Physiology of metamorphosis

Life history transitions are critical for many species and often correspond to concomitant developmental and ecological shifts between two contrasting environments. Metamorphosis corresponds to one of these key transitions, allowing larvae to transform into juveniles to pursue growth in new environments. Numerous studies have investigated the regulatory mechanisms underpinning this major developmental transition using model species, such as amphibians, flatfishes, and zebrafish. However, even as traditional model species, they are far from representing the huge diversity that is characteristic of the teleost fishes and the various physiological changes occurring during metamorphosis. This article provides an overview of what is currently understood about metamorphosis in teleost fishes, starting with the knowledge accumulated from amphibians, detailing the information gathered so far on the regulation of metamorphosis, and reviewing what is known about the physiological changes occurring during this process. Understanding metamorphosis in fish spanning physiological, molecular, and ecological levels is crucial for effective ecosystem management and conservation, especially in the context of contemporary challenges like climate change, habitat loss, and human-induced environmental stressors.