What type of mollusk is this?

[yardboy]

Found this on a piece of aquacultured Gulf liverock. Spiny oyster?
It's about 1" wide.

 

[JackKerouac]

I think it's some species of Spondylus genus

 

[yardboy]

Thanks.
I hope I can keep it alive to determine if that is the genus. It'll be easier to tell if it grows out it's spines.