Impacts Of Diazepam On The Survival, Development, And Response To Light Stimulation In Early-Life Stages Of Zebrafish (Danio Rerio)

Environmental residues of diazepam (DZP) may pose potential risks to aquatic species, especially to fishes. This study exposed zebrafish embryos to DZP (0, 0.4, 4.0, 40, 400, 4000 mu g/L) until 120 hours post-fertilization (hpf) and examined their survival, development, hatching, and behavioral responses to light-dark transition. Exposure to DZP at 4000 mu g/L significantly reduced the survival of zebrafish, and the 96 h-LC50 for DZP was calculated as 3202.4 (3068.2-3555.6) mu g/L. Exposure to DZP at 4, 40, and 400 mu g/L could induce bradycardia in zebrafish embryos on 48 hpf and significantly delay their hatching time. Under the cycle of light-dark transition, zebrafish larvae (120 hpf) in all groups were more active in the dark period than the illumination period. However, exposure to DZP at >= 0.4 mu g/L could evoke an anti-anxiety effect in the illumination period and increase their sensitivity to the conversion of light and dark.