Zebrafish have become one of the most widely used vertebrates in biomedical research, yet their welfare receives far less attention than mammals — despite their demonstrated capacity for pain and stress responses that warrant the same welfare consideration.
Zebrafish welfare is overlooked partly because of their small size and partly because their inclusion in welfare frameworks is relatively recent. Yet these are vertebrate animals with nociceptive systems, stress responses, and social needs that deserve genuine welfare consideration. Research conducted in stressed, poorly housed zebrafish may also produce less reliable results — creating the same alignment between welfare and science quality seen in mammalian research. The welfare investment needed for zebrafish is modest relative to the numbers used, making per-animal welfare improvements achievable at relatively low cost to research budgets.