Impact of Dietary Administration of Seaweed Polysaccharide on Growth, Microbial Abundance, and Growth and Immune-Related Genes Expression of The Pacific Whiteleg Shrimp (Litopenaeus vannamei)

Eman M Abbas; Ahmed Said Al-Souti; Zaki Z Sharawy; Ehab El-Haroun; Mohamed Ashour

doi:10.3390/life13020344

Impact of Dietary Administration of Seaweed Polysaccharide on Growth, Microbial Abundance, and Growth and Immune-Related Genes Expression of The Pacific Whiteleg Shrimp (Litopenaeus vannamei)

Life (Basel). 2023 Jan 27;13(2):344. doi: 10.3390/life13020344.

Authors

Eman M Abbas¹, Ahmed Said Al-Souti², Zaki Z Sharawy¹, Ehab El-Haroun³, Mohamed Ashour¹

Affiliations

¹ National Institute of Oceanography and Fisheries (NIOF), Cairo 11516, Egypt.
² Head AL Hail Aquaculture Unit, Department of Marine Science and Fisheries, College of Agriculture and Marine Science, Sultan Qaboos University, Muscat 123, Oman.
³ Fish Nutrition Research Laboratory, Animal Production Department, Faculty of Agriculture, Cairo University, Cairo 11562, Egypt.

Abstract

This work aims to determine the impact of dietary supplementation of polysaccharide, extracted from brown seaweeds Sargassum dentifolium on growth indices, feed utilization, biochemical compositions, microbial abundance, expressions of growth and immunity-related genes, and stress genes of the Pacific Whiteleg shrimp Litopenaeus vannamei. A total of 360 post-larvae of L. vannamei were randomly distributed into a 12-glass aquarium (40 L of each) at a stocking density of 30 shrimp with an initial weight of (0.0017 ± 0.001 g). During the 90-day experiment trial, all shrimp larvae were fed their respective diets at 10% of total body weight, three times a day. Three experimental diets were prepared with different seaweed polysaccharide (SWP) levels. The basal control diet had no polysaccharide level (SWP₀), while SWP₁, SWP₂, and SWP₃ contained polysaccharides at concentrations of 1, 2, and 3 g kg^-1 diet, respectively. Diets supplemented with polysaccharide levels showed significant improvements in weight gain and survival rate, compared to the control diet. Whole-body biochemical composition and the microbial abundance (the total count of heterotrophic bacteria and Vibrio spp.) of L. vannamei showed significant differences among polysaccharide-treated diets compared to the control. At the end of the feeding experiment, the dietary supplementation of polysaccharide levels enhanced the expression of growth-related genes (Insulin-like growth factors (IGF-I, IGF-II), immune-related genes (β -Glucan-binding protein (β-Bgp), Prophenoloxidase (ProPO), Lysozyme (Lys), and Crustin), and stress genes (Superoxide dismutase (SOD) and Glutathione peroxidase (GPx) in the muscle tissue of L. vannamei. However, the current study concluded that the inclusion rate of 2 g kg^-1 of polysaccharide as a dietary additive administration enhanced both weight gain and survival rate of L. vannamei, while the incorporation level of 3 g kg^-1 reduces the abundance of pathogenic microbes and enhances the growth-, immunity- and stress-related gene expressions of L. vannamei.

Keywords: Sargassum dentifolium; feed additives; growth performances; growth-related genes; immune-related genes; shrimp industry; stress genes.

Grants and funding

Hail Aquaculture Unit, Department of Marine Science and Fisheries, College of Agriculture and Marine Science, Sultan Qaboos University, Oman./Sultan Qaboos University