page_title: Common octopus
section_title: Characteristics
hierarchical_section_title: Common octopus / Characteristics
caption_attribution_description: Octopus vulgaris
context_page_description: The common octopus is a mollusc belonging to the class Cephalopoda. Octopus vulgaris is the most studied of all octopus species. It is considered cosmopolitan, that is, a global species, which ranges from the eastern Atlantic, extends from the Mediterranean Sea and the southern coast of England, to at least Senegal in Africa. It also occurs off the Azores, Canary Islands, and Cape Verde Islands. The species is also common in the Western Atlantic. The common octopus hunts at dusk. Crabs, crayfish, and bivalve molluscs are preferred, although the octopus eats almost anything it can catch. It is able to change colour to blend in with its surroundings, and is able to jump upon any unwary prey that strays across its path. Using its beak, it is able to break into the shells of shelled molluscs. Training experiments have shown the common octopus can distinguish the brightness, size, shape, and horizontal or vertical orientation of objects.
  The octopus uses gills as its respiratory surface. The gill is composed of branchial ganglia and a series of folded lamellae.
context_section_description: Octopus vulgaris grows to 25 cm in mantle length with arms up to 1 m long. O. vulgaris is caught by bottom trawls on a huge scale off the northwestern coast of Africa. More than 20,000 tonnes are harvested annually.
  The common octopus hunts at dusk. Crabs, crayfish, and bivalve molluscs (such as cockles) are preferred, although the octopus eats almost anything it can catch. It is able to change colour to blend in with its surroundings, and is able to jump upon any unwary prey that strays across its path. Using its beak, it is able to break into the shells of shelled molluscs. It also possesses venom to subdue its prey.
  Training experiments have shown the common octopus can distinguish the brightness, size, shape, and horizontal or vertical orientation of objects.  They are intelligent enough to learn how to unscrew a jar and are known to raid lobster traps. O. vulgaris was the first invertebrate animal protected by the Animals (Scientific Procedures) Act 1986 in the UK; it was included because of its high intelligence.
caption: O. vulgaris from the Mediterranean Sea
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