This study investigated the impacts of dietary supplements with ajwain seed extract (ASE) on the growth, biochem. parameters, digestive enzymes, antioxidant activity, immunity, and intestine histol. of Liza ramada.Juveniles (N = 450) with an initial weight of 40.12 ± 0.14 g were fed six exptl. diets enriched with ASE at 0 (control), 0.2, 0.4, 0.6, 0.8, and 1.0 g/kg diet for 60 days.Results revealed that fish-fed diets containing ASE at levels of 0.6 g/kg or higher exhibited significantly improved growth parameters including final weight, weight gain percentage, and specific growth rate, along with enhanced feed conversion efficiency compared to lower ASE levels and the control diet.Survival rates remained similar across all exptl. groups.Digestive enzyme activity, particularly lipase, was highest in groups fed higher ASE levels (≥ 0.4 g/kg diet).Histomorphol. anal. of the intestine showed improved villi structures with increasing ASE supplementation, reaching an optimal appearance at 0.8 g/kg.Blood biochem. anal. indicated higher total protein and globulin concentrations, and lower total cholesterol levels in groups with higher ASE intake (≥ 0.4 g/kg diet).Immune parameters increased with increasing ASE concentrations, including lysozyme activity, bactericidal percentage, and nitroblue tetrazolium levels.Antioxidant status, measured through superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels, showed significant improvements with ASE supplementation, with optimal dietary ASE levels for maximizing SOD (0.73 g/kg), CAT (0.74 g/kg), GPx (0.83 g/kg), and minimizing MDA (0.73 g/kg) identified through polynomial regression anal.These findings suggest that ASE supplementation (0.6-0.8 g/kg) pos. influences the growth performance, digestive function, gut health, immunity, and antioxidant status of L. ramada, highlighting its potential as a beneficial dietary additive in aquaculture.