Natural populations and inbred strains of Tetrahymena

Tetrahymena typically is found in freshwater lakes, ponds, and streams in association with submerged or emergent vegetation. The genus consists of numerous breeding species with micronuclei and many asexual species without micronuclei. In summer months when most populations are at their peak, 30-50% of water samples may yield one or more species of Tetrahymena. This chapter describes both bulk and trapping procedures for collecting Tetrahymena and also evaluates barcode methods for species identification. The history and inbreeding of the laboratory model Tetrahymena thermophila is also discussed. There are numerous unresolved questions about Tetrahymena evolution and biogeography that may be solved by additional collecting.