The Royal Urchin (Mespilia globulus), is also known as the Globe Urchin, Sphere Urchin, Blue Tuxedo Urchin, and Tuxedo Pincushion Urchin. It has brilliant bands stemming from its center across a dark blue background giving it a look as though it is dressed in a tuxedo, hence some of the common names.
The Royal Urchins, are very peaceful creatures and will not bother other inverts, coral or fish. During the day, it will hide among the rocks, in crevices, or under plants in a sandy substrate. At night, it will emerge to graze on the algae present in or near its home.
Royal Urchins can reach a fully grown adult size of around 3 inches and need to be kept in a tank that is at least 29 gallons. They are able to kept successfully in pairs as long as there is enough room in the tank to move, places to hide, and algae to eat.
Overall, the Royal Urchin is an exciting and unique invertebrate that is reef safe and easy to care for.