Weird Nature

21 Fun Facts You Should Know About Octopuses 

Corey Barger
Updated November 13, 2019 62.9k views 21 items

Octopuses are extremely complicated, mysterious, talented creatures with a long list of hidden talents! These spineless but colorful sea-dwelling beasts have been around for ages keeping life in the ocean interesting. Check out this list of the most fun octopus facts and quickly see why these creatures reign supreme on the ocean floor.

This list of random octopus facts will make you fear and admire the animals down below... if you ever see one. They are masters of defense with the ability to camouflage their entire bodies in mere seconds. In addition, they are extremely agile due to their lack of a skeleton, and they can even grow back arms they've lost! And let's not forget the way octopuses use ink to deter predators. That unique defense mechanism has fascinated humans for centuries! These interesting octopus facts are only the beginning on this list, full of fun information about octopuses.

Take a look at all the facts below and vote up the coolest and most interesting octopus tidbits. And watch out for those arms - they are more than just suction cups!
Octopuses May Change Colors When They Dream
Octopuses May Change Col... is listed (or ranked) 1 on the list 21 Fun Facts You Should Know About Octopuses
Photo: Nature/PBS

Scientists aren't certain whether octopuses dream when they sleep (and, even if they do, whether their dream state is anything like a human's), but Heidi the octopus made a strong case for her species when she was recorded sleeping in an episode of the PBS documentary series Nature.

In the film, the unconscious Heidi is seen twitching her tentacles, flexing her mantle, and shifting through a cascade of vibrant colors and patterns. Over the footage, marine biologist Dr. David Scheel is heard theorizing that Heidi may be dreaming about catching and eating a crab. "It's a very unusual behavior to see the color come and go on her mantle like that," he says. "You don't usually see that when an animal's sleeping."

Humans are still far away from understanding the cephalopod mind, so whether Heidi is truly dreaming or not remains speculation. Scheel has noted that the explanation for her colorful display may be much simpler: her color-changing cells could be activated by her nocturnal muscle twitches. 

Neuroethologist Daniel Margoliash has suggested that animals with complicated nervous systems may need to dream to regulate their experiences and memories. In the Heidi video, Margoliash says it appears that Heidi's eyes move as if she's in a R.E.M.-like state. "Who knows!" he says. "But you can’t ignore it... You have to study it."

Some Female Octopuses Have Deep-Sea Nurseries
Some Female Octopuses Ha... is listed (or ranked) 2 on the list 21 Fun Facts You Should Know About Octopuses
Photo:  juliepackard/Twitter

In October 2018, scientists discovered a nursery of octopuses off the coast of Monterey, CA. Researchers found thousands of Muusoctopus robustus two miles beneath the surface of the Pacific Ocean, nestling in the rocks. The females' bodies were inverted - or inside-out - which is common for females who are protecting their offspring. Some of the inverted females even had embryos still attached to their tentacles. 

"We went down the eastern flank of this small hill, and that's when - boom - we just started seeing pockets of dozens here, dozens there, dozens everywhere," said Chad King, a chief scientist on the Exploration Vessel Nautilus. 

Scientists also noted that the water in the area "shimmered, kind of like an oasis or heat wave off the pavement."

This discovery suggests that octopuses brood - or take care of their young - in areas that have warm water, which may help their offspring survive. 

Octopuses Have Three Hearts
Octopuses Have Three Hea... is listed (or ranked) 3 on the list 21 Fun Facts You Should Know About Octopuses
Photo:  jurvetson/Flickr/CC BY 2.0

Two of an octopus's hearts move blood though the body, beyond the gills, while the third keeps circulation flowing for its organs. That third heart, called the systemic heart, stops beating when an octopus swims. This is suspected to be part of the reason why octopuses prefer to crawl.

Source: Smithsonian
Octopuses Have Blue Blood
Octopuses Have Blue Bloo... is listed (or ranked) 4 on the list 21 Fun Facts You Should Know About Octopuses
Photo:  NOAA's National Ocean Service/Flickr/Public Domain

Octopuses have evolved a copper-based blood (rather than iron-based blood, like humans have) that allows them to survive in the deep ocean. This type of blood is blue due to a protein called hemocyanin, and it is efficient at transporting oxygen throughout the octopus's body in low temperatures.

Source: Smithsonian