Study of the Heart Rate of the Freshwater Snail Pomacea canaliculata and Its Potential Use for Bioassays: The Case of Glyphosate

Abstract

The mollusk Pomacea canaliculata, also known as the golden apple snail, is a South Americanfreshwater snail that has invaded crops and wetlands around the world. The areas invaded by this snail and its natural habitat both overlap with agricultural regions where glyphosate is used as an herbicide in transgenic crops. While P. canaliculata demonstrates resilience to high glyphosate concentrations, limited information exists on the agrochemical’s impact on the snail’s physiological parameters. This study aims to enhance our understanding of neonatal snail heart rate and investigate whether ecologically relevant doses of glyphosate induce alterations in heart rate or behavioral variables. The findings reveal that a minimum duration of 15 s yields a representative estimation of the heart rate in P. canaliculata. Implementing block experimentaldesigns enhances the comparison of heart rate between treatments by controlling for differences in the average heart rate among different egg clutches. Furthermore, a positive correlation was observed between heartrate, food intake, and temperatures ranging from 20 to 30°C. No discernible changes in heart rate or water escape responses were detected in snails exposed to glyphosate concentrations ranging from 0.5 to 8 mg/L for a maximum of 18 days. This lack of response to glyphosate does not depend on whether the snails are fasting or intermittently fed. However, it is not ruled out that prolonged exposure to glyphosate or other chemicals with more pronounced biological effect may influence the heart rate of P. canaliculata.