Common octopus  (Octopus vulgaris)

Common and widespread (2).

The cephalopods (meaning ‘head-footed) are a group of molluscs that contain the octopuses, squid and cuttlefish, and are probably the most intelligent of all invertebrates. They have well-developed heads, with large complex eyes and mouths that feature beak-like jaws. All octopuses have eight tentacle-like arms; indeed ‘octopus’ derives from the Greek for ‘eight-footed’ (3). The common octopus usually measures around 60 centimetres in length, but it can grow up to 1 metre (2). It is able to change its colour depending on its mood and situation, but individuals are usually greyish-yellow or brownish-green with extensive mottling. They are often very well camouflaged (2). The body is warty, and the thick arms bear two rows of suckers (4).

This octopus is found from the southern North Sea down to South Africa. It also occurs in the Mediterranean (2). It reaches the north-eastern extreme of its range in Britain where it is found only around the coasts of the south and south west (4).

You can view distribution information for this species at the National Biodiversity Network Gateway.

Occurs along rocky coasts in the shallow sublittoral zone (4).

Like all cephalopods, the common octopus is an intelligent active predator (4). They have modified salivary glands that produce venom used to incapacitate prey. It is often easy to identify what a common octopus has been feeding on, as they leave piles of debris known as ‘middens’ around the entrance of the protective lair in which they live. These middens consist of debris from a range of species and often include mollusc shells and the carapaces of crabs and other crustaceans (5).

All cephalopods are good swimmers, and are able to move rapidly by jet propulsion when threatened; water is rapidly expelled through a funnel which causes the octopus to be propelled away rapidly (3). Cephalopods are also able to mask themselves as they escape with a cloud of ink released into the water (2).

Not currently threatened.

Conservation action has not been targeted at this common species.

There may be further information about this species available via the National Biodiversity Network Gateway.

View information on this species at the UNEP World Conservation Monitoring Centre.

For more on this species see:

• The Marine Life Information Network species account, available at:
  www.marlin.ac.uk/species/Octopusvulgaris.htm