Changes in Copper Content of Allogynogenetic Silver Crucian Carp after Application of Copper Sulfate to Fishponds

Copper sulfate was applied to freshwater fishponds containing allogyno- genetic silver crucian carp and changes in the copper content in fish tissues were measured. The copper content in blood, gill, amd liver went up quick- ly, but remained high for a relatively short time. Twenty-four hours after application, the copper content in the gill and liver reached their highest lev- els, 4.846 mg/kg and 6.624 mg/kg, respectively. The copper content in the blood reached its maximum of 22.125 mg/l three days after application. The copper content in the kidney also reached its maximum, 17.472 mg/kg, on day 3 but the high copper content prevailed until the end of the 20-day observation. The copper content in the muscle reached its maximum, 1.873 mg/kg, on day 7 and its minimum, 0.6 mg/kg, after two weeks