Ultrastructure of Prorodon (Ciliophora, Prostomatida) Ii. Oral Cortex and Phylogenetic Conclusions

Abstract

ABSTRACT. The ultrastructure of the oral region and the ultrastructural architecture of the basket of Prorodon aklitolophon and Prorodon teres are described. the oral region of Prorodon consists of: 1) A circumoral kinety at the anterior pole of the cell surrounding the typically slit‐shaped cytostomial funnel. This kinety is composed of inversely oriented dikinetids in which both kinetosomes are ciliated and are associated with a very short postciliary microtubular ribbon and a few transverse microtubules; 2) Three brush rows aligned in parallel and extended meridionally in the anterior part of the cell. the individual brush rows consist of dikinetids, but in contrast to the dikinetids around the cytopharynx they are not inverted and only the anterior kinetosomes bear specialized short brush cilia and are associated with a divergent‐tangential transverse microtubular ribbon. the posterior kinetosome is non‐ciliated and bears a prominent convergent postciliary microtubular ribbon. Schematized dikinetid patterns of both oral regions of Prorodon are provided. In addition, a three‐dimensional reconstruction of the basket of the genus Prorodon based on serial thin sections is presented. A phylogenetic tree, mainly based on stomatogenic data, is given to show the phylogenetic relationships of some prostomatid genera as well as the hypothesized sistergroup relationship of colpodid and prostomatid ciliates.

Ultrastructure observation on the cells at different life history stages of Cryptocaryon irritans (Ciliophora: Prostomatea), a parasitic ciliate of marine fishes

“…It might be located either inside or outside the circumoral ciliary row of an apical cytostome or at the aboral side of a subapical cytostome (Lynn and Small, 1985;Lynn, 2008). When composed of dikinetids, the front or right basal bodies usually bore clavate cilia, while the rear or left basal bodies were unciliated (Hiller, 1991(Hiller, , 1993bBardele, 1999;Lynn, 2008). The adoral brosse of C. irritans was located on the centre-right of the aboral surface, outside the circumoral dikinetid ciliary row and was composed of three-rowed dikinetids.…”

Ultrastructure of Prorodon (Ciliophora, Prostomatida) I. Somatic Cortex and Some Implications Concerning Kinetid Evolution In Prostomatid and Colpodid Ciliates

“…This situation is quite unlike that found in other ciliates (e.g. [52]) and therefore might be considered as an autapomorphic character of the genus Prorodon [34]. The contractile vacuole pores, ampullae and collecting canals of other ciliates are supported by microtubules as well, but detailed information about the origin of these microtubules is not yet available [3, 46, 62, 64, 671. A similar system of collecting canals has been observed by de Puytorac [7 11 in P. viridis.…”

“…Since the infraciliature and the life cycle of P. aklitolophon have recently been described in detail [35], the following account describes some light microscopical features of P. teres only. This survey also includes some details concerning the oral ciliature (including the brush and the basket) of P. teres, which will be described in detail in the second part of this contribution [34].…”

“…Finding a significant similarity between the somatic dikinetid pattern of Prorodon and of the colpodids [ l , 49,50,52,741 was one of the most surprising results of this investigation. Based on these data the colpodid kinetid pattern is hypothesized to be derived from a hypothetical ancestor that was very Prorodon-like and not from a haptorid or nassulid-like ancestor as suggested by several authors [ 1, 22, 451. In the second part of this contribution [34], the oral ciliature and the brush of Prorodon are examined more closely. The results of both parts will be used together with stomatogenic data to construct a phylogenetic tree of the prostomatid and colpodid ciliates.…”

Some Ultrastructural Features of the Planktonic Freshwater Ciliate Limnostrombidium viride (Alveolata, Ciliophora, Oligotrichida) and Improved Diagnoses of Oligotrich Taxa

“…Club-shaped cilia with a potentially sensory function are found in the brush rows of a large variety of ciliates. The brush cilia vary in their axonemal structures, i.e., the structure is retained (Hiller 1993), the links between the microtubules are missing (Golińska 1982), or the central microtubules are absent (Bardele et al 2017). Data on protists and metazoans indicate that a sensory function is not restricted to primary (sensory) cilia with “9×2+0”-axonemes (Hubert et al 1975, Fenchel and Finlay 1986, Ibañez-Tallon et al 2003, Bloodgood 2010, Satir 2017).…”