Ref ID : 2242
H.R. Hoogenraad and A.A. De Groot; [Die geographische verbreitung der Susswasser-Rhizopoden]. Hydrobiological Bulletin 13(2/3):152-171, 1979
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Notes
1. The thesis of the cosmopolitical distribution of the freshwater rhizopods was in general accepted in the last century. The investigations of the last seventy years have proved, however, that there are to distinct two geographical zones of distribution: a northern zone, nearly identical with the geological LAURASIA (North America, Europe, Asia) and a southern zone (South America, Africa, Australia, New Zealand and Antarctica), identical to the geological GODWANA. Each zone is marked by some characteristic rhizopods adapted to the environmental conditions of wet mosses. 2. The rhizopod fauna of the contact zones (Central America and Indonesia) is showing a mixed character with often many southern species and varieties. 3. The distinction above mentioned of two zones is not manifest for rhizopods, which are not sensitive to environmental factors. Only statistical comparison of whole protist populations from similar environments may give some result. 4. The more or less cosmopolitical genera of the southern associations show a greater variability by displaying more species varieties. 5. A tropical barrier zone does not exist. 6. Many finding-places in tropical areas are exposed to often extremely varying atmospheric changes of the environmental factors. The many "new" species and varieties found there should be used considering the problems of distribution.