Host development promotes the early microbiota succession of teleost surpassing dietary management

Abstract

The bacterial colonization of newly hatched fish is important for larval development and health. Still, there remains a lack of understanding regarding the early microbiota development in Seriola dumerili. In the present study, 16S rDNA sequencing was utilized to analyze the microbiota of S. dumerili larvae and their diets at various developmental stages. Proteobacteria emerged as the dominant phylum in larvae, exhibiting a “U”-shaped peak at DPH14. Conversely, Bacteroidetes, Firmicutes, and Cyanobacteria showed contrasting patterns over time. Alpha diversity followed a hump-shaped pattern, reaching its peak at DPH4, and subsequently declining to its lowest point at DPH30. Although the microbial community of diets was distinct to the larvae, limited impacts were displayed through the richness, diversity of microbial community, and correlation between diets and fish microbiota. Furthermore, these influences shifted with the fish development. The Neutral Community Model (NCM) explained the presence of a neutral process in the assembly of fish communities, but with the influence of random processes gradually diminishing as individual development progressed. These results indicated that diets do affect the fish microbiota assembly and succession, but not the critical driving factors.