Biology and appearance
Their species have the similiar evolutionary developments to creatures with bioluminescence like cephalopods and jellyfish. Meaning they are partly made out of water. Their cells developed a harder layer of skin around their bodies after leaving the waters. Seeing as they are unable to move around outside aquatic enviroments they were given bio-engineered enviromental suits. The spider-like legs would help them maintain balance and long arms to grab hold of objects. The Yu'Jal's elongated can reach the height of a human adult.
The Yu'Jal started out as ordinary creatures on their oceanic homeworld about 51,700 B.C' when they began to develope intelligence and sentient thought. An Aqua expedition ship came to the Lumaris system to study new alien lifeforms on Yin-Musho Heer where they encountered the Yu'Jal, despite their lack advance technology they reponded well to the exploer's communications. They soon became used to the outworlders and especially to the Aqua believing them to be a higher race as any other beings in the Aqua alliance. The Yu'jal began to explore and learn the regions of space, even learn how alien species evolved on alternate paths of evolution on their homeworlds. They gotton along well with races with similiar goals such as the Thihilem, the Sha'dahls and especially humans in the late 21st century. Like the THihilem they collect genetic samples for studies and may perhaps create new species.
Around 758 A.D. A Yu'Jal named T'Ruu Yer that went with the Republic cruiser had discovered a strange star-shaped vessel. It was unlike any they encounter. There were no life signs detected and learned all of the 'alien' crew were dead of unkown cause. They took the ship for further studies and later discovered most of the technology belonged some alien races that are native to the Milky Way. It was unkown what became their origin but the Sha'dahl Empire knew that they were an experiment and were thought to be wiped out for crimes an Anakadian had commited.
'The Zan Ghoul War'
A thousand years ahead when reports of a Zan Ghoul hive world was setting course to Aqua space they had to develop a weapon or some kind to slow the hive ships to build time. Their homeworld was later invaded and almost all hope was lost for their race until the Sha'dahl fleet arrived to aid them. During when the Zan Ghouls go into hibernation for later decades they quickly developed weapon systems and shields for the Galactic Republic on the next wave of invasion.
After joining the Alliance they believed that understanding of space became their calling, their technology evolved at an incredible rate to gather knowledge of the species' culture, biology, evolution and many things to know of the lifeforms, even to know of the planets and stars. Though they are cautious when meeting new civilizations and understanding them, should they encounter a race that has yet to leave their homeworld and a Level 1 civilization they sent out probes to the surface to gather data for the Aqua Alliance before making first contact with that native race.
Yu'Jal technology were designed to recognise DNA signatures only to Yu'Jal or some closes members of the alliance they are trusted with. Their enviromental suits are also capable of allowing them to communicate to their vessels, even without them. They are even well known for their powerful energy web technology to defend the fleet, also use capture and shut down or reboot all power to the enemey/inrtuding vessels except the life support systems