The Cephalopod. atlasJerusalem :Israel Program for Scientific Translations ; Springfield, Va. : available from the U. S. National Technical Information Service,1975.biodiversitylibrary.org/page/62585142
Cuttlefish, like their cousin the octopus, have eight arms. Cuttlefish differ however in that they have in internal calcareous "shell" that is porous; they use this for buoyancy control in order to hover level. Their movement is largely controlled by fluttering fins along the side of their body. They also have two specialised tentacles; they can shoot them out to grasp their prey.