流水养殖条件下养殖密度对俄罗斯鲟幼鱼非特异性免疫的影响

Effects of Stocking Density on the Non-Specific Immune Functions of Juvenile Russian Sturgeon (Acipenser gueldenstaedti) in Flowing Water Cultivation

关键词:  俄罗斯鲟  养殖密度  超氧化物歧化酶  代谢  非特异性免疫

Key words:  Russian sturgeon  stocking density  SOD  metabolism  non-specific immune functions

摘要:

[目的]为了给俄罗斯鲟鱼(Acipenser gueldenstaedti)养殖管理提供借鉴,研究流水养殖系统中不同养殖密度对俄罗斯鲟幼鱼非特异性免疫的影响。[方法]选取初始体重为(29.70±1.32) g的俄罗斯鲟幼鱼分置于2.5 kg/m³(SD1)、3.6 kg/m³(SD2)和4.7 kg/m³(SD3)3个养殖密度进行流水池塘(4.4 m×4.4 m×0.45 m)养殖,每个密度设3个重复,实验周期为90 d。[结果]SD3组幼鱼超氧化物歧化酶(SOD)活性显著低于SD1组和SD2组(P<0.05),表明较高的养殖密度打破机体抗氧化系统的平衡,抑制机体抗氧化功能的发挥。SD3组幼鱼丙二醛(MDA)含量显著高于SD1组、SD2组(P<0.05),这是脂质过氧化反应增强,脂质过氧化产物增多的表现。随着养殖密度增加俄罗斯鲟幼鱼谷草转氨酶AST和谷丙转氨酶ALT活性逐渐升高,肝体指数降低。SD3组俄罗斯鲟幼鱼脾脏系数显著低于SD1、SD2组水平(P<0.05),血液溶菌酶活性以及C3补体因子含量也显著降低。[结论]过分提高养殖密度,将会导致俄罗斯鲟幼鱼出现拥挤胁迫,使机体的自由基"稳态性动态平衡"遭受破坏,影响机体的正常生理状态,肝脏和脾脏均受损,免疫功能也受到一定程度的抑制,且随养殖密度增加抑制效应愈加严重。

Abstract:

[Objective] This study was conducted to investigate the effect of different stocking density on the non-specific immune functions of juvenile Russian sturgeon (Acipenser gueldenstaedti).[Methods] Three triplicate groups of juveniles (initial body weight(29.7±1.32) g)were reared in nine square concrete ponds(4.4 m×4.4 m×0.45 m) at three stocking densities(2.5 kg/m³(SD1), 3.6 kg/m³(SD2) and 4.7 kg/m³(SD3)) for 90 d.[Results] The results showed that the SOD activity in high stocking density was significantly lower than that in low stocking density (P<0.05), which indicated that the high stocking density might break the balance of the body's antioxidant system and inhibit the antioxidant function. Meanwhile, the MDA content in the group SD3 was significantly higher than that in the group SD1 and SD2 (P<0.05), which came from the enhancement of lipid peroxidation. At the end of the experiment, the activities of AST and ALT gradually increased than the beginning (P<0.05), and the hepatosomatic index decreased with the increase of the planting density, but there was no significant difference (P>0.05).The spleen coefficient in the group SD3 was significantly lower than that in the group SD1 and SD2.The lysozyme activity and C3 complement factor had the same changing trend.[Conclusion] The experimental results indicated that the crowding stress resulting from the excessive stocking density could break the balance of free radical unstable state and affect the normal physiological state.