A cephalopods (meaning 'head-footed') with an elongated, flat wide body. They have well-developed heads, with large eyes and mouths that feature beak-like jaws and a fin runs around the body from behind the head . Encircling the mouth there are eight 'arms' with suckers, which are used to manipulate prey, there are also two tentacles with flattened paddle-like tips, which can be rapidly extended and are used to catch prey. Cuttlefish have an internal shell known as a cuttlebone, which is filled with gas and aids buoyancy. Colour is extremely variable, and depends on the environment, mood and life-cycle.
During spring and summer, males and females migrate to warmer water in order to spawn. Males often engage in spectacular displays to attract a female, in which bands of colour pass rapidly along the body; fighting over females is common. The eggs are attached to objects on the sea floor such as shells and seaweeds; after spawning, both the males and females die. Young cuttlefish reach maturity at 14-18 months of age, and the average life span is 1-2 years.