Species: Trichome straight, but slightly curved at terminals, both ends rounded,
8.5-9 μm wide, L/W=0.3-1.0; septum not constricted, granules present along septum
(Illustrations of The Japanese Fresh-water Algae, 1977).
Oscillatoria nigra Vaucher ?,
cell body 3-6 μm long, 7 μm wide, L/W=0.4-0.9,
x 640, Watarase river, Ashikaga city, Tochigi Pref., Japan, February 1, 2004 by Y. Tsukii
31 μm
63 μm
94 μm; x 640