Uptake and distribution of cadmium in the egg of the teleost, Oryzias latipes

Eggs of Oryzius latipes in the blastula stage were exposed to M/100 artificial sea water which contained cadmium at the concentrations of 0.1, 1.0, 10.0, 20.0 or 50.0 mg 1⁻¹. The 96 h TL₅₀, value for cadmium was estimated to be 20 5 mg 1⁻¹. When the eggs were incubated for 24 h in the M/100 sea water with 10.0 mg Cd 1⁻¹ and then rinsed in glycine buffer solution (pH; 2.0), the cadmium content of the egg decreased markedly. Cadmium levels were determined in parts of the embryonic body, the chorion and the yolk sac. The most cadmium was detected in the chorion (94.6%). Prolonged cadmium exposure revealed that most of the cadmium was absorbed by the chorion and little was detected in the embryonic body and the yolk sac.