Growth Response and Feed Utilization in the Cichlid, Tilapia zilli Exposed to Sublethal Concentrations of Linear Alkylbenzene Sulphonate (LAS) Detergent

Abstract

Fingerlings of the cichlid Tilapia zilli, were exposed to various sublethal concentrations of linear alkylbenzene sulphonate (LAS) detergent, a toxicant, and the effects on growth response indices and feed utilization were recorded using biostatic assays. Water quality was also monitored. The fish were exposed in aerated tanks for 12 weeks, at concentrations of 1.56, 0.39, 0.196, 0.098 and 0.00 (control) mgL-1. No mortality occurred in the exposed fish or in the control group. The toxicant led to significant depression in weight gain in direct proportion to concentrations of the toxicant. Feed utilization was significantly reduced. The environmental impacts on fish of detergents in an ecosystem are discussed.