Author/Authors :
ZARE, R. khoramshahr marine science and technology university - Department of Fisheries, خرمشهر, ايران , BAHMANI, M. International Sturgeon Research Institute, ايران , YAVARI, V. khoramshahr marine science and technology university - Department of Fisheries, خرمشهر, ايران , KAZIMI, R. , PASHA, H. khoramshahr marine science and technology university - Department of Fisheries, خرمشهر, ايران , POURDEHGHANI, M. khoramshahr marine science and technology university - Department of Fisheries, خرمشهر, ايران , FAZELI, N. , YOONESZADE, B. , NATEGHI, S.A. khoramshahr marine science and technology university - Department of Fisheries, خرمشهر, ايران
Abstract :
Three year old Siberian sturgeons (Acipenser baerii) were reared at five densities in indoor fiber-glass tanks to evaluate the effects of stocking density on growth, survival, condition, and feed efficiency. Fish (mean weight, 460±90g) were stocked into 500-L fiber-glass tanks containing 270 liters of water at rates of 6, 9, 12, 15 and 18 fish per tank (3-9 kg/m²). The growth trial was conducted over an 8-week period during which the fish were offered a 45%-protein commercial ration in slight excess. At the termination of the study, the mean weights as well as the lengths and weights of individual fish in each tank were recorded. Biometry takes place every 20 days. The final weights of the fish decreased insignificantly as density increased (p 0.05), with fish stocked at a density of kg/m² having a mean weight of 746 g and those stocked at 9kg/m² having a mean weight of 7.3 g. The percentage of weight gain and feed efficiency also decreased as stocking density increased. No significant differences in GR, SGR, BWI and FCR were found among treatments (p 0.05). The end result shows that Siberian sturgeons seem to be able to tolerate high stocking densities and this species could be easily reared in fiber-glass tanks at the rate of 10 kg.m^-2.
