Ecotoxicological investigation of cyanobacterial crude extracts to Daphnia magna under subchronic test conditions

Cyanobacterial blooms often consist of mixtures of microcystin-producing and microcystin-free species, and both can cause unpredictable effects on aquatic organisms. In this work, the subchronic effects of the cyanobacterial crude extracts (CCEs) from microcystin-producing and microcystin-free cyanobacteria with different microcystin concentrations (1, 10, and 50 µgL−1)on Daphnia magna were investigated. The life-history trait responses of D. magna to CCEs were determined based on survival, reproduction, and somatic growth. In addition, the physiological response, represented by the feeding rate of D. magna on green algae (Scenedesmus sp.), after exposure to both types of crude extracts was estimated.