The sun's rays finish their journey in the first few hundred meters of the ocean. Below, the familiar colors gradually fade, and then comes a space where natural light no longer reaches the eyes.
But at a depth of more than 5800 meters the camera of the underwater vehicle encounters a rainbow.
Above the ancient sediment of the abyssal plain, a transparent creature hovers almost motionless. Shimmering bands run along its body — blue, green, gold, violet. It seems as though the ocean has gathered the remnants of light and turned them into a living ornament of the deep.
This is a ctenophore — one of the most fragile and unusual animals on the planet.
A little later, a violet hydromedusa appears in the lens. Its long, thin tentacles glide along the bottom, while its transparent bell contracts rhythmically, allowing it to move with the current.
Two forms of life. Two completely different ways of being in the water. And one world that continues to create beauty where the human eye almost never sees it.
An Encounter on the Abyssal Plain
The footage was filmed during the expedition NA181 — Exploration of Wake Island’s Deep Sea, which took place from 20 August to 18 September 2026. The research vessel E/V Nautilus was studying one of the least explored regions of the central Pacific Ocean.
The vehicles Little Hercules and Atalanta descended to the abyssal plain in international waters northwest of the exclusive economic zone of the Marshall Islands and southwest of the zone of Wake Atoll.
The dive depth exceeded 5800 meters — almost six kilometers of water above the cameras of the vehicles. The pressure here is hundreds of times greater than atmospheric, the temperature is close to zero, and the only noticeable source of illumination becomes the searchlights of the research equipment. nautiluslive.org
It was in their beam that a ctenophore appeared, hovering very close to the bottom.
A creature that moves like a rainbow
Ctenophores are often mistaken for jellyfish, but they are a separate group of animals — the phylum Ctenophora.
Their name comes from the rows of comb plates arranged along the body. Each plate consists of many fused cilia. Their coordinated movements push the water and allow the animal to glide smoothly.
Most ctenophores move in precisely this way. Their cilia are considered the largest structures of this type in the animal world.
When the light of the searchlights passes over the comb plates, it is refracted and split into individual colors. That is why rainbow waves run along the transparent body.
It is important not to confuse this effect with bioluminescence. Many ctenophores are indeed capable of producing light on their own through chemical reactions, but the rainbow in the video arises primarily from the interaction of external light with the moving cilia.
The result is a remarkable unity of function and beauty: a structure that helps the creature swim simultaneously turns the light falling on it into a color spectrum.
The animal creates nothing “for the viewer.” It simply moves in accordance with its nature — and beauty becomes the visible manifestation of that movement.
Threads stretched along the bottom
The camera allows us to make out the long trapping tentacles of the ctenophore, spread out above the sediment.
On them are special sticky cells — colloblasts. Unlike the stinging cells of jellyfish, they do not pierce prey with venom but instead hold small organisms that come into contact with the tentacle.
At abyssal depths, food is scattered and unpredictable. The animal does not have to actively chase it: it unfolds a delicate net and lets the surrounding water bring the necessary particles.
This is not passivity but a different strategy of interacting with the environment. The ctenophore uses the movement of the current as an extension of its own body.
Its existence is built not on resisting the water but on being in harmony with it.
The Violet Wanderer
The second animal in the video is a violet hydromedusa with extraordinarily long tentacles.
Unlike the ctenophore, it belongs to the phylum Cnidaria, which unites jellyfish, corals and sea anemones. On its tentacles are stinging cells that allow it to capture small prey.
The jellyfish rhythmically contracts its bell and slowly moves above the bottom. The tentacles follow the current and comb through the space in search of food.
What from a distance seems a simple transparent form reveals itself on closer approach as a complexly organized living system.
What did the ocean remind us of?
At a depth of almost six kilometers, the ctenophore does not try to be beautiful. It simply lives — moves, feeds, follows its nature. And when the beam of the submersible touches its transparent body, life answers with a rainbow.
Beauty is not added to the living as an ornament. Beauty is life itself in all the diversity of its forms. Sometimes it remains invisible only because our gaze has not yet been turned in its direction.
But one has only to send one's light into the darkness and look with eyes ready to see a miracle — and what seemed emptiness opens up as a whole Universe.
Sometimes a single beam is enough to see: the darkness was never emptiness — all along, a rainbow was present within it.
