不同养殖密度对中国明对虾生长和能量代谢的影响

Effects of different stocking densities on the growth and energy metabolism of Fenneropenaeus chinensis

中文关键词: 中国明对虾  密度  生长  能量代谢

英文关键词: Fenneropenaeus chinensis  Stocking density  Growth  Energy metabolism

中文摘要:

      本研究采用网箱养殖的方法，通过室内28 d的养殖实验，在4个养殖密度G1(100尾/ m3)、G2(200尾/m3)、G3(300尾/m3)、G4(400尾/m3)组中，研究不同养殖密度对中国明对虾(Fenneropenaeus chinensis)生长、能量代谢和代谢酶活力的影响。结果显示，G2组的增重率(WGR)、相对增长率(AGR)和特定生长率(SGR)均最高，与G1组相比差异不显著(P>0.05)；G3和G4组的体重差异系数(CVW)显著升高(P<0.05)，其他生长指标和成活率(SR)均显著低于G1组(P<0.05)；G4与G1组相比差异极显著(P<0.01)。随着养殖密度的增加，G3和G4组显著提高了血淋巴葡萄糖(Glc)、乳酸(LA)、丙酮酸(PA)的含量(P<0.05)，显著降低了甘油三酯(TG)的含量(P<0.05)；G2组4种指标含量与G1组相比差异不显著(P>0.05)，而氨基酸含量在不同养殖密度之间变化不显著(P>0.05)，表明在密度胁迫下，高密度对能源的需求增加，中国明对虾倾向性利用糖类脂类作为能源。另外，G3和G4组的己糖激酶(HK)、丙酮酸激酶(PK)、6-磷酸果糖激酶(6-PEK)和乳酸脱氢酶(LDH)活性均显著升高(P<0.05)，说明机体氧化代谢途径发生变化，分解代谢增强。琥珀酸脱氢酶(SDH)活性显著降低(P<0.05)，表明三羧酸循环活性的降低，进一步表明密度胁迫抑制了组织的有氧代谢。研究表明，G3和G4组养殖密度显著影响了中国明对虾的生长，增加了碳水化合物和脂类利用，抑制了组织的有氧代谢。当中国明对虾为4.5 g时，其养殖密度100~200尾/m3为宜。

英文摘要:

      The effects of four socking densities [G1 (100 ind./m3), G2 (200 ind./m3), G3 (300 ind./m3), and G4 (400 ind./m3)] on the growth indices, energy metabolism content, and metabolic enzyme activity of Fenneropenaeus chinensis were studied in a 28-day indoor culture experiment via the cage culture method. The results showed that the weight gain rate, relative growth rate, and specific growth rate of the G2 group were highest and did not differ from G1 (P>0.05). The weight difference coefficient of G3 and G4 increased significantly (P<0.05). The weight gain rate, relative growth rate, specific growth rate, and survival rate were significantly lower than G1 (P<0.05), and the G4 group differed significantly from the G1 group (P<0.01). The G3 and G4 groups significantly increased the levels of hemolymph glucose, lactic acid, and pyruvate (P<0.05) and reduced the triglycerides content (P<0.05). The glucose, lactic acid, pyruvate, and triglyceride contents of G2 did not differ from G1 (P>0.05). The amino acid content also did not vary between densities (P>0.05). This indicates that high-density stress can increase energy demands, and F. chinensis tend to use sugars and lipids as energy sources when experiencing density stress. The activities of hexokinase, pyruvate kinase, 6-phosphate fructokinase, and lactate dehydrogenase in G3 and G4 were significantly increased (P<0.05), suggesting changes in the body's oxidative metabolism pathways and increased catabolism. Succinate dehydrogenation enzyme activity was significantly reduced (P<0.05), indicating a decrease in tricarboxylic acid cycle activity. This provides further evidence that density stress inhibited aerobic metabolism. In summary, growth in the G3 and G4 groups was significantly affected, there was increased use of carbohydrates and lipids, and aerobic metabolism of the tissues was inhibited in F. chinensis. Therefore, 100~200 ind./m3 is recommended as the appropriate density when F. chinensis are 4.5 g.