[Objectives]This study was conducted to investigate the feeding intensity of different sizes of grass carp on water hyacinth.[Methods]Grass carp of 10 sizes,i.e.,50,100,150,200,250,300,350,400,450 and 500 g,were put i...[Objectives]This study was conducted to investigate the feeding intensity of different sizes of grass carp on water hyacinth.[Methods]Grass carp of 10 sizes,i.e.,50,100,150,200,250,300,350,400,450 and 500 g,were put in cages.Thirty grass carp were stocked in each cage,and only water hyacinth was fed.The grass carp were caught after 120 d,and the food intake and growth of the grass carp were analyzed.[Results]The body weight of all sizes of grass carp increased significantly,and the overall length of grass carp increased significantly.Compared with feeding feed,the body length and body weight in the experimental treatments were lower,and they were more slender;and the feed coefficient of small-sized grass carp was slightly larger than that of large-sized grass carp.When the stocking size was above 414.7 g,the net weight gain of grass carp increased rapidly,and the total food intake also increased.[Conclusions]This study provides a theoretical basis for achieving an ideal purification effect of water hyacinth on aquaculture water by maintaining the growth of grass carp and the biomass and coverage of water hyacinth within suitable ranges.展开更多
Juvenile turbot （Scophthalmus maximus） the initial stock densities at 0.28, 0.87, 1.12, 1.16, 2.75 were reared in five different experiment groups in kg/m^2 respectively for the study of the density effect on growth...Juvenile turbot （Scophthalmus maximus） the initial stock densities at 0.28, 0.87, 1.12, 1.16, 2.75 were reared in five different experiment groups in kg/m^2 respectively for the study of the density effect 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/m^2 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 whitened fish.展开更多
基金Supported by Shandong Provincial Key R&D Program(2015GNC110014)National Staple Freshwater Fish Industrial Technology System(CARS-45-44).
文摘[Objectives]This study was conducted to investigate the feeding intensity of different sizes of grass carp on water hyacinth.[Methods]Grass carp of 10 sizes,i.e.,50,100,150,200,250,300,350,400,450 and 500 g,were put in cages.Thirty grass carp were stocked in each cage,and only water hyacinth was fed.The grass carp were caught after 120 d,and the food intake and growth of the grass carp were analyzed.[Results]The body weight of all sizes of grass carp increased significantly,and the overall length of grass carp increased significantly.Compared with feeding feed,the body length and body weight in the experimental treatments were lower,and they were more slender;and the feed coefficient of small-sized grass carp was slightly larger than that of large-sized grass carp.When the stocking size was above 414.7 g,the net weight gain of grass carp increased rapidly,and the total food intake also increased.[Conclusions]This study provides a theoretical basis for achieving an ideal purification effect of water hyacinth on aquaculture water by maintaining the growth of grass carp and the biomass and coverage of water hyacinth within suitable ranges.
基金Supported by the Key Technology Research Program of Ministry of Agriculture (No. 04-11-01B) and the National High-tech Research and Development Program of China (863 Program) (No. 2004AA603320 and 2004AA603330)
文摘Juvenile turbot （Scophthalmus maximus） the initial stock densities at 0.28, 0.87, 1.12, 1.16, 2.75 were reared in five different experiment groups in kg/m^2 respectively for the study of the density effect 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/m^2 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 whitened fish.
