In July 2015, the remotely operated vehicle aboard the exploration vessel E/V Nautilus was gliding along the seafloor near Darwin Island, at the northern edge of the Galápagos archipelago, when its camera caught something unexpected: a blue shape moving 1,773 meters below the surface.
On the deck, one of the researchers watching the live feed could barely contain their excitement: “It’s blue!”
Eleven years later, that little cephalopod finally has a scientific name. On May 25, 2026, the journal Zootaxa published the study formally describing it as Microeledone galapagensis, a species previously unknown to science.
A single specimen, studied without dissection
The team had only one specimen, which posed an immediate problem: determining whether an animal belongs to a new species typically requires a dissection that destroys the specimen.
Janet Voight, curator emerita of invertebrates at the Field Museum in Chicago and lead author of the study, took a different approach.
Working alongside Stephanie Smith, manager of the museum’s X-ray CT laboratory, Voight used micro-computed tomography scanning to build a detailed three-dimensional model of the animal’s anatomy without cutting it open.
When Voight first received photographs of the specimen at the Charles Darwin Research Station on Santa Cruz Island, she sensed she was looking at something out of the ordinary. “Right away, I knew it was something really special,” she said. “I’d never seen anything like it.”
The octopus is about the size of a golf ball. Its skin is smooth, nearly unpigmented on the dorsal side, and its striking blue color sets it apart from other species in its genus. It lacks an ink sac, a crop diverticulum, and anal flaps — features that initially suggested a different genus — but its smooth skin, sizable rachidian tooth, and large funnel organ place it firmly within Microeledone.
A family redefined by an animal too small and too tropical to fit the mold
The discovery has implications that reach well beyond a mere taxonomic description.
The family Megaleledonidae had long been defined as a group of large-bodied octopuses living exclusively in the cold, remote waters of the Southern Ocean.
Microeledone galapagensis fits neither of those criteria. Its existence prompted researchers to revisit and expand the formal definition of the entire family.
Salome Buglass, a marine scientist at the University of California, Los Angeles, and a former researcher at the Charles Darwin Foundation, said the small blue octopus stood out immediately among the many animals observed during the expedition.
What remains unseen in the deep tropical Pacific
The researchers stress that incirrate octopuses of the deep eastern tropical Pacific remain virtually unstudied, and that submersibles offer rare and valuable opportunities to observe them.
Janet Voight has spent more than four decades studying octopus evolution. This is the first time she has been the lead author on the formal description of a new species.
As she put it: “If you took all the land on Earth and pieced it together, you would not cover the Pacific Ocean. The oceans are so big, and there’s so much left to explore.”
During the same expedition, the Nautilus ROV filmed two more octopuses resembling the first, though neither was collected for analysis.
The single preserved specimen, retrieved from the seafloor on July 1, 2015, was enough to redraw the boundaries of an entire family.
The deep tropical Pacific, one of the least-explored regions on the planet, holds far more than the scientific record reflects.
Microeledone galapagensis is, for now, one of the few species known to live there.
