Cyrtolophosis elongata (Colpodea, Ciliophora): Some aspects of ciliary pattern, division, cortical and nuclear changes during encystment and resting cyst ultrastructure

摘要

Cyrtolophosis elongata is a small soil ciliate of the order Cyrtolophosidida, class Colpodea. Using the silver carbonate method we have been able to study the ciliary pattern of vegetative and dividing cells. Transmission electron microscopy revealed that there is no micro-macronuclear complex in this species. This type of nuclear apparatus thus cannot be considered as most important apomorphy of the Cyrtolophosidida. Division is in the swimming condition, stomatogenesis is pleurotelokinetal. Feulgen stain indicates the absence of a macronuclear chromatin extrusion process during both division and encystment. Cortical and cytoplasmic phenomena during encystment are similar to those of Colpoda spp. These data and ultrastructural observations of mature resting cysts indicate that Cyrtolophosis elongata has resting cysts of PKR (Partial-kinetosome-resorbing) type, with a cyst wall composed by two layers. [References: 60]