Spondylus Regius - Sea Shell Shop, Rehoboth Beach, Delaware

'Thorny oysters' are not related to true oysters. The huge Hinnites of western American waters is in the scallop family and may weigh up to 20 lbs. The thorny oysters of the family Spondylidae have a typical ball-and-socket hinge joint and develop long spines. They occur in deep water, usually in the tropics, and have a thick, varied color pattern. These fairly common bivalves are sometimes called chrysanthemum shells.

Pondylus is a genus of bivalve molluscs, the only genus in the family Spondylidae. As well as being the systematic or scientific name, Spondylus is also the most often used common name for these animals, though they are also known as thorny oysters or spiny oysters.

Spondylus have multiple eyes around the edges of the shell, and they have a relatively well developed nervous system. Their nervous ganglia are concentrated in thevisceral region, with recognisable optic lobes, connected to the eyes.There are many species of Spondylus, and they vary considerably in appearance and range. They are grouped in the same super-family as the scallops, but like the true oysters (family Ostreidae) they cement themselves to rocks, rather than attaching themselves by a byssus. Their key characteristic is that the two parts of their shells are hinged together with a ball and socket type of hinge, rather than a toothed hinge as is more common in other bivalves.

Spondylus shells are much sought after by collectors, and there is a lively commercial market in them.

Size: 3-4"