title: Administration of hot-water extract of brown seaweed Sargassum duplicatum via immersion and injection enhances the immune resistance of white shrimp Litopenaeus vannamei.
abstract: The total haemocyte count (THC), phenoloxidase activity, and respiratory burst were examined when the white shrimp Litopenaeus vannamei (10.42+/-1.39 g) were immersed in seawater (34 per thousand) containing hot-water extract of brown alga Sargassum duplicatum at 100, 300 and 500 mg l(-1), or injected with hot-water extract of S. duplicatum at 2, 6, 10 and 20 microg g(-1). These parameters increased significantly when the shrimp were immersed in seawater containing hot-water extract at 300 and 500 mg l(-1) after 1 h, or when the shrimp were injected with hot-water extract at 10 and 20 microg g(-1) after 1 day. L. vannamei that were injected with hot-water extract at 6, 10 and 20 microg g(-1) had increased phagocytic activity and clearance efficiency to V. alginolyticus after 1-6 days. In another experiment, L. vannamei which had been immersed in seawater containing hot-water extract at 100, 300 and 500 mg l(-1), or injected with hot-water extract at 2, 6, 10 or 20 microg g(-1) were challenged with V. alginolyticus at 1 x 10(6), or 1.4 x 10(6) colony-forming units (cfu) shrimp(-1), and then placed in seawater. The survival of shrimp that received hot-water extract at either dose was significantly higher than that of control shrimp after 2 days, as well as at the termination of the experiment (6 days after the challenge). It is therefore concluded that L. vannamei that were immersed in hot-water extract of S. duplicatum at 300 mg l(-1), or the shrimp that were injected with hot-water extract at 10 microg g(-1) or less had increased immune ability as well as resistance to V. alginolyticus infection.
authors: Department of Aquaculture, College of Life and Resource Sciences, National Taiwan Ocean University, Keelung 202, Taiwan, ROC.
authors: Su-Tuen
authors: ST
authors: Yeh
authors: Chiu-Sha
authors: CS
authors: Lee
authors: Jiann-Chu
authors: JC
authors: Chen
mesh_terms: D000818:Animals; D017756:Aquaculture / Q000379:methods*; D045424:Complex Mixtures / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006434:Hemocytes / Q000276:immunology; D007101:Immersion; D014442:Monophenol Monooxygenase / Q000378:metabolism; D033561:Penaeidae / Q000187:drug effects / Q000276:immunology*; D016897:Respiratory Burst / Q000187:drug effects / Q000276:immunology; D044647:Sargassum / Q000737:chemistry*; D016019:Survival Analysis
chemical_list: D045424:Complex Mixtures; D014442:Monophenol Monooxygenase