The postembryonic ontogeny of the thelytokus acarid mite, Schwiebea elongata Banks, 1906, is described from specimens collected and reared from a swinmming pool in Japan and preserved material from an eel hatchery in Canada. The male, heteromorphic deutonymph and homeomorphic immature stages are described for the first time. Variation is described in the form of the prodorsal sclerite, presence/absence of idiosomal setae c1 and d1, and in the form of the empodial claws of the female. Males and deutonymphs strongly resemble those of S. zingiberi Manson, 1972, but S. elongata males constantly retained dorsal seta d1. The deutonymphs of both S. elongata and S.zingiberi were identical morphologically.