Limnological studies on freshwater ponds of hyderabad-India

Summary The paper is based on a two-year study of the distribution of phytoplankton in three freshwater, polluted and unpolluted ponds of Hyderabad, India. The distribution of several groups of algae likeVolvocales, Chlorococcales, Desmids, Diatoms, Dinoflagellates, blue-greens andEuglenineae exhibited interesting relationships to the physioo-chemical complexes of the ponds, and throws much light on the algal distribution in Indian waters. The discussion revolves around the yearly and overall averages of the ecological factors and the various groups of algae. Dissolved oxygen, oxidizable organic matter, free carbon dioxide, nitrates, phosphates, calcium and sulfides have been found to play a significant role. The fluctuations of certain ratios such as N : P : K, C/N, percent sodium, percent Cl + NO₃ and Pearsall's basic ratio suggest distinctly important clues in the distribution of various groups of algae.Part of the thesis approved by Osmania University, Hyderabad, India, for the award of the degree of Ph. D.