| Vital statistics
|| Sixth Pass
|| Fort Hold
|| Campen, Pendora, Mostar, Doral, Theskin, Silma, Nerilka, Gallen, Jess, Peth, Amilla, Merin, Kista, Gabin, Mara, Nia and Lilla
| First appearance
|| Moreta: Dragonlady of Pern
Mercia was a daughter of Lord Holder Tolocamp of Fort Hold late in the Sixth Pass. Her twin sister was Merin.
She attended the Ruatha Hold gather with her parents and was caught in the quarantine when the illness hit Ruatha. She died of the illness.