The temporal dynamics of ciliate community structure in a southern Chinese shrimp aquaculture facility were investigated during the period June–September 2012. A total of 53 species belonging to 37 genera and 17 orders were recorded based on analyses of eight samples. Ciliate abundance peaked between 16 August and 14 September 2012, while the maximum number of species occurred on 26 June 2012. Clear temporal patterns were observed in the ciliate community structure. The patterns of succession of the 10 most abundant species were consistent with the results of a Canonical Analysis of Principal coordinates (CAP) analysis. Correlation analyses showed that these patterns of succession were related to temporal changes in environmental variables. In summary, the results demonstrate that the ciliate community responds predictably to environmental variations and recovers from shrimp cultivation.

There is no consensus on the question of whether or not free-living protist species have biogeographies, with the strongest disagreement coming from advocates of the hypothesis that the extraordinary abundance of protists drives their ubiquitous dispersal. If the probability of a species being ubiquitous is a function of its absolute global abundance, then the species that are least likely to be ubiquitous are those with relatively small global populations, i.e. the largest species. Among the free-living ciliated protozoa, a prime candidate for such an organism must be the large (~1200 μm long), unmistakable, fragile, non-encysting karyorelictid Loxodes rex. This ciliate was known only from fresh waters in tropical Africa and it was long considered to be a rare example of an endemic ciliate. Here it is reported that Loxodes rex is thriving in a pond in Thailand. The status of other alleged endemic ciliate species is discussed.