Most ciliated protozoa in extreme environments are cryptic in the 'seed-bank'.

Abstract

This study focuses on the species rich- ness of ciliated protozoa in inland saltpans. A low number of ciliates were found thriving under extreme high salinity; however, a diverse assem- blage of ciliate species was revealed by gradually diluting the salt concentration, meaning that most ciliate species in these environments are hidden in the seed bank awaiting favourable growth condi- tions. In some saltpan samples, up to 100 % of the cil- iate species found were retrieved from the seed bank. Our results highlight the importance of ciliate seed banks as repositories of microbial diversity in the natural environment, enabling ecosystems to react to environmental change. The ability of micro- bial communities to respond to a changing environ- ment depends on a large local diversity of rare and encysted species.