Due to unique hydrological properties, the aquatic ecosystem has supported the development of a very complex biotic community on the earth. Human has long depended on aquatic resources for food, medicines and materials as well as for recreational and commercial purposes. After 20th centaury water pollution increases rapidly and it is our duty to examine water pollution and control it because water is mother of life and benthic community is one on the most important pollution indicator organisms. The text book of Benthic communities in some derelict waterbodies of Aligarh is the outcome of sincere and combined efforts of authors and editor. Authors earnestly hope that this book will enhance the curiosity of our target readers to know more and more about benthic communities and its role in water. It will arm them with latest information for facing any type of knowledge of benthic community in derelict water quite adequately.