Xar-Shaa

The Xar-Shaa are an aquatic sapient species of gestalt intelligences and a former fringe civilization of the Covenant. Based out in several dozen systems in the trailing side of the Covenant's holdings within the Orion Arm, the Xar-Shaa are one of the more developed cultures encountered by the Covenant, and one of the oldest known post-Array civilizations in the explored regions of the galaxy. Though they do not keep many records outside their biological collectives, there is evidence suggesting they have been spacefaring for at least 30,000 years.

Overview
The Xar-Shaa were classified by the Covenant as Enigmatics: a nebulous category for sapient species which diverge visibly and considerably from the overall baseline of cognition and body plan exhibited by the Covenant's ruling species, and require considerable efforts to interact with. The Xar-Shaa were never fully integrated to the Covenant as they were regarded as being of little to no utility to the hegemony. An aquatic species with very limited self-locomotion on land and alien means of communication, the Xar-Shaa are neither physically impressive nor easily interacted with. However, as a fundamentally peaceful, predictable and slowly expanding species, they were not seen as a threat, and could still be communicated with in some capacity. Additionally, the Xar-Shaa have a curious lack of interest in the Forerunners or their technology, and were known to have sold artifacts to the Ministry of Tranquility on a handful of occasions.

The Xar-Shaa rarely venture outside their home sphere of influence, encompassing their homeworld of Lysiau, several dozen colonies, as well as oceans on a handful of nearby Covenant worlds; they are able to coexist with those worlds' main occupants rather effortlessly as they barely intrude on the biomes inhabited by terrestrial species. As such they are largely a non-factor to the Covenant at large, their most notable interactions with the collective being with envoys and artifact retrieval teams.

The most notable peculiarity of the Xar-Shaa among all known interstellar civilizations is their species-wide refusal to use slipspace for interstellar travel or any other reason. This is due to the extreme psychological symptoms Xar-Shaa experience while in slipspace, comparable to a constant panic attack or psychosis which can leave them permanently scarred. While Covenant scholars have sought to study the reasons for this, no definite answer has been found. Because Xar-Shaa communication is notoriously cryptic and barely translates to most Congruent species' modes of thought and languages, they are also challenging to study. Most likely the phenomenon is due to some inherent psychological quirk, though the Xar-Shaa has been known to refer to something dubbed the Terror in their deep past being the origin. Whatever the cause, all native Xar-Shaa interstellar colonization efforts rely on relativistic travel and their interstellar colonies effectively lack communication with one another aside from periodic updates by peripatetic Xar-Shaa who permanently inhabit their massive ocean-ships that travel across the relatively dense Xar-Shaa sphere across the many decades it usually takes to move between systems. Since the Covenant contact, some Xar-Shaa colonies have hired Covenant-based couriers or signals guilds to take care of their communications.

Partly due to their unique evolution, the Xar-Shaa also perceive time in a particular manner. Rather than a linear, consistent passage of time, their perception of time is highly dependent on the density of events that occur; if very little of note happens over a century, for example, then that century can be equivalent to a decade or less. This mentality has lent itself well to the Xar-Shaa's slower-than-light colonization efforts, and it also makes the exact timeline of Xar-Shaa history difficult to trace.

Biology
The Xar-Shaa are characterized by their peculiar life cycles; over the course of their lifetimes, they transition from a motile to a sessile state, in which they proceed to spend most of their life. Their youth and mature stages are different from one another to the extent that the Covenant initially mistook them for two different species existing in a symbiotic relationship. The Xar-Shaa are hermaphrodites, and most closely resemble amoebas or bryozoa, their bodies comprising an irregularly-shaped "hub" from which numerous fine tendrils sprout. As they mature, these amorphous entities link together to form something akin to sapient coral reefs.

When it comes to developing complex technology, the Xar-Shaa had the odds stacked against them much more so than many other species including humans, due to the many limitations of their evolutionary environment. Xar-Shaa begin their lives in shallow waters, at which point they remain capable of venturing on land. At this stage, they are almost entirely under the direction of the more intelligent mature Xar-Shaa. In the early stage of their lives, Xar-Shaa individuals often form temporary meldings, or proto-gestalts, with other young Xar-Shaa to share experiences and information.

Their pseudo-amphibious nature was imposed on them by evolution, as Lysiau experiences strong tidal phenomena due to its massive moon. Lysiau's highly elliptical orbit takes the planet close to its parent stars, where it is showered by stellar radiation. To avoid radiation exposure, the maturing Xar-Shaa migrate to the deeper parts of their oceans, where they eventually enter the final and longest stage of their lives, known as the Melding stage. Over a period of centuries, they abandon most of their capacity for self-locomotion and root into the ocean floor as coral-like entities, melding with others of their kind as well as the symbiotic seafloor ecology, creating vast sessile gestalt networks that can endure for millennia. This is the intellectual, cognitive and cultural peak of the Xar-Shaa, with each coral ecology representing vast wisdom and a silent culture of contemplation wholly unknowable to outsiders. Over time, individual Xar-Shaa consciousnesses fade away and sublimate into the greater collective; this is sometimes viewed by outsiders as the "death" of a Xar-Shaa individual, though the Xar-Shaa themselves do not reportedly recognize the concept as such. The Xar-Shaa gestalts, which exist in a symbiosis with the rest of the ocean ecology, can encompass vast regions. Over time, their inner parts harden, calcify and become increasingly solipsistic, while the outer layers, composed of younger specimens, retain some mobility and more connection with the outside world. The development of advanced technology has allowed mature Xar-Shaa collectives to venture beyond ocean floors, though they require enormous and cumbersome pressure suits to do so. Coupled with the species' natural instincts for "rooting", the inconvenience involved with moving means that most Xar-Shaa prefer not to do so unless absolutely necessary. Even then, the gestalts involved tend to be on the younger end of the scale, being still in the process of Melding or having completed it only recently.

The Xar-Shaa's youth stage is naturally rather short due to their home planet's radiation cycles, though the development of technology as well as the offworld colonization of more hospitable worlds has allowed individuals to survive longer before maturing. Such individuals are also the Xar-Shaa's main means of interacting with other species. The mature Xar-Shaa rely almost entirely on their young to conduct business with the outside, as well as operate and create most technology; individuals in the early phases of Melding can still move away from the collective but only do so when necessary (e.g. mating and instructing their young, or when migrating to other worlds). There is a complex social hierarchy between the two stages, and they are so different from one another that the earlier perception of them as two separate species is not an entirely inaccurate analogy. The young Xar-Shaa are usually eager to join their older brethren in the depths, but most of their collectives require the young to first gather valuable experience in order to add something new to the whole. If a Xar-Shaa in the youth stage goes too long without Melding or doing anything with their life, they will be looked down upon by their civilization as a whole, and risk being rejected by most gestalts; associations of such individuals sometimes form smaller rogue gestalts, or simply wither away and die.

Outside of meldings, the Xar-Shaa mainly communicate through optic means; they are able to convey enormous amounts of information to one another through changes in tendril coloration. However, this is largely inscrutable to other species, many of which are not even physically capable of perceiving the finest variations in their coloration. As such, communication with the Xar-Shaa is slow and difficult for other species, even with technological assistance. Auditory communication and language do not come naturally to them, and so they take time to parse incoming information and formulate their own responses in an understandable form. During the Melding process, Xar-Shaa link their neural structures with another individual or a larger collective, enabling every constituent of that collective to effectively read one another's thoughts.