Environmental dispersal and host priority effect alternatively dominate intestinal microbiota succession of cultured shrimp along with host development.

Unlabelled: Given the importance of the intestinal microbiota in life-long health, increasing attention has been paid to ecological mechanisms that govern microbial succession. Both environmental dispersal and host priority effect play important roles in intestinal microbiota succession of aquatic animals, but their relative importance is unknown. Here, we explore the intestinal microbiota succession and assembly of across larvae, postlarvae, juvenile, and preadult stages. We aimed to clarify the relative contributions between environmental dispersal and host priority effect on intestinal microbiota succession. We found that both α- and β-diversity of the intestinal microbiota changed dynamically along with host development. In particular, the intestinal microbiota assemblies were dominated by stochastic processes, except with the larvae stage. The succession of shrimp intestinal microbiota was clearly influenced by internal communities in the intestines of larvae, as well as the external communities in water and sediment. Importantly, the impact of environmental dispersal on the intestinal microbiota succession outweighed the host priority effect during the larvae and postlarvae stages. However, this situation was largely reversed during the juvenile and preadult stages. The possible reason is that, during the larvae and postlarvae stages, shrimp mainly feed on plankton from the environment, and their digestive system remains underdeveloped, the host recruits numerous microbes from the environment and selects specific microbes to aid digestion and nutrient absorption. These findings enhance our understanding of alternate effects of environmental and host factors on the intestinal microbiota succession of aquatic animals and provide a foundation for developing microecological management strategies in shrimp culture.

Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-024-00236-y.