Strongylocentrotus purpuratus, commonly known as the American purple sea urchin, is a marine echinoderm in the family Strongylocentrotidae. It is native to the eastern Pacific Ocean, ranging from Alaska to Baja California, and is especially abundant along the rocky coasts of California and the Pacific Northwest. It inhabits intertidal and shallow subtidal rocky reef environments, where it grazes primarily on kelp and other macroalgae. The genus name Strongylocentrotus derives from Greek strongylos meaning “round” and kentron meaning “spine,” referring to its spherical, spiny body. The species epithet purpuratus comes from Latin purpura, meaning “purple”. Ecologically, it plays a major role in kelp forest dynamics, and population booms can contribute to the formation of “urchin barrens.”

Historically, Strongylocentrotus purpuratus has been harvested for food by Indigenous coastal peoples of western North America. As a food source, Strongylocentrotus purpuratus is valued for its gonads, known in Japanese cuisine as uni. The edible lobes have a soft, custard-like texture and a briny, sweet, and umami-rich flavor. On the west coast of North America, purple sea urchin is harvested and processed for domestic consumption and export, especially to Japan. It is most commonly eaten raw as sushi or sashimi, but it may also be incorporated into pasta, sauces, rice bowls, or lightly cooked seafood dishes. Quality is highly dependent on season, reproductive cycle, and diet, particularly kelp availability. In contemporary coastal cuisine it may be blended into butter, cream sauces, or seafood preparations.

Strongylocentrotus purpuratus contains omega-3 fatty acids such as eicosapentaenoic acid (EPA), Vitamin A/carotenoids such as echinenone and β-carotene, vitamin E (tocopherols), and free amino acids such as glycine, alanine, and glutamic acid, which contribute to sweetness and umami flavor. As a benthic grazer, Strongylocentrotus purpuratus can reflect local environmental conditions, and when harvested from clean waters it is regarded as both a nutritionally valuable and culturally significant marine food resource.