From foundations to frontiers: Setting the stage for advances in fish physiological energetics

Shaun Killen and Tommy Norin discuss the J. R. Brett and T. D. D. Groves chapter “Physiological Energetics” in Fish Physiology, Volume 8, published in 1979. The next chapter in this volume is the re-published version of that chapter.

In the 45 years since its publication, Brett and Groves seminal review chapter on fish physiological energetics has been enormously influential across multiple disciplines, providing a comprehensive overview of fish energy budgets, including methodologies, nutrition, thermal adaptation, metabolic scaling, and environmental effects on growth. Here, we highlight the chapter's enduring relevance and impact on contemporary research, noting how advancements in knowledge, technology, and methodological approaches that have built upon Brett and Groves' foundational principles. Notably, there are also numerous concepts discussed by Brett and Groves that have been largely forgotten but that could form the basis for valuable conceptual frameworks or analytical approaches in contemporary studies of fish ecophysiology. Using Brett and Groves chapter as a historical reference point, we highlight ongoing challenges in accurately partitioning energy budgets and the complexity of metabolic processes, including costs associated with maintenance, activity, and digestion. We also discuss the intricate relationship between metabolism and behavior, an intense focus of recent research, in the context of Brett and Groves original perspectives on this topic. Brett and Groves' work presciently identified key research areas, many of which continue to be explored today. We discuss the historical significance of their chapter and emphasize its continuing influence and our evolving understanding of fish bioenergetics in the face of environmental changes.