Diatoms

Diatoms

Diatoms (Bacillariophyta) are tiny single-celled algae which have both green and brown photosynthetic pigments. Each diatom has a silica-impregnated shell, formed of two halves that fit together like a box and lid. When the cell divides, the two halves come apart and each daughter cell makes a new lid. There are about 16,000 species of diatoms living in fresh and salt water and they form a large part of the ocean's plankton, which is the basis of the food web for almost all marine creatures. Diatom shells come in all sorts of fantastically ornamented shapes and over the millenia dead shells formed sediments on the sea floor. This diatomaceous earth is a mild abrasive that is used in all sorts of industrial processes. Oils, once stored in cells of ancient diatoms, form a large part of today's petroleum reserves. [CH] {EB}