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 water-soluble poly-saccharide extracts from brown algae, Padina australis (Hauck) (WPP) on actions of anti-oxidant enzymes, the growth, and non-specific immune response of shrimp, Litopenaeus vannamei (Boone). Triplicate groups of shrimp (1 ± 0.1g) have been given feed 4 iso-nitrogenous and iso-lipidic diets composing of 4 levels; that is, 0 (control), 0.5, 1.0, and 1.5 g kg-1 of WPP extract for eight weeks. Analyses showed that significantly positive effects of diets with 1.0 g kg-1 of WPP extract on the growth function of the studied groups. Additionally, improvements of the anti-oxidant enzyme activities, such as catalase, malondialdehyde, super-oxide dismutase, and glutathione peroxidase via feeding 0.5 and 1 g kg-1 of WPP extracts. Furthermore, activity of phenoloxidase and lysozyme in the treatment fed by 0.5 and 1 g kg-1 of WPP extract have been considerably greater in comparison to the controls and 1.5 g kg-1 treatments. Findings demonstrated that usage of 1.0 g kg-1 of water soluble poly-saccharides extract of the P. australis are useful on growth function, antio-xidant and non0specific immune variables of the L. vannamei.