Relations between some Cochliopodium species – simplified after Geisen et al., 2014.
Cochliopodium plurinucleolum Geisen et al., 2014
Diagnosis: Length in locomotion 8.8–16.4 µm (mean 12.0 µm), breadth 10.2–14.8 µm (mean 12.0 µm), length : breadth ratio 0.7–1.3 (mean 1.0); locomotive form variable, sometimes oval, triangular, fan-shaped, round or crescent-shaped; thin, hyaloplasmic veil surrounding the remaining cell smooth or slightly irregular; hyaloplasm only in fast directed locomotion reduced in the posterior and sometimes replaced by one or more short trailing filaments; no sub-pseudopodia; one single spherical nucleus,2.2–4.0 µm diameter (mean 3.4 µm) with one or more small, peripheral nucleoli ranging in diameter from 0.6 to 1.2 µm (mean 1.0 µm). Stable double-walled cysts formed in older cultures. Scales made up of a circular, grid-like base plate with the mesh size of 0.015 µm, 4 stalks attached to the base plate converging towards a funnel-shaped apical part consisting of ca. 15 radial spokes with very fine,poorly discernible concentric filaments between them. Diameter of a base plate 0.465-0.76 µm (average 0.627 µm), of the apical part, 0.445-0.577 µm (average, 0.5 µm), height of a scale 0.185-0.3 µm (average, 0.25 µm).
Ecology: Observed habitat: Grassland soil on Sardinia, Italy;
Differential diagnosis: Due to its unique nuclear structure, C. plurinucleolum is only comparable to C. clarum Schaeffer, 1926. However, it differs from this species in being smaller, having a more irregular outline, and inhabiting soils in contrast to marine habitats.