Protococcophyceae

(also Chlorococcophyceae), a class of green algae embracing unicellular and colonial forms that lack flagella in the vegetative state. Reproduction is asexual, by means of biflagellate zoospores or autospores. In colonial forms, the spores in the parent cell develop into a daughter colony. The sexual process is most often isogamy.

The Protococcophyceae are widely distributed in freshwa-ters, in the soil, and on the soil surface. They are only rarely found in seas. Some live on the fronds of multicellular algae and the leaves of terrestial plants; others live on lichens in a symbiotic relationship with fungi. The USSR has 400 species, belonging to 150 genera. The algae are eaten by aquatic animals; they sometimes cause water bloom. Methods for cultivating the algae commercially as animal and human food and for other purposes are being developed. The most important representatives are Chlorella and Scenedesmus.