SELECTED METABOLIC ASPECTS OF PIKE-PERCH, STIZOSTEDION LUCIOPERCA (L.) REARED IN A WATER RECIRCULATION SYSTEM
Zdzisław Zakęś*, Krystyna Demska-Zakęś**, Piotr Karczewski**, Andrzej Karpiński*
*The Stanisław Sakowicz Inland Fisheries Institute in Olsztyn
**University of Warmia and Mazury in Olsztyn
ABSTRACT. The aim of the present study was to evaluate the effect of fish size (BW 11.7 g in the PS group, and 28.1 g in the PL group), feeding (SDA effect), and starvation (4, 13, 19 or 26 days in the PS-S group, and 4 or 13 days in the PL-S group) on oxygen consumption (OC, mg O2 kg-1 h-1), and ammonia excretion (AE, mg TAN kg-1 h-1) of the juvenile pike-perch Stizostedion lucioperca (L.) reared in water recirculation systems. The fish were fed high-protein commercial trout pellets for 18 h d-1 at daily rates of 2.5% (PS) or 1.2% (PL) of stock biomass. The average OC and AE values of the fed pike-perch from the PS group were equal to 355.70 mg O2 kg-1 h-1 and 21.21 mg TAN kg-1 h-1, respectively, and were 35% (OC) and 62% (AE) higher than in the PL group (P < 0.05). The metabolic rate of the starved fish was also inversely related to fish size and showed significant differences (P < 0.05). The energetic value of SDA was 62.8 kJ kg fish-1 d-1 (7.3% of feed digestible energy content) in the PS group, and 31.6 kJ kg fish-1 d-1 (5.2% of digestible energy) in the PL group. The starvation period of four days was too short for OoC and AE stabilization. The values of both parameters stabilized in the second and third week of starvation.
Key words: STIZOSTEDION LUCIOPERCA, JUVENILES, OXYGEN CONSUMPTION, AMMONIA EXCRETION, SDA EFFECT, WATER RECIRCULATION SYSTEMS