INFLUENCE OF STOCKING DENSITY AND WATER PARAMETERS ON GROWTH OF JUVENILE BELUGA STURGEON (HUSO HUSO, LINNAEUS, 1758)
I. Vasilean, V. Cristea, Lorena Sfetcu
The main purpose of the present experiment consist in evaluation of growth performances of beluga sturgeon juveniles (obtained from the artificial reproduction of mature sturgeons with origins in the Danube-Pontic basin) reared in different stocking densities in a recirculating aquaculture system. The influence of stocking density and water quality on the growth of beluga fingerlings was studied during 30 days. The two experimental variants (V1 and V2) were formed by two rearing units each with a different fish density: 30 exemplars (initial average weight -34g) in first two aquaria (V1) and 10 exemplars (initial average weight -25g) in the following two aquaria (V2). The fish were fed a 55% protein feed to a feeding rate of 3 % body weight/day. During experiment water quality parameters (pH, O2, T, NH3-N, NO2-N, NO3-N) were recorded an a daily basis and, every 2 weeks, the fish were weight individually, and weight gain was recorded. Beluga growth performances were evaluated through analysis of various technological indicators: W (weight gain), FCR (food conversion ratio), SGR (specific growth rate), PER (protein efficiency ratio). The body profile was evaluated through allometric factor.
Key words: recirculating system, sturgeons, artificial feed