Acute and subacute toxicity of copper sulfate pentahydrate (CuSO(4)5.H(2)O) in the guppy (Poecilia reticulata).

Chemicals are used for treatment of aquatic diseases, but there is little data available about copper sulfate in small ornamental fish. The aim of the present study was to determine the TLm(24h) and evaluate the toxicity of copper sulfate in the guppy (Poecilia reticulata). The fish were subjected to an acute toxicity test for 24 hr, and the results showed a TLm(24h) value of 1.17 ppm. Severe hyperplasia and exfoliation of the epithelial cells of gill lamellae and obstruction of the internal cavities of renal tubules with necrotized renal epithelial cells sloughed from the basement membrane were observed. However, no significant changes, except for mild curling of gill lamellae, were found in a subacute toxicity test in which fish were exposed to 1/10 of the TLm(24h) value for 1 week. Therefore, use of less than 0.12 ppm of copper sulfate may be recommended as a therapeutic level.