Assessment of Lc50 of Ethoxyquin on Experimental Model, Oreochromis mossambicus and Impact of Sublethal Concentration of Ethoxyquin on Water Quality Parameters

Abstract

Ethoxyquin (EQ) is a synthetic antioxidant that is included in some animal and human foods as a preservative to protect fats and fat-soluble vitamins from oxidative degradation. Many unfavourable side-effects have been observed in animals fed with EQ-containing feeds. Studies on the detrimental effects of EQ on vertebrates are growing, but the effects of EQ in aquatic systems have rarely been described. In the present study LC₅₀ 96 hr value of EQ to the freshwater fish Oreochromis mossambicus (Thilapia) was determined through Probit analysis. The fish maintained in freshwater behaved normal as usual. But when the fish was exposed to EQ, erratic swimming, abnormal posture, dis-balance, sluggishness, imbalance in posture, increase in surface activity, opercular movement, gradual loss of equilibrium and spreading of excess of mucus all over the surface of the body were observed. The water quality parameters were also changed drastically after EQ toxicity induction. The results revealed that a lower concentration of EQ is found to be highly toxic to fishes.