There are around 300 species of octopus, and they are found in every ocean, most living on the seafloor but some drifting nearer to the surface. In South Africa, the most common octopus is… the common octopus or Octopus vulgaris. The octopus is a master of camouflage and is renowned for its rapid colour changes. It can adapt its body colour to match that of the surrounding environment within seconds. Our common octopus is housed in the Skretting Diversity Gallery – be sure to check it out.
Fun facts about octopuses
- The octopus has the intelligence of a domestic cat and can be taught to distinguish between objects of different sizes, shapes, colours and textures.
- The eyes of an octopus are remarkably like those of humans: they also have a cornea, an iris, a lens, a pupil and a retina.
- Octopuses have three hearts: one circulates blood around the body, while the other two pump it past the gills to receive oxygen.
- Cephalopod, which means “head-foot” in Greek, describes the way that octopuses’ limbs are directly attached to their heads.
- Octopuses use ink as a defence mechanism: they have glands that squirt clouds of ink into the water to confuse potential predators.
- Octopuses have blue blood! Where humans have iron in their blood, octopuses have copper. This allows octopuses to thrive in cold and low-oxygen conditions – perfect for life in the ocean.
What is an octopus?Octopuses are part of the mollusc family – to which snails, mussels, squid and cuttlefish also belong – and are probably among the most sophisticated invertebrates. Unlike most molluscs, the octopus’ shell has been modified to an internal rather than an external shell. Octopuses have hundreds of suckers attached to each of their eight arms; each has its own set of nerves and can be controlled individually. Generally, octopuses’ length ranges from 30 cm to 90 cm, but some species can grow to 5.4 metres. The common octopus lives in crevices and holes and is fiercely territorial. Octopuses will fight to the death to retain ownership of a cave, which is why we only display one at any given time.
Habitats and lifestyleThe common octopus lives at depths of up to 200 metres and feeds on crabs, shellfish and rock lobsters. It is the most studied species of octopus, as it is distributed worldwide. Using long tentacles studded with suckers, they catch their prey with great speed and accuracy. A strong beak, similar to that of a parrot, is used to tear their prey. Octopuses are hyper-intelligent but have very short lifespans – the common octopus may only live to two or three years when its arms approach about a metre in length. They also only have one opportunity to mate before they die. The male octopus dies soon after mating, while the female finds a suitable den site to lay eggs, which can number in the hundreds of thousands for some species. The female guards and cares for the eggs by aerating them with its siphons. As soon as they hatch, the young are fully independent. The female dies after her brood hatches.
CamouflageThe common octopus is able to mimic colours and even textures of the environment around it. Using a system of colour-changing chromatophores and tiny muscles in its skin called papillae, the octopus can go from smooth white to bumpy black and every colour in between. This ensures its protection from predators. The mimic octopus has the most impressive camouflage skills: discovered off the coast of Indonesia, this octopus can camouflage itself to look like animals that predators avoid, such as the devil firefish.
Aquarium lifeWe only collect small, young octopuses for the Aquarium and release them after a few months back into their natural habitat. This is why you might notice their sizes and personalities changing between visits - there is never a dull moment getting to know an octopus. To ensure the health and well-being of our octopuses, we ensure each has a natural habitat that includes a cave, movable rocks, and algae. We also provide “food puzzles” and non-food items, which encourage natural behaviour such as foraging and exploration.