盐度变化对锯缘青蟹Scylla serrata免疫因子的胁迫影响

在实验室条件下测定了在盐度5.0,10.0,17.5,25.0,35.0胁迫0,12,24,48,72和96 h,锯缘青蟹血细胞总数(THC)、血细胞吞噬能力及其血清中溶菌酶(LZM)、超氧化物歧化酶(SOD)、碱性磷酸酶(AKP)、酸性磷酸酶(ACP)、过氧化物酶(POD)、酚氧化酶(PO)、溶血素等免疫相关因子的活力变化。结果表明：各梯度盐度胁迫下THC明显下降,其他免疫指标均在12至24 h出现一个峰值变化,而后趋于平稳。在12 h盐度5.0和35.0组吞噬百分比(PP)、吞噬指数(PI)值高于对照组,盐度10.0和25.0组的LZM,PO活力显著高于对照组,除盐度5.0组以外的ACK,APK活力均高于对照组；POD、溶血素活力在盐度10.0和25.0组显示随时间的延续而增高,分别在72和24 h达到最大值,且极显著高于对照组；SOD的变化不显著。说明盐度突变对锯缘青蟹各相关免疫因子均有影响,低浓度短时间的盐度胁迫能引起应激反应,适当提高其免疫力,而大幅度长时间的盐度胁迫可显著影响锯缘青蟹的抗病力。

Effects of salinity challenge on the immune factors of Scylla serrata

In this study the changes of total haemocyte count(THC), phagocytic activity to Escherichia coil, and activities of lysozyme(LZM), superoxide dismutase activity(SOD), alkaline phosohatase(AKP), acidic phosohatase(ACP), peroxidase(POD), phenoloxidase(PO) and hemolysin in the serum of Scylla serrata were examined in the treatments of different salinity concentrations(5.0,10.0,17.5,25.0,35.0) after 0,12,24,48,72 and 96 h. The results showed that THC dramatically declined in different salinity treatments while other immune factors showed a peak value during 12 h to 24 h, and then tended to be stable. When Scylla serrata were exposed to salinity for 12 h, the phagocytic percentage (PP) and phagocytic index (PI) in the salinity treatments of 5.0 and 35.0 were higher than the control group. The activity of LZM and PO in the salinity treatments of 10.0 and 25.0 were significantly higher than the control group. The activities of ACK and APK were higher than the control group except in the salinity treatment of 5.0. The activity of POD and hemolysin in the salinity treatment of 10.0 and 25.0 increased with exposure time prolonging, and reached the highest values at 72 h and 24 h respectively, which were much higher than the control group while SOD showed no significant change. It was concluded that salinity was important to S. serrata immune response. The disease resistance of S. serrata could be enhanced when treated with lower concentration of salinity for a short period. However, when treated with higher salinity concentration for a long time, the disease resistance of S. serrata significantly decreased．