Feeding and metabolism in fish are vital physiological processes regulated by interactions between internal endocrine signals and external environmental cues. Fish are highly sensitive to environmental parameters such as temperature, oxygen availability, salinity, photoperiod, pollution, and food quality. These variables influence feeding behavior, nutrient assimilation, and energy allocation. The regulation of these functions involves an endocrine network that integrates signals from the brain, gut, liver, and adipose tissue. Hormones such as neuropeptide Y (NPY), agouti-related peptide (AgRP), CART, orexin, leptin, ghrelin, insulin, thyroid hormones, melanocortins, and insulin-like growth factors (IGFs) play central roles in modulating appetite and metabolism.

As climate change alters aquatic environments, rising temperatures, hypoxia, acidification, and shifts in salinity and seasonal light cycles likely affect these endocrine systems. For example, high temperatures,
hypoxia and acidification might increase metabolic demand and affect feeding, induce changes in nutrient absorption and energy use, and thus modifying growth and reproductive functions. Many of these stressors interact synergistically. For example, warming and hypoxia together can reduce digestive performance more than either stressor alone. Climate-induced changes may also amplify the effects of pollutants or dietary imbalances, further challenging digestion, metabolic regulation and energy balance, with serious consequences for fish health, aquaculture productivity, and population dynamics.

Despite growing interest in environmental effects on fish physiology, there remains a critical gap in our understanding of how climate-related stressors affect the underlying endocrine and molecular mechanisms controlling feeding and metabolism. This knowledge is essential for anticipating speciesspecific vulnerabilities, and providing insights into aquaculture strategies and conservation efforts under
rapidly changing ecological conditions.

This Research Topic explores how environmental changes—particularly those driven by climate change—modulate the physiological and endocrine pathways that control feeding and metabolism in fish. This collection will provide valuable insights into fish adaptability in a changing world. Understanding these processes is vital for predicting ecological outcomes and ensuring the sustainability of fisheries and aquaculture under climate change. We aim to highlight integrative research that links environmental variables to neuroendocrine functions, metabolic adaptation, and energy balance.

We welcome original research, reviews, and methods papers addressing:

• Effects of warming, hypoxia, and acidification on appetite, digestive efficiency, and metabolic rate
• Neuroendocrine regulation of feeding and metabolism under climate stress
• Crosstalk between stress and metabolic endocrine axes (e.g., HPI–feeding axis interactions)
• Combined effects of multiple stressors (e.g., temperature × oxygen, diet × pollutants)
• Species and population differences in physiological resilience and metabolic flexibility
• Applications for aquaculture, fisheries management, and conservation in a changing climate

Are you interested in contributing a manuscript to this Research Topic?

How Does the Environment Modulate Feeding and Metabolism in Fish? Special Emphasis on the Impacts of Climate Change