Golden Orb on Ocean Floor Traced to Rare Anemone

Golden orb – A golden, orb-like “mystery” on the seafloor has been linked to Relicanthus daphneae after researchers reexamined older specimens, identified cnidarian-only cells, sequenced mitochondrial DNA, and tracked a distinctive golden cuticle it leaves behind.

For years, the golden orb sat on the ocean floor like a question mark—moving specialists from curiosity to frustration. It can reach 30 centimeters in diameter and lives between 1,600 and 4,000 meters deep. Even now. its biology hasn’t been a neat fit for the usual categories that define anemones and corals. leaving its evolutionary origin uncertain.

The breakthrough came with a species that finally ties to the orb: Relicanthus daphneae. Before the new study, there was nothing linking the golden orb to the giant anemone. The turning point was what researchers found during an initial examination. They spotted spirocytes—ultra-specialized cells found only in cnidarians, the animal group that includes anemones, corals, and jellyfish. That single detail pushed the mystery away from explanations like an egg or a biofilm, which had been considered earlier.

Still, identification wasn’t enough. The team sequenced the DNA of the material to search for matches in databases. The complete mitochondrial genomes showed a 99.9 percent match to Relicanthus daphneae. The evidence pointed toward the orb being part of a rare and poorly documented anemone.

But the ocean didn’t stop there with a new snag. The remains did not match any known structures of Relicanthus daphneae or any other anemone species. The answer required going back.

Researchers revisited a specimen collected years earlier and studied it again. They found fragments of a multi-laminated, golden cuticle that the anemone had produced around its base. Then they looked at live specimens. As Relicanthus daphneae moves along the seafloor, it leaves behind this cuticle on the rocks. It stays until it disintegrates or is buried. which helps explain how an orb-like form could appear in the first place.

The facts line up in a way that feels strangely simple once you see it: spirocytes confirmed the cnidarian origin. mitochondrial genomes connected it to Relicanthus daphneae with a 99.9 percent match. and the golden cuticle—multi-laminated and left behind as the animal travels—provided the missing physical piece. Even so. specialists still face the same larger frustration: the species’ biology doesn’t fully fit the rules used to define anemones and corals. and its evolutionary origin remains uncertain.

For the researchers, the “golden orb” is no longer a standalone enigma. It’s a trace of a deep-dwelling creature—an anemone that leaves something behind on the rocks as it moves, then lets the ocean slowly erase the evidence.

Relicanthus daphneae golden orb ocean floor discovery NOAA exploration spirocytes mitochondrial DNA cnidarians deep-sea anemone marine biology