An Annotated List of Protozoan Parasites Belonging to the Genus Monocystis von Stein, 1848 (Apicomplexa: Conoidasida: Eugregarinidida: Monocystidae) Described from Oligochaete Hosts

Apicomplexan are parasitic, with the gregarines exclusively infecting invertebrate hosts. Gregarines are a group with two forms, septate and aseptate. Aseptate gregarines contains 400 species while the septate gregarines contains about 900 species (Levine, 1977). In the aseptate gregarines (acephaline) the trophozoite has one compartment while in the septate forms (cephaline) there are several compartments. Gregarines are certainly significant from an evolutionary point of view because of their suspected early diverging position. The genus Monocystis was established by Von Stein in 1848.