Chilomastix mesnili

Chilomastix mesnili. Trophozoite and cyst in fecal smear (trichrome stain, oil immersion). A larger trophozoite and a smaller cyst are seen side by side. The trophozoite has the typical pyriform shape and a nucleus with a large, central karyosome. The cyst is more rounded than lemon-shaped and the karyosome is seen in the nucleus. Trophozoites typically take a more delicate stain, whereas cysts often are more darkly stained, as is seen here.