Testing the Neem biopesticide (Azadirachta indica A. Juss) for acute toxicity with Danio Rerio and for chronic toxicity with Daphnia magna

Recently, some natural products have been used in the fields as alternative to synthetic compounds, to minimize the negative impacts to the environment. This study aimed to verify the effects of Neem-based bio-pesticide in causing acute toxicity for a fish and chronic toxicity for a microcrustacean. To this end, Danio rerio and Daphnia magna were exposed to various concentrations of a Neem-based oil formulation. In the first experiment, adults of D. rerio were exposed for 96 hours to different concentrations to determine the median lethal concentration (LC 50-96h ). For D. magna , first an acute toxicity test was performed to determine the median effective concentration (EC 50-48h ). Based on the EC 50 established in the acute test, the concentrations for the 21-day chronic toxicity test were determined. Endpoints evaluated were reproduction (number of neonates produced) and size of D. magna . The median lethal concentration for the fish was 0.22 mL L -1 , and the median effective concentration (EC 50 - 48h ) for D. magna was 0.17 mL L -1 . In the chronic test, all concentrations affected reproduction and size of D. magna . The formulation tested may be hazardous to aquatic organisms.