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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Eosphora

Eosphora Ehrenberg, 1830 (ref. ID; 1345) or 1930 (ref. ID; 2017)

ref. ID; 1663

Foot segmented. Each uncus with a single simple tooth. Retrocerebral sac present. Rami bent at right angles and with one or two teeth at midlength and many small ones more distally. Toes separate. Total length 300 to 500 µm long. Littoral species. (ref. ID; 1663)

ref. ID; 1923

Uncus has 1 principal tooth without preuncial teeth. Fulcrum short, and broad. Both sac and glands present. (ref. ID; 1923)

ref. ID; 1931

Spindle shaped illoricate rotifers with long tubular foot and short toes; salivary glands asymmetric, the right larger than the left and gastric glands round. Mastax virgate. (ref. ID; 1931)

ref. ID; 3245

Notommatid rotifers with fusiform, illoricate body, nearly cylindric anteriorly and tapering to a distinct tail; the foot is usually tubular and moderately long; the two toes are short. The corona is frontal, with a marginal wreath and a lateral, inner arc of cilia jointed to it and simulating auricles; the mouth is at the ventral margin of the buccal field and the intra-marginal ciliation has largely disappeared. The mastax is virgate, but the pumping action had been partly lost; the fulcrum is short and very broad; the rami are triangular and bent at a right angle near mid-length, where one or two large, blunt teeth are usually present; the unci have a single, very large tooth, adapted to prehension; a rudimentary epipharynx is usually present. There are two salivary glands, the right much larger than the left and frequently curving under the fulcrum. The retrocerebral organ is small, but both sac and glands are present. The eyespot is cervical, at the posterior end of the ganglion; two accessory frontal eyespots are found in some species. The genera Eothinia and Resticula are very closely related to Eosphora, but seem to form natural groups with the included species agreeing in so many important characters (corona, mastax, retrocerebral organ, form of body, etc.), that generic separation appears advisable. (ref. ID; 3245)

ref. ID; 3334

A small genus of illoricate notommatid rotifers in which the mastax is not removed from the corona. The retorocerebral organ has both a sac and glands (cf. Resticula). The mastax has modified virgate trophi. The unci usually have one principal tooth. E. najas has at least two. The foot is well-developed and carries two short, strong toes. (ref. ID; 3334)
  1. Eosphora anthadis (Harring & Myers, 1922) (ref. ID; 1847, 1923, 2017, 2797, 2809, 7846) or 1921 (ref. ID; 1931) reported year? (ref. ID; 3403)
  2. Eosphora aurita Werneck, 1836
    See; Dicranophorus auritus Ehrenberg (ref. ID; 2276), Itura aurita (ref. ID; 1345, 2757, 3688)
  3. Eosphora canicula Iroso, 1913
    See; Itura aurita (ref. ID; 1345, 3688)
  4. Eosphora digitata Ehrenberg, 1838 (ref. ID; 1345) or reported year? (ref. ID; 3217)
    See; Eosphora najas (ref. ID; 1345, 2757)
  5. Eosphora ehrenbergi Weber, 1918 (ref. ID; 1345, 2757, 7846) reported year? (ref. ID; 3523), Weber & Montet, 1918 (ref. ID; 3688) reported year? (ref. ID; 2936) or (Ehrenberg, 1832) (ref. ID; 2017)
    Syn; Eosphora ehrenbergi Weber, 1918 (ref. ID; 1345) or Weber & Montet, 1918 (ref. ID; 2017, 3688); Furcularia najas Dujardin, 1841 (ref. ID; 1345, 3688); Notommata najas Ehrenberg, 1832 (ref. ID; 1345, 2017, 2757, 3217, 3688); Notommata najas thermalis Issel, 1906 (ref. ID; 1345, 3688); Notommata potamis Gosse, 1887 (ref. ID; 3688)
  6. Eosphora elongata Ehrenberg
    See; Eothinia elongata (ref. ID; 1345, 2017, 3688)
  7. Eosphora gelida Harring & Myers, 1922
    See; Resticula gelida (ref. ID; 1345, 2017, 3245, 3688)
  8. Eosphora melandocus Harring & Myers, 1922 or (Gosse) Harring & Myers, 1921
    See; Resticula melandocus (ref. ID; 1345, 2017, 3245, 3271, 3688)
  9. Eosphora naias Ehrenberg (ref. ID; 2196, 2933)
  10. Eosphora najas Ehrenberg, 1830 (ref. ID; 1345, 1931, 2017, 2757, 3028, 3271, 3688, 7846) reported year? (ref. ID; 2196, 2890, 3027, 3334, 3523, 5022) reported author and year? (ref. ID; 7065)
    Syn; Eosphora digitata Ehrenberg, 1838 (ref. ID; 1345, 2757, 3688); Eosphora najas Ehrenberg, 1830 (ref. ID; 1345); Furcularia digitata Dujardin, 1841 (ref. ID; 1345, 3688); Furcularia najas Dujardin, 1841 (ref. ID; 1345, 3271, 3688); Notommata eosphora Bartsch, 1870 (ref. ID; 1345, 3271, 3688)
  11. Eosphora striata Glascott, 1893
    See; Eothinia elongata (ref. ID; 1345, 3688)
  12. Eosphora therina Harring & Myers, 1922 (ref. ID; 1345, 2017)
  13. Eosphora thoa Harring & Myers, 1924 (ref. ID; 1345, 2017, 3245 original paper, 7846)
  14. Eosphora thoa var. thoides Wulfert, 1935 (ref. ID; 3688)
    Syn; Eosphora thoides Wulfert, 1935 (ref. ID; 3688)
  15. Eosphora thoides Wulfert, 1935 (ref. ID; 1345, 2017)
    See; Eosphora thoa var. thoides Wulfert, 1935 (ref. ID; 3688)
  16. Eosphora viridis Stenroos, 1898
    See; Itura viridis (ref. ID; 1345, 3688)

Eosphora anthadis (Harring & Myers, 1922) (ref. ID; 1847, 1923, 2017, 2797, 2809, 7846) or 1921 (ref. ID; 1931) reported year? (ref. ID; 3403)

Descriptions

This is being reported for the first time from India. Body is broad and transparent with soft integument, short distinct head and large abdomen. Foot without joints but wrinkled. Toes short and conical in appearance laterally. Trophi consist of triangular and symmetrical rami, unci with single tooth, fulcrum broad and manubrium straight with anterior expansions. Foot glands large ending in a reservoir at the base of toes. (ref. ID; 1931)

The length of living animals has been reported to lie between 350-400 µm (Harring & Myers; Donner 1975). Our contracted specimens measured between 180-216 µm. The trophi is very small (33-35 µm) and slightly different from the virgate type. The spherical rami are characteristic, and have a interior denticulate membrane which probably has a pumping function. The unci have only a single, slightly curved tooth. The manubria have a nearly triangular lamella on the anterior end. The end of the fulcrum has a rough surface for attachment of the mastax muscles. The gastric glands are very big as are the foot glands. The salivary glands were not observed. The foot is wrinkled and has paired toes with separate claws. (ref. ID; 2809)

Measurements

Total length 336; width 126; toes 14; trophi 28 µm. (ref. ID; 1931)

Eosphora najas Ehrenberg, 1830 (ref. ID; 1345, 1931, 2017, 2757, 3028, 3271, 3688, 7846) reported year? (ref. ID; 2196, 2890, 3027, 3334, 3523, 5022) reported author and year? (ref. ID; 7065)

Synonym

Eosphora digitata Ehrenberg, 1838 (ref. ID; 1345, 2757, 3688); Eosphora najas Ehrenberg, 1830 (ref. ID; 1345); Furcularia digitata Dujardin, 1841 (ref. ID; 1345, 3688); Furcularia najas Dujardin, 1841 (ref. ID; 1345, 3271, 3688); Notommata eosphora Bartsch, 1870 (ref. ID; 1345, 3271, 3688)

Descriptions

Shape of the body constant. Head, neck and abdomen marked by transverse folds. Abdomen oval with posteriorly rounded trail. Foot cylindrical and indistinctly three jointed. Toes straight ending in points. Mastax consists of triangular and symmetrical rami, posteriorly rounded broad fulcrum and manubria with thin anterior lamella narrowing posteriorly ending in round knob. Foot glands club shaped and long. (ref. ID; 1931)

The foot is composed of three segments. E. najas is predatory and the trophi are modified for seizing its prey. A single, large, red, cerebral eyespot is present. (ref. ID; 3334)
  • Egg: The eggs are large, brown and oval (90 µm by 65 µm). (ref. ID; 3334)

    Trophi: SEM photograph. (ref. ID; 7065)

    Measurements

    Total length 336; trophi 42; toes 28 µm. (ref. ID; 1931)

    It is a very large rotifer (in excess of 600 µm) though it was very difficult to measure accurately. Living specimens tended to be elongated when held in compression, while mounted specimens tended to be foreshortened. Typical measurements were: body length 342 µm, foot length 79 µm, toe length 50 µm, total length 471 µm. From the upper surface of the unci to the tip of the fulcrum the trophi measured 82 µm. The rami measured 39 µm, manubria 49 µm and fulcrum 43 µm. (ref. ID; 3334)

    Eosphora thoa Harring & Myers, 1924 (ref. ID; 1345, 2017, 3245 original paper, 7846)

    Descriptions

    The body is broad and very robust; its greatest width is one third of the total length. The integument is very flexible and the animal highly contractile. The entire body is hyaline. The head and neck segments are fused and separated from the abdomen by a well marked constriction; the corona is as wide as the body as its widest point. The abdomen tapers gradually from a point near mid-length to the base of the foot, and ends in a broad, but not very prominent tail. The foot is conical and very stout; it is without joints, but irregularly wrinkled. Its length is about one fourth of the entire length. The two toes are heart-shaped in dorsal view, ending in very fine points; the ventral edge is straight, while the dorsal is strongly curved; their length is about one fifteenth of the total length. In young animals the abdomen is faintly striate or plicate dorsally. The corona is frontal and consists of a marginal wreath of cilia, interrupted dorsally and passing in a curve to the lateral angles where it is joined by an inner arc, starting also from the dorsal gap; from the angles the corona continues as a single band, closed ventrally and passing immediately below the mouth. The buccal field is evenly ciliate. On the apical plate are two large papillae, each with a tuft of sensory setae. There is no indication of the accessory eyespots usually present on these papillae in other species of this genus. The dorsal antenna is on the posterior portion of the head segment, just in front of the transverse neck fold; the distance from the neck to the lateral antennae is about two thirds of the length of the abdomen. The mastax is of a modified virgate type, in which the pumping action has become subordinate and the trophi adapted to the seizure of prey by prehension. The fulcrum is very short and broad. The rami are elongate, roughly triangular and strongly curved longitudinally; near the base there is a very large apophysis, projecting as a double spur towards the ventral side. The inner edges of the rami have near mid-length a blunt tooth, interlocking with is mate on the opposite side; immediately front of this tooth there are some faint denticulation, and nearer the base a strong transverse rib forms a slightly projecting knob. The posterior half of the rami are armed with about twenty small, conical teeth, separated by relatively large interspaces. The unci have a single, very robust, clubshaped ventral tooth, which is connected to the upper end of the manubrium by an excessively thin lamella of irregular outline. The central section of the manubrium is nearly parallel-sided and slightly curved the basal plate is triangular. The epipharynx consists of two symmetrical, roughly L-shaped pieces, imbedded in the walls of the mastax; the shorter branch is directed diagonally outwards and towards the ventral side; the longer, broadly expanded posteriorly, is nearly parallel to the longitudinal axis of the mastax. The epipharynx has been turned through an angle of approximately 90 degrees in figure 5, to avoid obscuring the form of the rami; it is consequently somewhat foreshortened, and its true length is shown in figure 4. The right lobe of the mastax is considerably larger than the left; this condition usually indicates the presence of a salivary glands, but there are no structural remains of it. The oesophagus is relatively short. The gastric glands are very large and rounded. There is no constriction between the stomach and intestine. The nuclei of the ovary are unusually large and irregular in outline; they appear to have separate yolk-masses. The bladder is normal. The foot glands are nearly cylindric and as long as the foot itself; they discharge into a minute spherical mucus reservoir at the base of the toes. The ganglion is large and saccate. The retrocerebral organ consists of a small, vacuolate sac and two very small subcerebral glands. The eyespots is large and at the posterior end of the ganglion. (ref. ID; 3245)

    Comments

    In external appearance it resembles E. anthadis so closely that it is virtually impossible to separate them. However, their behavior is very different; E, anthadis is a very slow swimmer and generally sluggish in its movements, while E. thoa swims very fast and is constantly changing its direction. The eyespot is sufficient to distinguish the species, and the trophi show but slight resemblances. It should be noted that E. anthadis is found only in moderately hard waters, while E. thoa occurs only in very soft water, so that there is really no great danger of confusion. (ref. ID; 3245)

    Type locality

    Eosphora thoa is rare; we have found only a few specimens in "Cemetery pond", near Eagle River, Vilas County, Wisconsin, and at Bargaintown, near Atlantic City, New Jersey. (ref. ID; 3245)

    Measurements

    Total length 300-500; toes 20-35; trophi 50 long, 60 µm wide. (ref. ID; 3245)