Biomarkers of Environmental Contamination in Reptile Species: The Effect of Pesticide Formulations on Broadsnouted Caiman Caiman latirostris (Crocodilia, Alligatoridae)

Abstract

Pesticide formulations are currently considered as one of the main factors responsible for environmental contamination worldwide. Consequently, several wild species can be affected by the overuse of pesticides and fertilizers in agricultural activities. In recent years, we have been evaluating the effects of different pesticide formulations (glyphosate-, endosulfan-, cypermethrin- and chlorpyrifos-based formulations) and mixtures widely used in Argentina and other neighboring countries on broad snouted caiman (Caiman latirostris) as a sentinel reptile species for pesticide contamination. During this period, several instances of evaluation have been conducted in embryos and hatchlings, under controlled and semi-natural conditions. We used biomarkers of genotoxicity (micronucleus, other nuclear abnormalities, and the Comet assay) and oxidative stress (oxidation of lipids and DNA, and activity of the antioxidant enzymes catalase and superoxide dismutase), previously adapted by our group to be applied on blood, in order to avoid damage to the animals, as well as growth. All pesticides tested as well as the complex mixtures induced genotoxicity and oxidative stress through several biomarkers of different endpoints, in independent studies, but under these conditions, no synergistic effects were observed for the mixtures. The final aim is to continue with the integral in situ evaluation of environmentally exposed wild populations.