Daphnia magna ecotoxicity test with parathion

The toxicity test with organophosphate insecticide - parathion - was determined on neonates (0–6h old) and juveniles (up 96h old) of Daphnia magna, Straus 1820, Clone A. Organisms (10 per test chamber) were exposed to 7 toxicant concentrations plus control in the flow-through system, containing ASTM hard water. Health conditions were assessed every 24 hours in the standard immobilization test and by morphometrical analyze under a light microscope in a special computer program “MultiScan”. The following morphometric parameters were determined on external appearance: length and width of body and of head and also morphological distribution of pigments: green color of filling of gut, and yellow color of lipid droplets in the body. Colors in the body of animals were determined owing to special morphological filters and image processing in computer program.