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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Remanella

Remanella Kahl, 1933 (ref. ID; 3690) or Foissner, 1996 (ref. ID; 4875)

Karyorelictida: Family Loxodidae (ref. ID; 4834)
Gymnostomata: Family Loxodidae (ref. ID; 7523)
Family Loxodidae Butchli, 1889 (ref. ID; 4655, 4875)

[ref. ID; 1618]
Similar Loxodes in general appearance; but with endoskeleton consisting of 12-20 um long spindle-form needles lying below broad ciliated surface in 3-5 longitudinal strings connected with fibrils; Muller's vesicles in some, said to be different from those of Loxodes; sandy shore of sea. (ref. ID; 1618)

[ref. ID; 4875]
Marine Loxodidae with organic spicules forming conspicuous cytoplasmic skeleton, cnidocyst-like extrusomes (nematocysts), one or many Muller vesicles containing single or compound strontium granule, and narrowed or tailed posterior end. (ref. ID; 4875)
Type species; Remanella multinucleata Kahl, 1933 (ref. ID; 4875)
  1. Remanella brunnea Kahl (ref. ID; 3690)
  2. Remanella caudata Dragesco (ref. ID; 3690) reported author and year? (ref. ID; 1890)
  3. Remanella faurei Dragesco, 1954 (ref. ID; 3119) reported year? (ref. ID; 2117, 3690)
  4. Remanella gigas Dragesco (ref. ID; 3690)
  5. Remanella granulosa Kahl, 1933 (ref. ID; 3690, 4834) reported year? (ref. ID; 2117)
  6. Remanella levii Dragesco, 1960 (ref. ID; 3690 original paper)
  7. Remanella margaritifera Kahl, 1933 (ref. ID; 1890, 2117, 2316, 3690)
  8. Remanella microstoma Dragesco (ref. ID; 3690)
  9. Remanella minuta Dragesco (ref. ID; 2117, 3690)
  10. Remanella multinucleata Kahl, 1933 (ref. ID; 3119) reported year? (ref. ID; 2117, 3690, 4655, 7523)
  11. Remanella obtusa (ref. ID; 1890)
  12. Remanella rugosa Kahl, 1933 (ref. ID; 1890, 2117, 2316, 3119, 3690) reported year? (ref. ID; 1618)
  13. Remanella rugosa var. unicorpusculata Kahl (ref. ID; 2117, 3690)
  14. Remanella swedmarki Dragesco (ref. ID; 3690) reported author and year? (ref. ID; 1890)
  15. Remanella trichocystus Dragesco (ref. ID; 3690)
  16. Remanella unirugosa Hartwig, 1973 (ref. ID; 3119 original paper)

Remanella granulosa Kahl, 1933 (ref. ID; 3690, 4834) reported year? (ref. ID; 2117)

Descriptions

This species is a typical marine sand-dwelling ciliate. (ref. ID; 4834)
  • Somatic infraciliature: R. granulosa is unilaterally ciliated. The physiologically ventral side of the flattened lancetshaped body, i.e. the side on which the ciliate glides onto a substratum, is generally considered to be the morphologically right side (Dragesco 1960, 1963; Raikov 1963; De Puytorac & Njine 1970; Foissner & Rieder 1983; etc.). Transverse sections show 10 kineties on this body side. The margins of the flat body (morphologically the dorsal and the ventral bords) are bolster-shaped. The non-ciliated left body side is separated from these thickened margins by a groove and a series of pits, from which the cilia of the two specialized left-side kineties emerge. These cilia are normal in fine structure when compared with right side cilia, though they are often described as stiff. The right side kineties occur in furrows separated by interkinetal ridges. These contain mitochondria and subpellicular pigment granules, the same as the two marginal bolsters. The surface of the left side of the body is smoother; the underlying cytoplasm contains few mitochondria but many subpellicular clustered pigment granules. The kinetosomes cut longitudinally, are about thrice as long as their width and are similar to those of R. multinucleata. The kinetosomes are paired in all right side kineties, as shown by tangential sections; both kinetosomes of a pair are ciliated. Besides numerous mitochondria, the interkinetal spaces (sections through the bases of interkinetal ridges) contain a strong lamellated fibre, a postciliodesma, on the right side of each kinety. The paired kinetosomes show typical associated fibres: postciliary, kinetodesmal and transverse. The postciliary fibre is a ribbon of microtubules in a sheath of electron dense material; it starts from the right-posterior sector of the rear kinetosomes of a pair and proceeds in the right-posterior direction to join the postciliodesma. The postciliodesma is a lamellated stack of about 10 ribbons of microtubules, each originating from a kinetosome pair. This means that in contracted (fixed) animals the postciliary ribbon of microtubules is long enough to pass along about 10 pairs of kinetosomes localized posteriorly in the same kinety. The dense sheath envelops the postciliary microtubules only until they join the postciliodesma. The kinetodesmal filament begins, as usual, in the righthand and sector of the rear kinetosome. The kinetodesmal filament of R. granulosa is definitely single and not bifurcated; it is straight, pointed, and periodically cross-striated, with a period of about 31 nm. The kinetodesmal filament is medium long: while proceeding in the anterior-right direction, it does not become stacked with similar filaments of other (anteriorly placed) kinetosome pairs but ends underlying the postciliodesma well behind the proceding pair of kinetosomes. The transverse fibre is short, it belongs only to the anterior kinetosome of a pair and seems to consist of a ribbon of 5 microtubules. These proceed in the left-anterior direction and seem to enter a cytoplasmic septum crossing the kinety furrow between each pair of cilia. There are two trabeculi of dense material connecting the two kinetosomes of a pair. The right trabeculum, which is thicker, joins the rear kinetosome at the base of the kinetodesmal filament. Though Remanella granulosa is slightly contractile (it usually rolls up when disturbed), no definite myonemes could be found along the right-side kineties, unlike the larger species R. multinucleata (Raikov 1978). The two left-side kineties also consist of paired kinetosomes, but these differ from the right-side ones in that only the anterior kinetosome of a pair is ciliated, while the other is barren. The kinetosome pairs lie in more or less deep furrows on the left-side body surface, from which single cilia emerge. Some kinetosome pairs of the dorsal left-side kinety are associated with statocyst-like formations, the Muller's vesicles. The micrographs available are consistent with the detailed description of these organelles given with respect to Loxodes species (Rieder 1971; Foissner & Rieder 1983; Hemmersbach-Krause 1988; and especially Fenchel & Finlay 1986) and Remanella unicorpusculata (Bedini et al. 1973). These pairs of kinetosomes are deeply in sunk into the cytoplasm, so that the cilium of the ciliated kinetosome is localized mostly inside a narrow ciliary pit, and its free end is much shorter than other cilia of the left-side kineties. In fact, the statocyst-associated kinetosome pairs are invaginated into the lumen of the respective Muller's vesicles themselves, so that many sections of the latter show a cytoplasmic inclusion containing profiles of either two kinetosomes or a ciliary pit with the cilium inside it. The non-ciliated kinetosome is adjacent to the ciliated one and connected, via a stalk formed by membrane and fibre systems, with the inner body of the Muller's vesicle, the statolith. The inner body contains several mineral lithosomes (consisting in Remanella mostly of SrSO4, according to Rieder et al. 1982). (ref. ID; 4834)

    Remanella margaritifera Kahl, 1933 (ref. ID; 1890, 2117, 2316, 3690)

    Descriptions

    Six Muller's bodies observed. Wright (1983) found 3-8. (ref. ID; 2316)

    Measurements

    Average size recorded was 60 um in length and 16 um in breadth while Kahl (1933) and Dragesco (1960) estimated its size at 100-200 um and 70-100 um respectively. (ref. ID; 2316)

    Remanella multinucleata Kahl, 1933 (ref. ID; 3119) reported year? (ref. ID; 2117, 3690, 4655, 7523)

    Descriptions

    Remanella multinucleata Kahl is a multinucleate ciliate having up to 35 macronuclei and 16 micronuclei (Raikov 1963). According to Dragesco (1960), R. multinucleata from Roscoff populations have 12 to 23 macronuclei and 3 to 8 micronuclei. Light microscopy shows that the nuclei form a longitudinal row in the middle part of the ciliate's body; many of them are arranged into characteristic groups. Groups of two macro- and one micronucleus, three macro- and one micronucleus, and two or three macro- and two micronuclei are among the commonest. However, there are always some free macronuclei as well, which are not associated with micronculei. The nuclear groups of R. multinucleata thus seem to be rather unstable. (ref. ID; 4655)
    The ultrastructural study. (ref. ID; 7523)

    Remanella rugosa Kahl, 1933 (ref. ID; 1890, 2117, 2316, 3119) reported year? (ref. ID; 1618)

    Descriptions

    This species was highly thigmotactic and very fragile. Six Muller's bodies observed in the cytoplasm; Kahl (1933) recorded 3-8. (ref. ID; 2316)

    Measurements

    200-300 um long. (ref. ID; 1618)
    260 um. (ref. ID; 2316)