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(invertebrate zoology)
A subclass of protozoans in the class Telosporea; typically intracellular parasites of epithelial tissue in vertebrates and invertebrates.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



an order of one-celled animals of the class Sporozoa. There are approximately 1,000 species. They are intracellular parasites of the epithelial tissue primarily of the digestive organs of invertebrates (annelid worms, mollusks, and arthropods) and vertebrates. They look like small rounded cells with a bubble-shaped nucleus.

Almost every species of Coccidia parasitizes only one definite species of animal host. Most Coccidia exhibit regular alternation of asexual reproduction (schizogony), a sexual process, and sporogony. Asexual reproduction is absent only in the most primitive group—Protococcidiida (genus Eucoccidium). Spores keep the sporozoites viable outside the host’s body for several months, until the oocyst is swallowed by the animal host. The majority of species of Coccidia develop in one host. Some Coccidia have two—for example, members of the genus Aggregata undergo asexual reproduction (schizogony) in crabs and the sexual process and sporogony in gastropod mollusks. Coccidia are very widely distributed. Some cause coccidiosis.


Kheisin, E. M. Zhiznennye tsikly koktsidii domashnikh zhivotnykh. Leningrad, 1967.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
-- This represents the first report of a coccidian from any member of the family Helodermatidae.
A new species of coccidian (Apicomplexa: Eimeriidae) from the prairie racerunner, Cnemidophorus sexlineatus viridis (Sauria: Teiidae), in Arkansas.
It is difficult to link this tissue damage to the coccidian parasite found, because it was present only in 3 of the 14 clams examined.
However, to the best of our knowledge, there are not published studies on the seasonal variation of the infection parameters (prevalence, mean intensity) or mortality produced by coccidian parasites of bivalves, and its association with environmental factors such as temperature or salinity remains unknown.
Iva Dykova (Institute of Parasitology of the Academy of Sciences of the Czech Republic) for their help in the identification of the coccidian parasite.
(Apicomplexa: Eimeriidae), a parasite of native littleneck clams, Protothaca staminea, from British Columbia, Canada, with a revision of the coccidian parasites of bivalves (Mollusca: Bivalvia).
Both turtles were found to be passing coccidian parasites, including a new species of Eimeria.
Coccidian infections of western painted turtles of the Okoboji region.
Coccidian parasites (Apicomplexa: Eimeriidae) of Graptemys caglei and Graptemys versa (Testudines: Emydidae) from Texas.