Metal toxicity to embryos and larvae of seven freshwater fish species--I. Cadmium.

The embryos and larvae of seven freshwater fish were exposed to low concentrations of cadmium in soft water. All species were killed or their growth retarded by concentrations ranging from about 4 to 12 microgram Cd/liter. The larvae were consistently more sensitive than the embryos. The agreement between these results and those from life-cycle chronic toxicity studies indicates that embryo and larval exposures will give reliable estimates of the chronic toxicity of cadmium to additional fish species. A 60-day exposure period appears to be appropriate for determining larval sensitivity to cadmium.