Polyculture of juvenile pikeperch (Sander lucioperca (L.)) and sterlet (Acipenser ruthenus L.) in a recirculating system

The experiment examined the possibility of rearing juvenile pikeperch, Sander lucioperca (L.) in polyculture with sterlet Acipenser ruthenus L. in a recirculating system. Three variants of pikeperch rearing were tested: monoculture (group S), with the addition of sterlet at 10% (group S10) and 20% (group S20) of the initial pikeperch biomass. After 56 days of rearing, no differences in the growth rates or survival of the pikeperch were noted. The value of the feed conversion ratio in the monoculture group was 1.19 and was significantly statistically higher than in the polyculture groups, the values of which were 0.84 (S10) and 0.74 (S20). The mean oxygen consumption and ammonia excretion values did not differ significantly statistically among the studied groups. Including the sterlet stock with the pikeperch permitted obtaining the additional value of the sterlet biomass using the same quantity of feed. Additionally, the inclusion of sterlet decreased the labor intensity of pikeperch rearing since the tanks did not need cleaning as frequently.