Effects of starvation, refeeding, and feeding frequency on growth and digestive enzyme activity of Oplegnathus fasciatus

Abstract

The aim of this study was to investigate the effects of starvation,refeeding,and feeding frequency on the growth and digestive enzyme activity of rock bream(Oplegnathus fasciatus).In the starvation and refeeding experiment,the body weight,proteinase(pepsin and trypsin),and lipase activities decreased with increasing star-vation time.There were significant differences in body weight and pepsin activity between the control group and the group starved for 6 days.After 9 days of starvation,the lipase activity was significantly lower than that of the control group.The amylase activity fluctuated throughout the experimental period.After refeeding,the fish body weights and specific growth rates(SGRs) of all groups(except S3: starvation for 3 d and refeeding for 27d) were significantly lower than those of the control group.However,there were no significant differences in body weight and SGR between the S3 group and the control.The proteinase and lipase activities increased after recovery feed-ing.There was no significant difference in proteinase activity between the starved groups and the control.How-ever,the lipase activity after a relatively long period of starvation(9–12 days) did not return to the level of the control group.In the feeding frequency experiment,five experimental groups were fed 0.5,1,2,3 or 4 times per day in a 30-day trial.The results showed that SGR tended to increase with increased feeding frequency.However,there were no significant increases in SGR and digestive enzyme activity at higher feeding frequencies(more than twice per day).In conclusion,the results of this study indicate that juvenile O.fasciatus starved for 3 days had fully compen-satory growth ability,and the optimum feeding frequency was twice per day for juveniles of this species.