Among recently sorted deep-pelagic (0–1500 m) collections made in the northern Gulf of Mexico (Gulf hereafter) during the National Oceanic and Atmospheric Administration (NOAA), Natural Resource Damage Assessment (NRDA), Offshore Nekton Sampling and Analysis Program (T. Sutton, Principal Investigator), were three female specimens of Lasiognathus that differ from all known material in having an internally pigmented anterior escal appendage and an elongate pair of distal filamentous prolongations. In addition to reporting the first record of the genus in the
Gulf, the new species is diagnosed and described, and a revised key to the species of the genus is provided.