Impact of higher stocking density of juvenile Atlantic sturgeon, Acipenser oxyrinchus Mitchill, on fish growth, oxygen consumption, and ammonia excretion

Abstract

The impact of stocking density on the growth, feed conversion, oxygen consumption, and ammonia excretion of juvenile Atlantic sturgeon (Acipenser oxyrinchus Mitchill) was studied. Three initial stocking densities were used in the experiment: 1.27, 2.49, and 3.80 kg m -2 . The length of the experiment was 64 days. The mean water temperature was 15.0C. The fish were fed commercial feed Nutra T 1.9 (Trouv, France). Atlantic sturgeon body weight growth was the highest in the group stocked at the lowest density. The fish from this group attained a final body weight of 130.1 g, which was statistically significantly higher than that of the groups stocked at densities of 2.49 kg m -2 (P 0.01). Stocking density had a substantial impact on the value of the feed conversion ratio (FCR) in the different groups. The lowest FCR was noted at the density of 1.27 kg m -2 at 0.67. This value differed statistically significantly from group 2.49 kg m -2 ,i n which it was 0.74 (P < 0.05), and it differed highly statistically significantly from group 3.80 kg m -2 at 0.83 (P < 0.001). The differences in the FCR value between groups 2.49 and 3.80 kg m -2 were also highly statistically significant. Stocking density was not noted to impact oxygen consumption or ammonia excretion. Mean daily ammonia excretion fluctuated from 2.09 to 2.39 mg kg -1 h -1 , and oxygen consumption ranged from 90.5 to 93.8 mg O2 kg -1 h -1 .