GROWTH AND FEEDING RESPONSES OF A HATCHERY POPULATION OF BROWN TROUT (SALMO-TRUTTA L) AT LOW-TEMPERATURES

Feed intake, specific growth rate and changes in body composition were studied in age 1+(140-190 g) brown trout (Salmo trutta L.) reared at three temperatures (2, 4 and 6 degrees C) under continuous light condi tions. Feed intake increased from 35.7 ka kJ.kg(-1).day(-1) at 2 degre es C to 95.7 kJ.kg(-1).day(-1) at 6 degrees C, and the growth rate inc reased from 0.19%.day(-1) to 0.42%.day(-1) over the same temperature r ange. The estimated lower temperature Limits for feeding and growth we re slightly above 0 degrees C, For all groups of fish, the majority (a bout 75%) of the weight gain comprised water and protein, but Lipid de position tended to increase with increasing temperature. The depositio n of lipid accounted for about 50% of the body energy gain at all temp eratures.