Dynamic changes in gut microbiota and production phenotypes driven by host genetic background in large yellow croaker

Abstract

The gut microbiota is becoming increasingly important in enhancing aquaculture productivity. However, there are fewer studies on the effect of host genetic background on the gut microbiota of cultured fish. In the current study, we aimed to determine whether the genetic background of large yellow croaker influences differences in gut microbial composition and growth. To address this objective, we conducted a comparative experiment involving the nearshore cage culture of a selected line (SL) of large yellow croaker, which was subjected to genetic selection for swimming performance, alongside a control line (CL). Both lines were reared under identical environmental and dietary conditions for a duration of six weeks. We employed 16S rRNA gene sequencing technology to analyze the gut microbial composition of the large yellow croaker, and utilized bioinformatics methods to assess the abundance and diversity of the gut microbiota. The findings revealed that the core gut microbiota of both lines primarily comprised Proteobacteria, Firmicutes, and Bacteroidetes. However, a significant disparity in gut microbiota abundance was observed between SL and CL following nearshore cage culture. Additionally, the survival rate of SL reached 64.8 %, significantly higher than the 37.3 % observed in CL. The feed conversion efficiency of SL reached 47.7 %, significantly higher than that of CL (28.6 %). These results underscore the influence of host genetic background on driving differences in gut microbial community composition and production phenotypes. This research offers intriguing insights into the interconnectedness of gut microbiota, fish genetics, and production phenotypes.