Fish Biology is an important field of Zoology. Fishery Science is a multidisciplinary subject depending heavily on all streams of science and all other knowledge. The book A Textbook of Fish Biology and Fisheries is another version of the famous book An Introduction to Fishes by Dr. S.S. Khanna, first published in 1970. The same book included some chapters on fish diseases and fish culture technology and its revised editions were published from 1978 onwards. When the old book was not avialable, the need for the present book first published in 2002, was felt. The present book covers almost all aspects of fish biology including conservation biology. All the topics of fishery science including fish culture and capture technology and advances in fishery science are covered. As such, the book will be useful for B.Sc. (Hons.) B.F.Sc., M.F.Sc. and M.Sc. Zoology (with specialisation in fish and fisheries). As the book contains multiple choice questions according to the new pattern of UGC, it will be found useful by those who prepare for various competitive examinations.