Effects of different aquaculture models on muscle quality, antioxidant status and gut microbiota of Channa argus

To address the issues such as low resource utilization efficiency and difficult tail water treatment in traditional pond aquaculture models, we evaluated the effects of the freshwater pond-embedded containerized recirculating aquaculture system (Group T) and traditional pond culture (Group P) on the breeding performance of Channa argus. We sampled on the 60^th and 120^th days of the culture period and compared the growth performance, muscle nutritional composition, serum antioxidant indicators, and intestinal microbiota structure and function between the two groups. Compared with Group P, Group T showed significantly higher final body mass, body mass gain rate, and specific growth rate (p<0.05). Muscle crude protein content increased significantly, while crude fat content decreased significantly (p<0.05), with no significant difference in amino acid composition (p>0.05). In terms of antioxidant capacity, the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in serum were significantly higher in Group T than those in Group P (p<0.05), and malondialdehyde (MDA) contents decreased significantly over the culture period, indicating no induction of persistent oxidative stress by the system. Intestinal microbiota analysis reveals that, at the early culture stage, microbial richness (ACE and Chao1 indexes) was lower in Group T than that in Group P, but the Shannon index was significantly higher (p<0.05). At phylum level, Firmicutes, Proteobacteria, and Fusobacteriota were the dominant phyla. At genus level, Clostridium_sensu_stricto_1, Cetobacterium, and Brevibacillus were the dominant genera. LEfSe analysis identified three phyla and eight genera with significant differences (LDA score>4.0, p<0.05). KEGG functional prediction indicates that differential pathways were primarily enriched in level-1 functional categories such as metabolism and genetic information processing. The results demonstrate that the containerized recirculating aquaculture system effectively enhances growth performance and muscle quality, improves antioxidant capacity, and regulates intestinal microbiota structure and metabolic function in C. argus, providing a theoretical basis and practical reference for promoting this green aquaculture model.