Abstract

Pesticide constitute one of the most important pollutants in the aquatic environment pesticide can find their way into food chain, hence the need to study the effect of glyphosate on Heterobranchus bidorsalis enzymes and electrolytes. Adult Heterobranchus bidorsalis (mean length 15.07±0.28cm, mean weight, 18.05±0.4g) were acclimatized individually in a rectangular aquaria for seven days and then exposed to varying concentrations of the toxicant in a static bioassay for 30 days. Alkaline aminotranferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were determined in the plasma and kidney while electrolyte (Ca+, K+, Na+) were determined in the liver. All the enzymes tested were statistically significant (p<0.05). Liver K+ values increased as the concentration of the toxicant increases (in a dose dependent pattern). While Ca2+and Na+ values were not statistically significant (P>0.05), rather a slight fluctuation in values within the experimental group were observed. It is concluded that glyphosate could be toxic at high concentration. Enzymes tested are more useful biomarker of sublethal effect of glyphosate than the electrolytes. Further studies are required to evaluate the toxicity of glyphosate in Heterobranchus bidorsalis fingerlings, juveniles and recovery response in adults.