The Large Mass Union Ship (大シュガフ船 Dai Shugafu-sen) is an enormous amalgamation of trillions of Gauna. Hundreds of kilometers wide, it is first detected when it is three light years away from Sidonia. It becomes a persistent threat in the series, and eventually meets up with Sidonia in the Lem system.
The Large Mass Union Ship has a structure similar to an earth jellyfish. Consisting of a large "hood" or "bell," the top of the Gauna extends to cover hundreds of kilometers in diameter. "Beneath" this bell lie hundreds of tentacles, some kilometers across, that can move independently. Within the Gauna itself are innumerable True Bodies, measured in the trillions.
Before the assault on the Large Mass Union Ship, Sidonia discovers that the ship has been growing, and that the number of True Bodies is increasing. This implies that the ship has a way to create or give birth to new Gauna.
First Appearance Edit
The Large Mass Union Ship is first detected when it is three light years from Sidonia. At the beginning of the story, it is the first positive Gauna contact in a hundred years. Whether this is the only Mass Union Ship of this scale or not is unknown.
Lem System Edit
The Large Mass Union Ship is first encountered in the Lem system, when it crashed into the moon outpost created by the first colonists of the Lem system. Located on Lem VII's moon, this outpost was the first attempt at colonization by Sidonia, The colonists were convinced that the lack of Guardians and and Kabizashi would cause the Gauna to ignore the outpost. This was, sadly, untrue, and the entire outpost was wiped out.
Reaction to Heigus Particles Edit
By the time of the rescue of Teruru Ichigaya, it is known that the Gauna react to Heigus Particles. Using this, a non-Heigus ship was able to pass by extremely close to the Large Mass Union Ship, allowing close-up observation without any reaction from the Gauna.