Acute and chronic effects of organophosphate pesticides (Basudin) to amphibian tadpoles ( Ptychadena bibroni )

Abstract

Toxicity of basudin (an organophosphate pesticide) on the larval stages of the dominant amphibian; Ptychadena bibroni of the Niger Delta ecological zone of Nigeria was assessed using acute and chronic toxicity in the laboratory. Mortality and body glycogen levels were used as ecological endpoints. The American society of testing and material (ASTM) recommended semi-static renewal bioassay was employed and LC50 was measured at 96 h. The amphibian larval stages were exposed to basudin concentrations of 0.1, 1.0, 10.0 and 25 ug/l. Derived 96 h LC50 values decreased with increased exposure duration. Estimated 96 h LC50 was 0.860 ug/l. Substantial mortality and incidence of abnormal avoidance response occurred more at higher concentrations. Body glycogen levels in all test concentrations were significantly different between the test and the control experiments at P<0.05. The decrease in glycogen level varied negatively with mortality, exposure duration and concentrations. The amphibian assay described in this study can be used to assess the toxicity of basudin pesticides in the course of regulatory surveillance and monitoring of the waters of the Niger Delta ecological zones of Nigeria.