Exposure to Dimefluthrin Affects the Development of Zebrafish (Danio rerio)

Dimefluthrin is a widely used insecticide that exhibits toxicity to numerous aquatic organisms. However, its developmental effects on fish remain poorly understood. This study investigated the impact of dimefluthrin exposure on zebrafish (Danio rerio) development. Embryos were exposed to 0.2, 0.6, and 0.8 µM dimefluthrin for 96 h post-fertilization (hpf). Morphological alterations, oxidative stress levels, and the transcription of embryogenesis-related marker genes were assessed. Dimefluthrin exposure induced significant locomotor impairments, characterized by intensified spastic movements and altered swimming trajectories in larvae. Swim bladder formation was inhibited, leading to non-inflated swim bladders. Notably, dimefluthrin exposure resulted in a 43.33% increase in superoxide dismutase (SOD) enzymatic activity and an 82.25% decrease in malondialdehyde (MDA) content compared to controls. Furthermore, dimefluthrin disrupted the expression of dopamine-related genes (th and slc6a3) and swim bladder marker genes (anxa5b and hprt1l). These findings demonstrated that dimefluthrin induces locomotor dysfunction, oxidative stress, and swim bladder non-inflation in zebrafish, providing valuable insights into its potential environmental risk assessment.