Encyclopedia of Plant Physiology - New Series v. 7 . Gliding rates are also generally slower than the rates of locomotion displayed by swimming forms. A Comprehensive Guide to Biology and Laboratory Use . The Invertebrates . Cambridge University Press, 1979.
Ciliates swim faster than flagellates.
Alexander, R. McNeill. Cambridge University Press, 1979. The speed of a single-celled animal is affected mostly by the cell's physiology and its environment. Unicellular organisms may swim or crawl through their environments, depending on what appendages the organism has for locomotion. Due to a cell's small size and fluid-filled environment, the viscosity of the organism's surroundings produces the greatest effect on its movement, rather than inertial forces that larger organisms would encounter.