Toxicity influence of dichlorvos and butachlor on Rana guentheri tadpoles.

The acute toxicity effect of Rana guentheri tadpole and the influence of testicular growth by dichlorvos and butachlor were studied adopting standard determination technique of aquatic biological toxicity. Under the test condition of water temperature 24~25℃, the 24h LC50、48h LC50、72h LC50 and 96h LC50 of dichlorvos on the tadpoles were 9.104, 8.064, 6.304, 5.680mg/L, respectively; and those of butachlor on the tadpoles were 1.400, 0.860, 0.795, 0.735mg/L, respectively. The testicular volume of the tadpoles exposed at low dosage of dichlorvos (1.42mg/L) and butachlor (183.75×10-3mg/L) solutions, reduced 68.14% and 68.27%, respectively. The influence of pollutants on the frog gonad growth might lead to decline of amphibian animal population.