Cyanobacteria (blue green algae) blooms formed in natural water resources due to the environmental pollution produce toxic compounds as secondary metabolites, causing health hazards to both humans and other living beings. Microcystin is a well-known toxin produced by cynobacteria. The present study was undertaken to evaluate varying concentrations and exposure times of two different forms of microcystin, viz., -LR (MCLR) and -LA (MCLA), on the motility and seizure-like behavior of planarian (Dugesia japonica). Compared to control, reduced motility was observed in both the MCLR or MCLA treated groups, but did not differ significantly with increasing concentrations of microcystin. However, the number of seizure-like behaviors were increased dose-dependently in planarian exposed to MLCR or MCLA. Exposure time to microcystine also affected the motility and seizure-like behaviors of planarians; 24 hrs incubation with MCLR, and 48 and 96 hrs exposure to MCLA, showed significantly (p<0.05) lower motility, as compared to the control. Assessing regeneration of the planarians revealed the simultaneous completion of eye formation at day 9 in planarians incubated in the absence or presence of MCLR or MCLA, thereby indicating that exposure to microcystin has no effect on the process. In conclusion, we determined that exposure to microcystins resulted in decrease in the number of motility, and induced abnormal behavior pattern in planarians. Further studies are required to identify the toxicity of microcystin that affects aquatic ecosystems.

Introduction
Materials and Methods
    Laboratory animals and reagents
    Measurement of motility and seizure-like behaviorpatterns
    Observation of eye formation in planarians
    Data analysis
Results
    MCLR and MCLA attenuate the motility of planarians
    Exposure time of MCLR and MCLA affect to thebehavior of planarians
    Eye formation in the absence/presence of microcystin
Discussion
References

• Young-Joo Yi(Department of Agricultural Education, College of Education, Sunchon National University)
• Yeon-Hwa Kim(Division of Biotechnology, College of Environmental and Bioresource, Jeonbuk National University)
• A. A. Dilki Indrachapa Adikari(Department of Agricultural Education, College of Education, Sunchon National University)
• Seung-Tae Moon(Department of Agricultural Education, College of Education, Sunchon National University)
• Sang-Myeong Lee(Laboratory of Veterinary Virology, College of Veterinary Medicine, Chungbuk National University) Co-corresponding author