Effect of hot-water extract of brown seaweed Sargassum glaucescens via immersion route on immune responses of Fenneropenaeus indicus

Objective: The development of shrimp aquaculture, in spite of its global necessity, is largely at stake as significant ecological and pathological problems are increasing in the vast majority of the shrimp producing countries. Shrimp immunology is a key element in establishing strategies for the control of diseases in shrimp aquaculture. In this study, the effect of hot-water extract of brown seaweed, Sargassum glaucescens, via immersion route on immune responses of Fenneropenaeus indicus is investigated. Method & Materials: The total haemocyte count (THC), differentional haemocyte count (DHC), total plasma protein (TPP), Phagocytic activity (PA), bacterial clearance efficiency (BCE) and bactericidal activity (BE) were examined when the shrimp F. indicus (11.32±1.20 g) were immersed in seawater (39 ppt and 25±1 ○C) containing hot-water extract of brown alga Sargassum glaucescens at 100, 300 and 500 mg/l. Results & Conclusion: The above-mentioned parameters increased significantly (p < 0.05) when the shrimp were immersed in seawater containing hotwater extract at 100 mg/l after 3h and 300 and 500 mg/l after 2 h. F. indicus that were immersed in hot-water extract at 300 and 500 mg/l had increased phagocytic activity and clearance efficiency to Vibrio spp. after 2 hours. But Bactericidal activity increased significantly after 1 hour in same concentrations.

Keywords:

Fenneropenaeus indicus , Sargassum glaucescens , Total haemocyte count , differentional haemocyte count , total plasma protein , phagocytic activity , bacterial clearance efficiency , bactericidal activity