A new species of the butterflyfish genus Prognathodes is described from specimens collected at a depth of 55–61 m off Pearl and Hermes Atoll, Northwestern Hawaiian Islands. This species has been observed by mixed-gas divers and from submersibles at depths ranging from 45–187 m throughout the Hawaiian Archipelago, with shallower sightings in the Northwestern Hawaiian Islands and deeper in the Main Hawaiian Islands. It is similar to P. guezei (Maugé and Bauchot 1976) from the western Indian Ocean, and at least one other undescribed species of Prognathodes from Palau, differing from these species in the number of soft dorsal-fin rays, size of head, and body depth. There are also differences in the life color, and a substantial genetic difference from the Palauan species (d » .08 in mtDNA cytochrome oxidase I).
USA - Hawaii