It can reach eight metres in length while remaining an almost weightless silver ribbon in the water column.
The oarfish does not cleave the ocean with powerful strokes of its tail, nor does it bend its whole body like an eel. Instead, a barely perceptible wave runs along its back. Hundreds of thin rays rise, turn, and pass the movement on to one another — and the enormous creature glides forward soundlessly, retreats backward, or hangs motionless in a vertical position.
The ocean seems to show us movement in which there is no struggle.
Each part retains its freedom, yet by coming into accord with the others it becomes a single wave.
A fish that resembles a silver ribbon
Oarfishes, or ribbonfishes, belong to the family Regalecidae. They are among the most mysterious inhabitants of the open ocean: they are rarely encountered alive by humans, and their long, fragile bodies often break apart after death. That is why whole specimens suitable for detailed study are found infrequently.
The largest individuals can reach approximately eight metres, which is why the giant oarfish is considered the longest of all living bony fishes.
Despite its impressive size, it feeds mainly on small crustaceans and other tiny organisms. While feeding, the fish is able to hold an almost vertical position — head up, like a silver column suspended in the water.
A fin that runs along almost its entire back helps it control such a long body.
It is precisely in its structure that scientists discovered a mechanism that had not previously been described in detail.
Hundreds of tiny movements — one wave
30 September 2026 in the peer-reviewed journal Ichthyology & Herpetology a study was published Dorsal-Fin Musculoskeletal System of Oarfishes (Regalecidae): Fin Rays as Rotating Elements in an Undulatory System.
The first author of the work was Gabriel Afonso, a researcher at the Virginia Institute of Marine Science. The international team also included ichthyologists, engineers, and specialists from Cornell University, the Smithsonian Institution, NOAA Fisheries, and other scientific organizations.
To study the fin, the researchers combined several methods:
- anatomical dissection;
- histological analysis of tissues;
- X-ray imaging;
- computed tomography;
- the study of video recordings of live oarfishes.
It turned out that each ray of the dorsal fin is connected to cartilage, muscles, and a joint resembling a hinge. Thanks to this, it is able not merely to tilt forward or backward, but to perform an almost circular rotation — like a miniature joystick.
There are hundreds of rays, and each possesses a certain independence. However, during movement they do not act chaotically. Their rotations are coordinated and transmitted along the thin membrane of the fin, creating a travelling wave.
Thus a multitude of small movements turns into a single flow.
Swimming forward and backward while barely moving the body
Most elongated fishes move by means of undulating bends of the entire body. The oarfish is capable of using that method as well, but its main advantage is its long dorsal fin.
The fish can direct the fin's wave in one direction and move forward, then change its direction and retreat backward. Moreover, different sections of the fin are capable of simultaneously creating waves travelling in opposite directions.
This gives the animal extraordinarily fine control over its position in space.
The enormous body hardly sways at the same time. The fish maintains a vertical position, slowly approaches its prey, or hangs suspended in the water column without making any abrupt movements.
Scientists call this manner of locomotion ribbon-fin swimming — swimming by means of a ribbon-like fin. Such a system arose independently in bony fishes approximately ten times. However, researchers have yet to determine whether other species use equally mobile rotating rays.
When the ocean becomes a teacher of engineers
The oarfish's unusual fin caught the interest of Rob Shepherd, a professor of mechanical and aerospace engineering at Cornell University.
He was pondering the creation of a large underwater robot that could move quietly enough not to scare off fish and other marine animals. Such a device could potentially carry instruments for monitoring the state of the ocean, move forward and backward, and approach living creatures without intruding into their space with the noise of a motor.
However, to reproduce the natural solution, its structure first had to be understood. Thus the engineering task led to a collaboration with the ichthyologist Willy Bemis and to the first detailed description of the mechanics of the oarfish's fin.
It is important to clarify: the study does not report the creation of a finished oarfish robot. For now, what lies before us is an anatomical discovery and a biomimetic idea — the possibility of transferring a principle found by nature into future technology.
But the direction itself changes the familiar logic of design. Instead of forcing a machine to overcome the resistance of water with greater power, one can teach it to distribute movement — gently, silently, and in concert.
Not to overcome the water
We are accustomed to associating strength with great effort: to move faster, one must push harder, accelerate, overcome resistance.
The oarfish offers a different geometry of movement.
Not a single individual ray of its fin is capable of moving an eight-metre body. But hundreds of rays, joined by a membrane and acting in concert, give rise to a wave that carries the entire fish.
Here the water does not become an adversary. It receives the impulse and continues it.
This does not mean a complete absence of physical resistance — the laws of hydrodynamics do not disappear anywhere. However, the shape of the body and the work of the fin allow the animal to interact with the aquatic environment with extraordinary subtlety, without expending movement on strong lateral oscillations of the entire body.
This is precisely where the perfection of the solution found lies: not to abolish the properties of the medium, but to unfold one's own possibilities within it.
What has the ocean reminded us of?
The oarfish does not overcome the water — it creates movement together with it. Each ray of its fin retains its independence, but, entering into accord with the others, becomes part of a single wave.
By the law of analogy, the same principle is recognized in man as well. Each of us is a unique ray of Creation with our own frequency, direction, and gift. Unity does not require that we become identical or renounce our own nature. On the contrary, the whole gains strength precisely through the uniqueness of each of its parts.
When each takes its own place and freely expresses the qualities inherent in it, individual impulses join together. A common movement arises, capable of manifesting what no one could have created alone.
The ocean does not overcome itself — it moves through each of its forms.
