Mysterious 'Golden Orb' Identified as Part of the Base of a Giant Sea Anemone—But the Missing Creature Deepens the Mystery

A small golden structure recovered from the deep North Pacific has been identified after several years of analysis, resolving its biological origin while leaving key questions about its formation and ecological role unanswered.

The National Oceanic and Atmospheric Administration (NOAA), in collaboration with the Smithsonian Institution, has confirmed that the so-called 'golden orb' is biological material linked to a deep-sea sea anemone. However, the complete organism was not observed at the site of discovery.

Alaska Deep-Sea Discovery Puzzles Scientists

The golden orb was first observed in 2023 during a NOAA expedition aboard the Okeanos Explorer in the Gulf of Alaska. The object was found at a depth of around 3,300 metres and appeared as a smooth, dome-shaped golden structure roughly 10 centimetres wide, firmly attached to a rocky seabed.

At the time of discovery, scientists aboard the expedition were unable to identify it beyond confirming its biological origin. The unusual appearance led to immediate uncertainty, with early assessments considering possibilities such as a marine egg case, a sponge, or a coral-related structure.

A small opening or tear was also visible near its base, exposing internal tissue and complicating classification. Researchers noted that its intact, rounded form and unusual composition made it unlike commonly documented deep-sea specimens observed during remotely operated vehicle surveys.

Analysis Reveals Anemone Origin

After several years of laboratory analysis, including morphological examination and DNA sequencing, scientists from the NOAA, working in collaboration with the Smithsonian Institution, identified the 'golden orb' as biological material linked to the deep-sea sea anemone, Relicanthus daphneae.

Researchers determined that the sample contains cellular structures consistent with cnidarians, the group of marine animals that includes anemones and corals. These included specialised stinging cells known as cnidocytes, including spirocysts, which are characteristic of this animal group. Genetic analysis further supported the classification, matching the material to Relicanthus daphneae, a rare deep-sea species.

The findings indicate that the golden orb is not a separate organism, but rather a remnant of the anemone's basal attachment structure, which anchors the animal to the seafloor. Scientists interpret this structure as part of its anchoring system, adapted to extreme deep-ocean conditions where stable surfaces are limited and environmental pressures are high.

One Question Solved, Others Remain Open

While the analysis has resolved the structure's origin, it has raised further scientific questions. The complete organism associated with the formation was not observed during the expedition dive, and researchers only recovered the detached structure from the seafloor.

This has prompted renewed discussion about the species' behaviour and life cycle. One hypothesis is that the structure may be linked to growth or reproductive processes in deep-sea anemones, although this has not been confirmed.

Another possibility is that the basal structure was left behind after the organism moved or was displaced by environmental conditions on the deep-ocean floor. However, there is currently no direct evidence to confirm either scenario.

Rare Deep-Sea Species Remains Poorly Understood

Relicanthus daphneae is a deep-sea sea anemone first described in 2006 and is still rarely observed intact in situ on the seafloor. It inhabits extreme ocean depths, and most scientific knowledge of the species comes from isolated specimens or remote sampling rather than continuous observation.

Its morphology differs from many shallow-water anemones, contributing to its complex taxonomic history and making behavioural interpretation difficult.

The golden orb discovery highlights how deep-ocean ecosystems continue to reveal biological structures that remain poorly understood due to the challenges of direct observation.

Exploration Continues to Reveal Unknowns

The discovery underscores the role of modern deep-sea exploration technologies, including remotely operated vehicles and genetic sequencing, in identifying previously unclassifiable marine formations.

NOAA researchers continue to document unusual biological structures collected during ocean floor surveys, some of which require extended laboratory and genetic analysis before their origins can be confirmed.

While the golden orb has now been linked to a known species, its formation process and the absence of a directly observed complete organism remain unresolved, reinforcing the complexity of life in one of Earth's most inaccessible environments.