Toxic Effects of Methylene Blue on the Growth, Reproduction and Physiology of Daphnia magna

Methylene blue (MB) is a disinfectant used in aquaculture to prevent and treat fish diseases. However, the release of MB can pose risk receiving water bodies. Zooplankton are most sensitive organisms among aquatic life. Hence, this study examined acute chronic toxic effects on zooplankton using Daphnia magna (D. magna) as test organism provide basic data for assessment. The results show that 48 h-EC50 24 h-LC50 were 61.5 ± 2.3 149.0 2.2 μg/L, respectively. Chronic exposure affected heart rate, beat frequency thoracic limbs, reproductive ability D. at environmental concentrations higher than 4.7 μg/L. cumulative molts, time production first brood, total number living offspring different concentrations, while “abortions” observed high-exposure groups. activity superoxide dismutase was increased, glutathione S-transferase stimulated low inhibited high concentrations. In addition, malondialdehyde content increased with increasing MB. Our findings demonstrate impact reproduction growth freshwater species, well their physiological responses. These have implications establishing guidelines use setting discharge standards.