Turbot Scophthalmus maximus: stocking density on growth, pigmentation and feed conversion

Juvenile turbot (Scophthalmus maximus) were reared in five different experiment groups in the initial stock densities at 0.28, 0.87, 1.12, 1.16, 2.75 kg/m2 respectively for the study of the density ef- fect on growth, pigmentation and feed coefficient rate. The experiment lasted for 60 days with final stock densities at 1.91, 6.31, 8.86, 11.97, 17.67 kg/m2 respectively. Result showed that, in the same experiment condition, the stocking density has a positive effect on growth in low density and negative in high density. The SGR (special growth rate) was 3.189, 3.304, 3.447, 3.341, and 3.087 respectively. The uniformity of weight distributing among experiment groups decreased with increasing density. The stocking density had positive effect on feed coefficient rate. Group 1 had the least feed coefficient rate 0.96, and highest at 1.25 in Group 5, the highest density group. High stocking density inhibited the growth and increased the feed coefficient rate. The stocking density had negative relationship to pigmentation improvement for whit- ened fish.