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Name derivation:

"Marginal small teeth" -- Marginal Chil- small teeth -odonella

Morphology:

Flat cell with dorsal-ventral compression. Has a distinct -re-oral "beak". cilia are absent on the dorsal surface but present on most of the ventral surfac. Cytopharynx with well-developed rod apparatus (Das 2003).

Similar genera:

Importance:

At least one species (C. uncinata) is an endoparasite in disease-carrying mosquitoes in India, thus potentially is a biological control mechanism reducing the incidence of Japanese encephalitis in humans (Das 2003).

Other species are ectoparasites that infect the epithelium, especially the gills, of fish. Some examples:

C. hexasticha has been associated with fish kills (Bony bream and other species) in the Finke River, Australia during periods of low flow rates and high water temperatures (Langdon et al. 2008), with deaths of cichlid fish from Israel and South Africa (Paperna and Van As 2006), and with "severe epizootics" on channel catish (Ictalurus punctatus) and a goldfish (Carassius auratus) at 19 - 22 C in North America (Hoffman et al. 1979).

C. piscicola has caused reduced growth and "chronic mortalities" in a Japanese salmon hatchery (Urawa and Yamao 1992), and along with C. hexasticha, in four Finnish salmon hatcheries (Rintamaki et al. 2007).

C. cyprinii is a common fish parasite globally in aquaria with poor water quality, attacking epithelial tissues of fish.

Habitat:

Freshwater pools, rice paddies.

References:

Das, B.P.  2003.  Chilodonella uncinata - a protozoa pathogenic to mosquito larvae.  Current Science 85:483-489. [Online]

Hoffman, G.L., S.L. Kazubski, A.J. Mitchell, and C.E. Smith  1979.  Chilodonella hexasticha (Kiernik, 1909) (Protozoa, Ciliata) from Nort American warmwater fish. J. Fish Diseases 2:153-157. [Online]

Langdon, J.S., N. Gudkovs, J.D. Humphrey, and E.C. Saxon  2008.  Deaths in Australian freshwater fishes associated with Chilodonella hexasticha infection. Australian Veterinary Journal 62:409-413. [Online]

Paperma, I, . and J.G. Van As  2006.  The pathology of Chilodonella hexasticha (Kiernik). Infections in cichlid fishes. J. Fish Biol. 23:441-450. [Online]

Rintamaki, P., H. Torpström, and A. Bloigu 1994. Chilodonella spp. at four fish farms in Northern Finland. Eukaryotic Microbiol. 41:602-607. [Online]

Urawa, S., and S. Yamao 1992. Scanning electron microscopy and pathogenicity of Chilodonella piscicola (Ciliophora) on juvenile salmonids. J. Aquatic Animal Health 4:188-197. [Online]