| Summary: | 碩士 === 國立臺灣海洋大學 === 水產養殖學系 === 100 === The immune parameters including haemogram, phenoloxidase (PO) activity, respiratory burst (RB), superoxide dismutase (SOD) activity and lysozyme activity of white shrimp Litopenaeus vannamei that received live V. alginolyticus, heat-killed Vibrio alginolyticus, and formalin-inactivated V. alginolyticus were examined. Immune parameters of shrimp that received live V. alginolyticus decreased after 0.5 day, to the lowest value after 1 day and slightly increased, but remained a lower value than the background value after 3-7 days. Immune parameter of shrimp that received heat-killed V. alginolyticus reached to the highest after 1 day and gradually decreased to the background value after 3-7 days. The immune parameters of shrimp that received formalin-inactivated V. alginolyticus decreased after 0.5 day, gradually increased to the highest after 5 days, and returned to the background value after 7 days, except lysozyme activity that remained unchanged from 0.5-7 days.
In a separate experiment, the immune parameters of shrimp which had been received heat-killed V. alginolyticus and formalin-inactivated V. alginolyticus for 7 days, and then challenged with a live V. alginolyticus were examined at 1-7 days post-challenge. The immune parameters of control shrimp that received live V. alginolyticus decreased after 0.5 day, to the lowest after 1 day and slightly increased, but remained a lower value than the background value after 3-7 days. HC, GC and THC of shrimp that received heat-killed V. alginolyticus decreased after 0.5 day, to the lowest after 1 day, and returned to background value after 3 days. However, PO activity, RB, SOD activity and lysozyme activity decreased after 0.5 day and returned to the background value after 1 day. The immune parameters of shrimp that received formalin-inactivated V. alginolyticus decreased after 0.5 day and then returned to background value after 1 day, except for GC that returned to the background value after 3 days.
Survival rate of white shrimp L. vannamei that received heat-killed V. alginolyticus and formalin-inactivated V. alginolyticus after 7 days, and then challenged with live V. alginolyticus at 6.8 x 106 cfu shrimp-1 were examined after 0.5-7 days. The survival rate of shrimp that received formalin-inactivated V. alginolyticus was 83.3%, and the survival rate of shrimp that received heat-killed V. alginolyticus was 70.0% over 5 to 7 days. The phagocytic activity to live V. alginolyticus in shrimp that received formalin-inactivated V. alginolyticus was significantly higher than that of shrimp that received heat-killed V. alginolyticus and control shrimp. It was concluded that immune memory occurs in shrimp, and vaccination could be applied to protect from Vibrio infection in shrimp farming.
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