They are in general characterized by a ring of eight arms around the mouth. Most octopus are small, only 30 to 60 cm in length, but a few species reach the size of 10 meters Octopus generally move by walking with their suckers on the bottom of the sea floor. Like other cephalopods they can use a siphon to move at high speeds. In some species the arms ar joined at the base by a webbing of skin. In these species the octopus swims in the same manner that a jellyfish does, by sucking in water slowly and then expelling it quickly.
Octopuses are carnivorous, meaning they eat meat.
Prey is captured in the arms and brought to the mouth. There it is bitten by a parrot like beak and injected with poison. To escape from other predators an octopus may discharge ink as described earlier. Octopus have very complex eyes which are capable of image formation and shape discrimination. Octopus are eaten in several countries.