Tholians are mostly made of a crystalline material. Their biology requires high temperatures around 480 Kelvin (207 °C, 404 °F) in order to keep their hard mineral carapaces sufficiently soft. Although they could tolerate lower temperatures for a brief period of time, Tholians are killed by sustained insufficient heat as their carapace would begin to freeze and crack below ca. 380 Kelvin.
Tholians are hermaphroditic, meaning they possess both male and female characteristics.
Because of their crystalline structure, Tholians are also naturally able to emit various forms of radiation, which - in addition to using it as a weapon - they could modulate in order to communicate over short distances.
There are also a number of biological features shared by the Tholians and the Crystalline Entity.
 Other Information
- See Tholian Assembly
 Duty officers
- Tholian at Memory Alpha, the Star Trek Wiki.
- Tholian at Memory Beta, the non-canon Star Trek Wiki.
- Season 6 Dev Blog #10 - Designing Tholian Visuals
- Official forum post by captjamjamz: Tholians - A look at their vessels (07/06/2012)
|Details||Tholian Assembly • Tholian • Tholia • Nukara Prime • Azure Nebula|
|Ground Forces||Tholian Ensign • Tholian Lieutenant • Tholian Commander • Tholian Captain|
|Starships||Tholian Widow • Tholian Mesh Weaver • Tholian Orb Weaver (Mob) • Tholian Recluse • Tholian Tarantula|
|NPCs||Inmate 91856 • Tholian Project Leader|
|NPC starships||Azar • Ikukube • Iskel • Ketus • Lelkene • Loskene • Naskeel • Presa Gran • Saphene • Seldspar • Tik'r • Zagristi • Zlo'Pauk|