SummaryGrowth and food intake of juvenile flounders from the Kiel Bight were measured experimentally at different salinities (0, 5, 15 and 35 %). The growth at the middle levels (5 and 15 %) was faster then at 0 and 35 %. The reason for lower rates of increase in the freshwater group is the lower food intake. In the 35 % group the slower growth is caused by the worse food conversion. The variance of the individual growth rates in the 15 % salinity group remains far below the values of all other groups.