Effects of copper and cadmium on growth and yolk utilization in barbel [Barbus barbus L.] larvae

Barbel eggs and fry were exposed from fertilization until 14 days after hatching to 100 μg/l of copper or cadmium. Cadmium, but not copper, significantly reduced larvae survival. Both metals significantly decreased larval growth. The differences in fish body size between the controls and metal-exposed groups increased in time, and were more pronounced in Cd-intoxicated fish. Copper-exposed larvae started exogenous feeding 1 day later than the control. Cadmium-exposed larvae started feeding 4 days after the controls. Both metals reduced yolk utilization rate. The results demonstrated that cadmium was more toxic to barbel larvae than copper.