Impact of feeding pikeperch Sander lucioperca (L.) feeds of different particle size on the results of the initial on-growing phase in recirculation systems

Two experiments were performed to analyze the impact of applying two formulated feeds of different particle sizes (feed 1 - particle length - 2.8 mm; feed 2 - 4.5 mm) on the results of on-growing pikeperch in recirculating aquaculture systems (RAS). Two pikeperch size classes were used: in experiment I the mean body weights (BW) were 74 and 102 g, and in experiment II the BW were 125 and 170 g. The fish in both size groups in experiment I that were fed feed 1 achieved significantly quicker growth and better values of the feed conversion ratio (FCR) values (P < 0.05). Larger intragroup differences in final BW and condition coefficients were noted in the fish groups receiving feed 2. No significant differences in growth, condition, or FCR values were noted in either of the two pikeperch size groups fed experimental feed in experiment II. Pikeperch prefers feed of smaller particle size. In the initial on-growing phase, and particularly for fish of BW 70-125 g, it is recommended to use feed with the smallest particle size.