Compensatory growth in hybrid tilapia, Oreochromis mossambicus x O-niloticus, reared in seawater

Hybrid tilapia weighing 4.34 +/- 0.03 g (mean +/- SE) were reared in seawat er at 23.8 to 27.0 degrees C for 8 weeks. The control group was fed to sati ation twice a day throughout the experiment. The other three groups were de prived of feed for 1, 2, and 4 weeks, respectively, and then fed to satiati on during the refeeding period. At the end of the experiment, fish deprived for 1 week had similar body weights to the controls, whereas fish deprived for 2 and 4 weeks had significantly lower body weights than the controls. During the refeeding period, size-adjusted feed intakes and specific growth rates were significantly higher in deprived fish than in the controls, ind icating some compensatory responses in these fish. Feed intake and growth r ate upon refeeding were higher the longer the duration of deprivation. No s ignificant differences were found in digestibility, feed efficiency or prot ein and energy retention efficiency between the deprived and control fish d uring refeeding, suggesting that hyperphagia was the mechanism responsible for increased growth rates during compensatory growth. During refeeding, re lative gains in protein, lipid and ash, as proportions of total body weight gain, did not differ significantly among treatment groups. (C) 2000 Elsevi er Science B.V. All rights reserved.