The book on "Fundamentals of Limnology" deals with air-breathing fishes which have evolved on several occasions. Evolution of the first bony fishes during the late Silurian and Devonian period produced two new features, lobe fins and the lung fishes. Animals inhabiting the water/air interface show many morphological and physiological adaptations designed with different types of function in that unique environments. In the present age there are new challenges. These include climatic change and contamination of the environment by anthropogenic activities, Thermal Springs, Lakes and Reservoirs. The subject matter has been delineated in 11 chapters: Science Dealing with Biological and other Phenomena Particularly Inland Waters Haemopotetic Activity in the Gills of Certain Teleosts Limnobiotic Studies of the Thermal Springs of Rajgir (Bihar) Natural History of Kosi River Basin Reproductive cycle in Parreysia favidens (Benson): A Freshwater Bivalve of Kosi River Thermal Springs Lakes and Reservoirs Ponds Swamps and Marshes Diel Variations of Certain Physico-chemical Factors and Plankton Population of a Chaur (Wetland) of Kusheswarasthan (Bihar, India) Biological Productivity And Energetics The book will interest students and research workers in the field of Limnology."