Choose which general growth type–coccoid or filamentous–describes your cyanobacterial specimen. To help you understand what these terms mean, each option is accompanied by a text description and photographic examples. Choose either Coccoid or Filamentous below to proceed to the next step.
Coccoid cyanobacteria exist as solitary cells, as irregular agglomerations of cells, or as distinct colonies of cells. Cells vary in shape, but are generally “rounded” in nature: spherical, oblong, rod-shaped, and hemispherical are some examples.
Filamentous cyanobacteria form chains, or “filaments,” of cells that are connected end-to-end. The width and length of these filaments varies widely; the filaments can be perfectly straight to corkscrew-like coiled; and they may be solitary or gathered into masses of many filaments. Individual cells within the filaments can also take on a variety of different shapes and sizes.