They do not see the darkness in which they live. They do not hear the movement of water and possess no brain capable of remembering the past. They have no heart, no complex organs, and not even true tissues — yet their evolutionary history spans more than 600 million years, with roots reaching back long before the appearance of fish, trees, and the first animals on land.
Motionless and enormous, deep-sea sponges rise above the cold seafloor, passing thousands of tons of seawater through themselves and creating shelters for countless other creatures. In their cavities young fish and crabs raise their offspring, roe matures, and entire communities of life take shape around them. These are not merely animals — they are the architecture of an ecosystem.
And only now have nine inhabitants of these underwater forests received scientific names, becoming an official part of biology's heritage.
Nine new inhabitants of Alaska
In the autumn of 2026, NOAA Fisheries announced the description of nine species of demosponges new to science, found in the Gulf of Alaska and around the Aleutian Islands — a region that researchers have long called one of the most biologically rich in the world ocean.
Behind this announcement lies the painstaking work of two independent studies published in the peer-reviewed journal Zootaxa. The first article — “Four new demosponges from Alaska and the designation of a new genus in Hymedesmiidae” — appeared on 29 July 2026. Its authors described four new species and one new genus that simply had no place in the existing systematics. The second work, published later that same year, added five more species.
The research was led by taxonomist Helmut Lehnert of the GeoBio-Center at Ludwig Maximilian University of Munich (Germany), working in close collaboration with two NOAA specialists: Shawn Rooney of the Alaska Fisheries Science Center and Meredith Everett of the NOAA Northwest Fisheries Science Center.
An important clarification: the sponges were not discovered during a single, even the most successful, expedition. The researchers worked for years with specimens collected as incidental bycatch during NOAA's long-term bottom trawl surveys — surveys conducted for entirely different purposes: to assess the stocks of commercial fish and mollusks. The material for the first work accumulated from 1997 to 2021, while that for the second came from later collections. For decades the specimens lay in repositories, awaiting the attention of a specialist who would notice what others had missed.
It is not the specimens that are new — it is their scientific description that is new. After a careful comparison of microscopic internal structure and analysis of genetic sequences, the researchers established definitively: before them were species hitherto unknown to science.
The one that required a new genus
Particularly notable is the red sponge Polycapus rubrum — its name translates as “red multi-layered cap.”
It turned out to be so unusual that scientists could not place it in any of the existing genera of the family Hymedesmiidae. The reason? A rarest combination of microscopic skeletal elements: its wondrous architecture contains two types of specialized structural units — acanthoxeas and chelae — which had never before been found together in other representatives of this family. They simply could not coexist within a single organism, at least as far as science knows.
A new genus had to be created — Polycapus. It was necessary.
Why does this matter? A new species adds a branch to the tree of life. But a new genus is something else. A new genus signifies a deeper divergence; it speaks to an organism being so different that it does not fit even into the already known groups of related forms. It forces us to rethink the very architecture and hierarchy of biodiversity, to reconsider the connections between organisms that lived millions of years ago.
Another find — Julavis borealis — proved a genuine biogeographic revelation. Its close relatives were known predominantly from warm tropical waters — in a completely different part of the world, under different conditions. The find near the Aleutian Islands greatly extended the known range of this group, stretching it far to the north, into the cold dark waters of the Pacific Ocean. It rewrote the map of where and how these creatures live.
In total, the scientists described nine species:
- Cladocroce cylindrica;
- Julavis borealis;
- Polycapus rubrum;
- Stelletta plana;
- Aaptos mucronatus;
- Homaxinella fruticosa;
- Megaciella aurantia;
- Forcepia atka;
- Desmacella alaskensis.
After these discoveries, the number of sponge species known to science from Alaska reached 232. But this is far from the finale: by the estimates of the researchers themselves, hundreds of other species are still awaiting their discovery and description in the cold depths.
How to recognize a creature with almost no external features
Fish have fins, shape and coloration. Mollusks have a shell with patterns and tactile information. Sponges, however, are something else entirely. Externally they look like lumps, tubes, cups, branches or shapeless growths, and unrelated species are sometimes astonishingly similar to one another, like identical twins of life.
A single glance is not enough. Even a microscope at low magnification will deceive.
The key to identification is hidden deep inside — in the microscopic skeleton, built of the tiniest needle-like structures, which are called spicules. They consist of silica (the same substance from which glass is made) or calcium carbonate and differ in shape, size and three-dimensional architecture.
The method is simple in words, but very difficult in execution. Scientists make ultrathin sections of specimens, dissolve the soft tissues with acid, isolate individual spicules, coat them with a thin layer of gold (for better visibility) and examine them under a scanning electron microscope at a magnification that allows them to see miniature details: needles, stars, hooks, anchors, spirals. For each type of spicule they study not a single specimen but entire series, measure them, count them and then compare the resulting architecture with the descriptions of thousands of known species catalogued over centuries.
But even this is often not enough. In the twenty-first century, researchers also sequence (decode) sections of DNA that serve as genetic barcodes — unique identifiers. Such a combination of classical morphology and molecular analysis makes it possible to infallibly distinguish a genuinely new species from an organism whose appearance has simply changed under the pressure of the environment.
Living pumps and architects of the seafloor
On video the sponge looks motionless, but inside it there is fantastic movement.
Through a multitude of tiny openings, water enters a complex system of channels, where bacteria, microalgae and particles of organic matter are extracted from it. A sponge is not merely a hunter of food; it is a filter that cleans the water. Then the filtered, enriched and purified water is expelled outside.
This work is far more than personal feeding. Filtration participates in a colossal transfer of nutrients through the entire water column, in maintaining water quality, in the cycles of chemical elements. Large aggregations of sponges are capable of noticeably changing the conditions around themselves: temperature, acidity, the content of oxygen and nutrients, influencing the entire local ecosystem balance, like the chief engineers of an underwater city.
But their role is not exhausted by filtration.
On the relatively uniform seafloor, vertical and branching sponges create architectural complexity — like a vast forest arising out of a flat plain. Between their folds and cavities, sheltered niches appear where the young can hide from a predator, survive a strong current, or find food that hangs in the water.
Young rockfish and crustaceans eagerly use sponge fields as refuges and nurseries. Golden and red king crabs find protection among them during the early, vulnerable periods of life and immediately after molting, when the shell is soft. Some species of sea sculpins deposit their eggs directly in the cavities of large sponges: a constant flow of water supplies the clutch with oxygen, while biochemical substances produced by the sponge itself can suppress the development of dangerous microorganisms and fungi.
For this reason, NOAA classifies dense deep-water sponge communities as critically important fish habitats — Essential Fish Habitat. They are not secondary; they are irreplaceable.
Before us are not solitary organisms scattered across the bottom like random objects. This is a living infrastructure on which an entire world rests.
DNA left behind in the water
The authors of the studies not only described the structure and internal architecture of the sponges, but also generously shared: they added new genetic sequences to open international databases accessible to any researcher in the world.
This is critical for one of the most promising methods of studying the ocean — the analysis of environmental DNA (eDNA). Living organisms constantly leave in the water microscopic traces of their existence: dying cells, mucus, fragments of tissues, molecules of genetic material. This is the molecular autograph of life.
By examining a sample of seawater, even of low quality, scientists can determine the presence of species without seeing or catching them alive. This opens up incredible possibilities: monitoring without harm, observation without disturbance. But for this, the discovered genetic sequence must be compared with a reference. If there is no reference in the database, the organism will remain unrecognized, its signal will be lost in the noise of the unknown.
That is why the description of a new species and the creation of its DNA barcode complement the growing dictionary of the ocean's life. In the near future, it will make it possible to find sponges by their traces in the water and to monitor biodiversity without destroying the fragile communities on the bottom.
A memory that needs no brain
When speaking of the memory of the ocean, we use a metaphor, an image, a poetic device. Sponges do not remember the past in the sense of human consciousness, thought, recollection.
But their bodies truly embody the results of a vast, most profound evolutionary history.
Every spicule, every channel, every chemical compound bears the imprint of countless generations that found ways to survive in the cold, in complete darkness, under the enormous pressure of water at a depth of kilometers. This memory is recorded not in neurons and synapses, but in form, in the genetic code, in structure, in chemistry, in symbiosis with microorganisms.
A sponge does not exist in a vacuum. The flow of water brings it food and information. Its body becomes a home and refuge for other animals. Microorganisms participate in its metabolism, help it to live. Fish and crabs are born and grow in sponge gardens, becoming stronger. All of this is a system, not a collection of random facts.
Thus the ocean once again reveals to us its chief principle: resilience arises not from isolation and self-sufficiency, but from interaction, from connections, from what ecologists call connectivity.
What did the ocean remind us of today?
Nine species received their names only in the autumn of 2026, although some specimens had lain in repositories for decades, awaiting a specialist's attentive gaze. All that time they had already been part of the living ocean — regardless of human recognition, regardless of whether we knew of their existence.
Life does not begin at the moment of our discovery. At that moment, only our vision of it expands; our map of the unknown becomes a millimeter more complete.
And perhaps the true scale is revealed precisely in this way: we notice the one who remained invisible, and we understand that even the quietest, the most motionless, the most ancient being occupies in the integral system of life its own single, irreplaceable and precious place.
