aikinetocystidae aikinetocystidae the aikinetocystidae are a family of parasitic alveolates in the phylum apicomplexa. the species in this family infect oligochaetes. aikinetocystidae scientific classification domain: eukaryota (unranked): sar (unranked): alveolata phylum: apicomplexa class: conoidasida subclass: gregarinasina order: eugregarinorida suborder: aseptatorina family: aikinetocystidae genera aikinetocystis nellocystis taxonomy this family was created in 1930 by bhatia. two genera are recognised in this family - aikinetocystis and nellocystis. description the species in this family infect the coelom of oligochaetes. they are spread by the oral-faecal route. the trophozoite is aseptate. the gamont is sac-like and extends at one end into two branches which divide dichotomously, forming eight to 16 secondary branches bearing groups of suckers. the oocysts are biconical (fusiform).