Tetrahymena (tet-ra-high-men-a) is an oligohymenophoran ciliate. There are cilia in about 20 kineties (rows) over the body and which are used for cell locomotion. There is also a group of three membranelles and an undulating membrane around the cytostome (upper left), and these are the buccal or oral cilia and are used in food capture. In nature often associated with damaged animals or dead tissue, may eat bacteria. Widely used in laboratory studies, and axenic (bacteria-free) cultures are maintained within high protein medium. This cell is slightly compressed. Phase contrast.