Abstract: MiSeq high-throughput sequencing technology was used to investigate the intestinal colony bacterial community structure of Apostichopus japonicus at 10, 16, 21, and 26 ℃. The results showed that bacterial phylotypes in all groups are closely related at phylum level, with Bacteroidetes, Verrucomicrobia, and Proteobacteria being the dominant phyla. The dominant genera in the intestinal tract of sea cucumber were Rubritalea, Lutibacter, and Vibrio. Lutibacter and Vibrio had the largest proportion at 10 ℃, and Rubritalea had the largest proportion at 26 ℃. The proportion of these dominant bacteria in the gut microbiota at different temperatures is different, indicating that there is certain relationship between the intestinal flora of sea cucumber and its growth temperature. Particular bacteria in the intestinal flora of sea cucumber existed at different temperatures. The bacteria in the 10 ℃ group were Luteolibacterand Colwellia, the bacteria in the 21 ℃ group was Coraliomargarita, and in the 26 ℃ group was Photobacterium. The aestivation group had the most endemic bacteria, including Sphingomonas,Aeromonasand Phenylobacterium. Sphingomonas is an animal pathogen and Aeromonas has a certain virulence to sea cucumber, which is associated with low survival rate of sea cucumber at high temperature. Results of COG and KEGG annotation analysis revealed 24 COG functions and 41 KEGG pathways, and their functions belonged to amino acid transport and metabolism, carbohydrate transport and metabolism, and membrane transport. Most of the gut microbial gene functions of sea cucumber are concentrated in amino acid metabolism, carbohydrate metabolism, energy metabolism and substance transport, replication, and repair. These functions are closely related to the growth of sea cucumber. The functional abundance was the lowest at 10 ℃ treatment.

Key words: Changting County, ecological vulnerability, assessment, level index, remote sensing.