Toxicity of Copper Sulphate (Fungicide) on the African Catfish Fingerlings

Toxicity of Copper Sulphate (CUSO₄.5H₂O) (Fungicide) on African catfish, Hetrobranchus longifilis post fingerlings were evaluated for 96hrs (4days). The experimental fish (H. longifilis) has a mean weight of 2.5 + 0.2g and average length 8.11 + 0.2cm. The median lethal concentration (96 hr C50) value obtained was 3.00g g/L. The upper and lower confidence limits of toxicity were 4.97g/L and 2.14g/L respectively. The threshold value or safe level was 2.00g/L. Statistical analysis of the data collected on equality parameter revealed significant difference between the 96 hr LC 50 at P<0.05 for both dissolved oxygen and free carbon (iv) oxide (C02). PH, acidity and temperature were not significantly different at (P<0.05). During the exposure period, the fish showed such signs as increased opercula movement, darkening of the skin, hyper ventilation, and secretion of mucus, quick jerky movement and no response to gentle producing before death finally occurred. The result indicated that even though CUS04. 5H20 is an important fungicide in agriculture; it should be applied at the appropriate dose as recommended by manufacturers with caution to avoid environmental consequences.