Ciliates — Phylum Ciliophora
Ciliates move by means of rows of beating cilia. The rhythmic movements of their cilia also function to direct food towards the oral region where it is packed into a food vacuole for enzymatic digestion. Species of the genus Paramecium, which are widely distributed from the High Arctic to the Antarctic, are often used as the typical protozoan model. However, unlike other protozoans, Paramecium and other ciliates have two types of nuclei. The macronucleus is responsible for directing the production of enzymes and other molecules needed to sustain growth, while the micronucleus produces the gametic nuclei during conjugation. Ciliates are found in both marine and freshwater environments.