Four infective sporozoites exit through suture. Sporozoites penetrate epithelial cells, especially along the ileum. Meronts rupture, releasing free merozoites.
Merozoites penetrate new cells and undergo merogony to form additional meronts.
I merozoites form Type II meronts, which contain 4 merozoites. Microgametes fertilize macrogametes. Oocysts are passed in the feces. It is believed that the resulting sporozoites produced from thin-walled oocysts can excyst while still within the gut and infect new cells in a second autoinfective cycle.