Pleuronema setigerum Calkins, 1902

Fig. 4 J–N, Table 1

Description

Description of present specimens: Size in vivo 50–70 × 25–35 μm, slender oval in outline, widest at ⅓ posterior end of body (Fig. 4 J–L). Ventral side almost flat, dorsal side conspicuously convex. Buccal field 80% of body length (Fig. 4 J–L). Extrusomes 4–5 μm long, closely beneath pellicle. Cytoplasm colourless to grayish containing numerous granules (3–6 µm across) and cytoplasmic crystals of varying size and shape (Fig. 4 J–L). One spherical macronucleus. Thirteen to 15 elongated caudal cilia about 25 μm in length (Fig. 4 J–L). Locomotion by swimming while rotating on main body axis, or briefly lying motionless on debris. Twelve to fifteen somatic kineties. Five preoral kineties to left of buccal field (Fig. 4 M–N). Oral apparatus similar to congeners: M1 with one short and two longer rows; M2a mostly two-rowed but with a middle section that is single-rowed in a ‘zigzag’ pattern, with its posterior end characteristically ring-like. M2b V-shaped, distinctly separated from M2a; M3 three-rowed (Fig. 4 M– N). PM 80% of body length.