Trill symbiont

A Trill Symbiont, from the planet Trill (planet|Trill]], is a sentient vermiform lifeform, transferred from one Trill humanoid host to another upon the death of the previous host. Some other races can be used to host a Trill symbiont; however, living within a non-Trill host can physically damage both the symbiont and the non-Trill host over an extended period of time.   When transfered to the next host, the symbiont brings with it the memories of all previous hosts, which, upon joining, the new host will be able to access.

When not joined, symbionts usually live in pools within the Trill Caves of Mak'ala, cared for by the Guardians. Communication between symbionts occurs via electrical impulses transmitted through the pool's milky water.The Symbionts live in the Caves of Mak'ala on Trill and are cared for by the Guardians.

The Symbiosis Commission oversees joining between Trill humanoid hosts and Trill symbionts. According to widely-held beliefs, one in every thousand Trill humanoids can join with a symbiont. In actuality, this is closer to 50% of the Trill humanoid population: a closely-guarded secret as not to cause general concern amongst the population. Each year, approximately 5,000 Trill humanoids become initiates with only approximately 300 symbionts available for joining. 

Symbionts

 * Dax symbiont
 * Jonar symbiont

Rites and ceremonies

 * Rite of Emergence
 * Zhian'tara