Section III. CLASS SPOROZOA
Reproduction in this class is accomplished through both sexual and asexual
cycles. All members are parasitic and usually require two hosts to complete the cycle.
Sporozoans use body flexion, gliding, or undulation of longitudinal ridges as means of
motility. Small pseudopods are used for feeding. There are three families in the class:
family Eimeriidae, family Endodyococcidoridae, and family Plasmodiidae.
The life cycle of the family Eimeriidae can be completed in one host, but two
hosts may be used. The macrogametocytes and the microgametocytes are developed
independently. The zygote is non-motile and sporozoites are formed inside a sporocyst.
The members of this family parasitic to man are: Isospora belli, Eimeria species, and
All members are intracellular parasites of vertebrates. Three species are
pathogenic to humans: Toxoplasma gondii, Sarcocystis hominis, and Pneumocystis
2-10. FAMILY PLASMODIIDAE
Plasmodium is the representative genus of this class. These organisms live as
intracellular parasites in the red blood cells of the intermediate host (man) and multiply
asexually through a process known as schizogony. In the definitive host, there is sexual
reproduction which takes place in the gut, hemolymph, and salivary glands of the
mosquito. The gametes are developed independently and the zygote (ookinete) is