Effect of density and mixed culture of largemouth bass (Micropterus salmoides) and pikeperch (Sander lucioperca) on growth, survival and feed conversion rate in intensive culture

In this study, two experiments were performed with the aim to optimize intensive aquaculture of largemouth bass (Micropterus salmoides). In the first 140-day experiment the effect of the initial fish density was assessed at three levels: low density (LD) 23 kg/m3, medium density (MD) 35 kg/m3 and high density (HD) 46 kg/m3. All three densities provided the same final Fulton's condition coefficient (FC = 1.24-1.28), specific growth rate (SGR = 0.22-0.24%/day) and survival rate (97-100%). No cannibalism was observed at all tested densities. Feed conversion ratio (FCR = 1.39 ± 0.21 g/g) was the lowest for LD and the highest (1.61 ± 0.08 g/g) for MD. The highest fish biomass (25.7 ± 2.7 kg/m3) was obtained at HD and this density was considered as the most effective density of all tested ones during the intensive culture of largemouth bass. The second 60-day experiment tested the effect of largemouth bass and pikeperch (Sander lucioperca) monoculture and biculture of both species on production efficiency. Higher size heterogeneity was obtained in both (mono- and bicultural) groups of pikeperch (308.91-314.56‰/day) compared to the groups of largemouth bass (279.26-284.05 ‰/day). The higher FC (1.09) was found in both types of culture in largemouth bass compared to both methods of culture in pikeperch (0.74-0.78). The lowest SGR was evident in both types of largemouth bass cultures (1.20-1.28%/day). In contrast, the highest SGR was achieved in the bicultural pikeperch (1.88%/day). Similar results like for SGR were also assessed for FCR, where the highest value of FCR was in both cultures of largemouth bass (1.44-1.48 g/g) compared to the lowest FCR in the bicultural of pikeperch (0.73 g/g). Largemouth bass in both tested types of culture had higher survival rates (99.95-99.99%) compared to pikeperch (98.61-98.63%).