Doyos was a male Trill who held the rank of captain in the Trill Defense Ministry in the 2370s. In early-October 2376, Captain Doyos was the commanding officer of a military presence defending the Caves of Mak'ala from neo-Purist rioters. When General Taulin Cyl and Ezri Dax arrived in the runabout USS Rio Grande, Doyos reported their status to the general. (DS9 - Worlds of Star Trek: Deep Space Nine novel: Trill: Unjoined)