Main Content
< Top page

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Dissotrocha

Dissotrocha Bryce, 1910 (ref. ID; 7815, 7849)

Class Digononta: Order Bdelloidea: Family Philodinidae (ref. ID; 6806)

ref. ID; 1663

With a well-developed rostrum and corona, the latter always capable of being retracted into the mouth. With four plain toes, of which two are dorsal and two terminal. Cuticle coarse, with few or no transverse folds but often with few to many spines, or spines absent. Viviparous. (ref. ID; 1663)

ref. ID; 1923

Spurs several times as long as width at base. Mostly littoral, and in submerged Sphagnum. (ref. ID; 1923)

ref. ID; 3137

The foot is four-jointed, and it bears very large spurs. The wheel-organ is wide. The cuticle is stiff and a little flexible, only by Dissotrocha scutellata it forms a distinct armour. The number of the ventral ribs does not of exceed the number of the false trunk-segments. The eye-spots are cerebral, mostly they are only weakly developed, or they are completely absent. D.f.: 3/3. Viviparous. (ref. ID; 3137)

ref. ID; 7849

In the soil sample, there are several species belonging to the genus Dissotrocha. These animals have four toes. They have two eyes with colours from bright to dark red. The body is often covered with a cerebral semi-lorica with longitudinal sutures. The lorica may be covered with appendices which are hunch, hump or papilla shaped. The wheel organ is comparably small. The rostrum is covered with two lamellae. The dorsal antenna is long and sometimes divided at the top. The rounded trophi has 2-3 paired main teeth with attendant indistinct grooves. The spurs situated in front of the toes are either short and cone shaped or long and needle shaped. (ref. ID; 7849)
  1. Dissotrocha aculeata (Ehrenberg, 1832) (ref. ID; 1345, 1499, 1861, 1923, 2268, 2276, 2757, 2892, 3137, 3688) reported year? (ref. ID; 3523, 5022), aculeata aculeata (Ehrenberg, 1832) (ref. ID; 7849) reported year? (ref. ID; 4605)
    Syn; Dissotrocha aculeata Bryce, 1910 (ref. ID; 1345) or 1913 (ref. ID; 3137); Philodina aculeata Ehrenberg, 1832 (ref. ID; 1345, 2276, 2757, 2892, 3137, 3688); Philodina aculeata var. medio-aculeata Janson, 1983 (ref. ID; 3137), aculeata medioaculeata Janson, 1893 (ref. ID; 3688)
  2. Dissotrocha aculeata bjorki (Berzins, 1982) (ref. ID; 3508)
    Syn; Dissotrocha bjorki Berzins, 1982 (ref. ID; 3508)
  3. Dissotrocha aculeata crystalina Murray, 1908 (ref. ID; 2892) reported year? (ref. ID; 4605), var. crystallina Murray, 1908 (ref. ID; 1345)
  4. Dissotrocha aculeata decemcuspis Berzins, 1982 (ref. ID; 4605 original paper)
  5. Dissotrocha aculeata didyma Berzins, 1982 (ref. ID; 4605 original paper)
  6. Dissotrocha aculeata ecksteini Berzins, 1982 (ref. ID; 4605 original paper)
  7. Dissotrocha aculeata gossei Berzins, 1982 (ref. ID; 4605 original paper)
  8. Dissotrocha aculeata hebes Berzins, 1982 (ref. ID; 1499, 4605 original paper)
  9. Dissotrocha aculeata inserta Berzins, 1982 (ref. ID; 4605 original paper) reported year? (ref. ID; 1499)
  10. Dissotrocha aculeata macrostyla (Ehrenberg) (ref. ID; 4605)
  11. Dissotrocha aculeata markmani Berzins, 1982 (ref. ID; 4605 original paper)
  12. Dissotrocha aculeata medioaculeata (Jansen) (ref. ID; 4605), var. medio-aculeata Janson, 1893 (ref. ID; 1345, 3506)
  13. Dissotrocha aculeata milnei Berzins, 1982 (ref. ID; 4605 original paper)
  14. Dissotrocha aculeata multicollis Berzins, 1982 (ref. ID; 4605 original paper)
  15. Dissotrocha aculeata multiplicans Berzins, 1982 (ref. ID; 4605 original paper)
  16. Dissotrocha aculeata murrayi Berzins, 1982 (ref. ID; 4605 original paper)
  17. Dissotrocha aculeata octobullata Hauer, 1958 (ref. ID; 7849) reported year? (ref. ID; 4605), var. octobullata (ref. ID; 3506)
  18. Dissotrocha aculeata octocollis Berzins, 1982 (ref. ID; 4605 original paper)
  19. Dissotrocha aculeata quadricarinata Berzins, 1982 (ref. ID; 4605 original paper)
  20. Dissotrocha aculeata quadrispinosa Berzins, 1982 (ref. ID; 4605 original paper)
  21. Dissotrocha aculeata rachis Berzins, 1982 (ref. ID; 4605 original paper)
  22. Dissotrocha aculeata repanda Berzins, 1982 (ref. ID; 4605 original paper)
  23. Dissotrocha aculeata reversa Berzins, 1982 (ref. ID; 4605 original paper)
  24. Dissotrocha aculeata serangodes Berzins, 1982 (ref. ID; 4605 original paper)
  25. Dissotrocha aculeata simplex Berzins, 1982 (ref. ID; 4605 original paper)
  26. Dissotrocha aculeata tuberculata (Gosse) (ref. ID; 4605)
  27. Dissotrocha acuelata f. dukesi Russell (ref. ID; 2284 original paper)
  28. Dissotrocha bjorki Berzins, 1982 (ref. ID; 4605 original paper)
    See; Dissotrocha aculeata bjorki (ref. ID; 3508)
  29. Dissotrocha decembullata Koste, 1996 (ref. ID; 7849 original paper)
  30. Dissotrocha hertzogi Hauer, 1939 (ref. ID; 1345, 1487 original paper, 2266, 2887)
  31. Dissotrocha hertzogi aculeata Koste, 1996 (ref. ID; 7849 original paper)
  32. Dissotrocha macrostyla (Ehrenberg, 1838) (ref. ID; 1345, 1861, 1923, 2266, 2276, 2892, 3137, 3275, 3688) reported year? (ref. ID; 1450, 3523)
    Syn; Dissotrocha macrostyla Bryce, 1910 (ref. ID; 1345, 3137, 3688); Philodina macrostyla Ehrenberg, 1838 (ref. ID; 1345, 2276, 2892, 3137, 3275, 3688); Philodina pannosa Bailay, 1851 (ref. ID; 1345, 3688) or Bailey, 1851 (ref. ID; 3137); Philodina tuberculata Gosse, 1886 (ref. ID; 1345, 3137, 3688)
  33. Dissotrocha macrostyla hertzogi (Hauer, 1939) (ref. ID; 2892)
  34. Dissotrocha macrostyla tuberculata (Gosse, 1886) (ref. ID; 2892), f. tuberculata (ref. ID; 1450), var. tuberculata Gosse, 1886 (ref. ID; 3688) reported author and year? (ref. ID; 3137, 3397)
    Syn; Dissotrocha macrostyla var. tuberculata Bryce, 1910 (ref. ID; 3137); Philodina macrostyla var. tuberculata Murray, 1908 (ref. ID; 3137); Philodina tuberculata Gosse, 1886 (ref. ID; 3137)
  35. Dissotrocha pectinata (Murray, 1911) (ref. ID; 1345)
  36. Dissotrocha schlienzi Hauer, 1952 (ref. ID; 3125 original paper, 3508)
  37. Dissotrocha scutellata Bartos, 1950 (ref. ID; 1345, 3137)
  38. Dissotrocha spinosa (Bryce, 1892) (ref. ID; 1345)
    Syn; Callidina spinosa Bryce, 1892 (ref. ID; 1345); Dissotrocha spinosa Bryce, 1910 (ref. ID; 1345); Philodina spinosa Murray, 1908 (ref. ID; 1345)

Dissotrocha aculeata (Ehrenberg, 1832) (ref. ID; 1345, 1499, 1861, 1923, 2268, 2276, 2757, 2892, 3137, 3688) reported year? (ref. ID; 3523, 5022), aculeata aculeata (Ehrenberg, 1832) (ref. ID; 7849) reported year? (ref. ID; 4605)

Synonym

Dissotrocha aculeata Bryce, 1910 (ref. ID; 1345) or 1913 (ref. ID; 3137); Philodina aculeata Ehrenberg, 1832 (ref. ID; 1345, 2276, 2757, 2892, 3137, 3688); Philodina aculeata var. medio-aculeata Janson, 1983 (ref. ID; 3137), aculeata medioaculeata Janson, 1893 (ref. ID; 3688)

Descriptions

This species is easily recognized form the dorsal spines. All are characteristically dark red or brown. (ref. ID; 1499)

Variable number of cuticular spines (2-12); integument stiff; trunk yellow, grey or brownish; eyespots present; corona wider than head; trochus discs separated by wide sulcus; teeth 3/3. Mostly viviparous. (ref. ID; 2892)

The body is 350 to 460 µm long. It is whitish gray to brown. The cuticle is very stiff, with strong longish cuticular folds, on which are fixed the passively moving, long, and sharply pointed spines in a number from two to 12. The rostrum is long, strong with two large rostral lamellae. Under the rostral lamellae these are many short whirl-cilia and four long tactile setae. The dorsal antenna is club-shaped, and terminates in three brushes of sensitive setae. The eye-spots are distinctly developed. The foot is strong, four-jointed. The first foot-joint is the largest, the second joint is the shortest. On the third foot-joint the long stout spurs sit on pillow-shaped pedicels. The spurs are only slightly apart. The wheel-organ is a little wider than the head. The wheel-discs are far apart, and they are inclined somewhat to the ventral side of the body. This species is very variable as far as size, number and length of spines are concerned. The spines sit in six transversal rows, and they are backwards pointing in all rows with exception of the third row, whose spines point forwards. The odd spine sits in the median line of the body in the first transversal row of the spines. According to Petr many forms of this species live in Czechoslovakia, but, Petr does not describe any of them. I discovered only the forms with 8 and with 10 spines together in all rows. (ref. ID; 3137)

This brownish species feed only seldom and is mostly contracted. Sometimes, it creeps slowly on the ground. With regard to the number of spines on the body, different types have been mentioned (Murray 1980; Donner 1965:184). The Etosha-type carries commonly 19 spines (4+4+4+5+2). The flank section has a deep notch and ends in long sickle-shaped thorns. The spurs (Fig.5) are short. The species is cosmopolitan. (ref. ID; 7849)

Examined materials

A soil sample out of a dried rockpool (lithotelma) on a dolomit hill in the Etosha National Park, N-Namibia, South Africa. (ref. ID; 7849)

Measurements

Length 350-500; trophi 30-42; spines -30 µm. (ref. ID; 2892)

Total length 500 µm without protruded wheel organ 350 µm. (ref. ID; 7849)

Dissotrocha acuelata f. dukesi Russell (ref. ID; 2284 original paper)

Descriptions

The general characteristics of this form are those of Dissotrocha aculeata except that on the anterior potion of the body section are two large robust forward pointing lateral spines, broadly based, and reinforced by a membranous ridge which extends from near the median line on the ventral side of the body. The body has no other spines and with the exception of the head section, which is almost opaque, the body is hyaline. The spurs are long and incurved. (ref. ID; 2284)

Comments

This form was collected by Mr. W. Dukes from pools in the high country near Buller. The specimens were found in a fully extended condition amongst preserved material, and it was considered that they were washed from mosses into the pools and had died before the preservative was added. (ref. ID; 2284)

Measurements

Total length 410; length of spurs 42; length of lateral spines from base 30 µm. (ref. ID; 2284)

Dissotrocha decembullata Koste, 1996 (ref. ID; 7849 original paper)

Descriptions

The spines are deformed to hunch or papilla shaped appendices. As early as in 1908 Murray described a bdelloid rotifer which he called Philodina aculeata var. It had 8 hunches on the dorsal body. In wet sphagnes, Hauer (1958) also found some animals with eight hunches. He described them as Dissotrocha aculeata var. octobullata n. var. This variety Donner (1965: 184) changed into D. acuelata octobullata Hauer (1958). I thick it is a defferent species. In the Etosha-sample, there are some Dissotrocha-types similar to D. octobullata, however, they carried 10 large appendices, which were pointed in the juvenile animals (Fig.6b). The adult animals had huge, wing-like appendices ending in small sectioned, rod shaped parts. These rotifers were very vivid and their soft, easily deformable appendices enabled them to creep very quickly into narrow spaces under the cover glass. Their wheel organ was conspicuously small. Two cerebral eyes had tiny red pigments. (ref. ID; 7849)

Examined materials

A soil sample out of a dried rockpool (lithotelma) on a dolomit hill in the Etosha National Park, N-Namibia, South Africa. (ref. ID; 7849)

Measurements

Total length of adults 320-400 µm. (ref. ID; 7849)

Dissotrocha hertzogi aculeata Koste, 1996 (ref. ID; 7849 original paper)

Descriptions

So far, different types of the genus Dissotrocha carrying long spurs have only been known without body hooks or similar appendices, e.g. Dissotrocha macrostyla Ehrenbreg (1938) and also the rare D. hertzogi Hauer (1939) (Fig.7d-e, 8). In the soil sample from Etosha, there was an animal, very similar to D. hertzogi, with very long, thin spurs of 80 µm length. They were not bent inwards but were straight with long points. The creeping animal was approx. 440 µm long. On the lower part of the body, there were four caudally curved thorns. I assume, since there is a large variablity within the genus, this animal belongs to D. hertzogi. Every now and then, when this new form rotates the wheel organ, the dorsal antenna and the cerebral eyes of the type could be seen. The trophi is relatively small (25 µm) and has three paired main teeth. The animal has four toes. The ventral ones are longer and stronger than the dorsal. (ref. ID; 7849)

Examined materials

A soil sample out of a dried rockpool (lithotelma) on a dolomit hill in the Etosha National Park, N-Namibia, South Africa. (ref. ID; 7849)

Dissotrocha macrostyla (Ehrenberg, 1838) (ref. ID; 1345, 1861, 1923, 2266, 2276, 2892, 3137, 3275, 3688) reported year? (ref. ID; 1450, 3523)

Synonym

Dissotrocha macrostyla Bryce, 1910 (ref. ID; 1345, 3137, 3688); Philodina macrostyla Ehrenberg, 1838 (ref. ID; 1345, 2276, 2892, 3137, 3275, 3688); Philodina pannosa Bailay, 1851 (ref. ID; 1345, 3688) or Bailey, 1851 (ref. ID; 3137); Philodina tuberculata Gosse, 1886 (ref. ID; 1345, 3137, 3688)

Descriptions

The animals were commonly covered with secretion in which different kinds of detritus had got caught. In certain individuals, the rows of closely packed rods described and drawn by Voigt (1904, p.14 and Pl.2:8; "Philodina tuberculata Gosse") could be observed. On the other hand the cuticular formations were never plates of the type seen by Bartos (1951, p.406 and Fig.45E). The structure Pejler observed was not equally distinct in all the individuals. At times it covered only certain parts of the body. For these reasons Pejler is inclined to agree with Murray (1908), who sees no justification for classifying the tuberculate form as a separate species, but instead, considers it a variety. Since the latter conception has now been eliminated from zoological taxonomy the correct name of the form must be Dissotrocha macrostyla f. tuberculata. (ref. ID; 1450)

This species is a cosmopolitan species found in mosses and in the littoral zone of ponds and lakes. (ref. ID; 1861)

Cuticle smooth, occasionally covered with small rod- or disk-shaped secretion deposits in direction of cuticular folds; 2 elongated cerebral eyespots; rostrum with lamellae; teeth 3/3; spurs moderately long and pointed, knobby thickening at base. (ref. ID; 2892)

The whitish to slightly yellow-brown body is 363 to 476 µm long, the trunk is stick, and it is covered with the most varied kind of detritus. The wheel-organ is broad, the wheel-pedicels are separated by a wide and deep sulcus, the wheel-discs are somewhat inclined towards the ventral side of the body, and are provided with very long wheel-cilia. The upper lip lies far forwards and it is flatly obliquely arched. The rostrum is cylindrical with four strong, S-likely curved tactile setae besides a multitude of long wheel-cilia. The dorsal antenna is long, apparently four-jointed and the tip of it is club-shaped swollen. The eye-spots are very weakly developed, so that they are easily overlooked, very often the eye-spots are completely lacking. The foot is strong, four-jointed, and with long spurs. The spurs are two and half to three-times as long as the joint to which they are fixed. The spurs sit on large pillow-shaped extensions, and they narrow gradually towards the tip to a sharp point. D.f.: 3/3. (ref. ID; 3137)

Measurements

Length 435-476; spurs 39-46 µm. (ref. ID; 2892)

Dissotrocha macrostyla hertzogi (Hauer, 1939) (ref. ID; 2892)

Measurements

Length 600; trophi 30; spurs 83-97 µm. (ref. ID; 2892)

Dissotrocha macrostyla tuberculata (Gosse, 1886) (ref. ID; 2892), f. tuberculata (ref. ID; 1450), var. tuberculata Gosse, 1886 (ref. ID; 3688) reported author and year? (ref. ID; 3137, 3397)

Synonym

Dissotrocha macrostyla var. tuberculata Bryce, 1910 (ref. ID; 3137); Philodina macrostyla var. tuberculata Murray, 1908 (ref. ID; 3137); Philodina tuberculata Gosse, 1886 (ref. ID; 3137)

Descriptions

See description of D. macrostyla. (ref. ID; 1450)

The individuals are covered on the surface of the trunk with mucus, which forms a plate-armour of yellow-brown, very thick and regularly arranged plates; they were once considered as good species, but as their body is the size completely identical with Dissotrocha macrosytla Ehrenberg, they can at most be considered only a variety of this species. (ref. ID; 3137)

Measurements

Length 600; spurs 43 µm. (ref. ID; 2892)

Dissotrocha scutellata Bartos, 1950 (ref. ID; 1345, 3137)

Descriptions

The surface of the body is smooth, but the cuticle is much stiffer than in all known species of this genus. The digestive tract and the ovaries are vividly red, the body is opaque. On the dorsal side of the trunk are 6 pairs of very stiff, longish cuticular ribs. On the ventral side of the trunk are some very stiff transversal ribs. The body of this species is very similar to that of the species of the genus Pleuretra. The very well developed eye-spots on the brain and the smaller number of the transversal ridges on the ventral side of the trunk show that it is a true Dissotrocha species. The rostrum is long and slender, two-jointed. It bears two semicircular rostral lamellae. The first neck-segment bearing dorsal antenna is short. The second neck-segment is strikingly broad, it is much broader than the head of the creeping animal. The trunk is much more slender than this second neck-segment. The posterior border of the third to sixth trunk-segment is on its lateral and dorsal sides especially on the ventral edges projected in ring-shaped collars. The largest collar is on the posterior border of the sixth trunk segment. This forms a sheath, in which the foot is retracted. It seems that this collar serves in anabiosis to the adhesion of the animal to its support. The foot is four-jointed. The third foot-joint bears the spurs, these are slender, sharp and long. They are very far apart. The spurs sit on distinctly developed knobs on the posterior border of the third foot-segment. The foot terminates in four toes. The dorsal toes are smaller than the ventral ones. The dorsal antenna is very long. On either side of the base of the antenna sits a well developed lateral knob. In the creeping action the animal very often retracts the head and the neck in the anterior trunk part, and then only the end of the dorsal antenna and the rostrum can be seen. On both parts of the head very mobile moving-cilia can be seen. The eye-spots are close together, and they have the shape of a transversal line. Very often they are scarcely visible, but they are always developed. The wheel-organ is very broad, much broader than the head. On the wheel-discs distinct sensitive papillae are developed, bearing sensitive setae. The sulcus between the wheel-pedicels is very deep and wide. The upper lip is flatly arched and the anterior broader is without lobes. D.f.: 3/3 as is usual by the Dissotrocha species. According to all its features this species belongs to the genus Dissotrocha, but I have not had occasion to a certain the viviparity of this species. (ref. ID; 3137)

Measurements

The length of the body is 230-245 µm. (ref. ID; 3137)