The target of this novel work is to assess the immunosuppression, genotoxicity, histopathological alterations, and cumulative mortality induced by acute toxicity of magnetite nanogel (MNG) in Nile catfish. Furthermore, a subsequent 10-day depuration period is adopted to estimate the restoration of those disturbed indices. Nile catfish (n = 180) were allotted into four groups and exposed to different concentrations of MNG (0, 1/10, 1/8, and 1/5 96-h LC