• Journal of Korean Society of Environmental Engineers
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• v.38 no.4
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• pp.193-200
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• 2016

Water flea is a widely used test species in the aquatic ecotoxicity test. In Korea, D. magna is currently used as a standard test species, however that do not inhabit in the Korean aquatic ecosystem. In this study, Daphnia galeata, which is a dominant species in the Korean aquatic ecosystem, was collected from domestic lake and investigated to suggest the D. galeata for ecotoxicity assessment in Korea. We investigated the characteristics, life span, and toxicity sensitivity compared with D. magna. The life span test of D. galeata was performed in this study, and then the results were compared to the sensitivity with D. magna to confirm the applicability for ecotoxicity assessment. The 48h-L(E)C50 values for seven heavy metals (As, Cd, Cr, Cu, Hg, Ni, and Zn) of D. galeata and D. magna were collected and analyzed. As a results, shorter lifetime, less reproduction, smaller body size of D. galeata were observed compared with D. magna. D. galeata was similar or more sensitive than D. magna for seven heavy metals. Therefore, we propose that D. galeata is a suitable test species for ecotoxicity testing in Korea.

• Korean Journal of Environmental Biology
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• v.34 no.2
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• pp.116-123
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• 2016

The ecotoxicity tests for metal plating wastewater were conducted using Daphnia magna (D. magna) and Euglena agilis (E. agilis). Evaluation for sources of toxicity was performed by 1) Correlation analysis between the concentration of individual metals in the metal plating wastewater and the toxic effects on D. magna, 2) Toxicant identification evaluation methods including graduated pH method, EDTA procedure and sodium thiosulfate procedure, 3) Comparison of toxic effect value ($EC_{50}$ or $LC_{50}$) of individual metal on D. magna and it's concentration in the metal plating wastewater. To evaluate the possibility of E. agilis, a Korean domestic organism, as a test model organism for metal plating waste water, E. agilis toxicity test was also assessed using on-line euglena ecotoxicity system (E-Tox system). Based on toxicant characterization test using D. magna, it was expected that SS, oxidants and heavy metals are responsible for toxicity of metal plating waste water. Especially Cu, Hg, and Ag were the major cationic metals that caused toxicity. E. agilis is less sensitive than D. magna based on the $EC_{50}$ value however it shows prompt response to toxic test substances. E. agilis shows even a significant effect on the cell swimming velocity within 2 min to toxic metal plating wastewater. Our study demonstrates that E. agilis test can be a putative ecotoxicity test for assessing the quality of metal plating waste water.

• Korean Journal of Environmental Biology
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• v.34 no.2
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• pp.91-96
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• 2016

This study presents the potentiality of harmful algal bloom (HAB) control through the zooplankton, Daphnia magna. In case of co-cultivated D. magna with cyanobacteriums (Microcystis aeruginosa, Anabaena variabilis, and Limnothrix planctonica), the D. magna showed the $80.2{\pm}4.2%$, $39.7{\pm}4.0%$, and $25.9{\pm}10.9%$ of control efficiency for M. aeruginosa, A. variabilis and L. planctonica, respectively. Furthermore, algal control was investigated by using supernatant including metabolite/secretion of D. magna. The algal control efficiencies of supernatant were recorded as $24.9{\pm}9.9%$ and $8.9{\pm}4.0%$ for M. aeruginosa and A. variabilis, respectively. From the results of present study, it may be possible to provide a feasible way for development of eco-friendly HAB control methods.

• Environmental Analysis Health and Toxicology
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• v.23 no.2
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• pp.79-85
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• 2008

본 연구에서는, 세리아($CeO_2$), 실리카($SiO_2$) 및 티타늄($TiO_2$) 나노입자의 유전독성과 생태독성 평가를 위하여 바이오 모니터링에 널리 이용되는 수생생태 감시종인 Daphnia magna를 사용하였다. 합성한 나노입자 세리아와 공업적으로 상용되는 실리카 및 티타늄을 유전독성 및 생태독성평가에 이용하였다. 세리아의 경우, D. magna의 DNA의 파괴가 증가함을 통해 세리아의 유전독성 가능성을 확인할 수 있었으나, 실리카 및 티타늄의 경우에는 두 물질 모두 유전독성 영향이 나타나지 않았다. 실리카는 DNA에는 영향을 미치지 않는 것으로 보이나, 실리카에 노출된 D. magna의 사멸은 증가하는 결과를 보였다. 그러나, 티타늄에 노출된 D. magna에서는 유전독성 및 생태독성 인자의 유의적인 변화를 관찰할 수 없었다. 이상의 전체 결과를 통하여 예상할 수 있는 것은 세리아 나노입자가 D. magna에 유전독성을 일으킬 수 있다는 점이다. 이 결과는 나노입자가 광범위하게 이용되고 있으나 독성 관련 자료가 미약한 현재에 수생태 관련 독성 연구 결과로서 이바지 할 수 있을 것으로 여겨진다.

• Environmental Engineering Research
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• v.11 no.5
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• pp.277-284
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• 2006

The genetic toxicity of environmental pollutants, namely, nonylphenol (NP), bisphenol A (BPA) and chloropyriphos (CP) was investigated in aquatic sentinel species, freshwater crustacean, Daphnia magna, and larva of aquatic midge, Chironomus tentans, using Comet assay. Physiological effect of such pollutants was also investigated by studying the specimens' rates of reproduction, growth and survival. Acute toxicity results showed that, as expected, Daphnia was more sensitive than Chironomus to chemical exposure. The order of acute toxicity was CP > NP > BPA in D. magna and NP > CP > BPA in C. tentans. BPA may exert a genotoxic effect on D. magna and C. tentans, given that DNA strand breaks increased in both species exposed to this compound, whereas NP- and CP-induced DNA damage occurred only in C. tentans. In vivo genotoxic data obtained in aquatic sentinel species could provide valuable information for freshwater quality monitoring. The experiments with NP-exposed D. magna showed that the pollutant has long-term effects on reproduction, whereas no short-term effect on DNA integrity was found, being an example of a false-negative result from the biomarkers perspective. This result could be interpreted that other mechanism than genetic alteration might be involved in NP-induced reproduction failure in D. magna. False-positive results from the genotoxic biomarker obtained in BPA-exposed D. magna and in NP-exposed C. tentans make it difficult to use DNA integrity as an early warning biomarker. However, as the mere presence of genotoxic compounds, which are potentially carcinogenic, is of high concern to human and ecosystem health, it could also be important to rapidly and effectively detect genotoxic compounds in the aquatic system in ways that do not necessarily accompany a higher level of alteration. Considering the potential of D. magna and C. tentans as bioindicator species, and the importance of genotoxic biomarkers in ecotoxicity monitoring, DNA damage in these species could provide useful information for environmental risk assessment.

• Journal of Environmental Science International
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• v.20 no.7
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• pp.811-818
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• 2011

Daphnia Magna Stratus has been widely accepted as useful species for estimating the toxicity of chemicals to aquatic invertebrate and recommended as species for the testing chemicals from the international guideline as well as Korean guideline. The study was performed for the acute toxicity test by using water flea(D. Magna) for effluents from several wastewater treatment plants and drainage canals in GyeongBuk area. Five heavy metals, 1,4-Dioxane and Perchlorate were tested. Most Toxicity Units(TU) of Industrial wastewater effluents were less than 1 which means effluent was not toxic to D. Magna. However, effluents containing 1,4-Dioxane and Perchlorate were significantly toxic to D. Magna. Therefore, facilities should reduce the 1,4-dioxane since new regulations will force them after the year of 2011.

• Environmental Engineering Research
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• v.15 no.1
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• pp.23-27
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• 2010

Genotoxic- and ecotoxic assessments of silver nanoparticles (AgNPs) were conducted on the freshwater crustacean Daphnia magna. AgNPs may have genotoxic effects on D. magna, given that the DNA strand breaks increased when exposed to this nanoparticle. Increased mortality was concomitantly observed with DNA damage in the AgNPs-exposed D. magna, which suggests AgNPs-induced DNA damage might provoke higher-level consequences. The results of the comparative toxicities of AgNPs and Ag ions suggest that AgNPs are slightly more toxic than Ag ions. Overall, these results suggest that AgNPs may be genotoxic toward D. magna, which may contribute to the knowledge relating to the aquatic toxicity of AgNPs on aquatic ecosystems, for which little data are available.

• Journal of Ecology and Environment
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• v.30 no.4
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• pp.319-324
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• 2007

To investigate the impacts of transgenic rice on freshwater organisms, we conducted two life table experiments using Daphnia magna for fifteen and twenty days, respectively. We examined life history traits such as population growth rates (r), reproductive rates ($R_0$), generation times, and survivorship. In the first experiment, we used non-drought-stressed transgenic and non-transgenic rice harvested in 2005. In the second study, we used non-transgenic and transgenic rice harvested in 2006 following drought stress. Each experiment involved three treatments in which D. magna neonates were fed with Selenastrum capricornutum (control treatment) and S. capricornutum with 5% aqueous extracts of non-transgenic rice (N-T) and transgenic rice (T). In the first experiment, D. magna showed reduced population growth rates and lowered fecundity in the N-T and T treatments. In the second experiment, D. magna receiving both transgenic and non-transgenic rice extracts showed very high mortality, low population growth rates and reproduction rates. We could not detect any significant negative effects of extracts from transgenic rice on D. magna life history traits at 95%.

• Journal of the Korean Magnetic Resonance Society
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• v.25 no.2
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• pp.12-16
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• 2021

Daphnia magna is used as target organism for environmental metabolomics. The metabolome of D. magna was studied with NMR spectroscopy. Most studies used the extract of D. magna, but the reproducibility cannot be obtained using extracted sample. In this study, lyophilized D. magna samples were analyzed with two different ¹H NMR techniques, HR-MAS on intact tissues and solution NMR on extracted tissues. Samples were measured three times using 600 MHz NMR spectrometer. Metabolite extraction required more than twice as many D. magna, but the metabolite intensity was lower in solution NMR. In the spectra of HR-MAS NMR, the lipid signal was observed, but they did not interfere with metabolite profiling. We also confirmed the effect of swelling time on signal intensities of metabolites in HR-MAS NMR, and the results suggest that appropriate swelling should be used in lyophilized D. magna to improve the accuracy of metabolite profiles.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.11a
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• pp.175-178
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• 2005

본 연구는 물벼룩을 환경 중 UV-B와 유사한 강도에 노출시켜 8세대 이상 적응시킨 후 Daphnia magna의 UV-B 적응이 광독성 오염물질의 독성 민감도에 미치는 영향을 관찰하였다. UV-B에 적응된 D. magna는 UV-B와 Cu 동시 노출 시 자외선에 적응되지 않은 D. magna에 비해 높은 저항성을 보였다(p<0.1). 그 이유는 D. magna가 UV-B에 적응되는 과정에서 oxidative stress에 대한 방어/회복 능력이 증가하여 동일한 ROS를 생성하는 Cu에 노출되었을때 효과적으로 저항할 수 있었기 때문으로 해석된다. Pyrene, fluoranthene, anthracene, As, Cd, Ni은 독성이 증가하거나 동일하게 나타났다.