40 Fun Facts About Dumbo Octopus

The dumbo octopus is named after Disney's big-eared film star Dumbo, who is which kind of animal?

An elephant mocked for his oversized ears, Dumbo starred in a 1941 Disney film. The octopus's two big flapping fins reminded people of him.

Dumbo octopuses, rarely seen alive by humans, hold which record among all known octopus species?

Deepest-living of all known octopuses, they are usually found 3,000 to 4,000 metres down. A few have been recorded close to 7,000 metres.

Living in permanent darkness, dumbo octopuses have lost which organ found in most shallow-water octopuses?

An ink sac is no use where there is no light to block, so dumbo octopuses have none. The same is true of every finned deep-sea octopus.

Rather than tearing food apart like most octopuses, how does a dumbo octopus typically eat its prey?

Swallows it whole is the dumbo octopus's way: small seafloor animals go down in one piece. Its simplified mouth has no need to tear or grind first.

A dumbo octopus, like its shallow-water cousins, has three of which organ?

Hearts come in threes for every octopus: two pump blood through the gills. The third sends it around the rest of the body.

What colour is a dumbo octopus's oxygen-rich blood, thanks to a copper-based protein instead of iron?

Blue blood runs through every octopus, coloured by the copper-rich protein haemocyanin. It carries oxygen better than iron-based haemoglobin in chilly, low-oxygen water.

Pearl, a young classmate in Pixar's Finding Nemo, is which kind of octopus, a finned cousin of the dumbo?

Flapjack octopus is Pearl's species, a flattened pinkish relative from shallower water. Resting flat on the seabed, it looks rather like a pancake.

Female dumbo octopuses carry eggs at many stages of development, suggesting that their breeding happens when?

All year round, it seems, because dumbo octopuses have no breeding season at all. A female can lay whenever conditions on the deep seafloor suit her.

Dumbo octopuses flap their fins to swim, whereas most other octopuses rely mainly on which method?

Jet propulsion, squirting water through a funnel, is the standard octopus way to swim. Flapping fins costs a dumbo octopus less energy in the food-poor deep.

The ear-like fins that give a dumbo octopus its cartoon-inspired name sit where on its body?

Just above the eyes is where each fin sprouts, one on either side of the body. Flapping them is the animal's main way of swimming.

Dumbo octopuses belong to which class of molluscs, alongside cuttlefish and nautiluses?

Cephalopods means head-feet in Greek, a nod to limbs that sprout straight from the head. About 800 living kinds are known.

Dumbo octopus eggs have been found attached to which animals growing on the deep seabed?

Corals, specifically deep-water octocorals, give each egg a firm anchor on the seabed. Every egg sits alone in its own tough capsule.

Unlike most octopus mothers, what does a female dumbo octopus do with her eggs once they are laid?

Leaves them unguarded: the mother neither watches nor incubates her eggs. A typical shallow-water octopus stays with hers until they hatch, then dies.

The first dumbo octopus hatchling ever filmed, reported in 2018, emerged from its egg resembling what?

A miniature adult, fins and all: the newborn could already swim, sense its surroundings and catch prey. Most octopuses start life as tiny planktonic larvae instead.

Dumbo octopus arms carry a pair of small strands beside each sucker, known by which name?

Cirri are thought to help with feeding, perhaps by wafting food towards the mouth. They give the entire finned suborder its scientific name, Cirrina.

Dumbo octopuses seen below 6,000 metres live in which ocean zone, named after the Greek god of the underworld?

Hadal zone, after Hades, is the name for the ocean's trenches below about 6,000 metres. The term was only proposed in 1956.

Two dumbo octopus species were first collected in the 1870s by which British ocean research voyage?

The Challenger expedition dredged animals from the deep seabed while circling the globe. Its finned octopuses were at first filed under other scientific names.

Scientific names of dumbo octopuses end in -teuthis, which comes from the Greek word for which animal?

Squid is the meaning of the Greek teuthis, so these octopuses carry another animal's name. The study of octopuses and their kin is called teuthology for the same reason.

Unlike most octopuses, a dumbo octopus keeps which U-shaped support inside its body to anchor its fin muscles?

An inner shell, a leftover from the armour of its mollusc ancestors, braces the muscles that work the fins. Common shallow-water octopuses have no such support.

Finned octopuses such as the dumbo octopus have a reduced or missing version of which toothed feeding ribbon?

The radula, a ribbon of tiny teeth, lets most molluscs rasp their food into shreds. A few dumbo octopuses, including the emperor dumbo, still have one.

Oceana warns that which emerging seabed industry could wreck the fragile habitat of the dumbo octopus?

Deep-sea mining would stir up clouds of sediment and add noise, vibration and chemicals to a barely explored habitat. Scientists and several countries want it paused.

Dissections of dumbo octopuses show that they feed mainly on which small seafloor prey?

Worms and crustaceans such as copepods, isopods and amphipods turn up in dissected stomachs. Scientists rely on such finds because the animals are almost never seen feeding.

The emperor dumbo octopus was described in 2021 without dissecting its only specimen, thanks to which technology?

MRI and CT scans built a 3D picture of the animal inside and out, so the single known specimen never had to be cut open. A small tissue sample supplied its DNA.

The emperor dumbo octopus takes its regal name from which feature of the North Pacific seabed?

A chain of seamounts, the Emperor Seamounts, is where the only known specimen was found. The underwater mountains stretch across the northwestern Pacific.

A 2020 study reported a dumbo octopus filmed almost seven kilometres down in which deep ocean trench?

Java Trench footage showed the animal 6,957 metres down in the Indian Ocean. It proved that octopuses live even in the ocean's very lowest layer.

The tough outer casing of a dumbo octopus egg, absent in other octopuses, hardens on contact with what?

Cold seawater sets the casing hard soon after the egg is laid. Dumbo octopus eggs are also unusually large for an octopus.

Most dumbo octopus species are small and bell-shaped with short arms, growing to roughly what length?

About 25 cm is typical: most kinds measure 20 to 30 cm, roughly the length of a school ruler.

The common name dumbo octopus, often taken to mean a single animal, actually covers what?

More than a dozen species share the name, all in one genus of finned deep-sea octopuses. Several are known from only a handful of specimens.

Each fin of a dumbo octopus is stiffened at its base by a core of which flexible tissue?

Cartilage at the base of each fin gives the thick swimming muscles something firm to pull against, allowing quick bursts of speed.

Which scientific genus name, coined by zoologist Guy Robson in 1932, belongs to the dumbo octopuses?

Grimpoteuthis was Robson's new home for finned octopuses that had been filed under other names. Some classifications give the genus its own family, Grimpoteuthidae.

National Geographic notes that the dumbo octopus, small and pale with ear-like fins, is often called what?

The world's cutest octopus is a common label for it, earned by a round, bell-shaped body that hovers close to the seabed.

The suckers of Stauroteuthis syrtensis, a finned relative of the dumbo octopus, can unusually do what?

Glow in the dark is the talent that earned it the name glowing sucker octopus. It is one of very few octopuses able to make their own light.

A small Californian relative of the dumbo octopus, studied in 2015, was informally given which species name?

Adorabilis was floated because the little pinkish animal looked so cute, but the name was never formally published. It now appears to be a kind already known from Peru and Chile.

As molluscs, dumbo octopuses are distant relatives of which slow-moving garden animals?

Snails and slugs are gastropods, by far the biggest branch of the mollusc family tree. Clams and mussels are cousins too.

The dumbo octopus hatchling studied in 2018 carried which built-in food reserve against early starvation?

A large yolk sac inside the body keeps the newborn fed, so failing at its first hunt is not fatal. No hatchling of a finned octopus had been seen alive before.

Dumbo octopuses are found from about 1,000 metres down, in the sunless layer better known by which nickname?

Midnight zone is the popular name, because no sunlight reaches it and nothing there can photosynthesise.

Nanaimoteuthis, the oldest known finned relative of the dumbo octopus, lived in which geological period?

Cretaceous rocks in Japan and Canada hold its fossils, from the last age of the dinosaurs. One giant kind may have been more than six metres long.

Dumbo octopuses have lost several typical octopus features but still keep which hard mouthpart?

A beak, the parrot-like jaws at the centre of the arms, survives in every finned deep-sea octopus even though other feeding equipment has shrunk away.

Which deep-diving marine mammal is a known predator of finned octopuses related to the dumbo octopus?

Sperm whale stomachs have yielded finned octopuses, as have those of seals, sharks and large fish. How these slow, soft-bodied animals escape their hunters is largely unknown.

Besides swimming, dumbo octopuses in the Atlantic have been watched moving over the seabed in which slow way?

Crawling on arms spread wide, they inch along the bottom, and they often simply rest there. When disturbed they push off and switch to fast fin-swimming.