Date of Award


Degree Name

Master of Arts


Biological Sciences

First Advisor

Dr. T. S. Robinson

Second Advisor

Dr. Richard Brewer

Third Advisor

Dr. Leo C. Vander Beek

Access Setting

Masters Thesis-Open Access



Tardigrades, comprising fewer than 350 species, are microscopic animals which inhabit mosses, lichens, and algae. Tardigrades or "water bears" are distributed throughout the world. These invertebrates are found in fresh-water substrates (Cooke, 1959; Marcus, 1939, Moore, 1939; Pennak, 1940), marine substrates (Chitwood, 1951; Green, 1950; Jeannel et al., 1940; Marcus, 1927, 1946; Pennak, 1953:240; Wieser, 1959) and terrestrial habitats (Cuenot, 1929; Marcus, 1960; Rodriguez-Roda, 1948; Pennak, 1953:240). The "water bears" have also been found in the psammolittoral zone where they live between grains of sand, (Pennak, 1940) and there feed on algal cells (Marcus, 1929). Tardigrades puncture the cell well of mosses and other cryptogams and suck out the cell contents (Higgins, 1959). Only one species, Milnesium tardigradum Doyere, is considered to be carnivorous (Pennak, 1953:243). The first tardigrades were described as the "little bears of water" by J. Goeze in 1773 (Marcus, 1960). The name "tardigrades" was applied in L. Doyere's fundamental memoirs on the class (Marcus, 1960).

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