Jarlath's species was a humanoid species native to the Delta Quadrant that preferred desert-like environments. Culturally, they had a concept of a barter system and considered species that didn't to be unsophisticated.
At least nine years prior to 2373, a group including Jarlath, was abducted from their colony by the Nyrians, who incarcerated him in their biosphere vessel. In 2373, Jarlath made contact with the crew of the USS Voyager, who lived in the environment adjacent his that of his people's, thereafter, he cooperated in assisting in their mutual escape. (VOY: "Displaced")