Oocyst(redirected from oocyst plaques)
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one of the stages in the development of protozoans of the class Sporozoa. The oocyst forms as a result of the encyst-ment of a fertilized egg cell. It is covered with a strong protective membrane. The contents of the oocyst generally divide into several nonmotile spores (in Coccidia) or motile sporozoites (in Gregarinidia). In Hemosporidia the oocyst produces thousands of sporozoites, which subsequently leave the oocyst.