The newly identified species, Pyrolycus jaco, is the first fish species to be described from the hydrothermal seep site known as Jaco Scar, located at a Pacific tectonic plate margin off Costa Rica. The small eel-like fish, measuring roughly 6 inches long with a light pink to lavender-colored body, has been observed nestling among tube worms at depths of 5,700 to 5,900 feet.