Journal of Ecophysiology & Occupational Health

The acute toxicity bioassay test were performed with the detergent “Nirma” on a freshwater catfish ‘ H. fossilis to determine the 24, 48,72 and 96 h LC₅₀ values which was found to be 105.50, 35.25, 30.40 and 23.50 mg L⁻¹ respectively. The calculated harmless (safe) concentration of the detergent “Nirma “ was 1.23 mgL⁻¹. The fish exposed to acute (4.70 mg L⁻¹), subacute (2.35 mg L⁻¹) and sublethal (1.50 mg L⁻¹) concentrations for acute (96h) and both short (15–30 days) and long (45–90 days) terms. The blood and tissue biochemical parameters like serum calcium, protein, cholesterol, chloride and glucose as well as liver and muscle glycogen were estimated. The fish showing decreased levels of serum calcium, protein and liver and muscle glycogen but blood cholesterol, chloride and glucose values of exposed fish increased at acute (4.70 mg L⁻¹), subacute (2.30 mg L⁻¹) and sublethal (1.56 mg L⁻¹) concentrations for acute (96h) and short (15–30 days) terms. The subacute and sublethal concentrations of detergent have no effect on long (45–90 days) term on exposed fish.