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

 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 controlling diseases in shrimp aquaculture. The total haemocyte count (THC), differential haemocyte count (DHC), total plasma protein (TPP), Phagocytic activity (PA), bacterial clearance efficiency (BCE) and bactericidal activity (BE) were examined when the F. indicus shrimps (۱۱.۳۲±۱.۲۰ g) were immersed in seawater (۳۹ ppt and ۲۵ ± ۱ ○C) containing hot-water extracts of brown alga Sargassum glaucescens at ۱۰۰, ۳۰۰ and ۵۰۰ mg/l. These parameters increased significantly (p < ۰.۰۵) when the shrimp were immersed in seawater containing hot-water extracts at ۱۰۰ mg/l after ۳h and ۳۰۰ and ۵۰۰ mg/l after ۲ h. F. indicus shrimps that were immersed in hot-water extracts at ۳۰۰ and ۵۰۰ mg/l had increased phagocytic activity and clearance efficiency to Vibrio spp. after ۲ hours. But bactericidal activity increased significantly after ۱ hour in the same concentrations.

Keywords:

Fenneropenaeus indicus , Sargassum glaucescens , Total haemocyte count , Differential haemocyte count , Total plasma protein , Phagocytic activity , Bacterial clearance efficiency