Document Type : Research Paper
Authors
1
1. Fisheries Department, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, Iran. Email: falahatkar@guilan.ac.ir
2
Dr. Yousefpour National Center for Stock Enhancement and Conservation of Caspian Sea Sturgeons and Perch Genetic Resources, Siahkal
10.22059/jfisheries.2026.108951
Abstract
This study was conducted to investigate the effects of two key management factors, namely stocking density and feeding frequency, on juvenile farmed beluga sturgeon (Huso huso) over an 8‑week period. For this purpose, four treatments were designated, each with three replicates: low density with 2 feeding frequencies per day, low density with 3 feeding frequencies per day, high density with 2 feeding frequencies per day, and high density with 3 feeding frequencies per day. In the low‑density treatments, 10 fish (mean weight: 120.3 ± 23.2 g) were stocked per circular concrete tank (approximate volume: 800 L), whereas in the high‑density treatments, 20 fish of the same initial weight were introduced per tank. Throughout the rearing period, weight gain was significantly higher in the low‑density groups compared with the high‑density groups, irrespective of feeding frequency (P < 0.05). However, total length did not differ significantly among treatments (P > 0.05). Moreover, other growth indices, including weight gain, body weight increase, specific growth rate, and daily growth rate, were significantly greater in the low‑density treatments than in the high‑density treatments (P < 0.05). Survival rate exceeded 96% across all treatments, with no significant differences among groups (P > 0.05). Regarding nutritional indices, including feed intake per fish, feed conversion ratio, and voluntary feed intake, no significant differences were observed among the treatments (P > 0.05). The results of this study indicate that stocking density, irrespective of feeding frequency, significantly influences growth performance, and that increasing feeding frequency cannot compensate for the adverse effects of high stocking density. Therefore, it appears that an optimal combination of stocking density and feeding frequency, tailored to each rearing stage, can positively enhance growth performance and improve nutritional conditions in farmed beluga sturgeon.
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