This species differs from its congeners in having the following set of characters: postorbital photophore (PO) small in males greater than 60 mm, 12.1- 20.0% upper jaw length (UJL) (vs. moderate to large, 21.0-46.6% UJL, in P. atrox, P. liemi, and P. lucingens; female PO small, 7.9-10.8% UJL (vs. moderate to large, 9.4-18.9% UJL, in all other species of Photostomias except P. guernei; accessory orbital (AO) small to moderate in males greater than 60 mm, 2.1-7.4% UJL (vs. small, 2.4-4.7% UJL, in P. lucingens); females maturing (ova > 0.2 mm) at approximately 70 mm (vs. 100 mm in P. atrox and P. liemi); three tooth patches at posterior end of the first, second, and third basibranchials (vs. 2 basibranchial tooth patches in P. guernei); total of dorsal- and anal-fin rays 48-52, rarely 53 (vs. 57-63, rarely 56, in P. goodyeari) (Ref. 80463).