Abstract:  

 The dynamic changes and diversity of ammonia-oxidizing archaeal communities in two kind of ponds (M1: pond with sanded around and netted bottom, M2: traditional soil pond) of Portunus trituberculatus-exopalaemon carinicauda polyculture in different seasons were investigated by terminal restriction fragment length polymorphism (T-RFLP) analysis based on ammonia-oxidizing amoA gene. The results showed that ClusterNitrosopumilus was dominant in both M1 and M2. The community structure of ammonia-oxidizing archaea in aquaculture water changed dramatically during the breeding time. The diversity index and the evenness index of ammonia-oxidizing archaea were the lowest in August and September in both M1 and M2, which indicated that the environment was fragile in this period. RDA analysis showed that the distribution of ammonia-oxidizing archaea in pond water was greatly influenced by ammonium nitrogen in August and September. The result of T-RFLP showed that the community of ammonia-oxidizing archaea was different in M1 and M2 during the farming time and changed differently in each pond. Compared to M1, the community succession of ammonia-oxidizing archaea over time was larger in M2, indicated the community of ammonia-oxidizing archaea was more stable in M1. As such, the improvement of pond sediment could reduce the community shift of ammonia-oxidizing archaea by season.