algal bloom




Examples of Oscillatoria

oscillatoria at 400x magnification

400X total magnification; 20 μm scale bar.

Verona Park oscillatoria at 400x magnification

400X total magnification.

Verona Park oscillatoria at 400x magnification photo two

400X total magnification.


Trichomes rarely solitary; usually in smooth macroscopic mats. Trichomes straight to slightly waved, sometimes slightly coiled near the ends; cylindrical and isopolar; mostly >6.8 μm wide, and up to 70 μm wide; constricted or unconstricted at crosswalls. Trichomes typically without sheaths; sheaths only occasionally present in response to environmental stress. Trichomes are motile, with gliding or oscillating movement. Cells short, discoid (coin-like shape); cell length is always less then one-half the cell width, and cells are usually 3-11 times shorter than they are wide. Cell content homogeneous or with large granules; without aerotopes. Apical cells may be rounded, capitate, bluntly pointed, elongated, bent; with or without calyptra; with or without a thickened outer wall. Trichomes disintegrate into hormogonia, with formation of necridia.


Mainly benthic, forming mats on various substrata in shallow waters, swamps, and marshes. Common species are found in lakes, ponds, pools, and slow-flowing rivers, growing among algae or on muddy and sandy subtrates.


  • Johansen, J. R., & Komárek, J. (2015). Filamentous Cyanobacteria. In J. D. Wehr, R. G. Sheath, & J. P. Kociolek (Eds.), Freshwater Algae of North America: Ecology and Classification (2nd ed., pp. 162-179). Waltham, MA: Elsevier.
  • Komárek, J. & Anagnostidis, K. (2008). Cyanoprokaryota-2. Teil/Part 2: Oscillatoriales. In B. Büdel, G. Gärtner, L. Krienitz, & M. Schagerl (Eds.), Süßwasserflora von Mitteleuropa (Vol. 19/2, pp. 574-576). Heidelberg, Germany: Spektrum.