Trill (species)
- Appearance: Mammalian; spots running across forehead, down sides to ankles
- Small subgroup lacks spots, has a prominent forehead ridge; formed as a result of cross-species migration of the Qu'vat virus, integrated rather than cured (TOS Novel: Forged in Fire; TNG: "The Host")
- Lifespan: ~100 years
- Homeworld: Trillius Prime
- Biological notes
- Evolved from furred primates with ridged brows (DS9 Novel: Trill: Unjoined)
- Biochemically compatible with symbionts also native to Trillius Prime
- Joining forms a composite being, with memories of each host and composite carried over into the next host
- Half of all Trill compatible with symbionts, but public belief is that the ratio is closer to one in a thousand, due to slim availability of symbionts to join (DS9: "Equilibrium")
- Only three hundred symbionts are available per year on average, as compared to one thousand applicants to the Symbiosis Commission
- Approved candidates usually in late-20s to early-30s, old enough to have formed a solid self-identity while still providing a significant portion of their life to share with a symbiont.
- Joining permanent 93 hours after implantation; at that point, symbiont cannot be removed without killing the host within hours (DS9: "Dax")
- Trill/symbiont connection facilitated by isoboramine neurotransmitter (DS9: "Equilibrium")
- Joined Trill especially sensitive to insect venom (DS9: "The Siege")
- Joining kept generally secret until public revelation in 2367 (TNG: "The Host")
- Reassociation between symbionts in a past relationship in new hosts is illegal under Trill law, to prevent the solidification of a permanent aristocracy via symbionts carrying forth organizations and connections from host to host
- Some Trill show psionic potential
- Such Trill often become Guardians in the Caves of Mak'ala to watch over unjoined symbionts
- Zhian'tara ritual allows a Guardian to transfer the memories of former hosts into individuals close to the current host, to better facilitate integration within the host
- Trill tend to have cold hands relative to body temperature (DS9: "A Man Alone"; DS9 Novel: Mission Gamma: Twilight)
- Cultural notes
- Trill games
- Customary for all Trill to submit applications to Symbiosis Commission at age twelve to evaluate suitability for joining (DS9 Short Story: "Second Star to the Right...")
- Not required, but few refrain (DS9 Short Story: "Second Star to the Right...")
- Musical instruments
- Syn lara (DS9 Novel: Mission Gamma: This Gray Spirit)
History
- c.23000 BCE: First joining between a symbiont and the species that would later become Trill (DS9 Novel: Trill: Unjoined)
- Early 21st century: First contact with Vulcans (DS9 Short Story: "First Steps")
- By 2154: First contact with Humans
- Tobin Dax present for launch of Columbia NX-02 (Destiny novel: Gods of Night)
- 2367: Status of Trill/symbiont relations becomes general public knowledge, as a result of injury incurred by Ambassador Odan during Peliar Zel mediations (TNG: "The Host")