Lechriopyla

1. Lechriopyla mystax Lynch, 1930 (ref. ID; 4125)

Lechriopyla mystax Lynch, 1930 (ref. ID; 4125)

Descriptions

• Somatic Cortex
  • Kinetids: The kineties are composed of monokinetids which are unusual in that they are placed on cortical ridges rather than in cortical grooves. The kinetosomes are relatively large, about 0.65 um long. Distally, the terminal plate and more distal secondary plate are prominent. The terminal plate is continuous with epiplasmic layer, which is usually quite thin, being less than 20 nm thick. Flattened alveoli overlie the epiplasmic layer. The somatic monokinetids have associated with them the typical fibrillar associates. The postciliary ribbon arises adjacent to triplet 9 and is composed usually of four microtubules that extend slightly posteriad and almost directly upwards to abut on the epiplasmic layer. The well-developed kinetodesmal fibril originates near triplets 5, 6, 7 and extends directly anteriad to overlap the kinetodesmal fibrils from 4-6 anterior kinetids. The presumed transverse microtubules arise from dense material adjacent to triplets 1, 2, 3. These microtubules may extend anteriorly joining a large ribbon of ~10 microtubules which run beneath the right surface of the cortical ridge directly above the bundle of overlapping kinetodesmal fibrils. (ref. ID; 4125)
  • Extrusomes: Long, rod-like extrusomes insert in the cortical ridges at regular intervals between the kinetids. (ref. ID; 4125)
• Oral Cortex
  • Adoral fibers: The boundary between the somatic and oral ciliature is defined by a fiber-like structure that has anterior and posterior components. This adoral fiber is composed of a number of fibrils that arise from the bases of kinetosomes of adjacent somatic kinetids for the anterior component or oral kinetosomes for the posterior component. The kinetodesmal fibrils of somatic kinetids extend above the posterior adoral fiber, terminating in the interkinetal spaces of the oral ciliature. The diameters of the anterior and posterior adoral fibers increase from the right edge to the left edge of the oral cavity opening. The anterior and posterior adoral fibers join at the leftmost edge of the oral cavity where they reach their largest diameter. (ref. ID; 4125)
  • Supraoral ciliature: The kinetids of the supraoral kineties are different from those of the somatic cortex. Except perhaps for the most posterior kinetosome of the row which may have a postciliary ribbon, these kinetids do not have kinetodesmal fibrils, transverse ribbons, or postciliary ribbons. Instead, they are anterior connected by a rootlet system which parallels the cell surface. No difference was observed between the ultrastructure of the cilia of the supraoral kineties and the adjacent somatic kineties. Near the supraoral cilia, ectosymbiotic bacteria were often observed. (ref. ID; 4125)
  • Oral ciliature: The oral ciliature is composed of a series of kineties whose kinetosomes are more densely packed than those of somatic kineties. The oral kinetosomes, like the supraoral kinetosomes, apparently have none of the fibrillar associates of somatic kinetosomes. Parasomal sacs are distributed between oral kinetosomes, slightly to the right of the midline of the kinety. Occasionally, a ribbon of microtubules of undetermined origin extends adjacent to some oral kinetosomes. Rootlets originate from the base of oral kinetosomes. There may be two or perhaps three of these rootlets, which extend inwards beneath the oral cavity surface to overlap the rootlets of more internal kinetosomes. These complex bundles of rootlets, called lamellae, increase in depth as they extend deeper in the oral cavity. It has not been possible to determine the exact course of individual rootlets; however, they do form complex interwoven patterns, some reminiscent of braiding. These assemblages of rootlets converge on a fork-shaped structure called the furcula, whose cortex is composed of rootlet fibers and whose inner portion is homogeneous ground substance traversed by tracts of rootlets. Oral kinetosomes, both external and entad to the furcula, contribute rootlets to build this structure. (ref. ID; 4125)
  • Cytostome and cytopharynx: The cytostome is near the base of the funnel-shaped oral cavity. In the region of transition between the oral ciliature and the cytostome, there is a portion of non-ciliated, alveolar cortex. It is in this region that microtubular ribbons originate to extend into the cytoplasm as the cytopharynx. Small vesicles, some of which fuse with the plasmalemma, are associated with these microtubular ribbons. Dense material that has not been seen associated with any kinetosomes and an outer loosely arranged assemblage of microtubules accompany the ribbons very near their origin. These ribbons, which appear to undulate slightly, extend into the cytoplasm as the cytopharygeal ribbons; dense granules, perhaps lysosomes, can be seen accompanying them. (ref. ID; 4125)