A single phase of food deprivation provoked compensatory growth in barramundi Lates calcarifer

Abstract

Compensatory growth of juvenile barramundi, Lates calcarifer (Bloch) was investigated at 28 °C for 8 weeks. Fish were divided into four feeding groups including one group with continuous feeding (C) and three other groups with food deprivation for 1 week (S1), 2 weeks (S2) and 3 weeks (S3), respectively. All starved fish resumed feeding in week 4. Changes in body weight, specific growth rate, feeding rate, food conversion efficiency and apparent digestion rate were examined weekly during the re-feeding period. Chemical compositions of fish were separately determined at the end of week 3 and week 8. Fish starved for 1 week reached the same weight as the control fish after re-feeding for 3 weeks, indicating that complete compensatory growth occurred. Although the specific growth rate in S2 or S3 fish was greater than that in the control fish after re-feeding, neither S2 nor S3 fish reached the same body weight of the control fish at the end. The feeding rates of S1, S2 and S3 fish were greater than those of control fish for a period of 2, 3 and 4 weeks, respectively. No significant differences in feeding rates were found among S1, S2 and S3 fish in the second week of re-feeding. Neither food conversion efficiency nor apparent digestion rate was significantly different among all treatments except that conversion efficiencies of S1 and the control fish were greater than those of S2 and S3 fish in week 7. At the end of food deprivation, the ratio of lipid to lean body mass (LBM) and the concentration of lipid, energy and moisture in S1, S2 and S3 fish were significantly less than those in the control fish, but the protein concentration in the control fish was greater than that in S2 or S3 fish. After re-feeding for 5 weeks, no difference in the concentrations of protein, ash, energy and moisture were detected among all treatments; however, the lipid concentration in S2 and S3 fish was less than that in the control fish. All fish deprived of food displayed a lower ratio of lipid to lean body weight than that in the control fish. Our results indicate that compensatory growth occurred in barramundi and the magnitude and duration of compensatory growth depended on the length of food deprivation.