title: The immunostimulatory effects of hot-water extract of Gelidium amansii via immersion, injection and dietary administrations on white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus.
abstract: The total haemocyte count (THC), phenoloxidase activity, and respiratory burst were examined when white shrimp Litopenaeus vannamei were immersed in seawater (34 per thousand) containing hot-water extract of red alga Gelidium amansii at 200, 400 and 600 mg l(-1), injected with hot-water extract at 4 and 6 microg g(-1) shrimp, and fed diets containing hot-water extract at 0, 0.5, 1.0 and 2.0 g kg(-1). These parameters increased significantly when shrimp were immersed in seawater containing hot-water extract at 400 and 600 mg l(-1) after 1h, when shrimp were injected with hot-water extract at 6 microg g(-1) shrimp after one day, and when shrimp were fed diets containing hot-water extract at 1.0 and 2.0 g kg(-1) after 14 days. Phagocytic activity and clearance efficiency were significantly higher for the shrimp that were fed diets containing hot-water extract at 1.0 and 2.0 g kg(-1) than those of shrimp that were fed diets containing hot-water extract at 0 and 0.5 g kg(-1) after 14 and 28 days. In a separate experiment, L. vannamei which had received hot-water extract via injection, or fed diets containing hot-water extract, were challenged after 3h or 28 days with V. alginolyticus at 2 x 10(6) cfu shrimp(-1) and 1 x 10(6) cfu shrimp(-1), respectively, and then placed in seawater. The survival of shrimp that were injected with hot-water extract at 6 microg g(-1) was significantly higher than that of control shrimp after 1 day, and the survival of shrimp fed diets containing hot-water extract at 0.5, 1.0 and 2.0 g kg(-1) increased significantly after 3 days as well as at the end of the experiment (6 days after the challenge), respectively. It was concluded that L. vannamei that were immersed in hot-water extract at 400 mg l(-1), injected with hot-water extract at 6 microg g(-1) shrimp, and fed hot-water extract of G. amansii at 2.0 g kg(-1) or less showed increased immune ability as well as resistance to V. alginolyticus infection.
authors.affiliation: Department of Aquaculture, College of Life Sciences, National Taiwan Ocean University, Keelung 202, Taiwan, ROC.
authors.forename: Yu-Win
authors.initials: YW
authors.lastname: Fu
authors.forename: Wen-Ying
authors.initials: WY
authors.lastname: Hou
authors.forename: Su-Tuen
authors.initials: ST
authors.lastname: Yeh
authors.forename: Chiu-Hsia
authors.initials: CH
authors.lastname: Li
authors.forename: Jiann-Chu
authors.initials: JC
authors.lastname: Chen
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000494:pharmacology*; D000284:Administration, Oral; D000818:Animals; D004032:Diet / Q000662:veterinary; D006358:Hot Temperature; D007101:Immersion; D007113:Immunity, Innate / Q000187:drug effects; D007267:Injections / Q000662:veterinary*; D014442:Monophenol Monooxygenase / Q000378:metabolism; D033561:Penaeidae / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology / Q000382:microbiology*; D010587:Phagocytosis / Q000187:drug effects; D016897:Respiratory Burst / Q000187:drug effects; D000461:Rhodophyta / Q000737:chemistry*; D012623:Seawater; D013482:Superoxide Dismutase / Q000378:metabolism; D016019:Survival Analysis; D044149:Vibrio alginolyticus / Q000276:immunology*; D014867:Water / Q000737:chemistry
chemical_list: D000276:Adjuvants, Immunologic; D014867:Water; D014442:Monophenol Monooxygenase; D013482:Superoxide Dismutase