Raw data for article "Immunoprotective effects of dietary fucoidan and laminarin on juvenile blunt snout bream (Megalobrama amblycephala)"

Bacterial diseases occur frequently in freshwater aquaculture in China, highlighting the need for green immune preparations. Fucoidan and laminarin are commonly used feed additives in livestock and poultry industries, however, their application in freshwater aquaculture remains limited. Fucoidan and laminarin were used as feed additives for juvenile Megalobrama amblycephala with the supplementation levels of 0.5% and 2.0% for 8 weeks. Aeromonas hydrophila infectionassays were conducted, cumulative mortality rates and tissue bacterial loads were measured, and non-specific immunoassays were performed. Dietary supplementation with 2% fucoidan significantly improved the growth performance and feed utilization of juvenile M. amblycephala, while 0.5% fucoidan and 2% laminarin groups only enhanced feed utilization. After A. hydrophila infection, cumulative mortality rates for the control, 0.5% and 2% fucoidan, and 0.5% and 2% laminarin groups were 76.67%, 67.78%, 57.78%, 62.22%, and 58.89%, respectively. Both supplements increased post-infection survival, reduced tissue bacterial loads, and enhanced host bactericidal and antioxidative abilities by elevating hepatic antimicrobial and antioxidant enzyme activity. Innate immunity of juvenile M. amblycephala was improved by regulation of immune-related gene and protein expression levels. Both additives demonstrated significant immunoprotective effects, markedly reducing mortality and tissue bacterial loadsupon infection. The study provides a theoretical foundation for developing green immunostimulants and antibiotic alternatives for bacterial diseases in fish.