Encyclopedia of Parasitology

2016 Edition
| Editors: Heinz Mehlhorn


  • Heinz Mehlhorn
Reference work entry
DOI: https://doi.org/10.1007/978-3-662-43978-4_2214
Stage in the life cycle of  Coccidia containing (eventually inside of sporocysts) infectious sporozoites. In fecally transmitted species, oocysts are always resistant stages whereas in bite-transmitted groups (e.g.,   Plasmodium ) oocysts are smooth and always located inside the vector (Figs. 1, and 2).
Oocyst, Fig. 1

Sporulated oocyst of the coccidian genus Eimeria. AW outer wall, IW inner wall, MK micropyle, N nucleus, PK polar body, RK refractile body, RO residual body of oocyst, RS residual body of sporocyst, S sporocyst, SP sporozoite, SST substieda body, ST stieda body

Oocyst, Fig. 2

Diagrammatic representation of an unsporulated (a) and a sporulated (b) oocyst of Isospora belli. N nucleus, OW oocyst wall, R residual body, SP sporozoite, SW sporocyst wall, Z zygote

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© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.Institut für Zoomorphologie, Zellbiologie und ParasitologieHeinrich-Heine-UniversitätDüsseldorfGermany