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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Enchelyodon

Enchelyodon Claparede & Lachmann, 1858 (ref. ID; 3540, 3690) or 1859 (ref. ID; 2013, 4919)

Class Kinetofragminophora: Subclass Gymnostomata: Order Haptorida: Family Enchelyidae (ref. ID; 2013)

[ref. ID; 2013]
Body outline shape rounded, flask-like, elongate or oval, rounded in cross-section. Anterior domed or with very short, but distinct snout-like region which is usually armed with trichocysts and often surrounded by long cilia. Oral aperture at end of snout region. Cytopharynx supported by trichites. Somatic ciliation uniform and complete with dorsal brush formed from anterior ends of 1 to 4 kineties whose ciliary bases are often paired. Usually single macronucleus, rounded to elongate, rarely the macronucleus is in two parts. Contractile vacuole posterior.
Quote; Colin R. Curds "British and other freshwater ciliated protozoa Part I Ciliophora: Kinetofragminophora" Cambridge University Press, 1982 (ref. ID; 2013)

[ref. ID; 4919]
It includes flask-shaped or oval ciliates with an apical oral bulge. The oral bulge always contains extrusomes and is surrounded by a dikinetidal circumoral kinety. One of the most significant morphological features of the genus is the presence of a dorsal brush constituted by three kineties with paired kinetosomes. All Enchelyodon spp. are predatory. Kahl (1930, 1935) reported many members of the genus Enchelyodon and placed them in the family Holophryidae Perty, 1852. In a refined classification by Corliss (1979), Enchelyodon was placed in the family Enchelyidae Ehrenberg, 1838 (syn. Holophryidae Perty, 1852) of the order Haptorida Corliss, 1974 and the subclass Gymnostomata Butschli, 1889. Foissner (1984) presented a phylogenetic analysis of taxa of the class Kinetofragminophora including Enchelyodon, in which the considered the differences in the silverline system, dorsal brush, and extrusomes as the most important characteristics for species and even genus identification. Because of the presence of a circumoral kinety composed of dikinetids, the genus Enchelyodon was removed from the family Enchelyidae and included in the family Trachellophyllidae Kent, 1882, order Haptorida Corliss, 1974, subclass Haptoria Corliss, 1974, class Litostomatea, Small and Lynn, 1981 (Small and Lynn 2002). However, Enchelyodon lacks the cortical scales typical of the family Trachellophyllidae, and in a recent report on soil ciliates from Namibia, Foissner et al. (2002) proposed a new classification of the genus Enchelyodon, in which they put Enchelyodon (with a closed oral bulge) and Enchelyidium (with a cylindroid, open oral bulge) into a new family, Enchelyodontidae. (ref. ID; 4919)
  1. Enchelyodon amphoriforme Vuxanovici (ref. ID; 4919)
  2. Enchelyodon amphoriforme f. grandis Vuxanovici (ref. ID; 4919)
  3. Enchelyodon anulatus (ref. ID; 4612)
  4. Enchelyodon armatides (ref. ID; 4919)
  5. Enchelyodon armatus Kahl, 1926 (ref. ID; 1619, 3540, 4919)
  6. Enchelyodon californicus Kahl (ref. ID; 1618, 1620)
  7. Enchelyodon contractilis Vuxanovici (ref. ID; 4919)
  8. Enchelyodon elegans Kahl, 1926 (ref. ID; 1335, 1619, 1629, 3540, 4919) or (Kahl, 1926) Kahl, 1930 (ref. ID; 4612)
    Syn; Spathidium elegans Kahl, 1926 (ref. ID; 4612)
  9. Enchelyodon elegans var. striatus Kahl, 1930 (ref. ID; 3540 original paper, 4919) reported author and year? (ref. ID; 1619)
  10. Enchelyodon farctus Claparede & Lachmann, 1858 (ref. ID; 3115) or 1859 (ref. ID; 1619, 3540) reported author and year? (ref. ID; 4612)
  11. Enchelyodon fascinucleatus Kahl, 1933 (ref. ID; 1620)
  12. Enchelyodon fusidens Kahl, 1930 (ref. ID; 3540 original paper) reported author and year? (ref. ID; 1619, 4612)
  13. Enchelyodon kenyaensis (ref. ID; 4919)
  14. Enchelyodon laevis Quennerstedt (ref. ID; 3690)
  15. Enchelyodon lageniformis Vuxanovici (ref. ID; 4919)
  16. Enchelyodon lasius Stokes, 1885 (ref. ID; 1619, 3540)
  17. Enchelyodon longikineta Senler & Yildiz, 2003 (ref. ID; 4919 original paper)
  18. Enchelyodon longinucleatus Foissner, 1984 (ref. ID; 4919)
  19. Enchelyodon megastoma (ref. ID; 4919)
  20. Enchelyodon metabolicus Vuxanovici (ref. ID; 4919)
  21. Enchelyodon minutus (ref. ID; 4919)
  22. Enchelyodon monilatus Kahl, 1930 (ref. ID; 3540 original paper) reported author and year? (ref. ID; 1619, 4612)
  23. Enchelyodon mucicola Kahl, 1927 (ref. ID; 1619, 3540)
  24. Enchelyodon nervuratus Vuxanovici (ref. ID; 4919)
  25. Enchelyodon nodosus Berger et al., 1984 (ref. ID; 4919)
  26. Enchelyodon ovum Groliere, 1977
    See; Balantidion pellucidum (ref. ID; 4613)
  27. Enchelyodon pyriformis Vuxanovici (ref. ID; 4919)
  28. Enchelyodon retortus Vuxanovici (ref. ID; 4919)
  29. Enchelyodon striatus Gourret & Roeser, 1886
    See; Trachelocerca laevis (ref. ID; 1619, 3540)
  30. Enchelyodon sulcatus Kahl, 1930 (ref. ID; 3540 original paper) reported author and year? (ref. ID; 1619)
  31. Enchelyodon terrenus (ref. ID; 4919)
  32. Enchelyodon trepida (Kahl, 1928) Borror, 1965 (ref. ID; 645)
    Syn; Trachelocerca trepida Kahl, 1928 (ref. ID; 645)
  33. Enchelyodon trilineatus Penard, 1922 (ref. ID; 1619, 3540, 4919)
  34. Enchelyodon truncatus Vuxanovici (ref. ID; 4919)
  35. Enchelyodon vacuolatus Dragesco, 1960 (ref. ID; 3690 original paper)
  36. Enchelyodon vesiculosus Stokes, 1894 (ref. ID; 1619, 3540)
  37. Enchelyodon vorax Penard, 1922 (ref. ID; 1619, 3540)

Enchelyodon californicus Kahl (ref. ID; 1618, 1620)

Descriptions

Elongate ovoid to nearly cylindrical; not distinctly flattened; macronucleus horseshoe-like, with a large micronucleus; in mosses. (ref. ID; 1618)

Measurements

120-130 um long. (ref. ID; 1618)

Enchelyodon longikineta Senler & Yildiz, 2003 (ref. ID; 4919 original paper)

Diagnosis

Cells in vivo about 179x115 um, body expanded oval or flask-shaped with hemispherical oral bulge. Macronucleus ribbon-shaped, long and bent into a coil, many spherical micronuclei. Two size types of rod-shaped extrusomes (in vivo around 3.5 um and 57 um long) in oral bulge and cytoplasm. Single terminal contractile vacuole. On average 89 somatic kineties, of which three form a very long dorsal brush extending from the circumoral kinety almost to the posterior end of the body. Circumoral kinety composed of 64-96 dikinetids. (ref. ID; 4919)

Descriptions

Size in vivo 160-195 um long (mean=179.2, SD=9.3, CV=5.2, N=14) and 90-130 um wide (mean=114.5, SD=9.8, CV=8.6, N=14); width of the body is 53-74% of its length, on average 68%, in silver nitrate preparations. Body shape in vivo moderately variable but not flattened; outline an expanded oval or flask shaped, generally widest at or near mid-body. Anterior distinctly narrowed to the hemispherical oral bulge. Posterior end of body broadly rounded, never pointed or elongated. Anteriorly, ventral side straight to slightly concave, dorsal side (with dorsal brush) convex; anterior part therefore seems slightly curved. Body not contractile. Macronucleus ribbon-shaped located almost centrally, bent into an irregular coil about 45-155 um long, but with uncoiled length of 205-315 um (102-163% of the cell length); rarely in two pieces of varying length. Cytoplasm contains small spherical bodies of apparently macronuclear material; these may comprise chromatin derived by extrusion or hemixis during a reorganization process in the macronucleus or may come from prey organisms. Many globular micronuclei with a diameter of 4-6 um irregularly distributed throughout the cell. Contractile vacuole at posterior end, with 4-7 slightly sub-polar excretion pores. Two size-types of rod-shaped extrusomes in oral region and cytoplasm; type I about 3-4 um long (mean=3.5, SD=0.4, CV=10.6, N=20); type II about 51-63 um long (mean=56.7, SD=4.5, CV=8.0, N=10). In silver carbonate-impregnated specimens there were additional (developing?) extrusomes (27-80 um long), enlarged in their mid-region. Orientated extrusome bundles, presumably of type II, as well as individual extrusomes, in the cytoplasm in silver carbonate preparations. Pellicle smooth. Endoplasm containing many tiny, refractive granules and several larger food vacuoles with undefined content; for this reason, the body appears dark, particularly at low magnification. Cells swim slowly with rotation about main body axis. Infraciliature typical for genus. Somatic ciliation uniform and complete, with dorsal brush. Cilia 13 um long in vivo, arranged in 72-110 meridional kineties of varied length, composed of 67-117 kinetosomes; three kineties anteriorly differentiated to a long dorsal brush extending from circumoral kinety nearly to posterior body end. Brush kineties 1 and 2 of about same length (about 157-158 um, extending 81% of the body length in fixed specimens), each composed of 158 paired kinetosomes with 2-3 um long bristles; kinety 3 consists of about 32-40 anterior dikinetids followed by a monokinetidal tail with about 3 um long bristles; tail reaches to nearly posterior body end (about 159 um, extending 82% of the body length). Silverline system mostly with narrow meshes arranged longitudinally, but the mesh is much broader in the field of the dorsal brush. Oral bulge occupies anterior end of body, rather conspicuous in vivo with width about 20 um and height 12 um, appearing button-like, and containing extrusomes. Especially, after silver-carbonate impregnation the oral bulge and extrusomes form a conspicuous circumoral corona. Circumoral kinety at base of oral bulge, composed of 64-96 dikinetids with at least one kinetosome ciliated, exceeding the number of somatic kineties whose anterior end reach the circumoral kinety. Oral basket not recognizable either in vivo or in silver preparations. (ref. ID; 4919)

Comments

The present species can be easily distinguished from most congeners, mainly in respect of the shape and size of the body, nuclear pattern, extrusomes, dorsal brush, and the number of somatic kineties. There are several Enchelyodon species with a similar nuclear configuration: all have a different size, shape, oral bulge, contractility and/or extrusomes. Enchelyodon longikineta shows considerable similarity to E. elegans Kahl, 1926, E. nodosus Berger et al., 1984 and E. longinucleatus Foissner, 1984, differing mainly in the length of the dorsal brush: all others have a shorter dorsal brush. Minor differences occur in body shape, the extrusomes, the oral bulge, and the number of somatic kineties. E. longikineta is rather similar to E. armatus Kahl, 1926, as defined by Kahl (1930). However, Kahl's organism is considerably smaller (100-110 um vs. 160-190 um) than our species and one of the brush rows extends to the posterior. E. elegans var. striatus Kahl, 1930 is also very similar to our species in general appearance; however it differs in the dorsal brush, the number of somatic kineties (30 vs. 89) and the length of the body (150 vs. 180), and is also strongly contractile. Details of dorsal brush in E. elegans var. striatus are the same as in E. armatus; one of three rows is longer than the others, and extends close to the posterior end. There is only one species with a similar dorsal brush configuration to E. longikineta, viz., E. trilineatus Penard, 1922, in which also all of the three rows end close to the posterior, according to the redescription by Kahl (1930). E. longikineta differs from E. trilineatus mainly in the shape and size of the macronucleus (horseshoe-shaped and short in E. trilineatus). Further, E. trilineatus is distinctly smaller than our species (80-100 um vs. 160-190 um). Unfortunately, a more detailed comparison is impossible because of the absence of details of infraciliature and extrusomes of E. trilineatus. (ref. ID; 4919)

Etymology

Enchelyodon longikineta n. sp. is named from its possession of a very long dorsal brush. (ref. ID; 4919)

Type location

Bostanici pond, Van, Turkey (43 degrees 25'E, 38 degrees 32'N, Alt. 1780 m). (ref. ID; 4919)

Type specimens

A holotype slide of silver nitrate impregnated specimens has been deposited in the Laboratory of Biology, Yuzuncu Yil University, Van, Turkey. Two paratype slides of silver impregnated specimens have been deposited in the free-living protozoon (FLP) collection of the Zoology Section, Department of Biology, Faculty or Science, Ege University (ZSBEU), Izmir, Turkey on the slides nos. ZSBEU-FLP.1/PN 1-2. (ref. ID; 4919)

Enchelyodon trepida (Kahl, 1928) Borror, 1965 (ref. ID; 645)

Synonym

Trachelocerca trepida Kahl, 1928 (ref. ID; 645)

Descriptions

Length 90 to 100 um, body round in cross section and roughly bottle-shaped with a slightly tilted neck. The neck is hyaline, and the rest of the body is filled with black granules. The contractile vacuole lies caudal. The cilia are arranged in 18 kineties. They are 3 um long, increasing to 8 um at the caudal pole. At the oral end the separation between the last 5 kinetosomes of each kinety is reduced, forming a kinetosome band that surrounds the cytostome with tufts of cilia. Protargol preparations reveal that the kinetosomes are arranged singly and not in pairs; this is consistent with the finding of Borror (1965). Agamaliev (1978) states that the kinetosomes are paired; however, his animals were impregnated with AgNO3. In this method of preparation a parasomal sac on the right of each kinetosome is also stained, giving the impression of a paired arrangement. On the left edge of the neck of the living animal one can see a strip, about 20 um long, of closely packed rigid cilia, the brush. Borror (1965) has described two more kinety fragments to the left of the brush and anterior to the kineties in the oral field. Wilbert & Kahan concluded not find these. The macronucleus is C-shaped, or sometimes S-shaped. There was no discernable micronucleus. E. trepida is a predator on the various hymenostomous ciliates of the algal mats. Locomotion is by a slow swimming movement in which the animal turns on its own axis. (ref. ID; 645)

Comments

This species was found by Kahl (1928) in the Oldesloe salt pools and described as Trachelocerca trepida. Borror (1965) places it in the genus Enchelyodon. (ref. ID; 645)