The motile elongated zygote of the malarial parasite (Plasmodium), formed after fertilization of the macrogamete. The ookinete bores through the lining of the mosquito’s stomach and attaches itself to the outer wall, where it later forms an oocyst.
An elongated motile zygote occurring in the life cycle of certain sporozoan parasites, especially those of the genus Plasmodium. It penetrates the stomach wall of a mosquito and gives rise to an oocyst.