Brachyura

Brachyura was the name of a planet that was annexed to the T'au Empire during its First Sphere Expansion.

It is also the name of a xenos species of tiny, intelligent and dextrous-limbed crustaceans that inhabited that world.

Due to the growing shortage of T'au by the end of the First Sphere Expansion, the Water Caste sought to further integrate the Brachyura into the empire by assigning them to the delicate assembly of the minuscule Plasma Generators needed to fuel the latest Earth Caste inventions, a task which they proved unmatched at.