This book discusses the fundamentals as well as modern approaches of zoology. It delves into the embryology, evolution, habits and distribution of all animals of this planet. It classifies and analyses animals on the bases of physiology, ethology, biogeography, etc. Zoology has many branches such as comparative anatomy, animal physiology, behavioural ecology, etc. This book will provide comprehensive insights into the field of zoology. It will discuss in detail the new methodologies and evaluations related to this subject. Those in search of information to further their knowledge will be greatly assisted by this book. It is a collective contribution of a renowned group of international experts. It will serve as a valuable source of reference to graduate and post-graduate students as well as zoologists, researchers and professionals associated with zoology.