Effects of temperature and rearing density on growth of juvenile European whitefish (Coregonus macrophthalmus) in aquaculture

Decreasing fisheries yields of the common lake whitefish in Lake Constance have prompted efforts to farm the local form, known as 'Felchen' (Coregonus macrophthalmus). This study set out to establish the influence of temperature and density on this specialized form under aquaculture conditions, investigating the effect of two temperature regimes (10.5 °C and 14.7°C) and three rearing densities (starting conditions: 3.75 kg m^-3, 7.5 kg m^-3 and 15 kg m^-3) on mortality, growth, feed conversion ratio and body composition of one-year-old whitefish fingerlings (initial weight 11.2 g ± 0.5) over a period of 70 days. Mortality remained low in all treatments and appeared unaffected by water temperature or rearing density. However as expected, water temperature did have a strong effect on growth and feed efficiency, with specific growth rate and feed conversion ratio significantly higher at 14.7°C than at 10.5 °C. Increased density had a negative influence on growth and feed conversion. In conclusion, a higher rearing temperature and low density appears beneficial for the aquaculture of Lake Constance whitefish (Coregonus macrophthalmus).