Physiological ecology of free-living protozoa

摘要: There are about 20,000 species of the single-celled animal-like organisms we call protozoa, and they most abundant phagotrophs in biosphere. One milliliter sea water contains 1000 heterotrophic flagellates (Sherr Sherr, 1984; Fenchel, 1988), freshwater sediments contain 10,000 ciliates (Finlay, 1980, 1982), organically rich habitats such as activated sludge plants support at least 105 per (Curds, 1973). The calcareous siliceous oozes that cover marine benthos largely composed sedimented shells skeletons planktonic foraminifera radiolaria, one wonder ancient world, great pyramid Cheops Gizeh, consists almost entirely compacted fossil foraminiferan Nummulites gizehensis (see Haynes, 1981).