Integrated gut microbiota and multi-omics analysis revealed the growth differences of female giant freshwater prawn (Macrobrachium rosenbergii).

Macrobrachium rosenbergii (giant freshwater prawn; GFP) holds considerable importance in aquaculture due to its high market demand and economic significance. Female GFP growth varies significantly, however, the processes responsible for these growth disparities remain unknown. In this study, intestinal and hemolymph samples of large (FL), medium (FM), and small (FS) female GFPs were collected to investigate the molecular mechanism of female GFP growth. Through the utilization of 16S rRNA sequencing and liquid chromatography-mass spectrometry metabolomics, significant intestinal flora and metabolites linked to the growth performance of female GFPs were identified. The dominant phyla of the three groups were the same, namely Firmicutes and Proteobacteria. Among groups, small females exhibited the lowest abundance of Proteobacteria (27.26 %) and the highest abundance of Firmicutes (70.10 %). The most abundant genus in each group was Lactococcus. Liquid chromatography-mass spectrometry identified 115 annotated differential metabolites, and essential metabolites related to female GFP growth performance were screened. The concentration of serum metabolites in the larger females exhibited a statistically significant variance compared to that of the smaller females. Through association analysis, we identified key genes, metabolites, and gut microbiota that influence the growth of female GFPs. Likewise, we used multi-omics techniques to establish two relationship models ("gut microbiota-GFP phenotype-metabolite", "gut microbiota-GFP phenotype-transcript"), and three important network association models ("DN5520_c0_g1-CW1-Bacteroides", "DN537746_c0_g1-BW-Roseburia" and "Picolinic acid-phenotype-Roseburia") were further developed. The present study provides novel insights into the mechanisms underlying the variability in individual growth among female GFPs. Our findings offer valuable information for future investigations exploring the correlation between gut flora and host organisms in aquatic environments.