The toxicity of commercial detergent effluent, a household cleaning agent was investigated with emphasis on its effects on the Docosahexaenoic acid (DHA) of juvenile Makerlfish with the mean weight of 15+0.3kg and standard length of 8.0+0.5cm. After series of range finding test, the fishes were exposed to lethal concentrations of 0.00mg/l, 0.01mg/l, 0.02mg/l, 0.003mg/l, 0.004mg/l and 0.005mg/l and as well as sub-lethal concentrations 0.000mg/l, 0.002mg/l, 0.003mg/l, 0.004mg/l,005mg/l and 0.006mg/l of detergent effluent for 30days in a renewal boassay procedure. The median lethal concentration (LC50) values for lethal and sublethal test were 0.0166mg/l and 0.0028mg/l respectively.
Respiratory disturbance, erratic swimming, los of weight, lethargies and sudden death were obsened in the exposed fish and these varied greatly with difference in concentration of toxicant and this shows that mortality increase with an increase in concentration of toxicant (detergent) and tine of exposine. The Docosahexaenoic acid (DHA) of the control fish maintained it's normal omega-3 fatty acid structure or appearance. in the tested fish, there was changes in the structure of the DHA in the fish oil. Detergent effluent is highly toxic to juvnile mackerel fish which are more susceptible to this household cleaning agent's effluent. Therefore an indiscriminate discharge of this effluent (Detergent) to the agnatic ecosystem should be discharged.