Acute Toxicity of Acetamiprid and Inducement to Micronuclei and Nuclear Anomalies in Erythrocytes of Bufo gargarizans Tadpoles

Acute toxicity of acetamiprid on Bufo gargarizans tadpoles was studied by using the semi-static exposure method. Based on the study,the micronuclear test was used to study the inducement of different concentrations of acetamiprid( 0. 001,0. 005,0. 009,0. 013,0. 017 mg·L- 1) to micronuclei and nuclear anomalies in erythrocytes of Bufo gargarizans tadpoles by using the semi-static and static exposure methods. The results showed that 24,48,72,96 h ρLC50values of acetamiprid for the tadpoles were 0. 544,0. 095,0. 058,0. 036 mg · L- 1,respectively. When the tadpoles exposed to acetamiprid with the concentration lower than the safe concentration( 0. 003 6 mg·L- 1) for 7 days,there were no significant differences in the micronuclei rate and nuclear anomaly rate in their erythrocytes between the tested and control groups. In the semi-static test,the micronuclei rate and nuclear anomaly rate of tadpoles increased with the increasing acetamiprid concentrations and the exposure time. The exposure to acetamiprid of 0. 005 mg·L- 1for 3days resulted in significant increases in micronuclei rate and strong significant increases in nuclear anomaly rate in the tadpoles. In the static test,the exposure to acetamiprid of 0. 005 mg·L- 1for 3days resulted in significant increases in micronuclei rate in tadpoles; and in the tested groups,the nuclear anomaly rates reached the highest values after the exposure for 3 ~ 5 days,and then descended,but still higher than the control groups. The results of this study indicated that the tadpoles may partly repair the body status with the decline of the drug effect,and increase of micronuclei rate and nuclear anomaly rate may be potential sensitive indicator in evaluating the applied safety of acetamiprid.