The survivals of the Moina macrocopa and S. mixtus exposed to antimony were expressed as a percent of the survival of crustaceans compared to the control treatment. Antimony caused the concentration-related inhibition of survival and mobilization for two planktonic crustacea. Fig. 4 showed the effect of antimony on survival and mobilization of Moina macrocopa. As listed in Table 1, the 24-h and 48-h LC50 (EC50) values of antimony for Moina macrocopa were 12.83 (12.41) and 8.95 (8.94) mg L−1, respectively.