Incubation of fertilized eggs in water containing 0.001-0.05 ppm of cadmium resulted in decreased swelling of the eggs, extended development time (delayed hatching) and reduced survival of embryos compared with the control. The proportion of normal, live hatched fry also was reduced in Cd 2 + solutions (8-35%) with respect to the control (86-88%). Acute toxicity tests revealed high individual variability of fish tolerance to cadmium; 96-h LC 5 0 results were 0.002 ppm for fish under 10 days, 0.005 ppm 10-20 days, and 0.007 ppm of cadmium over 20 days.