The Biology of Subnautica | Full Documentary

The vast oceans of the video game Subnautica and its sequel Below Zero are teeming with incredible life, some friendly and some deadly. While the series focuses on survival, the life forms of Subnautica are amazing even when they try to eat you: they have fascinating

biology

, strange behavior patterns, and hidden mysteries. I've explored the various creatures from the series before on my channel, and in this special compilation episode, you can get the

full

documentary

-style experience in one video. From the sunlit shallows to the deepest abyss, we'll explore the

biology

behind these puzzling aliens and discover the role they play in their larger ecosystems.

So let's take the plunge together and see what awaits us beneath the surface... Starting with the safety of warm, shallow waters, we discovered that stable conditions have given rise to a region teeming with varied life. One of the first life forms we can detect are the Peepers... or rather, they detect us, with their enormous eyes like saucers. These easily identifiable creatures have developed visual sensors capable of discerning colors not only in clear water but in a variety of lighting conditions. This, combined with their surprising speed, means that, despite being herbivores, Peepers are not at the bottom of the food chain.

Instead, that distinction belongs to these rather unfortunate-looking creatures, the Garryfish. Docile and remarkably slow herbivores, Garryfish are easy prey for almost anything else in these shallow waters. After all, all ecosystems, including Earth's oceans, need something near the end of the food chain. Other common herbivores on 4546B include the bladderfish, which swims by contracting and expanding its translucent bladder, and the unusual boomerang, a horizontally symmetrical rarity that possesses a mouth

full

of sharp teeth for breaking up coral. As for corals, the Safe Shallows landscape is dominated by a particularly unusual form of life. These gigantic tubes are large enough to swim through and, despite appearances, are very much alive.

Aptly named Giant Coral Tubes, they don't look much like the corals we know on Earth. These tubes have evolved to filter the nutrients that flow through their center and, judging by their size and abundance, it is a strategy that has proven quite successful. Gliding close to the tubes is the elegant rabbit ray, the first of many species of rays we can find. The undulating motion that the rabbit ray uses to swim through crystal-clear seas is analogous to the underwater movements of several types of terrestrial rays. But it is not the movement of the rabbit ray that gives it its curious name.

Instead, Rabbit Ray's most defining features are his twin orange appendages that help him sense vibrations. These ear-like structures tangentially resemble rabbit ears, so the aquatic rabbit ray shares a name with an otherwise different terrestrial herbivore. Beneath the shallow waters lies a network of underwater caves. While exploring one while collecting these images, I heard a strange noise… And a fish exploded in my face. That short-lived creature was a Crashfish, an evolutionary oddity that's difficult to study because of its frustrating habit of exploding when something approaches. Crashfish is defending the sulfur plant, which provides it with its home.

While an animal that exploits itself to defend its territory may seem too extravagant to evolve, a model of such behavior exists on our own planet. Although rare, certain species of ants have been observed to erupt a slimy substance to block tunnels when their nest is threatened. In truth, nature is very unusual, no matter the planet. Elsewhere in the caves, the much less annoying Shuttlebugs roam near the stone walls. Shuttles are difficult creatures to understand: they have three legs and three jaws that have evolved into fin-like tentacles. Despite looking a little disturbing, the analysis suggests that shuttles are too small to be a threat to most organisms and have instead adapted to feeding on waste products from the surrounding ecosystem.

When you leave the caves, you will see that our first great species awaits us: the gasopods. These large, leathery beasts resemble terrestrial manatees, but they have a curious defense of their own. Although they are in no way hostile, when threatened, gasopods release a deadly cloud of underwater mist... which I do not recommend ingesting. Chemical analysis of gasopods tells us that the poisonous compound comes from the bulbous appendage at the end of its tail. Since gasopods are social creatures, they may even use these clouds to communicate with each other. But while gasopods are the largest creatures in Safe Shallows, they're barely the tip of the proverbial iceberg when it comes to planet 4546B.

As we venture into the vast Kelp Forest, we will find an environment radically different from the region we have just left. Here, light is scarce thanks to the large volume of climbing plants, creating a hidden ecosystem, much like the seaweed-rich regions of Earth's oceans. Here and there, clusters of Creepvine Seeds cast shadows on the environment like natural spotlights. I wonder what could be hiding among the swaying leaves... That's a Stalker: the largest predator that makes its home in the dense Creepvines. These fearsome clients have a series of dorsal ridges that help them make tight turns. Its long, thin snout is probably adapted for catching fish, as it closely resembles the thin, effective snout of real-life gharials.

However, at the edge of the Kelp Forest, a Stalker is behaving... rather strangely. This Stalker is picking up several pieces of scrap metal with its snout, only to drop them after a short period. This behavior appears to serve no practical purpose, and in fact, bullies seem to simply have a fondness for shiny objects. As puzzling as this behavior may seem, the barracuda, a predatory terrestrial fish, is also known to be attracted to shiny objects because it has evolved to detect the silvery sheen of the fish it prefers to hunt. And when one considers the Stalker's common prey, this attraction to shiny materials makes a lot of sense.

In the murky depths of the kelp forest, schools of fast-moving hoopfish light up the darkness with their vibrant colors. A brief study of hoopfish anatomy reveals that they get their name from their antennae, which extend from the top and bottom of the head and bend around the tail, forming a hoop. However, it is a mystery exactly why these impressive fish have such intense and varied colors. Speaking of mysteries, the last kelp forest fish we'll see is quite an enigma. Meet the Hoverfish: a peaceful herbivore that appears to "hover" on pads at the ends of its six legs.

Using these strange appendages, the Hoverfish glides on underwater currents in a manner quite different from any other fish on the planet. It is surprising to learn, therefore, that the floating fish may actually be a distant relative of the nondescript bladderfish, its "legs" being a highly derived form of the bladderfish's primitive tube vacuole. It is the type of creature that could only exist in the Kelp Forest. Just beyond the rolling Creepvines, the landscape gives way to a strange Grassy Plateau. Here, the sandy terrain is almost completely covered in Blood Grass, as the seafloor is too deep for Creepvines to gain a foothold.

And in the open space, even larger life forms lurk... At the edge of the Grassy Plateau, a strange cloud of sand is gathering. Be careful: as we swim closer to the unexpected turbulence, a creature with a huge fanged mouth lashes out. This is a sand shark, a predator with a distinctive hunting strategy. The sand shark hides in the sand and then darts out when unsuspecting prey swims past it—ending the chase with a snap of its enormous jaws. With segmented body armor and six rows of fearsome teeth, it's no wonder why these predators are so effective.

As strange as this behavior may seem, some sharks on Earth employ a similar strategy by swimming along the sandy ground near the shore in search of food, although they do not possess the extreme tunneling abilities of the sand shark. A common target of brutal sand shark ambushes swims overhead. Swordfish don't look like much from most angles, but glimpse one from above and you'll see its defining characteristic: a single cyclopean eye. Closer analysis of the swordfish suggests that it feeds on the sea floor, and its single eye allows it to detect predators above it. Its mottled green coloration suggests that it normally hides among seagrasses as many fish do on land.

However, when a swordfish wanders onto the Grassy Plateaus, it becomes hopelessly exposed... On the other side of the Grassy Plateau, what appear to be small floating islands miraculously hang in the water. Upon closer inspection, these chunks of rock are suspended by colonies of the same curious life form: Floaters. The transparent, gelatinous blobs, the floaters, are both strangely beautiful and a little silly. The analysis of these creatures reveals that they are actually multiple microorganisms that live in symbiosis, which we can compare with some species of deep-sea jellyfish. However, the float's ability to suspend such heavy objects remains a mystery.

Swimming near the floating islands is a distant relative of the peeper named Reginald. The entire rear part of these strangely named specimens is made up of a large tail fin, and the bright coloration of the fin appears to be part of a mating ritual. Biologists believe Reginald filters algae and other plant material from the water through four forward-facing gill-shaped holes. While this is a noteworthy adaptation, something looming behind Reginald demands our attention. In the abyss beyond the edge of the plateau, the largest organism we have yet to glimpse screams from the depths. This is a Reefback: a leviathan-class organism that exceeds 220 feet or 70 meters in length and, fortunately, is quite friendly.

Swimming closer to these gentle giants, we can see that they are unlike any life form we haven't yet glimpsed. Possessing a thick exoskeleton, their shells have become an oasis of life. Adult reefs can support mini ecosystems on their backs: including many types of corals and small fish. And near this adult is its baby: a much smaller creature whose shell is not yet ready to support an ecosystem like its parents. I confess that I spent some time watching these creatures float in their capsules, listening to them call to each other with complex sounds that suggest a surprising amount of intelligence.

Now that the sun is setting, it's time to venture deeper into the abyss and enter the foreboding final Dunes biome. In this fast, empty expanse, life often congregates near hydrothermal vents. These large fissures in the sea floor release a rich chemical soup into the water, much like those that support life in the depths of Earth's oceans. But it's not the life between the vents that worries me... A terrifying roar comes from above. A Leviathan Reaper attacks in the abyss. This aggressive predator has four jaws at the front of its jaws to drag large prey. And at 180 feet, or 55 meters long, a hungry Reaper Leviathan can take down almost anything.

Analysis of the organism's biology suggests that the deep roar emitted by the Reaper is a form of sonar, meaning if you can hear it, the Reaper can see you. Fortunately, it seems that this Reaper is not hungry. And as I watch the deadly leviathan disappear into the darkness, I realize that I've done enough legwork for today... The sun has already set on 4546B. However, the wonders of this planet continue, as in low light conditions, various regions of the sea are transformed by impressive displays of bioluminescence. Even the Reefback capsule from before now emits a surprising brightness.

This mysterious beauty suggests the many hidden wonders we have yet to see. To the north, beyond the grassy plateaus, huge tree mushrooms grow in abundance. Despite their name and appearance, mushrooms are actually a particularly long-lived species of coral. In the shadow of these ancient giants, a new classification of life swims. These are Jellyrays: a kind of ethereal ray with very translucent bodies. In Earth's oceans, translucent life forms are quite common in the low-light depths. The Jellyrays are a sign that we are approaching the deepest and most fantastic regions of4546B. Beyond the safety of the Mushroom Forest, the twilight of the Bulb Zone awaits.

Here, luminescent bulbs dominate the landscape and have evolved to grow in this rocky and sandy environment thanks to a highly advanced root system. And along the sea floor, raging volcanic geysers spew boiling liquid and chunks of molten rock into the surrounding water. The extreme heat from these geysers chars any fish that swim too close. An ominous light flickers in the darkness. The source is an ampeel: a huge serpentine predator covered in glowing spikes that produce electrical discharges. These aggressive creatures use electric shocks to intimidate other predators and kill their prey with a single deadly discharge. These living batteries may seem biologically inexplicable, but Earth's curious electric eel could help demonstrate how a creature could produce electricity.

Electric eels use disc-shaped cells packed into specialized organs to generate their electrical currents, incredible as it may seem. It is possible that the tips of the ampeel contain similar cells, although the bioelectricity of the ampeel is much more extreme. A series of screeches announce the approach of a legion of Bonesharks. Very aggressive and territorial carnivores, it is unlucky to find so many at once. Their thick armor exoskeletons that give them their name are adapted not only to deter larger predators, but also other bone sharks. The distinctive segmentation of these exoskeletons suggests that Bonesharks could share a distant relative with the Sand Sharks we glimpsed in our last outing.

If so, it's a scary family tree. As I head back into the shallows to prepare for the next leg of my journey, I spot a new type of colorful fish. There is something about his appearance that is truly hypnotic and I want to swim closer and closer… And then he bites my nose. This is a Mesmer, a cunning little creature that appears harmless when its four fins are folded, but when deployed can create hypnotic patterns that have evolved to distract prey while it prepares to kill. Fortunately, it seems I'm too big to be swallowed, but this is a fish I should avoid.

With supplies replenished, it's time to venture further into the unknown. Beneath the seafloor, networks of caves lead deep into the unexplored interior of planet 4546B. Some of these caves are huge and contain entire ecosystems of their own. And the Jellyshroom cave is one of the most miraculous. Here, among the stalagmites, jellyfish grow: a massive, highly luminescent flora that could be distantly related to the tiny acid fungi of shallow waters. In the violet light of the Jellyshrooms shine the Biters: small carnivores that lurk in the caves in search of small prey. The antenna on its forehead appears to resemble the deepwater anglerfish lure at first glance, but the Biter's antenna actually serves a completely different purpose.

It contains olfactory organs that help it detect body fluids in water. In other words, the Biter can smell its prey anywhere in the cave. Unless, of course, the Biter becomes prey. Snaking through the cave is a disturbingly long crab snake – the apex predator of this environment. What makes this predator so deadly is not only its size, but its ability to hide in plain sight. The crab snake has a symbiotic relationship with the local jellyfish fungus: it uses its hollow interior as the perfect lair from which to ambush its prey. In behavior and appearance, the crab snake looks a bit like Earth's Bobbit worm: an unattractive predator that also ambushes its prey.

In the Jellyshroom caves, you have to be careful... Elsewhere on the seabed, another shadowy cavern beckons us. After many hours navigating the cave system, I surface in a cave that, strangely, appears to be illuminated by… daylight? I realize that I have stumbled upon something extremely rare on planet 4546B: solid ground. This small island is the top of an underwater mountain connected to an aquatic cave system and is one of the few places on the planet where you can find terrestrial life. Sneaking along the beach are Cave Crawlers. As their name implies, these crab-like creatures have evolved to crawl along the sides of cave walls: which is probably why they can adapt to this fleeting landmass relatively quickly.

Analysis of their biology suggests that they possess a gas exchange membrane for breathing air, rather than fully functional terrestrial lungs. Hovering overhead is a way of life that has spent much more time adapting to life. This is a Skyray: an avian creature that, surprisingly, has evolved powered flight. Although its wings give it some resemblance to aquatic stingray species, the analysis does not show any particular genetic link. Instead, Skyray seems to have branched off the evolutionary tree long before most other species on the planet, perhaps at a time when dry land was more common... In any case, it seems we've now seen everything. that the island has to offer. .

Or maybe not. At one end of the island there is a tremendous artificial spire. This mysterious monolith appears to be the work of advanced aliens who, like me, came to this planet from afar. But did they come to study life here, or were their intentions more sinister...? In any case, it seems that this planet's biggest secret is still waiting to be discovered... Towards the south, the seabed is sinking more than ever. We have arrived at the Great Reef. Here, blue orb-shaped plants called anchor pods are at risk of floating due to their gas-filled membrane and only stay in place due to their web-like root system.

And nearby tramples a pack of Sea Treader Leviathans. These enormous herbivores roam the depths in search of plants to graze on. The thunderous nature of his rhythmic steps is truly something to experience. Perhaps the most curious thing about these creatures is the fact that they have three legs, something that is almost never seen in nature. Analysis suggests that its front leg is actually an elongated snout, used to extract plant material from the sea floor and to maintain balance. Strangely enough, there are some species of terrestrial tripod fish with elongated fins that they use in a similar way to stay on the sea floor.

Right now, it seems that the Sea Treaders are migrating, so it's best not to disturb them... Below the Great Reef, the caverns take us further into the abyss. Here, the intimidating crab squid waits to slaughter its prey with its ten limbs. Swim near one and they will unleash a mysterious bioelectric discharge: one that has the properties of an electromagnetic pulse. While they appear to have enormous brains, analysis suggests that the large organ inside their translucent sac is actually their stomach, which the squid fill with their bioluminescent prey. As a result, they seem attracted to light sources, convincing me to hastily exit my sub.

This turns out to be a good decision, as it drags my submarine into the depths. If there are other creatures like the crab squid lurking, I'll need something a little bigger... For the next dangerous leg of the journey, I'll be piloting a 'Cyclops' submarine: a vehicle that should be able to withstand the crushing depth of the abyss. Beneath the deep Great Reef awaits a surreal environment of mysterious green mist. This is the Lost River, a region covered in pools of alkaline brine, which give the illusion of an underwater current. Brine puddles also exist in Earth's oceans and are extremely toxic due to their high salinity.

It's best not to get too close... Above these pools float haunting ghost rays. Relatives of the Mushroom Forest Jellyrays, at these extreme depths, Ghost Rays have become almost completely transparent, to the point that the red of their internal organs can be seen. Elsewhere in the Lost River, Blood Crawlers, the slender relatives of Cave Crawlers, walk on brine with stilt-like legs. Quite disturbing life forms... Something truly terrifying awaits us in the central chamber. Or rather, it would be if this leviathan were still alive. This ancient fossil belonged to a colossus much larger than any currently swimming in the seas.

In fact, it is so enormous that its ribs have become part of the landscape of Lost River. We should consider ourselves lucky that this unknown genus seems to have long gone extinct... However, the River Prowlers are still alive. These aggressive, transparent predators haunt the leviathan's tomb like vengeful ghosts. Even more terrifying is that their four tendrils on their heads can lash out when they attack, allowing them to lure in their prey. It's not the kind of creature you'd want to find in the dark. But there is a strange beauty in certain regions of the Lost River.

In a cove below the central chamber, the brine turns a harmless blue and ghost rays gather around a massive tree. This tree appears to be an ancient nesting site, as it has grown around a giant bioluminescent egg. While the egg is beautiful, whatever hatches from an egg that size may not be... To find the adult form of the enormous creature that hatches from this egg, we must venture into the nightmarish darkness of the Dead Zone. . Here, at the edge of the habitable region for most faunal life, we have found our giants... or they have found us.

These aggressive monsters are Phantom Leviathans and pose a major threat to this expedition. Analysis of their jaws suggests that they feed on microscopic life forms that help them reach enormous sizes, although they also seem fully capable of feeding on something larger. It's time to go back the way we came... The mystery of the giant egg has been solved, but that's not the only strange thing in Lost River. These ruins of a huge alien structure resemble those on the island. The structure is guarded by these life forms, the Warpers, who possess mind-blowing ability. At will, they can somehow fold space-time and disappear into portals.

This is not the capacity of a natural life form; It seems that we are facing an artificial creation. Searching for answers, he entered the ruined building. Here we can see the unfinished artificial body of a Warper, confirming that they did not evolve naturally and are a creation of aliens. But for what purpose? Translating a digital message, it appears that these alien architects came to 4546 B many years ago in search of a cure for a disease, and the Warpers are their artificial quarantine enforcers. Given the lack of living architects in 4546 B, it seems they were unsuccessful... On a table in a nearby laboratory, they left the egg of a curious creature.

After returning to the surface to recharge my submarine, I hatch the egg and this lovely life form emerges. This is a Cuddlefish: a friendly, rotund little creature that displays high levels of intelligence and curiosity. I also discovered that he is a big fan of candy. Analysis suggests that this creature may have been imported from another world, or even genetically modified to be friendlier. It is possible that the extraterrestrial architects kept them as pets just as we do with dogs. It's tempting to stay with the Cuddlefish in the shallows, but I can't help but feel that there are more mysteries in the abyss that I have yet to solve...

Below the Lost River, the landscape shimmers with the fiery glow of molten rock. . We have reached the Lava Zone: the deepest environment of all. Incredible, heat-resistant life forms have evolved here: like the crimson stingray, a species of stingray that has evolved a mottled color to help it blend into the lava. And the Magmarang: a relative of the Boomerang with a beautiful shiny tail fin. Another notable life form is the lava larva, a larva-like creature that feeds on geothermal and electrical energy. I first learned of this fact when I found one stuck to the windshield of my Cyclops, draining its energy.

While this behavior is somewhat annoying, this creature's energy conversion capabilities are truly remarkable. On the molten ground there is something extremely alarming. These skeletons belong to Reaper Leviathans. It seems that somewhere in the Lava Zone there is a predator so large that it can drag Reaper Leviathans into the depths. This does not bode well... Basking in the red glow of the molten rock are the lava lizards. These predators are too small to be our culprits, but they are still quite deadly. To defend themselves, they can cover their bodies with hardened lava like natural armor. While this behavior is much more extreme than anything on Earth, scaly-footed snails, which I've talked about before on this channel, can survive in volcanic vents by incorporating scales ofiron on his body like medieval armor.

However, the biology of the Lava Lizard takes this to a new level. At the end of the Lava Zone a huge chamber is hidden. The loudest roar we have encountered on our journey shakes the cavern. We have found our assassin Reaper Leviathan. This is a Sea Dragon Leviathan. Possessing arms and tentacles, these creatures exceed 350 feet or 112 meters in length. Sea Dragons are named for their ability to consume molten materials and expel them towards their adversaries as if they were breathing fire. I can only hope that this absurdly deadly life form doesn't notice me... I'm not so lucky.

A huge blow from the Leviathan shakes the cyclops submarine. As a result, there appears to be a… “minor” leak. With no options, I have to abandon ship. Fortunately, I have one last hope in the Prawn Suit: a mechanical deep-sea walker that should make an ideal escape pod. Ejected from the cyclops, it is a small drop to the bottom. But it seems that my plan has worked, since the Leviathan Sea Dragon believes that his enemy has been defeated. Here, at the end of our journey, is one last mysterious building. With some difficulty, I drive the shrimp suit there.

Inside, locked in a containment facility, Subnautica's largest creature awaits. This is a Sea Emperor Leviathan, and although he appears to be a relative of the Sea Dragon, he is in no way hostile. Like real-world baleen whales, the largest creatures on Earth, their diet consists solely of microorganisms. While the Sea Emperor Leviathan is so large that I cannot scan it properly, it appears that it can manipulate neurons to communicate telepathically, as it told me of its plight. The Sea Emperor was buried here by the alien architects in the hope that he could provide a cure for his illness, which I believe constitutes a strict violation of the intergalactic code of biological ethics.

At the request of this intelligent creature, I agree to take its young to the surface. Seeing the first moments of the lives of Sea Emperor babies is a truly wonderful experience: even after all the biological wonders I have glimpsed so far. Unfortunately, the Sea Emperor is at the end of her lifespan and informs me that she will not be coming with us. At the very least, I'm happy to help your babies live in freedom. It's a bittersweet conclusion to a long and winding journey... With the return of the Sea Emperor babies to their natural habitat, our study of this region of Subnautica has come to an end.

But there is another region of Planet 4546B. Sector Zero is a region of extremely low temperatures, where organisms of all types have had to adapt to the cold. Beginning with the ice floating on the shallow waters, a curious way of life makes its home in this region where land meets sea. Huddled on a float is a flock of Pengwings waddling around. Pengwings are a small, predatory fauna that… are not the most graceful on land. However, when a Pengwing dives underwater, the creature's unique retractable tail allows it to spin through the currents with remarkable grace. Despite their appearance, Pengwings are carnivorous and their beak opens horizontally, revealing a rather alarming set of teeth.

In their body shape and behavior, Pengwings show a high degree of convergence with land penguins, and both species adapt to an Arctic environment in similar ways. And on any ice float with Pengwings, you'll also find Penglings, the juvenile form of Pengwings that never strays far from their parents. Even more so than adults, Pengling babies are extremely uncomfortable with land. But what they might lack in terms of overall balance, they make up for in endless enthusiasm. And while Penglings may possess the same, somewhat alarming, fanged mouth, they are remarkably docile creatures, perfectly content to be gently picked up.

However, as nice as it is to briefly hold a baby Pengling, I don't want to disrupt their natural routines... As we dive into the polar waters, a shallow and surprisingly warm region awaits us just below the ice floats. The landscape of this coastal sea is dominated by Coral Bridges, large arches formed by fast-growing coral polyps that can exceed 600 feet or 200 meters in length. Bioluminescent blue barnacles grow on the underside of the coral, which a scan suggests are actually a separate species that takes advantage of the structure of the bridges. But why would coral bridges grow into such strange arched shapes?

The answer lies in a phenomenon known as thigmotropism, a growth pattern observed in land plants in response to touch. Thigmotropism is what allows vines to coil and 'climb' up poles, and is probably the reason why large coral bridges always grow from one rock to another... Just beyond these coral bridges, We meet an arctic peeper, which observes predators with its enormous yellow eyes. Relatives of the common peeper in tropical seas, the scales of arctic peepers have developed a whitish hue to better camouflage themselves against the ice. Other familiar herbivores also swim here, such as the translucent bladder fish and the vibrant ring fish.

Together, these species form an important base in the Sector Zero food chain for the larger, less familiar creatures that lurk beneath the ice. Swimming north, I came to a region known as the Low Arctic. This entire biome is situated under thick ice shelves and receives little direct sunlight. At the bottom of these icebergs, dangerous ice formations known as Brinicles protrude like jagged fangs. Highly unstable, Brinicles frequently break apart and fall to the sea floor. However, as foreboding as the sparse Arctic may seem, some truly remarkable species thrive here... This strange-looking type is called Brinewing. With its stocky shape and beak-shaped mouth, it gives the impression of an ineffective herbivore.

But Brinewing is a powerful predator. To hunt, it unleashes a rapid torrent of a supercooled saline solution that freezes in water and can encase its prey in ice. An exploration suggests that Brinewing uses a highly specialized bladder to produce this supercooled brine from the surrounding salt water. As unusual an adaptation as this may seem, terrestrial archerfish can shoot down insects using jets of water fired from their specialized mouths... and they are remarkably accurate. Other dispersed Arctic species have very different survival strategies. Like the enormous Titan Holefish, a slow-moving herbivore with a strange hole in the center of its body.

The titan holefish is a relative of the tiny guppy-sized tropical holefish, and is much larger than its cousin, in fact you can swim through the hole in its center. But what is the purpose of this hole? A scan suggests that the gel-like interior is lined with hundreds of eggs, but curiously, their DNA does not match that of the Holefish... The mystery of the eggs is revealed when I spot a small life form swimming alongside the Holefish. . Soon, many others join in, swarming like a colony of bees around a hive. These are symbionts, small predators that have evolved to make their nests inside the hole of the titan hole fish and, in turn, defend them at all costs and even provide them with food.

This highly cooperative lifestyle is an example of a mutualistic partnership, one of the few on Planet 4546 B. As a result, the Titan Holefish has evolved to be remarkably unintelligent: it swims forward on impulse, fully trusting the complex ecosystem it supports. supports all your needs. . Just beyond the scattered Arctic, bare sand gives way to abundant Arctic kelp forest. Here, Creepvine plants sway in the polar current, shedding light into the depths with their bioluminescent seeds. These Creepvine plants are close relatives of the green variety that grows in the warm waters of the tropics, although the chemical composition of polar waters has turned them a pale yellow.

Among the leaves, familiar fish like the boomerang flutter among the leaves... …And some very unknown fish also swim here. These extremely strange life forms are called spinner fish and have perhaps the most peculiar swimming method ever conceived. Using three pairs of siphons on the side of its body, Spinner Fish moves forward like living waterwheels. At first glance, its strange body is somewhat reminiscent of the larval form of the sunfish. But ultimately, the Spinner Fish is in a class of its own. Speaking of unique, I soon see an incredible way of life. I'm about to scan it when it swims over and snatches the scanner out of my hands.

Frustrated, I chase after it and find the creature looking back and waving the stolen scanner around to taunt me. Luckily I can cut it out and get my tool back. Upon finishing the scan, I discover that this creature may be annoying, but it is truly remarkable, with a developed brain and finger-like appendages for manipulating objects. It's called Sea Monkey, a nickname it shares with the Earth's brine. However, unlike those Sea Monkeys, the Sea Monkey from Planet 4546 B appears as intelligent as a real primate, meaning it is the most intelligent life form I have encountered in sector zero.

But given time, the Sea Monkeys could have an incredible future trajectory. I just hope they evolve to be less annoying... Once the kelp forest is well mapped out, it's time to regroup on the surface. However, as I poke my head above the water, I discover that the shallows are engulfed in a dangerous polar storm. Looking around, I realize that the Pengwing flock from earlier might be in grave danger. However, upon reaching their ice float, I find that the Pengwings don't care about the weather, they simply huddle together for warmth and wait out the rain. Indeed, Pengwings are intriguing creatures.

Fortunately, as the sun returns, it occurs to me that I still have a lot to learn about the dynamics of the Pengwing flock, but I don't want to disturb them with my presence. It's time for some innovation. I have devised an alternative, less conspicuous method of observation. This machine is my Spy Pengling and hopefully it will be able to keep an eye on the Pengwing flock with its hidden cameras as I continue my expedition through Sector Zero. I'm not sure if the Pengwings will be fooled into accepting this robot as one of their own... but the only way to find out is to try it.

As discreetly as I can, I deploy the robot. Taking control via an axillary remote, I steer the Spy Pengling toward the middle of the flock. It's not… it's not a perfect costume. But the Pengwings don't seem particularly bothered by their presence. Although this robot is unlikely to fool them, it does not seem to alter their natural behavior. I will leave the flock under his watchful eye and venture into regions unknown... Even further out to sea, the mysterious Lilypad Islands float in the water, seemingly by miraculous means. In fact, these floating chunks of rock are supported by giant water lilies: a huge type of plant that defines this ecosystem.

Giant water lilies are so large that it is possible to stand on their leafy crowns without fear of sinking. But it's the strange life that swims in the shadows of the water lilies that makes this region truly unique... Take, for example, the hilariously named Noot Fish. With its colorful markings and innocent beak-like snout, the Noot fish can easily pass for a herbivore. But any fish that makes that mistake is soon swallowed whole. The beak of the Noot fish is actually an elastic and extendable lip, lined with spike-like teeth that it uses to wrap around its prey.

This type of extendable mouth looks a bit like that of the Sarcastic Fringehead of the Pacific Ocean. It is best to be attentive. But there are predators here larger than the Noot fish. The brute shark is an aggressive predator that roams the depths with its ghostly white eyes. With huge fangs and a huge bony jaw, they feed on almost anything they catch. Like many land sharks, they prefer to attack by ambushing from above or below. The only good news is that, while deadly, brute sharks are not particularly fast. Still, if I don't keep my distance, it could be on the menu...

Closer to the surface, I see a remarkably colorful life form. Swimming closer, the edges of my vision blur and I feel a little dizzy. Hey. Has the sky always been that color? Everything feels…floating for a while. Over time, the effect wears off and, with a clear head, I understand what just happened. That life form, known as Lily Paddler, has the unique ability to disorient potential attackers with the fascinating patterns of its colorful appendages. It's an impressive and vital defense for a creature like Lily Paddler, who is otherwise quite vulnerable. I just wish my head didn't hurt.

A shadow passes overhead. Right above me, a whale-sized leviathan opens its mouth to a tremendous size and swallowsan entire school of fish in one gulp. This is a luminous whale and while it is very effective at feeding on small fish, it is fortunately quite gentle. At almost 100 feet, or 30 meters long, they are the first Leviathan-class organism I have encountered in Sector Zero, and a very intelligent one. A scan of glow whales indicates that they possess many organs that are capable of bioluminescence, especially around the corners of their eyes and the tips of their horns. Careful not to scare him, I pass a glow whale under his eye, causing a slight glow.

It is difficult to interpret whether this is a random response or an attempt to send a message. In any case, Glow Whale is happy with my presence. As I watch him reunite with her capsule, I wish I could stay with this mirror life form longer. But before the sun sets, there is one last region I need to map... Beneath the layers of snow and ice, there are telltale signs that a permanent landmass constitutes a part of Sector Zero. Land is so scarce on this oceanic planet that it's impossible to guess what kind of life forms might live further inland.

We'll have to see for ourselves. Passing through a narrow canyon, I find strange hybrids of plants and animals that seem to grow on the walls. These are Thermal Lilies, organisms that spend most of their time following the Sun and absorbing its energy, but that also spin to follow my movement as I pass by. A scan suggests that they are not dangerous, and thanks to the thermal radiation they have absorbed, they are actually a welcome source of heat in the frigid interior of Sector Zero. Still, it's disturbing the way they follow me... Beyond the canyon, a snowy landscape awaits me too vast to traverse on foot.

Luckily I have an alternative method of transportation. It is a Snowfox, a hovercraft designed for land expeditions. As I approach the arctic terrain, I find it has a bit of an effect. At these speeds, you should be able to plot this region quite effectively. Shortly after, I see a furry creature in the distance. The question is, is it friendly? …Unfriendly. Putting the Snowfox into reverse, I discover that the creature is chasing it at an alarming speed. After several near misses, I retreat to a safe distance. That quadrupedal predator was a Snow Stalker, and although it almost sank its claws into me, I can't help but be excited by the discovery of a land animal on planet 4546B!

With its white fur and imposing bulk, the Snow Stalker has converged on a body plan similar to that of terrestrial polar bears. I'm curious about the lineage of such a way of life. A brief analysis reveals that the Snow Stalker is actually a distant relative of the fully aquatic Stalker I found in the tropical region. While these two species diverged long ago, there are still some telltale signs of their relationship in the shape of their head and spines. A fascinating genetic ancestry. Speaking of which, a short distance away from the Snow Stalker, I see what appears to be his pup playing in the snow.

At just a fraction of the size of his father, this baby Snow Stalker is much less aggressive than his father. Well, mostly... Moving forward, I come to a sheet of ice marked by towering, irregular ice formations. This region is known as the Arctic Spiers and is home to a giant... A huge head emerges from beneath the ice. Seconds later, a huge serpentine leviathan rises into the air and nearly kills me with a blow from its enormous horn. This terror of the frozen plains is an ice worm. At over three hundred feet, or 90 meters, it is almost twice the length of a Reaper Leviathan and by far the largest creature I have seen in Sector Zero.

Its glowing horn is superheated by an exothermic chemical reaction, allowing it to melt the ice on which its prey is standing. It's time to make a quick exit. As I speed away on my Snowfox, I see the Snowstalker and his pup from earlier fleeing beside me. We barely reached a safe place. With creatures like the ice worm around, I think I might postpone the field work until tomorrow. As the sun sets, I check in and discover that my Spy Pengling has become a true member of the flock and has done an excellent job keeping an eye on his feathered companions.

Together, my pending robot and I sat and watched the Sector Zero sunset. And with the night comes a final surprise. The sky is illuminated by a dazzling aurora similar to the northern lights in Earth's northernmost latitudes. On our planet, these "aurora borealis" are the result of disturbances in the magnetosphere caused by the solar wind, and we can theorize that they have the same origin on planet 4546B. It is a beautiful and imposing display that can make one feel a little isolated in the universe. But with my Spy Pengling by my side, I don't really feel alone.

A transmission interrupts my thoughts. It seems like I'm picking up a mysterious communication... but from where? And who or what sends it? The mysterious transmission emanates from the murky waters of a region known as Deep Twisty Bridges. Plunging into these alien depths, the only light comes from the bioluminescent coral bridges that spiral across this cavernous abyss. The darkness of the deep has transformed all life that swims in darkness. Like pale ghosts, the skeletal spinefish lurk in the depths. A subspecies of the ringfish, the spinefish, has become almost translucent and has rib-like markings that give it a deadly appearance.

The phenomenon of certain deep-sea fish becoming transparent is also present in Earth's oceans, particularly in the Barreleye fish, an animal that has a head made of translucent tissue that allows it to look up and detect its prey. preferred. Truth be told, the Barreleye fish is an animal that would seem to be at home in the oceans of Planet 4546B. But the thornfish is not a carnivore, so despite its disturbing appearance, it poses no real danger. But there are real dangers here. A huge predator swims, like a torpedo, between the bridges. With unexpected speed, it rushes in and tries to swallow me whole, a fate I can barely avoid by opening its jaws.

The predator continues to chase me, but I escape by swimming into a crevice it can't reach. That terror of the abyss was a squid, a very aggressive species of fauna that is the top predator in this region. Analysis suggests that its terrifying burst of speed comes from two vents on either side of its body, which provide jet propulsion. Through this adaptation, the Squidshark, as its name suggests, combines the most formidable aspects of deep-sea squid and macropredator shark species. The result is a deadly amalgam that I will have to keep a long distance from if I ever want to find the source of the transmission.

Near the bottom of the ocean, a curious undulating plant catches my attention. Swimming out for a closer look, the life form lashes out with a long tendril and draws me into a mouth-like opening. After a few frantic strikes, the creature releases its tentacle and swims out of reach. That was a Spikey Trap, which is actually not a plant at all, but a very unusual form of animal. This carnivorous life form blends into the terrain, camouflaging itself among vegetation and capturing fish (and unsuspecting explorers) with its adhesive tendrils when they swim too close. And despite their lack of mobility, this strategy seems very effective.

In Deep Twisty Bridges, one must always be alert. Elsewhere on the sea floor, I discover a strange glowing device near the source of the signal. This ruined fragment matches the strange structures present in the tropics, which belonged to a group of alien architects. I assumed all the architects were dead... but with the sign beckoning me forward, I wonder if I was wrong... Finally, I arrive at a mysterious underwater facility. As I navigate the hallways, a mysterious voice urges me to hurry. Entering a central chamber, I find that the signal and voice are coming from this cube-shaped computer.

The voice turns out to be that of an architect who, thousands of years earlier, had stored his consciousness inside the computer. Speaking through the cube, the architect explains that he was a scientist like me and that now I am probably the last of his kind. Wanting to help a fellow researcher, I offer to transfer the lone consciousness to my field computer and take it with me on my expedition. The Architect accepts and warns me to... prepare for the transfer? A little late, I realize that something might have been lost in translation... Waking up with a slight headache, I can hear the Architect's voice quite clearly... and discover that this is because it was downloaded directly into my brain.

It was a sincere mistake, since architects do not recognize a boundary between technology and the body. While this is an intriguing revelation about architect biology, it means I now have an unexpected mental roommate... Returning to the shallows, we formulate a plan. We will use our combined knowledge to continue mapping the biology of life in Sector Zero, but along the way we will gather the material needed to craft a body into which my new friend can transfer. He tells me his designation is A L hyphen A N… so I'll call him Alan. Continuing where Alan's research left off, we venture into the vast expanse of the Western Arctic.

Here, large icebergs float above a seemingly bottomless region of sea, creating a profound sense of scale. And among these icebergs swim rarities to be discovered. Sliding through the blue, it is a difficult animal to unravel. With two sets of wing-like fins, it's unclear what kind of life form we're looking at with the naked eye. But this life form is, in fact, an arctic ray, the first of many ray species in Sector Zero. Although its body structure has clearly differentiated itself from terrestrial rays, having four wing structures instead of two, the Arctic ray is a very agile life form...

And it has to be, if it wants to avoid the main predator of the Western Arctic. It is a pinacarid, an intelligent and social predator that spends half of its time floating on ice above water. Pinnacharids have converged on an ecological niche similar in many ways to terrestrial seals, and are remarkably friendly towards humans, even showing great curiosity when enticed with a tasty piece of fish. Alan's analysis suggests that their fourteen fins make them acrobatic underwater hunters. This unusually high number of fins resembles the anatomy of anomalocarids, a group from Earth's Cambrian period that also possessed multiple fins for locomotion.

As we descend deeper into the waters of the western Arctic, what appears to be a legion of pulsating eyes stares back at us. In fact, it is a colony of Eye Jellies, gelatinous life forms that house a huge hemispherical eye on the top of their bodies. Despite their alarming appearance, these creatures live remarkably passive lives, drifting slowly along with the currents in vast colonies, without paying much attention to other species. Alan warns me that they are capable of releasing a small electric shock if we swim too close, so we'll give the group a wide berth. Above one of the Western Arctic icebergs, we noticed the entrance to a small cave.

Venturing inland, the ice reflected by the afternoon sun resembles the glow of the night sky. And inside this ethereal cave, a strange egg appears stranded on the cave wall. It is not a species that Alan recognizes and appears to be about to be born. We carry the egg to the warmth of the shallow water, after a while this creature emerges. The unusual hatchling turns out to be a Trivalve and, like the cuddler fish of the tropics, it is a remarkably friendly and intelligent creature that loves treats. A scan suggests that the body of this naturally curious creature is made of a flexible exoskeleton, and somewhat resembles the shell of a terrestrial Nautilus in its shape.

It's tempting to relax in shallow water with the Trivalve, but Alan reminds me that we still have other areas to plot. The next leg of the journey will be truly dangerous. Luckily, I have a new submersible classification to help me on the journey. It is a Sea Truck, an underwater vehicle that will allow us to descend further than ever into the crushing depths of Sector Zero. At the helm of the Sea Truck, we enter the vast biome of the Thermal Zone. The edge of this region, an area known as Thermal Spiers, is marked by a forest of hydrothermal vents.

These chimney-like structures form from dissolved minerals pushed up from the planet's crust and are home to all kinds of extraordinary life. Sliding between the vents is a brightly colored featherfish. Defined by their unusual crescent-shaped fin structure, featherfish are one of the most elegant herbivores in Sector Zero. A highly successful species, in some regions they gather in schools of thousands. We are admiring one of those schools, when an intimidating creature walks by. This predatorarmored and fierce looking is a Cryptosuchus and is covered in sharp spines. With a savage snap, it approaches... and then retreats just as quickly.

It turns out that the opposite Cryptosuchus is a species in which its bark is actually worse than its bite. While it looks fearsome, a scan suggests its bladed frame is adapted to aid in heat absorption between thermal vents. And so, this false tyrant rows away, to try to scare away something a little smaller... Much deeper into the Thermal Zone, the dark blue of a biome known as Tree Spiers beckons. These waters are illuminated by bioluminescent flora that grows on the sides of tree-like hydrothermal vents. In this distinctive region, the equally distinctive ungula discus fish. Its flat, semi-transparent body is very unusual and appears to contain strange green organs.

A study of discus fish reveals that this green color comes from symbiotic algae-like organisms that live within specialized body cavities that provide food for the discus fish. Oddly enough, Earth's emerald sea slugs also perform photosynthesis using algae that grow inside their bodies. Since there isn't much sunlight here in the depths for plant growth, the discus fish likely spends part of its life cycle in a brighter region of Sector Zero. In another part of the Thermal Zone, we can see a teardrop-shaped arrow ray. This species of stingray has an elongated body and a rather triangular head, which it can tilt to perform unpredictable maneuvers.

The ends of the Arrow Ray's fins grow sharp, claw-like spikes that deter attackers who manage to reach it, meaning the Arrow Ray is certainly not defenseless. A huge life form passes in front of our submarine. Without warning, it screeches and grabs the windshield with its front jaws, pulling us down its throat. Revving the engine, I can barely free myself from the death grip. That leviathan-class organism was a chelicerate, a brute that grows over 130 feet or 40 meters long. Its body is covered by a thick, segmented exoskeleton that grows in overlapping plates, which can offer protection against atmospheric pressure.

Because chelicerates are so aggressive and life-threatening, they are a difficult species to study up close. Fascinating as they are, we both hope we don't encounter more of them. At the bottom of the sea, an indescribably massive life form awaits. This is a Ventgarden, a stationary leviathan that anchors above the thermal hydrovents and consumes 100% of the nutrients released by the vents. At over 360 feet or 110 meters, Ventgarden is by far the largest Leviathan in Sector Zero. The only things in Earth's oceans that look like Ventgardens are certain types of siphonophores: soft-bodied entities that, like Ventgardens, are also technically colonies of smaller organisms working together.

But the most incredible thing about Ventgarden is the internal ecosystem of plants it houses within its hollow, bell-shaped center. And surprisingly, a scan indicates that it would be safe to enter this environment ourselves. Exiting the submarine, we tentatively swim towards the light and eventually emerge within the microcosm of Ventgarden. This mini ecosystem supports aquatic flora on branching platforms which in turn help absorb some of the heavy metals emitted from the lower vents. Exploring the hidden biosphere of Ventgarden is a downright magical experience... But the unknown still beckons. Going deeper into the abyss than ever before, we have reached the edge of the habitable region for most fauna.

Surrounded by total darkness, Alan begins to worry that we have strayed too far. And he seems to be right. A massive Chelicerate emerges from the darkness, almost twice the size of the one in Tree Spiers. This pale mutation is called Void Chelicerate and it is not the only one. We have come across a herd. It's time to return as quickly as we can. I don't think any of us plan to visit this area again anytime soon. Returning to the security of the research base, with Alan's help, I have improved our station a bit. It turns out that having an alien scientist downloaded into your brain can be very useful.

And although Alan still doesn't understand the purpose of basic things like music, or why I start every morning with coffee, together we have successfully mapped much of Sector Zero. However, a deep scan tells us that there is a strange signature coming from a large ice cave that we have not yet mapped... The cave is deep inside Sector Zero, on the other side of the frigid tundra. Finally, we entered the cavern and discovered a huge frozen creature locked in the wall of a cave. This leviathan-class organism has been buried here for thousands of years, as Alan remembers encountering someone of his species when he was a researcher here long ago.

Since this species is expected to be already extinct, the only way to study it is to drill into the ice. By taking a DNA sample from the creature's foot, I can determine that the life form was quadrupedal and spent at least some of its time on land, unusual for planet 4546B. Perhaps this frozen Leviathan suggests an era in the distant past where the land was more plentiful and great titans like this roamed it. In any case, I'm glad this particular specimen is long dead. Believe. Finally, we now have all the materials needed to make Alan's new body.

The only problem is that the Architect Facility that can create such a compatible ship is located in a region known as Crystal Caves. These caverns are the deepest biome of all and the final frontier of planet 4546B. And since refractive crystals mean that any scan of the region is fragmented, there's no telling what else is down there... Sailing through the purple abyss, this environment has a strange beauty. And equally strange life forms navigate its depths. The Triops is a small life form that spends much of its time hiding from predators in the surrounding terrain. However, Triops stand out biologically thanks to their distinctive three-eyed ocular system.

In nature, a life form that develops three distinct eyes is not particularly common... but it is not entirely unheard of. Artemia is a genus of aquatic crustaceans that have two eyes mounted on flexible stems and a third stationary eye located in the center of their head. So the tiny Triops is in good company. Deeper into the planet's crust, we reach the Maker's Caves: a secondary layer of the Crystal Caves, where a high concentration of the element beryllium caused the formation of striking red crystals. To confront this extreme geochemical environment, I donned the Prawn Suit: a deep-sea mechanical walker that kept me safe in the final stages of my journey through the tropics.

Stomping on the ocean floor, I see a small crustacean nearby. Given his diminutive stature, I'm not particularly worried, until he lunges for my shrimp suit. This is a Rock Puncher, a pint-sized predator that is nonetheless a heavy hitter. Their hardened chitin claws can move at near the speed of sound to break rocks and bones alike. In many ways, the Rock Puncher is similar to the precocious mantis shrimp. These unsuspecting creatures possess spring-loaded biological hammer-clubs that can hit their prey faster than the speed of a bullet, giving the mantis shrimp the ability to truly punch above its weight class.

And Rock Puncher is no different. It's time to de-escalate the situation... by moving somewhere else. We are now very close to the Manufacturing facility, when a thunderous roar shakes the cavern. A huge Leviathan grabs my shrimp suit and pulls me into a glowing gorge. After hitting it with the arms of my shrimp suit, the nightmare snake temporarily drops me. Backing into a narrow gap, the leviathan can't seem to follow. We're safe... for now. That was a Shadow Leviathan, which at almost 200 feet, or 60 meters, is the most dangerous predator in Sector Zero. Its black, elongated body gives this monster the appearance of a giant eel.

Analysis suggests that its bioluminescent digestive tract glows due to light-seeking phytoplankton that attracts unsuspecting fish, and also secretes a highly acidic compound. I am lucky to have been able to escape such a terrifying way of life unscathed. Or have we done it? Looking up, I notice that my shrimp suit is leaking from his fight with Shadow Leviathan. Our only hope now is to reach the Manufacturing facility before the Shadow finds me again. But with the familiar green glow of Architect technology ahead, we've finally reached the final destination. Upon entering, I find a facility very similar to the one where I first discovered Alan.

By placing the materials we have gathered, the installation begins the manufacturing process. Activating the ending sequence, Alan and I watch the ship being built. This new body is made up of the DNA of 27 different species and also various inorganic materials, so it should be a big improvement. At last, Alan's body is complete. After so much effort, it is almost surreal to reach this point. I think about telling my friend that he looks a bit like a bright purple centaur... but I decide that would probably just confuse him. Now that Alan is out of my mind and on his new ship, he doesn't need my help to continue his investigation.

We both return to the surface and Alan informs me that he will return to his home planet through the Warp Gate, to see if there are any other Architects still alive. It's a bit of a bittersweet feeling realizing that this is goodbye. Working with another researcher (particularly an extraterrestrial one) has been a special privilege. Once again, alone on Planet 4546B, I consider all that I have seen on this wonderful planet. From harrowing dangers to unexpected allies, it has been an extraordinary journey. But now, finally, the time has come for me to leave too. Who knows what else could be waiting for us among the stars...?

If you enjoyed discovering the creatures of Subnautica, please follow and support creature designer Alex Ries using the links below. And as always, thanks for watching. If you enjoyed this post, please support us by liking, subscribing, and hitting the notification icon to stay up to date on all things Curious. See you in the next video.