A golden, orb-shaped object discovered on the seafloor of the Gulf of Alaska in 2023 has been identified through genetic and morphological analysis as a biological remnant of the deep-sea anemone species Relicanthus daphneae.
The finding was announced by researchers from the National Oceanic and Atmospheric Administration (NOAA) and the Smithsonian National Museum of Natural History after a multi-year investigation.
Discovery
On August 30, 2023, during the Seascape Alaska expedition, the remotely operated vehicle (ROV) Deep Discoverer—deployed from the NOAA exploration vessel Okeanos Explorer—observed a small golden dome attached to a rock.
The object was located at a depth of approximately 3,250 meters (roughly two miles) southwest of Walker Seamount in the Gulf of Alaska.
The orb measured approximately 10 centimeters (four inches) across. It was described as smooth, mound-shaped, and golden in color with a small hole on one side. Attached to a rock among white sea sponges, the specimen was collected using a suction sampler and transported to the Smithsonian's National Museum of Natural History for analysis.
Identification Process
Initial examination revealed that the object was not a living animal but a fibrous material. Scientists observed that it was composed of multiple layers and contained specialized stinging cells called spirocysts—found exclusively in cnidarians, a group that includes sea anemones and corals.
Further analysis involving whole-genome sequencing and comparisons with existing genetic databases matched the specimen to the deep-sea anemone species Relicanthus daphneae.
Researchers concluded that the golden orb is a cuticle or remnant of dead cells from the base of the anemone, specifically the pedal disc that anchored the organism to the ocean floor. The material is composed primarily of chitin.
A similar specimen collected in 2021 during an expedition aboard the Schmidt Ocean Institute's Research Vessel Falkor also contained the same stinging structures, providing additional comparative data.
Background on Relicanthus daphneae
Relicanthus daphneae is a rarely collected deep-sea anemone species thought to be globally distributed at depths ranging from approximately 1,200 to 4,000 meters.
- Individual polyps can reach about 30 centimeters (12 inches) across.
- Their tentacles may extend up to two meters (over six feet) in length.
The spirocysts of this species are described as the largest among known cnidarians. The animals are believed to perch on rocks or sponges, extending their tentacles into currents to capture prey. They may also move across the seafloor, potentially leaving trails of similar golden cuticle remnants.
Scientific Analysis
The identification required collaboration across multiple scientific disciplines. Dr. Allen Collins, a zoologist and director of NOAA Fisheries, stated that the investigation required morphological, genetic, deep-sea, and bioinformatics expertise to solve. Capt. William Mowitt, acting director of NOAA Ocean Exploration, noted that techniques such as DNA sequencing are helping researchers solve deep-sea mysteries.
Implications
The specimen represents a novel microhabitat, consisting of a remnant cuticle and a microbial community living on and beneath it. Researchers have proposed that the shedding of this material may be related to a form of asexual reproduction known as pedal laceration, or it may occur when the anemone moves across the seafloor.
The fate of the full anemone organism that shed the cuticle remains unknown.
The findings were published on April 21, 2026, in bioRxiv and highlight the unresolved biodiversity of deep-sea fauna.