Gargantuan starfish-like beings that have lived in the oceans of Europa since long before the ice melted and who are physiologically accustomed to the high pressures of the deep seafloor. They can range in size from a city block to a small country, but despite their massive size, they are not predators; rather, their slow, efficient metabolism and a mutualistic relationship with chemosynthetic bacteria open_in_new allows them to absorb nutrients ejected from the seafloor’s ubiquitous hydrothermal vents.
Their massive size and radial body structure caused multiple nerve bundles to enlarge into sub-brains, resulting in “collegial” mentalities that have multiple personalities within each organism open_in_new and the ability to reproduce asexually through mitosis, dividing their body into two genetically identical stars. Although there are many stars now inhabiting the seas, they all descended from a single genetic originator.
Functionally immortal and with multiple consciousnesses within each organism, behemoth stars are able to draw nuanced conclusions about the world and their place in it. In addition to being deeply philosophical thinkers, they have a remarkable understanding of the Jovian system, developed based on the minute gravitational impacts of each body on the movements of the sea. Rather than document this knowledge, they instead rely on genetic memory to transmit it across generations. Combined with their rudimentary technological advancements due to a lack of survival pressure, they could appear primitive to a human observer, though this is far from the truth.
Reproduction
A star with access to sufficient resources will continue developing split minds as it grows and eventually experience consensus failure. Consensus failure wouldn’t be like an argument over what to have for dinner; after all, the consensus excels at resolving these types of “arguments” because that is what it evolved to do. Consensus failure is more akin to a philosophical disagreement on the very nature of existence.
This ideological impasse triggers the star to tear itself apart, creating two partial stars that retain the same genetic information, memories, and knowledge of the parent, though these immediately begin to diverge at the moment of division. This is considered the most natural method of reproduction since it only occurs when stars are thriving and has a high likelihood of success. Nonetheless, division is both mentally and physically traumatic, and even successful divisions require a period of recovery during which both child stars are weakened and vulnerable.
An alternative form of division is external trauma. As a result of predation this only occurs in younger, smaller stars; older stars have essentially perfected the technique of being big enough that everything else in the ocean leaves them alone, with the exception of star-on-star violence. Division due to injury is more likely to fail, because it may result in an premature or uneven division with insufficient mature split-minds to manage the child stars during the recovery period.
Lastly, and hardly a true form of division, a star under stress may undergo abortive jettison. This approach “kills off” part of the star by dividing with prejudice against one or two of the most immature split-minds, who will not be able to thrive. This is typically seen when a sudden reduction in resource availability means that the local population can no longer be supported, or when a limb and/or its respective split mind is diseased or disordered in some way.
Interestingly, a population of stars undergoing abortive jettison due to a period of resource scarcity end up creating a source of food for other sea creatures in the cadavers of the jettisoned stars. In this way, they act as an important rebalancing force of the seafloor food web.
Notable Lines
Because stars maintain the genetic memory of their originating star, their history is well-known despite being unfathomably ancient. The below is a rough translation of such history.
The first star, Prime spent millions of years evolving in the seas of Europa, developing a split-mind neural architecture and a mutualistic relationship with chemosynthetic bacteria that allowed them to feed on hydrothermal vents. Eventually their split-minds reached consensus failure for the first time and they divided into Prime (Abundant) and Prime (Sovereign). Abundant and Sovereign avoided each other while recovering from the division, as they were the only creatures in the sea who could possibly harm or compete with the other. Each contained the complete genetic memories of Prime, but with no way to communicate they retreated into their internal split-mind consciousnesses.
Eventually Abundant also experienced consensus failure and divided into Prime Abundant (Bellicose) and Prime Abundant (Mutable). Bellicose and Mutable remained near each other during their recovery periods, and slowly developed the ability to chemically communicate by modifying their preexisting mutualism with chemosynthetic bacteria. Together, they continued to grow and mature.
With only three stars in the sea, Bellicose and Mutable still had access to plenty of resources, and their newfound communication abilities made the prospect of division less alienating. This lowered their consensus thresholds, and eventually they both divided, creating a generation of four Abundant descendants. The recovery period of this generation began to strain the energy resources of their ranging area, especially after two divided again into four.
At this time, Sovereign was a more perfect consensus and had not divided, and this line of six Abundant descendants began to attract their attention as they began to edge beyond their ranging area. Tensions came to a head when Sovereign attacked one of the Abundant line to access a particularly desirable cluster of vents and the Abundant line retributed. Though they took great losses, they were ultimately able to injure Sovereign enough to trigger division, creating a line of two Sovereign descendants.
The division between the two was unequal, forcing one into an extended period of recovery. In the meantime, following their shorter recovery period and wary of continuing to be outcompeted, the other again engaged the Abundant line. This kicked off a period of skirmishes where the two sides traded injuries and casualties, with outcomes increasingly falling in the Abundant line’s favor due to their greater numbers and ability to communicate. After a final sally where the Abundant line used the timing of recovery periods to their benefit, the only surviving member of the Sovereign line was forced to retreat. This silent monolith still wanders the sea, avoiding all other stars. They respond uniquely to consensus failure with abortive jettison, rather than true division, thereby maintaining “sovereignty” over their knowledge, memories, and name.
Meanwhile, descendants of both the Bellicose and Mutable line had survived the fighting, but division as a result of injuries sustained in combat meant their numbers were abnormally high and the resources required for recovery quickly outstripped those available from the seafloor vents. The more-aggressive Bellicose line, who had developed specialized combat knowledge from the previous skirmishes, forced the Mutable line off of the most productive vents.
After being displaced from the most productive vents, the Mutable line experienced heavy casualties and eventually divided into two sub-lines; Prime Abundant Mutable (Curator), who learned how to tend to less-productive hydrothermal vents to improve their output, becoming a line of Curators, and Prime Abundant Mutable (Pilgrim), who began dividing more quickly, creating smaller stars better able to tolerate the lower pressures of shallower depths and migrating up the slope of the seafloor where they had less competition.