Association of intestinal fungal communities with the body vesicular syndrome: An emerging disease of sea cucumber (Apostichopus japonicus)

Diseases during aquaculture can limit the growth and survival of sea cucumber (Apostichopus japonicus), one of the most valuable aquaculture species in China. Recently, a novel disease, named body vesicular syndrome (BVS), has been frequently observed, resulting in the blister, lysis, and rupture of A. japonicus after boiling. Information regarding BVS in A. japonicus, however, has not been addressed. In the present study, the intestinal fungal communities from healthy and BVS A. japonicus were measured by the high-throughput sequencing technology. Significant higher richness and diversity were observed from the intestinal fungal communities of BVS A. japonicus compared to the healthy controls. Moreover, the results of principal coordinate analysis and PERMANOVA revealed that the composition structures of intestinal fungal communities were significantly changed in the A. japonicus with BVS. Further abundance difference analyses were conducted for both the composition and predicted functions of the intestinal fungal communities between the healthy and BVS A. japonicus. The results showed that the classes of Tremelloycetes and Eurotiomycetes were enriched in the intestines of A. japonicus with BVS. Meanwhile, the abundances of animal pathogen and fungal parasite were also significantly enhanced in the intestines of BVS A. japonicus. Overall, the results of our study illustrated the associations of BVS and intestinal fungal communities in A. japonicus and expanded our understanding of this disease. •A novel disease of sea cucumber named body vesicular syndrome (BVS) was investigated.•The diversity of intestinal fungal communities was increased in sea cucumbers with BVS.•The intestinal fungal community compositions were changed in the BVS sea cucumbers.•Enhanced pathogenic fungi and parasites were observed in sea cucumbers with BVS.