Effects of Padina australis (Hauck) polysaccharide extract on growth, antioxidant and nonspecific immune parameters of the western white leg shrimp, Litopenaeus vannamei (Boone)

This study aimed at determining impacts of various amounts of watersoluble polysaccharide extracts from brown algae, Padina australis (Hauck) (WPP) on actions of antioxidant enzymes, the growth, and nonspecific immune response of shrimp, Litopenaeus vannamei (Boone). Triplicate groups of shrimp (1 ±0.1g) have been given feed 4 isonitrogenous and isolipidic diets composing of 4 levels; that is, 0 (control), 0.5, 1.0, and 1.5 g kg1 of WPP extract for eight weeks. Analyses showed that significantly positive effects of diets with 1.0 g kg1 of WPP extract on the growth function of the studied groups. Additionally, improvements of the antioxidant enzyme activities, such as catalase, malondialdehyde, superoxide dismutase, and glutathione peroxidase via feeding 0.5 and 1 g kg1 of WPP extracts. Furthermore, activity of phenoloxidase and lysozyme in the treatment fed by 0.5 and 1 g kg1 of WPP extract have been considerably greater in comparison to the controls and 1.5 g kg1 treatments. Findings demonstrated that usage of 1.0 g kg1 of water soluble polysaccharides extract of the P. australis are useful on growth function, antioxidant and non0specific immune variables of the L. vannamei.