Objective The study aims to analyze the effects of different feeding frequencies on growth performance of largemouth bass (Micropterus salmoides), culture water quality and bacterial community structure under land-based round drum.

Methods This study conducted experiments with two feeding frequencies: 2 times/day and 3 times/day.

Results The results showed that the final body mass and specific growth rate of the group fed 3 times/day were higher than those of the group fed 2 times/day. Feeding frequency had a significant impact on the levels of ammonia nitrogen (TAN), nitrite (NO₂-N), suspended solids (SS), and chemical oxygen demand (COD) in the water (P<0.05), with the group fed 2 times/day having higher levels than the group fed 3 times/day. The bacterial community structure of the culture water was similar in both groups, with the dominant phyla being Proteobacteria and Bacteroidetes, and the dominant genera being Plesiomonas and Rhodobacter. Statistical analysis of the abundance of common pathogenic bacteria during the culture process of largemouth bass revealed that the average abundance of Aeromonas caviae in the 3 times/day group (0.08%) was significantly lower than that in the 2 times/day group (0.14%) (P<0.05). The results of the correlation analysis between environmental factors and bacterial community structure showed that TAN, total nitrogen (TN), and total phosphorus (TP) had a significant impact on the bacterial community structure of the water (P<0.05).

Conclusion Based on the aforementioned findings, within the context of a land-based round barrel culture model for M. salmoides, a feeding frequency of 3 times/day has advantages over 2 times/day. These benefits include accelerated growth rates of the bass, reduced levels of critical water quality parameters in the culture medium, and diminished abundance of pathogenic bacterial populations. The research outcomes furnish tangible support for the scientific feeding practices of M. salmoides within land-based round barrel culture systems.