• Korean Journal of Environment and Ecology
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• v.7 no.2
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• pp.192-206
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• 1994

The freshwater fish fauna of the Tokyusan National Park was censused during June 1993 to November 1993 at 9 sampling sites to establish baseline data for natural conservation program on the National Park. Seventeen species included 7 Korean endemic species and/or subspecies(Acheilognaths koreunus, Squazidus gracilis majimae, Microphysogobio yaluensis, Phoxinus kumganensis, Cobitis koreensis koreensis, Silurus microdorsalis and Odontobutis platycephala) belonging to 5 families were collected in this region. Sixteen species were found in Kumkang and 8 species were found in Naktongkang, however, common species were Squalidus gracilis majimae, Microphysogobio yaluensis, Puntungia herzi, Moroco oxycephalus, Zucco temminckii, Misgurnus anguillicaudatus and Odontobutis platycephala. Dominant species of this region were Moroco oxycephalus, Zacco temminckii, Odontobutis platycephala. The final aims of this study were not only accumulate baseline data on the osteology of Korean freshwater fishes which were collected at those streams during June 1993-November 1993 with soft X-ray radiography, but also evaluate the suitability of osteological analyses on the environmental damage to fish.

• Solar Energy
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• v.11 no.3
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• pp.31-36
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• 1991

We have maintained the optimum water temperature for misgumus in winter season by solar thermal heating energy. The optimum temperatures for the misgumus anguillicaudatus were experimentally estimated, i.e. for the total length $4{\sim}5cm$ and body weight $1{\sim}2g$, the optimum temperature was $18{\sim}20^{\circ}C$. For the total length $5{\sim}7cm$, body weight $2{\sim}3g$ was $20{\sim}22^{\circ}C$ and for the total length $7{\sim}9cm$, body weight $4{\sim}6g$ was $22{\sim}24^{\circ}C$. The smaller misgumas($1{\sim}3g$) grows relatively slow but the bigger one($4{\sim}8g$) grows relatively fast and total average body weight increment was about $30{\sim}50g$ per month.

• Korean Journal of Environmental Agriculture
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• v.7 no.2
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• pp.117-123
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• 1988

This study was initiated to understand the mechanism of selective toxicity of diazinon and carbofuran to killifish and loach. Conventional LC50 was calculated from fish test. IC50 with acetylcholinesterase activity was estimated using whole body and wet brain homogenate of the two fish species. Acetylcholinesterase activity of killifish was approximately twice as high as that of loach. The selective toxicity of diazinon to killifish and loach was partly (14 : 4) explained by the IC50 of diazoxon, a toxic metabolite of diazinon. IC50 of carbofuran also partly (14 : 3.4) contributed to the selectivity. These result suggested that the enzymatic method might be utilized as a screening tool for the chemicals affecting fish species of environmental concern with certain limitations which should be overcome in future studies.

• Korean journal of applied entomology
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• v.38 no.2
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• pp.165-169
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• 1999

A study was performed on the susceptibility of Abate@ and Abate-S@ against 3rd instar larvae of 5 species of mosquitoes including Anopheles sinensis, Aedes dorsalis, Culex inatomii, Cx. pipiens pallens, Cx. tritaeniorhynchus and mosquito larvivorous fishes such as Chinese muddy loaches (Misgurnus muzolepis) and crucian carps (Carassius carassi~4s) in September, 1998. Cx. pipiens larvae showed that the LC5os of both Abatea and Abate-Sa were 0.006 ppm. The LC95 values of this mosquito species appeared 0.070 pprn of Abate@ and 0.035 pprn of Abate-S@ which were more susceptible than the dosage (1.0 ppm) recommended from WHO. An. sinensis larvae appeared 0.009 pprn of LC50 and 0.025 pprn of LCgs. The larvae of Cx. inatomii and Ae. dorsalis showed the most highly susceptible to Abate-S@ among the 5 mosquito species with LC50 values of 1.9 x pprn and 1.1 x pprn respectively, and the LC95 values were 5.2 x 10-hppm and 1.4 x ppm, respectively. On the other hand, Cx. tritaeniorhynchus appeared least affected by Abate-Sa. and was brought 0.048 pprn of LC50 and 0.808 pprn of LCg5. These two insecticides were much less toxic to the fishes than mosquito larvae showing the LC, value of Chinese muddy loaches at 24.145 pprn of Abate and 10.750ppm of Abate-S@. This fish species showed that the LCsos of Abate@ and Abate-S@ were 27.567 pprn and 14.775 ppm, respectively. In case of crucian carps, their LC, values were 7.914 pprn of Abate@ and 6.480 pprn of Abate-S@. Therefore, the maximum safe dosages of the insecticides to the fishes were 8 times as high as the values of LCg5 of the mosquito larvae. This study suggests that Abate@ and Abate-S@ demonstrated highly potential insecticides for further larger scale operational integrated control in some proper aquatic places if other aquatic invertebrates are also safe to the insecticides.

• Korean Journal of Environmental Biology
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• v.36 no.1
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• pp.1-10
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• 2018

The objective of this study was to identify the effects of farming practices on the Misgurnus anguillicaudatus population, including their habitat characteristics, length frequency and the length-weight relationships of M. anguillicaudatus population; this study investigated the differences of the population living in environment-friendly (EFP) and conventional paddy fields (CP). As the result of age distribution by length frequency of M. anguillicaudatus, the EFP showed various age distributions which were not present in the CP. In particular, the age $0^+$ (28-51 mm) of individuals in the CP were significantly lower than those in the EFP. In May, the number of individuals was similar in CP and EFP, which led to the assumption that the M. anguillicaudatus population living in a shallow depth was killed by rotary and tillage works. The regression coefficient (b) in relation to the length-weight of M. anguillicaudatus population was 3.0, which appeared relatively stable as a habitat condition in the CP and EFP, except in June. The condition factor for M. anguillicaudatus population in the CP and the EFP showed a relatively stable monthly population, except in June which was likely to be influenced by the stress to lay their eggs or chemicals such as the use of pesticides. This change of habitat characteristics and length-weight relationship on M. anguillicaudatus population in rice paddy fields was influenced by farming practices as well as the time of year.

• Journal of fish pathology
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• v.18 no.1
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• pp.67-80
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• 2005

Phosphoinositide-specific phospholipase $C\delta$ $PLC\delta$) plays an important role in many cellular responses and is involved in the production of second messenger. The present study was conducted to obtain the biochemical characteristics of the expressed recombinant $PLC\delta$ in E. coli cloned from Misgurnus mizolepis and partially purified $PLC\delta$ enzymes from liver tissues of M. mizolepis (wild ML-$PLC\delta$). The ML $PLC\delta$ gene was cloned and expressed under the previous report (Kim et al., 2004), and purified the recombinant protein by successive chromatography using $Ni^{2+}$-NTA affinity column and gel iltration FPLC column. The wild ML-$PLC\delta$ protein was solublized with 2 M KCI and purified by successive chromatography on open heparin-Sephagel and analytical TSKgel heparin-5PW. Both the recombinant and wild ML-$PLC\delta$ form of protein showed a concentration-dependent PLC activity to phosphatidylinositol 4,5-bis-phosphate (PIP$_2$) or phosphatidylinositol (PI). Its activity was absolutely $Ca^{2+}$- dependant, which was similar to mammalian $PLC\delta$ isozymes. Maximal PI-hydrolytic activations of recombinant and wild ML- TEX>$PLC\delta$ was at pH 7.0 and pH 7.5, respectively. In addition, the enzymatic activities of recombinant and wild ML-$PLC\delta$ were increased in concentration-dependent manner by detergent, such as sodium deoxycholate SDC), phosphatidylethanolamine (PE) and phosphatidylcholine (PC). The activities decreased in contrast by a polyamine, such as spermine. Western blotting showed that several types of $PLC\delta$ isozymes exist in various organs. Taken together our results, it suggested that the biochemical characteristics of ML-$PLC\delta$ are similar with those of mammalian $PLC\delta1$ and ${\delta}3$ isozymes.

• 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 Animal Reproduction
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• v.16 no.1
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• pp.63-76
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• 1992

This study was carried out to investigate the appearance time of the second polar body for producing Gynogenesis or Triploid which could be obtained by arresting the second polar body by cold shock, and then blastoderm was used to measure fertility that revealed the nature of oogenesis, the effects of water temperature on fertility, hatchability, abnormality, viability and growth rate, and the water temperature and the breeding methods to prevent early death of larvae in Korean loach(Misgurnus anguillicaudatus) ; the results obtained in this study were summarized as follows. The second polar body was observed ont he surface of plasma disc close to micropyle within 10~40 min after fertilization at 29$^{\circ}C$. Artificial inseminatin had to be done immediately after the egg spawning because the spermatozoa of loach their mobility within 2 minutes when they were exposed to water. The amount of time needed to reach at blastoderm stage was 12 hours if fertilized eggs were incubated at 16$^{\circ}C$, 8 hours at 19$^{\circ}C$, 6 hours at 21$^{\circ}C$, 5 hours at 23$^{\circ}C$, 4 hours at 26$^{\circ}C$ and 3 hours 30 min at 29$^{\circ}C$ showing the shorter time for development of eggs at higher temperature. Fertilization rates in water temperatures of 19$^{\circ}C$, 21$^{\circ}C$, 23$^{\circ}C$, and 26$^{\circ}C$ were higher than those of water temperatures, 16$^{\circ}C$ and 29$^{\circ}C$. Water temperatures at 19$^{\circ}C$, 21$^{\circ}C$, and 23$^{\circ}C$ showed higher hatching rates that those of 16$^{\circ}C$, 26$^{\circ}C$, and 29$^{\circ}C$, while abnormal rates in 16$^{\circ}C$, 19$^{\circ}C$, 21$^{\circ}C$ and 23$^{\circ}C$ were lower than that of 26$^{\circ}C$ and 29$^{\circ}C$. Water temperatures at 16$^{\circ}C$, 19$^{\circ}C$, 21$^{\circ}C$, 23$^{\circ}C$ and 26$^{\circ}C$ respectively, were more different than 29$^{\circ}C$ in survival rates. The embryos were hatched at 72 hours after fertilization in 16$^{\circ}C$ water temperature, 48 hours in 19$^{\circ}C$, 40 hours in 21$^{\circ}C$, 32 hours in 23$^{\circ}C$, 25 hours in 26$^{\circ}C$, and 16 hours in 29$^{\circ}C$. Within three days after hatched out, the larvage grew 3mm in total length, the yolk granules were entirely consumed and the head and the trunk became thicker. Within 45 days after hatched out, the larva grew 25mm at 29$^{\circ}C$, 21mm at 26$^{\circ}C$, 16mm at 23$^{\circ}C$, 15mm at 21$^{\circ}C$, 12mm at 16$^{\circ}C$ in a 30 litreglass aquarium.

• Korean Journal of Environmental Agriculture
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• v.30 no.1
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• pp.37-42
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• 2011

BACKGROUND: The purpose of this study was to evaluate ecological function of small-scale pond and movement characteristics of mudfish (Misgurnus mizolepis) during midsummer drainage period. METHODS AND RESULTS: In situ experiments were performed in the paddy field with mudfish under the condition of midsummer drainage from 13 July to 29 July 2010. The mudfish used in this experiment is approximately 1,000 individuals with a cut tail. Mudfishs were released in the rice field before midsummer drainage and caught again in the small-scale pond and the paddy field after midsummer drainage. Results showed that the abundance of mudfish was higher in drainage canal than small-scale pond at the early stage of midsummer drainage, because flow was formed toward the drainage canal. In that time, 3% of the total marked mudfish were captured at outlet of drainage canal. As the paddy was drying, 5% of total marked mudfish moved to the small-scale pond during midsummer drainage period. Contrary to the general hypothesis, the marked mudfish was not found in holes in paddy field.of total caught in the small-scale pond ingested mainly animal prey, and it's frequency of empcy stomach was 10%.oOn the other hand, all m total collected in the paddy field showed empcy stomach. It was apparent from the experiment that m total are eeldng normally in the small-scale pond, while m total are not eat properly in paddy field. CONCLUSION(s): As the paddy was drying, mudfish moved to the small-scale pond during midsummer drainage period but mudfish was not found in holes in paddy field. It can be concluded that small-scale provides a shelter and prey to mudfish in the midsummer drainage period.

• Microbiology and Biotechnology Letters
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• v.6 no.1
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• pp.41-46
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• 1978

Piscicidal substance produced by Streptomyces sp. isolated from soil was toxic against various kinds of fish. After extraction with CH$Cl_3$ from the culture medium, the substance was purified by avicel column chromatography. In order to test toxicity, various kinds of fish were subjected to the acqueous solution of 100 us of the substance per liter of water. Generally, the substance was toxic to most fish, but Macropodus chinenes and Misgurnus mizolepis are resistant to the substance than Gobius similis and Pseudorasbora parva. The substance was stable at pH range, 3.0 to 7.0, but labile at alkaline pH, and to heat as well. Succinic dehydrogenase on most of tissue cell of Cyprinus carpio was inhibited by this substance strongly, but spinal cord was not inhibited. By addition of Cu and Pb salts to the culture medium, piscicidal substance producibility was activated.