The conch shell is the outer skeleton ( exoskeleton ) of the mussels.

The conch shell is made of two equal flaps that surround the soft parts of the mussels. The two halves are held together by two internal sphincter and dorsal side, hinged to a lock band, the so-called ligament. The point of attachment of the sphincter is often seen on the inside of the shells. The castle tape is very elastic and keeps the shell halves on voltage. It cooperates antagonistic to the sphincters; that is, the voltage of the lock band opens the shell. After the death of the animal the sphincter limp (or detach from the shell ); the shell opens.


The gaping shells are readily separated by mechanical stress, such as the surf. One finds, therefore, much more often single shell halves as a " doublet ", which still consists of two flaps.

Thus, the two halves of the clam shell not slip to the side, wearing many types of so-called lock teeth, the wedge the both halves when closed together. The Castle teeth consist of interlocking, dental or strip-shaped elevations on the inner back edge of the flaps and corresponding pits on the opposite valve. Most shells are heterodont, that is her castle consists of a few main teeth and up to four strip-like lateral teeth. Because of the variety of different designs of the lock teeth they can often be used for zoological and systematic classification of shellfish.

Also interlocking notches on the lower edge of the shell can prevent lateral slipping. These notches are also defining characteristics of a bivalve mollusc. The curved shape gives clamshells their overall stability.


Shells are mainly composed of calcium carbonate ( lime), which occurs as the mineral aragonite. The aragonite crystals are cemented together by an organic substance, the Conchyn. The shells are from the coat, a skin fold of the shell is formed. The point of attachment of the jacket is on the inside of many shells to recognize (sheath edge ). The shells are made of three layers: the colored periostracum, the prismatic layer and the often rainbow colored iridescent nacre ( hypostracum ).


Shells are widely use, such as a jewelry material (mother of pearl ) or the bird or reptile feeding (including in tortoises ) as a calcium source. Fossil shells form a part of the partially used as a building material natural stone limestone.

Coat of arms of Mainz -Kastel

Coat of arms of Bad Mingolsheim

Shells of the scallop are shown in heraldry as a heraldic animal, as in the coat of arms of Ennigerloh, Mainz -Kastel or bath Mingolsheim (see list of arms with the scallop ).

The Group uses a shell upside stylized scallop as a company logo.

  • Anatomy (eddy lots)
  • Malacology