Effects of methylmercury chloride on Rana pipiens tadpoles

Abstract

Rana pipiens tadpoles were allowed to be raised in water containing various concentrations of methylmercuric chloride or were injected with 0.025 ml of 0.1% aqueous solutions of methylmercuric chloride (0.025 mg Hg), every other day for 10 days. All the tadpoles which were raised in water containing more than 0.05 ppm mercury died within 48 hours. The distention of the body cavities and eventual death of these tadpoles was believed to be the result of a disturbance of the osmotic regulatory system by the mercury. Total arrest of further development and differentiation was observed in tadpoles which were raised in water containing 0.001–0.01 ppm mercury. Extensive deposition of blood pigment (hemosiderosis) was observed in the livers of the mercury-injected tadpoles. Such hemosiderotic condition was thought to be predisposed by hemolysis of the red blood cells by mercury followed by severe peripheral edema and hemopoietic reactions in the kidneys of these tadpoles.