The current studies aimed to determine the dietary arginine (Arg) requirement for fingerling Florida pompano (Trachinotus carolinus). In Trial 1, eight isonitrogenous (40% crude protein) and isolipidic (8% crude lipid) diets were formulated with varying levels of L-arginine supplementation (0, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.65%), resulting in dietary Arg concentrations that ranged of 2.32 – 2.94% of dry diet (5.66 to 6.95% of dietary protein). Five replicate groups of 12 juvenile pompano (initial weight: 11 ± 0.27g) were fed these experimental diets for 12 weeks. Growth performance parameters, including final weight (53.06–59.96g), percent weight gain (381.05 – 442.26%), feed conversion ratio (1.64 – 1.80), thermal growth coefficient (0.58 – 0.68), survival rate (96.67 – 100%), and apparent net protein retention (24.48 – 26.79%), showed no significant differences among treatments (P > 0.05). Similarly, whole-body proximate composition, amino acid profiles, and serum biochemical parameters remained unaffected by different dietary Arg levels. These results suggest that the Arg requirement of juvenile Florida pompano is lower than the basal diet (2.32% Arg). Consequently, Trial 2 was initiated with a modified diet containing lower Arg levels (4.44 – 6.56% of dietary protein) to determine the requirement threshold more accurately. Trial 2 is currently in progress and will assess growth performance, whole-body composition, blood biochemistry, and immune response. After the trial ends, data from both trials will be analyzed using nonlinear models to identify the optimal dietary Arg level for juvenile Florida pompano. These results will provide crucial insights into developing cost-effective, nutritionally balanced feeds for this economically important marine species.