This species is distinguished from other species in the subgenus Photonectes by the following set of characters: dorsal-fin rays 11-14, anal-fin rays 12-16; IV photophores 38-39, PV photophores 24-25; no blue luminous tissue; reduced length of gill filaments on first branchial arch, less than depth of gill arch; barbel with 2 large bulbs in series; two large bulbs in series and a tiny bulb at the end of the filament. Photonectes waitti differs from P. mirabilis and P. phyllopogon in having 11-14 dorsal-fin rays (vs. 16-17 and 20-23, respectively), 12-16 anal-fin rays (vs. 19-20 and 22-25, respectively), and 38-39 IV photophores (vs. 33-34 and 30-31, respectively); from P. coffea in having gill filaments on first gill arch reduced (vs. very long, extending beyond gill opening), PV photophores 24-25 (vs. 29-31); from P. achirus, P. caerulescens, and P. mirabilis in lacking blue luminous tissue (Ref. 92891).