Succession of bacterioplankton community in intensive shrimp (Litopenaeus vannamei) aquaculture systems

Abstract

Bacterioplankton play an integral role in aquaculture systems, but our understanding of the succession of bacterioplankton community along intensive shrimp cultivation is fragmentary. Here we used high-throughput sequencing technique to study the dynamics of bacterioplankton community during the process of intensive shrimp (Litopenaeus vannamei) cultivation, and link community changes to physicochemical and biological factors. Community composition varied dramatically over time, supporting the idea of significant unidirectional temporal change in bacterioplankton assemblages, and could be clustered into 4 seral stages by CLUSTER analysis. Different dominant taxa were identified in different seral stages. Furthermore, we used a RMT-based network method to reveal the interspecies interactions among different bacterioplankton and found that these interactions were also dynamic along bacterioplankton succession. Canonical correspondence analysis and Pearson correlations showed that ammonium, nitrite, dissolved oxygen, cryptophytes and green algae constrained community composition by affecting the relative abundance of susceptible species. Besides, Candidatus Aquiluna rubra was identified as the keystone and generalist of the entire network, suggestive of an important role in driving bacterioplankton succession. These findings expand our understanding of the underlying mechanisms of bacterioplankton succession in ponds with intensive rearing shrimp, and suggest that stabilizing environmental variables (e.g. increasing DO, minimizing nutrient pollution and regulating phytoplankton community) could be a useful management tool for promoting and maintaining healthy aquaculture environments.