Short-term and long-term survival studies in Rana tigrina tadpoles with reference to methyl parathion toxicity.

Toxicity of methyl parathion was studied on survival of Rana tigrina tadpoles. The LC50 values for short-term (upto 96 h) and long term studies (hatching to froglet) were determined. The LC50 values for 96 h and the total larval period were 4.36 and 1.30 ppm respectively. The toxicity of methyl parathion enchanced in relation to increase in concentration and duration. Teratological defects such as scoliosis and failure in emergence of fore limb were noticed. Safe levels were calculated for short-term (0.1 ppm) and long-term (0.03 ppm) studies. The present work stresses the neccessity of long term study especially for the developing amphibians.