Description of Chlamydomonas

Cells mostly radially symmetrical, sometimes slightly curved, dorsiventrally flattened, sometimes surrounded by a gelatinous sheath, anterior papilla; 2 equal flagella; chloroplast single, variable in shape; nucleus more or less central; contractile vacuoles present; palmelloid stages, aplanospores and akinetes known; sexual reproduction usually isogamous, sometimes anisogamous or oogamous; zygote with smooth or sculptured thick cell wall, often accumulating secondary carotenoids; zygote germination involves meiosis and formation of four or eight meiospores; worldwide distribution; occur in freshwater and soil, more rarely in brackish and marine waters or snow, many species.