Uncover the evolutionary marvels of Ichthyology, focusing on the fascinating adaptations of air-breathing fishes. This essential text guides students and researchers through the origins of bony fishes, vital respiratory organ morphology, and the unique physiology of aquatic life transitioning between water and air. With specific insights into Indian species and their respiratory systems, it addresses critical environmental factors affecting fish today. Ideal for Indian universities and scholars in Zoology, Aquatic Biology, and Ichthyology seeking a deep dive into piscine evolution and adaptation.