Nearly 6,000 feet below the surface of the Pacific, a remotely operated vehicle was threading its way across an underwater mountain near Darwin Island when its camera caught something moving — something small, vivid, and entirely out of place.
“He’s tiny!” one researcher called out. “It’s blue!”
What the ROV had found, crawling across the dark seafloor of the Galápagos, was a creature no bigger than a golf ball — and one that science had never encountered before.
A surprising encounter on the deep-sea floor
The 2015 expedition aboard the E/V Nautilus was a collaborative effort involving the Charles Darwin Foundation and the Galápagos National Park Directorate. The mission deployed a remotely operated vehicle to investigate the seafloor near Darwin Island, at the northern edge of the Galápagos archipelago — specifically, an underwater mountain sitting roughly 5,800 feet down.
When the tiny blue octopus drifted into frame, the researchers’ reactions were immediate and unscripted. The audio from the expedition captured that moment of genuine surprise. The team filmed two additional individuals that appeared to belong to the same species, then carefully collected one specimen using the ROV — a single animal that would eventually travel thousands of miles and unlock a scientific description years in the making.
Why this octopus immediately stood out
Back at the Charles Darwin Research Station, researchers sorted through dozens of deep-sea specimens collected during the expedition. The small blue octopus kept pulling focus. Its vivid color and golf-ball size set it apart from anything in the known record, so staff reached out to Janet Voight, curator emerita of invertebrates at the Field Museum in Chicago and one of the world’s leading octopus researchers. Her response was unambiguous: “Right away, I knew it was something really special. I’d never seen anything like it.” Shipping the preserved specimen from the Galápagos to Chicago required considerable time and coordination before Voight could examine it in person.
Scanning a rare specimen without cutting it open
Describing a new octopus species typically requires dissection — scientists need to examine the mouth, beak, and teeth to confirm a species is genuinely new. The team had only one specimen. “When you describe a new species of octopus, you have to look at all the parts,” Voight explained. “And to see those things, you have to cut the specimen open. We only had the one specimen, so I didn’t want to take it apart.” The solution was micro CT scanning, carried out at the Field Museum’s X-ray computed tomography laboratory by co-author Stephanie Smith — a technique that produces detailed 3D models from thousands of X-ray images without any physical cutting.
Senior author Alexander Ziegler, a researcher at the University of Bonn in Germany, noted that soft-part imaging was unusually clear, achieved without the heavy-metal contrast agents typically required, which would have been problematic on such a rare specimen. Internal organs and structures came through in enough detail to support a full species description.
Meet Microeledone galapagensis
The new species was formally named Microeledone galapagensis and described in the journal Zootaxa. CT scans provided clear views of internal organs and mouth structures confirming the octopus was genuinely distinct from any previously documented species. Its placement within the family Megaleledonidae — a group of deep-sea octopuses — adds a data point to ongoing efforts to understand how octopus lineages have diversified across the world’s oceans.
For Voight, who has spent more than 40 years studying octopus evolution, this marks the first time she has formally led a new species description. “These are little octopuses that live in the deep sea, and hardly anybody on Earth has ever gotten to see them,” she said. “I just feel lucky that I got to work with them.”
What one small octopus says about a vast, unexplored ocean
Researchers were direct about what this discovery implies: the deep waters around the Galápagos remain largely unmapped and understudied. Co-author Salome Buglass, a marine scientist formerly with the Charles Darwin Foundation, said the effort was worth every step. “Getting the specimen to Janet was a long process, but one I would gladly repeat if it means getting to know the most precious parts of our ocean just a little bit better.”
Voight offered a striking frame for the scale of what remains unknown: if you gathered all the land on Earth and placed it together, it still wouldn’t cover the Pacific Ocean. Each new species identified in these ecosystems builds the case for protecting environments that most people will never see and that science has barely begun to describe. A golf-ball-sized octopus, blue and unnamed for a decade after its first filming, is a reminder of how much the deep sea is still holding back.