choanomastigote

cho·a·no·mas·ti·gote

(kō'an-ō-mas'tī-gōt), A term, in the series used to describe developmental stages of the parasitic flagellates, denoting the "barleycorn" form of the flagellate in the genus Crithidia characterized by a collarlike extension surrounding the anterior and through which the single flagellum emerges.
See also: amastigote, epimastigote, promastigote, trypomastigote. Synonym(s): choanoflagellate, collared flagellate [G. choanē, a funnel, + mastix, whip]