fusiona fusiona fusiona is a genus of the family fusionidae in the phylum apicomplexa fusiona scientific classification domain: eukaryota (unranked): sar (unranked): alveolata phylum: apicomplexa class: conoidasida subclass: gregarinasina order: eugregarinorida suborder: septatorina superfamily: fusionicae family: fusionidae genus: fusiona species fusiona geusi taxonomy there is one species - fusiona geusi - in this genus. this species infects bees. history this genus was created in 1965 by stejskal. description species in this family are homoxenous. gametocytes - not described spores - not described both gamonts and trophozoites are septate. the gamonts are morphologically different (anisogamous). sexual reproduction involves a cephalocaudal association. during syzygy the nucleus and entrocyte of the satellite move to the primite where they fuse.