Ref ID : 7521
J. Grain, P. De Puytorac, R. Detcheva, C.A. Groliere, F. Iftode, and Ghislaine Fryd-Versavel; [Etude Ultrastructurale d'un Cilie Kinetofragmophora: Placus striatus Cohn, 1866]. Protistologica XIV(4):391-404, 1978
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The ultrastructural study of Placus striatus give some informations about: the cortical and somatic infraciliary structures, and about the enigmatic "fossette" which opens behind the "brosse". Each of the 30-34 somatic kineties is composed of only one line of isolated kinetosomes, which are implanted on the right edge of a broad interkinetal groove. The large cortical alveoles often contain bacteria. Under the interkinetal groove, a thick epiplasm forms a gutter which is strenghtened by transversal raised arches; near the cilium, each arch is continued by a cylindrical column. The "brosse" is constituted by two closed kineties, with claviform cilia; it seems to prolong a "parabuccal segment" (9 couples of kinetosomes) on an edge of the lengthened buccal oveture; there are no links between kinetosomes in the "brosse" and in the parabuccal segment. On the right side of these two formations, there is a line of groups of toxicysts. About 30 couples of non ciliated-peribuccal kinetosomes are around the cytostome; each of them gives, at its proximal end, a nemadesme which is divided in two parts (these nemadesma are components of a very long "nasse"), and a ribbon of cytopharyngeal tubules. The inpocketted "fossette" contains a double row of ciliated kinetosomes, and numerous long toxicysts; these ones are ordered in regular lines; they have narrow relations with a thick microfibrillar structure, the origine of which could be the cellular membrane; they can go out of the "fossette". It is great interest to notice that, even in a Prostomatida (Gymnostomata Kinetofragmophora), the single extension of the buccal overture (which remains in apical position) is correlative with the infraciliary differentiation (parabuccal segment) on one of the buccal edges (perhaps the left one).