An investigation on the Toxic effects of Malathion (Organophosphate Insecticide) on the Daphnia magna Straus, 1820 (Crustacea, Cladocera) [Malathion (Organik Fosforlu İnsektisit)'un Daphnia magna Straus, 1820 (Crustacea, Cladocera) Üzerindeki Toksik Etkilerinin Araştirilmasi]

The toxic effects of technical grade (95%) malathion and commercial (25%) malathion were investigated on young (? 24 h old) Daphnia magna in static acute toxicity tests (24 and 48 hours). The culture of D. magna and toxicity tests were performed at a temperature of 24 ± 1 °C with a photoperiod of 16h light and 8h dark. To obtain a healthy population, the fecundity of each female in their life cycle were also investigated. Immobilization of daphnids were considered for determination of the 24h / 48h effective concentration (50%). The EC50 values were found by probit method 24h /48h, for technical malathion as 0.8 and 0.028 ppm., for commercial malathion as 0.11 and 0.003 ppm respectively