Side-effects of a neonicotinoid insecticide (actara®) on a non-target larvivorous fish Gambusia affinis: Growth and biomarker responses

Abstract

Actara® 25 WG belongs to neonicotinoids, which is the most widely used insecticide class for controlling various insect pests in the world. The present study was aimed to assess the potential hazards of this insecticide on the mosquitofish Gambusia affinis following a chronic exposure. The female adults were collected during the reproduction period and exposed to various concentrations (10, 20 and 40 mg.L−1) during 28 days. The effect of actara was investigated on morphometric and selected biomarker measurements. Results showed that the compound was found to affect significantly the condition factor at days 21 and 28 of exposure with the highest concentration. However, the treatment had no effect on hepato-somatic and gonado-somatic indices. Biochemical analyses revealed an increase in glutathione S-transferase activity and carbonylated protein content, and a decrease in acetylcholinesterase activity for the three tested concentrations while the vitellin level was reduced only for the highest concentration. Thus, this product can pose side-effects on this non-target freshwater fish.

Keywords

• Toxicity
• Actara
• Fish
• Gambusia affinis
• Metric indices
• Biomarkers