description

Cuttlefish share characteristics with their genetic cousins, octopuses, squid, and nautiluses. Each species looks different from the next depending on where they live and the composition of the food webs to which they have adapted. In general, you could describe them as fat squids with short arms and tentacles. They have a mantle (the main body cavity that contains their internal organs) like squid and a long, wavy fin used for movement that runs down the side of it. Cuttlefish vary in size but range from six to 20 inches in length.

Cuttlefish have two eyes, one on each side of their mantle, and W-shaped pupils. These animals – like their octopus cousins – are famous for their ability to change colors and in some cases textures to mimic their environments, despite being completely colorblind. Their camouflage abilities are made possible by chromatophores – pigmented skin cells and muscles that contract and expand to darken the skin. They have beaked mouths beneath the eight suckered tentacles that hang from their face, but no teeth. Their brain-to-body ratio is one of the largest of any invertebrate, larger than that of most species of octopus. They are well-adapted to quickly process and respond to environmental conditions, including sight, sound, and chemical changes in the water.

Similar to swim bladders in fish and oily livers in sharks, cuttlefish maintain buoyancy underwater using a specialized organ – their cuttlebone. No other animal has a cuttlebone, which is basically a hollow and porous internal shell made of aragonite, a form of calcium carbonate.