ABSTRACT
Mathematical modeling of fish characteristics, such as growth or reproduction, aims at establishing relationships between two or more variables (e.g., body length as a function of age or fecundity as a function of body length) in a way that is as general as possible. In fisheries science, a very common approach used to infer the functional form that best describes the relationship between variables consists of fitting candidate functions to the data and performing goodness-of-fit analyses via statistical measures (e.g., Chen et al. 1992; Cailliet et al. 2006; Katsanevakis 2006; Quince et al. 2008). Often times, however, the best fitting function may turn out to be the one for which we have little theoretical justification, leaving us in the dark as to why a certain function fits the data very well. For this reason, mechanistic modeling from the first principles should be considered a preferable methodology whenever possible. Physiological energetics, by contrasting energy sources with sinks to determine the amount of energy available for growth and reproduction, represent a mechanistically-oriented approach in which mathematical models are built from the first principles of thermodynamics. As such, physiological energetics have long been used in fisheries science as a valuable means to 370probe the characteristics of fish metabolic rates and energy budgets. Recognizing this value, we overview the field of fish bioenergetics—a loose synonym for physiological energetics used here—as it pertains to tuna fishes and mathematical modeling thereof.
