Common Octopus
Encyclopedia
The Common Octopus is the most studied of all octopus
species. Its natural range 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
.
O. 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 mollusks (two-shelled molluscs such as cockles) are preferred, although the octopus will eat 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. The prey is paralyzed by a nerve poison, which the octopus secretes, and the octopus is able to grasp its prey using its powerful tentacles with their two rows of suckers. If the victim is a shelled mollusc, the octopus uses its beak to punch a hole in the shell before sucking out the fleshy contents.
Training experiments have shown that 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 is the only invertebrate animal protected by the Animals (Scientific Procedures) Act 1986
in the UK; it was included because of its high intelligence
.
Octopus
The octopus is a cephalopod mollusc of the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms...
species. Its natural range extends from the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
and the southern coast of England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
to at least Senegal
Senegal
Senegal , officially the Republic of Senegal , is a country in western Africa. It owes its name to the Sénégal River that borders it to the east and north...
in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. It also occurs off the Azores
Azores
The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...
, Canary Islands
Canary Islands
The Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...
, and Cape Verde Islands
Cape Verde
The Republic of Cape Verde is an island country, spanning an archipelago of 10 islands located in the central Atlantic Ocean, 570 kilometres off the coast of Western Africa...
.
Characteristics
Mantle (mollusc)
The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.In many, but by no means all, species of molluscs, the epidermis of the mantle secretes...
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 mollusks (two-shelled molluscs such as cockles) are preferred, although the octopus will eat 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. The prey is paralyzed by a nerve poison, which the octopus secretes, and the octopus is able to grasp its prey using its powerful tentacles with their two rows of suckers. If the victim is a shelled mollusc, the octopus uses its beak to punch a hole in the shell before sucking out the fleshy contents.
Training experiments have shown that 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 is the only invertebrate animal protected by the Animals (Scientific Procedures) Act 1986
Animals (Scientific Procedures) Act 1986
The Animals Act 1986 is an Act of the Parliament of the United Kingdom passed in 1986, which regulates the use of laboratory animals in the UK. The Act permits experiments to be carried out on animals, including procedures involving vivisection, if certain criteria are met...
in the UK; it was included because of its high intelligence
Cephalopod intelligence
Cephalopod intelligence has an important comparative aspect in the understanding of intelligence because it relies on a nervous system fundamentally different from that of vertebrates...
.