The Dumbo Octopus Is a Deep Sea Ballerina

The octopus' semitranslucent, bell-shaped body could be mistaken for a friendly ghost drifting through the water. Most are small (8 to 12 inches or 20 to 31 cm long), although a 6-foot (1.8-meter) specimen has been seen.

Dumbo octopuses boast 60something suction cups along each of their arms. All the better to grasp and grab!

There are 17 species of dumbo octopus (that we know of), and in fact, all are known as Grimpoteuthis umbellata or "umbrella octopuses." (Flapjack octopuses are also a species of umbrella octopus.)

When dumbo octopuses extend their arms — which are connected with webbing — they can put on a show, puffing into a billowy form that looks like an umbrella.

It's the deepest-living octopus, believed to dwell in depths of 9,800 to 13,000 feet (3,000 to 4,000 meters) below the surface, in frigid, inky dark waters. In 2020, two dumbo octopuses were found at depths of more than 20,000 feet (6,100 meters), in the hadal zone, the deepest part of the ocean.

They were spotted by researchers on the Five Deeps Expedition, investigating the Indian Ocean's Java Trench. To capture images, the research team used a special deep-sea camera, designed by chief scientist Alan Jamieson, PhD.

Dumbo octopus species have been off the California and Oregon coasts, within the Gulf of Mexico, and near Australia, New Zealand, Papua New Guinea, and the Philippines. But given that they can survive (and even thrive) the deep ocean, which is largely unexplored, they might be living throughout the world.

Few creatures can survive in the hadal zone, where the weight of the water above creates pressure hundreds of times greater than at the surface — and in the zone's trenches, more than 1,000 times greater.

Most animals have a bit of air in their bodies, in their lungs or even their heads. Those air pockets would collapse under pressure in the deep ocean.

But dumbo octopuses are built for it.

"They don’t have any gas-filled spaces that are affected directly," says Stephanie L. Bush, PhD, at the Smithsonian, whose research on dumbo octopuses is co-funded by MBARI and the Monterey Bay Aquarium.

The dumbo octopus is well-suited to the deep sea in another way too. "Their enzymes have adapted over evolutionary time to allow them to live under pressure and cold temperatures," says Dr. Bush. "Our enzymes wouldn't work if we were under great pressure. Our chemical processes, like digesting food, would not work for us."

Like all octopuses, dumbo octopuses are able to survive in frigid, oxygen-poor environments partly due to their copper-rich blood.

Many octopuses have the ability to use jet propulsion to quickly escape predators. The octopus can suck sea water into their big, bulging mantle, then tense their muscles to spew it out, blasting themselves away to safety.

But the dumbo octopus seemingly has no such ability. With few predators in the deep sea, they don't have a need for speed. But what they lack in swiftness, they make up for in style.

The dumbo octopus glides through the ocean with the most elegant movements. It gracefully opens and closes its eight webbed arms to propel itself, using its ear-like fins to maneuver.

“[Octopuses] with fins mostly live in the water, constantly swimming and drifting,” says Danna Staaf, PhD, a marine biologist and author of "The Lives of Octopuses & Their Relatives: A Natural History of Cephalopods." "The ones without fins are the ones people are used to seeing in aquariums, and they mostly live on the seafloor, crawling around."

Most octopuses have an ink sac as a defense mechanism. The octopus can spew ink into the surrounding water to scare predators away — or befuddle the enemy while they make their getaway.

Dumbo octopuses do not have an ink sac. With few predators lurking in the deep sea, they are able to manage without such trickery.

And while many octopuses have the ability to change their appearance, that's not a strong trait of dumbo octopuses. "They live their entire lives in the dark, so they don't need to camouflage well," Dr. Bush explains.

Because red light doesn't filter down to the lower ocean zones, though, their reddish coloring works to their advantage, making them difficult to see.

The diet of the dumbo octopus may include fare such as oysters and crustaceans, snails and worms. (We say "may" because this species is difficult to study in its deep, dark natural habitat.)

In 2020, Harvard researchers discovered sensors within octopus suction cups that appear to help them discern whether the object they're touching might be a tasty treat.

Dumbos belong to a group of deep-sea octopuses called cirrates. That means they have spines on their suckers, known as the cirri. It is likely they use their cirri to sweep food into their mouth.

The deepest living octopus has certainly captured hearts. "I'm biased, but I think they are really cool," says Dr. Bush. "And there's so much unknown. This is true for any deep sea, open ocean organism."

The dumbo octopus is tricky to research because humans can't withstand the habitat's pressure and cold. "We have to bring them to the surface and put them in tanks," Dr. Bush says. "They don't do well at the surface [because] their enzymes are used to functioning at high pressure and low temperature."

And now, there are various companies and countries planning to mine minerals from the sea floor, which Dr. Bush cautions could harm marine life that we haven't yet learned about. New octopus species, for example, may yet be discovered.

Meanwhile, scientists hope to unlock more secrets of how octopuses work, including the charismatic dumbo octopus.