Comparative insights into digestive, antioxidant, and immune traits and microbial composition between wild-caught and pond-reared megalopa populations of Chinese mitten crab (Eriocheir sinensis)
摘要
Although the Yangtze wild megalopa (WM) of Eriocheir sinensis generally have the worse culture performance than the pond-reared megalopa (PM) during the juvenile culture stage, the underlying reason for those differences remains unknown due to several environmental differences between two megalopa sources. In this study, we compared the activities of digestive, antioxidant, and immune enzyme, as well as microbial composition of WM and PM from the Yangtze basin. Additionally, the microbial composition of their living water was analyzed. The results showed that PM exhibited significantly higher activities of trypsin, lipase, total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), and alkaline phosphatase (AKP) than WM (P < 0.05). Regarding microbial composition, non-metric multidimensional scaling (nMDS) analysis revealed that microbiota from the two megalopa sources and their respective living water clearly separated into four groups, suggesting that megalopas possess more specific microbial communities compared to water. Both WM and PM were enriched with Proteobacteria; however, PM exhibited a higher abundance of Bacteroidota than WM. Furthermore, PM had higher relative abundance of Albimonas and Flavobacterium, but Burkholderia-Caballeronia-Paraburkholderia in WM. Regarding the water microbiota, pond-reared water (PW) exhibited higher abundance of Bacteroidota and lower abundance of Proteobacteria than the wild water (WW). The CL500-29 marine group displayed higher relative abundance in WW, but Flavobacteriaceae in PW. These findings suggest that pond-reared megalopa exhibited higher digestive enzyme activities, antioxidant capacity, and immunity than Yangtze wild megalopa, potentially attributable to differences in microbial composition.