Production Characteristics and Body Composition of Florida Pompano Reared to Market Size at Two Different Densities in Low-Salinity Recirculating Aquaculture Systems

The effect of culture density on production characteristics and body composition of Florida pompano Trachinotus carolinus reared to market size using recirculating aquaculture systems (RASs) maintained at a salinity of 5‰ was evaluated in a 110-d growth trial (water temperature = 27.0-28.5°C). Juvenile Florida pompano (mean weight ± SE = 259.0 ± 3.0 g) were stocked into two tanks from each of four separate RASs at an initial nominal density of 6.5 (low density) or 13.0 kg/m3 (high density), equivalent to 200 and 400 fish/tank, respectively. After stocking, fish were fed a 4.7-mm, floating pelleted diet (50% protein, 14% lipid) twice daily at a targeted daily feed rate of 3% body weight per day. At stocking and at 3-week intervals thereafter, 10% of the fish population of each tank was sampled to determine production characteristics, including mean weight, weight gain, specific growth rate, absolute growth rate (AGR), feed conversion efficiency (FCE), biomass, and survival. At termination, fish in all tanks were harvested to determine production characteristics and samples were obtained to determine whole-body composition, energy retention, protein efficiency ratio (PER), protein productive value (PPV), hepatosomatic index, gonadosomatic index, and fillet yield. Results indicated that final weight (570.0 g), weight gain (312.7 g), AGR (2.8 g/d), FCE (25.5%), PER (0.54), and PPV (11.5%) of fish reared at high density were significantly lower than those of fish reared at low density. No differences were observed between density treatments with respect to other measured variables. Additional studies must focus on the development of finishing diets for final stages of Florida pompano production to increase FCE and to determine optimal rearing densities. In addition, research to evaluate the potential of rearing pompano in RASs at salinities lower than 5 per thousand, perhaps through environmental or dietary enhancement of critical ions, is warranted.