Methods for Fish Biology

Chapter 12: Bioenergetics

S. Marshall Adams and James E. Breck


All energy acquired by an organism through ingestion must ultimately be used in metabolic processes, lost as wastes through excretion and egestion, or synthesized into new tissue (energy gain). Physiological energetics, or bioenergetics, is concerned with the rates of energy intake, transformations, losses, and uses as functions of the whole organism (Brett and Groves 1979). Bioenergetics provides a theoretical framework for relating growth rates and feeding rates of an organism to environmental conditions and provides some insight into causal relationships among these variables (Allen and Wootton 1982). The application of bioenergetics in fisheries involves partitioning ingested energy into the major physiological components of the basic energy budget equation of Winberg (1956):