THE INFLUENCE OF STOKING DENSITY OF PIKEPERCH FRY REARED UNTIL 40 DAYS POST-HATCH IN CONTROLLED CONDITIONS ON THEIR GROWTH AND SURVIVABILITY

There are just few reports available related with the effect of stocking densities on the rearing of the pikeperch larvae and fry in the controlled conditions. The aim of this study is to identify the effect of stocking density on the growth performances of the pikeperch fry raised in recirculated aquaculture system (RAS) in the first 40 days post-hatch (DPH). Two variants of stocking densities were tested: 12 individuals lʹ1 and 9 individuals lʹ1. Growth dynamic of the pikeperch fry was monitorised by somatic measurements of randomly sampled individuals at each 7 days, until the age of 40 days post-hatch. Even at final the difference between total lengths of the individuals from the two variants was insignificant (p>0.05), very significand differences (p<0.001) were observed at their survivability. Therefore, a higher density (12 individuals lʹ1) donʹt negatively influence the growth dynamic, but have a significant effect on survivability ofpikeperch fry