STEVE GSCHMEISSNER / SCIENCE PHOTO LIBRARY STEVE GSCHMEISSNER / SCIENCE PHOTO LIBRARY
Selection of diatoms, coloured scanning electron micrograph (SEM). Diatoms are single-celled photosynthetic algae, of which there are about 100,000 species, forming an important part of the plankton at the base of the marine and freshwater food chains. They have mineralised cell walls (frustules) that contain pure silica coated with a layer of organic material. The frustule is divided into two parts, one of which (the epitheca) overlaps the other (the hypotheca) like the lid of a box. Frustules are either elongated, or round and radially symmetrical.
Model release not available. Property release not required.