The Sheliak are a vaguely humanoid R3-type lifeform. The Sheliak are a reclusive people, avoiding contact with the Federation whenever possible. This may be due to the Sheliak attitude that humanoids are an inferior form of life. The Treaty of Armens was established in 2255 between the Sheliak and the Federation which ceded several worlds to the Sheliak. There was virtually no contact with the Sheliak for over a century thereafter, until they demanded that a Federation colony on Tau Cygna V be removed.
Sheliak colonists refer to themselves as "the Membership" and they have a governing body called Sheliak Corporate. Their homeworld is located in the Shelia system. Unlike most humanoids, the Sheliak prefer to exist in an environment that is the same temperature as their bodies.