Rearing performance of juvenile yellowtail snapper, Ocyurus chrysurus, in a sea water recirculation system at two different stocking densities

Abstract

Evaluation of viability of new marine species in aquaculture systems is important to reduce negative social and environmental externalities, offering sustainable options for supply to fish markets. The objective was to describe the performance indicators of late juvenile yellowtail snapper (243.2 ± 57.1 mean weight of total fish) in an experimental recirculating aquaculture system (RAS) system supplied by seawater to determine its pre-feasibility. Two densities were stocked, D₁: 10 fish/tank (2.6 kg/m³, mean weight 258.3 ± 57 g) and D₂: 20 fish/tank (4.7 kg/m³, mean weight 235.6 ± 55.9 g). Fish were fed to satiety with an extruded diet containing 46% crude protein and 12% crude lipid. After 238 days, survival rate was 93% for both densities, and mean weight and biomass were 534.5 ± 19.4 g and 5.7 kg/m³ for D₁, and 606.9 ± 34.5 g and 10 kg/m³ for D₂. Final feed conversion rate (3.13 for D₁ and 3.03 for D₂) did not differ significantly between densities. The exponents (b) of the length–weight relationship calculated for D₁ (3.15) versus D₂ (3.10) and condition factor (2.12 ± 0.07 for D₁, and 2.03 ± 0.04 for D₂) demonstrated a higher condition factor than those of their wild counterparts. This study is one of the few reports on this species’ performance in late juvenile stage in RAS.