Toxicity of dimethylformamide at different developmental stages of Biomphalaria glabrata: Lethal concentration determination and longitudinal assessment of physiological changes

Dimethylformamide (DMF) is a widely used polar organic solvent with potential hepatotoxicity and environmental release risks. DMF, as an important industrial solvent, poses a high risk of environmental leakage, particularly in aquatic environments, where it may have toxic effects on aquatic organisms, particularly gastropods. Gastropods are an important component of aquatic ecosystems, yet no studies have focused on the toxic effects of DMF on this group. In this study, the freshwater gastropod Biomphalaria glabrata was employed as a model organism to evaluate both the acute and chronic toxicity of DMF at embryonic, newly hatched, and adult stages. We hypothesized that DMF would exert stage-specific, concentration-dependent toxic effects on multiple biological functions, including survival, growth, reproduction, immune responses, and tissue structure. Static exposure experiments revealed LC₅₀ values of 0.46 % (216 h), 0.58 % (96 h), and 1.67 % (96 h) for embryos, newly hatched juveniles, and adults, respectively. Chronic exposure over 21 days showed that DMF significantly inhibited shell growth, body weight gain, and oviposition in a concentration-dependent manner. Hematological assessments demonstrated that hemolymph volume, cell density and viability declined progressively with increasing DMF concentrations, suggesting immunosuppressive effects. Histopathological analysis further revealed progressive structural damage in both the hepatopancreas and gonadal tissues. This study provides a comprehensive characterization of DMF toxicity across different developmental stages of B. glabrata, demonstrating its adverse effects on survival, growth, reproduction, immune function, and tissue structure. The results extend current understanding of polar organic solvent toxicity in aquatic invertebrates and offer a solid experimental basis for further research in environmental and immunotoxicology.