The Common Octopus is, indeed, common. Its natural range extends from the Mediterranean Sea and the southern coast of England to the north west coast of Africa. They can also be found off the Azores, Canary Islands and Cape Verde Islands, preferring coastal waters. They can live in the shallows and also to a depth of 500 feet. They live up to 1-2 years in the wild.
Normally solitary, the octopus prefers to stay at home – their boneless body enables them to squeeze into the smallest gaps - and only leaves when it’s time to mate or eat. They hunt at dusk and will eat anything that strays into their path – although crabs, crayfish and bivalve molluscs are top of the list.
Recent research has found evidence that the Common Octopus stockpiles food. This is because divers have discovered piles of living bivalves around the burrows where the octopus lives. This is believed to be so that they can pop out at any time and enjoy a seafood snack. They also collect crustacean shells and other objects to construct 'gardens', around their lairs.
In early spring however, the adults leave their crags, crevices and burrows and move closer to the shore for spawning. Mating pairs may often look like they are holding hands. This is because the male pumps spermatophores down a specially modified tentacle called the hectocotylus to fertilise the female's eggs.
After mating (about 2 months) the female lays up to 500,000 eggs in shallow water. She attaches them to rocks, coral or sometimes even man made objects and cares for them by blowing oxygenated water over them and cleaning them with her suckers. Once they have hatched she dies and the hatchlings drift away on the currents. Only about 1 or 2 in 200,000 will survive.
Octopuses have proved themselves time and time again to be capable of learning and can distinguish the size, shape brightness and colour of objects. They can solve problems by trial and error – and remember what they had to do. They have been known to unscrew jars with ease.
Perhaps the most remarkable thing about the Common Octopus is its ability to blend in with its surroundings and express its mood through colour. Using a network of pigment cells and specialized muscles in its skin, the Common Octopus can almost instantaneously change colour and match the colours, patterns, and even textures of its surroundings. While their pigmentation is normally brown, octopuses turn white when afraid, or red when angry. They may also adopt deflective markings to scare away potential predators.
The octopus has no skeleton but does have a skull which protects the brain. They also have a sharp beak and a toothed tongue called a radula, which it uses to pry open and drill into the shells of prey, like crabs and clams.
Octopus are fast swimmers and can jet forward by expelling water through their mantles. However, if that isn’t enough to escape a predator they can lose an arm to escape a predator's grasp. This will regrow in time. Amazing!