Efficient feeding management is a key component in aquaculture, particularly under suboptimal environmental conditions, where maximizing growth performance and maintaining physiological homeostasis are essential for sustainable production. This study investigated the impact of different feeding regimes followed by a re-feeding phase on compensatory growth, hematological indices, and biochemical responses in different size of juvenile Siberian sturgeon (Acipenser baerii). For this purpose, fish experienced an initial 45-day feeding period under six groups: large-sized fish fed to satiation (LA), large-sized fish receiving 50% of satiation (LR), large-sized starved fish (LS), small-sized fish fed to satiation (SA), small-sized fish with 50% satiation (SR), and small-sized starved fish (SS) followed by 45 days of re-feeding to satiation for all groups. Initial mean weights were 465.75 ± 11.18 g and 250.40 ± 12.00 g for large and small size fish, respectively. Growth performance was assessed at the end of the experiment, and blood samples were collected for hematological and biochemical analyses. Results revealed that small fish subjected to starvation exhibited the lowest growth parameters after re-feeding, indicating persistent detrimental effects of early feed deprivation. No significant differences in growth were observed between restricted and satiated groups within the size classes. Most hematological parameters remained stable across treatments after re-feeding, except for white blood cell counts, which significantly varied; the highest values were recorded in LS and SA groups. Additionally, fish in the SS group showed markedly elevated glucose and cholesterol concentrations compared to other treatments. Albumin levels were significantly higher in the SS group compared with LS. These findings indicate that fish in restricted feeding in both size achieved compensatory growth while maintaining physiological homeostasis. Conversely, prolonged starvation impairs growth and alters biochemical profiles particularly in small size class. This feeding strategy may offer a cost-effective approach to optimize growth performance under challenging environmental conditions.
 

Aquaculture management, Acipenserid, Compensatory growth, size, starvation