Inside the red blood cells, oval-shaped merozoites stop proceeding with erythrocytic cycle to increase in size and become rounded gametocytes. Male gametocytes or microgametocytes are smaller and contain a large diffused nucleus. Female gametocytes (or mega gametocytes) are larger with a small compact peripheral nucleus. These do not divide but remain as intracellular parasites within their host's blood corpuscles, until they either die or are ingested by the vectors. They give rise to gametes in insects.