The occurrence and distribution of aquatic fungi in certain ponds of Varanasi

Abstract

A survey of the Phycomycetous flora of the three types of the collecting stations in Varanasi was made for about ten months. The following observations were made: 1. An attempt was made to correlate the distribution of fungi in a group of small ponds, lakes with the idea of their occurrence, periodicity and environmental factors involved in the growth of aquatic fungi. 2. Sixteen species were recorded belonging to the Saprolegniales, Blastocladiales and Peronosporales. 3. There is distinct seasonal periodicity of growth which is mainly restricted to winter months. 4. The results indicate that the rarity of the many aquatic Phycomycetes may not be only due to specificity of substratum but also to temperature and the time needed for the maturation of the oospores. 5. The hydrogen-ion concentration of the ponds surveyed, has been measured, which supports the view of wide occurrence of members of Saprolegniales over a wide range of pH with the exception of Allomyces sp. and Pythium sp. which probably prefer the lower alkalinity of water. © 1966 Dr. W. Junk Publishers.