Any of about 100 species of marine cephalopods in the order Sepioidea, characterized by a thick, internal calcium-containing shell called the cuttlebone.
Species range between 1 and 35 in. (2.5–90 cm) in length and have a somewhat flattened body bordered by a pair of narrow fins. All have eight arms and two longer tentacles used to capture prey. Suction disks are located on the arms and at the tips of the tentacles. Cuttlefish inhabit tropical or temperate coastal waters. They feed mainly on crustaceans , small fishes, and each other. They are used by humans as food, as a source of ink, and for the cuttlebone, a dietary supplement for cage birds.
Cuttlefish ( Sepia officinalis )
Douglas P. Wilson