tetrahymena pyriformis tetrahymena pyriformis tetrahymena pyriformis is a species of ciliophora in the family tetrahymenidae. tetrahymena pyriformis scientific classification domain: eukaryota clade: diaphoretickes clade: sar clade: alveolata phylum: ciliophora class: oligohymenophorea order: hymenostomatida family: tetrahymenidae genus: tetrahymena species: t. pyriformis binomial name tetrahymena pyriformis(ehrenberg, 1830) furgason, 1940 synonyms colpoda pirum müller, 1786 kolpoda pirum müller, 1786 leucophrys pyriformis ehrenberg, 1830 saprophilus oviformis kahl, 1926 sathrophilus oviformis tetrahymena geleii furgason, 1940 tetrahymena pyriformis-komplex trichoda pyrum ehrenberg, 1830 it is one of the most commonly ciliated model used for laboratory research. the species is widely distributed. it lives in fresh water like springs, ditches, creeks, ponds, and lakes.: 3