Feed Additives Impacts on Shellfish Microbiota, Health, and Development

Abstract

Aquaculture industries have received extensive attention and undergone rapid expansion worldwide. Based on FAO statistics, the majority of aquaculture production among different continents takes place in Asian countries, which contribute 90% of worldwide aquaculture production. Intensification of aquaculture practices has often caused diseases to occur, which forces farmers to use chemicals extensively. The overuse or continuous use of antibiotics in aquaculture sanitary management has resulted in the emergence of drug-resistant genes and multiple antibiotic resistance (MAR) bacteria in the aquatic environment of fish and shellfish. During the past decade, numerous studies have considered application of different environmentally friendly feed additives as an alternative to antibiotics in shellfish aquaculture. According to the available literature, functional feed additives including pro-, pre-, and synbiotic are capable of improving digestive function, the utilisation of dietary ingredients, and shellfish performance. Also, numerous reports have shown that functional feed additives can regulate microbial community composition and modulate microbial balance, which will inhibit pathogens, and modulate host immune response to exert beneficial effects on aquatic animals. The present chapter of this book summarizes and discusses the available literature regarding possible effects of pro-, pre-, and synbiotics on shellfish growth performance, development, and immune parameters with special focus on mode of action. Also, areas of research that need more attention in future have been highlighted.