Large-scale phenotyping in a wild rhabditid nematode and C. elegans reveals differential neurobehavioral responses to a nanoscale pollutant and temperature

Environmental factors shape organismal health through complex interactions collectively referred to as the exposome. Yet, the interplay between chemical and non-chemical exposome factors remains poorly understood. Here, a dopaminergic reporter strain of Caenorhabditis elegans and a field isolated rhabditid nematode were used in a behavioral arena to assess natural variation in locomotory behavior in response to silica nanoparticles as a chemical exposome factor, and ambient temperature conditions (15 °C, 20 °C, and 25 °C) as non-chemical factors. Our results reveal that in the C. elegans reporter strain lower temperature (15 °C) mitigates silica-induced locomotion deficits, while higher temperature (25 °C) exacerbates neurotoxicity, suggesting a temperature-dependent response. Notably, the wild rhabditid isolate showed distinct behavioral responses compared to the laboratory strain, highlighting the importance of species-specific ecological backgrounds in toxicological studies. By generating a phenotype–exposome map from large-scale quantitative behavioral studies, we extend the capacity to identify ecotoxicological hazards of nanomaterials across taxa.