Malaria parasites. Coloured transmission electron micrograph (TEM) of malaria sporozoites in a mosquito (Anopheles sp.) gut. The sporozoites (Plasmodium sp., purple) are seen bursting from an oocyst (white/yellow) at upper right. The oocyst is on the gut wall of the mosquito. The sporozoite stage, produced by asexual replication, will migrate to the mosquito's salivary glands, and will then infect humans when the mosquito feeds. Malaria parasites later infect human red blood cells, causing anaemia, cyclic fevers and even death. Magnification unknown.