A defining characteristic of the cuttlefish, the cuttlebone is a porous internal shell that helps control buoyancy, making it functionally similar to swim bladders in fish. Cuttlebones have both ...

All of them had a chambered shell that they used for buoyancy.' The group Cephalopoda is divided into three subgroups: coleoids (including squids, octopuses and cuttlefishes), nautiloids (the ...