Ecological studies of Euglenineae in certain polluted and unpolluted environments

Summary The ecology of Euglenineae was investigated for two years in certain polluted and unpolluted environments of Hyderabad, India. The paper includes discussions regarding the distribution and periodicity of euglenoid population in relation to the physicochemical complexes which existed in the three ponds during the period of investigation. Sewage and Garden Ponds were found to be considerably polluted, whereas, the Typha Pond was comparatively pure and less polluted. Sewage Pond exhibited the highest percentage of Euglenineae harbouring 13 species and Garden Pond harboured 2 species in large numbers. Typha Pond harboured typically Trachelomonas hispida and Euglena Sp. which were totally absent in the other two ponds. It seems that high average concentrations of free CO₂ were favourable for euglenoid growth in Sewage Pond and the oxygen deficiency was helpful to trigger the oxygen-iron-phosphate complex, releasing larger quantities of phosphorus and iron. Higher average values of percent Cl + NO₃ ratio were found to be responsible for the luxuriant growth of these flagellates and it was suggested that inorganic sources of nitrogen might be more important in their ecology as fluctuations of nitrate coincide closely with those of Euglenineae in all ponds. These flagellates were found to be abundant during the periods when water was not rich in total sulphides and concentrations higher than 2.0 ppm adversely effected the euglenoid development. These flagellates were found to develop usually after rains or during intermittent showers experiencing comparatively higher temperatures. A temperature range of 27° – 39°C was observed to be favourable for their growth. Higher concentrations of oxidizable organic matter showed a direct relationship to euglenoid population in Sewage Pond. It is suggested that certain species of Euglenineae, which very often developed in the polluted waters of Sewage Pond, could be used as biological indicators of pollution in the present investigation.Part of the thesis approved by Osmania University, Hyderabad, India for the award of the degree of Ph. D.