Octopuses that live in the deep open ocean are difficult enough to find. But try locating a “glass” octopus, which is nearly transparent. Floating in the dim midwaters, this gelatinous octopod looks almost like a be-suckered jellyfish. Rather than camouflaging like most known octopus species, the Vitreledonella richardi has taken this alternative approach to hide [...]

That octopuses can survive in the extreme, sunless environments around deep hydrothermal vents is surprising enough. But comparing octopuses that make their homes there has led to some even more interesting discoveries about animal development. The rarely seen Muusoctopus hydrothermalis live some 2,495 to 2,620 meters below the surface, along the East Pacific Rise. There, [...]

Down in the dark depths of the deep ocean live more than a dozen species of “Dumbo” octopuses. These octopods from the genus Grimpoteuthis are so named for their prominent, unusual earlike fins that they use to help them swim (reminiscent of the Disney elephant character who used his ears to fly). These graceful, gelatinous [...]

Today we’re returning to the deep to meet an octopus that, at first glance, hardly seems to earn that eight-limbed designation. Its very name sounds like an oxymoron—or a cautionary tale from a fishing accident. But the seven-armed octopus (Haliphron atlanticus) is a real, bonafide octopod—if a little misleading in its appellation. This deep-ocean octopus [...]

Almost as fast as you can say “go-go-gadget arm,” an octopus can stretch its arm more than twice its normal length—without the help of any cyborg attachments. What’s more, according to new research, female common octopuses (Octopus vulgaris) are able to stretch their arms even more than the males—on average, three times resting length. This [...]

We continue our exploration of the many mysterious octopuses that live far from shore—and the eyes of humans. Today we meet the blanket octopus (Tremoctopus), a genus with four species that, until recently, had only been described based on female specimens. Why? Although they live in the vast open ocean, they are big (up to [...]

The many octopus species that live beyond the reach of vacationing snorkelers, scuba diving researchers and even near-shore commercial fisheries are relative unknowns compared with the more familiar shallow-water species. But that doesn’t mean that they are not of great importance to science—and the ocean’s intricate food web. Last time we met the super-fecund cephalopod [...]

Shallow-water octopuses can be difficult enough to find. They camouflage against corals, hide in holes and generally make themselves scarce. But researchers can at least attempt to observe and collect them by snorkeling, diving or skimming nets and bottom trawls. The rest of the vast, dark ocean, however, presents a much larger sampling challenge. So [...]

Of all the amazing octopus species out there, the mimic octopus, Thaumoctopus mimicus, is perhaps the most bewildering. While most known octopuses are able to change color and shape for camouflage, mimic octopuses can also impersonate other animals to deter would-be predators. They can contort their bodies and long, striped arms to look—and swim—like other [...]

The octopus is a solitary creature. Most known species of octopus avoid the company their own kind. And you might, too, if you knew your conspecific were capable of cannibalism. So in public aquariums, these animals are usually kept in separate tanks to keep them safe (and to avoid any unsightly encounters in front of [...]