Anoplophrya lumbrici (Schrank, 1803)

Obert, Tomáš & Vďačný, Peter, 2019, Integrative taxonomy of five astome ciliates (Ciliophora, Astomatia) isolated from earthworms in Central Europe, European Journal of Taxonomy 559, pp. 1-37 : 15-18

Anoplophrya lumbrici (Schrank, 1803)

Figs 8 , 9

Description

The body size is about 50–120 × 35–100 µm, with an average of 90 × 60 µm. The shape is broadly elliptical to elliptical with both ends rounded. The cell is distinctly dorsoventrally flattened ( Figs 8A , E–I, 9A–B, D).

The nuclear apparatus consists of a single macronucleus and a single micronucleus. The macronucleus begins about 11 µm away from the anterior body end and extends through the cell’s midline. The size of macronucleus varies from about 30–95 × 5–15 µm, with an average of 72 × 9 µm. The macronuclear surface is smooth to slightly irregular. In dying cells, the macronucleus diminishes in size leaving behind a conspicuous hyaline envelope. The macronucleus sometimes also fragments within the envelope in postmortem cells. The micronucleus is situated conspicuously far away from the macronucleus, namely, near the middle of the left body margin and always opposite to the row of contractile vacuoles. The micronucleus is globular and approximately 5 µm in diameter ( Figs 8A , D–I, 9A–D).

There is only a single row of contractile vacuoles extending along the right cell margin. The number of vacuoles is three or four and their size ranges from 4 to 11 µm in diastole. A contractile vacuole originates by fusion of three to five vesicules ( Figs 8A , E–F, H–I, 9A–B, D). The cytoplasm is colorless and contains innumerable granules being about 1.5 µm across. The cortex is semi-rigid and without specific granules. Swims moderately fast by rotation about the main body axis.

The somatic ciliature is holotrichous and composed of meridionally extending kineties over both cell sides. The number of ventral kineties varies from 30 to 50, averaging at 42. The number of dorsal kineties almost matches the number on the ventral side (30–51, on average 43). Somatic kineties are composed of very densely arranged basal bodies, i.e., intrakinetal distance is only 1.3 µm ( Figs 8A , 9B ). There is an apical and a terminal suture at the anterior and the posterior pole where individual somatic kineties begin and terminate, respectively ( Figs 8 B–C, 9E).

Occurrence

Anoplophrya lumbrici was recorded only in the anecic L. terrestris at three localities: gardens at the Šúrska ulica street in Rendez and at the Jakubská ulica street in Rača as well as in floodplain soils in a riparian, willow-poplar forest near the Karlova Ves branch of the Danube River ( Table 2 ). Ciliates were typically isolated from the middle part of the gastrointestinal tract, although very rarely some specimens were recorded also below this gut region.

Figures

Fig. 8. Anoplophrya lumbrici (Schrank, 1803), Slovak specimens in vivo. A. Semi-schematic diagram of the ventral side, showing the nuclear apparatus, the arrangement of contractile vacuoles (arrowheads) and the somatic ciliary pattern. B–C. Details of the anterior and posterior body pole, showing the apical and the terminal suture. D. In dying cells, the macronucleus diminishes in size leaving behind a conspicuous hyaline envelope. The macronucleus sometimes also fragments within the envelope in postmortem cells. E–I. Variability of body shape and size as well as of the contractile vacuole and nuclear apparatus. The micronucleus is situated conspicuously far away from the macronucleus, namely, near the middle of the left body margin and always opposite to the row of contractile vacuoles. Drawn to scale. Scale bars: A, E–I = 50 µm; D = 20 µm.

Fig. 9. Anoplophrya lumbrici (Schrank, 1803), Slovak specimens in vivo. A, D. Optical sections, showing the general body organization. The body is elliptical with both ends rounded. The macronucleus is rodlike and extends through the cell’s midline. The micronucleus is situated conspicuously far away from the macronucleus, namely, near the middle of the left body margin and always opposite to the row of contractile vacuoles (arrowheads). B. Ventral view, showing the somatic ciliary pattern. Arrowheads denote the contractile vacuoles which originate by fusion of three to five vesicules. C. In dying cells, the macronucleus diminishes in size leaving behind a conspicuous hyaline envelope. The macronucleus sometimes also fragments within the envelope in postmortem cells. E. Frontal view, showing the apical suture. Scale bars: A–B, D = 50 µm; C, E = 20 µm.