Responding to Russian Blue post, didn't quote video for space.
Those shells in the box with sands a little bit of water are called "Florida Fighting Conch" and are more common than french fries at McDonalds here on SWFL beaches and especially the area where TS lived. I know personally because I have collected 100's of them (after the animal is dead of course). Also, it's illegal to take live shells and you can be heavily fined, but I guess on the laundry list of all the crimes CWW committed that is a fairly small one, but still. It's a crime none the less. These shells are fairly common after storms and high winds, and in fact, the beach can be littered with 1,000's after a heavy storm. The general rule is is you see one, you throw it back in the water. Maybe TMI but thought I would share.