Sea urchin roe is an acquired taste. Served as sushi, uni — the Japanese word for this delicacy — is actually the reproductive organ of the sea urchin. One of the most highly valued coastal fisheries in California is the red sea urchin (Mesocentrotus franciscanus), found in the Pacific Ocean from Alaska to Baja California. Red sea urchins are sold to processors who determine the price of each uni batch based on its quality — a function of its size, shape, texture and color (usually orange to yellow).