Eggshell composition of Amazon turtle (Podocnemis expansa) is altered after incubation in substrates containing glyphosate and fipronil formulations

Besides its crucial role during embryo development, eggshells are an essential bioindicator of environmental contam-inants. However, the effects of contaminant exposure during incubation on the eggshell composition remain poorly known for freshwater turtles. Accordingly, we tested the effects of incubating the eggs of Podocnemis expansa in sub-strates containing glyphosate and fipronil formulations on the eggshell's level of mineral and dry matter, crude protein, nitrogen, and ethereal extract. Eggs were incubated in sand moistened with water contaminated with glyphosate Atar 48 at concentrations of 65 or 6500 & mu;g/L, fipronil Regent 800 WG at concentrations of 4 or 400 & mu;g/L, or the combina-tion of 65 & mu;g/L glyphosate and 4 & mu;g/L fipronil and 6500 & mu;g/L glyphosate with 400 & mu;g/L fipronil. Exposure to the tested pesticides, alone or in association, altered the chemical composition of the eggshell of P. expansa, reducing the egg-shell's moisture and crude protein content and increasing levels of ethereal extract. These changes may cause signifi-cant deficiencies in the mobilization of water and nutrients to the embryo, affecting the development and reproductive success of P. expansa.

Automated summary

In addition to its role in embryo development, the eggshell is a crucial bioindicator of environmental contaminants. However, the effects of contaminant exposure during incubation on the eggshell composition of freshwater turtles have been poorly understood. This study found that exposure to glyphosate and fipronil formulations during incubation altered the chemical composition of the eggshell of Podocnemis expansa, causing reductions in moisture and crude protein content and an increase in ethereal extract levels. These changes may have significant implications for the development and reproductive success of P. expansa.