Substitution of fish meal (FM) as a protein source in aquaculture diets is required to reduce cost and promote a sustainable industry. Potential protein sources include a range of traditional products from agricultural production such as plant or animal proteins. However, there are also a number of manufacturing coproducts, including bacterial dried fermented biomass (DFB,) for which there is an increased interest. Hence, the objective of this study was to evaluate DFB as a replacement for FM in practical diets for Florida pompano, Trachinotus carolinus. Four diets were prepared in which different levels of FM (15%, 10%, 5%, and 0% of the diet) were replaced with DFB (0%, 4.27%, 8.54%, and 12.82%) on an iso-nitrogenous and iso-lipidic basis, to contain 40% crude protein and 10% lipid. A 10-week growth trial was conducted in a recirculating system consisting of 12 indoor 1.0 m³ tanks, stocked with 20 juvenile pompano (mean initial weight 8.1 g) per tank. There were no significant differences in final weight (64.5 g−79.5 g), survival (81.7%–96.7%), percent weight gain (711.6%–879.0%), FCR (2.1–2.0), or thermal-unit growth coefficient (0.1013−0.1149), regardless of the levels of dietary FM or DFB tested. Based on these results, it is recommended that DFB can be included up to 12.8% in practical diets for Florida pompano without significantly reducing growth performance. The response to higher levels of DFB inclusion should be evaluated.

Current research is intended to develop cost-effective, plant-based diets for intensive production of Florida pompano (Trachinotus carolinus). Three growth trials were conducted with juvenile pompano over a 106- to 115-day period. The trials evaluated the systematic substitution on an equal protein basis of (1) menhaden fish meal, FM with soy protein concentrate (SPC), and (2) solvent extracted soybean meal (SBM) with SPC. This confirmed the reduction of FM and evaluated the possible nutrient restrictions of methionine (M) and phosphorus (P) in low FM, high SPC diets. There was no significant reduction in growth parameters when FM was reduced from 300 to 150 g/kg. There was a significant improvement in fish performance with increased SPC concentrations substituted for SBM in diets containing 150 g/kg of FM. All growth parameters indicated a favorable response for inclusion of SPC up to 240 g/kg. The addition of P and M did not significantly improve growth.