The Spiny Oyster features an amazing thorny spiny shell that protects it from predators. It has an unusual ball-and-socket type hinge joining the two halves of its shell, and that makes it a beautiful addition to any reef tank. The Spiny Oyster cement itself to rocks rather than attaching itself by a byssus, and features two unequal valves unlike other shelled organisms. The Spiny Oyster can be grown up to 4 inches, with its spine up to 1 « inches. The color is variable that varies from white via yellow and orange to purple. The Spiny Oyster mainly prefers to live behind rocks and therefore, it is highly recommended to keep rocks in your fish tank. Add as many live rocks, and overhangs as possible since the Spiny Oyster prefers to inhabit under overhangs or in recesses. The Spiny Oyster also makes a beautiful ornamental shell, as its shell is fancy and its exquisite design draws attention to your aquarium. With its beautiful color of its spine, it adds a splash of vivid colors to the aquarium. It does not harm corals or other invertebrates, and are peace loving organisms. The nitrate levels have to be lower to help them survive in the tank. Due to presence of spines over its shell, it makes a good and peaceful inhabitant in the tank that can not be disturbed by other inhabitants. It is a reef safe species and a very good addition to any tank.