Common octopus | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Order: | Octopoda |
Family: | Octopodidae |
Genus: | Octopus |
Subgenus: | Octopus |
Species: | O. vulgaris |
Binomial name | |
Octopus vulgaris Cuvier, 1797 |
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Synonyms | |
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The common octopus (Octopus vulgaris) is a mollusc belonging to the class Cephalopoda. Octopus vulgaris is the most studied of all octopus species.
Octopus vulgaris is considered cosmopolitan. Global in its range in 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.
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 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 in its saliva, and the octopus is able to grasp its prey using its powerful arms 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 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.
The common octopus is typically found in tropical waters throughout the world, such as the Mediterranean Sea and East Atlantic. They prefer the floor of relatively shallow, rocky, coastal waters, often no deeper than 200 meters. Although they prefer around 36 grams per liter, salinity throughout their global habitat is found to be between roughly 30 and 45 grams of salt per liter of water. They are exposed to a wide variety of temperatures in their environments, however their preferred temperature ranges from about 15 °C to 16 °C. In especially warm seasons, the octopus can often be found deeper than usual in order to escape the warmer layers of water. In moving vertically throughout the water, the octopus is subjected to various pressures and temperatures which affect the concentration of oxygen available in the water. This can be understood through Henry’s Law, which states that the concentration of a gas in a substance is proportional to pressure and solubility, which is influenced by temperature. These various discrepancies in oxygen availability introduce a requirement for regulation methods.