Cuttlefish bones
Cuttlefish bones or cuttle bones are the internal calcareous or calcium-rich shell of the cuttlefish. Cuttlefish bones are the white, chalky, surfboard-shaped shells that often wash up onto beaches. They are all that remains after a cuttlefish has been attacked and eaten.
The cuttlefish bone is made up of many layers of porous, calcareous shell interspersed with tiny, gas-filled cells. This allows the cuttlefish to vary the amount of fluid to air in the shell and have neutral buoyancy.
The cuttlefish bone also protects the internal organs and forms a framework against which the muscles can pull.
Some cuttlebones that are washed up onto beaches have teeth marks on them. These marks usually occur during the death struggle but are sometimes inflicted after death by hungry birds and fish while the shell is still floating in the ocean. Studying the bite marks may give some idea of the type of marine life found in that area.
Cuttlefish bones:
- are a valuable source of calcium to a bird, when placed in bird cages
- can be ground into a fine powder that can be used for polishing silver or even, cleaning teeth
- are used by craft workers for sharpening fine instruments
- are used by silversmiths for making moulds for casting.