Plasmodiid apicomplexa, causative agent of malaria, gamonts in erythrocytes; merogony in erythrocytes and other tissues depending on species; hemozoin deposited; vectors mosquitoes or phlebotomine flies; in mammals, birds, and reptiles; cause of estimated two million deaths annually; most important human species are P. vivax (causes benign tertian malaria) and P. falciparum (causesmalignant tertian malaria); Type species P. malariae