Aquatic fungi contribute to the energy flow and productivity of aquatic and semi-aquatic ecosystems by their active role in the utilisation and biodeterioration of organic materials. These fungi also possess the ability to parasitise aquatic plants and animals, including fishes, under certain conditions. Physiology, environmental needs and activity of these fungi vary with their morphological characters. The taxonomy of these fungi can not remain static. The morphological variability of these species is ultimately linked to the genetic control of their characters. A considerable number of taxonomic studies have been carried out by a number of mycologists all over the world.
The present monograph shows occurrence, distribution, taxonomic characters and keys to the species of different genera belonging to orders Blastocladiales, Monoblepharidales, Saprolegniales, Leptomitales, and Legenidiales isolated from various ecological settings in India.