Comparative toxicity and biochemical responses of certain pesticides to the mature earthworm <i>Aporrectodea caliginosa</i> under laboratory conditions

Abstract

This study was conducted to investigate the toxicity of aldicarb, cypermethrin, profenofos, chlorfluazuron, atrazine, and metalaxyl toward mature Aporrectodea caliginosa earthworms. The effects of the LC(25) values of these pesticides on the growth rate in relation to glucose, soluble protein, and activities of glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT), acid phosphatase (AcP), and alkaline phosphatase (AIP) were also studied. The results showed that aldicarb was the most toxic of the tested pesticides, followed in order by cypermethrin, profenofos, chlorfluazuron, atrazine, and metalaxyl. A reduction in growth rate was observed in all pesticide-treated worms, which was accompanied by a decrease in soluble protein and an increase in transaminases and phosphatases. Relationships between growth rate, protein content, transaminases, and phosphatases provided strong evidence for the involvement of pesticidal contamination in the biochemical changes in earthworms, which can be used as a bioindicator of soil contamination by pesticides.