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a division of microscopic algae usually consisting of a single free-swimming cell. Colonial forms are rare. The nucleus is clearly pronounced, and the green, rarely colorless, chloroplast may lack pyrenoids. The plastmatic cover, or periplast, of some species bears hard, iron-incrusted capsules. At the anterior end of the cell there is a gullet, through which one, two, or sometimes more flagella extend. The contracting vacuoles and stigma are located on the sides of the gullet. In creeping forms the flagellum is rudimentary. Reproduction is by means of longitudinal splitting. Under unfavorable conditions, some species discard their flagella and form protective spores (cysts). Nutrition is primarily phototrophic in green individuals and saprophytic and holozoic (according to the animal type) in colorless individuals. Parasitic species are few in number. The carbohydrate paramylum and oil serve as a food reserve.
There are about 60 genera, embracing more than 900 species, usually found in shallow reservoirs rich in organic matter. The USSR has 33 genera, with 429 species. The algae give water a green, red, or brown coloration when they grow abundantly. Many zoologists classify the Euglenophyta among the Protozoa.
REFERENCEPopova, T. G., and T. A. Safonova. Evglenovye vodorosli, Leningrad, 1976.
L. A. RUNDINA