Abstract:The dynamic changes and diversity of archaeal communities in two kinds of ponds (M1: the pond with sanded walls and netted bottom; M2: the traditional pond with soil) for the polyculture of Portunus trituberculatus-Exopalaemon carinicauda in different seasons were investigated. The study was conducted with a combination of cloning/sequencing and terminal restriction fragment length polymorphism (T-RFLP) analysis based on archaeal 16S ribosomal RNA. Physicochemical characters of the sea water were monitored at the same time to examine the relationship between environmental factors and archaeal communities. The results showed that the archaeal communities in both M1 and M2 were composed of Crenarchaeota and Euryarchaeota. Halobacteriales and thermoplasamatales in Euryarchaeota were the majority accounting for nearly half of the entire sample. Halobacteriales was more abundant than thermoplasamatales, however, it was the marked alteration in the relative abundance of thermoplasamatales that primarily led to the archaeal community shift. The structure of archaeal community in aquaculture water changed dramatically during the culture. The archaeal communities of M1 and M2 were similar at the beginning of the culture, but changed significantly over time. Principal component analysis showed that the variation in M2 was larger than in M1, which indicated the lower stability of archaeal community in the former. Redundancy analysis indicated that 84.2% of the archaeal community in M1 could be explained by the 9 factors measured in this study, while that M2 was also determined by other factors and only 35.7% was explained. The improvement of pond sediment could reduce the extent of changes in the archaeal community. Correlation analysis showed that the higher the diversity index was, the smaller the influence of environment on the distribution of archaea. In general, the distribution of archaea in pond water changed over seasons, and was greatly affected by temperature, dissolved oxygen, total nitrogen, and total phosphorus
