Xar-Shaa

The Xar-Shaa are an aquatic sapient species and a former tributary 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.

The Xar-Shaa were never fully integrated to the Covenant as they were regarded as being of little to no utility to the hegemony. As a high-pressure aquatic species with very limited self-locomotion and thought processes thrice as slow as the average of the major Covenant species, 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 be communicated with in some capacity, acting as informants for news from parts of the galaxy where even the Covenant feared to tread and vice versa. 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 as well as oceans on a number of nearby Covenant worlds, as they barely intrude on the biomes of the other Covenant species. Their native environments are deep ocean floors, they require cumbersome environment suits to operate in conditions the major species consider normal, and everything they do, whether it be movement, thought, or communication, they do much slower than any of the main Covenant species. As such they are largely a non-factor to most, and were largely interacted with by San'Shyuum envoys and artifact retrieval teams during the Covenant's existence.

Biology
The Xar-Shaa are characterized by their peculiar life cycles. They begin their lives in the upper layers of oceans and spend the first one-fourth of their lives as partly amphibious, albeit still maritime-based. At this stage, they are almost entirely under the direction of the more intelligent mature Xar-Shaa. As they enter the final and longest stage of their lives, known as the Melding stage, they sink deep into ocean floors and root there as coral-like entities, melding with others of their kind as well as the rest of the seafloor ecology, creating vast sessile networks of thinking coral. This is the intellectual, congnitive 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 coralline networks, which exist in a symbiosis with the rest of the ocean ecology, can encompass vast regions in deep oceans. 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 Xar-Shaa themselves most closely resemble amoebas or bryozoa, their bodies comprising an irregularly-shaped "hub" from which numerous fine tendrils sprout. The youth stage could be quite short due to their home planet's radiation cycles, though offworld colonization has allowed individuals to survive longer in the youth phase. Such individuals are mainly those expected to interact with other species; for the Xar-Shaa themselves are often eager to join their older brethren in the depths. 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 could technically still move away from the collective but rarely choose to do so. There is a complex social hierarchy between the two stages, and they are so different from one another it would almost be more useful to view them as two separate species.