- - Davy Jones
Abzu is an artificial satellite world in orbit of the Virgo Birch Planet. The star-sized world is covered in a vast ocean dozens of kilometers deep that spreads across almost 100% of the its surface. Under this ocean lies a transparent barrier encloses the world's neutron star core, the polar jets of which emerge from immense maelstroms of water and jet into space.
The powerful magnetic field of the neutron star creates unusual effects at the world's surface, but other than these, the oceans are reasonably habitable and house a myriad of alien lifeforms.
Abzu orbits the Virgo Birch Planet at a distance of 14.9 light-years, giving it an orbital period of 747 Earth years. The world's rotation takes 68 hours. At this distance, the Birch Planet takes up 2.5 degrees of the sky, 5x as much as the Moon on Earth.
Relativistic Effects Edit
Due to the gargantuan mass of the Birch Planet, even at it's immense distance, Abzu still orbits at an extremely fast speed of 38 million m s-1. This means the world is travelling at 12.5% the speed of light, which introduces special relativistic effects.
First, time on the satellite runs 1% slower than in the rest of the universe, for every year that passes for an external observer, three fewer days pass on Abzu.
Additionally, electromagnetic radiation approaching the world is increased in energy by 1%. This means a 98 MHz radio dignal will be increased in frequency by about 1 MHz, which can make radio communication to and from the satellite difficult if this isn't accounted for.
As Abzu has a mass on par with the average star, a few planet-sized satellites of its own may have naturally formed around it. These are unnamed and unknown but probably don't number more than 10.
There would also be countless millions of smaller objects in orbit, many of which fall within a region that has been identified called the Shoal Belt, analogous to a planetary ring but on the scale of an asteroid belt.
The world is composed of a solid crust that surrounds an empty void with the neutron star at its center. On top of the crust sits an ocean of water 79 kilometers deep. The world has a total radius of 4.9 million km (7 Solar radii), giving it 14,000x times the ocean area of Earth, and meaning 1,400 average stars could fit inside it.
The Ocean on Abzu is about 79 km deep on average, giving the bottom of the ocean a pressure of 623 MPa, or 6,100 atmospheres. The ocean itself is salty with NaCl and many other dissolved species like CO2 and O2. Light can only penetrate a small fraction of the ocean and most of it is in complete darkness. In total, Abzu has 24 octillion liters of water on it, 18 million times as much as the Earth.
The core neutron star is surrounded by 4.9 million kilometers of empty space which is encapsulated in a strong partially transparent barrier called the firmament. This barrier remains strong against the immense 6,100 atmosphere of pressure pushing down on it from the water above by use of the same dynamical compression technology used to support that layers of the Birch Planet. The firmament is not very transparent, letting only a small percentage of the light through and seemingly blocking 100% of X-rays. This allows the neutron star to be viewed visibly without the need of additional filters to screen its immense luminosity at such short distances.
Neutron Star Edit
The central neutron star has a mass of 1.4 solar masses and a radius of roughly 10 km. The star spins at about 556 Hz. The neutron star has an extremely strong magnetic field of approximately 100,000 T at it's surface. On the surface of the ocean, this weakens to only 0.21 T at the surface of the ocean, which is still 4,600x stronger than that of the average terrestrial planet. This field's poles aren't quite aligned with the rotational poles of the star, with an angle difference of 0.3 degrees. Therefore the magnetic dipole tends to process very quickly as the star rotates.
Out of the magnetic poles of the star shoot jets of X-ray radiation with a power of about 0.002 Solar luminosity, and charged particles. These emerge though holes in the firmament and then through giant vortices in the poles of the ocean to blast into space. Nuclei of super-heavy elements like flerovium-298 have been observed in these jets which may indicate that the world have some function related to the synthesis of exotic elements. Although, it's design is inefficient for this so it's unlikely this is Abzu's only purpose.
Generally, the Abzu is temperate around the equator with the temperature rising quickly towards the poles due to auroral heating. Rain/storms are common on the surface but not constant.
The atmosphere of Abzu is non-toxic to most forms of carbon-based life and is dense with a pressure of 1.1 atmospheres at sea level. There is however, slightly less oxygen than most planets and almost 3x as much CO2 which can make survival on the surface of the planet by extraterrestrial visitors without aid physiologically taxing, but possible.There is a high percentage of 2.2% neon in the atmosphere. This can become excited by the powerful electric fields induced by the magnetic field during en electrical storm and can emit ultraviolet radiation, which can harm some lifeforms but can be utilised by others.Storms on the planet are frequent but not constant and can result in all kinds of precipitation, these can move quickly however as the lack of landmasses allows for very powerful pole-to-equator winds to build up. Large hurricanes that rage for months over a particular point on the equator are not uncommon.
Electromagnetic Effects Edit
The extreme electromagnetic field of the neutron star has a number of unusual effects on the oceans/atmosphere of the world. The most noticeable is that the field is strong enough to pull objects made of ferromagnetic metals like iron or nickel with strength similar to a commercial bar-magnet, propelling them away from the equator and closer to the north or south pole. However, due to the rapid procession of the poles because of the star's rotation, the direction of this tug will rapidly change. This violently shakes and rattles objects made of such metals, which can damage or destroy structures/machines made out of them.
The changing magnetic field will induce electric currents in the salty water of the oceans that run laterally around the globe and get stronger towards the poles. These can interfere or even destroy electrical equipment but have been harnessed by some lifeforms on the world
Similarly, the magnetic field will alter the weather in electrical storms, producing ball lightning that moves through the sky at supersonic speeds from East to West. This effect can make lightning difficult to predict in terms of power and strike location
One of the most noticeable effects of the strong magnetic field are the Auroras of the world, which are thousands of times stronger than the average terrestrial planet. As the world does not orbit a star, these auroras are the sole source of illumination and extend all the way to the equator, becoming blindingly bright at the poles.
Abzu does have quite extreme tidal bulges due to the utter mass of the Birch Planet it orbits. However, as there is almost no land on the world, and the days are long, these effects are not easy to notice.
Due to a lack of large continents, Abzu doesn't really have any surface geography worth considering. The surface however, can be divided up into different latitudinal regions based on how much light each recieves from the aurora. The ocean itself can also be divided into different depth zones based on how much light is able to penetrate a given depth.
Dial Zones Edit
As mentioned, the different latitudes of Abzu are divided into specific zones depending on the about of light revived from the powerful auroras of the world. The light gets brighter towards the poles.
The Crepuscudial Zone, or, Twilight Tropics occurs near the equator where the light is always dim. Here it is cold enough that icebergs sometimes will form although there is no permanent ice. At this zone, the elctric currents in the ocean and electrical storms are the weakest.
The Eudial Zone, or, Temperate Zone is the largest zone on the planet and has light comparable to normal daylight on other planets. The brightness will of course vary however from dimmer near the equator to lighter nearer the poles.
The Lucidial Zone, or, Radiant Arctic is a zone where the light becomes very bright and the electromagnetic effects of the poles become quite strong. Here, electrical currents are strong enough to electrolyse water and salts given the right substrate and ball lightning will stream our of electrical storms at supersonic speeds. The oceans are quite warm in this zone
The Oblitotidal Zone, or, Blinding Poles are the brightest region on the planet with the auroras making it difficult to see anything except blinding white light. sight is not a very useful sense in this zone and the high temperatures make it hostile to all but the most extremophilic life. The zone is capped with the Polar Maelstroms, a huge whirlpool at each pole out of which spews the powerful X-ray beams of the neutron star.
Pelagic Zones Edit
The pelagic zones of Abzu are defined by how much light is able to reach to their depth. At shallower depths, the boundaries of these zones will therefore greatly depend on the dial zone as well as the light intensity actually entering the water will vary with latitude too.
The first pelagic zone, the Epipelagic is not pictured here because it only spans the shallowest 200 m of the ocean on average. This zone has good lighting, allowing photosynthesizing organisms to grow and organisms that rely on sight to navigate their environment. The Mesopelagic Zone (also called the Twilight Zone) spans the next 1,800 m and also has light, although only twilight levels of it. Here, organisms that dwell in an open-ocean habitat live and can use sight, but photosynthesis here is rare.
The Bathypelgic Zone receives no light from above so photosynthesis cannot be used here. Ecosystems at this depth rely on detritus falling down from higher zones and other more exotic means of energy generation such as magneto- and electrosynthesis.
The Abyssopelagic Zone is very similar to the Bathypelagic but recieves even less light and has even less life. The Hadopelagic Zone is similar to the Bathypelagic and Abyssopelagic, extending down to a depth of 11 km. However, the increasing pressure of ≈850 atmospheres at this depth starts to become a serious concern for organisms and craft.
The Inanopelagic zone is by far the largest zone in the oceans of Abzu and is virtually devoid of life due to the low temperatures, lack of solid substrate, and lack of light. The Harlopelagic Zone however does harbor some lifeforms. This zone is so high in pressure that pressure fluctuations can produce impermanent but lasting underwater icebergs of ice(IV). These are denser than water so will not float up to the surface and can act as a substrate for magetosynthetic communities to live on.
Finally, the R'lyepelagic Zone is the deepest on the world, extending all the way down to the firmament. This zone can also form ice(IV)bergs but is mainly characterized by the X-ray radiation that permeates it. This mostly has rendered the R'lyepelagic sterile of organisms.
Life on Abzu is organised by the same taxonomic ranking system as much of life in the rest of the known universe. One unique feature however is the presence of a taxonomic rank above Domain, Dynasty. On Abzu, life arose completely independently two separate times, the resulting biospheres of which remain isolated from each other. Each seperate lineage is said to be a different Dynasty. The Vadum Dynasty is the most common and widely spread, organisms from it colonizing the five highest pelagic zones and all dial zones on the planet. The Profundum Dynasty however, originated in and is mostly confined to the Harlopelgic Zone. Each of these Dynasties have their own domains, kingdoms, and lower taxa. The only place on the world where organisms from both these dynasties coexist is in the scavengers and decomposers of the R'lyepelagic Zone.
Between dynasties, analogous clades may exist where different groups of organisms may have independently evolved similar structures and taken up similar roles in their environments. Although these clades aren't evolutionarily related, many statements said about one will also apply to the other.
Due to their separate origins, Vadal and Profundal organisms have fundamentally different biochemistry from each other. However, as both arose on the same planet, both dynasties use similar chemical building blocks, just in different ways.
Nucleic Acids Edit
The genetic information of both dynasties is stored in a molecule called deoxylyxonucelic acid (DLNA). This molecule is similar to DNA except each monomer of molecular chain contains a 2-deoxy-D-lyxofuranose sugar instead of a 2-deoxy-D-ribose sugar.
The letters used in this information storage molecule are also different to DNA, employing the bases Uracil, Thymine, Pescadine, Adenine, and Xanthine. Each of these bases will only pair with its canonical partner in the DLNA double-helix. Here however, is the first different between the dynasties. While both form P-X pairs, A is only ever paired with U in the Vadum dynasty, and T in the Profundum Dynasty. U and T are similar but this is enough of a change to make the genetic codes of both clades definitely distinct and separated from each other.
Amino Acids Edit
Both dynasties use amino acids build their proteins. However, each uses a different range of proteins and different amino acid configurations. Amino acids come in two forms due to their chiral alpha-C that are non-superimposable mirror images of each other. i.e. there is no way one configuration can be rotated in space to overlap perfectly with the other. This becomes especially relevant in reaction where molecular shape is important such as when a molecule much fit into the precisely shaped catalytic pocket of an enzyme. The Vadum Dynasty uses D-amino acids while the Profundum Dynasty uses L-amino acids. This means the protein of each dynasty is indigestible and often toxic to the other, except for in a few clades of R'lyepelagic microbes.
The way the genetic code is translated into each amino acid is also different between the dynasties. While both use blocks of three nucleic bases called codons to correspond to each amino acid, the specific combination of letters in these codons is different for each.
Due to the enormous size of Abzu, the world has orders of magnitudes more biodiversity than the average terrestrial planet or waterworld. Below are a few examples of the more notable or interesting examples.
The Temperate Zone is the largest and least hostile shallow-water habitat on Abzu. This region receives appreciable levels of light from the powerful auroras of the world, allowing photosynthesis to occur in organisms that live near the surface. This is the basal source of energy for all temperate ecosystems.A cornerstone of temperate ecologies are creatures called arichimoral, which are small tentacled polyps that form large, hard structures call auxilia out of limestone to protect themselves. However, as the seafloor of Abzu is dozens of kilometers below the surface everywhere on the planet, these organisms have no surface to adhere to. Archimoral solves this problem by incorporating tiny bubbles of CO2 gas into the auxilite that composes their auxilium. These bubbles are of a carefully controlled size and number such that they render the auzilite the same average density as water, rendering the hard, stone-like structure of the archimoral neutrally buoyant and able to float around.
Archimorals are filter-feeders, eating food particles in the water. However, many species have developed a symbiotic relationship with photosynthetic algae-like organisms to supplement their food production using the energy of the sun. This gives different archimoral species distinctive, bright colors.
Although an individual archimoral may independently grow free-floating in the water, they will often clump together to form reefs. These structures, although slow-growing can become massive island-sized rafts of solid material that support a myriad of other diverse organisms, much like the coral reefs of shallower oceans on other worlds. These are the only place that other sedentary organisms like static sponges, anemonoids, or stationary shelled-creatures can live.
Algoid organisms that use the energy of light to convert CO2 and water into energy are common in this part of the ocean and form the base of many ecosystems. Both red and green algae exist and use different wavelengths of auroral light for their energy needs. As the color of the auroras changes slightyly as latitiude increases, the color of the algae found will also shift.
One interesting family of creatures in the temperate zone are the Keestrae. These are eusocial mollusk-like organisms that build cooperative super-shell colonies called cochili inhabited by hundreds of individuals. A cochilus is a many chambered agregate of the shells of many smaller colony members that fuse together to form a larger structure. The caste of worker that build this shell are called the fortifiers. These workers have long extended bodies that secrete shell material over a much longer range than other castes, allowing one individual to make much more shell and thus colony wall. Fortifiers build themselves into the walls where they either have to be fed by other workers to keep building more wall, or are left to die if their job is complete.
Workers come in several other casts with distinct jobs. General workers have slim shells to allow easy movement through the chambers of the colony itself, soldiers have large defensive shells and enlarged serated radulae, spending time outside the colony, and foragers have defensive shells and special pouches near the mouth for carrying algae. Doormen have large flat shells that fit over the circular entrances of tunnels that can be moved out of the way by the doorman from an alcove in the wall, opening/closing the tunnel. Coachmean are workers with their shells fused to the base of the whole colony on the underside, allowing them to slowly slide the colony to relocate if food becomes scarce or a threat is detected.
Stratum is an order of creatures that take the form of large blankets of dense jelly. These blankets are muscular and so the strata are able to contort and twist in the water to pick up food particles on the tentacles that trail from the edges, ferrying it to the center of the knot where they are able to be digested. To migrate, these creatures are able to lay themselves flat like a sail and be pushed around the by strong ocean currents.
The order Vollae are arthropoids, often large, that are able to secrete an extremely durable and sticky mucus which they are able to use their eight shelled legs to spin into a variety of nets, webs and lattices they can use to ensnare prey that happens to be carried past by the ocean currents. Some spcies however will set their trap up across a natural object that can act as bait, such as a the entrance to a popular cleaning spot.
The most challenging environmental condition of the deep seas of Abzu is the fact that there is no sunlight so photosynthesis is impossible. The depth of this habitat can vary by latitude depending on how much light is available but eventually becomes uniform deep enough. This means that organisms either have to rely on the marine snow, the organic detritus that drifts down from higher layers, or on other more exotic methods of energy collection.
Free-floating archimoral reefs are a vitally important to deep sea habitats as they can often be the sole substrate for stationary organisms to live on for many kilometers in all directions and create concentrated, biodiverse ecologies. Due to the lack of like in these habitats however, these creatures are filter-feeders and are not brightly colored, ranging usually from red to brown. Reefs shelter 98% of the deep ocean biodiversity.
The gas bubbles of the archimoral structure can must form at the same pressure as the water around them and so the deeper a species lives, the denser its gas bubbles are. This means to remain buoyant, a larger and larger percentage of the auxilium must be taken up by gas bubbles, meaning that the depth a particular species is found can be determined by analyzing its auxilite structure. As the bubbles are sealed, they won't actually change in pressure after the organism has grown. This means all species are still bouyant at any depth and so can move from the depth where they formed to a different depth, the density of the auxilite remaining the same as as the seawater since the ocean's density does not change. However, by an archimoral moving out of it's home depth, there will be a difference in pressure between the bubbles and the water which can cause the auxilite to break and the creature to die. The compressive strength of limestone places the range of movement at never more than 1200 m in either direction.Another hard limit on how deep a species of archimoral can grow is its so-called crumble limit. This is the minimum percentage of the auxilite that must be limestone to stop the mineral from becoming to weak and crumbling. This limit sits at about 60% limestone by volume, placing the crumble limit for most species at about 5,000 m deep.
A notable exception to this are methanoarchimoral, in the order Subteraceae. These archimorals have a symbiotic relationship with microbes that live in their tissues that feed on a portion of the organsim's food and ferment it into methane. This allows the archimoral to build auxilite with a CO2/methane gas mixture that is less dense, allowing less to be used for the same buoyancy. This puts the 60% crumble limit at a much lower depth of 14,000 m. However, the metabolic strain put on the archimoral by the microbes means that the scarcer food at these much larger depths doesn't allow survival. As a result, methanoarchimoral live alongside other species, and also in a band approximately 500 m below the pure CO2-using species.
One such group of organisms are those that belong to the kingdom Faradae. These organisms harvest the energy of the changing magnetic field of the world to power their cellular processes. A common structural motif in these organisms are loops and rings of vascular tissue. These vessels are capillaries formed by the end-to end fusion of cells called rheocytes with pores linking them. These cells have no nucleii are are nourished by flat cells on the outside of the capillaries called nurse cells because their internal conditions are hostile to many cell processes.
The inside of a rheocyte is extremely salty with Mg2+ and Cl- ions. These ions will experience a force due to the changing magnetic field of Abzu that causes them to circulate back and fourth inside the vascular rings. Protein complexes that surround the pores at the interfaces between rheocytes use the energy of the ions moving through to drive the catalysis of ATP generation through a rotating part of the protein complex. This ATP, through a complex chemical process, is then used to generate carbohydrates that may be used for energy from H2O and CO2 in the sea water, leaving O2 as a byproduct. Rheocytes have very thick cell walls that put a pressure on the membrane of the cell that prevents it from bursting from drawing in too much water by osmosis.
Faradae is a diverse kingdom with many free-floating species an species that have adhered to archimoral reefs. There are also farads that have carved out a nice in brighter shallower waters since they don't compete for light with the photosynthetic flora that live there. Due to their energy generating mechanisms, farads must always face in a particular direction to harvest energy well. This varies with latitude with equatorial species lying flat like a table and those closer to the poles positioning their rings more and more vertically. Adherence to solid structures like reefs helps to ensure this direction remains stable.
The creatures that live in the deep sea live in a world of darkness where coloration and sight find limited use. It is common however for organisms to be able to produce their own light. Another indispensable sense at these dark depth is echolocation/sonar which allows the detection of the size and shape of objects in the dark. This is usually confined to only large, complex creatures.
Toroidia is a phylum of filter-feeding organism found primarily in the deep sea. These simple creatures consist of a hoop-shaped body of jelly with tentacles radiating out from the surface. Flexing contractile tissue in the hoop will cause it to rotate on itself, constantly moving new tentacles through the center like a conveyor belt that creates a gentle jet of water to propel the creature forwards. Some clades in this phylum are predatory and will use venom in their tentacles to parlyse prey so it can be drawn into the center for digestion. It is theorised that these organisms evolved from an ancestor with a primitive, straight digestive tube that grew wider and shorter over time. Many species can also produce their own light
Another phylum of jelly-like organism are those in the phylum Libera. These creature's bodies are composed of flat layers of soft jelly sandwiched between two layers of much stiffer jelly, all joined along one side. The creatures move by opening the resulting folds so that water sits between each layer, and then violently slamming shut, forcing the water out and pushing itself along. The layers themselves are used to absorb nutrients from the water and only after the creature has depleted a place of food will it move a few meters to its next feeding site.
With it's near subzero temperatures, transient underwater icebergs, and powerful oscillating magnetic field, the Harlopelagic Zone is one of the most hostile habitats on the planet. Yet, ecosystms have been found to thrive here. All life in this zone belongs to the Profundum Dynasty, not the Vadum Dynasty life in the shallower oceans belongs to. The Profundum Dynasty interdependently arose at these depths and spread to colonies this yet unexplored niche. The bodies of Vada creatures laden with still living bacteria and parasites do make their way to this depth occasionally, but these living organisms cannot survive here and come established due to the lack of food as the different biomolecular building blocks of the Profunda are indigestible. Profunda are kept isolated to the Harlopelagic by the immense distance and pressure gradient of the Innaopelagic Zone above.
One difference that the Harlopelagic Zone has to deepsea habitats on other planets the complete lack of volcanism. This means that the thermo- and chemosynthetic methods of cells for deriving energy are unavailable and other biological strategies have to be employed. A critical clade of microorganisms to the ecosystems at this depth are the Mangetomicrobia. These microorganisms contain large amounts of a chemical called rozantlia which consists of a carbon-based aromatic skeleton that surrounds a manganese(II) ion. This ion is highly paramagnetic with a magnetic moment of 5.9 BM and thus will respond to the rapidly changing magnetic field of Abzu.
In solution, rozantlia molecules would simple rotate with the field but in magnetomicrobia, dozens of the molecules are held in place in a protein complex called Tesla Pump I (TPI). Because their held static, the force on the Mn2+ ions is transferred through the rozantlia skeleton and into the pump, causing the lobes to rotate. This pumps protons across a membrane, which creates an electrochemical gradient which drives the protons back across the membrane through another enzyme complex that uses the energy of their motion to synthesize ATP. This magnetosynthesis contrasts to the faradosynthetic, magnetism-powered strategies of shallower seas which rely on a current of ions to be induced.
The angular momentum of the TPI can induce a counteracting momentum in the bacterium, which will cancel out the rotation of the pump and prevent energy generation. For this reason, magnetomicrobia will aggregate together, their cell walls merging, to form small colonies a few millimeters across. These clumps are pink due to the color of the manganese in the rozantlia and the individual microbes coordinate to place themselves at such angles that the net angular momentum induced in the colony is zero. This mechanism if energy generation is not found in organisms in shallower zones even though the same magnetic field is still present due to the lack of gene flow between the zones.
Larger, more complex eukaryotic cells have learned to exploit the ability of magnetomicrobia in the same way algae have learned to use photosynthetic bacteria in the shallows. Here, an ancient ancestor of modern magnetomicrobia was engulfed by a eukaryotic cell and entered into a symbiotic relationship inside it. The microbe, now a rozaplast, loses a lot of its independence and makes energy for the cell in exchange for a safe place to exist and easy access to resources. The rozaplast must be solidly anchored at many points to the cytoskeleton of the cell to prevent it from rotating within it. Cells with the ability to generate energy in this way are called Teslae, an entire kingdom of life in this zone.Some teslae have evolved a strategy where they will group up into larger living structures called macroteslae or, Tesloids. This helps fight against the ever-present Darwinian pressure of preventing counter-rotation of the cells and also allows different cells in the structures to specialise to energy-producing, defensive, or structural roles as nutrients can be shared between cells. Tesloids form the base of the Harlopelagic ecosystems for all organisms unable to filter-feed on magnemicrobia and teslae. Tesloids are in effect, magnetic flora.
Sight is an almost unheard of sense in the Harlopelagic Zone. This is because in other deep sea habitats, organisms with eyes evolved from ancestors that once lived in the lighted shallows, with their eyes simply becoming large and more sensitive as they migrated to deeper, darker depths along with developing light-production abilities. Because the creatures that originated in the Harlopelagic have been in complete darkness since their genesis, the ability to evolve eyes and the light-producing capabilities needed to see anything has too high an evolutionary barrier to have occurred yet.
A very common sense possessed by Harlopelagic creatures is magnetoperception. This is accomplished by sensory organs called Weber Globes which are hemispheres studded with thousands of tiny pores filled with an electrically conductive jelly. When magnetic field nearby a magnetoperceptive creature is slightly different from the background level, the voltage inside these gel-filled pores changes and sensory the cilia of receptor cells at the base are deflected, opening ion channels that create a nerve signal. This can detect the presence of other organisms with magnetic components such as tesloids and so is crucial for some teslivorous creatures to finding their food.
Construction and Biogenesis Edit
It is unknown when exactly Abzu was built but a few guidelines can be placed by analyzing the history of the objects near it. The Virgo Birch Planet is only 600 million years old, meaning that if Abzu was built as a satellite simultaneous to the planet's construction, it would be around that age. From observations of other planets, this makes it unlikely that life arose naturally by abiogenesis completely independently as it usually takes multiple billions of years on other worlds for multicellular life to arise from cells. It could be that the Virgonians influenced the development of like to become more complex faster, or simply that Abzu is an outlier where unique conditions on the world, like the selection pressure towards cellular aggregation for Teslae, made complexity evolve sooner than normal. The other possibility is that an entire biosphere was deliberately engineered by the Virgonians and placed onto the planet, either specifically designed to develop into what is seen now, or simply to evolve by itself.
It is also possible that Abzu was a world in the galaxy-spanning Builder Empire before the Birch Planet's constructions, allowing life to evolve into its current state naturally. In this model, the Virgonians would have preserved the world for some unknown reason and moved it from it's former location in the Pristini Galaxy to become a satellite of the Birch Planet.
Colonisation of the R'yepelagic Zone Edit
The X-ray radiation in the R'yepelagic Zone initially meant that any dead bodies that floated down to the seafloor from higher zones was sterilized of any bacteria carried down inside it that might break it down. This lead to mountains of bodies of large creatures piling up over time. These bodies wouldn't decompose but were not perfectly preserved as they would bloat with seawater and there general fine cellular molecular structure would become disorganized. The period where these corpses existed en masse is called the Coufarizoic Era
Eventually the corpses piled so high that the tops of the resulting mountains extended far enough away from the seafloor that the X-ray radiation levels were tolerable to some of the bacteria that were carried down there. This lead to rapid natural selection for X-ray tolerance, resulting in many unrelated clades of so-called Chiophilic Bacteria arising. Natural selection continued with higher and higher tolerance being selected for as this allows for exploitation of deeper layers of organic waste as food. This period of organic decomposition following the Coufarizoic Era is called the Sapizoic Era, with the very start being called the Refrigictian Period.
Many small parasites within the corpses that fell into the R'yepelagic were also able to survive the low-dose radiation of the early Sapizoic, allowing them to also evolve to resist the radiation further down. This tolerance however, requires extremely rapid reproduction to work so that offspring can be produced before the genetic material of the parent becomes too damaged. This wasn't a problem for bacteria but forced creatures to become smaller and reproduce faster, often asexually to produce more offspring and survive the deeper depths. Bacteria and creatures from both the Vadum and Profundum Dynasties have floated down to the R'yepelagic and adapted, making this zone the only environment where they both coexist.
The decomposition of the Refrigictian Period lead to a decrease in the height of the thick layer of dead material that had accumulated in the Coufarizoic Era until eventually it was little more than an organic slime a few hundred meters deep in some locations and completely revealing the firmament in others. This meant the only habitat with any food to scavenge were in the part of the R'yepelgic with the highest degree of X-ray radiation. Beause of this, the evolutionary barrier that lead to no bacterial colonization occurring in the Coufarizoic was restored and no new organisms could drift down from above and colonize the seafloor. This period of a stagnant base-amount of organic detritus being present on the floor marked the end of the Refrigictian Period and the beginning of later eras in which the R'yepelgic organisms were able to evolve completely independently from the ecosystems they originated from with no gene-flow in between.
- Abzu was named by Master Bel, the first being from the First Gigaquadrant to discover it.
- The dial zones are named after the Latin words for twilight, true, bright, and blinding
- The pelagic zones are named after the Latin words for upper, middle, deep, abyss, hades, and void. The Harlopelagic Zone is named after Harland and Wolff, the company that built the Titanic. The R'lyepelagic Zone is named after R'lyeh, the dwelling place of Cthulhu.
- Archimoral is named after Archimedes, who discovered the principles of bouancy