Studies On The Toxicity And Effect Of Copper Used In Goldfish

The clinicpathologies, histopathologies and ultrapathologies on acute, subacute copper poisoning in goldfish(Black dragon eye) were first Studied Which discussed the toxicity and effect of copper used in fish, thereinto this experiment, the liver and renal ultrastructure changes of copper poisoning goldfish were observed especially. The acute poisoning test was conducted with CuSO₄ concentrations of 3.50 mg/1, 5.30 mg/1, 8.02 mg/1, 12.14 mg/1, 18.37 mg/1, 27.80 mg/1, 42.08 mg/1. The 24h LC₅₀ , 48hLC₅₀, 72hLC₅₀, 96hLC₅₀ for CuSO₄ to goldfish of acute poisoning were 21.92 mg/1, 16.15 mg/1, 13.74mg/l, 9.44 mg/1, respectively. Safe concentration was 0.094 mg/1. The mucus of body surface and gill increased in poisoned fish,and their body color thinned, difficult breath, and death were occurred in bad poisoned sick. When extremity , they showed nerval poisoning sign such as urgent swim, overturn, ankylosis and twitch. Gill thread turgescence, and the structure of some gill thread tip was destroyed, some dark globosity grains or actinomorphic anomaly accreted on it. Granular degeneration, vacuolar degeneration, necrosis ,in liver cells and renal tubular epithelial cells. In acute toxicity experiment of higher CuSO₄ concentration (16.15 mg/1,21.92 mg/1) , There were some blue fioccules In gills and some thin blue mucus at body surface. The subacute poisoning test was conducted for 48 days,with CuSO₄ concentrations of 0.5 mg/1, 1.0 mg/1, 1.5 mg/1, 2.0 mg/1,2.5 mg/1. The mortality were respectively 70%,80%,86.67%,93.33%,100%. The clinic symptom of subacute poisoned fish resembled acute poisoned fish', but there was no blue floccule in gills or mucus of body surface. appetite of subacute poisoned fish reduced and they became thin gradually. The liver and renal ultrastructure changes of acute copper poisoning goldfish were observed. The main alterations showed that electron density of cytoplasm debased, nucleus chromatin concentrated; mitochondrion were vacuolar degeneration, its lumen swollen and its christaes were chaos and decrease ; endoplasmic reticulum were dilatation and rupture; rough endoplasmic reticulum appeared split, degranulation, desaggregation; autophagolysosome added; there were dense grains that had character of hepatolenticular degeneration in cell. In liver cells, the thin bile duct exaggerate, tiny villus break off, bile fill up. In renal tubular epithelial cells, structure of brush border collapsed. The liver cell and renal tubular cell showed to dissolve putrescence. The liver and renal ultrastructure damnifications of acute copper poisoning goldfish had not evidently comeback by 12 days within innocuity water. The liver and renal ultrapathological changes of subacute poisoned fish resembled acute poisoned fish', along with prolong poisoning time, pathological changes aggravated gradually.