Planet of Origin: Daribo, a planet oribiting the star Vysu in Votanis star system in the Milky Way Galaxy, which they shared with another species, the Indogenes. Before being destroyed along with the other planets of the system some 5000 years ago, Daribo had three moons, 2 of which had irregular orbits.
Castithans are a humanoid species looking pretty much like pale skin humans with lighter colored eyes which are genetically compatible with the latter.
Arrogant by nature, they view themselves as the most important of any species and among themselves have developed a strict hierarchical caste system with minimal interactions between them. As it is a patriarchal society, females are also expected to be fairly submissive to the males. They have developed a severe monotheistic religion. After making contact with other species from their star system, they were one of the founding members of the Votanis Collective.
As of 5000 years ago, they had developed STL space travel and fled their homeworld when their system underwent a stellar cataclysm.
Source: Defiance TV series.