Comparative study of the intestinal microbial community of wild and cultured kaluga sturgeon,Huso dauricus

The kaluga, Huso dauricus (Georgi 1775), is a large‐sized semi‐anadromous sturgeon native to the Amur River basin. Gut microbes play an important role in the growth and development of fish. Because wild samples of this species are difficult to obtain, very few studies have analysed the microbial community of the kaluga gut. Here, we used high‐throughput sequencing to determine differences in the intestinal microbial communities of wild and cultured kaluga, to lay the foundation for development of micro‐ecological preparations that might ultimately assist with conserving wild kaluga by benefitting sturgeon aquaculture. Two 2‐year‐old (wild) fish collected from the Heilongjiang River basin were size‐ and age‐matched with two 2‐year‐old (cultured) fish obtained from a breeding base in Yunnan Province, for molecular analysis of gut samples. In total, 483,008 16S rRNA sequences were obtained. The intestinal microbial diversity was greater in the wild kaluga than in the cultured fish. The dominant phyla in the gut community of wild kaluga were Proteobacteria (47.9%), Fusobacteria (30.5%) and Firmicutes (8.85%), whereas samples from the cultured kaluga were dominated by Fusobacteria (78%). This result may be attributed to differences in environmental conditions, particularly water quality and temperature, as well as diet between the wild and cultured animals. The findings provide basic data to assist further research and the development of feed as a part of artificial breeding technology.