Rediscovery of Hemigrammus unilineatus (Gill, 1858) (Characiformes, Characidae) in Ecuador after more than three decades

Hemigrammus unilineatus (Gill, 1858) (Characidae) is rediscovered in Yasuní National Park, eastern Ecuador, where it has not been reported since 1987. We present a detailed taxonomic description, including measurements and photographs, as well as a distribution map of this species in Ecuador. Based on our new evidence, we confirm the presence of H. unilineatus in the Ecuadorian Amazon.