The series "Fish Physiology" recently celebrated its 50th Anniversary. In total, the editors of the series have produced a total of 47 books (several volumes have two books) that contain almost 500 chapters since the inaugural volume published in 1969. The content of the "Fish Physiology" volumes has evolved over time. The initial volumes were devoted to understanding the basic mechanisms and principles of fish physiology, with a focus on a few model species and some application to natural environmental conditions. Then, as the field better understood mechanisms, the approach was broadened to not only delve deeper into system physiology (e.g., chapters in early volumes were expanded to become books), but interspecific differences in physiology were explored, permitting a more evolutionary framework. Finally, as interspecific physiological mechanisms were further resolved, it became possible to discuss physiology in light of a changing world. Thus, physiology can now inform on conservation, sustainability and management, as exemplified with the most recent volumes. This anniversary issue celebrates the series by highlighting some of the very important early work in the field that was published in the Series. In particular, we wished to (re)introduce new researchers to this research that has stood the test of time and that shaped the field. Each re-published chapter is preceded by a short review written by experts in the field to provide an overview/introduction of each selected chapter, discuss what is particularly noteworthy or important in the particular chapter, and discuss why in their opinion this chapter has become a classic in its own right and how it has inspired the field of fish physiology today?

Conservation Physiology for the Anthropocene: A Systems Approach, Volume 39A in the Fish Physiology series, is a comprehensive synthesis on the physiology of fish in the Anthropocene. This volume closes the knowledge gap by considering the many ways in which different physiological systems (e.g., sensory physiology, endocrine, cardio-respiratory, bioenergetics, water and ionic balance and homeostasis, locomotion/biomechanics, gene function) and physiological diversity are relevant to management and conservation. As the world is changing, with a dire need to identify solutions to the many environmental problems facing wild fish populations, this book comprehensively covers conservation physiology and its future techniques. Conservation physiology reveals the many ways in which environmental change and human activities can negatively influence wild fish populations. These tactics inform new management and conservation activities and help create the necessary conditions for fish to thrive.

Conservation Physiology for the Anthropocene - A Systems Approach, Volume 39B in the Fish Physiology series, is a comprehensive synthesis related to the physiology of fish in the Anthropocene. This volume helps solve knowledge gaps by considering the many ways in which different physiological systems (e.g., sensory physiology, endocrine, cardio-respiratory, bioenergetics, water and ionic balance and homeostasis, locomotion/biomechanics, gene function) and physiological diversity are relevant to the management and conservation of fish and fisheries. Chapters in this release include Using physiology for recovering imperiled species - the Delta smelt, Conservation hatcheries - the Sturgeon story, Aquatic pollutants and stressors, and more. Other sections discuss Fisheries interactions in a multi-stressor world, Environmental change in riverine systems - Amazon basin stressors, Environmental change in lakes and wetlands - East African basin stressors, Coral reef fish in a multi-stressor world, Polar fish in a multi-stressor world, Physiology informs fisheries restoration and habitat management, A physiological perspective on fish passage and entrainment, Invasive species control and management - the sea lamprey story, and On the conservation physiology of fishes for tomorrow.