Common Cuttlefish

The common cuttlefish is one of the largest species of cuttlefish with a mantle length reaching up to 45 cm (18 in) and a mass of 4 kg (8.8 lb) on a presumed male, although this is for an exceptional specimen in temperate waters; specimens in subtropical waters rarely surpass a mantle length of 30 cm (12 in) and 2 kg (4.4 lb) in mass. The mantle houses the reproductive and digestive tracts of the cuttlefish and is also home to an internal shell called the cuttlebone, located on the dorsal side of the animal. The common cuttlefish has two highly developed eyes, eight arms which are located around the mouth and are used to hold and manipulate prey, two specialized feeding tentacles which are used to ambush prey, and a beak housing a radula used in breaking down and consuming their (often armored) prey.

During the day, most cuttlefish can be found buried below the substrate and fairly inactive. At night however, they are actively searching for prey and can ambush them from under the substrate. Cuttlefish are carnivorous and eat a variety of organisms including crustaceans (crabs and shrimp), small demersal fish, molluscs (clams and snails), and sometimes other cuttlefish which is more commonly seen when the abundance of other prey is low.

A 2008 study on S. officinalis revealed that cuttlefish embryos, if visually exposed to a certain species of prey (e.g. crabs), will hunt primarily for that prey in later life. S. officinalis usually prefer shrimp to crabs, but when the embryos were exposed to crabs and the embryos had hatched, the young cuttlefish switched preferences and proceeded to hunt the crabs more often than the shrimp.