An evaluation of stocking density in the cage culture efficiency of Amur sturgeon Acipenser schrenckii

Abstract

Summary The effects of stocking density (15, 30, 45, and 60 fish m−2) on the production economics, growth, food utilization, and body composition of Amur sturgeon reared in cages were investigated. The weight of the fish at the start of trial was 48.7–51.6 g. After 75 days of rearing, the mean weights were 110.3 ± 11.2, 90.3 ± 10.2, 79.9 ± 8.5, 78.7 ± 7.2 g in the aforementioned densities, respectively. The results show that the growth performances in the various treatments differed significantly (P < 0.05) in terms of final weight and condition factor. The feed conversion rate of 15 fish m−2 treatment was highest at 1.41, compared with 2.04, 2.08, and 3.13 in other densities. Body protein and fat decreased with the increasing density, while moisture increased (P < 0.05). Final biomasses were 32.3, 49.2, 67.3, and 76.9 kg per cage (cage size: 4 × 5 × 3 m), and benefit-cost ratios were 0.39, 0.22, 0.19, and 0.06, respectively. These results indicate that cage farming of Amur sturgeon stocked at a lower density (15 fish m−2) did not achieve higher production, but production economics revealed that it provided the highest benefit-cost ratio.