Effects of starvation and re-feeding on compensatory growth performance, plasma metabolites and IGF-I gene expression of Persian sturgeon (Acipenser persicus, Borodin 1897)

The effects of starvation and subsequent re-feeding on compensatory growth performance, blood serum metabolites and IGF-ImRNA expression in liver and muscle were investigated in juvenile Persian sturgeon. Growth indices including body weight, SGR, CF, and HSI significantly decreased after starvation. However, after re-feeding sturgeons that were starved for 1 week reached the same weight as the control, indicating that complete compensatory growth had occurred. Conversely, sturgeon in longer periods of starvation showed only partial growth compensation. HSI values decreased significantly during starvation, although they returned to the control fish levels after re-feeding. Plasma levels of glucose and insulin during starvation and re-feeding did not significantly change. This suggests that sturgeon is able to maintain glycaemia during starvation, probably due to their non-carbohydrates source dietary. Plasma total lipid level in un-fed treatments, however, was found to increase, possibly as a mechanism to utilise lipids as a fuel during starvation. IGF-I mRNA expression in liver and muscle increased during starvation and decreased after re-feeding. However, changes in the IGF-ImRNA expression were not significantly different among treatments. These results indicate that a periodic short-term starvation in Persian sturgeon does not adversely sacrifice overall fish weight gain and sturgeon can realise compensatory growth