The ciliates rank among the most important groups of protists. There are an estimated 8,000 species of Ciliophora. Some of the major species of Ciliophora include Paramecium, Didinium, Suctoria, Stentor, and Vorticella. 
Ciliophora acquired their name from by their means of locomotion, they swim using cilia. Cilia are short, hairlike projections of the cytoplasm composed of pairs of microtubules which are surrounded by cell membranes. They tend to be long, in relation to other microbes, some reaching up to 2 mm in length. Cilia are also able to acquire food. Sometimes they are fused into sheets, making them useful for sweeping up food. The macronuclei of Ciliophora harbor many endocytobionts. Ciliophora are multinucleate (having two or more nuclei). Like several other protozoans, ciliates are unicellular heterotrophs. Many feed on bacteria and particles as well as algae. Many are carnivorous. 
Ciliophora can reproduce both sexually or asexually. The macronucleus controls cell functions and asexual reproduction. The micronucleus is involved with sexual reproduction as well. The most common form of reproduction in Cilia is Asexual reproduction by fission. Genetic exchange during sexual reproduction is bent on the micronucleus. After conjugation, the Ciliophora will divide, resulting in four identical organisms. 
Ciliophora are heterotrophic organisms. Some species hunt bacteria, others eat algae, Ciliophora, or detritus. Most Ciliophora are freshwater organisms. They will regularly form relationships with bacteria, some of which may be damaing for the Ciliophora. These relationships can help increase the environmental resiliency of the bacteria. Some species of Ciliophora act as parasites towards humans and other animals. Some species, such as Stentors, form symbiotic relationships with algae. This, in turn, gives them a green tint.
Some species are pathogenic. Anophryoides haemophila causes Bumber Car Disease, a serious affliction of lobsters. It is leading cause of death among lobsters being used for commerical purposes. Bumper Car Disease causes depletion of blood cells. There is no treatment for this disease. Ciliophora are model organisms. It is believed their relationships with bacteria are similar to human relationships with bacteria.