Li Chang-Che, Chen Jiann-Chu
Department of Aquaculture, College of Life Sciences, National Taiwan Ocean University, Keelung 202, Taiwan, ROC.
Fish Shellfish Immunol. 2008 Dec;25(6):701-9. doi: 10.1016/j.fsi.2008.01.007. Epub 2008 Jan 25.
White shrimp Litopenaeus vannamei (also known as Penaeus vannamei) held in 34 per thousand seawater at pH 8.2 were injected with tryptic soy broth (TSB)-grown Vibrio alginolyticus at 8 x 10(5) colony-forming units (cfu) shrimp(-1), and then transferred to tanks at pH 6.5, 8.2 (control) and 10.1, respectively. After 24-168 h, the mortality of V. alginolyticus-injected shrimp that were transferred to pH 6.5 and pH 10.1 tanks was significantly higher than that of V. alginolyticus-injected shrimp held at pH 8.2. In another experiment, L. vannamei held at pH 8.2 following transfer to pH 6.5, 8.2 (control) and 10.1 for 6, 12, 24, 72 and 120 h were examined for immune parameters, phagocytic activity, and the clearance efficiency of shrimp against V. alginolyticus. The results indicated that the shrimp that were transferred to pH 6.5 and 10.1 showed significantly decreased phenoloxidase (PO) activity, respiratory burst, phagocytic activity, and clearance efficiency against V. alginolyticus over 6-72 h; significantly decreased superoxide dismutase (SOD) activity over 6-24h; and decreased total haemocyte count (THC) over 12-72 h. Shrimp transferred to pH 10.1 showed significantly decreased granular cell counts, and THC after 6h, and decreased SOD activity after 72 h. The immune parameters of shrimp transferred to pH 6.5 and 10.1 returned to the original values after 120 h. However, shrimp transferred to pH 6.5 still maintained lower phagocytic activity, and clearance efficiency against V. alginolyticus, and shrimp transferred to pH 10.1 still maintained lower clearance efficiency against V. alginolyticus. It was therefore concluded that low pH and high pH stress decrease the resistance of white shrimp L. vannamei against V. alginolyticus and decrease several parameters of the immune response.
将凡纳滨对虾（也称为南美白对虾）饲养在盐度为34‰、pH值为8.2的海水中，每尾虾注射8×10⁵ 菌落形成单位（cfu）的胰蛋白胨大豆肉汤（TSB）培养的溶藻弧菌，然后分别转移到pH值为6.5、8.2（对照）和10.1的养殖池中。24 - 168小时后，转移到pH值为6.5和10.1养殖池中的注射溶藻弧菌的对虾死亡率显著高于饲养在pH值为8.2的注射溶藻弧菌的对虾。在另一项实验中，将凡纳滨对虾饲养在pH值为8.2的环境中，之后分别转移到pH值为6.5、8.2（对照）和10.1的环境中6、12、24、72和120小时，检测其免疫参数、吞噬活性以及对溶藻弧菌的清除效率。结果表明，转移到pH值为6.5和10.1环境中的对虾在6 - 72小时内酚氧化酶（PO）活性、呼吸爆发、吞噬活性以及对溶藻弧菌的清除效率显著降低；在6 - 24小时内超氧化物歧化酶（SOD）活性显著降低；在12 - 72小时内总血细胞计数（THC）降低。转移到pH值为10.1环境中的对虾在6小时后颗粒细胞计数和THC显著降低，在72小时后SOD活性降低。转移到pH值为6.5和10.1环境中的对虾的免疫参数在120小时后恢复到初始值。然而，转移到pH值为6.5环境中的对虾仍保持较低的吞噬活性和对溶藻弧菌的清除效率，转移到pH值为10.1环境中的对虾仍保持较低的对溶藻弧菌的清除效率。因此得出结论，低pH值和高pH值应激会降低凡纳滨对虾对溶藻弧菌的抵抗力，并降低免疫反应的几个参数。
