Cuttlebone

Cuttlebone, also called cuttlefish bone, is a hard and brittle internal shell found in all cuttlefish. Cuttlefish belong to a family of sea creatures called Sepiidae, which are part of a larger group known as cephalopods. This special bone is made mostly of a material called aragonite.

The cuttlebone helps cuttlefish stay balanced in the water. It has special chambers that the cuttlefish can fill with gas or liquid to move up or down easily. On the bottom side of the cuttlebone is a tiny organ called a siphuncle, which helps control these chambers.

Because the cuttlebone can break under deep water pressure, most cuttlefish live in shallower parts of the ocean near the seafloor. When a cuttlefish passes away, its body breaks down, but the cuttlebone often remains and can sometimes be found on beaches.

Human uses

In the past, cuttlebones were ground up to make polishing powder for goldsmiths. The powder was also added to toothpaste and used as an antacid or an absorbent. People also carved them as art during the 19th and 20th centuries.

Today, cuttlebones are used as a calcium-rich supplement for caged birds, chinchillas, hermit crabs, reptiles, shrimp, snails, and laying hens. These are for pets only and not for humans to eat. You can find them at pet stores.

Cuttlebone can also be used to make calcitic lime. Because it can handle high temperatures and is easy to carve, it is used to make molds for small metal castings, like jewelry and tiny sculptures. It can also be used in making pewter items.

Internal structure

The cuttlebone has a special internal structure made of two parts: horizontal layers and vertical pillars. Both are mostly made of a material called aragonite. The horizontal layers split the cuttlebone into separate spaces, and the vertical pillars support these spaces. These pillars have a wavy shape, and their thickness changes depending on the type of cuttlefish. The horizontal layers are usually thicker and have a special arrangement of tiny crystals and rods, creating a strong structure. Because of this design, the cuttlebone has lots of empty space, making it very light.

Mechanical properties

The cuttlebone has been studied a lot because it can be light, strong, and able to handle damage at the same time. These special qualities have inspired scientists to make new materials. Because it is so light, the cuttlebone is used in some advanced technology areas.

The cuttlebone stays strong even though it is made mostly of aragonite, which is a hard but breakable material. This is because of the special way the cuttlebone is built, with many small chambers and walls that help it absorb energy when it is pushed or squeezed.