Cuttlefish have a short life span and a high growth rate. They are active swimmers with a predatory lifestyle, feeding largely on crabs, prawns, and fish.
Cuttlefish possess eight forward-reaching arms specialized to grasp the prey after it has been captured using an additional pair of elongated tentacles (Chaddha, 2007) with a single suction cup at each tip. In the middle of the eight arms, there is a small beak, which cuttlefish use to break open the shells of mollusks, crabs, and other crustaceans (Animal Guide, www.pbs.org). According to Chaddha, The arms are also important for a defensive display in which the cuttlefish sucks water into its mantle cavity and spreads its arms in order to appear larger to its potential opponent. (2007).
Like all cephalopods, cuttlefish possess a highly developed central nervous system with a well-defined brain. Their brain-to-body size ratios are the highest among all invertebrates. The cuttlefish brain can handle input from a variety of senses, including sight, smell, and even ‘sound’ (in the form of pressure waves). (Chaddha, 2007).
3. Cuttlebone. The internalization of the shell that occurred with evolution in the cuttlefish has helped them to become efficient swimmers. The internal shell of a cuttlefish, called the cuttlebone, retains air spaces and controls buoyancy making it functionally equivalent to swim bladders in fish (Chaddha, 2007). It also prevents them from colonizing the deep oceans since the pressure would cause a gas-filled shell to implode.