The possibility of using sturgeon as a stock component during the rearing of pike (Esox lucius L.) fry in tanks was determined. The experiment was conducted in two stages. In the first, pike fry with a body weight of 0.1 g were reared in monoculture and polyculture with a sturgeon component comprising 40 and 80% of the pike biomass. In the second phase, pike fry weighing an average of 3 g were reared in monoculture and polyculture with a sturgeon component comprising 10 and 20% of the pike biomass. The introduction of the sturgeon improved feed utilization and lowered feed conversion ratios from 1.4 to 0.8 in the older pike group (statistically significant difference at P < 0.05). In experiment stage II, the pike fry reared in polyculture with sturgeon attained statistically significant (P < 0.05) higher body growth in comparison with the monoculture variant. Pike survival was the lowest in the monoculture at 72.1 and 91.4% in stages I and II of the experiment, respectively. With regard to the smaller fry, this was due primarily to cannibalism with such losses comprising over 50% of the total losses throughout rearing. Survival in the polycultures was as much as 12% higher. The authors believe that the possibility of rearing these two species together stems from their different behavior and feeding strategy. Another benefit was that the labor-intensive removal of feed not consumed by the pike fry was lowered which meant that there was minimal interference in the tank during rearing.