Horizon 1 1 5 OS CH : Chapitres d'ouvrages scientifiques Ecology of marine fish 65-90 2025 Londres Elsevier fdi:010097194 ENG 10.1016/b978-0-323-99036-3.00009-x https://www.documentation.ird.fr/hor/fdi:010097194 Horizon (IRD) Size matters in many facets of fish ecology and fisheries production. Growth is a fundamental biological process that is closely tied to protein metabolism. Different ways of describing individual fish growth can be identified, requiring careful selection of time scales and measurement of growth currency in relation to other factors. Acquiring biometric data across age points within a population or individual is crucial for accurate growth measurements, requiring careful consideration of essential conditions. Measuring growth can be based on various methods (direct measurements, size-composition data, sclerochronology, biochemical growth proxies or epigenetic aging) and various growth models can be used to describe the relationship between fish length and age. The von Bertalanffy growth function (VBGF) is the most famous and widely-used analytical method. However while such growth models are mainly empirical and phenomenological, they are based on bioenergetics assumptions, considering growth as a product of the balance between anabolism and catabolism. Several authors have developed bioenergetics theoretical frameworks to better describe physiological processes involved in growth and how factors like diet composition, feeding rates, and metabolic efficiency influence the growth potential of marine fish. These frameworks can also help predict responses to environmental changes, such as shifts in prey availability and climate-induced habitat alterations. 034 ; 036