The cuttlebone of cuttlefish aids in maintaining buoyancy by using its chambered structure to keep a gas mixture at a relatively constant pressure.

“Cuttlefish (which look like bulgy squid) have a foamlike or corrugated cuttlebone containing a gas mixture at nearly constant pressure (fig. 5.1).” (Vogel 2003:97)

“The familiar internal shell or bone of the cuttlefish (Sepia officinalis L.) appears to function both as a skeletal structure and as a rigid buoyancy tank, enabling the cuttlefish to become more or less dense than seawater. Since an animal fractionally denser than seawater can only preserve constant depth by the expenditure of significant energy, the variable buoyancy tank role of cuttlebone confers a considerable advantage to the cuttlefish which can maintain a fixed position in water with little effort.” (Birchall and Thomas 1983:2081)

“The cuttlebone (which accounts for about 9% of the animal’s volume) is a hollow structure, divided by lamellae, containing both liquid and gas and the cuttlefish changes its density by varying the quantity of liquid within the porous structure of the bone.” (Birchall and Thomas 1983:2081)

Last Updated August 18, 2016