Memh was a Trill symbiont and one of the Annuated's caretakers. It was several thousand years old as of 2376.
Memh was in a female host serving as a private in the Trill military during the Kurlan genocide, and was one of those who participated in the destruction of Kurl. She was a weapons specialist aboard a Trill starship enforcing the medical quarantine at Kurl and was ordered to destroy four escaping Kurlan ships. Her commanding officer then ordered the release of biogenic weapons to which Memh complied. Following the events at this world and back in her own home, Memh's host took her own life by slitting her wrists. Memh never again took a host after this incident and remained at the bottom of the Caves of Mak'ala, tending to the Annuated.
When Ezri Dax was escorted back to the shallows of Mak'ala after her visit to the Annuated, Memh escorted the dying Cyl symbiont back to the Annuated and expressed its sympathy to Dax for her loss. (DS9 novel: Trill: Unjoined)