The Spiny Oyster, Spondylus americanus, also known as the Spondylus, is a large sessile invert with a colorful orange mantle. It remains securely attached to the tank floor and does not move around. With their unique exterior, the Spiny Oyster makes a captivating addition to any tank. They are reef safe and usually kept solely for their interesting appearance. 

The Spiny Oyster is best kept in tanks with good water quality, moderate to strong current, and moderate light. They are peaceful and will readily take calcium supplements for better growth. 

The Spiny Oyster might be the organism for the history-lover. Its shell, the Spondylus shell, has been traded as an ornamental good dating back to the 5th millenium B.C.E in Europe. More recently, Spondylus shell was incredibly important for the success of the  Inca Empire as a trade good, ornate decoration, and an offering in sea-worshipping rituals.