Compensatory Growth of Juvenile Olive Flounder, Paralichthys olivaceus L., and Changes in Proximate Composition and Body Condition Indexes during Fasting and after Refeeding in Summer Season

Compensatory growth of juvenile olive flounder, Paralichthys olivaceus L., and changes in proximate composition and body condition indexes of fish during fasting and after refeeding were investigated during the summer season. Groups of 25 fish each (initial body weight of 16 g) were randomly distributed into fifteen 180-L flow-through tanks. Fish were fed the experimental diet containing crude protein 46.9% and crude lipid 8.0% with estimated energy level of 14.6 kJ/g diet for 6 d/wk. Five treatments in triplicate were prepared for this study: C, S1, S2, S3, and S4. Fish in the control group (C) were hand-fed to apparent satiation twice daily. Fish in treatments S1, S2, S3, and S4 experienced 1, 2, 3, and 4 wk of starvation and were then hand-fed to apparent satiation twice daily during the remaining 7, 6, 5, and 4 wk of the experiment, respectively. A group of starved fish in the similar size was stocked and fasted throughout the 8-wk feeding trial for chemical and blood analysis. The feeding trial lasted for 8 wk. Weight of fish linearly decreased with week of starvation (P   0.05) affected by feeding strategy. However, weight gain and specific growth rate (SGR) of olive flounder in C, S1, and S2 were significantly (P   0.05) different from those of fish in S2 but significantly (P   0.05) affected by feeding strategy. Chemical composition of fish was not significantly (P > 0.05) affected by feeding strategy. In considering these results, it can be concluded that juvenile olive flounder have the ability to fully compensate for 2-wk feed deprivation during the summer season. Besides, feed efficiency in fish fed for 7 and 6 wk after 1- and 2-wk feed deprivation was comparable to that in fish fed for 8 wk.