Some thorny oysters, and a giant clam at the Delaware Museum of Natural History.

Spondylus, or deep-water cousins of the scallops, found at depths of tropic waters up to 150 feet.

The thorns are to ward off predators, and they are usually covered in the muck of the sea

Thorny Oyster

Thorny Oysters

Tridacna Gigas ("Giant Clam"), the largest, and heaviest shelled mollusk, living 100 years or more, and weighing up to 500 pounds.