Thermal Modulation of Endocrine Pathways Regulating Feeding, Metabolism, and Growth in Teleost Fish

Temperature is a major environmental driver of physiological function in teleost fish, influencing feeding, energy metabolism, growth, and stress responses through interconnected neuroendocrine pathways. This review synthesizes current knowledge on how relative warming and cooling, defined as temperatures warmer or colder than the control, acclimation, or seasonal reference conditions used in each study, modulate molecular and endocrine mechanisms regulating feeding and energy balance. We summarize temperature-dependent regulation of key orexigenic and anorexigenic pathways, including ghrelin, neuropeptide Y, orexin, agouti-related peptide, cocaine- and amphetamine-regulated transcript, proopiomelano­cortin, cholecystokinin, leptin, peptide YY, and corticotropin-releasing hormone, together with their interactions with the growth hormone–insulin-like growth factor axis and stress-related pathways. Comparative evidence across species indicates that thermal responses are highly context-dependent, varying according to species, exposure regime, and biological level. Across pathways, stable or variable regulation occurs more frequently than coordinated pathway-wide activation or suppression, indicating that temperature-driven responses are better characterized by flexible neuroendocrine adjustment than by conserved molecular signatures. We also discuss the potential contribution of the gut microbiota–brain–endocrine axis to thermal effects on metabolism and appetite, and examine the implications of temperature-driven physiological responses for aquaculture sustainability under climate change.