}0.04m\;s^{-1}$ for Z. koreanus, $0.95{\pm}0.04m\;s^{-1}$ for G. strigatus, $0.73{\pm}0.03m\;s^{-1}$ for A. lanceolata intermedia and the average value of prolonged critical swimming speed was $0.54m\;s^{-1}$ for C. auratus, $0.67m\;s^{-1}$ for Z. koreanus, $0.7m\;s^{-1}$ for G. strigatus, $0.54m\;s^{-1}$ for A. lanceolata intermedia. Since the fish used in this experiment were collected from a small part of the water system in Korea and there were only 4 species, they were not enough to represent the species that inhabit the entire Korean water system. It will be necessary to continue evaluating the swimming performance of other freshwater species in Korea.

• Journal of Aquaculture
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• v.21 no.4
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• pp.325-330
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• 2008

Two different Eelwardsiella tarda isolates, KFE and Edk-2, were obtained from Korea and Japan respectively. On the base of the previous results showing higher pathogenicity of E. tarda KFE compared to that of E. tarda Edk-2 isolate, we tried to determine the differences of antigenicities of these two isolates in loach which is one of the important species in freshwater aquaculture in Korea. Concentration of specific antibody in the serum appeared to be much higher in loach immunized with FKC of E. tarda Edk-2 than those found in loach immunized with FKC of E. tarda KFE. Cross-reaction analysis using agglutination test with normal and antigen-absorbed antisera implied the differences epitopes in the antigens of these E. tarda isolates. For the comparison of bactericidal activity of the produced antibody with different antigens, absorption analysis was performed and confirmed the presence of critical epitopes in the FKC of E. tarda KFE strain. The prophylactic agent, polysaccharide-bound protein (PS-K) injected 1 week before the artificial infection with E. tarda KFE isolates decreased the cumulative mortality in loach and would be on effective method to prevent the occurrence of bacterial infection including E. tarda.

• Korean Journal of Ichthyology
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• v.24 no.3
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• pp.160-166
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• 2012

Egg development and early life history of the endangered Korean freshwater fish, Microphysogobio koreensis, was investigated to get a basic information for establishing its conservation strategy. The matured adult fishes were sampled at Imsil-gun, Jeollabuk-do, Korea in May 1 2012 and artificially fertilized. The fertilized eggs were spherical, separated demersal and $1.8{\pm}0.14mm$ in diameter. The hatching of the embryo began at about 29 hours after fertilization under water temperature of $23^{\circ}C$. The newly hatched pre-larvae were average $2.2{\pm}0.48mm$ in total length. At 4 days after hatching, the post-larvae were $3.6{\pm}0.55mm$ in total length and york sac was completely absorbed. At 20 days after hatching, their fin rays were formed and finally the larvae entered juvenile stage and grew up to $6.5{\pm}0.77mm$ in total length. At 60 days after hatching, the total length reached $24.4{\pm}1.71mm$, and the band patterns of he head and lateral side were similar to adult fish. Based on this study, the fertilized eggs of M. koreensis hatched more quickly and the pre-larvae length was also smaller, compared with related species.

• Korean Journal of Ecology and Environment
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• v.52 no.4
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• pp.306-315
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• 2019

The estuary of the Han River constantly suffers from pollutants and pathogenic microorganisms which could cause serious damage to aquatic organisms living there. Despite of this potential risk, it is hard to find any reliable scientific reports on the status of reportable disease infection to the organisms living in this area. In this study, cyprinid fish and crustaceans in Jeonryu-ri, a region of the Han River estuary, were investigated for the infection by representative reportable communicable diseases(SVC, spring viraemia of carp; KHVD, koi herpesvirus disease; EUS, epizootic ulcerative syndrome; WSD, white spot disease) and parasites. Peripheral fish and primary freshwater fish were observed in Jeonryu-ri with cyprinid caught most frequently. Crustaceans were mostly marine species. No positive bands to any of the reportable diseases were produced in any of the fish and crustacean examined in this study by PCR. No trace of Clonorchis sinensis, a liver fluke potential threat to human health, was detected in any of fish samples. However, many fish were infected by metacecaria of other flukes, and other various parasites such as nematode, cestode, copepod, monosite and acanthocephalan. These results suggest that important aquatic organisms in the Han River estuary is not seriously polluted yet. However, it is important to keep monitoring the diseases since the water quality in this region is constantly changing, and devastating influence of infectious diseases is unpredictable. Further, it is required to expand monitoring area toward upstream and increase the number of fish for examination.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.5 no.3
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• pp.97-103
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• 1972

In this paper, the effects of some additives to the quality of fish cake such as salt, polyphosphate, and starch were tested. Besides, that of washing and alterative heating procedure were also discussed. From the result of quality test by measuring jelly strength and sensory evaluation the product was quite palatable to common, and the addition of salt and starch as 3 and 5 to 15 percent respectively, resulted in the best jelly strength of the product, it was markedly enforced when a small amount of polyphosphate ($0.3\%$) was added. It is suggested for a processing method of carp meat fish cake that meat is to be bleached by wasing at least 8 times repeatedly with tenfold tap water by volume of meat, and that the meat is previously chilled at 2 to $3^{\circ}C$ for so minutes and ground thoroughly with addition of 3 percent of salt, 5 to 15 percent starch, and 0.3 percent polyphosphate, and finally heat processed by two stages: at first, heated for 1 hour at $35^{\circ}C$ and alteratively heated for 30 minutes at $90^{\circ}C$ as the final.

• Journal of Nutrition and Health
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• v.13 no.1
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• pp.59-64
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• 1980

Carp, Cypinus carpio, has been esteemed as one of the most tasty fresh water fishes in Korea. But little study on its food has been reported. The composition of fatty acids, amino acids, nucleotides and their related compounds as chemical component of carp muscle were analyzed by gas-liauid chromatography, amino acid autoanalyzer and high speed liauid chromatography. The fatty acids of the carp muscle lipid consisted of the large amount of $C_{18}\;:\;2,$ $C_{18}\;:\;1,$ $C_{18}\;:\;3,$ $C_{16}\;:\;0,$ $C_{16}\;:\;1,$ acids, small amount of $C_{16}\;:\;2,$ $C_{18}\;:\;0,$ $C_{18}\;:\;4,$ $C_{14}\;:\;0,$ $C_{14}\;:\;1,$ $C_{12}\;:\;0,$ acids, and $C_{13}\;:\;1,$ $C_{13}\;:\;0,$ $C_{20}\;:\;1,$ $C_{17}\;:\;0,$ $C_{15}\;:\;1,$ $C_{17}\;:\;1,$ $C_{22}\;:\;1$ acids were smaller. In fresh carp, the results showed that inosine $17.25{\mu}mole/g$, hypoxanthine $10.06{\mu}mole/g$ were dominant and the content of GMP, IMP, AMP, UMP, CMP were 1.56, 1.36, 0.92, 0.49, $0.34\:{\mu}mole/g$ on dry base, respectively. Histidine and lysine were dominant amino acids in carp extract, having 49.4% (214.6mg%), 33.9% (147.1mg%) of total free amino acid contents, respectively, but the content of glycine, serine, alanine and glutamic acid were low, and arginine, aspartic acid, threonine, proline, valine, methionine, isoleucine, phenylalanine were detected in trace amount. The content of amino acid composition showed that glutamic acid, aspartic acid, lysine, leucine, alanine, valine and arginine were the most abundant amino acids, while such amino acids as glycine, isoleucine, phenylalanine, threonine, histidine, methionine, serine and tyrosine were low, and proline was detected in trace amount.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.177-183
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• 1984

This study aims to find the taste compounds of wild loach, Misgurnis mizolepis, which is important fresh-water fish in this country. In order to elucidate the origin of the taste of wild loach meat, free amino acids, organic bases, nucleotides and their related compounds, organic acids, sugars and minerals were analyzed, and then followed by organoleptic test of synthetic extract prepared on the basis of the analytical data. Sensory evaluations of synthetic extracts prepared by omitting each extractive components were carried out by a triangle difference test, and changes in taste profile were assessed. In free amino acid composition, histidine, threonine, glycine, lysine, alanine were abundant. IMP and AMP were dominant in the wild loach in content. Total creatinine and butyric acid were abundant. As for the minerals, $Na^+,\;K^+,\;Cl^-\;and\;PO_4^{3-}$ were found to be the major ions. From the results of omission test of synthetic extracts the major components which contribute to produce the taste were arginine, glutamic acid, valine, aspartic acid, IMP, succinic acid, $Na^+,\;K^+,\;Ca^{2+}\;Mg^{2+}\;Cl^-\;and\;PO_4^{3-}$.

• Korean Journal of Ichthyology
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• v.7 no.1
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• pp.56-63
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• 1995

Ecological study of the Cynoglossus joyneri was conducted based on the specimens from the western coast of Korea from 1992 to 1994. Ecological characteristics of this species such as gonadal development, occurrence of larvae, stomach contents, and environmental conditions were investigated. Few larvae of Cynoglossus joyneri occurred in Kunsan coast. This coast is influenced by the freshwater input of the Mangyong and Kum River, especially during the summer. Therefore, the larvae of C. joyneri were considered to be spawned and grown during their early life stage in the high saline water in outer bay. Spawning occur from June to September, having the peak spawning period from July to August. Biological minimum size of matured fishes containing mature oocytes is about 143.5mm in total length, which requires about 20 months after hatching. The ranges of total length by age are as follows : 0-ring group(floating stage), 30~70mm ; 1-ring group, 49.0~133.0mm 2-ring group, 128.6~167.0mm ; 3-ring group, 169.0~202.0mm ; 4-ring group, 200.7~240.0mm. The major food items of young fish under 8cm were copepods and invertebrate larvae, and those of adult fishes were annelids(polychaets) in winter, and bivalves and shrimps in summer and autumn. Therefore, it can be assumed that the population of C. joyneri could be reduced due to the decrease of food organisms caused by the continuous reclamation activities in the inner bays of the west coast of Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.298-302
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• 1982

In order to elucidate the taste compounds of wild common carp, Cyprinus carpio, and Korean snakehead, Channa argus, organic acids, sugars ana minerals were analyzed as a part of the study on the taste compounds of fresh-water fishes. Among organic acids, the contents of succinic acid, butyric acid, propionic acid and valeric acid were fairly high, while those of oxalic acid, fumaric acid, maleic acid, tartaric acid and citric acid were trace. As for the sugars, glucose was found to be the most predominant monosaccharide of the species. Extremely small amounts of fructose and arabinose were also detected and inositol and ribose were trace in content. Among minerals, $K^{+},\;Na^{+},\;PO_{4}^{3-}\;and\;Cl^{-}$ were found to be the major ions and small amounts of $Ca^{2+}\;and\;Mg^{2+}$ were detected.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.545-549
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• 1985

The muscles of wild and cultured carp (Cyprinus carpio), and Israeli carp (Cyprinus carpio nudus) were analyzed for the amino acid profiles, in vitro digestibility, predicted digestibility, C-PER and DC-PER. The distribution patterns of the total amino acid profiles in wild and cultured carp were found to be very similar, although there were relatively large differences in lysine, aspartic acid and glutamic acid contents which were higher in the cultured carp. Israeli carp was 2 times as much as wild carp in lysine. The quality of muscle proteins in wild and cultured carp, and Israeli carp was predicted by the in vitro method. The protein quality of Israeli carp was higher than that of wild and cultured carp, whereas there showed a similar tend to protein quality between wild and cultured carp. The contents of hitidine, tyrosine, aspartic acid, alanine and glutamic acid in diet showed stronger positive corelation with the levels of protein deposition than those of protein intake, and those amino acids would greatly influence on amino acid composition of muscle protein in fishes.