ACUTE TOXIC EFFECTS OF FOUR HEAVY METALS ON TRIONYX SINENSIS JUVENILES
4 种重金属离子对中华鳖(Trionyx sinensis)稚鳖的急性致毒效应

Acute toxicity of Hg~(2+), Cr~(6+), Cu~(2+), and Zn~(2+) and their joint toxicity on 5-day-old Trionyx sinensis juveniles in water temperature at (27.4±1.3)℃ were studied. Accumulative nature was revealed. The degree of toxicity was in the order of Hg~(2+)>Cu~(2+)>Cr~(6+)>Zn~(2+) as the mortality occurred, from early to late; and the median lethal concentrations (IC_(50)) at 96h were 5.98, 16.42, 28.90, and 91.88mg/L. The joint toxicity of the four heavy metal ions at 96h was closely related to ion species and toxicity intensity. Mathematical model and regression equation were built on the death cumulative prob-ability, the concentration of heavy metal ions, the massive death occurrence time, etc., and are important tools for detecting and forecasting the toxicity and mass mortality.