Close up of a Stentor, a large freshwater ciliate, as it uses cilia lining its mouth to pull itself through water. Its macronucleus appears as a string of beads. Other structures include food vacuoles and contractile vacuoles. This protozoan can be found in lakes, ponds and streams throughout much of the world. It's bluish-green color comes from the pigment, stentorin, found in its body. Stentors typically range up to 1,000 microns in length. Recorded under Nomarski DIC.