EFFECT OF CADMIUM AND COPPER ON SURVIVAL AND REPRODUCTION OF DAPHNIA-PULEX

Acute and chronic toxicity tests were performed using Daphnia pulex wi th copper and cadmium as toxicants. The mean concentration causing 50% mortality in a 48 h acute test was 21 mu g.t(-1) for copper and 78 mu g.t(-1) for cadmium. In the 21 d chronic test, stimulation, recorded as increased offspring per animal (relative to that in the control), w as observed for added copper concentrations of 0,003 mu g.t(-1) to 0,3 mu g.t(-1). Impairment of reproduction occurred at an added copper co ncentration of 3 mu g.t(-1). In the case of the chronic rest on cadmiu m, reproductive impairment at 21 d was observed over the added concent ration range of 0,003 mu g.t(-1) to 3 mu g.t(-1). The no observed adve rse effect level (NOAEL) for chronic toxicity for copper was approxima tely 0,4 mu g.t(-1) and for cadmium <0,003 mu g.t(-1).