Comparative evaluation of growth performance, flesh quality, and gut microbiota among three strains of largemouth bass (Micropterus salmoides)

A comparative analysis was conducted to compare the growth performance, flesh quality, and gut microbiota of three strains of largemouth bass ( Micropterus salmoides ), Zhelu No.1 (ZL), the Reservoir group (RG), and Youlu No.3 (YL). For this purpose, three strains of largemouth bass raised under identical conditions until they reached 150 days of age. The dorsal muscle of fish was collected and analyzed for the proximate composition, texture properties, free amino acids, volatile organic compounds and ATP-related compounds. Meanwhile, the gut microbiota of different strains was also detected. The results demonstrated that the ZL strain exhibited higher body weight, fat content and condition factor compared to the RG and YL strains. Furthermore, the levels of umami amino acids, total amino acids (TAA), and essential amino acids (EAA) in the ZL strain were significantly higher than those in RG and YL strains. Moreover, HxR and Hx contents in the ZL strain were significantly lower than in the YL strain. GC‑IMS analysis further revealed that ethanol and benzaldehyde levels were higher in the ZL than in the other two strains. Additionally, gut microbiota analysis revealed that the ZL strain was characterized by a community dominated by Stenotrophomonas (60.1 %) and Chryseobacterium (23.6 %), a composition that may contribute to its superior growth performance. In summary, the ZL strain displayed integrated advantages in growth efficiency, flavor profile, and nutritional quality, underscoring its potential as a preferred alternative in largemouth bass aquaculture. • The growth performance, flesh quality, and gut microbiota of largemouth bass were studied. • ZL strain exhibited a higher body weight, fat contents and CF than RG and YL strains. • The umami amino acids, TAA, and EAA in the ZL strain were higher than RG and YL strains. • The ethanol and benzaldehyde levels were higher in the ZL than in the other two strains. • A richer and more balanced gut microbial community was observed in the ZL strain.