Effect of Ethoxyquin on Oxygen Consumption in Fresh Water Fish, Oreochromis mossambicus

Abstract

Being a powerful antioxidant, ethoxyquin (EQ-1,2-dihydro-6-ethoxy-2,2,4-trimethylquinoline) is employed in many different foods and animal feeds. Recent studies on animals on EQ diets have shown a broad range of unintended consequences. The negative effects of EQ on vertebrates are becoming well documented, while accounts of the effects of EQ on aquatic ecosystems are very rare. In this study, the LC50 96-hour value of EQ was determined in the freshwater fish Oreochromis mossambicus (Tilapia) using the Probit analysis. Throughout the course of 24 hours, 48 hours, 72 hours, 96 hours, 5 days, 10 days, and 15 days, the fishes were exposed to sub lethal concentration of the toxin. The quantity of oxygen used by Oreochromis mossambicus and the dissolved oxygen (DO) level in the water were both monitored during the length of the exposure. The bioassay found that the median lethal dosage in fish after 96 hours (LC50-96h) was 11.37 mg/L. A higher metabolic rate and, thus, a bigger amount of energy generated correspond to a lower oxygen intake rate in the experimental fish