• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2001.05a
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• pp.131-131
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• 2001

내분비계장애물질에 대한 검색기법의 하나로 수컷 어류의 교배행위 및 생식력에 대한 in vivo 연구를 시도하였다. 수컷 송사리(Oryzias latipes)에 대표적 에스트로젠인 17$\beta$-estradiol를 2 및 20 $\mu\textrm{g}$/L의 농도로 각 노출군당 5마리씩 14일간 노출시킨 후 각 군당 임의로 2마리씩 선택하여 Prostaglandin F2$\alpha$를 주사한 3마리의 정상 암컷 송사리와의 교배행위를 비디오 카메라를 이용하여 1시간 동안 녹화하여 분석하였다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.307-308
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• 2000

어류에 축적된 유기화합물은 생식소와 생식세포에 직접적인 작용으로 수정을 저해(Spies et al., 1988)하고 부화율(Hose et al., 1982)을 감소시킬 수 있다. Bishenol A(BPA)는 음식용기와 음료 포장재료로 사용되고 있으며, 캔 용기, 병 뚜껑 그리고 물 공급용 파이프 등에 금속을 코팅하는 물질이다. 이 연구는, 내분비장애물질이 생물의 번식력과 종 연속성에 미치는 영향을 규명하는 연구의 일환으로, 송사리, Oryzias latipes의 수정란을 BPA에 침적처리 하였을 때 수정난의 초기발생에 미치는 영향과 송사리 어미에 BPA를 경구투여 하였을 때 산란량과 부화율에 미치는 영향을 번식생물학적 측면에서 탐색하였다 (중략)

• Environmental Analysis Health and Toxicology
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• v.22 no.3
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• pp.197-202
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• 2007

구리는 환경에 광범위하게 존재하며, 생물체에게 필수적인 무기질이지만 고농도로 존재할 경우 독성을 발휘한다. 본 연구는 프로티옴 기술을 응용하여 수서태계에 구리와 같은 중금속의 존재 여부를 신속하게 평가하기 위한 생물지표를 발굴하기 위하여 수행되었다. 즉, 송사리(Oryzias latipes)를 이용하여 여러 농도의 구리용액(0.1, 1, 5 mg/L)에 24시간 노출시킨 다음, 머리부분에서 선택적으로 발현이 증가되는 단백질을 동정하고자 시도하였다. 본 시스템에서 유의적으로 발현이 증가하는 것으로 나타난 단백질은 beta-tubulin, heat shock cognate 70 (hsc70)이었으며, 이 결과의 일부를 semi-quantitative RT-PCR를 이용하여 확인하였다. 이와 같이 구리 처리에 특이적으로 발현이 증가된 송사리 단백질들은 노출평가를 위한 생물지표로서 개발을 위하여 더 연구할 가치가 있는 것으로 평가된다.

• Animal Systematics, Evolution and Diversity
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• v.8 no.2
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• pp.177-182
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• 1992

A ricefish Oryzias latipes sinesis Chen et al. of the family Oryzidae is recorded for the first time from western Korea. The present speciment are similar to O. l. latipes in most morphometric characters, but agree well with the original description of O. l. sinensin based on the diploid chromosome number of 46 with two large metacentric chromosomes and the lesser vertebrae number.

• Applied Biological Chemistry
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• v.45 no.1
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• pp.30-36
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• 2002

A bioconcentration experiment was performed for killifish using nonradioactive and radioactive butachlor. At 0.036 ppm concentration, the highest bioconcentration ratio $(C_f/C_w)$ and BCF at steady state recorded as 296 and 87 respectively. And at 0.0036 ppm concentration, the highest $C_f/C_w$ ratio was 169 and the BCF was 51 at steady state. Considering the experimental variation of the BCF's, the BCF of butachlor was tentatively determined to be $69{\pm}28$. And the $^{14}C-butachlor$ and its metabolites depurated about 50% within 12 hours and 90% within 30 hours after depuration experiment started. And in vivo metabolites, designated as M-I, M-II, and M-III, were found in killifish and the excretes as butachlor was metabolised.

• Korean Journal of Ecology and Environment
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• v.47 no.2
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• pp.82-90
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• 2014

To assess the adverse effects of suspended solids on fishes, the hatching rate of embryo, and survival and growth of larvae were measured with common fish species of river such as crusian carp (Carassius auratus), common carp (Cyprinus carpio) and medaka (Oryzias latipes). Bioassay on hatching rate of embryo was conducted with a range of turbidity as 10 levels from 0.2 to 8,080 NTU. Another bioassay on 4-day larval survival and 21-day larval growth were also conducted with a range of turbidity as 8 levels from 0.1 to 8,260 NTU, and 6 levels from 0.7 to 2,030 NTU, respectively. The hatching rate of C. auratus was not significantly different from that of control at turbidity below 4,040 NTU, whereas it decreased when turbidity was 8,080 NTU (p<0.05). The hatching rate of C. carpio was not affected by concentration of suspended solids. For O. latipes, the hatching rate significantly decreased from 254 NTU (p<0.001) and it was zero when turbidity was 8,080 NTU. The 4-day survival of larvae of all 3 species was not affected by turbidity, while the larval growth of all 3 species was significantly affected. The turbidity effect on the growth of C. auratus and C. carpio was observed from 7 days after the exposure at turbidity level of 145, 143 NTU, respectively. The turbidity effect on the growth of O. latipes was observed from 14 days after the exposure at turbidity level of 254 NTU. The results of this study will provide the basic information for the derivation of water quality criteria on suspended solids for the protection of aquatic ecosystem and the quantitative ecological risk assessment of freshwater environment.

• Journal of Life Science
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• v.23 no.3
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• pp.333-340
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• 2013

This study was performed to determine whether stem bark extract containing saponin of Albizzia julibrissin in the diet influences gonadal maturation and spawning in medaka (Oryzias latipes). The crude extraction containing saponin (HaBC) was partially purified from n-BuOH extraction of A. julibrissin stem bark by Diaion HP-20, Silica gel and Sephadex LH-20 chromatographies. We fed diets supplemented with HaBC to medaka. We then studied the effects of the HaBC supplement on the suppression of gonadal maturation and spawning in female medaka that were reared in aquaria with recirculation systems. In the experiment with immature female medaka, the periods of initiation of gonadal maturation and spawning were delayed in the fish that were fed diets supplemented with at least HaBC 20 mg/g-feed. In the experiment with mature female medaka, the fish that were fed diets supplemented with at least HaBC 20 mg/g-feed had lower GSIs than the control diet group did. The results showed that the growth of the immature medaka was not correlated with the amount of supplementation of HaBC in the diet. However, the condition factors (CF) in the medaka that were fed diets supplemented with at least HaBC 20 mg/g-feed were higher than in the medaka fed on the control diet. We concluded that extracts containing saponin from the stem bark of A. julibrissin have the potential to inhibit gonadal maturation in female medaka, but they did not act as growth stimulation. Further studies are required to determine the mechanism of the action.

• Korean Journal of Ichthyology
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• v.28 no.4
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• pp.215-222
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• 2016

Triploidy was induced in the marine medaka, Oryzias dancena by cold shock treatment ($0^{\circ}C$) of fertilized eggs for 30, 45, or 60 min, applied two minutes after fertilization. The triploid genotype was induced by each of the thermal shock regimes tested. The best result was obtained when the eggs were treated for 45 min, which induced triploidy in all the resulting fish. Triploidy was confirmed using chromosomal and flow cytometer analyses, and erythrocyte measurements. The surface areas and volumes of the erythrocytes of triploid fish were significantly larger than those of diploid fish, and their chromosome number (3N=72) was 1.5 times greater that for the diploids (2N=48). Based on a flow cytometer analysis, the triploid fish had approximately 1.5 times the cellular DNA content (2.40 pg/cell) of the diploid specimens (1.61 pg/cell). Data from this study provide the basis for the development of unique models for studying reproductive confinement in transgenic fish.

• Korean Journal of Environmental Biology
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• v.38 no.2
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• pp.323-331
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• 2020

The method of natural spawning is very passive and inconvenient for the study of developmental engineering in marine medaka, Oryzias dancena. The optimum concentration of human chorionic gonadotropin (HCG) and carp pituitary extract (CPE) for ovulation and spawning, and the injection time for the artificial spawning of marine medaka were analyzed in this study. The success rate, survival rate, and hatching rate were highest with 100IU HCG kg^-1 BW and 5mg CPE L^-1 in both male and female marine medaka (p<0.05). After obtaining unfertilized eggs and sperm by the injection of HCG and CPE into the broodstock of marine medaka, artificial fertilization could be successfully achieved any time fertilized eggs are needed in this species. This result should be useful for developing a study program for marine medaka as an experimental animal.

• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.254-260
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• 2007

In order to evaluate the toxic effects of butachlor, a herbicide widely used for control of weeds in paddy field, on medaka (Oryzias latipes), acute toxicity tests for five developmental stages and early life stage toxicity test of were conducted. As the results of acute toxicity test, $96h-LC_{50}s$ for 1 day, 1 week, 2 weeks, 2 months and 5 months after hatching of O. latipes were 0.68, 0.52, 0.38, 1.09 and $0.45\;mg\;L^{-1}$, respectively. This indicated that the most sensitive stage was 2 weeks after hatching. The early life stage toxicity test showed that no statistically significant hatching period and hatching success of embryo was observed at all concentrations of butaclor. However, 0.05 and $0.1\;mg\;L^{-1}$ of butachlor showed statistically significant post hatching survival with p<0.1. Abnormalities of larva were 2.1, 2.3 and 10% at 0.025, 0.05 and $0.1\;mg\;L^{-1}$ of concentration, respectively. They showed abnormal vertebral axis, craniofacial alteration and retarded yolk-sac resorption. The total length and weight were decreased depending on butachlor concentration the end of test. Weight of larva was showed more sensitive toxic indicator than total length. The toxicological responses of O. latipes to butachlor expressed as LOEC(lowest observed effect concentration), NOEC(no observed effect concentration) and MATC(maximum acceptable toxicant concentration) values were 0.025, 0.013 and $0.018\;mg\;L^{-1}$, respectively.