Effects of sublethal concentrations of isoxaben on the development of the African clawed frog, Xenopus laevis

Abstract

Agricultural pesticide exposure is one factor implicated in the decline of amphibian abundance in aquatic ecosystems. Isoxaben is a cellulose biosynthesis inhibitor mainly used for roadside weed control, suggesting that isoxaben can run off during rain events and potentially affect amphibian development. This study followed the development of African clawed frog (Xenopus laevis) tadpoles exposed to different environmentally relevant concentrations of isoxaben. No significant adverse effects were observed on days to metamorphosis or size and weight at metamorphosis. This reinforces the conclusion that isoxaben herbicide application at low environmental concentrations is not a substantial risk to wildlife.

Keywords:

• isoxaben
• development
• amphibian
• Xenopus

Acknowledgments

The authors thank Karen Brown Sullivan, Christopher Rogers, Courtney Roths, and the staff of North High School. This work was supported by grant no. 0537844 from the National Science Foundation Graduate STEM Fellows in K-12 Education program.