不同养殖密度对翘嘴鳜生长、血液生化和抗氧化能力指标的影响

THE INFLUENCE OF STOCKING DENSITY ON THE GROWTH,BLOOD BIOCHEMISTRY,AND ANTIOXIDANT CAPACITY INDICATORS OF CHINESE PERCH(SINIPERCA CHUATSI)

研究旨在探讨不同养殖密度对翘嘴鳜(Siniperca chuatsi)生长、血液生化和抗氧化能力指标的影响。在循环水系统的水箱中(60 cm×60 cm×40 cm)于5种密度下[超低养殖密度组(ELD;3.34 kg/m^(3))、低养殖密度组(LD;9.51 kg/m^(3))、中等养殖密度组(MD;15.82 kg/m^(3))、高养殖密度组(HD;21.05 kg/m^(3))和超高养殖密度组(EHD;25.99 kg/m^(3))]养殖翘嘴鳜[平均体重(175.76±15.85)g]40d。结果表明,ELD组和LD组在增重率(WGR)和饲料转化率(FCR)方面表现出更好的生产性能(P<0.05),并增加血浆超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)的活性,同时减少丙二醛(MDA)的形成(P<0.05)。此外,EHD组的血浆葡萄糖水平、总胆固醇水平和甘油三酯水平均较高(P<0.05)。LD组刺鼠基因相关蛋白(agrp)的mRNA表达下降,而ELD组阿片促黑色素皮质激素原(pomc)基因表达下调。综上,推荐在循环系统中养殖翘嘴鳜的适宜放养密度为3.34—9.51 kg/m^(3)。

The present study was to explore the influence of stocking density on the growth,blood biochemistry,and antioxidant capacity indicators of Chinese perch(Siniperca chuatsi)cultured in the bank(60 cm×60 cm×40 cm)based recirculating systems for 40d.Fish(average weight 175.76±15.85 g)were reared in triplicate under five densities:extralow stocking density(ELD;3.34 kg/m^(3));low stocking density(LD;9.51 kg/m^(3));medium stocking density(MD;15.82 kg/m^(3));high stocking density(HD;21.05 kg/m^(3))and extra-high stocking density(EHD;25.99 kg/m^(3)).After 40 days,growth performance,biochemical parameters,appetite-related genes expression and stress indicators of fish were evaluated.The results showed that the ELD and LD groups showed better productive performance for weight gain(WG)and feed conversion ratio(FCR)(P<0.05),and increased plasma superoxide dismutase(SOD),catalase(CAT)and glutathione peroxidase(GSH-Px)activities,and decreased the formation of malondialdehyde(MDA)(P<0.05).Additionally,the EHD group performed higher glucose levels,cholesterol levels and lower triglyceride levels in plasma(P<0.05).The mRNA expression of agouti gene-related protein(agrp)was riesd in LD group,whereas gene expressions of proopiomelanocortin(pomc)resulted in a down-regulation in ELD group.In sum,the suitable stocking density for culturing Chinese perch in recirculating systems is recommended to be between 3.34 and 9.51 kg/m^(3).It is of great significance to select the best stocking density for improving the economic benefit of fish culture.