Tetrahymena

Tetrahymena
Tetrahymena thermophila
Scientific classification
Domain: Eukaryota
Clade: Diaphoretickes
Clade: Sar
Clade: Alveolata
Phylum: Ciliophora
Class: Oligohymenophorea
Order: Hymenostomatida
Family: Tetrahymenidae
Genus: Tetrahymena

Tetrahymena is a genus of free-living ciliates, examples of unicellular eukaryotes. The genus Tetrahymena is the most widely studied member of its phylum.:59 It can produce, store and react with different types of hormones. Tetrahymena cells can recognize both related and hostile cells.

They can also switch from commensalistic to pathogenic modes of survival. They are common in freshwater lakes, ponds, and streams.:277

Tetrahymena species used as model organisms in biomedical research are T. thermophila and T. pyriformis.