Temporal patterns of bacterial communities in shrimp (Litopenaeus vannamei) culture systems loaded with oyster shells

Abstract

Oyster (Crassostrea gigas) shell-loading in aquaculture systems can regulate water quality, a critical factor for Litopenaeus vannamei growth. However, the effects of oyster shell-loading on the bacterial community composition and their interactions during shrimp culture processes remain elusive. Here, 16S rRNA gene amplicon sequencing was used to investigate the dynamics and co-occurrence patterns of bacterial communities in L. vannamei culture systems loaded with oyster shells. The results indicated that oyster shell-loading significantly improved both shrimp survival and water quality. Oyster shell-loading was found to cause a significant increase in the relative abundance of Alphaproteobacteria (P < .05), whereas the relative abundances of Actinobacteria, Deltaproteobacteria, and Cyanobacteria decreased significantly. Mantel test and partial least squares path modeling analysis revealed that oyster shell-loading was closely related to changes of water variables, especially total ammonia nitrogen (TAN) and chlorophyll-a; water temperature and salinity were the most important physical factors driving bacterial community variation. The co-occurrence networks in the control and oyster shell-loading groups were mainly occupied by Flavobacteriaceae and Rhodobacteraceae, and more complex microbial interactions were found in the oyster shell-loading group. This study is the first report on the effects of oyster shell-loading on bacterial community dynamics and co-occurrence patterns in aquaculture systems. These findings are important steps towards clarifying the biological mechanisms of oyster shell-loading on shrimp growth.