The third edition of Biology of Fishes is chiefly about fish as remarkably efficient machines for coping with the many problems that life in water entails, and looks at many such special cases. Fishes form the largest group of vertebrates, with around 20,000 known species, and they display a remarkable diversity of size, shape, internal structure and ecology to cope with environments ranging from transient puddles to the abyssal depths of the sea. Biology of Fishes does not try to cover all aspects of fish biology, but focuses on the ingenious ways in which fish have resolved the particular problems that come from living in water, especially body fluid regulation, locomotion, feeding mechanisms, and sensory systems. Enough detail is provided for the reader to be able to go on and use primary research papers. Each chapter has been thoroughly updated and a new chapter on the immune system has been added. This is an ideal textbook for students of fish biology and any of the branches of aquatic biology. Given its skilful combination of breadth and detail, the book also provides a manageable review of fish biology for experienced biologists.