During 2023, within abyssal depths where solar illumination is nonexistent, researchers utilizing a submersible craft made a peculiar discovery at the ocean floor.
A luminous, globular mass composed of golden material was firmly affixed to a rocky substrate, its sheen reflecting the intense illumination from the remotely operated vehicle (ROV) Deep Discoverer, presenting an unprecedented sight.
Initial hypotheses leaned towards the enigmatic object being the detached egg casing of an abyssal organism. After a three-year investigation, definitive answers have emerged, revealing an outcome divergent from early conjectures.
Nevertheless, the revelation retains a profound strangeness: the incandescent tissue mass was identified as a fragment of ‘skin’ shed by an extraordinary sea anemone, possibly dislodged during the creature’s relocation or as part of its reproductive cycle.
Meticulous analysis successfully identified the species: Relicanthus daphneae, a cnidarian inhabiting the deep sea, characterized by tentacles capable of extending over 2 meters (6.6 feet) in length.
The initial sighting of the amorphous mass, approximately 10 centimeters (4 inches) in diameter with a discernible aperture, elicited both bewilderment and excitement among the scientific community. It was located adhered to a rock formation at the base of the Gulf of Alaska, at a depth of roughly 3,250 meters (approximately 2 miles) beneath the ocean’s surface.
These extreme depths are characterized by frigid temperatures, perpetual darkness, and immense hydrostatic pressure – significant impediments to direct human scientific inquiry.
Personnel aboard the NOAA research vessel Okeanos Explorer encountered the unusual formation while monitoring a live video feed from the remotely operated vehicle Deep Discoverer.
“The nature of this object is still unclear,” remarked one of the participating researchers during a live broadcast of the expedition in 2023.
“It clearly possesses a substantial opening; suggesting either an attempt at ingress or egress,” another observer hypothesized.
“My apprehension is that upon investigation, a creature might emerge,” a scientist commented. “It evokes the commencement of a suspenseful narrative.”
The specimen was carefully retrieved via the ROV’s manipulator arm and transported to a laboratory for detailed examination, with initial expectations suggesting it might be an egg case, a deceased sponge, or coral. However, the enigma only grew more intricate.
“Having processed countless samples, I anticipated our standard analytical procedures would readily resolve this anomaly,” stated zoologist Allen Collins of NOAA Fisheries’ National Systematics Laboratory.
“Yet, this particular case demanded dedicated efforts and specialized knowledge from multiple specialists. Deciphering this complex puzzle required proficiency in morphology, genetics, deep-sea biology, and bioinformatics.”
Investigators determined that the collected sample lacked the typical anatomical features anticipated in a marine animal.
Instead, it exhibited fibrous characteristics and contained numerous stinging cells, known as cnidocytes, which are characteristic of corals and anemones. Specifically, the cnidocytes identified were spirocysts, exclusive to cnidarians belonging to the Hexacorallia order.
However, at this juncture, the investigation encountered a significant hurdle.
Preliminary DNA analysis proved inconclusive due to the dense presence of various microscopic organisms within the mass. It was only through comprehensive whole-genome sequencing that researchers successfully established a close genetic correlation – R. daphneae, a species first documented in 2006.
The researchers elucidated that the observed mass is, in fact, a cuticle shed by one of these anemones. This cuticle is a delicate, stratified outer layer secreted by the peripheral tissues of certain anemones, forming pliable, sheet-like structures that can detach and persist on the seabed.
Its primary constituent appears to be chitin, a robust, fibrous material also forming the external structures of other organisms, such as insect exoskeletons and fungal cell walls.
“In situ observations of these organisms suggest that the cuticle is shed as the animal moves, indicating the creature’s capacity to detach itself from it,” the researchers documented.
Collected specimens of R. daphneae rarely exhibit a cuticle; this mobility and shedding capability may account for its infrequent presence. The discarded cuticle might also offer insights into the creature’s reproductive mechanisms, a process that remains challenging to apprehend for organisms inhabiting such inaccessible environments.
“While genetic and morphological data confirm the identity of the organism in question, the precise formation of the golden orb remains an elusive puzzle,” the researchers articulated.
“One plausible interpretation posits that the orb represents a residual product of incomplete asexual reproduction. Certain sea anemones are capable of pedal laceration, a process wherein the basal portion of the polyp is abandoned, and the superior section of the organism relocates, leaving behind a segment of its body that subsequently regenerates into a new polyp.”
The abundant presence of microorganisms on the cuticle suggests its potential role as a micro-habitat fostering microbial activity, where these organisms consume and decompose the degrading tissue, playing a crucial part in the nitrogen cycle.
Thus, the enigma is resolved: an anemone shed its outer covering, inadvertently providing sustenance for the microfauna.
“This underscores the imperative of continued exploration – to unveil the profound secrets of the deep and enhance our comprehension of how the marine environment and its resources can foster economic prosperity, bolster national security, and ensure planetary sustainability,” stated Captain William Mowitt, acting director of NOAA Ocean Exploration, according to a NOAA announcement.
A preliminary report detailing the team’s findings is accessible on bioRxiv.
