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: Cell body 100-115 μm long,m, 70-80 μm wide (Ciugulea I. & Triemer R.E., A Color Atlas of Phtosyntetic Euglenoids, Michigan State University Press, 2010).
Similar species -->> P. acuminatus;
P. gigas
106 x 84 μm
Uruguay, 1999
P. gigas
130 x 88 μm
Mizumoto Park
Katsushika-ku
Tokyo, 2006
P. gigas
μm
Tonbo-no-numa
Isumi
Chiba, 2007