Review of Ecological Significances and Roles of Aquatic Macrophytes

Abstract

Abstract
A study was carried out to evaluate the toxicity of two pyrethroid insecticides on O.niloticus juveniles. Cyperforce and kilsect were used in the study. Acute toxicity was determined using the (OECD, 1992) 96hr static method of toxicity testing. Concentrations used are 0.5, 1.0, 1.5, 2.0 and 2.5µg/L. The experiments were repeated 3 times for each concentration with a blank serving as a control. Bioassay results (96hr) showed that both the two pyrethroids are toxic. Data obtained was evaluated using probit analysis method and the LC50 at (p<0.05) was 1.63 and 0.58 µg/L for cyperforce and kilsect respectively. It can be concluded that the pyrethroid insecticides used (cyperforce and kilsect) were toxic to O.niloticus juveniles though there is a significant difference between the toxicity of the two with kilsect showing more toxicity.