Stocking Density Effects on Production Characteristics and Body Composition of Market Size Cobia, Rachycentron canadum, Reared in Recirculating Aquaculture Systems

Abstract Culture density in excess of a critical threshold can result in a negative relationship between stocking density and fish production. This study was conducted to evaluate production characteristics of juvenile cobia, Rachycentron canadum , reared to market size in production‐scale recirculating aquaculture systems ( RAS ) at three different densities. Cobia (322 ± 69 g initial weight) were reared for 119 d at densities to attain a final in‐tank biomass of 10, 20, or 30 kg/m 3 . The specific objective was to determine the effects of in‐tank crowding resulting from higher biomass per unit rearing volume independent of system loading rates. Survival was ≥96% among all treatments. Mean final weight ranged from 2.13 to 2.15 kg with feed conversion efficiencies of 65–66%. No significant differences were detected in growth rate, survival, feed efficiency, or body composition. This study demonstrates that cobia can be reared to >2 kg final weight at densities ≤30 kg/m 3 under suitable environmental conditions without detrimental effects on production.