Flagellates

Flagellates, common name for a diverse group of unicellular organisms in the subphylum Mastigophora, kingdom Protista, that have in common whiplike projections called flagella, which they use for locomotion. They may live as single cells, in colonies, or as parasites. Almost any watery niche on earth contains large numbers of flagellates, and, along with diatoms, they are an important component of the marine food chain. Because flagellates show a mix of plant, animal, and fungal features, and because as colonies they exhibit coordinated activity, they provide clues as to how the multicellular forms of life may have evolved. Some dinoflagellates (phylum Pyrrophyta) are plantlike: They have cell walls, contain chlorophyll, and conduct photosynthesis. Some true dinoflagellates, however, resemble the animal-like flagellates (phylum Zoomastigina), which are soft-bodied, colorless, and feed on other organisms. See also Plankton; Protozoa.