Blue-lined Long-spine Urchin

Range: Western Pacific Ocean (Red Sea to Okinawa), introduced to Hawaiian Islands

Although very similar to the Hawaii-native long-spined urchin (D. paucispinum), the blue-lined long-spine urchin (also called the Savigny's long-spine urchin) can be differentiated in a couple ways. First, unlike long-spined urchins, many (but not all) blue-lined long-spine urchins have bright, almost glowing blue lines along their tests in a five-fold, radially symmetric pattern. Second, the spines of blue-lined long-spine urchins grow to about eight inches - relatively short compared to their native counterparts, whose spines can grow up to 12 inches long.