Lieutenant Commander Tom Markel was a 23rd century Starfleet officer in command of the survey ship USS Ariel. In 2269, the crew of the Ariel was captured by the Lactrans on a survey mission. They were placed in a Lactran zoo until they were freed, about six weeks later, by the crew of USS Enterprise. (TAS: "The Eye of the Beholder")
Lieutenant Commander Markel mistakenly wore commander's stripes on his sleeves.