Limitations of Euglenidae as Polluted Water Indicators

Abstract

A census of all spp. of Euglenidae found in 884 weekly samples taken from a 120-mile stretch of the Scioto River of Ohio (including clean water, polluted, transitional and a 2d clean water area) showed high seasonal occurrence in late summer. Only one sp., E. viridis, increased rapidly in polluted water; the greatest occurrence of 47 other genera and spp. was in the transitional and clean water stretches. Examination of other rivers failed to show significant increases in sewage-bearing waters. Some spp. have been found as blooms in waters not containing sewage. The Euglenidae as a whole are not a satisfactory indicator of pollution.