Stentor swimming

Stentor are a genus of filter-feeding, heterotrophic ciliate protozoa, representative of the heterotrichs. The body is generally horn-shaped, hence the association with the Greek herald and the former name "trumpet animalcule", with a ring of prominent cilia around the anterior "bell" that sweep in food and aid in swimming. Stentor are very common in freshwater lakes and streams, usually attached to algae and other detritus. Some reach several millimeters in length, making them among the largest single celled organisms.