Spondylus
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Spondylus is a genus of bivalve mollusks, the only genus in the family Spondylidae. As well as being the systematic name, Spondylus is the most often used common name for these animals, though they are also known as Thorny Oysters or Spiny Oysters.
There are many species of Spondylus, and they vary considerably in appearance and range. They are grouped in the same superfamily 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 have multiple eyes around the edges of the shell, and they have a relatively well developed nervous system. Their nervous ganglia are concentrated in the visceral region, with recognisable optic lobes, connected to the eyes.
Spondylus shell are much sought after by collectors, and there is a lively commercial market in them. Archaeological evidence shows that people in Neolithic Europe were trading the shells of Spondylus gaederopus to make bangles as long as 5000 years ago. The shells were harvested from the Mediterranean but were transported far into the centre of the continent.
Some typical species are:
- Wright's Thorny Oyster, Spondylus wrightianus
- Japanese Spiny Oyster, Spondylus japonica
- Pacific Thorny Oyster Spondylus princeps
- Atlantic Thorny Oyster Spondylus americanus
- Regal Thorny Oyster Spondylus regius
- Nude Thorny Oyster Spondylus anacanthus
- European Thorny Oyster Spondylus gaederopus
- Spondylus versicolor
- Spondylus tenellus
External link
- Information about Spondylus (http://nighthawk.tricity.wsu.edu/museum/ArcherdShellCollection/Bivalvia/Spondylidae.html) from the website of the Gladys Archerd Shell Collection at Washington State University Tri-Cities Natural History Museum