isotricha isotricha isotricha is a genus of protozoa (single-celled organisms) which are commensals of the rumen of ruminant animals. they are approximately 150 μm (0.0059 in) long. isotricha isotricha intestinalis scientific classification domain: eukaryota clade: diaphoretickes clade: sar clade: alveolata phylum: ciliophora class: litostomatea order: vestibuliferida family: isotrichidae genus: isotrichastein 1859 species include: isotricha intestinalis stein 1858 isotricha prostoma stein 1858