• Proceedings of the Korean Environmental Health Society Conference
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• 2005.11a
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• pp.179-182
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• 2005

Endocrine disrupting effects of several pharmaceutical products were evaluated with fish. The test pharmaceuticals(caffeine, ketoconazole, acetaminophen and diltiazem) have been often detected in aquatic environment of Korea(from on going study of this research team). We analyzed vitellogenin induction by qualitative (Western blot) and quantitative (ELISA) assay. $17{\beta}-estradiol$ was used as a positive control. Some pharmaceuticals could give effects to male Oryzias latipes. They could induced vitellogenin under exposure of chemicals at male Oryzias latipes.

• Korean Journal of Ichthyology
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• v.25 no.1
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• pp.33-37
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• 2013

A study on the structures of the pharyngeal bones and teeth in two Korean ricefishes, Oryzias latipes and O. sinensis, was carried out to find out interspecfic differences. In the pharyngeal bones, both two species have a pair of upper pharyngeal bone (stilliform shape) and lower pharyngeal bone (rectangular shape). In the lower pharyngeal bones, in particular, the number of the row was 6 to 7 in O. latipes and 5 to 6 in O. sinensis. The pharyngeal teeth also showed different types in two species: O. latipes of a top-hooked type and O. sinensis of a conical type. Through this study, we confirmed that the two Korean ricefishes show distinctive characteristics in the structure of the pharyngeal teeth.

• Environmental Analysis Health and Toxicology
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• v.14 no.4
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• pp.217-222
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• 1999

Changes in certain fish behaviors are known to be very sensitive indicators of sublethal exposure to environmental contaminants. Therefore, behavioral toxicity tests, if properly designed, can be very useful to assess the influence of hazardous chemicals on fish. However, quantitative analysis of xenobiotic-mediated changes in locomotor behavior in fishes are rare, due mainly to the methodological difficulties. In general, fish movement has been known to be hypertrophic or hypotrophic according to the chemicals. As a study of fish behavioral toxicities, we qualified the swimming movement of Oryzias latipes using computer-automated video tracking system. Oryzias latipes was exposed to cadmium of 128 mg/L for 1 hour in a limited aquaria, then the total swimming distance, the average swimming velocity, the histogram of turning angles, and the turning frequency were analyzed. Fish treated with cadmium showed decreased swimming activities, decreased velocity, and decreased turning frequency, which means hypotrophic activity. From these results, the computer-automated video tracking system of this study seems to be a good tool for the evaluation of the potential ecotoxicological studies.

• The Korean Journal of Zoology
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• v.30 no.4
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• pp.379-386
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• 1987

Karyotype of the ricessh Orygias latipes (Temminck et Schlegel) was investigated using 151 specimens of eleven populations in the southern Korea. Based on the karyotype analysis, two distinct chromosomal groups were found. One group, occurring in the Kum River, the Mankyong River, the Dongjin River, the Ysngsan River and the SEmjin River had a diploid chromosome number of 46 and arm number of 70, which contained one pair of "large" metacentric chromosomes. The other group, occurring in the Tamjin River, the Hyongsan River andthe all four island populations observed had a diploid chromosome number of 48 and arm number of 68. These results showed that 0. latipes of 6 inland populations was identical with the Chinese population in diploid number, arm number and presence of "large" metacentric chromosome, while the present species of island populations ana populations of the Tamjn R. and Hyongsan R. was similar to the Japanese population in chromosome number and arm number. The karyotype variation in populations indicated that karyotypes will probably provide useful information in studying zoogeography of this species.phy of this species.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2005.12a
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• pp.87-87
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• 2005

• Korean Journal of Environmental Biology
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• v.30 no.4
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• pp.314-318
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• 2012

The aims of the present study were to estimate the possibility for toxicity test and compare acute toxicity of potassium dichromate in the larva stage of Neocaridina denticulata, Daphnia magna and the juvenile stage of Oryzias latipes. N. denticulate, a freshwater shrimp lives in Korea, is an indigenous species and considered to be useful for toxicity test. D. magna and O. latipes were recommended as a test species for the OECD test guideline. The 96 h-$LC_{50}$ potassium dichromate value was 0.62 mg $L^{-1}$ for the larva stage of N. denticulata and 168.44 mg $L^{-1}$ for the juvenile stage of O. latipes. The 48 h-$EC_{50}$ value was 1.27 mg $L^{-1}$ for the D. magna. The study was confirmed higher sensitivity of the larva stage of N. denticulata to potassium dichromate compared to the D. magna and the juvenile stage of O. latipes.

• Korean Journal of Ichthyology
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• v.18 no.1
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• pp.12-19
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• 2006

To examine the relationship of geological distribution and phylogenetic tree of O. latipes in the Far East, we analyzed cytochrome b (cyt b) gene in the mitochondrial genome. In this study we employed the entire sequence of cyt b of 53 samples collected from nine Korean locations and 117 cyt b data retrieved from the GenBank. From 170 Oryzias latipes cyt b sequence data, 142 different haplotypes were identified and phylogenetic relationship was reconstructed based on the dataset. According to the phylogeny, haplotypes were divided into three major haplogroups A, B and C, and their relationships were well correlated to their distributional patterns. Haplogroup A which is widely distribute in the southern part of Korea is separated in the geographical distribution from the haplogroup B which is found from China to the western part of Korea. Haplogroup C is only found in Japan.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.163-169
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• 2006

The Korean ricefish, Oryzias, consisted of 2 species, O. latipes and O. sinensis. Through investigation on their distributions, it was confirmed that O. sinensis was restricted to western areas, and O. latipes was distributed throughout Korea. Interestingly, Daecheon region near the West Sea was sympatric, existing O. latipes and O. sinensis. In addition to their distributions, O. latipes was well distinguished from O. sinensis as the following morphological characteristics: mean 31 vertebrae (vs. 30), mean 15 gill rakers (vs. 12), lots of dots in both sides of body (vs. absent), and yellowish ventral and anal fins (vs. blackish).

• Journal of Environmental Health Sciences
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• v.26 no.3
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• pp.25-31
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• 2000

In order to assess the accumulation levels of cadmium and other metals(Zn, Cu, Ca and Fe) in fish bodies, an experimental study was performed by raising fry of "Oryzias latipes" in the water containing cadmium 0.03 ppm, cadmium 0.03 ppm + zinc 0.03 ppm and in the tap water(control group) were made. In the results the concentration of Cd in fish bodies were increased with advancing exposure time in Cd 0.03 ppm treated group and 0.03 ppm + Zn 0.03 ppm treated group, but there was no significantly different between both groups with Cd concentration in each week. The concentration of Zn in fish bodies was no changed with advancing exposure time in control group and Cd 0.03 ppm + Zn 0.03 ppm treated group were significantly different from control and Cd 0.03 ppm treated group. The concentration of Cu, Ca and Fe in fish bodies were increased with advancing exposure time, and control group was higher than any other groups. Simple correlation analysis showed that the positive correlation between Cd and Zn, Cu and Ca, Fe, Ca and Fe, but Cd was negative correlation with Cu, Ca and Fe. In conclusion, we investigated a tendency that the concentration of Cd and Zn in fish bodies tended to increase with the lapse of time, but Cu was unchanged and those of Ca and Fe were decreased in administrating the trace dose of Cd and Zn in water. in water.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.279-285
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• 2005

Endocrine disrupting effects of four pharmaceutical products were evaluated with fish. The test pharmaceuticals, i.e., sulfamethoxazole, sulfamethazine, oxytetracycline and tetracycline have been often detected in aquatic environment, but their ecological hazard on receptors of various trophic levels has seldom been evaluated. In the present study, we conducted acute toxicity assays with a fish, Japanese medake (Oryziα lαtipes). The vitellogenin induced in female fish normally, but a endocrine disrupting chemical could give effects even male fish. We have tried 4 pharmaceutic chemicals to find out the endocrine disrupting effects. Sulfamethoxazole 1, 0.5 ppm induced vitellogenin even at male Japanese medaka. Sulfamethazine 10, 5, 1 ppm could induced vitellogenin at male fish. Oxytetracycline 10, 5, 1ppm could induced vitellogenin With the fish. Tetracycline 10, 5 ppm could induced vitellogenin at male fish. Some pharmaceuticals such as sulfamethoxazole, sulfamethazine, oxytetracycline and tetracycline could give effects to male Oryzias latipes. They could induced vitellogenin under exposure range 0.5 ${\sim}$ 10 ppm of chemicals at male Oryzias latipes.