절식과 먹이 공급에 의한 해상 가두리에서의 감성돔의 성장

Abstract

An experiment was conducted to investigate the effects of the weekly cycles of feed deprivation and re-feeding on growth and feed consumption of black sea bream, Acanthopagrus schlegeli (initial mean weight 9.2 ± 1.9 g), cultured in floating sea cages. Fish were held under natural fall-winter (34°37 &apos; N, 127°42&apos; E) photoperiod and ambient water temperatures (24.8-13.0℃, mean 18.8℃) for 12 weeks. Fish were fed to satiation feeding weekly cycles as follow; on day 7 (F7.0), day 6 (F6.1: 6 days feeding and 1 day deprivation), day 5 (F5.1: 5 days feeding and 1 day deprivation), day 4 (F4.1: 4 days feeding and 1 day deprivation), day 3 (F 3.1: 3 days feeding and 1 day deprivation), day 2 (F2.1: 2 days feeding and 1 day deprivation) and every other day (F1.1). At the end of experiment there was no significant difference in weight between the fish fed continuously (F7.0) and those of F6.1, F5.1, F4.1 and F3.1 groups, but fish weight in F2.1 and F1.1 groups was significantly lower than that of control group and fish weight in F1.1 group was significantly lower than those of the other feeding groups (P<0.05). The SGRs in F2.1 and F1.1 fish that had experienced the longest feed deprivation periods were always higher than those in the control fish during the experimental periods (P<0.05). Total feed supplied to group F7.0, F6.1, F5.1, F4.1, F3.1, F2.1 and F1.1 was 35.1, 30.1, 29.9, 29.1, 28.2, 26.7 and 22.6 kg, respectively. Feeding rates in F2.1 and F1.1 fish were always higher than those in the control fish during the experimental periods (P<0.05). Overall food conversion efficiency in F2.1 fish for the 12 week feeding trial was only significantly higher than that in control fish (P<0.05). The results could be applied to weekly feeding schedules for black sea bream culture in the floating sea cage during fall and winter season in Korea.