The effect of Fish Phos mineral supplement on the growth and nutritional indices of juvenile Sterlet sturgeon (Acipenser ruthenus)

In this study, the effect of different levels of Fish Phos soluble mineral supplement (0, 2, 4 and 8 ml/kg diet) on the growth and nutritional performance of juvenile Sterlet sturgeon (Acipenser ruthenus) was investigated. For this purpose, a total number of 360 fish with 17.1 ± 0.2 g initial weight (mean ± SD) and 17.3 ± 0.1 cm total length were randomly assigned to 12 circular concrete tanks (1.85 m diameter and 0.25 m depth). The fish distributed in 4 treatments with 3 replicates (30 fish per tank) and fed for 8 weeks. The results of growth and nutritional indices showed that the highest amount of feed conversion ratio and voluntary feed intake was observed in the fish fed with 8 ml/kg mineral supplement, which had a significant difference with the control and other treatments (p<0.05). The highest survival rate was observed in the control treatment and 2 ml/kg diet, and with an increase in the dose of the supplement, the survival rate decreased (p<0.05). In other parameters including final weight, weight gain, body weight increase, specific growth rate, average daily growth, condition factor and feed intake no differences were observed (p>0.05). The present study showed that this mineral mixture could not have a positive effect on the growth and nutritional indices of juvenile Sterlet sturgeon in the studied weight range, and with increasing dosage, the survival rate was also decreased. Therefore, using this supplement in lower doses and for a longer period with a more complete combination of other elements can be recommended.