effect of hot water extraction of sargassum glaucescens algae in prevention of white spot disease in fenneropenaeus indicus.

in this study brown algae, sargassum glaucescens and that found plenteously in persian gulf and bushehr coast, were collected and hot water extracts of them were lyophilized. f. indicus (11.32±1.20 g), after two weeks adaptation in shoghab research station dependent to iran shrimp research center, isrc, were immersed in seawater (39 ppt and 25±1 c○) containing hot-water extract of brown algae, s.glaucescens, at 100, 300 and 500 mg/l concentration, prevention of white spot disease and immunological parameters (total haemocyte count (thc), total plasma protein (tpp) and phagocytic activity) were examined. according to results, immersion in seawater containing 300 and 500 mg/l concentration of algal hot-water extract after 2 and 3 hours significantly enhanced thc, tpp and phagocytic activity. immersion in seawater containing 100, 300 and 500 mg/l hot-water extract of s.glaucescens after 3 hours, improved the survival rate of wssv-infected f. indicus.