Ref ID : 2350
W. Petz, Wilhelm Foissner, and Hans Adam; Culture, Food selection and Growth rate in the Mycophagous ciliate Grossglockneria acuta Foissner, 1980: First evidence of Autochthonous soil ciliates. Soil Biol.Biochem. 17(6):871-875, 1985
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A culture method with defined medium for the soil ciliate Grossglockneria acuta Foissner, 1980 is described. Food selection studies reveal that it fed exclusively on three out of 11 fungi tested (Mucor mucedo, Mucoraceae and Aspergillus sp.) although all have a chitinous cell wall. The rejected species may synthesize antiprotozoal substances. No growth was obtained with yeast, bacteria, flagellates or the ciliate Colpoda aspera Kahl. Under laboratory conditions generation times ranged from 34.25 hr (4.5 degrees C) to 3.86 hr (30 degrees C). Correspondingly, population growth rate values ranged between 0.036 hr-1 up to 0.323 hr-1. A significant increase population growth rate was observed between 5.5 and 21 degrees C, whereas there was no reproduction at 40 degrees C. The most pronounced acceleration in population growth rate occurred between 10 and 21 degrees C. This is near the highest mean monthly temperature of the natural habitat (16.7 degrees C) of our population. Field observations yielded a higher density and frequency of G. acuta in alpine soils than in lowland ones. The experiments suggest that the low annual mean temperature could be responsible for this because highest individual densities develop at 4.5 degrees C. The highly specialized diet and the oral structure -a tentacle which is used in breaking up to sucking out hyphae and spores- are convincing proof that G. acuta is autochthonous to soil. This is emphasized by the fact that we could not find any member of the family Grossglockneridae during the investigation of more than 200 running and stagnant waters.