Tylosurus pacificus (Steindachner, 1876) is confirmed to have full species rank based on: 1) sympatry with T. acus melanotus at Isla Gorgona and in Panamá; 2) level of morphological differentiation in numbers of vertebrae, dorsal and anal fin rays; and 3) level of mtDNAdifferentiation. The eastern Pacific agujon needlefish is found from the Gulf of California, Mexico, to Peru, including the Galápagos Islands.
Keywords: Belonidae, Tylosurus, needlefish, eastern tropical Pacific