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Ciliates are protozoans with large numbers of eukaryotic flagella. “Motile” cilia behave in a coordinated way to activate cell motion and/or to direct water with food particles toward a “mouth”. Nonmotile “primary” cilia serve as sensory organelles.

Many ciliates host mutualistic photosynthetic endobiotic “algae” whose rate of division may be under the control of the ciliate host.

Some ciliates are planktonic, others are sessile and attached to a substrate.

Loricate ciliates

The tintinnid ciliates produce a protective lorica of taxonomic specificity that contains a proteinaceous material (Agatha and Simon 2012), and often agglutinated foreign particles, generally carbonaceous or silicaceous, including coccolith scales, diatom frustules, or silica chips (Tappan and Loeblich 1968).


Diseases caused by ciliates:

Helicostoma is a genus ofciliates that attacks marine corals, removing and ingesting zooxanthellae(dinophycean endobionts), resulting in “brown jelly disease” in reefs and aquaria, in which coral tissues slough off, ultimately fatal to the coral (Keshavmurthy 2009).

Some ciliates inhabit mammalian intestines where they consume bacteria. The only ciliate that causes human disease is Balantidium coli. Infections of the intestinal parasite, apparently rare, is from pigs. Severe B.coli infections may resemble amoebiasis. Symptoms include diarrhoea, nausea, vomiting and anorexia. The diarrhea may persist for long periods of time resulting in acute fluid loss. Balantidium coli also has the potential to penetrate the mucosa resulting in ulceration (Arcari et al. 2000).


Agatha, S. and P. Simon  2012.  On the nature of tintinnid loricae (Ciliophora: Spirotricha: Tintinnina): a histochemical, enzymatic, EDX, and high-resoltion TEM study.  Acta Protozoology 51(1):1-19

Arcari, M., A. Baxendine, and C.E. Bennett 2000. Diagnosing medical parasites through coprological techniques. online.

Keshavmurthy, S. 2009. Ciliates and coral disease. online.

Tappan, H., and A.R. Loeblish Jr.  1968.  Lorica composition of modern and fossil Tintinnida (Ciliate Protozoa), systematic, geologic distribution, and some new Tertiary taxa.  Journal of Paleontology 42(16):1378-1394.