Effects of fucoidan polysaccharide extracted from seaweed Cystoseira trinodis (C. Agardh, 1820) on immune responses of vannamei shrimp Litopenaeus vannamei (Boone, 1931)

The present study was performed in order to use the seaweed of the Persian Gulf (brown algae Cystoseira trinodis) and also the extraction of fucoidan polysaccharide as an immunostimulant supplementation to improve and enhance some immune parameters of vannamei shrimp. Therefore, 500 shrimp with average weight of 8g were divided into four treatments in triplicate (12 tanks) in a completely randomized design and were fed with diets containing 0, 0.1, 0.2 and 0.4% of fucoidan for 30 days. Results showed a significant effect of fucoidan treatments on the measured parameters (P<0.05). The immune parameters including the number of hyaline, granular and total homocyte cells, superoxide anion, phenoloxidase, superoxide dismutase, catalase and glutathione peroxidase activities in the groups fed with diets containing different levels of fucoidan, especially 0.4% indicated a significant increase compared to the control (P<0.05), while the amount of malondialdehyde showed a significant decrease compared to the control (P<0.05). In general, according to the results of the present study, it can be stated that fucoidan extracted from brown algae Cystoseira trinodis had better performance on improve immune parameters. Therefore, this bioactive compound can be recommended as an immunostimulant in the diet of white leg shrimp.