Uronemita filificum Kahl, 1931

Fig. 4A–E; Table 1

Description

Description based on Alabama population: body 30–45 × 15–20 μm in vivo, inverted pear-shaped with large, conspicuous apical plate (Fig 4A–B). Dorsal side conspicuously convex. Length of buccal field 60% of body. Extrusomes appromately 2 µm long, rod-shaped, closely beneath pellicle. Cytoplasm colourless to grayish, containing several (ca 3 μm across) food vacuoles and dumbbell-shaped crystals (ca 1–2 µm long) often concentrated in anterior end of body (Fig. 4C). Single macronucleus larg (Fig. 4E). Locomotion by swimming aimlessly, sometimes rotates while attached to substratum by caudal cilium. Eighteen or 19 somatic kineties, anterior third of each composed of dikinetids (Fig. 4E). M1 single-rowed with five or six kinetosomes (Fig. 4D); M2 three-rowed; M3 smaller and close to M2 (Fig. 4D). PM on right of shallow buccal cavity, with zigzag row of basal bodies, extending anteriorly to the middle of M2. Scutica consisting of three or four basal body pairs (Fig. 4D).