密度胁迫对黄姑鱼幼鱼生长、代谢及非特异性免疫的影响

Impact of density stress on growth, metabolism and non-specific immune functions of juvenile Nibea albiflora

关键词:  黄姑鱼  密度胁迫  生长  代谢  非特异性免疫

Key words:  Nibea albiflora  Density stress  Growth  Metabolism  Non-specific immune functions

摘要:

随机选取体质量为10.0~10.7g的黄姑鱼Nibea albiflora幼鱼450尾，设置4个养殖密度，依次为15尾/缸（1.49 kg/m3）、30尾/缸（3.00 kg/m3）、45尾/缸（4.84 kg/m3）、60尾/缸（5.81 kg/m3），研究密度胁迫对黄姑鱼幼鱼生长性能、代谢酶活性及非特异性免疫的影响。结果表明: 1) 养殖密度对黄姑鱼幼鱼的增重率没有显著性影响（P＞0.05）。特定生长率具有与增重率相类似的变化规律。饵料系数与养殖密度呈显著的负相关性：FCR=0.02G+0.11(n=15，R2=0.983，F＜0.05）。2) G60组乳酸脱氢酶活性最高并显著高于G15组、G30组（P＜0.05）。随着养殖密度的增大，谷丙转氨酶活性有逐渐增大的趋势（P＞0.05）。谷草转氨酶活性具有与谷丙转氨酶相类似的变化规律。3) 随着养殖密度的增大，血清溶菌酶活性呈现逐渐降低的趋势，G60组血清溶菌酶活性最低并显著低于其他3组（P＜0.05）。密度胁迫对血清补体C3、C4含量的影响均不显著（P＞0.05）。本研究表明，养殖密度过高会对黄姑鱼幼鱼的代谢及非特异性免疫造成负面影响，而养殖密度过低又会造成水资源的浪费，30尾/缸（3.00kg/m3）为较适宜的养殖密度。

Abstract:

Four hundred and fifty Nibea albiflora juveniles(10.0~10.7g) were randomly distributed in four experimental treatments at different culture densities: 15ind/tank (1.49 kg/m3), 30ind/tank (3.00kg/m3), 45ind/tank (4.84 kg/m3), and 60ind/tank (5.81 kg/m3). A 30-day feeding experiment was conducted to investigate the impact of density stress on growth performance, feed coefficient, plasma complement of C3 and C4, and activity of related enzymes of the fish. Weight gain (WG) did not show significant differences among treatments.The trend of specific growth rate (SGR) was similar to that of WG. Feed conversion rate (FCR) increased with the increasing density. FCR of G60 was the highest and significantly higher than the other treatments (P＜0.05). (2) Activity of lactic dehydrogenase (LDH) in G60 was the highest and significantly higher than other treatments（P＜0.05）. Glutamic pyruvic transaminase (GPT/ALT) activity increased with the increase of density, while there were no significant differences among the treatments (P＞0.05). Similar trend was found in activity of glutamic oxaloacetic transaminase (GOT/AST). (3) The activity of lysozyme in serum decreased with the increase of density. The activity of lysozyme in G60 was the lowest and significantly lower than the other treatments (P＜0.05). Both complement of C3 and C4 in G30 were the highest, but they were not significantly affected by density (P＞0.05). This study indicated that high stocking density may impact metabolism and non-specific immune functions of juvenile N.albiflora, while low stocking density would suffer a great waste of water resource. Thirty individuals per tank（3.00 kg/m3）was considered to be a suitable stocking density.