Untersuchungen zur Verträglichkeit von Meer- und Brackwasser für Ciliaten des Saprobiensystems der Wassergütebeurteilung

Abstract

More than 50% of the indicator organisms of the higher polluted zones are ciliates. Owing to this fact, ciliates are used extensively in laboratory experiments in order to produce more information regarding their ecological tolerances. The present paper reports new results obtained on ciliates exposed to sea and brackish water. The succession of freshwater ciliates associated with the decay of cellulose was investigated in 30-liter basins; detailed information is presented on successions observed in various concentrations of brackish water. When brackish water was used instead of freshwater, the number of ciliate species decreased rapidly, e. g., 40 species were found in freshwater, 26 in 3.5 ‰ S, 10 in 14 ‰ S and 4 in 35 ‰ S, respectively. Only a few indicator organisms used in fieshwater may, therefore, be of real value as indicators in high concentrations of brackish water. Most of the freshwater ciliates tested are not able to tolerate higher salinities at all. © 1968 Biologischen Anstalt Helgoland.