Effect of water temperature on the immune response of white shrimp Litopenaeus vannamei to Vibrio alginolyticus

Abstract

White shrimp Litopenaeus vannamei held in 25 parts per thousand seawater at 27 degrees C or 28 degrees C were injected with TSB-grown Vibrio, alginolyticus at 1x10(4) colony-forming units (cfu) shrimp(-1) or 1x10(5) cfu shrimp(-1), and then cultivated onward at water temperatures varying from 20 to 34 degrees C. Over 24-144 h, mortality of V. alginolyticus-injected shrimp held at 34 degrees C or 32 degrees C was significantly higher than that of shrimp held at lower temperatures. In a separate experiment, shrimp held in 25 parts per thousand seawater at 28 degrees C and then cultured onward at 20 to 32 degrees C were examined for immune parameters at 24-96 h. THC, phenoloxidase activity, respiratory burst, and SOD activity decreased significantly at 24 h after transfer to 32 degrees C. Shrimp held in 25 parts per thousand seawater at 27 degrees C and then cultured onward at 20 to 34 degrees C showed a significant reduction in phagocytic activity and clearance efficiency for V. alginolyticus at 24 h after transfer to 34 degrees C. It was concluded that transfer of shrimp from 27 or 28 degrees C to higher temperatures (32 and 34 degrees C) reduced their immune capability and decreased resistance to V. alginolyticus infection. (c) 2005 Elsevier B.V. All rights reserved.