With their extraordinary camouflage techniques and ingenious defences, the common octopus (Octopus vulgaris) is one of the most intelligent of all the invertebrates. This species is a mollusc belonging to the class Cephalopoda, and is widespread in tropical and warm temperate oceanic waters. Their vast distribution is a testament to the octopus’ ability to continuously adapt.
The common octopus has a unique and unmistakable appearance. They have eight grasping arms, or tentacles, which are also used for crawling along the sea floor. Each tentacle can be up to 1 metre in length and is lined with two series of cup-like ‘suckers’. These give the octopus a superb grip, acting like studs on the bottom of football boots. The suckers also have receptors that enable the octopus to taste what is touching (as I said, this animal is incredibly unique). Their huge, bulbous head is actually a fleshy mantle enclosing a cavity that contains vital organs, including gills for breathing. Another magnificent feature of the common octopus is their eyesight. This mollusc has two prominent eyes with a horizontal, slit-shaped pupil which give them surprisingly excellent vision.
This octopus is a predator of crustaceans, among other prey, and has a secret weapon hiding in its underside – a beak. Its jaws are a parrot-like peak, which is strong enough to penetrate the carapace (shell) of a crab or lobster. This beak can deliver a nasty bite and hides a venomous saliva used for subduing prey. They may also release a cloud of black ink to disorientate their meal before attacking. This ink is released from a funnel just behind its head and is mainly used as a defence mechanism. When faced with an enemy, they will release this ink (which contains chemicals that dull their attacker’s sense of smell) and swiftly flee from the scene. This funnel has two other main uses: to expel water after gills have extracted oxygen and to rapidly discharge water as jet propulsion for a quick getaway. There is no denying that this animal is exceptionally creative in its methods of predation and defence.
But their brilliance does not end there. For one, they can squeeze through minuscule cracks and crevices – any hole that’s not smaller than their beak. Furthermore, the common octopus can change colour in an instant. Their skin contains special cells called chromatophores. These contain pigment which can change the octopus’ colour and even texture, allowing them to blend in with their surroundings or to signal its mood if angry or afraid. Their camouflage is one of the best in the animal kingdom; predators such as sharks, eels, and dolphins swim by without even noticing them. I’m starting to question if there’s anything this animal can’t do.
In spite of its remarkable adaptations, the common octopus is short-lived, with a lifespan of 1 to 2 years in the wild. It takes little more than a year to mature and spawn their own offspring, Both mother and father die soon after mating as their time is completely focused on caring for and brooding their eggs. Upon hatching, an infant octopus enters the big, blue world with half a million of its siblings – ready to repeat this cycle all over again. The common octopus is the first invertebrate of my blog, and deservedly so. Their exceptional array of unbelievable characteristics and adaptations make them a true wonder of wildlife.
Hennessy, K., Wiggins, V. (2014) Animal Encyclopedia: The Definitive Visual Guide. 2nd edn. London. Dorling Kindersley.