Freshwater crayfish are farmed, collected from the wild, and kept as pets worldwide. Their welfare as decapod crustaceans places them in scientifically contested sentience territory similar to marine crustaceans.
Freshwater crayfish welfare sits in scientifically contested territory: the London School of Economics review that informed UK law found sufficient evidence of sentience to warrant precautionary protection. The evidence includes nociceptive responses, avoidance learning, and stress responses to aversive stimuli. Traditional boiling of live crayfish is now illegal in the UK under the expanded welfare protection. Invasive crayfish management creates a welfare and ecology tension: the invasive signal crayfish causes harm to native ecosystems, making welfare-compromising control methods potentially justified under ecological urgency criteria. The companion crayfish keeping community increasingly engages with their pets as sentient individuals rather than living decorations.