THE ORAL-APPARATUS OF COLPODA-VARIABILIS (CILIOPHORA, COLPODIDAE) .1. 3-D RECONSTRUCTION BY SERIAL SEMITHIN SECTIONS AND LOW-TEMPERATURE SCANNING ELECTRON-MICROSCOPY

A three-dimensional reconstruction of the oral apparatus of Colpoda variabilis was done by serial semi-thin sections and low temperature scanning electron microscopy. The inner part of the oral cavity is separated from the outer part by an oral ridge on its left side and by a vestibular ridge on its right side. A banana-shaped left oral polykinetid is situated on the left wall of the oral cavity, not extending into the inner part of the oral cavity. A triangular-shaped right oral polykinetid is situated on the right wall of the oral cavity, partially positioned in the inner part of the oral cavity and on the vestibular ridge. Six vestibular kineties, being the anterior ends of somatic kineties, are situated on the right wall of the oral cavity as well. The longitudinal axis of the left oral polykinetid includes an angle of about 45° with the anterior-posterior axis of the cell. The longitudinal axis of the right oral polykinetid shows a parallel orientation to the anterior-posterior axis of the cell. Based on the three-dimensional reconstruction of the oral apparatus, and especially on the position of the oral polykinetids, the separation of the genera Paracolpoda, Colpoda, Tillina and Bresslaua is discussed. © 1990, Gustav Fischer Verlag · Stuttgart · New York. All rights reserved.