Abstract: Based on the MiSeq high-throughput sequencing technology, we investigated the structure, α-diversity and function of bacterial community in the intestinal tracts and culture environment of the sea cucumbers (Apostichopus japonicus)  in autumn. The sea cucumbers were cultured in the ponds of the Yellow Sea and Bohai Sea. The results showed that the Chao1 and ACE indices of bacterial community in the bottom sediments of the Yellow Sea and the Bohai Sea were rela-tively high, indicating that the bacterial community in the bottom sediments of the culture ponds was abundant. The dominant bacterial phylum was Proteobacteria (with a proportion of >43.25%) in the intestine of sea cucumbers, pond sediments, and seawater of the Yellow Sea and Bohai Sea. Halioglobus (with a proportion of >12.67%) was the dominant bacterial genus in the intestine of the sea cucumbers in both sea areas. There were differences in the dominant genera in the culture environment. The dominant genus was Roseibacillus (13.59%) in the aquaculture water of the Yellow Sea and Marivita (21.33%) in that of the Bohai Sea. In the aquaculture sediments, the dominant genus was Desulfopila (>9.26%) in Yellow Sea and Thioprofundum (3.79%) in Bohai Sea. In addition, special species belonging to genera Marivita, Ascidiaceihabitans and Aliivibrio were found in the Bohai Sea and accounted for a large proportion. COG and KEGG annotation analysis revealed 24 COG functional groups (primarily serving functions such as amino acid transport and metabolism), and 41 KEGG pathways (mainly representing amino acid transport and metabolism, carbohydrate metabolism, and membrane transport). Our results provide scientific basis for healthy aquaculture of sea cucumber and disease prevention.

Key words: tiankeng, plant community, species diversity, talus