Stentor amethystinus ciliate. Light microscope darkfield illumination footage of the large peritrich ciliate Stentor amethystinus, attached to a detritus particle. This sessile microscopic organism is found in water, attached to debris or other plants and animals by a stalk. Stentor ciliates are filter organisms, using rows of cilia and an undulating membrane to create a current in the water to direct food particles towards the buccal cavity (mouth opening). This ciliate can retract its contractile stalk very fast if disturbed. This ciliate retracts at the end of this clip. Magnification: x50 at 10 centimetres across.