The voluntary feed intake (VFI) and growth rate of sea bass were studied for 147 days, based on different starting live weights, under natural photoperiods and varied water temperatures. Sea bass (n = 720) were divided into five weight classes (60-70, 90-110, 130-150, 160-180 and 230-250 g) and distributed among 20 tanks. Seven different water temperatures were compared: 13, 16, 19, 22, 25, 28 and 31 degrees C. A commercial extruded diet (N x 6.25, 43.7% DM; crude fat, 25.7% DM) was used. The trial was performed in a closed-circuit plant, with a daily water turnover rate of 10%. Each tank was fitted with an apparatus for collecting the uneaten food. Automatic feeders distributed equal amounts of food for ten meals per day. The daily food allowance was adjusted, based on fish biomass, to permit ad libitum feeding and to leave approximately 20% uneaten. Fish were exposed to natural photoperiod (March-July). Non-linear regression equations were used to calculate the best-fitting curves for the data.