Strongylocentrotus purpuratus, the purple sea urchin, lives along the eastern edge of the Pacific Ocean extending from Ensenada, Mexico, to British Columbia, Canada. [1] This sea urchin species is deep purple in color, and lives in lower inter-tidal and nearshore sub-tidal communities. Its eggs are orange when secreted in water. [2]

Strongylocentrotus purpuratus has a round body that consists of a radially symmetrical test, or shell, covered with large spines. The test itself ranges from 50mm in diameter to an occasional 100mm in diameter. This test is covered with spines that are generally bright purple for adults.