Recognition of fish pain by veterinary and regulatory bodies has grown substantially. Better pain assessment and analgesic protocols are transforming how fish are treated in aquaculture and research.
The recognition of fish pain has been one of the most significant developments in animal welfare science over the past two decades. Earlier assumptions that fish lacked the neural complexity for pain experience have been overtaken by evidence: fish have functional nociceptors, respond to noxious stimuli in ways modified by analgesics, show learned avoidance of painful situations, and display physiological stress responses with the same hormonal markers as mammals. Veterinary and regulatory frameworks are adapting: fish are now included in EU scientific procedure regulations, and analgesic protocols are becoming standard in research settings. Aquaculture welfare improvement lags behind but is advancing: less stressful harvest methods, water-to-water slaughter transitions, and improved stocking density standards all reduce fish pain and distress.