Schizocystis

Schizocystidae is a genus of parasitic alveolates in the phylum Apicomplexa.

Species in this family infect insects (Diptera).

History
This genus was created by Léger in 1909.

Taxonomy
The type species is Schizocystis gregarinoides.

Lifecycle
The parasites develop in extracellular locations. The trophozoites are large, band like and wide. They have longitudinal striae and are aseptate. A mucron of small pseudopods or sucker is present. The nuclei are large.

Merogony occurs once in the lifecycle. Nuclear division proceeds with binary fission during growth. Cytokinesis occurs to form uninucleate merozoites arranged in clusters in the shape of the trophozoite. The merozoites become free by dropping off the parent trophozoite.

Gamonts, gametocysts and oocysts are of the actinocephalid type with syzygy occurring just before gametocyst formation.

The young gamonts are vermiform (wormlike). The gametocysts are mostly spherical. The oocysts are spindle-shaped with eight sporozoites.