Apicomplexa lifecycle stages#Feeding stages

An oocyst (plural: oocysts, gr Oos, egg and Kystis, bladder ) is a microscopically visible stages of Apicomplexa.

It contains Sporulationstyp depending on a certain number of sporocysts, which in turn contain a certain number of sporozoites. In the genus Eimeria example, these are four sporocysts, each containing two sporozoites. Oocysts of the genera Isospora and Toxoplasma contain sporocysts and sporozoites in inverse ratio, ie 2 sporocysts each with 4 sporozoites. After maturation, the oocyst, sporulation, the released sporozoites invade actively in nucleated host cells and multiply there.