dsc_6983Spondylus versicolor Schreibers, 1793 by diver on rock and coral wall. Racha Islands, Thailand, 2014

Thorny oysters do not have much in common with the the true oyster. They hardly resemble each other. True oysters live in huge colonies whereas the thorny oyster tends to be a loaner. One is collected to be consumed as a delicacy. The other because of its attractive and delicate spines. They do have two things in common. Both attach themselves to a solid surface with a byssus. Both have a ball and socket that joins the two valves together rather than a toothed hinge as in other bivaves.
Spondylus in the only genus in the family Spondylidae. There are about fifty members in the genus and often are very confusing to classify. They are found in tropical waters around the world. Spondylus versicolor Schreibers, 1793 is called the “golden thorny oyster” though the color is more likely to be orange and never golden. This specimen is an albino but a look at the margin where the valves come together and one will see orange color.
Spondylus are highly collectible and eagerly sought out. Anyone who has collected live specimens can attest to how challenging many specimens are to clean.
This very attractive specimen came from the Phuket Islands area of Thailand and is about three and half inches across. Donated by Richard Kent and originally purchased from a Thai dealer.