Crowned Sea Urchin

Centrostephanus coronatus

Crowned sea urchins are easily identified by their all-black coloration, which may feature some blue at the base of their spines. Juveniles display distinctive gray bands on their spines. These urchins have a test diameter ranging from 32 to 63 millimeters, and their spines are notably thin, hollow, and brittle, with the longest reaching up to 125 millimeters. They are found in the eastern Pacific Ocean, from Monterey Bay in California down to Peru, including the Gulf of California and the Galapagos Islands. Typically, they inhabit rocky substrates and reefs, residing at depths ranging from the low-tide line to 125 meters, although most occurrences are shallower than 40 meters, with 90% found under 20 meters. As nocturnal foragers, crowned sea urchins venture out from their shelters at night, primarily feeding on sponges, tunicates, bryozoans, and algae. They seek refuge in holes and crevices on the seafloor, where their spines provide protection from predators. When they find a snug fit, they can brace themselves against the sides of the rock to avoid being dislodged. Reproduction occurs through external fertilization, with individuals being either male or female, and spawning typically follows a monthly cycle that may be influenced by tidal rhythms. Encounters with crowned sea urchins during dives can be intriguing, as divers may observe them nestled in rocky crevices or foraging at night. Their sharp spines serve as a reminder to maintain a respectful distance. The conservation status of this species has not been evaluated, but they are recorded at numerous dive sites, indicating a presence in various marine environments.