Metagenomic Sequencing Elucidated the Microbial Diversity of Rearing Water Environments for Sichuan Taimen ( Hucho bleekeri )

Sichuan taimen ( ) is a fish species endemic to China's upper Yangtze River drainage and has significant value as an aquatic resource. It was listed as a first-class state-protected wild animal by the Chinese government due to its very limited distribution and wild population at present. To elucidate the diversity of microorganisms in rearing water environments for , metagenomic sequencing was applied to water samples from the Maerkang and Jiguanshan fish farms, where were reared. The results revealed that Pseudomonadota was the dominant phylum in the microbial communities of the water samples. Among the shared bacterial groups, Cyanobacteriota, Actinomycetota, Planctomycetota, Nitrospirota, and Verrucomicrobiota were significantly enriched in the water environment of Jiguanshan ( < 0.01), while Bacteroidota was more enriched in that of Maerkang ( < 0.01). Additionally, the Shannon diversity and Simpson index of the microbial community in the water environment of Maerkang were lower than in that of Jiguanshan. The present study demonstrated the similarities and differences in the microbial compositions of rearing water environments for , which are expected to benefit the artificial breeding of in the future.