A simple and rapid method for toxicity evaluation of zinc oxide nanoparticle (ZnO NPs) in benthic animal Hydra magnipapillata

Toxicity evaluation is necessary to investigate the possible risk of chemical or pollutants newly produced such as nanoparticles in the environments. The assessment should apply a method that is effective to determine the toxic concentration and the exposure time of the pollutants in an animal model. This study described three main stages including determining the median lethal concentrations (LC(50)) with Probit program and detecting toxic effects of ZnO NPs in morphology and regeneration observed by the changes in morphology of Hydra magnipapillata (H. magnipapillata). We also provide a strategy for culturing hydra in laboratory condition to use the animal for the experiment. The exposure to ZnO NPs led to the abnormality in regeneration such as formation of extraordinary number of tentacles and bifurcated tips in tentacles and the toxic effects in morphology appeared the clubbing tentacle, slender body, and retracting body column and tentacles by the exposure time. The method described here is simple and useful to evaluate the toxic effects of ZnO NPs using morphological characters in H. magnipapillata and could suggest the concentration and the exposure time for further investigations on cellular and molecular responses of the animal after exposure to other nanoparticles. • A simple method to evaluate the toxic effects of ZnO NPs using morphological characters of H. magnipapillata and other hydra species. • A rapid method to evaluate the toxic effects of ZnO NPs and other nanoparticles in H. magnipapillata.