Description of Cyrtolophosis minor
provided by BioPedia
Ciliate, about 17-23 x 10 microns. Distinctly ovoid, slightly flattened dorso-ventrally, has very characteristic lateral appearance due to large vestibular groove. Macronucleus near centre of cell, spherical; nucleolus reticulate. Micronucleus slightly ellipsoid, about 1 microns in diameter, attached to macronucleus. Contractile vacuole at posterior end. Cortex flexible, distinctly furrowed by somatic kineties. Extrusomes not recognizable in living cells but presumably present as indicated by some small granules and circles in silverlines. Cytoplasm colourless, without conspicuous inclusions. Food vacuoles rather large (3-5 microns) compared to size of cell. Feeds on small, rod-shaped bacteria. Movement slow, in wide spirals. Somatic cilia 8 microns long, arranged in about 8 sparsely ciliated kineties which are curved on ventral and spiralized on dorsal side. Basal bodies paired, anterior cilium lacking in postoral dikinetids. Postoral kineties shortened, thus rather large, non-ciliated patch at posterior end of dorsal side. Preoral suture conspicuous because kineties do not abut, leaving rather wide, non-ciliated gap. Oral apparatus conspicuously large, occupies at least one third of cell's lengch. Oral aperture pentagonal. Vestibulum distinctly pocket-shaped, appears as bright patch in transmitted light. Paroral membrane inconspicuous, comprising 2 segments separated by large gap containing argyrophilic granule. Anterior segment on anterior left vestibular wall, composed of 3-4 large, ciliated granules (very likely dikinetids). Posterior segment on right vestibular wall, consists of 3-4 dikinetids bearing 3-4 very short (about 2 microns) cilia; thus, only one basal body of each pair is ciliated. On left slope of vestibulum are 4 adoral organelles, each composed of 2 rows of cilia about 5 microns long; form distinct, heavily beating membrane. At right side of adoral organelles bracket-shaped row of argyrophilic granules.
