DENNIS KUNKEL MICROSCOPY / SCIENCE PHOTO LIBRARY DENNIS KUNKEL MICROSCOPY / SCIENCE PHOTO LIBRARY
Scanning electron micrograph (SEM) of Scenedesmus sp., flat colony of 4 alga cells. Scenedesmus, a green alga from the Chlorophyceae group, is a small, non-motile, colonial green alga consisting of cells aligned in a flat plate. The colonies most often have two or four cells, but may have 8, 16, or 32 cells. The cells are usually cylindrical but may be more crescent-shaped, ovoid, or fusiform (wide in the middle, tapering at both ends). Often the end cells each have two long spines protruding from their outer corners. Other cells may have additional spines or chitinous bristles. Each cell contains a single parietal, plate-like chloroplast with a pyrenoid (the site of CO2 fixation). The cell walls may be covered in bumps or reticulations. Scenedesmus is a photosynthetic planktonic organism that is important in the aquatic food chain. Magnification: x1,200 when shortest axis printed at 25 millimetres.
Model release not required. Property release not required.