半封闭循环水养殖系统中高体革鯻养殖密度研究

在半循环水养殖系统中研究了养殖密度对体重为50～100 g的高体革鯻苗种的影响。试验设置3个密度组:低密度组100尾/m3(5 kg/m3)、中密度组260尾/m3(13 kg/m3)和高密度组360尾/m3(18 kg/m3)。研究表明:各密度组中试验鱼的生长表现出了明显的差异,生长效率、特定生长率和日增重随着养殖密度的升高而明显降低;大小变动系数和饵料系数随着养殖密度的升高而明显增加。对试验鱼的生理指标分析表明,试验初期,密度对试验鱼血清中的皮质醇、补体C3、谷草转氨酶(ALT)和谷丙转氨酶(AST)有显著影响;试验结束时,3个密度组试验鱼血清中的皮质醇、谷草转氨酶和谷丙转氨酶没有明显差异。综合对检测指标的结果分析,认为本试验条件下,体重50～100 g的高体革鯻幼鱼的比较适宜的养殖密度是260尾/m3。研究亮点:(1)高体革鯻是近年来逐渐引起关注的优良淡水养殖品种,比较适合高密度集约化养殖,但关于其适宜养殖密度的研究尚未见报道。研究高体革鯻幼鱼的适宜养殖密度,希望为生产提供理论基础。(2)不仅分析了常规的生长指标和生理指标,将部分生产指标一并纳入分析,作为评价养殖密度适宜性的标准。

The stocking density of Scortum barcoo juveniles in the semi recirculating aquaculture system

The influence of density on the welfare of juvenile jade perch during the 50–100 g growth stage was investigated in this paper.The experiment was conducted in tanks equipped with a biological filter,and two tanks for each density were used.The three densities studied were low density(LD,100 fish /m3,5 kg/m3),medium density(MD,260 fish/m3,13 kg/m3),and high density(HD,360 fish/m3,18k g/m3).The experiment lasted 45 d.The welfare of the fish was studied by recording growth and physiological parameters during the whole period.Within the size and density range tested,fish welfare was impacted negatively by increasing density.The serum cortisol,alanine aminotransferase(ALT) activity,and aspartate aminotransferase(AST) activity levels differed significantly(P < 0.05) among the three densities in 15 d,but at the end of the experiment(45 d) the significance disappeared.The effect of density on the serum C3 level was delayed,and a significant difference was not detected until the experiment ended.The body weight showed a significant difference among the three densities.The average body weight of the LD group was 96.62 ± 2.99 g,and that of the HD group was(75.54±6.36) g.The results showed that although the perch in this study were able to withstand the negative effects of high stocking density,it still influenced the fish’s growth.