Signal and red swamp crayfish are widely used in research and traded as pets and food, with growing evidence of nociception and stress responses raising welfare questions.
Crayfish welfare represents an emerging area where the science is advancing faster than standards and practices. Evidence of avoidance learning, anxiety-like states modifiable by drugs, and physiological stress responses suggests that welfare consideration is warranted — though whether crayfish experience subjective suffering remains genuinely uncertain. The precautionary principle suggests that research and trade practices should minimize potential suffering: appropriate housing, avoiding unnecessary handling stress, and using the most humane available euthanasia methods. Consumer awareness that crayfish may have welfare-relevant experiences can drive improved practices in the pet and food trade.