The effect of marine and Aral Sea water on the salinity tolerance of three Paramecium species (Ciliophora)

The shift of salinity tolerant ranges in three species of ciliates Paramecium caudatum, P. primaurelia and P. jenningsi was studied in waters containing a composition of salts resembling those in the Aral Sea, in comparison with composition of salts in marine waters. The results indicate that the salt values of tolerant ranges are increasing in water with the Aral Sea composition. The ratio among values of tolerant ranges is described by a linear function. A similar ratio connecting the same tolerant ranges exists in ciliates, but leads to reliable values of tolerant ranges when expressed in terms of chlorine concentration. Thus, the connection between the tolerances of aquatic organisms obtained for water of marine composition and water of continental composition might be described by the equation , where S_m = tolerance of organisms in marine water, whereas S_k = tolerance of organisms in continental saline water. The term α indicates the portion of chlorine ion continental saline water, while β indicates the portion in marine water.