查看文章

Common carp (Cyprinus carpio) of 15–30 g body weight were exposed to copper levels of 0.22 ± 0.07, 0.34 ± 0.12 and 0.84 ± 0.35 μmol · l⁻¹. Oxygen consumption and nitrogen excretion were determined repeatedly for up to 2 weeks of exposure to copper. Critical oxygen concentrations for oxygen consumption as well as for ammonia excretion were determined after 1 week of exposure to copper. Oxygen consumption dropped significantly immediately after exposure to 0.34 and 0.84 μmol · l⁻¹ of copper whereas nitrogen excretion remained stable. After 1 week of continuous exposure to 0.34 μmol · l⁻¹ of copper the oxygen consumption showed an apparent recovery, while the ammonia quotient (AQ = mole to mole ratio of ammonia excreted to oxygen consumed) did not. At a copper concentration of 0.84 μmol · l⁻¹, no recovery was observed. The critical oxygen concentration for oxygen consumption shifted from …