zygocystinae zygocystinae the zygocystinae are a subfamily of parasites in the phylum apicomplexa. zygocystinae scientific classification domain: eukaryota (unranked): sar (unranked): alveolata phylum: apicomplexa class: conoidasida subclass: gregarinasina order: eugregarinorida suborder: aseptatorina family: monocystidae subfamily: zygocystinae genera adelphocystis pleurocystis zygocystis taxonomy there are three genera in this subfamily: adelphocystis, pleurocystis and zygocystis. history this family was created by bhatia in 1930. description species in this subfamily infect worms of the family lumbricidae. in these genera syzygy occurs extremely early in the life cycle. the oocyst is navicular or biconical and has unusual thickenings at both ends.