Stomatogenesis during metamorphosis of Eufolliculina uhligi (Ciliophora, Heterotrichida)

The marine, loricate ciliate Eufolliculina uhligi (Heterotrichida) has a complex life-cycle which includes a motile swarmer. The swarmer settles on the substrate, secretes a lorica and transforms into the trophic stage. This is metamorphosis. Swarmers have been induced to settle by treatment with EGTA to synchronize metamorphosis. Stomatogenesis was observed in protargol-stained cells. It can be characterized as follows: Stomatogenesis of E. uhligi (suborder Coliphorina) is compared with that of members of the suborder Heterotrichina. It is concluded that folliculinids are closely related to the Stentoridae. The separation of the Folliculinidae from the other Heterotrichida should be reconsidered.