慢性氨氮胁迫对罗氏沼虾生长与存活及能量代谢的影响

Effects of chronic ammonia nitrogen stress on growth,survival and energy metabolism of Macrobrachium rosenbergii

  • 摘要: 【目的】阐明慢性氨氮胁迫对罗氏沼虾生长、存活和能量代谢的影响及其适应机制,为罗氏沼虾的健康养殖提供理论依据。【方法】设0.02mg/L(对照)、0.50mg/L(T0.50)、1.04mg/L(T1.04)、2.14mg/L(T2.14)、4.42mg/L(T4.42)和9.03 mg/L(T9.03)6个不同氨氮浓度处理组,养殖48 d,研究慢性氨氮胁迫对罗氏沼虾摄食、生长、存活及血清供能物质含量和能量代谢相关酶活力的影响。【结果】T9.03组的罗氏沼虾存活率显著低于对照组(P<0.05,下同),其他胁迫组的存活率与对照组无显著差异(P>0.05,下同);摄食率、饵料效率及增重率、相对增长率和特定生长率均随着氨氮浓度的增加呈降低趋势,饵料系数和体重差异系数均随着氨氮浓度的增加呈上升趋势;血清葡萄糖(Glu)含量随着氨氮胁迫时间的延长总体上呈先升高后降低的变化趋势;在胁迫12 d后,血清甘油三酯(TG)和总胆固醇(TCHO)含量均随着氨氮浓度的增加呈下降趋势;在胁迫前24d,各胁迫组的血清总蛋白(TP)含量与对照组均无显著差异,而在第48 d,胁迫组的TP含量随着氨氮浓度的增加呈降低趋势,且除T0.50组外,其他胁迫组均显著低于对照组;血清乳酸(LA)含量随着氨氮浓度的增加总体上呈上升趋势。此外,胁迫组的肝胰腺己糖激酶(HK)、丙酮酸激酶(PK)及乳酸脱氢酶(LDH)活力均随着胁迫时间的延长呈先升高后降低的变化趋势;磷酸烯醇式丙酮酸羧基酶(PEPCK)活力在第12~48 d均有胁迫组显著高于对照组;在整个氨氮胁迫期间,琥珀酸脱氢酶(SDH)活力均随着氨氮浓度的增加呈降低趋势,T4.42和T9.03组的活力均显著低于对照组。【结论】氨氮对罗氏沼虾的最大无影响浓度为0.50mg/L;罗氏沼虾为应对慢性长期较高浓度的氨氮胁迫,能量供应和利用途径均发生明显变化,最终显著影响其摄食、生长和存活,造成养殖效果不佳。在集约化养殖中,应及时关注养殖水体的氨氮含量,减少氨氮胁迫对罗氏沼虾造成的额外耗能,提高生产效益。

     

    Abstract: 【Objective】To elucidate the effects of chronic ammonia nitrogen stress on the growth,survival and energy metabolism of Macrobrachium rosenbergi and its adaptive mechanism,it provided theoretical basis for healthy breeding of M. rosenbergii. 【Method】In this study,through 48 d cultivation experiment in the cultivation workshop,six different ammonia nitrogen concentrations were set:0.02 mg/L(control),0.50 mg/L(T0.50),1.04 mg/L(T1.04),2.14 mg/L(T2.14),4.42 mg/L(T4.42) and 9.03 mg/L(T9.03). The effects of chronic ammonia nitrogen stress on feeding,growth,survival,serum energy-supplying substances contents and enzymes related to energy metabolism of M. rosenbergii were studied.【Result】The results showed that the survival rate of T9.03 group was significantly lower than that of the control group(P<0.05,the same below),and there was no significant difference between survival rates of other stress groups and the control group(P>0.05,the same below). The feeding rate,feed efficiency,weight gain rate,relative growth rate and specific growth rate all showed a decreasing trend with the increase of ammonia nitrogen concentration,and the feed coefficient and weight difference coefficient showed an increasing trend with the increase of ammonia nitrogen concentration. Serum glucose(Glu) content increased first and then decreased with the duration of ammonia nitrogen stress. The contents of serum triglyceride(TG) and total cholesterol(T-CHO) decreased with the increase of ammonia concentration after 12 d of stress. There was no significant difference in serum total protein(TP) content between stress groups and the control group before 24 d of stress,but on day 48,TP content showed a decreasing trend with the increase of ammonia concentration in stress groups,moreover,except for the T0.50 group,all other stress groups were significantly lower than the control group.Serum lactic acid(LA) content showed an increasing trend with the increase of ammonia nitrogen concentration. In addition,the activities of hexokinase(HK),pyruvate kinase(PK) and lactate dehydrogenase(LDH) in the stress groups were increased first and then decreased later with the extension of the stress time; phosphoenolpyruvate carboxylase(PEPCK) activity was significantly higher in the stress group than in the control group during 12-48 d of experiment. The activity of succinate dehydrogenase(SDH) decreased with the increase of ammonia nitrogen concentration,and the activity of T4.42and T9.03 groups was significantly lower than that of the control group. 【Conclusion】The maximum concentration of ammonia nitrogen on M. rosenbergii was 0.50 mg/L. In order to cope with the chronic long-term high concentration of ammonia nitrogen stress,the energy supply and utilization route of M. rosenbergii changes significantly,which finally significantly affects its feeding,growth and survival,resulting in poor breeding effect. In intensive production,attention should be paid to the ammonia nitrogen content in aquaculture water to reduce the additional high energy consumption caused by ammonia nitrogen and improve the production efficiency.

     

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