Abstract: Semisulcospira gredleri, Viviparus tricinctus and Sinotaia limnophila are all important economic freshwater snail species, which play significant ecological roles in the restoration of water ecology. The gut microbes of aquatic animals play a crucial role in food digestion and nutrient absorption. Therefore, in this study, 16S rDNA high-throughput sequencing was use to compare the composition and function of gut microbiota in three species of freshwater snails from the Lijiang River. The results showed that at the phylum level, the common dominant microorganisms in the three groups were Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria. Proteobacteria was the most abundant bacteria in both groups. At the genus level, the common dominant bacteria were Aeromonas, Acinetobacter, Pseudomonas. In terms of community diversity, there was no significant difference between Semisulcospira gredleri and Viviparus tricinctus (P>0.05), while there was a highly significant difference between Sinotaia limnophila and both Semisulcospira gredleri and Viviparus tricinctus (P<0.01). Based on PICRUSt analysis, the intestinal microbiota of three species of snails was predicted to be mainly involved in metabolic processes, including amino acid metabolism, metabolism of cofactors and vitamins, xenobiotics biodegradation and metabolism, metabolism of terpenoids and polyketides, lipid metabolism, metabolism of other amino acids.

Key words: intestinal flora, 16S rDNA, high-throughput sequencing, freshwater snail, functional prediction