Sea urchins are farmed for their roe and used extensively in developmental biology research, with welfare considerations complicated by their echinoderm nervous system and uncertain sentience status.
Sea urchin welfare status is subject to the same uncertainty as other echinoderms. Their basic nervous system can detect noxious stimuli and produce avoidance responses, but whether this involves conscious pain experience is unknown. Research uses including embryo collection (spawning induced by injection) and developmental experiments may cause physiological stress. In aquaculture, crowding in holding tanks may prevent natural grazing behavior that is important to normal sea urchin physiology. The precautionary principle suggests minimizing unnecessary harm even in the absence of confirmed sentience, particularly given the uncertainty. As with other invertebrate research animals, continued scientific investigation of their neural function is warranted.