Oral Administration of Alginate From A Tropical Brown Seaweed, Sargassum sp. To Enhance Non-Spesific Defense In Walking Catfish (Clarias sp.)

Abstract

Alginate that is usually extracted from brown seaweeds, is a bioactive substance with immunomodulator activity. The purpose of this research was to evaluate the effect of oral administration of alginate on the non-specific immune system of walking catfish ( Clarias sp.). An experiment was conducted in a Completely Randomized Design with five treatments in triplicates. Alginate was supplemented in feed at doses of 0 (control treatment), 2, 4, 6 and 8 g/kg of feed. The walking catfish was fed twice daily at feeding rate of 5%. Non-specific defense parameters evaluated were Nitroblue Tetrazolium (NBT) activity, phagocytic activity (PA), phagocytic index (PI), leukocyte differentiation, hematocrit and leucocrit. The parameters were observed prior to be treated, 5 th , 10 th and 15 th days after treatments. Oral administration of alginate at 4 g/kg of feed increased NBT and PA activities significantly ( P <0.05) in 5 days, while alginate at a dose of 6 g/kg increased NBT activity and monocyte percentage significantly ( P <0.05) in 5 days. These results suggested that oral administration of alginate at 4 g/kg effectively increased non-specific immune system of walking catfish.