Influence of stocking densities and aeration systems on Nile tilapia (<em>Oreochromis niloticus</em>, 1757)

Abstract

A 252-day experiment was carried out in nine fish ponds with male sex-reversed Nile tilapia with 16.3g average weight and fed on commercial ration (29.5% crude protein). The efficiency of aeration systems (A₁=non-aeration control; A₂=radial compressor and A₃=sprinkler) was compared in three stocking densities (D₁=3 fish/m³; D₂=6 fish/m³ and D₃=9 fish/m³), through the evaluation on their final weight (FW), carcass weight (CW), fillet weight (FIW), skin weight (SWO), visceral fat weight (VFW), carcass yield (CY) and fillet yield (FIY). Plotting was completely randomized through a 3x3 factorial scheme, with 30 replications, and each fish was considered as an experimental unit. The heaviest FW (530.27g) and CW (431.22g) were obtained in D₁. The radial compressor system was significantly more efficient than the other systems for FW and CW; as for FIW it was only slightly significantly more efficient in D₂ (162.67g). The heaviest VFW (37.36g) and SW (38.13g) were observed in D₁, with A₂ and A₃ respectively. There was no significant difference for CY between the densities, and A₃ provided the highest results. FIY varied from 31.73% (A₂D₁) to 37.14% (A₁D₁) in the treatments.