Genus: Highly flattened; pellicle firm; body form constant (Kudo, 1966).
Chloroplasts small, discoid, pyrenoids usually absent; most species flat and leaf-shaped;
often with ridges or fins running helically or longitudinally (Illustrated Guide, 1985).
Species: 80-100 μm; similar to P. longicauda; twisted 40-60 degree (How to know the protozoa, 1979). Var. tortuosa: twisted about 90 degree. |
Images of collecting locality:
Lake Biwa near Biwako Museum, Kusatsu city, Shiga Pref., Japan, June 29, 2008, by Y. Tsukii