Effect of bicultural rearing of pikeperch (Sander lucioperca) and Russian sturgeon (Acipenser gueldenstaedtii) on growth and fish condition parameters in RAS

This study investigated the intensive rearing of pikeperch (Sander lucioperca) and Russian sturgeon (Acipenser gueldenstaedtii) in a recirculating aquaculture system for 84 days, with five different stocking ratios (with P as a percentage of pikeperch): P100, P90, P80, P70, and P0. The growth parameters, fish condition parameters, and blood biochemistry were measured. The P70 group showed the highest final total length, standard length, and body weight of pikeperch (82.95 ± 18.92 g), while the lowest values were found in Groups P100 (63.46 ± 18.49 g) and P90 (68.63 ± 13.79 g). The sturgeon did not show significant differences, except for Group P90, which had the lowest body weight (86.10 ± 33.95 g). Survival rates were high for pikeperch (96.098.6%) and no mortality in the sturgeon was evident in all groups. The feed conversion ratio (FCR) for pikeperch was similar between Group P100 (0.88 ± 0.02) and the two bicultural groups P90 (0.80 ± 0.04) and P80 (0.69 ± 0.05). For the sturgeon in Group P0, had a comparable FCR (0.71 ± 0.13). The lowest FCR for sturgeon was observed in the bicultural group P70 (0.66 ± 0.03). Tissue-somatic indices, hepatosomatic index (HSI), and fat-somatic index (FSI), supported significant differences only for pikeperch, with the highest values for the P80 and P70 groups. This study of pikeperch and Russian sturgeon rearing in various stocking ratios for 84 days demonstrates optimal growth and health parameters in the P70 group for pikeperch, with overall high survival rates and minimal health variations in sturgeon, suggesting the effectiveness of a mixed species approach in recirculating aquaculture systems. •The bicultural system with a higher proportion of sturgeons promotes pikeperch growth and condition without negatively impacting sturgeon condition.•Pikeperch reared in monoculture shows more serious fin damage than pikeperch in bicultural systems, while cultured sturgeon exhibits minimal fin damage.•Plasma parameters related to nutrition and metabolic processes show comparable values between experimental fish and healthy reference groups.