Developmental Effects of the Pesticide Imidacloprid on Zebrafish Body Length and Mortality

Abstract

The pesticide imidacloprid, a Neonicotinoid, is widely used and commercially available. Neonicotinoids are antagonists at nicotinic acetylcholine receptors, which can cause neurobehavioral effects in developing organisms. While the effects of other insecticides such as Malathion and Fipronil on zebrafish Danio rerio development have been studied, few studies describe the morphological effects of imidacloprid during zebrafish development. To test the hypothesis that imidacloprid concentration positively correlates to increased mortality and decreased body length, we exposed zebrafish to imidacloprid for five days post fertilization. Body length and embryo mortality were recorded at 1, 2, 3, 4, and 5 days post fertilization in 0 ug/L, 100 ug/L, 1,000 ug/L, and 10,000 ug/L imidacloprid concentrations. These concentrations were chosen to mimic levels that could be reached in the environment especially soon after application. Our results demonstrate statistically increased embryo mortality, with a f crit value of 3.193 and a f value of 3.098 from an ANOVA test, and impaired body length with a dose dependent correlation to the concentration of imidacloprid and a P value of less than 0.01 from a T test. Given the pesticides high prevalence, future studies should be considered to determine if this effect may impact livestock and human development.