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. This collection of pattern and color makes the Royal Urchin a fantastic addition to most reef tanks - it really stands out. It is nocturnal and will hide among rocks or substrate during the day and come out at night to feed on algae. 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. If low algae levels are present, they can be supplemented with other herbivorous food preparations. Overall, the Royal Urchin is an exciting and unique invertebrate that is reef safe and easy to care for.