Effect of temperature and feeding frequency on growth performances, feed efficiency and body composition of pikeperch juveniles ( Sander lucioperca)

Abstract

Pikeperch, Sander lucioperca, is a promising candidate for inland aquaculture diversification. Few studies have investigated the effects of temperature on growth despite it is the main determining factor in fish. Temperature namely acts on metabolism and thus influences feed intake. The aim of this study was to investigate the interactive effects of temperature and feeding on pikeperch growth. Eighteen groups of 21 fish (6.4 g mean weight) were reared in 18 tanks during 56 days according to a complete design testing 3 temperatures (20, 24 or 28 °C) and 3 feeding frequencies (1, 3 or 6 times a day to apparent satiation) in duplicate. Feed intake (FI) was recorded throughout the experiment. At the end of the study, fish were weighted for calculation of weight gain (WG), specific growth rate (SGR) and feed efficiency (FE). Total carcass protein and lipid content were determined. Protein and lipid retention efficiencies (PRE and LRE) were calculated. Based on the results, an optimal feeding rate was estimated for each rearing temperature. Temperature and feeding frequency had an interactive effect on WG and independently influenced SGR, FI and FE ( P < 0.05). WG, SGR and FE were the highest at 28 °C and/or when fish were fed 3 times a day (14.4 ± 0.4 g, 1.7–2.0 ± 0.04% and 0.95–0.97 ± 0.03% respectively). FI was the highest at 28 °C (13.1 ± 0.16 g) or when fish were fed 6 times a day (13.5 ± 0.16 g). PRE and LRE were significantly affected by feeding frequency only ( P < 0.05). They were lower when fish were fed 6 times a day than in the two other treatments (25.7 ± 1.4% against 33.6–35.0 ± 0.4% and 42.7 ± 5.5% against 62.0–63.3 ± 5.5% respectively). Fish protein content was significantly affected by temperature only ( P < 0.05) and was lower at 28 °C than at 20 or 24 °C (13.6 ± 0.3% against 15.9–16.3 ± 0.3% respectively). No significant effect was observed on the fish lipid content. The best growth performances (WG and FE) were observed when fish were reared at 28 °C and fed 3 times a day. At this feeding frequency, the optimal feeding rates were estimated as 1.5, 1.8 and 2.0% of fish body weight at 20, 24 and 28 °C respectively. Further studies investigating the effect of these factors on larger fish (100–2000 g) are required. In addition, the effects of other main factors influencing growth like photoperiod should be investigated.