With eight arms protruding from their heads, octopuses are masters of camouflage and possess the remarkable ability to regrow limbs. These slinky Cephalopods seem more alien than earthly, leading to a captivating notion: they might have extraterrestrial origins. Despite having thrived on Earth for approximately 296 million years, a 2018 scientific paper introduced the otherworldly theory of panspermia, proposing that octopuses may have originated from planetary seeds in space. If you need more convincing, here are ten octopus facts to help you decide whether these age-old creatures are UFOs.
Octopuses Are Blue Bloods
While the jury is out on whether octopuses are ocean royalty, they do have blue blood. Their blood is blue because it contains hemocyanin, a copper-rich protein that carries oxygen around the body. Hemocyanin, which turns blue when it reacts with oxygen, is more effective at keeping octopuses alive in extreme conditions, like the cold ocean.
Octopuses Have Three Hearts
Arguably the most alien octopus fact: octopuses have three hearts. This is partially due to their blue blood as two of these hearts, known as the branchial hearts, pump blood to the octopus's gills where it gets oxygenated. The third heart, the systemic heart, pumps this newly oxygenated blood around the body.
Octopuses Have Arms and Legs
One of the most distinguishing features of an octopus is its eight tentacles, each with rows of suckers running right to the tip. But these appendages are not tentacles at all. Strictly speaking, they are arms and legs. True tentacles only have suckers on their tip. To make things even more confusing, an octopus's front six appendages are arms, used for feeding, grabbing and propulsion, while the back two are legs used for moving along the seafloor.
Octopuses Can Regrow Their Limbs
One of our favourite octopus facts is that they have regenerative properties and can regrow lost arms. While lizards do the same with their tails, this feat is much more impressive in octopuses. A lizard's regrown tail is often not as good as the original, but regrown octopuses' arms are as good as new, suckers and all.
Octopus’s Garden Is More Than Just a Song
Any Beatles fan has heard of the song Octopus's Garden, written by Ringo Star after he learned that octopuses have gardens. While octopuses live in gaps and crevices in the reef and rocks (known as dens), outside, they have a carefully arranged array of decorations. Sadly, the rocks, shells, and other debris making up the garden aren't the result of a houseproud octopus, but rather to conceal the den's entrance.
There Are Hundreds of Species of Octopus
It's estimated that there are over 300 species of octopus. Although this group does share a few key features, there's an incredible amount of diversity within the octopus family. From the minuscule star-sucker pygmy octopus, measuring a minute 1.5cm, to the gigantic giant pacific octopus, which spans a whopping nine metres, there are octopuses in all shapes and sizes.
Some octopuses look more alien than others. Take the Dumbo octopus, which lurks some 1,200 metres deep and features two ear-like fins which it flaps like wings to swim.
Octopuses Are Seriously Smart
There's no shortage of stories proving just how smart octopuses really are. Compared to the size of their body, octopuses have the largest brain of all invertebrates, having as many neurons as a dog.
These fascinating creatures have problem-solving abilities, can navigate mazes and complete tasks for food. They can even get themselves in and out of containers. There have been several stories of octopuses escaping their tanks in aquariums, and in 2016, an octopus named Inky even managed to escape from the New Zealand National Aquarium.
Octopuses Give Their All to The Next Generation
One of our saddest octopus facts is that both male and female octopuses die after reproduction. Males typically die a few months after mating, while females die not long after their eggs hatch. Up until their eggs hatch, female octopuses have a tiresome job, foregoing food to tend to their brood. Depending on the species, this incubation period lasts between two and ten months.
Some Octopuses Are Deadly
If you ever see luminescent blue rings on an octopus, you might want to give it a wide berth. Despite being an underwater photographer's favourite subject, these blue-ringed beauties pack a lethal punch. Blue-ringed octopuses contain a powerful neurotoxin called tetrodotoxin which, even in small doses, can paralyse and kill people.
Octopuses Are Masters of Disguise
The ocean is a treacherous place, and to survive octopuses have some handy tricks up their sleeves. The masters of disguise, these amazing creatures can change the colour of their skin to blend in with their surroundings. To take things a step further, the mimic octopus has been shown to fool predators into thinking it is something more deadly by also changing its shape and the way it moves.