The Tuxedo Urchin, also known as the Sphere Urchin or Globe Urchin, is a popular species of sea urchin in the aquarium trade. As the name suggests, it has a distinct tuxedo-like appearance with a black body and white spines. These spines can also have a bluish or purple hue at the tips. Tuxedo Urchins are herbivores and use their spines to move around and graze on algae and other marine organisms. They can grow up to 4 inches in diameter and are generally peaceful towards other tank inhabitants. However, their spines can cause damage to corals and other delicate invertebrates, so it is important to provide them with ample hiding spaces in the aquarium.