Functional responses of tadpoles exposed to different concentrations of Roundup® herbicide

Habitat loss and degradation are among the primary drivers of global biodiversity decline, mainly driven by agricultural expansion (leading to habitat loss) and the widespread use of pesticides (causing habitat degradation). Pesticides affect both aquatic and terrestrial organisms, as they run off from application sites into water bodies, reaching multiple ecosystems and species. Here, we evaluated the effects of Roundup®, a pesticide based on a Glyphosate and Polyoxyethyleneamine formula, on the functional morphological traits of Boana faber (Blacksmith Treefrog). Through a controlled laboratory experiment, we exposed 51 tadpoles to varying concentrations of Roundup® and analyzed 11 morphological characters associated with four critical functional traits: feeding, locomotion, gas exchange, and sensory perception. Our findings reveal that Roundup® exposure significantly alters tadpole functional morphology. Traits associated with locomotion and sensory perception exhibited the most substantial disruptions. Higher Roundup® concentrations reduced the functional space occupied by locomotor traits, suggesting decreased morphological plasticity and potentially compromised habitat exploration ability. Conversely, sensory traits exhibited expanded functional space, possibly reflecting compensatory plasticity or dysregulated phenotypic development induced by chemical stress. These shifts indicate potential impairments in foraging efficiency, predator evasion, and overall ecological performance. Given that the maximum Roundup® concentration used in this study (520 µg/L) mirrors levels found in Brazilian water bodies, the implications for wild populations are concerning. These findings underscore the urgent need for sustainable agricultural practices to mitigate the cascading effects of pesticide use on aquatic ecosystems.