After more than two years of investigation, marine researchers have finally solved the puzzle of a mysterious golden sphere that captivated the public when it was discovered during a 2023 NOAA research mission.
The enigmatic object, found at a depth of 3,250 meters (more than 2 miles) in Alaska’s Gulf waters, has been identified as the remaining base portion of a massive deep-sea anemone called Relicanthus daphneae. This section would normally anchor the creature to rocky surfaces on the ocean floor.
When NOAA’s remotely operated vehicle Deep Discoverer first encountered the strange, dome-shaped golden mass with a hollow center attached to a rock formation, the research team was completely baffled. Initial speculation ranged from egg casings to deceased sponges, with scientists wondering if something had entered or emerged from the peculiar structure.
“I don’t know what to make of that,” one researcher said during the original discovery. “Yeah, I don’t know what to think about this,” another team member responded. “My first guess would have been sponge, but…”
The discovery generated significant public fascination and widespread theories about its origin. The expedition crew collected the specimen using specialized suction equipment and transported it to the Smithsonian National Museum of Natural History for comprehensive examination.
Dr. Allen Collins, a zoologist who heads NOAA Fisheries’ National Systematics Laboratory, explained the complexity of the identification process. “We work on hundreds of different samples and I suspected that our routine processes would clarify the mystery,” Collins noted. “But this turned into a special case that required focused efforts and expertise of several different individuals. This was a complex mystery that required morphological, genetic, deep-sea and bioinformatics expertise to solve.”
The research team employed multiple scientific approaches to crack the case. Initial physical examination revealed the object lacked typical animal structures but consisted of fibrous material with layered surfaces containing cnidocytes – specialized stinging cells. National Systematics Lab researcher Abigail Reft identified these as spirocysts, which are found exclusively in the Hexacorallia group of cnidarians, including corals and anemones.
Early DNA testing proved inconclusive, likely contaminated by genetic material from other microscopic organisms on the specimen. However, advanced whole-genome sequencing revealed animal DNA with substantial genetic content matching the giant deep-sea anemone. Further mitochondrial genome analysis of both this specimen and a similar sample collected in 2021 confirmed they were genetically nearly identical to known Relicanthus daphneae reference genomes.
The fate of the anemone’s upper portion remains unknown – it may have died or relocated to establish a new home elsewhere on the seafloor.
CAPT William Mowitt, acting director of NOAA Ocean Exploration, emphasized the significance of such discoveries. “So often in deep ocean exploration, we find these captivating mysteries, like the ‘golden orb’. With advanced techniques like DNA sequencing, we are able to solve more and more of them,” Mowitt stated. “This is why we keep exploring—to unlock the secrets of the deep and better understand how the ocean and its resources can drive economic growth, strengthen our national security, and sustain our planet.”
The specimen has been permanently added to the Invertebrate Zoology Collection at the Smithsonian Institution’s National Museum of Natural History, where it will be available for future research.
NOAA Ocean Exploration plans to resume live deep-sea expeditions in May with a mission exploring Hawaiian waters. Additionally, Dr. Collins will discuss this discovery and other findings from the 2023 Alaska expeditions during a public webinar scheduled for April 30, 2026, at 4 p.m. ET.
