A camera feed from a scientist-controlled submersible near the Galapagos Islands suddenly delivered an unexpected star: a mysterious octopus, ocean-blue and roughly the size of a golf ball, resting on the seafloor.
“He’s tiny! It’s blue!” one scientist exclaimed on the recorded footage as the cerulean cephalopod came into view.
Researchers from the Charles Darwin Foundation say the encounter led to the identification of a previously unknown octopus species found nearly 1,800 metres below the surface, according to new research.
“Right away, I knew it was something really special,” said octopus specialist Janet Voight, who was asked to determine what the team had found.
Initially, the curator at Chicago’s Field Museum of Natural History had only photographs to work from.
Later, the preserved specimen arrived by mail.
“When it arrived, I was like ‘Oh! My goodness! It’s beautiful’,” Voight said.
The team at the Field Museum used CT scans to take thousands of X-ray images of the specimen they were sent (Credit: Charles Darwin Foundation)
The tiny animal caught her attention quickly, in part because the closest known octopus with a similar shape lives off Uruguay — in a different ocean on the far side of South America.
Describing a new octopus species typically requires dissecting a specimen to study key anatomy such as the mouth, beak, teeth and other structures.
“We only had the one specimen, so I didn’t want to take it apart,” Voight said.
To avoid damaging the only example, the Field Museum team turned to CT scanning, producing thousands of X-ray images and assembling them into a 3D model that revealed the octopus’s internal features.
“There’s nothing like spending the day looking at something no other human has ever seen,” said Stephanie Smith, head of the museum’s X-ray lab, in a statement.
‘Deep purple’
The newly described species — Microeledone galapagensis — draws interest for more than its striking blue colour, which is believed to be the rarest in nature.
It also appears to be a small outlier within the Megaleledonidae family, a group whose members are usually much larger and associated with the Southern Ocean around Antarctica.
“Its stubby little arms with only one row of suckers set it apart from most octopus we are familiar with,” Voight said.
And even among “other species with short little arms and a single sucker row, its colouration and smooth skin on the back surface separate it”, she added.
Voight said the animal is pale blue across its back, but underneath it turns a “very deep purple”.
“We think this colour pattern helps keep it safe. If the octopus grabs a prey item that emits light, that light may attract predators that might then eat the octopus,” she explained.
The new species is named Microeledone galapagensis (Credit: Charles Darwin Foundation)
“So the octopus puts its dark-coloured web over the prey item, keeping itself safe.”
Finding previously unknown octopus species in the deep sea is not as rare as it might sound, researchers say — especially in regions that remain scarcely explored, a category that covers much of the ocean floor.
“If you took all the land on Earth and pieced it together, you would not cover the Pacific Ocean,” Voight noted.
She said the last new octopus she encountered was in 2023, off Costa Rica.
The first sighting of the newly described blue octopus occurred in 2015 near Darwin Island, named for the English scientist whose Galapagos visit helped shape his theory of evolution.
Voight’s research on the species has been published in the journal Zootaxa.
