Preface for the Fifth Edition of The Physiology of Fishes

Suzie Currie and David H. Evans

Fishes are the most speciose of vertebrates, and their diversity, behaviour, ecology, and performance capture our imaginations. Since there is still much to discover about these intriguing aquatic vertebrates, we are delighted to present the fifth edition of The Physiology of Fishes. It has been 27 years since the first edition of this book, and after three more editions and variations on the theme, we feel we have returned to the original ethos – a one-volume resource of the fundamentals and latest developments in this fascinating area of biology.

For both of us, mentoring our students is and has been the most rewarding and important aspect of our careers. With that in mind, the goal of the fifth edition is to provide an introduction to fish physiology for newcomers to the field. These learners may be undergraduate or graduate students or, indeed, more seasoned scholars interested in pivoting in a new and exciting research direction. We hope the readers share our enthusiasm for this fifth edition, where you will read about fresh perspectives on the basics of fish functioning as well as the latest advances and discoveries.

You will see that while each of our 17 chapters is focused on a specific area of fish physiology, our authors have taken an integrative approach, as is appropriate in this diverse field. The chapters also collectively highlight the importance of fishes as models to understand essential aspects of animal functioning, ecology, and evolution. We thought it important to begin the book with an introduction to fish phylogenetics and evolution (Evolution and Phylogeny), as these relationships are critical to our understanding of the how and the why. Some of our chapters take a systems approach (Gas Exchange, The Cardiovascular System, Iono- and Osmoregulation, The Digestive System, Endocrinology, Reproduction), and others cover sensation (Hearing, Active Electroreception and Electrocommunication, Vision, Olfaction), performance (Locomotion and Biomechanics, Metabolism, Behaviour and Learning), and the latest in integrative themes of Thermal Biology, Aquaculture and Fisheries, and Epigenetics.

We are finishing this edition while physically distancing and self-isolating in the middle of an astonishing global health crisis and pandemic. By the time you read this book, we hope that we will have an effective vaccine and that life will have returned to a new normal. This event gives us perspective and gratitude for our lives, families, friends, and colleagues, and we appreciate the opportunities to study fish biology. It has been an absolute delight to work together on this project with our diverse and brilliant authors and with our patient, responsive, and creative publishing team. Thank you for your shared enthusiasm for all things fish!