Genus: Trichome without mucous sheath; straight, long, consisting of numerous cells (Illustrations of The Japanese Fresh-water Algae, 1977). Species: Trichome straight or slightly curved, without constriction at cell-cell junction, 2-3 μm wide; cell-body length nearly the same as its width (Illustrations of The Japanese Fresh-water Algae, 1977).

31 μm 63 μm 94 μm; x 640

Oscillatoria planctonica Woloszynska, cell body 2 μm long, 2 μm wide, x 640, Numappara marsh, Nasu-shiobara city (formerly Kuroiso city), Tochigi Pref., Japan, August 2003 by Y. Tsukii
31 μm 63 μm 94 μm; x 640