Cortical microtubular structures of the ciliate Lepidotrachelophyllum fornicis Nicholls &Lynn, 1984 and phytogeny of the litostomate ciliates

Publisher Website
Google Scholar
Abstract
The somatic and oral cortical ultrastructure of Lepidotrachelophyllum fornicis Nicholls &Lynn, 1984 are described. The somatic kinetids are monokinetids whose fibrillar associates include the following: (i) a kinetodesmal fibril which originates near triplets 6, 7, and 8 and extends laterally and to the right at an angle of about 45° to the longitudinal axis of the kinety; (ii) a postciliary ribbon which originates in dense material near triplet 9 and extends posteriorly and to the right; (iii) a primary transverse ribbon which originates near triplets 3, 4, and 5 and extends to the left and anteriorly; (iv) a secondary transverse ribbon which originates near triplet 5 and curves to extend to the lateral left; and (v) a ribbon of rootlet microtubules which originates on the left at the base of the kinetosome. The oral kinetids are dikinetids. The ciliated posterior kinetosome has the following: (i) a postciliary ribbon which extends posteriorly and to the right; and (ii) a transverse ribbon which extends only a short distance anteriorly. The nonciliated anterior kinetosome has the following: (i) a single postciliary microtubule; (ii) a large transverse ribbon which extends into the oral cone; and (iii) near its base a hexagonal nematodesma. The cytopharyngeal apparatus or rhabdos is described and a schematic figure is presented. The cellular mechanisms underlying body shape changes and food vacuole formation and the phylogeny of the class Litostomatea are discussed.